Intestinal acariasis in Anhui Province

INTRODUCTIONThe mites found in stored food and house comprise a largegroup of subclass Acari,belonging to the suborderAcardida of the order Acariformes.They can be found indust and vacuum samples from floors,furniture,mattresses,Chinese herbal medicine,dry fruit,grain,

LsrR-binding site recognition and regulatory characteristics in Escherichia coli AI-2 quorum sensing

(QS ) 在治安法官察觉到处理，细菌由利用响应许多环境暗示称为 autoinducers 的小发信号的分子调整基因表示。Autoinducer 2 (AI-2 ) ，表明分子的 QS 建议涉及 interspecies 通讯，被克否定、克积极的细菌的许多种类生产。在 Escherichia coli 和沙门氏菌 typhimurium，细胞外的 AI-2 被 lsr 操纵子编码的 transporter 进口进房间。lsr 操纵子在上游，有编码 LsrR 的分叉地抄录的基因，它以前被报导镇压 lsr 操纵子和自己的抄写。这里，我们第一次证明了 LsrR 镇压 lsr 操纵子和自己由的抄写对他们用胶化移动和 DNase 的倡导者直接有约束力我 footprinting 试金。牛乳糖记者试金进一步建议在 lsrR 和 lsrA 倡导者区域的二个主题为 LsrR 绑定是关键的。而且，与结论一致，那 phosphorylated AI-2 能在以前的研究减轻 LsrR 的压抑，我们 phospho-AI-2 显示的数据表演不能在 vitro 绑在它的自己的倡导者的 LsrR。

北大别超高压榴辉岩的快速折返与缓慢冷却过程

岩石学研究表明,北大别超高压榴辉岩经过了超高压和高压榴辉岩相变质作用以及麻粒岩相叠加和角闪岩相退变质作用。其中,高压麻粒岩相和角闪岩相变质阶段形成的后成合晶以及石榴子石和单斜辉石等矿物中成分分带的存在,证明该区榴辉岩经历了一个快速折返过程;而不同变质阶段的温度、压力和形成时代,却反映该区榴辉岩在峰期超高压变质作用之后又经历了一个缓慢冷却过程。超高压岩石折返期间的缓慢冷却过程也许正是北大别长期难以发现柯石英和有关超高压证据的重要原因。因此,本文为大别山不同超高压岩片的差异折返模型的建立提供了新的证据。

Synthesis and characterization of yellow water-borne polyurethane using a diol colorant as extender

A novel and facile method toward a series of yellow water-borne polyurethane was developed by using an intrinsically colored diol in this paper.The yellow aqueous dispersion PCLD-HENA-PU was synthesized based on isophorone diisocyanate(IPDI), polycaprolactonediol(PCLD) and 2,2-dimethylol propionic acid(DMPA) using a yellow diol N,N-bis(2-hydroxyethyl)-4-nitroaniline (HENA) as a chain extender.Due to the complete reaction of OH group in colorant HENA with NCO group in diisocyanate,a series of stable yello...

Increased susceptibility to experimental steatohepatitis induced by methionine-choline deficiency in HBs-Tg mice

BACKGROUND:Worldwide,about 25% of individuals with chronic hepatitis B have fatty liver disease.Lipogenic diets that are completely devoid of methionine and choline induce nonalcoholic fatty liver disease.However,no animal model of nonalcoholic steatohepatitis associated with HBV infection is available,and the influence of viral infection on nutritional hepatic steatosis is unclear.METHODS:We used HBV surface antigen transgenic mice(HBs-Tg mice),which mimic healthy human carriers with hepatitis B surface antigen.The mice were fed with a high-fat methionine-choline-deficient diet(MCD) to build a reliable rodent nutritional model of nonalcoholic steatohepatitis associated with HBV infection,and the changes in body weight and serum triglycerides were measured.Hepatocyte ballooning changes were determined by hematoxylin and eosin staining.The extent of hepatic fat accumulation was evaluated by oil red O staining.Immunohistochemical assays were performed to detect proliferating cell nuclear antigen as an index of cell proliferation.RESULTS:MCD feeding provoked systemic weight loss and liver injury.MCD feeding caused more macrovesicular fat droplets and fat accumulation in the livers of HBs-Tg mice than in wild-type C57BL/6 mice.In addition,within 30 days of MCD exposure,more PCNA-positive nuclei were found in the livers of HBs-Tg mice.CONCLUSIONS:HBs-Tg mice fed with a lipogenic MCD form more macrovesicular fat droplets earlier,coincident with more hepatocyte proliferation,resulting in the appearance of increased susceptibility to experimental steatohepatitis in these mice.

EFFECTS OF NH_4Cl ON THE INTERACTION BETWEEN POLY(ETHYLENE OXIDE) AND IONIC SURFACTANTS IN AQUEOUS SOLUTIONS

The interaction of poly(ethylene oxide)(PEO)with the ionic surfactants,sodium dodecylsulfate(SDS)and cetyltrimethylammonium chloride(CTAC)respectively,in aqueous solutions containing a certain concentration of NH_4Cl, is studied by the viscosity measurement.It has been found that the ion-dipole interaction between PEO and ionic surfactants is changed considerably by the organic salt.For anionic suffactant of SDS,the addition of NH_4Cl into solution strengthens the interaction between PEO and the headgrou...

Rapid synthesis of biodegradable poly(epsilon-caprolactone-co-p-dioxanone) random copolymers under microwave irradiation

Biodegradable poly(epsilon-caprolactone-co-p-dioxanone)(PCDO) random copolymers have been synthesized by ring-opening polymerization of epsilon-caprolactone(CL) and p-dioxanone(PDO) under microwave irradiation.The effects of irradiation time and different CL/PDO molar feed ratios on the microwave-assisted ring-opening polymerization(MROP) of PCDO have been discussed.The resultant products were characterized by ~1H NMR,GPC and DSC.It was found that the polymerization was completed within 20 min at 140℃.In...

A DISLOCATION-MECHANICS-BASED CONSTITUTIVE MODEL FOR DYNAMIC STRAIN AGING

Dynamic strain aging（DSA）is an important phenomenon in solute hardened metals and seri-ously affects the mechanical properties of metals.DSA is generally induced by the interaction between themoving dislocations and the mobile solute atoms.In this paper,only the interaction between moving disloca-tions and mobile solute atoms in a dislocation core area（core atmosphere）will be taken into account.To es-rablish the constitutive model which can describe the DSA phenomenon,we improved the Zerilli-Armstrongdislocation-mechanics-based thermal viscoplastic constitutive relation,and added the effect of the interactionbetween the moving dislocations and core atmosphere.Because the constitutive relation estabhshed is basedon the Zerilh-Armstrong relation,it can describe not only the DSA phenomenon,but also the mechanical be-havior of metals over a broad range of temperatures（77K～1000K）and strain rate(10-4～104 s-1).Themodel prediction for tantalum fits well with the experimental data.

Resource Allocation based on Shared Criterion in OFDMA Distributed Radio Access Network

Distributed radio access network (DRAN) is a novel wireless access architecture and can solve the problem of the available spectrum scarcity in wireless communications. In this paper, we investigate resource allocation for the downlink of OFDMA DRAN. Unlike previous exclusive criterion based algorithms that allocate each subcarrier to only one user in the system, the proposed algorithms are based on shared criterion that allow each subcarrier to be allocated to multiple users through different antennas and to only one user through same antenna. First, an adaptive resource allocation algorithm based on shared criterion is proposed to maximize total system rate under each user's minimal rate and each antenna's maximal power constraints. Then we improve the above algorithm by considering the influence of the resource allocation scheme on single user. The simulation results show that the shared criterion based algorithm provide much higher total system rate than that of the exclusive criterion based algorithm at the expense of the outage performance and the fairness, while the improved algorithm based on shared criterion can achieve a good tradeoff performance.

Study on New Spectrophotometric Determination of Vanadium(V) with Chlorpromazine

By using chlorpromazine as a new color reagent, spetrophotometric reactions with vanadium(V) have been studied. In the medium of 0.25 mol·L-1 of H2SO4 chlorpromazin reacts with vanadium(V) at room temperature to form a bright red complex, which exhibits a maximum absorption at 520 nm. Beer’s law is obeyed in the concentration range of 0-2μg and 2-40μg V(V)/10mL with molar absorptivities of 5. 10×103 and 1.02×104L·mol-1·cm-1,

Oxidative Coupling of Phenols by2，2，6，6－Tetramethyl－4－methoxypiperidine OxoammoniumChloride

ＯｘｉｄａｔｉｖｅＣｏｕｐｌｉｎｇｏｆＰｈｅｎｏｌｓｂｙ２，２，６，６－Ｔｅｔｒａｍｅｔｈｙｌ－４－ｍｅｔｈｏｘｙｐｉｐｅｒｉｄｉｎｅＯｘｏａｍｍｏｎｉｕｍＣｈｌｏｒｉｄｅＯｘｉｄａｔｉｖｅＣｏｕｐｌｉｎｇｏｆＰｈｅｎｏｌｓｂｙ２，２，６，６－Ｔｅｔ...

Network Fault Analysis from Passive Measurement

A new passive method for automatic discovery and location of network failure is proposed.This method employs a passive measurement to collect information and events from network traffic,and employs a model-based reasoning system to detect and locate network faults.Measurement points are deployed in a backbone network to capture the traffic and then evaluate the Quality of Service(QoS) metrics of end-to-end IP conversations.A routing model is also established for the observed network to simulate the attributes and activities of routers and links.This routing model also deduces the routing path for each IP conversation,and thus the QoS metrics of IP conversations are mapped into the metrics of paths.With the information of shared links of overlapping paths and network tomography technique,the QoS metrics of links can also be estimated,and the poorly rated links are picked out as failure points.This method is implemented in a tool named FaultMan,which is deployed in a campus network.Test results have shown its availability in middle-scale networks.

Asymmetric Reformatsky Reaction Induced by Dipeptides

For the first time, synthetic dipeptides were applied to the catalysis of asymmetric Reformatsky reaction. Review in this domain & factors influencing enantioselectivity were discussed.

A Molecular Modeling for the Complexation of Cyclobis(paraquat-p-phenylene) with Substituted Benzenes and Biphenyls

Molecular orbital PM3 calculation was performed on the complexation of cyclobis(para-quat-p-phenylene) with a number of 1,4-disubstituted benzenes and biphenyl derivatives. A fair correlation was found between the PM3 calculated binding energies and the experimental ones, which enabled the PM3 calculation to predict the experimental binding energies for a number of important complexes. A good structure-activity relationship was also found between the PM3 calculated binding energies and the substituent molar refraction Rm and Hammett σ constants, indicating that the van der Waals force and the electronic interactions constituted the major driving forces for the complexation of cyclobis(paraquat-p-phenylene).

AN EXPERIMENTAL STUDY OF DYNAMIC TENSILE PROPERTIES OF GLASS FIBER AT LOW-TEMPERATURES

Tensile impact experiments of EC8.0-24×7 glass fiber bundles at different low tempera-tures T（14℃,-40℃ and-100℃）and strain rates ε were carried out,and complete stress-strain curveswere obtained.Within the range of the experiment temperatures and strain rates,it is found that the initialmodulus E,the ultimate strength σmaxand the unstable strain εb of the glass fiber bundles all increase withat an identical T.At an identical ε,with the decrease of T,E and σmaxincrease; but εb increases when14℃】T】-40℃ and decreases when-40℃】T】-100℃.The strain-rate-and temperature-depen-dent bimodal Weibull statistical constitutive theory was adopted for the statistical analysis of the experimentalresults,and the Weibull parameters of single fiber were obtained.The results show that the bimodal Weibulldistribution function is suitable to represent the strength distribution of the glass fiber at low temperature anddifferent strain rates.The differences in the mechanical properties between EC8.0-24×7 and EC5.5-12×14 glass fiber bundles were also discussed.

Hierarchical Spectrum Sharing Networks

A spectrum heterogeneity analysis in the cognitive radio network is conducted in this paper. Subsequently,a spectrum-heterogeneity-based hierarchical spectrum sharing(HSS) network for cognitive radio is proposed.The corresponding method of classifying available spectrums and communication based on the proposed architecture is also presented. Based on the above network architecture,we propose a reference protocol architecture.Research on these protocol function blocks,such as spectrum sensing,spectrum manager,and so on,is conducted. Numerical results show that HSS can provide a considerable extension to available spectrums so that the spectral utility may be further improved.

Synthesis of Novel Lipids Bearing Cholesteryl Group as Gene Vectors

Some cationic and neutral lipids bearing cholesteryl group were synthesized as gene vectors, and the structures of the compounds were characterized by IR, 1HNMR, MS and elemental analysis.

An USB-based time measurement system

In this paper,we report the electronics of a timing measurement system of PTB(portable TDC board), which is a handy tool based on USB interface,customized for high precision time measurements without any crates. The time digitization is based on the High Performance TDC Chip(HPTDC).The real-time compensation for HPTDC outputs and the USB master logic are implemented in an ALTERA's Cyclone FPGA.The architecture design and logic design are described in detail.Test of the system showed a time resolution of 13.3 ps.

A FINITE DEFORMATION ANALYSIS OF POLYCRYSTAL BY CONSIDERING THE INFLUENCE OF GRAIN BOUNDARY

By combining grain boundary(GB)and its influence zone,a micromechanic model forpolycrystal is established for considering the influence of GB.By using the crystal plasticity theory andthe finite element method for finite deformation,numerical simulation is carried out by the model.Calculated results display the microscopic characteristic of deformation fields of grains and are in quali-tative agreement with experimental results.