Penelitian bertujuan untuk mengetahui tingkat burnout akademik mahasiswa saat pembelajaran daring. Jenis penelitian menggunakan analisis deskriptif kuantitatif. Subyek penelitian adalah mahasiswa. ...Teknik pengambilan sampel menggunakan simple random sampling. Jumlah responden pada penelitian ini yaitu 73 mahasiswa. Pengumpulan data menggunakan instrumen the copenhagen burnout inverntory student version dan dianalisis menggunakan analisis model RASCH. Nilai Alpha Cronbach yang mengukur interaksi antar item dan person adalah 0,90. Hasil ini menunjukkan bahwa data yang dimiliki sesuai dengan persyaratan pada pemodelan Rasch, sehingga instrument ini layak (reliabel) untuk digunakan. Pembelajaran daring yang dipersiapkan dengan baik dan menggunakan metode yang bervariatif dapat mencegah mahasiswa mengalami burnout akademik.
This study aims to develop design of blended learning model, and then call Blended Cooperative Learning model (BCL). This research is research development. Stages of the research use Thiagarajan, ...Semmel Semmel development model. this study limited by 3 stages. There are the define stage, the design stage, and the developing stage. This research was attended at STIKI Malang in Informatics Engineering students taking Numerical Method courses. Data collection techniques used validation sheets for the design of BCL Model and materials to two validators. Data analysis uses average scoring. The results of this study are design of BCL model and materials. The materials are materials learning in LMS, RPP, and worksheets. The results of this study is design of blended learning Blended Cooperative Learning is feasible to use.
Hypoxia is negatively associated with glioblastoma (GBM) patient survival and contributes to tumour resistance. Anti-angiogenic therapy in GBM further increases hypoxia and activates survival ...pathways. The aim of this study was to determine the role of hypoxia-induced autophagy in GBM.
Pharmacological inhibition of autophagy was applied in combination with bevacizumab in GBM patient-derived xenografts (PDXs). Sensitivity towards inhibitors was further tested in vitro under normoxia and hypoxia, followed by transcriptomic analysis. Genetic interference was done using ATG9A-depleted cells.
We find that GBM cells activate autophagy as a survival mechanism to hypoxia, although basic autophagy appears active under normoxic conditions. Although single agent chloroquine treatment in vivo significantly increased survival of PDXs, the combination with bevacizumab resulted in a synergistic effect at low non-effective chloroquine dose. ATG9A was consistently induced by hypoxia, and silencing of ATG9A led to decreased proliferation in vitro and delayed tumour growth in vivo. Hypoxia-induced activation of autophagy was compromised upon ATG9A depletion.
This work shows that inhibition of autophagy is a promising strategy against GBM and identifies ATG9 as a novel target in hypoxia-induced autophagy. Combination with hypoxia-inducing agents may provide benefit by allowing to decrease the effective dose of autophagy inhibitors.
Chemical contaminants such as heavy metals, dyes, and organic oils seriously affect the environment and threaten human health. About 2 million tons of waste is released every day into the water ...system. Heavy metals are the largest contributor which cover about 31% of the total composition of water contaminants. Every day, approximately 14 000 people die due to environmental exposure to selected chemicals. Removal of these contaminants down to safe levels is expensive, high energy and unsustainable by current approaches such as oxidation, biodegradation, photocatalysis, precipitation, reverse osmosis and adsorption. A combination of biosorption and nanotechnology offers a new way to remediate these chemical contaminants. Nanostructured materials are proven to have higher adsorption capacities than the same material in its larger-scale form. Nanocellulose is very promising as a high-performance bioadsorbent due to its interesting characteristics of high adsorption capacity, high mechanical strength, hydrophilic surface chemistry, renewability and biodegradability. It has been proven to have higher adsorption capacity and better binding affinity than other similar materials at the macroscale. The high specific surface area and abundance of hydroxyl groups within lead to the possible functionalization of this material for decontamination purposes. Several research papers have shown the effectiveness of nanocellulose in the remediation of chemical contaminants. This review aims to provide an overview of the most recent developments regarding nanocellulose as an adsorbent for chemical contamination remediation. Recent advancements regarding the modification of nanocellulose to enhance its adsorption efficiency towards heavy metals, dyes and organic oils were highlighted. Moreover, the desorption capability and environmental issue related to every developed nanocellulose-based adsorbent were also tackled.
The adsorption and desorption of contaminants by nanocellulose.
The enormous demands on available global lithium resources have raised concerns about the sustainability of the supply of lithium. Sodium secondary batteries have emerged as promising alternatives to ...lithium batteries. We describe here sodium bis(trifluoromethylsulfonyl) amide (NaNTf2) electrolyte systems based on 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl) amide (C4mpyrNTf2) ionic liquids. The electrochemical stability of the system was examined; a pair of facile cathodic and anodic processes around 0V vs. Na/Na+ were observed in cyclic voltammetry measurements and interpreted as deposition and dissolution of sodium metal. Density, viscosity and conductivity of the electrolytes were studied. It was found that the ionic conductivity of electrolytes reached as high as 8mS/cm, decreasing slowly as the salt content increased due to increasing of viscosity and density of the electrolyte. Therefore, sodium electrolytes based on C4mpyrNTf2 appear to be promising for secondary sodium battery applications.
Major efforts have been put in anti-angiogenic treatment for glioblastoma (GBM), an aggressive and highly vascularized brain tumor with dismal prognosis. However clinical outcome with anti-angiogenic ...agents has been disappointing and tumors quickly develop escape mechanisms. In preclinical GBM models we have recently shown that bevacizumab, a blocking antibody against vascular endothelial growth factor, induces hypoxia in treated tumors, which is accompanied by increased glycolytic activity and tumor invasiveness. Genome-wide transcriptomic analysis of patient derived GBM cells including stem cell lines revealed a strong up-regulation of glycolysis-related genes in response to severe hypoxia. We therefore investigated the importance of glycolytic enzymes in GBM adaptation and survival under hypoxia, both in vitro and in vivo. We found that shRNA-mediated attenuation of glycolytic enzyme expression interfered with GBM growth under normoxic and hypoxic conditions in all cellular models. Using intracranial GBM xenografts we identified seven glycolytic genes whose knockdown led to a dramatic survival benefit in mice. The most drastic effect was observed for PFKP (PFK1, +21.8%) and PDK1 (+20.9%), followed by PGAM1 and ENO1 (+14.5% each), HK2 (+11.8%), ALDOA (+10.9%) and ENO2 (+7.2%). The increase in mouse survival after genetic interference was confirmed using chemical inhibition of PFK1 with clotrimazole. We thus provide a comprehensive analysis on the importance of the glycolytic pathway for GBM growth in vivo and propose PFK1 and PDK1 as the most promising therapeutic targets to address the metabolic escape mechanisms of GBM.
Enhanced reaction performance is what has piqued interest in using graphene-based catalysts in producing biodiesel. However, in-depth analyses were lacking from a kinetic and thermodynamic ...standpoint. This means that a well-designed experiment is necessary to determine the effect that the graphene catalysts have on the reaction rates and yields. This work addresses the kinetic and thermodynamic aspects of heterogeneously catalyzed transesterification using sulphonated biomass-derived graphene catalysts, i.e., bGO-SO3H and brGO-SO3H. It was accomplished using the pseudo-first order mechanism and the Eyring-Polanyi equation, with all data fitting satisfactorily in both models at the ideal reaction temperature of 353.15 K, resulting in R2 values of 0.9784 (bGO-SO3H) and 0.9884 (brGO-SO3H). The calculated activation energy (Ea) was determined to be 44.45 and 51.73 kJ mol-1 for bGO- and brGO-SO3H, respectively. Additionally, the Gibbs free energy (ΔG) values were determined at −38.09 and −31.81 kJ mol−1 for bGO- and brGO-SO3H, respectively. Meanwhile, the values for ΔH and ΔS were obtained as 41.69 kJ mol−1 and 225.93 J mol−1 K−1, respectively, and 48.96 kJ mol−1 and 228.72 J mol−1 K−1, respectively. These collective outcomes collectively signify the endothermic nature of the reaction and their spontaneity, particularly under elevated temperature conditions.
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•Addresses dynamic nature of bio-graphene catalyst-driven transesterification.•Strong pseudo-first order fits (R2 > 0.97) affirm heterogeneous kinetics.•While Ea suggests a high barrier, it is comparable to other catalysts.•Calculated ΔG supports spontaneous reaction potential.•ΔH and ΔS indicate endothermism and greater disorder at higher temperatures.
Synopsis: Our study investigates kinetic and thermodynamic aspects of bio-based sulphonated graphene catalysts. Pioneering their utilization in microwave-assisted transesterification, we employ palm oil as the feedstock.
•Embarks on novel bio-based graphene catalysts syntheses from biomass.•Unfolds their potential for microwave-assisted transesterification of palm oil.•Exceeding EN14214, the highest 97.45% FAME yield ...is achieved.•Demonstrate lower catalyst usage, temperature, and time than prior studies.
The strategic integration of bio-based catalytic design principles and the intricacies of microwave irradiation offers a viable path to improving the sustainability and efficiency of biodiesel production. In this work, we produced novel biomass-derived sulfonated graphene oxide (bGO-SO3H) and reduced graphene oxide (brGO-SO3H), examining their collaborative effects with microwave irradiation on reaction efficacy. Sulfonation in catalysts was evident through 1) reduced mass loss during thermal decomposition (bGO-SO3H: 34.5 %; brGO-SO3H: 29.4 %) compared to precursors (bGO: 55.6 %; brGO: 20.3 %), indicating decreased oxygen-containing functional groups; 2) higher TPD-acidic sites (bGO-SO3H: 3.17 mmol g−1; brGO-SO3H: 3.24 mmol g−1), supported by titration-acid density (bGO-SO3H: 2.97 mmol g−1; brGO-SO3H: 3.83 mmol g−1); and 3) additional C1s peaks attributed to C-S bonds in sulfonic moieties and a significant increase in sp2 carbon content compared to their precursors, confirmed by ID/IG ratio reduction (bGO-SO3H: 1.09 to 0.98, brGO-SO3H: 0.99 to 0.95). Despite modest surface areas (18–44 m2/g), both catalysts exhibited significantly elevated acid densities (0.05–4.83 mmol g−1) post-sulfonation. Under optimized conditions (2 wt% catalysts, 25:1 methanol-to-oil ratio, 25 min at 75 °C), bGO-SO3H yielded 90.97 % FAME yield, while brGO-SO3H achieved 97.45 % with a reduced dosage (1.5 wt%), shorter time (20 min), and less methanol (20:1). Despite catalytic deactivation, our study demonstrates reduced catalyst consumption, a lower reaction temperature, and a shortened conversion time compared to prior findings, thereby enhancing the efficiency of biodiesel production.
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