稀释中的优化模型及其研究

本文利用时间价值系数和试剂价值系数，从离散系统和连续系统两个角度对分次稀释问题分别建立了稀释的非线性规划数学模型（2）一（4），研究了它们的最优解的存在性及最优解的求法公式（定理1—理3）．最后用BASIC语言编制了求模型（3）最优解的算法程序.     

Modulation of the Ca(2+) permeability of human endplate acetylcholine receptor-channel

In slow-channel congenital myasthenic syndrome, point mutations of the endplate acetylcholine receptor (AChR) prolong channel openings, leading to excessive Ca(2+) entry with ensuing endplate degeneration and myasthenic symptoms. The Ca(2+) permeability of the human endplate AChR-channel is quite high, and is further increased by two slow-channel mutations in its ? subunit, worsening the pathological cascade. To gain further support to the hypothesis that the ? subunit plays a crucial role in controlling Ca(2+) permeability of endplate AChR-channel, in this work we measured the fractional Ca(2+) current (P(f), i.e., the percentage of the total current carried by Ca(2+) ions) of a panel of AChR carrying slow-channel mutations in the α, β and ? subunits detected in patients (α(N217K), α(S226Y), α(C418W), β(V266A), β(V266M), ?(I257F), ?(V265A) and ?(L269F)). We confirm that only mutations in the ? subunit altered Ca(2+) permeability of AChR-channels, with ?(L269F) increasing P(f) (10% vs. 7% of wild type AChR) and ?(I257F) decreasing it (to 4.6%). We also found that, for ?(L269F)-AChR, the Ca(2+) permeability and ACh-induced cell death can be normalized by clinically relevant concentrations of salbutamol or verapamil, providing the first evidence that the Ca(2+) permeability of AChR-channels can be modulated and this treatment may provide protection against excitotoxic insults.     

腹腔镜与开放输尿管切开取石术治疗输尿管结石的临床疗效分析

目的:比较腹腔镜与传统开放手术行输尿管切开取石术治疗输尿管结石的临床效果,评价腹腔镜手术的优势。方法:回顾性分析我院2011年9月~2013年2月45例行开放输尿管切开取石术(开放组)与33例行腹腔镜输尿管切开取石术(腹腔镜组)患者的临床资料并进行比较。结果:78例手术均取石成功,腹腔镜组2例分别因结石逃逸入肾盂和输尿管炎症水肿粘连明显改行开放手术。腹腔镜组在术中出血量、术后下床时间、肛门排气时间、术后引流总量、术后引流时间、住院天数方面均显著优于开放组,而手术时间及住院总费用显著高于开放组,差异均有统计学意义(P0.05)。两组患者术后均未出现尿瘘、伤口愈合不良、严重血尿等并发症。结论:两组术式治疗输尿管结石均能有效取石,腹腔镜术式在很多方面拥有一定优势,传统切开取石也有自己的特点。临床上应综合考虑患者意愿、病情特点、术者操作水平、患方经济条件等一系列因素决定最终手术方式。     

输尿管软镜治疗小儿上尿路结石的疗效及对血清炎症因子的影响

目的:探讨输尿管软镜治疗小儿上尿路结石的疗效及对血清炎症因子的影响。方法:选择2013年4月至2016年4月我院收治的上尿路结石患儿60例,通过随机数表法分为观察组(n=30)和对照组(n=30),对照组给予经皮肾镜激光碎石,观察组采用输尿管软镜取石术进行治疗。观察记录两组患者术中出血量、手术时间、住院天数及疼痛评分;比较两组患者白细胞介素-10(IL-10)、C反应蛋白(CRP)、白细胞(WBC)水平、并发症发生情况及结石的清除率。结果:观察组患者手术时间、术中出血量、住院天数以及疼痛评分均低于对照组,差异均具有统计学意义(P0.05);两组患儿术前IL-10、CRP及WBC水平无明显差异;术后两组患儿各项炎性因子均明显增加(P0.05),观察者患儿IL-10、CRP及WBC水平显著低于对照组,差异具有统计学意义(P0.05);术后,观察组患者并发症总发生率为6.67%,明显低于对照组的33.33%,差异具有统计学意义(P0.05);两组患者结石清除率无明显差异(P0.05)。结论:输尿管软镜取石术治疗上尿路结石安全有效、创伤小、并发症少,患者产生的应激反应小,值得临床推广和应用。     

CO2点阵激光联合湿润烧伤膏对创伤性瘢痕的疗效分析

目的:探讨CO_2点阵激光联合湿润烧伤膏治疗创伤性瘢痕的临床疗效。方法:选取73例创伤性瘢痕患者,年龄21-35岁,对照组(35例)给予CO_2点阵激光术治疗,术后涂抹莫匹罗星软膏护理,观察组(38例)采用CO_2点阵激光术联合湿润烧伤膏治疗。通过对患者治疗后3个月的体征、疗效及3个月内不良反应的发生情况评价CO_2点阵激光术联合湿润烧伤膏对创伤性瘢痕的疗效。结果:与治疗前相比,两组治疗后3个月的VSS评分均明显提高(P0.05),但两组间VSS评分相比差异没有统计学意义(P0.05)。治疗后3个月,观察组的治疗有效率明显高于对照组(P0.05),治疗后3个月期间,观察组的不良反应发生率明显低于对照组(P0.05),色素沉积和创面感染是主要的不良反应症状。结论:CO_2点阵激光技术联合润湿烧伤膏对于创伤性瘢痕具有良好的治疗效果,且安全性高。     

输尿管镜钬激光碎石术与气压弹道碎石术治疗下段输尿管结石的临床疗效分析

目的:探讨输尿管镜钬激光碎石术与气压弹道碎石术治疗下段输尿管结石的临床疗效。方法:选取146例输尿管下段结石患者,将所有患者随机分为试验组和治疗组两组,其中试验组患者均采取输尿管镜钬激光碎石术进行治疗,而对照组患者则采取气压弹道碎石术进行治疗,比较两组患者手术前后的血清肌酐(Serum creatinine,Sc R)和血尿素氮(Blood urea nitrogen,BUN)等手术指标。结果:对照组患者完成手术所需要的时间和住院时间以及血尿时间均明显长于试验组患者,对照组患者之中的碎石成功率为71.91%(105例),明显低于试验组患者的碎石成功率84.25%(123例),两组患者之间的数据比较均有统计学意义(均P0.05)。两组患者手术之前的BUN和Sc R水平均无明显差异,而在手术之后两组患者的BUN和Sc R水平均显著降低,并且试验组患者的降低幅度明显大于对照组患者(均P0.05)。试验组患者在术后一个月时的结石排净率为94.52%,明显高于对照组患者的83.56%(P0.05);试验组患者的并发症发生率为3.42%,明显低于对照组患者的13.01%(P0.05);并且试验组患者的止痛药使用比例为20.00,明显低于对照组患者的34.62(均P0.05)。结论:输尿管镜钬激光碎石术在治疗输尿管下段结石方面效果显著,且具有安全性高和创伤小以及恢复速度快等优势。     

彩色多普勒超声引导下经皮肾镜取石术（PCNL）治疗复杂性肾结石的临床分析

目的：总结彩色多普勒超声引导下经皮肾镜取石术（percutaneousnephrolithotomy,PCNL）治疗的复杂性肾结石的经验及其安全性、有效性以及常见并发症。方法：回顾性分析我院2011年7月-2012年8月采用彩色多普勒引导下经皮肾镜治疗复杂性肾结石患者56例的临床资料。结果：所有患者均I期建立经皮肾通道,平均手术时间（107．5±27．5）分钟,24例行EMS气压弹道联合超声碎石（1001．0±27．9）分钟,20例行钬激光联合超声碎石（119．4±23．6）分钟,10例行单纯超声碎石（108．2±30．2）分钟,EMS气压弹道联合超声碎石组的手术时间少于钬激光碎石组,差异有统计学意义（P〈0．05,单纯超声碎石组与另外两组比较无统计学意义P〉0．05）。术前肾功能损伤患者术后随访,肾功能明显改善。结石完全清除率91％,结石部分残留率9％。术中均无严重出血,无周边脏器损伤。术后出现迟发出血5例,反复发热4例,均经对症治疗后缓解。结论：彩色多普勒超声引导除了具有普通超声引导的优势外,还可有效避开肾实质大血管损伤,减少术中及术后出血风险。彩色多普勒超声引导下经皮肾镜碎石取石术是一种治疗复杂性肾结石安全、有效的方法。     

Transformations of covariates for longitudinal data

This paper develops a general approach for dealing with parametric transformations of covariates for longitudinal data, where the responses are modeled marginally and generalized estimating equations (GEEs) are used for estimation of regression parameters. We propose an iterative algorithm for obtaining regression and transformation parameters from estimating equations, utilizing existing software for GEE problems. The algorithmic technique is closely related to that used in the Box-Tidwell transformation in classical linear regression, but we develop it under the GEE setting and for more general transformation functions. We provide supporting theorems for consistency and asymptotic Normality of the estimates. Inference between two nested models is also considered. This methodology is applied to two data sets. One consists of pill dissolution data, the other is taken from the Pittsburgh Youth Study (PYS). The PYS is a prospective longitudinal study of the development of delinquency, substance use, and mental health in male youth. We use the model-based parametric approach to examine the association between alcohol use at an early stage of adolescent development and delinquency over the course of adolescence.     

Fractional purification and bioconversion of hemicelluloses

Hemicelluloses are types of plant cell wall polysaccharides, and the world's second most abundant renewable polymers after cellulose in lignocellulosic materials. They represent a type of hetero-polysaccharide with complex structure containing glucose, xylose, mannose, galactose, arabinose, rhamnose, glucuronic acid, and galacturonic acid in various amounts, depending on the source. Hemicelluloses are usually bonded to other cell-wall components such as cellulose, cell-wall proteins, lignin, and phenolic compounds by covalent and hydrogen bonds, and by ionic and hydrophobic interactions. This paper provides a review on hemicelluloses from lignocellulosic materials, especially in regard to their isolation and purification methods, and bioconversion. Current isolation and purification strategies are summarized, including: alkali peroxide extraction, organic solvent extraction, steam explosion, ultrasound-assisted extraction, microwave-assisted extraction, column chromatography, and membrane separation. In addition, the bioconversion of hemicelluloses including pretreatment, enzymatic hydrolysis, and fermentation are discussed.     

通过烟台午台遗址人牙结石淀粉粒探究人类对植物资源的利用

本研究通过对山东烟台市午台遗址人牙结石淀粉粒的分析,发现了来自禾本科的粟(Setaria italica L.)、小麦族(Triticeae)、壳斗科栎属(Quercus sp.)、豆科(Fabaceae)及块根块茎类植物的淀粉粒,数量较为丰富,种属来源较为多样,显示了午台遗址先民利用植物性食物资源的多样性。研究表明午台先民除了利用粟黍类农作物作为主要食物资源外,还广泛采集一些野生果类和块根块茎类作为食物的补充。本研究中发现了大遗存中没有发现的壳斗科栎属等,弥补了大遗存研究的不足。