全文获取类型
收费全文 | 687篇 |
免费 | 44篇 |
国内免费 | 45篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 42篇 |
妇产科学 | 2篇 |
基础医学 | 71篇 |
口腔科学 | 13篇 |
临床医学 | 122篇 |
内科学 | 136篇 |
皮肤病学 | 9篇 |
神经病学 | 33篇 |
特种医学 | 131篇 |
外科学 | 58篇 |
综合类 | 16篇 |
预防医学 | 20篇 |
眼科学 | 7篇 |
药学 | 98篇 |
中国医学 | 1篇 |
肿瘤学 | 16篇 |
出版年
2019年 | 3篇 |
2018年 | 6篇 |
2016年 | 2篇 |
2015年 | 5篇 |
2014年 | 10篇 |
2013年 | 14篇 |
2012年 | 11篇 |
2011年 | 12篇 |
2010年 | 27篇 |
2009年 | 25篇 |
2008年 | 14篇 |
2007年 | 41篇 |
2006年 | 16篇 |
2005年 | 14篇 |
2004年 | 9篇 |
2003年 | 16篇 |
2002年 | 13篇 |
2001年 | 16篇 |
2000年 | 19篇 |
1999年 | 22篇 |
1998年 | 42篇 |
1997年 | 35篇 |
1996年 | 39篇 |
1995年 | 27篇 |
1994年 | 18篇 |
1993年 | 22篇 |
1992年 | 16篇 |
1991年 | 11篇 |
1990年 | 18篇 |
1989年 | 37篇 |
1988年 | 38篇 |
1987年 | 27篇 |
1986年 | 22篇 |
1985年 | 17篇 |
1984年 | 10篇 |
1983年 | 12篇 |
1982年 | 10篇 |
1981年 | 8篇 |
1980年 | 7篇 |
1979年 | 5篇 |
1978年 | 6篇 |
1977年 | 12篇 |
1976年 | 5篇 |
1975年 | 5篇 |
1973年 | 5篇 |
1972年 | 7篇 |
1971年 | 2篇 |
1968年 | 2篇 |
1967年 | 5篇 |
1966年 | 2篇 |
排序方式: 共有776条查询结果,搜索用时 15 毫秒
81.
Quality of life and Parkinson's disease 总被引:1,自引:0,他引:1
Koplas PA Gans HB Wisely MP Kuchibhatla M Cutson TM Gold DT Taylor CT Schenkman M 《The journals of gerontology. Series A, Biological sciences and medical sciences》1999,54(4):M197-M202
BACKGROUND: People with Parkinson's disease (PD) have a progressive loss of function eventually leading to severe disability. Although PD would be expected to have a profound impact on an individual's psychosocial health, there is relatively limited research on its psychosocial effect. The purposes of this study were (a) to examine the relationships between physical disability, depression, and control beliefs and quality of life in people with PD and (b) to characterize how these psychosocial variables differ by stage of disease. METHODS: Eighty-six individuals from five stages based on clinical disability, ages 51-87, were interviewed. Established instruments were used to measure physical disability, depression, and control beliefs. Quality of life (QOL) was rated on a 5-point Likert scale. RESULTS: A multivariable regression model including physical disability, stage of disease, depression, mastery, and health locus of control predicted QOL (R2 = 0.48), with mastery as the only significant predictor (p = .0001). There were significant differences by PD stage for all variables (p < .05). CONCLUSIONS: Mastery predicted quality of life in individuals with PD even when depression and physical disability were included in the model. Differences in psychosocial variables by stage of PD suggest that the psychosocial profile of PD patients may change as the disease progresses. 相似文献
82.
Using albumin and crystalloid as the only replacement fluids, the effect of partial plasma exchange on the removal and recovery of normal plasma constituents was studied. The results of 30 procedures on 10 individuals were evaluated. Four patterns of removal are described: reduction in the concentration of fibrinogen and C3 were greater than would be expected based upon the extent of the exchange, while IgG, IgM, cholesterol, alkaline phosphatase and SGPT were removed as expected. Reduction of serum glutamicoxalacetic transaminase (SGOT), lactate dehydrogenase (LDH), amylase, and creatine phosphokinase (CPK) averaged 17% less, and uric acid, calcium and K+ averaged 53% less than expected. Concentrations of HCO-3 and glucose did not change. The mean recovery for all constituents except fibrinogen, C3, cholesterol. IgG and IgM was near 100% at 48-72 hr postpheresis. The 72-hr recovery of fibrinogen and complement was 66% and 60%, respectively. Cholesterol recovery was also slow, requiring a minimum of 1 wk to reach prepheresis levels. Measured at a time when quantitative IgM levels were still reduced, alloantibody agglutinating activity (anti-A and anti-B) in a postpheresis sample exceeded prepheresis agglutinating activity. These data demonstrated that, depending upon quantity and frequency of pheresis, partial plasma exchange using albumin replacement may cause progressive marked reduction in concentrations of immunoglobulin, complement, fibrinogen, and cholesterol. Furthermore, newly synthesized antibody may have increased biologic activity. 相似文献
83.
Several observations noted by early investigators supported the supposition that in most cases, congenital glaucoma is determined by genetic factors. The genetic heterogeneity of PCG was confirmed by genetic linkage studies conducted in the 1990s when the authors determined that CYP1B1 is the congenital glaucoma gene at the GLC3A locus. The coding sequence of CYP1B1 has been subjected to extensive screening in familial and sporadic cases of glaucoma from numerous countries and from a large number of ethnic groups. These studies have provided evidence for extensive allelic heterogeneity at the GLC3A locus. This article also discusses the molecular evidence for reduced penetrance in congenital glaucoma and the phenotypic heterogeneity of CYP1B1 mutations, mouse models of CYP1B1, and the biochemistry of CYP1B1. 相似文献
84.
JB Epstein 《Oral diseases》1997,3(Z1):S124-S128
Kaposi's sarcoma (KS) is the most common neoplastic disease in patients with disease due to human immunodeficiency virus (HIV), and oral KS (OKS) is the commonest oral neoplasia. OKS has been managed by local excision, intralesional chemotherapy regional radiotherapy, and systemic chemotherapy. Comparison between studies is difficult as the severity of oral involvement is not well defined in most studies. This paper reviews the approach to the management of OKS and also presents a proposal for the clinical staging of OKS. Clinical staging of OKS will facilitate comparisons of outcomes of treatment of OKS and improve our understanding of the natural history of the neoplasia, which has varied presentation and rates of progression. 相似文献
85.
BC SHARMA RP SINGH YK CHAWLA KL NARASIMHAN KLN RAO SK MITRA JB DILAWARI 《Journal of gastroenterology and hepatology》1997,12(8):582-584
Shunt surgery is considered to be the treatment of choice in patients with non-cirrhotic portal hypertension. There is little data on the effect of side-to-side lieno-renal (SSLR) shunt on oesophageal variceal size, splenic size and splenic pulp pressure (SPP) in patients with non-cirrhotic portal hypertension. We evaluated pre- and postoperatively endoscopic grading of varices, splenic size and SPP for predicting shunt patency in 86 patients with non-cirrhotic portal hypertension: 56 with extrahepatic portal venous obstruction (EHPVO) and 30 with non-cirrhotic portal fibrosis (NCPF). The EHPVO patients with patent shunts (n= 47) showed significant reduction in SPP (pre-operative 43.56±7.9 vs postoperative 29.96±7.7 cm of saline), splenic size (6.5±2.8 vs 4.00±2.6 cm below costal margin) and varices grades (2.96±0.5 vs 0.92±0.8). Patients with blocked shunt (n= 9) did not show significant reduction in SPP and varices grades. However, there was reduction in spleen size (8.6±3.0 vs 6.3±4.3). In the NCPF group, 28 had patent shunts and showed significant reduction in SPP (46.3±13.5 vs 33.8±7.6 cm of saline), splenic size (9.1±3.3 vs 6.8±4.6 cm below costal margin) and varices grades (2.8±0.7 vs 1.05±0.96). As only two patients with NCPF had blocked shunts, no statistical comparison between patients with patent and patients with blocked shunts could be done. In conclusion, following SSLR, there is a significant reduction in SPP and varices grades in patients with patent shunts. Endoscopic grading of varices can be used to predict shunt patency. However, spleen size is not a good criteria for predicting shunt patency. 相似文献
86.
87.
MR Carvalho ; MA Krieger ; E Almeida ; W Oelemann ; MA Shikanai-Yassuda ; AW Ferreira ; JB Pereira ; A Saez-Alquezar ; PE Dorlhiac-Llacer ; DF Chamone ; et al. 《Transfusion》1993,33(10):830-834
Blood transfusion is one of the principal routes of transmission of Chagas' disease, a major endemic disease in Latin America. Methods for blood screening are not accurate and may yield false results that lead to high social and economic costs. This study compares two methods of diagnosing Chagas' disease (indirect immunofluorescence and hemagglutination) and several enzyme-linked immunosorbent assays (ELISAs) with regard to specificity and sensitivity, by using human sera with known serologic and parasitologic characteristics, as well as samples with discrepant results on conventional serologic tests. An ELISA using recombinant antigens showed no cross-reactivity with sera that were positive for other diseases. All evaluated ELISAs performed well, and their use may lead to a reduction of more than 50 percent in the number of discordant sera. Further improvements are needed in view of the complexity of the serologic diagnosis of Chagas' disease. 相似文献
88.
S Santos LJ Arauz J Baruque-Ramos I Lebrun SM Carneiro SA Barreto RP Schenkman 《Vaccine》2012,30(42):6064-6069
Serogroup B outer membrane vesicles (OMV) with iron regulated proteins (IRP) from Neisseria meningitidis constitute the antigen for the vaccine against the disease caused by this bacterium. Aiming to enhance final OMV concentration, seven batch experiments were carried out under four different conditions: (i) with original Catlin medium; (ii) with original Catlin medium and lactate and amino acids pulse at the 6th cultivation hour; (iii) with Catlin medium with double initial concentrations of lactate and amino acids and (iv) Catlin medium without glycerol and with double initial concentrations of lactate and amino acids. The cultivation experiments were carried out in a 7-L bioreactor under the following conditions: 36°C, 0.5atm, overlay air 1L/min, agitation: 250-850rpm, and O(2) control at 10%, 20h. After lactate and amino acids exhaustion, cell growth reached stationary phase and a significant release increase of OMV was observed. According to the Luedeking & Piret model, OMV liberation is non-growth associated. Glycerol was not consumed during cultivation. The maximum OMV concentration value attained was 162mg/L with correspondent productivity of 8.1mg/(Lh) employing Catlin medium with double initial concentrations of lactate and amino acids. The obtained OMV satisfied constitution and protein pattern criteria and were suitable for vaccine production. 相似文献
89.
Beta thalassemia in Melanesia: association with malaria and characterization of a common variant (IVS-1 nt 5 G----C) 总被引:3,自引:0,他引:3
Data on the distribution of beta thalassemia among over 6,000 Melanesians reveals a major difference in the carrier rates between populations in the malarious coastal regions of New Guinea and those living in the historically malaria-free Highlands. The island of Maewo in Vanuatu has a particularly high incidence of beta + thalassemia associated with a single restriction enzyme haplotype. Direct cloning into a plasmid vector and sequence analysis demonstrate that the mutation is a G to C transversion at position 5 of intron 1 of the beta- globin gene. Oligonucleotide probe surveys indicate that this variant accounted for all cases of beta thalassemia studied from Maewo. It is also common in coastal Papua New Guinea where haplotype and oligonucleotide probe data suggest that the molecular basis of beta thalassmia is more heterogeneous. 相似文献
90.
An association between clotting factor concentrates use and mortality in human immunodeficiency virus-infected hemophilic patients 总被引:1,自引:0,他引:1
Montoro JB; Oliveras J; Lorenzo JI; Tusell JM; Altisent C; Molina R; Ayestaran AI 《Blood》1995,86(6):2213-2219
There is much evidence that clotting factor concentrates (CFC), especially the so-called intermediate-purity preparations, exert an immunomodulating effect in vitro. The impact of this effect on the outcome of human immunodeficiency virus (HIV) infection in hemophiliacs is still controversial. In this retrospective cohort study, the effects of treatment with CFC on mortality and progression to acquired immunodeficiency syndrome (AIDS) were estimated while controlling for individual risk factors. Logistic regression and survival analysis, including the Cox proportional-hazards regression model, were performed with data from a 11-year follow-up of 225 hemophilic patients seropositive for HIV type 1 (HIV-1) of two hemophilia centers. Mortality and progression to AIDS rates were strongly associated with lower administration of CFC. After adjusting for age, a statistically significant and robust association was observed. The use of CFC was negatively associated with progression to AIDS (P = .0252) and mortality (P = .0033). The adjusted relative hazards of mortality and progression to AIDS rate between the most treated patients (> 700 IU/kg/yr) versus the least treated (< or = 700 IU/kg/yr) were 0.53 (confidence limits, 0.33 to 0.86) and 0.57 (0.39 to 0.84), respectively. Although the effects of other unmeasured risk factors cannot be excluded with certainty, these results suggest that there is a negative association between treatment with CFC and progression to AIDS and mortality. 相似文献