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The two standard models used for communication in concurrent programs, shared memory and message passing, have been the focus of much debate for a long time. Still, we believe the main issue at stake should not be the choice between these models, but rather how to ensure that communication is structured, i.e., it occurs only in syntactically restricted code regions. In this survey, we explore concurrency control models and evaluate how their characteristics contribute positively or negatively to the support for structured communication. We focus the evaluation on three properties: reasonability, which is the main property we are interested in and determines how easily programmers can reason about a concurrent program’s execution; performance, which determines whether there are any distinct features which can prevent or facilitate efficient implementations; and composability, which determines whether a model offers constructs that can be used as building blocks for coarser-grained, or higher-level, concurrency abstractions.  相似文献   
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Maturity-onset diabetes of the young (MODY) type 2 is caused by heterozygous inactivating mutations in the gene encoding glucokinase (GCK), a pivotal enzyme for glucose homeostasis. In the pancreas GCK regulates insulin secretion, while in the liver it promotes glucose utilization and storage. We showed that silencing the Drosophila GCK orthologs Hex-A and Hex-C results in a MODY-2-like hyperglycemia. Targeted knock-down revealed that Hex-A is expressed in insulin producing cells (IPCs) whereas Hex-C is specifically expressed in the fat body. We showed that Hex-A is essential for insulin secretion and it is required for Hex-C expression. Reduced levels of either Hex-A or Hex-C resulted in chromosome aberrations (CABs), together with an increased production of advanced glycation end-products (AGEs) and reactive oxygen species (ROS). This result suggests that CABs, in GCK depleted cells, are likely due to hyperglycemia, which produces oxidative stress through AGE metabolism. In agreement with this hypothesis, treating GCK-depleted larvae with the antioxidant vitamin B6 rescued CABs, whereas the treatment with a B6 inhibitor enhanced genomic instability. Although MODY-2 rarely produces complications, our data revealed the possibility that MODY-2 impacts genome integrity.  相似文献   
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In this article we demonstrate the use of self-assembled peptide nanotube structures as masking material in a rapid, mild and low cost fabrication of polymerized p-toluenesulfonate doped poly(3,4-ethylenedioxythiophene) (PEDOT:TsO) nanowire device. In this new fabrication approach the PEDOT:TsO nanowire avoids all contact with any organic solvents otherwise traditionally used in clean room fabrication. This can be achieved due to the intriguing properties of the self-assembled peptide nanotubes utilized as a dry etching mask for the patterning of the PEDOT:TsO nanowire. The peptide nanotubes, despite remaining stable during the reactive ion etching procedure, can be dissolved rapidly in water afterwards. The fabricated PEDOT:TsO nanowire devices exhibit excellent electrical characteristics. Finally, the potential of PEDOT:TsO nanowires as temperature sensors has been demonstrated and the high resolution of the sensor was illustrated.  相似文献   
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Important strides are being made in understanding the effects of structural features of bryostatin 1, a candidate therapeutic agent for cancer and dementia, in conferring its potency toward protein kinase C and the unique spectrum of biological responses that it induces. A critical pharmacophoric element in bryostatin 1 is the secondary hydroxy group at the C26 position, with a corresponding primary hydroxy group playing an analogous role in binding of phorbol esters to protein kinase C. Herein, we describe the synthesis of a bryostatin homologue in which the C26 hydroxy group is primary, as it is in the phorbol esters, and show that its biological activity is almost indistinguishable from that of the corresponding compound with a secondary hydroxy group.  相似文献   
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Ran N  Agami M  Oron G 《Water research》2004,38(9):2240-2247
Constructed wetlands are well known as highly efficient system to treat wastewater from different sources. This treatment system is cost-effective for reuse in desert areas. A continuous flow, free water surface (FWS) pilot wetland using the duckweed plant Lemna gibba L. was constructed at the Blaustein Institute for Desert Research in Kiryat Sde Boker of the Negev, Israel, and operated on domestic primary effluents. Water quality and system efficiency were observed during the experiment for reuse purposes. Results indicated that, hydraulic residence time averaged 4.26+/-0.61d, average influent flow rate was 0.234+/-0.027m(3)/d and hydraulic load 0.22+/-0.03m/d. Hydraulic efficiency in the system was high and allowed good settling conditions. Suspended solids and organic matter removals were the highest and effluent concentrations were 13.1+/-9.7 and 40.3+/-11.9mg/l for TSS and total BOD(5), respectively. Nitrogen removal was lower (10-20%) but slightly increased with higher nitrogen loads. Therefore, nitrogen content in the plants was high (4.3+/-0.5%/kg dry plant). Phosphorus removal was negligible. High removal for fecal coliform (approximately 95%) and effluent turbidity (> 50%) were also observed.  相似文献   
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