There's plenty of time for evolution

Objections to Darwinian evolution are often based on the time required to carry out the necessary mutations. Seemingly, exponential numbers of mutations are needed. We show that such estimates ignore the effects of natural selection, and that the numbers of necessary mutations are thereby reduced to about K log L, rather than K^L, where L is the length of the genomic “word,” and K is the number of possible “letters” that can occupy any position in the word. The required theory makes contact with the theory of radix-exchange sorting in theoretical computer science, and the asymptotic analysis of certain sums that occur there.     

兰州市蝇类种群调查和防治效果研究

目的掌握兰州市蝇类种群分布与季节消长等变化规律,为蝇类预防控制提供科学依据。方法采用诱蝇笼法和现场试验。结果兰州市蝇类分属3科5属7种,家蝇为优势种群占74．16％,年平均蝇密度3．21只／笼,蝇密度高峰在5～7月。环卫乐乳油和灭蝇灵颗粒毒饵对蝇类杀灭率达90％以上。结论蝇类种群与孳生物的种类、数量以及气温有很大关系,应采取综合防治措施来有效控制蝇类。环卫乐乳油和灭蝇灵颗粒毒饵对蝇类杀灭效果较为理想。     

成都地区居室庭院有害蚂蚁的调查研究

目的对成都地区居室庭院环境中的有害蚂蚁种类进行调查,以便有针对性地采取防治措施。方法采集居室庭院环境中的有害蚂蚁种类并鉴定,分析其种类组成和分布。结果发现入侵居室为害的有害蚂蚁种类3个亚科8属15种,成都市区有害蚂蚁种类明显多于成都地区其他区、市、县。印度大头蚁、史氏盘腹蚁和亮立毛蚁的分布最广。结论亟需采取措施对印度大头蚁、史氏盘腹蚁和亮立毛蚁等几种广泛分布的有害蚂蚁种类进行控制。     

Plasma pharmacokinetics,tissue distribution and excretion study of 6-gingerol in rat by liquid chromatography–electrospray ionization time-of-flight mass spectrometry

A rapid resolution liquid chromatography coupled with electrospray ionization (ESI) time-of-flight mass spectrometry method was developed and validated for quantitative analysis of 6-gingerol in plasma and various tissues. Liquid–liquid extraction was employed as sample preparation technique. Biological samples were separated on an Agilent Zorbax StableBond-C₁₈ column (4.6 mm × 50 mm, 1.8 μm) and detected by TOF/MS with electrospray ionization (ESI) interface in positive ion mode. Calibration curves (1/x² weighted) offered satisfactory linearity (r² > 0.995) within the test range. The lower limit of quantification in different matrices was in a range of 10–100 ng/mL. Inter- and intra-day precision were in the range of 0.91–11.90% and 0.75–10.23%, respectively. Recoveries in plasma, urine and tissues ranged from 72.5% to 90.4%. Glucuronide of 6-gingerol, the major metabolite of 6-gingerol, was further determined after β-glucuronidase hydrolyzation. This developed method was successfully applied to pharmacokinetics, tissue distribution and excretion studies of 6-gingerol after oral or intraperitoneal administration in rats.     

莫昔沙星滴眼剂兔眼内组织分布及其药动学研究

目的:探讨莫昔沙星滴眼剂兔眼内组织分布及药动学。方法:将27只兔均分为9组,双眼滴0.2%莫昔沙星滴眼液100μL,分别于给药后0.125、0.25、0.5、1.0、2.0、3.0、4.0、6.0、8.0 h取样,采用高效液相色谱法测定泪液、角膜、房水、虹膜-睫状体、晶体和玻璃体组织中药物浓度,以3p97程序计算药动学参数。结果:泪液、角膜、房水、虹膜睫状体、晶体和玻璃体组织中最高药物浓度分别为(76.90±28.11)、(7.68±4.18)、(1.56±0.46)、(1.00±0.42)、(0.065±0.020)、(0.030±0.014)μg·g~(-1)或μg·mL~(-1);各组织中t_(1/2β)分别为(3.59±1.81)、(4.83±3.41)、(1.80±0.56)、(4.57±3.68)、(2.36±0.65)、(2.98±2.52)h; AUC_(0(?))分别为(75.95±17.57)、(10.68±1.57)、(2.30±0.44)、(2.86±0.42)、(0.74±0.38)、(0.086±0.042)μg·h·g(-1)或μg·h·mL~(-1)。结论:莫昔沙星易于渗透到眼内各组织,且有较高浓度。     

Biochemical and behavioural characterization of EMPA,a novel high-affinity,selective antagonist for the OX2 receptor

Background and purpose:

The OX₂ receptor is a G-protein-coupled receptor that is abundantly found in the tuberomammillary nucleus, an important site for the regulation of the sleep-wake state. Herein, we describe the in vitro and in vivo properties of a selective OX₂ receptor antagonist, N-ethyl-2-[(6-methoxy-pyridin-3-yl)-(toluene-2-sulphonyl)-amino]-N-pyridin-3-ylmethyl-acetamide (EMPA).

Experimental approach:

The affinity of [³H]EMPA was assessed in membranes from HEK293-hOX₂-cells using saturation and binding kinetics. The antagonist properties of EMPA were determined by Schild analysis using the orexin-A-or orexin-B-induced accumulation of [³H]inositol phosphates (IP). Quantitative autoradiography was used to determine the distribution and abundance of OX₂ receptors in rat brain. The in vivo activity of EMPA was assessed by reversal of [Ala¹¹,D-Leu¹⁵]orexin-B-induced hyperlocomotion during the resting phase in mice and the reduction of spontaneous locomotor activity (LMA) during the active phase in rats.

Key results:

[³H]EMPA bound to human and rat OX₂-HEK293 membranes with K_D values of 1.1 and 1.4 nmol·L⁻¹ respectively. EMPA competitively antagonized orexin-A-and orexin-B-evoked accumulation of [³H]IP at hOX₂ receptors with pA₂ values of 8.6 and 8.8 respectively. Autoradiography of rat brain confirmed the selectivity of [³H]EMPA for OX₂ receptors. EMPA significantly reversed [Ala¹¹,D-Leu¹⁵]orexin-B-induced hyperlocomotion dose-dependently during the resting phase in mice. EMPA, injected i.p. in rats during the active phase, reduced LMA dose-dependently. EMPA did not impair performance of rats in the rotarod procedure.

Conclusions and implications:

EMPA is a high-affinity, reversible and selective OX₂ receptor antagonist, active in vivo, which should prove useful for analysis of OX₂ receptor function.     

血管紧张素转换酶抑制剂对心力衰竭患者细胞因子干预作用的研究进展

充血性心力衰竭（congestive heart failure,CHF）是多种心血管疾病所致的一种临床综合征,其病理生理机制除交感神经系统（sympathetic nervous system,SNS）和肾素-血管紧张素-醛固酮系统（rennin-angiotensin-aldosterone system,RAAS）的激活外,细胞因子的激活和失衡也参与了CHF的发生发展过程。有研究证实,血管紧张素转换酶抑制剂（angiotensin convertingenzyme inhibiter,ACEI）不但能阻断SNS及RAAS的激活,还能调整细胞因子网络的失衡,逆转心室肥厚以及防止和延缓心室重构,有助于延缓、遏止CHF进展。本文总结了ACEI对CHF患者血清炎症细胞因子的干预作用的研究现状,探讨通过此途径治疗CHF的效果。     

肠癌患者中医基本证候的临床调查分析

目的：探讨肠癌患者中医证候的临床分布规律。方法：对311例肠癌患者进行临床流行病学调查,组织专家组对其进行辨证,对患者正虚和邪实类基本证候的出现频率进行统计。结果：正虚类证候中,以脾气虚、脾胃虚弱、阴虚（火旺）、肝阴虚和肾阴虚证候为主;邪实类证候中以痰浊流注、血瘀、血热、肝气郁滞、湿（痰）浊内生、湿热内蕴、胃肠积热为主。结论：肠癌中医基本证候分布具有一定的规律性。     

肿瘤标志物在乳腺肿瘤诊断价值的探讨

目的探讨肿瘤标志物在乳腺肿瘤诊断的价值。方法对162例乳腺恶性肿瘤（A组）、34例乳腺良性肿瘤（B组）、78例健康成人（C组）进行血清CA15-3、CA19-9、CA24-2、CA125和CEA五项指标的检测,并进行对比分析。结果（1）5种肿瘤标志物在A组的阳性分布高于B组和C组（P〈0.01）;（2）5种肿瘤标志物对乳腺恶性肿瘤诊断的阳性率为：越晚期的恶性肿瘤各标志物的阳性率越高;（3）5种标志物联合检测提高诊断的阳性率;（4）乳腺恶性肿瘤术后或化疗可使各项标志物的水平降低。结论血清CA15-3、CA19-9、CA24-2、CA125和CEA五项肿瘤标志物在乳腺恶性肿瘤的阳性分布高,手术或化疗可使肿瘤标志物水平下降。     

Effect of Fire on Pools of Mercury in Forest Soil,Central Europe

In year 2006, 17.9 ha of forest was burned during a forest fire at the Bohemian Switzerland National Park found in northern part of Czech Republic (CR), central Europe. Complete combustion of organic soil (4,039 t) on the burned area caused volatilization of 1.34 ± 0.07 kg of Hg. Thus Hg emissions due to fire amounted to 75.1 g ha⁻¹. The average burned forested areas in CR for the period 2000–2006 were reported at 356 ha with estimated Hg emissions at 26.7 kg year⁻¹, while the average anthropogenic emissions in the same period amounted to 3 t year⁻¹. Thus estimated mean emissions of Hg from burned forest soil in the period 2000–2006 reached 1% of the annual anthropogenic Hg emissions.