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   18589篇
  免费   1308篇
  国内免费   355篇
耳鼻咽喉   105篇
儿科学   585篇
妇产科学   307篇
基础医学   1544篇
口腔科学   537篇
临床医学   1696篇
内科学   2583篇
皮肤病学   194篇
神经病学   1478篇
特种医学   1420篇
外科学   1823篇
综合类   1501篇
现状与发展   1篇
一般理论   2篇
预防医学   3303篇
眼科学   207篇
药学   1436篇
  4篇
中国医学   240篇
肿瘤学   1286篇
  2024年   23篇
  2023年   285篇
  2022年   325篇
  2021年   561篇
  2020年   676篇
  2019年   673篇
  2018年   589篇
  2017年   627篇
  2016年   656篇
  2015年   586篇
  2014年   1154篇
  2013年   1319篇
  2012年   1048篇
  2011年   1128篇
  2010年   825篇
  2009年   863篇
  2008年   840篇
  2007年   930篇
  2006年   791篇
  2005年   804篇
  2004年   723篇
  2003年   684篇
  2002年   519篇
  2001年   408篇
  2000年   333篇
  1999年   299篇
  1998年   279篇
  1997年   217篇
  1996年   147篇
  1995年   204篇
  1994年   198篇
  1993年   168篇
  1992年   197篇
  1991年   159篇
  1990年   102篇
  1989年   102篇
  1988年   112篇
  1987年   82篇
  1986年   74篇
  1985年   110篇
  1984年   72篇
  1983年   53篇
  1982年   66篇
  1981年   51篇
  1980年   43篇
  1979年   25篇
  1978年   39篇
  1977年   31篇
  1976年   15篇
  1975年   11篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
51.
氟西汀与阿米替林治疗105例抑郁障碍病人的双盲对照试验   总被引:6,自引:4,他引:2  
目的:评价国产氟西汀的抗抑郁作用及安全性。方法:采用随机、双盲对照、多中心研究,分为国产氟西汀组57例(男性22例,女性35例;年龄40±s13a),口服氟西汀20mg,qd,阿米替林57例(男性27例,女性30例;年龄40±14a),口服阿米替林75mg,bid,疗程6wk。结果:氟西汀治疗抑郁障碍的疗效与阿米替林相当,总有效率分别为85%及92%(P>0.05);氟西汀组的主要副作用有口干、便秘、恶心、心动过速等,但较之阿米替林程度轻且发生率低。结论:氟西汀的抗抑郁作用与阿米替林相当,副作用少,服用方便。  相似文献   
52.
53.
This paper reviews evidence from clinical, epidemiologic, and family studies regarding the association between social phobia and other syndromes. Social phobia is strongly associated with other anxiety disorders, substance abuse, and affective disorders in both clinical and community samples. An average of 80% of social phobics identified in community samples meet diagnostic criteria for another lifetime condition. Social phobia is most strongly associated with other subtypes of anxiety disorders, with an average of 50% of social phobics in the community reporting a concomitant anxiety disorder including another phobic disorder, generalized anciety, or panic disorder. Approximately 20% of subjects in the community meet lifetime criteria for a major depressive disorder. The onset of social phobia generally precedes that of all other disorders, with the exception of simple phobia. Both clinical severity and treated prevalence are consistently greater among social phobics with comorbid disorders The results of family and twin studies reveal that shared etiologic factors explain a substantial proportion of the comorbidity between social phobia and depression, whereas the association between social phobia and alcoholism derives from a nonfamilial causal relationship between the two conditions. Clinical and phenomenologic implications of these findings are discussed.  相似文献   
54.
颈淋巴结清扫手术后乳糜漏的处理   总被引:10,自引:0,他引:10  
目的 :探讨颈淋巴结清扫手术后乳糜漏的处理方法。方法 :回顾分析颈淋巴结清扫手术 12 85例术后发生乳糜漏 2 1例的临床资料。结果 :乳糜漏的发生率为 1.6 % ,18例经保守治疗治愈 ,3例经再次手术治愈。结论 :对颈淋巴结清扫术后的乳糜漏应及早诊断 ,术中应加强预防并及时处理  相似文献   
55.
脊髓损伤的MR表现   总被引:9,自引:0,他引:9  
研究脊髓损伤的MR表现。采用GESigna0.5T超导型磁共振检查机,用脊柱表面线圈,对55例脊柱创伤病人做MR检查。所有病例做轮位和矢状位检查,用自旋回波序列和快速自旋回波序列。脊髓损伤表现为脊髓水肿23例次(41.8%),髓内出血10例次(18.1%),脊髓不完全性和完全性断裂7例次(12.7%),椎间盘值22例次(364%),脊柱韧带断裂30例次(545%)。脊髓损伤多见于爆裂型和骨折脱位型脊柱骨折。MR是脊髓损伤最有效的检查方法,MR对发现和评估脊髓损伤优于CT扫描。  相似文献   
56.
A retrospective study of arthroscopic meniscal repair in 101 consecutive patients was conducted. Sixty-three patients constituted our study group. The arthroscopic technique used for meniscal repair was the inside-out method using malleable cannulas. Forty-five patients were available for clinical examination, with a mean follow-up of 27 months. Tegner and Lysholm scores were comparable to those previously reported for arthroscopic meniscal repair. The HSQ (similar to the SF-36) scores were equal to those from an age- and sex-matched normal population, indicating that individuals with repaired menisci do not have any residual negative effects on global health at mean 26.9 months' follow-up. The physical functioning subscale of the HSQ was found to be sensitive to patient perception of results. Complications included one case of restricted knee range of motion requiring arthroscopy and lysis of adhesions. Overall clinical results were 64% excellent, 27% good, and 9% failure. Age, sex, and length of the meniscal tear had no affect on clinical outcome.  相似文献   
57.
探刊干性型老年黄斑变性(age-related macular deganeration,AMD)的病变发展特征并 寻找监测AMD病情进展的较敏感指标。 方法:用眼底彩色照相和眼底荧光血管造影(FFA)、明视视网膜电囤(ERG)、FM100-hue 色彩试验及视力检查,对60例(111眼)50~80岁、视力≤1.0的干性型AMD患者进行3~74个月(平均30.2个月)的随访观察。 结果:本组68眼经FFA检查、平均25.6个月随访,其中25%的患眼病灶损害有快慢不一的发展.全部111眼视力在平均30.2个月随访中有18%患眼的视力下降2行以下,且与病灶进展相符,FM100-hue 色彩试验的被随访者中,随访2年以后,其总错误分明显的增加(P<0.01).63眼的明视ERG在随访过程中无明显变化。 结论:大部分干性AMD患眼的病灶损害和视力可以在较长时间内维持稳定。FM100—hue的总错误分可能为监测AMD病情进展的较敏感指标. (中华眼底病杂志,1997,13:150-152)  相似文献   
58.
抗—HCV阳性单采浆供血员HGV感染随访研究   总被引:3,自引:0,他引:3  
为了解单采浆供血员庚型肝炎病毒(HGV)感染及其转归,对102名抗-HCV阳性单采浆供血员冻存血清进行抗-HGV和HGVRNA检测,对抗-HGV和(或)HGVRNA阳性者作3年随访研究。采用EIA法检测抗-HGV,包被抗原来自HGV不同功能区的合成肽。应用RT-PCR法检测HGVRNA,引物选自HGVNS3区。结果表明,抗-HCV阳性单采浆供血员HGVRNA阳性率为19.61%(20/102),抗-HGV阳性率为17.65%(18/102),HGV感染率(抗HGV和/或HGVRNA阳性)为24.51%(25/102),而对照组仅为0.94%(1/106)。提示单采血浆是HGV感染的重要危险因素。HGVRNA和抗-HGV的3年阴转率分别为35.00%(7/20)和11.11%(2/18),说明HGV感染有慢性携带趋势  相似文献   
59.
The effects of MPP+ (2.5–20 mg/kg) on the adrenal glands and heart were investigated in rats. At various periods after s.c. drug administration the rats were decapitated and tissue catecholamine levels were determined by means of HPLC with electrochemical detection. Adrenal dopamine (DA) levels were reduced at 2–8 h after MPP+ administration, but this decrease was followed by an elevation after 16 h and return to the control values after one week. Three successive injections of MPP+ caused a statistically significant elevation in adrenal DA, one day, with a tendency to elevation four and seven days after the last injection, whereas a severe (up to 96%) decrease in heart noradrenaline (NA) was found one day after the last injection. Seven days after the last injection a 50% depletion of NA in the heart was still observed. Pretreatment with GBR 12909 (30 mg/kg, 4 h) blocked the MPP+ (10 mg/kg, 2 h) induced reduction of adrenal DA levels, but at the same time GBR 12909 failed to block the effects of MPP+ in the heart. One day after three successive daily injections of MPP+ (10 mg/kg each), the DA-uptake inhibitor GBR 12909 (30 mg/kg, 6 h) could still induce an increase in adrenal DA.MPP+ appears to lack persistent cytotoxic action in the adrenal medulla but rather to cause a transient inhibition of DA synthesis followed by a compensatory stimulation. The inhibition can be blocked by specific inhibitor of the DA-uptake mechanism, suggesting a direct effect of MPP+ taken up by adrenomedullary cells. The data obtained so far do not suggest any involvement of peripheral dopaminergic nerves in the action of MPP+ on the adrenal medulla. The long-lasting depletion of the heart NA, however, suggests a lesion of peripheral noradrenergic nerves.Part of this work was presented at 6th International Symposium on Chromaffin Cell Biology, Marburg, Germany, 18–23 August 1991 Correspondence to: M. Kujacic at the above address  相似文献   
60.
Summary Unresectable solid tumors in the metastatic stage are quite resistant to current chemotherapy and radiation therapy regimens. Flavone acetic acid (FAA) is a novel antitumor agent which appears to work through a different mechanism than the conventional chemotherapeutic agents. In preclinical studies it has shown effectiveness against a variety of transplantable murine and human tumors and appears to be solid tumor selective. It also has non-overlapping toxicities as compared to conventional agents. We therefore investigated FAA in vitro against human colon cancer cells and explored whether its effectiveness could be enhanced in combination with other agents such as adriamycin (ADR), cis-platinum (CP) and difluoromethyornithine (DFMO) — an inhibitor of polyamine biosynthesis. Addition of FAA for 24 hours in liquid media produced dose dependent growth inhibition. Using soft agar colony assay, growth was inhibited by 58% by 3mM FAA and only 1.4% by 0.375mM FAA. The combination of FAA and cis-platinum produced synergism at the lower doses tested. The combination of FAA and adriamycin produced antagonism at all doses tested and the combination of FAA with DFMO did not produce results significantly different from DFMO alone. We conclude that enhancement of FAA activity can be achieved in combination with conventional antitumor agents, but may be drug and dose specific.  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