32 research outputs found
Some biochemical properties of guaiacol peroxidases as modified by salt stress in leaves of salt-tolerant and salt-sensitive safflower (Carthamus tinctorius L.cv.) cultivars
The kinetics properties of guaiacol peroxidase (GP) and its isozymic pattern, and lipid peroxidation product were comparatively analyzed in two varieties of safflower (cv. M-CC-190 as salt-tolerant and cv. IL-111 as salt-sensitive cultivars) under normal and different concentrations of NaCl. The pH profile of GP activity in leaves extract of two cultivars in control and salt stressed plants showed different pattern of pH dependency with three maxima peaks at pH 4.5, 6.5 and 8 in salt-tolerant cultivar and two maxima peaks at pH 4.5 and 6.5 in salt-sensitive cultivar. Comparison of catalytic efficiency for GP between two cultivars at respective pH, showed that, salt-tolerant cultivar in both control and salt stressed conditionhad higher catalytic efficiency than salt-susceptible cultivar. The GP activity on the gels revealed four and two isoforms of peroxidases in salt-tolerant and salt-sensitive cultivars, respectively. GPs increased their expression with higher levels of salinity. However, in salt-sensitive cultivar GPs expression exhibited threshold behavior, with increase expressions in isoenzymes up to a certain level of salinity (25 mM NaCl), followed by decrease to a level of expressions corresponding to the control groups. The levels of lipid peroxidation as indicated by thiobarbituric acid reactive substances (TBARS) were higher in the sensitive variety than the tolerant under control and NaCl salinity. The overall results obtained in this study suggest that, oxidative stress may play an important role in salt-stressedsafflower plants and that the greater protection of M-CC-190 leaves from salt-induced oxidative damage results, at least in part, through the increase of the GPs activity, catalytic efficiency and induction of specific isoenzymes (P1 and P4).Key words: Safflower, guaiacol peroxidase, kinetics, isoenzymes, salt stress
Feasibility studies for imaging ee annihilation with modular multi-strip detectors
Studies based on imaging the annihilation of the electron (e) and its
antiparticle positron (e) open up several interesting applications in
nuclear medicine and fundamental research. The annihilation process involves
both the direct conversion of ee into photons and the formation of
their atomically bound state, the positronium atom (Ps), which can be used as a
probe for fundamental studies. With the ability to produce large quantities of
Ps, manipulate them in long-lived Ps states, and image their annihilations
after a free fall or after passing through atomic interferometers, this purely
leptonic antimatter system can be used to perform inertial sensing studies in
view of a direct test of Einstein equivalence principle. It is envisioned that
modular multistrip detectors can be exploited as potential detection units for
this kind of studies. In this work, we report the results of the first
feasibility study performed on a e beamline using two detection modules
to evaluate their reconstruction performance and spatial resolution for imaging
ee annihilations and thus their applicability for gravitational
studies of Ps
Progress towards Every Newborn Action Plan (ENAP) implementation in Iran: obstacles and bottlenecks
Background: Neonatal mortality accounts for more than 47 of deaths among children under five globally but proper care at and around the time of birth could prevent about two-thirds of these deaths. The Every Newborn Action Plan (ENAP) offers a plan and vision to improve and achieve equitable and high-quality care for mothers and newborns. We applied the bottleneck analysis tool offered by ENAP to identify obstacles and bottlenecks hindering the scale-up of newborn care across seven health system building blocks. Methods: We applied the every newborn bottleneck analysis tool to identify obstacles hindering the scale-up of newborn care across seven health system building blocks. We used qualitative methods to collect data from five medical universities and their corresponding hospitals in three provinces. We also interviewed other national experts, key informants, and stakeholders in neonatal care. In addition, we reviewed and qualitatively analyzed the performance report of neonatal care and services from 16 medical universities around the country. Results: We identified many challenges and bottlenecks in the scale-up of newborn care in Iran. The major obstacles included but were not limited to the lack of a single leading and governing entity for newborn care, insufficient financial resources for neonatal care services, insufficient number of skilled health professionals, and inadequate patient transfer. Conclusions: To address identified bottlenecks in neonatal health care in Iran, some of our recommendations were as follows: establishing a single national authorizing and leading entity, allocating specific budget to newborn care, matching high-quality neonatal health care providers to the needs of all urban and rural areas, maintaining clear policies on the distribution of NICUs to minimize the need for patient transfer, and using the available and reliable private sector NICU ambulances for safe patient transfer. © 2021, The Author(s)
Optimisation of the event-based TOF filtered back-projection for online imaging in total-body J-PET
We perform a parametric study of the newly developed time-of-flight (TOF)
image reconstruction algorithm, proposed for the real-time imaging in
total-body Jagiellonian PET (J-PET) scanners. The asymmetric 3D filtering
kernel is applied at each most likely position of electron-positron
annihilation, estimated from the emissions of back-to-back -photons.
The optimisation of its parameters is studied using Monte Carlo simulations of
a 1-mm spherical source, NEMA IEC and XCAT phantoms inside the ideal J-PET
scanner. The combination of high-pass filters which included the TOF filtered
back-projection (FBP), resulted in spatial resolution, 1.5 higher in
the axial direction than for the conventional 3D FBP. For realistic -minute
scans of NEMA IEC and XCAT, which require a trade-off between the noise and
spatial resolution, the need for Gaussian TOF kernel components, coupled with
median post-filtering, is demonstrated. The best sets of 3D filter parameters
were obtained by the Nelder-Mead minimisation of the mean squared error between
the resulting and reference images. The approach allows training the
reconstruction algorithm for custom scans, using the IEC phantom, when the
temporal resolution is below 50 ps. The image quality parameters, estimated for
the best outcomes, were systematically better than for the non-TOF FBP
Testing CPT symmetry in ortho-positronium decays with positronium annihilation tomography
Charged lepton system symmetry under combined charge, parity, and time-reversal transformation (CPT) remains scarcely tested. Despite stringent quantum-electrodynamic limits, discrepancies in predictions for the electron–positron bound state (positronium atom) motivate further investigation, including fundamental symmetry tests. While CPT noninvariance effects could be manifested in non-vanishing angular correlations between final-state photons and spin of annihilating positronium, measurements were previously limited by knowledge of the latter. Here, we demonstrate tomographic reconstruction techniques applied to three-photon annihilations of ortho-positronium atoms to estimate their spin polarisation without magnetic field or polarised positronium source. We use a plastic-scintillator-based positron-emission-tomography scanner to record ortho-positronium (o-Ps) annihilations with single-event estimation of o-Ps spin and determine the complete spectrum of an angular correlation operator sensitive to CPT-violating effects. We find no violation at the precision level of 10−4, with an over threefold improvement on the previous measurement
From tests of discrete symmetries to medical imaging with J-PET detector
We present results on CPT symmetry tests in decays of positronium performed with the precision at the level of 10, and positronium images determined with the prototype of the J-PET tomograph. The first full-scale prototype apparatus consists of 192 plastic scintillator strips readout from both ends with vacuum tube photomultipliers. Signals produced by photomultipliers are probed in the amplitude domain and are digitized by FPGA-based readout boards in triggerless mode. In this contribution we report on the first two- and three-photon positronium images and tests of CPT symmetry in positronium decays
Flood hazard assessment and mapping in semi-arid piedmont areas: a case study in Beni Mellal, Morocco
Prevalence and Socio-Demographic Correlates of Mental Health Problems Among Iranian Health Sciences Students
Objective: The primary objective of the present study was to compare the mental health status of Iranian medical vs other health sciences students and to examine how demographic factors relate to their mental health problems. Methods: A total of 560 medical and other health sciences students (250 (44.6) males and 310 (55.4) females) were recruited from Iran University of Medical Sciences. Data were obtained by self-administered questionnaire, including questions on socio-demographic characteristics. The Beck Depression Inventory, Beck Anxiety Inventory, General Health Questionnaire, and WHO well-being index were used to assess mental health status of students. Results: Ten percent of students had BDI scores consistent with clinically significant depression (6.6 mild, 1.8 moderate, 1.6 severe), and 28.7 had BAI scores consistent with clinically significant anxiety (20.7 mild, 7.1 moderate, 0.9 severe). Kurdish students had an odds ratio (OR) of 2.71 (95 CL, 1.22�6.02) for mild to severe depression symptoms when compared to Persian students. The prevalence of distressed health sciences students and poor psychological well-being was 13.4 and 14.1, respectively. Maternal education gave an OR of 0.57 (0.35�0.93) for anxiety symptoms, after adjustment for all other factors. The possibility of general psychiatric morbidity was significantly lower in students who studied medicine (OR, 0.40 (0.21�0.71)). Being born in the capital city was associated with better psychological well-being (OR, 0.48 (0.26�0.86)). Conclusions: Ethnicity, birthplace, discipline, and maternal educational level were major determinants of mental health status among health sciences students. Further research should be undertaken to determine the prevalence of psychological disorders using more reliable diagnostic interview. © 2019, Academic Psychiatry
Determining Dimensions of Iranians’ Individual Social Health: A Qualitative Approach
Background: Social health is important to be assessed as a dimension of health. The aim of study was to determine domains and sub-domains of individual social health of Iranians.Methods: This study was carried out with a qualitative approach, using thematic content analysis. Twenty five experts participated in interviews, using individual semi-structured interviews between November 2010 and June 2011.This data supported with strong search.Results: Two main areas extracted from these interviews including social support and social function. The social support domain contained seventeen sub-areas, including social support at the time of disease; disability; daily life issues, etc. And the social function as second domain contained twelve sub-areas, including: financial aids to others; emotionally aids to others; participating in social groups, etc.Conclusion: We developed a conceptual framework for social health in the individual level in Iranian population. It makes preparations for providing a valid and reliable measurement scale for social health in next studies and evidence-based policy-making