Publications by authors named "Xiang Ren"

270 Publications

MoSe/CdSe Heterojunction Destruction by Cation Exchange for Photoelectrochemical Immunoassays with a Controlled-Release Strategy.

Anal Chem 2021 Jul 20. Epub 2021 Jul 20.

Collaborative Innovation Center for Green Chemical Manufacturing and Accurate Detection, Key Laboratory of Interfacial Reaction & Sensing Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, Shandong, China.

Herein, a split-type immunoassay strategy instigated by cation exchange (CE) and changing the capacity of an electron donor in an electrolyte solution is optimized, namely, for differentiating the biological-specific binding assay and photoelectrochemical (PEC) analysis. MoSe/CdSe, a Z-scheme heterojunction with efficient visible light absorption and a low recombination of carriers, is used as a photoelectrode substrate. Silver ions (Ag) as the initiator of CE are generated by the acidolysis of evenly loaded silver nanoparticles on mesoporous silica nanospheres (MSNs). The theoretical calculation and experimental results confirm that Ag replaces Cd in CdSe and retains the crystal structure of MoSe. However, this behavior destroys the perfectly matched heterojunction structure and introduces defects, which led to the reduction of the photocurrent response. In addition, ascorbate oxidase in combination with MSNs can be used as a consumptive agent of the electron donor, which further improves the sensitivity and reliability of the sensor. As a proof of principle, neuron-specific enolase was applied to elucidate the potential application of the PEC immunoassay in clinical diagnosis, and the obtained linear range of the sensor was from 0.0001 to 100 ng/mL with a detection limit of 28 fg/mL (S/N = 3).
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http://dx.doi.org/10.1021/acs.analchem.1c02354DOI Listing
July 2021

Peptide-Based Biosensor with a Luminescent Copper-Based Metal-Organic Framework as an Electrochemiluminescence Emitter for Trypsin Assay.

Anal Chem 2021 Jul 9;93(28):9704-9710. Epub 2021 Jul 9.

Collaborative Innovation Center for Green Chemical Manufacturing and Accurate Detection, Key Laboratory of Interfacial Reaction & Sensing Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan, Shandong 250022, China.

A copper-based metal-organic framework (JUC-1000) has emerged as a promising electrochemiluminescence (ECL) emitter in the domains of bioanalysis and immunoassay. Herein, a highly efficient signal "on-off" peptide-based biosensor was constructed for trypsin (TPN) assay. JUC-1000 synthesized using an organic ligand of HBDPO was functionalized as the ECL emitter, whose cathodic ECL behavior in aqueous media was first investigated using potassium persulfate (KSO) as the coreactant. To further amplify the ECL signal, highly catalytic [email protected] nanoparticles were fabricated as both a substrate and an coreaction accelerator, which can efficiently catalyze the reduction of SO to generate more sulfate anion radicals (SO) for ECL enhancement, thereby generating strong and stable ECL signals in a "signal on" state. The functionalized JUC-1000 emitter was connected to the [email protected] sensing layer though a heptapeptide (HWRGWVC, HGC), and TPN as the target can specifically cleave the carboxyl side of arginine residues in HGC, leading to the release of emitters in a "signal off" state. Based on the efficient signal-switching, the biosensor exhibited linear ECL responses to the added TPN concentration, realizing sensitive detection of TPN in 10 fg/mL to 100 ng/mL with a limit of detection of 3.46 fg/mL. This work proposed an attractive orientation for the fundamental research of applying transition metal-organic frameworks as ECL emitters in bioanalysis and immunoassay.
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http://dx.doi.org/10.1021/acs.analchem.1c00850DOI Listing
July 2021

Rapid and sensitive detection of acetone in exhaled breath through the ambient reaction with water radical cations.

Analyst 2021 Jul 6. Epub 2021 Jul 6.

Jiangxi Key Laboratory for Mass Spectrometry and Instrumentation, East China University of Technology, Nanchang, 330013, P. R. China.

The levels of acetone and other ketones in exhaled human breath can be associated with various metabolic conditions, e.g. ketosis, lung cancer, dietary fat loss and diabetes. In this study, ketones in breath samples were charged through the reaction with water radical cations to form [M + H2O]˙+ ions, which were detected by mass spectrometry. Our experimental data indicate that under the optimized experimental conditions, the limit of detection for acetone using our approach is 0.14 ng L-1 (∼0.06 ppb). The linear dynamic range of detection spans four orders of magnitude. The developed approach was applied to real-time semi-quantitative analysis of acetone in the exhaled breath of human volunteers, revealing significantly higher levels of acetone in the breath of smokers compared to non-smokers. The developed approach features the obviation of sample collection, easy operation, high speed of analysis (10 s per run), high sensitivity, and spectral interpretation, which indicates the potential of ambient corona discharge ionization mass spectrometry as a selective, sensitive and noninvasive technique for the determination of exhaled ketones in clinical diagnosis including lung cancer, diabetes, etc.
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http://dx.doi.org/10.1039/d1an00402fDOI Listing
July 2021

Hollow performances quenching label of Au [email protected] nanoboxes-based sandwich photoelectrochemical immunosensor for sensitive CYFRA 21-1 detection.

Talanta 2021 Oct 27;233:122552. Epub 2021 May 27.

Collaborative Innovation Center for Green Chemical Manufacturing and Accurate Detection, Key Laboratory of Interfacial Reaction & Sensing Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan, 250022, PR China. Electronic address:

In this work, a fire-new "signal-off" type photoelectrochemical (PEC) immunosensor based on bismuth sulfide/iodine doped bismuth oxychloride (BiS/I:BiOCl) heterostructure as a platform and Au nanoparticles loaded hollow CoSnO nanoboxes (Au [email protected]) as quenching label was designed, for sensitive detection of CYFRA 21-1. The I:BiOCl with flower-like structure could supply high specific surface area for loading nanometer materials. Then, BiS was formed in-situ by S adsorption on the surface of I:BiOCl by dangling bond of Bi, but did not change the flower-like structure of I:BiOCl. Then, n-type BiS and p-type I:BiOCl heterostructure showed good photoelectric behavior by providing an additional electric field to accelerate electron-hole separation. Furthermore, the production process of the heterostructure was simple, fast, low temperature, and without complex raw materials. The Au [email protected] with good photocatalytic activity could strongly compete with BiS/I:BiOCl for electron donor of ascorbic acid (AA). Meanwhile, the CoSnO with hollow structure made the quenching effect more significant by the light-scattering effect that enhanced the light absorption capacity and shorten distance of carrier transport. Under optimal conditions, this proposed strategy displayed the low detection limit of 30 fg/mL, with a high linearity range from 100 fg/mL to 100 ng/mL for tumor markers CYFRA 21-1. Simultaneously, it also exhibited excellent specificity and acceptable stability, which might provide a new perspective for the fabrication of other PEC immunosensors with heterostructure simple synthesis and hollow materials.
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http://dx.doi.org/10.1016/j.talanta.2021.122552DOI Listing
October 2021

Ultrasensitive near-infrared electrochemiluminescence biosensor derived from Eu-MOF with antenna effect and high efficiency catalysis of specific CoS hollow triple shelled nanoboxes for procalcitonin.

Biosens Bioelectron 2021 Jun 11;191:113409. Epub 2021 Jun 11.

Collaborative Innovation Centre for Green Chemical Manufacturing and Accurate Detection School of Chemistry and Chemical Engineering, University of Jinan, Jinan, 250022, Shandong, China; Key Laboratory of Interfacial Reaction & Sensing Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan, 250022, Shandong, China.

In this paper, we report a novel multiple amplification strategy for ultrasensitive near-infrared electrochemiluminescence (ECL) immunoassay in KSO solution. The realization of this strategy is based on the antenna effect of Eu-MOF (EuBTC) and a high efficiency catalysis of CoS hollow triple shelled nanoboxes (TSNBs). The HBTC ligand in the antenna effect first undergoes π-π* absorption and a singlet-singlet electronic transition. Its energy passes through the intersystem to the triplet state, next transfers from the lowest excited triplet state to the vibrational energy level of the rare earth ion, finally realizing sensitizing center ion luminescence. Moreover, ionic reaction and structural advantages endow CoS TSNBs a dual signal enhancement effect. This sandwich-type ECL biosensor has a near-infrared luminescence in 800-900 nm, thus avoiding damage to the sample in the meantime. In practical diagnosis, the normal critical value of procalcitonin (PCT) (<0.5 ng/mL) is much higher than the detection limit (3.65 fg/mL) and is in the detection range (10 fg/mL-100 ng/mL), which means that the ECL biosensor has a high sensitivity in the detection of PCT and meet the requirement for diagnosis of disease completely. Therefore, the strategy provides a feasible method for efficient and stable analysis of systemic inflammatory response such as fearful bacterial infection, hepatitis B, and peritonitis.
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http://dx.doi.org/10.1016/j.bios.2021.113409DOI Listing
June 2021

Rare Self-Luminous Mixed-Valence Eu-MOF with a Self-Enhanced Characteristic as a Near-Infrared Fluorescent ECL Probe for Nondestructive Immunodetection.

Anal Chem 2021 06 11;93(24):8613-8621. Epub 2021 Jun 11.

Collaborative Innovation Centre for Green Chemical Manufacturing and Accurate Detection School of Chemistry and Chemical Engineering, Key Laboratory of Interfacial Reaction & Sensing Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan, 250022 Shandong, China.

Steady and efficient sensitized emission of Eu to Eu can be achieved through a rare mixed-valence Eu-MOF (LEuEu). Compared with the sensitization of other substances, the similar ion radius and configuration of the extranuclear electron between Eu and Eu make sensitization easier and more efficient. The sensitization of Eu to Eu is of great assistance for the self-enhanced luminescence of LEuEu, the longer luminous time, and the more stable electrochemiluminescence (ECL) signal. Simultaneously, LEuEu possesses near-infrared (NIR) fluorescence of around 900 nm and a mighty self-luminous characteristic, which render it useful as a NIR fluorescent probe and as a luminophore to establish a NIR ECL biosensor. This NIR biosensor can greatly reduce the damage to the detected samples and even achieve a nondestructive test and improve the detection sensitivity by virtue of strong susceptibility and environmental suitability of NIR. In addition, the [email protected] triple-shelled microspheres further enhanced the ECL intensity due to two redox pairs of Ce/Ce and Co/Co. The NIR ECL biosensor based on these strategies owns an ultrasensitive detection ability of CYFRA 21-1 with a low limit of detection of 1.70 fg/mL and also provides a novel idea for the construction of a highly effective nondestructive immunodetection biosensor.
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http://dx.doi.org/10.1021/acs.analchem.1c01531DOI Listing
June 2021

Split-Type Electrochemical Immunoassay System Triggering Ascorbic Acid-Mediated Signal Magnification Based on a Controlled-Release Strategy.

ACS Appl Mater Interfaces 2021 Jun 8;13(24):29179-29186. Epub 2021 Jun 8.

Collaborative Innovation Center for Green Chemical Manufacturing and Accurate Detection, Key Laboratory of Interfacial Reaction & Sensing Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan, 250022 Shandong, China.

This research put forward a novel split-type electrochemical (EC) immunosensor which integrated the controlled-release strategy with EC detection for application in the field of biosensing. Concretely, ascorbic acid (AA) was packaged in a cadmium sulfide (CdS)-capped spherical mesoporous bioactive glass (SBG) nanocarrier (SBG) on account of encapsulation technology. To reduce the complexity of the bioanalysis, the detection antibody-labeled SBG-AA bioconjugate was applied in a 96-well microplate for the immunoreaction process, which is independent of the EC determination procedure. Thus, the immune interference and steric hindrance caused by the accumulation of nanomaterials on the electrode could be minimized. Subsequently, AA was released efficiently via the destruction effect of dithiothreitol on the disulfide bond. In addition, for the as-prepared FcAI/l-Cys/gold nanoparticles (GNPs)/porous BiVO (p-BVO)/ITO EC sensing platform in the detection solution, the synergetic catalysis of Fc and GNPs/p-BVO toward the oxidation of the released AA could be realized, which triggered AA-mediated significant signal magnification throughout this study. In particular, p-BVO with an ordered nanoarray structure could accelerate the electron transfer to assist in sensitivity improvement of this system. This novel biosensor was capable of assaying the neuron-specific enolase (NSE) biomarker sensitively, from which a linear range of 0.001-100 ng/mL was derived along with a low detection limit of 1.08 pg/mL. An innovative way could be paved in the bioanalysis of NSE and other biomarkers.
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http://dx.doi.org/10.1021/acsami.1c07780DOI Listing
June 2021

Stimulation of AMPK Prevents Diabetes-Induced Photoreceptor Cell Degeneration.

Oxid Med Cell Longev 2021 13;2021:5587340. Epub 2021 May 13.

Department of Histology and Embryology, College of Basic Medicine, Dalian Medical University, Dalian, 116044 LiaoNing Province, China.

Diabetic retinopathy (DR) is a kind of severe retinal neurodegeneration. The advanced glycation end products (AGEs) affect autophagy, and mitochondrial function is involved in DR. Adenosine-activated protein kinase (AMPK) is an important metabolic sensor that can regulate energy homeostasis in cells. However, the effect of AMPK in DR is still not fully understood. In this study, we investigated the effect of AMPK on diabetes-induced photoreceptor cell degeneration. , a diabetic mouse model was established by streptozotocin (STZ) injection. Haematoxylin-eosin (HE) staining was used to observe retinal morphology and measure the thicknesses of different layers in the retina. Electroretinogram (ERG) was used to evaluate retinal function. , 661w cells were treated with AGEs with/without an AMPK agonist (metformin) or AMPK inhibitor (compound C). Flow cytometry and CCK-8 assays were used to analyse apoptosis. Mitochondrial membrane potential was analysed by JC-1. Western blotting and qRT-PCR were used to examine the expression of related proteins and genes, respectively. The wave amplitude and the thickness of the outer nuclear layer were decreased in diabetic mice. The expression of rhodopsin and opsin was also decreased in diabetic mice. , the percentage of apoptotic cells was increased, the expression of the apoptosis-related protein Bax was increased, and Bcl-2 was decreased after AGE treatment in 661w cells. The expression of the autophagy-related protein LC3 was decreased, and p62 was increased. The mitochondrial-related gene expression and membrane potential were decreased, and mitochondrial morphology was abnormal, as observed by TEM. However, AMPK stimulation ameliorated this effect. These results indicate that AMPK stimulation can delay diabetes-induced photoreceptor degeneration by regulating autophagy and mitochondrial function.
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http://dx.doi.org/10.1155/2021/5587340DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8140850PMC
May 2021

Thioredoxin-1 Is a Target to Attenuate Alzheimer-Like Pathology in Diabetic Encephalopathy by Alleviating Endoplasmic Reticulum Stress and Oxidative Stress.

Front Physiol 2021 17;12:651105. Epub 2021 May 17.

Department of Histology and Embryology, College of Basic Medical Sciences, Dalian Medical University, Dalian, China.

Varying degrees of central nervous system neuropathy induced by diabetes mellitus (DM) contribute to a cognitive disorder known as diabetic encephalopathy (DE), which is also one of the independent risk factors for Alzheimer's disease (AD). Endoplasmic reticulum stress (ERS) plays a critical role in the occurrence and development of DE and AD. However, its molecular mechanism remains largely unknown. This study aims to investigate whether thioredoxin-1 (Trx-1) could alleviate DE and AD through ERS, oxidative stress (OS) and apoptosis signaling pathways. Mice were randomly divided into a wild-type group (WT-NC), a streptozotocin (STZ)-treated DM group (WT-DM), a Trx-1-TG group (TG-NC) and a Trx-1-TG DM group (TG-DM). Diabetic animals showed an increase in the time spent in the target quadrant and the number of platform crossings as well as AD-like behavior in the water maze experiment. The immunocontent of the AD-related protein Tau and the levels of cell apoptosis, β-amyloid (Aβ) plaque formation and neuronal degeneration in the hippocampus of the diabetic group were increased. Some key factors associated with ERS, such as protein disulfide isomerase (PDI), glucose-regulated protein 78 (GRP78), inositol-requiring enzyme 1α (IRE1α), tumor necrosis factor receptor-associated factor 2 (TRAF2), apoptosis signal-regulating kinase-1 (ASK1), c-Jun N-terminal kinase (JNK), protein kinase RNA (PKR)-like ER kinase (PERK), and C/EBP homologous protein (CHOP), were upregulated, and other factors related to anti-oxidant stress, such as nuclear factor erythroid 2-related factor (Nrf2), were downregulated in the DM group. Moreover, DM caused an increase in the immunocontents of caspase-3 and caspase-12. However, these changes were reversed in the Trx-1-tg DM group. Therefore, we conclude that Trx-1 might be a key factor in alleviating DE and AD by regulating ERS and oxidative stress response, thus preventing apoptosis.
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http://dx.doi.org/10.3389/fphys.2021.651105DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8166324PMC
May 2021

Etiological, epidemiological, and clinical features of acute diarrhea in China.

Nat Commun 2021 04 29;12(1):2464. Epub 2021 Apr 29.

The Institute for Disease Prevention and Control of PLA, Beijing, China.

National-based prospective surveillance of all-age patients with acute diarrhea was conducted in China between 2009‒2018. Here we report the etiological, epidemiological, and clinical features of the 152,792 eligible patients enrolled in this analysis. Rotavirus A and norovirus are the two leading viral pathogens detected in the patients, followed by adenovirus and astrovirus. Diarrheagenic Escherichia coli and nontyphoidal Salmonella are the two leading bacterial pathogens, followed by Shigella and Vibrio parahaemolyticus. Patients aged <5 years had higher overall positive rate of viral pathogens, while bacterial pathogens were more common in patients aged 18‒45 years. A joinpoint analysis revealed the age-specific positivity rate and how this varied for individual pathogens. Our findings fill crucial gaps of how the distributions of enteropathogens change across China in patients with diarrhea. This allows enhanced identification of the predominant diarrheal pathogen candidates for diagnosis in clinical practice and more targeted application of prevention and control measures.
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http://dx.doi.org/10.1038/s41467-021-22551-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8085116PMC
April 2021

Self-Powered Cathodic Photoelectrochemical Aptasensor Comprising a Photocathode and a Photoanode in Microfluidic Analysis Systems.

Anal Chem 2021 05 28;93(18):7125-7132. Epub 2021 Apr 28.

Department of Pediatric Surgery, Shandong Provincial Hospital Affliated to Shandong University, Jinan, Shandong 250021, P. R. China.

An intriguing self-powered cathodic photoelectrochemical (PEC) microfluidic aptasensor with enhanced cathodic photocurrent response is proposed for sensitive detection of prostate-specific antigen (PSA). The self-powered system is constructed by a cadmium sulfide-sensitized zinc oxide nanorod array (CdS/ZnO NA) as a photoanode with an iodide-doped bismuth oxychloride flower-array (I:BiOCI) as a photocathode, which can generate the electrical output under visible light irradiation with no external power supply. In addition, the p-type semiconductor I:BiOCI with a special internal electric field between the iodide ion layer and the [BiO] layer could increase the cathodic photocurrent response by facilitating the separation of electron/hole pairs under visible light excitation. It is worth noting that dissolved oxygen as an electron acceptor can be reduced by the photogenerated electron to form a superoxide radical (O) in the self-powered cathodic PEC system. The further enhanced cathodic photocurrent response can be achieved by eliminating O that reacts with the luminol anion radical (L) to produce chemiluminescence emission, which serves as an inner excitation light source. What is more exciting is that the integration of the photoanode and the photocathode into a microfluidic chip could realize automatic sample injection and detection. On this basis, the proposed aptasensor presents excellent reproducibility and high sensitivity for detecting PSA and exhibits a good linearity range (50 fg·mL to 50 ng·mL) with a low detection limit (25.8 fg·mL), which opens up a new horizon of potential for sensitively detecting other kinds of disease markers.
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http://dx.doi.org/10.1021/acs.analchem.1c01038DOI Listing
May 2021

delays light-induced photoreceptor degeneration through antioxidant and antiapoptotic properties.

Exp Ther Med 2021 Jun 31;21(6):576. Epub 2021 Mar 31.

Department of Histology and Embryology, College of Basic Medicine, Dalian Medical University, Dalian, Liaoning 116044, P.R. China.

Intense exposure to artificial bright light increases the risk of retinal damage resulting in blurred vision and blindness. Long-term exposure to bright light elevates oxidative stress-induced apoptosis, which results in photoreceptor cell degeneration. However, to the best of our knowledge, the molecular mechanism associated with light-induced retinopathy remains unclear. In the present study, the mechanisms involved in light-induced oxidative stress and apoptosis were investigated along with the protective effects of (EGb 761) in photoreceptor cell degeneration. EGb 761 was administered to mice at a dose of 50 or 100 mg/kg for 7 days prior to exposure to bright light (5,000 lux for 24 h). Furthermore, photoreceptor cell disorders were evaluated using electroretinogram (ERG) and H&E staining analyses. The expression levels of antioxidant genes and proteins ERK, thioredoxin (Trx) and nuclear factor erythroid 2-related factor 2 (Nrf-2) and the induction of apoptosis cytochrome c (Cyc), cleaved caspase-3 and Bax, were determined by reverse transcription-quantitative PCR and western blotting. ERG and histological analysis revealed that exposure to bright light induced functional and morphological changes to the photoreceptor cells. Exposure to bright light increased the levels of Cyc, cleaved caspase-3 and Bax, and decreased the levels of phosphorylated (p-) Erk, Nrf-2 and thioredoxin (Trx). However, treatment of mice with EGb 761 increased the expression levels of antiapoptotic (Bcl-2) and antioxidant (p-Erk, Trx and Nrf-2) proteins and decreased the expression levels of the apoptotic genes (Cyc, cleaved caspase-3 and Bax). Based on these findings, the present study suggested that prolonged exposure to light induces photoreceptor cell degeneration, where EGb 761 treatment may serve a therapeutic effect on the development of photoreceptor cell degeneration.
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http://dx.doi.org/10.3892/etm.2021.10008DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8027744PMC
June 2021

Risk factors for developing severe COVID-19 in China: an analysis of disease surveillance data.

Infect Dis Poverty 2021 Apr 12;10(1):48. Epub 2021 Apr 12.

Division of Infectious Diseases, Chinese Center for Disease Control and Prevention, Beijing, China.

Background: COVID-19 has posed an enormous threat to public health around the world. Some severe and critical cases have bad prognoses and high case fatality rates, unraveling risk factors for severe COVID-19 are of significance for predicting and preventing illness progression, and reducing case fatality rates. Our study focused on analyzing characteristics of COVID-19 cases and exploring risk factors for developing severe COVID-19.

Methods: The data for this study was disease surveillance data on symptomatic cases of COVID-19 reported from 30 provinces in China between January 19 and March 9, 2020, which included demographics, dates of symptom onset, clinical manifestations at the time of diagnosis, laboratory findings, radiographic findings, underlying disease history, and exposure history. We grouped mild and moderate cases together as non-severe cases and categorized severe and critical cases together as severe cases. We compared characteristics of severe cases and non-severe cases of COVID-19 and explored risk factors for severity.

Results: The total number of cases were 12 647 with age from less than 1 year old to 99 years old. The severe cases were 1662 (13.1%), the median age of severe cases was 57 years [Inter-quartile range(IQR): 46-68] and the median age of non-severe cases was 43 years (IQR: 32-54). The risk factors for severe COVID-19 were being male [adjusted odds ratio (aOR) = 1.3, 95% CI: 1.2-1.5]; fever (aOR = 2.3, 95% CI: 2.0-2.7), cough (aOR = 1.4, 95% CI: 1.2-1.6), fatigue (aOR = 1.3, 95% CI: 1.2-1.5), and chronic kidney disease (aOR = 2.5, 95% CI: 1.4-4.6), hypertension (aOR = 1.5, 95% CI: 1.2-1.8) and diabetes (aOR = 1.96, 95% CI: 1.6-2.4). With the increase of age, risk for the severity was gradually higher [20-39 years (aOR = 3.9, 95% CI: 1.8-8.4), 40-59 years (aOR = 7.6, 95% CI: 3.6-16.3), ≥ 60 years (aOR = 20.4, 95% CI: 9.5-43.7)], and longer time from symtem onset to diagnosis [3-5 days (aOR = 1.4, 95% CI: 1.2-1.7), 6-8 days (aOR = 1.8, 95% CI: 1.5-2.1), ≥ 9 days(aOR = 1.9, 95% CI: 1.6-2.3)].

Conclusions: Our study showed the risk factors for developing severe COVID-19 with large sample size, which included being male, older age, fever, cough, fatigue, delayed diagnosis, hypertension, diabetes, chronic kidney diasease, early case identification and prompt medical care. Based on these factors, the severity of COVID-19 cases can be predicted. So cases with these risk factors should be paid more attention to prevent severity.
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http://dx.doi.org/10.1186/s40249-021-00820-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8040359PMC
April 2021

Dual-Mode Sensing Platform Guided by Intramolecular Electrochemiluminescence of a Ruthenium Complex and Cationic ,-Bis(2-(trimethylammonium iodide)propylene) Perylene-3,4,9,10-tetracarboxydiimide for Estradiol Assay.

Anal Chem 2021 04 7;93(15):6088-6093. Epub 2021 Apr 7.

Collaborative Innovation Center for Green Chemical Manufacturing and Accurate Detection, University of Jinan, Jinan 250022, P. R. China.

Herein, a dual-mode sensing platform using cationic ,-bis(2-(trimethylammonium iodide)propylene)perylene-3,4,9,10-tetracarboxydiimide (PDA)-assembled DNA strands as a quencher was suggested for estradiol (E2) detection. The aptamer chain was initially anchored with the Ru(II) novel molecule (Ru complex), which was recombined with carbohydrazide (CONH) and tris(4,4'-dicarboxylicacid-2,2'-bipyridyl)ruthenium(II) dichloride [Ru(dcbpy)] modified on copper oxide (CuO) nanospheres. Intramolecular electrochemiluminescence (ECL) occurring between CONH and Ru(dcbpy) effectively improved the reaction rate and increased the ECL efficiency. By employing effective van der Waals' force, PDA was endowed with an efficient ECL quenching probe on an electrode. The signal on the ECL interface can be converted into quenching because of energy transfer between the intercalator and the emitter. Notably, cationic PDA possessing a large planar π-π skeleton improved advantageous activity of redox and DNA aptamer indurative loading capacity and directly generated a well-defined cathodic peak to execute the EC bio-detection. This method not only avoids the difficulty of assembling various signal indicators but also improves the sensitivity greatly using the quenching mechanism. In addition, disparate double-response signals coming from different principles of transduction are in a position to verify each other to improve the accuracy. Hence, examination areas of 0.001-100 nM with E2 for ECL and EC were obtained, supplying a novel sensing strategy with promising ideas and perspectives of detection platform construction.
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http://dx.doi.org/10.1021/acs.analchem.0c04563DOI Listing
April 2021

The combination of G-CSF and AMD3100 mobilizes bone marrow-derived stem cells to protect against cisplatin-induced acute kidney injury in mice.

Stem Cell Res Ther 2021 03 24;12(1):209. Epub 2021 Mar 24.

Tongji Shanxi Hospital, Tongji Medical College, Huazhong University of Science and Technology, Taiyuan, 030032, China.

Background: Several studies have confirmed that mobilizing bone marrow-derived stem cells (BMSCs) ameliorates renal function loss following cisplatin-induced acute kidney injury (AKI). The aim of this study was to explore whether the combination of granulocyte-colony stimulating factor (G-CSF) and plerixafor (AMD3100) exerts beneficial effects on renal function recovery in a model of cisplatin-induced nephrotoxicity.

Methods: C57BL/6J mice received intraperitoneal injections of G-CSF (200 μg/kg/day) for 5 consecutive days. On the day of the last injection, the mice received a single subcutaneous dose of AMD3100 (5 mg/kg) 1 h before cisplatin 20 mg/kg injection. Ninety-six hours after cisplatin injection, the mice were euthanized, and blood and tissue samples were collected to assess renal function and tissue damage. Cell mobilization was assessed by flow cytometry (FCM).

Results: Mice pretreated with G-CSF/AMD3100 exhibited longer survival and lower serum creatinine and blood urea nitrogen (BUN) levels than mice treated with only G-CSF or saline. Combinatorial G-CSF/AMD3100 treatment attenuated tissue injury and cell death, enhanced cell regeneration, and mobilized a higher number of stem cells in the peripheral blood than G-CSF or saline treatment. Furthermore, the mRNA expression of proinflammatory factors was lower, whereas that of anti-inflammatory factors was higher, in the G-CSF/AMD3100 group than in the G-CSF or saline group (all P < 0.05).

Conclusions: These results suggest that combinatorial G-CSF/AMD3100 therapy mobilizes BMSCs to accelerate improvements in renal functions and prevent cisplatin-induced renal tubular injury. This combinatorial therapy may represent a new therapeutic option for the treatment of AKI and should be further investigated in the future.
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http://dx.doi.org/10.1186/s13287-021-02268-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7992860PMC
March 2021

A robotic chewing simulator supplying six-axis mandibular motion, high occlusal force, and a saliva environment for denture tests.

Proc Inst Mech Eng H 2021 Jul 24;235(7):751-761. Epub 2021 Mar 24.

College of Stomatology, Dalian Medical University, Dalian, China.

Six-axis motion is essential for the evaluation of the wear failure modes of dental prostheses with complete teeth morphologies, and a high occlusal force capacity is vital for static clenching and dynamic bruxism. Additionally, the saliva environment influences abrasive particles and crack growth. The present research was aimed at the development of a six-axis masticatory and saliva simulator with these capacities. The masticatory simulator was designed based on a six-axis parallel mechanism, and the saliva simulator consisted of a saliva circuit and a temperature control loop. A control system of the masticatory and saliva simulators was constructed. The operating interface includes a centric occlusal position search, a static test, a dynamic test, a saliva supply, and data reporting. The motion and force performances of the masticatory simulator were evaluated. The flow rate and temperature change of the saliva simulator were calculated. For the occlusal position-searching, the driving amplitude is linear with the moving variables during minor one-axis motion. For the static tests, the force capacity of the driving chain is 3540 N, while for the dynamic tests, the force capacity is 1390 N. The flow rate of the saliva is 0.18-51.84 mL/min, and the saliva can effectively wet the prosthesis without the risk of overflow. Moreover, the saliva temperature can increase from room temperature (23°C) to body temperature (37°C) in about 6 min. The proposed DUT-2 simulator with six-axis motion, high force, and a salvia environment provides an in vitro testing approach to validate numerical simulation results and explain the clinical failure modes of prostheses. The centric occlusal position-searching, static tests, and dynamic tests could therefore be executed using a single testing machine. Moreover, the proposed device is more compact than previously reported six-axis masticatory simulators, including the Bristol simulator and DUT-1 simulator.
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http://dx.doi.org/10.1177/09544119211005601DOI Listing
July 2021

Plasmonically Calibrated Label-Free Surface-Enhanced Raman Spectroscopy for Improved Multivariate Analysis of Living Cells in Cancer Subtyping and Drug Testing.

Anal Chem 2021 03 5;93(10):4601-4610. Epub 2021 Mar 5.

Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, Virginia 24061, United States.

Plasmonic nanostructure-enabled label-free surface-enhanced Raman spectroscopy (SERS) emerges as a rapid nondestructive molecular fingerprint characterization technique for complex biological samples. However, label-free SERS bioanalysis faces challenges in reliability and reproducibility due to SERS signals' high susceptibility to local optical field variations at plasmonic hotspots, which can bias correlations between the measured spectroscopic features and the actual molecular concentration profiles of complex biochemical matrices. Herein, we report that plasmonically enhanced electronic Raman scattering (ERS) signals from metal nanostructures can serve as a SERS calibration internal standard to improve multivariate analysis of living biological systems. Through side-by-side comparisons with noncalibrated SERS datasets, we demonstrate that the ERS-based SERS calibration can enhance supervised learning classification of label-free living cell SERS spectra in (1) subtyping breast cancer cells with different degrees of malignancy and (2) assessing cancer cells' drug responses at different dosages. Notably, the ERS-based SERS calibration has the advantages of excellent photostability under laser excitation, no spectral interference with biomolecule Raman signatures, and no occupation competition with biomolecules at hotspots. Therefore, we envision that the ERS-based SERS calibration can significantly boost the multivariate analysis performance in label-free SERS measurements of living biological systems and other complex biochemical matrices.
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http://dx.doi.org/10.1021/acs.analchem.0c05206DOI Listing
March 2021

Static analysis with a realistic loading condition on all-ceramic crown prosthesis during chewing.

Int J Prosthodont 2021 Feb 12. Epub 2021 Feb 12.

Purpose: To evaluate the stress distribution during chewing in a realistic loading condition on a prosthesis (single-tooth crown) using a static analysis.

Materials And Methods: An all-ceramic crown in the mandibular first molar was selected as the representative prosthesis. First, three contact states (intrusive state, transition state, and extrusive state) were selected from the parametric chewing trajectory. Then, the distances between the antagonistic molars and the normal vectors of the mandibular first molar were calculated by using an automated contact analysis routine (independently developed). Next, normal and tangential forces were defined based on the contact information and the food property. Finally, the static analysis was executed by applying the force and the fixed boundary condition.

Results: The distribution of the occlusal force was nonuniform in the static analysis. Compared to concentrated and uniform loading conditions, the stress distribution of the prosthesis under the nonuniform loading condition revealed new characteristics.

Conclusion: The generation procedure of the static analysis, based on fundamental contact analysis, was evidence-based. The static analysis with the nonuniform loading condition was more recommended than the other two conditions.
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http://dx.doi.org/10.11607/ijp.6287DOI Listing
February 2021

High chemokine ligand 11 levels in nasal lavage fluid: A potential predictor of and therapeutic target for murine eosinophilic chronic rhinosinusitis.

Life Sci 2021 Apr 13;271:119218. Epub 2021 Feb 13.

Department of Otorhinolaryngology, Head and Neck Surgery Xuanwu Hospital, Capital Medical University, Beijing, China. Electronic address:

Aim: We aimed to discover whether group 2 innate lymphoid cells (ILC2s) and cytokines in nasal lavage fluid could be used to predict eosinophilic infiltration in mice with eosinophilic chronic rhinosinusitis (ECRS).

Methods: Ten mice were divided into two groups. The ECRS group received an intranasal challenge of Aspergillus oryzae protease (AP) and ovalbumin (OVA) to establish disease. A control group received intranasal phosphate-buffered saline. Histopathology of nasal cavities and paranasal sinuses, and cytokine and ILC2s levels in nasal lavage fluid were analyzed and compared between the ECRS and control mouse groups.

Key Findings: ILC2s numbers were not significantly higher in the nasal lavage fluid of the ECRS group mice compared with those of the control group. Eotaxin/chemokine (CC motif) ligand 11 (CCL11) levels were significantly higher in the nasal lavage fluid of mice in the ECRS group compared with those in the control group. However, no statistical differences were seen in the classic proinflammatory cytokines, IL-33, IL-25, and thymic stromal thymopoietin (TSLP), or the classic type 2 cytokines, IL-4, IL-5, and IL-13 between groups.

Significance: Eotaxin/CCL11 levels in nasal lavage fluid rather than that of ILC2s and classic proinflammatory and type 2 cytokines were significantly higher in ECRS mice compared with control ones. Eotaxin/CCL11 showed diagnostic and therapeutic value; however, more studies are needed to test and verify its value.
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http://dx.doi.org/10.1016/j.lfs.2021.119218DOI Listing
April 2021

Liposome encapsulated electron donor strategy for signal-on CYFRA 21-1 photoelectrochemical analysis.

Mikrochim Acta 2021 Feb 9;188(3):75. Epub 2021 Feb 9.

Collaborative Innovation Center for Green Chemical Manufacturing and Accurate Detection, Key Laboratory of Interfacial Reaction & Sensing Analysis in Universities of Shandong, University of Jinan, Jinan, 250022, Shandong, China.

A novel electron donor controlled-release system is proposed based on liposome encapsulated L-cysteine for the sensitive determination of cytokeratin 19 fragment 21-1 (CYFRA 21-1). On the one hand, a defective TiO modified with methylene blue was employed as a photoactive platform which exhibited a high photoelectrochemical (PEC) response owing to the introduction of oxygen vacancies and the high  photosensitivity of the dye. On the other hand, L-cysteine as the sacrificial electron donor was encapsulated in the vesicles of liposomes, and this composite was used as the signal amplification factor, which is labeled on the secondary antibody of CYFRA 21-1 to further improve the photocurrent sensitivity. The excellent electron transfer path in photoactive materials coupled with the skilful electron donor controlled-release system, contributed to the sensitive  PEC analysis of CYFRA 21-1 underoptimum conditions. The PEC immunoassay showed a linear current response in the range 0.0001-100 ng/mL with a detection limitof 37 fg/mL. Enhanced stability and satisfactory reproducibility were also achieved. The proposed concept  provides a novel signal-on strategy for the sensitive detection of other cancer markers in the electrochemical sensing field.
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http://dx.doi.org/10.1007/s00604-021-04721-4DOI Listing
February 2021

Interaction Between Mesenchymal Stem Cells and Retinal Degenerative Microenvironment.

Front Neurosci 2020 21;14:617377. Epub 2021 Jan 21.

The Research Laboratory of Ophthalmology and Vision Sciences, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China.

Retinal degenerative diseases (RDDs) are a group of diseases contributing to irreversible vision loss with yet limited therapies. Stem cell-based therapy is a promising novel therapeutic approach in RDD treatment. Mesenchymal stromal/stem cells (MSCs) have emerged as a leading cell source due to their neurotrophic and immunomodulatory capabilities, limited ethical concerns, and low risk of tumor formation. Several pre-clinical studies have shown that MSCs have the potential to delay retinal degeneration, and recent clinical trials have demonstrated promising safety profiles for the application of MSCs in retinal disease. However, some of the clinical-stage MSC therapies have been unable to meet primary efficacy end points, and severe side effects were reported in some retinal "stem cell" clinics. In this review, we provide an update of the interaction between MSCs and the RDD microenvironment and discuss how to balance the therapeutic potential and safety concerns of MSCs' ocular application.
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http://dx.doi.org/10.3389/fnins.2020.617377DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7859517PMC
January 2021

Design of realistic chewing trajectory for dynamic analysis of the dental prosthesis.

Acta Bioeng Biomech 2020 ;22(3):77-84

School of Mechanical Engineering, Southeast University, Nanjing, China.

Purpose: The chewing trajectory in the dynamic analysis of dental prosthesis is always defined as a two-segmental straight polyline without enough consideration about chewing force and motion laws. The study was aimed to design a realistic human chewing trajectory for the dynamic analysis based on force and motion planning methods.

Methods: The all-ceramic crown restored in the mandibular first molar was selected as the representative prosthesis. Firstly, a dynamic model containing two molar components and one flat food component was built, and an approximate chewing plane was predefined. According to the desired forces (25 N, 150 N and 25 N), three force planning points were calculated by using tentative trajectories. The motion planning was then executed based on four-segment cubic spline model. Finally, the new trajectory was re-imported into the dynamic model as the displacement load for evaluating its stress influence.

Results: The maximum lateral velocity was 26.81 mm/s. Besides, the forces in the three force planning points were 14.11 N, 126.75 N and 13.56 N. The overall repetition rate of chewing force was 77.21%. The force and stress profiles were similar to the sine curve on the whole. The maximum dynamic stress of the crown prosthesis was 398.5 MPa.

Conclusions: The motion law was effectively brought into the chewing trajectory to introduce the dynamic effect. The global force performance was acceptable, and the force profile was more realistic than the traditional chewing trajectory. The additional reliable characteristic feature of the stress distribution of the dental prosthesis was observed.
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January 2020

Dual-Signaling Electrochemical Ratiometric Method for Competitive Immunoassay of CYFRA21-1 Based on Urchin-like [email protected] and NiSiO(OH)-Au Absorbed Methylene Blue Nanotubes.

ACS Appl Mater Interfaces 2021 Feb 22;13(4):5795-5802. Epub 2021 Jan 22.

Collaborative Innovation Center for Green Chemical Manufacturing and Accurate Detection, Key Laboratory of Interfacial Reaction & Sensing Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, Shandong, China.

A novel ratiometric electrochemical (EC) sensing platform was established for sensitive immunoassay of target cytokeratin 19 fragment 21-1 (CYFRA21-1) biomarker by combining competitive immunoreaction and multisignal output. This immunosensor utilized Ag nanoparticles (NPs)-functionalized urchin-like [email protected] ([email protected]) as a matrix to immobilize CYFRA21-1 antigens and methylene blue (MB)-absorbed NiSiO(OH)-Au nanotubes (NTs) to label the anti-CYFRA21-1 (Ab). During the competitive immunoreaction, square wave voltammetric (SWV) current changes of Ag NPs from [email protected] indicator and MB from NiSiO(OH)-Au/MB indicator are relevant to the dosage of CYFRA21-1-acquired NiSiO(OH)-Au/MB/Ab. More importantly, numerous CYFRA21-1 loaded stably on [email protected] exhibited strong competitive capacity toward the target-CYFRA21-1 to combine NiSiO(OH)-Au/MB/Ab, causing sensitive changes in the ratio of two measured SWV currents. Prominently, "Δ = Δ + |Δ|" (Δ and |Δ| represents the change values of the oxidation peak currents of MB and Ag NPs, respectively) could be regarded as significantly amplifying the signal response and ultimately improving the sensitivity of CYFRA21-1 detection, from which we derived a wide dynamic range from 500 fg/mL to 50 ng/mL and a low detection limit of 0.39 pg/mL (S/N = 3). This work may exert a profound impact on monitoring other biomarkers in early diagnosis of diseases.
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http://dx.doi.org/10.1021/acsami.0c20049DOI Listing
February 2021

Expression of fibroblast growth factor 9 and its receptors in the dentate gyrus of hippocampus in poststroke depression rats.

Neuroreport 2021 03;32(4):321-325

Department of Neurology, Guangdong Sanjiu Brain Hospital, Guangzhou, Guangdong Province, People's Republic of China.

Studies have found that fibroblast growth factor 9 (FGF9) might have a negative effect in the psychiatric diseases, such as depression or anxiety, but its potential role in the pathophysiology of poststroke depression (PSD) remains uncertain. Here, we set out to investigate the expression changes of FGF9 and its receptors in PSD rats. Middle cerebral artery occlusion (MCAO) combined with chronic unpredictable mild stress was used to establish the PSD rat model. Then, the rats were randomly divided into four groups: control (sham-operation), MCAO, PSD and treated (fluoxetine injection by intraperitoneal). Weight measurement, sucrose preference test, open-field test and forced swim test were performed to evaluate the behavioral changes, and then Western blot and real-time quantitative PCR were used to detect the expression level of FGF9, fibroblast growth factor receptor 1 (FGFR1) and receptor 3 (FGFR3) in the dentate gyrus of rat hippocampus. We found that FGF9 protein and mRNA expression increased significantly in the MCAO and PSD groups; FGFR3 protein and mRNA expression decreased significantly in the MCAO and PSD groups; FGFR1 protein and mRNA expression decreased significantly in the PSD group, but increased in the treated group. Furthermore, the changes mentioned above were reversed obviously by fluoxetine. These results indicated that upregulated FGF9 expression and downregulated FGFR1 and FGFR3 expression may be involved in the pathogenesis of PSD, and the FGF9/FGFR signaling pathway may be considered as an attractive target for further study.
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http://dx.doi.org/10.1097/WNR.0000000000001591DOI Listing
March 2021

Effects of atorvastatin in combination with celecoxib and tipifarnib on proliferation and apoptosis in pancreatic cancer sphere-forming cells.

Eur J Pharmacol 2021 Feb 24;893:173840. Epub 2020 Dec 24.

Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, NJ, 08854, USA; Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, 08903, USA. Electronic address:

Cancer stem cell (CSC) plays an important role in pancreatic cancer pathogenesis and treatment failure. CSCs are characterized by their ability to form tumor spheres in serum-free medium and expression of CSC related markers. In the present study, we investigated the effect atorvastatin, celecoxib and tipifarnib in combination on proliferation and apoptosis in Panc-1 sphere-forming cells. The sphere-forming cells were isolated from Panc-1 cells by sphere-forming method. These sphere-forming cells showed CSC properties. The levels of CD44, CD133 and ALDH1A1 in the sphere-forming cells were increased. Moreover, Panc-1 sphere-forming cells were resistant to chemotherapeutic drug gemcitabine. Combined atorvastatin with celecoxib and tipifarnib synergistically decreased the sphere forming ability of Panc-1 cells and the drug combination also strongly inhibited cell proliferation and promoted apoptosis in the sphere-forming cells. The effects of the drug combination on the Panc-1 sphere-forming cells were associated with decreases in the levels of CD44, CD133 and ALDH1A1, and suppression of Akt and NF-κB activation. Results of the present study indicate that the combination of atorvastatin, celecoxib and tipifarnib may represent an effective approach for inhibiting pancreatic CSCs.
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http://dx.doi.org/10.1016/j.ejphar.2020.173840DOI Listing
February 2021

Electrically conductive 3D printed TiCT MXene-PEG composite constructs for cardiac tissue engineering.

Acta Biomater 2020 Dec 19. Epub 2020 Dec 19.

Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, IN 46556, United States; Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN 46556, United States. Electronic address:

Tissue engineered cardiac patches have great potential as a therapeutic treatment for myocardial infarction (MI). However, for successful integration with the native tissue and proper function of the cells comprising the patch, it is crucial for these patches to mimic the ordered structure of the native extracellular matrix and the electroconductivity of the human heart. In this study, a new composite construct that can provide both conductive and topographical cues for human induced pluripotent stem cell derived cardiomyocytes (iCMs) is developed for cardiac tissue engineering applications. The constructs are fabricated by 3D printing conductive titanium carbide (TiCT) MXene in pre-designed patterns on polyethylene glycol (PEG) hydrogels, using aerosol jet printing, at a cell-level resolution and then seeded with iCMs and cultured for one week with no signs of cytotoxicity. The results presented in this work illustrate the vital role of 3D-printed TiCT MXene on aligning iCMs with a significant increase in MYH7, SERCA2, and TNNT2 expressions, and with an improved synchronous beating as well as conduction velocity. This study demonstrates that 3D printed TiCT MXene can potentially be used to create physiologically relevant cardiac patches for the treatment of MI.
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http://dx.doi.org/10.1016/j.actbio.2020.12.033DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8213874PMC
December 2020

A microfluidic cathodic photoelectrochemical biosensor chip for the targeted detection of cytokeratin 19 fragments 21-1.

Lab Chip 2021 01 14;21(2):378-384. Epub 2020 Dec 14.

Collaborative Innovation Center for Green Chemical Manufacturing and Accurate Detection, Key Laboratory of Interfacial Reaction & Sensing Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.

A microfluidic chip integrated with a microelectrode and a cathodic photoelectrochemical (PEC) biosensor for the ultrasensitive detection of non-small cell lung cancer cytokeratin fragments based on a signal amplification strategy was designed. The mechanism for signal amplification is developed based on the p-n junction of AgI/BiGaO, with dissolved O as an electron acceptor to produce the superoxide anion radical (˙O) as the working microelectrode. By combining this with a novel superoxide-dismutase-loaded honeycomb manganese oxide nanostructure ([email protected]) as the co-catalyst signal amplification label, ˙O can be catalyzed by SOD via a disproportionation reaction to produce O and HO; then, hMnO is able to trigger the decomposition of HO to generate O and HO. Therefore, the increased O promotes the separation of electron-hole pairs via consuming more electrons, leading to an effective enhancement of the cathodic PEC behavior. Under optimum conditions, with the cytokeratin 19 fragments 21-1 (CYFRA 21-1) as the targeted detection objects, the microfluidic cathodic PEC biosensor chip exhibited excellent linearity from 0.1 pg mL to 100 ng mL, with a detection limit of 0.026 pg mL (S/N = 3). The exciting thing that this work offers is a new strategy for the detection of other important cancer biomarkers for disease diagnosis and prognosis.
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http://dx.doi.org/10.1039/d0lc01063dDOI Listing
January 2021

Applications of direct analysis in real time mass spectrometry in food analysis: A review.

Rapid Commun Mass Spectrom 2021 Mar;35(6):e9013

Jiangxi Key Laboratory for Mass Spectrometry and Instrumentation, East China University of Technology, Nanchang, China.

Rationale: Direct analysis in real time (DART) combined with mass spectrometry (MS) detection has become one of the most broadly used analytical approaches for the direct molecular characterization of food samples with regard to their chemical quality, safety, origin, and authentication. The major advantages of DART-MS for food analysis include high chemical sensitivity and specificity, high speed and throughput of analysis, simplicity, and the obviation of tedious sample preparation and solvents.

Methods: The recent applications of DART coupled with different mass analyzers, including quadrupole, ion trap, Orbitrap, and time of flight, are discussed. In addition, sample pretreatment methods that have been coupled with DART-MS are discussed.

Results: We summarize the applications of DART-MS in food science and industry published in the period from 2005 to this date. The applications and analytical characteristics are systematically categorized across the three major types of foods: solid foods, liquid foods, and viscous foods.

Conclusions: DART-MS has proved its high suitability for the direct, rapid, and high-throughput molecular analysis of very different food samples with minimal or no sample preparation, thus offering a high-speed alternative to liquid chromatography/mass spectrometry (LC/MS) and gas chromatography/mass spectrometry (GC/MS) approaches that are traditionally employed in food analysis.
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http://dx.doi.org/10.1002/rcm.9013DOI Listing
March 2021