Physiological and transcriptomic analysis dissects the molecular mechanism governing meat quality during postmortem aging in Hu sheep ().

Introduction: Hu sheep, known for its high quality and productivity, lack fundamental scientific research in China.

Methods: This study focused on the effects of 24 h postmortem aging on the meat physiological and transcriptomic alteration in Hu sheep.

Results: The results showed that the 24 h aging process exerts a substantial influence on the mutton color, texture, and water content as compared to untreated group.

Hysteresis of a passively mode-locked fiber laser: effects from cavity dispersion.

Hysteresis is a common phenomenon in passively mode-locked lasers and refers to the effect where the thresholds marking transitions between different pulsation states are not the same for an increasing or decreasing pump power. Despite wide presence in experimental observations, the general dynamics of hysteresis remains elusive, largely due to the challenge to acquire the full hysteresis dynamics of a given mode-locked laser. In this Letter, we overcome this technical bottleneck by fully characterizing an exemplar figure-9 fiber laser cavity, which exhibits well-defined mode-locking patterns in its parameter space or "primitive cell.

RNA-sequencing transcriptome analysis of Avicennia marina (Forsk.) Vierh. leaf epidermis defines tissue-specific transcriptional response to salinity treatment.

Avicennia marina (Forsk.) Vierh. is a typical mangrove plant.

Adaptation of gut microbiome and host metabolic systems to lignocellulosic degradation in bamboo rats.

Bamboo rats (Rhizomys pruinosus) are among the few mammals that lives on a bamboo-based diet which is mainly composed of lignocellulose. However, the mechanisms of adaptation of their gut microbiome and metabolic systems in the degradation of lignocellulose are largely unknown. Here, we conducted a multi-omics analysis on bamboo rats to investigate the interaction between their gut microbiomes and metabolic systems in the pre- and post-weaning periods, and observed significant relationships between dietary types, gut microbiome, serum metabolome and host gene expression.

Probing the mode-locking pattern in the parameter space of a Figure-9 laser.

Due to the many available cavity configurations, a generalized approach for identifying the optimal operating state of a Figure-9 mode-locked laser has proved a challenge. In this Letter, we probe the output pulsation states of an exemplar Figure-9 laser by meticulously scanning its parameter space. Regions corresponding to mode-locked operations are identified periodically in the map of the output states.

High energy (>40 nJ), sub-100 fs, 950 nm laser for two-photon microscopy.

Compact and high-energy femtosecond fiber lasers operating around 900-950 nm are desirable for multiphoton microscopy. Here, we demonstrate a >40 nJ, sub-100 fs, wavelength-tunable ultrafast laser system based on chirped pulse amplification (CPA) in thulium-doped fiber and second-harmonic generation (SHG) technology. Through effective control of the nonlinear effect in the CPA process, we have obtained 92-fs pulses at 1903 nm with an average power of 0.

Assessing Seasonal Nitrate Contamination by Nitrate Dual Isotopes in a Monsoon-Controlled Bay with Intensive Human Activities in South China.

Nitrate (NO) dual isotope analysis was performed in Zhanjiang Bay, which is a closed bay with intensive human activities in South China, to investigate seasonal changes in the main NO sources and their biogeochemical processes in the monsoon-controlled climate. The relatively low N/P ratios in Zhanjiang Bay suggests that nitrogen (N) is a limiting nutrient, which indicates that the increase of N is favorable for phytoplankton proliferation. However, a sufficient amount of ammonium was found in our study area owing to intensive human activities, which can support biological processes.

Spatial and Seasonal Variations of Sedimentary Organic Matter in a Subtropical Bay: Implication for Human Interventions.

Elemental (total organic carbon (TOC) and total nitrogen (TN)) and stable carbon and nitrogen isotope compositions (δC and δN, respectively) in the surface sediment of Zhanjiang Bay (ZJB) in spring and summer were measured to study the spatial and seasonal changes of organic matter (OM) and assess the human-induced and environment-induced changes in the area. The OM in the surface sediment of ZJB was a mixture of terrestrial and marine sources, and was dominated by marine OM (54.9% ± 15.

Slowing down photocarrier relaxation in Dirac semimetal CdAs via Mn doping.

In this Letter, we successfully introduce a long-lived non-radiative photocarrier decay component in a Dirac semimetal CdAs thin film via Mn doping. The long-lived decay component is found to vary between 200 ps and 2.8 ns with different Mn concentrations and probing wavelengths.

Nanotube mode-locked, wavelength and pulsewidth tunable thulium fiber laser.

Mode-locked oscillators with highly tunable output characteristics are desirable for a range of applications. Here, with a custom-made tunable filter, we demonstrate a carbon nanotube (CNT) mode-locked thulium fiber laser with widely tunable wavelength, spectral bandwidth, and pulse duration. The demonstrated laser's wavelength tuning range reached 300 nm (from 1733 nm to 2033 nm), which is the widest-ever that was reported for rare-earth ion doped fiber oscillators in the near-infrared.

Dirac semimetal saturable absorber with actively tunable modulation depth.

In this Letter, we demonstrate an electrically contacted saturable absorber (SA) device based on topological Dirac semimetal CdAs. With a current-induced temperature change in the range of 297-336 K, the modulation depth of the device is found to be significantly altered from 33% to 76% (under the irradiation of a 1560 nm femtosecond laser). The broad tuning of the modulation depth is attributed to the strong temperature dependence of the carrier concentration close to room temperature.

20 GHz actively mode-locked thulium fiber laser.

A high repetition-rate actively mode-locked thulium fiber laser is demonstrated where an electro-optic lithium niobate phase modulator is used to synchronize the longitudinal modes in the cavity. The repetition rate of the actively mode-locked laser is tunable from 14.6 MHz to 19 GHz, where the 19 GHz pulses exhibit a super-mode suppression ratio of 46 dB.

Three-dimensional Dirac semimetal thin-film absorber for broadband pulse generation in the near-infrared.

In this Letter, the transient nonlinear absorption of three-dimensional (3D) topological Dirac semimetal CdAs thin film was characterized in the near-infrared band. By performing broadband pump-probe measurements, we experimentally proved that molecular beam epitaxy (MBE) grown CdAs exhibits strong and tunable saturable absorption effects across 1-2 μm. By further inserting the CdAs film into the cavities of Tm- and Er-doped fiber lasers, we obtained stable mode-locked operations at 1.

Carbon Nanotube Mode-Locked Thulium Fiber Laser With 200 nm Tuning Range.

We demonstrated a mode-locked thulium/holmium (Tm/Ho) fiber laser continuously tunable across 200 nm (from 1860 nm to 2060 nm), which to the best of our knowledge represents the widest tuning range ever achieved for a passively mode-locked fiber laser oscillator. The combined use of a broadband carbon nanotube (CNT) saturable absorber and a diffraction grating mirror ensures ultra-broad tuning range, superb stability and repeatability, and makes the demonstrated laser a highly practical source for spectroscopy, imaging and optical communications. The laser emits <5 ps pulses with an optical spectral bandwidth of ∼3 nm across the full tuning range.

A robust and tuneable mid-infrared optical switch enabled by bulk Dirac fermions.

Pulsed lasers operating in the mid-infrared (3-20 μm) are important for a wide range of applications in sensing, spectroscopy, imaging and communications. Despite recent advances with mid-infrared gain platforms, the lack of a capable pulse generation mechanism remains a significant technological challenge. Here we show that bulk Dirac fermions in molecular beam epitaxy grown crystalline CdAs, a three-dimensional topological Dirac semimetal, constitutes an exceptional ultrafast optical switching mechanism for the mid-infrared.

Ultrafast nonlinear photoresponse of single-wall carbon nanotubes: a broadband degenerate investigation.

Understanding of the fundamental photoresponse of carbon nanotubes has broad implications for various photonic and optoelectronic devices. Here, Z-scan and pump-probe spectroscopy performed across 600-2400 nm were combined to give a broadband 'degenerate' mapping of the nonlinear absorption properties of single-wall carbon nanotubes (SWNTs). In contrast to the views obtained from non-degenerate techniques, sizable saturable absorption is observed from the visible to the near-infrared range, including the spectral regions between semiconducting excitonic peaks and metallic tube transitions.