Studies on Organophosphorus Compounds XI: The Reaction of Phosphorus Reagents With Hydrazonoyl Halides,Hydrazonoyl Azides,and Shiff's Bases

N-(chloro-furan-2-yl)methylene-N′-(4-nitrophenyl)hydrazone (I) reacted with triethylphosphite to produce the phosphonate derivative III. The tetrazine derivative VI was produced by the interaction of I with diethyl-phosphite. Hydrazonoyl azide derivatives VIIIa–c reacted with triphenyl phosphine to form the iminophosphorane derivatives Xa–c. On the other hand, the azide derivative VIIIc reacted with the phosphonium ylide XI to form the 1,2,3-triazole adduct XIII. The reaction of triethyl phosphite with Shiff's bases XIVa–c yielded the corresponding phosphonates XVa–c. The structures of the newly prepared compounds were confirmed with the analytical and spectroscopic evidences.     

Calorimetric, conductometric and density measurements of iteratively filtered water using 450, 200, 100 and 25 nm Millipore filters

This study presents some experimental results on the variation of the physico-chemical properties of pure MilliQ water, when subjected to a procedure of iterated filtration through Millipore filters with porosity ranging from 450 to 25 nm. The parameters measured were: calorimetry, electrical conductivity, density, and pH. Release of chemical impurities can be ruled out due to the nature of the materials used. As in the case of iteratively filtered water prepared using Pyrex glass filters, the specific electrical conductivity and the pH were found to increase with increasing number of iterations. There was also a dependence on the average pore size of the filters. The idea of water as a system capable of self-organization triggered by various perturbations (mechanical and/or electromagnetic) is gaining momentum. It responds to such perturbations by forming dissipative structures, i.e., far-from-equilibrium systems.     

An Improved Measurement of Isotopic Ratios by High Resolution Mass Spectrometry

The study of protein kinetics requires an accurate measurement of isotopic ratios of peptides. Although Fourier transform-ion cyclotron resonance (FT-ICR) mass spectrometers yield accurate mass measurements of analytes, the isotopologue ratios are consistently lower than predicted. Recently, we demonstrated that the magnitude of the spectral error in the FT-ICR mass spectrometer is proportional to the scan duration of ions. Here, we present a novel isotopic ratio extrapolation (IRE) method for obtaining accurate isotopic ratio measurements. Accuracy is achieved by performing scans with different duration and extrapolation of the data to the initial moment of the ion rotation; IRE minimizes the absolute isotopic ratio error to ≤1 %. We demonstrate the application of IRE in protein turnover studies using ²H₂O-metabolic labeling. Overall, this technique allows accurate measurements of the isotopic ratios of proteolytic peptides, a critical step for enabling routine studies of proteome dynamics.      

Homogeneous Liquid–Liquid Microextraction Via Flotation Assistance (HLLME-FA) Method for the Pretreatment of Organochlorine Pesticides in Aqueous Samples and Determination by GC–MS

This work proposes a new, rapid and simple homogeneous liquid–liquid microextraction via flotation assistance technique for the analysis of six organochlorine pesticides in water samples. A special extraction cell was used to facilitate collection of the low-density solvent extract. No centrifugation was required in this procedure. Determination was carried using gas chromatography–mass spectrometry. The water sample solution was then added into the extraction cell containing appropriate mixture of extract and homogeneous solvents. In the first step, a homogeneous solution and then with the continuation of water sample injection, a cloudy solution was formed. Using air flotation, the organic solution was collected at the conical part of the designed cell. The optimized levels of effective parameters were found based on response surface methodology approach. Applying the optimized conditions to the system understudy, the limits of detection of all target analytes were obtained in the range of 1.4–7 ng mL^?1, while the precisions were found to be in the range of 11.08–14.87 (RSD, n = 3). The linearity of the method lay in the range of 10–150 ng mL^?1 with the coefficients of correlation (r ² ) ranging from 0.998 to 0.999.     

2-Keto-3-mercaptocinchoninic Acids as Precursors for Novel Thiazino[6,5-c]quinoline-1,5-dione Derivatives

2-Keto-3-mercaptocinchoninic acid derivatives 1a and b react with Schiff's bases 2a–d in toluene at refluxing temperature to give thiazino[6,5-c]quinoline derivatives 4a–h. Also, refluxing of 1a and b with arylazomalononitriles 5a–d in acetic acid afforded the thiazolo[6,5-c]quinoline derivatives 7a–d. The structure of all the newly synthesized products was confirmed based on elemental and spectral data.     

Photodynamic Tumor Eradication With a Novel Targetable Photosensitizer: Strong Vascular Effects and Dependence on Treatment Repetition Versus Potentiation

A novel pyropheophorbide‐a (PPa) derivative, Ac‐sPPp, was developed in our lab for targeted photodynamic therapy (PDT) and combination therapies. Its versatile peptide moiety, high water‐solubility, amphiphilicity, and micellar aggregation allow efficient coupling to targeting moieties and convenient mixing with other therapeutics. Photosensitizer immunoconjugate (PIC) targeted PDT, using Ac‐sPPp conjugated to therapeutic anti‐epidermal growth factor receptor (EGFR) antibody cetuximab, and PDT + chemotherapy combination treatment, using Ac‐sPPp mixed with stealth liposomal doxorubicin (Doxil), were investigated as promising strategies for potentiating PDT and improving target specificity. Passively targeted PDT with Ac‐sPPp only or surfactant‐solubilized PPa was also investigated for comparison. The A‐431 human vulvar squamous cell carcinoma, xenografted in nude mice, was chosen as a tumor model because of its high EGFR expression and sensitivity to liposomal doxorubicin in vitro. Fluorescence imaging and PDT experiments showed that Ac‐sPPp formulations circulated far longer and provided superior tumor contrast and superior tumor control compared to PPa. Strong PDT vascular effects were observed by laser Doppler imaging regardless of whether Ac‐sPPp was passively or actively targeted. Passively targeted Ac‐sPPp PDT gave equivalent or better tumor control than PIC‐targeted PDT or PDT + Doxil combination therapy, and when treatments were repeated, it also yielded the highest cure rate.     

Synthesis of Diaryl Ethers Through the Copper-Catalyzed Arylation of Phenols with Aryl Iodides Using KF/Al2O3

An efficient synthesis of diaryl ethers by the copper-catalyzed arylation of phenols with a variety of aryl iodide susing KF/Al₂O₃ as a suitable base and CuI and 1,3 diphenyl-1,3 propandione as the catalyst is described.     

Evaluation of the cyclotron production of 165Er by different reactions

Erbium-165 with 10.3 h physical half-life decays completely by electron capture to the ground state of stable isotope ¹⁶⁵Ho and it is an ideal radio lanthanide for Auger electron therapy. Excitation function of ¹⁶⁵Er via ^natEr(p,x)¹⁶⁵Tm → ¹⁶⁵Er, ¹⁶⁶Er(p,2n)¹⁶⁵Tm → ¹⁶⁵Er, ¹⁶⁵Ho(p,n)¹⁶⁵Er and ¹⁶⁵Ho(d,2n)¹⁶⁵Er reactions were calculated using ALICE/ASH (Hybrid and GDH models) and EMPIRE 3.1 codes and then were compared with the reported measurement by experimental data and TENDL-2011. Physical yield and target thickness were evaluated with attention to excitation function, stopping power and SRIM code. ¹⁶⁵Er was produced using the sedimentation technique through the ^natEr (p,x)¹⁶⁵Tm → ¹⁶⁵Er reaction. The deposited target was irradiated with 15 MeV proton beams at 20 μA current for 1 h. The ¹⁶⁵Tm production yield was 26 MBq/μA h at the end of bombardment.     

溶胶-凝胶新方法合成介孔铁酸铜纳米粉体催化剂上CO低温氧化(英文)

Mesoporous CuFe2O4 solid solution nanopowders with high specific surface areas were synthesized by a novel, very simple and inexpensive sol-gel route using propylene oxide as gelation agent, and used as the catalyst in low temperature CO oxidation. The samples were characterized by X-ray diffraction, N2 adsorption-desorption, thermogravimetric/differential thermal analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, and temperature-programmed reduction. The results revealed that the samples have a nanocrystalline structure with crystals in the range of 10 to 25 nm, and that all the catalysts have mesoporous pores. The addition of Cu into iron oxide affected its structural and catalytic properties. The sample containing 15 mol% Cu showed the highest specific surface area and catalytic activity, and showed high catalytic stability in low temperature CO oxidation.     

Synthesis,Characterization, and Antimicrobial Activity of Carboxymethyl Chitosan-Graft-Poly(N-acryloyl,N′-cyanoacetohydrazide) Copolymers

Carboxymethyl chitosan was grafted with N-acryloyl,N′-cyanoacetohydrazide in homogenous aqueous phase using potassium persulfate initiator. The maximum grafting yield achieved was 448% at 0.03 mol/L potassium persulfate, 0.75 mol/L N-acryloyl,N′-cyanoacetohydrazide, and 60°C within 2 h. The grafted copolymers showed better thermal stability than that of carboxymethyl chitosan. The samples with percent grafting values up to 98% were soluble in water, but a higher grafting extent resulted in insoluble copolymers. The grafted copolymers are nontoxic materials and showed an inhibition effect on both Escherichia coli and Staphylococcus aureus bacteria and Aspergillus flavus and Candida albicans fungi better than those of chitosan and carboxymethyl chitosan themselves.