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Graphical abstract Highlights • HCDs and OCDs were prepared simultaneously by facile one-pot hydrothermal process. • HCDs and OCDs showed bright white and blue fluorescence under UV light of 365 nm. • The HCDs were successfully used for bioimaging and biosensing of Au3+ in PC12 cells. • The HCDs could be used for fabricating the white-light-emitting devices. Abstract Hydrophilic and organophilic carbon dots (HCDs and OCDs) have been synthesized simultaneously by simple one-pot solvothermal carbonization of methylene blue and sulfuric acid using ethanol as the solvent. The synthesized HCDs and OCDs show evidently different properties, which can be respectively dissolved in distilled water and ethanol, exhibiting bright white and blue fluorescence under an UV illumination of 365 nm, and their fluorescence quantum yield reach up to 16.5% and 21.1%, respectively. The different functional groups on the surface are responsible for the distinction in fluorescence and solubility of these two kinds of carbon dots. Especially, HCDs can not only be used in visualizing detection of Au3+ in PC12 cells, but also fabricating the white-light-emitting diodes, implying their potential in exploiting low-cost CDs as replacements of phosphors for light-emitting devices. [ABSTRACT FROM AUTHOR]

In this work, an ultrasensitive fluorescence strategy on counting the degree of aggregation (DOA) of QDs aggregates was developed for Hg 2+ detection, which is based on thymine-Hg 2+ -thymine (T-Hg 2+ -T) coordination chemistry. Oligonucleotides containing 12 thymines are modified on the surface of QDs which could protect QDs effectively from aggregation in the absence of Hg 2+ . While in the presence of Hg 2+ , QDs will be made to attach with each other by the structure of “T-Hg 2+ -T” formed, and then aggregated in the sensing system. The DOA is acquired easily by recording the entire process of the blue shifting and photobleaching of QDs aggregates. First-order spectrum of each QD in the aggregates can be released from the original overlapped spectral image of the aggregates in sequence under continuous illumination because QDs exhibit the asynchronous spectra blue shifting. Employed 0.3 nM functional QDs in the sensing system, an ultralow detection limit of 4.6 pM was reached by the counting DOA-based sensing strategy. Besides, the sensor also shows high selectivity against other 12 metal ions even at high concentrations. At last, the application of the sensing strategy for river water shows that the real samples can be worked well using this method. [ABSTRACT FROM AUTHOR]

Gentamicin B and gentamicin C1a are the direct precursor for Isepamicin and Etimicin synthesis, respectively. Although producing strains have been improved for many years, both gentamicin B titer and gentamicin C1a titer in the fermentation are still low. Because all gentamicin components are biosynthesized using UDP-N-acetyl- d -glucosamine (UDP-GlcNAc) and UDP-xylose as precursors, we tried to explore strategies for development of strains capable of directing greater fluxes of these precursors into production of gentamicins. The glycosyltransferases KanM1 and GenM2, which are responsible for UDP-GlcNAc and UDP-xylose transfer, respectively, were overexpressed in gentamicin B producing strain Micromonospora echinospora JK4. It was found that gentamicin B could be improved by up to 54% with improvement of KanM1 and GenM2 expression during appropriately glucose feeding. To prove this strategy is widely usable, the KanM1 and GenM2 were also overexpressed in gentamicin C1a producing strain, titers of gentamicin C1a improved by 45% when compared with titers of the starting strain. These results demonstrated overexpression the glycosyltransferases that transfer primary metabolites into secondary metabolites is workable for improvement of gentamicins production. [ABSTRACT FROM AUTHOR]

Mechanochromism in polymers has attracted great interests in recent years. Herein, we develop a mechanochromic elastomer carrying spiropyran mechanophores in the chain and mechanoresponsiveness of elastomer is enhanced by embedding luminescent carbon dot (CD) nanoparticles as crosslinkers and energy donor in fluorescence resonance energy transfer (FRET). Compared with the control with physically blended CD , CD crosslinked elastomer exhibit excellent daylight and fluorescent colors change under stretching. The mechanochemically induced fluorescence change is a result of FRET between CD nanoparticles and the activated merocyanine. The control with physically blended CD nanoparticles shows low FRET in stretching due to lower fraction of spiropyran activation as a result of lower mechanical properties. Furthermore, the CD crosslinked elastomer has already been applied in rewritable mechanochemical and photochemical recording or printing. Our demonstration shows that interfacial chemical bonding plays a critical role in the reinforcement of mechanical properties for polymer composites and may exhibit great potential in the study of the acceleration of mechanoresponsiveness of polymer and multi-responsiveness of polymer nanocomposites. [Display omitted] • Mechanochromic elastomers were prepared with SP being in chain and crosslinked by CD. • CD as nanofiller and energy donor improves mechanochromism of nanocomposites by FRET. • Elastomers enable use in rewritable mechano- and photochemical recording/printing. [ABSTRACT FROM AUTHOR]

In this study, regularization algorithms (RR, LR, and ENR), classical ML algorithms (SVR, DT, and RF), and advanced GBM algorithms (LightGBM, CatBoost, and XGBoost) were applied to build the holocellulose content predictive models of poplar based on features extracted from Raman spectra. Evaluation results of models indicate that classical ML algorithms show higher predictive accuracy than regularization algorithms, and the advanced GBM algorithms better than the classical ML algorithms. Furthermore, models built by CatBoost and XGBoost can estimate holocellulose content with high predictive accuracy of test R2 above 0.93 and test RMSE less than 0.29%. It provides the heretofore best precision of holocellulose content predictive model based on Raman spectroscopy so far for our knowledge. Therefore, it is suggested that Raman spectroscopy coupled with ML algorithms is a promising tool for predicting the holocellulose content in poplar which can be applied in large-scale tree genetic and breeding programs. [Display omitted] • Models were developed to predict holocellulose content by machine learning algorithms. • CatBoost and XGBoost are better than other algorithms in predicting holocellulose. • A predictive model of holocellulose content with test R2 = 0.93 and RMSE = 0.28 is built. [ABSTRACT FROM AUTHOR]

Studying lignin content is critical for analyzing the inherent constitution, performance, and application of lignocellulosic materials. However, the traditional methods (wet chemical methods) for the determination of lignin content have several limitations such as labor intensive, time-consuming preparations, and the use of toxic reagents. To address these shortcomings, based on 140 groups of poplar samples, a strategy of 1064 nm FT-Raman spectroscopy combined with several algorithms was proposed in our study. Before modeling, smoothing algorithm (Savitzky-Golay), baseline correction algorithm (adaptive iteratively reweighted penalized least squares), and deconvolution algorithm (Gaussian and Lorentzian) were applied to extract the Raman information. Also, several peaks including 1095, 1378, and 2895 cm−1 were selected as the candidates of internal standard peak for normalizing the lignin-related peaks. Subsequently, lignin content predictive models were established based on data extracted from FT-Raman spectra combined with regression algorithms, including principal components regression (PCR), partial least square regression (PLSR), ridge regression (RR), lasso regression (LR), and elastic net regressions (ENR). Consequently, credible models were obtained based on data normalized by peak of 2895 cm−1 combined with RR, LR, and ENR algorithms (Pearson's R > 0.88, RMSE < 0.62, MAE < 0.46, and MAPE < 1.92%). Thus, the lignin quantitative models based on Raman spectroscopy developed here can be used to predict the lignin content in poplar clones accurately and efficiently. [Display omitted] • Predicting models of poplar lignin content were build based on FT-Raman spectroscopy. • Normalized spectra based on peak at 2895 cm−1 and RR, LR, and ENR algorithms are preferred. • Additional groups of sample and 10-fold cross validation ensure models stability and robustness. [ABSTRACT FROM AUTHOR]

[Display omitted] • A fast and accurate method for predicting lignin content of poplar is proposed. • Features extracted from Raman spectra were used for model input variables. • Random forest, LightGBM, CatBoost, and XGboost can accurately predict lignin content. • XGBoost algorithm offered the highest prediction accuracy with test R2 above 0.94. Based on features extracted from Raman spectra, regularization algorithms, SVR, DT, RF, LightGBM, CatBoost, and XGBoost were used to develop prediction models for lignin content in poplar. Firstly, Raman features extracted from FT-Raman spectra after data processing were used as input of models and determined lignin contents were output. Secondly, grid-search combined with cross-validation was used to adjust the hyper-parameters of models. Finally, the predictive models were built by aforementioned algorithms. The results indicated regularization algorithms, SVR, DT held test R2 were >0.80 which means the predictive values from model still deviate from measured ones. Meanwhile, RF, LightGBM, CatBoost, and XGBoost were better than above algorithms, and their test R2 were >0.91 which suggesting the predictive values was nearly close to measured ones. Therefore, fast and accurate methods for predicting lignin content were obtained and will be useful for screening suitable lignocellulosic resource with expected lignin content. [ABSTRACT FROM AUTHOR]

[Display omitted] • In-situ hydrothermal method with CQDs assisted was used to prepare catalyst. • Catalyst with metal particles confined into the channel of support was obtained. • Catalyst exhibits excellent thermal stability and long-term stability. Confining the active metal particles inside the channel of mesoporous support is an effective way to improve the catalytic activity and stability, as well as enhance the metal usage thus reducing the required amount of supported metal. In our research, a novel highly efficient Nickel-based catalyst with the metal particles confined in the pores of mesoporous support was obtained by in-situ hydrothermal synthesis with carbon quantum dots (CQDs) assisted. This catalyst is of scientific significance for low metal content (as low as 0.9 wt%), except for its large specific surface area, high metal dispersion and small metal particle size. And the catalyst exhibits satisfying CO methanation catalytic activity with 95% CO conversion and 90% CH 4 selectivity at 400 °C and 15000 mlg−1h−1 when the metal loading is 0.9 wt%. Meanwhile, the catalyst presents excellent thermal and long-term stability for that the metal particles are confined inside the pores of support, which could strengthen the metal-support interaction and thus inhibiting the metal agglomeration and carbon deposition effectively. [ABSTRACT FROM AUTHOR]

Raman spectroscopy is effective for studying the ultrastructure, lignin content, and cellulose crystallinity of lignocellulosic materials. However, the quantitative analysis of holocellulose in lignocellulosic materials by this technique is challenging. In this study, based on Fourier-transform Raman (FT-Raman) spectroscopy, a novel strategy for building poplar holocellulose content quantitative model was proposed. Different algorithms were applied, including Principal component regression (PCR), partial least square regression (PLSR), ridge regression (RR), lasso regression (LR), and elastic net regression (ENR). Combined with different algorithms, twelve candidates of internal standard were selected. Sixty models combined by five regression algorithms and twelve internal standards were performed by five-fold cross validation. Consequently, the models constructed through RR, LR, and ENR combined with the internal standard of peak intensity of 2945 cm−1 were credible (R p > 0.9, RMSE p < 1.0, and MAE p < 0.9). Credible models were obtained, indicating the high potential of FT-Raman spectroscopy for predicting the holocellulose content of lignocellulosic materials. [ABSTRACT FROM AUTHOR]

Abstract: Nano-sized ceramic particle reinforced aluminum matrix composites fabricated using conventional stir casting technique usually present poor distribution of nanoparticles within the matrix and high porosity. In this study, nano-Al2O3/2024 composites were prepared by solid–liquid mixed casting combined with ultrasonic treatment. The obtained composite exhibited fine grain microstructure, reasonable Al2O3 nanoparticles distribution in the matrix, and low porosity. Solid–liquid mixed casting technique was effective in inhibiting the agglomeration of nanoparticles in the matrix. The application of ultrasonic vibration on the composite melt during the solidification not only refined the grain microstructure of the matrix, but also improved the distribution of nano-sized reinforcement. Compared with the matrix, the ultimate tensile strength and yield strength of 1wt.% nano-Al2O3/2024 composite were enhanced by 37% and 81%, respectively. The better tensile properties were attributed to the uniform distribution of reinforcement and grain refinement of aluminum matrix. [Copyright &y& Elsevier]

Abstract: Phenanthroindolizidine-based tylophora alkaloids have been reported to have potential antitumor, anti-immuno and, anti-inflammatory activity. The structure–activity relationships of a series of tylophora alkaloids were studied to guide future drug design. Our results indicate that although these compounds are structural analogs, their potency of cytotoxicity, selectivity against NF-κB signaling pathway, and their inhibitory effects against protein and nucleic acid synthesis are different. Because they do not have an identical spectrum of targets, the studied compounds are structural, but may not be functional analogs. [Copyright &y& Elsevier]

Abstract: Five phenanthroindolizidine alkaloids (PA) were chemically synthesized and seven were isolated from Tylophora atrofolliculata. To facilitate future drug design of phenanthroindolizidine alkaloids as potential antitumor agents, we have explored the structure–activity relationships (SAR) of this class of compounds. We demonstrated that DCB-3503 and tylophorinidine (PA-7) were among the most active compounds against tumor growth both in vitro and in vivo. In the hepatocellular carcinoma cell line HepG2, the GI50s of DCB-3503 and PA-7 were 35±5nM and 11±5nM, respectively. DCB-3503 and PA-7 significantly inhibited HepG2 tumor growth in nude mice at a dose of 9mg/kg given by intraperitoneal (ip) injections twice a day every third day for a total of four cycles (P <0.05 for DCB-3503 and P <0.01 for PA-7). Their potent antitumor activities correlated with their potent NF-κB-inhibitory effects and their cyclin D1 down-regulatory effects. [Copyright &y& Elsevier]

• Polyols were used to pretreat the mesoporous silica molecular sieve SBA-16 to adjust the surface groups. • Bimetallic Ni-Fe catalysts with polyol-pretreated support were obtained. • The mechanism of how the polyols influence the surface SiOH groups and thus the metal particles distribution was figured out. • Catalysts with polyol-pretreated support lowered the minimum temperature for CO complete conversion to 230 °C from 290 °C. Polyols were used to pretreat the mesoporous silica molecular sieve SBA-16 and thus supported bimetallic Ni-Fe catalyst was prepared in order to address the low activity of CO methanation at lower temperature. The characterization of the pretreated support and catalysts indicated that the residual polyols release heat during combustion, which could provide energy for the decomposition of metal precursors, lowering the decomposition temperature and reducing the metal particle size. More importantly, the pretreatment of support with polyols could increase the isolated silicon hydroxyl, and strengthen the metal-support interaction, thus obtaining smaller metal particles. The smaller metal particles promoted the dissociation of reactant gas, as a result, Ni-Fe bimetallic catalyst with polyol-pretreated support could lower the minimum temperature for CO complete conversion from 290 °C to 230 °C while keeping CH 4 selectivity above 90%. Catalysts with polyol-pretreated support provide a new possibility for low-temperature CO methanation technology. [Display omitted] [ABSTRACT FROM AUTHOR]

An ultra - rapid, in-situ Raman microscopy strategy was developed for judging both seed freshness and seed vigor based on relative quantification of carotenoids content during sunflower seed germination. The carotenoids content was determined using the ratio of the Raman peak intensities at 1525 and 1268 cm−1 (I 1525/1268). When different samples (harvest times and storage conditions) were soaked in water for 0–24 h, the carotenoids content in the embryonic axes gradually increased, with the carotenoids higher in fresher seeds. Using this method, freshly harvested sunflower seeds (2022) were successfully discriminated from seeds harvested over three previous years (2019–2021) and from seeds subjected to accelerated aging at 45 °C or 60 °C for 2–8 days, the samples were correctly differentiated >90%. In addition, a linear correlation between I 1525/1268 ratio and seed germination was found (R2 > 0.95). This proposed method can serve as an ultra-rapid strategy for determination of sunflower seed quality. • An ultra - rapid, in-situ Raman microscopy strategy was developed for judging both seed freshness and seed vigor. • The method is fast, accurate and easy to operate. • A linear correlation between I 1525/1268 ratio and seed germination was found. • Carotenoid content of the germ at germination is a good indicator of sunflower seed freshness and seed vigor. [ABSTRACT FROM AUTHOR]

Abstract Aims Honokiol is a hydroxylated biphenyl natural product and displays potent antitumor activity against several cancers including prostate cancer, melanoma, leukemia, and colorectal cancer. The present study was to investigate the in vitro activity of honokiol against A549 and 95-D human lung cancer cells. Main methods A549 and 95-D cells were used with honokiol treatment. Cell viability was determined by CCK-8 assay. The cell migration and apoptosis were evaluated by wound healing assay and TUNEL staining method respectively. The expressions of ER-related proteins were analyzed by western blot and the CHOP siRNA was used to downregulate the CHOP expression. Key findings The results demonstrated that treatment of A549 and 95-D cells with honokiol significantly reduced cell viability in a dose- and time-dependent manner. Furthermore, honokiol treatment decreased cell migration and enhanced cell apoptosis, which is accompanied by the upregulation of the expressions of ER stress-induced apoptotic signaling molecules such as GRP78, phosphorylated PERK, phosphorylated eIF2α, CHOP, Bcl-2, Bax, and cleaved Caspase 9. Honokiol treatment-induced increase of ER stress-related signaling molecules and apoptotic proteins in A549 and 95-D cells were reversed by CHOP siRNA. Significance Collectively, we conclude that ER stress may participate in the action of the anticancer activity of honokiol in A549 and 95-D cells and induction of ER stress-related apoptosis may represent a novel therapeutic intervention for human lung cancer. [ABSTRACT FROM AUTHOR]

• Dynamic contact behaviors between steel wires and saddle materials (transverse slip, longitudinal deformation, contact state) were presented. • Effects of transverse and longitudinal locations, friction cycles and saddle material on dynamic contact behaviors were explored. In order to prevent skid accidents of main cable of suspension bridge, dynamic contact behaviors between saddle materials and steel wires were explored in the present study. Dynamic contact tests of saddle materials were conducted employing the self-made dynamic contact test rig. Dynamic contact behaviors of the saddle material (transverse slip, longitudinal deformation, contact state, wear mechanism) in a friction cycle were investigated. Effects of transverse and longitudinal locations, friction cycles and saddle materials on the dynamic contact behaviors were presented. The results show that dynamic contact states between saddle specimen and steel wireexhibits the adhesion-gross slip-adhesion-gross slip state in a friction cycle. The transverse slip and longitudinal deformation of saddle specimen both decrease with increasing distance to the contact interface, decrease along the transverse sliding direction, and increase with increasing friction cycles. The ZG270-480 saddle material exhibits the largest average transverse slip and longitudinal deformation, while ZG275-485 saddle material shows the smaller values. [ABSTRACT FROM AUTHOR]

The magnetization process in nanocrystalline Fe85.1Mo0.5Zr3.3Nb3.3B6.8Cu1 alloy was studied by varying the AC and/or DC magnetic field amplitude in the frequency range from 0.1 kHz to 1 MHz. When a small magnetic field is applied, the magnetization process is dominated by the domain wall bulging; and when the applied field is over the threshold field (Hp), the magnetization process is dominated by the domain wall bulging and displacement. A small longitudinally DC magnetic field will lead to an increase in the magnetization process, a high DC field produces a decrease in the magnetization process. [Copyright &y& Elsevier]

The influence of the partial substitution of Fe by Mo on the magnetic behavior and the frequency dependencies of the complex magnetic permeability are studied in Fe85.6−xMoxZr3.3Nb3.3B6.8Cu1 alloys. With the increase of the Mo content, the crystallization temperature will increase. The spectra of real and imaginary parts of the complex permeability were measured in the frequency of 0.1 kHz to 1 MHz, the obtained permeability spectra shows typical features of domain wall relaxation dispersion. With the increase of the Mo content, the core loss will decrease and the relaxation frequency will increase obviously. [Copyright &y& Elsevier]

Graphical abstract Catalysts prepared by Si-modified zirconia possess more active species and more Brönsted acid sites, which can improve CO conversion and CH 4 selectivity. Highlights • Doping of Si into ZrO 2 achieves more O defects, Brönsted acid sites and larger surface area. • More active species are obtained over catalysts with modified zirconia. • Si-modified catalysts have improved sulfur-resistant CO methanation catalytic performance. Abstract A series of Si-modified ZrO 2 supports were prepared by incorporating different content of silicon and loaded 25 wt.% MoO 3 for sulfur-resistant CO methanation reaction. The prepared catalysts were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), N 2 physisorption measurements, infrared spectra of adsorbed pyridine (Py-IR) and hydrogen temperature-programmed reduction (H 2 -TPR). The results demonstrated that Si-modified ZrO 2 achieved more stable ZrO 2 phase, more oxygen vacancies, larger specific surface area and more Brønsted acid sites. Catalysts prepared by modified ZrO 2 exhibited smaller metal particles and different interaction between metal and support, which possessed higher activity with 63.4% CO conversion and 59% CH 4 selectivity than unmodified catalyst at 550 °C under 2.5 MPa with 100 ppm H 2 S. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract A series of ZrO 2 supports were treated by ammonia solution with different reflux digestion time, and loaded 25 wt% MoO 3 for sulfur-resistant CO methanation reaction by incipient-wetness impregnation method. The MoO 3 /ZrO 2 catalysts were also characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), infrared spectra of adsorbed pyridine (Py-IR). Compared to the undigested ZrO 2 , ZrO 2 with reflux digestion in ammonia solution could achieve more oxygen vacancies, less Lewis acidic sites, smaller crystalline MoO 3 and more amount of active sites. Generally, when the support reflux digested in ammonia solution exceed 12 h, the CO conversion of digested catalysts Mo/A-ZrO 2 - x h reached 60%, while the CO conversion of undigested catalysts was just 36% at the same reaction condition. [ABSTRACT FROM AUTHOR]