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1.
Curr Diab Rep ; 24(4): 61-73, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38294726

RESUMO

PURPOSE OF REVIEW: Maintaining positive health behaviours promotes better health outcomes for people with type 1 diabetes (T1D). However, implementing these behaviours may also lead to additional management burdens and challenges. Diabetes technologies, including continuous glucose monitoring systems, automated insulin delivery systems, and digital platforms, are being rapidly developed and widely used to reduce these burdens. Our aim was to review recent evidence to explore the influence of these technologies on health behaviours and well-being among adults with T1D and discuss future directions. RECENT FINDINGS: Current evidence, albeit limited, suggests that technologies applied in diabetes self-management education and support (DSME/S), nutrition, physical activity (PA), and psychosocial care areas improved glucose outcomes. They may also increase flexibility in insulin adjustment and eating behaviours, reduce carb counting burden, increase confidence in PA, and reduce mental burden. Technologies have the potential to promote health behaviours changes and well-being for people with T1D. More confirmative studies on their effectiveness and safety are needed to ensure optimal integration in standard care practices.


Assuntos
Diabetes Mellitus Tipo 1 , Adulto , Humanos , Diabetes Mellitus Tipo 1/terapia , Diabetes Mellitus Tipo 1/psicologia , Automonitorização da Glicemia , Promoção da Saúde , Glicemia , Insulina , Comportamentos Relacionados com a Saúde , Tecnologia
2.
Surg Endosc ; 38(7): 3849-3857, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38831212

RESUMO

BACKGROUND AND STUDY AIMS: Endoscopic ultrasound-guided gastrojejunostomy (EUS-GJ) has been well utilized in treating malignant gastric outlet obstructions (GOO) given its efficacy and lower risk profile compared to surgery. However, its efficacy and potential for use in patients with benign GOO who are poor surgical candidates is not well documented. The aim of this study was to examine the role of EUS-GJ in treatment of benign GOO in select patients. PATIENTS AND METHODS: This is a single-center, open-label, retrospective descriptive study that included all consecutive patients undergoing EUS-GJ to treat benign causes of GOO. Direct antegrade and direct retrograde methods were utilized. RESULTS: A total of 18 patients were included, 38.9% female with an average age of 63.3 years. Extrinsic GOO was present in (10 of 18) 55.5% of patients and intrinsic etiology was present in (8 of 18) 45.5% of patients. Technical success was achieved in 100% (18 of 18) patients and clinical success was achieved in 94% (17 of 18) patients. In total, 13 patients had follow-up endoscopy, 2 patients were treated relatively recently in time, 1 patient was lost to follow-up, and 2 patients died of other chronic illnesses. Stents remained in place for a median of 286 days (range 88-1444 days). In patients whose stents were removed, 75% (3 of 4) had extrinsic etiologies of GOO. CONCLUSIONS: This study reports a favorable long-term patency with excellent technical and clinical success of EUS-GJ in patients with benign GOO. Despite the limitations of sample size and retrospective nature, it adds to the extremely limited literature of EUS-GJ in management of patients with benign GOO.


Assuntos
Endossonografia , Derivação Gástrica , Obstrução da Saída Gástrica , Ultrassonografia de Intervenção , Humanos , Obstrução da Saída Gástrica/cirurgia , Obstrução da Saída Gástrica/etiologia , Feminino , Estudos Retrospectivos , Pessoa de Meia-Idade , Masculino , Derivação Gástrica/métodos , Endossonografia/métodos , Idoso , Resultado do Tratamento , Ultrassonografia de Intervenção/métodos , Adulto , Idoso de 80 Anos ou mais
3.
J Environ Manage ; 352: 120054, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38211432

RESUMO

Adoption of edge-of-field conservation practices, such as denitrifying bioreactors, may be intrinsically linked to barriers associated with cost. However, most previous bioreactor cost efficiency assessments assumed values for either costs and/or nitrate removal. The objective of this work was to use actual construction costs as well as monitored nitrate removal to develop empirical cost efficiencies for eight full-size bioreactors in Illinois, USA. Capital construction costs were obtained via invoices or personal communications. A cash-flow discounting procedure was used to develop an equal annualized cost for each bioreactor assuming two media recharges over a 24-y planning horizon. These costs were combined with monitored nitrate removal based on one to six years of monitoring per site. Construction costs averaged $12,250 ± $7520 across the eight sites (or, $16,020 ± $9960 in 2023 price levels) but considering one of the sites was a paired bioreactor system, costs averaged $10,890 per bioreactor unit. Drainage treatment area-based cost averaged $132/ha-y and treatment area was strongly correlated with capital costs (R2 = 0.90; p = 0.001). The bioreactors averaged $108/m3 of woodchips and available federal government conservation programs could have offset an average of 70% of this cost. Monitored nitrate removal across 27 site-years resulted in a median of $33/kg N-y removed. This mass-based cost efficiency was higher than most previous assessments because the monitored nitrate removal for the study sites was lower than has been previously assumed or modeled. Future reporting about bioreactor recharge timing and cost will help guide assessment and planning. Water quality planning efforts should also consider the increasingly important engineering design costs, which were not included here. Suggested research and outreach to improve bioreactor cost efficiencies involves scaling the physical capacity of this technology for larger treatment areas, revisiting the use of low-cost non-standard fill media, and providing practical construction training.


Assuntos
Desnitrificação , Nitratos , Reatores Biológicos , Illinois
4.
Catheter Cardiovasc Interv ; 98(1): 128-136, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-33909945

RESUMO

BACKGROUND: Covered stent correction of sinus venosus ASDs (SVASD) is a relatively new technique. Challenges include anchoring a sufficiently long stent in a nonstenotic superior vena cava (SVC) and expanding the stent at the wider SVC-RA junction without obstructing the anomalous right upper pulmonary vein (RUPV). The 10-zig covered Cheatham-platinum (CCP) stent has the advantage of being available in lengths of 5-11 cm and dilatable to 34 mm in diameter. METHODS: An international registry reviewed the outcomes of 10-zig CCP stents in 75 patients aged 11.4-75.9 years (median 45.4) from March 2016. Additional stents were used to anchor the stent in the SVC or close residual shunts in 33/75. An additional stent was placed in 4/5 (80%) with 5/5.5 cm CCPs, 18/29 (62%) with 6 cm CCPs, 5/18 (28%) with 7 cm CCPs, 5/22 (23%) with 7.5/8 cm CCPs and 0/1 with an 11 cm CCP. A "protective" balloon catheter was inflated in the RUPV in 17. RESULTS: Early stent embolization in two patients required surgical removal and defect repair and tamponade was drained in one patient. The CT at 3 months showed occlusion of the RUPV in one patient. Follow up is from 2 months to 5.1 years (median 1.8 years). QP:QS has reduced from 2.5 ± 0.5 to 1.2 ± 0.36 (p < .001) and RVEDVi from 149.1 ± 35.4 to 95.6 ± 21.43 ml/m2 (p < .001). CONCLUSIONS: Ten-zig CCPs of 7-8 cm appear to provide reliable SVASD closure with a low requirement for additional stents. Careful selection of patients and meticulous attention to detail is required to avoid complications.


Assuntos
Comunicação Interatrial , Platina , Humanos , Sistema de Registros , Stents , Resultado do Tratamento , Veia Cava Superior
5.
Osteoporos Int ; 31(7): 1305-1314, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32080756

RESUMO

Mobile fracture prevention services, with DXA, significantly improved access to care for those at high risk of fracture living in rural areas. Introduction of mobile services facilitated access to fracture liaison services and development of integrated of care pathways across community- and secondary-based care. INTRODUCTION: The ageing population is growing faster in rural areas, yet most fracture prevention services are located in urban areas. As part of a wider study, evaluating the introduction of mobile fracture prevention services, we focus on whether mobile services improve access to care for those at highest risk of fracture. METHODS: Services outcomes were assessed against the Royal Osteoporosis Society clinical standards for fracture liaison services. This included standardised, age-specific referral rates, FRAX 10-year probability of major osteoporotic and hip fracture of referrals, pre- and post-introduction of the mobile service across two island and one rural mainland sites. This was compared with referrals from a similar rural mainland region with local access to a comprehensive service. RESULTS: Greatest impact occurred in areas with most limited service provision at baseline. Mean age of patients referred increased from 59 to 68 years (CI 6.8-10.1, p < 0.001). Referral rates increased from 2.8 to 5.4 per 1000 population between 2011 and 2018, with a 5-fold rise in those ≥ 75 years (0.4 to 2.0 per 1000). Mean FRAX 10-year risk of major osteoporotic fracture increased from 12.7 to 17.7% (CI 3.2-5.7, p < 0.001). Mean hip fracture risk probability increased from 3.0 to 5.7% (CI 2.0-3.4, p < 0.001). However, referral rates from the mobile sites remained lower than the comparator site. CONCLUSIONS: Mobile fracture prevention services, including DXA, greatly improved uptake amongst high-risk individuals. Mobile services facilitated development of integrated of care pathways, including fracture liaison services, across community- and secondary-based care.


Assuntos
Fraturas do Quadril , Osteoporose , Fraturas por Osteoporose , Idoso , Fraturas do Quadril/diagnóstico por imagem , Fraturas do Quadril/epidemiologia , Fraturas do Quadril/prevenção & controle , Humanos , Pessoa de Meia-Idade , Osteoporose/complicações , Osteoporose/epidemiologia , Fraturas por Osteoporose/epidemiologia , Fraturas por Osteoporose/prevenção & controle , População Rural , Escócia/epidemiologia , Prevenção Secundária
6.
Anaesthesia ; 75(11): 1509-1516, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32369611

RESUMO

Intra-operative aerosol-generating procedures are arguably unavoidable in the routine provision of thoracic anaesthesia. Airway management for such patients during the COVID-19 pandemic including tracheal intubation, lung isolation, one-lung ventilation and flexible bronchoscopy may pose a significant risk to healthcare professionals and patients. That said, there remains a need for timely thoracic surgery for patients with lung cancer or thoracic trauma. The thoracic anaesthetic community has been confronted with the need to modify existing techniques to maximise safety for patients and healthcare professionals. With appropriate modification, aerosol generation may be mitigated against in most circumstances. We developed a set of practice-based recommendations for airway management in thoracic surgical patients, which have been endorsed by the Association for Cardiothoracic Anaesthesia and Critical Care and the Society for Cardiothoracic Surgery in Great Britain and Ireland.


Assuntos
Manuseio das Vias Aéreas/métodos , Betacoronavirus , Infecções por Coronavirus/epidemiologia , Ventilação Monopulmonar/métodos , Pneumonia Viral/epidemiologia , Procedimentos Cirúrgicos Torácicos/métodos , Extubação , Anestesia em Procedimentos Cardíacos , Broncoscopia , COVID-19 , Pressão Positiva Contínua nas Vias Aéreas , Cuidados Críticos , Humanos , Intubação Intratraqueal , Pandemias , SARS-CoV-2 , Sociedades Médicas
7.
J Cardiovasc Nurs ; 35(6): E33-E43, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32453276

RESUMO

BACKGROUND: Adults with congenital heart disease (CHD) are an emerging adult heart disease subset, now outnumbering the pediatric population with CHD. OBJECTIVE: We aimed to gain understanding and knowledge of what adults with CHD perceive as important for self-management and describe these needs across demographic factors, developmental characteristics, lesion severity, and quality of life. METHODS: We used a descriptive mixed-methods online survey merging 4 instruments: Adult CHD Self-management Experience Questionnaire; Adult CHD Demographic Questionnaire; Adaptive Behavior Assessment System, Third Edition; and Stanford Quality of Life Visual Numeric. Participants with CHD 18 to 30 years of age with initial defect repair before 12 months of age were recruited through support from the Adult Congenital Heart Association, clinic adult CHD support groups, and newspaper advertising. Thematic analysis for short-answer questions, descriptive analysis for demographic data and the visual numeric, and intrument-specific scoring assistant software for the Adaptive Behavior Assessment System were used. RESULTS: We received 22 responses from 13 women and 9 men. These individuals represented 15 different heart defect diagnoses, mostly of moderate or complex lesion severity. Most had postsecondary education and were employed. Four prominent themes emerged related to self-management: desire for connectivity-psychological support; a plan for the future-education about health and life expectations; coping needs-skills for mental stress; and access to care-navigation of healthcare systems. CONCLUSIONS: Future longitudinal research and replication studies with larger samples are needed. Educational materials and targeted interventions that promote self-management benefit the aging adult with CHD population.


Assuntos
Necessidades e Demandas de Serviços de Saúde , Cardiopatias Congênitas/psicologia , Cardiopatias Congênitas/terapia , Autogestão/psicologia , Adaptação Psicológica , Adulto , Feminino , Comportamentos Relacionados com a Saúde , Conhecimentos, Atitudes e Prática em Saúde , Cardiopatias Congênitas/epidemiologia , Humanos , Masculino , Qualidade de Vida , Fatores Socioeconômicos , Inquéritos e Questionários , Adulto Jovem
8.
HIV Med ; 20(8): 523-533, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31124278

RESUMO

OBJECTIVES: In the UK, men who have sex with men (MSM) bear a disproportionate sexually transmitted infection (STI) burden. We investigated MSM's STI knowledge; whether their STI testing behaviour met national guidelines (annually if sexually active; 3-monthly if engaging in STI risk behaviours); and the relationship between STI testing in the last 3 months, STI knowledge and STI risk behaviours by HIV status. METHODS: Sexually active (in the last year) men aged > 15 years who were UK residents and were recruited from gay-orientated online dating platforms completed an anonymous online survey about STI knowledge, STI risk behaviours, and STI testing (March-May 2017). This included 11 true statements about STIs. Respondents scored 1 for each statement they 'knew', with those scoring < 6 overall treated as having 'poor' STI knowledge. Descriptive and multivariable analyses were conducted, separately by HIV status, to test our hypothesis and calculate adjusted odds ratios (AORs) with 95% confidence intervals (CIs). RESULTS: Compared to HIV-positive men (n = 489), the proportion of HIV-negative/unknown-status men (n = 3157) with 'poor' STI knowledge was significantly higher (46.4% versus 22.9% for HIV-positive men) and the proportion with STI testing in the last 12 months was lower (71.6% versus 87.2%, respectively). In the last 3 months, 56.9% of HIV-negative/unknown-status and 74.1% of HIV-positive men reported STI risk behaviours, of whom 45.8% and 55.1%, respectively, had been tested for STIs during this time. Among HIV-negative/unknown-status men, those reporting STI risk behaviours were more likely (AOR 1.52; 95% CI 1.26-1.84) and those with poor STI knowledge less likely (AOR 0.73; 95% CI 0.61-0.89) to have been tested during the last 3 months. However, neither factor was independently associated with 3-monthly testing among HIV-positive men. CONCLUSIONS: Improving STI knowledge, especially among HIV-negative/unknown-status men, and promoting frequent STI testing among men engaging in STI risk behaviours are vital to address the poor sexual health of MSM.


Assuntos
Infecções por HIV/epidemiologia , Programas de Rastreamento/métodos , Infecções Sexualmente Transmissíveis/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Conhecimentos, Atitudes e Prática em Saúde , Homossexualidade Masculina , Humanos , Internet , Masculino , Pessoa de Meia-Idade , Assunção de Riscos , Autorrelato , Reino Unido/epidemiologia , Adulto Jovem
13.
J Biopharm Stat ; 29(2): 348-358, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30352015

RESUMO

The relative potency of one agent to another is commonly represented by the ratio of two quantal response parameters; for example, the LD50 of animals receiving a treatment to the LD50 of control animals, where LD50 is the dose of toxin that is lethal to 50% of animals. Though others have considered interval estimators of LD50, here, we extend Bayesian, bootstrap, likelihood ratio, Fieller's and Wald's methods to estimate intervals for relative potency in a parallel-line assay context. In addition to comparing their coverage probabilities, we also consider their power in two types of dose designs: one assigning treatment and control the same doses vs. one choosing doses for treatment and control to achieve same lethality targets. We explore these methods in realistic contexts of relative potency of radiation countermeasures. For larger experiments (e.g., ≥100 animals), the methods return similar results regardless of the interval estimation method or experiment design. For smaller experiments (e.g., < 60 animals), Wald's method stands out among the others, producing intervals that hold closely to nominal levels and providing more power than the other methods in statistically efficient designs. Using this simple statistical method within a statistically efficient design, researchers can reduce animal numbers.


Assuntos
Protetores contra Radiação/administração & dosagem , Protetores contra Radiação/toxicidade , Projetos de Pesquisa/estatística & dados numéricos , Toxicologia/estatística & dados numéricos , Animais , Teorema de Bayes , Simulação por Computador , Relação Dose-Resposta a Droga , Humanos , Dose Letal Mediana , Razão de Chances , Probabilidade , Toxicologia/métodos
14.
Osteoarthritis Cartilage ; 26(6): 783-789, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29673866

RESUMO

OBJECTIVE: Predicting who will develop osteoarthritis, assessing how rapidly their disease will progress and monitoring early responses to treatment are key to the development of therapeutic agents able to treat this crippling disease and to their future clinical use. Statistical Shape Modelling (SSM) enables quantification of variations in multiple geometric measures describing the whole hip joint to be considered in concert. This prospective study evaluates the responsiveness of SSM to changes in hip-shape within 1 year. METHODS: Sixty-two people, mean age 67.1 yrs, were recruited. Dual-energy X-ray Absorptiometry images were taken at three timepoints (baseline, 6 and 12 months). Based on Kellgren-Lawrence grading (KLG) of their baseline images, subjects were classified into control/doubtful OA: KLG < 1 in both hips; moderate OA: KLG = 2; and severe OA: KLG ≥ 3 in their most severe hip. Morphology was quantified using SSM and changes in shape were assessed using generalised estimating equations. Standardized response means (SRMs) were calculated for the first and second 6 month periods, then the full 12 months. RESULTS: Disease severity ranged from KLG0-KLG4 in the 124 hips assessed at baseline. Three SSM modes (Modes 1, 3 and 4) were associated with OA severity. Across the whole cohort, SRM magnitudes ranged from 0.16 to 0.63. The greatest subgroup SRM (magnitude 0.91) was observed over 12 months in those subjects with moderate OA (KLG2). CONCLUSIONS: We have demonstrated that SSM can capture changes in hip shape over 6 and 12 months across the entire hip joint providing a sensitive measure of hip OA progression.


Assuntos
Absorciometria de Fóton , Osteoartrite do Quadril/diagnóstico por imagem , Osteoartrite do Quadril/patologia , Idoso , Progressão da Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Estatísticos , Estudos Prospectivos , Fatores de Tempo
15.
Clin Radiol ; 73(8): 758.e19-758.e25, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29731127

RESUMO

AIM: To assess the safety of selective use of triple assessment with omission of radiological assessment proposed in patients <40-years old. MATERIALS AND METHODS: Data were collected retrospectively for all patients seen in the one-stop breast clinic between January 2014 and August 2015. Demographics, symptoms, diagnostics, and treatment details were recorded. Subgroup and logistic regression analysis was performed to identify predictors for breast cancer. RESULTS: Of the 3,305 patients included, 95.6% (n=3,161) were first-time referrals. 57.6% (n=1,903) had a breast lump, and 4% (n=133) had a high-risk family history; 75.6% (n=2,499) underwent imaging and 16.7% (n=552) underwent a biopsy. The median age was 29 years (interquartile range [IQR]=25-34). Breast cancer was diagnosed in 29 cases (0.88%) and 3.2% (n=105) had surgery. Median referral-to-diagnosis time was 13 days (IQR=9-14) and referral-to-surgery time was 44 days (IQR=34-95). Patients with breast cancer were significantly older (33 versus 28 years, p=0.016). All patients were first-time referrals. Most patients had a breast lump with low suspicion on clinical examination and breast cancer identified on imaging. Time-to-diagnosis (12 versus 14 days, p=0.017) and time-to-surgery (37 versus 67 days, p=0.012) was significantly shorter in the breast cancer group. Comparative older age (odds ratio [OR]=1.08, 95% confidence interval [CI]: 1.01-1.15) and breast lump (OR=11.43,95% CI: 2.72-48.07) were the only significant predictors of cancer on uni/multivariate regression. CONCLUSIONS: Triple assessment is also the best practice for all patients in the younger age group. This cohort should not be treated any differently regarding one-stop clinic infrastructure as the cancers detected were not clinically malignant. Missed cancers in this age group would have significant personal, clinical, and legal consequences.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Adulto , Fatores Etários , Biópsia com Agulha de Grande Calibre , Neoplasias da Mama/patologia , Neoplasias da Mama/cirurgia , Neoplasias da Mama Masculina/diagnóstico por imagem , Neoplasias da Mama Masculina/patologia , Neoplasias da Mama Masculina/cirurgia , Diagnóstico Diferencial , Detecção Precoce de Câncer , Feminino , Humanos , Masculino , Mamografia , Valor Preditivo dos Testes , Estudos Retrospectivos , Fatores de Risco , Tempo para o Tratamento , Ultrassonografia Mamária
16.
Biochim Biophys Acta ; 1862(7): 1337-44, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27085070

RESUMO

BACKGROUND AND AIMS: Non-alcoholic fatty liver disease is now the leading liver disease in North America. The progression of non-alcoholic fatty liver disease to the inflammatory condition, non-alcoholic steatohepatitis is complex and currently not well understood. Intestinal microbial dysbiosis has been implicated in the development of non-alcoholic fatty liver disease and progression of non-alcoholic steatohepatitis. Volatile organic compounds are byproducts of microbial metabolism in the gut that may enter portal circulation and have hepatotoxic effects contributing to the pathogenesis of non-alcoholic steatohepatitis. To test this hypothesis, we measured volatile organic compounds in cecal luminal contents and portal venous blood in a mouse model of non-alcoholic steatohepatitis. METHODS: Gas chromatography-mass spectrometry analysis was conducted on cecal content and portal vein blood for volatile organic compound detection from mice fed a methionine and choline deficient diet, which induces non-alcoholic steatohepatitis. The colonic microbiome was studied by 16S rRNA gene amplification using the Illumina MiSeq platform. RESULTS: Sixty-eight volatile organic compounds were detected in cecal luminal content, a subset of which was also present in portal venous blood. Importantly, differences in portal venous volatile organic compounds were associated with diet-induced steatohepatitis establishing a biochemical link between gut microbiota-derived volatile organic compounds and increased susceptibility to non-alcoholic steatohepatitis. CONCLUSION: Our model creates a novel tool to further study the role of gut-derived volatile organic compounds in the pathogenesis of non-alcoholic steatohepatitis.


Assuntos
Inflamação/microbiologia , Fígado/irrigação sanguínea , Hepatopatia Gordurosa não Alcoólica/sangue , Hepatopatia Gordurosa não Alcoólica/microbiologia , Veia Porta/microbiologia , Compostos Orgânicos Voláteis/análise , Animais , Bactérias/isolamento & purificação , Células Cultivadas , Modelos Animais de Doenças , Inflamação/patologia , Mediadores da Inflamação/análise , Fígado/microbiologia , Fígado/patologia , Macrófagos/microbiologia , Macrófagos/patologia , Masculino , Camundongos Endogâmicos C57BL , Microbiota , Hepatopatia Gordurosa não Alcoólica/patologia , Veia Porta/patologia
17.
Opt Express ; 25(14): 16072-16082, 2017 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-28789115

RESUMO

By using free-running independent femtosecond OPOs with a repetition-rate difference of 500 Hz we demonstrate methane absorption spectroscopy with spectral coverage simultaneously spanning the methane P, Q and R branches and with a resolution of 0.5 cm-1. Absolute optical frequency calibration with an accuracy of 0.25 cm-1 (0.27 nm) is achieved from simultaneous repetition-rate and carrier-envelope-offset frequency measurements, without the need for any optical reference. The calibration technique allows registration and averaging of consecutively acquired dual-comb spectra, leading to a high quality and low-noise absorbance measurement in good agreement with the HITRAN database.

18.
Opt Express ; 25(13): 14473-14482, 2017 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-28789033

RESUMO

In this work we present an Autocorrelation z-scan technique to measure, simultaneously, the spatial and temporal distribution of femtosecond pulses near the focal region of lenses. A second-order collinear autocorrelator is implemented before the lens under test to estimate the pulse width. Signals are obtained by translating a Two Photon Absorption (TPA) sensor along the optical axis and by measuring the second-order autocorrelation trace at each position z. The DC signal, which is typically not considered important, is taken into account since we have found that this signal provides relevant information. Experimental results are presented for different lenses and input wavefronts.

19.
Sex Transm Infect ; 93(3): 203-206, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-27519259

RESUMO

OBJECTIVES: There is considerable public health concern about the combining of sex and illicit drugs (chemsex) among gay men. With a view to inform supportive therapeutic and clinical interventions, we sought to examine the motivations for engaging in chemsex among gay men living in South London. METHODS: Community advertising recruited 30 gay men for qualitative semi-structured interview. Aged between 21 and 53 years, all lived in South London in the boroughs of Lambeth, Southwark and Lewisham and all had combined crystal methamphetamine, mephedrone and/or γ-hydroxybutyric acid/γ-butyrolactone with sex in the past 12 months. Transcripts were subjected to a thematic analysis. RESULTS: We broadly distinguished two groups of reasons for combining sex and drugs, within which we described eight distinct motivations. The first major group of motivations for combining drugs with sex was that drugs provide the means by which men can have the sex they desire by increasing libido, confidence, disinhibition and stamina. The second major group of motivations for chemsex was that drugs enhance the qualities of the sex that men value. Drugs made other men seem more attractive, increased physical sensations, intensified perceptions of intimacy and facilitated a sense of sexual adventure. CONCLUSION: Analysis revealed that sexualised drug use provides both motivation and capability to engage in the kinds of sex that some gay men value: sex that explores and celebrates adventurism. Those services providing (talking) interventions to men engaging in chemsex should consider these benefits of sexualised drug use alongside the harms arising.


Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Homossexualidade Masculina/psicologia , Motivação , Comportamento Sexual/efeitos dos fármacos , Comportamento Sexual/psicologia , Parceiros Sexuais/psicologia , Transtornos Relacionados ao Uso de Substâncias/psicologia , Adulto , Nível de Alerta/efeitos dos fármacos , Humanos , Drogas Ilícitas/efeitos adversos , Inibição Psicológica , Entrevistas como Assunto , Libido/efeitos dos fármacos , Londres , Masculino , Metanfetamina/administração & dosagem , Metanfetamina/efeitos adversos , Pessoa de Meia-Idade , Pesquisa Qualitativa , Assunção de Riscos , Adulto Jovem
20.
Appl Opt ; 56(17): 5047-5053, 2017 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-29047653

RESUMO

We show that in a nonlinear microscopy system the effects of chromatic and spherical aberrations are revealed by a difference in the focal positions corresponding to the shortest pulse duration and the minimum lateral resolution. By interpreting experimental results from a high-numerical-aperture two-photon microscope using a previously reported spatio-temporal model, we conclude that the two-photon autocorrelation of the pulses at the focal plane can be used to minimize both the chromatic and spherical aberrations of the system. Based on these results, a possible optimization strategy is proposed whereby the objective lens is first adjusted for minimum autocorrelation duration, and then the wavefront before the objective is modified to maximize the autocorrelation intensity.

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