3,925 research outputs found
Phase diagram of softly repulsive systems: The Gaussian and inverse-power-law potentials
We redraw, using state-of-the-art methods for free-energy calculations, the
phase diagrams of two reference models for the liquid state: the Gaussian and
inverse-power-law repulsive potentials. Notwithstanding the different behavior
of the two potentials for vanishing interparticle distances, their
thermodynamic properties are similar in a range of densities and temperatures,
being ruled by the competition between the body-centered-cubic (BCC) and
face-centered-cubic (FCC) crystalline structures and the fluid phase. We
confirm the existence of a reentrant BCC phase in the phase diagram of the
Gaussian-core model, just above the triple point. We also trace the BCC-FCC
coexistence line of the inverse-power-law model as a function of the power
exponent and relate the common features in the phase diagrams of such
systems to the softness degree of the interaction.Comment: 22 pages, 8 figure
Safety profile of paediatric COVID-19 vaccines: An analysis of the US Vaccine Adverse Event Reporting System
Aim: To provide further evidence on the safety profile of COVID-19 vaccines in paediatrics by analysing the spontaneous reports of adverse effects related to these vaccines.Methods: Reports related to US paediatric population (from 0 to 17 years) vaccinated with authorised COVID-19 vaccines were extracted from Vaccine Adverse Event Reporting System from December 2020 to 17 November 2022. We conducted a descriptive analysis of Adverse Events Following Immunization (AEFI), calculating reporting rate of serious AEFIs and focusing on myocarditis and Guillain-Barre Syndrome after mRNA COVID-19 vaccines.Results: Overall, 52 720 reports were retrieved: 77% (40541)-Pfizer-BioNTech, 19% (10083)-Moderna, a small proportion for other vaccines 4% (2096). Most of AEFIs were non-serious and listed in corresponding SPCs. Of serious AEFIs, 96% were related to the Pfizer-BioNTech vaccine. Roughly 91% (47874) were related to people from 6 to 17 years, a small percentage of 9% (4773) to the younger group (0-5 years). In both groups, most of the reports were related to mRNA vaccines and the percentage of AEFIs experienced by females were similar to males.Conclusions: Data showed that events most frequently reported were non-serious and listed in the corresponding SPCs, extending the evidence of safety of COVID-19 vaccines authorised in the United States in children
On the accuracy of the melting curves drawn from modelling a solid as an elastic medium
An ongoing problem in the study of a classical many-body system is the
characterization of its equilibrium behaviour by theory or numerical
simulation. For purely repulsive particles, locating the melting line in the
pressure-temperature plane can be especially hard if the interparticle
potential has a softened core or contains some adjustable parameters. A method
is hereby presented that yields reliable melting-curve topologies with
negligible computational effort. It is obtained by combining the Lindemann
melting criterion with a description of the solid phase as an elastic
continuum. A number of examples are given in order to illustrate the scope of
the method and possible shortcomings. For a two-body repulsion of Gaussian
shape, the outcome of the present approach compares favourably with the more
accurate but also more computationally demanding self-consistent harmonic
approximation.Comment: 25 pages, 7 figure
Analisis Kadar Pm10 dan Karbon Monoksida (Co) Serta Keluhan Gangguan Pernafasan Akut pada Petugas Dinas Perhubungan Terminal Amplas Medan Tahun 2014
One of the most potential air pollution resources come from the transportation sector (60-80%), such as carbon monoxide (CO) and PM10. The existence of carbon monoxide and PM10 in the air can cause health problems, especially respiratory disorders for people who breathe it.The purpose of this study is to analyze the levels of PM10 and Carbon Monoxide in the air of the Amplas Terminal Medan. Then to find out of the characteristicsof the respondents and acute respiratory disturbanceswhich was felt by Transport Department officers in Terminal Amplas.This is a descriptive research. This study used total sampling technique, and the population as many as 81 respondents. Data PM10 and Carbon Monoxide levels obtained by direct measurement in Terminal Amplas. Then, acute respiratorydisturbancesdata obtained by interviewed the Transport Department officers in AmplasTerminal.Air measurement result showed that the levels of PM10 and carbon monoxide in the Amplas Terminal did not exceed the threshold value with the average levels of PM10 is 150 mg/m3 and CO is 29 ppm. Most of respondents (58,3%) who worked in the office of the Transport Department did not have acute respiratory disturbancesand most of respondents (68,1%) who worked outside the office had acute respiratory disturbances.The conclusion of this study is the acute respiratory disturbancesfelt by most of respondents was coughing. There is recommended to Kota Medan Transport Dapertment to regulate the office hours of the Transport Department officers in AmplasTerminal
Expression and characterization of the Trypanosoma cruzi dihydrofolate reductase domain
We have cloned and expressed in Escherichia coli a 702-base pair gene coding for the dihydrofolate reductase (DHFR) domain of the bifunctional dihydrofolate reductase-thymidylate synthase (DHFR-TS) from Trypanosoma cruzi. The DHFR domain was purified to homogeneity by methotrexate-Sepharose chromatography followed by an anion-exchange chromatography step in a mono Q column, and displayed a single 27-kDa band on SDS-PAGE. Gel filtration showed that the catalytic domain was expressed as a monomer. Kinetic parameters were similar to those reported for the wild-type bifunctional enzyme with Km values of 0.75 microM for dihydrofolate and 16 microM for NADPH and a kcat value of 16.5 s-1. T. cruzi DHFR is poorly inhibited by trimethoprim and pyrimethamine and the inhibition constants were always lower for the bifunctional enzyme. The binding of methotrexate was characteristic of a class of inhibitors that form an initial complex which isomerizes slowly to a tighter complex and are referred to as 'slow, tight-binding' inhibitors. While the slow-binding step of inhibition was apparently unaffected in the individually expressed DHFR domain, the overall inhibition constant was two-fold higher as a consequence of the superior inhibition constant value obtained for the initial inhibitory complex
Peranan Teknologi Komunikasi Dalam Menciptakan Masyarakat Informasi Di Indonesia
Information society concept has often been heard and analyzed following with information and communication technology development which can’t be avoided by society. At the beginning, information society comes up from the awareness how important information current is. Nations compete for preparing many tools to realize a transition to aim the dream of information society. Computerization as a requirement to concrete information society is claimed to faster the society existence including e-government effort. However, technology can not only be implemented without considering some aspects because it can make new problems
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