Higher Initial Values Research Articles

Sperm processing methods effectively reduce the DNA fragmentation index in samples with high initial values

The DNA fragmentation index (DFI) in spermatozoa is correlated to in vivo fertility in animals and outcomes in Human Assisted Reproductive Techniques (ARTs). Different sperm selection methods aim to select the most viable sperm population and reduce the DFI after processing. However, it remains unclear which selection method most efficiently reduces DFI and to what extent initial levels in raw semen can be improved to justify the use of these alternative procedures. We hypothesized that sperm selection methods would efficiently reduce the percentage of cells with DNA damage mainly to samples with high initial values. In this study we evaluated frozen-thawed equine spermatozoa from 12 different stallions subjected to four different treatments as follows: i) control / no selection (CN); ii) density gradient centrifugation (DGC); iii) swim up (SU); and iv) a microfluidic chamber (MF). After processing, DFI levels were evaluated based on the percentage of cells outside of the main population (COMPαt) from the Sperm Chromatin Structure Assay (SCSA) as described by Evenson et al., (2013). Levels of COMPαt in the control samples (CN) were used to categorize them as LOW and HIGH based on a median split (Mdn:12.37%). Statistical analysis was performed using R (R Core Team, Vienna, Austria, v3.6.0) to fit a mixed linear regressionmodel. Fixed effects in the model included treatment (CN, DGC, SU and MF) and initial DFI levels (LOW or HIGH). Random effect in the model included stallion (n=12) and effects were retained in the model when p<0.05. There was a significant interaction between treatment and initial DNA fragmentation levels (p<0.00001). In samples with HIGH DFI, COMPαt had a mean of (20.44% ±1.68) for CN and was not significantly different from samples processed by DGC (14.36%±1.68; p=0.07). However, a significant reduction in COMPαt was observed after SU (2.97% ± 1.68; p<0.0001) and MF (1.95% ± 1.68; p<0.0001) in this group. On the other hand, among samples in the LOW DFI group, COMPαt had a mean of (8.32% ±1.68) for CN, which was not significantly different when compared to DGC (7.34%±1.68; p=0.99), SU (3.24%±1.68; p=0.2) or MF (2.07% ±1.68; p=0.059) selection methods. These results demonstrate that SU and MF were the most effective at reducing the percentage of cells with DNA fragmentation (COMPαt) when the initial DFI was considered HIGH. However, in samples with LOW DFI, there was no significant improvement in COMPαt by any selection method. Clinical categorization of initial sperm DFI may be warranted to determine the fecundity of sires and be useful for selecting appropriate sperm selection methods for equine ARTs.

Influence of TiN Coating on the Drawing Force and Friction Coefficient in the Deep Drawing Process of AlMg4.5Mn0.7 Thin Sheets.

The influence of various process parameters on the deep drawing process is a current research topic in sheet metal forming technology. Starting from the application of the previously constructed original testing device, an original tribological model was developed based on the process of sheet metal strip sliding between flat contact surfaces under variable pressures. A complex experiment was executed using an Al alloy sheet, tool contact surfaces of different roughness, two types of lubricants and variable contact pressures. The procedure included analytically pre-defined contact pressure functions based on which, for each of the mentioned conditions, the dependencies of the drawing forces and friction coefficients were obtained. The pressure in function P1 constantly decreased from a high initial value until the minimum, while in function P3 the pressure increased until the minimum value at the halfway point of the stroke, after which it increased up to the initial value. On the other hand, the pressure in function P2 constantly increased from the initial minimum value until the maximum value, while in function P4 the pressure increased until reaching the maximum value at the halfway point of the stroke, after which it decreased to the minimum value. This enabled the determination of the influence of tribological factors on the process parameters of intensity of traction (deformation force) and coefficient of friction. The pressure functions starting with decreasing trends produced higher values for the traction forces and the friction coefficient. In addition, it was established that the roughness of the contact surfaces of the tool, especially those with titanium nitride coating, has a significant influence on the process parameters. For surfaces of lower roughness (polished), a tendency of the Al thin sheet to form a glued-on layer was noticed. This was especially prominent for lubrication with MoS2-based grease under conditions of high contact pressure (functions P1 and P4 at the beginning of the contact).

Selected Serum Markers Associated with Pathogenesis and Clinical Course of Type 1 Diabetes in Pediatric Patients-The Effect of Disease Duration.

Biochemical abnormalities in the course of type 1 diabetes (T1D) may cause the production/activation of various proteins and peptides influencing treatment and causing a risk of complications. The aim of this study was to assess concentrations of selected serum substances involved in the pathogenesis and course of T1D and to correlate their concentrations with the duration of T1D. The study included patients with T1D (n = 156) at the age of 3-17, who were divided according to the duration of the disease into those newly diagnosed (n = 30), diagnosed after 3-5 (n = 77), 6-7 (n = 25), and over 7 (n = 24) years from the onset of T1D, and age-matched healthy controls (n = 30). Concentrations of amylin (IAPP), proamylin (proIAPP), catestatin (CST), chromogranin A (ChgA), nerve growth factor (NFG), platelet-activating factor (PAF), uromodulin (UMOD), and intestinal fatty acid binding protein (I-FABP) were measured in sera using immunoenzymatic tests. There were significant differences in concentrations of all the substances except UMOD and NGF between T1D patients and healthy children. The duration of the disease affected concentrations of CST, ChgA, PAF, and NGF, i.e., proteins/peptides which could have an impact on the course of T1D and the development of complications. In long-term patients, a decrease in concentrations of CST and ChgA, and an increase in PAF concentrations were found. In the case of NGF, a decrease was observed after the initial high values, followed by an increase over 7 years after T1D diagnosis. Concluding, the results show that concentrations of selected serum indicators may change in the course of T1D. Further studies are needed to establish whether these indicators could be used in the context of predicting long-term complications.

Current collectors based on multiwalled carbon-nanotubes and few-layer graphene for enhancing the conversion process in scalable lithium-sulfur battery

We investigated herein the morphological, structural, and electrochemical features of electrodes using a sulfur (S)-super P carbon (SPC) composite (i.e., S@SPC-73), and including few-layer graphene (FLG), multiwalled carbon nanotubes (MWCNTs), or a mixture of them within the current collector design. Furthermore, we studied the effect of two different electron-conducting agents, that is, SPC and FLG, used in the slurry for the electrode preparation. The supports have high structural crystallinity, while their morphologies are dependent on the type of material used. Cyclic voltammetry (CV) shows a reversible and stable conversion reaction between Li and S with an activation process upon the first cycle leading to the decrease of cell polarization. This activation process is verified by electrochemical impedance spectroscopy (EIS) with a decrease of the resistance after the first CV scan. Furthermore, CV at increasing scan rates indicates a Li+ diffusion coefficient (D) ranging between 10−9 and 10−7 cm2·s−1 in the various states of charge of the cell, and the highest D value for the electrodes using FLG as electron-conducting agent. Galvanostatic tests performed at constant current of C/5 (1 C = 1675 mA·gS−1) show high initial specific capacity values, which decrease during the initial cycles due to a partial loss of the active material, and subsequently increase due to the activation process. All the electrodes show a Coulombic efficiency higher than 97% upon the initial cycles, and a retention strongly dependent on the electrode formulation. Therefore, this study suggests a careful control of the electrode in terms of current collector design and slurry composition to achieve good electrode morphology, mechanical stability, and promising electrochemical performance in practical Li-S cells.

Valorization of isocyanates using castor oil-based protective strategies: Performance and comparison as waterborne adhesive additives

The violent and uncontrolled reaction of using isocyanates as waterborne additives limits the operation and product quality. Herein, castor oil-based isocyanates (polymethylene polyphenyl polyisocyanate, PAPI) that are protected by different strategies (hydrophobic, emulsified and solid powder) to enable water compatibility are developed and compared, targeting to mitigate these shortcomings. The effectiveness of these approaches is explored by a battery of characterization methods, including chemical titration, optical microscope, FTIR, TG, DSC, and wood adhesion performance. The storage stability of composite adhesives consisting of modified PAPI extends by at least eight times. The use of emulsified PAPI achieves the optimal bonding performance, resulting in increase of the wet strength I up to 240 % compared with pure PAPI when the dosage is 25 wt %. The underlying mechanism relates to high initial value of -NCO, uniform dispersion of isocyanate droplets in the emulsion, and slow post-curing process. These strategies offer effective and affordable routes to prepare and select proper isocyanates on design and construction of environmentally-friendly, low-cost and high-performance waterborne composite materials.

Comparison and discussion of intelligent optimization algorithms based on magnetic localization systems for improving the initial value defects of the L-M Algorithm

Magnetic localization techniques are used in in vivo therapy, drug delivery, and surgical localization widely due to their ability to locate in an unobstructed environment precisely. The Levenberg-Marquardt (L-M) algorithm is one of the most common magnetic localization algorithms due to its fast optimization speed and high precision, but it requires high initial values such that improper initial values can easily lead to local optimization. In this paper, the performance of ten commonly used intelligent optimization algorithms is compared based on the mathematical model of the permanent magnet. The final position of the magnet is obtained by a fusion algorithm that uses the result of the intelligent optimization algorithm as the initial value of L-M. The real-time localization accuracy of this fusion algorithm is verified on a hardware platform and experiments demonstrate that the integration of the TSA algorithm and L-M algorithm fusion yields higher performance of the magnetic positioning system.

일반계 고등학생의 학습자중심수업과 학업성취도의 관계

In order to analyze the longitudinal effect of learner-centered classes of general high school students on academic achievement through school happiness, this study conducted a univariate and multivariate latent growth model analysis using data of 1,833 general high school students in the 4th and 6th years of the BELS. First, looking at the development trajectory of each research variable, it was confirmed that the average and rate of change of all variables were statistically significant, and there was a difference between individuals in changes according to grades, and students with high initial values were likely to have a relatively high rate of change. However, as the grade went up, learner-centered classes and school happiness decreased, but there was a difference in academic achievement. Next, as a result of verifying the influence of each path of the multivariate latent growth model, statistically significant influence of all paths was confirmed, but there was a difference in static and negative influence. Finally, as a result of analyzing the longitudinal mediating effect of school happiness in the relationship between learner-centered class and academic achievement, statistically significant partial mediating effect was verified in each path of initial value and rate of change. In particular, the initial value of learner-centered classes was found to have a statistically significant negative effect on the initial value of academic achievement, but statistically significant static mediating paths were analyzed when school happiness was used as a parameter.

Design, synthesis, and preliminary evaluation of [18F]-aryl flurosulfates PET radiotracers via SuFEx methods for β-amyloid plaques in Alzheimer’s disease

[18F]BAY-94-9172, [18F]AV-45, and [18F]GE-067 were FDA approved positron emission tomography (PET) imaging radiotracer of β-amyloid plaques (Aβ) in Alzheimer’s disease (AD). However, the radiochemical synthesis requires multi-step reactions and complex procedure. Recently, a protocol for radiochemical synthesis of sulfur fluoride exchange (SuFEx) using ultrafast 19F/18F isotopic exchange had been reported. We developed three pairs of novel 18F-labeled radiotracers by the “SuFEx” method for PET imaging Aβ plaques. The 18F labeling reaction can be completed quickly (30 s) at room temperature and purified using solid-phase extraction (SPE). The radiochemical purity (RCP) of the products was all greater than 95 %. In vitro fluorescent staining using Aβ-transgenesis mice section preliminary verified the affinity of tracers with Aβ. Competitive binding assay displayed high affinity of tracers for towards artificial Aβ1-42 aggregates (Ki values ranging from 3.53 ± 0.39 to 42.0 ± 4.24 nM). In vivo biodistribution and Micro-PET imaging showed that [18F]-Sulfur Fluoride β-Amyloid ([18F]SFA 1–6) could penetration the blood–brain barrier (BBB) in wild-type mice, and [18F]SFA 5–6 had a high initial brain uptake value (3.65 ± 0.9 % and 5.07 ± 0.1 % ID/g, respectively) and a fast washout (Brain uptake2 min/60 min = 4.15 and 4.61, respectively) from the brain. In vitro autoradiography demonstrated the affinity of the [18F]SFA 5–6 to Aβ plaques in AD human brain tissues. Our results suggested that [18F]SFA maybe a potential PET radiotracers for detecting Aβ in Alzheimer’s disease.

Corrosion of aluminium in ordinary Portland cement paste: Influence of matrix porosity and the presence of LiNO3 corrosion inhibitor

AbstractThe Belgian reactor 1 fuel cladding is made of aluminium. If disposed of in a geological disposal repository, aluminium could come into contact with ordinary Portland cement and is going to corrode to form hydrogen gas and aluminium hydroxide. In this study, the long‐term corrosion was evaluated by electrochemical impedance spectroscopy on metal embedded in cement paste immersed in saturated calcium hydroxide solution under anaerobic conditions. Mass transfer effects were investigated by embedding aluminium in cement paste with two different porosities. LiNO3 was also added to the systems to study its corrosion inhibiting effect. After high initial values, the corrosion rate rapidly declined to reach a steady state after a few days. After ~100 days, the corrosion rate was the lowest when cement paste possessing a low porosity with the addition of LiNO3 was used and the highest when cement paste with high porosity without LiNO3 was used. Finally, scanning electron microscopy–energy X‐ray dispersive spectroscopy revealed that the corrosion product layer was thicker than expected by electrochemical impedance spectroscopy measurements, while it is only composed of aluminium and oxygen. Aluminium was found to diffuse into the cement paste close to this corrosion product layer.

Impact of the Price of Dialysis Treatment and the Prevalence in Dialysis on the Health Budget in Portugal

In Portugal, all expenses related to the replacement treatment of renal function in chronic kidney disease are supported through the budget of the Ministry of Health. The author, who limits the analysis to the modality of dialysis treatment, reviews the relative importance of the two factors that have the greatest influence on these expenses. The so-called comprehensive price (CP) which includes dialysis, medicines and diagnostic tests – and the number of patients undergoing treatment (prevalence). The CP with a very high initial value was progressively reduced, with these corrections contributing positively to a decrease in expenses. On the contrary, the prevalence of dialysis has always been increasing, mainly as a result of an extremely high incidence of new patients starting dialysis. The positive effect of decreasing CP it is not only completely nullified by the opposite effect resulting from the increase in prevalence, but it is even surpassed, with a significant increase in expenses. Everything seems to indicate that the high prevalence of dialysis represents the most important factor responsible for the high level of state expenditure in the treatment of chronic kidney disease in Portugal. In order to contain expenses, it will be necessary not only to correct the CP value again, but to analyze the cause, or causes, responsible for the very high levels of incidence/prevalence in dialysis that are observed in our country.

GROUND OF CONSTRUCTIVE PARAMETERS OF ANTI-VIBRATION PRESS NOZZLE

The use of spent grains as an additional component of diets in animal nutrition in modern conditions is a very important issue. As a result of its seasonal formation in large quantities, there is a need for additional processing to extend the shelf life. Regardless of the direction of its further processing (canning, drying) or transportation to a farm located at a considerable distance, it is effective to partially dehydrate raw materials and reduce the initial humidity. One of the most common methods of reducing humidity at its high initial values is squeezing by pressing with screw presses. The design parameters of the anti-vibration squeezing nozzle of the two-screw press are offered and substantiated to ensure the stability of the dehydration process of pellets and reduce energy costs by achieving the stability of the pressing process. The design of an experimental sample of a two-screw press for dehydration of spent grains using a squeezing nozzle with a theoretically sound surface shape is presented. A mathematical model of the process of interaction of the surface of the squeezing nozzle with the raw material, which linked the pressure distribution in the contact zone of the medium and the surface of the squeezing nozzle with its design parameters. The geometry of the surface of the squeezing nozzle in the form of an exponential function with a power factor is established. The density of distribution of filter openings on length depending on necessary production productivity is offered. The pressure distribution along the length of the two-screw press nozzle has been experimentally confirmed. Dynamic dependences of pressure change with time are obtained, which show the stability of the pressing process and the reduction of vibration in the process at different speeds of the screws and the width of the outlet. The optimal parameters of the two-screw press for dehydration of spent grains are proposed.

Physicochemical and hygroscopic properties of charcoals produced from residues of two tropical woods from Cameroon

ABSTRACT The aim of this study was to determine the physicochemical and hygroscopic properties of charcoals from Doussie (Afzelia africana) and Okan (Cylicodiscuis gabunensis), produced from residues of two tropical woods from Cameroon. The properties determined for these charcoals included physical (moisture content, basic density, high heating value) chemical (proximate analysis, ultimate analysis, FT-IR analysis), and hygroscopic (absorption and sorption) properties. Our results show that these properties differ between the two woods. Higher values were obtained with Okan, except for the fixed carbon content. A higher diffusion coefficient on water uptake was also observed with charcoal from Okan (3.25 × 10−8 ± 0.22 m2/s) compared to charcoal from Doussie (2.42 × 10−8 ± 0.21 m2/s). The highest equilibrium moisture contents in sorption are obtained with charcoal from Okan. Our results also reveal a relationship between hygroscopic behavior and charcoals properties. It was found theoretically that an increase of initial moisture content of charcoals about 19% caused a decrease in their initial fixed carbon content about 2% and in their initial high heating value about 2.5%. The charcoals studied are of good quality and meet the recommended standards for domestic use even in humid areas.

Antimicrobial Activity of the Serum before and after Vaccination with EpiVacCorona.

We evaluated the effect of vaccination with anti-COVID-19 vaccine EpiVacCorona on serum antimicrobial activity, formation of specific IgG antibodies, and expression of some antimicrobial peptides. Antimicrobial activity of the serum from 55 volunteers towards S. aureus cells was measured spectrophotometrically; IgG-antibodies against SARS-CoV-2 antigen were assayed by ELISA; expression of genes encoding antimicrobial peptides LL37, HBD1, and HBD2 was evaluated by PCR with reverse transcription. Total antimicrobial serum activity and activity of its low-molecular-weight fraction containing antimicrobial peptides demonstrated an inverse correlation. Both activities after vaccination increased in case of low initial values, but decreased in case of high initial values. The vector of change of specific IgG antibodies to coronavirus inversely correlated with the vector of change of activity of antimicrobial peptide fraction. The expression of genes of antimicrobial peptides LL37, HBD1, and HBD2 looked like normal distribution depending on activities of the antimicrobial peptides in the corresponding sera.

Study on Strength Parameters on Fibers Using M30 Concrete

Abstract: This project work is associate degree experimental investigation on the influence of polyester and glass fibers on mechanical properties of the concrete employed in Construction. during this study 2 varieties of concrete mixes were ready one by one. polyester of 1% to 4% and Glass fiber of 1% to 3% by weight of cement were further to the mixes. A comparative analysis has been allotted for typical concrete with regard to the fiber strengthened in regard to their Compressive, Spilt tensile and Flexural Strength properties. because the Fiber content will increase Compressive, spilt tensile and Flexural Strengths area unit proportionately increasing. it's discovered that fibers multiplied on the far side 3% polyester and 2% glass fiber content leads to decrease in strengths. Economic analysis is indicating that with the addition of polyester and glass fibers will increase in economy results in higher initial value by eight to Martinmas is balanced by the reduction in maintenance and rehabilitation operations by using Fiber concrete as compared thereto of typical Concrete.

Chemical Looping Combustion of Petcoke Using Two Natural Ores in a 10 kWth Continuous Pilot Plant: A Performance Comparison

Chemical looping combustion (CLC) technology has emerged as one of the most important clean fossil fuel combustion technologies, because it allows for sequestration of CO2 with a minimal increase in energy requirements and fuel demand in comparison to traditional plants. In the framework of the Chinese–European Emission-Reducing Solutions project, the core technology of the CLC process is being developed in a 3 MWth system prototype for demonstration in an operational environment using petcoke as fuel. One of the main objectives is the selection of the oxygen carrier because it will impact the design and sizing of the demonstration unit as well as the nominal power of the unit. Two minerals, ilmenite T1 and LY Mn ore, with high potential for a well-performing oxygen carrier were tested in a 10 kWth continuous pilot unit. The collected fines were analyzed by scanning electron microscopy and X-ray fluorescence analysis to characterize the compositional and morphological evolution of the particles during operation. The performance of both oxygen carriers was compared with respect to solid fuel conversion, capacity for oxygen transfer, and particle lifetime in continuous circulation. A higher methane conversion can be obtained using ilmenite, while LY Mn is better at converting petcoke. Where the reduction potential of oxygen carriers is concerned, it was observed that LY Mn ore has a high initial R0ΔX value (R0ΔX = 0.8), which leads to a shorter activation period in comparison to ilmenite T1, which requires a longer activation period to reach its full potential. LY Mn ore is however more sensitive to attrition than ilmenite, under similar operating conditions, which is a critical characteristic for large-scale deployment. Finally, key operating parameters were identified for large-scale unit operation, including fuel reactor temperature, oxygen carrier flow rate, and fuel flow rate.

Dynamic analysis and application in medical digital image watermarking of a new multi-scroll neural network with quartic nonlinear memristor.

Memristor is widely used in various neural bionic models because of its excellent characteristics in biological neural activity simulation. In this paper, a piecewise nonlinear function is used to transform the quartic memristor, which is introduced into the ternary Hopfield neural network (HNN) with self-feedback, and a piecewise quartic memristive chaotic neural network model with multi-scroll is constructed. Through simulation analysis, the number of scroll layers changes with memristor parameters and has significant coexistence of multi-scroll attractors and high initial value sensitivity has been found. Using its excellent unpredictability, a digital watermarking algorithm based on wavelet transform is improved and used in the protection of personal medical data. The results show that it not only improves the confidentiality and convenience, but also ensures its robustness and has good encryption effect.

Testing a new combined (U,Th)–He and U/Th dating approach on Plio-Pleistocene calcite speleothems

The geochronology of cave deposits in the Cradle of Humankind UNESCO World Heritage Site in South Africa provides a timeframe essential for the interpretation of its fossils. The uranium-lead (U–Pb) and uranium-thorium disequilibrium (U/Th) dating of speleothems, mostly flowstones that underlie and blanket the fossil-bearing sediments, have been effective in this sense, but U–Pb is limited by the requirement of ∼1 ppm U concentrations and low common Pb contents, and U/Th has a c. 500 ka limit of applicability. Here we report age results for calcite-aragonite speleothems obtained using a new combined uranium-thorium-helium ((U,Th)–He) and U/Th dating routine. We reproduced within analytical uncertainty, the published U–Pb or U/Th ages for (a) flowstone in three drill core samples in the range 2000–3000 ka, (b) a flowstone hand sample taken at surface with an age of 1800 ka, and (c) five underground flowstone samples in the range 100–800 ka. Calcite retentivity for He under cave conditions is thus demonstrated. In the few cases where helium loss was observed in speleothems, only some of the subsamples were affected, and to varying degrees, suggesting loss by lattice damage not related to diagenetic processes, rather than volume diffusion. In the 100 to 800 ka range, the combined U/Th disequilibrium and (U,Th)–He method also yielded reliable values for initial (230Th/238U) and (234U/238U) activity ratios. Importantly, most subsamples had high initial (230Th/238U) values, ranging from 1.0 to 19.7, although having low Th/U ratios. This is probably due to incorporation of Fe–Mn oxides-hydroxides dust, on which 230Th was previously adsorbed. Such samples are mostly not dateable by U/Th without the additional input from the He analysis. If not detected and corrected for, such high initial (230Th/238U) values can lead to inaccurate U/Th and U–Pb ages. Our study shows that the incorporation of He analysis in U/Th dating has broad potential application, with four methods for calculating the ages, in carbonates from different environments where U-Pb or U/Th dating would not work.

Study on dynamic interfacial tension behaviors in surfactant selection for improving oil production

The selection of appropriate surfactants for improving oil production in chemical flooding relies considerably on the values of the interfacial tension (IFT) between surfactant solution and crude oil. This paper presents a study on the impact of the dynamic IFT on emulsifying capacity and oil production improvement. The dynamic IFT behaviors of anionic, nonionic, cationic and zwitterionic surfactants were measured against a light crude oil using a spinning drop tensiometer, and classified into two categories. A pair of surfactants with a similar equilibrium IFT value but different initial values were selected for comparative studies. The emulsification results suggest that the instantaneous emulsification, a key mechanism for oil mobilization, is mainly attributed to a quick initial IFT reduction, affecting oil productions. The results of micromodel tests using surfactants and coreflooding oil displacement experiments using surfactant-polymer mixtures indicate that the system has low initial IFT value achieves significantly higher incremental oil production than the system that has high initial IFT value. This suggests the surfactants that are able to reach quick initial IFT reduction are preferential for improving oil production applications.

Study of wear performance of wheel and rail steels under dry sliding conditions

The demand for efficient railway services has significantly increased in the past years due to an increased demand for the high-speed transportation of goods with high loads. The increase in loads and velocities has resulted in increased problems associated with rolling contact fatigue (RCF), rolling and sliding wear on the wheel and rail materials causing a reduction of service life of wheel/rail systems. Rail operating companies spend significant funds in maintenance and replacing damaged rails and wheels caused by wear. In addition, unscheduled maintenance due to wear and RCF often lead to poor availability of railway networks. For this study, dry sliding wear was investigated on wheel and rail steels using RTEC Multi-Function Tribometer. The results demonstrated that the rig was successful in simulating sliding wear, and that the fractions of the wear components could be varied, and it also provided instrumentation. Information on coefficient of friction against sliding distance and applied force were obtained which were used to compare sliding wear performance of both wheel and rail steels. The wheel was found to perform better than the rail under the same conditions due to its high initial hardness values and smaller interlamellar spacing.

A Cohort Study to Decode the Application of Peritoneal Carcinomatosis Index in Predicting the Prognosis of Advanced Ovarian Malignancies

Introduction: Peritoneal Carcinomatosis Index (PCI) is used to assess the extent of peritoneal cancer by dividing the peritoneal cavity into 13 well-defined regions and assessing the size of the largest tumour nodule in each region. Aim: To evaluate the imaging features of peritoneal carcinomatosis using Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) and correlate it with diagnostic laparotomy. Also to To determine the prognostic significance of peritoneal carcinomatosis index calculated radiologically in predicting the outcome of advanced ovarian malignancies. Materials and Methods: This was a prospective cohort study conducted in Kilpauk Medical College, Chennai, Tamil Nadu, India, from July 2019 to December 2020. Total of 50 females between 18-80 years of age with advanced ovarian malignancies with peritoneal deposits underwent CT and MRI to calculate initial PCI. Then these patients underwent cytoreductive debulking after which final response was assessed. Followedup for a period of 1 year to assess the treatment response and to look for any complications. IBM Statistical Package for the Social Sciences (SPSS) version 22.0 software was used for statistical analysis. Descriptive analysis was carried out using mean and standard deviation for quantitative variables. Results: Fifty women were included with a mean age of 53.4 years. PCI calculated using CT and MRI showed strong correlation with laparoscopic PCI with correlation coefficient (r) of 0.984 and 0.988 respectively with a statistically significant p-value &lt;0.001. Initial radiological PCI and cytoreduction showed strong correlation when analysed using ROC curve (Receiver Operating Characteristic curve) with an AUC (Area under the ROC Curve) of 0.933. With Youden index a cut-off value of 11 was derived under which patients had optimal cytoreduction and a better outcome. Radiological PCI showed good sensitivity (82.35%) and specificity (88.78) for predicting complications and it was found that patients with PCI &gt;15 were at a higher risk for developing various complications. Conclusion: Radiological PCI strongly correlate with laparoscopic PCI and is a very strong predictor of disease outcome in advanced ovarian malignancies. It was found that patients with high PCI values had poor response to cytoreductive surgery and chemotherapy. So, high initial PCI values above 11 was indicative of poor patient prognosis.