ℋ︁∞ control of discrete‐time Markov jump systems with bounded transition probabilities

This paper deals with the class of discrete‐time linear systems with random abrupt changes and unknown transition probabilities but varying between known bounds for each mode. The ℋ︁_∞ control problem of this class of systems is revisited and new sufficient conditions are developed in the linear matrix inequality (LMI) setting to design the state‐feedback controller that stochastically stabilizes the system under consideration and at the same time guarantees the disturbance rejection with a desired level γ . Sufficient conditions for existence of the state‐feedback controller are developed. It is shown that the addressed problem can be solved if the corresponding developed LMIs are feasible. Numerical examples are employed to show the usefulness of the proposed results. Copyright © 2008 John Wiley & Sons, Ltd.     

MicroRNA-224在肝癌HepG2细胞中的表达及其靶基因的预测分析

目的 应用基因芯片技术研究microRNA-224在肝癌HepG2细胞中的表达,通过生物信息学预测其下游靶基因,并初步揭示其在肝癌发生过程中的作用.方法 利用基因芯片技术筛选得到和正常肝上皮LO2细胞比较差异表达的基因,通过生物信息学预测表达上调的microRNA-224的靶基凶,并对其靶基因进行功能注释.结果 与LO2细胞比较,microRNA-224在肝癌HepG2细胞中旱高表达.MicroRNA-224预测靶基因有264个,其多个基因涉及细胞周期、信号转导、细胞增殖、细胞分化和细胞凋亡等众多生物学过程.结论 MicroRNA-224在肝癌HepG2细胞中呈现高表达,可能间接或直接地调控其下游靶基因表达,在肝癌发生过程中起着重要的作用.     

L2‐L∞ filtering for a class of stochastic nonlinear systems with aperiodic sampling

This work investigates the problem of L₂‐L_∞ filtering for a class of stochastic nonlinear systems with nonuniform sampling. The sampled‐data filter developed in this paper is an impulsive differential system whose states change abruptly at every sampling instant. The resulting filtering error system is modeled as a stochastic nonlinear impulsive differential system. The goal is to propose a method for designing a target filter that ensures the stochastic asymptotic stability of the filtering error system and guarantees a prescribed L₂‐L_∞ performance. Based on a time‐varying Lyapunov functional, by virtue of a convex combination technique, a design method to achieve such a filter is formulated in the form of solving a set of linear matrix inequalities. The effectiveness of the proposed filtering strategy is shown via a numerical example of a stochastic Chua's circuit system.     

The glyceryl [14C]tripalmitate breath test: a reassessment

Several reports have been published commending the use of 14C-labelled triglyceride breath tests in the assessment of fat malabsorption. We report further studies using gyceryl [14C]tripalmitate. Corrections for age, weight or metabolic rate failed to improve the test's ability to discriminate between malabsorbers and control subjects. A correction for respiratory quotient improved the linear correlation observed between the breath test results and daily faecal fat excretion. The significance of these findings is discussed and a number of problems identified which, at present, are preventing the introduction of breath tests for fat malabsorption into routine clinical practice.     

Up-regulation of miR-181a in clear cell renal cell carcinoma is associated with lower KLF6 expression,enhanced cell proliferation,accelerated cell cycle transition,and diminished apoptosis

Objectives

Dysregulated expression of miR-181a accompanies tumorigenesis in many human cancers. However, in clear cell renal cell carcinoma (ccRCC), the role of miR-181a remains unclear. The aim of this study was to investigate biological functions of miR-181a and its expression levels in ccRCC tissues and cancer cell lines.

Identification of men with low-risk biopsy-confirmed prostate cancer as candidates for active surveillance

Background

A combined clinical cell-cycle risk (CCR) score that incorporates prognostic molecular and clinical information has been recently developed and validated to improve prostate cancer mortality (PCM) risk stratification over clinical features alone. As clinical features are currently used to select men for active surveillance (AS), we developed and validated a CCR score threshold to improve the identification of men with low-risk disease who are appropriate for AS.

Public entrance accessibility: Psychometric approach to the development of a new assessment instrument

BackgroundThe accessibility of public facilities for all is an issue increasingly gaining focus in policy debates, especially regarding the ageing population.ObjectiveThis paper describes a psychometric approach to the development of a new instrument for assessing the accessibility of public entrances.MethodsItems to include were selected by means of literature review and classified according to a typology of person-environment fit that uses the International Classification of Functioning, Disability and Health (ICF) as theoretical framework. Content validity was assessed by a scientific panel approach and construct validity by using simulation techniques and correlation analysis with a related construct. Reliability was evaluated by inter-rater agreement analysis, where 15 strategically selected public entrances were assessed by five rater pairs.ResultsContent validity was assessed as high (3.6 on a scale from 1 to 4) and correlation indicating convergent validity between instrument scores and a related construct was moderate (r_s = 0.60, p < 0.001). Inter-rater reliability was acceptable to good (kappa 0.42, overall agreement 81%). After an iterative process including review of validity and reliability results, the resulting assessment instrument consisted of 56 items in 7 sections.ConclusionsThis study demonstrated good content validity and acceptable to good inter-rater reliability. Though initial results were promising, user involvement and further testing of construct validity is needed. The goal of the new instrument is a feasible tool for planning, evaluation and accomplishment of policies intended to make public entrances accessible for all. The extent to which the instrument succeeds remains to be tested by practical use.     

Silencing LINC01234 represses pancreatic cancer progression by inhibiting the malignant phenotypes of pancreatic cancer cells

ObjectivePrevious works have outlined the pivotal involvement of long intergenic non-coding RNA (lincRNA) in cancer progression, while the efficiency of LINC01234 in pancreatic cancer remained obscure. The purpose of this research is to unravel the regulatory mechanism of LINC01234 in pancreatic cancer via modulating microRNA (miR)-513a-3p and hexose 6-phosphate dehydrogenase (H6PD).MethodsPancreatic cancer cells were cultured and clinical tissue specimens were collected. LINC01234, miR-513a-3p and H6PD levels in pancreatic cancer cells and tissues were examined. Plasmids altering LINC01234, miR-513a-3p and H6PD expression were transfected into pancreatic cancer cells to assess the change in biological behaviors of pancreatic cancer cells. The targeting relations among LINC01234, miR-513a-3p and H6PD were validated.ResultsLINC01234 and H6PD levels were elevated while miR-513a-3p level was reduced in pancreatic cancer cells and tissues. LINC01234 deficiency hindered the malignant biological activities of pancreatic cancer cells. MiR-513a-3p depletion or H6PD elevation could abrogate the inhibitory effects of LINC01234 silencing on pancreatic cancer cells. LINC01234 sponged miR-513a-3p that targeted H6PD.ConclusionThe reduced LINC01234 exerts inhibitory impacts on pancreatic cancer cells via targeting miR-513a-3p to restrain H6PD level. The current study broadens the understanding of LINC01234 function and affords novel therapeutic targets for pancreatic cancer treatment.     

miR-451对胶质瘤细胞株A172生物学特征的影响

目的 研究miR-451对胶质瘤细胞株A172生物学特征的影响.方法 合成寡核苷酸miR-451拟似物(miR-451 mimics)转染胶质瘤细胞以上调miR-451的表达,real-time PCR检测转染后miR-451的表达,Western印迹法检测目标蛋白表达,应用流式细胞术、MTT法评价细胞生长和增殖的生物学特征变化.结果 转染miR-451 mimics后,real-time PCR检测提示miR-451表达升高,Western blot结果显示癌基因C-myc表达下降＞63.6%,细胞周期正向调节因子CDK2、CDK4、Cyclin D1和Cyclin E表达下降;细胞周期分析表明miR-451 mimics组进入G0/G1期的细胞数较对照组增多达17.4%,出现G0/G1期阻滞;MTT法分析显示miR-451 mimics组细胞生长受抑.结论 miR-451可以抑制人脑胶质瘤细胞生长和增殖能力,具有抑瘤作用.     

microRNA-1是不稳定性心绞痛的血清标志物

目的:MicroRNA正常稳定存在于循环血液中,并参与到某些特定的疾病比如心血管疾病的发生发展中,此项研究的目的就在于评价MicroRNA-1在不稳定心绞痛中是否可以作为血清诊断标志物。方法:采用多聚poly(A)尾反转录后荧光定量PCR的方法测定16个不稳定心绞痛病人及11个健康对照者的血清miR-1水平。结果:血清miR-1水平在不稳定心绞痛组较健康对照组升高516.4%。结论:我们的研究提示血清miR-1可能是不稳定心绞痛的血清标志物。