全文获取类型
收费全文 | 3457613篇 |
免费 | 242655篇 |
国内免费 | 8856篇 |
专业分类
耳鼻咽喉 | 48123篇 |
儿科学 | 114649篇 |
妇产科学 | 96767篇 |
基础医学 | 489894篇 |
口腔科学 | 97060篇 |
临床医学 | 310724篇 |
内科学 | 673095篇 |
皮肤病学 | 81346篇 |
神经病学 | 281646篇 |
特种医学 | 134028篇 |
外国民族医学 | 1047篇 |
外科学 | 521024篇 |
综合类 | 69840篇 |
现状与发展 | 6篇 |
一般理论 | 1221篇 |
预防医学 | 262715篇 |
眼科学 | 78745篇 |
药学 | 254859篇 |
9篇 | |
中国医学 | 6887篇 |
肿瘤学 | 185439篇 |
出版年
2018年 | 37899篇 |
2017年 | 29101篇 |
2016年 | 33812篇 |
2015年 | 37618篇 |
2014年 | 51392篇 |
2013年 | 78162篇 |
2012年 | 104099篇 |
2011年 | 110778篇 |
2010年 | 66493篇 |
2009年 | 62858篇 |
2008年 | 104549篇 |
2007年 | 111572篇 |
2006年 | 113229篇 |
2005年 | 109045篇 |
2004年 | 105021篇 |
2003年 | 101812篇 |
2002年 | 98787篇 |
2001年 | 159855篇 |
2000年 | 164314篇 |
1999年 | 138362篇 |
1998年 | 40409篇 |
1997年 | 35811篇 |
1996年 | 35932篇 |
1995年 | 34537篇 |
1994年 | 31984篇 |
1993年 | 30033篇 |
1992年 | 108356篇 |
1991年 | 104975篇 |
1990年 | 102231篇 |
1989年 | 99062篇 |
1988年 | 91218篇 |
1987年 | 89582篇 |
1986年 | 84509篇 |
1985年 | 80900篇 |
1984年 | 60176篇 |
1983年 | 51693篇 |
1982年 | 30932篇 |
1981年 | 27480篇 |
1979年 | 54529篇 |
1978年 | 38541篇 |
1977年 | 33079篇 |
1976年 | 30813篇 |
1975年 | 33252篇 |
1974年 | 39096篇 |
1973年 | 37302篇 |
1972年 | 35330篇 |
1971年 | 32733篇 |
1970年 | 30546篇 |
1969年 | 29318篇 |
1968年 | 27186篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
951.
Clinical characteristics and surgical treatment of sporadic primary hyperparathyroidism with emphasis on chief cell hyperplasia 总被引:4,自引:0,他引:4
In 570 patients with sporadic primary hyperparathyroidism, the age, sex, symptoms, and preoperative serum calcium values were related to the histopathologic diagnoses, operative findings, and the extent and outcome of parathyroid surgery. Renal stone formation was especially prevalent in younger patients with slight hypercalcemia and parathyroid chief cell hyperplasia, whereas neuromuscular and psychiatric disturbances were overrepresented among older women with higher serum calcium values. Serum calcium concentration was inversely correlated to the proportional incidence of chief cell hyperplasia and positively correlated to the glandular weight of both adenomas and hyperplasias. Glandular size was markedly irregular in chief cell hyperplasia, with increased gland weights of no more than two glands in 78% of patients. During follow-up, for as long as 27 years, normocalcemia was obtained in 91% of patients with adenomas, with failures mainly depending on difficulties in identifying the parathyroid glands. The rate of normocalcemia was lower (80%) among patients with hyperplasia, but an inability to visualize the glands was not a major cause of failure. In patients with hyperplasia with asymmetric and more markedly enlarged glands, it appeared sufficient to remove only the enlarged glands, whereas the findings advocated a subtotal 3- to 3.5-gland resection in patients with more symmetrically or less enlarged hyperplastic glands. 相似文献
952.
D A Evans B N Hamid E M Hoare 《Journal of the Royal College of Surgeons of Edinburgh》1990,35(1):33-35
Thirteen cases of primary appendicular adenocarcinoma are reported. This rare tumour usually presents as acute appendicitis. The correct diagnosis is rarely entertained before or during surgery. The main treatment choice lies between appendicectomy alone and appendicectomy followed by right hemicolectomy. There are anatomical reasons for advising the latter and survival figures from the literature tend to support this preference. The cases reported here indicate that in the period 1972-1984, in the North West Region, there was a slight preference for appendicectomy alone. The additional procedure of right hemicolectomy did not confer any clear-cut survival advantage. 相似文献
953.
M L Schwartzman P Martasek A R Rios R D Levere K Solangi A I Goodman N G Abraham 《Kidney international》1990,37(1):94-99
Cytochrome P450-dependent arachidonic acid metabolism in human kidney cortex from several postmortem subjects has been characterized. Using HPLC and GC/MS, four cytochrome P450-arachidonic acid metabolites were tentatively but not unequivocally identified as epoxyeicosatrienoic acid (EET), dihydroxyeicosatrienoic acid (DHT) and 19- and 20-hydroxyeicosatetraenoic acids, suggesting the involvement of two major cytochrome P450 enzymes, epoxygenase and omega/omega-1 hydroxylases. This pattern of metabolism was similar to that found in rabbit and rat kidneys. The formation of these metabolites was dependent on the presence of NADPH and inhibited by IgG of NADPH-cytochrome P450 (c) reductase. Immunologic studies of renal cytochrome P450 epoxygenase demonstrated that antibodies prepared against human-purified hepatic cytochrome P450 epoxygenase recognized renal enzyme protein and inhibited the enzyme activity by 92%. In contrast, control immunoglobulin did not inhibit renal cytochrome P450 epoxygenase. Antibody inhibition of renal cytochrome P450 epoxygenase demonstrated a degree of conservation of both enzyme proteins between liver and kidney. Antibodies against lauric acid omega/omega-1 hydroxylases (P450 omega) inhibited the formation of omega/omega-1 hydroxylase products, 19- and 20-HETEs. Identical qualitative patterns of arachidonic acid metabolites were observed in all cortical microsomes studied. Interindividual variations were observed in the cytochrome P450-dependent arachidonic acid metabolism, and the activities ranged from 0.031 to 5.027 nmol arachidonic acid converted/mg protein/30 min. which is about a 150-fold difference. However, when the specific activities for total cytochrome P450-dependent arachidonic acid metabolism were calculated, two separate groups could be distinguished, high and low metabolizers of arachidonic acid.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
954.
1. Effects of a novel imidazoindole derivative on cholinergic function were studied in isolated tissue preparations. 2. The compound demonstrated a dose-dependent (10(-11)-10(-9) potentiation (20-60%) of acetylcholine induced tension in guinea pig ileal tissue. 3. Increases in the size of end-plate potentials and nerve evoked muscle twitches were observed in frog nerve-skeletal muscle preparations. 4. Cholinesterase activity was not inhibited. 5. The results suggest that the compound has actions at the post-synaptic muscarinic receptor complex in smooth muscle and causes pre-synaptic increases in ACh release at the neuromuscular junction. 相似文献
955.
Absorption mechanism and absorption site of a prodrug of L-DOPA, L-3-(3-hydroxy-4-pivaloyloxyphenyl)alanine (NB-355, 1) was investigated using rats. Prodrug 1 (0.5 mM) was taken up by intestinal tissue segments time-dependently in vitro at pH 6.0. However, the rate of uptake was less than that of L-dopa. Inhibitors of the amino acid active transport system (L-Phe, dinitrophenol, ouabain) had no effect on the uptake of prodrug 1. In the intestinal tissue segments, prodrug 1 was extensively hydrolyzed by diisopropylfluorophosphate-sensitive esterase(s). To characterize the absorption site, gastrointestinal tracts were ligated to make acute loops in situ and prodrug 1 or L-dopa was injected into the loops. L-dopa disappeared rapidly from the lumen of the jejunum. In contrast, prodrug 1 disappeared rapidly from the ileum rather than the duodenum or jejunum. From these results, it was suggested that prodrug 1 was slowly absorbed primarily from the lower small intestine. 相似文献
956.
Mortality prognostic factors in chest injury 总被引:2,自引:0,他引:2
1,026 multiple trauma patients (P) were compared to P with chest injuries (PCT) (407). Severity indices were related to type of thoracic injury and mortality. The Injury Severity Score (ISS), Glasgow Coma Scale (GCS), Trauma Score (TS), CHOP, and the Respiratory Index (RI) were used. The mortality rate of P was 27.1% but increased to 32.9% for PCT (p less than 0.05). We noted that mortality rate was highly dependent on major chest trauma: 68.6% for flail chest (FC), 56% for lung contusion (LC), 42.3% for hemothorax (HA), and 38.1% for pneumothorax (PN). ISS and RI scores for PCT survivors were greater than ISS + RI scores for P survivors (p less than 0.05 and p less than 0.01). ISS values for LC, HA, and PN PCT survivors were greater than the ISS of P survivors (p less than 0.01). Nonsurviving PCTs, especially those with lung contusion, showed a highly significant increase in ISS and RI scores. 相似文献
957.
We report a case of recurrent calculi in a Kock pouch continent urinary diversion. An open operation was avoided by successfully excising the Marlex mesh and removing it with the associated calculi in an endoscopic fashion. 相似文献
958.
M I Tikhilova 《Khirurgiia》1990,(8):63-66
The blood supply to the kidneys was studied in 106 children with urological diseases from angiograms. Computer analysis of 322 angiograms of patients with renal hypoplasia, dysplasia, hydronephrosis, megaureter, and abnormal mobility of the kidney was carried out. The results of angiography of a healthy kidney in 64 children were used to determine the normal parameters. The author gives a quantitative appraisal of the area of the kidney and its vessels, the calculation of the percentage of kidney vascularization, determination of the area of the renal cortex, the area of its vessels and percentage of vascularization, and the diameter of the large renal vessels. The study showed that the most informative parameters of the angiograms are as follows: the area of the renal vessels and its cortex, the percentage of vascularization of the Kidney and its cortex. Renal hypoplasia, dysplasia, megaureter, and hydronephrosis are characterized by different variants of disturbed blood supply of various severity. 相似文献
959.
960.
Studies were undertaken to determine if computed tomography (CT) could reliably assist physical examination in the initial assessment of blunt abdominal trauma, and also to examine how various abdominal injuries were managed with the guidance of CT. A total of 255 patients underwent emergency abdominal CT following blunt abdominal trauma over a period of seven years. One hundred and fifty two patients had abnormal CT scans, including 58 hepatic, 36 renal, 25 splenic and 9 pancreatic injuries as well as 67 patients with intra-abdominal hemorrhage and 21 patients with free abdominal air. A comparative study on the detection of pneumoperitoneum revealed CT to be far superior to plain radiography. One hundred and three patients had normal CT scans, all of whom were managed nonoperatively, except for three false-negative cases and two nontherapeutic cases. The patients with injury to the parenchymal organs were given nonoperative treatment if they had stable vital signs and no evidence of associated injuries demanding immediate surgery and the majority of these patients were managed well nonoperatively. CT was thus found to be a useful adjunct in the management of victims of blunt abdominal trauma, since in a rapid and noninvasive fashion, CT accurately defined the extent of parenchymal organ injury and also disclosed any other abdominal injuries. 相似文献