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1.
Public Health ; 223: 217-222, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37677851

ABSTRACT

OBJECTIVES: We examined disparities in vaccine misinformation exposure and endorsement and the associations with vaccine hesitancy and vaccination uptake. STUDY DESIGN: Population-based survey. METHODS: A population-based survey was conducted on 5,002 Hong Kong adults oversampling low socio-economic status (SES, n = 2,200). Information on exposure (13 misinformation statements, total 0-13, median = 2), endorsement (13 statements, score 0-10, high scores indicate higher levels of endorsement, median = 5.75) of misinformation, vaccine hesitancy (14 items, score 1-5), and vaccination (two doses) were collected. Multivariable regression (adjusted ß [aß]) and Poisson regression (adjusted risk ratio [aRR]) adjusting for demographic characteristics were used to examine the associations of exposure to and endorsement of misinformation with vaccine hesitancy and vaccination. RESULTS: A total of 71.8% of respondents had at least exposure to one vaccine misinformation, and 35.7% had a high level of endorsement (median or above). Respondents with lower SES had a lower exposure (≤2 statements, 57.1% vs 50.1%, P < 0.001) but a higher level of endorsement (36.6% vs 34.9%, P = 0.01) of misinformation. Overall, 72.9% had been vaccinated for two or more doses, with a lower proportion in respondents with lower SES (83.6% vs 61.1%; P < 0.001). Compared with no exposure to misinformation, high levels of exposure and endorsement were associated with vaccine hesitancy (aß = 0.44, 95% confidence interval 0.40-0.48; aß = 0.50, 0.47-0.54, respectively) and lower vaccination rates (aRR = 0.98, 0.97-0.99; aRR = 0.92, 0.88-0.96, respectively). Vaccine hesitancy mediated the associations of exposure (fully, 100%) and endorsement (partially, 73%) with vaccination uptake. CONCLUSION: Endorsement of vaccine misinformation in respondents with lower SES was associated with low vaccination uptake.


Subject(s)
COVID-19 Vaccines , COVID-19 , Adult , Humans , Vaccination Hesitancy , Vaccination , Social Class , Communication
2.
Cardiovasc Intervent Radiol ; 42(3): 460-465, 2019 Mar.
Article in English | MEDLINE | ID: mdl-30603971

ABSTRACT

PURPOSE: To report technical success and clinical outcomes of transfemoral venous access for upper extremity dialysis interventions. MATERIALS AND METHODS: A total of 15 patients underwent a transfemoral venous approach for fistulography (n = 4; 27%) or thrombectomy (n = 11; 73%) over a 14-month period. Access characteristics, sheath size, thrombectomy method, angioplasty site, fluoroscopy time, radiation dose, technical and clinical success, complications, and post-intervention primary and secondary patency rates were recorded. RESULTS: Access type included arteriovenous fistulas (n = 10; 67%) and grafts (n = 5; 33%). The most common configuration was brachio-brachial (n = 6; 38%). Mean age of access was 37 months. Mean prior interventions were 4. Right CFV access was used in all patients using 6-8-French (most common: 7-French [n = 10; 67%]) sheaths. Most thrombectomies (n = 11; 73%) required both pharmacologic and mechanical maceration (n = 9; 82%). All accesses required angioplasty to treat underlying stenosis at the outflow vein (n = 12; 80%) or arteriovenous anastomosis (n = 9; 90%). Mean fluoroscopy time was 26.43 min. Air kerma and dose area product were 178.06 ± 225.77 mGy and 57,768.83 ± 87,553.29 µGym2, respectively. Procedural and clinical success rates were 93% and 80%, respectively. Technical failure was due to persistent stenosis in one patient. Clinical failure was due to unsuccessful dialysis immediately following intervention in three patients. Mean post-intervention primary patency and secondary patency durations were 2.8 and 4.8 months, respectively. Primary patency rates at 1 and 3 months were 50% and 35%, respectively. Secondary patency rates at 1 and 3 months were 58% and 30%, respectively. CONCLUSION: A transfemoral venous approach for intervention of upper extremity dialysis accesses may be a valuable adjunct to traditional approaches.


Subject(s)
Arteriovenous Shunt, Surgical/methods , Endovascular Procedures/methods , Femoral Vein , Renal Dialysis/methods , Upper Extremity/blood supply , Vascular Patency/physiology , Adult , Aged , Aged, 80 and over , Female , Fluoroscopy , Humans , Male , Middle Aged , Radiation Dosage , Retrospective Studies , Time Factors , Treatment Outcome
3.
Diagn Interv Imaging ; 98(10): 729-735, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28233711

ABSTRACT

PURPOSE: The purpose of this study was to characterize the hemodynamics of peripheral artery stent grafts to guide intelligent stent redesign. MATERIALS AND METHODS: Two surgically explanted porcine arteries were mounted in an ex vivo system with subsequent deployment of an Xpert self-expanding nitinol stent or Viabahn stent graft. The arteries were casted with radiopaque resin, and the cast then scanned using micro-computed tomography at 8µm isotropic voxel resolution. The arterial lumen was segmented and a computational mesh grid surface generated. Computational fluid dynamics (CFD) analysis was subsequently performed using COMSOL Multiphysics 5.1. RESULTS: CFD analysis demonstrated low endothelial shear stress (ESS) involving 9.4 and 63.6% surface area of the central stent graft and bare metal stent, respectively. Recirculation zones were identified adjacent to the bare metal stent struts, while none were identified in the central stent graft. However, the stent graft demonstrated malapposition of the proximal stent graft edge with low velocity flow between the PTFE lining and arterial wall, which was associated with longitudinally and radially oriented recirculation zones and low ESS. CONCLUSION: Computational hemodynamic analysis demonstrates that peripheral artery stent grafts have a superior central hemodynamic profile compared to bare metal stents. Stents grafts, however, suffer from malapposition at the proximal stent edge which is likely a major contributor to edge stenosis.


Subject(s)
Arterial Occlusive Diseases/diagnostic imaging , Self Expandable Metallic Stents , Stents , Alloys , Animals , Coated Materials, Biocompatible , Hemodynamics , Models, Animal , Polytetrafluoroethylene , Swine , X-Ray Microtomography
4.
Oncogene ; 36(4): 458-470, 2017 01 26.
Article in English | MEDLINE | ID: mdl-27321185

ABSTRACT

FLICE-like inhibitory protein (FLIP) is a critical regulator of death receptor-mediated apoptosis. Here, we found ubiquitin-specific peptidase 8 (USP8) to be a novel deubiquitylase of the long isoform of FLIP (FLIPL). USP8 directly deubiquitylates and stabilizes FLIPL, but not the short isoform. USP8 depletion induces FLIPL destabilization, promoting anti-Fas-, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)- and tumor necrosis factor alpha-induced extrinsic apoptosis by facilitating death-inducing signaling complex or TNFR1 complex II formation, which results in the activation of caspase-8 and caspase-3. USP8 mRNA levels are elevated in melanoma and cervical cancers, and the protein levels of USP8 and FLIPL are positively correlated in these cancer cell lines. Xenograft analyses using ME-180 cervical cancer cells showed that USP8 depletion attenuated tumor growth upon TRAIL injection. Taken together, our data indicate that USP8 functions as a novel deubiquitylase of FLIPL and inhibits extrinsic apoptosis by stabilizing FLIPL.


Subject(s)
CASP8 and FADD-Like Apoptosis Regulating Protein/genetics , CASP8 and FADD-Like Apoptosis Regulating Protein/metabolism , Endopeptidases/genetics , Endopeptidases/metabolism , Endosomal Sorting Complexes Required for Transport/genetics , Endosomal Sorting Complexes Required for Transport/metabolism , Ubiquitin Thiolesterase/genetics , Ubiquitin Thiolesterase/metabolism , Animals , Apoptosis/physiology , Cell Line, Tumor , Female , HEK293 Cells , HeLa Cells , Humans , Melanoma/genetics , Melanoma/metabolism , Melanoma/pathology , Mice , Mice, Inbred BALB C , Signal Transduction , Transfection , Uterine Cervical Neoplasms/genetics , Uterine Cervical Neoplasms/metabolism , Uterine Cervical Neoplasms/pathology
5.
Public Health ; 129(9): 1157-65, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26298590

ABSTRACT

OBJECTIVES: To analyse public attitudes towards access for non-citizens to publicly funded health care and to assess the factors that affect such attitudes. STUDY DESIGN: Cross-sectional study. METHODS: Data from 29 countries were used for a multilevel regression, and data from four countries (United States, Sweden, Philippines, and Korea) were used for a linear regression. The data were collected from the International Social Survey Program (ISSP), the World Bank, the Organization for Economic Cooperation and Development (OECD), and the United Nations. The dependent variable was considered to be agreement for non-citizen access to publicly funded health care. The independent variables included: the gross national income (GNI), the gross national income coefficient (GINI), sex, age, education, household income, employment, health insurance, self-related health status, chronic illness, percent having insurance, percent having public insurance, percent employed, percent migrants, percent of health expenditure of the total gross domestic product (GDP), and percent of social expenditure of the total GDP. Egalitarianism for education policy (EEP), egalitarianism for health policy (EHP), and willingness to contribute to an egalitarian health policy (WCHP) were also examined. RESULTS: In the countries surveyed, more than half of the citizens agreed that non-citizens should have access to publicly funded health care. Agreement with that statement had a negative trend with respect to the GNI. The percent having public insurance and WCHP had a significantly positive association with agreement while the percent of those with insurance had a negative relationship. In the USA, household income, EHP, and WCHP were positively associated with agreement, while females were inversely associated with agreement. In Sweden, having health insurance had an inverse association to agreement while females, postsecondary education, health insurance coverage, and WCHP were positively associated with agreement. In the Philippines, household income, EEP, and EHP had significant negative associations with agreement while WCHP had a positive relationship. In Korea, household income and self-rated health status were positively associated with agreement, while postsecondary education had a negative association. CONCLUSION: Public attitudes towards allowing non-citizens to have access to publicly funded health care present high levels of variation, even among developed countries or countries with similar GDPs. The specific socio-economic conditions within a country and an individual's own social, demographic, and economic background can have different effects on the individual's attitudes towards non-citizens. On a global level, coverage of public health insurance plays an important role for enhancing the public's positive attitudes towards non-citizens' access to publicly funded health care. On a national level, health care policies tailored toward non-citizens based on the specific situation of each country and region are necessary.


Subject(s)
Emigration and Immigration , Health Services Accessibility , National Health Programs , Public Opinion , Adult , Cross-Sectional Studies , Female , Health Policy , Humans , Male , Middle Aged , Multilevel Analysis , Philippines , Republic of Korea , Socioeconomic Factors , Sweden , United States
6.
Public Health ; 129(4): 385-95, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25724438

ABSTRACT

BACKGROUND: Today, non-communicable diseases, mainly cardiovascular diseases and diabetes, represent a leading threat to human health and development. This study observed mortality trends in all income group countries in relation to a wide variety of related factors like economical and environmental factors, health behaviour and health risk factors. STUDY DESIGN: Ecological study. METHOD: Data were analysed for 72 countries using the ecological study method. Data were collected from various sources including WHO, World Bank and previous studies. Cardiovascular disease and diabetes mortality rates for males and females were used as the dependent variables. GDP, GINI, literacy rate, urbanization, health expenditure, the number of physicians and the number of beds, BMI, western diet, blood glucose, blood pressure, serum cholesterol, physical inactivity, alcohol, and smoking were used as the independent variables initially. The final model was decided on the basis of availability of complete data and result of co-linearity test. Correlation test and linear regression were employed to identify the affecting factors for the dependent variables. RESULT: Analysis showed that cardiovascular disease and diabetes mortality was more concentrated in middle- and low-income countries and was negatively associated with GDP, GINI, and western diet. Countries with high average blood pressure had higher mortality rates showing a positive relationship. CONCLUSION: Non-communicable disease mortality rate is strongly associated with many economical, social, environmental, and behavioural factors. More comprehensive preventive and diagnostic strategies are needed to decrease mortality especially in low- and middle-income countries.


Subject(s)
Cardiovascular Diseases/mortality , Diabetes Mellitus/mortality , Global Health/statistics & numerical data , Environment , Female , Health Behavior , Humans , Male , Risk Factors , Socioeconomic Factors
7.
Cell Death Differ ; 22(9): 1463-76, 2015 Sep.
Article in English | MEDLINE | ID: mdl-25613375

ABSTRACT

Given their crucial role in apoptosis suppression, inhibitor of apoptosis proteins (IAPs) have recently become attractive targets for cancer therapy. Here, we report that cellular IAP2 (cIAP2) is specifically stabilized in several cancer cell lines, leading to resistance to Smac mimetics, such as BV6 and birinapant. In particular, our results showed that cIAP2 depletion, but not cIAP1 depletion, sensitized cancer cells to Smac mimetic-induced apoptosis. Ubiquitin-specific protease 11 (USP11) is a deubiquitylase that directly stabilizes cIAP2. USP11 overexpression is frequently found in colorectal cancer and melanoma and is correlated with poor survival. In our study, cancer cell lines expressing high levels of USP11 exhibited strong resistance to Smac mimetic-induced cIAP2 degradation. Furthermore, USP11 downregulation sensitized these cells to apoptosis induced by TRAIL and BV6 and suppressed tumor growth in a xenograft model. Finally, the TNFα/JNK pathway induced USP11 expression and maintained cIAP2 stability, suggesting an alternative TNFα-dependent cell survival pathway. Collectively, our data suggest that USP11-stabilized cIAP2 may serve as a barrier against IAP-targeted clinical approaches.


Subject(s)
Biomimetic Materials/pharmacology , Inhibitor of Apoptosis Proteins/metabolism , Neoplasms/drug therapy , Oligopeptides/pharmacology , Thiolester Hydrolases/metabolism , Ubiquitin-Protein Ligases/metabolism , Animals , Antineoplastic Combined Chemotherapy Protocols/pharmacology , Apoptosis/drug effects , Baculoviral IAP Repeat-Containing 3 Protein , Biomimetic Materials/chemistry , Cell Line, Tumor , Female , HCT116 Cells , HEK293 Cells , HT29 Cells , HeLa Cells , Humans , Mice , Mice, Inbred BALB C , Mice, Nude , Neoplasms/metabolism , Neoplasms/pathology , Oligopeptides/administration & dosage , Oligopeptides/chemistry , Signal Transduction , TNF-Related Apoptosis-Inducing Ligand/administration & dosage , TNF-Related Apoptosis-Inducing Ligand/pharmacology , Tumor Necrosis Factor-alpha/pharmacology , Xenograft Model Antitumor Assays
8.
Cell Death Differ ; 21(4): 594-603, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24336050

ABSTRACT

The central regulator of adipogenesis, PPARγ, is a nuclear receptor that is linked to obesity and metabolic diseases. Here we report that MKRN1 is an E3 ligase of PPARγ that induces its ubiquitination, followed by proteasome-dependent degradation. Furthermore, we identified two lysine sites at 184 and 185 that appear to be targeted for ubiquitination by MKRN1. Stable overexpression of MKRN1 reduced PPARγ protein levels and suppressed adipocyte differentiation in 3T3-L1 and C3H10T1/2 cells. In contrast, MKRN1 depletion stimulated adipocyte differentiation in these cells. Finally, MKRN1 knockout MEFs showed an increased capacity for adipocyte differentiation compared with wild-type MEFs, with a concomitant increase of PPARγ and adipogenic markers. Together, these data indicate that MKRN1 is an elusive PPARγ E3 ligase that targets PPARγ for proteasomal degradation by ubiquitin-dependent pathways, and further depict MKRN1 as a novel target for diseases involving PPARγ.


Subject(s)
Nerve Tissue Proteins/metabolism , PPAR gamma/metabolism , Ribonucleoproteins/metabolism , 3T3-L1 Cells , Adipocytes/cytology , Adipogenesis , Animals , Cell Differentiation , Cells, Cultured , HEK293 Cells , Humans , Lysine/metabolism , Mice , Mice, Inbred C57BL , Nerve Tissue Proteins/antagonists & inhibitors , Nerve Tissue Proteins/genetics , PPAR gamma/genetics , RNA Interference , RNA, Messenger/metabolism , RNA, Small Interfering/metabolism , Ribonucleoproteins/antagonists & inhibitors , Ribonucleoproteins/genetics , Ubiquitination
9.
Case Rep Radiol ; 2013: 607012, 2013.
Article in English | MEDLINE | ID: mdl-23401833

ABSTRACT

We present a rare case of continuous, extensive aortic dissection (AD) involving the bilateral common carotid arteries, the ascending, thoracic, and abdominal aorta, and bifurcation of the right common iliac artery. A 61-year-old man with history of chronic hypertension presented with a one-day history of chest pain, vertigo, left facial drooping, and left hemiparesis. Despite the presence of bilateral carotid bruits, doppler ultrasound of the neck was postponed, and the patient was treated with thrombolytic therapy for a presumed ischemic stroke. The patient's symptoms began to resolve within an hour of treatment, at which time treatment was withheld. Ultrasound performed the following day showed dissection of bilateral common carotid arteries, and CT angiography demonstrated extensive AD as described earlier. The patient subsequently underwent cardiovascular surgery and has been doing clinically well since then. AD has a myriad of manifestations depending on the involvement of aortic branches. Our paper illustrates the importance of having a high index of suspicion for AD when a patient presents with a picture of ischemic stroke, since overlapping signs and symptoms exist between AD and stroke. Differentiating between the two conditions is central to patient care as thrombolytic therapy can be helpful in stroke, but detrimental in AD.

10.
Cell Death Differ ; 20(4): 620-9, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23238566

ABSTRACT

The molecular mechanisms controlling post-translational modifications of p21 have been pursued assiduously in recent years. Here, utilizing mass-spectrometry analysis and site-specific acetyl-p21 antibody, two lysine residues of p21, located at amino-acid sites 161 and 163, were identified as Tip60-mediated acetylation targets for the first time. Detection of adriamycin-induced p21 acetylation, which disappeared after Tip60 depletion with concomitant destabilization of p21 and disruption of G1 arrest, suggested that Tip60-mediated p21 acetylation is necessary for DNA damage-induced cell-cycle regulation. The ability of 2KQ, a mimetic of acetylated p21, to induce cell-cycle arrest and senescence was significantly enhanced in p21 null MEFs compared with those of cells expressing wild-type p21. Together, these observations demonstrate that Tip60-mediated p21 acetylation is a novel and essential regulatory process required for p21-dependent DNA damage-induced cell-cycle arrest.


Subject(s)
Cyclin-Dependent Kinase Inhibitor p21/metabolism , DNA Damage , Histone Acetyltransferases/metabolism , Acetylation/drug effects , Amino Acid Motifs , Amino Acid Sequence , Animals , Cell Cycle Checkpoints , Cell Line , Cyclin-Dependent Kinase Inhibitor p21/genetics , DNA Repair , HCT116 Cells , Histone Acetyltransferases/antagonists & inhibitors , Histone Acetyltransferases/genetics , Histone Deacetylase Inhibitors/pharmacology , Histone Deacetylases/metabolism , Humans , Hydroxamic Acids/pharmacology , Lysine Acetyltransferase 5 , Mice , RNA Interference , RNA, Small Interfering/metabolism , Tumor Suppressor Protein p53/deficiency , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism , Ubiquitination
11.
Appl Ergon ; 44(3): 414-22, 2013 May.
Article in English | MEDLINE | ID: mdl-23153515

ABSTRACT

INTRODUCTION: Community nurses are exposed to high physical demands at work resulting in musculoskeletal disorders. The present study examined the short- and long-term benefits of a multifaceted intervention program designed especially for community nurses in Hong Kong. METHODS: Fifty community nurses working in 4 local hospitals participated in the study. All of them underwent an 8-week intervention program consisting of ergonomic training, daily exercise program, equipment modification, computer workstation assessment and typing training. RESULTS: All participants showed significant improvement in musculoskeletal symptoms and functional outcomes comparing pre- and post-intervention results. Significant reduction in symptom score was observed at 1-year follow-up compared to post-intervention. Symptomatic group (n=40) showed more significant changes overall compared to asymptomatic group (n=10). CONCLUSION: Results support the positive benefits, both short- and long-term, of the multifaceted ergonomic intervention programme for community nurses.


Subject(s)
Ergonomics/methods , Musculoskeletal Diseases/prevention & control , Nursing Staff, Hospital/education , Occupational Diseases/prevention & control , Adult , Computers/standards , Education, Nursing, Continuing/methods , Exercise , Female , Hong Kong , Humans , Male , Middle Aged , Nursing Staff, Hospital/statistics & numerical data , Occupational Health
12.
Prostate Cancer Prostatic Dis ; 14(3): 266-9, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21537347

ABSTRACT

The optimal management of men with very favorable clinicopathological factors who develop biochemical recurrence (BCR) after radical prostatectomy (RP) has not been previously reported. Both local and systemic recurrences are unlikely in this cohort. This study examines their management and outcomes. Between October 2000 to March 2010, 1627 men underwent open RP by a single surgeon. In all, 448 (27.5%) met the following criteria for extremely low risk disease: preoperative PSA level <10 ng ml(-1), clinical stage T1c/T2a, Gleason score 6, estimated cancer volume in the surgical specimen 5% and no evidence for positive surgical margin. Undetectable PSA was defined as 0.04 ng ml(-1). BCR was defined as PSA 0.2 ng ml(-1) or initiation of salvage radiation therapy (SRT) for progressively rising PSA. At 54 months mean follow-up (range 3-114 months), 9 (2%) of the 448 men developed BCR. Mean time to BCR was 63 months (range 12-93) and mean PSA doubling time was 15 months (range 6-27). Six underwent SRT, two elected surveillance and one was lost to follow-up. All men undergoing SRT exhibited more than 75% reduction in pre-SRT PSA, indicating the presence of local disease recurrence. All men undergoing SRT maintained PSA levels <0.1 at last follow-up. The BCR of 2% confirmed that we selected a cohort with extremely low risk for BCR after RP. We demonstrated that men fulfilling our criteria who develop BCR all harbor local disease based on favorable response to SRT. These men should be managed with SRT if recurrence is felt to be biologically significant.


Subject(s)
Neoplasm Recurrence, Local/prevention & control , Prostatic Neoplasms/prevention & control , Adult , Aged , Combined Modality Therapy , Follow-Up Studies , Humans , Male , Middle Aged , Neoplasm Recurrence, Local/blood , Neoplasm Recurrence, Local/radiotherapy , Prostate-Specific Antigen/blood , Prostatectomy , Prostatic Neoplasms/radiotherapy , Prostatic Neoplasms/surgery , Risk , Treatment Outcome
13.
Oncogene ; 29(28): 4101-12, 2010 Jul 15.
Article in English | MEDLINE | ID: mdl-20453884

ABSTRACT

In this study, we identified posttranslational regulation of human telomerase reverse-transcriptase (hTERT) by the E3 ligase Hdm2. The telomerase activity generated by exogenous hTERT in U2OS cells was reduced on adriamycin treatment. The overexpressed levels of hTERT were also decreased under the same conditions. These processes were reversed by treatment with a proteasome inhibitor or depletion of Hdm2. Furthermore, intrinsic telomerase activity was increased in HCT116 cells with ablation of Hdm2. Immunoprecipitation analyses showed that hTERT and Hdm2 bound to each other in multiple domains. Ubiquitination analyses showed that Hdm2 could polyubiquitinate hTERT principally at the N-terminus, which was further degraded in a proteasome-dependent manner. An hTERT mutant with all five lysine residues at the N-terminus of hTERT that mutated to arginine became resistant to Hdm2-mediated ubiquitination and degradation. In U2OS cells, depletion of Hdm2 or addition of the Hdm2-resistant hTERT mutant strengthened the cellular protective effects against apoptosis. Similar results were obtained with the Hdm2-stable H1299 cell line. These observations indicate that Hdm2 is an E3 ligase of hTERT.


Subject(s)
Proto-Oncogene Proteins c-mdm2/physiology , Telomerase/metabolism , Ubiquitin-Protein Ligases/metabolism , Cell Line, Tumor , Humans , Immunoprecipitation , Lysine/metabolism , Telomerase/chemistry , Ubiquitination
14.
J Nanosci Nanotechnol ; 9(10): 5745-51, 2009 Oct.
Article in English | MEDLINE | ID: mdl-19908447

ABSTRACT

Electrical properties of single ZnO nanobelt have been examined by fabricating single nanobelt based field effect transistors (FETs). The ZnO nanobelts were grown via non-catalytic simple thermal evaporation process by using metallic zinc powder in the presence of oxygen. The detailed structural and optical characterizations confirmed that the grown nanobelts are well-crystalline with the wurtzite hexagonal phase and exhibiting good optical properties. The passivation effect on the electrical characteristics of the as-grown nanobelts was also evaluated by passivating the fabricated FETs with polymethyl methacrylate (PMMA). The passivated single ZnO nanobelt based FETs exhibited higher electrical performance as compared to non-passivated FETs due to reduction in the physically absorbed chemisorbed species such as O-, O2-, O2, or OH- etc. The field effect mobility (micro(eff)) of the fabricated nanobelt based non-passivated and passivated FETs was estimated to be approximately 21.3 and 59 cm2/V x s, respectively. Moreover the carrier concentration and peak transconductance of the fabricated non-passivated and passivated FET were calculated to be approximately 8.73 x 10(17) and approximately 1.86 x 10(18) cm(-3) and approximately 0.76 and 1.4 microS, respectively. This work offers substantial opportunities for further practical electronics and photonics nanodevice applications of ZnO based nanostructures.

15.
Clin Radiol ; 64(5): 560-3, 2009 May.
Article in English | MEDLINE | ID: mdl-19348854

ABSTRACT

Toxoplasmosis can have catastrophic consequences in immunocompromised patients if left untreated. Accurate diagnosis is difficult, as there is substantial overlap between the imaging findings and presenting clinical syndromes of cerebral toxoplasmosis and primary central nervous system lymphoma. This paper reviews the previously described and fairly well-known post-contrast computed tomography (CT) and T1-weighted (W) magnetic resonance imaging (MRI) target signs seen in toxoplasmosis. In addition, it offers a new imaging sign, the T2W/FLAIR (fluid attenuated inversion recovery) target sign, which is often seen in clinical practice but not well-published, as an aid to the diagnosis of cerebral toxoplasmosis.


Subject(s)
Magnetic Resonance Imaging/methods , Toxoplasmosis, Cerebral/diagnosis , Central Nervous System Neoplasms/diagnosis , Diagnosis, Differential , Humans , Lymphoma/diagnosis , Retrospective Studies , Tomography, X-Ray Computed/methods
16.
J Nanosci Nanotechnol ; 8(11): 6010-6, 2008 Nov.
Article in English | MEDLINE | ID: mdl-19198339

ABSTRACT

Large-quality, well-crystallized growth of ZnO nanowires was done via non-catalytic thermal evaporation process on silicon substrate only by using metallic zinc powder and oxygen as source materials for zinc and oxygen, respectively. The electrical properties of the as-grown ZnO nanowires were examined by fabricating a single nanowire based FETs which were fabricated via two approaches, i.e., back- and top-gate approaches by using electron beam lithography (EBL) and photolithography processes. ZnO FETs electrical properties were characterized by I(DS)-V(DS) and I(DS)-V(GS) measurement. The fabricated single ZnO nanowire based FETs by back- and top-gate approaches exhibited field effect mobilities of approximately 4.25 and approximately 12.76 cm2/Vs, respectively. Moreover, the carrier concentrations for the fabricated back- and top-gate FETs were approximately 1.6 x 10(17) and approximately 1.37 x 10(18) cm(-3), respectively. From our studies it was observed that the fabricated top-gate FETs exhibited higher and good electrical properties as compared to ZnO nanowire FETs fabricated using back-gate approaches.


Subject(s)
Crystallization/methods , Microelectrodes , Nanotechnology/instrumentation , Nanotubes/chemistry , Transistors, Electronic , Zinc Oxide/chemistry , Electric Conductivity , Equipment Design , Equipment Failure Analysis , Macromolecular Substances/chemistry , Materials Testing , Molecular Conformation , Nanotechnology/methods , Nanotubes/ultrastructure , Particle Size , Surface Properties
17.
Water Sci Technol ; 51(6-7): 313-8, 2005.
Article in English | MEDLINE | ID: mdl-16003991

ABSTRACT

Secondary effluent reclamation and reuse has been considered as an alternative for agricultural irrigation water. Whilst all constituents in the reclaimed wastewater could affect plant growth and soil characteristics, the most important parameters for agricultural irrigation are salinity and SAR (Sodium Adsorption Ratio). Salinity affects the availability of crop water and sodium causes clay soils to disperse. Membrane technologies, especially NF (Nano-Filtration) and RO (Reverse Osmosis), have played in a key role reclaiming the secondary effluent. RO can remove monovalent and divalent cations simultaneously. However NF processes reject preferably divalent cations and most monovalent ions are allowed to pass through the NF membranes. This could make them have different SAR values for both NF and RO processes. Therefore the primary objective of this study is to examine if the SAR values of the reclaimed water could be changed while they undergo NF and RO processes. The measured SAR values of the secondary effluent, NF permeate, and RO permeate were 1.78, 4.67, and 0.72 respectively. The SAR value after NF (4.67) increased to more than twice that of the feed solution, whereas the SAR of the RO permeate decreased to 0.72. In general, the higher SAR the water has, the greater risk the soils have. Although the SAR value after NF was within the safe range, this increased SAR value will affect permeability of soil, thus limiting the reclaimed wastewater use for as agricultural irrigation water. Consequently, when the NF system is used for the reclamation of the secondary effluent, SAR has to be examined first because potentially it tends to increase the SAR value.


Subject(s)
Membranes, Artificial , Sodium/chemistry , Therapeutic Irrigation , Waste Disposal, Fluid/methods , Water Purification/methods , Adsorption , Agriculture , Osmosis , Salts/isolation & purification
18.
J Hand Surg Br ; 30(1): 29-34, 2005 Feb.
Article in English | MEDLINE | ID: mdl-15620488

ABSTRACT

The study evaluated the construct validity of the Chinese Hong Kong version of the disabilities of the arm, shoulder and hand questionnaire (DASH-HKPWH). Three hundred and thirty four patients with a broad range of upper extremity disorders were recruited into the study. Each completed DASH-HKPWH and SF-36 forms and their pain intensity (numeric pain rating scale) and grip strength were also measured. The mean DASH-HKPWH score was 40 (SD=20). Principal component factor analysis identified a single factor, which accounted for 47% of the total variance. Pearson correlation was applied to assess convergent and divergent validity of the DASH-HKPWH by comparison with the above-mentioned subjective and objective measurements. Our findings were comparable to the DASH of other languages.


Subject(s)
Disability Evaluation , Musculoskeletal Diseases/diagnosis , Musculoskeletal Diseases/rehabilitation , Surveys and Questionnaires , Adolescent , Adult , Aged , Arm , Asian People , Female , Hand , Humans , Language , Male , Middle Aged , Shoulder
19.
Surg Radiol Anat ; 26(6): 428-32, 2004 Dec.
Article in English | MEDLINE | ID: mdl-15290107

ABSTRACT

The patterns of the feeding vessels to each muscle determine the extent of their safe transposition and the muscle's value as a pedicled flap in reconstructive surgery. This study aimed to demonstrate the point of origin and the intra- and submuscular course of the pectoral branch of the thoracoacromial trunk (TAT) for pectoralis major (PM) flap surgery. Seventy sides of the PM were dissected based on a clinical reference line that has been used for several decades. The branching point of the TAT from the axillary artery was located lateral to the midclavicular line on the right-sided specimens (100%) and medial to the midclavicular line on the left sides (86%). The branching patterns of the pectoral branch to the PM muscle from the TAT were classified into three types. In type I the pectoral branches originated directly from the TAT (55 cases, 78.6%). In type II (11 cases, 15.7%) and type III (4 cases, 5.7%) the pectoral branch divided from the medial and lateral pedicle of the TAT, respectively. The course of the pectoral branch from the TAT in the PM was categorized into three patterns according to the degree of proximity to the midclavicular line. In 49 cases (70%), the pectoral branch in the PM ran within 1 cm of the midclavicular line. The other cases ran 2 cm (20 cases, 29%) and 3 cm (1 case, 1%) from the midclavicular line, respectively. These results provide topographic data of the pectoral branch based on anatomical landmarks, and will be useful in surgical planning as well as the procedure for PM flap surgery.


Subject(s)
Axillary Artery/anatomy & histology , Pectoralis Muscles/blood supply , Surgical Flaps/blood supply , Thoracic Arteries/anatomy & histology , Adult , Aged , Aged, 80 and over , Cadaver , Female , Humans , Male , Middle Aged , Pectoralis Muscles/anatomy & histology , Plastic Surgery Procedures/methods
20.
Brain Inj ; 18(6): 577-91, 2004 Jun.
Article in English | MEDLINE | ID: mdl-15204338

ABSTRACT

BACKGROUND AND PURPOSE: Quality of Life (QoL) studies have received a substantial amount of attention in medical and rehabilitative practices. However, there is still a paucity of studies in the area, especially on persons with brain injuries (BI). This pilot study, on the QoL of individuals with brain injuries in Hong Kong, attempts to fill this void. It is hoped that the finding of this study will guide the development of programmes and services to people with brain injuries. METHODS: Through the Self-help Group for People with Brain Damage in Hong Kong, 35 subjects (22 men and 13 women) were successfully recruited to participate in this study by convenience sampling. Demographic data were collected through face-to-face interviews guided by a questionnaire and QoL data were gathered using the Comprehensive Quality of Life Scale--Intellectual/Cognitive Disability--5th edition (ComQol-I5). The general emotional condition of the participants over the past 2 months was measured by a validated Chinese version of the Positive and Negative Affect Scale (PANAS). The participants' ratings on the importance of and their satisfaction with 20 health services areas were also collected. RESULTS: Preliminary results show that the overall mean quality of life score, as measured by ComQol-I5, was slightly less than two-thirds of the maximum score. Among the seven QoL domains, health and safety received some of the highest scores, while the lowest scores were obtained in the area of material well-being, place in community and productivity. People whose injuries had occurred relatively recently (less than 5 years ago) were found to have higher intimacy QoL scores than their counterparts injured more than 5 years ago. In the domain of safety, persons with a brain injury who were employed scored significantly higher than those who were not. Positive affect scores and the total affect of PANAS scores correlated significantly with the overall QoL scores. Moreover, persons with a brain injury usually felt satisfied with the services they valued as important. The top five most important services were medical services, occupational therapy, physiotherapy, vocational counselling and social work. DISCUSSION AND CONCLUSION: The QoL profile of people with brain injuries in Hong Kong was initially obtained and low scores in the ComQoL were identified in the domains of material well-being, community activities and responsibility and productivity. These might be the consequences of their physical and cognitive limitations due to brain injury. This implies that appropriate interventions to improve their daily life conditions and their social integration would be necessary to improve their QoL. On the other hand, the BI sample also rated relatively high scores in other ComQoL areas such as safety and health, reflecting a good living environment and probably good health care services. Those whose brain injuries had occurred less than 5 years ago tended to have a higher ComQoL intimacy score than those whose injuries occurred more than 5 years ago. In other words, their social relationships may deteriorate with the longer period post-injury so that this group may need more supportive services. In the safety domain, it was found that subjects who were employed after their brain injury scored significantly higher than those who were not, which matched studies about the significant contribution of work towards life satisfaction. The satisfaction of their needs in the services they received, which may affect their QoL, was also investigated. It is clear that they valued the medical and rehabilitation services they received and felt satisfied with them.


Subject(s)
Brain Injury, Chronic/rehabilitation , Health Services Needs and Demand , Quality of Life , Sickness Impact Profile , Adult , Aged , Brain Injury, Chronic/physiopathology , Brain Injury, Chronic/psychology , Employment , Epidemiologic Methods , Female , Hong Kong , Humans , Interpersonal Relations , Male , Middle Aged , Patient Satisfaction , Pilot Projects , Psychometrics
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