全文获取类型
收费全文 | 18357篇 |
免费 | 1132篇 |
国内免费 | 90篇 |
专业分类
耳鼻咽喉 | 319篇 |
儿科学 | 480篇 |
妇产科学 | 312篇 |
基础医学 | 2659篇 |
口腔科学 | 1567篇 |
临床医学 | 1360篇 |
内科学 | 3841篇 |
皮肤病学 | 452篇 |
神经病学 | 1241篇 |
特种医学 | 574篇 |
外科学 | 2124篇 |
综合类 | 95篇 |
一般理论 | 3篇 |
预防医学 | 2056篇 |
眼科学 | 253篇 |
药学 | 1292篇 |
1篇 | |
中国医学 | 189篇 |
肿瘤学 | 761篇 |
出版年
2023年 | 191篇 |
2022年 | 410篇 |
2021年 | 726篇 |
2020年 | 454篇 |
2019年 | 587篇 |
2018年 | 736篇 |
2017年 | 506篇 |
2016年 | 553篇 |
2015年 | 631篇 |
2014年 | 812篇 |
2013年 | 993篇 |
2012年 | 1403篇 |
2011年 | 1617篇 |
2010年 | 865篇 |
2009年 | 675篇 |
2008年 | 1068篇 |
2007年 | 1033篇 |
2006年 | 881篇 |
2005年 | 789篇 |
2004年 | 652篇 |
2003年 | 579篇 |
2002年 | 479篇 |
2001年 | 379篇 |
2000年 | 343篇 |
1999年 | 309篇 |
1998年 | 142篇 |
1997年 | 117篇 |
1996年 | 106篇 |
1995年 | 57篇 |
1994年 | 77篇 |
1993年 | 55篇 |
1992年 | 146篇 |
1991年 | 127篇 |
1990年 | 93篇 |
1989年 | 117篇 |
1988年 | 104篇 |
1987年 | 65篇 |
1986年 | 82篇 |
1985年 | 61篇 |
1984年 | 66篇 |
1983年 | 55篇 |
1982年 | 38篇 |
1981年 | 31篇 |
1980年 | 34篇 |
1979年 | 45篇 |
1978年 | 29篇 |
1977年 | 24篇 |
1976年 | 34篇 |
1971年 | 22篇 |
1969年 | 26篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.
Carmela Pestoni Porvén Vanessa Vieira dos Santos Jesus del Pozo Losada 《Journal of cosmetic and laser therapy》2017,19(8):465-468
Nodulocystic acne is prone to scarring and difficult to treat with treatments other than oral isotretinoin. The aim of this article is to discuss the role of a single session of a fractional carbon dioxide (CO2) laser combined with a topical treatment with a tretinoin and antibiotic gel for a month as a successful treatment to improve nodulocystic acne and chronic microcystic acne. Two cases were involved: the first with nodulocystic acne lesions that persisted after oral retinoids and the second with chronic microcystic acne resistant to topical treatments. After only one session of treatment with the CO2 laser and the topical treatment, a complete healing of the nodulocystic acne lesions was observed with minimal secondary effects. The microcystic acne showed great improvement. No other topical or oral treatment was needed. This treatment could be a safe and effective treatment for nodulocystic acne lesions and microcystic acne when other treatments fail. More studies should be performed to confirm our results. 相似文献
994.
Marcel Koenigkam‐Santos MD Puneet Sharma PhD Bobby Kalb MD John Carew PhD John N. Oshinski PhD Diego Martin MD PhD 《Journal of magnetic resonance imaging : JMRI》2009,29(6):1450-1456
Purpose
To quantitatively evaluate changes induced by the application of a femoral blood‐pressure cuff (BPC) on run‐off magnetic resonance angiography (MRA), which is a method generally previously proposed to reduce venous contamination in the leg.Materials and Methods
This study was Health Insurance Portability and Accountability Act (HIPAA)‐ and Institutional Review Board (IRB)‐compliant. We used time‐resolved gradient‐echo gadolinium (Gd)‐enhanced MRA to measure BPC effects on arterial, venous, and soft‐tissue enhancement. Seven healthy volunteers (six men) were studied with the BPC applied at the mid‐femoral level unilaterally using a 1.5T MR system after intravenous injection of Gd‐BOPTA. Different statistical tools were used such as the Wilcoxon signed rank test and a cubic smoothing spline fit.Results
We found that BPC application induces delayed venous filling (as previously described), but also induces significant decreases in arterial inflow, arterial enhancement, vascular‐soft tissue contrast, and delayed peak enhancement (which have not been previously measured).Conclusion
The potential benefits from using a BPC for run‐off MRA must be balanced against the potential pitfalls, elucidated by our findings. J. Magn. Reson. Imaging 2009;29:1450–1456. © 2009 Wiley‐Liss, Inc. 相似文献995.
OBJECTIVE: To assess the value of detecting IgA antibodies for the diagnosis of a recently acquired primary Toxoplasma infection. METHODS: IgA antibodies were screened in sera from 87 women with different serological profiles of Toxoplasma gondii IgM and IgG antibodies and Toxoplasma-specific IgG avidity. The IgM and IgG antibodies and the IgG avidity were measured with an automated Vitek Immuno Diagnostic Assay System (VIDAS). Anti-T.gondii IgA was measured with Platelia Toxo IgA TMB kits. RESULTS: All 12 sera obtained from women with clinical and/or serological evidence of a recently acquired Toxoplasma infection were positive for IgA. In 42 serum samples obtained more than 6 months after T. gondii infection from women with no clinical evidence of infection, but who had a positive IgM test and a high IgG avidity index, the IgA-enzyme linked immunosorbent assay (ELISA) test results were positive, negative, and doubtful in 16 (38.1%), 23 (54.8%), and 3 (7.1%) sera, respectively. In eight women, IgA was detected in sera collected more than 9 months after the onset of infection. The IgA test result was also positive in 11 of 12 sera (91.7%) obtained from women with no clinical evidence of toxoplasmosis, but who had a positive IgM test and a borderline IgG avidity index. The IgA-ELISA was negative in 21 sera obtained more than 2 years after the onset of T. gondii infection from women with no clinical evidence of toxoplasmosis, but who had a negative IgM test and a positive IgG test. CONCLUSION: These results show that IgA is not a dependable marker for a recently acquired primary Toxoplasma infection. 相似文献
996.
Pinho S Sarzedas S Pedroso S Santos A Rebordão M Avillez T Casal E Hermida M 《Clinical and experimental obstetrics & gynecology》2008,35(3):221-224
The term placenta accreta is used to describe any placental implantation in which there is abnormally firm adherence to the uterine wall. This condition complicates 1/2,500 deliveries and is rising in incidence. Abnormal placentation is associated with increased maternal morbidity and mortality from severe hemorrhage, uterine perforation, infection and loss of fertility. The reported experience of methotrexate treatment in the conservative management of placenta accreta is scant. Three cases of partial placenta increta managed with methotrexate are described. The patients were assessed with clinical surveillance, serum beta human chorionic gonadotrophin (beta-hCG) and imaging (ultrasonography and magnetic resonance in one case). In all cases conservative management with methotrexate resulted in undetectable serum beta-hCG, a decrease in the size of partial placenta retained, and undetectable vascularization. 相似文献
997.
Santos AO Ueda-Nakamura T Dias Filho BP Veiga Junior VF Pinto AC Nakamura CV 《Journal of ethnopharmacology》2008,120(2):204-208
Ethnopharmacological relevance
Copaiba oil has been used in folk medicine since the 19th century. The use of copaiba oils to treat leishmaniasis is cited in several ethnopharmacological studies. Nevertheless, the potential antileishmania of copaiba oils had not been studied.Aim of the study
Eight different kinds of Brazilian copaiba oils were screened for antileishmanial activity.Materials and methods
The antiproliferative effect of copaiba oil on promastigote and amastigote axenic were determined. To determine the survival index peritoneal macrophage were infected with promastigotes of Leishmania amazonensis and treated with copaiba oil. The cytotoxic effect of copaiba oil was assessed on macrophage strain J774G8 by assay of sulforhodamine B.Results
Copaiba oils showed variable levels of activity against promastigote forms with IC50 values in the range between 5 and 22 μg/mL. The most active oil was that from Copaifera reticulata (collected in Pará State, Brazil) with IC50 values of 5, 15, and 20 μg/mL for promastigote, axenic amastigote and intracellular amastigote forms, respectively. Amphotericin B showed IC50 of 0.058 and 0.231 μg/mL against promastigote and amastigote forms, respectively. Cytotoxicity assay showed that this copaiba oil obtained from Copaifera reticulata showed low cytotoxicity against J774G8 macrophages.Conclusion
Copaiba oils showed significant activity against the parasite Leishmania amazonensis. 相似文献998.
Frenna V Santos L Ohana E Bailey C Wattiez A 《Journal of minimally invasive gynecology》2007,14(2):169-171
STUDY OBJECTIVE: Ureteral endometriosis is rare, accounting for less than 0.3% of all endometriotic lesions. The aim of our study is to evaluate the prevalence of extrinsic ureteral endometriosis in women undergoing laparoscopic surgery for severe endometriosis and to suggest that laparoscopic ureterolysis represents a mandatory measure in all cases to avoid ureteral injury. METHODS: A retrospective analysis was performed of all cases of patients who underwent laparoscopic surgery for severe endometriosis at the departments of obstetrics and gynecology at CMCO-SIHCUS and Hautepierre Hospital, Strasbourg, from November 2004 through January 2006. MEASUREMENTS AND MAIN RESULTS: We recorded 54 patients with a mean age of 31 years and a mean body mass index of 21.9. Reported symptoms were dysmenorrhea (88%), severe dyspareunia (88%), severe pelvic pain (38.8%), and infertility (74%). Five women presented with dysuria, frequency, recurrent urinary tract infections, and pain in the renal angle, and 2 patients had hydronephrosis. We observed 3 patients (5.6%) with ureteral stenosis, 35 (64.8%) with adenomyotic tissue surrounding the ureter without stenosis, and 16 (29.6%) with adenomyotic tissue adjacent to the ureter. It was on the left side in 47.4% of cases, on the right side in 31.6% cases, and bilaterally in 21% of cases. In 9 patients, ureteral involvement was associated with bladder endometriosis (16.7%). In all patients, ureterolysis was performed. There was 1 case of ureteral injury during the procedure, 2 of transitory urinary retention, and 1 of uretero-vaginal fistula after surgery. During the first year of follow-up, the disease recurred in 4 patients, with no evidence of the disease in the urinary tract. CONCLUSION: Conservative laparoscopic surgery to relieve ureteral obstruction and remove pathologic tissue is the management of choice. Resection of part of the ureter should be performed only in exceptional cases. Ureterolysis should be performed in all patients before endometriotic nodule resection to recognize and prevent any ureteral damage. 相似文献
999.
Josivan G. Lima Lucia Helena C. Nobrega Natalia N. Lima Marcel C.F. dos Santos Maria de Fatima P. Baracho Francisco Bandeira Leonardo Capistrano Francisco Paulo Freire Neto Selma Maria B. Jeronimo 《Journal of clinical densitometry》2018,21(1):61-67
Berardinelli-Seip congenital lipodystrophy (BSCL) is a rare autosomal recessive syndrome characterized by a difficulty storing lipid in adipocytes, low body fat, hypoleptinemia, and hyperinsulinemia. We report here laboratory, bone mineral density (BMD), and bone mineral content findings of 21 patients (24.1?±?8.4?yr old, 14 females, 18 diabetics, 5.3% total body fat) with BSCL. The mean leptin was very low (0.91?±?0.42 ng/mL), and the mean values of the Z-scores for all studied sites were positive, except for the 33% radius (Z-score ?0.5?standard deviation [SD]). Twelve patients (57.1%) had a BMD Z-score higher than +2.5?SD in at least 1 site. There was no significant difference in the Z-scores between males and females. None of type 1 (AGPAT2) patients had Z-scores higher than +2.5?SD, and these patients had a smaller Z-score of BMD total body (0.26?SD vs 1.90?SD, p?=?0.022) and of bone mineral content (1.59?SD vs 3.3?SD, p?=?0.032) than type 2 (seipin) patients. Insulin, as well as HOMAIR (homeostasis model assessment), correlated positively with the BMD of all sites, except for the 33% radius. Z-Scores on this site (33% radius) were the smallest of all. More than half of our patients with BSCL have BMD Z-scores higher than +2.5?SD on at least 1 site, and this increase is more pronounced in the trabecular sites and in type 2 patients. 相似文献