Synthesis and electrochemical behavior of poly N, N′-dithiobis (1,3-phenylenediamine)

A novel organic disulfide, N, N′-dithiobis(3-nitroaniline)(1) was prepared by the reaction of 3-nitroaniline with sulfur monochloride in chloroform. Compound 1 was reduced by zinc powder to give N, N′-dithiobis(1,3-phenylenediamine) (2). Poly N, N′-dithiobis (1,3-phenylenediamine) (3) was prepared by electrochemical polymerization of compound 2 and its basic electrochemical behavior is discussed. Foundation item: Supported by the National Natural Science Foundation of China (29833090) Biography: Li Zao-ying (1949-), female, Professor, research direction: synthesis and properties of organic cathode materials of rechargeable lithium batteries.     

Nitric oxide suppresses stomatal opening by inhibiting inward-rectifying K<Stack><Subscript>in</Subscript><Superscript>+</Superscript></Stack> channels in <Emphasis Type="Italic">Arabidopsis</Emphasis> guard cells

We explore nitric oxide （NO） effect on K^＋in, channels in Arabidopsis guard cells. We observed NO inhibited K^＋in, currents when Ca^2＋ chelator EGTA （Ethylene glycol-bis（2-aminoethylether）-N,N,N′,N;tetraacetic acid） was not added in the pipette solution; K^＋in currents were not sensitive to NO when cytosolic Ca^2＋ was chelated by EGTA. NO inhibited the Arabidopsis stomatal opening, but when EGTA was added in the bath solution, inhibition effect of NO on stomatal opening vanished. Thus, it implies that NO elevates cytosolic Ca^2＋ by activating plasma membrane Ca^2＋ channels firstly, then inactivates K^＋in, chartnels, resulting in stomatal opening suppressed subsequently.     

Synthesis, supramolecular structures and luminescent properties of quinacridone derivatives bearing carbazole groups

The syntheses of three carbazyl-containing quinacridone derivatives, N,N’-di((N-carbazyl)-n-butyl) quinacridone (DCBQA), N,N’-di((N-carbazyl)-n-hexyl)quinacridone (DCHQA) and N,N’-di((N-carbazyl)-n-octyl)quinacridone (DCOQA), are reported, and the photoluminescent (PL) characteristics are pre- sented. The single crystal X-ray structures of DCBQA, DCHQA and DCOQA are investigated. The crystal of DCBQA is characterized by intermolecular π…π interactions between quinacridone cores and carbazole moieties result...     

Genome sequencing and characterization analysis of a Beijing isolate of chicken coronavirus infectious bronchitis virus

Avian infectious bronchitis virus (AIBV) is classified as a member of the genus coronavirus in the family coronaviridae. The enveloped virus has a positive-sense, single-stranded RNA genome of approximately 28 kilo-bases,which has a 5‘ cap structure and 3‘ polyadenylation tract.The complete genome sequence of infectious bronchitis virus (IBV), Beijing isolate, was determined by cloning sequencing and primer walking. The whole genome is 27733 nucleotides in length, has ten open reading frames:5′-orfla-orflab-s-3a-3b-e-m- 6a-6b-n-3′. Alignments of the genome sequence of IBV Beijing isolate with those of two AIBV strains and one SARS coronavirus were performed respectively. The genome sequence of IBV Beijing isolate compared with that of the IBV strain LX4 (uncompleted, 19440 bp in size) was 91.2% similarity. However, the full-length genome sequence of IBV Beijing isolate was 85.2% identity to that of IBV Strain Beaudette, and was only 50.8% homology to that of SARS coronavirus. The results showed that the genome of IBV has remarkable variation. And IBV Beijing isolate is not closely related to SARS coronavirus. Phylogenetic analyses based on the whole genome sequence, S protein, M protein and N protein, also showed that AIBV Bering isolate is lone virus in group Ⅲ and is distant from SARS coronavirus. In conclusion, this study will contribute to the studies of diagnosis and diseases control on IBV in China.     

Orientational domains at room temperature in La0.33Ca0.67MnO3 perovskite

Orientational domains at room temperature in orthorhombic perovskite La_0.33Ca_0.67MnO₃ were studied by group-theory and observed systematically using transmission electron microscopy. There are six orientational variants (A, A′, B, B′, C andC′) in orthorhombic perovskite La_0.33Ca_0.67MnO₃. Their orthorhombicb _o directions are parallel to thea _p,b _p andc _p directions of the cubic prototypic perovskite, respectively. In each case there are two orientational variants (e.g.,A andA′) with theira _o andc _o axes interchanged. Among the possible 15 boundaries between these 6 variants there are only two types of domain boundaries: (1) m<100>boundariesC′/C, A′/A, andB′/B. (2) m<110>boundaryiesC′/A, C′/A′, C′/B, C′/B′, C/A, C/A′, C/B, C/B′, B′/A, B′/A′, B/A, andB/A′. Foundation item: Supported by the National Natural Science Foundation of China (19974031) and US DOE(DE-AC02-98CH10886) Biography: WANG Ren-hui (1937-), male, Professor.     

Almost every graph has a fixed edge

An edge e of a graph G is called a fixed edge if G-e+e′ G implies e′=e, and an isomorphic fixed edge if G-e+e′ G implies that there exists an automorphism of G-e, which maps the ends of e to the ends of e′. It is proved that almost every graph is with all its edges as fixed edges and isomorphic fixed edges, and it is conjectured that all graphs contain isomorphic fixed edges.     

Study on synthesis and herbicidal activity of heterocyclic compounds containing P-P bond

N,N′-diphenylurea reacted with phosphorus trichloride and phenyl dichlorophosphane giving the heterocyclic compounds 1 and 2 with a direct phosphorus-phosphorus bond (P-P bond), respectively. The new compounds were characterized by elementary analysis, NMR and IR spectra. The results of preliminary bioassay showed that these heterocycles possess selective herbicidal activity at 1.5 kg/hm². Supported by China Postdoctoral Science Foundation and the Dawn Plant for Young Scienists of Wuhan City He Liangnian: horn in 1964, Associate Professor     

Inhibition of bromophenols against PTP1B and anti-hyperglycemic effect of <Emphasis Type="Italic">Rhodomela confervoides</Emphasis> extract in diabetic rats

Protein tyrosine phosphatase 1B （PTPIB） plays an important role as a negative regulator In insulin signaling pathways. PTPIB is an effective target for the treatment of type 2 diabetes mellitus. Four bromophenol derivatives from red algae Rhodomela confervoides, 2,2＇,3,3＇-tetrabromo-4,4＇,5,5＇-tetrahydroxydiphenyl methane （1）, 3-bormo-4,5-bis（2,3-dibromo-4,5-dihydroxybenzyl） pyrocatechol （2）, bis（2,3-dibromo-4,5-dihydroxybenzyl） ether （3） and 2,2＇,3-tribromo-3＇,4,4＇,5-tetrahydroxy-6＇-ethyloxymethyldiphenylmethane （4） showed significant inhibitory activity against PTPIB （IC50 were 2.4, 1.7, 1.5 and 0.84 μmol/L, respectively） as potential therapeutical agents for the treatment of type 2 diabetes mellitus. The anti-hyperglycemic effects of the ethanol extracts from If. confervoides on streptozotocin-induced diabetes （STZ-diabetes） in male Wistsr rats fed with high fat diet were investigated. The STZ-diabetic rats treated with medium-dose and high-dose alga extracts showed remarkable reductions in fasting blood glucose （FBG） as compared with the STZ-diabetic control. The results indicate that the in vivo anti-hyperglycemic activity of the R. confervoides extracts can be partially attributed to the inhibitory actions against PTPIB of the bromophenol derivatives and that may be of clinical Importance in improving the management of type 2 diabetes mellitus.     

Lithium bond structures of HnY （n=2, 3; Y=O,S, N）…LiNH2 and the abnormal blue shift of N-Li bond

The optimized geometries of the complexes between HnY （n=2, 3; Y=O, S, N） and LiNH2 have been calculated at the B3LYP/6-311＋＋G^＊＊ and MP2/6-311＋＋G^＊＊ levels. Three stable complexes were obtained. Frequency analysis showed that the enlarged 2N-4Li presents the abnormal blue shift in three complexes. The calculated binding energy with basis set super-position error （BSSE） and zero-point vibrational energy （ZPE） corrections of complex Ⅰ-Ⅲ is -58.65, -31.66 and -69.59 kJ·mol^-1 （MP2）, respectively. Natural bond orbital theory （NBO） analysis has been performed, and the results revealed that the H2O…LiNH2 （complex I） and H3N…LiNH2 （complex Ⅲ） are formed with coexisting σ-s and n-s type lithium bond interactions, complex Ⅱ is formed with ττ-s type lithium bond interaction between HnY （n=2,3; Y=O, N） and LiNH2, and H2S…LiNH2 （complex Ⅱ） is formed with n-s type lithium bond interaction between H2S and LiNH2. Natural resonance theory （NRT） and atom in molecule （AIM） theory have also been studied to investigate the bond order and topological properties of the lithium bond structures.     

Bridging of Calixarenes with N, N＇-Bis（Chloroacetyl） Propylenediamine

A new bridging reagent, N, N‘-bis (chloroacetyl) propylenediamine was used to explore the relativeactivity and bridging pattern of p-ten-bury lcalix [4] arene, p-tert-butylcalix [6] arene and butylcalix [8] arene. It wasfound that the bridging reaction is selectively, at least, preferably at 1, 3-position for p-tert-butylcalix [4] arene and p-tert-butylcalix [6] arene, 1,5-position for p-tert-butylcalix [8] arene. Taking the yield of bridged calixarene as a compar-sion standard, the activity decreases with the increasing of the number of phenolic units in calixarene.     

Study on synthesis and herbicidal activity of heterocyclic compounds containing P-P bond

N,N′-diphenylurea reacted with phosphorus trichloride and phenyl dichlorophosphane giving the heterocyclic compounds 1 and 2 with a direct phosphorus-phosphorus bond (P-P bond), respectively. The new compounds were characterized by elementary analysis, NMR and IR spectra. The results of preliminary bioassay showed that these heterocycles possess selective herbicidal activity at 1.5 kg/hm². Supported by China Postdoctoral Science Foundation and the Dawn Plant for Young Scienists of Wuhan City He Liangnian: horn in 1964, Associate Professor     

Synthesis and X-ray crystal structure of a new manganese 18-metallacrown-6

0　IntroductionThemetalionsinmetallamacrocylesformedbysupramolecularself assemblycantaketrigonal,square planar,andtetrahe dralconfiguration[1 ,2 ] .Metallacrownisaspecialclassofmetalla macrocyle,theyareanalogoustocrownethersinbothstructureandfunctionexceptthatthemetalionsarenowtakingthepositionsofcoordinationatomsincrownether[3,4] .Themetallacrownswithdifferentnumberof [M—N—O]repeatunithavedifferentcavitysizes,suchas 9 MC 3[5 7] ,12 MC 4 [4,8 1 4 ] and 15 MC 5 [1 5] .Thereportedazameta…     

Synthesis and light-emitting properties of organic electroluminescent compounds and their metal complexes

Several organic electroluminescent (EL) compounds, 2,2‘-(1,4-phenylenedivinylene)bis-3,3-dimethyl-indolenine (1), 2,2‘-(1,4-phenylenedivinylene)bis-benzoxazole (2), 2,2‘-(1,4-phenylenedivinylene)bis-benzothiazole (3), 4,4‘-(1,4-phenylenedivinylene)bis-quinoline (4), 2,2‘-(1,4-phenylene divinylene)bis-quinoline (5), 2,2‘-(1,4-phenylenedivinylene)bis-1,3,3-trimethyl-indolenine dichlo ride (6), 2,2‘-(1,4-phenylene-divinylene)bis-1-hydro-3,3-dimethyl-indolenine dichloride (7), 2,2‘-(1,4-phenylenedivinylene)bis-8-acetoxy-quinoline (8), 2,2‘-(1,4-phenylenedivinylene)bis-8-hydroxyquinoline (9) and metal complexes of 9, Al(PHQ) (10) and Zn(PHQ) (11), have been synthesized and characterized. The crystal structure of 6 was determined. Light emitting properties of the prepared compounds have been investigated. 1 produces an orange-yellow emission (λmax=575nm). The cation, 6, gives a red emission (λmax=607nm), which is shifted 32 nm to the red compared to 1.8 produces a yellow emission (λmax=567nm). The metal complex 10 gives a red emission (λmax=610nm), which is a red shift of 43 nm compared to 8. The change in structure in the prepared compound caused a change in the electron distribution in the compounds, which induces a large wavelength shift of the emitted-light. Thermal analysis showed that the decomposition temperatures of the metal complexes (10, 11) were higher than those for the smaller organic molecular compounds (1-9). Therefore, metal complexes (10, 11) can be used as EL materials over a larger temperature range.     

Quantum chemical studies on tuning the second-order nonlinear optical molecular switching of triarylborane derivatives

In this work, density functional theory (DFT) combined with the finite field (FF) method has been adopted to analyze the second-order nonlinear optical (NLO) properties of the triarylborane (TAB) derivatives obtained by introducing different inductive electron groups into the phenylene ring of the TAB (RTAB, where R=2-C6H5-C2B10H10(1),R=F(2), R=Me(3),R=NO2(4),R=NH2(5)). The static first hyperpolarizabilities (βtot) of the RTAB molecules can be switched by binding one F- to the boron center (RTAB′) or one-electron reduction (RTAB"). The DFT-FF calculations show that the βtot values of 2′, 3′ and 5′ decrease while those of 1′ and 4′ increase compared with the values of their neutral molecules, which was attributed to the fact that the charge transfers of 2, 3 and 5 become smaller and those of 1 and 4 become larger by binding one F- ion to the boron center, according to time-domain DFT (TD-DFT) analysis. However, the incorporation of one electron enhances the second-order NLO properties of the RTAB molecules remarkably, especially for system 1. It is notable that the βtot value of reduced form 1″ is 508.69×10-30 esu, i.e. about 578 times larger than that of system 1. Frontier molecular orbital (FMO) and natural bond orbital (NBO) analyses suggest that the reversal of the charge distribution between the neutral molecules and their reduced forms leads to low HOMO-LUMO energy gaps (E0) and thus large βtot values for the reduced forms.     

Discovery of C<Subscript>4</Subscript> species at high altitude in Qinghai-Tibetan Plateau

Plant specimens are collected from the areas between latitude 27°?2′N and 40°57′N, and longitude 88°93°E and 103°24′E, with an altitudinal range from 2210 to 5050 m above the sea level in Qinghai-Tibetan Plateau. The stable carbon isotope analysis indicates that two of Chenopodiaceae and six of Poaceae in the samples are C4 plants. Four of the C4 plants are found in 11 spots with altitudes above 3800 m, and Pennisetum centrasiaticum, Arundinella yunnanensis and Orinus thoroldii are present in six spots above 4000 m, even up to 4520 m. At low CO2 partial pressure, that sufficient energy of high light improving C4 plant's tolerance of low temperature and precipitations concentrating in growing season probably are favorable for C4 plants growing at high altitude in Qinghai-Tibetan Plateau.     

Photoelectrical performance of nanocrystalline TiO2 film electrode sensitized by Ru(II)-bipyridine complexes

Two kinds of Ru(II)-bipyridine complexes,cis-di(thiocyanate)bis(2,2′-bipyridyl-4,4′-dicarboxylate) ruthenium(II) andcis-di(thiocyanate)bis(2, 2′-bipyridyl-3, 3′-dicarboxylate) ruthenium(II), were utilized as the sensitizers to the nanocrystalline TiO₂ film electrodes. Study shows that the two dyes have quite different sensitization properties due to the strong steric effect of carboxyl groups. In addition, the pretreatment to nanocrystalline TiO₂ film electrodes with TiCl₄ was investigated, which is an effective way to improve the photoelectric conversion performances of sensitized TiO₂ electrodes.     

Enhanced hydrosen production by insertional inactivation of adhE gene in Klebsiella oxytoca HP1

Ethanol is the main byproduct of anaerobic H2-producing fermentation in Klebsiella oxytoca HP1. Two moles of NAD（P）H are consumed to yield one mole of ethanol that may decrease bacterial hydrogen production. In this article the adhE gene that codes for acetaldehyde dehydrogenase was disrupted for the first time. A homologous recombination vector pTA-Str was constructed in which the adhE gene was disrupted by inserting an aminoglycoside-3＇-adenyltransferase （aadA） gene. As expected, the vector includes the insertion 5＇-adhE-aadA-adhE-3＇. The amplified DNA fragment 5＇-adhE-aadA-adhE-3＇ from pTA-Str was transformed into K. oxytoca HP1 and one recombinant was obtained. PCR analysis of the resulting genomic DNA indicated the appropriate deletion and insertion. Compared with the H2-production of wild type K. oxytoca HP1, the hydrogen yield of the mutant increased by 16.07% and ethanol concentration decreased by 77.47%, suggesting that inactivation of the adhE gene in K. oxytoca HP1 is a potential method for enhancing bacterial H2-production.     

QSPR between Physical-Chemical Properties and Molecule Parameters of Alkanes

A set of molecule parameters, namely, N, N′, p, q, n, were used to express the structures of alkanes. A correlative model was established between certain physical-chemical properties and molecular parameters of alkanes by regression method. Eight physical-chemical properties, such as evaporation heat （△vHm^20）, density（D^20 ）, capacity （C^20）, surface tension （δ^20）, boiling point （Tb）, critical temperature（Tc）, critical pressure（Pc） and critical volume（Vc）, of fifty-six C3-C16 alkanes were calculated directly from the model in this paper. The calculated values are in good accordance with the literature ones reported for alkanes, and the correlation coefficients （R） equal or exceed 0.99 . The research results indicate that the principle of the method is simple and clear, the method is practical, the correlativity is excellent, and the predicted data are credible.     

Formate and acetate as recorded in a mid－latitude glacier in west China

Formic (HCOOH) and acetic (CH3COOH) acids are the chief carboxylic compounds in the troposphere[1]. Although weak acids, they contribute significantly to the free acidity, ionic balance of precipitation and the chemical reactions in the atmosphere, especially in the remote areas[2—4]. General sources for formate and acetate have been identified in the past 3 decades although a satisfactory source attribution is lacking to explain atmospheric observations[5]. Possible sources include veget…