Predicting the Acute Toxicity of Aromatic Amines by Linear and Nonlinear Regression Methods

In current paper, a quantitative structure-activity relationship （QSAR） study was performed for the prediction of acute toxicity of aromatic amines. A set of 56 compounds was randomly divided into a training set of 46 compounds and a test set of 10 compounds. The electronic and topological descriptors computed by the Scigress package and Dragon software were used as predictor variables. Multiple linear regression （MLR） and support vector machine （SVM） were utilized to build the linear and nonlinear QSAR models, respectively. The obtained models with five descriptors show strong predictive ability. The linear model fits the training set with R2 = 0.71, with higher SVM values of R2 = 0.77. The validation results obtained from the test set indicate that the SVM model is comparable or superior to that obtained by MLR, both in terms of prediction ability and robustness.

Structural Design and Numerical Analysis of a Novel Biodegradable Zinc Alloy Stent

Biodegradable zinc alloy stents are a prospective solution for complications caused by the incompatibility between artery and permanent stents.However,insufficient scaffolding has limited the clinical application of biodegradable zinc alloy stents.Therefore,in this study,a new stent concept was designed to improve the scaffolding.The mechanical performances of the new and a traditional design stent were investigated and compared using finite element analysis(FEA).The new and traditional design stent were expanded to the intended radial displacement of 0.24 mm under the expansion pressure of 0.58 MPa and 0.45 MPa,respectively.Then,a pressure load of 0.35 MPa was exerted on the outer surfaces of the two stents to compress them.The results showed that the radial recoiling ratio were 45.3%and 83.3%for the new and the traditional stent,respectively.The simulations demonstrate that the biodegradable zinc alloy stent offers enhanced support because of the new structural design.This study implies that biodegradable zinc alloy stent can be a new competitive intervention device for the future clinical cardiovascular application.

Preparation, Characterization and in vitro Release of Chitosan-stavudine Conjugate Nano-prodrug

Chitosan-stavudine （d4T） conjugate with a succinic spacer was synthesized via carbodiimide coupling reaction and structurally characterized. In order to nanosize it for improving its therapeutic properties, the chitosan-5＇-O-succinyl-d4T conjugate was crosslinked with sodium tripolyphosphate （TPP） to obtain the chitosan-d4T conjugate nano-prodrug. The morphologies of chitosan-d4T conjugate nanoparticles were observed by transmission electron microscopy （TEM）, and their zeta potential, particle size, and polydispersity （size distribution） were measured by the dynamic light scattering （DLS） techniques. In vitro drug release studies at pH 1.1 and pH 7.4 indicate that the crosslinked chitosan-d4T conjugate nano-prodrug can prevent the coupled d4T from leaking out before entering the target viral reservoirs and provide a mild sustained release without the burst release. The results reveal that constructing conjugated chitosan nano-prodrugs may be a promising approach for improving the therapy efficacy of drugs in antiviral treatment.

Immunogenicity of DNA and Recombinant Sendai Virus Vaccines Expressing the HIV-1 gag Gene

Combinations of DNA and recombinant-viral-vector based vaccines are promising AIDS vaccine methods because of their potential for inducing cellular immune responses. It was found that Gag-specific cytotoxic lymphocyte (CTL) responses were associated with lowering viremia in an untreated HIV-1 infected cohort. The main objectives of our studies were the construction of DNA and recombinant Sendai virus vector (rSeV) vaccines containing a gag gene from the prevalent Thailand subtype B strain in China and trying to use these vaccines for therapeutic and prophylactic vaccines. The candidate plasmid DNA vaccine pcDNA3.1(+)-gag and recombinant Sendai virus vaccine (rSeV-gag) were constructed separately. It was verified by Western blotting analysis that both DNA and rSeV-gag vaccines expressed the HIV-1 Gag protein correctly and efficiently. Balb/c mice were immunized with these two vaccines in different administration schemes. HIV-1 Gag-specific CTL responses and antibody levels were detected by intracellular cytokine staining assay and enzyme-linked immunosorbant assay (ELISA) respectively. Combined vaccines in a DNA prime/rSeV-gag boost vaccination regimen induced the strongest and most long-lasting Gag-specific CTL and antibody responses. It maintained relatively high levels even 9 weeks post immunization. This data indicated that the prime-boost regimen with DNA and rSeV-gag vaccines may offer promising HIV vaccine regimens.

Isolation and Identification of a Nitrite-oxidizing Bacterium from Hepu County

In order to select the strain that can degrade nitrite, the screening plate with nitrite was used as the sole nitrogen source to screen the strain with ability to degrade nitrite. A strain with nitrite degrading capacity was isolated from the sludge of a shrimp-farming pond in Hepu City, Guangxi Zhuang Autonomous Region. The isolated strain was identified based on colonial morphology, physiological and biochemical characteristics, and 16S rRNA sequence. Results showed that the strain could grow well on the culture medium containing 2.3 g/L nitrite. According to the morphological characteristics, nitrogen source requirements and evolutionary tree of the 16S rRNA sequence, the isolated strain was identified as Acinetobacter radioresistens, which was named HPAR132 strain. This study laid the foundation for further investigation of nitrite-oxidizing bacterium HPAR132.

Synthesis and Biological Activities of Quinoline Derivatives as HIV-1 Integrase Inhibitors

Based on the structure of the integrase core domain and pharmacophore perception, the authors picked out the hit quinolone derivative 1 as the lead compound via virtual screen in ACD, MDDIL NCI and Chinese Herb three-dimensional database with the aid of DOCK4.0 program and synthesized a series of analogues of compound 1. Their primary anti-HIV properties against integrase reveal that 6-position methyl group on the benzene ring of quinolone plays a more important role than chlorine, 7-position methyl group or no substituted group. But the title compounds exhibit little difference When the substituted group was phenyl or thienyl on the pyridine ring of quinoline.

Isolation and Identification of a Cellulose-degrading Bac- terium from Paddy Soils in Chengdu City

In this study, a cellulose-degrading bacterium was isolated from paddy soils in Chengdu City. After 2 d of culture, the average diameter of hydrolytic circles on CMC-Congo red medium was 26 -30 mm. Single colonies on LB plates were white and wrinkled. The isolated strain was identified as a Gram-negative bacterium by Gram staining, which could produce short red-like spores. Colony PCR was performed using the bacterial 16S rDNA universal primers. A 1 429 kb DNA fragment was amplified. Based on sequence homology analysis and comprehensive analysis, the isolated strain was identified as Bacillus velezensi, which was named CDBV62 according to the origin.

The Hemodynamic Study on the Effects of Entry Tear and Coverage in Aortic Dissection

Nowadays,cardiovascular disease has gradually become the number one killer of human health.The Stanford type-A aortic dissection is a relatively common cardiovascular disease with potential hazards.The disease is caused by a partialtearing of the aortic intima.Thoracic endovascular aortic repair(TEVAR)is one of the most effective treatment for type A aortic dissection and has been widely used clinically to achieve thrombosis and reduce pressure by covering the incision tear in the FL.However,the effect of entry tear location on type-A aortic dissection and the prognosis of TEVAR intervention are unclear.In this work,the hemodynamic effects of the type-A aortic dissection in different entry and covering entry tear position were mainly studied.It can provide a new method or idea in the field of the aortic dissection hemodynamics,which is of great significance to provide a basic theoretical research on the development of aortic dissection in the aspect of clinical judgment.Two type-A aortic dissection models with different entry tear positions(Model 1:the entry tear was located at the entrance of the ascending aorta,Model 2:the entry tear was located at the starting position of the descending aorta)were reconstructed according to the computed tomography(CT)images of the patients.In our study,the thoracic aortic endovascular repair was simulated by covering the entry tear(Model 3).Then,the semi-automatic adaptive technology HyperMeshl0.0(Altair HyperWorks,Troy,Ml,USA)mesh generator was used to generate the high-quality tetrahedral 3D mesh.To clarify the hemodynamic effects of entry tear and coverage in aortic blood flow pattern,the comparative study on the true lumen(TL)and false lumen(FL)blood flow patterns of three models were carried out numerically(the time-dependent pulsatile waveform of pressure boundary conditions used at the aortic inlet were consistent with Rapezzis’s work,time-dependent pulsatile waveform of velocity at the descending aorta outlet and the time-dependent pulsatile waveform of pressure at the brachiocephalic artery,left common carotid artery,and left subclavian artery were obtained from the work of Olufsenet et al).The velocity vector,flow ratio,pressure,time-average wall shear stress(TAWSS)and relative residence time(RRT)were calculated to evaluate the hemodynamic changes.The results of this work indicated that(Ⅰ)the velocity was higher at the entry tear in aorta entrance;(Ⅱ)the helical development of the TL and FL might be related to the helical nature of aortic arch;(Ⅲ)the blood flow which passing the FL of Model 1,Model 2 and Model 3 in one cardiac cycle were approximately 26.63%,13.39%and 1%,respectively;(Ⅳ)the difference in intima wall pressure among the TL and FL was found varied a lot and shown a strong pulsation;(Ⅴ)the TAWSS distribution in TL and FL were quite different(the TAWSS in TL intima>8 Pa,the TAWSS in FL intima<4 Pa).In brief,the aortic morphology and location of the entry tear were found to have a significant effect on the hemodynamic of the aortic dissection.What’s more,we found that the risk of the aortic rupture could be higher if the position of entry tear is closer to the ascending aorta.By covering the entry tear to simulate TEVAR,the pressure of FL was reduced,which could provide some help for the treatment of early retrograde type-A dissection.

Functional connectivity and information flow in cerebral motor regions of healthy people following finger movement training

BACKGROUND：Neuro-rehabilitative training has been shown to promote motor function recovery in stroke patients,although the underlying mechanisms have not been fully clarified.OBJECTIVE：To investigate the effects of finger movement training on functional connectivity and information flow direction in cerebral motor areas of healthy people using electroencephalogram （EEG）.DESIGN,TIME AND SETTING：A self-controlled,observational study was performed at the College of Life Science and Bioengineering,Beijing University of Technology between December 2008 and April 2009.PARTICIPANTS：Nineteen healthy adults,who seldom played musical instruments or keyboards,were included in the present study.METHODS：Specific finger movement training was performed,and all subjects were asked to separately press keys with their left or right hand fingers,according to instructions.The task comprised five sessions of test train test train-test.Thirty-six channel EEG signals were recorded in different test sessions prior to and after training.Data were statistically analyzed using one-way analysis of variance.MAIN OUTCOME MEASURES：The number of effective performances,correct ratio,average response time,average movement time,correlation coefficient between pairs of EEG channels,and information flow direction in motor regions were analyzed and compared between different training sessions.RESULTS：Motor function of all subjects was significantly improved in the third test comparedwith the first test （P〈 0.01）.More than 80% of connections were strengthened in the motor-related areas following two training sessions,in particular the primary motor regions under the C4 electrode.Compared to the first test,a greater amount of information flowed from the Cz and Fcz electrodes （corresponding to supplementary motor area） to the C4 electrode in the third test.CONCLUSION：Finger task training increased motor ability in subjects by strengthening connections and changing information flow in the motor areas.These results provided a greater understanding of the mechanisms involved in motor rehabilitation.

Immunological Responses to the Combination of EBNA1 and LMP2 in Mice

Epstein-Barr virus (EBV) infection is closely associated with nasopharyngeal carcinoma (NPC)and considered one of the major risk factors[1]. A limited number of viral proteins, such as latent membrane proteins (LMP1, LMP2) and EB nuclear antigen1 (EBNA1), are expressed in NPC cells[2].Recognition epitopes for CD8+and CD4+T cells were included in the LMP2 antigen and EBNA1 C-terminal region (amino acid No. 380-641), respectively[3,4].Both CD4+and CD8+memory T-cell responses were efficiently reactivated by EBNA1 and LMP2[5;6].

Synthesis and Crystal Structure of Tetraethyl syn-1,5,8,8bβ-Tetrahydrocyclobuta[1,2-b:3,4-b']dipydine-3,4aβ,7,8aβ(4H,4bβH)-tetracarboxylate

The synthesis of syn-photodimer from 1,4-dihydropyridine without 4-aryl was studied, and its single crystal was obtained （C22H30N2O8, Mr= 450.48）. It crystallizes in monoclinic, space group P21/c with a = 11.937（2）, b = 20.913（4）, c = 9.763（2） A,β = 108.46（3）°, V= 2311.9（8） ,A^3, Z= 4, Dc = 1.294 g/cm^3,/7（000） = 960,μ = 0.099 mm^- 1, R = 0.0640 and wR = 0.1464 for 4077 unique reflections with 1598 observed ones （I 〉 2σ（I）. It is shown that the whole molecular structure of the title compound is a twist-boat conformation, and the two double bonds have a trend of potential intramolecular reaction under high-energy irradiation.

Double-endpoint Genotoxicity Quantification and PAHs Characterization of Drinking Water Source alongside Polluted Yinghe River with High Tumor Mortality

The etiology for the high tumor mortality in heavy polluted Yinghe river basin is still unclear and polycyclic aromatic hydrocarbons(PAHs)belong to the priority pollutants in water based on the former surveillance data.In order to explore the potential genotoxicants contributing to the double-endpoint genotoxicity of polluted drinking water source,12 groundwater and 3 surface water samples were collected from 3 villages and the nearby rivers alongside Yinghe river basin,respectively and their comprehensive genotoxicity was estimated with a bioassay group of sOS/umu test and micronucleus(MN)test(MNT).Some groundwater samples showed positive genotoxicity and all surface water samples were highly genotoxic.Eight groundwater samples showed DNA genotoxic effct with the average 4-NQO equivalent concentration(TEQ_(4-NQO))of 0.067μg/L and 0.089μg/L in wet and dry season,respectively.The average MN ratios of groundwater samples were 14.19‰ and 17.52‰ in wet and dry season,respectively.Groundwater samples showed different genotoxic effect among 3 villages.The total PAHs concentrations in all water samples ranged from 8.98 to 25.17 ng/L with an average of 14.97±4.85 ng/L.BaA,CHR,BkF,BaP and DBA were the main carcinogenic PAHs contributing to the genotoxicity of water samples.In conclusion,carcinogenic PAHs are possibly related to the high tumor mortality in the target area.Characterization of carcinogenic PAHs to genotoxicity of drinking water source may shed light on the etiology study for high tumor mortality in Yinghe river basin.Key words:genotoxicity test;drinking water source;high tumor mortality;Yinghe river basin;polycyclic aromatic hydrocarbons(PAHs)

Weighted single-step GWAS and RNA sequencing reveals key candidate genes associated with physiological indicators of heat stress in Holstein cattle

Background: The study of molecular processes regulating heat stress response in dairy cattle is paramount for developing mitigation strategies to improve heat tolerance and animal welfare. Therefore, we aimed to identify quantitative trait loci(QTL) regions associated with three physiological indicators of heat stress response in Holstein cattle, including rectal temperature(RT), respiration rate score(RS), and drooling score(DS). We estimated genetic parameters for all three traits. Subsequently, a weighted single-step genome-wide association study(WssGWAS) was performed based on 3200 genotypes, 151,486 phenotypic records, and 38,101 animals in the pedigree file. The candidate genes located within the identified QTL regions were further investigated through RNA sequencing(RNA-seq) analyses of blood samples for four cows collected in April(non-heat stress group) and four cows collected in July(heat stress group).Results: The heritability estimates for RT, RS, and DS were 0.06, 0.04, and 0.03, respectively. Fourteen, 19, and 20 genomic regions explained 2.94%, 3.74%, and 4.01% of the total additive genetic variance of RT, RS, and DS, respectively. Most of these genomic regions are located in the Bos taurus autosome(BTA) BTA3, BTA6, BTA8, BTA12, BTA14, BTA21, and BTA24. No genomic regions overlapped between the three indicators of heat stress, indicating the polygenic nature of heat tolerance and the complementary mechanisms involved in heat stress response. For the RNA-seq analyses, 2627 genes were significantly upregulated and 369 downregulated in the heat stress group in comparison to the control group. When integrating the WssGWAS, RNA-seq results, and existing literature, the key candidate genes associated with physiological indicators of heat stress in Holstein cattle are: PMAIP1, SBK1, TMEM33, GATB, CHORDC1, RTN4IP1, and BTBD7.Conclusions: Physiological indicators of heat stress are heritable and can be improved through direct selection. Fifty-three QTL regions associated with heat stress indicators confirm the polygenic nature and complex genetic determinism of heat tolerance in dairy cattle. The identified candidate genes will contribute for optimizing genomic evaluation models by assigning higher weights to genetic markers located in these regions as well as to the design of SNP panels containing polymorphisms located within these candidate genes.

Interaction of bovine serum albumi with two alkylimidazolium-based ionic liquids investigated by microcalorimetry and circular dichroism

The interactions of bovine serum albumin (BSA) with two alkylimidazolium-based ionic liquids, 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim]BF4) and 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim]PF6), in buffer solutions at pH 7.0 were investigated by isothermal titration calorimetry (ITC) and circular dichroism (CD). CD spectra showed that the two ionic liquids changed the secondary structure of BSA. Data process was based on the supposition that there were several independent types of binding sites on each BSA molecule for the two ligand molecules. The results obtained by using this supposition combined with Langmuir adsorption model showed that there were two types of such binding sites. One was the high affinity binding site, and the other was the low affinity binding site. The binding constants, changes in enthalpy, entropy and Gibbs free energy for the two types of binding were obtained, which showed that the two types of binding were driven by a favorable entropy increase. Furthermore, for either the ionic liquids, the number of the high affinity binding sites is much smaller than that of the low affinity ones. These results were interpreted with the molecular structure of BSA and the different substituent groups on imidazole ring of the two ionic liquid molecules.

Computational studies on the interactions of nanomaterials with proteins and their impacts

The intensive concern over the biosafety of nanomaterials demands the systematic study of the mechanisms underlying their biological effects. Many of the effects of nanomaterials can be attributed to their interactions with proteins and their impacts on protein function. On the other hand, nanomaterials show potential for a variety of biomedical applications,many of which also involve direct interactions with proteins. In this paper, we review some recent computational studies on this subject, especially those investigating the interactions of carbon and gold nanomaterials. Beside hydrophobic andπ-stacking interactions, the mode of interaction of carbon nanomaterials can also be regulated by their functional groups.The coatings of gold nanomaterials similarly adjust their mode of interaction, in addition to coordination interactions with the sulfur groups of cysteine residues and the imidazole groups of histidine residues. Nanomaterials can interact with multiple proteins and their impacts on protein activity are attributed to a wide spectrum of mechanisms. These findings on the mechanisms of nanomaterial–protein interactions can further guide the design and development of nanomaterials to realize their application in disease diagnosis and treatment.

Synthesis of 6-sulfamoyl-4-oxoquinoline-3-carboxylic acid derivatives as integrase antagonists with anti-HIV activity

一系列新奇 6-sulfamoyl-4-oxoquinoline-3-carboxylic 酸衍生物为 HIV integrase 抑制活动被综合了并且屏蔽。他们的结构被 ESIMS 证实， 1 H NMR 和 13 C NMR。

Effect of Plaque Composition on Biomechanical Performance of a Carotid Stent: Computational Study

Clinical application of bare metal stents is constrained by the occurrence of instent restenosis,mainly due to the complex biomechanical environment in the body.Numerical simulation method was used to evaluate the effect of plaque composition on stent performance in a carotid artery.CT angiography(CTA)data were used as a reference,and zero-load state of the carotid artery was used to establish a 3D stenotic artery model.Different plaque compositions,calcified and hypo-cellular were defined in Model 1 and Model 2,respectively.Interactions between the stents and arterial tissues within the stent crimping-expansion process were analyzed to explore the effects of plaque composition on the mechanical parameters of carotid stents.Goodman diagram and fatigue safety factor(FSF)were analyzed to explore the effects of plaque composition on fatigue performance of a carotid stent in the stent service process.In the stent crimping-expansion process,the von Mises stress in the stent and the dog-boning ratio in Model 1 were higher than that in Model 2.The calcified plaque prevented the stent from expanding the stenotic vessel to a pre-set diameter.Thus,the risk of rupture in the calcified plaque was higher than that in the hypo-cellular plaque.Plaque also affected the stress/strain in the vessel wall,which was observed to be lower in Model 1 than in Model 2.This indicated that calcified plaque could decrease the stress-induced injury of arterial tissues.Within the stent service process,the stents used in these two models were predicted to not fail under fatigue rupture as calculated by the Goodman diagram.Additionally,the points closer to the fatigue limit were generally observed at the inner bend of the stent crowns.The FSF of the stent in Model 1 was lower than that in Model 2.The stent operating in the presence of calcified plaques suffered high risk of fractures.Reliability and fatigue performance of the stent were found to be associated with plaque composition.Hence,this study may provide stent designers an approach toward enhancing the mechanical reliability of a stent.

Study on the Arsenic Content of Ophiocordyceps sinensis in Sichuan Province

[Objectives] To investigate the characteristics of arsenic content of Ophiocordyceps sinensis in Sichuan Province. [Methods]Using ICP-MS( Inductively Coupled Plasma-Mass Spectrometry),we studied the 30 samples of O. sinensis from 25 places of production in Sichuan Province as well as the arsenic content in the habitat soil. [Results] The arsenic content of O. sinensis in Sichuan Province was0. 62-9. 16 mg/kg; the arsenic content in habitat soil was 3. 93-59. 90 mg/kg. [Conclusions]90% of O. sinensis products from Sichuan Province exceeded the arsenic content limit of 1 mg/kg in the health food,and as a comparison,the arsenic content of samples from Qinghai,Tibet,Gansu was over the limit.

A ECG Tele-monitoring Method and System Based on Embedded Web Server

This paper describes the development of a new ECG tele-monitoring method and system based on the embedded web server. The system consists of ECG recorders with network interface and the embedded web server, internet networks and computers, with the system operating on browser/server(B/S) mode. The ECG recorder was designed by ARM9 (S3C2410X) and embedded operating system (Linux). Once the ECG recorder has been connected to the internet network, medical experts can use the internet to access the server of the ECG recorder, monitor ECG signals, and diagnose patients by browsing the dynamic web pages in the embedded web server. The experimental results reveal that the designed system is stable, reliable, and suitable for the use in real-time ECG tele-monitoring for both family and community health care.

Review of the Eilema group of lichen moths from South Korea,with description of one new species(Lepidoptera:Erebidae:Arctiinae:Lithosiini)

This review details Eilema group in the subfamily the Korean species of the Arctiinae of Erebidae： 19 species in five genera （Manulea, Collita, Katha, Dolgoma, and Wittia）, a new species （Collita hwacheonensis Bayar- saikhan ＆ Bae, sp. nov.）, and an unrecorded species [C. vetusta aegrota （Butler 1877）]. All species are diagnosed, and figures of the adults and genitalia and a key to species based on male genital structure of Eilema group in South Korea are included.