Investigation of highly reflective p-electrodes for AlGaN-based deep-ultraviolet light-emitting diodes.

We proposed a "Ni sacrifice" method to fabricate Al-based highly reflective p-electrode in the ultraviolet spectral region for AlGaN-based deep-ultraviolet light-emitting diodes (DUV-LEDs). The "Ni sacrifice" p-electrode could have a high optical reflectivity of around 90% at the DUV spectral region below 300 nm. Compared to Ni/Au, indium tin oxide (ITO), and Pd p-contacts, the "Ni sacrifice" led to a higher resistivity of p-contacts and a slightly higher operated voltage of the DUV-LEDs (within 0.6 V at 20 mA). Although the electrical performance was degraded slightly, the light output power and external quantum efficiency of the DUV-LEDs could be improved by utilizing the "Ni sacrifice" p-electrode. Besides, we introduced a grid of vias in the device mesa and reduced the diameter of the vias to achieve an enhanced peak external quantum efficiency (EQE) up to 1.73%. And the wall-plug efficiency (WPE) of DUV-LEDs with a "Ni sacrifice" p-electrode was higher than that of Ni/Au p-electrode DUV-LEDs at low currents. These results highlight the great potential of the proposed "Ni sacrifice" reflective p-electrode for use in DUV-LEDs.

Model of shrimp pond-mediated spatiotemporal dynamic distribution of antibiotic resistance genes in the mangrove habitat of a subtropical gulf.

Aquacultures are the main reason for the environmental selection of antibiotic resistance genes (ARGs), resulting in the enrichment of ARGs. As a filter, a marine mangrove ecosystem can reduce antimicrobial resistance (AMR) or eliminate ARGs; however, its elimination mechanism remains unclear. This study investigated the spatiotemporal dynamic distribution of ARGs in two different types of mangrove habitats (shrimp ponds and virgin forests), within a subtropical gulf located in the Beibu Gulf, China, during dry and wet seasons by using metagenomics and real time quantitative polymerase chain reaction (RT-qPCR) analysis. As the key environmental factors, sulfide, salinity, and mobile genetic elements significantly were found to contribute to ARGs distribution, respectively. Wet and dry seasons influenced the dispersal of ARGs but did not affect the microbial community structure. Three potential biomarkers, TEM-116, smeD, and smeE, played key roles in seasonal differences. The key different genes in the biological relevance of absolute abundance were demonstrated by RT-qPCR. Co-occurrence network analysis indicated that high-abundance ARGs were distributed in a modular manner. For the first time, a risk index weighted by risk rank (RIR) was proposed and used to quantify the human risk of ARGs in the mangrove metagenome. The shrimp ponds during the wet season showed the highest RIR detected. In addition to offering a perspective on reducing AMR in mangrove wetlands, this study constructed the first spatiotemporal dynamic model of ARGs in the Beibu Gulf, China and contributed to revealing the global spread of ARGs. Meanwhile, this study proposes a new pipeline for assessing the risk of ARGs, while also exploring the concept of "One Health."

Deciphering the biodesulfurization pathway employing marine mangrove Bacillus aryabhattai strain NM1-A2 according to whole genome sequencing and transcriptome analyses.

In the biogeochemical cycle, sulfur oxidation plays a vital role and is typically referred to as the elemental sulfur or reductive sulfide oxidation process. This study aimed to characterize a subtropical mangrove-isolated bacterial strain using biochemical, whole-genome, and transcriptome sequencing analyses to enhance our understanding of sulfur metabolism and biodegradation from a molecular genetic perspective. Strain NM1-A2 was characterized as Gram-positive and found to have a close molecular phylogenetic relationship with Bacillus aryabhattai. NM1-A2 efficiently converted dibenzothiophene (DBT) into 2-hydroxybiphenyl (2-HBP) via a 4S pathway with 95% efficiency, using enzymes encoded by the dsz operon (dszA, dszB, and dszC), which determine monooxygenases (DszA & DszC) and desulfinase (DszB). The whole-genome sequence of NM1-A2 had a length of approximately 5,257,678 bp and included 16 sulfur metabolism-related genes, featuring the ABC transport system, small subunit (ssu) and cysteine (cys) gene families, and adenosine 5'-phosphosulfate (APS) and 3'-phosphoadenosine-5'-phosphosulfate (PAPS) biosynthesis-related genes. Transcriptomic analysis of NM1-A2 using three sulfur groups-magnesium sulfate (MS), sulfur powder (SP), and sodium thiosulfate (ST) resulted in a significant number of differentially expressed genes (1200, 2304, and 2001, respectively). This analysis revealed that intracellular cysteine concentration directly regulated the expression of cys and ssu genes. Sulfate did not directly affect cys gene expression but repressed ssu gene expression. The cys gene expression levels decreased during the conversion of sulfate to sulfide and cysteine. The transcriptomic data was validated by analyzing the expression patterns of NM1-A2 using real-time quantitative PCR validation analysis. The expression levels of cysl, mccB, and nrnA were significantly upregulated, while cysH, metB, and sat were downregulated in the SP, ST, and MS groups, respectively. This research contributes to our understanding of marine mangrove microorganisms' bacterial efficiency through characterization, whole-genome, and transcriptome sequencing-based molecular degradation of organic compounds in the mangrove ecosystem, which may enhance nutrient availability.

Integration of Microbial Transformation Mechanism of Polyphosphate Accumulation and Sulfur Cycle in Subtropical Marine Mangrove Ecosystems with Spartina alterniflora Invasion.

Excessive phosphorus can lead to eutrophication in marine and coastal ecosystems. Sulfur metabolism-associated microorganisms stimulate biological phosphorous removal. However, the integrating co-biotransformation mechanism of phosphorus and sulfur in subtropical marine mangrove ecosystems with Spartina alterniflora invasion is poorly understood. In this study, an ecological model of the coupling biotransformation of sulfur and phosphorus is constructed using metagenomic analysis and quantitative polymerase chain reaction strategies. Phylogenetic analysis profiling, a distinctive microbiome with high frequencies of Gammaproteobacteria and Deltaproteobacteria, appears to be an adaptive characteristic of microbial structures in subtropical mangrove ecosystems. Functional analysis reveals that the levels of sulfate reduction, sulfur oxidation, and poly-phosphate (Poly-P) aggregation decrease with increasing depth. However, at depths of 25-50 cm in the mangrove ecosystems with S. alterniflora invasion, the abundance of sulfate reduction genes, sulfur oxidation genes, and polyphosphate kinase (ppk) significantly increased. A strong positive correlation was found among ppk, sulfate reduction, sulfur oxidation, and sulfur metabolizing microorganisms, and the content of sulfide was significantly and positively correlated with the abundance of ppk. Further microbial identification suggested that Desulfobacterales, Anaerolineales, and Chromatiales potentially drove the coupling biotransformation of phosphorus and sulfur cycling. In particular, Desulfobacterales exhibited dominance in the microbial community structure. Our findings provided insights into the simultaneous co-biotransformation of phosphorus and sulfur bioconversions in subtropical marine mangrove ecosystems with S. alterniflora invasion.

Low-level controllable blue LEDs irradiation enhances human dental pulp stem cells osteogenic differentiation via transient receptor potential vanilloid 1.

Human dental pulp stem cells (hDPSCs) have attracted tremendous attention in tissue regeneration engineering due to their excellent multidirectional differentiation potential. Photobiomodulation (PBM) using low-level light-emitting diodes (LEDs) or lasers has been proved to promote the osteogenesis of mesenchymal stem cells. However, the effect of LEDs on osteogenic differentiation of hDPSCs has little published data. In this work, the effect of blue LEDs with different energy densities of 2, 4, 6, 8, 10 J/cm2 on osteogenic differentiation of hDPSCs was examined by using in vitro ALP staining, ALP activity, mineralization, and real-time PCR. The results showed that compared with the control group, osteogenic differentiation was significantly enhanced in blue LEDs treated groups. As the energy density increased, the level of osteogenesis initially increased and then decreased reaching the highest level at 6 J/cm2. Transient receptor potential vanilloid 1 (TRPV1), a Ca2+ ion channel, was believed to be a potential player in osteogenesis by photobiomodulation. By immunofluorescence assay, calcium influx assay, PCR, and ALP staining, it was shown that blue LEDs irradiation can increase the activity of TRPV1 and intracellular calcium levels similarly to the agonist of TRPV1 capsaicin. Additionally, pretreatment with capsazepine, a selective TRPV1 inhibitor, was able to abrogate the osteogenic effect of blue LEDs. In conclusion, these findings proposed that blue LEDs can promote the osteogenesis of hDPSCs within the appropriate range (4-8 J/cm2) during culture of osteogenic medium, and TRPV1/Ca2+ may be an essential signaling pathway involved in blue LEDs-induced osteogenesis, providing new insights for the use of hDPSCs in tissue regeneration engineering.

Effects of Spartina alterniflora Invasion on Nitrogen Fixation and Phosphorus Solubilization in a Subtropical Marine Mangrove Ecosystem.

Nitrogen fixation (NF) and phosphorus solubilization (PS) play a key role in maintaining the stability of mangrove ecosystems. In China, the invasion of Spartina alterniflora has brought a serious threat to the mangrove ecosystem. However, systematic research on NF and PS in mangrove sediments has not been conducted, and limited studies have focused on the response of NF and PS to S. alterniflora invasion, particularly at different sediment depths. In the present study, shotgun metagenomics and quantitative PCR were used to study the 0- to 100-cm sediment profile of the mangrove ecosystem in the Beibu Gulf of China. Results showed that the PS potential of mangrove sediments was primarily caused by enzymes encoded by phoA, phoD, ppx, ppa, and gcd genes. S. alterniflora changed environmental factors, such as total nitrogen, total phosphorus, and total organic carbon, and enhanced the potential of NF and PS in sediments. Moreover, most microorganisms involved in NF or PS (NFOPSMs) responded positively to the invasion of S. alterniflora. Cd, available iron, and salinity were the key environmental factors that affected the distribution of NF and PS genes (NFPSGs) and NFOPSMs. A strong coupling effect was observed between NF and PS in the mangrove ecosystem. S. alterniflora invasion enhanced the coupling of NF and PS and the interaction of microorganisms involved in NF and PS (NFAPSM), thereby promoting the turnover of NP and improving sediment quality. Finally, 108 metagenome-assembled genomes involved in NF or PS were reconstructed to further evaluate NFOPSMs. IMPORTANCE This study revealed the efficient nutrient cycling mechanism of mangroves. Positive coupling effects were observed in sediment quality, NF and PS processes, and NFOPSMs with the invasion of S. alterniflora. This research contributed to the understanding of the effects of S. alterniflora invasion on the subtropical mangrove ecosystem and provided theoretical guidance for mangrove protection, restoration, and soil management. Additionally, novel NFOPSMs provided a reference for the development of marine biological fertilizers.

MicrobioSee: A Web-Based Visualization Toolkit for Multi-Omics of Microbiology.

With the upgrade and development of the high-throughput sequencing technology, multi-omics data can be obtained at a low cost. However, mapping tools that existed for microbial multi-omics data analysis cannot satisfy the needs of data description and result in high learning costs, complex dependencies, and high fees for researchers in experimental biology fields. Therefore, developing a toolkit for multi-omics data is essential for microbiologists to save effort. In this work, we developed MicrobioSee, a real-time interactive visualization tool based on web technologies, which could visualize microbial multi-omics data. It includes 17 modules surrounding the major omics data of microorganisms such as the transcriptome, metagenome, and proteome. With MicrobioSee, methods for plotting are simplified in multi-omics studies, such as visualization of diversity, ROC, and enrichment pathways for DEGs. Subsequently, three case studies were chosen to represent the functional application of MicrobioSee. Overall, we provided a concise toolkit along with user-friendly, time-saving, cross-platform, and source-opening for researchers, especially microbiologists without coding experience. MicrobioSee is freely available at https://microbiosee.gxu.edu.cn.

Whole-Genome and Transcriptome Sequencing-Based Characterization of Bacillus Cereus NR1 From Subtropical Marine Mangrove and Its Potential Role in Sulfur Metabolism.

Sulfur, organosulfur compounds, and sulfides are essential parts of life. Microbial sulfate assimilation is among the most active and ancient metabolic activities in the sulfur cycle that operates in various ecosystems. We analyzed the molecular basis of bacterial characterization. NR1 was isolated and purified from mangrove sediments. Whole-genome sequencing indicated that the NR1 isolate was closely related to Bacillus cereus. The genome contained 5,305 functional genes with a total length of 5,420,664 bp, a GC content of 35.62%, 42 rRNA, and 107 tRNA. DBT-grown cultures exhibited DBT utilization, fleeting emergence of DBT sulfone (DBTO2), and formation of 2-hydroxybiphenyl (2-HBP). Molecular analysis of the PCR products' dsz operon revealed the presence of dszA, dszB, and dszC genes, which encoded for NR1's 90% DBT desulfurization activity. Furthermore, 17 sulfur metabolism-related genes, including genes involved in assimilation sulfate reduction, APS and PAPS, and the cys, ssu, and TST gene families, were identified. In sulfate media, alkenesulfonate was converted to sulfite and inhibited ssu enzymes. Downregulated cysK variants were associated with nrnA expression and the regulation of L-cysteine synthesis. These findings established a scientific foundation for further research and application of bacteria to mangrove rehabilitation and ecological treatment by evaluating the bacterial characterization and sulfur degradation metabolic pathway. We used whole-genome and transcriptome sequencing to examine their genetic characteristics.

Improved Optical and Electrical Characteristics of GaN-Based Micro-LEDs by Optimized Sidewall Passivation.

GaN-based Micro-LED has been widely regarded as the most promising candidate for next generation of revolutionary display technology due to its advantages of high efficiency, high brightness and high stability. However, the typical micro-fabrication process would leave a great number of damages on the sidewalls of LED pixels, especially for Micro-LEDs, thus reducing the light emitting efficiency. In this paper, sidewall passivation methods were optimized by using acid-base wet etching and SiO2 layer passivation. The optical and electrical characteristics of optimized Micro-LEDs were measured and analyzed. The internal quantum efficiency (IQE) of Micro-LED was increased to 85.4%, and the reverse leakage current was reduced down to 10-13 A at -5 V. Optimized sidewall passivation can significantly reduce the non-radiative recombination centers, improving the device performance and supporting the development of high-resolution Micro-LED display.

Carbonized Tree-Like Furry Magnolia Fruit-Based Evaporator Replicating the Feat of Plant Transpiration.

It has long been an aspirational goal to create artificial evaporators that allow omnidirectional energy absorptance, adequate water supply, and fast vapor transportation, replicating the feat of plant transpiration, to solve the global water crisis. This work reveals that magnolia fruits, as a kind of tree-like living organism, can be outstanding 3D tree-like evaporators through a simple carbonization process. The arterial pumping, branched diffusion, and confined evaporation are achieved by the "trunk," "branches," and "leaves," respectively, of the mini tree. The mini tree possesses omnidirectional high light absorptance with minimized heat loss and gains energy from the environment. Water confined in the fruit possesses reduced vaporization enthalpy and transports quickly following the Murray's law. A record-high vapor generation rate of 1.22 kg m-2 h-1 in dark and 3.15 kg m-2 h-1 under 1 sun illumination is achieved under the assistance of the gully-like furry surface. The "absorption of nutrients" enables the fruit to recover valuable heavy metals as well as to produce clean water from wastewater efficiently. These findings not only reveal the hidden talent of magnolia fruits as cheap materials for vapor generation but also inspire future development of high-performance, full-time, and all-weather vapor generation and water treatment devices.