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Schwertmannite is a poorly-crystalline Fe(III) oxyhydroxysulfate mineral that may control Sb(V) mobility in acid sulfate environments, including acid mine drainage and acid sulfate soils. However, the mechanisms that govern uptake of aqueous Sb(V) by schwertmannite in such environments are poorly understood. To address this issue, we examined Sb(V) sorption to schwertmannite across a range of environmentally-relevant Sb(V) loadings at pH 3 in sulfate-rich solutions. Antimony K-edge extended X-ray absorption fine structure (EXAFS) spectroscopy revealed that Sb(V) sorption (at all loadings) involved edge and double-corner sharing linkages between SbVO6 and FeIIIO6 octahedra. The coordination numbers for these linkages indicate that sorption occurred by Sb(V) incorporation into the schwertmannite structure via heterovalent Sb(V)-for-Fe(III) substitution. As such, Sb(V) sorption to schwertmannite was not limited by the abundance of surface complexation sites and was strongly resistant to desorption when exposed to 0.1 M PO43-. Sorption of Sb(V) also conferred increased stability to schwertmannite, based on changes in the schwertmannite dissolution rate during extraction with an acidic ammonium oxalate solution. This study provides new insights into Sb(V) sorption to schwertmannite in acid sulfate environments, and highlights the role that schwertmannite can play in immobilizing Sb(V) within its crystal structure.

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Rapid industrialization and urbanization have resulted in environmental pollution and unsustainable development of cities. The concentration of 12 potentially toxic metal(loid)s in windowsill dust samples (n = 50) were investigated from different functional areas of Qom city with the highest level of urbanization in Iran. Spatial analyses (ArcGIS 10.3) and multivariate statistics including Principal Component Analysis and Spearman correlation (using STATISTICA-V.12) were adopted to scrutinize the possible sources of pollution. The windowsill dust was very highly enriched with Sb (50 mg/kg) and Pb (1686 mg/kg). Modified degree of contamination (mCd) and the pollution load indices (PLIzone) indicate that windowsill dust in all functional areas was polluted in the order of industrial > commercial > residential > green space. Arsenic, Cd, Mo, Pb, Sb, Cu, and Zn were sourced from a mixture of traffic and industrial activities, while Mn in the dust mainly stemmed from mining activities. Non-carcinogenic health risk (HI) showed chronic exposure of Pb for children in the industrial zone (HI = 1.73). The estimations suggest the possible carcinogenic risk of As, Pb, and Cr in the dust. The findings of this study reveal poor environmental management of the city. Emergency plans should be developed to minimize the health risks of dust to residents.

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This study examines incorporation of Sb(V) into schwertmannite─an Fe(III) oxyhydroxysulfate mineral that can be an important Sb host phase in acidic environments. Schwertmannite was synthesized from solutions containing a range of Sb(V)/Fe(III) ratios, and the resulting solids were investigated using geochemical analysis, powder X-ray diffraction (XRD), dissolution kinetic experiments, and extended X-ray absorption fine structure (EXAFS) spectroscopy. Shell-fitting and wavelet transform analyses of Sb K-edge EXAFS data, together with congruent Sb and Fe release during schwertmannite dissolution, indicate that schwertmannite incorporates Sb(V) via heterovalent substitution for Fe(III). Elemental analysis combined with XRD and Fe K-edge EXAFS spectroscopy shows that schwertmannite can incorporate Sb(V) via this mechanism at up to about 8 mol % substitution when formed from solutions having Sb/Fe ratios ≤0.04 (higher ratios inhibit schwertmannite formation). Incorporation of Sb(V) into schwertmannite involves formation of edge and double-corner sharing linkages between SbVO6 and FeIII(O,OH)6 octahedra which strongly stabilize schwertmannite against dissolution. This implies that Sb(V)-coprecipitated schwertmannite may represent a potential long-term sink for Sb in acidic environments.

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We introduce a novel and generic convolutional unit, DiCE unit, that is built using dimension-wise convolutions and dimension-wise fusion. The dimension-wise convolutions apply light-weight convolutional filtering across each dimension of the input tensor while dimension-wise fusion efficiently combines these dimension-wise representations; allowing the DiCE unit to efficiently encode spatial and channel-wise information contained in the input tensor. The DiCE unit is simple and can be seamlessly integrated with any architecture to improve its efficiency and performance. Compared to depth-wise separable convolutions, the DiCE unit shows significant improvements across different architectures. When DiCE units are stacked to build the DiCENet model, we observe significant improvements over state-of-the-art models across various computer vision tasks including image classification, object detection, and semantic segmentation. On the ImageNet dataset, the DiCENet delivers 2-4 percent higher accuracy than state-of-the-art manually designed models (e.g., MobileNetv2 and ShuffleNetv2). Also, DiCENet generalizes better to tasks (e.g., object detection) that are often used in resource-constrained devices in comparison to state-of-the-art separable convolution-based efficient networks, including neural search-based methods (e.g., MobileNetv3 and MixNet).

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Electrospun polyacrylonitrile/clinoptilolite (PAN/CP) nanofibers were used to extract polycyclic aromatic hydrocarbons (PAHs) (acenaphthene, acenaphthylene, naphthalene, and phenanthrene) from water samples by solid-phase microextraction (SPME). The target PAHs was detected and quantified by gas chromatography equipped with a flame ionization detector. The PAN/CP fibrous coating with uniform morphology and without beads was electrospun after optimizing the electrospinning parameters by the Taguchi method. Thermogravimetric analysis of PAN/CP nanofibers indicated that the nanofibers are thermally stable up to 357°C. The effective parameters that affect the extraction by SPME were optimized using the response surface methodology based on the central composite design. The limits of detection and limits of quantification by the proposed method were 0.10-0.32 and 0.45-1.12 ng mL-1, respectively. The relative standard deviations were below 12%. The method was assessed for extracting PAHs from real samples including agricultural water, rainwater and spring water. The obtained relative recoveries were higher than 86%.

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A polyacrylonitrile (PAN)/polydimethylsiloxane (PDMS) flat membrane was fabricated by electrospinning technique and modified using titanium dioxide (TiO2) nanoparticles and low-energy materials, dimethyldichlorosilane (MeSiCl2)/methyltrichlorosilane (MeSiCl3), to obtain a hydrophobic surface. The new membrane was utilized for the electromembrane extraction (EME) of model molecules including dibutyl phthalate (DBP) and bis [2-ethylhexyl] phthalate (DEHP). The parameters affecting proposed EME were optimized by the response surface methodology (RSM) based on the central composite design (CCD). The optimized values were 200 V of voltage, 20 min of extraction time, 1100 rpm of agitation rate, 10 mL of donor phase volume and 1 mL of acceptor phase volume. From the results, the performance of EME with the new (modified) membrane remained almost constant after ten extraction cycles while the extraction performance of unmodified EME steeply fell after six extraction cycles. The limits of detection (LODs) for DBP and DEHP were 7.40 and 0.08 ng mL-1, respectively. The linear dynamic range (LDR) was in the range of 100-4000 ng mL-1 for DBP and 1-2000 ng mL-1 for DEHP. The relative standard deviations (RSDs) were below 10%, and the relative recoveries were over 86%. The overall energy consumption for the extraction of the model molecules by new EME was 13.4 kWh m-3. The approach is time-efficient and cost-effective, as the fabricated membrane has better reusability than the previous membranes used for EME.

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BACKGROUND: In the recent decade, due to the overwhelming importance of health and prevention of diseases, nurses, the greatest part of the health care system, are acting in any position of the health care delivery system; because nursing have a key role in promotion of health and health care everywhere. The objective of this research was to study the desired positions of nursing in the health care delivery system in Iran. METHODS: This was a triangulation study done on three steps during 2005-2007. At the first step, the positions of nurses were elicited out of library and internet sources. At the second step, the comments of 15 participants were collected using an open questionnaire. Thereafter, at the third step, using the collected data, a questionnaire was made for a poll (all over the country) on the optimal positions of nursing in Iran, and 64 participants answered it. The results were analyzed using descriptive statistics. RESULTS: DERIVED POSITIONS WERE CATEGORIZED IN TWO GROUPS: hospital, and community positions. The results showed that all positions were accepted more than 70%. CONCLUSIONS: Considering positions of nursing and in order to promote the nursing itself and community health, it is suggested that proper planning should be implemented for nurses' activities in these positions by health planners.

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BACKGROUND: Veterans are among the highly-susceptible and highly-esteemed groups of the society. there is no correct, principled, and comprehensive programming with respect to home-nursing care for them. METHODS: In this quasi-experimental study, 26 veterans with spinal cord complications, with a 70-percent damage who were resident of Najaf Abad, Iran were concluded. The data were gathered by a checklist consisted of two parts, the first part included the demographic data and the second part consisted of Para-clinical (clinical findings) assessment of the veterans suffering from urinary infection, laboratorial assessments, and assessing the bedsores. The researcher visited all the veterans and completed the checklist by interviewing them. RESULTS: The mean age of the veterans was 45 (5.1) years and the highest frequency (53.8%) belonged to the age range of 40-44 years. The mean number of the family members was 4.4 people. The veterans who had paraplegia damage included 88.6%. Considering the damage rate, the highest frequency (69.2%) belonged to thoracic vertebra level. all the 26 veterans had been suffering from urinal infection before the managerial intervention; however 20 subjects (76.9%) had urinal infection after the intervention. CONCLUSIONS: It can be stated that pressure wounds are preventable and these caring measures can be offered to susceptible groups of the community in a better and cheaper way if more studies are done with a closer contact and a higher number of samples in addition to have unison among the community-based systems.

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BACKGROUND: Nurses often complain about overwork and underpay. It seems that the association between "quality of working life" (QWL) and the degree of nurses' involvement in their carrier is the critical factor in achieving a higher level of quality of care. This study aimed to assess the quality of working life and its association with "job performance" of the nurses in educational hospitals affiliated to Isfahan University of Medical Sciences in 2007. METHODS: This was a descriptive-correlation study. Target population included all the nurses who were employed in hospitals affiliated to Isfahan University of Medical Sciences. Sample size was 120 of the mentioned nurses. Sampling method was stratified random and data collection tool was a questionnaire. Data analysis was done using mean, frequency distribution and spearman test. RESULTS: Finding of the study showed that the most common kind of quality of working life in the nurses (56.7%) was moderate one. The most frequent nurses' task performance (79.2%) was also related to the moderate performance. There was a direct and significant relationship between job performance and quality of working life in all the aspects. CONCLUSIONS: According to the research findings, it is important to consider the workplace and quality of working life of the nurses for improving productivity and performance of the nurses. Organization and nursing managers should use programs that can improve quality of working life of the nurses.