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| 1 | Prevalence of Autism Spectrum Disorder in China:A Nationwide Multi-center Population-based Study Among Children Aged 6 to 12 Years显示文摘This study aimed to obtain the first national estimate of the prevalence of autism spectrum disorder(ASD) in Chinese children.We targeted the population of 6 to 12-year-old children for this prevalence study by multistage convenient cluster sampling.The Modified Chinese Autism Spectrum Rating Scale was used for the screening process.Of the target population of 142,086 children,88.5%(n=125,806) participated in the study.A total of 363 children were confirmed as having ASD.The observed ASD prevalence rate was 0.29%(95% CI:0.26%-0.32%) for the overall population.After adjustment for response rates,the estimated number of ASD cases was867 in the target population sample,thereby achieving an estimated prevalence of 0.70%(95% CI:0.64%-0.74%).The prevalence was significantly higher in boys than in girls(0.95%;95% CI:0.87%-1.02% versus 0.30%;95%CI:0.26%-0.34%;P <0.001).Of the 363 confirmed ASD cases,43.3% were newly diagnosed,and most of those(90.4%) were attending regular schools,and 68.8% of the children with ASD had at least one neuropsychiatric comorbidity.Our findings provide reliable data on the estimated ASD prevalence and comorbidities in Chinese children. | Hao Zhou Xiu Xu Weili Yan Xiaobing Zou Lijie Wu Xuerong Luo Tingyu Li Yi Huang Hongyan Guan Xiang Chen Meng Mao Kun Xia Lan Zhang Erzhen Li Xiaoling Ge Lili Zhang Chunpei Li Xudong Zhang Yuanfeng Zhou Ding Ding Andy Shih Eric Fombonne Yi Zheng Jisheng Han Zhongsheng Sun Yong-hui Jiang Yi Wang LATENT-NHC Study Team | 2020 | Neuroscience Bulletin2020,36,9: | 158 |
| 2 | TALEN or Cas9-Rapid,Efficient and Specific Choices for Genome Modifications显示文摘Precise modifications of complex genomes at the single nucleotide level have been one of the big goals for scientists working in basic and applied genetics,including biotechnology,drug development,gene therapy and synthetic biology.However,the relevant techniques for making these manipulations in model organisms and human cells have been lagging behind the rapid high throughput studies in the post-genomic era with a bottleneck of low efficiency,time consuming and laborious manipulation,and off-targeting problems.Recent discoveries of TALEs(transcription activator-like effectors) coding system and CRISPR(clusters of regularly interspaced short palindromic repeats) immune system in bacteria have enabled the development of customized TALENs(transcription activator-like effector nucleases) and CRISPR/Cas9 to rapidly edit genomic DNA in a variety of cell types,including human cells,and different model organisms at a very high efficiency and specificity.In this review,we first briefly summarize the development and applications of TALENs and CRISPR/Cas9-mediated genome editing technologies;compare the advantages and constraints of each method;particularly,discuss the expected applications of both techniques in the field of site-specific genome modification and stem cell based gene therapy;finally, propose the future directions and perspectives for readers to make the choices. | Chuanxian Wei Jiyong Liu Zhongsheng Yu Bo Zhang Guanjun Gao Renjie Jiao | 2013 | Journal of Genetics and Genomics2013,40,6: | 52 |
| 3 | Efficient and Specific Modifications of the Drosophila Genome by Means of an Easy TALEN Strategy显示文摘技术开发总是是在生物医学的研究驾驶突破的力量之一。自从托马斯·摩根的时间起,一步一步地, Drosophilists 为操作并且机能上地把开发了强大的基因工具为改进这些技术并且开发新技术的果蝇染色体,而是房间仍然大,今天特别作为生物学家开始系统地学习不同模型有机体的功能的 genomics ,包括人,以一种高产量的方式。这里,我们报导,第一次在果蝇,为借助于改进抄写在很高的效率修改果蝇染色体的一个快速、容易、高度特定的方法像使活跃之物的受动器核酸酶(TALEN ) 策略。我们利用了最近发达的单位集会策略装配设计修改黄基因的二特定的 TALEN (在性染色体上) 并且新奇正染色体的基因。TALEN 的 mRNAs 随后被注入果蝇胚胎。从 31.2% 注射 F0 肥沃的苍蝇,我们检测了包含黄基因的可继承的修正。从到可继承的修正的察觉的特定的 TALEN 的建设的全部过程能在一个月以内被完成。在果蝇的这个调停 TALEN 的染色体修正方法的潜在的应用程序被讨论。 | Jiyong Liu Changqing Li Zhongsheng Yu Peng Huang Honggang Wu Chuanxian Wei Nannan Zhu Yan Shen Yixu Chen Bo Zhang Wu-Min Deng Renjie Jiao | 2012 | Journal of Genetics and Genomics2012,39,5: | 43 |
| 4 | Single-Cell Sequencing Technologies: Current and Future显示文摘Intensively developed in the last few years, single-cell sequencing technologies now present numerous advantages over traditional sequencing methods for solving the problems of biological heterogeneity and low quantities of available biological materials. The application of single-cell sequencing technologies has profoundly changed our understanding of a series of biological phenomena,including gene transcription, embryo development, and carcinogenesis. However, before single-cell sequencing technologies can be used extensively, researchers face the serious challenge of overcoming inherent issues of high amplification bias, low accuracy and reproducibility. Here, we simply summarize the techniques used for single-cell isolation, and review the current technologies used in single-cell genomic, transcriptomic, and epigenomic sequencing. We discuss the merits, defects, and scope of application of single-cell sequencing technologies and then speculate on the direction of future developments. | Jialong Liang Wanshi Cai Zhongsheng Sun | 2014 | Journal of Genetics and Genomics2014,41,10: | 20 |
| 5 | Effects of Forest Gaps on Some Microclimate Variables in Castanopsis kawakamii Natural Forest显示文摘The objective of this study was to understand the effects of forest gap and variations in different seasons, gap size, locations and diurnal variations on forest microclimate and soil water content. Spatial and temporal distribution features of air temperature (TA ), soil temperature (TS ), relative humidity (h) and soil water content (Ψ) were measured in Castanopsis kawakamii natural forest gaps created by a severe typhoon or fallen dead trees. The results showed that: (1) the variations of TA , h, and TS in four seasons were extremely significant. The variations of Ψ in four seasons were extremely significant except for those between spring and summer. (2) The diurnal variations of TA and T S were expressed with a single peak curve. The diurnal variations of h and Ψ presented a high-low-high trend. (3) The variations of TA , h, and TS were extremely significant among the large, medium and small gaps in C. kawakamii natural forest. Medium gaps had the highest TA and the lowest h while small gaps were just contrary to medium gaps. The variations of Ψ were extremely significant for large, medium and small gaps except those between the medium and large gaps. (4) The TA , h, TS and Ψ were decreased from the gap center, canopy gap, expanded gap to understory. These results will help further our understanding of the abiotic and consequent biotic responses to gaps in the mid-subtropical broadleaved forests, which also provide a theoretical basis for the scientific management and population restoration of C. kawakamii natural forest. | HE Zhongsheng LIU Jinfu WU Caiting ZHENG Shiqun HONG Wei SU Songjin WU Chengzhen | 2012 | Journal of Mountain Science2012,9,5: | 17 |
| 6 | 激光拉曼技术评价沉积有机质热成熟度显示文摘在澳大利亚联邦科学与工业研究组织能源组对激光拉曼技术评价有机质成熟度研究成果RaMM(1)和RaMM(2)的基础上,提出了可以评价沉积有机质热成熟度的激光拉曼技术新模型RaMM(P),模型使用范围为0.4% | 王民 Li Zhongsheng | 2016 | 石油学报2016,37,9: | 17 |
| 7 | Variations of temperature and precipitation of snowmelt period and its effect on runoff in the mountainous areas of Northwest China显示文摘在西北中国的干旱陆地的水资源主要源于雪和冰河在多山的区域融化水。snowmelt 时期的发作,停止,长度,温度和降水上的学习因此具有为相当分配有限的水资源并且采取科学的水资源管理措施的大意义。用从在时期上的 8 个多山的气象站的每日的吝啬的温度和降水 19602010 在西北中国的干旱陆地,这份报纸分析 snowmelt 时期和它的空间变化的气候变化并且探索流量的敏感到 snowmelt 的长度,温度和降水时期。结果证明当吝啬的结束日期 9.19 天以后移动了时, snowmelt 时期的那吝啬的发作 15.33 天早变了。当那仅仅 10.16 天早在北 Qilian 山移动了时,在南部的 Tianshan 山的 snowmelt 时期的发作 20.01 天早移动了。吝啬的降水和空气温度由 47.3 公里增加了并且 0. | LI Baofu CHEN Yaning CHEN Zhongsheng LI Weihong ZHANG Baohuan | 2013 | Journal of Geographical Sciences2013,23,1: | 14 |
| 8 | PGC-1α induces apoptosis in human epithelial ovarian cancer cells through a PPARy-dependent pathway显示文摘Peroxisome 激活 proliferator 的受体鲸鱼群妈(PPAR γ) coactivator-1 高山哈(PGC-1 α) coactivates 多重抄写因素并且调整几个代谢过程。Thecurrent 学习在人的上皮的卵巢的癌症房间在 apoptosis 的正式就职调查了 PGC-1 α的角色。在人的卵巢和人的卵巢的上皮的肿瘤之间的 PGC-1 α信使 rna 水平被量的 RT-PCR 检验。更少的 PGC-1 α表示与正常卵巢相比在恶意的肿瘤的表面上皮被发现。在人的上皮的卵巢的癌症房间线 Ho-8910 的 PGC-1 α的 Overexpression 通过 Bcl-2 和 Bax 表示的协调规定导致了房间 apoptosis。Microarray 分析证实 PGC-1 α戏剧性地在 Ho-8910 房间影响了 apoptosis 相关的基因。 Mitochondrial 功能的试金证明 apoptosis 的正式就职通过由细胞色素 c.Furthermore 的版本的终端阶段,导致的 apoptosis 部分是,然而并非完全,由 PPAR γa ntagonist ( GW9662 )堵住了的 PGC-1 α-,并且由 siRNA 的 PPAR γ 表示的抑制也在 Ho-8910 房间禁止了 PGC-1 α- inducedapoptosis 。这些数据建议 PGC-1 α通过 aPPAR γ - 依赖者小径施加了它的效果。我们的调查结果显示 PGC-1 α涉及 apoptotic signaltransduction 小径, PGC-1 α的 down 规定可以是在支持上皮的卵巢的癌症生长和前进的一个关键点。 | Yan Zhang Yi Ba Chang Liu Guoxun Sun Li Ding Songyuan Gao Jihui Hao Zhentao Yu Junfeng Zhang Ke Zen Zhongsheng Tong Yang Xiang Chen-Yu Zhang | 2007 | Cell Research2007,17,4: | 14 |
| 9 | Interpretation of breast cancer screening guideline for Chinese women显示文摘Breast cancer is the most common malignant tumor in Chinese women.Early screening is the best way to improve the rates of early diagnosis and survival of breast cancer patients.The peak onset age for breast cancer in Chinese women is considerably younger than those in European and American women.It is imperative to develop breast cancer screening guideline that is suitable for Chinese women.By summarizing the current evidence on breast cancer screening in Chinese women,and referring to the latest guidelines and consensus on breast cancer screening in Europe,the United States,and East Asia,the China Anti-Cancer Association and National Clinical Research Center for Cancer(Tianjin Medical University Cancer Institute and Hospital)have formulated population-based guideline for breast cancer screening in Chinese women.The guideline provides recommendations on breast cancer screening for Chinese women at average or high risk of breast cancer according to the following three aspects:age of screening,screening methods,and screening interval.This article provides more detailed information to support the recommendations in this guideline and to provide more direction for current breast cancer screening practices in China. | Yubei Huang Zhongsheng Tong Kexin Chen Ying Wang Peifang Liu Lin Gu Juntian Liu Jinpu Yu Fengju Song Wenhua Zhao Yehui Shi Hui Li Huaiyuan Xiao Xishan Hao | 2019 | Cancer Biology & Medicine2019,16,4: | 10 |
| 10 | Scaling of Soil Carbon,Nitrogen,Phosphorus and C:N:P Ratio Patterns in Peatlands of China显示文摘Inspired by the importance of Redfield-type C:N:P ratios in global soils,we looked for analogous patterns in peatlands and aimed at deciphering the potential affecting factors.By analyzing a suite of peatlands soil data(n = 1031),mean soil organic carbon(SOC),total nitrogen(TN) and total phosphorous(TP) contents were 50.51%,1.45% and 0.13%,respectively,while average C:N,C:P and N:P ratios were 26.72,1186.00 and 46.58,respectively.C:N ratios showed smaller variations across different vegetation coverage and had less spatial heterogeneity than C:P and N:P ratios.No consistent C:N:P ratio,though with a general value of 1245:47:1,was found for entire peatland soils in China.The Northeast China,Tibet,Zoigê Plateau and parts of Xinjiang had high soil SOC,TN,TP,and C:P ratio.Qinghai,parts of the lower reaches of the Yangtze River,and the coast zones have low TP and N:P ratio.Significant differences for SOC,TN,TP,C:N,C:P and N:P ratios were observed across groups categorized by predominant vegetation.Moisture,temperature and precipitation all closely related to SOC,TN,TP and their pairwise ratios.The hydrothermal coefficient(RH),defined as annual average precipitation divided by temperature,positively and significantly related to C:N,C:P and N:P ratios,implying that ongoing climate change may prejudice peatlands as carbon sinks during the past 50 years in China. | ZHANG Zhongsheng XUE Zhenshan LYU Xianguo TONG Shouzheng JIANG Ming | 2017 | Chinese Geographical Science2017,27,4: | 9 |
| 11 | Response of runoff to change of atmospheric 0℃ level height in summer in arid region of Northwest China显示文摘Based on the daily observed data from eight sounding stations and the daily mountain runoff data from nine rivers in summer from 1960 to 2009 in four typical study areas located in arid region of Northwest China(ARNC),the change trends,abrupt change points,and their significance of runoff and 0℃ level height(FLH) were analyzed in ARNC in the last 50 years by using Mann-Kendall(MK) nonparametric test,and the quantitative relationship between runoff and FLH in summer was also analyzed with the linear regression and elastic coefficient methods.The results are indicated as follows:(1) in recent 50 years,there is a similar changing trend between the summer runoff and FLH in ARNC and each region has its own unique feature.The summer runoff has been significantly ascending in the Tianshan Mountains and on the northern slope of the Qilian Mountains(NSQM) compared to that of the northern slope of the Kunlun Mountains(NSKM).Likewise,the FLH has been taking on a markedly rising trend on the northern slopes of the Tianshan and Qilian Mountains(NSTM and NSQM) in comparison with the southern slope of the Tianshan Mountains(SSTM).However,the FLH on NSKM has been decreasing with the speed of 2.33 m every year.(2) Abrupt change analysis indicates that the period of abrupt change happened for summer runoff and FLH is totally different among the four typical study regions,and even in same region.(3) There is a positive significant relation between the summer runoff and FLH in ARNC(NSQM P <0.05;other three regions P <0.01).Therefore,the ascending and descending of the summer FLH is a vital factor inducing the change of summer runoff in ARNC.(4) The elastic coefficient of summer runoff to the change of summer FLH on NSKM,NSTM,NSQM,and SSTM are 7.19,3.80,2.79,and 6.63,respectively,which indicates that there exists the regional difference in the sensibility of summer runoff to the change of summer FLH in ARNC.The distinct proportion of glacial meltwater runoff is an important cause resulting in the regional difference of sensibility. | CHEN ZhongSheng CHEN YaNing LI WeiHong | 2012 | Science China Earth Sciences2012,55,9: | 8 |
| 12 | On iterative learning control design for tracking iteration-varying trajectories with high-order internal model显示文摘In this paper,iterative learning control (ILC) design is studied for an iteration-varying tracking problem in which reference trajectories are generated by high-order internal models (HOIM).An HOIM formulated as a polynomial operator between consecutive iterations describes the changes of desired trajectories in the iteration domain and makes the iterative learning problem become iteration varying.The classical ILC for tracking iteration-invariant reference trajectories,on the other hand,is a special case of HOIM where the polynomial renders to a unity coefficient or a special first-order internal model.By inserting the HOIM into P-type ILC,the tracking performance along the iteration axis is investigated for a class of continuous-time nonlinear systems.Time-weighted norm method is utilized to guarantee validity of proposed algorithm in a sense of data-driven control. | Chenkun YIN Jianxin XU Zhongsheng HOU | 2010 | 控制理论与应用(英文版)2010,8,3: | 7 |
| 13 | Studies of the Genotoxicity of Glycidyl Methacrylate (GMA)显示文摘The following experiments were conducted to evaluate the genotoxic effects of GMA (glycidyl methacrylale) on mammalian and human cells.(1) Using the absorption spectrum shift method in vitro, we observed that the maximums of calf thymus DNA and GMA were shifted toward longer wavelengths (a change of more than 15nm) and the absorbance decreased after incubation at room temperature for 15min or more.The result indicates that binding of DNA and GMA had occurred.The binding force is strong, not affected by the addition of concentrated sodium chloride solution, and only slightly decreased by the addition of 8 M urea solution.Therefore the bond between DNA and GMA might be covalent.(2) In cell cultures, unscheduled DNA synthesis (UDS) in human and/or rat lymphocyte was induced and DNA semiconserva-tive replication was inhibited by GMA at concentrations of less than 5.2 mM.(3) Sperm abnormality tests and assays of UDS in germ cells of male mice were conducted to study the in vivo genotoxicity of GMA.The results revealed that GMA could damage DNA, increase sperm abnormality frequency, and reduce the number of sperm cells, 1990 Academic Press.Inc. | DAYING XIE, WEI ZHANG, LAIFU CAO, WENQING SUN, ZHONGSHENG LI, QING GAO, YILI WU, HUILAN GAO, HUIFANG YANG, JIM ZUO,~* AND FUDE FANG~* Institute oF Occupational Medicine. Chinese Academy ol Preventive Medicine. Beijing 100050. and *Institute of Basic Medical Sciences, Chinese Academy ol Medical Sciences. Beijing 100730, China | 1990 | Biomedical and Environmental Sciences1990,3,3: | 7 |
| 14 | 3D-QSAR study on atmospheric half-lives of POPs using CoMFA and CoMSIA显示文摘3D-QSAR studies of persistent organic pollutants(POPs)screening for atmosphere persistence were performed by comparative molecular field analysis(CoMFA)and comparative molecular similarity index analysis(CoMSIA)methods.The mean and maximum half-life estimations for degradation in air of 49 UNEP POPs and possible POPs were modeled.Both groups’data have been modeled to obtain an average estimate and a predictive value for ranking and screening purposes.CoMFA and CoMSIA models have given cross-validation regression coeffcient(q2)values of more than 0.69 and correlation coeffcient(r2)value of more than 0.84,which validated for their prediction,could be applied to predict unavailable data. | Yuyin LV Chunsheng YIN Hongyan LIU Zhongsheng YI Yang WANG | 2008 | Journal of Environmental Sciences2008,20,12: | 7 |
| 15 | Mercury distribution and bioaccumulation up the soil-plant-grasshopper-spider food chain in Huludao City, China显示文摘The purpose of this study is to investigate total mercury (THg) distribution and its bioaccumulation up the soil-plant-grasshopperspider in the Huludao City, which is polluted seriously by chlor-alkali and zinc smelting industry in Northeast of China. Results indicated that average THg concentrations in soil, plant leaves, grasshopper Locusta migratoria manilensis and Acrida chinensis, and spider were 0.151, 0.119, 0.167 and 0.134 mg/kg, respectively. THg spatial distribution suggested that most of mercury came from the chlor-alkali plant and the two zinc smelteries. The highest mercury concentration was found in the wings among different grasshoppers’ organs. Although spiders are the predatory, THg concentrations in their bodies were not high, and only on the same level as in grasshoppers, which might be due to spiders’ special living habits. In the light of the mercury transportation at every stage of the soil-plant-grasshopper-spider food chain, the bioaccumulation factors were 0.03, 0.79–1.11 and 0.80–1.13 respectively. It suggested that mercury biomagnification up terrestrial food chains was not so large and obvious as it was in the aquatic food chain. | Zhongsheng Zhang Qichao Wang Dongmei Zheng Na Zheng Xianguo Lu | 2010 | Journal of Environmental Sciences2010,22,8: | 6 |
| 16 | Robust iterative learning control for nonlinear systems with measurement disturbances显示文摘The iterative learning control (ILC) has been demon-strated to be capable of considerably improving the tracking perfor-mance of systems which are affected by the iteration-independent disturbance. However, the achievable performance is greatly degraded when iteration-dependent, stochastic disturbances are pre-sented. This paper considers the robustness of the ILC algorithm for the nonlinear system in presence of stochastic measurement disturbances. The robust convergence of the P-type ILC algorithm is firstly addressed, and then an improved ILC algorithm with a decreasing gain is proposed. Theoretical analyses show that the proposed algorithm can guarantee that the tracking error of the nonlinear system tends to zero in presence of measurement dis-turbances. The analysis is also supported by a numerical example. | Xuhui BuI FashanYu Zhongsheng Hou Haizhu Yang | 2012 | Journal of Systems Engineering and Electronics2012,23,6: | 6 |
| 17 | Benefit of everolimus as a monotherapy for a refractory breast cancer patient bearing multiple genetic mutations in the PI3K/AKT/mTOR signaling pathway显示文摘A postmenopausal patient with a diagnosis of estrogen receptor(ER)(+), progesterone receptor(PR)(+), and human epidermal growth factor receptor-2(HER2)(-) breast cancer was reported. The patient refused surgery and was resistant to conventional chemotherapy regimens. Computed tomography and the circulating tumor cell test indicated that the patient's tumor burden increased rapidly even after several chemotherapy sessions. Multiple genetic aberrances in the phosphatidylinositol3-kinases(PI3 K) signaling pathway were detected via next-generation sequencing(NGS)-based liquid biopsy, including a p. G1007 R missense mutation in exon 21 of PIK3 CA(33.61%), a p.L70 fs frameshift mutation in exon 3 of phosphatase and tension homolog deleted on chromosome ten(PTEN)(49.14%), and a p. D1542 Y missense mutation in exon 32 of mammalian target of rapamycin(m TOR)(1.66%). Therefore, only the m TOR inhibitor everolimus was administered to the patient. Partial remission(PR) was observed after 2 months, and sustained stable disease(SD) was observed after a year and a half. Subsequent sequencing showed that the mutation ratio of PIK3 CA decreased to 4.17%, and that the PTEN and m TOR mutations disappeared, which revealed the significant curative effect of everolimus. We report the first case of successful monotherapy treatment using everolimus in a patient with advanced breast cancer bearing mutations in genes involved in the PI3 K/ARK/m TOR signaling pathway. The success of this case highlights the invaluable clinical contribution of NGS-based liquid biopsy, as it successfully provided an optimal therapeutic target for the patient with advanced breast cancer. | Yehui Shi Wenwen Zhang Yingnan Ye Yanan Cheng Lei Han Pengpeng Liu Weipeng Zhao Zhongsheng Tong Jinpu Yu | 2018 | Cancer Biology & Medicine2018,15,3: | 6 |
| 18 | Drosophila RecQ5 is required for efficient SSA repair and suppression of LOH in vivo显示文摘RecQ5 in mammalian cells has been suggested to suppress inappropriate homologous recombination.However,the specific pathway(s)in which it is involved and the underlining mechanism(s)remain poorly understood.We took advantage of genetic tools in Drosophila to investigate how Drosophila RecQ5(dRecQ5)functions in vivo in homologous recombination-mediated double strand break(DSB)repair.We generated null alleles of dRecQ5 using the targeted recombination technique.The mutant animals are homozygous viable,but with growth retardation during development.The mutants are sensitive to both exogenous DSB-inducing treatment,such as gamma-irradiation,and endogenously induced double strand breaks(DSBs)by I-Sce I endonuclease.In the absence of dRecQ5,single strand annealing(SSA)-mediated DSB repair is compromised with compensatory increases in either inter-homologous gene conversion,or non-homologous end joining(NHEJ)when inter-chromosomal homologous sequence is unavailable.Loss of function of dRecQ5 also leads to genome instability in loss of heterozygosity(LOH)assays.Together,our data demonstrate that dRecQ5 functions in SSA-mediated DSB repair to achieve its full efficiency and in suppression of LOH in Drosophila. | Yixu Chen Wen Dui Zhongsheng Yu Changqing Li Jun Ma Renjie Jiao | 2010 | Protein & Cell2010,1,5: | 5 |
| 19 | Molecular Fingerprints of Soil Organic Matter in a Typical Freshwater Wetland in Northeast China显示文摘Natural wetlands are known to store huge amounts of organic carbon in their soils. Despite the importance of this storage,uncertainties remain about the molecular characteristics of soil organic matter(SOM), a key factor governing the stability of soil organic carbon(SOC). In this study, the molecular fingerprints of SOM in a typical freshwater wetland in Northeast China were investigated using pyrolysis gas-chromatography/mass-spectrometry technology(Py-GC/MS). Results indicated that the SOC, total nitrogen(TN),and total sulfur contents of the cores varied between 16.88% and 45.83%, 0.93% and 2.82%, and 1.09% and 3.79%, respectively. The bulk δ^13C and δ^15N varied over a range of 9.85‰, between –26.85‰ and –17.00‰, and between –0.126‰ and 1.002‰, respectively. A total of 134 different pyrolytic products were identified, and they were grouped into alkyl(including n-alkanes(C:0) and n-alkenes(C:1),aliphatics(Al), aromatics(Ar), lignin(Lg), nitrogen-containing compounds(Nc), polycyclic aromatic hydrocarbons(PAHs), phenols(Phs), polysaccharides(Ps), and sulfur-containing compounds(Sc). On average, Phs moieties accounted for roughly 24.11% peak areas of the total pyrolysis products, followed by Lg(19.27%), alkyl(18.96%), other aliphatics(12.39%), Nc compounds(8.08%), Ps(6.49%), aromatics(6.32%), Sc(3.26%), and PAHs(1.12%). Soil organic matter from wetlands had more Phs and Lg and less Nc moieties in pyrolytic products than soil organic matters from forests, lake sediments, pastures, and farmland.δ^13 C distribution patterns implied more C3 plant-derived soil organic matter, but the vegetation was in succession to C4 plant from C3 plant. Significant negative correlations between Lg or Ps proportions and C3 plant proportions were observed. Multiple linear analyses implied that the Ar and Al components had negative effects on SOC. Alkyl and Ar could facilitate ratios between SOC and total nitrogen(C/N), while Al plays the opposite role. Al was positively related to the ratio of dissolved organic carbon(DOC) to SOC. In summary, SOM of wetlands might characterize by more Phs and lignin and less Nc moieties in pyrolytic products. The use of Pyrolysis gas-chromatography/mass-spectrometry(Py-GC/MS) technology provided detailed information on the molecular characteristics of SOM from a typical freshwater wetland. | LI Zhe ZHANG Zhongsheng XUE Zhenshan SONG Xiaolin ZHANG Hongri WU Haitao JIANG Ming LYU Xianguo | 2019 | Chinese Geographical Science2019,29,4: | 4 |
| 20 | Detecting the breakup of spiral waves in small-world networks of neurons due to channel block显示文摘The breakup of a spiral wave by blockade of sodium and potassium channels in a small-world network of Hodgkin-Huxley neurons is investigated in detail.The influence of ion channel block in poisoned excitable membrane patches of a certain size is measured,by varying channel noise and channel densities resulting from the change in conductance,For example,tetraethylammonium is known to cause a block(poisoning) of potassium channels,while tetrodotoxin blocks sodium channels.We observed the occurrence of spiral waves,which are ordered waves believed to play an important role in facilitating the propagation of electric signals across quiescent regions of the brain.In this paper,the effect of channel block was measured by the factors xK and xNa,which represent the ratios of unblocked,or active,ion channels,to the overall number of potassium or sodium ion channels,respectively.To quantify these observations,we use a simple but robust synchronization measure,which succinctly captures the transition from spiral waves to other collective states,such as broken segments resulting from the breakup of the spiral wave.The critical thresholds of channel block can be inferred from the abrupt changes occurring in plots of the synchronization measure against different values of xK and xNa.Notably,small synchronization factors can be tightly associated with states where the formation of spiral waves is robust to mild channel block. | MA Jun HUANG Long YING HePing PU ZhongSheng | 2012 | Chinese Science Bulletin2012,57,17: | 4 |