全文获取类型
收费全文 | 14555篇 |
免费 | 1187篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 159篇 |
儿科学 | 387篇 |
妇产科学 | 302篇 |
基础医学 | 1978篇 |
口腔科学 | 234篇 |
临床医学 | 1730篇 |
内科学 | 2834篇 |
皮肤病学 | 167篇 |
神经病学 | 1305篇 |
特种医学 | 401篇 |
外科学 | 1836篇 |
综合类 | 604篇 |
一般理论 | 5篇 |
预防医学 | 1663篇 |
眼科学 | 247篇 |
药学 | 857篇 |
中国医学 | 9篇 |
肿瘤学 | 1035篇 |
出版年
2023年 | 91篇 |
2022年 | 133篇 |
2021年 | 307篇 |
2020年 | 185篇 |
2019年 | 287篇 |
2018年 | 336篇 |
2017年 | 248篇 |
2016年 | 274篇 |
2015年 | 322篇 |
2014年 | 467篇 |
2013年 | 593篇 |
2012年 | 932篇 |
2011年 | 996篇 |
2010年 | 495篇 |
2009年 | 437篇 |
2008年 | 871篇 |
2007年 | 878篇 |
2006年 | 787篇 |
2005年 | 735篇 |
2004年 | 721篇 |
2003年 | 623篇 |
2002年 | 577篇 |
2001年 | 338篇 |
2000年 | 307篇 |
1999年 | 303篇 |
1998年 | 146篇 |
1997年 | 126篇 |
1996年 | 102篇 |
1995年 | 89篇 |
1994年 | 79篇 |
1993年 | 69篇 |
1992年 | 200篇 |
1991年 | 194篇 |
1990年 | 193篇 |
1989年 | 186篇 |
1988年 | 178篇 |
1987年 | 147篇 |
1986年 | 161篇 |
1985年 | 157篇 |
1984年 | 139篇 |
1983年 | 139篇 |
1982年 | 70篇 |
1980年 | 65篇 |
1979年 | 93篇 |
1978年 | 72篇 |
1976年 | 63篇 |
1974年 | 79篇 |
1973年 | 62篇 |
1971年 | 60篇 |
1970年 | 57篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
Blood flow of the areola and breast skin flaps during reduction mammaplasty as measured by laser Doppler flowmetry. 总被引:6,自引:0,他引:6
Blood flow changes during reduction mammaplasty were studied using laser Doppler flowmetry. Twenty-one patients (39 breasts) were entered into the study. Eight patients underwent a modified Skoog mammaplasty, 6 a central glandular pedicle mammaplasty, 2 an inferior pyramidal dermal flap mammaplasty, and 5 a glandular resection with free nipple grafts. Laser Doppler flowmetry was performed preoperatively, immediately postoperatively, 24 hours postoperatively, 48 hours postoperatively, and 2 weeks postoperatively. Laser Doppler flowmetry values (in milliliters per minute per 100 grams) measured at the areola declined by 23% (Skoog), 18% (central pedicle), and 21% (inferior pyramidal), in the immediate postoperative period. Values at 48 hours were 31% below baseline (Skoog), 14% below baseline (central pedicle), and 60% below baseline (inferior pyramidal). Values at 2 weeks postoperatively were 12% below baseline (Skoog), 2% above baseline (central pedicle), and 44% below baseline (inferior pyramidal). The free nipple grafts showed an 89% rise above baseline at 2 weeks. One patient's procedure was changed to a free nipple graft after a 92% Doppler flow reduction during a Skoog mammaplasty. The free nipple graft had the greatest blood flow. The central pedicle mammaplasty showed the least decline in areolar flow. The inferior pyramidal mammaplasty showed the greatest decline. Laser Doppler flowmetry is a clinically useful tool for monitoring intraoperative and postoperative nipple/areolar blood flow. 相似文献
32.
33.
Atul K. Sharma Moira S. Mills Vijay L. Grey Keith N. Drummond 《Pediatric nephrology (Berlin, Germany)》1997,11(6):711-713
Accurate, timed urine collections for the measurement of glomerular filtration rate (GFR) may be impractical in infants or
in patients with urological abnormalities. GFR may be measured without urine collection using a constant subcutaneous infusion
of iothalamate. We compare the infusion clearance with conventional renal clearance in 14 children and young adults. The mean
clearance ratio (infusion clearance/renal clearance ± 1 SD) was 0.99±0.1 and the mean discrepancy between the two methods
was 8.5%±4.7%. The 95% limits of agreement for the ratio of the two methods are 0.83–1.23. These data indicate that subcutaneous
infusion of iothalamate is a practical method for measuring GFR in children without a urine collection.
Received March 18, 1996; received in revised form February 12, 1997; accepted March 26, 1997 相似文献
34.
Annals of Behavioral Medicine - 相似文献
35.
Tracy A. Glauser 《Epilepsia》2004,45(S5):23-26
Summary: As patients with catastrophic epilepsies move from childhood to adulthood, evolving and innovative therapeutic regimens are often required. However, the goal of providing the best quality of life while minimizing both seizures and side effects remains the same. Clinicians can develop appropriate care plans by being aware of patients' changing needs. Clinical symptoms of the catastrophic epilepsies may change over time; by understanding the natural history of a patient's condition, clinicians can help ease the transition from childhood to adulthood. Additionally, as children with catastrophic epilepsies become adults, medical issues (e.g., medication side effects, tolerance, and dependence) and nonmedical issues (e.g., guardian/caretaker issue, group home applications, and respite care options) must be considered when developing strategies for patient care. Regular assessment of patients, the development of emergency plans, and maintenance of consistency in the delivery of care are also important issues to consider. Finally, a multidisciplinary care plan that incorporates resources from health-care practitioners, social service professionals, and community agencies can be valuable in optimizing treatment for patients with catastrophic epilepsies. 相似文献
36.
Two fast magnetic resonance (MR) imaging techniques, advanced Fourier and partial-flip imaging, were used at 0.35 T to examine 21 patients with suspected intracranial lesions; the results were quantitatively compared with a conventional spin-echo study. Both of the fast MR techniques yielded a fourfold reduction in imaging time per section. The advanced Fourier sequence showed contrast that was identical to the conventional spin-echo study with signal-to-noise ratios of 58% and 57% for the first and second echoes, respectively. The partial-flip sequence showed a contrast of 109% and 57% for lesions versus substantia alba, and 107% and 78% for substantia grisea versus substantia alba relative to the first and second echoes of the conventional spin-echo study. The partial-flip sequence was particularly sensitive to magnetic susceptibility; this produced artifacts that may undermine the usefulness of partial flip for routine screening in certain parts of the brain. However, this susceptibility significantly improved the detection of intracranial hemorrhage when compared with the spin-echo sequence, particularly when combined with phase mapping of the partial-flip study. 相似文献
37.
Alcoholism and dental management 总被引:1,自引:0,他引:1
A H Friedlander M J Mills D A Gorelick 《Oral surgery, oral medicine, and oral pathology》1987,63(1):42-46
Alcohol is widely used and abused in the United States. Because alcohol affects all parts of the body, it is important for dentists as well as all other medical practitioners to be aware of the signs of alcoholism. Some dental problems occur more frequently in alcoholic patients, and often general dental care for these patients must be modified. 相似文献
38.
Matthew Hoare Tracy Woodall Graeme J M Alexander 《Journal of interferon & cytokine research》2005,25(3):174-176
First-line therapy for hepatitis C virus (HCV) infection comprises interferon-alpha (IFN-alpha) and ribavirin for 6 or 12 months. Mild complications of therapy are common, but more serious complications are rare. Three patients with chronic HCV infection, acquired through injecting drug use, developed idiopathic facial paralysis (Bell's palsy) during therapy, with spontaneous resolution after withdrawal of treatment. Large-scale cohort studies reveal that IFNs are associated rarely with neurologic complications, and only one previous report has linked IFN-alpha therapy and Bell's palsy. We postulate that IFN-alpha therapy led to a breakdown of peripheral tolerance to myelin sheath antigens, leading to neuropathy, just as IFN-alpha therapy can cause autoimmune thyroiditis through breakdown of tolerance to native thyroid antigens. 相似文献
39.
40.
Human osteoclasts are well characterized multinucleated cells whose function is the directed resorption of normal bone (NB).
Osteoclastic bone destruction accompanies lytic solid tumors and myeloma as well as Paget's disease (PD) of bone and giant
cell tumors of bone (GCTB). The mechanism of this stimulation of osteoclastic bone resorption is unknown. This study was designed
to detect cytokines present in the multinucleated cells of PD and GCTB in order to determine whether cytokine abnormalities
exist to account for bone lysis. Nine cytokines, representing the functions of bone resorption, angiogenesis, tumor necrosis,
bone cell proliferation, and osteoblast–osteoclast coupling, were examined by immunohistochemistry using tissue samples from
15 NB, 17 PD, and 19 GCTB patients. Standard nonparametric statistical analysis showed a significant increase (P < 0.01 to 0.05) in immunostaining between osteoclasts of PD and NB for interleukin-6 (Il-6), tumor necrosis factor beta (TNFβ),
epidermal growth factor (EGF), platelet derived growth factor (PDGF), and basic fibroblast growth factor (bFGF). There was
a statistically significant decrease in immunostaining of giant cells of GCTB as compared with NB for transforming growth
factor beta (TGFβ), but no other differences from normal osteoclasts. The increase in staining of PD osteoclasts over the
giant cells of GCTB was significant (P < 0.01) for Il-6, TNFβ, PDGF, bFGF and insulin growth factor-1 (IGF-1), and (P < 0.05) for Il-1 and EGF. It was concluded that marked cytokine differences exist in vivo between osteoclasts of NB and PD lesions consistent with stimulated resorption. Alternatively, ``osteoclastoma' cells in
the center of the tumor did not overexpress the cytokines associated with bone lysis, suggesting some other mechanism for
stimulated resorption.
Received: 12 February 1996 / Accepted 31 December 1996 相似文献