Novel Design of RNA Aptamers as Cancer Inhibitors and Diagnosis Targeting the Tyrosine Kinase Domain of the NT-3 Growth Factor Receptor Using a Computational Sequence-Based Approach

Aptamers, the nucleic acid analogs of antibodies, bind to their target molecules with remarkable specificity and sensitivity, making them promising diagnostic and therapeutic tools. The systematic evolution of ligands by exponential enrichment (SELEX) is time-consuming and expensive. However, regardless of those issues, it is the most used in vitro method for selecting aptamers. Therefore, recent studies have used computational approaches to reduce the time and cost associated with the synthesis and selection of aptamers. In an effort to present the potential of computational techniques in aptamer selection, a simple sequence-based method was used to design a 69-nucleotide long aptamer (mod_09) with a relatively stable structure (with a minimum free energy of −32.2 kcal/mol) and investigate its binding properties to the tyrosine kinase domain of the NT-3 growth factor receptor, for the first time, by employing computational modeling and docking tools.     

Comparative Study of the Synthetic Approaches and Biological Activities of the Bioisosteres of 1,3,4-Oxadiazoles and 1,3,4-Thiadiazoles over the Past Decade

The bioisosteres of 1,3,4-oxadiazoles and 1,3,4-thiadiazoles are well-known pharmacophores for many medicinally important drugs. Throughout the past 10 years, 1,3,4-oxa-/thiadiazole nuclei have been very attractive to researchers for drug design, synthesis, and the study of their potential activity towards a variety of diseases, including microbial and viral infections, cancer, diabetes, pain, and inflammation. This work is an up-to-date comparative study that identifies the differences between 1,3,4-thiadiazoles and 1,3,4-oxadiazoles concerning their methods of synthesis from different classes of starting compounds under various reaction conditions, as well as their biological activities and structure–activity relationship.     

Charge spectra of dyonic quarks

Considering quarks as dyons, we analyze different possibilities for free fractional electric charges and monopoles to coexist. For nonvanishing vacuum angle, electric charges of dyons are not exactly fractional, but carry extra charges proportional to. The average extra charge vanishes for mesons, but not for baryons.     

Variation of radon concentrations in soil and groundwater and its correlation with radon exhalation rate from soil in Budhakedar, Garhwal Himalaya

Radon was measured in soil-gas and groundwater in the Budhakedar area of Tehri Garhwal, India in summer and winter to obtain the seasonal variation and its correlation with radon exhalation rate. The environmental surface gamma dose rate was also measured in the same area. The radon exhalation rate in the soil sample collected from different geological unit of Budhakedar area was measured using plastic track detector (LR-115 type II) technique. The variation in the radon concentration in soil-gas was found to vary from 1098 to 31,776 Bq.m⁻³ with an average of 7456 Bq.m⁻³ in summer season and 3501 to 42883 Bq.m⁻³ with an average of 17148 Bq.m⁻³ in winter season. In groundwater, it was found to vary from 8 to 3047 Bq.l⁻¹ with an average value 510 Bq.l⁻¹ in summer and 26 to 2311 Bq.l⁻¹ with an average value 433 Bq.L⁻¹ in winter. Surface gamma dose rate in the study area varied from 32.4 to 83.6 μR.h⁻¹ with an overall mean of 58.7 μ-R.h⁻¹ in summer and 34.6 to 79.3 μR.h⁻¹ with an average value 58.2 μR.h⁻¹ in winter. Radon exhalation rate from collected soil samples was found to vary from 0.1 × 10⁻⁵ to 5.7 × 10⁻⁵ Bq.kg⁻¹.h⁻¹ with an average of 1.5 × 10⁻⁵ Bq.kg⁻¹.h⁻¹ in summer season and 1.7 × 10⁻⁵ to 9.6 × 10⁻⁵ Bq.kg⁻¹.h⁻¹ with an average of 5.5 × 10⁻⁵ Bq.kg⁻¹.h⁻¹. A weak negative correlation was observed between radon exhalation rate from soil and radon concentration in the soil. Radon exhalation rate from the soil was also not found to be correlated with the gamma dose rate, while it shows a positive correlation with radon concentration in water in summer season. Inter-correlations among various parameters are discussed in detail.      

Interaction of oxygen (O+7) ion beam on polyaniline thin films

High-energy ion beam irradiation of the polymers is a good technique to modify the properties such as electrical conductivity, structural behaviour and mechanial properties. Polyaniline thin films doped with hydrochloric acid (HCl) were prepared by oxidation of ammonium persulphate. The effect of Swift Heavy Ions irradiation on the electrical and structural properties of polyaniline has been measured in this study. Polyaniline films were irradiated by oxygen ions (energy 80 MeV, charge state O⁺⁷) with fluence varying from 1 × 10¹⁰ to 3 × 10¹² ions/cm². The studies on electrical and structural properties of the irradiated polymers were investigated by measuring V-I using four probe set-up and X-ray diffraction (XRD) using Bruker AXS, X-ray powder diffractometer. V-I measurements shows an increase in the conductivity of the film, XRD pattern of the polymer shows that the crystallinity improved after the irradiation with Swift Heavy Ions (SHI), which could be attributed to cross linking mechanism.      

Bio-energetic impairment in human calf muscle in thyroid disorders: a P MRS study

Mitochondrial metabolism particularly oxidative phosphorylation is greatly influenced by thyroid hormones. Earlier studies have described neuromuscular symptoms as well as impaired muscle metabolism in hypothyroid and hyperthyroid patients. In this study, we intend to look in to the muscle bioenergetics including phosphocreatine recovery kinetics based oxidative metabolism in thyroid dysfunction using in vivo ³¹P nuclear magnetic resonance spectroscopy (MRS). ³¹P MRS was carried out at resting state on 32 hypothyroid, 10 hyperthyroid patients and 25 control subjects. Nine out of 32 hypothyroid patients and 17 out of 25 control subjects under went exercise protocol for oxidative metabolism study and performed plantar flexion exercise while lying supine in 1.5 T magnetic resonance scanner using custom built exercise device. MRS measurements of inorganic phosphate (Pi), phosphocreatine (PCr), phosphodiesters (PDE) and adenosine triphosphate (ATP) of the calf muscle were acquired during rest, exercise and recovery phase. PCr recovery rate constant (k_PCr) and oxidative capacity were calculated by monoexponential fit of PCr versus time (t) at the beginning of recovery. During resting condition in hypothyroid patients, PCr/Pi ratio was reduced whereas PDE/ATP and Pi/ATP were increased. However, in case of hyperthyroidism, an increased PCr/Pi ratio and reduced PDE/ATP and Pi/ATP were observed. The results confirmed differential energy status of the muscle due to increased or decreased levels of thyroid hormone. Our results also demonstrate reduced oxidative metabolism in hypothyroid patients based on PCr recovery kinetics. PCr recovery kinetics study after exercise revealed decreased PCr recovery rate constant (k_PCr) in hypothyroid patients compared to controls that resulted in decrease in oxidative capacity of muscle by 50% in hypothyroids. These findings are consistent with a defect of high energy phosphate mitochondrial metabolism in thyroid dysfunction.     

Modulated photophysics of 2-anthracene sulphonate in micellar assembly

The association of a non-ionic surfactant of polyoxyethylene-p-(1,1,3,3-tetramethylbutyl)phenyl ether (Triton X) series with 2-AS in aqueous solution has been studied by means of steady-state, time-resolved fluorescence and fluorescence anisotropy techniques. The effect of the hydrophobic chain length on the structural dynamism of the fluorophore has been reported. Experimental results demonstrate that the equilibrium of this dynamism is sensitive to the environment. The association constant of the probe molecule with the non-ionic micelles of Triton X (TX), location of the probe in the micellar environment, have been determined from the change in emission characteristics of the probe as a function of surfactant concentration. The rate constant of quenching and mode of quenching of probe in micellar media have been ascertained. Quantitative estimates of the micropolarity at the binding sites of the probe molecule have been determined. Some of the environment-dependent relevant fluorescence parameters, fluorescence anisotropy (r), have been monitored for exploring the imposed motional restriction of the microenvironment around the probe. An attempt has been made to correlate the steady-state results with time resolved study.     

Study on the Range of Particles Size Measured by Backscattering Method in Visual‐infrared Incident Spectrum

For the measurement of particles size with backscattering method, the suitable range of particles size measurement have been presented by independent algorithm in Visual‐infrared incident spectrum. We defined the range according to the retrieved results based on the analysis and comparison to many kinds of R‐R distribution function. The simulation computation results showed that the particles size measurement range is from 0.05 μm to 18 μm with incident spectrum from 0.4 μm to 2 μm and different refractive index. The results retrieved were satisfied even if 1 % noise was added into the backscattering intensity.