全文获取类型
收费全文 | 8139篇 |
免费 | 364篇 |
国内免费 | 25篇 |
专业分类
耳鼻咽喉 | 159篇 |
儿科学 | 176篇 |
妇产科学 | 315篇 |
基础医学 | 1626篇 |
口腔科学 | 181篇 |
临床医学 | 604篇 |
内科学 | 1433篇 |
皮肤病学 | 157篇 |
神经病学 | 619篇 |
特种医学 | 390篇 |
外国民族医学 | 1篇 |
外科学 | 1525篇 |
综合类 | 130篇 |
一般理论 | 2篇 |
预防医学 | 238篇 |
眼科学 | 207篇 |
药学 | 382篇 |
中国医学 | 8篇 |
肿瘤学 | 375篇 |
出版年
2022年 | 42篇 |
2021年 | 101篇 |
2020年 | 50篇 |
2019年 | 100篇 |
2018年 | 109篇 |
2017年 | 105篇 |
2016年 | 132篇 |
2015年 | 157篇 |
2014年 | 177篇 |
2013年 | 247篇 |
2012年 | 386篇 |
2011年 | 418篇 |
2010年 | 251篇 |
2009年 | 245篇 |
2008年 | 419篇 |
2007年 | 414篇 |
2006年 | 392篇 |
2005年 | 448篇 |
2004年 | 414篇 |
2003年 | 404篇 |
2002年 | 381篇 |
2001年 | 187篇 |
2000年 | 145篇 |
1999年 | 145篇 |
1998年 | 77篇 |
1997年 | 79篇 |
1996年 | 73篇 |
1995年 | 58篇 |
1994年 | 53篇 |
1993年 | 37篇 |
1992年 | 51篇 |
1991年 | 79篇 |
1990年 | 56篇 |
1989年 | 52篇 |
1988年 | 65篇 |
1987年 | 53篇 |
1986年 | 51篇 |
1985年 | 49篇 |
1984年 | 36篇 |
1982年 | 44篇 |
1979年 | 36篇 |
1977年 | 38篇 |
1976年 | 39篇 |
1975年 | 44篇 |
1974年 | 52篇 |
1973年 | 50篇 |
1939年 | 36篇 |
1937年 | 38篇 |
1931年 | 38篇 |
1926年 | 38篇 |
排序方式: 共有8528条查询结果,搜索用时 15 毫秒
81.
Functional deficits are important factors influencing treatment tolerability and prognosis in elderly cancer patients. Measurement and quantification of these deficits are essential for successful planning and sustaining therapy. Comprehensive geriatric assessment (CGA) offers a systematic approach to assess and classify individual deficits. Due to the broad range of patient capabilities, types of neoplasm and treatment strategies it is important to make a sensible choice of instruments to obtain relevant information. Performing CGA successfully in daily practice is efficient and feasible. 相似文献
82.
83.
Immunosuppression and the Risk of Post-Transplant Malignancy Among Cadaveric First Kidney Transplant Recipients 总被引:4,自引:0,他引:4
Rami T. Bustami Akinlolu O. Ojo Robert A. Wolfe Robert M. Merion William M. Bennett Suzanne V. McDiarmid Alan B. Leichtman Philip J. Held Friedrich K. Port 《American journal of transplantation》2004,4(1):87-93
The success of renal transplantation may be counterbalanced by serious adverse medical events. The effect of immunosuppression on the incidence of de novo neoplasms among kidney recipients should be monitored continuously. Using data from the Scientific Registry of Transplant Recipients, we studied the association of induction therapy by immunosuppression with antilymphocyte antibodies, with the development of de novo neoplasms. The study population included more than 41 000 recipients who received a cadaveric first kidney transplant after December 31, 1995, and were followed through February 28, 2002. Using Cox regression models, we estimated time to development of two types of malignancy: de novo solid tumors and post-transplant lymphoproliferative disorder (PTLD). We made adjustments for several patient demographic factors and comorbidities. Induction therapy was significantly associated with a higher relative risk (RR) of PTLD (RR = 1.78, p < 0.001), but not with a greater likelihood of de novo tumors (RR = 1.07, p = 0.42). Treatment with maintenance tacrolimus vs. cyclosporine showed a significantly different RR of developing de novo tumors for recipients with induction than for those not receiving induction (p = 0.024). These new estimates of the magnitude of malignancy risk associated with induction therapy may be useful for clinical practice. 相似文献
84.
Sullivan SR Friedrich JB Engrav LH Round KA Heimbach DM Heckbert SR Carrougher GJ Lezotte DC Wiechman SA Honari S Klein MB Gibran NS 《Burns : journal of the International Society for Burn Injuries》2004,30(6):583-590
Recent studies have shown that burn patients receive larger volumes of fluids than predicted by the Baxter formula and the reason for this is unclear. One potential reason is that increased analgesics are used which could blunt the response to fluid resuscitation. The purpose of this study was to compare the administration of opioid agonists in patients treated at a single burn center in the 1970s and in the year 2000. We performed a retrospective chart review comparing two matched cohorts. Group I consisted of 11 patients admitted between 1975 and 1978. Group II consisted of 11 patients admitted in 2000 matched for age, sex and %TBSA. Patients in Group II received a significantly higher mean opioid equivalent than those in Group I (26.5 +/- 12.3 versus 3.9 +/- 2.2 in the first 24h, P < 0.001). In addition, in Group II, a larger variety and combination of opioid agonists were used. This review demonstrates a significant increase from the 1970s to 2000 in the type, dose prescribed and dose delivered of opioid agonists. Along with "fluid creep", we have also increased our use of opioid agonists or "opioid creep". Higher doses of opioid agonists may have hemodynamic consequences, which may contribute to the increased fluid volumes. 相似文献
85.
Nitric oxide synthase in acute alteration of nitric oxide levels after subarachnoid hemorrhage 总被引:5,自引:0,他引:5
Sehba FA Chereshnev I Maayani S Friedrich V Bederson JB 《Neurosurgery》2004,55(3):671-7; discussion 677-8
OBJECTIVE: Subarachnoid hemorrhage (SAH) is associated with acute decreases and subsequent recovery of cerebral nitric oxide (NO) levels, but the mechanisms of these alterations are not known. In this study, we measured NO synthase (NOS) protein and kinetics to determine its involvement in the alterations of cerebral NO levels after SAH. METHODS: The endovascular rat model of SAH was used. The number of NOS-1 (neuronal) and NOS-2 (inducible)-positive cells (0-96 h) was determined by counting immunoreactive cells in 8-microm cryostat sections. The tissue content of active NOS and its kinetic parameters were studied with an enzymatic l-citrulline assay. RESULTS: The number of NOS-1-positive cells increased between 1 and 3 hours after SAH, decreased to and below control values at 6 and 72 hours after SAH, and increased to control values 96 hours after SAH. The number of NOS-2-positive cells increased 1 hour after SAH, decreased to control values at 24 hours, and increased above control values 96 hours after SAH. The Michaelis-Menten kinetic parameters (V(max), K(m), slope) of NOS remained unchanged at 10 and 90 minutes after SAH. CONCLUSION: NOS-1 and -2 proteins undergo a triphasic alteration after SAH, whereas the amount of active NOS and its kinetic parameters remain unchanged during the first 90 minutes after SAH. Depletion of NOS is not involved in the acute alterations of cerebral NO levels after SAH. 相似文献
86.
87.
Schukfeh N Metzelder ML Petersen C Reismann M Pfister ED Ure BM Kuebler JF 《Journal of pediatric surgery》2012,47(3):501-505
Background/PurposeThe surgical treatment for patients with progressive familial intrahepatic cholestasis (PFIC) is either liver transplantation (LTX) or partial external biliary diversion (PEBD). Both procedures achieve a good short-term outcome. However, the treatment strategy for these children remains controversial because the long-term outcome after PEBD is unknown. The aim of our study was to assess the long-term outcome and complications after PEBD in our institution.MethodsWe retrospectively analyzed the characteristics of all patients with PFIC undergoing PEBD in our department from 1994 to 2008. The course of serum bile acids, pruritus, and liver enzymes was assessed in a regular follow-up.ResultsTwenty-four patients underwent PEBD. Thirteen patients (54%) improved significantly, with a normalization of serum bile acids (P < .001 vs postoperatively) and lessened pruritus (P < .05 vs preoperatively) at 12 months after PEBD. None of these patients showed progression of cholestasis during a median follow-up of 9.8 years (range, 1.6-14.3 years). Partial external biliary diversion failed to normalize bile acids in 11 patients, of whom 9 required secondary LTX at a 1-year follow-up, with a median interval of 1.9 years (range, 0.5-3.8 years). All 7 patients (100%) with liver cirrhosis at the time of PEBD and 2 of 17 patients without cirrhosis (12%) required secondary LTX (P < .001).ConclusionsClinical improvement with normalization of serum bile acids within 1 year was associated with an excellent long-term outcome in patients with PEBD. The presence of liver cirrhosis at the time of PEBD indicated an unfavorable outcome. Thus, we recommend primary LTX only in PFIC patients with liver cirrhosis. 相似文献
88.
Background
The purpose of this paper is to compare a group of patients with upper extremity amputation injuries who presented to a tertiary referral center without having been previously seen at another hospital versus a group of patients who was transferred from another facility. We hypothesize that transferred patients will generally undergo more complex treatments, that some transferred patients will be treated in the ER with simple treatments (thereby perhaps not requiring transfer), and that transferred patients will be less likely to have insurance coverage.Methods
All patients who presented to our ER from January 1, 2007 to December 31, 2008 with the classification of hand and finger amputation were included. Data collected included whether or not the patient was transferred from another institution, age, mechanism of injury, partial versus total amputation, location treated, transportation method, general treatment classification, type of insurance, and month of presentation.Results
No statistical difference was found between patients who were transferred versus those who were not with respect to age, sex, mechanism, whether the amputation was partial versus complete, or insurance coverage. Statistical differences were noted between the subset of patients who was transferred versus those who were not with respect to treatment location, method of transportation, and treatment.Conclusions
Patients transferred to our institution required significantly more complex treatments and were significantly more likely to be treated in the operating room. A small but significant group of patients was treated in the ER or required relatively simple treatments after transfer. Our hypothesis that a higher percentage of patients transferred to our institution would have less insurance coverage was not supported by the data. Tertiary centers can expect to continue receiving a steady stream of amputation referrals. 相似文献89.
90.
Franz F Immer Urs Hagen Pascal A Berdat Friedrich S Eckstein Thierry P Carrel 《European journal of cardio-thoracic surgery》2005,27(4):654-657
OBJECTIVES: Prompt diagnosis of subsequent dilatation of the dissected aorta is crucial to reduce late mortality in these patients. This study focuses on risk factors for dilatation of the aorta after type A aortic dissection (AADA) affecting a normal-sized or slightly dilated aorta. METHODS: Overall 531 CT scans were analysed. Patients were included in the study if at least 3 CT scans were available after operative repair. 64 patients (59.8%) out of 107 patients full-field the inclusion criteria. Volumetric analyses of the aorta were performed. Patients were divided in 3 groups: group A included 26 patients (40.6%) without progression of the aortic diameter, group 2, 27 patients (42.2%) with slight progression and group 3, 11 patients (17.2%) with important progression, requiring surgery in 9 patients (81.8%). Risk-factors for progression of the aortic size were analysed and compared between the groups. RESULTS: Patients from group 3 were younger 57.7+/-13.4 vs. 61.9+/-11.6 in group 1 (P<0.05) and were more frequent female (45.4 vs. 23.1%; P<0.05). Dissection of the supraaortic branches (100 vs. 80.8%; P<0.05), the presence of preoperative cerebral, visceral or peripheral malperfusion (54.6 vs. 26.9%; P<0.05) and contrast enhancement in the false lumen during the follow-up (72.7 vs. 57.7%; P=0.07) were additional risk factors for late aortic dilatation in these patients. CONCLUSIONS: Acute type A aortic dissection in younger patients, involving the supraaortic branches and/or combined with malperfusion syndrome favour secondary dilatation. A close follow-up is mandatory to prevent acute complications of the diseased downstream aorta following repair of a AADA. 相似文献