Publications by authors named "Huiying Xu"

120 Publications

The effects of glucose-free and glucose-containing dialysate during dialysis in MHD patients: a prospective cross-over study.

Perfusion 2021 Sep 19:2676591211042726. Epub 2021 Sep 19.

Department of Nephrology, Beijing Tsinghua Changgung Hospital, Medical Center, Tsinghua University, Changping District, Beijing, China.

Objective: To investigate the effects of glucose-free and glucose-containing dialysates during dialysis in maintenance hemodialysis (MHD) patients by the prospective cross-over study, and detect glucose control methods in MHD patients.

Methods: A total of 66 MHD 18-75 years old patients in our hospital from Nov. 2019 to Mar. 2020 were recruited. All patients underwent HD with 4 hours per time, three times per week. Glucose-free dialysate (glucose-free group) and then 5.55 mmol/L glucose-containing dialysate (glucose-5.55 group) were used alternately in dialysis. The demographics and parameters of pre- and post-dialysis were recorded.

Results: A total of 60 patients were analyzed, and 28 patients among them had type 2 diabetes. Serum glucose pre and post dialysis were 8.64 ± 4.18 mmol/L versus 5.74 ± 1.82 mmol/L (p < 0.01) in glucose-free dialysate, and 9.31 ± 4.89 mmol/L versus 7.80 ± 2.59 mmol/L (p < 0.01) in glucose-5.55 dialysate. The post-dialysis blood glucose of glucose-free group was lower than glucose-5.55 group (5.74 ± 1.82 vs 7.80 ± 2.59, p < 0.01). About 18 (30.00%) patients in glucose-free group and 1 patient (1.67%) in glucose-5.55 group whose blood glucose was lower than 4.44 mmol/L (p < 0.01). About 29 patients (48.33%) in glucose-free group and 17 patients (28.33%; p = 0.02) in glucose-5.55 group have hunger feeling. Serum sodium level in the glucose-free group was higher than that in Glucose-5.55 group (137.92 ± 1.64 vs 136.70 ± 1.64, p < 0.01). Post-dialysis blood glucose had no significant differences between patients not using diabetes-related medication (13 patients) and patients using diabetes-related medication (15 patients) in glucose-free group (7.13 ± 1.78 mmol/L vs 6.08 ± 2.84 mmol/L, p = 0.23) and glucose-5.55 group (9.22 ± 2.59 mmol/L vs 9.35 ± 2.88 mmol/L, p = 0.90).

Conclusions: Glucose-free and glucose-5.55 dialysate both decrease the blood glucose post-dialysis. Dialysates containing 5.55 mmol/L glucose can reduce the incidence of hypoglycemia and lower serum sodium, but have no effect on blood pressure during dialysis. Stopping insulin and oral anti-diabetic drugs once before dialysis may not affect the control of blood glucose.
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http://dx.doi.org/10.1177/02676591211042726DOI Listing
September 2021

An artificial enzyme cascade amplification strategy for highly sensitive and specific detection of breast cancer-derived exosomes.

Analyst 2021 Sep 13;146(18):5542-5549. Epub 2021 Sep 13.

Lab of Biosystem and Microanalysis, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China.

Tumor-related exosomes, which are heterogeneous membrane-enclosed nanovesicles shed from cancer cells, have been widely recognized as potential noninvasive biomarkers for early cancer diagnosis. Herein, an artificial enzyme cascade amplification strategy based on a switchable DNA tetrahedral (SDT) scaffold was proposed for quantification of breast cancer-derived exosomes. The SDT scaffold is composed of G-quadruplex mimicking DNAzyme sequences on its two single-stranded edges and glucose oxidase (GOx) on the four termini of the complementary strands. In the initial state, the SDT scaffold is blocked by the switch strand which consists of partial complementary domains with the DNA tetrahedron and a MUC1 aptamer. MCF-7 exosomes could release the quadruplex-forming sequences through the recognition of the MUC1 aptamer. The newly formed DNAzyme brings GOx into spatial proximity and induces high-efficiency enzyme cascade catalytic reactions on the SDT. Consequently, high sensitivity toward MCF-7 exosome analysis was obtained with a wide linear range of 3.8 × 10 to 1.2 × 10 particles per mL and a limit of detection of 1.51 × 10 particles per mL. In addition, such a DNAzyme reconfiguration strategy was able to distinguish MCF-7 exosomes from other breast cancer cell derived exosomes, indicating its excellent method specificity. The proposed enzyme cascade strategy not only provides a novel signal transformation and amplification nanoplatform for quantifying the specific populations of exosomes, but also can be further expanded to the analysis of multiple cancer biomarkers.
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http://dx.doi.org/10.1039/d1an01071aDOI Listing
September 2021

High Frequency of Allergic Bronchopulmonary Aspergillosis in Bronchiectasis-COPD Overlap.

Chest 2021 Aug 5. Epub 2021 Aug 5.

Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Republic of Singapore. Electronic address:

Background: Allergic bronchopulmonary aspergillosis (ABPA) is associated with frequent exacerbations and poor outcomes in chronic respiratory disease, but remains underdiagnosed. The role of fungal sensitization in bronchiectasis-COPD overlap (BCO) is unknown.

Research Question: What is the occurrence and clinical relevance of Aspergillus sensitization and ABPA in BCO when compared with individuals with COPD or bronchiectasis without overlap?

Study Design: Prospective, observational, cross-sectional study.

Methods: We prospectively recruited 280 patients during periods of clinical stability with bronchiectasis (n = 183), COPD (n = 50), and BCO (n = 47) from six hospitals across three countries (Singapore, Malaysia, and Scotland). We assessed sensitization responses (as specific IgE) to a panel of recombinant Aspergillus fumigatus allergens and the occurrence of ABPA in relationship to clinical outcomes.

Results: Individuals with BCO show an increased frequency and clinical severity of ABPA compared with those with COPD and bronchiectasis without overlap. BCO-associated ABPA is associated with more severe disease, higher exacerbation rates, and lower lung function when compared with ABPA occurring in the absence of overlap. BCO with a severe bronchiectasis severity index (BSI; > 9) is associated significantly with the occurrence of ABPA that is unrelated to underlying COPD severity.

Conclusions: BCO demonstrates a high frequency of ABPA that is associated with a severe BSI (> 9) and poor clinical outcomes. Clinicians should maintain a high index of suspicion for the potential development of ABPA in patients with BCO with high BSI.
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http://dx.doi.org/10.1016/j.chest.2021.07.2165DOI Listing
August 2021

Time Perspective and Bedtime Procrastination: The Role of the Chronotype-Time Perspective Relationship.

Nat Sci Sleep 2021 24;13:1307-1318. Epub 2021 Jul 24.

Research Center of Brain and Cognitive Neuroscience, Liaoning Normal University, Dalian, Liaoning Province, People's Republic of China.

Introduction: Bedtime procrastination (BP) has a close relationship with one's chronotype, from a biological perspective on time. However, it remains unknown whether there is an association between BP and psychological time. Therefore, the aim of the present study was to evaluate the relationship between time perspective (TP) and BP and the effect of TP on the relationship between BP and chronotype by examining a sample of college students pre- and post-COVID-19 outbreak.

Methods: A total of 628 Chinese students (267 in pre-outbreak and 361 in post-outbreak) validly completed the Chinese version of the Bedtime Procrastination Scale, the Zimbardo Time Perspective Inventory (ZTPI), and the Morningness-Eveningness Questionnaire.

Results: Students with more BP behaviors exhibited greater deviation from a balanced TP, especially after the COVID-19 outbreak. Hierarchical regression analyses revealed that the past-negative and future orientations, as operationalized by the ZTPI, contributed independently to BP behaviors. The structural equation modeling analyses further demonstrated that morningness was significantly related to a more future-oriented TP, which in turn decreased BP in pre- and post-COVID-19 outbreak samples, while morningness was associated with a less past-negative-oriented TP, which in turn decreased BP only in the post-COVID-19 outbreak sample.

Conclusion: This study indicated that TP in students with BP predominantly focused on future orientation and that TP can mediate the relationship between chronotype and BP behaviors. However, the COVID-19 pandemic may disrupt the time flow and change the role of chronotype-TP in BP. These findings explain how individual differences in TP are associated with BP, which may be helpful in designing effective interventions to avoid BP, from the viewpoint of time perspective therapy.
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http://dx.doi.org/10.2147/NSS.S313157DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8318727PMC
July 2021

Coordination of plant hydraulic and photosynthetic traits: confronting optimality theory with field measurements.

New Phytol 2021 Jul 29. Epub 2021 Jul 29.

Department of Biological Sciences, Macquarie University, North Ryde, NSW, 2109, Australia.

Close coupling between water loss and carbon dioxide uptake requires coordination of plant hydraulics and photosynthesis. However, there is still limited information on the quantitative relationships between hydraulic and photosynthetic traits. We propose a basis for these relationships based on optimality theory, and test its predictions by analysis of measurements on 107 species from 11 sites, distributed along a nearly 3000-m elevation gradient. Hydraulic and leaf economic traits were less plastic, and more closely associated with phylogeny, than photosynthetic traits. The two sets of traits were linked by the sapwood to leaf area ratio (Huber value, v ). The observed coordination between v and sapwood hydraulic conductivity (K ) and photosynthetic capacity (V ) conformed to the proposed quantitative theory. Substantial hydraulic diversity was related to the trade-off between K and v . Leaf drought tolerance (inferred from turgor loss point, -Ψ ) increased with wood density, but the trade-off between hydraulic efficiency (K ) and -Ψ was weak. Plant trait effects on v were dominated by variation in K , while effects of environment were dominated by variation in temperature. This research unifies hydraulics, photosynthesis and the leaf economics spectrum in a common theoretical framework, and suggests a route towards the integration of photosynthesis and hydraulics in land-surface models.
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http://dx.doi.org/10.1111/nph.17656DOI Listing
July 2021

Mechanistic Insights into the Dual Directing Group-Mediated C-H Functionalization/Annulation a Hydroxyl Group-Assisted M-M-M Pathway.

ACS Omega 2021 Jul 1;6(27):17642-17650. Epub 2021 Jul 1.

Guangzhou Municipal and Guangdong Provincial Key Laboratory of Protein Modification and Degradation & Molecular Target and Clinical Pharmacology, State Key Laboratory of Respiratory Disease, School of Pharmaceutical Sciences, Guangzhou Medical University, Guangzhou 511436, China.

The experimental investigations on the catalyst [Cp*Rh(OAc) and Cp*Ir (OAc))]-controlled [3 + 2] and [4 + 2] annulations of oximes with propargyl alcohols have been finished in our previous work and a supposed dual directing group-mediated reaction pathway has been deduced for the chemodivergent product synthesis. However, the detailed interaction modes of the dual directing groups binding with the corresponding metal center to achieve the above observed chemoselectivity remain unclear and even contradict. For instance, the calculational traditional dual direct coupling transition states suggested that both Cp*Rh(OAc)- and Cp*Ir(OAc)-catalyzed reactions would generate five-membered indenamines as the dominant products [3 + 2] annulation. To address this concern, herein, systematic DFT calculations combined with proof-of-concept experiments have been carried out. Accordingly, a novel and more favorable M-M-M reaction mechanism, which involves an unprecedented HOAc together with a hydroxyl group-assisted reaction pathway in which the hydroxyl group acts as double effectors for the formation of M-O coordination and [MeO···H···O(CCH)O···H···O] bonding interactions, was deduced. Taken together, the present results would provide a rational basis for future development of the dual directing group-mediated C-H activation reactions.
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http://dx.doi.org/10.1021/acsomega.1c02183DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8280669PMC
July 2021

High-efficiency broadband tunable green laser operation of direct diode-pumped holmium-doped fiber.

Opt Express 2021 May;29(10):15564-15575

Green laser sources have become increasingly important for the application in scientific research and industry. Although several laser approaches have been investigated, the development of green lasers with the necessary efficiency and spectral characteristics required for practical deployment continues to attract immense interest. In this study, the efficient green laser operation of a Ho-doped fluoride fiber directly pumped by a commercial blue laser diode (LD) is experimentally investigated at various active fiber lengths. In the free-running laser, the slope efficiency was optimized up to 59.3% with 543.9 nm lasing, with respect to the launched pump power, using a 20-cm long active fiber. This is the maximum slope efficiency reported to date for a green fiber laser. A maximum output power of 376 mW at 543.5 nm was achieved by using a 17-cm long active fiber pumped at a maximum available launched pump power of 996 mW. Moreover, broadband tuning operation was demonstrated by employing a range of active fiber lengths, together with an intracavity bandpass filter. The operating wavelength was tunable from 536.3 nm to 549.3 nm. A maximum tuning power achieved was 118 mW at 543.4 nm for a 17-cm long active fiber. Moderate Ho-doped fiber length is shown to be effective in producing a high performance of a green fiber laser. The short-length of the active fiber considerably extends the green short wavelength operation due to limited reabsorption of the signal below 540 nm.
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http://dx.doi.org/10.1364/OE.426482DOI Listing
May 2021

Conventional vs high-sensitive troponins in acute exacerbations of chronic obstructive pulmonary disease.

Heart Lung 2021 May-Jun;50(3):430-436. Epub 2021 Feb 21.

Department of Cardiology, Tan Tock Seng Hospital, Singapore, 11 Jln Tan Tock Seng, Singapore 308433, Singapore.

Background: Cardiac troponins (cTn), either conventional or high-sensitive (hscTn) assays, are often performed during acute exacerbations of chronic obstructive pulmonary disease (AECOPD).

Objectives: To compare factors affecting abnormal conventional cTn and hscTn.

Methods: We retrospectively studied data from AECOPD patients with conventional or hscTn performed at presentation. Binary logistic regression was used to identify predictors for abnormal conventional cTn (>0.5 ug/L) and hscTn (>40 ng/L).

Results: There were 466 patients in the conventional cTn and 313 patients in the hscTn groups. Ischaemic electrocardiographic change was the only significant predictor for abnormal conventional cTn (OR 6.662 [CI 1.233-35.990], p = 0.028) while B-type natriuretic peptide levels (Adj OR 1.004 [CI 1.000-1.006], p = 0.010) and SpO/FiO ratio (Adj OR 0.115 [CI 0.017-0.069], p = 0.026) were significant predictors of abnormal hscTn.

Conclusions: Predictors of abnormal cTn differ between assays and should be taken into consideration when interpreting cTn during AECOPD.
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http://dx.doi.org/10.1016/j.hrtlng.2021.02.002DOI Listing
April 2021

A Novel Peptide-Equipped Exosomes Platform for Delivery of Antisense Oligonucleotides.

ACS Appl Mater Interfaces 2021 Mar 23;13(9):10760-10767. Epub 2021 Feb 23.

Lab of Biosystem and Microanalysis, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China.

Exosomes are natural delivery vehicles because of their original feature such as low immunogenicity, excellent biocompatibility, and migration capability. Engineering exosomes with appropriate ligands are effective approaches to improve the low cellular uptake efficiency of exosomes. However, current strategies face considerable challenges due to the tedious and labor-intensive operational process. Here, we designed a novel peptides-equipped exosomes platform which can be assembled under convenient and mild reaction condition. Cell-penetrating peptides (CPPs) was conjugated on HepG2 cells-derived exosomes surface which can not only enhance the penetrating capacity of exosomes but also assist exosomes in loading antisense oligonucleotides (ASOs). The cellular uptake mechanism was investigated and we compared the difference between natural exosomes and modified exosomes. The resulting nanosystem demonstrated a preferential tropism for cells that are parented to their source tumor cells and could remarkably increase the cellular delivery of G3139 with efficient downregulation of antiapoptotic Bcl-2. This work developed a rapid strategy for intracellular delivery of nucleic acids, thus providing more possibilities toward personalized cancer medicine.
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http://dx.doi.org/10.1021/acsami.1c00016DOI Listing
March 2021

Novel Dyes Design Based on First Principles and the Prediction of Energy Conversion Efficiencies of Dye-Sensitized Solar Cells.

ACS Omega 2021 Jan 28;6(1):715-722. Epub 2020 Dec 28.

State Key Laboratory of Heavy Oil Processing, Beijing Key Laboratory of Optical Detection Technology for Oil and Gas and College of Science, China University of Petroleum, Beijing 102249, P. R. China.

With the depletion of fossil energy, solar energy has gradually attracted people's attention. Dye-sensitized solar cells have developed rapidly in recent years due to their low cost and high conversion efficiency. In this article, based on the theoretical research on the photovoltaic parameters of DSSCs in the early stages of the research team, we have made an accurate prediction of , , and PCE of C286. (The error in our predicted PCE values was 3.33% relative to the experiment.) Also, we further designed a series of new dyes CH1-CH5 by introducing donors and co-acceptors with C286-C288 as the prototype using the DFT/TDDFT method. The PCE of the designed dyes CH2-CH5 exceed the given dye C286, especially the CH3 and CH4 obtained the PCE of 26.2 and 14.5%. This indicates the proposed dyes offer a dramatic improvement on PCE for DSSC devices. Moreover, the designed dyes such as CH3 and CH4 have great potential to be applied to photovoltaic applications, further enabling the design of novel, highly efficient photoactive materials.
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http://dx.doi.org/10.1021/acsomega.0c05240DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7807788PMC
January 2021

Predictability of leaf traits with climate and elevation: a case study in Gongga Mountain, China.

Tree Physiol 2021 Aug;41(8):1336-1352

State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Renmin South Road, Wuhou District, Chengdu 610065, China.

Leaf mass per area (Ma), nitrogen content per unit leaf area (Narea), maximum carboxylation capacity (Vcmax) and the ratio of leaf-internal to ambient CO2 partial pressure (χ) are important traits related to photosynthetic function, and they show systematic variation along climatic and elevational gradients. Separating the effects of air pressure and climate along elevational gradients is challenging due to the covariation of elevation, pressure and climate. However, recently developed models based on optimality theory offer an independent way to predict leaf traits and thus to separate the contributions of different controls. We apply optimality theory to predict variation in leaf traits across 18 sites in the Gongga Mountain region. We show that the models explain 59% of trait variability on average, without site- or region-specific calibration. Temperature, photosynthetically active radiation, vapor pressure deficit, soil moisture and growing season length are all necessary to explain the observed patterns. The direct effect of air pressure is shown to have a relatively minor impact. These findings contribute to a growing body of research indicating that leaf-level traits vary with the physical environment in predictable ways, suggesting a promising direction for the improvement of terrestrial ecosystem models.
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http://dx.doi.org/10.1093/treephys/tpab003DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8454210PMC
August 2021

Mid-infrared Raman lasers and Kerr-frequency combs from an all-silica narrow-linewidth microresonator/fiber laser system.

Opt Express 2020 Dec;28(25):38304-38316

Mid-infrared (mid-IR) lasers have great applications in bio-molecular sensing due to strong vibrational fingerprints in this wavelength range. However, it is a huge challenge to realize mid-IR lasers in conventional silica materials. Here, we demonstrate the generation of mid-IR Raman lasers and Kerr-frequency combs from an all-silica microresonator/fiber laser system. A single wavelength narrow-linewidth laser at ∼2 µm is first realized by using an ultrahigh Q-factor silica whispering-gallery-mode (WGM) microresonator as mode-selection mirror, and thulium-doped silica fiber as gain medium. Due to the strong intensity enhancement in the microresonator itself, multiple third-order nonlinear optical effects are observed, which include stimulated Stokes and anti-Stokes Raman scattering, and (cascaded) four-wave-mixing (FWM). The stimulated Stokes and anti-Stokes Raman scattering shift the initial 2 µm narrow-linewidth laser to as far as ∼2.75 µm and ∼1.56 µm, respectively. While the cascaded FWM helps to form a Kerr-frequency comb with a broad bandwidth of ∼900 nm and a mode spacing of twice of the microresonator free-spectral-range. This work offers a simple and effective route to realize all-silica mid-IR lasers based on enhanced optical nonlinearity in WGM microresonators.
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http://dx.doi.org/10.1364/OE.412157DOI Listing
December 2020

Usefulness of ultrasonography in determining the surgical excision margin in non-melanocytic skin cancer: A comparative analysis of preoperative ultrasonography and postoperative histopathology.

Medicine (Baltimore) 2020 Dec;99(51):e23789

Department of Plastic and Reconstructive Surgery.

Abstract: Skin cancer diagnoses are rising due to increasing ultraviolet ray exposure and an aging population. The complete surgical excision of skin cancer, including a normal tissue, has been the widely performed and determining the adequate safety margin is essential. In this study, we compared the preoperative thickness and width of skin cancer by ultrasonography with the measurements by histopathologic findings.A total of 211 patients were enrolled in this study and ultrasonography was performed on 30 patients. The width (long and short axis) and thickness of the skin cancers were measured using electronic calipers of ultrasonographic calipers preoperatively and microscope postoperatively.The skin cancers were basal cell carcinoma (n = 17), squamous cell carcinoma (n = 10), Merkel cell carcinoma (n = 1), mucinous carcinoma (n = 1), and sebaceous carcinoma (n = 1). The mean width (long and short axis) and thickness of the cancers measured by ultrasonography was 1.25 (0.76) cm, 0.96 (0.65) cm, and 0.37 (0.28) cm. The measurements by histopathology was 1.24 (0.84) cm, 0.95 (0.65) cm, and 0.27 (0.24) cm. Kendall's tau-b correlation coefficient between measurements by ultrasonography and histopathology was as follows: long axis, r = 0.733, P < .001; short axis, r = 0.671, P < .001; thickness, r = 0.740, P < .001. Spearman's rank correlation coefficient between measurements by ultrasonography and histopathology was as follows: long axis, r = 0.865, P < .001; short axis, r = 0.829, P < .001; thickness, r = 0.842, P < .001. The difference in mean thickness between the total excised tissue and the skin cancer was 0.29 (0.43) cm (range 0.05-0.40 cm) in basal cell carcinoma and 0.56 (0.58) cm (range 0.05-2.22 cm) in squamous cell carcinoma.Ultrasonography can accurately measure the width and thickness of skin cancer and predict the safety margins of the wide excision. Preoperative ultrasonography is a good diagnostic tool for surgical planning. Additional studies with larger populations are needed to quantify the range of vertical safety margins.
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http://dx.doi.org/10.1097/MD.0000000000023789DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7748332PMC
December 2020

Lossen Rearrangement vs C-N Reductive Elimination Enabled by Rh(III)-Catalyzed C-H Activation/Selective Lactone Ring-Opening: Chemodivergent Synthesis of Quinolinones and Dihydroisoquinolinones.

Org Lett 2020 12 4;22(24):9677-9682. Epub 2020 Dec 4.

The Fifth Affiliated Hospital, Key Laboratory of Molecular Target & Clinical Pharmacology and the State Key Laboratory of Respiratory Disease, School of Pharmaceutical Sciences, Guangzhou Medical University, Guangzhou, Guangdong 511436, China.

An unprecedented Rh(III)-catalyzed cascade C-H activation/Lossen rearrangement of aromatic amides with methyleneoxetanones has been realized along with a tunable C-N bond reductive elimination/trans esterification, giving divergent access to quinolinones and dihydroisoquinolinones via selective ring-opening of the four-membered lactone unit. Combined computational and experimental mechanistic studies defined the solvent-involved distinguished reaction paths, the origin of the observed chemodivergence, as well as the role of the substituent attached at the oxidizing directing group in tuning the reaction outcomes.
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http://dx.doi.org/10.1021/acs.orglett.0c03734DOI Listing
December 2020

Effects of a preoperative forced-air warming system for patients undergoing video-assisted thoracic surgery: A randomized controlled trial.

Medicine (Baltimore) 2020 Nov;99(48):e23424

Department of Anaesthesiology, Liaocheng People's Hospital, Liaocheng, Shandong, China.

Background: The incidence of intraoperative hypothermia is still high despite the proposal of different preventive measures during thoracoscopic surgery. This randomized control study evaluated the effects of 30-minute prewarming combined with a forced-air warming system during surgery to prevent intraoperative hypothermia in patients undergoing video-assisted thoracic surgery under general anesthesia combined with erector spinae nerve block.

Methods: Ninety-eight patients were randomly and equally allocated to prewarming or warming groups (n = 49 each). The primary outcome was the incidence of intraoperative hypothermia. Secondary outcomes were core temperature, irrigation and infused fluid, estimated blood loss, urine output, type of surgery, intraoperative anesthetic dosage, hemodynamics, recovery time, the incidence of postoperative shivering, thermal comfort, postoperative sufentanil consumption and pain intensity, patient satisfaction, and adverse events.

Results: The incidence of intraoperative hypothermia was significantly lower in the prewarming group than the warming group (12.24% vs 32.65%, P = .015). Core temperature showed the highest decrease 30 minutes after surgery start in both groups; however, the rate was lower in the prewarming than in the warming group (0.31 ± 0.04°C vs 0.42 ± 0.06°C, P < .05). Compared with the warming group, higher core temperatures were recorded for patients in the prewarming group from T1 to T6 (P < .05). Significantly fewer patients with mild hypothermia were in the prewarming group (5 vs 13, P = .037) and recovery time was significantly reduced in the prewarming group (P < .05). Although the incidence of postoperative shivering was lower in the prewarming group, it was not statistically significant (6.12% vs 18.37%, P = .064). Likewise, the shivering severity was similar for both groups. Thermal comfort was significantly increased in the prewarming group, although patient satisfaction was comparable between the 2 groups (P > .05). No adverse events occurred associated with the forced-air warming system. Both groups shared similar baseline demographics, type of surgery, total irrigation fluid, total infused fluid, estimated blood loss, urine output, intraoperative anesthetic dosage, hemodynamics, duration of anesthesia and operation time, postoperative sufentanil consumption, and pain intensity.

Conclusion: In patients undergoing video-assisted thoracic surgery, prewarming for 30 minutes before the induction of anesthesia combined with a forced-air warming system may improve perioperative core temperature and the thermal comfort, although the incidence of postoperative shivering and severity did not improve.
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http://dx.doi.org/10.1097/MD.0000000000023424DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7710179PMC
November 2020

The ZiBuPiYin recipe regulates proteomic alterations in brain mitochondria-associated ER membranes caused by chronic psychological stress exposure: Implications for cognitive decline in Zucker diabetic fatty rats.

Aging (Albany NY) 2020 11 18;12(23):23698-23726. Epub 2020 Nov 18.

Department of Emergency Medicine, Zhongshan Hospital, Dalian University, Dalian 116001, China.

Chronic psychological stress (PS) cumulatively affects memory performance through the deleterious effects on hypothalamic-pituitary-adrenal axis regulation. Several functions damaged in cognitive impairment-related diseases are regulated by mitochondria-associated ER membranes (MAMs). To elucidate the role of ZiBuPiYin recipe (ZBPYR) in regulating the MAM proteome to improve PS-induced diabetes-associated cognitive decline (PSD), differentially expressed MAM proteins were identified among Zucker diabetic fatty rats, PSD rats, and PS combined with ZBPYR administration rats via iTRAQ with LC-MS/MS. Proteomic analysis revealed that the expressions of 85 and 33 proteins were altered by PS and ZBPYR treatment, respectively. Among these, 21 proteins were differentially expressed under both PS and ZBPYR treatments, whose functional categories included energy metabolism, lipid and protein metabolism, and synaptic dysfunction. Furthermore, calcium signaling and autophagy-related proteins may play roles in the pathogenesis of PSD and the mechanism of ZBPYR, respectively. Notably, KEGG pathway analysis suggested that 'Alzheimer's disease' and 'oxidative phosphorylation' pathways may be impaired in PSD pathogenesis, while ZBPYR could play a neuroprotective role through regulating the above pathways. Overall, exposure to chronic PS contributes to the evolution of diabetes-associated cognitive decline and ZBPYR might prevent and treat PSD by regulating the MAM proteome.
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http://dx.doi.org/10.18632/aging.103894DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7762487PMC
November 2020

Silencing of lncRNA DLEU1 inhibits tumorigenesis of ovarian cancer via regulating miR-429/TFAP2A axis.

Mol Cell Biochem 2021 Feb 10;476(2):1051-1061. Epub 2020 Nov 10.

Department of Gynecology, People's Hospital of Yucheng City, No. 753, Kaituo Road, Yucheng City, Shandong, 251200, China.

Long non-coding RNAs (lncRNAs) are known as crucial regulators in the development of OC. In the current study, we aim to explore the function and molecular mechanism of lncRNA DLEU1 in OC. Quantitative real-time polymerase chain reaction (qRT-PCR) was applied to determine the expression of DLEU1, miR-429, and TFAP2A in OC cells and tissues. The relationship among DLEU1, miR-429, and TFAP2A was tested by dual-luciferase reporter (DLR) assay. Besides, the proliferative, migratory and invasive abilities of OC cells were analyzed by MTT, wound healing, and transwell assays, respectively. Western blot was performed to determine the protein expression of TFAP2A. The expression of lncRNA DLEU1 and TFAP2A were upregulated, and miR-429 was downregulated in OC tissues. Silencing of DLEU1 inhibited the proliferation, migration, and invasion of OC cells. Bioinformation and DLR assay showed that DLEU1 acted as the sponge for miR-429. Moreover, miR-429 could directly target TFAP2A and inhibit the proliferation, migration, and invasion of OC cells. Moreover, we observed a negative correlation between miR-429 and DLEU1, and between miR-429 and TFAP2A in OC tissues. The transfection of miR-429 inhibitor or pcDNA-TFAP2A reversed the inhibitory effects of si-DLEU1 on the proliferation, migration, and invasion of OC cells. Silencing of DLEU1 inhibited the proliferation, migration, and invasion of OC cells by regulating miR-429/TFAP2A axis, indicating a potential therapeutic target for OC.
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http://dx.doi.org/10.1007/s11010-020-03971-9DOI Listing
February 2021

circ_001504 promotes the development of renal cell carcinoma by sponging microRNA-149 to increase NUCB2.

Cancer Gene Ther 2021 Jun 27;28(6):667-678. Epub 2020 Oct 27.

Jilin University, 130000, Changchun, P. R. China.

Renal cell carcinoma (RCC) accounts for over 90% of primary renal tumors in adults. Although treatment approaches have steadily improved over the years, the prognosis outcome remains poor. With the aim of developing novel targets for RCC treatment, we explored the role of the circular RNA (circRNA) circ_001504 in the progression of RCC. We initially detected the expression of circ_001504 and microRNA (miRNA)-149 in RCC tissues and cells. RT-qPCR results showed that circ_001504 was highly expressed in RCC tissues, whereas miR-149 was poorly expressed. Interestingly, downregulation of circ_001504 suppressed malignant phenotypes in RCC cells, and upregulation of miR-149 exerted a similar effect. Bioinformatics analysis suggested potential binding sites between circ_001504 and miR-149, verified by a dual-luciferase reporter gene assay. Next, we identified nucleobindin 2 (NUCB2), a calcium-binding protein, as a target gene of miR-149. Furthermore, our data suggested that circ_001504 might serve as a competing endogenous RNA of miR-149, serving to elevate the expression of NUCB2. The silencing of circ_001504 resulted in decreased NUCB2 expression, which could be reversed by miR-149 inhibition. In addition, in vivo experiments demonstrated that circ_001504 depletion could suppress tumor growth in an established mouse RCC model. Collectively, reduced expression of circ_001504 lowered NUCB2 expression by sponging miR-149, thereby attenuating RCC progression, providing insight into circ_001504/miR-149/NUCB2 feedback loop into RCC treatment.
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http://dx.doi.org/10.1038/s41417-020-00247-8DOI Listing
June 2021

A high-risk airway mycobiome is associated with frequent exacerbation and mortality in COPD.

Eur Respir J 2021 03 11;57(3). Epub 2021 Mar 11.

Lee Kong Chian School of Medicine, Nanyang Technological University Singapore, Singapore

Introduction: The chronic obstructive pulmonary disease (COPD) bacteriome associates with disease severity, exacerbations and mortality. While COPD patients are susceptible to fungal sensitisation, the role of the fungal mycobiome remains uncertain.

Methods: We report the largest multicentre evaluation of the COPD airway mycobiome to date, including participants from Asia (Singapore and Malaysia) and the UK (Scotland) when stable (n=337) and during exacerbations (n=66) as well as nondiseased (healthy) controls (n=47). Longitudinal mycobiome analysis was performed during and following COPD exacerbations (n=34), and examined in terms of exacerbation frequency, 2-year mortality and occurrence of serum specific IgE (sIgE) against selected fungi.

Results: A distinct mycobiome profile is observed in COPD compared with controls as evidenced by increased α-diversity (Shannon index; p<0.001). Significant airway mycobiome differences, including greater interfungal interaction (by co-occurrence), characterise very frequent COPD exacerbators (three or more exacerbations per year) (permutational multivariate ANOVA; adjusted p<0.001). Longitudinal analyses during exacerbations and following treatment with antibiotics and corticosteroids did not reveal any significant change in airway mycobiome profile. Unsupervised clustering resulted in two clinically distinct COPD groups: one with increased symptoms (COPD Assessment Test score) and dominance, and another with very frequent exacerbations and higher mortality characterised by , and with a concomitant increase in serum sIgE levels against the same fungi. During acute exacerbations of COPD, lower fungal diversity associates with higher 2-year mortality.

Conclusion: The airway mycobiome in COPD is characterised by specific fungal genera associated with exacerbations and increased mortality.
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http://dx.doi.org/10.1183/13993003.02050-2020DOI Listing
March 2021

Design and Discovery of Natural Cyclopeptide Skeleton Based Programmed Death Ligand 1 Inhibitor as Immune Modulator for Cancer Therapy.

J Med Chem 2020 10 21;63(19):11286-11301. Epub 2020 Sep 21.

School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou 510006, China.

Blockade of immune checkpoint PD-1/PD-L1 facilitates the rescue of immune escapes of tumor cells. Though various monoclonal antibodies have been approved for clinical therapy, the development of small molecular inhibitors lags behind antibodies partially owing to the challenges of protein-protein interaction (PPI) blocker design. In this work, we adopted the skeleton of natural cyclopeptidic antibiotics gramicidin S as the start point for PD-1/PD-L1 inhibitor exploring and discovered a series of novel cyclopeptides that could interfere with the PPI of PD-1/PD-L1 based on several rounds of structural design and optimization. The representative active cyclopeptide can bind two PD-L1 and efficiently block the PD-1/PD-L1 interaction, recruit the immune cells to the tumor cells, enhance their killing against tumor cells by promoting the release of granzyme B and perforin, and display significant CD8+ T cell-dependent tumor suppression activity .
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http://dx.doi.org/10.1021/acs.jmedchem.0c01262DOI Listing
October 2020

Bedtime procrastination predicts the prevalence and severity of poor sleep quality of Chinese undergraduate students.

J Am Coll Health 2020 Jul 15:1-8. Epub 2020 Jul 15.

Research Center of Brain and Cognitive Neuroscience, Liaoning Normal University, Dalian, China.

Bedtime procrastination is a type of unhealthy sleep behavior, but whether it affects sleep quality remains unknown. The current study aimed to examine the relationship between bedtime procrastination and poor sleep quality among Chinese college students. A total of 1550 Chinese undergraduates participated and effectively completed the study. This cross-sectional study collected information on bedtime procrastination and self-reported sleep quality via the Bedtime Procrastination Scale and the Pittsburgh Sleep Quality Index. The prevalence of poor sleep quality was 39.42% among Chinese undergraduates. Age, education, and bedtime procrastination independently predicted the prevalence of poor sleep quality. Bedtime procrastination was a unique contributor to the severity of poor sleep quality. This study highlighted the independent associations between bedtime procrastination and the prevalence and severity of self-reported poor sleep quality. These findings may be helpful in designing effective measures to improve the sleep quality of college students.
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http://dx.doi.org/10.1080/07448481.2020.1785474DOI Listing
July 2020

Environmental fungal sensitisation associates with poorer clinical outcomes in COPD.

Eur Respir J 2020 08 27;56(2). Epub 2020 Aug 27.

Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore

Introduction: Allergic sensitisation to fungi such as are associated to poor clinical outcomes in asthma, bronchiectasis and cystic fibrosis; however, clinical relevance in COPD remains unclear.

Methods: Patients with stable COPD (n=446) and nondiseased controls (n=51) were prospectively recruited across three countries (Singapore, Malaysia and Hong Kong) and screened against a comprehensive allergen panel including house dust mites, pollens, cockroach and fungi. For the first time, using a metagenomics approach, we assessed outdoor and indoor environmental allergen exposure in COPD. We identified key fungi in outdoor air and developed specific-IgE assays against the top culturable fungi, linking sensitisation responses to COPD outcomes. Indoor air and surface allergens were prospectively evaluated by metagenomics in the homes of 11 COPD patients and linked to clinical outcome.

Results: High frequencies of sensitisation to a broad range of allergens occur in COPD. Fungal sensitisation associates with frequent exacerbations, and unsupervised clustering reveals a "highly sensitised fungal predominant" subgroup demonstrating significant symptomatology, frequent exacerbations and poor lung function. Outdoor and indoor environments serve as important reservoirs of fungal allergen exposure in COPD and promote a sensitisation response to outdoor air fungi. Indoor (home) environments with high fungal allergens associate with greater COPD symptoms and poorer lung function, illustrating the importance of environmental exposures on clinical outcomes in COPD.

Conclusion: Fungal sensitisation is prevalent in COPD and associates with frequent exacerbations representing a potential treatable trait. Outdoor and indoor (home) environments represent a key source of fungal allergen exposure, amenable to intervention, in "sensitised" COPD.
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http://dx.doi.org/10.1183/13993003.00418-2020DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7453645PMC
August 2020

Increased Chitotriosidase Is Associated With Aspergillus and Frequent Exacerbations in South-East Asian Patients With Bronchiectasis.

Chest 2020 08 14;158(2):512-522. Epub 2020 Mar 14.

Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore. Electronic address:

Background: Chitinase activity is an important innate immune defence mechanism against infection that includes fungi. The 2 human chitinases: chitotriosidase (CHIT1) and acidic mammalian chitinase are associated to allergy, asthma, and COPD; however, their role in bronchiectasis and bronchiectasis-COPD overlap (BCO) is unknown.

Research Question: What is the association between chitinase activity, airway fungi and clinical outcomes in bronchiectasis and bronchiectasis-COPD overlap?

Study Design And Methods: A prospective cohort of 463 individuals were recruited across five hospital sites in three countries (Singapore, Malaysia, and Scotland) including individuals who were not diseased (n = 35) and who had severe asthma (n = 54), COPD (n = 90), bronchiectasis (n = 241) and BCO (n = 43). Systemic chitinase levels were assessed for bronchiectasis and BCO and related to clinical outcomes, airway Aspergillus status, and underlying pulmonary mycobiome profiles.

Results: Systemic chitinase activity is elevated significantly in bronchiectasis and BCO and exceed the activity in other airway diseases. CHIT1 activity strongly predicts bronchiectasis exacerbations and is associated with the presence of at least one Aspergillus species in the airway and frequent exacerbations (≥3 exacerbations/y). Subgroup analysis reveals an association between CHIT1 activity and the "frequent exacerbator" phenotype in South-East Asian patients whose airway mycobiome profiles indicate the presence of novel fungal taxa that include Macroventuria, Curvularia and Sarocladium. These taxa, enriched in frequently exacerbating South-East Asian patients with high CHIT1 may have potential roles in bronchiectasis exacerbations.

Interpretation: Systemic CHIT1 activity may represent a useful clinical tool for the identification of fungal-driven "frequent exacerbators" with bronchiectasis in South-East Asian populations.
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http://dx.doi.org/10.1016/j.chest.2020.02.048DOI Listing
August 2020

"High-Risk" Clinical and Inflammatory Clusters in COPD of Chinese Descent.

Chest 2020 07 22;158(1):145-156. Epub 2020 Feb 22.

Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore. Electronic address:

Background: COPD is a heterogeneous disease demonstrating inter-individual variation. A high COPD prevalence in Chinese populations is described, but little is known about disease clusters and prognostic outcomes in the Chinese population across Southeast Asia. We aim to determine if clusters of Chinese patients with COPD exist and their association with systemic inflammation and clinical outcomes.

Research Question: We aim to determine if clusters of Chinese patients with COPD exist and their association with clinical outcomes and inflammation.

Study Design And Methods: Chinese patients with stable COPD were prospectively recruited into two cohorts (derivation and validation) from six hospitals across three Southeast Asian countries (Singapore, Malaysia, and Hong Kong; n = 1,480). Each patient was followed more than 2 years. Clinical data (including co-morbidities) were employed in unsupervised hierarchical clustering (followed by validation) to determine the existence of patient clusters and their prognostic outcome. Accompanying systemic cytokine assessments were performed in a subset (n = 336) of patients with COPD to determine if inflammatory patterns and associated networks characterized the derived clusters.

Results: Five patient clusters were identified including: (1) ex-TB, (2) diabetic, (3) low comorbidity: low-risk, (4) low comorbidity: high-risk, and (5) cardiovascular. The cardiovascular and ex-TB clusters demonstrate highest mortality (independent of Global Initiative for Chronic Obstructive Lung Disease assessment) and illustrate diverse cytokine patterns with complex inflammatory networks.

Interpretation: We describe clusters of Chinese patients with COPD, two of which represent high-risk clusters. The cardiovascular and ex-TB patient clusters exhibit high mortality, significant inflammation, and complex cytokine networks. Clinical and inflammatory risk stratification of Chinese patients with COPD should be considered for targeted intervention to improve disease outcomes.
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http://dx.doi.org/10.1016/j.chest.2020.01.043DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7339237PMC
July 2020

Degradation of intracellular TGF-β1 by PROTACs efficiently reverses M2 macrophage induced malignant pathological events.

Chem Commun (Camb) 2020 Mar;56(19):2881-2884

School of Pharmaceutical Sciences, Sun Yat-sen University, GuangZhou 510006, China.

The first proteolysis targeting chimeras for the intracellular elimination of transforming growth factor-β1 (TGF-β1), which contributes to various diseases, are described. The appropriately designed DT-6 could efficiently degrade intracellular TGF-β1, and inhibit M2 macrophage induced epithelial to mesenchymal transition and invasive migration of cancer cells.
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http://dx.doi.org/10.1039/c9cc08391jDOI Listing
March 2020

Rhodium(III)-Catalyzed Enantio- and Diastereoselective C-H Cyclopropylation of N-Phenoxylsulfonamides: Combined Experimental and Computational Studies.

Angew Chem Int Ed Engl 2020 02 7;59(7):2890-2896. Epub 2020 Jan 7.

Key Laboratory of Applied Surface and Colloid Chemistry of MOE, School of Chemistry and Chemical Engineering, Shaanxi Normal University (SNNU), Xi'an, 710062, P. R. China.

Cyclopropane rings are a prominent structural motif in biologically active molecules. Enantio- and diastereoselective construction of cyclopropanes through C-H activation of arenes and coupling with readily available cyclopropenes is highly appealing but remains a challenge. A dual directing-group-assisted C-H activation strategy was used to realize mild and redox-neutral Rh -catalyzed C-H activation and cyclopropylation of N-phenoxylsulfonamides in a highly enantioselective, diastereoselective, and regioselective fashion with cyclopropenyl secondary alcohols as a cyclopropylating reagent. Synthetic applications are demonstrated to highlight the potential of the developed method. Integrated experimental and computational mechanistic studies revealed that the reaction proceeds via a Rh nitrenoid intermediate, and Noyori-type outer sphere concerted proton-hydride transfer from the secondary alcohol to the Rh=N bond produces the observed trans selectivity.
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http://dx.doi.org/10.1002/anie.201913794DOI Listing
February 2020

Redox-Neutral [4 + 2] Annulation of -Methoxybenzamides with Alkynes Enabled by an Osmium(II)/HOAc Catalytic System.

Org Lett 2019 12 5;21(24):9904-9908. Epub 2019 Dec 5.

Guangzhou Municipal and Guangdong Provincial Key Laboratory of Protein Modification and Degradation & Molecular Target and Clinical Pharmacology, State Key Laboratory of Respiratory Disease, School of Pharmaceutical Sciences & the Fifth Affiliated Hospital , Guangzhou Medical University , Guangzhou , Guangdong 511436 , China.

By making use of a direct C-H activation strategy, an efficient osmium(II)-catalyzed redox-neutral [4 + 2] annulation of -methoxybenzamides with alkynes has been accomplished. Computational and experimental studies revealed that such transformation leading to the synthesis of the isoquinolone core might follow an Os(II)-Os(IV)-Os(II) catalytic pathway, in which an unusual HOAc-assisted oxidative addition of osmium(II) into the N-O bond to generate the osmium(IV) species was involved as one of the key transition states. Further exploration of divergent C-H activation reaction modes enabled by the osmium(II) catalyst has also been exemplified for one-pot assembly of other either linear or cyclic products.
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http://dx.doi.org/10.1021/acs.orglett.9b03827DOI Listing
December 2019

Detection of breast cancer-derived exosomes using the horseradish peroxidase-mimicking DNAzyme as an aptasensor.

Analyst 2019 Dec;145(1):107-114

Lab of Biosystem and Microanalysis, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China.

Exosomes are membrane-enclosed phospholipid extracellular vesicles with a variety of tumor antigens which can be applied in the diagnosis and treatment of cancer due to the high secretion on the surface of cancer cells. Until now, many research studies on exosomes have been reported, but convenient and low-cost detection methods still need to be developed. Recently, we have developed a sensitive, simple and low-cost colorimetric aptasensor by designing a hairpin-like structure, which combined the highly specific MUC1 aptamer with a hemin/G-quadruplex for the detection of breast cancer exosomes. The hemin/G-quadruplex toward H2O2 reduction was used to generate an evidently strong colorimetric response owing to acting as a HRP-mimicking DNAzyme. The aptasensor is regarded as an "on-off" type switch, which strictly controls the process of reaction responding to the existence or not of exosomes. In our study, associated exosome detection limits are 3.94 × 105 particles per mL, which showed a higher sensitivity compared to commercial ELISA. Our method not only exhibited the advantages of being convenient and time-saving, with few instruments used, but also the signal generated using this method can be easily observed by the naked eye. Furthermore, the proposed strategy can well differentiate breast cancer patients from healthy individuals, demonstrating potential application in the analysis of clinical specimens.
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http://dx.doi.org/10.1039/c9an01653hDOI Listing
December 2019

Direct generation of orthogonally polarized dual-wavelength continuous-wave and passively Q-switched vortex beam in diode-pumped Pr:YLF lasers.

Opt Lett 2019 Nov;44(22):5586-5589

We report on direct generation of an orthogonally polarized dual-wavelength vortex laser, for the first time to our knowledge, by means of a diode-pumped V-shaped Pr:YLF laser platform. A method of misaligning the folded mirror is proposed to realize the simultaneous orthogonally polarized dual-wavelength laser, while a method of orthogonally rotating the laser gain medium is proposed to generate an intracavity vortex beam (LG mode). With the two methods, in continuous-wave (CW) mode, we have achieved simultaneous lasing of an orthogonally polarized dual-wavelength vortex laser at 604 and 607 nm with maximum output power of 237.7 mW. Moreover, based on this operation, a simultaneous orthogonally polarized dual-wavelength passively Q-switched vortex laser is also realized by inserting a Co:ASL crystal into the laser resonator as a saturable absorber. This work provides the simplest way for direct generation of an orthogonally polarized dual-wavelength vortex laser for potential applications.
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http://dx.doi.org/10.1364/OL.44.005586DOI Listing
November 2019

Compact all-fiber 2.1-2.7 m tunable Raman soliton source based on germania-core fiber.

Opt Express 2019 Sep;27(20):28544-28550

Although ultrafast rare-earth-doped fiber lasers mode-locked at near-infrared and ∼3 m wavelengths have been well developed, it is relatively difficult to achieve ultrafast fiber laser emitting in the 2.1-2.7 m spectral gap between ∼2 m (Tm fiber) and ∼2.8 m (Er or Ho fluoride fiber). In this paper, we report the generation of 2.1-2.7 m tunable femtosecond Raman solitons from a compact fusion-spliced all-fiber system using a home-made 1.96 m ultrafast pump source and a MIR-available germania-core fiber. At first, a Tm-doped double-clad fiber amplifier is used to not only boost up the power of 1957 nm femtosecond seed laser, but also to generate the first-order soliton self-frequency shift (SSFS). The first-order Raman solitons can be tuned from 2.036 to 2.152 m, have a pulse duration of ∼480 fs and can reach a pulse energy of 1.07 nJ. The first-order Raman solitons are further injected into a 94 mol. germania-core fiber to excite the second-order SSFS. The second-order solitons can be tuned to longer wavelengths, i.e. from 2.157 m up to 2.690 m. Our work could provide an effective way to develop compact, all-fiber ultrafast MIR laser sources with the continuous wavelength tuning of 2.1-2.7 m.
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http://dx.doi.org/10.1364/OE.27.028544DOI Listing
September 2019
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