Reduction of the Structure Parameter of Forward Osmosis Membranes by Using Sodium Bicarbonate as Pore-Forming Agent.

The forward osmosis (FO) process suffers from unfavorable internal concentration polarization (ICP) of the solute within the support layer of thin-film composite forward osmosis (TFC-FO) membranes. To lower the ICP effect, a support layer with low tortuosity, high porosity, and interconnected pores is necessary. In the present investigation, sodium bicarbonate has been presented as a simple pore-forming agent to decline the ICP within a poly(ethersulfone) substrate. In particular, the porous poly(ethersulfone) support layer was fabricated by embedding sodium bicarbonate into the casting solution to form CO2 gas bubbles in the substrate during phase inversion in an acidic nonsolvent. Experimental results revealed that the separation performance of the TFC-FO membranes significantly improved. The most water-permeable membrane was prepared in the acidic nonsolvent (TFC-SB.3) and it demonstrated a water flux of 26.6 LMH and a reverse salt flux of 3.6 gMH in the FO test. In addition, the TFC-SB.3 membrane showed an 85% increase in water permeability (2.13 LMH/bar) with negligible change in salt rejection (94.3%). Such observations were based on the increase of substrate porosity and the improved connectivity of the finger-like channels through in situ CO2 gas bubbling that alleviate the ICP phenomena. Therefore, the current study presents a simple, scalable method to design a high-performance TFC-FO membrane.

Camellia sinensis supplemented diet enhances the innate non-specific responses, haematological parameters and growth performance in Mugil cephalus against Photobacterium damselae.

This study evaluated the effect of dietary supplementation of Camellia sinensis leaf-extract on non-specific immune responses and disease resistance of Mugil cephalus fingerling against P. damselae. Fish were fed with 0 (unsupplemented), 50, 100 and 200 mg/kg of green tea extract (GTE) supplemented diets. Results indicated that GTE decreased mortality in M. cephalus in a dose-dependent manner after challenge with P. damselae. Haematological parameters containing RBC, Hct, Hb and WBC and growth performance (weight gain) showed remarkable changes in comparison with control group. In addition, the phagocytic (PA) and respiratory burst activity (RBA) significantly increased in M. cephalus, fed 100 and 50, 100 and 200 mg/kg GTE, respectively. Lysozyme statistically increased in GTE supplemented fish. Overall, our results indicated that incorporation of C. sinensis supplemented diet at 100 and 200 mg/kg doses significantly enhanced the immune responses in M. cephalus and that the mortality percentage could be remarkably reduced after challenging the fish against P. damselae.

Study of polyamide thin film characteristics impact on permeability/selectivity performance and fouling behavior of forward osmosis membrane.

In recent years, forward osmosis (FO) has received considerable attention due to its huge potentials in water desalination. The thin film composite (TFC) membrane used in the FO desalination consists of a bottom support layer covered by an active layer on top. Polyamide (PA) is commonly employed as an active layer forming via interfacial polymerization between m-phenylenediamine (MPD) and trimesoyl chloride (TMC) monomers. In this study, the effects that the MPD and TMC concentrations could have on the performance and anti-fouling behavior of the obtained FO membrane have been investigated. Results showed that there is a trade-off relationship between the water flux and salt rejection, which by increasing MPD concentration, the water flux was reducedو while the salt rejection was enhanced. Also, by increasing the TMC concentration, an opposite trend was observed. Using 0.20 wt.% of TMC monomer, the highest water fluxes of 21.6 LMH and 29.3 LMH were achieved in two different membrane configurations. Furthermore, higher TMC concentration caused better anti-fouling property, when PA active layer of the membrane was in a high fouling potential environment.

Polyoxometalate based thin film nanocomposite forward osmosis membrane: Superhydrophilic, anti-fouling, and high water permeable.

Thin-film composite (TFC) membranes with high water flux and low reverse salt flux are the most conventional materials for forward osmosis (FO) process. However, these membranes are not suitable for natural or wastewaters treatment due to the intrinsic physicochemical and surface properties of the rejection layer. The present work shows the fabrication of new thin film nanocomposite (TFN) forward osmosis membranes incorporate superhydrophilic modified silica nanoparticles. Surface of silica nanoparticles were functionalized by quaternary ammonium groups and subsequently were coated using superhydrophilic wheel polyoxometalates (POM). TFN membranes containing different weight ratio of nanoparticles in PA rejection layer were synthesized by interfacial polymerization (IP) of m-phenylenediamine (MPD) and trimesoyl chloride (TMC) as monomers in aqueous and organic solution, respectively. POM coated silica nanoparticles were dispersed in aqueous solution of MPD monomer prior to IP process. The changing in the performance and physicochemical properties of TFN membranes incorporating with superhydrophilic nanoparticles were investigated by different instrumental analysis and were compared with a pristine TFC membrane. Compared to pristine TFC membrane, the TFN membrane with 0.2 wt% nanoparticle incorporation (TFNw0.2) showed superior water flux (18 vs. 31 LMH in FO mode) and negligible increases in reverse salt flux (6.25 vs. 8.45 gMH). In addition, better anti-fouling propensity toward protein (bovine serum albumin, BSA) and organic (sodium alginate, SA) foulant was observed. Therefore, Using newly developed thin film nanocomposite membranes may provide a novel class of high-performance membrane for FO processes.

Chitosan-based thin active layer membrane for forward osmosis desalination.

A novel hydrophilic chitosan-based thin active layer membrane was elaborately fabricated through a facile method and its performance was studied in forward osmosis (FO) desalination process. Chitosan (CS) was interfacially polymerized with trimesoyl chloride (TMC) monomer on the surface of sulfonated polyethersulfone-polyethersulfone (SPES-PES) support layer. Two different procedures were employed to incorporate CS into the membrane thin active layer structure. The solutions containing different CS concentrations (from 0.5 to 2.0wt.%) were firstly loaded on the support layer surface, treated in the presence and absence of NaOH solution. The novel CS based membranes were then prepared via addition of TMC solution with appropriate concentration. Compared to commercial thin film composite (TFC) membrane, the modified membrane with an optimal CS concentration demonstrated remarkably higher hydrophilicity and water permeation. The results indicated that the NaOH treatment and higher CS concentration led to form a dense thin active layer, improving membrane performance in salt rejection.

Mini-implant loosening: 3D analysis using the finite element method.

AIM: Mini-implants are a relatively new device for absolute anchorage control in orthodontics. Their failure due to loosening is a multifactorial problem. Improper positioning of mini-implants with different diameters is evaluated in this study via the finite element method. METHODS: Twelve 3D finite element models of a mandibular posterior segment were designed and included the first molar, a mini-implant, the periodontal ligament, and spongy and cortical bone. They were similar except for the mini-implant position and diameter (1.3, 1.6, and 2.2 mm). A vertical force of 300 N was applied to the occlusal molar surface. The von Mises stress and energy produced by the applied occlusal forces were assessed in the mini-implant and bone. RESULTS: The stress findings were between 15.284 and 359.77 MPa for the mini-implants based on their diameters and locations. The mini-implant energy findings were between 0.00084 and 0.258 mJ. These ranges for bone stress and energy changes were 17.611 and 129.45 MPa and 0.296 and 1.575 mJ, respectively. CONCLUSION: A decrease in the distance between the mini-implant and tooth root has a direct effect on different parameters to explain mini-implant loosening.

Thoracic computerized tomographic (CT) findings in 2009 influenza A (H1N1) virus infection in Isfahan, Iran.

BACKGROUND: Pandemic 2009 H1N1 influenza A virus arrived at Isfahan in August 2009. The virus is still circulating in the world. The abnormal thoracic computerized tomographic (CT) scan findings vary widely among the studies of 2009 H1N1 influenza. We evaluated the thoracic CT findings in patients with 2009 H1N1 virus infection to describe findings compared to previously reported findings, and to suggest patterns that may be suggestive for 2009 influenza A (H1N1) in an appropriate clinical setting. METHODS: Retrospectively, the archive of all patients with a diagnosis of 2009 H1N1 influenza A were reviewed, in Al-Zahra Hospital in Isfahan, central Iran, between September 23(rd) 2009 to February 20(th) 2010. Out of 216 patients with confirmed 2009 influenza A (H1N1) virus, 26 cases with abnormal CT were enrolled in the study. Radiologic findings were characterized by the type and pattern of opacities and zonal distribution. RESULTS: Patchy infiltration (34.6%), lobar consolidation (30.8%), and interstitial infiltration (26.9%) with airbronchogram (38.5%) were the predominant findings in our patients. Bilateral distribution was seen in 80.8% of the patients. Only one patient (3.8%) showed ground-glass opacity, predominant radiographic finding in the previous reports and severe acute respiratory syndrome (SARS). CONCLUSIONS: The most common thoracic CT findings in pandemic H1N1 were patchy infiltration, lobar consolidation, and interstitial infiltration with airbronchogram and bilateral distribution. While these findings can be associated with other infections; they may be suggestive to 2009 influenza A (H1N1) in the appropriate clinical setting. Various radiographic patterns can be seen in thoracic CT scans of the influenza patients. Imaging findings are nonspecific.

Clinical features of novel 2009 influenza A (H1N1) infection in Isfahan, Iran.

BACKGROUND: During August 2009, novel H1N1 influenza virus began causing illness in Isfahan. Since rates of hospitalization and mortality due to the disease have varied widely in different countries, we described the clinical, radiologic, and demographic features of H1N1 hospitalized patients in a hospital in Isfahan. METHODS: This cross-sectional study was conducted in Alzahra Hospital during September 2009 to February 2010. Totally, 216 patients with confirmed, probable, or suspected cases of 2009 influenza A (H1N1) were admitted. RESULTS: Most patients were women (50.5%). Mean age of patients was 26.6 ± 19.5 years. The most common complains on admission were respiratory symptoms (91.6%, n= 198), fever (88.4%, n = 191), myalgia (65.7%, n = 142). In addition, 120 patients (56%) had at least one underlying medical disorder. Thirty-six patients (16.7%) died. Mortality was higher in children under 5 years old (10/36, 10%) and female cases (63.9% of died patients). Predicting variables affecting mortality were intensive care unit (ICU) admission and procalcitonin (PCT) > 0.5. Antiviral treatment was prescribed for 200 (92.5%) of the 216 patients. CONCLUSIONS: Based on the findings of the present study, novel H1N1 influenza is highly prevalent among the youth. Moreover, it causes a relatively high morbidity rate. Therefore, people need to be encouraged to have vaccination against 2009 H1N1. Early diagnosis and treatment is related to less admission and shorter duration of hospitalization.