393 research outputs found

    Laser drilling of microholes in single crystal silicon using continuous wave (CW) 1070 nm fiber lasers with millisecond pulse widths

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    The laser microdrilling of via holes in Si semiconductor wafers was studied using 1 ms pulses from an Yb fibre laser with 1070 nm wavelength. Optical microscopy and cross‑sectional analysis were used to quantify hole dimensions, the distribution of recast material and any microcracking for both (100) and (111) single crystal surface semiconductor wafer orientations. The flexibility of this laser wavelength and simple pulsing scheme were demonstrated for a range of semiconductor substrates of narrow and wide bandgap including InSb, GaSb, InAs, GaAs, InP and sapphire. Detailed observations for Si showed that, between the threshold energies for surface melting and the irradiance for drilling a “thru” hole from the front surface to rear surface, there was a range of irradiances for which microcracking occurred near the hole circumference. The directionality and lengths of these microcracks were studied for the (100) and (111) orientations and possible mechanisms for formation were discussed, including the Griffith criterion for microcracks and the failure mechanism of fatigue usually applied to welding of metals. Above the irradiance for formation of a thru hole, few cracks were observed. Future work will compare similar observations and measurements in other narrow- and wide-bandgap semiconductor wafer substrates

    Medical cannabis, CBD wellness products and public awareness of evolving regulations in the United Kingdom

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    Background: In the UK, legislation and regulations governing medical cannabis and over the counter cannabidiol (CBD) wellness products have rapidly evolved since 2018. This study aimed to assess the public awareness of the availability, regulations, and barriers to access medical cannabis and over the counter CBD wellness products. Methods: A cross-sectional survey study was performed through YouGov® using quota sampling methodology between March 22nd and March 31st 2021. Responses were matched and statistically weighted to UK adult population demographics, including those without internet access, and analysed according to percentage of respondents. Statistical significance was defined by p-value < 0.050. Results: Ten thousand six hundred eighty-four participants completed the survey. 5,494 (51.4%) respondents believed that medical cannabis is legal in the UK. 684 (6.4%) participants consumed CBD for wellness reasons, 286 (2.7%) were prescribed CBD for a medical reason and 222 (2.1%) consumed CBD for another reason. 10,076 (94.3%) respondents were unaware of April 2021 regulations meaning that all over the counter CBD wellness products in the UK must conform to European Novel Foods Regulations. The most frequently reported main barriers to accessing medical cannabis were its association with recreational cannabis (n = 2,686; 25.1%), being unsure if it was legal (n = 2,276; 21.3%) and being unsure what medical conditions its can be used for (n = 1,863; 17.4%). Conclusion: A large proportion of respondents are unaware of the legislation and regulations surrounding medical cannabis and over the counter CBD wellness products. Lack of knowledge may present a barrier to safe access to either product

    Clinical outcome data of children treated with cannabis-based medicinal products for treatment resistant epilepsy - analysis from the UK medical cannabis registry.

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    BACKGROUND:  There is a paucity of high-quality evidence of the efficacy and safety of cannabis-based medicinal products in treatment of treatment-resistant epilepsy (TRE) in children. METHODS:  A case series of children (<18 years old) with TRE from the UK Medical Cannabis Registry was analyzed. Primary outcomes were ≥50% reduction in seizure frequency, changes in the Impact of Pediatric Epilepsy Score (IPES), and incidence of adverse events. RESULTS:  Thirty-five patients were included in the analysis. Patients were prescribed during their treatment with the following: CBD isolate oils (n = 19), CBD broad-spectrum oils (n = 17), and CBD/Δ9-THC combination therapy (n = 17). Twenty-three (65.7%) patients achieved a ≥50% reduction in seizure frequency. 94.1% (n = 16) of patients treated with CBD and Δ9-THC observed a ≥50% reduction in seizure frequency compared to 31.6% (n = 6) and 17.6% (n = 3) of patients treated with CBD isolates and broad-spectrum CBD products, respectively (p< 0.001). Twenty-six (74.3%) adverse events were reported by 16 patients (45.7%). The majority of these were mild (n = 12; 34.2%) and moderate (n = 10; 28.6%). CONCLUSION:  The results of this study demonstrate a positive signal of improved seizure frequency in children treated with Cannabis-based medicinal products (CBMPs) for TRE. Moreover, the results suggest that CBMPs are well-tolerated in the short term. The limitations mean causation cannot be determined in this open-label, case series

    An observational study of safety and clinical outcome measures across patient groups in the United Kingdom Medical Cannabis Registry.

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    BACKGROUND: There is a paucity of high-quality data on patient outcomes and safety after initiating treatment with cannabis-based medicinal products (CBMPs). The aim of this study was to assess the clinical outcomes and safety of CBMPs by analyzing patient-reported outcome measures and adverse events across a broad spectrum of chronic conditions. RESEARCH DESIGN AND METHODS: This study analyzed patients enrolled in the UK Medical Cannabis Registry. Participants completed the EQ-5D-5L to assess health-related quality of life, Generalized Anxiety Disorder-7 (GAD-7) questionnaire to measure anxiety severity, and the Single-item Sleep Quality Scale (SQS) to rate sleep quality at baseline and follow-up after 1, 3, 6, and 12 months. RESULTS: A total of 2833 participants met inclusion criteria. The EQ-5D-5L index value, GAD-7, and SQS all improved at each follow-up (p  0.050). Adverse events were reported by 474 (16.73%) participants. CONCLUSIONS: This study suggests that CBMPs are associated with an improvement in health-related quality of life in UK patients with chronic diseases. Treatment was tolerated well by most participants, but adverse events were more common in female and cannabis-naïve patients

    Comparing the effects of medical cannabis for chronic pain patients with and without co-morbid anxiety: A cohort study.

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    INTRODUCTION: There is growing evidence on the efficacy of cannabis-based medicinal products (CBMPs) for chronic pain (CP). Due to the interaction between CP and anxiety, and the potential impact of CBMPs on both anxiety and CP, this article aimed to compare the outcomes of CP patients with and without co-morbid anxiety following CBMP treatment. METHODS: Participants were prospectively enrolled and categorized by baseline General Anxiety Disorder-7(GAD-7) scores, into 'no anxiety'(GAD-7  0.050). The anxiety cohort reported greater improvements in EQ-5D-5L index values, SQS and GAD-7(p < 0.050), but there were no consistent differences in pain outcomes. CONCLUSION: A potential association between CBMPs and improvements in pain and health-related quality of life (HRQoL) in CP patients was identified. Those with co-morbid anxiety reported greater improvements in HRQoL

    Laser drilling of microholes in single crystal silicon using continuous wave (CW) 1070 nm fiber lasers with millisecond pulse widths

    Get PDF
    The laser microdrilling of via holes in Si semiconductor wafers was studied using 1 ms pulses from an Yb fibre laser with 1070 nm wavelength. Optical microscopy and cross‑sectional analysis were used to quantify hole dimensions, the distribution of recast material and any microcracking for both (100) and (111) single crystal surface semiconductor wafer orientations. The flexibility of this laser wavelength and simple pulsing scheme were demonstrated for a range of semiconductor substrates of narrow and wide bandgap including InSb, GaSb, InAs, GaAs, InP and sapphire. Detailed observations for Si showed that, between the threshold energies for surface melting and the irradiance for drilling a “thru” hole from the front surface to rear surface, there was a range of irradiances for which microcracking occurred near the hole circumference. The directionality and lengths of these microcracks were studied for the (100) and (111) orientations and possible mechanisms for formation were discussed, including the Griffith criterion for microcracks and the failure mechanism of fatigue usually applied to welding of metals. Above the irradiance for formation of a thru hole, few cracks were observed. Future work will compare similar observations and measurements in other narrow- and wide-bandgap semiconductor wafer substrates

    The Moral Economy of Heroin in ‘Austerity Britain’

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    This article presents the findings of an ethnographic exploration of heroin use in a disadvantaged area of the United Kingdom. Drawing on developments in continental philosophy as well as debates around the nature of social exclusion in the late-modern west, the core claim made here is that the cultural systems of exchange and mutual support which have come to underpin heroin use in this locale—that, taken together, form a ‘moral economy of heroin’—need to be understood as an exercise in reconstituting a meaningful social realm by, and specifically for, this highly marginalised group. The implications of this claim are discussed as they pertain to the fields of drug policy, addiction treatment, and critical criminological understandings of disenfranchised groups

    The epidemiology of reoperations for orthopaedic trauma.

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    Introduction: The Royal College of Surgeons of England (RCS) has issued guidance regarding the use of reoperation rates in the revalidation of UK-based orthopaedic surgeons. Currently, little has been published concerning acceptable rates of reoperation following primary surgical management of orthopaedic trauma, particularly with reference to revalidation. / Methods: A retrospective review was conducted of patients undergoing clearly defined reoperations following primary surgical management of trauma between 1 January 2010 and 31 December 2011. A full case note review was undertaken to establish the demographics, clinical course and context of reoperation. A review of the imaging was performed to establish whether the procedure performed was in line with accepted trauma practice and whether the technical execution was acceptable. / Results: A total of 3,688 patients underwent primary procedures within the time period studied while 70 (1.90%, 99% CI: 1.39–2.55) required an unplanned reoperation. Thirty-nine (56%) of these patients were male. The mean age of patients was 56 years (range: 18–98 years) and there was a median time to reoperation of 50 days (IQR: 13–154 days). Potentially avoidable reoperations occurred in 41 patients (58.6%, 99% CI: 43.2–72.6). This was largely due to technical errors (40 patients, 57.1%, 99% CI: 41.8–71.3), representing 1.11% (99% CI: 0.73–1.64) of the total trauma workload. Within RCS guidelines, 28-day reoperation rates for hip, wrist and ankle fractures were 1.4% (99% CI: 0.5–3.3), 3.5% (99% CI: 0.8%–12.1) and 1.86% (99% CI: 0.4–6.6) respectively. / Conclusions: We present novel work that has established baseline reoperation rates for index procedures required for revalidation of orthopaedic surgeons
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