141 research outputs found
Statistical optimization of substrate, carbon and nitrogen source by response surface methodology for pectinase production using Aspergillus fumigatus MTCC 870 in submerged fermentation
Optimization procedure using response surface methodology (RSM) based on face centered central composite design (FCCCD) with three factors (concentrations of wheat flour, glucose and ammonium nitrate) was used in order to investigate the effect of these parameters on the production of pectinase from Aspergillus fumigatus MTCC 870. According to the results of RSM, concentrations of wheat flour, glucose and ammonium nitrate were significant (
Screening of natural substrates and optimization of operating variables on the production of pectinase by submerged fermentation using Aspergillus niger MTCC 281
Pectinases are a group of hydrolytic enzymes that play an important role in food processing industry and alcoholic beverage industry. The present work aims at studying different natural substrates suchas wheat flour and corn flour in comparison with synthetic pectin for the production of pectinase using Aspergillus niger (MTCC: 281). The work involves optimizing various parameters like substrate concentration, pH, temperature, rpm, time of fermentation for the production of pectinase and the effect of carbon sources on the synthesis of the pectinase enzyme to suggest a plausible, commercially suitable substrate than the standard. The experimental studies indicate that maximum synthesis of pectinase (6.1 U/mL) was obtained with A. niger (MTCC: 281) by using wheat as substrate under the influence of the additional carbon source, starch. The optimal conditions are found to be substrate concentration - wheat (1%), pH 5.5, temperature 30°C, time 72 h, rpm 170, and carbon source starch(0.025%)
Ultra-bright gamma-ray emission and dense positron production from two laser-driven colliding foils
Matter can be transferred into energy and the opposite transformation is also possible by use of high-power lasers. A laser pulse in plasma can convert its energy into γ-rays and then e −e + pairs via the multi-photon Breit-Wheeler process. Production of dense positrons at GeV energies is very challenging since extremely high laser intensity ∼ 1024 Wcm−2 is required. Here we propose an all-optical scheme for ultra-bright γ-ray emission and dense positron production with lasers at intensity of 1022−23 Wcm−2 . By irradiating two colliding elliptically-polarized lasers onto two diamondlike carbon foils, electrons in the focal region of one foil are rapidly accelerated by the laser radiation pressure and interact with the other intense laser pulse which penetrates through the second foil due to relativistically induced foil transparency. This symmetric configuration enables efficient Compton back-scattering and results in ultra-bright γ-photon emission with brightness of ∼ 1025 photons/s/mm2 /mrad2 /0.1%BW at 15 MeV and intensity of 5×1023 Wcm−2 . Our first three-dimensional simulation with quantum-electrodynamics incorporated shows that a GeV positron beam with density of 2.5×1022 cm−3 and flux of 1.6×1010/shot is achieved. Collective effects of the pair plasma may be also triggered, offering a window on investigating laboratory astrophysics at PW laser facilities
Effect of sodium chloride stress on the pigment and biochemical variation of pigeon pea (Cajanus cajan (L.) Millsp.)
In the present study, a pot culture experiment was conducted to estimate the effect on NaCl stressed Pigeon pea (Cajanus cajan (L.) Millsp.) the plant belongs to family Fabaceae, is a sub tropical crop, grown world wide particularly in south Asia for edible and fodder purposes, while little is known about its salinity tolerance. The seed were sown in plastic pots from 30 days after sowing (DAS), the plants were treated with 25mM, 50mM, 75mM and 100mM sodium chloride on 20th, 30th and 40th DAS. The plants samples were collected from 30th, 40th and 50th DAS. The leaf were collected for estimating pigment and biochemical content. The sodium chloride treatment decreased the chlorophyll-a, b, total chlorophyll and protein content. Similarly the amino acid and proline content were increased with increasing concentration of NaCl to a larger extent when compared to control in all the treatment day
Brain Structural Networks Associated with Intelligence and Visuomotor Ability
Increasing evidence indicates that multiple structures in the brain are associated with intelligence
and cognitive function at the network level. The association between the grey matter (GM) structural
network and intelligence and cognition is not well understood. We applied a multivariate approach
to identify the pattern of GM and link the structural network to intelligence and cognitive functions.
Structural magnetic resonance imaging was acquired from 92 healthy individuals. Source-based
morphometry analysis was applied to the imaging data to extract GM structural covariance. We
assessed the intelligence, verbal fluency, processing speed, and executive functioning of the
participants and further investigated the correlations of the GM structural networks with intelligence
and cognitive functions. Six GM structural networks were identified. The cerebello-parietal component
and the frontal component were significantly associated with intelligence. The parietal and frontal
regions were each distinctively associated with intelligence by maintaining structural networks with
the cerebellum and the temporal region, respectively. The cerebellar component was associated
with visuomotor ability. Our results support the parieto-frontal integration theory of intelligence by
demonstrating how each core region for intelligence works in concert with other regions. In addition,
we revealed how the cerebellum is associated with intelligence and cognitive functions
Prevalence and risk factors of postpartum depression, general depressive symptoms, anxiety and stress (PODSAS) among mothers during their 4-week postnatal follow-up in five public health clinics in Perak: a study protocol for a cross-sectional study
Introduction Postpartum depression, general depressive symptoms, anxiety and stress (PODSAS) are often overlooked, and may cause morbidity to new mothers, their babies and families. This study aims to determine the point prevalence of depression (post partum and general), anxiety and stress among mothers in five public health clinics in Perak at 4 weeks postdelivery and identify their associated risk factors. Findings from this study will be used to identify the needs for early screening and detection, encourage development of interventions to reduce its occurrence and support mothers with PODSAS. Methods and analysis This cross-sectional study will recruit 459 postpartum mothers during their 4-week postnatal follow-up in five selected public health clinics in Perak from September 2019 to May 2020. Participants will be mothers aged 18 years and above at 4 weeks postdelivery who are able to understand the English and Malay languages. Non-Malaysians and mothers with known diagnosis of psychotic disorders will be excluded from the study. Sociodemographic information and possible risk factors of the participants will be captured via a set of validated questionnaires, postpartum depression (PPD) will be measured using the Edinburgh Postpartum Depression Scale questionnaire and general depressive symptoms, anxiety and stress will be measured using the 21-item Depression, Anxiety and Stress Scale. Data analysis will be conducted using SPSS V.25.0 (IBM). Besides descriptive statistics, multivariable regression analyses will be done to identify possible risk factors and their independent associations with depression (PPD and general depressive symptoms, combined and separately), anxiety and stress
Long-term outcomes of liver transplant recipients followed up in non-transplant centres: care closer to home
Introduction: Increasing rates of liver transplantation and improved outcomes have led to greater numbers of transplant recipients followed up in non-transplant centres. Our aim was to document long-term clinical outcomes of liver transplant recipients managed in this ‘hub and spoke’ healthcare model.Methods: A retrospective analysis of all adult patients who underwent liver transplantation between 1987 and 2016, with post-transplant follow-up in two non-transplant centres in the UK (Nottingham) and Canada (Ottawa) was performed.Results: The 1-, 5-, 10- and 20-year patient survival rates were 98%, 95%, 87% and 62%, and 100%, 96%, 88% and 62% in the Nottingham and Ottawa groups, respectively (p=0.87). There were no significant differences between the two centres in 1-, 5-, 10- and 20-year cumulative incidence of death-censored graft-survival (p=0.10), end-stage renal disease (p=0.29) or de novo cancer (p=0.22). Nottingham had a lower incidence of major cardiovascular events (p=0.008).Conclusion: Adopting a new model of healthcare provides a means of delivering post-transplant patient care close to home, without compromising patient survival and long-term clinical outcomes
Diagnostic accuracy of non-invasive tests for advanced fibrosis in patients with NAFLD: An individual patient data meta-analysis
Objective Liver biopsy is still needed for fibrosis staging in many patients with non-alcoholic fatty liver disease. The aims of this study were to evaluate the individual diagnostic performance of liver stiffness measurement by vibration controlled transient elastography (LSM-VCTE), Fibrosis-4 Index (FIB-4) and NAFLD (non-alcoholic fatty liver disease) Fibrosis Score (NFS) and to derive diagnostic strategies that could reduce the need for liver biopsies. Design Individual patient data meta-analysis of studies evaluating LSM-VCTE against liver histology was conducted. FIB-4 and NFS were computed where possible. Sensitivity, specificity and area under the receiver operating curve (AUROC) were calculated. Biomarkers were assessed individually and in sequential combinations. Results Data were included from 37 primary studies (n=5735; 45% women; median age: 54 years; median body mass index: 30 kg/m2; 33% had type 2 diabetes; 30% had advanced fibrosis). AUROCs of individual LSM-VCTE, FIB-4 and NFS for advanced fibrosis were 0.85, 0.76 and 0.73. Sequential combination of FIB-4 cut-offs (<1.3; ≥2.67) followed by LSM-VCTE cut-offs (<8.0; ≥10.0 kPa) to rule-in or rule-out advanced fibrosis had sensitivity and specificity (95% CI) of 66% (63-68) and 86% (84-87) with 33% needing a biopsy to establish a final diagnosis. FIB-4 cut-offs (<1.3; ≥3.48) followed by LSM cut-offs (<8.0; ≥20.0 kPa) to rule out advanced fibrosis or rule in cirrhosis had a sensitivity of 38% (37-39) and specificity of 90% (89-91) with 19% needing biopsy. Conclusion Sequential combinations of markers with a lower cut-off to rule-out advanced fibrosis and a higher cut-off to rule-in cirrhosis can reduce the need for liver biopsies
Performance of non-invasive tests and histology for the prediction of clinical outcomes in patients with non-alcoholic fatty liver disease: an individual participant data meta-analysis
Background: Histologically assessed liver fibrosis stage has prognostic significance in patients with non-alcoholic fatty liver disease (NAFLD) and is accepted as a surrogate endpoint in clinical trials for non-cirrhotic NAFLD. Our aim was to compare the prognostic performance of non-invasive tests with liver histology in patients with NAFLD. Methods: This was an individual participant data meta-analysis of the prognostic performance of histologically assessed fibrosis stage (F0–4), liver stiffness measured by vibration-controlled transient elastography (LSM-VCTE), fibrosis-4 index (FIB-4), and NAFLD fibrosis score (NFS) in patients with NAFLD. The literature was searched for a previously published systematic review on the diagnostic accuracy of imaging and simple non-invasive tests and updated to Jan 12, 2022 for this study. Studies were identified through PubMed/MEDLINE, EMBASE, and CENTRAL, and authors were contacted for individual participant data, including outcome data, with a minimum of 12 months of follow-up. The primary outcome was a composite endpoint of all-cause mortality, hepatocellular carcinoma, liver transplantation, or cirrhosis complications (ie, ascites, variceal bleeding, hepatic encephalopathy, or progression to a MELD score ≥15). We calculated aggregated survival curves for trichotomised groups and compared them using stratified log-rank tests (histology: F0–2 vs F3 vs F4; LSM: <10 vs 10 to <20 vs ≥20 kPa; FIB-4: <1·3 vs 1·3 to ≤2·67 vs >2·67; NFS: <–1·455 vs –1·455 to ≤0·676 vs >0·676), calculated areas under the time-dependent receiver operating characteristic curves (tAUC), and performed Cox proportional-hazards regression to adjust for confounding. This study was registered with PROSPERO, CRD42022312226. Findings: Of 65 eligible studies, we included data on 2518 patients with biopsy-proven NAFLD from 25 studies (1126 [44·7%] were female, median age was 54 years [IQR 44–63), and 1161 [46·1%] had type 2 diabetes). After a median follow-up of 57 months [IQR 33–91], the composite endpoint was observed in 145 (5·8%) patients. Stratified log-rank tests showed significant differences between the trichotomised patient groups (p<0·0001 for all comparisons). The tAUC at 5 years were 0·72 (95% CI 0·62–0·81) for histology, 0·76 (0·70–0·83) for LSM-VCTE, 0·74 (0·64–0·82) for FIB-4, and 0·70 (0·63–0·80) for NFS. All index tests were significant predictors of the primary outcome after adjustment for confounders in the Cox regression. Interpretation: Simple non-invasive tests performed as well as histologically assessed fibrosis in predicting clinical outcomes in patients with NAFLD and could be considered as alternatives to liver biopsy in some cases. Funding: Innovative Medicines Initiative 2 (*The LITMUS investigators
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