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   3217篇
  免费   179篇
  国内免费   29篇
耳鼻咽喉   29篇
儿科学   28篇
妇产科学   30篇
基础医学   418篇
口腔科学   49篇
临床医学   219篇
内科学   673篇
皮肤病学   53篇
神经病学   488篇
特种医学   105篇
外科学   403篇
综合类   9篇
预防医学   111篇
眼科学   102篇
药学   277篇
中国医学   42篇
肿瘤学   389篇
  2023年   29篇
  2022年   66篇
  2021年   100篇
  2020年   38篇
  2019年   53篇
  2018年   64篇
  2017年   43篇
  2016年   60篇
  2015年   57篇
  2014年   86篇
  2013年   108篇
  2012年   150篇
  2011年   164篇
  2010年   83篇
  2009年   67篇
  2008年   116篇
  2007年   149篇
  2006年   126篇
  2005年   152篇
  2004年   147篇
  2003年   145篇
  2002年   139篇
  2001年   138篇
  2000年   126篇
  1999年   98篇
  1998年   42篇
  1997年   35篇
  1996年   39篇
  1995年   24篇
  1994年   20篇
  1993年   17篇
  1992年   65篇
  1991年   68篇
  1990年   63篇
  1989年   59篇
  1988年   59篇
  1987年   56篇
  1986年   65篇
  1985年   54篇
  1984年   47篇
  1983年   40篇
  1982年   13篇
  1981年   10篇
  1980年   15篇
  1979年   19篇
  1978年   11篇
  1976年   11篇
  1973年   14篇
  1970年   11篇
  1969年   10篇
排序方式: 共有3425条查询结果,搜索用时 326 毫秒
31.
Ernst  R. D.  Sarai  P.  Nishino  T.  Collins  T.  Oto  A.  Hernandez  A.  Walser  E. M.  Chaljub  G. 《Journal of digital imaging》2003,16(4):337-340
For the benefit of the first-year gross anatomy students, we digitized and published on a Web site images that had been collected over a 30-year period. We provided a CD-ROM (compact disk, read-only media) containing the image set in higher quality format to students and faculty. We supplemented basic images with hot topics such as CT angiography, virtual colonography, computer-aided diagnosis, and 3D post-processing. Full motion video and moving JPEG (Joint Photo Expert Group) animations were integrated into the atlas. On the post course questionnaire medical students reported that the images on CD-ROM were helpful during the course and for review prior to examinations. Faculty and medical students used the CD-ROM for problem-based learning sections and facilitator training. The images were clear and easily projected during review sessions and were useful for the small group sessions, where they served as examples of normal anatomy.  相似文献   
32.
1. Extracellular single neuron activity was recorded in the lateral hypothalamic area (LHA) of awake, behaving monkeys, with particular regard to the feeding-related functional characteristics of glucose-sensitive (GS) versus glucose-insensitive (GIS) neurons. Firing rate changes were recorded by means of carbon fiber, multibarreled glass microelectrodes during 1) microelectrophoretic application of various chemicals, 2) gustatory and olfactory stimulation, and 3) a high fixed-ratio schedule (FR) bar press feeding task. 2. In 336 neurons examined, 91 (27%) were suppressed by electrophoretically administered glucose, and so they were designated as GS cells. The 245 neurons (73%) in which the firing rates did not change during glucose applications were pronounced GIS. The 179 GS and GIS cells tested exhibited different responses to the catecholamines (CAs), noradrenaline (NA) and dopamine (DA), both of which are intimately involved in the control of feeding. More GS neurons responded to NA than did GIS cells; the predominant effect of both CAs on GS neurons was inhibition. 3. The taste responsiveness of 111 LHA neurons was examined. Fifty-seven cells (52%) showed responses to gustatory stimulation. Of 50 GS neurons tested, 33 (66%) exhibited firing rate changes to tastes. On the contrary, only 24 (39%) of the 61 GIS neurons examined responded to gustatory stimuli. Activity changes of GS neurons commonly occurred to two or more tastants, in distinction to the relative gustatory specificity shown by GIS cells. 4. Two hundred fifty-six (84%) of the 303 neurons tested responded during one or more phases of the bar press feeding task. Most activity changes occurred during the bar press (BP) and reward (RW) periods, however numerous phasic responses to cue light (CL) and cue tone (CT) were also observed. A higher proportion of the GS neurons showed task-related activity changes than did the GIS cells (77, 95% and 179, 81%, respectively). GS neurons responded more during the BP phase and to the food reward; GIS cells were more responsive during the CL that enabled acquisition and the CT that signaled reward. Thus GS neurons were responsive during the acquisition and consumption of reward, whereas GIS cells responded to external cues signaling both of these events. The gustatory neurons displayed specific task-related activity changes only in the CL (GIS cells) and BP phases (GS neurons), that is, in phases most intimately involved in sensory-motor integration. 5. Two-thirds of the 30 GS neurons tested were responsive to both gustatory and olfactory stimulation as opposed to only one-third of GIS cells.(ABSTRACT TRUNCATED AT 400 WORDS)  相似文献   
33.
Hong SC  Leen-Kim  Park SA  Han JH  Lee SP  Lin L  Okun M  Nishino S  Mignot E 《Sleep》2002,25(4):440-444
STUDY OBJECTIVES: Very few studies have evaluated narcolepsy in Asian countries, outside of Japan. Our goal was to study narcolepsy at the genetic, clinical and pathophysiological level in Korea. DESIGN: Prospective study of consecutive patients and age matched controls. Clinical data ascertained from the Stanford Sleep Inventory, Polysomnography and MSLT data, as well as clinical notes. High resolution DRB1 and DQB1 typing in all subjects and studies of CSF hypocretin-1 was also evaluated in a subset of patients. PARTICIPANTS AND SETTING: 20 patients diagnosed at St. Vincent and Korea University Hospitals (Seoul, Korea). 21 Korean control subjects. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: For narcoleptic subjects, mean age was 28.2 years old and 45% were female. Mean BMI was 23.9+/-3.4 kg/m2, a significantly higher value than that expected in an age- and sex-matched sample (p<0.01). All patients had sleepiness and cataplexy while the prevalence of other symptoms ranged from 60-75%. All but 2 subjects were HLA-DR15 (DR2), DQB1*0602 positive (90%). This high DQB1*0602 percentage compared with 24% DQB1*0602 positivity in 21 control Koreans. Protective effects were observed for the DQB1*0601 and DRB1*0406 alleles, Hypocretin (orexin) CSF studies were also performed in 6 cataplectic subjects, all of which had undetectable CSF hypocretin levels. Two of these subjects had started narcolepsy less than 1 year before analysis yet had undetectable hypocretin levels. CONCLUSION: These results illustrate the similarity of narcolepsy-cataplexy in Korea in comparisons with other more studied populations. We also identified a new potential HLA protective subtype, HLA-DRB1*0406.  相似文献   
34.
Fucoxanthin (Fx) has preventive effect against muscle atrophy and myotube loss in vitro, but it has not yet been examined in vivo. Therefore, we aimed to investigate the effect of Fx on dexamethasone (Dex)-induced muscle atrophy and fat mass in mice. ICR mice were fed with Fx diets from 2 weeks before Dex treatment to the end of the study. Muscle atrophy was induced in the mice by oral administration of Dex. Body weight was significantly lower by Dex treatment. Visceral fat mass in the Fx-treated group were significantly lower than those in the control group. The Dex-induced decrease in tibialis anterior muscle mass was ameliorated by Fx treatment. Fx treatment significantly attenuated muscle lipid peroxidation compared with the control and Dex-treated groups. The phosphorylation of AMPK was significantly higher in the Dex-treated group than in the control group. The expression of cytochrome c oxidase (COX) IV was significantly higher in the Fx-treated group than in the control group. These results suggest that Fx may be a beneficial material to prevent muscle atrophy in vivo, in addition to the effect of fat loss.  相似文献   
35.
The threat of the current coronavirus disease pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is accelerating the development of potential vaccines. Candidate vaccines have been generated using existing technologies that have been applied for developing vaccines against other infectious diseases. Two new types of platforms, mRNA- and viral vector-based vaccines, have been gaining attention owing to the rapid advancement in their methodologies. In clinical trials, setting appropriate immunological endpoints plays a key role in evaluating the efficacy and safety of candidate vaccines. Updated information about immunological features from individuals who have or have not been exposed to SARS-CoV-2 continues to guide effective vaccine development strategies. This review highlights key strategies for generating candidate SARS-CoV-2 vaccines and considerations for vaccine development and clinical trials.  相似文献   
36.
Four monoclonal antibodies against human erythrocyte membrane antigens were established. The antigenic determinants of KOR-E1, E3, E6 were Pr1h antigen, Wrb antigen, and the trypsin sensitive portion of glycophorin A (EnaTS) respectively. The antigen recognized by KOR-E4 could not be determined. The reactivities of these antibodies with normal hematopoietic cells, malignant hematopoietic cell lines (N = 31), and fresh leukemic cells obtained from 128 patients with various types of leukemias were studied. All antibodies reacted only with erythrocytes among peripheral blood cells, and also KOR-E6 reacted only with erythroid cells among bone marrow cells. KOR-E3 had no reactivity with any cell lines examined, and KOR-E1 and KOR-E4 were reactive with some lymphoid cell lines. However, KOR-E6 had specific reactivities with erythroid (HEL, K562), megakaryocytic (CMK-1), multiphenotypic (KOPM-28), and basophilic (KU-812) cell lines. The antigen (glycophorin A) recognized by KOR-E6 was expressed on a small population of mononuclear cells separated from acute lymphoblastic leukemia (3/70), acute myelogenous leukemia (2/12), monosomy 7-myeloproliferative disorder (1/1), juvenile CML (1/1), and transient myeloproliferative disorder with Down's syndrome (4/12), although it could not be determined whether these cells were leukemic cells or not. KOR-E6 was reactive with a large population of leukemic blasts in erythroleukemia (2/2) and acute megakaryoblastic leukemia (3/6). Thus, KOR-E6 appears to be an erythroid marker of leukemic cells.  相似文献   
37.
Ide T  Sakurai Y  Aono M  Nishino T 《Anesthesiology》1999,90(4):1084-1091
BACKGROUND: The effects of inhalational anesthetics on the hypoxic ventilatory response are complex. This study was designed to determine the contribution of peripheral chemoreception to the depression of hypoxic ventilatory response seen with halothane anesthesia. METHODS: Cats were anesthetized with pentobarbital sodium and alpha-chloralose and artificially ventilated. Respiratory output was evaluated by phasic inspiratory activity of the phrenic nerve. In 12 cats, this activity was measured during inhalation of an hypoxic gas mixture with halothane, 0, 0.1, and 0.8%, with intact or denervated carotid bodies. In 10 cats, a carotid body was isolated from the systemic circulation and perfused with hypoxic Krebs-Ringer solution equilibrated with halothane, 0, 0.1, and 0.8%. RESULTS: The hypoxic ventilatory response was depressed in a dose-dependent manner during halothane anesthesia. In carotid body perfusion studies, the response was significantly depressed only with halothane, 0.80%. CONCLUSION: The hypoxic ventilatory response is depressed by a high dose of halothane through a peripheral effect at the carotid body.  相似文献   
38.
Honda K  Riehl J  Mignot E  Nishino S 《Neuroreport》1999,10(17):3717-3724
We have recently demonstrated that local perfusion of dopaminergic D2/D3 agonists into the ventral tegmental area (VTA) significantly aggravates cataplexy and increases sleep in narcoleptic Dobermans. We further assessed the roles of the mesostriatal dopaminergic system and found that local perfusion of quinpirole and 7-OH-DPAT into the substantia nigra (SN) significantly aggravated cataplexy, while perfusion of a D2/D3 antagonist significantly reduced cataplexy. Neither a D1 agonist nor a D1 antagonist modified cataplexy. SN perfusion of quinpirole did not significantly modify sleep, while VTA perfusion significantly increased the drowsy state. Although autoregulation of the VTA and SN dopaminergic neurons are involved in the regulation of cataplexy, both structures have distinct roles for the regulation of sleep.  相似文献   
39.
Müllerian duct cysts occupying the pelvic/abdominal region are rare. We describe a müllerian duct cyst extending into the lower abdomen in a 47-year-old man complaining of urinary retention. We removed the cyst through a suprapubic retrovesical approach. No malignancy was found in the surgical specimen.  相似文献   
40.
In order to elucidate temporal changes in airway reflex responses to prolonged tracheal intubation, 14 patients anaesthetized with sevoflurane were studied. In each spontaneously breathing patient with an endotracheal tube in place, the end-tidal concentration of sevoflurane was slowly decreased from the initial value of 1.3% until signs of airway irritation were observed. The value of end-tidal sevoflurane concentration at which the airway reflexes occurred (T(ar)) and the types of airway reflex response elicited at onset of airway reflex response were determined during the periods immediately before (presurgical period) and after surgery (post-surgical period), with an interval ranging from 2 to 7 h between the two periods. There was no significant difference in the values of T(ar) between the presurgical period (0.6 +/- 0.3%, mean +/- SD) and the post-surgical period (0.7 +/- 0.1%). There was a considerable difference in the type of airway reflexes elicited during the two different periods; the initial responses during the presurgical period were the apnoeic reflex and/or forceful expiratory efforts, whereas the initial response during the post-surgical period, in the majority of patients, was the swallowing reflex. Our results indicate that there may be adaptation mechanisms responsible for temporal changes in airway protective reflexes after prolonged endotracheal intubation in surgical patients.  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