Drill Tools for Earth and space design of a novel longitudinal-torsional ultrasonic transducer

Measurement of complex combinations of different vibration modes operating together at ultrasonic frequencies can be carried out using 3-D laser vibrometry

A generalised approach to torsionality maximisation in longitudinal-torsional ultrasonic devices

A longitudinal-torsional vibration mode has many applications in ultrasonic systems. Obtaining this behaviour could be achieved either by coupling the longitudinal and torsional modes or by degenerating the longitudinal mode, but the results may be unsatisfactory. These methods have many disadvantages including the expense and complexity in operation, the possibility of coupling unwanted bending modes, and the low responsiveness and torsionality. In this work, we employed a geometric modification to a traditional Langevin transducer to overcome these disadvantages. This was achieved by incorporating helical slits and exponential geometry features in the front mass of the transducer. Finite element analysis and vibration response measurements show that this strategy prevents coupling of bending modes, increases responsiveness, reduces energy losses, and produces high torsionality

Optimisation of the longitudinal-torsional output of a half-wavelength Langevin transducer

Numerous ultrasonic applications, such as high-frequency/low frequency drilling, require or can benefit from the inclusion of some torsional vibration behaviour within a primarily longitudinal pattern. Producing longitudinal-torsional (LT) vibration in a Langevin transducer using the mode degeneration method tends to give more robust results than the competing mode-coupling approach, and this work is concerned with optimizing the relative strengths of the longitudinal and torsional responses within the context of a half-wavelength Langevin transducer. Using numerical and experimental techniques, the output of such a system is predicted across a range of geometries and compared to experimental results obtained through laser vibrometry

Does cardiac rehabilitation favour the young over the old?

BACKGROUND: Although cardiac rehabilitation (CR) is a proven intervention in reducing cardiovascular mortality and morbidity there is concern that CR programme delivery may not yield comparable outcomes across age groups. PURPOSE: This study sought to determine if the outcomes achieved after completing CR were influenced by age in patients with coronary heart disease. METHOD: Patients were stratified into 2 age groups: young (18-65 years) and elderly (>65 years). Pre-CR and post-CR assessments were used to compute changes in 9 CR outcomes (body mass index (BMI), waist size, hyperlipidaemia, hypertension, smoking, walking fitness, physical activity, anxiety and depression). Pearson's χ(2) test was used to examine the association between the age groups and outcome. Data was extracted from the UK National Audit from July 2010 to June 2015. RESULTS: A total of 203 012 young patients (55.1±7.9 years, 78% male) and 262 813 elderly patients (76.1±6.9 years, 63.9% male) were analysed. Young patients had a better ratio of improvement across a wide range of risk factors in particular smoking cessation (OR=3.3, p<0.001) while elderly patients had a better ratio of improvement in body shape risk factors BMI (OR=1.3, p<0.001), waist size in women (OR=1.3, p=0.016). CONCLUSIONS: Age is significant predictor of outcomes following CR. While elderly patients achieve better outcomes in body shape risk factors, younger patients clearly achieve better outcomes across a wider range of risk factors in particular smoking cessation

Sc0.43(2)Rb2Mo15S19, a partially Sc-filled variant of Rb2Mo15S19

International audienceThe structure of scandium dirubidium pentadecamolybdenum nonadecasulfide, Sc0.43 (2)Rb2Mo15S19, constitutes a partially Sc-filled variant of Rb2Mo15S19 [Picard, Saillard, Gougeon, Noel & Potel (2000), J. Solid State Chem.155, 417426]. In the two compounds, which both crystallize in the Rc space group, the structural motif is characterized by a mixture of Mo6Si8Sa6 and Mo9Si11Sa6 cluster units ('i' is inner and 'a' is apical) in a 1:1 ratio. The two components are interconnected through interunit MoS bonds. The cluster units are centred at Wyckoff positions 6b and 6a (point-group symmetries and 32, respectively). The Rb+ cations occupy large voids between the different cluster units. The Rb and the two inner S atoms lie on sites with 3. symmetry (Wyckoff site 12c), and the Mo and S atoms of the median plane of the Mo9S11S6 cluster unit lie on sites with .2 symmetry (Wyckoff site 18e). A unique feature of the structure is a partially filled octahedral Sc site with symmetry. Extended Huckel tight-binding calculations provide an understanding of the variation in the MoMo distances within the Mo clusters induced by the increase in the cationic charge transfer due to the insertion of Sc

HTLV-1 Tax-1 interacts with SNX27 to regulate cellular localization of the HTLV-1 receptor molecule, GLUT1

An estimated 10–20 million people worldwide are infected with human T cell leukemia virus type 1 (HTLV-1), with endemic areas of infection in Japan, Australia, the Caribbean, and Africa. HTLV-1 is the causative agent of adult T cell leukemia (ATL) and HTLV-1 associated myopathy/tropic spastic paraparesis (HAM/TSP). HTLV-1 expresses several regulatory and accessory genes that function at different stages of the virus life cycle. The regulatory gene Tax-1 is required for efficient virus replication, as it drives transcription of viral gene products, and has also been demonstrated to play a key role in the pathogenesis of the virus. Several studies have identified a PDZ binding motif (PBM) at the carboxyl terminus of Tax-1 and demonstrated the importance of this domain for HTLV-1 induced cellular transformation. Using a mass spectrometry-based proteomics approach we identified sorting nexin 27 (SNX27) as a novel interacting partner of Tax-1. Further, we demonstrated that their interaction is mediated by the Tax-1 PBM and SNX27 PDZ domains. SNX27 has been shown to promote the plasma membrane localization of glucose transport 1 (GLUT1), one of the receptor molecules of the HTLV-1 virus, and the receptor molecule required for HTLV-1 fusion and entry. We postulated that Tax-1 alters GLUT1 localization via its interaction with SNX27. We demonstrate that over expression of Tax-1 in cells causes a reduction of GLUT1 on the plasma membrane. Furthermore, we show that knockdown of SNX27 results in increased virion release and decreased HTLV-1 infectivity. Collectively, we demonstrate the first known mechanism by which HTLV-1 regulates a receptor molecule post-infection.</div

Synthesis of a Spirocyclic Oxetane-Fused Benzimidazole

A new synthesis of 2-oxa-7-azaspiro[3.5]nonane is described. Spirocyclic oxetanes, including 2-oxa-6-azaspiro[3.3]heptane were converted into o-cycloalkylaminoacetanilides for oxidative cyclizations using Oxone((R)) in formic acid. The expanded spirocyclic oxetane successfully gave the [1,2-a] ring-fused benzimidazole. X-ray crystal structure of the resultant new tetracyclic system, 1',2'-dihydro-4'H-spiro[oxetane-3,3'-pyrido[1,2-a]benzimidazole] and the azetidine ring-opened adduct, N-(2-acetamido-4-bromophenyl)-N-{[3-(chloromethyl)oxetan-3-yl]methyl}acetamide are disclosed