全文获取类型
收费全文 | 95526篇 |
免费 | 4864篇 |
国内免费 | 337篇 |
专业分类
耳鼻咽喉 | 1169篇 |
儿科学 | 2725篇 |
妇产科学 | 2249篇 |
基础医学 | 13130篇 |
口腔科学 | 1798篇 |
临床医学 | 7676篇 |
内科学 | 23431篇 |
皮肤病学 | 2058篇 |
神经病学 | 8648篇 |
特种医学 | 3106篇 |
外国民族医学 | 32篇 |
外科学 | 11942篇 |
综合类 | 428篇 |
一般理论 | 24篇 |
预防医学 | 8422篇 |
眼科学 | 1599篇 |
药学 | 6351篇 |
中国医学 | 255篇 |
肿瘤学 | 5684篇 |
出版年
2023年 | 527篇 |
2022年 | 991篇 |
2021年 | 2342篇 |
2020年 | 1220篇 |
2019年 | 2081篇 |
2018年 | 4236篇 |
2017年 | 2671篇 |
2016年 | 2023篇 |
2015年 | 2170篇 |
2014年 | 2858篇 |
2013年 | 4069篇 |
2012年 | 6247篇 |
2011年 | 6323篇 |
2010年 | 3410篇 |
2009年 | 2961篇 |
2008年 | 5395篇 |
2007年 | 5538篇 |
2006年 | 5237篇 |
2005年 | 5293篇 |
2004年 | 4991篇 |
2003年 | 4666篇 |
2002年 | 4429篇 |
2001年 | 2358篇 |
2000年 | 2478篇 |
1999年 | 2037篇 |
1998年 | 689篇 |
1997年 | 474篇 |
1996年 | 459篇 |
1995年 | 402篇 |
1994年 | 345篇 |
1993年 | 316篇 |
1992年 | 1074篇 |
1991年 | 918篇 |
1990年 | 912篇 |
1989年 | 824篇 |
1988年 | 729篇 |
1987年 | 750篇 |
1986年 | 656篇 |
1985年 | 597篇 |
1984年 | 437篇 |
1983年 | 354篇 |
1982年 | 218篇 |
1979年 | 308篇 |
1978年 | 227篇 |
1974年 | 241篇 |
1973年 | 244篇 |
1972年 | 239篇 |
1971年 | 232篇 |
1969年 | 208篇 |
1968年 | 209篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
J M Ragnaud H Gin P Tauzin-Fin P Ballanger R Ballanger J Aubertin 《Pathologie-biologie》1983,31(5):434-437
The main point of this study resides in comparing the efficiency and the disadvantages of using cefazoline and cotrimoxazole in the prevention of post-surgery infections of the low urinary tract. 91 patients who were about to undergo urologic surgery were divided in three groups for randomisation. 31 patients received 500 mg of intramuscular cefazoline every eight hours, the day before surgery, the day of surgery and five days following surgery. 30 others received 800 mg of intramuscular sulfametoxazole and 160 mg of trimetoprime every 12 hours during the same lapse of time. The third group of 30 patients did not receive any antibiotics. Age, sex, clinical pathology needing surgery and indwelling catheter were the same in the three groups. The group treated by cefazoline, presented 5 post surgery infections among which 3 transitory fevers and 2 isolated bacteriurias. In the group treated by cotrimoxazole, there were 7 post surgery infections among which 3 fevers and 4 isolated bacteriurias. Tolerance in both cases was similar. In the control group, there were 19 post-surgery infections with 2 cases of sepsis, 14 transitory fevers and 3 isolated bacteriurias. These results show the importance of antibiotic prophylaxy in urologic surgery of the low genital tract whether the patient has a urethral catheter or not and whatever the type of urologic surgery. But, there is no significant difference between cefazoline and cotrimoxazole. 相似文献
63.
E Maquarre C Artus Z Gadhoum C Jasmin F Smadja-Joffe J Robert-Lézénès 《Leukemia》2005,19(12):2296-2303
We have recently reported that ligation of the CD44 cell surface antigen with A3D8 monoclonal antibody (mAb) triggers incomplete differentiation and apoptosis of the acute promyelocytic leukemia (APL)-derived NB4 cells. The present study characterizes the mechanisms underlying the apoptotic effect of A3D8 in NB4 cells. We show that A3D8 induces activation of both initiator caspase-8 and -9 and effector caspase-3 and -7 but only inhibition of caspase-3/7 and caspase-8 reduces A3D8-induced apoptosis. Moreover, A3D8 induces mitochondrial alterations (decrease in mitochondrial membrane potential DeltaPsi m and cytochrome c release), which are reduced by caspase-8 inhibitor, suggesting that caspase-8 is primarily involved in A3D8-induced apoptosis of NB4 cells. However, the apoptotic process is independent of TNF-family death receptor signalling. Interestingly, the general serine protease inhibitor 4-(2-aminoethyl)-benzenesulfonyl fluoride (AEBSF) decreases A3D8-induced apoptosis and when combined with general caspase inhibitor displays an additive effect resulting in complete prevention of apoptosis. These results suggest that both caspase-dependent and serine protease-dependent pathways contribute to A3D8-induced apoptosis. Finally, A3D8 induces apoptosis in all-trans-retinoic acid-resistant NB4-derived cells and in APL primary blasts, characterizing the A3D8 anti-CD44 mAb as a novel class of apoptosis-inducing agent in APL. 相似文献
64.
65.
Arminda Jorge Félix Lorente Luís Taborda-Barata 《Pediatric allergy and immunology》2006,17(6):466-473
The prevalence of latex allergy has been increasing not only in risk groups but also in the general population, where it is accepted to average 1%. In children, latex sensitization prevalence studies are scarce and involve different population sampling and allergy testing methods, which makes it difficult to compare across studies. Nevertheless, existing studies point towards a low prevalence of latex allergy in children, which still needs to be confirmed in the Portuguese population. Aiming at studying the prevalence of latex sensitization and allergy in a sample of Portuguese children, we studied 182 children from two different hospital outpatient clinics. A standardized questionnaire focusing on atopic background, previous history and allergic signs or symptoms on exposure to latex or fruits was given to all children and parents. Skin prick testing was performed with a battery of common aeroallergens as well as latex. Serum total IgE, Phadiatop, F x 5E and latex-specific IgE were determined in all children. Specific IgE to latex-crossreacting fruits was determined in latex-sensitized children. Based upon the questionnaire, the prevalence of latex allergy would be 0.5%. The prevalence of latex sensitization would be 3.8%, when based solely upon skin prick testing, and 12.1% (>/=0.35 IU/ml) or 6.6% (>/=0.70 IU/ml) when based singly upon determination of latex-specific IgE. When positive results for either test were considered, the prevalence of latex sensitization was 14.3%. All latex-sensitized children were atopic. Sensitivity to latex-crossreacting foodstuffs was demonstrated in 61.5% of latex-sensitized children (16/26). This study shows that the prevalence of latex allergy and sensitization in Portuguese atopic and non-atopic children, as analysed using various diagnostic methods, is similar to that observed in other countries. In addition, the assessment of latex allergy and sensitization should always include skin prick testing and determination of serum IgE. 相似文献
66.
r. s. choung n. j. talley j. peterson m. camilleri d. burton w. s. harmsen † & a. r. zinsmeister † 《Neurogastroenterology and motility》2007,19(3):180-187
Itopride, a dopamine D2 antagonist and acetylcholinesterase inhibitor, significantly improved symptoms in patients with functional dyspepsia in one phase II randomized trial. However, the mechanisms by which itopride may improve symptoms are unknown. We aimed to compare the effects of two doses of itopride and placebo on gastric volumes, gastric emptying, small bowel transit and satiation in female and male healthy volunteers. Randomized, double-blind, placebo-controlled study evaluated gastric function before and after 7 days of itopride 100 mg (n = 16) or 200 mg (n = 15) or placebo (n = 15) t.i.d. Validated methods were used to study gastric accommodation (single photon emission computed tomography), gastric emptying and orocecal transit and satiation postnutrient challenge. The three arms were comparable with regard to age, gender and body mass index. There were no statistically significant effects of itopride on gastric emptying, orocecal transit, fasting gastric volume, maximum tolerated volume or aggregate symptom score with nutrient drink challenge. Postprandial (PP) change in gastric volume differed in the three groups (P = 0.019): 625[+/-28 (SEM)], 555(+/-26) and 512(+/-33) in placebo, itopride 100 and 200 mg groups, respectively. In healthy subjects, itopride reduced total PP gastric volume without accelerating gastric emptying or significantly altering gastric motor and sensory function in healthy individuals. 相似文献
67.
Antonio S. Salinas Sánchez Jesús Cifuentes Tebar Miguel Segura Martín José M. Giménez Bachs María J. Donate Moreno Héctor Pastor Navarro Julio A. Virseda Rodríguez 《American journal of transplantation》2005,5(8):2074-2077
Ureteral herniation is a rare entity. We report the first case of extraperitoneal ureteral herniation in a pediatric en bloc renal graft causing obstructive uropathy. A 70-year-old, obese patient with an en bloc renal transplant was found to have ureterohydronephrosis in the right renal graft on magnetic resonance imaging. Nephrostomy with insertion of a double-J catheter confirmed the presence of a ureteral loop within the inguinal tract. Surgery confirmed herniation of the ureter through the internal inguinal ring, crossing over the spermatic cord. We performed release, resection, ureteral reimplantation and hernioplasty. Four months later, renal function was normal and urinary tract dilation had diminished. This case illustrates an unusual cause of obstructive uropathy in a transplanted kidney. Apart from obesity, two other factors may have contributed to its development: presence of a redundant ureter, and the fact that the ureter had been placed over, rather than under, the spermatic cord. 相似文献
68.
Pilar Nicolás 《Hereditary cancer in clinical practice》2007,5(3):144-152
The specific characteristics of genetic data lead to ethical-legal conflicts in the framework of genetic diagnosis. Several international organisations, including UNESCO and the Council of Europe, have enacted rules referring to the use of genetic information. This paper discusses possible legal and ethical criteria that could be used in genetic testing. 相似文献
69.
70.
Sylvain Miraux Jean-Michel Franconi Eric Thiaudière 《Magnetic resonance in medicine》2006,56(3):469-473
Blood velocity is a functional parameter that is not easily assessed noninvasively, especially in small animals. A new noninvasive method that uses magnetic resonance angiography (MRA) to measure blood flows is proposed. This method is based on the time-of-flight (TOF) phenomenon. By initially suppressing the signal from the stationary spins in the area of interest, it is possible to sequentially visualize only the signal from the moving spins entering a given volume. With this method, 3D cine images of the blood flow can be generated by positive contrast, with unparalleled spatial (<200 microm) and temporal resolutions (<10 ms/image). As a result, it is possible to measure flow in sinuous paths. The present method was applied in vivo to measure the blood velocity in mouse carotid arteries. Because of its robustness and simplicity of implementation, this method has numerous potential applications for fundamental studies in small animal models. 相似文献