Magnetic Force Transmission of a Reciprocating Motion

Magnetic force transmission of a reciprocating motion is studied by theoretical analysis and experiment. A mathematical model for calculating the magnetic force is derived using the theory of equivalent magnetic charges. An experimental rig is constructed to test the transmission and the model is verified by experiment. Effect of the transmission parameters on the magnetic force is analyzed theoretically from the model, and characteristic of the transmission is studied experimentally. Since the transmission is without direct contact between two elements, it is suitable for application in an organism.     

Association of Serum MicroRNA Expression in Hepatocellular Carcinomas Treated with Transarterial Chemoembolization and Patient Survival

Background and Aim

Hepatocellular carcinoma (HCC) is one of the most deadly tumors. Transarterial chemoembolization (TACE) is effective for unresectable HCC. In recent years, miRNAs have been proposed as novel diagnostic and prognostic tools for HCC. This study aimed to identify whether microRNAs (miRNAs) can serve as biomarkers to reliably predict outcome before HCC patients are treated with TACE.

Methods

Eleven miRNAs (miR-, miR-19a, miR-101-3p, miR-199a-5p, miR-200a, miR-21, miR-214, miR-221, miR-222, miR-223 and miR-, -5p) were quantified by quantitative real-time PCR (qRT-PCR) in 136 HCC patients’ serum before they received TACE therapy. Univariate and multivariate analysis were used to identify the prognostic value of clinical parameters and miRNAs. Area under the receiver operating characteristic curve (AUC) was used to evaluate the prediction potency.

Results

The levels of some miRNAs were dramatically associated with clinicopathologic features regarding Child-Puge class, AFP, tumor size and satellite nodules. Univariate analysis revealed that miR-200a, miR-21, miR-122 and miR-224-5p were significantly associated with patients’ survival. Multivariate analysis demonstrated that AFP, satellite nodules and miR-200a were the independent prognostic factors associated with survival in this cohort (p = 0.000, 0.001, 0.000, respectively). The probability of the prognostic accuracy of miR-200a was 81.64% (74.47% specificity and 88.76% sensitivity), which was higher than the classifier established by combination of AFP and satellite nodules (76.87% probability, 70.21% specificity and 69.66% sensitivity). Furthermore, the combination of AFP, satellite nodules and miR-200a demonstrated as a classifier for HCC prognosis, yielding a ROC curve area of 88.19% (93.62% specificity and 68.54% sensitivity).

Conclusions

Our study indicated that serum miR-200a may prognosticate disease outcome in HCC patients with TACE therapy. Therefore, miR-200a can potentially guide individualized treatment for HCC patients with a high risk of TACE treatment failures.     

Adenovirus gene transfer to amelogenesis imperfecta ameloblast-like cells

To explore gene therapy strategies for amelogenesis imperfecta (AI), a human ameloblast-like cell population was established from third molars of an AI-affected patient. These cells were characterized by expression of cytokeratin 14, major enamel proteins and alkaline phosphatase staining. Suboptimal transduction of the ameloblast-like cells by an adenovirus type 5 (Ad5) vector was consistent with lower levels of the coxsackie-and-adenovirus receptor (CAR) on those cells relative to CAR-positive A549 cells. To overcome CAR -deficiency, we evaluated capsid-modified Ad5 vectors with various genetic capsid modifications including "pK7" and/or "RGD" motif-containing short peptides incorporated in the capsid protein fiber as well as fiber chimera with the Ad serotype 3 (Ad3) fiber "knob" domain. All fiber modifications provided an augmented transduction of AI-ameloblasts, revealed following vector dose normalization in A549 cells with a superior effect (up to 404-fold) of pK7/RGD double modification. This robust infectivity enhancement occurred through vector binding to both α(v)β3/α(v)β5 integrins and heparan sulfate proteoglycans (HSPGs) highly expressed by AI-ameloblasts as revealed by gene transfer blocking experiments. This work thus not only pioneers establishment of human AI ameloblast-like cell population as a model for in vitro studies but also reveals an optimal infectivity-enhancement strategy for a potential Ad5 vector-mediated gene therapy for AI.     

南亚药用植物概述

简介了南亚药用植物的总体情况,30种重要种类的产地、药用部位、活性成分、功效,以及常用种类的简要情况。     

Elongator complex influences telomeric gene silencing and DNA damage response by its role in wobble uridine tRNA modification

Elongator complex is required for formation of the side chains at position 5 of modified nucleosides 5-carbamoylmethyluridine (ncm⁵U₃₄), 5-methoxycarbonylmethyluridine (mcm⁵U₃₄), and 5-methoxycarbonylmethyl-2-thiouridine (mcm⁵s²U₃₄) at wobble position in tRNA. These modified nucleosides are important for efficient decoding during translation. In a recent publication, Elongator complex was implicated to participate in telomeric gene silencing and DNA damage response by interacting with proliferating cell nuclear antigen (PCNA). Here we show that elevated levels of tRNA^Lys _{s² UUU}, tRNA^Gln _{s² UUG}, and tRNA^Glu _{s² UUC}, which in a wild-type background contain the mcm⁵s²U nucleoside at position 34, suppress the defects in telomeric gene silencing and DNA damage response observed in the Elongator mutants. We also found that the reported differences in telomeric gene silencing and DNA damage response of various elp3 alleles correlated with the levels of modified nucleosides at U₃₄. Defects in telomeric gene silencing and DNA damage response are also observed in strains with the tuc2Δ mutation, which abolish the formation of the 2-thio group of the mcm⁵s²U nucleoside in tRNA^Lys _mcm⁵s²UUU, tRNA^Gln _mcm⁵s²UUG, and tRNA^Glu _mcm⁵s²UUC. These observations show that Elongator complex does not directly participate in telomeric gene silencing and DNA damage response, but rather that modified nucleosides at U₃₄ are important for efficient expression of gene products involved in these processes. Consistent with this notion, we found that expression of Sir4, a silent information regulator required for assembly of silent chromatin at telomeres, was decreased in the elp3Δ mutants.     

Increased heat shock protein 70 levels in induced sputum and plasma correlate with severity of asthma patients

Damage-associated molecular pattern molecules such as high-mobility group box 1 protein (HMGB1) and heat shock protein 70 (HSP70) have been implicated in the pathogenesis of asthma. The aim of our study was to examine the induced sputum and plasma concentrations of HSP70 in asthmatic patients to determine their relationship with airway obstruction. Thirty-four healthy controls and 56 patients with persistent bronchial asthma matched for gender and age were enrolled in this study. Spirometry measurements were performed before sputum induction. HSP70 levels in induced sputum and plasma were measured using the ELISA Kit. Sputum and plasma concentrations of HSP70 in asthmatics patients were significantly higher than that in control subjects (sputum, (0.88 ng/ml (0.27–1.88 ng/ml) versus 0.42 ng/ml (0.18–0.85 ng/ml), p < 0.001); plasma, (0.46 ng/ml (0.20–0.98 ng/ml) versus 0.14 ng/ml (0.11–0.37 ng/ml), p < 0.001) and were significantly negatively correlated with forced expiratory volume in 1 s (FEV1), FEV1 (percent predicted), and FEV1/FVC in all 90 participants and 56 patients with asthma. There were no significant differences in HSP70 levels between patients with eosinophilic and non-eosinophilic asthma. HSP70 levels in plasma were positively correlated with neutrophil count, and HSP70 levels in induced sputum were positively correlated with lymphocyte count. In multivariate analysis, independent predictors of sputum HSP70 were diseases and disease severity but not smoking, age, or gender, and independent predictors of plasma HSP70 were also diseases and disease severity. In conclusion, this study indicates that induced sputum and plasma HSP70 could serve as a useful marker for assessing the degree of airway obstruction in patients with asthma. However, further investigation is needed to establish the role of circulating and sputum HSP70 in the pathogenesis of asthma.     

沼泽湿地垦殖前后土壤温度变化及其对土壤热状况的影响

沼泽湿地具有重要的生态与环境功能,其对全球气候变化较为敏感,土壤温度变化能够很好地指示气候的波动.沼泽湿地土壤温度呈明显的"正弦曲线"型年、季动态,不同深度土壤年均温度呈"U"型特征.5～9月份沼泽湿地10 cm土壤平均温度为11.69±3.04℃,垦殖后农田土壤为1.80±3.41℃.沼泽湿地土壤8、9月份土壤呼吸分别为156.41±76.91 mg·m^-2·h^-1和116.75±57.43 m^-2·h^-1,是同时期农田土壤呼吸通量的14.6%和13.1%,土壤温度与土壤呼吸通量呈显著正相关关系.     

Water Footprint of Cereals and Vegetables for the Beijing Market

Beijing is situated in water‐scarce northern China, where there is a history of policies aimed at constraining local agricultural water use to meet the increasing urban water demand. This has led to a change in local crop production and subsequent effects in terms of the importation of cereals and vegetables grown in other parts of China. The dilemma is that local policies designed to improve Beijing's water resources situation may have the unintended consequence of increasing water stress in other regions. In this article, life cycle assessment approaches were used to model both consumptive and degradative water use for the major cereals and vegetables consumed in Beijing, enabling comparison of local and imported supplies. In the Beijing region, cropping cereals rather than intensive vegetables in greenhouses could reduce local blue water consumption by 7,216 cubic meters per hectare per year (m³ ha^?1 yr^?1) and nitrogen pollution by 45 kg ha^?1 yr^?1. However, depending on how the local food shortfall is balanced by imported food, shifts in cropping pattern in Beijing have the potential to cause either an improvement or exacerbation of the nationwide water stress situation (e.g., ?42% to 4% for water scarcity footprint). As such, local policy making regarding agricultural land and water use needs to consider the wider food production context. This situation in Beijing is likely to be representative of the challenge facing many of the world's large and mega‐sized cities, where a sustainable means of increasing food supply must be found.