Rapid fabrication of zwitterionic sulfobetaine vinylimidazole-based monoliths via photoinitiated copolymerization for hydrophilic interaction chromatography

Zwitterionic sulfobetaine-based monolithic stationary phases have attracted increasing attention for their use in hydrophilic interaction chromatography. In this study, a novel hydrophilic polymeric monolith was fabricated through photo-initiated copolymerization of 3-(3-vinyl-1-imidazolio)-1-propanesulfonate (SBVI) with pentaerythritol triacrylate using methanol and tetrahydrofuran as the porogenic system. Notably, the duration for the preparation of this novel monolith was as little as 5 min, which was significantly shorter than that required for previously reported sulfobetaine-based monoliths prepared via conventional thermally initiated copolymerization. Moreover, these monoliths showed good morphology, permeability, porosity (62.4%), mechanical strength (over 15 MPa), column efficiency (51,230 plates/m), and reproducibility (relative standard deviations for all analytes were lower than 4.6%). Mechanistic studies indicated that strong hydrophilic and negative electrostatic interactions might be responsible for the retention of polar analytes on the zwitterionic SBVI-based monolith. In particular, the resulting monolith exhibited good anti-protein adhesion ability and low nonspecific protein adsorption. These excellent features seem to favor its application in bioanalysis. Therefore, the novel zwitterionic sulfobetaine-based monolith was successfully employed for the highly selective separation of small bioactive compounds and the efficient enrichment of N-glycopeptides from complex samples. In this study, we prepared a novel zwitterionic sulfobetaine-based monolith with good performance and developed a simpler and faster method for preparation of zwitterionic monoliths.     

益气化瘀化痰养阴方剂对肝纤维化大鼠TGF-β1表达的影响

目的 观察益气化瘀化痰养阴方剂对主要以CCl4诱导的大鼠肝纤维化肝组织TGF-β1表达的影响,探讨益气、化瘀、化痰、养阴单剂与合剂治疗肝纤维化的疗效评价.方法 将130只雄性SD大鼠随机分为正常对照组10只,肝纤维化模型组、益气组、化瘀组、化痰组、养阴组、合剂组各20 只.除正常对照组外,各实验组采用皮下注射四氯化碳+低蛋白高脂饮食+酒精饮料的方法制备肝纤维化模型.模型成功后,根据组别分别灌服生理盐水、益气的黄芪白术饮、化瘀的川芎姜黄饮、化痰的半夏海藻饮、养阴的鳖甲白芍饮和上述8药合煎的具有益气化瘀化痰养阴作用的合剂.于12周末,进行心脏灌注.通过Masson三色胶原染色和电镜以观察肝组织结构的变化,采用RT-PCR及Westem Blot方法观察各组TGF-β1的基因和蛋白表达变化.结果 与肝纤维化模型组相比,益气、化瘀、化痰、养阴单剂均有效降低肝组织内纤维化程度也可以降低大鼠肝组织TGF-β1基因和蛋白表达(P＜0.05).在单剂治疗中,与其它3组相比,益气组疗效最差(P＜0.05),养阴组疗效最好(P＜0.01),化瘀与化痰两组差异不大(P＞0.05).与单剂相比,合剂更能有效降低大鼠肝组织纤维化程度,降低TGF-N基因和蛋白表达(P＜0.05).结论 单剂治疗都可以降低肝组织内纤维化程度,但也有程度差异;合剂更能够明显降低肝组织内纤维化程度,说明益气化瘀化痰养阴法对肝纤维化能达到更好的疗效.     

通络化痰胶囊治疗脑梗死恢复期痰瘀阻络证353例临床研究

目的 评价通络化痰胶囊治疗脑梗死恢复期(痰瘀阻络证)的安全性及有效性.方法 采用多中心随机双盲对照方法,在7个临床试验中心筛选479例受试者,随机分为对照组121例与试验组358例,分别给予血栓心脉宁胶囊和通络化痰胶囊治疗,以神经功能缺损程度评分、中风病证候评分及血脂和血液流变学检查为疗效评价指标,以一般生命体征、血、尿、便常规检查、心电图、肝功能(丙氨酸氨基转移酶)、肾功能(血尿素氮、血肌酐)为安全性评价指标.结果 472例完成了试验,其中对照组119例,试验组353例.对照组临床神经功能缺损程度综合疗效愈显率和总有效率分别为22.69％、71.43％,试验组为37.96％、84.70％,试验组优于对照组(P＜0.01);对照组中医证候疗效愈显率和总有效率分别为30.25％、68.91％,试验组为50.99％、83.85％,试验组优于对照组(P＜0.01).治疗前后组内及治疗后组间比较,血脂及血液流变学指标差异均无统计学意义(P＞0.05).结论 通络化痰胶囊治疗脑梗死恢复期痰瘀阻络证可以较好地减少神经功能缺损症状及改善中医证候,但对血脂及血液流变学指标无明显改善作用;该药安全性较好,无明显不良反应.     

马云枝治疗中风合并再生障碍性贫血的临床经验

目的：探讨马云枝老师治疗中风合并再生障碍性贫血的临床经验。方法：通过观察马云枝老师以培元固本为原则,方用八珍汤加减（党参30 g,黄芪90 g,生白术15 g,川芎15 g,当归10 g,生熟地黄各12 g,茯苓30 g,陈皮10 g,石菖蒲15 g,远志15g,炙甘草3g）治疗中风合并再生障碍性贫血的临床疗效,总结其临床经验。结果：马老认为西药治疗以抗感染,清除脑内自由基为主,中药以健脾益气养血,化痰通络为主,培元固本。结论：培元固本法能明显改善患者临床症状,疗效显著,并提高生存质量。     

Assessment of asymmetry in a normal occlusion sample and asymmetric patients with three-dimensional cone beam computed tomography: A study for a transverse reference plane

Objective:To characterize symmetrical features of patients with facial asymmetry and thus to find the most reliable horizontal reference lines easily used in three-dimensional images. The hypothesis was that there is a difference in the location of bilateral landmarks of the upper skull between the normal occlusion sample and skeletal Class III patients with asymmetry.Materials and Methods:Group 1 (normal occlusion sample) was composed of 20 Korean adults with normal occlusion and no noticeable asymmetry. Groups 2 through 4 were selected from patients who were diagnosed as skeletal Class III malocclusion and grouped according to the extent of asymmetry (group 2: symmetric mandible, no maxillary cant; group 3: asymmetric mandible, no maxillary cant; group 4: asymmetric mandible, more than 4 mm maxillary cant measured at maxillary first molars). Three-dimensional cone beam computed tomography images were taken before treatment, and bilateral landmarks of the skull were located and their vertical and horizontal differences compared.Results:No statistically significant difference was noted in the position of bilateral landmarks between groups, except for AG (P < .05). AG showed significant differences in vertical dimension (P < .001) and in horizontal dimension (P < .0001) between groups. The mean of the difference was clearly greatest at FM.Conclusions:The hypothesis is rejected. All groups had a similar pattern of asymmetry in the upper third of the face. Therefore, the transverse reference line of the bilateral Z or orbitale may be used even in patients with severe asymmetry of the maxilla with reference to the clinical photos.     

“白血”之古籍探微

"白血"一词首次出现在《素问·至真要大论》。通过检索古籍,分析归纳历代医家对"白血"一词的有关论述,归纳针对其本质的探讨,有"肺血""肾精""脾痰"三种观点。对《内经》原文条分缕析,认为"白血"实乃燥气所胜、金实乘木,所吐之"肺血肺阴",并总结历代医家关于"白血"之治法,以丰富对"白血"的认识。     

Nonparametric coalescent inference of mutation spectrum history and demography

As populations boom and bust, the accumulation of genetic diversity is modulated, encoding histories of living populations in present-day variation. Many methods exist to decode these histories, and all must make strong model assumptions. It is typical to assume that mutations accumulate uniformly across the genome at a constant rate that does not vary between closely related populations. However, recent work shows that mutational processes in human and great ape populations vary across genomic regions and evolve over time. This perturbs the mutation spectrum (relative mutation rates in different local nucleotide contexts). Here, we develop theoretical tools in the framework of Kingman’s coalescent to accommodate mutation spectrum dynamics. We present mutation spectrum history inference (mushi), a method to perform nonparametric inference of demographic and mutation spectrum histories from allele frequency data. We use mushi to reconstruct trajectories of effective population size and mutation spectrum divergence between human populations, identify mutation signatures and their dynamics in different human populations, and calibrate the timing of a previously reported mutational pulse in the ancestors of Europeans. We show that mutation spectrum histories can be placed in a well-studied theoretical setting and rigorously inferred from genomic variation data, like other features of evolutionary history.

Over the past decade, population geneticists have developed many sophisticated methods for inferring population demography and have consistently found that simple isolated populations of constant size are far from the norm (reviewed in refs. 1–3). Population expansions and founder events, as well as migration between species and geographic regions, have been inferred from virtually all high-resolution genetic datasets. We now recognize that inferring these nonequilibrium demographies is often essential for understanding the histories of adaptation and global migration. Population genetics has uncovered many features of human history that were once virtually unknowable by other means, revealing a complex series of migrations, population replacements, and admixture networks among human groups and extinct hominoids.Although demographic inference methods can model complex population histories, the germline mutation process that creates variation has long received a comparatively simple treatment. A single parameter, μ, is used to represent the mutation rate per generation at all loci, in all individuals, and at all times. In humans, μ is estimated from parent–child trio sequencing studies, and modest variation in μ can have major effects on the interpretation of inferred parameters, such as times of admixture and population divergence. In other organisms, for which trio sequence data are usually unavailable, μ is estimated from sequence divergence between species with a fossil-calibrated divergence time, and these estimates come with still higher uncertainty.A growing body of evidence indicates that simple, constant mutation rate models may not adequately describe how variation accumulates on either inter- or intraspecific timescales (4–7). Germline mutation rates appear to have evolved during the speciation of great apes and the divergence of modern human populations (reviewed in ref. 8). Much of this evolution might be caused by nearly neutral drift (9), but a contributing factor could be selection on traits, like life history and chromatin structure, that indirectly affect mutation accumulation. Because mutation is intimately tied to the basic housekeeping process of cell division, gamete production, and embryonic development, the accumulation of mutations is likely to be complexly coupled to other biological processes (10–12).It is difficult to disentangle past changes in mutation rate from past changes in effective population size, which modulate levels of polymorphism even when the mutation rate stays constant. However, evolution of the mutation process can be indirectly detected by measuring its effects on the mutation spectrum: the relative mutation rates among different local nucleotide contexts. Hwang and Green (13) modeled the triplet context dependence of the substitution process in a mammalian phylogeny, finding varying contributions from replication errors, cytosine deamination, and biased gene conversion and showing that the relative rates of these processes varied between different mammalian lineages. Many cancers also exhibit somatic hypermutability of certain triplet motifs due to different DNA damage agents and failure points in the DNA repair process (14, 15). Harris (6) and Harris and Pritchard (7) examined the variation of triplet spectra between closely related populations, counting single-nucleotide variants in each triplet mutation type as a proxy for mutational input. They found that human triplet spectra distinctly cluster by continental ancestry group and that historical pulses in mutation activity influence the distribution of allele frequencies in certain mutation types. The divergence of mutation spectra among human continental groups has been replicated in independently generated datasets (7, 16), and similar patterns have been observed in other species, including great apes (17), mice (18), and yeast (19). Some of the mutation spectrum divergence between mice and yeast lineages has been mapped to mutator alleles (19, 20).Emerging from the literature is a picture of a mutation process evolving within and between populations, anchored to genomic features and accented by spectra of local nucleotide context. If probabilistic models of population genetic processes are to keep pace with these empirical findings, mutation deserves a richer treatment in state-of-the-art inference tools. In this paper, we build on classical theoretical tools to introduce fast nonparametric inference of population-level mutation spectrum history (MuSH)—the relative mutation rate in different local nucleotide contexts across time—alongside inference of demographic history. Whereas previous work has uncovered mutation spectrum evolution using summary statistics of standing variation, we shift perspective to focus on inference of the MuSH, which we model on the same footing as demography.Demographic inference requires us to invert the map that takes population history to the patterns of genetic diversity observable today. This task is often simplified by first compressing these genetic diversity data into a summary statistic such as the sample frequency spectrum (SFS), the distribution of derived allele frequencies among sampled haplotypes. The SFS is a well-studied population genetic summary statistic that is sensitive to demographic history. Inverting the map from demographic history to SFS is a notoriously ill-posed problem, in that many different population histories can have identical expected SFS (21–25). One way to deal with the ill posedness of demographic inference is to specify a parametric model of population size change, usually piecewise linear or piecewise exponential. An alternative, which generalizes to other inverse problems, is to allow a more general space of solutions but to regularize by penalizing histories that contain biologically unrealistic features (e.g., high-frequency population size oscillations). Both approaches shrink the set of feasible solutions to the inverse problem so that it becomes well posed and can be thought of as leveraging prior knowledge. In particular, regularization constrains the population size from changing on arbitrarily small timescales since significant population size change usually takes at least a few generations.In this paper, we extend a coalescent framework for demographic inference to accommodate inference of the MuSH from an SFS that is resolved into different local k-mer nucleotide contexts. This is a richer summary statistic that we call the k-SFS where, for example, k=3 means triplet context. We show using coalescent theory that the k-SFS is related to the MuSH by a linear transformation while depending nonlinearly on the demographic history. We infer both demographic history and MuSH by optimizing a cost that balances a data-fitting term using the forward map from coalescent theory, along with regularization terms that favor solutions with low complexity. Our open-source software mushi (mutation spectrum history inference) is available in ref. 26 as a Python package with extensive documentation. Using default settings and modest hardware, mushi takes only a few seconds to infer histories from population-scale sample frequency data.The recovered MuSH is a rich object that illuminates dimensions of population history and addresses biological questions about the evolution of the mutation process. After validating with data simulated under known histories, we use mushi to independently infer histories for each of the 26 populations (from 5 superpopulations defined by continental ancestry) from the 1000 Genomes Project (1KG) Consortium (27) using recent high-coverage sequencing data (28). We demonstrate that mushi is a powerful tool for demographic inference that has several advantages over existing demographic inference methods and then go on to describe the illuminated features of human MuSH.We recover demographic features that are robust to regularization parameter choices, including the out-of-Africa event and the more recent bottleneck in the ancestors of modern Finns, and we find that effective population sizes converge ancestrally within each superpopulation, despite being inferred independently. Decomposing human MuSH into mutation signatures varying through time in each population, we see global divergence in the mutation process that impacts many mutation types and reflects population and superpopulation relatedness. Finally, we revisit the timing of a previously reported ancient pulse of elevated TCC → TTC mutation rate, active primarily in the ancestors of Europeans and absent in East Asians (6, 7, 29, 30). We find that the extent of the pulse into the ancient past is sensitive to the choice of demographic history model but that all demographic models that fit the k-SFS yield a pulse timing that is significantly older than previously thought, seemingly arising near the divergence time of East Asians and Europeans.With mushi, we can quickly reconstruct demographic history and MuSH without strong model specification requirements. This adds an approach to the toolbox for researchers interested only in demographic inference. For researchers studying the mutation spectrum, demographic history is necessary for time calibration of events in mutation history, so we expect that jointly modeling demography and MuSH will be important for studying mutational spectrum evolution in population genetics.     

北京市5445件非诉讼医疗纠纷大样本分析

北京市医疗纠纷人民调解委员会从2011年5月31日至2014年8月25日共调解结案5445件医疗纠纷。5445件医疗纠纷中：急险约占3.5%,手术操作过失占比约为15.6%,围手术期处理缺陷占6.7%,告知缺陷占3.1%,误诊误治、漏诊、诊断错误整体共占11.3%,非临床医疗纠纷（包括病历书写、管理缺陷、仪器设备缺陷、违规执业）占比2.83%。对5445件调解结案的医疗纠纷进行大样本分析,利于合理认知我国医疗纠纷现状。     

Storage temperature and differing methods of sample preparation in the measurement of urinary albumin

Summary Microalbuminuria is a predictor of persistent proteinuria, renal failure and cardiovascular disease and therefore accurate determination of urinary albumin concentration is important. We examined the stability of albumin in urine under different conditions of storage, temperature and sample preparation. There was no significant difference in urinary albumin concentration between fresh urine and urine stored at either 4°C or 20°C for up to 7 days. Similarly in urine samples from diabetic patients there was no significant difference in albumin concentration at levels ranging from 1.3 to 1999.3 mg/l between fresh urine at 4°C and urine stored frozen for 1 week, 1 month or 6 months. Neither storage temperature (−20°C or −40°C) nor centrifugation of sample prior to assay made a significant difference to the albumin concentration. Multiple freezing and thawing of urine samples during 6 weeks of storage at −20°C made no difference to albumin concentrations. Storage of urine samples in either polypropylene, polystyrene or borosilicate glass tubes did not result in a significant change in urinary albumin concentration after either 1 week or 1 month at −20°C although, after 1 month of storage, urinary albumin concentrations tended to be lower by an average of approximately 7%. In tubes to which gelatine had been added this was reduced to 4%. We conclude that fresh urine can be kept at 4°C or 20°C for up to 7 days. Frozen urine samples can be stored for up to 6 months before assay without any loss of albumin concentration. Polypropylene, polystyrene or borosilicate glass tubes are acceptable containers for short-term storage and samples can simply be thoroughly thawed and vortex mixed immediately prior to assay.     

Defining Optimal Self-Management in Osteoarthritis: Racial Differences in a Population-Based Sample

The aim of this study was to examine optimal self-management in osteoarthritis and its association with patient-reported outcomes. We recruited a population-based sample of Medicare beneficiaries (n = 551) residing in Allegheny County, PA, USA and elicited an expanded set of self-management behaviors using open-ended inquiry. We defined optimal self-management according to clinical recommendations, including use of hot compresses on affected joints, alteration of activity, and exercise. Only 20% practiced optimal self-management as defined by two or more of these criteria. Optimal and suboptimal self-managers did not differ in sociodemographic features. Both white and African–Americans who practiced optimal self-management reported significantly less pain, but the benefit was greatest in severe disease for whites and for mild-moderate disease among African–Americans. This backdrop of naturally occurring self-management behaviors may be important to recognize in planning programs that seek to bolster self-management skills.