中国煤中氟的含量及其分布

在全国主要产煤的 2 6个省、市和自治区根据各煤田的地质储量、成煤时期和煤变质程度 ,兼顾各矿区的煤炭产量 ,采集30 5个煤样 ,用高温热水解 离子选择性电极法测定了全部样品的氟含量 .煤中的氟主要以无机形态赋存 ,氟含量和变质程度之间没有必然的联系 .成煤时代等单一因素对氟含量的影响可能为其它各种因素的综合作用所掩盖 ,对此有必要进行更深入、具体的研究 .研究了各省、市和自治区的煤氟含量的分布 ,有必要重新审视、甄别燃煤型氟中毒区氟的来源 .全国煤的氟含量服从对数正态分布 ,90 %的样品含氟范围为 4 7～ 347mg/kg ,宜用几何平均值 136mg/kg作为全国平均煤氟含量 .与世界煤相比 ,中国煤氟含量并无异常 .

中国煤中氮的含量及其分布

为了解我国煤中氮的含量水平及其分布特征,在全国主要产煤的26个省、市、区,根据各煤田的地质储量、成煤时期和煤变质程度,兼顾各矿区的煤炭产量,采集306个煤样,测定了全部样品的氮含量,并对各成煤时代、各聚煤区、各省市区的煤氮含量进行了统计分析。研究表明:煤中氮主要以有机形态赋存;氮含量与煤变质程度间有微弱的正相关关系;全国煤的氮含量近似服从正态分布,90%的样品含氮范围为0.52%～1.41%,宜用算术平均值0.98%作为全国平均煤氮含量。

进食障碍检查自评问卷6.0中文版在女性进食障碍患者中应用的效度和信度

目的:检验进食障碍检查自评问卷6.0中文版(EDE-Q 6.0)测评女性进食障碍患者的适用性。方法:选取248名进食障碍患者和296名健康对照,使用验证性因素分析在患者中比较四因子结构、单因子结构和三因子结构;对两个样本均施测进食障碍调查量表(EDI)检验效标效度;使用两独立样本Mann-Whitney U检验比较EDE-Q 6.0在两样本上得分的差异以检验实证效度,并使用工作特征曲线ROC分析确定划界值;在两个样本中检验量表的内部一致性;1个月后,在患者中随机选取89名、对照中31名进行重测。结果:原始模型优于单因子模型和三因子模型;总样本、患者和对照的EDE-Q 6.0总分与EDI总分具有较高的一致性(ICC=0.88、0.87、0.73);患者的EDE-Q 6.0总分和各维度得分均高于对照(均P<0.01);EDE-Q 6.0受试者在ROC下的面积AUC=0.91,选取总分≥1.27作为EDE-Q 6.0的划界值,此时,敏感度为79.4%,特异度为88.2%。总样本、患者样本和对照样本的EDE-Q 6.0总量表的Cronbach α系数分别为0.95、0.91和0.88;总量表的重测信度为0.73,4个因子的重测信度分别为0.58、0.68、0.69和0.71。结论:进食障碍检查自评问卷6.0中文版在女性进食障碍患者中具有良好的心理测量属性,能够有效区分进食障碍患者与健康人群,同时能够准确评估临床症状的严重程度。

Highway bridge seismic design:summary of FHWA/MCEER project on seismic vulnerability of new highway construction

The Federal Highway Administration (FHWA) sponsored a large,multi-year project conducted by the Multidisciplinary Center for Earthquake Engineering Research (MCEER) titled'Seismic Vulnerability of New Highway Construction'(MCEER Project 112),which was completed in 1998.MCEER coordinated the work of many researchers,who performed studies on the seismic design and vulnerability analysis of highway bridges,tunnels,and retaining structures. Extensive research was conducted to provide revisions and improvements to current design and detailing approaches and national design specifications for highway bridges.The program included both analytical and experimental studies,and addressed seismic hazard exposure and ground motion input for the U.S.highway system;foundation design and soil behavior: structural importance,analysis,and response:structural design issues and details;and structural design criteria.

Identification and Characterization of Reduced Epicuticular Wax Mutants in Rice

Epicuticular wax forms the outermost protective barrier of the aerial surfaces of land plants, working in concert with other components of the plant cuticle to prevent uncontrolled loss of water and to provide protection against an array of external environmental stress. In this study, chemically- mutagenized populations of rice （Oryza sativa L.） derived from approximately 4 750 M2 families were screened for adhesion of water droplets resulting in a wet leaf/glossy （wig） phenotype. Mutants were identified in 11 independently-derived M2 families. Scanning electron microscopy analysis confirmed the association of the wig phenotype with changes in the epicuticular wax crystals of these plants. The phenotypes of five mutants （7-17A, 26.1, 524.2, 680.2, and 843.1） were confirmed to be the result of single recessive gene mutation. Evaluation of mutants from 3 （6-1A, 7-17A, and 11-39A） of 11 M2 families revealed significant reductions （〉 50%） in surface wax content and increases in cuticle membrane permeability.

Nitrogen in Chinese coals

Three hundred and six coal samples were taken from main coal mines of twenty-six provinces,autonomous regions,and municipalities in China,according to the resource distribution and coal-forming periods as well as the coal ranks and coal yields.Nitrogen was determined by using the Kjeldahl method at U.S.Geological Survey(USGS),which exhibit a normal frequency distribution.The nitrogen contents of over 90% Chinese coal vary from 0.52% to 1.41% and the average nitrogen content is recommended to be 0.98%.Nitrogen in coal exists primarily in organic form.There is a slight positive relationship between nitrogen content and coal ranking.

Finite element investigation of steel built-up shear links subjected to inelastic deformations

Non-linear finite element models accounting for large displacements have been used to investigate the behavior of steel built-up shear links that had previously been tested using large-scale experiments. The links were designed using steel grades with yield points ranging from high to low strengths. The objectives of the numerical analyses were to further investigate the non-linear behavior and to correlate the numerical results with experimental observations. Elasto-plastic as well as cyclic stress-strain material properties were incorporated to study the influence of material behavior on the overall shear link response. Non-linear monotonie analyses of the shear links incorporating the cyclic stress-strain steel properties resulted in similar trends in the response as the backbone curves recorded from the physical experiments. The numerical models of built-up shear links utilizing structural grade steels closely correlated to the experimentally recorded shear strength. Models utilizing low yield point steels overestimated the shear strength, which was caused by the characteristics of cyclic behavior of those steels. The detailed numerical models also allowed for investigation of the plastic strain demands on the different components of the link. It was shown that finite element models combined with appropriate stress-strain relationship may be used with confidence to check the design of shear links of different steel grades and sectional geometries.

South Carolina forestland owners’ willingness to accept compensations for carbon sequestration

Background: Carbon sequestration through recommended forest management practices is an ecosystem service that helps mitigate climate change and its impacts while generating carbon credits for forestland owners to sell in cap-and-trade programs. The California’s cap-and-trade program (California’s carbon market hereafter) allows forestland owners from any part of the contiguous United States to supply carbon credits to compliance entities. In this study, we estimate South Carolina (SC) private forestland owners’willingness to accept compensations to participate in the California’s carbon market using a contingent valuation method. Results: We estimate forestland owners’mean willingness to accept as$67 per acre per year. Our results reveal higher probability of participation of forestland owners with interests in preserving forest ecosystems than those who do not. Additionally, forestland owners who trust in information about climate change from scientists or government are willing to participate more than those who do not. Conclusions: Various factors hinder landowners’ability to participate in carbon markets. Forestland owners in SC consider legislative uncertainty and long-time commitment as the main barriers to participation in California’s carbon market. From this research, average forestland tenure in SC is 27 years, which is far less than the 100-year time commitment of the California’s carbon market. Of those who agreed to participate, choosing between adopting and not adopting any of the three main forest management practices in the California’s carbon market:28% are likely to adopt improved forest management (IFM) practices, 24% are likely to adopt reforestation due to understocked forestlands, and 14% are likely to adopt avoided conversion. In another development, the concept of aggregation has dominated discussions in the California’s carbon market of late. It is an advocacy to include small-scale forestlands in the California’s carbon market. To aggregate, different forestland owners will combine their forestlands to participate. We find that 79% of SC forestland owners are willing to aggregate to participate. However, this research is unable to determine how much total forestland is available in SC for carbon market. We recommend future research in the State on forestland owners’participation in carbon market should consider evaluating forestland availability.

RETHINKING ACCLIMATION OF GROWTH AND MAINTENANCE RESPIRATION OF TOMATO IN ELEVATED CO_2:EFFECTS OF A SUDDEN CHANGE IN LIGHT AT DIFFERENT TEMPERATURES

Aims Changes in light and temperature are among the most common and most profound environmental perturbations. The independent effects of light and temperature on photosynthesis and respiration are well studied in single leaves, but are less well studied in whole plants. The short and long term influence of light and temperature on carbon use efficiency is also poorly understood, and is commonly modeled to remain constant over a wide range of conditions. We sought to determine the primary effects of changing light at two growth temperatures on photosynthesis, respiration, and their balance, as defined by carbon use efficiency. Methods We separated respiration into growth and maintenance components using whole-canopy gas-exchange in an elevated CO2 environment in a controlled environment, and supplemented that information with tissue analysis. Important findings Decreases in light level decreased carbon use efficiency through a reduction in the maintenance coefficient, increased the growth coefficient, and reduced partitioning of N in protein. Growth temperature did not significantly affect either maintenance or growth respiration coefficients, suggesting that long-term temperature responses can differ greatly from short-term observations.

GTP环水解酶缺乏导致的常染色体显性遗传性Segawa综合征患者的扩展运动和精神病表型

Background: Segawa syndrome due to GTP cyclohydrolase deficiency is an autosomal dominant disorder with variable expression, that is clinically characterised by L-dopa responsive, diurnally fluctuating dystonia and parkinsonian symptoms. Objective: To delineate the neurological and psychiatric phenotype in all affected individuals of three extended families. Methods: GTP cyclohydrolase deficiency was documented by biochemical analyses, enzymatic measurements in fibroblasts, and molecular investigations. All affected individuals were examined neurologically, and psychiatric data were systematically reviewed. Results: Eighteen affected patients from three families with proven GTP cyclohydrolase deficiency were identified. Eight patients presenting at less than 20 years of age had typical motor symptoms of dystonia with diurnal variation. Five family members had late-presenting mild dopa-responsive symptoms of rigidity, frequent falls, and tendonitis. Among mutation carriers older than 20 years of age, major depressive disorder, often recurrent, and obsessive-compulsive disorder were strikingly more frequent than observed in the general population. Patients responded well to medication increasing serotonergic neurotransmission and to L-dopa substitution. Sleep disorders including difficulty in sleep onset and maintenance, excessive sleepiness, and frequent disturbing nightmares were present in 55% of patients. Conclusion: Physicians should be aware of this expanded phenotype in affected members of families with GTP cyclohydrolase deficiency.

非体外循环与体外循环下冠状动脉搭桥术后5年认知功能和心脏结局的比较

背景:采用体外循环的常规冠状动脉搭桥术(CABG)具有良好的长期心脏结局,但认知功能减退的发生率较高。非体外循环下的CABG对长期心脏结局和认知功能的影响尚不清楚。目的:比较非体外循环和体外循环下CABG对长期认知功能和心脏结局的影响。设计、机构和参与者:Octopus研究是在荷兰进行的一项多中心、随机对照试验,于1998—2000年间共纳入281例低风险CABG患者。

脂肿性秃发:盘状狼疮的一种少见后遗症或其他疾病引起?

Background: Lipedematous alopecia is a rare entity of uncertain origin characterized by a boggy scalp and varying alopecia. Of 11 cases in the literature, 7 occurred in African American women. Classic histopathologic findings include increased subcutaneous tissue, varying inflammation, and an absence of mucin. Some have sought to distinguish this disorder from lipedematous scalp, a condition with similar tactile features, but without alopecia. Observation: We describe a case of lipedematous alopecia in an African American woman who also had findings of discoid lupus erythematosus. Such an observation has not been made previously, and may provide insight into the cause of lipedematous alopecia. This case is contrasted with a case of lipedematous scalp. Conclusion: Some cases of lipedematous alopecia may represent an unusual consequence of discoid lupus erythematosus. Alternatively, it is possible that lipedematous scalp is a benign condition observed in some patients, and that a second insult results in alopecia. Finally, lipedematous alopeciamight share some histopathologic and/or clinical findings with discoid lupus erythematosus, or it may represent a nonspecific reaction pattern to chronic injury.

Explaining patterns of species dominance in the shrub steppe systems of the Junggar Basin(China) and Great Basin(USA)

Natural scientists have long recognized that regions with similar climate tend to have similar vegetation.Preliminary observations suggest that shrub steppe communities of the western US and western China may be two such regions with similar annual precipitation,temperature,land use,and vegetation.These cold dry shrub steppes have traditionally been grazed.Despite these similarities,patterns of species dominance are different.Annual species that are rare in China become dominant when introduced to the United States.The objective of this study was to investigate how climate,land use and community structure may explain these patterns of species dominance.Community structure and grazing intensity were measured at 5 sites in each region.This information was combined with a broader review of the literature describing the history of grazing in both basins.Climate was analyzed based on a spatially-gridded,interpolated weather time series （monthly records） and climatological summary （1961-1990 mean conditions） data set from the Climate Research Unit.We found that differences in summer precipitation and winter minimum temperature,land use intensity,and shrub size may all contribute to the dominance of annual species in the Great Basin,particularly Bromus tectorum.In particular,previous work indicates that summer precipitation and winter temperature drive the distribution of Bromus tectorum in the Great Basin.As a result,sites with wet summers and cold springs,similar to the Chinese sites,would not be expected to be dominated by Bromus tectorum.A history of more intense grazing of the Chinese sites,as described in the literature,also is likely to decrease fire frequency,and decreases litter and shrub dominance,all of which have been demonstrated to be important in Bromus tectorum establishment and ultimate dominance.Further research is necessary to determine if other annuals that follow the same pattern of scarcity in the Junggar Basin and dominance in the Great Basin are responding to the same influences.

Regional Analysis of NASA Satellite Greenness Trends for Ecosystems of Arctic Alaska

Trends in the growing season MODerate resolution Imaging Spectroradiometer (MODIS) Enhanced Vegetation Index (EVI) time-series were analyzed for the period from 2000 to 2010 to understand landscape-level patterns of vegetation change in ecosystems of arctic Alaska. We compared datasets for vegetation cover types, wetland cover classes, wildfire boundaries since the 1940s, permafrost type, and elevation to identify the most likely combination of factors driving regional changes in habitat quality and ecosystem productivity. Approximately 57% of all arctic ecosystem areas in Alaska were detected with significant (p < 0.05) positive or negative MODIS growing season EVI trends from 2000 to 2010. Nearly all (99%) of these ecosystem areas (covering 178,050 km2) were detected with significant positive growing season EVI trends. The vast majority of the arctic Alaska region detected with significant positive growing season EVI trends was classified as upland tundra cover, although non-forested wetlands (marshes, bogs, fens, and floodplains) were co-located on 8% of that area. Herbaceous wetlands were co-located on 55% of the total area detected with significant negative growing season EVI trends, mostly on the arctic coastal plain and foothills. This evidence supports the hypothesis that temperature (warming) has markedly enhanced the rates of upland tundra vegetation growth across most of arctic Alaska over recent years.

Synthesis and photoelectrical performance of nanoscale PbS and Bi2S3 co-sensitized on TiO2 nanotube arrays

TiO2 films have been widely applied in photo- voltaic conversion techniques. TiO2 nanotube arrays （TiO2 NAs） can be grown directly on the surface of metal Ti by the anodic oxidation method. Bi2S3 and PbS nanoparticles （NPs） were firstly co-sensitized on TiOa NAs （denoted as PbS/Bi2S3（n）/TiO2 NAs） by a two-step process containing hydrothermal and sonication-assisted SILAR method. When the concentration of Bi3＋ is 5 mmol/L, the best photoelectrical performance was obtained under simulated solar irradiation. The short-circuit photocurrent （Jsc） and photoconversion efficiency （η） of PbS/Bi2S3（5）/TiO2 NAs electrode were 4.70 mA/cm and 1.13 %, respectively.

基于人群的BMI百分位数和腰围/身高比对识别青少年心血管疾病风险作用之比较

Objective: Determine whether waist- to- height ratio (WHtR) or sex- and ag e- specific percentiles of body mass index (BMI)- better identifies cardiovasc ular risk. Study design: The third National Health and Nutrition Examination Sur vey (NHANES III) provided measurements on 7657 participants statistically weight ed to represent 50.05 million youth 4 to 17 years of age. We estimated the subpo pulations corresponding to BMI strata that were normal ( < 85th percentile), at risk for overweight (85th to < 95th percentile), and overweight (≥ 95th percent ile). We chose WHtR cutoff points (0.490 and 0.539) so that subpopulation sizes in the three WHtR strata would equal those in the three BMI strata. For 13 cardi ovascular risk factors we compared mean levels among youth discordant for their BMI and WHtR strata. Results: 726 participants (representing 3.69 million youth) were identified as having WHtR stratum > BMI stratum. Compared with the 603 par ticipants (representing 3.70 million youth) who were discordant in the opposite direction, weighted analyses showed they had higher mean levels of heart rate, l ow- density lipoprotein (LDL) cholesterol, fasting triglycerides, and total cho lesterol (P < .015, adjusted for sex, age, and race- ethnicity). Their mean sys tolic blood pressure was lower, but this difference was eliminated after adjustm ent for their shorter stature. Conclusion: WHtR, a simpler anthropometric index than sex- and age- specific BMI percentiles, better identi- fies youth with a dverse cardiovascular risk factors.

布洛芬敏感性小儿哮喘的发病率:一项随机对照气管刺激试验研究

Objective: To determine the prevalence of ibuprofen-sensitive asthma in schoo l-aged children with mild ormoderate persistent asthma. Study design: A randomi zed, double-blind, placebocontrolled, crossover bronchoprovocation challenge st udy in children 6 to 18 years of age with mild or moderate persistent asthma. Pa tients received a single dose of ibuprofen or placebo, per randomization, and th en returned 2 to 7 days later to repeat the procedures after taking that study d rug not received at the first visit. At each visit, patients performed spirometr y before and 1/2, 1, 2, and 4 hours after administration of study drug. We defin ed bronchospasm as a ≥20%decrease from baseline in the forced expired volume i n the first second (FEV1) and ibuprofen sensitivity as bronchospasm following ad ministration of ibuprofen but not placebo. Results: Of the 127 patients screened , 100 (mean age, 11 years) completed the study. Two patients met criteria for ib uprofen-sensitive asthma, resulting in a prevalence of 2%(95%CI: 0.2%-7%). Neither patient was known to have had any exposure to ibuprofen before the stud y. Conclusion: The prevalence of ibuprofen-sensitive asthma was low but non-ze ro in this group of children with mild or moderate asthma. The possibility of ib uprofen-induced bronchospasm should be considered before administering ibuprofen to children with asthma.

比较亮脯利特与醋酸甲孕酮注射剂皮下注射治疗子宫内膜异位症相关疼痛

Objective: To compare the efficacy and safety of SC depot medroxyprogesterone acetate (DMPA- SC 104) with that of leuprolide acetate in treatment of endometriosis. Design: Phase 3, multicenter, randomized, evaluator- blinded, comparator- controlled trial. Setting: Clinical trial sites in Canada and United States. Patient(s): Two hundred seventy- four women with surgically diagnosed endometriosis. Intervention(s): Intramuscular injections of DMPA- SC (104 mg) or leuprolide acetate (11.25 mg), given every 3 months for 6 months, with 12 months of posttreatment follow- up. Main Outcome Measure(s): Reduction in five endometriosis symptoms or signs (dysmenorrhea, dyspareunia, pelvic pain, pelvic tenderness, pelvic induration); change in bone mineral density (BMD), hypoestrogenic symptoms, bleeding, and weight. Result(s): The depot medroxyprogesterone acetate given SC was statistically equivalent to leuprolide in reducing four of five endometriosis symptoms or signs at the end of treatment (month 6) and in reducing all five symptoms after 12 months’ follow- up (month 18). Patients in the DMPA- SC 104 group showed significantly less BMD loss than did leuprolide patients at month 6, with scores returning to baseline at 12 months’ follow- up. No statistically significant differences in median weight changes were observed between groups. Compared with leuprolide, DMPASC 104 was associated with fewer hypoestrogenic symptoms but more irregular bleeding. Conclusion(s): Efficacy of DMPASC 104 was equivalent to that of leuprolide for reducing endometriosis- associated pain, with less impact on BMD and fewer hypoestrogenic side effects but more bleeding.