Novel pyrimidinediones and thiazolidinones as anti depressants

2-Mercapto-5-[4'-methoxy phenyl thiourea]-1,3,4-thiadiazole (2a-c) prepared by the condensation of 2-amino-5-mercapto-1,3,4-thiadiazole (1) with substituted phenyl isothiocyanates. Further on cyclisation with malonic acid in the presence of acetyl chloride gave the corresponding 2-mercapto-5-[3-(4-methoxy phenyl)-2-thioxo-2-5-dihydro-4, 6-pyrimidionoyl]-1,3,4-thiadiazole (3a-c) [sequence: see text]. This on further reaction with substituted aryl aldehydes in presence of zinc chloride gave 2-mercapto-5-[3-(4'-methoxy phenyl)-2'-thioxo-2',5'-dihydro-4',6' -pyrimidionoyl 5'-phenyl carboxaldehyde]-1,3,4- thiadiazole (4a-g) [sequence: see text]. The compounds were screened for antidepressant activity and compared with antidepressant (imipramine).     

Regulation of progesterone biosynthesis in the human placenta by estradiol 17 beta and progesterone

The information available concerning the effects of chemotherapy administered during pregnancy is limited and consists of case reports and small series. A registry has been established at the National Cancer Institute, but there are currently only several hundred cases of neonates exposed to chemotherapy registered. All clinicians who care for women receiving chemotherapy during pregnancy should report those experiences to the National Cancer Institute to increase the data base. When chemotherapy is used during the embryogenesis period in the first trimester there is an increased rate of spontaneous abortion and major birth defects. The most toxic chemotherapeutic agents administered during pregnancy are methotrexate and aminopterin and should be avoided when possible, particularly during the first trimester. Pregnancy-related physiologic changes should be kept in mind when dosing and administering cytotoxic chemotherapy. The risk of fetal malformation when chemotherapy is administered during the second and third trimesters is probably not greater than background rate, but there may be a greater risk of stillbirth, fetal growth restriction, premature birth, and maternal and fetal myelosuppression. Breastfeeding should be avoided in women receiving chemotherapy.     

A fast hybrid field-circuit simulator for transient analysis of microwave circuits

A plane-wave-time-domain accelerated time-domain integral-equation solver is coupled to a SPICE-like transient circuit simulator to analyze electromagnetic platform-circuit interactions. The hybrid field-circuit simulator simultaneously solves surface-wire-volume time-domain integral equations that model electromagnetic interactions with the platform and modified nodal analysis equations that govern the behavior of the potentially nonlinear lumped circuits. A shielded nonlinear microwave amplifier is analyzed using the proposed scheme, and its immunity to electromagnetic interference is assessed.     

Electromagnetic fields in magnetic materials: A resource letter

This work is a collection of selected, significant references focussing upon magnetic materials and their interaction with electromagnetic fields. The major topics included are ferrites, plasmas (both atmospheric and laboratory), magnetic composites, magnetic dielectric fluids, ferroelectric liquid crystals. Sections discussing general magnetic materials and phenomena are also included.     

An Approximate Model for Field Service Territory Planning

Field service managers are often faced with the problem of balancing the number of technicians, territory size, and field service quality. This paper presents an approximate state-dependent queuing model that can help field service managers make these tradeoffs. Simulation experiments over a variety of field service environments demonstrate that this model is quite accurate for predicting mean travel time and mean response time. The approximate queuing model has been imbedded in a decision support system and implemented by a Fortune 100 company. Management found the decision support system very useful in making important field service decisions.     

User-centric hybrid semi-autoencoder recommendation system

Recommendation System is one of such solutions to overcome information overload issues and to identify products most relevant to users and provide suggestions to users for items they might be interested in consuming or elements matching their needs. The significant challenge of several recommendation approaches is that they suggested a huge number of things to the target user. But the exciting items, according to the target user, are seen at the bottom of the recommended list. The proposed approach has improved the quality of recommendations by implementing some of the unique features in the new framework of auto encoder called semi-autoencoder, which contains the rating information as well as some additional information of users. Autoencoder is widely used in the recommender system because it gives the best result for feature extraction, dimensionality reduction, regeneration of data, and a better understanding of the user’s characteristics. The experimental results are compared with some established popular methods using precision, recall, and F-measure evaluation measures. Users generally don’t want to see lots of suggestions. With its six building blocks, the proposed approach gives better performance for the top 10 recommendations compared to other well-known methods.

     

Carbothermal Synthesis of Silicon Nitride: Effect of Reaction Conditions

Conditions for carbothermal synthesis of α-Si₃N₄ are presented with special emphasis on the reaction temperature, C:SiO₂ ratio, and precursor mixing. With pure precursors, the conversion temperature is 1500° to 1550°C. An excess of C is necessary for complete conversion, and a simple sol–gelmixing technique provides excellent intermixing of the precursors. Copious flow of N₂ gas throughout the reactor bed is essential if pure Si₃N₄ is to be produced; small concentrations of CO and O₂ promote SiC and Si₂N₂O, respectively.     

Carbothermal Synthesis of Aluminum Nitride Using Sucrose

Several aluminum oxides (α-Al₂O₃, θ-Al₂O₃, and AIOOH) were examined to study the differences in reaction behavior and powder characteristics during carbothermal nitrida-tion to AIN using sucrose and carbon black. The reaction conditions investigated were carbon-to-alumina ratio, reaction temperature, and time. Carburized sucrose resulted in Full conversion to AIN and produced a uniform powder morphology using a near-istoichiometric ratio of C:Al₂O₃ while carbon black required higher C:Al₂O₃ ratios (i.e., >4:1) for full conversion and led to agglomeration of the AIN powder. The most favorable reaction temperature was 1600°C, with the reaction time to full conversion being dependent on the type of Al₂O₃. The particle and agglomerate size of the AIN powders did not change significantly with reaction time. However, the particle size and morphology were strongly dependent on that of the initial AI₂O₃ with sucrose, whereas agglomeration of the AIN occurs when using carbon black. A solid–solid reaction mechanism is proposed.     

Microwave-assisted green synthesis of hybrid nanocomposite: removal of Malachite green from waste water

Gum xanthan/psyllium-based nanocomposite was prepared by microwave-assisted synthetic method for the removal of toxic Malachite green (MG) dye from aqueous solutions. The nanocomposite was prepared by in situ incorporation of the K₂Zn₃[Fe(CN)₆]·9H₂O nanoparticles into the semi-IPN matrix in the presence of ammonium persulphate and glutaraldehyde as initiator-crosslinker system. Liquid uptake efficacy of the hybrid superabsorbent was enhanced through the optimization of different reaction conditions, including APS = 0.027 mol L^?1; glutaraldehyde = 0.053 × 10^?3 mol L^?1; solvent = 8.0 mL; acrylic acid = 10.928 mol L^?1; pH 7.0; reaction time = 60 s and microwave power = 100 % and its thermal behavior was evaluated using TGA-DTG-DTA technique. Candidate nanocomposite was characterized by FTIR, SEM, XRD and UV–visible spectroscopic methods. Various optimized parameters for the efficient removal (83 %) of the Malachite green were adsorbent dose of 800 mg, 14 mg L^?1 initial dye concentration and contact time of 28 h. Further, Langmuir and Freundlich adsorption isotherms showed good applicability in adsorption process of MG onto the nanocomposite with maximum adsorption efficiency of 3.21 mg g^?1. However, for Freundlich isotherm, R ² was around 0.9947 and value of 1/n was less than 1 for the synthesized nanocomposite which indicated that the Freundlich isotherm was more favorable than Langmuir isotherm model along with its usability for wide range of dye concentrations. The nanocomposite was found to be a potential product for dye removal from waste water and could prove to be a boon for textile sector.