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COVID-19 is a global public health problem that causes severe acute respiratory syndrome (SARS). It is also extremely contagious with rapidly increasing death rates. In this paper, we propose an optimal control model with SIRS (Susceptible–Infected–Recovered- Susceptible) kinetics to examine the effects of several intervention measures (e.g., vaccination and treatment) under the limited medical resources scenarios. This model is also employed to investigate the possibility of reinfection because of the fading of immunity problem. As a case study, the modeling framework is parametrised using COVID-19 daily confirmed and recovered cases in Malaysia. The parameters have been approximated by relying on the model's best fit to actual data published by the Malaysian Ministry of Health (MOH). Our numerical simulation results show that the inclusion of optimal control components with vaccination and treatment strategies would dramatically reduce the number of active cases even in the presence of reinfection forces. Regardless of the relative weightage (or costs) of vaccination and treatment, as well as the possibility of reinfection, it is critical to plan effective COVID-19 control measures by vaccinating as many people as possible (and as early as possible). Overall, these insights help explore the importance of intervention measures and the allocation of medical resources to control the severity of this pandemic.

In this research, palm oil and soy oil were used as a natural polyol to prepare novel poly(silyl ether)s. Palm oil and soy oil were first converted to monoglyceride by one step via alcoholysis process in the presence of 0.1% CaO as a catalyst. The monoglycerides were characterized by Fourier transform infrared spectrometer (FT-IR), nuclear magnetic resonance (NMR) and iodine test. The novel poly(silyl ether)s were prepared via polycondensation reaction between dimethyldichlorosilane with monoglycerides based on palm and soy oils, respectively. FT-IR, NMR and silicone-29 (29Si NMR) were used to confirm and determine the presence of silicone in the synthesized polymers. Thermal behavior was studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Antibacterial activity of the polymers was screened against three different strains of bacteria, namely Escherichia coli E266, Staphylococcus aureus S276 and Salmonella choleeraesuis 10708.

COVID-19 is a major health threat across the globe, which causes severe acute respiratory syndrome (SARS), and it is highly contagious with significant mortality. In this study, we conduct a scenario analysis for COVID-19 in Malaysia using a simple universality class of the SIR system and extensions thereof (i.e., the inclusion of temporary immunity through the reinfection problems and limited medical resources scenarios leads to the SIRS-type model). This system has been employed in order to provide further insights on the long-term outcomes of COVID-19 pandemic. As a case study, the COVID-19 transmission dynamics are investigated using daily confirmed cases in Malaysia, where some of the epidemiological parameters of this system are estimated based on the fitting of the model to real COVID-19 data released by the Ministry of Health Malaysia (MOH). We observe that this model is able to mimic the trend of infection trajectories of COVID-19 pandemic in Malaysia and it is possible for transmission dynamics to be influenced by the reinfection force and limited medical resources problems. A rebound effect in transmission could occur after several years and this situation depends on the intensity of reinfection force. Our analysis also depicts the existence of a critical value in reinfection threshold beyond which the infection dynamics persist and the COVID-19 outbreaks are rather hard to eradicate. Therefore, understanding the interplay between distinct epidemiological factors using mathematical modelling approaches could help to support authorities in making informed decisions so as to control the spread of this pandemic effectively.

Background: In the present study, the formation of 2, 4, 4-trimethyl-7,2’4’-trihydroxy flavan has been used as the key feature for the formation of new 1,3-benzoxazines. This reaction was carried out via Mannich-condensation reaction, the 7-hydroxy group of flavan was reacted with different primary amines in the presence of formaldehyde. Methods: All the synthesized compounds were characterized on the basis of FT-IR, NMR, MS and elemental analysis (CHN). Disk diffusion and 96-well plate assay methods were employed for the zone of inhibition and minimum inhibitory concentration determination, respectively to investigate the antibacterial activities. Results and Conclusion: Our studies showed that compound with electron withdrawing group on the benzene ring of 1,3-benzoxazines has promising antibacterial activities. An oral dose of 10 mg/kg body weight was administered to albino mice for acute toxicity of synthesized compounds. In vivo anti-inflammatory and in-vitro cyclooxygenase-2 (COX-2) studies showed that compound 11 was the most potent anti-inflammatory agent which inhibited induced edema by 62.7% while 68.7% inhibition of COX-2 was observed. The plausible binding mode of this compound in COX-2 enzyme was also determined using molecular docking simulations.

Upper tract urothelial carcinoma represents a small proportion (5%–10%) of all urothelial cancers. Although there are several management options, in undifferentiated or high-risk cases, surgery in the form of nephroureterectomy is the gold standard. Horseshoe kidney is the most common congenital renal fusion anomaly affecting 1 in 400–600 patients. We present the case of a smoker in her mid-50s with an incidental finding of a papillary lesion in the right renal pelvis of her horseshoe kidney on CT scan. She went on to have endoscopic assessment confirming no other foci of disease. She was definitively managed with a robotic nephroureterectomy.

Background Currently there is limited research documenting the changes in blood parameters, following Flexible Ureterorenoscopy. This study aims to determine whether there are any changes in haematology and biochemistry parameters, following Flexible Ureterorenoscopy for the treatment of kidney stones. Methods 40 consecutive patients aged between 27-87 years (median 49 years) undergoing Flexible Ureterorenoscopy for the treatment of kidney stones were recruited (26 male, 14 female). Blood samples were collected from each patient at four time points: baseline (pre-operatively) followed by 30 minutes, 120 minutes and 240 minutes post-operatively. On these samples, routine haematological and biochemistry tests were carried out. In addition to the assessment of clinical parameters prospectively from the medical notes. Results There was a significant decrease observed following Flexible Ureterorenoscopy in the following parameters: lymphocytes (p = 0.007), eosinophils (p = 0.001), basophils (p = 0.001), haemoglobin (p = 0.002), red blood cells (p = 0.001), platelet count (p = 0.001), fibrinogen concentration (p = 0.001), von Willebrand factor (p = 0.046), C reactive protein (p = 0.01), total protein (p = 0.001), albumin (p = 0.001), globulin (p = 0.001) and alkaline phosphatase (p = 0.001). In addition, there was a significant increase observed in the following parameters: white blood cells (p = 0.001), neutrophils (p = 0.001), activated partial thromboplastin time (p = 0.001), total bilirubin (p = 0.012), creatinine (p = 0.008), sodium (p = 0.002) and potassium (p = 0.001). Limiting factors for this study were the sample size, and restriction on the recruitment time points. Conclusions Significant changes were noted to occur in haematology and biochemistry parameters following Flexible Ureterorenoscopy. Some of the data presented in this study may represent the 'normal' post-operative response following FURS, as no major complications occurred, in the majority of our patients. This data on the 'normal response' will need to be validated but may ultimately aid clinicians in distinguishing patients at risk of complications, if reproduced in larger multi-centre studies.

Agatis wood (Agathis lorantifolia Salisb.) was impregnated with a combination of styrene and methyl methacrylate and compressed to a strain of 50% to improve dimensional stability and termite resistance. The changes in cell structure were analyzed to determine the effects of the combination treatment. The results showed that densification of agatis wood with compression, impregnation, and a combination of treatments resulted in an increase in physical properties (density and dimensional stability) by changing the cellular structure and chemical components (i.e., cellulose crystallinity, microfibril angle, and preferred orientation of fibers) as well as degradation of cellulose. The chemical modification and combination treatment (chemical and compression) of wood generally led to a high resistance to dry wood termites.

Triglycerides of palm (Elaeis guineensis) oil, soy (Glycine max) oil and sunflower (Helianthus annuus) oil were converted to monoglycerides by glycerolysis process. The monoglycerides derived from the different oils were reacted with phthalic anhydride at 2:1 monoglyceride-to-phthalic anhydride ratio to obtain novel polyols called alkyd diols. The polyols were reacted with 4,4′-methylenediphenyldiisocyanate (MDI) to produce five novel poly(alkyd-urethane)s (PAU), namely palm oil based poly(alkyd-urethane) (POPAU), soy oil based poly(alkyd-urethane) (SOPAU), sunflower oil based poly(alkyd-urethane) (SFPAU), palm-soy oils based poly(alkyd-urethane) (POSOPAU) and palm-sunflower oils based poly(alkyd-urethane) (POSFPAU). The successful synthesis of the monoglycerides, alkyd diols and poly(alkyd-urethane)s were confirmed by FTIR, 1H NMR, 13C NMR spectroscopy and their morphology were evaluated by scanning electron microscopy (SEM). Further analyses included viscosity, solubility, iodine number testing, gel content, drying time test, thermogravimetric analysis (TGA), crosshatch adhesion tests, impact strength, pencil hardness, chemical and water resistance. Palm oil poly(alkyd-urethane) showed good thermal stability with only 5% weight loss temperature in nitrogen at 270 °C. Improvements in coating performance after blending with sunflower oil or soy oil based alkyd-diols were also observed.

Treatment of the abundant oil palm empty fruit bunches with alkaline peroxide chemicals and subsequent fibrillation at varying mechanical energies resulted in favourable morphological changes of the generated fibers. The produced fibrous mass composed of intensely fibrillated elements ranging from micro to nanodiameter fibrils. nanofibrils and webs of nanofibrils were factors contributing to the functionality of the fibrous mass as fibre web augmentation elements. Profound improvement in fiber network is particularly attributable to the ability of the collected elements to fill up inter-fiber gaps and this was attributable to the micro elements in the form of micro fines, segmented micro-fibrils and webs of nanofibrils. The uniquely generated thin layers of nanofibril webs (TN-webs), were found to increase fiber web density by gluing multiple layers of fibers, together. Having landed on the surface of micro-fiber web, these TN-webs were identified as responsible for the masking effects of the underlying micro-fibres. Under such condition, fibers were observed to coalesce, suggesting also an augmented fiber network as evident from the 130% increase in tensile index and a 450% enhancement in burst index of the resultant fiber web relative to those formed with the basic alkaline peroxide chemical-mechanical refining (CMR) synergy. This reveals a great promise to EFB for application as super-strong fibre-web materials such as packaging and specialty paper-based products.

The increasing popularity of the oil palm empty fruit bunches (EFB) as a source of non-wood fibre has prompted a variety of research on processing and utilisation of the material. In an attempt to define the characters, reusability and end-of-life, oil palm EFB was processed by the alkaline peroxide variable treatment (APVT) systems. Low synergy between alkaline peroxide (AP) chemical and mechanical fibrillation through fibrillation (CMR synergy) revealed the yield of segments of EFB vascular bundles while heightening the mechanical forces further, generated more uniform but a mixture of fiber and segments of fibre bundles. An intermediate CMR synergy generated fibres forming a more well-defined but a rough resultant fibre network due to partial fibrillation of the vascular bundle. Applying maximal CMR synergy was found to generate higher yield of network strengthening fibrous cells. These were later identified as nanoscale fiber network or nanoscan, consisting of 10-80 nm diameter fibers arranging themselves in a systematic network. Analysis of the polarity of fibers harvested from the APVT systems manifests the systematic construction of nanofibrils winding in helical manner to form arrays of nanofibres that glue themselves together as micro-fibrils. Interconnections between fibers and other gluing elements led to the vascular bundle known as the EFB biomass that was once dross and that can now be marvelled as an alternative source of nanofibers for the nanoindustry sector.

A new class of liquid crystalline epoxy resins has been developed by reacting the diglycidyl ether of bisphenol A (DGEBA) with two new mesogenic diols, 3,3′-dimethoxy-4,4′-di(hydroxyhexoxy)-N-benzylidene-o-tolidine and 4,4′-di(6-hydroxyhexoxy)-N-benzylidene-o-tolidine, containing azomethine groups. Fourier transformed infra-red (FT-IR), nuclear magnetic resonance (NMR) spectroscopy and CHN elemental analysis were used to confirm the chemical structures of these azomethine mesogenic diols. Cure reaction between DGEBA and the mesogenic diols were carried out with different ratios 1:1, 1:2 and 2:1. The mesogenic phase transitions for azomethine mesogenic diols and cured polymers were examined by differential scanning calorimetry (DSC) and polarized optical microscopy (POM). Thermal, mechanical and adhesion properties were then investigated for the cured polymers based on new azomethine mesogenic diols. The cured polymers were found to exhibit high thermal stability, flexibility and good adhesion properties compared to conventional resins.

Maleic anhydride was reacted with p -aminophenol and p -toluidine in the presence of di-phosphorus pentoxide (P 2 O 5 ) as a catalyst to produce two compounds: N -(4-hydroxy-phenyl)maleimide ( I ) and N -(4-methylphenyl)maleimide ( II ). The new azo compounds I(a-c) and II(a-c) were prepared by the reaction of I and II with three different aromatic amines, namely aniline, p -aminophenol and p -toluidine. The structures of these compounds were confirmed by CHN, FT-IR, 1 H-NMR, 13 C-NMR, mass spectrum and UV/Vis spectroscopy. Keywords: synthesis; azo compounds; aromatic amines; N-(4-hydroxylpheneyl)maleimide 1. Introduction Small molecules and macromolecules containing imide groups exhibit great electrical properties, good solubility in polar media, resistance to hydrolysis and high thermal stability [1-8]. Due to their excellent properties many efforts have been made to produce different compounds containing imide groups consisting of two carbonyl groups bound to nitrogen. The most common unsubstituted cyclic imides were prepared by heating dicarboxylic acids or their anhydrides with reactants including ammonia, urea, formamide lithium nitride or primary amines [9-12], but the reaction needs to be carried out at high temperatures for efficient ring closure. Recently, attempts at preparing imide compounds either by the

Two new mesogenic monomers, namely 3,3’-dimethoxy-4,4’-di(hydroxyhexoxy)-N-benzylidene-o-Tolidine (Ia) and 4,4’-di(6-hydroxyhexoxy)-N-benzylidene-o-Tolidine (IIa), were reacted with cadmium sulfide (CdS) via an in situ chemical precipitation method in ethanol to produce CdS nanocomposites. A series of different mass compositions of CdS with Ia and IIa ranging from 0.1:1.0 to 1.0:1.0 (w/w) were prepared and characterized using X-ray Diffraction (XRD), Raman spectroscopy, Fourier Transform Infrared Spectroscopy (FT-IR), Transmission Electron Microscopy (TEM), Polarizing Optical Microscopy (POM) and Differential Scanning Calorimetry (DSC), X-ray Photoelectron Spectroscopy (XPS) and Photoluminescence Spectroscopy (PL). XRD showed that the broad peaks are ascribed to the formation of cubic CdS nanoparticles in both Ia and IIa. The average particle size for both nanocomposites was less than 5 nm with a narrower size distribution when compared with pure CdS nanoparticles. The analyses from POM and DSC demonstrated that mass composition from 0.1:1.0 up to 0.5:1.0 of CdS:Ia nanocomposites showed their enantiotropic nematic phase. On the other hand, polarizing optical microscopy (POM) for IIa nanocomposites showed that the liquid crystal property vanished completely when the mass composition was at 0.2:1.0. PL emissions for CdS: Ia or IIa nanocomposites indicated deep trap defects occurred in these both samples. The PL results revealed that addition of CdS to Ia monomers suppressed the photoluminescence intensity of Ia. However, the introduction of CdS to IIa monomers increased the photoluminescence and was at a maximum when the mass composition was 0.3:1.0, then decreased in intensity as more CdS was added. The XPS results also showed that the stoichiometric ratios of S/Cd were close to 1.0:1.0 for both types of nanocomposites for a mass composition of 1.0:1.0 (CdS:matrix).

Network Function Virtualization (NFV) and Software Defined network (SDN) intend to deliver Next Generation Networks (NGN) related services over an intelligent, cost effective and cloudified infrastructure. This paper discusses a new NGN design based on cloud services such as NFV and SDN in order to improve network scalability, elasticity, usage efficiency and resiliency while decreasing cost. In this paper, we discuss the detailed architectural design along with the functionality of each element of the design. The new design will be investigated against some of the NGN related challenges to prove its efficiency to deliver services. Analysis in terms of performance, flexibility and Deployment Complexity will be performed to explore possible enhancements to the proposed design.

New polyurethane (PU) nanocomposites were prepared from a dispersion of 0 - 5% montmorillonite (MMT) clay with isocyanate and soya oil polyol that was synthesized via transesterification of triglycerides to reduce petroleum dependence. FT-IR spectra indicate the presence of hydrogen bonding between nanoclay and the polymer matrix, whereas the exfoliated structure of clay layers was confirmed by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Optical microscopy, mechanical and thermal analyses were done to investigate significant improvement of the nanocomposites. The results showed PU–3% nanoclay (NC) showed optimum results in mechanical properties such as tensile and flexural strength but the lowest in impact strength.

Palm and soya oils were converted to monoglycerides via transesterification of triglycerides with glycerol by one step process to produce renewable polyols. Thermoplastic polyurethanes (TPPUs) were prepared from the reaction of the monoglycerides which act as polyol with 4,4'-methylenediphenyldiisocyan ate (MDI) whereas, thermosetting polyurethanes (TSPUs) were prepared from the reaction of glycerol, MDI and monoglycerides in one pot. Characterization of the polyurethanes was carried out by FT-IR, 1 H NMR, and iodine value and sol-gel fraction. The TSPUs showed good thermal properties compared to TPPUs as well as TSPUs exhibits good properties in pencil hardness and adhesion, however poorer in flexural and impact strength compared to TPPUs. The higher percentage of cross linked fraction, the higher degree of cross linking occurred, which is due to the higher number of double bond presents in the TSPUs. These were reflected in iodine value test as the highest iodine value of the soya-based thermosetting polyurethanes confirmed the highest degree of cross linking. Polyurethanes based on soya oil showed better properties compared to palm oil. This study is a breakthrough development of polyurethane resins using palm and soya oils as one of the raw materials.

This paper presents a socio-technical study on how humans collectively perceive trustworthiness in a suspicious situation when evoked by computer-mediated communications (CMC). This research was designed through the use of an online game, entitled "Whodunit" to study how collective trust in a virtual scenario can be reflected in untrustworthy cloud environments. We propose that virtual dialogue can provide important clues to understanding an actor's inclination, using the cognitive process of observers' collective trust in a virtual collaborative group. The methodology proposed in this paper is built on research that demonstrates how human "sensors" can detect unusual or unexpected changes in a psychological construct: trustworthiness --- based on observed virtual behavior. The research framework adopts the theory of trustworthiness attribution to model collective trust in virtual interactive environments. Humans "sensors," with limited access to information (e.g., online conversations) make assessments based on subtle observed changes to a person's disposition. This paper concludes that people that rely on "cognitive trust" can identify dispositional changes within untrustworthy scenarios more precisely than people that rely on "emotional trust." In addition, people who have a propensity to trust others more than themselves (lacking confidence in their own abilities) tend to do better identifying the correct murderer.

The title compound, C(27)H(45)Cl, is a second monoclinic polymorph which crystallizes in the space group P2(1) with four crystallographically independent mol-ecules in the asymmetric unit. The structure was previously reported [Bernal et al. (1940 ▶). Philos. Trans. R. Soc. London Ser. B, 239, 135-182; VaniVijayan (1979 ▶). Mol. Cryst. Liq. Cryst.51, 253-264], also in the space group P2(1), but with two unique mol-ecules in the asymmetric unit. As in the previously reported structures, rings A and C in the mol-ecule adopt chair conformations with half-chair conformations for rings B and D. The ring junctions B-C and C-D are trans, whereas the junction A-B is quasi-trans. In the crystal structure, mol-ecules are arranged in a head-to-tail fashion along a and are stacked along the b axis.