首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   2913篇
  免费   151篇
  国内免费   5篇
耳鼻咽喉   16篇
儿科学   46篇
妇产科学   32篇
基础医学   416篇
口腔科学   46篇
临床医学   234篇
内科学   747篇
皮肤病学   25篇
神经病学   184篇
特种医学   88篇
外科学   402篇
综合类   17篇
一般理论   1篇
预防医学   158篇
眼科学   96篇
药学   295篇
中国医学   4篇
肿瘤学   262篇
  2023年   20篇
  2022年   19篇
  2021年   43篇
  2020年   22篇
  2019年   35篇
  2018年   52篇
  2017年   30篇
  2016年   52篇
  2015年   46篇
  2014年   72篇
  2013年   60篇
  2012年   112篇
  2011年   130篇
  2010年   80篇
  2009年   49篇
  2008年   105篇
  2007年   117篇
  2006年   142篇
  2005年   144篇
  2004年   136篇
  2003年   137篇
  2002年   117篇
  2001年   120篇
  2000年   131篇
  1999年   107篇
  1998年   28篇
  1997年   17篇
  1996年   27篇
  1994年   15篇
  1993年   17篇
  1992年   78篇
  1991年   64篇
  1990年   67篇
  1989年   69篇
  1988年   39篇
  1987年   68篇
  1986年   61篇
  1985年   51篇
  1984年   46篇
  1983年   41篇
  1982年   22篇
  1981年   17篇
  1980年   16篇
  1979年   37篇
  1978年   20篇
  1975年   22篇
  1969年   20篇
  1968年   15篇
  1967年   14篇
  1966年   20篇
排序方式: 共有3069条查询结果,搜索用时 15 毫秒
71.
72.
The use of allogeneic, pluripotent stem‐cell‐derived immune cells for cancer immunotherapy has been the subject of recent clinical trials. In Japan, investigator‐initiated clinical trials will soon begin for ovarian cancer treatment using human leukocyte antigen (HLA)‐homozygous‐induced pluripotent stem cell (iPSC)‐derived anti–glypican‐3 (GPC3) chimeric antigen receptor (CAR)‐expressing natural killer/innate lymphoid cells (NK/ILC). Using pluripotent stem cells as the source for allogeneic immune cells facilitates stringent quality control of the final product, in terms of efficacy, safety and producibility. In this paper, we describe our methods for the stable, feeder‐free production of CAR‐expressing NK/ILC cells from CAR‐transduced iPSC with clinically relevant scale and materials. The average number of cells that could be differentiated from 1.8‐3.6 × 106 iPSC within 7 weeks was 1.8‐4.0 × 109. These cells showed stable CD45/CD7/CAR expression, effector functions of cytotoxicity and interferon gamma (IFN‐γ) production against GPC3‐expressing tumor cells. When the CAR‐NK/ILC cells were injected into a GPC3‐positive, ovarian‐tumor‐bearing, immunodeficient mouse model, we observed a significant therapeutic effect that prolonged the survival of the animals. When the cells were injected into immunodeficient mice during non–clinical safety tests, no acute systemic toxicity or tumorigenicity of the final product or residual iPSC was observed. In addition, our test results for the CAR‐NK/ILC cells generated with clinical manufacturing standards are encouraging, and these methods should accelerate the development of allogeneic pluripotent stem cell‐based immune cell cancer therapies.  相似文献   
73.
74.
75.
The mechanisms that explain mitochondrial dysfunction in aging and healthspan continue to be studied, but one element has been unexplored: microproteins. Small open reading frames in circular mitochondria DNA can encode multiple microproteins, called mitochondria-derived peptides (MDPs). Currently, eight MDPs have been published: humanin, MOTS-c, and SHLPs 1–6. This Review describes recent advances in microprotein discovery with a focus on MDPs. It discusses what is currently known about MDPs in aging and how this new understanding could add to the way we understand age-related diseases including type 2 diabetes, cancer, and neurodegenerative diseases at the genomic, proteomic, and drug-development levels.  相似文献   
76.
Background: It has been unclear whether psychological distress and prevalence of metabolic syndrome (MS) is associated independent of cardiorespiratory fitness and/or visceral fat area in patients with type 2 diabetes mellitus (type 2 DM). Methods: Ninety-seven newly diagnosed Japanese men with type 2 DM (aged 26-81) who did not receive any intervention or pharmacological therapy were divided into two groups of highly distressed (HD) and less distressed (LD) by the cutoff point of the General Health Questionnaire (GHQ). In addition, cardiorespiratory fitness (estimated oxygen uptake: [Formula: see text] O(2)max), visceral fat area (VFA), glucose and lipid metabolism, and resting blood pressure were assessed. MS was defined based on the criteria proposed by the World Health Organization (WHO). The odds-ratios (OR) for the frequency of a low level of fitness, extremely accumulated VFA, metabolic abnormalities, and MS in both groups were calculated using a logistic regression model. Results: The OR for the frequency of a low level of fitness, the top quartile of VFA, hyperinsulinemia, and MS were significantly higher in the HD than in the LD. The significantly high OR of hyperinsulinemia and MS in the HD disappeared after adjusting for [Formula: see text] O(2)max and/or VFA. Conclusions: Our study suggests that the association of psychological distress with hyperinsulinemia and MS might depend on cardiorespiratory fitness and/or VFA in Japanese men with type 2 DM.  相似文献   
77.
Abstract: Fifteen psychiatric cases are reported who were clinically diagnosed as schizophrenic, affective disorders, or neurotic, but resisted standard medication regimens, all showing irregular β activities on EEGs. The cases tended to display symptoms in common, such as dysphoria, emotional instability or frequent physical complaints. These characteristic symptoms share something mutually with the symptoms shown in some epileptic patients or psychiatric patients with epileptic EEG abnormalities without clinical seizures. Antiepileptic drugs seemed more specifically effective to the above symptoms. More than half of these cases showed improvement on EEG findings such as a decrease in irregular β activities and an increase in rhythmicity or regularity of α activities along with clinical improvement with the administration of adjunctive antiepileptic drugs. These results suggest that the adjunctive administration of antiepileptic drugs to patients with irregular β activities on EEGs is clinically useful and an EEG examination has much value in psychiatric practice to find the criteria of drug therapy.  相似文献   
78.
Motor nerve conduction velocity of the ulnar nerve was measured in 54 infants of various ages. Conduction velocity of slower fibres was measured using Hopf's technique, and maximal conduction velocity was measured with the usual method. Both maximal conduction velocity and conduction velocity of slower fibres increased with maturation. The former was about 65 m/s at the age of about 3-5 years, but thereafter it decreased slightly to about 60 m/s. Conduction velocity of slower fibres increased gradually until about 3 or 4 years of age, and then ranged about 40-50 m/s. The difference between the two velocities increased until 7 or 9 months of age; during the next 8 years, it tended to decrease to about 8-16 m/s. The increasing difference in size between the largest and the smallest myelinated fibres with maturation correlated with the developmental increase of the difference between maximal conduction velocity and conduction velocity of slower fibres. The anatomical evidence of the slight decrease of the axon diameter of the large fibres at the age of 7-14 years may correspond to the slight reduction of maximal conduction velocity after about 5 years of age.  相似文献   
79.
BACKGROUND: Glandular atrophy and intestinal metaplasia are precancerous lesions; whether Helicobacter pylori eradication affects these lesions is controversial. OBJECTIVE: To determine whether H. pylori eradication is associated with improvement in glandular atrophy and intestinal metaplasia after at least 1 year. DESIGN: Single-blind, uncontrolled prospective trial. SETTING: Academic gastroenterology clinic in Japan. PATIENTS: 163 consecutive patients with dyspepsia and H. pylori infection. INTERVENTION: One-week course of a proton-pump inhibitor and antibiotic therapy. MEASUREMENTS: Endoscopic examination with antral and corporal biopsy was done before treatment and at 1 to 3 and 12 to 15 months after treatment. Gastritis, atrophy, and metaplasia were graded according to the updated Sydney System. RESULTS: In the 115 patients in whom H. pylori was eradicated, inflammation and mean neutrophil activity had decreased by 1 to 3 months, and both glandular atrophy in the corpus and intestinal metaplasia in the antrum had decreased by 12 to 15 months. Glandular atrophy in the corpus improved in 34 (89%) of 38 patients with atrophy before treatment, and intestinal metaplasia in the antrum improved in 28 (61%) of 46 patients who had metaplasia at baseline. In the 48 patients in whom eradication was unsuccessful, no significant histologic changes were observed. CONCLUSION: In the year after successful H. pylori eradication, precancerous lesions improved in most patients.  相似文献   
80.
For the purpose of determining exercise intensity required for evaluating the effect of beta-blocking agents, the multi-stage treadmill exercise was carried out up to intensity of 85% of maximal oxygen intake (VO2max) after administration of beta-blocking agents in 7 healthy men. To obtain a stable dose response in the inhibitory effect of beta-blocking agents on heart rate (HR) and systolic blood pressure (S-BP), the exercise intensity more than 65% of VO2max (75% of maximal heart rate) was needed. In order to evaluate the effect of befunolol (BFE), a submaximal treadmill exercise of 75% of the age adjusted predicted maximal heart rate was loaded in 6 healthy men at 1.5, 4, and 8 hours following a single oral administration of 10 mg, 20 mg or 40 mg of BFE and 20 mg or 40 mg of propranolol. Simultaneously, the plasma concentration of BFE was determined 1.5, 4, 6 and 8 hours after the administration of BFE at each dose. In human serum, BFE was detected together with its metabolite, revealing a significant correlation between BFE and metabolite (r = 0.94, p < 0.001). Almost a certain rate of metabolite (4--5 times) was detected against BFE. As for the biological half life, it was 1.79 +/- 0.13 hours with BFE and 3.67 +/- 1.33 hours with metabolite. The inhibitory effect of BFE on HR and S-BP during exercise exhibited a dose response with the oral dose and its plasma concentration, and was almost twice as much as that of propranolol at the same dose. Accordingly, the myocardial oxygen consumption which may be represented as rate pressure product was inhibited twice as much as propranolol. BFE is characteristic of its more rapid elimination of its effect compared to the other beta-blocking agents. The decrease in the inhibitory effect of BFE or HR during exercise was about 1.8 times quicker than that of propranolol.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号