meso-2'-Linked porphyrin-BODIPY hybrids: synthesis and efficient excitation energy transfer.

Three meso-2'-linked porphyrin-BODIPY hybrids which contain one, two, and four BODIPY units (, , and ), respectively, were synthesized. Their photophysical properties were investigated by UV-vis and fluorescence spectroscopy, cyclic voltammetry, and femtosecond transient absorption spectroscopy, as well as by theoretical calculations. The electronic properties of the constituent chromophores were found to be largely retained in these hybrids. Meanwhile, efficient and rapid energy transfers from (1)* to were evaluated to be 1.2 × 10(11), 1.5 × 10(11), and 1.1 × 10(11) s(-1), respectively.

[Effects of Zhuang-medical thread moxibustion combined with needle-pricking on vascular oxidative stress injury in the rat].

OBJECTIVE: To observe the effect of Zhuang-medical thread moxibustion combined with needle-pricking on vascular oxidative stress injury in oxidative stress injury rats. METHODS: Eighty Wistar rats were randomly allocated to normal control, sham operation (sham), model, and combined treatment groups (n=20 in each group). The oxidative stress injury model was established by ligation of the left sciatic nerve to induce chronic constriction injury (CCI) pain stress stimulation. Zhuang-medical thread moxibustion was applied to bilateral "Zusanli" (ST 36), once a day for 3 weeks. Needle-pricking was applied to left "Yanglingquan" (GB 34) and left "Huantiao" (GB 30), once a day for 3 weeks except Sundays. Plasma 6-keto-PGF 1α, thromboxane B 2 (TXB 2), NO and ET contents were assayed by radioimmunoassay. COX-2 immunoactivity of the femoral artery was determined by immunohistochemistry, and pathological changes of the femoral artery were detected by H. E. staining. RESULTS: Compared with the control group, the levels of plasma 6-keto-PGF 1α and NO in the model group were significantly reduced (P<0.05), while those of plasma TXB 2 and ET and COX-2 expression in the femoral artery were obviously increased in the model group (P<0.01). After moxibustion plus needle-pricking treatment, CCI-induced decrease of plasma 6-keto-PGF 1α and NO contents, and increase of plasma TXB 2 and ET and COX-2 expression levels were obviously reversed (P<0.05, P<0.01). The tubal wall of the femoral artery in rats of the model group got thicker, while that of the combined treatment group was relatively thinner, suggesting an inhibition of vascular intimal hyperplasia after the treatment. CONCLUSION: Zhuang-medical thread moxibustion combined with needle-pricking of ST 36, GB 34 and GB 30 can reduce the expression of femoral artery COX-2 and regulate the balance of both plasma PGI 2/TXA 2 and plasma NO/ET in CCI-induced oxidative stress rats, which may contribute to its effect in suppressing oxidative stress-induced vascular intimal hyperplasia.

Benzo[a]carbazole-Based Donor-π-Acceptor Type Organic Dyes for Highly Efficient Dye-Sensitized Solar Cells.

A novel class of metal-free organic dyes based on benzo[a]carbazole have been designed, synthesized, and used in dye-sensitized solar cells for the first time. These types of dyes consisted of a cyanoacrylic acid moiety as the electron acceptor/anchoring group and different electron-rich spacers such as thiophene (JY21), furan (JY22), and oligothiophene (JY23) as the π-linkers. The photophysical, electrochemical, and photovoltaic properties, as well as theoretical calculations of these dyes were investigated. The photovoltaic performances of these dyes were found to be highly relevant to the π-conjugated linkers. In particular, dye JY23 exhibited a broad IPCE response with a photocurrent signal up to about 740 nm covering the most region of the UV-visible light. A DSSC based on JY23 showed the best photovoltaic performance with a Jsc of 14.8 mA cm(-2), a Voc of 744 mV, and a FF of 0.68, achieving a power conversion efficiency of 7.54% under standard AM 1.5 G irradiation.

A meso-meso directly linked porphyrin dimer-based double D-π-A sensitizer for efficient dye-sensitized solar cells.

A novel double D-π-A branched dye () was synthesized and applied as a sensitizer for DSSCs. exhibited broader and stronger light absorption capability than the single D-π-A dye (). In the meantime, the orthogonal conformation of was found to be favorable for impeding intermolecular aggregation. Consequently, a power conversion efficiency of 5.33% was achieved under AM 1.5G conditions.

Synthesis of directly fused porphyrin dimers through Fe(OTf)3-mediated oxidative coupling.

An efficient and general Fe(OTf)3-mediated oxidative coupling method was developed for the synthesis of doubly or triply linked porphyrin dimers. Besides the central metal and peripheral substituent, regioselectivity of the oxidative coupling was found to be closely relevant to the onset oxidation potential of the porphyrin substrate, and the reactant with higher E(onset(ox)) tends to generate meso-ß doubly fused porphyrin dimer.

Metal-free iodine(III)-promoted synthesis of isoquinolones.

A metal-free oxidative cycloaddition reaction of substituted benzamides and alkynes has been developed for the synthesis of isoquinolones by using bis(trifluoracetoxy)iodobenzene (PIFA) and trifluoroacetic acid (TFA). Under mild conditions, a wide variety of isoquinolones were conveniently prepared via oxidative annulation of simple N-methoxybenzamide and diarylacetylene or aryl/alkyl acetylene derivatives in yields up to 87%.

Switchable regioselectivity in the PIFA-BF3·Et2O mediated oxidative coupling of meso-brominated Ni(II) porphyrin.

A simple and efficient method has been developed for the switchable synthesis of directly linked meso-brominated Ni(II) porphyrin dimers through PIFA-BF3·Et2O mediated oxidative coupling. The respective syntheses of meso-meso or meso-ß singly, doubly, and triply linked porphyrin dimers can be easily realized with the same reagent system.

[Effects of needle pricking therapy of Zhuang minority medicine on expression of pulmonary T-bet, GATA-binding protein 3 genes and thymic stromal lymphopoietin protein in the lung of asthma mice].

OBJECTIVE: To observe the effect of needle pricking therapy on the expression of thymic stromal lymphopoietin (TSLP) protein, T-box expressed in T cells(T-bet)mRNA and GATA-binding protein-3 (GATA 3) mRNA in the lung tissue of mice with asthma, so as to explore its mechanism underlying improvement of asthma. METHODS: Thirty female BALB/c mice were randomly divided into control, model and needle pricking groups (10 mice/group). The asthma model was established by i. p. of Ovalbumin (OVA) suspension fluid (containing Aluminium Hydroxide 400 microg and OVA 100 microg, 50 microg/L) and forced inhalation of atomized OVA. A sharp needle was held to prick "Dazhui" (GV 14),"Feishu" (BL 13), "Dingchuan" (EX-B 1),"Fengmen" (BL 12),"Shenshu" (BL 23) and "Pishu" (BL 20) acupoint regions to let a little bit of white fibrous tissue out, then to insert into the acupoints to about 1 mm in depth, once a day for seven times. The lung tissue was taken for detecting the expression of T-bet mRNA and GATA-3 mRNA by RT-PCR and for determining the immunoactivity of TSLP by immunofluorescence method. In addition, HE staining was used to examine the pathologic changes of the lung tissue. RESULTS: Compared with the control group, the expression levels of GATA-3 mRNA and TSLP protein of the lung tissue in the model group were significantly increased (P < 0.01), whereas that of T-bet mRNA was remarkably decreased (P < 0.05). Following needle prick stimulation treatment, the expression levels of GATA-3 mRNA and TSLP protein were markedly down-regulated (P < 0.01) and that of T-bet mRNA was obviously upregulated (P < 0.05). After the treatment, pathological changes including hyperemia of the pulmonary alveoli, epithelial thickening, narrowing of the lumina, and infiltration of many inflammatory cells around the tracheal blood vessels were improved. CONCLUSION: Needle pricking therapy can regulate the expression of pulmonary TSLP protein and GATA 3 and T-bet genes in mice with asthma, which may contribute to its effect in improving pulmonary pathological changes of asthma mice.

Simple and catalyst-free synthesis of meso-O-, -S-, and -C-substituted porphyrins.

A simple and efficient method for the meso-functionalization of porphyrin has been developed. Kinetic studies of meso-fluoro-, -chloro-, -bromo-, -iodo-, and -nitro-substituted porphyrins (Ni) with phenol reveal that the reaction undergoes a typical aromatic nucleophilic substitution (SNAr) process. This catalyst-free method can be performed with meso-brominated porphyrins and oxygen-, sulfur-, and carbon-based nucleophiles to achieve a wide variety of meso-substituted porphyrins.

Clawlike tripodal porphyrin trimer: ion-controlled on­off fullerene binding.

A practical method for the preparation of novel tripodal tris(porphyrinato-urea) TP3 1 was readily achieved. Because of its appreciable preorganized triangular cone-shaped cavity resulting from the intramolecular hydrogen bonds of the tripodal tris-urea backbone, this porphyrin trimer host was found to have a high affinity toward fullerenes to form stable inclusion complexes in solution. A 120-fold binding selectivity toward C70 (Kassoc = 1.81 × 10(7) M(­1)) over C60 (Kassoc = 1.51 × 10(5) M(­1)) was further achieved in toluene. Moreover, the dissociation of such inclusion complexes can be easily realized by introducing H2PO4(­), and recapturing of the fullerene can be achieved after withdrawing H2PO4(­) by Ca(2+). A recyclable process for the inclusion and release of fullerene was therefore built by alternately feeding H2PO4(­) and Ca(2+). Benefiting from this approach, TP3 1 was sequentially applied to isolate C70 from the C60-enriched fullerene mixture successfully.

Widely tunable single-bandpass microwave photonic filter based on polarization processing of a nonsliced broadband optical source.

We propose a new scheme of microwave photonic filter (MPF) based on the polarization processing of a broadband optical source (BOS), which features single-bandpass response and a wide span of operation bandwidth. The BOS is orthogonally polarized by a polarization division multiplexing emulator (PDME) with a tunable time delay between the two polarization states and incident at ± 45° to one principle axis of a polarization modulator (PolM). The PDME cascades a PolM, and a polarizer realizes a microwave modulation making the phase of the carrier able to be tuned while ± 1st sidebands remain unchanged, which after propagating in a dispersive medium results in a tunable single-bandpass response in the RF domain. We experimentally verify the MPF. By adjusting the time delay and the optical spectrum bandwidth, the passband center frequency is continuously tuned from DC to 20 GHz and the 3 dB passband bandwidth changes while the optical spectrum bandwidth ranges from 1 to 4 nm.

New donor-π-acceptor type triazatruxene derivatives for highly efficient dye-sensitized solar cells.

A new class of organic dyes based on triazatruxene have been designed and synthesized for dye-sensitized solar cells. The photoelectronic properties of these donor-π-acceptor dyes can be tuned by changing π-conjugated linkers. The best performance was found for triazatruxene dye TD1, wherein, with thiophene as the conjugated linker and cyanoacrylic acid as the acceptor, a power conversion efficiency up to 6.10% was achieved.

High-speed microwave photonic switch for millimeter-wave ultra-wideband signal generation.

We propose a scheme for generating millimeter-wave (MMW) ultra-wideband (UWB) signal that is free from low-frequency components and a residual local oscillator. The system consists of two cascaded polarization modulators and is equivalent to a high-speed microwave photonic switch, which truncates a sinusoidal MMW into short pulses. The polarity switchability of the generated MMW-UWB pulse is also demonstrated.

An efficient PIFA-mediated synthesis of a directly linked zinc chlorin dimer via regioselective oxidative coupling.

The synthesis of a directly linked zinc chlorin dimer was first achieved by a facile and efficient oxidative coupling of zinc chlorin monomers with phenyliodine bis(trifluoroacetate) (PIFA). The reaction shows high regioselectivity at the 20-position near the hydrogenated pyrrole ring producing selective dichlorin in 74% yield.

Chaotic ultra-wideband radio generator based on an optoelectronic oscillator with a built-in microwave photonic filter.

We induce a microwave photonic bandpass filter into an optoelectronic oscillator to generate a chaotic ultra-wideband signal in both the optical and electrical domain. The theoretical analysis and numerical simulation indicate that this system is capable of generating band-limited high-dimensional chaos. Experimental results coincide well with the theoretical prediction and show that the power spectrum of the generated chaotic signal basically meets the Federal Communications Commission indoor mask. The generated chaotic carrier is further intensity modulated by a 10 MHz square wave, and the waveform of the output ultra-wideband signal is measured for demonstrating the chaotic on-off keying modulation.

Photonic ultrawideband signal generator using an optically injected chaotic semiconductor laser.

We propose and demonstrate a method to generate ultrawideband (UWB) signals in the optical domain based on the chaotic dynamics of an optically injected semiconductor laser with optical feedback. The chaotic-UWB pulses with a fractional bandwidth of 116% and central frequency of 6.88 GHz are experimentally generated by controlling the injection strength and frequency detuning of the chaotic laser. The spectrum of the UWB signals is in full compliance with the Federal Communications Commission spectral mask, and the experimental results are qualitatively consistent with the simulated results.

Photonic generation of ultrawideband pulse using semiconductor laser with optical feedback.

We propose and demonstrate an approach to the generation of an ultrawideband (UWB) pulse utilizing the nonlinear dynamics of a semiconductor laser (SL). The output UWB chaotic optical pulses generated by the SL with optical feedback can be controlled when the feedback strength and driving current of the SL are tuned. Our experiment proves that the spectrum characteristics of the UWB pulses satisfy Federal Communications Commission regulations, and the experimental results are consistent with the simulated results based on the laser's rate equations.

Interfacial molecular assemblies of metalloporphyrins with two trans or one axial ligands.

Molecular assemblies of metalloporphyrins trans-dichloro(5,10,15,20-tetra-p-tolylporphyrinato)tin(IV) (SnCl2TPPMe) and trans-dihydroxo(5,10,15,20-tetra-p-tolylporphyrinato)tin(IV) (Sn(OH)2TPPMe), which have two trans axial ligands, as well 5,10,15,20-tetrakis(4-methoxyphenyl)-21H,23H-porphine iron(III) chloride (FeClTPPOMe) and 5,10,15,20-tetraphenyl-21H,23H-porphine manganese(III) chloride (MnClTPP), which have one axial ligand, are interfacially organized by Langmuir and Langmuir-Blodgett (LB) techniques. SnCl2TPPMe and Sn(OH)2TPPMe form nanofibrous structures which can display distinct supramolecular chirality, although the molecular units themselves are achiral, while FeClTPPOMe and MnClTPP form irregular nanoparticles that display negligible supramolecular chirality. An interpretation in terms of the effects of the axial ligands is proposed for this interesting phenomenon. Moreover, compared with assemblies of the diprotonated free-base porphyrins, which are fabricated by interfacial (air/2.4 M HCl) organization of free-base porphyrin, those of SnCl2TPPMe and Sn(OH)2TPPMe display higher stability in terms of supramolecular chirality. These results indicate that the assembly properties of metalloporphyrins can essentially be affected by the axial ligands that are attached to their chromophores, and that stable chiral porphyrin supramolecular associations can be easily produced by using achiral metalloporphyrins bearing two trans axial ligands.

An efficient PIFA-mediated synthesis of fused diporphyrin and triply-singly interlacedly linked porphyrin array.

An efficient and metal-free oxidative method was reported for synthesis of triply linked diporphyrins with 2.5 equiv of phenyliodine bis(trifluoroacetate) (PIFA). This reaction showed high selectivity for Zn(II) porphyrins and had been successfully applied in the synthesis of a novel triply-singly interlacedly linked porphyrin array with lower energy gap.

Iron increases HMOX1 and decreases hepatitis C viral expression in HCV-expressing cells.

AIM: To investigate effects of iron on oxidative stress, heme oxygenase-1 (HMOX1) and hepatitis C viral (HCV) expression in human hepatoma cells stably expressing HCV proteins. METHODS: Effects of iron on oxidative stress, HMOX1, and HCV expression were assessed in CON1 cells. Measurements included mRNA by quantitative reverse transcription-polymerase chain reaction, and protein levels by Western blots. RESULTS: Iron, in the form of ferric nitrilotriacetate, increased oxidative stress and up-regulated HMOX1 gene expression. Iron did not affect mRNA or protein levels of Bach1, a repressor of HMOX1. Silencing the up-regulation of HMOX1 nuclear factor-erythroid 2-related factor 2 (Nrf2) by Nrf2-siRNA decreased FeNTA-mediated up-regulation of HMOX1 mRNA levels. These iron effects were completely blocked by deferoxamine (DFO). Iron also significantly decreased levels of HCV core mRNA and protein by 80%-90%, nonstructural 5A mRNA by 90% and protein by about 50% in the Con1 full length HCV replicon cells, whereas DFO increased them. CONCLUSION: Excess iron up-regulates HMOX1 and down-regulates HCV gene expression in hepatoma cells. This probably mitigates liver injury caused by combined iron overload and HCV infection.