Histopathology of the digestive gland of an Antarctic limpet exposed to cadmium

Histopathological alterations induced experimentally with cadmium (Cd) in Antarctic limpets (Nacella concinna), exposed for different times and concentrations were compared to controls. At the light microscope level, samples exposed to the contaminant for short periods (6, 12 and 24 h) at two different concentrations (0.25 and 0.5 mg l(-1)) showed no alterations compared to controls. After 48 h of exposure at a 0.5 mg l(-1) Cd concentration, vacuolisation of the basophilic cells was observed. After 72 h exposure, there was a marked loss of all the digestive gland structure, with cell autolysis and loss of basophilia.     

动态电源管理技术优化嵌入式应用性能与功耗比

消费者对采用多媒体嵌入式处理器产品的需求迅速增长,这既要求提高性能又要求降低功耗.但是高性能处理必须增加计算复杂度并加快时钟速率,如果采用权宜之计的节省功耗设计方案,是很难实现的.我们需要的是一种具有战略意义的方法来管理功耗,以便在具体的嵌入式应用中优化性能与功耗的关系.利用Blackfin数字信号处理器(DSP)系列产品固有的动态电源管理能力,可以实现这样的方法.     

Stress-Related Dysfunction of Adult Hippocampal Neurogenesis—An Attempt for Understanding Resilience?

Newborn neurons in the adult hippocampus are regulated by many intrinsic and extrinsic cues. It is well accepted that elevated glucocorticoid levels lead to downregulation of adult neurogenesis, which this review discusses as one reason why psychiatric diseases, such as major depression, develop after long-term stress exposure. In reverse, adult neurogenesis has been suggested to protect against stress-induced major depression, and hence, could serve as a resilience mechanism. In this review, we will summarize current knowledge about the functional relation of adult neurogenesis and stress in health and disease. A special focus will lie on the mechanisms underlying the cascades of events from prolonged high glucocorticoid concentrations to reduced numbers of newborn neurons. In addition to neurotransmitter and neurotrophic factor dysregulation, these mechanisms include immunomodulatory pathways, as well as microbiota changes influencing the gut-brain axis. Finally, we discuss recent findings delineating the role of adult neurogenesis in stress resilience.     

Organized porous alumina membranes for high density silicon nanowires growth

In this paper, we present results on the fabrication of porous alumina membranes on silicon substrates with a long-range order induced by nanoimprint lithography. Fabricated porous alumina matrices present a perfect triangular array of vertical cylindrical pores on areas of 500 × 500 μm² corresponding to the imprinted surfaces. Also, we demonstrate that it is possible to have a directed density multiplication during the pore formation, compared to the nanoimprint mold, by the initial indentation of only one third of the expected alumina pores. The gold catalyst, needed for nanowires growth, is deposited at the bottom of each pore by electrochemistry. The proposed process is scalable to wafer-scale areas, compatible with microelectronics fabrication standards and is not limited to non-fragile substrates like direct bulk aluminum nanoindentation.     

Dynamic Characteristics of a Curved Cable-stayed Bridge:Operational Modal Testing and FE Modeling

This paper summarizes the analytical and experimental dynamic analyses carried out to assess the actual dynamic behaviour of a curved cable-stayed bridge,recently erected in the commercial harbour of Porto Marghera ( Venice,Italy). Ambient vibration tests were carried out to determine the dynamic characteristics of the bridge and more than 20 modes were identified in the frequency range 0～10Hz. In the theoretical study,a 3D FE model of the bridge was developed using an integrated CAD-FEA approach; subsequen...     

Realization of a scale of absolute spectral response using the National Institute of Standards and Technology high-accuracy cryogenic radiometer

Using the National Institute of Standards and Technology high-accuracy cryogenic radiometer (HACR), we have realized a scale of absolute spectral response between 406 and 920 nm. The HACR, an electrical-substitution radiometer operating at cryogenic temperatures, achieves a combined relative standard uncertainty of 0.021%. Silicon photodiode light-trapping detectors were calibrated against the HACR with a typical relative standard uncertainty of 0.03% at nine laser wavelengths between 406 and 920 nm. Modeling of the quantum efficiency of these detectors yields their responsivity throughout this range with comparable accuracy.     

Identification of 8-Hydroxyquinoline Derivatives That Decrease Cystathionine Beta Synthase (CBS) Activity

CBS encodes a pyridoxal 5′-phosphate-dependent enzyme that catalyses the condensation of homocysteine and serine to form cystathionine. Due to its implication in some cancers and in the cognitive pathophysiology of Down syndrome, the identification of pharmacological inhibitors of this enzyme is urgently required. However, thus far, attempts to identify such molecules have only led to the identification of compounds with low potency and limited selectivity. We consequently developed an original, yeast-based screening method that identified three FDA-approved drugs of the 8-hydroxyquinoline family: clioquinol, chloroxine and nitroxoline. These molecules reduce CBS enzymatic activity in different cellular models, proving that the molecular mechanisms involved in yeast phenotypic rescue are conserved in mammalian cells. A combination of genetic and chemical biology approaches also revealed the importance of copper and zinc intracellular levels in the regulation of CBS enzymatic activity—copper promoting CBS activity and zinc inhibiting its activity. Taken together, these results indicate that our effective screening approach identified three new potent CBS inhibitors and provides new findings for the regulation of CBS activity, which is crucial to develop new therapies for CBS-related human disorders.     

以模块为基础的薄带材和箔材平直度控制

薄带材和箔材的平直度或板形控制必然要求一定程度的模型化。这是由于轧钢工艺本身的复杂性所要求的。描述在轧制带卷前到形成良好初始平直度的最佳轧制程序表及在高平直度控制情况下生产带卷的过程中使用的模块。集中讨论在普通4辊铝薄带和箔材轧机上所用的平直度模块。     

Hyaluronan-coated poly(propylene imine) dendrimers as biomimetic nanocarriers of doxorubicin

A coating technology based on low molecular weight hyaluronic acid (HA) and ferulic acid (FA) was applied to the coating of low generation poly(propylene imine) dendrimers through a biocompatible hexa(ethylene glycol) spacer. The ensuing HA-FA-HEG-PPID dendrimeric materials showed interesting loading capability (between 7.65% and 9.08%) regarding anticancer agent doxorubicin, and their interactions with the drug appeared to hamper the drug release in the physiological environment. Thus, the stable nanostructured loaded delivery systems were able to internalize into cells expressing the HA receptor CD44 and to demonstrate high cytotoxicity comparable to that shown by equivalent amounts of free doxorubicin. Thus, HA-FA-HEG-PPID dendrimeric materials were proposed as biocompatible drug carriers capable of transporting anticancer doxorubicin to tumor cells.