1,122 research outputs found
A Unifying look at d-dimensional periodicities ans space covering
We propose a formal characterization of d-dimensional periodicities. We show first that any periodic pattern has a canonical decomposition and a minimal generator, generalizing the 1D property. This allows to classify the d-dimensional patterns in d+1 classes, according to their periodicities, each class having subclasses. A full classification of the coverings of a 2-dimensional space by a pattern follows. These results have important algorithmic issues in pattern matching. First, the covering classification allows an efficient use of the now classical duel paradigm. Second, d-dimensional pattern matching complexity is intrinsically different for each class
Metformin and cimetidine: Physiologically based pharmacokinetic modelling to investigate transporter mediated drug–drug interactions
Metformin is used as a probe for OCT2 mediated transport when investigating possible DDIs with new chemical
entities. The aim of the current study was to investigate the ability of physiologically-based pharmacokinetic
(PBPK) models to simulate the effects of OCT and MATE inhibition by cimetidine on metformin kinetics. PBPK
models were developed, incorporating mechanistic kidney and liver sub-models for metformin (OCT and
MATE substrate) and a mechanistic kidney sub-model for cimetidine. The models were used to simulate inhibition
of the MATE1, MATE2-K, OCT1 and OCT2 mediated transport of metformin by cimetidine. Assuming competitive
inhibition and using cimetidine Ki values determined in vitro, the predicted metformin AUC ratio was 1.0
compared to an observed value of 1.46. The observed AUC ratio could only be recovered with this model when
the cimetidine Ki for OCT2 was decreased 1000-fold or the Ki's for both OCT1 and OCT2 were decreased 500-
fold. An alternative description of metformin renal transport by OCT1 and OCT2, incorporating electrochemical
modulation of the rate of metformin uptake together with 8–18-fold decreases in cimetidine Ki's for OCTs and
MATEs, allowed recovery of the extent of the observed effect of cimetidine on metformin AUC. While the final
PBPK model has limitations, it demonstrates the benefit of allowing for the complexities of passive permeability
combined with active cellular uptake modulated by an electrochemical gradient and active efflu
Effect of mother's infant massage on neonatal weight and perceived self-efficacy of mothers with low birth weight infants
Introduction: Weight is the most important growth factor in newborns and perceived self-efficacy is known as an effective factor weigh gaining. The aim of this study was to determine the effect of mother's infant massage on neonatal weight and perceived self-efficacy of mothers with low birth weight infants. Materials and Methods: 80 infants were divided into intervention and control groups in this qusiexperimental study in neonatal intensive care unit. 40 low-birth weight infants received massage by their mother for 60 days, 15 minutes a day, and only normal care was taken in the control group. At the end of the study, weight gain and self-efficacy scores were analyzed standard statisctical methods. Results: The results showed that there was a significant difference between the mean weight changes in the intervention group (2120.88± 385.26) and control (1760.88 ± 220.31) at the tenth day of birth and two months (P = 0.001). The results of independent t-test showed a significant increase in self-efficacy scores and its dimensions in the two intervention groups compared to the control group (P<0.001). Conclusion: Low-birth-weight infant massage improves weight gain and promotes perceived self-efficacy in mothers. Due to the low cost of this method, it is suggested to teach massage techniques as one of the essential training during discharge in newborns. © 2020, Semnan University of Medical Sciences. All rights reserved
Study of possibilities of aquaculture activities in the Gorgan Bay
The Gorgan golf is one of unique ecosystem in Iran which has plenty of known and unknown ecological values. Different agents threaten this ecosystem such as severe exploitation of natural resource on human behalf. This must be restricted using an accepted programs otherwise the ecological situation of the Gorgan golf will be worsen and finally to be died. In these study biological circumstances of the golf has been investigated in order to evaluate its ecological capacity to develop a sustainable aquaculture activities. This study started from Sep, 2010 and lasted to Oct, 2011. On the basis of the results from this study, and with considerations of all environmental conditions some aquatic organisms recommended for aquaculture purposes such as common carp (Cyprinus carpio), Caspian sea salmon (Salmo truta caspius), sturgeons stellate (Acipenser stellatus), Persian sturgeon (Acipenser persicus) and the great sturgeon (Huso huso). The farming procedure recommended as pen culture. In this study, the suitable surface of each pen, required information over each cultured species, suitable density and the amount of catch for each species have been determined. The amount of Nitrogen and Phosphorous originated from feeding and also secreted from fish species as the pollution index entered into the farming sites. The authorized amount of pollution factors for production and aquaculture in the Gorgan golf has been determined. In addition the study over the structure type for farming and also the suitable site for pen culture with consider to the facilities and conditions have been done. With notice to the above, with developing the aquaculture in this ecosystem, local workers will be run and plenty of capital will be invested and finally this will tend to the great revenues by producing of favor protein. This industry is able to change the region to a most important sites to produce aquatic organisms
Functional interleukin-17 receptor A is expressed in central nervous system glia and upregulated in experimental autoimmune encephalomyelitis
<p>Abstract</p> <p>Background</p> <p>Interleukin-17A (IL-17A) is the founding member of a novel family of inflammatory cytokines that plays a critical role in the pathogenesis of many autoimmune diseases, including multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE). IL-17A signals through its receptor, IL-17RA, which is expressed in many peripheral tissues; however, expression of IL-17RA in the central nervous system (CNS) and its role in CNS inflammation are not well understood.</p> <p>Methods</p> <p>EAE was induced in C57Bl/6 mice by immunization with myelin oligodendroglial glycoprotein. IL-17RA expression in the CNS was compared between control and EAE mice using RT-PCR, in situ hybridization, and immunohistochemistry. Cell-type specific expression was examined in isolated astrocytic and microglial cell cultures. Cytokine and chemokine production was measured in IL-17A treated cultures to evaluate the functional status of IL-17RA.</p> <p>Results</p> <p>Here we report increased IL-17RA expression in the CNS of mice with EAE, and constitutive expression of functional IL-17RA in mouse CNS tissue. Specifically, astrocytes and microglia express IL-17RA <it>in vitro</it>, and IL-17A treatment induces biological responses in these cells, including significant upregulation of MCP-1, MCP-5, MIP-2 and KC chemokine secretion. Exogenous IL-17A does not significantly alter the expression of IL-17RA in glial cells, suggesting that upregulation of chemokines by glial cells is due to IL-17A signaling through constitutively expressed IL-17RA.</p> <p>Conclusion</p> <p>IL-17RA expression is significantly increased in the CNS of mice with EAE compared to healthy mice, suggesting that IL-17RA signaling in glial cells can play an important role in autoimmune inflammation of the CNS and may be a potential pathway to target for therapeutic interventions.</p
Comparative sustainability study of energy storage technologies using data envelopment analysis
The transition to energy systems with a high share of renewable energy depends on the availability of technologies that can connect the physical distances or bridge the time differences between the energy supply and demand points. This study focuses on energy storage technologies due to their expected role in liberating the energy sector from fossil fuels and facilitating the penetration of intermittent renewable sources. The performance of 27 energy storage alternatives is compared considering sustainability aspects by means of data envelopment analysis. To this end, storage alternatives are first classified into two clusters: fast-response and long-term. The levelized cost of energy, energy and water consumption, global warming potential, and employment are common indicators considered for both clusters, while energy density is used only for fast-response technologies, where it plays a key role in technology selection. Flywheel reveals the highest efficiency between all the fast-response technologies, while green ammonia powered with solar energy ranks first for long-term energy storage. An uncertainty analysis is incorporated to discuss the reliability of the results. Overall, results obtained, and guidelines provided can be helpful for both decision-making and research and development purposes. For the former, we identify the most appealing energy storage options to be promoted, while for the latter, we report quantitative improvement targets that would make inefficient technologies competitive if attained. This contribution paves the way for more comprehensive studies in the context of energy storage by presenting a powerful framework for comparing options according to multiple sustainability indicators
A Prospective Study on Risk Factors for Acute Kidney Injury and All-Cause Mortality in Hospitalized COVID-19 Patients From Tehran (Iran)
Background: Several reports suggested that acute kidney injury (AKI) is a relatively common occurrence in hospitalized COVID-19 patients, but its prevalence is inconsistently reported across different populations. Moreover, it is unknown whether AKI results from a direct infection of the kidney by SARS-CoV-2 or it is a consequence of the physiologic disturbances and therapies used to treat COVID-19. We aimed to estimate the prevalence of AKI since it varies by geographical settings, time periods, and populations studied and to investigate whether clinical information and laboratory findings collected at hospital admission might influence AKI incidence (and mortality) in a particular point in time during hospitalization for COVID-19.
Methods: Herein we conducted a prospective longitudinal study investigating the prevalence of AKI and associated factors in 997 COVID-19 patients admitted to the Baqiyatallah general hospital of Tehran (Iran), collecting both clinical information and several dates (of: birth; hospital admission; AKI onset; ICU admission; hospital discharge; death). In order to examine how the clinical factors influenced AKI incidence and all-cause mortality during hospitalization, survival analysis using the Cox proportional-hazard models was adopted. Two separate multiple Cox regression models were fitted for each outcome (AKI and death).
Results: In this group of hospitalized COVID-19 patients, the prevalence of AKI was 28.5% and the mortality rate was 19.3%. AKI incidence was significantly enhanced by diabetes, hyperkalemia, higher levels of WBC count, and blood urea nitrogen (BUN). COVID-19 patients more likely to die over the course of their hospitalization were those presenting a joint association between ICU admission with either severe COVID-19 or even mild/moderate COVID-19, hypokalemia, and higher levels of BUN, WBC, and LDH measured at hospital admission. Diabetes and comorbidities did not increase the mortality risk among these hospitalized COVID-19 patients.
Conclusions: Since the majority of patients developed AKI after ICU referral and 40% of them were admitted to ICU within 2 days since hospital admission, these patients may have been already in critical clinical conditions at admission, despite being affected by a mild/moderate form of COVID-19, suggesting the need of early monitoring of these patients for the onset of eventual systemic complications
Long-term and recent changes in sea level in the Falkland Islands
Mean sea level measurements made at Port Louis in the Falkland Islands in 1981-2, 1984 and 2009, together with values from the nearby permanent tide gauge at Port Stanley, have been compared to measurements made at Port Louis in 1842 by James Clark Ross. The long-term rate of change of sea level is estimated to have been +0.75 ± 0.35 mm/year between 1842 and the early 1980s, after correction for air pressure effects and for vertical land movement due to Glacial Isostatic Adjustment (GIA). The 2009 Port Louis data set is of particular importance due to the availability of simultaneous information from Port Stanley. The data set has been employed in two ways, by providing a short recent estimate of mean sea level itself, and by enabling the effective combination of measurements at the two sites. The rate of sea level rise observed since 1992, when the modern Stanley gauge was installed, has been larger at 2.51 ± 0.58 mm/year, after correction for air pressure and GIA. This rate compares to a value of 2.79 ± 0.42 mm/year obtained from satellite altimetry in the region over the same period. Such a relatively recent acceleration in the rate of sea level rise is consistent with findings from other locations in the southern hemisphere and globall
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