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Background Widespread early use of biologic agents cannot be recommended for all Crohn’s disease patients, but for patient subgroups with a predicted disabling course such as perianal fistulas, the early introduction of a biologic agent can be considered. The aim of this study was to assess the outcome of the early use of infliximab after seton technique for patients with Crohn’s disease who initially presented with perianal fistulas Methods We retrospectively reviewed charts of patients with Crohn's disease who initially presented with perianal fistulas between January 2020 and December 2021. After confirm diagnosis of CD by endoscopic examination, all patients underwent both seton procedure and infliximab therapy by single colorectal surgeon. After third injection of infliximab, we removed silastic seton at once, or, in the case of active fistula, replaced it with nylon, and then removed it when the fistula was in remission. Outcomes included clinical remission based on physical examination with radiologic examination (including sonogram and MRI) and endoscopic findings up to last follow up. Results Overall, 31 patients were identified, [29 males (94%), mean age at diagnosis of Crohn’s disease 21.2 (9-32) years]. Half of patients (15/31) showed moderate to severe bowel severity at pre-treatment colonoscopy. Mean number of fistulas was 1.6 (1-4). The overall number of primarily placed setons was 70, of which 33 were inserted through the primary opening and the other 37 were placed between secondary openings. The mean interval between seton insertion and introduction of infliximab was 17.2 (7-30) days. The number of patients who changed silastic seton to nylon was 11. The mean follow-up was 24 months. In 27 patients, Setons were completely removed until last follow up. Interval between seton insertion and complete removal was 7 months ranged from 3 to 24 months. In colonoscopy performed 1 year after infliximab introduction, luminal Crohn's disease of most patients was in endoscopic remission (20/31) or improved (11/31) and there were no case of exacerbation. In 3 patients, because of local sepsis or pain after seton removal, seton procedure was performed again. 30 patients were in clinical remission and had no anal discomfort. Conclusion Early use (within 30 days) of infliximab after seton technique was very effective for patients with Crohn’s disease who initially presented with perianal fistulas. Seton removal should be started at least after remission induction. And replacing silastic seton with nylon was a simple and effective method.

In the past decades, water-related disasters had been accounted for about three-quarters of all-natural disasters worldwide. Asia is the most affected region with more than 45% of fatalities and more than 90% of the victims affected by aquatic disasters. Aquatic events progress differently and rapidly as compared to inland disasters. Thus, apart from additional equipments and trained aquatic rescuers, aquatic disaster operation requires specific strategies and tactics.This qualitative study was conducted using mixed methods involving the Delphi method and decision-conferencing approach. Two rounds of open-ended questionnaires were sent to subject matter experts from rescue agencies that involved in aquatic disaster rescue and management. Feedback from the panel was reviewed, the natural history of different aquatic disasters was appraised, and the decision-analysis model on the command, control and management of aquatic disaster was developed. The model was then reassessed through an iteration process at decision-conferencing among the expert panel until the final framework was accepted by all members of the panel.The fast progression of aquatic disasters with multiple hazards on the scene and unique technical challenges of the operation increase the risk of rescuers to become victims themselves. The developed conceptual framework, namely Aquatic Disaster Activation Plan and Tactic (ADAPT), was found able to guide rescuers in risk assessment, judgment, and response in aquatic disasters based on strategies and tactics for different phases along the natural history of aquatic disasters.With realistic scenario-based training and drills, ADAPT can be the blueprint in aquatic disaster management. It is designed to facilitate rescue agencies and organizations in preparing and executing the technical aquatic rescue operations safely, according to the resources available and the capability of the respective rescue organization.

Genetically determined leukoencephalopathies comprise a group of rare inherited white matter disorders. The majority are progressive diseases resulting in early death. We performed a cross-sectional pilot study including 55 parents from 36 families to assess the level of stress experienced by parents of patients with genetically determined leukoencephalopathies, aged 1 month to 12 years. Thirty-four mothers and 21 fathers completed the Parenting Stress Index–4th Edition. One demographic questionnaire was completed per family. Detailed clinical data was gathered on all patients. Statistical analysis was performed with total stress percentile score as the primary outcome. Mothers and fathers had significantly higher stress levels compared with the normative sample; 20% of parents had high levels of stress whereas 11% had clinically significant levels of stress. Mothers and fathers had comparable total stress percentile scores. We identified pediatric behavioral difficulties and gross motor function to be factors influencing stress in mothers. Our study is the first to examine parental stress in this population and highlights the need for parental support early in the disease course. In this pilot study, we demonstrated that using the Parenting Stress Index–4th Edition to assess stress levels in parents of patients with genetically determined leukoencephalopathies is feasible, leads to valuable and actionable results, and should be used in larger, prospective studies.

Chronic obstructive pulmonary disease (COPD) is a debilitating progressive lung disease characterised by irreversible airflow obstruction. In addition to an increase in morbidity and mortality, exacerbation also results in frequent hospital visits, which place a burden on healthcare systems. Non-invasive positive pressure ventilation (NPPV) with conventional inspiratory pressures is the standard ventilatory support for patients in exacerbation. At present, the use of higher inspiratory pressures through high intensity noninvasive positive pressure ventilation (Hi-NPPV) during an exacerbation remains unknown. We describe a novel application of Hi-NPPV in a patient with acute exacerbation who was refractory to conventional NPPV.

There were 290 multidrug-resistant (MDR)-TB cases diagnosed in Singapore from 2006 to 2018. Eighty-one percent were foreign-born. Spoligotyping and MIRU-VNTR methods identified 108 patients in 24 clusters. The Beijing spoligotype accounted for 22 clusters. Whole genome sequencing (WGS) analysis reduced the number of clustered patients and clusters to 43 and nine respectively. One MIRU cluster was redefined into three WGS clusters. All the clusters had foreign-born source cases. Forty percent of local-born, versus 9% of foreign-born, MDR-TB cases belonged to WGS clusters. WGS more accurately elucidated potential MDR-TB transmission which was overestimated by conventional genotyping methods in Singapore.

Hydroplaning is known as one of the factors which causes the highest rate of accident occurred on wet road condition. There are many factors that causes hydroplaning to occur on the tyre. The risk for hydroplaning occurs is related to one of these factors: tyre tread depth, tyre groove spacing, tyre groove width, surface depth water and pavement texture properties. All these have the factor for hydroplaning to occur on wet road condition. Tyre groove pattern has been commonly used in the industry to design daily used tyre for commercial passenger vehicle. It helps water escape through the groove tunnel during the drive. Hydroplaning speed can be increased through increasing the tyre groove depth. The aim of this study is to identify the groove pattern which has the highest risk of hydroplaning on wet road condition with three chosen tyre groove pattern. Rib pattern, lug pattern, block pattern have different characterize driving on road. From this study we can identify which is the best tyre groove pattern to reduce the risk of hydroplaning. Solidwork is used to visualize the 30 designs of the four tyre groove pattern. All of the tyre width are set to be at constant value with 185 mm. The 30 design can be analyzed and simulated through ANSYS software with the module Computational Fluid 0ynamic (CF0). CF0 allow us to simulate visualize the process of the tyre going through hydroplaning scenario stage by stage. The test environment for the simulation is set to be 500 x 500 x 5mm. The current finding shown that larger tyre groove width and depth and smaller tyre groove spacing experience higher hydroplaning speed. When the tyre contact point is at wet road surface, it will increase the rate of the water to escape though the channel. In conclusion, block groove tyre has is the best groove tyre to prevent the risk of hydroplaning.

BACKGROUND Tuberculosis (TB) drug-induced liver injury (TB-DILI) usually occurs within 8 weeks of anti-tuberculosis drug initiation. In Singapore, we suspected that the onset of TB drug-induced transaminitis may be confounded with hepatitis C virus (HCV) and hepatitis B (HBV) virus co-infection. OBJECTIVE To determine the impact of HCV/HBV co-infection on the course of treatment in patients with TB treatment interrupted due to transaminitis. DESIGN TB patients with treatment interruption during 2013-2014 were identified through the Singapore national TB registry. Case notes of those with transaminitis were perused. RESULTS Of 3860 TB patients notified, 140 had suspected TB-DILI. Of these, respectively 20/140 (14.3%) and 16/140 (11.4%) were HCV- or HBV-positive. The median time to treatment interruption/transaminitis was 5 weeks vs. 9.9 weeks and 9.6 weeks for transaminitis patients without chronic liver disease and with HCV/HBV co-infection (P < 0.01). Multivariate logistic regression analysis revealed that having HCV/HBV co-infection was associated with treatment interruption occurring beyond 8 weeks (adjusted OR [aOR] 4.06, 95%CI 1.28-12.85); HCV transaminitis patients were more likely to take 10 months to complete anti-tuberculosis treatment (aOR 5.11, 95%CI 1.21-21.67) than those without chronic liver disease. CONCLUSION TB treatment interruption due to transaminitis in HCV/HBV co-infected patients occurred later than in those without liver disease. Most had completed 2 months of pyrazinamide-containing intensive phase treatment before the onset of transaminitis.

Mutagenesis and selection of microalgae can be used for accelerated breeding of elite strains, providing a significant advantage over genetic engineering as prior biochemical and genetic information is not required. Ultraviolet (UV)-C-induced mutagenesis combined with fluorescence-activated cell sorting (FACS) and microtiter plate reader cell density screening was used to produce Tetraselmis suecica strains with increased lipid contents without compromising on cell growth. After five rounds of mutation-selection, two dosages of UV-C (50 and >98 % lethality) yielded two improved strains (M5 and M24) that produced significantly more neutral lipids (increases of 114 and 123 %, respectively). This study highlights that repeated UV-C mutagenesis and high-throughput selection for cell growth can be a viable combined approach to improve lipid productivity in microalgae. These maybe used as elite strains for future breeding programs and as potential feedstock for biodiesel production.

To map out key lipid-related pathways that lead to rapid triacylglyceride accumulation in oleaginous microalgae, RNA-Seq was performed with Tetraselmis sp. M8 at 24 h after exhaustion of exogenous nitrogen to reveal molecular changes during early stationary phase. Further gene expression profiling by quantitative real-time PCR at 16–72 h revealed a distinct shift in expression of the fatty acid/triacylglyceride biosynthesis and β-oxidation pathways, when cells transitioned from log-phase into early-stationary and stationary phase. Metabolic reconstruction modeling combined with real-time PCR and RNA-Seq gene expression data indicates that the increased lipid accumulation is a result of a decrease in lipid catabolism during the early-stationary phase combined with increased metabolic fluxes in lipid biosynthesis during the stationary phase. During these two stages, Tetraselmis shifts from reduced lipid consumption to active lipid production. This process appears to be independent from DGAT expression, a key gene for lipid accumulation in microalgae.

Systems analysis and design methods (SADMs), such as Jackson system development (JSD), have been proposed as a means of improving software quality. This is contrasted with the role of improving software usability proposed for human factors (HF). The paper argues the need for an explicit user interface specification stage in system development to ensure the usability of proposed systems. It is suggested that JSD supplemented by the specialist knowledge of HF can support such a specification stage. For HF and JSD to be successfully integrated, contributions from both need to be appropriately timed and structured. A model of the system development process that incorporates HF contributions is proposed. A means by which the HF contributions, in the form of a user interface specification, can be integrated with the JSD specification is developed and illustrated through examples.

SETTING: Singapore, which had a tuberculosis (TB) incidence rate of 41 per 100,000 resident population in 2011. OBJECTIVE: To report the outcomes of Singapore citizens and permanent residents treated for TB from 2002 to 2011. METHODS: A computerised treatment surveillance module (TSM) was launched in 2001 to track the progress and outcome of TB patients nationally. Physicians were required to submit an electronic or paper return for every patient at each clinic visit. Treatment adherence, drugs prescribed, treatment delivery mode and final outcome, specified as 'completed treatment', 'lost to follow-up', 'death', 'transferred out', 'permanent cessation of treatment' and 'still on treatment/no final outcome', were captured. Quarterly cohort outcomes at 12-15 months after starting treatment were combined to generate annual treatment outcomes. RESULTS: Treatment completion rates increased from 73.4% to 82.8%. The proportion of patients lost to follow-up decreased from 3.4% to 1.7%, while that of patients still on treatment or with no final outcome decreased from 10.5% to 4.4%. The death rate ranged between 10.2% and 11.7%; the majority were not attributed to TB. CONCLUSION: TB treatment completion among Singapore citizens and permanent residents has improved since 2002 as the likely result of the TSM and other initiatives introduced over the past decade.

SiGe for channel material has been explored as a major technology element after the introduction of FINFET into CMOS technology [1–4]. Research on long channel FETs and discrete short channel FETs demonstrated benefits in mobility [1–4] and reliability [2]. Given the disruption that SiGe FIN brings, every aspect associated with SiGe FIN needs to be carefully studied towards technology insertion. In this paper, we report the latest SiGe-based FINFET CMOS technology development. CMOS FINFETs with Si-FIN nFET and SiGe-FIN pFET is demonstrated as a viable technology solution for both server and mobile applications at 10nm node and beyond.

With increasing concerns about the world’s crude oil consumption, alternative fuels based on renewable resources attract more and more attention. Microalgae have been proposed to be one of the most sustainable feedstocks for the production of lipid-based biodiesel. Naturally occurring, high-lipid producing microalgae strains can be domesticated and further genetically improved in order to redirect metabolite fluxes towards increased lipid contents. This review summarizes the current knowledge about metabolic engineering of microalgae in order to increase the cellular lipid content, with an emphasis on triacylglycerols for the production of biofuels. Additionally, it outlines the contribution of systems biology and genome-scale metabolic pathway modeling, as well as their potential impact in the future.

Interest in a sustainable alternative to fossil fuels has recently intensified as the effects of rising oil costs and dangers of increasing CO2 levels are becoming more apparent. Microalgae-derived biodiesel provides a promising alternative, as theoretical calculations of areal microalgal oil production are at least 10 to 20-fold greater than any other biofuel crop. Importantly, microalgae cultivation can achieved without competing with precious arable land or rainforests and freshwater resources. At present, large-scale microalgal oil production is not economically viable, and many technical and biological barriers still need to be overcome in order to improve lipid productivity and reduce cost of production. The main objective of this thesis was to improve microalgal lipid productivity and gain a deeper understanding of the molecular mechanisms behind lipid biosynthesis. In the first part of the present work, numerous microalgal strains were collected from coastal water in South East Queensland, Australia. After isolation of pure strains, the fastest growing algae were compared to each other using a specially developed standardised lipid induction assay. This assay combined rapid exponential growth with a nutrient starvation phase to induce lipid biosynthesis, a survival mechanism of microalgae under adverse conditions. Based on their lipid productivity and fatty acid profile, several strains, including Nannochloropsis sp. BR2 and several Tetraselmis sp,, were identified as potential feedstock cultures for biodiesel production. As the identified cultures can be considered as undomesticated, one method of further increasing algal lipid productivity is via mutation and selection of high-lipid yielding algal strains. Instead of using a transgenic approach, this research used adaptive evolution methods, incorporating mutagenesis and high-throughput selection to select for high-lipid yielding algal strains. UV-C and different laser beams were used as mutagens, followed by a selection method encompassing flow cytometry and microplate readers to effectively select individual cells with high lipid contents, but also uncompromised growth. After several generations of mutation and selection, higher lipid accumulation potential was observed in several strains. This research also focused on understanding the underlying mechanisms of nitrogen- starved lipid induction in Tetraselmis sp. M8 through various growth phases.  Transcriptional profiling using RNA-Seq and quantitative real-time PCR analysis of this previously unsequenced genus, combined with physiological measurements after nutrient starvation, revealed that early lipid accumulation was predominately due to a reduced fatty acid degradation rate, while the rate of lipid biosynthesis remained unchanged. At 48 h onwards however, the expression of lipid biosynthesis genes was significantly upregulated, indicating lipid accumulation was now an effect of active triacylglyceride (TAG) synthesis. This first report on the molecular mechanisms of lipid accumulation in Tetraselmis sp. identified potential bottlenecks and target genes for metabolic engineering to maximise lipid accumulation in microalgae. Apart from strain improvement, culturing and lipid induction techniques offer further scope to optimise lipid productivity. Current efforts in the development of cost-effective harvesting and algal oil extraction procedures may further position microalgae as a significant feedstock for economical biodiesel production.

We review and extend data showing concerted evolution of parental 18-5.8-26S nuclear ribosomal DNA (18-26S rDNA) gene families in three natural Nicotiana allotetraploids (N. tabacum, N. rustica and N. arentsii, each 2n = 4x = 48) and one synthetic N. tabacum line (Th37, ♀ N. sylvestris (2n = 24) x ♂ N. tomentosiformis (2n = 24)). The origin of the gene families was analysed by sequence polymorphisms in the intergenic spacer (IGS) region and the number of chromosomal loci by fluorescence in situ hybridization (FISH). FISH revealed that the number and locations of 18-26S rDNA in the natural allopolyploids was the sum of those found in the diploid progenitors. However, the rDNA restriction patterns showed polymorphisms in the IGS that were not additive, suggesting that parental rDNA clusters were partially (N. tabacum, N rustica) or completely (N. arentsii) overwritten by hybrid-specific units. Thus the Nicotiana allotetraploids show evidence of concerted evolution, including both intralocus and interlocus gene conversion. A feral N. tabacum collected in Bolivia had a higher proportion of unconverted parental rDNA units than cultivated tobacco varieties, suggesting either that rDNA homogenization is accelerated by inbreeding or multiple origins of tobacco. There is no evidence for the elimination of N. sylvestris-derived rDNA units in the synthetic Th37 tobacco line as occurred in natural tobacco, although several novel rDNA unit variants were found in most but not all the hybrid plants. Factors that may control the occurrence and extent of rDNA homogenization are discussed for allopolyploids in Nicotiana and other taxa.

An ∼135-bp sequence called the A1/A2 repeat was isolated from the transcribed region of the 26-18S rDNA intergenic spacer (IGS) of Nicotiana tomentosiformis. Fluorescence in situ hybridization (FISH) and Southern blot analysis revealed its occurrence as an independent satellite (termed an A1/A2 satellite) outside of rDNA loci in species of Nicotiana section Tomentosae. The chromosomal location, patterns of genomic dispersion, and copy numbers of its tandemly arranged units varied between the species. In more distantly related Nicotiana species the A1/A2 repeats were found only at the nucleolar organizer regions (NOR). There was a trend toward the elimination of the A1/A2 satellite in N. tabacum (tobacco), an allotetraploid with parents closely related to the diploids N. sylvestris and N. tomentosiformis. This process may have already commenced in an S3 generation of synthetic tobacco. Cytosine residues in the IGS were significantly hypomethylated compared with the A1/A2 satellite. There was no clear separation between the IGS and satellite fractions in sequence analysis of individual clones and we found no evidence for CG suppression. Taken together the data indicate a dynamic nature of the A1/A2 repeats in Nicotiana genomes, with evidence for recurrent integration, copy number expansions, and contractions.

Cynipid gall formation is achieved by an insect-plant interaction whereby cynipid gallwasps redirect host-plant development to form novel structures to protect and nourish the developing larvae. Work was carried out to investigate the molecular mechanisms involved in this interaction, and extend the understanding of plant tissue development. Cytological changes of the inner-gall tissue throughout the development of several gall species was investigated and the developmental stages of gall formation defined, to reveal two different patterns of development followed by the galls tested. Fluorescent in situ hybridization demonstrated many of the inner-gall cells to be polytenized. Comparisons between inner-gall and non-gall tissue protein signatures by Schonrogge et al. (Plant, Cell and Environment 23, 215-222, 2000) have demonstrated the variation between gall and non-gall protein signatures, and identified a number of inner-gall proteins. Further analysis of one of these inner-gall proteins involved in lipid synthesis, putative biotin carboxyl carrier protein (BCCP), revealed differential expression throughout development, and showed this expression to be concentrated in the inner-gall tissue in all the gall species tested.

Different thicknesses of amorphous silicon carbide (a-SiC) and amorphous silicon nitride (a-SixNy) coatings were deposited on randomly aligned multiwall carbon nanotubes (MWNTs) by plasma enhanced chemical vapor deposition (PECVD). Their optical limiting properties were studied as a suspension in water. Optical limiting experiments show that they had slightly reduced optical limiting properties compared to pure MWNTs, the extent depending on the thickness and coating material. However, the linear transmission spectra of these coated MWNTs show a broader band transmission than pure MWNTs. This suggests that the coated MWNTs are more ideal as protective material for optical sensors as compared to pure MWNTs because they are effective over a wider optical transmission band.

O2+ ion beams are used to modify the surface of 50 nm thick Fe catalyst films deposited on Si(100) substrates to demonstrate selective area growth of aligned multiwall carbon nanotubes (MWNT). Aligned MWNTs were grown on the modified Fe/Si substrate using the hot filament plasma enhanced chemical vapor deposition (HF-PECVD) method. A higher growth rate and density of MWNTs was observed on the ion-modified areas, facilitating selective area growth of aligned MWNTs at temperatures as low as 560 °C. Deposition of graphitic sheets at the initial growth process on the unmodified areas inhibits the deposition of MWNTs.

Tip characteristics play an important role in the resolution and sensitivity of scanning probe microscopy. Extensive efforts have been devoted to tip fabrication. Most of the research is focused on scanning tunneling microscopy applications, which require sharp and short tips. Long tips that can be bent into cantilevered tips have great potential in atomic force microscopy/apertureless near-field scanning optical microscopy applications. However, the fabrication of such tips has been rarely reported. The present work is carried out with the aim of optimizing the conditions suitable for fabricating long and sharp tungsten tips. Besides topography, optical, and spectroscopic information, electrical and magnetic measurements can also be carried out with such tips obtained with the recipe reported in this article. The long tips also make it possible to measure deep grooves/trenches.

With the depletion of global fish stocks, caused by high demand and effective fishing techniques, alternative sources for long chain omega-3 fatty acids are required for human nutrition and aquaculture feeds. Recent research has focused on land-based cultivation of microalgae, the primary producers of omega-3 fatty acids in the marine food web. The effect of salinity on fatty acids and related gene expression was studied in the model marine microalga, Tetraselmis sp. M8. Correlations were found for specific fatty acid biosynthesis and gene expression according to salinity and the growth phase. Low salinity was found to increase the conversion of C18:4 stearidonic acid (SDA) to C20:4 eicosatetraenoic acid (ETA), correlating with increased transcript abundance of the Δ-6-elongase-encoding gene in salinities of 5 and 10 ppt compared to higher salinity levels. The expression of the gene encoding β-ketoacyl-coenzyme was also found to increase at lower salinities during the nutrient deprivation phase (Day 4), but decreased with further nutrient stress. Nutrient deprivation also triggered fatty acids synthesis at all salinities, and C20:5 eicosapentaenoic acid (EPA) increased relative to total fatty acids, with nutrient starvation achieving a maximum of 7% EPA at Day 6 at a salinity of 40 ppt.

Cell suspension-derived protoplasts of two cultivated Rubus species, Rubus idaeus-raspberry (subgenus Idaeobatus 2n=2x=14) and R. fruticosus-blackberry (a complex species aggregate within the subgenus Eubatus, 2n=4x=28) were fused using different polyethylene glycol (PEG) fusion treatments. Duration of PEG treatment and choice of culture media influenced the rate of cell divisions and plating efficiency. Colony formation was initiated on solid media for the production of several callus lines. Cytological analyses were performed on selected callus lines with hexaploid chromosome number. Two hexaploid fusion callus lines, selected for their homogeneity in growth and ploidy level, were examined by molecular cytogenetic techniques of fluorescent in situ hybridisation (FISH) and genomic in situ hybridisation (GISH). GISH revealed the presence of the heterokaryon within the fusion callus lines. FISH probed with ribosomal DNA (rDNA) showed variable numbers and sizes of loci. Aberrant distribution and co...

Evaluation of: Huerlimann R, de Nys R, Heimann K. Growth, lipid content, productivity, and fatty acid composition of tropical microalgae for scale-up production. Biotechnol. Bioeng. 107(2), 245–257...

The National Tuberculosis Programme in Singapore where, among resident cases, higher tuberculosis (TB) rates have been reported in ethnic Malays.To describe the socio-demographic and clinical characteristics of resident TB cases by ethnicity, and to assess whether Malays differ from other groups in terms of the above parameters.Cross-sectional review of records from the tuberculosis registry's electronic database.Among 15 622 resident cases notified, 72.2% were Chinese, 18.7% Malay, 5.8% Indian and 2.9% were from other minorities. Compared to other ethnicities, Malays were more likely to be incarcerated at the time of notification (odds ratio [OR] 3.70, 95%CI 3.03-4.52) and clustered at the same residential address (OR 1.65, 95%CI 1.44-1.89), but were less likely to be aged ≥65 years (OR 0.61, 95%CI 0.54-0.70) or to reside in high-cost housing (OR 0.11, 95%CI 0.07-0.17). In terms of disease characteristics, more Malays had diabetes mellitus (OR 1.54, 1.37-1.73), a highly-positive acid-fast bacilli smear (OR 1.64, 95%CI 1.47-1.83) and cavitary disease on chest X-ray (OR 1.41, 95%CI 1.28-1.55).Compared to other ethnicities, reported TB cases among Malays were more severe and were likely to be more infectious. Increased vigilance in case management and contact investigations, as well as an improvement in the socio-economic conditions of this community, are required to reduce TB rates in this ethnic group.Programme National de la Tuberculose à Singapour, où parmi les cas chez les résidents, des taux plus élevés de tuberculose (TB) ont été signalés chez les sujets d’ethnie malaise.Décrire les caractéristiques socio-démographiques et cliniques des cas de TB chez les résidents en fonction de leur ethnie et évaluer dans quelle mesure les Malais diffèrent des autres groupes en ce qui concerne ces paramètres.Révision transversale des dossiers de la base de données électroniques du registre de la tuberculose.Parmi 15 622 cas déclarés chez les résidents, 72,2% étaient Chinois, 18,7% Malais, 5,8% Indiens et 2,9% originaires d’autres minorités. Par comparaison avec les autres ethnies, les Malais sont plus susceptibles d’être emprisonnés au moment de la déclaration (OR 3,70 ; IC95% 3,03–4,52) et de se retrouver en grappes à la même adresse de résidence (OR 1,65 ; IC95% 1,44–1,89), mais sont moins susceptibles d’avoir un âge ≥65 ans (OR 0,61 ; IC95% 0,54–0,70) et de résider dans des habitats à coût élevé (OR 0,11 ; IC95% 0,07–0,17). En termes de caractéristiques de la maladie, chez les Malais le diabète sucré est plus fréquent (OR 1,54 ; IC95% 1,47–1,73), les frottis à la recherche de bacilles acido-résistants sont plus fortement positifs et une excavation est plus fréquente au cliché thoracique (OR 1,41 ; IC95% 1,28–1,55).Par comparaison avec ceux d’autres ethnies, les cas de TB signalés chez les Malais sont plus graves et plus susceptibles d’être contagieux. Si l’on veut réduire les taux de TB dans cette ethnie, il faut veiller à une vigilance accrue dans la prise en charge des cas et dans les investigations des contacts ainsi qu’à une amélioration des conditions socio-économiques de cette collectivité.El Programa Nacional contra la Tuberculosis en Singapur, donde las tasas más altas de tuberculosis (TB) en los residentes se notifican en la población de etnia malaya.Describir las características sociodemográficas y clínicas de los casos de TB en residentes en función de la etnia de los pacientes y evaluar si los malayos se diferencian de otros grupos con respecto a estos criterios.Se llevó a cabo un estudio transversal con examen de las historias clínicas a partir de la base de datos electrónica del registro de TB.De los 15 622 casos residentes notificados, el 72,2% correspondió a chinos, el 18,7% a malayos, el 5,8% a indios y el 2,9% a pacientes pertenecientes a otras minorías. En comparación con otras etnias, fue más frecuente que los malayos estuviesen reclusos en el momento de la notificación (OR 3,70; IC95% 3,03–4,52) y que se encontrasen agrupados en una misma dirección domiciliaria (OR 1,65; IC95% 1,44–1,89); fue menos frecuente que tuviesen ≥65 años de edad (OR 0,61; IC95% 0,54–0,70) y que habitasen en viviendas de alto costo (OR 0,11; IC95% 0,07–0,17). Con respecto a las características de la enfermedad, más malayos tenían un diagnóstico de diabetes (OR 1,54; IC95% 1,37–1,73), obtuvieron una baciloscopia positiva de alto grado (OR 1,64; IC95% 1,47–1,83) y presentaron imágenes de cavernas en la radiografía de tórax (OR 1,41; IC95% 1,28–1,55).En comparación con otras etnias, los casos de TB notificados en la población malaya fueron más graves y con mayor frecuencia eran contagiosos. Sería oportuno prestar mayor atención al manejo de los casos y a la investigación de los contactos en esta comunidad, a fin de disminuir las tasas de TB en las personas de etnia malaya.

Photoluminescence properties of undoped wurtzite GaN epilayers grown on sapphire substrates with different buffer layer treatment conditions in metalorganic chemical vapor deposition (MOCVD) growth have been studied as a function of temperature. At low temperatures, very well resolved spectral features associated with the GaN band structure were observed. From the photoluminescence (PL) data for free excitons, an accurate value of the A exciton binding energy was found. The localization energies of the excitons bound to neutral acceptor are found to agree with Haynes’ rule with the proportionality factor close to 0.1. The longitudinal optical (LO) phonon assisted photoluminescence associated with both the bound and free excitons has been observed. The characteristics of free excitons and their LO phonon replica have been studied in detail with the temperature variation and related to the point defects. The behavior of the peak energy and the full width at half maximum of the exciton band as a function of ...

We investigated the effects of grain boundary diffusion (GBD) at elevated temperatures on Auger electron spectroscopy sputter depth profiles of Co-Ag bilayers by using the modified surface accumulation method which is proposed for the first time to our knowledge. The results agree well with our previous ones done by the surface accumulation method. The GBD parameters for Ag in Co along the grain boundaries were found to be as follows: the activation energy and pre-exponential factor for GBD are 0.425±0.025 eV and ∼1×10−7cm2, respectively. These indicate that the modified method is an effective alternative in studying the effects of GBD, and may be applied to complicated systems for which the previous method does not hold.

Detection of electrical leakage in semiconductor devices indicates presence of electrical paths between junctions of p-doped and n-doped silicon, if no other physical abnormality is observed. This paper describes the use of advanced failure analysis tools to precisely locate and visualize crystalline defects in silicon that have caused electrical failure.

We investigated the effects of surface roughness and grain boundary diffusion (GBD) at elevated temperatures on the Auger‐electron‐spectroscopy sputter depth profiles of Co–Ag bilayers and the GBD process of Ag atoms in Co. The Ag layer in the Ag/Co bilayer is transformed from a uniform layer to discrete islands by heat treatment. Enhanced mobility during sputtering at elevated temperatures makes Ag atoms migrate continually from islands to cover neighboring exposed Co, which reduces the size of Ag islands. On the other hand, the surface morphological modification of Co/Ag bilayer does not occur by heat treatment, and the depth profile at 340 °C resembles that from a uniformly intermixed film, which shows a drastic difference from that of Ag/Co. This is explained with a very thin and stable accumulation of Ag on the Co layer by GBD. A model of structural changes in Co/Ag subjected to ion sputtering at elevated temperatures is proposed on the basis of the results. The activation energy and pre‐exponential ...

We fabricated the AlGaN∕GaN metal-oxide-semiconductor heterostructure field-effect transistor (MOSHFET) using the oxidized Ni(NiO) as a gate oxide and compared electrical properties of this device with those of a conventional AlGaN∕GaN heterostructure field-effect transistor (HFET). NiO was prepared by oxidation of Ni metal of 100A at 600°C for 5min in air ambient. For HFET and MOSHFET with a gate length of 1.2μm, the maximum drain currents were about 800mA∕mm and the maximum transconductances were 136 and 105mS∕mm, respectively. As the oxidation temperature of Ni increased from 300 to 600°C the gate leakage current decreased dramatically due to the formation of insulating NiO. The gate leakage current for the MOSHFET with the oxidized NiO at 600°C was about four orders of magnitude smaller than that of the HFET. Based on the dc characteristics, NiO as a gate oxide is comparable with other gate oxides.

Photoluminescence of AlxGa1−xAs/AlyGa1−yAs heterostructures has been performed in presence of high magnetic fields. Under the magnetic field the broad carbon related peak becomes resolved into several narrow peaks. Experimental results and a theoretical analysis based on the single band model suggest that these peaks are due to the recombination of free electrons with holes bound to neutral carbon atoms distributed in the several atomic layers in the well side of the interfaces of the heterostructures. Magnetic fields reduce the effects of interfacial roughness and make it possible to resolve the carbon related peak into several peaks.

We have studied the influence of electric fields on the Mg-doped p-GaN by using Raman scattering and photocurrent (PC) measurement. It has been observed that the E2 (LO) mode was quenched upon increasing the electric field. To explain this effect, the combined results obtained from the electric-field-induced Raman scattering and the PC measurement were analyzed. As a result, we have found that the damping of E2 (LO) mode is caused to the phonon–hole scattering due to a strong interaction between the phonons and the photogenerated hole carriers with increasing the applied electric field.

The Al2O3 powder was embedded in indium tin oxide (ITO) using natural lithography for high efficiency GaN‐based light‐emitting diodes (LEDs). The 300‐nm‐size Al2O3 powder is coated on the first step thin ITO surface and the second step ITO was deposited by electron beam evaporator. The total ITO thickness was 250 nm which the first step and second step ITO thickness was 100 nm, 150 nm, respectively. The morphologies of the ITO surface were observed using a scanning electron microscope. The light output powers of the GaN‐based LED with the embedded Al2O3 powder in the ITO was enhanced by ∼20% compared with the conventional LED at 20 mA.

The effects of high temperature (HT) Al‐preseeding process and HT AlN buffer layer on the properties of GaN grown on Si(111) substrates has been investigated. X‐ray diffraction (XRD), transmission electron microscopy (TEM) and photoluminescence (PL) measurement were used to determine the structural and optical properties on the subsequent GaN epilayer. A nearly 2.5 μm, crack‐free GaN epilayer was obtained with a 120‐nm‐thick AlN buffer layer grown at a TMAl source flow rate of 18 μmol/min and an Al‐preseeding time of 5 sec. The near‐band edge emission peak with a full width at half maximum (FWHM) value of 44.93 meV at room temperature (RT) and a (002) X‐ray rocking curve with a 385 arcsec linewidth attests to the high quality of GaN on the Si(111) substrate.

In this paper, we describe the performance elements used in our 28nm bulk devices with the gate first high-k/metal gate scheme for high performance applications. By using the innovative stressor integrations including improved stress memory technique (SMT), optimized embedded SiGe process and dual stress liner, Ieff of ∼540/360 uA/um have been obtained for NMOS and PMOS respectively with the gate length of 28nm and pitch of 113.4nm (Ioff =100 nA/um, Vdd=0.85V). Good Vth mis-match (Avt of ∼2.4 mV-um) has been achieved for SRAM devices with the high-k/metal gate, signal-noise-ratio of ∼0.2V has been demonstrated in the high performance SRAM cell (0.152 um2) with Vdd of 0.85V.

Post gate-etch reoxidation in plasma H 2 /O 2 was successfully employed to non-volatile TANOS charge-trap memory devices without any adverse oxidation on the TaN gate-electrode sidewall. Using this plasma reoxidation process showed significant device improvement in the narrow gate retention and endurance characteristics. This improvement is thought to result from gate etch damage repair, and locally thicker tunnel oxide formation near the gate edge, from the plasma reoxidation process. Circumventing gate etch damage will be indispensable for sub-30nm charge-trap flash memory devices.

The presented theoretical analysis of random telegraph signal (RTS) and 1/f noise data provides consistent interpretation of the measurement results allowing trap characteristics to be extracted and the atomic structure of oxide traps to be identified. We emphasize the critical role of the lattice structural relaxation associated with charge trapping/detrapping, which represents one of the major factors controlling electron capture/emission times.

Tunnel oxide degradation in TANOS devices and its origins were investigated in terms of program, erase, and endurance device operation modes. It was found that the erase operation may cause significant tunnel oxide degradation, while the degradation due to program operation is negligible. In the erase and endurance modes, tunnel oxide degradation is primarily controlled by the process of electron ejection from the SiN trapping layer to the substrate.

In TANOS stuctures in retention, the major decrease in the programmed threshold voltage is found to be caused by the Vt sensing (IdVg measurements) rather than by intrinsic charge loss (when no bias is applied). This Vt decrease can be understood within the process of the temperature-activated charge transport through the Al 2 O 3 blocking oxide. The charge loss can be minimized when Vt sensing time is decreased down to micro seconds. Blocking oxides engineered by adding a thin SiO 2 layer at the SiN/AlO interface demonstrate significant suppression of the charge loss.

A method of evaluating interface states for coupled superlattices has been developed. Explicit solutions for these states have been obtained within the framework of the Kronig–Penney model for the case of two semiconductor superlattices coupled by a tunnel barrier. The interface states are shown to be largely dependent on the coupling strength if the constituent superlattices have identical structure parameters, while insensitive to the tunnel barrier thickness if their structure parameters differ. In the latter case, electrons behave as if the system were composed of two decoupled semi‐infinite superlattices.