Study of Ceramic Membrane from Naturally Occurring-Kaolin Clays for Microfiltration Applications

The focus of this work is to assess the quality of porous membranes prepared from naturally occurring kaolin clays and to evaluate the performance of tubular ceramic membranes treating integrated raw effluents from seafood industry. This material has been chosen due to its natural abundance, its non-toxicity, low cost and its valuable properties. The preparation and characterization of porous tubular ceramic membranes, using kaolin powder with and without corn starch as poreforming agent, were reported. SEM photographs indicated that the membrane surface was homogeneous. The effects of material compositions, additives and the relatively lower sintering temperature, ranging from 1100° to 1250°C, on porosity, average pore size, pore-size distribution and mechanical strength of membranes have been investigated. A correlation between microstructure and mechanical properties of membranes has been discussed. The performance of the novel ceramic membranes thus obtained was determined by evaluating both the water permeability and rejection. The obtained membrane was used to treat cuttlefish effluents generated from the conditioning seawater product industry which consumes a great amount of water. Cross-flow microfiltration was performed then, in order to reduce the turbidity and chemical oxygen demand (COD).

Fabrication, Characterization and Permeation Studies of Ionically Cross-linked Chitosan/Kaolin Composite Membranes

This paper presents the successful preparation of porous membranes based on chitosan with enhanced mechanical, thermal and chemical properties applicable in water treatment field. Herein, chitosan/kaolin composite membranes with a cross-linking agent and a porogen were prepared using the solvent casting method. The characterization of the as-fabricated membranes indicated that the combined effect of kaolin as reinforcing agent, polyethylene glycol as pore former and citric acid as cross-linker in a chitosan matrix showed a significant influence on the membrane properties. The results indicated that the incorporation of a hydrophilic porogenic reagent into the collodion in addition to providing a porous morphology makes it possible to obtain a more hydrophilic membrane, and thus induces an increase in the pure water permeability. The cross-linked membranes exhibited an improved water resistance, better thermal and mechanical properties as compared to neat chitosan films. The cross-linked membranes had a mean pore size of 50 nm falling in the range of ultrafiltration. Their functional properties were determined in terms of pure water filtration and molecular weight cut-off tests

Chemical characteristics and cancer risk assessment of smokeless tobacco used in Tunisia (neffa)

Introduction: neffa, a form of air-dried smokeless tobacco used in North Africa, is spuriously perceived as a lower risk alternative to smoking. The objective of this study was to provide information on some harmful constituents of neffa and to use them for cancer risk assessment. Methods: a high-performance liquid chromatography method coupled with fluorescence detector was used to determine polycyclic aromatic hydrocarbons (PAHs) in one sample of neffa. An atomic absorption spectrometry was performed to determine the concentrations of lead and cadmium in three samples of neffa. The levels of toxicants found in neffa were used to assess for lifetime cancer risk as advocated by the US Environment Protection Agency. Results: the determination of PAHs in neffa allowed the identification of phenanthrene and anthracene. However, the higher molecular weight PAHs such as Benzo(a)Pyrene (B(a)P) were not detected. The concentrations of cadmium and lead varied between 1.3 to 2.8μg/g and 1.7 to 4.6μg/g respectively. Cancer risk for cadmium and lead varied between 4.2E-03 to 9.3E-03 and 2.5E-06 to 6.4E-06 respectively. Cancer risk for Cd exceeded the range of 10E-04 to 10E-06 of an acceptable risk. Conclusion: neffa is not a healthy alternative for overcoming smoking addiction. It contains mineral and organic pulmonary toxicants. This study could serve as a scientific basis to inform consumers about the products´ toxicity and help them to quit smokeless tobacco (SLT) use

Brain multiplexes reveal morphological connectional biomarkers fingerprinting late brain dementia states

Accurate diagnosis of mild cognitive impairment (MCI) before conversion to Alzheimer’s disease (AD) is invaluable for patient treatment. Many works showed that MCI and AD affect functional and structural connections between brain regions as well as the shape of cortical regions. However, ‘shape connections’ between brain regions are rarely investigated -e.g., how morphological attributes such as cortical thickness and sulcal depth of a specific brain region change in relation to morphological attributes in other regions. To fill this gap, we unprecedentedly design morphological brain multiplexes for late MCI/AD classification. Specifically, we use structural T1-w MRI to define morphological brain networks, each quantifying similarity in morphology between different cortical regions for a specific cortical attribute. Then, we define a brain multiplex where each intra-layer represents the morphological connectivity network of a specific cortical attribute, and each inter-layer encodes the similarity between two consecutive intra-layers. A significant performance gain is achieved when using the multiplex architecture in comparison to other conventional network analysis architectures. We also leverage this architecture to discover morphological connectional biomarkers fingerprinting the difference between late MCI and AD stages, which included the right entorhinal cortex and right caudal middle frontal gyrus

Bone wax causing a middle trunk plexopathy following vertebral artery injury: a neuroradiological pitfall

Abstract Background Bone wax is a hemostatic agent widely used in surgery. Since it is neither absorbed nor metabolized, its use remains risky and a potential cause of complications. Even though its MRI radiological characteristics are distinguishable, it is generally misinterpreted as postoperative hematoma or trapped air. We report the first case in literature of brachial plexopathy due to the compressive mass effect of bone wax and the main clues that led us to establish this diagnosis prior to its surgical resection. Case presentation A 20-year-old male, victim of stabbing presented with an open wound of the right latero-cervical region with a vascular injury of the V2 segment of the right vertebral artery on CT angiography. He was first admitted for bleeding from the neck uncontrollable with external pressure. The patient underwent an emergency surgical vertebral artery ligation. Forty-eight hours later, he reported a feeling of paresthesia of right arm with right-sided weakness. Neurologic examination revealed a motor deficit of the right triceps and wrist extensor muscles and absence of the triceps reflex. A postoperative compression of the C7 cervical root or the middle trunk of brachial plexus was initially suspected. A cervical MRI demonstrated a T1- and T2-weighted images well-defined right mass located laterally to the spinal cord in the epidural space at the level of C6–C7 vertebrae with a signal-intensity void on both sequences. T2*-weighted images showed no signal attenuation. It did not enhance after contrast administration. An epidural hematoma was less probable since acute hematoma is typically hypointense on T2*-weighted images. Computed tomography helped rule out residual postoperative air trapped in the epidural space based on the density study of the mass compared to air. Finally, a residual surgical foreign material used for packing during the procedure was suspected. The massive use of bone wax was ultimately confirmed by the surgeon and surgically removed with complete immediate postoperative recovery. Conclusions This case highlights the importance of a nuanced critical approach of neurosurgeons and neuroradiologists when interpreting postoperative neuroimaging scans of the spine. It is crucial to always consider foreign body-related complications and to review the per-operative procedure in details

Development of an Asymmetric Ultrafiltration Membrane from Naturally Occurring Kaolin Clays: Application for the Cuttlefish Effluents Treatment

International audienc

Development and characterization of porous membranes based on kaolin/chitosan composite

International audienc

Effectiveness, safety and drug survival of tumor necrosis factor-α inhibitors in the treatment of spondyloarthritis: A real-life study in Tunisia

Aim of the work: The aim of the present study was to evaluate effectiveness of anti-tumor necrosis factor-α (anti-TNFα) in the treatment of spondyloarthritis (SpA) and to assess their safety and drug survival. Patients and methods: Forty-two SpA patients (33 men, 9 women) were retrospectively studied. The disease was progressive in all patients. Response was assessed after 6 months using Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and Functional Index (BASFI) scores and other clinical parameters. A major clinical response was defined as 50% improvement of the initial BASDAI. Patients were grouped into those with ankylosing spondylitis (AS) (24 patients) or psoriatic arthritis (PsA) and enteropathic arthritis (EA) (18 patients) and the response to anti-TNF was compared. Results: The mean age of the patients was 41.3 ± 9.7 years and disease duration 14.6 ± 8.2 years. After 6 months, 74% of patients were BASDAI 50 responders. The mean BASDAI and BASFI scores varied from 56 ± 20 and 61.8 ± 26 to 19 ± 19 and 24 ± 25 respectively (p < .001). The two SpA groups had the same effectiveness profile. The comparison between them showed a greater reduction of morning stiffness duration and erythrocyte sedimentation rate in patients with PsA or EA (p = .04). At least, one adverse event developed by 48% of patients and it was severe in 12%. Bronchopulmonary infections were the most frequent (8 patients). Drug survival rate was estimated at 86% after 1 year of treatment. Conclusion: Anti-TNFα therapy has a good response rate in SpA patients and an acceptable safety profile which explains the high drug survival rates. Keywords: Spondyloarthritis, Anti-TNF, Effectiveness, Safety, Drug surviva