全文获取类型
收费全文 | 5010篇 |
免费 | 376篇 |
国内免费 | 26篇 |
专业分类
耳鼻咽喉 | 59篇 |
儿科学 | 194篇 |
妇产科学 | 148篇 |
基础医学 | 679篇 |
口腔科学 | 120篇 |
临床医学 | 661篇 |
内科学 | 881篇 |
皮肤病学 | 128篇 |
神经病学 | 622篇 |
特种医学 | 116篇 |
外科学 | 516篇 |
综合类 | 43篇 |
一般理论 | 2篇 |
预防医学 | 469篇 |
眼科学 | 37篇 |
药学 | 318篇 |
中国医学 | 7篇 |
肿瘤学 | 412篇 |
出版年
2024年 | 7篇 |
2023年 | 79篇 |
2022年 | 122篇 |
2021年 | 154篇 |
2020年 | 128篇 |
2019年 | 166篇 |
2018年 | 184篇 |
2017年 | 157篇 |
2016年 | 174篇 |
2015年 | 184篇 |
2014年 | 205篇 |
2013年 | 304篇 |
2012年 | 391篇 |
2011年 | 385篇 |
2010年 | 190篇 |
2009年 | 189篇 |
2008年 | 334篇 |
2007年 | 309篇 |
2006年 | 254篇 |
2005年 | 254篇 |
2004年 | 231篇 |
2003年 | 212篇 |
2002年 | 204篇 |
2001年 | 41篇 |
2000年 | 30篇 |
1999年 | 48篇 |
1998年 | 47篇 |
1997年 | 39篇 |
1996年 | 19篇 |
1995年 | 20篇 |
1994年 | 32篇 |
1993年 | 23篇 |
1992年 | 20篇 |
1991年 | 24篇 |
1990年 | 21篇 |
1989年 | 17篇 |
1988年 | 17篇 |
1987年 | 9篇 |
1986年 | 16篇 |
1985年 | 11篇 |
1984年 | 17篇 |
1983年 | 11篇 |
1982年 | 16篇 |
1981年 | 9篇 |
1980年 | 17篇 |
1979年 | 11篇 |
1978年 | 16篇 |
1976年 | 8篇 |
1975年 | 6篇 |
1973年 | 10篇 |
排序方式: 共有5412条查询结果,搜索用时 15 毫秒
41.
Prospective Study Comparing Two Brands of Cohesive Gel Breast Implants with Anatomic Shape: 5-Year Follow-Up Evaluation 总被引:1,自引:0,他引:1
BACKGROUND : The new generation of breast implants has an anatomic shape. These implants are made with a textured shell and filled with a cohesive silicone gel. Available since 1993 except in the United States, these implants are gaining in popularity for breast enlargement and reconstruction. This prospective, randomized, controlled, and blinded study was designed to compare mid- and long-term results with the use of cohesive gel-filled implants from two different manufacturers: Style 410 of the McGhan brand (MG) made by Allergan and Vertex made by Eurosilicone (ES). METHODS: From May 1997 to May 1999, 80 women underwent breast augmentation: 40 with Style 410 implants (MG) and 40 with Vertex implants (ES). All surgeries were performed by the same surgeon (I.N.). Another physician (G.J.) interviewed and examined 64 of these women (80%) 4 to 6 years (median, 5 years) after implantation. In addition, 10 patients responded to the same questionnaire and were interviewed by phone, bringing the follow-up rate to 92.5%. RESULTS: Overall, satisfaction was high, with 98.6% of the patients evaluated after 4 to 6 years "very satisfied" or "satisfied" with the result in general. Approximately 20% of the patients who responded judged their breasts to be firmer than desirable. Breast augmentation classification (BAC) was used to grade the breast firmness of the 64 patients examined by G. J. At examination, 24% of patients had soft breasts, 53% had slightly firm breasts, and 23% had moderately firm breasts. That last category also was classified as capsular contracture. No patient was graded as having very hard breasts (BAC 4). Skin sensitivity of the breast adjacent to the incision was altered for 25% of the patients. The implant rotated in four patients (5%). Breast firmness, implant palpability, nipple sensitivity, and skin sensitivity were further analyzed by implant location (submuscular vs subglandular) and implant size (volume). Frequency of the breast asymmetries and the impact of augmentation on asymmetric breasts also was studied. All these analyses were performed with the entire pool of examined patients who answered the follow-up questionnaire. Data also were analyzed by distinguishing between results of the two each implant manufacturers. The results showed no difference between the Eurosilicone and McGhan implants except for the self-evaluation of "breast consistency" by the patient. A higher percentage of patients with the Vertex implants than with the McGhan implants reported that their breast was "firmer than desired." CONCLUSIONS: Breast augmentation with anatomic, textured, cohesive silicone gel-filled implants is a reliable procedure with consistently good results. The results also show that candidates for breast enlargement should be informed that their implanted breast may feel firmer than their natural breasts. They also may experience reduced sensation of their nipple or breast skin. 相似文献
42.
BACKGROUND: There is a paucity of data regarding whether sterile handling of endotracheal tubes (ETTs) impacts the incidence and prevalence of pneumonia in the emergency, urgent, or elective clinical scenarios. Intensive care units employ infection control and reduction schemes to reduce pneumonia rates. METHODS: A MEDLINE search of the English-language literature for the last 30 years was performed using the keywords "endotracheal intubation," "intubation," "pneumonia," "sinusitis," "tracheobronchitis," "nosocomial infection," and "infection." Data were limited to those papers addressing the role of sterile handling or passage of ETTs, infection with antibiotic-resistant micro-organisms, antibiotic prophylaxis, and the role of virulence determinants in supporting invasive infection. Also, a convenience sample of a single author's patients requiring tracheal intubation was undertaken. Data were acquired on tube handling, success of insertion, and subsequent occurrence of pneumonia. RESULTS: Virtually no data exist on the impact of sterile ETT handling, but unsterile manipulation of the ETT prior to insertion is common (112 of 154 intubation events). Within the limited patient sample, no conclusions may be drawn regarding the impact of unsterile handling on pneumonia rates, although sinusitis after nasotracheal intubation clearly increases the incidence of pneumonia. Biofilm generation as a facilitator of bacterial colonization of artificial airway surfaces is a ubiquitous virulence determinant that is not ameliorated by antibiotic administration. CONCLUSIONS: Unsterile ETT handling and insertion techniques are not clearly associated with pneumonia induction, but physiologically sound approaches that retard biofilm production may decrease pneumonia rates. 相似文献
43.
44.
Byberg L Gedeborg R Cars T Sundstr?m J Berglund L Kilander L Melhus H Micha?lsson K 《Journal of bone and mineral research》2012,27(4):797-807
FRAX is a tool that identifies individuals with high fracture risk who will benefit from pharmacological treatment of osteoporosis. However, a majority of fractures among elderly occur in people without osteoporosis and most occur after a fall. Our aim was to accurately identify men with a high future risk of fracture, independent of cause. In the population‐based Uppsala Longitudinal Study of Adult Men (ULSAM) and using survival analysis we studied different models' prognostic values (R2) for any fracture and hip fracture within 10 years from age 50 (n = 2322), 60 (n = 1852), 71 (n = 1221), and 82 (n = 526) years. During the total follow‐up period from age 50 years, 897 fractures occurred in 585 individuals. Of these, 281 were hip fractures occurring in 189 individuals. The rates of any fracture were 5.7/1000 person‐years at risk from age 50 years and 25.9/1000 person‐years at risk from age 82 years. Corresponding hip fractures rates were 2.9 and 11.7/1000 person‐years at risk. The FRAX model included all variables in FRAX except bone mineral density. The full model combining FRAX variables, comorbidity, medications, and behavioral factors explained 25% to 45% of all fractures and 80% to 92% of hip fractures, depending on age. The corresponding prognostic values of the FRAX model were 7% to 17% for all fractures and 41% to 60% for hip fractures. Net reclassification improvement (NRI) comparing the full model with the FRAX model ranged between 40% and 53% for any fracture and between 40% and 87% for hip fracture. Within the highest quintile of predicted fracture risk with the full model, one‐third of the men will have a fracture within 10 years after age 71 years and two‐thirds after age 82 years. We conclude that the addition of comorbidity, medication, and behavioral factors to the clinical components of FRAX can substantially improve the ability to identify men at high risk of fracture, especially hip fracture. © 2012 American Society for Bone and Mineral Research. 相似文献
45.
Hillman M Eriksson L Mared L Helgesson K Landin-Olsson M 《Journal of cystic fibrosis》2012,11(2):144-149
Glucagon like peptide 1 (GLP-1) is an incretin hormone released as a bioactive peptide from intestinal L-cells in response to eating. It acts on target cells and exerts several functions as stimulating insulin and inhibiting glucagon. It is quickly deactivated by the serine protease dipeptidyl peptidase IV (DPP-IV) as an important regulatory mechanism. GLP-1 analogues are used as antidiabetic drugs in patients with type 2 diabetes. We served patients with cystic fibrosis (CF, n=29), cystic fibrosis related diabetes (CFRD, n=19) and healthy controls (n=18) a standardized breakfast (23 g protein, 25 g fat and 76 g carbohydrates) after an overnight fasting. Blood samples were collected before meal as well as 15, 30, 45 and 60 min after the meal in tubes prefilled with a DPP-IV inhibitor. The aim of the study was to compare levels of GLP-1 in patients with CF, CFRD and in healthy controls. We found that active GLP-1 was significantly decreased in patients with CF and CFRD compared to in healthy controls (p<0.01). However, levels in patients with CFRD tended to be lower but were not significantly lower than in patients with CF without diabetes (p=0.06). Total GLP-1 did not differ between the groups, which points to that the inactive form of GLP-1 is more pronounced in CF patients. The endogenous insulin production (measured by C-peptide) was significantly lower in patients with CFRD as expected. However, levels in non-diabetic CF patients did not differ from the controls. We suggest that the decreased levels of GLP-1 could affect the progression toward CFRD and that more studies need to be performed in order to evaluate a possible treatment with GLP-1 analogues in CF-patients. 相似文献
46.
Swedish Arrhythmia Surgery Group Ahlsson A Jidéus L Albåge A Källner G Holmgren A Boano G Hermansson U Kimblad PO Scherstén H Sjögren J Ståhle E Aberg B Berglin E 《Scandinavian cardiovascular journal : SCJ》2012,46(4):212-218
Atrial fibrillation (AF) is a common arrhythmia among patients scheduled for open heart surgery and is associated with increased morbidity and mortality. According to international guidelines, symptomatic and selected asymptomatic patients should be offered concomitant surgical AF ablation in conjunction with valvular or coronary surgery. The gold standard in AF surgery is the Cox Maze III ("cut-and-sew") procedure, with surgical incisions in both atria according to a specified pattern, in order to prevent AF reentry circuits from developing. Over 90% of patients treated with the Cox Maze III procedure are free of AF after 1 year. Recent developments in ablation technology have introduced several energy sources capable of creating nonconducting atrial wall lesions. In addition, simplified lesion patterns have been suggested, but results with these techniques have been unsatisfactory. There is a clear need for standardization in AF surgery. The Swedish Arrhythmia Surgery Group, represented by surgeons from all Swedish units for cardiothoracic surgery, has therefore reached a consensus on surgical treatment of concomitant AF. This consensus emphasizes adherence to the lesion pattern in the Cox Maze III procedure and the use of biatrial lesions in nonparoxysmal AF. 相似文献
47.
Lindholm L Bengtsson A Hansdottir V Lundqvist M Rosengren L Jeppsson A 《Journal of cardiothoracic and vascular anesthesia》2003,17(2):182-187
OBJECTIVE: To evaluate the role of target temperature (28 degrees or 34 degrees C) in cardiac surgery on regional oxygenation during hypothermia and rewarming and systemic inflammatory response. DESIGN: Prospective, controlled, and randomized clinical study. SETTING: University hospital. PARTICIPANTS: Elderly patients (mean age 70 +/- 2 years) with acquired heart disease with an anticipated bypass time exceeding 120 minutes (n = 30). INTERVENTIONS: The patients were cooled to either 28 degrees C (n = 15) or 34 degrees C (n = 15). At hypothermia, bypass blood flow was reduced twice from full flow (2.4 L/min/m(2) body surface area [BSA]) to 2.0 L/min/m(2). MEASUREMENTS AND MAIN RESULTS: Hepatic and jugular venous oxygen tension and saturation were higher at 28 degrees C than at 34 degrees C. In comparison with the preoperative values, at 28 degrees C hepatic venous values were higher; whereas at 34 degrees C, they were lower. The reduction of pump blood flow during hypothermia, from 2.4 to 2.0 L/min/m(2)was accompanied by reductions of central, jugular, and hepatic oxygenation at both target temperatures. During rewarming, central and regional venous oxygenation decreased irrespective of the preceding temperature. The decrease was most pronounced in hepatic venous blood, with the lowest individual values <10%. Serum concentrations of C3a and IL-6 increased during hypothermia and increased further during rewarming irrespective of the preceding temperature. CONCLUSION: During cardiopulmonary bypass, hypothermia at 28 degrees C increases regional and central venous oxygenation better than at 34 degrees C. In contrast, venous oxygenation decreases during rewarming irrespective of the preceding temperature. No significant difference in the systemic inflammatory response associated with target temperature was detected. 相似文献
48.
Inhibitory smads and tgf-Beta signaling in glomerular cells 总被引:9,自引:0,他引:9
Schiffer M Schiffer LE Gupta A Shaw AS Roberts IS Mundel P Böttinger EP 《Journal of the American Society of Nephrology : JASN》2002,13(11):2657-2666
Smad6 and Smad7 are inhibitory SMADs with putative functional roles at the intersection of major intracellular signaling networks, including TGF-beta, receptor tyrosine kinase (RTK), JAK/STAT, and NF-kappaB pathways. This study reports differential functional roles and regulation of Smad6 and Smad7 in TGF-beta signaling in renal cells, in murine models of renal disease and in human glomerular diseases. Smad7 is upregulated in podocytes in all examined glomerular diseases (focal segmental glomerulosclerosis [FSGS], minimal-change disease [MCD], membranous nephropathy [MNP], lupus nephritis [LN], and diabetic nephropathy [DN]) with a statistically significant upregulation in "classical" podocyte-diseases such as FSGS and MCD. TGF-beta induces Smad7 synthesis in cultured podocytes and Smad6 synthesis in cultured mesangial cells. Although Smad7 expression inhibited both Smad2- and Smad3-mediated TGF-beta signaling in podocytes, it inhibited only Smad3 but not Smad2 signaling in mesangial cells. In contrast, Smad6 had no effect on TGF-beta/Smad signaling in podocytes and enhanced Smad3 signaling in mesangial cells. These data suggest that Smad7 is activated in injured podocytes in vitro and in human glomerular disease and participates in negative control of TGF-beta/Smad signaling in addition to its pro-apoptotic activity, whereas Smad6 has no role in TGF-beta response and injury in podocytes. In contrast, Smad6 is upregulated in the mesangium in human glomerular diseases and may be involved in functions independent of TGF-beta/Smad signaling. These data indicate an important role for Smad6 and Smad7 in glomerular cells in vivo that could be important for the cell homeostasis in physiologic and pathologic conditions. 相似文献
49.
Expanding access to transplantation with hepatitis C‐positive donors: A new perspective on an old issue 下载免费PDF全文
Catherine E. Kling Ajit P. Limaye Charles S. Landis Lena Sibulesky 《Clinical transplantation》2017,31(2)
With the need for organs far exceeding supply, donors previously exposed to hepatitis B (HBV) and hepatitis C (HCV) viral infections should be considered for transplantation. Although many centers have protocols for transplanting organs from HBV core antibody‐positive (HBcAb+) donors into select recipients, in the era of direct‐acting antivirals (DAAs), a new focus should be placed on HCV‐positive donors. The transmission rate from HCV antibody‐positive (HCVAb+) nucleic acid testing negative (HCV NAT‐) donors is expected to be very low, and we encourage use of such organs in HCV recipients provided a normal biopsy, appropriate counseling, and careful post‐transplant monitoring. While transmission of HCV from HCV NAT+ donors is universal, the success of DAA in obtaining a sustained viral response in post‐transplant recipients should make the use of these organs more appealing. We herein provide information to help guide the use of organs from HCV donors. 相似文献
50.
Perger L Watch L Weinsheimer R Fahl J Azzie G 《Journal of laparoendoscopic & advanced surgical techniques. Part A》2008,18(1):136-139
BACKGROUND/PURPOSE: Children with gastroesophageal reflux disease (GERD) often have associated feeding difficulties that warrant the insertion of a feeding gastrostomy at the time of the antireflux procedure. Options for gastrostomy tube insertion at the time of laparoscopic Nissen fundoplication (LNF) include laparoscopic gastrostomy, percutaneous endoscopic gastrostomy (PEG), and classic open gastrostomy. The complication rate of PEG may be decreased if it is placed under laparoscopic supervision. The purpose of this paper is to describe our experience with laparoscopically supervised PEG tube placement at the time of antireflux procedure. METHODS: A retrospective chart review was conducted on all children undergoing a PEG tube placement at the time of the LNF. Perioperative complications were recorded. RESULTS: Forty-four patients had attempted PEG tube placement at the time of the LNF. In 3 (7%) cases, laparoscopic supervision was crucial in the prevention of a complication. No major PEG-related complications were recorded. In 43% of patients, minor PEG tube problems arose in the postoperative period: all were transient and/or easily correctable. Management of all these problems was in an outpatient setting. Follow-up ranged from 11 to 41 months. CONCLUSIONS: PEG tube placement at the time of a LNF is safe and effective. A combined laparoscopic and endoscopic approach minimizes complications. This method also allows for an intra- and extraluminal evaluation of the fundoplication at its completion. 相似文献