Sequencing-based gene network analysis provides a core set of gene resource for understanding thermal adaptation in Zhikong scallop Chlamys farreri

Marine organisms are commonly exposed to variable environmental conditions, and many of them are under threat from increased sea temperatures caused by global climate change. Generating transcriptomic resources under different stress conditions are crucial for understanding molecular mechanisms underlying thermal adaptation. In this study, we conducted transcriptome-wide gene expression profiling of the scallop Chlamys farreri challenged by acute and chronic heat stress. Of the 13 953 unique tags, more than 850 were significantly differentially expressed at each time point after acute heat stress, which was more than the number of tags differentially expressed (320-350) under chronic heat stress. To obtain a systemic view of gene expression alterations during thermal stress, a weighted gene coexpression network was constructed. Six modules were identified as acute heat stress-responsive modules. Among them, four modules involved in apoptosis regulation, mRNA binding, mitochondrial envelope formation and oxidation reduction were downregulated. The remaining two modules were upregulated. One was enriched with chaperone and the other with microsatellite sequences, whose coexpression may originate from a transcription factor binding site. These results indicated that C. farreri triggered several cellular processes to acclimate to elevated temperature. No modules responded to chronic heat stress, suggesting that the scallops might have acclimated to elevated temperature within 3 days. This study represents the first sequencing-based gene network analysis in a nonmodel aquatic species and provides valuable gene resources for the study of thermal adaptation, which should assist in the development of heat-tolerant scallop lines for aquaculture.

The efficacy of moxifloxacin-based triple therapy in treatment of Helicobacter pylori infection: a systematic review and meta-analysis of randomized clinical trials

Recent evidence shows that moxifloxacin could exert an antimicrobial effect against Helicobacter pylori in both in vitro and in vivo models. To systematically evaluate whether moxifloxacin-containing triple therapy could improve eradication rates and reduce side effects in first-line or second-line anti-H. pylori treatment, eligible articles were identified by searches of electronic databases. We included all randomized trials comparing moxifloxacin-based triple therapy with standard triple or quadruple therapy during H. pylori eradication treatment. Statistical analysis was performed with Review Manager 5.0.10. Subanalysis/sensitivity analysis was also performed. We identified seven randomized trials (n=1263). Pooled H. pylori eradication rates were 79.03% (95%CI: 75.73-82.07) and 68.33% (95%CI: 64.44-72.04) for patients with moxifloxacin-based triple therapy or with standard triple or quadruple therapy, respectively (intention-to-treat analysis). The odds ratio (OR) was 1.82 (95%CI: 1.17-2.81), the occurrence of total side effects was 15.23% (95%CI: 12.58-18.20) and 27.17% (95%CI: 23.64-30.92) for groups with or without moxifloxacin, and the summary OR was 0.45 (95%CI: 0.26-0.77). In subgroup analyses, we noted that the second-line eradication rate in the moxifloxacin group was significantly higher than that in the quadruple therapy group (73.33 vs 60.17%, OR: 1.78, 95%CI: 1.16-2.73, P<0.001). However, there was no difference in first-line eradication treatment. Findings from this meta-analysis suggest that moxifloxacin-based triple therapy is more effective and better tolerated than standard triple or quadruple therapy. Therefore, a moxifloxacin-based triple regimen should be used in the second-line treatment of H. pylori infection.

Dynamical system for computing the eigenvectors associated with the largest eigenvalue of a positive definite matrix

A dynamical system for computing the largest eigenpair of a given positive matrix is introduced. Certain qualitative properties of the proposed system are analyzed in detail. The authors' results suggest that the weight-bounding term in PCA algorithms for extracting the first principal component could assume a class of forms.

Dispersion of single walled carbon nanotubes in amidine solvents

The excellent electronic and material properties of single walled carbon nanotubes (SWNTs) makes this nanomaterial very attractive for incorporation into flexible and stretchable electronics. However, the widespread application of SWNTs in electronic devices is still limited. To purify, process and place SWNTs, appropriate solvents for dispersion are needed. However, a fundamental understanding of the reasons why certain solvents are capable of dispersing SWNTs is still missing. Here we report on two new potential solvents containing amidine moieties, 1,8-diazabicycloundec-7-ene (DBU) and 1,5-diazabicyclo(4.3.0)non-5-ene (DBN). Even though these solvents' molecular structures differ by only two -CH(2)- groups, we found that DBU is capable of dispersing SWNTs, while DBN is not. We carried out density functional theory (DFT) calculations to investigate the interaction between DBU and DBN, and we elucidated the reasons for the different performances of the two solvents. DBU has a preferential edge-on interaction with the SWNT, thus allowing for a higher solvent coverage than DBN. In addition, the CH(2)-SWNT interaction present for DBU substantially increases the adsorption energy compared to DBN. Our results point to the important interplay between the interaction of pi electrons, nitrogen lone pairs and the -CH(2)- groups present in aprotic solvent molecules and the delocalized pi electrons in SWNTs.

Facile Deposition Processes for Semiconducting Molecular Solids

Films of end-substituted dihexyl-α-sexithiophene and –quinquethiophene were cast from solutions in aromatic solvents onto SiO2 and polyimide dielectrics at moderately elevated temperatures and reduced pressure. X-ray diffraction showed perpendicular orientation for most samples, while electron and optical microscopy revealed considerable variations in grain sizes, spacings, and uniformity depending on deposition conditions. For favorable morphologies, thin film transistor (TFT) mobilities were as high as those typically obtained from vacuum-deposited films, in the range of 0.01-0.2 cm2/Vs, with on/off ratios >1000 in accumulation mode.

K(ATP) channels are involved in regulatory volume decrease in rat cardiac myocytes

Regulatory volume decrease (RVD) is essential for the survival of animal cells. The aim of this study was to observe the RVD process in rat ventricular myocytes, and to determine if the K(ATP) channels are involved in the RVD process in these cells. By using reverse transcriptase polymerase chain reaction and Western blot analysis, we demonstrated that there are two types of K(ATP) channels expressed in rat ventricular myocytes: Kir6.1 and Kir6.2. When rat cardiac myocytes were exposed to hypotonic solution, cell volume increased significantly within 15 min and then gradually recovered. This typical RVD process could be inhibited by a Cl(-) channel blocker (0.5 mM 9-anthracene-carboxylic acid?9-AC), a K(+) channel blocker (5.0 mM CsCl) and a K(ATP) channel blocker glibenclamide (10 microM). Electrophysiological results showed that hypotonic solution activated a whole-cell current, which had similar biophysical characteristics with K(ATP) opener (pinacidil)-induced currents. This current could be blocked by glibenclamide. Our data suggested that the RVD process in rat ventricular myocytes is dependent on the activation of K(+) channels, and that K(ATP) channels are involved in this process.

Formation of nanostructured, nanocrystalline boron nitride microparticles with diatom-derived 3-D shapes

The first use of diatom frustules as shape-dictating 3-D templates for the syntheses of nanostructured, nanocrystalline micro-particles of a non-oxide ceramic, boron nitride, is demonstrated.

Single- and multigrain nanojunctions with a self-assembled monolayer of conjugated molecules

Systematic conductivity measurements in nanoscale junctions containing a self-assembled monolayer of conjugated molecules are reported. Different conductivity mechanisms are identified depending on the granularity of the metal used as a substrate for assembling the monolayer. Unexpectedly, the energy scale controlling the dominant conductance channels is quite low in comparison with the molecular level spacing. In single-grain junctions, the dominant conductance mechanism is hopping with an energy scale of the order of 10-100 meV determined by the nature of the metal contacts. In the case of multigrain junctions, additional tunnel conductance is observed with low-energy Coulomb-blockade features.

[Studies on extensive application of bromoacetamide in various types of schistosomiasis endemic area]

AIM

To provide scientific basis for the popularization and application of molluscide bromoacetamide.

METHODS

Large scale application of bromoacetamide in twenty eight counties of four provinces was investigated and its molluscicidal effect in marshland and influence on marshland grass (Cyperus) and fishes were observed.

RESULTS

High molluscicidal effect of bromoacetamide was found against both snails and snail eggs in various environments. According to the results observed in different fields, the applicable dosage of bromoacetamide is 1.5-2 g/m2 for spraying method, 1.5-2 g/m3 for immersing method and 1.5-2 g/m for immersing in combination with shovelling the turf along the bank. When it was applied in fish-raising ponds or rivers at an applicable dosage, no toxic effect on fishes was found. The spraying dosage of bromoacetamide did not affect the rice seedling but it did some damage to the leaf-tips of marshland grass, however, the grass did turn green and grow.

CONCLUSION

Bromoacetamide has proved to be a safe and effective mulluscicde against Oncomelania under various field conditions.

Conductance of small molecular junctions

A new method of fabricating small metal-molecule-metal junctions is developed, approaching the single-molecule limit. The conductance of different conjugated molecules in a broad temperature, source-drain, and gate voltage regime is reported. At low temperature, all investigated molecules display sharp conductance steps periodic in source-drain voltage. The position of these steps can be controlled by a gate potential. The spacing corresponds to the energy of the lowest molecular vibrations. These results show that the low-bias conductance of molecules is dominated by resonant tunneling through coupled electronic and vibration levels.

Field-effect modulation of the conductance of single molecules

Field-effect transistors based on two-component self-assembled monolayers of conjugated and insulating molecules were prepared; the conductance through them can be varied by more than three orders of magnitude by changing the applied gate bias. With very small ratios of conjugated to insulating molecules in the two-component monolayer, devices with only a few "electrically active" molecules can be achieved. At low temperatures, the peak channel conductance is quantized in units of 2e2/h (where e is the electron charge and h is Planck's constant). This behavior is indicative of transistor action in single molecules. On the basis of such single-molecule transistors, inverter circuits with gain are demonstrated.

Self-assembled monolayer organic field-effect transistors

The use of individual molecules as functional electronic devices was proposed in 1974 (ref. 1). Since then, advances in the field of nanotechnology have led to the fabrication of various molecule devices and devices based on monolayer arrays of molecules. Single molecule devices are expected to have interesting electronic properties, but devices based on an array of molecules are easier to fabricate and could potentially be more reliable. However, most of the previous work on array-based devices focused on two-terminal structures: demonstrating, for example, negative differential resistance, rectifiers, and re-configurable switching. It has also been proposed that diode switches containing only a few two-terminal molecules could be used to implement simple molecular electronic computer logic circuits. However, three-terminal devices, that is, transistors, could offer several advantages for logic operations compared to two-terminal switches, the most important of which is 'gain'-the ability to modulate the conductance. Here, we demonstrate gain for electronic transport perpendicular to a single molecular layer ( approximately 10-20 A) by using a third gate electrode. Our experiments with field-effect transistors based on self-assembled monolayers demonstrate conductance modulation of more than five orders of magnitude. In addition, inverter circuits have been prepared that show a gain as high as six. The fabrication of monolayer transistors and inverters might represent an important step towards molecular-scale electronics.