全文获取类型
收费全文 | 6691篇 |
免费 | 724篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 48篇 |
儿科学 | 199篇 |
妇产科学 | 209篇 |
基础医学 | 1134篇 |
口腔科学 | 312篇 |
临床医学 | 598篇 |
内科学 | 1257篇 |
皮肤病学 | 67篇 |
神经病学 | 732篇 |
特种医学 | 164篇 |
外科学 | 931篇 |
综合类 | 147篇 |
一般理论 | 5篇 |
预防医学 | 696篇 |
眼科学 | 71篇 |
药学 | 487篇 |
肿瘤学 | 366篇 |
出版年
2021年 | 86篇 |
2020年 | 61篇 |
2019年 | 67篇 |
2018年 | 97篇 |
2017年 | 71篇 |
2016年 | 78篇 |
2015年 | 87篇 |
2014年 | 153篇 |
2013年 | 189篇 |
2012年 | 329篇 |
2011年 | 351篇 |
2010年 | 173篇 |
2009年 | 165篇 |
2008年 | 284篇 |
2007年 | 304篇 |
2006年 | 257篇 |
2005年 | 266篇 |
2004年 | 262篇 |
2003年 | 231篇 |
2002年 | 246篇 |
2001年 | 244篇 |
2000年 | 230篇 |
1999年 | 183篇 |
1998年 | 69篇 |
1997年 | 61篇 |
1996年 | 54篇 |
1995年 | 69篇 |
1994年 | 69篇 |
1993年 | 74篇 |
1992年 | 167篇 |
1991年 | 192篇 |
1990年 | 133篇 |
1989年 | 148篇 |
1988年 | 149篇 |
1987年 | 145篇 |
1986年 | 145篇 |
1985年 | 141篇 |
1984年 | 122篇 |
1983年 | 86篇 |
1982年 | 70篇 |
1981年 | 66篇 |
1980年 | 56篇 |
1979年 | 110篇 |
1978年 | 76篇 |
1977年 | 54篇 |
1975年 | 59篇 |
1974年 | 78篇 |
1973年 | 64篇 |
1972年 | 58篇 |
1970年 | 51篇 |
排序方式: 共有7423条查询结果,搜索用时 15 毫秒
81.
M R Matthews D M Caruso R B Tsujimura J D Smilack B A Pockaj J M Malone 《The American surgeon》1999,65(11):1035-1037
We report the occurrence of a refractory infection caused by the "rapidly growing" nontuberculous mycobacterium, Mycobacterium fortuitum, after incisional hernia repair using synthetic mesh. The patient had previously undergone three herniorrhaphies incorporating polypropylene mesh. Multiple surgical debridements were required, along with complete removal of all the mesh, to eradicate the infection. Prolonged antimicrobial therapy with sulfamethoxazole, an agent active against the patient's isolate, was also used. Although this atypical mycobacterium has been reported to cause a variety of infections, including many types of periprosthetic infections, this case represents successful treatment of M. fortuitum infecting abdominal wall mesh. 相似文献
82.
83.
Avissar S Schreiber G Nechamkin Y Neuhaus I Lam GK Schwartz P Turner E Matthews J Naim S Rosenthal NE 《Archives of general psychiatry》1999,56(2):178-183
BACKGROUND: Information-transducing heterotrimeric G proteins have been implicated previously in the mechanism of action of mood stabilizers and in the pathophysiology of mood disorders. Mononuclear leukocytes of patients with unipolar and bipolar depression have been characterized by reduced measures of the stimulatory and inhibitory G proteins. In this study, patients with seasonal affective disorder (SAD) were measured for mononuclear leukocyte G protein levels while depressed during the winter, following light therapy, and in remission during the summer. METHODS: Twenty-six patients with SAD and 28 healthy subjects were assessed in the study. The immunoreactivities of Gs alpha, Gi alpha, and Gbeta subunit proteins were determined by Western blot analysis of mononuclear leukocyte membranes with selective polyclonal antibodies for the various G subunit proteins, followed by densitometric quantitation using an image analysis system. RESULTS: Untreated patients with SAD and winter, atypical-type depression showed significantly reduced mononuclear leukocyte immunoreactive levels of Gs alpha and Gi alpha proteins, similar to previous observations in patients with nonseasonal major depression. The reduced G protein levels were normalized with 2 weeks of light therapy. The same patients while in remission during the summer had G protein levels that were similar to those of healthy subjects. CONCLUSIONS: G protein-immunoreactive measures in patients with SAD are suggested as a state marker for winter depression, which is normalized by light treatment and during the summer. We speculate that light may exert its effects via normalization of transducin (Gt protein) levels, which are thought to be reduced in winter depression. 相似文献
84.
Falloon IR McGill CW Matthews SM Keith SJ Schooler NR 《The Journal of psychotherapy practice and research》1996,5(1):45-56
The NIMH Treatment Strategies in Schizophrenia (TSS) collaborative study group investigated the efficacy of antisychotic drug maintenance strategies involving reduced medication exposure in interaction with applied and supportive family management for the long-term treatment of schizophrenia. Therapy was provided at five centers by 25 clinicians who did not participate in the development of the therapies. They were trained by two of the authors, I.R.H.F and C.W.M, in applied family management, a homebased treatment derived from the behavioral family therapy developed by them. Clinicians' characteristics, selection, and training methods, as well as patient rehospitalization rates, are reported for the two family management conditions. The TSS study represents a bridge between the development of a novel therapy and its dissemination in general clinical practice. 相似文献
85.
Janine M. Matthews Patrick H.J. Falckh Peter Molenaar Roger J. Summers 《Naunyn-Schmiedeberg's archives of pharmacology》1996,353(2):213-225
Regulation of -adrenoceptor (-ar) subtypes and transregulation of muscarinic cholinoceptors (mAchr) was examined in regions of rat heart after chronic infusion of (–)-isoprenaline (450 /kg per hour) for 14 days. Following (–)-isoprenaline infusion systolic blood pressure was reduced for 10 days but then gradually returned to control levels, whereas heart rate was increased for 7 days before declining to a level significantly above control. Heart weight to body weight ratio was increased in (–)-isoprenaline treated rats. -ar subtype densities were measured by quantitative autoradiography with [125I]-cyanopindolol (CYP) in sinoatrial node (SA), atrioventricular node (AV), bundle of His (BH), left (LB) and right (RB) bundle branches, interventricular (IVS) and interatrial (IAS) septa, right atria (RA), apex (AX) and mitral valve (MV). 1-ars were reduced by 59.1–74.2% in the AV conducting regions, 53.4% in the SA node and 43.3–53.4% in myocardial areas. 2-ars were markedly reduced in myocardial regions (93.2–98.5%) and in pacemaker and conducting regions (87.7–97.8%). No changes in mAchr densities measured using [3H]-N-methyl scopolamine (NMS) occurred in the AV node, BH, LB, RB, IVS and IAS following (–)-isoprenaline infusion.Densities of 1- and 2-ars and mAchrs were also measured in ventricular homogenates from control and (–)-isoprenaline treated animals. -ar levels were significantly reduced (P < 0.05) in treated animals and the ratio of 1- to 2-ars increased after treatment. mAchr density in ventricular homogenates measured using either [3H]-NMS or [3H]-quinuclidinyl [phenyl-4-3H]benzilate (QNB) was unchanged. Homogenates of left and right ventricle also showed no change using [3H]-NMS.Organ bath studies were used to investigate the effect of (–)-isoprenaline infusion on negative inotropic and chronotropic effects of the non-selective muscarinic receptor agonist bethanechol in left and right atria, respectively. Lower concentrations of bethanechol (3 × 10–10 to 10–6 M) produced a negative inotropic response in isolated electrically driven left atria from (–)-isoprenaline treated rats, but not from control rats, with the slope of the curves being significantly different between groups (ANCOVA, P = 0.037). At concentrations of bethanechol from 10–6 to 3 × 10–4 M the negative inotropic response was not changed between (–)-isoprenaline treated and control animals. Bethanechol also produced a negative chronotropic response at lower concentrations (10–10 to 10–6 M) in (–)-isoprenaline treated rats, but not in controls. A second, steeper phase of the negative chronotropic response occurred at concentrations of bethanechol greater than 10–6 M and was also seen in control rats.Expression of M2 (cardiac) mAchrs (m2Achr) in left and right ventricular tissues measured using a quantitative non-competitive polymerase chain reaction (PCR) assay showed a significant (P = 0.001) 28.5% increase in expression in left ventricle and a significant (P = 0.003) 21.5% decrease in expression in right ventricle after (–)-isoprenaline treatment, compared to controls. There was no significant difference in total ventricular m2Achr expression between the two groups of rats. The results suggest that chronic -ar stimulation down-regulates both 1- and 2-ars, and appears to differentially transregulate m2Achr expression, but not mAchr protein. Following (–)-isoprenaline infusion, muscarinic receptor mediated responses were sensitised, with no change in receptor densities, suggesting changes occur in the cell signalling system beyond the level of the receptor. 相似文献
86.
87.
Aspects of residential units provided for children under the Sheffield Development Project were studied. A variety of issues were raised which could be helpful in planning future services. The demand for places was considerably less than had been expected under the Project plans, and a greater than predicted proportion of the children had severe handicaps. Units had not specialized as intended, but had developed their own admission criteria. All unit heads felt smaller group sizes would have been preferable and most favoured smaller bedrooms. Fewer institutional staff management practices took place in the more domestic environments. Provision for outdoor play tended to be neglected. 相似文献
88.
C Matthews 《Journal of communication disorders》1991,24(1):21-39
A patient with chronic agrammatic Broca's aphasia presented with symptoms of deep dyslexia, in which it is presumed that phonologic processing of the written message is disrupted. Functional reorganization of the "nonlexical" or phonetic route of reading was undertaken according to principles of A. R. Luria, whereby the patient must learn consciously to control behaviors that had formerly been unconscious and automatic. This patient's responses in treatment made it clear that the phonetic route encompasses at least two dissociable functions, grapheme-phoneme conversion and sequential analysis. This is discussed in light of Luria's ideas regarding the functions of the precentral and postcentral regions of sensori-motor cortex. 相似文献
89.
T W Shields G A Higgins M J Matthews R J Keehn 《The Journal of thoracic and cardiovascular surgery》1982,84(4):481-488
In an attempt to define the role of initial surgical resection in patients with undifferentiated small cell carcinoma of the lung, we reviewed the experience of the Veterans Administration Surgical Oncology Group (VASOG). One hundred forty-eight patients with small cell carcinoma of the lung had undergone a potentially "curative" resection. This represented 4.7% of "curative" resections carried out in four major prospective adjuvant chemotherapy trials. In the early trials (101 patients), 16 patients (15.8%) died within the first 30 postoperative days. These patients have been excluded from the analysis of long-term survival, since in the more recent trials postoperative deaths were excluded prior to randomization. In the 132 patients remaining, the 5 year survival rate by the life-table method was 23.0%. The tumor of each was classified pathologically by the TNM system. Five-year survival rates for each category were as follows: T1 N0 M0 59.9%, T1 N1 M0 31.3%, T2 N0 M0 27.9%, T2 N1 M0 9.0%, and any T3 or N2 3.6%. The effect of postoperative adjuvant chemotherapy was evaluated in each of the trials. No beneficial effect of the adjuvant therapy was noted with a one or two course regimen of either nitrogen mustard or cyclophosphamide, but possible benefit, although not significant, was noted in a prolonged intermittent chemotherapy trial of cyclophosphamide either alone or alternating with methotrexate. In the most recent trial of prolonged intermittent courses of 1-(2-chlorethyl)-3-cyclohexyl-l-nitrosourea (CCNU) and hydroxyurea, a 5 year survival rate of 80.8% was noted in those receiving adjuvant chemotherapy as compared to a 38.1% in the control group. We conclude that resection is definitely indicated in patients with T1 N0 M0 lesions and probably indicated in those with T1 N1 M0 or T2 N0 M0 lesions. Primary surgical resection is contraindicated in patients with any other TNM category. 相似文献
90.
Results of treatment in 72 children with a relapse of acute lymphoblastic leukaemia were analysed. A second remission was induced in 57 children (79%). Remission rates were significantly higher in males, and in patients with white cell counts less than 30 X 10(9)/L. The median duration of the second remission was only four months, and the median duration of survival from the time of relapse was nine months. The median duration of survival from the time of diagnosis was 27 months. Among children who suffered a relapse was a small group who had prolonged survival and prolonged second remissions. It is uncertain whether some of these may have a chance of "cure". 相似文献