Androgen receptor: Structure, signaling, function and potential drug discovery biomarker in different breast cancer subtypes.

The Androgen Receptor (AR) is emerging as an important factor in the pathogenesis of breast cancer (BC), which is the most common malignancy worldwide. >70 % of AR expression in primary and metastatic breast tumors has been observed which suggests that AR may be a new marker and a potential therapeutic target among AR-positive BC patients. Biological insight into AR-positive breast cancer reveals that AR may cross-talk with several vital signaling pathways, including key molecules and receptors. Downstream signaling of AR might also affect many clinically important pathways that are emerging as clinical targets in BC. AR exhibits different behaviors depending on the breast cancer molecular subtype. Preliminary clinical research using AR-targeted drugs, which have already been FDA-approved for prostate cancer (PC), has given promising results for AR-positive breast cancer patients. However, since AR positivity's prognostic and predictive value remains uncertain, it is difficult to identify and stratify patients who would benefit from AR-targeted therapies alone. Thus, the need of the hour is to target the androgen receptor as a monotherapy or in combination with other conventional therapies which has proven to be an effective clinical strategy for the treatment of prostate cancer patients, and these therapeutic strategies are increasingly being investigated in breast cancer. Therefore, in this manuscript, we review the role of AR in various cellular processes that promote tumorigenesis and aggressiveness, in different subtypes of breast cancer, as well as discuss ongoing efforts to target AR for the more effective treatment and prevention of breast cancer.

Selectivity of an Ag/BTO-Based Nanocomposite as a Gas Sensor Between NO2 and SO2 Gases.

The novel Ag/BTO/TiO2 nanocomposite was assessed for its gas-sensing capabilities toward hazardous gases NO2 and SO2. It exhibited p-type behavior with increasing resistance for SO2 with a response and recovery time of ∼5 and ∼2 s, respectively, switching to n-type behavior when exposed to NO2 with a response and recovery time of ∼20 and ∼250 s, respectively. Analyte gas concentrations from 0 to 220 ppm were taken for analysis. Selectivity analysis at room temperature revealed NO2's superior response of ∼20% above 180 ppm, compared to SO2's < 3% response at 180 ppm. NO2(VC) achieved its highest response (∼45%) at 30 ppm and remained constant above 80 ppm, while SO2(VC) peaked at ∼30% at 60 ppm but declined with increasing flow rates. Further, the increasing temperature led to an amplified response for NO2, whereas SO2 showed an increase in response after 180 °C. SO2(VC) exhibited a significant response of ∼70% from 140 °C onward. Additionally, NO2(VC) showed distinct peaks at 160, 250, and 290 °C with responses of 50, 65, and 80%, respectively. The calculated limit of detection values were 236 ppm for NO2, 644.07 ppm for SO2, 401.32 ppm for NO2(VC), and 496.86 ppm for SO2(VC).

p-/n-Type Switching in the Ag/BTO/TiO2 Nanocomposite as a Gas Sensor toward Ethanol, Liquefied Petroleum Gas, and Ammonia.

A novel Ag/BTO/TiO2 nanocomposite was prepared using chemical reduction and sol-gel techniques followed by sintering at ∼950 °C to grow rutile TiO2 and remove organic materials and hydroxyl groups. The structural, optical, morphological, dielectric, and gas-sensing properties were investigated using X-ray diffraction, Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, and inductance, capacitance, and resistance meter, respectively. The surface plasmon resonance peak of Ag was observed at 428 nm, and the absorption edge of the Ag/BTO/TiO2 nanocomposite was observed at 235 nm, with an energy bandgap of 5.42 eV. The dielectric constant is lower at 25 °C and becomes highest at 350 °C and low frequency. The percentage response is better toward ammonia than ethanol and liquefied petroleum gas (LPG) at 25 °C, while it is greater, ∼87%, for LPG at a higher temperature. The p-/n-type switching and vice versa were recorded in the whole gas-sensing measurement. During response-recovery time, the device performed as n type for ethanol and ammonia and p type for LPG, with a very fast response time of ∼4 s for all gases. The recovery time for ethanol was achieved at 20-25 s, while for LPG and ammonia, it was ∼60 s. Moreover, the negative and positive activation energies also confirm the switching behavior in the novel Ag/BTO/TiO2 nanocomposite.

Biochemical, dielectric and surface characteristics of freeze-dried bovine colostrum whey powder.

Colostrum samples of recently registered cow breed "Himachali Pahari" were assorted from high altitude zone (901-2200 m). Prepared bovine colostrum whey powder (BCWP) was analysed for chemical composition, amino acids, minerals, surface morphology (SEM-EDS), FTIR and dielectric properties. Results showed that freeze-dried BCWP contained a considerable amount of nutritional parameters viz IgG (18.55 g/100 g), protein (71.72 g/100 g) and total amino acids (69.64 g/100 g). Additionally, the concentration of essential minerals was found to be adequate, and there was no presence of heavy metals. The BCWP exhibits good dielectric properties (resistance ∼57 M-Ω). SEM-EDS showed the broken up-wards layer structure with the uniform distribution of minerals on the surface. The FTIR spectra confirmed the presence of a higher proportion of ß-sheets and ß-turn structures in BCWP. Thus, on account of good functional and nutritive properties, BCWP could be foreseen as the future of functional food.

Co1-x Ba x Fe2O4 (x = 0, 0.25, 0.5, 0.75 and 1) nanoferrites as gas sensor towards NO2 and NH3 gases.

Co1-x Ba x Fe2O4 (x = 0, 0.25, 0.5, 0.75 and 1) nanoferrites were synthesized using a controlled chemical co-precipitation technique. Their structural, optical, dielectric and gas sensing properties were characterized by X-ray diffractometry, UV-Vis spectroscopy and an LCR meter with a gas sensing unit. The crystalline sizes were estimated using the Scherrer formula and were found to be 7.8 nm, 14.4 nm, 21.8 nm, 16.5 nm and 30.3 nm for x = 0, 0.25, 0.5, 0.75 and 1, respectively. The fundamental optical band gaps were calculated by extrapolating the linear part of (αhυ)2 vs. hυ of the synthesized nanoferrites. The SEM and EDX spectra also confirmed the formation of nanoferrites. Dramatic behavior was observed in the dielectric constant and dissipation factor with varying temperature, which provides a substantial amount of information about electric polarization. The synthesized nanoferrites were tested towards NO2 and NH3 gases. The order of sensitivity (%) towards NH3 was analyzed as x = 0.75 > x = 0.5 > x = 0.25 > x = 0 > x = 1, while the order was x = 0 > 0.75 > 1 > 0.5 > 0.25 for NO2 gas.

Use of flavins as catalyst for the remediation of halogenated compounds.

Flavin-containing monooxygenases (FMOs) are an important monooxygenase system present in living organisms starting from eukaryotes to human beings. They are involved in catalysing wide variety of oxygenation reactions including bioremediation process. The central reaction in these enzymes is always the formation of a peroxyflavin intermediate by reaction of reduced flavin with molecular oxygen. The microenvironment of the peroxyflavin regulates the reactive character of the peroxyflavin. Utilizing this aspect of the biology, chemremediation of aromatic halogenated phenols have been initiated and achieved using flavinium perchlorate salt as catalyst in 38 % yield. The flavinium perchlorate during the reaction gets converted to peroxyflavin with H2O2. This method will be useful in the removal of halogens from aromatic halogenated phenols.

Structural, magnetic and dielectric properties of Ni(1_x)Zn(x)Fe2O4 (x = 0,0.5 and 1) nanoparticles synthesized by chemical co-precipitation method.

Ni(1-x)Zn(x)Fe2O4 (x = 0, 0.5 and 1) ferrite nanoparticles were synthesized by chemical co-precipitation method. X-ray diffraction technique and Rietveld refinement were used to investigate the structural characteristics and determination of the particle size which was found to decrease from 4.9 to 4.1 nm as a function of increasing Zn from 0 to 1.0. Vibrating sample magnetometer was used to study magnetic properties of nickel zinc ferrite nanoparticles. Field-dependent magnetization measurements (M-H curve) at 300 K revealed that Zn substitutions on inverse spinel nickel ferrites enhance the magnetic properties. Magnetization as a function of temperature showed the superparamagnetic behavior of Ni(1-x)Zn(x)Fe2O4 (x = 0,0.5 and 1) nanoparticles. Dielectric permittivity and a.c. conductivity were measured as a function of frequency from 100 kHz to 1 MHz at certain temperatures. The observed response in a.c. conductivity as a function of log of frequency of these nickel zinc ferrite systems was believed to be due to the presence of Maxwell-Wagner type interfacial polarization and hopping of electron by means of quantum mechanical tunneling.