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排序方式: 共有896条查询结果,搜索用时 15 毫秒
1.
利用石英弹簧称重法测定了308.15K时乙醇和苯在含端羟基聚丁二烯(HTPB)和端羟基聚丁二烯/丙烯腈共聚物(HTBN)的嵌段共聚聚氨酯膜中的吸收动力学曲线。结合吸收-络合吸附双模式传递模型,研究了聚氨酯膜的微相分离程度、软硬段的比例和组成以及软段分子量等因素对溶剂在膜中溶解和传递性质的影响。 相似文献
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Human TLR-7-, -8-, and -9-mediated induction of IFN-alpha/beta and -lambda Is IRAK-4 dependent and redundant for protective immunity to viruses 总被引:12,自引:0,他引:12
Yang K Puel A Zhang S Eidenschenk C Ku CL Casrouge A Picard C von Bernuth H Senechal B Plancoulaine S Al-Hajjar S Al-Ghonaium A Maródi L Davidson D Speert D Roifman C Garty BZ Ozinsky A Barrat FJ Coffman RL Miller RL Li X Lebon P Rodriguez-Gallego C Chapel H Geissmann F Jouanguy E Casanova JL 《Immunity》2005,23(5):465-478
Five TLRs are thought to play an important role in antiviral immunity, sensing viral products and inducing IFN-alpha/beta and -lambda. Surprisingly, patients with a defect of IRAK-4, a critical kinase downstream from TLRs, are resistant to common viruses. We show here that IFN-alpha/beta and -lambda induction via TLR-7, TLR-8, and TLR-9 was abolished in IRAK-4-deficient blood cells. In contrast, IFN-alpha/beta and -lambda were induced normally by TLR-3 and TLR-4 agonists. Moreover, IFN-beta and -lambda were normally induced by TLR-3 agonists and viruses in IRAK-4-deficient fibroblasts. We further show that IFN-alpha/beta and -lambda production in response to 9 of 11 viruses tested was normal or weakly affected in IRAK-4-deficient blood cells. Thus, IRAK-4-deficient patients may control viral infections by TLR-3- and TLR-4-dependent and/or TLR-independent production of IFNs. The TLR-7-, TLR-8-, and TLR-9-dependent induction of IFN-alpha/beta and -lambda is strictly IRAK-4 dependent and paradoxically redundant for protective immunity to most viruses in humans. 相似文献
4.
Health Care Management Science - Although most hospitals in the United States provide medical services in English, a significant percentage of the U.S. population uses languages other than English.... 相似文献
5.
Muhammad Zain-ul-abdein Furqan Ahmed Iftikhar Ahmed Channa Muhammad Atif Makhdoom Raza Ali Muhammad Ehsan Abdullah Aamir Ehsan Ul Haq Muhammad Nadeem Hafiz Zahid Shafi Muhammad Ali Shar Abdulaziz Alhazaa 《Materials》2022,15(21)
Natural soil (NS)-based geopolymers (GPs) have shown promise as environmentally friendly construction materials. The production of ordinary Portland cement is known to release significant amounts of greenhouse gas (CO2) into the atmosphere. The main objective of this work is to synthesize a geopolymer (GP) from an uncommon aluminosilicate-based NS and a sodium silicate (SS) activating solution that would not only minimize the emission of harmful gases, but also offer improved mechanical strength. Samples of different compositions were produced by varying the wt.% of NS from 50% to 80% and adding a balancing amount of SS solution. The drying and curing of the samples were carried out in an electric oven at specific temperatures. The degree of geopolymerization in the samples was measured by Fourier transform infrared spectroscopy, and microstructural analysis was performed using a scanning electron microscope. Mechanical tests were conducted to evaluate the range of compressive strength values of the prepared GP samples. A minimum compressive strength of 10.93 MPa at a maximum porosity of 37.56% was observed in a sample with an NS to SS ratio of 1:1; while a ratio of 3:1 led to the maximum compressive strength of 26.39 MPa and the minimum porosity of 24.60%. The maximum strength (26.39 MPa) was found to be more than the reported strength values for similar systems. Moreover, an improvement in strength by a factor of three has been observed relative to previously developed NS-based GPs. It may be inferred from the findings that for the given NS, with almost 90% aluminosilicate content, the extent of geopolymerization increases significantly with its increasing proportions, yielding better mechanical strength. 相似文献
6.
Abdulhameed Alfagih Abdulaziz AlJassim Bader Alshamsan Nasser Alqahtani Timothy Asmis 《Current oncology (Toronto, Ont.)》2022,29(10):7148
(1) Background: The management of gastrointestinal stromal tumors (GIST) has significantly evolved over the last two decades, with the introduction of tyrosine kinase inhibitors (TKI). We aim to report 10 years of experience of GIST management at a regional cancer center in Canada. (2) Methods: We retrospectively analyzed the records of 248 consecutive patients diagnosed with GIST between 2011 and 2021. We describe the clinical and pathological data, management, and outcome, including survival. (3) Results: The most common GIST sites were the stomach 63% (156), followed by the small bowel 29% (73). At diagnosis, 83% (206) of patients had localized disease (stage I–III). According to the modified National Institutes of Health consensus criteria (NIH) for GIST, around 45% (90) had intermediate or high-risk disease. Most patients, 86% (213), underwent curative surgical resection. Forty-nine patients received adjuvant imatinib, while forty-three patients had advanced disease and received at least one line of TKI. With a median follow-up of 47 months, the 5-year recurrence-free survival (RFS) rates for very low and low risk were 100% and 94%, respectively, while those for intermediate and high risk were 84% and 51%, respectively. The 5-year overall survival (OS) rates for very low and low risk were 100% and 94%, while intermediate, high risk, and advanced were 91%, 88%, and 65%, respectively. Using the Kaplan–Meier method, there were statistically significant differences in RFS and OS between NIH risk groups, p < 0.0005. In univariate analysis, ECOG, site, mitosis, secondary malignancy, and size were predictors for OS. High mitosis and large size (>5 cm) were associated with worse RFS. (4) Conclusions: Curative surgical resection remains the gold standard management of GIST. Our results are comparable to the reported literature. Further research is needed to explore histology’s role in risk stratification and initiating adjuvant TKI. 相似文献
7.
Hadil A. Alkathiry Samia Q. Alghamdi Holly E.J. Morgan Madeleine E. Noll Jing J. Khoo Abdulaziz N. Alagaili Benjamin L. Makepeace 《Emerging infectious diseases》2023,29(2):402
Scrub typhus is a zoonosis caused by 3 species of Orientia bacteria, including Candidatus Orientia chuto. This species is known only from a human case in Dubai and infections in wildlife in Kenya. We report molecular detection of Candidatus O. chuto in 2 wild rodent species from Saudi Arabia. 相似文献
8.
The development of highly effective conjugate chemistry approaches is a way to improve the quality of drugs and of medicines. The aim of this paper is to highlight and review such hybrid compounds and the strategies underpinning their design. A variety of unique hybrid compounds provide an excellent toolkit for novel biological activity, e.g. anticancer and non-viral gene therapy (NVGT), and as templates for killing bacteria and preventing antibiotic drug resistance. First we discuss the anticancer potential of hybrid compounds, containing daunorubicin, benzyl- or tetrahydroisoquinoline-coumarin, and cytotoxic NSAID-pyrrolizidine/indolizine hybrids, then NVGT cationic lipid-based delivery agents, where steroids or long chain fatty acids as the lipid moiety are bound to polyamines as the cationic moiety. These polyamines can be linear as in spermidine or spermine, or on a polycyclic sugar template, aminoglycosides kanamycin and neomycin B, the latter substituted with six amino groups. They are highly efficient for the delivery of both fluorescent DNA and siRNA. Molecular precedents can be found for the design of hybrid compounds in the natural world, e.g., squalamine, the first representative of a previously unknown class of natural antibiotics of animal origin. These polyamine-bile acid (e.g. cholic acid type) conjugates display many exciting biological activities with the bile acids acting as a lipidic region and spermidine as the polycationic region. Analogues of squalamine can act as vectors in NVGT. Their natural role is as antibiotics. Novel antibacterial materials are urgently needed as recalcitrant bacterial infection is a worldwide problem for human health. Ribosome inhibitors founded upon dimers of tobramycin or neomycin, bound as ethers by a 1,6-hexyl linker or a more complex diether-disulfide linker, improved upon the antibiotic activity of aminoglycoside monomers by 20- to 1200-fold. Other hybrids, linked by click chemistry, conjugated ciprofloxacin to neomycin, trimethoprim, or tedizolid, which is now in clinical trials.Hybrid compounds (L1–L2) possess potential advantages over mixtures used in combination therapies. 相似文献
9.
M. Naiem J. Gerdes Z. Abdulaziz C.A. Sunderland M.J. Allington H. Stein D.Y. Mason 《Journal of immunological methods》1982,50(2):145-160
This paper describes an immunoperoxidase technique for labelling cryostat tissue sections which is routinely used in the authors' laboratories both in the initial screening of hybridoma culture supernatants, and also during the subsequent cloning and growth of antibody-secreting cell lines. The technique can readily be performed on 100 samples in less than 3 h and is free of non-specific background labelling. The staining pattern of a monoclonal antibody on a single tissue section allows semiquantitative assessment of its reactivity against a wide variety of tissue constituents and is thus inherently much more informative than conventional screening techniques (such as binding assays) which yield only a single numerical value for each test performed. In consequence it is often possible to identify the probable specificity of a new monoclonal antibody at the primary screening stage. A further important advantage of immunohistological screening is that it detects antigens on cells or other tissue structures which do not readily enter suspension and also antibodies against nuclear and cytoplasmic antigens.Examples of monoclonal antibodies analysed by immunohistological screening include antibodies against C3b receptor, HLA-DR, factor VIII-related antigen, human syncytiotrophoblast, dendritic reticulum cells and a proliferation-associated cell surface glyco-protein. 相似文献
10.
Khalid Al‐Hezaimi Jafar Naghshbandi Abdulaziz Al‐Rasheed Khalid Merdad James H. Simon Ilan Rotstein 《Dental traumatology》2011,27(5):350-355
Abstract – This experiment assessed the efficacy of the enamel matrix derivative (EMD) to regenerate cementum in vital and endodontically treated teeth with osseous dehiscence defects. Five adult female beagle dogs were used. Thirty maxillary teeth (bilateral maxillary canines and second and fourth premolars) were randomly divided into two experimental groups (groups A and B, containing 12 teeth each) and one control group (group C). Endodontic treatment was only performed on teeth in group A compared with teeth in groups B and C. Buccal osseous dehiscence defects were surgically created in teeth from all groups. Teeth in the experimental group were treated with the EMD, whereas the controls were not. After 5 months, the animals were sacrificed and block sections of the teeth in experimental and control groups were processed for histological analysis. Newly regenerated cementum was observed in all teeth in groups A and B. No cementum regeneration was observed in group C. There was a significant difference in cementum generation between the experimental and control groups (P < 0.001). EMD therapy induces cementogenesis in vital and endodontically treated teeth with osseous dehiscence defects. 相似文献