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   2395426篇
  免费   200178篇
  国内免费   4307篇
耳鼻咽喉   34527篇
儿科学   73442篇
妇产科学   63405篇
基础医学   338546篇
口腔科学   67947篇
临床医学   218136篇
内科学   473176篇
皮肤病学   48475篇
神经病学   203308篇
特种医学   96868篇
外国民族医学   897篇
外科学   363906篇
综合类   56497篇
现状与发展   1篇
一般理论   1004篇
预防医学   192506篇
眼科学   55884篇
药学   179283篇
  4篇
中国医学   4440篇
肿瘤学   127659篇
  2018年   24987篇
  2017年   19437篇
  2016年   21267篇
  2015年   24014篇
  2014年   34543篇
  2013年   52058篇
  2012年   70624篇
  2011年   74216篇
  2010年   43649篇
  2009年   41807篇
  2008年   70282篇
  2007年   74698篇
  2006年   75579篇
  2005年   73431篇
  2004年   70676篇
  2003年   68128篇
  2002年   67290篇
  2001年   112773篇
  2000年   116851篇
  1999年   98684篇
  1998年   28097篇
  1997年   25707篇
  1996年   25633篇
  1995年   24769篇
  1994年   23292篇
  1993年   21659篇
  1992年   79555篇
  1991年   76568篇
  1990年   73723篇
  1989年   70979篇
  1988年   65988篇
  1987年   64932篇
  1986年   61499篇
  1985年   58559篇
  1984年   44339篇
  1983年   37759篇
  1982年   22965篇
  1981年   20405篇
  1979年   41424篇
  1978年   29084篇
  1977年   24433篇
  1976年   22898篇
  1975年   24031篇
  1974年   29716篇
  1973年   28118篇
  1972年   26302篇
  1971年   24214篇
  1970年   22792篇
  1969年   21118篇
  1968年   19173篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
In order to satisfy the need to restore the aesthetics, phonetics and comfort and to facilitate optimal hygiene procedures, 20 edentulous patients were treated with a new concept of overdenture therapy on implants ad modum Brånemark. After 24±3.5 months the patients were re‐examined. They were asked to answer a questionnaire and use a Visual Analogue Scale (VAS) to give their opinion on the prosthetic treatment. The results indicate that an implant‐retained overdenture in the maxilla with this design can satisfy the patients needs in aesthetics, phonetics and comfort and can 1 facilitate oral hygiene measures.  相似文献   
992.
Summary Two cases of documented HIV-1 transmission by needle stick and one case of probable transmission by eczematous lesion in three nurses in Germany are reported in the period 1988 to 1991. In two of the cases the nurse knew of the AIDS status of the index patient. A review of the three cases reiterates the importance of repeated training on the prevention of accident and on measures to be taken after an accident, as well as the need to keep the workplace free of additional burden when AIDS or HIV-infected patients are treated.
HIV-Übertragung durch Nadelstichverletzung und über offenes Ekzem. Drei Fälle aus Deutschland
Zusammenfassung Zwei dokumentierte HIV-Übertragungen über Nadelstichverletzung und eine Übertragung über ein offenes Hautekzem der Hand bei zwei Krankenschwestern und einem Pfleger aus den Jahren 1988 bis 1991 werden geschildert. Diese Übersicht der drei Fälle weist auf die Bedeutung von wiederholten Übungen hin, um einen Unfall zu verhüten und auf Maßnahmen die nach einem Unfall zu ergreifen sind. Unter anderem auf die Notwendigkeit den Arbeitsplatz von zusätzlichen Gegenständen freizuhalten, wenn AIDS- oder HIV-infizierte Patienten behandelt werden.
  相似文献   
993.
Results of arthroscopic acromioplasty related to rotator cuff lesions   总被引:1,自引:1,他引:0  
Summary Seventy-nine patients with a history of the subacromial impingement syndrome were treated by arthroscopic acromioplasty. The results were evaluated with a new scoring system designed to assess subjective symptoms before and after operation. The outcome was related to the pathological lesions of the rotator cuff seen at arthroscopy and graded by our modification of the Neer classification. The overall results were satisfactory in 67%, with men having better results than women. Those with a history of injury did better than those without, and the results in those with partial or total cuff tears were better than those with intact cuffs. Since the state of the cuff affects the result, arthroscopy should precede acromioplasty.
Résumé Soixante dix-neuf patients, présentant depuis 3.5 ans (±1.8) un syndrome de conflit sousacromial, ont été traités par acromioplastie arthroscopique. Les résultats ont été évalués au moyen d'une nouvelle cotation, mesurant la symptomatologie subjective avant et 17 mois en moyenne après l'intervention chirurgicale. On a étudié le rapport entre ces résultats et la morphologie pathologique de la coiffe des rotateurs, constatée lors de l'arthroscopie et classée conformément à notre version modifiée, décrite précédemment, de la classification de Neer. Les résultats globaux étaient satisfaisants dans 67% des cas. Les résultats étaient nettement meilleurs chez les hommes que chez les femmes. Ils étaient significativement meilleurs chez les patients pour qui la symptomatologie était apparue après un traumatisme violent, de même lorsqu'il existait une rupture totale ou partielle de la coiffe des rotateurs. L'état de la coiffe influence les résultats de l'acromioplastie, pour pouvoir le déterminer il faut pratiquer une arthroscopie préalable.
  相似文献   
994.
995.
The results of the in vitro fertilisation programme at Tygerberg Hospital for the period April 1983 to January 1988 are presented. Of the 1117 laparoscopies performed, 825 patients reached the transfer stage. A live-birth rate of 9.3% was achieved. The pregnancy rate after transfer of 4 embryos was 25.9% compared with 15.4% after 2 embryos and 10.8% after 3 embryos (P = less than 0.0001). The multiple pregnancy rate was 2.8% in the group receiving 2 embryos and 11.7% and 10.4% in those receiving 3 and 4 embryos, respectively. Of the 77 successful pregnancies (90 babies), 1 baby died at 34 weeks' gestation as the result of abruptio placentae due to preeclampsia and 1 cot death occurred. The only congenital abnormality encountered was a cleft palate.  相似文献   
996.
Despite a widely held belief that the use of emollients prior to broad-band UVB irradiation accelerates clearance of psoriasis, only one single-blind controlled study exists in support of this. No similar study has been carried out with photochemotherapy (PUVA) or narrow-band UVB (311–313 nm) phototherapy. As some emollients absorb UV radiation, and thereby inhibit psoriasis clearance, there is a need to identify emollients suitable for pre-irradiation use. Coconut oil may be useful in this respect. In two randomized groups of patients with chronic plaque psoriasis undergoing either routine PUVA(n=14) or narrow-band UVB phototherapy (n=15), a single-blind controlled (half-body) study was undertaken to assess the died of pre-irradiation application of coconut oil. Patients were given PUVA twice weekly, or TL-01 therapy thrice weekly. The initial UV dose was 70% of previously determined minimal phototoxic (MPD) or minimal erythema doses (MED), with 40% incremental steps at each visit (reduced if adverse effects occurred). Psoriasis severity was scored on each side after every three treatments. No significant acceleration of psoriasis clearance was seen in either group. We do not, therefore, recommend the routine use of emollients prior to PUVA or TL-01 therapy when using near erythemogenic irradiation regimens.  相似文献   
997.
Nine men with dural arteriovenous malformations (DAVM) at the base of the anterior cranial fossa are described. Four patients had intracerebral haemorrhage and four had seizures, associated with haemorrhage in two. In three cases the fistula was an incidental finding. In five cases the diagnosis could be made before angiography, on the basis of CT findings. Angiographically, venous drainage was always seen into ascending cortical veins. Five cases demonstrated drainage via the olfactory vein into the basal vein of Rosenthal; in four this way was the principal route of drainage. Five patients underwent surgery, the therapy of choice. One fistula closed spontaneously after angiography. Two patients refused treatment and one was not treated because of his poor general condition. Because arterial supply was usually bilateral, from small branches of the ophthalmic artery, embolisation seemed to be more dangerous. Compared to dural fistulae in other locations the DAVM of the anterior cranial fossa have a higher risk of complications and should be treated even if asymptomatic at the time of diagnosis.  相似文献   
998.
A technique is described for recording the electromyographic response of the striated urethral sphincter to transcutaneous magnetic stimulation of the brain and spinal cord. A series of 11 control patients have been studied and 3 examples of patients with neurological disease also are reported. The most reliable response was recorded after facilitated transcranial stimulation of the cerebral cortex, with the mean latency of the electromyographic response in the striated sphincter being 26.4 msec. (standard deviation 2.21). It is concluded that assessment of the latency of the striated urethral sphincter electromyographic response to transcranial magnetic stimulation may be a useful technique in the investigation of patients with disorders of micturition.  相似文献   
999.
G Nichol  A Nix  P J Barnes    K F Chung 《Thorax》1990,45(9):694-698
The effect of inhaled prostaglandin (PG) F2 alpha on the response to the inhaled tussive agent capsaicin was investigated in normal subjects. Seven subjects inhaled three breaths of four doses of capsaicin (0.3, 0.6, 1.2, and 2.4 nmol) before and immediately after inhaling PGF2 alpha (0.1 mumol) or placebo (0.15M NaCl) on separate days. The numbers of capsaicin induced coughs were greater after PGF2 alpha (mean 42.3 coughs) than after 0.15M sodium chloride (30.1). Visual analogue scores (0-10 on a 10 cm continuous scale) showed that capsaicin was more irritant after PGF2 alpha than after saline. Total respiratory resistance (Rrs), measured by the forced oscillation technique, was unaltered throughout the study. A double blind, placebo controlled study of the effects of inhaled salbutamol (200 micrograms, 0.6 mumol) and ipratropium bromide (40 micrograms, 0.1 mumol) on cough induced by capsaicin (2.4 nmol) and by PGF2 alpha (0.1 mumol) and on PGF2 alpha augmented, capsaicin induced coughing was performed in seven subjects. Neither drug had any effect on capsaicin induced coughing. Salbutamol reduced coughing due to PGF2 alpha (mean 7.7 coughs after salbutamol, 9.3 after placebo) but ipratropium bromide did not (mean 6.9 coughs after ipratropium bromide, 6.6 after placebo). Salbutamol also inhibited the augmentation of the capsaicin induced cough that followed inhalation of PGF2 alpha (mean augmentation 1.9 coughs after salbutamol, 4.1 after placebo), whereas ipratropium bromide did not (augmentation 1.7 coughs after ipratropium bromide, 2.7 after placebo). No changes in Rrs were seen after PGF2 alpha or either drug. Thus salbutamol reduces PGF2 alpha induced cough and the augmentation of capsaicin induced cough that follows PGF2 alpha.  相似文献   
1000.
The fate of skin allografts exchanged among heterozygous and homozygous gynogenetic common carp siblings, and among newly developed inbred strains and F1 hybrids, is described. Heterozygous gynogenetic offspring were produced by fertilizing eggs with UV-irradiated sperm and by treating the resulting zygote with a cold shock (0 degree C, 45 min). The temperature shock causes retention of the second polar body, which allows the eggs to develop into normal diploid fry. Homozygous gynogenetic offspring were similarly produced by using a heat shock (40 degrees C, 2 min), which suppresses the first mitotic division. Skin allografts exchanged among heterozygous gynogenetic carp exhibited prolonged survival, with some allografts (21.8%) surviving for over 28 days. Furthermore, a strong histocompatibility locus was seen to segregate in this group. In contrast, skin allografts exchanged among homozygous gynogenetic siblings were all rejected within 14 days (MST 9.4 days). New homozygous inbred strains, designated JJ and MM, were produced by gynogenetic reproduction of homozygous female carps, while F1 hybrids were produced by crossing of these homozygous females with homozygous male siblings. All grafts exchanged among members of the same strain were permanently accepted. Likewise grafts from homozygous strain members were accepted by fish from the related F1-hybrids, while the reverse grafts were rejected. These results provide evidence for the idea that in the carp histocompatibility genes exist at least one major locus and multiple minor loci, which are codominantly expressed.  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