全文获取类型
收费全文 | 28304篇 |
免费 | 1912篇 |
国内免费 | 123篇 |
专业分类
耳鼻咽喉 | 367篇 |
儿科学 | 633篇 |
妇产科学 | 542篇 |
基础医学 | 4143篇 |
口腔科学 | 415篇 |
临床医学 | 2583篇 |
内科学 | 6509篇 |
皮肤病学 | 557篇 |
神经病学 | 2981篇 |
特种医学 | 1046篇 |
外国民族医学 | 3篇 |
外科学 | 4679篇 |
综合类 | 155篇 |
一般理论 | 7篇 |
预防医学 | 1476篇 |
眼科学 | 465篇 |
药学 | 2164篇 |
中国医学 | 97篇 |
肿瘤学 | 1517篇 |
出版年
2023年 | 103篇 |
2022年 | 204篇 |
2021年 | 455篇 |
2020年 | 274篇 |
2019年 | 500篇 |
2018年 | 602篇 |
2017年 | 461篇 |
2016年 | 509篇 |
2015年 | 647篇 |
2014年 | 870篇 |
2013年 | 1153篇 |
2012年 | 1753篇 |
2011年 | 1830篇 |
2010年 | 1169篇 |
2009年 | 1038篇 |
2008年 | 1747篇 |
2007年 | 1801篇 |
2006年 | 1689篇 |
2005年 | 1759篇 |
2004年 | 1684篇 |
2003年 | 1683篇 |
2002年 | 1596篇 |
2001年 | 496篇 |
2000年 | 421篇 |
1999年 | 483篇 |
1998年 | 412篇 |
1997年 | 351篇 |
1996年 | 284篇 |
1995年 | 309篇 |
1994年 | 241篇 |
1993年 | 247篇 |
1992年 | 303篇 |
1991年 | 264篇 |
1990年 | 227篇 |
1989年 | 243篇 |
1988年 | 207篇 |
1987年 | 235篇 |
1986年 | 221篇 |
1985年 | 168篇 |
1984年 | 181篇 |
1983年 | 170篇 |
1982年 | 144篇 |
1981年 | 118篇 |
1980年 | 107篇 |
1979年 | 125篇 |
1978年 | 72篇 |
1977年 | 91篇 |
1975年 | 70篇 |
1973年 | 85篇 |
1972年 | 61篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
B. J. Morris F. Pinet J.-B. Michel F. Soubrier P. Corvol 《Clinical and experimental pharmacology & physiology》1987,14(3):227-231
1. A pulmonary chemodectoma/glomangiosarcoma that had metastasized from the thigh was studied after removal from a 22 year old Algerian patient with hypertension, high plasma prorenin and signs of secondary aldosteronism. 2. Renin and renin mRNA were localized in sections of the tumour tissue using monoclonal anti-human renin antibody and human renin cDNA probe, respectively. 3. The cells grew prolifically in culture, but, even though their renin content was similar to that of transfected human juxtaglomerular cell tumour cells (approximately 1 pg/microgram DNA), their rate of secretion of renin was much lower (0.05-0.15 cf. 0.5-1.5 pg/h per microgram DNA). 4. Forskolin (10 mumol/l for 24 h) increased secretion of renin from 1.9 +/- 0.36 to 4.1 +/- 0.64 pg/ml per h of culture (P less than 0.001, n = 11), consistent with cAMP being a second messenger in the secretory mechanism. 5. The cells should provide valuable information about intracellular mechanisms for the regulation of renin synthesis and secretion. 相似文献
53.
Michel Broyer Geneviève Guest Marie-France Gagnadoux Daniel Beurton 《Pediatric nephrology (Berlin, Germany)》1987,1(1):16-21
The files of 334 consecutive cadaver kidney (CK) and of 27 living related (LR) transplantations (T) in children and adolescents performed from 1973 to 1984 have been reviewed. Following cadaver transplantation, 52 patients (15%) never had hypertension (HT), 41 patients (12%) had only initial HT up to 6 months after transplantation and 18 other patients (5%) exhibited transient HT episodes while on high-dose steroid therapy. Finally, 209 patients (62%) had HT for periods longer than 6 months and 16 patients (5%) until death or graft failure within the first 3 months. Chronic graft rejection was the major cause of HT, but other factors either isolated or in association were also present. Renal artery stenosis (RAS) was diagnosed in 43 cases (13%) 2–17 months post-transplantation; 10 of these were operated upon (5 successfully) and 9 underwent transluminal angioplasty with a single success. Nine cases of RAS resolved spontaneously. HT was attributed to the host kidney in 10 cases (3%) and to recurrence of primary renal disease in 9 (3%). HT observed after CKT was sometimes severe and difficult to control. Acute complications from HT were recorded in 35 cases, with 6 deaths and 2 severe neurological sequelae. Among 25 LRT, 11 cases (40%) had no HT 13 (48%) had HT for longer than 6 months. In this group, no case of RAS was observed and only one complication (without sequelae) was noted. In conclusion, HT is a frequent and sometimes severe complication post-transplantation in children and adolescents. 相似文献
54.
55.
I Mercanti F Michel L Thomachot D-A Loundou C Nicaise R Vialet J-N Di Marco P Lagier C Martin 《Archives de pédiatrie》2007,14(7):875-880
Transcutaneous bilirubinometry is an effective screening tool for neonatal jaundice in full-term babies. But its accuracy is not shown yet in preterm infants. METHODOLOGY: We carried out a prospective study in a neonatal intensive care unit. The study included 47 preterm infants. From birth, a transcutaneous bilirubin measurement (BTc) using the BiliCheck was made on the forehead of each newborn every 8 h. Blood sampling for determination of total serum bilirubin (BS) was combined with BTc: 1) if value of BTc was higher than limits values for phototherapy; 2) on the second day of life and 3) 4 hours after cessation of phototherapy. RESULTS: Mean gestational age was 30 week and mean birth weight was 1419 g. We studied 151 pairs of BTc and BS. Mean values obtained by BTc and BS were respectively 160.6+/-50 mumol/L and 190.6+/-61.4 mumol/L. A significant correlation between BTc and BS was found. But the limits of agreement were very wide. The negative predictive value (NPV) of BTc was above 90% in each group of gestational age. DISCUSSION: The need for phototherapy cannot be determined by BTc in preterm infants. But the BTc is reliable when its value is under the limits for phototherapy. CONCLUSION: With a very high incidence of neonatal jaundice (87%) in our cohort, a value of BTc under the limits for phototherapy has a good NPV in preterm infants. 相似文献
56.
57.
Nine patients have undergone single-stage radical cystectomy and ileal conduit urinary diversion two to fifty-one months after coronary artery bypass procedures. Two patients presenting with intractable angina at the time their malignant disease was being evaluated required bypass surgery before cystectomy could be undertaken. No significant cardiac morbidity occurred postoperatively, and all remain alive without evidence of malignant disease. 相似文献
58.
59.
Véronique Strijckmans Michel Bottlaender Humin Luo Michèle Ottavianil Daniel W. McPherson Christian Loc'h Chantal Fuseau Furn F. Knapp Bernard Mazière 《European journal of nuclear medicine and molecular imaging》1997,24(5):475-482
We studied the potential of three radiobrominated isomers of BrQNP, (Z(-,-)-[76Br]BrQNP,E(-,-)-[76Br]BrQNP andE(-,+)-[76Br]BrQNP), as suitable radioligands for imaging of central muscarinic cholinergic receptors in the human brain. These radioligands were stereospecifically prepared by electrophilic radiobromodestannylation of the respective tributylstannyl precursors using no-carrier-added [76Br]BrNH4 and peracetic acid. Preliminary pharmacological characterizations were determined by biodistribution, autoradiography, competition, displacement and metabolite studies in rats. The (-,-)-configuration presented important specific uptakes in brain muscarinic cholinergic receptor (mAChR)-rich structures and in heart, low metabolization rates and an apparent M2 selectivity. The (-,+)-configuration revealed more rapid clearance, lower uptake, a higher metabolization rate and an apparent M1 selectivity. Reversibility of the binding was confirmed for the three radiotracers. Positron emission tomography in the living baboon brain revealed high and rapid uptake in the brain and accumulation in the mAChR-rich structures studied. At 30 min p.i., theE(-,-)-radiotracer reached a plateau in cortex, pons and thalamus with concentrations of 29%, 24% and 19% ID/l, respectively.Z(-,-)-[76Br]BrQNP also accumulated in these structures, reaching a maximal uptake (27% ID/l) in the cortex 2 h p.i. At 5 min p.i. a plateau (17% ID/l) was only observed in the cortex for theE(-,+)-[76Br]BrQNP; by contrast, the other structures showed slow washout. After 3 weeks, the (-,-)-radiotracers were studied in the same baboon pretreated with dexetimide (1 mg/kg), a well-known muscarinic antagonist. In all the mAChR structures, the highly reduced uptake observed after this preloading step indicates that these radiotracers specifically bind to muscarinic receptors.Z(-,-)-[76Br]BrQNP, which is displaced in higher amounts from M2 mAChR-enriched structures, reveals an M2 affinity. The two isomers having the (-,-)-configuration are potential probes for investigating central muscarinic receptors. The absolute configuration on the acetate chiral centre influences their muscarinic subtype selectivity and thecis-trans isomerism of the vinyl moiety affects their specific fixation. 相似文献
60.
Previous work from our laboratory showed that spontaneous contractile activity of jejunal smooth muscle increases after small
bowel transplantation. Our aim was to determine whether small bowel transplantation alters the function of nonadrenergic,
noncholinergic (NANC) nerves. Seven groups of rats, (n ≥7 in each group) were studied as follows: 1 week after sham celiotomy
and 1 week and 8 weeks after 45 minutes of ischemia/ reperfusion (IR1 and IR8), jejunal and ileal transection and reanastomosis
(TR1 and TR8), or orthotopic small bowel transplantation (TX1 and TX8). Contractility of jejunal circular muscle strips was
studied in vitro. Spontaneous contractile activity increased in the IR1, TR1, and TX1 and TX1 and TX8 groups (P<0.01). Under NANC conditions, spontaneous activity increased in TR1 and in both TX1 and TX8 (P<0.01) despite the lack of an increase in the frequency of contraction in TX1. Electrical field stimulation inhibited contractile
activity at low frequencies, but under NANC conditions this inhibition persisted at higher frequencies. The calculated equieffective
frequency (F100) that produced a response equal to baseline contractile activity was similar in all groups, but under NANC conditions was
greater in TX1 (P<0.025). Functional alterations of NANC nerves are partly responsible for the increase in spontaneous activity in rat jejunal
circular muscle strips after a limited ischemia/reperfusion injury, after selective disruption of enteric neural continuity
(transection/reanastomosis), and after small bowel transplantation. These findings may provide important insight into graft
dysfunction after small bowel transplantation in humans.
Supported by United States Public Health Service grant DK 39337 from the National Institutes of Health and by the Mayo Foundation. 相似文献