Publications by authors named "Jian Peng"

491 Publications

Comprehensive interactome profiling of the human Hsp70 network highlights functional differentiation of J domains.

Mol Cell 2021 Apr 27. Epub 2021 Apr 27.

Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada; Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON M5S 3E1, Canada. Electronic address:

Hsp70s comprise a deeply conserved chaperone family that has a central role in maintaining protein homeostasis. In humans, Hsp70 client specificity is provided by 49 different co-factors known as J domain proteins (JDPs). However, the cellular function and client specificity of JDPs have largely remained elusive. We have combined affinity purification-mass spectrometry (AP-MS) and proximity-dependent biotinylation (BioID) to characterize the interactome of all human JDPs and Hsp70s. The resulting network suggests specific functions for many uncharacterized JDPs, and we establish a role of conserved JDPs DNAJC9 and DNAJC27 in histone chaperoning and ciliogenesis, respectively. Unexpectedly, we find that the J domain of DNAJC27 but not of other JDPs can fully replace the function of endogenous DNAJC27, suggesting a previously unappreciated role for J domains themselves in JDP specificity. More broadly, our work expands the role of the Hsp70-regulated proteostasis network and provides a platform for further discovery of JDP-dependent functions.
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http://dx.doi.org/10.1016/j.molcel.2021.04.012DOI Listing
April 2021

Hemodynamic study of unenhanced magnetic resonance angiography using spatial labeling with multiple inversion pulses sequence: a phantom study.

Quant Imaging Med Surg 2021 May;11(5):1828-1835

Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.

Background: This study sought to explore the functional relationship between displayed vascular length and blood suppression inversion time (BSP TI) and flow velocity in a phantom, and to provide a theoretical basis for quantitatively assessing vascular hemodynamic responses using unenhanced magnetic resonance angiography (MRA) and spatial labeling with multiple inversion pulses sequence (SLEEK).

Methods: A polyethylene catheter was laid in a long rectangular container filled with pork fat. The entrance of the catheter into the container was connected to a high-pressure syringe filled with normal saline. The high-pressure injector flow rates were set at 0.0, 0.2, 0.4, 0.8, 1.2, 1.6, 2.0, and 2.4 mL/s. SLEEK was performed 19 times for each flow rate with parameter BSP TI values of 50, 75, 100, 150, 200, 300, 400, 500, 600, 700, 800, 900, 1,000, 1,100, 1,200, 1,300, 1,400, 1,600, and 1,800 ms. Maximum intensity projection was employed to reconstruct all SLEEK original images to determine the measurements of the displayed vascular lengths. A regression analysis was undertaken to assess the relationship between the displayed vascular lengths and BSP TI values for each flow rate, and to assess the relationship between the displayed vascular lengths and flow rates at each BSP TI.

Results: The displayed vascular length had a linear relationship with BSP TI for each flow rate (P<0.05) (R2=0.754, 0.941, 0.988, 0.988, 0.977, 0.966, and 0.982 for flow rates of 0.0, 0.2, 0.4, 0.8, 1.2, 1.6, and 2.0 mL/s, respectively). The displayed vascular length also had a linear relationship with flow rate for each BSP TI value (P<0.05) (R2 =0.914, 0.912, 0.834, 0.989, 0.980, 0.996, 0.992, 0.960, 0.975, 0.979, 0.982, 0.981, 0.976, and 0.993 for BSP TI 50, 75, 100, 150, 200, 300, 400, 500, 600, 700, 800, 900, 1,000, and 1,100 ms, respectively). No significant linear relationship was found between displayed vascular length and flow rate when the BSP TI value was 1,200 ms (P>0.05).

Conclusions: Vascular displayed length has a linear relationship to BSP TI for flow ranges from 0.0 to 2.0 mL/s. Vascular displayed length has a linear relationship to flow rate for BSP TI values of 50 to 1,100 ms. Flow rate can be assessed in relation to vascular displayed length.
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http://dx.doi.org/10.21037/qims-20-633DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8047366PMC
May 2021

Sulfonic-Group-Grafted TiCT MXene: A Silver Bullet to Settle the Instability of Polyaniline toward High-Performance Zn-Ion Batteries.

ACS Nano 2021 Apr 29. Epub 2021 Apr 29.

College of Materials Science and Engineering, Shenzhen University, Shenzhen 518055, China.

Polyaniline (PANI) is a promising cathode material for Zn-ion batteries (ZIBs) due to its intrinsic conductivity and redox activity; however, the achievements of PANI in high-performance ZIBs are largely hindered by its instability during the repeated charge/discharge. Taking advantage of the high conductivity, flexibility, and grafting ability together, a surface-engineered TiCT MXene is designed as a silver bullet to fight against the deprotonation and swelling/shrinking issues occurring in the redox process of PANI, which are the origins of its instability. Specifically, the sulfonic-group-grafted TiCT(S-TiCT) continuously provides protons to improve the protonation degree of PANI and maintains the polymer backbone at a locally low pH, which effectively inhibits deprotonation and brings high redox activity along with good reversibility. Meanwhile, the conductive and flexible natures of S-TiCT assist the fast redox reaction of PANI and concurrently buffer its corresponding swelling/shrinking. Therefore, the S-TiCT-enhanced PANI cathode simultaneously achieves a high discharge capacity of 262 mAh g at 0.5 A g, a superior rate capability of 160 mAh g at 15 A g, and a good cyclability over 5000 cycles with 100% coulombic efficiency. This work enlightens the development of versatile MXene surface engineering for advanced batteries.
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http://dx.doi.org/10.1021/acsnano.1c02215DOI Listing
April 2021

A Low-Strain Potassium-Rich Prussian Blue Analogue Cathode for High Power Potassium-Ion Batteries.

Angew Chem Int Ed Engl 2021 Mar 29. Epub 2021 Mar 29.

Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Renewable Energy Conversion and Storage Center (RECAST), College of Chemistry, Nankai University, Tianjin, 300071, China.

Most of the cathode materials for potassium ion batteries (PIBs) suffer from poor structural stability due to the large ionic radius of K , resulting in poor cycling stability. Here we report a low-strain potassium-rich K Ni[Fe(CN) ] ⋅0.49 H O (KNiHCF) as a cathode material for PIBs. The as-prepared KNiHCF cathode can deliver reversible discharge capacity of 62.8 mAh g at 100 mA g , with a high discharge voltage of 3.82 V. It can also achieve a superior rate performance of 45.8 mAh g at 5000 mA g , with a capacity retention of 88.6 % after 100 cycles. The superior performance of KNiHCF cathode results from low-strain de-/intercalation mechanism, intrinsic semiconductor property and low potassium diffusion energy barrier. The high power density and long-term stability of KNiHCF//graphite full cell confirmed the feasibility of K-rich KNiHCF cathode in PIBs. This work provides guidance to develop Prussian blue analogues as cathode materials for PIBs.
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http://dx.doi.org/10.1002/anie.202103475DOI Listing
March 2021

Highly Sensitive Detection of Low-Abundance BRAF V600E Mutation in Fine-Needle Aspiration Samples by Zip Recombinase Polymerase Amplification.

Anal Chem 2021 04 25;93(13):5621-5628. Epub 2021 Mar 25.

The Center for Clinical Molecular Medical Detection, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, P. R. China.

Papillary thyroid carcinoma (PTC) is the most common thyroid cancer with high incidence in endocrine tumors, which emphasizes the significance of accurate diagnostics. Still, the commonly used cytological method (fine-needle aspiration (FNA) cytology) and molecular diagnostic methods (such as PCR and sequencing) are limited in terms of diagnostic time, sensitivity, and user-friendliness. In this study, we introduce a novel Zip recombinase polymerase amplification (Z-RPA) strategy to efficiently detect rare mutant alleles in PTC fine-needle aspiration samples, which is sensitive, fast, and simple to manipulate. Using Zip nucleic acid (ZNA) probes to clamp the mutation region, the phi 29 polymerase could selectively displace mismatched ZNA probes and start amplification, while leaving complementary ZNA probes untouched and blocking amplification according to genotype. We demonstrated the good sensitivity and specificity of this strategy with optimized conditions and design, which enabled detection of BRAF V600E mutation in a total 4 ng of genomic DNA within 40 min (≈1 copy). Robust behavior in clinical specimen analysis was also demonstrated. The Z-RPA strategy provides a pragmatic approach to rapidly, sensitively, and easily detect BRAF V600E mutation in clinical fine-needle aspiration samples, which is a promising method for early cancer diagnosis and treatment guideline.
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http://dx.doi.org/10.1021/acs.analchem.1c00405DOI Listing
April 2021

Hydratability and improved fermentability in vitro of guar gum by combination of xanthan gum.

Carbohydr Polym 2021 Apr 22;258:117625. Epub 2021 Jan 22.

Department of Animal Nutrition and Feed Science, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China. Electronic address:

Dietary fibers with high water-binding capacity (WBC), swelling capacity (SC) and fermentability regulate food intake and intestinal microbiota. However, dietary fibers with such properties are generally rare or expensive. We evaluated SC, WBC, fermentability and bacterial shifts during in vitro fermentations of guar gum (GG), xanthan gum (XG) and the combined gum (CG) of XG and GG. SC and WBC were enhanced by the combination of GG and XG. Fermentation of CG showed similar Short chain fatty acids production and lower molecular weight compared with GG. Analyzing of fermentation kinetics by logistic-exponential model, initial fractional rate of degradation of CG were remarkable higher than GG. Microbiota analysis revealed that GG enriched Fusobacterium, Bacteriodes and Prevotella_9, and CG lead to promotion of Sphaerochaeta, Prevotella_9, Bacteroides and Christensenellaceae_R-7_group. These data suggest that combination of XG to GG changed hydration and fermentation characteristics of GG, and CG resulted in promotion of beneficial microbiota.
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http://dx.doi.org/10.1016/j.carbpol.2021.117625DOI Listing
April 2021

Overcoming Long-Term Catastrophic Forgetting Through Adversarial Neural Pruning and Synaptic Consolidation.

IEEE Trans Neural Netw Learn Syst 2021 Feb 12;PP. Epub 2021 Feb 12.

Enabling a neural network to sequentially learn multiple tasks is of great significance for expanding the applicability of neural networks in real-world applications. However, artificial neural networks face the well-known problem of catastrophic forgetting. What is worse, the degradation of previously learned skills becomes more severe as the task sequence increases, known as the long-term catastrophic forgetting. It is due to two facts: first, as the model learns more tasks, the intersection of the low-error parameter subspace satisfying for these tasks becomes smaller or even does not exist; second, when the model learns a new task, the cumulative error keeps increasing as the model tries to protect the parameter configuration of previous tasks from interference. Inspired by the memory consolidation mechanism in mammalian brains with synaptic plasticity, we propose a confrontation mechanism in which Adversarial Neural Pruning and synaptic Consolidation (ANPyC) is used to overcome the long-term catastrophic forgetting issue. The neural pruning acts as long-term depression to prune task-irrelevant parameters, while the novel synaptic consolidation acts as long-term potentiation to strengthen task-relevant parameters. During the training, this confrontation achieves a balance in that only crucial parameters remain, and non-significant parameters are freed to learn subsequent tasks. ANPyC avoids forgetting important information and makes the model efficient to learn a large number of tasks. Specifically, the neural pruning iteratively relaxes the current task's parameter conditions to expand the common parameter subspace of the task; the synaptic consolidation strategy, which consists of a structure-aware parameter-importance measurement and an element-wise parameter updating strategy, decreases the cumulative error when learning new tasks. Our approach encourages the synapse to be sparse and polarized, which enables long-term learning and memory. ANPyC exhibits effectiveness and generalization on both image classification and generation tasks with multiple layer perceptron, convolutional neural networks, and generative adversarial networks, and variational autoencoder. The full source code is available at https://github.com/GeoX-Lab/ANPyC.
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http://dx.doi.org/10.1109/TNNLS.2021.3056201DOI Listing
February 2021

The impact of malnutrition on atrial fibrillation recurrence post ablation.

Nutr Metab Cardiovasc Dis 2021 03 10;31(3):834-840. Epub 2020 Dec 10.

Department of Cardiology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong Province, China. Electronic address:

Background And Aims: Both malnutrition and atrial fibrillation (AF) are the major health problems in modern society. Only a few studies focused on the relationship between malnutrition and recurrence of atrial arrhythmias post AF ablation (AF recurrence), which used body mass index (BMI) as nutrition assessment tool. However, BMI can't credibly reflect body composition and has limitation in patients with water-sodium retention. In this study, we used controlling nutritional status score (CONUT score) and geriatric nutritional risk index (GNRI) to identify the malnutrition patients and explored the effect of malnutrition on AF recurrence.

Methods And Results: This retrospective study included 246 patients who underwent AF ablation. During a median 11-month follow-up, 77 patients (31.3%) experienced AF recurrence. The recurrence group had higher CONUT score (2.3 ± 1.5 vs. 0.9 ± 1.0, P < 0.001) and lower GNRI (99.9 ± 7.6 vs. 103.9 ± 5.6, P < 0.001). After balancing the traditional risk factors, both CONUT score (OR: 2.614, 95%CI: 1.831-3.731, P < 0.001) and GNRI (OR: 0.884, 95%CI: 0.828-0.944, P < 0.001) were the independent predictors for AF recurrence. Pre-ablation CONUT score ≥1 and GNRI≥95.66 are indicative of AF recurrence. Adding CONUT score or GNRI to the base prediction model for AF recurrence significantly improved the discrimination and calibration. However, adding BMI to the base prediction model did not improve the model performance.

Conclusions: CONUT score and GNRI are ideal tools to evaluate the nutrition status of AF patients. Undernourished patients are more likely to suffer from AF recurrence. Improving nutrition status may be a potential target for reducing the postoperative recurrence rate.
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http://dx.doi.org/10.1016/j.numecd.2020.12.003DOI Listing
March 2021

Epigallocatechin-3-gallate, an active ingredient of Traditional Chinese Medicines, inhibits the 3CLpro activity of SARS-CoV-2.

Int J Biol Macromol 2021 Apr 4;176:1-12. Epub 2021 Feb 4.

Department of Cell Biology, School of Life Sciences, Central South University, Changsha 410013, China; Hunan Key Laboratory of Animal Models for Human Diseases, Hunan Key Laboratory of Medical Genetics & Center for Medical Genetics, School of Life Sciences, Central South University, Changsha 410013, China. Electronic address:

SARS-CoV-2 is the etiological agent responsible for the ongoing pandemic of coronavirus disease 2019 (COVID-19). The main protease of SARS-CoV-2, 3CLpro, is an attractive target for antiviral inhibitors due to its indispensable role in viral replication and gene expression of viral proteins. The search of compounds that can effectively inhibit the crucial activity of 3CLpro, which results to interference of the virus life cycle, is now widely pursued. Here, we report that epigallocatechin-3-gallate (EGCG), an active ingredient of Chinese herbal medicine (CHM), is a potent inhibitor of 3CLpro with half-maximum inhibitory concentration (IC50) of 0.874 ± 0.005 μM. In the study, we retrospectively analyzed the clinical data of 123 cases of COVID-19 patients, and found three effective Traditional Chinese Medicines (TCM) prescriptions. Multiple strategies were performed to screen potent inhibitors of SARS-CoV-2 3CLpro from the active ingredients of TCMs, including network pharmacology, molecular docking, surface plasmon resonance (SPR) binding assay and fluorescence resonance energy transfer (FRET)-based inhibition assay. The SPR assay showed good interaction between EGCG and 3CLpro with KD ~6.17 μM, suggesting a relatively high affinity of EGCG with SARS-CoV-2 3CLpro. Our results provide critical insights into the mechanism of action of EGCG as a potential therapeutic agent against COVID-19.
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http://dx.doi.org/10.1016/j.ijbiomac.2021.02.012DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7859723PMC
April 2021

Gly-Pro-Ala peptide and FGSHF3 exert protective effects in DON-induced toxicity and intestinal damage via decreasing oxidative stress.

Food Res Int 2021 Jan 26;139:109840. Epub 2020 Oct 26.

Department of Animal Nutrition and Feed Science, College of Animal Science and Technology, Huazhong Agricultural University, 430070 Wuhan, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, Hubei, China. Electronic address:

Deoxynivalenol (DON), a common mycotoxin, usually induces oxidative stress and intestinal injury of humans and animals. This study aims to investigate the protective effect of Gly-Pro-Ala (GPA) peptide, isolated from fish skin gelatin hydrolysate fraction 3 (FGSHF3), on alleviating the toxicity and oxidative stress induced by DON in the mice and IPEC-J2 cells. DON treatment decreases average daily gain and feeds intake, which causes enlargement of the liver and spleen. FGSHF3 (200 mg/kg) and GPA (200 mg/kg) treatment significantly increase average daily gain and inhibits enlargement of the liver and spleen. Furthermore, FGSHF3 and GPA treatment significantly alleviates intestinal injury and maintains tight junction in mice and IPEC-J2 cells. FGSHF3 and GPA treatment significantly inhibits ROS and MDA production and enhances antioxidant enzyme activity, such as CAT, SOD-1, GCLM, GCLC, and GSH-PX. Furthermore, FGSHF3 and GPA treatment promote Nrf2 migration from the cytoplasm to the nucleus, resulting in exerting antioxidant effects. And its effects are abolished after Nrf2 is knockdown by siRNA. Overall, our results suggest GPA peptide may be a promising candidate for the alleviation of DON-induced toxicity in humans and animals.
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http://dx.doi.org/10.1016/j.foodres.2020.109840DOI Listing
January 2021

Human activity vs. climate change: Distinguishing dominant drivers on LAI dynamics in karst region of southwest China.

Sci Total Environ 2021 May 24;769:144297. Epub 2020 Dec 24.

TERRA Teaching and Research Centre, Gembloux Agro-Bio Tech, University of Liège, Gembloux 5030, Belgium.

Understanding the impacts of climate change and human activities on vegetation is of great significance to the sustainable development of terrestrial ecosystems. However, most studies focused on the overall impact over a period and rarely examined the time-lag effect of vegetation's response to climatic factors when exploring the driving mechanisms of vegetation dynamics. In this study, we identified key areas driven by either positive or negative human activities and climate change. Taking the three karst provinces of southwest China as the case study area, a Leaf Area Index (LAI)-climate model was constructed by quantifying the time-lag effect. Then the associated residual threshold was calculated to identify the vegetation change areas dominated by human activities and climate change. The results showed that, during the implementation period of ecological restoration projects from 1999 to 2015, positive impact areas of human activities were mainly distributed among the implementation areas of ecological restoration projects, accounting for 5.61% of the total area. For another, the negative impact areas were mainly distributed across the mountainous area of Yunnan Province, accounting for 1.30% of the total area. Karst landform had the greatest influence on the areas dominated by positive human activities, whereas both topography and karst landform significantly affected the areas dominated by negative human activities. Urban development level had the greatest impact on the areas dominated by climate change. The outcomes of this study provided scientific supports for the sustainable development of ecological restoration projects in China's karst region.
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http://dx.doi.org/10.1016/j.scitotenv.2020.144297DOI Listing
May 2021

Plasmon-driven nanowire actuators for on-chip manipulation.

Nat Commun 2021 Jan 15;12(1):385. Epub 2021 Jan 15.

Laboratory of Integrated Opto-Mechanics and Electronics, Shanghai Key Laboratory of Modern Optical System, Engineering Research Center of Optical Instrument and System (Ministry of Education), University of Shanghai for Science and Technology, 200093, Shanghai, China.

Chemically synthesized metal nanowires are promising building blocks for next-generation photonic integrated circuits, but technological implementation in monolithic integration will be severely hampered by the lack of controllable and precise manipulation approaches, due to the strong adhesion of nanowires to substrates in non-liquid environments. Here, we demonstrate this obstacle can be removed by our proposed earthworm-like peristaltic crawling motion mechanism, based on the synergistic expansion, friction, and contraction in plasmon-driven metal nanowires in non-liquid environments. The evanescently excited surface plasmon greatly enhances the heating effect in metal nanowires, thereby generating surface acoustic waves to drive the nanowires crawling along silica microfibres. Advantages include sub-nanometer positioning accuracy, low actuation power, and self-parallel parking. We further demonstrate on-chip manipulations including transporting, positioning, orientation, and sorting, with on-situ operation, high selectivity, and great versatility. Our work paves the way to realize full co-integration of various functionalized photonic components on single chips.
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http://dx.doi.org/10.1038/s41467-020-20683-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7810692PMC
January 2021

Toll-like receptor 7 deficiency suppresses type 1 diabetes development by modulating B-cell differentiation and function.

Cell Mol Immunol 2021 Feb 11;18(2):328-338. Epub 2021 Jan 11.

Section of Endocrinology, Department of Internal Medicine, School of Medicine, Yale University, New Haven, CT, USA.

Innate immunity mediated by Toll-like receptors (TLRs), which can recognize pathogen molecular patterns, plays a critical role in type 1 diabetes development. TLR7 is a pattern recognition receptor that senses single-stranded RNAs from viruses and host tissue cells; however, its role in type 1 diabetes development remains unclear. In our study, we discovered that Tlr7-deficient (Tlr7) nonobese diabetic (NOD) mice, a model of human type 1 diabetes, exhibited a significantly delayed onset and reduced incidence of type 1 diabetes compared with Tlr7-sufficient (Tlr7) NOD mice. Mechanistic investigations showed that Tlr7 deficiency significantly altered B-cell differentiation and immunoglobulin production. Moreover, Tlr7 NOD B cells were found to suppress diabetogenic CD4 T-cell responses and protect immunodeficient NOD mice from developing diabetes induced by diabetogenic T cells. In addition, we found that Tlr7 deficiency suppressed the antigen-presenting functions of B cells and inhibited cytotoxic CD8 T-cell activation by downregulating the expression of both nonclassical and classical MHC class I (MHC-I) molecules on B cells. Our data suggest that TLR7 contributes to type 1 diabetes development by regulating B-cell functions and subsequent interactions with T cells. Therefore, therapeutically targeting TLR7 may prove beneficial for disease protection.
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http://dx.doi.org/10.1038/s41423-020-00590-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8027372PMC
February 2021

Long-term follow-up in patients with Brugada Syndrome in South China.

Ann Noninvasive Electrocardiol 2021 Jan 8:e12823. Epub 2021 Jan 8.

First People's Hospital of Zhaoqing, Zhaoqing, China.

Objective: To evaluate the presence of Brugada electrocardiogram (ECG) pattern, clinical characteristics, treatment, and long-term prognosis of Brugada syndrome in southern Chinese population.

Methods: This prospective study consisted of a consecutive series of patients with diagnostic coved type I Brugada ECG pattern at baseline between January 2007 and February 2020. Histories of symptoms including ventricular tachycardia (VT)/ventricular fibrillation (VF) episode, syncope, and family history of Brugada Syndrome (BrS) or unexplained sudden cardiac death were collected. Electrophysiological study and implantable cardioverter-defibrillator (ICD) were performed. All patients included in this study were followed up in the outpatient department every 6 months after baseline evaluation. Occurrences of syncope, VF, and sudden death were independently analyzed by two cardiologists.

Results: 45 (56.3%) patients were diagnosed with BrS. During a mean follow-up of 7.9 ± 3.6 years, six patients had experienced documented VF/sudden cardiac death (SCD) or recurrent syncope. Two patients experienced episodes of syncope more than once. Two patients experienced onset of electrical storm with a total of 11 episodes of VF. There were 50% of these events occurring in fever status. One of patient with BrS died of SCD.

Conclusion: There was a very low prevalence of Brugada syndrome in southern Chinese population. The risk of arrhythmic events was low in asymptomatic patients. ICD was high effective in preventing SCD without adverse device outcome in long-term follow-up. Fever can lead to predispose to malignant arrhythmia, and aggressive treatment of febrile state in Brugada syndrome was recommended.
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http://dx.doi.org/10.1111/anec.12823DOI Listing
January 2021

Novel Cecropin-4 Derived Peptides against Methicillin-Resistant .

Antibiotics (Basel) 2021 Jan 1;10(1). Epub 2021 Jan 1.

Infectious Diseases Division, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, RI 02903, USA.

Increasing microbial resistance, coupled with a lack of new antimicrobial discovery, has led researchers to refocus on antimicrobial peptides (AMPs) as novel therapeutic candidates. Significantly, the less toxic cecropins have gained widespread attention for potential antibacterial agent development. However, the narrow activity spectrum and long sequence remain the primary limitations of this approach. In this study, we truncated and modified cecropin 4 (41 amino acids) by varying the charge and hydrophobicity balance to obtain smaller AMPs. The derivative peptide C18 (16 amino acids) demonstrated high antibacterial activity against Gram-negative and Gram-positive bacteria, as well as yeasts. Moreover, C18 demonstrated a minimal inhibitory concentration (MIC) of 4 µg/mL against the methicillin-resistant (MRSA) and showed synergy with daptomycin with a fractional inhibition concentration index (FICI) value of 0.313. Similar to traditional cecropins, C18 altered the membrane potential, increased fluidity, and caused membrane breakage at 32 µg/mL. Importantly, C18 eliminated 99% persisters at 10 × MIC within 20 min and reduced the biofilm adherence by ~40% and 35% at 32 and 16 µg/mL. Besides, C18 possessed a strong binding ability with DNA at 7.8 μM and down-regulated the expression of virulence factor genes like agrA, fnb-A, and clf-1 by more than 5-fold ( < 0.05). Interestingly, in the model, C18 rescued more than 80% of larva infected with the MRSA throughout 120-h post-infection at a single dose of 8 mg/kg ( < 0.05). In conclusion, this study provides a reference for the transformation of cecropin to derive small peptides and presents C18 as an attractive therapeutic candidate to be developed to treat severe MRSA infections.
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http://dx.doi.org/10.3390/antibiotics10010036DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7824259PMC
January 2021

Batch equalization with a generative adversarial network.

Bioinformatics 2020 12;36(Suppl_2):i875-i883

Google Research, 1600 Amphitheatre Parkway Mountain View, CA 94043.

Motivation: Advances in automation and imaging have made it possible to capture a large image dataset that spans multiple experimental batches of data. However, accurate biological comparison across the batches is challenged by batch-to-batch variation (i.e. batch effect) due to uncontrollable experimental noise (e.g. varying stain intensity or cell density). Previous approaches to minimize the batch effect have commonly focused on normalizing the low-dimensional image measurements such as an embedding generated by a neural network. However, normalization of the embedding could suffer from over-correction and alter true biological features (e.g. cell size) due to our limited ability to interpret the effect of the normalization on the embedding space. Although techniques like flat-field correction can be applied to normalize the image values directly, they are limited transformations that handle only simple artifacts due to batch effect.

Results: We present a neural network-based batch equalization method that can transfer images from one batch to another while preserving the biological phenotype. The equalization method is trained as a generative adversarial network (GAN), using the StarGAN architecture that has shown considerable ability in style transfer. After incorporating new objectives that disentangle batch effect from biological features, we show that the equalized images have less batch information and preserve the biological information. We also demonstrate that the same model training parameters can generalize to two dramatically different types of cells, indicating this approach could be broadly applicable.

Availability And Implementation: https://github.com/tensorflow/gan/tree/master/tensorflow_gan/examples/stargan.

Supplementary Information: Supplementary data are available at Bioinformatics online.
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http://dx.doi.org/10.1093/bioinformatics/btaa819DOI Listing
December 2020

Genome-wide identification of target genes for transcription factor BR-C in the silkworm, Bombyx mori.

Insect Sci 2020 Dec 28. Epub 2020 Dec 28.

State Key Laboratory of Silkworm Genome Biology, Biological Science Research Center, Southwest University, Chongqing, 400715, China.

Transcription factor Broad Complex (BR-C) is an ecdysone primary response gene in insects and participates in the regulation of insect growth and development. In this study, we performed a genome-wide identification of BR-C target genes in silkworm (Bombyx mori) using chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq). As a result, a total of 1006 BR-C ChIP peaks were identified, and 15% of peaks were located in the promoter regions of 133 protein-coding genes. Functional annotation revealed that these ChIP peak-associated genes, as potential BR-C targets, were enriched in pathways related to biosynthetic process, metabolic process, and development. Transcriptome analysis and quantitative real-time polymerase chain reaction (PCR) examination revealed that developmental changes in expression patterns of a portion of potential BR-C targets, including HR96 and GC-α1, were similar to those of BR-C. ChIP-PCR examination confirmed that BR-C could directly bind to the promoters of potential targets. Further, dual luciferase assays demonstrated that HR96 promoter activity was significantly upregulated following BR-C overexpression, and this upregulation was abolished when the binding motif in the promoter was truncated. This study will be helpful for deciphering the regulatory roles of BR-C during insect growth and development.
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http://dx.doi.org/10.1111/1744-7917.12893DOI Listing
December 2020

Tp-e and (Tp-e)/QT ratio as a non-invasive risk factors for malignant ventricular arrhythmia in patients with idiopathic ventricular premature complexes.

J Clin Lab Anal 2021 Feb 17;35(2):e23636. Epub 2020 Dec 17.

Department of Cardiology, The First People's Hospital of Zhaoqing City, Zhaoqing City, China.

Background: To evaluate the role of Tp-e and (Tp-e)/QT ratio in differentiating benign ventricular premature complex (VPC) and malignant polymorphic ventricular tachycardia (PVT).

Methods: From January 2017 to December 2017, patients with documented polymorphic ventricular tachycardia (PVT) or ventricular fibrillation (VF) were consecutive included and classified as PVT/VF group. Sixty age- and sex-matched healthy individuals were recruited as comparative control and subdivided into non-VPC and VPC group. Clinical characteristics and Tp-e and Tp-e/QT ratio between the three groups were compared.

Results: Tp-e and (Tp-e)/QT ratio were significantly higher in patients of PVT/VF group compared with the other two groups (P < .001). Episodes of syncope were more frequent in patients with PVT/VF (P < .05). The sensitivity and specificity of a Tp-e interval ≥86 ms for malignant arrhythmias triggered by VPCs were 88% and 66%, respectively, while the sensitivity and specificity of the Tp-e/QT ratio ≥0.24 were 82% and 70%, respectively. Five patients complained recurrence of syncope in the PVT/VF group and 1 patient died with mean follow-up of 18 months.

Conclusion: Tp-e interval and the Tp-Te/QT ratio is significantly increased in patients with PVT/VF and may be used as a novel non-invasive marker of differentiating malignant and benign VPC.
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http://dx.doi.org/10.1002/jcla.23636DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7891518PMC
February 2021

Co-Evolution of Complex Network Public Goods Game under the Edges Rules.

Entropy (Basel) 2020 Feb 8;22(2). Epub 2020 Feb 8.

School of Software, Yunnan University, Kunming 650000, China.

The reconnection of broken edges is an effective way to avoid drawback for the commons in past studies. Inspired by this, we proposed a public goods game model under the edges rules, where we evaluate the weight of edges by their nodes' payoff. The results proved that the game obtains a larger range of cooperation with a small gain factor by this proposed model by consulting Monte Carlo simulations (MCS) and real experiments. Furthermore, as the following the course of game and discussing the reason of cooperation, in the research, we found that the distribution entropy of the excess average degree is able to embody and predict the presence of cooperation.
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http://dx.doi.org/10.3390/e22020199DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7516628PMC
February 2020

Effects of probiotic litchi juice on immunomodulatory function and gut microbiota in mice.

Food Res Int 2020 11 12;137:109433. Epub 2020 Jun 12.

Sericultural & Argi-Food Research Institute, Guangdong Academy of Agricultural Sciences/Key Laboratory of Functional Foods, Ministry of Agriculture and Rural Affairs/Guangdong Key Laboratory of Agricultural Products Processing, No. 133 Yiheng Street., Dongguanzhuang Road, Tianhe District, Guangzhou 510610, China. Electronic address:

Development new functional foods containing probiotics had gained much attention during the past two decades. In this study, probiotic litchi juice was developed, and its effects on immunomodulatory function and gut microbiota were evaluated. Firstly, the litchi juice was fermented with Lactobacillus casei, which increased total phenolic, total flavone, and exopolysaccharide contents of the litchi juice. Hence, the immunomodulatory influence of fermented litchi juice (FL) was investigated in cyclophosphamide-induced mice. The results showed that FL enhanced immune organs indexes (spleen, thymus) and antioxidant capacity, improved the secretions of cytokines (IL-2, IL-6) and immunoglobulins (IgA, IgG, SIgA), and protected the intestinal tract. Finally, the effect of FL on gut microbiota was analyzed by high-throughput sequencing analysis. The changes in the relative abundance of dominant microbe were investigated at phylum and genus levels, respectively. After treatment with FL, the relative abundance of Firmicutes phylum was dramatically increased, as well as the genera of Faecalibaculum, Lactobacillus, and Akkermansia. These findings indicated that probiotic litchi juice could alleviate immune dysfunction and modify gut microbiota structure of mice, which provide a potential functional food to improve the host health.
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http://dx.doi.org/10.1016/j.foodres.2020.109433DOI Listing
November 2020

A marine microbiome antifungal targets urgent-threat drug-resistant fungi.

Science 2020 11;370(6519):974-978

Pharmaceutical Sciences Division, University of Wisconsin-Madison, Madison, WI, USA.

New antifungal drugs are urgently needed to address the emergence and transcontinental spread of fungal infectious diseases, such as pandrug-resistant Leveraging the microbiomes of marine animals and cutting-edge metabolomics and genomic tools, we identified encouraging lead antifungal molecules with in vivo efficacy. The most promising lead, turbinmicin, displays potent in vitro and mouse-model efficacy toward multiple-drug-resistant fungal pathogens, exhibits a wide safety index, and functions through a fungal-specific mode of action, targeting Sec14 of the vesicular trafficking pathway. The efficacy, safety, and mode of action distinct from other antifungal drugs make turbinmicin a highly promising antifungal drug lead to help address devastating global fungal pathogens such as
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http://dx.doi.org/10.1126/science.abd6919DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7756952PMC
November 2020

Novel Insights into Adipogenesis from the Perspective of Transcriptional and RNA N6-Methyladenosine-Mediated Post-Transcriptional Regulation.

Adv Sci (Weinh) 2020 Nov 3;7(21):2001563. Epub 2020 Sep 3.

Department of Animal Nutrition and Feed Science College of Animal Science and Technology Huazhong Agricultural University Wuhan 430070 China.

Obesity is a critical risk factor causing the development of metabolic diseases and cancers. Its increasing prevalence worldwide has aroused great concerns of the researchers on adipose development and metabolic function. During adipose expansion, adipogenesis is a way to store lipids as well as to avoid lipotoxicity in other tissues, and may be an approach to offset the negative metabolic effects of obesity. In this Review, the transcriptional regulation of adipogenesis is outlined to characterize numerous biological processes in research on the determination of adipocyte fate and regulation of adipogenic differentiation. Notably, one of the post-transcriptional modifications of mRNA, namely, N-methyladenosine (mA), has been recently found to play a role in adipogenesis. Here, the roles of mA-related enzymes and proteins in adipogenesis, with a particular focus on how these mA-related proteins function at different stages of adipogenesis, are mainly discussed. The Review also highlights the coordination role of the transcriptional and post-transcriptional (RNA mA methylation) regulation in adipogenesis and related biological processes. In this context, a better understanding of adipogenesis at both the transcriptional and post-transcriptional levels may facilitate the development of novel strategies to improve metabolic health in obesity.
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http://dx.doi.org/10.1002/advs.202001563DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7610318PMC
November 2020

TLR9 Deficiency in B Cells Promotes Immune Tolerance via Interleukin-10 in a Type 1 Diabetes Mouse Model.

Diabetes 2021 02 5;70(2):504-515. Epub 2020 Nov 5.

Section of Endocrinology, School of Medicine, Yale University, New Haven, CT

Toll-like receptor 9 (TLR9) is highly expressed in B cells, and B cells are important in the pathogenesis of type 1 diabetes (T1D) development. However, the intrinsic effect of TLR9 in B cells on β-cell autoimmunity is not known. To fill this knowledge gap, we generated NOD mice with a B-cell-specific deficiency of TLR9 (TLR9/CD19-Cre+ NOD). The B-cell-specific deletion of TLR9 resulted in near-complete protection from T1D development. Diabetes protection was accompanied by an increased proportion of interleukin-10 (IL-10)-producing B cells. We also found that TLR9-deficient B cells were hyporesponsive to both innate and adaptive immune stimuli. This suggested that TLR9 in B cells modulates T1D susceptibility in NOD mice by changing the frequency and function of IL-10-producing B cells. Molecular analysis revealed a network of TLR9 with matrix metalloproteinases, tissue inhibitor of metalloproteinase-1, and CD40, all of which are interconnected with IL-10. Our study has highlighted an important connection of an innate immune molecule in B cells to the immunopathogenesis of T1D. Thus, targeting the TLR9 pathway, specifically in B cells, may provide a novel therapeutic strategy for T1D treatment.
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http://dx.doi.org/10.2337/db20-0373DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7881860PMC
February 2021

Psychometric properties of patient-reported outcome measures of self-management for cancer survivors: a systematic review protocol using COSMIN methodology.

BMJ Open 2020 11 3;10(11):e038983. Epub 2020 Nov 3.

School of Nursing, Fudan University, Shanghai, China

Introduction: Self-management is an important strategy for cancer survivors. Evaluating self-management is essential for planning nursing interventions that promote self-management and for measuring the contribution of nursing to health outcomes. Many patient-reported outcome measures (PROMs) have been designed and used to assess self-management in cancer survivors. However, it is unclear which PROM has the best reliability and validity. Therefore, the goal is to systematically review the psychometric properties of existing self-management PROMs and determine which PROM is best for cancer survivors.

Methods And Analysis: This systematic review will be conducted according to the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) guidelines for systematic reviews of PROMs. Ten electronic literature databases (PubMed, EMBASE and so on) and two websites for PROMs will be searched from inception to 1 March 2020. Studies testing the psychometric properties of PROMs assessing self-management for cancer survivors, published in either English or Chinese, will be included. Two independent reviewers determined the eligibility of the studies and will independently extract the data. Risk of bias will be assessed using the COSMIN risk-of-bias checklist, and the quality of the results will be assessed using specific COSMIN quality criteria.

Ethics And Dissemination: It is not necessary to obtain ethical approval for this systematic review protocol. The results will be published in a peer-reviewed journal and presented at a relevant conference.

Prospero Registration Number: CRD42020149120.
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http://dx.doi.org/10.1136/bmjopen-2020-038983DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7640513PMC
November 2020

Application of large-scale targeted sequencing to distinguish multiple lung primary tumors from intrapulmonary metastases.

Sci Rep 2020 11 2;10(1):18840. Epub 2020 Nov 2.

The Center for Clinical Molecular Medical Detection, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, People's Republic of China.

The effective differentiation between multiple primary lung tumors (MPs) and intrapulmonary metastases (IMs) in patients is imperative to discover the exact disease stage and to select the most appropriate treatment. In this study, the authors was to evaluate the efficacy and validity of large-scale targeted sequencing (LSTS) as a supplement to estimate whether multifocal lung cancers (MLCs) are primary or metastatic. Targeted sequencing of 520 cancer-related oncogenes was performed on 36 distinct tumors from 16 patients with MPs. Pairing analysis was performed to evaluate the somatic mutation pattern of MLCs in each patient. A total of 25 tumor pairs from 16 patients were sequenced, 88% (n = 22) of which were classified as MPs by LSTS, consistent with clinical diagnosis. One tumor pair from a patient with lymph node metastases had highly consistent somatic mutation profiles, thus predicted as a primary-metastatic pair. In addition, some matched mutations were observed in the remaining two paired ground-glass nodules (GGNs) and classified as high-probability IMs by LSTS. Our study revealed that LSTS can potentially facilitate the distinction of MPs from IMs. In addition, our results provide new genomic evidence of the presence of cancer invasion in GGNs, even pure GGNs.
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http://dx.doi.org/10.1038/s41598-020-75935-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7606457PMC
November 2020

Gut Microbiological Disorders Reduce Semen Utilization Rate in Duroc Boars.

Front Microbiol 2020 8;11:581926. Epub 2020 Oct 8.

Department of Animal Nutrition and Feed Science, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, China.

Although rising evidence suggests that the gut microbiota is closely related to host health, the effects of gut microbiota on male fertility are still rarely explored. This study was to investigate the gut microbiota composition and function, fecal short-chain fatty acids (SCFA), intestinal permeability, and systemic inflammatory status of Duroc boar with high (H group, 100%) and low (L group, <80%) semen utilization rate. Fecal samples, analyzed by 16S ribosomal RNA gene sequencing, displayed taxonomic and functional changes between boars with high and low semen utilization rates. For the gut microbiota composition of the boars, four genera were different between the two groups. The [] and were enriched in L group boars, then negatively correlated with the semen utilization rate. While and were enhanced in the H group, only showed a significantly positive correlation with the semen utilization rate of boars. In addition, changes in the metabolic function of the gut microbiota of the two groups were found, including altered branched-chain fatty acid (BCFA) production. Significant increases in plasma endotoxin, zonulin, diamine oxidase, and lipocalin-2 levels were observed in boars with low semen utilization, and also, a similar trend in IL-6 and TNF-α was found. However, the concentration of IL-10 in plasma of boars with high semen utilization rate showed an increasing tendency. These results indicated increased intestinal permeability and systemic inflammation in boars with low semen utilization. Data showed that the composition and functions of gut microbiota varied between boars with high or low semen utilization rates, while the semen utilization rate is notably correlated with the gut microbiota composition, intestinal permeability, and inflammatory status of the boar.
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http://dx.doi.org/10.3389/fmicb.2020.581926DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7578402PMC
October 2020

[Success rate of one-stop procedure for atrial fibrillation ablation and its impact on cardiac function: a propensity-matched study].

Nan Fang Yi Ke Da Xue Xue Bao 2020 Oct;40(10):1415-1421

Department of Cardiovascular Diseases, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China.

Objective: To investigate the effect of the combination of atrial fibrillation (AF) ablation and left atrial appendage closure (LAAC) on cardiac function and the success rate of AF ablation.

Methods: We retrospectively analyzed the data of 56 patients with AF undergoing a one-stop procedure for AF ablation and LAAC in our hospital between May, 2015 and May, 2019. Propensity score matching (PSM) at the ratio of 1:1 was used to select 56 control patients undergoing AF ablation at high risk of stroke, for matching with the hybrid procedure group. The perioperative complications, thromboembolic events, recurrence of atrial arrhythmia and cardiac function were compared between the groups.

Results: The two groups of patients were comparable for age, gender, BMI, duration and type of AF, concomitant diseases, CHA2DS2-VASc and HAS-BLED scores ( > 0.05). The incidence of complications did not differ significantly between the hybrid procedure group and AF ablation group (17.9% 12.5%, =0.430). Compared with the control patients with AF ablation alone, the patients undergoing the hybrid procedure had a lowered incidence of thromboembolic events, but the difference was not statistically significant (1.8% 3.6%, =1.000). The hybrid procedure did not improve the success rate of AF ablation (OR: 1.338, 95%: 0.451-3.973, = 0.600) but significantly improved the cardiac function parameters including NT-pro BNP (945.3±1401.6 pg/mL 1520.7±2089.1 pg/mL, =0.010), LVEF[(60.8±7.0)% (58.6±7.8)%, =0.044], and left atrial diameter (43.9±7.5 mm 45.6±6.3 mm, =0.076); but the improvement of cardiac function was more obvious in the control patients undergoing AF ablation alone ( < 0.039).

Conclusions: The combination of AF ablation and LAAC is safe but does not improve the success rate of AF ablation. The one-stop procedure can improve cardiac function of the patients, but AF ablation alone can achieve better improvement of cardiac function.
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http://dx.doi.org/10.12122/j.issn.1673-4254.2020.10.06DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7606248PMC
October 2020

Effects of Dietary Lysine Levels on Production Performance and Milk Composition of High-Producing Sows during Lactation.

Animals (Basel) 2020 Oct 22;10(11). Epub 2020 Oct 22.

Department of Animal Nutrition and Feed Science, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.

Modern genotype sows require enhanced nutrition because of their larger body size and higher reproductive performance than 20 years ago. This study aimed to evaluate the effect of dietary Lys on the lactating of primiparous sows and the second lactating period to minimize sow body weight (BW) loss and maximize the survival rate of piglets and litter gain. A total of 160 primiparous Yorkshire sows were randomly allotted to one of four experimental lactation diets. Formulated to contain 0.84%, 0.94%, 1.04%, and 1.14% standardized ileal digestibility (SID) Lys and balanced in Met, Thr, Trp, and Val. No dietary effects were found on sow body weight (BW) and backfat thickness (BF) change and feed intake during lactation. However, the Lys intake ( = 0.04) of lactation increased linearly with increasing dietary Lys levels. In addition, 1.14% Lys for primiparous sow and 0.94% Lys for second parity sow during lactation increased the survival rate ( = 0.04), weight ( = 0.04), and ADG of piglets at d 21 ( = 0.03). The dietary Lys level did not affect colostrum compositions. However, the dry matter ( = 0.04) and protein ( = 0.03) in milk increased linearly with the increase in dietary Lys levels, whereas moisture decreased linearly ( = 0.05). The level of plasma urea nitrogen (PUN) also increased at d 21 of weaning ( = 0.04). These results indicate that high-yielding lactating sows required 1.14% SID Lys during parity 1, and 0.94% SID Lys during parity 2 to maximize the survival rate of piglets and litter gain, respectively. Moreover, the effects of dietary amino acid (AA) on the production performance of weaning pigs could be mediated through milk composition change.
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http://dx.doi.org/10.3390/ani10111947DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7690574PMC
October 2020

Surface Coordination of Multiple Ligands Endows N-Heterocyclic Carbene-Stabilized Gold Nanoclusters with High Robustness and Surface Reactivity.

Angew Chem Int Ed Engl 2021 Feb 15;60(7):3752-3758. Epub 2020 Dec 15.

State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, National & Local Joint Engineering Research Center for Preparation Technology of Nanomaterials, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China.

Deciphering the molecular pictures of the multi-component and non-periodic organic-inorganic interlayer is a grand technical challenge. Here we show that the atomic arrangement of hybrid surface ligands on metal nanoparticles can be precisely quantified through comprehensive characterization of a novel gold cluster, Au ( Pr -bimy) (PA) Br (1), which features three types of ligands, namely, carbene (1,3-diisopropylbenzimidazolin-2-ylidene, Pr -bimy), alkynyl (phenylacetylide, PA), and halide (Br), respectively. The delicately balanced stereochemical effects and bonding capabilities of the three ligands give rise to peculiar geometrical and electronic structures. Remarkably, despite its complex and highly distorted surface structure, cluster 1 exhibits unusual catalytic properties and yet it is highly stable, both chemically and thermally. Moreover, rich reactive sites on the cluster surface raise the prospect of bio-compatibility (as it can be functionalized to yield water-soluble derivatives) and bio-applications.
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http://dx.doi.org/10.1002/anie.202013718DOI Listing
February 2021

Surface coordination layer passivates oxidation of copper.

Nature 2020 10 14;586(7829):390-394. Epub 2020 Oct 14.

State Key Laboratory for Physical Chemistry of Solid Surfaces, iChEM, National & Local Joint Engineering Research Center of Preparation Technology of Nanomaterials, College of Chemistry and Chemical Engineering, Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen, China.

Owing to its high thermal and electrical conductivities, its ductility and its overall non-toxicity, copper is widely used in daily applications and in industry, particularly in anti-oxidation technologies. However, many widespread anti-oxidation techniques, such as alloying and electroplating, often degrade some physical properties (for example, thermal and electrical conductivities and colour) and introduce harmful elements such as chromium and nickel. Although efforts have been made to develop surface passivation technologies using organic molecules, inorganic materials or carbon-based materials as oxidation inhibitors, their large-scale application has had limited success. We have previously reported the solvothermal synthesis of highly air-stable copper nanosheets using formate as a reducing agent. Here we report that a solvothermal treatment of copper in the presence of sodium formate leads to crystallographic reconstruction of the copper surface and formation of an ultrathin surface coordination layer. We reveal that the surface modification does not affect the electrical or thermal conductivities of the bulk copper, but introduces high oxidation resistance in air, salt spray and alkaline conditions. We also develop a rapid room-temperature electrochemical synthesis protocol, with the resulting materials demonstrating similarly strong passivation performance. We further improve the oxidation resistance of the copper surfaces by introducing alkanethiol ligands to coordinate with steps or defect sites that are not protected by the passivation layer. We demonstrate that the mild treatment conditions make this technology applicable to the preparation of air-stable copper materials in different forms, including foils, nanowires, nanoparticles and bulk pastes. We expect that the technology developed in this work will help to expand the industrial applications of copper.
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http://dx.doi.org/10.1038/s41586-020-2783-xDOI Listing
October 2020