State-dependent modulation of cortico-spinal networks

Beta-band rhythm (13-30 Hz) is a dominant oscillatory activity in the sensorimotor system. Numerous studies reported on links between motor performance and the cortical and cortico-spinal beta rhythm. However, these studies report divergent beta-band frequencies and are, additionally, based on differently performed motor-tasks (e.g., motor imagination, muscle contraction, reach, grasp, and attention). This diversity blurs the role of beta in the sensorimotor system. It consequently challenges the development of beta-band activity-dependent stimulation protocols in the sensorimotor system. In this vein, we studied the functional role of beta-band cortico-cortical and cortico-spinal networks during a motor learning task. We studied how the contribution of cortical and spinal beta changes in the course of learning, and how this modulation is affected by afferent feedback to the sensorimotor system. We furthermore researched the relationship to motor performance. Consider that we made our study in the absence of any residual movement to allow our findings to be translated into rehabilitation programs for severely affected stroke patients. This thesis, at first, investigates evoked responses after transcranial magnetic stimulation (TMS). This revealed two different beta-band networks, i.e., in the low and high beta-band reflecting cortical and cortico-spinal activity. We, then, used a broader frequency range in the beta-band to trigger passive opening of the hand (peripheral feedback) or cortical stimulation (cortical feedback). While a unilateral hemispheric increase in cortico-spinal synchronization was observed in the group with peripheral feedback, a bilateral hemispheric increase in cortico-cortical and cortico-spinal synchronization was observed for the group with cortical feedback. An improvement in motor performance was found in the peripheral group only. Additionally, an enhancement in the directed cortico-spinal synchronization from cortex to periphery was observed for the peripheral group. Similar neurophysiological and behavioral changes were observed for stroke patients receiving peripheral feedback. The results 6 suggest two different mechanisms for beta-band activity-dependent protocols depending on the feedback modality. While the peripheral feedback appears to increase the synchronization among neural groups, cortical stimulation appears to recruit dormant neurons and to extend the involved motor network. These findings may provide insights regarding the mechanism behind novel activity-dependent protocols. It also highlights the importance of afferent feedback for motor restoration in beta-band activity-dependent rehabilitation programs

Using biocompatible materials as substrate coating for electric field enhancement in tip-enhanced Raman spectroscopy

In this article, tip-enhanced Raman spectroscopy (TERS) is investigated as a precise method for analysis of biological samples. Using Finite Difference Time Domain (FDTD) simulation, it has been tried to design the required structures for analysis of these samples. At first, by comparing different TERS structures and considering the material, dimensions and other parameters in the simulation, the ideal structure is introduced from a physical point of view and considering the electric field enhancement. In the following, taking into possibility of the effect of environmental and chemical reactions during testing on biological samples, biocompatible materials are used as substrate coating in the simulation, and the effect of using these materials are investigated in comparison with the previous conditions. After performing the simulations, we concluded that Au, Cu and Ag have the highest electric field enhancement, respectively, and the presence of Au next to Cu, also Au and Cu next to Ag, leads to the enhancement of the electric field in them. In the following, we found that the material and thickness of the layer under the coating in the substrate and tip have a great effect on the enhancement. finally, using five biocompatible materials as a coating in the case of using the Au tip and substrate, which creates the most electric field enhancement, we saw that the use of biocompatible materials greatly reduces the enhancement and the use of these five materials does not differ much from each other. Anyway, the use of a 1 nm layer of biocompatible coating creates a much more favorable effect on enhancement than upper thicknesses

Efficient conjugation of anti-HBsAg antibody to modified core-shell magnetic nanoparticles (Fe3O4@SiO2/NH2)

Introduction: Further development of magnetic-based detection techniques could be of significant use in increasing the sensitivity of detection and quantification of hepatitis B virus (HBV) infection. The present work addresses the fabrication and characterization of a new bio-nano composite based on the immobilization of goat anti-HBsAg antibody on modified core-shell magnetic nanoparticles (NPs) by (3-aminopropyl) triethoxysilane (APTES), named Fe3O4@SiO2/NH2, and magnetic NPs modified by chitosan (Fe3O4@CS). Methods: At the first step, Fe3O4 was modified with the silica and APTES (Fe3O4@SiO2/NH2) and chitosan (Fe3O4@CS) separately. The goat anti-HBsAg antibody was activated by two different protocols: Sodium periodate and EDC-NHS. Then the resulted composites were conjugated with activated goat anti-HBsAg IgG. An external magnet collected Bio-super magnetic NPs (BSMNPs) and the remained solution was analyzed by the Bradford method to check the amount of attached antibody to the surface of BSMNPs. Results: The findings indicated that activation of antibodies by sodium periodate method 15-17 µg antibody immobilized on 1 mg of super magnetic nanoparticles (SMNPs). However, in the EDC-NHS method, 8-10 µg of antibody was conjugated with 1 mg of SMNPs. The resulting bio-magnetic NPs were applied for interaction with the HBsAg target using enzyme-linked immunosorbent assay (ELISA). About 1 µg antigen attached to 1 mg SMNPs, which demonstrated that the fabricated materials are applicable in the detection scope of HBsAg. Conclusion: In the present study, we developed new antibody-conjugated magnetic NPs for the detection of HBsAg using an efficient conjugation strategy. The results demonstrated that the binding capacity of Fe3O4@SiO2/NH2 was comparable with commercially available products. Our designed method for conjugating anti-HBsAg antibody to a magnetic nanoparticle opens the way to produce a high capacity of magnetic NPs

Glutathione-dependent enzymes in the follicular fluid of the first-retrieved oocyte and their impact on oocyte and embryos in polycystic ovary syndrome: A cross-sectional study

Background: Oxidative stress and GSH-dependent antioxidant system plays a key role in the pathogenesis of polycystic ovary syndrome (PCOS). Objective: We compared glutathione peroxidase (GPx) and glutathione reductase activities and reduced glutathione (GSH) levels in serum and follicular fluid (FF) of the first-retrieved follicle and their impact on quality of oocyte and embryo in PCOS women undergoing IVF. Materials and Methods: This cross-sectional study was conducted on 80 pairs of blood samples and FF of the first-retrieved follicle from PCOS women, at the Infertility center of Ghadir Mother and Child Hospital. The mean activity of GPx and GR, also GSH levels in the serum and FF were compared to the quality of the first follicle and resultant embryo. Results: Retrieved oocytes included 53 (66.25%) MII, 17 (21.25%) MI, and 10 (12.5%) germinal vesicles; after IVF 42 (52.50%) embryos with grade I and 11 (13.75%) with grade II were produced. The mean values for all three antioxidants were higher in the FF compared to serum (p < 0.001). Also all of the mean measured levels were significantly higher in the FF of the MII oocytes compared to that of oocytes with lower grades (p = 0.012, 0.006 and 0.012, respectively). The mean GPX activity and GSH levels were significantly higher in the serum (p = 0.016 and 0.012, respectively) and FF (p = 0.001 for both) of the high-quality grade I embryos. Conclusion: GSH-dependent antioxidant system functions more efficiently in the FF of oocytes and embryos with higher quality. Key words: In vitro fertilization, Glutathione, Antioxidant, Oocyte, Embryo.&nbsp

Detection and estimation of Platelet- derived MicroParticles Quantity during Storage Time

Background: Platelet MPs are produced automatically during platelet storage. Their size is about 0.1 – 1 µm and have ability for sub- endothelium adhering, strengthen of platelet aggregation and also platelet pre- coagulation. In fact, the release of membrane particles helps to signal to the neighbor cells or to seclude target cells from apoptosis. The purpose of this study is to determine the effect of time passing on platelet MPs production.Methods: In this experimental study, 12 units of PC from healthy donors were obtained. Sampling was done at 2, 3, 5 and 7 days after storage. After separating of MPs, they were prepared for flow cytometery analyses by anti- CD41a FITC and assessed their concentration through Bradford methods. Paired sample T-test and ANOVA were used to compare the results and investigate the probable significant differences of this experiment.Results: There was no significant difference in platelet MPs concentration between PC stored in day 2 and 3. (P> 0.05) On the other hand, we could claim significant differences in platelet MPs concentration between PC stored in day 3 and day 5 and also between day 5 and day 7. (P< 0.05)Conclusions: We showed that the production or releasing of platelet MPs were considerable by passing time. Also by increasing of  storage time, platelet component included more MPs which were able to signal and produce interaction with other cells in patient receiving bodies. As a result, it was possible to interfere in their immune responses, inflammatory or coagulation processes after transfusio

Detection and estimation of Platelet- derived MicroParticles Quantity during Storage Time

Background: Platelet MPs are produced automatically during platelet storage. Their size is about 0.1 – 1 µm and have ability for sub- endothelium adhering, strengthen of platelet aggregation and also platelet pre- coagulation. In fact, the release of membrane particles helps to signal to the neighbor cells or to seclude target cells from apoptosis. The purpose of this study is to determine the effect of time passing on platelet MPs production.Methods: In this experimental study, 12 units of PC from healthy donors were obtained. Sampling was done at 2, 3, 5 and 7 days after storage. After separating of MPs, they were prepared for flow cytometery analyses by anti- CD41a FITC and assessed their concentration through Bradford methods. Paired sample T-test and ANOVA were used to compare the results and investigate the probable significant differences of this experiment.Results: There was no significant difference in platelet MPs concentration between PC stored in day 2 and 3. (P> 0.05) On the other hand, we could claim significant differences in platelet MPs concentration between PC stored in day 3 and day 5 and also between day 5 and day 7. (P< 0.05)Conclusions: We showed that the production or releasing of platelet MPs were considerable by passing time. Also by increasing of  storage time, platelet component included more MPs which were able to signal and produce interaction with other cells in patient receiving bodies. As a result, it was possible to interfere in their immune responses, inflammatory or coagulation processes after transfusio

Using visible and near infrared spectroscopy to estimate carbonates and gypsum in soils in arid and subhumid regions of Isfahan, Iran

Soils in arid and semi-arid regions are strongly affected by the accumulation of carbonates, gypsum and other, more soluble, salts. Carbonates and gypsum both have a considerable influence on soil properties, especially the chemical properties of the soil solution. The development of reliable, fast and inexpensive methods to quantify the amounts of carbonates and gypsum in soil is therefore important. Visible and near infrared (vis-NIR) spectroscopy is a non-destructive, rapid and cheap method for measuring several soil properties simultaneously. However, research on vis-NIR spectroscopy in quantifying carbonates and gypsum is limited. Therefore, this study evaluated the efficiency of vis-NIR spectroscopy in quantifying carbonates and gypsum in surface soils using partial least-squares regression (PLSR) compared with standard laboratory methods and compared PLSR with a feature-specific method using continuum removal (CR). Carbonates and gypsum in a total of 251 sieved and air-dried topsoil samples from Isfahan Province in central Iran were measured by standard laboratory methods and vis-NIR spectroscopy (350–2500 nm wavelength range). In parallel, PLSR and the feature-specific method based on CR spectra were used to predict carbonates and gypsum. The PLSR model efficiency (E) for carbonates and gypsum in the validation set was 0.52 and 0.80, respectively. The PLSR model resulted in better predictions than the feature-specific method for both soil properties. Because of the unique absorption features of gypsum, which did not overlap with other soil properties, predictions of gypsum resulted in higher E values and lower errors than predictions of carbonates

Prevalence and Risk Factors of Toxoplasma gondii Infection among Pregnant Women in Hormozgan Province, South of Iran

Background: Toxoplasmosis can cause miscarriage or complications in the fetus. Diagnosis and treatment of this disease by anti-parasitic drugs especially in early pregnancy can help to prevent fetal infection and its complications. This study aimed to determine T. gondii infection in pregnant women, evaluate risk factors in the transmission of the disease and congenital toxoplasmosis. Methods: Overall, 360 sera of pregnant women from 5 cities in the Hormozgan Province in southern Iran with different climate were evaluated from 2015-2016 for T. gondii infection by using ELISA method and positive cases of IgM and IgG were tested again using Avidity IgG ELISA. All cases were evaluated according to climate, acute and chronic of toxoplasmosis, number of pregnancy and abortion, epidemiological factors and food habits. Results: Among 360 specimens T. gondii IgG + IgM antibodies were found positive in 0. 8% subjects and also 27% of samples had IgG seropositivity. A significant relationship was observed between age, sampling place, consumption of raw and half cooked meat, history of contact with cats, abortion history, number of children, and parity with IgG positive. In Avidity IgG ELISA test, 13 people with low avidity, 3 people with borderline avidity were reported. Conclusion: 72. 2% of the population had no antibody against the disease that this could be a warning to the people and requires education of preventive and prenatal care and routine screening of women at childbearing age

Translation and validation of Neonatal Feeding Assessment Scale (NFAS) in Persian

Background: Feeding difficulties and dysphagia can lead to malnutrition, dehydration, pneumonia, prolonged hospitalization, and even death in neonates. Accordingly, it should be recognized as soon as possible to provide necessary medical care, nursing, and rehabilitation. This study aimed to translate the Neonatal Feeding Assessment Scale (NFAS) into Persian and determine its psychometric properties in Iranian neonates.Methods: After receiving permission from developers, the main version of NFAS was translated into Persian. Face validity of NFAS was assessed by 10 qualified speech and language pathologists in the field of pediatric swallowing. In order to define the internal consistency of the items, 52 infants were evaluated using the Persian version of NFAS, and the correlation between the items was determined using Kuder-Richardson 20. The test-retest and inter-rater reliabilities were also calculated by Cohen's Kappa coefficient in 30 and 40 infants, respectively. The convergent reliability between NFAS and Early Feeding Skills (EFS) was calculated by point-biserial correlation in 30 infants.Results: According to experts, all translated items were transparent and understandable. The internal consistency score was obtained at 0.76. Moreover, Cohen's Kappa coefficients were calculated at 0.96 and 0.87 for test-retest and inter-rated reliabilities, respectively. Point biserial correlation between Persian NFAS and EFS was estimated at 0.63.Conclusion: Persian version of NFAS is a valid and reliable tool to assess feeding problems and oro-pharyngeal dysphagia in infants and make clinical decisions