729 research outputs found
Health insurance in Zaire
This study of health insurance systems in Zaire was carried out as part of a larger program of initiatives designed to improve the sustainability of health care systems and increase the health status of the Zairian population. This paper presents the objectives of the study and a discussion of the economic aspects of health insurance, background information about the health sector and health financing systems in Zaire and highlights of previous related work. The major motivations for this study were: (a) to provide information for the ongoing social sector adjustment dialogue in Zaire; and (b) to serve as a case study in the World Bank's Region Study of Health Finance. Specifically, the study sought to document different types of insurance systems in Zaire, and to conduct in-depth case studies of several schemes. The in-depth case studies presented in this report evaluate the design, management operational efficiency of four health insurance programs from both rural and urban areas. The case studies also attempt to analyze the effects of insurance on equity of access, utilization of health care services, and mobilization of financial resources for the health sector. From these analyses, the report draws conclusions about the advantages and disadvantages of health insurance programs as a means of financing health care services in Zaire, and suggests avenues for future research, policy, and programming initiatives.Health Monitoring&Evaluation,Insurance Law,Health Economics&Finance,Insurance&Risk Mitigation,Health Systems Development&Reform
Consequences of Postnatally Elevated Insulin-Like Growth Factor-II in Transgenic Mice: Endocrine Changes and Effects on Body and Organ Growth.
Insulin-like growth factor-II (IGF-II) is an important regulator of
embryonic growth and differentiation, but its function in postnatal life
is unclear. To address this point, we generated transgenic mice harboring
fusion genes in which a human IGF-II complementary DNA is
placed under the transcriptional control of the rat phosphoenolpyruvate
carboxykinase promoter. Transgene-specific messenger RNA was detected
in liver, kidney, and several parts of the gut. Serum IGF-II levels
in transgenic mice were 2-3 times higher than those in controls and
increased after starvation. Circulating IGF-I correlated negatively and
IGF-binding protein-2 (IGFBP-2) positively with IGF-II levels, suggesting
that IGF-I is displaced from IGFBPs by IGF-II and that IGFII
is a major regulator of IGFBP-2. Serum levels of IGFBP-3 and
IGFBP-4 tended to be higher in phosphoenolpyruvate carboxykinase-
IGF-II transgenic mice than in controls, as evaluated by ligand blot
analysis. Starvation reduced serum IGF-I, but increased IGFBP-2 in
transgenic mice more markedly than in controls. Fasting insulin levels
were significantly reduced in transgenic mice, whereas glucose levels
were not influenced by elevated IGF-II. The body growth of 4- and 12-
week-old mice was not significantly influenced by elevated IGF-II, but
transgenic mice displayed increased kidney and testis weight at the age
of 4 weeks, and increased adrenal weight at the age of 12 weeks. Our
results demonstrate that elevated IGF-II in postnatal life has multiple
endocrine consequences and subtle time-specific effects on organ
growth
Studies in aryne chemistry
The principal methods for the generation of arynes,
and the Diels–Alder reactions of steroidal dienes are
briefly reviewed.
Tetrafluorobenzyne (generated from pentafluorophenyl-lithium and pentafluorophenyl magnesium chloride) reacts
with simple models for steroidal diene systems to give
mainly 1,4-addition products.
Benzyne (generated from o-bromofluorobenzene and
anthranilic acid), tetrachlorobenzyne (from tetrachloroanthranilic
acid) and tetrafluorobenzyne react with
steroidal-5,7-dienes to give products of the ene-reaction.
In addition, tetrafluorobenzyne forms a 5,8-adduct with a
5,7-diene and with a 5,7,9(11)-triene.
Cholesta-2,4-diene gives 1,4-adducts with benzyne and
tetrafluorobenzyne which undergo retro-Diels–Alder reactions
on pyrolysis. Steroidal-1(10),9(11)-dienes also give 1,11-adducts
with benzyne and tetrachlorobenzyne.
The adducts of tetrafluorobenzyne with models for the oestrogen
steroids, and with oestradiol dimethyl ether are reported. An
unsuccessful attempt to synthesise an adduct from a steroidal
styrene is described.
Finally the photoisomerisation of 5,6,7,8-tetrafluoro-1,4-dihydro-1,4-ethanonaphthalene is reported and a mechanism proposed
is sponsored by the Office of Health, Infectious Diseases and Nutrition Bureau for Global Health
The guidelines were prepared b
Simulation of haemodynamic flow in head and neck cancer chemotherapy
<p>Abstract</p> <p>Background</p> <p>In recent years, intra arterial chemotherapy has become an important component in head and neck cancer treatment. However, therapy success can vary significantly and consistent treatment guidelines are missing. The purpose of this study was to create a computer simulation of the chemical agent injection in the head and neck arteries to investigate the distribution and concentration of the chemical.</p> <p>Methods</p> <p>Realistic three dimensional patient specific geometry was created from image scan data. Pulsatile blood flow, turbulence, the chemical agent injection via a catheter, and the mixture between blood and the chemical were then simulated through the arterial network by computational fluid dynamics software.</p> <p>Results</p> <p>The results show a consistent chemical distribution throughout all the arteries and this is ineffective. In addition, due to high wall shear stress and turbulence at the inner bifurcation wall, serious complications during the treatment could occur, for instance haemolysis or thrombosis.</p> <p>Conclusions</p> <p>The modelled catheter position is insufficient to provide a high chemical agent concentration in the desired tumour feeding artery, which is vital for therapy success.</p
First principles modeling of 3d-metal doped three-layer fluorite-structured TiO2 (4,4) nanotube to be used for photocatalytic hydrogen production
This study has been supported by the EC ERA.Net RUS Plus project No. 237 WATERSPLIT, Russian Basic Research Foundation
No. 16-53-76019, and additionally by the IMIS2 Program (Latvia). The authors are also indebted to R. A. Evarestov and O. Lisovski for stimulating discussions as well as to A. Chesnokov for technical assistance.We have estimated theoretically the photocatalytic suitability of thinnest single-wall fluorite-structured titania (4,4) nanotube (NT) possessing three layers each (O-Ti-O) and doped by Sc, V, Cr, Mn, Fe, Co, Ni, Cu and Zn atoms substituted for host Ti atoms. For this goal, we have performed large-scale ab initio calculations on TiO2 NTs with three-layer morphology doped by 3d transition metals, using (i) the method of linear combination of atom-centered Gaussian-type orbitals (LCAO) based on the hybrid density functional theory (DFT) incorporating the Hartree-Fock (HF) exchange contribution (DFT+HF) and (ii) the method of linearized augmented cylindrical waves (LACW) with the muffin-tin approximation based on the local density functional approach (LDA). We have compared the ground state electronic structure, particularly the one-electron densities of states (DOSs) from the LCAO and LACW calculations for periodic arrangements of the 3d-metal dopant atoms. The results show clear evidence for a potential photocatalytic application for water splitting in the case of the Sc-doped titania nanotubes only. These NTs show both a reduced band gap of 2.0 eV relative to the pristine NT and an absence of defect-induced levels between the redox potentials of hydrogen and oxygen, so that electron-hole recombination becomes unlikely. Other 3d dopants with higher atomic number, although their band gap also covers the favorable green to orange region of the solar spectrum, are unsuitable because their defect-induced levels are positioned between the redox potential of oxygen and hydrogen, which can be expected to lead to rapid electron-hole recombination.--//--Dmitry Bocharov, Sergei Piskunov, Yuri F. Zhukovskii, Eckhard Spohr, Pavel N. D'yachkov,
First principles modeling of 3d-metal doped three-layer fluorite-structured TiO2 (4,4) nanotube to be used for photocatalytic hydrogen production, Vacuum, Volume 146, 2017, Pages 562-569, ISSN 0042-207X, https://doi.org/10.1016/j.vacuum.2017.05.002.EC ERA.Net RUS Plus project No. 237 WATERSPLIT; Russian Basic Research Foundation No. 16-53-76019; IMIS2 Program (Latvia); Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017 TeamingPhase2 under grant agreement No. 739508, project CAMART2
Co-utilization of L-arabinose and D-xylose by laboratory and industrial Saccharomyces cerevisiae strains
BACKGROUND: Fermentation of lignocellulosic biomass is an attractive alternative for the production of bioethanol. Traditionally, the yeast Saccharomyces cerevisiae is used in industrial ethanol fermentations. However, S. cerevisiae is naturally not able to ferment the pentose sugars D-xylose and L-arabinose, which are present in high amounts in lignocellulosic raw materials. RESULTS: We describe the engineering of laboratory and industrial S. cerevisiae strains to co-ferment the pentose sugars D-xylose and L-arabinose. Introduction of a fungal xylose and a bacterial arabinose pathway resulted in strains able to grow on both pentose sugars. Introduction of a xylose pathway into an arabinose-fermenting laboratory strain resulted in nearly complete conversion of arabinose into arabitol due to the L-arabinose reductase activity of the xylose reductase. The industrial strain displayed lower arabitol yield and increased ethanol yield from xylose and arabinose. CONCLUSION: Our work demonstrates simultaneous co-utilization of xylose and arabinose in recombinant strains of S. cerevisiae. In addition, the co-utilization of arabinose together with xylose significantly reduced formation of the by-product xylitol, which contributed to improved ethanol production
Leptin promotes meiotic progression and developmental capacity of bovine oocytes via cumulus cell-independent and -dependent mechanisms
Leptin has been shown to exert positive effects during the maturation of bovine oocytes, influencing blastocyst development, apoptosis, and the transcript levels of developmentally important genes. The present study was conducted to characterize further the mechanisms of leptin action on oocytes and the role of cumulus cells (CCs) in this context. In the first series of experiments, cumulus-oocyte complexes (COCs) were matured in serum-free medium that contained 0, 1 or 10 ng/ml leptin or in medium that was supplemented with 10% (v/v) estrus cow serum (ECS). Leptin concentrations of 1 and 10 ng/ml stimulated the meiotic progression of oocytes. Moreover, TUNEL staining demonstrated that these leptin doses reduced the proportion of apoptotic CCs. In the second series of experiments, COCs or denuded oocytes (DOs) were matured in the presence of 0 or 10 ng/ml leptin. The percentages of COCs and DOs with extruded polar bodies were increased by leptin. In contrast, positive effects of leptin on fertilization rates and blastocyst development were only observed after treatment of COCs but not of DOs. Leptin treatment of COCs consistently enhanced blastocyst development even after parthenogenetic activation of oocytes or after the removal of CCs before fertilization. The proportion of polyspermic oocytes was not affected by leptin treatment or oocyte denudation. In the third series of experiments, COCs were matured in the presence of 0, 1 or 10 ng/ml leptin. The transcript levels of specific genes were determined by reverse transcriptase-quantitative PCR (RT-qPCR) analysis of cumulus cells and single oocytes. Leptin treatment increased the levels of FAS, FASLG, and STAT3 transcripts in oocytes, but did not affect the LEPR, BAX, and BIRC4 mRNA concentrations. In cumulus cells, leptin treatment increased the mRNA levels for LEPR, STAT3, BAX, BIRC4, and FAS, but did not alter FASLG mRNA abundance. In conclusion, leptin differentially regulates gene expression in oocytes and cumulus cells. Moreover, leptin enhances both oocyte maturation and developmental capacity via cumulus cell-independent and -dependent mechanisms
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