119 research outputs found

    Structure and tunable properties of hybrid zeolitic imidazolate frameworks

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    Metal Organic Frameworks (MOFs) are a relatively novel class of nanoporous materials that have shown tremendous promise for application in energy-efficient separations. Thousands of structures of MOFs have been synthesized and studies for facilitating several different separation processes that are vital to the chemical engineering industry. However, much work remains to be done in understanding and exploiting their structure-property relationships. We examine unique structural and functional aspects of MOFs versus other nanoporous materials. The pore size and available adsorption sites in MOFs can be tuned via incorporation of two or more organic linkers in the MOF framework, resulting in a ‘mixed-linker’ material. We have chosen an important family of MOFs known as Zeolitic Imidazolate Frameworks (ZIFs) to highlight different facets of mixed-linker synthesis. Importantly, this work develops different methodologies to study the structure of mixed-linker materials at multiple length-scales, which allows a reliable connection to their molecular adsorption and transport properties. Tunability of properties such as adsorption and diffusion of guest molecules such as water and alcohols in mixed-linker ZIF-8-90 is demonstrated. Microscopic structure elucidation of mixed-linker ZIF-8-90 materials is accomplished using advanced NMR spectroscopy combined with computational modeling of structures and NMR spectra. The effect of synthesis route on the structure and properties of mixed-linker ZIFs is explored by comparing and contrasting solvent assisted linker exchange and de novo synthesis. Mechanistic insight of linker exchange process is studied in detail. A modified linker exchange method is used to repair ZIF crystals that have undergone acid gas damage and restore crystallinity and porosity, thereby increasing their useful lifetime.Ph.D

    Band Sequence - Past, Present and Future

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    Amniotic band sequence (ABS) is a constellation of congenital malformations involving mostly distal extremities, less often craniofacial and visceral defects. It is often characterized by the asymmetry of the organ involvement and can manifest with varying severity. Amniotic band sequence lacks a precise definition and pathogenic mechanism, with the extrinsic theory of “Early amnion rupture sequence†being the most widely accepted hypothesis. Using 3-dimension (3D) or 4-dimension (4D) ultrasound scans, ABS related fetal diagnoses can be made early in pregnancy facilitating fetal interventions. Today with minimally invasive fetal surgery, the amniotic bands can be released to save a limb or to avoid a fetal death due to amniotic band constriction of the umbilical cord. To date, no definite genetic basis has been known for the defects seen in ABS. Published articles; monographs and personal experience in fetal and neonatal diagnosis of ABS have contributed extensively to this review article

    Severe malaria - a case of fatal Plasmodium knowlesi infection with post-mortem findings: a case report.

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    BACKGROUND: Zoonotic malaria caused by Plasmodium knowlesi is an important, but newly recognized, human pathogen. For the first time, post-mortem findings from a fatal case of knowlesi malaria are reported here. CASE PRESENTATION: A formerly healthy 40 year-old male became symptomatic 10 days after spending time in the jungle of North Borneo. Four days later, he presented to hospital in a state of collapse and died within two hours. He was hyponatraemic and had elevated blood urea, potassium, lactate dehydrogenase and amino transferase values; he was also thrombocytopenic and eosinophilic. Dengue haemorrhagic shock was suspected and a post-mortem examination performed. Investigations for dengue virus were negative. Blood for malaria parasites indicated hyperparasitaemia and single species P. knowlesi infection was confirmed by nested-PCR. Macroscopic pathology of the brain and endocardium showed multiple petechial haemorrhages, the liver and spleen were enlarged and lungs had features consistent with ARDS. Microscopic pathology showed sequestration of pigmented parasitized red blood cells in the vessels of the cerebrum, cerebellum, heart and kidney without evidence of chronic inflammatory reaction in the brain or any other organ examined. Brain sections were negative for intracellular adhesion molecule-1. The spleen and liver had abundant pigment containing macrophages and parasitized red blood cells. The kidney had evidence of acute tubular necrosis and endothelial cells in heart sections were prominent. CONCLUSIONS: The overall picture in this case was one of systemic malaria infection that fit the WHO classification for severe malaria. Post-mortem findings in this case were unexpectedly similar to those that define fatal falciparum malaria, including cerebral pathology. There were important differences including the absence of coma despite petechial haemorrhages and parasite sequestration in the brain. These results suggest that further study of knowlesi malaria will aid the interpretation of, often conflicting, information on malaria pathophysiology in humans

    Preparation and characterization of chain-extended bismaleimide/carbon fibre composites

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    This paper presents an experimental study of the influence of the addition of aromatic diamine (MDA) to bismaleimide (BMI) resin on the crystallinity, solubility, melting temperature, and mechanical properties of BMI/carbon composites. The modified BMI was prepared through the chain extension with MDA via Michael addition reaction with molar ratio of 3:2 (BMI:MDA). Both modified and unmodified BMI were characterised for chemical structure, crystallinity, melting temperature, mechanical property, and morphology and fracture behaviour using FTIR, XRD, DSC, UTM, and SEM, respectively. The FTIR results revealed the formation of polymeric chain due to the broad N-H absorption. The modified resin was semicrystalline in nature having low melting temperature and hence showed good processibility. The modification of BMI resulted in decrease of pores and increase of tensile, flexural, and impact properties of the composites. Also, SEM studies of the tensile fractured specimens revealed that modification of BMI resulted in improved resin/fibre interfacial strength

    SUPPORTIVE THERAPY: AN OPTION TO ENHANCE HOST IMMUNITY AGAINST COVID-19

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    The threat posed by COVID 19 outbreak, which is considered to be a global pandemic, is immeasurably affecting all the communities worldwide. COVID-19 is a zoonotic disease, which can affect birds, humans and, other animals. The emergence of this pandemic has been creating a tragic situation worldwide by affecting more people through human-human transmission. The burden (both healthwise and economic) placed by the disease is so huge that any measures to improve the current situation, to fasten up the recovery of already affected patients and, to reduce the risk of death and health deterioration should be considered. Vaccination, being the hope in the scenario, helps in preventing the condition to an extent, but in the absence of availability of a proper drug regimen to fight off COVID 19, the requirement of the need to find a system to control the severity of the infection is a necessity Nutritional supplementation helps in boosting up the immune system especially, vitamins like vitamin C, Vitamin D, Zinc, Omega 3 fatty acids, etc. They also exhibit established immunomodulatory, antiviral as well as anti-inflammatory effects. Pieces of evidence have also highlighted the importance of supportive therapy using nutrient supplements in covid patients as it helps in prominent decreasing of SARS CoV2 load of the virus and also significantly reduces the hospitalization period. Hence the nutritional levels of each of the infected person must be assessed before initiating the anti-viral therapy. The search criteria used were PubMed, Medscape, google scholar, etc. The keywords used to search were COVID 19 Supportive therapy, Vitamin D, Vitamin C, Nutrient supplementation, Host immunity, etc. The range of years is between 1978 and 2021

    FGF-trapping hampers cancer stem-like cells in uveal melanoma

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    Background: Cancer stem-like cells (CSCs) are a subpopulation of tumor cells responsible for tumor initiation, metastasis, chemoresistance, and relapse. Recently, CSCs have been identified in Uveal Melanoma (UM), which represents the most common primary tumor of the eye. UM is highly resistant to systemic chemotherapy and effective therapies aimed at improving overall survival of patients are eagerly required. Methods: Herein, taking advantage from a pan Fibroblast Growth Factor (FGF)-trap molecule, we singled out and analyzed a UM-CSC subset with marked stem-like properties. A hierarchical clustering of gene expression data publicly available on The Cancer Genome Atlas (TCGA) was performed to identify patients' clusters. Results: By disrupting the FGF/FGF receptor (FGFR)-mediated signaling, we unmasked an FGF-sensitive UM population characterized by increased expression of numerous stemness-related transcription factors, enhanced aldehyde dehydrogenase (ALDH) activity, and tumor-sphere formation capacity. Moreover, FGF inhibition deeply affected UM-CSC survival in vivo in a chorioallantoic membrane (CAM) tumor graft assay, resulting in the reduction of tumor growth. At clinical level, hierarchical clustering of TCGA gene expression data revealed a strong correlation between FGFs/FGFRs and stemness-related genes, allowing the identification of three distinct clusters characterized by different clinical outcomes. Conclusions: Our findings support the evidence that the FGF/FGFR axis represents a master regulator of cancer stemness in primary UM tumors and point to anti-FGF treatments as a novel therapeutic strategy to hit the CSC component in UM

    Impact of Additional Chromosomal Aberrations on the Disease Progression of Chronic Myelogenous Leukemia

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    The emergence of additional chromosomal abnormalities (ACAs) in Philadelphia chromosome/BCR-ABL1 positive chronic myeloid leukemia (CML), is considered to be a feature of disease evolution. However, their frequency of incidence, impact on prognosis and treatment response effect in CML is not conclusive. In the present study, we performed a chromosome analysis of 489 patients in different clinical stages of CML, using conventional GTG-banding, Fluorescent in situ Hybridization and Spectral Karyotyping. Among the de novo CP cases, ACAs were observed in 30 patients (10.20%) with lowest incidence, followed by IM resistant CP (16.66%) whereas in AP and BC, the occurrence of ACAs were higher, and was about 40.63 and 50.98%, respectively. The frequency of occurrence of ACAs were compared between the study groups and it was found that the incidence of ACAs was higher in BC compared to de novo and IM resistant CP cases. Likewise, it was higher in AP patients when compared between de novo and IM resistant CP cases, mirroring the fact of cytogenetic evolution with disease progression in CML. In addition, we observed 10 novel and 10 rare chromosomal aberrations among the study subjects. This study pinpoints the fact that the genome of advanced phase patients was highly unstable, and this environment of genomic instability is responsible for the high occurrence of ACAs. Treatment response analysis revealed that compared to initial phases, ACAs were associated with an adverse prognostic effect during the progressive stages of CML. This study further portrayed the cytogenetic mechanism of disease evolution in CML

    The Impact of Diabetes Mellitus in Patients with Chronic Obstructive Pulmonary Disease (COPD) Hospitalization

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    Background: Chronic obstructive pulmonary disease (COPD) is the leading cause of morbidity and mortality worldwide. Diabetes mellitus (DM) has been shown to have adverse inflammatory effects on lung anatomy and physiology. We investigated the impact of DM on COPD patient outcomes during inpatient hospitalization. Methods: We conducted a retrospective analysis using the Nationwide Inpatient Sample (NIS) over the years 2002-2014. Three groups, COPD without diabetes, COPD with diabetes but no complication, and COPD with DM and complication, were analyzed. Results: A total of 7,498,577 were COPD hospitalization; of those, 1,799,637 had DM without complications, and 483,467 had DM with complications. After adjusting for clinical, demographic, and comorbidities, the odds of increased LOS in the COPD/DM with complication were 1.37 (confidence interval (CI): 1.326-1.368), and those of DM without complication were 1.061 (1.052-1.070) when compared with COPD alone. The odds of pneumonia, respiratory failure, stroke, and acute kidney injury were also higher in COPD hospitalizations with DM. Both DM with complication (odds ratio (OR): 0.751 (CI 0.727-0.777)) and DM without complication (OR: 0.635 (CI: 0.596-0.675)) have lesser odds of mortality during hospitalization than with COPD alone. Conclusions: There is a considerable inpatient burden among COPD patients with DM in the United States

    Essential oils as valuable feed additive: A narrative review of the state of knowledge about their beneficial health applications and enhancement of production performances in poultry

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    New research has begun to develop safe and effective alternatives to feed-antibiotics as growth enhancers in response to mounting pressure on the poultry sector to do so. There is a significant demand for poultry products all across the world right now. To achieve this goal, key performance indicators are optimized, such as the rate of chicken growth, the amount of feed used, and the health of the flock as a whole. As a result of this growing need, various alternatives to antibiotics have entered the market. New approaches are desperately needed to keep poultry productivity and efficiency at a high level in the face of mounting pressure to limit the use of antibiotics. Recent years have seen an uptick in interest in the potential of aromatic plant extracts as growth and health boosters in poultry. The great majority of plants' positive effects are accounted for by essential oils (EOs) and other secondary metabolites. EOs have been proven to promote digestive secretion production, improve blood circulation, exert antioxidant qualities, reduce levels of dangerous microbes, and maybe improve the immune status of poultry. EOs are often believed to be safe, non-toxic alternatives because they are all-natural, chemical-free, and devoid of potentially harmful deposits. EOs are extracted from plants, and while there are thousands of them, only approximately 300 have been deemed to have significant commercial value. Many different types of bacteria, viruses, fungi, and parasites are negatively affected by EOs in multiple studies conducted both in vitro and in vivo. The review covers the fundamentals of EOs, their anti-oxidant and immunomodulatory capabilities, their growth-promoting benefits, and their effectiveness against numerous diseases in poultry

    mHealth Series:mHealth project in Zhao County, rural China - Description of objectives, field site and methods

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    BACKGROUND: We set up a collaboration between researchers in China and the UK that aimed to explore the use of mHealth in China. This is the first paper in a series of papers on a large mHealth project part of this collaboration. This paper included the aims and objectives of the mHealth project, our field site, and the detailed methods of two studies. FIELD SITE: The field site for this mHealth project was Zhao County, which lies 280 km south of Beijing in Hebei Province, China. METHODS: We described the methodology of two studies: (i) a mixed methods study exploring factors influencing sample size calculations for mHealth–based health surveys and (ii) a cross–over study determining validity of an mHealth text messaging data collection tool. The first study used mixed methods, both quantitative and qualitative, including: (i) two surveys with caregivers of young children, (ii) interviews with caregivers, village doctors and participants of the cross–over study, and (iii) researchers’ views. We combined data from caregivers, village doctors and researchers to provide an in–depth understanding of factors influencing sample size calculations for mHealth–based health surveys. The second study, a cross–over study, used a randomised cross–over study design to compare the traditional face–to–face survey method to the new text messaging survey method. We assessed data equivalence (intrarater agreement), the amount of information in responses, reasons for giving different responses, the response rate, characteristics of non–responders, and the error rate. CONCLUSIONS: This paper described the objectives, field site and methods of a large mHealth project part of a collaboration between researchers in China and the UK. The mixed methods study evaluating factors that influence sample size calculations could help future studies with estimating reliable sample sizes. The cross–over study comparing face–to–face and text message survey data collection could help future studies with developing their mHealth tools
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