35 research outputs found
Si doped T6 carbon structure as an anode material for Li-ion batteries: An ab initio study
First-principles calculations are performed to identify the pristine and Si doped 3D metallic T6 carbon structure (having both sp(2) and sp(3) type hybridization) as a new carbon based anode material. The pi electron of C-2 atoms (sp2 bonded) forms an out of plane network that helps to capture the Li atom. The highest Li storage capacity of Si doped T6 structure with conformation Li1.7Si1C5 produces theoretical specific capacity of 632 mAh/g which substantially exceeding than graphite. Also, open-circuit voltage (OCV) with respect to Li metal shows large negative when compared to the pristine T6 structure. This indicates modifications in terms of chemical properties are required in anode materials for practical application. Among various doped (Si, Ge, Sn, B, N) configuration, Si doped T6 structure provides a stable positive OCV for high Li concentrations. Likewise, volume expansion study also shows Si doped T6 structure is more stable with less pulverization and substantial capacity losses in comparison with graphite and silicon as an anode materials. Overall, mixed hybridized (sp(2) + sp(3)) Si doped T6 structure can become a superior anode material than present sp2 hybridized graphite and sp(3) hybridized Si structure for modern Lithium ion batteries.ope
Understanding voltage decay in lithium-excess layered cathode materials through oxygen-centred structural arrangement
Lithium-excess 3d-transition-metal layered oxides (Li1+xNiyCozMn1-x-y-zO2, > 250 mAh g(-1)) suffer from severe voltage decay upon cycling, which decreases energy density and hinders further research and development. Nevertheless, the lack of understanding on chemical and structural uniqueness of the material prevents the interpretation of internal degradation chemistry. Here, we discover a fundamental reason of the voltage decay phenomenon by comparing ordered and cation-disordered materials with a combination of X-ray absorption spectroscopy and transmission electron microscopy studies. The cation arrangement determines the transition metal-oxygen covalency and structural reversibility related to voltage decay. The identification of structural arrangement with de-lithiated oxygen-centred octahedron and interactions between octahedrons affecting the oxygen stability and transition metal mobility of layered oxide provides the insight into the degradation chemistry of cathode materials and a way to develop high-energy density electrodes
Antigenic Proteins Involved in Occupational Rhinitis 1 and Asthma Caused by Obeche Wood (Triplochiton Scleroxylon)
Background
Obeche wood dust is a known cause of occupational asthma where an IgE-mediated mechanism has been demonstrated.
Objective
To characterize the allergenic profile of obeche wood dust and evaluate the reactivity of the proteins by in vitro, ex vivo and in vivo assays in carpenters with confirmed rhinitis and/or asthma
Materials and methods
An in-house obeche extract was obtained, and two IgE binding bands were purified (24 and 12 kDa) and sequenced by N-terminal identity. Specific IgE and IgG, basophil activation tests and skin prick tests (SPTs) were performed with whole extract and purified proteins. CCD binding was analyzed by ELISA inhibition studies.
Results
Sixty-two subjects participated: 12 with confirmed occupational asthma/rhinitis (ORA+), 40 asymptomatic exposed (ORAâ), and 10 controls. Of the confirmed subjects, 83% had a positive SPT to obeche. There was a 100% recognition by ELISA in symptomatic subjects vs. 30% and 10% in asymptomatic exposed subjects and controls respectively (p<0.05). Two new proteins were purified, a 24 kDa protein identified as a putative thaumatin-like protein and a 12 kDa gamma-expansin. Both showed allergenic activity in vitro, with the putative thaumatin being the most active, with 92% recognition by ELISA and 100% by basophil activation test in ORA+ subjects. Cross-reactivity due to CCD was ruled out in 82% of cases.
Conclusions
Two proteins of obeche wood were identified and were recognized by a high percentage of symptomatic subjects and by a small proportion of asymptomatic exposed subjects. Further studies are required to evaluate cross reactivity with other plant allergens
Functional polymorphisms in genes of the Angiotensin and Serotonin systems and risk of hypertrophic cardiomyopathy: AT1R as a potential modifier
<p>Abstract</p> <p>Background</p> <p>Angiotensin and serotonin have been identified as inducers of cardiac hypertrophy. DNA polymorphisms at the genes encoding components of the angiotensin and serotonin systems have been associated with the risk of developing cardiovascular diseases, including left ventricular hypertrophy (LVH).</p> <p>Methods</p> <p>We genotyped five polymorphisms of the <it>AGT</it>, <it>ACE</it>, <it>AT1R</it>, <it>5-HT2A</it>, and <it>5-HTT </it>genes in 245 patients with Hypertrophic Cardiomyopathy (HCM; 205 without an identified sarcomeric gene mutation), in 145 patients with LVH secondary to hypertension, and 300 healthy controls.</p> <p>Results</p> <p>We found a significantly higher frequency of <it>AT1R </it>1166 C carriers (CC+AC) among the HCM patients without sarcomeric mutations compared to controls (p = 0.015; OR = 1.56; 95%CI = 1.09-2.23). The <it>AT1R </it>1166 C was also more frequent among patients who had at least one affected relative, compared to sporadic cases. This allele was also associated with higher left ventricular wall thickness in both, HCM patients with and without sarcomeric mutations.</p> <p>Conclusions</p> <p>The 1166 C <it>AT1R </it>allele could be a risk factor for cardiac hypertrophy in patients without sarcomeric mutations. Other variants at the <it>AGT</it>, <it>ACE</it>, <it>5-HT2A </it>and <it>5-HTT </it>did not contribute to the risk of cardiac hypertrophy.</p
Clinical Experience With an L-ProlineâStabilized 10Â % Intravenous Immunoglobulin (PrivigenÂź): Real-Life Effectiveness and Tolerability
PURPOSE: This retrospective study evaluated the effectiveness and tolerability in clinical practice of an L-prolineâstabilized 10 % intravenous immunoglobulin (IVIG; PrivigenÂź) in patients with primary (PID) or secondary immunodeficiency (SID). METHODS: Patients from 6 centers in Europe and the US were treated with individually determined regimens of PrivigenÂź for â„3 months. Serum immunoglobulin G (IgG) trough levels, annualized rates of infection, hospitalization and antibiotics use, and the incidence of adverse events (AEs) were analyzed. RESULTS: Of 72 patients, three infants with severe combined immunodeficiency (SCID) were analyzed separately. The remaining 69 patients (52.2 % male; median age 38 years [range: 0.1â90.0]) with PID (82.6 %) or SID (17.4 %) received a mean (±standard deviation) PrivigenÂź dose of 532â±â250 mg/kg/month resulting in trough serum IgG levels of 407â1,581 mg/dL (median: 954 mg/dL). Ten patients (14.5 %) experienced 11 serious bacterial infections over 22.0â±â15.0 months of treatment (0.087 events/patient/year, upper one-sided 99 % confidence interval: 0.170), the most common being pneumonia (11.6 %). The rates for any infection and hospitalization were 1.082 events/patient/year and 3.63 days/patient/year, respectively. Two patients with severe disease accounted for 303 of 460 hospital days. Across all 72 patients, 13 (18.1 %) patients experienced AEs, including 10 (13.9 %) patients with AEs at least possibly related to PrivigenÂź, including headache (8.3 %), fever, and chills (2.8 % each). No related serious AEs were reported. One infant with SCID died due to severe viral infection. CONCLUSIONS: Despite the heterogeneous population, effectiveness and tolerability of PrivigenÂź in clinical practice closely matched those reported in clinical studies