Structure and expression of a cysteine proteinase gene from Spodoptera litura and its response to biocontrol fungus Nomuraea rileyi

Cysteine proteinases (Cyps) play vital roles in many biological processes, including physiological and pathological reactions. In the present study, we cloned a full cDNA of SlCyp, encoding a 344-amino-acid protein from Spodoptera litura. The putative amino acid sequence shared >75% identity with Cyps from other insects. A phylogenetic analysis revealed that SlCyp is closely related to other known lepidopteran Cyps. Real-time PCR and Western blotting analyses showed that SlCyp is induced by Nomuraea rileyi infection in all the tissues tested. The strongest SlCyp mRNA and protein expression was found in haemocytes, followed by the fat bodies, of unchallenged and N. rileyi-challenged S. litura. A time-course analysis showed that SlCyp mRNA and protein expression levels were upregulated in the haemocytes and fat bodies by N. rileyi infection. Upon N. rileyi infection, the proteolytic activities of SlCyp were also significantly higher in the haemolymph than in normal or phosphate-buffered-saline-challenged controls. These results suggest that SlCyp plays an important role in the innate immunity of S. litura in response to N. rileyi. SlCyp mRNA and protein expression and activities were also elevated during sixth-instar moulting and metamorphosis. Knocking down SlCyp transcripts with double-stranded RNA interference caused prepupal, pupal, and adult phenotypic changes, and SlCyp-silenced mutant larvae displayed a significantly lower survival rate after N. rileyi infection. These facts suggest that SlCyp plays a significant role in resisting N. rileyi infection and an essential role in larval development. Our data should facilitate the development of techniques for S. litura control.

Electron density compression and oscillating effects on laser energy absorption in overdense plasma targets

An analytical model for energy absorption during the interaction of an ultrashort, ultraintense laser with an overdense plasma is proposed. Both the compression effect of the electron density profile and the oscillation of the electron plasma surface are self-consistently included, which exhibit significant influences on the laser energy absorption. Based on our model, the general scaling law of the compression effect depending on laser strength and initial density is derived, and the temporal variation of the laser absorption due to the boundary oscillating effect is presented. It is found that due to the oscillation of the electron plasma surface, the laser absorption rate will vibrate periodically at ω or 2ω frequency for the p-polarized and s-polarized laser, respectively. The effect of plasma collision on the laser absorption has also been investigated, which shows a considerable rise in absorption with increasing electron-ion collision frequency for both polarizations.

Controlling the hydrothermal growth and the properties of ZnO nanorod arrays by pre-treating the seed layer

Annealing or plasma pre-treating the ZnO seed layer influences the nucleation and hydrothermal growth of ZnO nanorods and their photoluminescence.

C-terminal in Sp1-like artificial zinc-finger proteins plays crucial roles in determining their DNA binding affinity

Background

It is well known that the C-terminal zinc-finger-3 in transcription factor Sp1 contributes more than the N-terminal zinc-finger-1 in determining Sp1’s DNA binding capacity. Sp1-like artificial poly-zinc-finger proteins (ZFPs) are powerful biotechnological tools for gene-specific recognization and manipulation. It is important to understand whether the C-terminal fingers in the Sp1-like artificial ZFPs remain crucial for their DNA binding ability. Recently, a set of p16 promoter-specific seven-ZFPs (7ZFPs) has been constructed to reactivate the expression of methylation-silenced p16. These 7ZFPs contain one N-terminal three-zinc-finger domain of Sp1 (3ZF), two Sp1-like two-zinc-finger domains derived from the Sp1 finger-2 and finger-3 (2ZF) in the middle and C-terminal regions.

Results

In the present study, sets of variants for several representative 7ZFPs with the p16-binding affinity were further constructed. This was accomplished through finger replacements and key amino acid mutations in the N-terminal fingers, C-terminal fingers, and linker peptide, respectively. Their p16-binding activity was analysed using gel mobility shift assays. Results showed that the motif replacement or a key amino acid mutation (S > R) at position +2 of the α-helix in the C-terminal 2ZF domain completely abolished their p16-binding affinity. Deletion of three amino acids in a consensus linker (TGEKP > TG) between finger-7 and the 6 × Histidine-tag in the C-terminal also dramatically abolished their binding affinity. In contrast, the replacement of the finger-3 in the N-terminal 3ZF domain did not affect their binding affinity, but decreased their binding stability.

Conclusions

Altogether, the present study show that the C-terminal region may play crucial roles in determining the DNA binding affinity of Sp1-like artificial ZFPs.

Birth oxidative stress and the development of an antioxidant system in newborn piglets

Birth oxidative stress is an oxidative response to a sudden transition process from maternal mediated respiration in uterus to autonomous pulmonary respiration outside the uterus. Meanwhile, oxidative stress has been demonstrated to be associated with various pathologies recorded in newborns. So, this research aimed to study the oxidative stress and the development of antioxidant system in newborn piglets. The measured variables include plasma lipid, protein and DNA oxidant injury, the activities of plasma antioxidant enzymes and the jejunal and ileal antioxidant gene expressions at 1, 7, 14, and 21 days after birth. Meanwhile, the nuclear factor erythroid 2-related factor 2 (Nrf2), transcription factor p65, and tumor protein 53 (p53) were determined by western blot. The results showed that newborn piglets suffered seriously from birth oxidative stress because of the naive antioxidant system. In addition, oxidant injury activated Nrf2 signaling pathway, resulting in the expression of antioxidant genes and release of antioxidant enzymes. With the development of antioxidant system, the oxidative balance gradually recovered on Day 7 after birth. In conclusion, birth caused oxidative stress and the oxidative balance gradually recovered with the development of antioxidant system.

Simultaneous generation of monoenergetic tunable protons and carbon ions from laser-driven nanofoils

Simultaneous generation of monoenergetic tunable protons and carbon ions from intense laser multi-component nanofoil interaction is demonstrated by using particle-in-cell simulations. It is shown that, the protons with the largest charge-to-mass ratio are instantly separated from other ion species and are efficiently accelerated in the "phase stable" way. The carbon ions always ride on the heavier oxygen ion front with an electron-filling gap between the protons and carbon ions. At the cost of widely spread oxygen ions, monoenergetic collimated protons and carbon ions are obtained simultaneously. By modulating the heavier ion densities in the foil, it is capable to control the final beam quality, which is well interpreted by a simple analytical model.

Coherent Josephson qubit suitable for scalable quantum integrated circuits

We demonstrate a planar, tunable superconducting qubit with energy relaxation times up to 44 μs. This is achieved by using a geometry designed to both minimize radiative loss and reduce coupling to materials-related defects. At these levels of coherence, we find a fine structure in the qubit energy lifetime as a function of frequency, indicating the presence of a sparse population of incoherent, weakly coupled two-level defects. We elucidate this defect physics by experimentally varying the geometry and by a model analysis. Our "Xmon" qubit combines facile fabrication, straightforward connectivity, fast control, and long coherence, opening a viable route to constructing a chip-based quantum computer.

[Effect of high blood levels of bile acid on respiratory functions of New Zealand rabbits]

OBJECTIVE

To compare the patterns of respiratory function variations resulting from the classical reflex of blood pressure fall and high blood levels of bile acid, so as to provide evidence for the regulation of respiratory function via bile acids.

METHODS

Seventy New Zealand male Rabbits, under general anesthesia with 20% urethane, were subjected to tracheal intubations and carotid artery cannulations via median incisions of the neck. Using a biological signal acquisition system, the changes in the breathing and blood pressure were observed in response to stimulation of the pneumogastric nerves or to ear vein injections of diluted bile acids or the water solutions of 5 dissociated bile acids.

RESULTS

Stimulation of the pneumogastric nerves and injections of diluted bile acids both lowered the blood pressure without significant differences in the total reaction time (T). However, the total respiratory reaction time of bile acids, RT(bile acids), was 9-10 times longer than the total reaction time of blood pressure T(bile acids) (P<0.001). The peak-peak values of respiratory range RR(bile acids) were higher than that RR(pneumogastric nerves)resulting from the classical reflex (P<0.001). In the interval of RT1(bile acids), the values of RR(bile acids) were significantly higher than those of RR(bile acids) in RT2(bile acids) interval. UDCA produced no significant influence on blood pressure or respiratory function (P<0.05) as the other 4 dissociated bile acid reagents did (P<0.001).

CONCLUSION

High blood levels of bile acids not only act through reflex factors but also have direct effects on respiratory function regulation. Under our experimental conditions, UDCA has no effect on blood pressure or respiratory function, but the other 4 dissociated bile acid reagents can all dose-dependently lower blood pressure and significantly affect respiratory function.