Effects of confinement (110 and 240 days) on neuroendocrine stress response and changes of immune cells in men

2002 ◽  
Vol 92 (4) ◽  
pp. 1619-1627 ◽  
Author(s):  
A. Choukèr ◽  
L. Smith ◽  
F. Christ ◽  
I. Larina ◽  
I. Nichiporuk ◽  
...  
Keyword(s):  
Stress Test ◽  
Suppressor Cells ◽  
Delayed Type Hypersensitivity ◽  
Immunological Parameters ◽  
Enhanced Expression ◽  
Hypersensitivity Skin ◽  
Male Subjects ◽  
A Current ◽  
T Suppressor Cells

The aim of the study was to evaluate the effects of long-term confinement on stress-permissive neuroendocrine and immune responses in humans. Two groups of four male subjects were confined 240 days ( group 240) or 110 days ( group 110) in two space modules of 100 or 200 m3, respectively. During confinement, none of the volunteers developed psychic stress as could be examined and verified by a current stress test. However, in g roup 240 but not in group 110, the diurnal rhythm of cortisol secretion was slightly depressed and the urine excretion of norepinephrine significantly increased. The innate part of the immune system became activated as seen by a rise in the number of circulating granulocytes and the enhanced expression of β2-integrins. In contrast, the ratio of T-helper to T-suppressor cells decreased. All these effects, observed during confinement, were even more pronounced in both groups when values of endocrinological and immunological parameters were compared between before and 1 wk after the end of the confinement period. Hence, return to normal life exerts pronounced effects to a much higher degree, irrespective of how long or under which conditions individuals were confined. Because the delayed-type hypersensitivity skin reaction against recall antigens remained unaffected, it is to be presumed that confinement appears to induce distinct sympathoadrenergic activation and immunological changes but no clinically relevant immunosuppression.

Simulated microgravity, psychic stress, and immune cells in men: observations during 120-day 6° HDT

2001 ◽  
Vol 90 (5) ◽  
pp. 1736-1743 ◽  
Author(s):  
A. Choukèr ◽  
M. Thiel ◽  
V. Baranov ◽  
D. Meshkov ◽  
A. Kotov ◽  
...  
Keyword(s):  
Immune Cells ◽  
Polymorphonuclear Leukocytes ◽  
Nk Cell ◽  
Stress Test ◽  
Suppressor Cells ◽  
Psychological State ◽  
T Helper ◽  
Long Duration ◽  
A Current ◽  
T Suppressor Cells

Because 6° head-down tilt (HDT) is an established method to mimic low gravity on earth, the aim of the present study was to determine the effects of 120-day HDT on psychic stress and peripheral blood immune cells in six healthy male volunteers. Psychological state was assessed by a current stress test, and cortisol was measured in saliva. During HDT, all volunteers developed psychic stress, and the diurnal rhythm of cortisol secretion was significantly altered. In addition, urine excretion of dopamine and norepinephrine increased. The innate part of the immune response was activated, as evidenced by the increase in the expression of β2-integrins on polymorphonuclear leukocytes and a rise in the number of circulating natural killer (NK) cell lymphocytes. The ratio of T-helper to T-cytotoxic and T-suppressor cells decreased, whereas no changes in T and B lymphocytes were observed. Plasma levels of interleukin-6 increased significantly and returned to basal levels after the end of the HDT period. Thus 6° HDT appears to be a valid model to induce psychic stress and neuroendocrine-related changes in the immune system, changes that might also be encountered by astronauts and cosmonauts during long-duration spaceflights.

scholarly journals Robust Carbon-Stabilization of Few-Layer Black Phosphorus for Superior Oxygen Evolution Reaction

Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 695 ◽  
Author(s):  
Mengjie Zhang ◽  
Wenchang Zhu ◽  
Xingzhe Yang ◽  
Meng Feng ◽  
Hongbin Feng
Keyword(s):  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Black Phosphorus ◽  
Carbon Stabilization ◽  
High Durability ◽  
Carbon Coated ◽  
Alkaline Conditions ◽  
Doped Graphene ◽  
A Current

Few-layer exfoliated black phosphorus (Ex-BP) has attracted tremendous attention owing to its promising applications, including in electrocatalysis. However, it remains a challenge to directly use few-layer Ex-BP as oxygen-involved electrocatalyst because it is quite difficult to restrain structural degradation caused by spontaneous oxidation and keep it stable. Here, a robust carbon-stabilization strategy has been implemented to prepare carbon-coated Ex-BP/N-doped graphene nanosheet (Ex-BP/NGS@C) nanostructures at room temperature, which exhibit superior oxygen evolution reaction (OER) activity under alkaline conditions. Specifically, the as-synthesized Ex-BP/NGS@C hybrid presents a low overpotential of 257 mV at a current density of 10 mA cm−2 with a small Tafel slope of 52 mV dec−1 and shows high durability after long-term testing.

scholarly journals Canada as a Case Study for Balanced Presentation to Address Controversy on Emission Reduction Policies

2021 ◽  
Vol 13 (14) ◽  
pp. 7909
Author(s):  
Robert V. Parsons
Keyword(s):  
Emission Reduction ◽  
Environmental Issues ◽  
Trade Show ◽  
Quantitative Metrics ◽  
Carbon Taxation ◽  
Canadian Provinces ◽  
Method Analysis ◽  
A Current

Controversy is common on environmental issues, with carbon taxation in Canada a current example. This paper uses Canada as a case study for analysis based around balanced presentation, a technique developed some time ago, yet largely forgotten. Using the method, analysis is shifted away from the point of controversy to a broader quantitative question, with comparative data employed from official government sources. Simple quantitative analysis is applied to evaluate emission trends of individual Canadian provinces, with quantitative metrics to identify and confirm the application of relevant emission reduction policies by individual jurisdictions. From 2005 through 2019, three provinces show consistent downward emission trends, two show consistent upward trends, and the remaining five have no trends, showing relatively “flat” profiles. The results clarify, in terms of diverse emission reduction policies, where successes have occurred, and where deficiencies or ambiguities have existed. Neither carbon taxation nor related cap-and-trade show any association with long-term reductions in overall emissions. One policy does stand out as being associated with long-term reductions, namely grid decarbonization. The results suggest a possible need within Canada to rethink emission reduction policies. The method may be relevant as a model for other countries to consider as well.

scholarly journals Photoconduction of Polar and Nonpolar Cuts of Undoped Sr0.61Ba0.39Nb2O6 Single Crystals

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 780
Author(s):  
Elke Beyreuther ◽  
Julius Ratzenberger ◽  
Matthias Roeper ◽  
Benjamin Kirbus ◽  
Michael Rüsing ◽  
...  
Keyword(s):  
Electrical Measurement ◽  
Excitation Wavelength ◽  
Trap States ◽  
Strontium Barium Niobate ◽  
Strontium Barium ◽  
Current Voltage ◽  
History Of ◽  
A Current ◽  
Complex Manner

In the last two decades, variably doped strontium barium niobate (SBN) has attracted a lot of scientific interest mainly due to its specific non-linear optical response. Comparably, the parental compound, i.e., undoped SBN, appears to be less studied so far. Here, two different cuts of single-crystalline nominally pure strontium barium niobate in the composition Sr0.61Ba0.39Nb2O6 (SBN61) are comprehensively studied and analyzed with regard to their photoconductive responses. We present conductance measurements under systematically varied illumination conditions along either the polar z-axis or perpendicular to it (x-cut). Apart from a pronounced photoconductance (PC) already under daylight and a large effect upon super-bandgap illumination in general, we observe (i) distinct spectral features when sweeping the excitation wavelength over the sub-bandgap region as then discussed in the context of deep and shallow trap states, (ii) extremely slow long-term relaxation for both light-on and light-off transients in the range of hours and days, (iii) a critical dependence of the photoresponse on the pre-illumination history of the sample, and (iv) a current–voltage hysteresis depending on both the illumination and the electrical-measurement conditions in a complex manner.

Manipulation of autoimmune diseases with T-suppressor cells: lessons from experimental SLE and EAE

1993 ◽  
Vol 36 (2) ◽  
pp. 109-116 ◽  
Author(s):  
Yehuda Shoenfeld ◽  
Miri Blank ◽  
Rina Aharoni ◽  
Dvora Teitelbaum ◽  
Ruth Arnon
Keyword(s):  
Autoimmune Diseases ◽  
Suppressor Cells ◽  
T Suppressor Cells

scholarly journals Identification of lymphocyte subpopulations with a polymethine dye.

1988 ◽  
Vol 36 (7) ◽  
pp. 711-715 ◽  
Author(s):  
L Kass
Keyword(s):  
Suppressor Cells ◽  
Buffy Coat ◽  
Lymphocyte Subpopulations ◽  
Rapid Screening ◽  
T Helper ◽  
Yellow Orange ◽  
A Cell ◽  
Health And Disease ◽  
T Suppressor Cells ◽  
Polymethine Dye

Using the polymethine dye p-ethoxyphenyl-p-aminostyryl-1,3,3-trimethyl-3H-indolium chloride as an aqueous stain applied to specimens of peripheral blood or buffy coat fixed in FAA fixative, differential coloration of leukocytes was achieved using darkfield illumination. Neutrophils stained dark maroon and contained green granules, eosinophils contained bright blue granules, basophils revealed yellow and pink granules, and monocytes stained green with green and yellow vacuoles. In studies of purified lymphocyte subpopulations obtained in a cell sorter, T-helper cells stained red, T-suppressor cells were yellow orange, B-cells appeared yellow and often contained yellow annular structures in the cytoplasm, and natural killer (NK) cells stained green and contained large green granules. As a rapid screening technique for identification of T-helper and T-suppressor cells and their ratios in health and disease, the new polymethine stain may complement the more complex monoclonal antibody techniques for identification of these cells.

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