全文获取类型
收费全文 | 5124篇 |
免费 | 301篇 |
国内免费 | 50篇 |
专业分类
耳鼻咽喉 | 64篇 |
儿科学 | 91篇 |
妇产科学 | 67篇 |
基础医学 | 744篇 |
口腔科学 | 345篇 |
临床医学 | 433篇 |
内科学 | 1047篇 |
皮肤病学 | 113篇 |
神经病学 | 448篇 |
特种医学 | 175篇 |
外科学 | 604篇 |
综合类 | 34篇 |
一般理论 | 1篇 |
预防医学 | 561篇 |
眼科学 | 61篇 |
药学 | 465篇 |
中国医学 | 32篇 |
肿瘤学 | 190篇 |
出版年
2023年 | 50篇 |
2022年 | 124篇 |
2021年 | 165篇 |
2020年 | 126篇 |
2019年 | 131篇 |
2018年 | 181篇 |
2017年 | 139篇 |
2016年 | 144篇 |
2015年 | 167篇 |
2014年 | 232篇 |
2013年 | 297篇 |
2012年 | 424篇 |
2011年 | 440篇 |
2010年 | 210篇 |
2009年 | 225篇 |
2008年 | 333篇 |
2007年 | 322篇 |
2006年 | 280篇 |
2005年 | 217篇 |
2004年 | 159篇 |
2003年 | 159篇 |
2002年 | 151篇 |
2001年 | 116篇 |
2000年 | 103篇 |
1999年 | 85篇 |
1998年 | 40篇 |
1997年 | 38篇 |
1996年 | 26篇 |
1995年 | 28篇 |
1994年 | 33篇 |
1993年 | 23篇 |
1992年 | 30篇 |
1991年 | 22篇 |
1990年 | 22篇 |
1989年 | 20篇 |
1988年 | 12篇 |
1987年 | 22篇 |
1986年 | 19篇 |
1985年 | 12篇 |
1984年 | 10篇 |
1983年 | 7篇 |
1982年 | 11篇 |
1981年 | 13篇 |
1980年 | 7篇 |
1979年 | 10篇 |
1977年 | 9篇 |
1976年 | 8篇 |
1975年 | 9篇 |
1969年 | 20篇 |
1967年 | 8篇 |
排序方式: 共有5475条查询结果,搜索用时 15 毫秒
41.
Spatial learning and neurogenesis: Effects of cessation of wheel running and survival of novel neurons by engagement in cognitive tasks 下载免费PDF全文
Lívia Clemente Motta‐Teixeira Silvia Honda Takada Aline Vilar Machado‐Nils Maria Inês Nogueira Gilberto Fernando Xavier 《Hippocampus》2016,26(6):794-803
Physical exercise stimulates cell proliferation in the adult dentate gyrus and facilitates acquisition and/or retention of hippocampal‐dependent tasks. It is established that regular physical exercise improves cognitive performance. However, it is unclear for how long these benefits last after its interruption. Independent groups of rats received both free access to either unlocked (EXE Treatment) or locked (No‐EXE Treatment) running wheels for 7 days, and daily injections of bromodeoxyuridine (BrdU) in the last 3 days. After a time delay period of either 1, 3, or 6 weeks without training, the animals were tested in the Morris water maze (MWM) either in a working memory task dependent on hippocampal function (MWM‐HD) or in a visible platform searching task, independent on hippocampal function (MWM‐NH). Data confirmed that exposure of rats to 7 days of spontaneous wheel running increases cell proliferation and neurogenesis. In contrast, neurogenesis was not accompanied by significant improvements of performance in the working memory version of the MWM. Longer time delays between the end of exercise and the beginning of cognitive training in the MWM resulted in lower cell survival; that is, the number of novel surviving mature neurons was decreased when this delay was 6 weeks as compared with when it was 1 week. In addition, data showed that while exposure to the MWM‐HD working memory task substantially increased survival of novel neurons, exposure to the MWM‐NH task did not, thus indicating that survival of novel dentate gyrus neurons depends on the engagement of this brain region in performance of cognitive tasks. © 2015 Wiley Periodicals, Inc. 相似文献
42.
43.
44.
José Ananias Vasconcelos Neto Camila Teixeira Moreira Vasconcelos Sthela Maria Murad Regadas Leonardo Robson Pinheiro Sobreira Bezerra Kathiane Augusto Lustosa Sara Arcanjo Lino Karbage 《International urogynecology journal》2017,28(9):1415-1420
Introduction and hypothesis
The aim of this study was to evaluate the correlations between the POP-Q Bp point and the perineal body (Pb) and genital hiatus (Gh) measurements and constipation, anal incontinence, severity of symptoms and quality of life.Methods
The patients were distributed into two groups according to the posterior vaginal wall Bp point: one group with Bp ≤?1 (without posterior vaginal wall prolapse, control group) and the other group with Bp ≥0 (with posterior vaginal wall prolapse, case group). Demographic data, defecatory dysfunction and SF-36 scores were compared between the groups. Correlations between severity of posterior prolapse (Bp, Gh, Pb and Gh?+?Pb) and severity of bowel symptoms were also calculated.Results
A total of 613 women were evaluated, of whom 174 were included, 69 (39.7%) in the control group and 105 (60.3%) in the case group. The groups were similar in terms of anal incontinence, fecal urgency and/or constipation. There was no correlation between the severity of constipation and anal incontinence according to the Wexner score, and the severity of posterior vaginal wall prolapse measured in terms of point Bp. There were, however, statistically significant differences in Pb, Gh and Gh?+?Pb between the groups. The Pb and Gh?+?Pb measurements were positively correlated with symptoms of constipation, as well as with the scores of some SF-36 domains, but were not correlated with anal incontinence.Conclusions
These results suggest that the severity of posterior vaginal wall prolapse is not correlated with constipation or anal incontinence, but Pb and Gh?+?Pb measurements are correlated with constipation and SF-36 scores.45.
Jones C Teixeira PG Inaba K Keesara SR Rhee P Brown C Salim A Browder T Demetriades D 《The American surgeon》2008,74(10):935-938
CT Venography (CTV) performed at the time of CT pulmonary angiography (CTPA) images the central, pelvic, and extremity venous circulation with minimal additional time, radiation, and no added contrast. CTV has been added to CTPA routinely at our Level I trauma center since 2000, and we sought to determine if this addition had increased the diagnostic yield of CTPA in trauma patients. The attending radiologist's interpretation of all CTPA-CTV studies performed over a 5-year period ending in August 2006 were retrospectively reviewed. CTPAs and CTVs were categorized as "positive", "negative", or "indeterminate" for pulmonary embolus (PE) and deep venous thrombosis (DVT). During the study period, 3798 patients underwent both a CTPA and CTV; 309 (8%) of these were trauma patients. Forty-four (14%) had a PE diagnosed on CTPA. Seventeen (6%) had a DVT diagnosed on CTV. In eight (3%), the CTV added clinically relevant data, diagnosing a DVT in a patient without PE. As the consequences of a missed pelvic DVT are high and the added time burden, radiation, and contrast required for a CTV are low, further investigation into optimizing the sensitivity of CTV performed at the time of CTPA is warranted. 相似文献
46.
J. Malheiro L. Martins I. Fonseca A.M. Gomes L. Dias J. Dores R. Seca A. Henriques A. Cabrita M. Teixeira 《Transplantation proceedings》2009,41(3):909-418
Simultaneous pancreas-kidney transplantation (SPK) is the treatment of choice for selected diabetic patients with end-stage renal disease. Maintenance steroid therapy is associated with significant morbidity and mortality among SPK transplant recipients. Steroid withdrawal regimens are becoming more common, albeit with reservations regarding its safety and efficacy. We performed a retrospective review of 77 SPK transplant recipients from May 2000 to December 2007. The subjects received induction therapy with thymoglobulin followed by maintenance immunosuppression with tacrolimus and mycophenolate mofetil. A late steroid withdrawal protocol was adopted. The rates of acute rejection, graft and patient survival, and side effects were analyzed. One-year patient, kidney, and pancreas survivals were 93%, 91%, and 86%, respectively. Eleven patients experienced acute rejection. Mean follow-up time was 1155.5 ± 776.1 days. Prednisolone withdrawal was carried out between 6 and 12 months posttransplantation in 42 patients (77.8%) with at least 1 year follow-up; no case of acute rejection occurred. At present, 72 patients have a functioning kidney graft, and 65 patients also have a functioning pancreas graft. The mean serum creatinine is 1.12 ± 0.49 mg/dL and the mean HbA1c concentration is 4.5% ± 0.4%. The patients have a low prevalence of hypertension, hyperlipidemia, and obesity. Steroid withdrawal was successful and safe in the majority of in-study patients and safe without an increase of immune events. Our patient and graft outcomes are within other international SPK transplant units standards. 相似文献
47.
Flávia Aparecida de Oliveira Eliza Carla Barroso Duarte Cláudia Teixeira Taveira Aline Abreu Máximo Érica Carvalho de Aquino Rita de Cássia Alencar Eneida Franco Vencio 《Head and neck pathology》2009,3(4):271-275
Salivary gland tumors consist of a group of heterogeneous lesions with complex clinicopathological characteristics and distinct
biological behaviors. Worldwide series show a contrast in the relative incidence of salivary gland tumors, with some discrepancies
in clinicopathological data. The main aim of this study was to describe demographic characteristics of 599 cases in a population
from Central Brazil over a 10-year period and compare these with other epidemiological studies. Benign tumors represented
78.3% of the cases. Women were the most affected (61%) and the male:female ratio was 1:1.6. Parotid gland tumors were the
most frequent (68.5% of cases) and patient age ranged from 1 to 88 years-old (median of 45 years old). The most frequent tumors
were pleomorphic adenomas (68.4%) and benign tumors were significantly more frequent in the parotid (75.9%), while malignant
tumors were more frequent in the minor salivary glands (40%) (P < 0.05). In conclusion, women and the parotid gland were the most affected and pleomorphic adenoma was the most frequent
lesion, followed by adenoid cystic carcinoma and Warthin’s tumor. 相似文献
48.
Ana Flávia Marçal Pessoa PhD Juliana Costa Florim MSc Hosana Gomes Rodrigues PhD Vinicius Andrade‐Oliveira PhD Simone A. Teixeira PhD Kaio Fernando Vitzel PhD Rui Curi PhD Niels Olsen Saraiva Câmara PhD Marcelo N. Muscará PhD Marcelo Lazzaron Lamers PhD Marinilce Fagundes Santos PhD 《Wound repair and regeneration》2016,24(6):981-993
Oxidative stress aggravates several long‐term complications in diabetes mellitus. We evaluated the effectiveness of the oral administration of antioxidants (vitamins E and C, 40 and 100 mg/kg b.w., respectively) on skin wound healing acceleration in alloxan‐induced diabetic mice. Mice were wounded 30 days after the induction of diabetes. Antioxidants were effective in preventing oxidative stress, as assessed by TBARS. The enzymes catalase, glutathione reductase, glutathione peroxidase, and superoxide dismutase were increased in diabetics on the 3rd day post‐wounding; catalase and glutathione peroxidase remained still augmented in diabetics after 14th day postwounding, and the treatment with vitamins restored their activities to control. After 3 days, diabetic mice showed lower infiltration of inflammatory cells (including CD11b+ and Ly6G+ cells) and reduced levels of KC, TNF‐α, IL‐1β, and IL‐12 p40 when compared with control mice. The treatment restored cytokine levels. After 14 days, diabetic mice showed late wound closure, persistent inflammation and delayed reepithelialization, accompanied by an increase in MIG+/CD206? macrophages whereas CD206+/MIG? macrophages were decreased. Cytokines IL‐12p40, TNF‐α, IL‐1β, and KC were increased and normal levels were restored after treatment with antioxidants. These results suggest that oxidative stress plays a major role in diabetic wound healing impairment and the oral administration of antioxidants improves healing by modulating inflammation and the antioxidant system with no effect on glycemia. 相似文献
49.
Objective To investigate the clinical and pathological characteristics of pauci-immune crescent glomerulo~nephritis (PICGN) in Chinese patients. Methods During 13 years (1985-1998), 6400 patients underwent non-transplanting renal biopsy. Twenty-four patients were diagnosed as PICGN. All clinical and laboratory data of these patients were collected from the patients’ records and used for detailed analysis. The diagnosis is based on clinico-pathologic findings. Results Of the 24 patients, 16 were females and 8 were males, with median age of 33 years (ranged 10-76 years). Microscopic polyarteritis (MPA) (33.3%) and systemic vasculitis (8.3%) were the secondary diseases. The incidence of PICGN was 0.38% in renal biopsies and 22.9% in crescentic glomerulonephritis. Clinically, most patients (75.0%) showed rapidly progressive nephritis with enlarged kidneys. At onset, gross hematuria was noted in 58.3% of patients, hypertension in 45.8%, nephrotic syndrome in 41.7%, and oliguria in 25.0%. However, systemic symptoms were rare except for anemia. Pathologically, necrosis of glomerular capillaries (62.5%), infiltration of monocytes and neutrophil cells in glomeruli (66.7%), and vasculitis in the interstitium (53.3%) were observed. In addition, glomerulosclerosis was noted in 45.8%, severe tubular atrophy in 83.3% and interstitial fibrosis in 75.0%. Anti-neutrophil cytoplasmic antibodies (ANCAs) were positive in 52.2%. All patients except two received intensively immunosuppressive therapy. Sixteen patients were available for long-term follow up (median 29.8 months, range 8-92 months). Twelve of them had life-sustaining renal function, four had normal serum creatinine (<124?μmol/L) and only 4 patients were dialysis-dependent. Conclusion PICGN is not rare in China. Early diagnosis and administration of immunosuppressive therapy, particularly in patients with rapidly progressive glomerulonephritis (RPGN), are important for good prognosis. 相似文献
50.
Passos CP Santos PR Aguiar MC Cangussu MC Toralles MB da Silva MC Nascimento RJ Campos MI 《Special care in dentistry》2012,32(2):55-60
This study investigated the prevalence of dental caries and periodontal condition in a population with sickle cell disease (SCD), analyzing some associations with disease severity. The Decayed, Missing and Filled Teeth index (DMFT) and Community Periodontal Index (CPI) were recorded for 99 individuals with SCD and 91 matched controls. Socio-demographic status, oral health behaviors, and history of clinical severity of SCD were assessed. Statistical comparisons were performed between the group with SCD and the control group, as well as multivariate logistic regression analyses with DMFT index and CPI as the dependent variables. The mean number of decayed teeth was significantly higher in individuals with HbSS. Older age, female gender, and daily smoking were identified as risk factors for higher DMFT, while older age and absence of daily use of dental floss were risk factors for the development of periodontal disease. In conclusion, risk factors known to cause caries and periodontal disease had more influence on oral health than the direct impact of SCD. 相似文献