Laboratory observation of ion drift acceleration via reflection off laser-produced magnetized collisionless shocks.

Fermi acceleration is believed to be the primary mechanism to produce high-energy charged particles in the Universe, where charged particles gain energy successively from multiple reflections. Here, we present the direct laboratory experimental evidence of ion energization from single reflection off a supercritical collisionless shock, an essential component of Fermi acceleration, in a laser-produced magnetized plasma. A quasi-monoenergetic ion beam with two to four times the shock velocity was observed, which is consistent with the fast ion component observed in the Earth's bow shock.

Carriage of Clostridioides difficile in healthy infants in the community of Handan, China: A 1-year follow-up study.

Objective: Clostridioides difficile may colonize healthy infants and young children asymptomatically and for the long-term. C. difficile genotypes and the rate and determinants of colonization differ substantially and vary among countries and regions.

Intense broadband mid-infrared pulses of 280 MV/cm for supercontinuum generation in gaseous medium.

We produce extremely bright mid-infrared (mid-IR) pulses with a tunable wavelength of 7 μm to 15 μm through difference frequency generation. Optimization of beam quality and beam focusing results in an intense mid-IR field spatiotemporally confined in the lambda-cubic volume. A near planar wavefront is achieved through manipulating the wavefront curvature of the pumping pulse in the frequency downconversion process.

Molecular Characterization of Clostridium difficile Isolates from Human Subjects and the Environment.

Clostridium difficile is a spore-forming, gram-positive, anaerobic bacillus that can cause C. difficile infection (CDI). However, only a few studies on the prevalence and antibiotic resistance of C.

Frequency modulation of synchronized Ca(2+) spikes in cultured hippocampal networks through mTOR.

The atypical serine/threonine protein kinase, a mammalian target of rapamycin (mTOR), is believed to be essential to the regulation of cell growth and the functions of the central nervous system. By using calcium imaging and patch-clamping techniques to study the role of this signaling pathway in the activity of cultured hippocampal neurons, we found that rapamycin significantly reduces the spontaneous activities of network neurons as well as the efficacy of synaptic transmission through insulin-mTOR signaling pathway. Our study sheds light on understanding the role of mTOR signaling pathway in controlling the information processing of network neurons.

Sarcoplasmic reticulum Ca2+ release channel ryanodine receptor (RyR2) plays a crucial role in aconitine-induced arrhythmias.

The present study established a model of RyR(2) knockdown cardiomyocytes and elucidated the role of RyR(2) in aconitine-induced arrhythmia. Cardiomyocytes were obtained from hearts of neonatal Sprague-Dawley rats. siRNAs were used to down-regulate RyR(2) expression.

Astragaloside IV inhibits spontaneous synaptic transmission and synchronized Ca2+ oscillations on hippocampal neurons.

Aim: To investigate the changes in the spontaneous neuronal excitability induced by astragaloside IV (AGS-IV) in the cultured hippocampal network.

Methods: Hippocampal neurons in culture for 9-11 d were used for this study. The spontaneous synaptic activities of these hippocampal neurons were examined by Ca2+ imaging and whole-cell patch-clamp techniques.

Multiterawatt laser system based on optical parametric chirped pulse amplification.

A compact multiterawatt laser system based on optical parametric chirped pulse amplification is demonstrated. Chirped pulses are amplified from 20 pJ to 900 mJ by two lithium triborate optical parametric preamplifiers and a final KDP optical parametric power amplifier with a pump energy of 5 J at 532 nm from Nd:YAG-Nd:glass hybrid amplifiers. After compression, we obtained a final output of 570-mJ-155-fs pulses with a peak power of 3.

Laser self-focusing in the presence of quasistatic axial direct current.

We try to understand the presence of a quasistatic magnetic field on the basis of the stability of the laser-plasma system. A general theoretical model of laser self-focusing in the absence of a quasistatic magnetic field (QMF) is extended to discuss self-focusing in the presence of a QMF. Various transverse intensity profiles under different axial collective electronic speeds V(z) are calculated.