Towards Understanding Astrophysical Effects of Nuclear Symmetry Energy

Determining the Equation of State (EOS) of dense neutron-rich nuclear matter is a shared goal of both nuclear physics and astrophysics. Except possible phase transitions, the density dependence of nuclear symmetry \esym is the most uncertain part of the EOS of neutron-rich nucleonic matter especially at supra-saturation densities. Much progresses have been made in recent years in predicting the symmetry energy and understanding why it is still very uncertain using various microscopic nuclear many-body theories and phenomenological models. Simultaneously, significant progresses have also been made in probing the symmetry energy in both terrestrial nuclear laboratories and astrophysical observatories. In light of the GW170817 event as well as ongoing or planned nuclear experiments and astrophysical observations probing the EOS of dense neutron-rich matter, we review recent progresses and identify new challenges to the best knowledge we have on several selected topics critical for understanding astrophysical effects of the nuclear symmetry energy.Comment: 77 pages. Invited Review Article, EPJA (2019) in pres

The Content Analysis of English Textbooks Based on Alan Cunningsworth’s Criteria: A Systematic Review

This investigation endeavors to elucidate the merits and demerits inherent in English textbooks as delineated in a myriad of scholarly articles dedicated to the content analysis of pedagogical materials for English instruction. A plethora of English textbooks, disseminated by governmental or non-governmental publishers, underwent scrutiny through the prism of various theoretical frameworks, most notably Alan Cunningsworth's discerning criteria. Employing a systematic review, this research meticulously unveils the commendable aspects and deficiencies encapsulated within the fabric of English textbooks or coursebooks expounded upon in the surveyed articles. A compendium of fifteen articles, spanning the temporal expanse from 2015 to 2023, was subjected to rigorous analysis through the discerning lens of Alan Cunningsworth's evaluative criteria. The discerning scrutiny revealed that all the scrutinized English textbooks impeccably adhered to and fulfilled the exacting standards posited by Cunningsworth's criteria. However, interspersed within these articles lay instances where certain textbooks failed to meet the stringent criteria delineated by Alan Cunningsworth. This investigation aspires to transcend its immediate findings, serving as a beacon of reference for future researchers and English educators engaged in the analytical or evaluative scrutiny of English instructional material

Effect of chemical–electrochemical surface treatment on the roughness and fatigue performance of porous titanium lattice structures

Additive manufacturing (AM) has enabled the fabrication of extremely complex components such as porous metallic lattices, which have applications in aerospace, automotive, and in particular biomedical devices. The fatigue resistance of these materials is currently an important limitation however, due to manufacturing defects such as semi-fused particles and weld lines. In this work a chemical–electrochemical surface treatment (Hirtisation®) is used for post-processing of Ti-6Al-4V lattices, reducing the strut surface roughness (Sa) from 12 to 6 μm, removing all visible semi-fused particles. The evenness of this treatment in lattices with relative density up to 18.3% and treatment depth of 6.5 mm was assessed, finding no evidence of reduced effectiveness on internal surfaces. After normalising to quasi-static mechanical properties to account for material losses during hirtisation (34%–37% reduction in strut diameter), the fatigue properties show a marked improvement due to the reduction in surface roughness. Normalised high cycle fatigue strength increased from around 0.1 to 0.16-0.21 after hirtisation, an average increase of 80%. For orthopaedic implant devices where matching the stiffness of surrounding bone is crucial, the fatigue strength to modulus ratio is a key metric. After hirtisation the fatigue strength to modulus ratio increased by 90%, enabling design of stiffness matched implant materials with greater fatigue strength. This work demonstrates that hirtisation is an effective method for improving the surface roughness of porous lattice materials, thereby enhancing their fatigue performance

Characterisation of Bacterial Isolates from Patients Wounds and Environmental Factors Predictive of Post-Surgical Infections at the Orthopaedic Ward in Ile-Ife, Nigeria

Objective: To determine the pattern of orthopaedic wound infection and the influence of environmental factors on the distribution of the etiologic bacterial agents. Design: A prospective observational study. Setting: Department of Orthopaedic Surgery and Traumatology, Obafemi Awolowo University Teaching Hospitals Complex, Ile-Ife, Nigeria. Subjects: Sixty patients with orthopaedic wound infections and orthopaedic ward environment. Results: Thirty- nine males (mean age 33.31+2SD) and 21 females ( mean age 27.47+2SD) with orthopaedic wounds. Three hundred and ten bacteria (190 from patients and 120 from ward environment) were isolated. The pattern of bacterial isolates from patients’ wounds was different from that of the airborne bacterial isolates irrespective of the length of stay on the ward. There was a significant difference in the distribution and resistance pattern of bacterial isolates from the patient’s wounds and ward environment. Conclusion: There is a high incidence of antibiotic resistance of bacterial isolates from samples cultured from patients compared with isolates from ward environment at this centre. The extensive use of pre-operative prophylactic and post-surgical antibiotics in various combinations at this centre needs to be re-examined to reduce the preponderance of antibiotic resistance

Effect of chemical–electrochemical surface treatment on the roughness and fatigue performance of porous titanium lattice structures

Additive manufacturing (AM) has enabled the fabrication of extremely complex components such as porous metallic lattices, which have applications in aerospace, automotive, and in particular biomedical devices. The fatigue resistance of these materials is currently an important limitation however, due to manufacturing defects such as semi-fused particles and weld lines. In this work a chemical–electrochemical surface treatment (Hirtisation®) is used for post-processing of Ti-6Al-4V lattices, reducing the strut surface roughness (Sa) from 12 to 6 μm, removing all visible semi-fused particles. The evenness of this treatment in lattices with relative density up to 18.3% and treatment depth of 6.5 mm was assessed, finding no evidence of reduced effectiveness on internal surfaces. After normalising to quasi-static mechanical properties to account for material losses during hirtisation (34%–37% reduction in strut diameter), the fatigue properties show a marked improvement due to the reduction in surface roughness. Normalised high cycle fatigue strength increased from around 0.1 to 0.16-0.21 after hirtisation, an average increase of 80%. For orthopaedic implant devices where matching the stiffness of surrounding bone is crucial, the fatigue strength to modulus ratio is a key metric. After hirtisation the fatigue strength to modulus ratio increased by 90%, enabling design of stiffness matched implant materials with greater fatigue strength. This work demonstrates that hirtisation is an effective method for improving the surface roughness of porous lattice materials, thereby enhancing their fatigue performance

Clinical Effectiveness, Access to, and Satisfaction with Care Using a Telehomecare Substitution Intervention: A Randomized Controlled Trial

Background. Hospitalization accounts for 70% of heart failure (HF) costs; readmission rates at 30 days are 24% and rise to 50% by 90 days. Agencies anticipate that telehomecare will provide the close monitoring necessary to prevent HF readmissions. Methods and Results. Randomized controlled trial to compare a telehomecare intervention for patients 55 and older following hospital discharge for HF to usual skilled home care. Primary endpoints were 30- and 60-day all-cause and HF readmission, hospital days, and time to readmission or death. Secondary outcomes were access to care, emergency department (ED) use, and satisfaction with care. All-cause readmissions at 30 days (16% versus 19%) and over six months (46% versus 52%) were lower in the telehomecare group but were not statistically significant. Access to care and satisfaction were significantly higher for the telehomecare patients, including the number of in-person visits and days in home care. Conclusions. Patient acceptance of the technology and current home care policies and processes of care were barriers to gaining clinical effectiveness and efficiency

Formal properties of recursive Virtual Machine architectures.

A formal model of hardware/software architectures is developed and applied to Virtual Machine Systems. Results are derived on the sufficient conditions that a machine architecture must verify in order to support VM systems. The model deals explicitly with resource mappings (protection) and with I/O devices. Some already published results are retrieved and other ones, more general, are obtained

Muscle injury and impaired function, and insulin resistance in Chromogranin A knockout mice

Chromogranin A (CgA) is widely expressed in endocrine and neuroendocrine tissues as well as in the central nervous system. We observed CgA expression (mRNA and protein) in the gastrocnemius (GAS) muscle and found that performance of CgA-deficient Chga-KO mice in treadmill exercise was impaired. Supplementation with CgA in Chga-KO mice restored exercise ability suggesting a novel role for endogenous CgA in skeletal muscle function. Chga-KO mice display (i) lack of exercise-induced stimulation of pAKT, pTBC1D1 and phospho-p38 kinase signaling, (ii) loss of GAS muscle mass, (iii) extensive formation of tubular aggregates (TA), (iv) disorganized cristae architecture in mitochondria, (v) increased expression of the inflammatory cytokines Tnfα, Il6 and Ifnɣ, and fibrosis. The impaired maximum running speed and endurance in the treadmill exercise in Chga-KO mice correlated with decreased glucose uptake and glycolysis, defects in glucose oxidation and decreased mitochondrial cytochrome C oxidase activity. The lack of adaptation to endurance training correlated with the lack of stimulation of p38MAPK that is known to mediate the response to tissue damage. Since CgA sorts proteins to the regulated secretory pathway, we speculate that lack of CgA could cause misfolding of membrane proteins inducing aggregation of sarcoplasmic reticulum (SR) membranes and formation of tubular aggregates that is observed in Chga-KO mice. In conclusion, CgA deficiency renders the muscle energy deficient, impairs performance in treadmill exercise and prevents regeneration after exercise-induced tissue damage