全文获取类型
收费全文 | 724篇 |
免费 | 35篇 |
国内免费 | 26篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 48篇 |
妇产科学 | 9篇 |
基础医学 | 40篇 |
口腔科学 | 28篇 |
临床医学 | 70篇 |
内科学 | 138篇 |
皮肤病学 | 4篇 |
神经病学 | 17篇 |
特种医学 | 121篇 |
外科学 | 181篇 |
综合类 | 9篇 |
预防医学 | 17篇 |
眼科学 | 5篇 |
药学 | 73篇 |
肿瘤学 | 24篇 |
出版年
2022年 | 3篇 |
2021年 | 6篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2018年 | 6篇 |
2017年 | 5篇 |
2016年 | 4篇 |
2015年 | 7篇 |
2014年 | 8篇 |
2013年 | 15篇 |
2012年 | 20篇 |
2011年 | 11篇 |
2010年 | 13篇 |
2009年 | 21篇 |
2008年 | 29篇 |
2007年 | 38篇 |
2006年 | 22篇 |
2005年 | 18篇 |
2004年 | 20篇 |
2003年 | 23篇 |
2002年 | 16篇 |
2001年 | 24篇 |
2000年 | 17篇 |
1999年 | 14篇 |
1998年 | 41篇 |
1997年 | 45篇 |
1996年 | 52篇 |
1995年 | 39篇 |
1994年 | 31篇 |
1993年 | 30篇 |
1992年 | 18篇 |
1991年 | 18篇 |
1990年 | 12篇 |
1989年 | 24篇 |
1988年 | 27篇 |
1987年 | 16篇 |
1986年 | 12篇 |
1985年 | 13篇 |
1984年 | 11篇 |
1983年 | 7篇 |
1982年 | 7篇 |
1981年 | 5篇 |
1980年 | 5篇 |
1979年 | 4篇 |
1978年 | 2篇 |
1977年 | 6篇 |
1976年 | 6篇 |
1975年 | 8篇 |
1954年 | 1篇 |
排序方式: 共有785条查询结果,搜索用时 15 毫秒
21.
D McWhirter M den Dulk M Terlizzo HZ Malik SW Fenwick GJ Poston 《Annals of the Royal College of Surgeons of England》2013,95(8):e136-e138
A 74-year old man underwent a radical cholecystectomy for presumed gallbladder cancer. The histology of the resected specimen in fact revealed the lesion to be metastatic renal cell carcinoma from his resected right nephrectomy performed 14 years previously. 相似文献
22.
23.
Gyuranecz M Dénes B Hornok S Kovács P Horváth G Jurkovich V Varga T Hajtós I Szabó R Magyar T Vass N Hofmann-Lehmann R Erdélyi K Bhide M Dán A 《Vector borne and zoonotic diseases (Larchmont, N.Y.)》2012,12(8):650-653
Abstract Q fever is an important zoonotic disease caused by Coxiella burnetii. There are few reliable data about C. burnetii infection available. The aim of this study was to assess the importance and potential infectious sources of Q fever in Hungary. A total of 215 milk samples (10 individual samples from each herd and 1 bulk tank milk sample from each cattle herd), and 400 serum samples (20 from each herd) were tested from 15 dairy cattle herds and 5 sheep flocks located in different parts of Hungary. The study found 19.3% (58/300) and 38.0% (57/150) seropositivity in cattle, and 0% (0/100) and 6.0% (3/50) seropositivity in sheep, by complement fixation test (CFT) and enzyme-linked immunosorbent assay (ELISA), respectively. C. burnetii DNA was detected by IS1111 element-based TaqMan real-time polymerase chain reaction (PCR) in 8.7% (13/150) of individual dairy cow milk samples, 4.0% (2/50) of individual sheep milk samples, and 66.7% (10/15) of dairy bulk tank milk samples. Samples taken from nine different commercially-available pasteurized cow milk products from different Hungarian producers were also tested for the presence of C. burnetii DNA, and eight of these samples were found to be positive (88.9%). The real-time PCR examination of 5402 ixodid ticks collected from different parts of the country yielded negative results. Knowledge of the true prevalence of Q fever is crucial for policymakers involved in evidence-based decision making. 相似文献
24.
Hydroxyurea-induced augmentation of fetal hemoglobin production in patients with sickle cell anemia 总被引:3,自引:4,他引:3
Five patients with sickle cell anemia were treated with hydroxyurea (HU), in hopes of augmenting their production of fetal hemoglobin. Laboratory responses in two patients treated for more than 2 years were encouraging and there were suggestions of clinical improvement. Long- term HU therapy should be considered for severely affected adults with sickle cell anemia who are willing to accept what is probably a small risk of carcinogenesis. Preliminary chromosomal analysis and knowledge of the clastogenic properties of HU suggest that conception and pregnancy should be avoided. Pharmacokinetic studies will probably be necessary to adjust individual dosage schedules so that cytotoxicity is avoided. F cell responses can be seen in 2 to 3 weeks if the HU dose is optimal, but establishment of a large number of F cells in the circulation may take a month or longer. 相似文献
25.
Cardoso AA; Schultze JL; Boussiotis VA; Freeman GJ; Seamon MJ; Laszlo S; Billet A; Sallan SE; Gribben JG; Nadler LM 《Blood》1996,88(1):41-48
Even if neoplastic cells express tumor associated antigens they still may fail to function as antigen presenting cells (APC) if they lack expression of one or more molecules critical for the induction of productive immunity. These cellular defects can be repaired by physiologic activation, transfection, or fusion of tumor cells with professional APC. Although such defects can be repaired, antitumor specific T cells may still fail to respond in vivo if they may have been tolerized. Here, human pre-B cell acute lymphoblastic leukemia (pre-B ALL) was used as a model to determine if primary human tumor cells can function as alloantigen presenting cells (alloAPC) or alternatively whether they induce anergy. In the present report, we show that pre-B cell ALL express alloantigen and adhesion molecules but uniformly lack B7-1 (CD80) and only a subset express B7-2 (CD86). Pre-B ALL cells are inefficient or ineffective alloAPC and those cases that lack expression of B7-1 and B7-2 also induce alloantigen specific T- cell unresponsiveness. Under these circumstances, T-cell unresponsiveness could be prevented by physiologic activation of tumor cells via CD40, cross-linking CD28, or signaling through the common gamma chain of the interleukin-2 receptor on T cells. Taken together, these results suggest that pre-B ALL may be incapable of inducing clinically significant T-cell-mediated antileukemia responses. This defect may be not only due to their inability to function as APC, but also due to their potential to induce tolerance. Attempts to induce clinically significant antitumor immune responses may then require not only mechanisms to repair the antigen presenting capacity of the tumor cells, but also reversal of tolerance. 相似文献
26.
Quality control of multidrug resistance assays in adult acute leukemia: correlation between assays for P-glycoprotein expression and activity 总被引:1,自引:5,他引:1
Broxterman HJ; Sonneveld P; Feller N; Ossenkoppele GJ; Wahrer DC; Eekman CA; Schoester M; Lankelma J; Pinedo HM; Lowenberg B; Schuurhuis GJ 《Blood》1996,87(11):4809-4816
We have compared multiple assays for the P-glycoprotein (Pgp/MDR1) phenotype in fresh and thawed adult acute leukemia to validate and quantitate measures for the expression and function of Pgp. The results are related to the Pgp-expressing KB8 and KB8-5 call lines. The most sensitive assay was the measurement of modulation of the rhodamine 123 (R123) fluorescence by 2 micromol/L PSC833, followed by the modulation of the probe calcein-AM. We also found a good intralaboratory and interlaboratory correlation between the values of the R123/PSC833 assay for fresh as well as thawed samples. In addition, the affects of PSC833 on 3H-daunorubicin (DNR) accumulation, DNR fluorescence, and 3H- vincristine accumulation were very similar. The correlation between the DNR/PSC833 and R123/PSC833 test was r = .86 (N = 51). The modulation of drug accumulation by 8 micromol/L verapamil was the some as the PSC833 effect for DNR (117%, N = 21), but was higher for vincristine in every single case (161% v 121%, N = 22; P< .001), indicating additional verapamil effects, not related to Pgp. The correlation of the staining of viable cells for Pgp with the monoclonal antibody MRK16 was r = .77 (N = 52) for the R123/PSC833 functional test and r = .84 (N = 50) for the DNR/PSC833 test. From these results it could be calculated that a maximal increase of the mean DNR accumulation of about 50% can be achieved by blocking Pgp pump activity with PSC833 in leukemic blast samples with the highest mean Pgp expression. Subpopulations of blast calls with higher Pgp activity are likely to be present. Their relevance has to be studied further. The methods outlined here allow the reliable, quantitative monitoring of the Pgp/MDR1 phenotype in leukemias in multicentered, clinical Pgp modulation studies. 相似文献
27.
Noble ML Vaezy S Keshavarzi A Paun M Prokop AF Chi EY Cornejo C Sharar SR Jurkovich GJ Martin RW Crum LA 《The Journal of trauma》2002,53(6):1115-1120
BACKGROUND: Previous studies have shown that high-intensity focused ultrasound (HIFU) can effectively control bleeding of incised livers and spleens and punctured vessels. This current study investigated the long-term safety of HIFU in splenic hemostasis. METHODS: A total of 21 rabbits were randomly assigned to two groups: HIFU treatment (n = 14), and sham treatment (n = 7). All animals underwent sterile laparotomy and splenic exposure. The HIFU-treated animals received splenic incisions, 8 to 10 mm long and 4 to 5 mm deep, and immediate 9.6-MHz HIFU until hemostasis was achieved. After recovery, ultrasound images, blood samples, and histologic samples were collected on days 0, 1, 3, 7, 14, 28, and 60. RESULTS: All 14 splenic injuries were hemostatic after an average of 96 seconds of HIFU application. There was evidence of rebleeding in one animal between days 3 and 7 posttreatment. Subsequent blood analysis showed no significant difference in serial hematologic or coagulation measures between HIFU and sham groups. Histologic examination up to 60 days posttreatment revealed scarring and spleen tissue regeneration at the treatment site. CONCLUSION: HIFU provides an effective and safe method of achieving hemostasis after acute splenic injury. 相似文献
28.
Zatzick DF Jurkovich GJ Gentilello L Wisner D Rivara FP 《Archives of surgery (Chicago, Ill. : 1960)》2002,137(2):200-205
HYPOTHESIS: Patients undergoing trauma surgery for injury who have subsequent posttraumatic stress disorder (PTSD) or problem drinking will demonstrate significant impairments in functional outcomes compared with patients without these disorders. DESIGN: Prospective cohort study. SETTING: Level I academic trauma center. PARTICIPANTS: One hundred one randomly selected survivors of intentional and unintentional injuries were interviewed while hospitalized and again 1 year later. The investigation achieved a 73% 1-year follow-up rate. MAIN OUTCOME MEASURES: Posttraumatic stress disorder was assessed with the Post-traumatic Stress Disorder Checklist and problem drinking was assessed with the Alcohol Use Disorder Identification Test. Functional status was assessed with the Medical Outcomes Study 36-Item Short-Form Health Survey. RESULTS: One year after injury, 30% of patients (n = 22) met symptomatic criteria for PTSD and 25% (n = 18) had Alcohol Use Disorder Identification Test scores indicative of problem drinking. Patients with PTSD demonstrated significant adverse outcomes in 7 of the 8 domains of the Medical Outcomes Study 36-Item Short-Form Health Survey compared with patients without PTSD. In multivariate models that adjusted for injury severity, chronic medical conditions, age, sex, preinjury physical function, and alcohol use, PTSD remained the strongest predictor of an adverse outcome. Patients with problem drinking did not demonstrate clinically or statistically significant functional impairment compared with patients without problem drinking. CONCLUSIONS: Posttraumatic stress disorder persisted in 30% of patients 1 year after traumatic injury and was independently associated with a broad profile of functional impairment. The development of treatment intervention protocols for trauma patients with PTSD is warranted. 相似文献
29.
G Low GJ Irwin G Haddock SV Maroo 《Journal of Medical Imaging and Radiation Oncology》2006,50(3):249-251
The Currarino triad is a complex anomaly consisting of an anorectal malformation, a sacral bone defect and a presacral mass. It was first described in 1981 and since then, approximately 250 cases have been reported. Radiology has an important part to play in the diagnosis of this entity, as the imaging features are characteristic. We report a case of Currarino triad in an infant who presented with intractable constipation and discuss relevant MRI and plain radiography findings. 相似文献
30.
BACKGROUND: The cost of uncompensated trauma care is a significant barrier to trauma system development. Trauma center designation may burden an institution with an unprofitable mix of underinsured, severely injured patients. Concerns about inadequate reimbursement may motivate interhospital transfers on the basis of insurance status rather than medical necessity, potentially undermining the effectiveness of the system. We set out to explore whether this phenomenon exists in a mature trauma system. METHODS: Trauma patients receiving definitive care at Level III or IV trauma centers were compared with patients transferred from these centers to the only Level I regional center. Insurance status was classified as either commercial or noncommercial. Logistic regression was used to determine the independent predictors of transfer after adjusting for differences in injury severity. RESULTS: Only 12% of 2,008 patients initially evaluated at Level III/IV centers were transferred to the Level I center, an indicator of the effectiveness of prehospital triage protocols in the region. The presence of specific complex injuries, younger age, male gender, and insurance status were all associated with an increased likelihood of transfer. Insurance status was an independent predictor of transfer: patients without commercial insurance were 2.4 (95% confidence interval, 1.6-3.6) times more likely to be transferred to a Level I facility than patients with commercial insurance after adjusting for differences in injury severity. CONCLUSION: Insurance status influences the decision to transfer to higher levels of care. These findings suggest that the financial burden of a trauma system may be inequitably distributed. This inequitable distribution may be necessary for trauma system sustainability and calls for the development of disproportionate reimbursement strategies to support regional referral centers. 相似文献