Neuronal innervation regulates the secretion of neurotrophic myokines and exosomes from skeletal muscle.

Myokines and exosomes, originating from skeletal muscle, are shown to play a significant role in maintaining brain homeostasis. While exercise has been reported to promote muscle secretion, little is known about the effects of neuronal innervation and activity on the yield and molecular composition of biologically active molecules from muscle. As neuromuscular diseases and disabilities associated with denervation impact muscle metabolism, we hypothesize that neuronal innervation and firing may play a pivotal role in regulating secretion activities of skeletal muscles. We examined this hypothesis using an engineered neuromuscular tissue model consisting of skeletal muscles innervated by motor neurons. The innervated muscles displayed elevated expression of mRNAs encoding neurotrophic myokines, such as interleukin-6, brain-derived neurotrophic factor, and FDNC5, as well as the mRNA of peroxisome-proliferator-activated receptor γ coactivator 1α, a key regulator of muscle metabolism. Upon glutamate stimulation, the innervated muscles secreted higher levels of irisin and exosomes containing more diverse neurotrophic microRNAs than neuron-free muscles. Consequently, biological factors secreted by innervated muscles enhanced branching, axonal transport, and, ultimately, spontaneous network activities of primary hippocampal neurons in vitro. Overall, these results reveal the importance of neuronal innervation in modulating muscle-derived factors that promote neuronal function and suggest that the engineered neuromuscular tissue model holds significant promise as a platform for producing neurotrophic molecules.

Mapping of Long-Wavelength Phonon Contribution in the Thermal Transport of Alloyed Semiconductor Superlattices.

The mapping of long-wavelength phonons is important to understand and manipulate the thermal transport in multilayered structures, but it remains a long-standing challenge due to the collective behaviors of phonons. In this study, an experimental demonstration of mapping the long-wavelength phonons in an alloyed Al0.1Ga0.9As/Al0.9Ga0.1As superlattice system is reported. Multiple strategies to filter out the short- to mid-wavelength phonons are used. The phonon mean-free-path-dependent thermal transport properties directly demonstrate both the suppression effect of the ErAs nanoislands and the contribution of long-wavelength phonons. The contribution from phonons with mean free path longer than 1 µm is clearly demonstrated. A model based on the Boltzmann transport equation is proposed to calculate and describe the thermal transport properties, which depicts a clear physical picture of the transport mechanisms. This method can be extended to map different wavelength phonons and become a universal strategy to explore their thermal transport in various application scenarios.

Catalytic Asymmetric Synthesis of Chiral α,α-Dialkyl Aminonitriles via Reaction of Cyanoketimines.

Chiral aminonitriles not only are broadly useful building blocks but also increasingly appear as structural motifs in bioactive molecules and pharmaceuticals. The catalytic asymmetric synthesis of chiral aminonitriles, therefore, has been intensively investigated, as reflected in numerous reports of catalytic asymmetric Strecker reactions. Despite such great progress, the catalytic asymmetric synthesis of chiral α,α-dialkyl aminonitriles in a highly selective and efficient manner is still a formidable challenge. Here, we report a new approach for the catalytic asymmetric synthesis of chiral α,α-dialkyl aminonitriles via reaction of cyanoketimines with enals. We demonstrate that this reaction could be carried out with as low as 20 ppm catalyst loading.

From Oxygen Redox to Sulfur Redox: A Paradigm for Li-Rich Layered Cathodes.

The utilization of anionic redox chemistry provides an opportunity to further improve the energy density of Li-ion batteries, particularly for Li-rich layered oxides. However, oxygen-based hosts still suffer from unfavorable structural rearrangement, including the oxygen release and transition metal (TM)-ion migration, in association with the tenuous framework rooted in the ionicity of the TM-O bonding. An intrinsic solution, by using a sulfur-based host with strong TM-S covalency, is proposed here to buffer the lattice distortion upon the highly activating sulfur redox process, and it achieves howling success in stabilizing the host frameworks. Experimental results demonstrate the prolonged preservation of the layered sulfur lattice, especially the honeycomb superlattice, during the Li+ extraction/insertion process in contrast to the large structural degeneration in Li-rich oxides. Moreover, the Li-rich sulfide cathodes exhibited a negligible overpotential of 0.08 V and a voltage drop of 0.13 mV/cycle, while maintaining a substantial reversible capacity upon cycling. These superior electrochemical performances can be unambiguously ascribed to the much shorter trajectories of sulfur in comparison to those of oxygen revealed by molecular dynamics simulations at a large scale (∼30 nm) and a long time scale (∼300 ps) via high-dimensional neural network potentials during the delithiation process. Our findings highlight the importance of stabilizing host frameworks and establish general guidance for designing Li-rich cathodes with durable anionic redox chemistry.

Monocytes release cystatin F dimer to associate with Aß and aggravate amyloid pathology and cognitive deficits in Alzheimer's disease.

BACKGROUND: Understanding the molecular mechanisms of Alzheimer's disease (AD) has important clinical implications for guiding therapy. Impaired amyloid beta (Aß) clearance is critical in the pathogenesis of sporadic AD, and blood monocytes play an important role in Aß clearance in the periphery. However, the mechanism underlying the defective phagocytosis of Aß by monocytes in AD remains unclear. METHODS: Initially, we collected whole blood samples from sporadic AD patients and isolated the monocytes for RNA sequencing analysis. By establishing APP/PS1 transgenic model mice with monocyte-specific cystatin F overexpression, we assessed the influence of monocyte-derived cystatin F on AD development. We further used a nondenaturing gel to identify the structure of the secreted cystatin F in plasma. Flow cytometry, enzyme-linked immunosorbent assays and laser scanning confocal microscopy were used to analyse the internalization of Aß by monocytes. Pull down assays, bimolecular fluorescence complementation assays and total internal reflection fluorescence microscopy were used to determine the interactions and potential interactional amino acids between the cystatin F protein and Aß. Finally, the cystatin F protein was purified and injected via the tail vein into 5XFAD mice to assess AD pathology. RESULTS: Our results demonstrated that the expression of the cystatin F protein was specifically increased in the monocytes of AD patients. Monocyte-derived cystatin F increased Aß deposition and exacerbated cognitive deficits in APP/PS1 mice. Furthermore, secreted cystatin F in the plasma of AD patients has a dimeric structure that is closely related to clinical signs of AD. Moreover, we noted that the cystatin F dimer blocks the phagocytosis of Aß by monocytes. Mechanistically, the cystatin F dimer physically interacts with Aß to inhibit its recognition and internalization by monocytes through certain amino acid interactions between the cystatin F dimer and Aß. We found that high levels of the cystatin F dimer protein in blood contributed to amyloid pathology and cognitive deficits as a risk factor in 5XFAD mice. CONCLUSIONS: Our findings highlight that the cystatin F dimer plays a crucial role in regulating Aß metabolism via its peripheral clearance pathway, providing us with a potential biomarker for diagnosis and potential target for therapeutic intervention.

Lab-on-Device Synthesis of Hierarchical Macro/Mesoporous WO3 Semiconducting Films for High-Performance H2S Sensing.

The performance consistency of the gas sensor is strongly dependent on the interface binding between the sensitive materials and the electrodes. Traditional powder coating methods can inevitably lead to differences in terms of substrate-film interface interaction and device performance, affecting the stability and lifetime. Thus, efficient growth of sensitive materials on device substrates is crucial and essential to enhance the sensing performance, especially for stability. Herein, hierarchically ordered macro/mesoporous WO3 films are in situ synthesized on the electrode via a facile soft/hard dual-template strategy. Orderly arrayed uniform polystyrene (PS) microspheres with tailored size (ca. 1.2 µm) are used as a hard template, and surfactant Pluronic F127 as a soft template can co-assemble with tungsten precursor into ordered mesostructure in the interstitials of PS colloidal crystal induced by solvent evaporation. Benefiting from its rich porosity and high stability, the macro/mesoporous WO3-based sensor shows high sensitivity (Rair/Rgas = 307), fast response/recovery speed (5/9 s), and excellent selectivity (SH2S/Smax > 7) toward 50 ppm H2S gas (a biomarker for halitosis). Significantly, the sensors exhibit an extended service life with a negligible change in sensing performance within 60 days. This lab-on-device synthesis provides a platform method for constructing stable nanodevices with good consistency and high stability, which are highly desired for developing high-performance sensors.

Freeze Metal Halide Perovskite for Dramatic Laser Tuning: Direct Observation via In Situ Cryo-Electron Microscope.

A frozen-temperature (below -28 °C) laser tuning way is developed to optimize metal halide perovskite (MHP)'s stability and opto-electronic properties, for emitter, photovoltaic and detector applications. Here freezing can adjust the competitive laser irradiation effects between damaging and annealing/repairing. And the ligand shells on MHP surface, which are widely present for many MHP materials, can be frozen and act as transparent solid templates for MHP's re-crystallization/re-growth during the laser tuning. With model samples of different types of CsPbBr3 nanocube arrays,an attempt is made to turn the dominant exposure facet from low-energy [100] facet to high-energy [111], [-211], [113] and [210] ones respectively; selectively removing the surface impurities and defects of CsPbBr3 nanocubes to enhance the irradiation durability by 101 times; and quickly (tens of seconds) modifying a Ruddlesden-Popper (RP) boundary into another type of boundary like twinning, and so on. The laser tuning mechanism is revealed by an innovative in situ cryo-transmission electron microscope (cryo-TEM) exploration at atomic resolution.

Correlation of distribution characteristics and dynamic changes of gut microbiota with the efficacy of immunotherapy in EGFR-mutated non-small cell lung cancer.

BACKGROUND: The effects of gut microbiota and metabolites on the responses to immune checkpoint inhibitors (ICIs) in advanced epidermal growth factor receptor (EGFR) wild-type non-small cell lung cancer (NSCLC) have been studied. However, their effects on EGFR-mutated (EGFR +) NSCLC remain unknown. METHODS: We prospectively recorded the clinicopathological characteristics of patients with advanced EGFR + NSCLC and assessed potential associations between the use of antibiotics or probiotics and immunotherapy efficacy. Fecal samples were collected at baseline, early on-treatment, response and progression status and were subjected to metagenomic next-generation sequencing and ultra-high-performance liquid chromatography-mass spectrometry analyses to assess the effects of gut microbiota and metabolites on immunotherapy efficacy. RESULTS: The clinical data of 74 advanced EGFR + NSCLC patients were complete and 18 patients' fecal samples were dynamically collected. Patients that used antibiotics had shorter progression-free survival (PFS) (mPFS, 4.8 vs. 6.7 months; P = 0.037); probiotics had no impact on PFS. Two dynamic types of gut microbiota during immunotherapy were identified: one type showed the lowest relative abundance at the response time point, whereas the other type showed the highest abundance at the response time point. Metabolomics revealed significant differences in metabolites distribution between responders and non-responders. Deoxycholic acid, glycerol, and quinolinic acid were enriched in responders, whereas L-citrulline was enriched in non-responders. There was a significant correlation between gut microbiota and metabolites. CONCLUSIONS: The use of antibiotics weakens immunotherapy efficacy in patients with advanced EGFR + NSCLC. The distribution characteristics and dynamic changes of gut microbiota and metabolites may indicate the efficacy of immunotherapy in advanced EGFR + NSCLC.

Enhancing glucaric acid production from myo-inositol in Escherichia coli by eliminating cell-to-cell variation.

Glucaric acid (GA) is a value-added chemical and can be used to manufacture food additives, anticancer drugs, and polymers. The non-genetic cell-to-cell variations in GA biosynthesis are naturally inherent, indicating the presence of both high- and low-performance cells in culture. Low-performance cells can lead to nutrient waste and inefficient production. Furthermore, myo-inositol oxygenase (MIOX) is a key rate-limiting enzyme with the problem of low stability and activity in GA production. Therefore, eliminating cell-to-cell variations and increasing MIOX stability can select high-performance cells and improve GA production. In this study, an in vivo GA bioselector was constructed based on GA biosensor and tetracycline efflux pump protein TetA to continuously select GA-efficient production strains. Additionally, the upper limit of the GA biosensor was improved to 40 g/L based on ribosome-binding site optimization, achieving efficient enrichment of GA high-performance cells. A small ubiquitin-like modifier (SUMO) enhanced MIOX stability and activity. Overall, we used the GA bioselector and SUMO-MIOX fusion in fed-batch GA production and achieved a 5.52-g/L titer in Escherichia coli, which was 17-fold higher than that of the original strain.IMPORTANCEGlucaric acid is a non-toxic valuable product that was mainly synthesized by chemical methods. Due to the problems of non-selectivity, inefficiency, and environmental pollution, GA biosynthesis has attracted significant attention. The non-genetic cell-to-cell variations and MIOX stability were both critical factors for GA production. In addition, the high detection limit of the GA biosensor was a key condition for performing high-throughput screening of GA-efficient production strains. To increase GA titer, this work eliminated the cell-to-cell variations by GA bioselector constructed based on GA biosensor and TetA, and improved the stability and activity of MIOX in the GA biosynthetic pathway through fusing the SUMO to MIOX. Finally, these approaches improved the GA production by 17-fold to 5.52 g/L at 65 h. This study represents a significant step toward the industrial application of GA biosynthetic pathways in E. coli.

Effects of organic fertilizers on plant growth and the rhizosphere microbiome.

Application of organic fertilizers is an important strategy for sustainable agriculture. The biological source of organic fertilizers determines their specific functional characteristics, but few studies have systematically examined these functions or assessed their health risk to soil ecology. To fill this gap, we analyzed 16S rRNA gene amplicon sequencing data from 637 soil samples amended with plant- and animal-derived organic fertilizers (hereafter plant fertilizers and animal fertilizers). Results showed that animal fertilizers increased the diversity of soil microbiome, while plant fertilizers maintained the stability of soil microbial community. Microcosm experiments verified that plant fertilizers were beneficial to plant root development and increased carbon cycle pathways, while animal fertilizers enriched nitrogen cycle pathways. Compared with animal fertilizers, plant fertilizers harbored a lower abundance of risk factors such as antibiotic resistance genes and viruses. Consequently, plant fertilizers might be more suitable for long-term application in agriculture. This work provides a guide for organic fertilizer selection from the perspective of soil microecology and promotes sustainable development of organic agriculture.IMPORTANCEThis study provides valuable guidance for use of organic fertilizers in agricultural production from the perspective of the microbiome and ecological risk.

Timing patterns of initial respiratory syncytial virus infection and factors influencing disease severity in hospitalized infants with different health status.

This study aimed to determine the timing patterns of the initial respiratory syncytial virus (RSV) infection and to identify the factors influencing disease severity in infants of varying health status. A retrospective study was conducted at the Affiliated Children's Hospital of Chongqing Medical University from 2012 to 2022. The timing of the first RSV infection was estimated in infants with differing health status using correlation analysis, considering their birth time. Logistic regression was utilized to identify factors influencing severe RSV infection in these infants. RSV detection primarily occurred in the winter and spring. Epidemic season and peak timing of RSV were not significantly affected by health status or the COVID-19 pandemic. A strong positive correlation was observed between the age at RSV infection and the interval from birth to the RSV peak season. Infants born during the RSV epidemic season exhibited a higher likelihood of infection within the first 2 months postbirth. In contrast, those born outside the RSV epidemic season were more susceptible to infection during the subsequent peak. Notably, infants with pre-existing health conditions contracted RSV at an earlier age compared to their healthy counterparts. Among healthy infants, severe RSV infection was associated with sex, age, and timing of infection. For infants with underlying conditions, severe RSV infection was primarily related to age and timing of infection. The initial timing of RSV infection in infants varied depending on their health status. Young age and infection timing during the RSV epidemic season were significant risk factors for severe RSV infection. These findings provide a theoretical basis for optimizing immunization strategies for infants with diverse health conditions.

Nonlinear dynamics of an interband cascade laser with optical injection.

This work reports the nonlinear dynamics of a mid-infrared interband cascade laser (ICL) subject to optical injection. It is shown that the stable locking regime is asymmetric and broadens with increasing injection strength. Outside the locking regime, the ICL mostly produces period-one oscillations. However, three categories of periodic pulse oscillations are observed in the vicinity of the Hopf bifurcation and the saddle-node bifurcation. In particular, it is found that the ICL generates broadband chaos at a near-threshold pump current, and the chaos bandwidth is over 300 MHz.

General error analysis of matrix-operation-mode decomposition technique in few-mode fiber laser.

The mode decomposition based on matrix operation (MDMO) is one of the fastest mode decomposition (MD) techniques, which is important to the few-mode fiber laser characterization and its applications. In this paper, the general error of the MDMO technique was analyzed, where different influencing factors, such as position deviation of the optical imaging system, coordinate deviation of the image acquisition system, aberrations, and mode distortion were considered. It is found that the MDMO technique based on far-field intensity distribution is less affected by optical imaging system position deviation, coordinate deviation of the image acquisition system, and mode distortion than those based on direct near-field decomposition. But far-field decomposition is more affected by aberration than those based on near-field decomposition. In particular, the numerical results show that the deviation of the coordinate axis direction is an important factor limiting the accuracy of MD. In addition, replacing the ideal eigenmode basis with a distorted eigenmode basis can effectively suppress the decrease in mode decomposition accuracy caused by fiber bending. Moreover, based on detailed numerical analysis results, fitting formulas for estimating the accuracy of the MDMO technique with imperfections are also provided, which provides a comprehensive method for evaluating the accuracy of the MDMO technique in practical engineering operations.

Evaluation of the impact of weak end feedback on the SBS threshold in high-power narrow-linewidth fiber amplifiers.

In this work, we quantitatively investigate the SBS threshold in high-power narrow-linewidth fiber amplifiers seeded with phase-modulated single-frequency lasers in presence of weak end feedback. The impacts of the end feedback and spectral linewidths on the SBS threshold are demonstrated in detail through comparative experiments and numerical simulations, respectively. In the experiment, we have pointed out a practical method to estimate the end reflectivity in high-power fiber amplifiers. Based on this estimation, the SBS threshold characters of the high-power narrow-linewidth fiber amplifiers with different end reflectivity and seed linewidths are investigated. By reducing the end reflectivity, a 2.85 times SBS threshold enhancement has been achieved at the most susceptible linewidth (16.8 GHz). Furthermore, we propose a spectral evolution model to investigate the SBS threshold in high-power narrow-linewidth fiber amplifiers, which is even capable for calculating SBS thresholds of the systems with tens of GHz linewidth while weak end reflection is considered. The simulation results demonstrate that end reflection will obviously affect the SBS threshold when the linewidth of the seed laser is broadened beyond 5 GHz, especially for the spectral linewidth of seed lasers nearing the Brillouin frequency shift. Besides, when the end reflectivity is set to be stronger than -65 dB, the SBS threshold performs a tendency to decline and then rise with the growth of seed linewidth. The experiment and simulation results provide a new optimization sight for the SBS effect suppression in high-power narrow-linewidth fiber amplifiers.

Unveiling Nonsecular Collisional Dissipation of Molecular Alignment.

We conducted a joint theoretical and experimental study to investigate the collisional dissipation of molecular alignment. By comparing experimental measurements to the quantum simulations, the nonsecular effect in the collision dissipation of molecular alignment was unveiled from the gas-density-dependent decay rates of the molecular alignment revival signals. Different from the conventional perspective that the nonsecular collisional effect rapidly fades within the initial few picoseconds following laser excitation, our simulations of the time-dependent decoherence process demonstrated that this effect can last for tens of picoseconds in the low-pressure regime. This extended timescale allows for the distinct identification of the nonsecular effect from molecular alignment signals. Our findings present the pioneering evidence that nonsecular molecular collisional dissipation can endure over an extended temporal span, challenging established concepts and strengthening our understanding of molecular dynamics within dissipative environments.

Ultrafast Picometer-Resolved Molecular Structure Imaging by Laser-Induced High-Order Harmonics.

Real-time visualization of molecular transformations is a captivating yet challenging frontier of ultrafast optical science and physical chemistry. While ultrafast x-ray and electron diffraction methods can achieve the needed subangstrom spatial resolution, their temporal resolution is still limited to hundreds of femtoseconds, much longer than the few femtoseconds required to probe real-time molecular dynamics. Here, we show that high-order harmonics generated by intense femtosecond lasers can be used to image molecules with few-ten-attosecond temporal resolution and few-picometer spatial resolution. This is achieved by exploiting the sensitive dependence of molecular recombination dipole moment to the geometry of the molecule at the time of harmonic emission. In a proof-of-principle experiment, we have applied this high-harmonic structure imaging (HHSI) method to monitor the structural rearrangement in NH_{3}, ND_{3}, and N_{2} from one to a few femtoseconds after the molecule is ionized by an intense laser. Our findings establish HHSI as an effective approach to resolve molecular dynamics with unprecedented spatiotemporal resolution, which can be extended to trace photochemical reactions in the future.

Methanooceanicella nereidis gen. nov., sp. nov., the first oceanic Methanocellaceae methanogen, isolated from potential methane hydrate bearing area offshore southwestern Taiwan.

A novel mesophilic, hydrogenotrophic methanogen, strain CWC-04T, was obtained from a sediment sample extracted from a gravity core retrieved at station 22 within the KP-9 area off the southwestern coast of Taiwan during the ORIII-1368 cruise in 2009. Cells of strain CWC-04T were rod-shaped, 1.4-2.9 µm long by 0.5-0.6 µm wide, and occurred singly. Strain CWC-04Tutilized formate, H2/CO2, 2-propanol/CO2 or 2-butanol/CO2 as catabolic substrates. The optimal growth conditions were 42 °C, 0.17 M NaCl and pH 5.35. The genomic DNA G+C content calculated from the genome sequence of strain CWC-04T was 46.19 mol%. Phylogenetic analysis of 16S rRNA gene revealed that strain CWC-04T is affiliated with the genus Methanocella. The 16S rRNA gene sequences similarities within strains Methanocella arvoryzae MRE50T, Methanocella paludicola SANAET and Methanocella conradii HZ254T were 93.7, 93.0 and 91.3 %, respectively. In addition, the optical density of CWC-04T culture dropped abruptly upon entering the late-log growth phase, with virus-like particles (150 nm in diameter) being observed on and around the cells. This observation suggests that strain CWC-04T harbours a lytic virus. Based on these phenotypic, phylogenetic and genomic results, we propose that strain CWC-04T represents a novel species of a novel genus in the family Methanocellaceae, for which the name Methanooceanicella nereidis gen. nov., sp. nov. is proposed. The type strain is CWC-04T (=BCRC AR10050T=NBRC 113165T).

Six novel species of the genus Methanoculleus isolated from various environments in Taiwan.

Taiwan is situated in the subtropical region and its geographical location and topographical features contribute to a rich ecological diversity and scenic landscapes. We investigated the diversity of methanogens in different environments of Taiwan using a culture-dependent method. This report presents the characterization and taxonomy of six hydrogenotrophic methanogens obtained from cold seep sediments (strain FWC-SCC1T and FWC-SCC3T), marine sediments (strain CWC-02T and YWC-01T), estuarine sediments (strain Afa-1T), and a hot spring well (strain Wushi-C6T) in Taiwan. The proposed names of the six novel species are Methanoculleus frigidifontis (type strain FWC-SCC1T=BCRC AR10056T=NBRC 113993T), Methanoculleus oceani (CWC-02T=BCRC AR10055T=NBRC 113992T), Methanoculleus methanifontis (FWC-SCC3T=BCRC AR10057T=NBRC 113994T), Methanoculleus nereidis (YWC-01T=BCRC AR10060T=NBRC 114597T), Methanoculleus formosensis (Afa-1T=BCRC AR10054T=NBRC 113995T), and Methanoculleus caldifontis (Wushi-06T=BCRC AR10059T= NBRC 114596T).

Strategy of Charge Compensation for High-Performance Ni2+-Activated MgAl2O4 Spinel Near-Infrared Phosphor Synthesis via the Sol-Gel Combustion Method.

Near-infrared (NIR) phosphor conversion light-emitting diodes (pc-LEDs) have great application potential as NIR light sources in many fields such as food analysis, night vision illumination, and bioimaging for noninvasive medical diagnosis. In general, phosphors synthesized by a high-temperature solid-phase method have large particle sizes and have to be processed to fine powders by a grinding process, which may introduce surface defects and lower the luminous efficiency. Here, we report a sol-gel sintering method with ammonium nitrate and citric acid as the sacrificing agents to synthesize high purity, nanosized (less than 50 nm) Zr4+/Ni2+ codoped MgAl2O4 spinel NIR phosphors, in which MgAl2O4 spinel is the matrix, Ni2+ is the luminous center, and Zr4+ acts as the charge compensator. We systematically characterized the crystal structures and NIR luminescence properties of the Ni2+-doped MgAl2O4 and the Zr4+/Ni2+ codoped MgAl2O4. Under 390 nm light excitation, the emission spectrum of the Ni2+-doped MgAl2O4 phosphor covers 900-1600 nm, the half-peak width is 251 nm, and the peak position is located at 1230 nm. We demonstrated that by incorporating small amounts of Zr4+ as the charge compensator, the NIR emission intensity of the Zr4+/Ni2+ codoped MgAl2O4 nanosized phosphor was doubled over that of the Ni2+-doped MgAl2O4 phosphor. The optimal content of the charge compensator was 2 mol %. More importantly, the inclusion of Zr4+ led to a NIR phosphor with improved thermal stability in luminous properties, and the luminous intensity measured at 100 °C was 33.83% of that measured at room temperature (20 °C). This study demonstrates that NIR phosphor nanomaterials with high-purity and enhanced optical properties can be designed and synthesized through the charge compensation strategy by a sol-gel sintering method.

Integrated analysis of transcriptome and metabolome reveals the regulatory mechanism of largemouth bass (Micropterus salmoides) in response to Nocardia seriolae infection.

Nocardia seriolae is a severe bacterial pathogen that has seriously affected the development of aquaculture industry. Largemouth bass (Micropterus salmoides) is a commercially significant freshwater fish that suffers a variety of environmental threats, including bacterial pathogens. However, the immune responses and metabolic alterations of largemouth bass to N. seriolae infection remain largely unclear. We discovered that N. seriolae caused pathological alterations in largemouth bass and shifted the transcript of immune-related and apoptotic genes in head kidney after infection. To answer the aforementioned question, a combined transcriptome and metabolome analysis was employed to explore the alterations in genes, metabolites, and metabolic pathways in largemouth bass following bacterial infection. A total of 3579 genes and 1929 metabolites are significant differentially changed in the head kidney post infection. In response to N. seriolae infection, host modifies the PI3K-Akt signaling pathway, TCA cycle, glycolysis, and amino acid metabolism. The integrated analysis of transcriptome and metabolome suggested that with the arginine metabolism pathway as the core, multiple biomarkers (arg gene, arginine) are involved in the antibacterial and immune functions of largemouth bass. Thus, we hypothesized that arginine plays a crucial role in the immune responses of largemouth bass against N. seriolae infection, and increasing arginine levels suitably is beneficial for the host against bacterial infection. Our results shed light on the regulatory mechanism of largemouth bass resistance to N. seriolae infection and contributed to the development of more effective N. seriolae resistance strategies.