Effect of Cl- on photosynthetic bicarbonate uptake in two cyanobacteria Microcystis aeruginosa and Synechocystis PCC6803

Photosynthetic inorganic carbon utilization was investigated in two cyanobacteria Microcystis aeruginosa and Synechocystis PCC6803 grown in standing culture. Photosynthetic rates for the two algae reached about 10 times the theoretical CO₂ supply rate at low dissolved inorganic carbon (DIC) of 100 μmol/L, and the rates were unaffected by the addition of 20 mmol/L Na⁺, indicating that the two algae possessed Na+-independent HCO^-₃ utilization for photosynthesis under low DIC. Their photo- synthetic rates at low DIC were inhibited by higher Cl^- and the degrees of inhibition were increased with the rise of CI^- concentration, and in the presence of Diphenylamine-2-carboxylate (DPC), a reported Cl^- channel inhibitor, the rates decreased by 74%－82%, implying that putative DPC-sensitive Cl^- channels participate in Na+-independent HCO₃^- uptake for photosynthesis. The experiment of intracellular 14C-DIC accumulation for photosynthesis showed that internal DIC pools decreased by about 80% with 200 μmol/L DPC and by 64%－70% with 100 mmol/L Cl^-. The experiment of chlorophyll a fluorescence quenching showed that initial rates and extents of fluorescence quenching obviously decreased with 200 μmol/L DPC or 100 mmol/L Cl^-. The two experiments gave further evidence that putative DPC-sen- sitive Cl^- channels participate in Na+-independent HCO^-₃ uptake for photosynthesis in the two algae grown in standing culture.     

Effect of Nano red elemental selenium on GPx activity of broiler chick kidney cells<Emphasis Type="Italic">in vitro</Emphasis>

A new selenium source, Nano red elemental selenium (Nano-Se) was used to study the effect on the GPx activity of broiler chick kidney cells (BCKC)in vitro, Sodium selenite (Na₂SeO₃) and seleno-1-methionine (Se-Met) were used as the controls. The results showed that the effects of three kinds of Se forms on the GPx activity of BCKC were accordant (p>0.05) compared with each other at 0.01. 0.05 and 0.10 μmol/L Se concentrations treatments. In the range of 0.00–0.10 μmol/L Se concentrations, the GPx activity increased with elevation of Se concentrations in medium. For the three kinds of Se forms, the GPx activity reached the climax at 0.10 μmol/L Se concentration. At 0.20 and 0.30 μmol/L Se concentrations, the influnces of three kinds of Se forms were not accordant with one another. For Nano-Se, the GPx activity at 0.20 and 0.30 μmoi/L Se concentrations remained the same as that at 0.10 μmol/L Se concentration treatment. For Se-Met, the GPx activity at 0.20 μmol/L Se concentration treatment remained the same with 0.10 μmol/L treatment; the GPx activity at 0.30 μmol/L Se concentration treatment was declined significantly (p<0.05) compared with 0.10 or 0.20 μmol/L treatment. For Na₂SeO₃, the GPx activity falled gradually with Se concentration increasing from 0.10 μmol/L to 0.30 μmol/L, and at 0.30 μmol/L Se concentration treatment, the GPx activity was less than the original of BCKC. The results implicated, on the GPx activity of BCKCin vitro, the ranking of width range of the most suitable Se concentration for nutrition curve of the three Se formes is Nano-Se>Se-Met>Na₂SeO₃. Foundation item: Supported by the Key Item of the Science and Technology Bureau of Zhejiang Province (021122680) Biography: Xu Bao-hua (1966-), male, Associate professor, Ph. D. research direction: nanobiology and animal nutrition.     

Coastal acidification in summer bottom oxygen-depleted waters in northwestern-northern Bohai Sea from June to August in 2011

Dissolved oxygen(DO) and pH in the central part of the Bohai Sea were surveyed in late June and late August,2011.During the June cruise,the bottom DO was in the range of 215-290 μmol-O2 kg-1(i.e.85%-115% of the saturation level),and the bottom pH was in the range of 7.82-8.04 on the total-hydrogen-ion scale.In August,however,both the bottom DO and the pH had significantly declined in the northwestern-northern near-shore areas,where the water depth was no more than 35 m.The lowest bottom DO was 100-110 μmol-O2 kg-1(only 44%-47% of the June DO values) in the northern near-shore area,where the bottom pH was 7.64-7.68 on the total-hydrogen-ion scale(0.16-0.20 units lower than the June pH value).The largest decreases in DO and in pH were observed in the northwestern near-shore bottom waters,corresponding to declines of 170 μmol-O2 kg-1(as high as 59% of the June DO value) and 0.29 pH units,respectively.The greatest pH decline of 0.29 pH units meant that the total-hydrogen-ion concentration doubled in the bottom waters from June to August.Based on field measurements of bottom DO/pH combined with a simplified model simulation,we suggest that respiration/remineralization-derived CO2 increased the acidity in the bottom oxygen-depleted waters of northwestern-northern near-shore areas in the Bohai Sea as a result of coastal red tides and/or marine aquaculture.This aquatic chemistry is suggested to be partially responsible for scallop-breeding failures in the northwestern Bohai Sea in summer 2011.     

Applications of crown ether cross-linked chitosan for the analysis of lead and cadmium in environmental water samples

A new type of crown ether cross-linked chitosan was synthesized by the reaction of chitosan with 4,4′-dibromodibenzo-18-crown-6 (Br-DBC). Its token structure was analyzed with FT-IR and NMR and the adsorption behaviors for lead and cadmium in environmental water samples by FAAS were studied. In addition the best analysis conditions were discussed and the adsorption mechanism was explained. As the enrichment factor is above 100, both recoveries are 94%–106%, the detection limits of lead and cadmium are 0.5μg·L⁻¹ and 0.04 μg·L⁻¹ and the relatively standard deviations of lead and cadmium are 3.1% and 2.8% respectively, this new method was successfully applied to the determination of environmental water samples. This method is fast and simple and it greatly enhances the determination ability of FAAS for lead and cadmium. Foundation item: Supported by the State Education Committee Doctoral Foundation (No. 2000048615) Biography: Tang Yu-rong(1943-), female, Associate professor, research direction: trace elements analysis.     

Study on the flow injection micro-column pre-separation system coupled with high performance liquid chromatography for the determination of ecdysterone in traditional Chinese medicine

A flow injection (FI) micro-column system coupled with high performance liquid chromatography (HPLC) was proposed for the pre-separation and determination of active organic component (ecdysterone) in traditional Chinese medicine, Loulu. The factors influencing separation performance were investigated and optimized. Under the optimal conditions, the contents of ecdysterone in Loulu were determined by HPLC system using MeOH-H₂O (40∶60,V/V) as the mobile phase at a flow rate of 1.0 mL/min. The calibration curve was linear in the range of 0.5∼100 mg/L of ecdysterone concentrations. The detection limit of the analyte was 0.11 μmol/L (3σ) with a precision of 0.38% RSD (n=7,c=10.0 mg/L). The average recovery of the method was 98.7%. The proposed method has been applied to determine ecdysterone in practical samples, and the determined values by both external standard method and standard addition method were in good agreement. Compared to the traditional solid extraction method, the system proposed has the advantages of simple procedure, good reproducibility, minimum volume requirement, reduction of matrix interference and low contamination risk. Foundation item: Supported by Education Ministy Foundation for Chinese Returned Scholars and Nature Science Foundation of Hubei province (98J054). Biography: SHUAI Qin (1963-), famale, Ph.D. Candidate.     

The compositions, sources, and size distribution of the dust storm from China in spring of 2000 and its impact on the global environment

The average mass concentration of the aerosols in Beijing during the dust storm in the spring of 2000 was ~6000 mg·m^-3, ~30 times as high as that in the non-dust storm days. The enrichment factors of the pollution elements As, Sb and Se were higher than those in the non-dust storm days. This indicated that As, Sb and Se resulted from the pollution sources of those areas, through which the dust storm passed during their long-range transport, in addition to the local pollution sources in Beijing. The enrichment factors of the Pb, Zn, Cd and Cu were much less than those in the non-dust storm days, suggesting that the local pollution sources in Beijing area contributed to them mostly. The enrichment factors of elements Al, Fe, Sc, Mn, Na, Ni, Cr, V and Co were close to 1, showing that these elements originated from crust. The concentration of S in the dust storm was ~10 mg·m^-3, 4 times as high as that in non-dust storm. S in the aerosols resulted from the adsorption of gaseous SO₂ and the consequent transformation on it. The aerosols of the dust storm contained 16.1% and 76.9% of fine particles with the sizes less than 2.1 and 9.0 mm, respectively, while it had a large number of coarse particles. It was noted that a considerable portion of Fe(Ⅱ) was detected from the dust storm. Fe(Ⅱ) could easily dissolve in seawater to be nutrient for phytoplankton and would lead to the increase of the emission of dimethylsulfide (DMS) from the ocean. The feedbacks of Fe coupled with S in atmosphere might be the important mechanism that would affect the primary productivity in Pacific and/or the global climate change.     

Origin of middle Miocene leucogranites and rhyolites on the Tibetan Plateau: Constraints on the timing of crustal thickening and uplift of its northern boundary

Leucogranites play a significant role in understanding crustal thickening, melting within continental collisional belts, and plateau uplift. Field investigations show that Miocene igneous rocks from the Hoh Xil Lake area mainly consist of two-mica leucogranites and rhyolites. We studied the Bukadaban two-mica leucogranites and the Kekao Lake, Malanshan and Hudongliang rhyolites by zircon U-Pb, muscovite and sanidine 40Ar/39Ar geochronology, and whole-rock geochemical and Sr-Nd isotopic analysis. Results yielded crystallization and cooling ages for the Bukadaban leucogranites of 9.7±0.2 and 6.88±0.19 Ma, respectively. Extrusive ages of the Kekao Lake and Malanshan rhyolites are 14.5±0.8 and 9.37±0.30 Ma, respectively. All rocks are enriched in SiO2 (70.99%-73.59%), Al2O3 (14.39%-15.25%) and K2O (3.78%-5.50%) but depleted in Fe2O3 (0.58%-1.56%), MgO (0.11%- 0.44%) and CaO (0.59%-1.19%). The rocks are strongly peraluminous (A/CNK=1.11?1.21) S-type granites characterized by negative Eu anomalies (δ Eu=0.18-0.39). In also considering their Sr-Nd isotopic compositions (87Sr/86Sri=0.7124 to 0.7143; δ Nd (9 Ma) =-5.5 to -7.1), we propose that these igneous rocks were generated through dehydration melting of muscovite in the thickened middle or lower crust of northern Tibet. Melting was probably triggered by localized E-W stretching decompression in the horse tails of Kunlun sinistral strike-slip faults. Reactivation of the Kunlun strike-slip faults, accompanied by emplacement of leucogranite and eruption of rhyolite in the Hoh Xil Lake area, indicates that large-scale crustal shortening and thickening in northern Tibet mainly occurred before 15 Ma. In addition, these findings suggest that the northern Tibetan Plateau attained its present elevation (~5000 m) at least 15 Ma ago.     

Molecularly imprinted polymer for theophylline retention and molecular recognition properties in capillary electrochromatography

0　IntroductionMolecularimprinting[1 ] isatechniquebasedoncreatingcavities,inahighlycross linkedpolymermatrix ,thatcorrespondtothesizeandshapeoftheprintmolecule .Themolecularrecognitioneffectisaconsequenceofthepresenceinthepolymerizationmixtureoftemplatemoleculescapableofestab lishingnon covalentinteractionswithmonomerandcross linkers.Molecularlyimprintedpolymers (MIPs)havebeenusedaschromatographicstationaryphases[2 ,3] includingcapillaryelec trochromatography ,asselectivematerialsforbiosenso…     

Involvement of Oxidative Stress and Down-Regulation of Bcl-2 in Arachidonic Acid-Induced Apoptosis in HUVECs

0IntroductionAraacicdhi,diosn fiocu ancidd p(reAdAo)m i,naanntelsys eantt itahle p sonl-y2u npsoastiutiroante doff actetl-ylular phospholipids . Normal free AAconcentrationin humanblood ranges from5 .8μmol/Lto 49 .3μmol/L[1].It is re-leased mostlythroughactivation of phospholipase A2by physi-ological and pathological sti muli[2]. Free AAcan be metabo-lizedinto various eicosanoids via specific enzymes such as cy-clooxygenases ( COX) , lipoxygenase and cytochromesP-450[3]. During AA met…     

Crystallization kinetics of sea-salt aerosols studied by high-speed photography

Morphological changes with decreasing relative humidity(RH) of supersaturated sea-salt aerosol droplets on a quartz substrate were observed using a high-speed video-camera.Stable gypsum(CaSO4·2H2O) or the metastable hemihydrate(CaSO4·0.5H2O) were precipitated as the RH decreased.The dynamic process of crystal growth under steady-state humidity was studied by controlling the RH;the metastable hemihydrate was precipitated at 70.5%-77.1% RH,and the apparent crystal growth rate was between 1.42 and 2.33 μm3/s.Stable gypsum was formed at 80.7%-82.2% RH,and the apparent crystal growth rate was between 0.70 and 0.81 μm3/s.     

The recognition of adakite-type gneisses in the North Dabie Mountain and its implication to ultrahigh pressure metamorphic geology

Adakite[1] is an igneous rock generated by the partial melting of subducting ocean slab in an island arc setting. Meanwhile, residuals of the slab-melting are transformed to eclogite or garnet-amphibolite during a slab subduction process. This note reports the adakite-type grey gneisses discovered in the North Dabie Mountain. These adakitic rocks are characterized by high Al2O3 (14.97%-17.56%), Sr (545-941 μg/g), Sr/Y (44.71-218.98), La/Yb (16.70-97.50), and low Y (3.32-12.19?μg/g), Yb (0.31-1.34 μg/g), Sc (0.92-4.2 μg/g), as well as positive Sr anomaly but absent or positive Eu anomaly. They are different from the low aluminum grey gneisses with low Al2O3 (13.73%-14.38%), Sr (262-409μg/g), Sr/Y (6.46-15.97) and La/Yb (1.90-22.60), high Y(21.79- 36.24 μg/g), Yb (2.00-5.59 μg/g) , Sc (8.30%-12.70%), and negative Sr, Eu anomaly in the North Dabie Mountain. The adakite-type grey gneisses in the North Dabie Mountain were most probably formed by the partial melting of subducting ocean slab before the Indo-Chinese epoch. We suggest that the subducting of an ocean slab took place prior to the incorporation between the Yangtze and North China plates in the Indo-Chinese epoch, resulting in formation of adakite-type igneous rocks and some ultrahigh pressure eclogites related to the subducted ocean slab. Therefore, besides the ultrahigh pressure metamorphism of the Indo-Chinese epoch, some ultrahigh pressure ecoglits were most likely formed prior to the Indo-Chinese epoch in the Dabie Mountain. In addition, the adakite-type grey gneisses with arc origin occur in the North Dabie Mountain, inferring that the Yangtze plate subducted down below the North China plate and the main suture zone between the two plates was likely along the southern side to the North Dabie Mountain.     

Large selenium isotopic variations and its implication in the Yutangba Se deposit, Hubei Province, China

The selenium isotopic ratios have been measured in the Yutangba Se deposit, Hubei Province, China. The results show that the δ 82/76SeNIST values vary from -12.77‰ to 4.93‰, which is the largest Se iso- topic variation found so far in natural terrestrial samples. The sample Ytb-5 of high-selenium carbona-ceous shale has the lightest Se isotopic composition with a δ 82/76SeNIST value of -12.77‰. On the basis of variations of Se isotope in the deposit along with other geological and geochemical evidence, the "redox model" is suggested to favor the explanation of the occurrence of native Se in the deposit. The application to the Yutangba Se deposit with the discovery of large Se isotopic fractionation for natural samples indicates the potential of Se isotope as a new geochemical tracer.     

Myoglobin as Mimetic Enzyme and Its Analytical Application in Determination of H2O2

0 IntroductionSltougdiiceasl csoynstceermnsin gharveeac btieveen o txhyeg ei nm psopretcaienst ( oRbjOecSt) iinn bbiioo--medicine and analytical chemistry in recent years[1-4]. Manyi mportant life phenomena and diseases are relatedtotheinter-mediates of ROS[5-7].ROS have beeni mplicated as ani mpor-tant causative factor in cell damage,including apoptosis andnecrosis . Their proposed actions comprise lipid peroxidation,DNAdamage,the mitochondrial respiratory chain destructionand protein mo…     

Synthesis and characterization of BiFeO3 nanotube arrays and Y-junction BiFeO3 nanotubes

Multiferroic BiFeO₃ (BFO) nanotube arrays (∼100 nm in diameter and ∼50 μm in length) were synthesized by the sol-gel method utilizing the anodic aluminum oxide (AAO) membrane technique. The microstructure and chemical components of the BFO nanotubes were investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectrometer (XPS). The BFO nanotubes exhibited polycrystalline microstructures. The novel Y-junction BFO nanotubes were simultaneously fabricated. Supported by the National Natural Science Foundation of China (Grant No. 90306010), Program for New Century Excellent Talents in University (Grant No. NCET-04-0653) and National Basic Research Program of China (Grant No. 2007CB616911)     

Effect of cadmium and herbicides on the growth,chlorophyll and soluble sugar content in rice seedlings

To investigate the combined effects of Cd^2＋ （ 0,10,100,500 μmol/L） , acetochlor （AC） （0,1.6,4.0,8.0μmol/L）, and bensulfuronmethyl （BSM） （ 0,0.16,0.40,0.80 μmol/L） on the biomass,leaf soluble sugar, total chlorophyll （chl） content, chl a/b ratio, and Cd content in roots and shoots in the rice seedlings, pot culture experiments were conducted with rice （Oryza sativa L. ） cultivar Jinyou 402. The results showed that the Cd and AC combined treatment （Cd＋ AC treatment） significantly inhibited the growth of the roots and shoots. The root dry weight/shoot dry weight （RDW/SDW） ratio, total chlorophyll content and chl a/b ratio decreased by 41%, 50%, 56% , respectively, in comparison with the control, as well as the leaf soluble sugar content, plant dry weight /plant fresh weight （PDW/PFW） ratio increased by 284% and 44% , respectively. Cd content in the roots and shoots had a decreasing tendency with the increasing concentration of AC under the Cd＋AC treatment. The Cd and BSM combined treatment （Cd＋BSM treatment） had a similar result to the Cd＋AC treatment. The results suggest that the toxicity of Cd to rice seedlings has been enhanced due to its combination with herbicides.     

Rapid classification ofBacillus isolates using RAPD technique

This paper describes the typing of selectedBacillus strains from environmental origin and ATCC type strains. The objective of the study was to evaluate the usefulness of PCR-fingerprinting using Randomly Amplified Polymorphic DNA (RAPD) as a method for classifying members of the genusbacillus. Our experiments show that the levels of similarity of 69%∼90%, 40%∼60% were observed between the members of the same species and among the species of genusBacillus, respectively. In a dendrogram showing the positions of 28 strains, these strains were clearly seperated into distinct species, 13 of which are corresponding to type strains used in this study. These results suggest that RAPD analyses is a simple and powerful method for species identification and delimitation. Supported by the National Natural Science Foundation of China Yi Qingming: born in Apt. 1938, Professor     

Study on growth of coarse grains of diamond with high quality under HPHT

The growth of coarse grains of diamond was observed with graphite as carbon source and Fe₈₀Ni₂₀ alloy powder as catalyst at HPHT in a China-type SPD 6×1670T cubic high-pressure apparatus with highly exact control system. To synthesize coarse grains of diamond crystal with high quality, advanced indirect heat assembly, powder catalyst technology and catalyst with optimal granularity were used. Especially the nucleation of diamond and the growth rate were strictly controlled by the optimized synthesis craft. At last, diamond crystals (about 0.85 mm) in the perfect hex-octahedron shape were successfully synthesized at ~5.4 GPa and ~1360℃ in 60 min. The characteristic of crystal growth with powder catalyst technology under HPHT was discussed. The results and techniques might be useful for production of coarse grains of diamond.     

Holocene climatic and environmental changes recorded in Baahar Nuur Lake core in the Ordos Plateau, Inner Mongolia of China

A 5.3 m lake core was drilled in Baahar Nuur Lake in the Ordos Plateau, and measurements of meangrain size, organic δ 13C (δ 13Corg), organic carbon content (TOC), C/N, carbonate content, carbonate δ 13C(δ 13Ccar) and δ 18O (δ 18Ocar) were conducted for retrieving the Holocene chronosequence of climaticchanges based on 15 AMS 14C dates. The record documented four major stages of climate change inthe Ordos Plateau: (IV) a cold and dry condition before ～7.65 14C ka BP; (III) a warm and humid stagebetween ～7.65 and ～5.40 ka BP; (II) a generally drier and cooler climate since ～5.40 ka BP with twohumid events occurring from ～4.70 to ～4.60 ka BP and from ～4.20 to ～3.70 ka BP, and (I) a dry climatecharacterized by complete desiccation of the lake after 3.70 ka BP. Stage III can be further divided intothree sub-stages: (IIIa) a warm and humid episode from ～7.65 to ～6.70 ka BP, (IIIb) a warm and relativelydry episode from ～6.70 to ～6.20 ka BP, and (IIIc) the magthermal and maghumid episode of the Holo-cene from ～6.20 to ～5.40 ka BP.     

The fourier transformations of positive distributions on lorentz groupSO (3, 1)

With the aid of Plancherel-Godement Theorem, we prove that every positive distributionT onSO (3, 1) which is bi-invariant underSO(3) corresponds to a measure μ on ω=∝σC|s(2-s)>=0∝, and μ can be decomposed intoμ=μ ₁+μ ₂, whereμ ₁ is a bounded measure on 0<=s<=2 andμ ₂ is slowly increasing measure on (sχC|Re(s)=1)} Foundation item: Supported by the National Natural Science Foundation of China (19871065) and Hua Cheng Mathematics Science Foundation. Biography: Zhu Li (1976-), male, Graduate student, research interest: partial differential equation     

Crystallization dynamics of supersaturated NaClO4 aerosols studied by high-speed photography

Single supersaturated NaClO4 aerosol droplets on a quartz substrate were observed by a high-speed video camera for their morphologic changes with decreasing relative humidity （RH）. The supersaturated droplets were found to form anhydrous NaClO4 at -10% RH. Three stages were roughly observed in this process, i.e., the main stem appearance, primary and secondary branches growth, and the deep dehydration. The main stem grew steadily and finished in 120 ms. Affected by both crystal precipitation and water evaporation, primary branches grew for 1200 ms, accompanied by a slower growth of secondary branches. The deep dehydration was more complicated, and lasted for a longer time.