133 research outputs found

    Surface Tension of Seawater

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    New measurements and a reference correlation for the surface tension of seawater at atmospheric pressure are presented in this paper. Surface tension of seawater was measured across a salinity range of 20 ⩽ S ⩽ 131 g/kg and a temperature range of 1 ⩽ t ⩽ 92 °C at atmospheric pressure using the Wilhelmy plate method. The uncertainty within measurements varied from 0.18 to 0.37 mN/m with the average uncertainty being 0.22 mN/m. The experimental procedures were validated with tests conducted on ACS reagent grade water and aqueous sodium chloride solutions. Literature data and present measurements were evaluated and a reference correlation was developed expressing surface tension of seawater as a function of temperature and salinity. The average absolute percentage deviation between measurements and the correlation was 0.19% while the maximum deviation was 0.60%.Center for Clean Water and Clean Energy at MIT and KFUPM (Project R13-CW-10

    Magnetic resonance spectroscopy of hippocampal and striatal neurometabolites in experimental PTSD rat modeling

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    The spectrum of the metabolites in the dorsal region of the hippocampus and striatum was studied using the method of 1H magnetic resonance spectroscopy at experimental modeling of the posttraumatic stress disorder syndrome (PTSD) in rats. PTSD was reproduced by exposure of the cat cue to rats daily along 10 day by 10 minutes at once. The anxiety level of animals was estimated 12 days later after the end of the experimental series of stress. Based on the anxiety index, the rats were divided into 3 phenotypes. The animals with an anxiety index > 0.8 (group 1) had lower plasma corticosterone compared with rats form the control group. In animals with an anxiety index in the range 0.7–0.8 (group 2), an elevated corticosterone level was noted. The rats with an anxiety index < 0.7 (group 3) had a lower plasma corticosterone level compared with animals from the control group. Rats of group 2 were characterized by an increased level of GABA in the hippocampus compared with controls. In the remaining groups, the percentages of GABA in the hippocampus and striatum did not differ significantly from the control. The distribution of NAA differed form that of GABA. The highest level of NAA was found in the striatum for rats from group 1, whereas NAA in animals form groups 1 or 3 did not differ from the control. The NAA level in the hippocampus was similar between all groups, including the control. The results obtained indicate that multiple exposures to psychological stress associated with the sense of proximity of a natural enemy in some animals cause an anxiolytic reaction. These animals are characterized by a stable corticosterone level and a stable level of neurometabolites in the studied structures of the brain. For rats with the highest level of anxiety, a lowered level of corticosterone with a constant level of neurometabolites in the hippocampus and striatum is characteristic. And only in rats with an intermediate level of anxiety, synchronization was observed between the increase in plasma corticosterone and the increase in hippocampal GABA content. The results obtained are in good agreement with the ideas of the protective action of glucocorticoids under PTSD manifested in  restraining violations of the psycho-physiological status. The mate rials allow the neurobiological mechanisms of the protective action of glucocorticoids to be detailed

    Determination of ππ\pi\pi scattering lengths from measurement of π+π\pi^+\pi^- atom lifetime

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    The DIRAC experiment at CERN has achieved a sizeable production of π+π\pi^+\pi^- atoms and has significantly improved the precision on its lifetime determination. From a sample of 21227 atomic pairs, a 4% measurement of the S-wave ππ\pi\pi scattering length difference a0a2=(.0.25330.0078+0.0080stat.0.0073+0.0078syst)Mπ+1|a_0-a_2| = (.0.2533^{+0.0080}_{-0.0078}|_\mathrm{stat}.{}^{+0.0078}_{-0.0073}|_\mathrm{syst})M_{\pi^+}^{-1} has been attained, providing an important test of Chiral Perturbation Theory.Comment: 6 pages, 6 figure

    Offensive behavior, striatal glutamate metabolites, and limbic–hypothalamic–pituitary–adrenal responses to stress in chronic anxiety

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    Variations in anxiety-related behavior are associated with individual allostatic set-points in chronically stressed rats. Actively offensive rats with the externalizing indicators of sniffling and climbing the stimulus and material tearing during 10 days of predator scent stress had reduced plasma corticosterone, increased striatal glutamate metabolites, and increased adrenal 11-dehydrocorticosterone content compared to passively defensive rats with the internalizing indicators of freezing and grooming, as well as to controls without any behavioral changes. These findings suggest that rats that display active offensive activity in response to stress develop anxiety associated with decreased allostatic set-points and increased resistance to stress. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.The Russian Science Foundation (grant № 17-15-013418) supported this study. This was supported in part by the contracts of the Ministry of Education and Science of the Russian Federation with South Ural State University (17.7255.2017/8.9) and Institute of Immunology and Physiology (AAAA-A18-118020690020-1). The work was furthermore supported by institutional funds from the State University of New York (SUNY) Upstate Medical University. This work is part of the TransCampus project between TU Dresden and King’s College London and was partially supported by the U.S. Department of Veterans Affairs (5101CX001219) and the U.S. Department of Defense (W81XWH-16-1-0773)

    Anxiety and neurometabolite levels in the hippocampus and amygdala after prolonged exposure to predator-scent stress

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    Here, to study the relationship between anxiety levels with changes in the neurometabolic profile in the hippocampus and amygdala, an experimental predator stress model was reproduced in which Sprague-Dawley rats were exposed to cat urine for 10 minutes on a daily basis for 10 days. At the time of presentation of the stimulus, an online survey of behavioral reactions was conducted. Fear, aggressiveness, avoidance of stimulus and grooming were recorded. Fourteen days after the completion of the last stress exposure, the total level of anxiety was determined in the test of the“cross maze”. Using the method of in vivo NMR spectroscopy, the content of neurometabolites was determined in the hippocampus and in the amygdala. According to the peculiarities of behavioral reactions to a stressor, animals were retrospectively divided into two phenotypes. The first phenotype used a passive behavioral strategy, and the second phenotype was active. In animals of the first phenotype, the indicators of anxiety behavior remained at the control level. In animals of the second phenotype, a decrease in anxiety was observed. Animals of the second phenotype showed elevated levels of lactate in the hippocampus compared to animals of the first phenotype, and the lowest N-acetylaspartate levels significantly differed from those in the control and the first phenotype animals. In the amygdala, in animals of the second phenotype, the content of taurine is sharply reduced in comparison with those in the control and the animals of the first phenotype. Thus, the results obtained indicate a relationship of post-stress changes in anxiety, with the peculiarities of the behavioral reactions presented at the moment of the immediate action of the stressor. Among the hippocampal and amygdala neurometabolites, the most informative for the characterization of the anxiolytic action of the predator stress are identified

    Research action drug with immunomodulating and anti-oxidant effect in the complex therapy of experimental reproduction corneal conjunctival xerosis

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    The article shows the dynamics of clinical manifestations of corneal conjunctival xerosis and lacrimal fluid parameters of production on the experimental model of the experimental animals (rabbits) under general anesthesia, with playback corneal conjunctival xerosis the combined use derinat, emoxipine and accompanied by traditional therapy of postoperative transient corneal conjunctival xerosis. It was revealed that this scheme increases lacrimal glands function, as well as reduces the inflammatory manifestations, contributes to inflammatory complications and antioxidant activity of lacrimal fluid during therapy of corneal conjunctival xerosis.В статье представлена динамика клинических проявлений роговично-конъюнктивального ксероза и показателей продукции слезной жидкости экспериментальной модели животных (кроликов) с воспроизведенным роговично-конъюнктивальным ксерозом в условиях общей анестезии при сочетанном применении стиллавита, дерината и эмоксипина в сопровождении традиционной терапии роговично-конъюнктивального ксероза. Выявлено, что указанная схема повышает функцию слезообразования, антиоксидантную активность слезной жидкости, а также уменьшает воспалительные проявления роговично-конъюнктивального ксероза

    ОПЫТ УСПЕШНОГО ПРИМЕНЕНИЯ ВАКУУМНОЙ ТЕРАПИИ В ЛЕЧЕНИИ НЕСОСТОЯТЕЛЬНОСТИ КУЛЬТИ ЖЕЛУДКА ПОСЛЕ ЛАПАРОСКОПИЧЕСКОЙ ПРОДОЛЬНОЙ РЕЗЕКЦИИ: КЛИНИЧЕСКОЕ НАБЛЮДЕНИЕ

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    Gastric leak is the most dangerous postoperative complication of laparoscopic sleeve gastrectomy. Traditional surgical treatment options and endoscopic stent placement are not always successful. Negative Pressure Wound Therapy (NPWT) has shown itself like a new successful and feasible treatment option for leaks of different etiology after gastro-esophageal surgery.The initial body mass index (BMI) of the patient was 46 and co-morbidity was represented: arterial hypertension, type 2 diabetes and dyslipidemia. NPWT was initiated in 14 days after laparoscopic sleeve gastrectomy. The abdominal part of the system were changed 3 times for14 days. The patient was discharged from the hospital in 14 days after the secondary sutures to the wound. No relevant complications related to the procedure were observed during the course of the vacuum therapy. It combines defect closure, effective drainage and allows doing a periodic inspection of the wound cavity. NPWT is a successful, safety and effective treatment option for the leaks after laparoscopic sleeve gastrectomy Несостоятельность культи желудка является наиболее опасным послеоперационным осложнением лапароскопической продольной резекции желудка. Традиционные варианты хирургического лечения и эндоскопическая установка стентов не всегда успешны. Терапия отрицательным давлением (NPWT) показала, что это новый возможный эффективный метод лечения несостоятельности различной этиологии после операций на желудке и пищеводе.Исходный индекс массы тела пациентки составлял 46 кг/м2 , а сопутствующие заболевания были представлены артериальной гипертензией, сахарным диабетом 2-го типа, дислипидемией. Терапия отрицательным давлением была начата через 14 суток после лапароскопической продольной резекции желудка. В течение 14 дней было произведено 3 смены абдоминальной части системы. Через 14 дней после наложения вторичных швов на рану пациентка была выписана из стационара. За время применения вакуум-терапии не наблюдалось никаких осложнений, связанных с соответствующей методикой. Она сочетает в себе закрытие дефектов и эффективное дренирование, а также позволяет проводить периодический осмотр полости раны. NPWT – успешный, безопасный и эффективный способ лечения несостоятельностей после лапароскопической продольной резекции желудка.

    DIRAC Experiment and Test of Low-Energy QCD

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    The low-energy QCD predictions to be tested by the DIRAC experiment are revised. The experimental method, the setup characteristics and capabilities, along with first experimental results are reported. Preliminary analysis shows good detector performance: alignment error via Λ\Lambda mass measurement mΛ=1115.6MeV/c2m_\Lambda = 1115.6 MeV/c^2 with σ=0.92MeV/c2\sigma = 0.92 MeV/c^2, pπp \pi^- relative momentum resolution σQ2.7MeV/c\sigma_Q \approx 2.7 MeV/c, and evidence for $\pi^
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