1,746 research outputs found
Neurons derived from P19 embryonic carcinoma cells as a platform for biosensor applications - optimisation and characterisation
P19 is a mouse-derived embryonal carcinoma cell line capable of differentiation
toward ectodermal, mesodermal and endodermal lineages and could thus be
differentiated into neurons. Different culture conditions were tested to optimise and
increase the efficiency of neuronal differentiation since the population of P19-derived
neurons was reported to be heterogeneous with respect to the morphology and
neurotransmitters they synthesise. P19-derived neurons were cultured on
microelectrode arrays as cell aggregates and as dissociated cells. Improved neuronal
maturation was shown by the presence of microtubule associated protein 2,
neurofilament and synaptophysin formation when initiation of neuronal differentiation
was prolonged. High initial cell density cultures and coating of surfaces with
polyethylenimine-laminin further improved neuronal maturation of differentiated P19
cells. Increased spontaneous activities of the P19-derived neurons were
correspondingly recorded. Two to three hours recordings were performed between 17
and 25 days when extracellular signals were stabilised. It was found that P19-derived
neurons developed network properties as partially synchronised network activities.
P19-derived neurons appeared to give inhomogenous response to the 2 major
neurotransmitters, -aminobutyric acid (GABA) and glutamate. The P19-derived
neuronal networks obtained from optimised protocol in this thesis were predominantly
GABAergic. The reproducible long term extracellular recordings performed showed
that neurons derived from P19 embryonal carcinoma cells could be applied as a model
for cell based biosensor in corporation with microelectrode arrays
Income mobility of individuals in China and the United States
Though much has been written about annual income inequality in China, little research has been conducted on longer run measures of income inequality and on income mobility. This paper compares income mobility of urban individuals in China and the United States in the 1990s. The following questions are taken up. To what extent are measures of annual income inequality misleading indicators of long-run income inequality? How much income mobility was there in China in the first half of the 1990s and how did this compare with mobility in other countries? Have real income increases been greater for the poor or the rich? How important is the variation in permanent incomes in China and how has this changed
Mechanisms Of Fracturing In Structures Built From Topologically Interlocked Blocks
Failure of materials is in many cases associated with initiation and subsequent propagation of macroscopic fractures. Consequently, in order to increase the strength, one needs to inhibit either crack initiation or propagation. The principle of topological interlocking provides a unique opportunity to construct materials and structures in which both routes of the strength increase can be realised. Materials and structures built on the basis of this principle consist of many elements which are hold together by the special geometry of their shape, together with an external constrain. The absence of the binder phase between the elements allows the interfaces to arrest macroscopic crack propagation. In addition, with sufficiently small size of the elements an increase in local strength and, possibly, in the stress for crack initiation can be achieved by capitalising on the size effect. Furthermore, the ability of some interlocking structures to tolerate missing elements can serve to prevent the avalanche-type failure initiated by failure of one of the elements. In this paper, experimental results and a theoretical analysis with regard to this possibility are presented
Peroxidase extraction from jicama skin peels for phenol removal
Phenol and its derivatives exist in various types of industrial effluents, and are known to be harmful to aquatic lives even at low concentrations. Conventional treatment technologies for phenol removal are challenged with long retention time, high energy consumption and process cost. Enzymatic treatment has emerged as an alternative technology for phenol removal from wastewater. These enzymes interact with aromatic compounds including phenols in the presence of hydrogen peroxide, forming free radicals which polymerize spontaneously to produce insoluble phenolic polymers. This work aims to extract peroxidase from agricultural wastes materials and establish its application for phenol removal. Peroxidase was extracted from jicama skin peels under varying extraction conditions of pH, sample-to-buffer ratio (w/v %) and temperature. Experimental results showed that extraction process conducted at pH 10, 40% w/v and 25oC demonstrated a peroxidase activity of 0.79 U/mL. Elevated temperatures slightly enhanced the peroxidase activities. Jicama peroxidase extracted at optimum extraction conditions demonstrated a phenol removal efficiency of 87.5% at pH 7. Phenol removal efficiency was ∼ 97% in the range of 30 - 40oC, and H2O2 dosage has to be kept below 100 mM for maximum removal under phenol concentration tested
A multi-lesional analysis of diffuse idiopathic pulmonary neuroendocrine cell hyperplasia:a single-centre analysis
AIM: To conduct a multi-lesional computed tomography (CT) analysis of diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) patients to determine volumetric changes in lesions over 5 years.MATERIALS AND METHODS: A retrospective case-note review was undertaken to identify 16 patients with histological and radiological features of DIPNECH between 2012-2021. Area and volume were calculated for 17 sets of lesions identified on high-resolution CT. Clinical data were extracted from electronic patient records, which included demographic data, outpatient clinic letters, histology reports, and imaging reports.RESULTS: One hundred and twenty-eight lesions were identified in 16 patients (one male, 15 female) and followed-up annually over a median 1,985 days (range 1,450-2,290). At year 1 follow-up, lesion area ranged from 1-48 mm2, and lesion volume ranged from 8-18,380 mm3; lesion area ranged from 1-45mm2 and lesion volume ranged from 11-17,800 mm3 and year 5. Half (8/16) of the patients had concomitant typical carcinoid tumours and one patient had an atypical carcinoid tumour. No statistically significant correlation (p<0.05) was found between lesion cross-sectional area or volume and duration of follow-up (years and days). No metastatic spread was observed at the time of analysis.CONCLUSIONS: No significant increase was observed in the size of over 100 lesions in patients with DIPNECH over a 5-year period and no metastasis occurred during the study period affirming the relatively indolent course of the disease.</p
An Evolutionary Algorithm with Advanced Goal and Priority Specification for Multi-objective Optimization
This paper presents an evolutionary algorithm with a new goal-sequence
domination scheme for better decision support in multi-objective optimization.
The approach allows the inclusion of advanced hard/soft priority and constraint
information on each objective component, and is capable of incorporating
multiple specifications with overlapping or non-overlapping objective functions
via logical 'OR' and 'AND' connectives to drive the search towards multiple
regions of trade-off. In addition, we propose a dynamic sharing scheme that is
simple and adaptively estimated according to the on-line population
distribution without needing any a priori parameter setting. Each feature in
the proposed algorithm is examined to show its respective contribution, and the
performance of the algorithm is compared with other evolutionary optimization
methods. It is shown that the proposed algorithm has performed well in the
diversity of evolutionary search and uniform distribution of non-dominated
individuals along the final trade-offs, without significant computational
effort. The algorithm is also applied to the design optimization of a practical
servo control system for hard disk drives with a single voice-coil-motor
actuator. Results of the evolutionary designed servo control system show a
superior closed-loop performance compared to classical PID or RPT approaches
Important Parameters for Hand Function Assessment of Stroke Patients
Clinical scales such as Fugl-Meyer Assessment and Motor Assessment Scale are widely used to evaluate stroke patient's motor performance. However, the scoring systems of these assessments provide only rough estimation, making it difficult to objectively quantify impairment and disability or even rehabilitation progress throughout their rehabilitation period. In contrast, robot-based assessments are objective, repeatable, and could potentially reduce the assessment time. However, robot-based assessment scales are not as well established as conventional assessment scale and the correlation to conventional assessment scale is unclear. This paper discusses the important parameters in order to assess the hand function of stroke patients. This knowledge will provide a contribution to the development of a new robot-based assessment device effectively by including the important parameters in the device. The important parameters were included in development of iRest and yielded promising results that illustrate the potential of the important parameters in assessing the hand function of stroke patients
Myocardial collagen deposition and inflammatory cell infiltration in cats with pre-clinical hypertrophic cardiomyopathy
The histological features of feline hypertrophic cardiomyopathy (HCM) have been well documented, but there are no reports describing the histological features in mild pre-clinical disease, since cats are rarely screened for the disease in the early stages before clinical signs are apparent. Histological changes at the early stage of the disease in pre-clinical cats could contribute to an improved understanding of disease aetiology or progression. The aim of this study was to evaluate the histological features of HCM in the left ventricular (LV) myocardium of cats diagnosed with pre-clinical HCM. Clinically healthy cats with normal (n = 11) and pre-clinical HCM (n = 6) were identified on the basis of echocardiography; LV free wall dimensions (LVFWd) and/or interventricular septal wall (IVSd) dimensions during diastole of 6–7 mm were defined as HCM, while equivalent dimension
Packaging Improvement for Unit Cell Vanadium Redox Flow Battery (V-RFB)
Packaging for vanadium redox flow battery is one of the key elements for successful implementation of flow battery in the electrical energy storage system. Usually the bulky battery size and low energy densities make this technology not available for mobility application. Therefore RFB with improved packaging size and energy capacity are highly desirable. This paper focuses on the study of packaging improvement for unit cell V-RFB to the application on Series Hybrid Electric Vehicle. Two different designs of 25 cm2 and 100 cm2 unit cell V-RFB at same current density are used for the sample in this investigation. Further suggestions on packaging improvement are highlighted
- …