Piezoelectric thermo electromechanical energy harvester for reconnaissance satellite structure

Microsystem Technologies - Piezoelectric materials are widely used in aerospace industry as a source of alternate energy for micro or nanoscale electronics because of voltage dependent actuation...     

Synergistic evaluation of AgO2 nanoparticles with ceftriaxone against CTXM and blaSHV genes positive ESBL producing clinical strains of Uro‐pathogenic E. coli

The silver oxide nanoparticles (AgO₂ ‐NPs) were synthesised using silver foil as a new precursor in wet chemical method. X‐ray diffraction analysis shows crystallographic structures of AgO₂ ‐NPs with crystallite size of 35.54 nm well‐matched with standard cubic structure. Scanning electron microscopy analysis clearly shows the random distribution of spherical‐shaped nanoparticles. Energy dispersive X‐ray analysis confirmed the purity of the samples as it shows no impurity element. Fourier transforms infra‐red analysis confirmed the formation of AgO₂ ‐NPs with the presence of Ag‐O‐Ag stretching bond. All the techniques also confirmed the loading of ceftriaxone drug on the surface of AgO₂ ‐NPs. This study also described the effect of AgO₂ ‐NPs having synergistic activity with β lactam antibiotic i.e. ceftriaxone against ESBL generating Escherichia coli (E. coli). Among isolated strains of E. coli, 60.0% were found to be ESBL producer. The synergistic activities of AgO₂ ‐NPs with ceftriaxone suggest that these combinations are effective against MDR‐ESBL E. coli strains as evident by increase in zone sizes. The present study observed rise in MDR‐ESBL E. coli with polymorphism of blaCTXM and blaSHV causing UTI infections in Pakistani population. The antibiotic and AgO₂ ‐NPs synergistic effect can be used as an efficient approach to combat uro‐pathogenic infections.Inspec keywords: antibacterial activity, nanofabrication, nanomedicine, drugs, nanoparticles, microorganisms, crystallites, scanning electron microscopy, silver compounds, X‐ray diffraction, X‐ray chemical analysis, Fourier transform infrared spectra, organic compounds, geneticsOther keywords: synergistic evaluation, clinical strains, silver oxide nanoparticles, silver foil, wet chemical method, X‐ray diffraction analysis, crystallographic structures, standard cubic structure, spherical‐shaped nanoparticles, energy dispersive X‐ray analysis, ceftriaxone drug, synergistic activity, ESBL producer, scanning electron microscopy, Fourier transform infrared analysis, Escherichia coli, blaSHV gene positive ESBL, crystallite size, random distribution, β lactam antibiotics, MDR‐ESBL E. coli strains, polymorphism, blaCTXM, uro‐pathogenic infections, uro‐pathogenic E. coli, AgO₂      

Engineering Stimuli-Activatable Boolean Logic Prodrug Nanoparticles for Combination Cancer Immunotherapy

Prodrug nanoparticles that codeliver the immune modulators to the tumor site are highly recommendable for cancer immunotherapy yet remain challenging. However, effective stimuli-responsive strategies that exploit the endogenous hallmarks of the tumor have paved the way for cancer immunotherapy. For the first time, the development of the Boolean logic prodrug nanoparticles (BLPNs) for tumor-targeted codelivery of immune modulators (e.g., immune activator and immune inhibitor) and combination immunotherapy is reported herein. A library of stimuli-activatable BLPNs is fabricated yielding YES/AND logic outputs by adjusting the input combinations, including extracellular matrix metalloproteins 2/9 (MMP-2/9), intracellular acidity (pH = 5.0–6.0), and reduction (glutathione) in the tumor microenvironment. Tunable and selective control over BLPNs dissociation and prodrug activation is achieved by specifying the connectivity of orthogonal stimuli-labile spacers while exploiting the endogenous signals at the tumor sites. The tumor-specific distribution of the BLPNs and stimuli-activation of the immune modulators for highly efficient cancer immunotherapy are further demonstrated. The results reported in this study may open a new avenue for tumor-specific delivery of immune therapeutics and precise cancer immunotherapy.     

In Situ Generation of Two-Dimensional Au–Pt Core–Shell Nanoparticle Assemblies

Two-dimensional assemblies of Au–Pt bimetallic nanoparticles are generated in situ on polyethyleneimmine (PEI) silane functionalized silicon and indium tin oxide (ITO) coated glass surfaces. Atomic force microscopy (AFM), UV–Visible spectroscopy, and electrochemical measurements reveal the formation of core–shell structure with Au as core and Pt as shell. The core–shell structure is further supported by comparing with the corresponding data of Au nanoparticle assemblies. Static contact angle measurements with water show an increase in hydrophilic character due to bimetallic nanoparticle generation on different surfaces. It is further observed that these Au–Pt core–shell bimetallic nanoparticle assemblies are catalytically active towards methanol electro-oxidation, which is the key reaction for direct methanol fuel cells (DMFCs).     

Application of CuCoMnO x coat by sol gel technique on aluminum and copper substrates for solar absorber application

Solar thermal heaters are used widely in domestic and industrial applications. The main part of solar thermal heaters is the absorber surface which must have a maximum absorptivity (α) and minimum emissivity (ε) of solar radiation. This is achieved by application of selective coating on the absorber surface. In the present work, solar selective CuCoMnO _x spinel films are deposited by sol gel technique using a dip-coating technique on copper and aluminum sheets. The precursor’s ratio Co:Cu:Mn applied is 1:3:3. Different precursor molar ratios were combined with a fixed amount of solvents for the coating process. Process parameters such as withdrawal rate, heat treatment, and substrate materials on the coat characteristics and optical properties were studied. The coated metallic samples were heat treated at 450°C for 30 min in the case of aluminum and at 200°C at different times in the case of copper. Optical properties of the coatings, namely absorptivity (α) and emissivity (ε) were measured and the deposition process parameters were optimized in order to produce the maximum selectivity (α/ε) values. The deposition parameters were found to influence both the thickness and surface roughness of the coatings. As the coating thickness decreases, the absorptivity increases while the emissivity decreases irrespective of the substrate material. It was also observed from the results that when applying the coat on aluminum substrates, a maximum selectivity value of (α/ε) = 31 was realized while for the copper substrates a maximum value of (α/ε) = 81.8 was obtained. The deposited coatings were analyzed using SEM, XRD, and AFM.     

Effects of frying on the fatty acid composition in farmed and wild gilthead sea bream (Sparus aurata)

The effects of frying in soybean (FWSO) and olive oils (FWOO) on the fatty acid composition of farmed and wild gilthead sea bream Sparus aurata were evaluated. The fat content increased with both frying treatments. However, after FWOO the moisture content of the fish was reduced to a greater extent than that in fish FWSO. The concentration of saturated fatty acids (SFA) decreased significantly during both frying processes ( P  < 0.01). However, the concentration of monounsaturated fatty acids (MUFA) increased significantly in fish fried in olive oil ( P  < 0.01). The fried fish contained a higher level of n-6 polyunsaturated fatty acids (PUFA) and a lower level of n-3 PUFA compared to raw fish. The n-3/n-6 ratio decreased in wild fish FWSO and FWOO from 0.94 ± 0.08 to 0.15 ± 0.01 and 0.15 ± 0.02, respectively. In farmed bream, the ratios decreased from 2.51 ± 0.03 to 0.18 ± 0.03 and 0.36 ± 0.01, respectively. The concentration of trans fatty acids decreased significantly in both fish types after frying ( P  < 0.05). The frying process widely affected the EPA and DHA content, limiting the positive effects of n-3 PUFA.     

Self‐Amplified Drug Delivery with Light‐Inducible Nanocargoes to Enhance Cancer Immunotherapy

Chemoimmunotherapy by systemic administration of individual regimens suffers from inconsistent pharmacokinetics profiles, low tumor specificity, and severe side effects. Despite promising nanoparticle‐based codelivery approaches in therapeutics, the pathophysiological barriers of solid tumors are a hurdle for tumor accumulation and deep penetration of the drug‐loaded nanoparticles. A light‐inducible nanocargo (LINC) for immunotherapy is reported. LINC is composed of a reduction‐responsive heterodimer of photosensitizer pheophorbide A (PPa) and indoleamine 2,3‐dioxygenase 1 (IDO‐1) inhibitor, i.e., NLG919, and a light‐activatable prodrug of oxaliplatin (OXA). LINC administrated through intravenous injection is passively accumulated at the tumor site to generate near‐infrared (NIR) fluorescence signal. Under fluorescence imaging guidance, the first‐wave of NIR laser irradiation induce reactive oxygen species (ROS) generation, trigger cleavage of the polyethylene glycol (PEG) corona, and thus promote tumor retention and deep penetration of LINC. When exposed to the second‐wave NIR laser illumination, LINC efficiently elicits the immune response and promotes intratumoral infiltration of cytotoxic T lymphocytes (CTLs). Furthermore, NLG919 delivered by LINC reverses the immunosuppressive tumor microenvironment by suppressing IDO‐1 activity. Chemoimmunotherapy with LINC inhibit the tumor growth, lung metastasis, and tumor recurrence. The light‐inducible self‐amplification strategy for improved drug delivery and immunotherapy shows potential.     

Classification of Honey According to Geographical and Botanical Origins and Detection of Its Adulteration Using Voltammetric Electronic Tongue

Main possible honey fraud is the addition of various sugar syrups. But, there are also other types of fraud, such as deception on the geographical and/or botanical origin product. Providing a product of the hive with full authenticity is therefore crucial for the preservation of beekeeping. In this pursuit, voltammetric electronic tongue (VE-tongue) was employed to classify honey samples from different geographical and botanical origins. Furthermore, VE-tongue was used to detect adulterants such as glucose syrup (GS) and saccharose syrup (SS) in honey. The data obtained were analyzed by three-pattern recognition techniques: principal component analysis (PCA), support vector machines (SVMs), and hierarchical cluster analysis (HCA). These methods enabled the classification of 18 honeys of different geographical origins and 7 honeys of different botanical origins. Excellent results were obtained also in the detection of adulterated honey. Therefore, this simple method based on VE-tongue could be useful in the honey packaging and commercialization industry.     

Distribution and degradation of tetrachlorvinphos on stored faba beans and soya beans

The distribution and degradation of [CH₃-¹⁴C]tetrachlorvinphos in stored fabe beans and soya beans were studied for 30 weeks at moisture contents and temperatures similar to those prevailing under normal storage conditions. Tetrachlorvinphos penetrated the seed coat and the insecticide residues inside the beans increased with storage time. A considerable portion of radioactivity, amounting to about 20–30% of the applied dose in faba beans and 30–40% in soya beans, was present in a non-extractable form. Residues on the seed coat consisted mainly of unchanged insecticide. The internal extract contained both unchanged insecticide and desmethyltetrachlorvinphos which was present in a free and a conjugated form. Dimethyl phosphate and monomethyl phosphate were identified as hydrophilic ¹⁴C-degradation products. The degradation of tetrachlorvinphos proceeded mainly via cleavage of methoxy groups. The nature and percentage of metabolites varied slightly with storage period. A scheme for possible degradation routes of tetrachlorvinphos on stored beans is suggested.