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66篇 您的检索式:作者名="Jing Shanshan"
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1Minimal invasive microscopic tooth preparation in esthetic restoration: a specialist consensus显示文摘By removing a part of the structure,the tooth preparation provides restorative space,bonding surface,and finish line for various restorations on abutment.Preparation technique plays critical role in achieving the optimal result of tooth preparation.With successful application of microscope in endodontics for>30 years,there is a full expectation of microscopic dentistry.However,as relatively little progress has been made in the application of microscopic dentistry in prosthodontics,the following assumptions have been proposed:Is it suitable to choose the tooth preparation technique under the naked eye in the microscopic vision?Is there a more accurate preparation technology intended for the microscope?To obtain long-term stable therapeutic effects,is it much easier to achieve maximum tooth preservation and retinal protection and maintain periodontal tissue and oral function health under microscopic vision?Whether the microscopic prosthodontics is a gimmick or a breakthrough in obtaining an ideal tooth preparation should be resolved in microscopic tooth preparation.This article attempts to illustrate the concept,core elements,and indications of microscopic minimally invasive tooth preparation,physiological basis of dental pulp,periodontium and functions involved in tool preparation,position ergonomics and visual basis for dentists,comparison of tooth preparation by naked eyes and a microscope,and comparison of different designs of microscopic minimally invasive tooth preparation techniques.Furthermore,a clinical protocol for microscopic minimally invasive tooth preparation based on target restorative space guide plate has been put forward and new insights on the quantity and shape of microscopic minimally invasive tooth preparation has been provided.Haiyang Yu Yuwei Zhao Junying Li Tian Luo Jing Gao Hongchen Liu Weicai Liu Feng Liu Ke Zhao Fei Liu Chufan Ma Juergen MSetz Shanshan Liang Lin Fan Shanshan Gao Zhuoli Zhu Jiefei Shen Jian Wang Zhimin Zhu Xuedong Zhou 2019International Journal of Oral Science2019,11,4:25
2Exposure to polycyclic aromatic hydrocarbons and risk for premature ovarian failure and reproductive hormones imbalance显示文摘Polycyclic aromatic hydrocarbons(PAHs)are a typical class of persistent organic pollutants that is ubiquitous worldwide.Previous animal studies suggested that PAHs had adverse effects on female reproduction.However,the human data regarding relationship of PAHs exposure with women reproductive health,such as ovarian dysfunction,are scarce.In this case-control study,the associations of serum levels of PAHs with the risk of premature ovarian failure(POF)and reproductive hormones in Chinese women were investigated,with recruiting 157 POF patients and 217 healthy women.The serum levels of 12 types of PAHs,as well as reproductive hormones,including follicle-stimulating hormone,luteinizing hormone and anti-mullerian hormone,were determined.In the logistic regression models,most individual PAH congeners showed significantly positive correlations with the risk of POF(p<0.05),except for fluorine and pyrene.Benzo(a)pyrene(BaP),as the most carcinogenic PAH congener,was observed to be significantly positively associated with the risk of POF.After adjustment for age,body mass index,educational levels and household income,per one-unit increase in the log-transformed BaP concentration was significantly correlated with 2.191-fold increased risk of POF(OR=2.191,95%CI:1.634-2.938,p<0.05).To the best of our knowledge,this is the first study to report an association between internal exposure levels of PAHs and the increased risk of POF in women.Xiaoqing Ye Wuye Pan Chunming Li Xiaochen Ma Shanshan Yin Jianhong Zhou Jing Liu 2020Journal of Environmental Sciences2020,32,5:10
3Single-cell transcriptomic atlas of primate cardiopulmonary aging显示文摘Aging is a major risk factor for many diseases,especially in highly prevalent cardiopulmonary comorbidities and infectious diseases including Coronavirus Disease 2019(COVID-19).Resolving cellular and molecular mechanisms associated with aging in higher mammals is therefore urgently needed.Here,we created young and old non-human primate single-nucleus/cell transcriptomic atlases of lung,heart and artery,the top tissues targeted by SARS-CoV-2.Analysis of cell type-specific aging-associated transcriptional changes revealed increased systemic inflammation and compromised virus defense as a hallmark of cardiopulmonary aging.With age,expression of the SARS-CoV-2 receptor angiotensin-converting enzyme 2(ACE2)was increased in the pulmonary alveolar epithelial barrier,cardiomyocytes,and vascular endothelial cells.We found that interleukin 7(IL7)accumulated in aged cardiopulmonary tissues and induced ACE2 expression in human vascular endothelial cells in an NF-κB-dependent manner.Furthermore,treatment with vitamin C blocked IL7-induced ACE2 expression.Altogether,our findings depict the first transcriptomic atlas of the aged primate cardiopulmonary system and provide vital insights into age-linked susceptibility to SARS-CoV-2,suggesting that geroprotective strategies may reduce COVID-19 severity in the elderly.Shuai Ma Shuhui Sun Jiaming Li Yanling Fan Jing Qu Liang Sun Si Wang Yiyuan Zhang Shanshan Yang Zunpeng Liu Zeming Wu Sheng Zhang Qiaoran Wang Aihua Zheng Shuguang Duo Yang Yu Juan Carlos Izpisua Belmonte Piu Chan Qi Zhou Moshi Song Weiqi Zhang Guang-Hui Liu 2021Cell Research2021,31,4:10
4Transcriptional activation and phosphorylation of OsCNGC9 confer enhanced chilling tolerance in rice显示文摘Low temperature is a major environmental factor that limits plant growth and productivity.Although transient elevation of cytoplasmic calcium has long been recognized as a critical signal for plant cold tolerance,the calcium channels responsible for this process have remained largely elusive.Here we report that OsCNGC9,a cyclic nucleotide-gated channel,positively regulates chilling tolerance by mediating cytoplasmic calcium elevation in rice(Oryza sativa).We showed that the loss-of-function mutant of OsCNGC9 is defective in cold-induced calcium influx and more sensitive to prolonged cold treatment,whereas OsCNGC9 overexpression confers enhanced cold tolerance.Mechanistically,we demonstrated that in response to chilling stress,OsSAPK8,a homolog of Arabidopsis thaliana OST1,phosphorylates and activates OsCNGC9 to trigger Ca2+influx.Moreover,we found that the transcription of OsCNGC9 is activated by a rice dehydration-responsive element-binding transcription factor,OsDREB1A.Taken together,our results suggest that OsCNGC9 enhances chilling tolerance in rice through regulating cold-induced calcium influx and cytoplasmic calcium elevation.Jiachang Wang Yulong Ren Xi Liu Sheng Luo Xiao Zhang Xin Liu Qibing Lin Shanshan Zhu Hua Wan Yang Yang Yu Zhang Bin Lei Chunlei Zhou Tian Pan Yongfei Wang Mingming Wu Ruonan jing Yang Xu Meng Han Fuqing Wu Cailin Lei Xiuping Guo Zhijun Cheng Xiaoming Zheng Yihua Wang Zhigang Zhao Ling Jiang Xin Zhang Yong-Fei Wang Haiyang Wang Jianmin Wan 2021Molecular Plant2021,14,2:10
5Isolation,purification,structural characteristic and antioxidative property of polysaccharides from A.cepa L.var.agrogatum Don显示文摘Allium cepa L.var.agrogatum Don(ALAP)is commonly consumed in China as well as other regions and has various beneficial health effects.A novel acidic polysaccharide(named ALAP-21)was obtained from ALAP by ultrasonic and microwave-assisted extraction and purification using DEAE-52 anion exchange and Sephadex G-100 columns.The monosaccharide composition,structural and antioxidative properties of ALAP-21 were investigated by GC–MS chromatography,FT-IR and NMR spectroscopies and three antioxidative activity tests in vitro.The results showed that ALAP-21 was a heteropolysaccharide composed of glucose,galacturonic acid,mannose,galactose,arabinose,rhamnose,xylose,fructose and glucuronic acid with a relative molar ratio of 26.282:27.546:11.400:4.781:2.467:2.445:3.622:1.106:1.753,owning(1→4)-β-d-Glcp,(1→4)-β-d-GalAp6Me3OA,(1→4)-β-d-Galp6OMe,(1→2)-β-l-Rhap,(1→4)-β-d-Manp glycosidic linkages.(1→4)-β-d-Glcp and(1→4)-β-d-GalAp6Me3OA residues might be the main components of the sugar chain backbone of ALAP-21.Furthermore,ALAP-21 exhibited high potential for DPPH radicals(82.02%),hydroxyl radicals(53.33%)and superoxide anion radicals(50.28%).These results provide a reference for further research and rational development of ALAP polysaccharides.Hongcheng Liu Hongxiu Fan Jing Zhang Shanshan Zhang Wenting Zhao Tingting Liu Dawei Wang 2020Food Science and Human Wellness2020,9,1:10
6Development and validation of an endoscopic images-based deep learning model for detection with nasopharyngeal malignancies显示文摘Background:Due to the occult anatomic location of the nasopharynx and frequent presence of adenoid hyperpla-sia,the positive rate for malignancy identification during biopsy is low,thus leading to delayed or missed diagnosis for nasopharyngeal malignancies upon initial attempt.Here,we aimed to develop an artificial intelligence tool to detect nasopharyngeal malignancies under endoscopic examination based on deep learning.Methods:An endoscopic images-based nasopharyngeal malignancy detection model(eNPM-DM)consisting of a fully convolutional network based on the inception architecture was developed and fine-tuned using separate training and validation sets for both classification and segmentation.Briefly,a total of 28,966 qualified images were collected.Among these images,27,536 biopsy-proven images from 7951 individuals obtained from January 1st,2008,to December 31st,2016,were split into the training,validation and test sets at a ratio of 7:1:2 using simple randomiza-tion.Additionally,1430 images obtained from January 1st,2017,to March 31st,2017,were used as a prospective test set to compare the performance of the established model against oncologist evaluation.The dice similarity coef-ficient(DSC)was used to evaluate the efficiency of eNPM-DM in automatic segmentation of malignant area from the background of nasopharyngeal endoscopic images,by comparing automatic segmentation with manual segmenta-tion performed by the experts.Results:All images were histopathologically confirmed,and included 5713(19.7%)normal control,19,107(66.0%)nasopharyngeal carcinoma(NPC),335(1.2%)NPC and 3811(13.2%)benign diseases.The eNPM-DM attained an overall accuracy of 88.7%(95%confidence interval(CI)87.8%-89.5%)in detecting malignancies in the test set.In the prospective comparison phase,eNPM-DM outperformed the experts:the overall accuracy was 88.0%(95%CI 86.1%-89.6%)vs.80.5%(95%CI 77.0%-84.0%).The eNPM-DM required less time(40 s vs.110.0±5.8 min)and exhibited encouraging performance in automatic segmentation of nasopharyngeal malignant area from the background,with an average DSC of 0.78±0.24 and 0.75±0.26 in the test and prospective test sets,respectively.Conclusions:The eNPM-DM outperformed oncologist evaluation in diagnostic classification of nasopharyngeal mass into benign versus malignant,and realized automatic segmentation of malignant area from the background of nasopharyngeal endoscopic images.Chaofeng Li Bingzhong Jing Liangru Ke Bin Li Weixiong Xia Caisheng He Chaonan Qian Chong Zhao Haiqiang Mai Mingyuan Chen Kajia Cao Haoyuan Mo Ling Guo Qiuyan Chen Linquan Tang Wenze Qiu Yahui Yu Hu Liang Xinjun Huang Guoying Liu Wangzhong Li Lin Wang Rui Sun Xiong Zou Shanshan Guo Peiyu Huang Donghua Luo Fang Qiu Yishan Wu Yijun Hua Kuiyuan Liu Shuhui Lv Jingjing Miao Yanqun Xiang Ying Sun Xiang Guo Xing Lv 2018Cancer Communications2018,38,1:9
7Heat shock protein 90 promotes RNA helicase DDX5 accumulation and exacerbates hepatocellular carcinoma by inhibiting autophagy显示文摘Objective:Hepatocellular carcinoma(HCC),the main type of liver cancer,has a high morbidity and mortality,and a poor prognosis.RNA helicase DDX5,which acts as a transcriptional co-regulator,is overexpressed in most malignant tumors and promotes cancer cell growth.Heat shock protein 90(HSP90)is an important molecular chaperone in the conformational maturation and stabilization of numerous proteins involved in cell growth or survival.Methods:DDX5 m RNA and protein expression in surgically resected HCC tissues from 24 Asian patients were detected by quantitative real-time PCR and Western blot,respectively.The interaction of DDX5-HSP90 was determined by molecular docking,immunoprecipitation,and laser scanning confocal microscopy.The autophagy signal was detected by Western blot.The cell functions and signaling pathways of DDX5 were determined in 2 HCC cell lines.Two different murine HCC xenograft models were used to determine the function of DDX5 and the therapeutic effect of an HSP90 inhibitor.Results:HSP90 interacted directly with DDX5 and inhibited DDX5 protein degradation in the AMPK/ULK1-regulated autophagy pathway.The subsequent accumulation of DDX5 protein induced the malignant phenotype of HCC by activating theβ-catenin signaling pathway.The silencing of DDX5 or treatment with HSP90 inhibitor both blocked in vivo tumor growth in a murine HCC xenograft model.High levels of HSP90 and DDX5 protein were associated with poor prognoses.Conclusions:HSP90 interacted with DDX5 protein and subsequently protected DDX5 protein from AMPK/ULK1-regulated autophagic degradation.DDX5 and HSP90 are therefore potential therapeutic targets for HCC.Ting Zhang Xinrui Yang Wanping Xu Jing Wang Dawei Wu Zhixian Hong Shengxian Yuan Zhen Zeng Xiaodong Jia Shanshan Lu Rifaat Safadi Sen Han Zhihong Yang Leonard M.Neckers Suthat Liangpunsakul Weiping Zhou Yinying Lu 2021Cancer Biology & Medicine2021,18,3:7
8Ultrasound-triggered noninvasive regulation of blood glucose levels using microgels integrated with insulin nanocapsules显示文摘Diabetes is a serious public health problem affecting 422 million people worldwide. Traditional diabetes management often requires multiple daily insulin injections, associated with pain and inadequate glycemia control. Herein, we have developed an ultrasound-triggered insulin delivery system capable of pulsatile insulin release that can provide both long-term sustained and fast on-demand responses. In this system, insulin-loaded poly(lactic-co-glycolic acid) (PLGA) nanocapsules are encapsulated within chitosan microgels. The encapsulated insulin in nanocapsules can passively diffuse from the nanoparticle but remain restricted within the microgel. Upon ultrasound treatment, the stored insulin in microgels can be rapidly released to regulate blood glucose levels. In a chemically-induced type 1 diabetic mouse model, we demonstrated that this system, when activated by 30 s ultrasound administration, could effectively achieve glycemic control for up to one week in a noninvasive, localized, and pulsatile manner.Jin Di Jicheng Yu Qun Wang Shanshan Yao Yanqi Ye Matthew Pless Yong Zhu Yun Jing Zhen Gu 2017Nano Research2017,10,4:6
9Extensive profiling of the expressions of tRNAs and tRNA-derived fragments(tRFs)reveals the complexities of tRNA and tRF populations in plants显示文摘Evidence is emerging that t RNA-derived fragments(t RFs)are regulatory molecules.Studies of t RFs in plants have been based on conventional small RNA sequencing,and focused on profiling of t RF-5 and t RF-3 species.A more comprehensive and quantitative analysis of the entire t RF population is highly necessary.Here,we employ t RNA-seq and YAMAT-seq,and develop a bioinformatics tool to comprehensively profile the expressions of t RNAs and t RFs in plants.We show that in Arabidopsis,approximately half of t RNA genes are extremely weakly expressed,accounting for only 1%of total t RNA abundance,while~12%of t RNA genes contribute to~80%of t RNA abundance.Our t RNA sequencings in various plants reveal that t RNA expression profiles exhibit a cross-species conserved pattern.By characterizing the composition of a highly heterogeneous t RF population,we show that t RNA halves and previously unnoticed 10–16-nt tiny t RFs represent substantial portions.The highly accumulated 13-nt and 16-nt tiny t RFs in Arabidopsis indicate that tiny t RFs are not random t RNA degradation products.Finally,we provide a user-friendly database for displaying the dynamic spatiotemporal expressions of t RNAs and t RFs in the model plants Arabidopsis and rice.Xuan Ma Chunyan Liu Xiaocong Kong Jing Liu Siju Zhang Shanshan Liang Weijiang Luan Xiaofeng Cao 2021Science China(Life Sciences)2021,64,4:5
10A Total of 2,657 Reported Cases and 14 Deaths Due to Hemorrhagic Fever with Renal Syndrome—Shaanxi Province,China,January 1–December 19,2021显示文摘Hemorrhagic fever with renal syndrome(HFRS)is a group of illnesses that are caused by hantaviruses.Although increased exposure to rodents or their urine and droppings could be a decisive factor of the increasing in incidence,further research is still needed to elucidate the causes of the epidemic(1).Since October 2021,the number of reported cases of HFRS has been increasing rapidly in Shaanxi Province.As of December 19,2021,a total of 2,657 cases were reported with 14 deaths.Jing Wei Xiaoxia Huang Shen Li Shanshan Du Pengbo Yu Jiandong Li 2021China CDC weekly2021,3,53:5
11MATRIEX imaging:multiarea two-photon real-time in vivo explorer显示文摘Two-photon laser scanning microscopy has been extensively applied to study in vivo neuronal activity at cellular and subcellular resolutions in mammalian brains.However,the extent of such studies is typically confined to a single functional region of the brain.Here,we demonstrate a novel technique,termed the multiarea two-photon real-time in vivo explorer(MATRIEX),that allows the user to target multiple functional brain regions distributed within a zone of up to 12mm in diameter,each with a field of view(FOV)of ~200μm in diameter,thus performing two-photon Ca2+imaging with single-cell resolution in all of the regions simultaneously.For example,we demonstrate real-time functional imaging of single-neuron activities in the primary visual cortex,primary motor cortex and hippocampal CA1 region of mice in both anesthetized and awake states.A unique advantage of the MATRIEX technique is the configuration of multiple microscopic FOVs that are distributed in three-dimensional space over macroscopic distances(>1 mm)both laterally and axially but that are imaged by a single conventional laser scanning device.In particular,the MATRIEX technique can be effectively implemented as an add-on optical module for an existing conventional single-beam-scanning two-photon microscope without requiring any modification to the microscope itself.Thus,the MATRIEX technique can be readily applied to substantially facilitate the exploration of multiarea neuronal activity in vivo for studies of brain-wide neural circuit function with single-cell resolution.Mengke Yang Zhenqiao Zhou Jianxiong Zhang Shanshan Jia Tong Li Jiangheng Guan Xiang Liao Bing Leng Jing Lyu Kuan Zhang Min Li Yan Gong Zhiming Zhu Junan Yan Yi Zhou Jian K Liu Zsuzsanna Varga Arthur Konnerth Yuguo Tang Jinsong Gao Xiaowei Chen Hongbo Jia 2019Light(Science & Applications)2019,8,1:4
12Prussian blue nanoparticle-loaded microbubbles for photothermally enhanced gene delivery through ultrasound-targeted microbubble destruction显示文摘By adsorbing chitosan(CS)-functionalized Prussian blue(PB) nanoparticles(CS/PB NPs) complexing DNA onto the surface of gas encapsulated microbubbles(MBs), a multifunctional gene delivery system of MBs@CS/PB/DNA was fabricated for photothermally enhanced gene transfection through ultrasound-targeted microbubble destruction. CS/PB NPs of(2.69 ± 0.49) nm could complex DNA effectively when the mass ratio was2:1. It was found that MBs@CS/PB/DNA could enhance ultrasound imaging greatly both in vitro and in vivo. In addition, MBs@CS/PB/DNA could be disrupted by applying a higher-intensity ultrasound irradiation to release CS/PB/DNA, which could effectively transform the nearinfrared(NIR) light into heat to assist the uptake of CS/PB/DNA by cells. With the aid of ultrasound irradiation and NIR light irradiation, the gene transfection efficiency was significantly enhanced to(43.08 ± 1.13) %, much higher than polyethylenimine. Moreover, MBs@CS/PB/DNA showed excellent biocompatibility, encouraging the further exploration of MBs@CS/PB/DNA to be a platform for combined ultrasound image, photothermal therapy, drug delivery, and gene therapy.Xiaoda Li Xiuli Yue Jinrui Wang Xiaolong Liang Lijia Jing Li Lin Yongbo Yang Shanshan Feng Yajun Qian Zhifei Dai 2016Science Bulletin2016,61,2:4
13Sulforaphane protects primary cultures of cortical neurons against injury induced by oxygen-glucose deprivation/reoxygenation via anti-apoptosis显示文摘Objective To determine whether sulforaphane (SFN) protects neurons against injury caused by oxygen-glucose deprivation/reoxygenation (OGD/R) and, if so, to investigate the possible mechanisms. Methods Primary cultures of neurons were prepared from the cerebral cortex of 1-day-old Sprague-Dawley rats. On days 5-6 in vitro, the neurons were exposed to OGD for 1 h, followed by reoxygenation for 24 h. Cells were treated with 0, 0.1, 0.2, 0.5, 1, 2.5, or 5 μmol/L SFN, with or without 10 μmol/L LY294002, a PI3K-specific inhibitor, during OGD/R (a total of 25 h). After 24-h reoxygenation, MTT was used to assess viability and injury was assessed by Hoechst 33258/propidium iodide (PI) staining; immunofluorescence staining and Western blot were performed to detect molecular events associated with apoptosis. Results The MTT assay showed that 1 μmol/L SFN significantly increased viability, and Hoechst 33258/PI staining showed that the numbers of injured neurons were reduced significantly in the SFN group. Furthermore, immunofluorescence staining and Western blot showed that SFN increased Bcl-2 and decreased cleaved caspase-3 levels. Moreover, LY294002 inhibited the phosphorylated-Akt expression evoked by SFN, decreased Bcl-2 expression and increased cleaved caspase-3 expression. Conclusion SFN protects neurons against injury from OGD/R and this effect may be partly associated with an anti-apoptosis pathway.Xuemei Wu Jing Zhao Shanshan Yu Yanlin Chen , Jingxian Wu Yong Zhao 2012Neuroscience Bulletin2012,28,5:4
14Dynamic cell transition and immune response landscapes of axolotl limb regeneration revealed by single-cell analysis显示文摘Dear Editor,The axolotl,Ambystoma mexicanum,has extraordinary capability to fully recover multiple tissues after lost,whereas such capability has disappeared in mammals.Thus,deci-phering detailed mechanisms underlying axolotl regenera-tion could provide valuable lessons for regenerative medicine.However,many questions,such as the origin of essential progenitor cells and key responses of individual types of cells for regeneration remain elusive(Haas and Whited,2017).Newly developed single-cell RNA sequenc-ing(scRNA-seq)method enables researchers to observe cellular and molecular dynamics in axolotl regeneration at the single-cell resolution(Gerber et al.,2018;Leigh et al.,2018),but the reported transcriptome landscapes are only for certain cell types or in certain regenerative stages.A complete overview of the regeneration process for all cell types is still lacking.Hanbo Li Xiaoyu Wei Li Zhou Weiqi Zhang Chen Wang Yang Guo Denghui Li Jjianyang Chen Tianbin Liu Yingying Zhang Shuai Ma Congyan Wang Fujian Tan Jiangshan Xu Yang Liu Yue Yuan Liang Chen Qiaoran Wang Jing Qu Yue Shen Shanshan Liu Guangyi Fan Longqi Liu Xin Liu Yong Hou Guang-Hui Liu Ying Gu Xun Xu 2021Protein & Cell2021,12,1:3
15A New Global Solar-induced Chlorophyll Fluorescence(SIF)Data Product from TanSat Measurements显示文摘The Chinese Carbon Dioxide Observation Satellite Mission(TanSat)is the third satellite for global CO2 monitoring and is capable of detecting weak solar-induced chlorophyll fluorescence(SIF)signals with its advanced technical characteristics.Based on the Institute of Atmospheric Physics Carbon Dioxide Retrieval Algorithm for Satellite Remote Sensing(IAPCAS)platform,we successfully retrieved the TanSat global SIF product spanning the period of March 2017 to February 2018 with a physically based algorithm.This paper introduces the new TanSat SIF dataset and shows the global seasonal SIF maps.A brief comparison between the IAPCAS TanSat SIF product and the data-driven SVD(singular value decomposition)SIF product is also performed for follow-up algorithm optimization.The comparative results show that there are regional biases between the two SIF datasets and the linear correlations between them are above 0.73 for all seasons.The future SIF data product applications and requirements for SIF space observation are discussed.Lu YAO Dongxu YANG Yi LIU Jing WANG Liangyun LIU Shanshan DU Zhaonan CAI Naimeng LU Daren LYU Maohua WANG Zengshan YIN 2021Advances in Atmospheric Sciences2021,38,3:3
16Response of grease film at low speeds under pure rolling reciprocating motion显示文摘Using an optical interferometric technique,the grease film distribution under a pure rolling reciprocating motion is observed on a ball‐disk test rig,to explore the transient response of grease,which is expected to fill the contact with thickener fiber and run for a long time under steady‐state conditions.It is found that the reciprocating motion reduces the accumulation of the thickener fiber gradually with time.The maximum film thickness forms around the stroke ends.After 1,000 working cycles,very severe starvation occurs so that either the central or minimum film thickness becomes nearly constant over one working period.Thus,the life of grease lubrication under a transient condition is far below that under steady‐state conditions.However,it is also found that by selecting a smaller stroke length,the thickener fiber spreads out in the contact instead of being removed from the contact at the 1,000th working period.When increasing the maximum entraining speed of the reciprocating motion to a certain value,during which the thickener fiber is not expected to accumulate under a steady‐state condition,severe starvation occurs very quickly,causing surface damage.Yiming HAN Jing WANG Shanshan WANG Qian ZOU Gary BARBER 2020Friction2020,8,1:3
17Mouse knockout models reveal largely dispensable but context-dependent functions of IncRNAs during development显示文摘Xue Han Sai Luo Guangdun Peng Yuyang Lu Guizhong Cui Lichao Liu Pixi Yan Yafei Yin Wei Liu Ran Wang Jiejie Zhang Shanshan Ai Zai Chang Jie Na Aibin He Naihe Jing Xiaohua Shen 2018Journal of Molecular Cell Biology2018,10,2:3
18Enhancement of α-ketoisovalerate production by relieving the product inhibition of L-amino acid deaminase from Proteus mirabilis显示文摘L-Amino acid deaminase(LAAD) is a key enzyme in the deamination of L-valine(L-val) to produce α-ketoisovalerate(KIV). However, the product inhibition of LAAD is a major hindrance to industrial KIV production.In the present study, a combination strategy of modification of flexible loop regions around the product binding site and the avoidance of dramatic change of main-chain dynamics was reported to reduce the product inhibition.The four mutant PM-LAAD^(M4)(PM-LAAD^(S98A/T105A/S106A/L341A)) achieved a 6.2-fold higher catalytic efficiency and an almost 6.7-fold reduction in product inhibition than the wild-type enzyme. Docking experiments suggested that weakened interactions between the product and enzyme, and the flexibility of the 'lid' structure relieved LAAD product inhibition. Finally, the whole-cell biocatalyst PM-LAAD^(M4) has been applied to KIV production,the titer and conversion rate of KIV from L-val were 98.5 g·L^-1 and 99.2% at a 3-L scale, respectively. These results demonstrate that the newly engineered catalyst can significantly reduce the product inhibition, that making KIV a prospective product by bioconversion method, and also provide the understanding of the mechanism of the relieved product inhibition of PM-LAAD.Shanshan Pei Xiaobo Ruan Jia Liu Wei Song Xiulai Chen Qiuling Luo Liming Liu Jing Wu 2020Chinese Journal of Chemical Engineering2020,28,8:2
19Leach: an automatic learning cache for inline primary deduplication system显示文摘Bin LIN Shanshan LI Xiangke LIAO Jing ZHANG Xiaodong LIU 2014Frontiers of Computer Science2014,8,2:2
20Novel human H7N9 influenza virus in China显示文摘Outbreaks of H7N9 avian influenza in humans in 5 provinces and 2 municipalities of China have reawakened concern that avian influenza viruses may again cross species barriers to infect the human population and thereby initiate a new influenza pandemic.Evolutionary analysis shows that human H7N9 influenza viruses originated from the H9N2,H7N3 and H11N9 avian viruses,and that it is as a novel reassortment influenza virus.This ar­ticle reviews current knowledge on 11 subtypes of influenza A virus from human which can cause human infec­tions.Chengmin WANG Jing LUO Jing WANG Wen SU Shanshan GAO Min ZHANG Li XIE Hua DING Shelan LIU Xiaodong LIU Yu CHEN Yaxiong JIA Hongxuan HE 2014Integrative Zoology2014,9,3:2
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