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Background: N-methyl-D-aspartate (NMDA) receptors are thought to be for pain memory, and blocking them can help to reduce pain. We aimed to assess the preventive effects of small doses of ketamine ...

Objectives: The electrophysiological characteristics of attention-deficit/hyperactivity disorder (ADHD) and recent machine-learning methods promise easy-to-use approaches that can complement existing diagnostic tools when sufficiently large samples are used. Neuroalgorithms are models of multidimensional brain networks by means of which ADHD patient data can be separated from healthy control data. Methods: Spontaneous electroencephalographic and event-related potential (ERP) data were collected three times over the course of 2 years from a multicentre sample of adults comprising 181 patients with ADHD and 147 healthy controls. Spectral power and ERP amplitude and latency measures were used as input data for a semi-automatic machine-learning framework. Results: ADHD patients and healthy controls could be classified with a sensitivity ranging from 75% to 83% and specificity values of 71% to 77%. In the analysis of the repeated measurements, sensitivity values of the selected logistic regression model remained high (72% and 76%), while specificity values slightly decreased over time (64% and 67%). Conclusions: Implementation of the system in clinical practice requires facilities to track affected networks, as well as expertise in neuropathophysiology. Therefore, the use of neuroalgorithms can enhance the diagnostic process by making it less subjective and more reliable and linking it to the underlying pathology.

Introduction: Cytokeratin fragment 21.1 (CYFRA 21.1) assay detects a serum fragment of cytokeratin 19 (CK19) and is employed in the diagnosis and management of lung cancer, particularly of squamous cell histotype. Breast carcinoma has been demonstrated to express CK19 fragments in the primary and metastatic lesions and CK19 mRNA is detectable in peripheral blood from patients affected by breast cancer. Aim of the work: The aim of the present study was to evaluate the clinical significance of serum CYFRA21-1 in patients with breast cancer by analyzing the correlation between serum CYFRA21-1 titers, clinicopathological factors and prognosis in comparison with serum CA15.3 and CEA tested in the same samples. Subjects and methods: This study included 60 breast cancer patients and 25 healthy females as control group. Three blood samples were drawn from each patient, before surgery, two weeks after surgery and after 6 cycles of chemotherapy. One blood sample was drawn from each subject of control group. Serum was separated and kept frozen till used for estimation of CYFRA21-1 by enzyme linked immunosorbent assay (ELISA) and serum CA15.3 and CEA by immunoradiometric assay (IRMA). Results: Serum CYFRA21-1 was highly elevated in breast cancer patients than in controls and was significantly associated with tumor size, clinical stage and axillary lymph node involvement. Serum CYFRA21-1 was superior to CA15.3 and CEA as a diagnostic marker for breast cancer using ROC curve analysis. Higher levels of serum CYFRA21-1 and CA15.3 were significantly associated with poor prognosis in primary breast cancer patients. Conclusions: The measurement of serum CYFRA 21-1 in breast cancer patients may be useful for detecting disease relapse and for assessing surgical and chemotherapeutic efficacy. Further prospective studies using greater number of patients are required to confirm our findings.

Steady laminar two-dimensional incompressible flow over in-line flat-tube bundles used in heat exchanger applications is considered in this work. The effect of Reynolds number (Re = 50, 100, 200, and 400) and (height/length) aspect ratio , , , and on the pressure drop and heat transfer were studied. A finite-volume-based FORTRAN code was developed to solve the governing equations. A computational fluid dynamic (Flunet 6.2.16) is used to predict the heat transfer and fluid flow over in-line flat-tube bank. A small change in the heat transfer rate can be predicted since the fluid has almost the same behavior when the (height/length) ratio is increased. The (height/length) ratio was found to have very little effect on pressure. The comparison is made between the present computational fluid dynamic results and Bahaidarah (2004) for normalized pressure difference versus Re number, across a single in-line configuration module. A reasonable agreement is observed. Also, the comparison between the present predicti...

A computation procedure (CFD-Fluent 6.2) for two-dimensional fluid flow is applied to predict the pressure drop and heat transfer characteristics of laminar and turbulent flow over staggered flat-tube bank. Effect of aspect ratio on pressure drop, temperature, and velocity contour for laminar and turbulent flow over staggered flat-tube bank is studied. The theoretical results of the present models are compared with previously published experimental data of different authors. Satisfactory agreement is demonstrated. Also, the comparison between the present study and others’ analytical methods for the Re number with Nu number is done. The results show that the Reynolds number increases the maximum velocity in the passage between the upper and lower tubes’ increases. The comparisons show a fair agreement, especially in the turbulent flow region. The good agreement of the data of this work with these recommended analytical methods validates the current study.

A numerical study of heat transfer and turbulent fluid flow over a staggered circular tube bank using a computational fluid dynamic code (Fluent 6.2) is presented in this work. The model for staggered arrangements is applicable for use over a wide range of the aspect ratio when determining heat transfer and turbulent fluid flow over a staggered circular tube bank. The turbulence model used involves the solution of two partial differential equations, one for the kinetic energy of the turbulence and the other for its dissipation rate. The results show that the average heat transfer for tube banks in cross flow depend on aspect ratio , Reynolds number, and Prandtl number. The present model gives higher heat transfer rates for all cases of Re number. The higher values of pressure drop distribution usually recorded near the initial of the external tube bank surface in all cases. The maximum velocity in the passage between the upper and lower side was recorded. The present results of the average Nusselt numbers...

A numerical study of heat transfer and fluid flow past single tube using computational fluid dynamic (FLUENT 6.0) to predict the heat transfer and pressure drop characteristics of turbulent flow past single tube is presented in this work. The results show that the pressure drop decreases as the aspect ratio increases. The fluid is heated in the near wall and wake regions and the predicted temperatures serve as excellent benchmark data for assessing computational fluid dynamic predictive accuracy for the selected cases. The maximum velocity increases as the aspect ratio increases. The overall performance of single tube with a lower aspect ratio is preferable since it provides a higher heat transfer rate. Higher turbulence kinetic energy is at the inlet and outlet computation domain of the lowest aspect ratio, and near the upper side and the first upper corner of the external surface of the tube with the case L/D = 2.0.

Heat transfer and fluid flow over an in-line tube bank using computational fluid dynamic prediction is presented in this study. The study considers steady laminar two-dimensional incompressible flow over in-line tube bundles used in heat exchanger applications. The effect of various independent parameters, such as Reynolds number (Re), length aspect ratio (L/D = 2.5, 2, 1.5, 1.0, 0.5, and 0.0), and fluid flow on the pressure drop and heat transfer, is studied. A computer code (CFD-Fluent) is generally used to predict the heat transfer and pressure drop characteristics of flows around or through rigid complex geometry, namely, domains whose boundaries do not coincide with coordinate lines of a Cartesian or any simple coordinate system. A comparison is made between the present computational fluid dynamic predictions and reference measurements [Iwaki, C., Cheong, K. H., Monji, H., and Matsui, G. 2004. PIV measurement of vertical cross flow structure over tube bundles. Experiments in Fluids 37:350–36...

A new system to produce cooling and power with the energy obtained from low-temperature as a thermal resource is presented in this work. This resource can be obtained from concentrating solar thermal energy (parabolic trough). This system belongs to the broader class of low temperature, Rankine cycles, which have been shown to be one of the most effective means for utilizing low temperature resources. They have been applied to the production of mechanical power using heat from solar. The system uses thermal energy in a low-temperature boiler to partially boil working fluid mixture (ammonia-water). The theoretical study is presented, which identifies expander inlet conditions, expander efficiency, and exhaust pressure as the factors determining exhaust temperature. It is concluded that the proposed system improves the expander performance, output power, and cooling production and can be satisfied with this concept.

A novel hyperbranched poly (ester-amine) was synthesized, characterized, and used in finishing formulations for attaining functionalized cross-linked cellulose structure. The data show that: (i) incorporation of the prepared HBP in the finishing bath results in an increase in nitrogen content, flexural rigidity and dyeability with anionic dyes along with a decrease in fabric resiliency; (ii) post-treatment with iodine solution brings about a remarkable improvement in antimicrobial properties; and, (iii) subsequent treatment of modified-cross-linked cotton fabrics with Zn- or Cu- acetate leads to a higher UV-protecting and antibacterial functionalities along with a high durability to wash.

This work was motivated by the increasing awareness of the need for enhancing water supplies schemes in arid and coastal areas featuring an appropriate technology for wind energy use. The development of this technology at small scale might be the most economical solution for providing potable water to remote and coastal communities where the electric grid and the proper infrastructure are lacking. The present article analyzes theoretically a wind turbine generator to improve the efficiency of an autonomous desalination unit. Three climatic zones in coastal Egypt—Mediterranean Sea coast and the Red Sea coast have been evaluated and the acoustic noise analysis and calculation from the proposed wind turbine are presented. The mechanical coupling of wind turbine and helical shaft to break the boundary layer of the basin water surface and, therefore, to enhance the performance of the solar desalination system is studied. The analytical assessment reveals that the Egyptian coastal areas are ideally sui...

Three different hyperbranched polymers (H1, H2, and H3) were prepared. The H1 and H2 are hyperbranched polyesteramide polymers; however, H3 is a poly(urea-urethane) hyperbranched polymer. The three polymers were treated with Br-ended surfactant units, which were prepared via simple reaction of Tergitol Np-50 (S) as surfactant with bromoisobutyrylbromide. New ended polymers resulted as H1S, H2S, and H3S with new ethyleneoxide units. Critical micelle concentration (CMC) was studied for the newly prepared polymers (H1S, H2S, H3S) and was compared with the original ones (H1, H2, H3) on the way to involve the new modified polymers in various industrial applications. The CMC was determined by the surface tension technique employing the platinum ring method. It was found that CMC could be arranged in the following ascending order: H3S

In this work, the heat transfer and fluid flow analyses are employed to optimize the geometry of the pin-fin heat sinks. An entropy generation minimization method is employed to optimize the overall thermal performance and behavior of pin-fin heat sinks. The performance of the heat sinks is determined by its thermal resistance and pressure drop, since they significantly influence the thermal resistance during forced convection cooling. The optimum design of heat sink for in-line and staggered alignments with circular, square, rhombus, rectangular, and elliptical configurations are investigated, and the thermal behavior is compared. The entropy generation rate is developed using mass, energy, and entropy balance over the control volume. The formulation for the dimensionless entropy generation rate due to heat transfer and due to fluid flow (pressure drop) is obtained in terms of fin geometry, thermal conductivity, pin-fin alignment, Reynolds, and Prandtl numbers. Using an energy balance equation o...

The aim of the present investigation was to develop a simple and fast method for the determination of cyclophosphamide in human plasma samples. Microextraction in packed syringe (MEPS) was used as an online rapid sample preparation method, followed by liquid chromatography with tandem mass spectrometry (LC‐MS‐MS) for the quantification of cyclophosphamide. The new method reduced the sample handling and the analysis time by several folds compared to liquid chromatography and UV detection. The limit of detection (LOD) was 0.005 µg/mL and the lower limit of quantification was 0.5 µg/mL. The accuracy of the quality control (QC) samples ranged from 95 to 106%. The inter‐day variation was within the range 5–9% while the intra day variation was between 1–5%. The calibration curve in plasma was constructed within the concentration range 0.5–150 µg/mL. The regression correlation coefficient (r) was ≥0.99 for all runs. The limit of detection improved by 100 time using MEPS‐LC‐MS/MS (0.005 µg/mL) compared t...

A theoretical study of the thermal behavior of salt-gradient solar pond located in Cairo (latitude angle 30°05′N and longitude angle 31°17′E) is presented in this work. The present model is chosen for thermal analysis of six salt-gradient layers of the solar pond. One-dimensional time-dependent solar energy absorbed in six layers of the solar pond of the present solar pond is applied using Fresnel's equations. The vertical temperature variation through six layers during the days of the month year round is presented. The daily temperature fluctuations are smallest for larger depths and about 12°C for the 137.5 cm. The theoretical form of the absorption of solar radiation by salt gradient of water layers is presented. The solar radiation transmission through the layers of the present pond is illustrated. The amount of energy absorbed by the layers of the salt gradient is predicted during the days of the month around the year. The mean amount of absorption energy in the layer (1) is 55,196.1 cal/cm2...

Busulphan is an alkylating agent used in high doses as preparative regimen before stem cell transplantation (SCT). Busulphan has a narrow therapeutic window and under‐ or overdosing may have a fatal outcome for the patient. Therapeutic drug monitoring followed by dose adjustment is currently used to adjust the exposure to busulphan. This is an important issue to optimise and individualise high dose therapy with busulphan. However, this approach is limited to centres with experienced personal measuring busulphan plasma concentrations. An automated and easy‐to‐handle method for measurement of busulphan plasma concentrations may facilitate and wide‐spread drug monitoring approach and thus improve the outcome of the patients undergoing SCT. Microextraction in packed syringe (MEPS) in combination with liquid chromatography and electrospray ionization mass spectrometric detection (LC‐MS/LC‐MS‐MS) to quantify busulphan in human plasma samples without derivatization was developed. MEPS is a new miniaturi...

Thermal analysis of heat transfer through different storing media using oil as working fluid is presented. The storing medium is solid material in spherical shape. Steel, glass, and pebbles are selected as storing media and oil is selected as working fluid. The physical model is a heat exchanger in cylindrical shape, which is packed with each of the selected storing medium. The heat transfer through the heat exchanger is assumed to be one dimensional along its height. The flow of the working fluid is an axial direction from the top to downward. The problem is governed by two partial differential equations for the working fluid (oil) and the storing medium. Finite difference method and Thomas algorithm solver are used to solve the couple of the two partial differential equations along with their associated initial and boundary conditions. The modified computer program is used to obtain the solution of transient temperature distribution of the storing medium and the working fluid. The amount of abs...

The aim of the present investigation was to develop a simple, fast, and sensitive method for the determination of acebutolol and metoprolol in human plasma and urine samples. The determination of a ...

Quantification of 4-OH-2,6-Xylidine and its Conjugates in Human Urine Samples Utilising Microextraction in Packed Syringe On-line with Liquid Chromatography and Electrospray Tandem Mass Spectrometry (MEPS-LC-MS/MS)

The excellent performance of a new sample preparation method, microextraction in packed syringe (MEPS), was recently illustrated by online LC‐MS and GS‐MS assays of local anaesthetics in plasma sam ...

Micro extraction in packed syringe (MEPS) has been evaluated for drug and metabolites screening online with mass spectrometric detection. In this study, silica based (C8), polymer based (ENV+), and a methacrylate based organic monolith were used as sorbents for MEPS. Monolithic material has shown to be an effective chromatographic support for the separation of several classes of compounds. In this study, the focus is subdivided into three parts: 1) Using MEPS for drugs and metabolites screening, 2) Preparation of a monolithic material in situ in a syringe, and 3) Comparison of the monolith, ENV+, and C8 as sorbent material. The synthesis of the monolithic material was by radical polymerization of glycidyl methacrylate (GMA), ethylene glycol dimethacrylate (EGDMA), and butyl methacrylate (BMA) in porogenic solvent 1‐dodecanol and cyclohexanol. An 8 µL of the synthesized material was drawn into a 250 µL syringe and thermally polymerized at 57°C for 24 h. Individual syringes containing the monolithi...

Alloy materials are suggested as storing media to realize the optimum performance of the thermal energy storage system. The storage capacity and thermal energy stored inside the suggested storing media are obtained through a transient one-dimensional mathematical model for the present system. The finite difference method and Thomas algorithm solver are used to solve the present model. A cylindrical tank is filled with the suggested storing media to form beds as heat absorbers. The bed is thermally charged with hot air flowing axially through the storing media, then the heat exchange occurs between the hot air and the storing media. The suggested alloy materials (M al ) are alumgsi, duralumin, brass, al-bronze, wrought iron, carbon steel and cast iron, as metallic-alloys. Solutions are obtained for the storing media properties (ρ, C p and K). Energy stored comparison is done between the suggested storing media, rock and porcelain. The results show that increasing either the density, ρ, or specific heat, C ...

Alanine/EPR rods (3 × 10 mm) for routine use in high-dose radiation applications have been prepared by a simple technique in the laboratory where alanine powder was mixed with molten mixture of paraffin wax and ethylene vinyl acetate copolymer (EVA). The binding mixture EVA/Paraffin does not present interference or noise in the EPR signal before or after the irradiation. The rods show good mechanical properties for safe and multi-use handling. The rods can be used with good precision in the dose range from 1 to 125 kGy. The overall uncertainty for calibration of the EVAPA rod dosimeters at 2σ was found to be 4.56%. The dose response, influence of humidity and temperature during irradiation, energy dependence as well as post–irradiation storage at different conditions are discussed.

Electrochemical oxidative polymerization of 2-amino-4-phenylthiazole on platinum electrode in acid medium was carried out. Different reaction parameters were investigated such as current density, acid concentration, monomer concentration, and temperature with duration of time. The orders of the electropolymerization reaction were found to be 1.06, 1.10, 1.16 with respect to current density, acid concentration, and monomer concentration, respectively. The apparent activation energy (Ea) was found to be 61.04 kJ mol−1. The obtained polymer films were characterized by IR, UV, 1H-NMR, elemental analysis, thermogravimetric analysis, and cyclic voltammetry. The mechanism of the electrochemical polymerization reaction has been also discussed. Surface morphology of the obtained polymer film was characterized by X-ray diffraction and scanning electron microscopy.

New modified alkyd varnishes were prepared by partial replacement of phthalic anhydride with methylene disalicylic acid. Incorporation of this phenolic derivative led to significant improvement in hardness, gloss, and alkali resistance performance.

Sustained-release (SR) theophylline (TPH) tablets were prepared by applying the moisture-activated dry granulation method. The interaction between the excipients sodium alginate (SAL) and calcium gluconate (CG) was the base for the formation of a cross-linked matrix that may regulate TPH release from the formulated tablets. The prepared granules showed good physical characteristics concerning the flow properties and compressibility, with the angles of repose in the range 29-31, and the compressibility indices ranged between 15% and 25%. The granules had low friability values (3.0%-4.2%), depending on SAL:CG ratios. The corresponding tablets showed good physical properties, with a lower rate of drug release compared with the commercial TPH tablets (Quibron). The release of TPH from the prepared tablets was not markedly affected by either the concentration of added dry binder (carbopol 934) or the tablet hardness, indicating that the rate-determining step in drug release was the diffusion through the produced calcium alginate matrix. Tablets formulated with equal ratios of CG and SAL that showed good physical properties and slow TPH release were chosen for bioavailability studies in beagle dogs, and results were compared with those for Quibron. The in vivo data showed a comparable plasma concentration profile for both tablet formulations, with prolonged appearance of drug in the plasma in detectable amounts for up to 24 h. The formulated tablets showed 104.65% bioavailability relative to that of the commercial tablets. The rate and extent of absorption of TPH showed no significant differences from that of the commercial tablets. Moreover, no significant differences were found in the pharmacokinetic parameters related to the rate and extent of TPH absorption from the prepared and commercial tablets.

The present study includes two main parts. The first describes hydrogen production from electrolysis water depending on the DC output current of the photovoltaic (PV) energy source. The second part presents the utilization of produced hydrogen to generate electric power. The design of a closed loop cycle for electrolyzer and fuel cell to produce hydrogen and generate electrical energy, respectively, depending on a renewable energy source, is considered. Five different types of electrolyzer and fuel cells are studied to depict the effect of these types with respect to the current, voltage, cell temperature, cell pressure, sizing, and the required number of modules to produce one cubic meter of hydrogen per one hour. According to the various types of electrolyzer and fuel cell, multi PV systems are designed to produce 10 m3/day of hydrogen. The daily PV solar energy consumption to produce 10 m3 of hydrogen gas is calculated. Also, I-V and P-V characteristics of PV arrays for different percentages of insolat...

This work presents a new way to realize continuous operation of a solar desalination system to produce fresh water using solar energy for a dual purpose. Here, solar energy is used directly as heat energy through solar radiation incident on an inverse V-shape still cover during sunlight hours. At the same time, the solar energy can be converted through a photovoltaic (PV) array into electric energy, which is stored in the battery system during sunlight hours. To realize the continuity of still operation daily and overnight, the batteries are discharged during the night at a suitable rate to feed an electric heater. The electric heater is designed to generate the required heat for desalination during the night. The heat is equivalent to that which can be absorbed during the day and that gives the temperature difference to gain evaporation and fresh water (productivity). This modified still is provided with a packed bed layer installed in the bottom of the basin to assist the system during the day ...

Thermal analysis of energy storage in layers of various materials used as a packed bed storage system is presented. It is more economical to minimize insulation costs, to store more energy from the same input conditions, to lengthen the time of charging that the energy could be kept stored with acceptable losses, and to obtain higher storage capacity. These are the focus of this work. A cylindrical bed is formed from three layers of different materials, equal in length, as heat-absorbing media. The bed is charged with flowing hot air in the axial direction, the hot air representing the heat source. A transient one-dimensional model is used to describe the thermal behavior of the system. The partial differential equations that govern the flow and heat transfer for both the air and the solid, constituting the bed and their boundary conditions, are driven. The numerical solution of two partial differential equations is obtained using the finite difference method through a computer program especially constructed for this purpose. The temperature field for the air and the solid are obtained, and the energy stored inside the bed is computed. A wide range of layers of storage media of different materials with different thermalmore » properties is selected. Comparison is made between the present system and packed bed systems using one storing medium. The results show that the bed packed with different layers has higher storage capacity and there is step stratification of the temperature between the materials layers. Also, the bed that includes metal material (such as steel) has a maximum storage capacity, and less considerable temperature than other beds, so such a bed can realize the claimed function.« less

Because of their simplicity, ease of operation, and low cost, photovoltaic (PV) thermal systems have been constructed for commercial operation, particularly in developing countries. This work presents a new solar electric thermal energy storage system. The design is of a PV standalone with a packed bed thermal energy storage unit. The unit is intended for use as an economic storage system to supply the heating load (air space and water) with thermal energy where the gap between the main source and the load demand occurs during the night. The bed is packed with different materials that have high thermal properties. Design, savings, and operation are also discussed. The PV system is very efficient for rural areas, especially those with high insulation. The results show that the steel bed gives maximum thermal energy storage, while the pebble bed gives a minimum amount of thermal energy storage. The air mass flow rate affects the storage capacity and charging time. Also, the mathematical results of the elect...

Major problems of the arid region are transportation of agricultural products and losses due to spoilage of the products, especially in summer. This work presents the performance of a solar drying system consisting of an air heater and a dryer chamber connected to a greenhouse. The drying system is designed to dry a variety of agricultural products. The effect of air mass flow rate on the drying process is studied. Composite pebbles, which are constructed from cement and sand, are used to store energy for night operation. The pebbles are placed at the bottom of the drying chamber and are charged during the drying process itself. A separate test is done using a simulator, a packed bed storage unit, to find the thermal characteristics of the pebbles during charging and discharging modes with time. Accordingly, the packed bed is analyzed using a heat transfer model with finite difference technique described before and during the charging and discharging processes. Graphs are presented that depict the thermal...