The Effects of Annealing Temperatures on Composition and Strain in SixGe1?x Obtained by Melting Growth of Electrodeposited Ge on Si (100)

The effects of annealing temperatures on composition and strain in Si_xGe_1−x, obtained by rapid melting growth of electrodeposited Ge on Si (100) substrate were investigated. Here, a rapid melting process was performed at temperatures of 1000, 1050 and 1100°C for 1 s. All annealed samples show single crystalline structure in (100) orientation. A significant appearance of Si-Ge vibration mode peak at ~00 cm⁻¹ confirms the existence of Si-Ge intermixing due to out-diffusion of Si into Ge region. On a rapid melting process, Ge melts and reaches the thermal equilibrium in short time. Si at Ge/Si interface begins to dissolve once in contact with the molten Ge to produce Si-Ge intermixing. The Si fraction in Si-Ge intermixing was calculated by taking into account the intensity ratio of Ge-Ge and Si-Ge vibration mode peaks and was found to increase with the annealing temperatures. It is found that the strain turns from tensile to compressive as the annealing temperature increases. The Si fraction dependent thermal expansion coefficient of Si_xGe_1−x is a possible cause to generate such strain behavior. The understanding of compositional and strain characteristics is important in Ge/Si heterostructure as these properties seem to give significant effects in device performance.     

Role of Sintering Temperature in Production of Nepheline Ceramics-Based Geopolymer with Addition of Ultra-High Molecular Weight Polyethylene

The primary motivation of developing ceramic materials using geopolymer method is to minimize the reliance on high sintering temperatures. The ultra-high molecular weight polyethylene (UHMWPE) was added as binder and reinforces the nepheline ceramics based geopolymer. The samples were sintered at 900 °C, 1000 °C, 1100 °C, and 1200 °C to elucidate the influence of sintering on the physical and microstructural properties. The results indicated that a maximum flexural strength of 92 MPa is attainable once the samples are used to be sintered at 1200 °C. It was also determined that the density, porosity, volumetric shrinkage, and water absorption of the samples also affected by the sintering due to the change of microstructure and crystallinity. The IR spectra reveal that the band at around 1400 cm⁻¹ becomes weak, indicating that sodium carbonate decomposed and began to react with the silica and alumina released from gels to form nepheline phases. The sintering process influence in the development of the final microstructure thus improving the properties of the ceramic materials.     

Men suffer more complications from diabetes than women despite similar glycaemic control and a better cardiovascular risk profile: the ADCM study 2008

BackgroundGender differences in glycaemic control and diabetes’ complications have been well studied overseas but not locally. Gender is one of the non-modifiable factors for the diabetes patient but it is an important factor for effective personalized diabetes care. This paper examined the gender differences in glycaemic control and diabetes’ complications.MethodsThis was a registry-based observational study from May–December 2008. An online standard case record form was available for site data providers to register their diabetes patients aged 18 years old and above annually. Demographic data, diabetes duration, treatment modalities, as well as various risk factors and diabetes complications were reported. Multivariate analysis was performed.ResultsA total of 20,646 diabetes patients were included. The majority (99.2%) had been diagnosed with type 2 diabetes mellitus (T2D); 42.8% of the sample were men; 57.1% were Malay. The mean age was 58.0 years (standard deviation (SD) = 11.49) with 77.6% of the sample being 50 years old and above. Despite similar diabetes control (HbA1c < 6.5%), females suffered more microvascular complications (estimated glomerular filtration rate (eGFR) <60 mls/min: X² = 753.54, P = <0.001) while men suffered more from macrovascular complications (ischaemic heart disease (X² = 57.61, P = <0.001) and stroke (X² = 13.87, P = <0.001)). Multivariate logistic regression analyses showed that T2D men were more likely to suffer from stroke (odds ratio (OR) = 1.21, 95% confidence interval (CI) = 0.89–1.64), ischaemic heart disease (OR = 1.55, CI = 1.35–1.78) and nephropathy (OR = 1.59, CI = 1.44–1.75).ConclusionWe observed that men suffered more diabetes-related complications despite similar glycaemic control and better risk factor control. This finding requires further verification from future studies.     

Crystallization of Electrodeposited Germanium Thin Film on Silicon (100)

We report the crystallization of electrodeposited germanium (Ge) thin films on n-silicon (Si) (100) by rapid melting process. The electrodeposition was carried out in germanium (IV) chloride: propylene glycol (GeCl₄:C₃H₈O₂) electrolyte with constant current of 50 mA for 30 min. The measured Raman spectra and electron backscattering diffraction (EBSD) images show that the as-deposited Ge thin film was amorphous. The crystallization of deposited Ge was achieved by rapid thermal annealing (RTA) at 980 °C for 1 s. The EBSD images confirm that the orientations of the annealed Ge are similar to that of the Si substrate. The highly intense peak of Raman spectra at 300 cm⁻¹ corresponding to Ge-Ge vibration mode was observed, indicating good crystal quality of Ge. An additional sub peak near to 390 cm⁻¹ corresponding to the Si-Ge vibration mode was also observed, indicating the Ge-Si mixing at Ge/Si interface. Auger electron spectroscopy (AES) reveals that the intermixing depth was around 60 nm. The calculated Si fraction from Raman spectra was found to be in good agreement with the value estimated from Ge-Si equilibrium phase diagram. The proposed technique is expected to be an effective way to crystallize Ge films for various device applications as well as to create strain at the Ge-Si interface for enhancement of mobility.     

Diagnostic evaluation of optical coherence tomography parameters in normal, preperimetric and perimetric glaucoma patients

AIM: To compare the diagnostic ability of glaucoma parameters measured by the optical coherence tomography (OCT) in normal, preperimetric glaucoma (PPG) and perimetric glaucoma (PG) patients. METHODS: This cross-sectional observational study includes 127 eyes of 127 subjects. Patients were divided into PPG (51 eyes), PG (46 eyes), and normal controls (30 eyes) based on clinical optic disc assessment and Humphrey visual field changes. The Heidelberg Spectralis OCT machine using Glaucoma Module Premium Edition software was used to measure the retinal nerve fiber layer (RNFL) and Bruch’s membrane opening-minimum rim width (BMO-MRW) to assess the optic nerve head and ganglion cell layer (GCL) thickness in the macula. RESULTS: RNFL, MRW, and GCL thickness were all significantly thinner in PG compared to PPG and the normal group. The BMO-MRW parameters showed better specificity (>70%) at 90% specificity compared to both RNFL and GCL parameters to discriminate normal, PPG, and PG patients. All BMO-MRW parameters showed higher area under curves (AUC) compared to RNFL and GCL parameters with the highest AUC observed in the superotemporal sector of the BMO-MRW (AUC=0.819 and and 0.897 between normal and PPG and PG groups respectively). CONCLUSION: While the BMO-MRW best discriminates PPG and PG against normal eyes, GCL parameters poorly differentiate the three groups.     

Inflammatory complications of CGRP monoclonal antibodies: a case series

BackgroundCalcitonin gene-related peptide (CGRP) is expressed throughout the body and is a known mediator of migraine, exerting this biological effect through activation of trigeminovascular, meningeal and associated neuronal pathways located in close proximity to the central nervous system. Monoclonal antibodies (mAb) targeting the CGRP pathway are an effective new preventive treatment for migraine, with a generally favourable adverse event profile. Pre-clinical evidence supports an anti-inflammatory/immunoregulatory role for CGRP in other organ systems, and therefore inhibition of the normal action of this peptide may promote a pro-inflammatory response.CasesWe present a case series of eight patients with new or significantly worsened inflammatory pathology in close temporal association with the commencement of CGRP mAb therapy.ConclusionThis case series provides novel insights on the potential molecular mechanisms and side-effects of CGRP antagonism in migraine and supports clinical vigilance in patient care going forward.     

The Buffering analysis to identify common geographical factors within the vicinity of severe injury related to motor vehicle crash in Malaysia

BACKGROUND: The main objective was to identify common geographical buildup within the 100-meter buffer of severely injured based on injury severity score (ISS) among the motor vehicle crash (MVC) victims in Malaysia.METHODS: This was a prospective cohort study from July 2011 until June 2013 and involved all MVC patients attending emergency departments (ED) of two tertiary centers in a district in Malaysia. A set of digital maps was obtained from the Town Planning Unit of the district Municipal Office (local district map). Vector spaces were spanned over these maps using GIS software (ARCGIS 10.1 licensed to the study center), and data from the identified severe injured cases based on ISS of 16 or more were added. Buffer analysis was performed and included all events occurring within a 100 -meter perimeter around a reference point.RESULTS: A total of 439 cases were recruited over the ten-month data collection period. Fifty two (11%) of the cases were categorized as severe cased based on ISS scoring of 16 and more. Further buffer analysis looking at the buildup areas within the vicinity of the severely injured locations showed that most of the severe injuries occurred at locations on municipal roads (15, 29%), straight roads (16, 30%) and within villages buildup (suburban) areas (18, 35%).CONCLUSION: This study has successfully achieved its objective in identifying common geographical factors and buildup areas within the vicinity of severely injured road traffic cases.