Publications by authors named "Zhongwei Chen"

192 Publications

Engineering Oversaturated Fe-N5 Multi-functional Catalytic Sites for Durable Lithium-Sulfur Batteries.

Angew Chem Int Ed Engl 2021 Aug 31. Epub 2021 Aug 31.

University of Waterloo, Department of Chemical Engineering, 200 University Avenue West, N2L3G1, Waterloo, CANADA.

Lithium-sulfur (Li-S) batteries have been strongly regarded as a promising next-generation system for advanced energy storage owing to high theoretical energy density of 2600 Wh kg-1. However, the practical implementation of Li-S batteries has still been thwarted by the detrimental shuttling behavior of polysulfides, and the sluggish kinetics in electrochemical processes. Herein, a novel single atom (SA) catalyst with oversaturated Fe-N5 coordination structure (Fe-N5-C) is precisely synthesized by the absorption-pyrolysis strategy and introduced to effective sulfur host material. The experimental characterizations and theoretical calculations reveal synergism between atomically dispersed Fe-N5 active sites and the unique carbon support. The results exhibit that the sulfur composite cathode built on the Fe-N5-C can not only adsorb polysulfides via chemical interaction, but also boost the redox reaction kinetics, thus mitigating the shuttle effect. Meanwhile, the robust three-dimensional nitrogen doped carbon nanofiber with large surface area, and high porosity enables strong physical confinement and fast electron/ion transfer process. Attributed to such unique features, Li-S batteries with S/Fe-N5-C composite cathode realized outstanding cyclability and rate capability, as well as high areal capacities under raised sulfur loading, which demonstrates great potential in developing advanced Li-S batteries.
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http://dx.doi.org/10.1002/anie.202108882DOI Listing
August 2021

Investigation on the Exit Burr Formation in Micro Milling.

Micromachines (Basel) 2021 Aug 12;12(8). Epub 2021 Aug 12.

Xiamen Xiazhi Technology Tool Co., Ltd., Xiamen 361115, China.

The burr on micro part has harmful effect on the dimensional accuracy and service performance. The original control of exit burr formation during micro milling is desirable and advisable. In this paper, the formation mechanism of exit burr was studied based on the varying cutting direction during micro milling. Three exit burr control strategies were concluded, the material properties embrittlement, the support stiffness increasing and machining parameter optimizing operations. Then, micro milling experiments were carried out to investigate the exit burr morphology and size. It was found that the exit burr formation was attributed to the change of material flowing path at the exit surface, which was caused by the negative shear deformation zone that was induced by the discontinuous shape features. Different exit burr morphologies were classified; the triangle exit burr type was caused by the varying exit burr growing direction along the exit surface. The optimal machining parameters in micro milling to obtain a small exit burr were suggested.
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http://dx.doi.org/10.3390/mi12080952DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8401231PMC
August 2021

Genetic Characteristics and Pathogenicity of a Novel Porcine Deltacoronavirus Southeast Asia-Like Strain Found in China.

Front Vet Sci 2021 16;8:701612. Epub 2021 Jul 16.

College of Animal Science and Technology, Guangxi University, Nanning, China.

Farmers involved in the lucrative pork trading business between China and Southeast Asian countries should be aware of a recently discovered novel porcine deltacoronavirus (PDCoV) in Guangxi province, China. A PDCoV strain, CHN/GX/1468B/2017, was isolated from the small intestinal contents of piglets with diarrhea from this region, with a titer of 1 × 10 TCID/mL on LLC-PK cells. The full-length genome sequence consists of 25,399 nt as determined by next-generation sequencing and this was deposited in the GenBank (accession number MN025260.1). Genomic analysis showed that CHN/GX/1468B/2017 strain had 96.9~99.4% nucleotide homology with other 87 referenced PDCoV strains from different areas, and contained 6 and 9-nt deletions at positions 1,733~1,738 and 2,804~2,812, respectively, in the ORF1a gene. Phylogenetic analyses based on the whole gene sequence as well as S protein and ORF1a/1b protein sequences all showed that this strain was closely related to the Southeast Asia strain. When 7-day-old piglets were inoculated orally with the CHN/GX/1468B/2017 strain, they developed severe diarrhea, with a peak of fecal viral shedding at 4 days post-infection. Although no death or fever were observed, the CHN/GX/1468B/2017 strain produced a wide range of tissue tropism, with the main target being the intestine. Importantly, the VH:CD ratios of the jejunum and ileum in infected piglets were significantly lower than controls. These results indicate that CHN/GX/1468B/2017, isolated in China, is a novel PDCoV Southeast Asia-like strain with distinct genetic characteristics and pathogenicity. This finding enriches the international information on the genetic diversity of PDCoV.
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http://dx.doi.org/10.3389/fvets.2021.701612DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8322666PMC
July 2021

Electrolyte Design for Lithium Metal Anode-Based Batteries Toward Extreme Temperature Application.

Adv Sci (Weinh) 2021 Jul 17:e2101051. Epub 2021 Jul 17.

Department of Chemical Engineering, Waterloo Institute of Nanotechnology, University of Waterloo, Waterloo, N2L 3G1, Canada.

Lithium anode-based batteries (LBs) are highly demanded in society owing to the high theoretical capacity and low reduction potential of metallic lithium. They are expected to see increasing deployment in performance critical areas including electric vehicles, grid storage, space, and sea vehicle operations. Unfortunately, competitive performance cannot be achieved when LBs operating under extreme temperature conditions where the lithium-ion chemistry fail to perform optimally. In this review, a brief overview of the challenges in developing LBs for low temperature (<0 °C) and high temperature (>60 °C) operation are provided followed by electrolyte design strategies involving Li salt modification, solvation structure optimization, additive introduction, and solid-state electrolyte utilization for LBs are introduced. Specifically, the prospects of using lithium metal batteries (LMBs), lithium sulfur (Li-S) batteries, and lithium oxygen (Li-O ) batteries for performance under low and high temperature applications are evaluated. These three chemistries are presented as prototypical examples of how the conventional low temperature charge transfer resistances and high temperature side reactions can be overcome. This review also points out the research direction of extreme temperature electrolyte design toward practical applications.
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http://dx.doi.org/10.1002/advs.202101051DOI Listing
July 2021

Exploring the Rescue Strategy for Cardiac Arrest in Makeshift (FangCang) Hospital Workers during the Pneumonia Outbreak Associated with COVID-19.

Iran J Public Health 2020 Oct;49(Suppl 1):76-81

Key Laboratory of Fertility Preservation and Maintenance of Ministry of Education, Ningxia Medical University, Yinchuan 750004, China.

Background: Beginning in Dec 2019, a novel coronavirus, designated SARS-CoV-2, has caused an international outbreak of respiratory illness termed COVID-19. The workers in the FangCang hospital have to work for more than 8 h and the work is high strength. Furthermore, to protect health and prevent serious cross-infection, they need to wear isolation equipment when working in FangCang hospital. These characteristics increase the risk of cardiac arrest (CA), which seriously endangers the lives of workers.

Methods: We participated in the rescue of the patient and workers at first-line in FangCang hospital, and summarized the rescue strategies for workers rescuing.

Results: Workers with CA were rescued in time according our guideline and showed zero dead in FangCang hospital.

Conclusion: This study establishes the strategy for the CA of workers including the establishment of an in-FangCang resuscitation team, the establishment of a dedicated rescue room, and the formulation of rescue measures and procedures for CA of workers in the FangCang hospital. Therefore, we aimed to provide a strategy for the rescue of workers with CA in the FangCang hospital and share the success in rescuing with the world.
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http://dx.doi.org/10.18502/ijph.v49iS1.3672DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8266017PMC
October 2020

Reduction of N to NH by TiO-supported Ni cluster catalysts: a DFT study.

Phys Chem Chem Phys 2021 Aug;23(31):16707-16717

Key Laboratory of Functional Materials Physics and Chemistry of the Ministry of Education, College of Physics, Jilin Normal University, Siping 136000, China.

Electrochemical techniques for ammonia synthesis are considered as an encouraging energy conversion technology to efficiently meet the challenge of nitrogen cycle balance. Herein, we find that TiO2(101)-supported Ni4 and Ni13 clusters can serve as efficient catalysts for electrocatalytic N2 reduction based on theoretical calculations. Electronic property calculations reveal the formation of electron-deficient Ni clusters on the TiO2 surface, which provides multiple active sites for N2 adsorption and activation. Theoretical calculation identifies the strongest activated configuration of N2* on the catalysts and confirms the potential-limiting step in the nitrogen reduction reaction (NRR). On Ni4-TiO2(101), N2* → NNH* is the potential-limiting step with a very small free energy increase (ΔG) of 0.24 eV (the corresponding overpotential is 0.33 V), while on Ni13-TiO2(101) the potential-limiting step occurs at NH* → NH2* with ΔG of 0.49 eV (the corresponding overpotential is 0.58 V). Moreover, the Nin-TiO2(101) catalyst, especially Ni13-TiO2(101), involves in a highly selective NRR even at the corresponding NRR overpotential. This work will enlighten material design to construct metal oxide supported transition metal clusters for the highly efficient NRR and NH3 synthesis.
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http://dx.doi.org/10.1039/d1cp00859eDOI Listing
August 2021

Characteristics of 1738 Patients With Coronavirus Disease 2019 (COVID-19) in Wuhan, China.

Disaster Med Public Health Prep 2021 Apr 30:1-5. Epub 2021 Apr 30.

Department of Emergency, General Hospital of Ningxia Medical University, Yinchuan, China.

Objective: Since December 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been discovered in Wuhan and spread rapidly across China and worldwide. Characteristics of infected patients are needed to get insight into the full spectrum of the disease.

Methods: Epidemiological and clinical information of 1738 diagnosed patients during February 7-26, 2020 in Wuhan Dongxihu Fangcang Hospital were analyzed. A total of 709 patients were followed up on symptom, mental health, isolation site, and medication after discharge.

Results: There were 852 males and 886 females in the cohort. The average age of the patients was 48.8 y. A total of 79.98% of the patients were from Wuhan, Hubei Province. The most common initial symptoms were fever, cough, and shortness of breath. Among all the patients, 1463 had complications, with respiratory distress as the most common complication. The average duration of hospitalization was 15.95 ± 14.69 d. The most common postdischarge symptom is cough. After discharge, most patients were full of energy and chose hotel as their self-isolation site. Coronavirus disease 2019 (COVID-19) Chinese medicine No.2 prescription is the medication used most commonly by the patients after discharge.

Conclusions: The population is generally susceptible to SARS-CoV-2. After receiving aggressive treatment of combined Chinese and Western medicine, most patients had a good prognosis and mental health after discharge.
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http://dx.doi.org/10.1017/dmp.2021.129DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8193190PMC
April 2021

Hierarchical Micro-Nanoclusters of Bimetallic Layered Hydroxide Polyhedrons as Advanced Sulfur Reservoir for High-Performance Lithium-Sulfur Batteries.

Adv Sci (Weinh) 2021 Apr 29;8(7):2003400. Epub 2021 Jan 29.

Department of Chemical Engineering University of Waterloo Waterloo ON N2L 3G1 Canada.

Rational construction of sulfur electrodes is essential in pursuit of practically viable lithium-sulfur (Li-S) batteries. Herein, bimetallic NiCo-layered double hydroxide (NiCo-LDH) with a unique hierarchical micro-nano architecture is developed as an advanced sulfur reservoir for Li-S batteries. Compared with the monometallic Co-layered double hydroxide (Co-LDH) counterpart, the bimetallic configuration realizes much enriched, miniaturized, and vertically aligned LDH nanosheets assembled in hollow polyhedral nanoarchitecture, which geometrically benefits the interface exposure for host-guest interactions. Beyond that, the introduction of secondary metal intensifies the chemical interactions between layered double hydroxide (LDH) and sulfur species, which implements strong sulfur immobilization and catalyzation for rapid and durable sulfur electrochemistry. Furthermore, the favorable NiCo-LDH is architecturally upgraded into closely packed micro-nano clusters with facilitated long-range electron/ion conduction and robust structural integrity. Due to these attributes, the corresponding Li-S cells realize excellent cyclability over 800 cycles with a minimum capacity fading of 0.04% per cycle and good rate capability up to 2 C. Moreover, highly reversible areal capacity of 4.3 mAh cm can be achieved under a raised sulfur loading of 5.5 mg cm. This work provides not only an effective architectural design but also a deepened understanding on bimetallic LDH sulfur reservoir for high-performance Li-S batteries.
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http://dx.doi.org/10.1002/advs.202003400DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8025003PMC
April 2021

"Two Ships in a Bottle" Design for Zn-Ag-O Catalyst Enabling Selective and Long-Lasting CO Electroreduction.

J Am Chem Soc 2021 May 14;143(18):6855-6864. Epub 2021 Apr 14.

Department of Chemical Engineering, Waterloo Institute for Nanotechnology, Waterloo Institute for Sustainable Energy, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.

Electrochemical CO reduction (CORR) using renewable energy sources represents a sustainable means of producing carbon-neutral fuels. Unfortunately, low energy efficiency, poor product selectivity, and rapid deactivation are among the most intractable challenges of CORR electrocatalysts. Here, we strategically propose a "two ships in a bottle" design for ternary Zn-Ag-O catalysts, where ZnO and Ag phases are twinned to constitute an individual ultrafine nanoparticle impregnated inside nanopores of an ultrahigh-surface-area carbon matrix. Bimetallic electron configurations are modulated by constructing a Zn-Ag-O interface, where the electron density reconfiguration arising from electron delocalization enhances the stabilization of the *COOH intermediate favorable for CO production, while promoting CO selectivity and suppressing HCOOH generation by altering the rate-limiting step toward a high thermodynamic barrier for forming HCOO*. Moreover, the pore-constriction mechanism restricts the bimetallic particles to nanosized dimensions with abundant Zn-Ag-O heterointerfaces and exposed active sites, meanwhile prohibiting detachment and agglomeration of nanoparticles during CORR for enhanced stability. The designed catalysts realize 60.9% energy efficiency and 94.1 ± 4.0% Faradaic efficiency toward CO, together with a remarkable stability over 6 days. Beyond providing a high-performance CORR electrocatalyst, this work presents a promising catalyst-design strategy for efficient energy conversion.
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http://dx.doi.org/10.1021/jacs.0c12418DOI Listing
May 2021

Radiomics Model for Evaluating the Level of Tumor-Infiltrating Lymphocytes in Breast Cancer Based on Dynamic Contrast-Enhanced MRI.

Clin Breast Cancer 2020 Dec 28. Epub 2020 Dec 28.

Department of Radiology, The First Affiliate Hospital of Wenzhou Medical University, Wenzhou, China. Electronic address:

Background: To help identify potential breast cancer (BC) candidates for immunotherapies, we aimed to develop and validate a radiology-based biomarker (radiomic score) to predict the level of tumor-infiltrating lymphocytes (TILs) in patients with BC.

Patients And Methods: This retrospective study enrolled 172 patients with histopathology-confirmed BC assigned to the training (n = 121) or testing (n = 51) cohorts. Radiomic features were extracted and selected using Analysis-Kit software. The correlation between TIL levels and clinical features and radiomic features was evaluated. The clinical features model, radiomic signature model, and combined prediction model were constructed and compared. Predictive performance was assessed by receiver operating characteristic analysis and clinical utility by implementing a nomogram.

Results: Seven radiomic features were selected as the best discriminators to construct the radiomic signature model, the performance of which was good in both the training and validation data sets, with an area under the curve (AUC) of 0.742 (95% confidence interval [CI], 0.642-0.843) and 0.718 (95% CI, 0.558-0.878), respectively. Estrogen receptor status and tumor diameter were confirmed to be significant features for building the clinical feature model, which had an AUC of 0.739 (95% CI, 0.632-0.846) and 0.824 (95% CI, 0.692-0.957), respectively. The combined prediction model had an AUC of 0.800 (95% CI, 0.709-0.892) and 0.842 (95% CI, 0.730-0.954), respectively.

Conclusion: The radiomic signature could be an important predictor of the TIL level in BC, which, when validated, could be useful in identifying BC patients who can benefit from immunotherapies. The nomogram may help clinicians make decisions.
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http://dx.doi.org/10.1016/j.clbc.2020.12.008DOI Listing
December 2020

Magnetic-Field-Stimulated Efficient Photocatalytic N Fixation over Defective BaTiO Perovskites.

Angew Chem Int Ed Engl 2021 May 9;60(21):11910-11918. Epub 2021 Apr 9.

Department of Chemical Engineering, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada.

Efficient coupling solar energy conversion and N fixation by photocatalysis has been shown promising potentials. However, the unsatisfied yield rate of NH curbs its forward application. Defective typical perovskite, BaTiO , shows remarkable activity under an applied magnetic field for photocatalytic N fixation with an NH yield rate exceeding 1.93 mg L  h . Through steered surface spin states and oxygen vacancies, the electromagnetic synergistic effect between the internal electric field and an external magnetic field is stimulated. X-ray absorption spectroscopy and density functional theory calculations reveal the regulation of electronic and magnetic properties through manipulation of oxygen vacancies and inducement of Lorentz force and spin selectivity effect. The electromagnetic effect suppresses the recombination of photoexcited carriers in semiconducting nanomaterials, which acts synergistically to promote N adsorption and activation while facilitating fast charge separation under UV-vis irradiation.
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http://dx.doi.org/10.1002/anie.202100726DOI Listing
May 2021

Localized Polysulfide Injector for the Activation of Bulk Lithium Sulfide.

J Am Chem Soc 2021 Feb 28;143(5):2185-2189. Epub 2021 Jan 28.

Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 Cass Avenue, Lemont, Illinois 60439, United States.

The activation of commercial LiS remains to be one of the key challenges against its commercialization as a starting cathode material for a sulfur-based Li-ion battery system. In this work we take advantage of the lower oxidation potential of commercial NaS (1-3 wt%) to serve as an and local polysulfide injector for the activation of commercial LiS (70 wt%). In contrast to applying pre-solvated redox mediators, this technique allows for the activation of commercial LiS at lower voltages with an electrolyte content as low as 3 μL mg at 3 mgmg cm and 4 μL mg at 6.5 mg cm without any other material modification.
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http://dx.doi.org/10.1021/jacs.0c11265DOI Listing
February 2021

Effects of different combined regimens of cisplatin, metformin, and quercetin on nasopharyngeal carcinoma cells and subcutaneous xenografts.

Sci Rep 2021 01 13;11(1):1040. Epub 2021 Jan 13.

Xiamen Key Laboratory of Marine Medicinal Natural Products Resources, Xiamen Medical College, Xiamen, 361023, People's Republic of China.

Cisplatin, metformin, and quercetin are all reliable anticancer drugs. However, it is unclear how effective their different combination regimens are on the growth of nasopharyngeal carcinoma cell line Sune-1 and subcutaneous xenograft in nude mice. This study evaluated the effects of single-drug, two-drug, and three-drug simultaneous or sequential combined application of these drugs on the growth of Sune-1 cells and subcutaneous xenograft tumors in nude mice. The results showed that the different combination regimens of cisplatin, metformin and quercetin all had significant inhibitory effects on the proliferation of Sune-1 cells and the growth of subcutaneous xenografts in nude mice (P < 0.01), and the inhibition rate of the three drugs simultaneous combined application was significant Higher than the two-drug combination or single-drug application (P < 0.05), the contribution level of each drug in the three-drug combination application from high to low were cisplatin > metformin > quercetin. In summary, our results indicate that the simultaneous combination of cisplatin, metformin, and quercetin may synergistically inhibit the growth of Sune-1 cells and subcutaneous xenografts in nude mice through their different anticancer mechanisms, which may be clinically refractory and provide reference for chemotherapy of patients with recurrent nasopharyngeal carcinoma.
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http://dx.doi.org/10.1038/s41598-020-80198-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7807075PMC
January 2021

Constructing multifunctional solid electrolyte interface via in-situ polymerization for dendrite-free and low N/P ratio lithium metal batteries.

Nat Commun 2021 Jan 8;12(1):186. Epub 2021 Jan 8.

Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices, School of Information and Optoelectronic Science and Engineering & International Academy of Optoelectronics at Zhaoqing, South China Normal University, Guangdong, 510006, China.

Stable solid electrolyte interface (SEI) is highly sought after for lithium metal batteries (LMB) owing to its efficient electrolyte consumption suppression and Li dendrite growth inhibition. However, current design strategies can hardly endow a multifunctional SEI formation due to the non-uniform, low flexible film formation and limited capability to alter Li nucleation/growth orientation, which results in unconstrained dendrite growth and short cycling stability. Herein, we present a novel strategy to employ electrolyte additives containing catechol and acrylic groups to construct a stable multifunctional SEI by in-situ anionic polymerization. This self-smoothing and robust SEI offers multiple sites for Li adsorption and steric repulsion to constrain nucleation/growth process, leading to homogenized Li nanosphere formation. This isotropic nanosphere offers non-preferred Li growth orientation, rendering uniform Li deposition to achieve a dendrite-free anode. Attributed to these superiorities, a remarkable cycling performance can be obtained, i.e., high current density up to 10 mA cm, ultra-long cycle life over 8500 hrs operation, high cumulative capacity over 4.25 Ah cm and stable cycling under 60 °C. A prolonged lifespan can also be achieved in Li-S and Li-LiFePO cells under lean electrolyte content, low N/P ratio or high temperature conditions. This facile strategy also promotes the practical application of LMB and enlightens the SEI design in related fields.
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http://dx.doi.org/10.1038/s41467-020-20339-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7794354PMC
January 2021

Strain Engineering of a MXene/CNT Hierarchical Porous Hollow Microsphere Electrocatalyst for a High-Efficiency Lithium Polysulfide Conversion Process.

Angew Chem Int Ed Engl 2021 Feb 4;60(5):2371-2378. Epub 2021 Jan 4.

Department of Chemical Engineering, University of Waterloo, Waterloo, ON, N2L 3G1, Canada.

Tensile-strained Mxene/carbon nanotube (CNT) porous microspheres were developed as an electrocatalyst for the lithium polysulfide (LiPS) redox reaction. The internal stress on the surface results in lattice distortion with expanding Ti-Ti bonds, endowing the Mxene nanosheet with abundant active sites and regulating the d-band center of Ti atoms upshifted closer to the Fermi level, leading to strengthened LiPS adsorbability and accelerated catalytic conversion. The macroporous framework offers uniformed sulfur distribution, potent sulfur immobilization, and large surface area. The composite interwoven by CNT tentacle enhances conductivity and prevents the restacking of Mxene sheets. This combination of tensile strain effect and hierarchical architecture design results in smooth and favorable trapping-diffusion-conversion of LiPS on the interface. The Li-S battery exhibits an initial capacity of 1451 mAh g at 0.2 C, rate capability up to 8 C, and prolonged cycle life.
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http://dx.doi.org/10.1002/anie.202011493DOI Listing
February 2021

Highly Stable Low-Cost Electrochemical Gas Sensor with an Alcohol-Tolerant N,S-Codoped Non-Precious Metal Catalyst Air Cathode.

ACS Sens 2021 03 11;6(3):752-763. Epub 2020 Dec 11.

Department of Chemical Engineering, Waterloo Institute for Nanotechnology, Waterloo Institute for Sustainable Energy, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.

The emerging applications of electrochemical gas sensors (EGSs) in Internet of Things-enabled smart city and personal health electronics bring out a new challenge for common EGSs, such as alcohol fuel cell sensors (AFCSs) to reduce the dependence on a pricy Pt catalyst. Here, for the first time, we propose a low-cost novel N,S-codoped metal catalyst (FeNSC) to accelerate oxygen reduction reaction (ORR) and replace the Pt catalyst in the cathode of an AFCS. The optimal FeNSC shows high ORR activity, stability, and alcohol tolerance. Furthermore, the FeNSC-based AFCS not only demonstrates excellent linearity, low detection limit, high stability, and superior sensitivity to that of the commercial Pt/C-based AFCS but also outperforms commercial Pt/C-based AFCS in the exposed cell regarding great linearity, high sensitivity, and great stability. Such a promising sensor performance not just proves the concept of the FeNSC-based ACFS but enlightens the next-generation designs toward low-cost, highly sensitive, and durable EGSs.
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http://dx.doi.org/10.1021/acssensors.0c01466DOI Listing
March 2021

Non-prescription sale of antibiotics and service quality in community pharmacies in Guangzhou, China: A simulated client method.

PLoS One 2020 10;15(12):e0243555. Epub 2020 Dec 10.

Department of Health Statistics, School of Medicine, Jinan University, Guangzhou, Guangdong, P.R. China.

Objective: To measure the situation of the non-prescription sale of antibiotics and the service quality of community pharmacies in Guangzhou, China.

Methods: A simulated client method was conducted to estimate the non-prescription sale of antibiotics and service quality based on scenarios about adult acute upper respiratory tract infection in 2019. A total of 595 community pharmacies from 11 districts were investigated in Guangzhou, China. We used binary logistic regression to evaluate the factors associated with the non-prescription sale of antibiotics.

Results: The proportion of non-prescription dispensing of antibiotics was 63.1% in Guangzhou, China, with a higher incidence of antibiotic dispensing without prescription in outer districts (69.3%). Cephalosporin (44.1%) and Amoxicillin (39.0%) were sold more often than other antibiotics. Chain pharmacies had better performance on the prescription sale of antibiotics and service quality. Traditional Chinese medicine was commonly recommended by pharmacy staff.

Conclusion: Since the non-prescription sale of antibiotics is prevalent in Guangzhou, effective solutions should be determined. Strengthened public awareness and regulatory system innovation are needed.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0243555PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7728288PMC
February 2021

Recombinant Expression And Indirect ELISA For COWP And HSP70 Proteins From Cryptosporidium andersoni.

Acta Trop 2021 Feb 24;214:105767. Epub 2020 Nov 24.

Guangxi Key Laboratory of Veterinary Biotechnology, Guangxi Veterinary Research Institute, Nanning 530001, China. Electronic address:

Cryptosporidium spp. infect cattle at a high rates, and reduce milk production. Cryptosporidiosis has caused economic losses for the dairy industry. Studies in Western countries have shown that Cryptosporidium can also infect humans. Therefore, the development of methods for the early detection of Cryptosporidium is an important public health objective. Total RNA isolated from C. andersoni was used as template for generating cDNA encoding the COWP and HSP70 proteins. The recombinant plasmid, pET-32a(+)-COWP-HSP70, was constructed by double digestion and subcloning. The expression of the three recombinant proteins was induced in Escherichia coli BL21 using isopropyl-β-D-thiogalactopyranoside. The antigenicity of the recombinant proteins was examined using western blotting and indirect ELISA. The identities of the COWP fusion protein (CFP), HSP70 fusion protein (HFP), and COWP-HSP70 fusion protein (CHFP) were confirmed by BLAST searches of known sequences in GenBank respectively. The ELISA and western blot analyses indicated that all three of the proteins were highly immunogenic and antigenic. An indirect ELISA method was developed using the three recombinant proteins as coating antigens for the analysis of 40 clinical samples. The results showed that CHFP was the best candidate antigen for clinical testing, with a detection rate of 100%, compared with general parasitological screening. Above of all, the recombinant CHFP protein represents the best candidate antigen among three ones for detecting anti-Cryptosporidium antibodies in clinical samples. The development of the indirect ELISA lays the foundation for further research in immunodiagnosis and disease prevention of cryptosporidiosis.
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http://dx.doi.org/10.1016/j.actatropica.2020.105767DOI Listing
February 2021

Promoting Ge Alloying Reaction via Heterostructure Engineering for High Efficient and Ultra-Stable Sodium-Ion Storage.

Adv Sci (Weinh) 2020 Nov 8;7(22):2002358. Epub 2020 Oct 8.

Department of Chemical Engineering University of Waterloo Waterloo Ontario N2L 3G1 Canada.

Germanium (Ge)-based materials have been considered as potential anode materials for sodium-ion batteries owing to their high theoretical specific capacity. However, the poor conductivity and Na diffusivity of Ge-based materials result in retardant ion/electron transportation and insufficient sodium storage efficiency, leading to sluggish reaction kinetics. To intrinsically maximize the sodium storage capability of Ge, the nitrogen doped carbon-coated CuGe/Ge heterostructure material (CuGe/[email protected]) is developed for enhanced sodium storage. The pod-like structure of CuGe/[email protected] exposes numerous active surface to shorten ion transportation pathway while the uniform encapsulation of carbon shell improves the electron transportation, leading to enhanced reaction kinetics. Theoretical calculation reveals that CuGe/Ge heterostructure can offer decent electron conduction and lower the Na diffusion barrier, which further promotes Ge alloying reaction and improves its sodium storage capability close to its theoretical value. In addition, the uniform encapsulation of nitrogen-doped carbon on CuGe/Ge heterostructure material efficiently alleviates its volume expansion and prevents its decomposition, further ensuring its structural integrity upon cycling. Attributed to these unique superiorities, the as-prepared CuGe/[email protected] electrode demonstrates admirable discharge capacity, outstanding rate capability and prolonged cycle lifespan (178 mAh g at 4.0 A g after 4000 cycles).
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http://dx.doi.org/10.1002/advs.202002358DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7675052PMC
November 2020

Faradaic Electrodes Open a New Era for Capacitive Deionization.

Adv Sci (Weinh) 2020 Nov 11;7(22):2002213. Epub 2020 Oct 11.

Department of Chemical Engineering Waterloo Institute of Nanotechnology University of Waterloo 200 University Ave West Waterloo Ontario N2L 3G1 Canada.

Capacitive deionization (CDI) is an emerging desalination technology for effective removal of ionic species from aqueous solutions. Compared to conventional CDI, which is based on carbon electrodes and struggles with high salinity streams due to a limited salt removal capacity by ion electrosorption and excessive co-ion expulsion, the emerging Faradaic electrodes provide unique opportunities to upgrade the CDI performance, i.e., achieving much higher salt removal capacities and energy-efficient desalination for high salinity streams, due to the Faradaic reaction for ion capture. This article presents a comprehensive overview on the current developments of Faradaic electrode materials for CDI. Here, the fundamentals of Faradaic electrode-based CDI are first introduced in detail, including novel CDI cell architectures, key CDI performance metrics, ion capture mechanisms, and the design principles of Faradaic electrode materials. Three main categories of Faradaic electrode materials are summarized and discussed regarding their crystal structure, physicochemical characteristics, and desalination performance. In particular, the ion capture mechanisms in Faradaic electrode materials are highlighted to obtain a better understanding of the CDI process. Moreover, novel tailored applications, including selective ion removal and contaminant removal, are specifically introduced. Finally, the remaining challenges and research directions are also outlined to provide guidelines for future research.
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http://dx.doi.org/10.1002/advs.202002213DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7675053PMC
November 2020

Microporous framework membranes for precise molecule/ion separations.

Chem Soc Rev 2021 Jan 23;50(2):986-1029. Epub 2020 Nov 23.

Department of Chemical Engineering, University of Waterloo, 200 University Ave. W, Waterloo, Ontario N2L 3G1, Canada.

Microporous framework membranes such as metal-organic framework (MOF) membranes and covalent organic framework (COF) membranes are constructed by the controlled growth of small building blocks with large porosity and permanent well-defined micropore structures, which can overcome the ubiquitous tradeoff between membrane permeability and selectivity; they hold great promise for the enormous challenging separations in energy and environment fields. Therefore, microporous framework membranes are endowed with great expectations as next-generation membranes, and have evolved into a booming research field. Numerous novel membrane materials, versatile manipulation strategies of membrane structures, and fascinating applications have erupted in the last five years. First, this review summarizes and categorizes the microporous framework membranes with pore sizes lower than 2 nm based on their chemistry: inorganic microporous framework membranes, organic-inorganic microporous framework membranes, and organic microporous framework membranes, where the chemistry, fabrications, and differences among these membranes have been highlighted. Special attention is paid to the membrane structures and their corresponding modifications, including pore architecture, intercrystalline grain boundary, as well as their diverse control strategies. Then, the separation mechanisms of membranes are covered, such as diffusion-selectivity separation, adsorption-selectivity separation, and synergetic adsorption-diffusion-selectivity separation. Meanwhile, intricate membrane design to realize synergistic separation and some emerging mechanisms are highlighted. Finally, the applications of microporous framework membranes for precise gas separation, liquid molecule separation, and ion sieving are summarized. The remaining challenges and future perspectives in this field are discussed. This timely review may provide genuine guidance on the manipulation of membrane structures and inspire creative designs of novel membranes, promoting the sustainable development and steadily increasing prosperity of this field.
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http://dx.doi.org/10.1039/d0cs00552eDOI Listing
January 2021

d-Orbital steered active sites through ligand editing on heterometal imidazole frameworks for rechargeable zinc-air battery.

Nat Commun 2020 Nov 17;11(1):5858. Epub 2020 Nov 17.

Department of Chemical Engineering, Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada.

The implementation of pristine metal-organic frameworks as air electrode may spark fresh vitality to rechargeable zinc-air batteries, but successful employment is rare due to the challenges in regulating their electronic states and structural porosity. Here we conquer these issues by incorporating ligand vacancies and hierarchical pores into cobalt-zinc heterometal imidazole frameworks. Systematic characterization and theoretical modeling disclose that the ligand editing eases surmountable energy barrier for *OH deprotonation by its efficacy to steer metal d-orbital electron occupancy. As a stride forward, the selected cobalt-zinc heterometallic alliance lifts the energy level of unsaturated d-orbitals and optimizes their adsorption/desorption process with oxygenated intermediates. With these merits, cobalt-zinc heterometal imidazole frameworks, as a conceptually unique electrode, empowers zinc-air battery with a discharge-charge voltage gap of 0.8 V and a cyclability of 1250 h at 15 mA cm, outperforming the noble-metal benchmarks.
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http://dx.doi.org/10.1038/s41467-020-19709-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7673988PMC
November 2020

A Near-Isotropic Proton-Conducting Porous Graphene Oxide Membrane.

ACS Nano 2020 Nov 11;14(11):14947-14959. Epub 2020 Nov 11.

Department of Chemical Engineering, University of Waterloo, Ontario, N2L 3G1, Canada.

A graphene oxide (GO) membrane is an ideal separator for multiple applications due to its morphology, selectivity, controllable oxidation, and high aspect ratio of the 2D nanosheet. However, the anisotropic ion conducting nature caused by its morphology is not favorable toward through-plane conductivity, which is vital for solid-state electrolytes in electrochemical devices. Here, we present a strategy to selectively enhance the through-plane proton conductivity of a GO membrane by reducing its degree of anisotropy with pore formation on the nanosheets through the sonication-assisted Fenton reaction. The obtained porous GO (pGO) membrane is a near-isotropic, proton-conducting GO membrane, showing a degree of anisotropy as low as 2.77 and 47% enhancement of through-plane proton conductivity as opposed to the pristine GO membrane at 25 °C and 100% relative humidity. The anisotropic behavior shows an Arrhenius relationship with temperature, while the water interlayer formation between nanosheets plays a pivotal role in the anisotropic behavior under different values of relative humidity (RH); that is, as low RH increases, water molecules tend to orient in a bimodal distribution clinching the nanosheets and forming a subnanometer, high-aspect-ratio, water interlayer, resulting in its peak anisotropy. Further increase in RH fills the interlayer gap, resulting in behaviors akin to near-isotropic, bulk water. Lastly, implementation of the pGO membrane, as the solid proton-conductive electrolyte, in an alcohol fuel cell sensor has been demonstrated, showcasing the excellent selectivity and response, exceptional linearity, and ethanol detection limits as low as 25 ppm. The amalgamation of excellent performance, high customizability, facile scalability, low cost, and environmental friendliness in the present method holds considerable potential for transforming anisotropic GO membranes into near-isotropic ion conductors to further membrane development and sensing applications.
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http://dx.doi.org/10.1021/acsnano.0c04533DOI Listing
November 2020

Analogous Mixed Matrix Membranes with Self-Assembled Interface Pathways.

Angew Chem Int Ed Engl 2021 Mar 27;60(11):5864-5870. Epub 2021 Jan 27.

Department of Chemical Engineering, University of Waterloo, 200 University Ave. W, Waterloo, Ontario, N2L 3G1, Canada.

The implementation of mixed matrix membranes (MMMs) for sub-angstrom scale gas separations remains a grand challenge. Herein, a series of analogous mixed matrix membrane (AMMMs) were constructed via molecular-level hybridization by utilizing a reactive ionic liquid (RIL) as the continuous phase and graphene quantum dots (GQD) as nanofiller for sub-angstrom scale ethylene/ethane (0.416 nm/0.443 nm) separation. With a small number of GQDs (3.5 wt%) embedded in GQD/RIL AMMMs, ethylene permeability soared by 3.1-fold, and ethylene/ethane selectivity simultaneously boosted by nearly 60 % and reached up to 99.5, which outperformed most previously reported state-of-the-art membranes. Importantly, the interfacial pathway structure was visualized and their self-assembly mechanism was revealed, where the non-covalent interactions between RIL and GQDs induced the local arrangement of IL chains to self-assemble into plenty of compact and superfast interfacial pathways, contributing to the combination of superhigh permeability and selectivity.
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http://dx.doi.org/10.1002/anie.202014893DOI Listing
March 2021

Preferentially Engineering FeN Edge Sites onto Graphitic Nanosheets for Highly Active and Durable Oxygen Electrocatalysis in Rechargeable Zn-Air Batteries.

Adv Mater 2020 Dec 4;32(49):e2004900. Epub 2020 Nov 4.

Department of Chemical Engineering, Waterloo Institute for Nanotechnology, Waterloo Institute for Sustainable Energy, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada.

Single-atom FeN sites at the edges of carbon substrates are considered more active for oxygen electrocatalysis than those in plane; however, the conventional high-temperature pyrolysis process does not allow for precisely engineering the location of the active site down to atomic level. Enlightened by theoretical prediction, herein, a self-sacrificed templating approach is developed to obtain edge-enriched FeN sites integrated in the highly graphitic nanosheet architecture. The in situ formed Fe clusters are intentionally introduced to catalyze the growth of graphitic carbon, induce porous structure formation, and most importantly, facilitate the preferential anchoring of FeN to its close approximation. Due to these attributes, the as-resulted catalyst (denoted as Fe/N-G-SAC) demonstrates unprecedented catalytic activity and stability for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) by showing an impressive half-wave potential of 0.89 V for the ORR and a small overpotential of 370 mV at 10 mA cm for the OER. Moreover, the Fe/N-G-SAC cathode displays encouraging performance in a rechargeable Zn-air battery prototype with a low charge-discharge voltage gap of 0.78 V and long-term cyclability for over 240 cycles, outperforming the noble metal benchmarks.
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http://dx.doi.org/10.1002/adma.202004900DOI Listing
December 2020

Regulating the Li -Solvation Structure of Ester Electrolyte for High-Energy-Density Lithium Metal Batteries.

Small 2020 Nov 2;16(47):e2004688. Epub 2020 Nov 2.

Department of Chemical Engineering, Waterloo Institute of Nanotechnology, University of Waterloo, 200 University Ave West, Waterloo, Ontario, N2L 3G1, Canada.

The development of high-energy-density Li metal batteries are hindered by electrolyte consumption and uneven lithium deposition due to the unstable lithium-electrolyte interface (SEI). In this work, tetraglyme is introduced into ester electrolyte to regulate the Li -solvation structures for stable SEI while remaining appropriate voltage window for high-voltage cathodes. In the modified solvation structures, an enhanced lowest unoccupied molecular orbital energy level occurs, resulting in relieved electrolyte degradation. In addition, the modified solvation structures can facilitate adequate LiNO dissolution in the ester electrolyte (denoted as E-LiNO ), contributing to constant supplement of constructing highly conductive LiN O -containing SEI for dendrite-free Li deposition under high capacity condition. As a result, the Li||Cu cell-based on this electrolyte exhibits high Li plating/stripping Coulombic efficiency of 98.2% over 350 cycles. Furthermore, when paired with high-voltage LiNi Co Mn O cathodes, the E-LiNO enables a stable cycling with a high-energy-density of 296 Wh kg based on the full cell under realistic testing conditions (lean electrolyte of 3 g Ah , limited Li excess of 2.45-fold, and high areal capacity of 4 mAh cm ).
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http://dx.doi.org/10.1002/smll.202004688DOI Listing
November 2020

A review of composite solid-state electrolytes for lithium batteries: fundamentals, key materials and advanced structures.

Chem Soc Rev 2020 Dec 27;49(23):8790-8839. Epub 2020 Oct 27.

Department of Chemical Engineering, Waterloo Institute for Nanotechnology, Waterloo Institute for Sustainable Energy, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada.

All-solid-state lithium ion batteries (ASSLBs) are considered next-generation devices for energy storage due to their advantages in safety and potentially high energy density. As the key component in ASSLBs, solid-state electrolytes (SSEs) with non-flammability and good adaptability to lithium metal anodes have attracted extensive attention in recent years. Among the current SSEs, composite solid-state electrolytes (CSSEs) with multiple phases have greater flexibility to customize and combine the advantages of single-phase electrolytes, which have been widely investigated recently and regarded as promising candidates for commercial ASSLBs. Based on existing investigations, herein, we present a comprehensive overview of the recent developments in CSSEs. Initially, we introduce the historical development from solid-state ionic conductors to CSSEs, and then summarize the fundamentals including mechanisms of lithium ion transport, key evaluation parameters, design principles, and key materials. Four main types of advanced structures for CSSEs are classified and highlighted according to the recent progress. Moreover, advanced characterization and computational simulation techniques including machine learning are reviewed for the first time, and the main challenges and perspectives of CSSEs are also provided for their future development.
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http://dx.doi.org/10.1039/d0cs00305kDOI Listing
December 2020

Manipulating Au-CeO Interfacial Structure Toward Ultrahigh Mass Activity and Selectivity for CO Reduction.

ChemSusChem 2020 Dec 4;13(24):6621-6628. Epub 2020 Nov 4.

Department of Chemical Engineering, Waterloo Institute for Nanotechnology, Waterloo Institute for Sustainable Energy, University of Waterloo, Waterloo, Ontario, N2 L 3G1, Canada.

Deploying the application of Au-based catalysts directly on CO reduction reactions (CO RR) relies on the simultaneous improvement of mass activity (usually lower than 10 mA mg at -0.6 V) and selectivity. To achieve this target, we herein manipulate the interface of small-size Au (3.5 nm) and CeO nanoparticles through adjusting the surface charge of Au and CeO . The well-regulated interfacial structure not only guarantees the utmost utilization of Au, but also enhances the CO adsorption. Consequently, the mass activity (CO) of the optimal AuCeO /C catalyst reaches 139 mA mg with 97 % CO faradaic efficiency (FE ) at -0.6 V. Moreover, the strong interaction between Au and CeO endows the catalyst with excellent long-term stability. This work affords a charge-guided approach to construct the interfacial structure for CO RR and beyond.
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http://dx.doi.org/10.1002/cssc.202002133DOI Listing
December 2020

Pressure-Engineered Photoluminescence Tuning in Zero-Dimensional Lead Bromide Trimer Clusters.

Angew Chem Int Ed Engl 2021 Feb 27;60(5):2583-2587. Epub 2020 Nov 27.

Department of Chemistry, Academy for Advanced Interdisciplinary Studies, Shenzhen Engineering Research Center for Frontier Materials Synthesis at High Pressures, Southern University of Science and Technology (SUSTech), Shenzhen, Guangdong, 518055, China.

Zero-dimensional (0D) hybrid metal halides are promising light emitters. However, it is still challenging to accurately design their structures with targeted photoluminescence properties. Herein, high pressure is used to change the self-trapped exciton (STE) emission of 0D (bmpy) [ZnBr ] [Pb Br ] (bmpy: 1-butyl-1-methylpyrrolidinium). Under initial compression, the simultaneous contraction and distortion of photoactive [Pb Br ] vary the equilibrium of STE emissions between different excited states, tuning the emission color from yellow green to cyan. Notably, sufficient structural distortion under continuous compression leads to the formation of more and deeper STE states, exhibiting an unprecedented broadband white-light emission. This study reveals the structure-dependent optical properties of 0D hybrid metal halides, providing novel insights into the mechanism of STE emission.
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http://dx.doi.org/10.1002/anie.202009237DOI Listing
February 2021

Quickly SOFA Score Can Be Used as a High-Efficiency Classified Method for COVID-19 Infected Patients.

Iran J Public Health 2020 Aug;49(8):1594-1596

Key Laboratory of Fertility Preservation and Maintenance of Ministry of Education, Ningxia Medical University, Yinchuan, Ningxia, China.

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http://dx.doi.org/10.18502/ijph.v49i8.3915DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7554374PMC
August 2020
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