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1.
Anal Bioanal Chem ; 416(3): 627-633, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37528269

RESUMO

The development and expansion of analytical methods for per- and polyfluoroalkyl substances (PFAS) in food are essential for the continued monitoring of the United States (US) food supply and assessments of dietary exposure. In March 2022, the European Union Reference Laboratory for Halogenated Persistent Organic Pollutants in Feed and Food (EURL POPs) released a guidance document covering priority PFAS of interest, including analytical method parameters and limits of quantification (LOQs). As a result, the Food and Drug Administration (FDA) began method extension work to incorporate ten new additional analytes to method C-010.02 including long-chain perfluorosulfonic acids, fluorotelomer sulfonates, and perfluorooctane sulfonamide. Four long-chain carboxylic acids were also validated across all foods, which were previously added to C-010.02 but only validated in seafood. In December 2022, the European Union published Commission Regulation 2022/2388, establishing maximum levels for perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorohexane sulfonic acid (PFHxS) in certain foodstuffs, primarily fish, molluscs, crustaceans, and eggs. As a result, the FDA method was evaluated for performance in reaching LOQs defined in Commission Regulation (EU) 2022/1431. The FDA method was found to be able to reach all required LOQs for analytes in matrices with established maximum levels. Currently, method detection limits (MDLs), which are used by the FDA as the lower limit for reporting PFAS in surveillance samples, were in the same range as defined indicative levels. With further method modifications, required LOQs could be met in fruits, vegetables, and milk. Reaching the lower targeted LOQs for these food matrices will require moving the method to an instrument that can provide increased signal:noise gains at the lower limits of quantification.


Assuntos
Ácidos Alcanossulfônicos , Poluentes Ambientais , Fluorocarbonos , Animais , Estados Unidos , Ácidos Alcanossulfônicos/análise , Fluorocarbonos/análise , Verduras , Exposição Dietética
2.
Anal Bioanal Chem ; 416(8): 1777-1785, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38280017

RESUMO

With increasing public awareness of PFAS, and their presence in biological and environmental media across the globe, comes a matching increase in the number of PFAS monitoring studies. As more matrices and sample cohorts are examined, there are more opportunities for matrix interferents to appear as PFAS where there are none (i.e., "seeing ghosts"), impacting subsequent reports. Addressing these ghosts is vital for the research community, as proper analytical measurements are necessary for decision-makers to understand the presence, levels, and potential risks associated with PFAS and protect human and environmental health. To date, PFAS interference has been identified in several matrices (e.g., food, shellfish, blood, tissue); however, additional unidentified interferents are likely to be observed as PFAS research continues to expand. Therefore, the aim of this commentary is several fold: (1) to create and support a publicly available dataset of all currently known PFAS analytical interferents, (2) to allow for the expansion of that dataset as more sources of interference are identified, and (3) to advise the wider scientific community on how to both identify and eliminate current or new analytical interference in PFAS analyses.


Assuntos
Fluorocarbonos , Poluentes Químicos da Água , Humanos , Poluentes Químicos da Água/análise , Fluorocarbonos/análise , Alimentos Marinhos/análise , Frutos do Mar/análise , Membrana Eritrocítica
3.
Can Fam Physician ; 68(6): e182-e189, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35701191

RESUMO

OBJECTIVE: To explore Canadian FPs' experiences with, perceived barriers to, and perceived facilitators of FP-initiated partner notification (PN) for HIV and other sexually transmitted infections (STIs), as well as to inform the development of tools that might enhance this work. DESIGN: Online survey. SETTING: British Columbia. PARTICIPANTS: A total of 146 FPs recruited through the Divisions of Family Practice community-based networks of FPs throughout the province. MAIN OUTCOME MEASURES: Family physicians' current STI and PN practices, opinions regarding FP-initiated PN, perceived barriers to and facilitators of FP-initiated PN, and preferred PN resources. RESULTS: More than 90% of FPs had diagnosed an STI within the past year, and most (60.3% to 96.6%, depending on the STI) told patients to inform their partners. Two-thirds (66.4%) felt that PN should not be done by FPs, and fewer than 10% reported contacting partners. Reported barriers included inaccurate or incomplete lists of partners (67.1%), poor compensation (54.1%), and insufficient time (54.1%). Facilitators chosen by respondents included another health professional assigned to follow up with PN (77.4%) and improved remuneration (74.7%). Electronic PN tools directed at patients (eg, PN slips) were favoured over resources directed at providers. CONCLUSION: Family physicians regularly manage STIs and currently take part in PN primarily through educating index cases. However, most do not feel that PN should be conducted by FPs, and most believe that FP-initiated PN would require additional personnel, remuneration, and legal guidance.


Assuntos
Busca de Comunicante , Infecções Sexualmente Transmissíveis , Colúmbia Britânica , Humanos , Médicos de Família , Parceiros Sexuais , Infecções Sexualmente Transmissíveis/diagnóstico , Infecções Sexualmente Transmissíveis/epidemiologia , Infecções Sexualmente Transmissíveis/prevenção & controle
4.
Anal Chem ; 93(49): 16289-16296, 2021 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-34842413

RESUMO

Non-targeted analysis (NTA) encompasses a rapidly evolving set of mass spectrometry techniques aimed at characterizing the chemical composition of complex samples, identifying unknown compounds, and/or classifying samples, without prior knowledge regarding the chemical content of the samples. Recent advances in NTA are the result of improved and more accessible instrumentation for data generation and analysis tools for data evaluation and interpretation. As researchers continue to develop NTA approaches in various scientific fields, there is a growing need to identify, disseminate, and adopt community-wide method reporting guidelines. In 2018, NTA researchers formed the Benchmarking and Publications for Non-Targeted Analysis Working Group (BP4NTA) to address this need. Consisting of participants from around the world and representing fields ranging from environmental science and food chemistry to 'omics and toxicology, BP4NTA provides resources addressing a variety of challenges associated with NTA. Thus far, BP4NTA group members have aimed to establish a consensus on NTA-related terms and concepts and to create consistency in reporting practices by providing resources on a public Web site, including consensus definitions, reference content, and lists of available tools. Moving forward, BP4NTA will provide a setting for NTA researchers to continue discussing emerging challenges and contribute to additional harmonization efforts.


Assuntos
Benchmarking , Humanos
5.
Adv Health Sci Educ Theory Pract ; 26(3): 771-783, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33389233

RESUMO

Spaced education is a learning strategy to improve knowledge acquisition and retention. To date, no robust evidence exists to support the utility of spaced education in the Family Medicine residency. We aimed to test whether alerts to encourage spaced education can improve clinical knowledge as measured by scores on the Canadian Family Medicine certification examination. METHOD: We conducted a cluster randomized controlled trial to empirically and pragmatically test spaced education using two versions of the Family Medicine Study Guide mobile app. 12 residency training programs in Canada agreed to participate. At six intervention sites, we consented 335 of the 654 (51%) eligible residents. Residents in the intervention group were sent alerts through the app to encourage the answering of questions linked to clinical cases. At six control sites, 299 of 586 (51%) residents consented. Residents in the control group received the same app but with no alerts. Incidence rates of case completion between trial arms were compared using repeated measures analysis. We linked residents in both trial arms to their knowledge scores on the certification examination of the College of Family Physicians of Canada. RESULTS: Over 67 weeks, there was no statistically significant difference in the completion of clinical cases by participants. The difference in mean exam scores and the associated confidence interval did not exceed the pre-defined limit of 4 percentage points. CONCLUSION: Further research is recommended before deploying spaced educational interventions in the Family Medicine residency to improve knowledge.


Assuntos
Medicina de Família e Comunidade , Internato e Residência , Canadá , Avaliação Educacional , Medicina de Família e Comunidade/educação , Humanos , Conhecimento
6.
Medicina (Kaunas) ; 57(8)2021 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-34440970

RESUMO

Background and Objectives This systematic review aims to evaluate the efficacy of Tele-Rehabilitation for decreasing pain in patients with knee osteoarthritis (OA). Materials and Methods: Following the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), three electronic databases (CINAHL, PubMed, PEDro), along with the addition of grey literature, were used to collect information. Randomized control trials (RCTs) comparing tele-rehabilitation (TR) to office-based-rehabilitation (OB) were critically appraised using the 2005 University of Oxford Standard. A total of 139 articles (PubMed = 132, CINAHL = 5, PEDro = 0, grey literature = 2) were acquired. Results: After the screening, three RCTs were included in our review. Their results show no statistically significant differences between TR and OB intervention. Furthermore, their results showed an overall reduction in pain in both groups from the baseline to the end of the study. However, each intervention's clinical efficiency was dependent on the exercise protocol itself and not on the method of delivery. There is a potential ceiling effect to the amount of therapy a patient can receive in which additional therapy would no longer lead to improved recovery. Conclusions: Our review suggests evidence that TR's efficacy is similar to that of OB for improvement of WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) score parameters in patients suffering from knee OA.


Assuntos
Osteoartrite do Joelho , Telerreabilitação , Exercício Físico , Humanos , Dor , Medição da Dor
7.
J Struct Biol ; 210(1): 107461, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-31962158

RESUMO

Electron cryo-tomography allows for high-resolution imaging of stereocilia in their native state. Because their actin filaments have a higher degree of order, we imaged stereocilia from mice lacking the actin crosslinker plastin 1 (PLS1). We found that while stereocilia actin filaments run 13 nm apart in parallel for long distances, there were gaps of significant size that were stochastically distributed throughout the actin core. Actin crosslinkers were distributed through the stereocilium, but did not occupy all possible binding sites. At stereocilia tips, protein density extended beyond actin filaments, especially on the side of the tip where a tip link is expected to anchor. Along the shaft, repeating density was observed that corresponds to actin-to-membrane connectors. In the taper region, most actin filaments terminated near the plasma membrane. The remaining filaments twisted together to make a tighter bundle than was present in the shaft region; the spacing between them decreased from 13 nm to 9 nm, and the apparent filament diameter decreased from 6.4 to 4.8 nm. Our models illustrate detailed features of distinct structural domains that are present within the stereocilium.


Assuntos
Citoesqueleto de Actina/metabolismo , Actinas/metabolismo , Tomografia com Microscopia Eletrônica/métodos , Células Ciliadas Vestibulares/metabolismo , Glicoproteínas de Membrana/metabolismo , Proteínas dos Microfilamentos/metabolismo , Citoesqueleto de Actina/genética , Animais , Glicoproteínas de Membrana/genética , Camundongos , Proteínas dos Microfilamentos/genética
8.
J Vasc Surg ; 72(5): 1534-1543, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32238310

RESUMO

OBJECTIVE: Aberrant subclavian artery (aSCA) is a rare anatomic variant whose association with other aortic branch variations and aortic pathology has yet to be established. Knowledge of such an association could be relevant to recommendations for screening and awareness as associated variations are important for operative planning. We describe the incidence of aSCA variations, its association with aortic pathology, and a proposed classification system. METHODS: The thoracic cross-sectional imaging database at Keck Hospital of the University of Southern California from 2006 to 2018 was queried for presence of aSCA. Studies were evaluated for aSCA laterality, variant anatomy, and aortic and branch vessel disease. Medical records were reviewed for associated symptoms and diagnoses. The primary outcome was association of aSCA with aortic pathology (aneurysm or dissection). Secondary outcomes were comparison of right and left aSCA, comparison between the sexes, and creation of a proposed classification system. RESULTS: Of 98,580 axial imaging studies, 810 studies (0.82%) were identified with aSCA in 312 unique patients. Right aSCA made up the majority of cases (90.1%). All aSCAs had a retroesophageal course. Kommerell's diverticulum (KD) was present in 184 (59%) with an average diameter of 1.67 cm (range, 1.2-3.3 cm). KD was more frequent (84% vs 56%; P = .0003) and larger (2.05 cm vs 1.61 cm; P < .0001) in left aSCA patients. When present, KD was more often symptomatic in left aSCA compared with right aSCA (77.4% vs 49.1%; P = .005). Dysphagia, chest pain, reflux, and asthma were all more common in left aSCA patients. KD was also more common in men (73.3% vs 50%; P < .0001) and larger in men (1.81 cm vs 1.54 cm; P < .0001) but with no difference in symptoms between sexes. Our proposed classification system based on aortic arch branching is as follows: type 1, left arch with right aSCA (59.9%); type 2, left arch with common carotid trunk and right aSCA (30.1%); type 3, right arch with left aSCA (9.6%); and type 4, right arch with common carotid trunk and left aSCA (0.3%). Subtypes describe the right vertebral artery (RVA) and left vertebral artery (LVA) origin: subclavian (s, RVA 90.1%, LVA 96.8%), carotid (c, RVA 9.6%, LVA 0.3%), or arch (a, RVA 0.3%, LVA 2.9%). Overall, 9.9% (31/312) had associated aortic pathology, although the study was underpowered to detect a difference between right aSCA and left aSCA (9.3% vs 16.1%; P = .213). Type 3 and type 4 arches more often have associated aortic pathology, KD, and symptoms. CONCLUSIONS: aSCAs are frequently symptomatic and commonly associated with aortic dissection and aneurysm. Our proposed classification scheme depicts all four aSCA arch variants and accounts for vertebral artery origin variation. These variants are common, and vertebral anatomy can differ greatly. Knowledge of these anatomic variations is critical to planning for endovascular and open repair of aortic arch pathology.


Assuntos
Variação Anatômica , Aneurisma da Aorta Torácica/epidemiologia , Dissecção Aórtica/epidemiologia , Anormalidades Cardiovasculares/complicações , Artéria Subclávia/anormalidades , Adulto , Idoso , Anatomia Transversal , Dissecção Aórtica/diagnóstico , Dissecção Aórtica/etiologia , Dissecção Aórtica/cirurgia , Aorta Torácica/diagnóstico por imagem , Aorta Torácica/patologia , Aneurisma da Aorta Torácica/diagnóstico , Aneurisma da Aorta Torácica/etiologia , Aneurisma da Aorta Torácica/cirurgia , Anormalidades Cardiovasculares/diagnóstico , Anormalidades Cardiovasculares/epidemiologia , Anormalidades Cardiovasculares/cirurgia , Procedimentos Endovasculares/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Planejamento de Assistência ao Paciente , Estudos Retrospectivos , Artéria Subclávia/diagnóstico por imagem , Artéria Subclávia/cirurgia , Tomografia Computadorizada por Raios X
9.
Sex Transm Dis ; 47(8): 525-529, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32520882

RESUMO

BACKGROUND: Expedited partner therapy (EPT) can prevent transmission of sexually transmitted infections (STIs) and reinfection of the index patient. We surveyed family physicians (FPs) in British Columbia to understand their perceptions of barriers and facilitators to EPT use and explored how perceptions varied by demographic and practice characteristics. METHODS: Survey participants were recruited through the Divisions of Family Practice, which include greater than 90% of FPs in British Columbia. Common barriers and facilitators for EPT were identified using descriptive statistics. The association between each EPT barrier and facilitator and demographic and practice characteristics were tested using χ test. RESULTS: One hundred eighty-one FPs started the survey, of which 146 (80.7%) answered 10 questions or more and were analyzed. Overall, inaccurate information about sex partners (88 [60.3%] of 146) and medicolegal concerns (87 [59.6%] of 146) were the most common barriers reported. Family physicians in nonurban settings were more likely to identify insufficient time as a barrier compared with FPs in urban settings (P < 0.01). The most common facilitators were having a health care professional for follow-up after prescribing EPT (110 [75.3%] of 146), improved remuneration (93 [63.7%] of 146), clear clinical guidelines around EPT (87/146, 59.6%), and having a legal framework (92 [63.0%] of 146). Family physicians practicing for less than 9 years (the median) were more likely to identify the latter as facilitating EPT compared with FPs practicing for 9 years or longer (P < 0.05). CONCLUSIONS: Ensuring patients have access to a health care professional for follow-up, improved remuneration, and development of clinical guidelines and a legal framework can support the implementation of EPT. Tools catered to different practice types and contexts may help increase EPT use.


Assuntos
Médicos de Família , Infecções Sexualmente Transmissíveis , Colúmbia Britânica/epidemiologia , Busca de Comunicante , Humanos , Parceiros Sexuais , Infecções Sexualmente Transmissíveis/tratamento farmacológico , Infecções Sexualmente Transmissíveis/epidemiologia , Infecções Sexualmente Transmissíveis/prevenção & controle
10.
Sensors (Basel) ; 20(2)2020 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-31963291

RESUMO

Doppler Radar Tomography (DRT) relies on spatial diversity from rotational motion of a target rather than spectral diversity from wide bandwidth signals. The slow-time k-space is a novel form of the spatial frequency space generated by the relative rotational motion of a target at a single radar frequency, which can be exploited for high-resolution target imaging by a narrowband radar with Doppler tomographic signal processing. This paper builds on a previously published work and demonstrates, with real experimental data, a unique and interesting characteristic of the slow-time k-space: it can be augmented and significantly enhance imaging resolution by signal processing. High resolution can reveal finer details in the image, providing more information to identify unknown targets detected by the radar.

11.
Bull Environ Contam Toxicol ; 105(3): 351-357, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32749513

RESUMO

Sucralose is one of the most popular artificial sweeteners worldwide. Due to its high stability, persistence and low removal efficiency in wastewater treatment plants, sucralose has been used as an indicator of wastewater intrusion into aquatic systems. However, its stability has also been a reason for discussion whether sucralose's presence in surface water could indicate a recent anthropogenic input. Caffeine and acetaminophen have been considered as tracers in human impacted aquatic ecosystems and potentially good indicators of recent anthropogenic inputs into the environment due to their short half-lives in water. Here, a novel, high throughput and sensitive method based on online SPE-LC-HRMS for the determination of caffeine, sucralose and acetaminophen was developed and validated for both fresh and seawater samples and applied to environmental water samples to evaluate the efficiency of these compounds as tracers of aquatic pollution. Caffeine and sucralose were detected in > 70% of samples, while acetaminophen was only detected in 3% of samples above the MDL, demonstrating its limited environmental applicability.


Assuntos
Acetaminofen/análise , Cafeína/análise , Monitoramento Ambiental , Sacarose/análogos & derivados , Poluentes Químicos da Água/análise , Ecossistema , Florida , Humanos , Sacarose/análise , Edulcorantes/análise , Águas Residuárias/análise , Água
12.
Opt Lett ; 44(5): 1134-1137, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30821731

RESUMO

As technology continues to advance, the development of novel sensing systems opens new possibilities for low-cost, practical biosensing applications. In this Letter, we demonstrate a localized surface plasmon resonance system that combines both wave-guiding and plasmonic resonance sensing with a single microstructured polymeric structure. Characterizing the sensor using the finite element method simulation shows, to the best of our knowledge, a record wavelength sensitivity (WS) of 111000 nm/refractive index unit (RIU), high amplitude sensitivity (AS) of 2050 RIU-1, high sensor resolution and limit of detection of 9×10-7 RIU and 8.12×10-12 RIU2/nm, respectively. Furthermore, these sensors have the capability to detect an analyte within the refractive index range of 1.33-1.43 in the visible to mid-IR, therefore being potentially suitable for applications in biomolecular and chemical analyte detection.


Assuntos
Ressonância de Plasmônio de Superfície/instrumentação , Desenho de Equipamento , Análise de Elementos Finitos , Limite de Detecção
13.
AJR Am J Roentgenol ; 213(6): W257-W263, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31573854

RESUMO

OBJECTIVE. The objective of this study was to determine if moderate to severe tricuspid regurgitation (TR) can be predicted on routine non-ECG-gated CT images of the chest with contrast agent. MATERIALS AND METHODS. Non-ECG-gated CT images of the chest in 674 people who had undergone echocardiography within 24 hours of CT were retrospectively reviewed. CT images were reviewed, and measurements of the tricuspid annular diameter were recorded. Echocardiogram reports were independently reviewed, and the presence and severity of TR was recorded. TR was graded in a multiparametric approach using a combination of qualitative, quantitative, and objective measures. TR grades of either "moderate" or "severe" were considered significant, and grades reported as "no regurgitation," "trace," "trivial," or "mild" were considered insignificant. RESULTS. The overall prevalence of significant (moderate or severe) TR was 15.0% (10.7% prevalence in men and 19.8% in women). Using ≥ 41 mm as a cut point on CT, the prediction accuracy reached an AUC of 0.92 (95% CI, 0.89-0.96). Specificity was 96.5% (95% CI, 95.0-97.9%), sensitivity was 75.7% (95% CI, 67.6-83.8%), positive predictive value was 80.2%, and negative predictive value was 95.5%. CONCLUSION. Using a cut point of ≥ 41 mm, measurement of the tricuspid valve annulus on routine CT of the chest can predict moderate to severe TR with a specificity of 96.5% and sensitivity of 75.7%. Measurements below threshold had a 95.5% negative predictive value. Tricuspid annular diameter can be measured on routine contrast-enhanced CT images of the chest, and, when above threshold, further evaluation with echocardiography should be recommended.


Assuntos
Tomografia Computadorizada por Raios X , Insuficiência da Valva Tricúspide/diagnóstico por imagem , Valva Tricúspide/diagnóstico por imagem , Idoso , Meios de Contraste , Ecocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Retrospectivos , Índice de Gravidade de Doença
14.
Opt Express ; 26(23): 30347-30361, 2018 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-30469909

RESUMO

We propose and numerically characterize the optical characteristics of a novel photonic crystal fiber (PCF) based surface plasmon resonance (SPR) sensor in the visible to near infrared (500-2000 nm) region for refractive index (RI) sensing. The finite element method (FEM) is used to design and study the influence of different geometric parameters on the sensing performance of the sensor. The chemically stable plasmonic material gold (Au) is used to produce excitation between the core and plasmonic mode. On a pure silica (SiO2) substrate, a rectangular structured core is used to facilitate the coupling strength between the core and the surface plasmon polariton (SPP) mode and thus improves the sensing performance. By tuning the geometric parameters, simulation results show a maximum wavelength sensitivity of 58000 nm/RIU (Refractive Index Unit) for the x polarization and 62000 nm/RIU for the y polarization for analyte refractive indices ranging from 1.33 to 1.43. Moreover, we characterize the amplitude sensitivity of the sensor that shows a maximum sensitivity of 1415 RIU-1 and 1293 RIU-1 for the x and y polarizations, respectively. To our knowledge, this is the highest sensitivity for an SPR in published literature, and facilitates future development of sensors for accurate and precise analyte measurement. The sensor also attains a maximum figure of merit (FOM) of 1140 and fine RI resolution of 1.6 × 10-6. Owing to strong coupling strength, high sensitivity, high FOM and improved sensing resolution, the proposed sensor is suited for real-time, inexpensive and accurate detection of biomedical and biological analytes, biomolecules, and organic chemicals.

15.
Appl Opt ; 57(10): 2426-2433, 2018 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-29714225

RESUMO

Ethanol is widely used in chemical industrial processes as well as in the food and beverage industry. Therefore, methods of detecting alcohol must be accurate, precise, and reliable. In this content, a novel Zeonex-based photonic crystal fiber (PCF) has been modeled and analyzed for ethanol detection in terahertz frequency range. A finite-element-method-based simulation of the PCF sensor shows a high relative sensitivity of 68.87% with negligible confinement loss of 7.79×10-12 cm-1 at 1 THz frequency and x-polarization mode. Moreover, the core power fraction, birefringence, effective material loss, dispersion, and numerical aperture are also determined in the terahertz frequency range. Owing to the simple fiber structure, existing fabrication methods are feasible. With the outstanding waveguiding properties, the proposed sensor can potentially be used in ethanol detection, as well as polarization-preserving applications of terahertz waves.


Assuntos
Etanol/análise , Tecnologia de Fibra Óptica/instrumentação , Espectroscopia Terahertz/instrumentação , Birrefringência , Simulação por Computador , Desenho de Equipamento , Modelos Teóricos , Radiação Terahertz , Espectroscopia Terahertz/métodos
16.
Appl Opt ; 57(4): 666-672, 2018 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-29400735

RESUMO

We report on the design, in-depth analysis, and characterization of a novel elliptical array shaped core rectangular shaped cladded photonic crystal fiber (PCF) for multichannel communication and polarization maintaining applications of terahertz waves. The asymmetrical structure of air holes in both core and cladding results in increased birefringence, while a compact geometry and different cladding air hole size makes the dispersion characteristic flat. The modal characteristics of the PCF are calculated using a finite element method. The simulated results show a near-zero dispersion flattened property of ±0.02 ps/THz/cm, high birefringence of 0.063, low effective material loss of 0.06 cm-1, and negligible confinement loss of 5.45×10-13 cm-1 in the terahertz frequency range. Additionally, the core power fraction, effective area, physical attributes, and potential fabrication possibilities of the fiber are discussed.

17.
J Comput Assist Tomogr ; 39(4): 578-83, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25783799

RESUMO

OBJECTIVE: Fat deposits in the left ventricle (LV) myocardium are uncommon and usually indicate scar due to chronic myocardial infarction. The purpose of this study was to determine the incidence of fatty lesions in the LV of patients with sarcoidosis. MATERIALS AND METHODS: Review of noncontrast computed tomographic images (2-mm thickness) in 133 patients with documented extracardiac sarcoidosis (age, 35-82 years, 55 ± 10 years, 67% female) with no history of significant coronary artery disease (clinical and coronary calcium) was performed. A control group included noncontrast computed tomographies with no coronary calcium in 133 patients with age/sex (59 ± 6 years, 73% female) similar to the sarcoid target group. Locations and morphology (linear vs bulky) of fat deposits (-30 to -180 Hounsfield units) and relevant intrathoracic findings were recorded. RESULTS: We found 35 fat deposits in 19 (14.3%) of sarcoid patients (target group: age, 59 ± 7 years, 78% female). Lesions were mainly at the LV apical level (n = 14). In the control group, 15 lesions in 13 (9.7%) patients were found. Numbers of fatty lesions in sarcoid targets were significantly higher than those in the control group (P = 0.015). The number of bulky lesions was significantly higher in sarcoid (n = 9) than in control (n = 1; P < 0.05). No significant difference was found for the rate of linear lesions. Interstitial lung disease was seen in 9 and enlarged lymph nodes in 9 of the sarcoid target group. There was no significant correlation between the severity of interstitial lung disease and the number of fatty lesions. CONCLUSIONS: Sarcoid patients demonstrate a higher chance of having LV fat deposits with a characteristic bulky morphology.


Assuntos
Tecido Adiposo/diagnóstico por imagem , Sarcoidose/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Ventrículos do Coração/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade
18.
Sensors (Basel) ; 15(12): 30856-69, 2015 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-26670235

RESUMO

Subspace-based high-resolution direction of arrival (DOA) estimation significantly deteriorates under array manifold perturbation and rank deficiency of the covariance matrix due to mutual coupling and multipath propagation, respectively. In this correspondence, the unknown mutual coupling can be circumvented by the proposed method without any passive or active calibration process, and the DOA of the coherent signals can be accurately estimated accordingly. With a newly constructed matrix, the deficient rank can be restored, and the effective array aperture can be extended compared with conventional spatial smoothing. The proposed method achieves a good robustness and DOA estimation accuracy with unknown mutual coupling. The simulation results demonstrate the validity and efficiency of the proposed method.

19.
Nature ; 455(7216): 1069-75, 2008 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-18948947

RESUMO

Determining the genetic basis of cancer requires comprehensive analyses of large collections of histopathologically well-classified primary tumours. Here we report the results of a collaborative study to discover somatic mutations in 188 human lung adenocarcinomas. DNA sequencing of 623 genes with known or potential relationships to cancer revealed more than 1,000 somatic mutations across the samples. Our analysis identified 26 genes that are mutated at significantly high frequencies and thus are probably involved in carcinogenesis. The frequently mutated genes include tyrosine kinases, among them the EGFR homologue ERBB4; multiple ephrin receptor genes, notably EPHA3; vascular endothelial growth factor receptor KDR; and NTRK genes. These data provide evidence of somatic mutations in primary lung adenocarcinoma for several tumour suppressor genes involved in other cancers--including NF1, APC, RB1 and ATM--and for sequence changes in PTPRD as well as the frequently deleted gene LRP1B. The observed mutational profiles correlate with clinical features, smoking status and DNA repair defects. These results are reinforced by data integration including single nucleotide polymorphism array and gene expression array. Our findings shed further light on several important signalling pathways involved in lung adenocarcinoma, and suggest new molecular targets for treatment.


Assuntos
Adenocarcinoma Bronquioloalveolar/genética , Neoplasias Pulmonares/genética , Mutação/genética , Feminino , Dosagem de Genes , Regulação Neoplásica da Expressão Gênica , Genes Supressores de Tumor , Humanos , Masculino , Proto-Oncogenes/genética
20.
J Invasive Cardiol ; 2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38814903

RESUMO

A 57-year-old woman with good past health was admitted to the accident and emergency department at an outside hospital for sudden onset chest pain. Electrocardiogram revealed ST-segment elevation at inferior leads.

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