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The cycloaddition mechanisms of CO2 and epichlorohydrin catalyzed by salophen as an organocatalyst were investigated using B3LYP density functional theory computations. The kinetically most favored neutral pathway involves a concerted and synergistic mechanism of phenolate as a nucleophile and phenol as a H-bonding donor in epoxide ring opening and CO2 addition. The computed apparent barrier (33 kcal mol−1) is in line with the reaction conditions (120 °C and 10 bar CO2). A similar and anionic route with a much lower apparent barrier (17 kcal mol−1) to react under milder conditions has been proposed and this has to be proven experimentally.

To understand the relationship between soil fauna and microorganism in the detrital food chain during litter decomposition, leaf litters of poplar (Populus simonii) and fargesia (Fargesia spathacea) in a subalpine forest of western Sichuan were taken as study objects. Phospholipid fatty acid (PLFAs) biomarker method was used to determine the effects of soil fauna on the abundance, structure and diversity of microbial community during the decomposition of leaf litter of two species from April 2016 to April 2018 with in situ control experiment. The results showed that the presence of soil fauna significantly affected the microbial PLFAs content during the decomposition of both species, reducing the PLFAs content in the first 240 days and increasing the PLFAs content in the 360 to 480 days. Soil fauna participation reduced the ratio of fungi to bacteria in the decomposition of poplar litter, and increased the ratio of gram-positive bacteria (G为了解凋落物分解过程中碎屑食物链土壤动物与微生物的相互联系,本研究以川西亚高山森林杨树和箭竹凋落叶为对象,通过原位控制试验,于2016年4月至2018年4月采用磷脂脂肪酸(PLFAs)生物标记法,研究了土壤动物对两种凋落叶分解过程中微生物丰度、群落结构和多样性的影响.结果表明: 土壤动物的参与显著影响两个树种凋落叶分解过程中微生物PLFAs含量,降低了分解前240天的PLFAs含量,增加了分解360~480 d的PLFAs含量;土壤动物的参与降低了杨树分解过程中的真菌/细菌比值,增加了革兰氏阳性菌(G

UB3LYP computation including dispersion and toluene solvation has been carried to elucidate the mechanisms of alkene hydrogenation catalyzed by bis(imino)pyridine iron dinitrogen complex (iPrPDI)Fe(N2)2, which has low stability towards N2 dissociation. The coordinatively unsaturated complexes, (iPrPDI)Fe(N2) and (iPrPDI)Fe(1-C4H8), favor open-shell singlet ground states. On the basis of our computations, we propose a new mechanism of 1-butene coordination and hydrogenation after N2 dissociation. The hydrogenation of 1-butene undergoes a concerted open-shell singlet transition state involving H2 dissociation, C-H bond formation and C=C bond elongation, as well as the subsequent C-H reductive elimination. In the whole alkene hydrogenation, the H-H bond cleavage is the rate-determining step.

The hydrosilylation of alkenes catalyzed by Fe(CO) 5 is an intricate process involving formation of alkylsilane, vinylsilane, and alkane. Herein, we represent a computational study of this reaction to determine the underlying reaction mechanism using density functional theory (DFT) techniques. On the basis of an extensive exploration of the potential energy surfaces, the modified Chalk–Harrod mechanism was found to be competitive with the Chalk–Harrod mechanism in the stoichiometric reaction of ethylene and trimethylsilane. The source of product selectivity was predicted to be determined by the relative stability of transition state TS(4b–5b) , which is for the ethylene-insertion into Fe Si bond from (H)(Me 3 Si)Fe(CO) 3 (C 2 H 4 ) to (H)(C 2 H 4 SiMe)Fe(CO) 3 , and TS(5a–7a 1 ) for the conversion of ethylene hydrometallation product (Me 3 Si)Fe(CO) 3 (η 2 -H)(C 2 H 4 ) to (C 2 H 5 )(Me 3 Si)Fe(CO) 4 . The relative free energy difference of 3.27 kcal/mol between these two transition states gives a percentage ratio of 79:21 for C 2 H 5 SiMe 3 to C 2 H 4 SiMe 3 , which is qualitatively in agreement with the experimental observations. The largely excessive ethylene favors not only the formation of Fe(CO) 3 (C 2 H 4 )(H)(SiMe 3 ) 4b but also the release of vinylsilane from Fe(CO) 3 (H 2 )(C 2 H 3 SiMe 3 ) or Fe(CO) 4 (C 2 H 3 SiMe 3 ) via the addition of another ethylene molecular to the metal center. Alternatively, in the presence of excessive R 3 SiH, species Fe(CO) 4 (H)(SiR 3 ) will be dominate over Fe(CO) 4 (C 2 H 4 ). In the catalytic process, Fe(CO) 4 (H)(SiR 3 ) plays the main role of active species. The experimental findings were rationalized in terms of two reaction pathways, the accessibility of which depended on the ratio of silane/alkene.

As a biocide to reduce soil and litter faunal populations in field experiments, naphthalene has been widely used in the study of ecological functions of soil fauna, but the non-target effects of naphthalene bring about enormous uncertainty to its application. In order to understand whether there were non-target effects of naphthalene in subalpine forest soil, soil in the subalpine forests of west Qinghai-Tibet Plateau was taken as study object. The short-term responses of soil respiration rate, nutrient content and enzyme activity to naphthalene were studied in microcosms. The results showed that soil respiration rate was significantly suppressed by application of naphthalene within 0-10 days, and then showed a significant promotion effect. Naphthalene significantly affected the dynamics of soil NH萘作为土壤动物化学抑制剂已在土壤动物生态功能的研究中广泛使用,但其非目标效应使其应用仍存在很大的不确定性.为了了解在亚高山森林土壤应用萘抑制土壤动物群落是否存在非目标效应,以青藏高原东缘的川西亚高山森林土壤为研究对象,采用微缩试验研究了萘对土壤呼吸速率、养分含量和酶活性的短期影响.结果表明: 萘处理显著抑制了培养0～10 d的土壤呼吸速率,随后(24～52 d)表现出明显的促进作用.萘处理显著影响了土壤铵态氮和硝态氮含量的动态变化,萘处理铵态氮和硝态氮含量分别以培养的3和17 d最高,对照则以培养的45 d和结束时的52 d最高.萘处理土壤可溶性碳含量在培养3 d急剧增加后迅速降低,对照则略有升高后降低,而萘处理和对照的可溶性氮含量均表现为先升高后降低.萘处理和对照的土壤酶活性均具相似的动态规律,两者的脲酶、硝酸还原酶和亚硝酸还原酶活性分别在培养45、38和10 d至最高.萘处理和采样时间的交互作用显著影响了土壤呼吸速率,以及土壤铵态氮、硝态氮和可溶性氮含量,但对可溶性碳含量、蔗糖酶、硝酸还原酶和亚硝酸还原酶活性的影响不显著.萘作为驱虫剂的非目标效应可能在短期内对川西亚高山森林土壤的氮循环过程产生强烈的影响.

The effects of naphthalene on soil respiration, dissolved organic matter and microbial biomass, and its inhibition efficiency for soil fauna of subalpine forest in western Sichuan were studied by in situ control experiment. The results showed that naphthalene application significantly inhibited the individual density and group number of soil macro- and meso-/micro- arthropods, with the individual density being decreased by 76.3%-78.5% and 83.3%-84.8% respectively, and the number of groups being decreased by 48.3%-56.1% and 45.8%-58.3%, respectively. The seasonal dynamics of soil respiration rate showed single peak curves in both naphthalene treatment and control. The lowest and the highest soil respiration rates were observed in February and August, respectively. The naphthalene treatment had little effect on soil respiration. Compared with the control, naphthalene treatment significantly reduced the contents of soil dissolved carbon and dissolved nitrogen in August and October as well as microbial biomass carbon (MBC) in April and August, but increased MBC/MBN in April. The naphthalene treatment and sampling time significantly interacted to affect the MBC and MBN, but had no significant effect on individual density, the number of groups of soil fauna and DC content. In all, naphthalene as biocide could effectively inhibit the soil arthropods and had no significant effect on soil respiration, but it had varying degrees of effects on soil carbon and nitrogen components in subalpine forest of western Sichuan.通过原位控制试验,研究了萘对川西亚高山森林土壤动物抑制效率、土壤呼吸、可溶性有机质和微生物生物量的影响.结果表明: 萘施用显著抑制了大型和中小型土壤节肢动物的个体密度和类群数量,个体密度分别下降76.3%～78.5%和83.3%～84.8%,类群数量分别降低48.3%～56.1%和45.8%～58.3%.萘处理与对照的土壤呼吸速率季节动态呈单峰曲线,分别以2月和8月为最低值和最高值,而且未受萘施用的显著影响.与对照相比,萘处理显著降低了8月和10月土壤可溶性碳和可溶性氮含量,以及4月和8月微生物生物量碳,增加了4月的微生物生物量碳氮比.萘处理和采样时间的交互作用显著影响了微生物生物量碳和微生物生物量氮,但对土壤动物个体密度和类群数量以及可溶性碳含量影响不显著.总体上,萘作为抑制剂,在川西亚高山森林土壤能够有效地抑制土壤动物节肢动物,且并未显著影响土壤呼吸,但对土壤碳氮组分造成了不同程度的影响.

Although a variety of functional metal-organic frameworks (MOFs) have been synthesized, post-modified, and applied in various areas, there is little knowledge about how molecular cluster building units are stepwise evolved into MOFs via intermediates. Coordination bonds are generally stronger than hydrogen bonds, and thus equivalent replacement of X-H···Y hydrogen bonds by X-M-Y coordination bonds can transform hydrogen bond networks into MOFs. In this work, solvothermal in situ reduction reactions of CuBr2 and 1,4-diazoniabicyclo[2,2,2]octane (DABCO) generated a myriad of tunable photoluminescent cuprous body-centered cubic bromide cluster-based networks with the general formula [Cu4+xH4-xBr6(DABCO)4](HCO2)2·S (x = 0, 0.56, 0.81, 1.27, 1.39, 2.56, 2.78, and 4 for compounds 1-8, respectively). All of these compounds crystallize in the cubic space group with the largest volume difference being only 5.2%, but they belong to three remarkably different kinds of crystals. Complex 1 is a molecular crystal and consists of tetrahedral [Cu4Br6(HDABCO)4](2+) clusters with monodentate HDABCO groups that are supported via N-H···Br synthons in the hydrogen bond network. Compound 8 is a [Cu8Br6](2+) cube cluster-based MOF with bridged DABCO ligands. Complexes 2-7 are seemingly impossible Cu/H-substituted solid solutions of 1 and 8. The CuBr framework components in 1-8 are Cu4Br6, Cu4.56Br6, Cu4.81Br6, Cu5.27Br6, Cu5.39Br6, Cu6.56Br6, Cu6.78Br6, and Cu8Br6, respectively. Crystallization kinetics studies revealed that the [Cu4Br6(HDABCO)4](2+) cluster-based hydrogen bond network (1) was initially formed such that N-H···Br hydrogen bonds could be stepwise replaced by N-Cu-Br coordination bonds to form the [Cu8Br6](2+) cube cluster-based MOF (8) via solid solutions. These observations directly reveal the equivalence and transformation between the N-H···Br hydrogen bond and the N-Cu-Br coordination bond and the evolutionary mechanism of a molecular crystal to a MOF via solid solutions, which is of fundamental importance in materials but has never before been revealed. DFT calculations suggest that equivalent replacement of a N-H···Br hydrogen bond by a N-Cu-Br coordination bond is exothermic and exergonic, which also supports the transformation from molecule 1 to MOF 8.

Density functional theory (DFT) calculations have been conducted to gain insights into the mechanism and chemoselectivity of the Ni(0)-mediated carboxylation reactions of benzylidenecyclopropane with CO2. The experimentally observed selectivity of reaction products may be explained through the formation of a common π-complex Ni(L)2(η2-C2H4C CHPh), which can undergo a direct nucleophilic cyclic addition with CO2 or an isomerization to four-membered nickelacycle complex followed by the CO2 insertion. All possible pathways to afford the product precursor five/six-membered cyclic Ni–carboxylates species are examined, and their corresponding energetics are demonstrated. Among the various reaction pathways, we have found that the formation of five-membered cyclic Ni–carboxylate (2) via the bisligand route IA, leading to the target product cyclopropane derivative A, has a lower reaction barrier and is the most preferred in the polarity weaker solvent (toluene), which is very in good agreement with the experimental finding. As for the formation process of six-membered cyclic Ni–carboxylates (4 and 5), the rate-determining step is associated with the ring-opening of benzylidenecyclopropane to give a four-membered metallacyclic intermediate. In acetonitrile and using DBU as ligands, the monoligand route IIB is competitive with the bisligand route IIB because the activation barrier difference for the ring-opening benzylidenecyclopropane is small (1.34 kcal/mol) and the energy barrier of CO2 insertion into the Ni C(sp2) bond is lower. The monoligand cyclic Ni–carboxylate 4B′d, generated from the CO2 insertion into the Ni C(sp2) bond of the proposed four-membered intermediate 2B′d, is predicted to be the most probable species leading to the branched α,β-unsaturated ester B.

A computational study with the Becke3LYP DFT functional theory was carried out on Cu(I)-mediated domino reaction of asymmetrical alkynes with CO2 by the reducing reagent of hydrosilane. We studied the mechanism for the entire reaction and the selectivity-determining step in order to understand the regioselectivity. Coupling of alkyne with LCuH (L = N-heterocyclic carbene) is computed to be the selectivity-determining step, though not the rate-determining step. The steric and electronic factors that determine the regioselectivity have been discussed. The calculations show that the electronic factors are not the sole reason for the observed regioselectivity. The observed regioselectivity is dominated by both electronic factors and steric factors. Furthermore, the computational results are in good agreement with the experimental results.

Using the B3LYP density functional theory method we have computed the potential energy surface of the (η 5 -C 5 H 5 )Ir-catalyzed acetylene cyclotrimerization. The first step is the oxidative addition which forms the iridacyclopentadiene complex ( 2 ) from the bisacetylene complex (η 5 -C 5 H 5 )Ir(η 2 -HCCH) 2 ( 1 ), and this is the rate-determining step. On the potential energy surface, acetylene addition to complex ( 2 ) forms the iridacyclopentadiene(acetylene) complex ( 3 ), and this step is barrier-free and highly exergonic; and complex ( 3 ) forms the benzene complex ( 4 ) via an intramolecular [4 + 2] cycloaddition. Alternatively, complex ( 2 ) and acetylene form the iridabicyclo[3.2.0]heptatriene complex ( 5 ) via an intermolecular [2 + 2] cycloaddition, and complex ( 5 ) can further isomerize into the aromatic iridacycloheptatriene complex ( 6a ), which is a trap on the potential energy surface. This potential energy surface is qualitatively close to that for the CpRh-catalyzed reaction, but differs strongly from that for the CpCo-catalyzed reaction, which undergoes a spin crossing (or non-adiabatic) mechanism. The differences among these mechanisms as well as the relative stability of their intermediates have been compared and discussed accordingly.

Calculated attraction: Trans-linear and cis-angular [N]ferrocenylenes, as well as cyclo[10]ferrocenylene, higher homologues of biferrocenylene, and analogues of [N]phenylenes, are demonstrated as strain-free.

An finite element model of orthogonal dry cutting with separate line is established according to the constitutive relation of large thermo-elastic-plastic displacement and the principle of virtual work in metal plastic deformation process,. The influence of cutting depth on residual stress was simulated for materials GH4169 with high speed. The residual stresses are analyzed on the machined surface and subsurface. The result shows that tensile residual stress of the machined surface is minimum value when the cutting depth is 0.2mm. the deeper is the depth of cut, the large the augmentation of compressive stress on the subsurface, which proves foundation for cutting process of dry-machined difficult-to-machine material with high speed and make it more efficiently to control the integrity of the machined surface.

The wear resistance of coated tool can be predicted widely by experiments and theoretical analysis. In the paper, an unique method is adopted to analyze influence of high speed on key stresses of the coated tool .First, through the cutting process simulation with different high cutting speeds, contact stress, shear stress and temperature distribution of the surface of the coated tool can be obtained when the cutting process is steady. Then the stresses and temperature are applied to the coated tool to analyze the key stresses in the tool. The result shows the potential failure of coated tool can be predicted by Finite element analysis correctly. Crack between coating and substrate may occur at the same position with different cutting speeds.

In this paper, the elasto-plastic dynamic analysis on the steel spatial arch truss with 120m span and 0.1 rise-span ratio is carried out under with SAP2000. The plasticity development level and failure mode of the structure are estimated by the method of increasing the peak acceleration gradually and the plastic hinge theory. The results show that the structure displacement response changed nonlinearly with the increased peak acceleration of the earthquake; Its critical peak acceleration of EL earthquake wave when applied in horizontal direction is 222gal, and is 274gal when applied in vertical direction; The ratio of its maximal node horizontal and its structural height is 1/783 when EL-Centro waves applied on structure in horizontal direction; The ratio of its maximal node vertical and its structural span is 1/751, when EL-Centro waves applied in vertical direction; The failure mode of the truss under the earthquake action is elasto-plastic dynamic buckling.

The chemical fixation of carbon dioxide with 2,3-epoxypropyl phenyl ether catalyzed by LiBr salt to produce a five-membered cyclic carbonate, 4-(phenoxymethyl)-1,3-dioxolan-2-one, has been extensively investigated at the B3LYP density functional level of theory. The solvent effects have been studied by means of a PCM model. All possible pathways are examined, and their corresponding energetics are demonstrated. Our results reveal that the overall reaction comprises three main steps: epoxide ring-opening, carbon dioxide insertion, and ring-closure of cyclic carbonate, none of which contains significantly large barriers. On the basis of the computed free energies of activation, the rate-determining step can be the ring-opening of epoxide or the ring-closure of cyclic carbonate with variation in the reaction conditions in N-methylpyrrolidinone (NMP) solvent. Our calculations indicate that path 2 is more favorable than path 1 in the gas phase, while both of them exist possibly in NMP solvent. The overall reaction is exothermic. Furthermore, the free energy profiles of all reaction pathways along the minima energy path in the gas phase and in NMP solvent were obtained and compared. It is shown that NMP solvent does not change the general trends for the reaction potential energy surfaces.

The detailed mechanism of the experimentally observed formation of five-membered cyclic carbonates in the coupling reaction between chloromethyloxirane and CO2 catalyzed by the Re(CO)5Br complex is revealed by means of density functional theory (DFT) calculations. All possible pathways are examined, and their corresponding energetics are demonstrated. Our calculations indicate that the real active catalyst is the unsaturated complex Re(CO)4Br rather than free radical species (Re(CO)5 or Br radicals). The preferred mechanism (path I) for the catalytic production of cyclic carbonates can be divided into three main stages involving epoxide oxidative addition, carbon dioxide insertion, and reductive elimination of cyclic carbonate, none of which contains significantly large barriers. Our results provide support for Jiang’s proposal that the reaction proceeds through the reactive oxametallacyclobutane 2b. Furthermore, we have found CO dissociation from 2b is an essential step, which facilitates CO2 coordinatio...

Solvothermal treatment of copper halides and 3-amino-5-mercapto-1,2,4-triazole (H2amtz) produced three isostructural complexes [Cu31X4(H1.55amtz)24](SO4)8·xDMF [X = Cl, Br and I, x ∼ 32], which show 3-D networks with bor topology constructed by Cu-centered CuCu4 tetrahedra and CuCu3 triangles with an acentric cubic superlarge cell.

The mechanism of the Ni-mediated coupling reaction of CO 2 with epoxyethane has been extensively investigated by the density functional theory (DFT) calculations. All the possible pathways are examined, and their corresponding energetics are demonstrated. On the basis of the comparison of three mechanisms, it is determined that the preferred mechanism for the catalytic production of cyclic carbonate can be divided into three main steps involving epoxide oxidative addition, carbon dioxide insertion, and reductive elimination of cyclic carbonate (route I C ), none of which contains significantly large barriers. The overall reaction is exothermic and the rate-determining step is associated with the reductive elimination of cyclic carbonate from the six-membered metallacyclic intermediate 15 . All reaction pathways with solvent effects taken into consideration have been studied by means of a PCM-UAHF model. The calculations indicate that the introduction of solvent effects does not change the general trends for the reaction potential energy surfaces. Our results provide a theoretical support for the reaction mechanism proposed from previous experimental observations. At the same time, the present theoretical study gives a clear profile for the cycloaddition of carbon dioxide with epoxyethane promoted by (Ph 3 P) 2 Ni.

In adipose tissue of rats on long-term high fat diet, the inflammatory changes the roles of angiotensin receptor blocker (ARB) in pimelitis and insulin resistance (IR) were observed. IR rat model was established by feeding high calorie and high fat diet. The change in insulin sensitivity was detected by euglycemic-hyperinsulinemic clamp technique 8 weeks after intervention by valsartan. The expression levels of CD68 and MCP-1 mRNA and proteins in adipose tissue were examined by RT-PCR and immunohistochemistry respectively. The parameters of blood glucose, insulin and blood lipid were analyzed. The results showed that in high fat diet group intra-abdominal obesity developed, the content of visceral fat and the number of inflammatory cells in local adipose tissue were significantly increased (P

The equilibrium geometries, electronic states, vibrational frequencies and energies of (GaP) n and (GaP) n − ( n = 7–9) have been calculated by hybrid B3LYP and B3PW91 functionals at 6-31+G(d) level. The results reveal that the lowest lying electronic states’ geometries of the neutral have the same molecular symmetry as the corresponding anions’. (GaP) 7 is shown to have a singlet ground state ( 1 A 1 ) with C 3v symmetry. (GaP) 8 is found to be a closed-shell molecule with S 4 symmetry. (GaP) 9 takes on a singlet ground state ( 1 A′) with C 3v symmetry. The charge-induced structural changes in these clusters have been discussed. Moreover, natural bond orbital (NBO) analysis implemented to gain insight into the bonding pattern of these clusters indicates these clusters have a partial ionic character. Natural electron configuration shows the extra electron is mostly localized on the metal atoms. In addition, three types of energy separations reported in this work are the adiabatic electron affinity (AEA), the vertical detachment energy (VDE), and the vertical electron affinity (VEA). Herein, adiabatic electron affinities (AEAs) and vertical detachment energies (VDEs) for all of interest are excellent consistent with experiments, as strongly supports the optimized structures. And the order of AEAs and VDEs of the (GaP) n − are both (GaP) 9 8 7 . (GaP) 9 exhibits the lowest adiabatic electron affinity of all the clusters studied, indicating a particularly stable neutral species.

The cycloaddition of CO2 to epoxides, catalyzed by Mg(TPP)/TBAI (TPP = tetraphenylporphyrin; TBAI = tetrabutylammonium iodide), was investigated using DFT methods. Epoxides with various substituents were studied to explore steric and electronic effects on the reaction mechanism. Computational results show that the cycloaddition proceeds according to a much easier mechanism in the presence of Mg(TPP) and TBAI than the mechanism that takes place when Mg(TPP) is used as the catalyst. A preference for the epoxide ring-opening to occur at the methine (Cα) or methylene (Cβ) carbon was noted. The ring-closing step leading to the formation of a five-membered carbonate is predicted to determine the reaction rate. For alkyl-substituted epoxides, the β pathway is favorable since steric factors are dominant; for epoxides with a strongly electron-donating group and styrene oxide, the reaction is mainly controlled by electronic factors and proceeds along the α pathway. When the epoxide has a strongly electron-withdrawing group (CF3), both steric and electronic effects play important roles. The calculated reactivity of epoxides with CO2 catalyzed by Mg(TPP)/TBAI is in good agreement with that observed experimentally.

Hydrothermal reaction of CuBr2, 4,4′-bipyridine and ethanol/methanol generated two copper (I) bromide complexes with in situ alkylated 4,4′-bipyridium, namely [C14H18N2][Cu5Br7] (1) and [C12H14N2][Cu4Br6] (2). The structure of 1 consists of Cu 5 Br 7 2 - chains and N,N′-diethyl-4,4′-bipyridinium. The underlying structural motif in Cu 5 Br 7 2 - of 1 is the Cu5Br capped square pyramid, which is different from the Cu5Br2 pentagonal bipyramidal structural motif in various documented Cu 5 Br 7 2 - anions. The Cu 5 Br 7 2 - in 1 contains untypical μ5-bromide, with which five copper atoms forms a capped square pyramid rather than a pentagonal pyramid as predicted by Subramanian and Hoffmann. Compound 2 is isostructural with [C12H14N2][Cu4Cl6] reported by Willett, and consists of Cu 4 Br 6 2 - chains and N,N′-dimethyl-4,4′-bipyridinium. The Cu 4 Br 6 2 - chain is composed of alternating Cu6Br6 and Cu2Br6 units.

The interactions of rhodium complex RhCl(CO)(TPPTS)(2) [TPPTS=P(m-C(6)H(4)SO(3)Na)(3)] with cationic, nonionic, and anionic surfactants have been investigated by UV-vis, fluorescence and (1)H NMR measurements. The presence of four different species of RhCl(CO)(TPPTS)(2) in cationic cetyltrimethylammonium (CTAB) solution has been demonstrated: free rhodium complex, rhodium complex bound to CTAB monomer, rhodium complex bound to CTAB premicelles, rhodium complex bound to CTAB micelles. The spectroscopy data show that RhCl(CO)(TPPTS)(2) can adsorb on the interface of cationic CTAB micelles by strong electrostatic attraction, weakly bind to the nonionic polyoxyethylene (20) sorbitan monolaurate (Tween 20) micelles by hydrophobic interaction, and does not interact with anion sodium dodecyl sulfate (SDS) micelles due to the strong electrostatic repulsion.

Based on the teaching philosophy of “student-centered”, “teacher-led” and “small steps learning”, this paper presents the web-based periodical self-directed learning mode and its framework, especially takes Photoshop image processing teaching website for example, the application procedure of web-based periodical self-directed learning mode is addressed in detail. The results of case evaluations show that the theory, method and experimental procedures are effective.

To investigate the apoptosis versus proliferation activities of pulmonary artery smooth muscle cells (PASMC) in pulmonary hypertension (PH) associated with chronic obstructive pulmonary disease (COPD) and pulmonary vascular structural remodeling.Forty-five patients were divided into three groups: patients without COPD and PH (non-COPD group, n = 15), COPD patients without PH (COPD with non-PH group, n = 15) and patients with PH associated with COPD (COPD with PH group, n = 15). Lung tissue samples were obtained from surgically resected specimens. The remodeling of pulmonary arteries were observed under microscope, and the changes of morphology-the ratio of the thickness of the wall to the external diameter of the pulmonary arterioles (WT%) and the ratio of the area of the wall to that of the pulmonary arterioles (WA%) were analyzed by computer-based image analysis system. The proliferation of PASMC was detected by proliferating cell nuclear antigen (PCNA) with immunohistochemical technique, and TUNEL (terminal deoxynu-cleotidyl transferase (TdT)-mediated deoxyuridine triphosphate (dUTP)-digoxigenin nick end labeling) was used for the detection of the apoptosis of PASMC.In the COPD with non-PH group, the arterial walls were thicker and the lumens narrower than that of the non-COPD group. In the COPD with PH group, the walls were thicker and the lumens narrower than that of the COPD with non-PH group. In the COPD with non-PH group and the COPD with PH group, the WT% and WA% [(20 +/- 4)% and (35 +/- 5)%; (28 +/- 5)% and (50 +/- 6)%, respectively] were higher than those of the non-COPD group (16 +/- 3)% and (25 +/- 3)% (P0.01), and the WT% and WA% of the COPD with PH group were higher than those of the COPD with non-PH group (P0.01). Both proliferative and apoptotic PASMC were found in the patients of the three groups. The proliferation indexes (PI) of the COPD with non-PH group and the COPD with PH group [(19 +/- 5)% and (38 +/- 7)%] were significantly higher than that of the non-COPD group [(8 +/- 2)%, P0.01], while the apoptosis indexes (AI) [(4.5 +/- 1.3)% and (3.1 +/- 1.3)%] were lower than that of the non-COPD group [(6.9 +/- 1.9)%, P0. 01]. The PI of the COPD with non-PH group was lower than that of the COPD with PH group; the AI was higher than that of the COPD with PH group (P0.05). The PaO(2) of the COPD with non-PH group and the COPD with PH group was negatively related with the PI (r = -0.519, P = 0.003), but positively related to the AI of the PASMC (r = 0.441, P = 0.015).The imbalance of the increased proliferation and decreased apoptosis of PASMC may contribute to the pulmonary vascular structural remodeling and pulmonary arterial hypertension in patients of COPD. Hypoxia is one of the main causes of increased proliferation and decreased apoptosis of the PASMC.

Four novel coordination polymers, [Mn2(cptc)(2,2′-bpy)(H2O)]·H2O (1), [Mn2(cptc)(phen)(H2O)]·H2O (2), Mn4(cptc)2(phen)4(H2O)2]·3H2O (3) and [Cd2(cptc)(H2O)3] (4) (H4cptc = cyclopentane-1,2,3,4-tetracarboxylic acid, 2,2′-bpy = 2,2′-bipyridine, phen = 1,10-phenanthroline), have been synthesized by hydrothermal reactions of flexible (1S,2S,3R,4R)-H4cptc with MnCl2/CdCl2. By breaking the mirror plane of symmetry, the meso-cptc ligand is successfully converted into two pairs of enantiomers, the (1R,2S,3S,4R)- and (1S,2R,3R,4S)-cptc groups in 1–3 are unprecedented while the documented (1R,2R,3R,4S)- and (1S,2S,3S,4R)-cptc enantiomers exhibit an unprecedented μ6-mode in 4. Layered 1 and 2 show similar structures and are constructed by centrosymmetric tetranuclear units. 3 is a binodal (3,4)-connected layer with Schlafli symbols of (53)2(54·82), in which cptc exhibits two types of μ5-mode bonding. 4 has a 3-D pillar layered structure composed of neutral [Cd(cptc)]n layers and octahedral CdO6 pillars. The presence probability of different enantiomers is in agreement with the relative stability of different conformations of cptc calculated by time-dependent density functional theory (TD-DFT).