262 research outputs found
Improving the virtualâsource method by wavefield separation
The virtual source method has recently been proposed to image and monitor below complex and time-varying over-burden. The method requires surface shooting recorded at downhole receivers placed below the distorting or changing part of the overburden. Redatuming with the measured Greenâs function allows the reconstruction of a complete downhole survey as if the sources were also buried at the re-ceiver locations. There are still some challenges that need to be addressed in the virtual source method, such as limited ac-quisition aperture and energy coming from the overburden. We demonstrate that up-down wavefield separation can sub-stantially improve the quality of virtual source data. First, it allows us to eliminate artifacts associated with the limited ac-quisition aperture typically used in practice. Second, it allows us to reconstruct a new optimized response in the absence of downgoing reflections and multiples from the overburden. These improvements are illustrated on a synthetic data set of a complex layered model modeled after the Fahud field in Oman, and on ocean-bottom seismic data acquired in the Mars field in the deepwater Gulf of Mexico
Health care reform in Russia
The break-up of the former Soviet Union has created a greater realisation of the health and health care deficiencies of what are now independent states and the need for reform. The purpose of these two papers is to describe these deficiencies and set the scene for the establishment of some form of national health insurance in Russia and the other states in the near future. The level of infant mortality across the former Soviet Union in 1990 was 21.8 per thousand. This average disguised wide regional variations, from 32 to 55 per thousand in the rural areas of Middle Asia to 11 to 18 per thousand in the more economically developed areas of the Baltic Republics, Russia, Byelorussia and the Ukraine. Average life expectancy in 1989 was 69.5 years, 64.6 years for men and 74 years for woman, and there were significant regional variations. The major cause of death is cardio-vascular disease and there is evidence not only of late diagnosis of disease but also of a large proportion of chronic diseases being undetected. During the 1980s the health service expanded: more doctors were employed, the hospital bed stock increased and outpatient clinic capacity rose. The rate of hospitalisation is high and the utilisation of facilities us poor e.g. average length of stay exceeds 15 days. Any reforms will need to change the funding of health care and im prove the efficiency of the delivery system. Thus reformers are discussing the decentralisation of management functions away from the centre to the regions, improvements in management training, and improved coordination between the primary and secondary parts of the health care system. Experiments involving decentralising budgets being related to activity and outcome goals have been carried out in various parts of Russia. In Russian, legislation has been passed to introduce health insurance from January 1st 1993. The fine detail of this scheme, even at this late stage, is still undecided. Furthermore the infrastructure to collect and distribute funds has not been created. Further legislation has been introduced which separates consumers, purchasers and providers. The health and health care problems in Russia and other parts of the former Soviet Union are great and the ambitions for reform are well articulated at the level of principle. However, the translation of these principles into practice, when the economy is facing high levels of inflation and decreasing output, and when the administrative structures to facilitate the finance and management of the proposed decentralisation system are absent, is a mammoth task. These papers demonstrate that Russian academics and policy makers recognise these problems and are rising to the challenge of resolving them.Russia, Soviet Union
TRACE ELEMENTS CONTENTS DYNAMICS IN WHOLE BLOOD IN CHILDREN WITH END STAGE RENAL DISEASE RECEIVING DIALYSIS
Homeostasis disorders in kidneys damage is accompanied by the accumulation or reduction of trace elements as a component of Chronic Kidney Disease (CKD) progression. The degree of trace elements misbalanced depends on the stage of CKD. The deep disorders are most common during renal replacement therapy (RRT), especially in children due to anatomic and physiological immaturity.
Materials and methods: We investigated the 20 trace elements blood concentrations in 42 children with CKD V D depending on RRT duration used the technique of inductive coupled plasma mass-spectrometry (ICPMS).
Results: There is detected significant increase of cobalt (in 3,80 times), cadmium (2,66), lead (2,44) and nickel (7,19) in patients with statistically weighty decrease in vanadium (1,49), chromium (1,62), arsenic (9,45), strontium (2,02), barium (5,29), rubidium (2,69 and zinc (1,46). It was found the increasing levels of aluminum, chromium and zinc in RRT duration enlargement (p<0,05).
Conclusions: The course of CKD V D in children is accompanied with substantial and multidirectional changes in trace elements blood levels that characterized by a predominance of accumulation processes versus elimination depending the RRT duration
CHANGES OF NONESSENTIAL TRACE ELEMENTS LEVELS IN WHOLE BLOOD OF END STAGE RENAL DISEASE ADULT PATIENTS
Aims: Accumulation of trace elements occurs in conditions of decreased or termination of kidneys functions. In some conditions increased trace elements can obtain toxic features. On other hand, researches are showing that concentration of some trace elements could be decreased in ERSD patients, too. The most important factor affecting trace element concentration in ERSD patient is the degree of renal failure and using of replacement therapy.
Materials and methods: We determined the concentration of microelements (beryllium, boron, aluminum, vanadium, chromium, nickel, arsenic, rubidium, strontium, cadmium, cesium, barium, thallium and lead) in whole blood of 41 ESRD patients with chronic kidney disease stage VD, who were treated with hemodialysis / hemodiafiltration and in 61 conditionally healthy donors. Determination of whole bloods trace elements content was conducted using inductive coupled plasma mass- spectrometry (ICPMS).
 Results: It is determinate that levels of beryllium, boron, aluminum, vanadium, chromium, strontium, cadmium, barium, thallium and lead is reliable increased in ESRD patients. Decreased levels are observed for nickel, arsenic, cesium and rubidium.
Conclusions: ESRD is accompanied with substantial and multidirectional changes of trace elements blood levels. During researches has shown that in ESRD patients processes of trace elements accumulation are prevailing over elimination ones
The planarian Schmidtea mediterranea as a model system for the discovery and characterization of cell penetrating peptides and bioportides
The general utility of the planarian Schmidtea mediterranea, an organism with remarkable regenerative capacity, was investigated as a convenient threeâdimensional model to analyse the import of cellâpenetrating peptides (CPPs) and bioportides (bioactive CPPs) into complex tissues. The unpigmented planarian blastema, 3 days post head amputation, is a robust platform to assess the penetration of redâfluorescent CPPs into epithelial cells and deeper tissues. Three planarian proteins, Ovo, ZicA and Djeya, which collectively control head remodelling and eye regeneration following decapitation, are a convenient source of novel cationic CPP vectors. One example, Djeya1 (RKLAFRYRRIKELYNSYR), is a particularly efficient and seemingly inert CPP vector that could be further developed to assist the delivery of bioactive payloads across the plasma membrane of eukaryotic cells. Eye regeneration, following head amputation, was utilized in an effort to identify bioportides capable of influencing stem cellâdependent morphogenesis. These investigations identified the tetradecapeptide mastoparan (INLKALAALAKKIL) as a bioportide able to influence the gross morphology of head development. We conclude that, compared with cellular monolayers, the S. mediterranea system provides many advantages and will support the identification of bioportides able to selectively modify the biology of totipotent neoblasts and, presumably, other mammalian stem cell types
Firefly genomes illuminate parallel origins of bioluminescence in beetles
Fireflies and their luminous courtships have inspired centuries of scientific study. Today firefly luciferase is widely used in biotechnology, but the evolutionary origin of bioluminescence within beetles remains unclear. To shed light on this long-standing question, we sequenced the genomes of two firefly species that diverged over 100 million-years-ago: the North American Photinus pyralis and Japanese Aquatica lateralis. To compare bioluminescent origins, we also sequenced the genome of a related click beetle, the Caribbean Ignelater luminosus, with bioluminescent biochemistry near-identical to fireflies, but anatomically unique light organs, suggesting the intriguing hypothesis of parallel gains of bioluminescence. Our analyses support independent gains of bioluminescence in fireflies and click beetles, and provide new insights into the genes, chemical defenses, and symbionts that evolved alongside their luminous lifestyle
ChemInform Abstract: SYNTHESEN VON DI- UND TETRAHYDROPYRROLEN 11. MITT. DIE ALKOHOLYSE UND CYANIERUNG VON 2,3,3-TRIMETHYL-2-HYDROXY-5-PYRROLIDON UND SEINEN DERIVATEN
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