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目的 评价不同增溶技术对西罗莫司(sirolimus,SRL)的体外溶出与体内吸收的影响。方法 选取固体分散体(SD)、包合物(IC)、自微乳(SMEDDS)和纳米结构脂质载体(NLC)为SRL的增溶技术。SRL-SMEDDS和SRL-NLC已在前期研究中获得最优处方。另外,以包封率、体外溶出度等为指标,筛选SRL-SD和SRL-IC的处方工艺。分别采用0.4% SDS,水,及pH 1.2、pH 4.5、pH 6.8、pH 7.4缓冲液为溶出介质,考察市售制剂Rapamune®,以及自制的各增溶制剂的溶出曲线。采用比格犬体内药动学试验,考察上述制剂的体内吸收度。结果 在0.4% 十二烷基硫酸钠(SDS)中,各制剂在2 h的溶出度均超过80%。在pH 1.2的介质中,无法测得SRL-SD的溶出度,而IC、SMEDDS和NLC的溶出度呈先增大后减小的趋势。在其他介质中,SRL的溶出度均有所降低,而SRL-IC显示了最佳的溶出度,未出现明显的降低趋势。体内药动学试验结果显示,原料药、SRL-SD、SRL-IC、SRL-NLC和SRL-SMEDDS的相对生物利用度分别为9.1%、18.7%、33.2%、78.0%、97.6%。结论 SD、SMEDDS、NLC、IC均可提高SRL的体外溶出度和体内吸收度,其中,SMEDDS对SRL的生物利用度改善最为明显。  相似文献   
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BackgroundPlexiform neurofibromas (PNs) are benign peripheral nerve sheath tumors that arise in one-third of individuals with neurofibromatosis type 1 (NF1). They may cause significant disfigurement, compression of vital structures, neurologic dysfunction, and/or pain. Currently, the only effective management strategy is surgical resection. Converging evidence has demonstrated that the NF1 tumor suppressor protein, neurofibromin, negatively regulates activity in the mammalian Target of Rapamycin pathway.MethodsWe employed a 2-strata clinical trial design. Stratum 1 included subjects with inoperable, NF1-associated progressive PN and sought to determine whether sirolimus safely and tolerably increases time to progression (TTP). Volumetric MRI analysis conducted at regular intervals was used to determine TTP relative to baseline imaging.ResultsThe estimated median TTP of subjects receiving sirolimus was 15.4 months (95% CI:14.3–23.7 mo), which was significantly longer than 11.9 months (P < .001), the median TTP of the placebo arm of a previous PN clinical trial with similar eligibility criteria.ConclusionsThis study demonstrated that sirolimus prolongs TTP by almost 4 months in patients with NF1-associated progressive PN. Although the improvement in TTP is modest, given the lack of significant or frequent toxicity and the availability of few other treatment options, the use of sirolimus to slow the growth of progressive PN could be considered in select patients.  相似文献   
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In recurrent hepatitis C (HCV) post‐liver transplantation (OLT), the combination of immunosuppressants and HCV is postulated to increase hepatocyte apoptosis and liver fibrosis. We evaluated hepatocyte apoptosis within the liver tissue of patients with postOLT HCV recurrence compared to HCV‐negative individuals and correlated these findings with the effects of immunosuppressants on HCV‐induced cell death and its inhibition in primary mouse hepatocytes (PMoH). Liver biopsies from patients with and without HCV were evaluated by immunohistochemistry for markers of apoptosis M30 CytoDEATH (M30) and cleaved PARP (clPARP). PMoH from C57BL/6 mice were infected with recombinant adenoviruses (rAdHCV) that expressed HCV proteins in hepatocytes. Infected cells were treated with cyclosporine, tacrolimus, sirolimus and/or MMF with or without pan‐caspase inhibitor Q‐VD‐Oph. Cell viability and apoptosis were evaluated using crystal violet assays and Western immunoblots probed for cleaved caspase‐3 (clCas3) and clPARP. Both M30 and clPARP were increased in the liver biopsies of patients with postOLT HCV recurrence compared to HCV‐negative individuals. Treatment of rAdHCV‐infected PMoH with cyclosporine, tacrolimus or sirolimus reduced cell viability and increased clCas3 and clPARP compared to rAdHCV infection alone. Addition of MMF to cyclosporine, tacrolimus or sirolimus further reduced cell viability and increased clCas3 and clPARP. Q‐VD‐Oph improved cell viability in HCV‐infected PMoH treated with immunosuppressants alone and in combination and reduced clCas3 and clPARP by approximately 90%. Immunosuppressive agents, especially in combination, enhanced apoptosis in HCV‐infected hepatocytes. The finding that Q‐VD‐Oph reversed hepatocyte death suggests that treatments utilizing apoptosis inhibition might reduce liver injury in postOLT HCV recurrence.  相似文献   
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The current standard of care for patients with Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL) is high-dose conditioning followed by autologous stem cell transplantation (ASCT). For some patients (ie, those with highest-risk disease, insufficient stem cell numbers after mobilization, or bone marrow involvement) allogeneic hematopoietic cell transplantation (alloHCT) offers the potential for cure. However, the majority of patients undergoing alloHCT receive reduced-intensity conditioning as a preparative regimen, and studies assessing outcomes of patients after alloHCT with myeloablative conditioning are limited. In this retrospective study, we reviewed outcomes of 22 patients with recurrent and refractory NHL who underwent alloHCT with myeloablative BEAM conditioning and received tacrolimus/sirolimus as graft-versus-host disease (GVHD) prophylaxis at City of Hope between 2005 and 2018. With a median follow-up of 2.6 years (range, 1.0 to 11.2 years), the probabilities of 2-year overall survival and event-free survival were 58.3% (95% confidence interval [CI], 35.0% to 75.8%) and 45.5% (95% CI, 24.4% to 64.3%), respectively. The cumulative incidence of grade II to IV acute GVHD was 45.5% (95% CI, 23.8% to 64.9%), with only 1 patient developing grade IV acute GVHD. However, chronic GVHD was seen in 55% of the patients (n?=?12). Of the 22 eligible patients, 2 had undergone previous ASCT and 2 had undergone previous alloHCT. Both patients with previous ASCT developed severe regimen-related toxicity. Patients who underwent alloHCT with chemorefractory disease had lower survival rates, with 1-year OS and EFS of 44.4% and 33.0%, respectively. In conclusion, alloHCT with a BEAM preparative regimen and tacrolimus/sirolimus-based GVHD should be considered as an alternative option for patients with highest-risk lymphoma whose outcomes are expectedly poor after ASCT.  相似文献   
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Drug-eluting bioresorbable scaffolds represent the last frontier in the field of angioplasty and stenting to treat coronary artery disease, one of the leading causes of morbidity and mortality worldwide. In particular, sirolimus-eluting magnesium-based scaffolds were recently introduced in clinical practice. Magnesium alloys are biocompatible and dissolve in body fluids, thus determining high concentrations of magnesium in the local microenvironment. Since magnesium regulates cell growth, we asked whether high levels of magnesium might interfere with the antiproliferative action of sirolimus. We performed in vitro experiments on rabbit coronary artery endothelial and smooth muscle cells (rCAEC and rSMC, respectively). The cells were treated with sirolimus in the presence of different concentrations of extracellular magnesium. Sirolimus inhibits rCAEC proliferation only in physiological concentrations of magnesium, while high concentrations prevent this effect. On the contrary, high extracellular magnesium does not rescue rSMC growth arrest by sirolimus and accentuates the inhibitory effect of the drug on cell migration. Importantly, sirolimus and magnesium do not impair rSMC response to nitric oxide. If translated into a clinical setting, these results suggest that, in the presence of sirolimus, local increases of magnesium concentration maintain normal endothelial proliferative capacity and function without affecting rSMC growth inhibition and response to vasodilators.  相似文献   
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Epstein–Barr virus–associated smooth‐muscle tumors (EBV‐SMTs) are unique and rare neoplasms described in immunocompromised patients. The case describes a nine‐year‐old female with a history of acute lymphoblastic leukemia with relapse and subsequent allogeneic bone marrow transplantation who presented with multiple EBV‐SMTs of the liver. EBV utilizes the mammalian target of rapamycin (mTOR) pathway for tumor growth, and sirolimus, a mTOR inhibitor, has shown to result in a short‐term response. We now report an extended treatment response with sirolimus in a pediatric patient with an EBV‐SMT.  相似文献   
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Background

Soluble CD30 (sCD30) is a suggested marker for kidney transplantation outcomes. We investigated whether sCD30 serum levels are influenced by immunosuppression and whether they correlate with findings in protocol biopsies and with CD30 gene expression in peripheral blood mononuclear cells (PBMC).

Methods

We studied 118 kidney transplant recipients that initially received tacrolimus (TAC) and, at month-3, were converted or not to sirolimus (SRL).

Results

sCD30 serum levels gradually declined after transplantation, being the decline more pronounced in the SRL group. CD30 gene expression in PBMC was higher in the SRL group than in the TAC group. Patients with IF/TA?≥?I in the month-24 protocol biopsy had higher sCD30 levels than patients without IF/TA, in the SRL group (P?=?.03) and in the TAC group (P?=?.07). CD30+ cells were observed in three out of 10 biopsies with inflammatory infiltrate from the SRL group. In mixed lymphocyte cultures, SRL and TAC diminished the number of CD30+ T cells and the sCD30 levels in the supernatant, but the effect of SRL was stronger.

Conclusions

Overall, sCD30 levels are lower in SRL-treated patients, but the association between increased sCD30 levels and IF/TA at month-24 post-transplantation is stronger in SRL than in TAC-treated patients.  相似文献   
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