原状湿陷性黄土的结构性本构模型

研究目的:黄土的应力和含水率状态对应着一定的结构状态,微观结构性的改变,引起宏观力学性状的改变。湿陷性黄土在力与水的共同作用下,产生原生结构性的损伤和湿陷变形,对增湿和加荷耦合作用下的结构性变化规律,应力应变关系和增湿变形等力学特性的研究有重要的意义。研究结论:不同含水率和固结围压条件下原状结构性黄土的应力应变变化规律,以及由增湿、固结作用和剪切变形反映了土体结构性损伤规律;统一考虑增湿和加荷对土体结构的损伤破坏,建立的反映结构性变化的非线性本构模型,能够描述应变软化和硬化型应力应变关系曲线,实现了土的结构性与其本构模型研究的统一。

原状Q_3黄土在加载和湿陷过程中细观结构动态演化的CT–三轴试验研究

为了揭示原状Q3黄土在加载和湿陷过程中的细观结构变化,将湿陷三轴仪与医用CT机相配套,进行了一系列控制吸力的CT-三轴湿陷试验,不仅得到了加载过程和湿陷过程中的宏观反应曲线,而且得到了相对应的CT扫描图像。结果表明:原状湿陷性黄土具有较强的初始结构性;加载过程中,较大的孔洞先扩展后闭合,小孔洞逐渐闭合;湿陷过程中,大部分孔洞逐渐闭合且断面的密度分布趋于均匀;湿陷过程中大孔洞闭合与否取决于浸水时的应力状态。通过宏细观试验资料的分析,确定了原状湿陷性黄土的结构屈服应力,提出了一个基于CT数均值的结构性参数,分别定义了加载和湿陷过程中的结构损伤变量,研究了它们的变化规律,建立了结构损伤演化方程。

原状泥岩膨胀变形试验及计算模型研究

高铁无砟轨道对路基上拱要求极为严格,泥岩地基遇水后将导致路基上拱,进而影响到高速铁路行车的安全性。以兰新高铁一典型路基上拱地段地基泥岩为研究对象,开展了2 cm、4 cm和6 cm共3种不同高度,10 k Pa、20 kPa、30 k Pa、40 k Pa和50 k Pa共5种上覆荷载,以及5.5%、7.5%、9.5%、11.5%和13.5%共5种含水率下的膨胀变形试验。试验结果表明:原状泥岩膨胀量随吸水率增大而增大;上覆荷载对膨胀量起抑制作用,当荷载较小时,抑制作用较弱,荷载较大时抑制作用较强;原状泥岩高度越大,膨胀量越大,且膨胀量与高度不成比例增加;建立了综合考虑泥岩上覆荷载、含水率和高度耦合作用下膨胀量计算模型,模型计算结果与实测数据吻合较好,具有一定推广性。

结构性黄土的修正Duncan-Chang模型

为了实现原状湿陷性黄土结构性与其本构模型研究的统一,解决软化型应力-应变曲线的切线刚度矩阵正定性问题,通过研究原状结构性黄土在不同含水率和固结围压条件下由增湿、固结作用和剪切变形引起的结构性损伤规律,建立可以反映结构性变化的修正非线性Duncan-Chang模型.该模型考虑了增湿和加荷对土体结构的损伤破坏,把含水率作为一个重要的变量,用一族具有相同初始切线模量和不同极限强度的双曲线来求取当前应变状态处的切线模量,能够统一描述结构性黄土的应变软化和硬化型应力-应变关系曲线,形成解决原状湿陷性黄土增湿和应力耦合条件下变形及强度计算问题的新方法.

汶川地震断裂带科学钻探一号孔(WFSD-1)不同取心方法的应用效果分析

针对因地震造成的复杂地层,在汶川地震断裂带科学钻探一号孔(WFSD-1)钻探施工中,为了保证岩心的采取率和原状性,满足地震机理研究需要,长孔段采用多型号多规格半合管取心工艺技术,确保全孔岩心采取率高达94.3%及岩心原状性好的目的,从而满足了汶川地震地学研究的需要。

First-principles thermodynamics of metal-oxide surfaces andinterfaces:A case study review

An important step for achieving the knowledge-based design freedom on nano-and interfacial materials is attained by elucidating the related surface and interface thermodynamics from the first principles so as to allow engineering the microstructures for desired properties through smartly designing fabrication processing parameters.This is demonstrated for SnO2 nano-particle surfaces and also a technologically important Ag-SnO2 interface fabricated by in-situ internal oxidation.Based on defect thermodynamics,we first modeled and calculated the equilibrium surface and interface structures,and as well corresponding properties,as a function of the ambient temperature and oxygen partial pressure.A series of first principles energetics calculations were then performed to construct the equilibrium surface and interface phase diagrams,to describe the environment dependence of the microstructures and properties of the surfaces and interfaces during fabrication and service conditions.The use and potential application of these phase diagrams as a process design tool were suggested and discussed.

Principal Component Analysis on Traits Related to Lodging Resistance of Plateau Japonica Rice

Objective] This study was conducted to investigate the main factors affect-ing the lodging resistance of plateau japonica rice. [Method] Twenty agronomic traits related to lodging resistance of plateau japonica rice were analyzed by principal component analysis and correlation analysis among 26 varieties/lines of plateau japonica rice. [Result] The lodging resistance of the 26 varieties/lines had great dif-ference among different agronomic traits. Plant height, and wal thickness of the 4th, 3rd and 2nd internodes under the panicle had the most important influence on lodging resistance, while the diameter of the 3rd, 2nd, 4th, 1st nodes under the panicle, length of the 4th and 3rd internodes under the panicle, wal thickness of the 1st internode under the panicle had less influence. The other nine agronomic traits of rice culm did not affect or indirectly affected lodging resistance through above-mentioned agro-nomic traits. Lodging resistance had significant correlations with plant height, length of the 4th and 3rd internodes under the panicle, wal thickness of the 1st, 2nd, 3rd and 4th internodes under the panicle and diameter of the 1st, 2nd, 3rd and 4th node sunder the panicle, had insignificant correlations with panicle length, panicle weight, length of the 1st and 2nd internodes under the panicle, diameter of the 1st, 2nd, 3rd and 4th internodes under the panicle, diameter of the 5th node under the panicle. [Conclu-sion] More attention should be paid to the main factors affecting lodging resistance in breeding to improve lodging resistance of plateau japonica rice.

Changes of the Transcriptional Levels of Molecules Associated with Endogenous Antigen Processing and Presentation in Porcine Skin-derived Dendritic Cells Infected with PCV2 in vivo

[Objective] This study aimed to investigate the changes of the transcriptional levels of molecules associated with endogenous antigen processing and presenta- tion in porcine skin-derived dendritic cells infected with PCV2 in vivo. [Method] Healthy 40-day-old Landrace piglets were infected with porcine circovirus type 2 （PCV2） and euthanized on the 34, 7rd, 14th, 21st and 35th d post inoculation （DPI）. The porcine skin-derived dendritic cells （DCs） were collected to analyze the transcrip- tional levels of molecules （LMP7, UBP, MHC-I, calreticulin） associated with endogenous antigen processing and presentation by using real-time fluorescent quantitative PCR （real-time FQ-PCR）. [Result] The results showed that the level of LMP7 mR- NAs was reduced significantly on the 3DPI （P〈0.05）; the level of UBP mRNAs was consistently up-regulated, which increased significantly on the 21DPI and 35DPI （P〈 0.05）; the level of MHC-I mRNAs was significantly down-regulated on the 7DPI （P〈 0.05）; the level of calreticulin mRNAs was up-regulated slightly without significant dif- ference. [Conclusion] PCV2 can inhibit the endogenous antigen processing and presentation ability of porcine skin-derived DCs at early stages of infection.

Capping effect of reducing agents and surfactants in synthesizing silver nanoplates

The effect of reducing agents and surfactants on controlling the silver nanoplates was studied. Two reducing agents, trisodium citrate dehydrate (TSC) and potassium tartrate, were used to reduce the AgNO3 solution. In this redox system, polyvinylpyrrolidone (PVP), sodium dodecyl sulfate (SDS) and arabic gum were served as surfactants. The results showed that reducing agents and surfactants both act as the capping agent adhering to the certain facets of silver seeds to block this surface to grow. The relative intensity of reducing agents also takes an active part in influencing the growth rate and direction of silver seeds. It was also found that halides can accelerate the speed of Ostwald ripening by adding Cl?, Br? and I?into the aqueous and have some effects on the morphology of the nanoplates.

Primary squamous cell carcinoma of the liver:A successful surgically treated case

Primary squamous cell carcinoma (SCC) of the liveris rare. Totally nine such cases have been reportedin the literature. Primary SCC of the liver has beenreported to be associated with hepatic teratoma,hepatic cyst, or hepatolithiasis. Complete remission ofpoorly differentiated SCC of the liver could be achievedby systemic chemotherapy followed by surgery orremarkably respond to hepatic arterial injection of lowdose chemotherapeutic drugs. Here we report the fi rstcase of primary SCC of the liver presenting as a solidtumor and receiving successful hepatic resection with9-mo disease free survival.

Molecular mechanisms of ＂off-on switch＂ of activities of human IDH1 by tumor-associated mutation R132H

Human cytosolic NADP-1DH （IDH1） has recently been found to be involved in tumorigenesis. Notably, the tumorderived IDH1 mutations identified so far mainly occur at Arg132, and mutation R132H is the most prevalent one. This mutation impairs the oxidative IDH activity of the enzyme, but renders a new reduction function of converting a-ketoglutarate （aKG） to 2-hydroxyglutarate. Here, we report the structures of the R132H mutant IDH1 with and without isocitrate OCT） bound. The structural data together with mutagenesis and biochemical data reveal a previ- ously undefined initial ICT-binding state and demonstrate that IDH activity requires a conformational change to a closed pre-transition state. Arg132 plays multiple functional roles in the catalytic reaction; in particular, the R132H mutation hinders the conformational changes from the initial ICT-binding state to the pre-transition state, leading to the impairment of the IDH activity. Our results describe for the first time that there is an intermediate conformation that corresponds to an initial ICT-binding state and that the R132H mutation can trap the enzyme in this conforma- tion, therefore shedding fight on the molecular mechanism of the ＂off switch＂ of the potentially tumor-suppressive IDH activity. Furthermore, we proved the necessity of Tyr139 for the gained aKG reduction activity and propose that Tyr139 may play a vital role by compensating the increased negative charge on the C2 atom of aKG during the trans- fer of a hydride anion from NADPH to aKG, which provides new insights into the mechanism of the ＂on switch＂ of the hypothetically oncogenic reduction activity of IDH1 by this mutation.

Assessment of rapid impact compaction in ground improvement from in-situ testing

Ground improvement has been used on many construction sites to densify granular materials, in other word, to improve soil properties and reduce potential settlement. This work presents a case study of ground improvement using rapid impact compaction （RIC）. The research site comprises the construction of workshop and depots as part of railway development project at Batu Gajah-Ipoh, Malaysia. In-situ testing results show that the subsurface soil comprises mainly of sand and silty sand through the investigated depth extended to 10 m. Groundwater is approximately 0.5 m below the ground surface. Evaluation of improvement was based on the results of pre- and post-improvement cone penetration test （CPT）. Interpretation software has been used to infer soil properties. Load test was conducted to estimate soil settlement. It is found that the technique succeeds in improving soil properties namely the relative density increases from 45% to 70%, the friction angle of soil is increased by an average of 3°, and the soil settlement is reduced by 50%： The technique succeeds in improving soil properties to approximately 5.0 m in depth depending on soil uniformity with depth.

Fungal genus Hypocrea/Trichoderma:from barcodes to biodiversity

Hypocrea/Trichoderma is a genus of soil-borne or wood-decaying fungi containing members important to mankind as producers of industrial enzymes and biocontrol agents against plant pathogens, but also as opportunistic pathogens of immuno- compromised humans and animals, while others can cause damage to cultivated mushroom. With the recent advent of a reliable, BarCode-aided identification system for all known taxa of Trichoderma and Hypocrea, it became now possible to study some of the biological fundamentals of the diversity in this fungal genus in more detail. In this article, we will therefore review recent progress in (1) the understanding of the geographic distribution of individual taxa; (2) mechanisms of speciation leading to development of mushroom diseases and facultative human mycoses; and (3) the possible correlation of specific traits of secondary metabolism and molecular phylogeny.

Genetic epidemiology of primary sclerosing cholangitis

The aetiology of primary sclerosing cholangitis (PSC) is not known. A more than 80-fold increased risk of PSC among first-degree relatives emphasizes the importance of genetic factors. Genetic associations within the human leukocyte antigen (HLA) complex on chromosome 6p21 were detected in PSC 25 years ago. Subsequent studies have substantiated beyond doubt that one or more genetic variants located within this genetic region are important. The true identities of these variants,however,remain to be identified. Several candidate genes at other chromosomal loci have also been investigated. However,according to strict criteria for what may be denominated a susceptibility gene in complex diseases,no such gene exists for PSC today. This review summarises present knowledge on the genetic susceptibility to PSC,as well as genetic associations with disease progression and clinical subsets of particular interest (inflammatory bowel disease and cholangiocarcinoma).

Influence of moisture content on shearing strength of unsaturated undisturbed quaternary system middle pleistocene

The unsaturated undisturbed quaternary system middle pleistocene loess,a typical unsaturated soil,often occurs in the implementation of western development strategy.To obtain the shearing strength characteristics of this unsaturated undisturbed loess,based on the analysis of mineral composition,the triaxial shear test of undisturbed quaternary system middle pleistocene loess under different moisture contents is conducted with the specialized triaxial instrument for unsaturated soil.The test results show that the mainly mineral composition of undisturbed quaternary system middle pleistocene loess is quartz and albite.Under the same confining pressure,the matric suction increases with the decrease of moisture content.The smaller the moisture content,the larger the matric suction;the higher the moisture content,the lower the matric suction.Under the same moisture content,the matric suction increases with the confining pressure and reaches a maximum when the confining pressure is 100 kPa,and then decreases with the increase of confining pressure.This phenomenon is closely related to the grain contact tightness of soil mass under high confining pressure.According to the triaxial test of loess,the sample of loess experiences 4 stages from loading to failure:1) compaction stage;2) compression stage;3) microcrack developing stage;4) shear failure stage.The test sample is of brittle failure(weak softening)under low moisture content and confining pressure.With the decrease of matric suction and the increase of consolidated confining pressure,the stress-strain curve changes from softening type to ideal plastic type.In the shearing strength parameters of unsaturated undisturbed loess,the influence of moisture content on internal friction angle is small,but that on cohesive force is obvious.Therefore,the shearing strength of unsaturated undisturbed loess is higher than that of saturated undisturbed loess and varies with the moisture content.

Dignosis and Treatment of Primary Malignant Lymphoma of the Thyroid Gland

Primary malignant lymphoma of the thyroid gland is a rare disease comprising about 1%–3% of the thyroid malignancies, and this uncommon lymphoma represent less than 1% of all non-Hodgkinlymphomas (NHL). According to the modified Ann-Arbor-Classification primary thyroid lymphoma by definition is a lymphoma that is restricted to the thyroid gland (stage I E ) or involves the thyroid gland and supradiaphragmatic predominantly adjacent thyroid lymph nodes (stage II E ). Primary thyroid lymphoma is a heterogenous disease encompassing a wide variety of lymphoma entities. The diagnosis and treatment of this lymphoma are emphasis of this article. Key words thyroid gland - lymphoma - diagnosis - treatment

Identification of Immunogenic Determinants of the Spike Protein of SARS-like Coronavirus

Bat SARS-Iike coronavirus （SL-CoV） has a genome organization almost identical to that of SARS-CoV, but the N-terminus of the Spike （S） proteins, which interacts with host receptor and is a major target of neutralizing antibodies against CoVs, of the two viruses has only 63-64% sequence identity. Although there have been reports studying the overall immunogenicity of SsL, knowledge on the precise location of immunodominant determinants for SSL is still lacking. In this study, using a series of truncated expressed SsL fragments and SsL specific mouse sera, we identified two immunogenic determinants for SSL. Importantly, one of the two regions seems to be located in a region not shared by known immunogenic determinants of the SSARS. This finding will be of potential use in future monitoring of SL-CoV infection in bats and spillover animals and in development of more effective vaccine to cover broad protection against this new group of coronaviruses.

Primary squamous cell carcinoma of the liver associated with hepatolithiasis:A case report

Primary squamous cell carcinoma(SCC) of the liver is rare and reported sporadically.Up to date,only 24 such cases have been reported in the literature.It is associated with hepatic teratoma,congenital cysts,solitary benign non-parasitic hepatic cysts,hepatolithiasis/Caroli's disease or cirrhosis.We reported a case of primary SCC of the liver associated with multiple intrahepatic cholesterol gallstones.The patient underwent hepatectomy followed by radiotherapy,and has survived for over 19 mo without recurrence.

An Invariance Principle for ρ^--Mixing Random Sequences

In this paper,we establish an invariance principle for ρ^--mixing random sequences under some moment condition.The result improve and extend the relevant result of Wu（2003）.

Immunogenicity of the Spike Glycoprotein of Bat SARS-like Coronavirus

A group of SARS-like coronaviruses(SL-CoV)have been identified in horseshoe bats.Despite SL-CoVs and SARS-CoV share identical genome structure and high-level sequence similarity,SL-CoV does not bind to the same cellular receptor as for SARS-CoV and the N-terminus of the S proteins only share 64%amino acid identity,suggesting there are fundamental differences between these two groups of coronaviruses.To gain insight into the basis of this difference,we established a recombinant adenovirus system expressing the S protein from SL-CoV(rAd-Rp3-S)to investigate its immune characterization.Our results showed that immunized mice generated strong humoral immune responses against the SL-CoV S protein.Moreover,a strong cellular immune response demonstrated by elevated IFN-γand IL-6 levels was also observed in these mice.However,the induced antibody from these mice had weaker cross-reaction with the SARS-CoV S protein,and did not neutralize HIV pseudotyped with SARS-CoV S protein.These results demonstrated that the immunogenicity of the SL-CoV S protein is distinct from that of SARS-CoV,which may cause the immunological differences between human SARS-CoV and bat SL-CoV.Furthermore,the recombinant virus could serve as a potential vaccine candidate against bat SL-CoV infection.