A surface-enhanced Raman scattering (SERS) substrate composed of silver nanoparticles (Ag NPs) was synthesized by spark discharge deposition (SDD). The spark-ablated species were directly deposited on a copper substrate at room temperature and atmospheric pressure. Sharp and reproducible SERRS signals from the model molecule Rhodamine B (Rh B) were observed from the prepared substrates. Under optimized deposition conditions, the detection limit of Rh B reached the single molecular level (1.0 × 10−16 M) with an enhancement factor of 3.9 × 1012. This substrate also provided excellent SERS activity toward crystal violet molecule and the representative biomolecule adenine. We were further interested to find that the activity of the prepared substrate responded very sensitively when we changed the morphology of the deposited NPs by adjusting the operating parameters. An increase in the spark time to 20 min increased the particle size and filling factor, which induced the particles to grow into self-assembled dendrite-like structures. We observed the highest intensity in an Ag NP film with an average particle size of 45 nm and filling factor of 0.57. We speculate that the high sensitivity of this substrate may have derived from the high electromagnetic field produced by the tuning of the particle size and the formation of nanogaps (hot spots) between adjacent particles. This method offers a simple, cost effective, eco-friendly route to the synthesis of highly sensitive, reproducible SERS substrates.

This study developed a prototype of a wire-plate air bubbling plasma reactor that can be easily scaled up for wastewater treatment. The electrical characteristics, including the discharge current and average power consumed, of the developed reactor were deeply investigated at different operating parameters and solution conductivities. The performance of the reactor was examined on the basis of energy efficiency and methylene blue (MB) decoloration efficiency. Moreover, the removal of the total organic carbon and the changes of the physicochemical properties of solution, including pH, conductivity, and temperature, were evaluated. The analysis of current discharge and average power consumed showed that the discharge mode in the present reactor is a filamentary streamer. Interestingly, the solution conductivity had no effect on the average power consumed at low applied voltages, due to confinement of the discharge in a small area surrounding the discharge electrode in the gas phase. However, at relatively high voltages, the effect of conductivity on the average power consumed was noticeable, yet it had no effect on the decoloration efficiency at the same average power. The present reactor showed a high energy-efficiency value of 42 g/kWh at 50% decoloration of 30 mg/l MB solution, but it dropped to 14 g/kWh at 97% decoloration. A first-order kinetics model described well the decoloration reaction rates and the overall rate constant correlated linearly to the average power.

Experiments are performed using dry and humid air to clarify the effects of water vapour on the characteristics of surface dielectric barrier discharge (SDBD) and investigate its impact on the performance of the SDBD for decomposition of gaseous naphthalene in air stream. The current characteristics, including the discharge and the capacitive currents, are deeply analyzed and the discharge mechanism is explored. The results confirmed that the humidity affected the microdischarge distribution without affecting the discharge mode. Interestingly, it is found that the water vapour had a significant influence on the capacitance of the reactor due to its deposition on the discharge electrode and the dielectric, which, in turn, affects the power loss in the dielectric and the total power consumed in the reactor. Thus, the factor of the humidity effect on the power loss in the dielectric should be considered in addition to its effect on the attachment coefficient. Additionally, there was an optimum level of the humidity for the decomposition of naphthalene in the SDBD, and its value depended on the gas composition, where the maximum naphthalene decomposition efficiency in O2/H2O is achieved at the humidity level 10%, which was lower than that obtained in air/H2O (28%). The results also revealed that the role of the humidity in the decomposition efficiency was not significant in the humidified O2 at high power level. This was attributed to the significant increase in oxygen-derived species (such as O atoms and O3) at high power, which was enough to overcome the negative effects of the humidity.

Orthogonal moments and their invariants to similarity transformations for monochrome and gray-scale images are widely used in many pattern recognition and image processing applications. Quaternion orthogonal moments are used with color images. Recently, the multi-channel framework is proposed as a successful alternative of the quaternion orthogonal moments in representation and recognition of the color images. In this paper, a new set of multi-channel orthogonal moments and their invariants to rotation, scaling and translation (RST) is proposed for color image representation and recognition. The proposed multi-channel moments are based on the orthogonal radial substituted Chebyshev functions. The multi-channel orthogonal radial substituted Chebyshev moments (MORSCMs) are defined in polar coordinates over a unit circle. An accurate kernel-based method is utilized for accurate computation of the MORSCMs. A series of experiments is performed to validate this new set of multi-channel moments and compare its performance with the existing quaternion and multi-channel orthogonal moments. The obtained results ensure the superiority of the proposed MORSCMs over all existing moments in representation and recognition of the color images.

The antioxidant role of the green tea (Camellia sinensis) extract (GTE) was examined to remedy the toxic effects of (0.2mgl-1) 4-nonylphenol(4-NP). Biochemical parameters, antioxidant enzymes, liver lipid peroxidation (LPO), DNA fragmentation, and apoptosis as well as histopathology of liver of African catfish Clarias gariepinus were considered. Catfishes were divided into four groups: first group (control), second group (0.2mgl-1 of 4-NP), third group (0.2mgl-1of 4-NP +100mg GTE l-1water), and fourth group (0.2mgl-1 of 4-NP +200mg GTE l-1water). The results showed that significant increments of serum glucose, AST, ALT, total protein, total lipids, cholesterol, G6PDH, and cortisol. Meanwhile, serum acetylcholinesterase, ALP, and LDH were significantly reduced. In addition, antioxidant enzymes (SOD, CAT, GST, and TAC) levels were reduced in 4-NP treated fish compared to control. Also, there were significant increments in hepatic LPO, DNA fragmentation, and apoptotic erythrocytes in 4-NP treated fish compared to control. Liver of 4-NP treated fish showed some histopathological alterations such as, vacuolization in hepatocytes, congestion in central vein, infiltration of mononuclear inflammatory cells, and necrosis as well as depletion of glycogen content of liver. Addition of green tea extract into the water restored the alterations in most of those biomarkers induced by 4-NP. We concluded that, GTE has a protective role against hepatic failure, depletion of antioxidant defense, and genotoxicity induced 4-NP in C. gariepinus.

Ultraviolet-A light (UVA)-induced DNA damage and repair in red blood cells to investigate the sensitivity of African catfish to UVA exposure is reported. Fishes were irradiated with various doses of UVA light (15, 30, and 60 min day−1 for 3 days). Morphological and nuclear abnormalities in red blood cells were observed in the fish exposed to UVA compared with controls. Morphological alterations such as acanthocytes, crenated cells, swollen cells, teardrop-like cells, hemolyzed cells, and sickle cells were observed. Those alterations were increased after 24 h exposure to UVA light and decreased at 14 days after exposure. The percentage of apoptosis was higher in red blood cells exposed to higher doses of UVA light. No micronuclei were detected, but small nuclear abnormalities such as deformed and eccentric nuclei were observed in some groups. We concluded that exposure to UVA light induced DNA damage, apoptosis, and morphological alterations in red blood cells in catfish; however, catfish were found to be less sensitive to UVA light than wild-type medaka.

Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease that has a mysterious relationship with malaria infection. The current study was designated to compare between the effect of the live and the gamma irradiated Plasmodium chabaudi infection on BWF1 lupus murine model. A total of 30 female BWF1 mice were randomly divided into three groups (10 mice/group) as follows: group (I) lupus group (lupus non infected); group (II) live malaria infected group (lupus + live malaria infection); and group (III) irradiated malaria-infected group (lupus + gamma irradiated malaria infection). Live P. chabaudi infection was accompanied with a decrease in survival rate and food consumption in comparison to the control group of mice while gamma irradiated P. chabaudi -infection was unable to do this effect. Additionally, live P. chabaudi infection was accompanied with an increased level of proteinuria and increased rate of immune complexes deposition in kidney. Moreover, infection with live, but not gamma -irradiated P. chabaudi was accompanied with an increase in nitric oxide (NO), hydrogen peroxide (H2O2), and Malondialdehyde (MDA) levels in plasma of lupus mice. The levels of both total cholesterol and triglycerides in plasma of lupus mice after live P. chabaudi infection were obviously decreased in comparison to the control group. On the other hand, gamma-irradiated P. chabaudi infection was resembling the control group. Our data revealed that infection of lupus mice with live but not gamma-irradiated P. chabaudi has several histological and biochemical effects.

Streptomyces is a genus of Gram-positive, aerobic, filamentous and non-acid-fast actinobacteria that belongs to the family streptomycetaceae and represents the largest genus of actinobacteria. It is common in various environments; soil, composts, water (rivers and marine) and plants. The genus comprises more than 600 species with validated names. The most interesting features of Streptomyces is its ability to produce bioactive secondary metabolites, such as antifungal, antibacterial, antiviral, antitumor, anti-hypertensives, immunosuppressant, and several others. The genus produces over two-thirds of the clinically useful antibiotics of natural origin related to aminoglycosides, β-lactams, macrolides and tetracyclines. The production of most antibiotics is species specific, and the species produce them to compete with other microorganisms in the same habitats. In addition, these antibiotics protect the plant against microbial pathogens. The objectives of the current review are to shed light on the genus Streptomyces; diversity, general features and the role of this genus in production of highly valuable antimicrobial agents that commonly used in treatment of some virulent pathogens.

The sensory properties of the simplest Probe-1 are reported. Probe-1 exhibits colorimetric and fluorimetric responses towards higher pHs. Also, a borate aqueous solution of Probe-1 (pH = 10) could to detect the presence of Cu2+ in aqueous solution with high selectivity and sensitivity (3 μM). The Probe-1/Cu2+ complex responses selectively towards the presence of S2−, H2PO4- and P2O74- through a de-metallization mechanism, resulting in a fluorescence enhancement of 143%, 97% and 134%, respectively. On the other hand, the Probe-1 absorbance increases significantly only by S2- (131%). Furthermore, Probe-1 executes many logic gates such as XOR, AND, INHIBIT, IMPLICATION, TRANSFER and NOT TRANSFER.

In this work I present a novel method to prepare ultra small bare gold clusters (Aun) loaded over different supports. Size selected gold clusters protected by glutathione ligand (Au25(SG)18) was prepared and deposited over aluminium dioxide (Al2O3 Puralox SCCa-190HPV) and anatase titanium dioxide (TiO2) by impregnation method with doping percentage 0.5 and 1 wt %. Then the doped catalysts were irradiated 1 h by microwave synthesis labstation at 80
C and 500 W to remove the glutathione ligands (GSH) and leave the bare gold clusters (Au25) supported over alumina and titania as a strategy for enhancing their catalytic activity and selectivity. The high resolution transmission electron microscope analysis confirmed the particle size of protected (1 wt % Au25(SG)18/Al2O3) and bare (1 wt % Au25/Al2O3) gold clusters over alumina have the same size distribution (~1 nm). The TEM images of doped gold clusters over TiO2 before and after microwave treatment are clearer than alumina. This means the gold clusters over alumina and titania did not suffer from any agglomeration by microwave treatment. From nitrogen sorption isotherms at 196
C for the protected and bare gold clusters over supports showed two different loop types of isotherms H3 and H1, respectively. Their specific surface area SBET, pore volume and average pore diameter were calculated. The pore size distribution of supported gold clusters before and after microwave treatment was measured. These results confirmed the ligands were removed from the supported gold clusters by microwave treatment. The pores in alumina and titania which were blocked by the protected clusters have become available. Reduction of 4-nitrophenol (4-NP) into 4- aminophenol (4-AP) in presence of NaBH4 was used as a test reaction to compare the catalytic activity of supported bare and protected gold clusters over alumina. The results showed that the 1 wt % Au25/ Al2O3 catalyst exhibited the best catalytic performance in the reduction of 4-NP into 4-AP and revealed 100% conversion following 90 s stirring at room temperature. The extreme catalytic activity of the ultra small gold clusters attributed to their electronic properties and geometrical configuration.