Phase relations,and mechanical and electronic properties of nickel borides,carbides, and nitrides from ab initio calculations

Based on density functional theory and the crystal structure prediction methods, USPEX and AIRSS, stable intermediate compounds in the Ni–X (X = B, C, and N) systems and their structures were determined in the pressure range of 0–400 GPa. It was found that in the Ni–B system, in addition to the known ambient-pressure phases, the new nickel boride, Ni₂B₃-Immm, stabilizes above 202 GPa. In the Ni–C system, Ni₃C-Pnma was shown to be the only stable nickel carbide which stabilizes above 53 GPa. In the Ni–N system, four new phases, Ni₆N-R$\bar{3}$, Ni₃N-Cmcm, Ni₇N₃-Pbca, and NiN₂-Pa$\bar{3}$, were predicted. For the new predicted phases enriched by a light-element, Ni₂B₃-Immm and NiN₂-Pa$\bar{3}$, mechanical and electronic properties have been studied.

Based on density functional theory and the crystal structure prediction methods, USPEX and AIRSS, stable intermediate compounds in the Ni–X (X = B, C, and N) systems and their structures were determined in the pressure range of 0–400 GPa.     

Efficacy of interspace between the popliteal artery and the capsule of the posterior knee (iPACK) block versus periarticular local infiltration analgesia after unilateral total knee arthroplasty: Prospective randomized control trial

Objectives:To compare the efficacy of interspace between the popliteal artery and the capsule of the posterior knee (iPACK) block with periarticular local infiltration analgesia (LIA) to assess postoperative pain control and enhanced recovery after total knee arthroplasty (TKA).Methods:This research was carried out at King Saud University Medical City, Riyadh, Saudi Arabia, from September 2020 to March 2021. Eighty Patients scheduled for elective unilateral TKA were randomized to receive either iPACK or periarticular LIA along with adductor canal block under spinal anesthesia. The primary outcome was postoperative pain score, and secondary outcomes included physical rehabilitation, duration of surgery, length of post-anesthesia care unit stay, hemodynamics, and length of hospital stay.Results:The pain score during activity in iPACK group was significantly lower compared to LIA group at 4 hours postoperatively, but no significant difference was observed at 24 or 48 hours. The timed up and go test took significantly longer for patients in LIA group at 4, 24, and 48 hours compared to those in iPACK group. No significant differences in knee range of motion were observed between the 2 groups at any point.Conclusion:Based on our findings, iPACK block is an effective technique in reducing pain in the immediate postoperative period without affecting motor function, resulting in enhanced recovery following primary TKA.     

Mechanical Experiments on Concrete with Hybrid Fiber Reinforcement for Structural Rehabilitation

Reinforced concrete is used in the construction of bridges, buildings, retaining walls, roads, and other engineered structures. Due to seismic activities, a lot of structures develop seismic cracks. The rehabilitation of such structures is necessary for public safety. The overall aim of this research study was to produce a high-performance hybrid fiber-reinforced concrete (HPHFRC) with enhanced properties as compared to plain high-performance concrete and high-performance fiber-reinforced concrete (HPFRC) for the rehabilitation of bridges and buildings. Kevlar fibers (KF) and glass fibers (GF) with lengths of 35 mm and 25 mm, respectively, were added and hybridized to 1.5% by mass of cement to create hybrid fiber-reinforced concrete mixes. Eight mixes were cast in total. The compressive strength (f′_c), flexural strength (f_r), splitting tensile strength (f_s), and other mechanical properties, i.e., energy absorption and toughness index values, were enhanced in HPHFRC as compared to CM and HPFRC. It was found that the concrete hybridized with 0.75% KF and 0.75% GF (HF-G 0.75 K 0.75) had the most enhanced overall mechanical properties, illustrating its potential to be utilized in the rehabilitation of bridges and structures.     

BAG3 mutations: another cause of giant axonal neuropathy

Mutations in Bcl-2 associated athanogene-3 (BAG3) are a rare cause of myofibrillar myopathy, characterised by rapidly progressive proximal and axial myopathy, cardiomyopathy and respiratory compromise. Neuropathy has been documented neurophysiologically in previously reported cases of BAG3-associated myofibrillar myopathy and in some cases giant axons were observed on nerve biopsies; however, neuropathy was not thought to be a dominant feature of the disease. In the context of inherited neuropathy, giant axons are typically associated with autosomal recessive giant axonal neuropathy caused by gigaxonin mutations but have also been reported in association with NEFL- and SH3TC2-associated Charcot-Marie-Tooth disease. Here, we describe four patients with heterozygous BAG3 mutations with clinical evidence of a sensorimotor neuropathy, with predominantly axonal features on neurophysiology. Three patients presented with a significant neuropathy. Muscle magnetic resonance imaging (MRI) in one patient revealed mild to moderate atrophy without prominent selectivity. Examination of sural nerve biopsies in two patients demonstrated giant axons. This report confirms the association of giant axonal neuropathy with BAG3-associated myofibrillar myopathy, and highlights that neuropathy may be a significant feature.     

Comparison of fluorescein and phycoerythrin conjugates for quantifying CD20 expression on normal and leukemic B-cells

BACKGROUND: Numerous methods for quantitative fluorescence calibration (QFC) have been developed to quantify receptor expression on lymphocytes as potential disease biomarkers. CD20 expression in B-cell chronic lymphocytic leukemia (B-CLL) is one of the best examples of such a biomarker, but results from the use of different QFC methods vary considerably. METHODS: We measured CD20 expression on normal and B-CLL B-cells, using FITC and PE conjugates from the same monoclonal antibody (Mab). As a biological control and calibrator, we also measured CD4 expression on T-cells with FITC and PE Mab. Calibration curves were constructed using the CLSI (formerly NCCLS) consensus guidelines for QFC. Calibration with QuantiBRITE PE-labeled microspheres and the use of unimolar PE conjugates provided direct measurement of antibody bound per cell (ABC) for CD4 and CD20. Calibration for FITC conjugates was based on molecules of equivalent soluble fluorochrome (MESF), as determined by NIST RM 8640 microsphere standards. These MESF values were then converted to ABC, using the CD4 T-cell as a biologic calibrator, to normalize FITC and PE results for CD20 expression. RESULTS: On normal B cells, the mean ABC value for unimolar CD20-PE conjugate was 143,500 (CV +/- 19.1%). The mean ABC value for B-CLL B-cells stained with the same conjugate was 21,700 (CV +/- 42.0%). Using the CD4 T-cell as a biologic calibrator for FITC conjugate, the mean ABC value for CD20-FITC on normal B-cells was 199,300. CD20-FITC staining on B-CLL cells was generally too weak for accurate quantification. On normal T-cells, the mean ABC value for CD4 unimolar PE conjugate was (36,800 +/- 10.4)%, and it did not differ significantly in CLL samples. CONCLUSION: The expression of CD20 on normal and B-CLL lymphocytes can be quantified in ABC units using unimolar CD20-PE conjugates. In addition, CD4 expression on T-cells can be used as a biological calibrator to quantify CD20-FITC ABC, with reasonable agreement between the two conjugates with different fluorochromes. Issues regarding the accuracy of MESF microsphere calibrators and effective F/P ratios for FITC conjugates will require additional laboratory studies.     

Evolution of migraine after a 10-year follow-up

OBJECTIVE: To assess the evolution of headaches in a workplace cohort over a 10-year period. BACKGROUND: Migraine headaches are associated with significant handicap in everyday activities and poor quality of life. The prevalence of migraine shows a bell-shaped age distribution with a peak during the third and fourth decades. However, there is little longitudinal data available on the natural history of this condition. A prospective health survey undertaken in a large workplace cohort since 1989 provides an opportunity to assess the evolution of migraine and other headache syndromes over a 10-year period. METHODS: A sample of 2500 subjects who reported regular headaches was chosen at random from those with headache identified in a cohort of 46,244 employees of the French national power company aged between 35 and 50 years in 1989 participating in a yearly health survey. In 1993, all subjects were sent a headache questionnaire to complete and return. In 2003, an identical questionnaire was sent to all subjects who had returned exploitable data in 1993. Headache diagnosis was assigned retrospectively using the International Headache Society (IHS) criteria to migraine (IHS categories 1.1 and 1.2), migrainous disorder (IHS category 1.7), or other episodic headaches. RESULTS: Of 2500 subjects sampled, 2051 (82%) returned exploitable data for the first questionnaire in 1993. In 2003, 1250 (61%) of these provided a second data set. In 1993, 623 (30.4%) of subjects fulfilled diagnostic criteria for migraine. However, only 37% of these retained the diagnosis 10 years later. In contrast, the proportion of subjects with other forms of episodic headache rose from 23.7% to 31.6%. In 2003, 9.5% of the sample were headache-free. Retention or acquisition of a diagnosis of migraine was more common in women than in men, and age was associated with evolution to a less severe headache syndrome. In those subjects who continued to have headaches, frequency and severity were lower at the second assessment. CONCLUSIONS: Only a minority of subjects diagnosed with migraine or migrainous disorder retain the diagnosis 10 years later, with most subjects evolving to a less disabling headache type.