A facile synthesis of ethyl α-cyano-β-amincacrylates and related compounds

Ethyl-α-cyano-β-aminoacrylates (I) have been used as intermediates in the synthesis of pyrimidine derivatives and I(R=H,CH3, C6H5) have been obtained by the condensations of ethyl cyanoacetate with amidines and iminoethers, in relatively poor yields. We now report that both biprotic and monoprotic carbothioamides-thioformamide, thiobenzamides, phenylthioacetamide, quinazolin-4(3H)-thione and pyrrolidin-2(1H)-thione condense with ethyl bromocyanoacetate, with extrusion of sulphur, to form ethyl α-cyano-β-aminoacrylate (I, R=H), ethyl α-cyano-β-aminocinnamates (I, R=-C6H5,-C6H4-OCH3, -C6H4-NO2,P), ethyl α-cyano-β-amino-β-benzylacrylate (I, R= -CH2C6H5), ethyl-α-cyano Δ4(3H), quinazolineace tate (II) and ethyl α-cyano-Δ2,α, pyrrolidineacetate (III) (Table) respectively

Modelling interaction forces at a curved physical human-exoskeleton interface

In virtual modelling of exoskeletons, the human-exoskeleton interface is often simplified by modelling the interface forces at a single point instead of contact forces due to the straps or cuffs. In the past, force-generating elements (FGEs) have been used to predict ground reaction forces. However, unlike the ground, which is a planar surface, the human-exoskeleton interface presents curved surfaces. This work discusses the modifications required for using the FGEs for predicting the curved human-exoskeleton interface forces of a passive lower-limb exoskeleton, the Chairless Chair. A pressure mat was positioned at the human-exoskeleton interface to measure the area of contact and the centre of pressure (CoP) in three different sitting conditions. The strength of the FGEs was analysed in detail and its optimization based on the model outputs is discussed. The strength affects the model assistance and the CoP, and these outputs could be used to identify the optimal value of the strength. The strength of the FGEs affects the biomechanical outputs from the model also. Therefore, it is crucial to select the correct value of the strength. The results of this work would be useful for the detailed modelling of the human-exoskeleton interface

Recent Update on Serum Alkaline and Acid Phosphatases in Pre- and Postoperative Breast Cancer Patients

Background: Breast carcinoma in females is an ever-growing malaise with significant mortality and morbidity. In resource-poor settings, the need for a cost-effective and reliable diagnostic tool is of utmost importance.Methods: In the present study, 54 histopathologically proven breast cancer patients were investigated for their pre- and postoperative serum ALP and ACP levels.Results: A total of 34 cases (belonging to the age interval of 40–60 years) exhibited a significant drop in serum ALP level after surgery (P = 0.002). Although the serum ACP also showed a postoperative decline, it was not as significant as that of serum ALP.Conclusion: The role of serum ALP and ACP in the diagnosis, prognosis, and monitoring/surveillance of breast carcinoma cannot be underestimated particularly in third-world countries lacking in medical infrastructure or resource-poor settings. Keywords: alkaline phosphatase, acid phosphatase, breast cancer, malignanc

Measurement of femtosecond Polarization Mode Dispersion (PMD) using biased p-shifted low-coherence interferometry.

Conventional low-coherence interferometry (LCI) can be employed in the measurement of polarization mode dispersion (PMD) of fiber-optic components and fibers. However, the smallest PMD, which can be measured using this technique, is limited by the coherence length of the source. We propose a biased p-shifted Michelson interferometer where a birefringent crystal is inserted in front of the interferometer to introduce a bias differential group delay (DGD) larger than the coherence time of the source. In this way, the limitation imposed by the source coherence time has been overcome and PMDs much smaller than the source coherence time, in the order of several femtoseconds, can be measured. Experimental results for the PMD have been shown and compared with Jones matrix eigen-analysis. The theoretical model confirms the experimental observations

A case report on usage of rituximab on complicated steroid-dependent nephrotic syndrome

Nephrotic syndrome (NS) is one of the common yet challenging childhood disease. Treating NS with immunosuppressants like corticosteroids is typically effective. However, there are significant evidences which displayed resistance patterns to the former drugs. Here in this case, a male patient came to the nephrology department with the history of steroid dependant nephrotic syndrome with complaint of its infrequent relapse. The condition was complicated since, the patient was on multiple steroids even after which there were recurrent episodes of syndrome. Considering the status, Mycophenolate mofetil was added as a supportive treatment for the management of the disease along with steroids, still the outcome was unremarkable. Hence, rituximab was ordered (four cycles). The outcome this time was appreciable, rituximab administration produced a positive result. No events were recorded during the treatment duration.

Malaria in Pregnancy

Malaria infection during pregnancy is an important public health problem with substantial risks to both the mother and foetus. Pregnant women are the most vulnerable group of malaria‐associated morbidity and mortality. A pregnant woman has an increased risk (up to four times) of getting malaria and twice the chances of dying from malaria, compared to a non‐pregnant adult, becuase the immune system is partially suppressed during pregnancy. Malaria in pregnancy not only affects the mother but also has a dangerous sequel for the developing foetus, resulting in premature delivery or intrauterine growth retardation. Diagnosis of malaria in pregnancy remains a challenge due to the low parasite density and placental sequestration of Plasmodium falciparum. Thus, there is an urgent need for new diagnostic methods to detect malarial parasites in the pregnant women. Though antimalarial drugs are available, which can be safely given in the pregnancy, increasing drug resistance of malarial parasite may pose a big problem in the future. In this chapter, we review the burden of pregnancy‐associated malaria (PAM), its pathogenesis, diagnostic issues during pregnancy and recent guidelines for chemoprophylaxsis and treatment

Reliability Based Priority Allocation of Contingencies in a Complex Power System Network

Power system network consists ofsynchronous generators, transmission lines, shunt capacitors, transformers and loads. The reliability of a complete system depends on individual components reliability performance. Reliability study of a network deals with the interruptions of network. The failure of components depends on whether conditions, ageing effects, other components failure and parameter limit violation. The effect of failure on reliability performance of a system is different for every contingency. The only probability of a failure of a component does not decide the severity of failure on the power system but also depends on the rating of component. In this paper, the state probability and severity index due to the failure of each component of a thirty bus interconnected power system network is calculated and then the reliability performance based priority of contingency is investigated

Micro-agglomerate flotation for deep cleaning of coal. Quarterly progress report, July 1-September 30, 1996

The goals of this research program are to demonstrate the technical and economic feasibility of a micro-agglomerate flotation process and to establish the essential criteria for reagent selection and system design and operation. We are investigating the use of a hybrid process - Micro-agglomerate flotation - which is a combination of oil-agglomeration and froth flotation. The basic concept is to use small quantities of oil to promote the formation of dense micro- agglomerates with minimal entrapment of water and mineral particles, and to use froth flotation to extract these micro-agglomerates from the water/dispersed-mineral phase. Since the floating units are agglomerates (about 30-50 mm in size) rather than individual coal particles (1-10 mm) the problems of froth overload and water/mineral carryover should be significantly alleviated

Micro-agglomerate flotation for deep cleaning of coal. Final report

The development of practical technologies for the deep cleaning of coal has been seriously hampered by the problems of carrying out efficient coal/mineral separations at the very fine sizes (often finer than 10 {micro}m) needed to achieve adequate liberation of the mineral matter from the coal matrix. In this investigation a hybrid process--Micro-agglomerate flotation--which is a combination of oil-agglomeration and froth flotation was studied. The basic concept is to use small quantities of oil to promote the formation of dense micro-agglomerates with minimal entrapment of water and mineral particles and to use froth flotation to separate these micro-agglomerates from the water/dispersed-mineral phase. Since the floating units will be relatively large agglomerates (30--50 {micro}m in size) rather than fine coal particles (1--10 {micro}m) the problems of froth overload and water/mineral carryover should be significantly alleviated. There are, however, complications. The process involves at least five phases: two or more solids (coal and mineral), two liquids (oil and water) and one gas (air). It is demonstrated in this study that the process is very sensitive to fluctuations in operating parameters. It is necessary to maintain precise control over the chemistry of the liquid phases as well as the agitation conditions in order to promote selectivity. Both kinetics as well as thermodynamic factors play a critical role in determining overall system response

Self heating Effects in GaN High Electron Mobility Transistor for Different Passivation Material

In this paper effect of self-heating has been studied of AlGaN/GaN high electron mobility transistor (HEMT) for different passivation layers which is promising device for high power at high frequencies. The different passivation layers used are aluminium oxide (Al2O3), silicon nitride (SiN) and silicon dioxide (SiO2). The device GaN HEMT has been simulated and characterised for its thermal behaviour by the distribution of lattice temperature inside the device using device simulation tool ATLAS from SILVACO. The transfer and output characteristics with and without self-heating has been studied for electrical characterisation. The channel temperature for different passivation observed is 448 K, 456 K and 471 K forAl2O3, SiN and SiO2 respectively. The observed different temperatures are due to difference in their thermal conductivity. This channel temperature information is critical to study the reliability of the device at high power levels