403 research outputs found

    Urban Hypothermia and Hyperglycemia in the Elderly

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    From December 1993 to March 1999 we treated 18 elderly patients aged 66–87 years, suffering from urban hypothermia: 11 women and 7 men. Ten patients suffered from moderate hypothermia (rectal temperature 32–35 °C), and eight from severe hypothermia (rectal temperature<32 °C). Regarding consciousness, in the group suffering from moderate hypothermia, 3 were somnolent and 6 in various degrees of comatose states. In the group suffering from severe hypothermia, 3 patients were somnolent or soporous and 5 in comatose states of various degrees. Values of arterial blood pressure in the group with moderate hypothermia was normal in one, in 3 arterial hypotension was observed and 6 were in a state of shock. In the group with severe hypothermia, 3 presented arterial hypotension and 5 were in a state of shock. In the group with moderate hypothermia the blood glucose level was elevated in six: 9.3–10.2–10.7–17.9–21.3–99.0, and in one patient the blood glucose level was low: 2.3 mmol/L, in correlation with hypoglycemic coma. In the group with severe hypothermia in all eight patients the values were elevated: 6.7–7.4–7.6–8.7–9.1–11.2–12.4–17.9 mmol/L

    Aspects of fouling in case of heat exchangers with polluted gas

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    Paper presented at the 8th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Mauritius, 11-13 July, 2011.This paper presents and discusses various aspects of fouling in case of heavily polluted flue gas (and/or off-gas) coming especially from incinerators/waste-to-energy systems. A long-term experience and know-how from this area as well as continuing research and development brings new insights into manufacturing of equipment and their operating. Polluted off-gas causes high propensity to fouling and necessity of consequent cleaning. In some cases, it is not possible to utilize a conventional approach. Introductory part of the paper provides a description of various types of units for thermal processing of wastes (including sludge and contaminated biomass). Fouling is classified according to various cases of industrial applications connected with easy/difficult cleaning. It is shown how fouling can influence geometry of heat exchangers and their selection. In the following part, several industrial cases are shown taking into account aspects like: • solid particles (ash and flying ash) in the gas, and adapting design according to their concentration; • species contained in flue gas which can chemically react and create fouling deposits on heat transfer surfaces; • potential corrosion between the fouling layer and heat transfer surface caused by local temperature decrease. The above aspects are clearly illustrated through industrial applications as follows: • heat recovery system of unit for the thermal treatment of sludge coming from pulp and paper production; • boiler systems in incineration plants and chemical industry plants. There are various methods to reduce fouling. We have utilized very efficient approach combining intuitive design and sophisticated tools based on CFD (Computational Fluid Dynamics). However, fouling cannot be eliminated completely therefore various efficient methods (mostly tailor-made ones) are utilized (like common mechanical cleaning, air guns, controlled local explosion) for cleaning of surfaces. There is also an effort to develop a mathematical model for fouling prediction, and selection of the most economically acceptable systems connected with current research and development in the field. However, it is difficult to validate the models. Fouling in the field described in the paper is in fact a “never ending story”.pm201

    Spin dynamics of wave packets evolving with the Dirac Hamiltonian in atoms with high Z

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    The motion of circular WP for one electron in central Coulomb field with high Z is calculated. The WP is defined in terms of solutions of the Dirac equation in order to take into account all possible relevant effects in particular the spin-orbit potential. A time scale is defined within which spin dynamics must be taken into account mainly in the atoms with high Z. Within this time scale there exists a mechanism of collapses and revivals of the spin already shown by the authors for harmonic oscillator potential and called the 'spin-orbit pendulum'. However this effect has not the exact periodicity of the simpler model, but the WP's spatial motion is nevertheless quite similar.Comment: 17 pages, 9 figures, LaTeX2e, uses IOP style files (included). Title changed, one reference adde

    Recurrent DNMT3A R882 Mutations in Chinese Patients with Acute Myeloid Leukemia and Myelodysplastic Syndrome

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    Somatic mutations of DNMT3A gene have recently been reported in acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). We examined the entire coding sequences of DNMT3A gene by high-resolution melting analysis and sequencing in Chinese patients with myeloid malignancies. R882 mutations were found in 12/182 AML and in 4/51 MDS, but not in either 79 chronic myeloid leukemia (CML), or 57 myeloproliferative neoplasms (MPNs), or 4 chronic monomyelocytic leukemia. No other DNMT3A mutations were detected in all patients. R882 mutations were associated with old age and more frequently present in monoblastic leukemia (M4 and M5, 7/52) compared to other subtypes (5/130). Furthermore, 14/16 (86.6%) R882 mutations were observed in patients with normal karyotypes. The overall survival of mutated MDS patients was shorter than those without mutation (median 9 and 25 months, respectively). We conclude that DNMT3A R882 mutations are recurrent molecular aberrations in AML and MDS, and may be an adverse prognostic event in MDS

    Postoperative Fever: The Potential Relationship with Prognosis in Node Negative Breast Cancer Patients

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    Background: Postoperative fever may serve as an indirect sign to reflect the alterations of the host milieu caused by surgery. It still remains open to investigation whether postoperative fever has a bearing on prognosis in patients with lymph node negative breast cancers. Methods: We performed a retrospective study of 883 female unilateral patients with lymph node negative breast cancer. Fever was defined as an oral temperature $38 in one week postoperation. Survival curves were performed with Kaplan-Meier method, and annual relapse hazard was estimated by hazard function. Findings: The fever patients were older than those without fever (P,0.0001). Hypertensive patients had a propensity for fever after surgery (P = 0.011). A statistically significant difference was yielded in the incidence of fever among HR+/ERBB2-, ERBB2+, HR-/ERBB2- subgroups (P = 0.012). In the univariate survival analysis, we observed postoperative fever patients were more likely to recur than those without fever (P = 0.0027). The Cox proportional hazards regression analysis showed that postoperative fever (P = 0.044, RR = 1.89, 95%CI 1.02–3.52) as well as the HR/ERBB2 subgroups (P = 0.013, HR = 1.60, 95%CI 1.09–2.31) was an independent prognostic factor for relapse-free survival. Conclusion: Postoperative fever may contribute to relapse in node negative breast cancer patients, which suggests that changes in host milieu related to fever might accelerate the growth of micro-metastatic foci. It may be more precise t

    A wake-active locomotion circuit depolarizes a sleep-active neuron to switch on sleep

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    Sleep-active neurons depolarize during sleep to suppress wakefulness circuits. Wake-active wake-promoting neurons in turn shut down sleep-active neurons, thus forming a bipartite flip-flop switch. However, how sleep is switched on is unclear because it is not known how wakefulness is translated into sleep-active neuron depolarization when the system is set to sleep. Using optogenetics in Caenorhabditis elegans, we solved the presynaptic circuit for depolarization of the sleep-active RIS neuron during developmentally regulated sleep, also known as lethargus. Surprisingly, we found that RIS activation requires neurons that have known roles in wakefulness and locomotion behavior. The RIM interneurons-which are active during and can induce reverse locomotion-play a complex role and can act as inhibitors of RIS when they are strongly depolarized and as activators of RIS when they are modestly depolarized. The PVC command interneurons, which are known to promote forward locomotion during wakefulness, act as major activators of RIS. The properties of these locomotion neurons are modulated during lethargus. The RIMs become less excitable. The PVCs become resistant to inhibition and have an increased capacity to activate RIS. Separate activation of neither the PVCs nor the RIMs appears to be sufficient for sleep induction; instead, our data suggest that they act in concert to activate RIS. Forward and reverse circuit activity is normally mutually exclusive. Our data suggest that RIS may be activated at the transition between forward and reverse locomotion states, perhaps when both forward (PVC) and reverse (including RIM) circuit activity overlap. While RIS is not strongly activated outside of lethargus, altered activity of the locomotion interneurons during lethargus favors strong RIS activation and thus sleep. The control of sleep-active neurons by locomotion circuits suggests that sleep control may have evolved from locomotion control. The flip-flop sleep switch in C. elegans thus requires an additional component, wake-active sleep-promoting neurons that translate wakefulness into the depolarization of a sleep-active neuron when the worm is sleepy. Wake-active sleep-promoting circuits may also be required for sleep state switching in other animals, including in mammals

    The Central Clock Neurons Regulate Lipid Storage in Drosophila

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    A proper balance of lipid breakdown and synthesis is essential for achieving energy homeostasis as alterations in either of these processes can lead to pathological states such as obesity. The regulation of lipid metabolism is quite complex with multiple signals integrated to control overall triglyceride levels in metabolic tissues. Based upon studies demonstrating effects of the circadian clock on metabolism, we sought to determine if the central clock cells in the Drosophila brain contribute to lipid levels in the fat body, the main nutrient storage organ of the fly. Here, we show that altering the function of the Drosophila central clock neurons leads to an increase in fat body triglycerides. We also show that although triglyceride levels are not affected by age, they are increased by expression of the amyloid-beta protein in central clock neurons. The effect on lipid storage seems to be independent of circadian clock output as changes in triglycerides are not always observed in genetic manipulations that result in altered locomotor rhythms. These data demonstrate that the activity of the central clock neurons is necessary for proper lipid storage

    AMPK Regulates Circadian Rhythms in a Tissue- and Isoform-Specific Manner

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    AMP protein kinase (AMPK) plays an important role in food intake and energy metabolism, which are synchronized to the light-dark cycle. In vitro, AMPK affects the circadian rhythm by regulating at least two clock components, CKIα and CRY1, via direct phosphorylation. However, it is not known whether the catalytic activity of AMPK actually regulates circadian rhythm in vivo.THE CATALYTIC SUBUNIT OF AMPK HAS TWO ISOFORMS: α1 and α2. We investigate the circadian rhythm of behavior, physiology and gene expression in AMPKα1-/- and AMPKα2-/- mice. We found that both α1-/- and α2-/- mice are able to maintain a circadian rhythm of activity in dark-dark (DD) cycle, but α1-/- mice have a shorter circadian period whereas α2-/- mice showed a tendency toward a slightly longer circadian period. Furthermore, the circadian rhythm of body temperature was dampened in α1-/- mice, but not in α2-/- mice. The circadian pattern of core clock gene expression was severely disrupted in fat in α1-/- mice, but it was severely disrupted in the heart and skeletal muscle of α2-/- mice. Interestingly, other genes that showed circadian pattern of expression were dysreguated in both α1-/- and α2-/- mice. The circadian rhythm of nicotinamide phosphoryl-transferase (NAMPT) activity, which converts nicotinamide (NAM) to NAD+, is an important regulator of the circadian clock. We found that the NAMPT rhythm was absent in AMPK-deficient tissues and cells.This study demonstrates that the catalytic activity of AMPK regulates circadian rhythm of behavior, energy metabolism and gene expression in isoform- and tissue-specific manners
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