全文获取类型
收费全文 | 11329篇 |
免费 | 707篇 |
国内免费 | 127篇 |
专业分类
耳鼻咽喉 | 195篇 |
儿科学 | 74篇 |
妇产科学 | 135篇 |
基础医学 | 2080篇 |
口腔科学 | 326篇 |
临床医学 | 940篇 |
内科学 | 1828篇 |
皮肤病学 | 452篇 |
神经病学 | 1048篇 |
特种医学 | 636篇 |
外科学 | 1565篇 |
综合类 | 35篇 |
一般理论 | 2篇 |
预防医学 | 457篇 |
眼科学 | 277篇 |
药学 | 1241篇 |
中国医学 | 153篇 |
肿瘤学 | 719篇 |
出版年
2024年 | 3篇 |
2023年 | 52篇 |
2022年 | 228篇 |
2021年 | 476篇 |
2020年 | 204篇 |
2019年 | 304篇 |
2018年 | 358篇 |
2017年 | 276篇 |
2016年 | 390篇 |
2015年 | 508篇 |
2014年 | 655篇 |
2013年 | 734篇 |
2012年 | 1051篇 |
2011年 | 983篇 |
2010年 | 627篇 |
2009年 | 530篇 |
2008年 | 744篇 |
2007年 | 733篇 |
2006年 | 646篇 |
2005年 | 558篇 |
2004年 | 449篇 |
2003年 | 384篇 |
2002年 | 314篇 |
2001年 | 218篇 |
2000年 | 188篇 |
1999年 | 129篇 |
1998年 | 59篇 |
1997年 | 45篇 |
1996年 | 31篇 |
1995年 | 27篇 |
1994年 | 20篇 |
1993年 | 17篇 |
1992年 | 34篇 |
1991年 | 31篇 |
1990年 | 31篇 |
1989年 | 22篇 |
1988年 | 16篇 |
1987年 | 16篇 |
1986年 | 8篇 |
1985年 | 8篇 |
1984年 | 10篇 |
1983年 | 3篇 |
1982年 | 4篇 |
1981年 | 4篇 |
1979年 | 7篇 |
1978年 | 5篇 |
1977年 | 5篇 |
1976年 | 5篇 |
1969年 | 2篇 |
1968年 | 3篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
871.
Renal biopsy in elderly patients: clinicopathological correlation in 117 Korean patients 总被引:1,自引:0,他引:1
Shin JH Pyo HJ Kwon YJ Chang MK Kim HK Won NH Lee HS Oh KH Ahn C Kim S Lee JS 《Clinical nephrology》2001,56(1):19-26
AIM: In the elderly with renal disease, the clinical presentations are frequently inconsistent with the pathologic findings. We tried to clarify the differences in pathological findings between the young and the elderly, in Korea and in Western countries, and the usefulness of a percutaneous renal biopsy in the elderly with renal disease. PATIENTS AND METHODS: We analyzed the clinical presentations and spectrums of renal histopathology by reviewing medical records and renal biopsy reports retrospectively in 117 Korean patients aged 60 years or more with renal disease. RESULTS: 85 patients had primary renal disease. The remaining 32 patients had renal diseases associated with systemic conditions. Out of the 85 patients with primary renal disease, 61 cases presented as idiopathic nephrotic syndrome. Compared with renal biopsy results of younger adult patients (age 15-59, n = 1,908), membranous nephropathy, crescentic glomerulonephritis, membranoproliferative glomerulonephritis, amyloidosis, light chain disease, and thrombotic thrombocytopenic purpura were more prevalent, but IgA nephropathy and lupus nephritis were less common in the elderly patients. In clinical presentation, nephrotic syndrome and rapidly progressive renal failure were more prevalent, but asymptomatic urinary abnormality was less common in elderly patients. The responsiveness to treatment was good in elderly patients with minimal-change lesion (complete remission in all patients) but poor in crescentic glomerulonephritis, IgA nephropathy, and membranoproliferative glomerulonephritis. From the above findings, the clinical presentation, patterns of histopathology and responsiveness to treatment of elderly Korean patients were similar to those of the younger Korean control group and the Western elderly group. CONCLUSION: Percutaneous renal biopsy is a useful diagnostic aid and can be used as a therapeutic guideline even in elderly patients with renal disease. 相似文献
872.
The methanolic extract of the aerial parts of Adenocaulon himalaicum (Asteraceae) has yielded a new acetylene, 1-O-feruloyl-tetradeca-4E,6E,12E-triene-8,10-diyne (1), a new monoterpene glycoside, 9-hydroxylinaloyl-3-O-(4-O-coumaroyl)-beta-D-glucopyranoside (2), and eight known compounds. Their structures were established by chemical and spectroscopic methods. 相似文献
873.
Lee Minhyung Nah Jae-Woon Kwon Youngmin Koh Jae Joon Ko Kyung Soo Kim Sung Wan 《Pharmaceutical research》2001,18(4):427-431
Purpose. Chitosan, a natural cationic polysaccharide, is a candidate non-viral vector for gene delivery because of its high positive charges and low cytotoxicity. In this study, low molecular weight chitosan (LMWC, molecular weight of 22 kDa) was characterized and evaluated as a gene carrier.
Methods. Plasmid/LMWC complex was analyzed in 1% agarose gel electrophoresis. To confirm that the LMWC protected plasmids from nuclease, DNase I protection assays were performed. pSV--galactosidase plasmid/LMWC complex was transfected into 293T cells and transfection efficiency was evaluated by -galactosidase assay. Cytotoxicity of LMWC was determined by MTT assay.
Results. Unlike high molecular weight chitosan (HMWC), LMWC is highly water soluble, and can form complex with plasmids in physiological buffer. The plasmid DNA was completely retarded at a weight ratio of 1:2 (plasmid:LMWC) in 1% agarose gel. DNase I protection assay showed that plasmids were protected from DNase I over 60 min. The most efficient transfection was obtained at a weight ratio of 1:3 (plasmid:LMWC). The transfection efficiency of LMWC was significantly higher than naked DNA and higher than poly-L-lysine (PLL). MTT assay showed that LMWC was less cytotoxic than PLL.
Conclusions. LMWC is non-toxic and has higher transfection efficiency than PLL. Therefore, LMWC will be useful in the development of safe gene carriers. 相似文献
874.
Bcl-2 overexpression attenuates resveratrol-induced apoptosis in U937 cells by inhibition of caspase-3 activity 总被引:7,自引:0,他引:7
Park JW Choi YJ Suh SI Baek WK Suh MH Jin IN Min DS Woo JH Chang JS Passaniti A Lee YH Kwon TK 《Carcinogenesis》2001,22(10):1633-1639
Resveratrol has been shown to induce anti-proliferation and apoptosis of human cancer cell lines. In the present study, we determined the effect of high intracellular levels of the anti-apoptosis protein Bcl-2 on caspase-3 activation, PLC-gamma1 degradation and cytochrome c release during resveratrol-induced apoptosis. For this, we used U937/vector and U937/Bcl-2 cells, which were generated by transfection of the cDNA of the Bcl-2 gene. As compared with U937/vector, U937/Bcl-2 cells exhibited a 4-fold greater expression of Bcl-2. Treatment with 60 or 100 microM resveratrol for 24 h produced morphological features of apoptosis and DNA fragmentation in U937/vector cells, respectively. This was associated with caspase-3 activation and PLC-gamma1 degradation. In contrast, resveratrol-induced caspase-3 activation and PLC-gamma1 degradation and apoptosis were significantly inhibited in U937/Bcl-2 cells. Bcl-2 overexpressing cells exhibited less cytochrome c release and sustained expression levels of the IAP proteins during resveratrol-induced apoptosis. In addition, these findings indicate that Bcl-2 inhibits resveratrol-induced apoptosis by a mechanism that interferes with cytochrome c release and activity of caspase-3 that is involved in the execution of apoptosis. 相似文献
875.
Patterns of temperament and character in subjects with obsessive-compulsive disorder 总被引:4,自引:0,他引:4
BACKGROUND: The purpose of this study was to assess the temperament and character patterns of obsessive-compulsive disorder (OCD) patients and to investigate the relationship between patterns of temperament and character and the severity of obsessive-compulsive symptoms. METHOD: The subjects were 40 patients who met DSM-IV criteria for OCD and 40 age-, sex-, and IQ-matched healthy controls. All subjects completed Cloninger's Temperament and Character Inventory. Other instruments included the Yale-Brown Obsessive Compulsive Scale, the Beck Depression Inventory, and the Beck Anxiety Inventory. RESULTS: OCD patients showed significantly higher scores of harm avoidance and lower scores of novelty seeking and self-directedness compared with healthy comparison subjects. In addition, the high harm avoidance and low self-directedness scores are correlated with a greater severity of obsessive-compulsive symptoms in OCD subjects (multiple regression analysis, beta = 0.39, t = 2.54, df = 34, p = .016; beta = -0.41, t = 2.46, df = 34, p = .019, respectively). CONCLUSION: OCD patients had distinct patterns of temperament and character compared with healthy comparison subjects. In addition, these patterns are specifically related to the severity of obsessive-compulsive symptoms. 相似文献
876.
Changes of skin blood flow and color on lesional and control sites during PUVA therapy for psoriasis 总被引:2,自引:0,他引:2
Suh DH Kwon TE Kim SD Park SB Kwon OS Eun HC Youn JI 《Journal of the American Academy of Dermatology》2001,44(6):987-994
BACKGROUND: Although the colors of psoriatic lesions, largely determined by erythema and scales, are important clinical indicators, expressing them in an objective manner is difficult. Cutaneous blood flow (CBF) also affects erythema. Serial measurement of these parameters during phototherapy was almost nonexistent. OBJECTIVE: The objectives of our study were to observe the changes of color parameters and the CBF of psoriatic lesions during PUVA therapy and to determine their clinical significance. METHODS: CBF, measured by laser Doppler flowmetry, and color parameters, measured by tristimulus colorimetry and reflectance spectrophotometry, were assessed in 13 patients with psoriasis who received PUVA therapy. RESULTS: The values of CBF, erythema index (EI), and a(*) (color parameter representing red-green axis) in psoriatic lesions were significantly different from those observed in the control sites before therapy. The parameters of psoriatic lesions normalized according to the clinical improvement and approached those of the control sites as PUVA therapy progressed. The values of melanin index (MI), L(*) (color parameter representing white-black axis), and b(*) (color parameter representing yellow-blue axis) showed no significant difference between the psoriatic plaques and the control sites. They all displayed changes toward darkening and indicated tanning induced by PUVA therapy. Serial changes presented a generally unidirectional pattern in the control sites. However, this was not always the case in psoriatic lesions because scale, infiltration, and erythema also affected the measurement of blood flow and the color of the skin. CONCLUSION: Color parameters and CBF were closely related with clinical improvement according to consecutive phototherapy. They may serve as objective indices for the visible morphology and underlying lesional pathophysiology of psoriasis. 相似文献
877.
We present the first case report of a suc-cessful laparoscopic complete excision of a splenic lymphangioma. The splenic tumor
was preoperatively diagnosed to be a lymphangioma by the combined modalities of ultrasonography, computed tomography, magnetic
resonance imaging, and angiography. A laparoscopic splenectomy was subsequently performed and the pathological examination
of the mass confirmed the diagnosis of a lymphangioma. Based on the above findings, a laparoscopic splenectomy is recommended
when a splenic tumor is suspected to be either benign or borderline.
Received: March 13, 2000 / Accepted: September 26, 2000 相似文献
878.
Ruptured Dissecting Aneurysm in Bilateral Iliac Arteries Caused by Ehlers-Danlos Syndrome Type IV: Report of a Case 总被引:1,自引:0,他引:1
Imamura A Nakamoto H Inoue T Yamada H Okuno M Takai S Komada H Kwon AH Kamiyama Y 《Surgery today》2001,31(1):85-89
Ehlers-Danlos syndrome (EDS) is an inherited disorder of connective tissue characterized by hyperextensible skin, hypermobile
joints, and ab-normalities of the cardiovascular system. Ten types and several subtypes of EDS have so far been recognized
based on genetic, clinical, and biochemical characteristics. The spectrum of the disorder varies from mild to life-threatening
vascular complications. EDS type IV is a particularly dangerous form with a lethal spontaneous rupture of the major arteries
and aneurysmal formation. We present herein a case of a ruptured dissecting aneurysm in the bilateral iliac arteries caused
by EDS type IV. A previously healthy 33-year-old man without any physical features of this connective tissue disorder experienced
a metachronous vascular rupture two times. Successful synthetic bypass grafting was performed with great difficulty. The diagnosis
of EDS type IV was made afterwards based on an electrophoresis analysis of a skin biopsy specimen which revealed a lack of
type III collagen. Surgical intervention in cases of arterial complications in EDS type IV patients have been reported to
be both difficult and frequently unsuccessful. The early clinical recognition of this syndrome is therefore of great importance
due to the hazards of such surgical therapies.
Received: November 16, 1999 / Accepted: July 25, 2000 相似文献
879.
Corepressor-induced organization and assembly of the biotin repressor: a model for allosteric activation of a transcriptional regulator 总被引:1,自引:0,他引:1 下载免费PDF全文
880.
A 54-year-old woman with diabetes mellitus was hospitalized with generalized edema and weakness. She was also found to have hypertension, hypokalemia and metabolic alkalosis. Detailed examination showed subnormal plasma renin activity and plasma aldosterone concentration. Adrenal CT scanning revealed no adrenal tumor. A successful treatment with amiloride established the diagnosis of Liddle's syndrome for the patient. Liddle's syndrome, a rare hereditary disease usually found in young patients, should be considered in the differential diagnosis of hypertension even in elderly individuals. 相似文献