全文获取类型
收费全文 | 1113689篇 |
免费 | 76204篇 |
国内免费 | 1491篇 |
专业分类
耳鼻咽喉 | 15552篇 |
儿科学 | 35653篇 |
妇产科学 | 29090篇 |
基础医学 | 158393篇 |
口腔科学 | 30005篇 |
临床医学 | 99185篇 |
内科学 | 211736篇 |
皮肤病学 | 24834篇 |
神经病学 | 85456篇 |
特种医学 | 44541篇 |
外国民族医学 | 201篇 |
外科学 | 170842篇 |
综合类 | 22008篇 |
现状与发展 | 2篇 |
一般理论 | 315篇 |
预防医学 | 78082篇 |
眼科学 | 25267篇 |
药学 | 88633篇 |
7篇 | |
中国医学 | 2836篇 |
肿瘤学 | 68746篇 |
出版年
2021年 | 9342篇 |
2019年 | 9249篇 |
2018年 | 13130篇 |
2017年 | 10176篇 |
2016年 | 11411篇 |
2015年 | 12699篇 |
2014年 | 17276篇 |
2013年 | 24627篇 |
2012年 | 34418篇 |
2011年 | 36044篇 |
2010年 | 20940篇 |
2009年 | 19505篇 |
2008年 | 32612篇 |
2007年 | 34841篇 |
2006年 | 35024篇 |
2005年 | 33079篇 |
2004年 | 31548篇 |
2003年 | 30075篇 |
2002年 | 28859篇 |
2001年 | 60168篇 |
2000年 | 61593篇 |
1999年 | 51084篇 |
1998年 | 12680篇 |
1997年 | 11184篇 |
1996年 | 11150篇 |
1995年 | 10427篇 |
1994年 | 9436篇 |
1993年 | 8930篇 |
1992年 | 37844篇 |
1991年 | 36315篇 |
1990年 | 35778篇 |
1989年 | 34321篇 |
1988年 | 30900篇 |
1987年 | 30026篇 |
1986年 | 28245篇 |
1985年 | 26484篇 |
1984年 | 19218篇 |
1983年 | 16145篇 |
1982年 | 8860篇 |
1979年 | 17043篇 |
1978年 | 11421篇 |
1977年 | 10240篇 |
1976年 | 8849篇 |
1975年 | 10079篇 |
1974年 | 11668篇 |
1973年 | 11290篇 |
1972年 | 10768篇 |
1971年 | 10103篇 |
1970年 | 9261篇 |
1969年 | 8944篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
941.
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
942.
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
943.
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
944.
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
945.
L K Pickering 《American journal of public health》1986,76(6):623-624
946.
947.
K Satomi Y Kinoshita S Hirakawa 《Cortex; a journal devoted to the study of the nervous system and behavior》1991,27(2):327-331
If defective cross-localization of fingertips (CLF) in callosal patients is due to a deficit in the interhemispheric transfer of somesthetic information, when the patient's eyes are open, CLF should be affected when the stimulated hand is excluded from vision, not when the responding hand is excluded from vision. In order to investigate this hypothesis, a patient with a callosal lesion was subjected to CLF with eyes closed and open. With eyes closed, the CLF score in the left-to-right direction was significantly lower than that in the right-to-left direction. With eyes open, the CLF performance in the right-to-left direction was impaired when it was the responding hand to be excluded from vision, not when it was the stimulated hand to be excluded from vision. It would, therefore, appear that the patient's CLF disturbance was not due to a somesthetic transfer deficit, but to left unilateral apraxia for the right-to-left direction errors and to left tactile finger anomia for the left-to-right direction errors. 相似文献
948.
M G Bartels C K Varley J Mitchell S J Stamm 《Journal of the American Academy of Child and Adolescent Psychiatry》1991,30(1):100-103
Electrocardiograms were evaluated in 39 children and adolescents before and after the clinical use of imipramine and desipramine. The average increase in PR interval was 0.01 seconds. The PR interval increased by 0.02 seconds in 11 subjects, and a new first-degree atrioventricular block developed in two subjects. These changes were not related to the choice between imipramine and desipramine, the dose, or the method of administration. An increase in PR interval by 0.02 seconds or more did correlate with having an abnormality disclosed on a pretreatment electrocardiogram. The average increase in PR interval was 0.007 seconds for subjects with normal baseline electrocardiograms and 0.019 seconds for subjects with conduction and nonconduction abnormalities disclosed in baseline tracings. None of the electrocardiogram changes resulted in adverse clinical consequences. 相似文献
949.
A 67-year-old woman, who presented polyneuropathy, pleural effusion, ascites and sclerosing changes in the ribs, was admitted to our hospital on June 17, 1987. On admission, cerebrospinal examination showed a marked protein-cell dissociation and a delay in nerve conduction velocity. Bence-Jones protein was detected in urine, and the immunohistochemical study of biopsied bone marrow of the rib revealed lambda-chain positive plasmacytoma. Serum immunoelectrophoresis, however, showed no monoclonal gamma-globulinemia. From the findings described above, she was diagnosed as having Crow-Fukase syndrome associated with lambda-type light chain disease. Even with a therapy by prednisolone, platelet counts progressively declined to 10,000/ml3. Bone marrow aspiration showed normal number of megakaryocytes. Since platelet-associated IgG was increased to 452 ng/1.0 x 10(8) plt, a diagnosis of autoimmune thrombocytopenia was considered. Melphalan and cyclophosphamide to plasmacytoma resulted in a marked improvement of platelets. In addition, the level of platelet-associated IgG returned to normal range. Polyneuropathy, however, didn't respond to those therapies. It was suggested that both Crow-Fukase syndrome and thrombocytopenia were closely concerned with plasmacytoma but developed in a different manner. 相似文献
950.
W D Lovan R A Weaver R J Lentz J K Goodrum B F Withers 《Aviation, space, and environmental medicine》1986,57(4):370-375
The Naval Special Board of Flight Surgeons was established in 1956 for the evaluation of Navy, Marine Corps, and Coast Guard problem aeromedical cases. This paper examines a sample 248 of these cases for the period of 1974-83 with respect to the characteristics of those referred, their referral diagnostic category, and the recommendation of the Special Board regarding return to a flying status. Those cases with a referral diagnostic category of ENT and Ophthalmology were less likely to be returned to flight status. Older, more senior pilots, and pilots with more total flight time were less likely to be returned to unrestricted flying than were their younger, more junior, and less experienced counterparts. Otherwise, no significant difference in outcome based on age, rank, marital status, branch of service, specialty, or flight hours was detected. Overall, 61% of those evaluated by the SBFS were returned to flight status. 相似文献