全文获取类型
收费全文 | 19686篇 |
免费 | 2033篇 |
国内免费 | 29篇 |
专业分类
耳鼻咽喉 | 166篇 |
儿科学 | 558篇 |
妇产科学 | 511篇 |
基础医学 | 2633篇 |
口腔科学 | 375篇 |
临床医学 | 2188篇 |
内科学 | 3988篇 |
皮肤病学 | 195篇 |
神经病学 | 2052篇 |
特种医学 | 953篇 |
外科学 | 2815篇 |
综合类 | 378篇 |
一般理论 | 14篇 |
预防医学 | 1868篇 |
眼科学 | 282篇 |
药学 | 1210篇 |
1篇 | |
中国医学 | 13篇 |
肿瘤学 | 1548篇 |
出版年
2021年 | 265篇 |
2020年 | 168篇 |
2019年 | 270篇 |
2018年 | 302篇 |
2017年 | 238篇 |
2016年 | 268篇 |
2015年 | 287篇 |
2014年 | 393篇 |
2013年 | 673篇 |
2012年 | 864篇 |
2011年 | 949篇 |
2010年 | 516篇 |
2009年 | 570篇 |
2008年 | 826篇 |
2007年 | 876篇 |
2006年 | 853篇 |
2005年 | 922篇 |
2004年 | 843篇 |
2003年 | 792篇 |
2002年 | 769篇 |
2001年 | 627篇 |
2000年 | 653篇 |
1999年 | 604篇 |
1998年 | 287篇 |
1997年 | 247篇 |
1996年 | 254篇 |
1995年 | 230篇 |
1994年 | 232篇 |
1993年 | 218篇 |
1992年 | 436篇 |
1991年 | 422篇 |
1990年 | 419篇 |
1989年 | 463篇 |
1988年 | 364篇 |
1987年 | 376篇 |
1986年 | 374篇 |
1985年 | 329篇 |
1984年 | 268篇 |
1983年 | 220篇 |
1982年 | 180篇 |
1981年 | 163篇 |
1980年 | 145篇 |
1979年 | 220篇 |
1978年 | 189篇 |
1977年 | 155篇 |
1976年 | 150篇 |
1974年 | 176篇 |
1973年 | 139篇 |
1972年 | 152篇 |
1971年 | 139篇 |
排序方式: 共有10000条查询结果,搜索用时 11 毫秒
91.
T Cundy J A Kanis G Heynen P J Morris D O Oliver 《The Quarterly journal of medicine》1983,52(205):67-78
Plasma calcium and albumin levels were measured serially in 100 patients for two years following successful renal transplantation. Mean plasma calcium increased during the first six months after grafting, in large part attributable to an increase in plasma albumin. The variance around the mean plasma calcium did not increase suggesting that mechanisms responsible for hypercalcaemia were common to the majority of patients. 36 per cent of patients developed hypercalcaemia within two years of grafting but the incidence fell to 11 per cent when more rigorous criteria for hypercalcaemia were used. The mechanisms maintaining plasma calcium were studied in 29 of the patients, nine of whom were hypercalcaemic and 20 of whom were normocalcaemic. Before transplantation, mean plasma calcium and phosphate levels were higher, the prevalence of subperiosteal erosions and extraskeletal calcification radiographically was greater, and the duration of haemodialysis treatment was longer in the hypercalcaemic patients than in the normocalcaemic recipients. At assessment after transplantation, hypercalcaemic patients had lower levels of plasma phosphate, higher plasma levels of alkaline phosphatase and parathyroid hormone, and higher hydroxyproline excretion. Renal function and 47Ca absorption were similar in the two groups. The major cause for apparent hypercalcaemia in transplanted patients appeared to be an increase in plasma albumin. In patients with true hypercalcaemia the major cause was pre-existing hyperparathyroidism where hypercalcaemia was mediated by increased renal tubular reabsorption of calcium. 相似文献
92.
Therapy for symptoms in the carcinoid syndrome 总被引:1,自引:0,他引:1
M Coupe S Levi M Ellis B Clarke J A Morris E A Alstead D J Allison H J Hodgson 《The Quarterly journal of medicine》1989,73(271):1021-1036
The clinical course and results of drug treatment for manifestations of the carcinoid syndrome are reviewed in 63 patients. The five-year actuarial survival in this group of patients was 48 per cent. The only markers of a poor prognosis that could be identified at diagnosis were marked weight loss and a high (over 1000 mumol/day) 5-hydroxyindole acetic acid excretion. The relative effectiveness of well-established drugs that either block 5-hydroxytryptamine synthesis or block 5-hydroxytryptamine receptors is reported, with respect to the different manifestations of the syndrome, and compared with a small group of patients treated with long-acting somatostatin analogue. In over one-third of patients, primary tumours were not detected on initial investigation, and in none of these did symptoms referrable to the primary site become apparent later. 相似文献
93.
L. Morris 《International review of psychiatry (Abingdon, England)》2013,25(5):347-354
This paper considers the perception of stress and its impact on social workers, their relationships and decision-making. It begins with an exploration of stress, perception and how perception is utilized to understand stress experiences. It continues with exploration of decision-making processes. Finally it explores themes relating to decision-making based on case study findings of social workers who experienced stress and explores the outcomes of decision-making in relation to the workplace and how this might impact on retention. 相似文献
94.
D M Gross C S Sweet E H Ulm E P Backlund A A Morris D Weitz D L Bohn H C Wenger T C Vassil C A Stone 《The Journal of pharmacology and experimental therapeutics》1981,216(3):552-557
The parent diacid (N-[(S)-1-carboxy-3-phenylpropyl]-L-Ala-L-Pro of MK-421 inhibited hog plasma angiotensin converting enzyme (ACE) by 50% (I50) at a concentration of 1.2 nM and was 17 times more potent than captopril. In vitro the I50 for MK-421, an ethyl ester, was 1200 nM because de-esterification did not occur. Similarly in the guinea-pig ileum, the diacid inhibitor and MK-421 potentiated the contractile effects of bradykinin at an AC50 of 77 pM and 18 nM, respectively. Inhibition of the pressor effects of angiotensin I by the diacid ACE inhibitor occurred at an ID50 of 8.2 micrograms/kg i.v. in rats and 6.4 micrograms/kg i.v. in dogs. Thus, the diacid was approximately 12 times more potent than captopril. The ID50 for MK-421 was 14 and 278 micrograms/kg i.v. in rats and dogs, respectively, because of differences in the rates of de-esterification. Oral ACE inhibitory activity was determined by blockade of the pressor effects of angiotensin I in conscious rats and dogs. In rats, but not in dogs, the diacid inhibitor was poorly absorbed, whereas MK-421 was well absorbed in both species. MK-421 inhibited the pressor effects of angiotensin I at 0.1 to 3.0 mg/kg p.o. for at least 6 hr in rats and dogs, and compared to captopril was 8.6 times more potent in rats and 4.6 times more potent in dogs. These data demonstrate that MK-421 and its parent diacid are potent, long-lasting orally active inhibitors of ACE. In addition, the low activity of MK-421 in vitro contrasts with its substantial in vivo activity, and supports the hypothesis that MK-421 is a prodrug that first must be de-esterified to permit full expression of its significant in vivo pharmacological activity. 相似文献
95.
Focus groups were held with home care case managers in two cities in Canada which provided information on the role of the case manager, factors that influence decision making, recent changes that have taken place in case management, and the different and positive aspects of home care case management. Factors which influence decision making were grouped into organizational, client, family, other professionals, and case management factors. The differences in case managers' preparation and functions in the two sites are discussed. The difficult aspects of case management included making tough decisions related to client resources, and client, work life, and management issues. The positive aspects included the personal interaction with clients, the opportunity to follow through on services to clients, the diversity of case management work, and the opportunity for relatively independent professional practice. 相似文献
96.
Acetyl glyceryl ether phosphorylcholine-stimulated human platelets cause pulmonary hypertension and edema in isolated rabbit lungs. Role of thromboxane A2. 总被引:12,自引:5,他引:12 下载免费PDF全文
J E Heffner S A Shoemaker E M Canham M Patel I F McMurtry H G Morris J E Repine 《The Journal of clinical investigation》1983,71(2):351-357
Macrophages, neutrophils, and platelets may play a role in acute edematous lung injury, such as that seen in the adult respiratory distress syndrome (ARDS), but their potential actions and interactions are unclear. Because stimulated human macrophages and neutrophils can release acetyl glyceryl ether phosphorylcholine (AGEPC), a potent platelet activator, we hypothesized that in ARDS, leukocyte release of AGEPC might stimulate platelets to release thromboxane A2 (TXA2), which then produces pulmonary hypertension and lung edema. In support of this premise, we found that pulmonary hypertension and edema occurred in isolated rabbit lungs perfused with human platelets and AGEPC, but not with platelets or AGEPC alone. Infusion of a vasodilator (nitroglycerin) to maintain base-line pulmonary artery pressures in lungs perfused with platelets and AGEPC prevented the development of lung edema suggesting that platelet and AGEPC-induced edema was hydrostatic in nature. Additional experiments suggested that the increased pressure was a result of TXA2 release from platelets stimulated by AGEPC. Specifically, preincubation of platelets with imidazole, a thromboxane synthetase blocker, prior to infusion with AGEPC significantly diminished pulmonary hypertension and prevented lung edema. Furthermore, pretreating lung preparations with 13-azaprostanoic acid, a TXA2 antagonist, before infusion of AGEPC and untreated platelets also reduced the pulmonary hypertension and blocked the lung edema. The role of TXA2 was further suggested when perfusates from lungs infused with platelets and AGEPC developed high levels of TXA2, whereas perfusates from controls did not. These results suggest that platelet aggregation induced by AGEPC may contribute to ARDS by releasing TXA2, which raises microvascular pressure and increases edema formation, especially when an underlying permeability defect is present. 相似文献
97.
David Jackson Morris Line Burholt Kristensen John Tøndering 《Clinical linguistics & phonetics》2013,27(12):1165-1183
Assessment of prosody perception may be useful in a number of clinical scenarios, including the rehabilitation of cochlear implant recipients. It is with this group in mind that we have derived and standardized a battery of tests that assess speech prosody perception in the Danish language. The prosodic contrasts included in the battery are vowel length, compounds and phrases, emotions, questions and statements, prominence and pronoun reference, all of which are commonly encountered in everyday communication. Lists of candidate stimuli were compiled and recorded by a representative speaker of Danish. All candidate stimuli were presented to normal hearing subjects (n = 12) in both unprocessed and 8-channel noise vocoded conditions. Subjects performed closed-set identification and the results were used to derive the final stimulus set. We report the results of the six subtests, in which we observed a bias to compounds in the compound/phrase subtest, and to statements in question/statement subtest. The pronoun reference subtest assessed the ability of a listener to infer a referent from the stress status of a pronoun, and we found high accuracy rates on this task indicating that it is suitable for inclusion in the battery. We discuss the possible uses of the Prosody in Use Battery in cochlear implant mapping and device verification. We also consider the role of the results from the test battery in guiding clinicians to material suitable for aural rehabilitation. 相似文献
98.
Extractable nuclear antigen effect on the DNA anti-DNA reaction and NZB/NZW mouse nephritis. 总被引:2,自引:0,他引:2 下载免费PDF全文
A D Morris C Littleton L C Corman J Esterly G C Sharp 《The Journal of clinical investigation》1975,55(5):903-907
Extractable nuclear antigen (ENA) is composed of at least two components, one a ribonucleo-protein sensitive to ribonuclease or heat and the other a protein. Antibodies to ENA are associated with a relatively benign clinical course in patients with systemic lupus erythematosus (SLE) in which DNA anti DNA complexes are thought pathogenic. The effect of ENA and anti-ENA on DNA anti-DNA reactions in vitro was studied. ENA effectively inhibited an anti-DNA hemagglutination reaction but no effect was found on binding of radioactive DNA or on the anti-hemocyanin hemagglutination reaction. The inhibitory effect was not abolished by yeast ribonuclease (RNase), heating, or DNase. Anti-ENA HAD NO EFFECT ON ANTI-DNA hemagglutination. In vivo, ENA altered the NZB/NZW mouse nephritis thought to be a model for human SLE nephritis. These results suggest the possiblity of a role for ENA in alteration of diseases due to pathogenic DNA anti-DNA complexes. 相似文献
99.
Eyal Zvi Shamir Stanley Morris Cassan Anat Levy Tova Lifshitz Ricardo Tarrasch 《Psychiatry research》2013
Since abnormalities in distal upper limb development are among the minor physical anomalies associated with schizophrenia we attempted to determine whether patients with schizophrenia can be identified on the basis of specific morphologic and dermatoglyphic features of the hand. Photographs and prints of the hands of 38 patients with schizophrenia and those of 42 control subjects were evaluated and graded on 13 biometric parameters. Results were statistically evaluated. A combination of three of the parameters was found to have good predicting abilities to distinguish between schizophrenics and controls. Subjects having high values in these three parameters were found to have a higher propensity to be defined as schizophrenics. In order to define a simple rule for classifying subjects we chose a criterion of having a value of 3 (in a scale from 1 to 3) in at least one of these three discriminating variables. This rule yielded an overall accuracy of 81.2%. Among controls, 85.7% of subjects did not fulfill such criteria, while 14.3% were defined as false positives. Among schizophrenics 76.3% achieved this condition while 23.7% were false negatives. The technique's objectivity and ease of application could facilitate the diagnosis of this disease. 相似文献
100.
Immunomodulation and blood transfusion 总被引:7,自引:0,他引:7
Blajchman MA 《American journal of therapeutics》2002,9(5):389-395
Over the past three decades, evidence from a variety of sources has suggested that allogeneic blood transfusions can induce clinically significant immunosuppression in recipients. This clinical syndrome is referred to in the transfusion medicine literature as transfusion-associated immunomodulation (TRIM) and has been linked to an improved clinical outcome in the setting of renal transplantation. Possible deleterious TRIM-associated effects include increased prevalence of cancer recurrence and postoperative bacterial infections. The recognition that TRIM can increase morbidity and mortality in allogeneically transfused individuals has become a major concern for those involved in transfusion medicine. Whether TRIM predisposes recipients to increased risk for cancer recurrence and/or bacterial infections is still not proven, however. In contrast to the available clinical data, studies in experimental animal models suggest that TRIM is an immunologically mediated biologic effect associated with the infusion of allogeneic leukocytes, which can be ameliorated by prestorage leukoreduction. Although considerable data have been accumulated in an attempt to unravel the clinically adverse effects of TRIM, the precise mechanism of TRIM has yet to be elucidated. Further studies, both basic and applied, to establish the clinically relevant manifestations of TRIM as well as the mechanism(s) are urgently required. 相似文献