710 research outputs found

    Entanglement transitions in random definite particle states

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    Entanglement within qubits are studied for the subspace of definite particle states or definite number of up spins. A transition from an algebraic decay of entanglement within two qubits with the total number NN of qubits, to an exponential one when the number of particles is increased from two to three is studied in detail. In particular the probability that the concurrence is non-zero is calculated using statistical methods and shown to agree with numerical simulations. Further entanglement within a block of mm qubits is studied using the log-negativity measure which indicates that a transition from algebraic to exponential decay occurs when the number of particles exceeds mm. Several algebraic exponents for the decay of the log-negativity are analytically calculated. The transition is shown to be possibly connected with the changes in the density of states of the reduced density matrix, which has a divergence at the zero eigenvalue when the entanglement decays algebraically.Comment: Substantially added content (now 24 pages, 5 figures) with a discussion of the possible mechanism for the transition. One additional author in this version that is accepted for publication in Phys. Rev.

    Co-trimoxazole induced Stevens-Johnson syndrome in pediatric age group

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    Stevens-Johnson syndrome (SJS) is a serious dermatological disorder commonly caused as idiosyncratic reaction to drugs, the most common ones being antibiotics, anticonvulsants and non-steroidal anti-inflammatory drugs. Here, we report a case of co-trimoxazole induced SJS in a 2 years old male child

    Entanglement between two subsystems, the Wigner semicircle and extreme value statistics

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    The entanglement between two arbitrary subsystems of random pure states is studied via properties of the density matrix's partial transpose, ρ12T2\rho_{12}^{T_2}. The density of states of ρ12T2\rho_{12}^{T_2} is close to the semicircle law when both subsystems have dimensions which are not too small and are of the same order. A simple random matrix model for the partial transpose is found to capture the entanglement properties well, including a transition across a critical dimension. Log-negativity is used to quantify entanglement between subsystems and analytic formulas for this are derived based on the simple model. The skewness of the eigenvalue density of ρ12T2\rho_{12}^{T_2} is derived analytically, using the average of the third moment over the ensemble of random pure states. The third moment after partial transpose is also shown to be related to a generalization of the Kempe invariant. The smallest eigenvalue after partial transpose is found to follow the extreme value statistics of random matrices, namely the Tracy-Widom distribution. This distribution, with relevant parameters obtained from the model, is found to be useful in calculating the fraction of entangled states at critical dimensions. These results are tested in a quantum dynamical system of three coupled standard maps, where one finds that if the parameters represent a strongly chaotic system, the results are close to those of random states, although there are some systematic deviations at critical dimensions.Comment: Substantially improved version (now 43 pages, 10 figures) that is accepted for publication in Phys. Rev.

    Investigating the Mitochondrial Permeability Transition Pore in Disease Phenotypes and Drug Screening

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    Mitochondria act as 'sinks' for Ca2+ signaling, with mitochondrial Ca2+ uptake linking physiological stimuli to increased ATP production. However, mitochondrial Ca2+ overload can induce a cellular catastrophe by opening of the mitochondrial permeability transition pore (mPTP). This pore is a large conductance pathway in the inner mitochondrial membrane that causes bioenergetic collapse and appears to represent a final common path to cell death in many diseases. The role of the mPTP as a determinant of disease outcome is best established in ischemia/reperfusion injury in the heart, brain, and kidney, and it is also implicated in neurodegenerative disorders and muscular dystrophies. As the probability of pore opening can be modulated by drugs, it represents a useful pharmacological target for translational research in drug discovery. Described in this unit is a protocol utilizing isolated mitochondria to quantify this phenomenon and to develop a high-throughput platform for phenotypic screens for Ca2+ dyshomeostasis

    Formulation and Evaluation of Solid Dispersions of Furosemide in Sodium Starch Glycolate

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    Purpose: This investigation was carried out to determine if a solid dispersion of furosemide in sodium starch glycolate (SSG) would enhance the dissolution properties of the drug. Methods: Solid dispersion of furosemide in SSG was prepared in ratios of 1:1 and 1 (furosemide):2 (SSG) by kneading method. In each case, the solid dispersion was characterized by Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), and X-ray diffraction (XRD) to ascertain if there were any physicochemical interactions between drug and carrier that could affect dissolution. Tablets containing the solid dispersion were formulated and their dissolution characteristics compared with commercial furosemide tablets. The dissolution studies were performed at 37 ± 0.5oC and 50 rpm in simulated gastric fluid (pH 1.2). Results: FTIR spectroscopy, DSC, and XRD showed a change in crystal structure toward an amorphous form of furosemide. Dissolution data indicated that furosemide dissolution was enhanced. XRD, DSC, FTIR spectroscopy and dissolution studies indicated that the solid dispersion formulated in 1:2 ratio showed a 5.40-fold increase in dissolution and also exhibited superior dissolution characteristics to commercial furosemide tablets. Conclusion: Solid dispersion technique can be used to improve the dissolution of furosemide Keywords: Solid dispersion, Furosemide, Sodium starch glycolate, Dissolution enhancement, physicochemical characterisationTropical Journal of Pharmaceutical Research Vol. 8 (1) 2009: pp. 43-5

    FAMC: Face Authentication for Mobile Concurrence

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    It has been observed in the last decades that face recognition has acquired a large amount of attention and curiosity. Benefits of this have been seen in quite a few applications. An architecture which has been implemented earlier addresses the face analysis domain. As compared to other biometrics, face recognition is more advantageous but it is particularly subject to spoofing. The whole cost of the system increases since the accuracy of this technique involves the estimation of the three dimensionality of faces. An effective and efficient solution for face spoofing has been proposed in the paper. The growing use of mobile devices has been a growing concern due to their ability to store and exchange sensitive data. Thus this has given encouragement to the interest of people, to exploit their abilities, from one side, and to protect users from malicious data, on the other side. It is important to develop and deliver secure access in this scenario and identification protocols on mobile platforms are another upcoming aspect that also requires attention to deal on the commercial and social use of identity management system. After all these conclusions, the earlier architecture proposes biometrics as the choice for technology which has been also implemented and described in the earlier architecture. The earlier architecture is designed for mobile devices. This architecture thus acts as an embedded application that provides both verification and identification functionality. It includes identity management to support social activities. Examples of identity management system are finding doubles in a social network. Privacy has been provided by these functionalities which help to overcome the security concern. The architecture of FAMC: Face Authentication for Mobile Concurrence is modular. Functionalities like image acquisition, anti-spoofing, face detection, face segmentation; feature extraction and face matching have been provided by its implementation. The behavior of FAMC allows for recognition and best biometrics sample selection. DOI: 10.17762/ijritcc2321-8169.150310

    Impaired cellular bioenergetics caused by GBA1 depletion sensitizes neurons to calcium overload

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    Heterozygous mutations of the lysosomal enzyme glucocerebrosidase (GBA1) represent the major genetic risk for Parkinson’s disease (PD), while homozygous GBA1 mutations cause Gaucher disease, a lysosomal storage disorder, which may involve severe neurodegeneration. We have previously demonstrated impaired autophagy and proteasomal degradation pathways and mitochondrial dysfunction in neurons from GBA1 knockout (gba1^{-/-}) mice. We now show that stimulation with physiological glutamate concentrations causes pathological [Ca^{2+}]_{c} esponses and delayed calcium deregulation, collapse of mitochondrial membrane potential and an irreversible fall in the ATP/ADP ratio. Mitochondrial Ca^{2+} uptake was reduced in gba1^{−/−} cells as was expression of the mitochondrial calcium uniporter. The rate of free radical generation was increased in gba1^{−/−} neurons. Behavior of gba1^{+/−} neurons was similar to gba1^{−/−} in terms of all variables, consistent with a contribution of these mechanisms to the pathogenesis of PD. These data signpost reduced bioenergetic capacity and [Ca^{2+}]_{c} dysregulation as mechanisms driving neurodegeneration

    Benzo-dipteridine derivatives as organic cathodes for Li- and Na-ion batteries

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    Organic-based electrodes for Li- and Na-ion batteries present attractive alternatives to commonly applied inorganic counterparts which can often carry with them supply-chain risks, safety concerns with thermal runaway, and adverse environmental impact. The ability to chemically direct the structure of organic electrodes through control over functional groups is of particular importance, as this provides a route to fine-tune electrochemical performance parameters. Here, we report two benzo-dipteridine derivatives, BF-Me2 and BF-H2, as high-capacity electrodes for use in Li- and Na-ion batteries. These moieties permit binding of multiple Li-ions per molecule while simultaneously ensuring low solubility in the supporting electrolyte, often a precluding issue with organic electrodes. Both display excellent electrochemical stability, with discharge capacities of 142 and 182 mAh g–1 after 100 cycles at a C/10 rate and Coulombic efficiencies of 96% and ∼ 100% demonstrated for BF-Me2 and BF-H2, respectively. The application of a Na-ion cell has also been demonstrated, showing discharge capacities of 88.8 and 137 mAh g–1 after 100 cycles at a C/2 rate for BF-Me2 and BF-H2, respectively. This work provides an encouraging precedent for these and related structures to provide versatile, high-energy density, and long cycle-life electrochemical energy storage materials

    A Study of drug utilization and clinical outcomes in indoor patients of hypertensive disorders of pregnancy

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    Background: Hypertensive disorders of pregnancy are an important determinant of drug use during pregnancy. The aim of study was to assess the clinical outcome and evaluate drug utilization according to WHO core drug prescribing indicators in hypertensive disorders of pregnancy.Methods: This prospective, observational study in a tertiary care hospital was conducted in 150 pregnant women with hypertensive disorders of pregnancy from January 2014 and December 2014 who fulfilled the inclusion criteria. Antepartum and intrapartum care and the maternal and perinatal outcome were noted. The data was analyzed to evaluate clinical outcome and drug utilization according to WHO core drug use indicators.Results: Gestational hypertension was most common among hypertensive disorders of pregnancy seen in 62/150 (41.3%) women. The most common symptom was headache (48%) while sign noted was edema (69%). A total of 66% women had preterm delivery and 42% babies weighed less than 2.5 kg. Average number of drugs per encounter was 9.7. Percentage of drugs prescribed by generic name and from essential drug list was 64% and 79% respectively. The most commonly used drugs were vitamins and minerals prescribed in 100% patients followed by antihypertensive drugs (92%). The most common antihypertensive used were calcium channel blockers and anticonvulsant was magnesium sulphate.Conclusions: There was increased maternal and perinatal morbidity and operative intervention among pregnant women with hypertensive disorders of pregnancy. Most of the drugs were used appropriately and were in accordance with standard guidelines. The important problems identified were inappropriate use of antimicrobials, use of sublingual nifedipine and use of brand names in 1/4th of prescriptions.

    A quinone-based cathode material for high-performance organic lithium and sodium batteries

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    With the increased application of batteries in powering electric vehicles as well as potential contributions to utility-scale storage, there remains a need to identify and develop efficient and sustainable active materials for use in lithium (Li)- and sodium (Na)-ion batteries. Organic cathode materials provide a desirable alternative to inorganic counterparts, which often come with harmful environmental impact and supply chain uncertainties. Organic materials afford a sustainable route to active electrodes that also enable fine-tuning of electrochemical potentials through structural design. Here, we report a bis-anthraquinone-functionalized s-indacene-1,3,5,7(2H,6H)-tetraone (BAQIT) synthesized using a facile and inexpensive route as a high-capacity cathode material for use in Li- and Na-ion batteries. BAQIT provides multiple binding sites for Li- and Na-ions, while maintaining low solubility in commercial organic electrolytes. Electrochemical Li-ion cells demonstrate excellent stability with discharge capacities above 190 mAh g–1 after 300 cycles at a 0.1C rate. The material also displayed excellent high-rate performance with a reversible capacity of 142 mAh g–1 achieved at a 10C rate. This material affords high power capabilities superior to current state-of-the-art organic cathode materials, with values reaching 5.09 kW kg–1. The Na-ion performance was also evaluated, exhibiting reversible capacities of 130 mAh g–1 after 90 cycles at a 0.1C rate. This work offers a structural design to encourage versatile, high-power, and long cycle-life electrochemical energy-storage materials
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