全文获取类型
收费全文 | 5359篇 |
免费 | 352篇 |
国内免费 | 111篇 |
专业分类
耳鼻咽喉 | 101篇 |
儿科学 | 132篇 |
妇产科学 | 49篇 |
基础医学 | 767篇 |
口腔科学 | 116篇 |
临床医学 | 415篇 |
内科学 | 1075篇 |
皮肤病学 | 193篇 |
神经病学 | 349篇 |
特种医学 | 647篇 |
外科学 | 735篇 |
综合类 | 83篇 |
预防医学 | 227篇 |
眼科学 | 56篇 |
药学 | 488篇 |
中国医学 | 50篇 |
肿瘤学 | 339篇 |
出版年
2023年 | 33篇 |
2022年 | 88篇 |
2021年 | 144篇 |
2020年 | 76篇 |
2019年 | 91篇 |
2018年 | 153篇 |
2017年 | 95篇 |
2016年 | 168篇 |
2015年 | 193篇 |
2014年 | 303篇 |
2013年 | 296篇 |
2012年 | 376篇 |
2011年 | 370篇 |
2010年 | 216篇 |
2009年 | 229篇 |
2008年 | 250篇 |
2007年 | 271篇 |
2006年 | 259篇 |
2005年 | 272篇 |
2004年 | 208篇 |
2003年 | 180篇 |
2002年 | 179篇 |
2001年 | 109篇 |
2000年 | 86篇 |
1999年 | 101篇 |
1998年 | 76篇 |
1997年 | 83篇 |
1996年 | 93篇 |
1995年 | 78篇 |
1994年 | 48篇 |
1993年 | 59篇 |
1992年 | 48篇 |
1991年 | 55篇 |
1990年 | 46篇 |
1989年 | 69篇 |
1988年 | 64篇 |
1987年 | 51篇 |
1986年 | 42篇 |
1985年 | 36篇 |
1984年 | 25篇 |
1983年 | 21篇 |
1982年 | 26篇 |
1981年 | 21篇 |
1980年 | 22篇 |
1979年 | 25篇 |
1978年 | 10篇 |
1977年 | 22篇 |
1976年 | 16篇 |
1975年 | 14篇 |
1974年 | 8篇 |
排序方式: 共有5822条查询结果,搜索用时 0 毫秒
31.
32.
33.
Da-Eun Hyun Jwa-Bin Jeon Yeon-Sook Lee Yong-Nam Kim Minkyung Kim Seunghoon Ko Sang-Mo Koo Weon Ho Shin Chulhwan Park Dong-Won Lee Jong-Min Oh 《Materials》2022,15(12)
This work aims to fabricate a large-area ceramic substrate for the application of probe cards. Mullite (M) and cordierite (C), which both have a low thermal expansion coefficient, excellent resistance to thermal shock, and high durability, were selected as starting powders. The mullite–cordierite composites were produced through different composition ratios of starting powders (M:C = 100:0, M:C = 90:10, M:C = 70:30, M:C = 50:50, M:C = 30:70, and M:C = 0:100). The effects of composition ratio and sintering temperature on the density, porosity, thermal expansion coefficient, and flexural strength of the mullite–cordierite composite pellets were investigated. The results showed that the mullite–cordierite composite pellet containing 70 wt% mullite and 30 wt% cordierite sintered at 1350 °C performed exceptionally well. Based on these findings, a large-area mullite–cordierite composite substrate with a diameter of 320 mm for use in semiconductor probe cards was successfully fabricated. Additionally, the changes in sheet resistance and flexural strength were measured to determine the effect of the environmental tests on the large-area substrate such as damp heat and thermal shock. The results indicated that the mullite–cordierite composite substrate was extremely reliable and durable. 相似文献
34.
Intralymphatic histiocytosis (ILH) is a rare cutaneous condition with uncertain pathogenesis. It is characterized by dilated lymphatic vessels that contain histiocytes within their lumina. Although the etiology of ILH remains unknown, it has been associated with various inflammatory and neoplastic diseases, such as rheumatoid arthritis (RA), reaction to metal joint implants and Merkel cell carcinoma, breast cancer and colon cancer. An 83-year-old female presented with an erythematous patch on the left forearm that had appeared six months previous. She had suffered from osteoarthritis (OA) and the cutaneous lesion was located in the vicinity of the affected joint. Skin biopsy from the lesion showed dilated dermal vessels and some ectatic vessels that contained many mononuclear histiocytes. Based on the clinical and histopathological findings, we diagnosed her with ILH with OA. Two sessions of intralesional triamcinolone acetonide injection (5 mg/ml) were administered to treat the skin lesion, which gradually improved over a period of a few months. We here report a rare case of ILH associated with degenerative OA. 相似文献
35.
36.
Background/AimsWe investigated the effect of metabolic dysfunction-associated fatty liver disease (MAFLD) on future mortality and cardiovascular disease (CVD) using a prospective community-based cohort study.MethodsIndividuals from two community-based cohorts who were 40 to 70 years old were prospectively followed for 16 years. MAFLD was defined as a high fatty liver index (FLI ≥60) plus one of the following conditions overweight/obesity (body mass index ≥23 kg/m2), type 2 diabetes mellitus, or ≥2 metabolic risk abnormalities. Nonalcoholic fatty liver disease (NAFLD) was defined as FLI ≥60 without any secondary cause of hepatic steatosis.ResultsAmong 8,919 subjects (age 52.2±8.9 years, 47.7% of males), 1,509 (16.9%) had MAFLD. During the median follow-up of 15.7 years, MAFLD independently predicted overall mortality after adjustment for confounders (hazard ratio [HR], 1.33; 95% confidence interval [CI], 1.05 to 1.69) but NAFLD did not (HR, 1.20; 95% CI, 0.94 to 1.53). MAFLD also predicted CVD after adjustment for age, sex, and body mass index (HR, 1.35; 95% CI, 1.13 to 1.62), which lost its statistical significance by further adjustments. Stratified analysis indicated that metabolic dysfunction contributed to mortality (HR, 1.51; 95% CI, 1.21 to 1.89) and CVD (HR, 1.27; 95% CI, 1.02 to 1.59). Among metabolic dysfunctions used for defining MAFLD, type 2 diabetes mellitus in MAFLD increased the risk of both mortality (HR, 2.07; 95% CI, 1.52 to 2.81) and CVD (HR, 1.42; 95% CI, 1.09 to 1.85).ConclusionsMAFLD independently increased overall mortality. Heterogeneity in mortality and CVD risk of subjects with MAFLD may be determined by the accompanying metabolic dysfunctions. 相似文献
37.
Joo Young Na Ki Young Huh KyungSang Yu Joon Young Hyon Hye Cheong Koo Jong Ho Lee Ji Chang You JaeYong Chung 《CTS Clinical and Translational Science》2022,15(5):1123
For the long‐term efficacy of dry eye disease treatment, relieving underlying inflammation is necessary. Imatinib mesylate is a novel ophthalmic formulation of imatinib mesylate, which is expected to alleviate inflammation by inhibiting the discoidin domain receptor 1 activity. This study aims to evaluate the safety and pharmacokinetics of imatinib mesylate in healthy subjects. A randomized, double‐blind, placebo‐controlled study was conducted. In a single ascending dose, 16 subjects received a single eye drop of imatinib mesylate 0.1%, 0.3%, or matching placebo. In the multiple ascending dose (MAD), subjects received multiple eye drops of imatinib mesylate 0.1%, 0.3%, or matching placebo once daily for 7 days. Safety and tolerability were assessed by ophthalmic examination, including the visual analog scale (VAS) to monitor the burning sensation in the eyes. A total of four treatment‐emergent adverse events (TEAEs) occurred during the study. All TEAEs were mildly severe with no serious cases. VAS results in the 0.1% MAD group exhibited highest score of two points, whereas it was less than one point in others. Insignificant difference between the imatinib mesylate and placebo groups in the VAS results was seen. After a single dose administration of imatinib mesylate 0.1%, all plasma concentrations were below the lower limit of quantification. The peak plasma concentrations of imatinib were less than 0.54 µg/L in all groups. In conclusion, a single and multiple topical ophthalmic administration of imatinib mesylate was well‐tolerated in healthy subjects. Because there was minimal systemic exposure to imatinib, the adverse effect in the body seems to be insignificant. 相似文献
38.
Data collected among African‐American and Caucasian women and men in the southeastern USA indicate that participants' perceptions of nature, God's will and the human body influence reproductive health and decision‐making. Attitudes about the health care system, pharmaceutical companies and government programmes for fertility regulation reinforce these views and may negatively affect willingness to use contraceptive methods consistently and correctly. 相似文献
39.
The purpose was to retrospectively compare two-dimensional (2D) magnetic resonance cholangiography (MRC) including breath-hold
single-shot rapid acquisition with relaxation enhancement (RARE) and multislice half-Fourier RARE versus navigator-triggered
3D-RARE MRC in the evaluation of biliary malignancy. MRC findings were evaluated in 31 patients with malignant biliary obstruction,
including biliary malignancy, gallbladder carcinoma, and ampullary cancer. Two observers independently reviewed the images
to assess the overall image quality, artifacts, ductal conspicuity, extent of disease, diagnostic confidence of tumor extent,
and origin of tumor. The results were compared with surgical and histopathologic findings. Studies obtained with 3D-MRC were
of significantly higher technical quality than those obtained with 2D-MRC. However, the accuracy between two sequences for
classification of tumor showed no statistical significance. There was no significant difference between the Az values of 2D- and 3D-MRC for overall tumor extent in bilateral second order branch, intrapancreatic common bile duct (CBD)
involvement (Az = 0.889, 0.881 for 2D and Az = 0.903, 0.864 for 3D). Nor was there a significant difference between two sequences in the assessment of the origin of tumor.
Although 3D-MRC has superior image quality over 2D-MRC, 3D-MRC showed no statistically significant difference in accuracy
compared with 2D-MRC for evaluating the extent of disease in malignant biliary obstructions. 相似文献
40.
Bone marrow edema and associated pain in early stage osteonecrosis of the femoral head: prospective study with serial MR images 总被引:31,自引:0,他引:31
PURPOSE: To determine the accuracy of magnetic resonance (MR) cholangiography for demonstration of the biliary tract and detection of biliary complications in patients who have undergone orthotopic liver transplantation. MATERIALS AND METHODS: Breath-hold half-Fourier rapid acquisition with relaxation enhancement MR cholangiography was performed in 25 patients who had undergone orthotopic liver transplantation. MR cholangiograms were prospectively and independently interpreted by two radiologists for depiction of the biliary tract and ductal anastomosis and for complications (eg, biliary dilatation, stricture, stones). MR cholangiographic findings were correlated with findings from direct cholangiography (n = 24) and surgery (n = 1). RESULTS: MR cholangiography completely demonstrated first-order intrahepatic bile ducts in 23 (92%) patients, the donor extrahepatic bile duct in 25 (100%), the recipient extrahepatic bile duct in 17 of 18 (94%), and the anastomosis in 24 (96%). The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of MR cholangiography for detection of biliary dilatation and stricture were each 100%. Complete interobserver agreement occurred in the detection of biliary dilatation and stricture. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of MR cholangiography for detection of stones were 100% for one radiologist and 86%, 100%, 96%, 100%, and 95%, respectively, for the other. Both radiologists agreed on the diagnosis of bile duct stones in six of seven cases (kappa = 0.90). CONCLUSION: MR cholangiography enables accurate depiction of the biliary tract and detection of biliary complications in patients with an orthotopic liver transplant. 相似文献