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81.
目的 建立芜菁子药材中槲皮素和山奈酚定量测定方法及芜菁子中黄酮类化合物的指纹图谱,为芜菁子质量控制提供依据。方法 采用HPLC测定芜菁子药材中槲皮素和山奈酚的含量及建立芜菁子指纹图谱,色谱条件为ODS C18 (4.6 mm×250 mm,5 μm),流动相为甲醇(A)-0.4%磷酸水溶液(B),梯度洗脱,流速0.7 mL·min-1,检测波长254 nm,柱温30 ℃。结果 样品中槲皮素和山奈酚的含量分别为0.013 1~0.035 6 mg·g-1及0.022 0~0.048 0 mg·g-1,平均回收率分别为102.8%和99.5%。芜菁子指纹图谱中有11个共有峰,对10批次芜菁子样品的指纹图谱进行相似度比较,相似度较高。结论 该方法重现性好,可行性强,可用于芜菁子的质量评价。  相似文献   
82.
目的比较不同产地北细辛的种质特征。方法根据《中华人民共和国国家标准-农作物种子检验规程》和自建的马兜铃酸A检测方法,对8个产地的北细辛种子进行了水分、生活力、千粒质量、发芽率和马兜铃酸A含量的测定,并用SPSS13.0软件对检测结果进行聚类分析。结果各产地的种子总体上粒大饱满,活力较好,但水分都比较高,且都含有马兜铃酸A。结论清原县北三家乡和本溪谢家所产的北细辛种子从总体上来看,水分和马兜铃酸A的含量较低,生活力等其他指标较高,质量相对比较好。  相似文献   
83.
莱菔子是祖国传统药食同源物品,含油率高达45%,油中不饱和脂肪酸占到主要脂肪酸的90%,亚麻酸含量普遍高于其他油用作物,莱菔素具有显著的抗癌活性。该文对莱菔子油的成分研究、莱菔素的药理作用进行了综述,探讨了莱菔子油在药用、食用保健及工业等领域的应用价值,为莱菔子油的进一步开发利用提供参考。  相似文献   
84.
目的研究饱和水溶液法制备β-环糊精(β-CD)茶籽油包合物的最佳工艺。方法采用单因素和正交实验方法,以茶籽油的包合物收率、含油率与理论含油率比值和包合率为考察指标进行评分,优化包合工艺;并采用薄层层析法、红外光谱分析方法对包合物进行验证。结果最佳包合条件为:包合温度55℃、包合时间4h、β-CD与茶籽油比例4∶1(g∶g)。结论所优选的工艺条件操作简便,收率、含油率和包合率高,适用于生产。  相似文献   
85.
目的探讨铁树果中毒的临床表现、中毒机制及治疗方法。方法对2013年9月17日本市某中学铁树果中毒38例患者病历资料进行回顾性分析。结果中毒患者中,28.95%出现消化道症状,15.79%出现头痛、头昏症状,26.32%出现心肌酶谱异常。结论铁树果口服有轻度毒性,急性中毒主要表现为消化道和神经系统症状,经催吐、洗胃及对症治疗后可痊愈。  相似文献   
86.
Piezoelectric nanogenerators (NGs) consist of zinc oxide nanorods (ZNRs), and polydimethylsiloxane (PDMS) layers were fabricated on indium tin oxide (ITO)-coated substrate for the energy harvesting system. The formation of seed layers by an optimized aqueous solution method greatly helped the growth of well-aligned ZNRs for NGs. Polyethylenimine (PEI) was added to increase the aspect ratio of ZNRs, which reached up to 24:1, showing the best energy harvesting performance of NGs. The formation of PDMS layers on the ZNRs increased the work function difference for the top Ag electrode. The thickness of PDMS layers was optimized as 80 μm, which showed the maximum work function difference, resulting in the enhancement of charge density. Piezoelectric NGs made of ZNRs of the highest aspect ratio of 24:1 with an 80-μm-thick PDMS layer achieved the highest current density of 2270.1 nA/cm2, which could be sufficient to drive low-power electronics.  相似文献   
87.
目的 观察125I粒子覆膜食管支架对于正常兔食管组织的放射性损伤.方法 将实验用兔分两组,每组各6只,实验组置入125I粒子支架(单颗粒子剂量22.2MBq ×3颗粒子),对照组植入无放射粒子的支架.于支架植入后2、4、8周分别取实验组和对照组兔2只,行食管造影,观察支架、粒子移位情况,处死后取标本行肉眼、显微镜观察.结果 支架释放过程及术后随访未发现125I粒子脱落.所有动物未发现穿孔等严重并发症.实验组术后2周,食管中部仅为轻微的病理学损伤,鳞状上皮明显增生.黏膜卜炎性细胞浸润.术后4周,出现肉芽组织增生,少量纤维组织增生.术后8周,肉芽组织、纤维结缔组织进一步增生.粒子相对处的食管组织损伤程度明显轻于粒子接触处食管组织.对照组支架中间部分食管与正常食管组织相似,可见食管鳞状卜皮轻增生.支架两端实验组和对照组局部增生食管组织覆盖支架,可见肉芽组织、纤维结缔组织明显增牛.结论 125I粒子支架置人正常兔食管壁组织造成病理性改变,主要表现为肉芽组织、纤维结缔组织增生,无出血、穿孔.  相似文献   
88.
目的探讨不同放射剂量的^125I粒子对BGC823人低分化胃癌细胞的影响。方法将BGC823人低分化胃癌细胞悬液种植于64只BLAB nu/nu裸鼠的皮下,以制备荷瘤鼠模型。待荷瘤鼠模型饲养3周左右、肿瘤生长至0.7-1.2 cm时,将其随机分为4组:空白对照组、低剂量组、中剂量组及高剂量组(n=16)。其中,空白对照组裸鼠植入空白粒子,低、中及高剂量组分别植入放射剂量为1.48×10^-7、2.22×10^-7及2.96×10^-7 Bq的^125I粒子。分别于粒子植入前、植入后7、14、21及28 d,4组均随机抽取4只荷瘤鼠处死,剥取瘤体称重,并计算肿瘤体积;分别于植入粒子后14d和28d,测量4组荷瘤鼠肿瘤组织的细胞凋亡率和细胞周期因子E(cyclinE)mRNA的表达水平。结果①除空白对照组外(空白对照组的变化不大),低、中及高剂量组的肿瘤体积和肿瘤质量随时间延长均呈下降趋势。粒子植入后7、14、21及28d,低、中及高剂量组的肿瘤体积和肿瘤质量均小于(轻于)空白对照组(P〈0.05),且在28 d时,低剂量组的肿瘤体积和肿瘤质量均小于(轻于)中剂量组和高剂量组(P〈0.05)。②14d和28d时,低、中及高剂量组的凋亡率均高于空白对照组(P〈0.05),而cyclinE mRNA的表达水平均低于空白对照组(P〈0.05)。28d时,低剂量组的凋亡率高于中剂量组和高剂量组(P〈0.05),而cyclinE mRNA的表达水平却低于该2组(P〈0.05)。同组内与14d比较,28 d时除空白对照组的差异无统计学意义外(P〉0.05),其余3组的凋亡率均较高(P〈0.05),而cyclinE mRNA的表达水平均较低(P〈0.05)。结论 ^125I粒子组织间植入可有效抑制人低分化胃癌组织的生长,可抑制其cyclinE mRNA的表达;与其他剂量相比(2.22×10^-7 Bq及2.96×10^-7 Bq),低剂量(1.48×10-7 Bq)的125I粒子持续照射可诱导BGC823人低分化胃癌细胞的凋亡增加。  相似文献   
89.
Ecologists seek general explanations for the dramatic variation in species abundances in space and time. An increasingly popular solution is to predict species distributions, dynamics, and responses to environmental change based on easily measured anatomical and morphological traits. Trait-based approaches assume that simple functional traits influence fitness and life history evolution, but rigorous tests of this assumption are lacking, because they require quantitative information about the full lifecycles of many species representing different life histories. Here, we link a global traits database with empirical matrix population models for 222 species and report strong relationships between functional traits and plant life histories. Species with large seeds, long-lived leaves, or dense wood have slow life histories, with mean fitness (i.e., population growth rates) more strongly influenced by survival than by growth or fecundity, compared with fast life history species with small seeds, short-lived leaves, or soft wood. In contrast to measures of demographic contributions to fitness based on whole lifecycles, analyses focused on raw demographic rates may underestimate the strength of association between traits and mean fitness. Our results help establish the physiological basis for plant life history evolution and show the potential for trait-based approaches in population dynamics.Recent evidence for global patterns of functional variation in plants, such as the leaf economics spectrum (1, 2), the wood economics spectrum (3), and the seed size–seed number tradeoff (4, 5), has convinced many ecologists that functional traits offer the best available approach for achieving a general predictive understanding of communities and ecosystems (6, 7). Trait-based approaches are now being used to predict the outcome of community assembly (810), global vegetation dynamics (11), and the rate of ecosystem processes (6, 1214). A central assumption of trait-based ecology is that morphological traits determine physiological performance, which influences vital rates and determines individual fitness and life history evolution (15, 16). However, because of the challenge of quantifying the contribution of traits to fitness, the assumed links between functional traits and life history have not been fully tested.Research in tropical and Mediterranean forests has revealed cross-species relationships between functional traits and the survival and growth rates of individuals (3, 1724). Although these relationships provide evidence that functional traits influence vital rates, they offer only limited insight into associations between those traits and individual fitness and life history. Vital rates (e.g., survival and fecundity) represent fitness components, but their influence on mean fitness, defined as the population growth rate (λ), is best understood in the context of the full lifecycle of a species (25, 26). A significant negative correlation between wood density and individual growth (18) might not translate into a significant effect on mean fitness if individual growth has little influence on λ. Conversely, a weak relationship between a functional trait and another vital rate could have a significant effect on mean fitness if that vital rate has a strong influence on λ. Perturbation analyses, such as the sensitivities and elasticities frequently applied to matrix projection models (27), address this problem by quantifying the contribution of vital rates to λ (28), making it possible to characterize a species'' overall life history in terms of the relative importance of survival, individual growth, and fecundity to mean fitness. Species with slow life histories have population growth rates with high elasticities to survival, whereas species with fast life histories have relatively higher elasticities to individual growth or fecundity (29, 30).Armed with vital rate elasticities, we can test quantitative hypotheses about whether functional tradeoffs scale up to generate life history tradeoffs. For example, plants can allocate their reproductive effort to provision a few large seeds, which tolerate low light and resource availability and have a high survival probability, or they can spread their reproductive effort among many small seeds, maximizing fitness under high resource availability (31, 32). If this functional tradeoff at the seedling stage translates into a life history tradeoff, seed mass should be positively related to the elasticity of the population growth rate to survival and negatively related to elasticities to individual growth and fecundity. The leaf economics spectrum represents another allocation tradeoff. Species can construct long-lived, well-defended leaves that are often favored in low resource environments or build leaves that assimilate carbon quickly under conditions of high resource availability but are prone to rapid tissue loss (1, 33). Species with slow leaf economics traits, such as long leaf lifespans, low specific leaf area (SLA), and low leaf N, might also lead slow lives, characterized by high elasticities to survival and low elasticities to individual growth and recruitment. A wood economics spectrum also exists: species with dense wood tend to have higher survival but lower relative growth rates than species with soft wood (3, 34). Elasticities to survival should increase with wood density, whereas elasticities to individual growth and fecundity should decrease.The main obstacle in testing these hypotheses is availability of the detailed demographic data necessary to describe a species’ full lifecycle and estimate vital rate elasticities. We overcame this limitation by crossing the TRY Global Plant Traits Database (35) with the COMPADRE Plant Matrix Database (www.compadre-db.org/), a collection of published matrix population models. This approach produced a dataset of 222 plant species spanning a global range of biomes and perennial growth forms (Table S1), for which we have at least one functional trait measurement as well as a matrix population model that we used to calculate the elasticity of the population growth rate to each of the three vital rates: survival, growth, and fecundity (30).Our primary objective was to evaluate the ability of functional traits to explain variation across species in life history, which we quantified with vital rate elasticities. Our secondary objective was to evaluate whether inferences about life history can be drawn directly from the raw vital rates, which would save researchers the considerable time and effort required to parameterize population models and calculate elasticities. We used two statistical approaches to quantify relationships between vital rate elasticities and seed mass, wood density, and leaf economics traits (leaf lifespan, SLA, and leaf N). Dirichlet regression is a multivariate approach that accounts for the fact that the survival, growth, and fecundity elasticities for each species sum to one but does not account for phylogenetic relationships. Phylogenetic generalized least squares (PGLS) regression ignores the nonindependence of the elasticities but accounts for phylogenetic relationships. We repeated both types of regressions with plant growth form and then biome included as covariates to confirm that trait effects did not simply represent differences between trees and herbaceous species or plants adapted to different environments.  相似文献   
90.
目的:通过研究小鼠海马神经元细胞系HT22细胞糖氧剥夺(OGD)后凋亡/自噬相关蛋白表达的变化,探讨葡萄籽原花青素提取物(GSPE)预处理对OGD诱导的HT22细胞损伤的保护作用。方法:将HT22细胞分为对照组、OGD组、OGD+GSPE组。CCK8法检测OGD不同时间(4、6、8 h)干预后HT22细胞的活性,确定后续实验中OGD时间;CCK8法检测同一OGD时间下,不同GSPE浓度(20、40、100、200μmol/L)处理后HT22细胞的活性,确定GSPE最佳浓度;免疫荧光技术标记Tubulin蛋白,观察细胞形态的改变;AnnexinⅤ-FITC/PI染色和TUNEL染色检测细胞凋亡;免疫荧光技术检测Bax、Bcl-2、cleaved caspase-3、LC3Ⅱ和Beclin1等蛋白的表达量变化;caspase-3活性检测试剂盒检测caspase-3相对活性。结果:观察细胞形态结果表明:对照组细胞形态完整、胞体较大,OGD组中细胞大量皱缩成团、胞体变小,OGD+GSPE组细胞状态较OGD组明显改善;观察细胞凋亡情况结果表明:和OGD组相比,GSPE预处理后的HT22细胞,凋亡阳性细胞明显减少(P<0.01);免疫荧光结果表明GSPE预处理能抑制HT22细胞中Bax、cleaved caspase-3、LC3Ⅱ和Beclin1的表达并促进Bcl-2的表达。结论:OGD对HT22细胞损伤明显,GSPE预处理可以减轻OGD对HT22细胞损伤并显著提高细胞活性,其作用机制可能与其抑制细胞凋亡和细胞自噬有关。  相似文献   
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