105 research outputs found

    Use of BI-Pb-Sn-Cd Alloy in Self-neutralisation Mechanism for Sub-munitions

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    Unexploded sub munitions for military operations posed economic loss and health hazard. The need for unexploded sub munitons to be rendered safe after a certain period of time was of importance to the militaty. In this work, a self-neutralizing sub-component using soft metal penetration principle was developed and incorporated to the existing sub munitions so as to include a self-neutralizing feature in such sub munitions. This study was also conducted to determine the potential to use a steel wire to cut BI-Pb-Sn-Cd alloy at different temperatures (-40 °C~40 °C). The effect of temperature on neutralisation time was evaluated in experiments. The experimental results indicated that the neutralisation time was dependent on temperature of soft metal and decreased with increasing temperature. While BI-Pb-Sn-Cd alloy with thickness of 0.75±0.01 mm and height of 2.40 ±0.02 mm was cut by steel wire with a diameter of 0.12 mm, self-neutrlisation of sub munitions was completed ranging from 1min5s to 143 h 2 min. It was concluded that self-neutralisation based on BI-Pb-Sn-Cd alloy could meet its setting requirements in the battlefield, and its failure rate reached less than 10% at between -40 °C and 40 °C, and the self-neutralisation time could be adjusted by the size of soft metal

    Thickness dependence of superconductivity and superconductor-insulator transition in ultrathin FeSe films on SrTiO3(001) substrate

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    Interface-enhanced high-temperature superconductivity in one unit-cell (UC) FeSe film on SrTiO3(001) (STO) substrate has recently attracted much attention in condensed matter physics and material science. Here, by ex situ transport measurements, we report on the superconductivity in FeSe ultra-thin films with different thickness on STO substrate. We find that the onset superconducting transition temperature (Tc) decreases with increasing film thickness of FeSe, which is opposite to the behavior usually observed in traditional superconductor films. By systematic post-annealing of 5 UC FeSe films, we observe an insulator to superconductor transition, which is accompanied with a sign change of the dominated charge carriers from holes to electrons at low temperatures according to the corresponding Hall measurement

    Characterization and genome analysis of Neobacillus mesonae NS-6, a ureolysis-driven strain inducing calcium carbonate precipitation

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    In this study, a highly promising bacterium was isolated from sandstone oil in the Ordos Basin, named strain NS-6 which exhibited exceptional urease production ability and demonstrated superior efficiency in inducing the deposition of calcium carbonate (CaCO3). Through morphological and physiochemical characteristics analysis, as well as 16S rRNA sequencing, strain NS-6 was identified as Neobacillus mesonae. The activity of urease and the formation of CaCO3 increased over time, reaching a maximum of 7.9 mmol/L/min and 184 mg (4.60 mg/mL) respectively at 32 h of incubation. Scanning Electron Microscopy (SEM) revealed CaCO3 crystals ranging in size from 5 to 6 μm, and Energy Dispersive X-ray (EDX) analysis verified the presence of calcium, carbon, and oxygen within the crystals. X-ray Diffraction (XRD) analysis further confirmed the composition of these CaCO3 crystals as calcite and vaterite. Furthermore, the maximum deposition of CaCO3 by strain NS-6 was achieved using response surface methodology (RSM), amounting to 193.8 mg (4.845 mg/mL) when the concentration of calcium ions was 0.5 mmol/L supplemented with 0.9 mmol/L of urea at pH 8.0. Genome-wide analysis revealed that strain NS-6 possesses a chromosome of 5,736,360 base pairs, containing 5,442 predicted genes, including 3,966 predicted functional genes and 1,476 functionally unknown genes. Genes like ureA, ureB, and ureC related to urea catabolism were identified by gene annotation, indicating that strain NS-6 is a typical urease-producing bacterium and possesses a serial of genes involved in metabolic pathways that mediated the deposition of CaCO3 at genetic level

    Spin Fluctuation Induced Linear Magnetoresistance in Ultrathin Superconducting FeSe Films

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    The discovery of high-temperature superconductivity in FeSe/STO has trigged great research interest to reveal a range of exotic physical phenomena in this novel material. Here we present a temperature dependent magnetotransport measurement for ultrathin FeSe/STO films with different thickness and protection layers. Remarkably, a surprising linear magnetoresistance (LMR) is observed around the superconducting transition temperatures but absent otherwise. The experimental LMR can be reproduced by magnetotransport calculations based on a model of magnetic field dependent disorder induced by spin fluctuation. Thus, the observed LMR in coexistence with superconductivity provides the first magnetotransport signature for spin fluctuation around the superconducting transition region in ultrathin FeSe/STO films

    Facilitators of HCV treatment adherence among people who inject drugs: a systematic qualitative review and implications for scale up of direct acting antivirals

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    Abstract Background While the public health benefits of new HCV treatments depend on treatment adherence, particularly among people who inject drugs (PWID), several social and medical factors can jeopardize treatment adherence. The aim of this study is to examine the qualitative literature on facilitators to HCV treatment adherence among PWID. Methods We searched six databases to identify qualitative research studies on HCV treatment adherence facilitators among PWID. Two reviewers independently extracted and analyzed data using PRISMA guidelines and the CASP tool to evaluate study quality. Results From ten studies representing data from 525 participants, three major themes emerged across studies: logistical facilitators within health systems enhanced HCV treatment adherence, positive social interactions between PWID and staff provided positive feedback during treatment, and HCV treatment may complicate the addiction recovery process. Conclusions Although PWID face several barriers to adherence, we identified treatment adherence facilitators that could be incorporated into clinical practice

    The Role of ARV Associated Adverse Drug Reactions in Influencing Adherence Among HIV-Infected Individuals: A Systematic Review and Qualitative Meta-Synthesis

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    Poor adherence remains a major barrier to achieving the clinical and public health benefits of antiretroviral drugs (ARVs). A systematic review and qualitative meta-synthesis was conduct to evaluate how ARV adverse drug reactions may influence ARV adherence. Thirty-nine articles were identified, and 33 reported that ARV adverse drug reactions decreased adherence and six studies found no influence. Visually noticeable adverse drug reactions and psychological adverse reactions were reported as more likely to cause non-adherence compared to other adverse drug reactions. Six studies reported a range of adverse reactions associated with EFV-containing regimens contributing to decreased adherence. Informing HIV-infected individuals about ARV adverse drug reactions prior to initiation, counselling about coping mechanisms, and experiencing the effectiveness of ARVs on wellbeing may improve ARV adherence

    Exploring the Social Meaning of Curing HIV: A Qualitative Study of People Who Inject Drugs in Guangzhou, China

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    Our objective was to explore the social meaning of HIV and perceptions of an HIV cure among people who inject drugs (PWID) in Guangzhou, China, which speaks to ethical and resource challenges to development in this field. We conducted a qualitative research study using in-depth interviews. We analyzed interview transcripts from 29 PWID, eight physicians, and three social workers from an outpatient HIV clinic and two methadone maintenance treatment centers. The social meaning of HIV infection and perceptions of an HIV cure reflected patients' relationships with society, health systems, and physicians. First, HIV infection decreased perceived social worth and disrupted peer relationships. The possibility of being cured renewed patient hope for regaining physical well-being and achieving social mobility. However, the existence of a cure may not alter the HIV-related stigma due to its association with stigmatized behaviors and marginalized groups. Second, although stigma was a significant barrier to engagement in health care, hope for a cure may outweigh fears of stigma and enhance linkage to HIV testing and treatment as well as methadone services. A cure may exacerbate perceived health disparities if inaccessible to key affected populations such as PWID. The social implications of an HIV cure among this key affected population may inform the design and implementation of cure clinical trials. Careful management of patient expectations, focusing research on key affected populations, expanding HIV testing and treatment systems, improving access to harm reduction programs, and ensuring post-trial access are important considerations for HIV cure research

    Facilitators and barriers in HIV linkage to care interventions: a qualitative evidence review

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    To synthesize qualitative evidence on linkage to care interventions for people living with HIV

    Barriers and facilitators of interventions for improving antiretroviral therapy adherence: a systematic review of global qualitative evidence.

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    INTRODUCTION: Qualitative research on antiretroviral therapy (ART) adherence interventions can provide a deeper understanding of intervention facilitators and barriers. This systematic review aims to synthesize qualitative evidence of interventions for improving ART adherence and to inform patient-centred policymaking. METHODS: We searched 19 databases to identify studies presenting primary qualitative data on the experiences, attitudes and acceptability of interventions to improve ART adherence among PLHIV and treatment providers. We used thematic synthesis to synthesize qualitative evidence and the CERQual (Confidence in the Evidence from Reviews of Qualitative Research) approach to assess the confidence of review findings. RESULTS: Of 2982 references identified, a total of 31 studies from 17 countries were included. Twelve studies were conducted in high-income countries, 13 in middle-income countries and six in low-income countries. Study populations focused on adults living with HIV (21 studies, n=1025), children living with HIV (two studies, n=46), adolescents living with HIV (four studies, n=70) and pregnant women living with HIV (one study, n=79). Twenty-three studies examined PLHIV perspectives and 13 studies examined healthcare provider perspectives. We identified six themes related to types of interventions, including task shifting, education, mobile phone text messaging, directly observed therapy, medical professional outreach and complex interventions. We also identified five cross-cutting themes, including strengthening social relationships, ensuring confidentiality, empowerment of PLHIV, compensation and integrating religious beliefs into interventions. Our qualitative evidence suggests that strengthening PLHIV social relationships, PLHIV empowerment and developing culturally appropriate interventions may facilitate adherence interventions. Our study indicates that potential barriers are inadequate training and compensation for lay health workers and inadvertent disclosure of serostatus by participating in the intervention. CONCLUSIONS: Our study evaluated adherence interventions based on qualitative data from PLHIV and health providers. The study underlines the importance of incorporating social and cultural factors into the design and implementation of interventions. Further qualitative research is needed to evaluate ART adherence interventions
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