全文获取类型
收费全文 | 25054篇 |
免费 | 1490篇 |
国内免费 | 282篇 |
专业分类
耳鼻咽喉 | 453篇 |
儿科学 | 368篇 |
妇产科学 | 409篇 |
基础医学 | 3873篇 |
口腔科学 | 458篇 |
临床医学 | 1967篇 |
内科学 | 4740篇 |
皮肤病学 | 1076篇 |
神经病学 | 1671篇 |
特种医学 | 1820篇 |
外科学 | 3532篇 |
综合类 | 94篇 |
一般理论 | 2篇 |
预防医学 | 1077篇 |
眼科学 | 696篇 |
药学 | 2177篇 |
中国医学 | 333篇 |
肿瘤学 | 2080篇 |
出版年
2023年 | 161篇 |
2022年 | 557篇 |
2021年 | 853篇 |
2020年 | 442篇 |
2019年 | 624篇 |
2018年 | 724篇 |
2017年 | 577篇 |
2016年 | 906篇 |
2015年 | 1321篇 |
2014年 | 1521篇 |
2013年 | 1703篇 |
2012年 | 2411篇 |
2011年 | 2286篇 |
2010年 | 1472篇 |
2009年 | 1200篇 |
2008年 | 1571篇 |
2007年 | 1412篇 |
2006年 | 1259篇 |
2005年 | 1202篇 |
2004年 | 971篇 |
2003年 | 835篇 |
2002年 | 721篇 |
2001年 | 278篇 |
2000年 | 283篇 |
1999年 | 218篇 |
1998年 | 138篇 |
1997年 | 94篇 |
1996年 | 71篇 |
1995年 | 55篇 |
1994年 | 49篇 |
1993年 | 45篇 |
1992年 | 73篇 |
1991年 | 69篇 |
1990年 | 58篇 |
1989年 | 46篇 |
1988年 | 50篇 |
1987年 | 43篇 |
1986年 | 52篇 |
1985年 | 53篇 |
1984年 | 44篇 |
1983年 | 52篇 |
1982年 | 21篇 |
1981年 | 18篇 |
1980年 | 19篇 |
1979年 | 29篇 |
1978年 | 27篇 |
1977年 | 24篇 |
1976年 | 23篇 |
1974年 | 18篇 |
1973年 | 25篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
41.
Thyroid-vitamin A interactions in chicks exposed to 3,4,3',4'-tetrachlorobiphenyl: influence of low dietary vitamin A and iodine 总被引:1,自引:0,他引:1
Poultry chicks receiving a low vitamin A semipurified diet and exposed to 3,4,3',4'-tetrachlorobiphenyl became hypothyroid in comparison with unexposed controls. Metabolic rate, total serum thyroxine, total serum triiodothyronine, and food intake decreased significantly while thyroid weight increased. Unexpectedly, growth rate was not affected on this diet. In the case of chicks receiving a low vitamin A--low iodine semipurified diet and exposed to the PCB congener, the hypothyroid response was apparently antagonized. Comparing exposed chicks with unexposed controls, metabolic rate and the proportion of free T3 (i.e., %T3 resin uptake) increased while total serum thyroxine and thyroid weight were unchanged. In addition, growth rate, food consumption, and serum retinol decreased on this diet. These results are interpreted to mean that growth rate may have been altered by circulating levels of retinol, and vitamin A insufficiency may predispose birds to the hypothyroid effects of PCBs. 相似文献
42.
A case of a paraffinoma in the urinary bladder is presented. Plain radiography and intravenous urography showed a low attenuation filling defect in the urinary bladder, and CT demonstrated a lobulated fat-attenuation mass floating in the urinary bladder. 相似文献
43.
The relationship of the extrinsic blood supply to regeneration in graft reconstructed peripheral nerves 总被引:3,自引:0,他引:3
A F Cook H K Moon M P Lynn D Margolin E Z Browne 《British journal of plastic surgery》1988,41(3):298-304
Median nerves of rats were reconstructed with conventional or vascular nerve grafts. After 2, 3 and 4 weeks, Allen Video-Enhanced Contrast, Differential Interference Contrast (AVEC-DIC) microscopy revealed axonal transport in most preparations, with varying degrees of myelination. Radio-isotope tracer was measured in the nerve. Two and 4 week measurements revealed no difference between the graft types. At 3 weeks the vascular graft group exhibited transport along the entire length of the nerve in contrast to a relatively abbreviated path length in the conventional graft group. Nerve conduction velocities (NCV) were measured proximal to, within and distal to the grafts. Three week NCV showed no difference between the graft types. The 4 week NCV revealed normal values in the vascular graft group at points distal to and within the graft. Significant slowing was seen in the conventional grafts at both points. 相似文献
44.
Kyung‐Sub Moon Shin Jung Jae‐Hyuk Lee Tae‐Young Jung In‐Young Kim Soo‐Han Kim Sam‐Suk Kang 《Neuropathology》2006,26(2):141-146
We present a case of benign osteoblastoma of the occipital bone. Benign osteoblastoma is an uncommon primary bone tumor, which usually involves the vertebrae and the long bones. This tumor rarely develops in the calvaria, showing a preference for the temporal and frontal bones when it does. To the best of our knowledge, this case is only the eighth reported case of benign osteoblastoma confined to the occipital bone. A 20‐year‐old male presented with a mild tender mass lesion of the occipital area, just below the lambda. Plain X‐ray films and CT scans demonstrated an osteolytic mass surrounded by the sclerotic rim within the diploic space. MRI proved to be effective for the evaluation of the intracranial and intraosseous extensions of the tumor. However, it was very difficult to formulate a differential diagnosis against other osteoblastic tumors, or osteoid osteoma, in view of its radiological appearance. The final diagnosis was obtained by careful consideration of the histopathological characteristics of the tumor combined with its clinical and radiological features. Although generally regarded as benign, a complete resection is preferred over conventional curettage as this can guard against possible recurrence and malignant transformation. 相似文献
45.
Seung Min Lee Seung Kyung Hann Soo II Chun Seung Hung Lee Yoon-Kee Park 《The Journal of dermatology》1994,21(2):106-110
A 25-year-old female has had brown to erythematous telangiectatic patches and grouped papules on her face, neck, arm, and trunk since childhood following B.C.G. vaccination. Histopathologically, the lesions consisted of hyperkeratosis, slight acanthosis, tuberculoid granulomas with some Langerhans type giant cells in the mid-dermis. Although various forms of cutaneous tuberculosis after B.C.G. vaccination have been reported, it was difficult for us to assign the patient's skin lesion to any specific disease entity. Remission of her cutaneous lesions occurred clinically and histopathologically after treatment with isoniazid and rifampin. 相似文献
46.
Metabolic consequences of hypercapnia in the rainbow trout, Salmo gairdneri: beta-adrenergic effects
The metabolic consequences of external hypercapnia (1% CO2) were assessed in rainbow trout (Salmo gairdneri) in the presence or absence of circulating levels of the beta adrenoceptor antagonist, propranolol. External hypercapnia caused a severe extracellular respiratory acidosis and a less pronounced reduction of hepatic intracellular pH (pHi). pHi was restored to prehypercapnic values after 48 hr of continuous hypercapnia due to elevation of bicarbonate levels. In the presence of propranolol, hypercapnia elicited a pronounced activation of pyruvate kinase (PyK) (measured at both low and high phosphoenolpyruvate (PEP) concentrations) and inactivation of both total glycogen phosphorylase (GPase) and glycogen phosphorylase a (GPase a). In the absence of propranolol, the changes in enzyme activities were significantly reduced (low PEP PyK activity) or totally absent (GPase inactivation). These results suggest that beta adrenoceptor-mediated phenomena offset disruptive effects of hypercapnia on PyK and GPase activities and may be important in the control of gluconeogenesis and glycogenolysis during this acid-base disturbance. The adrenergic effects were not related to modification of hepatic intracellular acid-base status. Hypercapnia induced a rapid depletion of liver glycogen and concomitant hyperglycemia. These effects were not prevented by pretreating fish with propranolol and appeared to be unrelated to changes in GPase a activity. These results suggest that factors other than adrenergic activation of GPase a are involved in the enhancement of liver glycogenolysis. 相似文献
47.
48.
Infracture Technique for the zygomatic body and arch reduction 总被引:2,自引:0,他引:2
In the Orient, prominent malar regions are considered unaesthetic and the majority of women with a prominent malar want to reduce the zygoma. Various operative procedures such as shaving or chiseling the zygomatic body or the zygomatic arch have been used for reducing malar eminence, but the zygomatic arch cannot be reduced sufficiently by these methods. By combining intraoral shaving of the zygomatic body and a new effect arch infracture technique through a temporopreauricular incision, we have obtained very satisfactory results in 19 cases and notable minimal complications over the last three years. 相似文献
49.
50.
Hyun Chul Kim Sang Woo Nam Yong Keun Cho Hey Jin Jeong Se In Kim Seong Hun Kim Chul Min An In Hee Kim Sang Wook Kim Seung Ok Lee Soo Teik Lee 《Taehan Sohwagi Hakhoe chi》2006,47(3):233-237
Although adenocarcinoma is a well known complication of chronic inflammatory bowel disease, primary gastrointestinal lymphoma occurring in Crohn's disease is rare. A 40-year-old man with 10 year-history of Crohn's disease had multiple longitudinal ulcerative lesions on descending colon in follow-up colonoscopic examination. Microscopic examination of proximal descending colon revealed peripheral T cell lymphoma and other site of the descending colon was consistent with Crohn's disease. The patient reached complete remission of malignant lymphoma after three cycles of combined chemotherapy. He has been well for 10 months with sulfasalazine maintenance therapy but was admitted to the hospital due to spontaneous bowel perforation of ascending colon. Right hemicolectomy was done, but the patient died of post-surgical recurrent mesenteric abscess and sepsis. To the best of our knowledge, this is the first case of Non-Hodgkin's lymphoma complicating Crohn's disease in Korea which was confirmed by immunohistochemical studies. 相似文献