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Pd-based hollow catalysts, Pd@HMAN, in which Pd was used as core and hollow aluminosilicate (HMAN) as shell, have been successfully synthesized by self-assembling method. Pd@HMAN-M (M = 1, 1.5, 2, 2.5) with uniform Pd nanoparticle size (~ 9.3 nm) and different shell volume (0.06–0.18 cm3g−1) were prepared by varying the addition amount of tetraethyl orthosilicate (TEOS). It is found that the shell pore size of 1–3.5 nm of the catalysts Pd@HMAN-M was conducive to the mass transfer of H2, O2 and H2O2, and the larger the shell pore volume of Pd@HMAN-M was, the larger the adsorption amount of reactant H2 was, and thus the higher selective and productive of H2O2 could be obtained. The catalyst Pd@HMAN-1.5 had the highest H2O2 selectivity (81%) and productivity (795 mmol gPd−1 h−1) at atmospheric pressure due to its most substantial shell pore volume of (0.18 cm3g−1) and H2 adsorption amount.

Hepatitis B (HB) is a globally prevalent infectious disease caused by the HB virus. Xiaochaihu decoction (XCHD) is a classic herbal formula with a long history of clinical application in treating HB. Although the anti-HB activity of XCHD has been reported, systematic research on the exact mechanism of action is lacking. Here, a network pharmacology-based approach was used to predict the active components, important targets, and potential mechanism of XCHD in HB treatment. Investigation included drug-likeness evaluation; absorption, distribution, metabolism, and elimination (ADME) screening; protein-protein interaction (PPI) network construction and cluster analysis; Gene Ontology (GO) analysis; and Kyoto Encyclopedia of Genes and Genomes (KEGG) annotation. Molecular docking was adopted to investigate the interaction between important target proteins and active components. Eighty-seven active components of XCHD and 155 anti-HB targets were selected for further analysis. The GO enrichment and similarity analysis results indicated that XCHD might perform similar or the same GO functions. Glycyrrhizae Radix (GR), one of the seven XCHD herbs, likely exerts some unique GO functions such as the regulation of interleukin-12 production, positive regulation of interleukin-1 beta secretion, and regulation of the I-kappaB/NF-kappaB complex. The PPI network and KEGG pathway analysis results showed that XCHD affects HB mainly through modulating pathways related to viral infection, immunity, cancer, signal transduction, and metabolism. Additionally, molecular docking verified that the active compounds (quercetin, chrysin, and capsaicin) could bind with the key targets. This work systematically explored the anti-HB mechanism of XCHD and provides a novel perspective for future pharmacological research.

Chemical looping combustion (CLC) is a promising technology to capture CO2. However, the low conversion efficiency of fuel is the key challenge for the in situ gasification CLC with natural iron ore as an oxygen carrier. The reactivity of the selected 6% K2CO3-modified iron ore (6KMIO) was first determined by H2 and CO in TGA, and an enhanced reduction reactivity of 6KMIO was confirmed. Afterward, the feasibility of 6MKIO for coal CLC was tested in a 1 kW continuous reactor. The continuous reactor could be stably operated without any tendency of agglomeration or sintering among 6KMIO particles. Compared with use of the raw iron ore, the use of 6KMIO enhanced the coal conversion and the gasification-products conversion, promoting the CO2 capture efficiency. Furthermore, the mechanism of the catalyzed coal CLC process and the release of sulfur was explored.

Molasses is generally used as a grinding aid in cement and as a water reducer and retarder in concrete. In China, the output primarily consists of sugarcane molasses. In this paper, the effects of sugarcane molasses on the physical performance and hydration chemistry of conventional Portland cement were investigated. The setting times, the normal consistency of cement pastes, the compressive strengths and fluidities of the mortars were respectively determined according to Chinese Standard GB/T 1346, GB/T17671 and GB/T 2419. The effect of molasses on the hydration kinetics of cement was investigated using a calorimeter. The hydration products and pore size distribution of the cement pastes were analysed by X-ray powder diffraction, differential scanning calorimetry and a mercury injection apparatus. The results show that a small amount of sugarcane molasses retards the setting and hardening of cement paste and increases the fluidity of cement mortar, while excess molasses accelerates the setting and hardening. Molasses improves significantly the compressive strength at 3d due to the decrease of porosity. The addition of 1.0 % molasses accelerates the formation of ettringite, prevents the second hydration of aluminate phase and delays the hydration of C3S.

A RP-high-performance liquid chromatography (HPLC) method was developed for quality control of Chinese propolis by simultaneous analysis of 12 flavonoids and 8 phenolic acids. The results showed that vanillic acid, rutin, myricetin, and luteolin were not detected in all of the analyzed propolis and poplar tree gum samples. The caffeic acid, ferulic acid and p-coumaric acid were not detected in poplar tree gum but were detected in propolis, which suggest that they are practical indexes of distinguishing propolis from poplar tree gum. The flavonoid profiles of poplar tree gum were found to be similar to those of propolis, which are dominated by pinobanksin, pinocembrin, 3-O-acetylpinobanksin, chrysin, and galangin. Therefore, the proposed method could be applied to exclude poplar tree gum from propolis with cafferic acid, ferulic acid, and p-coumaric acid as qualitative markers, and distinguish poplar source resin from other illegal substances, and evaluate the quality grading of poplar-type propolis with pinobanksin, pinocembrin, 3-O-acetylpinobanksin, chrysin, and galangin as qualitative and quantitative markers.

In this paper, design, fabrication and measurements of a novel single-pole-double-throw three-state RF MEMS switch based on silicon substrate are presented. The RF MEMS switch consists of two UV-shaped beam push–pull thermal actuators which have three states of ON, OFF and Deep-OFF by using current actuation. When the switch is at Deep-OFF state, it can provide a higher isolation. The switch is fabricated by MetalMUMPs process. The measurement results show that, to the proposed single-pole-double-throw RF MEMS switch, when Switch I is at the ON state and Switch II is at the OFF state, the return loss is better than −16 dB, the insertion loss of Port1 and Port2 is less than −0.9 dB and the isolation of Port3 and Port1 is better than −22 dB at the frequency range from 8 GHz to 12 GHz. When Switch I is at the ON state and the actuator of Switch II is pulled back, which is called the Deep-OFF state, the return loss of Port1 is better than −15.5 dB, the insertion loss of Port1 and Port2 is better than −0.8 dB, and the isolation of Port3 and Port1 is better than −23.5 dB can be achieved at the frequency range from 8 GHz to 12 GHz.

The androgen receptor(AR) signaling activated by dihydrotestosterone(DHT) plays critical roles in prostate cancer development and progression. Phytoestrogens, which are diphenolic compounds with estrogen and antiestrogen effects, can bind to estrogen receptors. However, their function on AR signaling has not been fully elucidated. In this study, dual-luciferase reporter assay, immunobloting, docking system test, MTT assay, immunofluorescence and chromatin immunoprecipitation(ChIP) assays were employed to examine the potential effects of three phytoestrogens(genistein, daidzein, flavone) on DHT-activated prostate specific antigen(PSA) activation, cell proliferation and AR transactivation in lymph node carcinoma of prostate(LNCaP) cells. Phytoestrogens were detected to down-regulate DHT-activated AR-mediated PSA promoter transactivation by dual-luciferase reporter system. Furthermore, three phytoestrogens, especially genistein, were demonstrated to significantly decrease AR-activated PSA protein expression by Western blotting analysis. MTT experiment proves that phytoestrogens, especially genistein, remarkably inhibits the DHT-induced cell proliferation in LNCaP cells. To provide reasonable explanations for experimental phenomena mentioned above, we did docking system test and detected phytoestrogens to share the same AR-binding site with DHT. To further prove the competition between phytoestrogen and DHT on AR binding, we examined the effects of phytoestrogens on DHT-activated AR nuclear translocation and immunofluorescence analysis which confirms that phytoestrogens, especially genistein, inhibit DHT-activated androgen receptor nuclear translocation. Results from ChIP show that phytoestrogens down-regulate DHT-induces AR binding to the androgen response elements(AREs, including AREI, AREII, and AREIII) in PSA promoter. Genistein remarkably down-regulates AR, binding to the AREI located in −250— −39 bp and AREIII in −4170— −3978 bp in the presence of DHT. In general, three phytoestrogens were identified to inhibit DHT-AR binding by competitively binding to AR and inhibit AR-mediated transactivation. And genistein shows the strongest effects among three phytoestrogens. Our findings confirm that phytoestrogens are AR antagonist in the regulation of AR-related PSA activation and cell proliferation, which provides valuable insights into the treatment of prostate cancer.

A novel basic ionic liquid, 1-(2-aminoethyl)pyridinium hydroxide, containing both Bronsted base and Lewis base sites has been used as an efficient catalyst for the synthesis of 2-amino-4-phenyl-6-(phenylsulfanyl)-3,5-dicyanopyridines. The condensation and oxidation tandem reaction of aldehydes, malononitrile, and thiols, performed in aqueous ethanol, afforded reasonable to good yields within 30–60 min. After the reaction, the catalyst could be recycled and reused. A possible mechanism to account for the tandem reaction is proposed. .

A large amount of organophosphate pesticides (OPs) is used throughout China. Animal studies have suggested that even moderate doses are toxic to neurodevelopment, but there are a few studies in humans. We investigated both the urinary levels of OP metabolites in children and their relationship with child neurodevelopment. Participating 301 young children (23-25 months of age) were recruited from two community hospitals in Shanghai between February and October 2008. We measured five nonspecific dialkyl phosphate (DAP) metabolite levels of OPs in the children's urine and examined their association with the children's developmental quotients (DQs) based on the Gesell Developmental Schedules (GDS). The creatinine-adjusted geometric means (GMs) of OP metabolites in urine samples were 11.27 μg/g for DMP; 6.99 μg/g for DMTP; 7.96 μg/g for DEP; 14.19 μg/g for DETP; and 4.55 μg/g for DEDTP. The children had relatively higher levels of OP urinary metabolites compared with those reported in developed countries, no association was found between child urinary levels of OP metabolites and any of the DQ scores. However, our results should be interpreted with caution, and more studies of children living in China are warranted given the relatively high levels of child OP urinary metabolites in Shanghai.

The flowing characteristics of coal slurry in floatation cyclone were investigated on the bases of theoretical calculation of velocity and pressure distributions by Navier-Stokes equation by means of reasonable simplification and modification. Thus, the position of multiphase interface of gas-liquid in the cyclone was located. Apart from this, it could be concluded that an air cylinder exists in the cyclone, the volume of which depends on the velocity, pressure of the fed material and the diameter of overflow pipe. The up-flow of jet stream with fine particles is limited by air cylinder, which is of great significance for the separation process in the flotation cyclone. Meanwhile, separation mechanism by floatation cyclone can be elucidated. Besides, it has been found that there are two types of fluid flow in floatation cyclone, inflow and outflow. In the cases of floatation cyclone with diameter of 100 mm, in the zone with the radius more than 31.5 mm, the radial velocity belong to outflow, and vice versa.

Strontium and oxygen co-doped La1.937Sr0.063CuO4+δ superconductor with Tc ≈ 40K, which is obtained by oxidizing strontium-doped starting ceramic sample La1.937Sr0.063CuO4 in NaClO solution, is annealed under different conditions to allow interstitial oxygen to redistribute. The evolution of the intrinsic superconducting property with the oxygen redistribution is studied in detail by magnetic measurements in various fields. It is found that there occurs the electronic phase separation from the single superconducting phase with Tc ≈ 40K into two coexisting superconducting states with values of Tc: 15 and 40K or of 15 and 35K in this system, depending on annealing condition. Our results indicate that the 15, 35 and 40 K superconducting phases associated with the excess oxygen redistribution are all thermodynamically meta-stable intrinsic states in this Sr/O co-doped cuprate.

The objective of this paper was to prepare paclitaxel-loaded microspheres, a kind of target-orientation anticancer drug. The paclitaxel-loaded microspheres were prepared with magnetic Fe3O4 nanoparticles and taxol. The morphology was characterized by scanning electron microscopy (SEM), and the average size and the size distribution were determined by a laser-size distributing instrument. High performance liquid chromatography (HPLC) was used to measure the paxlitaxel content. Experimental results indicated that the effective drug loading and the entrapment ratio of paclitaxel-loaded microspheres were 1.83% and 92.62%, respectively.

Chronic exposure to peroxisome proliferators (PPs) leads to increased incidence of liver tumors in rodents. Liver tumor induction is thought to require increased hepatocyte proliferation and suppression of apoptosis. Transcript profiling showed increased expression of proapoptotic genes and decreased expression of antiapoptotic genes in the livers of mice exposed to the PP WY-14,643 (WY). We tested the hypothesis that prior exposure to WY would increase susceptibility to apoptosis inducers such as Jo2, an antibody which activates the Fas (Apo-1/CD95) death pathway. When compared to their untreated counterparts, wild-type mice pretreated with WY exhibited increased caspase-3 activation and hepatocyte apoptosis following challenge with Jo2. Livers from WY-treated peroxisome proliferator-activated receptor alpha (PPARalpha)-null mice were resistant to the effects of Jo2. In the absence of Jo2 and detectable apoptosis, wild-type mice treated with WY exhibited increases in the activated form of caspase-9. As caspase-9 is a component of the apoptosome, we examined the expression of upstream effectors of apoptosome activity including members of the Bcl-2 family. The levels of the antiapoptotic Mcl-1 transcript and protein were significantly decreased by PPs. PPARalpha-null mice were also resistant to another treatment (concanavalin A) that induces hepatocyte apoptosis. These results (1) indicate that PPARalpha activation increases sensitivity of the liver to apoptosis and (2) identify a mechanism by which PPARalpha could serve as a pharmacological target in diseases where apoptosis is a contributing feature.

The clinical signs of a disorder known locally as "shakeback disease" in yaks in the North of the Qing Hai-Tibetan Plateau of China were defined: they included emaciation, unsteady gait, a 'shivering' back and deprived appetites. Coat colour was not affected. The mineral composition of soil and forages, and samples of blood and hair from yaks in affected ranches in this region were compared with those of 20 samples from unaffected areas. The mean concentration of molybdenum (Mo) in soil and forage was 4.85+/-0.21 and 4.96+/-0.25 microg/g (dry matter), respectively; the mean copper (Cu) to Mo ratio in the forage was only 1.34+/-0.36 compared to 8.12+/-1.31 for unaffected areas. The mean concentrations of Cu in blood and hair from the affected yaks were 0.29+/-0.17 and 3.51+/-1.12 microg/g, respectively, compared with 0.85+/-0.24 and 6.42+/-1.21 microg/g, for controls. The highest value for Cu in the blood of affected yaks was 0.58 mug/g and the lowest 0.03 microg/g (the corresponding highest values for unaffected yaks were 1.03 mug/g, the lowest 0.56 microg/g). There was a hypochromic microcytic anaemia and a low level of ceruloplasmin in the blood. The Cu deficiency in yaks was most severe during pregnancy and lactation, but oral administration of copper sulphate prevented and cured the disease. We conclude that "shakeback disease" of yaks in this region is probably caused by a secondary Cu deficiency, mainly due to the high Mo content in soils and forage.

Objective: To explore the role of cytokines on the pathogenesis of atherosclerosis, and the effect of Tongmai Jiangzhi oral liquid (TMJZ) on cytokines through observing serum P-selectins (Ps), von Willebrand (vWF), and D-dimer (D-D) in atherosclerosis (AS) patients.Methods: Sixty-three AS patients were randomly divided into the treated group (n = 33, treated with TMJZ, 10 ml each time, three times a day) and the control group (n = 30, treated with Lovastatin, 10 mg, once daily). The levels of serum lipids (enzymatic methods), Ps, vWF, and D-D were measured before and after 8 weeks of treatment.Results: Serum total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), apo-protein B-100 (apoB-100) were significantly decreased (P

Hypertension in end-stage renal disease (ESRD) may involve lack of endothelial nitric oxide (NO), as suggested by reduced total NO synthase (NOS) in dialysis patients. One reason might be due to substrate deficiency. To test the hypothesis that uremia is a state of intracellular l-arginine deficiency, uremic plasma was obtained from dialysis patients, and its effect was tested on arginine transport in cultured vascular endothelial cells. l-arginine transport ( P< 0.01) was reduced in human dermal microvascular endothelial cells (HDMEC) incubated for 6 h with 20% uremic plasma from peritoneal dialysis and hemodialysis patients obtained immediately predialysis. Similar transport inhibition was seen with ESRD plasma in human glomerular capillary and bovine aortic endothelial cells. Hemodialysis partially reversed inhibition of l-arginine transport. HDMECs incubated for 6 h with synthetic media containing high (uremic) urea concentrations showed inhibition ofl-arginine transport, but this was not competitive because acute exposure to urea had no impact on l-arginine transport. Over a 6-h period, urea-induced inhibition ofl-arginine transport was not sufficient to inhibit NOS activity, but after 7 days NOS activity was reduced. These cellular findings suggest that substrate delivery may be lowered, thus reducing endothelial NOS activity and contributing to hypertension in ESRD patients.

In vitro, 7 days of high blood urea nitrogen (BUN) inhibits endothelial l-arginine transport and nitric oxide synthase (NOS) activity. The present study investigates whether 7 days of high BUN in vivo influences renal hemodynamics, blood pressure (BP), and/or the nitric oxide (NO) system. Normal rats were fed low-nitrate food containing 30% urea for 7 days, which increased BUN (15 ± 1 to 69 ± 4 mg/100 ml, P < 0.001). High BUN did not reduce 24-hour urinary nitrite/nitrate excretion (a measure of total NO production). Baseline BP and renal hemodynamics were unaffected by high BUN as were the pressor and renal vasoconstrictor responses to acute NOS inhibition with NG-nitro-l-arginine-methyl ester. In addition, high BUN had no impact on renal corticall-arginine concentration, density of either endothelial NOS or neuronal NOS protein, or renal cortical NOS activity. NOS activity in the brain cerebellum was also unaffected. In conclusion, high BUN did not lead to vasoconstriction or NO deficiency in rats with normal renal function. Further studies are needed to evaluate the effect of high BUN on the NO system in rats with progressive renal functional insufficiency.

Circulating endothelial nitric oxide synthase inhibitory factor in some patients with chronic renal disease. Background Chronic renal disease (CRD) is associated with hypertension and reduced synthesis of nitric oxide (NO). Here, we investigated whether there is a circulating endothelial NO synthase (eNOS) inhibitory factor(s) in some patients with CRD that might directly influence endothelial NOS. Methods Human dermal microvascular endothelial cells (HDMECs) were incubated for six hours with 20% plasma from subjects with normal renal function (P Cr = 0.8 ± 0.2 mg%), and patients with moderate renal insufficiency of various causes (P Cr = 4.0 ± 1.5 mg%) and impact on NOS activity, transport of L-arginine, and abundance of eNOS protein were measured. Plasma concentrations of asymmetric and symmetric dimethyl L-arginine (ADMA and SDMA) were also measured. Results There was no effect of any human plasma on L-arginine transport. The NOS activity was variable in CRD patients and fell into two subgroups: CRD I, individual values similar to control, and CRD II, individual values lower than control mean. The effect of CRD plasma on NOS activity in cultured cells was not related to the primary disease, but was predicted by plasma ADMA levels since plasma ADMA was elevated in CRD II versus both control and CRD I. Blood urea nitrogen and creatinine levels were uniformly elevated in CRD plasma. The abundance of eNOS protein was unaffected by plasma. Conclusion High plasma levels of ADMA in CRD patients are independent of reduced renal clearance, suggesting an alteration in ADMA synthesis and/or degradation. High ADMA is a marker and is partly responsible for the inhibition of eNOS activity in cultured cells and may also result in reduced eNOS activity in vivo, with consequent hypertension.

Reduced nitric oxide synthesis by glomerular endothelial cells and increased proliferation of glomerular mesangial cells is associated with glomerular remodeling that leads to accelerated glomerulosclerosis. Estradiol induces nitric oxide synthesis and slows the progression of renal disease. Because the estradiol metabolites 2-hydroxyestradiol and 2-methoxyestradiol are more potent than estradiol in inhibiting growth of vascular smooth muscle cells, which are phenotypically similar to mesangial cells, we compared the effects of estradiol, 2-hydroxyestradiol, and 2-methoxyestradiol on growth of glomerular mesangial cells and on basal nitric oxide synthesis by glomerular endothelial cells. In human glomerular mesangial cells, estradiol and its metabolites concentration-dependently (1 nmol/L to 10 μmol/L) inhibited serum (2.5%)-induced DNA synthesis, cell proliferation, and collagen synthesis with the order of potency being 2-methoxyestradiol > 2-hydroxyestradiol > estradiol. ICI182780 (100 μmol/L, an estrogen receptor antagonist) blocked the growth inhibitory effects of estradiol but not 2-hydroxyestradiol or 2-methoxyestradiol. Treatment with estradiol, but not 2-hydroxyestradiol and 2-methoxyestradiol, induced nitric oxide synthesis ( P 3 H- l -citrulline from 3 H- l -arginine) in human glomerular endothelial cells, and these effects were blocked by ICI182780 and L-NMA (a nitric oxide synthesis inhibitor). In conclusion, estradiol may attenuate glomerulosclerosis by inducing nitric oxide synthesis via an estrogen receptor–dependent mechanism and by conversion to 2-hydroxyestradiol and 2-methoxyestradiol, which inhibit glomerular mesangial cell proliferation independent of estrogen receptors.

Our recent observations of reduced total nitric oxide synthesis in renal failure patients on peritoneal dialysis and haemodialysis suggest that hypertension in end-stage renal disease involves lack of vasodilatory endothelial NO. To directly test this, uraemic plasma was obtained from dialysis patients and incubated with cultured vascular endothelial cells, to determine the effect on nitric oxide synthase (NOS) activity in comparison with plasma from subjects with normal renal function. After incubation for 6 h with 20% uraemic plasma from peritoneal dialysis and immediately prehaemodialysis patients, NOS activity was reduced in human dermal microvascular endothelial cells. Haemodialysis did not remove the NOS-inhibitory activity of uraemic plasma nor did it activate inducible NOS, as NOS activity was always similar in control and dexamethasone pretreated cells. Nitric oxide production (accumulation of nitrite and nitrate) was lower in cells incubated with uraemic vs. normal plasma and excess arginine increased nitric oxide production by cells previously exposed to uraemic medium. This inhibitory effect was not associated with co-factor deficiency but did correlate with plasma concentrations of endogenous NOS inhibitors. These in vitro findings suggest that low endothelial NOS activity may contribute to hypertension in end stage renal disease patients.

In this paper, we design a symmetric Mach-Zehnder interferometer (MZI) gas sensor based on two-dimensional Photonic crystals (Phc), which is filled with the gases of different refractive index in the holes of the silicon plate. Self-Collimation (SC) effect analyzed by equi-frequency contour (EFC) is used to route the propagation of light straightly; the bending and splitting of lights are realized by the line-defect structures. Finite Difference Time Domain (FDTD) simulations show that the outputs of the MZI vary with the gas in the test arm and a pi phase shift of the two output light beams is achieved as the gas refractive index n=1.24. By analyzing the corresponding relationship between the output results and the refractive index of gases in the test arm, it can act as a gas sensor. Finally, we conclude the mechanisms of the outputs and analyze the phase shift and the Effective Index (neff) in the SC direction which is calculated by the radio of vector-k As the wavelength lambda=632.8 nm (the wavelength of CO2 laser), the size of the MZI is as small as 6745 nm times 6745 nm. Thus, we realize the micromation of the sensor, which may play an important role in high-density integration design.

A brief outline of our previous investigations into the mechanism of intrinsic bulk laser induced damage and our main conclusions serve as the introduction to exciting new results obtained by Shen et al. [Phys. Rev. Lett. (June 5. 1989)]: who measured the free electron absorption of 1064 nm photons photoacoustically in NaCl and SiO2. The electrons were generated with a 266 nm pump pulse by two- or three-photon transitions from the valence band. For a given pump energy which is chosen sufficiently low to avoid heating of the interaction volume by itself, the dependence of the photoacoustic signal and temperature rise were observed as a function of the energy of the 1064 nm pulse and found to be in agreement with the theory of free carrier heating by Epifanov et al. Temperatures approaching the melting point were produced in the materials under prebreakdown conditions. This work provides direct experimental proof that free electron absorption is the primary mechanism for heating wide-gap optical materials by intense laser pulses in the visible and near infrared, confirming the indirect measurements reported earlier by us. No evidence of electron impact ionization and ensuing avalanche formation is found up to the intrinsic damage threshold, throwing doubt onto the commonly held belief that it is responsible for free electron generation and eventual breakdown at 1064 nm.

Organic nonlinear optical materials have attracted considerable attention in recent years because of their potential applications in photonic devices and optical information processing. Recent studies have shown that annulene derivatives exhibit good second-order nonlinear optical properties, but their third-order nonlinear optical properties are studied little. In this paper, the values of molecular static linear polarizability α and second hyperpolarizability γ of substituted annulenes have been investigated with different levels of HF, B3LYP, BHandHLYP and CAM-B3LYP at different basis sets, respectively. Their ultraviolet spectra have also been calculated by using the TD-B3LYP method. It is found that the quality of the basis set is important for the hyperpolarizability calculations, and diffuse functions are important to obtain accurate results for the second hyperpolarizability. We also study the structure-optical property relationship for annulene. It is found that annulene molecular structure has a significant influence on third-order nonlinear optical response. Increasing the conjugation length and introducing push-pull electronic groups can enhance the second hyperpolarizability. But the introduction of push-pull electronic groups can enhance the hyperpolarizability more remarkably than increasing the conjugation length dose, which may be due to the fact that the introduction of push-pull electronic groups can provide a large number of polarizable electrons whereas increasing the conjugation length can only enhance the electron delocalization. Meanwhile the push-pull electronic group substituted annulenes can also exhibit high transparency in visible region. Thus, this work has a good reference for designing nonlinear optical material with high, nonlinear optical coefficient and good transparency. In addition, for the same push-pull electronic groups, the higher conjugation degree and the longer πup -conjugated bridge result in the decrease of HOMO-LUMO energy gap and transition energy which benefits the enhancement of nonlinear optical response. Our results demonstrate that annulene derivative shows both high transparency and large second hyperpolarizability, and thus becomes a promising candidate for third-order nonlinear optical material. In addition, the dynamic (hyper) polarizabilities of considered annulene molecules are calculated by using CAM-B3LYP method. It is found that in near-infrared region, with the increase of frequency of incident light, α (ω; ω), γ (-ω; ω, 0, 0) and γ (-2ω; ω, ω, 0) are all increased, and the near-resonance enhancement effect occurs. Under the condition of far resonance, α (ω; ω), γ (-ω; ω, 0, 0) and γ (-2ω; ω, ω, 0) change little. This dispersion effect may be helpful for the experimental study and applications as well.

Objective To investigate the hepatoprotective activity of different parts of Hypericum japonicum against carbon tetrachloride(CCl 4 )-induced hepatitis and α-naphthyl-isothiocyanate (ANIT)-induced cholestasis. Materials and Methods Mice were divided into groups and then administrated orally with solutions extracted from herbs before they were modeled in the experiments. Levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and total bilirubin (T-BIL) in serum were evaluated. HPLC fingerprint was used for phytochemical analysis of the extracts. Results The total aqueous extract of Hypericum japonicum had an obvious effect on the decreasing of AST, ALT and T-BIL levels in serum. The isolated fraction IV (F4) exhibited a preferable activity of ameliorating cholestasis, while Fraction V (F5) was more efficacious in protecting liver from injury. Chemical fingerprint indicated that F5 contained several flavonoids which might be the active chemicals against hepatotoxicity. Conclusion Different fractions of Hypericum japonicum manifest different effect, indicating their different potentials as candidacies of new drugs.

Using an isolated salt-perfused rat lung model, the authors investigated whether N-methyl-D-aspartate (NMDA) (1 mM) in the pulmonary circulation effects the pulmonary vascular responses to an acute stimulus of hypoxic insult under baseline, nitric oxide synthetase (NOS)-blocked conditions (N-omega-nitro-L arginine methyl ester; L-NAME, 2 mM), and with an NMDA receptor blocker, MK-801 (0.3 microM) added. NOS activity at baseline, and in response to hypoxia, NMDA, L-NAME, and a combination of these stimuli were also assessed. NMDA did not in itself alter hypoxic pulmonary vasoconstriction (HPV), but did significantly attenuate HPV during VOS blockade. This effect of NMDA was erased by MK-801. Assessment of NOS activity showed that hypoxia alone caused a doubling of NO production within the lung. This effect was erased by the addition of L-NAME. NMDA alone caused a significant, 3-fold increase in NOS activity, which was not further affected by hypoxic chalenge. L-NAME did not depress NOS activity in the hypoxia + NMDA group. These data suggest that NMDA receptor activation results in increased NOS activity and presumably increased production of NO. The increased NOS activity induced by NMDA receptor stimulation is resistant to the blockade effect of L-NAME. The actions of NMDA receptor activation may represent a natural protective mechanism, at least within the pulmonary vasculature, in face of acute, abnormal stimuli such as hypoxia.

We report the superconductivity in iron-based oxyarsenide Sm[O1-xFx]FeAs, with the onset resistivity transition temperature at 55.0K and Meissner transition at 54.6 K. This compound has the same crystal structure as LaOFeAs with shrunk crystal lattices, and becomes the superconductor with the highest critical temperature among all materials besides copper oxides up to now.

The elastic constants, electronic structure and optical properties of solid krypton are investigated by first-principles plane-wave pseudo-potential method in the scheme of density functional theory within local density approximation and generalized gradient approximation. The calculated elastic constants under pressure are in good agreement with the experimental and theoretical data. The obtained Debye temperature and sound velocity increase with pressure. The electronic structure and optical properties under pressure are also predicted, the energy band gap decreases, optical absorption coefficient increases and absorption peak widens under pressure. This leads to easy electron transition and solid krypton probably becomes semiconductor.

The temporal and spatial distributions of the plasma temperature during the dissipation process of lightning are calculated theoretically by applying the equation of motion，the equation of continuity and the equation of energy conservation of hydrostatics. The result shows that the temperature decay at a given radius is quicker in the earlier stage and slower in the later stage; Furthermore，the higher the original temperature，the quicker the decay. The temperature decays slower when the radius becomes larger. At the same time，the larger the radius of lightning channel，the greater the temperature gradient, and vice versa. According to the time and position of freezing temperature of NO，we can conclude primarily that NOx are produced in the channel of less than 9 mm radius in the time within 50 ms after the lightning return stroke.

According to the relative intensities of lines and transition parameters, through linear fit of linear function, two fit parameter are obtained. And by adopting these parameters, transition probabilities of spectral lines for special configuration or highly excited states can be calculated. In the present work, on the basis of spectroscopic analysis for N+ spectra, the transition probability whose upper states are pair coupling is obtained. The present work gives a simple and feasible new semi-classical method to calculate transition probabilities, especially for special configurations or highly excited states.

The calculations of the first hyperpolarizability frequency dispersion effect of hemicyanine derivative chromophore have been performed employing time-dependent Hartree-Fock and sum-over-states method respectively. Two-photon resonance enhancement characteristics of second harmonic generation β(-2ω；ω，ω) have also been investigated using the two-level model (TLM), which was originated by Ouder and Chemla. The results indicate that the first excited state dominates the nonlinear optical properties of hemicyanine derivatives. The first hyperpolarizability β(-2ω；ω，ω) increases with the decrease of fundamental wavelength and gives rise to two-photon resonance near the fundamental wavelength of 950 nm, in accordance with the known experimental facts. In addition, the relaxation effect of the excited states should be considered for TLM in the resonance regime. These researches provide theoretical references for experimental measurements.

Based on the classical electrostatics theory, the model of dipole-dipole interaction in the aggregation of rod-like amphiphilic molecules in Langmuir-Blodgett(LB)films has been presented in the paper. The relations between LB films structure and spectral absorption peak were obtained by using this model. For Z-type films, the dependence of molecular aggregation state on the structure parameters, i.e. separation distance a, separation between two adjacent layers d, molecular orientation θ, and layer number g, were studied by applying our model. The theoretical results agree well with experimental data.

Excitatory Amino Acids (NMDA) Alter Nitric Oxide Synthetase (NOS) Activity in the Isolated Salt Perfused Rat Lung

With bicarboxylic acids as crosslinking agents and H 2 SO 4 as catalyst, polyvinyl alcohol (PVA) was crosslinked in the temperature range of 90–120°C, resulting in thin-film composite membranes with polysulphone as substrate. IR analysis showed that crosslinking changes the chemical structure of PVA, involving H 2 SO 4 in the reaction. Besides oxalic acid, other bicarboxylic acids, such as malonic acid, succinic acid and citric acid can also crosslink PVA in the temperature range given above. RO tests showed that the salt rejection of membranes using oxalic acid as crosslinking agent was higher than that of membranes using other bicarboxylic acids.

By the comparison of the reaction products of gem-dihalocyclopropanes under various conditions, it is suggested that similar to the reactions with metals, the reactive radical intermediates which make the reaction results complicated are formed in the reactions of gem-dihalocyclopropanes with alkyl lithium. Studies on the competitions between ring opening and intramolecular C—H insertions of cyclopropylidenes generated by the reactions of gem-dihalocyclopropanes with metals and discussions on the reaction mechanism are also given in this paper.