Effects of hydrolysis ageing on the performance and dimensional stability of glass-fiber reinforced polyamide 66

Results of an in-depth study of hydrolysis testing on the mechanical performance, weight change, and dimensional stability of injection moulded glass-fiber reinforced polyamide 66 automotive composites are presented. Composite and resin samples have been characterised after conditioning in water-glycol mixtures at 70°C, 120°C and 150°C for a range of times up to 1000 hours. The results reveal that hydrothermal ageing results in significant changes in the mechanical performance, weight, and dimensions of these materials. Mechanical performance after conditioning at different temperatures could be superimposed when considered as a function of the level of fluid absorbed by the composite matrix

Enhancing hydrogen production from steam electrolysis in molten hydroxides via selection of non-precious metal electrodes

© 2020 Hydrogen Energy Publications LLC There are still gaps in the field of reference electrode that is needed to assist electrolysis in high temperature electrolytes (e.g. molten hydroxides) for H2 gas production. This research aims to fill the gaps by preparing Ni/Ni(OH)2 reference electrode and more importantly testing its effectiveness against important performance factors including; ion conducting membrane (e.g. mullite tubes), internal electrolyte composition, working temperature and electrochemical control (e.g. potential scan rate). Then, this reference electrode was used to study the electrocatalytic activity various cheaper working electrode materials including; stainless steel (St.st), Ni, Mo and Ag in comparison with Pt by the means of chronoamperometry and voltammetry. The effect of introducing steam into electrolyte (eutectic mixture of NaOH and KOH) on the electrocatalytic activity of these working electrodes was also studied. It was observed that the potential of hydrogen evolution with different working electrodes followed an order as; Pt > Ni > St. st > Ag > Mo (positive to negative). The performance of each working electrode was confirmed through chronoamperometry for hydrogen evolution at a constant potential of −0.7 V. It was also found in cyclic voltammetry and confirmed by chronoamperometry that the introduction of steam was apparent as increasing the current density at cathodic limit for hydrogen evolution. This study could help to develop non-precious metal electrodes for the production of hydrogen fuel. In future, there will be a potential in the threshold concentration of steam for H2 gas production

3D Arbitrary Channel Fabrication for Lab on a Chip Applications using Chemical Decomposition

This article demonstrate a simple method to use of three-dimensionally (3D) printed molds that are chemically decomposable for rapid fabrication of complex and arbitrary microchannel geometries. These complex microchannel are unachievable through existing soft lithography techniques. The molds are printed directly from hand held 3D printing pen that can print in midair, making rapid prototyping of microfluidic devices possible in hours. PLA based copper filament is used to print the arbitrary channels. The printed channels are then placed inside PDMS and PDMS is cured. The cured sample is then immersed in chemical solution (Acetic Acid + Sodium Chloride+ Hydrogen peroxide), which decomposes the PLA based copper channel thus leaving an empty channel inside the PDMS block. This method enable precise control of various device geometries, such as the profile of the channel cross-section and variable channel diameters in a single device

Tribal Formulations for Treatment of Pain: A Study of the Bede Community Traditional Medicinal Practitioners of Porabari Village in Dhaka District, Bangladesh

The Bedes form one of the largest tribal or indigenous communities in Bangladesh and are popularly known as the boat people or water gypsies because of their preference for living in boats. They travel almost throughout the whole year by boats on the numerous waterways of Bangladesh and earn their livelihood by selling sundry items, performing jugglery acts, catching snakes, and treating village people by the various riversides with their traditional medicinal formulations. Life is hard for the community, and both men and women toil day long. As a result of their strenuous lifestyle, they suffer from various types of pain, and have developed an assortment of formulations for treatment of pain in different parts of the body. Pain is the most common reason for physician consultation in all parts of the world including Bangladesh. Although a number of drugs are available to treat pain, including non-steroidal, steroidal, and narcotic drugs, such drugs usually have side-effects like causing bleeding in the stomach over prolonged use (as in the case of rheumatic pain), or can be addictive. Moreover, pain arising from causes like rheumatism has no proper treatment in allopathic medicine. It was the objective of the present study to document the formulations used by the Bede traditional practitioners for pain treatment, for they claim to have used these formulations over centuries with success. Surveys were conducted among a large Bede community, who reside in boats on the Bangshi River by Porabari village of Savar area in Dhaka district of Bangladesh. Interviews of 30 traditional practitioners were conducted with the help of a semi-structured questionnaire and the guided field-walk method. It was observed that the Bede practitioners used 53 formulations for treatment of various types of pain, the main ingredient of all formulations being medicinal plants. Out of the 53 formulations, 25 were for treatment of rheumatic pain, either exclusively, or along with other types of body pain. A total of 65 plants belonging to 39 families were used in the formulations. The Fabaceae family provided 7 plants followed by the Solanaceae family with 4 plants. 47 out of the 53 formulations were used topically, 5 formulations were orally administered, and 1 formulation had both topical and oral uses. 8 formulations for treatment of rheumatic pain contained Calotropis gigantea, suggesting that the plant has strong potential for further scientific studies leading to discovery of novel efficacious compounds for rheumatic pain treatment

Medicinal plants used for treatment of diabetes by the marakh sect of the Garo tribe living in Mymensingh district, Bangladesh

Diabetes mellitus is an endocrinological disorder arising from insulin deficiency or due to ineffectiveness of the insulin produced by the body. This results in high blood glucose and with time, to neurological, cardiovascular, retinal and renal complications. It is a debilitating disease and affects the population of every country of the world. Around 200 million people of the world suffer from this disease and this figure is projected to rise to 300 million in the coming years. The disease cannot becured with allopathic medicine as the drugs used do not restore normal glucose homeostasis and moreover have side-effects. On the other hand, traditional medicinal practitioners of various countries claim to cure diabetes or at least alleviate the major symptoms and progression of this disease through administration of medicinal plants. The Garos are an indigenous community of Bangladesh, who still follow their traditional medicinal practices. Their traditional medicinal formulations contain a number of plants, which they claim to be active antidiabetic agents. Since observation of indigenous practices have led to discovery of manymodern drugs, it was the objective of the present study to conduct a survey among the Marakh sect of the Garos residing in Mymensingh district of Bangladesh to find out the medicinal plants that they use for treatment of diabetes. It was found that the tribal practitioners of the Marakh sect of the Garos use twelve medicinal plants for treatment of diabetes. These plants were Lannea coromandelica, Alstonia scholaris, Catharanthus roseus, Enhydra fluctuans, Terminalia chebula, Coccinia grandis, Momordica charantia, Cuscuta reflexa, Phyllanthus emblica, Syzygium aqueum, Drynaria quercifolia, and Clerodendrum viscosum. A review of the scientific literature demonstrated that almost all the plants used by the Garo tribal practitioners have reported antidiabetic and/or antioxidant properties and have enormous potential for possible development of new and efficacious antidiabetic drugs

Survey and scientific evaluation of medicinal plants used by the Pahan and Teli tribal communities of Natore district, Bangladesh

The Pahans and the Telis are two of the smallest indigenous communities in Bangladesh. The Pahans, numbering about 14,000 people are widely scattered in several northern districts of the country, while the Telis are such a small community that nothing has been reported on their numbers and lifestyle. Both tribes are on the verge of disappearance. One each of the Pahan and the Teli community was located after much search in two adjoining villages of Natore district, Bangladesh. Since the tribes were found to still depend on their traditional medicinal practitioners for treatment of ailments, it was the objective of the present study to document their traditional usage of medicinal plants and to evaluate such plants against modern research-based pharmacological activity studies on these plants. Interviews were conducted of the practitioners of the Pahan and Teli community of Natore district with the help of a semi-structured questionnaire and using the guided field-walk method. Plant specimens aspointed out by the practitioners were collected and pressed on the field and identification completed at the Bangladesh National Herbarium. The Pahan tribal practitioners used 13 plants distributed into 9 families for treatment of 14 different ailments. The Teli tribal practitioner used 15 plants divided into 14 families for treatment of 17 different ailments. Eight out of the thirteen plants used by the Pahan tribal practitioner (61.5%) had reported relevant pharmacological activities in the scientific literature, while six out of the fifteen plants used by the Teli tribal practitioners (40%) had such relevant pharmacological activities in accordance with their usage. The medicinal plants used by the Pahans and Telis warrant further scientific studies toward discovery of lead compounds and efficacious drugs and the documentation and protection of the traditional medical knowledge held by these tribes

Tetranucleotide and Low Microsatellite Instability Are Inversely Associated with the CpG Island Methylator Phenotype in Colorectal Cancer

MSH3 gene or protein deficiency or loss-of-function in colorectal cancer can cause a DNA mismatch repair defect known as “elevated microsatellite alterations at selected tetranucleotide repeats” (EMAST). A high percentage of MSI-H tumors exhibit EMAST, while MSI-L is also linked with EMAST. However, the distribution of CpG island methylator phenotype (CIMP) within the EMAST spectrum is not known. Five tetranucleotide repeat and five MSI markers were used to classify 100 sporadic colorectal tumours for EMAST, MSI-H and MSI-L according to the number of unstable markers detected. Promoter methylation was determined using methylation-specific PCR for MSH3, MCC, CDKN2A (p16) and five CIMP marker genes. EMAST was found in 55% of sporadic colorectal carcinomas. Carcinomas with only one positive marker (EMAST-1/5, 26%) were associated with advanced tumour stage, increased lymph node metastasis, MSI-L and lack of CIMP-H. EMAST-2/5 (16%) carcinomas displayed some methylation but MSI was rare. Carcinomas with ≥3 positive EMAST markers (13%) were more likely to have a proximal colon location and be MSI-H and CIMP-H. Our study suggests that EMAST/MSI-L is a valuable prognostic and predictive marker for colorectal carcinomas that do not display the high methylation phenotype CIMP-H

Guillain-Barré syndrome following varicella-zoster virus infection

We describe the frequency, clinical features, and electrophysiological and immunological phenotypes of Guillain-Barré Syndrome (GBS) patients treated at a single institution in Bangladesh who had preceding chicken pox (primary Varicella-zoster virus [VZV] infection) within 4 weeks of GBS onset. A literature review of GBS cases preceding VZV infection is also provided. Diagnosis of GBS was based on the National Institute of Neurological Disorders and Stroke criteria for GBS. Serum anti-VZV IgM and IgG antibodies were quantified by indirect chemiluminescence immunoassay (CLIA); anti-Campylobacter jejuni IgG, IgM, and IgA antibodies and anti-ganglioside GM1 IgM and IgG antibodies, by enzyme-linked immunosorbent assays. Neurophysiologic subtypes were categorized following the Hadden criteria. Of 536 patients with GBS, 7 (1.3%) had chicken pox within 4 weeks before GBS onset. Four of the seven cases were male (age range, 23 to 40 years old). All seven patients were bed-bound, six had sensory symptoms, and three required mechanical ventilation for respiratory failure. All seven patients had CSF albuminocytologic dissociation and evidence of demyelination in nerve conduction studies. Anti-VZV IgM antibodies were present and anti-GM1 and anti-Campylobacter jejuni lipo-oligosaccharides (LOS) were negative in all cases. All patients had excellent outcome at 1 year (able to run). A systematic literature review of GBS cases related to VZV revealed 39 previously reported patients with comparable clinical presentations and outcomes, of which 36 had neurophysiologic evidence of demyelination. VZV infection is associated with the demyelinating subtype of GBS, clearly distinct from the axonal form of GBS that predominate in countries like Bangladesh