Potentiometric Studies on SomeCephalosporin Complexes

Summary.  The interaction of Ca(II), Cu(II), Zn(II), Pb(II), and La(III) ions with the antibiotics cephalexin, cefadroxil, cephaloridine, and cefoperazone as secondary ligands was investigated potentiometrically. The formation constants were determined for a ligand-to-metal ratio of 1:1 at 25°C and KNO₃. The protonation constants of the complexes were evaluated for the system . The order of stability of the binary and ternary complexes were examined. It was found that glycine adds preferably [M(II)-cephalosporin] rather than to the aqueous complexes of M(II). In all cases 1:1:1 complexes were formed. Received February 4, 2000. Accepted (revised) May 10, 2000     

Nanoformulation of Polyphenol Curcumin Enhances Cisplatin-Induced Apoptosis in Drug-Resistant MDA-MB-231 Breast Cancer Cells

Triple Negative Breast Cancer (TNBC) is the aggressive and lethal type of breast malignancy that develops resistance to current therapies. Combination therapy has proven to be an effective strategy on TNBC. We aimed to study whether the nano-formulation of polyphenolic curcumin (Gemini-Cur) would affect the cisplatin-induced toxicity in MDA-MB-231 breast cancer cells. MDA-MB-231 cells were treated with Gemini-Cur, cisplatin and combination of Gemini-Cur/Cisplatin in a time- and dose-dependent manner. Cell viability was studied by using MTT, fluorescence microscopy and cell cycle assays. The mode of death was also determined by Hoechst staining and annexin V-FITC. Real-time PCR and western blotting were employed to detect the expression of BAX and BCL-2 genes. Our data demonstrated that Gemini-Cur significantly sensitizes cancer cells to cisplatin (combination index ≤ 1) and decreases IC50 values in comparison with Gemini-cur or cisplatin. Further studies confirmed that Gemini-Cur/Cisplatin suppresses cancer cell growth through induction of apoptosis (p < 0.001). In conclusion, the data confirm the synergistic effect of polyphenolic curcumin on cisplatin toxicity and provide attractive strategy to attain its apoptotic effect on TNBC.     

A Review with Updated Perspectives on Nutritional and Therapeutic Benefits of Apricot and the Industrial Application of Its Underutilized Parts

Fruits maintain the image as the richest sources of vitamins. Focusing on apricots, utilization of apricot species for many applications is possible due to its various benefits. Many research studies demonstrated different perspectives of apricot, especially in medical used as it can act as antioxidant, anti-inflammatory, and antimicrobial agents. Moreover, in the industrial sectors, apricots can be used in the production of biofuels and batteries. All components of the apricot fruit, including seeds and kernels have been found to possess significant interest. This review is to breach the knowledge gap regarding the key nutrients and chemicals of apricot fruit, contributing to its health-promoting properties to emphasize the noble importance of this fruit in the diet and in the management of several diseases. We also cover the application of apricots in the industry that could be developed as a promising and sustainable source.     

Enhancement of the Protective Activity of Vanillic Acid against Tetrachloro-Carbon (CCl4) Hepatotoxicity in Male Rats by the Synthesis of Silver Nanoparticles (AgNPs)

In the current study, the hepatoprotective activity of vanillic acid, silymarin, and vanillic acid-loaded silver nanoparticles (AgNPs) against CCl₄-induced hepatotoxicity was tested in male rats for four weeks. Thirty male rats were divided into five groups (n = 6). The 1st group was a negative control, the 2nd group was a positive control, the 3rd group was treated with 100 mg/kg b.w. of vanillic acid, the 4th group was treated with 100 mg/kg b.w. of vanillic acid–AgNPs, and the 5th group was treated with 50 mg/kg b.w. of silymarin. The CCl₄-induced hepatic toxicity in the 2nd group was revealed by the liver function and all other biochemical tests. Liver enzymes, bilirubin, lipid peroxidation, lactate dehydrogenase, and interleukin-6 were elevated, whereas, total protein, antioxidant enzymes, and irisin were decreased compared to the negative control. The hepatic tissues were also injured as a result of the CCl₄-induced hepatotoxicity. Treating the hepatotoxic rats with vanillic acid moderately protected the rats of the 3rd group, whereas treatment with vanillic AgNPs and silymarin in G4 and G5, respectively, greatly protected the rats against the CCl₄ hepatotoxicity, approaching the normal biochemical levels and liver tissue appearance. The biochemical tests were confirmed by the histological investigations of liver tissue.     

Degrees-Of-Freedom in Multi-Cloud Based Sectored Cellular Networks

This paper investigates the achievable per-user degrees-of-freedom (DoF) in multi-cloud based sectored hexagonal cellular networks (M-CRAN) at uplink. The network consists of N base stations (BS) and K≤N base band unit pools (BBUP), which function as independent cloud centers. The communication between BSs and BBUPs occurs by means of finite-capacity fronthaul links of capacities CF=μF·12log(1+P) with P denoting transmit power. In the system model, BBUPs have limited processing capacity CBBU=μBBU·12log(1+P). We propose two different achievability schemes based on dividing the network into non-interfering parallelogram and hexagonal clusters, respectively. The minimum number of users in a cluster is determined by the ratio of BBUPs to BSs, r=K/N. Both of the parallelogram and hexagonal schemes are based on practically implementable beamforming and adapt the way of forming clusters to the sectorization of the cells. Proposed coding schemes improve the sum-rate over naive approaches that ignore cell sectorization, both at finite signal-to-noise ratio (SNR) and in the high-SNR limit. We derive a lower bound on per-user DoF which is a function of μBBU, μF, and r. We show that cut-set bound are attained for several cases, the achievability gap between lower and cut-set bounds decreases with the inverse of BBUP-BS ratio 1r for μF≤2M irrespective of μBBU, and that per-user DoF achieved through hexagonal clustering can not exceed the per-user DoF of parallelogram clustering for any value of μBBU and r as long as μF≤2M. Since the achievability gap decreases with inverse of the BBUP-BS ratio for small and moderate fronthaul capacities, the cut-set bound is almost achieved even for small cluster sizes for this range of fronthaul capacities. For higher fronthaul capacities, the achievability gap is not always tight but decreases with processing capacity. However, the cut-set bound, e.g., at 5M6, can be achieved with a moderate clustering size.     

Combining TOUGH2 and FLAC3D to Solve Problems in Underground Gas Storage

This paper describes modeling studies assessing the feasibility of increasing the maximum storage pressure in several underground natural gas storage reservoirs. This required an assessment of the potential for gas transport in the caprock and the geomechanical response to pressure change in the storage reservoir. To solve this problem in an efficient manner, two-phase flow (TOUGH2) and geomechanical (FLAC3D) models were combined in series. The TOUGH2 model was calibrated to fit pressure data collected on-site, from both the reservoir and caprock. The mechanical response of the caprock to increased storage pressure was modeled using FLAC3D, allowing assessment of the induced stresses in formations surrounding the reservoirs. We focused on two sites. In the first, field data were obtained from a deep borehole above the gas reservoir, which provided indirect observations of the geomechanical response of the caprock to pressure changes in the reservoir. In the second, open boreholes intersecting two thin caprock units immediately above the reservoir allowed gas flow to a shallower unit, significantly impacting the modeled fracture gradient.     

Spectrofluorimetric determination of melamine formaldehyde in solid and liquid forms and in wastewater

A new, simple and sensitive spectrofluorimetric method for determination of trace amount of melamine formaldehyde (MF) was developed. In phosphate buffer solution of pH 7.4 MF can remarkably quench the luminescence intensity of toluylene red (NR) at λ_em = 590 nm due to formation of NR-MF ion associate complex. The luminescence intensity of NR-MF complex was in proportion to the concentration of MF and used as photo probe for its determination. The dynamic range for the determination of MF is 7.5–52.5 ppm with detection limit of 4.4 ppm. The method is relatively free from interferences from coexisting substances and used successfully for the determining of MF in powder and liquid forms and in wastewater produced from MF industries. The average recoveries and standard deviations of 98.3 ± 0.6, 98.1 ± 0.6 and 97.3 ± 0.5% were achieved for determination of MF in solid, liquid forms and wastewater, respectively     

Dual Hard/Soft Gold Catalysis: Intermolecular Friedel–Crafts‐Type α‐Amidoalkylation/Alkyne Hydroarylation Sequences by N‐Acyliminium Ion Chemistry

Gold catalysts have been applied in cascade‐type reactions for the synthesis of different nitrogen‐based compounds. The reactions likely proceed by a new gold‐catalyzed cascade intermolecular α‐amidoalkylation/intramolecular carbocyclization cascade process by unifying both the σ‐ and π‐Lewis acid properties of the gold salts. In the first part of this report we show that the σ‐Lewis acidity of gold(I) and gold(III) could be exploited to efficiently catalyze the nucleophilic substitution of various alkoxy‐ and acetoxylactams. The reaction was found to be applicable to a wide range of cyclic N‐acyliminium ion precursors and various nucleophiles, including allyltrimethylsilane, silyl enol ethers, arenes, and active methylene derivatives. As a logical progression of this study, a combined hard/soft binary catalytic gold system was then used to implement an unprecedented tandem intermolecular Friedel–Crafts amidoalkylation/intramolecular hydroarylation sequence allowing an expedient access to new, complex, fused polyheterocyclic structures from trivial materials.     

Photoinduced effects on the optical constants of a-Ge–Se–Bi chalcogenide glassy thin films

In addition to the conversion from p-type to n-type conductivity that occurs in Ge–Se–Bi thin films when Bi is incorporated in a certain concentration. We found that, when these films were illuminated to UV light, after being annealed at glass transition temperature T _g, the photobleaching is dominant for Ge₂₀Se_80?x Bi _x (x=0, 2.5, and 5 at.%), while for Ge₂₀Se_72.5Bi_7.5 photodarkening is dominant. The photoinduced changes in the optical constants were studied. The refractive index (n) has been analysed according to the Wwmple–DiDominico single oscillator model and the values of E _o and E _d for exposed and unexposed films were determined, respectively. The photostructural effects were discussed in the light of single–double well model proposed by Tanaka and chemical bond approach.