ZnCl2 Concentration Research Articles

Technical and Economic approach of bioethanol production from nanofiltration of biomass chemical hydrolysis solutions

The effects of pH, transmembrane pressure, and ZnCl2 concentration on the purification of glucose from solution through nanofiltration were investigated. The solutions used contained ZnCl2 and glucose in concentrations as high as 180 and 80 g/L, respectively. A high concentration of glucose was discovered in the retentate as the product, and ZnCl2 was filtered out into the permeate; the highest separation factor achieved was 10. The derivative Hagen–Poiseuille equation was applied to model the experimental data and calculate the effective thickness and pore radius of the membranes used. Moreover, an integrated multiple-nanofiltration system was designed to process a real bagasse hydrolysis solution. The fermentability of the purified sugar solution was confirmed, with an 82% total alcohol yield obtained. The multiple-nanofiltration system is both economically and environmentally sustainable for the production of bioethanol through chemical hydrolysis of biomass.

Further aspects of Toxoplasma gondii elimination in the presence of metals.

Toxoplasma gondii, the etiological agent of toxoplasmosis, infects nucleated cells and then resides and multiplies within a parasitophorous vacuole. For this purpose, the parasite secretes many virulence factors for the purpose of invading and subverting the host microbicidal defenses in order to facilitate its survival in the intracellular milieu. Essential metals are structural components of proteins and enzymes or cofactors of enzymatic reactions responsible for these parasitic survival mechanisms. However, an excess of non-essential or essential metals can lead to parasite death. Thus, infected host cells were incubated with 20μM ZnCl2 in conjunction with 3μM CdCl2 or HgCl2 for 12h in order to investigate cellular events and organelle damage related to intracellular parasite death and elimination. In the presence of these metals, the tachyzoites undergo lipid uptake and transport impairment, functional and structural mitochondrial disorders, DNA condensation, and acidification of the parasitophorous vacuole, thus leading to parasite death. Additional research has suggested that lysosome-vacuole fusion was involved in parasite elimination since acid phosphatases were found inside the parasitophorous vacuole, and vacuoles containing parasites were also positive for autophagy. In conclusion, low concentrations of CdCl2, HgCl2, and ZnCl2 can cause damage to Toxoplasma gondii organelles, leading to loss of viability, organelle death, and elimination without causing toxic effects to host cells.

Surface modification of ZnO nanostructured film prepared by hot water oxidation

ZnO nanostructured films with tunable morphology were fabricated using hot water oxidation of etched Zn foils at 90 °C under varying solution conditions. At high pH, coarse ZnO nanostructured film, consisting of short nanorods, was produced. When the pH was lowered to about 3.8, no ZnO nanostructures were produced. On the other hand, a 1D-2D composite ZnO nanostructured film, consisting of nanorods and nanosheets, was formed by adding 0.05 to 0.20 M ZnCl2 during hot water oxidation. Increasing the ZnCl2 concentration further produced simonkolleite platelets instead of ZnO. The as-synthesized ZnO nanostructured films showed excellent wettability with static water contact angle ranging from 0 to 22.37°. Surface modification with stearic acid and 1-hexadecene under UV illumination effectively altered the wetting properties of the ZnO nanostructured films, resulting to superhydrophobic surfaces with static water contact angles of 149.90–156.62° and contact angle hysteresis as low as 1.63°. The 1-hexadecene-treated pencil-like ZnO nanorods achieved the highest water contact angle and retained its superhydrophobicity even after mechanical abrasion.

Chlorophyll extraction from suji leaf (Pleomele angustifolia Roxb.) with ZnCl2 stabilizer.

Suji (Pleomele angustifolia Roxb.) leaves are a prominent source of chlorophyll and well-known for their ability to produce green color for food ingredients. However, chlorophyll is suspectible to color degradation at high temperature. Color degradation occurred because porphyrin loses magnesium in its ring and it can be avoided by adding zinc. The aim of this work was to investigate the combined effect of independent variables on chlorophyll extraction process using ZnCl2 as a stabilizer. Suji leaves were blanched with boiling water for 2min, Zn-chlorophyll synthesis was done by varying concentration of ZnCl2, Zn-chlorophyll extraction with ethanol, and UV-Vis spectrophotometry analysis of the final extracted solutions. A full three-level factorial design under response surface methodology was used to obtain the optimum condition of extraction process. The experimental data were analyzed by analysis of variance and fitted with second order polynomial equation. The coefficient of determination (R2) was found to be 81.99%. The optimum operating conditions were obtained at pH 7, ZnCl2 concentration of 700ppm and temperature of 85°C with desirability value of 1.0000. At the optimum conditions, the total chlorophyll content (TCC) was found to be 47.2975mg/100g fresh weight.

Oxidative stress and response of antioxidant system in Nostoc muscorum exposed to different forms of Zinc

Abstract Objective Present study aims to evaluate oxidative stress-mediated toxicity mechanisms of nano-ZnO (N-ZnO) compared to ZnCl2 and bulk-ZnO (M-ZnO), using cyanobacterium as a toxicity assessment tool. Methods Nostoc muscorum was used as a test organism and the experiments were performed in parallels after treated with 2–128 μM of N-ZnO, M-ZnO, and ZnCl2. Results Low concentrations of ZnCl2 (2–8 μM) and N-ZnO (16–32 μM) led to a significant increase in the carotenoids, which could be ascribed to its role as an antioxidant, whereas higher concentrations were inhibitory to the photosynthetic pigments. Enhanced activities of superoxide dismutase (SOD), peroxidase (POD) and accelerated lipid peroxidation depicted significant accumulation of superoxide and peroxide radicals in N. muscorum exposed to N-ZnO and ZnCl2. The non-enzymatic antioxidants such as proline and total phenols also showed enhanced accumulations up to 16 and 64 μM of ZnCl2 and N-ZnO treatment, respectively. Conclusion Our results for the very first time depicted the significant accumulation of stress biomarkers in N. muscorum in response to deleterious effects of oxidative stress caused by N-ZnO, ZnCl2, and M-ZnO. Present results revealed varying levels of toxicity of various forms of zinc, which decreased in an order of ZnCl2>N-ZnO>M-ZnO.

Biosynthesis of TiO2 and ZnO nanoparticles by Halomonas elongata IBRC-M 10214 in different conditions of medium.

Introduction: In the recent years, green synthesis is a novel method without some disadvantages of physical and chemical methods. In this approach, bacteria, archaebacteria, fungi, and plants may be applied without utilizing toxic and expensive materials for metal nanoparticles (MNPs) preparation. Methods: In this study, we used Taguchi method to obtain optimum conditions in titanium dioxide and zinc oxide nanoparticle (NPs) biosynthesis by Halomonas elongata IBRC-M 10214. Design and analysis of Taguchi experiments (an orthogonal assay and analysis of variance [ANOVA]) carried out by the Qualitek-4 software. Effects of TiO(OH)2, incubation temperature, and culturing time for synthesis of TiO2 NPs as well as ZnCl2 concentration, glucose concentration, and incubation temperature for the preparation of ZnO NPs were evaluated as the controllable factors with 3 levels. Characterization of TiO2 and ZnO NPs were determined by UV-Vis spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and dynamic light scattering (DLS) analysis. Also, the antimicrobial properties of these NPs were investigated based on agar diffusion assay of NPs dispersed in batch cultures using Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 43300 as multidrug-resistant (MDR) bacteria. Results: It was evaluated that TiO2 and ZnO NPs had respectively average diameter sizes of 104.63±27.75 and 18.11±8.93 nm with spherical shapes. In contrast to the TiO2 NPs without antibacterial activity, the ZnO NPs had antibacterial effects at 0.1 and 0.01 M of (ZnCl2). Conclusion: The ZnO NPs have the antibacterial effect that can be operative in the medicinal aspect for fighting against prominent MDR bacteria such as E. coli ATCC 25922 and S. aureus ATCC 43300. In total, this study presents a simple method in the biosynthesis of TiO2 and ZnO NPs with low the expense, eco-friendly, and high productivity properties.

Characterization of the zinc-induced Shank3 interactome of mouse synaptosome

Variants of the SHANK3 gene, which encodes a core scaffold protein of the postsynaptic density of excitatory synapses, have been causally associated with numerous brain disorders. Shank3 proteins directly bind zinc ions through their C-terminal sterile α motif domain, which enhances the multimerization and synaptic localization of Shank3, to regulate excitatory synaptic strength. However, no studies have explored whether zinc affects the protein interactions of Shank3, which might contribute to the synaptic changes observed after zinc application. To examine this, we first purified Shank3 protein complexes from mouse brain synaptosomal lysates that were incubated with different concentrations of ZnCl2, and analyzed them with mass spectrometry. We used strict criteria to identify 71 proteins that specifically interacted with Shank3 when extra ZnCl2 was added to the lysate. To characterize the zinc-induced Shank3 interactome, we performed various bioinformatic analyses that revealed significant associations of the interactome with subcellular compartments, including mitochondria, and brain disorders, such as bipolar disorder and schizophrenia. Together, our results showing that zinc affected the Shank3 protein interactions of in vitro mouse synaptosomes provided an additional link between zinc and core synaptic proteins that have been implicated in multiple brain disorders.

MgCl2 and ZnCl2 promote human umbilical vein endothelial cell migration and invasion and stimulate epithelial-mesenchymal transition via the Wnt/β-catenin pathway.

Previous studies have demonstrated that magnesium and zinc ions promote the migration and epithelial-mesenchymal transition (EMT) of cancer/endothelial cells. However, the impact of MgCl2 and ZnCl2 on the migration, invasion and EMT of human umbilical vein endothelial cells (HUVECs) and the involved mechanisms remain unclear. In the present study, HUVECs were incubated with various doses of MgCl2 and ZnCl2. The optimum concentrations of MgCl2 and ZnCl2 were selected by MTT assay. The migration and invasion capabilities of HUVECs were analyzed by Transwell assays. Subsequently, the expression of matrix metalloproteinase (MMP)-2 and MMP-9 mRNA and protein were determined by reverse transcription-quantitative polymerase chain reaction, western blotting and ELISA. MMP-2 and MMP-9 activities were measured by gelatin zymography. Immunofluorescence staining was performed to investigate cytoskeletal dynamics using Acti-stain™ 488 Fluorescent Phalloidin. Subsequently, the expression of EMT-related markers at the mRNA and protein levels and the activation of Wnt/β-catenin signaling were analyzed. The results identified increases in MMP-2 and MMP-9 expression and activity, indicating that MgCl2 and ZnCl2 promoted HUVEC migration and invasion. In addition, MgCl2 and ZnCl2 treatment induced cytoskeleton remodeling and stimulated EMT via activation of the Wnt/β-catenin signaling pathway, characterized by a decrease in E-cadherin and increases in N-cadherin, vimentin and Snail. These results suggest that MgCl2 and ZnCl2 may enhance the migration and invasion capabilities of HUVECs and promote EMT through the Wnt/β-catenin pathway.

Adsorption Study of the Removal of Copper (II) Ions using Activated Carbon Based Canarium Schweinfurthii Shells Impregnated with ZnCl2

<p>The adsorption of Cu2+ions on activated carbon based canarium schweinfurthii impregnated with ZnCl2 was studied. The shells of canarium schweinfurthii were impregnated with ZnCl2 at varying ZnCl2 concentrations, temperature, residence time while keeping the heating rate fixed at 10 °C / min and the ratio of impregnation of 1:1. The activated carbon with the highest surface area in term of iodine number of 860,817 mg/g, the highest methylene blue of 741,6 mg/g and 74,66 % of yield of carbon was obtained at 650 °C, 60 % ZnCl 2 and 30min. From the batch adsorption studies, the equilibrium time was found to be 40 min. Analysis of equilibrium isotherm models revealed a good correlation of the experimental data with the Tempkin (R 2 = 0.909) model. This confirms a high affinity of the activated carbon for Cu 2+ ions on the heterogeneous surface. The value of energy obtained from the Tempkin model was 60,606 J/mol and the presence of pics between 487 cm-1 to 871 cm-1 indicating that physisorption and chemisorption were taking place during this sorption. The pseudo-second order kinetics(R 2 = 0.999) governs the adsorption of Cu2+ions on this activated carbon.</p>

Efficient coproduction of gluconic acid and xylonic acid from lignocellulosic hydrolysate by Zn(II)-selective inhibition on whole-cell catalysis by Gluconobacter oxydans

With Zn(II)-selective inhibition on the whole-cell catalysis of Gluconobacter oxydans NL71, gluconic acid and xylonic acid were coproduced efficiently from the hydrolysate of corn stover. Further metabolism of gluconic acid to the by-product 2-ketogluconic acid was prevented by addition of 10g/L ZnCl2. Remarkably, yields of 93.91% of gluconic acid and 93.36% of xylonic acid were obtained with the supplement of ZnCl2 in the synthetic medium, without by-product production. After optimization of the concentrations of ZnCl2 and inocula of the strain, maximum amounts of gluconic acid and xylonic acid were coproduced at titers of 63.01g/L and 33.81g/L, with an overall utilization of 100% of the sugars in the enzymatic hydrolysate of corn stover. The results showed execution of our objective to prove this novel bioconversion method for simultaneously producing gluconic acid and xylonic acid, which would benefit subsequent studies on the comprehensive utilization of lignocellulosic materials.

Nitrogen doped and hierarchically porous carbons derived from chitosan hydrogel via rapid microwave carbonization for high-performance supercapacitors

We have demonstrated a rapid and facile approach for preparing nitrogen doped and hierarchically porous carbons (NHPCs) using renewable chitosan as precursor via microwave carbonization in only 10 min. In microwave carbonization, ZnCl2 impregnated in chitosan hydrogel serves as microwave absorber, chemical activation agent and porogen. The porous textures of NHPCs can be modulated by altering the concentration of ZnCl2 in chitosan hydrogel. The optimal NHPC possesses a high nitrogen content of 9.4 wt% along with high specific surface area of 1170 m2 g−1, pore volume of 1.32 cm3 g−1 and mesopore ratio of 78%. Electrochemical performance suggests that a high specific capacitance of 435 F g−1 is achieved at 0.2 A g−1 in three-electrode system with 6 M KOH as electrolyte. The as-assembled symmetrical supercapacitor exhibits a high energy density of 9.4 Wh kg−1 at the power density of 50 W kg−1 and remarkable retention ratio of 79.8% at a high power density of 2500 W kg−1 in 6 M KOH. Moreover, the supercapacitor displays a long cycle life with the capacitance retention of nearly 100% over 10000 cycles. Conversion of chitosan hydrogel to NHPCs via rapid microwave carbonization represents a promising route for preparing carbon materials for high-performance supercapacitors.

Optimization of a novel sequential alkalic and metal salt pretreatment for enhanced delignification and enzymatic saccharification of corn cobs

This study presents a sequential sodium phosphate dodecahydrate (Na3PO4·12H2O) and zinc chloride (ZnCl2) pretreatment to enhance delignification and enzymatic saccharification of corn cobs. The effects of process parameters of Na3PO4·12H2O concentration (5–15%), ZnCl2 concentration (1–5%) and solid to liquid ratio (5–15%) on reducing sugar yield from corn cobs were investigated. The sequential pretreatment model was developed and optimized with a high coefficient of determination value (0.94). Maximum reducing sugar yield of 1.10±0.01g/g was obtained with 14.02% Na3PO4·12H2O, 3.65% ZnCl2 and 5% solid to liquid ratio. Scanning electron microscopy (SEM) and Fourier Transform Infrared analysis (FTIR) showed major lignocellulosic structural changes after the optimized sequential pretreatment with 63.61% delignification. In addition, a 10-fold increase in the sugar yield was observed compared to previous reports on the same substrate. This sequential pretreatment strategy was efficient for enhancing enzymatic saccharification of corn cobs.

Comparison of a two-stage and a combined single stage salt-acid based lignocellulosic pretreatment for enhancing enzymatic saccharification

This study compares the optimization of combined and two-stage salt-acid pretreatment technique for efficient delignification, hemicellulose removal and enhancement of sugar yield from sugarcane leaf waste. The effect of process parameters ZnCl2 concentration (1M–5M), H2SO4 concentration (0.10–2.0%, v/v) and solid loading (5–15%, w/v) on the reducing sugar yield were investigated. The developed models showed coefficients of determination (R2) >0.94. The two-stage pretreatment under optimal conditions of 3.32M ZnCl2, 1.84% (v/v) H2SO4, and 9.26% (w/v) solid loading gave 0.293g/g reducing sugar, a 9% improvement compared to the optimized combined pretreatment. SEM and FTIR analysis showed major structural changes in the pretreated biomass. Significant lignin and hemicellulose removal was observed with the two-stage pretreatment. The optimized two-stage pretreatment also showed 66% and 194% yield improvement on sorghum leaves and Napier grass respectively. These results indicate that a two-stage ZnCl2-H2SO4 pretreatment can significantly enhance enzymatic saccharification of lignocellulosic waste.

Effect of Additives on Electrodeposited Aluminum Alloy Films By Using Dimethylsulfone As an Organic Solvent

Aluminum alloy films have been electroplated by using Dimethylsulfone (DMSO2) as an organic solvent. Several kinds of additives, Zinc (Zn), Iron (Fe), Nickel (Ni), Cobalt (Co), and Manganese (Mn), have been prepared. In this paper, the Aluminum-Zinc (Al-Zn) alloy films have been mainly focused. Aluminum Chloride, AlCl3, were used as aluminum source. Plating bath composition, mol ratio between DMSO2 to AlCl3 was 67:33. The alloy films were electroplated by using electrochemical measurement equipment, Hz-5000 made by Hokuto Denko Co. Ltd., and Al wire whose diameter was 1mm was used as a reference electrode. Aluminum plate (50mm x 10mm) was used as a counter electrode, both Cu (10mm x 5mm) and Ni (8mm x 6.2mm) substrates were used. Bath temperature was adjusted at 150oC by hot plated. Surface morphology was observed by scanning electron spectroscopy (SEM), VE-8800 made by KEYENCE Co. Ltd., film composition was determined by energy dispersive X-ray spectrometry, JCM-6000 made by JEOL Co. Ltd., and film structure was investigated by X-ray diffraction, RINNT2200 made by Rigaku Co. Ltd. Figure 1 showed effect of ZnCl2 concentration on Zn content of the Al-Zn films plated by three different current density, 3.0, 6.0 and 10.0 A/dm2. There were three regions, from 0 to 0.25 mol%, from 0.25 to 0.6 mol% and from 0.6 to 1.0 mol%. The zinc content gradually increased with increasing ZnCl2 concentration and reached at constant values less than 20 at% in the region from 0 to 0.25 mol% ZnCl2 concentration. On the other hand, the zinc content abruptly increased with increasing ZnCl2 concentration in the region from 0.25 to 0.6 mol% ZnCl2 concentration and the Zn content reached more than 90 at%. In the third region, the Zn content gradually increased with increasing ZnCl2 concentration in the region from 0.6 to 1.0 mol% ZnCl2 concentration and the Zn content reached almost 100 at%. The zinc content in the Al-Zn alloy films showed strong dependence on ZnCl2 concentration in the baths. However, the current density showed very little dependence on ZnCl2 concentration in the baths. There was one apparent result, Zn content in the Al-Zn alloy films plated by 6.0 A/dm2 current density showed higher values than those plated by 10.0 A/dm2 current density. The films plated by 3.0 A/dm2 current density showed maximum Zn content in the region less than 0.15 mol% ZnCl2 concentration and showed minimum Zn content in the region from 0.4 to 0.5 mol% ZnCl2 concentration. Therefore, zinc chloride concentration in the bath was more important factor than current density. Following results were obtained. The zinc-aluminum alloy films which were plated from the bath with low ZnCl2 concentration showed metallic luster, however, the alloy films which were plated at higher ZnCl2 concentration showed no metallic luster and showed gray. By scanning electron microscopy measurement, there were dendrite morphology for certain ZnCl2 concentration regions which were affected by current density. On the whole, the alloy films were composed with fine grains. By X-ray diffraction measurement, peak shifts, due to Al lattice, to lower angle side were observed. These results showed that the Zn atoms substituted Al atoms and formed a substitutional solid solution. There are three regions of the crystal structure change. First, degree of aluminum crystallization was deteriorated by codeposition of zinc. Second, alloy films which were plated at 3.0 and 10.0 A/dm2 current density showed alloy structure, however alloy films which were plated by 6.0 A/dm2 current density showed phase separation, Al and Zn. Third, zinc phase was matrix and Al grains were segregated in the Al matrix. Figure 1

Characterization of zinc stress response in Cyanobacterium Synechococcus sp. IU 625

The ability of cyanobacteria to survive many environmental stress factors is a testament to their resilience in nature. Of these environmental stress factors, overexposure to zinc is important to study since excessive zinc intake can be a severe hazard. Zinc toxicity in freshwater has been demonstrated to affects organisms such as invertebrates, algae and cyanobacteria. Cyanobacteria which possess increased resistance to zinc have been isolated. It is therefore important to elucidate the mechanism of survival and response to determine what factors allow their survival; as well as any remediation implications they may have. To characterize the effects of zinc in freshwater cyanobacteria, we investigated the response of Synechococcus sp. IU 625 (S. IU 625) over 29days to various concentrations (10, 25, and 50mg/L) of ZnCl2. S. IU 625 was shown to be tolerant up to 25mg/L ZnCl2 exposure, with 10mg/L ZnCl2 having no outward physiological change and 50mg/L ZnCl2 proving lethal to the cells. To determine a potential mechanism Inductive Coupled Plasma–Mass Spectrometry (ICP–MS) and RNA-seq analysis were performed on zinc exposed cells. Analysis performed on days 4 and 7 indicated that response is dose-dependent, with 10mg/L ZnCl2 exhibiting nearly all zinc extracellular, corresponding with upregulation of cation transport response. Whereas the 25mg/L ZnCl2 exhibited half of total zinc sequestered by the cells, which corresponds with the upregulation of sequestering proteins such as metallothionein and the downregulation of genes involved with ATP synthesis and phycobilisome assembly. These analyses were combined with growth monitoring, microscopy, quantitative polymerase chain reaction (qPCR) and flow cytometry to present a full spectrum of mechanisms behind zinc response in S. IU 625.

Production and Characterisation of Single and Mixed Activated Carbons from Coconut Shell and Rubber Seed Pericarp Using Microwave-Induced Chemical Activating Agent

Activated carbon from biomass namely coconut shell (CS-AC), rubber seed pericarp(RSP-AC) and their mixed blend (50:50 w/w) coconut shell-rubber seed pericarp activated carbon(CSRSP-AC) were successfully produced by using ZnCl2 as chemical activating agent viamicrowave irradiation heating system. Activation process was performed in commercial microwaveoven at power of 600W for 20 min by using 30%, 40% and 50% of ZnCl2 concentrations. Theactivated carbon was characterized according to BET surface morphology, iodine number andpercentage of MB removal. The results showed that the mixed CSRSP-AC produced the highestsurface area of 584.68 mg2/g with comparison to single CS-AC and RSP-AC at 445.9 mg2/g and462.5 mg2/g respectively. Although CSRSP-AC has the highest surface area and pore volumedevelopment, RSP-AC was found to have the highest iodine number, with the opposite trend beingobserved with MB removal indicating that RSP-AC has the highest adsorptive capacity among thethree activated carbons. The iodine number value and percentages of MB removal increased as theZnCl2 concentration increase from 30% to 50%. These findings revealed that activated carbonproduced from mixed blend of coconut shell and rubber seed pericarp has almost similarcharacteristics to their respective activated carbon derived from single individual biomass.

Feasibility of using a rotating packed bed with blade packings to produce ZnO nanoparticles

A rotating packed bed with blade packings was used to produce zinc oxide (ZnO) nanoparticles by precipitation. Precursors were firstly produced in a continuous liquid-liquid reaction of zinc chloride (ZnCl2) with sodium hydroxide (NaOH). The effects of the concentrations of ZnCl2 and NaOH, the flow rates of aqueous ZnCl2 and NaOH, and the rotational speed on the size of the precursors were studied. Experimental results indicate that increasing concentrations of ZnCl2 and NaOH, decreasing flow rates of aqueous ZnCl2 and NaOH, and decreasing the rotational speed reduced the size of the precursors. The smallest precursors were produced at a ZnCl2 concentration of 0.4mol/L, an NaOH concentration of 0.8mol/L, flow rates of aqueous ZnCl2 and NaOH of 0.3L/min, and a rotational speed of 600rpm. Then, the precursors were calcined at 400°C for 1h to generate ZnO nanoparticles with a mean size of 43nm and a narrow size distribution. The detailed characterizations revealed that the as-produced ZnO nanoparticles were pure ZnO, which comprised a highly crystalline hexagonal wurtzite phase and exhibited a favorable optical property.

Zinc protection in cadmium-induced Blood Brain Barrier permeability: a metabolic and morphological in vitro study

Cadmium (Cd) is a worldwide occupational and environmental pollutant [1]. Cd toxicity is widely known and studied in many tissues and organs such as testis, kidney, liver, lung and brain [2,3]. On the other hand, zinc (Zn) is a trace element known as coenzyme for many proteins such as methallothionein [4]. To date, very little is known about the role of Cd and Zn in BBB permeability. To study their effects in BBB permeability in vitro, the RBE4 cell line was used and different concentrations of CdCl2 and ZnCl2 were tested. Metabolic activity (MTT assay) was performed to test the protective and preventive role of ZnCl2 on CdCl2 toxicity. Western blotting analysis was used to better investigate the molecular pathway involved in Cd-induced BBB permeability evaluating GRP78 (ER stress marker) and caspase-3 protein expression levels. Furthermore, ZO-1 and F-actin immunofluorescent staining was performed to better understand the morphological alterations and BBB permeability achieved by Cd treatment. Our preliminary data highlight the role of Cd in evoking BBB permeability by F-actin and ZO1 dislocations, triggering the caspase-3 molecular pathway activation induced by GRP78-ER stress increase. Moreover, the data clearly show how Zn is able to counteract the metabolic impairment induced by Cd treatment. Taken together these data point out the possible role of Zn in counteracting the Cd-induced BBB impairment.

Immunomodulatory/anti-inflammatory effect of ZOE-based dental materials

ObjectiveThe study assessed the cytotoxicity and immunomodulatory/anti-inflammatory effect of extract from zinc oxide–eugenol (ZOE)-based dental materials during setting using immortalized human dental pulp stem cells (IHDPSCs) and mouse bone marrow monocytes (IMBMMs), and identified the responsible extract component. MethodsIn accord with the ISO 10993-12, we extracted a mixture of ZOE cement and sealer after a specified time. The extract was analyzed by two types of mass spectrometry (ICP-MS and GC–MS). Cell viability was evaluated with extract and serial concentrations of ZnCl2, ZnSO4, and eugenol liquid by WST assay. The immunomodulatory/anti-inflammatory effect of a ZOE component was determined by RT-PCR to detect the downregulatory effect of inflammatory mRNA expression after lipopolysaccharide (LPS)-induced inflammation. ResultsZn2+ and eugenol (2–20ppm) were detected in the ZOE cement and sealer extracts. During the early stage of setting, significant cytotoxicity was observed in IHDPSCs and IMBMMs (p<0.05). The half maximal effective concentration of Zn2+ was 5–8ppm, whereas that of eugenol could not be detected within 80ppm. After extract treatment, the expression of inflammatory mRNA was significantly lower in inflamed IHDPSCs, but not inflamed IMBMMs, than in the LPS control (p<0.05). However, eugenol, not Zn2+, at 5–20ppm downregulated inflammatory mRNA expression in the inflamed IMBMMs with and without the exchange of LPS-pretreated medium. SignificanceZOE was highly cytotoxic, especially during setting, to both cells due to Zn2+ while the immunomodulatory/anti-inflammatory effect of ZOE was induced by eugenol.

Zno Nanowires Electrodeposited for UV Detector Applications

In the last years, wide band gap semiconductors have received great interest due to their wide application range. Specifically, one-dimensional structures of these semiconductors are candidates for many applications. ZnO is an ideal candidate, as it is an n-type semiconductor with a hexagonal structure, a direct wide band gap of 3.36 eV, high electron mobility, and large excitation energy of 60 meV at room temperature. This semiconductor exhibits an efficient emission in the ultraviolet and visible range, so it is also promising for UV detection applications. ZnO one-dimensional structures (nanowires) are a promising candidate for efficient UV detectors if they fulfill three requirements: high aspect ratio (length/pore diameter) to obtain high on/off current ratios in UV detectors, oriented along the c-axis of the hexagonal structure to reach high electrical properties for the photodetector, and ZnO nanowires should be ordered perpendicular to the substrate to provide excellent light trapping and improve absorption. In this study, ZnO nanowires have been grown at constant electrochemical deposition. Electrodeposition of ZnO was performed using a standard three-electrode cell, where the working electrode was home made anodic aluminum oxide (AAO) templates, the counter electrode was a Pt mesh, and the reference electrode was Ag/AgCl. The electrolyte used in the electrodeposition was peroxide solution (0.005 M ZnCl2 + 0.1 M KCl + 0.04 M H2O2). ZnCl2 concentration were changed from 0.001 M to 0.01 M. The electrodeposition temperature was 70, 75, and 80 °C. The morphology, uniform growth, and filling ratio were controlled by the ZnCl2 concentration, applied potential, and electrodeposition temperature. At 70 °C and using 0.005 M ZnCl2 in the electrolyte, high aspect ratio, uniform growth, and filling ratio ZnO nanowires were obtained by Scanning Electron Microscopy. The crystallographic structure of the nanowires was controlled by applied potential around the reduction potential of ZnO. X-Ray Diffraction confirms that the nanowires are pure ZnO. The main advantages of growing ZnO nanowires by electrodeposition into AAO are the order of the nanostructures, and perfect control nanowires geometry. Moreover, the electrical properties can be measured in ZnO nanowires embedded into AAO, after removing AAO, and single nanowires. The effect of the pore diameter and length of ZnO nanowires on IV curves, and photoresponse is a wide field waiting to be explored.