全文获取类型
收费全文 | 7942篇 |
免费 | 1380篇 |
国内免费 | 420篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 53篇 |
妇产科学 | 175篇 |
基础医学 | 618篇 |
口腔科学 | 237篇 |
临床医学 | 815篇 |
内科学 | 1041篇 |
皮肤病学 | 22篇 |
神经病学 | 93篇 |
特种医学 | 262篇 |
外科学 | 2768篇 |
综合类 | 1327篇 |
预防医学 | 544篇 |
眼科学 | 3篇 |
药学 | 894篇 |
4篇 | |
中国医学 | 768篇 |
肿瘤学 | 109篇 |
出版年
2024年 | 31篇 |
2023年 | 269篇 |
2022年 | 437篇 |
2021年 | 498篇 |
2020年 | 494篇 |
2019年 | 417篇 |
2018年 | 292篇 |
2017年 | 278篇 |
2016年 | 282篇 |
2015年 | 258篇 |
2014年 | 560篇 |
2013年 | 730篇 |
2012年 | 440篇 |
2011年 | 508篇 |
2010年 | 418篇 |
2009年 | 388篇 |
2008年 | 424篇 |
2007年 | 396篇 |
2006年 | 376篇 |
2005年 | 328篇 |
2004年 | 320篇 |
2003年 | 272篇 |
2002年 | 232篇 |
2001年 | 256篇 |
2000年 | 158篇 |
1999年 | 140篇 |
1998年 | 98篇 |
1997年 | 90篇 |
1996年 | 57篇 |
1995年 | 45篇 |
1994年 | 39篇 |
1993年 | 29篇 |
1992年 | 33篇 |
1991年 | 18篇 |
1990年 | 12篇 |
1989年 | 13篇 |
1988年 | 14篇 |
1987年 | 12篇 |
1986年 | 11篇 |
1985年 | 10篇 |
1984年 | 9篇 |
1983年 | 6篇 |
1982年 | 7篇 |
1981年 | 6篇 |
1980年 | 6篇 |
1979年 | 6篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1976年 | 5篇 |
1975年 | 3篇 |
排序方式: 共有9742条查询结果,搜索用时 15 毫秒
1.
Defining con-founders that affect the reliability of diagnostic tests for coronavirus disease 2019 is vital to breaking the chain of infection. The elderly population is a higher risk group for the emerging virus. However, gender seems to exert a critical role in modifying the infection risk among women owing to hormonal changes. The menopause transition is an exceptional period for older women where the protective and immunomodulatory effects of the estrogen hormone are lost. Accordingly, attention should be given to postmenopausal women since they will have an increased risk compared to their pre-menopausal peers. 相似文献
2.
骨质疏松症是常见的骨骼疾病,绝经后女性为骨质疏松症的高危人群。骨折风险评价工具(fracture risk assessment tool,FRAX?)是一款研究、应用广泛的骨折风险评估工具。近年来研究表明,虽然FRAX?尚不完美,但对女性人群的骨折具有合理的预测能力,结合其他骨折危险因素对该工具进行调整、改进的研究也多见报道。设立符合本国国情的FRAX?阈值有助于医生更好地使用该工具和进行临床决策。美国设立了固定的FRAX?阈值,英国则是按年龄分层的阈值。国内对FRAX?的研究尚处于初级阶段,暂无特异的干预阈值,这在一定程度上阻碍了该工具在我国的推广使用。笔者回顾了国内外FRAX?对女性骨质疏松性骨折的预测能力、骨量异常的诊断能力、在合并其他疾病的女性人群中的应用和干预阈值的研究等最新成果,为临床医生了解FRAX?的研究进展、探索针对我国人群干预阈值奠定基础。 相似文献
3.
I. R. Reid 《Journal of internal medicine》2015,277(6):690-706
There is an increasing number of effective therapies for fracture prevention in adults at risk of osteoporosis. However, shortcomings in the evidence underpinning our management of osteoporosis still exist. Evidence of antifracture efficacy in the groups of patients who most commonly use calcium and vitamin D supplements is lacking, the safety of calcium supplements is in doubt, and the safety and efficacy of high doses of vitamin D give cause for concern. Alendronate, risedronate, zoledronate and denosumab have been shown to prevent spine, nonspine and hip fractures; in addition, teriparatide and strontium ranelate prevent both spine and nonspine fractures, and raloxifene and ibandronate prevent spine fractures. However, most trials provide little information regarding long‐term efficacy or safety. A particular concern at present is the possibility that oral bisphosphonates might cause atypical femoral fractures. Observational data suggest that the incidence of this type of fracture increases steeply with duration of bisphosphonate use, resulting in concern that the benefit–risk balance may become negative in the long term, particularly in patients in whom the osteoporotic fracture risk is not high. Therefore, reappraisal of ongoing use of bisphosphonates after about 5 years is endorsed by expert consensus, and ‘drug holidays’ should be considered at this time. Further studies are needed to guide clinical practice in this area. 相似文献
4.
2型糖尿病及骨质疏松已成为我国最主要的慢性代谢性疾病。2型糖尿病常伴有血脂紊乱,常表现为低密度脂蛋白升高,而越来越多的研究表明血脂通过不同的方式影响骨代谢,其机制可能是通过抑制骨髓间充质干细胞成骨分化,通过RANK/RNAKL/OPG信号通路及炎症反应调节破骨细胞等方式调节骨代谢。 相似文献
5.
6.
目的 :研究老年人不同疾病时骨密度 (BMD)的分布情况。方法 :用DXADAS 6 0 0EX型骨密度仪对183例老年患者进行左侧远程桡骨加尺骨BMD检测。结果 :内分泌疾病组、消化道疾病组和其它疾病组的患病率分别为 72 7% ,2 0 6 %和 31 4 %。T值比较 :三组差异明显 (P <0 0 0 1)。累积骨丢失率 (ABLR)比较 :前一组明显高于后两组病人 (P <0 0 1)。BMD比较中 ,内分泌和其它疾病组明显低于消化道疾病组 (P <0 0 0 1)。相关分析显示 ,内分泌和消化道疾病组的年龄变化与BMD呈正相关 (r =0 5 19P <0 0 0 1和r =0 5 89P <0 0 0 1) ,内分泌疾病组和其它疾病组的体重变化与BMD呈正相关 (r=0 918P <0 0 0 1和r =0 338P <0 0 0 1)。结论 :老年人骨质疏松 (OP)患病率以内分泌疾病组最高 ,消化道疾病组较低 ;随年龄和体重增加 ,BMD降低加重。 相似文献
7.
E. I. Barengolts M. Berman S. C. Kukreja T. Kouznetsova C. Lin E. V. Chomka 《Calcified tissue international》1998,62(3):209-213
Estrogen deficiency is a risk factor for osteoporosis and coronary artery disease. Osteoporosis can be evaluated by measuring
bone mineral density (BMD). Coronary atherosclerotic burden can be evaluated by measuring coronary calcium using electron
beam computed tomography (EBT) of the heart. We compared coronary calcium scores in 45 asymptomatic postmenopausal women with
normal and low BMD. BMD of the lumbar spine and proximal femur was measured by dual X-ray absorptiometry (DXA), and coronary
calcium was measured quantitatively by EBT. Women were divided into control, osteopenia, and osteoporosis groups based on
the T score of the lumbar spine. Women were similar in age, years since menopause, height, weight, and body mass index (BMI).
BMD ± SD (g/cm2) of L1–L4 was 0.96 ± 0.11, 0.83 ± 0.03, and 0.73 ± 0.05, in control, osteopenia, and osteoporosis group, respectively. The
total coronary calcium score ± SD (relative units) was 41.9 ± 83.1, 115.1 ± 181.9, and 221.7 ± 355.4 for control, osteopenia,
and osteoporosis group, respectively; the score was significantly higher in the osteoporosis than in the control group. This
study provides initial data suggesting that women with osteoporosis may have a higher risk of developing coronary atherosclerosis. 相似文献
8.
妇科恶性肿瘤术后骨质疏松症的防治 总被引:1,自引:0,他引:1
为探讨妇科恶性肿瘤术后骨质疏松症的预防措施,采用补充紫竹爱维和乐力胶囊来预防骨质疏松的发生,分别与未服药的妇科恶性肿瘤及良性肿瘤术后作对照,并对其对骨代谢指标血清骨性碱性磷酸酶(BALP)及血清抗酒石酸酸性磷酸酶(TRAP)的影响进行了临床观察.结果发现恶性肿瘤术后较良性肿瘤术后患者的BALP降低,TRAP增高,服用紫竹爱维与乐力胶囊的患者TRAP均低于未服药的恶性肿瘤术后患者,P<0.05,均有显著性差异.表明妇科恶性肿瘤术后患者较良性肿瘤更易患骨质疏松症,服用紫竹爱维与乐力胶囊均能有效防治骨质疏松症,前者效果更佳,但应掌握性激素补充治疗(HRT)的应用指征. 相似文献
9.
10.
ALBERTO Q FARIAS LUCIANA L GONÇALVES EDUARDO LR CANÇADO ANTONIO C SEGURO SILVIA B CAMPOS CLARICE P ABRANTES-LEMOS FLAIR J CARRILHO 《Journal of gastroenterology and hepatology》2006,20(1):147-152
Background and Aims: Primary biliary cirrhosis (PBC) might be complicated by osteoporosis, whose etiology remains unknown but seems to be multifactorial. Prevalence rates of 30% to 60% for distal renal tubular acidosis (DRTA) have been reported in PBC patients, generally as incomplete DRTA. Although it is undisputed that a reduced bone mineral density (BMD) is the expected outcome among patients who have been suffering from longstanding chronic metabolic acidosis, it is unclear if incomplete DRTA is also associated with metabolic bone disease in PBC patients. The present study was undertaken to compare the BMD of PBC patients with and without DRTA.
Methods: The BMD of 23 PBC patients (11 with DRTA and 12 without), all with normal clearance of creatinine, was assessed by dual energy radiograph absorptiometry. The diagnosis of DRTA was made if the urine pH was above 5.4 in all samples after the oral acid overload, showing tubular inability to acidify urine in the presence of test-induced systemic metabolic acidosis.
Results: Densitometric signs of osteoporosis were found in 82% of DRTA cases and in 83% of patients without DRTA (difference not significant). There were no significant differences in BMD measurement, T and Z scores of patients with and without DRTA.
Conclusions: The present study could not support a correlation between the presence of DRTA and the bone loss observed in PBC patients. 相似文献
Methods: The BMD of 23 PBC patients (11 with DRTA and 12 without), all with normal clearance of creatinine, was assessed by dual energy radiograph absorptiometry. The diagnosis of DRTA was made if the urine pH was above 5.4 in all samples after the oral acid overload, showing tubular inability to acidify urine in the presence of test-induced systemic metabolic acidosis.
Results: Densitometric signs of osteoporosis were found in 82% of DRTA cases and in 83% of patients without DRTA (difference not significant). There were no significant differences in BMD measurement, T and Z scores of patients with and without DRTA.
Conclusions: The present study could not support a correlation between the presence of DRTA and the bone loss observed in PBC patients. 相似文献