一类可逆四次微分系统的细中心(英文)

讨论了一类相应三次系统具有等时中心的可逆四次多项式微分系统的细中心.应用多项式结式计算方法确定了本四次系统的细中心阶数,并给出其具有等时中心的条件.

一类三次系统的细中心与局部临界周期分支

研究了一类三次实自治系统细中心与局部临界周期分支问题.利用计算机代数系统Mathematica分别计算出了该实系统所对应的伴随复系统在三个中心条件下的复周期常数,得到原点为k(k=0,1,2,3)阶细中心的充分必要条件.得到了当原点为k(k=0,1,2,3)阶细中心时,该系统从原点能分支不多于k个局部临界周期分支.证明了该实系统恰有3个局部临界周期分支.

一类五次Lénard系统的细中心与局部临界周期分支

文章研究了一类五次Lénard系统的细中心与局部临界周期分支问题,利用计算机代数系统Mathematica进行奇点量与周期常数的计算,导出了系统原点的中心条件和细中心阶数。结果证明:该系统在原点最多能分支5个局部临界周期分支。

一个肿瘤的病毒治疗模型中细中心阶数的判断

讨论了一个利用溶瘤病毒控制肿瘤细胞的模型,得到了其中细中心的阶数。通过计算该中心平衡点邻域的周期函数,利用结式消元法和实根分离技术判断出该细中心的阶数是0,说明此平衡点邻域的周期函数是单调的。结论说明在中心的某个邻域内,感染和未感染病毒的肿瘤细胞数量变化的周期是单调的。这对于认识溶瘤病毒控制肿瘤细胞的动力学性质有一定的意义。

一类四次系统的细中心和局部临界周期分支

探讨了一类四次多项式微分系统的细中心和局部临界周期分支问题。首先运用复变换将实系统转换为对应的伴随复系统,而后针对伴随复系统建立原点的周期常数递推公式。利用得到的递推公式来编写程序,在中心条件下计算该系统的前几个周期常数,得到该系统原点成为m(m=0,1,2)阶细中心的条件,证明了该系统原点最多有2个局部临界周期分支。

基于欧洲中心细网格预报资料和观测资料的浙江省春夏降水性质分类指标

利用浙江省2004～2013年3～8月Micaps(气象信息综合分析处理系统)地面填图数据和T–logP数据研究杭州、衢州和台州三市的阵雨和雷雨个例,同时选取能表征雷雨并能区分阵雨与雷雨的气象预报因子:对流有效位能、850 hPa与500 hPa的温差、K指数、地面2 m温度,用临近探空的分析方法和决策树的分类方法初步建立了一个适用于浙江省春夏季降水性质分类指标。利用欧洲中心(ECMWF)细网格预报资料,对历史样本和2016年春、夏季分别作了检验。结果表明:除去有降水预报误差个例后,指标TS(Threat Score)评分超过0.53,雷雨阵雨综合命中率达到71%,空报率阵雨(10%)小于雷雨(43%),在不同地区和季节稍有区别;同时对浙江省2016年春夏两次典型大范围阵雨雷雨过程进行预报,效果很好。此方法不仅可以依据预报数据在短期内做出精细化降水性质分类预报,在中长期预报上也有表现力。

由《散步》引发的文本细读思探

本文立足初中语文新课程标准,从语文课程性质地位应与基本教学理念相统一的价值视角,密切结合语文课堂教学实践,重点对文本细读在教学中的运用进行了思考.

非线性φ_6型方程的局部临界周期分支

针对一类非线性波方程的局部临界周期分支问题,借用计算机代数系统Mathematica,计算对应平面微分自治系统的周期常数,得到平面自治系统原点成为一阶细中心的充要条件,并证明该系统在原点邻域存在1个局部临界周期分支。结果表明,该非线性波方程恰有1个局部临界周期分支。

两类非线性Schrdinger型方程的局部临界周期分支

针对非线性Schrdinger型方程的局部临界周期分支问题,通过行波变换将两类Schrdinger型方程转换为同一等价Hamiltonian系统,应用Mathematica计算Hamiltonian系统的周期常数,得到原点为一阶细中心的充要条件,并证明了该系统在原点邻域存在一个局部临界周期分支。分析结果表明,两类非线性Schrdinger型方程均恰有一个局部临界周期分支,即在原点附近邻域内闭轨周期的单调性变换一次。

Influence of Replacing Bacterial Pheophytin with Pheophytin on the Picosecond Fluorescence from Reaction Centers of Purple Bacteria

Fluorescence spectra of native purple bacterial reaction center (RC) and bacterial pheophytin (Bphe) replaced RCs were obtained from 600 nm to 900 nm with a selective excitation at 597 nm. With the help of measuring the fluorescence from bacterial chlorophyll, bacterial pheophytin and plant pheophytin, the corresponding components in the RCs are classified for fluorescence emission. Results showed that pheophytin substitution influences the composition of fluorescence spectra. Therefore, four, three and two components were obtained from fluorescence spectra of native RC, Bphe B_replaced RC and Bphe A,B _replaced RC, respectively. Fluorescence components are well correlated to the binding of plant pheophytin. The decay of excited state of primary electron donor P in different RCs was also studied by measuring the fluorescence decay at 686.4, 674.1 and 681.1 nm, respectively. The decaying kinetics changed in different RCs, indicating that pheophytin replacement influenced the energy transduction and primary photochemical reaction in purple bacterial reaction centers.

结核性液气胸选择不同引流管行胸腔闭式引流术的临床观察

目的比较常规胸腔引流管与双腔气囊导尿管、中心静脉穿刺细管用于结核性液气胸治疗的临床效果。方法结核性液气胸患者78例,随机分为观察1组25例、观察2组26例和对照组27例,行胸腔闭式引流术。观察1组用双腔气囊导尿管、观察2组用中心静脉穿刺细管、对照组用常规胸腔引流管(硅胶管或橡胶管)。观察3组置管顺利程度、术后疼痛程度、出血、皮下气肿发生率及程度、固定难易、脱管率、引流管通畅情况。结果与对照组比较,观察1组和观察2组的应用止痛药人数、明显出血、皮下气肿、切口感染、脱管、切口处外渗情况和遗留明显瘢痕方面比较,差异均有统计学意义(P<0.05);对照组引流堵管率为85.2%,与观察1组的引流堵管率4.0%比较,差异有统计学意义(P<0.05),观察1组和观察2组有引流堵管率比较,差异无统计学意义(P>0.05)。与对照组比较,观察1组和观察2组的肺复张时间和平均拔管天数方面比较,差异均有统计学意义(P<0.05);观察1组和观察2组肺复张时间和平均拔管天数比较,差异无统计学意义(P>0.05)。结论结核性液气胸治疗根据气体量多少不同宜选用双腔气囊导尿管或用中心静脉穿刺细管。

The Structural Transformation of Nucleolar DNA and Its Arrangement in Nucleolus of Allium cepa Cells

By using the DNA specific cytochemical staining method (NAMA_Ur) and conventional electron microscopic technique, the authors examined the configuration of intranucleolar DNA in Allium cepa L. cells and found that nucleolar DNA within the fibrillar center (FC) underwent a structural transformation process from condensed to extended state. The authors' observations also displayed a continuous arrangement process of nucleolar DNA, i.e., the extranucleolar DNA entered FC through the nucleolar organizer region (NOR) channel, then extended to the periphery of FC or to the border between FC and dense fibrillar component (DFC), and distributed along the periphery of FC. Thence, by passing through the NOR channel between FCs, the nucleolar DNA continued to transfer to other FCs and arranged in the same above_mentioned forms.

Theoretical Studies on the Mechanism of the Proton-transfer-coupled Electron Transfer Reactions Between Menaquinone Q_A and Ubiquinone Q_B in the Bacterial Photosynthetic Reaction Center of Rhodopseudomona viridis

The mechanism of the proton_transfer_coupled electron transfer (PT_ET) reactions between the menaquinone Q A (MQ 1) and ubiquinone Q B (UQ 1) in the bacterial photosynthetic reaction center of Rhodopseudomona viridis was studied by using the B3LYP/6_31G(d) method. The changes of standard Gibbs free energy ΔG 0 of all possible reactions followed the ET reaction (1) were calculated. The results indicated that: (1) according to the ΔG 0 values of corresponding reactions, UQ 1 could not accept two electrons from MQ - 1 continually without the coupled proton transfer reactions. Because of ΔG 0 2b 0, ΔG 0 3b 0 and ΔG 0 4b 0, the corresponding PT_ET reactions could take place along with reactions (2b), (3b) and (4b) sequentially; (2) on the gaseous condition, the first and second transferred protons (H +(1) and H +(2)) from the surrounding amino acid residues or water molecules will combine with the oxygen No.7 and oxygen No.8 of UQ 1, respectively. On the condition of protein surroundings (by SCRF model, ε =4.0), the results are converse but the energy difference between the combination of H +(1) and H +(2) with UQ - 1 is quite small. The difference of ΔG 0 values between the corresponding reactions in gaseous surroundings and the SCRF model is not significant; (3) the PT_ET reactions between MQ 1 - and UQ 1 - should be as follows: MQ 1 -+UQ 1→MQ 1+UQ 1 - (1) UQ 1 - ( O (7) )+H +( HisL 190)→UQ 1H(2b) ( Gas ) or UQ 1 - ( O (8) )+H +(H 2O)→UQ 1H (2b') ( SCRF ) or UQ 1 - ( O (8) )+H + ( ArgL 217)→UQ 1H(2b') ( SCRF ) MQ 1 -+UQ 1H→MQ 1+UQ 1H - (3b) ( Gas ) MQ 1 -+UQ 1H→MQ 1+UQ 1H -(3b') ( SCR F) UQ 1H -+H +(H 2O)→UQ 1H 2(4b) ( Gas ) or UQ 1H -+H + ( ArgL 217)→UQ 1H 2 (4b) ( Gas ) or UQ 1H -+H + ( HisL 190)→UQ 1H 2 (4b') ( SCRF )

2014—2016年数值降水预报在天津的检验评估

对2014—2016年中国国家气象中心T639数值预报、日本细网格数值预报、欧洲中心细网格(EC-thin)数值预报以及天津市乡镇指导预报产品中在天津地区降水预报分别进行检验。结果表明:所有模式降水的晴雨预报准确率均随预报时效的延长而下降。降水预报准确率在秋冬春季的预报效果明显好于夏季。EC-thin产品在冬季降水的预报中优势更为明显,而指导预报及T639对5月、6月及9月天津地区局地降水多发期的降水更有指示意义。针对2014—2016年天津地区的23个暴雨日按影响系统分型并统计检验结果,暴雨日降水预报晴雨成绩较好有参考价值,而降水分级检验偏差较大。相对于局地性暴雨过程,区域性的暴雨过程数值预报有更为可靠的参考性。

Calmodulin regulates the post-anaphase reposition of centrioles during cytokinesis

A transient postanaphase repositioning of the centriole is found to control the completion of cytokinesis. Using agreen fluorescent protein-calmodulin fusion protein as a living cell probe, we have previously found that calmodulin isassociated with the initiation and progression of cytokinesis. In this study, we further studied the effect of calmodulinon the repositioning of the centriole and subsequent cell cycle progression. When activity of calmodulin is inhibited, theregression of the centriole from the intercellular bridge to the cell center is blocked, and thus the completion of celldivision is repressed and two daughter cells are linked by longer cell bridge in perturbed cells. W7 treatment duringcytokinesis also results in unfinished cytokinesis and stopped G1 phase. These results suggest that calmodulin activity isrequired for centriole repositioning and can affect the completion of cytokinesis and cell cycle progression.

Mutations in hepatitis B virus core regions correlate with hepatocellular injury in Chinese patients with chronic hepatitis B

AIM: To elucidate the relationship between the frequency of core mutations and the clinical activity of hepatitis B virus (HBV)-related liver disease and to characterize the amino acid changes in the core region of HBV.METHODS: We studied 17 Chinese patients with chronic hepatitis B according to their clinical courses and patterns of the entire core region of HBV.RESULTS: Amino acid changes often appeared in the HBV core region of the HBV gene in patients with high values of alanine aminotransferase (ALT) or with the seroconversion from HbeAg to anti-HBe. The HBV core region with amino acid changes had high frequency sites that corresponded to HLA Ⅰ/Ⅱ restricted recognition epitopes reported by some investigators.CONCLUSION: The core amino acid changes of this study occur due to influence of host immune system. The presence of mutations in the HBV core region seems to be important for predicting the clinical activity of hepatitis B in Chinese patients.

Neutrophil-to-lymphocyte ratio compared to N-terminal pro-brain natriuretic peptide as a prognostic marker of adverse events in elderly patients with chronic heart failure

Background The neutrophil-to-lymphocyte （N/L） ratio has been associated with poor prognosis in patients with heart failure, but it has not been compared with N-terminal pro-brain natriuretic peptide （NT-proBNP） in elderly patients with chronic heart failure （CHF）. We sought to make this comparison. Methods A total of 1355 elderly patients with CHF were analyzed. A multivariate logistic regression model was used to analyze the variables associated with atrial fibrillation （AF）. Cox regression analysis was used to assess the multivariable rela- tionship between the N/L ratio, NT-proBNP level, and subsequent major cardiovascular events （MCE）. Results In the multiple logistic regression analysis, the N/L ratio was demonstrated as a risk factor for AF in elderly patients with CHF [odds ratio （OR）： 1.079, 95% confi- dence interval （CI）： 1.027-1.134, P = 0.003]. The median follow-up period was 18 months. In a multivariable model using tertiles of both variables, the highest tertile of the N/L ratio was significantly associated with MCE [hazard ratio （HR）： 1.407, 95% CI： 1.098-1.802, P = 0.007] compared with the lowest tertile. Similarly, the highest NT-proBNP tertile was also significantly associated with MCE （HR： 1.461, 95% CI： 1.104-1.934, P- 0.008）. Conclusions In elderly patients with CHF, the N/L ratio is one of the important risk factors for AF and it is an inexpensive and readily available marker with similar independent prognostic power to NT-proBNP. The risk of MCE increases 1.407-fold when the N/L ratio is elevated to the highest tertile.

Evaluation of 5 versus 10 granulocyteaphaeresis sessions in steroid-dependent ulcerative colitis: A pilot, prospective, multicenter, randomized study

AIM： To evaluate the efficacy of 5 compared to ：tO granulocyteaphaeresis sessions in patients with active steroid-dependent ulcerative colitis. METHODS： In this pilot, prospective, multicenter randomized trial, 20 patients with moderately active steroid-dependent ulcerative colitis were randomized to 5 or 10 granulocyteaphaeresis sessions. The primary objective was clinical remission at wk 17. Secondary measures included endoscopic remission and steroid consumption.RESULTS： Nine patients were randomized to 5 granulocyteaphaeresis sessions （group 1） and 11 patients to 10 granulocyteaphaeresis sessions （group 2）. At wk 17, 37.5% of patients in group 1 and 45.45% of patients in group 2 were in clinical remission. Clinical remission was accompanied by endoscopic remission in all cases. Eighty-six percent of patients achieving remission were steroid-free at wk 17. Daily steroid requirements were significantly lower in group 2. Eighty-nine per cent of patients remained in remission during a one year follow-up. One serious adverse event, not related to the study therapy, was reported. CONCLUSION： Granulocyteaphaeresis is safe and effective for the treatment of steroid-dependent ulcerative colitis. In this population, increasing the number of aphaeresis sessions is not associated with higher remission rates, but affords a significant steroid-sparing effect.

Bioassay-Guided Extraction of Crude Fucose-Containing Sulphated Polysaccharides from Sargassum fusiforme with Response Surface Methodology

The response surface methodology(RSM) combined with bioassays was employed to optimize the extraction process of crude fucose-containing sulphated polysaccharides(c FCSP) from Sargassum fusiforme. The central composite design(CCD) was used with four variables, five levels, and four responses. The four variables were p H value of hydrochloric acid solution, extraction temperature(℃), ratio of liquid to raw material(m L g^(-1)), and extraction time(h), respectively. Chemical and bioassay indices were used in combination as the response parameters, which included the yield of c FCSP, fucose content, proliferation rate of spleen cells, and lipopolysaccharide-induced proliferation of splenocytes. The experimental data were fitted to a second-order polynomial equation using multiple regression analysis, and examined using the appropriate statistical methods. The best extraction conditions were as follows: the p H value of hydrochloric acid solution was 3.50; the extraction temperature was 100℃; the ratio of liquid to raw material was 15.00 m L g^(-1) and the extraction time was 2.50 h. The experimental yield was close to the predicted from the model. The extract could promote spleen lymphocyte proliferation, especially the lipopolysaccharide-induced lymphocyte proliferation in vitro, which suggested that its immunomodulatory effect on B lymphocytes. Therefore, c FCSP extracted from S. fusiforme could be utilized as an immunostimulant in functional foods and pharmaceutical industry in future.

Multicentric giant cell tumor of bone:a report of nine cases and literature review

Objective:The aim of this study was to investigate the clinical,radiographic and histiopathologic features of multicentric giant cell tumor of bone.Methods:All the clinical data of twenty tumors in nine patients of multicentric giant cell tumor that underwent surgical treatment in our department from 1990 to 2010 were retrospectively reviewed,which included three males and six females.The patients ranged from 15 to 45 years at diagnosis,with an average age of 22.3 years.Three of the patients were younger than twenty years of age.Most tumors arose in long bones,especially around the knee.Radiographically,the tumors in long bones usually manifested as expansive lytic lesions involving the metaphysis and extending into the epiphysis.Three tumors in three patients were confined to the metaphysis,and one tumor exhibited bone-forming lesions.All tumors were treated with curettage or resection.Results:The typical "giant cell" could be found in the oncologic examination in all cases.In some areas,such as the fibrohistiocytic regions,reactive bone forming and aneurysmal bone cyst-like changes could be found.Follow-up averaged 3.5 years,ranging from 6 months to 12 years.There was a recurrence of three tumors,and one patient died of pulmonary metastasis.Conclusion:Multicentric giant cell tumor occur often in younger patients than do solitary giant cell tumor.They are frequently present around the knee,and confined to the metaphysis.Each tumor arose independently,rather than being in multiple sites of metastatic lesion that develop from a single tumor.The risk of recurrence depends on the type of surgery that is performed.