越来越苍老的世界

中国全面推行计划生育政策,少生了3亿多人,节约了7万亿抚养费,也少了3亿可以负担养老的劳动力。由于老龄化加速,老年抚养比由1964年的6.4%上升为2002年的11.6%,离退休金平均实际递增18.9%。到2050年,中国的抚养比将可能达到70%。老龄化速度,法国用了115年,英国用了80年,美国用了60年,我国用了18年。     

远程教育培训给生物教学带来新的生机

远程教育培训给生物教学带来新的生机。夯实了专业知识,梳理了生物知识,使我认识到应该如何把握生物课堂教学,提高了课堂教学设计能力,凝聚了生物教师的力量,使老师们学到了很多知识和教学技能,解决了平时教学中的一些难题,提升了生物的教学水平。     

亚热带丘陵茶园间作白三叶的土壤环境调控效果

在亚热带丘陵区1年生幼龄茶园通过连续4年间作白三叶大田试验,研究了其对茶园土壤环境及茶叶品质、产量的影响,结果表明,茶园间作白三叶降低了土壤容重,提高了土壤孔隙度、有机质、全氮、水解氮的含量及钾的活性,消耗了部分有效磷;增加了土壤关键层次（0～20cm）和关键时期（4～6月）的水分含量,延缓和缩短了夏季高温干旱与秋季持续干旱时间;获得了土壤降温时增温、保温与升温时降温的双向动态调控效果．增加了同一层次土壤温度的稳定性,延缓了高温和低温的出现时间,缩短了过度高温时间。从而促进了茶树生长,改善了茶叶品质,显著增加了茶叶产量。与清耕茶园相比,茶园间作白三叶后,春秋茶的酚氨比分别下降了17．10％和30．90％,产量提高了32.65％。     

酷想大晒台

哎呀呀,这个世界乱套了!大人变成了小孩,小孩变成了大人。现在,终于轮到各位小酷想家来当家做主了,快来看看他们都有什么出色的表现吧!看到爸妈变成了小孩,我立马学着他们的样子,下达了第一道命令:写作业去!我想他们一定会哭的,因为老师留的作业实在是太多了。新浪YOYO     

一年又一年

上了年纪的人都有相似的感觉,就是年纪越大,时间好像过得越快。小时候,过了元旦盼春节,过了春节盼五一、六一,过了六一盼国庆,过了国庆再盼元旦。时间总是那么漫长,盼望的假期似乎总是姗姗来迟。而如今,似乎一眨眼,一年就过去了。我给这个现象总结了一个理论,叫做相对     

电镀行业重金属在线回收清洁生产技术

为了提高电镀企业水重复利用率, 降低物料单耗, 减少重金属产生量, 提升企业清洁生产水平, 通过某电镀厂清洁生产实例, 介绍了膜分离和离子交换在线回收技术的基本原理和技术特性, 计算了经济可行性, 对比了水重复利用率、物料单耗、重金属产生量三项指标。结果表明, 该技术的内部收益率大于基准收益率, 镀镍工序水重复利用率提高了60.1%, 物料单耗降低了4.51%, 废水中镍产生量每年减少360 kg, 镀铬工序水重复利用率提高了46.0%, 物料单耗降低了10.4%, 废水中Cr(VI)产生量每年减少340 kg。     

具有分布时滞传染病模型的渐近分析

本文讨论了具有一般分布函数（核）的微分方程传染病模型,给出了平衡点,讨论了稳定性,得到了阈值定理．     

砷对烤烟(Nicotiana tabacum L.)碳代谢的影响

采用盆栽试验,系统地研究了砷对烤烟全生育期碳代谢及其过程的影响,结果表明,砷降低了烤烟整个生育期的叶绿素含量、光合速率、蔗糖合成酶（SS,合成方向）活性和现蕾以后的蔗糖磷酸合成酶（SPS）活性,提高了全生育期的SS（分解方向）活性和可溶性糖含量,因而抑制了碳的同化和蔗糖的合成,促进了蔗糖的分解,不利于碳向积累方向转化。砷提高了全生育期的腺苷二磷酸葡萄糖焦磷酸化酶（ADPG-PPase）活性,增加了团棵期和现蕾期淀粉的积累,降低了团棵期和采收期的可溶性淀粉酶（SSS）活性和采收期的淀粉含量,从而导致了碳积累代谢的紊乱,最终造成碳积累的减少。     

促进微生物实验技术创新水平的改革初探

为了加强对本科生综合素质和能力的培养 ,激发学生的学习兴趣 ,我们对微生物实验课的教学内容进行了一系列改革 ,优化了实验项目 ,节约实验成本 ,并且引入科研成果转化实验 ,同时改进了实验方法和手段 ,实验结果更为准确。这些措施蕴含了较高的理论水平 ,增加了教学信息量 ,明显提高了教学效果 ,为培养高素质人才奠定了基础。     

遥感和GIS支持的土地利用动态监测研究——以黄河三角洲垦利县为例

以黄河三角洲垦利县为例,对比分析了目视解译、机助分类等遥感土地利用信息提取方法,采用1981、1991和1995年3时相土地利用现状信息,研究确定了统一的监测分类系统,提出了土地利用面积及其空间分布动态监测方法.在此基础上,分析了垦利县地类面积增减变化,在GIS支持下分析了1981～1995年土地利用空间动态变化,同时进行了实地监测点土地利用变化分析,探明了该县土地利用动态变化规律.     

Echocardiographic Findings in Patients With Normocalcemic Primary Hyperparathyroidism Compared With Findings in Hypercalcemic Primary Hyperparathyroid Patients and Control Subjects

ObjectiveThere are no data regarding echocardiographic parameters in patients with normocalcemic primary hyperparathyroidism (NCPHPT). We compared the echocardiographic findings in postmenopausal women with NCPHPT with those in patients with hypercalcemic primary hyperparathyroidism (PHPT) and controls.MethodsSeventeen consecutive Caucasian postmenopausal women with NCPHPT were compared with 20 women with hypercalcemic PHPT and 20 controls. Obesity, diabetes, kidney failure, and previous cardiovascular diseases were considered exclusion criteria. Each patient underwent biochemical evaluation, bone mineral density scan, and echocardiographic measurements. Patients with parathyroid disorders underwent kidney ultrasound evaluation.ResultsPatients with PHPT had significantly higher mean total serum calcium, ionized calcium, 24-hour urinary calcium, and parathyroid hormone and lower mean phosphorus levels compared with those in the controls (all P < .05). The only differences between patients with NCPHPT and PHPT were significantly lower mean total serum calcium, ionized calcium, and 24-hour urinary calcium and higher phosphorus levels in patients with NCPHPT (all P < .05). The only biochemical difference between patients with NCPHPT and the controls was a higher level of mean parathyroid hormone in patients with NCPHPT. There were no differences in cardiovascular risk factors between patients with NCPHPT and PHPT and the controls. Hypertension was the most frequent cardiovascular risk factor, diagnosed in 65% of patients with PHPT. This high prevalence was not statistically significant compared with that observed in patients with NCPHPT (59%) and in the controls (30%). Echocardiography parameters were not different between patients with NCPHPT and PHPT and the controls when subdivided according to the presence of hypertension (ANOVA followed by Bonferroni correction).ConclusionIn a population with a low cardiovascular risk, we found no differences in cardiovascular risk factors and echocardiographic parameters between patients with NCPHPT and PHPT and the controls.     

多层螺旋CT在诊断小儿急性阑尾炎中的应用

目的:探讨多层螺旋CT对小儿急性阑尾炎的诊断价值。方法:回顾分析经临床手术病理证实的53例小儿急性阑尾炎的CT表现特点。所有患儿均行多排CT横断面扫描及MPVR重建。结果:53例中,单纯性阑尾炎2例;急性化脓性阑尾炎伴周围炎4例,其中1例合并紫癜;急性化脓性阑尾炎伴穿孔33例,其中1例合并回肠末端美克尔憩室;坏疽性阑尾炎伴穿孔6例;阑尾脓肿8例。CT平扫以及MPVR重建显示阑尾肿大、增粗(直径大于6mm)30例,阑尾内粪石27例,阑尾周围蜂窝织炎23例,阑尾周围脓肿8例,大量腹水6例。结论:多层螺旋CT扫描及重建技术能为小儿阑尾炎的诊断提供有力依据,提高临床术前诊断能力。     

Vaccination with Staphylococcus aureus fibrinogen binding proteins (FgBPs) reduces colonisation of S. aureus in a mouse mastitis model

Abstract A mouse mastitis model was used to study the effect of vaccination with fibrinogen binding proteins and collagen binding protein from Staphylococcus aureus against challenge infection with S. aureus . The mice vaccinated with fibrinogen binding proteins showed reduced rates of mastitis compared with controls. Gross examination of challenged mammary glands of mice showed that the glands of mice immunized with fibronogen binding proteins developed mild intramammary infection or had no pathological changes compared with glands from control mice. Histopathological examination of tissue sections from challenged glands showed that most glands from mice vaccinated with fibrinogen binding protein developed disseminated necrosis or had no pathological changes. A significantly reduced number of bacteria could be recovered in the glands from mice immunized with fibrinogen binding proteins as compared with controls. In a similar study, immunization of mice with collagen binding protein did not induce protection against challenge infection with S. aureus .     

Nutritive value of forage biomass from sainfoin mixtures

Forage quality characteristics of field-grown mixtures of sainfoin with cocksfoot (50:50%), sainfoin with tall fescue (50:50%), and the same with the addition of subterranean clover in their composition (33:33:33%) were measured. Forage biomass from the mixtures of sainfoin with cocksfoot had generally higher forage quality than mixtures with tall fescue. It had higher crude protein content (11.52% of dry matter (with 1.07% units), significantly higher digestibility (61.74%) (with 6.51% units), higher neutral detergent fiber content (53.42%) (with 3.22% units), higher nutritive value (Unité Fourragère Viande – Unité Fourragère Lait, 0.690–0.583) and higher protein feeding value (Total Digestible Protein – Protein digestible dans l’intestine in dependence of nitrogen – Protein digestible dans l’intestine in dependence of energy), 72–70–79 g/kg of dry matter. Forage biomass showed more balanced basic chemical composition after the addition of subterranean clover, i.e.: higher crude protein content (with 0.30% units) and lower crude fiber content (with 0.14% units) for mixtures with cocksfoot; higher digestibility (with 0.29% units) for mixtures with cocksfoot; lower neutral detergent fiber content (with 0.45% units) for mixtures with cocksfoot and with 3.15% units for mixtures with tall fescue, higher energy feeding value (Unité Fourragère Viande – Unité Fourragère Lait) (with 0.007–0.012 for mixtures with cocksfoot and with 0.009–0.014 for mixtures with tall fescue), higher protein feeding value for both mixtures with cocksfoot and tall fescue. Forage biomass from mixtures of sainfoin with cocksfoot and Trifolium subterraneum ssp. brachycalicinum had the highest crude protein (11.89% of dry matter), the lowest crude fiber content (27.07% of dry matter) and the highest digestibility (62.81% of dry matter).     

早期伤口切开对血循毒蛇咬伤患者预后的影响

目的探讨血循毒类毒蛇咬伤患者早期伤口切开对预后的影响。方法回顾性分析我院2011年3月~2014年3月诊治的血循毒类毒蛇咬伤患者223例的临床资料,总结并比较其临床特点及预后。结果本组患者轻度肿胀97例中,伤后12h内切开21例,未溃疡12例,Ⅰ°溃疡7例,Ⅱ°溃疡2例;晚期切开或未切开76例,未溃疡15例,Ⅰ°溃疡41例,Ⅱ°溃疡16例,Ⅲ°溃疡4例。中度肿胀患者85例中,伤后12h内切开32例,未溃疡8例,Ⅰ°溃疡21例,Ⅱ°溃疡2例,Ⅲ°溃疡1例;晚期切开或未切开53例,未溃疡6例,Ⅰ°溃疡16例,Ⅱ°溃疡24例,Ⅲ°溃疡7例。重度肿胀患者41例中,伤后12h内切开17例,Ⅰ°溃疡11例,Ⅱ°溃疡4例,Ⅲ°溃疡2例;晚期切开或未切开24例,Ⅰ°溃疡2例,Ⅱ°溃疡6例,Ⅲ°溃疡16例。在蛇伤后12h内切开的患者坏死溃疡的形成、肿胀程度的改善均明显优于晚期切开或未切开的患者,差异有显著统计学意义(P0.05)。结论随着患者凝血功能的改善,早期伤口切开对血循毒类毒蛇伤患者局部伤口状况有较好的改善作用。     

Immunohistochemical Double Staining with Immunogold-Silver and Alkaline Phosphatase to Identify Nuclear Markers of Cellular Proliferation

To facilitate cell kinetics studies of brain tumors labeled with thymidine analogs, we developed a new method to identify nuclei labeled sequentially with bromodeoxyuridine (BUdR) and iododeoxyuridine (IUdR) by double staining with immunogold-silver and alkaline phosphatase. Patients received an intraoperative infusion of BUdR: excised tumor specimens were immediately labeled with IUdR in vitro. fixed with 70% alcohol, embedded in paraffin, and cut into 6 pm sections. The sections were incubated first with BR-3. a monoclonal antibody that recognizes only BUdR, and then with IU-4. a monoclonal antibody that recognizes both BUdR and IUdR: sections were counterstained with hematoxylin to identify unlabeled nuclei. Nuclei labeled only with IUdR stained red, whereas those labeled with BUdR or with both BUdR and IUdR stained black against a red background: unlabeled nuclei stained blue. This method was the most efficient differential staining technique to identify nuclei labeled only with IUdR and those labeled with BUdR among unlabeled nuclei.     

Epitope mapping human heat shock protein 90 with sera from infected patients

Abstract Epitope mapping with sera from a range of infected patients showed that antibodies are commonly produced which cross-react with a number of epitopes on human heat shock protein 90 (HSP 90). Such autoreactive antibodies were particularly frequent in patients suffering from systemic candidiasis (9 patients), invasive aspergillosis (6 patients), ABPA (2 patients), a patient with aspergilloma and one with malaria. The patient with malaria recognised similar epitopes to those with invasive aspergillosis and candidiasis including the highly conserved epitope LKVIRKVIRK and an epitope NNLGTI which was otherwise only recognised by patients with candidiasis. Crossreacting antibodies to relatively few epitopes occurred in patients with Enterococcus faecalis and Corynebacterium jeikeium endocarditis. This was contrasted with the results from 6 patients with systemic lupus erythematosus (SLE) who were positive on immunoblot against fungal HSP 90. These did not react with the above epitopes but reacted with other areas within human HSP 90.     

Somatostatin release in the hippocampus in the kindling model of epilepsy: a microdialysis study

Somatostatin biosynthesis in the hippocampus is activated during and following kindling epileptogenesis. The aim of this study was to investigate whether this phenomenon is associated with enhanced somatostatin release in vivo. Experiments have been run in awake, freely moving rats, implanted with a bipolar electrode in the right amygdala (for kindling stimulation), and with a recording electrode and a microdialysis probe in the left hippocampus. Basal somatostatin-like immunoreactivity (-LI) release was significantly greater in kindled than naive rats. In naive rats, a 2-min perfusion with 100 mM K(+) did not affect behavior and EEG recordings and nonsignificantly increased somatostatin-LI release; a 10-min K(+) perfusion evoked numerous wet dog shakes, electrical seizures (class 0; latency congruent with 8 min, duration congruent with 8 min), and somatostatin-LI release ( congruent with 350% of basal); and a single kindling after-discharge (4 +/- 3-s duration in the hippocampus) also evoked somatostatin-LI release ( congruent with 200% of basal). In kindled rats, a 2-min 100 mM K(+) perfusion evoked hippocampal discharges in three of seven animals (latency congruent with 2 min, mean duration congruent with 1.5 min) and increased somatostatin-LI release ( congruent with 250% of basal); a 10-min K(+) perfusion evoked behavioral seizures (class 1 to 5, latency congruent with 4 min, mean duration congruent with 12 min) with numerous wet dog shakes and robust somatostatin-LI release ( congruent with 350% of basal); and a kindling stimulation evoked generalized seizures (class 4 or 5, 77 +/- 15-s duration in the hippocampus) with remarkable somatostatin-LI release ( congruent with 300% of basal). These data demonstrate that hippocampal somatostatin release is increased in the kindling model in vivo.     

Testes size, ejaculate quality and sperm competition in birds

The relationship between testes size, ejaculate quality (volume, sperm concentration, number of sperm per ejaculate) and sperm competition in birds was analysed using data collected in artificial insemination studies. I hypothesized that ejaculate quality, because of natural selection, should be superior in species with intense sperm competition compared with other species. In regression analyses, testes weight increased with body weight, with an exponent less than one, and ejaculate volume increased with testes weight with an exponent not significantly different from one, whereas sperm number per ejaculate increased with testes weight with an exponent larger than one. Species with relatively large testes also produced ejaculates with a high sperm concentration. Monogamous species with a relatively low intensity of sperm competition copulate rarely, but deliver ejaculates with a relatively large number of sperm. Monogamous species with a high intensity of sperm competition copulate frequently, but produce ejaculates with a relatively small number of sperm. Males of polygynous species, which also experience intense sperm competition, copulate rarely with specific females, but produce many ejaculates per male each with a relatively small number of sperm.     

Allergy against chironomids (non biting midges) in adult atopic patients

Summary The aim of this investigation was to evaluate the prevalence of atopic sensitization to chironomids (CHI) in patients with asthma and/or rhinitis (A/R), and to study concomitant sensitization to CHI and other allergens. Skin prick tests were performed with 3 different CHI extracts as well as with common inhalant allergens in 600 consecutive patients, 495 of which had A/R. Allergen specific IgE antibodies in the sera against CHI, shell fish and cockroaches were analyzed with Magic Lite.59 (12%) of the patients with A/R had a positive skin test with CHI. Positive skin tests with house dust mites and a storage mite were more common in CHI allergic patients than in other atopic patients. Nasal or conjunctival provocation tests, performed on 23 of the patients with positive skin test with CHI, were clearly positive in 7 cases (30%), questionable in 8 (35%) and negative in 8 cases (35%).Magic Lite, performed on sera from 50 of the patients with positive skin test against CHI, was positive with CHI in 39 cases (78%), with crayfish in 33 (66%), shrimp 20 (40%), cockroach 21 (40%) and with crab in 3 cases (6%).It is concluded that sensitization against CHI is common in patients with A/R. The clinical relevance of the positive test results is, however, unknown. Concomitant sensitization with CHI, crustaceans and cockroach is common.