699 research outputs found
Free Vibrations and Buckling of a Thin Cylindrical Shell of Variable Thickness with Curvelinear Edge
Low-frequency vibrations and buckling under an uniform external lateral pressure of a thin cylindrical shell of variable thickness with curvelinear edge are analyzed. The asymptotic and finite element methods are used to get the vibration frequencies and critical loads. The vibration and buckling modes are also presented. The comparison of numerical and asymptotic results is performed
Homoeopathic Medicines of Virginian Witch Hazel: Dosage Forms and Standardisation
According to the authors’ analysis of regulatory documents for homoeopathic medicines of Virginian witch hazel (Hamamelis virginiana L.), there is a need to transform quality assessment approaches and to unify analytical procedures for identification and assay tests.The aim of the study was to determine approaches to identification and assay of homoeopathic mother tinctures of Virginian witch hazel leaves and bark and medicinal products based on the tinctures.Materials and methods: in order to select quality evaluation procedures, the authors analysed scientific literature, Russian and foreign pharmacopoeias and regulatory documentation regarding homoeopathic medicines of Witch hazel. The authors performed practical evaluation of the selected procedures based on thin-layer chromatography, spectrophotometry, qualitative reactions, and titrimetry, using samples of homoeopathic mother tinctures of Witch hazel leaves and bark, as well as corresponding homoeopathic medicinal products in various dosage forms.Results: the authors proposed identification and assay procedures for the studied active pharmaceutical ingredients (APIs) and homoeopathic medicinal products and prepared the drafts of pharmacopoeial monographs Hamamelis virginiana e foliis (Hamamelis, Folium) homoeopathic mother tincture and Hamamelis virginiana (Hamamelis) homoeopathic mother tincture. The unified procedures were included in the draft monographs for homoeopathic medicinal products Hamamelis, homoeopathic drops; Hamamelis D1, homoeopathic ointment; Hamamelis, folium D1, homoeopathic ointment; Hamamelis virginiana e foliis D1, rectal homoeopathic suppositories.Conclusions: the developed procedures are compatible with the principle of holistic, end-to-end standardisation, as they make it possible to carry out identification tests and assays using the same class of biologically active compounds throughout the whole range of homoeopathic medicines from APIs to finished products. The authors proposed the methodology for assessing homoeopathic medicinal products’ quality, taking into account the degree of dilution of the homoeopathic tinctures used
The use of remotely sensed environmental parameters for spatial and temporal schistosomiasis prediction across climate zones in Ghana
Schistosomiasis control in sub-Saharan Africa is enacted primarily through preventive chemotherapy. Predictive models can play an important role in filling knowledge gaps in the distribution of the disease and help guide the allocation of limited resources. Previous modeling approaches have used localized cross-sectional survey data and environmental data typically collected at a discrete point in time. In this analysis, 8 years (2008-2015) of monthly schistosomiasis cases reported into Ghana's national surveillance system were used to assess temporal and spatial relationships between disease rates and three remotely sensed environmental variables: land surface temperature (LST), normalized difference vegetation index (NDVI), and accumulated precipitation (AP). Furthermore, the analysis was stratified by three major and nine minor climate zones, defined using a new climate classification method. Results showed a downward trend in reported disease rates (~ 1% per month) for all climate zones. Seasonality was present in the north with two peaks (March and September), and in the middle of the country with a single peak (July). Lowest disease rates were observed in December/January across climate zones. Seasonal patterns in the environmental variables and their associations with reported schistosomiasis infection rates varied across climate zones. Precipitation consistently demonstrated a positive association with disease outcome, with a 1-cm increase in rainfall contributing a 0.3-1.6% increase in monthly reported schistosomiasis infection rates. Generally, surveillance of neglected tropical diseases (NTDs) in low-income countries continues to suffer from data quality issues. However, with systematic improvements, our approach demonstrates a way for health departments to use routine surveillance data in combination with publicly available remote sensing data to analyze disease patterns with wide geographic coverage and varying levels of spatial and temporal aggregation.Accepted manuscrip
Creation of functional solid-state composites based on black peat
The paper presents investigations of composite materials based on black peats of Barabinskoe and Taganskoe deposits of the Tomsk region and carboxymethyl cellulose, both modified with iron (Ш) and copper (II) chloride solutions. In order to improve hydrophobic properties of compositions, optimum salt concentrations are detected. Water sorption and desorption isotherms are obtained for modified specimens. It is suggested to employ synthesized solid-state compositions as insulators in the capacity of both humidity controller and indoor-contaminant absorber
Seasonality of Rotavirus in South Asia: A Meta-Analysis Approach Assessing Associations with Temperature, Precipitation, and Vegetation Index
Rotavirus infection causes a significant proportion of diarrhea in infants and young children worldwide leading to dehydration, hospitalization, and in some cases death. Rotavirus infection represents a significant burden of disease in developing countries, such as those in South Asia.We conducted a meta-analysis to examine how patterns of rotavirus infection relate to temperature and precipitation in South Asia. Monthly rotavirus data were abstracted from 39 published epidemiological studies and related to monthly aggregated ambient temperature and cumulative precipitation for each study location using linear mixed-effects models. We also considered associations with vegetation index, gathered from remote sensing data. Finally, we assessed whether the relationship varied in tropical climates and humid mid-latitude climates.Overall, as well as in tropical and humid mid-latitude climates, low temperature and precipitation levels are significant predictors of an increased rate of rotaviral diarrhea. A 1°C decrease in monthly ambient temperature and a decrease of 10 mm in precipitation are associated with 1.3% and 0.3% increase above the annual level in rotavirus infections, respectively. When assessing lagged relationships, temperature and precipitation in the previous month remained significant predictors and the association with temperature was stronger in the tropical climate. The same association was seen for vegetation index; a seasonal decline of 0.1 units results in a 3.8% increase in rate of rotavirus.In South Asia the highest rate of rotavirus was seen in the colder, drier months. Meteorological characteristics can be used to better focus and target public health prevention programs
Spatiotemporal patterns of cholera hospitalization in Vellore, India
Systematically collected hospitalization records provide valuable insight into disease patterns and support comprehensive national infectious disease surveillance networks. Hospitalization records detailing patient’s place of residence (PoR) can be utilized to better understand a hospital’s case load and strengthen surveillance among mobile populations. This study examined geographic patterns of patients treated for cholera at a major hospital in south India. We abstracted 1401 laboratory-confirmed cases of cholera between 2000–2014 from logbooks and electronic health records (EHRs) maintained by the Christian Medical College (CMC) in Vellore, Tamil Nadu, India. We constructed spatial trend models and identified two distinct clusters of patient residence—one around Vellore (836 records (61.2%)) and one in Bengal (294 records (21.5%)). We further characterized differences in peak timing and disease trend among these clusters to identify differences in cholera exposure among local and visiting populations. We found that the two clusters differ by their patient profiles, with patients in the Bengal cluster being most likely older males traveling to Vellore. Both clusters show well-aligned seasonal peaks in mid-July, only one week apart, with similar downward trend and proportion of predominant O1 serotype. Large hospitals can thus harness EHRs for surveillance by utilizing patients’ PoRs to study disease patterns among resident and visitor populations
Three Dimensional Relativistic Electromagnetic Sub-cycle Solitons
Three dimensional (3D) relativistic electromagnetic sub-cycle solitons were
observed in 3D Particle-in-Cell simulations of an intense short laser pulse
propagation in an underdense plasma. Their structure resembles that of an
oscillating electric dipole with a poloidal electric field and a toroidal
magnetic field that oscillate in-phase with the electron density with frequency
below the Langmuir frequency. On the ion time scale the soliton undergoes a
Coulomb explosion of its core, resulting in ion acceleration, and then evolves
into a slowly expanding quasi-neutral cavity.Comment: 5 pages, 6 figures;
http://www.ile.osaka-u.ac.jp/research/TSI/Timur/soliton/index.htm
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