Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 38
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Pediatr Allergy Immunol ; 34(5): e13953, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37232280

RESUMO

BACKGROUND: Studies on the relationship between childhood allergic disease and health-related quality of life (HRQOL) have mostly been confined to a single allergic condition. Therefore, a composite allergic score (CAS) was derived to assess the accumulated effect of eczema, asthma, and allergic rhinitis on HRQOL in Hong Kong schoolchildren. METHODS: Parents of grade one/two or grade eight/nine schoolchildren completed a questionnaire assessing the prevalence and severity of eczema (POEM), asthma (C-ACT/ACT), and allergic rhinitis (VAS) and schoolchildren's HRQOL (PedsQL). Three rounds of recruitment were conducted. A total of 19 primary and 25 secondary schools agreed to participate. RESULTS: Data from 1140 caregivers of grade one/two schoolchildren and 1048 grade eight/nine schoolchildren were imputed and analyzed. The proportion of female respondents were lower in grade one/two (37.7%) but higher in grade eight/nine (57.3%). 63.8% of grade one/two and 58.1% of grade eight/nine schoolchildren reported having at least one allergic disease. In general, greater disease severity was significantly associated with lower HRQOL. After controlling for age, gender, and allergic comorbidity in hierarchical regressions, CAS significantly predicted all HRQOL outcomes in both grade one/two and grade eight/nine schoolchildren. Female grade eight/nine schoolchildren reported lower HRQOL outcomes. CONCLUSION: Composite allergic score may be a practical tool to evaluate allergic comorbidity and the effectiveness of treatments targeting common pathological mechanisms of allergic diseases. Non-pharmaceutical approaches should be considered, especially for patients with more than one allergic disease and greater severity.


Assuntos
Asma , Eczema , Rinite Alérgica , Humanos , Feminino , Criança , Hong Kong/epidemiologia , Qualidade de Vida , Asma/epidemiologia , Asma/complicações , Eczema/epidemiologia , Rinite Alérgica/epidemiologia , Rinite Alérgica/complicações , Inquéritos e Questionários , Prevalência
2.
Int J Mol Sci ; 24(19)2023 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-37834133

RESUMO

Hydrophilicity/hydrophobicity-or wettability-is a key surface characterization metric for titanium used in dental and orthopedic implants. However, the effects of hydrophilicity/hydrophobicity on biological capability remain uncertain, and the relationships between surface wettability and other surface parameters, such as topography and chemistry, are poorly understood. The objective of this study was to identify determinants of surface wettability of titanium and establish the reliability and validity of the assessment. Wettability was evaluated as the contact angle of ddH2O. The age of titanium specimens significantly affected the contact angle, with acid-etched, microrough titanium surfaces becoming superhydrophilic immediately after surface processing, hydrophobic after 7 days, and hydrorepellent after 90 days. Similar age-related loss of hydrophilicity was also confirmed on sandblasted supra-micron rough surfaces so, regardless of surface topography, titanium surfaces eventually become hydrophobic or hydrorepellent with time. On age-standardized titanium, surface roughness increased the contact angle and hydrophobicity. UV treatment of titanium regenerated the superhydrophilicity regardless of age or surface roughness, with rougher surfaces becoming more superhydrophilic than machined surfaces after UV treatment. Conditioning titanium surfaces by autoclaving increased the hydrophobicity of already-hydrophobic surfaces, whereas conditioning with 70% alcohol and hydrating with water or saline attenuated pre-existing hydrophobicity. Conversely, when titanium surfaces were superhydrophilic like UV-treated ones, autoclaving and alcohol cleaning turned the surfaces hydrorepellent and hydrophobic, respectively. UV treatment recovered hydrophilicity without exception. In conclusion, surface roughness accentuates existing wettability and can either increase or decrease the contact angle. Titanium must be age-standardized when evaluating surface wettability. Surface conditioning techniques significantly but unpredictably affect existing wettability. These implied that titanium wettability is significantly influenced by the hydrocarbon pellicle and other contaminants inevitably accumulated. UV treatment may be an effective strategy to standardize wettability by making all titanium surfaces superhydrophilic, thereby allowing the characterization of individual surface topography and chemistry parameters in future studies.


Assuntos
Implantes Dentários , Titânio , Molhabilidade , Titânio/química , Propriedades de Superfície , Reprodutibilidade dos Testes , Interações Hidrofóbicas e Hidrofílicas , Microscopia Eletrônica de Varredura
3.
Int J Mol Sci ; 25(1)2023 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-38203293

RESUMO

The development of healthy peri-implant soft tissues is critical to achieving the esthetic and biological success of implant restorations throughout all stages of healing and tissue maturation, starting with provisionalization. The purpose of this study was to investigate the effects of eight different implant provisional materials on human gingival fibroblasts at various stages of cell settlement by examining initial cell attachment, growth, and function. Eight different specimens-bis-acrylic 1 and 2, flowable and bulk-fill composites, self-curing acrylic 1 and 2, milled acrylic, and titanium (Ti) alloy as a control-were fabricated in rectangular plates (n = 3). The condition of human gingival fibroblasts was divided into two groups: those in direct contact with test materials (contact experiment) and those in close proximity to test materials (proximity experiment). The proximity experiment was further divided into three phases: pre-settlement, early settlement, and late settlement. A cell culture insert containing each test plate was placed into a well where the cells were pre-cultured. The number of attached cells, cell proliferation, resistance to detachment, and collagen production were evaluated. In the contact experiment, bis-acrylics and composites showed detrimental effects on cells. The number of cells attached to milled acrylic and self-curing acrylic was relatively high, being approximately 70% and 20-30%, respectively, of that on Ti alloy. There was a significant difference between self-curing acrylic 1 and 2, even with the same curing modality. The cell retention ability also varied considerably among the materials. Although the detrimental effects were mitigated in the proximity experiment compared to the contact experiment, adverse effects on cell growth and collagen production remained significant during all phases of cell settlement for bis-acrylics and flowable composite. Specifically, the early settlement phase was not sufficient to significantly mitigate the material cytotoxicity. The flowable composite was consistently more cytotoxic than the bulk-fill composite. The harmful effects of the provisional materials on gingival fibroblasts vary considerably depending on the curing modality and compositions. Pre-settlement of cells mitigated the harmful effects, implying the susceptibility to material toxicity varies depending on the progress of wound healing and tissue condition. However, cell pre-settlement was not sufficient to fully restore the fibroblastic function to the normal level. Particularly, the adverse effects of bis-acrylics and flowable composite remained significant. Milled and self-curing acrylic exhibited excellent and acceptable biocompatibility, respectively, compared to other materials.


Assuntos
Materiais Dentários , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Humanos , Projetos de Pesquisa , Ligas , Fibroblastos , Colágeno
4.
Allergol Int ; 72(3): 458-465, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37032258

RESUMO

BACKGROUND: The current diagnostics of fish allergy lack sufficient accuracy such that more reliable tests such as component-resolved diagnosis (CRD) are urgently needed. This study aimed at identifying fish allergens of salmon and grass carp and evaluating the sensitization pattern in fish allergic subjects from two distinct populations in Asia. METHODS: One hundred and three fish allergic subjects were recruited from Hong Kong (67 subjects) and Japan (46 subjects). Western blot and mass spectrometry were used to identify allergens from salmon and grass carp. Fish allergens were purified and tested against 96 sera on ELISA to analyze patients' sensitization pattern. The protein profiles of salmon meat prepared under different cooking methods until core temperature reached 80 °C were evaluated by SDS-PAGE and mass spectrometry. RESULTS: Three common allergens between salmon and grass carp, namely enolase, glycerldehyde-3-phosphate dehydrogenase (GAPDH) and parvalbumin, and two salmon-specific allergens collagen and aldolase were identified. Parvalbumin was the major allergen for both fishes showing an overall sensitization rate of 74.7%, followed by collagen (38.9%), aldolase (38.5%) and enolase (17.8%). Japanese subjects showed more diverse allergen sensitization pattern and more frequent IgE-binding to heat-labile salmon allergens. Compared with steaming and boiling, cooking by baking and frying retained more fish proteins inclusive of heat-labile allergens. CONCLUSIONS: Fish allergic patients from different Asian populations show varying fish allergen sensitization profiles. The relevant extracts and components for diagnosis are population-dependent but parvalbumin and collagen are important biomarkers. Cooking methods modify allergen composition of salmon and appear to influence patients' allergic manifestations.


Assuntos
Hipersensibilidade Alimentar , Parvalbuminas , Animais , Imunoglobulina E , Peixes , Salmão , Colágeno , Hipersensibilidade Alimentar/diagnóstico , Hipersensibilidade Alimentar/epidemiologia , Alérgenos/química , Fosfopiruvato Hidratase , Aldeído Liases
5.
J Pediatr Nurs ; 59: 158-163, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33894543

RESUMO

BACKGROUND: Education is the most essential component for effective asthma control and is endorsed by guidelines worldwide. However, multiple caregivers are often jointly involved in child care, and educating them is often a challenging task. This study determines the effectiveness of a web-based asthma education program in enhancing knowledge, attitude and practice of caregivers and reducing unscheduled hospital visits of children for asthma. METHODS: A two-arm, randomized controlled trial was carried out between November 2018 and December 2019. Child-parent dyads were recruited when the children (4-11 years of age) were admitted due to asthma exacerbations. A nurse-led web-based home asthma education program was developed and implemented before discharge. Outcomes included parents' knowledge, attitude and practice regarding asthma and frequency of unscheduled visits and readmissions in children. RESULTS: 112 child-parent dyads were enrolled. The parents' knowledge, attitude and practice and the number of unscheduled visits of the children were found to be significantly different between two groups at different time points (Ps < 0.001) with a large effect size (Cohen's d > 0.8). CONCLUSION: This intervention was shown to be an effective strategy to educate caregivers who are jointly involved in their child's asthma control after discharge from hospital. TRIAL REGISTRATION: The Chinese Clinical Trial Registry, World Health Organization (ChiCTR1800019706).


Assuntos
Asma , Papel do Profissional de Enfermagem , Asma/prevenção & controle , Cuidadores , Humanos , Internet , Alta do Paciente
6.
Mult Scler ; 26(3): 294-303, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-30843756

RESUMO

BACKGROUND: Gray matter (GM) atrophy in brain is one of the best predictors of long-term disability in multiple sclerosis (MS), and recent findings have revealed that localized GM atrophy is associated with clinical disabilities. GM atrophy associated with each disability mapped to a distinct brain region, revealing a disability-specific atlas (DSA) of GM loss. OBJECTIVE: To uncover the mechanisms underlying the development of localized GM atrophy. METHODS: We used voxel-based morphometry (VBM) to evaluate localized GM atrophy and Clear Lipid-exchanged Acrylamide-hybridized Rigid Imaging-compatible Tissue-hYdrogel (CLARITY) to evaluate specific pathologies in mice with experimental autoimmune encephalomyelitis (EAE). RESULTS: We observed extensive GM atrophy throughout the cerebral cortex, with additional foci in the thalamus and caudoputamen, in mice with EAE compared to normal controls. Next, we generated pathology-specific atlases (PSAs), voxelwise mappings of the correlation between specific pathologies and localized GM atrophy. Interestingly, axonal damage (end-bulbs and ovoids) in the spinal cord strongly correlated with GM atrophy in the sensorimotor cortex of the brain. CONCLUSION: The combination of VBM with CLARITY in EAE can localize GM atrophy in brain that is associated with a specific pathology in spinal cord, revealing a PSA of GM loss.


Assuntos
Encefalomielite Autoimune Experimental/patologia , Substância Cinzenta/patologia , Esclerose Múltipla/patologia , Córtex Sensório-Motor/patologia , Medula Espinal/patologia , Animais , Atrofia/patologia , Encefalomielite Autoimune Experimental/diagnóstico por imagem , Feminino , Substância Cinzenta/diagnóstico por imagem , Hidrogéis , Imageamento por Ressonância Magnética , Camundongos , Camundongos Endogâmicos C57BL , Esclerose Múltipla/diagnóstico por imagem , Córtex Sensório-Motor/diagnóstico por imagem , Medula Espinal/diagnóstico por imagem
7.
Pediatr Res ; 88(5): 756-760, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32357362

RESUMO

BACKGROUND: To define the role of topical timolol maleate (TTM) in the treatment of infantile haemangiomata (IH). METHODS: In this single-centre randomised controlled trial, we included all <1-year-old infants within a 13-month period presenting with small (<2 cm) superficial IH located at high-risk areas (i.e. tip of ears, tip of nose, eyelids, acral areas, facial areas, scalp, neck, buttocks, perineum and axilla). Patients either received 12 months of 0.5% TTM solution (study group) or watchful waiting (control group). The primary outcome was IH with development of complications that required additional interventions. The secondary outcomes included side effects of TTM and change in IH size. RESULTS: Forty-two children were eligible to the study. Patients who received TTM were noted to have significantly fewer complications than the control group (4.2% versus 29%, odds ratio 9.58 [95% confidence interval: 1.01-91.62], p = 0.04). Mean IH volume percentage reduction was significantly more for the TTM group and no-TTM group at 3, 6 and 12 months. CONCLUSIONS: TTM is an effective and safe treatment option to reduce complications, IH volume and the need for further intervention for infants with small superficial IH located at high-risk areas. IMPACT: There is a lack of reliable signs to predict ulceration, disfigurement and other complications for high-risk IH. Treatment options range from watchful waiting to early systemic treatment, with TTM a novel and promising treatment. The exact role of TTM remains unanswered due to a lack of evidence-based research. TTM is effective and safe for infants with superficial IH of <2 cm in high-risk areas. Early TTM use on IH can reduce complications, IH volume and the need for further treatment.


Assuntos
Antagonistas Adrenérgicos beta/administração & dosagem , Antineoplásicos/administração & dosagem , Hemangioma/tratamento farmacológico , Timolol/administração & dosagem , Administração Cutânea , Antagonistas Adrenérgicos beta/efeitos adversos , Antineoplásicos/efeitos adversos , Feminino , Hemangioma/patologia , Hong Kong , Humanos , Lactente , Recém-Nascido , Masculino , Estudos Prospectivos , Fatores de Tempo , Timolol/efeitos adversos , Resultado do Tratamento , Carga Tumoral
9.
Opt Express ; 23(15): 19618-23, 2015 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-26367619

RESUMO

We report on a ceramic Yb:LuAG thin-disk laser in continuous wave operation. The Yb:LuAG ceramic was fabricated using solid-state reactive sintering method. In multi-mode operation in open-air, an output power of 1.74 kW with an optical-to-optical efficiency of 65.0% and slope efficiency of 71.2% was obtained. In near-fundamental mode operation we obtained an output power of 1.29 kW and an average beam quality factor of M2 = 1.44 with an optical-to-optical efficiency of 48.2%. The near-fundamental mode result was realized with a simple evacuated, stable resonator cavity with just the thin-disk gain medium and output coupler. To the best of the authors' knowledge, this is not only the first time more than 1 kW has been demonstrated from a ceramic Yb:LuAG medium, but this is also currently the brightest continuous wave Yb-doped ceramic laser.

10.
Tob Control ; 23 Suppl 2: ii4-10, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24732162

RESUMO

OBJECTIVE: To review the available evidence regarding electronic cigarette (e-cigarette) product characterisation and design features in order to understand their potential impact on individual users and on public health. METHODS: Systematic literature searches in 10 reference databases were conducted through October 2013. A total of 14 articles and documents and 16 patents were included in this analysis. RESULTS: Numerous disposable and reusable e-cigarette product options exist, representing wide variation in product configuration and component functionality. Common e-cigarette components include an aerosol generator, a flow sensor, a battery and a nicotine-containing solution storage area. e-cigarettes currently include many interchangeable parts, enabling users to modify the character of the delivered aerosol and, therefore, the product's 'effectiveness' as a nicotine delivery product. Materials in e-cigarettes may include metals, rubber and ceramics. Some materials may be aerosolised and have adverse health effects. Several studies have described significant performance variability across and within e-cigarette brands. Patent applications include novel product features designed to influence aerosol properties and e-cigarette efficiency at delivering nicotine. CONCLUSIONS: Although e-cigarettes share a basic design, engineering variations and user modifications result in differences in nicotine delivery and potential product risks. e-cigarette aerosols may include harmful and potentially harmful constituents. Battery explosions and the risks of exposure to the e-liquid (especially for children) are also concerns. Additional research will enhance the current understanding of basic e-cigarette design and operation, aerosol production and processing, and functionality. A standardised e-cigarette testing regime should be developed to allow product comparisons.


Assuntos
Sistemas Eletrônicos de Liberação de Nicotina , Aerossóis , Sistemas Eletrônicos de Liberação de Nicotina/efeitos adversos , Humanos
11.
Tob Control ; 23 Suppl 2: ii47-53, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24732164

RESUMO

OBJECTIVE: A systematic review was conducted to evaluate the impact of human factors (HF) on the risks associated with electronic cigarettes (e-cigarettes) and to identify research gaps. HF is the evaluation of human interactions with products and includes the analysis of user, environment and product complexity. Consideration of HF may mitigate known and potential hazards from the use and misuse of a consumer product, including e-cigarettes. METHODS: Five databases were searched through January 2014 and publications relevant to HF were incorporated. Voluntary adverse event (AE) reports submitted to the US Food and Drug Administration (FDA) and the package labelling of 12 e-cigarette products were analysed. RESULTS: No studies specifically addressing the impact of HF on e-cigarette use risks were identified. Most e-cigarette users are smokers, but data on the user population are inconsistent. No articles focused specifically on e-cigarette use environments, storage conditions, product operational requirements, product complexities, user errors or misuse. Twelve published studies analysed e-cigarette labelling and concluded that labelling was inadequate or misleading. FDA labelling analysis revealed similar concerns described in the literature. AE reports related to design concerns are increasing and fatalities related to accidental exposure and misuse have occurred; however, no publications evaluating the relationship between AEs and HF were identified. CONCLUSIONS: The HF impacting e-cigarette use and related hazards are inadequately characterised. Thorough analyses of user-product-environment interfaces, product complexities and AEs associated with typical and atypical use are needed to better incorporate HF engineering principles to inform and potentially reduce or mitigate the emerging hazards associated with e-cigarette products.


Assuntos
Sistemas Eletrônicos de Liberação de Nicotina/efeitos adversos , Medição de Risco , Humanos , Rotulagem de Produtos
12.
Int J Implant Dent ; 10(1): 35, 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38967690

RESUMO

Considering the biological activity of osteoblasts is crucial when devising new approaches to enhance the osseointegration of implant surfaces, as their behavior profoundly influences clinical outcomes. An established inverse correlation exists between osteoblast proliferation and their functional differentiation, which constrains the rapid generation of a significant amount of bone. Examining the surface morphology of implants reveals that roughened titanium surfaces facilitate rapid but thin bone formation, whereas smooth, machined surfaces promote greater volumes of bone formation albeit at a slower pace. Consequently, osteoblasts differentiate faster on roughened surfaces but at the expense of proliferation speed. Moreover, the attachment and initial spreading behavior of osteoblasts are notably compromised on microrough surfaces. This review delves into our current understanding and recent advances in nanonodular texturing, meso-scale texturing, and UV photofunctionalization as potential strategies to address the "biological dilemma" of osteoblast kinetics, aiming to improve the quality and quantity of osseointegration. We discuss how these topographical and physicochemical strategies effectively mitigate and even overcome the dichotomy of osteoblast behavior and the biological challenges posed by microrough surfaces. Indeed, surfaces modified with these strategies exhibit enhanced recruitment, attachment, spread, and proliferation of osteoblasts compared to smooth surfaces, while maintaining or amplifying the inherent advantage of cell differentiation. These technology platforms suggest promising avenues for the development of future implants.


Assuntos
Implantes Dentários , Osseointegração , Osteoblastos , Propriedades de Superfície , Osteoblastos/fisiologia , Osteoblastos/citologia , Humanos , Diferenciação Celular , Proliferação de Células , Titânio/química , Osteogênese/fisiologia
13.
Int J Implant Dent ; 10(1): 34, 2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38963524

RESUMO

Dental implant therapy, established as standard-of-care nearly three decades ago with the advent of microrough titanium surfaces, revolutionized clinical outcomes through enhanced osseointegration. However, despite this pivotal advancement, challenges persist, including prolonged healing times, restricted clinical indications, plateauing success rates, and a notable incidence of peri-implantitis. This review explores the biological merits and constraints of microrough surfaces and evaluates the current landscape of nanofeatured dental implant surfaces, aiming to illuminate strategies for addressing existing impediments in implant therapy. Currently available nanofeatured dental implants incorporated nano-structures onto their predecessor microrough surfaces. While nanofeature integration into microrough surfaces demonstrates potential for enhancing early-stage osseointegration, it falls short of surpassing its predecessors in terms of osseointegration capacity. This discrepancy may be attributed, in part, to the inherent "dichotomy kinetics" of osteoblasts, wherein increased surface roughness by nanofeatures enhances osteoblast differentiation but concomitantly impedes cell attachment and proliferation. We also showcase a controllable, hybrid micro-nano titanium model surface and contrast it with commercially-available nanofeatured surfaces. Unlike the commercial nanofeatured surfaces, the controllable micro-nano hybrid surface exhibits superior potential for enhancing both cell differentiation and proliferation. Hence, present nanofeatured dental implants represent an evolutionary step from conventional microrough implants, yet they presently lack transformative capacity to surmount existing limitations. Further research and development endeavors are imperative to devise optimized surfaces rooted in fundamental science, thereby propelling technological progress in the field.


Assuntos
Implantes Dentários , Osseointegração , Propriedades de Superfície , Titânio , Humanos , Titânio/química , Nanoestruturas/química , Osteoblastos , Planejamento de Prótese Dentária
14.
PLoS One ; 19(3): e0299295, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38452147

RESUMO

BACKGROUND: Accelerometers are widely adopted in research and consumer devices as a tool to measure physical activity. However, existing algorithms used to estimate activity intensity are wear-site-specific. Non-compliance to wear instructions may lead to misspecifications. In this study, we developed deep neural network models to classify device placement and activity intensity based on raw acceleration data. Performances of these models were evaluated by making comparisons to the ground truth and results derived from existing count-based algorithms. METHODS: 54 participants (26 adults 26.9±8.7 years; 28 children, 12.1±2.3 years) completed a series of activity tasks in a laboratory with accelerometers attached to each of their hip, wrist, and chest. Their metabolic rates at rest and during activity periods were measured using the portable COSMED K5; data were then converted to metabolic equivalents, and used as the ground truth for activity intensity. Deep neutral networks using the Long Short-Term Memory approach were trained and evaluated based on raw acceleration data collected from accelerometers. Models to classify wear-site and activity intensity, respectively, were evaluated. RESULTS: The trained models correctly classified wear-sites and activity intensities over 90% of the time, which outperformed count-based algorithms (wear-site correctly specified: 83% to 85%; wear-site misspecified: 64% to 75%). When additional parameters of age, height and weight of participants were specified, the accuracy of some prediction models surpassed 95%. CONCLUSIONS: Results of the study suggest that accelerometer placement could be determined prospectively, and non-wear-site-specific algorithms had satisfactory accuracies. The performances, in terms of intensity classification, of these models also exceeded typical count-based algorithms. Without being restricted to one specific wear-site, research protocols for accelerometers wear could allow more autonomy to participants, which may in turn improve their acceptance and compliance to wear protocols, and in turn more accurate results.


Assuntos
Aprendizado Profundo , Adulto , Criança , Humanos , Acelerometria , Exercício Físico , Algoritmos , Punho , Aceleração
15.
Neural Netw ; 176: 106328, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38688067

RESUMO

Given a graph G, the network collapse problem (NCP) selects a vertex subset S of minimum cardinality from G such that the difference in the values of a given measure function f(G)-f(G∖S) is greater than a predefined collapse threshold. Many graph analytic applications can be formulated as NCPs with different measure functions, which often pose a significant challenge due to their NP-hard nature. As a result, traditional greedy algorithms, which select the vertex with the highest reward at each step, may not effectively find the optimal solution. In addition, existing learning-based algorithms do not have the ability to model the sequence of actions taken during the decision-making process, making it difficult to capture the combinatorial effect of selected vertices on the final solution. This limits the performance of learning-based approaches in non-submodular NCPs. To address these limitations, we propose a unified framework called DT-NC, which adapts the Decision Transformer to the Network Collapse problems. DT-NC takes into account the historical actions taken during the decision-making process and effectively captures the combinatorial effect of selected vertices. The ability of DT-NC to model the dependency among selected vertices allows it to address the difficulties caused by the non-submodular property of measure functions in some NCPs effectively. Through extensive experiments on various NCPs and graphs of different sizes, we demonstrate that DT-NC outperforms the state-of-the-art methods and exhibits excellent transferability and generalizability.


Assuntos
Algoritmos , Redes Neurais de Computação , Tomada de Decisões/fisiologia , Humanos
16.
Artigo em Inglês | MEDLINE | ID: mdl-38358908

RESUMO

PURPOSE: Laser-created titanium surface topographies enhance soft tissue attachment and implant stability. However, knowledge about the underlying mechanisms governing the tissue-level reaction is lacking. The objective of this study was to examine the behavior and function of human gingival fibroblasts growing on healing abutments with or without laser-textured topography. MATERIALS AND METHODS: Human primary gingival connective tissue fibroblasts were cultured on healing abutments with machined or laser-textured (Laser-Lok, BioHorizons) surfaces. Cellular and molecular responses were evaluated by cell density assay (WST-1), fluorescence microscopy, qRT-PCR, and detachment test. RESULTS: The machined surface showed mono-directional traces and scratches from milling, whereas the laser-textured surface showed a distinct morphology consisting of mono-directional meso-scale channels (15 µm pitch) and woven, oblique micro-ridges formed within the channel. There were no differences in initial fibroblast attachment, subsequent fibroblast proliferation, nor collagen production between the machined and laser-textured surfaces. Fibroblasts growing on laser-textured surface spread mono-directionally along the meso-channels, while cells growing on machined surfaces spread randomly. Fibroblasts on laser-textured surfaces were 1.8-times more resistant to detachment than those on machined surfaces. An adhesive glycoprotein (fibronectin) and trans-membrane adhesion linker gene (integrin beta-1) were upregulated on laser-textured surfaces. CONCLUSIONS: The increased fibroblast retention, uniform growth, increased transcription of cell adhesion proteins compellingly explain the enhanced tissue-level response to laser-created, hybrid textured titanium surfaces. These results provide a cellular and molecular rationale for the tissue reaction to this unique surface and support its extended use from implant fixtures and healing abutments to diverse prosthetic components where enhanced soft tissue responses would be desirable.

17.
J Allergy Clin Immunol Pract ; 12(3): 633-642.e9, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37802255

RESUMO

BACKGROUND: Seafood is a common cause of food allergy and anaphylaxis, but there are limited published real-world data describing the clinical presentation of fish and shellfish allergies. OBJECTIVE: This study aimed to examine the clinical characteristics, immunological profile, and tolerance pattern to fish, crustaceans, and mollusks in fish-allergic individuals. METHODS: Patients presenting with IgE-mediated fish allergy between 2016 and 2021 were recruited. A comprehensive sensitization profile including specific IgE and skin prick test to various fish and shellfish species and a detailed clinical history including individuals' recent seafood consumption were evaluated. RESULTS: A total of 249 fish-allergic individuals (aged 4.2 ± 5.8 years) were recruited from 6 allergy clinics in Hong Kong, and they had experienced their fish-allergic reaction 2.2 ± 3.4 years before enrollment. Seventy-five subjects (30%) reacted to either grass carp, salmon, grouper, or cod in oral food challenges. We identified an IgE sensitization gradient that corresponded to the level of ß-parvalbumin in fish. In total, 40% of fish-allergic individuals reported tolerance to 1 or more types of fish, more commonly to fish with a lower ß-parvalbumin level such as tuna and salmon, compared with ß-parvalbumin-rich fish such as catfish and grass carp. Despite fish and shellfish cosensitization, 41% of individuals reported tolerance to crustaceans, mollusks, or both, whereas shellfish avoidance occurred in half of the fish-allergic individuals, of whom 33% lacked shellfish sensitization. CONCLUSIONS: Fish allergy commonly presents in early childhood. A considerable proportion of fish-allergic patients are selectively tolerant to certain fish, typically those with lower levels of ß-parvalbumin. There is an unmet need to promote precision medicine for seafood allergies.


Assuntos
Hipersensibilidade Alimentar , Parvalbuminas , Animais , Humanos , Pré-Escolar , Peixes , Alimentos Marinhos , Alérgenos , Imunoglobulina E
18.
Opt Lett ; 38(10): 1709-11, 2013 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-23938919

RESUMO

We report on a Yb:YAG thin-disk laser with 1.1 kW output power and beam quality factor M²<1.4 using a simple stable resonator comprising just a single cavity mirror and a single thin disk, without the use of any aspherical elements or any adaptive optics. An optical-to-optical efficiency of 40% was obtained. The cavity was designed to give good beam quality and low misalignment sensitivity to maintain stable and robust laser operation throughout the changes in the thin-disk curvature. To the best of the authors' knowledge, this is the first time an output power beyond 1 kW has been achieved from a single thin-disk laser in near fundamental mode operation (M²<1.4).

19.
Nano Lett ; 12(11): 5929-35, 2012 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-23098159

RESUMO

We experimentally demonstrate a vertically arrayed silicon nanowire-based device that exhibits voltage dependence of photoresponse to infrared sub-bandgap optical radiation. The device is fabricated using a proximity solid-state phosphorus diffusion method to convert the surface areas of highly boron-doped silicon nanowires into n-type, thus forming a radial core-shell p-n junction structure. Prominent photoresponse from such core-shell Si nanowires is observed under sub-bandgap illumination at 1310 nm. The strong bias dependence of the photoresponse and other device characteristics indicates that the sub-bandgap absorption is attributed to the intrinsic properties of core-shell Si nanowires rather than the surface states. The attractive characteristics are based on three physical mechanisms: the Franz-Keldysh effect, quasi-quantum confinement effect, and the impurity-state assisted photon absorption. The first two effects enhance carrier tunneling probability, rendering a stronger wave function overlap to facilitate sub-bandgap absorption. The last effect relaxes the k-selection rule by involving the localized impurity states, thus removing the limit imposed by the indirect bandgap nature of Si. The presented device uses single-crystal silicon and holds promise of fabricating nanophotonic systems in a fully complementary metal-oxide-semiconductor (CMOS) compatible process. The concept and approach can be applied to silicon and other materials to significantly extend the operable wavelength regime beyond the constraint of energy bandgap.

20.
J Prosthodont Res ; 67(2): 288-299, 2023 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-35858802

RESUMO

PURPOSE: A novel implant model consisting of meso-scale cactus-inspired spikes and nano-scale bone-inspired trabeculae was recently developed to optimize meso-scale roughness on zirconia. In this model, the meso-spike dimension had a significant impact on osteoblast function. To explore how different nano-textures impact this model, here we examined the effect of different nano-trabecula sizes on osteoblast function while maintaining the same meso-spike conformation. METHODS: Zirconia disks with meso-nano hybrid surfaces were created by laser etching. The meso-spikes were fixed to 40 µm high, whereas the nano-texture was etched as large and small trabeculae of average Feret diameter 237.0 and 134.1 nm, respectively. A polished surface was also prepared. Rat bone marrow-derived and human mesenchymal stromal cell-induced osteoblasts were cultured on these disks. RESULTS: Hybrid rough surfaces, regardless of nano-trabecula dimension, robustly promoted the osteoblastic differentiation of both rat and human osteoblasts compared to those on polished surfaces. Hybrid surfaces with small nano-trabeculae further enhanced osteoblastic differentiation compared with large nano-trabeculae. However, the difference in osteoblastic differentiation between small and large nano-trabeculae was much smaller than the difference between the polished and hybrid rough surfaces. The nano-trabecula size did not influence osteoblast attachment and proliferation, or protein adsorption. Both hybrid surfaces were hydro-repellent. The atomic percentage of surface carbon was lower on the hybrid surface with small nano-trabeculae. CONCLUSIONS: Small nano-trabeculae promoted osteoblastic differentiation more than large nano-trabeculae when combined with meso-scale spikes. However, the biological impact of different nano-trabeculae was relatively small compared with that of different dimensions of meso-spikes.


Assuntos
Biomimética , Osseointegração , Ratos , Humanos , Animais , Propriedades de Superfície , Zircônio , Diferenciação Celular , Titânio , Células Cultivadas
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa