An adsorption behavior of low-density lipoprotein onto cholesterol-modified dextran studied by a quartz crystal microbalance

The use of quartz crystal microbalance (QCM) for on-line monitoring of the adsorption of low-density lipoprotein (LDL) onto cholesterol-modified dextran (CMD) was described. Kinetics studies were made and molecule interaction mechanism was discussed. Experimental results showed that kinetic curves fitted Langmuir adsorption equation quite well. When LDL concentrations (ng/μl) were 9.9, 12.38 and 14.14, respectively, the apparent rate constants (s^− 1) and adsorption capacities (ng/cm²) were estimated to be 0.0477, 0.0536, 0.0628 and 124.5, 161.6, 194.3, respectively. The maximal LDL adsorption capacity attained 329.6 ng/cm² and the adsorptive efficiency was calculated to be 72.91%. Moreover, a new method to evaluate the adsorption behavior was provided.     

Effects of dietary proteins on iron bioavailability—A review

In this review we have summarized the iron bioavailability literature dealing with protein (or major dietary protein source) effects and proposed a mechanism for these effects compatible with existing empirical data. Data from studies employing a variety of approaches are fairly consistent in showing that meats enhance non-heme iron absorption while plant, milk and egg proteins depress it. The variable, and sometimes opposite, effects of different proteins on iron bioavailability may be explained by the following proposed mechanism: (1) protein enhances iron bioavailability by releasing peptides during digestion which form soluble, low molecular weight complexes that readily release iron to mucosal receptors; (2) protein depresses iron bioavailability by releasing peptides which form insoluble complexes with iron or which form soluble complexes that do not release iron to mucosal receptors. Data from the literature, including our own evidence, which support the above hypothesis are discussed.     

Aggregation-induced emission luminogen-assisted stimulated emission depletion nanoscopy for super-resolution mitochondrial visualization in live cells

Nano Research - Aggregation-induced emission luminogens (AIEgens) are fluorescent agents that are ideal for bioimaging and have been widely used for organelle targeting, cellular mapping, and...     

极大节旋藻(Arthrospira maxima)生物钟基因kaiC的克隆及分析

以kaiC基因簇部分已知序列为引物设计位点,采用PCR反应池法从节旋藻基因组fosmid文库中筛选到kaiC基因克隆,通过步移测序获得了kaiC基因全长序列。kaiC基因编码区长1554bo,基因GC碱基含量平均为41．76％,密码子第三位明显偏向于U。在基因上游385bp范围内发现一个可能的启动子序列和一些基因调控元件。KaiC蛋白分析发现了Walker A、DXXG、不完整的Walker B等重要模体和具有催化作用的功能位点。Southem杂交的结果证明kaiC基因在极大节旋藻中为单拷贝。极大节旋藻kaiC基因的特殊结构特征为研究kai基因簇的进化提供了重要的启示。     

负载氯喹的骨靶向纳米颗粒打破肿瘤细胞增殖与骨吸收之间的恶性循环

肿瘤细胞增殖与骨吸收之间的恶性循环加剧了骨肿瘤的进展和转移风险.为此,我们设计并制备了聚乙二醇-阿仑膦酸钠修饰的聚多巴胺(PPA)纳米粒子,并在其表面负载自噬抑制剂氯喹(CQ),期望利用该治疗载体(PPA/CQ)打破肿瘤细胞增殖与骨吸收之间的恶性循环,从而有效地治疗骨肿瘤.实验证明,PPA/CQ可以有效地富集到骨组织,...     

Comparisons of Costs After Tax of Storing Silages in Four Types of Structures

Annual ownership costs (30 yr) and costs per ton of dry matter after storage losses were computed for five sizes of concrete bunker silos and three sizes each of concrete stave upright, oxygen-limiting steel upright, and oxygen-limiting concrete upright silos. Costs were for all combinations of 0, 3, 6, 9, and 12% discount rates with taxable incomes representing 0, 14, 28, and 42% marginal tax rates. Storage losses were 6, 10, and 14% for oxygen-limiting, concrete upright, and bunker structures. Annual costs (and cost per English ton) for sample silos ranged $1198 to $6479 ($3.72 to $33.62) for bunkers, $1125 to $5486 ($6.10 to $30.46) for concrete uprights, $2718 to $11,548 ($12.71 to $68.20) for oxygen-limiting concrete units, and $3807 to $20,579 ($20.13 to $96.85) for other oxygen-limiting steel units. At 28% tax rate and 6% discount rate for a 12 × 40 × 112-ft bunker, a 24 × 80 ft concrete upright and oxygen-limiting concrete upright, and a 25 × 80 ft oxygen-limiting steel upright, ratios of cost per ton of silage recovered for 259 to 301 tons were 1.0, 1.0, 2.2, and 3.7. Filling oxygen-limiting structures 1.5 times/yr reduced ratios to 1.0, 1.0, 1.5, and 2.5, but ratios were unaffected by altering tax or discount rate. Prediction equations deviated 5% from estimated annual cost.     

Applicability assessment of a real-time PCR assay for the specific detection of bovine,ovine and caprine material in feedstuffs

A TaqMan real-time polymerase chain reaction (PCR) method was developed for specific detection of bovine, ovine and caprine processed animal protein (PAP) in industrial feedstuffs. The method uses species-specific primers and probes targeting short mitochondrial D-loop sequences, and a positive amplification control based on 18S rRNA gene. The applicability of the real-time PCR protocol was assessed through analysis of 126 industrial feed samples that were manufactured to reproduce rendering processes of commercial feeds destined for farmed animals. The assay successfully classified samples as positive or negative according to the ruminant composition, enabling qualitative detection of banned material in feeds at levels as low as 0.1%. Although the method provides quantitative potential, results suggest that the real quantitative capability of the assay is limited by the existing variability in terms of composition and processing treatments of the feeds, which affect the amount and quality of amplifiable DNA.     

HIGHER AVERAGE MERCURY CONCENTRATION IN FISH FILLETS AFTER SKINNING AND FAT REMOVAL

Ten male and ten female brown trout (Salmo trutta L.) ranging in weight from about 500 to 3500 grams were caught in Lake Ontario. Opposite sides of each individual fish were randomly processed and trimmed to yield skinned or unskinned fillets. Skinning resulted in an increase in the average concentration of total mercury in the fillets of fish of either sex but the increases were not significant .
With the exception of the unskinned fillets of the male fish, the concentration of mercury in the fillets increased significantly as the weight of the fish of either sex increased. The fillets of the male fish appeared to be higher in mercury than that in the corresponding fillets of female fish of comparable weight. In all instances, the concentrations of mercury in skinned and unskinned fillets were well below the 1 ppm fresh weight action level of the U.S. Environmental Protection Agency.     

Electrical and reliability characterization of metal-gate/HfO2/Ge FET’s with Si passivation

Field-effect transistors with metal gate and HfO₂ gate dielectric on silicon-passivated germanium substrate are studied. Capacitance-Voltage characteristics show lower gate capacitance at negative gate voltages, irrespective of the device channel polarity. Possible mechanisms for this asymmetry are discussed. Reliability of the metal/high-k gate stack on sub-micron p-channel transistors is evaluated. Time-dependent dielectric breakdown analysis indicates comparable gate-stack quality on germanium and silicon substrates.