并非所有的干细胞分化产物功能都相同

据美国BIOCOMPARE科技新闻网（2007／9／3）报道，美国UCLA的干细胞生物学家YiSun以及霍华休斯医学院（Howard Hughes Medical Institute）的Thomas sudhof教授共同发表一份研究于8月6日的《美国国家科学研究院学报》（Proceedings of the National Academy of Science）期刊，研究中阐明两株来自于NIH的胚胎干细胞（embryonic stem cell，ES cell），会由于培养条件的不同而影响其分化的特性。

大鼠脊髓半切损伤后突触分化诱导基因产物SynDIG1的表达增强

目的探讨大鼠脊髓半切损伤后(spinal cord injury,SCI)突触分化诱导基因产物(synapse differentiation induced gene 1,Syn DIG1)的表达变化及意义。方法 SD大鼠随机分成对照组和脊髓损伤组(n=75),切断大鼠脊髓一半作为实验模型,只咬除椎板而不损伤大鼠脊髓作为对照模型。在手术后7、14、21、28、35天采集损伤区域的脊髓组织,用免疫荧光和免疫印迹技术检测各组各时间点Syn DIG1的蛋白表达,并且与半胱氨酸蛋白酶3(caspase-3)、神经生长蛋白43(GAP-43)等神经元特异性标志物做免疫荧光双标技术检测。结果在脊髓损伤后第7天就发现神经元有SynDIG1表达,在第28天达到高峰,随后维持在较高水平。通过免疫荧光双标技术发现脊髓损伤后Syn DIG1与GAP-43存在共表达。结论脊髓损伤后中期神经元大量表达Syn DIG1,激活了神经生长因子,促进神经元再生,有利于神经系统的修复。

Chemical Constituents from Starfish Asterias rollestoni

Aim To investigate novel bioactive and structural metabolites from marineorganisms. Methods Column chromatography in association with semi-preparative HPLC were used for theisolation of compounds. 1D and 2D NMR, IR, UV, and MS were employed for structure elucidation.Results From the butanol fraction of the 95% EtOH extract of the starfish Asterias rollestoni, a newcompound N^7 -2'-deoxypseudoxanthosine (1), along with sixteen known compounds, 2'-0-methyl-inosine(2), 2'-deoxyinosine (3), 2'-0-methylguanosine (4), inosine (5); thymine (6), uracil (7), thymidine(8), deoxyuridine (9), 2'-0-methyluridine (10), ( ― )-(1S, 3S)-1-methyl-1, 2, 3,4-terrahydro-β-carboline-3-carboxyl-ic acid (11), ( ― )-(1R, 3S)-1-methyl-1, 2, 3,4-tetrahydro-β-carboline-3-carboxylic acid (12) , ( ― )-(3S)- 1, 2, 3,4-tetrahydro-β-carboline-3-carboxylic acid (13), L-tryptophan (14), L-phenylalanine (15), 3-carboxyindole (16), and p-hydroxybenzoic acid (17) , have been isolated. Conclusion Compound 1 is a newnatural product, and compounds 8, 9 and 10 are isolated from natural sources for the first time, andthe known compounds except 14 and 15 are first reported from starfish Asterias rollestoni.

4-Desoxypicropodophyllin and 4’-Demethyl-4-desoxypicropodophyllin Obtained from System (CH_3)_3SiCl/NaI/MeCN

文献报道鬼臼脂素在 (CH3)3SiCl/Nal/MeCN 反应体系中得到氧化产物4-去氧-C环芳构化鬼臼脂素。而本文作者采用a-不饱和苦鬼臼脂素在同样的反应体系中却得到了部分还原产物C环氧化鬼臼脂素。根据鬼臼脂素和苦鬼臼脂素的结构差异,作者对发生这一现象的原因进行了报道和分析。

Separation and analysis of lignite bioconversion products

The bioconversion of coal at ambient conditions is a promising technology for coal processing, although the mechanisms of coal degradation are still not understood fully. In this work, the bioconversion of lig- nite was studied using a fungus isolated from decaying wood. The lignite samples were oxidized with nitric acid under moderate conditions and then the oxidized samples were placed on a potato medium with isolated fungus for lignite bioconversion. Lignite, oxidized lignite and residual products after bioconversion of lignite were sequentially extracted with petroleum ether, CS2, methanol, acetone and tetrahydrofuran （THt：）, and then each extract was characterized by gas chromatography-mass spectrom- etry （GC/MS）. The differences in composition and structure among the samples were inferred by compar- ing the differences between the extracts. The results show that aromatics with one or several benzene rings and their derivatives; and some long-chain alkanes containing oxygen decreased in the metha- nol-, acetone-, and THF-soluble fraction from residual lignite, whereas long chain or a few branched alkanes and small quantities of aromatic compounds increased in petroleum ether and CS2 soluble fractions.

Chemical Composition and Nutritive Value of Ramie Plant [Boehmeria nivea （L.） Gaud] and Its By-Products from the Textile Industry as Feed for Ruminants

In order to verify the possible use of ramie as feed for ruminants, a study was undertaken on the chemical and nutritional evaluation of different parts of this plant. Four stocks of samples picked up in two different periods （summer and autumn） were analyzed. The standard chemical composition was determined on the whole plant and on its parts, the study was particularly focused on leaves and tops, not used in fibre production and available as livestock feed. Organic matter enzymic digestibility （OMD） was determined on all the samples by a double step method based on cellnlolytic andproteolytic enzymes. The chemical analysis showed good crude proteins content in leaves, tops and whole plant： 17.00 ~ 1.52%, 15.25 ~ 0.77% and 11.79 ~ 3.32% on dry matter （DM） basis respectively and good acid （ADF） and neutral （NDF） detergent fibre fractions. Lignin and ash resulted high in all plant parts and organic matter （OM） was consequently low, ash analysis showed high calcium concentration, especially in leaves, with values exceeding 4% of din, whereas the other micro （except the lead） and macroelements were in a normal range. OMD and energy values resulted poor in leaves, tops and in the whole plant and lower than the other forages commonly used as feed for runninants, thus the utilisation of ramie plant and its by-products requests further investigations.

Inorganic Carbon Parameters Responding to Summer Hypoxia Outside the Changjiang Estuary and the Related Implications

The eutrophication, hypoxia and coastal acidification are attracting more and more attention. In this study, inorganic carbon parameters, including dissolved inorganic carbon （DIC）, total alkalinity （TA） and calculated partial pressure of CO2 （pCO2）, obtained from a summer cruise in August, 2009, were used to investigate their integrated response to biological processes accompanying the oxygen depletion in the areas off the Changjiang Estuary. According to the observations, the typical hypoxia occurred in the bottom water just outside the Changjiang Estuary with Dissolved Oxygen （DO） lower than 2.00 mg L^-1. The biological uptake in the surface water and the decomposition of organic matter in the bottom water were fully coupled with each other. The high concentration of Chl_a （Chl_a = 10.9μgL^-1） and DO （9.25 mgL^-1）, profoundly decreased DIC concentration 0828 μmolkg^-1） and elevated pH （8.42） was observed in the surface water. The correspondingly increased DIC and depletion of oxygen were observed in the bottom water. The semi-quantitative analysis proved that the locally-produced phytoplankton, determined by primary productivity, was deposited to the bottom and contributed about 76% of total amount of the organic carbon decomposition in the bottom. However, in the bottom hypoxia （DO = 2.05 mgL^-1） area observed in the Southern Zhejiang coastal water, the responding patterns of inorganic carbon parameters deviated from the previous one. The expanding of Changjiang Diluted Water （CDW）, the adding of Hangzhou Bay water （with high DIC concentration） and Coastal Current together modify the DIC background value in this area, and the local degeneration and upwelling process may also help to offset the local DIC removed by net biological uptake in surface water. In addition when the mixing occurring in autumn, which may break the summer stratification, the excess release of high DIC in the bottom water to the subsurface water could have an important influence on coastal acidification and the CO2 uptake capacity in this area.

Food Value of Soft Dates Cultivated in Tunisian Coastal Oases

Coastal date palm cultivars are interesting through their soft dates, their abundant and earliest production than continental cultivars. Maintaining bio-diversity in Tunisian oases has become a subject of first interest in date palm cultivation in Tunisia. Coastal oases still retain a very rich and varied plant biodiversity in comparison with the continental oases, weakened by the mono cultivation of ＂Deglet Nour＂ cultivar. Study of soft date＇s composition can make there well known to date consumers, help to valorize there and to help of sustainability of coastal oases ecosystem. Fresh dates from 15 cultivars was collected, dried by 80 ~C in 20-24 h. Acidity was determinate by pH meter. Sugars were appreciated by enzymatic method. Ash and minerals was calculated by photometer and spectrometer. Chemical date composition study showed that coastal date palm cultivars are predominantly rich of carbohydrates, have a low quantity of sucrose which gives them an important dietary value. Their pH varies from 5 to 6, classifies them as the best date quality for fresh consumption. Their richness in Total Nitrogen Matters and total minerals makes them at almost the same level as the other date palm eultivars analyzed by different authors in different areas of date palm production. Mineral composition showed that these dates are K and P-rich and relatively poor in Na and Ca.

The Roles of Plant Secondary Metabolites from Cowpea Floral Structures in Resistance to the Flower Bud Thrips

Floral structures of six cowpea （Vigna unguiculata） cultivars were analysed for secondary plant metabolites （polyphenols, terpenoids and flavonoids） to study their relationships with resistance to Megalurothrips sjostedti （Trybom）. Polyphenols varied significantly （P 〈 0.001） among the floral structures of the cultivars at the same growth stage. Significant negative correlations were obtained between polyphenols and damage indices （r = -0.57）, mean adult counts （r = -0.56） and mean larval counts （r = -0.64） of resistant cowpea cultivars especially in the late season, indicating that polyphenols play a significant role in cowpea resistance to M. sjostedti. High levels of polyphenols obtained from Sanzibanili and Sewe cultivars, coupled with highly significant correlations between the polyphenols and thrips population on resistant cultivars, and their damage indices, suggests that these polyphenols could be inhibitors or deterrents in this case. Terpenoid extracts （10 mg/mL） of IT90K-277-2, Sewe, Sanzibanili, TVu 1509 and KV - 404-8-1 racemes; KV ~ 404-8-I and TVu 1509 floral buds; IT90K-277-2, Sewe and Sanzibanili flowers caused significant （P 〈 0.001） larval mortalities, since mortality ranged between 56.7%-96.7%. Hence terpenoid extracts from floral structures of the cultivars are biologically active and confers antibiotic resistance to M. sjostedti larvae; this compound could be promising candidates for genetic transformation of cowpea cultivars.

Study on Zymomonas Mobilis Growth and Its Relationship with Glutaminase Production by Using Statistical Tools

Glutaminase is used industrially to enhance flavor and aroma and to enrich foodstuffs nutritionally. It also has potential for pharmaceutical application as anti-leukemia agent. The bacteria of Zymomonas mobilis has been studied for ethanol production, however, there is no study regarding glutaminase production. The aim of the present study was to establish the influencing factors for the growth of Z mobilis and its relationship with glutaminase production using statistical tools. Analysis of variance in blocks was carried out in a complete block design and the Tukey test demonstrated the importance of the components of the culture medium, absence of agitation and fermentation time. Minimum culture medium was used in the optimization varying the glucose concentrations （10, 30, and 50 g/L）, glutamine （0, 0.5 and 1g/L） and culture time （18, 24 and 30 hours）. Maximum production was obtained at 8.86 U/L glutaminase. Optimized conditions were used in the growth kinetics, where typical exponential growth was observed. Glutaminase production was shown to be related to biomass production.

Production and Nutritive Value of Calopo with Nitrogen and Phosphorus Fertilizer from Difference Sources

Calopogonium mucunoides （calopo） is one of forage legumes as protein and mineral sources for ruminant livestock in the tropics. However, most of the land in Indonesia that used for forage crops production characterized by acid pH, low in nitrogen and phosphorus. Phosphorus fertilizers have been used widely to improve soil fertility in Indonesia. As the high cost of superphosphate （SP）, the focus is now on rock phosphate （RP） fertilizer which relatively cheaper than SP, and it has high solubility in acid condition. Combination between nitrogen and phosphorus fertilizer from difference sources may be a promising technique to overcome those problems. A field experiment was conducted on a latosolic soil （low pH, nitrogen and low available Bray II extractable P）. The objective of the research is to evaluate the effect of combination between nitrogen and phosphorus fertilizer from difference sources on dry matter production and digestibility, nitrogen and phosphorus uptake of Calopogonium mucunoides （calopo）. Completely randomized block design with 9 treatments in 3 replicates was used in this experiment. The treatments were TO （control）, TI （SP）, T2 （RP）, T3 （urea）, T4 （ZA）, T5 （SP ＋ urea）, T6 （SP ＋ ZA）, T7 （RP ＋ urea）, T8 （RP ＋ ZA）. Size of plot was 2 m × 3 m, fertilized with 50 kg N/ha and 200 kg P2O5/ha, according to the assigned treatment. All plot received basal fertilizer of KCI （100 kg KzO/ha） and goat manure （5 ton/ha）. Calopogonium mucunoides was defoliated and nutritive value. Result showed that dry matter production on 90 days after planting and analyzed for dry matter production and nutritive value significantly influenzed by the treatments. Combination between N （ZA, urea） and P （SP, RP） fertilizer resulted dry matter production, nutrient uptake, and dry matter digestibility significantly higher compared to control, and NP fertilization separatedly. Combination of RP and N （urea, ZA） resulted in dry matter production, nutrient uptake, and dry matter digestibility non-significantly different compared to SP in combination with N （urea, ZA）. Therefore, RP could replace SP if combined with urea or ZA to increase production and nutritive value of Calopogonium mucunoides in acid latosolic soil.

Separation of Primary Alcohols and Saturated Alkanes from Fisher–Tropsch Synthesis Products

A method for separating primary alcohols and saturated alkanes from the products of Fisher-Tropsch synthesis is developed. The separation scheme consists of three steps： （1） the raw material is pre-separated by fractional distillation into four fractions according to normal boiling points; （2） appropriate extractants are selected to sep- arate the primary alcohols from the saturated alkanes in each fraction; （3） the extractants are recovered by azeotropic distillation and the primary alcohols in the extract phase are purified. Based on the proposed method, the total recovery rates of the primary alcohols and the saturated alkanes are 86.23% and 84.62% respectively. 2014 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.

Synthesis and application of covalent triazine framework/graphene hybrids for photocatalysis

In recent years,photocatalysis with efficient,low-cost and stable metal-free catalysts is one of the most promising technologies for non-polluting energy production and resource-economic environment purifying.Benefiting from the molecularly precise backbones,regular and homogeneous porosity,lightelement composition,nitrogen-rich system with unique electronic band structure of two-dimensional(2D)covalent triazine framework(CTF),as well as the huge specific surface area,superior thermal conductivity,excellent carrier mobility and mechanical properties of 2D graphene,CTF/graphene hybrid-based photocatalysts show great application potential in the field of photocatalysis.In this review,the recent development in synthesis of CTF/graphene hybrid-based photocatalysts,and their applications in photocatalytic water splitting for hydrogen production and photocatalytic degradation of pollutants are summarized.Firstly,we briefly describe the molecular structures,physicochemical properties,and synthetic strategies for CTF/graphene hybrid-based photocatalysts including solution mixing method,in-situ polymerization method and sol-gel method.We further assess the impact of different preparation methods on the structure,morphology,and interacting model between CTF and graphene in CTF/graphene hybrids.Following the various preparation process for CTF/graphene hybrid-based photocatalysts,these methods are analyzed and compared regarding their merits and demerits.Secondly,the functions of CTF/graphene hybrid-based photocatalysts obtained from different synthesis approaches that enhance the catalytic activity for photocataLytic hydrogen evolution and photocatalytic degradation of pollutants are discussed from the three aspects of light harvesting,charge separation and transfer,and surface catalysis.Particular focus has been placed on the catalytic mechanisms of CTF/graphene hybridbased photocatalysts for enhanced photocatalytic hydrogen evolution and improved photocatalytic degradation of pollutants.Then the rational manipulation of selection and building units of CTF,connecting bonds between CTF and graphene,dimensions and pore structures of CTF/graphene hybrids in design of CTF/graphene hybrid-based photocatalysts is discussed,aiming to inspire critical thinking about the effective strategies for modification of photocatalysts rather than the development of novel materials.In the end,the challenges and some future trends of CTF/graphene hybrids as advanced photocatalysts are also discussed from three aspects:catalysts design,performance stability and reaction mechanism.The approaches offer potential solutions to address the challenges of largescale production,catalyst activity and stability in the further research and development of new types of metal-free hybrid photocatalysts with high efficiency.

Characterization of chemical constituents and in vivo metabolites of Kai-Xin-San prescription by HPLC/DAD/ESI-MS^n

This work aims to elucidate the chemical constituents of Kai-Xin-San（KXS） and its metabolites in rat plasma.KXS extracts were separated on an Agilent HPLC SB-C 18 column,analyzed by ion-trap tandem mass spectrometry and high-accuracy qTOF mass spectrometry in negative ion mode.A total of 39 compounds,including 11 ginsenosides,14 Polygala saponins,5 sucrose esters,8 oligosaccharide esters and 1 xanthone were characterized from KXS.Fifteen of them were confirmed by reference standards.No constituents were detected from Poria or Acori Tatarinowii Rhizoma.After oral administration of KXS（7 g/kg）,10 ginsenosides and 18 Polygala compounds were detected in rat plasma.This study indicates that ginseng saponins,Polygala saponins and saccharide esters could be the major effective components of KXS prescription.

Fabrication and thermal decomposition of glycidyl azide polymer modified nitrocellulose double base propellants

Glycidyl azide polymer （GAP） with the advantages of non-volatility and excellent thermal stability is a candidate as a re- placement for nitroglycerine （NG） in a double base propellant. The GAP-NC double base propellants were formulated with GAP and nitrocellulose （NC） fibers. Tensile test and SEM characterization indicated that GAP-NC propellants had a homoge- neous structure. Thermogravimetric analysis of GAP-NC propellants revealed that the onset decomposition temperature reached a high level ranging from 192.9 to 194.6 ℃, which indicated that the substitution of NG with GAP contributed to the safe storage and process operations for double base propellant. The result analysis of decomposition products of GAP-NC propellants showed that the main gas decomposition products of the propellants were NO, NO〉 CO, CO2, NH3, CH4, HCN, N2 CH20 and C2H40. The thermal decomposition process of the specimens was proposed.

CsOH catalyzed aerobic oxidative synthesis of p-quinols from multi-alkyl phenols under mild conditions

p-Quinols are ubiquitous structural motifs of various natural products and pharmaceutical compounds,and versatile building blocks in synthetic chemistry.The reported methods for the synthesis of p-quinol require stoichiometric amounts of oxidants.Molecular oxygen is considered as an ideal oxidant due to its natural,inexpensive,and environmentally friendly characteristics.During the ongoing research of C–H bond hydroxylation,we found that multi-alkyl phenols could react with molecular oxygen under mild conditions.Herein,we describe an efficient oxidative de-aromatization of multi-alkyl phenols to p-quinols.1 atm of molecular oxygen was used as the oxidant.Many multi-alkyl phenols could react smoothly at room temperature.Isotopic labeling experiment was also performed,and the result proved that the oxygen atom in the produced hydroxyl group is from molecular oxygen.