Facile One‐Pot Synthesis of 4‐Hydroxy‐2‐methyl‐(2H)‐1,2‐benzothiazine‐3‐sulfonic Acid 1,1‐Dioxide

We report a convenient synthesis of 4‐hydroxy‐2‐methyl‐(2H)‐1,2‐benzothiazine‐3‐sulfonic acid‐1,1‐dioxide (6a) prepared in a novel one‐pot reaction. The synthesis involves two transformations starting from 2‐methyl‐2H‐1,2‐benzothiazin‐4‐(3H)‐one 1,1‐dioxide (7) with an overall yield better than that from the stepwise process, as well as the alternate procedure starting from saccharin (1). One‐pot synthesis of an important intermediate, saccharin‐N‐methane sulfonic acid (4), is also described.     

Solubility of Nonsteroidal Anti-inflammatory Drugs (NSAIDs) in Aqueous Solutions of Non-ionic Surfactants

The solubilities of two nonsteroidal anti-inflammatory (MELOXICAM and CELECOXIB) drugs, were determined in aqueous solutions of nonionic (Tween 20, Tween 80, Brij 30, Brij 35, Triton X 100, Triton X 114) surfactants. These surfactants have different numbers of oxyethylene units and their micelles showed different aggregation numbers. It is shown that these surfactants have different abilities to solubilize NSAIDs drugs. The solubilities of the drugs increased linearly with the increase in concentration of surfactants. The sizes of micelles remained constant with the addition of the drugs, except for Triton type surfactants in which case the size of the micelles decreased. It was observed that the number of oxyethylene units in the surfactants, aggregation number of the micelles and HLB play key roles in solubilizing the drugs.     

Radiosynthesis and biological evaluation of <Superscript>99m</Superscript>TcN-sitafloxacin dithiocarbamate as a potential radiotracer for <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> infection

Sitafloxacin dithocarbamate (SFDE) was synthesized, radiolabeled with technetium-99m (^99mTc) using [^99mTc-N]²⁺ core and evaluated its biological efficacy as a potential radiotracer for Staphylococcus aureus (S. aureus) infection in artificially infected rats (AIRT) and rabbits (AIRB). The radiochemical stability of the ^99mTc labeled SFDE (^99mTcN-SFDE) in saline and serum was determined by radio-HPLC and TLC methods, respectively. After, 1 min of reconstitution the value of radiochemical purity (RCP) was 99.00 ± 0.20% and was remained more than 90% unwavering even after 240 min of the radiolabeling. The ^99mTcN-SFDE complex showed similar radiochemical permanence behavior in serum at 37 °C. The complex showed almost six fold higher specific in vitro binding with living than heat killed S. aureus. Biodistribution behavior was evaluated in S. aureus AIRT and whole body imaging (WBI) in AIRB, respectively. Seven fold up take was observed in infected muscle of the AIRT as compared to inflamed and normal muscles. The disappearance of activity from blood and appearance in urinary system indicated normal route of excretion of the complex. Scintigraphically, it was confirmed that the labeled SFDE was higher accumulated in the infected muscle higher than in inflamed and normal muscle. The high radiochemical stability in saline and serum, specific in vitro binding with S. aureus, precise in vivo distribution in S. aureus AIRT and targeted WBI in AIRB confirmed the possibility of the ^99mTcN-SFDE complex as a potential and promising S. aureus infection radiotracer.     

Ion-induced kinetic electron emission from 6LiF,7LiF and MgF2 thin films

<正>Secondary electron yields for Ar~+ impact on ~6LiF,~7LiF and MgF_2 thin films grown on aluminum substrates are measured each as a function of target temperature and projectile energy.Remarkably different behaviours of the electron yields for LiF and MgF_2 films are observed in a temperature range from 25℃to 300℃.The electron yield of LiF is found to sharply increase with target temperature and to be saturated at about 175℃.But the target temperature has no effect on the electron yield of MgF_2.It is also found that for the ion energies greater than 4 keV,the electron yield of ~6LiF is consistently high as compared with that of ~7LiF that may be due to the enhanced contribution of recoiling ~6Li atoms to the secondary electron generation.A comparison between the electron yields of MgF_2 and LiF reveales that above a certain ion energy the electron yield of MgF_2 is considerably low as compared with that of LiF.We suggest that the short inelastic mean free path of electrons in MgF_2 can be one of the reasons for its low electron yield.     

A Novel Image Encryption Scheme Based on Elliptic Curves over Finite Rings

Image encryption based on elliptic curves (ECs) is emerging as a new trend in cryptography because it provides high security with a relatively smaller key size when compared with well-known cryptosystems. Recently, it has been shown that the cryptosystems based on ECs over finite rings may provide better security because they require the computational cost for solving the factorization problem and the discrete logarithm problem. Motivated by this fact, we proposed a novel image encryption scheme based on ECs over finite rings. There are three main steps in our scheme, where, in the first step, we mask the plain image using points of an EC over a finite ring. In step two, we create diffusion in the masked image with a mapping from the EC over the finite ring to the EC over the finite field. To create high confusion in the plain text, we generated a substitution box (S-box) based on the ordered EC, which is then used to permute the pixels of the diffused image to obtain a cipher image. With computational experiments, we showed that the proposed cryptosystem has higher security against linear, differential, and statistical attacks than the existing cryptosystems. Furthermore, the average encryption time for color images is lower than other existing schemes.     

Effects of pH and Ionic Salts on the Emulsifying and Rheological Properties of Acorn Protein Isolate

This study was designed to evaluate the emulsifying and rheological properties of acorn protein isolate (API) in different pH mediums (pH 3, 7 and 9) and in the presence of ionic salts (1 M NaCl and 1 M CaCl₂). API shows higher solubility in distilled water at pH 7, while at the same pH, a decrease in solubility was observed for API in the presence of CaCl₂ (61.30%). A lower emulsifying activity index (EAI), lower stability index (ESI), larger droplet sizes and slight flocculation were observed for API in the presence of salts at different pHs. Importantly, CaCl₂ treated samples showed relevantly higher EAI (252.67 m²/g) and ESI (152.67 min) values at all pH as compared to NaCl (221.76 m²/g), (111.82 min), respectively. A significant increase in interfacial protein concentration (4.61 mg/m²) was observed for emulsion at pH 9 with CaCl₂, while the major fractions of API were observed in an interfacial layer after SDS-PAGE analysis. All of the emulsion shows shear thinning behavior (τ_c > 0 and n < 1), while the highest viscosity was observed for emulsion prepared with CaCl₂ at pH 3 (11.03 ± 1.62). In conclusion, API, in the presence of ionic salts at acidic, neutral and basic pH, can produce natural emulsions, which could be substitutes for synthetic surfactants for such formulations.     

Green Synthesis of Silver Nanoparticles Using Euphorbia wallichii Leaf Extract: Its Antibacterial Action against Citrus Canker Causal Agent and Antioxidant Potential

Biologically synthesized silver nanoparticles are emerging as attractive alternatives to chemical pesticides due to the ease of their synthesis, safety and antimicrobial activities in lower possible concentrations. In the present study, we have synthesized silver nanoparticles (AgNPs) using the aqueous extract of the medicinal plant Euphorbia wallichii and tested them against the plant pathogenic bacterium Xanthomonas axonopodis, the causative agent of citrus canker, via an in vitro experiment. The synthesized silver nanoparticles were characterized by techniques such as UV-Vis spectroscopy, Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction analysis and transmission electron microscopy. Moreover, the plant species were investigated for phenolics, flavonoids and antioxidant activity. The antioxidant potential of the extract was determined against a DPPH radical. The extract was also evaluated for phenolic compounds using the HPLC technique. The results confirmed the synthesis of centered cubic, spherical-shaped and crystalline nanoparticles by employing standard characterization techniques. A qualitative and quantitative phytochemical analysis revealed the presence of phenolics (41.52 mg GAE/g), flavonoids (14.2 mg QE/g) and other metabolites of medicinal importance. Different concentrations (1000 µg/mL to 15.62 µg/mL—2 fold dilutions) of AgNPs and plant extract (PE) alone, and both in combination (AgNPs-PE), exhibited a differential inhibition of X. axanopodis in a high throughput antibacterial assay. Overall, AgNPs-PE was superior in terms of displaying significant antibacterial activity, followed by AgNPs alone. An appreciable antioxidant potential was recorded as well. The observed antibacterial and antioxidant potential may be attributed to eight phenolic compounds identified in the extract. The Euphorbia wallichii leaf-extract-induced synthesized AgNPs exhibited strong antibacterial activity against X. axanopodis, which could be exploited as effective alternative preparations against citrus canker in planta in a controlled environment. In addition, as a good source of phenolic compounds, the plant could be further exploited for potent antioxidants.     

Non-Linear Transformations and Their Applications in Many-Body Physics

The transformations of the type which convert an exponential into a Gaussian and vice-versa and their applications in various areas of many-body physics are discussed. A new and general method of obtaining such transformations is given using the method of moments. It is compared with other methods which could be employed to obtain such transformations. In atomic physics, we have shown how such transformations can be used to obtain electron interaction energy for the ground state of Helium and Wigner transform for the ground state of H atom. It is shown how to bring angular momentum operators to linear form so that one can use the usual property of rotation operator to calculate their matrix elements. A new way of calculating the approximate eigenvalues of a Hamiltonian is given which combines the variational principles with the principle of maximum entropy. The anharmonic oscillator Hamiltonian is used to illustrate this new method. An interesting aspect of these transformations is that one could combine them with other transformations like Grassmann integration to calculate quantities of physical interest in closed form. A general matrix element of the harmonic oscillator is given which can be used to calculate usual quantities like the trace and density matrix. Some future applications are also discussed.     

Excited-state nonadiabatic dynamics simulations on the heptazine and adenine in a water environment: A mini review

Studying the excited-state decay process is crucial for materials research because what happens to the excited states determines how effective the materials are for many applications, such as photoluminescence and photocatalysis. The high computational cost, however, limits the use of high-accuracy theoretical approaches for analyzing research systems containing a significant number of atoms. Time-dependent density functional theory is a practical approach to investigate the photorelaxation processes in these systems, as demonstrated in the studies of the excited-state decays of heptazine-water clusters and adenine in water described in this review. Here, we highlight the importance of conical intersections in the excited-state decay processes of these systems using the aforementioned examples. In the heptazine-water and adenine-water systems, these intersections are associated with the photocatalytic water splitting reaction, caused by a barrierless reaction called water to adenine electron-driven proton transfer. We expect the result would be helpful for researching the excited-state decays of graphitic carbon nitride materials and DNA nucleotides.     

Interference structures in photoelectron intensity distribution and closed orbit in the system

The European Physical Journal D - The spectrum of quadruply ionized bismuth (Bi V) has been investigated in the vacuum ultraviolet region 190–1900&nbsp;Å. Several bismuth...