In this study, a novel multiphasic model for the calculation of the polypropylene production in a complicated hydrodynamic and the physiochemical environments has been formulated, confirmed and validated. This is a first research attempt that describes the development of the dual-phasic phenomena, the impact of the optimal process conditions on the production rate of polypropylene and the fluidized bed dynamic details which could be concurrently obtained after solving the model coupled with the CFD (computational fluid dynamics) model, the basic mathematical model and the moment equations. Furthermore, we have established the quantitative relationship between the operational condition and the dynamic gas⁻solid behavior in actual reaction environments. Our results state that the proposed model could be applied for generalizing the production rate of the polymer from a chemical procedure to pilot-scale chemical reaction engineering. However, it was assumed that the solids present in the bubble phase and the reactant gas present in the emulsion phase improved the multiphasic model, thus taking into account that the polymerization took place mutually in the emulsion besides the bubble phase. It was observed that with respect to the experimental extent of the superficial gas velocity and the Ziegler-Natta feed rate, the ratio of the polymer produced as compared to the overall rate of production was approximately in the range of 9%⁻11%. This is a significant amount and it should not be ignored. We also carried out the simulation studies for comparing the data of the CFD-dependent dual-phasic model, the emulsion phase model, the dynamic bubble model and the experimental results. It was noted that the improved dual-phasic model and the CFD model were able to predict more constricted and safer windows at similar conditions as compared to the experimental results. Our work is unique, as the integrated developed model is able to offer clearer ideas related to the dynamic bed parameters for the separate phases and is also capable of computing the chemical reaction rate for every phase in the reaction. Our improved mutiphasic model revealed similar dynamic behaviour as the conventional model in the initial stages of the polymerization reaction; however, it diverged as time progressed.
The properties of a composite material depend on its constituent materials such as natural biopolymers or synthetic biodegradable polymers and inorganic or organic nanomaterials or nano-scale minerals. The significance of bio-based and synthetic polymers and their drawbacks on coating film application is currently being discussed in research papers and articles. Properties and applications vary for each novel synthetic bio-based material, and a number of such materials have been fabricated in recent years. This review provides an in-depth discussion on the properties and applications of biopolymer-based nanocomposite coating films. Recent works and articles are cited in this paper. These citations are ubiquitous in the development of novel bionanocomposites and their applications.
This study investigates the flexural behaviour of reinforced concrete (RC) beams strengthened through the combined externally bonded and near-surface mounted (CEBNSM) technique. The externally bonded reinforcement (EBR) and near-surface mounted (NSM) techniques are popular strengthening solutions, although these methods often demonstrate premature debonding failure. The proposed CEBNSM technique increases the bond area of the concrete⁻carbon fibre reinforced polymer (CFRP) interface, which can delay the debonding failure. This technique is appropriate when any structure has a narrow cross-sectional width or is in need of additional flexural capacity that an individual technique or material cannot attain. An experimental test matrix was designed with one control and five strengthened RC beams to verify the performance of the proposed technique. The strengthening materials were CFRP bar as NSM reinforcement combined with CFRP fabric as EBR material. The test variables were the diameter of the NSM bars (8 and 10 mm), the thickness of the CFRP fabrics (one and two layers) and the U-wrap anchorage. The strengthened beams showed enhancement of ultimate load capacity, stiffness, cracking behaviour, and strain compatibility. The ultimate capacity of the CEBNSM-strengthened beams increased from 71% to 105% compared to that of the control beam. A simulation method based on the moment-rotation approach was also presented to predict the behaviour of CEBNSM-strengthened RC beams.
The effect of TiO₂ nanoparticle (NP) content on the improvement of poly(9,9'-di-n-octylfluorenyl-2,7-diyl) (PFO)/Fluorol 7GA organic light emitting diode (OLED) performance is demonstrated here. The PFO/Fluorol 7GA blend with specific ratios of TiO₂ NPs was prepared via a solution blending method before being spin-coated onto an indium tin oxide (ITO) substrate to act as an emissive layer in OLEDs. A thin aluminum layer as top electrode was deposited onto the emissive layer using the electron beam chamber. Improvement electron injection from the cathode was achieved upon incorporation of TiO₂ NPs into the PFO/Fluorol 7GA blend, thus producing devices with intense luminance and lower turn-on voltage. The ITO/(PFO/Fluorol 7GA/TiO₂)/Al OLED device exhibited maximum electroluminescence intensity and luminance at 25 wt % of TiO₂ NPs, while maximum luminance efficiency was achieved with 15 wt % TiO₂ NP content. In addition, this work proved that the performance of the devices was strongly affected by the surface morphology, which in turn depended on the TiO₂ NP content.
MeSH terms: Aluminum; Electrodes; Electrons; Isoquinolines; Tin Compounds; Nanoparticles
This paper focuses on the synthesis and mechanism of carbon nanospheres (CNS) coated with few- and multi-layered graphene (FLG, MLG). The graphitic carbon encapsulates the core/shell structure of the Ni/NiO nanoparticles via the chemical vapor deposition (CVD) method. The application of the resulting CNS and hybrids of CNS-FLG and CNS-MLG as reinforcement nanofillers in a polypropylene (PP) matrix were studied from the aspects of mechanical and thermal characteristics. In this research, to synthesize carbon nanostructures, nickel nitrate hexahydrate (Ni(NO₃)₂·6H₂O) and acetylene (C₂H₂) were used as the catalyst source and carbon source, respectively. Besides, the morphology, structure and graphitization of the resulting carbon nanostructures were investigated. On the other hand, the mechanisms of CNS growth and the synthesis of graphene sheets on the CNS surface were studied. Finally, the mechanical and thermal properties of the CNS/PP, CNS-FLG/PP, and CNS-MLG/PP composites were analyzed by applying tensile test and thermogravimetric analysis (TGA), respectively.
Pectin is an anionic, water-soluble polymer predominantly consisting of covalently 1,4-linked α-d-galacturonic acid units. This naturally occurring, renewable and biodegradable polymer is underutilized in polymer science due to its insolubility in organic solvents, which renders conventional polymerization methods impractical. To circumvent this problem, cerium-initiated radical polymerization was utilized to graft methoxy-poly(ethylene glycol) methacrylate (mPEGMA) onto pectin in water. The copolymers were characterized by ¹H nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA), and used in the formation of supramolecular hydrogels through the addition of α-cyclodextrin (α-CD) to induce crosslinking. These hydrogels possessed thixotropic properties; shear-thinning to liquid upon agitation but settling into gels at rest. In contrast to most of the other hydrogels produced through the use of poly(ethylene glycol) (PEG)-grafted polymers, the pectin-PEGMA/α-CD hydrogels were unaffected by temperature changes.
Cardiovascular disease is the leading cause of death in adult international travellers. Patients living with heart disease should receive specific, individualised pre-travel health advice. The purpose of this article is to provide evidence-based advice to physicians who are consulted by travellers with cardiovascular disease. Fitness-to-travel evaluation will often be conducted by the general practitioner but other medical specialists may also be consulted for advice. Patients with chronic medical conditions should purchase travel health insurance. The general pre-travel health consultation addresses food and water safety, insect and animal bite avoidance, malaria chemoprophylaxis, and travel vaccinations. Patients with devices such as cardiac pacemakers should be familiar with how these may be affected by travel. Cardiac medications may cause adverse effects in cold or hot environments, and specific precautions must be followed by anticoagulated travellers. The physician should be aware of how to access medical care abroad, and of the potential for imported tropical diseases in returned travellers.
Diarrheal diseases (DD) are leading causes of disease burden, death, and disability, especially in children in low-income settings. DD can also impact a child's potential livelihood through stunted physical growth, cognitive impairment, and other sequelae. As part of the Global Burden of Disease Study, we estimated DD burden, and the burden attributable to specific risk factors and particular etiologies, in the Eastern Mediterranean Region (EMR) between 1990 and 2013. For both sexes and all ages, we calculated disability-adjusted life years (DALYs), which are the sum of years of life lost and years lived with disability. We estimate that over 125,000 deaths (3.6% of total deaths) were due to DD in the EMR in 2013, with a greater burden of DD in low- and middle-income countries. Diarrhea deaths per 100,000 children under 5 years of age ranged from one (95% uncertainty interval [UI] = 0-1) in Bahrain and Oman to 471 (95% UI = 245-763) in Somalia. The pattern for diarrhea DALYs among those under 5 years of age closely followed that for diarrheal deaths. DALYs per 100,000 ranged from 739 (95% UI = 520-989) in Syria to 40,869 (95% UI = 21,540-65,823) in Somalia. Our results highlighted a highly inequitable burden of DD in EMR, mainly driven by the lack of access to proper resources such as water and sanitation. Our findings will guide preventive and treatment interventions which are based on evidence and which follow the ultimate goal of reducing the DD burden.
MeSH terms: Child; Child, Preschool; Diarrhea/economics; Diarrhea/mortality*; Diarrhea/epidemiology*; Female; Disabled Persons; Humans; Male; Risk Factors; Cost of Illness; Quality-Adjusted Life Years; Mediterranean Region/epidemiology; Global Burden of Disease*
Eighty-seven percent of cervix cancer occurs in less-developed regions of the world, and there is up to an 18-fold difference in mortality rate for cervix cancer depending on the region of the world. The Cervix Cancer Research Network (CCRN) was founded through the Gynecologic Cancer InterGroup with the aim of improving access to clinical trials in cervix cancer worldwide, and in so doing improving standards of care. The CCRN recently held its first international educational symposium in Bangkok. Sixty-two participants attended from 16 different countries including Pakistan, India, Bangladesh, Thailand, Malaysia, Singapore, Philippines, Taiwan, China, Vietnam, Korea, Japan, Columbia, Brazil, Canada, and the United States. The focus of this symposium was to evaluate progress, to promote new clinical trials for the CCRN, and to provide education regarding the role of brachytherapy in the treatment of cervical cancer.
MeSH terms: Bangladesh; Brachytherapy; Brazil; Canada; Uterine Cervical Neoplasms; China; Female; Genital Neoplasms, Female; Humans; India; Japan; Malaysia; Pakistan; Philippines; Singapore; Taiwan; Thailand; United States; Vietnam; Republic of Korea; Standard of Care
As Electronic Medical Records (EMRs) have a great possibility for rising physician's performance in their daily work which improves quality, safety and efficiency in healthcare, they are implemented throughout the world (Boonstra and Broekhuis, 2010). In physician practices the rate of EMRs adoption has been slow and restricted (around 25%) according to Endsley, Baker, Kershner, and Curtin (2005) in spite of the cost savings through lower administrative costs and medical errors related with EMRs systems. The core objective of this research is to identify, categorize, and analyse meso-level factors introduced by Lau et al, 2012, perceived by physicians to the adoption of EMRs in order to give more knowledge in primary care setting. Finding was extracted through questionnaire which distributed to 350 physicians in primary cares in Malaysia to assess their perception towards EMRs adoption. The findings showed that Physicians had positive perception towards some features related to technology adoption success and emphasized EMRs had helpful impact in their office. The fuzzy TOPSIS physician EMRs adoption model in meso-level developed and its factors and sub-factors discussed in this study which provide making sense of EMRs adoption. The related factors based on meso-level perspective prioritized and ranked by using the fuzzy TOPSIS. The purpose of ranking using these approaches is to inspect which factors are more imperative in EMRs adoption among primary care physicians. The result of performing fuzzy TOPSIS is as a novelty method to identify the critical factors which assist healthcare organizations to inspire their users in accepting of new technology.
MeSH terms: Delivery of Health Care; Group Practice; Malaysia; Primary Health Care; Surveys and Questionnaires; Cost Savings; Medical Errors; Electronic Health Records; Physicians, Primary Care
Multiple anomalies in the celiac arterial system presents as rare vascular malformations, depicting deviations of the normal vascular developmental pattern. We found a common left gastro-phrenic trunk and a hepato-spleno-mesenteric trunk arising separately from the abdominal aorta in one cadaver. We also found a common hepatic artery and a gastro-splenic trunk arising individually from the abdominal aorta in another cadaver. Even though many variations in the celiac trunk have been described earlier, the complex variations described here are not mentioned and classified by earlier literature. Knowledge of such variations has significance in the surgical and invasive arterial radiological procedures in the upper abdomen.
A 28-year-old male patient with bipolar disorder taking olanzapine and lorazepam for almost 10 years presented with weight gain, diabetes, and anasarca was examined in this study. Evaluation of the patient revealed he was in heart failure. The reason for his heart failure was ambiguous and an investigation into it revealed negative results. Literature search conducted showed a few reported cases of putative olanzapine induced cardiomyopathy. One such relatively rare case is presented here.
Castleman disease (CD) is a rare lymphoproliferative disorder of unknown aetiology. It manifests in two distinct clinical presentations: unicentric and multicentric. Unicentric CD is rare and may present as an isolated neck mass. A 22-year-old man presented with a 6-month history of right neck swelling that occupied the posterior triangle of the right neck region. After surgical exploration, a solitary, well defined, and hyper vascular mass was excise. A histopathological examination confirmed the lesion as CD, hyaline-vascular variant. CD of the neck is a diagnosis that is usually not taken into consideration while evaluating neck masses due to its rarity and unassuming presentation. It should be keep in the differential diagnosis of neck masses as the clinical and radiological features evade a firm diagnosis. The treatment of unicentric CD is complete surgical excision, which cures the patient.
Repeated experimental reinfection of two subjects indicates that Helicobacter pylori infection does not promote an immune response protective against future reinfection. Our results highlight the importance of preventing reinfection after eradication, through public health initiatives, and possibly treatment of family members. They indicate difficulties for vaccine development, especially therapeutic vaccines.
MeSH terms: Family; Public Health; Vaccines; Helicobacter pylori; Helicobacter Infections; Biomedical Research
BACKGROUND: Dengue virus infection is on the rise and there is increasing number of ocular complications that are being reported. Most common ocular complications are macular edema, macular hemorrhages, and foveolitis. There are case reports on branch retinal vessel occlusions. Most of the ocular complications are attributed to the bleeding tendency and transudative process in dengue viral infection. This is a case report of ischemic central retinal vein occlusion (CRVO) concomitant with dengue fever.
CASE PRESENTATION: A 41 year old Malay female was admitted to medical ward and diagnosed to have "dengue fever with warning signs". On the day of admission she noted sudden onset of right eye blurring of vision. She presented to our clinic 1 week later. Ocular examination revealed right eye visual acuity of <20/1000 and ischaemic CRVO with macular edema. She had no other risk factors to develop retinal vein occlusion. She progressively developed proliferative retinopathy and received multiple laser therapy. There was no anterior segment neovascularization. However, her vision improved to only 20/400 despite of resolution of macular edema and new vessels elsewhere.
CONCLUSION: Dengue virus infection is known to cause thrombocytopenia which can result in hemorrhagic events. It can also cause procoagulant state which can result in thrombotic events secondary to immune reaction. Awareness among treating physicians of such ocular complication which can result in significant morbidity for patient is necessary.
Pleural effusion or hydrothorax is a relatively rare but well-recognized complication associated with peritoneal dialysis (PD). We describe the successful long term resolution of a patient who developed pleural effusions after starting continuous ambulatory peritoneal dialysis (CAPD), by altering the PD prescription to normal volume daytime ambulatory peritoneal dialysis (DAPD) transiently before resuming the usual CAPD exchanges four months later. After 8 years of follow up, there is no sign of recurrence of the effusion. Normal volume DAPD present as an attractive alternative and cheap method for resolution of pleura-peritoneal fistula.
Foreign body (FB) ingestion is very common in Malaysian population. The most commonly ingested FB is fish bone. Common presenting symptoms include FB sensation, odynophagia and or sharp pricking pain during swallowing. A careful history and physical examination is very important. Despite negative laryngoscopy and rigid esophagoscopy, persistent symptoms warrants further radiographic imaging studies. The FB can migrate extraluminally and involve other important adjacent structures of the neck and along the digestive tract. We report 3 cases of extraluminal migration of fish bone and their complications, which were successfully managed. One case with vascular complication which involve common carotid artery and the other two cases with neck abscess formation involving thyroid gland, retropharyngeal and parapharyngeal abscess.
Multiple sclerosis (MS) patients treated with natalizumab often face the uncommon but severe complication of developing progressive multifocal leukoencephalopathy (PML). PML may be further complicated by immune reconstitution inflammatory syndrome (IRIS) after the removal of the drug. Since both PML and IRIS are associated with high morbidity and mortality rates, early clinical and radiological diagnosis of these complications is of paramount importance. Here, we report a case of an adult male patient who was diagnosed with PML after receiving natalizumab therapy for 6 years for the treatment of MS. Upon cessation of natalizumab, he presented with a paradoxical worsening of clinical and radiological findings consistent with an inflammatory brain injury due to IRIS. He was treated with high dose corticosteroid therapy followed by a gradual improvement in clinical and imaging findings. This article illustrates the magnetic resonance imaging (MRI) features of natalizumab-associated PML-IRIS, along with a brief overview of its clinical features, complications and management strategies.
Term, live abdominal pregnancy secondary to rupture of a uterine rudimentary horn is a rare condition. Pregnancies conceived in the rudimentary horn of the uterus usually rupture during early gestation and present as a catastrophic event. However, rarely, after rupture of the uterine horn the foetus may continue to grow in the abdominal cavity and reach term gestation. A primigravida with a term pregnancy was referred to our centre for caesarean section with ultrasonography findings of transverse lie and placenta previa. During surgery, a live baby was extracted from the abdominal cavity, revealing a bicornuate uterus with rupture of the rudimentary horn. The early peroperative diagnosis and prompt control of the bleeding with excision of the rudimentary horn and transfusion of multiple blood products saved the patient's life. The case is presented for its rarity and to highlight the importance of a high index of suspicion in cases presenting with abnormal foetal presentation.