全文获取类型
收费全文 | 2680篇 |
免费 | 131篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 28篇 |
儿科学 | 86篇 |
妇产科学 | 49篇 |
基础医学 | 288篇 |
口腔科学 | 49篇 |
临床医学 | 295篇 |
内科学 | 761篇 |
皮肤病学 | 51篇 |
神经病学 | 198篇 |
特种医学 | 170篇 |
外科学 | 306篇 |
综合类 | 9篇 |
预防医学 | 123篇 |
眼科学 | 28篇 |
药学 | 146篇 |
中国医学 | 4篇 |
肿瘤学 | 234篇 |
出版年
2022年 | 23篇 |
2021年 | 43篇 |
2020年 | 25篇 |
2019年 | 22篇 |
2018年 | 29篇 |
2017年 | 28篇 |
2016年 | 36篇 |
2015年 | 48篇 |
2014年 | 70篇 |
2013年 | 87篇 |
2012年 | 138篇 |
2011年 | 140篇 |
2010年 | 78篇 |
2009年 | 54篇 |
2008年 | 120篇 |
2007年 | 134篇 |
2006年 | 119篇 |
2005年 | 119篇 |
2004年 | 151篇 |
2003年 | 140篇 |
2002年 | 127篇 |
2001年 | 57篇 |
2000年 | 72篇 |
1999年 | 65篇 |
1998年 | 31篇 |
1997年 | 25篇 |
1996年 | 29篇 |
1995年 | 20篇 |
1994年 | 27篇 |
1993年 | 24篇 |
1992年 | 66篇 |
1991年 | 58篇 |
1990年 | 62篇 |
1989年 | 59篇 |
1988年 | 52篇 |
1987年 | 51篇 |
1986年 | 44篇 |
1985年 | 45篇 |
1984年 | 32篇 |
1982年 | 19篇 |
1979年 | 22篇 |
1978年 | 16篇 |
1977年 | 16篇 |
1975年 | 15篇 |
1974年 | 14篇 |
1971年 | 19篇 |
1970年 | 15篇 |
1969年 | 15篇 |
1968年 | 17篇 |
1966年 | 23篇 |
排序方式: 共有2825条查询结果,搜索用时 0 毫秒
31.
Idiopathic hypertrophic cranial pachymeningitis associated with a dural arteriovenous fistula involving the straight sinus: case report 总被引:2,自引:0,他引:2
OBJECTIVE AND IMPORTANCE: Reports of idiopathic hypertrophic cranial pachymeningitis have increased as a result of advances in magnetic resonance imaging. This is the first documented case of idiopathic hypertrophic cranial pachymeningitis associated with a dural arteriovenous fistula involving the straight sinus. We discuss possible causes of the association and the treatment options. CLINICAL PRESENTATION: A 64-year-old man presented with a headache and visual disturbance. Gadolinium-enhanced T1-weighted magnetic resonance imaging demonstrated homogeneously stained meninges and prominent enhancement of the tentorium and falx. Angiograms demonstrated a dural arteriovenous fistula of the straight sinus. INTERVENTION: Although surgical excision of the straight sinus and subsequent corticosteroid therapy failed to relieve the patient's visual symptoms, subsequent surgical decompression of the optic nerve resulted in improvement and stabilization. CONCLUSION: Narrowing or occlusion of the tentorial sinuses and narrowing of the straight sinus by extensive dural fibrosis of the tentorium and falx, attributable in turn to idiopathic hypertrophic cranial pachymeningitis, may have resulted in the development of a dural arteriovenous fistula. We propose surgical decompression of the optic nerve as an alternative treatment during the active phase of the disease in patients who exhibit resistance to corticosteroid therapy. 相似文献
32.
BACKGROUND AND OBJECTIVE: Recalcitrant molluscum contagiosum (MC) in patients with acquired immunodeficiency syndrome (AIDS) is usually difficult to treat. We present a case treated by a combination of CO(2) laser, trichloroacetic acid, and the 585-nm pulsed dye laser (PDL). The purpose was to determine the effectiveness and ease of these treatment modalities. STUDY DESIGN/MATERIALS AND METHODS: A patient with AIDS presented with recalcitrant MC lesions, predominantly located on the face. The lesions were first treated with the CO(2) laser, in two sessions. Recurrent lesions were treated either with 50% trichloroacetic acid (TCA) or with the PDL. RESULTS: The CO(2) laser treated lesions healed within 2 weeks without secondary infection. The PDL and the TCA treated lesions resolved completely after one treatment. CONCLUSION: Treatment of MC in AIDS patients remains a challenge. The combination of two or more therapeutic modalities, such as CO(2) laser, PDL, and TCA can be of great help to improve the quality of life of these patients. 相似文献
33.
Tetsuro Higuchi Takeo Iwama Keigo Yoshinaga Masahiro Toyooka Makoto M Taketo Kenichi Sugihara 《Clinical cancer research》2003,9(13):4756-4760
PURPOSE: The aim of this study was to examine the effect of a specific cyclooxygenase-2 inhibitor, rofecoxib, on rectal polyps in familial adenomatous polyposis patients. EXPERIMENTAL DESIGN: This was a randomized, double-blind, placebo-controlled study of the efficacy and safety of rofecoxib in the rectum. Initially, 21 patients were assigned randomly in a 1:1 ratio to receive either 25 mg rofecoxib once a day or a placebo p.o. for 9 months. Patients underwent endoscopy at the beginning of the study and then every 3 months thereafter. We reviewed the videotapes to measure the number and size of polyps in the same area throughout the study period in each individual patient. RESULTS: The polyp number, measured as the percentage of change from the baseline values, was significantly decreased in the rofecoxib group at 3, 6, and 9 months. At 9 months, the polyp number in the rofecoxib group decreased by 6.8% from the baseline values, whereas that in the placebo group increased by 3.1%. The 9.9% difference between the rofecoxib and placebo groups was statistically significant (P = 0.004). At 9 months, the rofecoxib group showed a significant reduction from the baseline in polyp size as compared with the placebo group (-16.2% versus 1.5%; P < 0.001). There was no statistically significant increase in the incidence of any adverse events in treatment with rofecoxib compared with placebo (P = 0.922). CONCLUSIONS: In this study, once-daily treatment with 25 mg rofecoxib, a cyclooxygenase 2-specific inhibitor, significantly decreased the number and size of rectal polyps in familial adenomatous polyposis patients. 相似文献
34.
Undifferentiated pancreatic cancer associated with humoral hypercalcemia of malignancy 总被引:1,自引:1,他引:1
Kakizaki S; Ohya N; Yoshinaga T; Higuchi T; Kitazawa R; Takayama H; Takagi H; Nagamine T; Mori M 《Japanese journal of clinical oncology》1998,28(9):563-566
We present a case of undifferentiated pancreatic cancer associated with
humoral hypercalcemia of malignancy (HHM) in which parathyroid
hormone-related protein (PTH-rP) is identified as the causative factor of
hypercalcemia. A 61-year-old man was hospitalized with right
hypochondralgia. Ultrasound examination and computed tomography
demonstrated a large mass in the pancreatic head with liver metastases.
Biopsy of the pancreatic tumor demonstrated undifferentiated carcinoma.
Serum calcium level and PTH-rP were elevated. Bone scan with technetium-99
demonstrated no accumulation in the bones. Immunohistochemical staining for
PTH-rP was weakly positive in the tumor cells. We considered that PTH-rP
was the causative factor of HHM in this case from laboratory data and
immunohistochemical findings. This rare case was successfully treated with
pamidronate disodium, which is a type of bisphosphonate derivative. We
compared this case with previously reported cases.
相似文献
35.
为了检测妇女绝经后发生骨量减少的相关指标进而倡导依据生活方式的特点对绝经后妇女骨质疏松的发生采取相应的预防和护理方针,我们对日本乡村的绝经后妇女(末次月经后六个月或更长时间算起)进行了为期4a的随访。我们运用双能X线骨密度仪(DXA)对腰椎骨密度(BMD)进行检测并对各种变量,包括年龄、绝经时的年龄、骨折史、日常摄奶量以及吸烟习惯进行多元分析,结果表明这些因素对于腰椎骨密度(BMD)的恢复是不相关联的。
在这些变量中,骨折史被证明对于相关人群是最具危险性的,这些对象有高比例的骨量减少(6.6%),其次是不规律的摄奶(13.6%)和吸烟(9.3%)。在护理中使用的作用于足跟骨的检测骨密度的设备被证实与作用于腰椎的DXA设备可以相互替代。依据这些结果,针对居住在日本乡村的绝经后妇女制订了相应的预防骨质疏松的方针。这些卫生指导方针依据特定区域的生活方式而制定并可适用于其他的人群和区域。在本文中,作者列出了不同的有助于预防绝经后妇女出现骨质疏松的方法并进行了调查。 相似文献
36.
Kiyokazu Takebayashi Yoshimoto Sekine Nori Takei Yoshio Minabe Haruo Isoda Hiroyasu Takeda Katsuhiko Nishimura Kazuhiko Nakamura Katsuaki Suzuki Yasuhide Iwata Harumi Sakahara Norio Mori 《Neuropsychopharmacology》2004,29(5):1019-1026
Long-term toluene abuse causes a variety of psychiatric symptoms. However, little is known about abnormalities at the neurochemical level in the living human brain after long-term exposure to toluene. To detect neurochemical changes in the basal ganglia of subjects with a history of long-term toluene use, proton magnetic resonance spectroscopy (1H MRS) was performed in 12 abstinent toluene users and 13 healthy comparisons with no history of drug abuse. N-acetylaspartate (NAA), creatine plus phosphocreatine (Cr + PCr), choline-containing compounds (Cho), and myo-inositol (MI) levels were measured in the left and right basal ganglia. The Cho/Cr + PCr ratio, a marker of membrane metabolism, was significantly increased in the basal ganglia of toluene users in comparison to that of the control subjects. Furthermore, the increase in the Cho/Cr + PCr ratio was significantly correlated with the severity of residual psychiatric symptoms. These findings suggest that long-term toluene use causes membrane disturbance in the basal ganglia, which is associated with residual psychiatric symptoms that persist even after long-term abstinence from toluene use. 相似文献
37.
目的测量鼻息肉(nasal polyps,NP)组织细胞核中活化的糖皮质激素受体(glucocorticoid receptor,GR)蛋白水平。方法应用ELlSA方法定量测定NP组织细胞核内活化的GR的蛋白水平。NP组织从不并发支气管哮喘和并发支气管哮喘的(chronic rhinosinusitis,CRS)伴NP患者中取得。在后者,NP组织在(glucocorticoid,Glu)治疗前和治疗后分次取得。结果不并发支气管哮喘和并发支气管哮喘Glu治疗前的CRS伴NP患者中,活化GR蛋白水平没有显著性差异。Glu治疗后,GIu蛋白水平较治疗前显著增高。结论Glu上调NP组织细胞核内活化的GR蛋白水平,这对于发挥Glu的抗炎作用至关重要。 相似文献
38.
Watanabe N Arai H Nishihara Y Taniguchi M Watanabe N Hunter T Osada H 《Proceedings of the National Academy of Sciences of the United States of America》2004,101(13):4419-4424
Wee1, the Cdc2 inhibitory kinase, needs to be down-regulated at the onset of mitosis to ensure rapid activation of Cdc2. Previously, we have shown that human somatic Wee1 (Wee1A) is down-regulated both by protein phosphorylation and degradation, but the underlying mechanisms had not been elucidated. In the present study, we have identified the beta-transducin repeat-containing protein 1/2 (beta-TrCP1/2) F-box protein-containing SKP1/Cul1/F-box protein (SCF) complex (SCF(beta-TrCP1/2)) as an E3 ubiquitin ligase for Wee1A ubiquitination. Although Wee1A lacks a consensus DS(p)GXXS(p) phospho-dependent binding motif for beta-TrCP, recognition of Wee1A by beta-TrCP depended on phosphorylation, and two serine residues in Wee1A, S53 and S123, were found to be the most important phosphorylation sites for beta-TrCP recognition. We have found also that the major M-phase kinases polo-like kinase 1 (Plk1) and Cdc2 are responsible for the phosphorylation of S53 and S123, respectively, and that in each case phosphorylation generates an unconventional phospho-degron (signal for degradation) that can be recognized by beta-TrCP. Phosphorylation of Wee1A by these kinases cooperatively stimulated the recognition and ubiquitination of Wee1A by SCF(beta-TrCP1/2) in vitro. Mutation of these residues or depletion of beta-TrCP by small-interfering RNA treatment increased the stability of Wee1A in HeLa cells. Moreover, our analysis indicates that beta-TrCP-dependent degradation of Wee1A is important for the normal onset of M-phase in vivo. These results also establish the existence of a feedback loop between Cdc2 and Wee1A in somatic cells that depends on ubiquitination and protein degradation and ensures the rapid activation of Cdc2 when cells are ready to divide. 相似文献
39.
BACKGROUND: Chemical speciation analysis is essential for the biological monitoring of inorganic arsenic exposure using urine as indicator medium. There is increasing demand for a certified reference material (CRM) of urine matrix for arsenic speciation. METHODS: Urine (10 L) was collected from non-occupationally exposed Japanese males. We prepared 954 bottles of urine, each containing approximately 10 mL, after filtering and blending the urine stock. The urine in each bottle was freeze-dried. Between-bottle homogeneity was confirmed by measuring the concentrations of selected minor and trace elements in the material and subsequent statistical analysis. Certification was based on a collaborative analysis involving 15 laboratories. RESULTS: Certified values were determined for arsenobetaine (0.069+/-0.012 mg As/L), dimethylarsinic acid (0.036+/-0.009 mg As/L), and total arsenic (0.134+/-0.011 mg/L) as well as for total selenium (0.059+/-0.005 mg/L) and zinc (0.62+/-0.05 mg/L), based on the analytical values from the collaborating laboratories. Reference values are given for copper (0.010 mg/L) and lead (0.0011 mg/L), based on definitive analysis at the National Institute for Environmental Studies (NIES). CONCLUSIONS: The present CRM, NIES CRM No. 18 Human Urine, is the first human urine CRM for arsenic speciation and will be of value for analytical quality assurance of the biological monitoring of arsenic exposure. 相似文献
40.