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Many thrombotic complications are linked to coronavirus disease 2019 (COVID-19). Antithrombotic treatments are important for prophylaxis against these thrombotic events.This study was designed to compare enoxaparin and rivaroxaban as prophylactic anticoagulants in moderate cases of COVID-19 in terms of efficacy, safety, and clinical outcomes.The study involved 124 patients with moderate COVID-19 (pneumonia without hypoxia) divided into two groups. The first group (G1) comprised 66 patients who received enoxaparin subcutaneously at a dose of 0.5 mg/kg every 12 h until discharge from the hospital. The second group (G2) comprised 58 patients who received oral rivaroxaban at a dose of 10 mg once daily until discharge from the hospital. The outcomes evaluated in this study were as follows: intermediate care unit (IMCU) duration, the number of patients transferred from the IMCU to the intensive care unit (ICU), ICU duration, the total length of hospital stay, in-hospital mortality, and thrombotic and bleeding complications.No significant differences in IMCU duration (p = 0.39), ICU duration (p = 0.96), and total length of hospital stay (p = 0.73) were observed between the two groups. The percentage of patients requiring ICU admission after hospitalization was 21.2% in G1 and 22.4% in G2 (p = 0.87). The mortality rate was 12.1% in G1 and 10.3% in G2 (p = 0.76). The proportion of patients who had thrombotic complications was 9.1% in G1 and 12.1% in G2 (p = 0.59). The incidence of mild bleeding was 3% in G1 and 1.7% in G2 (p = 0.64).Either enoxaparin or rivaroxaban may be used as thromboprophylaxis agents in managing patients with moderate COVID-19. Either medication has no clear advantage over the other.

Conventional water-softening processes usually involve the exchange of Na+ ions for Ca2+ and Mg2+ using commercial or synthesized ion exchangers. The differences in chemical compositions of the ooids can be attributed to the formation in different environments. In this paper, ooid grains form inside assembled semi-pilot softening unit through a continuous chemical process involving reaction between bicarbonate ions and added lime using natural seawater. Our sample of Mediterranean seawater has low Mg2+/Ca2+ ratio (1.98%) within the range chemically favorable for precipitation of low-Mg calcite ooids. Precipitation of calcite occurs around pure quartz sand grains which act as nucleation points (the bed required for sand vessel is 1.65 l). The shape of the sand grains controls the overall external morphology of the resulting ooids; they vary in size from 0.5 to 3.0 mm and have a high degree of polish due to surface abrasion caused by continuous agitation inside the softening system. Calcite ooid grains (1.53 kg) formed within the seawater-softening unit every 18 days have many of the ooid features formed in marine environments. Ooids grow to a significant size, at a rate of about 0.17 mm of one layer thickness per day inside the softening unit. The average weight percent of calcite precipitate is 35.48% after 18 days, at 10 °C, 60 l/min and pH 9.0. The pellets comprise mainly CaCO3 and SiO2 and some metal ions which may substitute for calcium ions in calcite are present only in trace amounts of the total composition.

The kinetics of the Fe(II) uptake by Co/Mo layered double hydroxide (Co/Mo-LDH) intercalated with carbonate (CO3)2− as an interlayer anion was studied. The results revealed that the maximum adsorption capacities were 29.5, 59.1, and 77.9 mg/g when the initial ferrous ion concentration was 25 mg/l at 298, 308, and 318 K, respectively. These results displayed a high efficiency of the Fe(II) uptake from aqueous solution at higher temperature. The adsorption isotherms were seen to be consistent with Langmuir’s adsorption isotherm. The equilibrium adsorption contact time was determined for Co/Mo-LDH. This suggested that the pseudo-first-order equation might not be sufficient to depict the kinetics of Fe(II) onto the Co/Mo-LDH, and the kinetics of adsorption of Fe(II) onto Co/Mo-LDH were best described by the pseudo-second-order model. Also, the paper discussed the thermodynamic parameters of the adsorption (Gibbs free energy, entropy, and enthalpy). Our results demonstrated that the adsorption process ...

A new type of M2+/M6+-LDH was prepared by the intercalation of Co/Mo-LDH with carbonate (CO3)2− as an interlayer anion through a precise control of the titration rate of the alkaline solution into the cobalt and molybdenum cations. From the analytical results, the structure, composition and morphology of the prepared material were approved by XPS, XRD, FT-IR, N2 adsorption–desorption isotherm, SEM, and DSC-TGA. The synthesized Co/Mo-LDH was applied to the removal of ferrous ions from aqueous solutions at ambient temperature, different pH, constant stirring at 160 rpm and different iron/adsorbent ratios. According to the experimental data, we have succeeded to prepare a novel adsorbent for Fe(II) uptake and at pH 5, stirring at 160 rpm, and after 60 min the uptake reached a maximum value of 10 mg/g of Co/Mo-LDH. Hence, the higher adsorption capacity of the Co/Mo-LDH was explained by the formation of 4+ surface charges between Co2+ and Mo6+ which produced a highly energetic surface layers as detecte...

PurposeTo evaluate effect of water storage on micro-shear bond strength of adhesives to class I cavity-bottom dentin using two types of composites resin.Materials and methodsNinety teeth were divided into three groups I,II&III (thirty molars each) according to the adhesive used, either total-etch 2-step (Adper Single Bond, 3M ESPE), self-etch 2-step(Clearfil SE Bond, Kuraray), or self-etch 1-step(Futura Bond, Voco) respectively. Each group was subdivided according to type of composite restoration used, either Hybrid (Clearfil APX, Kuraray), and Packable (Filtek P60, 3M ESPE). All teeth were thermocycled for 500 cycles,and subjected to occlusal load cycling for 120.000 cycles corresponding to 6 months clinical use. Bonding effectiveness was assessed by micro-shear bond strength test (μSBS) after 1 day, 3 months, and 6 months water storage.ResultsThe mean μSBS values (±SD) for Subgroup IA(SB2-APX) were 32.58 ± 1.416, 31.820 ± 2.119, and 30.910 ± 1.393 MPa after 24 h, 3 month, and 6 month respectively; while for Subgroup I B(SB2-P60) were 31.960 ± 1.659, 31.350 ± 1.765, and 30.380 ± 1.773 MPa respectively. Subgroup II A (CSE-APX) recorded 37.28 ± 1.061, 36.77 ± 2.32, 36.21 ± 1.964 MPa, while Subgroup II B(CSE-P60) recorded 37.0 ± 2.115, 36.460 ± 1.727, and 36.080 ± 1.910 MPa after 24 h, 3 month, and 6 month respectively. Subgroup III A (FB-APX) showed 30.550 ± 2.088, 26.890 ± 1.533, and 21.590 ± 1.784 MPa, while subgroup III B (FB-P60) showed 29.790 ± 1.172, 25.960 ± 2.672, and 21.410 ± 2.126 MPa after 24 h, 3 month, and 6 month respectively.ConclusionTwo-step Total-etch and Two-step self etch adhesives showed better tolerance to water storage compared to One-step self-etch adhesive. However, the type of composite restoration had no significant effect on the microshear bond strength of dental adhesives.

Wool yarns are dyed with natural colouring matter that is extracted from cochineal, turmeric and madder, and mordanted with different mordants by using the exhaustion method. Many measurements of mordanted dyed wool samples have been carried out after exposure to air and light for different periods of time in the time frame of one year in an urban area (Helwan city). The variables that are measured include changes in colour and physical properties (tensile strength, tenacity and elongation) of mordanted dyed wool samples. Also, air pollution in Helwan city is determined by studying suspended and deposited particulate matter and sulpher dioxide concentrations.

Thermal and optical performance of solar water disinfecting systems using parabolic trough collector, PTC, have been investigated experimentally and numerically. Four PTCs systems were designed, manufactured and field tested under the same weather conditions of Cairo 30°N. The four systems were installed to be compared thermally and biologically. Each system consists of a 2-m2 PTC and line-focus pipe to carry the water sample to be disinfected. In the first system (thermal system), a black painted stainless steel pipe covered by Pyrex glass envelope, to minimize the convective and radiative heat loss, is supported through the line-focus of the PTC. While in the second system (optical system) the contaminated water is used as absorber through a Pyrex glass tube, the two above processes are considered respectively in the third system. In the fourth system, a black tube including and surrounded by the contaminated water are considered as the absorber. The contaminated water is passed through the annular spac...

The dyeing of acrylic fabrics using C.I. Astrazon Basic Golden Yellow GLE is studied with both conventional (CH) and ultrasonic (US) techniques. The factors that affect dyeability, such as dye bath pH, US power, dyeing time and temperature, are studied. The colour strength values obtained are found to be higher with US than CH heating. Also, the fastness properties of the dyed fabrics are determined with. A comparative study using x-ray and scanning electron microscope (SEM) that is implemented on samples to explain for the better dyeability of acrylic fabrics with the US method. Dyeing kinetics and the time/dye-uptake isotherms reveal enhanced dye-uptake in the second phase of dyeing. The values of the dyeing rate constant, half-time of dyeing and standard affinity, and US efficiency are calculated and discussed.

PurposeTo explore the use of power ultrasound as an environmentally friendly heating technology for the pre‐treatment of linen fibres with sodium perborate as the halogen free oxidising agent and to study the impact of this process on its dyeability with reactive dyes.Design/methodology/approachExploiting power ultrasound in the wet processes of linen fibres was made in two steps, i.e. ultrasonic pre‐treatment with sodium perborate followed by ultrasonic dyeing with reactive dyes. Therefore, comparative studies between conventional and ultrasonic techniques as well as the different factors that may affect these processes were investigated. The effect of the pre‐treatment on fibre fine structure using X‐ray diffraction technique was also investigated.FindingsThe results of the increase of whiteness index indicate that ultrasonic pre‐treatment was better at all studied treatment times and at low temperature. X‐ray diffraction studies on blank, ultrasonically and conventionally pre‐treated linen fibres have shown 70.41, 67.51 and 64.90 per cent crystallinity, respectively. The dyeing of the pre‐treated fibres with Reactive Red 24 was simultaneously carried out under both ultrasonic and conventional heating conditions to study the effect of dye concentrations at different dyeing temperatures. The colour strength values obtained for the dyed samples using ultrasonic at 50°C were slightly higher than those obtained using conventional heating at 80°C. Ultrasonic enhancement in the pre‐treatment and dyeing in terms of the percent increase of colour strength of the dyed fabric was estimated to be 157.94 per cent higher than that of conventional heating method. The results of wet fastness properties of the dyed fibres using ultrasonic revealed improvement relative to those obtained using conventional heating method.Research limitations/implicationsThe improved wet processes of linen fibres suggest further investigation to exploit power ultrasound in the wet processes of cellulosic fibres at low temperature using different classes of halogen free bleaching agents and dyeing with different classes of heat‐requiring reactive dyes. Also, this work may inspire the synthesis of new generation of heat‐requiring reactive dyes.Practical implicationsThe work presented has significant potential industrial application for cleaner production in textile industries.Originality/valueThe present study of linen pre‐treatment with non‐toxic total chlorine free oxidising agent and its dyeability with reactive dyes using power ultrasound is novel and could be used in the wet processes of linen fibres.

Thin films of cobalt–nickel alloys were galvanostatically deposited onto steel substrates from gluconate baths. Cathodic polarization curves were determined for the parent metals and Co–Ni alloy. The effects of bath composition, current density and temperature on cathodic current efficiency (CCE) and alloy composition were studied. The deposition of Co–Ni alloy is of anomalous type, in which the less noble metal (Co) is preferentially deposited. The CCE of codeposition is high and increases with increase in temperature and current density, but it decreases as the [Co2+]/[Ni2+] ratio in the bath increases. The percentage of Co in the deposit increases with increasing cathodic current density, temperature and increasing Co2+ ion concentration. The structure and surface morphology of the deposit were studied by XRD, ALSV and SEM. The results showed that the alloys consisted of a single solid solution phase with a hexagonal close packed structure.

The cathodic polarization, cathodic current efficiency of codeposition, composition and structure of Co–Cu alloy as a function of bath composition, current density and temperature were studied. Electrodeposition was carried out from solutions containing CuSO4 · 5H2O, CoSO4 · 7H2O, Na2SO4 and NH2CH2COOH. The cathodic current efficiency of codeposition (CCE) was high and it increased with increasing temperature and Cu2+ content in the bath, but it decreased with current density. The codeposition of Co–Cu alloys from these baths can be classified as regular. The Co content of the deposit increased with Co2+ content and current density and decreased with glycine concentration and temperature. The structure of the deposited alloys was characterized by anodic stripping and X-ray diffraction techniques. The data showed that the deposited alloys consisted of a single solid solution phase with a face-centred cubic (f.c.c.) structure.

An alkaline bath containing CoSO4 · 7H2O, ZnSO4 · 7H2O, Na2SO4 and NH2CH2COOH is proposed for the deposition of thin layers of Zn–Co alloys onto steel substrates. Electrodeposition was carried out at 0.216–1.080 A dm−2, pH 10 and 10–55 °C. The influence of bath composition, current density and temperature on galvanostatic cathodic polarization, cathodic current efficiency and alloy composition was studied. Different proportions of the two metals were obtained by using different deposition parameters, but at all Zn(II)/Co(II) ratios studied, preferential deposition of zinc occurred and anomalous codeposition took place. Increasing the bath temperature enhanced the cobalt content in the deposit. X-ray diffraction measurements indicated that the phase structure of the deposits was controlled by the applied current density. The Co5Zn21 phase was formed at low current density, while the CoZn13 phase was formed at high current density. The potentiodynamic dissolution of the coatings showed that they contained Zn–Co alloy of different content and structure.

The production of cationised cotton fabrics, via Sandene 8425, 1, 1-dimethyl-3-hydroxy azetidinium chloride and 1, 1-diethyl-3-hydroxy azetidinium chloride, greatly enhances the exhaustion and fixation of acid dyes. This paper shows that these dyes can be used in the absence of salt in a neutral medium. Wash fastness, light fastness and other properties were studied.

Egyptian cotton straw powder was acid hydrolized in presence of coal tar phenols fraction (b.r. 170–185°C) to give the phenols‐furfural resin. Homopolyepoxy resin was prepared via condensation of epichlorohydrin with phenols‐furfural resin. Similarly copolyepoxy resin was also prepared from epichlorohyhdrin, phenols‐furfural resin and prepared bisphenol A based on coal tar phenols fraction. A study of curing these epoxy resins at 170–185°C with phthalic or maleic anhydride also curing at room temperature with amine was carried out. Also the effect of the addition of kaolin as a filler was investigated to find the optimum condition which allow the cured resin to act as wood adhesive. The obtained results were comparable with those of some commercial adhesives.

An easy procedure for the preparation of solutions containing certain types of reactive dye and their subsequent application on cotton is described. This procedure takes advantage of the expected high reactivity of these dyes, which have adjacent hydroxy and amino groups in the molecule, and strives to evade the problems usually associated with the preparation and application of such dyes in the solid form. Several factors that affect the colour strength of reactive dyeings thus obtained are investigated. Possible disadvantages when applying this procedure are discussed.

A simple procedure for the formation and fixation of a reactive dye, having a high-affinity skeleton, within the interstices of cotton fibres is described. It involves dyeing cotton with Direct Blue 2, followed by treating the dyed fibre with cyanuric chloride and finally reacting the dichlorotriazinyl-dye, presumably formed in situ, with the neighbouring cellulosic chains. Factors affecting dye fixation and the mechanisms involved are studied.

Phenols‐furfural resin (analogous to novolake type phenol‐formaldehyde) was obtained from condensation reaction between cotton straw powder and phenolic product in presence of an inorganic acid. The optimum conditions for resin formation were confermed by infrared spectra and its characteristics were determined.

Turbulent premixed combustion under certain conditions may lead tolarge flame speeds sufficient to cause significant damage to nearby structures. Experiments, both large and small scale, have confirmed that obstructions cause severe flame acceleration to occur. In these cases, flame speeds as high as 800 ms−1 may be achieved. In this work experimental investigation of some factors affecting flame acceleration in a semiconfined channel has ben carried out. The experimental facility and the developed ionization gap measuring technique are also described. It has been found that the presence of obstacles, degree of confinement, heiht of fuelair cloud (FAC), as well as fuel concentration gradient in the FAC have profound effects on the rate at which the flame accelerates. Finally, consideration of the flame acceleration as a possible mechanism for the transition to detonation will be discussed.

This study outlines the kinetic rate of adsorption of three commercial anionic direct dyestuffs by two types of Egyptian kaolinite, i.e. Sinai and Kalabsha. The structure of the dyestuffs, as well as the structure of kaolinites. plays a great role in dye adsorption. The Sinai kaolinite shows a higher apparent ion-exchange capacity than the Kalabsha one. Some factors affecting dye adsorption are investigated, e.g. kaolinite and dye concentration, shaking time, temperature and addition of electrolytes.

Addition of the reactive compound 2,4-dichloro-6-(4-sulphoanilino)-s-triazine to dyebath solutions of several direct dyes under specified conditions generally leads to an increase in colour strength of dyed fabrics even after several washings. This increment depends, however, on the structure of dyestuff used. Direct Blue 2 (C.I. 22590) seems to be most suited for this procedure. Factors affecting the colour strength of the latter dye under different conditions were investigated.

A comparison was made of the relief of pain after operation, obtained following the i.v. administration of buprenophrine and pethidine in 60 patients with lower abdominal incisions. No difference could be detected between the maximum analgesia produced by eigher drug, but analgesia following buprenorphine appeared to last about four times as long as that following pethidine. When the drugs were compared on a "dose per body weight" basis the results supported a ratio of potency in the order of 1 : 200 in favour of buprenorphine. Vomiting, drowsiness and dizziness were less frequent following buprenorphine, but a similar frequency of nausea was observed with both agents. Marked miosis occurred 5--10 min after the i.v. injection of buprenorphine, but no serious side-effects were observed with either drug. The i.v. injection of buprenorphine, but no serious side-effects were observed with either drug. The i.v. administration of buprenorphine appeared to be effective in the management of pain after operation in patients with lower abdominal incisions.

Multiple choice questions have been used to assess the progress of 105 postgraduate anaesthetic students over three successive academic years, at the University of Liverpool. Analysis of the results of these tests had revealed a good correlation existing between the MCQ scores obtained and success or failure in the Colleges' Primary FFARCS examinations. Both retrospective and prospective analyses are presented. The value of serial MCQ tests is discussed in relation to encouraging and discouraging students in sitting postgraduate examinations. Analyses of these tests are also of value in planning teaching programmes, assessment of teaching and predicting overall successes and failure of students.

A study was carried out during the period, June 1976–May 1978 on the amount and composition of dust deposits in Helwan Industrial Area, about 24 km south-east of Cairo, Egypt. Importance was given for the construction-cement industry as a major source responsible for polluting the atmosphere of this region. 24 dust-fall collectors were set up at different sites covering the various activities in the studied area. Monthly collected deposits were estimated for their total weights, and were chemically analysed for watersoluble and insoluble components.

Effects of transport phenomena, including those of viscosity, heat conduction and radiation, are studied for point explosions in perfect gases in plane, cylindrical and spherical geometries. Radiation is considered to be of the diffusion type, while the transport coefficients are taken as proportional to appropriate powers of temperature. These powers are determined by the conditions leading to self-similarity. The structure of self-similar flow fields is then fully determined for different values of specific heat ratios and Reynolds numbers.

Real gas effects of compressibility, vibrational excitation, dissociation, ionization and electronic excitation are taken into account in blast wave formulation. Residual property concepts, as well as those of equilibrium quantum statistical thermodynamics, are utilized to relate the different microscopic internal energy excitation levels to macroscopic thermodynamic properties. Jump conditions across the shock front are then evaluated and a non-self-similar quasi-similar solution is obtained for the adiabatic point explosion problem. From the results it appears that temperature profiles are affected most by the real gas properties of the medium. Some of their effects are evident in density profiles, while pressure and particle velocity are relatively unaffected. Finally, the shock front decays slower than in the perfect gas case, especially during the initial stages of propagation.

Alkali, earth alkali and heavy metals were determined in dust-fall deposits in various sites in the Helwan industrial area, about 24 km south-east of Cairo. The ash fraction of the deposits, collected monthly during 24 consecutive months (June 1976–May 1978), was chemically analysed by means of atomic absorption spectrophotometry. The results obtained show that: 1. 1. Aerosol metals originate from various man-made and natural sources. 2. 2. There is a strong relationship between the metal concentration in the atmosphere and the prevailing weather; and 3. 3. Na, Mg, Ca and Fe are the major constituents in the total dust-fall, while Zn is a minor constituent, and other elements such as Cr, Mn, Co, Ni, Cu, Cd and Pb, are considered as trace elements.

The synthesis, some dyeing, and fastness properties of several new dispersed and acid dyes derived from the amino-benzotriazoles 1 & 3 and the aminobenzimidazoles 2a, 2b & 4 are described. The suitability of the amino derivatives 1, 2a, 2b, 3 & 4 as bases for azoic dyeing has also been studied. Several interesting observations between the properties of some synthesised dyes and the corresponding benzene or naphthalene analogues are cited.

The action of nitrous acid on 2-amino-6-nitro-N-methylaniline affords 1-methyl-7-nitro-benzotriazole. The corresponding 7-amino-, acetylamino-, and benzoylamino-derivatives have been prepared. Thus the compounds and their derivatives previously assigned the 1-methyl-7-nitro structure are the 4-substituted compounds.

Die Aminierung von 5-Nitro-, 1-Methyl-5-nitro, 2-Methyl-5-nitro- und 2-Phenyl-5-nitro-benzotriazolen fuhrt zu den entsprechenden 4-Amino-5-nitro-benzotriazolen 3a, 3b, 4a und 4b, welche katalytisch zu den zugehorigen 4.5-Diamino-Derivaten reduziert werden. Die Diamine werden zu Benzo-bistriazol und Imidazo-benzotriazol-Derivaten cyclisiert. Studies in the Benzotriazole Series, V1). Synthesis of Benzo-bistriazoles and Imidazo-benzotriazole Derivatives Amination of 5-nitro-, 1-methyl-5-nitro-, 2-methyl-5-nitro-, and 2-phenyl-5-nitro-benzotriazoles yields the corresponding 4-amino-5-nitro-benzotriazoles 3a, 3b, 4a and 4b. The latter compounds are catalytically reduced to give the corresponding 4,5-diamino derivatives. The diamines are cyclised to give the benzo-bistriazole and imidazo-benzotriazole derivatives.

Die Darstellung von 6-Nitro-1-methyl-benzotriazol (4) aus 4-Nitro-o-phenylendiamin wird beschrieben. Mehrere Umsetzungen dieser Verbindung sowie des durch Reduktion erhaltenen 6-Amino-Derivats 5 werden aufgefuhrt. Studies in the Benzotriazole Series, IV1). Synthesis of 6-Nitro-1-methylbenzotriazole and Some Derivatives 6-Nitro-1-methylbenzotriazole (4) is prepared from 4-Nitro-o-phenylenediamine. Several reactions of this compound and of the corresponding 6-amino compound 5 are described.

Benzotriazole condenses with 2,4-dinitrochlorobenzene (and with picryl chloride) to give a mixture of 1-, and 2-(2,4-dinitrophenyl) benzotriazole (and 1-, and 2-picryl-benzotriazole). 5-Nitro-benzotriazole reacts with 2,4-dinitrochlorobenzene to afford a mixture of 1-(2,4-dinitrophenyl) 5- and 6-nitrobenzotriazole. Proof of the assigned structures is given. The compound reported to be 2-(2,4-dinitrophenyl) 5-nitrobenzotriazole is now shown to be 4,6-dinitro-2-(p-nitrophenyl) benzotriazole. 2-(2,4-Dinitrophenyl) 5-nitrobenzotriazole has been synthesized. 4- and 5-aminobenzotriazoles on reaction with 2,4-dinitrochlorobenzene give the corresponding 2,4-dinitroanilino derivatives