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Background: Many studies have been conducted on essentiality prediction in the Saccharomyces cerevisiae genome, but the accuracy is not as high as those in bacterial or human genomes. The most frequently used features are Protein-Protein Interaction (PPI) networks combined with some other features, such as evolutionary conservation, expression level, and protein domain information. Sequence composition features are the least used features. Objective: To improve the accuracy of essentiality prediction in the Saccharomyces cerevisiae genome, we proposed a highly accurate gene essentiality prediction algorithm. Methods: In this paper, we propose an algorithm based on a linear Support Vector Machine (SVM) using sequence features only. The variables in this paper are derived from sequence data based on the w-nucleotide Z curve format without any other information. Results: After feature selection, the best area under the receiver operating characteristic curve (AUC) was 0.944 for 5-fold cross-validation. From 1- to 6-nucleotide Z curve variables, feature extraction can increase the AUC in all cases. Conclusion: The prediction on sequence composition is only promising, particularly when a feature filtering method is used, and maybe a good complement for algorithms based on other features.

Background Xylanase, an important accessory enzyme that acts in synergy with cellulase, is widely used to degrade lignocellulosic biomass. Thermostable enzymes with good catalytic activity at lower temperatures have great potential for future applications in the feed and fuel industries, which have distinct demands; however, the potential of the enzymes is yet to be researched. Results In this study, a structure-based semi-rational design strategy was applied to enhance the low-temperature catalytic performance of Bispora sp. MEY-1 XYL10C_∆N wild-type (WT). Screening and comparisons were performed for the WT and mutant strains. Compared to the WT, the mutant M53S/F54L/N207G exhibited higher specific activity (2.9-fold; 2090 vs. 710 U/mg) and catalytic efficiency (2.8-fold; 1530 vs. 550 mL/s mg) at 40 °C, and also showed higher thermostability (the melting temperature and temperature of 50% activity loss after 30 min treatment increased by 7.7 °C and 3.5 °C, respectively). Compared with the cellulase-only treatment, combined treatment with M53S/F54L/N207G and cellulase increased the reducing sugar contents from corn stalk, wheat bran, and corn cob by 1.6-, 1.2-, and 1.4-folds, with 1.9, 1.2, and 1.6 as the highest degrees of synergy, respectively. Conclusions This study provides useful insights into the underlying mechanism and methods of xylanase modification for industrial utilization. We identified loop2 as a key functional area affecting the low-temperature catalytic efficiency of GH10 xylanase. The thermostable mutant M53S/F54L/N207G was selected for the highest low-temperature catalytic efficiency and reducing sugar yield in synergy with cellulase in the degradation of different types of lignocellulosic biomass. Graphic Abstract Supplementary Information The online version contains supplementary material available at 10.1186/s13068-021-02044-3., Highlights Key sites were proved to promote low-temperature catalytic efficiency of xylanase.Thermostable mutant with improved catalytic efficiency at 40 °C was obtained.Synergistic hydrolysis was dramatically improved between the mutant and cellulase.Agricultural wastes were converted into fermentable sugars by enzymolysis. Supplementary Information The online version contains supplementary material available at 10.1186/s13068-021-02044-3.

Combination therapy has attracted extensive interest in alleviating the shortcomings of monotherapy and enhancing the treatment efficacy. In this work, hollow mesoporous silica nanoparticles (HMSNs) play the role of nanocarriers in the delivery of Cu(II)-doped polydopamine (PDA), termed as HMSNs@PDA-Cu, for synergistic therapy. PDA acts as a traditional photothermal agent to realize photothermal treatment (PTT). Chemodynamic therapy (CDT) is realized by the reaction of Cu(II) with intracellular glutathione (GSH), and subsequently, the generated Cu(I) reacts with H2O2 to produce toxic hydroxyl radical (•OH) through a Fenton-like reaction. The photothermal performance of PDA is improved after its coordination with Cu(II). On the other hand, PDA exhibits superoxide dismutase (SOD)-mimicking activity. PDA converts O2•- to H2O2 and improves the production of H2O2, which promotes the therapeutic effect of CDT. Moreover, the high temperature caused by PTT further enhances the yield of •OH for CDT. This nanotheranostic platform perfectly applied to the tumor depletion of mice, presenting great potential for cancer metastasis therapy in vitro and in vivo.

The iodofluorination of alkynyl and alkenyl MIDA (N-methyliminodiacetyl) boronates led to the synthesis of two types of fluorinated organoborons bearing a valuable C-I bond. The B(MIDA) moiety confers exclusive regioselectivity to the reaction, and the products were formed in generally good yields. Preliminary utility of the products was demonstrated.

β-Difluorinated alkyl halides are of significant value in the modular synthesis of gem-difluorinated molecules. An exclusive 1,2-halo migratory gem-difluorination of vinyl halides with in situ-generated PhIF2·HF is described. This protocol provides a general and practical approach towards a wide variety of β-difluorinated alkyl bromides. Both α- and β-bromoalkyl alkenes are suitable substrates, leading to two distinct types of products. The extension of this protocol to vinyl chloride and iodide are also feasible. The synthetic versatility of this method has been highlighted by the late-stage modification of complex small molecules and further transformations of the β-difluorinated alkyl halides to valuable CF2-containing compounds.

Diabetes is one of the metabolic diseases marked by hyperglycemia and is often accompanied by the occurrence of some complications. As a biomarker of oxidative stress, hydrogen peroxide (H2O2) has close association with the occurrence and development of diabetes and its complications. Unfortunately, there is no fluorescent probe reported for imaging H2O2 in diabetic mice. Here, a novel near-infrared (NIR) fluorescent probe named QX-B was designed and synthesized to detect H2O2. For the probe, the quinolinium-xanthene dye is used as the fluorophore and borate ester is chosen as the response group. After the addition of H2O2, a strong NIR fluorescence signal at 772 nm is observed. The probe not only shows high sensitivity with 10-fold enhancement but also displays excellent selectivity to H2O2 over other possible interfering species. In the meantime, the possible response mechanism of QX-B toward H2O2 was proposed and verified by the high-performance liquid chromatography (HPLC) experiment, mass spectra (MS) experiment, and density functional theory (DFT) calculation. Furthermore, based on the low cell cytotoxicity of QX-B, it has been applied in imaging exogenous and endogenous H2O2 in HeLa cells, HCT116 cells, 4T1 cells, and zebrafish successfully. More importantly, inspired by the performance of NIR fluorescence, QX-B has been used in monitoring H2O2 in diabetic mice for the first time. This provides very important information for the diagnosis and treatment of diabetes and its complications.

Sodium- and potassium-ion batteries have attracted intensive attention recently as low-cost alternatives to lithium-ion batteries with naturally abundant resources. However, the large ionic radii of Na+ and K+ render their slow mobility, leading to sluggish diffusion in host materials. Herein, hierarchical FeSe2 microspheres assembled by closely packed nano/microrods are rationally designed and synthesized through a facile solvothermal method. Without carbonaceous material incorporation, the electrode delivers a reversible Na+ storage capacity of 559 mA h g-1 at a current rate of 0.1 A g-1 and a remarkable rate performance with a capacity of 525 mA h g-1 at 20 A g-1 . As for K+ storage, the FeSe2 anode delivers a high reversible capacity of 393 mA h g-1 at 0.4 A g-1 . Even at a high current rate of 5 A g-1 , a discharge capacity of 322 mA h g-1 can be achieved, which is among the best high-rate anodes for K+ storage. The excellent electrochemical performance can be attributed to the favorable morphological structure and the use of an ether-based electrolyte during cycling. Moreover, quantitative study suggests a strong pseudocapacitive contribution, which boosts fast kinetics and interfacial storage.

Minimization and stabilization of arsenic-containing smelting wastewater and residue is of crucial issue to resolve the arsenic contamination. Calcium arsenate is a typical precipitate produced from disposal of smelting acid wastewater. However, it suffers from poor stability and large quantity in the aqueous environment. Copper slags, as for rich-iron species materials, are disposed of in landfills or open-air tailing ponds, which are another waste material that have not been effectively utilized for reuse application. In this study, strategy for sequence of phase-controlled and thermal-doped copper slag technique was used as the efficient means of minimization and stabilization of arsenic-bearing resides. Detailed results were showed that stepwise phase precipitation significantly reduced the formation of hazardous solid waste; the total solid waste was reduced 47.0 wt% because the gypsum was separated from arsenic calcium residues through two-step methods. Subsequently, solid waste stabilization was achieved by using thermal-doped slag, and the high yield of magnetite (75.6 wt%) and fayalite (22.7 wt%) was produced from copper slags. It was proved that these iron-rich species displayed the remarkable performance to stabilize arsenic due to the formation of Fe-As-Ca-O complex; compared with the raw solid waste, the arsenic leachability was decreased from 280.75 to 1.05 mg/L via copper slag stabilization process. The immobilized arsenic content was 25.0 wt%. Overall, the proposed strategy for stepwise phase-controlled and thermal-doped copper slags was a potentially effective strategy for reducing emissions and pollution of arsenic-containing wastewater and residue.

The synthesis of borylated organofluorines is of great interest due to their potential values as synthons in modular construction of fluorine-containing molecules. Reported herein is a rhodium-catalyzed hydroboration of aryl gem-difluoroalkenes leading to a series of α-difluoromethylated benzylborons. The use of cationic rhodium catalyst and a biphosphine ligand with large bite angle was crucial for reactivity by offering good regioselectivity and diminishing the undesired β-F elimination. Preliminary derivatizations of the products were conducted to showcase the utility of this protocol.

A novel theranostic probe called CX-B-DF is constructed for precise chemotherapy guided by near-infrared (NIR) fluorescence imaging. Moreover, the theranostic probe shows high cytotoxicity to cancer cells under dual activation (H2O2 and TP), which causes the accuracy of drug release to be improved and the toxic side effects to be reduced.

Chemodynamic therapy (CDT) is a new emerging strategy for the in situ treatment of tumors. In the microenvironment of tumor cells, CDT may be achieved through the generation of reactive oxygen species (ROS), e.g., hydroxyl radicals (˙OH) and singlet oxygen (1O2), which induce the death of tumor cells. Copper (Cu) or other transition-metal ions catalyze the production of ˙OH by hydrogen peroxide (H2O2) through Fenton or Fenton-like reactions. With the development of advanced nanotechnology, nanotherapeutic systems with Cu-based nanostructures have received extensive attention and have been demonstrated for their wide applications in the design and construction of nanotherapeutic systems for CDT, along with multimodal synergistic therapy. Herein, the cutting-edge developments of Cu-based nanostructures in CDT are reviewed and discussed, by focusing on the monotherapy of CDT as well as synergistic treatments by hyphenating CDT with various therapeutic protocols, e.g., photothermal therapy (PTT), photodynamic therapy (PDT), sonodynamic therapy (SDT), and so on. In addition, the potential challenges and future perspectives are described in the improvement of CDT therapeutic efficacy, the enhancement of targeting capability, and mechanistic investigations on CDT therapy.

Thanks to their intrinsic merits of low cost and natural abundance, potassium-ion batteries have drawn intense interest and are regarded as a possible replacement for lithium-ion batteries. The larger radius of potassium, however, provides slow mobility, which normally leads to sluggish diffusion of host materials and eventual expansion of volume, typically resulting in electrode failure. To address these issues, we design and synthesize an effective micro-structure with Co9S8 nanoparticles segregated in carbon fiber utilizing a concise electrospinning process. The anode delivers a high K+ storage capacity of 721 mA h g−1 at 0.1 A g−1 and a remarkable rate performance of 360 mA h g−1 at a high current density of 3 A g−1. A small charge-transfer resistance and a high pseudocapacitive contribution that benefit fast potassium ion migration are indicated by quantitative analysis. The outstanding electrochemical performance can be attributed to the distinct architecture design facilitating high active electrode–electrolyte area and fast kinetics as well as controlled volume expansion.

Discrete and polymeric coordination complexes, namely [Cu2L4(ClO4)4]·2CH2Cl2·CH3OH (1), [Cu2L2(NO3)4(CH3OH)2] (2) and {[Cu2L4(NO3)4]}n (3), were obtained using bridged pyridine ligand 4-methyl-2,6-bis(pyridinyl-3-ethynyl)aniline (L) and Cu(II) salts in CH2Cl2/MeOH. The structure of the Cu2L4 cage or Cu2L2 macrocycle was generated depending on the selection of the anion (ClO4−/NO3−). The heterogeneous Fenton reaction experiments using H2O2 showed that discrete coordination complexes are good photocatalysts in which the Cu–N bond plays a major role in the photocatalytic degradation. The degradation mechanism could be described as a synergistic process of the Fenton reaction and high-valence copper ions using t-butanol as the hydroxyl radical scavenger. The photocatalytic degradation of methylene blue (MB) experiments showed that the photodegradation efficiency of the coordination complexes is higher than that of the polymeric Cu-MOFs.

The design of a powerful heterojunction structure and the study of the interfacial charge migration pathway at the atomic level are essential to mitigate the photocorrosion and recombination of electron-hole pairs of CdS in photocatalytic hydrogen evolution (PHE). A temperature-induced self-assembly strategy has been proposed for the syntheses of Prussian blue analogue (PBA)/CdS nanocomposites with beaded structure. The specially designed structure had evenly exposed CdS which can efficiently harvest visible light and inhibit photocorrosion; meanwhile, PBA with a large cavity provided channels for mass transfer and photocatalytic reaction centers. Remarkably, PB-Co/CdS-LT-3 exhibits a PHE rate of 57 228 μmol h-1 g-1, far exceeding that of CdS or PB-Co and comparable to those of most reported crystalline porous material-based photocatalysts. The high performances are associated with efficient charge migration from CdS to PB-Co through CN-Cd electron bridges, as revealed by the DFT calculations. This work sheds light on the exploration of heterostructure materials in efficient PHE.

An efficient nickel-catalyzed, iron-mediated hydrofluoroalkylation of alkynes with bromodifluoroacetate or perfluoroalkyl iodide was developed. The reactions proceeded efficiently via a radical reaction pathway to give fluoroalkylated (Z)-alkenes in moderate to good yields with good control of stereoselectivity (up to 99 : 1 Z/E), exhibiting both wide substrate scope and broad functional group tolerance. In addition, the method also entailed the easy functionalization of alkyne-tethered complex molecules derived from sugars and pharmaceuticals.

A novel water-soluble near-infrared fluorescent probe named QX-P with simple synthesis is developed. QX-P has high sensitivity and selectivity to ALP. Moreover, the probe can not only visualize ALP activity in four cell lines, but also real-time image ALP activity during the diagnosis and treatment of diabetes in mice.

A porous organic polymer (marked as DT-POP), which contains abundant free phenolic hydroxyl groups, is synthesized by the well-known green azo-coupling reaction in water, characterized, and utilized as an effective adsorbent for the elimination of methylene blue (MB) from water solutions. The presence of permanent mesopores, abundant active functional groups, and π-electron enrichment ascribed to phenyl rings make DT-POP an efficient adsorbent for MB due to strong hydrogen bonding, π–π, and electrostatic interactions with the cationic dye MB. DT-POP with high stability and high adsorption capacity can be reused many times and thus shows high applicability in pollutant disposal.

The direct cross-coupling of heterocyclic phosphonium salts with aryl bromides was successfully realized by performing the reactions in THF at ambient temperature with the aid of a nickel(II) catalyst, the 1,10-phenanthroline-5,6-dione ligand, magnesium turnings, and lithium chloride, providing an easy access to 4-arylated pyridine, quinoline, quinoxaline, and pyrazine.

α-Haloboronates are useful organic synthons that can be converted to a diverse array of α-substituted alkyl borons. Methods to α-haloboronates are limiting and often suffer from harsh reaction conditions. Reported herein is a photochemical radical C-H halogenation of benzyl N-methyliminodiacetyl (MIDA) boronates. Fluorination, chlorination, and bromination reactions were effective by using this protocol. Upon reaction with different nucleophiles, the C-Br bond in the brominated product could be readily transformed to a series of C-C, C-O, C-N, C-S, C-P, and C-I bonds, some of which are difficult to forge with α-halo sp2 -B boronate esters. An activation effect of B(MIDA) moiety was found.

Cellulose nanocrystals (CNC)/poly(butylene adipate-co-butylene terephthalate) composites enhanced compatibility with phthalic anhydride were one-step prepared via melt blending. The obtained composites then underwent squeezing treatment in a two-roll milling equipment at a given temperature. CNC/PBAT composites were separated and then tested via FTIR and UV–Vis spectrophotometer. During reactive blending, phthalic anhydride selectively reacts with CNC. Before squeezing, tensile strength of CNC/PBAT composites is weakened with increasing phthalic anhydride content. After squeeze treatment at an extension ratio of 6, tensile strength of CNC/PBAT (3/97) is dramatically increased from 29.6 to 148.0 MPa, which is much higher than that of pristine PBAT 85.0 MPa. SEM and WAXD results show that PBAT crystallinity is increased after orientation, and CNC show an orientation arrangement along force direction in PBAT matrix.

Organofluorine compounds are widely used in pharmaceutical, agrochemical, and materials sciences. The syntheses and applications of fluorinated organoborons facilitate the rapid and modular assemblies of fluorine-containing molecules because of the versatility of C-B bonds in diverse chemical transformations. Reported herein is a migratory geminal difluorination of aryl-substituted alkenyl N-methyliminodiacetyl (MIDA) boronates using commercially available Py⋅HF as the fluorine source and hyperiodine as the oxidant. The protocol offers facile access to α- and β-difluorinated alkylboron compounds, both of which have previously been challenging to prepare. Mild reaction conditions, broad substrate scope, good functional-group tolerance, and moderate to good yields were observed. The utility of these products is demonstrated by further transformations of the C-B bond into other valuable functional groups.

A highly sensitive and label-free fluorescence carcinoembryonic antigen (CEA) biosensor was developed via the target-triggered enzymatic recycling amplification reaction. To design this strategy, aggregation induced emission fluorogen (AIEgen) TPE-M was chosen as a signal reporter to enhance the detection efficiency, and L-cysteine (L-Cys) was utilized as a reactant to control over the fluorescence intensity due to its distinct capability of reacting with TPE-M and hemin/G-quadruplex. CEA triggered the in-situ generation of abundant hemin/G-quadruplex through polymerase/nicking enzyme-assisted recycling amplification, and the generated hemin/G-quadruplex could catalyze destruction of L-Cys. With L-Cys consuming, a significant decrease in fluorescence intensity was observed, demonstrating that the fluorescence intensity was indirectly relied on the CEA amount. As a consequence, a facile, precise and sensitive strategy for CEA assay was readily realized. Furthermore, the detection limit was 0.033 fmol/L (S/N = 3). The developed AIEgen-based biosensor provided a new method for the sensitive and reliable detection of CEA in biological liquids, thus displaying a significant promise for the CEA-related disease diagnosis.

The Keap1 (Kelch-like ECH-associated protein 1)-Nrf2 (nuclear factor erythroid 2-related factor 2)-ARE (antioxidant response element) pathway is the major defending mechanism against oxidative stresses, and directly disrupting the Keap1-Nrf2 protein-protein interaction (PPI) has been an attractive strategy to target oxidative stress-related diseases, including cardiovascular diseases. Here, we describe the design, synthesis, and structure-activity relationships (SARs) of indoline-based compounds as potent Keap1-Nrf2 PPI inhibitors. Comprehensive SAR analysis and thermodynamics-guided optimization identified 19a as the most potent inhibitor in this series, with an IC50 of 22 nM in a competitive fluorescence polarization assay. Further evaluation indicated the proper drug-like properties of 19a. Compound 19a dose-dependently upregulated genes and protein level of Nrf2 as well as its downstream markers and showed protective effects against lipopolysaccharide-induced injury in both H9c2 cardiac cells and mouse models. Collectively, we reported here a novel indoline-based Keap1-Nrf2 PPI inhibitor as a potential cardioprotective agent.

Remote sensing techniques are widely used during petroleum exploration. However, limitations in spectral and spatial resolution mean that these techniques are used mainly to detect hydrocarbons eit...

Bismuth-contained therapies are effective in treating gastric ulcer and eliminating Helicobacter pylori (Hp). Anion polysaccharides ligand could reduce the intake of bismuth, and enhance drug efficacy of bismuth compounds. In this study, pectin-bismuth (PB) was prepared and the changes of PB structure in acidic environment were reported for the first time. The structure of PB was characterized by FT-IR, XRD, and TGA, which suggested that combined with bismuth could alter the crystal structure of pectin. XPS confirmed the ionic binding of Bi3+ with carboxyl groups of pectin. The aggregating of PB with different pH level were also investigated, and the influence of pH on PB structure were observed by SEM. Results showed that PB has much larger volume of flocculation in acidic environment compared with bismuth nitrate. Additionally, apparent shear stress (τa) of PB suspension was evaluated. These results revealed the structural characteristics and acid-induced aggregation of pectin-bismuth, and bismuth could aggregate in acidic solution with the gelation of pectin.

Allitol is a kind of rare sugar alcohol with potential application value. An engineered strain, which simultaneously expressed D-psicose-3-epimerase (DPE), ribitol dehydrogenase (RDH), and formate dehydrogenase (FDH) three enzymes, was constructed by cloning above three genes into one plasmid and transformed into the host E. coli strain, and used as the whole-cell catalysts for biotransformation of allitol from the low-cost substrate of D-fructose. The whole cell allitol biotransformation conditions were optimized. The medium, recombinant gene induction conditions, and the substrate feeding rate for cultivation of the catalytic cells were optimized. Then, the fed-batch culture was made and scaled up to 10 L fermentor. Finally, 63.44 g/L allitol was obtained from 100 g/L D-fructose after 3 h of biotransformation, and the allitol crystals of 99.9% purity were obtained by using cooling recrystallization. The allitol production method developed in this research has high product purity, and is highly efficient, easily scaled up, and suitable for large-scale production of highly purified allitol.

The dielectric properties between in-particle/water interface and bulk solution are significantly different, which are ignored in the theories of surface potential estimation. The analytical expressions of surface potential considering the dielectric saturation were derived in mixed electrolytes based on the nonlinear Poisson-Boltzmann equation. The surface potentials calculated from the approximate analytical and exact numerical solutions agreed with each other for a wide range of surface charge densities and ion concentrations. The effects of dielectric saturation became important for surface charge densities larger than 0.30 C/m \begin{document}$ ^2 $\end{document} . The analytical models of surface potential in different mixed electrolytes were valid based on original Poisson-Boltzmann equation for surface charge densities smaller than 0.30 C/m \begin{document}$ ^2 $\end{document} . The analytical model of surface potential considering the dielectric saturation for low surface charge density can return to the result of classical Poisson-Boltzmann theory. The obtained surface potential in this study can correctly predict the adsorption selectivity between monovalent and bivalent counterions.

In the past few decades, organic-inorganic hybrid metal halides acting as single-component white light emission diodes (LEDs) have attracted extensive attentions, but most of the studies concentrate on the low-dimensional lead perovskites. Here, by using the nontoxic silver as optically active metal center, a series of hybrid silver halides based on one-dimensional structures were constructed and realized broadband white light emission. Compounds [H

A novel hybrid drug nanocarrier is developed with CuCo2S4 nanoparticles as the core to be encapsulated by poly(ionic liquid) (PIL), that is, poly(tetrabutylphosphonium styrenesulfonate) (P[P4,4,4,4][SS]), as the shell. Doxorubicin (DOX) is loaded onto the PIL shell via electrostatic attraction involving amine in DOX and styrenesulfonate in PIL. pH- and thermal-responsive characteristics of P[P4,4,4,4][SS] endow the multifunctional hybrid nanocarrier system DOX-CuCo2S4@PIL with sensitive dual-stimuli-triggered drug release behaviors. The CuCo2S4 core converts near-infrared (NIR) irradiation into thermal energy to trigger the shrinkage of the PIL shell, which subsequently promotes drug release, and the pH-responsive release of DOX involves pH-sensitive electrostatic interaction of the PIL shell with DOX. A favorable controlled release of 90.5% is achieved under pH/thermo dual stimuli. In vitro experiments with MCF-7 cells well demonstrated that the drug release is controlled by the acidic intracellular environment with NIR irradiation. The CuCo2S4 core also serves as a photoacoustic (PA) imaging contrast agent, as demonstrated by in vivo treatment of the MCF-7-carrying mice.

Potassium-ion batteries (PIBs) are considered a promising alternative to lithium-ion batteries (LIBs) for next-generation energy storage due to the abundance and competitive cost of potassium resources. However, the excavation and the development of proper electrodes for PIBs are still confronted with great challenges. Herein, a self-assembled bismuth sulfide microsphere wrapped with reduced graphene oxide was fabricated to form a heterostructured Bi2S3@RGO composite via a visible-light-assisted method and served as the anode for PIBs. The as-prepared Bi2S3@RGO composite presented a high reversible specific capacity of 538 mA h g-1 at 0.2 A g-1 and superior rate capability of 237 mA h g-1 at a high current density of 2 A g-1 after 300 cycles. In particular, the high capacity could be ascribed to the synergistic effect of the conversion and alloying reactions during the electrochemical processes, which was validated by ex situ X-ray diffraction. The fabrication of a unique heterostructure combining the self-assembled Bi2S3 microspheres and flexible RGO boosted the facile charge transfer, leading to the enhanced cyclic stability and rate performance.

Luminescence of polyaromatic hydrocarbons (PAHs) is quenched easily owing to their dimerization or tightly packed structures in the crystal state. In the current work, a soft-cavity-type host assembly of 1,4-diiodotetrafluorobenzene and 4-phenylpyridine N-oxide using halogen bonds was produced, and single isolated PAH guests were encapsulated in the host cavities to form ternary host–guest cocrystals. The thickness of the host cavity was observed to vary significantly, useful for accommodating various PAHs with different sizes, and it increased from 3.3 to about 6.7 A when the guest was changed from pyrene, triphenylene, or fluoranthene to the relatively large perylene or benzo[a]anthracene molecule. The luminescence behaviors of PAHs in the ternary host–guest cocrystals originated from discrete PAH molecules and were also tuned by intermolecular interactions to a certain degree, and the materials displayed purple-pink, light-pink, jewelry-blue, yellow-green and amaranth emissions, respectively, at room temperature.

To effectively enhance the utilization of clean sunlight energy, harvesting a large percentage of near infrared (NIR) light is significant. One of the commonly used effective methods for modifying semiconductors is by co-doping upconversion materials on semiconductors to heighten the photocatalytic efficiency. In this work, Yb3+/Tm3+ co-doped InVO4 nanosheets were synthesized by a facile hydrothermal path, and the crystal phases, morphologies, surface chemical compositions, as well as optical properties were characterized. Yb3+/Tm3+ co-doped InVO4 revealed significantly enhanced photoactivity towards chromium(VI) reduction and methyl orange oxidation under visible or NIR light irradiation. Furthermore, 5YT-IV presented the highest electrocatalytic performance and photocatalytic production of H2O2 under visible light irradiation, requiring low overpotential and low Tafel slope (390 mV dec−1) for hydrogen evolution reaction than that of the bare InVO4 (731 mV dec−1), and as well improved the yield of photocatalytic H2O2 production by about 3.5 times. This was primarily ascribed to intensive light absorption resulting from the benign upconversion energy transfer of Yb3+/Tm3+ and the boosted charge separation caused by the intermediate energy states. Moreover, the presence of h+ and ˙O2− as the main oxidative species played a significant role during the photocatalytic oxidation process of methyl orange and electrons played a decisive role in Cr(VI) reduction. This study provides a promising platform for efficiently utilizing the visible-NIR energy of sunlight in the field of photocatalytic H2O2 production and for alleviating environmental pollution in future.

Hydroxyl carbon nanotubes were surface modified by acetic anhydride to reduce its polarity and then melt blended with biodegradable polyester poly(butylenesadipate-co-terephthalate) as a reinforcing filler. After surface modification, nanotubes show higher contact angle and uniformly dispersion in polymer matrix. Dynamic thermomechanical analysis was employed to investigate interfacial adhesion between nanotubes and polymer matrix, which proving that storage modulus of composites increased after adding acetic anhydride. In addition, hardness, Young’s modulus, yielding stress as well as thermal stability of composites are all elevated with the addition of acetic anhydride, which should contribute to their commercial application.

Rapid capture of 129 I with high volatility and toxicity in the environment has attracted much attention. Herein we reported a firstly synthesized nonporous material: pyridine N-oxides (NTPO and ATPO) as iodine adsorbent. Both of NTPO and ATPO exhibit remarkable performance on the adsorption of iodine in aqueous solution, vapor state and organic solvents. Upon the capture of iodine, pyridine N-oxides were transformed to binary cocrystals combined with the pyridine N-oxides and iodine which is driven by halogen bond between iodine and oxygen atoms. Moreover, pyridine N-oxides shows high chemical, thermal and moisture stability.

The selenium-pi-acid-catalysis has received increasing attention as powerful tools for olefin functionalization, but the regioselectivity is often problematic. Reported herein is a selenium-catalyzed regiocontrolled olefin transpositional chlorination and imidation reaction. The reaction outcome benefits from an allylic B(MIDA) substitution. And the stabilization of α-anion from a hemilabile B(MIDA) moiety was believed to be the key factor for selectivity. Broad substrate scope, good functional group tolerance and generally good yields were observed. The formed products were demonstrated to be valuable precursors for the synthesis a wide variety of structurally complex organoborons.

Protons (H+) in acidic soils arrest plant growth. However, the mechanisms by which plants optimize their biological processes to diminish the unfavorable effects of H+ stress remain largely unclear. Here, we showed that in the roots of Arabidopsis thaliana, the C2H2-type transcription factor STOP1 in the nucleus was enriched by low pH in a nitrate-independent manner, with the spatial expression pattern of NITRATE TRANSPORTER 1.1 (NRT1.1) established by low pH required the action of STOP1. Additionally, the nrt1.1 and stop1 mutants, as well as the nrt1.1 stop1 double mutant, had a similar hypersensitive phenotype to low pH, indicating that STOP1 and NRT1.1 function in the same pathway for H+ tolerance. Molecular assays revealed that STOP1 directly bound to the promoter of NRT1.1 to activate its transcription in response to low pH, thus upregulating its nitrate uptake. This action improved the nitrogen use efficiency (NUE) of plants and created a favorable rhizospheric pH for root growth by enhancing H+ depletion in the rhizosphere. Consequently, the constitutive expression of NRT1.1 in stop1 mutants abolished the hypersensitive phenotype to low pH. These results demonstrate that STOP1-NRT1.1 is a key module for plants to optimize NUE and ensure better plant growth in acidic media.

Cancer ranks as a leading cause of death in every country of the world. However, if they are discovered early, a lot of cancers can be prevented or cured. Discovering and monitoring cancer markers are the main methods for early diagnosis of cancer. To date, many fluorescent probes designed and used for early cancer diagnosis can only react with a single marker, which always causes insufficient accuracy in complex systems. Herein, a novel near-infrared (NIR) fluorescent probe (CyO-DNP) for the sequential detection of H2S and H+ is synthesized. In this probe, a heptamethine dye is selected as the fluorophore and a 2,4-dinitrophenyl (DNP) ether is chosen as recognition group. In the presence of H2S, CyO-DNP is transformed into CyO, which exhibits an intense fluorescence at 663 nm. Then, H+ induces the protonation of CyO to obtain CyOH, and the final fluorescence emission at 793 nm significantly enhances. Owing to the low cytotoxicity and the NIR fluorescence emission, CyO-DNP can sequentially monitor endogenous H2S and H+ in cancer cells and image exogenous and endogenous H2S and H+ in mice. It is worth mentioning that CyO-DNP can effectively avoid the false positive signal caused by the liver and kidney and discriminate normal mice and tumor mice accurately. For all we know, CyO-DNP is the first fluorescent probe for early accurate diagnosis of cancer by sequentially detecting H2S and H+.

Many G protein–coupled receptors and other signaling proteins localize to the ciliary membrane for regulating diverse cellular processes. The BBSome composed of multiple Bardet–Biedl syndrome (BBS) proteins is an intraflagellar transport (IFT) cargo adaptor essential for sorting signaling proteins in and/or out of cilia via IFT. Leucine zipper transcription factor-like 1 (LZTFL1) protein mediates ciliary signaling by controlling BBSome ciliary content, reflecting how LZTFL1 mutations could cause BBS. However, the mechanistic mechanism underlying this process remains elusive thus far. Here, we show that LZTFL1 maintains BBSome ciliary dynamics by finely controlling BBSome recruitment to the basal body and its reassembly at the ciliary tip simultaneously in Chlamydomonas reinhardtii. LZTFL1 directs BBSome recruitment to the basal body via promoting basal body targeting of Arf-like 6 GTPase BBS3, thus deciding the BBSome amount available for loading onto anterograde IFT trains for entering cilia. Meanwhile, LZTFL1 stabilizes the IFT25/27 component of the IFT-B1 subcomplex in the cell body so as to control its presence and amount at the basal body for entering cilia. Since IFT25/27 promotes BBSome reassembly at the ciliary tip for loading onto retrograde IFT trains, LZTFL1 thus also directs BBSome removal out of cilia. Therefore, LZTFL1 dysfunction deprives the BBSome of ciliary presence and generates Chlamydomonas cells defective in phototaxis. In summary, our data propose that LZTFL1 maintains BBSome dynamics in cilia by such a dual-mode system, providing insights into how LZTFL1 mediates ciliary signaling through maintaining BBSome ciliary dynamics and the pathogenetic mechanism of the BBS disorder as well.

Identifying the genes that affect cadmium (Cd) accumulation in plants is a prerequisite for minimizing dietary Cd uptake from contaminated edible parts of plants by genetic engineering. This study showed that Cd stress inhibited the expression of FERONIA (FER) gene in the roots of wild-type Arabidopsis. Knockout of FER in fer-4 mutants downregulated the Cd-induced expression of several genes related to iron (Fe) uptake, including IRT1, bHLH38, NRAMP1, NRAMP3, FRO2 andFIT. In addition, the Cd concentration in fer-4 mutant roots reduced to approximately half of that in the wild-type seedlings. As a result, the Cd tolerance of fer-4 was higher. Furthermore, increased Fe supplementation had little effect on the Cd tolerance of fer-4 mutants, but clearly improved the Cd tolerance of wild-type seedlings, showing that the alleviation of Cd toxicity by Fe depends on the action of FER. Taken together, the findings demonstrate that the knockout of FER might provide a strategy to reduce Cd contamination and improve the Cd tolerance in plants by regulating the pathways related to Fe uptake.

A near-infrared fluorescent probe, CyAc, is synthesized for accurately diagnosing cancer in vivo by sequential detection of Cys and H+. CyAc can not only discriminate normal cells and cancer cells, but also distinguish normal mice from tumor mice.

A near-infrared (NIR) fluorescence nanoprobe named RhI-DOX@ZIF-90 has been synthesized by wrapping the guest molecule (RhI and DOX) into ZIF-90 framework. The nanoprobe itself is non-fluorescent and the drug (DOX) is inactive. Upon the addition of ATP, the structure of RhI-DOX@ZIF-90 is degraded. The fluorescence of RhI is recovered and DOX is released. The nanoprobe can detect ATP with high sensitivity and selectivity. There is good linear relationship between the nanoprobe and ATP concentration from 0.25 to 10 mM and the detection limit is 0.10 mM. The nanoprobe has the ability to monitor the change of ATP level in living cells and DOX is released inducing apoptosis of cancer cells. RhI-DOX@ZIF-90 is capable of targeting mitochondria, which provides a basis for improving the efficiency of drug delivery by mitochondrial administration. In particular, the nanoprobe is preferentially accumulated in the tumor sites and detect ATP in tumor mice by fluorescence imaging using near-infrared fluorescence. At the same time, DOX can be released accurately in tumor sites and have good anti-tumor efficiency. So, this nanoprobe is a reliable tool to realize early diagnosis of cancer and improve effect of anticancer drug.

The oxidation of CoCrAlY coatings, which are prepared by atmospheric plasma spray, additionally aluminized by electric beam vacuum deposition, and finally modified by high-current pulsed electron beam irradiation, is investigated. Meanwhile, the isothermal oxidation performance of untreated coating at 1050 °C is compared to the modified coating. The surface microstructure, cross-sectional microstructure, and phase transformation of the coatings are characterized by means of scanning electron microscope and energy-dispersive spectrometry (EDS). Results reveal that the thermally grown oxide (TGO) in untreated coatings is composed of two distinct layers: a large amount of mixed gray oxides in the outer layer and a thin Al2O3 film in the inner layer. In comparison, modified coatings exhibit single TGO layer and homogeneous TGO composition. The EDS line scanning result shows that TGO is primarily comprised of α-Al2O3. These results display that the modified coatings have a much higher oxidation resistance.

To evaluate quantitative three-dimensional (3D) dynamic contrast-enhanced ultrasound (DCE-US) in the assessment of tumor angiogenesis using an orthotropic liver tumor model. Nine New Zealand white rabbits with liver orthotropic VX2 tumors were established and imaged by two-dimensional (2D) and 3D DCE-US after SonoVue® bolus injections. The intraclass correlation coefficients of perfusion parameters, including peak intensity (PI), mean transit time, time to peak, and area under the curve, were calculated based on time-intensity curve. The percentage area of microvascular (PAMV) and the expression of vascular endothelial growth factor (VEGF) were both evaluated by immunohistochemical analysis and weighted by the tumor activity area ratio. Correlations between quantitative and histologic parameters were analyzed. The reproducibility of 3D DCE-US quantitative parameters was excellent (ICC 0.91–0.99); but only PI showed high reproducibility (ICC 0.97) in 2D. None of the parameters of quantitative 2D DCE-US were significantly correlated with weighted PAMV or VEGF. For 3D DCE-US, there was a positive correlation between PI and weighted PAMV (r = 0.74, P = 0.04) as well as VEGF (r = 0.79, P = 0.02). Quantitative parameters of 3D DCE-US show feasibility, higher reproducibility and accuracy for the assessment of tumor angiogenesis using an orthotropic liver tumor model compared with 2D DCE-US.

Background The periodontal ligament is essential for homeostasis of periodontal tissue. A hypoxic milieu of the periodontal tissue is generated under periodontitis or during orthodontic treatment, which affects the periodontal and bone remodelling process. Here, we provide a comprehensive proteomic characterization of periodontal ligament cells under hypoxic conditions, aiming to reveal previously unappreciated biological changes and to help advance hypoxia-based therapeutic strategies for periodontal diseases. Methods Human periodontal ligament cells (hPDLCs) were characterized using immunohistochemistry (IHC) and flow cytometry (FACS). Successful hypoxia treatment of hPDLCs with 1% O2 was confirmed by qRT-PCR. Proliferation was evaluated using an MTT assay. The proteomic expression profile under hypoxia was studied with the isobaric tags for relative and absolute quantification (iTRAQ) approach followed by protein identification and bioinformatic analysis, and western blot verification was performed. Results The hPDLCs were positive for vimentin, CD73 and CD105 and negative for keratin, CD34 and CD45. After hypoxia treatment, the mRNA expression of hypoxia-inducible factor 1a (HIF1a) was upregulated. The proliferation rate was elevated during the first 6 h but decreased from 6 h to 72 h. A total of 220 differentially expressed proteins were quantified in hPDLCs under hypoxia (1% O2, 24 h), including 153 upregulated and 67 downregulated proteins, five of which were verified by western blot analysis. The Gene Ontology enriched terms included the energy metabolic process, membrane-bound organelle and vesicle, and protein binding terms. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis indicated several involved pathways, including glycolysis/gluconeogenesis, biosynthesis of amino acids, the HIF-1 signalling pathway, and focal adhesion. A protein–protein interaction (PPI) network demonstrated the dominant role of autophagy over apoptosis under hypoxia. Conclusion The proteomic profile of hPDLCs under hypoxia was mainly related to energy metabolism, autophagy, and responses to stimuli such as adhesion and inflammation. Previously unrecognized proteins including solute carrier family proteins, heat shock proteins, ubiquitination-related enzymes, collagen and S100 family proteins are involved in adaptive response to hypoxia in hPDLCs and are thus of great research interest in future work. Electronic supplementary material The online version of this article (10.1186/s12953-019-0151-2) contains supplementary material, which is available to authorized users.