全文获取类型
收费全文 | 624篇 |
免费 | 68篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 32篇 |
妇产科学 | 9篇 |
基础医学 | 54篇 |
口腔科学 | 9篇 |
临床医学 | 31篇 |
内科学 | 95篇 |
皮肤病学 | 19篇 |
神经病学 | 16篇 |
特种医学 | 141篇 |
外科学 | 162篇 |
综合类 | 20篇 |
预防医学 | 28篇 |
眼科学 | 29篇 |
药学 | 21篇 |
肿瘤学 | 38篇 |
出版年
2023年 | 7篇 |
2021年 | 8篇 |
2020年 | 9篇 |
2019年 | 7篇 |
2018年 | 17篇 |
2017年 | 8篇 |
2016年 | 14篇 |
2015年 | 18篇 |
2014年 | 16篇 |
2013年 | 18篇 |
2012年 | 8篇 |
2011年 | 23篇 |
2010年 | 28篇 |
2009年 | 34篇 |
2008年 | 23篇 |
2007年 | 42篇 |
2006年 | 35篇 |
2005年 | 27篇 |
2004年 | 23篇 |
2003年 | 11篇 |
2002年 | 12篇 |
2001年 | 17篇 |
2000年 | 9篇 |
1999年 | 5篇 |
1998年 | 23篇 |
1997年 | 37篇 |
1996年 | 23篇 |
1995年 | 24篇 |
1994年 | 16篇 |
1993年 | 7篇 |
1992年 | 7篇 |
1990年 | 8篇 |
1989年 | 13篇 |
1988年 | 9篇 |
1987年 | 15篇 |
1986年 | 12篇 |
1985年 | 12篇 |
1984年 | 6篇 |
1983年 | 10篇 |
1982年 | 7篇 |
1981年 | 9篇 |
1980年 | 12篇 |
1978年 | 4篇 |
1977年 | 7篇 |
1976年 | 9篇 |
1975年 | 7篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1967年 | 1篇 |
1946年 | 1篇 |
排序方式: 共有705条查询结果,搜索用时 15 毫秒
31.
AG Eller TF Porter P Soisson RM Silver 《BJOG : an international journal of obstetrics and gynaecology》2009,116(5):648-654
Objective To determine which interventions for managing placenta accreta were associated with reduced maternal morbidity.
Design Retrospective cohort study.
Setting Two tertiary care teaching hospitals in Utah.
Population All identified cases of placenta accreta from 1996 to 2008.
Methods Cases of placenta accreta were identified using standard ICD-9 codes for placenta accreta, placenta praevia, and caesarean hysterectomy. Medical records were then abstracted for maternal medical history, hospital course, and maternal and neonatal outcomes. Maternal and neonatal complications were compared according to antenatal suspicion of accreta, indications for delivery, preoperative preparation, attempts at placental removal before hysterectomy, and hypogastric artery ligation.
Main outcome measures Early morbidity (prolonged maternal intensive care unit admission, large volume of blood transfusion, coagulopathy, ureteral injury, or early re-operation) and late morbidity (intra-abdominal infection, hospital re-admission, or need for delayed re-operation).
Results Seventy-six cases of placenta accreta were identified. When accreta was suspected, scheduled caesarean hysterectomy without attempting placental removal was associated with a significantly reduced rate of early morbidity compared with cases in which placental removal was attempted (67 versus 36%, P = 0.038). Women with preoperative bilateral ureteric stents had a lower incidence of early morbidity compared with women without stents (18 versus 55%, P = 0.018). Hypogastric artery ligation did not reduce maternal morbidity.
Conclusions Scheduled caesarean hysterectomy with preoperative ureteric stent placement and avoiding attempted placental removal are associated with reduced maternal morbidity in women with suspected placenta accreta. 相似文献
Design Retrospective cohort study.
Setting Two tertiary care teaching hospitals in Utah.
Population All identified cases of placenta accreta from 1996 to 2008.
Methods Cases of placenta accreta were identified using standard ICD-9 codes for placenta accreta, placenta praevia, and caesarean hysterectomy. Medical records were then abstracted for maternal medical history, hospital course, and maternal and neonatal outcomes. Maternal and neonatal complications were compared according to antenatal suspicion of accreta, indications for delivery, preoperative preparation, attempts at placental removal before hysterectomy, and hypogastric artery ligation.
Main outcome measures Early morbidity (prolonged maternal intensive care unit admission, large volume of blood transfusion, coagulopathy, ureteral injury, or early re-operation) and late morbidity (intra-abdominal infection, hospital re-admission, or need for delayed re-operation).
Results Seventy-six cases of placenta accreta were identified. When accreta was suspected, scheduled caesarean hysterectomy without attempting placental removal was associated with a significantly reduced rate of early morbidity compared with cases in which placental removal was attempted (67 versus 36%, P = 0.038). Women with preoperative bilateral ureteric stents had a lower incidence of early morbidity compared with women without stents (18 versus 55%, P = 0.018). Hypogastric artery ligation did not reduce maternal morbidity.
Conclusions Scheduled caesarean hysterectomy with preoperative ureteric stent placement and avoiding attempted placental removal are associated with reduced maternal morbidity in women with suspected placenta accreta. 相似文献
32.
33.
Michael A den Bakker Angela AG van Tilborg Johan M Kros Ellen C Zwarthoff 《Neuropathology》2001,21(3):168-173
Neurofibromatosis type 2 is caused by mutations in the NF2 tumor suppressor gene. The NF2 gene encodes a 595‐aminoacid protein, presumably functioning as a membrane‐organizing element. Theoretically, the majority of mutations found in the NF2 gene should lead to a truncated protein product. Using immunoprecipitation with an antibody raised to N‐terminal sequences of the NF2 protein, the authors sought to demonstrate the presence of truncated NF2 proteins in tumors. From 17 of 19 tumors (14 meningiomas and five schwannomas), 12 of which have previously been shown to harbor truncating NF2 mutations, wild‐type NF2 protein was immunopreci‐pitated. From two tumors no protein was precipitated. Truncated NF2 proteins were not observed. The authors conclude that mutant NF2 proteins are unstable and undergo accelerated degradation. 相似文献
34.
We have read the recent comprehensive review by Cruz et al.[1] regarding the targeting of receptor tyrosine kinases andtheir therapeutic perspectives in head and neck squamous cellcarcinomas (HNSCC). The major focus of this report was epidermalgrowth factor receptor (EGFR) biology and targeting. However,we feel 相似文献
35.
36.
JR Skinner AG Stuart J O'Sullivan A Heads RJ Boys S Hunter 《Archives of disease in childhood》1993,69(2):216-220
Doppler and direct measurements of right ventricle to right atrial pressure drop were made during cardiac catheterisation on 28 occasions in 26 infants with congenital heart disease. Age was 10 days to 12 months (median 4.5 months), and weight was 3.1 to 9.0 kg (median 4.7 kg). We measured peak velocity of tricuspid regurgitation by continuous wave Doppler, and the pressure drop was calculated using the modified Bernoulli equation (delta p = 4v2). There was a high correlation (r = 0.95) between direct and Doppler measurements. Doppler values tended to underestimate the right ventricle to right atrial pressure drop, but this was not of clinical significance (mean 2 mm Hg). The 95% confidence interval for the Doppler velocity was -0.41 to +0.26 m/sec, and was consistent across the range of pressures studied. Variability between observers was tested, by two observers performing sequential paired examinations on 16 newborn babies with tricuspid regurgitation. The coefficient of repeatability was 6.3 mm Hg (95% confidence interval 4.7 to 9.5 mm Hg) or 0.26 m/sec (0.18 to 0.50 m/sec). This method of right ventricular pressure estimation, validated previously only in older children and adults, is a reproducible and accurate technique in infants with tricuspid regurgitation. 相似文献
37.
In a patient with primary hyperparathyroidism an attempt was made to ablate a middle mediastinal parathyroid gland by forceful staining with radiographic contrast material. The gland was stained on two separate occasions, two weeks apart. Both times the serum calcium level temporarily fell to the normal range but reverted to abnormal levels. The patient ultimately required surgery for correction of hypercalcemia. The mechanism of staining and possible reasons for failure as well as potential complications are discussed. 相似文献
38.
39.
40.
Frequencies of inherited organic acidurias and disorders of mitochondrial fatty acid transport and oxidation in Germany 总被引:6,自引:0,他引:6
Hoffmann GF von Kries R Klose D Lindner M Schulze A Muntau AC Röschinger W Liebl B Mayatepek E Roscher AA 《European journal of pediatrics》2004,163(2):76-80
The lack of epidemiological data on the frequency and/or burden of organic acidurias (OA) and mitochondrial fatty acid transport and oxidation disorders (mtFATOD) is one reason for hesitation to expand newborn screening (NBS) by tandem mass spectrometry (MS-MS). From 1999 to 2000, the frequency of ten potentially treatable OA and mtFATOD was assessed by active nation-wide surveillance on cases presenting with clinical symptoms using the German Paediatric Surveillance Unit (ESPED) system. Case ascertainment was complemented by a second independent source: 3-monthly inquiries in the metabolic laboratories performing secondary selected screening for OA and mtFATOD. Frequency estimates for clinically symptomatic cases older than 7 days in a birth cohort of 844,575 conventionally screened children was compared to the frequency found in a cohort of 382,247 screened by MS-MS in Bavaria and Baden-Württemberg. The overall frequency of the ten conditions considered was 1:8,000 (95% CI 1:11,000–1:6,000) by MS-MS as compared to 1:23,000 (95% CI 1:36,000–1:17,000) in symptomatic cases presenting mainly with metabolic crisis. The contributions of medium-chain acyl-CoA dehydrogenase deficiency (MCADD), other mtFATOD and OA were 29, 4 and 13 among the 46 cases identified by MS-MS, and 19, 1 and 13 among the 33 clinically symptomatic cases, respectively. Acute metabolic crisis, with a lethal outcome in four patients, was reported for 22/33 clinically symptomatic cases. No clinically symptomatic cases were reported from cohorts with screened by MS-MS. Conclusion: ten potentially treatable organic acidurias and mitochondrial fatty acid transport and oxidations disorders were more common than phenylketonuria with organic acidurias accounting for 28% of the cases detected by newborn screening and 39% of the cases identified on high risk screening. These conditions were related to considerable morbidity and mortality. Considerations for their inclusion in expanded newborn screening programmes might be warranted.Abbreviations
ESPED
Erhebungseinheit für seltene pädiatrische Erkrankungen in Deutschland (German Paediatric Surveillance Unit)
-
MCADD
medium-chain acyl-CoA dehydrogenase deficiency
-
MS-MS
tandem mass spectrometry
-
mtFATOD
mitochondrial fatty acid transport and oxidation disorders
-
NBS
newborn screening
-
OA
organic acidurias 相似文献