52 research outputs found
Monitoring of the reflectors of ESA's Planck telescope by close-range photogrammetry
The Planck mission of the European Space Agency (ESA) is designed to image the anisotropies of the Cosmic Background Radiation Field over the whole sky. Planck's objective is to analyze, with the highest accuracy ever achieved, the remnants of the radiation that filled the universe immediately after the Big Bang, which we observe today as the cosmic microwave background. To achieve this aim well-manufactured reflectors are used as parts of the Planck telescope receiving system. The system consists of the Secondary and Primary Reflectors which are sections of two different ellipsoids of revolution with diameters of 1.1 and 1.9 meters. Deformations of the reflectors which influence the optical parameters and the gain of receiving signals are investigated in vacuum and at temperatures down to 95K, using close-range photogrammetric techniques. We have designed an optimal close-range photogrammetric network by heuristic simulation for the Primary and Secondary Reflectors with a mean relative precision better than 1:1,000,000 and 1:400,000, respectively, to achieve the requested accuracies. Special considerations have been taken into account in different steps of design, such as the determinability of additional parameters under the given network configuration, datum definition, reliability and precision issues as well as workspace limits and propagating errors from different sources of errors. A least squares best-fit ellipsoid was developed to determine the optical parameters of the reflector. We present our procedure and the results of processing the photogrammetric measurements of the Flight Models of the Primary and Secondary Reflectors which were executed by Thales Alenia Space France under ESA-ESTEC contract in vacuum and at very low temperature
Proton-pump inhibitors and risk of renal disease
Proton pump inhibitors (PPIs) are one group of drugs that inhibit gastric acid secretion by binding irreversibly to the gastric proton pump. This paper aimed to review the impact of PPIs on kidney function and structure by presenting the updated information in this regard. In this review, we summarize in electronic databases including Google Scholar, EMBASE, MEDLINE, Scopus and EBSCO during the period of 1980 to 2017 by using the following search terms; proton-pump inhibitors, kidney injury, renal diseases, adverse events of protonpump inhibitors, acute interstitial nephritis, renal injury and chronic kidney disease. The PPIs are known as one group of drugs that are well tolerated in healthy subjects and where serious harms are rare. The some reports reveal that long-term administration of PPIs is associated with adverse effects such as: increasing the incident risk of kidney injury, hyper-secretion of gastric acid after their withdrawal, bone fracture, decreased levels of blood magnesium, interaction with metabolism of antiplatelet agents, increased risk of enteric infections and community-acquired pneumonia.
Proton-pump inhibitors and risk of renal disease (PDF Download Available). Available from: https://www.researchgate.net/publication/316284636_Proton-pump_inhibitors_and_risk_of_renal_disease [accessed Nov 08 2017]
Investigating the relationship between physical and mental health among operating room personnel
BACKGROUND: Communities have been involved in adverse health factors at any point in time and have sought to improve community health and quality of life (QOL). The purpose of this study is to investigate the condition of physical and mental health and the relation between the two variables with each other in the operating room of hospitals in Shiraz, Iran.METHODS: This was a cross-sectional study performed on 192 staff of operating rooms of Shiraz University of Medical Sciences. The data for the study were collected through the General Health Questionnaire (GHQ) and the General Lifestyle Questionnaire (GLQ).RESULTS: Analyzing the results, the mean total scores of lifestyle and mental health were 333.93 ± 42.91 and 39.24 ± 12.59, respectively. In addition, the correlation coefficient between the total lifestyle and mental health scores was -0.411.CONCLUSION: Since the operating room is the most sensitive part of any hospital and the so-called heart of the hospital, special attention should be paid to staff working in this department, as any disruption to the operating room staff is not only harmful to them. Rather, it has many detrimental effects on patients and the health system. Therefore, given the stressful environment of the operating room, managers should promote operating room programs focused on reducing stress and by conducting classes and training sessions, improve the mental and physical health of the operating room personnel
A closed-loop supply chain network in the edible oil industry using a novel robust stochastic-possibilistic programming
In recent years, the complexity of the environment, the intense competition of organizations, the pressure of governments on producers to manage waste products, environmental pressures and most importantly, the benefits of recycling products have added to the importance of designing a closed loop supply chain network. Also, the existence of inherent uncertainties in the input parameters is another important factor that the lack of attention them can affect the strategic, tactical and operational decisions of organizations. Given these reasons, this research aims to design a multi-product and multi period closed loop supply chain network model in uncertainty conditions. To this aim, first a mixed-integer linear programming model is proposed to minimize supply chain costs. Then, for coping with hybrid uncertain parameters effectively, randomness and epistemic uncertainty, a novel robust stochastic-possibilistic programming (RSPP) approach is proposed. Furthermore, several varieties of RSPP models are developed and their differences, weaknesses, strengths and the most suitable conditions for being used are discussed. Finally, usefulness and applicability of the RSPP model are tested via the real case study in an edible oil industry
Anticonvulsant effect of minocycline on pentylenetetrazole-induced seizure in mice: involvement of nitric oxide and N-methyl-D-aspartate receptor
Anticonvulsant effects of minocycline have been explored recently. This study was designed to examine the anticonvulsant
effect of acute administration of minocycline on pentylenetetrazole-induced seizures in mouse considering the possible role of the
nitric oxide/N-methyl-D-aspartate (NMDA) pathway. We induced seizure using intravenous administration of pentylenetetrazole. Our
results showed that acute administration of minocycline increased the seizure threshold. Furthermore, co-administration of subeffective
doses of the nonselective nitric oxide synthase (NOS) inhibitor NG-L-arginine methyl ester (10 mg/kg) and the neuronal NOS
inhibitor 7-nitroindazole (40 mg/kg) enhanced the anticonvulsant effect of subeffective doses of minocycline (40 mg/kg). We found
that inducible NOS inhibitor aminoguanidine (100 mg/kg) had no effect on the antiseizure effect of minocycline. Moreover, L-arginine
(60 mg/kg), as a NOS substrate, reduced the anticonvulsant effect of minocycline. We also demonstrated that pretreatment with the
NMDAreceptor antagonists ketamine (0.5 mg/kg) and MK-801 (0.05 mg/kg) increased the anticonvulsant effect of subeffective doses of
minocycline. Results showed that minocycline significantly decreased the hippocampal nitrite level. Furthermore, co-administration
of a neuronal NOS inhibitor like NMDA receptor antagonists augmented the effect of minocycline on the hippocampal nitrite level.
In conclusion, we revealed that anticonvulsant effect of minocycline might be, at least in part, due to a decline in constitutive
hippocampal nitric oxide activity as well as inhibition of NMDA receptors
Morphine modulates the effects of histamine H1 and H3 receptors on seizure susceptibility in pentylenetetrazole-induced seizure model of mice
Histamine regulates release of neurotransmitters such as dopamine, serotonin, gamma-aminobutyric
acid (GABA), glutamate and also is involved in several functions in central nervous system (CNS). It has
been shown that histamine participates in disorders like seizure. It has been well documented that
morphine dose-dependently induces anti or proconvulsant effects. In the current study, we firstly
showed that morphine (1 mg/kg) exerts anticonvulsant effects which significantly reversed by naltrexone
administration. Secondly, we determined seizure threshold for H1 and H3 receptors agonists and
antagonists in mouse model of pentylenetetrazole (PTZ)-induced clonic seizures. Our results showed that
activation of H1 receptors by 2-(2-Pyridyl)-ethylamine exerts anticonvulsant properties while inhibition
of H1 receptors by pyrilamine maleate induced proconvulsant effects. Furthermore, we showed that
immepip dihydrobromide, a H3 receptor agonist, increased seizure susceptibility to PTZ whereas thioperamide,
a H3 receptor antagonist increased seizure threshold. We also revealed that pretreatment with
morphine potently reversed the effects of histaminergic system on seizure threshold suggesting the
involvement of opioid system in alteration of seizure threshold by histaminergic drug
Experiencing neonatal maternal separation increased the seizure threshold in adult male mice: Involvement of the opioid system
Experiencing early-life stress has been considered as a potent risk factor for the development of many of brain
disorders, including seizures. Intervening mechanisms through which neonatal maternal separation (MS) alters
the seizure susceptibility in adulthood have not been well studied. In the current study, by applying 180 min of
MS stress (PND 2–14), we determined the seizure susceptibility and considered the role of the opioid system.
Maternal separation increased the seizure threshold, and administration of anticonvulsant/proconvulsant
doses of morphine (1 and 30 mg/kg, respectively) reversed the impact of MS. Using tail flick and hot plate
tests, we exposed animals to 30 min Restraint stress (RS) and found that MS decreased the pain threshold,
suggesting the hyporesponsiveness of the opioid system. These results supported the abnormal seizure activity
observed in the MS mice and suggested that abnormalities in the opioid system following MS alter seizure
susceptibility in later life
Protective effects of gabapentin against the seizure susceptibility and comorbid behavioral abnormalities in the early socially isolated mice
Adolescence is a pivotal period of brain development during lifespan, which is sensitive to stress exposure. Early social isolation stress (SIS) is known to provoke a variety of psychiatric comorbidities as well as seizure risk. Psychiatric comorbidities present challenging dilemmas for treatment and management in people with seizure disorders. In this study, we aimed to investigate whether gabapentin (GBP) as an anti-epileptic drug is able to alleviate the seizure activity as well as comorbid behavioral abnormalities in socially isolated mice. Results showed that early SIS induced proconvulsant effects along with depressive, aggressive and anxiety-like behaviors. Whereas the administration of both acute and chronic GBP at sub-effective doses produced no alterations in the behavioral profile of socially conditioned counterparts the same treatments effectively reversed the seizure susceptibility to pentylenetetrazole and behavioral deficits in isolated mice. Results of the study indicate that 1) Early SIS could be considered as an animal model of psychosocial stress to investigate the psychiatric comorbidities in seizure disorders, 2) Chronic administration of low dose GBP prevented the shaping of behavioral abnormalities in adulthood, 3) Chronic administration of low dose GBP produced no negative behavioral effects in socially conditioned mice suggesting the safety of the drug, 4) Gabapentin at low doses may be considered as an agent for management of epilepsy in individuals with psychiatric comorbidities
NMDA receptor antagonists attenuate the proconvulsant effect of juvenile social isolation in male mice
Experiencing psychosocial stress inearly life, suchas social isolationstress (SIS), is knowntohavenegative
enduring effects on the development of the brain and behavior. In addition to anxiety and depressive-like
behaviors, we previously showed that juvenile SIS increases susceptibility to pentylenetetrazole (PTZ)-
induced seizures in mice through enhancing the nitrergic system activity in the hippocampus. In this
study, we investigated the possible involvement of N-methyl-d-aspartate (NMDA) receptors in proconvulsant
effects of juvenile SIS. Applying 4 weeks of SIS to juvenile male mice at postnatal day 21–23, we
observed an increased susceptibility to PTZ as well as anxiety and depressive-like behaviors in adult mice.
Intraperitoneal (i.p.) administration of NMDA receptor antagonists, MK-801 (0.05 mg/kg) and ketamine
(0.5 mg/kg), reversed the proconvulsant effects of SIS in Isolated (and not social) housed animals. Coadministration
of non-effective doses of nitric oxide synthase (NOS) inhibitors, 7NI (25 mg/kg) and
L-NAME (10 mg/kg), with NMDA receptor antagonists, MK-801 (0.01 mg/kg) and ketamine (0.1 mg/kg)
attenuated the proconvulsant effects of juvenile SIS only in isolated housed mice. Also, using real time
RT-PCR, we showed that hippocampal upregulation of NR2B subunit of NMDA receptor may play a critical
role in proconvulsant effects of juvenile SIS by dysregulation of NMDA/NO pathway. In conclusion,
results of present study revealed that experiencing SIS during adolescence predisposes the co-occurrence
of seizure disorders with psychiatric comorbidities and also, alteration of NMDA receptor structure and
function in hippocampus plays a role in proconvulsant effects of juvenile SIS through enhancing the
NMDA/NO pathwa
Lithium attenuates the proconvulsant effect of adolescent social isolation stress via involvement of the nitrergic system
In this study, we tested whether acute administration of lithium mitigates the deleterious effect of adolescent social
isolation stress (SIS) on seizure susceptibility. In comparison with socially conditioned (SC) mice, isolated
conditioned (IC) mice exhibited an increase in seizure susceptibility to pentylenetetrazole. Acute administration
of lithium (10 mg/kg) reversed the proconvulsant effect of SIS in IC mice, but this effect was not observed in SC
mice. Coadministration of subthreshold doses of lithium (3 mg/kg) with nitric oxide synthase (NOS) inhibitors
reversed the effect of SIS on seizure susceptibility and decreased hippocampal nitrite levels in IC animals. In
addition, a subthreshold dose of a nitric oxide precursor reduced the protective effect of lithium on seizure susceptibility
and increased nitrite levels in the hippocampus of IC mice. These results suggest that lithium exerts a
protective influence against the proconvulsant effect of adolescent SIS via a nitrergic system that includes activation
of neuronal NOS in the hippocampus
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