全文获取类型
收费全文 | 3110篇 |
免费 | 152篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 54篇 |
儿科学 | 54篇 |
妇产科学 | 29篇 |
基础医学 | 361篇 |
口腔科学 | 61篇 |
临床医学 | 293篇 |
内科学 | 595篇 |
皮肤病学 | 45篇 |
神经病学 | 289篇 |
特种医学 | 224篇 |
外科学 | 532篇 |
综合类 | 23篇 |
一般理论 | 4篇 |
预防医学 | 215篇 |
眼科学 | 76篇 |
药学 | 148篇 |
中国医学 | 1篇 |
肿瘤学 | 269篇 |
出版年
2024年 | 30篇 |
2023年 | 58篇 |
2022年 | 106篇 |
2021年 | 158篇 |
2020年 | 96篇 |
2019年 | 123篇 |
2018年 | 139篇 |
2017年 | 96篇 |
2016年 | 107篇 |
2015年 | 147篇 |
2014年 | 142篇 |
2013年 | 154篇 |
2012年 | 222篇 |
2011年 | 199篇 |
2010年 | 121篇 |
2009年 | 96篇 |
2008年 | 141篇 |
2007年 | 159篇 |
2006年 | 103篇 |
2005年 | 117篇 |
2004年 | 114篇 |
2003年 | 66篇 |
2002年 | 79篇 |
2001年 | 35篇 |
2000年 | 36篇 |
1999年 | 34篇 |
1998年 | 16篇 |
1997年 | 17篇 |
1996年 | 9篇 |
1995年 | 9篇 |
1994年 | 12篇 |
1993年 | 6篇 |
1992年 | 27篇 |
1991年 | 32篇 |
1990年 | 24篇 |
1989年 | 21篇 |
1988年 | 18篇 |
1987年 | 17篇 |
1986年 | 20篇 |
1985年 | 14篇 |
1984年 | 12篇 |
1983年 | 12篇 |
1981年 | 8篇 |
1979年 | 12篇 |
1973年 | 11篇 |
1972年 | 8篇 |
1971年 | 6篇 |
1969年 | 6篇 |
1968年 | 8篇 |
1967年 | 7篇 |
排序方式: 共有3273条查询结果,搜索用时 15 毫秒
81.
82.
BACKGROUND: Identification of risks for development of ventilator-associated pneumonia (VAP), which might be identified early after injury, would allow for prognostic estimates and targeting of high-risk cohorts for clinical trials of preventive strategies. This study was performed to develop an equation that can be applied to estimate the probability of pneumonia based on parameters collected in the early postinjury interval. METHODS: Over a 28-month period, patient admissions were reviewed for mechanism and severity of injury, patterns of injury, shock, and need for emergent intubation. Early deaths (<48 hours) were excluded. VAP diagnosis required > or = 10(5) colony-forming units/mL organisms in the bronchoalveolar lavage effluent. Multiple logistic regression analysis was used to develop the prediction equation and estimate odds ratios. The equation was then tested on consecutive patients admitted over a 2-month period. RESULTS: We reviewed 9,721 admissions (77% blunt, 23% penetrating). VAP incidence was 5.6%. Overall mortality was 2% (21% for patients with VAP vs. 1% for no VAP; p < 0.0001). Multiple logistic regression analysis for all patients produced the following equation: f(x) = -3.08 - 1.56 (MOI) - 0.12 (GCS) + 1.37 (SCI) + 0.30 (chest AIS) + 1.87 (lap) + 0.67 (tx) + 0.05 (ISS) + 0.66 (int), where MOI is mechanism of injury (penetrating = 1, blunt = 0), GCS is Glasgow Coma Scale score, SCI is spinal cord injury (yes = 1, no = 0), lap is emergent laparotomy (yes = 1, no = 0), ISS is Injury Severity Score, tx is units of blood transfused in the resuscitation room, and int is intubation in either the field or the resuscitation room (yes = 1, no = 0). The probability of VAP was calculated as follows: P(VAP) = e(f)(x)/1 + e(f)(x). This formula was concordant in 95% and discordant in 5%. CONCLUSION: It is possible to accurately predict risk for VAP in trauma patients based on data available early after injury. This calculation could be useful for counseling families relative to prognosis and research protocols, and addressing hospitalization issues with third-party payors. 相似文献
83.
White WM Baldassano M Rajadhyaksha M Gonzalez S Tearney GJ Anderson RR Fabian RL 《Archives of otolaryngology--head & neck surgery》2004,130(8):923-928
BACKGROUND: Confocal reflectance microscopy (CRM) is an optical method of imaging tissue noninvasively without the need for fixation, sectioning, and staining as in standard histopathologic analysis. Image contrast is determined by natural differences in refractive indices of organelles and other subcellular structures within the tissues. Gray-scale images are displayed in real time on a video monitor and represent horizontal (en face) optical sections through the tissue. We hypothesized that CRM is capable of discerning histologic characteristics of different tissues in the head and neck. OBJECTIVES: To examine the microscopic anatomy of freshly excised head and neck surgical specimens en bloc using CRM and to compare the findings with those generated by conventional histologic analysis. DESIGN: This was a pilot observational cohort study. Bone, muscle, nerve, thyroid, parotid, and ethmoid mucosa from human surgical specimens were imaged immediately after excision. Confocal images were compared with corresponding routine paraffin-embedded, hematoxylin-eosin-stained sections obtained from the same tissue. RESULTS: Characteristic histologic features of various tissues and cell types were readily discernible by CRM and correlated well with permanent sections. However, in all tissues examined, there was less microscopic detail visible in the CRM images than was appreciated in paraffin-embedded histologic sections. CONCLUSIONS: The CRM images revealed cytologic features without the artifacts of histologic processing and thus may have the potential for use as an adjunct to frozen-section analysis in intraoperative consultation. 相似文献
84.
We report on transient hyperinsulinism (HI), presenting as severe congenital HI, in two neonates born without intrauterine growth restriction, maternal diabetes, perinatal asphyxia or Rhesus/platelet isoimmunisation. The neonates developed early (<6 h of life), symptomatic, non-ketotic hypoglycaemia (0–0.66 mmol/l), associated with elevated insulin levels (40–200 mU/l), and required high glucose infusion rates (22–24 mg/kg per min) to maintain normoglycaemia. However, both babies were diazoxide-sensitive and did not require glucose infusions beyond 2 weeks of life. Neither neonate had elevated serum ammonia levels or evidence of a metabolic disorder. Conclusion:transient hyperinsulinism can occur in newborns delivered uneventfully without significant perinatal complications. The unusual sensitivity to medical treatment in these cases of neonatal-onset hyperinsulinaemic hypoglycaemia underscores the importance of careful medical management of severe congenital hyperinsulinism. Careful consideration of the indication and if necessary, timing and extent of pancreatectomy is required, while maintaining euglycaemia to protect the developing brain.Abbreviations
AGA
appropriate for gestational age
-
BGL
blood glucose level
-
BWS
Beckwith-Wiedemann syndrome
-
HI
hyperinsulinism
-
HI/HA
hyperinsulinism/hyperammonaemia
-
IUGR
intrauterine growth restriction
-
PHHI
persistent hyperinsulinaemic hypoglycaemia of infancy
-
SGA
small for gestational age
-
SUR
sulphonylurea receptor
-
TNHI
transient neonatal hyperinsulinism
-
UVC
umbilical venous catheter 相似文献
85.
86.
87.
Termorshuizen F Dekker FW van Manen JG Korevaar JC Boeschoten EW Krediet RT;NECOSAD Study Group 《Journal of the American Society of Nephrology : JASN》2004,15(4):1061-1070
A high delivered Kt/V(urea) (dKt/V(urea)) is advocated in the U.S. National Kidney Foundation Dialysis Outcomes Quality Initiative guidelines on hemodialysis (HD) adequacy, irrespective of the presence of residual renal function. The contribution of treatment adequacy and residual renal function to patient survival was investigated. The Netherlands Cooperative Study on the Adequacy of Dialysis is a prospective multicenter study that includes incident ESRD patients older than 18 yr. The longitudinal data on residual renal function and dialysis adequacy of patients who were treated with HD 3 mo after the initiation of dialysis (n = 740) were analyzed. The mean renal Kt/V(urea) (rKt/V(urea)) at 3 mo was 0.7/wk (SD 0.6) and the dKt/V(urea) at 3 mo was 2.7/wk (SD 0.8). Both components of urea clearance were associated with a better survival (for each increase of 1/wk in rKt/V(urea), relative risk of death = 0.44 [P < 0.0001]; dKt/V(urea), relative risk of death = 0.76 [P < 0.01]). However, the effect of dKt/V(urea) on mortality was strongly dependent on the presence of rKt/V(urea), low values for dKt/V(urea) of <2.9/wk being associated with a significantly higher mortality in anuric patients only. Furthermore, an excess of ultrafiltration in relation to interdialytic weight gain was associated with an increase in mortality independent of dKt/V(urea). In conclusion, residual renal clearance seems to be an important predictor of survival in HD patients, and the dKt/V(urea) should be tuned appropriately to the presence of renal function. Further studies are required to substantiate the important role of fluid balance in HD adequacy. 相似文献
88.
A rapid test to monitor alloreactive responses in whole blood using real-time polymerase chain reaction 总被引:1,自引:0,他引:1
Zhou L Toungouz M Donckier V Andrien M Troisi R de Hemptinne B Le Moine A Dupont E Goldman M Stordeur P 《Transplantation》2005,80(3):410-413
Rapid, simple, and reliable assays to monitor allogeneic responses are essential for the safe development of novel protocols of tailored immunosuppression. Herein, we describe a real-time polymerase chain reaction method based on interleukin-2 and interferon-gamma mRNA quantification upon stimulation of whole blood with allogeneic T cell-depleted peripheral blood mononuclear cells. The technique requires only small blood volumes and results can be obtained within 48 hours. Data obtained in a liver transplant patient receiving a tolerance induction protocol based on the infusion of donor-type hematopoietic stem cells suggest that this rapid whole blood mixed lymphocyte reaction assay could be valuable for the monitoring of patients undergoing solid organ or hematopoietic stem cell transplantation. 相似文献
89.
Bergmann C Senderek J Windelen E Küpper F Middeldorf I Schneider F Dornia C Rudnik-Schöneborn S Konrad M Schmitt CP Seeman T Neuhaus TJ Vester U Kirfel J Büttner R Zerres K;APN 《Kidney international》2005,67(3):829-848
BACKGROUND: ARPKD is associated with mutations in the PKHD1 gene on chromosome 6p12. Most cases manifest peri-/neonatally with a high mortality rate in the first month of life while the clinical spectrum of surviving patients is much more variable than generally perceived. METHODS: We examined the clinical course of 164 neonatal survivors (126 unrelated families) over a mean observation period of 6 years (range 0 to 35 years). PKHD1 mutation screening was done by denaturing high-performance liquid chromatography (DHPLC) for the 66 exons encoding the 4074 aa fibrocystin/polyductin protein. RESULTS AND CONCLUSION: This is the first study that reports the long-term outcome of ARPKD patients with defined PKHD1 mutations. The 1- and 10-year survival rates were 85% and 82%, respectively. Chronic renal failure was first detected at a mean age of 4 years. Actuarial renal survival rates [end point defined as start of dialysis/renal transplantation (RTX) or by death due to end-stage renal disease (ESRD)] were 86% at 5 years, 71% at 10 years, and 42% at 20 years. All but six patients (92%) had a kidney length above or on the 97th centile for age. About 75% of the study population developed systemic hypertension. Sequelae of congenital hepatic fibrosis and portal hypertension developed in 44% of patients and were related with age. Positive correlations could further be demonstrated between renal and hepatobiliary-related morbidity suggesting uniform disease progression rather than organ-specific patterns. PKHD1 mutation analysis revealed 193 mutations (70 novel ones; 77% nonconservative missense mutations). No patient carried two truncating mutations corroborating that one missense mutation is indispensable for survival of newborns. We attempted to set up genotype-phenotype correlations and to categorize missense mutations. In 96% of families we identified at least one mutated PKHD1 allele (overall detection rate 76.6%) indicating that PKHD1 mutation screening is a powerful diagnostic tool in patients suspected with ARPKD. 相似文献
90.