全文获取类型
收费全文 | 87084篇 |
免费 | 9738篇 |
国内免费 | 3247篇 |
专业分类
耳鼻咽喉 | 369篇 |
儿科学 | 1717篇 |
妇产科学 | 960篇 |
基础医学 | 11004篇 |
口腔科学 | 570篇 |
临床医学 | 6914篇 |
内科学 | 13302篇 |
皮肤病学 | 756篇 |
神经病学 | 2448篇 |
特种医学 | 2904篇 |
外国民族医学 | 96篇 |
外科学 | 8465篇 |
综合类 | 14835篇 |
现状与发展 | 11篇 |
预防医学 | 3933篇 |
眼科学 | 391篇 |
药学 | 8875篇 |
42篇 | |
中国医学 | 3664篇 |
肿瘤学 | 18813篇 |
出版年
2024年 | 240篇 |
2023年 | 1268篇 |
2022年 | 2659篇 |
2021年 | 3623篇 |
2020年 | 3201篇 |
2019年 | 2937篇 |
2018年 | 2779篇 |
2017年 | 3238篇 |
2016年 | 3615篇 |
2015年 | 3706篇 |
2014年 | 5669篇 |
2013年 | 5837篇 |
2012年 | 5404篇 |
2011年 | 6189篇 |
2010年 | 5004篇 |
2009年 | 4857篇 |
2008年 | 4877篇 |
2007年 | 5200篇 |
2006年 | 4748篇 |
2005年 | 4210篇 |
2004年 | 3453篇 |
2003年 | 2897篇 |
2002年 | 2256篇 |
2001年 | 1955篇 |
2000年 | 1663篇 |
1999年 | 1265篇 |
1998年 | 1005篇 |
1997年 | 878篇 |
1996年 | 687篇 |
1995年 | 533篇 |
1994年 | 474篇 |
1993年 | 339篇 |
1992年 | 341篇 |
1991年 | 276篇 |
1990年 | 240篇 |
1989年 | 195篇 |
1988年 | 196篇 |
1987年 | 165篇 |
1986年 | 144篇 |
1985年 | 228篇 |
1984年 | 259篇 |
1983年 | 202篇 |
1982年 | 234篇 |
1981年 | 195篇 |
1980年 | 167篇 |
1979年 | 160篇 |
1978年 | 98篇 |
1977年 | 78篇 |
1976年 | 60篇 |
1975年 | 73篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
191.
目的分析肺癌骨转移引起腰腿痛症状导致误诊的原因及教训。方法对1例误诊为腰椎间盘突出症、腰臀部慢性软组织损害的肺癌骨转移致腰腿痛患者的诊疗过程结合文献进行综合分析。结果肺癌骨转移所致腰腿麻痛症状是因受累椎体发生溶骨性破坏或楔形变,对应椎管位置狭窄,肿瘤侵犯骨皮质或软组织肿块压迫刺激脊髓和神经根而引起,本病误诊的主要原因是病史询问不详,查体简单、粗疏,未做针对性强的影像学检查。结论仔细询问病史,认真查体,与早期行针对性强的影像学检查相结合,可有效降低误诊率。 相似文献
192.
193.
Naoya Katsuragi Yutsuki Nakajima Yuji Shiraishi Masahiro Hashizume Nobumasa Takahashi 《The Japanese Journal of Thoracic and Cardiovascular Surgery》2005,53(8):440-442
We describe a case of a large bronchial fistula and empyema after right upper lobectomy that was treated successfully with
open window thoracostomy followed by a latissimus dorsi myocutaneous flap and limited thoracoplasty. A latissimus dorsi myocutaneous
flap can provide immediate airtight closure of a large bronchial fistula, allowing lavage and curettage of the empyema cavity
to reduce the chance of postoperative infection. An important aspect of this technique is that the deepithelialized skin side
rather than muscle is sutured to an opening of the bronchus. As compared with other techniques, a latissimus dorsi myocutaneous
flap is superior in that it requires a single incision and does not require an intraop-erative change of position. In addition,
the technique causes little dysfunction of the chest and shoulder and preserves the vascular supply to ensure the viability
of the flap even if it was divided in a previous operation. 相似文献
194.
The Hemodynamic Mechanisms of Lung Injury and Systemic Inflammatory Response Following Brain Death in the Transplant Donor 总被引:7,自引:2,他引:5
Vassilios S. Avlonitis Christopher H. Wigfield John A. Kirby John H. Dark 《American journal of transplantation》2005,5(4):684-693
Brain-dead donors are the major source of lungs for transplantation. Brain death is characterized by two hemodynamic phases. Initially, massive sympathetic discharge results in a hypertensive crisis. This is followed by neurogenic hypotension. Up-regulation of pro-inflammatory mediators occurs in all organs and lung injury develops; this can adversely affect graft function post-transplantation. The mechanisms of the systemic and lung inflammation are unknown. We hypothesized that the hemodynamic changes are responsible for these inflammatory phenomena. Brain death was induced by intra-cranial balloon inflation in rats. This resulted in hypertensive crisis, followed by hypotension. There was a significant increase in blood neutrophil CD11b/CD18 expression and pro-inflammatory cytokine levels in serum and bronchoalveolar lavage, compared with control animals. Rupture of the capillary-alveolar membrane was demonstrated by electron microscopy. Elimination of the hypertensive response by α-adrenergic antagonist pre-treatment prevented inflammatory lung injury, reduced the systemic inflammatory markers and preserved capillary-alveolar membrane integrity. Correction of the neurogenic hypotension with noradrenaline ameliorated the systemic inflammatory response and improved oxygenation. We conclude that the sympathetic discharge triggers systemic and lung inflammation, which can be further enhanced by neurogenic hypotension. Management of the brain-dead donor with early anti-inflammatory treatment and vasoconstrictors is warranted. 相似文献
195.
A. L. Snow M. Vaysberg S. M. Krams O. M. Martinez 《American journal of transplantation》2006,6(5P1):976-985
Lymphomas associated with post-transplant lymphoproliferative disease (PTLD) represent a significant complication of immunosuppression in transplant recipients. In immunocompetent individuals, EBV-specific cytotoxic T lymphocytes (CTL) prevent the outgrowth of activated B lymphoblasts through apoptosis induction. Soluble versions of TNF-related apoptosis-inducing ligand/Apo2 ligand (TRAIL) can induce apoptosis in numerous tumor cell types. Given the therapeutic potential of TRAIL, we examined the sensitivity of EBV+ spontaneous lymphoblastoid cell lines (SLCL) derived from patients with PTLD to treatment with soluble TRAIL. Despite abundant expression of TRAIL receptors (TRAIL-R), resistance to TRAIL-induced apoptosis was observed in all SLCL examined. This resistance could not be overcome by concomitant treatment with several pharmacological agents. Unlike BJAB positive control cells, for each SLCL tested, cleavage and activation of caspase 8 was inhibited due to failed recruitment of FADD and caspase 8 to TRAIL receptors upon stimulation. Further indicative of a proximal defect, TRAIL receptor aggregation could not be detected on the cell surface of SLCL following ligand engagement. These results suggest that the use of TRAIL for eliminating PTLD-associated tumors may be of limited clinical utility, and illustrate another mechanism by which EBV+ B lymphoma cells can evade tumor surveillance at the level of death receptor signaling. 相似文献
196.
197.
目的 观察丝裂霉素C(MMC)与C2-神经酰胺(C2-cer)联合应用对人膀胱癌细胞的作用效果,并探讨其机制。方法 不同浓度MMC与C2-cer单独及联合作用于人膀胱癌BIU-87细胞后,应用噻唑蓝(MTT)比色法检测细胞生长抑制率,计算合用指数(CI),流式细胞仪(FCM)检测BIU-87细胞凋亡率,吖啶橙(AO)荧光染色观察凋亡形态学变化,Western blot检测细胞色素C在细胞内分布变化,并检测Caspase-3活性改变。结果 单独应用时MMC与C2-cer的中效浓度分别是159和28μmol/L,联合用药时下降为55和11μmol/L,CI=0.74。MMC与C2-cer单独及联合应用均可导致BIU-87细胞出现凋亡的形态学变化。两种药物联合应用时的凋亡率高于各自单用(P<0.05)。线粒体细胞色素C含量在MMC与C2-cer单独及联合应用时均较对照组减少,联合用药时减少最为明显,细胞质内细胞色素C含量在联合用药时增加也最为明显(P<0.05)。Caspase-3活性在MMC与C2-cer单独及联合应用时均较对照组升高,联合用药时升高最为明显(P<0.05)。结论 MMC与C2-cer联合应用可以通过共同诱导细胞凋亡,协同抑制膀胱癌细胞生长。线粒体细胞色素C释放和Caspase-3活性变化可能发挥重要作用。 相似文献
198.
蝎毒多肽提取物对肺癌荷瘤裸鼠血流变学的影响 总被引:2,自引:0,他引:2
目的观察蝎毒多肽提取物(PESV)对肺癌荷瘤裸鼠血流变学的影响。方法移植肺癌荷瘤裸鼠随机分为PESV组(皮下注射PESV)与对照组(皮下注射生理盐水)。采用FASCO-300型全自动表观黏度快测仪对两组的全血黏度进行检测。结果与对照组相比,PESV组血流变学指标均有不同程度的降低,尤其是全血低切表观黏度、全血高切表观黏度、Casson黏度、Casson屈服应力均明显低于对照组(P〈0.01)。结论PESV可降低荷瘤裸鼠血液黏度,对肺癌荷瘤裸鼠肿瘤转移能力有明显的抑制作用。 相似文献
199.
L. J. Dupont Y. Dewandeleer B. M. Vanaudenaerde D. E. Van Raemdonck G. M. Verleden 《American journal of transplantation》2006,6(6):1486-1492
Endogenous airway acidification, as assessed by the condensate pH, has been implicated in the pathophysiology of inflammatory airway diseases such as cystic fibrosis and asthma. The aim of this study was to investigate the pH of condensate in patients after lung transplantation (LTX). From the cohort of transplanted patients at our center, 83 patients (9 heart-lung transplantation, 48 double-lung transplantation, 26 single-lung transplantation) were recruited and analyzed in a cross-sectional manner: 26 patients were diagnosed with chronic rejection or bronchiolitis obliterans syndrome (BOS), 7 patients were diagnosed with acute rejection (AR) while 50 patients had no evidence of rejection according to the International Society for Heart and Lung Transplantation criteria. The condensate pH was significantly reduced in patients with BOS and AR when compared to patients without rejection and control subjects (5.8 +/- 0.5 and 6.2 +/- 0.4 versus 6.6 +/- 0.4 and 6.5 +/- 0 .4, respectively; p < 0.05). Moreover, there was a significant correlation between condensate pH levels and the BOS grade (r =-0.62; p < 0.01), the FEV(1) (r = 0.39; p < 0.01) and the total cell and neutrophil count in bronchoalveolar lavage fluid (r =-0.39 and r =-0.56, respectively; p < 0.01). Airway acidification occurs in BOS and may directly or indirectly reflect airway inflammation in patients with allograft rejection after LTX. Measuring condensate pH might thus be a new tool for the evaluation of rejection in lung transplant patients. 相似文献
200.
低剂量他克莫司治疗大鼠急性脊髓损伤的实验研究 总被引:2,自引:1,他引:1
目的:探讨低剂量他克莫司(tacrolimus,又名FK506)对大鼠急性脊髓损伤是否具有神经保护作用。方法:雄性Wistar大鼠72只,随机分为假手术组(12只)、损伤组(30只)和FK506治疗组(30只)。采用Allen’s打击法致伤大鼠T10脊髓,假手术组仅做椎板切除术。FK506治疗组在脊髓损伤后5min一次性经尾静脉注射FK5060.3mg/kg,其余两组以相同方法给予等量生理盐水。致伤后30min、6h、24h、48h、72h取伤段脊髓组织行病理观察及原位末端标记法(TUNEL)检测神经细胞凋亡,伤后1、3、7、14、21d行脊髓功能BBB评分和斜板实验。结果:伤后3、7、14、21d,FK506治疗组斜板实验和BBB评分明显优于损伤组,两组间比较差异有显著性(P〈0.05);伤后各时间点FK506治疗组脊髓损伤区出血坏死较损伤组轻;伤后6、24、48、72h神经细胞凋亡FK506治疗组较损伤组明显减少,两组间比较差异有显著性(P〈0.05)。结论:在大鼠急性脊髓损伤后早期应用低剂量他克莫司(0.3mg/kg)治疗对神经具有保护作用,可减少神经细胞凋亡,减轻脊髓继发性损伤,促进脊髓功能恢复。 相似文献