基于过程模型CROBAS的全局灵敏度分析方法比较

过程机理模型在开发过程中常受限于生理学参数无法直接或准确测量.全局灵敏度分析可以评估模型预测结果对于生理学参数变化的响应,为模型结构改进、数据收集和参数校准提供参考.本研究基于过程模型CROBAS,以华山松为例,选取模型中描述树木结构关系的10个参数,以树高和各器官生物量的Nash-Sutcliffe效率(NSE)为目...     

Comments on the manna model

WANGERSKY and WANGERSKY'S (1980, 1981, 1983) Manna models on algal patchiness and competition are essentially stochastic models. Analysis of their phase-spatial properties, however, reveals complementary, deterministic features: interspecific competition is relatively ineffective because of the high degree of compartmentalization of resource supply and consumption; the probability of consumption in a given place at a given time is largely independent of the rate of consumption in other places.     

皮质酮诱导的PC12细胞梯度应激损伤模型的构建及评价

目的:建立皮质酮诱导的PC12细胞梯度应激损伤模型,为细胞应激水平的评估和细胞应激损伤调控研究提供实验基础和对象。方法:通过检测不同浓度皮质酮(0～1 000μmol/L)在经过不同干预时间(8～48 h)后PC12细胞活力,观察皮质酮对细胞活力的影响,筛选最佳干预条件的细胞模型。分光光度法和微量法检测细胞模型的关键应激指标(MDA、SOD、NADH、LDH),对模型进行评价。结果:当皮质酮浓度在200μmol/L以下且干预时间为12 h时,细胞活力在半数失活率以下,可减少各组由于细胞活力下降而产生的混杂因素。与空白对照组比较,皮质酮浓度依赖性地升高模型组的MDA、NADH和LDH水平,降低SOD水平(P<0.01),符合梯度应激模型的构建要求。结论:成功建立了PC12细胞梯度应激损伤模型,在干预时间为12 h的情况下,干预浓度为0μmol/L、25μmol/L、50μmol/L、100μmol/L、150μmol/L、200μmol/L,使得细胞模型应激损伤程度梯度增加,可作为开展细胞应激损伤评估及调控实验的基础和对象。     

The modulation of neuroinflammation by inducible nitric oxide synthase

The accumulation and propagation of misfolded proteins in the brain is a pathological hallmark shared by many neurodegenerative diseases, such as the depositions of β-amyloid and hyperphosphorylated tau proteins in Alzheimer''s disease. Initial evidence shows the role of nitric oxide synthases in the development of neurodegenerative diseases. A recent, in an exciting paper (Bourgognon et al. in Proc Natl Acad Sci USA 118, 1–11, 2021. 10.1073/pnas.2009579118) it was shown that the inducible nitric oxide synthase plays an important role in promoting oxidative and nitrergic stress leading to neuroinflammation and consequently neuronal function impairments and decline in synaptic strength in mouse prion disease. In this context, we reviewed the possible mechanisms of nitric oxide synthase in the generation of neurodegenerative diseases.     

基于三温模型的南宁市蒸散量估算及其影响因素

蒸散发是水文能量循环和气候系统的关键要素.研究蒸散发的时空变化特征及其响应气候、土地利用的变化规律,对理解城市流域水循环和生态过程效应具有重要意义.本研究基于三温模型和MODIS影像,估算并分析2001-2018年南宁市的蒸散量时空演变特征,并探讨了主要气候要素、土地利用类型对蒸散量的影响规律和驱动模式.结果表明:20...     

亚热带河口养殖塘沉积物有机碳矿化及其影响因子

亚热带河口的养殖塘是温室气体二氧化碳(CO2)的重要排放源,但其沉积物有机碳矿化动力学特征目前尚未厘清.以我国东南沿海亚热带闽江、木兰溪以及九龙江河口区的6个凡纳滨对虾(Penaeus vannamei)养殖塘为研究对象,对沉积物取样,并进行为期60 d的室内厌氧培养,对养殖塘沉积物CO2累积产量曲线利用一阶动力学模型...     

Pyroptosis in glioblastoma: A crucial regulator of the tumour immune microenvironment and a predictor of prognosis

Recent studies have shown that pyroptosis, an inflammatory form of cell death, has a dual role in tumorigenesis and tumour progression and affects the prognosis of patients; however, the role of pyroptosis in glioblastoma (GBM) is still unclear. In this study, based on GBM patients'' data from two independent cohorts, we performed a comprehensive analysis of the expression and prognostic value of 33 pyroptosis‐associated genes (PAGs) in GBM, as well as their role in the tumour immune microenvironment (TIME) of GBM. We identified 29 PAGs that were differentially expressed between GBM and normal brain tissue, 18 of which were upregulated in GBM tissue. Most of the 33 PAGs were strongly correlated with the levels of immune cell infiltration. Based on the 33 PAGs, the GBM samples can be divided into two clusters (C1‐C2), with C1 having a ‘hot’ but immunosuppressive TIME and C2 having a ‘cold’ TIME, suggesting different immunotherapeutic responses in the two clusters. In addition, we identified four PAGs that were strongly associated with GBM prognosis and constructed a risk model based on these four PAGs. This risk model is an independent prognostic factor for GBM patients, and there is a different immune status between high‐ and low‐risk groups. In conclusion, this study demonstrates that pyroptosis is closely associated with the prognosis and TIME of GBM and provides an important basis for further studies on the relationship between pyroptosis and GBM.     

基于鼠脑海马位置细胞与Q学习面向目标导航

生理学实验表明在鼠脑海马结构中存在的一种具有特异性放电特征的细胞,它在大鼠空间导航和环境认知中起着关键性作用,该特异性神经元被称之为位置细胞。本文将基于位置细胞、运动神经元来构建一种前馈神经网络模型,采用Q学习算法实现大鼠面向目标导航任务。实验结果表明该前馈神经网络模型能快速实现大鼠面向目标导航任务。     

基于肿瘤免疫微环境鉴定IDH突变型弥漫性胶质瘤的预后标志物

异柠檬酸脱氢酶(IDH)突变存在于大多数低级别胶质细胞瘤中,免疫逃逸是肿瘤标志性特征之一,免疫治疗在胶质瘤的治疗中的作用越来越重要。利用生信手段分析TCGA、CGGA、GEO数据集中IDH突变胶质瘤的770个免疫相关基因及其临床相关数据,从而获得每个患者的免疫风险评分(IMRS);结合IMRS和临床信息,筛选出6个差异表达基因(TRAF3、ATG10、BID、TAB1、MAP3K1、RPS6)组成IMRS模型并生成诺莫图对患者预后进行评估,发现低风险组患者的总生存期(OS)较高风险组均明显延长。此外,签名相关免疫细胞浸润分析发现肿瘤相关巨噬细胞浸润评分(TAM)与肿瘤相关T细胞浸润评分(TIS)呈明显的负相关,表明高IMRS富集了促肿瘤免疫浸润,而低IMRS则富集了相对较多的抗肿瘤免疫浸润。