Biofilms are accumulations of microorganisms embedded in extracellular matrices that protect against external factors and stressful environments. Cyanobacterial biofilms are ubiquitous and have ...potential for treatment of wastewater and sustainable production of biofuels. But the underlying mechanisms regulating cyanobacterial biofilm formation are unclear. Here, we report the solution NMR structure of a protein, Se0862, conserved across diverse cyanobacterial species and involved in regulation of biofilm formation in the cyanobacterium Synechococcus elongatus PCC 7942. Se0862 is a class α+β protein with ααββββαα topology and roll architecture, consisting of a four‐stranded β‐sheet that is flanked by four α‐helices on one side. Conserved surface residues constitute a hydrophobic pocket and charged regions that are likely also present in Se0862 orthologs.
PDB Code(s): 6UF2;
Hierarchical porosity and functionalization are recognized as two crucial parameters in mediating the catalytic performance of heterogeneous catalysts, however, they are rarely achieved ...simultaneously in the development of metal-organic frameworks (MOFs). In this work, a simple and efficient method has been developed to synchronously construct hierarchical porosity and functionalization within a sulfonic acid group functionalized microporous MOF via a palladium-reduction induced strategy, for the first time. The generation mechanism of the mesopore has been explained using two-dimensional 1H DQ-SQ MAS NMR. The content of the mesopore and the active sites within mesoPd@NUS-6 could be finely tuned by simply controlling Pd loading. Particularly, the combination of hierarchical porosity and functionalization, as well as the ultra-stable structure endow the composites with great potential in bulk, for adsorption and heterogeneous catalysis.
Display omitted
•Ionic liquids promote the CO2 cycloaddition reaction.•The core-shell structure can effectively avoid the leaching of active ILs.•Catalyst shows an excellent catalytic performance ...under solvent and co-catalyst free conditions.
The engineering of highly efficient and stable heterogeneous catalysts for catalytic conversion of CO2 to high value-added products is highly desirable but presents a great challenge. Herein, we reported the synthesis of a series of multifunctional IL@H-Zn/Co-ZIF composite catalysts with a unique porous hollow capsule structure and encapsulated amino-functionalized ionic liquids (ILs). The unique hollow capsule structure of IL@H-Zn/Co-ZIF provides sufficient space for loading active ILs (C2NH2Mim+Br−) and fast mass transfer of substrate molecules during catalysis. Furthermore, the microporous Zn-ZIF shell can effectively avoid the leaching of active ILs. Benefiting from the unique hollow structure, the resultant IL@H-Zn/Co-ZIF demonstrated excellent catalytic performance (>95% yield), and good recyclability (still remained about 90% activities after 5 cycles) when applied in the CO2 cycloaddition reaction under solvent and co-catalyst free conditions.
► Nanocellulose was isolated by homogeneous high pressure homogenization process. ► It was with 10–20nm in diameter and low crystallinity. ► The study is effective in high recovery of cellulose and ...recycled stratagem. ► It promotes chances for potential applications in the near future.
Nanocellulose from sugarcane bagasse was isolated by high pressure homogenization in a homogeneous media. Pretreatment with an ionic liquid (1-butyl-3-methylimidazolium chloride (BmimCl)) was initially involved to dissolve the bagasse cellulose. Subsequently, the homogeneous solution was passed through a high pressure homogenizer without any clogging. The nanocellulose was obtained at 80MPa for 30 cycles with recovery of 90% under the optimum refining condition. Nanocellulose had been characterized by Fourier transformed infrared spectra, X-ray diffraction, thermogravimetric analysis, rheological measurements and transmission electron microscopy. The results showed that nanocellulose was 10–20nm in diameter, and presented lower thermal stability and crystallinity than the original cellulose. The developed nanocellulose would be a very versatile renewable material.
Lung cancer is the leading cause of cancer‐related mortality in men and women globally. Non‐small cell lung cancer (NSCLC) is the most prevalent subtype, accounting for 85–90% of all cancers. ...Although there have been dramatic advances in therapeutic approaches in recent decades, the recurrence and metastasis rates of NSCLC are as high as 30–40% with the 5‐year overall survival rate being less than 15%. Therefore, it is necessary to explore the pathogenesis of NSCLC at the genetic level and identify prognostic biomarkers and novel therapeutic targets. Here, we aimed to identify mutated genes with high frequencies in Chinese NSCLC patients using next‐generation sequencing and to investigate their relationships with the tumor mutation burden (TMB) and tumor immune microenvironment. A total of 110 NSCLC patients were enrolled to profile the genetic variations. Mutations in EGFR (62.37%), TP53 (61.29%), LRP1B (13.98%), FAT1 (12.90%), KMT2D (11.83%), CREBBP (10.75%), and RB1 (9.68%) were most prevalent. TP53, LRP1B, KMT2D, and CREBBP mutations were all significantly associated with high TMB (P < 0.05 or P < 0.01). The infiltrating levels of immune cells and immune molecules were enriched significantly in the LRP1B mutation group. LRP1B mutations significantly correlated with stimulating and inhibitory immunoregulators. Gene set enrichment analysis revealed that cell cycle, the Notch signaling pathway, the insulin signaling pathway, and the mTOR signaling pathway are related to LRP1B mutations in the immune system. LRP1B mutations may be of clinical importance in enhancing the anti‐tumor immune response and may be a promising biomarker for predicting immunotherapy responsiveness.
LRP1B mutations are significantly associated with prognosis and with a higher tumor mutation burden in non‐small cell lung cancer (NSCLC). The infiltrating levels of immune cells and immune molecules are enriched significantly in the LRP1B mutation group. LRP1B mutations are significantly correlated with some stimulating and inhibitory immunoregulators. LRP1B may be a promising biomarker for predicting immunotherapy responsiveness for NSCLC.
Hierarchical semiconductors are the most important photocatalysts, especially for visible light-induced hydrogen production from water splitting. We demonstrate herein a hierarchical electrostatic ...assembly approach to hierarchical CdS/m-TiO2/G ternary photocatalyst, which exhibits high photoactivity and excellent photostability (more than twice the activity of pure CdS while 82% of initial photoactivity remained after 15 recycles during 80 h irradiation). The ternary nanojunction effect of the photocatalyst has been investigated from orbitals hybrid, bonding energy to atom-stress distortion and nano-interface fusion. And a coherent separation mechanism of charge carriers in the ternary system has been proposed at an atomic/nanoscale. This work offers a promising way to inhibit the photocorrosion of CdS and, more importantly, provide new insights for the design of ternary nanostructured photocatalysts with an ideal heterojunction.
A new insight into constructing a hierarchical ternary composite photocatalyst for visible light-induced hydrogen production from water splitting with high activity and stability by electric-triple-layer hierarchical assembly approach. The atomic-scaled heterojunctions of CdS/m-TiO2/G are beneficial for efficient transformation of photogenerated carriers from the semiconductor, which thus significantly enhance the CdS photoactivity and inhibited the CdS photocorrosion. Display omitted
•A hierarchical ternary photocatalyst has been prepared via electric-triple-layer synthesis.•The ternary photocatalyst exhibits an extremely high H2 production rate and long-term photostability.•The ternary nanojunction effect has been investigated from orbitals hybrid, bonding energy to atom-stress distortion and nano-interface fusion.
•Many congested commuting arterials may experience with heaving turning flows.•It is essential to provide progression for both through and turning path-flows.•This paper presents three multi-path ...progression models in response to such need.•The numerical results have confirmed the effectiveness of the proposed models.•The models can outperform existing methods in dealing with heavy turning flows.
To contend with congestion and spillback on commuting arterials, serving as connectors between freeway and surface-street flows, this paper presents three multi-path progression models to offer progression bands for multiple critical path-flows contributing to the high volume in each arterial link. The first proposed model is a direct extension of MAXBAND under a predetermined phasing plan, but using the path-flow data to yield the progression bands. The second model further takes the phase sequence at each intersection as a decision variable, and concurrently optimizes the signal plans with offsets for the entire arterial. Due to the competing nature of multi-path progression flows over the same green duration, the third model is proposed with a function to automatically select the optimal number of paths in their bandwidths maximization process. The results of extensive simulation studies have shown that the proposed models outperform conventional design methods, such as MAXBAND or TRANSYT, especially for those arterials with multiple heavy path-flows. The research results from this study have also reflected the need to collect more traffic pattern data such as major path-flow volumes, in addition to the typical intersection volume counts.
For the first time, a simple electrochemical co-deposition was utilized to synthesis the gold and zirconia nanocomposites modified graphene nanosheets on glassy carbon electrode (Au-ZrO2-GNs/GCE) for ...electrocatalytic analysis of methyl parathion (MP). According to Field-Emission Scanning Electron Microscopy (FE-SEM), Transmission Electronic Microscopy (TEM) and X-Ray Diffraction (XRD), the gold nanoparticles were uniformly distributed on the surface of graphene-based nanocomposite. The Au-ZrO2-GNs/GCE based sensor exhibited superior capacity for MP detection, ascribed to the strong affinity of zirconia towards the phosphoric group, as well as the high catalytic activity and good conductivity of Au-GNs. The best fabrication and work conditions were then obtained by systematically optimization of the electrodeposition process, pH value and enrichment time. Compared to the gold nanoparticles, zirconia or graphene modified electrodes, AuZrO2-GNs/GCE sensor displayed superior electro-catalytic response toward MP oxidation. The sensor response current of square wave voltammetry was highly linearly correlated with the MP concentrations range of 1–100 ng mL−1 and 100–2400 ng mL−1 with the detection limit of 1 ng mL−1. The Au-ZrO2-GNs/GCE nanocomposite sensor showed excellent accuracy and reproducibility for detection of MP in Chinese cabbage samples, providing a new method for efficient pesticide detection in practical applications.
Display omitted
•AuZrO2-GNs/GCE nanocomposite was synthesized via electrochemical co-deposition for the first time.•The nanocomposite was more sensitive for MP determination due to synergistic effect.•The sensor showed relatively wider linear range (1–100 ng mL−1 and 100–2400 ng mL−1).•The sensor can be practical application upon the excellent recovery results of Chinese cabbage.
•Dendrite-like gold nanostructures (DGNs) were obtained by a simple potentiostatic method.•The morphology and structure of DGNs could be easily tuned through the deposition conditions.•The DGNs with ...high ESA show superior electrocatalytic activity to glucose oxidation.•DGNs exhibit excellent stability and selectivity for nonenzymatic glucose detection.
Dendrite-like gold nanostructures (DGNs) were directly electrodeposited onto the surface of a glassy carbon electrode (GCE) via the potentiostatic method without any templates, surfactants, or stabilizers. The effects of the deposition time, potential and the concentration of precursor solution on the evolution of the nanostructure and on the electrocatalytic activity of the DGNs were systematically investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electrochemical methods including cyclic voltammetry, linear voltammetry and chronoamperometry. The results confirmed that DGNs have good electrocatalytic activity towards the electro-oxidation of glucose in a neutral phosphate buffer solution (PBS, pH 7.4). A non-enzymatic glucose sensor fabricated with the DGNs as an electrocatalyst showed a quick response (less than 2 s), a low detection limit (0.05mM), a wide and valuable linear range (0.1 - 25mM), a high sensitivity (190.7μAcm−2mM−1) and good repeatability and stability. In addition, the commonly interfering species, such as ascorbic acid (AA), uric acid (UA), and 4-acetaminophen (AP), did not cause obvious interference because of the use of a low detection potential (0.15V vs. Ag/AgCl). This work demonstrates a simple and an effective sensing platform for the non-enzymatic detection of glucose.
A highly efficient photoenergy conversion is strongly dependent on the cumulative cascade efficiency of the photogenerated carriers. Spatial heterojunctions are critical to directed charge transfer ...and, thus, attractive but still a challenge. Here, a spatially ternary titanium-defected TiO2@carbon quantum dots@reduced graphene oxide (denoted as V Ti@CQDs@rGO) in one system is shown to demonstrate a cascade effect of charges and significant performances regarding the photocurrent, the apparent quantum yield, and photocatalysis such as H2 production from water splitting and CO2 reduction. A key aspect in the construction is the technologically irrational junction of Ti-vacancies and nanocarbons for the spatially inside-out heterojunction. The new “spatial heterojunctions” concept, characteristics, mechanism, and extension are proposed at an atomic-/nanoscale to clarify the generation of rational heterojunctions as well as the cascade electron transfer.
PDF
