Supercritical Carbon Dioxide Isolation of Cellulose Nanofibre and Enhancement Properties in Biopolymer Composites.

The physical properties, such as the fibre dimension and crystallinity, of cellulose nanofibre (CNF) are significant to its functional reinforcement ability in composites. This study used supercritical carbon dioxide as a fibre bundle defibrillation pretreatment for the isolation of CNF from bamboo, in order to enhance its physical properties. The isolated CNF was characterised through zeta potential, TEM, XRD, and FT-IR analysis. Commercial CNF was used as a reference to evaluate the effectiveness of the method. The physical, mechanical, thermal, and wettability properties of the bamboo and commercial CNF-reinforced PLA/chitin were also analysed. The TEM and FT-IR results showed the successful isolation of CNF from bamboo using this method, with good colloidal stability shown by the zeta potential results. The properties of the isolated bamboo CNF were similar to the commercial type. However, the fibre diameter distribution and the crystallinity index significantly differed between the bamboo and the commercial CNF. The bamboo CNF had a smaller fibre size and a higher crystallinity index than the commercial CNF. The results from the CNF-reinforced biocomposite showed that the physical, mechanical, thermal, and wettability properties were significantly different due to the variations in their fibre sizes and crystallinity indices. The properties of bamboo CNF biocomposites were significantly better than those of commercial CNF biocomposites. This indicates that the physical properties (fibre size and crystallinity) of an isolated CNF significantly affect its reinforcement ability in biocomposites. The physical properties of isolated CNFs are partly dependent on their source and production method, among other factors. These composites can be used for various industrial applications, including packaging.

Cotton Wastes Functionalized Biomaterials from Micro to Nano: A Cleaner Approach for a Sustainable Environmental Application.

The exponential increase in textile cotton wastes generation and the ineffective processing mechanism to mitigate its environmental impact by developing functional materials with unique properties for geotechnical applications, wastewater, packaging, and biomedical engineering have become emerging global concerns among researchers. A comprehensive study of a processed cotton fibres isolation technique and their applications are highlighted in this review. Surface modification of cotton wastes fibre increases the adsorption of dyes and heavy metals removal from wastewater. Cotton wastes fibres have demonstrated high adsorption capacity for the removal of recalcitrant pollutants in wastewater. Cotton wastes fibres have found remarkable application in slope amendments, reinforcement of expansive soils and building materials, and a proven source for isolation of cellulose nanocrystals (CNCs). Several research work on the use of cotton waste for functional application rather than disposal has been done. However, no review study has discussed the potentials of cotton wastes from source (Micro-Nano) to application. This review critically analyses novel isolation techniques of CNC from cotton wastes with an in-depth study of a parameter variation effect on their yield. Different pretreatment techniques and efficiency were discussed. From the analysis, chemical pretreatment is considered the most efficient extraction of CNCs from cotton wastes. The pretreatment strategies can suffer variation in process conditions, resulting in distortion in the extracted cellulose's crystallinity. Acid hydrolysis using sulfuric acid is the most used extraction process for cotton wastes-based CNC. A combined pretreatment process, such as sonication and hydrolysis, increases the crystallinity of cotton-based CNCs. The improvement of the reinforced matrix interface of textile fibres is required for improved packaging and biomedical applications for the sustainability of cotton-based CNCs.

Improved Hydrophobicity of Macroalgae Biopolymer Film Incorporated with Kenaf Derived CNF Using Silane Coupling Agent.

Hydrophilic behaviour of carrageenan macroalgae biopolymer, due to hydroxyl groups, has limited its applications, especially for packaging. In this study, macroalgae were reinforced with cellulose nanofibrils (CNFs) isolated from kenaf bast fibres. The macroalgae CNF film was after that treated with silane for hydrophobicity enhancement. The wettability and functional properties of unmodified macroalgae CNF films were compared with silane-modified macroalgae CNF films. Characterisation of the unmodified and modified biopolymers films was investigated. The atomic force microscope (AFM), SEM morphology, tensile properties, water contact angle, and thermal behaviour of the biofilms showed that the incorporation of Kenaf bast CNF remarkably increased the strength, moisture resistance, and thermal stability of the macroalgae biopolymer films. Moreover, the films' modification using a silane coupling agent further enhanced the strength and thermal stability of the films apart from improved water-resistance of the biopolymer films compared to unmodified films. The morphology and AFM showed good interfacial interaction of the components of the biopolymer films. The modified biopolymer films exhibited significantly improved hydrophobic properties compared to the unmodified films due to the enhanced dispersion resulting from the silane treatment. The improved biopolymer films can potentially be utilised as packaging materials.

Recurrent Psychotic Episodes with a Near-monthly Cycle.

A 12-year-old girl presented to the mental health service for an abrupt onset of mental changes characterised by hearing voices and being paranoid. She appeared preoccupied and her mood was labile. There was no family history of mental illness, and no organic causes were identified. These symptoms subsided spontaneously in a week. However, she experienced 3 other similar psychotic episodes afterwards which happened in a near-monthly cycle. Her level of functioning was normal between these episodes. Throughout the course of the illness, it was noted that these mental state changes might be related to the menstrual cycle. In this case we discuss the recurrent periodic psychoses in adolescents and the important differential diagnoses to be considered, including menstrual psychosis, a rare and less well-understood clinical entity.

Delayed endoscopic retrograde cholangiopancreatography is associated with persistent organ failure in hospitalised patients with acute cholangitis.

BACKGROUND: Predictors of organ failure and the impact of early endoscopic retrograde cholangiopancreatography (ERCP) on outcomes in patients with acute cholangitis are unclear. AIM: To identify factors associated with persistent organ failure and assess the impact of early ERCP on outcomes in hospitalised patients with cholangitis. METHODS: Consecutive hospitalised patients who received ERCP at two centres for cholangitis from 4/2005-3/2013 were retrospectively reviewed. Delayed ERCP was defined as ERCP ≥ 48 h after hospitalisation. Primary outcome was persistent organ failure at >48 h after hospitalisation (≥ 1.5 times rise in creatinine levels from baseline values to ≥ 1.5 mg/dL or need for dialysis, mechanical ventilation and/or hypotension requiring vasopressor). RESULTS: 203 patients (mean age 59 ± 19 years) had ERCP for cholangitis: 115 with choledocholithiasis, 48 with other benign obstructions and 40 with malignant strictures. Forty-five (22%) patients had persistent organ failure at >48 h and 11 (5%) died. On multivariate analysis, Charlson Comorbidity Index >2 (OR = 4.6, 95% CI = 1.5-13.8), systemic inflammatory response syndrome (SIRS; OR = 3.2, 95% CI = 1.1-9.8), hypoalbuminemia (OR = 3.3, 95% CI = 1.4-7.9), bacteremia (OR = 2.8, 95% CI 1.3-6.2) and delayed ERCP(OR = 3.1, 95% CI: 1.4-7.0) were associated with persistent organ failure. Every 1-day delay in ERCP was associated with a 17% (95% CI = 5-29%) relative risk increase in persistent organ failure after adjusting for significant factors. CONCLUSIONS: Delay in ERCP beyond 48 h was associated with persistent organ failure in hospitalised patients with acute cholangitis. Other factors included increased comorbidities, SIRS, hypoalbuminemia and bacteremia. Early ERCP performed within 48 h after presentation in patients with cholangitis may improve outcomes.

Utilization of antiepileptic drugs in Hong Kong children.

This study investigated the prescribing patterns of antiepileptic drugs, especially the uptake of newer drugs, among children and adolescents in Hong Kong. Data were retrieved from the Clinical Data Analysis and Reporting System. Children aged 0-19 years who received at least one prescription of anticonvulsants were selected. The study period extended from April 1, 2005 to March 31, 2009. The overall prevalence of anticonvulsants prescribing was 2.23/1000 children in 2005. A slight but steady decline in anticonvulsants prevalence was observed throughout the study period. Valproic acid was the most frequently prescribed drug, followed by carbamazepine and benzodiazepine derivatives. The use of newer anticonvulsants rose significantly, by 26.9%. The use of valproic acid remained unchanged, whereas the use of carbamazepine declined by 20%. Among newer drugs, the use of levetiracetam increased fourfold, and that of oxcarbazepine increased 15-fold. In the youngest age group, phenobarbital was the second most frequently used drug. A significant increase in lamotrigine prescriptions was not observed among adolescents. The persistent increase in using newer antiepileptic drugs implies not only an increase in drug expenditure. It also reflects the need to assess cost-effectiveness in terms of long-term outcomes, quality of life, and health economic outcomes.

Practical limitations of convalescent plasma collection: a case scenario in pandemic preparation for influenza A (H1N1) infection.

BACKGROUND: To ensure a good preparedness for pandemic influenza A (H1N1), a study was conducted to investigate clinical effectiveness of hyperimmune intravenous globulin (H-IVIG) prepared from convalescent plasma donated by recovered patients. This article reports on the outcome of the collection phase of the study. STUDY DESIGN AND METHODS: Starting on August 26, 2009, all confirmed patients aged between 18 and 55 years were invited for participation into the study and screen for plasma donation eligibility. Effective September 17, 2009, those who were unwilling to consider screening for plasma were asked to donate whole blood. Plasma collected or separated from whole blood had to demonstrate sufficient neutralization antibodies titers of 40 or more before being channeled for H-IVIG production. RESULTS: By October 31, 2009, a total of 9101 persons were successfully contacted. A total of 1309 screening and 619 whole blood donation appointments were made. In the former 786 (60.0%) attended screening but only 301 could donate plasma by apheresis because of failure to meet blood donation eligibility criteria, failed laboratory tests, insufficient neutralization antibody titers, and inability to make the apheresis appointment. For those who opted for whole blood donation, 379 (61.2%) had attended and donated. A total of 276 L of convalescent plasma with sufficient neutralization antibodies titers was collected for H-IVIG production. DISCUSSION: The study highlighted a number of practical limitations in convalescent plasma collection programs and plasmapheresis is always the preferred mode of collection. It provided valuable learning experience for the blood transfusion service in future planning when large-scale collection is required.

Effect of anti-CD52 antibody alemtuzumab on ex-vivo culture of umbilical cord blood stem cells.

BACKGROUND: Excessive maturation of hematopoietic cells leads to a reduction of long-term proliferative capability during cord blood (CB) expansion. In this study, we report the effects of anit-CD52 (Alemtuzumab, Campath) on both short- and long-term ex vivo expansion of CB hematopoietic stem cells (HSC) by evaluating the potential role of Alemtuzumab in preserving the repopulating capability in CB HSC and nonlymphoid progenitors. METHODS: Ex vivo expansion experiments were carried out using freshly purified CB CD34(+)cells in StemSpantrade mark SFEM medium in the presence of stem cell factor, Flt3-Ligand and thrombopoietin at 50 ng/ml. Alemtuzumab (10 microg/ml) was used to deplete CD52(+) cells during the cultures. Flow cytometry was used to monitor CB HSC and their differentiation. Colony forming unit (CFU) assays and long term culture-initiating cell (LTC-IC) assays were performed on cells obtained from day 0 (before culture) and day 14 after cultures. Secondary cultures was performed using CD34(+) cells isolated at 35 days from primary cultures and further cultured in StemSpantrade mark SFEM medium for another 14 days to confirm the long term effect of alemtuzumab in liquid cultures. RESULTS: Compared to cytokines alone, addition of alemtuzumab resulted in a significant increase in total nucleated cells, absolute CD34(+) cells, myeloid and megakaryocytic progenitors, multi-lineage and myeloid CFU and LTC-IC. CONCLUSION: The results from current study suggested that the use of alemtuzumab for ex vivo expansion of CBHSC maybe advantageous. Our findings may improve current technologies for CBHSC expansion and increase the availability of CB units for transplantation. However, in vivo studies using animal models are likely needed in further studies to test the hematopoietic effects using such expanded CB products.

Tagging and mapping of rice sheath blight resistant gene.

Sheath blight (Rhizoctonia solani Kühn) is one of the severe rice diseases worldwide. In this study, an F(2) population from a cross between "4011" and "Xiangzaoxian19" is used to identify molecular markers linked with the resistant trait. "4011" was a transgenic rice cultivar carrying a resistant gene to sheath blight, while "Xiangzaoxian19" is a highly susceptible one. As a result, five molecular markers, including three RFLP markers converted from RAPD and AFLP markers, and two SSR markers were identified to link with the sheath blight resistant gene. This dominant resistant gene was named as R sb 1 and mapped on rice chromosome 5. The linkage distance between the markers (E-AT:M-CAC(120), E-AT:M-CTA(230), OPN-16(2000), RM164(320) and RM39(300)) and R sb 1 was 1.6 cM, 9.9 cM, 1.6 cM, 15.2 cM and 1.6 cM, respectively.