A framework for the analysis of the security of supply of utilising carbon dioxide as a chemical feedstock

Recent developments in catalysts have enhanced the potential for the utilisation of carbon dioxide as a chemical feedstock. Using the appropriate energy efficient catalyst enables a range of chemical pathways leading to desirable products. In doing so, CO2 provides an economically and environmentally beneficial source of C1 feedstock, while improving the issues relating to security of supply that are associated with fossil-based feedstocks. However, the dependence on catalysts brings other supply chains into consideration, supply chains that may also have security of supply issues. The choice of chemical pathways for specific products will therefore entail an assessment not only of economic factors but also the security of supply issues for the catalysts. This is a multi-criteria decision making problem. In this paper, we present a modified 4A framework based on the framework suggested by the Asian Pacific Energy Research centre for macro-economic applications. The 4A methodology is named after the criteria used to compare alternatives: availability, acceptability, applicability and affordability. We have adapted this framework for the consideration of alternative chemical reaction processes using a micro-economic outlook. Data from a number of sources were collected and used to quantify each of the 4A criteria. A graphical representation of the assessments is used to support the decision maker in comparing alternatives. The framework not only allows for the comparison of processes but also highlights current limitations in the CCU processes. The framework presented can be used by a variety of stakeholders, including regulators, investors, and process industries, with the aim of identifying promising routes within a broader multi-criteria decision making process

Diffusion tensor-based fiber tracking in cervical spinal cord with a 3T MRI

The protocol for spinal DTI nntl tractography with high SNR and spatial resolution has been developed arid tested on G healthy subjects and 1 CSM patient in a 3T system. Fiber bundlex were traced and were found running parallel to the cervical spinal cord correlating with the neuronal anatomy in normal subjects. The FA maps showed consistent low FA region connecting all spinal levels, which corresponded lo the grey matter structure in anatomical imaging, Spinal DTI in CSM showed diffusivity increase at compression sites. The proposed diffusion eigenvector-based method was able to differentiate between λa and λr even when there was a draxtic diffusivity change at compressed regions in CSM, which may facilitate better understanding of the pathophysiology of CSM. Our results indicated that using the current imaging and post-procensing protocols, spinal DTI can fm achieved with better grey white matter contrast, high inter-subject reproducibility and diagnostic ability. © 2006 IEEE.published_or_final_versio

Proton Density-weighted Spinal fMRI Comparison between Sensorimotor Task and Acupoint Stimulation

Proton density-weighted fMRI studies have been carried out in spinal cord in the current study. We compared the spinal cord activation produced by handgripping sensorimotor task and electro-acupuncture stimulation. Activation was detected in both cases localized at spinal levels C6-C7 (11/14 in sensorimotor and 7/11 in acupuncture stimulation). It was observed that the amount of activation in sensorimotor task was in general greater than in electroacupuncture stimulation. The percentage signal changes were found to be similar. Our results indicate that proton density-weighted fMRI in low field MRI system can be used for sensorimotor and acupuncture pathway research.published_or_final_versio

Functional MRI of the spinal cord at low field

A second contrast mechanism SEEP was reported to co-exist with BOLD during fMRI activation. The mechanism was based on the task-induced signal change of extravascular water protons and was primarily shown in the spinal cord at high field. Recently, a preliminary study was reported at 0.2T showing SEEP contrast in the brain while the BOLD effect was negligible. The present study is to investigate the presence of SEEP in the spinal cord at 0.2T using proton density-weighted imaging with motor task. Bilateral activations were obtained in the anterior grey horns consistently across C6-C8 levels, which correlated with the neural anatomy.published_or_final_versio

Detection of ipsilateral and contralateral activation components in unilateral fingers-tapping using spinal BOLD fMR

Ipsilateral activation component has been reported in brain fMRI studies using unilateral finger motion. However, the ipsilateral component is usually taskdependent and sparsely distributed. In this study, spinal BOLD fMRI has been performed on 4 healthy right-handed volunteers performing unilateral fingerstapping to investigate the ipsilateral and contralateral activation inside the cervical spinal cord. Our results showed that more activation were found at the spinal level C5-C6/C7. Bilateral activation was observed in all subjects both in left/right hand fingers-tapping. Spinal fMRI was sensitive to detect bilateral firing in fingers-tapping using dominant or non-dominant hands.published_or_final_versio

Prevalence and awareness of lower urinary tract symptoms among males in the Outpatient Clinics of Universiti Kebangsaan Malaysia Medical Centre.

This study aims to determine the prevalence of lower urinary tract symptoms (LUTS) and level of awareness among male outpatients in Universiti Kebangsaan Malaysia Medical Centre (UKMMC). A questionnaire consisting of demographic data, questions related to knowledge, attitude and practice on BPH and the International Prostate Symptom Score (IPSS) was used for this study. Uroflowmetry and bladder scan were used to evaluate the function of the urinary tract and severity of BPH. Urine dipstick was done for glycosuria, proteinuria and haematuria. A total of 220 respondents were surveyed. The prevalence of moderately and severely symptomatic LUTS was 42.7%. The most commonly reported LUTS were nocturia (78.2%), frequency (58.2%) and incomplete emptying (44.6%). The prevalence of glycosuria, proteinuria and haematuria were 23.6%, 11.4% and 1.8% respectively. There was a significant association between increasing age with the severity of LUTS (p=0.005). Out of 102 respondents with voided urine volume greater than 150 mL, there was a significant decrease in maximum (Qmax) (p=0.039) and average (Qave) urine flow rates with every 10 years increase of age (p=0.001). The majority of respondents (59.5%) have heard of BPH before. Over 78.2% of the respondents would seek medical attention if they have LUTS with 15.9% saying they would seek traditional treatment. In conclusion, the prevalence of LUTS was high and the level of awareness was satisfactory

VEGF(164)-mediated inflammation is required for pathological, but not physiological, ischemia-induced retinal neovascularization

Hypoxia-induced VEGF governs both physiological retinal vascular development and pathological retinal neovascularization. In the current paper, the mechanisms of physiological and pathological neovascularization are compared and contrasted. During pathological neovascularization, both the absolute and relative expression levels for VEGF(164) increased to a greater degree than during physiological neovascularization. Furthermore, extensive leukocyte adhesion was observed at the leading edge of pathological, but not physiological, neovascularization. When a VEGF(164)-specific neutralizing aptamer was administered, it potently suppressed the leukocyte adhesion and pathological neovascularization, whereas it had little or no effect on physiological neovascularization. In parallel experiments, genetically altered VEGF(164)-deficient (VEGF(120/188)) mice exhibited no difference in physiological neovascularization when compared with wild-type (VEGF(+/+)) controls. In contrast, administration of a VEGFk-1/Fc fusion protein, which blocks all VEGF isoforms, led to significant suppression of both pathological and physiological neovascularization. In addition, the targeted inactivation of monocyte lineage cells with clodronate-liposomes led to the suppression of pathological neovascularization. Conversely, the blockade of T lymphocyte-mediated immune responses with an anti-CD2 antibody exacerbated pathological neovascularization. These data highlight important molecular and cellular differences between physiological and pathological retinal neovascularization. During pathological neovascularization, VEGF(164) selectively induces inflammation and cellular immunity. These processes provide positive and negative angiogenic regulation, respectively. Together, new therapeutic approaches for selectively targeting pathological, but not physiological, retinal neovascularization are outlined

Study of myocardial fiber length distribution with diffusion tensor MRI

Diffusion tensor MRI (DTI) is a nondestructive method to map myocardial fiber organization. Many studies have been done on myocardial fiber orientation. However, cardiac contraction is also related with myocardial fiber length, but its study is limited so far. The current study aims to provide information of myocardial fiber length distribution in formalin-fixed porcine heart samples. DTI with medium diffusion resolution (15 directions) was performed. Fiber length distribution as a function of fiber helix angle was investigated in multiple short-axis slices located from base to apex of the left ventricles. Results show that longer fibers likely run circumferentially, and fibers located at middle and upper ventricle are generally longer than those near apex. The results provide supplementary structural information on myocardial fiber architecture and cardiac mechanics.published_or_final_versio

Asymptomatic members with SOD1 mutation in a large kindred with familial amyotrophic lateral sclerosis have abnormal water diffusion characterisitcs

DTI was carried out in FALS/SALS patients and familial members with SOD1 mutation (AFALS) who may be in a pre-symptomatic phase of ALS. The changes in FA and TT were investigated in CBT/CST and in whole brain. In FALS/SALS, diffusion pattern changes were found in cerebral peduncle, internal capsule, sub-cortical white matter, cerebellum and frontal lobe while in AFALS, abnormal pattern could also be detected in the cerebral peduncle, cerebellum and frontal lobe but with a smaller extent. Our study indicates that DTI can show early diffusion changes in members with SOD1 mutation in FALS prior to symptom-onset.published_or_final_versio

DeepBrain: Functional Representation of Neural In-Situ Hybridization Images for Gene Ontology Classification Using Deep Convolutional Autoencoders

This paper presents a novel deep learning-based method for learning a functional representation of mammalian neural images. The method uses a deep convolutional denoising autoencoder (CDAE) for generating an invariant, compact representation of in situ hybridization (ISH) images. While most existing methods for bio-imaging analysis were not developed to handle images with highly complex anatomical structures, the results presented in this paper show that functional representation extracted by CDAE can help learn features of functional gene ontology categories for their classification in a highly accurate manner. Using this CDAE representation, our method outperforms the previous state-of-the-art classification rate, by improving the average AUC from 0.92 to 0.98, i.e., achieving 75% reduction in error. The method operates on input images that were downsampled significantly with respect to the original ones to make it computationally feasible