Dispersion-managed technique in temporal-frequency measurement for MoTe2-based ultrafast laser.

Ultrafast phenomena exist widely in modern scientific research. The time scale of ultrafast phenomena is mostly in the order of picosecond, femtosecond, or even attosecond. Nowadays, it is still a major challenge to study these nonrepetitive transient processes. Here, a temporal-frequency measurement based on a dispersion-managed technique has been proposed for an MoTe2-based ultrafast laser. The temporal-frequency measurement comprises a laser diode, an optical switch, a section of tunable dispersion compensation fiber, and a three-port beam splitter. Resolution of the proposed measurement can be tuned in a wide range; further, the upper and lower resolution limits are numerically simulated. The proposed measurement is expected to be applied in ultrafast pulse detection due to its application in real-time measurement of ultrafast nonrepetitive signals.

Microvesicles containing microRNA-21 induce myocardial fibrosis via AKT pathway.

OBJECTIVE: To explore the role of microvesicles (MVs) containing microRNA-21 in myocardial fibrosis and their underlying mechanism. MATERIALS AND METHODS: Myocardial ischemia rat model was first constructed for collecting myocardial tissues. Myocardial fibrosis-related indicators and microRNA-21 expression in myocardial tissues of ischemia rats were detected. After in vitro primary rat cardiomyocytes were treated with TGF-ß1, myocardial fibrosis-related indicators and microRNA-21 expression in primary rat cardiomyocytes were also detected. Furthermore, AKT (protein kinase B) pathway-related genes were detected by Western blot. Rescue experiments were performed after primary rat cardiomyocytes were transfected with a microRNA-21 inhibitor. RESULTS: MVs containing microRNA-21 were overexpressed during the process of myocardial fibrosis. AKT pathway was remarkably activated after TGF-ß1 treatment in cardiomyocytes. Meanwhile, myocardial fibrosis was significantly alleviated after microRNA-21 expression was inhibited. CONCLUSIONS: Overexpressed MVs containing microRNA-21 promoted myocardial fibrosis via AKT pathway.

Analysis on additive effects and additive-by-additive epistatic effects of QTLs for yield traits in a recombinant inbred line population of rice.

A linkage map consisting of 158 DNA markers were constructed by using a recombinant inbred line (RIL) population derived from the indica-indica rice cross Zhenshan 97B x Milyang 46. Quantitative trait loci (QTLs) conditioning grain yield and five yield component traits were determined at the one-locus and two-locus levels, and genotype-by-environment (GE) interactions were analyzed. Thirty-one QTLs were detected to have significant additive effects for yield traits, of which 12 also exhibited significant epistatic effects. Sixteen significant additive-by-additive (AA) interactions were detected, of which nine occurred between QTLs with own additive effects (M(ep)QTLs), four occurred between QTLs showing epistatic effects only (epQTLs), and three occurred between M(ep)QTLs and epQTLs. Significant GE interactions were found for six QTLs with additive effects and one AA interaction. Generally, the contributions to the phenotypic variation were higher due to QTL main effects than to epistatic effects. The detection of additive effects and AA effects of a QTL interfered with each other, indicating that the detection of QTLs with main effects, as well as the magnitude and directions of the additive effects, might vary depending on their interactions with other loci.

[Genetic analysis of cry1Ab gene of Bt rice].

Improved histochemical staining for GUS activity, PCR and Western blotting were used to analyse the progeny population of Bt rice crossed with conventional rice varieties. A total of 392 plants expressing Bt toxin protein were found in 394 GUS positive plants. The result demonstrated that cry1Ab gene closely inherited and expressed with reporter gene gus. GUS assays indicated that cry1Ab gene of Bt rice inherits as a single dorminant gene. Southern hybridization confirmed cry1Ab gene can inherit stabily in the progenies of Bt rice. Mendelian segregation of reporter gene gus was also observed in F2, BC1 and BC1F2 progenies, which indicated that cry1Ab gene inherits as a single dorminant gene in the progenies of Bt rice crossed with conventional rice varieties.

[Comparison of the detection of QTL for yield traits in different generations of a rice cross using two mapping approaches].

In the F2 and recombinant inbred populations of Zhenshan 97B/Milyang 46, RFLP linkage maps were constructed to detect QTL for yield and its component traits. Results indicated that QTL having substantial additive effects were generally detected in both F2 and recombinant inbred populations. In addition, the trait performances were measured either based on a single plant or on replicated trials in the recombinant inbred population hardly affected the detection of QTL of higher effects.

Field evaluation of resistance of transgenic rice containing a synthetic cry1Ab gene from Bacillus thuringiensis Berliner to two stem borers.

Two transgenic rice (Oryza sativa L.) lines, KMD1 and KMD2 at the R4 generation, transformed with a synthetic cry1Ab gene from Bacillus thuringiensis Berliner, were first evaluated for stem borer resistance in the field during the rice growing season of 1998 in two areas of Zhejiang Province, China. Both KMD1 and KMD2 were highly resistant to the stem borers Chilo suppressalis (Walker) and Scirpophaga incertulas (Walker), and were completely undamaged during the whole rice growing season. In contrast, damage to the plants of the untransformed parental control (Xiushui 11) was in the form of deadhearts or whiteheads. Under natural infestation by the C. suppressalis, the damage to control plants reached a peak of 88.7% of plants and 20.1% of tillers encountered with deadhearts. Under artificial and natural infestation of neonate striped stem borers at the vegetative stage and booting stage, 100% of plants and 25.6% of tillers, 78.9% of plants and 15.6% of productive tillers among artificially infested control plants were observed with the symptom of deadhearts and whiteheads, respectively. Damage to the control plants from artificial infestation by the S. incertulas reached a peak of 97.0% of plants and 22.9% of tillers damaged. The field research indicated that both KMD1 and KMD2 show great potential for protecting rice from attack by these two stem borers.

[Mapping genes for rice CMS-WA fertility restoration].

In a population consisting of 227 test-crosses of Zhenshan 97A x (Zhenshan 97B x Milyang 46) F6, a linkage map of 115 RFLP markers was constructed and employed to detect QTL for rice CMS-WA (wild abortive cytoplasmic male sterility) fertility restoration. One QTL having major effect, qRf-10, and 3 QTL having minor effects, qRf-1, qRf-7 and qRf-11, were detected. The four genes mainly acted additively with each other, but epistasis was also evident. Two minor QTL, qRf-1 and qRf-11, were significantly interacted with the major gene qRf-10. It was also found that interaction effects among minor QTL varied greatly depending on whether qRf-10 was present. Two other QTL, qSF-1 and qSF-7, were detected, which did not display any effects on fertility restoration. Instead, they showed effects for increasing SF when qRf-10 was present.