An air-wedge lateral-shear interferometer using two prisms is presented. With a variable shear, the interferometer is suitable for testing collimation of a wide range of beam sizes down to a few millimeters in diameter. No antireflection coatings are necessary. Collimation for a light source with short coherent length is also demonstrated.
This paper investigated the static behaviour of glass fibre reinforced polymer (GFRP) built-up hollow and concrete filled built-up beams tested under four-point bending with a span-to-depth ratio of 1.67, therefore focusing their shear performance. Two parameters considered for hollow sections were longitudinal web stiffener and strengthening at the web-flange junction. The experimental results indicated that the GFRP hollow beams failed by web crushing at supports; therefore, the longitudinal web stiffener has an insignificant effect on improving the maximum load. Strengthening web-flange junctions using rectangular hollow sections increased the maximum load by 47%. Concrete infill could effectively prevent the web crushing, and it demonstrated the highest load increment of 162%. The concrete filled GFRP composite beam failed by diagonal tension in the lightweight concrete core. The finite element models adopting Hashin damage criteria yielded are in good agreement with the experimental results in terms of maximum load and failure mode. Based on the numerical study, the longitudinal web stiffener could prevent the web buckling of the slender GFRP beam and improved the maximum load by 136%. The maximum load may be further improved by increasing the thickness of the GFRP section and the size of rectangular hollow sections used for strengthening. It was found that the bond-slip at the concrete-GFRP interface affected the shear resistance of concrete-GFRP composite beam.
We give details about how a surface plasmons with phase singularities can be produced when a Bessel beam light is totally reflected internally at the planar surface of a dielectric on which an infinitesimally thin film has been deposited. The characteristic property of such a light is the exponential decay with distance in a vacuum which can basically provide a two-dimensional surface plasmons with phase singularities with attractive enhancements. Such a phenomenon is governable by altering the incident angle and the order of the Bessel beam.
In Industrial systems, Supervisory control and data acquisition (SCADA) system, the pseudo-transport layer of the distributed network protocol (DNP3) performs the functions of the transport layer and network layer of the open systems interconnection (OSI) model. This study used a simulation design of water pumping system, in-which the network nodes are directly and wirelessly connected with sensors, and are monitored by the main controller, as part of the wireless SCADA system. This study also intends to focus on the security issues inherent in the pseudo-transport layer of the DNP3 protocol. During disassembly and reassembling processes, the pseudo-transport layer keeps track of the bytes sequence. However, no mechanism is available that can verify the message or maintain the integrity of the bytes in the bytes received/transmitted from/to the data link layer or in the send/respond from the main controller/sensors. To properly and sequentially keep track of the bytes, a mechanism is required that can perform verification while bytes are received/transmitted from/to the lower layer of the DNP3 protocol or the send/respond to/from field sensors. For security and byte verification purposes, a mechanism needs to be proposed for the pseudo-transport layer, by employing cryptography algorithm. A dynamic choice security buffer (SB) is designed and employed during the security development. To achieve the desired goals of the proposed study, a pseudo-transport layer stack model is designed using the DNP3 protocol open library and the security is deployed and tested, without changing the original design.
Tujuan kajian ini adalah untuk menerokai kaedah pembantu penanda permukaan terhadap implan orbital untuk pembedahan tulang orbit. Enam tengkorak manusia dewasa kering telah digunakan dalam kajian ini. Implan orbital aluminium yang disediakan secara individu, dengan ketebalan 0.4 mm disediakan untuk lantai orbit secara bilateral. Empat penanda permukaan implan fizikal dari aspek anterior dan posterior implan yang disediakan dan diimbas secara optik. Pemeriksaan pra-pembedahan tomografi berkomputer ‘cone-beam’ (CBCT) diperolehi untuk semua lantai orbit. Data 'Digital Imaging and Communications in Medicine' (DICOM) tengkorak diambil, diimport dan direka bentuk dengan format data stereolithografi (STL) implan orbital masing-masing menggunakan iPlan CMF (Versi 3.0, BrainLab, Jerman). Teknik gabungan imej dilakukan untuk setiap tengkorak selepas pembinaan semula dengan pengambilan pos-pembedahan CBCT. Pengukuran berasaskan daripada data tomografi terhadap posisi implant kemudian dinilai di antara kedudukan implan yang direncanakan dan yang direalisasikan dalam satah sagittal dan coronal. Analisa statistik dijalankan menggunakan Statistik Statistik PASW® 18. Hasil kajian menunjukkan bahawa 38 daripada 48 penanda permukaan yang dinilai menunjukkan peningkatan ketinggian kedudukan dalam skala kecil pasca-pembedahan berbanding dengan kedudukan implan orbital maya. Semakan metrik Euclidean menunjukkan perbezaan yang kurang daripada 1.00 mm dalam semua penanda permukaan kecuali pada kawasan lej posterior dan anterior dalam penilaian satah sagittal. Kajian ini menunjukkan bahawa penempatan penanda permukaan terhadap implant orbit dalam pembedahan navigasi orbit menyumbang kepada kedudukan implan orbital secara konsisten.
Artificial neural network (ANN) was used in this study to determine water turbidity by using back propagation algorithm. Three wavelengths which represent reflectance intensity for eight standard samples were used as training input. The finding from the study shows that the trained network with number of epochs of 250,000 and learning rate of 0.001 gave the lowest sum of squared error (SSE) of 0.04. ANN was able to predict the turbidity of water based on the pattern recognition of the reflectance spectrum. The architecture of optimized ANN used in this study was 3:25:1. The average prediction error was 0.02.
[Jaringan neural tiruan (ANN) dengan lagoritma perambatan balik (BP) telah digunakan dalam kajian ini untuk menentukan kekeruhan air. Tiga panjang gelombang yang mewakili serapan bagi lapan sampel telah dipilih sebagai imput latihan. Hasil kajian menunjukkan bagi jaringan terlatih dengan bilangan ulangan latihan 250,000 dan kadar pembelajaran 0.001 telah memberikan nilai SSE yang terendah iaitu 0.04. Dalam kajian ini jaringan ANN didapati boleh menentu dan meramalkan nilai kekeruhan sample air berdasarkan corak serapan pantulan. Arkitektur yang sesuai bagi kajian ini adalah 3:25:1. Purata ralat ramalan adalah 0.02].
The simultaneous measurement of the concentration of anticancer drugs with a fast, sensitive and accurate method in biological samples is a challenge for better monitoring of drug therapy and better determine the pharmacokinetics. An electrochemical sensor was developed for the simultaneous determination of anticancer drugs, Ifosfamide (IFO) and Etoposide (ETO) based on pencil graphite electrode modified with Au/Pd@rGO nanocomposite decorated with poly (L-Cysteine). Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were utilized to study the properties of the modified electrode. The electrochemical behavior of IFO and ETO on the Au/Pd@rGO@p(L-Cys) modified electrode was investigated by cyclic voltammetry and differential pulse voltammetry (DPV) techniques and the obtained results confirmed its efficiency for the individual and simultaneous sensing of IFO and ETO. After optimization of electrochemical parameters, the fabricated sensor presented excellent performance in simultaneous determination of IFO and ETO with a wide linear range from 0.10 to 90.0 μM and 0.01 to 40.0 μM and low detection limits (3 Sb/m) of 9.210 nM and 0.718 nM, respectively. In addition, this study proved that the constructed sensor could be useful to simultaneous analysis of IFO and ETO in biological samples and pharmaceutical compounds.
Etoposide (ETS), topoisomerase-II inhibitor, is a first-line anticancer therapeutics used in diverse cancer types. However, the therapeutic potential of this molecule has mainly impeded due to its detrimental toxicity profile, unfavorable rejection by the cancer cells due to P-glycoprotein (P-gp) efflux activity, and rapid hepatic clearance through extensive metabolism by Cytochrome-P450. To increase the therapeutic potency without significant adverse effects, the implication of novel ETS-nanoformulation strategies have recommended mainly. Nanomedicine based nanoformulation approaches based on nanoparticles (NPs), dendrimers, carbon-nanotubes (CNTs), liposomes, polymeric micelles, emulsions, dendrimers, solid-lipid NPs, etc offers immense potential opportunities to improve the therapeutic potential of pharmaceutically problematic drugs. This review provides an up-to-date argument on the work done in the field of nanomedicine to resolve pharmacokinetic and pharmacodynamic issues associated with ETS. The review also expounds the progress in regards to the regulatory, patenting and clinical trials related to the innovative formulation aspects of ETS.
Neuroendocrine carcinoma of the female
reproductive tract are a heterogeneous group of rare
neoplasms posing both diagnostic and therapeutic
challenges. The recent classification by WHO
includes neuroendocrine carcinomas (NECs) and
neuroendocrine tumours (NETs). NECs are the poorly
differentiated small cell carcinoma (SCNEC) and
large cell neuroendocrine carcinoma (LCNEC), while
well-differentiated NETs include typical carcinoids
(TC) and atypical carcinoids (AC). Majority of
these tumours have an aggressive clinical course and
published data is supportive of multi-modal therapeutic
strategies. Etoposide/platinum based chemotherapy is
commonly advocated. Histopathological categorisation
and diagnosis are paramount to guide therapy.
Well-differentiated carcinoid and atypical
carcinoid tumours should be managed similar to
gastroenteropancreatic neuroendocrine tumours.
This review discusses the current classification, clinicpathologic
characteristics and advances in the diagnostic
evaluation and the treatment options of neuroendocrine
carcinoma of the cervix.
Haemophagocytic lymphohistiocytosis (HLH) is an uncommon disease with a high fatality rate. Etoposide is an important component of current HLH treatment regimes. Two patients with HLH developed etoposide-related secondary acute myeloid leukemia (sAML) following therapy for HLH. Etoposide, an epipodophyllotoxin, is a topoisomerase II inhibitor that interacts with DNA to potentiate leukaemogenesis. The risk of developing sAML is estimated to be between 1% and 5%, 2-20 years after exposure to etoposide but may also be related to cumulative drug doses, treatment schedules, host factors and co-administration of other antineoplastic agents.
To study the clinical presentation, therapy and outcome of children diagnosed with both primary and secondary haemophagocytic lymphohistiocytosis (HLH) at the University of Malaya Medical Centre.
Haemophagocytic lymphohistiocytosis (HLH) is rare. Although Kawasaki disease (KD) has been reported as a precursor to HLH, coronary arteritis occurring at the onset of secondary HLH, not in association with KD, has not been reported. An 8-year-old girl presented with virus-induced secondary HLH associated with a giant aneurysm and ectasia of the coronary arteries which was detected incidentally at onset of the disease. She did not fulfill the criteria for diagnosis of KD. The coronary lesions improved after 6 months of treatment with dexamethasone and etoposide. Echocardiography early in the course of HLH is a useful tool to detect the unusual finding of coronary arteritis which may carry significant clinical sequelae.
Introduction: Secondary Hemophagocytic Lymphohistiocytosis (HLH) is a condition seen in severe dengue that can be potentially fatal. Timely management using HLH-directed treatment such as steroids or etoposide have been seen to improve the outcome of patients however there is no protocol on how to manage the disease. Two criteria commonly used to guide the direction of treatment are namely the HLH-2004 criteria and the Hscore; with the latter being used more often. The best cut-off H score is 169 corresponding to a sensitivity of 93%, specificity of 86% and accurate classification of 90% of the patients. We described of five patients diagnosed with severe dengue compli-cated with HLH. Methods: 5 cases that were diagnosed with severe dengue with secondary HLH and received dexa-methasone were reviewed retrospectively and clinical data extracted. Results: All patients had fever beyond critical or leaking phase. Four out of five cases had Hscore higher than 169 and had a mean score of 181 with only one bone marrow performed. Three patients had concurrent leaking and bleeding and three patients had fast progression of se-vere transaminitis during the critical phase. The mean peak ferritin level was 21077 micro/L. The only bone marrow aspiration done revealed increased macrophages and hemophagocytic activity. All patients received a short course of dexamethasone and discharged well. Conclusion: Short course dexamethasone is effective in treatment of HLH in dengue despite the concerns of administration of steroids in bleeding dengue patient. Secondary HLH in dengue remains a clinical diagnosis with no conclusive diagnostic criteria. It should be suspected in a severe dengue patient with hyperferritinemia and persistent fever. Technical difficulty of performing bone marrow during severe dengue makes conclusive diagnosis remains elusive.
A pure ovarian choriocarcinoma is a very rare disease which can be either pregnancy related (gestational), may not be related (non-gestational), or commonly correlated with different type of germ cell; teratocarcinoma, dysgerminoma or undifferentiated carcinoma. A pure non-gestational primary ovarian choriocarcinoma is astronomically uncommon and we recorded such condition in 14-year-old teenage girl’s ovary. An abdominal operative procedure with the help of a careful histopathology examination revealed choriocarcinoma in absence of other type of germ cell element. Multiple courses of Etoposide/Methotrexate/Actinomycin-D (EMA) regime of chemotherapy were shown to be effective in this case.
Extra-gonadal germ cell tumours (EGGCT) are rare. Therefore further investigations of the testis is aimed at sourcing a possible primary origin of gonadal tumour. Over the years, various case series on EGGCT have been reported questioning its true nature as in a majority of them, a primary source is found in the testis, thus representing a metastatic gonadal tumour. The testis pathology could be either a true germ cell foci, an intra-tubular epithelial neoplasia or an area of fibrosis, indicating a ‘burnt out tumour’. We report a 39-year-old male who underwent laparotomy and excision of a retroperitoneal tumour. Histopathological examination revealed retroperitoneal lymph node of mixed germ cell tumour origin. Clinical and ultrasound examination of bilateral testis was normal. The patient refused orchidectomy or a testicular biopsy. He underwent four cycles of bleomycin, cisplatin, and etoposide with no evidence of tumour recurrence on follow up and remains disease free after 12 months of diagnosis. A literature review of EGGCT, its relation and factors relating with future testicular tumour is presented.
INTRODUCTION: The use of e-cigarettes (EC) has reached alarming proportions among Malaysians. On a national level, little is known about the profile and perceptions of Malaysian EC users. This study aimed to explore the prevalence of long-term EC usage and its associated factors among EC users in Malaysia.
METHODS: This nationwide online questionnaire survey was administered among 694 EC users across 13 states and 1 Federal Territory in Malaysia, between January and April 2018. A survey link was e-mailed to EC users that were recruited from an official national vape entity through their Facebook association page. We obtained information on respondents' sociodemographic characteristics, smoking habits, long-term e-cigarette usage and perceptions of EC use. We estimated long-term EC user prevalence and fitted multivariate regression models to predict factors associated with long-term EC usage. Statistical significance was set at p<0.05.
RESULTS: Respondents were predominantly Malays (87.6%), aged >30 years (68.1%) and tertiary educated (71%). The majority were employed (93.1%) with a monthly household income of MYR 4000 or less (56.6%). About 84% were former smokers, while 10% were current smokers. The prevalence of long-term EC usage in this study was 82.3%. Most users believed that EC had helped them to cut down tobacco smoking (94.8%), reduced the urge to smoke (88.3%) and ultimately helped them to quit smoking (87.2%). Respondents aged >30 years and those who perceived that EC has helped them stop smoking were significantly more likely to be long-term EC users.
CONCLUSIONS: Most respondents engaged in EC use to quit smoking. They were more likely to be long-term EC users if they were older and perceived that EC has helped them to quit smoking. This information is valuable for targeted prevention, health promotion and policy regulations.
In the last decade, chemotherapy in combination with focal therapy (chemoreduction) has been increasingly used in intraocular retinoblastoma to avoid enucleation and radiotherapy. The aim of this study was to assess the feasibility and outcome of chemoreduction in Malaysian children with retinoblastoma. This was a prospective study from August 2001 to January 2006. Twenty children (25 eyes) were given 4 cycles of chemoreduction, after which the response was assessed. Fourteen eyes showed a complete response, 10 eyes showed a partial response, and 1 eye had progressive disease. Twelve eyes developed progressive disease later, 9 after an initial complete response and 3 after a partial response. Overall, progressive disease occurred in 52%. There were 2 treatment failures, in Reese-Elsworth groups 3 and 4. Both eyes required enucleation. One eye in group 5 required second line chemotherapy to achieve a complete response. No eyes were irradiated. Five children (25%) defaulted follow-up, one of whom returned with disseminated disease. In conclusion, 4 cycles of chemoreduction achieved a durable complete response in only 12% of eyes. Chemoreduction is feasible in Malaysia but requires good patient compliance and close follow-up.
We report five patients who presented with seminoma of an undescended testis to highlight the importance of dealing with adult cryptorchidism. On the basis of the literature review and our experience, we advocate orchidectomy for post-pubertal cryptorchid patients of any age because follow-up may be difficult, and treatment for the tumour may be unsuccessful.
Treatment for childhood acute myeloid leukaemia (AML) consists of remission induction chemotherapy followed by postremission chemotherapy with or without bone marrow transplantation. The AML Berlin-Frankfurt-Munster (BFM)-83 protocol with induction-consolidation-maintenance chemotherapy for 2 years has been reported to result in a 6-year event-free survival (EFS) and event-free interval (EFI) of 49% and 61% respectively. A total of 174 Malaysian children were treated with this protocol between 1985 and 1999. The 5-year EFS and EFI was 30.7% and 48.0% respectively. The overall mortality from sepsis was 24%, which needs urgent address. The 5-year EFS for patients treated before 1993 and after 1993 was 18.6% and 41.3%, respectively (P = 0.04), while the EFI was 32% and 60.6% respectively (P = 0.034). The improvement seen after 1993 was related to a reduction in induction deaths for that period and probably reflected increased capability and familiarity to cope with the demands of the AML-BFM-83 protocol and accompanying complications in the treatment of AML.
Acute myeloid leukemia (AML) is one of the most frequent types of leukemia which mostly affects adult people. Resistance to therapeutic drugs is considered as a major clinical concern resulting in a weaker response to chemotherapy, disease relapse and decreased survival rate. Survivin, a member of Inhibitor of Apoptosis Proteins (IAPs), is associated with drug resistance and inhibition of apoptotic mechanisms in numerous hematological malignancies. In the present study, we examined the combined effect of etoposide and siRNA-mediated silencing of survivin on U-937 acute myeloid leukemia cells. The AML cells were transfected with survivin specific siRNA and gene knockdown was confirmed by quantitative real time PCR and western blotting. Subsequently, U-937 cells were assessed for response to etoposide treatment and apoptosis rate was measured with flowcytometery. The cytotoxic effects in siRNA-etoposide group were measured and compared to etoposide single therapy group. Survivin siRNA effectively knocked down the mRNA and protein levels of survivin, which led to lower cell proliferation and enhanced apoptosis. Furthermore, combined treatment of etoposide and survivin siRNA synergistically increased the cell toxic effects of etoposide and its ability to induce apoptosis.