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   7207篇
  免费   524篇
  国内免费   265篇
耳鼻咽喉   82篇
儿科学   149篇
妇产科学   49篇
基础医学   342篇
口腔科学   16篇
临床医学   739篇
内科学   627篇
皮肤病学   75篇
神经病学   887篇
特种医学   503篇
外科学   480篇
综合类   1249篇
预防医学   154篇
眼科学   1519篇
药学   637篇
  2篇
中国医学   377篇
肿瘤学   109篇
  2024年   27篇
  2023年   105篇
  2022年   205篇
  2021年   272篇
  2020年   257篇
  2019年   188篇
  2018年   221篇
  2017年   219篇
  2016年   262篇
  2015年   225篇
  2014年   410篇
  2013年   546篇
  2012年   408篇
  2011年   437篇
  2010年   343篇
  2009年   336篇
  2008年   394篇
  2007年   377篇
  2006年   372篇
  2005年   339篇
  2004年   231篇
  2003年   210篇
  2002年   159篇
  2001年   164篇
  2000年   144篇
  1999年   142篇
  1998年   100篇
  1997年   95篇
  1996年   76篇
  1995年   80篇
  1994年   73篇
  1993年   49篇
  1992年   59篇
  1991年   40篇
  1990年   38篇
  1989年   38篇
  1988年   43篇
  1987年   33篇
  1986年   23篇
  1985年   51篇
  1984年   45篇
  1983年   21篇
  1982年   28篇
  1981年   24篇
  1980年   21篇
  1979年   13篇
  1978年   20篇
  1977年   12篇
  1976年   5篇
  1975年   5篇
排序方式: 共有7996条查询结果,搜索用时 15 毫秒
21.
Summary The coagulation cascade has a potential role in brain edema formation due to intracerebral hemorrhage. In this study blood and other solutions were injected stereotactically into the right basal ganglia in rats. Twenty-four hours following injection, brain water and ion contents were measured to determine the amount of brain edema. Intracerebral blood resulted in an increase in brain water content. The amount of brain edema surrounding the intracerebral hematoma was reduced by a thrombin inhibitor Na-(2-Naphthalenesulfonylglycyl)-4-amidino-DL-phenylalaninepiperidide, (-NAPAP) infused into the hematoma after the clot had been allowed to solidify. The inhibitor did not alter the actual size of the clot mass. An artificial clot composed of fibrinogen, thrombin, and styrene microspheres also produced brain edema. A fibrin clot led to edema formation even in the absence of mass effect provided by the microspheres. The single component responsible for production of brain edema in all these models was thrombin. The edema was formed in response to a fibrinogen-independent pathway. These results indicate that the coagulation cascade is involved in brain edema that develops adjacent to an intracerebral hematoma.  相似文献   
22.
Summary The feline infusion model of brain edema was used to evaluate the pathophysiological effects of 0.6ml infusions of autologous serum protein (66%), human serum protein (66%), human glioma cyst fluid and a tissue culture medium (TCM) on the structure and function of the forebrain white matter. These infusions increased local white matter water content by between 10.8 and 12.5 ml/100 g brain and were associated with moderate increases in ICP and CSF outflow resistance and a significant decrease in lumped craniospinal compliance. Cortical somatosensory potentials, motor evoked potentials, EEG and local cerebral blood flow (rCBF) at normocapnia were generally unchanged by the various infusions. All infusates except the 66% autologous serum protein infusion impaired rCBF CO2 reactivity. Histologically all infusates caused marked extracellular edema. The autologous serum protein infusion caused no additional histological changes whereas the glioma cyst infusates caused profound endothelial and astrocytic swelling, focal endothelial necrosis, basement membrane disruption, perivascular microglial reaction and pavementation and perivascular migration of polymor-phonuclear leukocytes. Similar but less marked changes were seen after infusion of human serum protein whilst the TCM produced only minimal changes. The intensity and extent of Evans Blue extravasation into the forebrain white matter was greatest with glioma cyst infusates and with all infusions reflected the extent to microvascular changes.These studies show that products derived from gliomas cause additional damage to the blood-brain-barrier than that caused by non-autologous serum proteins. These results add further support for the existence of glioma derived permeability factors (GDPF), but suggest neither serum proteins nor glioma derived compounds in the white matter interstitium significantly influence local electrophysiological function. Some limitations of the infusion edema model when using non-autologous infusions and difficulties quantitating brain dysfunction are emphasised.Preliminary results had been presented at the symposium on Brain Edema VIII, which took place at Bern, Switzerland, in June 1990 and have been published in: Reulenet al (eds) 1990. Brain Edema VIII, Acta Neurochirurgica (Wien) [Suppl] 51: 71–73  相似文献   
23.
By comparing the incidence of cystoid macular edema (CME) in three groups of patients having different surgical procedures, we attempted to assess the role of vitreous loss as a risk factor for CME development. In the first group (n = 470), the surgical procedure was extracapsular cataract extraction followed by implantation of posterior chamber lens (EC-CE + PC-IOL). The second group (n = 42) had extracapsular cataract extraction which was complicated by posterior capsule rupture, and therefore anterior vitrectomy followed by implantation of anterior chamber lens had to be performed (ECCE + anterior vitrectomy + AC-IOL). In the third group (n = 22) the surgery was intracapsular cataract extraction followed by anterior chamber lens implantation (ICCE + AC-IOL). The third group was included in this follow up study to assess the role of AC-IOL as a possible causative factor for development of CME in uncomplicated cases of ICCE and AC-IOL. The difference of incidences of CME in the second and third group would therefore depend mostly on the vitreous loss. The incidence of CME diagnosed by fluorescein angiography in the first, second and third group was 1.5% (7/470), 35.7% (15/42) and 9.0% (2/22), respectively. All patients who developed CME were treated with combination of corticosteroid-antibiotic drops, dexamethasone retrobulbarly (40 mg/day) and peroral indomethacine (25 mg/day/6 weeks). This therapeutic regime resulted in only moderate improvement of visual acuity.Abbreviations AC-IOL anterior chamber intraocular lens - CME cystoid macular edema - ECCE extracapsular cataract extraction - ICCE intracapsular cataract extraction - IOL intraocular lens - PC-IOL posterior chamber intraocular lens  相似文献   
24.
BACKGROUND: In Asian countries, glycerol solution that contains fructose (5%) is often used for management of brain edema. However, glycerol and fructose may cause severe hypoglycemia and metabolic acidosis in patients with fructose-1,6-bisphosphatase (FBPase) deficiency, even under stable conditions. The aim of the present study was to determine whether glycerol solution was used for brain edema during acute metabolic decompensation of hypoglycemia and metabolic acidosis in patients with unrecognized FBPase deficiency in Japan and to examine a long-term prognosis of the patients who had this kind of severe metabolic decompensation with or without glycerol therapy. METHODS: A retrospective study of 20 children with FBPase deficiency was conducted, based on their medical records. RESULTS: Six of the 20 children were given glycerol solution for the presence or possibility of brain edema during acute metabolic decompensation of hypoglycemia and metabolic acidosis; two of the six patients administered with glycerol were given dialysis. In four patients treated with glycerol alone without dialysis, two had no brain edema before glycerol administration but it developed later after the administration. These four patients treated with glycerol alone died or developed severe neurological complications. Fourteen patients who were not treated with glycerol solution had no brain edema and showed good prognosis. CONCLUSIONS: Glycerol solution, which contains fructose in Asian countries including Japan, should not be used as an osmotic agent for treatment of brain edema in patients who have hypoglycemia and retention-type metabolic acidosis, until FBPase deficiency is ruled out by measuring blood concentration of lactate.  相似文献   
25.
We sometimes experience patients with persistent or progressive arytenoid edema, among which residual or recurrent cancer is often accompanied. Because it is difficult to distinguish tumour rest or recurrence from normal tissue sequelae in the early period after irradiation, it is important to know both the contributing factors for arytenoid edema, and the incidence of residual or recurrent tumours in patients with postirradiation laryngeal edema. We therefore reviewed the charts of 67 patients with early laryngeal carcinoma who had received a curative dose of irradiation in the last 5 years. Fourteen patients (20.9%) had moderate or severe laryngeal edema persisting for or developing at more than 3 months after completion of a course of definitive radiotherapy. The incidence was highest in supraglottic T2 disease, followed by glottic T2 tumour. Of the 14 patients with edema, six (42.9%) had persistent or recurrent disease. The primary disease was uncontrolled in 18 patients, 17 of whom received successful salvage surgery. In patients without residual tumours, the edema was usually moderate and resolved within a year, although four patients had chronic edema lasting more than a year after treatment. All four had supraglottic T2 lesions and received 70 Gy of X-ray. We also reviewed, for sake of comparison, the records of 38 patients treated with radiotherapy at doses of more than 40 Gy between l975 and 1980, when endoscopic microsurgery for laryngeal cancer was introduced as a primary part of treatment. The incidence of persistent or late developed edema over the period, though not significant, was 36.8%: nearly twice that of the last 5 years. Microscopic endolaryngeal surgical procedures seem to have been a causal factor for edema in this period.  相似文献   
26.
Changes in sodium, potassium, and water content in brain tissue are important in the progression of pathology that follows ischemic stroke. Determining these parameters regionally in rodent models of experimental ischemia has been limited because typical tissue weights of more than 35 mg are too large. Identifying ischemic tissue to direct tissue sampling towards ischemic cortex is also represents a difficult generally unresolved area. We suggest that larger differences between normal and ischemic cortex of sodium, potassium, and water content than previously observed can be obtained from directed sampling of 2-mg brain tissue in a model of focal cerebral ischemia. In five rats, the middle cerebral artery and both common carotid arteries were occluded for 4.9+/-0.13 h (mean+/-SEM). Punch-sampling of 1-mm diameter tissue cores for water content (H(2)O%) by the wet-dry method, and [Na(+)] and [K(+)] by flame photometry, was guided by the observation of a subtle change in the surface reflectivity of ischemic cortex of quickly dried, 20-microm frozen brain sections, that was confirmed by MAP2 immunohistochemistry. The ratio of the lesion areas as determined by the reflective change and MAP2 immunoreactivity was 0.96+/-0.03 (n=5). In ischemic cortex H(2)O% was 79.9%+/-0.8%, [Na(+)] was 550+/-25 mEq/kg dry-weight, and [K(+)] 94.2+/-19.2 mEq/kg dry-weight (n=5), all significantly different from the values in border zone cortex, and in cortex contralateral to ischemic cortex and border zone (for all samples n=60, mean wet weight 2.037+/-0.046 mg). Differences between ischemic and normal cortex were 5.4+/-1.1%, 317+/-21 mEq/kg dry-weight, -304+/-27 mEq/kg dry-weight (n=5) for H(2)O%, [Na(+)], and [K(+)]. These differences between ischemic and normal cortex are 1.4-2.5, 1-3.11, and 1.4-3.5 times greater, respectively, than previous results obtained using samples weighing 35 mg or more. These results extend the association of sodium and potassium with ischemic brain edema in the rodent model, and show that these classical measurements can keep pace with the regionality of histochemical and morphological methods.  相似文献   
27.
[目的]从缺血再灌注损伤的主要病理过程出发,研究了益肾补气活血法对脑缺血再灌注损伤的保护作用。[方法]用日龄62d的Wistar大鼠采用Warner方法做成脑缺血再灌注模型,平行观察假手术、盐水对照、益肾补气活血法对照3个组脑组织自由基和脑含水量的变化。[结果]益肾补气活血法中药组脑组织自由基和脑含水量明显低于盐水组。[结论]益肾补气活血法在一定程度上可以抑制自由基的产生及连锁反应的发生,促进神经细胞结构及功能的恢复,延缓神经细胞的坏死,具有治疗的多向性及疗效的准确性。  相似文献   
28.
感冒、水肿、便秘证治体会   总被引:1,自引:1,他引:1  
结合多年的临床实践,总结了对感冒、水肿和便秘等中医内科疾病的独特认识,并附病案佐证。  相似文献   
29.
目的探讨临床诊断以黄斑囊样水肿(cystoid macular edema,CME)为主要表现的糖尿病性视网膜病变患者的视野改变特征,为糖尿病性CME的诊断和预后判断提供依据。方法A组(无CME):32例(32只眼);B组(有CME):26例(26只眼)。采用重庆康华科技有限公司的(APS-6000B型)全自动电脑视野检查仪,测定参数:平均视敏度、视敏度标准差、平均缺损。同时测定糖化血红蛋白、血压和空腹血糖。结果A组患者平均视敏度、视敏度标准差、平均缺损三方面均高于B组,且统计学有显著性差异。糖尿病性CME患者的平均视敏度与空腹血糖无相关性,与糖化血红蛋白呈负相关,与血压呈负相关,与病程呈负相关。结论视野检查可作为糖尿病性CME的临床诊断方法之一。糖尿病性CME患者的视敏度变化受病程、糖化血红蛋白、血压的影响,而空腹血糖的影响不大。  相似文献   
30.
水肿因涉及病种较多,病情复杂,且复反复发作,治疗上有一定困难,以标本论,水湿留聚为其标,脏腑内虚为其本,根据邪正进退的不同情况,可分3个阶段辨证论治,邪气盛实阶段,以祛邪利水为主;邪实正虚阶段,宜利水扶正兼施,邪退正虚阶段,当扶正治本为主,探讨其证治规律,对于进一步提高疗效与减少复发,具有重要意义。  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