Electrocoagulation using commercial grade aluminium electrode for the removal of crystal violet from aqueous solution.

The current research work studies the removal of crystal violet (also known as gentian violet), a kind of dye, from simulated wastewater by electrocoagulation using scrap aluminium roofing sheet as electrode in a batch electrochemical cell. Optimization of different operational parameters - pH, current density, time, initial concentration - was carried out experimentally. The equilibrium was attained at 1 hour and at pH 11. After suitable optimization, a removal of above 90% was achieved at an optimum current density of 20 mA/m2. Also, the adsorption behaviour of crystal violet in electrocoagulation was also studied and the isothermal and kinetic models were proposed to be the Dubinin-Radushkevich model and pseudo-first order model. The mechanism involved during the process was suggested as chemisorption. The adsorption thermodynamic studies were a clear indication that the process is spontaneous and endothermic as well as thermodynamically favourable too. Both chemical and physical characterization of the flocs generated during the electrolysis was explained by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) respectively.

Fabrication of hybrid biosorbent nanoscale zero-valent iron-Sargassum swartzii biocomposite for the removal of crystal violet from aqueous solution.

A novel nanoscale zero-valent iron-Sargassum swartzii (nZVI-SS) biocomposite was synthesized and evaluated for its ability to adsorb crystal violet (CV) from aqueous solutions. Involvement of various functional groups of the biosorbent in preferential adsorption of cationic dye was observed using Fourier transform infrared (FTIR) spectroscopy. Morphological changes occurring on the biocomposite materials were characterized using scanning electron microscopy (SEM). Significant increase (∼90%) in the biosorption of cationic dye was observed with gradual increase in pH of the medium from 3 to 12. The effect of biosorbent concentration, initial pH, temperature, agitation rate, adsorption time, and initial dye concentration was studied for the biosorption of CV using nZVI biocomposite. During the optimization study, maximum biosorption capacity was observed at pH of 8. At various initial CV concentrations (20-100 mg/L), attainment of batch sorption equilibrium was observed within 120 min of reaction time. The Langmuir isotherm model expressed high coefficient of determination (R2 = 0.999). The maximum dye uptake of 200 mg/g was reported at pH 8. Kinetics and temperature profiles were evaluated and reported. Desorption study was carried out with 0.1 M HCl. Investigations proved that nZVI-SS is an excellent biosorbent for the sequestration of CV in aqueous media.

Biosorptive removal of malachite green from aqueous solution using chemically modified brown marine alga Sargassum swartzii.

Sargassum swartzii, marine macro brown alga, showed a high malachite green (MG) biosorption capacity in batch mode of operation. The analytical evidence from Fourier transform infrared spectra confirmed the involvement of amine group in the biosorption of MG and electrostatic interaction type of mechanism was proposed to occur between the amine group of dye and the cationic MG dye solution. Scanning electron micrograph shows the morphological features and the attachment of dye onto the biosorbent. pH edge experiment shows that biosorption capacity was maximum at pH 10. The effect of biosorbent concentration, pH, temperature, adsorption time was studied for the biosorption of MG using S. swartzii. Langmuir, Freundlich and Temkin models were used to describe the isotherm data, of which Langmuir model described the isotherm data with high coefficient of determination R2 = 0.999. The maximum dye uptake of 111.1 mg/g was reported at pH 10 based on Langmuir model. Kinetics and temperature profiles were evaluated and reported. Desorption study was carried out with 0.1 M HCl. Efforts were also made to continuously treat MG bearing wastewater using up-flow packed column. Investigations proved that S. swartzii is an excellent biosorbent for the sequestration of MG in aqueous media.

Induction of molecular organization of oligomers by low-energy electrons.

We reveal that a beam of low-energy electrons (18 eV) can directly trigger long-range molecular ordering of an amorphous, semi-flexible oligomer in a few minutes without the prerequisite of pre-orientation. A strong endothermic transition was detected with a micro-thermal analyzer on the areas that had been exposed to the electron irradiation while the areas that were shielded from the irradiation by a protective mask remained amorphous as usual. This result suggests that long-range molecular ordering only develops in the area of the oligomer film under electron irradiation. This is the first-time effort to use electron irradiation to control the long-range ordering of an amorphous organic thin film above the glass transition temperature.

Operation Homefront: Meeting Clerkship Competencies with Home Visits to Families of Children With Special Needs.

OBJECTIVE: We assessed how third-year medical students' written reflections on home visit experiences with families of children with special needs demonstrate evidence of exposure to 9 selected competencies for pediatric clerkships designated by the Council on Medical Student Education in Pediatrics. METHODS: We reviewed written reflections from 152 third-year medical students. For each competency (2 related to communication were combined), we tabulated the number of reflections in which a given competency was demonstrated. Within each competency, themes are described and presented with exemplary quotes to provide a more robust picture of students' exposure and experience. RESULTS: Of 152 reflections, 100% demonstrated at least 1 of the 8 expected competencies. Each reflection exhibited an average of 3 (3.1) competencies (range: 1-7). The competencies most frequently mentioned were demonstration of respect for patient, parent, and family attitudes, behaviors, and lifestyles (90%) and demonstration of positive attitude toward education (76%). Less frequently mentioned competencies included demonstration of behaviors and attitudes that promote patients' and families' best interests (41%), demonstration of effective verbal and nonverbal communication skills (a combination of 2 communication-related competencies) (33%), and description of barriers that prevent children from accessing health care (37%). The following competencies were least often mentioned: description of a pediatrician's role and responsibility in advocating for patients' needs (10%), description of the important role of patient education (8%), or description of the types of problems that benefit from a community approach (17%). CONCLUSIONS: Our analysis demonstrates that community-based home visits can provide medical students with opportunities to meet required pediatric clerkship competencies.

Increased p85/55/50 expression and decreased phosphotidylinositol 3-kinase activity in insulin-resistant human skeletal muscle.

Insulin resistance is predominantly characterized by decreased insulin-stimulated glucose uptake into skeletal muscle. In the current study, we have assessed various aspects of the phosphatidylinositol (PI) 3-kinase pathway in skeletal muscle biopsies obtained from normal, obese nondiabetic, and type 2 diabetic subjects, before and after a 5-h insulin infusion. We found a highly significant inverse correlation between in vivo insulin sensitivity (as measured by the glucose infusion rate) and increased protein expression of p85/55/50, protein kinase C (PKC)-theta activity, levels of pSer307 insulin receptor substrate (IRS)-1 and p-Jun NH2-terminal kinase (JNK)-1, and myosin heavy chain IIx fibers. Increased basal phosphorylation of Ser307 IRS-1 in the obese and type 2 diabetic subjects corresponds with decrease in insulin-stimulated IRS-1 tyrosine phosphorylation, PI 3-kinase activity, and insulin-induced activation of Akt and, more prominently, PKC-zeta/lambda. In summary, increased expression of the PI 3-kinase adaptor subunits p85/55/50, as well as increased activity of the proinflammatory kinases JNK-1, PKC-theta, and, to a lesser extent, inhibitor of kappaB kinase-beta, are associated with increased basal Ser307 IRS-1 phosphorylation and decreased PI 3-kinase activity and may follow a common pathway to attenuate in vivo insulin sensitivity in insulin-resistant subjects. These findings demonstrate interacting mechanisms that can lead to impaired insulin-stimulated PI 3-kinase activity in skeletal muscle from obese and type 2 diabetic subjects.

Identification of animal species by protein radioimmunoassay of bone fragments and bloodstained stone tools.

In forensics and archaeology, it is important to distinguish human from animal remains and to identify animal species from fragmentary bones and bloodstains. We report blind tests in which a protein radioimmunoassay (pRIA) was used to identify the species of six bone fragments lacking morphological specificity and 43 bloodstained lithic tools, knapped experimentally and soaked in blood of known animal and human origin. The submitters of the bone fragments and the bloodstained tools each listed a number of possible species, from which the testers selected the best match with the pRIA results. All six bone fragments were correctly identified: three humans, a deer, a dog, and a cow. Forty-three tools were stained with blood from a wide variety of species including ungulates, carnivores, a fish, and a bird. On 40 of these 43, at least one species (or blood-free control) was identified correctly. Some of the tools were stained with blood of two different species. A mixture of sheep and musk ox blood was correctly identified; in several other mixtures, only a single species was detected. Two tools with human blood and one with human sweat were correctly reported as human. There was a single false positive (one of three controls reported as weakly bovine) and no false negatives. We conclude that the pRIA technique shows a high degree of accuracy in discriminating human from animal bone fragments and bloodstains and in identifying animal species.

Use of solid-phase double-antibody radioimmunoassay to identify species from small skeletal fragments.

Protein radioimmunoassay (pRIA) offers the potential to identify species in small skeletal fragments submitted as forensic evidence. The technique consists of protein extraction followed by a solid-phase double-antibody radioimmunoassay using controls of antisera (raised in rabbits) and radioactive (iodine-125) antibody of rabbit gamma globulin (produced in donkeys). Species determination results from evaluation of radioactivity uptake. To demonstrate the potential of this technique, six known bone samples (three human and three nonhuman, including one from a deer [Odocoileus virginianus]) were submitted for blind analysis. pRIA correctly distinguished the human from the nonhuman samples. Using 200 mg or less of each sample, species of the deer specimen was identified correctly, given the choices of cow, deer, dog, goat, and pig.

Confined growth of poly(butylene succinate) in its miscible blends with poly(vinylidene fluoride): morphology and growth kinetics.

The morphology and confined crystallization behavior of poly(butylene succinate) (PBS) in miscible poly(vinylidene fluoride) (PVDF)/PBS blends has been studied using differential scanning calorimetry (DSC) and optical and atomic force microscopy (OM and AFM). It was found that PBS crystal lamellae nucleated and grew confined inside the matrix of PVDF spherulites. Crystallized PBS domains grow with an ellipsoidal outline within PVDF spherulites formed at a relatively high PVDF crystallization temperature (T(c,PVDF)), while circular domains, engulfing several PVDF spherulites, are seen when growing in the PVDF spherulites created at lower T(c,PVDF). The growth kinetics of PBS confined in the PVDF matrix was investigated under various conditions. The growth rate of PBS (G(PBS)) increases with decreasing crystallization temperature and increasing PBS content under a given PVDF crystallization temperature (T(c,VDF)). For T(c,PVDF) above 145 °C, G(PBS) decreases with T(c,PVDF) for both 50:50 and 30:70 PVDF/PBS blends. However, for T(c,PVDF) below 145 °C, 50:50 and 30:70 PVDF/PBS blends exhibit the opposite G(PBS) trend; that is, G(PBS) for the 50:50 blend decreases with decreasing T(c,PVDF), while for the 30:70 PVDF/PBS blend G(PBS) increases with decreasing T(c,PVDF). It is shown that this behavior cannot be associated with the effect of crossing the boundary of smaller PVDF spherulites formed at a lower temperature. Rather, the behavior appears to be related to the interleaving growth of PBS lamellae among PVDF lamellae or between bundles of PVDF lamellae (fibrils), as in situ AFM observation shows. It is found that the interconnectedness of the molten pockets within the PVDF spherulites, which depends on the PVDF crystallization temperature, is an important factor determining the growth kinetics of PBS confined within the PVDF scaffold.

Control of the fold surface conformation of the lamellae of an oligomer.

Small-angle X-ray scattering revealed that a semirigid oligomer of bisphenol-A-co-ether-octane with a monodisperse chain length is capable of forming ciliated-folded, once-folded, ciliated-extended and fully extended lamellar structures. Isothermal crystallization studies suggested a sequence of structures with increasing crystallization temperature, from a ciliated-folded to a once-folded form and then to a ciliated-extended form as the degree of supercooling is decreased. The crystal surface thus changed from octane cilia to bisphenol A segments and then back to octane cilia as the lamellar structure changed. The results of time-of-flight secondary ion mass spectrometry analyses strongly supported the fold structural models.

A Field Study of the Lava Lizard (Tropidurus Albemarlensis) in the Galapagos Islands.

The effect of removal of the parietal eye (parietalectomy) was studied in free-living lava lizards at the Charles Darwin Research Station in the Galapagos Islands, and the results were compared with those obtained with parietalectomized temperate zone iguanids. Behavior, activity, body temperature, and Iodine-131 uptake by the thyroid gland were studied from Jan. 23 to Feb. 27, 1964. Parietalectomy had no detectable effect on any of the parameters investigated. Home ranges of adult male and female lizards were measured, and defensive and antagonistic behavior was noted. The home ranbges of males often encompassed those of several females. Most adults arose and retired with the sun, and sharply reduced exposure to sunlight at midday. At night, lizards buried themselves in soil and leaf-litter, and the same bed sites were often regularly used. Individuals injected with Iodine-131 were located at night with a scintillation counter. Active lizards had body temperatures averaging 34 to 35°C (range 22.6 to 39.0°C), which showed a bi-modal distribution. Cloud cover was a significant factor in body temperature fluctuations. Sexual dimorphism, both in color and in size of adults, was marked. Females had red "cheek" patches and were smaller than males.Most males had sperm in their sperm ducts and some females contained large-shelled oviducal eggs. Mating males seized females with their jaws, and sometimes carried them some distance before attempting copulation. Posturing and perhaps the odor of refractory females discouraged males. The lizards were found to be insectivorous, but some plant material was also eaten. One small gecko (Phyllodactylus galapagoensis) was recovered from stomach contents.