In-plane and out-of-plane anisotropic magnetoresistances in La1 − x Pb x MnO3 thin films

The temperature and field dependences of in-plane (IP) and out-of-plane (OP) anisotropic magnetoresistances (AMRs) have been measured in La_{1 ? x} Pb _x MnO₃ (LPMO) thin films having different microstructures, namely the single-crystal (SC), nanocrystalline (NC) and polycrystalline (PC) microstructures. The OP AMR, irrespective of the microstructure, is found to be considerably larger than the IP AMR. The magnetization data show that the larger OP AMR arises because magnetization is favoured in the film plane owing to strain anisotropy. In addition, the temperature and field dependences of both IP and OP AMRs are governed by the crystallinity of the films, indicating that the AMRs are strongly influenced by the magnetization process.     

Risk Minimizing Option Pricing for a Class of Exotic Options in a Markov-Modulated Market

We address risk minimizing option pricing in a regime switching market where the floating interest rate depends on a finite state Markov process. The growth rate and the volatility of the stock also depend on the Markov process. Using the minimal martingale measure, we show that the locally risk minimizing prices for certain exotic options satisfy a system of Black-Scholes partial differential equations with appropriate boundary conditions. We find the corresponding hedging strategies and the residual risk. We develop suitable numerical methods to compute option prices.     

Optical and structural properties of lead iodide thin films prepared by vacuum evaporation method

Thermally processed lead iodide (PbI₂) thin films were prepared by the vacuum evaporation method in a constant ambient. Measured thickness of the film was verified analytically from the optical transmittance data in a wavelength range between 300 and 1600 nm. From the Tauc relation for the non‐direct inter band transition, the optical band gap of the film was found to be 2.58 eV for film thickness 300 nm. X‐ray diffraction analysis confirmed that PbI₂ films are polycrystalline, having hexagonal structure. The low fluctuation in Urbach energy indicates that the grain size is quite small. The present findings are in agreement with the other results. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Meticulous assessment of natural compounds from NPASS database for identifying analogue of GRL0617, the only known inhibitor for SARS-CoV2 papain-like protease (PLpro) using rigorous computational workflow

Molecular Diversity - The latest global outbreak of 2019 respiratory coronavirus disease (COVID-19) is triggered by the inception of novel coronavirus SARS-CoV2. If recent events are of any...     

Sensitive,selective and rapid determination of lafutidine in human plasma by solid phase extraction-liquid chromatography-tandem mass spectrometry

A simple, sensitive and high throughput liquid chromatography-tandem mass spectrometry method has been developed for the determination of lafutidine in human plasma. Sample clean-up involved solid phase extraction of lafutidine along with ranitidine as the internal standard from 100 μL of human plasma. The chromatographic separation is achieved within 2.5 min on a Grace Denali C18 (50 × 4.6 mm, 5 μ) column using 2 mM ammonium acetate, pH 3.0 adjusted with acetic acid and acetonitrile (20: 80, v/v) as the mobile phase. The precursor → product ion transitions for lafutidine (m/z 432.2 → 351.4) and IS (m/z 315.3 → 176.3) were monitored on a triple quadrupole mass spectrometer, operating in the multiple reaction monitoring and positive ion mode. The method is validated over a wide dynamic concentration range of 0.25–1000 ng/mL. The mean relative recovery for lafutidine across quality controls is 97.9%. The relative matrix effect between eight different plasma lots, expressed as coefficient of variation of the slopes of the calibration lines is 1.94. The method is applied to a bioequivalence study of 10 mg lafutidine tablet formulation in 26 healthy Indian male subjects under fasting condition. The reproducibility of study data is demonstrated by analysis of 93 incurred samples.     

Role of plant alkaloids on human health: A review of biological activities

Alkaloids are plant secondary metabolite. They are well known nitrogen-containing natural bioactive compounds. Cutting edge research is going on alkaloids to unravel novel therapeutic approaches. Literature reveals that alkaloids contribute multiple biological activities and some alkaloids transform into active metabolites too. In this review, we have focused on marketed and experimental alkaloids. We have summarized sources and biological activities of reported alkaloids in past decades.     

Enantioselective Synthesis of (−)‐Halenaquinone

The efficient, 12–14 step (LLS) total synthesis of (?)‐halenaquinone has been achieved. Key steps in the synthetic sequence include: (a) proline sulfonamide‐catalyzed, Yamada–Otani reaction to establish the C6 all‐carbon quaternary stereocenter, (b) multiple, novel palladium‐mediated oxidative cyclizations to introduce the furan moiety, and (c) oxidative Bergman cyclization to form the final quinone ring.     

Catalytic Three‐Component Machinery: Control of Catalytic Activity by Machine Speed

Three supramolecular slider‐on‐deck systems DS1 – DS3 were obtained as two‐component aggregates from the sliders S1 – S3 and deck D with its three zinc porphyrin (ZnPor) binding sites. The binding of the two‐footed slider to the deck varies with the donor qualities of and the steric hindrance at the pyridine/pyrimidine (pyr) feet, and was effected by two N_pyr→ZnPor interactions. Accordingly, the sliders move over the three zinc porphyrins in the deck at different speeds, namely with 32.2, 220, and 440 kHz at room temperature. The addition of N‐methylpyrrolidine as an organocatalyst to DS1 – DS3 generates catalytic three‐component machineries. By using a conjugate addition as a probe reaction, we observed a correlation between the operating speed of the slider‐on‐deck systems and the yields of the catalytic reaction. As the thermodynamic binding of the slider decreases, both the frequency of the sliding motion and the yield of the catalytic reaction increase.