全文获取类型
收费全文 | 2291401篇 |
免费 | 158476篇 |
国内免费 | 3487篇 |
专业分类
耳鼻咽喉 | 33459篇 |
儿科学 | 76826篇 |
妇产科学 | 61829篇 |
基础医学 | 324982篇 |
口腔科学 | 63028篇 |
临床医学 | 200272篇 |
内科学 | 444340篇 |
皮肤病学 | 52199篇 |
神经病学 | 179228篇 |
特种医学 | 92444篇 |
外国民族医学 | 879篇 |
外科学 | 351202篇 |
综合类 | 45818篇 |
现状与发展 | 2篇 |
一般理论 | 647篇 |
预防医学 | 164232篇 |
眼科学 | 52248篇 |
药学 | 175418篇 |
9篇 | |
中国医学 | 4943篇 |
肿瘤学 | 129359篇 |
出版年
2018年 | 24531篇 |
2017年 | 18930篇 |
2016年 | 21488篇 |
2015年 | 24179篇 |
2014年 | 32384篇 |
2013年 | 48611篇 |
2012年 | 67366篇 |
2011年 | 70642篇 |
2010年 | 42083篇 |
2009年 | 39127篇 |
2008年 | 66873篇 |
2007年 | 71954篇 |
2006年 | 72768篇 |
2005年 | 70957篇 |
2004年 | 68668篇 |
2003年 | 66427篇 |
2002年 | 64732篇 |
2001年 | 115086篇 |
2000年 | 118973篇 |
1999年 | 100363篇 |
1998年 | 26319篇 |
1997年 | 23499篇 |
1996年 | 23643篇 |
1995年 | 22195篇 |
1994年 | 20648篇 |
1993年 | 19306篇 |
1992年 | 76625篇 |
1991年 | 74206篇 |
1990年 | 72669篇 |
1989年 | 69558篇 |
1988年 | 63499篇 |
1987年 | 62174篇 |
1986年 | 58097篇 |
1985年 | 55334篇 |
1984年 | 40842篇 |
1983年 | 34337篇 |
1982年 | 19459篇 |
1981年 | 17488篇 |
1979年 | 36559篇 |
1978年 | 25057篇 |
1977年 | 21732篇 |
1976年 | 19645篇 |
1975年 | 21908篇 |
1974年 | 25427篇 |
1973年 | 24487篇 |
1972年 | 22994篇 |
1971年 | 21222篇 |
1970年 | 19839篇 |
1969年 | 18587篇 |
1968年 | 16766篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
951.
952.
The intensity and degree of heterogeneous epithelial marker expression were evaluated immunohistochemically in 29 mucosal biopsy specimens from 7 ulcerative colitis (UC) patients with dysplasia. Biopsy specimens from UC patients with mild (n = 7) or severe (n = 6) inflammation and from histologically normal samples (n = 7) served as controls. HLA-DR showed heterogeneous epithelial expression in all lesions with high grade dysplasia and in 6 of 8 with low grade dysplasia. SC was heterogeneous stained in 17 of 21 lesions with high grade dysplasia and in all but two lesions with low grade dysplasia. In histologically normal mucosa, SC was homogeneously expressed and epithelial DR was virtually absent. In mildly inflamed UC lesions, SC exhibited patchy distribution in only one sample and DR in two, whereas both SC and DR showed a slight degree of heterogeneous expression in all lesions with severe inflammation. Moreover, the overall intensity of SC staining tended to decrease with increasing degree of inflammation, whereas the opposite was seen for DR. Decreased SC and increased DR expression thus seemed to be related to intensified inflammatory activity, whereas heterogeneous expression of these markers was significantly more related to dysplasia. 相似文献
953.
R D'Angio R A Quercia N K Treiber J C McLaughlin J J Klimek 《JPEN. Journal of parenteral and enteral nutrition》1987,11(4):394-397
Total nutrient admixtures (TNAs) containing glucose, amino acids, and lipid emulsion in one container and amino acid/dextrose solutions [conventional total parenteral nutrition (TPN) formulations] were studied in a controlled laboratory experiment for their ability to support the growth of microorganisms. Both TNA and conventional TPN formulations for peripheral and central venous administration with standard additives were inoculated with microorganisms to provide 10(1)-10(2) colony-forming units/ml (CFU/ml) of Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Candida albicans. The admixtures were stored at room temperature and samples for quantitative microbiology were taken at time 0, 6, 12, 24, 48, 72, and 96 hr. K. pneumoniae, E. coli, and P. aeruginosa were able to proliferate in central TNAs, but the growth of these organisms was retarded in conventional TPN solutions. In the peripheral formulations, K. pneumoniae and E. coli proliferated in both the TNA and conventional TPN systems, whereas P. aeruginosa grew well only in the peripheral TNA. S. epidermidis was not able to grow in any admixtures tested; however, C. albicans grew well in all admixtures, but growth was slower in the conventional central TPN. In conclusion, peripheral and central TNAs supported the growth of microorganisms significantly better than conventional TPN solutions. 相似文献
954.
Intrathecal morphine for post-thoracotomy pain 总被引:1,自引:0,他引:1
We wished to investigate possible differences in the duration of postoperative analgesia and the incidence of respiratory depression after the intrathecal injection in the lumbar area of 10 micrograms/kg morphine in hypobaric and hyperbaric solution for relief of post-thoracotomy pain. Twenty-nine patients received morphine plus dextrose (hyperbaric) and 21 received morphine in preservative-free normal saline. The duration of analgesia was longer with the morphine in the normal saline group than in the hyperbaric group (P less than 0.04). One patient developed delayed respiratory depression. Our data support the use of morphine in normal saline mixtures for greater duration of analgesia after thoracic operations. 相似文献
955.
Intubating conditions after vecuronium and atracurium given in divided doses (the priming technique)
R. K. Mirakhur G. G. La Very F. M. Gibson R. S. J. Clarke 《Acta anaesthesiologica Scandinavica》1986,30(5):347-350
Intubating conditions have been assessed at 60 s following administration of vecuronium 0.1 mg kg-1 or atracurium 0.5 mg kg-1 given either as a single dose after induction of anaesthesia with thiopentone or in divided doses; vecuronium 0.015 mg kg-1 followed 4 or 6 min later by 0.085 mg kg-1, or atracurium 0.075 mg kg-1 followed 4 or 6 min later by 0.425 mg kg-1. In the divided dose groups the smaller initial (priming) dose was given prior to induction of anaesthesia. Onset and duration of clinical relaxation were assessed using a peripheral nerve stimulator. The intubating conditions at 60 s improved significantly, with the use of relaxants in divided doses being acceptable in 80 and 70% of patients, respectively, with vecuronium and atracurium, but the conditions are not as good as those commonly found using suxamethonium. Priming at 6 min has no advantage over priming at 4 min. The onset of complete block was accelerated with priming, but the difference was not significant. The duration of clinical relaxation of vecuronium was significantly prolonged by giving it in divided doses. Unpleasant awareness of muscle weakness was observed in 15 patients, requiring early induction of anaesthesia in five of them. 相似文献
956.
957.
Do-not-resuscitate orders for critically ill patients in the hospital. How are they used and what is their impact? 总被引:9,自引:0,他引:9
We studied compliance with do-not-resuscitate (DNR) orders at a university hospital where a DNR protocol has existed since 1979. Documentation of DNR status in patient progress notes and chart orders increased through 1983. During a 12-month period (March 1983 through April 1984), we studied in detail the medical records of 521 patients who had a cardiopulmonary arrest in the hospital. Seventy-five percent (389 of 521) of these patients were designated DNR. Patients who were designated DNR were significantly more likely to be older, to have malignancy or an abnormal mental status, and to be less likely to have acute myocardial infarction, stroke, or chronic obstructive pulmonary disease than patients in whom resuscitation was attempted. Eighty-six percent of families, but only 22% of patients, were involved in the decision to designate a patient DNR. The decision to designate a patient DNR occurred late in the course of a patient's illness, often when the patient was in coma. For 28% of patients, some form of medical care was withdrawn or withheld after they were designated DNR. These data suggest that use of the DNR protocol requires changes if patients are to participate in the decision not to undergo cardiopulmonary resuscitation. 相似文献
958.
959.
Apramycin and gentamicin resistance in Escherichia coli and salmonellas isolated from farm animals 总被引:2,自引:0,他引:2
Since the aminoglycoside antibiotic apramycin was licensed for veterinary use in 1980, all isolates of Escherichia coli and salmonellas received at the Central Veterinary Laboratory have been monitored for resistance to apramycin and the related antibiotic gentamicin. During the period 1982-4, the incidence of resistance in E. coli to apramycin increased from 0.6% in 1982 to 2.6% in 1984. In salmonellas the incidence of resistance to apramycin increased from 0.1% in 1982 to 1.4% in 1984. Resistance to both apramycin and gentamicin was detected in six different salmonella serotypes, although an isolate of Salmonella thompson from poultry was resistant to gentamicin but not apramycin. Most of the cultures were isolated from pigs, although the incidence of apramycin resistance in S. typhimurium (DT 204C) from calves has shown a recent dramatic increase. All the isolates with one exception produced the enzyme aminoglycoside 3-N-acetyltransferase IV (ACC(3)IV). The resistance was transferable by conjugation in most of the strains examined, and the plasmids specifying the resistance have been found to belong to a number of different incompatibility groups. Plasmids from three E. coli strains were compatible with all the reference plasmids and belonged to a previously undescribed group which was investigated further. It is suggested that bacteria from humans should be examined for resistance to apramycin and gentamicin to determine the possibility of the antibiotic-resistance bacteria, and their genes, spreading from animals to humans. 相似文献
960.
P. Breuer und S. Schwade 《Langenbeck's archives of surgery / Deutsche Gesellschaft fur Chirurgie》1986,369(1):809
Zusammenfassung 103 Patienten wurden wegen akuter spontaner oder nach Trauma persistierender Scrotalschmerzen behandelt. 62mal wurde diagnostisch freigelegt. Die intraoperativen Befunde (32 Torsionen, 12 stielgedrehte Hydatiden, 3 Hodennekrosen, 3 Hodenrupturen, 7 komprimierende Haematome, 5 Epididymitiden) bestätigten unsere Indikationsstellung zur chirurgischen Exploration: Plötzlicher Spontanschmerz, vor allem beim jugendlichen Patienten, anhaltender Schmerz nach Hodenprellung und alle Zweifelsfälle! Ohne Alternative spart der komplikationslose und schnelle diagnostisch-chirurgische Eingriff Zeit für das gefährdete Organ bei simultaner Therapiemöglichkeit. 相似文献