34 research outputs found
SOME VECTORS FIELDS ON THE TANGENT BUNDLE WITH A SEMI-SYMMETRIC METRIC CONNECTION
Let is a (pseudo-)Riemannian manifold and be its tangent bundlewith the semi-symmetric metric connection . In thispaper, we examine some special vector fields, such as incompressible vectorfields, harmonic vector fields, concurrent vector fields, conformal vectorfields and projective vector fields on with respect to thesemi-symmetric metric connection and obtain someproperties related to them
Structural Insights into Allosteric Modulation of NMDA Receptors Through the Amino-Terminal Domain
Majority of fast excitatory synaptic transmission in the mammalian brain is mediated by a class of molecules called ionotropic glutamate receptors, which include N-methyl-D-aspartate (NMDA) receptors. NMDA receptors are hetero-tetrameric ion channels that are composed of two NR1 subunits and two NR2 (A-D) subunits or NR3 subunits. NMDA receptors play key roles in numbers of important processes including synaptic plasticity and development in normal state, whereas aberrant activity of NMDA receptors is associated with ischemic brain injury and neurodegenerative diseases including Parkinson's disease and Alzheimer's disease. Activity of NMDA receptor is tightly controlled through multiple pathways. One such mechanism is allosteric modulation through binding of small molecules to the extracellular amino terminal domain (ATD) in a subtype specific manner, i.e. polyamines and protons bind NR1, Zn2+ binds both NR2A and NR2B, and phenylethanolamine compounds bind NR2B. To understand the molecular mechanism of the ATD-dependent allosteric modulation of NMDA receptors, we have solved the structures of NR2B ATD in the zinc-bound and -free forms. The structures reveal an overall clamshell architecture with a unique domain orientation distinct from the non-NMDA receptor ATDs and molecular determinants for the zinc binding site, ion binding sites, and the architecture of the putative phenylethanolamine binding site
Structural Determinants and Mechanism of Action of a GluN2C-selective NMDA Receptor Positive Allosteric Modulator
Care burden and quality of life of home caregivers
This study was conducted to determine the care burden and quality of life of the primary caregivers of home care patients and to investigate the factors that affect them and the relationship between them. The study was designed as a descriptive, cross-sectional, and correlational study. The quality of life of caregivers who expressed that they had financial problems was lower than those who did not have financial problems (p [Med-Science 2020; 9(3.000): 714-20
Evaluation of Pediatric Fingertip Injuries Using Etiology, Demographics and Therapy
WOS:000569696900007PubMed: 33312028Objectives: In this study, 354 pediatric cases were evaluated and treated at the emergency service department due to fingertip injuries in a four years period. The data were studied using etiology, demographics, treatment and complications. This study aims to draw attention to fingertip injuries that are very common in childhood and to help developing preventive strategies. Methods: Of the 354 patients, 191 were boys and 163 were girls. Their ages ranged from six months to 17 years. These patients were studied concerning sex, injured hand and fingers, injury mechanism, injury zone, selected treatment modalities and complications. All interventions were performed under local anesthesia at the emergency service department. Patients were discharged on the same day. Results: In our study group, the male patients (54%) were more affected than the girls (46%). It was observed that the right hand (65.3%) was much more vulnerable to the injury than the left hand (34.7%). It was determined that the most injured fingers were middle fingers in the 136 (38.4%) of the patients, followed by the ring finger (33.9%). Injury was most frequent at five years old patient group. The most frequent type of injury was crush type injuries with a rate of 83.3%, and among crush type injuries, the most common mechanism was trapping of fingers in the doors or windows. While many of these injuries required surgical intervention, appropriate patients were treated with wound care and secondary wound healing. Conclusion: In childhood, hand injuries are quite frequent and fingertip injuries constitute the majority of these entities. These childhood injuries lead to significant functional, aesthetic and psychological sequelae in these patients. The knowledge about the etiology, distribution and mechanisms of these injuries will enable the development of preventive measures in this regard
Emerging structural insights into the function of ionotropic glutamate receptors
Ionotropic glutamate receptors (iGluRs) are ligand-gated ion channels that mediate excitatory neurotransmission crucial for brain development and function, including learning and memory formation. Recently a wealth of structural studies on iGluRs including AMPA receptors (AMPARs), kainate receptors, and NMDA receptors (NMDARs) became available. These studies showed structures of non-NMDARs including AMPAR and kainate receptor in various functional states, thereby providing the first visual sense of how non-NMDAR iGluRs may function in the context of homotetramers. Furthermore, they provided the first view of heterotetrameric NMDAR ion channels, and this illuminated the similarities with and differences from non-NMDARs, thus raising a mechanistic distinction between the two groups of iGluRs. We review mechanistic insights into iGluR functions gained through structural studies of multiple groups
Investigation of sociodemographic and health characteristics of mothers in low birth weight newborns in Malatya city center
The prerequisite for a healthy life is to be born healty. Low birth weight (LBW) is an important risk factor for morbidity and mortality in early or late period of life. So reducing the incidence of low birth weight not only lowers infant mortality rates but also has multiple benefits over the life cycle.The purpose of this study is to find out whether the differences in terms of socio-demographic and health characteristics of newborns mothers with LBW than normal weight ones. This study covers to the mothers who gave birth in obstetrics and gynecology clinics of two hospitals during March and June 2010 in Malatya city center. It is a case-control study according to the time scheduled beeing a cross-sectional. The 45-item questionnaire surveyed to 350 mothers of newbors selected by random procedure was performed by the method of face-to-face interview. 123 newborns under 2500 grams as case group, 227 infants 2500 grams and over were taken as control. For evaluation of the data used by SPSS program, chi-square test for independent samples was performed in analysis. 95% confidence interval, and error level of p = 0.05 was chosen. 58.3% of the mothers\' ages ranged from 20 to 30 in the study included. 28.0% of the mothers\' education level was primary school or less, 28.9% had seen in the higher-level education. 57,4% of mothers were housewives and 26.9% of those had a monthly income 550 $ below. 85.1% of mothers have lived in urban area and 14.9% in the villages. At the end of this study; 5.4 times (95% CI = 2.2 [Med-Science 2013; 2(3.000): 665-78
Molecular Basis for Subtype Specificity and High-Affinity Zinc Inhibition in the GluN1-GluN2A NMDA Receptor Amino-Terminal Domain
Summary Zinc is vastly present in the mammalian brain and controls functions of various cell surface receptors to regulate neurotransmission. A distinctive characteristic of N-methyl-D-aspartate (NMDA) receptors containing a GluN2A subunit is that their ion channel activity is allosterically inhibited by a nano-molar concentration of zinc that binds to an extracellular domain called an amino-terminal domain (ATD). Despite physiological importance, the molecular mechanism underlying the high-affinity zinc inhibition has been incomplete because of the lack of a GluN2A ATD structure. Here we show the first crystal structures of the heterodimeric GluN1-GluN2A ATD, which provide the complete map of the high-affinity zinc-binding site and reveal distinctive features from the ATD of the GluN1-GluN2B subtype. Perturbation of hydrogen bond networks at the hinge of the GluN2A bi-lobe structure affects both zinc inhibition and open probability, supporting the general model in which the bi-lobe motion in ATD regulates the channel activity in NMDA receptors
<i>E</i>-Connections on the <i>ε</i>-Anti-Kähler Manifolds
The paper undertakes certain special forms of the quarter symmetric metric and non-metric connections on an ε-anti-Kähler manifold. Firstly, we deduce the relation between the Riemannian connection and the special forms of the quarter symmetric metric and non-metric connections. Then, we present some results concerning the torsion tensors of these connections. In addition, we find the forms of the curvature tensor, the Ricci curvature tensor and scalar curvature of such connections and we search the conditions for the ε-anti-Kähler manifold to be an Einstein space with respect to these connections. Finally, we study U(Ric)-vector fields with respect to these connections and give some results related to them