Wintersweet-like Nanohybrids of Titanium-doped Cerium Vanadate Loaded with Polypyrrole for Tumor Theranostic.

Compromises between enhanced on-targeting reactivity and precise real-time monitoring in the tumor microenvironment (TME) are the main roadblocks for catalytic cancer therapy. The hallmark of a high level of hydrogen peroxide (H2O2) and acidic extracellular environment of the hypoxia solid tumor can underpin therapeutic and tracking performance. Herein, this work provides an activatable wintersweet-like nanohybrid consisting of titanium (Ti) doped cerium vanadate nanorods with the modification of polypyrrole (PPy) nanoparticles (CeVO4-Ti@PPy) for combinatorial therapies of breast carcinoma. The Ti dopants in the size-controllable CeVO4 nanorods lower the energy barrier (0.5 eV) of the rate-determining steps and elaborate peroxidase-like (POD-like) activities to improve the generation of toxic hydroxyl radical (·OH) according to the density functional theory (DFT) calculation. The multiple enzyme-like activities, including the intrinsic glutathione peroxidase (GPx) and catalase (CAT), achieve a record-high therapeutic efficiency. Coupling this oxidative stress with the photothermal effects of PPy enables enhanced catalytic tumor necrosis. The exterior PPy heterogeneous structure can be further doped with protons in the local acidic environment to intensify photoacoustic signals, allowing the non-invasive accurate tracking of tumors. The theranostic performance displayed negligible attenuated signals in near-infrared (NIR) windows. This organic-inorganic nanohybrid with a heterogeneous structure provides the potential to improve the overall outcomes of catalytic therapy.

B and N Codoped Cellulose-Supported Ag-/Bi-Doped Mo(S,O)3 Trimetallic Sulfo-Oxide Catalyst for Photocatalytic H2 Evolution Reaction and 4-Nitrophenol Reduction.

Cellulose plays a significant role in designing efficient and stable cellulose-based metallic catalysts, owing to its surface functionalities. Its hydroxyl groups are used as anchor sites for the nucleation and growth of metallic nanoparticles and, as a result, improve the stability and catalytic activity. Meanwhile, cellulose is also amenable to surface modifications to be more suitable for incorporating and stabilizing metallic nanoparticles. Herein, the Ag-/Bi-doped Mo(S,O)3 trimetallic sulfo-oxide anchored on B and N codoped cellulose (B-N-C) synthesized by a facile approach showed excellent stability and catalytic activity for PHER at 573.28 µmol/h H2 with 25 mg of catalyst under visible light, and 92.3% of the 4-nitrophenol (4-NP) reduction was achieved within 135 min by in situ-generated protons. In addition to B and N codoping, our use of the calcination method for B-N-C preparation further increases the structural disorders and defects, which act as anchoring sites for Ag-/Bi-doped Mo(S,O)3 nanoparticles. The Ag-/Bi-doped Mo(S,O)3@B-N-C surface active site also stimulates H2O molecule adsorption and activation kinetics and reduces the photogenerated charge carrier's recombination rate. The Mo4+ → Mo6+ electron hopping transport and the O 2p and Bi 6s orbital overlap facilitate the fast electron transfer by enhancing the electron's lifetime and photoinduced charge carrier mobility, respectively. In addition to acting as a support, B-N-C provides a highly conductive network that enhances charge transport, and the relocated electron in B-N-C activates the H2O molecule, which enables Ag-/Bi-doped Mo(S,O)3@B-N-C to have appreciable PHER performance.

Growth Anisotropy and Morphology Evolution of Line Defects in Monolayer MoS2 : Atomic-Level Observation, Large-Scale Statistics, and Mechanism Understanding.

Understanding the growth behavior and morphology evolution of defects in 2D transition metal dichalcogenides is significant for the performance tuning of nanoelectronic devices. Here, the low-voltage aberration-corrected transmission electron microscopy with an in situ heating holder and a fast frame rate camera to investigate the sulfur vacancy lines in monolayer MoS2 is applied. Vacancy concentration-dependent growth anisotropy is discovered, displaying first lengthening and then broadening of line defects as the vacancy densifies. With the temperature increase from 20 °C to 800 °C, the defect morphology evolves from a dense triangular network to an ultralong linear structure due to the temperature-sensitive vacancy migration process. Atomistic dynamics of line defect reconstruction on the millisecond time scale are also captured. Density functional theory calculations, Monte Carlo simulation, and configurational force analysis are implemented to understand the growth and reconstruction mechanisms at relevant time and length scales. Throughout the work, high-resolution imaging is closely combined with quantitative analysis of images involving thousands of atoms so that the atomic-level structure and the large-area statistical rules are obtained simultaneously. The work provides new ideas for balancing the accuracy and universality of discoveries in the TEM study and will be helpful to the controlled sculpture of nanomaterials.

Ultralow-resistance electrochemical capacitor for integrable line filtering.

Electrochemical capacitors are expected to replace conventional electrolytic capacitors in line filtering for integrated circuits and portable electronics1-8. However, practical implementation of electrochemical capacitors into line-filtering circuits has not yet been achieved owing to the difficulty in synergistic accomplishment of fast responses, high specific capacitance, miniaturization and circuit-compatible integration1,4,5,9-12. Here we propose an electric-field enhancement strategy to promote frequency characteristics and capacitance simultaneously. By downscaling the channel width with femtosecond-laser scribing, a miniaturized narrow-channel in-plane electrochemical capacitor shows drastically reduced ionic resistances within both the electrode material and the electrolyte, leading to an ultralow series resistance of 39 mΩ cm2 at 120 Hz. As a consequence, an ultrahigh areal capacitance of up to 5.2 mF cm-2 is achieved with a phase angle of -80° at 120 Hz, twice as large as one of the highest reported previously4,13,14, and little degradation is observed over 1,000,000 cycles. Scalable integration of this electrochemical capacitor into microcircuitry shows a high integration density of 80 cells cm-2 and on-demand customization of capacitance and voltage. In light of excellent filtering performances and circuit compatibility, this work presents an important step of line-filtering electrochemical capacitors towards practical applications in integrated circuits and flexible electronics.

Tailoring the Atomic-Local Environment of Carbon Nanotube Tips for Selective H2 O2 Electrosynthesis at High Current Densities.

The atomic-local environment of catalytically active sites plays an important role in tuning the activity of carbon-based metal-free electrocatalysts (C-MFECs). However, the rational regulation of the environment is always impeded by synthetic limitations and insufficient understanding of the formation mechanism of the catalytic sites. Herein, the possible cleavage mechanism of carbon nanotubes (CNTs) through the crossing points during ball-milling is proposed, resulting in abundant CNT tips that are more susceptible to be modified by heteroatoms, achieving precise modulation of the atomic environment at the tips. The obtained CNTs with N,S-rich tips (N,S-TCNTs) exhibit a wide potential window of 0.59 V along with H2 O2 selectivity for over 90.0%. Even using air as the O2 source, the flow cell system with N,S-TCNTs catalyst attains high H2 O2 productivity up to 30.37 mol gcat. -1  h-1 @350 mA cm-2 , superior to most reported C-MFECs. From a practical point of view, a solid electrolyzer based on N,S-TCNTs is further employed to realize the in-situ continuous generation of pure H2 O2 solution with high productivity (up to 4.35 mmol cm-2  h-1 @300 mA cm-2 ; over 300 h). The CNTs with functionalized tips hold great promise for practical applications, even beyond H2 O2 generation.

Wood identification of Cyclobalanopsis (Endl.) Oerst based on microscopic features and CTGAN-enhanced explainable machine learning models.

Introduction: Accurate and fast identification of wood at the species level is critical for protecting and conserving tree species resources. The current identification methods are inefficient, costly, and complex. Methods: A wood species identification model based on wood anatomy and using the Cyclobalanopsis genus wood cell geometric dataset was proposed. The model was enhanced by the CTGAN deep learning algorithm and used a simulated cell geometric feature dataset. The machine learning models BPNN and SVM were trained respectively for recognition of three Cyclobalanopsis species with simulated vessel cells and simulated wood fiber cells. Results: The SVM model and BPNN model achieved recognition accuracy of 96.4% and 99.6%, respectively, on the real dataset, using the CTGAN-generated vessel dataset. The BPNN model and SVM model achieved recognition accuracy of 75.5% and 77.9% on real dataset, respectively, using the CTGAN-generated wood fiber dataset. Discussion: The machine learning model trained based on the enhanced cell geometric feature data by CTGAN achieved good recognition of Cyclobalanopsis, with the SVM model having a higher prediction accuracy than BPNN. The machine learning models were interpreted based on LIME to explore how they identify tree species based on wood cell geometric features. This proposed model can be used for efficient and cost-effective identification of wood species in industrial applications.

Sulfur Substitution and Defect Engineering in an Unfavored MnMoO4 Catalyst for Efficient Hydrogen Evolution under Visible Light.

A novel and nonstoichiometric Mn1-xMo(S,O)4-y oxysulfide catalyst with oxygen vacancies and a partial Mo6+-to-Mo4+ transition after the substitution of sulfur was synthesized for an efficient photocatalytic hydrogen evolution reaction (PHER). With appropriate sulfur substitution, a MnMoO4 semiconductor with a wide band gap was converted to Mn1-xMo(S,O)4-y with a narrow gap and a suitable band position for PHER. MnMo oxysulfide of 50 mg achieved a high PHER rate of 415.8 µmol/h under visible light, an apparent quantum efficiency (AQE) of 4.31% at 420 nm, and a solar-to-hydrogen (STH) conversion efficiency of 1.28%. Oxygen vacancies (VO) surrounded by low coordination metal atoms act as active reaction sites, which strengthen water adsorption and activation. Here, we demonstrate that sulfur substitution of MnMoO4 for lowering its wide band gap can not only disturb the strict periodicity of the lattice but also the valence states of Mn and Mo for enhancing PHER via material design.

A noble bimetal oxysulfide CuVOS catalyst for highly efficient catalytic reduction of 4-nitrophenol and organic dyes.

A novel copper-vanadium bimetallic oxysulfide (CuVOS) nanoparticle catalyst was successfully synthesized by a facile method. The samples were characterized by X-ray photoelectron spectrometry (XPS), X-ray diffractometry (XRD), field-emission scanning electron microscopy (FE-SEM), UV-Vis diffuse spectroscopy (DRS), Fourier transform infrared spectroscopy (FTIR), and N2 adsorption-desorption isotherms. In order to check the catalytic efficiencies toward reduction reaction, 4-nitrophenol (4-NP) and other organic dyes such as rhodamine-B (RhB), methylene blue (MB), and methyl orange (MO) were used. The results showed that the CuVOS prepared in the presence of a suitable amount of N2H4 during the synthesis of the nanoparticles exhibited the fastest reduction capabilities by using NaBH4 as a reducing agent. It was demonstrated that a 100 mL 4-NP (20 ppm) solution was completely reduced by 5 mg CuVOS-3 within 2 min. Moreover, the complete reduction of 100 mL of MO, RhB, and MB solutions of 100 ppm was also achieved by 5 mg CuVOS-3 within 2 min, 6 min, and 5 min, respectively. Hence, the CuVOS is an efficient catalyst for reducing 4-NP and organic dyes and can have great potential for industrial application.

New Bis-Alkenoic Acid Derivatives from a Marine-Derived Fungus Fusarium solani H915.

Fusarium solani H915 is a fungus derived from mangrove sediments. From its ethyl acetate extract, a new alkenoic acid, fusaridioic acid A (1), three new bis-alkenoic acid esters, namely, fusariumester A1 (2), A2 (3) and B (4), together with three known compounds (5⁻7), were isolated. The structures of the new compounds were comprehensively characterized by high resolution electrospray ionization-mass spectrometry (HR-ESI-MS), 1D and 2D nuclear magnetic resonance (NMR). Additionally, the antifungal activities against tea pathogenic fungi Pestalotiopsis theae and Colletotrichum gloeosporioides were studied. The new compound, 4, containing a ß-lactone ring, exhibited moderate inhibitory activity against P. theae, with an MIC of 50 µg/disc. Hymeglusin (6), a typical ß-lactone antibiotic and a terpenoid alkaloid, equisetin (7), exhibited potent inhibitory activities against both fungal species. The isolated compounds were evaluated for their effects on zebrafish embryo development. Equisetin clearly imparted toxic effect on zebrafish even at low concentrations. However, none of the alkenoic acid derivatives exhibited significant toxicity to zebrafish eggs, embryos, or larvae. Thus, the ß-lactone containing alkenoic acid derivatives from F. solani H915 are low in toxicity and are potent antifungal agents against tea pathogenic fungi.

[Spectroscopic analysis of the decay resistance of wood treated with extracts from the xylem of Cinnamomum Camphora with XRD and FTIR approaches].

Four kinds of extracts from the xylem of C. Camphora, ACQ and camphor were selected to make wood preservatives for laboratory toxicity test of wood preservatives for decay fungus. The results showed that the treated blocks with 4% ACQ and 10% methanol extracts could meet the demand of degree I of preservation and showed strong resistance to brown-rot fungus at tack. The wood treated with 4% camphor extracts, 10% ethyl acetate extracts, and 10% acetone extracts reached the demand of degree II and showed moderate decay resistance. The blocks treated with 10% hot water extracts and untreated samples meet the demand of degree III. Through XRD comparison, the author was found that the preservative effects of four extracts are proportional to the degree of crystallinity. Crystallization fields 2 theta diffraction angle were ordered from larger to little as 10% hot wa-ter extracts > untreated samples > 10% acetone extracts > 10% methanol extracts > 1% ethyl acetate extracts. According to FTIR analysis, the amount of degraded cellulose and hemicellulose increased with the decline of characteristic absorption peak at 1,374, 1,160, 1,106, 1,056 and 897 cm(-1), meaning that the preservative effect of corresponding preservatives were getting worse. The peak height of characterization of lignin is higher compared to the untreated wood. I1,510/I1,738, I1,510/I1,374, l51,510/ I1,160 of the treated blocks with 10% methanol extracts and 4% ACQ are the smallest in all the treated blocks, which proved that the degradation ability of brown--rot fungus to the holocellulose is the weakest, and the wood preservative is best.

[Resolution of overlapping Raman signals based on an adaptiveI immune algorithm].

Raman spectroscopy can be used in situ real-time measurement because it's rapid, and it is helpful to real-time online monitoring of process control. With the complexity of the environment and the characteristics of Raman signal, it is hard to avoid some overlapping spectrum peaks. Based on the advantage of immune algorithm, an immune algorithm (IA) was applied to the overlapping Raman signals of aromatics. With extraction of each single Raman spectrum peak signal from the mixture signals for resolution, Results show that the method is effective to identify the overlapped Raman signal for its fast resolution and accurate quantitative determination with the relative error less than 1%. For the overlapping Raman signals with fluorescence background disturbance, we proposed an adaptive immune algorithm, which is combined with independent component analysis. It can effectively resolve the fluorescence background signal, and it provides a new way for Raman spectra analysis of complex samples.