Search results for: salt sensitivity

Authors: Tayaba Dastgeer, Farhan Rasheed, Muhammad Saeed, Maqsood Ahmad, Zia Ashraf, Abdul Waheed, Muhammad Kamran, Mohsin Khurshid

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Objectives: The study aimed to determine the efficacy of linezolid against clinical isolates of methicillin-resistant staphylococcus aureus (MRSA). Methodology: This cross-sectional study was conducted in the microbiology department of Allama Iqbal Medical College Lahore from August 2017 to September 2019. Isolates were confirmed as MRSA via the presence of the mec-A gene. Confirmed MRSA isolates were processed for susceptibility testing against different antimicrobials, especially linezolid, via the disc diffusion method. Zone sizes were interpreted according to CLSI guidelines. Results: Various types of clinical samples were included in the study; however, the highest frequency of MRSA isolates was found in pus samples, followed by other clinical samples. Among hospitalized patients, most MRSA isolates were obtained from patients in the surgical ward. Of 243 mec-A gene detected isolates, Vancomycin and linezolid showed 100% susceptibility, chloramphenicol showed declining resistance 78 (32.09%), and emerging sensitivity 165 (67.90%) against MRSA. Conclusion: Linezolid is a very efficient drug against MRSA, but the use of this novel drug must be conserved for vancomycin-resistant Staphylococcus aureus or when more resistant pathogens are suspected.

Keywords: MRSA, chloramphenicol, linezolid, nosocomial infections

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Authors: Tamseela Habib, Muhammad Amjad, Muhammad Edokali, Masome Moeni, Olivia Pickup, Ali Hassanpour

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Nanofluid-assisted steam generation is rapidly attracting attention amongst the scientific community since it can be applied in a wide range of industrial processes. Because of its high absorption rate of solar energy, nanoparticle-based solar steam generation could be a major contributor to many applications, including water desalination, sterilization and power generation. Lithium bromide-based iron oxide nanofluids have been previously studied in steam generation, which showed promising results. However, the efficiency of the system could be improved if a more heat-conductive nanofluid system could be utilised. In the current paper, we report on an experimental investigation of the photothermal conversion properties of functionalised Copper oxide (CuO) nanoparticles used in Lithium Bromide salt solutions. CuO binary nanofluid was prepared by chemical functionalization with polyethyleneimine (PEI). Long-term stability evaluation of prepared binary nanofluid was done by a high-speed centrifuge analyser which showed a 0.06 Instability index suggesting low agglomeration and sedimentation tendencies. This stability is also supported by the measurements from dynamic light scattering (DLS), transmission electron microscope (TEM), and ultraviolet-visible (UV-Vis) spectrophotometer. The fluid rheology is also characterised, which suggests the system exhibits a Newtonian fluid behavior. The photothermal conversion efficiency of different concentrations of CuO was experimentally investigated under a solar simulator. Experimental results reveal that the binary nanofluid in this study can remarkably increase the solar energy trapping efficiency and evaporation rate as compared to conventional fluids due to localized solar energy harvesting by the surface of the nanofluid. It was found that 0.1wt% CuO NP is the optimum nanofluid concentration for enhanced sensible and latent heat efficiencies.

Keywords: nanofluids, vapor absorption refrigeration system, steam generation, high salinity

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Authors: T. Heikkinen, J. Oksman, T. Bragge, A. Nurmi, O. Kontkanen, T. Ahtoniemi

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Motor impairment is an inherent phenotypic feature of several chronic neurodegenerative diseases, and pharmacological therapies aimed to counterbalance the motor disability have a great market potential. Animal models of chronic neurodegenerative diseases display a number deteriorating motor phenotype during the disease progression. There is a wide array of behavioral tools to evaluate motor functions in rodents. However, currently existing methods to study motor functions in rodents are often limited to evaluate gross motor functions only at advanced stages of the disease phenotype. The most commonly applied traditional motor assays used in CNS rodent models, lack the sensitivity to capture fine motor impairments or improvements. Fine motor skill characterization in rodents provides a more sensitive tool to capture more subtle motor dysfunctions and therapeutic effects. Importantly, similar approach, kinematic movement analysis, is also used in clinic, and applied both in diagnosis and determination of therapeutic response to pharmacological interventions. The aim of this study was to apply kinematic gait analysis, a novel and automated high precision movement analysis system, to characterize phenotypic deficits in three different chronic neurodegenerative animal models, a transgenic mouse model (SOD1 G93A) for amyotrophic lateral sclerosis (ALS), and R6/2 and Q175KI mouse models for Huntington’s disease (HD). The readouts from walking behavior included gait properties with kinematic data, and body movement trajectories including analysis of various points of interest such as movement and position of landmarks in the torso, tail and joints. Mice (transgenic and wild-type) from each model were analyzed for the fine motor kinematic properties at young ages, prior to the age when gross motor deficits are clearly pronounced. Fine motor kinematic Evaluation was continued in the same animals until clear motor dysfunction with conventional motor assays was evident. Time course analysis revealed clear fine motor skill impairments in each transgenic model earlier than what is seen with conventional gross motor tests. Motor changes were quantitatively analyzed for up to ~80 parameters, and the largest data sets of HD models were further processed with principal component analysis (PCA) to transform the pool of individual parameters into a smaller and focused set of mutually uncorrelated gait parameters showing strong genotype difference. Kinematic fine motor analysis of transgenic animal models described in this presentation show that this method isa sensitive, objective and fully automated tool that allows earlier and more sensitive detection of progressive neuromuscular and CNS disease phenotypes. As a result of the analysis a comprehensive set of fine motor parameters for each model is created, and these parameters provide better understanding of the disease progression and enhanced sensitivity of this assay for therapeutic testing compared to classical motor behavior tests. In SOD1 G93A, R6/2, and Q175KI mice, the alterations in gait were evident already several weeks earlier than with traditional gross motor assays. Kinematic testing can be applied to a wider set of motor readouts beyond gait in order to study whole body movement patterns such as with relation to joints and various body parts longitudinally, providing a sophisticated and translatable method for disseminating motor components in rodent disease models and evaluating therapeutic interventions.

Keywords: Gait analysis, kinematic, motor impairment, inherent feature

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Authors: A. F. Suleimanov, A. B. Saduakassova, V. S. Pokrovsky, D. V. Vinnikov

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Relevance: Epithelial ovarian cancer (EOC) is the most lethal gynecological malignancy, with relapse occurring in about 70% of advanced cases with poor prognoses. The aim of the study was to evaluate functional visceral fat activity (VAT) evaluated by ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) as a predictor of metastases in epithelial ovarian cancer (EOC). Materials and methods: We assessed 53 patients with histologically confirmed EOC who underwent ¹⁸F-FDG PET/CT after a surgical treatment and courses of chemotherapy. Age, histology, stage, and tumor grade were recorded. Functional VAT activity was measured by maximum standardized uptake value (SUVₘₐₓ) using ¹⁸F-FDG PET/CT and tested as a predictor of later metastases in eight abdominal locations (RE – Epigastric Region, RLH – Left Hypochondriac Region, RRL – Right Lumbar Region, RU – Umbilical Region, RLL – Left Lumbar Region, RRI – Right Inguinal Region, RP – Hypogastric (Pubic) Region, RLI – Left Inguinal Region) and pelvic cavity (P) in the adjusted regression models. We also identified the best areas under the curve (AUC) for SUVₘₐₓ with the corresponding sensitivity (Se) and specificity (Sp). Results: In both adjusted-for regression models and ROC analysis, ¹⁸F-FDG accumulation in RE (cut-off SUVₘₐₓ 1.18; Se 64%; Sp 64%; AUC 0.669; p = 0.035) could predict later metastases in EOC patients, as opposed to age, sex, primary tumor location, tumor grade, and histology. Conclusions: VAT SUVₘₐₓ is significantly associated with later metastases in EOC patients and can be used as their predictor.

Keywords: ¹⁸F-FDG, PET/CT, EOC, predictive value

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Authors: Subrata Kar, Banani Kundu, Papiya Nandy, Ruma Basu, Sukhen Das

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Natural montmorilollite clay is a common ingredient in pharmaceutical products, both as excipients and active support; hence considered as suitable candidate for Drug Delivery System. In this work, cationic detergent CTAB is used to increase the interlayer spacing of Na+-Montmoriollite clay to intercalate curcumin and methotrexate. Methotrexate is a folic acid antagonist, anti-proliferative and immunosuppressive agent; while curcumin is a bioactive constituent of rhizomes of Curcuma longa, possessing remarkable chemo-preventive and anti-inflammatory properties. The resultant inorganic-organic hybrids are characterized by X-ray diffraction (XRD), Infrared spectroscopy (FTIR) and Thermo Gravimetric Analysis (TGA) to confirm successful intercalation of curcumin and Methotrexate within clay layers. Pharmaceutical investigation of the hybrids is explored by studying the drug loading (%), encapsulation efficiency and release kinetics. Finally in-vitro studies are performed using cancer cells to find the effect of released curcumin to improve the sensitivity of clay bound methotrexate to ameliorate cell death compared to their effectiveness when used without the inorganic aluminosilicate vehicle.

Keywords: montmorillonite, methotrexate, curcumin, loading efficiency, release kinetics, anticancer activity

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Authors: Puntarikorn Rungrattanakasin

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Objectives: To develop the trigger tool to warn about the risk of bleeding as an adverse event from warfarin drug usage during admission in Medical Wards of Chumphae Hospital. Methods: A retrospective study was performed by reviewing the medical records for the patients admitted between June 1st,2020- May 31st, 2021. ADEs were evaluated by Naranjo’s algorithm. The international normalized ratio (INR) and events of bleeding during admissions were collected. Statistical analyses, including Chi-square test and Reciever Operating Characteristic (ROC) curve for optimal INR threshold, were used for the study. Results: Among the 139 admissions, the INR range was found to vary between 0.86-14.91, there was a total of 15 bleeding events, out of which 9 were mild, and 6 were severe. The occurrence of bleeding started whenever the INR was greater than 2.5 and reached the statistical significance (p <0.05), which was in concordance with the ROC curve and yielded 100 % sensitivity and 60% specificity in the detection of a bleeding event. In this regard, the INR greater than 2.5 was considered to be an optimal threshold to alert promptly for bleeding tendency. Conclusions: The INR value of greater than 2.5 (>2.5) would be an appropriate trigger tool to warn of the risk of bleeding for patients taking warfarin in Chumphae Hospital.

Keywords: trigger tool, warfarin, risk of bleeding, medical wards

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Authors: P. Saha, R. Ganguly, N. K .Singha, A. Pich

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Microgel, a smart class of material, has drawn attention in the past few years due to its response to external stimuli like temperature, pH, and ionic strength of the solution. Among them, one type of polymer becomes soluble, and the other becomes insoluble in water upon heating displaying upper critical solution temperature (UCST) (e.g., polysulfobetaine, PSB) and lower critical solution temperature (LCST) (e.g., poly(N-vinylcaprolactam, PVCL)) respectively. Polyzwitterions, electrically neutral polymers are biocompatible, biodegradable, and non-cytotoxic in nature, and presence of zwitterionic pendant group in the main backbone makes them stable against temperature and pH variations and strong hydration capability in salt solution promotes them to be used as interfacial bio-adhesion resistance material. Majority of zwitterionic microgels have been synthesized in mini- emulsion technique using free radical polymerization approach. Here, a new route to synthesize dual thermo-responsive PVCL microgels decorated with appreciable amount of zwitterionic PSB chains was developed by a purely water-based surfactant-free reversible addition–fragmentation chain transfer (RAFT) precipitation polymerization. PSB macro-RAFTs having different molecular weights were synthesized and utilized for surface-grafting with PVCL microgels varying the macro-RAFT concentration using N,N′-methylenebis(acrylamide) (BIS) as cross-linker. Increasing the PSB concentration in the PVCL microgels resulted in a linear increase in UCST but decrease in hydrodynamic radius due to strong intrachain coulombic attraction forces acting between the opposite charges present in the zwitterionic groups. Anti- fouling effect was observed on addition of BSA protein solution on the microgel-coated membrane surfaces as studied by fluorescence spectrophotoscopy.

Keywords: microgels, polyzwitterions, upper critical solution temperature-lower critical solution temperature, UCST-LCST, ionic crosslinking

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Authors: Shrey Sharma, Gunjan Kumar Verma

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High density electrical prospecting has been widely used in groundwater investigation, civil engineering and environmental survey. For efficient inversion, the forward modeling routine, sensitivity calculation, and inversion algorithm must be efficient. This paper attempts to provide a brief summary of the past and ongoing developments of the method. It includes reviews of the procedures used for data acquisition, processing and inversion of electrical resistivity data based on compilation of academic literature. In recent times there had been a significant evolution in field survey designs and data inversion techniques for the resistivity method. In general 2-D inversion for resistivity data is carried out using the linearized least-square method with the local optimization technique .Multi-electrode and multi-channel systems have made it possible to conduct large 2-D, 3-D and even 4-D surveys efficiently to resolve complex geological structures that were not possible with traditional 1-D surveys. 3-D surveys play an increasingly important role in very complex areas where 2-D models suffer from artifacts due to off-line structures. Continued developments in computation technology, as well as fast data inversion techniques and software, have made it possible to use optimization techniques to obtain model parameters to a higher accuracy. A brief discussion on the limitations of the electrical resistivity method has also been presented.

Keywords: inversion, limitations, optimization, resistivity

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Authors: Antonio Gioiosa, Simone Doanti, Eric Flumerfelt, Luca Morescalchi, Elena Pedreschi, Gianantonio Pezzullo, Ryan A. Rivera, Franco Spinella

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The Mu2e experiment at Fermilab aims to measure the charged-lepton flavour violating neutrino-less conversion of a negative muon into an electron in the field of an aluminum nucleus. With the expected experimental sensitivity, Mu2e will improve the previous limit of four orders of magnitude. The Mu2e data acquisition (DAQ) system provides hardware and software to collect digitized data from the tracker, calorimeter, cosmic ray veto, and beam monitoring systems. Mu2e’s trigger and data acquisition system (TDAQ) uses otsdaq as its solution. developed at Fermilab, otsdaq uses the artdaq DAQ framework and art analysis framework, under-the-hood, for event transfer, filtering, and processing. Otsdaq is an online DAQ software suite with a focus on flexibility and scalability while providing a multi-user, web-based interface accessible through the Chrome or Firefox web browser. The detector read out controller (ROC) from the tracker and calorimeter stream out zero-suppressed data continuously to the data transfer controller (DTC). Data is then read over the PCIe bus to a software filter algorithm that selects events which are finally combined with the data flux that comes from a cosmic ray veto system (CRV).

Keywords: trigger, daq, mu2e, Fermilab

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Authors: Boor Singh Lalia, Yarjan Abdul Samad, Raed Hashaikeh

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Three different kinds of solid polymer electrolytes were prepared using polyethylene oxide (PEO) as a base polymer, networked cellulose (NC) as a physical support and LiClO4 as a conductive salt for the electrolytes. Networked cellulose, a modified form of cellulose, is a biodegradable and environmentally friendly additive which provides a strong fibrous networked support for structural stability of the electrolytes. Although the PEO/NC/LiClO4 electrolyte retains its structural integrity and mechanical properties at 100oC as compared to pristine PEO-based polymer electrolytes, it suffers from poor ionic conductivity. To improve the room temperature conductivity of the electrolyte, PEO is replaced by the polyethylene glycol (PEG) which is a liquid phase that provides high mobility for Li+ ions transport in the electrolyte. PEG/NC/LiClO4 shows improvement in ionic conductivity compared to PEO/NC/LiClO4 at room temperature, but it is brittle and tends to form cracks during processing. An advanced solid polymer electrolyte with optimum ionic conductivity and mechanical properties is developed by using a ternary system: TEGDME/PEO/NC+LiClO4. At room temperature, this electrolyte exhibits an ionic conductivity to the order of 10-5 S/cm, which is very high compared to that of the PEO/LiClO4 electrolyte. Pristine PEO electrolytes start melting at 65 °C and completely lose its mechanical strength. Dynamic mechanical analysis of TEGDME: PEO: NC (70:20:10 wt%) showed an improvement of storage modulus as compared to the pristine PEO in the 60–120 °C temperature range. Also, with an addition of NC, the electrolyte retains its mechanical integrity at 100 oC which is beneficial for Li-ion battery operation at high temperatures. Differential scanning calorimetry (DSC) and thermal gravimetry analysis (TGA) studies revealed that the ternary polymer electrolyte is thermally stable in the lithium ion battery operational temperature range. As-prepared polymer electrolyte was used to assemble LiFePO4/ TEGDME/PEO/NC+LiClO4/Li half cells and their electrochemical performance was studied via cyclic voltammetry and charge-discharge cycling.

Keywords: solid polymer electrolyte, ionic conductivity, mechanical properties, lithium ion batteries, cyclic voltammetry

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Authors: Zhu Zhizheng, Huang Yong, Li Tong

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In the context of land and space development and resource environmental protection. Due to its special geographical location, mountain-plain transition zones are limited by many factors such as topography, mountain forest protection, etc., and their ecology is also more sensitive, with the characteristics of disaster susceptibility and resource gradient. Taking Dujiangyan City, Chengdu as an example, this paper establishes resilience evaluation indicators on the basis of ecological suitability evaluation through the analysis of current situation data and relevant policies: water conservation evaluation, soil and water conservation evaluation, biodiversity evaluation, soil erosion sensitivity evaluation, etc. Based on GIS spatial analysis, the ecological suitability and resilience evaluation results of Dujiangyan city were obtained by disjunction operation. The ecological resilience level of Dujiangyan city was divided into three categories: high, medium and low, with an area ratio of 50.81%, 16.4% and 32.79%, respectively. This paper can provide ideas for solving the contradiction between man and land in the mountain-plain transition zones, and also provide a certain basis for the construction of regional ecological protection and the delineation of three zones and three lines.

Keywords: urban and rural planning, ecological resilience, dujiangyan city, mountain-plain transition zones

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Authors: Mohamed A. Alhammad, Hadia A. Abou-Donia, Mona H. Hashish, Mohamed N. Massoud

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Background: Rotavirus is the leading etiologic agent of severe diarrheal disease in infants and young children worldwide. The present study was aimed 1) to detect rotavirus infection as a cause of diarrhoea among children under 5 years of age using the two serological methods (ELISA and LA) and the PCR technique (2) to evaluate the three methodologies used for human RV detection in stool samples. Materials and Methods: This study was carried out on 247 children less than 5 years old, diagnosed clinically as acute gastroenteritis and attending Alexandria University Children Hospital at EL-Shatby. Rotavirus antigen was screened by ELISA and LA tests in all stool samples, whereas only 100 samples were subjected to RT-PCR method for detection of rotavirus RNA. Results: Out of the 247 studied cases with diarrhoea, rotavirus antigen was detected in 83 (33.6%) by ELISA and 73 (29.6%) by LA, while the 100 cases tested by RT-PCR showed that 44% of them had rotavirus RNA. Rotavirus diarrhoea was significantly presented with a marked seasonal peak during autumn and winter (61.4%). Conclusion: The present study confirms the huge burden of rotavirus as a major cause of acute diarrhoea in Egyptian infants and young children. It was concluded that; LA is equal in sensitivity to ELISA, ELISA is more specific than LA, and RT-PCR is more specific than ELISA and LA in diagnosis of rotavirus infection.

Keywords: rotavirus, diarrhea, immunoenzyme techniques, latex fixation tests, RT-PCR

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Authors: Mohammed Alasel, Michael Keusgen

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Gold is a noble metal; in its nano-scale level (e.g. spherical nanoparticles), the conduction electrons are triggered to collectively oscillate with a resonant frequency when certain wavelengths of electromagnetic radiation interact with its surface; this phenomenon is known as surface plasmon resonance (SPR). SPR is responsible for giving the gold nanoparticles its intense red color depending mainly on its size, shape and distance between nanoparticles. A decreased distance between gold nanoparticles results in aggregation of them causing a change in color from red to blue. This aggregation enables gold nanoparticles to serve as a sensitive biosensoric indicator. In the proposed work, gold nanoparticles were modified with two proteins: i) Borrelia antigen, variable lipoprotein surface-exposed protein (VlsE), and ii) protein A. VlsE antigen induces a strong antibody response against Lyme disease and can be detected from early to late phase during the disease in humans infected with Borrelia. In addition, it shows low cross-reaction with the other non-pathogenic Borrelia strains. The high specificity of VlsE antigen to anti-Borrelia antibodies, combined simultaneously with the high specificity of protein A to the Fc region of all IgG human antibodies, was utilized to develop a rapid test for serological point of care diagnosis of borreliosis in human serum. Only in the presence of anti-Borrelia antibodies in the serum probe, an aggregation of gold nanoparticles can be observed, which is visible by a concentration-dependent colour shift from red (low IgG) to blue (high IgG). Experiments showed it is clearly possible to distinguish between positive and negative sera samples using a simple suspension of the two-protein modified gold nanoparticles in a very short time (30 minutes). The proposed work showed the potential of using such modified gold nanoparticles generally for serological diagnosis. Improved specificity and reduced assay time can be archived in applying increased salt concentrations combined with decreased pH values (pH 5).

Keywords: gold nanoparticles, gold aggregation, serological diagnosis, protein A, lyme borreliosis

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Authors: Shu-Hui Wen, Wei-Chuan Chang, Hsien-Chang Wu

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Background: Little is known about the benefits and risks of use of Chinese herbal medicine (CHM) in conditions related to hormone therapy (HT) use on the risk of ischemic stroke (IS). The aim of this study is to explore the risk of IS in menopausal women treated with HT and CHM. Materials and methods: A total of 32,441 menopausal women without surgical menopause aged 40- 65 years were selected from 2003 to 2010 using the 2-million random samples of the National Health Insurance Research Database in Taiwan. According to the medication usage of HT and CHM, we divided the current and recent users into two groups: an HT use-only group (n = 4,989) and an HT/CHM group (n = 9,265). Propensity-score matching samples (4,079 pairs) were further created to deal with confounding by indication. The adjusted hazard ratios (HR) of IS during HT or CHM treatment were estimated by the robust Cox proportional hazards model. Results: The incidence rate of IS in the HT/CHM group was significantly lower than in the HT group (4.5 vs. 12.8 per 1000 person-year, p < 0.001). Multivariate analysis results indicated that additional CHM use was significant with a lower risk of IS (HR = 0.3; 95% confidence interval, 0.21-0.43). Further subgroup analyses and sensitivity analyses had similar findings. Conclusion: We found that combined use of HT and CHM was associated with a lower risk for IS than HT use only. Further study is needed to examine possible mechanism underlying this association.

Keywords: Chinese herbal medicine, hormone therapy, ischemic stroke, menopause

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Authors: Giovanni Menichini, Salvatore Giacomo Morano, Gloria Terenzi, Luca Salvatori, Maurizio Orlando

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The “Guidelines for Risk Classification, Safety Assessment, and Structural Health Monitoring of Existing Bridges” were recently approved by the Italian Government to define technical standards for managing the national network of existing bridges. These guidelines provide a framework for risk mitigation and safety assessment of bridges, which are essential elements of the built environment and form the basis for the operation of transport systems. Within the guideline framework, a workflow based on three main points was proposed: (1) risk-based, i.e., based on typical parameters of hazard, vulnerability, and exposure; (2) multi-level, i.e., including six assessment levels of increasing complexity; and (3) multirisk, i.e., assessing structural/foundational, seismic, hydrological, and landslide risks. The paper focuses on applying the Italian Guidelines to specific case studies, aiming to identify the parameters that predominantly influence the determination of the “class of attention”. The significance of each parameter is determined via sensitivity analysis. Additionally, recommendations for enhancing the process of assigning the class of attention are proposed.

Keywords: bridge safety assessment, Italian guidelines implementation, risk classification, structural health monitoring

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Authors: A. Sacko, H. Nyoni, T. A. M. Msagati, B. Ntsendwana

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Carbon based materials to target environmental pollutants have become increasingly recognized in science. Electrochemical methods using carbon based materials are notable methods for high sensitive detection of organic pollutants in air. It is therefore in this light that exfoliated graphite electrode was fabricated for electrochemical analysis of PAHs in urban atmospheric air. The electrochemical properties of the graphite electrode were studied using CV and EIS in the presence of acetate buffer supporting electrolyte with 2 Mm ferricyanide as a redox probe. The graphite electrode showed enhanced current response which confirms facile kinetics and enhanced sensitivity. However, the peak to peak (DE) separation increased as a function of scan rate. The EIS showed a high charger transfer resistance. The detection phenanthrene on the exfoliated graphite was studied in the presence of acetate buffer solution at PH 3.5 using DPV. The oxidation peak of phenanthrene was observed at 0.4 V. Under optimized conditions (supporting electrolyte, pH, deposition time, etc.). The detection limit observed was at 5x 10⁻⁸ M. Thus the results demonstrate with further optimization and modification lower concentration detection can be achieved.

Keywords: electrochemical detection, exfoliated graphite, PAHs (polycyclic aromatic hydrocarbons), urban air

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Authors: Héctor Rivera-Gómez, Eva Selene Hernández-Gress, Oscar Montaño-Arango, Jose Ramon Corona-Armenta

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This research studies the joint production, maintenance and subcontracting control policy for an unreliable deteriorating manufacturing system. Production activities are controlled by a derivation of the Hedging Point Policy, and given that the system is subject to deterioration, it reduces progressively its capacity to satisfy product demand. Multiple deterioration effects are considered, reflected mainly in the quality of the parts produced and the reliability of the machine. Subcontracting is available as support to satisfy product demand; also overhaul maintenance can be conducted to reduce the effects of deterioration. The main objective of the research is to determine simultaneously the production, maintenance and subcontracting rate which minimize the total incurred cost. A stochastic dynamic programming model is developed and solved through a simulation-based approach composed of statistical analysis and optimization with the response surface methodology. The obtained results highlight the strong interactions between production, deterioration and quality which justify the development of an integrated model. A numerical example and a sensitivity analysis are presented to validate our results.

Keywords: subcontracting, optimal control, deterioration, simulation, production planning

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Authors: Kashif Hassan, M.A. Ahanger

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Floods have become more frequent and severe due to effects of global climate change and human alterations of the natural environment. Flood prediction/ forecasting and control is one of the greatest challenges facing the world today. The forecast of floods is achieved by the use of hydraulic models such as HEC-RAS, which are designed to simulate flow processes of the surface water. Extreme flood events in river Jhelum , lasting from a day to few are a major disaster in the State of Jammu and Kashmir, India. In the present study HEC-RAS model was applied to two different reaches of river Jhelum in order to estimate the flood levels corresponding to 25, 50 and 100 year return period flood events at important locations and to deduce flood vulnerability of important areas and structures. The flow rates for the two reaches were derived from flood-frequency analysis of 50 years of historic peak flow data. Manning's roughness coefficient n was selected using detailed analysis. Rating Curves were also generated to serve as base for determining the boundary conditions. Calibration and Validation procedures were applied in order to ensure the reliability of the model. Sensitivity analysis was also performed in order to ensure the accuracy of Manning's n in generating water surface profiles.

Keywords: flood plain, HEC-RAS, Jhelum, return period

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Authors: Trieu Anh Ngoc, Nguyen Quang Kim

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Located at the downstream of the Mekong Delta, the Vietnamese Mekong Delta is well-known as 'rice bowl' of Vietnam. The Vietnamese Mekong Delta experiences widespread flooding annually where is habitat for about 17 million people. The economy of this region mainly depends on the agricultural productivities. The suspended sediment load in the Mekong River plays an important role in carrying contaminants and nutrients to the delta and changing the geomorphology of the delta river system. In many past decades, flooding and suspended sediment were considered as indispensable factors in agricultural cultivations. Although flooding in the wet season caused serious inundation in paddy field and affected livelihoods, it is an effective facility for flushing acid and saline to this area - alluvial soil heavily contaminated with acid and salt intrusion. In addition, sediment delivery to this delta contained rich-nutrients distributed and deposited on the fields through flooding process. In recent decades, the changing of flow and sediment transport have been strongly and clearly occurring due to upstream dam development and climate change. However, effects of sediment delivery on agricultural cultivations were less attention. This study investigated the impacts of upstream flow on sediment distribution in the Vietnamese Mekong Delta. Flow fluctuation and sediment distribution were simulated by the Mike 11 model, including hydrodynamics model and advection-dispersion model. Various scenarios were simulated based on anticipated upstream discharges. Our findings indicated that sediment delivery into the Vietnamese Mekong Delta come from not only Tien River but also border of Cambodia floodplains. Sediment distribution in the Vietnamese Mekong Delta is dramatically changed by the distance from the main rivers and the secondary channels. The dam development in the upstream is one of the major factors leading a decrease in sediment discharge as well as sediment deposition. Moreover, sea level rise partially contributed to decrease in sediment transport and change of sediment distribution between upstream and downstream of the Vietnamese Mekong Delta.

Keywords: sediment transport, sea level rise, climate change, Mike Model

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Authors: Zahra Abdolkarimi, Naser Zourikalatehsamad,

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Up to 40 years ago, after recognition of epilepsy, it was generally believed that these attacks occurred randomly and suddenly. However, thanks to the advance of mathematics and engineering, such attacks can be predicted within a few minutes or hours. In this way, various algorithms for long-term prediction of the time and frequency of the first attack are presented. In this paper, by considering the nonlinear nature of brain signals and dynamic recorded brain signals, ANFIS model is presented to predict the brain signals, since according to physiologic structure of the onset of attacks, more complex neural structures can better model the signal during attacks. Contribution of this work is the co-evolution algorithm for optimization of ANFIS network parameters. Our objective is to predict brain signals based on time series obtained from brain signals of the people suffering from epilepsy using ANFIS. Results reveal that compared to other methods, this method has less sensitivity to uncertainties such as presence of noise and interruption in recorded signals of the brain as well as more accuracy. Long-term prediction capacity of the model illustrates the usage of planted systems for warning medication and preventing brain signals.

Keywords: co-evolution algorithms, brain signals, time series, neural networks, ANFIS model, physiologic structure, time prediction, epilepsy suffering, illustrates model

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Authors: M. Bodner, M. Scampicchio

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Fourier Transform Infrared (FT-IR) spectroscopy coupled with chemometrics was used to distinguish between butter samples and non-butter samples. Further, quantification of the content of margarine in adulterated butter samples was investigated. Fingerprinting region (1400-800 cm^–1) was used to develop unsupervised pattern recognition (Principal Component Analysis, PCA), supervised modeling (Soft Independent Modelling by Class Analogy, SIMCA), classification (Partial Least Squares Discriminant Analysis, PLS-DA) and regression (Partial Least Squares Regression, PLS-R) models. PCA of the fingerprinting region shows a clustering of the two sample types. All samples were classified in their rightful class by SIMCA approach; however, nine adulterated samples (between 1% and 30% w/w of margarine) were classified as belonging both at the butter class and at the non-butter one. In the two-class PLS-DA model’s (R² = 0.73, RMSEP, Root Mean Square Error of Prediction = 0.26% w/w) sensitivity was 71.4% and Positive Predictive Value (PPV) 100%. Its threshold was calculated at 7% w/w of margarine in adulterated butter samples. Finally, PLS-R model (R² = 0.84, RMSEP = 16.54%) was developed. PLS-DA was a suitable classification tool and PLS-R a proper quantification approach. Results demonstrate that FT-IR spectroscopy combined with PLS-R can be used as a rapid, simple and safe method to identify pure butter samples from adulterated ones and to determine the grade of adulteration of margarine in butter samples.

Keywords: adulterated butter, margarine, PCA, PLS-DA, PLS-R, SIMCA

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Authors: Khaled Sandjak, Boualem Tiliouine

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Structural analysis of flexible pavements has been and still is currently performed using multi-layer elastic theory. However, for thinly surfaced pavements subjected to low to medium volumes of traffics, the importance of non-linear stress-strain behaviour of unbound granular materials (UGM) requires the use of more sophisticated numerical models for structural design and performance of such pavements. In the present work, nonlinear unbound aggregates constitutive model is implemented within an axisymmetric finite element code developed to simulate the nonlinear behaviour of pavement structures including two local aggregates of different mineralogical nature, typically used in Algerian pavements. The performance of the mechanical model is examined about its capability of representing adequately, under various conditions, the granular material non-linearity in pavement analysis. In addition, deflection data collected by falling weight deflectometer (FWD) are incorporated into the analysis in order to assess the sensitivity of critical pavement design criteria and pavement design life to the constitutive model. Finally, conclusions of engineering significance are formulated.

Keywords: FWD backcalculations, finite element simulations, Nonlinear resilient behaviour, pavement response and performance, RLT test results, unbound granular materials

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Authors: P. M. G. Pathiraja, P. Egodawatta, A. Goonetilleke, V. S. J. Te'o

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The production and use of Polychlorinated biphenyls (PCBs), a group of synthetic halogenated hydrocarbons have been restricted worldwide due to its toxicity and categorized as one of the twelve priority persistent organic pollutants (POP) by the Stockholm Convention. Low reactivity and high chemical stability of PCBs have made them highly persistent in the environment and bio-concentration and bio-magnification along the food chain contribute to multiple health impacts in humans and animals. Remediating environments contaminated with PCBs is a challenging task for decades. Use of microorganisms for remediation of PCB contaminated soils and sediments have been widely investigated due to the potential of breakdown these complex contaminants with minimum environmental impacts. To achieve an effective bioremediation of polychlorinated biphenyls (PCBs) contaminated environments, microbes were sourced from environmental samples and tested for their ability to hydrolyze PCBs under different conditions. Comparison of PCB degradation efficiencies of four naturally occurring facultative bacterial cultures isolated through selective enrichment under aerobic and anaerobic conditions were simultaneously investigated in minimal salt medium using 50 mg/L Aroclor 1260, a commonly used commercial PCB mixture as the sole source of carbon. The results of a six-week study demonstrated that all the tested facultative Achromobacter, Ochrobactrum, Lysinibacillus and Pseudomonas strains are capable of degrading PCBs under both anaerobic and aerobic conditions while assisting hydrophobic PCBs to make solubilize in the aqueous minimal medium. Overall, the results suggest that some facultative bacteria are capable of effective in degrading PCBs under anaerobic conditions through reductive dechlorination and under aerobic conditions through oxidation. Therefore, use of suitable facultative microorganisms under combined anaerobic-aerobic conditions and combination of such strains capable of solubilization and breakdown of PCBs has high potential in achieving higher PCB removal rates.

Keywords: bioremediation, combined anaerobic-aerobic degradation, facultative microorganisms, polychlorinated biphenyls

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Authors: M. Dahiru, O. I. Enabulele

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The research wish to investigate the occurrence of multidrug- resistant Acinetobacter, in carrot and estimate the role of carrot in its transmission, in a rapidly growing urban population. Thus, 50 carrot samples were collected from Jakara wastewater irrigation farms and analyzed on MacConkey agar and screened by Microbact 24E (Oxoid) and susceptibility of isolates tested against 10 commonly used antibiotics. Acinetobacter baumannii and A. lwoffii were isolated in 22.00% and 16% of samples respectively. Resistance to ceporex and penicillin of 36.36% and 27.27% in A. baumannii, and sensitivity to ofloxacin, pefloxacin, gentimycin and co-trimoxazole, were observed. However, for A. lwoffii apart from 37.50% resistance to ceporex, it was also resistant to all other drugs tested. There was a similarity in the resistant shown by A. baumannii and A. lwoffii to fluoroquinolones drugs and β- lactame drugs families in addition to between sulfonamide and animoglycoside demonstrated by A. lwoffii. Interestingly, when resistant similarities to different antibiotics were compared for A. baumannii and A. lwoffii as a whole, significant correlation was observed at P < 0.05 to CPX to NA (46.2%), and SXT to AU (52.6%) respectively, and high multi drug resistance (MDR) of 27.27% and 62.50% by A. baumannii and A. lwoffii respectively and overall MDR of 42.11% in all isolates. The occurrence of multidrug-resistance pathogen in carrot is a serious challenge to public health care, especially in a rapidly growing urban population where subsistence agriculture contributes greatly to urban livelihood and source of vegetables.

Keywords: urban agriculture, public health, fluoroquinolone, sulfonamide, multidrug-resistance

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Authors: Rohollah Ghasemi, Arvin Ghorbani

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This study investigates the effect of austempering temperature on microstructure and scratch behavior of the austempered heat-treated compacted graphite irons. The as-cast was used as base material for heat treatment practices. The samples were extracted from as-cast ferritic CGI pieces and were heat treated under austenitising temperature of 900°C for 60 minutes which followed by quenching in salt-bath at different austempering temperatures of 275°C, 325°C and 375°C. For all heat treatments, an austempering holding time of 30 minutes was selected for this study. Light optical microscope (LOM) and scanning electron microscope (SEM) and electron back scattered diffraction (EBSD) analysis confirmed the ausferritic matrix formed in all heat-treated samples. Microscratches were performed under the load of 200, 600 and 1000 mN using a sphero-conical diamond indenter with a tip radius of 50 μm and induced cone angle 90° at a speed of 10 μm/s at room temperature ~25°C. An instrumented nanoindentation machine was used for performing nanoindentation hardness measurement and microscratch testing. Hardness measurements and scratch resistance showed a significant increase in Brinell, Vickers, and nanoindentation hardness values as well as microscratch resistance of the heat-treated samples compared to the as-cast ferritic sample. The increase in hardness and improvement in microscratch resistance are associated with the formation of the ausferrite matrix consisted of carbon-saturated retained austenite and acicular ferrite in austempered matrix. The maximum hardness was observed for samples austempered at 275°C which resulted in the formation of very fine acicular ferrite. In addition, nanohardness values showed a quite significant variation in the matrix due to the presence of acicular ferrite and carbon-saturated retained austenite. It was also observed that the increase of austempering temperature resulted in increase of volume of the carbon-saturated retained austenite and decrease of hardness values.

Keywords: austempered CGI, austempering, scratch testing, scratch plastic deformation, scratch hardness

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Authors: Niki K. Burns, James R. Pearson, Paul G. Stevenson, Xavier A. Conlan

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In Australian state Victoria, synthetic cannabinoids have recently been made illegal under an amendment to the drugs, poisons and controlled substances act 1981. Identification of synthetic cannabinoids in popular brands of ‘incense’ and ‘potpourri’ has been a difficult and challenging task due to the sample complexity and changes observed in the chemical composition of the cannabinoids of interest. This study has developed analytical methodology for the targeted extraction and determination of synthetic cannabinoids available pre-ban. A simple solvent extraction and solid phase extraction methodology was developed that selectively extracted the cannabinoid of interest. High performance liquid chromatography coupled with UV‐visible and chemiluminescence detection (acidic potassium permanganate and tris (2,2‐bipyridine) ruthenium(III)) were used to interrogate the synthetic cannabinoid products. Mass spectrometry and nuclear magnetic resonance spectroscopy were used for structural elucidation of the synthetic cannabinoids. The tris(2,2‐bipyridine)ruthenium(III) detection was found to offer better sensitivity than the permanganate based reagents. In twelve different brands of herbal incense, cannabinoids were extracted and identified including UR‐144, XLR 11, AM2201, 5‐F‐AKB48 and A796‐260.

Keywords: electrospray mass spectrometry, high performance liquid chromatography, solid phase extraction, synthetic cannabinoids

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Authors: Lojain Suliman, Xinrong Liu, Xiaohan Zhou

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Since most tunnels are built in crowded metropolitan settings, the excavation process must take place in highly condensed locations, including high-density cities. In this way, the tunnels are typically located close together, which leads to more interaction between the parallel existing tunnels, and this, in turn, leads to more settlement. This research presents an examination of the impact of a large-scale tunnel excavation on two forms of settlement: surface settlement and settlement surrounding the tunnel. Additionally, research has been done on the properties of interactions between two and three parallel tunnels. The settlement has been evaluated using three primary techniques: theoretical modeling, numerical simulation, and data monitoring. Additionally, a parametric investigation on how distance affects the settlement characteristic for parallel tunnels with short distances has been completed. Additionally, it has been observed that the sequence of excavation has an impact on the behavior of settlements. Nevertheless, a comparison of the model test and numerical simulation yields significant agreement in terms of settlement trend and value. Additionally, when compared to the FEM study, the suggested analytical solution exhibits reduced sensitivity in the settlement prediction. For example, the settlement of the small tunnel diameter does not appear clearly on the settlement curve, while it is notable in the FEM analysis. It is advised, however, that additional studies be conducted in the future employing analytical solutions for settlement prediction for parallel tunnels.

Keywords: settlement, FEM, analytical solution, parallel tunnels

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Authors: Yayan Rahayani

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Transnational Education (TNE) encompasses mobile and diverse student cohorts, a complex array of educational programs, and a range of providers that serve students across countries in a multicultural setting. In Australia, education is the fourth largest industry that contributes to economic prosperity, and Australia relies heavily on international students to support it. There is a concern that TNE in Australia is limited by a lack of understanding regarding cultural sensitivity towards international students. This research will contribute to the theories of Culturally Responsive Pedagogy (CRP) by incorporating religion as a dimension of culture. This study will also investigate TNE practices provided for educators from culturally diverse backgrounds. The focus of this paper will examine TNE programs in Australia with a focus on Indonesian teachers to examine the extent that they are supported culturally and religiously within the programs. The study an ethnographically-informed case study approach using in-depth interviews. The preliminary results of the study highlight the lack of focus given to the local context of participants. Whilst programs may take into consideration the religious and cultural needs of the participants, the pedagogical focus of the content does not address the local and specific contexts of the participants who will return to Indonesia to teach.

Keywords: culturally responsive pedagogy, professional development, teacher training, transnational education

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Authors: Lamla Thungathaa, Conrad Mahlasea, Lisa Ngcebesha

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1,4-Diamino-3,6-dinitropyrazolo[4,3-c]pyrazole (LLM-119) and its structural isomer 3,6-dinitropyrazolo[3,4-c]pyrazole-1,4(6H)-diamine were designed by structural reorientation of the fused pyrazole rings and their respective substituents (-NO2 and -NH2). Structural reorientation involves structural rearrangement which result in different structural isomers, employing this approach, six structural isomers of LLM-119 were achieved. The effect of structural reorientation (isomerisation and derivatives) on the enthalpy of formation, detonation properties, impact sensitivity, and density of these molecules is studied Computationally. The computational method used are detailed in the document and they yielded results that are close to the literature values with a relative error of 2% for enthalpy of formation, 2% for density, 0.05% for detonation velocity, and 4% for detonation pressure. The correlation of the structural reorientation to the calculated thermochemical and detonation properties of the molecules indicated that molecules with a -NO2 group attached to a Carbon atom and -NH2 connected to a Nitrogen atom maximize the enthalpy of formation and detonation velocity. The joining of pyrazole molecules has less effect on these parameters. It was seen that density and detonation pressure improved when both –NO2 or -NH2 functional groups were on the same side of the molecular structure. The structural reorientation gave rise to 3,4-dinitropyrazolo[3,4-c]pyrazole-1,6-diamine which exhibited optimal density and detonation performance compared to other molecules.

Keywords: LLM-119, fused rings, azole, structural isomers, detonation properties

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Authors: Arjun Paul, Adrijit Goswami

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In our present work, an economic order quantity inventory model with shortages is developed where holding cost is expressed as linearly increasing function of time and demand rate is a ramp type function of time. The items considered in the model are deteriorating in nature so that a small fraction of the items is depleted with the passage of time. In order to consider a more realistic situation, the deterioration rate is assumed to follow a continuous uniform distribution with the parameters involved being triangular fuzzy numbers. The inventory manager offers his customer a discount in case he is willing to backorder his demand when there is a stock-out. The optimum ordering policy and the optimum discount offered for each backorder are determined by minimizing the total cost in a replenishment interval. For better illustration of our proposed model in both the crisp and fuzzy sense and for providing richer insights, a numerical example is cited to exemplify the policy and to analyze the sensitivity of the model parameters.

Keywords: fuzzy deterioration rate, price discount on backorder, ramp type demand, shortage, time varying holding cost

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