The change from hydrophilicity to hydrophobicity of HEC/PAA complex membrane for water-in-oil emulsion separation: Thermal versus chemical treatment.

Recently, the growing environmental concerns and economic demands drive the need to develop effective solutions for the treatment of oily wastewater, especially for oil/water emulsions. In this work, hydroxyethyl cellulose (HEC) and poly(acrylic acid) (PAA) are selected to form a complex membrane on the surface of poly(ethylene terephthalate) (PET) nonwoven via layer-by-layer assembly for separation of water-in-oil emulsions. In order to obtain a hydrophobic surface, two post-treatment methods, thermally and chemically induced cross-linking, are applied to modify the hydrogen-bonded HEC/PAA complex membrane. The properties of the two treated HEC/PAA-PET membranes, including surface morphology, chemical structure, chemical composition, thermal stability, mechanical property, and membrane wettability are systematically studied and compared to each other. When the membranes are applied as oil filters to treat water-in-oil emulsions with different concentrations, both of the modified membranes show excellent separation efficiencies with a more than 99.4% rejection for all tested water-in-oil emulsions.

Complex Aerogels Generated from Nano-Polysaccharides and Its Derivatives for Oil-Water Separation.

The complex aerogel generated from nano-polysaccharides, chitin nanocrystals (ChiNC) and TEMPO-oxidized cellulose nanofibers (TCNF), and its derivative cationic guar gum (CGG) is successfully prepared via a facile freeze-drying method with glutaraldehyde (GA) as cross-linkers. The complexation of ChiNC, TCNF, and CGG is shown to be helpful in creating a porous structure in the three-dimensional aerogel, which creates within the aerogel with large pore volume and excellent compressive properties. The ChiNC/TCNF/CGG aerogel is then modified with methyltrichlorosilane (MTCS) to obtain superhydrophobicity/superoleophilicity and used for oil-water separation. The successful modification is demonstrated through FTIR, XPS, and surface wettability studies. A water contact angle of 155° on the aerogel surface and 150° on the surface of the inside part of aerogel are obtained for the MTCS-modified ChiNC/TCNF/CGG aerogel, resulting in its effective absorption of corn oil and organic solvents (toluene, n-hexane, and trichloromethane) from both beneath and at the surface of water with excellent absorption capacity (i.e., 21.9 g/g for trichloromethane). More importantly, the modified aerogel can be used to continuously separate oil from water with the assistance of a vacuum setup and maintains a high absorption capacity after being used for 10 cycles. The as-prepared superhydrophobic/superoleophilic ChiNC/TCNF/CGG aerogel can be used as a promising absorbent material for the removal of oil from aqueous media.

Manipulating the surface wettability of polysaccharide based complex membrane for oil/water separation.

The treatment of oily wastewater is a global challenge owing to its diverse repercussions on environment and human life. The nanoporous complex membrane consisted of cellulose nanocrystals (CNC), chitin nanocrystals (ChiNC) and chitosan (CH) is fabricated on top of the poly (ethylene terephthalate) (PET) nonwoven fabric via a vacuum-assisted filtration method. The interactions among CNC, ChiNC and CH cause the formation of the membrane which shows underoil superhydrophobic property. The CH is demonstrated to play a key role in contributing to the hydrophobicity of membrane. Without any further treatment, the CNC/ChiNC/CH membrane is capable to separate water from water-in-oil emulsion with a high rejection. The separation performance is affected by the thickness of the prepared membrane which directly relates to the concentrations of the complex solutions. Such polysaccharide-based complex membranes with facile fabrication and low cost are promising for use in the field of oil/water separation.

Histopathological features of coeliac disease in a sample of Sudanese patients.

INTRODUCTION: Coeliac disease can occur at any age but is more common in children. Its diagnosis requires correlation between clinical presentations, serological results, endoscopic findings and histopathological classification using the modified Marsh grading system. This study of coeliac disease with biopsies received in the department of histopathology at Soba University Hospital, and Fedail Hospital aimed to gain insight into the demographic profile, clinical presentations and histopathological classification of patients with coeliac disease. METHODS: This was a descriptive study carried out at Soba University Hospital and Fedail Hospital during the period from January 2010-December 2013. Haematoxylin & Eosin and CD3-stained slides of small intestinal biopsies of coeliac disease patients were reviewed for various histological features (1) intraepithelial lymphocytes (IEL) count per 100 enterocytes, (2) crypt hyperplasia and (3) degree of villous atrophy. Based on the histopathological findings, the cases were categorized according to the modified Marsh classification. Demographic and clinical data were obtained from the patient request forms. The data were analyzed using Statistical Package for Social Sciences Software (SPSS). RESULTS: The study included 60 patients. Their age ranged from 2 to 70 years with a mean of 19.5 years (±15.7 SD). The most common age group was below 10 years old (41.6%). Male and female are equally affected. The most common clinical presentation was chronic diarrhoea (55.0%), followed by iron deficiency anemia (41.7%). The degree of villous atrophy ranged from complete atrophy (45.0%), marked atrophy (38.3%) to mild atrophy (16.6%). Marsh grade IIIC was the most common grade. The younger age-groups had a higher prevalence of iron deficiency anaemia and higher Marsh grade.

The effect of high altitude on endothelial and vascular dysfunction markers in preeclamptic patients.

Placental hypoxia, a major component of the pathophysiology of preeclampsia, is associated with various maternal vascular and endothelial dysfunctions. The higher incidence of preeclampsia at high altitude remains incompletely explained. The aim of the present study was to investigate the effect of high altitude on some endothelial and vascular dysfunction markers in normal and preeclamptic pregnancies. Eighty pregnant women (Paras 2-4) were enrolled in this study, which included four groups (each n = 20): normal pregnancies at low altitude (NL), normal pregnancies at high altitude (NH), preeclamptic pregnancies at low altitude (PL), and preeclamptic pregnancies at high altitude (PH). In normal pregnancies at high altitude serum ET-1, plasma TXA2, and serum TNF-α levels increased significantly with a significant reduction in plasma PGI2 (66.81 ± 7.36, 122.86 ± 13.37, 102.23 ± 13.31, 191.57 ± 19.68, respectively) compared with the NL group (48.92 ± 4.58, 89.03 ± 10.67, 69.86 ± 7.97, 238.01 ± 24.55, respectively). In preeclampsia at low altitude serum ET-1, plasma TXA2, and serum TNF-α levels increased significantly with a significant reduction in plasma PGI2 (88.39 ± 9.54, 162.73 ± 15.92, 142.39 ± 15.37, 149.155 ± 15.66, respectively) compared with both NL and NH groups. High altitude significantly augmented these changes in preeclamptic patients (117.75 ± 12.96, 211.01 ± 22.69, 196.86 ± 17.64, 111.92 ± 10.74) compared with PL, NH and NL groups. In conclusion hypoxia at high altitude aggravated the disturbances in the levels of ET-1, TXA2, PGI2 and TNF-α associated with preeclampsia. This may contribute to the higher risk of preeclampsia at high altitude.

Genetic differentiation and phylogeny relationships of functional ApoVLDL-II gene in red jungle fowl and domestic chicken populations.

A total of 243 individuals from Red Jungle Fowl (Gallus gallus spadiceus), Rugao, Anka, Wenchang and Silikes chicken populations were used for polymorphism analysis in functional apoVLDL-II gene by Restriction fragment length polymorphism and single strand conformation polymorphism markers. The results show that Anka population has highest gene diversity and Shannon information index, while Red jungle fowl shows highest effective number of allele. In addition, the higher coefficient of genetic differentiation (Gst) across all loci in apoVLDL-II was indicating that high variation is proportioned among populations. As expected total gene diversity (Ht) has upper estimate compared with within population genetic diversity (Hs) across all loci. The mean Gst value across all loci was (0.194) indicating about 19.4% of total genetic variation could be explained by breeds differences, while the remaining 80.6% was accounted for differences among individuals. The average apoVLDL-II gene flow across all loci in five chicken populations was 1.189. The estimates of genetic identity and distance confirm that these genes are significantly different between genetically fat and lean population, because fat type breed Anka shows highest distance with the other Silikes and Rugao whish are genetically lean. In addition, Wenchang and Red jungle fowl were found more closely and genetically related than the other breeds with 49.4% bootstrapping percentages, then they were related to Silikes by 100% bootstrapping percentages followed by Rugao and finally all of them are related with exotic fat breed Anka.