Metal Salt Concentration Research Articles

Metalotolerance Capacity of Autochthonous Bacteria Isolated From Industrial Waste Effluent

Abstract Microbes play significant roles in remediation of heavy metal polluted industrial effluent using the mechanisms of biosorption and bioaccumulation. In the present study, six heavy metal resistant autochthonous bacteria species namely Bacillus cereus, B. megaterium, B. subtilis, Flavobacterium aquatile, Pseudomonas flourescens and Pseudomonas putida were isolated from effluent samples collected from Paper-mill industry (PMI), Paints and Chemicals Industry (PCI), and Steel-rolling Industry (SRI). The isolates were studied for their heavy metal tolerant capacities at different aqueous salt concentrations. Elemental analysis of the industrial effluent samples collected indicated the presence of heavy metals such as Copper (Cu2+), Manganese (Mn2+), Iron (Fe2+) and Lead (Pb2+) at varying concentrations in μg/ml. Generally, there were variations in the minimum inhibitory concentrations (MIC) of the heavy metal salt to each of the bacteria understudy. The MIC value of each of the bacterial isolates to aqueous solution of Cu2SO4 showed that B. megaterium, B. subtilis, Pseudomonas flourescens and Pseudomonas putida had the same MIC value of 20 ± 1.5 μg/mL while Bacillus cereus and Flavobacterium aquatile had MIC values of 13 ± 1.3 μg/mL and 25 ± 2.1 μg/mL respectively. This variation was also noticeable in aqueous salts of Mn2SO4, Fe2SO4 and Pb2SO4. The bacteria isolates showed sensitivity to heavy metals with increasing zone of inhibition as concentration increased with each isolate showing varying degree of metalotolerance. The effectiveness of the autochthonous bacteria as a means to bio-augment the remediation of heavy metal polluted industrial effluent was further proven and recommended.

Metalotolerance Capacity of Autochthonous Bacteria Isolated From Industrial Waste Effluent

Abstract Microbes play significant roles in remediation of heavy metal polluted industrial effluent using the mechanisms of biosorption and bioaccumulation. In the present study, six heavy metal resistant autochthonous bacteria species namely Bacillus cereus, B. megaterium, B. subtilis, Flavobacterium aquatile, Pseudomonas flourescens and Pseudomonas putida were isolated from effluent samples collected from Paper-mill industry (PMI), Paints and Chemicals Industry (PCI), and Steel-rolling Industry (SRI). The isolates were studied for their heavy metal tolerant capacities at different aqueous salt concentrations. Elemental analysis of the industrial effluent samples collected indicated the presence of heavy metals such as Copper (Cu2+), Manganese (Mn2+), Iron (Fe2+) and Lead (Pb2+) at varying concentrations in μg/ml. Generally, there were variations in the minimum inhibitory concentrations (MIC) of the heavy metal salt to each of the bacteria understudy. The MIC value of each of the bacterial isolates to aqueous solution of Cu2SO4 showed that B. megaterium, B. subtilis, Pseudomonas flourescens and Pseudomonas putida had the same MIC value of 20 ± 1.5 μg/mL while Bacillus cereus and Flavobacterium aquatile had MIC values of 13 ± 1.3 μg/mL and 25 ± 2.1 μg/mL respectively. This variation was also noticeable in aqueous salts of Mn2SO4, Fe2SO4 and Pb2SO4.The bacteria isolates showed sensitivity to heavy metals with increasing zone of inhibition as concentration increased with each isolate showing varying degree of metalotolerance. The effectiveness of the autochthonous bacteria as a means to bio-augment the remediation of heavy metal polluted industrial effluent was further proven and recommended.

Upward capillary leaching

Upward capillary leaching is a method of extracting useful components from solutions by filtering them through a column. This method is based on the natural movement of solutions in the column aeration zone. The vadose zone is a geochemical evaporation barrier.The solution moves upward from the water table to the surface via capillaries in the vadose zone, and the water evaporates during its upward movement, resulting in the concentration and deposition of metal salts. In this study, laboratory experiments using a special set-up show that water-soluble metal compounds can be directionally redistributed in a column. Flotation tailings from the Norilsk industrial region were packed into the laboratory column, and drinking water was employed as the leaching agent. The kinetics of the upward solution flow through the column capillaries were investigated. Elemental redistribution in the column aeration zone was confirmed by geochemical analysis.

Piezoelectric characteristics of electrospun PVDF as a function of phase-separation temperature and metal salt content

In this paper, the crystallinity changes in polyvinylidene fluoride (PVDF) as function of varying phase-separation temperatures (0 to 90 °C) and chloride salts (BaCl2, CaCl2, C°Cl2, NaCl, SnCl2, N2H6Cl2) were investigated. FTIR quantitative analysis showed higher β-crystalline and lower α-crystalline content for 70 °C phase-separated PVDF and 70 °C phase-separated PVDF-CaCl2 (15 wt%) samples. XRD and DSC studies also confirmed the influence of 70 °C phase-separation temperature and CaCl2 salt in improving the β-crystallinity in PVDF compared to the neat PVDF sample. Since higher β-crystalline content is favoured for use in piezoelectric applications, these two sample preparation conditions were optimized for use in piezoelectric studies. Electrospun nanowebs of the selected samples were measured for their piezoelectric output signals under applied pressure of 1 kgf and released periodically at 0.5 Hz. From the peak-to-peak output voltage, 70 °C phase-separated PVDF-CaCl2 sample exhibited significantly higher output voltage (+0.89 V) compared to neat PVDF (+0.48 V) and 70 °C phase-separated PVDF (+0.53 V) samples. These results conclude that the combinative effect of phase-separation temperature and metal salt addition plays a vital role in improving the piezoelectric characteristics of PVDF, which signifies the importance of this study.

Synthesis, microstructure and magnetic properties of Fe2CoAl nanofibers

In this work, Fe2CoAl Heusler alloy nanofibers were first synthesized via an electrospinning method. It was found that the crystal structure, fiber diameter and magnetic properties of the samples varied with the metal salt concentration in the precursor solution. Magnetic measurement reveals that the obtained Fe2CoAl nanofibers exhibit ferromagnetic with a high Curie temperature and large coercivity. The saturation magnetic moment of the Fe2CoAl nanofibers at 5[Formula: see text]K is estimated to be 4.5–5.1[Formula: see text][Formula: see text]. The Fe2CoAl nanofibers synthesized using the low-cost electrospinning method in our work are magnetically superior and economically feasible for technological applications.

Silver nanoparticles from leafy green extract of Belgian endive (Cichorium intybus L. var. sativus): Biosynthesis, characterization, and antibacterial activity

We report for the first time a green, simple, and low-cost synthesis of silver nanoparticles (AgNPs) by mixing AgNO3 solution with the aqueous leaf extract of Belgian endive, a variety of Cichorium intybus L., without any harmful reducing and capping agents. The biosynthesis of AgNPs was observed by the color charge from colorless (metal salt solution) to a yellowish brown (nanoparticle colloidal dispersion), which was confirmed by UV–vis spectroscopy, transmission electron microscopy (TEM), and X-ray diffraction (XRD). UV–vis spectra showed the surface plasmon resonance signature of AgNPs around 420nm, TEM revealed that nanoparticles were quasi-spherical with an average diameter ranging from 19 to 64nm depending on the metal salt concentration, and XRD pattern indicated that the biosynthetic process produced face-centered cubic AgNPs. Surface-enhanced Raman spectroscopy analysis showed that the AgNPs were capped with bioactive molecules from the leaf extract, which are also believed to be responsible for the bio-reduction of silver ions. The antibacterial activity of the biosynthesized AgNPs was studied using both the disk diffusion and minimum inhibitory concentration methods against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, and they were found to be effective at picomolar concentration levels.

Synthesis and Characterization of [Zn‐Al] Layered Double Hydroxides: Effect of the Operating Parameters

In this study, [Zn‐Al] layered double hydroxides (LDHs) were prepared using the coprecipitation method at constant pH. The synthesis parameters (including the aging time, synthesis pH, nature of the alkali, concentration of metallic salts, and the cationic molar ratio R = Zn/Al) were varied in order to elucidate their effect on the properties of the obtained materials. Different characterization techniques, namely X‐ray diffraction, Fourier transform infrared, thermogravimetric analysis‐differential thermogravimetry, transmission electron microscopy, energy‐dispersive X‐ray, inductively coupled plasma, and photoluminescence, were used in this study. It was found that obtaining well‐crystallized LDHs requires (i) an aging time of 24 h and (ii) a synthesis pH value in the range 8–12. Our results also show that the concentration of the cationic metallic salts has no influence on the structural properties of the LDHs. The use of NH4OH as alkali for adjusting the pH value during the synthesis favors the formation of nitrated LDH phases while NaOH gives rise to carbonated ones. Moreover, it was found that irrespective of the molar cationic ratio used (between 1 and 5), [Zn‐Al] LDHs could be obtained. The sample synthesized at R = 2 exhibited the best crystallinity.

Comprehensive comparison between the reaction of N,N'-cyclohexane-1,2-diylidene-bis(4-methoxybenzoylhydrazide) with mercury(II) and copper(II) ions. Synthesis, structure, and kinetics of complex formation

Comprehensive comparison between the reaction of N,N'-cyclohexane-1,2-diylidene-bis(4-methoxybenzoylhydrazide) (CHMBH) with HgCl2 and Cu(NO3)2 · 2.5H2O salts have been investigated, including the synthesis, structure and kinetic of complex formation. The reactions of CHMBH with HgCl2 or Cu(NO3)2 · 2.5H2O at the same synthetic conditions have been shown to produce completely different type of complexes: [Hg(CHMBH)Cl2] · CH3CN (I) and [Cu3(μ3-OH)(CTMB)3(NO3)2(CH3CN)2] · 5CH3CN · H2O (II) (CTMB = cyclohexotriazole-3-(4-methoxybenzamide)). The prepared compounds were characterized using different techniques (NMR, IR, UV-Vis and mass spectroscopies, microelemental analysis, thermogravimetry as well as X-ray powder differection and X-ray single crystal crystallography for I (CIF file CCDC no. 1503398). X-ray crystallography shows that the isolated product of I is a mononuclear complex which contains the [Hg(CHMBH)]2+ core. While, the isolated product of II was a trinuclear Cu(II) cluster [Cu3(μ3-OH)(CTMB)3(NO3)2(CH3CN)2] · 5CH3CN · H2O which contains three differently coordinated copper sites. Kinetic studies on the formation of I have been also investigated and compared with that of II. In case of I, the reaction was so slow and exhibits a first-order dependence on the concentration of metal salt and a first-order dependence on the concentration of CHMBH. While in II, the study shows that the reaction is fast and occurs in three distinct phases.

Influence of Ionic Additives on the Pyrolysis Behavior of Paper

In the course of this study the influence of ionic additives (sodium, potassium, lithium, magnesium, and manganese as cations; acetate, lactate, malate, malonate, succinate, and citrate as anions) on the pattern of volatile pyrolysis products of finished paper is investigated. The pyrolysis of paper causes a cascade of reaction products. As expected, the most abundant pyrolysis product is levoglucosan, however, along with other volatile products, such as hydroxyl and carbonyl compounds, furan and pyran derivatives, phenols, and other anhydrosugars, respectively. These compounds can easily be separated and characterized online using analytical pyrolysis in combination with gas chromatography (GC) and mass spectrometry (MS) detection. Both the composition and total amount of volatile pyrolysis products are significantly altered when the paper samples contain metal salt ions and salts of organic acids, respectively. Principal Component Analysis (PCA) was employed for the multivariate analysis of the obtained pyrolysis products. This allows for a qualitative interpretation on how the various ionic additives affect the formation of specific pyrolysis products. When organic acids are added onto the paper, the pyrolysis pattern mainly depends on the protic properties of the organic acids (mono/di/triprotic) and to a lesser extent on the type within a protic class (monoprotic acetate or lactate vs.diprotic malate or malonate or succinate vs. triprotic citrate). The pyrolysis pattern of the paper samples is more markedly influenced by the type of metal ions rather than by the type of organic acid. These effects significantly depend on both the valence and the concentration of the specific metal salt.

Study of the effect of cadmium, lead, zinc salts on the rat blood cells

Changes were detected in the blood of rats caused by heavy metal compounds. The results show that the salts of heavy metals poisoning demonstrates in damage in the blood cells in the animal body and making weaker their immunity. As a result, various changes occur in animals. In addition, material was collected on immune depressive exposure to heavy metals in the body of rats 25, 50, 75, 100 times more compounds of zinc ions, lead and cadmium. Animal disorders were observed in the nervous system, including tearing, inflammation conjunctive sac and certain groups even with bleeding. Leukogram, whichwas made by the blood of rats, showed that the poisoning caused by the impact of three types of heavy salts, has led to significant changes in the health and behavior of the animals. When increasing by 100 times more poisoning three compound salts in animal organisms have been found strong signs of poisoning,finally, all experimental rats died within 5-6 days. It is important to note, animals poisoned by 75-100 times the maximum permissible concentration of heavy metal salts of the three compound salts have died. Leukogram of experimental rats showed that, in the blood of rats, poisoned by three salts, duringneutrophilia and lymphopenia, leukopenia was found. Neutrophils are characterized by granulated toxicity and gipersigmatich core.

Evaluation of Heavy Metal Tolerance Level (MIC) and Bioremediation Potentials of Pseudomonas aeruginosa Isolated from Makera-Kakuri Industrial Drain in Kaduna, Nigeria

Bacterial strains isolated from the Kakuri drain were characterized and subjected to various concentrations of heavy metal salts and their ability to tolerate the heavy metals (Minimum Inhibitory Concentration-MIC) was determined. This shows their ability to tolerate and survive in environments with high levels of heavy metal salts. Eight(8) heavy metals were considered , and included ; Cobalt Chloride (CoCl2), Cadmium Chloride (CdCl2),Copper Sulphate (CuSo4), Mercury Chloride (HgCl2), Nickel Chloride (NiCl2), Potassium Dichromate (K2Cr207), Lead Chloride (PbCl2) and Zinc Sulphate (ZnS04). Strains were subjected to varied millimolar concentrations (1, 2, 5, 10, 20, 30 and 50 mM). Positive and Negative controls were set up to a certain the tolerance level amongst the strains. 100% growth of all strains was observed at 1 mM concentration, while 100% growth was recorded with CuS04, ZnS04 and HgCl2. Most strains were inhibited or could not tolerate the salts at 10 mM concentration, with the exception of ZnS04, PbCl2, and CdCl2. No growth (100% inhibition) was noticed on plates with 20, 30, 40 or 50 mM concentrations. It therefore shows that the strains isolated from the kakuri drain could withstand presence of heavy metals salts up to a concentration of 10 mM.

Phytosynthesis of Silver and Gold Nanoparticles Using the Hot Water Extract of Mixed Woodchip Powder and Their Antibacterial Efficacy

This study investigates the phytosynthesis, characterization, and antibacterial efficacy of silver and gold nanoparticles (NPs) produced using the hot water extract of mixed woodchip powder. The woodchip extract (WCE) was successfully used as both a reducing and stabilizing agent for the phytosynthesis of both crystalline metal NPs. The effects of different physicochemical factors affecting the formation of the metal NPs including reaction pH, concentration of the precursor metal salts, amount of WCE, and external energy input were evaluated. The characterization of the metal NPs was performed by transmission electron microscopy, selected area electron diffraction (SAED), energy dispersive X-ray (EDX) spectroscopy, and X-ray diffraction (XRD) pattern analysis. In addition, the antibacterial efficacy of the phytosynthesized NPs was measured. The AgNPs showed clear antibacterial activity against four representative bacterial strains. However, the AuNPs did not exhibit bactericidal activity, probably due to their surface modifications and relatively large size. These results suggest that the phytosynthesis of the metal NPs using WCE is highly efficient, and its convenience makes it suitable for use in large-scale production.

Optimization of bioconversion conditions for vitamin D3 to 25-hydroxyvitamin D using Pseudonocardia autotrophica CGMCC5098

The optimal culture conditions for bioconversion of vitamin D3 to calcifediol (25(OH)D3) were investigated by varying carbon and nitrogen sources, metal salt concentrations, initial pH, temperature, solvents, surfactants, and agitation speed. In the process of this microbial hydroxylation, the timing of the addition of vitamin D3, which is dissolved in ethanol, is of critical importance. Besides, the concentration of ethanol in zymotic fluid is the key factor to get high conversion ratio of vitamin D3. In particular, the optimal culture conditions were 1.5% glucose, 1.5% soybean cake meal, 0.5% yeast extract, 0.5% corn steep liquor, 0.3% CaCO3, 0.1% NaCl, 0.2% KH2PO4, pH 7.2 at 27 °C and the timing of the addition of vitamin D3 dissolved in 5% (v/v) ethanol was 48 h followed by the inoculation of seed culture broth. Under the optimized conditions, the conversion of vitamin D3 (1 g/L) by Pseudonocardia autotrophica CGMCC5098 in 50 L fermenter resulted in about 61.31% bioconversion ratio (639 mg/L) of 25(OH)D3 on the 5th day.

Inorganic-Organic Ionic Liquid Electrolytes Enabling High Energy-Density Metal Electrodes for Energy Storage

It has recently been shown, in the case of the bis(fluorosulfonyl)amide (FSI) based ionic liquids, that as the concentration of the alkali metal salt (LiFSI or NaFSI) is increased, the alkali metal cation transference number increases, despite an increase in viscosity and decrease in conductivity. At the same time significant enhancements in electrochemical stability and rate performance of devices are also observed. Here we overview some of the recent findings already in the literature and in addition demonstrate the feasibility of stable, high rate room temperature lithium battery cycling in an electrolyte comprised of 60 mol% LiFSI in a trimethyl, isobutyl phosphonium FSI ionic liquid using a high voltage NMC cathode. We also demonstrate that the high rate cycling of lithium and sodium metal in these phosphonium FSI electrolytes leads to a nanostructured anode deposit and a lowering of the interfacial impedance, suggesting a stable SEI layer formation. Finally, we propose a hypothesis that may explain some of the observations thus made, by which the high alkali ion concentration in these mixed electrolyte systems leads to the effective elimination of the mass transport limitations that are chiefly responsible for the formation of dendrites in traditional electrolytes. This work suggests that a new type of ionic liquid consisting of a mixture of metal cations with organic cations can provide a solution to the instability of the reactive alkali metal anodes and hence enable higher energy density technologies.

Pt-Ni Nanoparticle-Supported Multiwalled Carbon Nanotube Prepared By One-Pot Pyrolysis Method in Room-Temperature Ionic Liquids

Platinum nanoparticle-supported on carbon black (Pt/C) are commonly used as a standard electrode catalyst for low-temperature fuel cells due to their good catalytic activity to the oxygen reduction reaction (ORR). But still the electrode catalyst has several issues. For example, a large over potential exceeding ca. 300 mV is required to enhance the ORR rate, carbon corrosion of the catalyst proceeds during the operation, and Pt is one of expensive metals. Recent years Pt-based binary or ternary electrocatalysts with other metals such as Ru, Mo, and Cu are attracting attention because those can increase the catalytic activity and reduce the costs. Of these, there is increasing interest in the Pt-Ni alloys for their favorable catalytic behavior and lower cost.1 In addition to this, several research groups reported that room-temperature ionic liquid (RTIL) can increase the catalytic activity and the durability of the catalysts.2,3 In this research, based on our experience on the metal nanoparticle preparation in RTILs, we attempted to establish a novel preparation method for the Pt-Ni nanoparticle by a pyrolytic method of the metal ions in RTIL and an easy approach for supporting the resultant Pt-Ni onto multiwalled carbon nanotube with sp2structure leading to a higher carbon corrosion resistance. N,N,N-trimethyl-N-propylammonium bis(trifluoromethanesulfonyl)amide ([N1113][Tf2N]) was used as a reaction medium. A mixture of platinum acetylacetonate (Pt(acac)2) and Ni[Tf2N]2 was dissolved in the [N1113][Tf2N]. The concentration ratio of Pt(acac)2 to Ni[Tf2N]2 was controlled to be 1 : 1 and 3 : 1. Each IL solution was agitated at 300 °C for 1~24 hrs under N2 atmosphere. The characterization of the resulting Pt-Ni alloy nanoparticle was conducted by TEM. The composition of the nanoparticle was determined with an EDX and with an ICP. As to the fabrication of Pt-Ni nanoparticle-supported multiwalled carbon nanotube, before the pyrolytic reaction treatment, 2.5 mg of multiwalled carbon nanotube (MWCNT) was added to the RTIL solution with metal salts and dispersed by stirring overnight. After that, the solution was agitated at 300 °C for 4 or 6 hrs under N2 atmosphere and cooled down to room temperature. For comparison, Pt nanoparticle-supported multiwalled carbon nanotube was also prepared by a similar approach. The electrocatalytic activity was determined with a potentiostat/galvanostat. The detailed information was given in our previous article.4 Figure 1a and b shows TEM images of the RTIL solution after the heat treatment at 300 °C for 1 hour. Monodispersed nanoparticles in the RTIL were recognized. EDX analysis of the nanoparticle indicated that they have two component, i.e., Pt and Ni. The mean particle size was 1.47 nm. When Pt-Ni nanoparticle-supported MWCNT (PtNi-MWCNT) was prepared by a similar approach under several metal salt concentration conditions, the mean particle size was ca. 2.0 nm and the particle size was of little relevance to the ratio of Pt to Ni. As shown in Fig. 1c and d, most Pt-Ni nanoparticles are on the MWCNT uniformly, suggesting that PtNi-MWCNT can be easily fabricated by the one-pot pyrolytic process. Electrocatalytic activity of the PtNi-MWCNT for electrochemical ORR was investigated by using standard techniques. All the electrodes showed favorable catalytic abilities but the catalyst prepared in the solution with 5 mM Pt(acac)2 and 5 mM Ni[Tf2N]2(Sample 2) showed the best performance. The characteristics of the resulting PtNi-MWCNT are summarized in Table I along with the data on a commercially available catalysts (TEC30V10E). It is interesting to note that ECSA, mass activity, and Pt loading amount were improved by shorter agitation time, i.e., 4 hrs. At this moment, we do not have the idea to explain it, but we guess the nanoparticle produced under such condition has a different alloy phase or a surface composition. The most important thing is that our created PtNi-MWCNT produced by the one-pot pyrolytic process showed a better performance than the commercially available Pt catalyst. This approach will be one of the choices for creating next-generation electrocatalysts. References V. R. Stamenkovic, B. Fowler, B. S. Mun, G. F. Wang, P. N. Ross, C. A. Lucas, and N. M. Markovic, Science, 315, 493 (2007).J. Snyder, T. Fujita, M. W. Chen, and J. Erlebacher, Nat. Mater., 9, 904 (2010).G. R. Zhang, M. Munoz, and B. J. M. Etzold, Angew. Chem. Int. E d ., 55, 2257 (2016).K. Yoshii, T. Tsuda, T. Arimura, A. Imanishi, T. Torimoto, and S. Kuwabata, RSC Adv., 2, 8262 (2012). Figure 1

Simultaneous adsorption of heavy metal ions and anions from aqueous solutions on chitosan—Investigated by spectrophotometry and SEM-EDX analysis

Chitosan (flakes with a degree of deacetylation of 90%) was used as adsorbent for heavy metal ions in solution (copper, iron, nickel). The adsorption capacities were determined in dependence on the adsorption time and the initial metal salt concentration. With increasing adsorption time as well as the initial metal salt concentration the adsorption capacities increased. Highest adsorption capacity was achieved for copper(II)ions with 110mg/L. Iron(II)- and nickel(II)ions adsorbed with an adsorption capacity of 80mg/L.The surface of chitosan flakes were investigated before and after the adsorption process by SEM and SEM-EDX, respectively. The formation of crystal-like structures was observed by SEM analysis for the investigation of copper(II)sulfate and iron(II)sulfate. It has been noticed that iron(II)ions oxidized before the adsorption on chitosan occurs. In comparison, the adsorption of nickel salt resulted in a smooth layer on the chitosan surface. SEM-EDX analysis revealed that sulfate adsorbs on the chitosan surface besides the metal cations used.

The microscopic and ultramicroscopic changes in the skeletal muscles, caused by heavy metal salts.

The article is devoted to study the structural changes in the skeletal muscles caused by heavy metal salts. The study was conducted on 72 mature male rats. The experimental groups were given to drink water with combinations of heavy metal salts for one, two and three months. This type of water is typical for the water basins in the northern districts of the Sumy region. The study of morphological changes in the striated muscles was concluded using light and scanning electron microscopy. The data analysis revealed that a prolonged duration of negative factor could intensify sclerotic and edematous processes. The structure of muscle fibers was destroyed, nuclei were deformed and placed irregularly, and many petechial hemorrhages occurred. Besides, cross-striation was irregular, I and A bands were deformed and destroyed, H band was hardly visualized. The inner mitochondrial membrane and cristae become deformed. The symplastic nuclei were placed irregularly within sarcoplasm. Besides, they were swollen. Against swollen and enlarged symplastic nuclei, pyknotic nuclei were also found. The structures of sarcoplasmic reticulum were mainly dilated with deformed and ruptured areas. Our study approves that high concentrations of heavy metal salts have a destructive influence on the skeletal striated muscles.

Synthesis and gas separation properties of poly(ionic liquid)-ionic liquid composite membranes containing a copper salt

Composite poly(ionic liquid)-ionic liquid membranes containing copper (I) chloride (CuCl) have been successfully fabricated via photopolymerization of an IL monomer, 1-vinyl-3-butylimidazolium bistriflimide ([C4vim][Tf2N]), in the presence of CuCl and a non-polymerizable IL, 1-butyl-3-methylimidazolium chloride ([C4mim][Cl]), forming the chlorocuprate anion ([CuCl2]−) in situ. The influence of the metal salt content on the gas separation performance of the composite membranes was assessed. Results showed that increasing the content of non-polymerizable IL enhanced the permeabilities of CO2, H2, N2 and CO relative to those obtained in the pristine poly([C4vim][Tf2N]); whereas the addition of CuCl induced a general reduction of gas diffusivity. On the whole, an enhancement of both gas permeability and ideal gas pair selectivity were observed for CO2/N2 and H2/N2 separations in the Cu-containing composite membranes with respect to the neat poly([C4vim][Tf2N]).

Kinetics of Synthesis of Gold Nanoparticles by Acinetobacter sp. SW30 Isolated from Environment.

Cell biomass and metal salt concentration have great influence on morphology of biosynthesized nanoparticle. The aim of present study was to evaluate the effect of varying cell density and gold salt concentrations on synthesis of nanoparticles and its morphology, which has not been studied in bacteria till now. When cells of Acinetobacter sp. SW30 were incubated with different cell density and gold chloride concentrations, tremendous variation in color of colloidal solution containing gold nanoparticles (AuNP) was observed indicating variation in their size and shapes. Surprisingly, monodispersed spherical AuNP of size ~19nm were observed at lowest cell density and HAuCl4 salt concentration while increase in cell number resulted in formation of polyhedral AuNP (~39nm). Significance of this study lays in the fact that the shape and dispersity of AuNP can be customized depending up on the requirement. FTIR spectrum revealed shift from 3221 to 3196cm-1 indicating the presence and role of amino acids in Au3+ reduction while possible involvement of amide I and II groups in stabilization of AuNP. The rate constant was calculated for cell suspension of 2.1×109cfu/ml challenged with 1.0mM HAuCl4, incubated at 30°C and pH 7 using the slopes of initial part of the plot log (Aα-At) versus time as 1.99×10-8M. Also, this is the first study to report the kinetics of gold nanoparticle synthesis by Acinetobacter sp. SW30.

Electrospinning of ultra-thin nanofibers achieved through comprehensive statistical study

Electrospinning is a widely used process to produce nanofibers due to the ability to precisely tune fiber morphology and other nanofiber fabric characteristics. A lot of work in the past few decades to study the various factors affecting electrospun fiber morphologies, however there has been no study to date to look at all contributing factors in a statistically systematical way. In particular, limited work has been conducted demonstrating a method to fabricate high quality, ultrathin nanofibers with mean diameter <50 nm, narrow diameter standard deviation, and low percentage of non-fiber areas (defects). We present a method using a series of statistically designed experiments to create high quality ultrathin polyvinylpyrrolidone nanofibers containing FeCo salts. Results from a Plackett–Burman screening experiment show solution surface tension and solution viscosity are the most significant variables to describe fiber morphology and show metal salt concentration, applied voltage, polymer molecular weight, and solution volume are moderately significant. The Plackett–Burman design is used to inform variables and variable ranges for a subsequent 3-factor, 3-level Box–Behnken design. The polynomial model determined from Box–Behnken experiment has close agreement to measured point validation of an optimized solution, which is determined to have 34.8 mN m−1, viscosity of 42 cS, and metal salt concentration of 3.0% and yielded mean diameter of around 30 nm, with low beads content and diameter standard deviation. This optimized solution recipe is an excellent formulation to make as-spun fibers as precursors for many materials, such as ultrafine FeCo nanotubes or nanorods with mean diameter of around 15 nm.