全文获取类型
收费全文 | 17177篇 |
免费 | 967篇 |
国内免费 | 139篇 |
专业分类
耳鼻咽喉 | 144篇 |
儿科学 | 398篇 |
妇产科学 | 355篇 |
基础医学 | 1857篇 |
口腔科学 | 461篇 |
临床医学 | 1858篇 |
内科学 | 3963篇 |
皮肤病学 | 206篇 |
神经病学 | 1786篇 |
特种医学 | 503篇 |
外科学 | 2418篇 |
综合类 | 74篇 |
现状与发展 | 1篇 |
一般理论 | 12篇 |
预防医学 | 1305篇 |
眼科学 | 354篇 |
药学 | 948篇 |
中国医学 | 22篇 |
肿瘤学 | 1618篇 |
出版年
2024年 | 14篇 |
2023年 | 143篇 |
2022年 | 284篇 |
2021年 | 549篇 |
2020年 | 303篇 |
2019年 | 510篇 |
2018年 | 559篇 |
2017年 | 450篇 |
2016年 | 430篇 |
2015年 | 508篇 |
2014年 | 746篇 |
2013年 | 924篇 |
2012年 | 1322篇 |
2011年 | 1440篇 |
2010年 | 736篇 |
2009年 | 668篇 |
2008年 | 1219篇 |
2007年 | 1194篇 |
2006年 | 1066篇 |
2005年 | 1064篇 |
2004年 | 1010篇 |
2003年 | 892篇 |
2002年 | 804篇 |
2001年 | 108篇 |
2000年 | 79篇 |
1999年 | 111篇 |
1998年 | 144篇 |
1997年 | 116篇 |
1996年 | 108篇 |
1995年 | 106篇 |
1994年 | 77篇 |
1993年 | 68篇 |
1992年 | 47篇 |
1991年 | 42篇 |
1990年 | 46篇 |
1989年 | 42篇 |
1988年 | 35篇 |
1987年 | 30篇 |
1986年 | 28篇 |
1985年 | 30篇 |
1984年 | 28篇 |
1983年 | 33篇 |
1982年 | 32篇 |
1981年 | 21篇 |
1980年 | 19篇 |
1979年 | 21篇 |
1978年 | 11篇 |
1977年 | 11篇 |
1975年 | 6篇 |
1974年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Methicillin-resistant Staphylococcus aureus, Hawaii, 2000-2002 总被引:1,自引:0,他引:1
Li F Park SY Ayers TL Miller FD MacFadden R Nakata M Lee MC Effler PV 《Emerging infectious diseases》2005,11(8):1205-1210
The emergence of methicillin-resistant Staphylococcus aureus (MRSA) has generated considerable concern among medical and public health professionals. We used a statewide, population-based antimicrobial resistance surveillance system to examine epidemiologic trends for MRSA from outpatients and inpatients in Hawaii. Pediatric and adult patient populations were compared to assess characteristics of MRSA isolates specific for each group. From 2000 to 2002, 8,206 (26%) of 31,482 total S. aureus isolates were MRSA. During this period, the proportion of MRSA isolates increased in both outpatient and inpatient clinical settings (p<0.01). When stratified by age, annual trends showed a significant increase in the proportion of MRSA in adult patients (from 24% to 30%, p<0.01) but not in pediatric patients (from 25% to 27%, p>0.05). Although MRSA isolates from adults demonstrated high resistance to most non-beta-lactams, most MRSA isolates from pediatric outpatients remained susceptible to most non-beta-lactams. 相似文献
992.
Canine leishmaniasis, Italy 总被引:1,自引:0,他引:1
Ferroglio E Maroli M Gastaldo S Mignone W Rossi L 《Emerging infectious diseases》2005,11(10):1618-1620
We report the results of a survey to determine the prevalence of canine leishmaniasis and the presence of sand flies in northwestern Italy, where autochthonous foci of canine leishmaniasis have not been reported. Active foci of canine leishmaniasis were identified, which suggests that the disease is now also endemic in continental climate areas. 相似文献
993.
Grondona P Andreani SM Barr N Singh KK 《Surgical laparoscopy, endoscopy & percutaneous techniques》2005,15(5):263-266
Placement of a feeding jejunostomy tube is indicated for patients who need enteral access but where a gastrostomy is not feasible. This paper presents the technique and results of laparoscopic placement of feeding jejunostomy tubes in patients presenting with esophagogastric cancer. From December 2002 to February 2004, patients diagnosed with esophagogastric cancer with a potentially resectable lesion underwent staging laparoscopy. Laparoscopic feeding jejunostomy was performed on patients who were potential candidates for chemotherapy with palliative intent or neoadjuvant treatment prior to resection surgery. Surgical technique, recovery of bowel function, commencement of feeding jejunostomy, total time tube was in situ, and perioperative complications were analyzed. Of the 22 patients who underwent staging laparoscopy, a feeding jejunostomy tube was placed in 18. The remaining 4 patients were deemed to have advanced disease precluding any therapeutic options and underwent placement of esophageal stents. Feeding tubes remained in situ for a median time period of 76 days. Fourteen patients required enteral support and tubes were used for a median of 30 days. Complications from tube placement included 2 cases of wound infections, 1 of minor leak and 1 tube dislodgment. Patients were followed up for a median time of 112 days. Findings from current series suggest that placement of a feeding jejunostomy tube at the time of staging laparoscopy is a safe and reliable means of providing and maintaining nutrition for patients presenting with esophagogastric cancers. 相似文献
994.
Association between phonocardiographic third and fourth heart sounds and objective measures of left ventricular function 总被引:3,自引:0,他引:3
Marcus GM Gerber IL McKeown BH Vessey JC Jordan MV Huddleston M McCulloch CE Foster E Chatterjee K Michaels AD 《JAMA》2005,293(18):2238-2244
Context The third (S3) and fourth (S4) heart sounds detected by phonocardiography are considered to represent the criterion standards of the gallop sounds, but their test characteristics have not been explored. Objective To determine the diagnostic test characteristics of the S3 and S4 for prediction of left ventricular dysfunction using a computerized heart sound detection algorithm. Design, Setting, and Participants Prospective study of 90 adult patients undergoing elective left-sided heart catheterization at a single US teaching hospital between August 2003 and June 2004. The mean age was 62 (SD, 13) years (range, 24-90 years) and 61 (68%) were male. Within a 4-hour period, participants underwent computerized heart sound phonocardiographic analysis, cardiac catheterization, transthoracic echocardiography, and blood sampling for assessment of an S3/S4, left ventricular end-diastolic pressure (LVEDP), left ventricular ejection fraction (LVEF), and B-type natriuretic peptide (BNP), respectively. Main Outcome Measures Diagnostic test characteristics of the computerized phonocardiographic S3 and S4 using markers of left ventricular function as criterion standards. Results Mean (SD) LVEDP was significantly elevated (18.4 [6.9] mm Hg vs 12.1 [7.3] mm Hg; P<.001), mean (SD) LVEF was reduced (49.4% [20.2%] vs 63.6% [14.8%]; P<.001), and median (interquartile range) BNP was elevated (330 [98-1155] pg/mL vs 86 [41-192] pg/mL; P<.001) in those with an S3, S4, or both compared with patients without a diastolic heart sound. The sensitivities of these heart sounds to detect an elevated LVEDP, reduced LVEF, or elevated BNP were 41%, 52%, and 32% for an S3, and 46%, 43%, and 40% for an S4, respectively. For abnormal levels of the same markers of ventricular function, the specificities of the S3 were 92%, 87%, and 92%, while the specificities of the S4 were 80%, 72%, and 78%, respectively. Conclusions Neither the phonocardiographic S3 nor the S4 is a sensitive marker of left ventricular dysfunction. The phonocardiographic S3 is specific for left ventricular dysfunction and appears to be superior to the moderate specificity of the phonocardiographic S4. 相似文献
995.
Szafranski M Whittington JA Bessinger C 《Journal of the American Dietetic Association》2005,105(8):1295-1298
Studies have shown white beans to be an effective fat replacer in dropped cookies. However, research is needed to determine whether legumes may be an effective replacement for fat in other types of cookies. This study determined the overall acceptability, sensory characteristics, and nutrient content of brownies (bar cookie) made using cannellini beans as a replacement for shortening. Cannellini beans were used to replace 25%, 50%, and 75% of the shortening (by weight) in a control brownie formula. One hundred twenty untrained panelists participated in rating the brownies on a seven-point hedonic scale. Analysis of variance conducted on the acceptability and sensory characteristics indicated a statistically significant effect when replacing fat with beans for acceptability, tenderness, texture, and flavor (P<.05). Post-hoc testing (Scheffe's test) indicated that neither the 25% nor the 50% bean brownies were significantly different from the control in overall acceptability, tenderness, texture, or flavor. Also, the 50% bean brownies, compared with control, had 2.6 g less fat and 21 fewer kcal per 1.4-oz serving. This study demonstrated that pureed cannellini beans can replace as much as 50% of the fat (by weight) in brownies, while yielding an acceptable and more nutritious product. 相似文献
996.
Zabel EW Falken MC Sonnabend M Alms M Symonik D 《Journal of environmental health》2005,68(2):9-15, 36
The objectives of the study reported here were to determine the prevalence of elevated blood lead levels in rural Minnesota and to evaluate a lead-risk-screening questionnaire. Blood lead tests and lead risk questionnaires were obtained for a sample of 1,090 children younger than 48 months of age (72 percent of the eligible population) from three rural counties of west-central Minnesota between September 1, 2001, and August 31, 2002. It was found that overall, 2.4 percent of children in the study had blood lead levels of > or = 10 microg/dL (0.48 micromol/L) (results for capillary and venous tests combined), 0.9 percent had venous blood lead levels of > or = 10 microg/dL, and 0.5 percent of study participants had blood lead levels of > or = 20 microg/dL (0.96 micromol/L). Three risk factor questions, when taken together, predicted 90 percent of blood lead levels of > or = 10 microg/dL and all blood lead levels of > or = 20 microg/dL. The study estimated the prevalence of lead poisoning using a sample of the entire population rather than a clinic-based convenience sample. The authors conclude that targeted screening is an effective way to identify lead-poisoned children in rural areas of Minnesota. 相似文献
997.
Regression of glomerulosclerosis with high-dose angiotensin inhibition is linked to decreased plasminogen activator inhibitor-1 总被引:7,自引:0,他引:7
Ma LJ Nakamura S Aldigier JC Rossini M Yang H Liang X Nakamura I Marcantoni C Fogo AB 《Journal of the American Society of Nephrology : JASN》2005,16(4):966-976
The potential and possible mechanisms for regression of existing glomerulosclerosis by angiotensin II type 1 receptor antagonist (AT1RA) and/or angiotensin I converting enzyme inhibitor (ACEI) were investigated. Adult male Sprague Dawley rats underwent 5/6 nephrectomy (Nx). Glomerulosclerosis was assessed by renal biopsy 8 wk later, and rats were divided into groups with equal biopsy sclerosis and treated for the next 4 wk until they were killed at 12 wk as follows: Control with no further treatment (CONT), high-dose AT1RA, high-dose ACEI, and varying AT1RA+ACEI combinations. Hypertension and proteinuria induced by 5/6 Nx were significantly decreased by all treatments, except high-dose ACEI, which showed persistent proteinuria. High-dose AT1RA and ACEI markedly decreased progression of sclerosis, with -2.3% average decrease in sclerosis from biopsy to autopsy in AT1RA versus 194% increase in CONT (P < 0.0001). Glomerulosclerosis regressed, with less severe lesions at the time when the rats were killed than at biopsy in 62% of AT1RA-treated and 57% of ACEI-treated rats. In contrast, only 17 to 33% of rats in combination groups had regression. Alternatively, these data might be viewed as reflecting halting of progression, as some groups had higher BP and proteinuria. However, this potential confounding effect does not negate the effects to achieve regression of sclerosis in these rats. Regression was not explained by changes in mRNA of TGF-beta1 and matrix metalloproteinase-2 and -9 but was linked to decreased tissue inhibitor of metalloproteinase-1 and plasminogen activator inhibitor-1. It is concluded that angiotensin inhibition mediates regression in part by effects on matrix modulation. 相似文献
998.
Memoli B Grandaliano G Soccio M Postiglione L Guida B Bisesti V Esposito P Procino A Marrone D Michael A Andreucci M Schena FP Pertosa G 《Journal of the American Society of Nephrology : JASN》2005,16(4):1099-1107
Soluble gp130 (sgp130) is a soluble circulating receptor of IL-6 with "antagonistic" biologic activity. It is generated independently by either shedding of the extracellular domain of membrane gp130 or alternative mRNA splicing. This study was addressed to clarify the mechanisms underlying sgp130 synthesis and release in patients who undergo regular dialysis treatment (RDT) using dialytic membranes with different biocompatibility. Two groups of RDT patients were enrolled: 11 patients who were treated with cellulosic membranes (C) and 10 patients who were treated with synthetic membranes (S). Ten healthy subjects constituted the control group. Serum samples and peripheral blood mononuclear cells (PBMC) were harvested in all groups (before dialysis in RDT patients). PBMC were cultured for 24 h in the absence or presence of LPS. The serum levels of sgp130 were significantly higher in C group than in control and S patients (C, 603.1 +/- 89.9; control, 396 +/- 49.5; S, 423.4 +/- 27.7 ng/ml; P < 0.01). PBMC from C patients, in the absence of any mitogenic stimulation, released a significantly greater amount of sgp130 as compared with S and control groups (C, 532.6 +/- 161.2; S, 332.4 +/- 148.6; control, 341.4 +/- 125.4 pg/ml; P < 0.01). The sgp130 release was positively correlated with the release of both IL-6 (r = 0.336, P < 0.05) and sIL-6R receptor (r = 0.324, P < 0.05). A significantly higher gp130 gene expression was also observed in unstimulated PBMC from C patients when compared with control and S groups. It is interesting that the expression of the 85-bp exon characteristic of the alternative splicing mRNA for sgp130 was low in all groups. Finally, confocal microscopy analysis showed an increased expression of gp130 on cell surface in unstimulated PBMC from C patients as compared with control and S groups. Our results demonstrate that in patients on RDT with C membranes, the synthesis and release of sgp130 "antagonistic" receptor is significantly increased. This release is seemingly due to a shedding of membrane-bound gp130 receptor. The increased sgp130 release may partially counteract the inflammatory effects caused by IL-6. 相似文献
999.
1000.
Mirenda F La Spada M Baccellieri D Stilo F Benedetto F Spinelli F 《Chirurgia italiana》2005,57(6):731-735
The aim of the study was to evaluate iloprost infusion as an alternative to open surgical revascularisation in diabetic patients with foot ulcers, also as a support measure in conjunction with endovascular procedures. We studied 244 patients with critical ischaemia of the lower limbs, 146 of whom (59.8%) affected by diabetes. A femoro-distal bypass was performed in 175 patients. In the 69 nonsurgical diabetic patients (47.3% of the diabetics) an iloprost infusion was started. These diabetics presented foot ulcers, a palpable or slightly hypo-sphygmic popliteal pulse and high distal arterial flow at the ankle. In 55 of these patients (79.7% of those not operated on and 37.6% of the diabetics) who were non-responders to medical therapy, an endovascular procedure was also performed. The results of the iloprost infusion (69 pts.) were evaluated after one week. In 14 responders treated only with iloprost infusion, complete healing of the lesions occurred during the 3 weeks following the end of the 4-week course of therapy. No severe ischaemia recurrences were reported in the follow-up of these 69 patients. In the 47.3% of subjects with diabetic arteriopathy presenting foot ulcers and high distal flow, it proved possible to avoid an open surgical revascularisation procedure and to resort to medical therapy with iloprost, completed in 79.7% of cases with endovascular procedures. Iloprost infusion improves limb perfusion and, in selected cases may be an important therapeutic tool for the care of ulcerative lesions of the diabetic foot, also as a support measure in conjunction with endovascular procedures. 相似文献