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1.
Nanomaterials (Basel) ; 13(21)2023 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-37947693

RESUMO

The ability to manipulate spins in magnetic materials is essential in designing spintronics devices. One method for magnetic switching is through strain. In VO2 on TiO2 thin films, while VO2 remains rutile across the metal-insulator transition, the in-plane lattice area expands going from a low-temperature insulating phase to a high-temperature conducting phase. In a VO2/TbFeCo bilayer, the expansion of the VO2 lattice area exerts tension on the amorphous TbFeCo layer. Through the strain effect, magnetic properties, including the magnetic anisotropy and magnetization, of TbFeCo can be changed. In this work, the changes in magnetic properties of TbFeCo on VO2/TiO2(011) are demonstrated using anomalous Hall effect measurements. Across the metal-insulator transition, TbFeCo loses perpendicular magnetic anisotropy, and the magnetization in TbFeCo turns from out-of-plane to in-plane. Using atomistic simulations, we confirm these tunable magnetic properties originating from the metal-insulator transition of VO2. This study provides the groundwork for controlling magnetic properties through a phase transition.

2.
Rev Sci Instrum ; 93(8): 083516, 2022 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-36050109

RESUMO

The hardened single line of sight camera has been recently characterized in preparation for its deployment on the National Ignition Facility. The latest creation based on the pulse-dilation technology leads to many new features and improvements over the previous-generation cameras to provide better quality measurements of inertial confinement fusion experiments, including during high neutron yield implosions. Here, we present the characterization data that illustrate the main performance features of this instrument, such as extended dynamic range and adjustable internal magnification, leading to improved spatial resolution.

3.
Int J Equity Health ; 20(1): 121, 2021 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-34001154

RESUMO

BACKGROUND: Poor access to healthcare facilities and consequently nutrition counseling services hinders the uptake of recommended infant and young child feeding (IYCF) practices. To address these barriers and improve IYCF practices, Alive & Thrive (A&T) initiated community support groups in remote villages across nine provinces in Vietnam. OBJECTIVE: This study examines the effectiveness of the support group model and related project costs for reaching underserved areas to improve IYCF practices. METHODS: To evaluate the model's implementation and project costs, we reviewed implementation guidelines, expenditure and coverage reports, monitoring data, and budgets for the nine provinces. To evaluate the model's effectiveness, we used a 3-stage sampling method to conduct a cross-sectional survey from April to May 2014 in three provinces entailing interviewing mothers of children aged 0-23 months in communes with (intervention; n = 551) and without support groups (comparison; n = 559). FINDINGS: Coverage: From November 2011 to November 2014, in partnership with the government, A&T supported training for 1513 facilitators and the establishing 801 IYCF support groups in 267 villages across nine provinces. During this period, facilitators provided ~ 166,000 meeting/support contacts with ~ 33,000 pregnant women and mothers with children aged 0-23 months in intervention villages. COSTS: The average project costs for supporting the meetings, compensating village collaborators, and providing supportive supervision through staff in commune health stations were USD 5 per client and USD 1 per contact. After adding expenditures for training, supportive supervision, and additional administrative costs at central and provincial levels, the average project cost was USD 15 per client and USD 3 per contact. Effectiveness: Survey participants in intervention and comparison communes had similar maternal, child, and household characteristics. Multiple logistic regression models showed that living in intervention communes was associated with higher odds of early initiation of breastfeeding (OR: 1.7; 95% CI: 1.1, 2.7), exclusive breastfeeding from 0 to 5 months (OR: 12.5; 95% CI: 6.7, 23.4), no bottle feeding (OR: 2.69; 95% CI: 1.82, 3.99), and minimum acceptable diet (OR: 1.51; 95% CI: 0.98, 2.33) compared to those living in comparison communes. CONCLUSION: The IYCF support group model was effective in reaching populations residing in remote areas and likely contributed to improved IYCF practices. The study suggests that the model could be scaled up to promote equity in breastfeeding support.


Assuntos
Aleitamento Materno , Serviços de Saúde Comunitária , Comportamento Alimentar , Mães , População Rural , Adulto , Aleitamento Materno/psicologia , Aleitamento Materno/estatística & dados numéricos , Serviços de Saúde Comunitária/economia , Serviços de Saúde Comunitária/organização & administração , Análise Custo-Benefício , Estudos Transversais , Comportamento Alimentar/psicologia , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Modelos Organizacionais , Mães/psicologia , Mães/estatística & dados numéricos , População Rural/estatística & dados numéricos , Grupos de Autoajuda , Vietnã
4.
Hormones (Athens) ; 20(3): 499-506, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32405929

RESUMO

BACKGROUND: The success of minimally invasive parathyroidectomy (MIP) relies on accurate localization of the abnormal parathyroid glands. Concordant findings on ultrasound (US) and 99mTc-scintigraphy (sestamibi) are currently considered the 'gold standard'. Computed tomography (CT) has also recently been used in preoperative planning. We sought to assess the accuracy of CT for localization of abnormal parathyroid glands in such patients. METHODS: An audit of 75 patients with primary hyperparathyroidism (PHPT) who underwent neck US and CT between 2017 and 2019 at our center as their first-line imaging. RESULTS: All 75 patients underwent US and CT and 54 (72.0%) also had sestamibi. CT alone identified a potential target in all patients, of which the location was correct in 63 (84.0%). The overall combined sensitivity of US and CT was 88% (95% CI 78-94) and was higher than the combined sensitivity of US and sestamibi (65% [95% CI 53-76]; p < 0.001). Twenty-one patients (28.0%) had an ectopic gland, and the sensitivity of US and CT was 86% (95% CI 64-96) versus US and sestamibi (57% [95% CI 34-77]; p = 0.016). For adenomas < 1.0 g (n = 36; 48%), the accuracy of CT was 81% (95% CI 64-91) compared with 62% (95% CI 44-77) for US and sestamibi (p = 0.04). The correct preoperative diagnosis of multiglandular disease (n = 9; 12%) seemed to be the most difficult, with similar accuracy for US and sestamibi (40% [95% CI 14-73]) and US and CT (50% [95% CI 20-80]) (p > 0.99). CONCLUSION: The combination of US and CT was able to correctly identify the location of the abnormal parathyroid in 88% of patients and, in comparison with US and sestamibi, had better diagnostic accuracy, especially for smaller and ectopic adenomas. This finding suggests that US and CT could be considered as a first-line imaging modality in patients with PHPT considered for MIP.


Assuntos
Adenoma , Hiperparatireoidismo Primário , Adenoma/diagnóstico por imagem , Humanos , Hiperparatireoidismo Primário/diagnóstico por imagem , Glândulas Paratireoides/diagnóstico por imagem , Compostos Radiofarmacêuticos , Tecnécio Tc 99m Sestamibi , Tomografia Computadorizada por Raios X , Ultrassonografia
6.
ACS Appl Mater Interfaces ; 12(12): 14154-14164, 2020 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-32125816

RESUMO

Polymer dielectrics with low-loss and high-temperature tolerance are extremely desirable as electrical energy storage materials for advanced electronics and electrical power applications. They can allow fast switching rates during power conversion and therefore achieve high power densities without thermal issues. Here, we explore polypropylene (PP), the state of the art dielectric polymer, and present an innovative approach to substantially improve the thermal stability and concurrently reduce the dielectric loss of PP. In particular, cross-linkable antioxidant groups, hindered phenol (HP), are incorporated into PP via well-controlled chemical synthesis. The grafted HP can simultaneously serve as radical scavenger and cross-linker, thereby constraining thermally decomposed radicals and charge transport in the synthesized PP-HP copolymer. As a result, the upper-temperature limit of PP-HP is greatly extended to 190 °C and the electrical loss is even gradually reduced upon thermal annealing. The copolymer after heating under 190 °C exhibits better dielectric properties than the PP without any thermal treatment. The experimental results indicate that the PP-HP copolymers are promising materials for high-temperature, low-loss, and high-voltage dielectric applications.

7.
Sci Rep ; 10(1): 159, 2020 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-31932599

RESUMO

Enterovirus-A71 (EV-A71) is a common cause of hand-foot-and-mouth disease (HFMD) and, rarely, causes severe neurological disease. This study aimed to elucidate the epidemiological and genetic characteristics and virulence of EV-A71 strains isolated from children diagnosed with HFMD. Rectal and throat swabs were collected from 488 children with HFMD in Hanoi, Vietnam, in 2015-2016. From 391 EV-positive patients, 15 EVs, including coxsackievirus A6 (CV-A6; 47.1%) and EV-A71 (32.5%, n = 127), were identified. Of the 127 EV-A71 strains, 117 (92.1%) were the B5 subgenotype and 10 (7.9%) were the C4 subgenotype. A whole-genome analysis of EV-A71 strains showed that seven of the eight C4a strains isolated in 2016 formed a new lineage, including two possible recombinants between EV-A71 C4 and CV-A8. The proportion of inpatients among C4-infected children was higher than among B5-infected children (80.0% vs. 27.4%; P = 0.002). The virulence of EV-A71 strains was examined in human scavenger receptor class B2 (hSCARB2)-transgenic mice, and EV-A71 C4 strains exhibited higher mortality than B5 strains (80.0% vs. 30.0%, P = 0.0001). Thus, a new EV-A71 C4a-lineage, including two possible recombinants between EV-A71 C4 and CV-A8, appeared in 2016 in Vietnam. The EV-A71 C4 subgenotype may be more virulent than the B5 subgenotype.


Assuntos
Enterovirus/classificação , Enterovirus/isolamento & purificação , Doença de Mão, Pé e Boca/epidemiologia , Doença de Mão, Pé e Boca/mortalidade , Proteínas de Membrana Lisossomal/fisiologia , Receptores Depuradores/fisiologia , Replicação Viral , Animais , Criança , Pré-Escolar , Surtos de Doenças , Enterovirus/genética , Feminino , Doença de Mão, Pé e Boca/virologia , Humanos , Lactente , Masculino , Camundongos , Camundongos Transgênicos , Filogenia , Sorogrupo , Taxa de Sobrevida , Fatores de Tempo , Vietnã/epidemiologia
9.
Phys Rev Lett ; 122(11): 113602, 2019 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-30951338

RESUMO

An outstanding goal in quantum optics and scalable photonic quantum technology is to develop a source that each time emits one and only one entangled photon pair with simultaneously high entanglement fidelity, extraction efficiency, and photon indistinguishability. By coherent two-photon excitation of a single InGaAs quantum dot coupled to a circular Bragg grating bull's-eye cavity with a broadband high Purcell factor of up to 11.3, we generate entangled photon pairs with a state fidelity of 0.90(1), pair generation rate of 0.59(1), pair extraction efficiency of 0.62(6), and photon indistinguishability of 0.90(1) simultaneously. Our work will open up many applications in high-efficiency multiphoton experiments and solid-state quantum repeaters.

10.
Opt Express ; 27(5): 6832-6841, 2019 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-30876260

RESUMO

We report the transfer printing of GaN-based microscale vertical-type light-emitting diodes (µ-VLEDs) using a functional layer and a biomimetic stamp. An oxide-based functional layer is inserted onto the structure of a µ-VLED and used to separate the chip from the µ-VLED wafer by absorbing the pulse of a UV pulse laser during pick-up of the transfer printing process. Polydimethylsiloxane (PDMS)-based biomimetic stamps have been fabricated to mimic the gecko lizard cilia for improved adhesion and repeatability. The biomimetic stamp has an adhesion force of 25.6 N/cm2, which is 12 times the adhesion of a flat stamp; an adhesion force of 10 N/cm2 or more was maintained after 100,000 repeated adhesion tests. A flexible 10 × 10 prototype array on a polyimide substrate was fabricated, and its bending test results indicated that the strain effect on the forward voltage and the output power was less than 1%. The stable bending test results of the prototype indicate that µ-VLEDs using biomimetic stamps allow the necessary stability for practical transfer printing.

11.
Ultrasound Obstet Gynecol ; 53(4): 541-545, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30246270

RESUMO

OBJECTIVE: Ethnicity has been suggested to be a significant risk factor for pelvic organ prolapse (POP); yet, pelvic organ descent in different ethnic groups, especially in Asian populations, is not well studied. The aim of this study was to compare prolapse stages, pelvic organ descent and hiatal dimensions between East Asian and Caucasian women presenting with symptoms of POP. METHODS: This was a prospective observational study of East Asian and Caucasian women presenting with symptoms of POP to a tertiary urogynecology clinic in, respectively, Hong Kong and Sydney. Demographic data, prolapse symptoms and prolapse stage were assessed. Physical examination was performed using the pelvic organ prolapse quantification (POP-Q) system. All women underwent transperineal ultrasound using Voluson systems. Offline analysis of four-dimensional ultrasound volume data was performed at a later date, by one operator blinded to all clinical data, to ascertain pelvic organ descent and hiatal dimensions on Valsalva maneuver. Levator muscle avulsion was assessed in volumes obtained on pelvic floor muscle contraction. Multiple logistic regression analysis was performed to assess factors associated with prolapse on clinical and ultrasound examinations. RESULTS: A total of 225 East Asian women were included between July 2012 and February 2014 from the Hong Kong clinic and 206 Caucasian women between January 2015 and July 2016 from the Sydney clinic. There was no significant difference in the overall staging of prolapse. However, in East Asian women, compared with Caucasians, apical compartment prolapse was more common (99.6% vs 71.8%, P < 0.001) and posterior compartment prolapse less common (16.9% vs 48.5%, P < 0.001) on POP-Q examination. On Valsalva maneuver, the position of the uterus was lower in East Asian than in Caucasian women (-11.3 vs 1.35 mm, P < 0.001), while the rectal ampulla position was lower in Caucasians than in East Asians (-10.6 vs - 4.1 mm, P < 0.001). On multiple regression analysis, Caucasian ethnicity was a significant factor for lower risk of apical compartment prolapse on clinical assessment (odds ratio (OR), 0.01; P < 0.001) and on ultrasound (OR, 0.13; P < 0.001), and for a higher risk of posterior compartment prolapse on clinical assessment (OR, 4.36; P < 0.001) and of true rectocele on ultrasound (OR, 8.14; P < 0.001). CONCLUSIONS: East Asian women present more commonly with uterine prolapse while Caucasians show more often posterior compartment prolapse. Ethnicity was a significant predictor of type of prolapse on multivariate analysis. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.


Assuntos
Prolapso de Órgão Pélvico/etnologia , Adulto , Idoso , Povo Asiático/estatística & dados numéricos , Feminino , Humanos , Modelos Logísticos , Pessoa de Meia-Idade , Prolapso de Órgão Pélvico/classificação , Prolapso de Órgão Pélvico/diagnóstico por imagem , Estudos Prospectivos , Retocele/diagnóstico por imagem , Fatores de Risco , Método Simples-Cego , Ultrassonografia , Útero/diagnóstico por imagem , População Branca/estatística & dados numéricos
12.
Osteoporos Int ; 30(2): 519-523, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30171299

RESUMO

Denosumab, a novel agent that inhibits osteoclasts, reduces the risk of fracture in patients with osteoporosis. However, worsening of hypophosphatemia and other symptoms may be induced by denosumab in patients with pre-existing hypophosphatemic osteomalacia. A 58-year-old man with hepatitis B presented with diffuse bone pain and muscle weakness. Denosumab was prescribed by the orthopedist according to documented low bone mass and spine compression fracture. After administering denosumab, the patient's bone pain worsened, and he later developed a right tibia stress fracture. His condition was diagnosed as adult-onset hypophosphatemic osteomalacia complicated by multiple bone fractures, which resulted from Fanconi syndrome with proximal tubulopathy due to tenofovir disoproxil fumarate (TDF) treatment for his hepatitis B. Denosumab use leads to aggressive hypophosphatemic osteomalacia and the complication of stress fractures, because of its effects on bone resorption. Physicians should be aware that in patients with chronic hepatitis B monoinfection who are administered TDF therapy, bone pain or fracture is possible but preventable by timely monitoring of serum phosphate levels. Denosumab should not be used in patients with untreated osteomalacia or vitamin D deficiency, as it may lead not only to hypocalcemia but also to hypophosphatemia in these patients.


Assuntos
Conservadores da Densidade Óssea/efeitos adversos , Denosumab/efeitos adversos , Síndrome de Fanconi/induzido quimicamente , Hipofosfatemia/induzido quimicamente , Osteomalacia/tratamento farmacológico , Antivirais/efeitos adversos , Antivirais/uso terapêutico , Conservadores da Densidade Óssea/uso terapêutico , Denosumab/uso terapêutico , Síndrome de Fanconi/complicações , Fraturas de Estresse/diagnóstico por imagem , Fraturas de Estresse/etiologia , Hepatite B Crônica/tratamento farmacológico , Humanos , Masculino , Pessoa de Meia-Idade , Osteomalacia/diagnóstico por imagem , Radiografia , Cintilografia , Tenofovir/efeitos adversos , Tenofovir/uso terapêutico , Fraturas da Tíbia/diagnóstico por imagem , Fraturas da Tíbia/etiologia , Tomografia Computadorizada por Raios X
13.
Proc Inst Mech Eng H ; 233(2): 181-192, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30518308

RESUMO

Transtibial prosthetic sockets can be fabricated either by the conventional way, which involve using plaster of Paris bandages for casting. This will include modifications through hand, scanning and digital imaging of software. The aim of this study is to determine the circumferential profiles and conduct a volumetric analysis of a conventional socket that has fabrication using biosculptor technology. In doing this, a male transtibial amputee, age 28 years old with stable health condition was studied, where circumferential measurements were taken at intervals of 1 cm from the distal end of the residual limb to the medial tibial plateau level. Furthermore, the interior volume of both sockets and residuum were determined directly using water displacement method. A comparative value for the calculation of volume was also carried out using engineering mathematical equations. From these measurements, a total surface bearing transtibial sockets was fabricated to compare the changes of circumferential values of both sockets. The finding shows a percentage of the difference between the volume of the residual limb and conventional sockets to be 6.09%, whereas the biosculptor fabrication socket was 7.84% using the water displacement method. A comparison of circumferential profiles and volumetric analysis findings on the contrary showed that socket fabricated using the biosculptor technology is interchangeable with the conventional socket with more advantages, where biosculptor technology produces cheaper sockets and faster process with digital function in the procedure, unlike the conventional manual technique.


Assuntos
Desenho de Prótese/métodos , Tíbia , Humanos
14.
Rev Sci Instrum ; 89(10): 10G123, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30399697

RESUMO

A new generation of fast-gated x-ray framing cameras have been developed that are capable of capturing multiple frames along a single line-of-sight with 30 ps temporal resolution. The instruments are constructed by integrating pulse-dilation electron imaging with burst mode hybrid-complimentary metal-oxide-semiconductor sensors. Two such instruments have been developed, characterized, and fielded at the National Ignition Facility and the OMEGA laser. These instruments are particularly suited for advanced x-ray imaging applications in Inertial Confinement Fusion and High energy density experiments. Here, we discuss the system architecture and the techniques required for tuning the instruments to achieve optimal performance. Characterization results are also presented along with planned future improvements to the design.

15.
Rev Sci Instrum ; 89(10): 10G117, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30399700

RESUMO

The single-line-of-sight, time-resolved x-ray imager (SLOS-TRXI) on OMEGA is one of a new generation of fast-gated x-ray cameras comprising an electron pulse-dilation imager and a nanosecond-gated, burst-mode, hybrid complementary metal-oxide semiconductor sensor. SLOS-TRXI images the core of imploded cryogenic deuterium-tritium shells in inertial confinement fusion experiments in the ∼4- to 9-keV photon energy range with a pinhole imager onto a photocathode. The diagnostic is mounted on a fixed port almost perpendicular to a 16-channel, framing-camera-based, time-resolved Kirkpatrick-Baez microscope, providing a second time-gated line of sight for hot-spot imaging on OMEGA. SLOS-TRXI achieves ∼40-ps temporal resolution and better than 10-µm spatial resolution. Shots with neutron yields of up to 1 × 1014 were taken without observed neutron-induced background signal. The implosion images from SLOS-TRXI show the evolution of the stagnating core.

16.
Rev Sci Instrum ; 89(10): 10G125, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30399712

RESUMO

Crystal x-ray imaging is frequently used in inertial confinement fusion and laser-plasma interaction applications as it has advantages compared to pinhole imaging, such as higher signal throughput, better achievable spatial resolution, and chromatic selection. However, currently used x-ray detectors are only able to obtain a single time resolved image per crystal. The dilation aided single-line-of-sight x-ray camera described here was designed for the National Ignition Facility (NIF) and combines two recent diagnostic developments, the pulse dilation principle used in the dilation x-ray imager and a ns-scale multi-frame camera that uses a hold and readout circuit for each pixel. This enables multiple images to be taken from a single-line-of-sight with high spatial and temporal resolution. At the moment, the instrument can record two single-line-of-sight images with spatial and temporal resolution of 35 µm and down to 35 ps, respectively, with a planned upgrade doubling the number of images to four. Here we present the dilation aided single-line-of-sight camera for the NIF, including the x-ray characterization measurements obtained at the COMET laser, as well as the results from the initial timing shot on the NIF.

17.
Bone Joint J ; 100-B(10): 1359-1363, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30295529

RESUMO

AIMS: This study reports the outcomes of a technique of soft-tissue coverage and Chopart amputation for severe crush injuries of the forefoot. PATIENTS AND METHODS: Between January 2012 to December 2016, 12 patients (nine male; three female, mean age 38.58 years; 26 to 55) with severe foot crush injury underwent treatment in our institute. All patients were followed-up for at least one year. Their medical records, imaging, visual analogue scale score, walking ability, complications, and functional outcomes one year postoperatively based on the American Orthopedic Foot and Ankle Society (AOFAS) and 36-Item Short-Form Health Survey (SF-36) scores were reviewed. RESULTS: The mean length of follow-up was 18.6 months (13 to 28). Two patients had a local infection, flap necrosis was seen in one patient, and one patient experienced a skin graft wound healing delay. Of the 12 patients, one had persistent infection and eventually required below-knee amputation, but pain-free walking was achieved in all the other patients. The mean one-year postoperative AOFAS and SF-36 scores were 75.6 (68 to 80) and 82 (74 to 88), respectively. CONCLUSION: Although our sample size was small, we believe that this treatment method may be a valuable alternative for treating severe foot crush injuries. Cite this article: Bone Joint J 2018;100-B:1359-63.


Assuntos
Amputação Cirúrgica/métodos , Articulação do Tornozelo/cirurgia , Artrodese/métodos , Traumatismos do Pé/cirurgia , Retalhos de Tecido Biológico/transplante , Adulto , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Procedimentos de Cirurgia Plástica , Estudos Retrospectivos , Resultado do Tratamento
18.
Analyst ; 143(22): 5589-5596, 2018 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-30320850

RESUMO

In situ measurement of hydrocarbons in water is critical for assuring the safety and quality of drinking water and in environmental remediation activities such as the cleanup of oil spills. Thus, effective detection methods of hydrocarbons in aqueous environments are important and several methods have been used for this type of sensing, including spectroscopic techniques, fiber optic sensors, and chromatography. However, under aqueous conditions, small amounts of hydrocarbons are difficult to detect due to their low concentration in water and robust sensing of these types of compounds in an aqueous environment remains a challenging analytical task. Hydrophobic polymer coatings have been widely used to concentrate hydrocarbons for attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) detection at the surface of an ATR crystal by preventing water molecules from penetrating into the polymer coating while absorbing hydrocarbons. However, in typical coating designs only thin films (<5 µm) can be applied onto the ATR sensor due to the decrease in detection limit and sensitivity to hydrocarbons with increasing film thickness. This paper demonstrates that a semi-crystalline linear low-density polyethylene (LLDPE) polymer coating with thicker thickness (40 µm) can be applied effectively for in situ ATR-FTIR detection of hydrocarbons in aqueous solution. The ATR signal is enhanced by the polymer coating which swells in response to the hydrocarbons and prevents water accumulation at the IR detection interface. Coating the ATR element with a LLDPE film (crystallinity = 12%) reduced the detection time for various hydrocarbons, including toluene, benzene and chloroform. The detection limits and kinetics of the ATR-FTIR detection were not significantly altered when the thickness of the LLDPE coating was increased to improve its mechanical properties which represents a significant improvement from coatings published in the literature. The LLDPE coating described in this research has the potential to be applied as a sensor coating for rapid detection of hydrocarbon-based substances or non-polar biomolecules in aqueous environments.

19.
Hong Kong Med J ; 24(5): 492-500, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30232267

RESUMO

With the ageing of the global population, China is projected to be impacted significantly by the rising number of patients with Alzheimer's disease (AD). A cure for AD is not yet available, so society should be prepared for an increasing AD-related burden. In this review, we examine this impending problem and provide overviews on (a) the magnitude of the problem of AD in Hong Kong/China in the near future; (b) the genetic and lifestyle risk factors that contribute to AD; (c) current diagnostic approaches and the potential of newly discovered genetic biomarkers for early detection; (d) medications, non-pharmacological interventions, and possible preventive measures; and (e) the need for social and psychological care from the community. In Hong Kong, primary care and AD-related support for at-risk individuals, patients, and caregivers are inadequate. A joint effort from the medical community, government, universities, non-governmental organisations/charities, and industry should initiate the development of a long-term programme for AD. Finally, we outline recommendations for the relevant parties to consider.


Assuntos
Doença de Alzheimer/epidemiologia , Diagnóstico Precoce , Idoso , Doença de Alzheimer/etiologia , Doença de Alzheimer/prevenção & controle , Povo Asiático , China/epidemiologia , Feminino , Serviços de Saúde para Idosos , Hong Kong/epidemiologia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco
20.
Hong Kong Med J ; 24(4): 369-377, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-30065122

RESUMO

INTRODUCTION: Mesh-related complications from reconstructive surgery for pelvic organ prolapse are of international concern. The present study aimed to review the incidence, management, and surgical outcomes of mesh-related complications in a Chinese population compared with existing studies involving Western populations. METHODS: This was an analysis of a prospectively collected cohort. Laparoscopic sacrocolpopexy, laparoscopic hystercolposacropexy, or transvaginal mesh surgery were offered with or without concomitant vaginal hysterectomy or continence surgery. Patients were followed up and mesh-related complications were noted. RESULTS: Overall, 276 Chinese women who received mesh surgery were included for data analysis. There were 22 mesh-related complications found during a mean follow-up period of 40 months. Mesh exposure accounted for 20 these complications; significantly more occurred after transvaginal than after abdominal mesh surgery (16 vs 4; P=0.01). Median duration from primary operation to the time of mesh exposure detection was 12 months (interquartile range=4.8-32.8 months). Ten patients required surgical excisions of exposed mesh. The re-operation rate after mesh complications was 6.7% (9/134) for transvaginal mesh surgery and 1.4% (2/142) for laparoscopic sacrocolpopexy (P=0.03). All excisions were performed transvaginally and 95% remained well after surgery. Occurrence of mesh exposure was higher in transvaginal mesh surgery (adjusted odds ratio=6.1; P=0.008), in sexually active patients (adjusted odds ratio=5.4; P=0.002), and in obese patients (adjusted odds ratio=3.7; P=0.046). Over 90% were satisfied with the outcome, regardless of mesh complications. CONCLUSIONS: The rates of mesh exposure and re-operation were consistent with those reported in the literature, suggesting no significant differences in outcome between Chinese and Western patients for this type of surgery.


Assuntos
Prolapso de Órgão Pélvico/cirurgia , Procedimentos de Cirurgia Plástica/efeitos adversos , Complicações Pós-Operatórias/epidemiologia , Reoperação/estatística & dados numéricos , Telas Cirúrgicas/efeitos adversos , Idoso , Feminino , Hong Kong/epidemiologia , Humanos , Modelos Logísticos , Pessoa de Meia-Idade , Estudos Prospectivos
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