Streptomyces antioxidans sp. nov., a Novel Mangrove Soil Actinobacterium with Antioxidative and Neuroprotective Potentials

A novel strain, Streptomyces antioxidans MUSC 164(T) was recovered from mangrove forest soil located at Tanjung Lumpur, Malaysia. The Gram-positive bacterium forms yellowish-white aerial and brilliant greenish yellow substrate mycelium on ISP 2 agar. A polyphasic approach was used to determine the taxonomy status of strain MUSC 164(T). The strain showed a spectrum of phylogenetic and chemotaxonomic properties consistent with those of the members of the genus Streptomyces. The cell wall peptidoglycan was determined to contain LL-diaminopimelic acid. The predominant menaquinones were identified as MK-9(H(6)) and MK-9(H(8)), while the identified polar lipids consisted of aminolipid, diphosphatidylglycerol, glycolipid, hydroxyphosphatidylethanolamine, phospholipid, phosphatidylinositol, phosphatidylethanolamine, phosphatidylglycerol and lipid. The cell wall sugars consist of galactose, glucose and ribose. The predominant cellular fatty acids (>10.0%) were identified as iso-C(15:)(0) (34.8%) and anteiso-C(15:)(0)(14.0%). Phylogenetic analysis identified that closely related strains for MUSC 164(T) as Streptomyces javensis NBRC 100777(T) (99.6% sequence similarity), Streptomyces yogyakartensis NBRC 100779(T) (99.6%) and Streptomyces violaceusniger NBRC 13459(T) (99.6%). The DNA–DNA relatedness values between MUSC 164(T) and closely related type strains ranged from 23.8 ± 0.3% to 53.1 ± 4.3%. BOX-PCR fingerprints comparison showed that MUSC 164(T) exhibits a unique DNA profile, with DNA G + C content determined to be 71.6 mol%. Based on the polyphasic study of MUSC 164(T), it is concluded that this strain represents a novel species, for which the name Streptomyces antioxidans sp. nov. is proposed. The type strain is MUSC 164(T) (=DSM 101523(T) = MCCC 1K01590(T)). The extract of MUSC 164(T) showed potent antioxidative and neuroprotective activities against hydrogen peroxide. The chemical analysis of the extract revealed that the strain produces pyrazines and phenolic-related compounds that could explain for the observed bioactivities

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

Background: The EMPA KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population. Methods: EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110. Findings: Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5–2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62–0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16–1·59), representing a 50% (42–58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1). Interpretation: In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease. Funding: Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council

Behaviour of concrete confined by circular and elliptical hoops inder axial loads

The thesis is about the investigation of the behaviour of concrete confined by lateral reinforcement. Experimental program for the testing of the confined concrete using circular spirals and elliptical hoops is described. Those specimens with circular spirals were tested under monotonic and cyclic axial loads whereas those with elliptical hoops were tested under monotonic axial load only.Doctor of Philosophy (CSE

Behaviour of reinforced concrete columns strengthened by external means

179 p.A literature review of different techniques of strengthening and repair of concrete columns was carried out. In this project, sixteen columns were tested to investigate the strengthening of columns using external straps. The straps were made from steel channels and the columns were subjected to only axial loads. It was found that such technique of laterally confining the column produced almost no significant change in initial axial stiffness. The strength of the concrete was increased but only marginally.DRF 1A/9

Behaviour of concrete under triaxial stress

This research is to study the triaxial behaviour of concrete under monotonic and cyclic loading. To understand the role of cement mortar in the mechanical behaviour of concrete, triaxial behaviour of cement mortar was included.RG 13/9

Material and structural behaviour of steel and concrete structures at elevated temperatures

A programme of experimental testing has been conducted to investigate the behaviour of steel columns and concrete-encased steel section composite columns at elevated temperature. Heating is attained in an electric furnace. Measurements of internal forces, lateral deflections, axial displacements and temperatures are reported. Twenty steel column specimens were subjected to elevated temperatures. One loading test was carried out at ambient temperature to determine the working load to be applied to the other specimens in the same series for elevated temperature tests. The variable parameters were slenderness ratio and axial restraint ratio. The experimental measurements are presented and compared with predictions from numerical simulations using FEMFAN-3D, a program developed by NTU. It is concluded that buckling temperature decreases as slenderness ratio increases, under a fixed restraint ratio. Applying increased axial restraint to the columns has a negative effect of reducing the buckling temperatures. Eleven composite column tests were conducted under elevated temperature conditions. The composite columns were categorised into three series with different variable parameters, namely overall cross-sectional size, load ratio and axial restraint ratio. Results show that the fire resistance of composite column improves with an increase in overall cross–sectional size. An increase in load ratio or axial restraint ratio will lead to a reduction in its fire resistance. Test results are compared with FEMFAN-3D predictions for verifying the accuracy of the program. Column behaviour under elevated temperatures and predictions and limitations of the numerical program FEMFAN are discussed in the report.RG 7/0

Design considerations and guidelines in the use of Grade 600 steel reinforcements for reinforced concrete construction

There is growing interest within the construction industry in using Grade 600 reinforcing steel for certain applications. There are areas where Grade 600 steel reinforcement can help include improvement in construction efficiencies and reduction in manpower. However, the implementation of these Grade 600 reinforcements in designs and construction still pose some challenges, as a number of unresolved design issues still remain. Notably current EC 2 design provisions do not provide explicit guidelines on the use of these high strength steel reinforcements and may not have addressed some distinctive performance characteristics. This paper lists potential issues with the use of Grade 600 reinforcement, and also provides a comprehensive assessment of available literature on the impact of Grade 600 steel reinforcement on design practices.Published versio