The ability of Polyaniline coated on saw dust as synthetic adsorbent was investigated for adsorptive removal of Cd (II) ions from aqueous solutions by batch operation. It was found that polyaniline ...coated on saw dust (PANI/SD) is very easy and simple to prepare and can be used as an effective adsorbent for removal of Cd (II) ions from aqueous solutions. Various physico-chemical parameters such as pH, initial metal ion concentration, and adsorbent dosage level and equilibrium contact time were studied. The adsorption of Cd (II) ions increased with an increase in pH. The optimum solution pH for adsorption of Cd (II) from aqueous solutions was found to be 6. Adsorption was rapid and occurred within 20
min for a cadmium concentration range of 10: 40
mg L
−
1
. The kinetic process of Cd (II) adsorption onto PANI/SD was found to fit the pseudo-second-order rate equation. The equilibrium adsorption data for Cd (II) were better fitted to the Freundlich adsorption isotherm model.
► Polyaniline coated on saw dust (PANI/SD) can be used successfully for the removal of cadmium from wastewater. ► Adsorption occurred within 20
min for cadmium concentration range of 10: 40
mg L
−
1
. ► The sorption capacity is dependent on the initial concentration and pH till pH 6. ► The kinetic process of Cd
2+ adsorption was found to fit the pseudo-second-order rate equation. ► The equilibrium data were better fitted to Freundlich adsorption isotherm model.
Abstract Photocatalytic degradation of several harmful organic compounds has been presented as a potential approach to detoxify water in recent decades. Trypan Blue (TB) is an acidic azo dye used to ...distinguish live cells from dead ones and it's classified as a carcinogenic dye. In this study, silver phosphate (Ag 3 PO 4 ) nanoparticles and novel Ag 3 PO 4 /graphene/SiO 2 nanocomposite have been successfully prepared via simple precipitation method. Afterward, their physical properties, chemical composition, and morphology have been characterized using SEM, EDS, TEM, SAED, BET, XRD, FTIR and UV–VIS spectroscopy. The specific surface area of Ag 3 PO 4 and Ag 3 PO 4 /G/SiO 2 nanocomposite were reported to be 1.53 and 84.97 m 2 /g, respectively. The band gap energy of Ag 3 PO 4 and Ag 3 PO 4 /G/SiO 2 nanocomposite was measured to be 2.4 and 2.307 eV, respectively. Photocatalytic degradation of Trypan blue (TB) was studied at different parameters such as pH, catalyst dosage, initial concentration, and contact time. The results showed that, at initial dye concentration of 20 ppm, pH = 2, and using 0.03 g of Ag 3 PO 4 /G/SiO 2 as a photocatalyst, the degradation percent of TB dye in the aqueous solution was 98.7% within 10 min of light exposure. Several adsorption isotherms such as Langmuir, Freundlich, and Temkin adsorption isotherms have been tested in addition to the photocatalytic degradation kinetics. Both catalysts were found to follow the Langmuir isotherm model and pseudo-second-order kinetic model. Finally, the possible photocatalytic performance mechanism of Ag 3 PO 4 /G/SiO 2 was proposed.
Many governments have approved the use of oxytetracycline as an antibiotic additive to food fish, with oxytetracycline now routinely used in many nations. However, oxytetracycline is known to have ...immunosuppression impacts. We, therefore, evaluated the immunological, antioxidative, and histopathological status of Nile tilapia fed a diet containing silymarin (100 mg/kg fish feed) for 0, 2, 4, 6, and 8 weeks. The protective effects of silymarin against Aeromonas hydrophila (A. hydrophila) infection and oxytetracycline treatment were evaluated. Blood parameters (erythrocyte count, white blood cell count, hemoglobin, and packed cell volume) improved over time in fish fed on dietary silymarin. Serum levels of alanine aminotransferase (ALT) were lower in fish fed on dietary silymarin, whereas serum levels of aspartate transferase (AST)and alkaline phosphatase (ALK) were unchanged. Dietary silymarin affected serum lipid profiles as decreases in serum triglyceride and low-density lipoprotein cholesterol levels and a trend toward lower cholesterol levels, whereas serum high-density lipoprotein cholesterol levels were increased compared to fish fed on the control diet. Dietary silymarin resulted in an increase of serum total protein levels and globulin fractions. Significant and progressive increases in catalase and glutathione peroxidase levels were observed after six weeks of feeding on a dietary silymarin before decreasing to control levels at the end of the experimental period. Fish fed on dietary silymarin, interleukin-1 and fish tumor necrosis factor-alpha were upregulated in hepatic tissues; however, interleukin-10 levels decreased to comparable levels to controls after eight weeks. Fish infected with A. hydrophila displayed septicemia (opaque eye, hemorrhagic ulcers, dentated fins, hepatomegaly, and splenomegaly). Reduced mortality was observed in Nile tilapia infected with A. hydrophila and fed a diet containing silymarin, indicating that silymarin improves fish responses to oxytetracycline with a 37% reduction in mortality.
Abstract
The present study is concerned with the development of a new cylindrical basket filled with ion exchange resin. The performance of the reactor was examined by removing Cu
2+
, Fe
2+
and SO
4
...2−
ions from synthetic wastewater. Variables studied were the initial ion concentration in the solution, contact time, resin height inside the cylindrical basket and cylindrical basket rotational speed. Dimensionless analysis was used to obtain a mass transfer correlation for each of the mentioned ions suitable for scale up and design of the present reactor. The experimental results revealed that both the percentage and the rate of removal of (Cu
2+
, Fe
2+
and SO
4
2−
) ions decrease as the initial ion concentration in the solution increases, while they increase as the contact time, rotational speed and (L/d) ratio increase. Both Langmuir’s and Freundlich’s adsorption isotherms were examined and it was found that Langmuir’s adsorption isotherm gives a better fitting for the obtained data than Freundlich’s. Regeneration ability was tested, which revealed the high resin efficiency upon operating several consequence cycles that could reach 4 cycles with a slight decrease in the removal efficiency.
Abstract Optochemistry, an emerging pharmacologic approach in which light is used to selectively activate or deactivate molecules, has the potential to alleviate symptoms, cure diseases, and improve ...quality of life while preventing uncontrolled drug effects. The development of in-vivo applications for optochemistry to render brain cells photoresponsive without relying on genetic engineering has been progressing slowly. The nucleus accumbens (NAc) is a region for the regulation of slow-wave sleep (SWS) through the integration of motivational stimuli. Adenosine emerges as a promising candidate molecule for activating indirect pathway neurons of the NAc expressing adenosine A 2A receptors (A 2A Rs) to induce SWS. Here, we developed a brain-permeable positive allosteric modulator of A 2A Rs (A 2A R PAM) that can be rapidly photoactivated with visible light (λ > 400 nm) and used it optoallosterically to induce SWS in the NAc of freely behaving male mice by increasing the activity of extracellular adenosine derived from astrocytic and neuronal activity.
Background. Shigella, a major diarrheal disease pathogen worldwide, is the target of vaccine development. The Global Enteric Multicenter Study (GEMS) investigated burden and etiology of ...moderate-to-severe diarrheal disease in children aged <60 months and matched controls without diarrhea during 3 years at 4 sites in Africa and 3 in Asia. Shigella was 1 of the 4 most common pathogens across sites and age strata. GEMS Shigella serotypes are reviewed to guide vaccine development. Methods. Subjects' stool specimens/rectal swabs were transported to site laboratories in transport media and plated onto xylose lysine desoxycholate and MacConkey agar. Suspect Shigella colonies were identified by biochemical tests and agglutination with antisera. Shigella isolates were shipped to the GEMS Reference Laboratory (Baltimore, MD) for confirmation and serotyping of S. flexneri; one-third of isolates were sent to the Centers for Disease Control and Prevention for quality control. Results. Shigella dysenteriae and S. boydii accounted for 5.0% and 5.4% respectively, of 1130 Shigella case isolates; S. flexneri comprised 65.9% and S. sonnei 23.7%. Five serotypes/subserotypes comprised 89.4% of S. flexneri, including S. flexneri 2a, S. flexneri 6, S. flexneri 3a, S. flexneri 2b, and S. flexneri 1b. Conclusions. A broad-spectrum Shigella vaccine must protect against S. sonnei and 15 S. flexneri serotypes/subserotypes. A quadrivalent vaccine with O antigens from S. sonnei, S. flexneri 2a, S. flexneri 3a, and S. flexneri 6 can provide broad direct coverage against these most common serotypes and indirect coverage against all but 1 (rare) remaining subserotype through shared S. flexneri group antigens.
Diarrheal disease is the second leading cause of disease in children less than 5 y of age. Poor water, sanitation, and hygiene conditions are the primary routes of exposure and infection. Sanitation ...and hygiene interventions are estimated to generate a 36% and 48% reduction in diarrheal risk in young children, respectively. Little is known about whether the number of households sharing a sanitation facility affects a child's risk of diarrhea. The objective of this study was to describe sanitation and hygiene access across the Global Enteric Multicenter Study (GEMS) sites in Africa and South Asia and to assess sanitation and hygiene exposures, including shared sanitation access, as risk factors for moderate-to-severe diarrhea (MSD) in children less than 5 y of age.
The GEMS matched case-control study was conducted between December 1, 2007, and March 3, 2011, at seven sites in Basse, The Gambia; Nyanza Province, Kenya; Bamako, Mali; Manhiça, Mozambique; Mirzapur, Bangladesh; Kolkata, India; and Karachi, Pakistan. Data was collected for 8,592 case children aged <5 y old experiencing MSD and for 12,390 asymptomatic age, gender, and neighborhood-matched controls. An MSD case was defined as a child with a diarrheal illness <7 d duration comprising ≥3 loose stools in 24 h and ≥1 of the following: sunken eyes, skin tenting, dysentery, intravenous (IV) rehydration, or hospitalization. Site-specific conditional logistic regression models were used to explore the association between sanitation and hygiene exposures and MSD. Most households at six sites (>93%) had access to a sanitation facility, while 70% of households in rural Kenya had access to a facility. Practicing open defecation was a risk factor for MSD in children <5 y old in Kenya. Sharing sanitation facilities with 1-2 or ≥3 other households was a statistically significant risk factor for MSD in Kenya, Mali, Mozambique, and Pakistan. Among those with a designated handwashing area near the home, soap or ash were more frequently observed at control households and were significantly protective against MSD in Mozambique and India.
This study suggests that sharing a sanitation facility with just one to two other households can increase the risk of MSD in young children, compared to using a private facility. Interventions aimed at increasing access to private household sanitation facilities may reduce the burden of MSD in children. These findings support the current World Health Organization/ United Nations Children's Emergency Fund (UNICEF) system that categorizes shared sanitation as unimproved.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background. Diarrhea is a leading cause of illness and death among children aged <5 years in developing countries. This paper describes the clinical and epidemiological methods used to conduct the ...Global Enteric Multicenter Study (GEMS), a 3-year, prospective, age-stratified, case/control study to estimate the population-based burden, microbiologic etiology, and adverse clinical consequences of acute moderate-to-severe diarrhea (MSD) among a censused population of children aged 0-59 months seeking care at health centers in sub-Saharan Africa and South Asia. Methods. GEMS was conducted at 7 field sites, each serving a population whose demography and healthcare utilization practices for childhood diarrhea were documented. We aimed to enroll 220 MSD cases per year from selected health centers serving each site in each of 3 age strata (0-11, 12-23, and 24-59 months), along with 1-3 matched community controls. Cases and controls supplied clinical, epidemiologic, and anthropometric data at enrollment and again approximately 60 days later, and provided enrollment stool specimens for identification and characterization of potential diarrheal pathogens. Verbal autopsy was performed if a child died. Analytic strategies will calculate the fraction of MSD attributable to each pathogen and the incidence, financial costs, nutritional consequences, and case fatality overall and by pathogen. Conclusions. When completed, GEMS will provide estimates of the incidence, etiology, and outcomes of MSD among infants and young children in sub-Saharan Africa and South Asia. This information can guide development and implementation of public health interventions to diminish morbidity and mortality from diarrheal diseases.
Increased environmental awareness and depletion of resources are driving industry to develop alternative fuels from renewable sources that are environmentally more acceptable. Biodiesel is a non ...petroleum based fuel that consists of alkyl esters from transestrification of the refined/edible types of vegetable oils alcohol and alkaline catalysts can be used. These catalysts require anhydrous conditions and feed stocks with low levels of free fatty acids (FFAs). Inexpensive feed stocks are used in biodiesel production to reduce its cost and to get rid of waste oils in environmentally friendly way. These oils may contain high levels of FFAs so it cannot be directly used with the base catalysts currently employed. Acid esterification reduces the FFAs content to the desirable level. The major factors that affect the conversion efficiency of the process are molar ratio of alcohol/oil, amount of catalyst, reaction temperature, catalyst type and stirring speed according to reaction duration. For this study, we used a model acid produced by mixing pure oleic acid with mixed oil (50% sunflower+50% soybean oil). Methanol was used in the experiments due to its low cost. The best conversion efficiency obtained was 96.6% for a molar ratio of 6:1 at a temperature of 60°C, 2.5% H2SO4 and stirring speed of 300rpm. Finally, different types of waste cooking oil from home and restaurants were used to study the conversion efficiency compared with optimum conditions calculated for model acid oil to be used in biodiesel production with low cost.
Accumulation of plastic debris in water bodies has recently become a global concern, where the hotspots are being affected by a flow of toxic plastics from different sources. This study applied a ...science-based methodology for monitoring and assessment of macro plastic debris in the shoreline and sea surface of a pilot Egyptian Mediterranean site. Optical spectral of Sentinel-2 and Planet scope images were examined using a combination of different spectral bands with several indices and verified by the pixel-value classification method of Sentinel-2 images. Further, microwave remote sensing (Sentinel-2, SAR sensor) was analyzed to add more information to the optical study. Quantitative field measurements of marine debris were applied using UNEP/MAP metadata to support satellite results. This study found that 82% of beach accumulated materials were artificial polymers and that classification image was the most precise technique that reflects the real variety of different features. The overall accuracy of plastics detection and identification using remote sensing techniques reached about 70–80%.
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