P-P Menschutkin preparation of prototypical phosphinophosphonium salts

Reactions of Me(3)P with alkyl- or arylchlorophosphines yield phosphinophosphonium salts in quantitative yields, demonstrating a Menschutkin P-P methodology that has potentially broad application for element-element bond formation.     

DNA detection on lateral flow test strips: enhanced signal sensitivity using LNA-conjugated gold nanoparticles

A lateral flow test strip assay, enabling sensitive detection of DNA specific to the foodborne pathogen E. coli O157:H7, is described. The use of LNA-conjugated gold nanoparticle probes, along with signal amplification protocols, results in minimum detectable concentrations of ~0.4 nM.     

A protocol for stripping and reprobing of Western blots originally developed with colorimetric substrate TMB

Western blotting is a widely used analytical technique for detection of specific protein(s) in a given sample of tissue/cell homogenate or extract. Both chemiluminescence (CL) and colorimetric detections can be used for imaging Western blots. Colorimetric substrates offer background free, sensitive, and clean imaging results directly on the blotted membrane and provides more accurate profile with respect to prestained marker. However, blots stained with colorimetric substrates cannot be reused since no stripping protocols have been reported for such blots, thus limiting their reuse for detection of another protein. In the present study, for the first time, we report a novel method of stripping Western blots developed with the colorimetric substrate TMB for detection of a low‐abundant protein and reprobing of these blots after stripping for detection of a more abundant protein through CL procedure. The stripping procedure utilizes a stripping buffer consisting of β‐mercaptoethanol, SDS, and Tris‐HCl and a washing buffer consisting of PBS added with 0.1% Tween‐20 involves a series of steps and facilitates accurate detection of the second protein (i.e., more abundant protein) in the stripped blot through CL. The protocol is reproducible and facilitates saving of precious clinical samples, in addition to saving cost and time as compared to the existing procedures.     

Synthesis and anticancer activity studies of alpha-aminoalkylated conjugated nitroalkenes

Novel alpha-aminoalkylated conjugated nitroalkenes which inhibit human cervical cancer (HeLa) cell proliferation by binding to tubulin were synthesized by imidazole/LiCl-mediated reaction of conjugated nitroalkenes with N-tosylimines.     

Biosorption of copper(II) from aqueous solutions by Spirogyra species

Batch studies were conducted to investigate the kinetics and isotherms of Cu(II) biosorption on the biomass of green alga Spirogyra species. It is observed that the biosorption capacity of the biomass strongly depends on pH and algal dose. The maximum biosorption capacity of 133.3 mg Cu(II)/g of dry weight of biomass was observed at an optimum pH of 5 in 120 min with an algal dose of 20 g/L. Desorption studies were conducted with 133.3 mg/g of Cu(II) loaded biomass using different desorption agents including HCl, EDTA, H2SO4, NaCl, and H2O. The maximum desorption of 95.3% was obtained with HCl in 15 min. The results indicate that with the advantages of high metal biosorption capacity and satisfactory recovery of Cu(II), Spirogyra can be used as an efficient and economic biosorbent material for the removal and recovery of toxic heavy metals from polluted water.     

Investigation of properties of Cu containing DLC films produced by PECVD process

Copper containing diamond like carbon (Cu-DLC) thin films were deposited on various substrates at a base pressure of 1×10^?3 Torr using a hybrid system involving DC-sputtering and radio frequency-plasma enhanced chemical vapor deposition (RF-PECVD) techniques. The compressive residual stresses of these films were found to be considerably lower, varying between 0.7 and 0.94 GPa and Cu incorporation in these films improve their conductivity significantly. Their structural properties were studied by Raman spectroscopy, atomic force microscopy, scanning electron microscopy, X-ray photoelectron spectroscopy and X-ray diffraction techniques that clearly revealed the presence of Cu in the DLC structure. Raman analysis yields that Cu incorporation in DLC enhances the graphite-like sp² bonding. However, the sp² bonding was found to continuously reduce with the increasing C₂H₂ gas pressure, this may be due to reduction of Cu nanocrystal at the higher pressure. FTIR results inferred various bonding states of carbon with carbon, hydrogen and oxygen. In addition, hydrogen content and sp³ and sp² fractions in different Cu-DLC films were also estimated by FTIR spectra and were correlated with stress, electrical, optical and nano-mechanical properties of Cu-DLC films. The effect of indentation load (4–10 mN) on nano-mechanical properties of these films was also explored.     

Exploration of small hydroxy‐9,10‐anthraquinones as anthracycline analogues: physicochemical characteristics and DNA binding for comparison

Hydroxy‐9,10‐anthraquinones resemble anthracycline‐based anticancer drugs. By varying the pH of the solution, the proton dissociation constants of 1,2,5,8‐tetrahydroxy‐9,10‐anthraquinone (THAQ) were determined. Interaction of THAQ with calf thymus DNA (ct DNA) was studied by UV–Vis spectroscopy to determine the overall binding constant and site size of interaction. The binding constant values (~10⁴) for THAQ interacting with ct DNA at different pH were an order less than that known for anthracyclines. From knowledge of the overall binding constants at different pH values and the first pK of THAQ, the contribution of each form (neutral and monoanionic) towards overall binding with ct DNA could be obtained under physiological conditions. Hence, knowing the contributions of the neutral and monoanionic forms, it now becomes possible to know the overall binding constant for an interaction of THAQ with ct DNA at any pH. The calculated parameters help in understanding the role of the negative charge on the monoanionic form during interaction and suggests suitable chemical modifications that could prevent the development of such negative charges. This could lead to an increase in binding of THAQ to ct DNA. The study also helps to recognize the importance of sugar units in anthracycline anticancer drugs in DNA interaction. Copyright © 2011 John Wiley & Sons, Ltd.     

Promising Roles of Alternative Medicine and Plant-Based Nanotechnology as Remedies for Urinary Tract Infections

Urinary tract infections (UTIs) are considered to be the most common infections worldwide, having an incidence rate of 40−60% in women. Moreover, the prevalence of this disorder in adult women is 30 times more than in men. UTIs are usually found in many hospitals and clinical practice; as disorders, they are complicated and uncomplicated; in uncomplicated cases, there is no structural or functional abnormality in the urogenital tract. However, obstruction, retention of urine flow and use of catheters increase the complexity. There are several bacteria (e.g., E. coli, Klebsiella pneumoniae, Proteus vulgaris, etc.) successfully residing in the tract. The diagnosis must not only be accurate but rapid, so early detection is an important step in the control of UTIs caused by uropathogens. The treatment of UTIs includes appropriate antimicrobial therapy to control the infection and kill the causal microbes inside the body. A long-time usage of antibiotics has resulted in multidrug resistance causing an impediment in treatment. Thus, alternative, combinatorial medication approaches have given some hope. Available treatments considered Homeopathic, Ayurvedic, Unani, and other herbal-based drugs. There are new upcoming roles of nanoparticles in combating UTIs which needs further validation. The role of medicinal plant-based nanotechnology approaches has shown promising results. Therefore, there must be active research in phyto-based therapies of UTIs, such as Ayurvedic Biology.     

Parametric Study of Driver and Reflector of Single Axis Acoustic Levitator using Finite Element Method

Acoustical Physics - Total radiation force on a spherical levitating object, which is placed between a single axis acoustic levitator, is obtained using finite element simulation. Variation in the...     

Sommerfeld effect in an oscillator with a reciprocating mass

Nonlinear Dynamics - In this paper, the dynamics of a non-ideally driven single-degree-of-freedom vibrating system will be explored in detail. The objective is to describe Sommerfeld effect in a...