First Report of Pestalotiopsis mangiferae and P. vismiae Causing Twig Dieback of Myrica rubra in China

Chinese bayberry (Myrica rubra Siebold & Zucc.), an evergreen fruit tree, is widely grown in southern China. In 1999, severe twig dieback was observed on M. rubra in Taizhou and it spread to several major M. Rubra-producing areas of Zhejiang covering more than 6,000 ha by 2011. Symptoms were usually observed from June to November and first appeared as chlorosis of leaves and leaf drop, followed by the formation of dark brown lesions covered with white mycelia surrounding leaf scars. The lesions can extend to the whole twig and tree causing discoloration of the xylem. In most cases, infected trees die within 1 to 4 years. Two distinct fungi totaling 46 isolates were isolated from the surface-disinfested diseased twigs and cultured on potato dextrose agar (PDA) at 28°C. An isolate of each fungus, designated as C1 and B1, was characterized further following 10 days of growth on PDA at 28°C. C1 formed zonate, white colonies and black, acervular conidiomata with the conidia aggregated on acervuli as a creamy mass. Isolate B1 formed nonzonate, white colonies and black, acervular conidiomata with the conidia aggregated on acervuli as droplets. Conidia for each isolate were fusiform with five cells; one hyaline apical cell, one hyaline basal cell, and three, dark brown median cells. Conidia ranged from 17.8 to 25.2 × 6.7 to 9.2 μm for C1 and 21.2 to 27.8 × 4.3 to 7.5 μm for B1. There were two to three hyaline, filamentous appendages (9.8 to 23.5 μm long for C1 and 10.5 to 25.5 μm long for B1) attached to each apical cell, and one hyaline appendage (3.5 to 7.2 μm long for C1 and 3.0 to 6.8 μm long for B1) attached to each basal cell. The cultural and morphological characteristics of C1 (16 isolates) matched the description for Pestalotiopsis mangiferae while B1 (27 isolates) matched the description for P. vismiae (2). The PCR-amplified and sequenced internal transcribed spacer (ITS) region of the ribosomal DNA (ITS1-5.8S-ITS2) for isolate C1 (GenBank Accession No. JQ281542) and B1 (GenBank Accession No. JQ281543) were 99 and 100% homologous to that of the P. mangiferae isolate MM 102 (GenBank Accession No. GU722595) and P. vismiae isolate xsd08116 (GenBank Accession No. FJ481027), respectively. For pathogenicity tests, nine healthy detached leaves and 12 potted plants of M. rubra were wound inoculated with sterile water (control) or conidial suspensions (10⁵ conidia per ml; 20 μl on each site) of C1 and B1, respectively, and maintained with relative humidity of more than 90% under fluorescent light at 28°C. Tests were performed twice. Necrotic lesions, resembling those that occurred in the field, were observed on all inoculated detached leaves and 33.3% of C1 and 25% of B1 inoculated potted plants 10 and 30 days following inoculation, respectively, while the controls remained healthy. Two fungi were reisolated from the lesions with identical morphology to the initial C1 and B1 inoculums. Therefore, P. mangiferae and P. vismiae were determined to be the causal agent for twig dieback of M. rubra in China. Pestalotiopsis spp. were previously reported as pathogens of loquat (4), mango (3), and blueberry (1) causing economic loss. To our knowledge, this is the first report of twig dieback disease of M. rubra caused by P. mangiferae and P. vismiae. References: (1) J. G. Espinoza et al. Plant Dis. 92:1407, 2008. (2) Q. X. Ge et al. Flora Fungorum Sinicorum. Vol. 38, Pestalotiopsis. Science Press, Beijing, 2009. (3). Y. Ko et al. Plant Dis. 91:1684, 2007. (4). A. E. Perelló and S. Larran. Plant Dis. 83:695, 1999.

Solvothermal route to S-deficient CoS nanoplates and their cathodoluminescence and magnetic properties

A facile solvothermal method was developed to fabricate CoS nanoplates using ethylenediamine as solvent. The microstructure characterizations indicate that the CoS nanoplates have well-crystalline hexagonal phase and regular hexagonal or pentagonal shape. The XPS and ICP-AES measurements confirm the chemical composition of nanoplates is S-deficient CoS0.921. Cathodoluminescence spectra of both a large area of the nanoplates and individual nanoplate show broad emission bands centered at 615 nm. Magnetic measurements including magnetization dependence of temperature and magnetic hysteresis loops reveals that the CoS nanoplates exhibit room-temperature ferromagnetic behavior. It is found that intrinsic point defects mainly as V(s), Co(i) and/or the complex defects of V(s) and Co(i) should be responsible for both the broad emission band and the unique ferromagnetism.

Cloning of the surface layer gene sllB from Bacillus sphaericus ATCC 14577 and its heterologous expression and purification

A cDNA fragment encoding the S-layer protein SllB cloned from Bacillus sphaericus ATCC 14577 was expressed on the surface of E. coli BL21 (DE3) cells and confirmed by the square lattice structure at the nanoscale level. The amplified gene fragment designed with PCR primers from a specified reference sequence (GenBank accession no. AJ849550) showed a high degree of sequence identity with the known sequences for S-layer protein. The best alignment scores were seen in B. sphaericus strains JG-A12 and NCTC9602, which code for a pre-form protein with a predicted cleavage site located between the two alanine residues 31 and 32. After this signal peptide sequence was removed, the mature protein had a molecular mass of 116.2613 kDa and a theoretical pI of 5.40. Further bioinformatic analysis revealed three S-layer homology (SLH) domains in the N-terminus of the mature protein, positioned at the 1–61, 63–128 and 137–197 residues. The mature S-layer protein was composed of alpha helices (24.86%), extended strands (27.01%), and rich random coils (48.13%). Bioinformatics-driven characterization of SllB may provide scientific evidence for further application of this gene in the fields of nanobiotechnology and biomimetics in the future.

Plant height affects Fusarium crown rot severity in wheat

Effects of plant height on Fusarium crown rot (FCR) disease severity were investigated using 12 pairs of near-isogenic lines (NILs) for six different reduced height (Rht) genes in wheat. The dwarf isolines all gave better FCR resistance when compared with their respective tall counterparts, although the Rht genes involved in these NILs are located on several different chromosomes. Treating plants with exogenous gibberellin increased FCR severity as well as seedling lengths in all of the isolines tested. Analysis of the expression of several defense genes with known correlation with resistance to FCR pathogens between the Rht isolines following FCR inoculation indicated that the better resistance of the dwarf isolines was not due to enhanced defense gene induction. These results suggested that the difference in FCR severity between the tall and dwarf isolines is likely due to their height difference per se or to some physiological and structural consequences of reduced height. Thus, caution should be taken when considering to exploit any FCR locus located near a height gene.

Effect of heparin-superoxide dismutase on γ-radiation induced DNA damage in vitro and in vivo

The effects of heparin-superoxide dismutase (SOD) conjugate (heparin-SOD) on γ-radiation induced DNA damage in vivo and in vitro were evaluated. Plasmid pcDNA3.0 solution was mixed with heparin-SOD, SOD, and a mixture of heparin and SOD (heparin + SOD), respectively, and irradiated with (60)Co at a dosage of 120 Gy. DNA injury was analyzed using agarose gel electrophoresis. The results showed that the degree of injury of pcDNA3.0 mixed with heparin-SOD, SOD, or heparin + SOD was less than that of untreated pcDNA3.0, and among them the degree of injury of pcDNA3.0 mixed with heparin-SOD was the least. It also showed that the protective effect increased with an increase of heparin-SOD concentration. The effects of SOD and heparin-SOD on the DNA damage and tumor inhibition rate of (60)Co γ-radiation exposure on tumor-bearing mice were also studied. Agarose gel electrophoresis showed that, when different SOD samples were administered before irradiation, the thymus DNA injuries of heparin-SOD, SOD, or heparin + SOD groups were more serious than that of the control group, and the DNA injuries of heparin-SOD or heparin + SOD groups were the most serious, which contradicted the above in vitro experiments. However, when heparin-SOD was administered post irradiation, it showed a repairing effect on the injured DNA.

Rehmanniae Radix provides most of the free fructose and glucose in Si-Wu-Tang decoction

Our previous study showed that free fructose is an important active constituent responsible for Si-Wu-Tang's (SWT) effect promoting hematopoiesis and immunity. However, the contribution from SWT's four ingredient drugs to the free fructose content in the SWT decoction was not clear. To answer this question, in this study, the fructose, glucose and sucrose content in the SWT decoction, in the decoctions of each single ingredient drug, and in the decoctions of the four formulae lacking each single ingredient drug were determined by HPLC-ELSD. The results showed that the fructose and glucose content in the decoction of single Rehmanniae Radix were almost the same as those in the SWT decoction. In the single Rehmanniae Radix decoction concentrations were: 4.25 ± 0.53 mg/mL for fructose, and 3.43 ± 0.60 mg/mL for glucose; in the SWT decoction concentrations were: 4.10 ± 0.43 mg/mL for fructose, and 3.42 ± 0.32 mg/mL for glucose, while the content of fructose and glucose in the decoctions of single Angelica Radix, single Paeoniae Radix, single Chuanxiong Rhizoma and the formula lacking Rehmanniae Radix were either very small or undetectable. On the other hand, the fructose and glucose content in the decoctions of the formulae lacking Angelica Radix, lacking Paeoniae Radix and lacking Chuanxiong Rhizoma also were approximately the same as those in the SWT decoction. This indicated that Rehmanniae Radix provides most of the free fructose and glucose in the SWT decoction, and therefore plays an important role in SWT's effect promoting hematopoiesis and immunity. As for sucrose in the SWT decoction, Angelica Radix was shown to be a major donor.

On the chemo-mechanical polishing for nano-scale surface finish of brittle wafers

Chemo-mechanical polishing (CMP) has been a common method to produce nano-scale surface finish of brittle wafers. This paper provides a relatively comprehensive review on the CMP of silicon, silicon carbide and sapphire including both patents and papers. The discussion includes the limitations and further research directions of the CMP technology, the material removal mechanisms, and the control and optimization of the CMP for brittle wafers. The paper concluded that the usage of mix- or coated- abrasives may improve the CMP in terms of less subsurface damage and higher material removal rate.

Serum fructose concentration in rats after single dose oral administration of Si-Wu-Tang

Our previous study showed that fructose is an important active constituent that is responsible for Si-Wu-Tang's (SWT) effects promoting hematopoiesis and immunity. In order to provide primary data for analysis of the mechanism of fructose's bioactivity, the concentration of serum fructose in rats after a single oral administration dose of Si-Wu-Tang was determined. The concentration of serum fructose in fasting rats was 0.34 ± 0.24 mg/dL. After oral administration of 7.2 mL per kg body weight of SWT extract (1 mL extract corresponds to 1 g SWT dried herbs), serum fructose levels reached a peak concentration of 1.03 ± 0.25 mg/dL within 60 min, and then declined to the baseline level within 180 min, a pattern which is similar to the one reported for oral administration of pure fructose. The peak concentration was only 2-3 times higher than the baseline serum fructose concentration. These results showed that the increase of blood fructose concentration after oral administration of SWT is small and transient, which is very probably due to the quick metabolism of fructose by the liver. We suggest, for future research, it is necessary to consider the probability that fructose's bioactivity on hematopoiesis and immunity is not exerted by fructose in its original form, but after it is metabolized by the liver.

Electrical properties of individual ZnO nanowires

The electrical properties of individual ZnO nanowires were investigated for two methods of fabricating nanowire-electrode junctions. The number of carriers in the nanowires was increased by electrostatically doping them by applying a gate voltage. The nanowires were chemically doped by introducing impurities during growth. The Ga-doped nanowires had a linear current-voltage relationship over a wide voltage region. The nanowire-electrode junctions were formed either by using lithography to form electrodes on the nanowire or by using an AFM probe to move a nanowire onto prepared electrodes. With both methods, electrodes made of Ga-doped ZnO were found to make better electrical contact with the nanowire than those made of Ti/Au.

Laminin acts via focal adhesion kinase/phosphatidylinositol-3' kinase/protein kinase B to down-regulate beta1-adrenergic receptor signalling in cat atrial myocytes

We previously reported that short-term (2 h) plating of cat atrial myocytes on the extracellular matrix protein, laminin (LMN) decreases adenylate cyclase activity and beta(1)-adrenergic receptor (beta(1)-AR) stimulation of L-type Ca(2+) current (I(Ca,L)). The present study sought to determine whether LMN-mediated down-regulation of beta(1) signalling is due to down-regulation of adenylate cyclase and to gain insight into the signalling mechanisms responsible. beta(1)-AR stimulation was achieved by 0.01 microm isoproterenol (isoprenaline) plus 0.1 microm ICI 118551, a selective beta(2)-AR antagonist. Atrial myocytes were plated for at least 2 h on uncoated cover-slips (-LMN) or cover-slips coated with LMN (+LMN). As previously reported, beta(1)-AR stimulation of I(Ca,L) was significantly smaller in +LMN compared to -LMN atrial myocytes. In -LMN myocytes, 10 microm LY294002 (LY), a specific inhibitor of PI-(3)K, had no effect on beta(1)-AR stimulation of I(Ca,L). In +LMN myocytes, however, LY significantly increased beta(1)-AR stimulation of I(Ca,L). Western blots revealed that compared with -LMN myocytes, +LMN myocytes showed a significant increase in Akt phosphorylation at Ser-473, which was prevented by LY. In another approach, +LMN myocytes were infected (multiplicity of infection (MOI), 100; 24 h) with replication-defective adenoviruses (Adv) expressing dominant-negative inhibitors of focal adhesion kinase (FAK) (Adv-FRNK or Adv-Y397F-FAK) or Akt (Adv-dnAkt). Compared with control cells infected with Adv-beta-galactosidase, cells infected with Adv-FRNK, Adv-Y397F-FAK or Adv-dnAkt each exhibited a significantly greater beta(1)-AR stimulation of I(Ca,L). In -LMN myocytes LY had no effect on forskolin (FSK)-stimulated I(Ca,L). However, in +LMN myocytes LY significantly increased FSK-stimulated I(Ca,L). Similar results were obtained in +LMN atrial myocytes infected with Adv-FRNK. We conclude that LMN binding to beta(1)-integrin receptors acts via FAK/PI-(3)K/Akt to inhibit adenylate cyclase activity and thereby down-regulates beta(1)-AR-mediated stimulation of I(Ca,L). These findings provide new insight into the cellular mechanisms by which the extracellular matrix can modulate atrial beta-AR signalling.

Ginsenoside Re suppresses electromechanical alternans in cat and human cardiomyocytes

Ginseng botanicals are increasingly used as complementary or alternative medicines for a variety of cardiovascular diseases, yet little is known about their cellular actions in cardiac muscle. Electromechanical alternans (EMA) is a proarrhythmic cardiac abnormality that results from disturbances of intracellular Ca(2+) homeostasis. This study sought to determine whether a purified ginsenoside extract of ginseng, Re, exerts effects to suppress EMA and to gain insight into its mechanism of action. Alternans was induced by electrically pacing cardiomyocytes at room temperature. Re (> or = 10 nM) reversibly suppressed EMA recorded from cat ventricular and atrial myocytes and Langendorff-perfused cat hearts. In cat ventricular myocytes, Re reversibly suppressed intracellular Ca(2+) concentration ([Ca(2+)](i)) transient alternans. Re exerted no significant effects on baseline action potential configuration or sarcolemmal L-type Ca(2+) current (I(Ca,L)), Na(+) current, or total K(+) conductance. In human atrial myocytes, Re suppressed mechanical alternans and exerted no effect on I(Ca,L). In cat ventricular myocytes, Re increased [Ca(2+)](i) transient amplitude and decreased sarcoplasmic reticulum (SR) Ca(2+) content, resulting in an increase in fractional SR Ca(2+) release. In SR microsomes isolated from cat ventricles, Re had no effect on SR Ca(2+) uptake. Re increased the open probability of ryanodine receptors (RyRs), i.e., SR Ca(2+)-release channels, isolated from cat ventricles and incorporated into planar lipid bilayers. We concluded that ginsenoside Re suppresses EMA in cat atrial and ventricular myocytes, cat ventricular muscle, and human atrial myocytes. The effects of Re are not mediated via actions on sarcolemmal ion channels or action potential configuration. Re acts via a subcellular mechanism to enhance the opening of RyRs and thereby overcome the impaired SR Ca(2+) release underlying EMA.

Proteomic analysis of human bone marrow mesenchymal stem cells transduced with human telomerase reverse transcriptase gene during proliferation

OBJECTIVES

Previous studies have reported immortalization and tumorigenicity of human mesenchymal stem cells (hMSCs) transduced with exogenous human telomerase reverse transcriptase (hTERT). We also have established a line of hMSCs transduced with hTERT (hTERT-hMSCs) and we have cultured these cells for 290 population doublings (PDs) during which they demonstrated a large proliferation potential but with no tumorigenicity. The aim of this study was to investigate the protein expression profile of hTERT-hMSCs with two-dimensional gel electrophoresis and peptide mass fingerprinting by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, to be able to analyse the effects of exogenous hTERT on protein expression in hMSCs.

MATERIALS AND METHODS

We generated proteome maps of primary hMSCs and hTERT-hMSCs at PD 95 and PD 275.

RESULTS

A total of 1543 +/- 145 protein spots in gels of primary MSCs at PD 12, 1611 +/- 186 protein spots in gels of hTERT-hMSCs at PD 95 and 1451 +/- 126 protein spots in gels of hTERT-hMSCs at 275 PD were detected. One hundred of these were successfully identified, including 20 which were differentially expressed.

CONCLUSIONS

The results suggest that sustaining levels of prohibitin and p53 expression along with differential expression of proteins in hTERT-hMSCs provide an insight into lack of transforming activity of hTERT-hMSCs during cell proliferation.

Mass production of ZnO nanotetrapods by a flowing gas phase reaction method

We have developed a flowing gas phase reaction method for synthesizing ZnO nanotetrapods. The synthesis was carried out in a tube furnace under air pressure using air and nitrogen as reactive and carrying gases. The zinc precursor was provided by carbothermal reduction of ZnO powder. The source material transformation efficiency is higher than 90%. ZnO nanotetrapods were nucleated and grown in the gas phase via a vapor-solid mechanism. The reaction occurred at a temperature controlled to 1050-1200 °C and gas flow rate controlled to 0.7-2 L/min. The high flow rate suppressed the diffusion of growth precursors and productions towards the tube wall, and localized them into a gas phase pipe. The harvested ZnO nanotetrapods were carried by the flowing gas and collected outside of the furnace. The sizes of the nanotetrapods range from several hundred nanometers to more than 10 µm with leg diameters of 30-200 nm. The flowing gas phase reaction method provides a relatively uniformity environment for nanotetrapod growth and simplifies the product collection procedure compared with other techniques. This technique is simple and inexpensive, which is promising for realizing continuous mass production of ZnO nanotetrapods on a factory scale.

Biological effects of protons targeted to different ranges in Arabidopsis seeds

PURPOSE

To investigate the biological effects of radiation damage induced at different depths of a plant seed and to investigate the difference in radiation response between dry seeds and water-imbibed seeds to the same type of radiation.

MATERIALS AND METHODS

Arabidopsis seeds of the wild-type Columbia ecotype were used in our experiments. Dry or water-imbibed Arabidopsis seeds were irradiated with 1.1 MeV, 2.6 MeV or 6.5 MeV protons (H+). For comparison, 30 keV nitrogen ions (N+) were also used to irradiate dry Arabidopsis seeds. The germination and survival rates of the seeds were measured after each irradiation.

RESULTS

After irradiation with 2.6 MeV H+ and 6.5 MeV H+, the fluence-response curves for germination and survival had distinct shoulders and then survival was reduced rapidly with increasing fluence. 2.6 MeV H+ was more effective than 6.5 MeV H+ in inhibiting germination and survival and water-imbibed seeds were more sensitive to the 6.5 MeV H+ irradiation than dry seeds. For 1.1 MeV H+ the germination and survival rates were reduced gradually and an intermediate plateau emerged for germination, which was similar to that observed for survival following 30 keV N+ irradiation. One of the key morphologic malformations, the multi-SAM (shoot apical meristem), was observed both for dry and water-imbibed seeds after all proton irradiations and for the dry seeds after 30 keV N+ irradiation.

CONCLUSIONS

Radiation-induced damage produced at different ranges in Arabidopsis seeds results in different fluence-response curves with water-imbibed seeds being more sensitive to proton irradiation than dry seeds. As well as the shoot apical meristem (SAM) being the primary target for irradiation, there exists a secondary target around the SAM that also contributes to the radiation response.

Signalling mechanisms in contraction-mediated stimulation of intracellular NO production in cat ventricular myocytes

In this study we sought to determine whether contractile activity has a role as a signalling mechanism in the activation of intracellular nitric oxide (NO(i)) production induced by electrical stimulation of cat ventricular myocytes. Field stimulation (FS) of single ventricular myocytes elicited frequency-dependent increases in NO(i) that were blocked by the calmodulin (CaM) inhibitor 10 microM W-7 and partially inhibited by the phosphatidylinositol 3'-kinase (PI-(3)K) inhibitor 10 microMm LY294002. Increasing extracellular [Ca(2+)] caused a concentration-dependent increase in FS-induced NO(i) that was partially inhibited by LY294002. The negative inotropic agents BDM (5 mm) or blebbistatin (10 microM) decreased cell shortening and NO(i) production without concomitant changes in L-type Ca(2+) current (I(Ca,L)) or [Ca(2+)](i) transients. The positive inotropic agents EMD 57033 or CGP 48506 (1 microM) increased cell shortening and NO(i) production without concomitant changes in I(Ca,L) or [Ca(2+)](i) transients. FS-induced NO(i) production was decreased in myocytes infected (100 multiplicity of viral infection (MOI); 24 h) with a replication-deficient adenovirus expressing a dominant-negative mutant of protein kinase B (Akt) compared with cells infected with a control adenovirus expressing beta-galactosidase. FS-induced NO(i) was partially inhibited by either endothelial (eNOS) or neuronal nitric oxide synthase (nNOS) inhibitors and completely blocked by simultaneous exposure to both. FS-induced [Ca(2+)](i) transients were increased by the nNOS inhibitor nNOS-I (0.24 microM), decreased by the eNOS inhibitor L-NIO (1 microM) and unchanged by exposure to both inhibitors. We conclude that in cat ventricular myocytes, FS-induced NO(i) production requires both Ca(2+)-dependent CaM signalling and Ca(2+)-independent PI-(3)K-Akt signalling activated by contractile activity. FS activates NO(i) production from both eNOS and nNOS, and each source of NO(i) exerts opposing effects on [Ca(2+)](i) transient amplitude. These findings are important for understanding the regulation of NO(i) signalling in the normal and mechanically failing heart.

Case Report: A Left Donor Lung Implanted in the Recipient’s Right Thorax for the Therapy of Pulmonary Fibrosis

A 68-year patient suffering from pulmonary fibrosis underwent single lung transplantation on April 4, 2005. Because the ipsilateral donor lung was severely damaged, we had to implant the contralateral lung--the left lung--to the right thorax, and finally this patient recovered.

Quantum Size Effect on Surface Photovoltage Spectra: Alpha-Fe2O3 Nanocrystals on the Surface of Monodispersed Silica Microsphere

A new method for the preparation of Fe(2)O(3) nanoparticle/SiO(2) microsphere composites is described, in which fine alpha-Fe(2)O(3) nanocrystals were prepared by forced hydrolysis of FeCl(3) aqueous solution. The structure and optical spectra of these alpha-Fe(2)O(3) nanocrystals have been studied. Their visible optical absorption can be enhanced by their adsorptions on the surface of SiO(2) microspheres and thereafter simple packing of these microspheres to the aggregated structures. The size-dependent photogenerated surface photovoltage spectra (SPS) of these composites were studied, and quantum confinement effects of the SPS properties were observed. The transport of photoinduced charges between nanocrystals with intrinsic electronic nature of confined states accounts for this phenomenon. These results are helpful in understanding the relationship among d-d transition and charge-transfer transition in transition metal oxides and find applications in photovoltaic devices.

Phenylephrine acts via IP3-dependent intracellular NO release to stimulate L-type Ca2+ current in cat atrial myocytes

This study determined the effects of alpha1-adrenergic receptor (alpha1-AR) stimulation by phenylephrine (PE) on L-type Ca2+ current (I(Ca,L)) in cat atrial myocytes. PE (10 microm) reversibly increased I(Ca,L) (51.3%; n = 40) and shifted peak I(Ca,L) activation voltage by -10 mV. PE-induced stimulation of I(Ca,L) was blocked by each of 1 microm prazocin, 10 microm L-NIO, 10 microm W-7, 10 microm ODQ, 2 microm H-89 or 10 microm LY294002, and was unaffected by 10 microm chelerythrine or incubating cells in pertussis toxin (PTX). PE-induced stimulation of I(Ca,L) also was inhibited by each of 10 microm ryanodine or 5 microm thapsigargin, by blocking IP3 receptors with 2 microm 2-APB or 10 microm xestospongin C or by intracellular dialysis of heparin. In field-stimulated cells, PE increased intracellular NO (NOi) production. PE-induced NOi release was inhibited by each of 1 microm prazocin, 10 microm L-NIO, 10 microm W-7, 10 microm LY294002, 2 microm H-89, 10 microm ryanodine, 5 microm thapsigargin, 2 microm 2-APB or 10 microm xestospongin C, and unchanged by PTX. PE (10 microm) increased phosphorylation of Akt, which was inhibited by LY294002. Confocal microscopy showed that PE stimulated NOi release from subsarcolemmal sites and this was prevented by 2 mm methyl-beta-cyclodextrin, an agent that disrupts caveolae formation. PE also increased local, subsarcolemmal SR Ca2+ release via IP3-dependent signalling. Electron micrographs of atrial myocytes show peripheral SR cisternae in close proximity to clusters of caveolae. We conclude that in cat atrial myocytes PE acts via alpha1-ARs coupled to PTX-insensitive G-protein to release NOi, which in turn stimulates I(Ca,L). PE-induced NOi release requires stimulation of both PI-3K/Akt and IP3-dependent Ca2+ signalling. NO stimulates I(Ca,L) via cGMP-mediated cAMP-dependent PKA signalling. IP3-dependent Ca2+ signalling may enhance local SR Ca2+ release required to activate Ca2+-dependent eNOS/NOi production from subsarcolemmal caveolae sites.

Observation by an air-shower array in Tibet of the multi-TeV cosmic-ray anisotropy due to terrestrial orbital motion around the Sun

We report on the solar diurnal variation of the galactic cosmic-ray intensity observed by the Tibet III air shower array during the period from 1999 to 2003. In the higher-energy event samples (12 and 6.2 TeV), the variations are fairly consistent with the Compton-Getting anisotropy due to the terrestrial orbital motion around the Sun, while the variation in the lower-energy event sample (4.0 TeV) is inconsistent with this anisotropy. This suggests an additional anisotropy superposed at the multi-TeV energies, e.g., the solar modulation effect. This is the highest-precision measurement of the Compton-Getting anisotropy ever made.

Electron holography study on the microstructure of magnetic tunnelling junctions

Electron holography was applied to study the microstructure evolution of magnetic tunnelling junctions (MTJs) CoFe/AlO(x)/Co annealed at different temperatures. A mean inner potential barrier was observed in the as-deposited MTJ sample, while it was changed to a potential well after a 200 degrees C or a 400 degrees C annealing. It is suggested that the oxygen atoms were redistributed during the annealing, which left metallic atoms acting as acceptors to confine the electrons, leading to the decrease of the potential of the AlO(x) barrier layer. The results suggest that the electron holography may be a useful tool for the study of the microstructure of amorphous materials.

Fine mapping of the rice thermo-sensitive genic male-sterile gene tms5

AnnongS-1, a thermo-sensitive genic male-sterile (TGMS) rice line, has a new TGMS gene. Genetic analysis indicated that the sterility of AnnongS-1 was controlled by a single resessive gene named tms5. In our previous studies based on an F(2) population from the cross between AnnongS-1 and Nanjing11, tms5 was mapped on chromosome 2. Recently, a RIL (recombinant inbred line) population from the same cross was developed and used for the fine mapping of the tms5 gene. Molecular marker techniques combined with BSA (bulked segregant analysis) were used. As a result, two AFLP markers (AF10, AF8), one RAPD marker (RA4), one STS marker (C365-1), one CAPs marker (G227-1) and four SSR markers (RM279, RM492, RM327, RM324) were found to be closely linked to tms5 gene. The DNA sequences of the RFLP marker of C365 and G227 were found in GenBank, and on the basis of these sequences, many primers were designed to amplify the two parents and their RIL population plants. Finally, the tms5 gene was mapped between STS marker C365-1 and CAPs marker G227-1 at a distance of 1.04 cM from C365-1 and 2.08 cM from G227-1.

[Application of isonucleus and isocytoplasmic lines in the study of maize CMS]

Between wild fertile type (F) and its sterile mutant (cms), if their nucleus and cytoplasm are the same, this wild fertile type (F) and its sterile mutant (cms) are called isonucleus and isocytoplasmic lines. The maize mtDNAs of isonucleus and isocytoplasmic lines (I), wild fertile type 478(F) and its sterile mutant 478-cms, were analyzed by RAPD. 94 primers were screened, 3 polymorphic products, OPZ-19(420), OPAA-15(600) and OPS-01(400), were amplified between 478(F) and 478-cms. The results showed that mtDNAs in isonucleus and isocytoplasmic lines were more homologous than that in others. There is minor mtDNA difference between the fertile type (F) and its sterile type (cms) in a pair of isonucleus and isocytoplasmic lines. The polymorphism detected in isonucleus and isocytoplasmic lines may be more closely linked with the gene of fertility. Therefore, isonucleus and isocytoplasmic line is an excellent system in the study of CMS. Sister isonucleus and isocytoplasmic lines are consisted of 2 groups of isonucleus and isocytoplasmic lines in which their nucleus are not all the same but closely related, their cytoplasm are the same. Using sister isonucleus and isocytoplasmic lines is equal to determining the change of fertility by transferring one cytoplasm into the isonucleus. Isonucleus and isocytoplasmic lines (II) are consisted of Su478(F) and Su478-cms. Isonucleus and isocytoplasmic lines (I) and (II) are sister isonucleus and isocytoplasmic lines. The polymorphic products, OPZ-19(420) and OPAA-15(600), can also be obtained in isonucleus and isocytoplasmic lines (II). The 2 polymorphic products OPZ-19(420) and OPAA-15(600) are existed in both of the isonucleus and isocytoplasmic lines. This showed that isonucleus and isocytoplasmic lines are practicable in the study of CMS, and that common polymorphism in isonucleus and isocytoplasmic lines may be related more directly to fertility.

Analysis of Human Immunodeficiency Virus Type 1 Drug Resistance in Children Receiving Nucleoside Analogue Reverse‐Transcriptase Inhibitors plus Nevirapine, Nelfinavir, or Ritonavir (Pediatric AIDS Clinical Trials Group 377)

In Pediatric AIDS Clinical Trials Group 377, antiretroviral therapy-experienced children were randomized to 4 treatment arms that included different combinations of stavudine, lamivudine (3TC), nevirapine (Nvp), nelfinavir (Nfv), and ritonavir (Rtv). Previous treatment with zidovudine (Zdv), didanosine (ddI), or zalcitabine (ddC) was acceptable. Drug resistance mutations were assessed before study treatment (baseline) and at virologic failure. Zdv, ddI, and ddC mutations were detected frequently at baseline but were not associated with virologic failure. Children with drug resistance mutations at baseline had greater reductions in virus load over time than did children who did not. Nvp and 3TC mutations were detected frequently at virologic failure, and Nvp mutations were more common among children receiving 3-drug versus 4-drug Nvp-containing regimens. Children who were maintained on their study regimen after virologic failure accumulated additional Nvp and 3TC mutations plus Rtv and Nfv mutations. However, Rtv and Nfv mutations were detected at unexpectedly low rates.

[Cloning of the sugar related biosynthesis gene cluster from Streptomyces tenebrarius H6]

Streptomyces tenebrarius H6 produces a complex of aminoglycoside antibiotics, such as apramycin, tobramycin and kanamycin B etc. To study the apramycin biosynthetic genes the genomic library from the Streptomyces tenebrarius H6 was established using E. coli/Streptomyces shuttle vector pKC505 by in vitro packing. The probability of finding a specific gene from the library composed of 3,000 colonies was over 99.9%. According to the highly conserved sequence of the genes involved in 6-deoxyhexose biosynthesis, primers were designed and 0.6 kb fragment homologous to strE gene was obtained by PCR. 30 positive clones were found from the genomic library of S. tenebrarius H6 with the 0.6 kb fragment as a probe. Overlapped regions were localized by Southern hybridization and putative sugar related biosynthetic gene cluster was mapped by restriction enzyme digestions. An ORF of dTDP-glucose-4,6-dehydratase gene consisted of 1,132 bp, designated as aprE, was obtained and submitted to GenBank under the accession number of AF306787. A DNA sequence highly homologous to strL coding dTDP-4-dehydrorhamnose reductase was found linked with aprE gene.