Synthetic pathways to water-soluble phthalocyanines and close analogs

The different types of water-soluble phthalocyanines are presented and their synthesis is reviewed.     

Measurements of indoor radon concentration levels in Kilis,Osmaniye and Antakya,Turkey during spring season

The fact that 50% of the natural radiation dose to which humans are exposed is caused by radon gas makes indoor radon measurements important. In this study, levels of indoor radon gas were measured in 204 houses in Kilis, Osmaniye and Antakya using passive nuclear track detectors. Cr-39 radon detectors were left in the living rooms of participants’ houses, then analyzed at the Radon Laboratory of Health Physics Department in Çekmece Nuclear Research and Training Center (ÇANEM) of Atomic Energy Agency of Turkey (TAEK). Average indoor radon activity concentrations for Kilis, Osmaniye and Antakya were 50 Bq/m³ (1.26 mSv/y), 51 Bq/m³ (1.29 mSv/y) and 40 Bq/m³ (1.01 mSv/y), respectively.     

Asymmetric transfer hydrogenation of aromatic ketones with the ruthenium(II) catalyst derived from C2 symmetric N,N′-bis[(1S)-1-benzyl-2-O-(diphenylphosphinite)ethyl]ethanediamide

Asymmetric transfer hydrogenation of ketones with chiral molecular catalysts is realized to be one of the most magnificent tools to access chiral alcohols in organic synthesis. A new chiral phosphinite compound N,N′-bis[(1S)-1-benzyl-2-O-(diphenylphosphinite)ethyl]ethanediamide (1), has been synthesized by the reaction of chlorodiphenylphosphine with N,N′-bis[(1S)-1-benzyl-2-hydroxyethyl]ethanediamide under argon atmosphere. The oxidation of 1 with aqueous hydrogen peroxide, elemental sulfur or grey selenium in toluene gave the corresponding oxide 1a, sulfide 1b and selenide 1c, respectively. Pd, Pt and Ru complexes were obtained by the reaction of 1 with [MCl₂(cod)] (M: Pd 1d, Pt 1e) and [Ru(p-cymene)Cl₂]₂1f, respectively. All these new complexes were characterized by using NMR, FT-IR spectroscopies and microanalysis. Additionally, as a demonstration of their catalytic reactivity, the ruthenium complex 1f was tested as catalyst in the asymmetric transfer hydrogenation reactions of acetophenone derivatives with iPrOH was also investigated.     

Effective field theory of a topological insulator and the Foldy–Wouthuysen transformation

Employing the Foldy–Wouthuysen transformation, it is demonstrated straightforwardly that the first and second Chern numbers are equal to the coefficients of the 2+1 and 4+1 dimensional Chern–Simons actions which are generated by the massive Dirac fermions coupled to the Abelian gauge fields. A topological insulator model in 2+1 dimensions is discussed and by means of a dimensional reduction approach the 1+1 dimensional descendant of the 2+1 dimensional Chern–Simons theory is presented. Field strength of the Berry gauge field corresponding to the 4+1 dimensional Dirac theory is explicitly derived through the Foldy–Wouthuysen transformation. Acquainted with it, the second Chern numbers are calculated for specific choices of the integration domain. A method is proposed to obtain 3+1 and 2+1 dimensional descendants of the effective field theory of the 4+1 dimensional time reversal invariant topological insulator theory. Inspired by the spin Hall effect in graphene, a hypothetical model of the time reversal invariant spin Hall insulator in 3+1 dimensions is proposed.     

Optimal Keyword Bids in Search-Based Advertising with Stochastic Advertisement Positions

US expenditures on search-based advertising exceeded $12 billion in 2010. Advertisers bid for keywords, where bid price determines ad placement, affecting click-through and conversion rates. Advertisers must select keywords, allocating each a proportion of their fixed daily budget. In this paper, we construct a stochastic model for the selection and allocation process. We provide analytical results for the single-keyword problem and examine the multiple-keyword problem numerically. We investigate trade-offs between keywords given varying levels of risk and return. We show the implications of enforcing a probabilistic budget constraint. Our paper provides a critical analysis of the advertiser’s problem that may guide future research.     

Characteristics of nanosized LiNi x Fe1−x PO4/C (x = 0.00–0.20) composite material prepared via sol–gel-assisted carbothermal reduction method

Pure LiFePO₄ and LiNi _x Fe_1?x PO₄/C (x?=?0.00–0.20) nanocomposite cathode materials have been synthesized by cheap and convenient sol–gel-assisted carbothermal reduction method. X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy, and inductively coupled plasma have been used to study the phase, morphology, and chemical composition of un-doped and Ni-doped materials. XRD patterns display the slight shrinkage in crystal lattice of LiFePO₄ after Ni²⁺ doping. The SEM images have revealed that Ni-doped particles are not agglomerated and the particle sizes are practically homogeneously distributed. The particle size is found between 50 and 100 nm for LiNi_0.20Fe_0.80PO₄/C sample. The discharge capacity at 0.2 C rate has increased up to 155 mAh g^?1 for the LiNi_0.05Fe_0.95PO₄/C sample and good capacity retention of 99.1 % over 100 cycles, while that of the unsubstituted LiFePO₄/C and pure LiFePO₄ has showed only 122 and 89 mAh g^?1, respectively. Doping with Ni has a noticeable effect on improving its electrical conductivity. However, serious electrochemical declension will occur when its doping density is beyond 0.05 mol LiNi_0.20Fe_0.80PO₄/C electrode shows only 118 mAh g^?1, which is less than un-doped LiFePO₄/C sample at 0.2 C. The cycling voltammogram demonstrates that Ni-doped LiNi_0.05Fe_0.95PO₄/C electrode has more stable lattice structure, enhanced conductivity, and diffusion coefficient of Li⁺ ions, in which Ni²⁺ is regarded to act as a column in crystal lattice structure to prevent the collapse during cycling process.     

Photophysical, photochemical and BSA binding/BQ quenching properties of quaternizable coumarin containing water soluble zinc phthalocyanine complexes

The non-peripherally (np-QZnPc) and peripherally (p-QZnPc) tetrakis-[7-oxo-(3-[(2-diethylaminomethyliodide)ethyl)]-4-methylcoumarin]-phthalocyaninatozinc complexes have been prepared by quaternization of non-peripherally and peripherally tetrakis[7-oxo-(3-[(2-diethylamino)ethyl)]-methylcoumarin] phthalocyaninato zinc complexes with methyliodide in dimethylsulfoxide (DMSO). The new quaternized zinc phthalocyanine complex (np-QZnPc) has been characterized by elemental analysis, MALDI-TOF, IR and UV-vis spectral data. The photophysical and photochemical properties of the peripherally and non-peripherally quaternized tetrakis-3-[(2-diethylamino)ethyl]-7-oxo-4-methylcoumarin substituted zinc phthalocyanines are reported. The effects of the position of the substituents and the aggregation of the phthalocyanine molecules on the photophysical and photochemical properties are also investigated. General trends are described for photodegradation, singlet oxygen and fluorescence quantum yields, and fluorescence lifetimes for complexes np-ZnPc/p-ZnPc in DMSO and for complexes np-QZnPc/p-QZnPc in DMSO, phosphate buffered solution (PBS) and PBS+Triton-X 100 solutions. The fluorescence of the tetra-substituted quaternized zinc phthalocyanine complexes (np-QZnPc/p-QZnPc) are effectively quenched addition of 1,4-benzoquinone (BQ) and this study also presented the ionic zinc phthalocyanine complexes strongly bind to bovine serum albumin (BSA).     

Chromenone 12-crown-4 substituted zinc phthalocyanine complexes: investigation of spectral, photophysical and photochemical properties

The synthesis of novel 6,7-[(12-crown-4)-3-[p-(3,4-dicyanophenoxy)phenyl]coumarin (1), 6,7-[(12-crown-4)-3-[p-(2,3-dicyanophenoxy)phenyl]coumarin (2), and their corresponding tetra-(chromenone 12-crown-4)-substituted zinc (II) phthalocyanine complexes (3 and 4) have been prepared. These new compounds have been characterized by elementel analysis, (1)H NMR (1 and 2), MALDI-TOF, IR and UV-Vis spectral data. The fluorescence intensity changes for 1 and 2 by addition of Na(+) or K(+) ions have been determined at 25°C in THF. Intensity of the binding Na(+)- and K(+)-complexes (1 and 2) have decreased. The effects of the chromenone crown ether on the phthalocyanine molecule concerning photophysical and photochemical properties are also investigated. Photodegredation, singlet oxygen, fluorescence quantum yields, and fluorescence lifetimes of zinc phthalocyanine complexes (3 and 4) are also examined in DMSO.     

利用荷移反应分光光度法测定注射液中的盐酸利多卡因

采用分光光度法研究了电子受体2,3-二氯-5,6-二氰基-1,4-对苯醌(DDBQ)与电子供体利多卡因(LD)的荷移反应,发现DDBQ与LD在乙腈中生成稳定的离子缔合物,并通过Job's plot确定DDBQ和LD的摩尔比为1:1.LD与DDBQ在587nm处形成强特征吸收峰.据此建立了一种测定注射液中LD含量的荷移分...     

Dynamic bidding strategies in search-based advertising

Search-based advertising allows the advertisers to run special campaigns targeted to different groups of potential consumers at low costs. Google, Yahoo and Microsoft advertising programs allow the advertisers to bid for an ad position on the result page of a user’s query when the user searches for a keyword that the advertiser relates to its products or services. The expected revenue generated by the ad depends on the ad position, and the ad positions of the advertisers are concurrently determined after an instantaneous auction based on the bids of the advertisers. The advertisers are charged only when their ads are clicked by the users. To avoid excessive ad expenditures due to sudden surges in the keyword-search activities, each advertiser reserves a fixed finite daily budget, and the ads are not shown in the remainder of the day when the budget is depleted. Arrival times of keyword-search instances, ad positions, ad selections, and sales generated by the ads are random. Therefore, an advertiser faces a dynamic stochastic total net revenue optimization problem subject to a strict budget constraint. Here we formulate and solve this problem using dynamic programming. We show that there is always an optimal dynamic bidding policy. We describe an iterative numerical approximation algorithm that uniformly converges to the optimal solution at an exponential rate of the number of iterations. We illustrate the algorithm on numerical examples. Because dynamic programing calculations of the optimal bidding policies are computationally demanding, we also propose both static and dynamic alternative bidding policies. We numerically compare the performances of optimal and alternative bidding policies by systematically changing each input parameter. The relative percentage total net revenue losses of the alternative bidding policies increases with the budget loading, but were never more than 3.5 % of maximum expected total net revenue. The best alternative to the optimal bidding policy turned out to be a static greedy bidding policy. Finally, statistical estimation of the model parameters is visited.