全文获取类型
收费全文 | 1745篇 |
免费 | 199篇 |
国内免费 | 26篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 42篇 |
妇产科学 | 102篇 |
基础医学 | 262篇 |
口腔科学 | 17篇 |
临床医学 | 151篇 |
内科学 | 387篇 |
皮肤病学 | 12篇 |
神经病学 | 127篇 |
特种医学 | 160篇 |
外科学 | 203篇 |
综合类 | 37篇 |
一般理论 | 1篇 |
预防医学 | 61篇 |
眼科学 | 28篇 |
药学 | 144篇 |
中国医学 | 14篇 |
肿瘤学 | 217篇 |
出版年
2023年 | 7篇 |
2022年 | 14篇 |
2021年 | 24篇 |
2020年 | 22篇 |
2019年 | 27篇 |
2018年 | 38篇 |
2017年 | 34篇 |
2016年 | 27篇 |
2015年 | 49篇 |
2014年 | 59篇 |
2013年 | 68篇 |
2012年 | 123篇 |
2011年 | 122篇 |
2010年 | 84篇 |
2009年 | 79篇 |
2008年 | 98篇 |
2007年 | 92篇 |
2006年 | 80篇 |
2005年 | 85篇 |
2004年 | 91篇 |
2003年 | 76篇 |
2002年 | 70篇 |
2001年 | 60篇 |
2000年 | 62篇 |
1999年 | 65篇 |
1998年 | 14篇 |
1997年 | 22篇 |
1996年 | 25篇 |
1995年 | 18篇 |
1994年 | 11篇 |
1993年 | 11篇 |
1992年 | 30篇 |
1991年 | 27篇 |
1990年 | 33篇 |
1989年 | 25篇 |
1988年 | 24篇 |
1987年 | 25篇 |
1986年 | 18篇 |
1985年 | 17篇 |
1984年 | 17篇 |
1983年 | 13篇 |
1982年 | 9篇 |
1981年 | 11篇 |
1980年 | 7篇 |
1979年 | 11篇 |
1978年 | 9篇 |
1977年 | 9篇 |
1976年 | 7篇 |
1972年 | 4篇 |
1971年 | 4篇 |
排序方式: 共有1970条查询结果,搜索用时 15 毫秒
11.
12.
海绵质骨螺旋钉拔出试验之生物力学分析 总被引:1,自引:1,他引:1
评估螺旋钉设计优劣的简便方法之一为拔出试验。虽然比较用之海绵质骨试件可取自相同部位,自同一方向植入螺旋钉,并具有相同基准。然而因各处海绵质骨骼结构不尽相同,至今尚未有人探讨如使用不同之海绵质骨结构,例如近似等向性之杆状结构,或是板与杆组合之有强列方向排列者,对于螺旋钉拔出之最大力量有多大影响?采用牛股骨远端部位及牛颈椎C2~C6作为不同结构特性之试体。并各由两相互垂直之方向旋入螺旋钉,来做拔出试验。最后并建立一三维有限元素模型,用以研究螺纹周围之变形模式及其预测拔出最大力量的准确性。模型分析中以应变能密度准则作为破坏之参考标准。 相似文献
13.
In neurodegenerative diseases, such as Alzheimer's disease or HIV encephalitis, neuronal DNA fragmentation has been observed at unexpected high frequencies, without definitive evidence for activation of an irreversible apoptotic pathway. The wobbler mouse is a suggested genetic model of neurodegenerative disease. The mutant mouse develops normally until the fourth week of age when atrophy and weakness of forelimb muscles become apparent. There is a slow progression of the disease and wobbler mice may survive for several months. Spinal cord examination reveals the presence of several motoneurons with perikaryal vacuolar degeneration. In this study, we observed, using terminal dUTP nick-end-labelling staining in mutant spinal cord sections, a massive although very transient DNA fragmentation in different cell types, including glial cells and motoneurons, before the apparition of any clinical symptoms. In older wobbler mice, this DNA fragmentation had completely disappeared and the majority of motoneurons survived. To our knowledge, this is the first example of a massive and transient DNA fragmentation in the central nervous system during the early course of a neurodegenerative disease. 相似文献
14.
Purpose To review the pathogenesis, clinical presentation, diagnostic assessment and treatment regimens of steroid-induced bone loss. Data sources An English-language literature search (MEDLINE 1966-1999) and bibliographic reviews of textbooks and review articles. Study selection Cross-sectional and prospective studies with BMD measurements or fracture rate. Results The greatest rate of bone loss occur during the first 6 to 12 months of steroid therapy, affecting trabecular more than cortical bone. High steroid dosage for a prolonged period, prevalent fracture, hypogonadism, older age, low calcium intake and family history of osteoporosis are risk factors for steroid-induced bone loss. Based on bone density results, patients with osteoporosis or osteopenia with a T-score below -1.5 should receive antiresorptive treatment during steroid therapy. Among the various antiresorptive agents, bisphosphonates have the strongest evidence of preventing steroid-induced bone loss. Conclusion The most important step in the management of steroid-induced osteoporosis is the proper assessment of the individual patient’s risk of bone loss, and the selection of appropriate anti-resorptive agent for each patient. 相似文献
15.
Chen Z Fisher R Li B Kamata T Kung H Lautenberger J Rhim J 《International journal of oncology》1997,10(6):1179-1184
We investigated the inhibitory effects of intrasplenic combination therapy with OK-432 and recombinant interleukin-2 (IL-2) on liver metastasis of colorectal carcinoma. Intrasplenic administration group significantly inhibited the development of liver metastasis compared with subcutaneous administration group (p<0.05). Combination therapy significantly inhibited the development of subclinical liver metastasis compared with that in the control group. Combination therapy decreased the percentage of cells expressing CD8a, which may be a part of effective factors of combination therapy, and improved overall survival rate. These findings suggested intrasplenic combination therapy with OK-432 and IL-2 might be effective in inhibiting liver metastasis of colorectal carcinoma. 相似文献
16.
OBJECTIVE: The present study sought to examine use prevalence and factors associated with use of analgesic and psychotropic medications in community-dwelling older people with chronic non-malignant pain. METHOD: The study group comprised 193 community-dwelling older people with daily chronic non-malignant pain who were selected from a random sample of 1,000 older people in Melbourne. RESULTS: The use prevalence for the study group was 63% for analgesics and 39% for psychotropic medications, which is higher than the general older population without chronic pain (p < 0.00001). More women with chronic pain used analgesics, while psycho-social factors such as problems with sleeping and living at home alone were found to be associated with an increased use of psychotropic medications. CONCLUSION: A high proportion of community-dwelling older people with chronic non-malignant pain use analgesic and psychotropic medications. IMPLICATIONS: These findings provide the basis for further investigation into the level and appropriateness of analgesic and psychotropic medication use by older people with chronic pain. 相似文献
17.
Quantitative ultrasound (QUS) is emerging as a simple, inexpensive and noninvasive method for assessing bone quality and
assessing fracture risk. We assessed the usefulness of a contact calcaneal ultrasonometer by studying normal premenopausal
women (group I, n= 53), normal postmenopausal women (group II, n= 198), and osteoporotic women without (group III, n= 141) and with vertebral fractures (group IV, n= 53). The osteoporotic subjects had a T-score of the spine or hip neck bone mineral density (BMD) <−2.5 based on the local Chinese peak young mean values. When compared
with postmenopausal controls, mean broadband ultrasound attenuation (BUA), speed of sound (SOS), and quantitative ultrasound
index (QUI) were 26%, 2.1% and 25% lower in women with vertebral fractures (p all <0.005). The correlation coefficients between QUS parameters and BMD of the spine and hip ranged between 0.4 and 0.5.
The ability of the QUS to discriminate between patients groups was determined based on the mean value of normal premenopausal
women in group I. The mean T-score for women with fractures was −2.87 ± 1.02 for BUA, −2.54 ± 0.79 for SOS, −3.17 ± 0.70 for QUI, −2.65 ± 0.86 for L2–4
BMD and −2.53 ± 0.66 for hip neck BMD. After adjustment for age and body mass index, the odds ratio of vertebral fracture
was 1.71 (95% CI 1.2–2.6) for each 1 SD reduction in BUA, 2.72 (1.3–5.3) for SOS, 2.58 (1.4–4.6) for QUI, 2.33 (1.6–3.3) for
L2–4 BMD, 2.09 (1.37–3.20) for femoral neck BMD and 1.88 (1.34–2.92) for total hip BMD. The association between the QUS parameters
and vertebral fracture risk persisted even adjustment for BMD. The area under the receiver operating characteristic curve
for BUA for vertebral fracture was 0.92, for SOS, QUI, L2–4 BMD and femoral neck BMD was 0.95, and for total hip was 0.91.
Received: 7 January 1999 / Accepted: 18 May 1999 相似文献
18.
Newton D Pearson J Xue Y Smith M Fogler W Mikulski S Alvord W Kung H Long D Rybak S 《International journal of oncology》1996,8(6):1095-1104
Onconase, a ribonuclease isolated from Rana pipiens oocytes and early embryos, is a member of the RNase A superfamily. Onconase has anti-neoplastic properties both in vitro and in vivo, and is undergoing clinical evaluation. In the present study, Onconase was combined with or conjugated to MRK16, an anti-P-glycoprotein (Pgp) monoclonal antibody. The interaction of these combinations with vincristine (VCR) against parental and multidrug resistant (MDR), Pgp expressing, human colon carcinoma cells caused increased VCR cytotoxicity in vitro and enhanced survival of athymic nude mice given transplants of drug resistant HT-29(mdr1) cells in vivo. The results suggest that combination treatment with Onconase and other agents that modulate the chemosensitivity of Pgp-expressing human tumor cells has the potential to overcome MDR. 相似文献
19.
254例肾细胞癌的诊治及预后 总被引:2,自引:1,他引:2
目的探讨肾癌的临床诊治方法及预后.方法对本院1993年1月~2001年12月收治的254例肾癌临床资料进行回顾性分析及随访.结果典型肾癌“三联征”的发生率为2.4%;肾癌偶发癌占45.7%.“肾外表现”主要有:贫血40.9%,消瘦14.6%,发热12.6%,高血压10.2%.病程<3个月占73.6%(187/254).辅助检查以B超、CT为主.治疗以肾癌根治术为主,占87.4%,术后结合干扰素治疗,效果确切.术后3年、5年生存率分别为78.7%、72.9%.预后多因素分析结果表明,肾癌的预后与肿瘤分期、直径大小和C-erbB2阳性与否相关.结论临床上无任何表现而体检偶发的肾癌日渐增多,典型的肾癌“三联征”已少见.综合分析患者的病史、体检,结合辅助检查,有助于肾癌的早期诊断,适当条件下的健康体检有积极意义.治疗仍以肾癌根治术为主,术后免疫治疗有积极的意义.肿瘤分期、直径大小和C-erbB2阳性与否对肾癌的预后有提示作用. 相似文献
20.