全文获取类型
收费全文 | 18800篇 |
免费 | 1246篇 |
国内免费 | 74篇 |
专业分类
耳鼻咽喉 | 218篇 |
儿科学 | 420篇 |
妇产科学 | 345篇 |
基础医学 | 2585篇 |
口腔科学 | 321篇 |
临床医学 | 1627篇 |
内科学 | 4844篇 |
皮肤病学 | 412篇 |
神经病学 | 1632篇 |
特种医学 | 615篇 |
外科学 | 2659篇 |
综合类 | 238篇 |
一般理论 | 8篇 |
预防医学 | 1399篇 |
眼科学 | 415篇 |
药学 | 1115篇 |
3篇 | |
中国医学 | 77篇 |
肿瘤学 | 1187篇 |
出版年
2024年 | 51篇 |
2023年 | 142篇 |
2022年 | 341篇 |
2021年 | 551篇 |
2020年 | 323篇 |
2019年 | 447篇 |
2018年 | 515篇 |
2017年 | 342篇 |
2016年 | 364篇 |
2015年 | 449篇 |
2014年 | 619篇 |
2013年 | 838篇 |
2012年 | 1331篇 |
2011年 | 1347篇 |
2010年 | 773篇 |
2009年 | 664篇 |
2008年 | 1127篇 |
2007年 | 1195篇 |
2006年 | 1175篇 |
2005年 | 1105篇 |
2004年 | 1007篇 |
2003年 | 960篇 |
2002年 | 952篇 |
2001年 | 132篇 |
2000年 | 118篇 |
1999年 | 160篇 |
1998年 | 198篇 |
1997年 | 164篇 |
1996年 | 164篇 |
1995年 | 120篇 |
1994年 | 115篇 |
1993年 | 98篇 |
1992年 | 100篇 |
1991年 | 99篇 |
1990年 | 88篇 |
1989年 | 69篇 |
1988年 | 79篇 |
1987年 | 83篇 |
1986年 | 66篇 |
1985年 | 87篇 |
1984年 | 97篇 |
1983年 | 92篇 |
1982年 | 110篇 |
1981年 | 123篇 |
1980年 | 107篇 |
1979年 | 64篇 |
1978年 | 74篇 |
1977年 | 87篇 |
1976年 | 61篇 |
1974年 | 52篇 |
排序方式: 共有10000条查询结果,搜索用时 3 毫秒
991.
992.
993.
994.
995.
Zachary Bauman Victor Coba Marika Gassner David Amponsah John Gallien Dionne Blyden Keith Killu 《Journal of Ultrasound》2015,18(4):343-348
Purpose
Point-of-care ultrasound evaluates inferior vena cava (IVC) and internal jugular vein (IJV) measurements to estimate intravascular volume status. The reliability of the IVC and IJV collapsibility index during increased thoracic or intra-abdominal pressure remains unclear.Methods
Three phases of sonographic scanning were performed: spontaneous breathing phase, increased thoracic pressure phase via positive pressure ventilation (PPV) phase, and increased intra-abdominal pressure (IAP) phase via laparoscopic insufflation to 15 mmHg. IVC measurements were done at 1–2 cm below the diaphragm and IJV measurements were done at the level of the cricoid cartilage during a complete respiratory cycle. Collapsibility index was calculated by (max diameter − min diameter)/max diameter × 100 %. Chi square, t test, correlation procedure (CORR) and Fisher’s exact analyses were completed.Results
A total of 144 scans of the IVC and IJV were completed in 16 patients who underwent laparoscopic surgery. Mean age was 46 ± 15 years, with 75 % female and 69 % African-American. IVC and IJV collapsibility correlated in the setting of spontaneous breathing (r2 = 0.86, p < 0.01). IVC collapsibility had no correlation with the IJV in the setting of PPV (r2 = 0.21, p = 0.52) or IAP (r2 = 0.26, p = 0.42). Maximal IVC diameter was significantly smaller during increased IAP (16.5 mm ± 4.9) compared to spontaneous breathing (20.6 mm ± 4.8, p = 0.04) and PPV (21.8 mm ± 5.6, p = 0.01).Conclusion
IJV and IVC collapsibility correlated during spontaneous breathing but there was no statistically significant correlation during increased thoracic or intra-abdominal pressure. Increased intra-abdominal pressure was associated with a significant smaller maximal IVC diameter and cautions the reliability of IVC diameter in clinical settings that are associated with intra-abdominal hypertension or abdominal compartment syndrome. 相似文献996.
997.
A strategy to improve treatment‐related mortality and abandonment of therapy for childhood ALL in a developing country reveals the impact of treatment delays 下载免费PDF全文
Amaranto Suarez MD Martha Piña MD Diana X. Nichols‐Vinueza MD John Lopera MD Lyda Rengifo MD Mauricio Mesa MD Marcela Cardenas RN Lisa Morrissey RN Galo Veintemilla MD Martha Vizcaino MD Ligia Del Toro MD Victor Vicuna PhD Jorge Fernandez LICSW Donna Neuberg ScD Kristen Stevenson MS Alejandro Gutierrez MD 《Pediatric blood & cancer》2015,62(8):1395-1402
Background
Treatment‐related mortality and abandonment of therapy are major barriers to successful treatment of childhood acute lymphoblastic leukemia (ALL) in the developing world.Procedure
A collaboration was undertaken between Instituto Nacional de Cancerologia (Bogota, Colombia), which serves a poor patient population in an upper‐middle income country, and Dana‐Farber/Boston Children's Cancer and Blood Disorders Center (Boston, USA). Several interventions aimed at reducing toxic deaths and abandonment were implemented, including a reduced‐intensity treatment regimen and a psychosocial effort targeting abandonment. We performed a cohort study to assess impact.Results
The Study Population comprised 99 children with ALL diagnosed between 2007 and 2010, and the Historic Cohort comprised 181 children treated prior to the study interventions (1995–2004). Significant improvements were achieved in the rate of deaths in complete remission (13% to 3%; P = 0.005), abandonment (32% to 9%; P < 0.001), and event‐free survival with abandonment considered an event (47% to 65% at 2 years; P = 0.016). However, relapse rate did not improve. Medically unnecessary treatment delays were common, and landmark analysis revealed that initiating the PIII phase of therapy ≥4 weeks delayed predicted markedly inferior disease‐free survival (P = 0.016). Conversely, patients who received therapy without excessive delays had outcomes approaching those achieved in high‐income countries.Conclusions
Implementation of a twinning program was followed by reductions in abandonment and toxic deaths, but relapse rate did not improve. Inappropriate treatment delays were common and strongly predicted treatment failure. These findings highlight the importance of adherence to treatment schedule for effective therapy of ALL. Pediatr Blood Cancer 2015;62:1395–1402. © 2015 Wiley Periodicals, Inc. 相似文献998.
Emy Hiura Aline del Carmen Garcia Lopes Jeanne Saraiva da Paz Maylla Garschagen Gava Mayra Cunha Flecher Manuela Colares Filippe Elias de Freitas Soares Leandro Abreu da Fonseca Tracy Lacerda Jackson Victor de Araújo Fabio Ribeiro Braga 《Parasitology research》2015,114(9):3301-3308
The objective of this study was to evaluate the infectivity of Toxocara canis eggs after interacting with isolated nematophagous fungi of the species Duddingtonia flagrans (AC001) and Pochonia chlamydosporia (VC4), and test the predatory activity of the isolated AC001 on T. canis second stage larvae after 7 days of interaction. In assay A, 5000 embryonated T. canis eggs previously in contact with the AC001 and VC4 isolated for 10 days were inoculated into domestic chickens (Gallus gallus domesticus), and then these animals were necropsied to collect material (digested liver, intestine, muscles and lungs) at 3-, 7-, 14-, and 21-day intervals after inoculation. In assay A, the results demonstrated that the prior interaction of the eggs with isolated AC001 and VC4 decreases the amount of larvae found in the collected organs. Difference (p?<?0.01) was observed in the medium larvae counts recovered from liver, lung, intestine, and muscle of animals in the treated groups when compared to the animals in the control group. At the end of assay A, a percentage reduction of 87.1 % (AC001) and 84.5 % (VC4) respectively was recorded. In the result of assay B, the isolated AC001 showed differences (p?<?0.01) compared to the control group, with a reduction of 53.4 % in the recovery of L2. Through these results, it is justified to mention that prior interaction of embryonated T. canis eggs with the tested fungal isolates were efficient in reducing the development and migration of this parasite, in addition to the first report of proven predatory activity on L2. 相似文献
999.