全文获取类型
收费全文 | 2163篇 |
免费 | 135篇 |
国内免费 | 23篇 |
专业分类
耳鼻咽喉 | 16篇 |
儿科学 | 69篇 |
妇产科学 | 27篇 |
基础医学 | 241篇 |
口腔科学 | 246篇 |
临床医学 | 224篇 |
内科学 | 448篇 |
皮肤病学 | 25篇 |
神经病学 | 166篇 |
特种医学 | 198篇 |
外科学 | 224篇 |
综合类 | 28篇 |
预防医学 | 156篇 |
眼科学 | 11篇 |
药学 | 131篇 |
中国医学 | 11篇 |
肿瘤学 | 100篇 |
出版年
2023年 | 27篇 |
2022年 | 34篇 |
2021年 | 73篇 |
2020年 | 39篇 |
2019年 | 67篇 |
2018年 | 72篇 |
2017年 | 49篇 |
2016年 | 52篇 |
2015年 | 62篇 |
2014年 | 75篇 |
2013年 | 107篇 |
2012年 | 133篇 |
2011年 | 152篇 |
2010年 | 85篇 |
2009年 | 95篇 |
2008年 | 99篇 |
2007年 | 128篇 |
2006年 | 90篇 |
2005年 | 84篇 |
2004年 | 72篇 |
2003年 | 64篇 |
2002年 | 63篇 |
2001年 | 33篇 |
2000年 | 33篇 |
1999年 | 25篇 |
1998年 | 55篇 |
1997年 | 45篇 |
1996年 | 43篇 |
1995年 | 40篇 |
1994年 | 26篇 |
1993年 | 27篇 |
1992年 | 14篇 |
1991年 | 9篇 |
1990年 | 13篇 |
1989年 | 30篇 |
1988年 | 27篇 |
1987年 | 22篇 |
1986年 | 13篇 |
1985年 | 18篇 |
1984年 | 13篇 |
1983年 | 11篇 |
1982年 | 20篇 |
1981年 | 13篇 |
1980年 | 17篇 |
1978年 | 9篇 |
1977年 | 12篇 |
1976年 | 7篇 |
1968年 | 3篇 |
1967年 | 3篇 |
1966年 | 4篇 |
排序方式: 共有2321条查询结果,搜索用时 265 毫秒
31.
OBJECTIVE: To perform a retrospective analysis of patients with nasopalatine duct cysts (NPDC) in Brazil and compare with previous analyses. MATERIALS AND METHODS: The files of the Laboratory of Oral Pathology (Minas Gerais Federal University) from 1966 to 1997 were reviewed. Demographic, clinical and histologic data of patients with nasopalatine duct cysts were collected. RESULTS: The mean age of patients with nasopalatine duct cysts at the time of diagnosis was 37.4 years and with a predilection for males. The majority of cases were asymptomatic. Histologically, non-keratinized stratified squamous epithelium alone or in combination with other epithelia was observed in 93% of the cases. Recurrence was not recorded. CONCLUSION: The demographic, histopathological, radiographic, and clinical data of the NPDC in our series are similar to previous studies in other populations. 相似文献
32.
33.
Congenital pulmonary atresia with ventricular septal defect: angiographic and surgical correlates 总被引:1,自引:0,他引:1
Of 181 patients with severe congenital pulmonary atresia and ventricular septal defect or "type IV truncus" (an obsolete term), all but 11% had true central pulmonary arteries. These arteries were demonstrable by large serial biplane angiograms using multiple selective injections into collateral vessels, frequent photographic subtraction, and occasional pulmonary vein-wedge angiograms. These techniques are extremely important for accurate diagnosis and in planning corrective or palliative surgery, which was done in 77% of patients with pulmonary arteries. 相似文献
34.
Fujimoto Y Aguiar PH Freitas AB de Andrade AF Marino Júnior R 《Neurologia medico-chirurgica》2000,40(10):508-510
A 44-year-old female presented with Duret hemorrhage due to transtentorial herniation by extradural hematoma as a complication after craniotomy for treatment of spontaneous middle cranial fossa cerebrospinal fluid leakage through the oval window. Brain computed tomography revealed linear hemorrhage in the midbrain and the rostral pons. She awoke after 2 weeks in a coma, despite showing ocular bobbing and bilateral intranuclear ophthalmoplegia. She was discharged from the hospital with minimal neurological defects. Duret hemorrhage is usually fatal, but this case shows that early surgical decompression is the most important factor to avoid the worst sequelae. 相似文献
35.
36.
JC VANCE DC CHANT DI TUDEHOPE PH GRAY AJ HAYES 《Journal of paediatrics and child health》1997,33(6):504-508
Objectives: To describe the physical growth patterns of infants born to narcotic dependent mothers (INDM) over a 12 months period and, if possible, to relate the growth to drug taking patterns during pregnancy.
Methodology: The growth of a cohort of 43 INDM was measured during the first 12 months of life. Weight and length measurements were compared with percentile charts and converted to Z scores. Questionnaire data about drug taking practices, demographic variables and the neonatal period (including withdrawal scores) were obtained.
Results: Twenty-four (55.8%) of INDM had evidence of neonatal drug withdrawal requiring treatment with phenobarbitone. At birth, Z scores for weight and length indicated relative intrauterine growth retardation. By 12 months, there had been some catch up growth, but Z scores for weight and length were still below zero. Persistent weight retardation at 12 months was correlated with methadone dosage during pregnancy, but not the need for phenobarbitone therapy.
Conclusions: The growth patterns of INDM in the first 12 months of life indicated that at birth there was evidence of intrauterine growth retardation, but by 12 months the growth was little different from the rest of the community. There appears to be some influence of narcotic agents taken while pregnant on subsequent growth of INDM. 相似文献
Methodology: The growth of a cohort of 43 INDM was measured during the first 12 months of life. Weight and length measurements were compared with percentile charts and converted to Z scores. Questionnaire data about drug taking practices, demographic variables and the neonatal period (including withdrawal scores) were obtained.
Results: Twenty-four (55.8%) of INDM had evidence of neonatal drug withdrawal requiring treatment with phenobarbitone. At birth, Z scores for weight and length indicated relative intrauterine growth retardation. By 12 months, there had been some catch up growth, but Z scores for weight and length were still below zero. Persistent weight retardation at 12 months was correlated with methadone dosage during pregnancy, but not the need for phenobarbitone therapy.
Conclusions: The growth patterns of INDM in the first 12 months of life indicated that at birth there was evidence of intrauterine growth retardation, but by 12 months the growth was little different from the rest of the community. There appears to be some influence of narcotic agents taken while pregnant on subsequent growth of INDM. 相似文献
37.
JJ Rangasami DC Greenwood B McSporran PJ Smail CC Patterson NR Waugh 《Archives of disease in childhood》1997,77(3):210-213
OBJECTIVES: To calculate the incidence of type 1 diabetes in Scottish children aged less than 15 years between 1984 and 1993; to examine changes in incidence; and to calculate the prevalence of diabetes at the end of this period. DESIGN: Three data sources were used to construct the Scottish Study Group for the Care of Young Diabetics register: active reporting of all new cases; reports from the Scottish Morbidity Register 1; and local registers. SUBJECTS: All children resident in Scotland diagnosed with primary insulin dependent diabetes mellitus when less than 15 years of age between 1984 and 1993. MAIN OUTCOME MEASURES: Annual incidence and prevalence rate for Scotland; time trend in incidence over the 10 years; differences in incidence between the three different age groups; and completeness of the register. RESULTS: The average annual incidence for Scotland was 23.9/100,000 children. The prevalence rate was 1.5/1000 in 1993. A total of 2326 cases was identified from the three sources. Capture-recapture analysis suggests a case ascertainment of 98.6%. The annual incidence rates increased at a rate of 2% each year (rate ratio = 1.02, 95% confidence interval (CI) 1.01 to 1.03). The incidence was higher in boys than girls (rate ratio = 1.08, 95% CI 1.00 to 1.18), and the incidence rates increased with age: 15.3/100,000/year for age 0-4 years, 24.4/ 100,000/year for age 5-9 years, and 31.9/ 100,000/year for age 10-14 years. CONCLUSIONS: The incidence of type 1 diabetes in Scotland is increasing and the prevalence is relatively high. These findings have important implications for health service resource allocation. The Scottish Study Group for the Care of Young Diabetics' register provides a base for monitoring and research. 相似文献
38.
CONTEXT: Generalized anxiety disorder (GAD) is a chronic disorder that is associated with debilitating psychic and somatic symptoms. Venlafaxine extended-release (XR) capsules have been shown to be effective in short-term treatment of patients with GAD without major depressive disorder (MDD), but long-term data are needed to establish whether this agent confers persistent benefits. OBJECTIVE: To compare the 6-month efficacy and safety of a flexible dosage of venlafaxine XR in outpatients with GAD without associated MDD. DESIGN: Six-month, randomized, double-blind, placebo-controlled, parallel-group trial conducted May 1996 to October 1997. SETTING: Fourteen outpatient clinics and private psychiatric practices in the United States. PARTICIPANTS: A total of 251 outpatients aged 18 years or older who met Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria for GAD, had sufficient symptoms to require treatment, and did not have coexisting MDD. INTERVENTIONS: Participants were randomly assigned to receive either placebo (n=127) or venlafaxine XR (75, 150, or 225 mg/d, as required to control symptoms; n=124) for 28 weeks. MAIN OUTCOME MEASURES: Changes from baseline in the Hamilton Rating Scale for Anxiety (HAM-A) total score, the HAM-A psychic anxiety factor score, and the Clinical Global Impressions (CGI) scale Severity of Illness and Global Improvement scores, compared by intervention group. RESULTS: During weeks 6 through 28, response rates in the venlafaxine XR group were 69% or higher compared with rates of 42% to 46% in the placebo group (P<.001). By an evaluable-patient analysis, venlafaxine XR compared with placebo significantly improved anxiety scores from week 1 or 2 through week 28 on all primary efficacy measures, including the HAM-A total (P<.001), the HAM-A psychic anxiety factor (P<.001), and the CGI scale scores (P<.001). Adjusted mean changes from baseline to week 28 using last-observation-carried-forward methods were for HAM-A, venlafaxine XR -13.4, placebo -8.7 (P<.001); for HAM-A psychic anxiety score, venlafaxine XR -7.4, placebo -4.2 (P<.001); and for CGI-Improvement, venlafaxine XR 2.2, placebo 3.0 (P<.001). The most common treatment-emergent adverse event was nausea, followed by somnolence and dry mouth. CONCLUSIONS: This study is the first placebo-controlled demonstration of the long-term efficacy of any drug class in treating outpatients with DSM-IV-diagnosed GAD. Venlafaxine XR is an effective, rapidly acting, safe, once-daily agent for both the short- and long-term treatment of anxiety and may provide an important alternative to currently available anxiolytics. JAMA. 2000. 相似文献
39.
Cinthia Castro do Nascimento Odair Aguiar Junior Vania D’Almeida 《International journal of clinical and experimental pathology》2014,7(6):3488-3497
Mucopolysaccharidosis (MPS) I is a lysosomal storage disorder (LSD) that is characterised by alpha-L-iduronidase (Idua) deficiency and continuous deposition of glycosaminoglycans (GAGs), which consequently interferes with cell signalling mechanisms and results in multisystemic and progressive symptoms. The animal model of MPS I (Idua-/-) has been widely studied to elucidate the consequences and progression of the disorder; however, studies specifically assessing the male reproductive tract are lacking. The aim of this study was to evaluate some of the reproductive characteristics of male MPS I mice in two phases of life. Reproductive organ biometry, sperm counts, sperm morphological evaluation, plasma testosterone measurements and histopathological, histomorphometrical and immunohistochemical analysis were performed in 3- and 6-month-old C57BL/6 Idua+/+ and Idua-/- mice. Seminal vesicle weights were decreased in both the 3- and 6-month-old Idua-/- mice. Decrease in sperm counts and the majority of the histopathological signs were observed in the 6-month-old Idua-/- mice. No differences were detected in the sperm morphological analysis. Immunohistochemistry revealed that seminiferous tubules from 3-month-old Idua-/- mice were more intensely stained with anti-caspase-3 than 3-month-old Idua+/+ mice, but no difference was found at 6 months. These results suggest that MPS I interferes with male reproductive parameters both in 3 and 6-month-old animals and histopathological signs are more pronounced in 6-month-old mice, indicating that the effects of the disorder may intensify with the disease progression. 相似文献
40.
Isabel Cristina Celerino de Moraes Porto Flávio Henrique Baggio de Aguiar William Cunha Brandt Priscila Christiane Susy Liporoni 《Journal of dentistry》2013,41(8):732-739
ObjectivesThis study measured the degree of conversion (DC), sorption, solubility and microhardness of methacrylate (Filtek Z250 and Filtek Z350XT) and silorane-based composites (Filtek P90).MethodsDC was measured using near infrared spectroscopy immediately and 24 h after the photoactivation. Sorption and solubility measurements were performed after 24 h, 4 weeks and 12 weeks of storage in water. Knoop microhardness was measured after 24 h and after thermal cycling. The data were statistically analyzed using ANOVA followed by Tukey's, Tamhane or paired t-tests (α = 0.05).ResultsThe DC for P90 (37.22 ± 1.46) was significantly lower than the Z250 (71.44 ± 1.66) and Z350 (71.76 ± 2.84). Water sorption was highest in the Z250 and lowest in the P90. All the tested composites exhibited similar values after 24 h of immersion, and no significant differences were observed. No significant differences were observed between the solubilities of the P90 composite (12 weeks) and the Z250 or Z350 composites (4 weeks). KHN values were less elevated for the P90 composite and similar for the Z250 and Z350 composites. An effect of thermal cycling on KHN values was observed for all the composites (p < 0.001).ConclusionsSilorane produced the lowest DC and KHN values and exhibited lower water sorption and solubility compared to methacrylate-based composites. These differences suggest that silorane composites exhibit better hydrolytic stability after 3 months of water immersion compared to conventional methacrylate-based composites.Clinical significanceSilorane had higher hydrolytic stability after 3 months of water immersion than the methacrylate-based resins, despite the lower values of DC and KHN recorded. 相似文献