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Objective: To study the correlation of serum vitamin C content with renal anemia, oxidative stress and microinflammatory state in patients with peritoneal dialysis. Methods: A total of 96 patients undergoing peritoneal dialysis in the First Affiliated Hospital of Soochow University between January 2016 and January 2017 were selected as the peritoneal dialysis group, and 50 healthy volunteers receiving physical examination in the First Affiliated Hospital of Soochow University during the same period were selected as the normal control group. The contents of VitC as well as renal anemia, oxidative stress and microinflammation-related indexes in peripheral blood of two groups of subjects were detected, and Pearson test was used to evaluate the correlation of serum VitC content with renal anemia, oxidative stress and microinflammatory state in patients with peritoneal dialysis. Results: VitC content in peripheral blood of peritoneal dialysis group was lower than that of normal control group; renal anemia-related indexes Hb, RBC and TIBC levels in peripheral blood were lower than those of normal control group; oxidative stress indexes LHP, MPO and AOPPs contents in serum were higher than those of control group while SOD and GSH-Px contents were lower than those of control group; inflammatory factors CRP, IL-6, IL-8, IL-10 and IL-13 contents in serum were higher than those of normal control group. VitC content in serum of patients with peritoneal dialysis was positively correlated with Hb, RBC, TIBC, SOD and GSH-Px levels, and negatively correlated with LHP, MPO, AOPPs, CRP, IL-6, IL-8, IL-10 and IL-13 contents. Conclusion: Serum VitC content is lower in patients with peritoneal dialysis, and the specific content is directly correlated with the severity of renal anemia, oxidative stress and microinflammatory state.

Objective: Microangiopathy is common after a long duration in type 1 diabetes mellitus (T1DM). Pregnancies with end-age vascular complications are a big challenge to multidisciplinary physicians. The objective of this study was to assess the risk of microangiopathy for adverse pregnancy outcome in T1DM. Materials and Methods: PubMed, EMBASE, and Cochrane Library databases were searched for relevant articles appearing in the literature up to October 1, 2017. Analysis of cohort studies were performed with Review Manager 5.3 and Newcastle Ottawa Scale (NOS) was chosen to evaluate the risk of bias. Results: A total of 10 studies involving 3239 pregnancies were retrieved and analyzed. Microangiopathy for diabetic nephropathy (DN), microalbuminuria and diabetic retinopathy (DR) significantly increased the risk of preeclampsia (PE) (OR of 7.19, [95%CI: 5.15, 10.03], 4.19, [95%CI: 2.78, 6.31] and 3.02, [95%CI: 2.24, 4.07], respectively). Significant association of the presence of DN with preterm delivery was demonstrated (OR = 4.14, 95%CI [2.84, 6.02]), with small for gestation age was demonstrated (OR = 6.23, 95%CI [2.75, 14.14]) and with large for gestation age was demonstrated (OR = 0.41, 95%CI [0.27, 0.62]). A mild association of the presence of DR with preterm delivery was demonstrated (OR = 1.57, 95%CI [1.08, 2.29]). Conclusion: The presence of microangiopathy before or in early pregnancy increased the risk of adverse pregnancy outcome in T1DM. We highlighted it was important that White's classification and a full assessment of vasculopathy should be carry out before pregnancy to ensure a well-planned pregnancy. Further work should be designed to establish risks model involving microangiopathy and find out whether early intervention with strict blood sugar control or medication such as low-dose aspirin will reduce the incidence of PE in T1DM. Keywords: Diabetes mellitus, Type 1, Microangiopathy, Pregnancy outcome, Pre-eclampsia

(1R,2R,3S,4R,7R)-7-Isopropyl-6-methylbicyclo[2.2.2]oct-5-ene-2,3-dicarboxylic acid anhydride (tetrahydro-4,7-ethanoisobenzofuran-1,3-dione derivative) adduct 2 was prepared via the isomerization of α-pinene and β-pinene in turpentine followed by the Diels-Alder cycloaddition with maleic anhydride in the presence of phosphoric acid/iodine catalysis. The molecular structure of adduct 2 was characterized by IR, 1H NMR, 13C NMR, 1H-1H COSY, DEPT, HSQC, HMBC, 2D NOESY and MS spectra. The single crystal X-ray crystallographic analysis of adduct 2 was performed, and the X-ray powder diffractive spectrum of the sample adduct 2 is consistent with the diffractive spectrum calculated from the single crystal data. Therefore the structure and stereochemistry of adduct 2 was established based on extensive spectral data and single crystal X-ray analysis.

Objectives To develop and evaluate the self-management scale for peritoneal dialysis (PD) patients. Methods The item pool was formulated based on literature reviews and in-depth interviews. An initial scale containing five factors and 44 items was constructed through two rounds of Delphi expert consultation and a preliminary test. A total of 313 PD patients from the Jiangsu-Zhejiang-Shanghai area were surveyed to test the reliability and validity of the scale. Results Five factors, namely solution bag replacement, troubleshooting during operation, diet management, complication monitoring, emotion management and return to social life, were extracted by exploratory factor analysis: the 28 items could explain 64.567% of the total variance; the content validity index was 0.963; the Cronbach's α coefficient and split-half coefficient were 0.926 and 0.960 respectively; and test-retest reliability was 0.937. Conclusion The scale has been proved to be a reliable and valid tool which allows PD nurses to evaluate the self-management ability of PD patients. The evaluation outcomes can serve as a basis for individualized nursing plans and interventions so as to provide highly effective nursing care.

The high pure hindered amine with methaerylate (2,2,6,6-tetramethylpiperidin-4-yl methacrylate) 4 was synthesized by a condensation reaction of 2,2,6,6-tetramethylpiperidin-4-ol and methacrylic anhydride via isolation of the salt (1:1) of 4 and methacrylic acid in an improved yield (total 80%). The structure of the salt 4 of hindered amine was demonstrated by X-ray crystallographic analysis.

A series of optical polymeres were prepared by a Mitsunobu reaction from the correspondingN,N-dihydroxyethyl D-π-A chromophores and bisphenol A, which is new main-chain copolymeres with good solubility in ordinary organic solvents. The linear and nonlinear optical (NLO) properties were investigated by UV spectra and NLO measurements. The results indicate that the films of copolymeres exhibit a higher macroscopic second nonlinear optical coefficient, thermal stability and good optical transparency.

An aminoethoxy-functionalized zirconium phosphonate (Zr(O3POCH2CH2NH2)2·3H2O), abbreviated as ZrRP (R=OCH2CH2NH2), with layered structure has been synthesized. This layered compound possesses the characteristic of inorganic–organic hybrid, due to the covalently linked aminoethoxy in the host layer. The anion exchanged property of this zirconium phosphonate is suitable for the direct intercalation of negatively charged DNA, which is different from these reported zirconium phosphates or zirconium phosphonates. As a precursor, this prepared zirconium phosphonate was utilized to fabricate a novel DNA/ZrRP binary hybrid via a delamination-reassembly procedure. The release behavior of DNA from the DNA/ZrRP composite was investigated at different medium pH, because the combination between zirconium phosphonate sheets and DNA was pH-dependent sensitively. Moreover, the helical conformation of DNA was almost retained after the intercalation and release process. These properties of the DNA/ZrRP composite suggested the potential application of layered zirconium phosphonate as a non-viral vector in gene delivery.

New metal-free DNA cleaving reagent 1, 1,4,7-triazacrown (TACN) both with aminoethyl, hydroxyethyl side arms and a planar anthraquinone linked by an alkyl (1,6-hexamethylene) spacer has been synthesized and characterized by NMR and MS spectrometry. For comparison, the corresponding aminoethyl, hydroxyethyl triazacrown derivative 2 without the anthraquinone has also been synthesized. DNA-binding properties via fluorescence and CD spectroscopy indicate that the binding affinity of 1 with DNA is much stronger than that of 2. Agarose gel electrophoresis was used to assess plasmid pUC19 DNA cleavage. Kinetic data of DNA cleavage promoted by 1, 2 and parent triazacrown (TACN) 3 under physiological condition give the 15-fold and 234-fold rate acceleration of compound 1 over 2 and parent triazacrown 3. Radical scavenger inhibition study suggests that DNA cleavage promoted by 1 may be a non-oxidative pathway through the transphosphorylation and then hydrolysis. The dramatic rate acceleration is due not only to the anthraquinone moiety of compound 1 intercalating into DNA base pairs via stacking interaction, but also the cooperative catalysis of the nucleophilic hydroxyl and the electrophilic ammonium group for the cleavage of phosphodiester of DNA.

Combretastatins-A4 (CA-4) is a natural product with anticancer activity. However, only the cis-isomer exhibits strong antitubulin activity, but the cis-isomer tends to isomerize to the inactive trans-isomer. Thus, this paper reports that an additional pyrrolidone ring was used to replace the cis double bond to arrest the cis-conformation, and a series of 3,4-diaryl pyrrolediones and 3,4-diaryl pyrrolones as CA-4 analogues were synthesized via a four steps reaction from 3,4-dimethoxyacetophenone and 3-fluoro-4-methoxy acetophenone. The structure of the new compounds was confirmed by 1H NMR, 13C NMR, ESI-MS and elemental analysis. The in vitro activities of CA-4 analogues against HL-60, SMMC-7721 and A549 human cancer cell lines were tested using colorimetric MTT assay and the results indicate that they show significant antitumor activity.

Heart failure due to volume overload is a major reason for rehospitalization in continuous ambulatory peritoneal dialysis patients. Strict volume control provides better cardiac functions and blood pressure in this population. Volume management, which is a volume control strategy, may decrease volume overload and related complications. Using a quasi-experimental design, 66 continuous ambulatory peritoneal dialysis patients were randomly assigned to the intervention group ( n = 34) and control group ( n = 32). The patients were followed up for 6 months with scheduled clinic and/or telephone visits; the intervention group adopted volume management strategy, while the control group adopted conventional care. Volume overload and cardiac function were compared between the two groups at the baseline and at 6 months. At Month 6, the intervention group resulted in significant improvement in volume overloaded status, cardiac function, and volume-overload-related rehospitalization. Volume management strategy allows for better control of volume overload and is associated with fewer volume-related readmissions.

A novel octupolar chromophore with 1,3,5-triazine as core, 2,7-divinylene-9,9-dimethylfluorene as extended π-conjugated bridge, triarylamine as the electron-donating end-groups was successfully synthesized and characterized. Their linear photophysical and two-photon absorption (TPA) properties were investigated by UV absorption, excited fluorescence (SPEF) spectra and nonlinear transmission method, respectively. The absorption cut-off of the chromophore is below 520 nm and it has stronger fluorescence emission in a nonpolar solvent. In addition, the chromophore exhibits larger TPA cross-section (226.0 GM) in the femtosecond regime at 800 nm.

A series of H-shaped chromophores with two parallel and non-conjugated D-π-A units have been synthesized, in which a 9,10-dihydroanthracene was employed as molecular backbone. The synthesis of these H-shaped chromophores 9a–11a was accomplished via an eight-step reaction, including double Claisen rearrangement, hydroboration–oxidation, Rieche formylation reaction, Knoevenagel condensation and Corey–Fuchs reaction, with a total yield about 12.5%. The corresponding mono-D-π-A unit compounds 9b–11b were also prepared in a similar procedure for the purpose of comparison. Crystal structures of three intermediates 5a, 7a and 8a were measured, which demonstrate that the two D-π-A units in a single H-shaped chromophore molecule are nearly arranged at the same direction. The studies of UV–vis spectra and the solvatochromic method indicate that the molecular second-order polarizabilities values (μβ) of H-shaped chromophores are remarkably increased compared with the corresponding mono-D-π-A unit reference compounds, without causing a large shift of the absorption band to longer wavelength.

The different DNA cleavage behaviors of 1,3- and 1,4-xylylene spaced bisCu(BPA)Cl2 complexes (BPA, bis(pyridyl-2-methyl)amine) display the positioning effect of xylylene spacers, implying the essential roles of spacers in the related cleavage (Y. Zhao et al., Chem.–Eur. J., 2006, 12, 6621–6629). Herein, a p-xylyl derivative (2,1,3-benzoxadiazole-4,7-dimethylene (BDDM)) was utilized as a bulky spacer to construct a new p-xylyl spaced bisCu(BPA)Cl2 complex 1 to explore the spacer's steric effect on the related DNA cleavage. Agarose gel electrophoresis demonstrated that complex 1 is able to convert the supercoiled plasmid pUC19 DNA into the nicked DNA and linear DNA in the presence of excessive reductant. This DNA cleavage behavior is different from that of simple p-xylylene spaced Cu2(pTPXA)Cl4, which mediates only the nicked DNA and random DNA fragments. The DNA binding ability of complex 1 is higher than that of Cu2(pTPXA)Cl4, while its DNA nicking ability is lower than that of Cu(BPA)Cl2, as well as the dinuclear Cu2(pTPXA)Cl4, which displays a high DNA nicking efficiency due to the internuclear synergy in activating O2 to damage DNA. The linear DNA formation induced by complex 1 is realized via a non-random double-stranded scission process. The temporal profiles of the nicked DNA and linear DNA in the presence of 8 μM complex 1 imply that the two sequential neighboring breaks in the complementary strands lead to the formation of linear DNA. With the DNA cleavage behavior in the presence of different reactive oxygen species (ROS) quenchers, the DNA-bound hydroxyl radical was proposed as the main ROS involved in the cleavage. Structural optimization of this complex disclosed its larger intramolecular Cu–Cu distance than Cu2(pTPXA)Cl4, which may disfavor the internuclear synergic O2 activation. It was also proposed that the bulky BDDM spacer favors the two spaced copper centers function solely to damage in situ the two adjacent deoxyriboses from complementary strands to form the linear DNA, and the specific DNA binding mode of complex 1 due to the BDDM spacer disfavors the DNA-bound ROS to abstract a proton from deoxyribose and results in a lower DNA cleavage efficiency than mononuclear Cu(BPA)Cl2. The non-random linear DNA mediating ability and the decreased DNA cleavage efficiency caused by the bulky internuclear spacer shown in the current study provides a new alternative to regulate the DNA cleavage behavior of polycopper artificial nucleases via spacer modification.

A series of new fluoro-containing copolymers have been synthesized by a Mitsunobu reaction with 4,4′-(hexafluoro- isopropylidene)bisphenol A (6FBPA) and the corresponding N, N-dihydroxyethylaminoaryl azo or ring-locked triene compounds, which have high thermal stability and good solubility in organic solvents. The nonlinear optical (NLO) measurements made by Marker fringe method at 1064 nm indicate that the copolymers embedded with the ring-locked triene and azo chromophores exhibit higher macroscopic nonlinear optical coefficient (70.2 pm/V and 26.5–34.6 pm/V, respectively). Thermal analysis and UV–visible absorption spectra show that the copolymers have good thermal stability (Td = 264–319 °C) and optical transparency (λmax

Three two-photon absorption (TPA) tribranched chromophores were successfully prepared, in which 1,3,5-triazine is been as electron deficient core, 1,4-phenylenedivinylene as conjugated bridge, 3,4-ethylenedioxythiophene (EDOT) (T1), N-methylpyrrole (T2) or triphenylamine (T3) as electron-donating end-groups. Their photophysical properties were studied by absorption, one- and two-photon fluorescence and TPA cross-section determination. The nonlinear transmission (NLT) measurement in femtoseconds (fs) regime at 800 nm indicates that TPA cross-section (2 values of T1, T2 and T3 with extended Π-conjugated bridge are much larger than the corresponding chromophore T4 with a short length bridge, and TPA cross-section of T1 with end-groups EDOT exhibits a remarkable enhancement compared with T2 and T3 having the same length Π-system. The chromophores T1, T2 and T3 show also remarkable up-converted luminescence and optical limiting activity.

A novel calix[4]arene chromophore 1 was synthesized by introduction of two D-π-A units (4-nitrophenyl)azophenyloxy groups) on the lower rim of calix[4]arene. The measurement results of hyper-Rayleigh scattering (HRS) and UV-vis spectra show that the static first molecular hyperpolarizability of the chromophore 1 is more than two times that of the corresponding mono-D-π-A unit reference compound 4-(4-nitrophenylazo)phenol 2, without causing red-shift of absorption band.

The octupolar chromophore TA with a 1,3,5-triazine core and pyrrole electron-donating end-groups was prepared via Knoevenagel coupling. Its photophysical and two-photon absorption (TPA) properties upon the protonation with CF 3 COOH were investigated by absorption, fluorescence, NMR spectroscopy and TPA cross-section determination. The UV–vis spectroscopic study shows that the absorption band is shifted from 401 nm to 471 nm with the color change from pale-yellow to red upon CF 3 COOH addition. The fluorescence spectra shows that the emission band is red-shifted from 490 nm to 553 nm accompanied by the distinct emission quench effect caused by the protonation. NMR spectropic study demonstrates the protonation of triazine upon CF 3 COOH addition, and the protonated molecule retain the C 3h symmetry. In addition, the theoretical calculations of the absorption spectra of neutral and protonated TA demonstrate an obvious red-shift of λ max in the absorption after protonation. TPA cross-section of TA measured by nonlinear transmission (NLT) exhibits the obvious TPA cross-section enhancement effect upon protonation, provides a simple way to enhance the TPA cross-section of molecules and makes it attractive for application involving the proton-controlled optical sensor.

The nonlinear optical properties of an azo-based dye were investigated using Z-scan technique employing 38 ps pulses at 532 and 1064 nm, and 6 ns laser pulses at 532 nm. Large nonlinear absorption and nonlinear refraction were observed at both ps and ns 532 nm in the azoic dye. When excited at ps 1064 nm, this dye displayed a large two-photon absorption cross-section ( σ 2 =1810 GM). Meanwhile, the optical nonlinearity mechanism was discussed in terms of molecular structure, excitation wavelength, and pulse width.

A pair of artificial enantiotopic receptors la and lb composed of (S,S) or (R,R) chiral bicyclic guanidinium, azacrown ether and (t-butyldiphenylsilyloxy) methyl group for amino acid zwitterions have been synthesized. The liquid-liquid competition experiments and 1 H NMR studies indicate that the receptor 1a with (S, S) configuration and 1b with (R,R) configuration selectively recognize L- and D-aromatic amino acids & respectively.

A novel bis(guanidiniums) receptor for the catalytic cleavage of phosphosdiester was prepared and self-assembly architecture through hydrogen bonds and electrostatic interactions among the bis(guanidiniums) receptor, the sulfate anion and water molecule was revealed by X-ray crystallographic analysis.

The novel calix [4] crowns with two pendant groups were prepared by the alkylation of calix [4] crowns with 6-methoxy-2-bromoacetylnaphthalene. 1H NMR titration and picrate extraction experiments indicated that they exhibit higher complexing efficiency than their parent compounds and possess obvious selectivity for Na+ or K+, respectively, and that the cation is encapsulated inside the preorganized ionophoric cavity defined by carbonyl oxygens, the crown ether and the phenoxy oxygens. From UV and fluorescent spectra it is revealed that calix [4]-crown-4 3a with 6-methoxy-2-naphthoylmethyl pedant groups exhibits remarkable cation-induced photophysical effects and it could be utilized as a selective fluorescent sensor for Ca2+.

The p-tetra-tert-butyl calix[4] arene derivatives (3 and 4) with (5,5) chiral bicyclic guanidinium, as the receptors of amino acid zwitterions, have been synthesized via a O-alkylation reaction of p-tetra-tert-butyl calix [4] arene with cbJoromethyl chiral bicyclic guanidinium 2 in the presence of anhydrous K2CO3 in acetonitrile. The results obtained from liquid-liquid competitive extraction experiments indicate that the two receptors may selectively recognize L-aromatic amino acids, and that the enantioselective recognizability of the receptor 4 with two chiral bicyclic guanidinium units reachs up to about 90% for L-Phe.

Ibis paper reports the properties of the novel tetra-p-nitro-tetra-O-alkyl-calix[4]arenes (alkyl= n-C4H9, 1; n-C8H17 2; n-C12H25, 3; n-C16H33, 4). X-ray crystallographic analysis and 1H NMR revealed that they exist as pinched-cone conformation in crystal or cone conformation in solution. EFISH experiments at 1064 nm in CHCl3, indicated that tetra-p-nitro-tetra-O-butyl-calix[4]arene (1) has higher hyperpolarizability β, values than the corresponding reference compound p-nitro-phenyl butyl ether, without red shift of the charge transfer band. Compounds 2, 3 and 4 with longer alkyl chains can form monolayer at the air/water.

Five novel azo calix[4]arenes were reported. The p-aminobenzaldehyde was diazotized with sodium nitrite in aqueous hydrochloride solution. Mono-, bis-, his- and tetrakis(p-formylphenyl)azo calix[4]arenes (including proximal and distal isomers) were obtained respectively by diazo-coupling in different molar ratio to calix[4]arene (1) under pH=7.5-8.5 at 0-5 C. All (p-formylphenyl)azo calix[4]arenes were characterized by 'H NMR, 13C NMR, IR, MS (ESIMS) spectroscopies and elemental analysis.

A novel method for the preparation of chromogenic calixarenes with azo groups was reported. p-Substituted (- NO2, - CH3, - Cl) anilines were diazotized with isoamyl nitrite in EtONa/EtOH under refluxing condition. Fifteen mono-, bis-, tris- and tetrakis(p-substituted phenyl)azo calix[4]arenes (including proximal and distal isomers) were obtained respectively by diazo-coupling in different molar ratio to calix[4]arenes (1) under pH = 7.5–9.0 in non-aqueous solution at 0-5 °C. 1H NMR anduC NMR spectra of (α-substituted phenyl)azo calix[4]-arenes Indicated that they existed in cone conformation in solution.

A novel mediator-free biosensor was constructed by the co-intercalation of negatively charged DNA and positively charged hemoglobin (Hb) in the interlayer galleries of layered alpha-zirconium phosphate (alpha-ZrP) with the delamination-assembly procedure at pH 5.5. X-ray diffraction and field-emission scanning electron microscopy results revealed the featured layered structure for the re-assembled DNA/Hb/alpha-ZrP composite. Infrared spectroscopy and circular dichroism results confirmed the coexistence of Hb and DNA in the composite and the considerably retained protein conformation of intercalated Hb. The direct electron transfer of Hb was facilitated by the co-intercalation of DNA and Hb. Because of the synergistic effect of alpha-ZrP host and co-intercalated DNA guest, the DNA/Hb/alpha-ZrP modified electrode exhibited good electrocatalytic response to H(2)O(2) with higher sensitivity of 0.79 A M(-1) cm(-2) and lower detection of 4.28x10(-7) M in the linear range of 7.28x10(-7) to 9.71x10(-5) M. Furthermore, the electrocatalytic activity of Hb in the DNA/Hb/alpha-ZrP composite retained at high temperature (85 degrees C) or in the presence of organic solvent (CH(3)CN), which could be the protection of alpha-ZrP nanosheets.

The macroscopic second harmonic generation (SHG) coefficient (d33) of polymer depends on several factors, including the first hyperpolarizability (β) and dipole moment (μ) of chromophore, the combination of different donors (D) and acceptors (A), chromophore–chromophore electrostatic interactions, asymmetric structure of chromophore, the effect of main-chain on NLO properties of polymer, hydrogen bond and so on, therefore, several parameters should be comprehensively considered to design desired materials with high d33 value. Based on quantum chemical calculations, a polyimide containing isophorone derivatives as chromophores were designed and synthesized. Experimental results show that the polyimide exhibits a large macroscopic nonlinear optical coefficient (d33 = 63.9 pm V−1), thermal stability (Tg = 171 °C; Td = 308 °C) and good optical transparency (λmax = 418 nm). This paper could suggest a potentially practical way for designing effective NLO polymers.

Chromophores containing two parallel nonconjugated D-pi-A units are effective chromophores with high hyperpolarizability and good optical transparency. It provides a method for the design and synthesis of effective chromophores. The semiempirical method ZINDO was employed to study the relationship between enhancement of the static first hyperpolarizabilities (beta0) per D-pi-A unit and the number of parallel nonconjugated D-pi-A units in a chromophore. The results show that the chromophores containing two parallel nonconjugated D-pi-A units would exhibit higher beta0 values than two times the beta0 value of the corresponding reference chromophore containing a D-pi-A unit. The chromophore containing three parallel nonconjugated D-pi-A units exhibits the highest enhancement of beta0 per D-pi-A unit, which is 10.1 times the beta0 value of the corresponding reference chromophore. However, the beta0 value of the chromophore containing four parallel nonconjugated D-pi-A units is very small, and the enhancement of beta0 value per D-pi-A unit decreases sharply, from 10.1 to 0.3, with increasing the number of parallel D-pi-A units in a chromophore from 3 to 4. It could give a useful suggestion for designing chromophores containing parallel nonconjugated D-pi-A units.

The interaction of zinc(II) complex of N,N′-bis(guanidinoethyl)-2,6-pyridinedicarboxamide (Gua) with DNA was studied by CD spectroscopy and agarose gel electrophoresis analysis. The results indicate that the DNA binding affinity of Zn2+-Gua is stronger than that of Gua and the Zn2+-Gua can promote the cleavage of phosphodiester bond of supercoiled DNA under a physiological condition, which is ∼106 times higher than DNA natural degradation. The hydrolysis pathway was proposed as the possible mechanism for DNA cleavage promoted by the Zn2+- Gua. The acceleration is due to cooperative catalysis of the zinc cation center and the functional groups (bisguanidinium groups).

The nonlinear optical properties and photoinduced anisotropy of a novel stilbene-containing fluorinated polyimide were investigated. Large macroscopic second-order optical nonlinearity (d33 = 35.4 pm/V) was obtained in a poled thin film using the Maker fringe method. A nonlinear absorption coefficient (β) of 0.65 × 10−5 cm/W and third-order nonlinear refractive index (n2) of −1.13 × 10−10 cm2/W were determined by Z-scan measurements. Photoinduced birefringence (Δn) of 1.02 × 10−2 was observed using a continuous Nd:YAG laser at 532 nm as pump light and a continuous diode laser at 650 nm as probe light.

The design of artificial nucleases and nuclease mimics has attracted extensive attention and made great progress due to their significant scientific meanings and potential application in the field of gene medicine and molecular biology. This paper reviews recent progress in the investigation of artificial nuclease, including “bifunctional cooperative catalysis”, “dinuclear synergistic catalysis”, “metal-free catalysis”, and especially, the studies of aza-crown ethers as artificial nucleases and their interaction with DNA.

A novel azobenzene-containing fluorinated polyimide was synthesized. The nonlinear optical property and photoinduced birefringence of a polyimide thin film were investigated. Large third-order nonlinear refraction (n 2=−4.49×10−11 cm2/W) was observed in the polyimide thin film by carrying out Z-scan measurement. The polyimide thin film exhibited larger nonlinear refraction than that of a mono-azo dye doped PMMA thin film (n 2=−1.63×10−12 cm2/W). The photoinduced birefringence of the polyimide thin film (▵ n∼10−2) under different pump intensities was investigated; it was much larger than that of the mono-azo dye doped PMMA thin film (▵ n∼10−3). Moreover, the time constants for birefringence growth and relaxation processes were determined.

Novel cleft molecule pyridine-2,6-dicarboxamide appending two guanidinoethyl group side arms (Gua) was synthesized. The interactions of the cleft molecule in the absence of copper(II) (Gua) or in the presence of copper(II) (Cu2+-Gua) with calf thymus DNA were studied by fluorescence and CD spectroscopy. The results indicate that the DNA binding affinity of Cu2+-Gua is stronger than that of Gua, and the binding constants of Cu2+-Gua and Gua are 1.61 x 10(6) M(-1) and 2.86 x 10(5) M(-1), respectively. Agarose gel electrophoresis was used to assess the plasmid pUC 19 DNA cleavage activities in the presence of Gua and Cu2+-Gua. Kinetic data of DNA cleavage promoted by Cu2+-Gua under physiological conditions fit a saturation kinetic profile with k(max) of 0.0173 +/- 0.0011 h(-1), which gave a aproximately 10(6)-fold rate acceleration over uncatalyzed supercoiled DNA, while the catalyst concentration is lower than 0.0625 mM. The hydrolysis pathway was proposed as the possible mechanism for DNA cleavage promoted by Cu2+-Gua. The acceleration is due to efficient cooperative catalysis of the copper cation center and the functional groups (bis(guanidinium) groups).

Two new azo-dye chromophores containing different electron-acceptor groups were synthesized and characterized by 1 H NMR, FT-IR and UV-vis spectra, respectively. The second-order nonlinearity of azo-dyes doped films in poly (methylmethacrylate) and the first hyperpolarizability of the azo molecules were investigated by the Maker Fringe method and the solvatochromic method, respectively. Experimental results showed that both of the two dyes exhibited large second-order nonlinearity (d33 > 30 pm/v) and the stronger electron-acceptor groups in dye molecules would induce larger second-order nonlinearity. This was confirmed by the measurement of the first hyperpolarizability.

A series of H-shaped second-order nonlinear optical (NLO) chromophores with two parallel and nonconjugated D−π−A units have been synthesized, in which a 9,10-dihydroanthracene is employed as molecular backbone. The measurement results of hyper-Rayleigh scattering (HRS) and UV−vis spectra show that the first molecular hyperpolarizability (β) values of H-shaped chromophores are remarkably increased compared with the corresponding mono-D−π−A unit reference compounds (the enhancements per azo D−π−A unit from 1.2 to 3.0 are observed), without causing a large shift of the absorption band to longer wavelength. Therefore, it gives an available way of solving the trade-off between nonlinearity and transparency in designing NLO chromophores. Furthermore, some main-chain fluoro-containing polyimides embedded with the H-shaped chromophores have also been prepared. The elemental investigation results show that the polyimides exhibit a higher macroscopic nonlinear optical coefficient (d33 = 35.0 to ∼70.2 pm/V), good th...

Two series of fluorine-containing azo dyes containing hexafluoroisopropylidenebis-(4-hydroxybenzene) (B) or 4,4′-(hexafluoroisopropylidene)diphthalicimidine (C) as a backbone connecting the two D-π-A units were synthesized so as to investigate the effects of both the D-π-A units and backbones on the nonlinear optical (NLO) properties of the colourants. Hyper-Rayleigh scattering (HRS) at 1064 nm indicated that the β values of C-containing derivatives were higher than those of B-containing derivatives when the substituents were strongly electron-withdrawing groups. The first hyperpolarizability (β) and static first hyperpolarizability (β0) of the fluorine-containing dyes increased markedly when the difference between the Hammett constants (σ) [Hammett LP. J Am Chem Soc 1937;59:96. Hansch C, Leo A, Taft RW. Chem Rev 1991;91:165.] of the electron-withdrawing and electron-donating groups in the D-π-A units increased, especially when the electron-withdrawing groups in the D-π-A units were strong, such as in the case of nitro and cyan groups. In addition, UV–vis absorption maximum (λmax) of these fluorine-containing azoic dyes were not red shifted compared with the corresponding mono-D-π-A unit compounds.

The interaction of Cu2+ complex of N,N′-bis(2-aminoethyl)-2,6-pyridinedicarboxamide (BAP) with DNA was studied by agarose gel electrophoresis analysis. The results indicate that the BAP-Cu2+ complex can promote the cleavage of phosphodiester bond of supercoiled DNA at physiological condition, which is 3.2×106 times higher than DNA natural degradation. A hydrolytic cleaving mechanism through the cooperation of copper ions and functional amino groups was proposed.

The tetraazamacrocycle crown ether (cyclen) containing two pyridine subunits was prepared by a modified procedure and the interaction of its metal complexes with DNA was studied by agarose gel electrophoresis analysis. The results indicate that the Cu2+ complex as nuclease model can promote the hydrolysis of phosphodiester bond of supercoiled DNA. The rate of degradation of the supercoiled DNA (form I) to nicked DNA (form II) obtained at physiological condition in the presence of 2.14 mM Cu2+ complex is 2.31 × 10–3 min−1. The dependence of the rate of supercoiled DNA cleavage from the complex concentration shows an unusual profile and a hydrolytic cleaving mechanism of two monometallic complexes through cooperation from two-point binding to DNA is proposed.

The new chromophore compounds with NLO properties were prepared by Knoevenagel condensation from formyl or diformyl calix[4]arene and isophorone derivatives in the presence of piperidine and acetic acid, respectively. In these chromophore calix[4]arenes, the ring locked trienes were employed as the conjugation bridge and electron acceptor in D-π-A units. The NMR spectra demonstrated that they existed in a cone conformation and consequently non-conjugated D-π-A units could be oriented at nearly the same direction.

The mono, bis, tris and tetrakis (p-nitrophenyl)azo calix[4]arenes (1, 2, 3 and 4) with NLO properties are synthesized by the diazo-coupling of calix[4]arene with p-nitrophenyl diazonium. HRS measurements at 1064 nm indicate that (p-nitrophenyl)azo calix[4]arenes have higher second-order hyperpolarizability β values than the corresponding reference compound 4-(4-nitrophenylazo)-2,6-dimethylphenol, without red shift of the charge transfer band. The bis and tris (p-nitrophenyl)azo calix[4]arenes (2, 3) without hydrophobic alkyl chains can form stable Langmuri monolayers at the air/water interface because of arene π–π stacking.