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1.
J Therm Spray Technol ; 31(4): 866-907, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-37520275

RESUMO

Cold Spray (CS) is a deposition process, part of the thermal spray family. In this method, powder particles are accelerated at supersonic speed within a nozzle; impacts against a substrate material triggers a complex process, ultimately leading to consolidation and bonding. CS, in its modern form, has been around for approximately 30 years and has undergone through exciting and unprecedented developmental steps. In this article, we have summarized the key inventions and sub-inventions which pioneered the innovation aspect to the process that is known today, and the key breakthroughs related to the processing of materials CS is currently mastering. CS has not followed a liner path since its invention, but an evolution more similar to a hype cycle: high initial growth of expectations, followed by a decrease in interest and a renewed thrust pushed by a number of demonstrated industrial applications. The process interest is expected to continue (gently) to grow, alongside with further development of equipment and feedstock materials specific for CS processing. A number of current applications have been identified the areas that the process is likely to be the most disruptive in the medium-long term future have been laid down.

2.
APL Photonics ; 6(6)2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35693725

RESUMO

Nucleic acids and proteins are the two most important target types used in molecular diagnostics. In many instances, simultaneous sensitive and accurate detection of both biomarkers from the same sample would be desirable, but standard detection methods are highly optimized for one type and not cross-compatible. Here, we report the simultaneous multiplexed detection of SARS-CoV-2 RNAs and antigens with single molecule sensitivity. Both analytes are isolated and labeled using a single bead-based solid-phase extraction protocol, followed by fluorescence detection on a multi-channel optofluidic waveguide chip. Direct amplification-free detection of both biomarkers from nasopharyngeal swab samples is demonstrated with single molecule detection sensitivity, opening the door for ultrasensitive dual-target analysis in infectious disease diagnosis, oncology, and other applications.

3.
Opt Express ; 28(22): 33019-33027, 2020 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-33114971

RESUMO

Rapid and accurate diagnosis of bacterial infections resistant to multiple antibiotics requires development of new bio-sensors for differentiated detection of multiple targets. This work demonstrates 7x multiplexed detection for antibiotic-resistance bacterial screening on an optofluidic platform. We utilize spectrally multiplexed multi-spot excitation for simultaneous detection of nucleic acid strands corresponding to bacterial targets and resistance genes. This is enabled by multi-mode interference (MMI) waveguides integrated in an optofluidic device. We employ a combinatorial three-color labeling scheme for the nucleic acid assays to scale up their multiplexing capability to seven different nucleic acids, representing three species and four resistance genes.


Assuntos
Proteínas de Bactérias/genética , DNA Bacteriano/genética , Farmacorresistência Bacteriana/genética , Enterobacter aerogenes/genética , Escherichia coli/genética , Klebsiella pneumoniae/genética , Técnicas de Amplificação de Ácido Nucleico , Antibacterianos/farmacologia , Proteínas de Bactérias/efeitos dos fármacos , Enterobacter aerogenes/efeitos dos fármacos , Klebsiella pneumoniae/efeitos dos fármacos , Dispositivos Lab-On-A-Chip , Testes de Sensibilidade Microbiana , Dispositivos Ópticos
4.
Lab Chip ; 20(20): 3763-3771, 2020 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-33048071

RESUMO

Bacterial pathogens resistant to antibiotics have become a serious health threat. Those species which have developed resistance against multiple drugs such as the carbapenems, are more lethal as these are last line therapy antibiotics. Current diagnostic tests for these resistance traits are based on singleplex target amplification techniques which can be time consuming and prone to errors. Here, we demonstrate a chip based optofluidic system with single molecule sensitivity for amplification-free, multiplexed detection of plasmids with genes corresponding to antibiotic resistance, within one hour. Rotating disks and microfluidic chips with functionalized polymer monoliths provided the upstream sample preparation steps to selectively extract these plasmids from blood spiked with E. coli DH5α cells. Waveguide-based spatial multiplexing using a multi-mode interference waveguide on an optofluidic chip was used for parallel detection of three different carbapenem resistance genes. These results point the way towards rapid, amplification-free, multiplex analysis of antibiotic-resistant pathogens.


Assuntos
Antibacterianos , Escherichia coli , Antibacterianos/farmacologia , Carbapenêmicos , Resistência Microbiana a Medicamentos , Escherichia coli/genética , Testes de Sensibilidade Microbiana , Plasmídeos/genética
5.
Chronobiol Int ; 37(9-10): 1430-1440, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32954831

RESUMO

Driver sleepiness is a leading contributor to road crashes. Sleep-related crashes are more likely to involve collision with a stationary object than non-sleep-related crashes. The mechanism underpinning this is unknown; one potential explanation may be an increased propensity for change blindness. Twenty-four drivers with at least one year of independent driving experience completed two simulated drives: one following a normal night of sleep (7-8 h) and one following sleep restriction (5 h). The drive consisted of 5 laps of an 11.3 km circuit, taking approximately 45 min. Each lap comprised half urban and half rural driving environments. Twenty times during the drive the visual screen was blanked for 500 ms, and when it reappeared participants were asked whether there were any changes. Twelve times a change occurred, and eight times no change occurred. Additionally, four unexpected changes occurred; for example, the language of the road signs was changed from English to German. At the end of each drive, participants were asked if anything unusual occurred. Sleep loss resulted in significantly increased subjective sleepiness and subjective workload. Driving in an urban environment did not increase alertness; subjective sleepiness ratings did not significantly differ between urban and rural environments. Change detection accuracy for both cued and unexpected changes was not significantly affected by sleep loss. In line with previous research, accuracy was greater for changes with high safety relevance and those occurring in rural environments. Collectively the findings of the study suggest that increase change blindness is probably not a contributor to sleep-related road crashes; however, future on-road research and with greater levels of sleep loss is needed to confirm findings.


Assuntos
Condução de Veículo , Ritmo Circadiano , Acidentes de Trânsito , Atenção , Humanos , Sono , Vigília
6.
Artigo em Inglês | MEDLINE | ID: mdl-37584007

RESUMO

Background: 1.1.Inflammatory Bowel Disease (IBD) are the manifestation of overzealous dys-regulated immune response in the intestinal tract, directed primarily against the indigenous microbes combined with defective functioning of anti-inflammatory pathways. Finding a trustable lead to predicting de novo Crohn's Disease (CD) prior to performing "pouch surgery", Restorative Proctocolectomy (RPC) with Ileal Pouch-Anal Anastomosis (IPAA) for UC and/or Indeterminate Colitis (IC) is clinically important and remains debatable. De novo CD is a subsequent long-term postoperative complication in IBD patients with Ulcerative Colitis (UC) undergoing IPAA. Herewith we discuss this understanding in laboratory-based basic science research, with its molecular application as a possible corner stone tool for clinical progress and success in the IBD Clinic. Crypt Paneth cell (PCs) secreted enteroendocrine alpha-defensin 5 (DEFA5)" if developed properly is likely to solve diagnostic and prognostic difficulty in IBD Clinics. DEFA5 has shown the ability to differentiate the predominant subtypes of colonic IBD (CC vs. UC) at first endoscopy biopsy, avoiding diagnosis delay prior to colectomy. In addition, DEFA5 accurately circumvents indeterminate colitis (IC) patients into accurate IBD subtype (UC or CC). Further, DEFA5 can be used in selecting CC patients that may have positive outcomes after IPAA surgery [1]. Furthermore, likewise, DEFA5 can predict UC patients likely to have positive or poor outcome, e.g. those patients that are likely to transform/ convert and adhere to de novo Crohn's after IPAA can be picked up in endoscopy biopsy before surgery. Aim: 1.2.To assessed comprehensive state-of-the-art understanding domains on the de novo Crohn's disease subsequent to IPAA surgery for ulcerative colitis. Methods: 1.3.A literature search based on preferred reporting items for over-review and meta-analysis protocols (PRISMA-P) was performed. A comprehensive current search of PubMed, MEDLINE, CINAHL, Embase, Google® search engine and Cochrane Database of collected reviews was performed from January 1990 through December 2018. The search consists of retrospective studies and case reports of reporting postoperative de novo CD incidence and adverse events. Secondary and hand/manual searches of reference lists, other studies cross-indexed by authors, reviews, commentaries, books and meeting abstracts were also performed. Studies were included only if the diagnosis of de novo CD was established clinically and histologically based on inflammation of afferent limb(s) or perianal disease. The search excluded non-English language and non-human studies as well as editorials. Results: 1.4.Published data on de novo CD developing after RPC with IPAA are still limited. A total of three hundred and sixty-five (#365) patients in 13 publications reported de novo CD after a median follow-up of 66 (range: 3-236) months. All patients were diagnosed with clinically active pouch CD during follow-up surveillance after IPAA for UC or IC. A de novo CD diagnosis depended on either inflammation in the mucosa involving the small intestine proximal to the ileal pouch any time after IPAA surgery and/or when perianal complications developed after closure of a temporary diverting loop ileostomy. Successful management is facilitated by co-operation within a multidisciplinary team of gastroenterologists and colorectal surgeons and closely involving the patient in therapeutic decisions. Awareness of symptoms leads to timely consultation, diagnosis, treatment and restoration of intestinal continuity. Conclusion: 1.5.The nature history and risk of de novo CD after IPAA for UC remains debatable. Chronic pouchitis and/or pouch failure often precedes a diagnosis of de novo CD. A successful management is facilitated by a triad cooperation between gastroenterologists, colorectal surgeons and the patient.

7.
Artigo em Inglês | MEDLINE | ID: mdl-37615012

RESUMO

Introduction: 1.1.Inflammatory Bowel Disease (IBD) is recklessly evolving worldwide as incautious disaster, especially in developing nations as a regional duplicitous emergence disease. It has come to light that adaptive Western culture, rapid urbanization lifestyle in the developing nations has been seen to be associated with this increasing trend incidence. Apparent unclassified strategic challenge assessment of how key trends and uncertainties might lead the world over the next decades to help developing nations and plan for the long term. Healthcare professionals are faced with limited resource and unequipped laboratories for IBD diagnostics, prognostics and monitoring management. Limited knowledge on IBD among developing nation's physician's/healthcare providers is painstaking and indisputable challenge. With the emergence of advanced communications technology, the internet offers diverse, substantial, easily accessible, and educational resources that are more time- and cost-efficient than conventional modes of knowledge acquisition. An On-Line Web-Based Resources about IBD, as a guide would greatly assist health professionals and patients. Methods: 1.2.We performed a literature search according to PRISMA-P (preferred reporting items for review and meta-analysis and searches in PubMed (MEDLINE database) to identify and select peer-reviewed articles allied to web-based educational accoutrements for IBD. Results: 1.3.In developing nations, locally trained physicians have limited knowledge on IBD. Mostly, IBD is not included in their training Core Curriculum and research in this field/area is limited in these countries. The healthcare approaches, both at the primary care and referral levels, many times lack the essential regular clinical guidance and laboratory evaluation assessments needs for monitoring patients. Moreover, increasing treatment costs impose additional burden on the healthcare systems. Expensive pharmacological biosimilar and biologic agents/drugs, new treatment targets, and new quality indicators in patient health quality of life and care are significant challenge in addition to early manifestations of IBD are likely to be missed at most health institutions. Conclusion: 1.4.We herewith summarize an on-line web-based e-learning guide for IBD-related educational resources to assist physicians, healthcare personnel and patients worldwide, especially in the developing nations where the epidemiological monitoring studies are limited, due to a lack of medical surveillance systems and reliable and unified registries and databases.

8.
Nat Commun ; 10(1): 3712, 2019 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-31420559

RESUMO

Nanopore-based single nanoparticle detection has recently emerged as a vibrant research field with numerous high-impact applications. Here, we introduce a programmable optofluidic chip for nanopore-based particle analysis: feedback-controlled selective delivery of a desired number of biomolecules and integration of optical detection techniques on nanopore-selected particles. We demonstrate the feedback-controlled introduction of individual biomolecules, including 70S ribosomes, DNAs and proteins into a fluidic channel where the voltage across the nanopore is turned off after a user-defined number of single molecular insertions. Delivery rates of hundreds/min with programmable off-times of the pore are demonstrated using individual 70S ribosomes. We then use real-time analysis of the translocation signal for selective voltage gating of specific particles from a mixture, enabling selection of DNAs from a DNA-ribosome mixture. Furthermore, we report optical detection of nanopore-selected DNA molecules. These capabilities point the way towards a powerful research tool for high-throughput single-molecule analysis on a chip.


Assuntos
Dispositivos Lab-On-A-Chip , Nanoporos , Dispositivos Ópticos , Imagem Individual de Molécula/instrumentação , DNA , Escherichia coli , Ribossomos
9.
Tech Coloproctol ; 23(6): 611, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31168776

RESUMO

Unfortunately, the "Informed consent" statement was incorrectly published in the original version. The complete correct reference should read as follows.

10.
Sci Total Environ ; 659: 1555-1566, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31096365

RESUMO

Prescribed grassland fires in the Flint Hills region of central Kansas and northern Oklahoma are a common tool for land management. Local to regional scale impacts on air quality from grassland fires in this region are not well understood, which is important as these types of prescribed fires may increase in the future to preserve broader areas of native grasses in the central U.S. Routine air quality and deposition measurements from sites in and near the Flint Hills were examined for coincident increases during periods of increased prescribed grassland fires. Prescribed fire activity in this region was quantified using satellite detections and multiple publicly available data products of area burned information. March and April comprise over half (41 to 93%) of all annual fire detections in the Flint Hills region seen from satellites between 2007 and 2018 excluding drought years. Annual total fire detections in this region range between 1 and 12 thousand and account for approximately 3% of all fire detections in the contiguous U.S. Annual acres burned ranged from 0.2 to 2 million acres based on U.S. EPA's National Emission Inventory, which accounts for 4 to 38% of grasslands in the area. A comparison of weekly standardized anomalies suggests a relationship between periods of increased grassland fire activity and elevated levels of PM2.5 organic carbon, elemental carbon, and potassium. Daily 1-hr maximum ozone (O3), ammonia (NH3), sulfur dioxide (SO2), and oxidized nitrogen gases measured at Konza Prairie also had increased levels when prescribed grassland fire activity was highest. This detailed characterization of prescribed fire activity in the Flint Hills and associated air quality impacts will benefit future efforts to understand changes in atmospheric composition due to changing land management practices.

11.
Tech Coloproctol ; 23(4): 325-332, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31016550

RESUMO

BACKGROUND: The aim of the present study was to evaluate patient factors that affect the progression of anal dysplasia in human immunodeficiency virus (HIV)-positive individuals. METHODS: A retrospective cohort study of HIV-positive adults with human papilloma virus related anal lesions was performed from 2012 to 2017. All patients underwent surgical excision or biopsy and fulguration of lesions in the operating room without using high resolution anoscopy. Patients with initial presentation of squamous cell carcinoma were excluded. The study was designed to investigate progression between the first available histology and either the follow up histology or a negative examination. Patient files were reviewed and data was collected. A bivariate analysis of continuous and categorical variables was performed. RESULTS: One hundred and sixty-one patients met the inclusion criteria. Ninety-seven percent were male. Mean age was 41 years. Thirty-five percent were African American and 47% were Caucasian. After a median follow-up interval of 331 days (IQR 120-615 days) 14 (9%) of patients had progression of disease. Visible lesions on initial presentation, as opposed to lesions found  in patients undergoing examination under anesthesia because of HSIL on anal pap smear, was associated with progression (p = 0.0.2). A lower initial CD4 count (p = 0.01) and initial surgical pathology of anal condylomata (p = 0.01) were also associated with progression. High-risk serotype was associated with no change or regression (p = 0.01). CONCLUSIONS: In our large cohort of HIV-positive patients treated without high resolution anoscopy the rate of progression was low.  Most notably, visible lesions at initial presentation and CD4 count when lower were associated with progression. Initial surgical pathology of anal condylomata was associated with progression, while high-risk serotypes correlated with regression or stability. Identification of risk factors has important implications concerning postoperative surveillance and counseling of HIV-positive patients with anal condylomata/ anal dysplasia.


Assuntos
Neoplasias do Ânus/patologia , Carcinoma in Situ/patologia , Carcinoma de Células Escamosas/patologia , Infecções por HIV/patologia , HIV , Adulto , Canal Anal/patologia , Canal Anal/virologia , Neoplasias do Ânus/virologia , Biópsia , Carcinoma in Situ/virologia , Carcinoma de Células Escamosas/virologia , Condiloma Acuminado/patologia , Condiloma Acuminado/virologia , Progressão da Doença , Feminino , Infecções por HIV/virologia , Humanos , Masculino , Proctoscopia , Estudos Retrospectivos , Fatores de Risco
12.
Neuromuscul Disord ; 29(3): 198-212, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30765255

RESUMO

Myotonic dystrophy type 1 (DM1) is one of the most common muscular dystrophies in adults. This review summarises the current literature regarding the natural history of respiratory dysfunction in DM1, the role of central respiratory drive and peripheral respiratory muscle involvement and its significance in respiratory function, and investigates the relationship between genetics (CTG repeat length) and respiratory dysfunction. The review included all articles that reported spirometry on 10 or more myotonic dystrophy patients. The final review included 55 articles between 1964 and 2017. The major conclusions of this review were (1) confirmation of the current consensus that respiratory dysfunction, predominantly a restrictive ventilatory pattern, is common in myotonic dystrophy and is associated with alveolar hypoventilation, chronic hypercapnia, and sleep disturbance in the form of sleep apnoea and sleep related disordered breathing; (2) contrary to commonly held belief, there is no consensus in the literature regarding the relationship between CTG repeat length and severity of respiratory dysfunction and a relationship has not been established; (3) the natural history and time-course of respiratory functional decline is very poorly understood in the current literature; (4) there is a consensus that there is a significant involvement of central respiratory drive in this alveolar hypoventilation however the current literature does not identify the mechanism for this.


Assuntos
Hipercapnia/fisiopatologia , Distrofia Miotônica/fisiopatologia , Transtornos Respiratórios/fisiopatologia , Músculos Respiratórios/fisiopatologia , Transtornos do Sono-Vigília/fisiopatologia , Humanos , Hipercapnia/complicações , Hipercapnia/genética , Distrofia Miotônica/genética , Transtornos Respiratórios/complicações , Transtornos do Sono-Vigília/genética , Expansão das Repetições de Trinucleotídeos/genética
13.
Optica ; 6(9): 1130-1131, 2019 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-33598506

RESUMO

We use optical trapping to deliver molecular targets to the vicinity of a nanopore for high-throughput single molecule analysis on an optofluidic chip. DNA detection rates increase over 80× to enable detection at attomolar concentrations.

14.
Biosens Bioelectron ; 91: 489-496, 2017 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-28073029

RESUMO

An automated microfluidic sample preparation multiplexer (SPM) has been developed and evaluated for Ebola virus detection. Metered air bubbles controlled by microvalves are used to improve bead-solution mixing thereby enhancing the hybridization of the target Ebola virus RNA with capture probes bound to the beads. The method uses thermally stable 4-formyl benzamide functionalized (4FB) magnetic beads rather than streptavidin coated beads with a high density of capture probes to improve the target capture efficiency. Exploiting an on-chip concentration protocol in the SPM and the single molecule detection capability of the antiresonant reflecting optical waveguide (ARROW) biosensor chip, a detection limit of 0.021pfu/mL for clinical samples is achieved without target amplification. This RNA target capture efficiency is two orders of magnitude higher than previous results using streptavidin beads and the limit of detection (LOD) improves 10×. The wide dynamic range of this technique covers the whole clinically applicable concentration range. In addition, the current sample preparation time is ~1h which is eight times faster than previous work. This multiplexed, miniaturized sample preparation microdevice establishes a key technology that intended to develop next generation point-of-care (POC) detection system.


Assuntos
Técnicas Biossensoriais/instrumentação , Ebolavirus/isolamento & purificação , Doença pelo Vírus Ebola/virologia , Técnicas Analíticas Microfluídicas/instrumentação , RNA Viral/análise , Desenho de Equipamento , Doença pelo Vírus Ebola/diagnóstico , Humanos , Limite de Detecção , Hibridização de Ácido Nucleico , Sistemas Automatizados de Assistência Junto ao Leito , Extração em Fase Sólida/instrumentação , Estreptavidina/química
15.
Accid Anal Prev ; 99(Pt B): 459-464, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26653707

RESUMO

Driver sleepiness is a major contributor to severe crashes and fatalities on our roads. Many people continue to drive despite being aware of feeling tired. Prevention relies heavily on education campaigns as it is difficult to police driver sleepiness. The video sharing social media site YouTube is extremely popular, particularly with at risk driver demographics. Content and popularity of uploaded videos can provide insight into the quality of publicly accessible driver sleepiness information. The purpose of this research was to answer two questions; firstly, how prevalent are driver sleepiness videos on YouTube? And secondly, what are the general characteristics of driver sleepiness videos in terms of (a) outlook on driver sleepiness, (b) tone, (c) countermeasures to driver sleepiness, and, (d) driver demographics. Using a keywords search, 442 relevant videos were found from a five year period (2nd December 2009-2nd December 2014). Tone, outlook, and countermeasure use were thematically coded. Driver demographic and video popularity data also were recorded. The majority of videos portrayed driver sleepiness as dangerous. However, videos that had an outlook towards driver sleepiness being amusing were viewed more often and had more mean per video comments and likes. Humorous videos regardless of outlook, were most popular. Most information regarding countermeasures to deal with driver sleepiness was accurate. Worryingly, 39.8% of videos with countermeasure information contained some kind of ineffective countermeasure. The use of humour to convey messages about the dangers of driver sleepiness may be a useful approach in educational interventions.


Assuntos
Condução de Veículo/estatística & dados numéricos , Fadiga/epidemiologia , Sono , Mídias Sociais/estatística & dados numéricos , Gravação em Vídeo/estatística & dados numéricos , Humanos , Internet
16.
J Dent Res ; 96(2): 208-216, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27770039

RESUMO

Extracellular DNA (eDNA) has been identified in the matrix of many different monospecies biofilms in vitro, including some of those produced by oral bacteria. In many cases, eDNA stabilizes the structure of monospecies biofilms. Here, the authors aimed to determine whether eDNA is an important component of natural, mixed-species oral biofilms, such as plaque on natural teeth or dental implants. To visualize eDNA in oral biofilms, approaches for fluorescently stained eDNA with either anti-DNA antibodies or an ultrasensitive cell-impermeant dye, YOYO-1, were first developed using Enterococcus faecalis, an organism that has previously been shown to produce extensive eDNA structures within biofilms. Oral biofilms were modelled as in vitro "microcosms" on glass coverslips inoculated with the natural microbial population of human saliva and cultured statically in artificial saliva medium. Using antibodies and YOYO-1, eDNA was found to be distributed throughout microcosm biofilms, and was particularly abundant in the immediate vicinity of cells. Similar arrangements of eDNA were detected in biofilms on crowns and overdenture abutments of dental implants that had been recovered from patients during the restorative phase of treatment, and in subgingival dental plaque of periodontitis patients, indicating that eDNA is a common component of natural oral biofilms. In model oral biofilms, treatment with a DNA-degrading enzyme, NucB from Bacillus licheniformis, strongly inhibited the accumulation of biofilms. The bacterial species diversity was significantly reduced by treatment with NucB and particularly strong reductions were observed in the abundance of anaerobic, proteolytic bacteria such as Peptostreptococcus, Porphyromonas and Prevotella. Preformed biofilms were not significantly reduced by NucB treatment, indicating that eDNA is more important or more exposed during the early stages of biofilm formation. Overall, these data demonstrate that dental plaque eDNA is potentially an important target for oral biofilm control.


Assuntos
DNA Bacteriano/fisiologia , Placa Dentária/etiologia , Biofilmes/crescimento & desenvolvimento , Implantes Dentários/microbiologia , Placa Dentária/microbiologia , Placa Dentária/ultraestrutura , Enterococcus faecalis/genética , Enterococcus faecalis/metabolismo , Humanos , Microscopia Eletrônica de Varredura , Saliva/metabolismo
17.
Artigo em Inglês | MEDLINE | ID: mdl-27547024

RESUMO

Silicon-based optofluidic devices are very attractive for applications in biophotonics and chemical sensing. Understanding and controlling the properties of their dielectric waveguides is critical for the performance of these chips. We report that thermal annealing of PECVD-grown silicon dioxide (SiO2) ridge waveguides results in considerable improvements to optical transmission and particle detection. There are two fundamental changes that yield higher optical transmission: (1) propagation loss in solid-core waveguides is reduced by over 70%, and (2) coupling efficiencies between solid- and liquid-core waveguides are optimized. The combined effects result in improved optical chip transmission by a factor of 100-1000 times. These improvements are shown to arise from the elimination of a high-index layer at the surface of the SiO2 caused by water absorption into the porous oxide. The effects of this layer on optical transmission and mode confinement are shown to be reversible by alternating subjection of waveguides to water and subsequent low temperature annealing. Finally, we show that annealing improves detection of fluorescent analytes in optofluidic chips with a signal-to-noise ratio improvement of 166x and a particle detection efficiency improvement of 94%.

18.
BMJ Support Palliat Care ; 6(4): 474-478, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27316636

RESUMO

OBJECTIVES: The objectives of this study were to explore medical students' experiences of communicating with patients and their carers about death and dying, and to assess whether using high-fidelity simulation improved students' confidence in discussing cardiopulmonary resuscitation. METHODS: This qualitative study was carried out at a hospital in the south of England. Participants were 7 final-year medical students. Tutorials were developed using high-fidelity simulation to teach communication skills regarding discussion of cardiopulmonary resuscitation with patients and carers. Scenarios involved a simulated ward environment, a high-fidelity simulation mannequin and actor playing the role of a carer. Data were collected through joint interviews carried out by one researcher which were audio recorded and transcribed verbatim. The same researcher analysed the data using framework analysis. RESULTS: Students reported a lack of experience observing conversations with patients and carers about death and dying. They also reported a lack of opportunities to interact with dying patients during their training. Barriers reported by students included healthcare professionals' and patients' attitudes. Students reported a lack of confidence and preparedness to have consultations with patients and carers about death, dying and cardiopulmonary resuscitation as junior doctors. They perceived role-play scenarios observed by their peers to be stressful, and this detracted from the learning experience. Students reported that the high-fidelity simulation scenarios were more realistic than low-fidelity ('role-play') scenarios. This improved the learning gained from the sessions and improved confidence among some students. CONCLUSIONS: This study has suggested that high-fidelity simulation may be a useful adjunct for undergraduate communication skills training in palliative medicine. Further research is required to assess whether improvements in confidence described by students in this study translate to discernible improvements in competence, and whether using high-fidelity simulation in this setting is cost-effective.


Assuntos
Reanimação Cardiopulmonar/educação , Educação de Graduação em Medicina/métodos , Comunicação em Saúde/métodos , Treinamento com Simulação de Alta Fidelidade/métodos , Relações Médico-Paciente , Assistência Terminal/métodos , Adulto , Competência Clínica , Feminino , Humanos , Masculino , Cuidados Paliativos/métodos , Simulação de Paciente , Pesquisa Qualitativa , Adulto Jovem
19.
World J Nucl Med ; 15(2): 102-8, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27134560

RESUMO

Understanding the range and variability of normal, benign degenerative, and malignant (18)F sodium fluoride ((18)F NaF) positron emission tomography/computed tomography (PET/CT) uptake is important in influencing clinical interpretation. Further, it is essential for the development of realistic semiautomated quantification techniques and simulation models. The purpose of this study is to determine the range of these values in a clinically relevant patient population with prostate cancer. (18)F NaF PET/CT scans were analyzed in patients with prostate cancer (n = 47) referred for evaluation of bone metastases. Mean and maximum standardized uptake values [SUVs (SUVmean and SUVmax)] were made in normal background regions (n = 470) including soft tissues (liver, aorta, bladder, adipose, brain, and paraspinal muscle) and osseous structures (T12 vertebral body, femoral diaphyseal cortex, femoral head medullary space, and ribs). Degenerative joint disease (DJD; n = 281) and bone metastases (n = 159) were identified and quantified by an experienced reader using all scan information including coregistered CT. For normal bone regions, the highest (18)F NaF PET SUVmean occurred in T12 (6.8 ± 1.4) and it also showed the lowest coefficient of variation (cv = 21%). For normal soft tissues, paraspinal muscles showed very low SUVmean (0.70 ± 0.11) and also showed the lowest variability (cv = 16%). Average SUVmean in metastatic lesions is higher than uptake in benign degenerative lesions but values showed a wide variance and overlapping values (16.3 ± 13 vs 11.1 ± 3.8; P < 0.00001). The normal (18)F NaF PET uptake values for prostate cancer patients in normal background, benign degenerative disease, and osseous metastases are comparable to those reported for a general population with a wide variety of diagnoses. These normal ranges, specifically for prostate cancer patients, will aid in clinical interpretation and also help to establish the basis of normal limits in a semiautomated data analysis algorithm.

20.
Appl Phys Lett ; 108(13): 131105, 2016 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-27076685

RESUMO

A hollow-core waveguide structure for on-chip atomic spectroscopy is presented. The devices are based on Anti-Resonant Reflecting Optical Waveguides and may be used for a wide variety of applications which rely on the interaction of light with gases and vapors. The designs presented here feature short delivery paths of the atomic vapor into the hollow waveguide. They also have excellent environmental stability by incorporating buried solid-core waveguides to deliver light to the hollow cores. Completed chips were packaged with an Rb source and the F = 3 ≥ F' = 2, 3, 4 transitions of the D2 line in 85Rb were monitored for optical absorption. Maximum absorption peak depths of 9% were measured.

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