Publications by authors named "Wenxiang Chen"

64 Publications

Comparability of thyroid-stimulating hormone immunoassays using fresh frozen human sera and external quality assessment data.

PLoS One 2021 15;16(6):e0253324. Epub 2021 Jun 15.

Department of Clinical Laboratory, Beijing Chaoyang Hospital, Beijing Center for Clinical Laboratories, The Third Clinical Medical College of Capital Medical University, Beijing, P.R. China.

Background: This study aimed to assess the comparability among assays using freshly frozen human sera and external quality assessment (EQA) data in China.

Methods: Twenty-nine serum samples and two commercial EQA materials, obtained from the National Center for Clinical Laboratories (NCCL), were analyzed in triplicate using eight routine TSH assays. The commutability of commercial EQA materials (NCCL materials) was evaluated in accordance with the CLSI EP30-A and IFCC bias analysis. Median values obtained for the NCCL EQA materials were used to determine the systematic and commutability-related biases among immunoassays through back-calculation. The comparability of TSH measurements from a panel of clinical samples and NCCL EQA data was determined on the basis of Passing-Bablok regression. Furthermore, human serum pools were used to perform commutable EQA.

Results: NCCL EQA materials displayed commutability among three or five of seven assay combinations according CLSI or IFCC approach, respectively. The mean of systematic bias ranged from -13.78% to 9.85% for the eight routine TSH assays. After correcting for systematic bias, averaged commutability-related biases ranged between -42.26% and 12.19%. After correction for systematic and commutability -related biases, the slopes indicating interassay relatedness ranged from 0.801 to 1.299 using individual human sera, from 0.735 to 1.254 using NCCL EQA data, and from 0.729 to 1.115 using pooled human serum EQA(the commutable EQA).

Conclusions: The harmonization of TSH measurement is challenging; hence, systematic and commutability-related biases should be determined and corrected for accurate comparisons among assays when using human individual serum and the commercial EQA materials.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0253324PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8205121PMC
June 2021

Measurement of serum 17-hydroxyprogesterone using isotope dilution liquid chromatography-tandem mass spectrometry candidate reference method and evaluation of the performance for three routine methods.

Clin Chem Lab Med 2021 Feb 25;59(3):523-532. Epub 2020 Nov 25.

National Center for Clinical Laboratories, Beijing Engineering Research Center of Laboratory Medicine, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, P.R. China.

Objectives: Accurate measurements of serum 17-hydroxyprogesterone (17OHP) are essential for diagnosis and treatment monitoring for congenital adrenal hyperplasia patients. The performance of serum 17OHP routine methods remains highly variable that calls for a candidate reference measurement procedure (cRMP) to improve the standardization of serum 17OHP measurements.

Methods: Serum samples spiked with internal standards were extracted with a combination of solid-phase extraction and liquid-liquid extraction. The 17OHP was quantified by the isotope dilution coupled with liquid chromatography/tandem mass spectrometry (ID-LC/MS/MS) with electrospray ionization in positive ion mode. Nine structural analogs of 17OHP were evaluated for interferences. The precision and analytical recovery were assessed. Twenty native and 40 spiked serum for performance evaluation were measured by the cRMP and two clinical LC/MS routine methods.

Results: No apparent interferences were found with the 17OHP measurement. The within-run, between-run, and total precision for our method were 0.4-0.8%, 0.6-2.0%, and 1.0-2.1% for four pooled serum (2.46-102.72 nmol/L), respectively. The recoveries of added 17OHP were 100.0-100.2%. For the performance of two LC/MS routine methods, they showed relative deviation ranges of -22.1 to 1.1% and -6.7 to 12.8%, respectively.

Conclusions: We developed and validated a reliable serum 17OHP method using ID-LC/MS/MS. The desirable accuracy and precision of this method enable it to serve as a promising cRMP to improve the standardization for serum 17OHP routine measurements.
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http://dx.doi.org/10.1515/cclm-2020-0410DOI Listing
February 2021

Commutability of possible external quality assessment materials for progesterone measurement.

Clin Biochem 2021 Jan 12;87:39-45. Epub 2020 Nov 12.

National Center for Clinical Laboratories, Beijing Engineering Research Center of Laboratory Medicine, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, PR China; Chinese Academy of Medical Sciences and Peking Union Medical College, PR China. Electronic address:

Background: The commutability of control materials used for external quality assessment (EQA) programs is of great importance. Evaluating the commutability of control materials is crucial to assess their suitability for EQA programs.

Methods: Forty-eight individual patient serum samples, commercial EQA samples, human serum pools (HSPs), commercially available sterile filtered charcoal stripped serum (CS) and swine serum were analyzed using the isotope dilution liquid chromatography-tandem mass spectrometry (ID LC-MS/MS) comparative method and six immunoassays for progesterone. The commutability was assessed according to the EP14-A2 guideline and the difference in bias approach, respectively.

Results: According to the EP14-A2 guideline, HSPs and CS were commutable for all the tested immunoassays, while swine serum showed positive matrix effects in some assays. Based on the difference in bias approach, a large number of inconclusive and noncommutable results appeared.

Conclusions: The commutability of the processed materials varied depending on which evaluation approach and criterion was applied. Noncommutability of the EQA materials was observed. And HSPs and CS were possible commutable candidate control materials according to the EP14-A2 guideline.
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http://dx.doi.org/10.1016/j.clinbiochem.2020.10.012DOI Listing
January 2021

Commutability Assessment of Candidate External Quality Assessment Materials for Aminotransferase Activity Measurements Based on Different Approaches in China.

Ann Lab Med 2021 01 25;41(1):68-76. Epub 2020 Aug 25.

National Center for Clinical Laboratories, Beijing Hospital, National Center of Gerontology, Beijing Engineering Research Center of Laboratory Medicine, Beijing, P. R. China.

Background: Using commutable external quality assessment (EQA) materials is important for monitoring successful harmonization efforts. We assessed the commutability of four human serum pool (HSP) preparations to identify candidate EQA materials for alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity measurement.

Methods: One set each of 85 clinical samples (CSs) was collected for ALT and AST activity measurement. The 15 candidate EQA materials included four types of HSP preparations (A to D): materials A, C, and D contained human original recombinant (HOR) aminotransferases; materials B was mixed leftover samples. The CSs and 15 candidate EQA materials were analyzed using seven routine assays, and the ln-transformed results were analyzed in 21 assay pairs. Commutability was assessed using Deming regression, with a 95% prediction interval (CLSI approach) and the difference in bias with an error component model (International Federation of Clinical Chemistry and Laboratory Medicine [IFCC] approach).

Results: For ALT, all materials were commutable for 14-21 assay pairs according to the CLSI and IFCC approaches. For AST, B01-03 showed commutability for 14-21 assay pairs, and C01-03 and D01-03 showed commutability for no less than 10 assay pairs according to the two approaches. A01-06 were commutable for 9-16 assay pairs according to the CLSI approach, but for 6-9 assay pairs according to the IFCC approach.

Conclusions: Mixed leftover samples showed desirable commutability characteristics as candidate EQA materials for routine aminotransferase activity measurements. Human serum bases supplemented with HOR were commutable for most routine ALT activity measurements.
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http://dx.doi.org/10.3343/alm.2021.41.1.68DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7443529PMC
January 2021

Evaluation of serum electrolytes measurement through the 6-year trueness verification program in China.

Clin Chem Lab Med 2020 Jul 28;59(1):107-116. Epub 2020 Jul 28.

National Center for Clinical Laboratories, Beijing Engineering Research Center of Laboratory Medicine, Beijing Hospital, National, Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, P.R. China.

Objectives: The National Center for Clinical Laboratories (NCCL) in China initiated a serum electrolyte trueness verification (ETV) program in 2014 for measurement standardization.

Methods: Every year, two levels of fresh frozen commutable serum samples determined by inductively coupled plasma mass spectrometry (ICP-MS) reference methods were transported to participating clinical laboratories for the measurement of sodium, potassium, calcium and magnesium. Both samples were measured 15 times in 3 days, and the mean values and coefficient variations (CVs) were calculated from the results. The tolerance limits of trueness (bias), precision (CV) and accuracy (TE) based on the biological variation database were used as the evaluation criteria. The overall trend of the ETV program over 6 years was surveyed by calculating the pass rates of the participating laboratories. The mean bias, inter-laboratory CV, and TE of all laboratory results were analysed. Furthermore, homogeneous and heterogeneous systems were compared, and the bias and CV results of mainstream analysis systems were analysed.

Results: Pass rates of the three quality specifications increased, and the overall mean bias and inter-laboratory CVs decreased. The homogeneous system was superior to the heterogeneous system for calcium and magnesium measurements. For sodium, potassium, calcium and magnesium, the minimum bias corresponded to Hitachi, Siemens, Beckman AU and Roche, respectively. For inter-laboratory robust CVs, no obvious differences were observed between each peer group.

Conclusions: The commutable ETV materials assigned via reference methods can evaluate the accuracy and reproducibility of an individual laboratory and the calibration traceability and uniformity between laboratories for measurements.
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http://dx.doi.org/10.1515/cclm-2020-0355DOI Listing
July 2020

"Colloid-Atom Duality" in the Assembly Dynamics of Concave Gold Nanoarrows.

J Am Chem Soc 2020 07 24;142(27):11669-11673. Epub 2020 Jun 24.

Beijing National Laboratory for Molecular Sciences, College of Chemistry, Peking University, Beijing 100871, China.

We use liquid-phase transmission electron microscopy (TEM) to study self-assembly dynamics of charged gold nanoarrows (GNAs), which reveal an unexpected "colloid-atom duality". On one hand, they assemble following the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory for when van der Waals attraction overruns slightly screened electrostatic repulsion. Due to concaveness in shape, GNAs adopt zipper motifs with lateral offset in their assembly matching with our modeling of inter-GNA interaction, which form into unconventional structures resembling degenerate crystals. On the other hand, further screening of electrostatic repulsion leads to merging of clusters assembled from GNAs, reminiscent of the coalescence growth mode in crystals driven by minimization of surface energy, as we measure from the surface fluctuation of clusters. Liquid-phase TEM captures the initial formation of highly curved necks bridging the two clusters. Analysis of the real-time evolution of neck width illustrates the first-time observation of coalescence in colloidal assemblies facilitated by rapid surface diffusion of GNAs. We attribute the duality to the confluence of factors (e.g., nanoscale colloidal interaction, diffusional dynamics) that we access by liquid-phase TEM, taking turns to dominate at different conditions, which is potentially generic to the nanoscale. The atom aspect, in particular, can inspire utilization of atomic crystal synthesis strategies to encode structure and dynamics in nanoscale assembly.
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http://dx.doi.org/10.1021/jacs.0c04444DOI Listing
July 2020

Pedestrian estimation of their crossing time on multi-lane roads.

Accid Anal Prev 2020 Aug 7;143:105581. Epub 2020 Jun 7.

Shaanxi Key Laboratory of Behavior and Cognitive Neuroscience, School of Psychology, Shaanxi Normal University, China. Electronic address:

Estimation of one's own crossing time is an important process in making road-crossing decisions. This study evaluated the pedestrian's (esp. the elderly) ability to estimate crossing time in a field experiment. The estimated crossing time was measured by an interval production method (participants produced an interval to represent their estimated crossing time) and an imagined crossing method. The results showed that while young pedestrians generally had an accurate estimation of their crossing time, old pedestrians consistently underestimated the crossing time in both methods, especially at a wider road. What's worse, even fast walking cannot compensate for the large underestimation. Further analysis showed that although old pedestrians had the declined motor imagery ability and the worse general timing accuracy, none of them can account for the inaccuracy of estimation. These findings suggest that underestimation of crossing time may be one of the important reasons for the acknowledged risky road crossing decision-making in old pedestrians. It also calls for studies on assistive roadway designs and intervention programs targeting old pedestrians.
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http://dx.doi.org/10.1016/j.aap.2020.105581DOI Listing
August 2020

Efficiency and risks of selenite combined with different water conditions in reducing uptake of arsenic and cadmium in paddy rice.

Environ Pollut 2020 Jul 29;262:114283. Epub 2020 Feb 29.

Institute of Environmental Microbiology, College of Resources and Environment, Fujian Agriculture & Forestry University, Fuzhou 350002, China. Electronic address:

The co-contamination of arsenic (As) and cadmium (Cd) in soils is a common problem. Selenium (Se) can reduce the uptake of As and Cd in plants, and in practice, the alternate wetting and drying is a common culture mode in rice production. However, it is unknown whether Se can efficiently reduce As and Cd concentrations in crops suffering from a high-level contamination of As and Cd under different soil water conditions. In this study, we assessed the efficiency and risks of selenite [Se(IV)], in a pot experiment, to reduce the uptake of As and Cd in a rice plant (YangDao No 6) growing in a heavily contaminated soil by As and Cd (pH 7.28) under different soil water conditions. The results showed that Se(IV) failed to control the grain total As and Cd concentrations within their individual limited standard (0.2 mg kg) despite that Se(IV) significantly reduced the grain total As and Cd concentrations. The soil drying treatment alone could reduce the accumulation of arsenite [As(III)] in the grains, but additional Se(IV) stimulated the accumulation of As(III) in the grains under soil drying conditions. In addition, the addition of Se(IV) enhanced the As and Cd concentrations in the shoots and/or roots of rice plants under certain conditions. The above results all suggested that the utilization of Se(IV) in a high contaminated soil by As and Cd cannot well control the total concentrations of As and Cd in plants. In this study, the available concentrations of As and Cd in the rhizosphere soil, the rhizosphere soil pH, the formation of root iron/manganese plaques and the concentrations of essential elements in the grains were monitored, and the related mechanisms on the changes of these parameters were also discussed. This study will give a guideline for the safe production of rice plants in a heavily co-contaminated soil by As and Cd.
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http://dx.doi.org/10.1016/j.envpol.2020.114283DOI Listing
July 2020

TGFβ attenuates cartilage extracellular matrix degradation via enhancing FBXO6-mediated MMP14 ubiquitination.

Ann Rheum Dis 2020 08 14;79(8):1111-1120. Epub 2020 May 14.

Department of Orthopaedics, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China

Objectives: FBXO6, a component of the ubiquitin E3 ligases, has been shown to bind high mannose N-linked glycoproteins and act as ubiquitin ligase subunits. Most proteins in the secretory pathway, such as matrix metalloproteinases, are modified with N-glycans and play important roles in the development of osteoarthritis (OA). However, whether FBXO6 exerts regulatory effects on the pathogenesis of OA remains undefined.

Methods: The expression of FBXO6 was examined in the cartilage of human and multiple mouse OA models. The role of FBXO6 in cartilage degeneration was analysed with mice, transgenic mice. The FBXO6 interacting partner MMP14 and its regulatory transcriptional factor SMAD2/3 were identified and validated in different pathological models as well as mice.

Results: The expression of FBXO6 decreased in the cartilage from human OA samples, anterior cruciate ligament transaction (ACLT) -induced OA samples, spontaneous OA STR/ort samples and aged mice samples. Global knockout or conditional knockout of FBXO6 in cartilage promoted experimental OA process. The molecular mechanism study revealed that FBXO6 decreased MMP14 by ubiquitination and degradation, leading to inhibited proteolytic activation of MMP13. Interestingly, FBXO6 expression is regulated by transforming growth factor β (TGFβ)-SMAD2/3 signalling pathway. Therefore, the overexpression of FBXO6 protected mice from post-injury OA development.

Conclusions: TGFβ-SMAD2/3 signalling pathway suppressed MMP13 activation by upregulating of FBXO6 transcription and consequently promoting MMP14 proteasomal degradation. Inducement of FBXO6 expression in OA cartilage might provide a promising OA therapeutic strategy.
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http://dx.doi.org/10.1136/annrheumdis-2019-216911DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7392491PMC
August 2020

FTIR-assisted MALDI-TOF MS for the identification and typing of bacteria.

Anal Chim Acta 2020 May 18;1111:75-82. Epub 2020 Mar 18.

Zhejiang Provincial Key Laboratory of Advanced Mass Spectrometry and Molecular Analysis, Institute of Mass Spectrometry, School of Material Science and Chemical Engineering, Ningbo University, Ningbo, Zhejiang, 315211, China; Department of Chemistry, Fudan University, Shanghai, 200433, China. Electronic address:

MALDI-TOF MS is well-recognized for microbial identification and widely used in research and clinical fields due to its specificity, speed of analysis, and low cost of consumables. However, the classification or identification accuracy is poor for E. coli and Shigella. In addition, FTIR is a promising tool for bacterial typing. In this study, 14 strains of E. coli and 9 strains of Shigella were typed by both MALDI-TOF MS and FTIR techniques. Alternatively, a data fusion strategy using these two approaches was attempted to achieve better typing accuracy. Hierarchical clustering analysis (HCA) revealed that the typing accuracies for selected E. coli and Shigella from blood agar were 65.2%, 78.3%, and 100% for MALDI-TOF MS, FTIR, and FTIR combined with MALDI-TOF MS, respectively. Based on these results, a library constructed of the MS-IR fusion data was employed to identify individual bacteria at the strain level, and the library-based typing accuracies for 207 test spectra of sample strains from three different culture media yielded 97.6% accuracy for distinguishing between E. coli and Shigella at genus level. For species level and strain level, it yielded 95.2% and 92.3% typing accuracy, respectively. These results indicate that FTIR is a better technique for typing selected E. coli and Shigella than MALDI-TOF MS, and the accuracy is increased by combining the data from MALDI-TOF MS and FTIR spectroscopy. FTIR could be used to supplement MALDI-TOF MS for the identification and typing of taxonomic microorganisms.
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http://dx.doi.org/10.1016/j.aca.2020.03.037DOI Listing
May 2020

Toxicity of different forms of antimony to rice plants: Effects on reactive oxidative species production, antioxidative systems, and uptake of essential elements.

Environ Pollut 2020 Aug 12;263(Pt B):114544. Epub 2020 Apr 12.

Institute of Environmental Microbiology, College of Resources and Environment, Fujian Agriculture & Forestry University, FuZhou, 350002, China. Electronic address:

Antimonite [Sb(III)] and antimonate [Sb(V)] are known to have different toxicity to plants, but the corresponding mechanisms are not fully understood. This study was conducted to investigate reactive oxygen species (ROS), antioxidant systems, and levels of certain essential elements in response to exposure to Sb(III) and Sb(V). Results showed that exposure to Sb(V) caused oxidative stress in a rice plant (Yangdao No.6). Sb(III) was shown to be more toxic than Sb(V) as judged from a lower shoot biomass, a higher loss of essential elements, and higher production of superoxide anion free radicals (O). The toxicity of Sb(III) might partially be due to the disturbance of the O dismutation reaction, which resulted in root cell membrane damage under exposure to 20 mg L Sb(III). Sb(V) stimulated the shoot fresh weight and the shoot uptake of many essential elements. Moreover, Sb(V) and Sb(III) both stimulated the accumulation of calcium in the shoots and roots, and calcium was found to significantly correlate with the concentrations of many essential elements and with some parameters correlated to antioxidant systems, suggesting a Ca-induced regulatory mechanism. The activity of glutathione peroxidase was significantly enhanced by Sb(V) and Sb(III), suggesting a role in scavenging hydrogen peroxide. Catalase was activated by exposure to 20 mg L Sb(III) in the roots and by exposure to 20 mg L Sb(V) both in the shoots and roots. However, peroxidase was activated by exposure to 5 mg L Sb(III) in the shoots and by exposure to 5 mg L Sb(V) in the roots. This study, for the first time, showed the differences between Sb(V) and Sb(III) toxicity when looking at the antioxidant response and essential element uptake.
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http://dx.doi.org/10.1016/j.envpol.2020.114544DOI Listing
August 2020

Toxicity of different forms of antimony to rice plant: Effects on root exudates, cell wall components, endogenous hormones and antioxidant system.

Sci Total Environ 2020 Apr 20;711:134589. Epub 2019 Nov 20.

Institute of Environmental Microbiology, College of Resources and Environment, Fujian Agriculture & Forestry University, Fuzhou 350002, China.

Antimony (Sb) is a toxic element for both human and plants, but the toxic responses of plants to different forms of antimony and the associated mechanisms are unknown. This study was carried out to investigate the effects of different forms of Sb [Sb(III) and Sb(V)] on the root exudates, root endogenous hormones, root cell wall components and antioxidant systems in rice plant via three hydroponic experiments. The results showed that Sb(III) displayed a higher toxicity than Sb(V) to the plant which accumulated much more Sb in its tissues under Sb(III) exposure than that under Sb(V) exposure. Under Sb(III) exposure, most of absorbed Sb was found to be Sb(III) in the shoots and roots; however when plants were exposed to Sb(V), most of absorbed Sb in this rice plant was Sb(V). Only two kinds of endogenous hormones were detected as abscisic acid (ABA) and salicylic acid (SA). The addition of Sb(III) significantly increased the content of ABA but Sb(V) did not, probably suggesting the higher toxicity of Sb(III) than Sb(V) might be due to the stimulation of ABA content. The addition of Sb(III) significantly increased the concentration of oxalic acid but decreased the concentrations of formic, acetic and maleic acids. Sb(V) also enhanced the oxalic acid concentration at 20 mg L Sb(V) treatment level but reduced the concentrations of formic and acetic acids. Different forms of Sb dose-dependently increased the content of pectin, but significantly enhanced the content of lignin in cell wall. Different forms of Sb induced oxidative stress, but rice plant triggered the activities of superoxide dismutase (SOD) and ascorbate peroxidase (APX) to counteract the oxidative stress.
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http://dx.doi.org/10.1016/j.scitotenv.2019.134589DOI Listing
April 2020

Development and validation of a candidate reference method for serum cortisol by isotope dilution liquid chromatography-tandem mass spectrometry combined with dextran sulfate-Mg precipitation.

Anal Bioanal Chem 2020 Feb 10;412(6):1325-1333. Epub 2020 Jan 10.

National Center for Clinical Laboratories, Beijing Hospital, National Center of Gerontology, Beijing, P.R. China, No.1 DaHua Road, Dong Dan, Beijing, 100730, China.

Accurate and precise cortisol measurements are requisite for ensuring appropriate diagnosis and management of diseases related with adrenal or pituitary gland disorders. Prompted by the needs in characterization of certified reference materials and quality assurance for serum cortisol measurements, we developed and evaluated a highly reliable measurement procedure based on isotope dilution liquid chromatography-tandem mass spectrometry (ID LC-MS/MS) combined with dextran sulfate-Mg precipitation as the sample pretreatment. An appropriate amount of serum was accurately weighed and spiked with the isotope labelled internal standard. After precipitation, massive lipids and lipoproteins were removed from serum matrix. The clear supernatant was transferred and extracted with ethyl acetate-hexane solution. The cortisol was analyzed with LC-MS/MS in positive electrospray ionization mode. The within-run and total coefficient of variations (CVs) ranged from 0.3 to 0.6% and 0.7 to 1.2%, respectively, for a concentration range of 76.30 to 768.04 nmol/L. A regression comparison of the results obtained by the present method and the certified values of ERM-DA451 showed agreement with no statistical difference (Y = 1.0092 X-0.7455; 95% CI for the slope, 0.9940 to 1.0212; 95% CI for the intercept, - 3.6575 to 2.6390, r = 0.999). All structural analogs of cortisol tested were well resolved from cortisol in 12 min on a phenyl ligand column under an isocratic elution. The limit of quantification was estimated to 5 pg cortisol in absolute amount. This method is accurate and simple and can be served as a candidate reference measurement procedure in establishment of serum cortisol reference system.
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http://dx.doi.org/10.1007/s00216-019-02356-2DOI Listing
February 2020

The emerging role of IMD 0354 on bone homeostasis by suppressing osteoclastogenesis and bone resorption, but without affecting bone formation.

Cell Death Dis 2019 09 10;10(9):654. Epub 2019 Sep 10.

Department of Orthopaedics, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China.

Osteoporosis is caused by an imbalance between bone formation and bone resorption. Receptor activator of nuclear factor-κB ligand (RANKL) promotes the activity and differentiation of osteoclasts via activating the nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways. IMD 0354 is a selective molecular inhibitor of inhibitor of NF-κB kinase subunit beta (IKKβ) and effective for treatment of acute and subacute inflammatory diseases through the suppression of NF-κB activation. However, the effect of IMD 0354 on bone homeostasis is unknown. In this study, we demonstrated that IMD 0354 significantly attenuated ovariectomy-induced bone loss and inhibited osteoclastogenesis in mice, whereas bone formation was not affected. Additionally, IMD 0354 dramatically inhibited osteoclast differentiation and function induced by RANKL and macrophage colony-stimulating factor in bone marrow monocytes as verified by tartrate-resistant acid phosphatase (TRAP) staining as well as bone resorption assay in vitro. Subsequently, we found that activation of NF-κB signaling and the ERK/c-Fos axis were blunted during osteoclast formation induced by RANKL. Transcription factors nuclear factor of activated T cells c1 (NFATc1) and c-Fos were suppressed with the decreased expression of osteoclast-related genes by IMD 0354. Our findings suggest that IMD 0354 could be a potential preventive and therapeutic drug for osteoporosis.
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http://dx.doi.org/10.1038/s41419-019-1914-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6737093PMC
September 2019

Lycorine Induces Apoptosis and G1 Phase Arrest Through ROS/p38 MAPK Signaling Pathway in Human Osteosarcoma Cells In Vitro and In Vivo.

Spine (Phila Pa 1976) 2020 Feb;45(3):E126-E139

Department of Orthopaedics, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.

Study Design: Xenograft osteosarcoma mouse model.

Objective: We determined the effect of lycorine on osteosarcoma.

Summary Of Background Data: Osteosarcoma is an aggressive malignant neoplasm, is most prevalent in teenagers and adults and current treatment approaches have reached a survival plateau and attempts to improve osteosarcoma prognosis have proven unsuccessful. Thus there is clear evidence that development of new agents with high efficacy and fewer side effects to provide better prognostic outcome is urgently needed.

Methods: The toxicity, function and mechanism of lycorine (LY) on osteosarcoma were accessed in vitro by CCK-8 assay, flow cytometry, and western blotting and in vivo by the xenograft osteosarcoma mouse model.

Results: In this study, we found that LY exhibited dose-dependent and time-dependent cytotoxic effects on human osteosarcoma cell-lines SJSA-1 and U2OS, inducing G1 phase cell cycle arrest and cellular death via apoptosis. Mechanistically, LY treatment elevated ROS generation that activates the p38 mitogen-activated protein kinases (MAPKs) and p53-dependent apoptotic program. Inhibition of ROS generation by NAC or p38 MAPK signaling by SB203580 attenuated the p53-mediated cell cycle arrest and apoptosis induced by LY. In vivo administration of LY markedly reduced tumor growth with little organ-related toxicity in a mouse xenograft model of osteosarcoma.

Conclusion: Collectively, our data suggests that LY exhibit therapeutic potential for the treatment of osteosarcoma.

Level Of Evidence: N/A.
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http://dx.doi.org/10.1097/BRS.0000000000003217DOI Listing
February 2020

Commutability of external quality assessment materials for serum magnesium and calcium measurements.

Scand J Clin Lab Invest 2019 Oct 4;79(6):404-411. Epub 2019 Jul 4.

National Center for Clinical Laboratories and Beijing Engineering Research Center of Laboratory Medicine, Beijing Hospital, National Center of Gerontology , Beijing , China.

The commutability of pooled patient sera (PPS) and control materials (CM) should be evaluated to investigate their suitability for use in an external quality assessment (EQA) program. Individual human samples, PPS and CM were analyzed by four routine methods and inductively coupled plasma mass spectrometry reference methods for magnesium and calcium measurements. The commutability was analyzed according to EP14-A3 protocol and the difference in bias approach, respectively. For magnesium measurements, all PPS were commutable and 3/5 CM were commutable for all measurement systems according to the EP14-A3 protocol. For calcium measurements, most PPS were commutable for all measurement systems, but the CM were only commutable with the Cobas c702 system. The IFCC approach produced similar commutability profiles, except that a large number of inconclusive results appeared. The routine methods exhibited excellent linearity and precision. The majority of relative biases between the routine and reference methods were beyond the bias limits. The commutability of the CM and PPS vary depending on which evaluation approach and criterion is applied. Superiority in the commutability of PPS over CM was observed whichever evaluation approach is applied.
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http://dx.doi.org/10.1080/00365513.2019.1636404DOI Listing
October 2019

Effects of Particle Size on Mg Ion Intercalation into λ-MnO Cathode Materials.

Nano Lett 2019 Jul 28;19(7):4712-4720. Epub 2019 Jun 28.

Shell International Exploration and Production Inc. , Houston , Texas 77082 , United States.

An emergent theme in mono- and multivalent ion batteries is to utilize nanoparticles (NPs) as electrode materials based on the phenomenological observations that their short ion diffusion length and large electrode-electrolyte interface can lead to improved ion insertion kinetics compared to their bulk counterparts. However, the understanding of how the NP size fundamentally relates to their electrochemical behaviors (e.g., charge storage mechanism, phase transition associated with ion insertion) is still primitive. Here, we employ spinel λ-MnO particles as a model cathode material, which have effective Mg ion intercalation but with their size effect poorly understood to investigate their operating mechanism via a suite of electrochemical and structural characterizations. We prepare two differently sized samples, the small nanoscopic λ-MnO particles (81 ± 25 nm) and big micron-sized ones (814 ± 207 nm) via postsynthesis size-selection. Analysis of the charge storage mechanisms shows that the stored charge from Mg ion intercalation dominates in both systems and is ∼10 times higher in small particles than that in the big ones. From both X-ray diffraction and atomic-resolution scanning transmission electron microscopy imaging, we reveal a fundamental difference in phase transition of the differently sized particles during Mg ion intercalation: the small NPs undergo a solid-solution-like phase transition which minimizes lattice mismatch and energy penalty for accommodating new phases, whereas the big particles follow conventional multiphase transformation. We show that this pathway difference is related to the improved electrochemical performance (e.g., rate capability, cycling performance) of small particles over the big ones which provides important insights in encoding within the particle dimension, that is, the single-phase transition pathway in high-performance electrode materials for multivalent ion batteries.
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http://dx.doi.org/10.1021/acs.nanolett.9b01780DOI Listing
July 2019

Designing Strong Optical Absorbers Continuous Tuning of Interparticle Interaction in Colloidal Gold Nanocrystal Assemblies.

ACS Nano 2019 Jul 31;13(7):7493-7501. Epub 2019 May 31.

Department of Chemical and Biological Engineering , Drexel University , Philadelphia , Pennsylvania 19104 , United States.

We program the optical properties of colloidal Au nanocrystal (NC) assemblies an unconventional ligand hybridization (LH) strategy to precisely engineer interparticle interactions and design materials with optical properties difficult or impossible to achieve in bulk form. Long-chain hydrocarbon ligands used in NC synthesis are partially exchanged, from 0% to 100%, with compact thiocyanate ligands by controlling the reaction time for exchange. The resulting NC assemblies show transmittance, reflectance, optical permittivity, and direct-current (DC) resistivity that continuously traverse a dielectric-metal transition, providing analog tuning of their physical properties, unlike the digital control realized by complete exchange with ligands of varying length. Exploiting this LH strategy, we create Au NC assemblies that are strong, ultrathin film optical absorbers, as seen by a 6× increase in the extinction of infrared light compared to that in bulk Au thin films and by a temperature rise of 20 °C upon illumination with 808 nm light. Our LH strategy may be applied to the design of materials constructed from NCs of different size, shape, and composition for specific applications.
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http://dx.doi.org/10.1021/acsnano.9b02818DOI Listing
July 2019

Commutability assessment of reference materials for the enumeration of lymphocyte subsets.

Clin Chem Lab Med 2019 04;57(5):697-706

National Center for Clinical Laboratories, Beijing Hospital, National Center of Gerontology and Graduate School of Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, P.R. China.

Background Flow cytometric enumeration of lymphocyte subsets in peripheral blood can provide important information about immune status. Commutable reference materials (RM) are crucial for maintaining accurate and comparable measurement results over time and space. Commutability assessment of RMs for lymphocyte subsets enumeration has not been reported elsewhere. Methods Lymphocyte subsets were measured in triplicate on 56 patient samples and eight RMs using two measuring systems commonly used in laboratories (FACS Canto II and Cytomics FC500). The first step was to determine the suitability of RMs and comparability of different systems with patient samples. After the requirements of suitability and comparability were met, the second step was to assess commutability following regression approach and difference in bias approach. Results Two RMs were not measurable on FC500 system for CD3-CD16/56+ and CD3-CD19+ percentages. The results of comparability showed no significant difference in the two systems. Eight RMs for CD3+CD4+ cell count, six RMs for CD3+ and CD3+CD8+ percentages, five RMs for CD3-CD16/56+ percentage, and three RMs for CD3-CD19+ percentage were commutable using the two approaches. For CD3+, CD3+CD8+ and CD3-CD19+ percentages, the results of regression approach showed that one RM was non-commutable for each parameter, while the other approach showed that the RM was commutable. Conclusions The suitability of RM and comparability of different measuring systems are prerequisites for assessing commutability. This study indicated that different approaches led to different results. The difference in bias approach is recommended for criteria relating to medical requirements and performance characteristics of measuring systems in use.
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http://dx.doi.org/10.1515/cclm-2018-0915DOI Listing
April 2019

Measurement of serum progesterone by isotope dilution liquid chromatography tandem mass spectrometry: a candidate reference method and its application to evaluating immunoassays.

Anal Bioanal Chem 2019 Apr 26;411(11):2363-2371. Epub 2019 Feb 26.

Graduate School of Peking Union Medical College and Chinese Academy of Medical Sciences, 9 Dongdan Santiao, Beijing, 100730, China.

Measurement of serum progesterone is important in determining ovarian function. Most progesterone measurements are performed with immunoassays and results are often variable. Standardization of the measurements requires a reliable reference method. An isotope dilution liquid chromatography tandem mass spectrometry (ID-LC/MS/MS) method for the measurement of serum progesterone was developed. Serum samples were spiked with C-progesterone, extracted with a three-step liquid-liquid extraction, and analyzed by LC/MS/MS. A bracketing calibration was used for the analysis and samples were prepared gravimetrically. The developed method showed intra-run and total relative standard deviations (RSDs) of 0.50~0.58% and 0.71~1.33%, respectively. The analytical recoveries were 99.08~101.50%. Measurement results on certified reference materials obtained with this method agreed with the certified values within the stated measurement uncertainties. The method was applied to evaluate immunoassays through split-sample comparisons. A panel of 48 fresh frozen individual samples were measured with the ID-LC/MS/MS method, and six immunoassays and results were compared. Significant calibration biases and sample-specific deviations were observed on some of the immunoassays.
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http://dx.doi.org/10.1007/s00216-019-01676-7DOI Listing
April 2019

Standardization of measurement procedures for serum uric acid: 8-year experience from Category 1 EQA program results in China.

Clin Chem Lab Med 2019 03;57(4):476-482

National Center for Clinical Laboratories, Beijing Hospital, National Center of Gerontology, Beijing Engineering Research Center of Laboratory Medicine, No 1, Dahua Road, Dongcheng District, Beijing, P.R. China.

Background Serum uric acid is a critical clinical indicator, and results without equivalence among laboratories cause troubles for disease diagnosis and patient management. External quality assessment (EQA) is a common tool for enhancing harmonization/standardization, therefore, the National Center for Clinical Laboratories in China has initiated a category 1 EQA for serum uric acid measurement since 2010 for evaluating its process of standardization. Methods Commutable EQA samples with target values assigned by reference measurement procedures were sent to participant laboratories. Both concentrations were measured 15 times in 3 days then means and intra-laboratory coefficient of variations (CVs) were reported. Biological variation criteria were used for analysis with CLIA88 criteria as a comparison. Results A total of 1250 laboratories participated in EQA programs from 2010 to 2017, pass rates calculated according to desirable specifications in biological variation database were on a rise overall and inter-laboratory mean bias and CVs were on a decrease. Homogeneous systems showed better inter-laboratory CVs and pass rates than heterogeneous systems. For the mostly used measurement systems; Abbott, Beckman, Roche Modular, Siemens and Hitachi showed desirable performances other than Roche Cobas, according to biological variation criteria. Conclusions Our study provides reliable information on the standardization of measurement procedures for serum uric acid for manufacturers and laboratories. Further improvements for standardization are still needed to make laboratories more patient-centered.
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http://dx.doi.org/10.1515/cclm-2018-0274DOI Listing
March 2019

Unraveling the Morphology-Function Relationships of Polyamide Membranes Using Quantitative Electron Tomography.

ACS Appl Mater Interfaces 2019 Feb 14;11(8):8517-8526. Epub 2019 Feb 14.

BP Corporate Research Center , Naperville , Illinois 60563 , United States.

An understanding of how complex nanoscale morphologies emerge from synthesis would offer powerful strategies to construct soft materials with designed structures and functions. However, these kinds of morphologies have proven difficult to characterize, and therefore manipulate, because they are three-dimensional (3D), nanoscopic, and often highly irregular. Here, we studied polyamide (PA) membranes used in wastewater reclamation as a prime example of this challenge. Using electron tomography and quantitative morphometry, we reconstructed the nanoscale morphology of 3D crumples and voids in PA membranes for the first time. Various parameters governing film transport properties, such as surface-to-volume ratio and mass-per-area, were measured directly from the reconstructed membrane structure. In addition, we extracted information inaccessible by other means. For example, 3D reconstruction shows that membrane nanostructures are formed from PA layers 15-20 nm thick folding into 3D crumples which envelope up to 30% void by volume. Mapping local curvature and thickness in 3D quantitatively groups these crumples into three classes, "domes", "dimples", and "clusters", each being a distinct type of microenvironment. Elemental mapping of metal ion adsorption across the film demonstrates that these previously missed parameters are relevant to membrane performance. This imaging-morphometry platform can be applicable to other nanoscale soft materials and potentially suggests engineering strategies based directly on synthesis-morphology-function relationships.
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http://dx.doi.org/10.1021/acsami.8b20826DOI Listing
February 2019

Association of serum glycine levels with metabolic syndrome in an elderly Chinese population.

Nutr Metab (Lond) 2018 17;15:89. Epub 2018 Dec 17.

1Peking University Fifth School of Clinical Medicine, The MOH Key Laboratory of Geriatrics, Beijing Hospital, National Center of Gerontology, Beijing, 100730 People's Republic of China.

Background: Several studies have identified a negative association between serum glycine (Gly) levels and metabolic syndrome (MetS). However, this association has not been fully established in the elderly.

Methods: A total of 472 Chinese individuals (272 males and 200 females, 70.1 ± 6.6 years old) participated in a population-based, cross-sectional survey in Beijing Hospital. The MetS and its components were defined based on the 2006 International Diabetes Federation (IDF) standard for Asians. Serum Gly concentration was determined using isotope dilution liquid chromatography tandem mass spectrometry.

Result: The proportion of patients with MetS decreased gradually with increasing Gly levels ( for trend < 0.001), and serum Gly concentrations declined gradually with increasing numbers of MetS components ( = 0.03 for trend). After adjusting for age and gender, lower Gly levels were significantly associated with MetS and central obesity, with OR (95% CI) of 0.40 (0.25-0.65) and 0.46 (0.28-0.74). The stratified analysis conducted according to age showed that the OR between serum Gly levels and MetS was greater in those older than 65 (OR = 0.66; 95% CI, 0.51-0.86) than in those younger than 65 (OR = 0.89; 95% CI, 0.54-1.46). In the stratified analysis, using other age cut-off points, the results consistently showed that the association between serum Gly levels and MetS was more remarkable in the older groups.

Conclusions: Gly levels are associated with cardiometabolic characteristics and MetS in the elderly, and the association is more pronounced in very old people than in younger old people.
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http://dx.doi.org/10.1186/s12986-018-0325-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6297971PMC
December 2018

Knockdown of linc00152 inhibits the progression of gastric cancer by regulating microRNA-193b-3p/ETS1 axis.

Cancer Biol Ther 2019 7;20(4):461-473. Epub 2018 Nov 7.

d Department of Clinical Laboratory , Beijing University of Chinese Medicine Third Affiliated Hospital , Beijing , China.

Background: Gastric cancer (GC) is a serious threat for public health worldwide. Long non-coding RNA (lncRNA) linc00152 has been well reported to be an oncogene and a potential biomarker in multiple cancers including GC. However, the molecular mechanisms of linc00152 in GC development need to be further investigated.

Methods: RT-qPCR assay was employed to detect the levels of linc00152, microRNA-193b-3p (miR-193b-3p) and ETS1 mRNA. ETS1 protein level was measured by western blot assay. Cell proliferative, migratory and invasive capacities were assessed by colony formation together with CCK-8 assays, transwell migration and invasion assays, respectively. Bioinformatics analyses and luciferase reporter assay were used to explore whether miR-193b-3p could interact with linc00152 or ETS1 3'UTR. The roles and molecular basis of linc00152 silence on the growth of GC xenograft tumors were tested in vivo.

Results: Linc00152 expression was notably upregulated in GC tissues and cells. The proliferative, migratory and invasive abilities of GC cells were weakened by linc00152 depletion, miR-193b-3p overexpression or ETS1 knockdown. Linc00152 upregulation inhibited miR-193b-3p expression by direct interaction and abolished miR-193b-3p-mediated anti-proliferation, anti-migration and anti-invasion effects in GC cells. ETS1 was a target of miR-193b-3p and linc00152 could promote ETS1 expression by downregulating miR-193b-3p. In vivo experiments further validated that linc00152 knockdown inhibited the growth of GC xenograft tumors by upregulating miR-193b-3p and downregulating ETS1.

Conclusion: Knockdown of linc00152 inhibited GC progression by sequestering miR-193b-3p from ETS1 in vitro and in vivo, elucidating a novel molecular mechanism of linc00152 in promoting GC carcinogenesis.
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http://dx.doi.org/10.1080/15384047.2018.1529124DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6422511PMC
July 2020

Nanoimprinted Chiral Plasmonic Substrates with Three-Dimensional Nanostructures.

Nano Lett 2018 11 3;18(11):7389-7394. Epub 2018 Oct 3.

Center for Functional Nanomaterials , Brookhaven National Laboratory , Upton , New York 11973 , United States.

We report a large-area fabrication method to prepare chiral substrates patterned with arrays of multilayer, three-dimensional nanostructures using a combination of nanoimprint lithography and glancing angle deposition. Several structures are successfully fabricated using this method, including L-shaped, twisted arc and trilayer twisted Au nanorod structures, demonstrating its generality. As one typical example, arrays of L-shaped nanostructures, consisting of two layers of orthogonally oriented Au nanorods separated by a Ge dielectric layer in the thickness direction, exhibit giant optical chirality in the infrared region with an experimentally achieved g-factor as high as 0.38. Electromagnetic simulations show that the optical chirality results from plasmon hybridization between the two orthogonal Au segments. To demonstrate scalability, a 1 cm chiral substrate is fabricated with uniform chiral optical property. This method combines both high throughput and precise geometrical control and is therefore promising for applications of chiral metamaterials.
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http://dx.doi.org/10.1021/acs.nanolett.8b03785DOI Listing
November 2018

Ultrasensitive, Mechanically Responsive Optical Metasurfaces via Strain Amplification.

ACS Nano 2018 Nov 26;12(11):10683-10692. Epub 2018 Sep 26.

Optical metasurfaces promise ultrathin, lightweight, miniaturized optical components with outstanding capabilities to manipulate the amplitude, phase, and polarization of light compared to conventional, bulk optics. The emergence of reconfigurable metasurfaces further integrates dynamic tunability with optical functionalities. Here, we report a structurally reconfigurable, optical metasurface constructed by integrating a plasmonic lattice array in the gap between a pair of symmetric microrods that serve to locally amplify the strain created on an elastomeric substrate by an external mechanical stimulus. The strain on the metasurface is amplified by a factor of 1.5-15.9 relative to the external strain by tailoring the microrod geometry. For the highest strain amplification geometry, the mechano-sensitivity of the optical responses of the plasmonic lattice array is a factor of 10 greater than that of state-of-the-art stretchable plasmonic resonator arrays. The spatial arrangement and therefore the optical response of the plasmonic lattice array are reversible, showing little hysteresis.
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http://dx.doi.org/10.1021/acsnano.8b04889DOI Listing
November 2018

Association of serum metabolites with impaired fasting glucose/diabetes and traditional risk factors for metabolic disease in Chinese adults.

Clin Chim Acta 2018 Dec 17;487:60-65. Epub 2018 Sep 17.

The MOH Key Laboratory of Geriatrics, Beijing Hospital, National Center of Gerontology, Beijing 100730, China. Electronic address:

Background: Hyperglycemia has become a major health problem worldwide. We investigated the associations of serum metabolite levels with hyperglycemia (impaired fasting glucose/diabetes) and traditional risk factors for metabolic disease.

Methods: A total of 563 Chinese adults were categorized into hyperglycemia and control groups. Associations of serum metabolites, including branched-chain amino acids (BCAAs), aromatic amino acids (AAAs), glutamine (Gln), glutamic acid (Glu), Gln/Glu ratio, 25-hydroxyvitamin D, and lysophosphatidylcholine (LPC), with hyperglycemia and traditional risk factors of metabolic disease were investigated using our targeted metabolomics method.

Results: Participants with impaired fasting glucose or diabetes exhibited markedly lower levels of Gln/Glu and unsaturated LPC and higher levels of Glu and BCAAs. Gln/Glu ratio, unsaturated LPC, and 25-hydroxyvitamin D were positively correlated with protective factors, while saturated LPC, BCAAs, AAAs, and Glu revealed close correlations with traditional risk factors. In the logistic regression, low Gln/Glu ratio and high BCAA level were independent risk factors for hyperglycemia; the odds ratios (95% confidence interval) of the highest quartile compared with the lowest quartile were 0.499 (0.274-0.910) and 2.588 (1.313-5.102) (P < 0.05), respectively.

Conclusions: Gln/Glu ratio, BCAAs, and LPC were significantly related to hyperglycemia development and risk factors for metabolic disease.
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http://dx.doi.org/10.1016/j.cca.2018.09.028DOI Listing
December 2018

Evaluation of serum alkaline phosphatase measurement through the 4-year trueness verification program in China.

Clin Chem Lab Med 2018 11;56(12):2072-2078

National Center for Clinical Laboratories, Beijing Hospital, National Center of Gerontology, No. 1 Dahua Road, Dongcheng District, Beijing 100730, P.R. China.

Background Alkaline phosphatase (ALP) is critical for various diseases. The International Federation of Clinical Chemistry and Laboratory Medicine had recommended the new reference procedure in 2011, but many manufacturers did not trace results to the higher procedure. Since 2012, the National Center for Clinical Laboratories (NCCL) in China has organized the trueness verification program (TV) with commutable materials. The present study summarizes the 4-year TV program to give an overview of the measurement standardization for ALP results. Methods Commutable serum-based materials with different concentrations were prepared and sent to participating laboratories. The target values were assigned by the reference lab network. Results The analytical performance was evaluated according to three indexes: trueness (bias), imprecision (CV) and accuracy (total error [TE]). The number of participating laboratories increased from 115 in 2012 to 287 in 2016. The pass rates of precision for homogeneous and heterogeneous systems were all above 85% over the 4 years; however, the pass rates of bias were much lower (<50%). Among the homogeneous systems, Roche Cobas/Modular had an obvious negative bias, whereas the mean positive bias for Beckman AU was prominent. As to the heterogeneous systems, the pass rates of bias for Sichuan Maccura (57.1%-78.6%) were higher than Roche Cobas/Modular (4.4%-33.9%) and Beckman AU (35.7%-64.8%). Conclusions The PT/EQA program with commutable materials can be used to assess the trueness against target values assigned by reference procedures. For ALP, homogeneous systems did not perform better than heterogeneous systems. The bias for ALP performance was notable and was the main obstacle to its standardization in China.
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http://dx.doi.org/10.1515/cclm-2018-0399DOI Listing
November 2018

Commutability of external quality assessment materials for serum sodium and potassium measurements.

Clin Chem Lab Med 2019 03;57(4):465-475

Researcher, Beijing Hospital, National Center of Gerontology, National Center for Clinical Laboratories and Beijing Engineering Research Center of Laboratory Medicine, 1 Dahua Road, Dongdan, Beijing 100730, P.R. China.

Background The commutability of electrolyte trueness verification materials (ETVs) and commercial general chemistry materials (GCs) was evaluated to investigate their suitability for use in an external quality assessment (EQA) program for serum sodium and potassium measurements. Methods Eighty fresh individual human samples (40 for sodium measurements and 40 for potassium measurements), six ETVs and three GCs were analyzed by five routine methods (validated methods) and by inductively coupled plasma mass spectrometry reference methods (comparative methods) for the determination of sodium and potassium. The commutability was analyzed according to Clinical and Laboratory Standards Institute (CLSI) EP14-A3 protocol and difference in bias approach, respectively. The linearity, bias and imprecision of the routine methods were also assessed according to CLSI guidelines. Results According to EP14-A3 protocol, ETVs were commutable for all assays, and GCs were commutable for 3/5 assays for sodium. ETVs were commutable in most assays except Cobas C501, while GCs showed no commutability except in case of AU5821 for potassium. According to a difference in bias approach, the commutability of ETVs was inconclusive for most routine assays for both sodium and potassium, and GCs were inconclusive for sodium and non-commutable for potassium in most routine assays. The routine methods exhibited excellent linearities and precisions. The majority and minority of relative biases between the routine and reference methods were beyond the bias limits for sodium and potassium, respectively. Conclusions Superiority in the commutability of ETVs over GCs was observed among the sodium and potassium assays whichever evaluation approach was applied.
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http://dx.doi.org/10.1515/cclm-2018-0385DOI Listing
March 2019

3D Nanofabrication via Chemo-Mechanical Transformation of Nanocrystal/Bulk Heterostructures.

Adv Mater 2018 May 15;30(22):e1800233. Epub 2018 Apr 15.

Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA, 19104, USA.

Planar nanocrystal/bulk heterostructures are transformed into 3D architectures by taking advantage of the different chemical and mechanical properties of nanocrystal and bulk thin films. Nanocrystal/bulk heterostructures are fabricated via bottom-up assembly and top-down fabrication. The nanocrystals are capped by long ligands introduced in their synthesis, and therefore their surfaces are chemically addressable, and their assemblies are mechanically "soft," in contrast to the bulk films. Chemical modification of the nanocrystal surface, exchanging the long ligands for more compact chemistries, triggers large volume shrinkage of the nanocrystal layer and drives bending of the nanocrystal/bulk heterostructures. Exploiting the differential chemo-mechanical properties of nanocrystal and bulk materials, the scalable fabrication of designed 3D, cell-sized nanocrystal/bulk superstructures is demonstrated, which possess unique functions derived from nanocrystal building blocks.
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http://dx.doi.org/10.1002/adma.201800233DOI Listing
May 2018
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