Promising Low-Cost Adsorbent from Waste Green Tea Leaves for Phenol Removal in Aqueous Solution.

Phenol is the most common organic pollutant in many industrial wastewaters that may pose a health risk to humans due to its widespread application as industrial ingredients and additives. In this study, waste green tea leaves (WGTLs) were modified through chemical activation/carbonization and used as an adsorbent in the presence of ultrasound (cavitation) to eliminate phenol in the aqueous solution. Different treatments, such as cavitation, adsorption, and sono-adsorption were investigated to remove the phenol. The scanning electron microscope (SEM) morphology of the adsorbent revealed that the structure of WGTLs was porous before phenol was adsorbed. A Fourier Transform Infrared (FTIR) analysis showed an open chain of carboxylic acids after the sono-adsorption process. The results revealed that the sono-adsorption process is more efficient with enhanced removal percentages than individual processes. A maximum phenol removal of 92% was obtained using the sono-adsorption process under an optimal set of operating parameters, such as pH 3.5, 25 mg L-1 phenol concentration, 800 mg L-1 adsorbent dosage, 60 min time interval, 30 ± 2 °C temperature, and 80 W cavitation power. Removal of chemical oxygen demand (COD) and total organic carbon (TOC) reached 85% and 53%. The Freundlich isotherm model with a larger correlation coefficient (R2, 0.972) was better fitted for nonlinear regression than the Langmuir model, and the sono-adsorption process confirmed the pseudo-second-order reaction kinetics. The findings indicated that WGTLs in the presence of a cavitation effect prove to be a promising candidate for reducing phenol from the aqueous environment.

Ligustrum lucidum Leaf Extract-Assisted Green Synthesis of Silver Nanoparticles and Nano-Adsorbents Having Potential in Ultrasound-Assisted Adsorptive Removal of Methylene Blue Dye from Wastewater and Antimicrobial Activity.

Present study was conducted to investigate the adsorption and ultrasound-assisted adsorption potential of silver nanoparticles (AgNPs) and silver nanoparticles loaded on chitosan (AgCS composite) as nano-adsorbents for methylene blue (MB) removal. AgNPs were synthesized using leaf extract of Ligustrum lucidum, which were incorporated on the chitosan's surface for modification. UV−Vis Spectroscopy, FTIR, XRD, SEM, and EDX techniques were used to confirm the synthesis and characterization of nanomaterials. Batch adsorption and sono-adsorption experiments for the removal of MB were executed under optimal conditions; for fitting the experimental equilibrium data, Langmuir and Freundlich's isotherm models were adopted. In addition, the antimicrobial potential of the AgNPs and AgCS were examined against selected bacterial and fungal strains. UV−Vis spectroscopy confirmed AgNPs synthesis from the leaf extract of L. lucidum used as a reducer, which was spherical as exposed in the SEM analysis. The FTIR spectrum illustrated phytochemicals in the leaf extract of L. lucidum functioning as stabilizing agents around AgNPs and AgCS. Whereas, corresponding crystalline peaks of nanomaterial, including a signal peak at 3 keV indicating the presence of silver, were confirmed by XRD and EDX. The Langmuir model was chosen as an efficient model for adsorption and sono-adsorption, which exposed that under optimum conditions (pH = 6, dye initial concentration = 5 mg L−1, adsorbents dosage = 0.005 g, time = 120 min, US power 80 W), MB removal efficiency of AgNPs was >70%, using ultrasound-assisted adsorption compared to the non-sonicated adsorption. Furthermore, AgNPs exhibited promising antibacterial potential against Staphylococcus aureus with the maximum zone of inhibition (14.67 ± 0.47 mm). It was concluded that the green synthesis approach for the large-scale production of metallic nanoparticles is quite effective and can be recommended for efficient and cost-effective way to eradicate dyes, particularly from textile wastewater.

Trends and projections of land use land cover and land surface temperature using an integrated weighted evidence-cellular automata (WE-CA) model.

Land use land cover (LULC) change has become a major concern for biodiversity, ecosystem alteration, and modifying the climatic pattern especially land surface temperature (LST). The present study assessed past and predicted future LULC and LST change in the Swabi District of Pakistan. LULC maps were generated from satellite data for years 1987, 2002, and 2017 using supervised classification. Mean LST and its areal change were estimated for different LULC classes from thermal bands of satellite images. LULC and LST were projected for the year 2047 using the integrated weighted evidence-cellular automata (WE-CA) model and a regression equation developed in this study, respectively. LULC change revealed an increase of > 5% in the built-up while a decrease in the agricultural area by ~ 9%. There was an increase of ~ 63% area in the LST class ≥ 27 °C which may create urban heat island (UHI). Simulation results indicated that the built-up area will further be increased by ~ 3% until 2047. Area associated with LST class > 30 °C indicated a further increase of ~ 38% till 2047 with reference to year 2017. Findings of this study suggested proper utilization of LULC in order to mitigate the creation of UHIs associated with urbanization and built-up areas.

Development of bactericidal spinel ferrite nanoparticles with effective biocompatibility for potential wound healing applications.

The current study was devised to explore the antibacterial activity and underlying mechanism of spinel ferrite nanoparticles (NPs) along with their biocompatibility and wound healing potentials. In this regard, nickel ferrite and zinc/nickel ferrite NPs were synthesized via a modified co-precipitation method and were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy Energy-dispersive X-ray spectroscopy (EDX). The biocompatibility of the synthesized NPs with human dermal fibroblast (HDF) and red blood cells (RBCs) was assessed. The biocompatible concentrations of the NPs were used to investigate the antimicrobial activity against various pathogenic Gram-negative and Gram-positive bacteria. The mode of bactericidal action was also explored. In vitro scratch assay was performed to evaluate the wound healing potential of NPs. The SEM-EDX analysis showed that the average particles size of nickel ferrite and zinc/nickel ferrite were 49 and 46 nm, respectively, with appropriate elemental composition and homogenous distribution. The XRD pattern showed all the characteristic diffraction peaks of spinel ferrite NPs, which confirmed the synthesis of the pure phase cubic spinel structure. The biocompatible concentration of nickel ferrite and zinc/nickel ferrite NPs was found to be 250 and 125 µg ml-1, respectively. Both the NPs showed inhibition against all the selected strains in the concentration range of 50 to 1000 µg ml-1. Studies on the underlying antimicrobial mechanism revealed damage to the cell membrane, protein leakage, and intracellular reactive oxygen species production. The in vitro scratch assay confirmed the migration and proliferation of fibroblast with artificial wound shrinkage. This study shows that nickel ferrite and zinc/nickel ferrite NPs could be a strong candidate for antibacterial and wound healing nano-drugs.

Fabrication of Bacterial Cellulose-Curcumin Nanocomposite as a Novel Dressing for Partial Thickness Skin Burn.

The current study aimed to fabricate curcumin-loaded bacterial cellulose (BC-Cur) nanocomposite as a potential wound dressing for partial thickness burns by utilizing the therapeutic features of curcumin and unique structural, physico-chemical, and biological features of bacterial cellulose (BC). Characterization analyses confirmed the successful impregnation of curcumin into the BC matrix. Biocompatibility studies showed the better attachment and proliferation of fibroblast cells on the BC-Cur nanocomposite. The antibacterial potential of curcumin was tested against Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa), Salmonella typhimurium (S. typhimurium), and Staphylococcus aureus (S. aureus). Wound healing analysis of partial-thickness burns in Balbc mice showed an accelerated wound closure up to 64.25% after 15 days in the BC-Cur nanocomposite treated group. Histological studies showed healthy granulation tissues, fine re-epithelialization, vascularization, and resurfacing of wound bed in the BC-Cur nanocomposite group. These results indicate that combining BC with curcumin significantly improved the healing pattern. Thus, it can be concluded that the fabricated biomaterial could provide a base for the development of promising alternatives for the conventional dressing system in treating burns.

Enhancing the Antibacterial Activity of Erythromycin with Titanium Dioxide Nanoparticles against MRSA.

BACKGROUND: Staphylococcus aureus (S. aureus) is the most common infectious agent in the community and hospitals. Infections with S. aureus are now becoming difficult to be treated by using conventional antibiotics due to its emerging methicillin-resistant S. aureus (MRSA) strain. OBJECTIVE: In the present study, MRSA was isolated from clinical samples and evaluated for resistance against different antibiotics, TiO2 nanoparticles, and their combinations. METHODS: Clinical samples were collected from Ayub Medical Complex (AMC), Abbottabad, Pakistan, and identified by different biochemical tests and polymerase chain reactions (PCR). Kirby-Bauer disk diffusion method was performed to evaluate antimicrobial susceptibility. Minimum Inhibitory Concentration (MIC) of ampicillin, ciprofloxacin, erythromycin, and vancomycin was found out by agar dilution method while the broth dilution method was used for the MIC of TiO2 nanoparticles and their combinations with erythromycin. RESULTS: All 13/100 (13%) MRSA were successfully identified. All isolates were susceptible to quinupristin/ dalfopristin, teicoplanin, and vancomycin, while the highest resistance was seen with erythromycin, penicillin, and tetracycline. MIC showed high resistance against ampicillin (0.25-512 mg/L) and erythromycin (0.25-1024 mg/L). CONCLUSION: The MIC value of 2 mM TiO2 nanoparticles was found to be the most effective concentration after 12 h of incubation, while the combination of erythromycin with 3 mM TiO2 nanoparticles was found to be more potent which significantly lowered down the MIC of erythromycin to 2-16 mg/L.

Evaluation of genotoxicity and hematological effects in common carp (Cyprinus carpio) induced by disinfection by-products.

Disinfection is intended to improve drinking water quality and human health. Although disinfectants may transform organic matter and form disinfection by-products (DBPs), many are branded as cyto- and genotoxic. Traditionally, research focuses on the effects of DBPs on human health, but cytogenic impacts on aquatic organisms still remain ill defined. The current study examines the potential toxic effect of chloroform and iodoform (DBPs) on Cyprinus carpio, selected as a model organism. Fish specimens were exposed to various concentrations of DBPs primarily based on LD50 values, where acute toxicity was monitored for 96 h. Headspace SPME extraction through gas chromatography was employed to assess the effects of spiked DBPs doses in fish blood. Cytotoxicity was monitored using Comet assay. Tail length, tail DNA, and olive tail moment values were quantified to be significant (P < 0.05) as compared to control. A statistically significant (P < 0.05) decrease in all blood parameters (hematology) was observed. Changes in biochemical indices (glucose, total protein, and alanine aminotransferase (ALT)) were also significant. ALT secretion was significantly increased (93 ± 0.05 and 82.8 ± 0.1 U/L) at higher concentration compared to control (56 ± 0.1 U/L), suggesting liver damage. Results demonstrated that iodoform was statistically more damaging as compared to chloroform.

Titanium oxide-bacterial cellulose bioadsorbent for the removal of lead ions from aqueous solution.

In the current study, nanocomposites of bacterial cellulose (BC) and amorphous TiO2 were prepared and characterized. The nanocomposites were evaluated as adsorbent for the removal of lead (Pb) from aqueous solution. The different reactions conditions such as pH, equilibrium time, temperature, adsorbent dose and possible recycling of adsorbent were studied. The nanocomposites were characterized through X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The characterization results confirmed the formation of nanocomposites. Moreover, BC modified with 3 wt% TiO2 showed best results for the removal of Pb ions from aqueous solution. TiO2-BC nanocomposites remove Pb in concentration of 100 mg/L with removal efficiency above 90% in 120 min at pH 7 and room temperature. The adsorbent was recycled, and no profound decrease of efficiency was observed till three cycles of use. Desorption studies were also carried out for the reusability of the adsorbent. The adsorbent was found efficient, stable and reusable for the removal of lead in environmental water samples.

Development of modified montmorillonite-bacterial cellulose nanocomposites as a novel substitute for burn skin and tissue regeneration.

Bacterial cellulose (BC) is a promising biopolymer with wound healing and tissue regenerative properties but lack of antimicrobial property limits its biomedical applications. Therefore, current study was proposed to combine wound healing property of BC with antimicrobial activity of montmorillonite (MMT) and modified montmorillonites (Cu-MMT, Na-MMT and Ca-MMT) to design novel artificial substitute for burns. Designed nanocomposites were characterized through Fe-SEM, FTIR and XRD. The antimicrobial activities of composites were tested against Escherichia coli, Salmonella typhimurium, Citrobacter fruendii, Pseudomonas aeruginosa, Staphylococcus aureus and Methicillin-resistant Staphylococcus aureus. Tissue regeneration and wound healing activities of the composites were assessed in burn mice model. Physico-chemical characterization confirmed the loading of MMT onto surface and BC matrix. Modified MMTs-BC nanocomposites showed clear inhibitory zone against the tested pathogens. Animals treated with modified MMTs-BC nanocomposites exhibited enhanced wound healing activity with tissue regeneration, reepithelialization, healthy granulation and vascularization. These findings demonstrated that modified MMTs-BC nanocomposites could be used as a novel artificial skin substitute for burn patients and scaffold for skin tissue engineering.

Ultrasound-assisted adsorption of phenol from aqueous solution by using spent black tea leaves.

This study is conducted to examine the removal of phenol using spent black tea leaves (SBTL) by the process of ultrasound-assisted adsorption. The effect of different treatment processes, i.e., sonolysis, adsorption, and ultrasound-assisted adsorption, was investigated. The morphology of SBTL was studied using a scanning electron microscope (SEM), and the porous structure of the SBTL was identified before phenol was adsorbed onto the adsorbent. FTIR analysis of SBTL after adsorption showed the presence of an aliphatic band of carboxylic acids which depict degradation of the phenol molecule due to ultrasound-assisted adsorption. The experimental results showed that the hybrid process was found more effective for phenol removal (85%) as determined by a spectrophotometer. The optimum conditions of the reaction parameters were found as: phenol conc. = 25 mg L-1, pH = 3.5, time = 60 min, adsorbent dosage = 800 mg L-1, ultrasound power = 80 W, and operating temperature = 30 ± 2 °C. Chemical oxygen demand (COD) and total organic carbon (TOC) were found to be 78 and 39%, respectively. HPLC studies suggest nonselective oxidation of phenol resulting in by-products such as catechol and hydroquinone and finally carboxylic acids and CO2. In order to find reaction kinetics, different kinetic models, viz. pseudo-first- and pseudo-second-order models, were studied. The best fit to the isotherm models, i.e., Langmuir and Freundlich, was determined. It is concluded that phenol removal by the hybrid process follows the pseudo-second-order reaction kinetics and Langmuir isotherm model. In addition, thermodynamic studies revealed the nonspontaneous and exothermic nature of the phenol adsorption process.

Effect of trihalomethanes (chloroform and bromoform) on human haematological count.

With the increasing concerns about the harmful effects of disinfection products, the process of chlorination is becoming questionable. Bromoform and chloroform are among the most frequently occurring disinfection by-products. Haematological parameters are an important indicator of human well-being which is why the prime objective of the current study was to conduct a dose-response assessment to investigate the effects of trihalomethanes on human haematological count. Blood samples of healthy subjects were exposed to different concentrations (10, 30 and 50 µg/mL) of chloroform and bromoform in vitro to analyse how these compounds affected the haematological count with increasing dose concentrations. Headspace gas chromatography analysis was also conducted on samples to assess the difference between measured and spiked values of doses. The results indicated that the damage caused by bromoform was statistically more significant as compared to chloroform. Haemoglobin (HGB) and mean corpuscular haemoglobin concentration levels lowered as they were significantly affected (p < 0.05) by bromoform at all administered doses. It also significantly damaged platelet level at doses of 30 (p < 0.05) and 50 µg/mL (p < 0.01). Conversely, the damage caused by chloroform was statistically less significant (p > 0.05).

Machine Learning for Social Services: A Study of Prenatal Case Management in Illinois.

OBJECTIVES: To evaluate the positive predictive value of machine learning algorithms for early assessment of adverse birth risk among pregnant women as a means of improving the allocation of social services. METHODS: We used administrative data for 6457 women collected by the Illinois Department of Human Services from July 2014 to May 2015 to develop a machine learning model for adverse birth prediction and improve upon the existing paper-based risk assessment. We compared different models and determined the strongest predictors of adverse birth outcomes using positive predictive value as the metric for selection. RESULTS: Machine learning algorithms performed similarly, outperforming the current paper-based risk assessment by up to 36%; a refined paper-based assessment outperformed the current assessment by up to 22%. We estimate that these improvements will allow 100 to 170 additional high-risk pregnant women screened for program eligibility each year to receive services that would have otherwise been unobtainable. CONCLUSIONS: Our analysis exhibits the potential for machine learning to move government agencies toward a more data-informed approach to evaluating risk and providing social services. Overall, such efforts will improve the efficiency of allocating resource-intensive interventions.

Bacterial cellulose-zinc oxide nanocomposites as a novel dressing system for burn wounds.

Bacterial cellulose possesses physical and mechanical properties of an ideal wound dressing material but lack of antimicrobial activity limits its biomedical applications. Therefore, in current study, the inherent wound healing characteristics of bacterial cellulose and antimicrobial properties of zinc oxide nanoparticles were combined. The reinforcement (impregnation) of zinc oxide nanoparticles into bacterial cellulose sheets was confirmed through various characterization techniques. The antimicrobial capacity of bacterial cellulose-zinc oxide nanocomposites was tested against common burn pathogens. The in-vivo wound healing and tissue regeneration of the nanocomposites was investigated in burn BALBc mice model. Characterization techniques confirmed the successful impregnation of nanoparticles into bacterial cellulose. Bacterial cellulose-zinc oxide nanocomposites exhibited 90%, 87.4%, 94.3% and 90.9% activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Citrobacter freundii, respectively. Bacterial cellulose-zinc oxide nanocomposites treated animals showed significant (66%) healing activity. The histological analysis revealed fine tissue regeneration in composites treated group. These findings suggest that bacterial cellulose-zinc oxide nanocomposites could be a novel dressing material for burns.

Removal of reactive blue 19 dye by sono, photo and sonophotocatalytic oxidation using visible light.

An efficient sonophotocatalytic degradation of reactive blue 19 (RB 19) dye was successfully carried out using sulfur-doped TiO2 (S-TiO2) nanoparticles. The effect of various treatment processes that is sonolysis, photolysis, catalysis, sonocatalysis, photocatalysis, and sonophotocatalysis were investigated for RB 19 removal. S-TiO2 were synthesized in 1, 3 and 5 wt.% of sulfur by sol-gel process and characterized by X-ray diffraction (XRD) and scanning electron microscopy coupled with energy dispersive X-ray (SEM-EDX), UV-Visible diffuse reflectance spectra (DRS). The results confirm anatase phase of TiO2, porous agglomerate structure, and a red shift in the absorbance spectra of S-TiO2. The dye degradation was studied by using UV-Vis spectrophotometer at λ max=594 nm. The reaction parameters such as pH, catalyst dosage, initial dye concentration, ultrasonic power and effect of sulfur doping in different weight percent were studied to find out the optimum degradation conditions. Optimum conditions were found as: S-TiO2=5 wt.%, catalyst (S-TiO2 5 wt.%)=50mg, RB 19 solution concentration=20 mg L(-1), pH=3, ultrasound power=100 and operating temperature=25°C. The response of 5 wt.% S-TiO2 was found better than 1 and 3 wt.% S-TiO2 and other forms TiO2. The sonophotocatalysis process was superior to other methods. During this process the ultrasound cavitation and photocatalysis water splitting takes place which leads to the generation of OH. As reveled by the GCMS results the reactive blue 19 (20 mg L(-1)) was degraded to 90% within 120 min. The S-TiO2 sonophotocatalysis system was studied for the first time for dye degradation and was found practicable, efficient and cost effective for the degradation of complex and resistant dyes such as RB19.

Stimulatory effects of zinc oxide nanoparticles on visual sensitivity and electroretinography b-waves in the bullfrog eye.

During the last decade, a large number of studies have focused on the development of nanomaterials for medical applications. Therefore, the present study was designed to evaluate the stimulatory effects of zinc oxide nanoparticles in the vertebrate visual system. Zinc oxide nanoparticles were synthesized and characterized through photoluminescence, ultraviolet (UV)-visible spectroscopy, field emission scanning electron microscopy and X-ray diffraction measurements. Furthermore, various electrophysiological recordings were obtained from the bullfrog eyecup preparations under various treatment conditions. Photoluminescence data showed a central peak at 386 nm while the UV-visible spectrum showed a sharp absorption band centered around 367 nm. Field emission scanning electron microscopy and X-ray diffraction measurements showed that synthesized zinc oxide nanoparticles have a polycrystalline wurtzite structure, with a round to oval shape and an average particle size of > 40 nm. Electroretinography (ERG) demonstrated that zinc oxide nanoparticles significantly increased the ERG b-wave amplitude in dark-adapted bullfrog eyecups and in the presence of background illumination. Zinc oxide nanoparticles also improved the visual sensitivity by 0.7 log unit of light intensity and shortened the duration of rhodopsin regeneration. Based on the results obtained, it was concluded that zinc oxide nanoparticles may be used to improve visual functions. The present study may add new dimensions to the biomedical applications of nanomaterials in eye research.

Ideology and brand consumption.

Do mundane daily choices, such as what brands people buy in a supermarket, reflect aspects of values and ideologies? This article presents a large-scale field study performed to determine whether traits associated with a conservative ideology, as measured by voting behavior and religiosity, are manifested in consumers' routine, seemingly inconsequential product choices. Our analysis of market shares for a variety of frequently purchased products shows that both of these measures of conservatism are associated with a systematic preference for established national brands (as opposed to their generic substitutes) and with a lower propensity to buy newly launched products. These tendencies correspond with other psychological traits associated with a conservative ideology, such as preference for tradition and the status quo, avoidance of ambiguity and uncertainty, and skepticism about new experiences.

Preparation and application of visible-light-responsive Ni-doped and SnO2-coupled TiO2 nanocomposite photocatalysts.

A new series of visible-light-driven TiO2 photocatalysts constituting lattice-doped Ni and surface-coupled SnO2 nanocomposites, xNi-TiO2-SnO2 (x=0.1, 0.3, 0.5), were synthesized. TiO2 and xNi-TiO2 were prepared by a sol-gel method while the SnO2 was coupled to these via a ligand exchange reaction and finally the catalysts were thermally treated. The presence of Ni ions in the lattice of the photocatalysts was indirectly confirmed by a red shift in DRS spectra. XRD showed crystalline peaks only assignable to TiO2 anatase phase. XPS analysis confirmed that Sn is present on the surface of the catalysts as SnO2 while Ni(2)O(3) is absent. The xNi-TiO2-SnO2 nanocomposites showed a promising visible-light-responsive photocatalytic activity and were found superior to TiO2, xNi-TiO2 and TiO2-SnO2 for the degradation of toluene in air.

Synthesis and control of physical properties of titania nanoparticles as a function of synthetic parameters.

TiO2 nanoparticles were prepared by a two step acid-base catalyzed sol-gel method. The effects of key synthetic parameters, including water/alkoxide ratio, pH, reaction time, and calcination temperature on the physical properties of the final product were investigated. The current study revealed that the desired properties can be inherited in to TiO, by controlling the key parameters to the optimized values. It was found that the grain size decreased with an increase in water/alkoxide ratio and reaction time, increased with calcination temperature while remained unaffected by variation in pH. The longer reaction time not only increases surface area but also anatase phase formation can be accomplished even under high pH. Band-gap was also found to reduce with reaction time >48 h. Change of pH during synthesis to high value resulted into mesoporous TiO2 with anatase as a sole phase. The TiO2 nanoparticles were also doped by first row transition metals in order to investigate their effects on the photophysical properties. The photoluminescence characteristic of the TiO2 was altered differently by different doping metals. Doping with first row transition metals reduces the band-gap of TiO2 in the following order: Cr > Mn > Fe approximately V > Co approximately Ni > Cu approximately Zn.