Dry, High Resolution Autoradiography

Microtomed sections of freeze-dried, paraffin-embedded tissues are placed on pieces of thin sheet-Teflon backed by a felt pad. The sections are then pressure-mounted on dry photographic emulsion. After suitable exposure, the sections are firmly cemented to the emulsion with 0.45% cellulose acetate in a 10:1 mixture of 2-butanone and acetone. This prevents the specimens from falling off or moving during photographic processing, though the tissue can be stained through the cellulose acetate binder. The method has been tested with tissues containing tritium-labelled DNA, and it produced resolution comparable to that obtained with standard liquid emulsion or stripping film techniques.     

Dry,High Resolution Autoradiography

Microtomed sections of freeze-dried, paraffin-embedded tissues are placed on pieces of thin sheet-Teflon backed by a felt pad. The sections are then pressure-mounted on dry photographic emulsion. After suitable exposure, the sections are firmly cemented to the emulsion with 0.45% cellulose acetate in a 10:1 mixture of 2-butanone and acetone. This prevents the specimens from falling off or moving during photographic processing, though the tissue can be stained through the cellulose acetate binder. The method has been tested with tissues containing tritium-labelled DNA, and it produced resolution comparable to that obtained with standard liquid emulsion or stripping film techniques.     

Piperine Attenuates Cardiovascular, Liver and Metabolic Changes in High Carbohydrate, High Fat-Fed Rats

Black pepper is used worldwide to enhance food flavor. We investigated dietary supplementation with piperine, the active principle of black pepper, to high carbohydrate, high fat (HCHF) diet-fed rats as a model of human metabolic syndrome. Rats were fed with either HCHF diet (carbohydrate, 52%; fat, 24%; 25% fructose in drinking water) or cornstarch (CS) diet for a total of 16 weeks. Diets of the treatment groups (CS + piperine and HCHF + piperine) were supplemented with piperine for the last 8 weeks of this protocol. After 16 weeks, rats fed with HCHF diet developed hypertension, elevated oxidative stress and inflammation-induced cardiac changes (infiltration of inflammatory cells in heart, increase in count and degranulation of mast cells in heart, cardiac fibrosis and increase in ventricular stiffness), reduced responsiveness of aortic rings, impaired glucose tolerance, abdominal obesity together with liver fibrosis, fat deposition and increased plasma liver enzymes. Supplementation with piperine (375 mg/kg food; approximately 30 mg/kg/day) in HCHF-fed rats normalized blood pressure, improved glucose tolerance and reactivity of aortic rings, reduced plasma parameters of oxidative stress and inflammation, attenuated cardiac and hepatic inflammatory cell infiltration and fibrosis and improved liver function. These changes clearly suggest that piperine reduces symptoms of human metabolic syndrome in HCHF-fed rats by reducing inflammation and oxidative stress.     

High Corticosterone,Not High Energy Cost,Correlates with Reproductive Success in the Burrow-Nesting Ancient Murrelet

Theory and observations suggest that offspring abandonment in animals may occur when the costs to future reproductive output of current reproductive effort outweigh the fitness benefits of rearing the current brood. While hormonal cues (i.e. corticosterone) or energy reserves are believed to be involved, few studies have directly focused on the proximate cues influencing behaviours directly related to reproductive success. To address this information gap, we determined the incubation metabolic rates and corticosterone (CORT) levels of naturally fasting and freely incubating ancient murrelets (Synthliboramphus antiquus). Respiratory quotient (RQ) increased with date, suggesting that incubating ancient murrelets shifted from strictly lipid-based metabolism towards more protein-based metabolism as incubation progressed. Birds that hatched only one nestling had higher levels of circulating CORT than those which hatched two, suggesting that birds which laid only a single egg found incubation more stressful than those which laid two. However, CORT levels and incubation shift lengths were not correlated, suggesting that birds that undertook prolonged incubation shifts did so only when their energy stores were not jeopardized.     

实施“三高”教学,创建“微生物学实验”课程新体系

深化微生物实验教学改革,实施“高起点、高效率、高质量”教学,从调整教学内容,改革教学方法,建立和完善考评机制入手,创建“以基础知识和基本技能为基础性内容,以创新能力培养为核心内容”的微生物学实验课程新体系,激发了学生对微生物学实验的兴趣,培养了学生独立思考、创新思维和综合动手的能力。     

The High River Microblade Industry,Alberta

Abstract

A small collection of obsidian and chalcedony microblades, from a site near Calgary, Alberta, is described and compared with other microblades from the Plains and from the Plateau. Although the age and cultural affiliations of the micro blades are not certain, there is some evidence to suggest that they are early in the Plains sequence. The microblades have some distinctive attributes including ridge flakes, for which a typology is suggested. A comparison of the High River microblades with a large sample from the Interior Plateau of British Columbia suggests that the stimulus for the Alberta micro blades did not derive from the Plateau.     

A Template-Free,Ultra-Adsorbing,High Surface Area Carbonate Nanostructure

We report the template-free, low-temperature synthesis of a stable, amorphous, and anhydrous magnesium carbonate nanostructure with pore sizes below 6 nm and a specific surface area of ∼ 800 m² g⁻¹, substantially surpassing the surface area of all previously described alkali earth metal carbonates. The moisture sorption of the novel nanostructure is featured by a unique set of properties including an adsorption capacity ∼50% larger than that of the hygroscopic zeolite-Y at low relative humidities and with the ability to retain more than 75% of the adsorbed water when the humidity is decreased from 95% to 5% at room temperature. These properties can be regenerated by heat treatment at temperatures below 100°C.The structure is foreseen to become useful in applications such as humidity control, as industrial adsorbents and filters, in drug delivery and catalysis.     

rhEPO-Fc融合蛋白的表达、纯化及质量研究

用无血清培养基培养分泌表达rhEPO-Fc融合蛋白的工程细胞株MY06（CHO细胞）,收集发酵培养上清,通过离心、过滤、亲和层析、离子交换层析、分子筛等方法对目的蛋白进行纯化,通过lowry法、SDS-PAGE、Western-blot、HPLC、ELISA及IEF等方法研究目的蛋白质量,以建立rhEPO-Fc融合蛋白的发酵、纯化工艺,并探寻该融合蛋白的质量检测方法。结果通过该工艺rhEPO-Fc蛋白表达量高达2g/L,蛋白纯化得率达45%以上,纯度可达98％以上,相对分子质量约为60KD,t1/2长达38h,免疫印迹证明具有天然EPO的免疫原性。研究结果表明该生产工艺可获得rhEPO-Fc的高效表达,纯化得率高,质量检验方法稳定可靠,适用于大规模生产。     

A Cloned Pig Model for Examining Atherosclerosis Induced by High Fat,High Cholesterol Diets

The pig is a recognized model for the onset of coronary heart disease and heart attacks. Previous studies have shown that serum cholesterol levels in the pig can be elevated using a high fat, high cholesterol (HFHC) diet. What has been lacking is a genetically defined model corresponding to human ApoE4 susceptibility that can be linked to diets capable of inducing atherosclerosis. This study used a cloned pig model to examine the impact of cholesterol levels with the development of aorta fatty deposits leading to atherosclerosis. Diets were formulated using vegetable sources of protein to provide similar intakes of metabolizable energy, calcium, phosphorous and principal amino acids in both control and HFHC groups. After 60 days, the HFHC group demonstrated a 40-fold increase in aortic fatty streak lesion area combined with 6- and 11-fold increases in total and LDL cholesterol, respectively, over control diet fed cloned pigs. Previous studies have suffered from either imbalanced total caloric intake, an overall imbalance in the nutrition of the control versus HFHC groups or genetic heterogeneity when evaluating dietary constraints related to atherosclerosis. This study demonstrated that cloned, genetically-defined ApoE4 pigs provided balanced nutrition diets provide an experimental system ideally suited to examining atherosclerosis and the onset of coronary heart disease.     

High frequency body mass measurement,feedback, and health behaviors

We analyze weight and fat percentage measurements of respondents in an online general population panel in the Netherlands, collected using wireless scales, with an average frequency of 1.6 measurements per week. First, we document the existence of a weekly cycle; body mass is lowest on Fridays and highest on Mondays, showing significant (p < 0.01) differences of, on average, 0.2 kilogram in weight, 0.06 in BMI value, and 0.03 in fat percentage. Second, we find that in the general population fat-based measures of obesity point at a three times larger prevalence of obesity (53%) than BMI-based measures (17%). Third, we find that feedback that includes a recommended weight range increases the temporal variation in individual body mass by almost ten percent (sd for weight increases from 1.13 to 1.22; sd for BMI increases from 0.37 to 0.41; sd for fat percentage increases from 0.55 to 0.61.     

Facies of Liassic sponge mounds, central High Atlas, Morocco

Summary Liassic sponge mounds of the central High Atlas (Rich area, northern Morocco) have a stratigraphic range from the Lower/Upper Sinemurian boundary interval up to the lower parts of the Lower Pliensbachian (Carixian). The base of Liassic sponge mounds consists of a transgressive discontinuity, i.e., a condensed section of microbioclastic wackestones with firm- and hardgrounds, ferruginous stromatolites, sponge spicules and ammonites. The top of Liassic sponge mounds is an irregular palaeorelief covered by cherty marl-limestone rhythmites, namely hemipelagic spicular wackestones with radiolaria. In the Rich area, section Foum Tillicht, the sponge mound succession has a total thickness of about 250 meters. Within this succession we distinguished between three mound intervals. The lower mound interval shows only small, meter-scale sponge mounds consisting of boundstones with lyssakine sponges, commensalicTerebella and the problematicumRadiomura. This interval forms a shallowing-upward sequence culminating in a bedded facies withTubiphytes, calcareous algae (Palaeodasycladus), sponge lithoclasts, coated grains, and thin rims of marine cement. The middle mound interval is aggradational with decametric mounds and distinct thrombolitic textures and reefal cavities. The mound assemblage here consists of hexactinellid sponges, lithistid demosponges, non-rigid demosponges,Radiomura, Serpula (Dorsoserpula), Terebella, encrusting bryozoa, and minor contributions by calcareous sponges, and excavating sponges (typeAka). Thrombolites are dendrolitic and may reach sizes of several tens of centimeters, similar to the maximum size of siliceous sponges. The upper mound interval appears retrogradational and geometries change upsection from mound shapes to flat lenses and level-bottom, biostromal sponge banks. The biotic assemblage is similar to that of the middle mound interval and there is no difference between mound and bank communities. The demise of sponge mounds is successive from regional spread in the Sinemurian to more localised spots in the Lower Pliensbachian. This reduction correlates with an increasing influence of pelagic conditions. At Foum Tillicht, sponge mounds lack any photic contribution and there is virtually no differentiation into subcommunities between mound surface and cavity dwelling organisms. There is some evidence that the heterotrophic food web of mound communities was sourced by oxygen minimum zone edge effects, namely microbial recycling of essential elements such as N and P. Basin geometry suggests a waterdepth of several 100's of meters, well below the photic zone and possibly only controlled by the depth range of the oxygen minimum zone. Palaeoceanographic conditions of well-stratified deeper water masses diminished gradually during widespread transgression across the Sinemurian to Pliensbachian boundary culminating in the Lower Pliensbachianibex ammonite zone.     

Brazzein:一种耐热的甜味蛋白

Brazzein是从非洲西部野生植物Pentadiplandra brazzeana Baillon的果实中提取的一种甜味蛋白。Brazzein由54个氨基酸残基组成,Mr为6500,等电点为5,并且具有很好的热稳定性。本文着重概述Brazzein的结构与功能的关系,及其在基因工程中的研究前景。