掺镧钛酸钡陶瓷晶界的再氧化

掺La的BaTiO3陶瓷在H2和Ar(体积比1:99)的还原气氛下烧结后,在氧分压p(O2)=260 Pa的气氛(Ar和O2的混合气体)下进行氧化,测量了吸氧量不同时的复阻抗图谱,研究了再氧化过程中晶粒和晶界的吸附氧对电阻率的影响.结果表明:在还原气氛下烧结可以扩展有效施主掺杂浓度的范围,通过晶粒的异常生长,制备出高施主掺杂量(10%,摩尔分数)的半导性BaTiO3陶瓷.再氧化过程中,随氧化温度的升高(1 017～1 380℃),晶界吸附氧的量增大,晶界处的晶界势垒包括两部分:外部晶界吸收氧原子充当表面受主态;内部晶界在氧化过程中被氧化形成正离子空位(Ti空位)充当受主态,从而提高了受主态密度,导致样品的正温度系数电阻效应增强.

Ba_(1-x)La_xTiO_3陶瓷的晶界再氧化机理研究

不同La施主掺杂浓度的BaTiO3陶瓷在H2／Ar的还原气氛下烧结后,再在氧分压Po2=260Pa的气氛(Ar和O2的混合气体)下进行氧化,通过氧流量计检测还原样品在再氧化过程的吸氧行为;用TEM分析样品氧化后显微结构的变化,测定了在不同最高氧化温度下氧化样品的PTCR效应以及复阻抗图谱．结果表明:氧流量计在升温阶段检测到三个不同行为的吸氧峰,峰I(起始温度-250℃)为氧空位的填充过程;峰II(起始温度-800℃)和峰III(起始温度-1250℃)为还原相的氧化过程,具体来说,峰II是通过晶界扩散提供氧使靠近晶界附近的区域被氧化;而峰III是由晶格扩散过程控制,氧化过程从晶界逐渐向晶粒内部区域扩展,并伴随着富Ti的Ba6Ti17O40相的沉淀．在还原相向氧化相的转变过程中,于晶界处形成了两个具有晶界势垒的电结构单元而使陶瓷呈现强PTCR效应．

CD82介导的人类甲状腺癌细胞株FTC-133的生物学特性

目的:探讨肿瘤转移抑制因子CD82在调控人甲状腺癌细胞侵润和迁移中的作用以及发挥作用的相关分子机制。方法:采用基因工程技术,将含CD82全长基因的p CDNA3.1质粒用于细胞转染,构建过表达CD82基因的FTC-133细胞株,并将其与野型FTC-133细胞株进行生物性状比对。利用MTT法及Transwell细胞迁移实验检测CD82对FTC-133细胞侵润和迁移能力的影响。结果:与野生型或者空质粒转染细胞相比,各转染细胞(clone 1、2、3)在转染后24、48及72 h的增殖率减少(P>0.05);与野生型或者空质粒转染细胞相比,各转染细胞(clone 1、2、3)在转染后24、48及72 h的迁移能力明显减少(P<0.05)。结论:CD82可以明显降低FTC-133细胞的增殖及侵袭能力,与甲状腺癌发展与进程密切相关。

Risk of second primary cancers after testicular cancer in East and West Germany： a focus on contralateral testicular cancers

Testicular cancer survival rates improved dramatically after cisplatin-based therapy was introduced in the 1970s. However, chemotherapy and radiation therapy are potentially carcinogenic. The purpose of this study was to estimate the risk of developing second primary cancers including the risk associated with primary histologic type （seminoma and non-seminoma） among testicular cancer survivors in Germany. We identified 16 990 and 1401 cases of testicular cancer in population-based cancer registries of East Germany （1961-1989 and 1996-2008） and Saarland （a federal state in West Germany; 1970-2008）, respectively. We estimated the risk of a second primary cancer using standardized incidence ratios （SIRs） with 95% confidence intervals （95% Cls）. To determine trends, we plotted model-based estimated annual SIRs. In East Germany, a total of 301 second primary cancers of any location were observed between 1961 and 1989 （SIR： 1.9; 95% Ch 1.7-2.1）, and 159 cancers （any location） were observed between 1996 and 2008 （SIR： 1.7; 95% Ch 1.4-2.0）. The SIRs for contralateral testicular cancer were increased in the registries with a range from 6.0 in Saarland to 13.9 in East Germany. The SIR for seminoma, in particular, was higher in East Germany compared to the other registries. We observed constant trends in the model-based SIRs for contralateral testicular cancers. The majority of reported SIRs of other cancer sites including histology-specific risks showed low precisions of estimated effects, likely due to small sample sizes. Testicular cancer patients are at increased risk especially for cancers of the contralateral testis and should receive intensive follow-ups.

Advances in studies on the physiological and molecular regulation of barley tillering

Tillering is a crucial trait closely associated with yield potential and environmental adaptation in cereal crops,regulated by the synergy of endogenous(genetic)and exogenous(environmental)factors.The physiological and molecular regulation of tillering has been intensively studied in rice and wheat.However,tillering research on barley is scarce.This review used the recent advances in bioinformatics to map all known and potential barley tiller development genes with their chromosomal genetic and physical positions.Many of them were mapped for the first time.We also discussed tillering regulation at genetic,physiological,and environmental levels.Moreover,we established a novel link between the genetic control of phytohormones and sugars with tillering.We provided evidence of how environmental cues and cropping systems help optimize the tiller number.This comprehensive review enhances the understanding of barley’s physiological and genetic mechanisms controlling tillering and other developmental traits.

Association of late-life changes in blood pressure and cognitive status

BackgroundDisagreement exists on the association between changes in blood pressure and cognitive impairment. We aimed to ex-amine whether 4-year changes in systolic and diastolic blood pressure （SBP and DBP） are associated with cognitive status in a representative sample of older men and women.MethodsAnalysis of longitudinal data from 854 participants of a population-based German sample （aged 60-87 years） was performed with standard cognitive screening and blood pressure measurements. Effects of changes in SBP and DBP （10 mmHg and 5 mmHg respectively as unit of regression effect measure） on cognitive status were evaluated using non-parametric and lin-ear regression modeling.ResultsNo clear associations were seen between changes in SBP or in DBP and cognitive scores. Small effects were found after stratification for sex and hypertension awareness. Specifically, larger decreases in SBP were associated with higher cogni-tive scores in those men aware of their hypertension （10 mmHg decrease in SBP,b =-0.26, 95% CI：-0.51 to-0.02） and men with con-trolled hypertension （10 mmHg decrease in SBP,b =-0.44, 95% CI：-0.92 to-0.03）. Additionally larger increases in DBP were associated with higher cognitive scores in men with controlled hypertension （5 mmHg increase in DBP,b = 0.67, 95% CI： 0.19-1.15）. For women aware of their hypertension, larger decreases in DBP were associated with higher cognitive scores （5 mmHg decrease in DBP,b =-0.26; 95%CI：-0.51 to-0.01）.ConclusionsChanges in blood pressure were only weakly associated with cognitive status. Specifically, decreases in SBP were associated with higher cognitive scores in men aware of their hypertension and especially those that were medically controlled.

Acute Inferior Myocardial Infarction Presenting as Anterior ST Segment Elevation Myocardial Infarction on ECG

A 51-year-old man presented to the emergency department with acute substernal chest pain. ECG showed ST-segment elevation in the left precordial leads. Coronary angiography demonstrated an occlusion of the right coronary artery (RCA) and no significant stenosis in left anterior descending coronary artery (LAD). The occlusion of a non-dominant RCA may result in anterior ST-segment elevation ECG changes, which could disorient both general and interventional cardiologists.

情景图片驱动的数学团队合作学习

一、想象一下有这样一个情境 在很多人心里，“做数学意味着计算”．没错，但这肯定不是数学的全部．因为数学比“仅仅是计算”要多得多．在这篇文章里，我们将呈现给大家一些我们已经成功应用于德国初中数学竞赛中的不同寻常的开放性问题．参加竞赛的所有学生要在一周内解决同样的问题并将他们的解决方案包括对求解过程的描述提交上来．

长爪沙鼠家庭内的攻击行为可调整其生理特征(英文)

长爪沙鼠家庭动态变化所导致的社群压力是一个很少被描述的现象。本研究测定了72只长爪沙鼠的一些生理参数,包括器官重(肝脏、肾脏和脾脏)和血液的生化指标(胆固醇、甘油三酯、葡萄糖和丙氨酸转氨酶)。此外,对家庭内攻击过程中动物的全血细胞数变化也进行了检测。以家庭为单位,所有动物被置于半圈养的实验室条件下,自由取食和饮水。家庭内被攻击的雄性个体的腹下腺显著减小(Mann-WhitneyU-TestU=48.0,P=0.04)。以绝对体重和去脂体重校正后,受到攻击个体的肝脏重量也显著高于未受攻击的个体(肝脏绝对重量Mann-WhitneyU-TestU=169,P=0.02;肝脏相对重量即占去脂体重的百分比U=166,P=0.02),但肾脏重量则显著低于未受攻击的个体(绝对肾脏重量Mann-WhitneyU-TestU=183.5,P=0.04;相对肾脏重量U=137,P=0.005)。被攻击个体的白细胞(U=11.0,P=0.02)和血小板(U=6.0,P=0.004)都显著增加。同时也发现分解作用产生的代谢物有所不同。被攻击的个体具有较高的胆固醇含量(U=13.5,P=0.005)和较低的丙氨酸转氨酶含量(U=13.0,P=0.006)。结果表明家庭内的攻击行为是直接针对那些地位较低的成员,导致其能量物质的释放增加,同时激活了免疫系统以应对由于攻击导致的身体损伤的增加。

The Role of Attitude Strength in Predicting Organ Donation Behaviour by Implicit and Explicit Attitude Measures

Explicit attitude measures seem to be rather poor predictors of organ donation behaviour. This study examined whether implicit attitude measures acted as better predictors. Special attention was paid to the moderating role played by attitude strength in predicting deliberate donation behaviour. In this study (N = 78), explicit and implicit measures of attitudes towards organ donation, as well as behavioural commitment, were assessed. Implicit associations were measured by an Implicit Association Test;five constructs assessed self-reported—understood as reflected—attitude strength. The explicit attitude measure appeared to be the best single predictor of whether the participant ended up taking an organ donor card. More importantly, test results demonstrated the moderating role of attitude strength. In the case of low attitude strength, the likelihood of taking a donor card increased with an increasing positive implicit association. In contrast, increasing strength was associated with a weaker link between card taking and the implicit attitude measure. The results are discussed in light of the power of implicit associations to predict more deliberate behaviours.

Hydrothermal Dissolution of Opal in Sodium Hydroxide Lyes for the Synthesis of Water Glass

Common opal was dissolved in NaOH lyes in rotating autoclaves. The starting material was characterized by X-ray diffraction and adsorption spectroscopy, thermal and chemical analysis, electron and atomic force microscopy. The opal proved to be an Opal-CT with a microstructure consisting of microcrystalline tridymite, traces of low-quartz, and amorphous parts built up by random packings of size distributed amorphous silica colloids. The dissolution conditions have been inspired by the technological process of hydrothermal water glass synthesis by dissolving silica. Temperature and time of the dissolution process as well as initial molar SiO2:Na2O (Rm) ratios of the starting materials were varied systematically. The particle size of the samples was varied, too, but due to the nanoscopic microstructure without greater impact on dissolution kinetics. The process products were analyzed chemically. Additionally, some of them were characterized by X-ray diffraction, viscosimetry and dynamic light scattering. Already after short dissolution times, water glasses with quite high silica concentrations of up to 27 wt.% and SiO2:Na2O ratios of up to 3.7 were obtained. At longer dissolution times low-quartz and analcime precipitated and the SiO2 contents were reduced to about 22 wt.% and Rm to about 2.7. The silica contents in equilibrium with low-quartz were almost independent on temperature.

Daily Physical Activity Improves Vascular Function and Motor Skills in Children

The literature is consistent that regular physical activity in children has to be increased in order to compensate the negative health effects resulting from growing sedentary lifestyle. Thus, we analyzed in 45 students （aged 6.6 ± 0.7 years） the effects of a regular exercise intervention, on top of the normal physical education classes, on motor performance （MP） and hemodynamic parameters. The students were randomized either to an intervention （INT） （n = 23） or a control （CON） （n = 22） group. Throughout a 9 months period, INT received additional exercise interventions two days a week for 45 minutes. The main outcome measures were MP, peripheral and central blood pressure （BP）, augmentation index （Alx） and aortic pulse wave velocity （aPWV）. After the exercise intervention, we found significant （P 〈 0.05） positive effects on various test items of MP and significant decreases in peripheral and central systolic BP in INT. In contrast, in CON the respective parameters increased in CON alter the observation period. Moreover, aPWV decreased significantly in INT （P = 0.047） and increased in CON, thus resulting in a significant difference in the mean change （P = 0.043）. There were no considerable changes in AIx in both groups. In conclusion, we demonstrated that an increase in regular physical activity has a positive influence on development of MP and hemodynamic parameters even in early childhood. The findings of this study suggest that an increase in exercise time should be initiated as early as possible to improve motor ability and prevent future cardiovascular risk.

Cataractogenesis-Light光学显微镜与Scheimpflug密度分析白内障和糖尿病、非糖尿病透明晶状体的晶状体上皮改变

Background:We compared the human lens documented,using the Scheimpflug densitometry,with the light microscopic changes in the epithelium of the anterior central lens in patients with age-related cataract and diabetes mellitus type II and verified the findings on the control tissue of the clear eye lens.We wanted to determine the relevance of the lens epithelium in cataract formation in type II diabetics compared to non-diabetics.Materials and methods:One hundred fifty central lens capsules(138 cataract and 12 clear lenses)of type II diabetics(n=77,45 female,32 male)and non-diabetics(n=73,41 female,32 male)were examined by light microscope,regarding defined histomorphological parameters.Further criteria were duration of diabetes,diabetic retinopathy,cataract(PENTACAM,scheimpflug densitometric definition),protein content in the aqueous humour(laser flare meter 500 KOWA,tyndallometry),different blood parameters and glucose content in the aqueous humour.Results:The mean cell density in the cataractous lens in type II diabetics was 3,951± 528 cells/mm2 and in nondiabetics 4,329± 580 cells/mm2(P< 0.001);in the clear lens it corresponded to 4,593± 409 cells/mm2(type II diabetics)and 4,894± 333 cells/mm2(non-diabetics,P=0.207).The cell density of the cataractous lens in type II diabetics(P=0.005)and in non-diabetics(P=0.035)is smaller than that of the clear lens.The cell area of the lens epithelium in the cataractous diabetic lens is larger(P< 0.001)and the nucleus-plasma ratio is lower(P< 0.001)than those of the clear non-diabetic lens.The increase in damage of the lens epithelium correlates with the decrease of cell density(P< 0.001),the increase of nucleus area and volume(P< 0.001),and the decrease of nucleus-plasma ratio(P< 0.001).Risk factors for the decrease of cell density are advanced age(P=0.015),type II diabetes(P=0.01),increase in glucose content in the aqueous humour(P=0.014),increase in blood sugar(P=0.003)and increase in glycosylated haemoglobin(P=0.039).Conclusions:The lens epithelium is primarily damaged in type II diabetics who develop age-related cataract.This might play an important role in cataract formation.

Soil respiration is driven by fine root biomass along a forest chronosequence in subtropical China

Aims Soil respiration(Rs)is a major process controlling soil carbon loss in forest ecosystems.However,the underlying mechanisms leading to variation in Rs along forest successional gradients are not well understood.In this study,we investigated the effects of biotic and abiotic factors on Rs along a forest successional gradient in southeast China.Methods We selected 16 plots stratified by forest age,ranging from 20 to 120 years.In each plot,six shallow collars and six deep collars were permanently inserted into the soil.Shallow and deep collars were used to measure Rs and heterotrophic respiration(Rh),respectively.Autotrophic soil respiration(Ra)was estimated as the difference between Rs and Rh.Litter layer respiration(R_(L))was calculated by subtracting soil respiration measured in collars without leaf litter layer(R_(NL))from Rs.Rs was measured every 2 months,and soil temperature(ST)and soil volumetric water content(SVWC)were recorded every hour for 19 months.We calculated daily Rs using an exponential model dependent on ST.Daily Rs was summed to obtain cumulative annual Rs estimates.Structural equation modelling(SEM)was applied to identify the drivers of Rs during forest succession.Important Findings Rs showed significant differences among three successive stages,and it was the highest in the young stage.Ra was higher in the young stage than in the medium stage.Cumulative annual Rs and Ra peaked in the young and old stages,respectively.Cumulative annual Rh and respiration measured from soil organic matter(R_(SOM))decreased,whereas R_(L)increased with forest age.The SEM revealed that cumulative annual Rs was influenced by fine root biomass and SVWC.Our results indicated that the dominant force regulating Rs on a seasonal scale is ST;however,on a successional scale,belowground carbon emerges as the dominant influential factor.

Shifts in community leaf functional traits are related to litter decomposition along a secondary forest succession series in subtropical China

Aims We investigated shifts in community-weighted mean traits(CWm)of 14 leaf functional traits along a secondary successional series in an evergreen broadleaf forest in subtropical southeast China.most of the investigated traits have been reported to affect litter decomposition in previous studies.We asked whether changes in CWms along secondary succession followed similar patterns for all investigated traits and whether the shifts in CWm indicated a change in resource use strategy along the successional gradient.using community decomposition rates(k-rates)estimated from annual lit-ter production and standing litter biomass,we asked whether the dynamics of litter decomposition were related to changes in leaf functional traits along the successional series.Methods twenty-seven plots were examined for shifts in leaf CWm traits as well as in k-rates along a series of secondary forest succession cov-ered in the framework of the bEF-China project.We investigated whether the changes in CWms followed similar patterns for all traits with ongoing succession.three alternative linear models were used to reveal the general patterns of shifts in CWm trait values.moreover,multiple regression analysis was applied to investigate whether there were causal relationships between the changes in leaf functional traits and the dynamics of litter decomposition along secondary succession.We furthermore assessed which traits had the highest impact on community litter decomposition.Important Findingsshifts in CWm values generally followed logarithmic patterns for all investigated traits,whereas community k-rates remained stable along the successional gradient.In summary,the shifts in CWm values indicate a change in community resource use strategy from high nutrient acquisition to nutrient retention with ongoing succession.stands with higher CWm values of traits related to nutrient acquisition had also higher CWm values of traits related to chemical resistance,whereas stands with higher CWm values of traits related to nutrient retention exhibited higher CWm values in leaf physical defense.moreover,high values in CWm values related to nutritional quality(such as high leaf phosphorus concentrations)were found to promote com-munity k-rates,whereas high values in physical or chemical defense traits(such as high contents in polyphenols or high leaf toughness)decreased litter decomposition rates.In consequence,litter decom-position,which was simultaneously affected by these characteristics,did not change significantly along succession.our findings show that leaf decomposition within the investigated communities is dependent on the interplay of several traits and is a result from interactions of traits that affect decomposition in opposing directions.

Multiple common garden experiments suggest lack of local adaptation in an invasive ornamental plant

Adaptive evolution along geographic gradients of climatic conditions is suggested to facilitate the spread of invasive plant species,leading to clinal variation among populations in the introduced range.We investigated whether adaptation to climate is also involved in the invasive spread of an ornamental shrub,Buddleja davidii,across western and central Europe.Methods We combined a common garden experiment,replicated in three climatically different central European regions,with reciprocal transplantation to quantify genetic differentiation in growth and reproductive traits of 20 invasive B.davidii populations.Additionally,we compared compensatory regrowth among populations after clipping of stems to simulate mechanical damage.Important Findings Our results do not provide evidence for clinal variation among invasive B.davidii populations:populations responded similarly to the different environments,and trait values were not correlated to climatic conditions or geographic coordinates of their home sites.Moreover,we did not detect differences in the compensatory ability of populations.We suppose that the invasive spread of B.davidii has been facilitated by phenotypic plasticity rather than by adaptation to climate and that continent-wide shuffling of cultivars due to horticultural trade may have limited local adaptation so far.

Genomic analyses of metal resistance genes in three plant growth promoting bacteria of legume plants in Northwest mine tailings, China

To better understand the diversity of metal resistance genetic determinant from microbes that survived at metal tailings in northwest of China, a highly elevated level of heavy metal containing region, genomic analyses was conducted using genome sequence of three native metal-resistant plant growth promoting bacteria（PGPB）. It shows that： Mesorhizobium amorphae CCNWGS0123 contains metal transporters from P-type ATPase, CDF（Cation Diffusion Facilitator）, Hup E/Ure J and CHR（chromate ion transporter） family involved in copper, zinc, nickel as well as chromate resistance and homeostasis. Meanwhile, the putative Cop A/Cue O system is expected to mediate copper resistance in Sinorhizobium meliloti CCNWSX0020 while Znt A transporter, assisted with putative Czc D, determines zinc tolerance in Agrobacterium tumefaciens CCNWGS0286. The greenhouse experiment provides the consistent evidence of the plant growth promoting effects of these microbes on their hosts by nitrogen fixation and/or indoleacetic acid（IAA） secretion,indicating a potential in-site phytoremediation usage in the mining tailing regions of China.

The Chloroplast Import Receptor Toc90 Partially Restores the Accumulation of Toc159 Client Proteins in the Arabidopsis thaliana ppi2 Mutant

Successful import of hundreds of nucleus-encoded proteins is essential for chloroplast biogenesis. The import of cytosolic precursor proteins relies on the Toc- （translocon at the outer chloroplast membrane） and Tic- （translocon at the inner chloroplast membrane） complexes. In Arabidopsis thaliana, precursor recognition is mainly mediated by outer membrane receptors belonging to two gene families： Toc34/33 and Toc159/132/120/90. The role in import and precursor selectivity of these receptors has been intensively studied, but the function of Toc90 still remains unclear. Here, we report the ability of Toc90 to support the import of Toc159 client proteins. We show that the overexpression of Toc90 partially complements the albino knockout of Toc159 and restores photoautotrophic growth. Several lines of evidence including proteome profiling demonstrate the import and accumulation of proteins essential for chloroplast biogenesis and functionality.

The Secret Life of Chloroplast Precursor Proteins in the Cytosol

Eukaryotic cells contain semi-autonomous organelles that have lost most of their coding capacity for essential proteins to the nucleus.Therefore,their functioning depends on the cytosolic translation products of nuclear-encoded genes that must be imported by a specialized protein import machinery.Chloroplasts import between 2500 and 3500 proteins for their functioning,demonstrating that the bulk of the chloroplast proteome is shuttied through the cytosol as precursor proteins.Precursor proteins usually contain an N-terminal transit peptide that is cleaved off by a signa/processing peptidase(SPP)and degraded by the chloroplast protease network upon import.In the cytosol,precursors can be co-and post-translationally modified,interact with a set of chaperones,co-chaperones,14-3-3 proteins,and/or E3 ligases before they are either imported or degraded by the cytosolic proteasome complex.It is now clear that precursors are not only a transient transport form of functional proteins but that their cytosolic transition is of regulatory importance.

Cherish your weeds

The domestication of crops was a protracted process that extended over thousands of years.It began approximately 12000 years ago and marked the onset of the Neolithic Age.During the Neolithic,human cultures transitioned from a hunter-gatherer lifestyle toward one of agriculture and settlement.This process,however,was a long one,which spanned many human generations.During this period,many of today's most important crops were domesticated from wild relatives.Examples include wheat,barley,rice,and maize.