首页 | 官方网站   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   2381650篇
  免费   198895篇
  国内免费   4253篇
医药卫生   2584798篇
  2018年   24473篇
  2017年   18999篇
  2016年   20865篇
  2015年   23656篇
  2014年   33980篇
  2013年   51453篇
  2012年   69688篇
  2011年   73196篇
  2010年   43102篇
  2009年   41473篇
  2008年   69613篇
  2007年   73984篇
  2006年   74862篇
  2005年   72861篇
  2004年   70094篇
  2003年   67709篇
  2002年   66971篇
  2001年   112707篇
  2000年   116757篇
  1999年   98580篇
  1998年   28019篇
  1997年   25657篇
  1996年   25553篇
  1995年   24692篇
  1994年   23234篇
  1993年   21636篇
  1992年   79482篇
  1991年   76497篇
  1990年   73648篇
  1989年   70931篇
  1988年   65925篇
  1987年   64878篇
  1986年   61409篇
  1985年   58468篇
  1984年   44211篇
  1983年   37593篇
  1982年   22847篇
  1981年   20270篇
  1979年   41265篇
  1978年   28952篇
  1977年   24281篇
  1976年   22790篇
  1975年   23961篇
  1974年   29632篇
  1973年   28049篇
  1972年   26244篇
  1971年   24180篇
  1970年   22755篇
  1969年   21098篇
  1968年   19149篇
排序方式: 共有10000条查询结果,搜索用时 125 毫秒
991.
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   
992.
993.
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   
994.
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   
995.
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   
996.
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   
997.
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   
998.
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   
999.
The current experience of a high dependency unit established 5 years ago for the postoperative care of high-risk patients undergoing surgery is reported. The resource implications and contributions to the safety and quality of post-operative care, particularly pain relief, are described.  相似文献   
1000.
We retrospectively reviewed our experience with immediate breast reconstruction in 103 consecutive patients with stage 0 or I breast carcinoma between May 1983 and April 1988. Two reconstructive techniques were used, that is, either tissue expansion with secondary prosthesis implantation (60%) or transverse rectus abdominis musculocutaneous (TRAM) flap (40%). Chemotherapy was administered in 22% of patients without delay or compromise. The mean length of follow-up is 30 months. The complication rate was equal for both groups (24%) with infection being most common in the group of patients with tissue expansion and partial flap necrosis being most common in the group of patients with TRAM flaps. Aesthetic results were superior with use of the TRAM flap. Our experience concurs with previous reports that documented satisfactory results with immediate breast reconstruction without compromising further therapy. We conclude that although the tissue expansion technique yields acceptable results, the TRAM flap yields superior aesthetic results in terms of both appearance and consistency.  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-23

京公网安备 11010802026262号