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As an important microbial exopolysaccharide, the sphingan WL gum could be widely used in petroleum, food, and many other fields. However, its lower production is still limiting its wider application. Therefore, to gain insights into the bottlenecks of WL gum production by identifying the key enzymes in the WL gum biosynthesis pathway, more than 20 genes were over-expressed in Sphingomonas sp. WG and their effects on WL gum production and structure were investigated. Compared to the control strain, the WL gum production of welB over-expression strain was increased by 19.0 and 21.0% at 36 and 84 h, respectively. The WL gum production of both atrB and atrD over-expression strains reached 47 g/L, which was approximately 34.5% higher than that of the control strain at 36 h. Therefore, WelB, AtrB, and AtrD may be the key enzymes in WL production. Interestingly, the broth viscosity of most over-expression strains decreased, especially the welJ over-expression strain whose viscosity decreased by 99.3% at 84 h. Polysaccharides’ structural features were investigated to find the critical components in viscosity control. The uronic acid content and total sugar content was affected by only a few genes, therefore, uronic acid and total sugar content may be not the key composition. In comparison, the acetyl degrees were enhanced by over-expression of most genes, which meant that acetyl content may be the critical factor and negatively correlated with the apparent viscosity of WL gum. This work provides useful information on the understanding of the bottlenecks of WL gum biosynthesis and will be helpful for the construction of high WL gum-yielding strains and rheological property controlling in different industries.

Developing efficient strategies for sensitive detection of microRNAs, the noncoding bioactive molecules and well-established biomarkers, has aroused great interests due to its great potential values in genetic and pathological analyses. Herein, a highly selective and disposable paper-based photoelectrochemical (PEC) sensor was rationally designed for sensing microRNA based on simple self-assembly of a target-triggerable DNA motor and nanozyme-catalyzed multistage biocatalytic precipitation reaction. Specifically, a brand-new type II heterojunction of TiO

Additional file 1. Fig. S1. IFN-�� did not affect PD-L1 expression in the treatment macrophages. (A) The THP-1 macrophages were treated with Exo-ER, IFN-��, or PBS (Blank), followed by the detection of the PD-L1 mRNA (A) and protein levels (B and C) (n = 2-3) (*P < 0.05 and **P < 0.01; NS, no significance). Fig. S2. Knockdown of PD-L1 in HN4 cells and HN4-derived exosomes. HN4 cells were transfected with siPD-L1 or siNC, and exosomes were collected. (A-C) PD-L1 mRNA and protein level were detected in treatment HN4 cells by qRT-PCR (A) and Western blot (B and C). (D-E) Exosomal PD-L1 protein level was detected in treatment HN4 cells (n = 2-3) (*P < 0.05 and **P < 0.01). Fig. S3. Overexpression of PD-L1 promoted M2 polarization in macrophages. qRT-PCR analysis of CD206 mRNA in THP-1 macrophages transfected with plasmid encoding control (OE-NC) or PD-L1 (OE-PD-L1) (n = 3) (**P < 0.01). Table S1. RNA sequence used in this paper. Table S2. Clinicopathologic features of OSCC patients.

Nowadays, knowledge map as an efficient tool of knowledge management is widely used in various fields. In this paper, addressing the operational support of aerospace manufacturers, we explore the construction method of knowledge map and possible applications. We propose a five-step procedure for knowledge map construction, consisting of knowledge definition, knowledge extraction, knowledge description, knowledge links and knowledge map creation. Following this procedure, the knowledge map of operational support system for aerospace manufacturers is constructed in an example way. We also show the potential applications of knowledge map in aerospace manufactures.

Signature is one of the most prevailing identity authorization approaches. It is yet inconvenient to use in real life in the sense that a majority of existing signature verification approaches rely on additional digital signing devices. In this paper, we propose a portable device-free signature verification system named SilentSign which makes use of acoustic sensors (i.e., microphone and speaker) embedded in smart devices to enable secure and convenient signature verification service. The basic idea is to leverage acoustic signals to measure the distance variation of the tip of the pen while signing. We carefully design the signal modulation scheme, develop a phase-based distance measurement technique, and train the verification model for high performance and robustness. Compared with conventional digital signing systems, SilentSign allows users to sign more invisibly and conveniently. We conduct extensive experiments involving 35 participants to evaluate SilentSign. Results show that SilentSign can achieve 98.2% AUC and 1.25% EER.

High development velocity is critical for modern systems. This is especially true for Linux file systems which are seeing increased pressure from new storage devices and new demands on storage systems. However, high velocity Linux kernel development is challenging due to the ease of introducing bugs, the difficulty of testing and debugging, and the lack of support for redeployment without service disruption. Existing approaches to high-velocity development of file systems for Linux have major downsides, such as the high performance penalty for FUSE file systems, slowing the deployment cycle for new file system functionality. We propose Bento, a framework for high velocity development of Linux kernel file systems. It enables file systems written in safe Rust to be installed in the Linux kernel, with errors largely sandboxed to the file system. Bento file systems can be replaced with no disruption to running applications, allowing daily or weekly upgrades in a cloud server setting. Bento also supports userspace debugging. We implement a simple file system using Bento and show that it performs similarly to VFS-native ext4 on a variety of benchmarks and outperforms a FUSE version by 7x on 'git clone'. We also show that we can dynamically add file provenance tracking to a running kernel file system with only 15ms of service interruption., Comment: 14 pages, 6 figures, to be published in FAST 2021

Representative biomarkers (e.g., n-alkanes), diversity and microbial community in the aquifers contaminated by high concentration of arsenic (As) in different sediment depth (0–30 m) in Jianghan Plain, Hubei, China, were analyzed to investigate the potential mechanism of As enrichment in groundwater. The concentration of As was abundant in top soil and sand, but not in clay. The analysis of the distribution of n-alkanes, CPI values, and wax to total n-alkane ratio (Wax(n)%) indicated that the organic matter (OM) from fresh terrestrial plants were abundant in the shallow sediment. However, n-alkanes have suffered from significant biodegradation from the depth of 16 m to 30 m. The deposition of fresh terrestrial derived organic matters may facilitate the release of As from sediment to groundwater in the sediment of 0–16 m. However, the petroleum derived organic matters may do the favor to the release of As in the deeper section of borehole (16 m to 30 m). The 16S rRNA gene sequences identification indicated that Acidobacteria, Actinomycetes and Hydrogenophaga are abundant in the sediments with high arsenic. Therefore, microbes and organic matters from different sources may play important roles in arsenic mobilization in the aquifers of the study area.