全文获取类型
收费全文 | 5411篇 |
免费 | 525篇 |
国内免费 | 20篇 |
专业分类
耳鼻咽喉 | 166篇 |
儿科学 | 149篇 |
妇产科学 | 149篇 |
基础医学 | 642篇 |
口腔科学 | 203篇 |
临床医学 | 582篇 |
内科学 | 931篇 |
皮肤病学 | 68篇 |
神经病学 | 445篇 |
特种医学 | 296篇 |
外科学 | 691篇 |
综合类 | 166篇 |
一般理论 | 5篇 |
预防医学 | 468篇 |
眼科学 | 178篇 |
药学 | 429篇 |
中国医学 | 3篇 |
肿瘤学 | 385篇 |
出版年
2021年 | 67篇 |
2019年 | 65篇 |
2018年 | 86篇 |
2017年 | 70篇 |
2016年 | 83篇 |
2015年 | 101篇 |
2014年 | 99篇 |
2013年 | 164篇 |
2012年 | 223篇 |
2011年 | 232篇 |
2010年 | 140篇 |
2009年 | 124篇 |
2008年 | 197篇 |
2007年 | 231篇 |
2006年 | 209篇 |
2005年 | 218篇 |
2004年 | 205篇 |
2003年 | 185篇 |
2002年 | 161篇 |
2001年 | 190篇 |
2000年 | 169篇 |
1999年 | 155篇 |
1998年 | 86篇 |
1997年 | 103篇 |
1996年 | 92篇 |
1995年 | 69篇 |
1994年 | 52篇 |
1993年 | 63篇 |
1992年 | 132篇 |
1991年 | 119篇 |
1990年 | 138篇 |
1989年 | 129篇 |
1988年 | 127篇 |
1987年 | 111篇 |
1986年 | 122篇 |
1985年 | 117篇 |
1984年 | 81篇 |
1983年 | 88篇 |
1982年 | 54篇 |
1981年 | 65篇 |
1979年 | 79篇 |
1978年 | 63篇 |
1977年 | 46篇 |
1976年 | 56篇 |
1975年 | 40篇 |
1974年 | 49篇 |
1973年 | 41篇 |
1972年 | 47篇 |
1971年 | 43篇 |
1970年 | 41篇 |
排序方式: 共有5956条查询结果,搜索用时 15 毫秒
91.
Recurrent cardiac myxoma: the surgical implications of two distinct groups of patients 总被引:1,自引:0,他引:1
D A Waller D F Ettles N R Saunders G Williams 《The Thoracic and cardiovascular surgeon》1989,37(4):226-230
15 consecutive cases where patients (11 female, 4 male) had undergone surgical excision of cardiac myxoma were reviewed. The 11 survivors were re-assessed by trans-oesophageal echocardiography and recurrent myxoma was detected in 2 patients. These two were the only patients who had originally presented with multiple myxomas. Analysis of these cases in conjunction with 26 previously reported cases of recurrence identifies two distinct groups of patients. In one group (12 cases, mean age 48.7 years) recurrence occurred at the site of previous excision, typically following the removal of a single septal myxoma by partial thickness excision. In the second group, which includes our two cases, (16 cases, mean age 30.6 years) recurrent myxoma was found distant to the site of previous excision, typically in younger patients who had multiple myxomas at original operation. These results suggest that 1) single myxomas should be removed by full thickness excision 2) in younger patients with multiple myxomas surgery should be as radical as possible. 相似文献
92.
Blumer JB Lord K Saunders TL Pacchioni A Black C Lazartigues E Varner KJ Gettys TW Lanier SM 《Endocrinology》2008,149(8):3842-3849
Activator of G protein signaling (AGS)-3 plays functional roles in cell division, synaptic plasticity, addictive behavior, and neuronal development. As part of a broad effort to define the extent of functional diversity of AGS3-regulated-events in vivo, we generated AGS3 null mice. Surprisingly, AGS3 null adult mice exhibited unexpected alterations in cardiovascular and metabolic functions without any obvious changes in motor skills, basic behavioral traits, and brain morphology. AGS3 null mice exhibited a lean phenotype, reduced fat mass, and increased nocturnal energy expenditure. AGS3 null mice also exhibited altered blood pressure control mechanisms. These studies expand the functional repertoire for AGS3 and other G protein regulatory proteins providing unexpected mechanisms by which G protein systems may be targeted to influence obesity and cardiovascular function. 相似文献
93.
We tested whether human duodenojejunal mucosa is able to synthesize apoproteins from amino acid precursors because lipoprotein-like particles are visualized by electron microscopy in human absorptive cells and because apoproteins are synthesized by the perfused rat intestine. Duodenojejunal biopsies from 21 normal fasting volunteers were incubated with L-[U-14C]leucine; 15.6 +/- 3.3 nmoles of the [14C]leucine was incorporated into protein by 100 mg wet weight of biopsies during an incubation of 2 hr. No [14C]leucine was incorporated by boiled biopsies. Homogenates of incubated biopsies were fractionated by ultracentrifugation: 43 +/- 2% of the incorporated 14C as found in the d less than 1.006 fraction; 3.2 +/- 0.6%, 8.1 +/- 1.0% and 48 +/- 2% were found to be associated with the d = 1.006 to 1.063, d = 1.063 to 1.25, and d greater than 1.25 fractions, respectively. The specific activity in the d less than 1.006 fraction was 5.6 times greater than that in the other fractions. Of the 14C incorporated into the d less than 1.006 fraction, 10.8, 7.2, and 7.1% were specifically precipitated by rabbit antihuman apoproteins A-I, A-II, and B, respectively. Of the 14C incorporated into the d = 1.006 to 1.063 fraction, 11.3 4.1, and 8.5% were specifically precipitated by rabbit antihuman apoprotein A-I, A-II, and B, respectively. Approximately 5% of the 14C incorporated by the d = 1.063 to 1.25 fractions were precipitated by rabbit antihuman apoprotein A-I or A-II. None of the d less than 1.25 fractions precipitated a significant amount of radioactivity with rabit antihuman apoprotein C-II, or antiarginine-rich apoprotein. None of the antibodies precipitated radioactivity from the d greater than 1.25 fraction. These experiments suggest that human duodenojejunal mucosa is able to synthesize in vitro apoproteins A-I, A-II, and B from amino acid precursors. The specificity of the immunoprecipitates was confirmed by sodium dodecyl sulfate polyacrylamide gel electrophoresis. 相似文献
94.
Dr. Michèle Gue BS Jean Fioramonti DS Jacques Frexinos MD M. Alvinerie BS Lionel Bueno DS 《Digestive diseases and sciences》1987,32(12):1411-1417
The effects of acoustic stress (AS) on gastrointestinal motility and their prevention by previous treatment with naloxone, phentolamine, propranolol, muscimol, and diazepam were investigated in intact and vagotomized fasted dogs fitted with chronically implanted strain gauges on the antrum at 10 cm from pylorus and on the jejunum at 70 and 140 cm from the pylorus. These effects were compared to those produced by intracerebroventricular administration of ovine corticotropin releasing factor (oCRF). Beginning 40–50 min after the occurrence of a gastric migrating motor complex (MMC), a 1-hr hearing of prerecorded intense music through earpieces (<100 dB) delayed the occurrence of the next gastric MMC observed after 2.8±1.2 hr, while jejunal MMC were still present at a normal frequency. During AS, heart rate and plasma cortisol were significantly increased by 32.7 and 215%, respectively, 10–15 min after the beginning of hearing. The AS-induced lengthening of the gastric MMC cycle as well as cortisol increase were abolished after previous administration of diazepam (0.5 mg/kg intramuscular) or muscimol (10 g/kg intravenous), while they were still present after naloxone (0.1 mg/kg intravenous), phentolamine (0.2 mg/kg intravenous), or propranolol (0.1 mg/kg intravenous). CRF administered intracerebroventricularly (100 ng/kg) also delayed the occurrence of gastric MMC without affecting jejunal motility, and this effect was not antagonized by previous treatment with diazepam or muscimol. Both the effects of AS and CRF were abolished after bilateral thoracic vagotomy. These results suggest that the selective inhibition of gastric motility induced by noise in dog is due to the CNS release of CRF which affects, in turn, the vagal output to the stomach. The suppressive action of diazepam or GABA agonist on noise-induced gastric hypomotility may be related to blockade of the AS-induced CRF release. 相似文献
95.
Spinal cord injury and protection 总被引:5,自引:0,他引:5
D K Anderson P Demediuk R D Saunders L L Dugan E D Means L A Horrocks 《Annals of emergency medicine》1985,14(8):816-821
Subsequent to traumatic injury of the spinal cord, a series of pathophysiological events occurs in the injured tissue that leads to tissue destruction and paraplegia. These include hemorrhagic necrosis, ischemia, edema, inflammation, neuronophagia, loss of Ca2+ from the extracellular space, and loss of K+ from the intracellular space. In addition, there is trauma-initiated lipid peroxidation and hydrolysis in cellular membranes. Both lipid peroxidation and hydrolysis can damage cells directly; hydrolysis also results in the formation of the biologically active prostaglandins and leukotrienes (eicosanoids). The time course of membrane lipid alterations seen in studies of antioxidant interventions suggests that posttraumatic ischemia, edema, inflammation, and ionic fluxes are the result of extensive membrane peroxidative reactions and lipolysis that produce vasoactive and chemotactic eicosanoids. A diverse group of compounds has been shown to be effective in ameliorating spinal cord injury in experimental animals. These include the synthetic glucocorticoid methylprednisolone sodium succinate (MPSS); the antioxidants vitamin E, selenium, and dimethyl sulfoxide (DMSO); the opiate antagonist naloxone; and thyrotropin-releasing hormone (TRH). With the exception of TRH, all of these agents have demonstrable antioxidant and/or anti-lipid-hydrolysis properties. Thus the effectiveness of these substances may lie in their ability to quench membrane peroxidative reactions or to inhibit the release of fatty acids from membrane phospholipids, or both. Whatever the mode of action, early administration appears to be a requirement for maximum effectiveness. 相似文献
96.
Sean P. Saunders Christabelle S.M. Goh Sara J. Brown Colin N.A. Palmer Rebecca M. Porter Christian Cole Linda E. Campbell Marek Gierlinski Geoffrey J. Barton Georg Schneider Allan Balmain Alan R. Prescott Stephan Weidinger Hansjörg Baurecht Michael Kabesch Christian Gieger Young-Ae Lee Roger Tavendale Somnath Mukhopadhyay Stephen W. Turner Vishnu B. Madhok Frank M. Sullivan Caroline Relton John Burn Simon Meggitt Catherine H. Smith Michael A. Allen Jonathan N.W. N. Barker Nick J. Reynolds Heather J. Cordell Alan D. Irvine W.H. Irwin McLean Aileen Sandilands Padraic G. Fallon 《The Journal of allergy and clinical immunology》2013
97.
Rachel Saunders Deborah Jacobvitz Maria Zaccagnino Lauren M. Beverung Nancy Hazen 《Attachment & human development》2013,15(4):403-420
This study explored the kinds of relationship experiences associated with earned-security, i.e., the extent to which mothers who report early negative relationship histories with their parents are later able to form a secure working model of attachment (indicated by the ability to speak clearly and coherently about these histories). Mothers from a low-risk sample (N = 121) expecting their first child completed the Adult Attachment Interview (AAI), which was used to assess earned-security retrospectively using the stringent definition recommended by Main and Hesse (Hesse, 2008; Main, Goldwyn, & Hesse, 2002), as well as to identify alternative support figures. Participants also completed self-report measures of depressive symptomatology, questionnaires concerning their experiences in therapy, and later, when their babies were 12 to 15 months old, the Strange Situation procedure. Sixteen mothers were classified as earned-secure (25% of those classified as secure-autonomous and 13% of the whole sample). Women who were earned-secure (vs. insecure and continuous-secure) reported significantly higher levels of emotional support, but not instrumental support, from alternative support figures. They also spent more time in therapy than did insecure and continuous-secure women and were more likely to form secure attachments with their infants than insecure women. These findings were obtained even after controlling for depressive symptoms. 相似文献
98.
M Rudolf J F Riordan B J Grant D J Maberly K B Saunders 《British journal of diseases of the chest》1978,72(4):307-312
Fourteen patients with acute severe asthma necessitating hospital admission were all treated with a standard therapeutic regimen, and in addition received either bromhexine or placebo (initially intravenously and subsequently orally) double-blind. We were unable to show any significant improvement in the rate of recovery of the bromhexine-treated group, in terms of either arterial blood gases or change in peak expiratory flow rates. 相似文献
99.
The correlations between the deoxyuridine-suppressed value and some conventional haematological parameters (Hb concentration, red cell count, MCV, total white cell count, red cell folate level and serum vitamin B12 level) have been investigated in 40 patients with megaloblastic haemopoiesis due to folate or vitamin B12. deficiency. The only statistically significant correlations found were (a) an inverse correlation between the deoxyuridine-suppressed value and the Hb level or red cell count in both the folate- and vitamin B12-deficient groups and (b) a direct correlation between the deoxyuridine-suppressed value and MCV in the vitamin B12-deficient group. The results indicated that the deoxyuridine-suppressed value was a better index of the magnitude of the disturbance in red cell production induced by folate or vitamin B12 deficiency than either the red cell folate or serum vitamin B12 levels. 相似文献
100.