134 research outputs found
Intensified photocatalytic degradation of methylene blue over Fe supported on dendritic fibrous SBA-15: Optimisation, kinetic, isotherm, and reusability
A novel photocatalyst, Fe supported on dendritic fibrous SBA-15 (Fe/DFSBA-15), is synthesised and employed for methylene blue (MB) photocatalytic degradation. The DFSBA-15 was synthesised by applying a microemulsion technique and SBA-15 crystal-seed crystallisation approach. The TEM and FESEM of Fe/DFSBA-15 revealed the revolution of rod-typed SBA-15 into dendritic fibrous-structured (DFSBA-15). The characterisation analyses using FTIR, XRD, BET, PL and UV-Vis DRS, confirmed favourable properties of Fe/DFSBA-15 compared to Fe/SBA-15. Fe/DFSBA-15 exhibits superior properties, attributed to its unique dendritic fibrous morphology that increases the surface area, pore accessibility, and mass transfer. These exceptional features establish it as a highly promising and efficient photocatalyst for diverse applications. Optimisation of MB degradation (Y, %) by using Fe/DFSBA-15 was conducted by employing response surface methodology (RSM) of independent parameters such as catalyst loading (X1, 0.5 – 2.0 g/l), pH (X2, 6 – 10) and initial MB concentration (X3, 10 – 50 mg/l). The model was significant, and MB degradation was optimised at 99.54% (X1 = 1.66 g/l, X2 = 9, and X3 = 27.5 mg/l) along with validation experiments (3.62% error). The research outcome was in agreement with the Langmuir second-order (R2 ≥ 0.99), indicating a predictable trend of the MB degradation process. Interestingly, the excellent degradation and reusability performance of Fe/DFSBA-15 offered a prospective approach for industrial wastewater treatment
Generation and Characterization of Fmr1 Knockout Zebrafish
Fragile X syndrome (FXS) is one of the most common known causes of inherited mental retardation. The gene mutated in FXS is named FMR1, and is well conserved from human to Drosophila. In order to generate a genetic tool to study FMR1 function during vertebrate development, we generated two mutant alleles of the fmr1 gene in zebrafish. Both alleles produce no detectable Fmr protein, and produce viable and fertile progeny with lack of obvious phenotypic features. This is in sharp contrast to published results based on morpholino mediated knock-down of fmr1, reporting defects in craniofacial development and neuronal branching in embryos. These phenotypes we specifically addressed in our knock-out animals, revealing no significant deviations from wild-type animals, suggesting that the published morpholino based fmr1 phenotypes are potential experimental artifacts. Therefore, their relation to fmr1 biology is questionable and morpholino induced fmr1 phenotypes should be avoided in screens for potential drugs suitable for the treatment of FXS. Importantly, a true genetic zebrafish model is now available which can be used to study FXS and to derive potential drugs for FXS treatment
Dopaminergic Neuronal Loss and Dopamine-Dependent Locomotor Defects in Fbxo7-Deficient Zebrafish
Recessive mutations in the F-box only protein 7 gene (FBXO7) cause PARK15, a Mendelian form of early-onset, levodopa-responsive parkinsonism with severe loss of nigrostriatal dopaminergic neurons. However, the function of the protein encoded by FBXO7, and the pathogenesis of PARK15 remain unknown. No animal models of this disease exist. Here, we report the generation of a vertebrate model of PARK15 in zebrafish. We first show that the zebrafish Fbxo7 homolog protein (zFbxo7) is expressed abundantly in the normal zebrafish brain. Next, we used two zFbxo7-specific morpholinos (targeting protein translation and mRNA splicing, respectively), to knock down the zFbxo7 expression. The injection of either of these zFbxo7-specific morpholinos in the fish embryos induced a marked decrease in the zFbxo7 protein expression, and a range of developmental defects. Furthermore, whole-mount in situ mRNA hybridization showed abnormal patterning and significant decrease in the number of diencephalic tyrosine hydroxylase-expressing neurons, corresponding to the human nigrostriatal or ventral tegmental dopaminergic neurons. Of note, the number of the dopamine transporter-expressing neurons was much more severely depleted, suggesting dopaminergic dysfunctions earlier and larger than those due to neuronal loss. Last, the zFbxo7 morphants displayed severe locomotor disturbances (bradykinesia), which were dramatically improved by the dopaminergic agonist apomorphine. The severity of these morphological and behavioral abnormalities correlated with the severity of zFbxo7 protein deficiency. Moreover, the effects of the co-injection of zFbxo7- and p53-specific morpholinos were similar to those obtained with zFbxo7-specific morpholinos alone, supporting further the contention that the observed phenotypes were specifically due to the knock down of zFbxo7. In conclusion, this novel vertebrate model reproduces pathologic and behavioral hallmarks of human parkinsonism (dopaminergic neuronal loss and dopamine-dependent bradykinesia), representing therefore a valid tool for investigating the mechanisms of selective dopaminergic neuronal death, and screening for modifier genes and therapeutic compounds
Recent advances in metal oxide photocatalysts for photocatalytic degradation of organic pollutants: A review on photocatalysts modification strategies
Wastewater from industries that predominantly consist of organic pollutants significantly contributes to water pollution and harms the environment, demanding urgent solutions. Among the available wastewater treatment technologies, photocatalysis has garnered considerable interest due to its high efficiency, cleanliness, and sustainability. However, metal oxide photocatalysts, despite extensive study, possess limitations such as agglomeration, rapid electron-hole recombination, and photo corrosion. These limitations hinder the practical design and synthesis of photocatalysts. To address these challenges, researchers have explored various photocatalyst modification approaches, including doping with noble or non-noble metals, crystal facet engineering, physical deposition, dye sensitization, and the implementation of the Z-scheme photocatalyst system. These modifications aim to enhance the catalytic properties of photocatalysts and improve the degradation of organic pollutants. This review article highlights recent advances in the modification strategies of metal oxide photocatalysts for the photocatalytic degradation of organic pollutants. The future prospect and conclusions were also discussed. This review is expected to provide an in-depth understanding of metal oxide photocatalyst development, thus accelerating the evolution of photocatalytic degradation of pollutants
Idh1-mutated transgenic zebrafish lines: An in-vivo model for drug screening and functional analysis
Introduction The gene encoding isocitrate dehydrogenase 1 (IDH1) is frequently mutated in several tumor types including gliomas. The most prevalent mutation in gliomas is a missense mutation leading to a substitution of arginine with histidine at the residue 132 (R132H). Wild type IDH1 catalyzes oxidative decarboxylation of isocitrate to α-ketoglutarate (α-KG) whereas mutant IDH1 converts α-KG into D2-hydroxyglutarate (D2HG). Unfortunately, there are few in vivo model systems for IDH-mutated tumors to study the effects of IDH1 mutations in tumor development. We have therefore created transgenic zebrafish lines that express various IDH1 mutants. Materials and methods IDH1 mutations (IDH1R132H, IDH1R132C and loss-of-function mutation IDH1G70D), IDH1wildtype or eGFP were cloned into constructs with several brain-specific promoters (Nestin, Gfap or Gata2). These constructs were injected into fertilized zebrafish eggs at the one-cell stage. Results In total more than ten transgenic zebrafish lines expressing various brain-specific IDH1 mutations were created. A significant increase in the level of D2HG was observed in all transgenic lines expressing IDH1R132C or IDH1R132H, but not in any of the lines expressing IDH1wildtype, IDH1G70D or eGFP. No differences in 5-hydroxymethyl cytosine and mature collagen IV levels were observed between wildtype and mutant IDH1 transgenic fish. To our surprise, we failed to identify any strong phenotype, despite increased levels of the oncome-tabolite D2HG. No tumors were observed, even when backcrossing with tp53-mutant fish which suggests that additional transforming events are required for tumor formation. Elevated D2HG levels could be lowered by treatment of the transgenic zebrafish with an inhibitor of mutant IDH1 activity. Conclusions We have generated a transgenic zebrafish model system for mutations in IDH1 that can be used for functional analysis and drug screening. Our model systems help understand the biology of IDH1 mutations and its role in tumor formation
Facile synthesis of fibrous Faujasite Y supported Ni (Ni/FFY) catalyst for hydrogen production via glycerol dry reforming
In this study, the dendritic structure of Ni-supported Fibrous Faujasite Y (Ni/FFY) catalyst was successfully synthesized by employing a hydrothermal-assisted microemulsion system and subsequently tested in glycerol dry reforming to produce syngas. FFY possesses high porosity due to the formation of radial wrinkle fibre observed from TEM analysis. This provides a huge amount of interparticle pores that facilitate the absorption of the molecules within the material under a minimum hindrance, hence boosting the interior surface accessibility of Ni/FFY. This exclusive morphology contributed to the enhancement in the amount of accessible Ni active sites, resulting in the good activity of Ni/FFY (C3H8O3 conversion = 56.28 %, CO yield = 70.14 %, and H2 yield = 49.80 %). The extraordinary physicochemical properties of Ni/FFY and outstanding catalytic performance in glycerol dry reforming proved its capability as a sustainable catalyst in transforming waste byproduct (glycerol) and greenhouse gas (CO2) to clean energy (H2). This finding presents a pioneering fibrous zeolite catalyst for hydrogen generation in glycerol reforming
Multidisciplinary care for people with Parkinson’s disease:the new kids on the block!
INTRODUCTION: Parkinson's disease (PD) is a chronic multisystem disorder that causes a wide variety of motor and non-motor symptoms. Over time, the progressive nature of the disease increases the risk of complications such as falls and loss of independence, having a profound impact on quality of life. The complexity and heterogeneity of symptoms therefore warrant a holistic, multidisciplinary approach. Specific healthcare professionals, e.g. the movement disorders neurologist and the PD nurse specialist, are considered essential members of this multidisciplinary team. However, with our increasing knowledge about different aspects of the disease, other disciplines are also being recognized as important contributors to the healthcare team. Areas covered: The authors describe a selection of these relatively newly-recognized disciplines, including the specialist in vascular medicine, gastroenterologist, pulmonologist, neuro-ophthalmologist, urologist, geriatrician/elderly care physician, palliative care specialist and the dentist. Furthermore, they share the view of a person with PD on how patients and caregivers should be involved in the multidisciplinary team. Finally, they have included a perspective on the new role of the movement disorder neurologist, with care delivery via 'tele-neurology'. Expert commentary: Increased awareness about the potential role of these 'new' professionals will further improve disease management and quality of life of PD patients
Exome sequencing and functional analyses suggest that SIX6 is a gene involved in an altered proliferation-differentiation balance early in life and optic nerve degeneration at old age
Primary open-angle glaucoma (POAG) is a hereditary neurodegenerative disease, characterized by optic nerve changes including increased excavation, notching and optic disc hemorrhages. The excavation can be described by the vertical cup-disc ratio (VCDR). Previously, genome-wide significant evidence for the association of rs10483727 in SIX1-SIX6 locus with VCDR and subsequent POAG was found. Using 1000 genomes-based imputation of four independent population-based cohorts in the Netherlands, we identified a missense variant rs33912345 (His141Asn) in SIX6 associated with VCDR (Pmeta = 7.74 × 10-7, n = 11 473) and POAG (Pmeta = 6.09 × 10-3, n = 292). Exome sequencing analysis revealed another missense variant rs146737847 (Glu129Lys) also in SIX6 associated with VCDR (P = 5.09 × 10-3, n = 1208). These two findings point to SIX6 as the responsible gene for the previously reported association signal. Functional characterization of SIX6 in zebrafish revealed that knockdown of six6b led to a small eye phenotype. Histological analysis showed retinal lamination, implying an apparent normal development of the eye, but an underdeveloped lens, and reduced optic nerve diameter. Expression analysis of morphants at 3 dpf showed a 5.5-fold up-regulation of cdkn2b, a cyclin-dependent kinase inhibitor, involved in cell cycle regulation and previously associated with VCDR and POAG in genome-wide association studies (GWASs). Since both six6b and cdkn2b play a key role in cell proliferation, we assessed the proliferative activity in the eye of morphants and found an alteration in the proliferative pattern of retinal cells. Our findings in humans and zebrafish suggest a functional involvement of six6b in early eye development, and open new insights into the genetic architecture of POAG
A new inducible transgenic mouse model for C9orf72-associated GGGGCC repeat expansion supports a gain-of-function mechanism in C9orf72-associated ALS and FTD
An Ice Age JWST inventory of dense molecular cloud ices
Icy grain mantles are the main reservoir of the volatile elements that link
chemical processes in dark, interstellar clouds with the formation of planets
and composition of their atmospheres. The initial ice composition is set in the
cold, dense parts of molecular clouds, prior to the onset of star formation.
With the exquisite sensitivity of JWST, this critical stage of ice evolution is
now accessible for detailed study. Here we show the first results of the Early
Release Science program "Ice Age" that reveal the rich composition of these
dense cloud ices. Weak ices, including, CO, OCN, CO, OCS,
and COMs functional groups are now detected along two pre-stellar lines of
sight. The CO ice profile indicates modest growth of the icy grains.
Column densities of the major and minor ice species indicate that ices
contribute between 2 and 19% of the bulk budgets of the key C, O, N, and S
elements. Our results suggest that the formation of simple and complex
molecules could begin early in a water-ice rich environment.Comment: To appear in Nature Astronomy on January 23rd, 2023. 33 pages, 16
figures, 3 tables; includes extended and supplemental data sections. Part of
the JWST Ice Age Early Release Science program's science enabling products.
Enhanced spectra downloadable on Zenodo at the following DOI:
10.5281/zenodo.750123
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