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51.
摘要 目的:分析血清载脂蛋白C1(APOC1)、乳酸脱氢酶(LDH)及炎性感染指标在难治性支原体肺炎患儿中的表达水平及其与肺通气功能、预后效果的相关性。方法:选择我院自2019年1月至2022年12月接诊的130例难治性支原体肺炎患儿作为观察组,另选同期在我院体检且结果正常的儿童作为对照组。检测两组入选者血清APOC1、LDH及炎性感染指标[C反应蛋白(CRP)、白细胞介素-6(IL-6)]表达水平、肺通气功能指标[用力肺活量(FVC)、第1秒用力呼气容积(FEV1)、呼气峰流速(PEF)];观察组患儿均严格按照《儿童社区获得性肺炎诊疗规范(2019年版)》接受治疗,通过ROC曲线下面积(AUC)评价血清APOC1、LDH及炎性感染指标对难治性支原体肺炎患儿预后不良的预测效能。结果:观察组血清APOC1、LDH、CRP、IL-6表达水平均高于对照组(P<0.05);在观察组患儿中,重症组血清APOC1、LDH、CRP、IL-6表达水平均高于轻症组(P<0.05);经Pearson相关性分析,难治性支原体肺炎患儿血清APOC1、LDH、CRP、IL-6表达水平均与FVC、FEV1、PEF呈负相关(P<0.05);经多因素Logistic回归分析,难治性支原体肺炎患儿血清APOC1、LDH、CRP、IL-6均是其预后不良的独立预测因素(P<0.05);经ROC曲线分析,难治性支原体肺炎患儿血清APOC1、LDH、CRP联合IL-6预测其预后不良的AUC为0.930。结论:血清APOC1、LDH及炎性感染指标在难治性支原体肺炎患儿中的表达水平明显升高,与其肺通气功能密切相关,其中APOC1、LDH、CRP联合IL-6预测预后不良的效能较好,值得进一步研究应用。  相似文献   
52.
The first experiments to clearly demonstrate that DNA techniques might be used to detect predator-prey interactions between arthropods are reported. The accurate modelling of such interactions has depended until now upon a mixture of laboratory experiments, population monitoring and biochemical tests. The latter involve gut-content analyses, and have most recently depended upon the development of prey-specific monoclonal antibodies. Although these are excellent for detecting predation on a target prey, they are impractical for analysing the prey range of a particular predator. Molecular detection depends upon the ability of DNA to resist digestion in the predator gut and of the polymerase chain reaction (PCR) to amplify prey-specific DNA from semidigested material. As a first step, experiments using carabid beetles, Pterostichus cupreus L., as predators and mosquitoes as prey are reported. The target sequences were fully characterized multiple-copy esterase genes from two laboratory strains of Culex quinquefasciatus Say. Although DNA was extracted from homogenates of whole beetles (minus appendages), a 146 bp product could be amplified from both mosquito strains digested in the beetle gut for 28 h. The larger, 263 bp product was detectable for 28 h in one mosquito strain, but could not be amplified after 5 h from the other. Whether the beetles had eaten one mosquito or six, digested for zero or 28 h, the prey were equally detectable. Having demonstrated that shorter, multiple-copy sequences survive digestion for a considerable period in the gut of a predator, the opportunity exists to develop new detection systems for studying predation in the field.  相似文献   
53.
Mechano-electric feedback and atrial fibrillation   总被引:4,自引:0,他引:4  
Atrial fibrillation frequently occurs under conditions associated with atrial dilatation suggesting a role of mechano-electric feedback in atrial arrhythmogenesis. Although atrial arrhythmias may be due both to abnormal focal activity and reentrant mechanisms, the majority of sustained atrial arrhythmias have been ascribed to reentrant activity. Atrial stretch may contribute to focal arrhythmias by inducing afterdepolarizations and to reentrant arrhythmias by increasing the atrial surface, by shortening the refractory period and/or slowing the conduction velocity and by increasing their spatial dispersion. Experimental and clinical studies have demonstrated that changes in mechanical loading conditions may modulate the electrophysiological properties of the atria. These studies have, for the most part, involved the effects of acute stretch on atrial refractoriness. While studies in humans and intact animals yield divergent results due to the variety of loading conditions and neurohumoral influences, experimental studies in isolated preparations clearly show that atrial refractory period and action potential duration at early levels of repolarization shorten by acute atrial dilatation. Both experimental and human studies have shown that acute atrial stretch is arrhythmogenic and may induce triggered premature beats and atrial fibrillation.  相似文献   
54.
The rotifers of Lake Peipus   总被引:1,自引:0,他引:1  
Virro  Taavi  Haberman  Juta 《Hydrobiologia》1993,255(1):389-396
In the northern part of Lake Peipus, 140 taxa of rotifers were identified, with species of Anuraeopsis, Conochilus, Keratella, Polyarthra and Synchaeta dominating. Two main periods of sexual reproduction occur, in the spring and autumn. Different life cycle patterns are represented. Rotifer number and biomass have two maxima between spring and early autumn. The contribution of rotifers to total zooplankton production varies from 13.6% (Oct.) to 89.8% (May). The average production of grazing rotifers is 485.1 kJ m–2, while that of predatory rotifers (Asplanchna) is 10.0 kJ m–2.  相似文献   
55.
声音通讯在凹耳蛙(Odorrana tormota)的繁殖过程中起到关键作用,雄性凹耳蛙个体处于不同性选择压力下会采取不同的发声策略,然而相关研究仍缺乏。本实验采用个体标记法,基于2021年3-5月的野外实验,对雄性凹耳蛙个体(n=12)处于合唱高潮期和低潮期鸣声中的非线性发声现象(nonlinear vocal phenomena,以下简称NLP)总含量及其各组分(混音、半谐波、频率跳跃)含量、鸣声时长以及鸣叫频次之间的差异进行Wilcoxon符号秩检验。结果显示,雄蛙处于合唱高潮期和低潮期鸣声中的部分NLP组分(混音、半谐波)含量以及鸣声时长均没有显著性差异,合唱低潮期的NLP总含量、部分NLP组分(频率跳跃频次)显著大于高潮期,合唱高潮期的发声率显著大于低潮期。实验结果表明,雄性凹耳蛙不同合唱期会采取不同的发声策略,即性选择压力较小的低潮期通过提高鸣声中的NLP含量、扩大声音传播距离、增大声音的不可预测性来更好吸引雌性;高潮期性选择压力大时,雄蛙通过提高鸣叫频次使得个体鸣声更加突出,从而提高抱对成功率。  相似文献   
56.
Abstract: A statistically designed set of eight bio-oxidation tests on the Olympias concentrate was conducted in bench-scale equipment to evaluate the effects of important variables on pyrite/arsenopyrite oxidation and gold extraction. The variables studied were total retention time, feed solid concentration and particle size. High degrees of arsenopyrite oxidation were observed in all tests, as the arsenopyrite oxidation was very fast and therefore not dependent on the variables within the studied range. Statistical analysis of the experimental data reveals that the pyrite oxidation and gold extraction are dependent mainly on the retention time and to a lesser extent on the particle size. The feed solid concentration had a small influence only on the gold extraction. Regressed equations of the experimental data can be used to predict proper operating conditions.  相似文献   
57.
Abstract: Oxidation of a fraction of the pyrite in gold-bearing pyrite ores before leaching often increases gold recovery rates. There are a number of techniques availablc, one of which is dump oxidation. Commercial viability of such an operation requires a net oxidation of 50% or more in 1 year. This is possible in a dump provided convection is established quickly. Since convection requires temperatures in the dump to be well above ambient, a question arises as to the constraints that might be imposed by the upper temperature limit ( T kill) of the microorganisms which catalyse the oxidation of the pyrite. Our objective is to investigate, by way of a computer model, the importance of T kill as a parameter effecting the oxidation rate and the fraction of pyrite oxidised after 1 year in dumps where the goal is to oxidise about 50% of the pyrite in a year or less.  相似文献   
58.
Abstract: Two years of BIOX pilot plant data have been examined for steady state conditions and then correlated using logistic kinetics. It was found that the logistic equation not only predicted the performance of individual stages but also the degree of biooxidation across the entire cascade of bioreactors. It was found that the rate constant was 1.3 day-1 in the first three stages and 0.3 day-1 in the fourth stage. The maximum removal constant was 0.90 in stage 1 and 0.99 in the remaining stages. Plant retention time ranged from 4 to 12 days with corresponding sulphide oxidation varying from 82 to 98% respectively, and primary stage removal rates varying from 8.9 to 4.4 kg m-3 day-l, respectively. In addition, batch biooxidation data were obtained. The biooxidation rate was found to be about half that for the continuous bioreactors. This is in agreement with the findings of several other workers. The specific rates of bioxidation of pyrite and arsenopyrite were very similar for the bulk concentrate at about 0.15 day-1. However, it was significant that the biooxidation of arsenopyrite in the mixed mineral preceded that of pyrite, suggesting a sequential mechanism. Gold liberation was found to be linearly related to arsenopyrite biooxidation but oxidation of pyrite appears to be preferential in the gold-rich regions.  相似文献   
59.
The K2S2O8 assisted photocatalytic system was applied for treating refractory petrochemical wastewater. Co-TiO2/zeolite catalyst synthesized by sol-gel method was demonstrated to possess a good activity towards mineralization of the refractory petrochemical wastewater in the K2S2O8 assisted photocatalytic system. Orthogonal design was employed to optimize the reaction parameters, according to the results, K2S2O8 dosage was the most prominent impact factor. More experiments were conducted to further enhance the COD removal efficiency. In consideration of both efficiency and costs, the petrochemical wastewater was treated in the K2S2O8 assisted photocatalytic system at pH 4, K2S2O8 dosage 2.03 g/L, catalyst amount 250 g/L with irradiation by 1 lamp and aeration. The COD removal efficiency reached up to 93.4% with a rate constant of 1.14 × 10−2 per min, and Co-TiO2/zeolite showed a good stability towards the K2S2O8 assisted photocatalytic degradation of petrochemical wastewater.  相似文献   
60.
Dog-days, cold periods, grape-harvests (France, 15-19th centuries). The climate history can be based on several kinds of data. In the present paper, French records of grape-harvest dates in Burgundy from 1370 to 1890 were used for evaluate the climates at these various period of time. These results reveal that temperatures as high as those reached in the 1990s have occurred several times in Burgundy since 1370. Correlations between temperatures and historic data are presented.  相似文献   
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