Mechanisms for restraining and deploying a 50-kW solar array

Design and hardware of restraining and deploying mechanism for solar array of Mars flyby missio

Is Chytridiomycosis an Emerging Infectious Disease in Asia?

The disease chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis (Bd), has caused dramatic amphibian population declines and extinctions in Australia, Central and North America, and Europe. Bd is associated with >200 species extinctions of amphibians, but not all species that become infected are susceptible to the disease. Specifically, Bd has rapidly emerged in some areas of the world, such as in Australia, USA, and throughout Central and South America, causing population and species collapse. The mechanism behind the rapid global emergence of the disease is poorly understood, in part due to an incomplete picture of the global distribution of Bd. At present, there is a considerable amount of geographic bias in survey effort for Bd, with Asia being the most neglected continent. To date, Bd surveys have been published for few Asian countries, and infected amphibians have been reported only from Indonesia, South Korea, China and Japan. Thus far, there have been no substantiated reports of enigmatic or suspected disease-caused population declines of the kind that has been attributed to Bd in other areas. In order to gain a more detailed picture of the distribution of Bd in Asia, we undertook a widespread, opportunistic survey of over 3,000 amphibians for Bd throughout Asia and adjoining Papua New Guinea. Survey sites spanned 15 countries, approximately 36° latitude, 111° longitude, and over 2000 m in elevation. Bd prevalence was very low throughout our survey area (2.35% overall) and infected animals were not clumped as would be expected in epizootic events. This suggests that Bd is either newly emerging in Asia, endemic at low prevalence, or that some other ecological factor is preventing Bd from fully invading Asian amphibians. The current observed pattern in Asia differs from that in many other parts of the world

Clinical Guidelines of the Russian Society of Surgeons, the Russian Gastroenterological Association, the Association of Surgeons-Hepatologists and the Endoscopic Society “REndO” on Diagnostics and Treatment of Chronic Pancreatitis

Aim: to present modern methods of diagnosis and treatment of chronic pancreatitis for gastroenterologists, general practitioners and physicians.Chronic pancreatitis (CP) is a long-term inflammatory disease of the pancreas, manifested by irreversible morphological changes in the parenchyma and pancreatic ducts, which cause pain and/or persistent impairment of function. Current concept on the etiology of CP is reflected by the TIGAR-O classification. The criteria for establishing the diagnosis of CP include typical attacks of abdominal pain and/or clinical and laboratory signs of exocrine, endocrine insufficiency with the mandatory detection of characteristic morphological changes (calcifications in the parenchyma and pancreatic ductal stones, dilatation of the main pancreatic duct and its branches). CT, MRCP, and pancreatobiliary endosonography are recommended as the methods of choice to verify the diagnosis of CP. Conservative treatment of patients with CP is provided for symptom relief and prevention of complications. Individual cases with severe non-interactable abdominal pain, as well as a complicated course of the disease (development of ductal hypertension due to main pancreatic duct stones or strictures, obstructive jaundice caused by compression of the common bile duct, symptomatic postnecrotic cysts, portal hypertension due to compression of the portal vein or thrombosis of the splenic vein, persistent duodenal obstruction, pseudoaneurysm of the celiac trunk basin and the superior mesenteric artery) serve as an indication for endoscopic or surgical treatment. The Guidelines set out modern approaches to the diagnosis, conservative, endoscopic and surgical treatment of CP, and the prevention of its complications.Conclusion. The implementation of clinical guidelines can contribute to the timely diagnosis and improve the quality of medical care for patients with chronic pancreatitis

La2Zr2O7/LaAlO3 composite prepared by mixing precipitated precursors: Evolution of its structure under sintering

For La2Zr2O7/LaAlO3 composite prepared by aging (100 °C/10 h) of the mixture of precipitated precursors of La-Zr-O and La-Al-O, evolution of its structural features after sintering in air in the range of 100–1300 °C was investigated by applying XRD, HRTEM, FTIR, Raman and UV–Vis spectroscopies, 27Al MAS NMR and 139La NMR. The initial composite forms a highly dispersed and disordered structure retaining considerable concentrations of residual anions (anions from the initial salts, water molecules and hydrogen bound hydroxyls) due to basic properties of La cations. Stepwise removal of these anions by calcinations results in the crystallization of La2(Al)O2CO3 at 500 °C with complete disordering of the system after heating at 700 °C. These transitions are accompanied by appearance of AlO4 polyhedra. The La-Zr-O- containing phase appeared for the first time at 900 °C as fluorite-like ZrO2 stabilized by La (Al) cations, and LaAlO3 (P2) phase is also observed along with admixtures of La2O3 and La10Al4O21. At 1100 °C fluorite-like ZrO2 converts into the La2Zr2O7 (P1) phase, and in the range of 1100–1300 °C mixed P1 and P2 oxides are the main phases. For P1 phase, structure becomes more ordered at higher sintering temperatures, while for P2 phase in composite the nanodomain structure is still observed in comparison with individual mixed oxide at 1300 °C. The molecular –scale features of domain boundaries in nanostructured La-Zr-O/La-Al-O composite as well as applied inexpensive method of its fabrication provide required bases for a broad practical application of this material for Thermal barrier coatings (TBCs). © 2020 Elsevier B.V