FTIR-ATR结合膜富集技术测定中药材地龙中微量铜的含量

目的 利用傅里叶变换-衰减全反射红外光谱(FTIR-ATR)结合膜富集技术,建立中药材地龙中微量铜质量分数的快速、经济的测定方法.方法 首先,对30批校正集样品进行湿法消解,利用铜与金属络合剂1-(2-吡啶偶氮)-2-萘酚(PAN)发生络合反应,优化各种反应条件,包括pH 、PAN用量、反应时间.再将络合物抽滤富集在微孔滤膜上,采集其FTIR-ATR光谱,经9点平滑、一阶导数9点平滑等预处理后,利用随机森林回归算法建立其铜质量分数的定量校正模型.校正集按3∶1随机分配为训练集和测试集,对模型进行参数优化和评价.利用优化后模型预测广东、广西和福建3个产地地龙样品中铜的质量分数,并与ICP-MS测定结果进行比较.结果 最优模型预测3个产地地龙样品的质量分数在5.85～6.98 mg/kg之间,与ICP-MS分析结果相比,相对误差均小于20％.结论 本方法利用膜富集技术提高了FTIR-ATR的检测灵敏度,为中药材重金属元素的定量分析提供了一种新方法.     

Superoxide dismutases of heavy metal resistant streptomycetes

Heavy metal tolerant and resistant strains of streptomycetes isolated from a former uranium mining site were screened for their superoxide dismutase expression. From the strains tolerating high concentrations of different heavy metals, one was selected for its tolerance of concentrations of heavy metals (Ni, Cu, Cd, Cr, Mn, Zn, Fe). This strain, Streptomyces acidiscabies E13, was chosen for the purpose of superoxide dismutase analysis. Gel electrophoresis and activity staining revealed only one each of a nickel (NiSOD) and an iron (FeZnSOD) containing superoxide dismutase as shown by differential enzymatic repression studies. The gene for nickel containing superoxide dismutase, sodN, was cloned and sequenced from this strain. The genomic sequence shows 92.7% nucleotide identity and 96.1% amino acid identity to sodN of S. coelicolor. Expression can be activated by nickel as well as other heavy metals and active enzyme is produced in media lacking nickel but containing copper, iron or zinc. Thus, the selected strain is well suited for further characterization of the enzyme encoded by sodN.     

Cyclooxygenase enzyme expression and E series prostaglandin receptor signalling are enhanced in heavy menstruation

BACKGROUND: Although the mechanisms underlying the causes of heavy menstrualblood loss (MBL) remain to be elucidated, prostaglandins havebeen previously implicated. This study was initiated to elucidatea pattern of expression of the various components of the cyclooxygenase(COX)–prostaglandin signalling pathways present in theendometrium of women with normal and heavy MBLs. METHODS: Endometrial biopsies were collected at different stages of themenstrual cycle from women who underwent measurement of MBL.Tissue was divided for either examination of gene expressionby quantitative RT–PCR analysis or in vitro culture experimentation. RESULTS: Analysis of gene expression demonstrated a significant elevationin expression of COX-1 and COX-2 mRNA in endometrium obtainedfrom women with heavy MBL when compared with endometrium obtainedfrom women with normal MBL. Tissue culture with PGE₂ stimulationcaused a significantly elevated production of cyclic AMP (cAMP)by endometrium of women with heavy MBL when compared with normalMBL. Expression of phosphodiesterase 4B, an enzyme involvedin cAMP breakdown, was reduced in these same endometrial samplesobtained from women with heavy MBL. CONCLUSIONS: These data identify the E series prostaglandin receptors andtheir signalling pathways as potential therapeutic targets inthe treatment of heavy menstruation.     

Personal Income and Substance Use among Emerging Adults in the United States

Background: Taxation and other policy measures have been implemented across the United States to curb the accessibility of substance use, especially among youth. While the inverse relationship between price and youth consumption is well known, available research on youth earned income and substance use is sparser, particularly among emerging adults. Objectives: We examined the association between emerging adult past-year personal income and 30-day substance use. Methods: We analyzed data from Wave 5 (n = 2,202) of the NEXT Generation Health Study, an annual survey study administered to a nationally representative sample of emerging adults in the U.S. Wave 5 (mean age = 20.28 years, SE = 0.02 years) was administered during the 2013–2014 academic year. After grouping participants into five levels of self-reported, pre-tax personal income, we used binomial logistic regression to examine the association between personal income and cigarette smoking, marijuana use, alcohol use, and heavy episodic drinking (HED). Results: In unadjusted models, those at certain levels of higher past-year income were more likely to smoke cigarettes, consume alcohol, or engage in HED at least once in the past 30 days. Several associations remained significant after controlling for covariates. Most associations were no longer significant after including perceived peer norms as additional covariates. Personal income was not associated with 30-day marijuana use in unadjusted or adjusted models. Conclusions/Importance: Higher earned income may provide emerging adults greater economic access to cigarettes and alcohol, but the association might be partly attenuated by social factors, particularly perceived peer norms.     

Parametric models for biomarkers based on flexible size distributions

Recent advances in social science surveys include collection of biological samples. Although biomarkers offer a large potential for social science and economic research, they impose a number of statistical challenges, often being distributed asymmetrically with heavy tails. Using data from the UK Household Panel Survey, we illustrate the comparative performance of a set of flexible parametric distributions, which allow for a wide range of skewness and kurtosis: the four‐parameter generalized beta of the second kind (GB2), the three‐parameter generalized gamma, and their three‐, two‐, or one‐parameter nested and limiting cases. Commonly used blood‐based biomarkers for inflammation, diabetes, cholesterol, and stress‐related hormones are modelled. Although some of the three‐parameter distributions nested within the GB2 outperform the latter for most of the biomarkers considered, the GB2 can be used as a guide for choosing among competing parametric distributions for biomarkers. Going “beyond the mean” to estimate tail probabilities, we find that GB2 performs fairly well with some disparities at the very high levels of glycated hemoglobin and fibrinogen. Commonly used linear models are shown to perform worse than almost all the flexible distributions.     

湖南省湘资沅澧四大流域管网末梢水中重金属的健康风险评价

目的了解湖南省湘资沅澧流域管网末梢水中八种重金属的污染状况,对其产生的健康风险进行评价。方法本研究对2014年湖南省湘、资、沅、澧流域管网末梢水中砷、镉、六价铬、铅、汞、硒、锰、锌(As、Cd、Cr^(6+)、Pb、Hg、Se、Mn、Zn)的含量进行检测,并进行健康风险评价。结果八种重金属在丰水期和枯水期的含量均未超过国标限值。四大流域中,仅湘江流域的As、Cd和丰水期的Cr^(6+),致癌风险稍高于限值,其余的致癌风险值均小于10^(-4),但四种重金属合计致癌风险在丰水期为1.32×10^(-4),枯水期为1.50×10^(-4),稍高于限值10^(-4)。全流域As、Cd、Cr^(6+)、Hg、Se、Mn、Zn的单独及合计非致癌风险在丰水期和枯水期均小于1。重金属所致非致癌风险和致癌风险在不同水期和不同流域差异有统计学意义(P<0.05)。结论湖南省湘资沅澧流域管网末梢水中重金属的联合污染可能对人群产生健康风险,建议相关地区卫生和环保部门重视四大流域内的重金属污染。     

参丹活血胶囊联合DP方案治疗不可切除的老年晚期卵巢腺癌的临床研究

目的探讨参丹活血胶囊联合DP方案(多西他赛注射液和顺铂注射液)治疗不可切除的老年晚期卵巢腺癌的临床疗效。方法选取2016年1月—2017年5月绵阳市中心医院收治的不可切除的老年晚期卵巢腺癌患者82例为研究对象,采用随机数字表法将所有患者分为对照组和治疗组,每组各41例。对照组患者给予DP方案治疗,第1天静脉滴注多西他赛注射液,75 mg/m2;第1~3天静脉滴注顺铂注射液,70 mg/m2。治疗组在对照组治疗的基础上口服参丹活血胶囊,6粒/次,3次/d。每个疗程3周,两组患者均连续治疗4个疗程。评价两组患者近期临床疗效,同时比较治疗前后的生活质量评分、免疫功能指标和毒副反应。结果治疗后,对照组和治疗组的客观缓解率分别为60.9%、78.0%,疾病控制率分别为43.9%、58.5%,两组近期临床疗效比较差异有统计学意义(P0.05)。治疗后,两组功能状况评分、社会状况评分均显著升高,附加关注评分、情感状况评分、生理状况评分均显著降低,同组治疗前后比较差异具有统计学意义(P0.05);且治疗后治疗组生活质量评分改善情况明显优于对照组,两组比较差异具有统计学意义(P0.05)。治疗后,治疗组免疫球蛋白G(IgG)、免疫球蛋白M(IgM)、免疫球蛋白A(IgA)、CD3~+和CD4~+均显著增高,同组治疗前后比较差异具有统计学意义(P0.05);且治疗后治疗组免疫指标明显高于对照组,两组比较差异具有统计学意义(P0.05)。治疗期间,治疗组各项毒副反应发生率均显著低于对照组,两组比较差异具有统计学意义(P0.05)。结论参丹活血胶囊联合DP方案治疗不可切除的老年晚期卵巢癌具有较好的临床疗效,能够有效改善患者生活质量和免疫功能,毒副作用小,具有一定的临床推广应用价值。     

Short-term inhalation study of graphene oxide nanoplates

Graphene oxides possess unique physicochemical properties with important potential applications in electronics, pharmaceuticals, and medicine. However, the toxicity following inhalation exposure to graphene oxide has not yet been clarified. Therefore, this study conducted a short-term graphene oxide inhalation toxicity analysis using a nose-only inhalation exposure system and male Sprague–Dawley rats. A total of four groups (15 rats per group) were exposed: (1) control (fresh air), (2) low concentration (0.76?±?0.16?mg/m³), (3) moderate concentration (2.60?±?0.19?mg/m³), and (4) high concentration (9.78?±?0.29?mg/m³). The rats were exposed to graphene oxide for 6?h/day for 5 days, followed by recovery for 1, 3, and 21 days. No significant body or organ weight changes were noted after the short-term exposure or during the recovery period. Similarly, no significant systemic effects of toxicological importance were noted in the hematological assays, bronchoalveolar lavage fluid (BAL) inflammatory markers, BAL fluid cytokines, or blood biochemical assays following the graphene oxide exposure or during the post-exposure observation period. Moreover, no significant differences were observed in the BAL cell differentials, such as lymphocytes, macrophages, or polymorphonuclear cells. Graphene oxide-ingested alveolar macrophages as a spontaneous clearance reaction were observed in the lungs of all the concentration groups from post 1?day to post 21 days. Histopathological examination of the liver and kidneys did not reveal any significant test-article-relevant histopathological lesions. Importantly, similar to previously reported graphene inhalation data, this short-term nose-only inhalation study found only minimal or unnoticeable graphene oxide toxicity in the lungs and other organs.     

An optimal control model for cloud seeding in a deterministic and stochastic environment

To promote artificial rain in India and other such developing countries, in this article, we have proposed and analyzed a nonlinear mathematical model for cloud seeding by considering that aerosols are introduced proportional to the density of water vapors present in the atmosphere. The model is analyzed using Lyapunov's stability theory of differential equations. To reduce the cost of cloud seeding, an optimal control strategy is designed by incorporating four control parameters. We have shown the existence and uniqueness of solution of this optimal control problem, using Pontryagins Maximum Principle. To minimize the cost in making artificial rain, the optimal control problem provides the strategy for the rate of introduction of aerosols in the atmosphere. To capture the effects of environmental noise on control strategies, the model in deterministic framework is converted into stochastic framework. In this regard, the Hamilton-Jacobi-Bellman equation for stochastic control cost function has been formed. The stochastic analysis implies that the control strategy is effective in reducing the cost and increasing rainfall.