11,022 research outputs found
Metalloporphyrin-incorporated diphosphine ligands for metal ion-binding
Poster: no. P48Diphosphine ligands have been widely used in organometallic chemistry and catalysis.1 By incorporation of functional units such as metallomacrocycles, the resulting functionalized diphosphines could exhibit unusual properties or binding behavior. In this study, we prepared several examples of ruthenium porphyrin phosphine complexes [RuII(Por)(dppm)2] (1; Por = TTP, 4-MeO-TPP, F20-TPP; dppm = bis(diphenylphosphino)methane) by a similar method to that previously reported for their congeners.2 Reaction of complexes 1 with a number of metal …published_or_final_versio
Recommended from our members
Development of human single-chain antibodies against SARS-associated coronavirus.
The outbreak of severe acute respiratory syndrome (SARS), caused by a distinct coronavirus, in 2003 greatly threatened public health in China, Southeast Asia as well as North America. Over 1,000 patients died of the SARS virus, representing 10% of infected people. Like other coronaviruses, the SARS virus also utilizes a surface glycoprotein, namely the spike protein, to infect host cells. The spike protein of SARS virus consists of 1,255 amino acid residues and can be divided into two sub-domains, S1 and S2. The S1 domain mediates the binding of the virus to its receptor angiotensin-converting enzyme 2, which is abundantly distributed on the surface of human lung cells. The S2 domain mediates membrane fusion between the virus and the host cell. Hence two strategies can be used to block the infection of the SARS virus, either by interfering with the binding of the S1 domain to the receptor or by blocking the fusion of the virus with the cell membrane mediated by the S2 domain. Several antibodies against the S1 domain have been generated and all of them are able to neutralize the virus in vitro and in vivo using animal models. Unfortunately, point mutations have been identified in the S1 domain, so that the virus isolated in the future may not be recognized by these antibodies. As no mutation has been found in the S2 domain indicating that this region is more conserved than the S1 domain, it may be a better target for antibody binding. After predicting the immunogenicity of the epitopes of the S2 domain, we chemically synthesized two peptides and also expressed one of them using a recombinant DNA method. We screened a phage displaying library of human single-chain antibodies (ScFv) against the predicted epitopes and obtained a human ScFv which can recognize the SARS virus in vitro
Controlling Curie temperature in (Ga,Ms)As through location of the Fermi level within the impurity band
The ferromagnetic semiconductor (Ga,Mn)As has emerged as the most studied
material for prototype applications in semiconductor spintronics. Because
ferromagnetism in (Ga,Mn)As is hole-mediated, the nature of the hole states has
direct and crucial bearing on its Curie temperature TC. It is vigorously
debated, however, whether holes in (Ga,Mn)As reside in the valence band or in
an impurity band. In this paper we combine results of channeling experiments,
which measure the concentrations both of Mn ions and of holes relevant to the
ferromagnetic order, with magnetization, transport, and magneto-optical data to
address this issue. Taken together, these measurements provide strong evidence
that it is the location of the Fermi level within the impurity band that
determines TC through determining the degree of hole localization. This finding
differs drastically from the often accepted view that TC is controlled by
valence band holes, thus opening new avenues for achieving higher values of TC.Comment: 5 figures, supplementary material include
Case-Fatality Ratio of Blood Culture-Confirmed Typhoid Fever in Dhaka, Bangladesh.
With impending rollout of new conjugate typhoid vaccines, better estimates of typhoid case-fatality ratio are needed for countries to set priorities for public health programs. We enrolled 1425 patients of all ages with blood culture-confirmed Salmonella Typhi from laboratory networks serving inpatients and outpatients in Dhaka, Bangladesh. Participants were asked about symptoms and complications including death experienced over a median 3-month period following blood culture diagnosis. Four fatal cases were identified (case-fatality ratio of 0.3% [95% confidence interval, .05%-.55%]). Applying this case-fatality ratio to global typhoid burden estimates would reduce deaths by 70%
The effects of stent porosity on the endovascular treatment of intracranial aneurysms located near a bifurcation
published_or_final_versio
Long term results of Gamma Knife surgery for trigeminal neuralgia using 90 Gy distal to root entry zone protocol
Meeting Theme: Degenerative Lumbar SpineFree Paper 7OBJECT: Gamma Knife surgery (GKS) is one of the options for medically refractory trigeminal neuralgia (TN), but long term results were regarded as inferior to microvascular decompression (MVD). The authors reported the long term results of treating primary TN by GKS, using a high dose non root entry zone protocol. METHODS: 64 patients between March 1995 and June 2013 were included. Minimum follow up time was 12 months. Mean age was 62 years. Follow up duration was mean 76 months (median 61 months, range 12-210 months). Radiosurgical technique included TN frame position, 3D MRI, and one 4 mm shot delivering 90 Gy maximum at the cisternal part …published_or_final_versio
Towards zero facial palsy in management of large acoustic neuroma: combining the merits of microsurgery and radiosurgery
Free Paper 7Meeting Theme: Degenerative Lumbar SpineOBJECT: Despite advances in microsurgical techniques, complete surgical resection of large acoustic neuroma is still associated with significant morbidity related to facial palsy. By modifying the techniques of microsurgery and combined it with planned post-operative radiosurgery, the authors aimed to reduce the incidence of permanent facial nerve palsy to near zero in a prospective study. METHODS: Between 2000 and 2011, 54 large (Koo’s classification stage 4) acoustic neuromas (AN), were managed by the senior authors with planned microsurgery (MS) followed by Gamma Knife surgery (GKS). Mean tumor volume before MS was 17.6 cc (4.9 - 44.5). Mean follow up time was 70 months with minimum 3 years follow up. The authors adhered …published_or_final_versio
Selection of solar energy for green building using superiority and inferiority multi-criteria
Author name used in this publication: K. M. YuVersion of RecordPublishe
Computational fluid dynamics study of bifurcation aneurysms treated with pipeline embolization device: side branch diameter study
An intracranial aneurysm, abnormal swelling of the cerebral artery, may lead to undesirable rates of mortality and morbidity upon rupture. Endovascular treatment involves the deployment of a flow-diverting stent that covers the aneurysm orifice, thereby reducing the blood flow into the aneurysm and mitigating the risk of rupture. In this study, computational fluid dynamics analysis is performed on a bifurcation model to investigate the change in hemodynamics with various side branch diameters. The condition after the deployment of a pipeline embolization device is also simulated. Hemodynamic factors such as flow velocity, pressure, and wall shear stress are studied. Aneurysms with a larger side branch vessel might have greater risk after treatment in terms of hemodynamics. Although a stent could lead to flow reduction entering the aneurysm, it would drastically alter the flow rate inside the side branch vessel. This may result in side-branch hypoperfusion subsequent to stenting. In addition, two patient-specific bifurcation aneurysms are tested, and the results show good agreement with the idealized models. Furthermore, the peripheral resistance of downstream vessels is investigated by varying the outlet pressure conditions. This quantitative analysis can assist in treatment planning and therapeutic decision-making.published_or_final_versio
- …