196 research outputs found

    Primary squamous cell carcinoma of the rectum: a case report

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    Squamous cell carcinoma of the rectum is a very rare malignancy. In the literature, the incidence has been reported as 0.25 to 0.1 per 10000 colorectal carcinomas. Due to its rarity, the treatment and behavior of this tumor have only been discussed in case reports. As a result, several theories regarding their pathogenesis have been proposed. We will describe our experience in managing this rare malignancy in a 69-year-old man who presented with altered bowel habit. Surgery remains the mainstay of treatment. Issues regarding additional treatment have been presented in the literature. The rarity of this tumour also raises issues regarding criteria for diagnosis which we will try to highlight and discuss

    Time-domain estimation of acoustic radiation modes and active structural acoustic control

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    This paper presents a method of calculating the radiated sound power of vibrating structures based on the time domain estimation of acoustic radiation modes (ARMs). Each ARM is frequency-dependent, radiates power independent of the other ARMs and can be estimated in the time domain from measurements made at discrete sensor locations on the surface of the radiating structure. The individual ARM components are estimated digitally in the time domain using finite impulse response filters, which are designed to provide a best weighted fit to the ARMs in the frequency domain. The ARM amplitudes are estimated by filtering the vectors of measured velocities at points on the radiating surface with these ARM filters, before summing the product of the square of these amplitudes with the relevant eigenvalues to estimate the radiated sound power. The method is described with reference to a simply supported beam model. The results show that the sound power calculated from the proposed approach and from a frequency domain approach are comparable. Finally, a time domain feedforward active structural acoustic control system developed using the proposed method is presented and time domain simulations demonstrate the performance of the system

    Adaptive control of radiated sound power based on time-domain estimates of acoustic radiation modes

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    In active structural acoustic control, broadband control of the radiated sound power from a structure can be achieved by minimizing the amplitudes of the acoustic radiation modes (ARMs). The shape of these ARMs is frequency dependent and only a few might radiate significant power in a given frequency range. In this paper a method is described by which the ARMs are estimated in real-time from a number of point response measurements taken on a vibrating structure. These estimates can be used to calculate the radiated power or, here, in a feedforward adaptive control system. Estimates of the ARM amplitudes in the time domain are produced by digitally filtering the outputs of an array of sensors mounted on the radiator. These filters are designed by FIR filters in the frequency domain based on the frequency-dependent ARMs and implemented in the time domain. These estimates are then used as the cost function in a feedforward, adaptive, filtered-X LMS controller. The theory is described with reference to a 2-dimensional vibrating structure. Finally numerical results of real-time simulations are presented

    Identification and characterization of the lactic acid bacteria isolated from Malaysian fermented fish (Pekasam)

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    Recently researchers are interested with the biotherapeutic potential of probiotics in gut disease treatment. The bacteria are generally regarded as a safe, have a stability of usage and originate from the natural resources. The study aims to identify and characterize the potential probiotic Lactic Acid Bacteria (LAB) isolated from Malaysian fermented fish product known as Pekasam. Fourty isolates obtained were firstly screened for their antagonism activities against the common pathogenic bacteria; Esherichia coli, Staphylococcus aureus and Klebsiella sp. Our study revealed only three (labeled as L8, L20 and S1) of the isolates tested showed broad antimicrobial effects towards the pathogenic bacteria. All of the isolates were also γ-hemolytic and tolerant to various pH (pH 3, 5 and 7.5) and 0.3% (w/v) bile salts. The bacteria isolates of strain L8 and L20 were susceptible to seven antibiotics tested except vancomycin and tetracycline whereas S1 was resistant to all antibiotics. Phenotypic tests revealed that both bacteria isolates of strain L8 and L20 were Bacillus megaterium while S1 was Pediococcus pentosaceus whereas 16S rRNA gene sequence analysis showed potential bacteria isolates of strain L8 and L20 belonged to the Lactobacillus plantarum (99% similarity) and S1 was characterized as Lactobacillus pentosus (100% similarity) respectively. Our present study showed that the probiotics of strain L8, L20 and S1 isolated from the fermented fish (Pekasam) exhibited the potential probiotic properties to be developed as biotherapeutic agents

    Comparison between conventional and microwave-assisted hydrodistillation methods towards extraction of essential oils from Murraya koenigii (Curry leaves)

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    Study on the extraction of essential oils from leaves of Murraya koenigii had been carried out by conventional hydrodistillation (HD) and microwave-assisted hydrodistillation (MAHD) methods. Time of the first oil droplet, percentage yield of the extracted oils and the chemical components of the extracted essential oils from both methods were compared. The running time for MAHD was set at one and half hour while running time for HD was 5 hours. The major components from the essential oils obtained from HD method were β-copaene (41.5%), α-selinene (10.0%) and α-humulene (8.4%). Meanwhile, major chemical components extracted from MAHD method were β-caryophyllene (19.5%), terpine-4-ol (17.6%) and linalool (9.8%). A total of 79.6% of chemical components were identified from essential oil extracted through HD method while MAHD method was 75.7%. The first oil droplet for HD method was found to be at 34 minutes and 20 minutes for MAHD method. MAHD is more preferable method for extracting essential oils from Murraya koenigii as it provides high extraction efficiency with less time taken

    A review on anticipatory grief and lessons learnt from the history of Abu Bakr r.a.

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    Grief is defined as ‘the internal experience of a person to the loss of something loved and valued’. It is a normal and expected reaction to loss. While anticipatory grief is defined as ‘an emotional response that is experienced before a true loss’, a concept focusing on that a person might experience grief when the loss of a close loved one was anticipated, but had not yet occurred. The history of Abu Bakr r.a. was reviewed especially from the period of a few months before and recently after the death of the prophet s.a.w. It was noted that he appeared strong while others were down grieving upon the news of the prophet s.a.w.’s death. It was also noted that Abu Bakr r.a. has been grieving when he anticipated that the prophet was going to die. Literatures on anticipatory grief were reviewed. Evidence are conflicting on the role of anticipatory grief. Factors that lead to these differences will be reviewed. The protective factors in Abu Bakr r.a. that helped maintain his composure after the death of prophet Muhammad s.a.w. and later led him to be pledged as the first caliph of the Muslim nation will be discussed

    Electrons Extraction from MWCNT/PEO Composites

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    Electron field emission was investigated from multi-walled carbon nanotubes (MWCNT)/polyethylene oxide (PEO) composites with (5, 15, 25, 33, 40 and 50wt.% of MWCNTs). The resulted samples were characterized using Raman spectroscopy to estimate The MWCNTs-PEO (Nanotubes-Polymer) interaction through the shifting or width alteration of the peaks. The SEM micrographs were issued to investigate the surface morphology of the samples. In addition, and in order to gain additional understanding of the filler content and the samples thermal stability; the TGA technique was applied. The current density versus applied electric field J(E) and current stability of the prepared composites were measured using a range of voltages. Here, the 33wt.% composite displayed the lowest turn on field of 6.51V/μm, whereas the highest current density achieved was 1.17mA/cm2 by the 40wt.% composite

    Percentage of haemoglobin variants detected during HbA1c analysis in Hospital Kuala Lumpur

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    HbA1c is an established index of glycaemic control and correlates strongly with risk of chronic diabetic complications. However, the accuracy of HbA1c measurement can be affected by many factors, among which is the presence of haemoglobin (Hb) variants. The aim of the study was to determine the percentage of Hb variant detected during HbA1c monitoring in Hospital Kuala Lumpur. The study also analysed non-reportable HbA1c results in the presence of Hb variants. A cross-sectional study using retrospective data of HbA1c results over five months’ period was analysed on Biorad Variant II Turbo, a high performance liquid chromatography (HPLC) assay. The Hb variants were grouped either as HbS, HbC, others (Hb variant apart from HbS or C), and a combination of HbS or C with Others. A total of 11,904 patients were included. Only 2.3% (273) had Hb variants; HbS trait (10.3%), others (89%), and the combination of HbS trait with others (0.7%). No patient with HbC variant or its combination was found. Only 2.2% of those with Hb variant had non-reportable HbA1c. Although the percentage of Hb variants detected during HbA1c analysis and non-reportable HbA1c results were low, their presence should be noted

    Effect of food density on male appearance and ephippia production in a tropical cladoceran, Moina micrura Kurz, 1874

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    A study was conducted to investigate the effects of different food concentrations consisting of Nannochloropsis oculata (4 × 102, 4 × 104, 4 × 106 cells ml− 1 and control) on male and ephippia production in a tropical cladoceran, Moina micrura. The highest number of males (186.7 ± 13.4 males l− 1) was produced in cultures fed with 4 × 102 cells ml− 1 of N. oculata (FC 3) when the population density reached > 1600 individuals l− 1. Similarly, the highest total mean number of ephippia (160.0 ± 0.0 ephippia l− 1) was achieved in M. micrura culture supplied with 4 × 102 cells ml− 1 of N. oculata (FC 3). The second highest ephippia density was found in M. micrura cultures fed with 4 × 104 cells ml− 1 of N. oculata (FC 2) which produced a mean total of 93.3 ± 13.4 ephippia l− 1 in a population density of > 3000 individuals l− 1. However, with a population density of > 4000 individuals l− 1, but fed with the highest food concentration of 4 × 106 cells ml− 1 N. oculata (FC 1), no ephippia was produced although males were present in the culture. This study illustrates that ephippia were produced in high density cultures with the presence of males and insufficient food supply. Crowding could trigger the production of males, but was not an adequate stress factor for inducing the formation of ephippia. Similarly, food limitation alone did not induce the production of males and ephippia without crowding
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