The high activity of metallic magnesium and alloys limits its potential in biomedical applications;in recent years,extensive efforts have been devoted to modulating this reactivity.In this work,we present Mg(OH)_(2) a...The high activity of metallic magnesium and alloys limits its potential in biomedical applications;in recent years,extensive efforts have been devoted to modulating this reactivity.In this work,we present Mg(OH)_(2) and TiO_(2)barrier coatings to reduce the degradation of magnesium alloy(Mg-Ca-Zn)surfaces.These coatings were deposited by the anodization method and the spin-coating technique,respectively.The anodized layer was coated with TiO_(2)generated from the hydrolysis of 3%weight of TTIP(Ti[OCH(CH_(3))_(2)]_(4),Titanium(IV)isopropoxide)in 2-Propanol deposited by the spin-coating method.Studying the degradation in Ringer’s solution by electrochemical impedance spectroscopy and OCP revealed a 98%reduction in pittings in uncoated samples after 14 days of immersion.The p H measurements revealed that the TiO_(2)coating reduced the alkalization of the physiological environment,keeping the pH at 6.0 values.In vitro studies of two types of bacteria(E.coli and S.aureus)exhibited zones of inhibition in the agar and activity bactericidal(kill time test).The mechanisms behind the improved degradation resistance and enhanced antibacterial activity are presented and discussed here.Surface modification with Mg(OH)_(2)/TiO_(2)coatings is a promising strategy to control the biodegradation of magnesium implants for bone regeneration.展开更多
Magnesium is generally known to degrade in aqueous environments by an electrochemical reaction.The corrosion products of magnesium include hydrogen gas,Mg^(2+),and Mg(OH)_(2).Here,we summarize the published literature...Magnesium is generally known to degrade in aqueous environments by an electrochemical reaction.The corrosion products of magnesium include hydrogen gas,Mg^(2+),and Mg(OH)_(2).Here,we summarize the published literature describing the corrosion characteristics of magnesium,and the antitumor properties of magnesium-associated corrosion products,aiming to induce the therapeutic properties of magnesium and magnesium alloys in solid tumors.The therapeutic potential of corrosion products of magnesium is enormous.Hydrogen gas exhibits antioxidant and anti-inflammatory properties,which amount to potential anti-tumor characteristics.Mg(OH)_(2),which creates a localized alkaline microenvironment,represents a second approach for anti-tumor therapy with magnesium metal.Upregulated concentrations of Mg^(2+)ions in the local tumor microenvironment remodelling are considered a third approach for anti-tumor therapy.Therefore,we speculate about the different physical forms of magnesium that could create an anti-tumor microenvironment upon tumor interventional therapy,a technique that precisely places anti-tumor implants like particles and stents.Finally,we present our viewpoints on the potential use of magnesium in diverse solid tumor therapies to inhibit tumor progression.展开更多
Cu doped Mg(OH)_(2) nanoparticles were synthesized with varying concentrations from 0 to 10%by a chemical synthesis technique of coprecipitation.X-rays diffraction (XRD) of the samples confirms that all the samples ac...Cu doped Mg(OH)_(2) nanoparticles were synthesized with varying concentrations from 0 to 10%by a chemical synthesis technique of coprecipitation.X-rays diffraction (XRD) of the samples confirms that all the samples acquire the hexagonal crystal structure.XRD results indicated the solubility limit of dopant in the host material and the secondary phase of CuO was observed beyond 3%Cu doping in Mg(OH)_(2).The reduction in the size of nanoparticles was observed from 166 to 103 nm for Mg(OH)_(2) and 10% Cu doped Mg(OH)_(2)samples,respectively.The shift in absorption spectra exhibited the systematical enhancement in optical bandgap from 5.25 to 6.085 eV.A good correlation was observed between the bandgap energy and crystallite size of the nanocrystals which confirmed the size induced effect in the nanoparticles.The transformation in the sample morphology was observed from irregular spherical particles to sepals like shapes with increasing the Cu concentration in the host material.The energy dispersive X-Ray (EDX) analysis confirmed the purity of mass percentage composition of the elements present in the samples.展开更多
Porous carbon sheets have wide application prospects in many fields,especially in energy storage of supercapacitor due to the features combining both 2D structure and porous architectures.Herein,a self-deposition appr...Porous carbon sheets have wide application prospects in many fields,especially in energy storage of supercapacitor due to the features combining both 2D structure and porous architectures.Herein,a self-deposition approach is proposed to obtain N-doped mesoporous carbon nanosheets (N-MCNs),using 3-aminophenol (3-AF) as precursor and Mg(OH)_(2) sheet as hard template.This process realizes the direct carbon formation using 3-AF monomer as carbon precursor under the catalysis of hard template avoiding the polymerization and utilization of solvent.The mass ratio of 3-AF to Mg(OH)_(2) plays an important role in determining the pore structures and the resulting capacitance behavior.The results show that N-MCNs with a mass ratio of 3-AF and Mg(OH)_(2) of 1:1 have good electrochemical behavior for supercapacitors.This N-MCNs based electrode exhibits a high capacitance of 240 F·g^(-1)at 1 A·g^(-1),good rate performance(75.4%retention ratio at 20 A·g^(-1)),and high cycling stability with 98.3% initial capacitance retained after 10000 cycles.Symmetric supercapacitors on N-MCNs achieve energy density of 18.2 W·h·kg^(-1) and power density of 0.4 kW·kg^(-1) operated within a wide potential range of 0–1.6 V in 1.0 mol·L^(-1) Na_(2)SO_(4) solution,exhibiting its potential for electrode materials with high performance.展开更多
Objective:To determine the effect of hydroxide compounds on the viability of dermatophytic cells.Methods:Two strains(Trichophyton mentagrophytes and Epidermophyton floccosum)of dermatophytes were clinical isolated fro...Objective:To determine the effect of hydroxide compounds on the viability of dermatophytic cells.Methods:Two strains(Trichophyton mentagrophytes and Epidermophyton floccosum)of dermatophytes were clinical isolated from an old male patient with tinea corporis at AL-Hussein General Hospital of Karbala Province.Skin scales of fungal lesion were cultured on Sabouraud dextrose agar containing 0.05 g chloramphenicol.The hydroxide compounds were dissolved in melted fungal media to obtain different percentages(0.625%,1.25%,2.5%,5%).Then the fungal growth on solid media containing tested compounds was determined by using colony diameter method and different concentrations of KOH,NaOH,Mg(OH)_(2)and Ca(OH)_(2)were tested against two species of dermatophytes.Experiments were repeated triplicate for statistical analysis and the data were analyzed for SE of each experiment.Results:KOH and NaOH(down to 1.25%)showed the ability to completely inhibit the growth of both strains of dermatophytes(Trichophyton mentagrophytes and Epidermophyton floccosum).Other two hydroxide compounds revealed variable effects on dermatophytes cells.Conclusions:The strong hydroxide compounds showed a harmful effect on fungal structures and functions.In addition to diagnosis,pathogenic fungi like dermatophytes were killed after treating with these hydroxide agents.展开更多
基金financed by the FOMIX-Yucatán 2008-108160,CONACYT LAB-2009-01-123913,292692,294643,188345,and 204822 projectsthe financial support received from CONACYT。
文摘The high activity of metallic magnesium and alloys limits its potential in biomedical applications;in recent years,extensive efforts have been devoted to modulating this reactivity.In this work,we present Mg(OH)_(2) and TiO_(2)barrier coatings to reduce the degradation of magnesium alloy(Mg-Ca-Zn)surfaces.These coatings were deposited by the anodization method and the spin-coating technique,respectively.The anodized layer was coated with TiO_(2)generated from the hydrolysis of 3%weight of TTIP(Ti[OCH(CH_(3))_(2)]_(4),Titanium(IV)isopropoxide)in 2-Propanol deposited by the spin-coating method.Studying the degradation in Ringer’s solution by electrochemical impedance spectroscopy and OCP revealed a 98%reduction in pittings in uncoated samples after 14 days of immersion.The p H measurements revealed that the TiO_(2)coating reduced the alkalization of the physiological environment,keeping the pH at 6.0 values.In vitro studies of two types of bacteria(E.coli and S.aureus)exhibited zones of inhibition in the agar and activity bactericidal(kill time test).The mechanisms behind the improved degradation resistance and enhanced antibacterial activity are presented and discussed here.Surface modification with Mg(OH)_(2)/TiO_(2)coatings is a promising strategy to control the biodegradation of magnesium implants for bone regeneration.
基金supported by the National Natural Science Foundation of China (Nos. 51774070 and 52004165)the Science and Technology Project of Yunnan Province, China (No. 202101AS070029)
基金supported by the Open Funds for Shaanxi Provincial Key Laboratory of Infection and Immune Diseases(2022-KFZD-1)Natural Science Basic Research Program of Shaanxi(2021JM-080,2022JQ-832)the National Natural Science Foundation of China(82203047)
文摘Magnesium is generally known to degrade in aqueous environments by an electrochemical reaction.The corrosion products of magnesium include hydrogen gas,Mg^(2+),and Mg(OH)_(2).Here,we summarize the published literature describing the corrosion characteristics of magnesium,and the antitumor properties of magnesium-associated corrosion products,aiming to induce the therapeutic properties of magnesium and magnesium alloys in solid tumors.The therapeutic potential of corrosion products of magnesium is enormous.Hydrogen gas exhibits antioxidant and anti-inflammatory properties,which amount to potential anti-tumor characteristics.Mg(OH)_(2),which creates a localized alkaline microenvironment,represents a second approach for anti-tumor therapy with magnesium metal.Upregulated concentrations of Mg^(2+)ions in the local tumor microenvironment remodelling are considered a third approach for anti-tumor therapy.Therefore,we speculate about the different physical forms of magnesium that could create an anti-tumor microenvironment upon tumor interventional therapy,a technique that precisely places anti-tumor implants like particles and stents.Finally,we present our viewpoints on the potential use of magnesium in diverse solid tumor therapies to inhibit tumor progression.
文摘Cu doped Mg(OH)_(2) nanoparticles were synthesized with varying concentrations from 0 to 10%by a chemical synthesis technique of coprecipitation.X-rays diffraction (XRD) of the samples confirms that all the samples acquire the hexagonal crystal structure.XRD results indicated the solubility limit of dopant in the host material and the secondary phase of CuO was observed beyond 3%Cu doping in Mg(OH)_(2).The reduction in the size of nanoparticles was observed from 166 to 103 nm for Mg(OH)_(2) and 10% Cu doped Mg(OH)_(2)samples,respectively.The shift in absorption spectra exhibited the systematical enhancement in optical bandgap from 5.25 to 6.085 eV.A good correlation was observed between the bandgap energy and crystallite size of the nanocrystals which confirmed the size induced effect in the nanoparticles.The transformation in the sample morphology was observed from irregular spherical particles to sepals like shapes with increasing the Cu concentration in the host material.The energy dispersive X-Ray (EDX) analysis confirmed the purity of mass percentage composition of the elements present in the samples.
基金the Natural Science Foundation of Hebei (B02020208088)S&T Program of Hebei (20544401D, 20314401D, 206Z4406G, 21314402D, B2021208074, 21344601D)Tianjin Science and Technology Project (19YFSLQY00070)。
文摘Porous carbon sheets have wide application prospects in many fields,especially in energy storage of supercapacitor due to the features combining both 2D structure and porous architectures.Herein,a self-deposition approach is proposed to obtain N-doped mesoporous carbon nanosheets (N-MCNs),using 3-aminophenol (3-AF) as precursor and Mg(OH)_(2) sheet as hard template.This process realizes the direct carbon formation using 3-AF monomer as carbon precursor under the catalysis of hard template avoiding the polymerization and utilization of solvent.The mass ratio of 3-AF to Mg(OH)_(2) plays an important role in determining the pore structures and the resulting capacitance behavior.The results show that N-MCNs with a mass ratio of 3-AF and Mg(OH)_(2) of 1:1 have good electrochemical behavior for supercapacitors.This N-MCNs based electrode exhibits a high capacitance of 240 F·g^(-1)at 1 A·g^(-1),good rate performance(75.4%retention ratio at 20 A·g^(-1)),and high cycling stability with 98.3% initial capacitance retained after 10000 cycles.Symmetric supercapacitors on N-MCNs achieve energy density of 18.2 W·h·kg^(-1) and power density of 0.4 kW·kg^(-1) operated within a wide potential range of 0–1.6 V in 1.0 mol·L^(-1) Na_(2)SO_(4) solution,exhibiting its potential for electrode materials with high performance.
基金Supported by Pioneer Project Department of Research and Development Directorate of the Ministry of High Education and Scientific Research(Grant No.1026).
文摘Objective:To determine the effect of hydroxide compounds on the viability of dermatophytic cells.Methods:Two strains(Trichophyton mentagrophytes and Epidermophyton floccosum)of dermatophytes were clinical isolated from an old male patient with tinea corporis at AL-Hussein General Hospital of Karbala Province.Skin scales of fungal lesion were cultured on Sabouraud dextrose agar containing 0.05 g chloramphenicol.The hydroxide compounds were dissolved in melted fungal media to obtain different percentages(0.625%,1.25%,2.5%,5%).Then the fungal growth on solid media containing tested compounds was determined by using colony diameter method and different concentrations of KOH,NaOH,Mg(OH)_(2)and Ca(OH)_(2)were tested against two species of dermatophytes.Experiments were repeated triplicate for statistical analysis and the data were analyzed for SE of each experiment.Results:KOH and NaOH(down to 1.25%)showed the ability to completely inhibit the growth of both strains of dermatophytes(Trichophyton mentagrophytes and Epidermophyton floccosum).Other two hydroxide compounds revealed variable effects on dermatophytes cells.Conclusions:The strong hydroxide compounds showed a harmful effect on fungal structures and functions.In addition to diagnosis,pathogenic fungi like dermatophytes were killed after treating with these hydroxide agents.
