Incorporation of DNA/PEI polyplexes into gelatin/chitosan hydrogel scaffolds: a μ-DSC study

Polyplexes between a double-stranded Salmon DNA and hyperbranched poly(ethyleneimine) (PEI) as well as a maltosylated PEI-Mal were incorporated into a gelatin/chitosan hydrogel scaffold. Calorimetric experiments of the polyplexes show a decrease of the melting temperature in presence of PEI and a peak splitting in presence of PEI-Mal, which can be interpreted to a partial compaction of the DNA strands in presence of PEI-Mal. When the polyplexes are incorporated into a gelatin/chitosan scaffold in the swollen state, the DNA melting peaks at 90 and 93 °C, respectively, indicate in both cases the release of the DNA at the surface of the hydrogel scaffold in a more compact form. Specific interactions between the PEI-Mal shell and gelatin are responsible for the tuning of the release properties in presence of the maltose units in the hyperbranched PEI.     

Design and performance of a composite Tm:YAG laser pumped by VBG-stabilized narrow-band laser diode

A 2-μm composite Tm:YAG laser pumped with a narrow-band laser diode was presented. The temperature distribution and thermal lens in the Tm:YAG were numerically simulated by a finite element method and the results were used to design the special cavity, in order to achieve a high efficiency and stable output. With a 25-W incident pump power, we obtained a maximum output power of 11 W at 2018.5 nm, corresponding to a slope efficiency of 51.3% and an optical-to-optical efficiency of 44.5%, respectively. The beam quality was measured to be M_x~2= 1.8 and M_y~2= 1.6.     

微晶硅n-i-p太阳电池中n型掺杂层对本征层结构特性的影响

采用高压射频等离子体增强化学气相沉积方法在非晶和微晶两种n型硅薄膜衬底上沉积了一系列不同厚度的本征微晶硅薄膜,研究了不同n型硅薄膜对本征微晶硅薄膜的表面形貌、晶化率和结晶取向等结构特性的影响.结果表明,本征微晶硅薄膜结构对n型掺杂层具有强烈的依赖作用,微晶n型掺杂层能够有效减少n/i界面非晶孵化层的厚度,改善本征微晶硅薄膜的纵向均匀性,进而提高微晶硅n-i-p太阳电池性能. 关键词： 孵化层 微晶硅薄膜 纵向均匀性 n-i-p太阳电池     

Yb^3+含量对掺Er^3+铝酸盐玻璃光谱性质的影响

采用高温熔融法制备百分比为(100-x)(23.6Al2O3-53CaO-7.7BaO-2.1Na2O-10.3Ga2O3-3.1B2O-0.2Er2O3)-xYb2O3(x=0,0.9,1.9,2.8,3.6,4.5)的铝酸盐玻璃。应用差示扫描量热法、吸收光谱、荧光光谱、红外光谱以及拉曼光谱等检测手段,系统研究了不同Yb^3+离子引入量对玻璃的物性、热稳定性、Er^3+离子光谱性质和结构的影响。结果表明,Yb2O3含量越高,玻璃的密度和折射率越大,抗析晶能力有所增强。随着Yb2O3的增加,玻璃在976 nm吸收系数增大,对应于Er^3+离子的2H11/2→4I15/2、4S3/2→4I15/2以及4F9/2→4I15/2跃迁的527,549,666 nm的上转换发光、红光与绿光发光强度比以及对应于4I13/2→4I15/2的1.53μm近红外荧光强度明显增加。当Yb2O3浓度为3.6%时,铝酸盐玻璃样品在近红外1.53μm荧光最强,此时Yb^3+→Er^3+正向能量传递效率η1最大,约为82.9%。该系列铝酸盐玻璃中Er3+离子1.53μm最大发射截面为0.77×10^-20 cm^2,荧光半高宽最大值为39.4 nm,荧光寿命最大值为4.46 ms。     

Catena-dichloro(4,4′-dimethyl-2,2′-bipyridine)Cadmium(Ⅱ),a New One-dimensional Chain with Blue Fluorescent Emission

A new μ-chloro-bridged one-dimensional coordination polymer Cd(dmbpy)Cl2n(dmbpy=4,4′-dimethyl-2,2′-bipyridine) has been synthesized and structurally characterized by elemental analyses=IR=UV spectra and single-crystal X-ray diffraction.The complex crystallizes in the monoclinic system=space group C2/c with a=17.745(4)=b=10.326(2)=c=7.3382(15)=β=106.85(3)o=V=1286.9(4)3=Z=4=C12H12N2Cl2Cd=Mr=367.54=Dc=1.897 g/cm3=F(000)=720=λ(MoKα)=0.71073=μ=2.089 mm-1=R=0.0368 and wR=0.1048 for 1041 observed reflections(I > 2σ(I)).Cadmium(II) adopts a distorted octahedral coordination geometry and adjacent coordination chains are intercalated in a zipper-like fashion into 2D layers through the π-π stacking interactions between dmbpy.Fluorescent     

The use of electrospray ionization tandem mass spectrometry on the structural characterization of novel asymmetric metallo-organic supermolecules,based on pentafluorophenylporphyrins and ruthenium complexes

The novel asymmetric metallo-organic triads cis- and trans-[B(4-py)BPFPH₂{Ru₃O(Ac)₆(py)₂}{Ru(bpy)₂Cl}](PF₆)₂ (5a,b) for which cis- and trans-B(4-py)BPFPH₂ = 5,10-bis(pentafluorophenyl)-15,20-bis(4-pyridyl)porphyrin and 5,15-bis(pentafluorophenyl)-10,20-bis(4-pyridyl)porphyrin, respectively; Ac = acetate; py = pyridine and bpy = 2,2′-bipyridine, as well as their corresponding monosubstituted dyads cis- and trans-[B(4-py)BPFPH₂{Ru₃O(Ac)₆(py)₂}]PF₆ (4a,b) have been structurally characterized via electrospray ionization mass spectrometry (ESI-MS and ESI-MS/MS). The ESI-MS of dyads 4a,b display two characteristic Ru-multicomponent clusters of isotopologue ions corresponding to singly charged ions 4a,b⁺ of m/z 1629 and doubly charged ions [4a,b+H]²⁺ of m/z 815 and the triads 5a,b are detected by ESI-MS as the intact doubly charged cluster of isotopologue ions of m/z 1039 [5a,b]²⁺. The ESI-MS/MS of 4a,b⁺, [4a,b+H]²⁺ and [5a,b]²⁺ reveal characteristic dissociation pathways, which confirm the structural assignments providing additional information on the intrinsic binding strengths of the gaseous ions. Although the gas-phase behavior of each pair of isomers was rather similar, the less symmetric dyads 4a,b are distinguished via the ¹H NMR spectral profile of the pyrrolic signals. Exploratory photophysical assays have shown that both modifying motifs alter the porphyrinic core emission profile, opening the possibility to use these asymmetric systems as photophysical devices.     

Counter-examples of regularity behavior for σ-evolution equations

In this paper, we mainly discuss the infinite loss of regularity and μ-loss for a σ-evolution type model with oscillating in time coefficients. On the one hand, an explicit counter-example has been constructed in the frequency space to show the precise infinite loss of regularity. On the other hand, due to the finite propagation speed property for σ∈(0,1], we construct the counter-example of a sequence of solutions in R by applying state of art techniques.     

WEIGHTED ESTIMATES FOR COMMUTATORS OF MULTILINEAR CALDERON-ZYGMUND OPERATORS WITH NON-DOUBLING MEASURES

Let μ be a nonnegative Radon measure on Rd, which only satisfies the polynomial growth condition. Under this assumption, the authors obtain some weighted weaktype estimates for the commutators generated by the multilinear CalderSn-Zygmund op- erators and RBMO（μ） functions.     

Synthesis,structure, and DNA-binding of a new binuclear copper(II) complex: [Cu2(heap)(H2O)2](pic)2 · 2H2O

In this study, a new μ-oxamido-bridged binuclear copper(II) complex [Cu₂(heap)(H₂O)₂](pic)₂ ? 2H₂O, where heap and pic stand for the anion of N,N′-bis(N-hydroxyethylaminopropyl)oxamide and 2,4,6-trinitrophenol, respectively, has been synthesized and characterized by elemental analyses, IR, UV, molar conductance, and single-crystal X-ray diffraction. The complex has an embedded inversion center at the middle of the C–C bond of the oxamido group. Each copper(II) is in a square-pyramidal coordination geometry. The bridging ligand (heap) adopts a bis-tetradentate trans conformation and the oxamido group is in an imidic acid configuration. Hydrogen bonds contribute to a 3-D supramolecular structure in the crystal. The interaction of the binuclear complex with herring sperm deoxyribonucleic acid (HS-DNA) has been investigated by using absorption and emission spectra, electrochemical techniques, and viscometry. The results suggest that the binuclear copper(II) complex interacts with HS-DNA by electrostatic interaction with intrinsic binding constant of 2.67 × 10⁴ (mol L^?1)^?1. The influence of anions on the structure and the interaction of the binuclear complex with HS-DNA were preliminarily discussed.