Probable role of plasma instabilities in anomalous high altitude luminosity observed in meteors and space-vehicles re-entries

2000 ◽  
Author(s):  
Andrei Ol'khovatov
Respirology ◽  
2010 ◽  
Vol 15 (4) ◽  
pp. 651-658 ◽  
Author(s):  
Tsering STOBDAN ◽  
Ram KUMAR ◽  
Ghulam MOHAMMAD ◽  
Tashi THINLAS ◽  
Tsering NORBOO ◽  
...  

1975 ◽  
Vol 37 (4) ◽  
pp. 532-540 ◽  
Author(s):  
Zenro IKEZAWA ◽  
Yo KAMEDA ◽  
Mitsuaki UCHIYAMA ◽  
Hiroshi NAKAJIMA ◽  
Toru BABA

2013 ◽  
pp. 23-25
Author(s):  
P. Faggioli ◽  
S. Finazzi ◽  
E. Vicenzi ◽  
L. Giani ◽  
M. Rondena ◽  
...  

BACKGROUND Scleroderma, when complicated with pulmonary hypertension (PHT), presents a worse prognosis; recently treatment with new drugs seems to offer good perspectives, especially in early diagnosis and treatment. The standard approach for diagnosing PHT consists in measurement of the pulmonary artery pressure (PAP) by means of echodoppler. AIM OF INVESTIGATION Aim of this work is evaluating the significance of the NT-proBNP parameter, matched to echodoppler, in diagnosing scleroderma PHT. MATERIALS AND METHODS Sixty (60) patients, who came to observation for progressive systemic sclerosis underwent echodoppler in order to measure the PAP (normal values up to 30 mmHg). NT-proBNP was determined on serum sample using ECLIA method by Modular E170 (Roche Diagnostics); manufacturer reference values for age and gender were used. Forty-three (43) patients underwent a further NT-proBNP sampling 5 days later in order to assess parameter stability. RESULTS PHT and non- PHT patients showed statistically different (p < 0,001) medians (126 vs 69 pg/ml). No pathologic values of NT-proBNP were measured in the group with PAP < 30 mmHg, while 27% of cases who had PAP between 30 and 40 showed pathologic concentrations. The positivity ratio increases to 57% in patients showing PAP > 40 mmHg. No relevant correlation (r = 0,2) was found between PAP and NT-proBNP. Mean average between the two sampling groups was 31%. CONCLUSIONS In scleroderma patients, combination of NT-proBNP and PAP seems to improve the diagnosis of pulmonary hypertension, especially in presence of borderline pulmonary pressure values. We therefore propose the biochemical observation of NT-proBNP when PAP is > 30 mmHg and in monitoring the evolution of the pathology.


Hypertension ◽  
2013 ◽  
Vol 61 (4) ◽  
pp. 793-799 ◽  
Author(s):  
Paolo Salvi ◽  
Miriam Revera ◽  
Andrea Faini ◽  
Andrea Giuliano ◽  
Francesca Gregorini ◽  
...  

2013 ◽  
Vol 31 (2) ◽  
pp. 251-261 ◽  
Author(s):  
J. De Keyser ◽  
M. Echim

Abstract. Strong localized high-altitude auroral electric fields, such as those observed by Cluster, are often associated with magnetospheric interfaces. The type of high-altitude electric field profile (monopolar, bipolar, or more complicated) depends on the properties of the plasmas on either side of the interface, as well as on the total electric potential difference across the structure. The present paper explores the role of this cross-field electric potential difference in the situation where the interface is a tangential discontinuity. A self-consistent Vlasov description is used to determine the equilibrium configuration for different values of the transverse potential difference. A major observation is that there exist limits to the potential difference, beyond which no equilibrium configuration of the interface can be sustained. It is further demonstrated how the plasma densities and temperatures affect the type of electric field profile in the transition, with monopolar electric fields appearing primarily when the temperature contrast is large. These findings strongly support the observed association of monopolar fields with the plasma sheet boundary. The role of shear flow tangent to the interface is also examined.


2001 ◽  
Vol 4 (4) ◽  
pp. 323-331 ◽  
Author(s):  
S.N. Singh ◽  
P. Vats ◽  
Radhey Shyam ◽  
S. Suri ◽  
M.M.L. Kumria ◽  
...  
Keyword(s):  

2007 ◽  
Vol 292 (3) ◽  
pp. L678-L684 ◽  
Author(s):  
Yuansheng Gao ◽  
Ada D. Portugal ◽  
Sewite Negash ◽  
Weilin Zhou ◽  
Lawrence D. Longo ◽  
...  

An increase in Rho kinase (ROCK) activity is implicated in chronic hypoxia-induced pulmonary hypertension. In the present study, we determined the role of ROCKs in cGMP-dependent protein kinase (PKG)-mediated pulmonary vasodilation of fetal lambs exposed to chronic hypoxia. Fourth generation pulmonary arteries were isolated from near-term fetuses (∼140 days of gestation) delivered from ewes exposed to chronic high altitude hypoxia for ∼110 days and from control ewes. In vessels constricted to endothelin-1, 8-bromoguanosine-cGMP (8-Br-cGMP) caused a smaller relaxation in chronically hypoxic (CH) vessels compared with controls. Rp-8-Br-PET-cGMPS, a PKG inhibitor, attenuated relaxation to 8-Br-cGMP in control vessels to a greater extent than in CH vessels. Y-27632, a ROCK inhibitor, significantly potentiated 8-Br-cGMP-induced relaxation of CH vessels and had only a minor effect in control vessels. The expression of PKG was increased but was not accompanied with an increase in the activity of the enzyme in CH vessels. The expression of type II ROCK and activity of ROCKs were increased in CH vessels. The phosphorylation of threonine (Thr)696 and Thr850 of the regulatory subunit MYPT1 of myosin light chain phosphatase was inhibited by 8-Br-cGMP to a lesser extent in CH vessels than in controls. The difference was eliminated by Y-27632. These results suggest that chronic hypoxia in utero attenuates PKG-mediated relaxation in pulmonary arteries, partly due to inhibition of PKG activity and partly due to enhanced ROCK activity. Increased ROCK activity may inhibit PKG action through increased phosphorylation of MYPT1 at Thr696 and Thr850.


Biochimie ◽  
2019 ◽  
Vol 156 ◽  
pp. 138-147 ◽  
Author(s):  
Pooja Chaudhary ◽  
Yogendra Kumar Sharma ◽  
Shivani Sharma ◽  
Som Nath Singh ◽  
Geetha Suryakumar

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