Finite element modelling strategy for determining directivity of thermoelastically generated laser ultrasound

Laser ultrasound (LU) is a contactless and couplant-free remote non-destructive (NDE) technique, which uses lasers for ultrasonic generation and detection rather than conventional piezoelectric transducers. For a transducer, an important characteristic is the directivity, the angle-dependent amplitude of the ultrasonic waves generated in the material. In the non-destructive thermoelastic regime, LU source has been widely modelled as a surface force dipole. However, the directivity of LU in more complex material, where there is an increasing demand for NDE, such as carbon fibre reinforced plastic (CFRP), is yet to be understood. In the current paper, a finite element (FE) modelling methodology to obtain the directivity of LU in complex material is presented. The method is applied to a conductive isotropic material (aluminium, Al) for validation against an existing analytical solution and then applied to a heterogeneous anisotropic material (carbon-fibre reinforced plastic, CFRP). To get the directivity of a specific wave mode, the signal for that mode needs to be resolved in time from other modes at all angles. This is challenging for shear (S) waves in a small model domain due to the head wave, so a technique for suppressing the head wave is shown. The multi-physics model solves for thermal expansion, which models the laser source as a surface heat flux for the Al case, and a buried heat source for the CFRP case, according to where the energy is deposited in the material. The same ultrasound generation pattern can be obtained by using a suitable pure elastodynamic loading, which is shown to be a surface force dipole as per the validation case for Al, and a buried quadrupole for the CFRP case. The modelled directivities are scaled and fitted to experimental measurements using maximum likelihood, and the goodness of fit is discussed. For the Al case, the S wave is preferred over the longitudinal (L) wave for inspection due to greater signal amplitude. For the CFRP case, the quasi-longitudinal (qL) wave in CFRP shows a maximum amplitude directly below the source, and has a greater amplitude than the quasi-shear (qS) wave, suggesting a better choice for inspection

Sex differences in clinical outcomes amongst 1,105 patients admitted with hip fractures

Amongst hip fracture admissions, mortality is higher in men than in women. However, sex differences in other care-quality measures have not been well-documented. We aimed to examine sex differences in mortality as well as a wide range of underlying health indicators and clinical outcomes in adults ≥ 60 year of age admitted with hip fractures from their own homes to a single NHS hospital between April-2009 and June-2019. Sex differences in delirium, length of stay (LOS) and mortality in hospital, readmission, and discharge destination, were examined by logistic regression. There were 787 women and 318 men of similar mean age (± SD): 83.1 year (± 8.6) and 82.5 year (± 9.0), respectively (P = 0.269). There were no sex differences in history of dementia or diabetes, anticholinergic burden, pre-fracture physical function, American Society of Anesthesiologists grades, or surgical and medical management. Stroke and ischaemic heart disease, polypharmacy, and alcohol consumption were more common in men. After adjustment for these differences and age, men had greater risk of delirium (with or without cognitive impairment) within one day of surgery: OR = 1.75 (95%CI 1.14–2.68), LOS ≥ 3 weeks in hospital: OR = 1.52 (1.07–2.16), mortality in hospital: OR = 2.04 (1.14–3.64), and readmission once or more after 30 days of a discharge: OR = 1.53 (1.03–2.31). Men had a lower risk of a new discharge to residential/nursing care: OR = 0.46 (0.23–0.93). The present study revealed that, in addition to a greater risk of mortality than women, men also had many other adverse health outcomes. These findings, which have not been well-documented, serve to stimulate future targeted preventive strategies and research

Associations of CTCF and FOXA1 with androgen and IGF pathways in men with localized prostate cancer

AimsTo examine associations between the transcription factors CCCTC-binding factor (CTCF) and forkhead box protein A1 (FOXA1) and the androgen receptor (AR) and their association with components of the insulin-like growth factor (IGF)-pathway in a cohort of men with localized prostate cancer.MethodsUsing prostate tissue samples collected during the Prostate cancer: Evidence of Exercise and Nutrition Trial (PrEvENT) trial (N = 70 to 92, depending on section availability), we assessed the abundance of CTCF, FOXA1, AR, IGFIR, p-mTOR, PTEN and IGFBP-2 proteins using a modified version of the Allred scoring system. Validation studies were performed using large, publicly available datasets (TCGA) (N = 489).ResultsWe identified a strong correlation between CTCF and AR staining with benign prostate tissue. CTCF also strongly associated with the IGFsingle bondIR, with PTEN and with phospho-mTOR. FOXA1 was also correlated with staining for the IGF-IR, with IGFBP-2 and with staining for activated phosphor-mTOR. The staining for the IGF-IR was strongly correlated with the AR.ConclusionOur findings emphasise the close and complex links between the endocrine controls, well known to play an important role in prostate cancer, and the transcription factors implicated by the recent genetic evidence

Diamond chemical vapor deposition using a zero-total gas flow environment

We demonstrate diamond growth through microwave plasma-enhanced chemical vapor deposition using a sealed (static-mode) CH4/H2 process gas mixture. The growth experiments were complemented by spatially and spectrally resolved optical emission imaging measurements of electronically excited C2 and CH radicals in the hot plasma core. The as-grown material was characterized by Raman Spectroscopy and Scanning Electron Microscopy and shown to be typical of polycrystalline diamond grown using traditional methods. Moreover, this material was essentially indistinguishable from material grown using a tracked flow-mode of operation in which the input methane flow rate was progressively reduced to mimic the time evolving C2 emission intensities in the static-mode experiments. These proving static-mode studies demonstrate a ~30-fold improvement (cf. that achieved using standard flow-mode conditions) in the conversion efficiency of carbon in the input source gas into diamond, and we argue that further gains should be possible with appropriate reactor and process optimization. Static-flow growth could be particularly advantageous in the case of depositions using limited, expensive, hazardous, or environmentally damaging feedstock gases