scholarly journals Importance of nonlinearities to quantify mechanical pulmonary stress under dynamic conditions: stress index and SLICE method

Critical Care ◽  
2007 ◽  
Vol 11 (Suppl 2) ◽  
pp. P181
Author(s):  
C Stahl ◽  
H Meißner ◽  
D Steinmann ◽  
G Mols ◽  
C Micelli ◽  
...  
Keyword(s):  
Stress Index ◽  
Dynamic Conditions ◽  
Slice Method ◽  
Pulmonary Stress

Calculation of structure images of crystalline defects

1978 ◽  
Vol 36 (1) ◽  
pp. 282-283
Author(s):  
M.A. O'Keefe ◽  
Sumio Iijima
Keyword(s):  
Diffuse Scattering ◽  
Computing Time ◽  
Continuous Distribution ◽  
Sampling Interval ◽  
Reciprocal Space ◽  
Objective Lens ◽  
Lattice Images ◽  
Slice Method ◽  
Space Cell ◽  
Beam Lattice

We have extended the multi-slice method of computating many-beam lattice images of perfect crystals to calculations for imperfect crystals using the artificial superlattice approach. Electron waves scattered from faulted regions of crystals are distributed continuously in reciprocal space, and all these waves interact dynamically with each other to give diffuse scattering patterns.In the computation, this continuous distribution can be sampled only at a finite number of regularly spaced points in reciprocal space, and thus finer sampling gives an improved approximation. The larger cell also allows us to defocus the objective lens further before adjacent defect images overlap, producing spurious computational Fourier images. However, smaller cells allow us to sample the direct space cell more finely; since the two-dimensional arrays in our program are limited to 128X128 and the sampling interval shoud be less than 1/2Å (and preferably only 1/4Å), superlattice sizes are limited to 40 to 60Å. Apart from finding a compromis superlattice cell size, computing time must be conserved.

Association between calcitriol and paricalcitol with oxidative stress in patients with hemodialysis

2020 ◽  
pp. 1-8
Author(s):  
Hasan Haci Yeter ◽  
Berfu Korucu ◽  
Elif Burcu Bali ◽  
Ulver Derici
Keyword(s):  
Oxidative Stress ◽  
Vitamin D ◽  
Antioxidant Status ◽  
Total Antioxidant Status ◽  
Stress Index ◽  
Total Oxidant Status ◽  
Vitamin D Analog ◽  
Total Antioxidant ◽  
Oxidant Status ◽  
And Oxidative Stress

Abstract. Background: The pathophysiological basis of chronic kidney disease and its complications, including cardiovascular disease, are associated with chronic inflammation and oxidative stress. We investigated the effects of active vitamin D (calcitriol) and synthetic vitamin D analog (paricalcitol) on oxidative stress in hemodialysis patients. Methods: This cross-sectional study was composed of 83 patients with a minimum hemodialysis vintage of one year. Patients with a history of any infection, malignancy, and chronic inflammatory disease were excluded. Oxidative markers (total oxidant and antioxidant status) and inflammation markers (C-reactive protein and interleukin-6) were analyzed. Results: A total of 47% (39/83) patients were using active or analog vitamin D. Total antioxidant status was significantly higher in patients with using active or analog vitamin D than those who did not use (p = 0.006). Whereas, total oxidant status and oxidative stress index were significantly higher in patients with not using vitamin D when compared with the patients who were using vitamin D preparation (p = 0.005 and p = 0.004, respectively). On the other hand, total antioxidant status, total oxidant status, and oxidative stress index were similar between patients who used active vitamin D or vitamin D analog (p = 0.6; p = 0.4 and p = 0.7, respectively). Conclusion: The use of active or selective vitamin D analog in these patients decreases total oxidant status and increases total antioxidant status. Also, paricalcitol is as effective as calcitriol in decreasing total oxidant status and increasing total antioxidant status in patients with chronic kidney disease.

Anforderungen, Entscheidungsfreiräume und Stress im Studium

Diagnostica ◽  
2019 ◽  
Vol 65 (2) ◽  
pp. 63-74 ◽  
Author(s):  
Laura I. Schmidt ◽  
Fabian Scheiter ◽  
Andreas Neubauer ◽  
Monika Sieverding
Keyword(s):  
Perceived Stress ◽  
Soziale Arbeit ◽  
Stress Index ◽  
Job Content Questionnaire ◽  
Reliabilität Und Validität ◽  
Körperliche Beschwerden ◽  
Job Content ◽  
Demand Control

Zusammenfassung. Mit dem Demand-Control-Modell und dem dazugehörigen Job Content Questionnaire (JCQ) existiert im Arbeitsumfeld ein bewährtes Modell zur Vorhersage physischer und psychischer Gesundheitsrisiken. Um diese auch unter Studierenden theoriegeleitet vorhersagen zu können, passten wir den JCQ auf den Hochschulkontext an und untersuchten mittels unseres Fragebogens zu strukturellen Belastungen und Ressourcen im Studium (StrukStud) den Erklärungsbeitrag hinsichtlich Stresserleben und Wohlbefinden. In 4 Studien mit insgesamt 732 Studierenden (Psychologie, Lehramt, Soziale Arbeit, Wirtschaftsrecht und Erziehung & Bildung) wurden die Demand-Control-Dimensionen (StrukStud), Stresserleben (Heidelberger Stress-Index HEI-STRESS & Perceived Stress Questionnaire) und weitere Referenzkonstrukte wie Studienzufriedenheit und körperliche Beschwerden erfasst. Befunde zur Reliabilität und Validität werden vorgestellt. Die Ergebnisse belegen die psychometrische Qualität des StrukStud sowie dessen Potenzial zur Erklärung von Stress im Studium. Mit dem StrukStud liegt für den deutschsprachigen Raum erstmals ein ökonomisches Selbsteinschätzungsinstrument zur Erfassung von psychologischen Anforderungen und Entscheidungsfreiräumen im Studium vor.

Measurement Invariance Analysis of the Parental Stress Index

2019 ◽  
Vol 35 (6) ◽  
pp. 771-778 ◽  
Author(s):  
Bernhard Piskernik ◽  
Barbara Supper ◽  
Lieselotte Ahnert
Keyword(s):  
Measurement Invariance ◽  
Parental Stress ◽  
Stress Index ◽  
Factor Analyses ◽  
Confirmatory Factor Analyses ◽  
Mean Values ◽  
Confirmatory Factor ◽  
Structural Invariance ◽  
Parent Domain ◽  
Structural Levels

Abstract. While parenting research continues to compare similarities and differences in mothers’ and fathers’ behaviors based on mean values on the respective dimensions, measurement invariance as a prerequisite for these comparisons has seldom been assured. The present study thus subjected the well-known Parenting Stress Index (PSI), widely used in models of family functioning, to a rigorous measurement invariance analysis based on ( N = 214) Austrian couples with children younger than 3 years of age. We evaluated configural, metric, scalar, and uniqueness invariance on item and subscale levels, and tested for structural invariance of means and variances of the PSI parent and child domain by second-order confirmatory factor analyses. As a result, only measurement differences on the scalar levels affected the factor scores, though negligibly. On the structural levels, no differences were found on the PSI child domain across parents, but on the PSI parent domain, mothers reported more stress.

Perceived Stress Index

2005 ◽  
Author(s):  
Noreen Goldman ◽  
Dana A. Glei ◽  
Christopher Seplaki ◽  
I-Wen Liu ◽  
Maxine Weinstein
Keyword(s):  
Perceived Stress ◽  
Stress Index

Student Nurse Stress Index Scale--Chinese Version

2019 ◽  
Author(s):  
Lina Guo ◽  
Martyn C. Jones ◽  
Yanjin Liu ◽  
Suyuan Yv ◽  
Yiru Zhu ◽  
...  
Keyword(s):  
Chinese Version ◽  
Student Nurse ◽  
Stress Index ◽  
Student Nurse Stress Index

Neutrophil Derived Cathepsin G Induces Potentially Thrombogenic Changes in Human Endothelial Cells: a Scanning Electron Microscopy Study in Static and Dynamic Conditions

1994 ◽  
Vol 72 (01) ◽  
pp. 140-145 ◽  
Author(s):  
Valeri Kolpakov ◽  
Maria Cristina D'Adamo ◽  
Lorena Salvatore ◽  
Concetta Amore ◽  
Alexander Mironov ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Extracellular Matrix ◽  
Endothelial Cells ◽  
Thrombus Formation ◽  
Cathepsin G ◽  
Arterial Segment ◽  
Dynamic Conditions ◽  
Activated Neutrophils ◽  
Scanning Electron

SummaryActivated neutrophils may promote thrombus formation by releasing proteases which may activate platelets, impair the fibrinolytic balance and injure the endothelial monolayer.We have investigated the morphological correlates of damage induced by activated neutrophils on the vascular wall, in particular the vascular injury induced by released cathepsin G in both static and dynamic conditions.Human umbilical vein endothelial cells were studied both in a cell culture system and in a model of perfused umbilical veins. At scanning electron microscopy, progressive alterations of the cell monolayer resulted in cell contraction, disruption of the intercellular contacts, formation of gaps and cell detachment.Contraction was associated with shape change of the endothelial cells, that appeared star-like, while the underlying extracellular matrix, a potentially thrombogenic surface, was exposed. Comparable cellular response was observed in an “in vivo” model of perfused rat arterial segment. Interestingly, cathepsin G was active at lower concentrations in perfused vessels than in culture systems. Restoration of blood flow in the arterial segment previously damaged by cathepsin G caused adhesion and spreading of platelets on the surface of the exposed extracellular matrix. The subsequent deposition of a fibrin network among adherent platelets, could be at least partially ascribed to the inhibition by cathepsin G of the vascular fibrinolytic potential.This study supports the suggestion that the release of cathepsin G by activated neutrophils, f.i. during inflammation, may contribute to thrombus formation by inducing extensive vascular damage.

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