Search

In recent decades, researchers have begun to investigate innovative sustainable construction materials for the development of greener and more environmentally friendly infrastructures. The main purpose of this article is to investigate the possibility of employing date palm tree waste as a natural fiber alternative for conventional steel and polypropylene fibers (PPFs) in concrete. Date palm fibers are a common agricultural waste in Middle Eastern nations, particularly Saudi Arabia. As a result, this research examined the engineering properties of high-strength concrete using date palm fibers, as well as the performance of traditional steel and PPF concrete. The concrete samples were made using 0.0%, 0.20%, 0.60%, and 1.0% by volume of date palm, steel, and polypropylene fibers. Ten concrete mixtures were made in total. Compressive strength, flexural strength, splitting tensile strength, density, ultrasonic pulse velocity (UPV), water absorption capability, and water permeability tests were performed on the fibrous-reinforced high-strength concrete. With a 1% proportion of date palm, steel, and polypropylene fibers, the splitting tensile strength improved by 17%, 43%, and 16%, respectively. By adding 1% fiber, flexural strength was increased by 60% to 85%, 67% to 165%, and 61% to 79%. In addition, date palm fibers outperformed steel and PPFs in terms of density, UPV, and water permeability. As a result, date palm fibers might potentially be employed in the present construction sector to improve the serviceability of structural elements.

Background: The prognostic significance of preoperative neutrophil to lymphocyte ratio (NLR), lymphocyte to monocyte ratio (LMR), and platelet to lymphocyte ratio (PLR) have been demonstrated in various tumors. This study aimed to evaluate the prognostic role of these ratios in pediatric medulloblastoma. Materials and Methods: Forty-three pediatric patients with medulloblastoma were evaluated, retrospectively. Clinical, radiological, and laboratory data were extracted from the electronic medical records of the patients. Univariate and multivariate Cox proportional hazard models were used to evaluate the impact of suggested variables, including NLR, LMR, and PLR on progression-free survival (PFS) and overall survival (OS). Kaplan-Meier curves were plotted for the assessment of PFS and OS. The Log-rank test was used to assess differences between the PFS and OS in the related categories.  Results: There were 27 males (62.8%) and 16 females (37.2%) with a mean age of 7.4 ±3.3 years. The median OS and PFS were 62.8 ±17.2 and 43.3 ±15.6 months, respectively. The multivariate Cox model showed the clinical risk group, NLR, and LMR as independent predictors of the PFS and the OS (p<0.05). The Log-rank test revealed that OS and PFS were higher in patients with NLR <4 and those with LMR ≥ 3.48 (p <0.05). There were no differences between patients with PLR>200 and PLR< 200 based on OS and PFS. Conclusion: Our results suggest an elevated preoperative NLR and a lowered preoperative LMR as simple predictors of survival in pediatric medulloblastoma. These cost-effective and easily available ratios, along with previously established variables, could be valuable to predict survival in pediatrics with medulloblastoma., (Copyright © 2022 Tehran University of Medical Sciences.)

In this paper, we report the simple preparation and investigation of electrical transport properties of nanoform MoS 2 thin film transistor (TFT) devices. MoS 2 nanoparticles were synthesized by using the hydrothermal method. The physiochemical characterizations such as UV-vis, Fourier transform infrared, X-ray diffraction, and Raman spectroscopy studies were performed. Spin-coating was used to make the thin film on which silver electrodes were made. We observed nonlinear current-voltage (I-V) characteristics; however, the symmetricity was found in the I-V curve which confirms the no formation of the Schottky barrier between thin film and electrodes. Transistor transfer characteristics reveal that the TFT device is n-doped as more drain current modulation is observed when the positive gate voltage is applied. The relationship between gate-current and gate voltage studies concludes that there is no leakage gate current in the TFT device which further confirms the good reliability of transfer characteristics of a device. The device mobility was calculated as ~10.2 cm 2 /Vs, and the same was explained with plausible reason supported with Raman spectra analysis., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2022 Rajasekaran Saminathan et al.)

Human aquaporin-2 (AQP2) is the principal water channel in the human kidney. Any alteration of its physiological functioning may lead to the water imbalance and consequently diseases in humans, especially nephrogenic diabetes insipidus (NDI). Although many of the mutations associated with NDI are experimentally discovered and examined, a molecular level characterization of the structure and transport mechanism is still missing. In this paper, the gating effects of selectivity filter (SF) as wide/narrow states on the mechanism and dynamics of water permeation within the wild-type AQP2 and two NDI causing mutants as AQP2-V168M and AQP2-G64R are studied for the first time. The analysis of the 200 ns trajectory shows that the SF region in AQP2 is not only a selectivity filter, as previously reported but also it performs as a gating site depending on the side-chain conformation of His172. The assignment of the wide/narrow states of SF is supported by computing the free energy and permeability through the AQP2. Moreover, by exploring the effects of V168M and G64R mutants on the AQP2 structure during 200 ns trajectories, remarkable increases of energy barriers are observed in the middle and cytoplasmic side of the pore, respectively. Interestingly, it is found that due to the variable conformations of the SF region as wide/narrow, the effect of the NDI causing mutants on the average water permeability can be revealed with notably better accuracy by finding the wide states in the wild-type and mutated types of AQP2 and comparing the osmotic permeabilities for this state.Communicated by Ramaswamy H. Sarma.

In this paper, non-equilibrium MD simulations (NEMD) of human aquaporin-2 (AQP2) in the presence of an external static electric field have been performed along + z and - z directions of the pore axis. The impacts of the electric field direction on the gating mechanism corresponding to the selectivity filter (SF) region of AQP2 have been studied. Besides, the effects of applied external electric field on the PMF profile of water molecules translocation, water permeability, and molecules dipole orientation are investigated. Our results showed that when the external electric field is implemented along the + z direction of the channels, the selectivity filter region is kept in the wide conformation for the majority of the time. Therefore, a remarkable increase in the overall water permeability can be seen compared to the case without any external electric field. This is in contrast to the effects of - z-directed electric field on the conformations of the selectivity filter, which induces mostly narrow conformations in this constriction region. A substantial higher energy barrier emerged in the middle of the AQP2's pores under the effect of -z-directed electric field in comparison with the zero and + z-directed electric field strengths, which is mainly ascribed to the deviation from bipolar dipole orientation within the AQP2's pores.Communicated by Ramaswamy H. Sarma.

It is widely known that any disruption to the water regulation in aquaporins (AQPs) leads to numerous important diseases. However, studies of dynamics and energetics of disease-causing mutations in the aquaporins on the molecular level are still limited. In the present work, the effects of a skin disease-causing mutant, R188C, on the structure of AQP5 and water transport mechanism within this mutated aquaporin are investigated using the concept of gating mechanism. Our results have revealed that the R188C mutation causes a remarkable increase in the pore radius inside the selectivity filter (SF) region facilitating the passage of water molecules. This observation is supported by plotting the free energy profiles of water molecules transport and calculating permeability values through AQP5-R188C, such that the energy barrier in the SF region of the pores was substantially reduced by this mutation, and therefore, the translocation of water molecules was improved. The total averaged osmotic permeability for R188C has been computed as about 11-fold of the wild-type permeability. However, a comparison between the osmotic permeability values related to the open conformation of CE revealed that this coefficient for AQP5-R188C is about 6.5 times larger than that of wt-AQP5, which can be a more accurate value according to the gating mechanism associated with the constriction region of the aquaporin., (Copyright © 2021. Published by Elsevier B.V.)

Aquaporin-2 plays a vital role in the human kidney as a water passage channel. Any disorder with its function can cause water imbalance and consequently disease in humans, especially nephrogenic diabetes insipidus (NDI). For this reason, an accurate understanding of its performance can be useful for therapeutic purposes. In this article, we investigate the gating mechanism induced by spontaneous fluctuations in aquaporin-2's (AQP2) channels in the palmitoyl-oleoyl-phosphatidyl-ethanolamine lipid bilayer by molecular dynamics. Our results show that the selectivity filter (SF) in AQP2 is also a gating site depending on the side-chain conformation of His172. The important role of His172 in modulating the wide and narrow conformations has been further investigated by the simulation of the H172G mutant. The osmotic permeability values of all four monomers are in the range of wide state and the average is very close to that of the wide channel formed by wild-type AQP2. Moreover, by calculating the osmotic permeability and the potential of mean force of each of the AQP2 monomers for wide/narrow states of the SF, it is seen that the SF at its narrow conformation can induce a much larger energy barrier for water molecules permeation, hindering the transport of water molecules remarkably. The reason for the discrepancy among osmotic permeabilities of different monomers of aquaporins is revealed by investigating the osmotic permeability of each monomer through the wide/narrow states of their SF., (© 2021 Wiley Periodicals LLC.)

Melasma is a common acquired disorder of pigmentation, remains challenging despite numerous treatment modalities. Tranexamic acid (TXA) has emerged as a potential treatment for melasma. Different forms of TXA (oral, topical, and intradermal microinjections) have shown promising results. To evaluate and compare the efficacy of oral vs different dilutions of intradermal TXA in melasma. A total of 45 female patients with melasma were randomly and equally assigned to three treatment groups. Group A (oral TXA 250 mg bid), Group B (100 mg/mL intradermal TXA) & Group C (4 mg/mL intradermal TXA) every 2 weeks, treatment period was 8 weeks. At 8 weeks, a significant reduction in the mMASIwas noted in groups A, B, and C (P value .002, .003, and .005). Melanin index (MI) was significantly reduced in groups A, B, and C (P value .016, .005, and .003). Erythema index (EI) showed significant improvement in group A (P value .028), however was statistically insignificant for groups B and C. No statistically significant difference was found between the three groups as regards changes in mMASI, MI, and EI at 8 weeks. Both oral and intradermal microinjections of TXA regardless dilution appear to be effective and safe in treatment of melasma with comparable results., (© 2021 Wiley Periodicals LLC.)

Metal hybrid additive manufacturing (AM) processes are suitable to create complex structures that advance engineering performance. Hybrid AM can be used to create functionally graded materials for which the variation in microstructure and material properties across the domain is created through a synergized combination of fully-coupled manufacturing processes and/or energy sources. This expansion in the engineering design and manufacturing spaces presents challenges for nondestructive evaluation, including the assessment of the sensitivity of nondestructive measurements to functional gradients. To address this problem, linear ultrasound measurements are used to interrogate 420 stainless steel coupons from three manufacturing methods: wrought, AM, and hybrid AM (directed energy deposition + laser peening). Wave speed, attenuation, and diffuse backscatter results are compared with microhardness measurements along the build/axial direction of the coupons, while microstructure images are used for qualitative verification. The ultrasound measurements compare well with the destructive measurements without any substantial loss in resolution. Furthermore, ultrasonic methods are shown to be effective for identification of the gradient and cyclic nature of the elastic properties and microstructure on the hybrid AM coupon. These results highlight the potential of ultrasound as an efficient and accessible nondestructive characterization method for hybrid AM samples and inform further nondestructive evaluation decisions in AM., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Background: There is a controversy about the management of patients with a thoracolumbar burst fracture. Despite the success of the conservative treatment in most of the cases, some patients failed the conservative treatment. The present study aimed to evaluate risk factors for the need for surgery during the follow-up period in these patients., Methods: We retrospectively evaluated 67 patients with a traumatic thoracolumbar burst fracture who managed conservatively at our center between May 2014 and May 2019. Suggested variables as potential risk factors for the failure of conservative treatment including age, gender, body mass index (BMI), smoking, diabetes, vertebral body compression rate (VBCR), percentage of anterior height compression (PAHC), Cobb angle, interpedicular distance (IPD), canal compromise, and pain intensity as visual analog scale (VAS) were compared between patients with successful conservative treatment and those with failure of non-operative management., Results: There were 41 males (61.2%) and 26 females (38.8%) with the mean follow-up time of 15.52 ± 5.30 months. Overall, 51 patients (76.1%) successfully completed conservative treatment. However, 16 cases (23.9%) failed the non-operative management. According to the binary logistic regression analysis, only age (risk ratio [RR], 2.21; 95% confidence interval [95%], 1.78-2.64; P = 0.019) and IPD (RR 1.97; 95% CI 1.61-2.33; P = 0.005) were the independent risk factors for the failure of the non-operative management., Conclusions: Our results showed that older patients and those with greater interpedicular distance are at a higher risk for failure of the conservative treatment. As a result, a closer follow-up should be considered for them.

Background: Carpal tunnel syndrome (CTS) is the most common peripheral neuropathy. Moreover, carpal tunnel release (CTR) surgery generally has excellent results. The present study aimed to investigate the predictors of clinical outcomes and satisfaction in patients with CTR., Methods: In this observational prospective cohort study, 152 patients with open carpal tunnel release surgery were investigated. Complete clinical examinations were performed and recorded before the surgery, two weeks after the surgery and 6 months after the surgery. The Boston Carpal Tunnel Questionnaire (BCTQ) were assessed on admission and at last follow-up visits to evaluate clinical outcomes. Patients' satisfaction was determined by a 10-point verbal descriptor nominal scale (1 = very poor, 5 = fair and 10 = excellent) and recorded during the last follow -up visits., Results: Among 152 patients who were investigated, there were 118 (77.6%) females and 34 (22.36%) males. Overall, surgery improved the outcomes based on Symptom Severity Scale (SSS) and Functional Status Scale (FSS) (P < 0.05). Most of the considered variables did not show significant effects on clinical outcomes and patients' satisfaction. However, duration of symptoms and electrophysiological severity were the predictors of the change score in SSS(P < 0.05). As well as, age was the only predictor of the change score in FSS (P < 0.05). Finally, according to the linear regression model, the pre-operative grip strength and age were the independent predictors of post-operative satisfaction (P < 0.05)., Conclusions: Results of the present study revealed that there was a significant improvement in clinical outcomes after CTS surgery. Stronger pre-operative grip strength and younger age were independent predictors of higher post-operative satisfaction. These results can be used in pre-operative counseling and management of post-operative expectations.

Background: Vitiligo is an acquired, multifactorial disorder of the skin and mucous membranes. An elevated homocysteine level has been described in vitiligo. Methylenetetrahydrofolate reductase (MTHFR) and cystathionine B synthase (CBS) are major determinants of the homocysteine metabolism., Objectives: Determine serum homocysteine levels in vitiligo patients as well as the association between MTHFR (C677T, A1298C) and CBSgene polymorphisms and susceptibility to vitiligo in a sample of those populations., Methods: Homocysteine levels were estimated by radioimmunoassay while MTHFR (C677T, A1298C) and CBSgene polymorphisms were detected by the polymerase chain reaction-restriction fragment length polymorphism technique in 100 vitiligo patients and 80 healthy controls., Results: The homocysteine level was significantly higher in vitiligo patients than controls (p = 0.000). Significant differences in the genotype and allele distributions of single nucleotide polymorphisms of the MTHFR (C677T, A1298C) with the mutant genotypes are more common in the controls than patients (p = 0.001, 0.029, respectively). CBS gene mutant genotypes and alleles are more common in vitiligo patients than controls (p = 0.002)., Conclusion: CBSand MTHFRgene polymorphisms may play a major role in the genetic susceptibility to vitiligo., (© 2019 S. Karger AG, Basel.)

The objective of this study is to characterize the micromechanical properties of poly-l-lactic acid (PLLA) composites reinforced by grade 420 stainless steel (SS) particles with a specific focus on the interphase properties. The specimens were manufactured using 3D printing techniques due to its many benefits, including high accuracy, cost effectiveness and customized geometry. The adopted fused filament fabrication resulted in a thin interphase layer with an average thickness of 3 µm. The mechanical properties of each phase, as well as the interphase, were characterized by nanoindentation tests. The effect of matrix degradation, i.e., imperfect bonding, on the elastic modulus of the composite was further examined by a representative volume element (RVE) model. The results showed that the interphase layer provided a smooth transition of elastic modulus from steel particles to the polymeric matrix. A 10% volume fraction of steel particles could enhance the elastic modulus of PLLA polymer by 31%. In addition, steel particles took 37% to 59% of the applied load with respect to the particle volume fraction. We found that degradation of the interphase reduced the elastic modulus of the composite by 70% and 7% under tensile and compressive loads, respectively. The shear modulus of the composite with 10% particles decreased by 36%, i.e., lower than pure PLLA, when debonding occurred.

Background and Objective: Clopidogrel is a potent antiplatelet drug that reduces the risk of vascular events in patients with cardiovascular disease. However, several studies have shown that about a quarter of patients showed low or no response to clopidogrel therapy. In this study, factors that contribute to clopidogrel resistance were investigated in 270 cardiovascular disease patients from Jordan., Patients and Methods: Clopidogrel resistance was determined through platelet aggregation analysis using the Multiplate analyzer®. Genetic factors (CYP2C19*2 and PON1 Q192R) were examined using polymerase chain reaction-restriction fragment length polymorphism analysis., Results: The incidence of clopidogrel resistance among Jordanians is about 32%. Significant association between clopidogrel resistance and female gender, concomitant use of calcium channel blockers, and low HDL was found (p < 0.05). In addition, presence of CYP2C19*2 allele is strongly related to clopidogrel resistance (p < 0.001). However, lack of contribution to clipidogrel resistance was found for PON1 Q192R polymorphism, age, diabetes, hypertension, smoking and aspirin use (p > 0.05)., Conclusion: Several factors might contribute to clopidogrel resistance including gender, concomitant use of calcium channel blockers, HDL and CYP2C19*2 polymorphism.

Background: Conventional therapy of extensive psoriasis is effective but has complications. Biologics are safer but expensive., Objective: To assess the efficacy of sulfasalazine and pentoxifylline, which have TNF antagonizing and anti-proliferative action in the treatment of psoriasis., Methods: In this randomized controlled trial, 32 patients with extensive psoriasis were divided into four groups: group A received sulfasalazine; group B received pentoxifylline; group C received both drugs; and group D received methotrexate. The Psoriasis Area and Severity Index (PASI) score was done at weeks 0, 2, 4, 6 and 8., Results: A significant reduction in PASI score occurred in groups C and D (p = 0.043 and 0.018, respectively). A significantly higher percentage of PASI score reduction occurred in group D compared with groups A, B and C (p = 0.006, 0.003 and 0.030, respectively). An excellent response occurred in one patient (14.3%) in group D. A very good response occurred in two patients (22.2%) in group C, and in five patients (71.4%) in group D. A moderate response occurred in three patients (37.5%) in group A, one patient (12.5%) in group B, and one patient (14.3%) in group D., Conclusion: Although incomparable to methotrexate, combined sulfasalazine and pentoxifylline produced a good response in cases of extensive psoriasis. Multicentre studies are needed to validate these results.