Effects of attentional focus and gaze instruction during observational learning of a basketball free-throw.

Observational learning has long been used to instruct individuals on how to perform a novice motor skill. Recently, research has shown a benefit to instructing learners to focus externally when viewing a video model (Asadi, Aiken, Heidari, & Kochackpour, 2021). Research has also highlighted the effectiveness of modeling correct gaze behaviors when learning a cognitive task (Jarodzka, van Gog, Dorr, Scheiter, & Gerjets, 2013). The purpose of the present study was to investigate the effectiveness of combining these two modalities. 40 individuals with a mean age of 21.77 ± 1.40 performed a novel motor task where they were asked to either focus internally or externally, and were provided with traditional instruction or were provided with an experienced performer's gaze behaviors while viewing a video demonstration. It was observed that both the external focus groups and the gaze instructed groups performed a basketball free-throw more accurately and had longer periods of quiet eye than an internal focus or traditional verbal instruction (p's < 0.05). Eye tracking also allowed for the assessment of attentional focus adherence. Participants focused on the instructed cues significantly more than irrelevant task aspects or a different focus types (p's < 0.05). These results highlight the effectiveness of cuing a learner to focus externally during observational learning. It also highlights the usefulness of providing correct gaze behaviors when observing a model.

Simultaneous ultrasound-assisted removal of sunset yellow and erythrosine by ZnS:Ni nanoparticles loaded on activated carbon: optimization by central composite design.

The present study focused on the simultaneous ultrasound-assisted removal of sunset yellow and erythrosine dyes from aqueous solutions using ZnS:Ni nanoparticles loaded on activated carbon (ZnS:Ni-NP-AC) as an adsorbent. ZnS:Ni nanoparticles were synthesized and characterized using different techniques such as FESEM, XRD and TEM. The effects of various parameters such as sonication time, pH, initial dye concentrations and adsorbent dose on the percentage of dye removal were investigated. Parameters were optimized by central composite design (CCD) combined with response surface methodology (RSM) and desirability function (DF). A good agreement between experimental and predicted values was observed. The ultrasound-assisted adsorbent (0.04 g) was capable of high percentage removal (98.7% and 99.6%) of sunset yellow and erythrosine in short time (3.8 min).

Synthesis of nickel sulfide nanoparticles loaded on activated carbon as a novel adsorbent for the competitive removal of Methylene blue and Safranin-O.

Nickel sulfide nanoparticle-loaded activated carbon (NiS-NP-AC) were synthesized as a novel adsorbent for simultaneous and rapid adsorption of Methylene blue (MB) and Safranin-O (SO), as most together compounds in wastewater. NiS-NP-AC was characterized using different techniques such as UV-visible, Fourier transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and Brunauer-Emmett-Teller (BET). The surface area of the adsorbent was found to be very high (1018m(2)/g according BET). By using central composite design (CCD), the effects of variables such as pH, adsorbent dosage, MB concentration, SO concentration and contact time on binary dyes removal were examined and optimized values were found to be 8.1, 0.022g, 17.8mg/L, and 5mg/L and 5.46min, respectively. The very short time required for the dyes removal makes this novel adsorbent as a promising tool for wastewater treatment applications. Different models were applied to analyze experimental isotherm data. Modified-extended Langmuir model showed good fit to equilibrium data with maximum adsorption capacity at 0.022g of adsorbent. An empirical extension of competitive modified-extended Langmuir model was proposed to predict the simultaneous adsorption behavior of MB and SO. Kinetic models were applied to fit the experimental data at various adsorbent dosages and initial dyes concentrations. It was seen that pseudo-second-order equation is suitable to fit the experimental data. Individual removalof each dye was also studied.

Optimization of the ultrasonic assisted removal of methylene blue by gold nanoparticles loaded on activated carbon using experimental design methodology.

The present study was focused on the removal of methylene blue (MB) from aqueous solution by ultrasound-assisted adsorption onto the gold nanoparticles loaded on activated carbon (Au-NP-AC). This nanomaterial was characterized using different techniques such as SEM, XRD, and BET. The effects of variables such as pH, initial dye concentration, adsorbent dosage (g), temperature and sonication time (min) on MB removal were studied and using central composite design (CCD) and the optimum experimental conditions were found with desirability function (DF) combined response surface methodology (RSM). Fitting the experimental equilibrium data to various isotherm models such as Langmuir, Freundlich, Tempkin and Dubinin-Radushkevich models show the suitability and applicability of the Langmuir model. Analysis of experimental adsorption data to various kinetic models such as pseudo-first and second order, Elovich and intraparticle diffusion models show the applicability of the second-order equation model. The small amount of proposed adsorbent (0.01 g) is applicable for successful removal of MB (RE>95%) in short time (1.6 min) with high adsorption capacity (104-185 mg g(-1)).

Experimental design based response surface methodology optimization of ultrasonic assisted adsorption of safaranin O by tin sulfide nanoparticle loaded on activated carbon.

In this research, the adsorption rate of safranine O (SO) onto tin sulfide nanoparticle loaded on activated carbon (SnS-NPAC) was accelerated by the ultrasound. SnS-NP-AC was characterized by different techniques such as SEM, XRD and UV-Vis measurements. The present results confirm that the ultrasound assisted adsorption method has remarkable ability to improve the adsorption efficiency. The influence of parameters such as the sonication time, adsorbent dosage, pH and initial SO concentration was examined and evaluated by central composite design (CCD) combined with response surface methodology (RSM) and desirability function (DF). Conducting adsorption experiments at optimal conditions set as 4 min of sonication time, 0.024 g of adsorbent, pH 7 and 18 mg L(-1) SO make admit to achieve high removal percentage (98%) and high adsorption capacity (50.25 mg g(-)(1)). A good agreement between experimental and predicted data in this study was observed. The experimental equilibrium data fitting to Langmuir, Freundlich, Tempkin and Dubinin-Radushkevich models show that the Langmuir model is a good and suitable model for evaluation and the actual behavior of adsorption. Kinetic evaluation of experimental data showed that the adsorption processes followed well pseudo-second-order and intraparticle diffusion models.

Optimization of the combined ultrasonic assisted/adsorption method for the removal of malachite green by gold nanoparticles loaded on activated carbon: experimental design.

The present study was aimed to experimental design optimization applied to removal of malachite green (MG) from aqueous solution by ultrasound-assisted removal onto the gold nanoparticles loaded on activated carbon (Au-NP-AC). This nanomaterial was characterized using different techniques such as FESEM, TEM, BET, and UV-vis measurements. The effects of variables such as pH, initial dye concentration, adsorbent dosage (g), temperature and sonication time on MG removal were studied using central composite design (CCD) and the optimum experimental conditions were found with desirability function (DF) combined response surface methodology (RSM). Fitting the experimental equilibrium data to various isotherm models such as Langmuir, Freundlich, Tempkin and Dubinin-Radushkevich models show the suitability and applicability of the Langmuir model. Kinetic models such as pseudo -first order, pseudo-second order, Elovich and intraparticle diffusion models applicability was tested for experimental data and the second-order equation and intraparticle diffusion models control the kinetic of the adsorption process. The small amount of proposed adsorbent (0.015 g) is applicable for successful removal of MG (RE>99%) in short time (4.4 min) with high adsorption capacity (140-172 mg g(-1)).

Cadmium telluride nanoparticles loaded on activated carbon as adsorbent for removal of sunset yellow.

Adsorption is a promising technique for decolorization of effluents of textile dyeing industries but its application is limited due to requirement of high amounts of adsorbent required. The objective of this study was to assess the potential of cadmium telluride nanoparticles loaded onto activated carbon (CdTN-AC) for the removal of sunset yellow (SY) dye from aqueous solution. Adsorption studies were conducted in a batch mode varying solution pH, contact time, initial dye concentration, CdTN-AC dose, and temperature. In order to investigate the efficiency of SY adsorption on CdTN-AC, pseudo-first-order, pseudo-second-order, Elovich, and intra-particle diffusion kinetic models were studied. It was observed that the pseudo-second-order kinetic model fits better than other kinetic models with good correlation coefficient. Equilibrium data were fitted to the Langmuir model. Thermodynamic parameters such as enthalpy, entropy, activation energy, and sticking probability were also calculated. It was found that the sorption of SY onto CdTN-AC was spontaneous and endothermic in nature. The proposed adsorbent is applicable for SY removal from waste of real effluents including pea-shooter, orange drink and jelly banana with efficiency more than 97%.

Synthesis and characterization of cadmium selenide nanoparticles loaded on activated carbon and its efficient application for removal of muroxide from aqueous solution.

In the first, Cadmium selenide Nanoparticle loaded on activated carbon (CdSe-NP-AC) has been synthesized and characterized by different techniques including XRD and SEM. Then, this new adsorbent successfully has been applied for the removal of muroxide (MO) from aqueous solution in batch studies, while the effect of various experimental parameters like initial pH (pH(0)), contact time, amount of (CdSe-NP-AC) and initial MO concentration (C(0)) on its removal percentage was examined by one at a time optimization method. It was found following optimization of variable, the adsorption of MO onto (CdSe-NP-AC) followed pseudo-second-order kinetics and show Tempkin and Langmuir models for interpretation of experimental data. It was observed that by increasing the temperature the removal percentage was improved and the positive change in entropy (ΔS°) and heat of adsorption (ΔH°) show the endothermic nature of process, while the high negative value in Gibbs free energy change (ΔG°) indicates the feasible nature of adsorption process.

Determination of cholesterol in food samples using dispersive liquid-liquid microextraction followed by HPLC-UV.

A fast, simple, and sensitive sample preparation procedure based on dispersive liquid-liquid microextraction (DLLME) is proposed for the determination of cholesterol in food samples using isocratic reverse phase high performance liquid chromatography (RP-HPLC) and UV detection. The influence of several important parameters on extraction efficiency of cholesterol was evaluated. Under optimized conditions, a linear relationship was obtained between the peak area and the concentration of cholesterol in the range of 0.03-10 microgl(-1). The detection and quantification limits were 0.01 and 0.03 microgl(-1), respectively. Intra-day and inter-day precisions for the analysis of cholesterol were in the range of 1.0-3.1%. The applicability of the proposed method was demonstrated by analyzing cholesterol in milk, egg yolk and olive oil.

Highly selective and sensitive spectrophotometric determination of trace amounts of silver ion in surfactant media using 2-mercaptobenzoxazole.

A simple and accurate spectrophotometric method for determination of trace amounts of silver ion in tap and wastewater solution and photographic solutions has been described. The spectrophotometric determination of silver ion using 2-mercaptobenzoxazole (MBO) in the presence of Triton X-100 as nonionic surfactant has been carried out. The Beer's law is obeyed over the concentration range of 0.1-9.0 microg mL(-1) of Ag+ ion with the detection limits of 1.6 ng mL(-1). The influence of type and amount of surfactant, pH, complexation time and amount of ligand on sensitivity of method were optimized. Finally the repeatability, accuracy and the effect of interfering ions on the determination of silver ion were evaluated. There is a good agreement between results of proposed method and atomic absorption spectrometry.

A kinetic study of isoamyl acetate synthesis by immobilized lipase-catalyzed acetylation in n-hexane.

The objective of this work was to propose a reaction mechanism and to develop a rate equation for the synthesis of isoamyl acetate by acylation of the corresponding alcohol with acetic anhydride using the lipase Novozym 435 in n-hexane. The reaction between isoamyl alcohol and acetic anhydride occurred at high rate in first place. Then, if excess alcohol was used, produced acetic acid further reacted with remaining alcohol, leading to yields higher than 100% (based on initial acetic anhydride content). This reaction was much slower and took place only when acetic anhydride had been totally consumed. Optimal pH for Novozym 435 was 7.7. Acetic acid strongly inactivated the enzyme but it was partially caused by the pH drop in the biocatalyst aqueous microenvironment. Acetic anhydride also showed an important inhibition effect. On the contrary, isoamyl alcohol and isoamyl acetate had no negative effect on the lipase. The analysis of the initial rate data showed that reaction followed a Ping-Pong Bi-Bi mechanism with inhibition by acetic anhydride. The kinetic constants were obtained by multiple regression analysis of experimental findings. Equation predictions and experimental reaction rate values matched very well at conditions where acetic acid concentration in the medium was low.

Catalytic-kinetic determination of trace amount of formaldehyde by the spectrophotometric method with a bromate-Janus green system.

A new simple and rapid catalytic kinetic method for the determination of trace amount of formaldehyde is described. The method is based on the catalytic effect of formaldehyde on the oxidation of Janus green by bromate in the present of sulfuric acid. The reaction monitored spectrophotometrically by measuring the decrease in absorbance of the reaction mixture at 618 nm. The fixed-time method was used for the first 150 s. For initiation of the reaction, under the optimum conditions, in the concentration range of 0.003-2.5 microg ml(-1) formaldehyde can be determined with a limit of detection 0.0015 microg ml(-1). The relative standard deviation of five replicate measurements is 2.3% for 1.0 microg ml(-1) of formaldehyde. The method was used for the determination of formaldehyde in real samples with satisfactory results.

Bowen's disease of the glans penis (erythroplasia of Queyrat) in plasma cell balanitis.

We report a case of a persistent penile plaque on the glans penis of allegedly more than 20 years' duration, which was refractory to circumcision and local treatment. Over the years, the patient repeatedly presented with a circumscribed inflammatory lesion of the glans penis, diagnosed as Zoon's balanitis on the basis of clinical aspects and two biopsies. Because of unresponsiveness of the lesion to circumcision and focal steroid infiltration, repeated biopsies were performed in an attempt to rule out malignancy. Two further biopsies were carried out. One again showed the features of a plasmacellular inflammation, while the other finally revealed the histopathologic features of erythroplasia of Queyrat (carcinoma in situ or Bowen's disease of the glans penis). We assume that either the former biopsy specimens were taken from a plasma cell-rich reactive infiltrate around the neoplastic lesion, or that carcinoma in situ may have arisen due to the chronic inflammation of Zoon's balanitis plasmacellularis. Radiotherapy was performed with good clinical response and subsequent histopathologic proof of complete remission of the lesion.

Adjuvant immunotherapy in malignant melanoma: impact of antibody formation against interferon-alpha on immunoparameters in vivo.

In an adjuvant clinical trial for high-risk patients with malignant melanoma by using recombinant interleukin-2 (rIL-2) and recombinant interferon-alpha 2b (rIFN-alpha 2b), we monitored the development of antibodies against rIFN-alpha and various immunoparameters as biologic markers for IFN activity in vivo. Thirty-one patients (22 men, nine women) with high-risk malignant melanoma received eight 6-week cycles of rIL-2 and rIFN-alpha. Serum samples of all patients were screened for the presence of antibodies against IFN-alpha by a solid enzyme immunoassay (EIA). Specimens testing positive in the EIA were assessed for their ability to neutralize the antiviral effects of IFN-alpha in vitro in an antibody-neutralizing bioassay (ANB). Furthermore, serum levels of neopterin, beta 2-microglobulin, soluble IL-2 receptor (sIL-2R), anticardiolipin and antithyroglobulin were evaluated. Of 31 patients, 11 (36%) developed binding antibodies; three (27%) of them had antibodies with neutralizing capacities (range, 350-28,000 INU/ml). Of male patients, 8 (36%) of 22 versus 1 (11%) of nine female patients developed antibodies. Statistical analysis (unpaired t test) revealed that all patients with antibody titers showed significant (p < 0.04) lower serum levels of beta 2-microglobulin and reproducible decreases in sIL-2R levels, whereby those with neutralizing antibodies showed significantly (p < 0.0001) lower values than did those with binding antibodies. Elevations of anticardiolipin (17 of 31) and antithyroglobulin (one of 31) were not correlated to the presence of IFN antibodies. Our results show the in vivo significance of antibodies against rIFN-alpha, especially of those with neutralizing capacities. Monitoring of antibody formation as well as immunoparameters like beta 2-microglobulin in clinical trials can contribute to identifying patients who, if necessary, might benefit from alternative IFN treatment, for instance, by using natural IFNs.

No detection of HTLV-I proviral DNA in lesional skin biopsies from Swiss and German patients with cutaneous T-cell lymphoma.

The search for an infective agent linked to cutaneous T-cell lymphoma (CTCL) has also included the human T-cell lymphotropic virus type I (HTLV-I). Using sensitive techniques such as Southern blotting under low stringency conditions of hybridization and polymerase chain reaction (PCR) with primer sets designed to match pol, env and pX sequences of HTLV-I, we have screened lesional skin biopsies of 50 Swiss and German patients suffering from CTCL. No evidence of proviral integration of HTLV-I could be demonstrated in any of our patients. Our results, as well as a review of the literature, indicate that at least for European patients, HTLV-I does not seem to play a role in the aetiology of CTCL.

[Tonsural trichotillomania]. / Tonsur-Trichotillomanie.

Tonsure trichotillomania is a subtype of trichotillomania in which the scalp exhibits a tonsural pattern of alopecia over the crown, extending to the frontal margin and sparing the lateral margins and the nape of the neck. It differs from the more common form of childhood trichotillomania in that predominantly female adolescents are affected and its incidence is related to quite severely pathologic psychodynamics, often with a disturbed relationship to female sexuality. The treating physician should be more guarded in assessing the prognosis; hair plucking often continues for years. Two patients with tonsure alopecia, associated in one case with trichotillomania of the pubic hair and in the other with enuresis, are presented.

[Strategies for gene therapy of melanoma]. / Strategien zur Gentherapie des Melanoms.

Active unspecific immunotherapy in an adjuvant or palliative setting has been shown to enhance survival in melanoma patients, and gene therapy now offers new perspectives for active specific immunotherapy. Gene therapy includes the transfer of genetic material performed by either viral or non-viral methods and in vivo or ex vivo. For melanoma the following approaches are suggested: vaccination with tumour-specific, HLA-associated antigens using peptides or 'naked DNA', vaccination with melanoma cells transfected with cytokine genes or B7, adoptive immunotherapy with specific T-lymphocytes or transfected tumour-infiltrating lymphocytes, or transfection of tumour cells with a tumour suppressor gene whose dysfunction plays a crucial role in melanoma.