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The electronic structures and photophysical properties of Ir(tpy)2(acac) complex (1) and the derivative (2, 3) with thiophene at different positions of tpy ligands have been investigated with density functional theory (DFT) and time-dependent density functional theory (TD-DFT), where tpy = 2,2-thienylpyridine, acac = acetylacetonate. 3a and 3b are studied to get insight into the influence of different positions of fluorine atoms on the photophysical properties of 3. The calculated results reveal that the introduction of thiophene are beneficial to enhance absorption intensity, decrease LUMO energy levels, and reduce the energy barrier for electron injection compared with 1. However, the decreased amount of metal orbitals involved in the transitions, small participation of metal to ligand charge transfer contribution in both the absorption (MLCT%) and emission spectra (3MLCT%), large energy difference between the S1 and Tm (ΔES1−Tm) for 2 (m = 1–2) and 3 (m = 1–3) compared with those of 1 account for their relatively low phosphorescence quantum yields (Φp) observed experimentally. Moreover, the incorporation of F atoms into complex 3 (3a, 3b) can be efficient approach of tuning the electron injection ability, balance of charge transfer process, and emitting color. Especially, the high quantum yield of 3b compared with 3a is explained based on the detailed analysis of the triplet energy (ET1), transition dipole moment (μS1) upon the S0 → S1, SOC matrix element between the Tm and Sn states, ΔES1−Tm, 3MLCT% in the phosphorescent spectra, energy difference between 3MLCT and electronic configurations of the triplet metal-centered (3MC) d–d excited states. These structure-property relationship is expected to provide useful information for synthesis highly efficiency phosphorescence emitters.

Theoretical investigation on a series of Pt(Ⅱ) complexes to evaluate the influence of diphenylamine group on the optical properties and their potential applications in PhOLEDs. The effect of different substituent positions (1a-1c) on the electronic structures and optical properties were fully explored by compared with the experimental synthesized complex 1. The functionalized diphenylamine moiety can tune the geometrical structures, frontier molecular orbitals, absorption and emission spectra, radative rate (kr), possbile nonradative process T1(3MLCT/π → π*) → TS(d-d)→3MC(d-d) → MECP(d-d), charge injection and transfer properties. The findings could help to understand the influnece of dipenylamine group and design high efficient red guest emitters in PhOLEDs.

Quantum-chemistry methods are used to investigate the effect of phenylamine chromophore on the electronic structure, optical properties, and phosphorescence efficiencies of a series of fac -iridium(III) complexes, Ir-(g0) 3 (1) , meta-substituted Ir compounds [Ir-(g0) 2 -(g1) 1 ] (1a) , [Ir-(g0) 1 -(g1) 2 ] (1b) , [Ir-(g1) 3 ] (1c) and para-substituted Ir compounds [Ir-(g0) 2 -(g1′) 1 ] (2a) , [Ir-(g0) 1 -(g1′) 2 ] (2b) , [Ir-(g1′) 3 ] (2c) , where g0 = l -phenylisoquinolinato, g1 = 4-(isoquinolin-1-yl)- N , N -diphenylbenzenamine, g1′ = 3-(isoquinolin-1-yl)- N , N -diphenylbenzenamine. The calculations show that introduction of phenylamine chromophore at meta position of phenyl ring ( 1a – 1c ) slightly changes the ground-states geometries but largely increases the energy of HOMO and decreases IP values hence improves the ability of hole injection, which is consistent with the experimental report. The introduction of diphenylamine substitutions on the para position ( 2a – 2c ) is effective for extending the π-electron delocalization, which results in strengthening metal-ligand bond and dramatically increasing the HOMO energy. More important, the 2a – 2c have enhanced metal-to-ligand charge transfer 3 MLCT participation in the phosphorescent spectra, decreased the singlet-triplet splitting energy (Δ E S1–T1 ), as well as dramatically small energy differences between the highest occupied orbitals splitting (Δdd occ ) and large lowest unoccupied d-orbitals splitting (Δdd*) at the both S 0 and T 1 geometries, these account for the quantum yield and efficiency of phosphorescence. The calculated ionization potentials (IPs), electronic affinities (EAs), and reorganization energy ( λ ) confirm that the hole and electron injection and transfer ability were enhanced by importing the diphenylamine. Furthermore, based on the analyses of triple energy differences between host and guest, charge carrier mobility, optical overlap, it is found that these Ir complexes maybe good guest materials in CBP. Thus, the introduction of phenylamine at para position is effective approach to obtain highly efficient red phosphorescent emitters.

The electronic structures and photophysical properties of a series of Ir(III) complexes, Ir(C^C)(ppy)2, Ir(C^C)(ppy)(OrtCF3), Ir(C^C)(ppy)(MeCF3) and Ir(C^C)(ppy)(ParCF3), where ppy=2-phenylpyridine, C^C=1-(2,4-difluorophenyl)-1H-imidazole, OrtCF3=2-(2-(trifluoromethyl)phenyl)pyridine, MeCF3=2-(3-(trifluoromethyl)phenyl)-pyridine, and ParCF3=2-(4-(trifluoromethyl)phenyl)pyridine, were investigated by density functional theory calculation employing the mPW1PW91 density functional. The simulated electronic structure, absorption spectra, and phosphorescence of Ir(C^C)(ppy)2 were in good agreement with the experimental values. Compared with Ir(C^C)(ppy)2, it was found that introduction of the CF3 substituent on the ortho -and para -position of ppy was more useful to strength the metal-ligand bond, enhance the electron injection ability, as well as red-shifted the absorption spectra and phosphorescence. Furthermore, Ir(C^C)(ppy)(OrtCF3) had increased participation of triplet metal to ligand charge transfer (3MLCT) contributions, large transition dipole moment ( m S1) and d orbital splitting, small singlet-triplet splitting energy (D E S1-T1) compared with other complexes, which indicated Ir(C^C)(ppy)(OrtCF3) would be potential phosphorescence emitters with high quantum yield.

The electronic structures and photophysical properties of a series of blue-emitting Ir(Ⅲ) complexes, Ir(ppy) 2 (C ∧ C)]( 1′ ), Ir(ppy) 2 (CF ∧ C)]( 1 ), [Ir(ppy) (MeFPP) (CF ∧ C)]( 2 ), [Ir(MeFPP) 2 CF ∧ C)]( 3 ), [Ir(ppy) (PaOrFPP) (CF ∧ C)]( 4 ), [Ir(PaOrFPP) 2 (CF ∧ C)]( 5 ), where C ∧ C = 2,3-dihydro-1-methyl-3-phenyl-1H-imidazole, CF ∧ C = 1-(2,4-difluorophenyl)-2,3-dihydro-3-methyl-1H-imidazole, ppy = 2-phenyl- pyridine, MeFPP = 2-(3,5-difluorophenyl)pyridine and PaOrFPP = 2-(2,4-difluorophenyl)pyridine, were investigated by density functional theory and time-dependent density functional theory calculations employing the mPW1PW91 density functional. The simulated electronic structure, absorption spectra, and phosphorescent of complex 1′ and 1 were in good agreement with the experimental values. The calculated energy values of HOMO, LUMO, ionization potential (IP), electron affinity (EA), and reorganization energy (λ) showed that the abilities of electron injection and transport were dramatically improved by introducing electron-withdrawing fluorine atoms. Additionally, those Ir complexes containing fluorine atoms strengthened the metal-ligand bond and increased the participation of MLCT contribution in absorption spectra compared with 1 ′ and thus further improved the collection of light energy participation from metals. Furthermore, the detailed analysis of participation of 3 MLCT contributions, E T1 , ΔE S1-T1 , d-orbital splitting revealed that the quantum yield was effectively enhanced both by introducing the fluorine atoms at 2,4-position of phenyl on the ppy ligand and by increasing the number of fluorine atoms. We hope this work is useful to gain the structure-property relationship and provide valuable information for designing highly blue phosphorescent materials for organic light-emitting diodes (OLEDs).

To design efficient organic sensitizer, a series of D-π-A indoline dyes with different donor parts have been investigated by density functional theory (DFT) and time-dependent DFT (TD-DFT) approach. The molecular geometries, frontier molecular orbitals, and absorption spectra of these dyes have been systematically investigated to provide comprehensive understanding of the structure-property relationships. Compared with D149, our designed dyes have proper HOMO and LUMO energy level, narrowed HOMO-LUMO energy gap, and broadened absorption band by introducing the N(CH3)2and N(phenyl)2groups at the donor part. Furthermore, the dimeric dyes and dye-(TiO2)6systems have been optimized by DFT method to simulate the intermolecular interactions, as well as interaction between the dyes dimmers and semiconductor interface, respectively. Through the analyses of absorption energies (Eads), energy levels of the HOMO and LUMO, light harvesting efficiency (LHE), and the driving force of electrons injections (ΔGinject), it is found that the designed dyes should have improved optical properties by importing the N(CH3)2group. This work is hoped to provide a theoretical guiding role in design of new dyes for dye-sensitized solar cells.

A series of silicon (VI) porphyrins compounds with varying meso substitutions Si (TPP)Cl2 (where X=5,10,15,20-tetraphenylporphyrin), Si (TFP)Cl2 (X=5,10,15,20-tetrafluorenylporphyrin), Si (TQP)Cl2(X=5‚10‚15‚20-tetra (2,3,6,7-tetrahydro-1H,5H-benzo [ij] puinolizine) porphyrin),Si (TMP)Cl2(X=5,10,15,20-tetra (N,N-dimethylphenyl) porphyrin) have been investigated using density functional theory (DFT) to assess the influence of ruffled conformation on the electronic structures, frontier molecular orbital, charge carrier transport, electronic spectra. The electronic structures reveal that all these Si porphyrins display visible ruffling distortion, as the dihedral angle Cα2-N2-N4-Cα4 are ca. 30 ̊. And calculations confirm that ruffed distortion result in higher LUMO energies, lower EA values than corresponding planed Zn porphyrins, especial for similar λhole and λelectron values. These calculations suggest that the ruffled conformation bring about better charge injection and transport, which would broaden the application of distorted porphyrin in several different fields.

As a key factor for promoting electron transfer to the semiconductor, the intramolecular charge transfer (ICT) process in dye-sensitized solar cells (DSSCs) is crucial to enhancing the conversion efficiency. In this study, the effects of anchoring groups on charge transfer during dye excitation and interfacial electron injection from the dyes to the semiconductor were theoretically investigated. The calculation results indicate that the sensitizers with hydantoin anchoring groups, namely HY-4, HY-3, HQ-4, and HQ-3, can significantly adjust the orbital energy levels and increase the HOMO-LUMO energy gaps. Importantly, the ICT process of sensitizers before and after binding TiO2 cluster were detected via frontier molecular orbitals, electronic transition processes and transferred charges on the basis of the excitation (qCT), the transferred charge distance (dCT) and the dipole moment (μCT). The calculation results confirm that HY-4 and HY-3 greatly improve ICT performances relative to CA-4, which successfully interprets the experimentally observed efficiency difference. Moreover, the inserting acceptor moiety quinoxaline and hydantoin anchoring groups, namely HQ-4 and HQ-3, play an important role in raising the efficiency of ICT process. The finding can promote further understanding of the relationship between structure and performance of organic dyes containing hydantoin anchoring groups, so as to help them become more efficient dyes for DSSCs.

The stepwise hydrogenation of the C=C bond and C=O group of acrolein on Au3 and Au5 model systems is investigated using the density functional theory(DFT) PW91 functional. Our results show that the C=C hydrogenation is more favorable than that of C=O bond on Au3 with the barriers of the rate-determining step being 0.35 and 0.62 eV respectively. On the other hand, the C=O reduction is preferred over the hydrogenation of the C=C bond on Au5. The corresponding barriers of the rate-determining steps are 0.45 and 0.54 eV, respectively. This demonstrated that the second hydrogenation step controls the reaction on both Au3 and Au5 for C=O and C=C hydrogenation and the C=O hydrogenation on Au5 is preferred over the hydrogenation of the C=C bond, which is helpful to address the reactivity of small size-selected supported gold clusters.

A density functional theory and time-dependent density functional theory approaches were used to understand the structure–property relationships of a series of Ir(III) complexes Ir(x-NHC)(y-ppy)2 [where NHC = 2,3-dihydro-1-methyl-3-phenyl-1H-imidazole, ppy = 2-phenylpyridine, x = Cl, y = H (1a); x = Cl, y = Cl (1a-Cl); x = Cl, y = F (1a-F); x = Cl, y = CN (1a-CN); x = Cl, y = CF3 (1a-CF 3 ); x = F, y = CF3 (2-CF 3 )]. The investigations on the electronic structures in the ground and lowest triplet excited states, the frontier molecular orbitals, the absorption and emission spectra, as well as charge injection and transport of these Ir complexes provided a good understanding of the structure–property relationships. Furthermore, the full details of the metal character in the phosphorescent spectra(3MLCT %), triplet energy (E T1), the singlet–triplet splitting energy (ΔE S1–Tn), 3MLCT–3MC energy gap, as well as d orbitals splitting revealed that quantum yield was effectively enhanced by introducing CN and CF3 groups on the ppy ligands. The designed complexes 1-CN, 1-CF 3 , and 2-CF 3 are expected to be highly efficient phosphorescent materials in organic light-emitting diodes.

The geometries, frontier molecular orbitals, charge injection and transfer, as well as spectroscopic properties of a series of novel bis(8-hydroxyquinolinato) (Ptq2) derivatives with oligothiophenes moiety were investigated theoretically. The calculated results indicated that incorporating of oligothiophene units into the Ptq2 had major role in the tailoring the optical properties. Furthermore, from the analyses of ionization potentials (IP), electron affinity (EA), reorganization energy (λ), it was found that these Pt derivatives have excellent hole and electron injection and transfer ability by introducing the oligothiophenes at the 7-positions of the quinoline ligand. These results are favorable to establish the structure–photophysical property relationship for enhancing the carrier transfer abilities of Ptq2.

Star-shaped molecules with tailoring functional groups in the core and the arms have great potential application in organic light-emitting devices, because it can be designed to realize low band gap, broad absorption, and excellent solubility for low-cost solution process. To gain an insight into the structure–property relationships, a set of four-arm star-shaped molecules with 2,1,3-benzothiadiazole as the core, different π-conjugated groups as the arm, and triphenylamine or 2-(pyridin-2-yl) pyridine as the end-group were designed. In this study, a systematic investigation into them was carried out using the density functional theory and time-dependent density functional theory methods. The calculated ionization potentials, electron affinities, and reorganization energies (λ) show that the properties of the π-conjugated bridge and the end-group significantly affect the carrier injection and transport characteristics of these molecules, especially for S-BTDP and S-EBTD. Among these molecules, S-BTDP exhibits better electron injection ability due to the introduction of 2-(pyridin-2-yl) pyridine as the end-group. However, S-EBTD, with ethylene as π-conjugated bridge, has excellent hole injection and carrier transport behaviors. We also calculated the singlet-to-triplet exciton-formation cross-section ratio (σS/σT), the exciton-formation fractions (χS), and the absorption and emission spectra of these molecules. We calculated that σS/σT ranges from 1.78 to 2.76 and that χS is ca. 0.37–0.48. These molecules have two absorption bands in the range of 340–410 nm and 500–613 nm, respectively. The calculated emission spectra range from 619 to 706 nm. It can be deduced that the studied 2,1,3-benzothiadiazole-based star-shaped molecules can serve as efficient red light-emitting electroluminescent materials.

The photophysical properties of organoboron quinolate derivatives can be modified readily by manipulating the coordination environment around the central boron atom. This class of compounds applied in organic light-emitting diodes (OLEDs) materials has been studied by quantum chemistry. To reveal the relationship between the structures and properties of these electroluminescent materials, the ground- and excited-state geometries were optimized at the B3LYP/6-31G(d) and CIS/6-31G(d) levels, respectively. The ionization potentials and electron affinities were computed. The mobilities of hole and electron in these compounds were studied computationally based on the Marcus electron transfer theory. The maximum absorption and emission wavelengths of these compounds were calculated using the time-dependent density functional theory method. The solvent effect on the absorption and emission wavelengths of these compounds was also considered by a polarizable continuum model. These results show that boron compounds which containing both the hydroxyquinoline/hydroxybenzoquinoline as ligand and O/S in position X follow the rule, that is, the emission shifts to longer wavelength as covalent nature of the boron–ligand bonding is increased. Meanwhile, the negative HOMO and IPs decrease but the negative LUMO and EAs increase by substitution of O with S in position X. It was deduced that both the hole- and electron-injection abilities are improved by substituting S in place of O in position X. After chemical modification in position R 2 with electron-donating properties of NH2 or 1,4-diethynyl-2,5-dihexyloxybenzene, introduced 1,4-diethynyl-2,5-dihexyloxybenzene improves both the hole- and electron-transfer rate, which leads to better equilibrium property. It can be concluded that the better equilibrium property depends on the conjugated length of side chain in position R 2. Moreover, exchanging the substituents R 1 and R 2 in BNO1a and BNO1’a can slightly change the hole-transfer rate by 0.04 eV. According to these calculations, series BNO and BNS can be applied as electron transport and hole transport materials at the same time. Specially, series BNO2 and BNS have better performance than Mes2B[p-4,4’-biphenyl-NPh(1-naphthyl)] (BNPB) in both the hole- and electron-injection ability.

The electronic structures, charge injection and transport, absorption and emission spectra, properties of two series of fluorene-based oligomers {2-[2-{2-[5-(9H-Fluoren-3-yl)-thiophen-2-yl]-vinyl}-6-(2-thiophen-2-yl-vinyl)-pyran- 4-ylidene]-malononitrile} n (FTPM) n and {2-{2-{2-[5-(9H-Fluoren-2-yl)-2-hydroxy- 3-methoxy-phenyl]-vinyl}-6-[2-(2-hydroxy-3-methoxy-phenyl)-vinyl]-pyran-4- ylidene}-malononitrile} n (FOOPM) n (n = 1–4) have been investigated by the density functional theory (DFT) approach. The ground-state geometries of (FTPM)4 and (FOOPM)4 optimized at B3LYP/6-31G(d) level exhibited zigzag arrangements. The energies of HOMO and LUMO, HOMO–LUMO energy gaps (ΔE H–L) of (FTPM) n and (FOOPM) n (n = ∞) were obtained by linear extrapolation method. Moreover, the calculations of ionization potential (IP), electronic affinity (EA), and reorganization energy (λ) were used to evaluate the charge injection and transport abilities. For (FTPM)4 and (FOOPM)4, the TDDFT calculations revealed that the absorption peaks can be characterized as π–π* transition and couple with the location of electron density distribution changes in different repeat units. All the earlier theoretical investigations are intended to establish the structure–property relationships, which can provide guidance to design the organic light-emitting diodes (OLEDs) with high performance.

The density functional theory (DFT) has been applied to investigate the photophysical properties of meso-substituted porphyrins: 5,15-difluorenylporphyrin (DFP), 5,10,15,20-tetrafluorenylporphyrin (TFP), Zn-5,10,15,20-tetrafluorenylporphyrin (FPZ) and Zn-5,10,15,20-tetrafluorenoneporphyrin (OPZ). The geometry structures, frontier molecular orbitals, ionization potential (IP), electron affinity (EA) and reorganization energy ( λ ) together with the absorption and emission wavelengths of these compounds were investigated. Theoretical calculations indicated that the introduction of meso-substitutions brought about significant effect on the photophysical properties. The TFP molecule has lowest hole injection energy barrier of all the studied compounds, and OPZ owns lowest electron injection energy barrier of them. The equilibrium of the hole and electron transport of FPZ is better than those of porphyrin (FBP), DPZ, TFP, and OPZ. The electron reorganization energies ( λ electron ) of FBP, DFP, TFP, FPZ and OPZ are 0.22 eV, 0.20 eV, 0.23 eV, 0.26 eV and 0.13 eV, respectively, which are smaller than tris(8-hydroxyquinolinato) aluminum(III), thus these molecules are potential electron transport materials. Their visible absorption wavelengths are calculated by TD-B3LYP and semi-empirical ZINDO methods, and these results agree with corresponding experimental values. The fluorescence spectra of these complexes predicted by TD-HF method exhibit more consistent results with experimental data than by TD-B3LYP method.

In this case-control study, we investigated the association between DNA damage and genetic susceptibility among vinyl chloride monomer (VCM)-exposed workers. The cumulative exposure dose of VCM was calculated based on the workers' duration of exposure and the geometric mean concentration of VCM in the workplace. DNA damage to peripheral blood lymphocytes was measured by single cell gel electrophoresis (SCGE) assay, and single nucleotide-polymorphisms (SNPs) in xenobiotic metabolism and DNA repair genes were detected by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methods. Univariate analysis showed that the CYP2E1 c1c2/c2c2 and XPD751 Lys/Gln and Gln/Gln genotypes were significantly associated with the levels of DNA damage (P0.01 and 0.05, respectively). Further logistic regression analysis showed a significant association between CYP2E1 c1c2/c2c2 and DNA damage, and risk of having increased levels of DNA damage was more pronounced in those individuals having XRCC1 194 mutant genotypes and/or XPD751 Lys/Gln and Gln/Gln genotypes. Although most of the XPD and XRCC1 haplotypes did not show any significant difference, the XRCC1 haplotype Trp194-Arg280 was significantly over-represented in the case group (P0.05; OR 2.09; 95% CI: 1.07-4.06) than in controls. Overall, our data suggest that the genotypes of CYP2E1, XRCC1 194, and XPD 751 were associated with the level of DNA damage and may contribute to individual sensitivity to DNA damage induced by VCM in the workplace.

A new series of triphenylamine-based indoline dye sensitizers were molecularly designed and investigated for their potential use in dye-sensitized solar cells (DSSCs). Theoretical calculations revealed that modifying donor part of D149 by triphenylamine significantly altered the electronic structures, MO energies, and intramolecular charge transfer (ICT) absorption band. Key parameters associated with the light-harvesting efficiency at a given wavelength LHE(λ), the driving force ΔG inject, and the open-circuit photovoltage V oc were characterized. More importantly, these designed (dimeric) dye sensitizers were found to have similar broad absorption spectra to their corresponding monomers, indicating that modifying the donor part with triphenylamine may stop unfavorable dye aggregation. Further analyses of the dye-(TiO2)9 cluster interaction confirmed that there was strong electronic coupling at the interface. These results are expected to provide useful guidance in the molecular design of new highly efficient metal-free organic dyes.

The geometrical structures and photophysical properties of Ir(4,6-dFppy)2(pic) (FIrpic) and its derivative (o-FIr, m-FIr, p-FIr) with dimethylamine substituted at the picolinic acid (N∧O) ligand were fully investigated by density functional theory and time-dependent density functional theory. The simulated electronic structure, as well as absorption and emission spectra of FIrpic are in good agreement with the experimental observations. The introduction of dimethylamine at the N∧O ligand at different positions is beneficial to extend the π-electron delocalization, increase HOMO energy levels, and hence improve the hole injection and transfer ability compared with those of FIrpic. Furthermore, o-FIr, m-FIr, and p-FIr have large absorption intensity and participation of metal-to-ligand charge transfer (MLCT) contribution in the main absorption spectra, which would be useful to improve the intersystem crossing (ISC) from the singlet to triplet excited state. More importantly, the high quantum yield of o-FIr (which is explained based on the detailed analysis of triplet energy, ET1), participation of 3MLCT contribution in the phosphorescent spectra, and energy difference between 3MLCT and triplet metal centered (3MC) d-d excited state compared with m-FIr and p-FIr indicate that o-FIr is expected to be an excellent blue phosphorescence emitter with high efficiency.

Vp1 gene of O type foot-and-mouth diseases virus and M. tuberculosis HSP70 were expressed in methylotrophic yeast Pichia pastoris expression system. The results of cellular immune responses and humoral immune response were examined after BALB/c mice were immunized with fusion protein expressed in methylotrophic yeast Pichia pastoris. The genes was cloned into the vector pPICZalpha-A by routine molecular technique. The plasmid fusion (pPICZalphaA-vp1-HSP70) was created that HSP70 located downstream of VP1 gene of O type foot-and-mouth disease virus. Vp1 was expressed by fusing to the amino terminus of M. tuberculosis hsp70 in yeast Pichia pastoris. The recombined fusion plasmid was transformed into methylotrophic yeast Pichia pastoris X-33 by electrophoration. The recombinant transformants were selected by Zeocin and induced by the addition of methanol every 24h. The expressived product analyzed by SDS-PAGE and Western blotting. The result indicated that the fusion protein(vp1-HSP70) has specific antigenicity. Mice were inoculated transcutaneous three times at a two-weeks interval with fusion protein, PBS and conventional inactivated vaccines. To evaluate the prophylaxtic efficacy of fusion protein, Titers of antibodies was detected by ELISA and proliferation of lymphocytes were determined by MTT. The results indicated that fusion protein could elicit specific humoral immune and cellular immune responses. Compared with conventional inactivated vaccines, fusion protein elicited slightly lower FMDV antibody level but stronger T cell proliferation.

A FAAS method was established for the determination of Na, K, Mg, Ca, Cu, Zn, Fe, Mn, Ni, Co, Pb, Cr, Cd, Ag and Au in Cynomorium songaricum after digestion with HNO3-HClO4 (phi 4:1) at 90-95 degrees C and at normal pressure. In this paper, the parameters in FAAS were studied. The analytical results of Na, K, Mg, Ca, Fe, Zn, Cu, Mn, Pb, Ni and Ag were 13,572.0, 14,260.0, 358.3, 168.3, 238.5, 19.4, 5.9, 3.4, 2.6, 1.3 and 0.4 microg x g(-1) respectively and Co, Cr, Cd and Au were not found in the samples. The results showed that the recovery of standard addition was 97.8%-104.5%, and the relative standard deviation (n = 9) was 0.2%-5.0%. The method is fast, simple and convenient. The results were satisfactory.

AIM: The permissible exposure limit (PEL) of vinyl chloride monomer (VCM) in developed country was 1 p/m (2.79 mg/m3); and threshold limit value-short term exposure limit (TLV-STEL) in China was 11 times higher [11 p/m (30 mg/m3)] than it, till 2002. The mechanism of vinyl chloride monomer (VCM)-related carcinogenesis remains unclear. We aimed to analyze occupational health hazards exposure to doses lower than the Chinese occupational health standard in a selected VC polymerization plant in China, and also to elucidate the relationship between genetic polymorphisms and genetic susceptibility on liver lesions of workers exposed to VCM. METHODS: In order to explore the mechanism of VCM-related health effects, we used a case-control design to investigate the association between the genetic polymorphisms of metabolic enzymes and liver lesions in workers occupationally exposed to VCM. Genotypes of CYP2E1, GSTT1, GSTM1, ALDH2 and ADH2 were identified using PCR and PCR-RFLP. RESULTS: Even when the concentration of VCM was lower than the current Chinese occupational health standard, neurasthenia, pharyngeal irritation, liver ultrasonography abnormalities and hemoglobin disorders were significantly higher in exposure subjects compared to non-exposure subjects, and the relative risks (RR and 95% CI) were 1.74 (1.06-2.85), 1.97 (1.56-2.48), 10.69 (4.38-26.12), and 2.07 (1.20-3.57). CYP2E1 c1c2/c2c2 genotype was significantly associated with liver damages (OR 3.29, 95% CI 1.51-7.20, P < 0.01). CONCLUSION: The incidences of neurasthenia and liver ultrasonography abnormalities significantly increase when the cumulative exposure dose increases. The genotypes of metabolic enzymes (CYP2E1 c1c2/c2c2, null GSTT1 and ADH2 1-1) play important roles in VCM metabolism. Polymorphisms of CYP 2E1, GSTT1 and ADH2 may be a major reason of genetic susceptibility in VCM-induced hepatic damage.