JURNAL AGROTEKNOLOGI
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Produksi Xilosa dari Xilan Limbah Ampas Singkong Menggunakan Bacillus subtilis, Aureobasidium pullulans, dan Penicillium janczewskii: PRODUKSI XILOSA DARI XILAN LIMBAH AMPAS SINGKONG
Full text linkThe demand for xylose as a xylitol raw material is increasing. The resource for this material can be explored from agricultural waste such as lignocellulosic material which is widely available in nature, cheap, and renewable. The bioconversion of lignocellulose waste into xylose can use microbes, either single culture or microbial consortia. The purpose of this research is to find out the ability of Bacillus subtilis, Aureobasidium pullulans, and Penicillium janczewskii to convert xylan of cassava waste to produce xylose, under both single individual culture and its consortia. The xylose release from the cultures were measured using DNS tests followed by HPLC determination. The results showed that the single microbial culture of B. subtilis, A. pullulans, and P. janczewskii was able to produce xylose released into the culture broth which was 75.06, 81.72, and 82.00 ppm respectively, indicating the xylanolytic enzymes activities from this microorganism which have the ability to convert xylan into xylose. Unexpectedly, all the mix culture of these microbial consortia were unable to produce higher xylose, the amount of xylose released were even lower became 63.11 ppm only when B. subtilis, A. pullulans, and P. janczewskii worked together in a simultaneous culture. This finding indicated that these three microorganisms might not be able to hydrolysed the xylan synergistically.
Keywords: bioconversion, lignocellulosic material, microbial consortia, xylanolytic enzym
Mutu Fisik Bubuk Kunyit (Curcuma domestica Val.) Hasil Pengeringan Microwave Berdasarkan Proses Blanching yang Berbeda
Full text linkCurcuma domestica Val. is a kind of spice that can be processed become several kinds of processed products such as flavor and herb. The height of water content and water activity in Curcuma causes damage and decrease of curcuma quality. One of the correct handles to get qualified products with good quality and to decrease the damage is by doing blanching process and drainage using the microwave. This study aimed to determine the physical quality characteristics of dried turmeric based on the difference in microwave power and the type of blanching process. The experiment used in this study was a completely randomized design with two factors, namely: microwave power (307, 402, and 577 W) and types of blanching (hot water and steam). The data obtained was characteristic of the physical quality of turmeric powder comprising color, agglomeration angle, precipitation density, water absorption, and oil absorption. The result of the study indicated that the water content of fresh turmeric was between 92.11-94.41% and the dried turmeric was between 3.48-4.56%. The characteristic of physical quality of turmeric powder has brightness level (L) between 61.1-66.5; reddish level (a) between 13.2-18.; yellowish level (b) between 40.8-53.0; precipitation density between 0.31-0.36 g/cm3; agglomeration angle between 42.7o-46.1o; the water absorption between 4.6-5.8 mL/g; and the oil absorption between 1.43-1.63 mL/g. Microwave-dried turmeric powder with both blanching processes produced physical quality that met SNI 01-7084-1995 standards with brightness, reddish, yellowish level, bulk density, and agglomeration angle in steam blanching process higher than hot water blanching.
Keywords: completely randomized design, drying, hot water, steam, turmeric powde
Physical and mental health 3 months after SARS-CoV-2 infection (long COVID) among adolescents in England (CLoCk): a national matched cohort study
No full textBackground: We describe post-COVID symptomatology in a non-hospitalised, national sample of adolescents aged 11–17 years with PCR-confirmed SARS-CoV-2 infection compared with matched adolescents with negative PCR status.
Methods: In this national cohort study, adolescents aged 11–17 years from the Public Health England database who tested positive for SARS-CoV-2 between January and March, 2021, were matched by month of test, age, sex, and geographical region to adolescents who tested negative. 3 months after testing, a subsample of adolescents were contacted to complete a detailed questionnaire, which collected data on demographics and their physical and mental health at the time of PCR testing (retrospectively) and at the time of completing the questionnaire (prospectively). We compared symptoms between the test-postive and test-negative groups, and used latent class analysis to assess whether and how physical symptoms at baseline and at 3 months clustered among participants. This study is registered with the ISRCTN registry (ISRCTN 34804192).
Findings: 23 048 adolescents who tested positive and 27 798 adolescents who tested negative between Jan 1, 2021, and March 31, 2021, were contacted, and 6804 adolescents (3065 who tested positive and 3739 who tested negative) completed the questionnaire (response rate 13·4%). At PCR testing, 1084 (35·4%) who tested positive and 309 (8·3%) who tested negative were symptomatic and 936 (30·5%) from the test-positive group and 231 (6·2%) from the test-negative group had three or more symptoms. 3 months after testing, 2038 (66·5%) who tested positive and 1993 (53·3%) who tested negative had any symptoms, and 928 (30·3%) from the test-positive group and 603 (16·2%) from the test-negative group had three or more symptoms. At 3 months after testing, the most common symptoms among the test-positive group were tiredness (1196 [39·0%]), headache (710 [23·2%]), and shortness of breath (717 [23·4%]), and among the test-negative group were tiredness (911 [24·4%]), headache (530 [14·2%]), and other (unspecified; 590 [15·8%]). Latent class analysis identified two classes, characterised by few or multiple symptoms. The estimated probability of being in the multiple symptom class was 29·6% (95% CI 27·4–31·7) for the test-positive group and 19·3% (17·7–21·0) for the test-negative group (risk ratio 1·53; 95% CI 1·35–1·70). The multiple symptoms class was more frequent among those with positive PCR results than negative results, in girls than boys, in adolescents aged 15–17 years than those aged 11–14 years, and in those with lower pretest physical and mental health.
Interpretation: Adolescents who tested positive for SARS-CoV-2 had similar symptoms to those who tested negative, but had a higher prevalence of single and, particularly, multiple symptoms at the time of PCR testing and 3 months later. Clinicians should consider multiple symptoms that affect functioning and recognise different clusters of symptoms. The multiple and varied symptoms show that a multicomponent intervention will be required, and that mental and physical health symptoms occur concurrently, reflecting their close relationship.
Funding: UK Department of Health and Social Care, in their capacity as the National Institute for Health Research, and UK Research and Innovation
Evaluation of acute supplementation with the ketone ester (R)-3-hydroxybutyl-(R)-3-hydroxybutyrate (deltaG) in healthy volunteers by cardiac and skeletal muscle 31P magnetic resonance spectroscopy
No full textIn this acute intervention study, we investigated the potential benefit of ketone supplementation in humans by studying cardiac phosphocreatine to adenosine-triphosphate ratios (PCr/ATP) and skeletal muscle PCr recovery using phosphorus magnetic resonance spectroscopy (31P-MRS) before and after ingestion of a ketone ester drink. We recruited 28 healthy individuals: 12 aged 23–70 years for cardiac 31P-MRS, and 16 aged 60–75 years for skeletal muscle 31P-MRS. Baseline and post-intervention resting cardiac and dynamic skeletal muscle 31P-MRS scans were performed in one visit, where 25 g of the ketone monoester, deltaG®, was administered after the baseline scan. Administration was timed so that post-intervention 31P-MRS would take place 30 min after deltaG® ingestion. The deltaG® ketone drink was well-tolerated by all participants. In participants who provided blood samples, post-intervention blood glucose, lactate and non-esterified fatty acid concentrations decreased significantly (−28.8%, p ≪ 0.001; −28.2%, p = 0.02; and −49.1%, p ≪ 0.001, respectively), while levels of the ketone body D-beta-hydroxybutyrate significantly increased from mean (standard deviation) 0.7 (0.3) to 4.0 (1.1) mmol/L after 30 min (p ≪ 0.001). There were no significant changes in cardiac PCr/ATP or skeletal muscle metabolic parameters between baseline and post-intervention. Acute ketone supplementation caused mild ketosis in blood, with drops in glucose, lactate, and free fatty acids; however, such changes were not associated with changes in 31P-MRS measures in the heart or in skeletal muscle. Future work may focus on the effect of longer-term ketone supplementation on tissue energetics in groups with compromised mitochondrial function
Fly Cell Atlas: a single-nucleus transcriptomic atlas of the adult fruit fly
No full textThe fruit fly Drosophila melanogaster has served as a premier model organism for discovering fundamental and evolutionarily conserved biological mechanisms. Combining recent advances in single-cell sequencing with powerful fly genetic tools holds great promise for making further discoveries. Li et al. present a single-cell atlas of the entire adult fly that includes 580,000 cells and more than 250 annotated cell types. Cells from the head and body recapitulated cell types from 15 dissected tissues. In-depth analyses revealed rare cell types, cell-type-specific gene signatures, and sexual dimorphism. This atlas provides a resource for the Drosophila community to study genetic perturbations and diseases at single-cell resolution. —BA
LaLaLoc: latent layout localisation in dynamic, unvisited environments
No full textWe present LaLaLoc to localise in environments without the need for prior visitation, and in a manner that is robust to large changes in scene appearance, such as a full rearrangement of furniture. Specifically, LaLaLoc performs localisation through latent representations of room layout. LaLaLoc learns a rich embedding space shared between RGB panoramas and layouts inferred from a known floor plan that encodes the structural similarity between locations. Further, LaLaLoc introduces direct, cross-modal pose optimisation in its latent space. Thus, LaLaLoc enables fine-grained pose estimation in a scene without the need for prior visitation, as well as being robust to dynamics, such as a change in furniture configuration. We show that in a domestic environment LaLaLoc is able to accurately localise a single RGB panorama image to within 8.3cm, given only a floor plan as a prior
Mapping inhibitory sites on the RNA polymerase of the 1918 pandemic influenza virus using nanobodies
No full textInfluenza A viruses cause seasonal epidemics and global pandemics, representing a considerable burden to healthcare systems. Central to the replication cycle of influenza viruses is the viral RNA-dependent RNA polymerase which transcribes and replicates the viral RNA genome. The polymerase undergoes conformational rearrangements and interacts with viral and host proteins to perform these functions. Here we determine the structure of the 1918 influenza virus polymerase in transcriptase and replicase conformations using cryo-electron microscopy (cryo-EM). We then structurally and functionally characterise the binding of single-domain nanobodies to the polymerase of the 1918 pandemic influenza virus. Combining these functional and structural data we identify five sites on the polymerase which are sensitive to inhibition by nanobodies. We propose that the binding of nanobodies at these sites either prevents the polymerase from assuming particular functional conformations or interactions with viral or host factors. The polymerase is highly conserved across the influenza A subtypes, suggesting these sites as effective targets for potential influenza antiviral development
Micromechanical properties of vapour-exposed SiCf/BN/SiC ceramic-matrix composites
No full textSiCf/BN/SiC Ceramic-Matrix Composites are candidate materials for aero-engines, but their interphase stability after potential low-temperature water-vapour exposures during flight cycles is not well known. The examination of these composites exposed for 50, 250 and 500 h at low temperature (65 °C) and 95% relative humidity was therefore performed, in order to understand if resulting oxidation products affected the mechanical properties at the micro-scale. The composites were subject to fibre push-out tests to compare pristine from degraded composites. It was found that whilst the sample exposed for 50 h had no significant change from pristine, the samples exposed for 250 and 500 h had a clear decrease in interfacial shear strengths measured. Parallel studies also revealed that whilst damage was strongly localised, the diffusion of water within the composite was not fully complete at exposure times between 50 and 250 h. The permeability of the CMC was shown to be affected at longer exposure times where differences in mechanical performances even between tows and within tows were noted