945 resultados para cytotoxic T lymphocyte antigen 4
Resumo:
The mineral svanbergite SrAl 3(PO 4,SO 4) 2(OH) 6 is a hydroxy phosphate-sulphate mineral belonging to the beudantite subgroup of alunites and has been characterised by vibrational spectroscopy. Bands at various wavenumbers were assigned to the different vibrational modes of svanbergite, which were then associated with the structure of the mineral. Bands were primarily assigned to phosphate and sulphate stretching and bending modes. Two symmetric stretching modes for both phosphate and sulphate supported the concept of non-equivalent phosphate and sulphate units in the mineral structure. Bands in the OH stretching region enabled hydrogen bond distances to be calculated. Comparison of the hydrogen bond distances and the calculated hydrogen bond distances from the structure models indicates that hydrogen bonding in svanbergite occurs between the two OH units rather than OH to SO42- units.
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The rate of singlet-to-triplet intersystem crossing in 1,4-didehydrobenzene (the biradical produced as a reactive intermediate in the thermal cycloaromatization of enediynes), cannot be increased by the application of an external magnetic field. The rate of product formation and the distribution of stable products of 2,3-di-n-propyl-1,4-didehydrobenzene thermolysis is unchanged at magnetic flux densities in the range 0–2000 G and at 66 000 G. Similarly, the rate of thermolysis of an unsymmetrical enediyne is insensitive to magnetic field flux in the same range. This finding precludes the modulation of enediyne reaction rates in pharmaceutical and synthetic pursuits.
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In the structure of the title compound C14H9Cl3I2, which is the p-iodophenyl analogue of the insecticide DDT [1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane], isomorphism between the two compounds has been confirmed. In the molecule the dihedral angle between the planes of the two phenyl rings is 65.8(4)deg. which compares with 64.7(7)deg. in DDT.
Resumo:
In the structure of the title compound C22H27Cl302, which is the p-butoxyphenyl analogue of the insecticidally active p-methoxyphenyl compound methoxychlor, the dihedral angle between the two phenyl rings is 79.61(11)deg. Present also in the structure is an intramolecular aromatic C-H...Cl interaction [3.361(2)Ang].
Resumo:
The Australian Accounting Research Foundation (AARF) recently issued Legislative Policy Discussion Paper No.4 which proposes a framework for financial reporting by Australian incorporated associations.This paper comments on both the merits and deficiencies of the proposal. In particular it notes that the proposal simply advocates that the application of differential reporting, accounting standards, and the conceptual framework be imposed on incorporated associations by amended statutes. It is noted that in light of long experience in the corporate sector, he espoused benefits of such a move may not eventuate. Further, concern is expressed that the proposal is a blank cheque one because of the inadequacy of existing relevant accounting standards and the proposal to introduce new relevant standards. Another major defect in the proposal is that it emanates from accountants who acknowledge in their conceptual framework, the need for external reports to report on performance through both financial and non-financial reporting methods. Despite that acknowledgment, the standard set of external reports prepared by accountants do not measure performance as defined in their own conceptual framework (SAC 2) and in their auditing pronouncements (AUP 33), and they have restricted their domain to financial reporting (SAC 2). Accordingly the proposal appears to be seriously deficient and it is suggested that it be rejected and a new proposal be prepared by a multi-party group free from vested interests.
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Bone defects, especially large bone defects, remain a major challenge in orthopaedic surgery. Autologous bone transplantation is considered the most effective treatment, but insufficient donor tissue, coupled with concerns about donor site morbidity, has hindered this approach in large-scale applications. Alternative approaches include implanting biomaterials such as bioactive glass (BG), which has been widely used for bone defect healing, due to having generally good biocompatibility, and can be gradually biodegraded during the process of new bone formation. Mesoporous bioactive glass (MBG) is a newly developed bioactive glass which has been proven to have enhanced in-vitro bioactivity; however the in-vivo osteogenesis has not been studied. A critical problem in using the bone tissue engineering approach to restore large bone defects is that the nutrient supply and cell viability at the centre of the scaffold is severely hampered since the diffusion distance of nutrients and oxygen for cell survival is limited to 150-200µm. Cobalt ions has been shown to mimic hypoxia, which plays a pivotal role in coupling angiogenesis with osteogenesis in-vivo by activating hypoxia inducing factor-1α (HIF-1α) transcription factor, subsequently initiating the expression of genes associated with tissue regeneration. Therefore, one aim of this study is to investigate the in-vivo osteogenesis of MBG by comparison with BG and β-TCP, which are widely used clinically. The other aim is to explore hypoxia-mimicking biomaterials by incorporating Cobalt into MBG and β-TCP. MBG and β-TCP incorporated with 5% cobalt (5Co-MBG and 5CCP) have also been studied in-vivo to determine whether the hypoxic effect has a beneficial effect on the bone formation. The composition and microstructure of synthesised materials (BG, MBG, 5Co-MBG, 5CCP) were characterised, along with the mesopore properties of the MBG materials. Dissolution and cytotoxicity of the Co-containing materials were also investigated. Femoral samples with defects harvested at 4 and 8 weeks were scanned using micro-CT followed by processing for histology (H&E staining) to determine bone formation. Histology of MBG showed a slower rate of bone formation at 4 weeks than BG, however at 8 weeks it could be clearly seen that MBG had more bone formation. The in-vivo results show that the osteogenesis of MBG reciprocates the enhanced performance shown in-vitro compared to BG. Dissolution study showed that Co ions can be efficiently released from MBG and β-TCP in a controllable way. Low amounts of Co incorporated into the MBG and β-TCP showed no significant cytotoxicity and the Co-MBG powders maintained a mesopore structure although not as highly ordered as pure MBG. Preliminary study has shown that Co incorporated samples showed little to no bone formation, instead incurring high lymphocyte activity. Further studies need to be done on Co incorporated materials to determine the cause for high lymphocyte activity in-vivo, which appear to hinder bone formation. In conclusion, this study demonstrated the osteogenic activity of MBG and provided some valuable information of tissue reaction to Co-incorporated MBG and TCP materials.
Resumo:
In the structure of the title compound, [Mg(H2O)2(C8H6FO3)2]n(0.4H2O)n, slightly distorted octahedral MgO6 complex units have crystallographic inversion symmetry, the coordination polyhedron comprising two trans-related water molecules and four carboxyl O-atom donors, two of which are bridging. Within the two-dimensional complex polymer which is parallel to (100), the coordinating water molecules form intermolecular O---H...O hydrogen-bonds with carboxylate and phenoxy O-atom acceptors, as well as with the partial-occupancy solvent water molecules.
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Background We have previously demonstrated that human kidney proximal tubule epithelial cells (PTEC) are able to modulate autologous T and B lymphocyte responses. It is well established that dendritic cells (DC) are responsible for the initiation and direction of adaptive immune responses and that these cells occur in the renal interstitium in close apposition to PTEC under inflammatory disease settings. However, there is no information regarding the interaction of PTEC with DC in an autologous human context. Methods Human monocytes were differentiated into monocyte-derived DC (MoDC) in the absence or presence of primary autologous activated PTEC and matured with polyinosinic:polycytidylic acid [poly(I:C)], while purified, pre-formed myeloid blood DC (CD1c+ BDC) were cultured with autologous activated PTEC in the absence or presence of poly(I:C) stimulation. DC responses were monitored by surface antigen expression, cytokine secretion, antigen uptake capacity and allogeneic T-cell-stimulatory ability. Results The presence of autologous activated PTEC inhibited the differentiation of monocytes to MoDC. Furthermore, MoDC differentiated in the presence of PTEC displayed an immature surface phenotype, efficient phagocytic capacity and, upon poly(I:C) stimulation, secreted low levels of pro-inflammatory cytokine interleukin (IL)-12p70, high levels of anti-inflammatory cytokine IL-10 and induced weak Th1 responses. Similarly, pre-formed CD1c+ BDC matured in the presence of PTEC exhibited an immature tolerogenic surface phenotype, strong endocytic and phagocytic ability and stimulated significantly attenuated T-cell proliferative responses. Conclusions Our data suggest that activated PTEC regulate human autologous immunity via complex interactions with DC. The ability of PTEC to modulate autologous DC function has important implications for the dampening of pro-inflammatory immune responses within the tubulointerstitium in renal injuries. Further dissection of the mechanisms of PTEC modulation of autologous immune responses may offer targets for therapeutic intervention in renal medicine.
Resumo:
The Texas Department of Transportation (TxDOT) is concerned about the widening gap between pavement preservation needs and available funding. Thus, the TxDOT Austin District Pavement Engineer (DPE) has investigated methods to strategically allocate available pavement funding to potential projects that improve the overall performance of the District and Texas highway systems. The primary objective of the study presented in this paper is to develop a network-level project screening and ranking method that supports the Austin District 4-year pavement management plan development. The study developed candidate project selection and ranking algorithms that evaluated pavement conditions of each project candidate using data contained in the Pavement Management Information system (PMIS) database and incorporated insights from Austin District pavement experts; and implemented the developed method and supporting algorithm. This process previously required weeks to complete, but now requires about 10 minutes including data preparation and running the analysis algorithm, which enables the Austin DPE to devote more time and resources to conducting field visits, performing project-level evaluation and testing candidate projects. The case study results showed that the proposed method assisted the DPE in evaluating and prioritizing projects and allocating funds to the right projects at the right time.