全文获取类型
收费全文 | 3848篇 |
免费 | 239篇 |
国内免费 | 18篇 |
专业分类
耳鼻咽喉 | 18篇 |
儿科学 | 84篇 |
妇产科学 | 39篇 |
基础医学 | 520篇 |
口腔科学 | 71篇 |
临床医学 | 302篇 |
内科学 | 824篇 |
皮肤病学 | 128篇 |
神经病学 | 481篇 |
特种医学 | 192篇 |
外科学 | 613篇 |
综合类 | 17篇 |
一般理论 | 1篇 |
预防医学 | 230篇 |
眼科学 | 72篇 |
药学 | 228篇 |
中国医学 | 3篇 |
肿瘤学 | 282篇 |
出版年
2023年 | 15篇 |
2022年 | 27篇 |
2021年 | 58篇 |
2020年 | 48篇 |
2019年 | 61篇 |
2018年 | 69篇 |
2017年 | 44篇 |
2016年 | 66篇 |
2015年 | 87篇 |
2014年 | 117篇 |
2013年 | 169篇 |
2012年 | 266篇 |
2011年 | 262篇 |
2010年 | 131篇 |
2009年 | 142篇 |
2008年 | 250篇 |
2007年 | 208篇 |
2006年 | 238篇 |
2005年 | 181篇 |
2004年 | 184篇 |
2003年 | 192篇 |
2002年 | 181篇 |
2001年 | 105篇 |
2000年 | 83篇 |
1999年 | 99篇 |
1998年 | 68篇 |
1997年 | 38篇 |
1996年 | 30篇 |
1995年 | 30篇 |
1994年 | 16篇 |
1993年 | 18篇 |
1992年 | 44篇 |
1991年 | 45篇 |
1990年 | 42篇 |
1989年 | 49篇 |
1988年 | 31篇 |
1987年 | 46篇 |
1986年 | 33篇 |
1985年 | 37篇 |
1984年 | 36篇 |
1983年 | 26篇 |
1981年 | 11篇 |
1980年 | 22篇 |
1979年 | 23篇 |
1978年 | 12篇 |
1977年 | 16篇 |
1976年 | 18篇 |
1975年 | 18篇 |
1969年 | 8篇 |
1966年 | 8篇 |
排序方式: 共有4105条查询结果,搜索用时 46 毫秒
71.
72.
3D matrix‐embedding inhibits cycloheximide‐mediated sensitization to TNF‐alpha‐induced apoptosis of human endothelial cells
下载免费PDF全文
![点击此处可从《Journal of tissue engineering and regenerative medicine》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Michael Saemisch Markus Nickmann Lisa Riesinger Elazer R. Edelman Heiko Methe 《Journal of tissue engineering and regenerative medicine》2018,12(4):1085-1096
The programmed form of cell death (apoptosis) is essential for normal development of multicellular organisms. Dysregulation of apoptosis has been linked with embryonal death and is involved in the pathophysiology of various diseases. Others and we previously demonstrated endothelial biology being intertwined with biochemical and structural composition of the subendothelial basement membrane. We now demonstrate that a three‐dimensional growing environment significantly shields endothelial cells from cytokine‐induced apoptosis. Detailed analysis reveals differences in intracellular signaling pathways in naive endothelial cells and cytokine‐stimulated endothelial cells when cells are grown within a three‐dimensional collagen‐based matrix compared to cells grown on two‐dimensional tissue culture plates. Main findings are significantly reduced p53 expression and level of p38‐phosphorylation in three‐dimensional grown endothelial cells. Despite similar concentrations of focal adhesion kinase, three‐dimensional matrix‐embedded endothelial cells express significantly less tyrosine‐phosphorylated focal adhesion kinase. Pretreatment with antibodies against integrin αvβ3 partially reversed the protective effect of three‐dimensional matrix‐embedding on endothelial apoptosis. Our findings provide detailed insights into the mechanisms of endothelial apoptosis with respect to the spatial matrix environment. These results enhance our understanding of endothelial biology and may otherwise help in the design of tissue‐engineered materials. Furthermore, findings on focal adhesion kinase phosphorylation might enhance our understanding of clinical studies with tyrosine kinase inhibitors. 相似文献
73.
Angelo Brandelli Costa Anna Martha Vaitses Fontanari Michelle Moraes Jacinto Dhiordan Cardoso da Silva Emilaine Karine Lorencetti Heitor Tomé da Rosa Filho Andressa Mueller Claudia Garcia de Garcia Henrique Caetano Nardi Silvia Helena Koller Maria Inês Rodrigues Lobato 《Archives of sexual behavior》2015,44(2):521-524
74.
Patrick T. Koller Mark Freed Cindy L. Grines William W. O'Neill 《Catheterization and cardiovascular interventions》1994,31(4):255-260
Our objectives were to determine procedural success, clinical complications, and follow-up restenosis rates after rotational burr and transluminal extraction atherectomy of coronary artery and saphenous vein graft ostial stenoses. Balloon angioplasty of ostial lesions has been associated with low rates of success and high rates of clinical complications and restenosis compared to nonostial lesions. Atherectomy, due to its ability to excise (extraction atherectomy) or pulverize (rotational atherectomy) atheroma and the internal elastic lamina, may result in improved procedural outcome. We retrospectively studied 101 patients with ostial stenoses treated by rotational burr and transluminal extraction atherectomy over a 3-yr period. Quantitative angiography and clinical follow-up were reviewed to determine success, complication, and restenosis rates. Rotational burr (n = 29) and transluminal extraction (n = 72) atherectomy were associated with high procedural success (93% and 90%, respectively) and a low incidence of complications (6.9% and 4.2%, respectively). Postatherectomy angiographic success was low (52% and 69%, respectively) and required adjunctive balloon angioplasty in 85% of patients overall. This lower success rate likely reflects device undersizing as the overall postatherectomy artery to device ratio was near unity (0.95). The rates of angiographic ostial restenosis remain high (39.1% and 65.9%, respectively, P < 0.05). The high rate of restenosis after transluminal extraction atherectomy was due to the higher rate of restenosis in saphenous vein grafts (80%) compared to TEC treated coronary arteries (59%). When only coronary artery lesions were compared, there was no significant difference between atherectomy device groups with respect to restenosis rates or late loss. Rotational or transluminal extraction atherectomy of ostial stenoses is associated with high procedural success rates and a low incidence of complications; however, the rates of restenosis in these lesions remain high. 相似文献
75.
2 methods for the implantation of permanent pacemakers with percutaneous puncture of the subclavian vein are described. The first one was used in 44 patients with the aid of an introducing catheter-set Desilets-Hoffman consisting of guide-wire, inner Teflon dummy catheter and outer thin-walled sheath; through this a shoulder-less electrode catheter no. 8 could be inserted for permanent pacing. The other technique was applied to 20 patients and used thinner special electrodes no. 6F, which could be introduced directly through a plastic cannula inserted with a puncture-needle. The advantages are: diminished risk of infections, local anesthesia instead of general anesthesia, applicability by the cardiologist in the catheterization-laboratory or under a simple fluoroscopy-unit, short stay of patients in the hospital without transfers to other departments, few personnel (1 scrubbed doctor, 1 non-scrubbed nurse), recognition of venous anomalies (singular left superior caval vein) without useless incisions for the patient. Complications such as pneumothorax, puncture of the subclavian artery, and dislocations of the electrodes have also been encountered. 相似文献
76.
Summary
Conclusion
Proteinase-activated receptor-2 (PAR-2)-mediated effects contribute to the intracellular signaling network in pancreatic tumor
cells. A role of PAR-2 as negative regulator in human pancreatic tumor growth might be implied.
Background Using the human pancreatic tumor cell line MIA PaCa-2, we evaluated cellular effects of trypsin and the PAR-2-activating peptide
SLIGRL on [Ca2+]i mobilization, Ins(1,4,5)P3 level, and protein kinase (PKC) activation. Furthermore, PAR-2 involvement in the regulation of cell proliferation has been
estimated by measurement of [3H]thymidine incorporation in MIA PaCa-2 cells.
Results Trypsin and the PAR-2 synthetic peptide agonist SLIGRL induced [Ca2+]i mobilization, transient increase in inositol (1,4,5) triphosphate level, and PKC translocation in MIA PaCa-2 cells. In addition,
SLIGRL induced a decrease in DNA synthesis in MIA PaCa-2 cells. 相似文献
77.
Heiko?AselmannEmail authorView authors OrcID profile Jan-Niclas?Kersebaum Alexander?Bernsmeier Jan?Henrik?Beckmann Thorben?M?ller Jan?Hendrik?Egberts Clemens?Schafmayer Christoph?R?cken Thomas?Becker 《International journal of colorectal disease》2018,33(11):1575-1581
Aim
Robotic surgery allows for a better visualization and more precise dissection especially in the narrow male pelvis and mid and lower third of the rectum. However, superiority to laparoscopic TME has yet to be proven. We therefore analyzed short-term outcomes of laparoscopic and robotic low anterior rectal resection for rectal cancer.Patients and methods
From 2011 to 2016, 44 robotic (RTME) and 41 laparoscopic (LTME) low anterior rectal resection with total mesorectal excision were performed at a single institution. Specimen quality was assessed and reported by an independent pathologist following international guidelines.Results
The groups did not differ significantly regarding gender, age, ASA stage, BMI, and distance of the lower tumor margin from the anal verge. More patients in the RTME group underwent preoperative chemoradiation (43.2 vs. 19.5%, p?=?0.019). The quality of the TME specimen was significantly better in the RTME group (complete/nearly complete/incomplete for RTME 97/0/3% and for LTME 78/17/5%, p?=?0.03). The conversion rate tended to be lower in the RTME group (7 vs. 17%, p?=?0.143). There was no difference in CRM positivity between the groups.Conclusion
Robotic surgery is safe and can improve the quality of TME for rectal cancer compared to laparoscopy. Any effect on long-term survival remains to be established.78.
We report the case of a 64-year-old woman who was admitted to our hospital for radiofrequency ablation of isthmus-dependent counterclockwise atrial flutter. Following an initially uncomplicated right atrial linear isthmus ablation that was associated with conversion of atrial flutter to sinus rhythm and evidence of complete isthmus block, the patient developed a small pericardial effusion, a marked and recurrent left-sided pleural effusion, and had significantly elevated inflammatory markers. After an extensive diagnostic work-up which excluded infectious, malignant and thromboembolic causes of the effusions, a diagnosis of postcardiac injury syndrome was made and the patient was treated with oral corticosteroids and nonsteroidal anti-inflammatory drugs. Over a treatment period of 2 months there was complete resolution of the pericardial and left-sided pleural effusions and normalization of inflammatory markers. Postcardiac injury syndrome is a rare complication of radiofrequency ablation that is characterized by signs of pericardial, pleural and pulmonary parenchymal inflammation. 相似文献
79.
High-frequency oscillatory ventilation (HFOV) has been shown to stimulate slowly adapting pulmonary stretch receptors (PSR) and thereby to inhibit spontaneous breathing, i.e. HFOV prolongs expiration or even elicits normocapnic apnea. However, during HFOV respiratory effects possibly mediated by pulmonary rapidly adapting receptors (RAR) have also been observed, e.g., diaphragmatic activation or augmented breaths. Therefore, we analyzed HFOV-induced changes in RAR activity in anaesthetized rabbits by mean of single fibre preparations of vagal RAR afferents. HFOV was applied in several combinations of airway pressure (Paw) and oscillation frequency (fOsc). In the sample of 60 RAR fibres prepared in 20 rabbits we found a wide spectrum of discharge patterns during HFOV. The inspiratory discharge rate during HFOV was increased in 38, decreased in 10, and unchanged in 12 RAR. The expiratory discharge rate was increased in 34, decreased in 17, and unchanged in 9 RAR. The effects of gradually changing Paw or of fOsc during HFOV were different in different fibres. In 17 fibres both inspiratory and expiratory discharge rates rose with increasing Paw during HFOV, whereas 19 fibres were not affected by increasing Paw. In some fibres either the inspiratory (12) or the expiratory (9) activity was inhibited in proportion to increasing Paw. From these results we conclude, that (a) the changes of RAR activity during HFOV are heterogeneous and the reflex effects of RAR stimulation may be balanced by RAR with decreased activity; (b) this heterogeneity of RAR discharge patterns explains the dominancy in the control of breathing during HFOV of the homogeneously stimulated PSR; and (c) depending on HFOV ventilatory parameters used the overall RAR stimulation may be strong enough to overrule the inspiration-inhibiting effects of PSR. 相似文献
80.
Dora Koller Carmen Belmonte Miriam Saiz‐Rodríguez Pablo Zubiaur Manuel Romn Dolores Ochoa Francisco Abad‐Santos 《Basic & clinical pharmacology & toxicology》2020,126(3):236-246
Aripiprazole treatment in schizophrenic patients was previously associated with lower or normalized prolactin levels. Genetic variants in cytochrome P450 (CYP) (CYP2D6), dopamine receptor (DRD2, DRD3) and serotonin receptor (HTR2A, HTR2C) genes were previously associated with antipsychotic‐induced hyperprolactinaemia. Our aim was to evaluate whether aripiprazole affects prolactin secretion and its relationship with pharmacogenetics. Thirty‐one healthy volunteers receiving a 10‐mg single oral dose of aripiprazole were genotyped for 12 polymorphisms in CYP2D6, DRD2, DRD3, HTR2A and HTR2C genes by qPCR. Aripiprazole and dehydro‐aripiprazole plasma concentrations were measured by HPLC‐MS/MS. Prolactin concentrations of the 31 volunteers taking aripiprazole and 12 volunteers receiving ibuprofen were determined by ELISA. Prolactin concentrations after ibuprofen intake were considered as control, since it is known to cause no effect. Prolactin concentrations were slightly higher in the aripiprazole group compared to the ibuprofen group. All prolactin pharmacokinetic parameters were higher in females than in males. CYP2D6 poor and intermediate metabolizers had notably higher prolactin Cmax and AUC0‐12 than normal and ultrarapid metabolizers. The DRD3 rs6280 polymorphism affected prolactin levels: volunteers carrying Ser/Ser genotype had significantly lower prolactin levels than volunteers carrying the Gly allele. Furthermore, HTR2C rs3813929 C/C homozygotes had significantly lower prolactin levels than T allele carriers. Nevertheless, aripiprazole did increase prolactin levels compared to ibuprofen. 相似文献