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991.
以全胚胎培养模型结合免疫组化和电镜技术等探讨了乙酰水杨酸和叶酸对大鼠卵黄囊及胚胎的影响。结果表明:培养基含乙酰水杨酸300μg/ml组的卵黄囊直径和胚胎体长均显著低于阴性对照组,胚胎畸形率明显增高。组织学检查发现卵黄囊厚度变薄。间质层血岛、微血管数量明显减少,血管壁细胞不连续,血管发育不良。卵黄囊内皮层细胞顶端微绒毛少见。内皮层细胞的溶酶体、内质网及核蛋白体等结构和数量均有明显改变。而60mg/kg叶酸灌胃鼠血清与乙酰水杨酸联合应用后,则卵黄囊的上述毒性作用明显减轻或消失,提示叶酸能明显拮抗乙酰水杨酸致大鼠卵黄囊的毒性作用。 相似文献
992.
1992年中国总膳食研究在1990年的基础上做了适当的改进,将城市和农村的样品分别进行分析。本文报道了该项研究中膳食脂质部分的结果(包括总脂肪、胆固醇、脂肪酸)。除南方二区外,同一地区的城市和农村居民在脂肪、胆固醇的摄入量上有较大的差异。北方二区农村居民的脂肪摄入量明显不足,而北方一区城市居民脂质的摄入量较高,胆固醇摄入量已超过每人每日300m g 的水平。南方居民膳食脂肪中多不饱和脂肪酸所占比例低而单不饱和脂肪酸所占比例高。基于以上分析,作者认为我国居民膳食脂质摄入情况基本合理,但由于地域差异较大,在进行膳食指导时(如关于补充EPA,DHA 的问题)应对不同地区的情况进行具体分析,有针对性地提出建议 相似文献
993.
地砷病患者部分生化指标的测定 总被引:2,自引:0,他引:2
对病区地砷病、非地砷病患者及对照组居民体内的部分生化指标进行了检测。结果表明,地砷病患者血清中的GPT活性、UN和SA含量明显高于对照组,LDH及GSHPx活性明显降低;病区非地砷病患者LDH活性、SA含量明显升高,GSHPx活性明显降低,其它各组及各指标与对照组相比无显著差异。相关分析显示,病区病人组及非病人组血中SA含量与各自尿砷水平呈正相关(r=050,r=046),GSHPx与尿砷呈负相关(r=-051,r=-048)。提示,SA和GSHPx可作为砷中毒的早期诊断指标。砷可能对接砷居民肝功、肾功产生一定影响。 相似文献
994.
995.
M. A. Richardson Margaret A. Reilly Laura L. Read Cheryl J. Flynn Raymond F. Suckow Timothy J. Maher Istvan Sziraki 《Psychopharmacology》1999,143(4):347-357
Rationale: An association between tardive dyskinesia (TD) and severely impaired metabolism of the large neutral amino acid (LNAA),
phenylalanine (Phe) was defined in a group of mentally retarded patients. Subsequently, an altered kinetics of Phe was associated
with TD in men with schizophrenia based on plasma analyses subsequent to the ingestion of a protein meal. Methods: In the present study, a standardized oral challenge of pure Phe (100 mg/kg in 170 ml orange juice) was administered to psychiatric
patients of both sexes (n = 312), with and without TD after an overnight fast. Plasma LNAA levels were assayed both fasting and 2 h subsequent to the
ingestion of the challenge. The extent of the increase in plasma Phe levels 2 h following a standardized challenge is determined
by the sum of the kinetic processes of plasma absorption, tissue distribution, metabolism and elimination. Results: The study hypothesis, that TD would be associated with significantly higher post-challenge plasma Phe indices of an absolute
plasma Phe level and plasma Phe/LNAA ratio (a brain availability measure), was verified for the study men (n = 209), but not for the study women (n = 103). Conclusions: The demonstrated altered kinetics of Phe in men with TD indicates a greater availability of Phe to the brain in these men.
We suggest that the disorder may be related to the effects of this greater availability. Such effects could be the direct
neurotoxic effects of Phe and its metabolites and/or the modulating effects of these compounds on the synthesis of the monoamine
neurotransmitters. The fact that TD (Yes/No) group differences in post-challenge plasma Phe indices were not seen for the
study women suggests the possibility of a sex difference in the biology of TD that we propose may be reflective of the young
age of the study sample.
Received: 28 January 1998/Final version: 14 December 1998 相似文献
996.
997.
Helmuth Adelsberger Nicolas von Beckerath Franz Parzefall Josef Dudel 《Pflügers Archiv : European journal of physiology》1996,431(5):680-689
Single-channel measurements were performed with the aim of constructing a detailed molecular scheme for the reaction between -aminobutyric acid (GABA) and a chloride channel of crayfish deep extensor abdominal muscle (DEAM). GABA was applied in pulses to outside-out patches of muscle membrane, and, based on the dose-response of the peak currents and of their rise times, a linear model with five binding steps has been proposed. Evaluation of the single-channel kinetics indicated at least three open states. Two of them originate most probably from the fully liganded receptor state and are grouped in mixed bursts due to their different life times. The third one appears independently, outside the bursts, and originates from a lower liganded receptor state. Simulations of the dose-responses and the open time distributions with this model led to a set of rate constants which generated relatively optimal fits. 相似文献
998.
Summary Impaired -6 essential fatty acid metabolism and exaggerated polyol pathway flux contribute to the neurovascular abnormalities in streptozotocin-diabetic rats. The potential interactions between these mechanisms were examined by comparing the effects of threshold doses of aldose reductase inhibitors and evening primrose oil, alone and in combination, on neurovascular deficits. In addition, highdose aldose reductase inhibitor and evening primrose oil treatment effects were challenged by co-treatment with the cyclo-oxygenase inhibitor, flurbiprofen, or the nitric oxide synthase inhibitor, NG-nitro-l-arginine. Eight weeks of diabetes caused an 18.9% reduction in sciatic motor conduction velocity (p<0.001). This was only modestly ameliorated by a 0.1% dietary supplement of evening primrose oil or the aldose reductase inhibitors ZD5522 (0.25 mg · kg–1 · day–1) and WAY121509 (0.2 mg · kg–1· day–1) for the final 2 weeks. However, joint treatment with primrose oil and ZD5522 or WAY121509 caused marked 71.5 and 82.4% corrections, respectively, of the conduction deficit. Sciatic nutritive blood flow was 43.1% reduced by diabetes (p<0.001) and this was corrected by 67.8% with joint ZD5522 and primrose oil treatment (p<0.001). High-dose WAY121509 (10 mg · kg–1 · day–1) and primrose oil (10% dietary supplement) prevented sciatic conduction velocity and nutritive blood flow deficits in 1-month diabetic rats (p<0.001). However, these effects were abolished by flurbiprofen (5 mg · kg–1 · day–1) and NG-nitro-l-arginine (10 mg · kg–1 · day–1) co-treatment (p<0.001). Thus, the data provide evidence for synergistic interactions between polyol pathway/nitric oxide and essential fatty acid/cyclo-oxygenase systems in the control of neurovascular function in diabetic rats, from which a potential therapeutic advantage could be derived.Abbreviations ARI
Aldose reductase inhibitor
- EPO
evening primrose oil
- NCV
nerve conduction velocity
- NO
nitric oxide
- NOLA
NG-nitro-l-arginine 相似文献
999.
Micheline Glauser MS Peter Bauerfeind MD Wolfgang Feil MD Martin Riegler MD Robert Fraser MD André L. Blum MD 《Digestive diseases and sciences》1996,41(5):964-971
Acid inhibition increases gastric mucosal susceptibility to damage by luminal acid. This might be due to reduced metabolic CO2 and bicarbonate whereas, during normal acid, secretion cytoprotective CO2/HCO3- production parallels acid production. Metabolic activity and mucosal damage caused by luminal acid perfusion was determined in anin vitro mouse stomach, with and without acid inhibition, and at 0%, 1%, or 5% serosal CO2 supply. Without acid inhibition there was no mucosal damage at any level of serosal CO2/HCO3- supply. Acid inhibition reduced metabolic CO2 production by 29% (P<0.004) and resulted in microscopic damage to 55% of the mucosal area and perforation in four of five stomachs (P<0.05). Although, 1% CO2 supply completely replaced the reduction in metabolic CO2, it did not protect against mucosal damage. Overreplacement by 5% serosal CO2/HCO3- was required to prevent damage. There was no correlation between luminal CO2/HCO3- output and mucosal damage. The protection by endogenous or exogenous CO2/HCO3- appears to act intracellularly rather than by intragastric or intercellular neutralization.This study was supported by Swiss National Foundation grants 32-26369.89 and 32-33626.92. The morphometry equipment was supported by a grant from the Osterreichische Nationalbank. 相似文献
1000.
Toshi Nomura Katsuhiro Inoue Cyrus R. Creveling Fuhito Komatsu Norio Ohta Takehiro Chino Nobuyuki Karasawa Ikuko Nagatsu 《Brain research》1996,735(2):314
Relatively large amounts of DOPA as compared with the concentration of norepinephrine are found in human dental pulp. AADC and COMT are localized in blood vessel walls of human dental pulp. This localization suggests a functional relationship between COMT and AADC with regard to the metabolism of DOPA. 相似文献