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The novelty of this work is to fabricate the double-walled (DW) TiO2 nanotube arrays (TNAs) by an anode oxidation method with NH4F-based electrolyte and Zinc counter electrode (CE, c-Zn) and to investigate the photodegradation performance of these TNAs. The structural, optical, and photodegradation performance of TNAs with c-Zn material have been compared to the properties of TNAs with the other two CEs like c-Pt (Platinum) and c-Ti (Titanium). The counter electrode has a tremendous influence on the structural properties and geometrical features of TNAs. The TNAs fabricated with c-Zn have the red-shifted absorption edge with two bandgaps such as 3.15 and 1.78 eV. Interestingly, the TNAs with c-Zn are found as the DW TNAs with outer diameter of 130 ± 3 nm, thinner outer wall thickness of 12 ± 2 nm, and thicker inner wall thickness of 30 ± 2 nm. The photodegradation performance varies with different counter electrodes during the deposition of TNAs by the anode oxidation method. The TNAs sample prepared with c-Zn has shown the highest roughness value of 305.0 nm, photodegradation efficiency of 97.0%, and the rate constant value of 0.00985 min−1 than the other TNAs with c-Pt, c-Ti, and other researcher's data. Moreover, the optical, structural, and surface morphological properties of TNAs have correlated with the photodegradation performance of TNAs prepared with various counter electrodes during deposition.

In this paper, the performance of GaAs and GaSb based sub-10 nm double-gate junctionless metal-oxide-semiconductor field-effect transistors (DG-JLMOSFETs) have been studied for high-performance switching applications. The quantum transmitting boundary method (QTBM) has been considered for electron transport, and the band structures are accounted for sp3d5s* tight-binding modeling. The channel thickness, tch is varied from 1.7 to 4.7 nm to evaluate the device figure of merits (FOMs). The thinner channel’s device shows a lower OFF-state current, while the ticker channel device allows a higher ON-state current. The threshold voltage is approximately 0.4 V for GaAs DG-JLMOSFETs with tch = 1.7 nm, whereas it reduces to ~0.05 V for that of tch = 4.7 nm. Similar characteristics have been shown in GaSb devices. Besides, a significant impact of tch on the subthreshold swing (SS) and drain-induced barrier lowering (DIBL) is found in GaSb DG-JLMOSFETs compared with those of GaAs devices. The devices show a higher leakage-power dissipation in both channel materials and low-intrinsic delay for thicker tch due to a substantial amount of energy drop. The above results indicate that III-V-based DG-JLMOSFETs are very promising for next-generation high-performance switching technology.

Hypertrophic scars and keloids are forms of abnormal wound healing. Both entities are the result of exuberant fibroblast response in the dermis. Nevertheless, their clinical and histopathological characteristics, as well as their pathogenesis, are differentThe aim of this study was to study the role of neuregulin- 1 in the pathogenesis of hypertrophic scars and keloids and studying the change in tissue expression after intralesional bleomycin injection. This prospective case - control study was carried on20patients who were suffering from keloids or hypertrophic scarsand were treated by intra lesional bleomycin injection, in addition to 20 apparently healthy individuals as a control group. Assement of hypertrophic scars and keloids before and after treatment byVancouver scar scale laboratory investigations including punch biopsies from hypertrophic scars, keloids and normal tissues, qRT-PCRfor gene expression of Neuregulin1 RNA was done. HTS group before treatment showed significantly higher level of neuregulin 1 but significantly lower after treatment and neuregulin 1 sensitivity was 80%, specificity was 100%,and accuracy was 90%.Neuregulin 1 before treatment showed significant positive correlation with Neuregulin 1after treatment.Better response was significantly associated with Lower baseline neuregulin 1.Higher neuregulin 1 was considered as risk predictor of HTS or keloid susceptibility and severity. Bleomycin usage has a better result and minimal complications and less recurrence rate, which shows its usefulness as the first-line treatment modality for management of keloids and hypertrophic scars.

BACKGROUND Although the etiopathogenesis of alopecia areata (AA) is still unclear, inflammation, oxidative stress, and subsequent DNA damage might be considered role players in disease development. AIM We aimed at exploring the potential link between oxidative DNA damage and inflammation in AA patients through measuring 8-hydroxy deoxyguanosine (8-OHdG), high mobility group box 1 protein (HMGB1), and one of the inflammatory mediators, C-reactive protein (CRP). METHODS A total of 79 subjects (49 AA patients in addition to 30 apparently healthy control subjects) were tested for serum levels of 8-OHdG, HMBG1, and CRP. RESULTS Compared with the control group, serum 8-OHdG, HMBG1, and CRP levels were significantly elevated in the studied patients group (0.031

Novel GaN-based van der Walls (vdW) hetero-bilayer (HBL) is systemically studied through the first-principles density functional theory (DFT) framework to explore its optoelectronic property facilitated photocatalytic activity for hydrogen (H2) fuel production. The vdW concept of planar GaN with GeC monolayer, together making stacked hetero-bilayer, shows unique and tunable optoelectronic properties that fulfill all the photocatalysis attributes. The confirmation of chemical and dynamical stabilities is made with negative interlayer binding energy and non-negative frequency in phonon spectra, respectively. Among the dynamically stable hetero-bilayers, binding energy in HBL 2 (AB1) is the lowest and interlayer distance ~2.954A is the smallest. The HBLs are sensitive to the stacking arrangements, where HBL 2 demonstrates type-I direct bandgap and HBL 6 (AB6) is Type-II direct bandgap. The intrinsic HBLs show superior carrier mobility as their effective masses are lower from their constituent monolayers. Also, the intrinsic absorption coefficient of the HBLs increase as high as ~106 cm−1, 10 times greater than conventional perovskite materials, which show outperforming optoelectronic conversion efficiency. Additionally, the HBLs are highly tunable in both bandgap and type due to biaxial strains and cross-plane electric fields. With biaxial strains, from compressive to tensile, both HBLs show monotonous bandgap lowering with a dominant direct-indirect bandgap splitting in HBL 2. Interestingly, for all the biaxial strains within the −6% to +6% range, both HBLs have sufficient kinetic overpotential for photocatalytic water splitting and an increase in visible peak by 3.5 (2) times in the HBL 6 (HBL 2). Electric fields also increase the photocatalytic water splitting performance with a net bandgap lowering and increasing the visible absorption peak by ~1.5 times compared with intrinsic HBLs. These promising properties that we have found in the planar GaN/GeC vdW hetero-bilayer are highly suggestive for the impending use of this material in photocatalytic water splitting technology to produce H2 fuel.

The objective of this study was to evaluate the nutritional, non-nutritional as well as physico-chemical characteristics of biscuits developed from the supplementation of wheat flour with different levels of whey protein concentrate (WPC). The biscuits were prepared by using composite blends of wheat flour (WF) and WPC in different combination such as 100:0 (WF), 95:5 (WWP 5%), 90:10 (WWP 10%) and 85:15 (WWP 15). Proximate analysis of control as well as treated sample showed significant rise in crude protein content, with increase in WPC supplementation. Moreover, Non-nutritional factor such as tannin content and polyphenols was found to be highest in WF sample followed by WWP (5%), WWP (10%) and WWP (15%). In addition to that, in-vitro protein digestibility (IVPD) was found to be highest in WPC and when IVPD was compared with the crude protein, a significant difference was observed. Additionally, with the increase in WPC ratio the concentration of lysine, aspartic acid and glutamic acid was improved. Moreover mineral analysis revealed that, WF had highest amount of iron 0.66 mg/100g followed by WWP (5%), WWP (10%), WWP (15%) and WPC. Moreover, spread ratio of cookies found to be significant with the increase in the levels of WPC. Sensory evaluation of the samples revealed that, WWP (15%) had highest acceptance rating followed by WWP (10%). Based upon our investigation, we found that WPC could be a good source of supplementation for the development of protein enriched biscuits to combat the problem of malnutrition.

Dioctyl phthalate (DOP) is industrially commonly used as a polyvinyl chloride (PVC) plasticiser. As DOP does not form a chemical link with PVC, it migrates from flexible PVC segments into the media in contact, a matter that arose concerns due to its noxious effect. Despite the introduction of several non-DOP-based plasticisers recently, most of these new plasticisers are petroleum derived, which is a non-renewable resource. Accordingly, this research aims to produce a natural-based plasticiser using clean production method. Epoxidised 2-ethylhexyl oleate (E-2-EHO) was produced through an esterification and epoxidation reaction between oleic acid and 2-ethyl hexanol; both reactions occur simultaneously, in the presence of hydrogen peroxide as oxygen donor in a solvent-free environment. Candida antarctica lipase (Novozym 435) was used as a cleaner biocatalyst. Several reaction parameters that affect the synthesis of (E-2-EHO) were analysed using response surface methodology based on full factorial central composite design for four variables. The maximum experimental conversion was 94.2% while the value of the predicted conversion was 95.3%. The operation conditions were a temperature of 65 °C, enzyme load of 4 wt%, alcohol-to-oleic acid molar ratio of 4:1, hydrogen peroxide-to-C=C molar ratio of 0.5:1, molecular sieve/g acid of 0.425 g and reaction time of 2 h. In addition, the plasticising effectiveness of (E-2-EHO) to substitute toxic DOP was studied. Comparison with conventional DOP highlighted that (E-2-EHO) had superior and significantly reduced glass transition temperature (tg) and improved mechanical properties. In the proposed study, (E-2-EHO) was proved to be an efficient substitute to DOP by replacing up to 80% of the total plasticiser. Moreover, the product yield obtained in a short time reaction along with the proven stability of Novozym 435 during operation both showed that this ecofriendly and maintainable alternative is favourable when used in large-scale applications.

In this paper, a 10th order nonlinear pharmacokinetics/pharmacodynamics (PK/PD) model was developed to evaluate the impact of Alzheimer's disease (AD) medications such as galantamine on β-amyloid (βA) aggregates and levels of acetylcholine (ACh) and choline in the presynaptic (compartment 1) and postsynaptic (compartment 2) neurons based on the choline leakage hypothesis. The development is performed by incorporating a one-compartment PD/PK model into the two-enzyme/two-compartment model built by Mustafa et al., (2012a,b). The interaction between medications and βA aggregates is formulated based on a 6-h single oral dose of 2.5-10 mg of drugs which indicated PK/PD changes similar to the experimental findings obtained by Goh et al., (2011). Enhanced cholinergic behavior was observed in terms of a reduction in βA aggregates’ concentrations and increase in the levels of ACh and choline in the pre-synaptic and postsynaptic neurons. The results indicate that therapeutic and pharmacological agents inhibiting βA aggregation represent a likely successful approach to develop future trials, new diagnostic techniques, and medications for AD. This study is helpful in developing experimental animal models to support the development of AD medications.

To assess contamination levels of the heavy metals, concentrations of Sc, Cr, Fe, Co and Zn in surface soils at various locations of southern part of Bangladesh were determined by Instrumental Neutron Activation Analysis (INAA) technique. In this study, concentrations of the Sc, Cr, Fe, Co and Zn elements in surface soil were found in the range of 2.56-16.7 μg/g, 12.9-112 μg/g, 6911-48642 μg/g, 2.59-22.7 μg/g and 37.7-322 μg/g, respectively. The measured concentrations were compared with average concentration of worldwide soil and observed that most of the samples contain much higher concentration of heavy metals except Cr and Fe. Analysis based on soil utilization type showed that the samples collected from roadside and residential area experienced much higher metal contamination than open area. A significant correlation was observed between Cr-Fe, Cr-Co, Cr-Sc, Fe-Co, Fe-Sc and Co-Sc.

Cutaneous viral warts are benign epidermal proliferations caused by human papillomaviruses (HPVs). Despite treatment, a significant proportion of warts fail to resolve, becoming recalcitrant. Vitamin A (retinol) may disrupt the interplay of HPV replication and epithelial cell differentiation, allowing normal tissue to replace warts. Circulating retinol-binding protein (RBP) concentrations highly correlate with retinol levels.We aimed at evaluation of serum RBP level in patients with recalcitrant cutaneous warts in order to assess its correlation with disease pathogenesis.Serum RBP level was measured by an ELISA technique in 50 patients with recalcitrant cutaneous warts and 30 apparently healthy controls.Serum RBP level was significantly lower in patients with recalcitrant warts than the control group (P0.001). However, it did not differ regarding different clinical parameters in studied patients (P0.05 each). RBP is a reliable biomarker for significant early detection and discrimination between patients and healthy controls (P0.001) at a cutoff value ≤1034.6 μg/ml, with sensitivity and specificity (100% each).Our results revealed that low serum RBP as a relatively cheap biomarker with high specificity and sensitivity is a reliable indicator of vitamin A (retinol) deficiency that may play a role in the pathogenesis of recalcitrant cutaneous warts among our studied patients.

Wearable electronics require flexible supercapacitors with specially fabricated electrode materials, i.e., foldable and freestanding. Although activated carbon is the most used electrode’s active material for aqueous supercapacitors, it is a challenge to pack the particulates into flexible electrodes. Typically, polytetrafluoroethylene binder and polymeric flexible substrate are used, rendering a large amount of inactive-material. Here, we successfully fabricated multiwalled carbon nanotube/activated-carbon (MWCNT-AC) freestanding sheet via a scalable surface-engineered tape-casting technique to be used as a flexible electrode for aqueous supercapacitors. Instead of focusing on improving MWCNTs as active materials, the sheets act as a conducting matrix that binds together the activated-carbon particulates. MWCNT-AC has a specific capacitance of 135.17 Fg−1 (123.9 Fg−1 after 1000 cycles) at 1 Ag−1 from − 0.8 to 0.2 V vs. Hg/HgO (in three-electrode cell).

The presence of impurities within multiwalled carbon nanotubes (MWCNTs) have major, but as-yet-unrecognized, effects on the electrochemical behavior of MWCNTs in vanadium redox flow batteries. We show that MWCNTs constitute a high-surface-area, electrically conductive, inactive carbon matrix that acts as a bridge between and a support for carbonaceous impurities that are highly active toward the VO2+/VO2+ redox couple. We use freestanding sheets of MWCNTs, either purified and subsequently not modified with impurities (pure) or purified and subsequently contaminated with carbonaceous impurities (impure), as electrodes to eliminate the need for a substrate and thus undesired mixed kinetics. Electrodes fabricated with pure MWCNTs show low activities; attributed to relatively inactive basal sites. In contrast, impure electrodes show high activities due to the increased number of defects and edge sites resulting from the presence of the impurities. Functionalization of pure MWCNTs surface with oxygen-containing groups substantially improve the activity of the electrodes. However, functionalization is not as effective when carbonaceous impurities are present. The carbonaceous impurities form a continuous debris layer over the nanotube fibers, which reduces the effect of the oxidation treatment. Our results indicate that the impurity content of MWCNTs should be considered in studies of their activity and functionalization.

Typically, multiwalled carbon nanotubes (MWCNTs) are drop-casted on the surface of the underlying carbon substrates; the outcome is a randomly distributed MWCNT layers leading to uncontrollable structure and unreproducible results. Additionally, we suspect that the electrochemical response is influenced by the primary carbon-based substrate. Herein, we propose the use of freestanding sheets of MWCNTs (buckypapers, BP electrodes) as electrode materials for vanadium redox flow batteries to directly probe the electrochemical activity of MWCNTs toward VO 2+ /VO 2 + and V 2+ /V 3+ redox couples; henceforth, eliminating the need for an underlying carbon substrate. The amount of surfactant and the sonication time used during the fabrication of BP electrodes affect their morphological characteristics and electrochemical performances. Although the electrical conductivity of BP electrodes decreases with increasing surfactant amount and increasing sonication time, the heterogeneous rate constants for both redox couples increase as these fabrication variables are increased, indicating that the performance-limiting process is not electrical conductivity but the number of active sites available for the electrochemical reaction. The standard heterogeneous rate constant of the BP electrode with the highest amount of surfactant is comparable to those of state-of-the-art electrodes. Our promising results call for more research on the potential use of BP electrodes in redox flow batteries.

Highly aligned titania (TiO 2 ) nanotube (NT) arrays have been grown on titanium sheet by using a self organized anodic oxidation method at different potentials (34–74 V) in a NH 4 F and ethylene glycol based electrolyte. Two sets of TiO 2 NT arrays have been fabricated with and without using cooling systems. Without cooling system, the solution temperature is increased from 25 °C (room temperature) to 63 °C with increase of anodization potential from 34 to 74 V. The temperature has been maintained to 25 °C by using water based cooling system. In both sets of samples, the pore diameter of TiO 2 NT arrays increases with increase of anodization potential. The maximum pore diameter has been (outer: 224 nm, inner: 172 nm) achieved with TiO 2 NT arrays (at 74 V) without using cooling system. The photocatalytic activity of the TiO 2 NT arrays is evaluated by the decomposition of methanol by the use of Fourier transform infrared spectrophotometer. The TiO 2 NT (at 44 V) sample has been fabricated without using cooling system, which shows the higher photocatalytic activity than the sample at other potentials. Using cooling system, the TiO 2 NT (at 54 V) sample shows the higher photo-decomposing property than the sample at other potentials. The TiO 2 NT (at 54 V) sample with cooling system shows the higher rate (photocatalytic activity) constant ( k = 0.0216) than the TiO 2 NT (at 44 V) sample without using cooling system ( k = 0.0186). The photocatalytic activity has been correlated with the nanostructural variation of TiO 2 NT arrays at different potentials without (self-grown solution temperature) and with water based cooling systems.

Although free-standing sheets of multiwalled carbon nanotubes (MWCNT) can provide interesting electrochemical and physical properties as electrodes for redox flow batteries, the full potential of this class of materials has not been accessible as of yet. The conventional fabrication methods produce sheets with micro-porous and meso-porous structures, which significantly resist mass transport of the electrolyte during high-current flow-cell operation. Herein, we developed a method to fabricate high performance macro-porous carbon nano-foam free standing sheets (Puffy Fibers, PF), by implementing a freeze-drying step into our low cost and scalable surface-engineered tape-casting (SETC) fabrication method, and we show the improvement in the performance attained as compared with a MWCNT sheet lacking any macro pores (Tape-cast, TC). We attribute the higher performance attained by our in-lab fabricated PF papers to the presence of macro pores which provided channels that acted as pathways for electrolytic transport within the bulk of the electrode. Moreover, we propose an electrolytic transport mechanism to relate ion diffusivity to different pore sizes to explain the different modes of charge transfer in the negative and the positive electrolytes. Overall, the PF papers had a high wettability, high porosity, and a large surface area, resulting in improved electrochemical and flow-cell performances.

Clinically approved iron chelators are effective in decreasing significant transfusional iron accumulation. Starch-Deferoxamine (S-DFO), a novel high molecular weight iron chelator, was produced to increase binding capacity to iron and reduce toxicity. Although its efficacy was established in one small cohort clinical trial, its potential adverse effect was not adequately addressed. We utilized zebrafish model to assess S-DFO toxicity using following assays: mortality, teratogenicity, hatching rate, tail flicking, Acridine Orange staining for apoptosis detection, o-dianisidine staining for hemoglobin synthesis, and the level of Hsp70 as a general stress indicator. Embryos were exposed to different concentrations of S-DFO, Zinc Oxide nanoparticle (ZnO) (positive control), along with untreated control (UC). S-DFO showed no significant mortality nor deformities at all tested concentrations (0.0-1000 μM). Thus, the LC50 is expected to >1000 μM. 100 μM S-DFO treatment did not affect embryo development (as judged by hatching rate); neuromuscular activity (as judged by tail flicking); and hemoglobin synthesis. Neither apoptosis, nor increase in Hsp70 level was noticed upon S-DFO treatment. Our assays demonstrate that S-DFO does not induce cellular or biochemical stress and has no adverse effect on organ development of zebrafish embryos, suggesting its safe use as an iron chelator. Funding information: Qatar University, Grant/Award Number: University Internal Grant/QUUG-CAS-DHS-15\16-21.

For more than 50 years, artificial joints are fastened efficiently by bone cements. Bone cements play an important role in the elastic zone. In human hip joint, about ten to twelve times of the body weight acts upon the hip joint. This gives rise to the need of the bone cement to absorb the forces acting upon the human hip joint. Plexiglas, which is Poly Methyl Methacrylate (PMMA) is the material of choice for obtaining bone cements. Three methods are conducted to produce PMM4; namely, the emulsion polymerization, solution polymerization and bulk polymerization. From these methods; in-situ and in-vivo extremely exothermic reactions of free radical bulk polymerization are used to produce PMM4 bone cements. Radical polymerization gives atactic and amorphous PMM4. Also, aseptic loosening is caused by residual monomer which remains unreacted in the body. Free radical polymerization models can describe the bone cement production effectively and are used for quantitative analysis of its synthesis. In this research, bone cement production is mathematically investigated based on multi-cell reactor. Solubility of the pre-polymer powder in the liquid monomer has shown to be the most important variable during the preparation process and that it should be tuned to control the real operation of bone cement production.

In this paper, the effect of β-amyloid (Aβ) oligomer aggregates on Acetylcholine (ACh) neurocycle of human brain and its relation to Alzheimer's disease (AD) are investigated through a two-enzyme/two-compartment (2E2C) diffusion mathematical model whereby compartment 1 represents the presynaptic neuron while compartment 2 represents the postsynaptic neuron and postsynaptic cleft. It is found that Aβ aggregates induce choline leakage from the presynaptic neurons (compartment 1) leading to a reduction in choline content in both compartments. The lowering in choline levels in each compartment is promoted with the increase in the inlet Aβ oligomers which create more channels and pores in the presynaptic membrane. In addition, it is found that both the rates of ACh synthesis and hydrolysis were affected negatively by the increase in the levels of Aβ oligomers. Furthermore, the levels of ACh in both compartments decreased while the level of Aβ oligomers increased. However, the acetate concentration in compartment 1 increased but the acetate level in compartment 2 decreased. These results are compatible with the low levels of both ACh and choline in the neuron tissues of Alzheimer's disease (AD) brains through choline leakage hypothesis. Also, the model shows the significant effect of inhibiting Aβ aggregation as a promising therapeutic mechanism to mitigate cholinergic diseases. The model suggests that Aβ oligomers exert neuroinflammatory and toxic effect against the ACh neurocycle. The paper suggests that development of therapeutic agents capable of inhibiting toxic Aβ aggregations and maintaining choline substrates in neurons is necessary to provide a neuroprotective effect, cholinergic transmission, and maintain reasonable levels of ACh.

This work was carried out to investigate the comparative effects of phosphorus and boron doing in vapor–liquid–solid (VLS) growth. Doped Si microneedles were grown by VLS mechanism at the temperature of 700 °C or less using Au as the catalyst. VLS growth using in-situ doping with the mixed gas of Si2H6 and PH3 produced phosphorus doped n-Si microneedles at Au dot sites, whereas, the mixed gas of Si2H6 and B2H6 produced boron doped p-Si microneedles. The variation of growth rate, diameter, resistivity, impurity concentration and carrier (electron, hole) mobility of these n-Si and p-Si microneeedles were investigated and compared with the variation of dopant gas (PH3 or B2H6) flow, with a fixed flow of Si gas (Si2H6). This comparative study shall be helpful while fabricating devices by growing n-Si and p-Si microneedles one above another by multistep (2-step or 3-step) VLS growth.

In Faranah Province (Guinea), the ratio of supply and demand of corn is approximately 1:2. The production is low and the deficit is covered by maize importation. This study was initiated in order to improve corn production by evaluating the effects of increasing doses of mineral fertilizers on the yield and economic profitability of corn. The experiment was conducted on a farm in Kamedankoude in a split plot with three replicates. Treatments included two varieties of maize (Perta and Kilissi113) and five doses of chemical fertilizers (D0=unfertilized control, D1=300 kg NPKS+200 kg urea • hm−2; D2=400 kg NPKS+800 kg urea • hm−2; D3= 200 kg NPKS+400 kg urea • hm−2 and D4=500 kg NPKS+600 kg urea • hm−2). The results showed that all the agronomic parameters increased with increasing dose of fertilizers, except for the number of ears per plant. The two varieties of corn tested produced similar yields. However, the profitability of mineral fertilizers decreased with increased doses and with value/cost ratio of 3. We recommended a mineral fertilizer dose of 300 kg NPKS + 200 kg urea. The high prices of mineral fertilizers were often barriers to intensive maize cultivation, especially for low-income farmers. This study was a contribution to rational fertilization and adapted the socio-economic conditions of the region, with the background knowledge that most farmers in the regions earned low incomes.

BACKGROUND Chemical hair straightening becomes popular for managing frizzy hair. Keratin in hair care products can penetrate the cortex of the hair fiber improving the mechanical properties of damaged fibers and promote a surface coating that prevents or decreases water diffusion through the hair fibers. This may have beneficial effects on the hair structure; however, the side effects and safety of this treatment have not yet been completely evaluated. AIMS To evaluate the efficacy and safety of chemical hair straightening application on the hair shaft. SUBJECTS AND METHODS Thirty female subjects older than 15 years with hair curl types III-V were included. They were subjected to full history taking and dermatologic examination of hair and scalp prior to and after application of chemical hair straightener. To detect the presence of transverse fissures, split ends, or possible side effects, the distal 3-5 cm of hair fibers were cut before and after the last step of chemical hair straightener application for light microscopy examination. Three randomly selected samples were examined by transmission electron microscope. RESULTS Chemical hair straightening led to significant decrease in the degree of hair curl and increased hair smoothness and shine. The treated hair fibers showed significant repair of the broken cuticle (P

Thalassemia is the most common genetically inherited blood disorder arising from a defect in hemoglobin production, resulting in ineffective erythropoiesis and severe hemolytic anemia. While transfusion therapy corrects the anemia, it gives rise to secondary iron overload. Current iron chelation therapy performed using deferoxamine, and the efficiency of this drug was demonstrated here using the zebrafish animal model. Zebrafish larvae were exposed for three days to iron [100 μM ferric ammonium citrate; 3-6 days post fertilization (dpf)]. Then, iron treated larvae were exposed to 100 μM deferoxamine for three days (6 - 9 dpf). Total tissue iron concentration in the whole larvae, assessed by three different assays; inductively coupled plasma mass spectrometry, colorimetry (spectrophotometry), and microscopy using iron staining followed by imaging and quantification. The three assays showed that iron treatment alone resulted in a significant increase in total iron. Deferoxamine treatment of the iron-loaded zebrafish larvae showed a significant decrease in total iron concentration. This study presented a clear evidence of the effectiveness of zebrafish larvae to use as a tool to study iron overload and open the door for studying the efficiency of potential new iron chelating compounds other than commercially available ones. This article is protected by copyright. All rights reserved.

Tandem solar cell provides an effective way to improve power conversion efficiency of organic solar cell by combining two or more organic solar cells. Each cell has different absorption maximum and width so it provides the amenities of using the photon energy more effectively. Due to the limited absorption band of organic materials, single junction organic solar cells suffer from low efficiency. Here, we demonstrate the performance of single layer devices based on the solution of carrier continuity equation in MATLAB. Polymers P3HT:PCBM, pBBTDPP2:PCBM and PCDTBT:PCBM provide power conversion efficiency of 3%, 3.15% and 6.2% respectively. Hence series connected tandem cell P3HT:PCBM as front cell and pBBTDPP2:PCBM as rear cell is designed to achieve higher efficiency where the proposed model gives the power conversion efficiency of 6%. A major back through came when the front cell is replaced by PCDTBT:PCBM solar cell in the device configuration which provides the power conversion efficiency of 8.8%, till now the maximum efficiency for organic solar cell.

Although important, very little has been demonstrated in the literature to experimentally demonstrate the effects of porosities and pore size on the evaporation flux in polymeric membranes. Additionally, we suspect that a batch-mode setup, i.e., stagnant water, could cause a build-up of heat in the system, influencing the evaporation mass-flux mechanism, and jeopardizing the ability to attain a real correlation between evaporation and effects of pore characteristics. Herein, we fabricate polyvinylidene fluoride membranes containing variable amounts of a Fumed Silica additive to achieve membranes with variable properties, and we investigate the change in the performance of the solar-assisted thin-film evaporation utilizing an in-house built continuous flow evaporation setup (to avoid heat build-up effects in the bulk of the water and demonstrate a continuous flow system). Our membrane design approach had two important advantages: (1) the achievement of similar heat transfer and solar absorbance properties and (2) the achievement of variable pore sizes and volume porosities. We show that the mass flux increased as the mean pore size decreased, indicating that the mode of mass transfer occurred due to the thin-film region of the meniscus from the small fluid velocities near the interface, and we attribute the results to the increase in the capillary pumping effects through the mesoporous channels as they get thinner.

A theoretical analysis shows that polymers interacting with particles in a shear flow experience enhanced streamwise stretch that grows in amplitude and spatial extent with increasing Deborah number. This results in shear thickening of the viscosity and first normal stress coefficient of a particle suspension in a Boger fluid.

Usually packed red blood cells (pRBCs) require specific conditions in storage procedures to ensure the maximum shelf life of up to 42 days in 2–6°C. However, molecular and biochemical consequences can affect the stored blood cells; these changes are collectively labeled as storage lesions. In this study, the effect of prolonged storage was assessed through investigating morphological changes and evaluating oxidative stress. Samples from leukodepleted pRBC in SAGM stored at 4°C for 42 days were withdrawn aseptically on day 0, day 14, day 28, and day 42. Morphological changes were observed using scanning electron microscopy and correlated with osmotic fragility and hematocrit. Oxidative injury was studied through assessing MDA level as a marker for lipid peroxidation. Osmotic fragility test showed that extended storage time caused increase in the osmotic fragility. The hematocrit increased by 6.6% from day 0 to day 42. The last 2 weeks show alteration in the morphology with the appearance of echinocytes and spherocytes. Storage lesions and morphological alterations appeared to affect RBCs during the storage period. Further studies should be performed to develop strategies that will aid in the improvement of stored pRBC quality and efficacy. This study was supported by ‘Qatar University student grant QUST-CAS-FALL-14\15-23’.The authors are grateful to Dr. Zeyd Merenkov from the Blood Bank of Hamad Medical Cooperation for assisting in this research. The authors also appreciate the efforts of Mr. Essam Attia at Qatar University Central Laboratory for assisting with the electron microscopy. The authors also acknowledge the support of Dr. Gheyath K. Nasrallah’s laboratory to use some of the equipment in his laboratory, at Biomedical Research Centre of Qatar University.

The temperature-dependent anomalous optical properties of AlInGaN quaternary alloys have been studied using Monte Carlo simulation of phonon-assisted exciton hopping. The simulation results agreed well with the experimental photoluminescence linewidths and the peak energy positions while considering the additional inhomogeneous broadening with band potential fluctuation and the phonon-induced radiative lifetime of the exciton. The incorporation of band-gap shrinkage into the conventional Monte Carlo simulation shows a good fit for the photoluminescence peak energy positions in AlInGaN quaternary alloys with temperature-induced experimental unusual behavior (redshift-blueshift-redshift). The W-shaped temperature-dependent inhomogeneities are observed for the PL linewidths. The temperature-induced S-shaped photoluminescence band peaks and W-shaped linewidth have been attributed to the change of exciton dynamics due to the indium aggregated potentials and the exciton localization effects. These results could be important to understanding the realistic optical properties of AlInGaN quaternary alloy-based electronic and optoelectronic devices.

The effect ofβ-amyloid aggregates on activity of choline acetyltransferase (ChAT) which is responsible for synthesizing acetylcholine (ACh) in human brain is investigated through the two-enzyme/two-compartment (2E2C) model where the presynaptic neuron is considered as compartment 1 while both the synaptic cleft and the postsynaptic neuron are considered as compartment 2 through suggesting three different kinetic mechanisms for the inhibition effect. It is found that the incorporation of ChAT inhibition byβ-amyloid aggregates into the 2E2C model is able to yield dynamic solutions for concentrations of generatedβ-amyloid, ACh, choline, acetate, and pH in addition to the rates of ACh synthesis and ACh hydrolysis in compartments 1 and 2. It is observed that ChAT activity needs a high concentration ofβ-amyloid aggregates production rate. It is found that ChAT activity is reduced significantly when neurons are exposed to high levels ofβ-amyloid aggregates leading to reduction in levels of ACh which is one of the most significant physiological symptoms of AD. Furthermore, the system of ACh neurocycle is dominated by the oscillatory behavior when ChAT enzyme is completely inhibited byβ-amyloid. It is observed that the direct inactivation of ChAT byβ-amyloid aggregates may be a probable mechanism contributing to the development of AD.