RESUMO
Novel processing phenomena coupled with various alloying materials used in metal additive manufacturing (AM) have opened opportunities for the development of previously unexplored micro-/nanostructures. A rationally devised structure nanofabrication strategy of AM surfaces that can tailor the interface morphology and chemistry has the potential for many applications. Here, through an understanding of grain formation mechanisms during AM, we develop a facile method for tuning micro-/nanostructures of one of the most used AM alloys and rationally optimize the morphology for applications requiring low surface adhesion. We demonstrate that optimized AM structures reduce the adhesion of impaling water droplets and significantly delay icing time. The structure can also be altered and optimized for antiflooding jumping-droplet condensation that exhibits significant enhancement in heat transfer performance in comparison to nanostructures formed on conventional Al alloys. In addition to demonstrating the potential of functionalized AM surfaces, this work also provides guidelines for surface-structuring optimization applicable to other AM metals.
Assuntos
Metais , Nanoestruturas , Ligas/química , Metais/químicaRESUMO
BACKGROUND: Since the beginning of the Syrian war in 2011, the world has faced the most severe refugee crisis in history and 5.6 million Syrians have sought asylum in neighbouring countries or in Europe. According to recent estimates, more than 650 000 Syrian refugees are displaced in Jordan. OBJECTIVES: This article aims to assess the demographic characteristics and skin disease profile of Syrian displaced people residing in Al Za'atari camp and in communities in Jordan. Furthermore, the authors discuss the barriers to healthcare provision experienced during field missions. METHODS: This is a retrospective analysis of medical records collected during three medical missions in Jordan by an international dermatological team. Data on patient age, gender, country of origin and skin disease diagnoses were recorded both in Al Za'atari camp and Jordanian towns near the Syrian border. RESULTS: A total of 1197 patients were assessed during the field missions, with 67.7% female and 37.1% under the age of 14 years. Dermatitis was the leading dermatological condition in both refugee camp and community healthcare clinics. Infectious diseases were the second most common; however, fungal presentations were more common in the community as opposed to viral in Al Za'atari. CONCLUSIONS: High dermatitis presentations were likely secondary to the environment, living conditions and lack of access to emollients. Infectious diseases were postulated secondary to poor hygiene and sharing of overcrowded spaces. Barriers to health care included limited pharmacological formulary, difficulty in continuity of care and case referrals due to lack of specialized services. Better access to health care, improvement of living conditions and hygiene, and increased availability of medications including emollients and sunscreens are all interventions that should be carried out to reduce skin disease burden. Our findings should further urge the international community to uphold their commitments and uptake engagement in improving health care for Syrian displaced people.
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Refugiados , Dermatopatias/epidemiologia , Feminino , Acessibilidade aos Serviços de Saúde , Humanos , Jordânia , Masculino , Aceitação pelo Paciente de Cuidados de Saúde , Estudos Retrospectivos , Dermatopatias/terapia , Síria/etnologiaRESUMO
The ability to learn that a stimulus no longer signals danger is known as extinction. A major characteristic of extinction is that it is context-dependent, which means that fear reduction only occurs in the same context as extinction training. In other contexts, there is re-emergence of fear, known as contextual renewal. The ability to properly extinguish fear memories and generalize safety associations to multiple contexts provides therapeutic potential, but little is known about the specific neural pathways that mediate fear renewal and extinction generalization. The ventral hippocampus (VH) is thought to provide a contextual gating mechanism that determines whether fear or safety is expressed in particular contexts through its projections to areas of the fear circuit, including the infralimbic (IL) and prelimbic (PL) cortices. Moreover, VH principal cells fire in large, overlapping regions of the environment, a characteristic that is ideal to support generalization; yet it is unclear how different projection cells mediate this process. Using a pathway-specific (intersectional) chemogenetic approach, we demonstrate that selective activation of VH cells projecting to PL attenuates fear renewal without affecting fear expression. These results have implications for anxiety disorders since they uncover a neural pathway associated with extinction generalization.
Assuntos
Extinção Psicológica/fisiologia , Medo/fisiologia , Giro do Cíngulo/fisiologia , Hipocampo/fisiologia , Rememoração Mental/fisiologia , Córtex Pré-Frontal/fisiologia , Animais , Comportamento Animal/fisiologia , Técnicas Genéticas , Masculino , Camundongos , Camundongos Endogâmicos C57BLRESUMO
Rubella is generally a mild and self-limited disease in children. During pregnancy, rubella can have potentially devastating effects on the developing fetus. Postnatal rubella is transmitted primarily by inhalation of virus-laden airborne droplets or direct contact with infected nasopharyngeal secretions. In susceptible pregnant women, the virus may cross the placenta and spread through the vascular system of the developing fetus. Postnatally acquired rubella typically begins with fever and lymphadenopathy, followed by an erythematous, maculopapular rash. The rash classically begins on the face, spreads cephalocaudally, becomes generalised within 24 hours, and disappears within 3 days. Maternal rubella, especially during early pregnancy, may lead to miscarriage, intrauterine fetal death, premature labour, intrauterine growth retardation, and congenital rubella syndrome. Cataracts, congenital heart defects, and sensorineural deafness are the classic triad of congenital rubella syndrome and they typically occur if the fetal infection occurs in the first 11 weeks of gestation. Laboratory confirmation of rubella virus infection can be based on a positive serological test for rubella-specific immunoglobulin M antibody; a four-fold or greater increase in rubella-specific immunoglobulin G titres between acute and convalescent sera; or detection of rubella virus RNA by reverse transcriptase-polymerase chain reaction. Treatment is mainly symptomatic. Universal childhood immunisation and vaccination of all susceptible patients with rubella vaccine to decrease circulation of the virus are cornerstones to prevention of rubella and, more importantly, congenital rubella syndrome.
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Síndrome da Rubéola Congênita/epidemiologia , Síndrome da Rubéola Congênita/prevenção & controle , Vacina contra Rubéola , Rubéola (Sarampo Alemão)/epidemiologia , Rubéola (Sarampo Alemão)/prevenção & controle , Criança , Pré-Escolar , Feminino , Humanos , Imunização , Lactente , Recém-Nascido , Masculino , Gravidez , Prognóstico , Vírus da RubéolaRESUMO
Systemic lupus erythematosus (SLE) is a chronic autoimmune disease which affects all aspects of quality of life (QoL) of the patients. Comprehensive patient assessment should include QoL measures in addition to the objective clinical measures of the disease. There is no specific Arabic instrument for assessment of QoL of SLE patients. The objective of this study was to translate and cross culturally adapt the SLEQOL questionnaire into Arabic and test its reliability and validity. The SLEQOL questionnaire was translated into Arabic based on the Guidelines for Translation and Cross-cultural Adaptation into other languages. Reliability was assessed by interviewing patients three times: two interviews on the same day by different interviewers and the third interview 14 days later by one of the first interviewers. Validity was assessed by correlating SLEQOL scores of 91 patients with 36-item Short Form Health Survey (SF-36) scores and clinical parameters of the patients. We found that the Arabic version of SLEQOL has a Cronbach's alpha of 0.936, interobserver and intraobserver correlation coefficients of 0.809 and 0.886 respectively. Strong correlations were also found between SLEQOL scores and SF-36 Physical and Mental Component summaries. In conclusion, the Arabic version of SLEQOL is a reliable and valid instrument for measuring QoL of Egyptian SLE patients.
Assuntos
Árabes/psicologia , Lúpus Eritematoso Sistêmico/diagnóstico , Qualidade de Vida , Inquéritos e Questionários , Tradução , Adolescente , Adulto , Características Culturais , Egito/epidemiologia , Feminino , Humanos , Entrevistas como Assunto , Lúpus Eritematoso Sistêmico/etnologia , Lúpus Eritematoso Sistêmico/psicologia , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Adulto JovemRESUMO
Measles (rubeola) is a highly contagious vaccine-preventable disease caused by the measles virus-a virus of the Paramyxoviridae family. The illness typically begins with fever, runny nose, cough, and pathognomonic enanthem (Koplik spots) followed by a characteristic erythematous, maculopapular rash. The rash classically begins on the face and becomes more confluent as it spreads cephalocaudally. Laboratory confirmation of measles virus infection can be based on a positive serological test for measles-specific immunoglobulin M antibody, a four-fold or greater increase in measles-specific immunoglobulin G between acute and convalescent sera, isolation of measles virus in culture, or detection of measles virus ribonucleic acid by reverse transcriptase-polymerase chain reaction. Complications occur in 10% to 40% of patients, and treatment is mainly symptomatic. Bacterial superinfections, if present, should be properly treated with antibiotics. To eradicate measles, universal childhood immunisation and vaccination of all susceptible individuals with measles vaccine would be ideal. In developed countries, routine immunisation with measles-containing vaccine is recommended, with the first and second doses at ages 12 to 15 months and 4 to 6 years, respectively. The World Health Organization recommends that the first and second doses of measles-containing vaccine be given at ages 9 months and 15 to 18 months, respectively, in countries with high rates of measles transmission.
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Vacina contra Sarampo-Caxumba-Rubéola/administração & dosagem , Sarampo/prevenção & controle , Vacinação , Serviços de Saúde da Criança , Humanos , LactenteRESUMO
UNLABELLED: Both men and women who sustain a fracture of the distal forearm run an increased risk of sustaining a subsequent hip fracture. Our study implies that these patients may not necessarily constitute a group in which osteoporosis screening is warranted. INTRODUCTION: People who sustain a distal radius fracture run an increased risk of sustaining a subsequent hip fracture. However, many institutions only screen for osteoporosis at the time of a hip fracture. We aimed to determine the true incidence of preceding distal radius fractures in an Asian population of patients with a hip fracture aged 60 years or older and whether screening for osteoporosis earlier would be beneficial. METHODS: We reviewed 22 parameters of 572 patients aged 60 years or older admitted after sustaining a hip fracture over a 3-year period. This included the occurrence or absence of a distal radius fracture in the 10 years preceding their hip fracture. RESULTS: Twenty-nine patients (5 %) had a fracture of the distal radius in the preceding decade. Univariate analyses suggested that hip fracture patients who had preceding distal radius fractures were older, female, have lower mean haemoglobin levels, and right-sided hip fractures. Of these factors, only age was found to have significant predictive value in a multivariate analysis. CONCLUSIONS: A number of institutions have started to screen for osteoporosis when a patient presents with a fracture of the distal radius because these patients may have an increased risk of a subsequent hip fracture. Our study implies that this may not be warranted. Implementing such a screening service from both cost and resource utilization point of view must be studied prospectively and in greater detail considering earlier screening may only be beneficial to a very small percentage of patients.
Assuntos
Fraturas do Quadril/etiologia , Osteoporose/diagnóstico , Fraturas por Osteoporose/diagnóstico , Fraturas do Rádio/etiologia , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Densidade Óssea/fisiologia , Feminino , Fraturas do Quadril/patologia , Fraturas do Quadril/fisiopatologia , Humanos , Masculino , Programas de Rastreamento/métodos , Pessoa de Meia-Idade , Osteoporose/complicações , Osteoporose/fisiopatologia , Fraturas por Osteoporose/patologia , Fraturas por Osteoporose/fisiopatologia , Fraturas do Rádio/fisiopatologia , Recidiva , Estudos Retrospectivos , Fatores de Risco , Fatores de TempoRESUMO
BACKGROUND: High-intensity resistance training (HIRT) programmes are increasingly popular amongst personal trainers and those attending gymnasiums. We report the experience of exertional rhabdomyolysis (ER) at two tertiary hospitals in Melbourne, Australia. AIMS: To compare the clinical outcomes of ER with other causes of rhabdomyolysis. METHODS: Retrospective cross-sectional study of patients presenting with a serum creatine kinase (CK) of greater than 25 000 units/L from 1 September 2013 to 31 August 2014 at two tertiary referral hospitals in Melbourne, Australia. Records were examined to identify care measures implemented during hospital stay, clinical outcomes during admission and on subsequent follow up. RESULTS: Thirty four cases of rhabdomyolysis with a CK of greater than 25 000 units/L (normal range: 20-180 units/L) were identified during the 12-month study period. Twelve of the 34 cases (35%) had ER with 10 of 12 related to HIRT. No acute kidney injury, intensive care admission or death were seen among those with ER. All cases were managed conservatively, with 11 admitted and 9 receiving intravenous fluids only. In contrast, patients with rhabdomyolysis from other causes experienced significantly higher rates of intensive care admission (64%, P = 0.0002), acute kidney injury (82%, P = 0.0001) and death (27%, P = 0.069). CONCLUSION: ER resulting from HIRT appears to have a benign course compared with rhabdomyolysis of other aetiologies in patients with a serum CK greater than 25 000 units/L. Conservative management of ER appears to be adequate, although this requires confirmation in future prospective studies.
Assuntos
Treinamento Resistido/efeitos adversos , Rabdomiólise/epidemiologia , Rabdomiólise/etiologia , Injúria Renal Aguda/epidemiologia , Adulto , Austrália , Creatina Quinase/sangue , Estudos Transversais , Feminino , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Centros de Atenção TerciáriaRESUMO
Evolution of dielectric function of Al-doped ZnO (AZO) thin films with annealing temperature is observed. It is shown that the evolution is due to the changes in both the band gap and the free-electron absorption as a result of the change of free-electron concentration of the AZO thin films. The change of the electron concentration could be attributed to the activation of Al dopant and the creation/annihilation of the donor-like defects like oxygen vacancy in the thin films caused by annealing.
Assuntos
Alumínio/análise , Membranas Artificiais , Tamanho da Partícula , Difração de Raios X/métodos , Óxido de Zinco/química , Cristalização , Elétrons , Teste de Materiais , Propriedades de Superfície , TemperaturaRESUMO
The contributions of localized surface plasmon resonance (LSPR) and Drude (free electrons) absorption to the complex dielectric function of ultrathin Au films were investigated with spectroscopic ellipsometry. When the Au film thickness is thinner than ~10 nm, Au nanoparticles (NPs) are formed as a result of the discontinuity in the films, leading to the emergence of LSPR of Au NPs; and the LSPR exhibits a splitting when the films thinner than ~8 nm, which could be attributed to the near-field coupling of the Au NPs and/or the inhomogeneous polarizations of the Au NPs. On the other hand, the delocalization of electrons in Au NPs due to the aggregation of Au NPs in a thicker film leads to an increase in the free-electron absorption and a suppression of the LSPR.
RESUMO
BACKGROUND: Total mesorectal excision (TME) remains commonplace for T1-2 rectal cancer owing to fear of undertreating a small proportion of patients with node-positive disease. Molecular stratification may predict cancer progression. It could be used to select patients for organ-preserving surgery if specific biomarkers were validated. METHODS: Gene methylation was quantified using bisulphite pyrosequencing in 133 unirradiated rectal cancer TME specimens. KRAS mutation and microsatellite instability status were also defined. Molecular parameters were correlated with histopathological indices of disease progression. Predictive models for nodal metastasis, lymphovascular invasion (LVI) and distant metastasis were constructed using a multilevel reverse logistic regression model. RESULTS: Methylation of the retinoic acid receptor ß gene, RARB, and that of the checkpoint with forkhead and ring finger gene, CHFR, was associated with tumour stage (RARB: 51·9 per cent for T1-2 versus 33·9 per cent for T3-4, P < 0·001; CHFR: 5·5 per cent for T1-2 versus 12·6 per cent for T3-4, P = 0·005). Gene methylation associated with nodal metastasis included RARB (47·1 per cent for N- versus 31·7 per cent for N+; P = 0·008), chemokine ligand 12, CXCL12 (12·3 per cent for N- versus 8·9 per cent for N+; P = 0·021), and death-associated protein kinase 1, DAPK1 (19·3 per cent for N- versus 12·3 per cent for N+; P = 0·022). RARB methylation was also associated with LVI (45·1 per cent for LVI- versus 31·7 per cent for LVI+; P = 0·038). Predictive models for nodal metastasis and LVI achieved sensitivities of 91·1 and 85·0 per cent, and specificities of 55·3 and 45·3 per cent, respectively. CONCLUSION: This methylation biomarker panel provides a step towards accurate discrimination of indolent and aggressive rectal cancer subtypes. This could offer an improvement over the current standard of care, whereby fit patients are offered radical surgery.
Assuntos
Biomarcadores Tumorais/genética , Tratamentos com Preservação do Órgão/métodos , Neoplasias Retais/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Caderinas/genética , Proteínas de Ciclo Celular/genética , Quimiocina CXCL12/genética , Metilação de DNA/genética , Proteínas Quinases Associadas com Morte Celular/genética , Feminino , Humanos , Metástase Linfática , Masculino , Instabilidade de Microssatélites , Pessoa de Meia-Idade , Mutação/genética , Metástase Neoplásica , Proteínas de Neoplasias/genética , Seleção de Pacientes , Proteínas de Ligação a Poli-ADP-Ribose , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas p21(ras) , Curva ROC , Receptores do Ácido Retinoico/genética , Neoplasias Retais/genética , Neoplasias Retais/patologia , Ubiquitina-Proteína Ligases , Proteínas ras/genéticaRESUMO
We present the results of a systematic study on the porosity of silica microparticles and nanowires prepared by glancing angle deposition-metal-assisted chemical etching (GLAD-MACE) and interference lithography-metal-assisted chemical etching (IL-MACE) techniques using the thermoporometry (TPM) method. Good agreement was obtained between our TPM results and published data provided by the suppliers of silica microparticles. TPM characterization of the GLAD-MACE and IL-MACE nanowires was carried out on the basis of parameters obtained from TPM experiments on microparticles. Our nanowires showed a similar trend but lower values of the pore volume and surface area than nanowires prepared by MACE with AgNO3 solution. We attribute the enhanced bioanalysis performance of the GLAD-MACE nanowires based devices to the increased pore volume and total surface area of the nanowires.
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Nanofios/química , Dióxido de Silício/química , Nitrato de Prata/química , Nanofios/ultraestrutura , Propriedades de SuperfícieRESUMO
Band gaps and exciton binding energies of undoped and Al-doped ZnO thin films were determined from optical absorption measurement based on the Elliott's exciton absorption theory. As compared to the undoped films, the doped films exhibit a band gap expansion and a reduction in the exciton binding energies due to the free electron screening effect, which suppresses the excitonic absorption and results in a blue shift of the absorption edge. The undoped and doped films show the same quantum size dependence, i.e. both the exciton binding energies and band gap energies increase with decreasing grain size of the oxides.
Assuntos
Alumínio/química , Membranas Artificiais , Nanopartículas Metálicas/química , Modelos Químicos , Óxido de Zinco/química , Simulação por Computador , Transporte de Elétrons , Elétrons , Teste de Materiais , Nanopartículas Metálicas/ultraestrutura , Teoria QuânticaRESUMO
Advanced scaffold fabrication techniques such as Rapid Prototyping (RP) are generally recognized to be advantageous over conventional fabrication methods in terms architectural control and reproducibility. Yet, most RP techniques tend to suffer from resolution limitations which result in scaffolds with uncontrollable, random-size pores and low porosity, albeit having interconnected channels which is characteristically present in most RP scaffolds. With the increasing number of studies demonstrating the profound influences of scaffold pore architecture on cell behavior and overall tissue growth, a scaffold fabrication method with sufficient architectural control becomes imperative. The present study demonstrates the use of RP fabrication techniques to create scaffolds having interconnected channels as well as controllable micro-size pores. Adopted from the concepts of porogen leaching and indirect RP techniques, the proposed fabrication method uses monodisperse microspheres to create an ordered, hexagonal closed packed (HCP) array of micro-pores that surrounds the existing channels of the RP scaffold. The pore structure of the scaffold is shaped using a single sacrificial construct which comprises the microspheres and a dissolvable RP mold that were sintered together. As such, the size of pores as well as the channel configuration of the scaffold can be tailored based on the design of the RP mold and the size of microspheres used. The fabrication method developed in this work can be a promising alternative way of preparing scaffolds with customized pore structures that may be required for specific studies concerning cell-scaffold interactions.
Assuntos
Análise em Microsséries/instrumentação , Microesferas , Engenharia Tecidual/instrumentação , Alicerces Teciduais/química , Animais , Desenho de Equipamento , Porosidade , Fatores de Tempo , Alicerces Teciduais/efeitos adversosRESUMO
OBJECTIVES: The English version of the Systemic Lupus Erythematosus Quality of Life Questionnaire (SLEQOL) is a validated disease-specific quality of life instrument. The aim of this study was to evaluate the psychometric properties of the Thai version of the SLEQOL (SLEQOL-TH). METHODS: Two independent translators translated the SLEQOL into Thai. The back translation of this version was performed by two other independent translators. The final version, SLEQOL-TH, was completed after resolving the discrepancies revealed by the back translation. One hundred and nine patients with SLE were enrolled to test the reliability, construct validity, floor and ceiling effects, and sensitivity to the changes of the SLEQOL-TH at six months. The differential item functioning (DIF) between the Thai and English versions was analyzed using the partial gamma. RESULTS: The internal consistency of the SLEQOL-TH was satisfactory with the overall Cronbach's alpha of 0.86. The test-retest reliability of the SLEQOL-TH was acceptable with the intra-class correlation coefficient of 0.86. Low correlations between the SLEQOL-TH and SLEDAI were observed. The total score of the SLEQOL-TH was moderately responsive to changes in quality of life, with a standardized response mean of 0.50. When comparing the SLEQOL-TH from Thai SLE patients with the original SLEQOL version obtained from Singapore SLE patients, 11 out of 40 items showed a moderate to large DIF. CONCLUSIONS: The SLEQOL-TH has acceptable psychometric properties and shows construct validity. In comparison with the English version of SLEQOL, there are some items that showed DIF. The applicability of the SLEQOL-TH in real-life clinical practice and clinical trials needs to be determined.
Assuntos
Lúpus Eritematoso Sistêmico , Qualidade de Vida , Adolescente , Adulto , Povo Asiático , Feminino , Humanos , Masculino , Psicometria , Reprodutibilidade dos Testes , Adulto JovemRESUMO
AIM: To identify and characterize novel bacteriocins from Weissella hellenica 4-7. METHODS AND RESULTS: Weissella hellenica 4-7, isolated from the traditional Taiwanese fermented food sian-sianzih (fermented clams), was previously found to produce a bacteriocin active against Listeria monocytogenes and some other Gram-positive bacteria. Bacteriocin activity decreased slightly after autoclaving (121°C for 15 min), but was inactivated by protease K and trypsin. Mass spectrometry analysis revealed the bacteriocin mass to be approximately 3205·6 Da. N-terminal amino acid sequencing yielded a partial sequence, NH2 -KGFLSWASKATSWLVGP, by Edman degradation. The obtained partial sequence showed high homology with leucocin B-TA33a; however, at least two different residues were observed. No identical peptide or protein was found, and this peptide was therefore considered to be a novel bacteriocin produced by W. hellenica 4-7 and termed weissellicin L. CONCLUSIONS: The findings obtained in the current study suggest a novel bacteriocin produced by W. hellenica 4-7. SIGNIFICANCE AND IMPACT OF THE STUDY: Bacteriocins from Weissella remain rare, and this study is the second report of a bacteriocin produced by W. hellenica.
Assuntos
Antibacterianos/química , Bacteriocinas/química , Weissella , Sequência de Aminoácidos , Animais , Antibacterianos/biossíntese , Antibacterianos/isolamento & purificação , Bacteriocinas/biossíntese , Bacteriocinas/isolamento & purificação , Bivalves/microbiologia , Dados de Sequência Molecular , Alimentos Marinhos/microbiologia , Weissella/isolamento & purificaçãoRESUMO
Treatment of esophageal cancer often requires surgical procedures that involve removal. The current approaches to restore esophageal continuity however, are known to have limitations which may not result in full functional recovery. In theory, using a tissue engineered esophagus developed from the patient's own cells to replace the removed esophageal segment can be the ideal method of reconstruction. One of the key elements involved in the tissue engineering process is the scaffold which acts as a template for organization of cells and tissue development. While a number of scaffolds range from traditional non-biodegradable tubing to bioactive decellularized matrix have been proposed to engineer the esophagus in the past decade, results are still not yet favorable with many challenges relating to tissue quality need to be met improvements. The success of new esophageal tissue formation will ultimately depend on the success of the scaffold being able to meet the essential requirements specific to the esophageal tissue. Here, the design of the scaffold and its fabrication approaches are reviewed. In this paper, we review the current state of development in bioengineering the esophagus with particular emphasis on scaffold design.
Assuntos
Esôfago/citologia , Engenharia Tecidual/métodos , Alicerces Teciduais/química , HumanosRESUMO
The capillary rise of liquid on a surface, or "wicking", has potential applications in biological and industrial processes such as drug delivery, oil recovery, and integrated circuit chip cooling. This paper presents a theoretical study on the dynamics of wicking on silicon nanopillars based on a balance between the driving capillary forces and viscous dissipation forces. Our model predicts that the invasion of the liquid front follows a diffusion process and strongly depends on the structural geometry. The model is validated against experimental observations of wicking in silicon nanopillars with different heights synthesized by interference lithography and metal-assisted chemical etching techniques. Excellent agreement between theoretical and experimental results, from both our samples and data published in the literature, was achieved.
Assuntos
Ouro/química , Nanoestruturas/química , Silício/química , Ação Capilar , Difusão , Cinética , Nanotecnologia , Tamanho da Partícula , Termodinâmica , MolhabilidadeAssuntos
Neoplasias Colorretais/cirurgia , Cuidados Pré-Operatórios/estatística & dados numéricos , Medicina Estatal , Tempo para o Tratamento/legislação & jurisprudência , Listas de Espera , Humanos , Avaliação de Resultados da Assistência ao Paciente , Cuidados Pré-Operatórios/legislação & jurisprudência , Reino UnidoRESUMO
A well-tested comprehensive Chinese positive youth development program (Project P.A.T.H.S.) developed in Hong Kong has been modified and adapted for use in Macau. This program aims to help adolescent school children develop positively and to be better prepared for their future. The present study investigated the effectiveness of the Tier 1 Program of "P.A.T.H.S." for Secondary 2 students of two pilot schools. Since there were "repeating" and "transferring" students joining the program, the effectiveness of the program on these particular groups of participants was also examined. The subjective outcome evaluations including participants' perceptions of the program, program instructors, benefits from the program, and overall satisfaction were positive. Although the longitudinal data from the objective outcome evaluation did not show any notable improvement, the overall effect of the program was found to be positive to the new comers in the junior secondary years. The existing evaluation findings suggest that the Secondary 2 program is especially effective to those newly joining the program. In view of the paucity of youth studies in Macau, the present study can contribute to evidence-based youth work and provide baseline data for the program to be evaluated in the Secondary 3 periods in the future.