Molecular Terahertz Polarizability of PCH5, PCH7, and 5OCB

In this letter we determine the principal and main polarizabilities of the nematic liquid crystals PCH5, PCH7 and 5OCB. The polarizabilities are calculated from the terahertz refractive indices using Vuks’ approximation. 5OCB, which has two phenyl rings in its core, shows the highest terahertz anisotropy.     

Development of GM-CSF antagonist peptides

Granulocyte/macrophage colony stimulating factor (GM-CSF) is both a hematopoietic growth factor and a cytokine implicated in inflammatory disease. The development of GM-CSF antagonist peptides corresponding to the GM-CSF native sequence should allow their modification into higher affinity analogs, but this is hampered by the low affinity of linear peptides. To adequately evaluate such low affinity peptides, the use of several independent assays should allow specific versus nonspecific inhibitors to be distinguished. In this study, inhibition of GM-CSF-dependent cell growth, inhibition of GM-CSF binding and immunologic cross-reactivity between GM-CSF-derived peptides and native protein by neutralizing antibodies have been used to evaluate peptide analogs with potential bioactivity. The GM-CSF sequence was divided into 6 peptides ranging in size from 15-24 amino acids. Antisera were raised to these peptides in mice and assayed for immunologic cross-reactivity. 4/6 anti-peptide antisera bound GM-CSF on ELISA and 3/6 on immunoprecipitation. Antisera to two of the peptides (corresponding to residues 17-31 and 96-112) inhibited GM-CSF-dependent cellular proliferation in two cell lines, with one peptide derived from residues 17-31 demonstrating inhibition of GM-CSF binding and direct biological inhibitory activity. A peptide that did not elicit native GM-CSF reactive antibodies, corresponding to residues 54-78, was recognized by two neutralizing monoclonal antibodies. It exhibited inhibition of GM-CSF binding and direct biological antagonist activity. These studies implicate two sites in mediating GM-CSF biological activity, and indicate that biological antagonists can be developed based on these sites.     

Mesenteric vascular problems. A 26-year experience

Mesenteric vascular problems are infrequent, but may be catastrophic. During a 26-year period, 55 private patients were treated for the following disorders: (1) 12 patients with visceral artery aneurysms, (2) 8 with celiac compression syndrome, (3) 13 with chronic mesenteric ischemia, (4) 12 with acute mesenteric ischemia, and (5) 10 with mesenteric ischemia associated with aortic reconstructions. Splenic artery aneurysms were managed by excision and splenectomy, while celiac and hepatic had excision with graft replacement. Patients with celiac compression syndrome underwent lysis of the celiac artery. Two patients had compression of both celiac and superior mesenteric artery (SMA). One patient required vascular reconstruction of both arteries for residual stenoses. Patients having chronic mesenteric ischemia were treated with bypass grafts, with one death (7.7% mortality) and good long-term results. Those with acute mesenteric ischemia were treated by SMA embolectomy, bowel resection, or both, with a mortality of 67%. When associated with aortic reconstructions, mesenteric ischemia carried a mortality of 100% if bowel infarction occurred after operation, but when prophylactic mesenteric revascularization was performed at the time of aortic surgery, prognosis was greatly improved, with only one death among six patients. An aggressive approach including prompt arteriography with early diagnosis and surgical therapy is advocated for these catastrophic acute mesenteric problems.     

基于知识的CAx集成的系统框架研究

在分析国内外CAx集成技术、PDM产品、PKM研究现状的基础上，提出了基于知识的CAD／CAE／CAPP／CAQ集成技术，基于知识的CAx集成理论；产品数据管理、产品知识管理与协同产品商务的融合技术，构建了协同产品知识管理框架，以此为平台，有效地实现了基于知识的CAD／CAE／CAPP／CAQ的集成。     

Low-voltage p- and n-type organic self-assembled monolayer field effect transistors

We report on p- and n-type organic self-assembled monolayer field effect transistors. On the base of quaterthiophene and fullerene units, multifunctional molecules were synthesized, which have the ability to self-assemble and provide multifunctional monolayers. The self-assembly approach, based on phosphonic acids, is very robust and allows the fabrication of functional devices even on larger areas. The p- and n-type transistor devices with only one molecular active layer were demonstrated for transistor channel lengths up to 10 μm. The monolayer composition is proven by electrical experiments and by high-resolution transmission electron microscopy, electron energy loss spectroscopy, XPS, and AFM experiments. Because of the molecular design and the contribution of isolating alkyl chains to the hybrid dielectric, our devices operate at low supply voltages (-4 V to +4 V), which is a key requirement for practical use and simplifies the integration in standard applications. The monolayer devices operate in ambient air and show hole and electron mobilities of 10(-5) cm(2)/(V s) and 10(-4) cm(2)/(V s) respectively. In particular the n-type operation of self-assembled monolayer transistors has not been reported before. Hereby, structure-property relations of the SAMs have been studied. Furthermore an approach to protect the sensitive C(60) from immediate degradation within the molecular design is provided.     

AT1 angiotensin II receptor inhibition in pacing-induced heart failure: effects on left ventricular performance and regional blood flow patterns

5'-O-Myristoyl analogue derivatives of 3'-azido-2',3'-dideoxythymidine (AZT), designed as potential double-barrelled prodrugs to AZT and the myristic acid analogues, were synthesized. Their ability to protect CEM cells against human immunodeficiency virus (HIV)-induced cytopathogenicity was determined and structure-activity paradigms were developed. 3'-Azido-2',3'-dideoxy-5'-O-(4-oxatetradecanoyl)thymidine (EC50 = 1.4 nM) and 3'-azido-2',3'-deoxy-5'-O-(12-bromododecanoyl)thymidine (EC50 = 3.2 nM) were the most effective anti-HIV-1 agents, relative to AZT (EC50 = 10 nM). These myristoyl analogue derivatives were more lipophilic (calculated log P = 4.5-8.1 range) than the parent compound AZT (log P = 0.06), and a linear correlation between their log P and HPLC log retention times was observed. The ester cleavage half-lives (t1/2) for esters upon in vitro incubation with porcine liver esterase, rat plasma or rat brain homogenate was dependent on the steric bulk, and electronegative inductive effect of the alpha-substituent (H, Br, F), of the 5'-O-myristoyl analogue moiety. 3'-Azido-2',3'-dideoxy-5'-O-(11-(4-iodophenoxy) undecanoyl)-thymidine exhibited t1/2 values of 80.4, 3.7 and 150.0 min upon incubation with porcine liver esterase, rat plasma and rat brain homogenate, respectively.     

Assessing same/different judgments in individuals with severe intellectual disabilities: a status report

This report summarizes state-of-the-art approaches for assessing visual stimulus same/different judgments in individuals with severe intellectual disabilities. Methods are described that permit one to conduct assessments on a population-wide basis, excluding few if any participants due to failure to acquire necessary baseline performances. Methodological investigations summarized here indicate that one can obtain reliable same/different judgments with a variety of stimuli in virtually anyone for whom a basal score on the Peabody Picture Vocabulary Test can be obtained. This approach includes judgments involving not only familiar, readily nameable stimuli, but also abstract two-dimensional forms of the type commonly used to minimize extraexperimental influences on performance. Taken together, recent findings lead to the conclusion that past studies have significantly under-estimated the capacity of participants with low MA scores to make same/different judgments. They also suggest a more general methodological approach that can potentially lead to more sensitive assessment of other behavioral capacities in this difficult-to-test population.