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Priming effect (PE) plays an important role in regulating terrestrial soil carbon (C) cycling, but the impact of different C addition modes on the PE in subtropical forest ecosystems with increasing nitrogen (N) deposition is unclear. In this study, we investigated the effects of C addition patterns (single or repeated C addition) on soil PE by adding激发效应(PE)在调控陆地土壤碳(C)循环中发挥着重要作用,但在氮(N)沉降日益严重的亚热带森林生态系统中,不同C添加模式对PE的影响尚不清楚。本研究通过添加

A novel concept that conversion of chiral 2-substituted DMAP into its DMAP-N-oxide could significantly enhance the catalytic activity and still be used as an acyl transfer catalyst is presented. A new type of chiral 2-substituted DMAP-N-oxides, derived from l-prolinamides, has been rationally designed, facilely synthesized, and applied in the dynamic kinetic resolution of azlactones. Using simple MeOH as the nucleophile, various l-amino acid derivatives were produced in high yields (up to 98% yield) and enantioselectivities (up to 96% ee). Furthermore, α-deuterium labeled l-phenylalanine derivative was also obtained. Experiments and DFT calculations revealed that in 2-substituted DMAP-N-oxide, the oxygen atom acted as the nucleophilic site and the N-H bond functioned as the H-bond donor. High enantioselectivity of the reaction was governed by steric factors, and the addition of benzoic acid reduced the activation energy by participating in the construction of a H-bond bridge. The theoretical chemical study indicated that only when attack directions of the chiral catalyst were fully considered could the correct calculation results be obtained. This work paves the way for the utilization of the C2 position of the pyridine ring and the development of chiral 2-substituted DMAP-N-oxides as efficient acyl transfer catalysts.

A Cs2CO3-mediated [2 + 1] cycloaddition of benzofuran-derived azadienes (BDAs) with bromomalonate by using a dearomatization strategy has been developed. Through this process, BDAs serve as a potential 2-atom synthon in the construction of a range of functionalized spirocyclopropane derivatives, such as spirobenzofuran-2-cyclopropanes and spiroindane-2-cyclopropanes.

Excitatory toxicity(ET) is an important factor of neuropathic pain(NPP) induced by central sensitization(CS), and the association of pannexin-1(Panx1)-Src-N-methyl-D-aspartate receptor subunit 2 B(NMDAR-2 B) is an important new pathway for ET to initiate CS. The present study confirmed whether the central analgesic effect of Chuanxiong Rhizoma extract(CRE) was achieved through the synchronous regulation of the brain and spinal pathways of Panx1-Src-NMDAR-2 B. In this study, dynamic and simulta-neo-us microdialysis of the brain and spinal cord in vivo combined with behavioristics, high performance liquid chromatography(HPLC)-fluorescence detection, microdialysis analysis(ISCUS~(flex)), ultrasensitive multifactorial electrochemiluminescence immunoassay, ELISA, and Western blot was employed to investigate the protein expression of NMDAR-2 B, Src, and Panx1, extracellular excitatory amino acids, cytokines, energy metabolites, and substance P in spinal dorsal horn(SDH) and anterior cingulate cortex(ACC) after CRE intervention with the rat model of spared sciatic nerve injury(SNI) as the experimental tool. Compared with the sham group, the SNI group exhibited diminished mechanical withdrawal threshold(MWT)(Plt;0.01), increased cold spray scores(Plt;0.01), glutamate(Glu), D-serine(D-Ser), and glycine(Gly) in extracellular fluids of ACC, and Glu, D-Ser, interleukin-1β(IL-1β), and lactic acid(Lac) in extracellular fluids of SDH(Plt;0.05), dwindled tumor necrosis factor(TNF-α)(Plt;0.05), and elevated protein levels of NMDAR-2 B, Src, and Panx1 in ACC(Plt;0.05). Compared with the SNI model rats, high-and medium-dose CRE(CRE-H/M) could potentiate the analgesic activity as revealed by the MWT test(Plt;0.05) and CRE-M enabled the decrease in cold spray scores(Plt;0.05). CRE-H/M could inhibit the levels of Glu, D-Ser and Gly in the extracellular fluids of ACC(Plt;0.05), and the levels of Glu in the extracellular fluids of SDH(Plt;0.05) in SNI rats. CRE-M significantly increased the levels of glucose(Gluc), Lac, interferon-gamma(IFN-γ), keratinocyte chemoattractant/human growth-regulated oncogenes(KC/GRO), and IL-4 in extracellular fluids of SDH in SNI rats(Plt;0.05). CRE-H/M/L could also inhibit the levels of NMDAR-2 B, Src and Panx1 in ACC and SDH in SNI rats(Plt;0.05). The central analgesic effect of CRE is presumedly related to the inhibited release of excitatory amino acid transmitters(Glu, D-Ser and Gly) in ACC and SDH of SNI rats, decreased protein expression of NMDAR-2 B, Src and Panx1 in the two regions, and the regulation of the Panx1-Src-NMDAR-2 B pathway in the spinal cord and brain. The above findings partially clarified the scientific basis of clinical analgesic effect of Chuanxiong Rhizoma.

Light is a important way in controlling vegetable pests. In this work, we examined the effects of blue light on利用灯光控制害虫是蔬菜害虫绿色防控的重要手段。本研究探讨了蓝光对黄瓜烟粉虱种群及黄瓜营养物质、次生代谢物、抗性相关酶的影响。结果表明: 在直接驱避试验条件下,蓝光对烟粉虱成虫有较强的驱避作用,光照强度越大、照射时间越长,对烟粉虱的驱避作用越强。在相同光强和光照时间下,直射光较透射光的驱避作用强。其中,1200 lx的蓝光直射烟粉虱5 min后,烟粉虱的虫口减退率为77.7%,比透射光高17.4%;1750 lx的蓝光直射2 min后,虫口减退率41.2%,比透射光高10.6%。盆栽条件下,蓝光照射对黄瓜叶片上的烟粉虱也有较好的驱避作用,100 lx蓝光照射5 h后,烟粉虱种群的校正虫口减退率达到88.5%。蓝光对烟粉虱的生长发育有一定的影响,随着蓝光照射时间的延长,烟粉虱发育历期延长。此外,蓝光照射显著提高了黄瓜叶片中可溶性糖、游离蛋白、总酚和类黄酮含量,降低了脯氨酸含量,与烟粉虱抗性相关的挥发物反式-β-法尼烯、反式-2-己烯醛、顺式-4-庚烯醛、反式β-罗勒烯、D-香芹酮、长叶烯和3-蒈烯含量,以及过氧化物酶、过氧化氢酶、超氧化物歧化酶和抗坏血酸过氧化物酶活性均显著提高。说明蓝光照射能直接驱离烟粉虱,并通过改变烟粉虱寄主蔬菜的代谢途径来提高寄主蔬菜对烟粉虱的抗性。其中100 lx的蓝光照射对田间烟粉虱有较好的控制作用。.

Background Congenital heart defects (CHDs) are the most common birth defects worldwide. Maternal obesity has been proposed as a risk factor for CHDs, but the results are controversial and inconclusive. Pregestational diabetes (PGDM) is well known as a risk factor for CHDs and is closely related to obesity. However, the effect of PGDM on the association between maternal obesity and CHDs has not been investigated.Objectives We aimed to explore the association between maternal obesity and CHDs and to further evaluate the mediation effect of PGDM on this association.Methods We involved 53708 mother-infant pairs with deliveries between 2017 and 2019 from the Birth Cohort in Shenzhen (BiCoS). Mothers were categorized into four groups: the underweight group (BMI < 18.5), normal weight group (18.5 ≤ BMI < 24), overweight group (24 ≤ BMI < 28) and obesity group (BMI ≥ 28). To evaluate the association between BMI and CHDs, we fit multivariable logistic regression models, adjusting for maternal age, maternal education level, mode of conception, parity, GDM and offspring sex. Mediation analysis was used to confirm the mediation effect of PGDM on the association between maternal obesity and CHDs.Results The proportion of obese individuals in the BiCoS was 2.11%. Overall, 372 (0.69%) infants were diagnosed with CHDs. The prevalence of CHDs in underweight, normal weight, overweight and obese individuals was 0.64%, 0.68%, 0.72% and 1.24%, respectively. Maternal obesity was associated with an increased risk of CHDs (OR=1.97, 95% CI 1.14–3.41). The offspring of women with PGDM were 6.88 times (95% CI 4.11–11.53) more likely to have CHDs than the offspring of mothers without PGDM. The mediation effect of PGDM on the association between maternal obesity and CHDs was significant (OR=1.18, 95% CI 1.06–1.32). The estimated mediation proportion was 24.83%.Conclusion Our findings suggested that maternal obesity was associated with CHDs and that PGDM partially mediated the association between maternal obesity and CHDs.

A novel concept that conversion of chiral 2-substituted DMAP into its DMAP

A DMAP-N-oxide, featuring an α-amino acid as the chiral source, was developed, synthesized and applied in asymmetric Steglich rearrangement. A series of O-acylated azlactones afforded C-acylated azlactones possessing a quaternary stereocenter in high yields (up to 97 % yield) and excellent enantioselectivities (up to 97 % ee). Compared to the widespread use of pyridine nitrogen, which serves as the nucleophilic site in the asymmetric acyl transfer reaction, we discovered that chiral DMAP-N-oxides, in which the oxygen now acts as the nucleophilic site, are efficient acyl transfer catalysts. Our finding might open a new door for the development of chiral DMAP-N-oxides for asymmetric acyl transfer reactions.

The proinflammatory cytokine IL-1β plays critical roles in inflammatory and autoimmune diseases. IL-1β signaling is tightly regulated to avoid excessive inflammatory response. In this study, we identified the E3 ubiquitin ligase membrane-associated RING-CH-type finger 3 (MARCH3) as a critical negative regulator of IL-1β–triggered signaling. Overexpression of MARCH3 inhibited IL-1β–triggered activation of NF-κB as well as expression of inflammatory genes, whereas MARCH3 deficiency had the opposite effects. MARCH3-deficient mice produced higher levels of serum inflammatory cytokines and were more sensitive to inflammatory death upon IL-1β injection or Listeria monocytogenes infection. Mechanistically, MARCH3 was associated with IL-1 receptor I (IL-1RI) and mediated its K48-linked polyubiquitination at K409 and lysosomal-dependent degradation. Furthermore, IL-1β stimulation triggered dephosphorylation of MARCH3 by CDC25A and activation of its E3 ligase activity. Our findings suggest that MARCH3-mediated IL-1RI degradation is an important mechanism for attenuating IL-1β–triggered inflammatory response.

In this study, a water stable metal-organic framework FIR-53 is applied as a single-crystal container for anion exchange. The exceptional chemical stability and low crystallographic symmetry of FIR-53 makes it possible to determine anionic guests. Through ion exchange and single-crystal to single-crystal (SC-SC) transformation, 8-hydroxypyrene-1,3,6-trisulfonate (SG7, solvent green 7, ion form as SG73-) is introduced into the pores of FIR-53 to obtain SG7@FIR-53. Because of the spatial confinement and partition effect, SG7@FIR-53 shows the bright exciter emission of SG7 ions. Interestingly, the composite SG7@FIR-53 exhibits a sensitive fluorescence quenching response against Cr2O72- and MnO4- in aqueous solution. Especially, the detection limit toward MnO4- is as low as 0.12 ppb, which is the smallest value to date. Moreover, the prepared SG7@FIR-53 film also displays a broad response to nitro explosives in vapor/aqueous phase. Compared with the results of FIR-53, the range and sensitivity were greatly improved.

An efficient route to construct 2,5-disubstituted tetrazole hemiaminal silyl ethers via one-pot three-component hemiaminal silylation of 5-substituted tetrazoles, aldehydes, and silyl triflates was developed. Diverse 2,5-disubstituted tetrazole hemiaminal silyl ethers were obtained with 37 : 63–>99 : 1 regioisomeric ratios. The regioselectivities of this reaction were significantly affected by steric hindrance and the conjugation effects of substitutions on the 5-position of tetrazoles.

From the perspective of the chromophore, 1,1,2,2-tetrakis(4-(pyridin-4-yl)phenyl)ethane (TPPE) with the π-electron-rich tetraphenylethylene (TPE) and aggregation induced emission feature is selected as functional ligand to construct the fluorescent metal–organic frameworks. Three luminescent MOFs (1–3) have been successfully synthesized. Through combining 4,4′,4″-nitrilotrisbenzoic acid (H3TNB) with electron-donor triphenylamine (TPA), the highly porous pillared-layer compound 1 [Zn3(TPPE)1/2(TNB)2](4DMA·7H2O) was synthesized; interestingly, this MOF sensor film realizes the fast detection for nitrobenzene compounds with a response time of less than 3 min as well as good recyclability. Compound 2 [Zn7(TPPE)2(SO42–)7](DMF·H2O) exhibits the clear “turn-off” quenching responses for Cr2O72– in aqueous phase with high selectivity and sensitivity. Meanwhile, the fluorescent properties of compound 3 [Zn2(TPPE)3/2(NO3–)(OH–)(H2O)](DMF·2H2O) were also investigated. Thus, these MOF materials could serve as the prom...

The theoretical tensile strength of Ni-based model superalloys was investigated by density functional theory calculations. The superalloy was modeled as a γ-Ni/γ′-Ni3Al multilayer, and the strengthening effect induced by alloying elements X (X = Re, Ru, Cr, Mo, W, or Ta) close to the γ/γ′ interface was investigated. Theoretical calculations show that the tensile strength of the model superalloy is ∼1 GPa higher than that of the γ′-Ni3Al phase, although the critical strain is ∼38% lower than that of the pure γ′-Ni3Al phase. Except for Ta, doping at the Al site of the γ-Ni/γ′-Ni3Al interface significantly increases the theoretical tensile strength (>7%) or critical strain (>10%) of the γ-Ni/γ′-Ni3Al multilayer. Local atomic disorder is observed in the Ni–Al sublayer of the γ′-Ni3Al block of the superalloy, wherein the Ni–Al atomic layer decomposes into an Al layer and a Ni layer when the strain exceeds a critical value. The charge density difference and partial density of states provide further insight into the changes of chemical bonds and charge redistribution during the tensile process. Charge transfer from Al to Ni in the γ′-Ni3Al precipitate of the superalloy could account for its higher tensile strength than the single γ′ phase. Moreover, covalent-like Ni–X bonds inhibit deformation of the system, resulting in tensile strengthening of doped γ-Ni/γ′-Ni3Al multilayers.

In this work, bovine serum albumin (BSA) and eosine B (EB) were selected as a model protein and sonosensitizer, respectively. The sonodynamic damage to protein in the presence of EB and its mechanism were studied by means of absorption and fluorescence spectra. The results indicated that the synergistic effects of ultrasound and EB can efficiently damage the BSA molecules, and the damage of protein could be mainly due to the generation of reactive oxygen species (ROS). The damage degree of protein increased with the increase of ultrasonic time and EB concentration because of the increased quantities of ROS. Hydroxyl free radical (OH) was the major mediators of the ultrasound-inducing proteins damage in the presence of EB. In addition, the quantities of ROS from the diphenylcarbazide (DPCI)-EB solutions and the DPCI-fluorescein (FS) solutions with or without ROS scavengers were contrasted, respectively. The results show that FS mainly produce OH, but the quantities of ROS in the presence of FS were lower than those of EB, which indicates that the nitro and bromine substituent groups on the benzene ring of FS increase the quantity of ROS, but do not change the kinds of ROS.

Seed development is an important process of reproductive development and consists of embryo and endosperm development; both comprise several key processes. To determine and investigate the functions of the dynamic DNA methylome during seed development, we profiled the DNA methylation genome wide in a series of developmental stages of rice (Oryza sativa) embryo and endosperm by methylcytosine immunoprecipitation followed by Illumina sequencing. The results showed that embryo is hypermethylated predominantly around non-transposable element (TE) genes, short DNA-TEs, and short interspersed TEs compared with endosperm, and non-TE genes have the most diverse methylation status across seed development. In addition, lowly expressed genes are significantly enriched in hypermethylated genes, but not vice versa, confirming the crucial role of DNA methylation in suppressing gene transcription. Further analysis revealed the significantly decreased methylation at early developing stages (from 2 to 3 d after pollination), indicating a predominant role of demethylation during early endosperm development and that genes with a consistent negative correlation between DNA methylation change and expression change may be potentially directly regulated by DNA methylation. Interestingly, comparative analysis of the DNA methylation profiles revealed that both rice indica and japonica subspecies showed robust fluctuant profiles of DNA methylation levels in embryo and endosperm across seed development, with the highest methylation level at 6 d after pollination (2 d after pollination of endosperm in japonica as well), indicating that a complex and finely controlled methylation pattern is closely associated with seed development regulation. The systemic characterization of the dynamic DNA methylome in developing rice seeds will help us understand the effects and mechanism of epigenetic regulation in seed development.

Ultrasonic technique was employed to extract polysaccharides from pomegranate peel. The optimal conditions for ultrasonic extraction of pomegranate peel polysaccharide (PPP) were determined by response surface methodology. Box-Behnken design was applied to evaluate the effects of four independent variables (ratio of water to raw material, extraction time, extraction temperature, ultrasonic power) on the yield of PPP. The correlation analysis of mathematical-regression models indicated that quadratic polynomial model could be employed to optimize the ultrasonic extraction of PPP. The optimum extraction parameters were as follows: ratio of water to raw material, 24 ml/g; extraction time, 63 min; extraction temperature, 55°C; and ultrasonic power, 148 W. Under these conditions, the polysaccharide yield was 13.658 ± 0.133% for the pomegranate peel, which well matches with the predicted value.

By means of creep properties measurement and microstructure observation, an investigation was carried out to study the creep behaviors of the as-cast TiAl-Nb alloy at temperature near 910 oC. Results showed that the microstructure of as-cast TiAl-Nb alloy consisted of γ/α2 phases with the lamellar feature, and the boundaries with irregular serrated configuration consisted of single γ phase, and located in between the lamellar γ/α2 phases with different orientations. The as-cast TiAl-Nb alloy displayed a better creep resistance at high temperature and longer creep life. Compared to α2 -Ti3Al phase, the γ phase possessed a weaker strength, therefore, the crack was easily initiated along the boundaries at about 45° angles relative to the stress axis, and propagated along the boundaries parallel to the orientation of lamellar γ/α2 phases up to the occurrence of creep fracture. Thereinto, the tearing edges formed on the surface of the fracture being inclined with the lamellar γ/α2 phases are attributed to the α2-Ti3Al phase with better strength hindering the crack propagation during creep.

In this work, the binding characteristics of methylene blue (MB) to human serum albumin (HSA) and the influence of Cu(2+) and Fe(3+) on the binding affinity of MB to HSA were investigated using fluorescence, absorption, circular dichroism (CD) spectroscopy and molecular modelling. The results of competitive binding experiments using the site probes ketoprofen and ibuprofen as specific markers suggested that MB was located in site I within sub-domain IIA of HSA. The molecular modelling results agreed with the results of competitive site marker experiments and the results of CD spectra indicated that the interaction between MB and HSA caused the conformational changes in HSA. The binding affinity of MB to HSA was enhanced but to a different extent in the presence of Cu(2+) and Fe(3+), respectively, which indicated that the influence of different metal ions varied. Enhancement of the binding affinity of MB to HSA in the presence of Cu(2+) is due to the formation of Cu(2+)-HSA complex leading to the conformational changes in HSA, whereas in the presence of Fe(3+), enhancement of the binding affinity is due to the greater stability of the Fe(3+)-HSA-MB complex compared with the MB-HSA complex.

An efficient route to construct chiral acyclic purine nucleosides containing a hemiaminal ester moiety is reported via three-component dynamic kinetic resolution of purines, aldehydes, and acid anhydrides. The procedure provides diverse chiral acyclic purine nucleoside analogues in a regioselective manner with good yields (up to 93% yield) and excellent enantioselectivities (up to 95% ee). Furthermore, the chiral (acyloxyalkyl)-5-fluorouracil could also be generated as a potential prodrug of 5-fluorouracil.

There is growing evidence that the lectin pathway is significantly associated with acute rejection. Rare studies associated both gene polymorphisms of MBL2 and FCN2 with acute rejection after kidney transplantation. The aim of the present study was to investigate the role of the lectin gene profile and clinical risk factors such as PRA level on acute rejection in kidney transplant recipients.We prospectively analyzed 157 kidney transplant recipients with and without acute rejection. A total of 6 well-known functional single-nucleotide polymorphisms in the MBL2 gene and 5 in the FCN2 gene of the recipients were determined by gene sequencing. MBL2 and FCN2 genotypic variants were analyzed for association with the incidence of acute rejection within the first year after kidney transplantation.After adjusting for variables of P0.2, we found the differences in the incidence of acute rejection were only according to panel-reactive antibodies (odds ratios (OR) = 6.468, 95% confidence intervals (CI)= 2.017-20.740, P = 0.002) and the HH genotypes of MBL2 promoter -550 (OR = 2.448, 95%CI = 1.026-5.839, P = 0.044).Panel-reactive antibodies and the HH genotypes of MBL2 promoter -550 have significant impacts on the risk of developing acute rejection after kidney transplantation.

[Cu(C9H6O5)(H2O)3], monoclinic, C2/c (no. 15), a = 21.678(13) Å, b = 9.071(6) Å, c = 13.786(9) Å, β = 122.738(7)°, V = 2280(2) Å3, Z = 8, R gt(F) = 0.0613, wR ref(F 2) = 0.1682, T = 296(2) K.

Determining the effects of the critical structure of forests on soil and water conservation aids in understanding forest functions and scientific decision-making in management practices. Quadratic polynomial regression models were established for five pure tree ( Pinus massoniana Lamb) plots between vegetation fractional coverage (VFC) and soil/water conservation effects (SCE/WCE) for 144 erosive rainfall events from 2007 to 2010 in Hetian Town, Changting County, Fujian Province, a typical water-eroded area in southern China. The SCE/WCE corresponds to the ratios of soil loss/runoff depth of each tree plot to those of the control plot under each rainfall event. The results show that increasing VFC exhibits descending (DS), descending–ascending (DA), ascending–descending (AD), and ascending (AS) trends in the VFC–SCE and VFC–WCE curves, which indicate positive or negative effects of plot trees on soil and water conservation. In general, the effects on soil conservation on the plots were more notable than those on water conservation, and most of the SCE and WCE values reflect the positive effect of trees on soil and water conservation. Most determination coefficients of both the VFC–SCE and VFC–WCE models exceeded 0.6, and varied with the year and the effect. The positive effects of the pure trees occurred mainly during rainfall events with relatively higher rainfall depth, stronger intensity, and shorter duration, whereas the negative effects occurred mainly during rainfall events with lower rainfall depth, weaker intensity, and longer duration. The transition effects DA and AD appeared largely during rainfall events with moderate rainfall depth, intensity, and duration. The critical VFCs for soil and water conservation during rainfall events were 0.4 and 0.5, respectively, which provided a reference for the evaluation and planning of forest reconstruction in this and similar water-eroded areas.

Assessing the inter-annual variation of regional grassland productivity is imperative to meet the local requirements of grassland adaptive management at regional- or landscape- scale. For the semiarid grassland of Inner Mongolia, the improved CASA model, a kind of light-energy-efficiency model, was used to simulate the Net Primary Productivity (NPP) of the regional grassland. And this study further calculated the Standard Deviation (SD) and Coefficient of Variation (CV) of the regional NPP. Both of SD and CV were used to reflect the fluctuations of regional NPP in the study area among years. Approximately 1/3 of the regional NPP over the years were dramatically changed, frequently up to large amplitude by an average rate of 1 times or more.

The effects of planting transgenic soybean on the yield, quality and other agronomic traits were determined. No marked differences on yield were found between the succeeding crops planted on field where transgenic soybean were planted in the previously year and those planted on field where non-transgenic control soybean were planted in the last year. In parallel with this similarity, dry mass accumulation of wheat and maize showed no differences for those crops growing on the two different fields. The height, spike length and the gluten content of wheat planted on the two different fields were also investigated and no difference was found. In addition, the sugar content of beet was not affected by planting them on field where transgenic soybean was previously planted.

Starting with the standard complex medium HL-5C, the influence of different medium components on the growth behavior of Dictyostelium discoideum was investigated. For this purpose, each component was individually deleted from the complex medium HL-5C, and the overall concentration of all components as well as the kinds and concentrations of carbon source were varied. The effects of the supplementation with major components of synthetic medium like vitamins, trace metals, inorganic salts were also investigated. When glucose being the carbon source was deleted from the standard HL-5C medium, the maximal cell density then had a drastic drop. Deletion of yeast extract also caused lower maximal cell density. Of all the carbohydrates investigated only maltose and glucose led to higher final cell concentration. Adding inorganic salts such as CaCl2 and MgCl2 to HL-5C medium significantly improved the cell growth, whereas addition of vitamins or trace metals had little effect on cell growth. A semi-empirical model is employed to simulate the cell growth.

Trypsin‐catalyzed, kinetically controlled synthesis of a precursor, dipeptide of thymopentin (TP‐5), Bz–Arg‐Lys–OH (or–OEt) in organic solvents was studied. Bz–Arg–OEt was used as the acyl donor and Lys–OH and Lys–OEt were used as the nucleophiles. Ethanol was selected as the organic solvent from ethanol, methanol, acetonitrile, and ethyl acetate tested under the experimental conditions. As expected, Lys–OEt is not a suitable nucleophile in trypsin‐catalyzed reaction, due to its competition with the protective Arg–OEt as acyl donor for the active site of trypsin, while Lys–OH does not have this problem. The optimal reaction condition for the synthesis of Bz–Arg‐Lys–OH was set up as 20% Tris‐HCl buffer, pH 8.0, 35°C for 6 h with the yield of 52.5%, or for 18–24 h with the yield of about 60%.

Chemo-enzymatic synthesis of the tripeptide Bz-RGD-OEt was conducted in this study. First of all, free dipeptide, Gly-Asp was synthesized by a novel chemical method only using glycine at a large scale with low cost, followed by esterification of Gly-Asp. The linkage of the third amino acid Bz-Arg-OEt to Gly-Asp-(OEt) 2 was completed by enzymatic method in organic solvents. The effects of organic solvents, pH value, reaction temperature and water content on the yield of Bz-RGD-OEt synthesis were examined. The optimum conditions for Bz-GRD-OEt synthesis are pH 8.0, 30 °C, in ethanol/Tris–HCl buffer system (70:30, v/v), 5 h with the maximum yield of 72.5%.

PPL-catalyzed synthesis of the precursor dipeptides of RGD as a cellular adhesion factor, Benzyl-Arg-Gly-NH2 and CBZ-Gly-Asp-NH2, was conducted in water-organic cosolvents systems. Five water-miscible organic solvents, which have some advantage over the water-immiscible organic solvent systems or the anhydrous organic solvent systems used often in protease-catalyzed synthesis of a peptide bond, were tested. The reaction condition of PPL-catalyzed synthesis of the dipeptides was optimized by examining the main factors affecting the product yield. The optimal reaction condition for the synthesis of Benzyl-Arg-Gly-NH2 was set up as pH 8.0, 15 degrees C in 40% MeOH for 10 h with the maximum yield of 73.6%. The optimum condition for the synthesis of CBZ-Gly-Asp-NH2 was pH 7.0, 15 degrees C in 50% MeOH for 10h with the maximum yield of 67.0%.

In this work, the binding characteristics of methylene blue (MB) to human serum albumin (HSA) and the influence of Cu(2+) and Fe(3+) on the binding affinity of MB to HSA were investigated using fluorescence, absorption, circular dichroism (CD) spectroscopy and molecular modelling. The results of competitive binding experiments using the site probes ketoprofen and ibuprofen as specific markers suggested that MB was located in site I within sub-domain IIA of HSA. The molecular modelling results agreed with the results of competitive site marker experiments and the results of CD spectra indicated that the interaction between MB and HSA caused the conformational changes in HSA. The binding affinity of MB to HSA was enhanced but to a different extent in the presence of Cu(2+) and Fe(3+), respectively, which indicated that the influence of different metal ions varied. Enhancement of the binding affinity of MB to HSA in the presence of Cu(2+) is due to the formation of Cu(2+)-HSA complex leading to the conformational changes in HSA, whereas in the presence of Fe(3+), enhancement of the binding affinity is due to the greater stability of the Fe(3+)-HSA-MB complex compared with the MB-HSA complex.

The sonodynamic damage to protein in the presence of methylene blue (MB) and the various influencing factors including ultrasonic irradiation time and MB concentration on the damage of protein were studied by fluorescence and absorption spectra. In addition, the mechanisms of the synergistic effects of ultrasound and MB were studied by oxidation-extraction photometry with several reactive oxygen species (ROS) scavengers. The results indicated that the damage of protein induced by the synergistic effects of ultrasound and MB were more serious than those that ultrasound or MB alone was applied. The damage of protein could be mainly due to the generation of ROS. The damage degree of protein increased with the increase of ultrasonic irradiation time and MB concentration because of the increased quantities of ROS generation. Both (1)O₂ and ·OH were the important mediators of the ultrasound-inducing protein damage in the presence of MB.

1 RGD tripeptide as the cellular adhesion factor was synthesized by a combination of chemical and enzymatic methods in this study. First of all, Gly-Asp diamide was synthesized by a novel chemical method in three steps including preparation of L-aspartic acid dimethyl ester, chloroacetylation of L-aspartic acid dimethyl ester and ammonolysis of chloroacetyl L-aspartic acid dimethyl ester. Secondly, Porcine Pancreas Lipase (PPL) was used to catalyze the synthesis of Benzyl-Arg-Gly-Asp diamide in water-organic cosolvents systems. The reaction condition was optimized by examining the main factors affecting the yield of the tripeptide. The optimal reaction condition was set up as pH7.7, 15°C in 50% DMF for 8 h with the maximum yield of 76.4%. It was also found that 50% DMSO was another alternative with the tripeptide yield of 71.7%.

The precursor dipeptides of RGD (Arg-Gly-Asp), N-CBZ-Arg-Gly-NH2 and CBZ-Gly-Asp-NH2 were synthesized in reverse micellar system and organic solvent using several proteases in different forms under kinetical control. The synthesis reaction conditions for CBZ-Arg-Gly-NH2 and CBZ-Gly-Asp-NH2 catalyzed by chymotrypsin in AOT/isooctane reverse micelles were optimized by examining the effects of several factors including water content, temperature, pH, and reaction time on the dipeptide yields. The best yields for the syntheses of CBZ-Arg-Gly-NH2 and CBZ-Gly-Asp-NH2 were 87.3% and 80.8%, respectively. The dipeptide products were separated from the reverse micelles by using a silica gel column.

The precursor dipeptides of RGD, Boc-Arg-Gly-OEt and Ac-Gly-Asp-diOMe, were synthesized in three reverse micellar systems using different proteases. The reaction conditions for the Boc-Arg-Gly-OEt synthesis catalyzed by alcalase and for Ac-Gly-Asp-diOMe synthesis catalyzed by trypsin in AOT/isooctane reverse micelles were optimized by examining the effects of several factors including water content, temperature, pH, reaction time, and the enzymes on the dipeptide yields. The best yields for alcalase-catalyzed synthesis of Boc-Arg-Gly-OEt and trypsin-catalyzed synthesis of Ac-Gly-Asp-diOMe were 62.7% and 78.8%, respectively. Two other reverse micelle systems, Triton/ethyl acetate and HTAB/heptane/hexanol were also tested for the syntheses of the same dipeptides.

The surface figure precision of the primary mirror in a large-aperture telescope is a key factor to the imaging quality. With the finite-element software, the finite-element model is set up base on optimization of the lateral support system. When the primary mirror is supported in the vertical position, the surface figure deformations of the primary mirror were analyzed. The rigid body displacement is removed, the max deformation of the mirror face is 261nm, the surface figure deformation RMS value is 64.03nm, PV value is 251.03nm. The results may offer some important references for the designs in this area.

Bacteremia remains a significant cause of morbidity and mortality after kidney transplantation. This study was conducted to investigate whether the polymorphisms of tumor necrosis factor (TNF)-β, interleukin (IL)-1β, and IL-1 receptor antagonist (IL-1ra) gene predicted the susceptibility to bacteremia within the first 6 months after kidney transplantation.Subjects comprised 82 infected kidney transplant recipients and 60 non-infected kidney transplant recipients. Bacteremia was diagnosed in 16 of the 82 infected recipients. Genomic DNA from these 142 kidney transplant recipients was extracted from peripheral blood leukocytes. Regions containing the NcoI polymorphic site at position +252 of TNF-β gene and the AvaI polymorphic site at position -511 of IL-1β gene were amplified by polymerase chain reaction (PCR) and subsequently digested with NcoI and AvaI restriction enzymes, respectively. The polymorphic regions within intron 2 of IL-1ra gene containing variable numbers of a tandem repeat (VNTR) of 86 base pairs were amplified by PCR.Genotypic and allelic frequencies were similar between infected recipients and non-infected ones. Individual locus analysis showed that recipient TNF-β and IL-1ra gene polymorphisms were not associated with the presence of bacteremia (P = 0.684 and P = 0.567, respectively). However, genotype analysis revealed that recipient IL-1β-511CC genotype was strongly associated with susceptibility to develop bacteremia (P = 0.003). Recipient IL-1β-511CC genotype (odds ratio 5.242, 95% confidence intervals 1.645-16.706, P = 0.005) independently predicted the risk for bacteremia within the first 6 months after kidney transplantation.These findings indicate a critical role of IL-1β gene polymorphisms in susceptibility to bacteremia after kidney transplantation, which may be useful to screen for patients at higher risk for post-transplant bacteremias. Thus, the identified individuals can benefit from preventive treatment and a less potent immunosuppressive regimen.

To evaluate the effects of low molecular weight heparin (LMWH) and heparin-binding epidermal growth factor (HB-EGF) on the biological function of human trophoblast in first trimester.From Feb. 2011 to Nov. 2011, the trophoblast isolated from human first trimester chorionic villi was cultured in vitro. Based on variation of LMWH concentration, the trophoblast was classified into 0.025 U/ml group, 0.25 U/ml group, 2.5 U/ml group, 25 U/ml group and 250 U/ml group. In the mean time, based on treatment of heparin, the trophoblast was classified into LMWH group (0.25 U/ml), HB-EGF group (10 µg/L), combination group (LMWH at 0.25 U/ml + HB-EGF at 10 µg/L) and add with DMEM as control group. Cell proliferation was assessed by the methyl thiazolyl tetrazolium (MTT) test, which was showed with the mean absorbance as A value. Cell invasion was measured by transwell, which counted the number of cells migrated to the superficies inferia of filter membrane. Cell differentiation was assessed by the concentration of hCG secretion.Compared with control group, the trophoblast proliferation and invasion treated by LMWH at 0.025 U/ml did not show significant difference (P0.05). When treated by LWMH at 0.25 U/ml and 2.5 U/ml, trophoblast proliferation and invasion was increased significantly (P0.05). When LMWH at 25 U/ml and 250 U/ml, it could inhibit trophoblast proliferation and invasion (P0.05). When compared with A value of 0.44 ± 0.04 in control group, the increased A value were 0.51 ± 0.05 in LMWH group, 0.56 ± 0.04 in HB-EGF group and 0.69 ± 0.06 in combination group (P0.05). In the transwell test, the cell number were 511 ± 78 in LMWH group, 669 ± 67 in HB-EGF group and 872 ± 64 in combination group, which were significantly higher than 405 ± 67 in control group (P0.05), respectively. And the hCG concentration were (7143 ± 649) U/L in LMWH group, (11 762 ± 1059) U/L in HB-EGF group and (11 015 ± 1084) U/L in combination group, which showed statistical difference with (8182 ± 666) U/L in control group (P0.05).LMWH could modulate trophoblast proliferation, invasion, and differentiation. HB-EGF is one of important factors involved in effects of LMWH on trophoblast function.

Four kinds of supports were used to prepare immobilized papain using different methods: simple absorption on Celite, ionic absorption on CM-cellulose and QAE-Sephadex, and covalent cross-linking on egg white protein. The direct effects of the support on the catalytic properties of the enzyme were examined by studying the dependence of water content, pH, ionic strength, and reaction temperature on the yields of a model dipeptide Boc-Phe-ValOMe in ethyl acetate under thermodynamic control. It was found that the supports with low hydrophilicity demonstrated much higher catalytic activity by the enzyme than those with high hydrophilicity. Egg white protein was the best support with a good yield (94.5%) of the dipeptide. Papain and α-chymotrypsin immobilized on egg white protein were used to synthesize a number of dipeptides with Boc-Phe-XOMe showing different substrate specificity. Alcalase was used in the synthesis of some dipeptides containing hydrophilic amino acids and d -amino acids with reasonable yields.

Lateral support has a significant effect on the deformation of thin primary mirror. This paper deals with the analysis and optimization procedure on the “push-pull-shear” lateral support of thin meniscus mirror. Three steps were carried out in the lateral support optimization. Firstly a finite element model (FEM) was build for further analysis, then according to its structural characteristic, the ratio between the tangential force and the radial force was analyzed during the first optimization; In order to make the lateral forces with the same value, equal angle distance was changed to different angle distances during the second optimization, also lateral support position and magnitude of the lateral forces were given; during the last analysis, a portion of axial force was exerted at the inner ring, the response curve between the inner ring axial force and the RMS in Z direction of the mirror was plotted. The final result showed that the RMS value was decreased from 12.168nm to 3.253nm in Z direction. The optimization procedure provided a feasible way for lateral support of thin meniscus mirror.

Thermostable α-amylase from Bacillus sp-JF2 strain was found to have three active components (names α-amylase I, II, and III) with molecular weights of 110,000, 140,000, and 300,000, respectively. α-Amylase II was isolated and purified in the current work by different procedures from that for α-amylase I. α-Amylase II consists of two identical subunits (MW 70,000). The isoelectric point is 4.7. The temperature optimum is at 90°C and the pH optimum is 5.5. for the enzyme activity. The half-life of the enzyme at 90°C is 30 min, and the enzyme is stable over a pH range of 7.0–9.0. The Km value of the enzyme was estimated to be 3.3 mg ml−1. A considerable difference in amino acid composition was observed between α-amylase I and α-amylase II. The α-helix content of α-amylase II was calculated to be 51% from the circular dichroism spectrum. The number of Ca2+ binding to each molecule of α-amylase II was determined to be 10 by atomic adsorption.

To study the effect of Yuyin recipe, a Chinese composite recipe, on cultured human epithelial cell proliferation in vitro YYR in different concentrations was added separately into the keratinocyte CoLo-16 line, after the latter had been cultured 24 hrs, to be co-cultured for different periods of time (24–72 hrs). A blank control group was set up in the meantime. Effect of YYR with different concentrations and different acting time on keratinocyte proliferation was observed by MTT method YYR in different concentrations showed significant inhibitory effect on keratinocyte CoLo-16 line in concentration-dependent and acting-time-dependent manner Inhibition on over proliferation of epithelial cells may be one of the mechanisms of YYR in curing psoriasis.

To compare the difference of HBV DNA levels and HBV genotypes between the patients with primary hepatocellular carcinoma (HCC) and liver cirrhosis who infected with hepatitis B virus.Total 430 patients with hepatitis B were enrolled and further divided into the HCC group (210 cases) and liver cirrhosis group (HBV LC, 220 cases). The levels of HBV DNA and HBV genotypes were detected in all of the serum samples from the two groups, and the differences in the genotypes and virological markers between HCC patients and HBV LC patients were further analyzed.The positive rates of HBV DNA of HCC patients and HBV LC patients were 84.3% (177/210) and 94. 5% (208/220), respectively. The mean values of serum HBV DNA in HCC patients and HBV-LC patients were (5.06 +/- 1.01) log10 cps/ml and (5.36 +/- 1.13) log10 cps/ml, respectively. The positive rates of HBV DNA and the mean values of serum HBV DNA were higher in HBV-LC patients than those in HCC patients (P0.01). Furthermore, the main genotype was C in both groups and the distribution of genotype C and genotype B had no statistical difference.Mainly presented as a C genotype in both groups, the total levels of serum HBV DNA in HCC patients were lower than those in HBV-LC patients.

Objective To evaluate the effects of low molecular weight heparin (LMWH) and heparin-binding epidermal growth factor (HB-EGF) on the biological function of human trophoblast in first trimester. Design Control experiment. Setting Two academic-based reproductive centers. Patient(s) The first trimester human placentas (gestational age, 5–10 weeks) from patients who underwent electively induced abortions. Intervention(s) Cultured trophoblast treated with LMWH or LMWH and HB-EGF. Main Outcome Measure(s) The biological function (proliferation, invasion, and differentiation) of trophoblast and the interaction between LMWH and HB-EGF on trophoblast in vitro. Result(s) 1) At a dose of 0.25 IU/mL–2.5 IU/mL LMWH promoted trophoblast proliferation, enhanced their invasion, and increased hCG secretion. The LMWH had little effect or the opposite effect at other concentrations. These differences were statistically significant. 2) Combined use of LMWH and HB-EGF significantly promoted proliferation and invasion, but there was no difference in hCG secretion compared with solo LMWH or solo HB-EGF. Conclusion(s) The LMWH exerts a cytoprotective effect by regulating trophoblast proliferation, invasion, and differentiation. The HB-EGF is an important factor in the effects of LMWH on trophoblast function.