Influence of the nature of the sterol on the behavior of palmitic acid/sterol mixtures and their derived liposomes

AbstractThe phase behavior of mixtures formed with palmitic acid (PA) and one of the following sterols (dihydrocholesterol, ergosterol, 7-dehydrocholesterol, stigmasterol and stigmastanol), in a PA/sterol molar ratio of 3/7, has been characterized by IR and 2H NMR spectroscopy at different pH. Our study shows that it is possible to form liquid-ordered (lo) lamellar phases with these binary non-phospholipid mixtures. The characterization of alkyl chain dynamics of PA in these systems revealed the large ordering effect of the sterols. It was possible to extrude these systems, using standard extrusion techniques, to form large unilamellar vesicles (LUVs), except in the case of ergosterol-containing mixture. The resulting LUVs displayed a very limited passive permeability consistent with the high sterol concentration. In addition, the stability of these PA/sterol self-assembled bilayers was also found to be pH-sensitive, therefore, potentially useful as nanovectors. By examining different sterols, we could establish some correlations between the structure of these bilayers and their permeability properties. The structure of the side chain at C17 of the sterol appears to play a prime role in the mixing properties with fatty acid

Psychometric evaluation of Persian version of Diabetes Acceptance Scale (DAS)

Background: Acceptance of diabetes is a psychological adaptation to the potential limitations of the disease. Poor acceptance of diabetes impairs efective self-management of diabetes, leading to worsening metabolic control. This study aimed at determining the psychometric properties of the Persian version of the Diabetes Acceptance Scale. Methods: This cross-sectional methodological study was performed on diabetic patients in Iran in 2021. The ques tionnaire consisted of two parts: demographic characteristics and Diabetes Acceptance Scale. The questionnaire was translated into Persian through the forward–backward translation method. The face validity and content validity were performed qualitatively and quantitatively. Exploratory (n=200) and confrmatory (n=200) factor analysis were performed to evaluate the validity of the structure. Internal consistency and temporal stability were estimated to determine reliability. Results: Exploratory factor analysis on the polychoric correlation matrix obtained three factors: Rational dealing, Resentment and Avoidance, which explained 68.8% of the total DAS variance. Confrmatory factor analysis showed that the 3-fractor model had a good ft to a second independent data set. Finally, Ordinal Cronbach’s alpha coefcient was 0.96, 0.94 and 0.93, respectively for the Rational dealing, Resentment, and Avoidance factor. Also, using intraclass correlation coefcient, the stability of the instrument was 0.97. Conclusion: Based on the fndings of this study, the Persian version of DAS has sufcient validity and reliability to measure the admission of Iranian diabetic patientsinfo:eu-repo/semantics/publishedVersio

Exploring the Relationship among EFL Teachers’ Critical Thinking, Autonomy and Experience in Public and Private Schools

The research delved into the connection between English Language instructors’ critical thinking, autonomy, and teaching experience among some public and private instructors. Two different sets of instructors including some private institute and high school instructors were selected from two major cities in Khorasan Razavi, Iran. The results from Path Analysis indicated that all subcomponents of instructors’ thinking critically except deduction could significantly predict instructors’ independence. Moreover, experience more effectively and remarkably predicted their independence. Accordingly, from among the five subcomponents of instructors’ CT, four sub-constituents were predicated by experience. Nevertheless, assessment and evaluation could not be properly predicted by experience. Findings also indicated that thinking critically could rightly and moderately be related to autonomy whereas there was a positively weak association between thinking critically and experience. Accordingly, findings pointed to a sizeable distinction between the two EFL settings regarding instructors’ autonomous behavior with non-public EFL instructors being more self-sufficient, selfdirected, and self-reliant than their counterparts in public high schools. In the same vein, there was no substantial distinction between the two settings concerning thinking critically

Increased Glutathione Reductase Expression and Activity in Colorectal Cancer Tissue Samples: An Investigational Study in Mashhad, Iran

Background: Glutathione reductase is an important enzyme in oxidative metabolism that provides reduced glutathione from its oxidized form in the cells. The role of oxidative stress in tumor tissues has led us to investigate the gene expression and activity of this enzyme in tumor and adjacent resected margins of colorectal cancer tissues, one of the most common malignancies in humans. Methods: We conducted this study on 15 Iranian colorectal cancer patients. RNA was extracted from fresh colon tissues that included tumor and anatomically normal margin tissue. Expression of the glutathione reductase gene was determined using realtime PCR by the ΔΔCt relative quantification method. The gene expression results were standardized with glyceraldehyde 3-phosphate dehydrogenase as the endogenous reference gene. In addition, we measured enzyme activity of glutathione reductase with a commercial kit based on a colorimetric assay. Results: The tumor tissue had higher expression of glutathione reductase compared to the margin tissue (P=0.005). There was significantly greater glutathione reductase enzyme activity in the tumor tissue (116.9±34.31 nmol/min/ml) compared to the noncancerous adjacent tissues (76.7±36.85 nmol/min/ml; P=0.003). Conclusion: These data showed increased glutathione reductase expression and enzyme activity in colorectal tumor tissue. Given the key role of glutathione in synthesis of dNTPs for DNA repair with the glutaredoxin system, the increased glutathione reductase expression and activity might be a reflection of hyperactivity of this enzyme in DNA synthesis and the repair process in colorectal cancer cells

Caregiving consequences in cancer family caregivers: a narrative review of qualitative studies

BackgroundCancer is a significant public health issue, causing various challenges for individuals affected by it. As cancer progresses, patients often become dependent on others for support. Family caregivers and members play a crucial role in the recovery and rehabilitation of these patients. However, caregivers themselves face numerous challenges throughout the course of their family member’s illness. Exploring the experiences of family caregivers can inform long-term planning and supportive interventions to address their caregiving difficulties. This study reviews previous literature on caregiving outcomes.MethodThis study presents a narrative review of qualitative studies, analyzing a total of 23 articles. The results were extracted and organized into subcategories. After revision by the research team, main categories were identified. These categories encompass both positive and negative outcomes of caregiving.ResultsThe findings of this review demonstrate that caring for a family member with cancer has significant implications for caregivers. These implications include: (A) Positive outcomes of caregiving (such as achieving self-management and balance, promoting kinship intimacy, finding meaning and purpose, and experiencing spiritual growth) and (B) Negative outcomes of caregiving (including care-related physical exhaustion, disruption of personal life plans, psycho-emotional consequences, and socio-economic burden).ConclusionThe results of this study highlight the challenges faced by family caregivers and emphasize the importance of addressing their needs within the healthcare system. By providing support and attention to their well-being, caregivers can enhance their resilience and adaptability in managing caregiving difficulties

Analyzing the Position of Mid-Sized Cities in Azerbaijan Region in order to Achieve a Balanced Regional Development

Documentos apresentados no âmbito do reconhecimento de graus e diplomas estrangeirosAccelerated urbanization and concentration of resources and facilities in metropolises and large cities have caused regional imbalances. This has led to creation of a phenomenon which has result in a form of spatial imbalance and presence of severe differences in labor systems and other activities in Azerbaijan region. Other outcomes of this phenomenon includes the transformation of Tabriz into a primate city and the other two cities of the region, namely Ardabil and Urmia becoming prominent cities at the regional level. The urbanization rate in the Western part of the region is about 75 percent as compared to 25 percent in the eastern half. Therefore, in order to achieve spatial justice, a balanced regional development, strengthening the role of the mid-sized cities was taken into consideration. This would result in a regional balance as has been proposed by such theories of development as Hilhorst’s and kunzmann’s. The research method of this study is based on the descriptive-analysis approach. In order to analyze and identify the trends, three categories of indexes, including the primacy index, urban concentration index and indices of balanced distribution are used. In order to describe and analyze the economic situation, shift-share analysis and location coefficient is used. The results obtained show that with the growth of mid-sized cities, primacy rate and urban concentration would be reduced and the urban system would move towards a balanced condition. Economic indexes show that with the strengthening of the role of the mid-sized cities, the process of the economic situation in Azerbaijan region would improve. Finally, in order to create a more balanced regional development in Azerbaijan region, the mid sized cities in the region’s borders, cities with relief roles, cities with development role, and cities with production functions were identified and located

Investigating phase behaviour and nano-domain characteristics of sphingomyelin/cholesterol membrane using 2H NMR

Sphingomyelin (SM) and cholesterol are major components of the mammalian cell plasma membrane. It is suggested that assemblies of sphingolipids and cholesterol lead to the formation of domains known as “rafts”. In the SM/Cholesterol binary system cholesterol induces formation of a “liquid-ordered” (lo) phase that can coexist with either the “liquid-disordered” (ld) phase or the “solid-ordered” (so) phase. Similar lo-phase domain formation is observed in DPPC/Cholesterol and DPPC/ergosterol systems. Furthermore, cholesterol interacts more strongly with sphingomyelin than DPPC. Deuterium nuclear magnetic resonance spectroscopy (NMR) is used to study the dependence of the phase and nanodomain structure of sphingomyelin/cholesterol membranes on sterol content and temperature. NMR spectra of N-palmitoyl (D31)-D-erythro-sphingosylphosphorylcholine (PSM) were taken for temperatures from 25 to 70oC and cholesterol concentrations 0 - 40%. Analogous experiments were done using 1-palmitoyl,2-palmitoyl(D31)-sn-glycero-3-phosphocholine (DPPC)/cholesterol membranes in order to carefully compare the data obtained using palmitoyl chains which have similar “kinked” conformations. The constructed phase diagrams exhibit both so + lo and ld + lo phase coexistence regions, however macroscopic (micron-sized) coexistence of ld + lo does not occur. Instead, we observed line-broadening in the ld + lo region which was characterized by examining the cholesterol dependence of the quadrupolar splittings and linewidths of the peaks in the depaked spectra, at a given temperature. These results were analyzed by assuming fast exchange of lipids between ld and lo nanodomains which were found to be generally less than 10 nm across. By analyzing the depaked spectrum, information from all orientations of the lipid long axis relative to the magnetic field is pooled. This may obscure the results used to characterize domain size. Selectively deuterated sphingomyelin, labeled at C9 of the N-linked palmitoyl chain, was used to measure the orientation dependence of T2 relaxation time and to more directly calculate domain size. A phenomenological theory based on the hypothesis that fluctuations in local curvature and bilayer thickness are responsible for the orientation dependence of T2 provides an excellent fit to the data. The ld + lo domain sizes calculated using the C9 data agree well with those calculated from the depaked spectrum of PSM

Extracting Ramachandran torsional angle distributions from 2D NMR data using Tikhonov regularization /

Solid state nuclear magnetic resonance (NMR) spectroscopy is a powerful technique for studying structural and dynamical properties of disordered and partially ordered materials, such as glasses, polymers, liquid crystals, and biological materials. In particular, twodimensional( 2D) NMR methods such as ^^C-^^C correlation spectroscopy under the magicangle- spinning (MAS) conditions have been used to measure structural constraints on the secondary structure of proteins and polypeptides. Amyloid fibrils implicated in a broad class of diseases such as Alzheimer's are known to contain a particular repeating structural motif, called a /5-sheet. However, the details of such structures are poorly understood, primarily because the structural constraints extracted from the 2D NMR data in the form of the so-called Ramachandran (backbone torsion) angle distributions, g{^,'4)), are strongly model-dependent. Inverse theory methods are used to extract Ramachandran angle distributions from a set of 2D MAS and constant-time double-quantum-filtered dipolar recoupling (CTDQFD) data. This is a vastly underdetermined problem, and the stability of the inverse mapping is problematic. Tikhonov regularization is a well-known method of improving the stability of the inverse; in this work it is extended to use a new regularization functional based on the Laplacian rather than on the norm of the function itself. In this way, one makes use of the inherently two-dimensional nature of the underlying Ramachandran maps. In addition, a modification of the existing numerical procedure is performed, as appropriate for an underdetermined inverse problem. Stability of the algorithm with respect to the signal-to-noise (S/N) ratio is examined using a simulated data set. The results show excellent convergence to the true angle distribution function g{(j),ii) for the S/N ratio above 100