全文获取类型
收费全文 | 500篇 |
免费 | 32篇 |
国内免费 | 40篇 |
专业分类
耳鼻咽喉 | 44篇 |
儿科学 | 36篇 |
妇产科学 | 22篇 |
基础医学 | 27篇 |
口腔科学 | 14篇 |
临床医学 | 75篇 |
内科学 | 84篇 |
皮肤病学 | 5篇 |
神经病学 | 8篇 |
特种医学 | 93篇 |
外国民族医学 | 1篇 |
外科学 | 82篇 |
综合类 | 6篇 |
预防医学 | 8篇 |
眼科学 | 4篇 |
药学 | 49篇 |
肿瘤学 | 14篇 |
出版年
2022年 | 4篇 |
2021年 | 8篇 |
2020年 | 3篇 |
2019年 | 6篇 |
2018年 | 6篇 |
2017年 | 9篇 |
2016年 | 3篇 |
2015年 | 16篇 |
2014年 | 11篇 |
2013年 | 14篇 |
2012年 | 13篇 |
2011年 | 13篇 |
2010年 | 18篇 |
2009年 | 8篇 |
2008年 | 9篇 |
2007年 | 32篇 |
2006年 | 18篇 |
2005年 | 14篇 |
2004年 | 10篇 |
2003年 | 3篇 |
2002年 | 11篇 |
2001年 | 13篇 |
2000年 | 15篇 |
1999年 | 23篇 |
1998年 | 22篇 |
1997年 | 22篇 |
1996年 | 25篇 |
1995年 | 11篇 |
1994年 | 20篇 |
1993年 | 12篇 |
1992年 | 16篇 |
1991年 | 19篇 |
1990年 | 14篇 |
1989年 | 13篇 |
1988年 | 9篇 |
1987年 | 6篇 |
1986年 | 9篇 |
1985年 | 11篇 |
1984年 | 6篇 |
1983年 | 6篇 |
1982年 | 7篇 |
1981年 | 8篇 |
1980年 | 4篇 |
1978年 | 6篇 |
1977年 | 8篇 |
1976年 | 5篇 |
1975年 | 9篇 |
1974年 | 3篇 |
1973年 | 3篇 |
1972年 | 5篇 |
排序方式: 共有572条查询结果,搜索用时 15 毫秒
1.
In 44 patients with one or more calculi in the upper two-thirds of the ureter, single-stage percutaneous nephrolithotomy was performed through a middle or upper calyceal nephrostomy after cystoscopic placement of an occlusion balloon catheter distal to the calculus; in 42, the procedure was successful. The occlusion balloon catheter permitted retrograde opacification of all systems for enhanced renal puncture. In the last 30 patients an attempt was made either to push the calculus upward mechanically or to flush it upward into the renal pelvis with carbon dioxide or dilute contrast material. This was successful in 24 of these patients. Prior overnight occlusion of the ureter by means of ureteral dilatation further facilitates dislodgment of the calculus, which was successful in 12 of 13 patients. 相似文献
2.
Braffman BH; Coleman BG; Ramchandani P; Arger PH; Nodine CF; Dinsmore BJ; Louie A; Betsch SE 《Radiology》1994,190(3):797
3.
4.
Krushkal J; Xiong M; Ferrell R; Sing CF; Turner ST; Boerwinkle E 《Human molecular genetics》1998,7(9):1379-1383
Elevated blood pressure is an important risk factor for renal-, cerebro-
and cardiovascular diseases. We used an efficient discordant sib-pair
ascertainment scheme to investigate the impact of the distal end of the
long arm of human chromosome 5 (chromosomal region 5q31.1-qter) containing
genes for the alpha1B and beta2 adrenergic receptors and the dopamine
receptor type 1A on variation of systolic blood pressure in young
Caucasians. We measured eight highly polymorphic markers spanning this
positional candidate gene-rich region in 427 individuals from 55
three-generation pedigrees containing 69 discordant sibling pairs, and
calculated multipoint identity by descent (MIBD) probabilities. The results
of genetic linkage and association tests indicate that the region between
markers D5S2093 and D5S462 is significantly linked to one or more
polymorphic genes influencing interindividual variation in systolic blood
pressure levels. Since the alpha1B adrenergic receptor and dopamine
receptor type 1A genes are located close to these markers, these data
suggest that genetic variation in one or both of these G protein-coupled
receptors, which participate in the control of vascular tone, plays an
important role in influencing interindividual variation in systolic blood
pressure levels.
相似文献
5.
Acute porphyria is rare in orientals. We describe a Chinese woman with recurrent generalised tonic-clonic seizures and abdominal pain. Genomic DNA studies identified a heterozygous base substitution from guanine to adenine at nucleotide position 503, resulting in substitution of arginine by histidine at position 168 of the protein (R168H). This genetic abnormality is similar to the mutation reported in Caucasians with variegate porphyria. To the best of our knowledge, this is the first report in the English literature a Chinese patient with variegate porphyria with an identifiable mutation. A brief review of porphyria is presented. 相似文献
6.
M. Suckfüll C. Wimmer B. Jäger K. Schorn J. Thiery 《European archives of oto-rhino-laryngology》2000,257(2):59-61
The pathogenesis of sudden hearing loss (SHL) is still not well understood. Possible causes include increased blood viscosity,
microthrombosis or altered blood flow. Hypercholesterolemia, hyperfibrinogenemia and increased platelet aggregation are frequently
observed in patients with SHL. The aim of this study was to investigate whether drastic lowering of plasma cholesterol and
fibrinogen by selective extracorporal apheresis could have a beneficial effect on hearing recovery in these patients. Seven
patients with SHL were treated with an extracorporal procedure removing fibrinogen and cholesterol from plasma. Six of the
seven patients showed an immediate improvement in auditory thresholds following a single treatment of heparin-induced low-density
lipoprotein precipitation. These findings indicate for the first time that acute and drastic removal of plasma fibrinogen
and low-density lipoproteins may be an effective clinical method for the treatment of patients with SHL.
Received: 19 February 1999 / Accepted: 6 May 1999 相似文献
7.
Nagarathnam D Miao SW Lagu B Chiu G Fang J Murali Dhar TG Zhang J Tyagarajan S Marzabadi MR Zhang F Wong WC Sun W Tian D Wetzel JM Forray C Chang RS Broten TP Ransom RW Schorn TW Chen TB O'Malley S Kling P Schneck K Bendesky R Harrell CM 《Journal of medicinal chemistry》1999,42(23):4764-4777
Dihydropyrimidinones such as compound 12 exhibited high binding affinity and subtype selectivity for the cloned human alpha(1a) receptor. Systematic modifications of 12 led to identification of highly potent and subtype-selective compounds such as (+)-30 and (+)-103, with high binding affinity (K(i) = 0.2 nM) for alpha(1a) receptor and greater than 1500-fold selectivity over alpha(1b) and alpha(1d) adrenoceptors. The compounds were found to be functional antagonists in human, rat, and dog prostate tissues. Compound (+)-103 exhibited excellent selectively to inhibit intraurethral pressure (IUP) as compared to lowering diastolic blood pressure (DBP) in mongrel dogs (K(b)(DBP)/K(b)(IUP) = 40) suggesting uroselectivity for alpha(1a)-selective compounds. 相似文献
8.
Recent investigations have emphasized the role of activated granulocytes in mediating vascular endothelial injury in the pathogenesis of shock lung. In vitro studies have indicated that tight adherence of the neutrophil to the endothelium is crucial for the development of cellular injury. Fibronectin is critical to cell-to- substratum and cell-to-cell interactions. Since fibronectin resides in plasma, on endothelial cell surfaces and is secreted into cell matrices, the adhesive properties of fibronectin must be modulated, lest universal cell agglomeration occur, yet be enhanced when cell attachment is appropriate. In these studies, treatment of fibronectin- coated surfaces with neutrophil release products increased the adhesion of activated neutrophils. Similarly, endothelial cells treated with neutrophil release products become a more adherent substrate for neutrophils. This enhanced adherence generated by treatment of fibronectin with neutrophil supernatants is inhibitable by heat and the lysosomal proteinase inhibitor, pepstatin-A. Neutrophil release products cause proteolytic fragmentation of fibronectin and enhanced fibronectin immunofluorescence on endothelial cells. In addition, neutrophils are more injurious to endothelial cells that have been pretreated with neutrophil release products. Neutrophils may enhance their own adherence to endothelial cells by altering fibronectin, and this altered, or "inflamed," fibronectin may serve as an amplifier of inflammation. 相似文献
9.
van Kranen HJ; van Iersel PW; Rijnkels JM; Beems DB; Alink GM; van Kreijl CF 《Carcinogenesis》1998,19(9):1597-1601
The variation in colorectal cancer (CRC) incidence worldwide strongly
suggests a role for dietary influences. Based on epidemiological data,
protective effects of vegetables and fruit intake on CRC are widely
claimed, while other data indicate a possible increased CRC risk from
(higher) dietary fat intake. Therefore, we have investigated single and
interactive effects of dietary fat and a vegetable-fruit mixture (VFM) in
the ApcMin mouse, a mouse model for multiple intestinal neoplasia. In this
study, four different diets (A-D) were compared, which were either low in
fat (20% energy diets A/B) or high in fat (40% energy diets C/D). In
addition, 19.5% (wt/wt) of the carbohydrates in diets B and D were replaced
by a freeze-dried VFM. The diets were balanced so that they only differed
among each other in fat/carbohydrate content and the presence of specific
plant-constituents. Because the initiation of intestinal tumors in ApcMin
mice occurs relatively early in life, exposure to the diets was started in
utero. Without the addition of VFM, mice maintained at a high-fat diet did
not develop significantly higher numbers of small or large intestinal
adenomas than mice maintained at a low-fat diet. VFM added to a low-fat
diet significantly lowered multiplicity of small intestinal polyps (from
16.2 to 10.2/mouse, 15 animals/group), but not of colon tumors in male
ApcMin mice only. Strikingly, addition of VFM to female mice maintained on
a low-fat diet and to both sexes maintained on a high-fat diet
significantly enhanced intestinal polyp multiplicity (from 16.5 to 26.7
polyps/mouse). In conclusion, our results indicate that neither a lower fat
intake nor consumption of VFM included in a high-fat diet decreases the
development of polyps in mice genetically predisposed to intestinal tumor
development.
相似文献
10.