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A high-sensitivity fiber-optic photoacoustic sensor with pressure compensation is proposed to analyze the decomposition component SO2in high-pressure gas insulation equipment. The multiple influence mechanism of pressure on photoacoustic excitation and cantilever detection has been theoretically analyzed and verified. In the high-pressure environment, the excited photoacoustic signal is enhanced, which compensates for the loss of sensitivity of the cantilever. A fiber-optic F–P cantilever is utilized to simultaneously measure static pressure and dynamic photoacoustic wave, and a spectral demodulation method based on white light interference is applied to calculate the optical path difference of the F–P interferometer (FPI). The real-time pressure is judged through the linear relationship between the average optical path difference of FPI and the pressure, which gives the proposed fiber-optic photoacoustic sensor the inherent advantages of being uncharged and resistant to electromagnetic interference. The average optical path difference of FPI is positively related to pressure, with a responsivity of 0.6 μm/atm, which is based on changes in the refractive index of gas. In the range of 1–4 atm, the SO2sensor has a higher detection sensitivity at high-pressure, which benefits from the pressure compensation effect. With the pressure environment of gas insulation equipment at 4 atm as the application background, the SO2gas is tested. The detection limit is 20 ppb with an averaging time of 400 s.

Managing Heating, Ventilation and Air-Conditioning (HVAC) optimally with respect to energy efficiency and adaptively with respect to uncertainties is a recognized bottleneck for multi-zone buildings. This work proposes a management approach where HVAC operation is approximated using averaged thermal dynamics. By doing this, energy management becomes effective due to the linear form of the averaged dynamics, making it possible to use optimal and adaptive control tools. The proposed approach exhibits favorable features for implementation in energy management programs: minimal parameters to be estimated (only those directly related to the thermal coefficients); preservation of the distributed multi-zone topology (only the thermal coefficients with neighboring rooms need to be estimated); simplicity of imposing positivity and controllability properties. Optimality and adaptation are studied analytically in the framework of adaptive linear quadratic control. Numerical validations show that the proposed approach strikes optimal trade-offs between energy consumption and thermal comfort, while handling unknown and possibly time-varying parameters. Improved trade-offs span 3-12% with respect to PID control, 14-47% with respect to non-adaptive control, and 1-20% with respect to alternative adaptation methods proposed in the literature.

Postpartum weight retention (PPWR) is a common problem among women after childbirth. The main objectives of this study are to understand the changes in body weight of breastfeeding mothers during long-term follow-up and preliminarily explore the relationship between maternal body weight and human milk composition, including macronutrients, leptin, and adiponectin. Methods: The study included a longitudinal cohort (122 mothers), and a cross-sectional cohort (37 mothers). The human milk, maternal weight, and dietary surveys were collected in the longitudinal cohort at different follow-up time points (1−14 days postpartum, 2−4 months postpartum, 5−7 months postpartum, and 12−17 months postpartum). The maternal body weight was analyzed using the responses in the survey questionnaires. A milk analyzer based on the mid-infrared spectroscopy (MIRS) was used to determine milk composition, and nutrition analysis software evaluated dietary intakes. In the cross-sectional cohort, participating mothers were asked to provide blood and human milk samples and pertinent information related to maternal body composition. Maternal body composition was measured by bioelectrical impedance analysis (BIA), while ELISA analyzed leptin and adiponectin in milk and serum. Results: At 5−7 months postpartum, the PPWR of breastfeeding mothers was (2.46 ± 3.59) kg. At 12−17 months postpartum, the PPWR was (0.98 ± 4.06) kg. PPWR was found to be negatively correlated with milk fat content within 14 days postpartum and positively correlated at 2−4 months postpartum. In addition, the maternal weight and body muscle mass were positively correlated with leptin and adiponectin in milk. Plasma leptin was positively correlated with the mother's body weight, body mass index (BMI), FAT percentage, and body fat mass, while plasma adiponectin did not correlate with any parameter. The results also indicate that the PPWR did not correlate with leptin and adiponectin in plasma or milk. Conclusions: Breastfeeding mothers may retain considerable weight gain one year after delivery. Human milk composition may be related to changes in maternal body weight. Leptin and adiponectin in breast milk and leptin in plasma are associated with the maternal body composition. This study supports the notion that maternal nutritional status may affect offspring health through lactation, and future research should focus on exploring weight management of postpartum mothers.

Multiobjective optimization problems (MOPs) with expensive constraints pose stiff challenges to existing surrogate-assisted evolutionary algorithms (SAEAs) in a very limited computational cost, due to the fact that the number of expensive constraints for an MOP is often large. For existing SAEAs, they always approximate constraint functions in a single granularity, namely, approximating the constraint violation (CV, coarse-grained) or each constraint (fine-grained). However, the landscape of CV is often too complex to be accurately approximated by a surrogate model. Although the modeling of each constraint function may be simpler than that of CV, approximating all the constraint functions independently may result in tremendous cumulative errors and high computational costs. To address this issue, in this article, we develop a multigranularity surrogate modeling framework for evolutionary algorithms (EAs), where the approximation granularity of constraint surrogates is adaptively determined by the position of the population in the fitness landscape. Moreover, a dedicated model management strategy is also developed to reduce the impact resulting from the errors introduced by constraint surrogates and prevent the population from trapping into local optima. To evaluate the performance of the proposed framework, an implementation called K-MGSAEA is proposed, and the experimental results on a large number of test problems show that the proposed framework is superior to seven state-of-the-art competitors.

Two-dimensional (2D) cell culture methods dominate the current research. However, the inherent responsiveness of cells to their native three-dimensional (3D) microenvironment necessitates a paradigm shift toward the development of advanced hydrogels that faithfully mimic the intricacies of the extracellular matrix (ECM) and enable continuous cell–ECM interactions. To address the constraints of traditional static hydrogel networks that impede effective cell–matrix and cell–cell interactions, and to tackle the inherent stability issues associated with dynamically cross-linked hydrogels, which have become a pressing concern. Herein, we present an interpenetrating polymer network (IPN) hydrogel (HA/Alg-RGD hydrogel) that combines a physically cross-linked network between alginate and calcium ions (Alg-Ca2+) for the enhanced cell growth adaptability with a chemically cross-linked hyaluronic acid (HA) network to ensure macroscopic stability during cell culture. The incorporation of arginine-glycine-aspartic peptide modified alginate (Alg-RGD) further facilitates cell adhesion and improves the cell–hydrogel interaction. Notably, this IPN hydrogel demonstrates mechanical stability and enables cell spreading and growth within its structural framework. Leveraging the reversible characteristics of the ionically cross-linked Alg-Ca2+network within IPN hydrogels, we demonstrate the feasibility of the gelatin sacrificial solution for 3D printing purposes within the hydrogel matrix. Subsequent UV-induced covalent cross-linking enables the fabrication of vascularized microfluidic channels within the resulting construct. Our results demonstrate endothelial cell spreading and spontaneous cell sprouting within the hydrogel matrix, thus highlighting the efficacy of this IPN hydrogel system in facilitating 3D cell growth. Additionally, our study emphasizes the potential of 3D printed constructs as a promising approach for vascularization in tissue engineering. The importance of RGD peptides in promoting favorable cell-hydrogel scaffold interactions is also highlighted, emphasizing their critical role in optimizing biomaterial–cell interfaces.

Developing a multifunctional hydrogel wound dressing with good injectability, self-healing, tissue adhesion, biocompatibility, and fast skin wound healing efficiency remains challenging. In this work, an injectable adhesive dopamine-functionalized oxidized hyaluronic acid/carboxymethyl chitosan/collagen (AHADA/CCS/Col) hydrogel was constructed. The Schiff dynamic bond between AHADA and CCS, the N–Ag–N bond between CCS and Ag ions, and the S–Ag–S dynamic bond between sulfhydryl-modified collagen (ColSH) and Ag ions allowed the hydrogel to be both injectable and self-healing. Moreover, the aldehyde groups and catechol groups presented in the hydrogel could generate force with several groups on the tissue interface; therefore, the hydrogel also had good tissue adhesion. In vitro experiments proved that this hydrogel exhibited good biocompatibility and could promote cell proliferation. Additionally, curcumin (Cur)-loaded gelatin nanoparticles (Cur@Gel NPs) were prepared, which could respond to matrix metalloproteinases (MMPs) and controllably release Cur to hasten wound healing efficiency. Animal experiment results showed that this AHADA/CCS/Col hydrogel loaded with Cur@Gel NPs promoted wound repairing better, indicating its potential as a wound dressing.

ABSTRACTHSPA8 (heat shock protein family A (Hsp70) member 8) plays a significant role in the autophagic degradation of proteins, however, its effect on protein stabilization and anti-bacterial autophagy remains unknown. Here, it is discovered that HSPA8, as a binding partner of RHOB and BECN1, induce autophagy for intracellular bacteria clearance. Using its NBD and LID domains, HSPA8 physically binds to RHOB residues 1–42 and 89–118 as well as to BECN1 ECD domain, preventing RHOB and BECN1 degradation. Intriguingly, HSPA8 contains predicted intrinsically disordered regions (IDRs), and drives liquid-liquid phase separation (LLPS) to concentrate RHOB and BECN1 into HSPA8-formed liquid-phase droplets, resulting in improved RHOB and BECN1 interactions. Our study reveals a novel role and mechanism of HSPA8 in modulating anti-bacterial autophagy, and highlights the effect of LLPS-related HSPA8-RHOB-BECN1 complex on enhancing protein interaction and stabilization, which improves the understanding of autophagy-mediated defense against bacteria.

Chemodynamic therapy (CDT) is a highly tumor-specific treatment, while its efficacy is compromised by the intratumoral Fenton reaction efficiency, which is determined by the following reaction factors, including the availability of Fenton ions (e.g., Fe2+), the amount of H2O2, and the degree of acidity. Synchronous optimization of these factors is a big challenge for efficient CDT. Herein, a strategy of comprehensively optimizing Fenton reaction factors was developed for traceable multistage augmented CDT by charge-reversal theranostics. The customized pH-responsive poly(ethylene)glycol-poly(β-amino esters) (PEG–PAE) micelle (PM) was prepared as the carrier. Glucose oxidase (GOx), Fe2+, and pH-responsive second near-infrared (NIR-II) LET-1052 probe were coloaded by PM to obtain the final theranostics. The activity of metastable Fe2+remained by the unsaturated coordination with PEG–PAE. Then tumor accumulation and exposure of Fe2+were achieved by charge-reversal cationization of PEG–PAE, which was further enhanced by a GOx catalysis-triggered pH decrease. Together with the abundant H2O2generation and pH decrease through GOx catalysis, the limiting factors of the Fenton reaction were comprehensively optimized, achieving the enhanced CDT both in vitroand in vivo. These findings provide a strategy for comprehensively optimizing intratumoral Fenton reaction factors to overcome the intrinsic drawbacks of current CDT.

As a type of wound dressings, adhesive hydrogel dressings have been studied widely. However, due to the problems of moisture loss and secondary damage during dressing changes, the clinical application of adhesive hydrogel dressing remains a significant challenge. Herein, we developed a water-retaining and separable adhesive hydrogel wound dressing composed of methacrylated silk fibroin (SFMA), tannic acid (TA), and urethane diacrylate (UDA). The addition of TA with an abundance of catechol groups endowed the hydrogel with improved mechanical properties, good tissue adhesion and hemostasis abilities. Then, a hydrophobic polyurethane diacrylate (PUA) coating encapsulated the hydrogel by UDA polymerization, which could maintain the long-lasting high water content of the hydrogel. Furthermore, due to the adhesion energy being higher than the fracture energy of the hydrogel, it could be separated upon peeling. Finally, the animal experiments indicated that this adhesive hemostatic hydrogel could increase wound healing efficiency by maintaining long-lasting moist environment and being changed without secondary damage. These results showed that the multifunctional hydrogel might be a promising wound dressing for clinical application.

Robot-assisted lobectomy (RAL) is increasingly used as an alternative to video-assisted lobectomy (VAL) for resectable non-small cell lung cancer (NSCLC). However, there is little evidence of any difference in postoperative health-related quality of life (HRQoL) between these two approaches.

Sparse large-scale multi-objective optimization problems (LSMOPs) widely exist in real-world applications, which have the properties of involving a large number of decision variables and sparse Pareto optimal solutions, i.e., most decision variables of these solutions are zero. In recent years, sparse LSMOPs have attracted increasing attentions in the evolutionary computation community. However, all the recently tailored algorithms for sparse LSMOPs put the sparsity detection and maintenance in the first place, where the nonzero variables can hardly be optimized sufficiently within a limited budget of function evaluations. To address this issue, this paper proposes to enhance the connection between real variables and binary variables within the two-layer encoding scheme with the assistance of variable grouping techniques. In this way, more efforts can be devoted to the real part of nonzero variables, achieving the balance between sparsity maintenance and variable optimization. According to the experimental results on eight benchmark problems and three real-world applications, the proposed algorithm is superior over existing state-of-the-art evolutionary algorithms for sparse LSMOPs.

Electronic skin (e-skin) is one of the most important components of future wearable electronic devices, whose sensing performances can be improved by constructing micropatterns on its sensitive layer. However, in traditional e-skins it is difficult to balance sensitivity and the pressure sensing range, and most micropatterns are generally prepared by some complex technologies. Herein, mushroom-mimetic micropatterns with 3D hierarchical architecture and an interdigital electrode are facilely prepared. The micropatterned sensitive layer is further developed through spraying carbon nanotube (CNT) dispersion on the thermoplastic polyurethane (TPU) film with mushroom-mimetic micropatterns (denoted as MMTC). Thanks to the “interlocking effect” between mushroom-mimetic micropatterns and the interdigital electrode in the as-prepared MMTC/interdigital electrode e-skin, the e-skin exhibits a high sensitivity (up to 600 kPa−1), a wide pressure sensing range (up to 150 kPa), a short response time (<20 ms) and excellent durability (15 000 cycles). The MMTC/interdigital electrode e-skin is capable of precisely monitoring health conditions viathe as-acquired physiological parameters in real time. Moreover, such e-skins can be used to monitor gestures wirelessly, sense the trajectory of pressure stimuli and recognize Morse code under water. This study provides a cost-efficient, facile strategy to design e-skin for future-oriented wearable intelligent systems.

Effectively reducing the voltage loss in organic solar cells (OSCs) is critical to improving the power conversion efficiency (PCE) of OSCs. In this study, highly efficient ternary OSCs were constructed by adding a non-fullerene acceptor Qx2 with a high open-circuit voltage (VOC) and low energy loss (Eloss) into PM6:m-BTP-PhC6 based binary devices. The third component Qx2 shows slightly complementary absorption with m-BTP-PhC6 and also optimizes the molecular packing, orientation, and morphology of the active layer. Moreover, the incorporation of Qx2 reduced the energetic disorder and improved the electroluminescence quantum efficiency, which suppresses the Elossand further leads to a higher VOCthan the PM6:m-BTP-PhC6 binary blend. Consequently, synergetic enhancements of VOC, short circuit current (JSC), and fill factor (FF) are realized, resulting in the PCE of 18.60%. This work shows that the selection of the appropriate third component has positive implications for reducing Elossand improving the PCE of OSCs.

Nitrogen-rich zeolitic imidazolate frameworks (ZIFs) are ideal precursors for the synthesis of metal single atoms anchored on N-doped carbon. However, the microporous structures of conventional ZIFs lead to low mass transfer efficiency and low metal utilization of their derivatives. Here, we construct a composite of Co single atoms anchored on nitrogen-doped carbon with a three-dimensional ordered macroporous structure (Co-SA/3DOM-NC) by two-step pyrolysis of ordered macro/microporous ZnCo-ZIF. Co-SA/3DOM-NC shows high activity in the oxidative esterification of furfural, achieving a 99% yield of methyl 2-furoate under mild reaction conditions, which is significantly superior to the microporous and the Co-nanoparticle counterparts. The high activity of Co-SA/3DOM-NC should be attributed to the CoN4centers with high intrinsic activity and the ordered macroporous structure, promoting the mass transfer of reactants and accessibility of active sites.Keywords: Heterogeneous catalysis; Hierarchical pores; Ordered macropore; Oxidative esterification reaction; Single-atom catalysts.

This study explored the content and change trend of osteopontin (OPN) in breast milk and analyzed the relationship between OPN in breast milk and maternal body composition.

Hydrogen sulfide (H2S) sensors are in urgent demand in the field of hermetic environment detection and metabolic disease diagnosis. However, most of the reported room-temperature (RT) H2S sensors based on transition metal oxides/salts unavoidably suffer from the poisoning effect, resulting in the unrecoverable behavior to restrain their application. Herein, copper(II) chloride-doped polyaniline emeraldine salt (PANI-CuCl2) was devised for RT-recoverable H2S detection, where the copper ion (Cu2+) was designed as a partial substitution of protons (H+) in PANI. The prepared gas sensor exhibited full recovery capability toward 0.25–10 ppm H2S, good repeatability, and long-term stability under 80% RH. Meanwhile, the changes of the PANI-CuCl2during the H2S sensing period were analyzed via multiple analytical methods to reveal the reversible sensing behavior. Results showed that doping of Cu2+not only promoted the PANI’s response through the formation of conductive copper sulfide (CuS) and following H+redoping in the PANI but also facilitated the sensor’s recovery behavior because of the Cu2+regeneration under the H+/oxygen environment. This work not only proves the changes of the interaction between the PANI and Cu2+during the H2S sensing period but also sheds light on designing recoverable H2S sensors based on transition metal salts.

Obesity is a global public health problem that endangers human health, and a rapid search for compounds with antiadipogenic activity could provide solutions to overcome this problem. Polyphenols are potential antiadipogenic compounds, but the screening strategy, structure–activity relationship (SAR), and elucidation of their mechanisms of action remain poorly understood because of the high diversity of polyphenols. Lipid rafts, enriched with sphingolipids and cholesterol, are considered a potential target of polyphenols for the regulation of cellular processes and diseases. Here, a novel rapid screening active polyphenol strategy that targets the lipid rafts using molecular dynamic simulation was developed and validated by 3T3-L1 preadipocyte assay. The screening strategy is high-throughput, inexpensive, reagent-free, and effort saving. In addition, the SAR and mechanisms of action mediating the differentiation–inhibition of the preadipocyte by polyphenols were well elucidated by utilizing multiple technologies, such as “raft-like liposomes” systems, giant plasma membrane vesicles, noninvasive lipid raft probes, and ultrahigh-resolution microscopy. High inhibitory-activity polyphenols could penetrate deeper into the hydrophobic lipid center, in an inverted V-shaped manner or by insertion of galloyl groups into rafts, thus disrupting the ordered domain of lipid rafts. In contrast, the medium and low inhibitory-activity polyphenols could only localize on the surface of lipid rafts, exerting slight and the weakest interference with a lipid raft structure, respectively. The combined use of reliable technologies could yield new knowledge on the SAR and the molecular mechanisms of polyphenols.

Supplemental Digital Content is available in the text

Controlling Heating, Ventilation and Air-Conditioning (HVAC) in a way that is both optimal (energy efficient) and adaptive (able to cope with uncertainties) is a recognized challenge in the building sector. This work presents a simple modelling approach to HVAC operation aiming for adaptive and optimal control. The proposed framework exhibits several advantages amenable for implementation in energy management systems: minimum number of parameters to be estimated; preserving the distributed nature of multiple zones in the estimation process; easiness of imposing positivity and controllability constraints on the estimated coefficients. Optimality is addressed using an adaptive linear quadratic control philosophy. Comparisons with Proportional-Integral-Derivative (PID) and non-adaptive controllers show the capability of the proposed framework of coping with uncertainty while delivering nearly optimal controls.

Hyaluronic acid (HA) based hydrogels are one of most functional natural biomaterials in the field of cartilage tissue engineering (CTE). Even with the promising advantages of HA hydrogels, the complicated mechanical properties of the native cartilage have not been realized, and fabricating HA hydrogels with excellent mechanical properties to make them practical in CTE still remains a current challenge. Here, a strategy that integrates hydrogels and nanomaterials is shown to form a HA hydrogel with sufficient mechanical loading for cartilage tissue production and recombination. Cellulose nanofibrils (CNFs) are promising nanomaterial candidates as they possess high mechanical strength and excellent biocompatibility. In this study, we developed methacrylate-functionalized CNFs that are able to photo-crosslink with methacrylated HA to fabricate HA/CNF nanocomposite hydrogels. The present composite hydrogels with a compressive modulus of 0.46 ± 0.05 MPa showed adequate compressive strength (0.198 ± 0.009 MPa) and restorability, which can be expected to employ as a stress-bearing tissue such as articular cartilage. Besides, this nanocomposite hydrogel could provide a good microenvironment for bone marrow mesenchymal stem cell proliferation, as well as chondrogenic differentiation, and exhibit prominent repair effect in the full-thickness cartilage defect model of SD rats. These results suggest that the HA/CNF nanocomposite hydrogel creates a new possibility for fabricating a scaffold in CTE.

Although targeted MAPK pathway inhibition has achieved remarkable patient responses in many cancers, the development of resistance has remained a critical challenge. Adaptive tumor response underlies the drug resistance. Furthermore, such bypass mechanisms often lead to the activation of many pro-survival kinases, which complicates the rational design of combination therapies. Here, we performed global tyrosine phosphoproteomic (pTyr) analyses and demonstrated that targeted MAPK signaling inhibition in melanoma leads to a profound remodeling of the pTyr proteome. Intriguingly, altered cholesterol metabolism might drive, in a coordinated fashion, the activation of these kinases. Indeed, we found an accumulation of intracellular cholesterol in melanoma cells (with BRAFV600Emutations) and non-small cell lung cancer cells (with KRASG12Cmutations) treated with MAPK and KRASG12Cinhibitors, respectively. Importantly, depletion of cholesterol not only prevents the feedback activation of pTyr signaling but also enhances the cytotoxic effects of MAPK pathway inhibitors, both in vitro and in vivo. Together, our findings suggest that cholesterol contributes to the tumor adaptive response upon targeted MAPK pathway inhibitors. These results also suggest that MAPK pathway inhibitors could be combined with cholesterol-lowering agents to achieve a more complete and durable response in tumors with hyperactive MAPK signaling.

Fractals are found in nature and play important roles in biological functions. However, it is challenging to controllably prepare biomolecule fractals. In this study, a series of Sierpiński triangles with global organizational chirality is successfully constructed by the coassembly of l-tryptophan and 1,3-bi(4-pyridyl)benzene molecules on Ag(111). The chirality is switched when replacing l-tryptophan by d-tryptophan. The fractal structures are characterized by low-temperature scanning tunneling microscopy at the single-molecule level. Density functional theory calculations reveal that intermolecular hydrogen bonds stabilize the Sierpiński triangles.

Surface with well-defined components and structures possesses unique electronic, magnetic, optical and chemical properties. As a result, surface chemistry research plays a crucial role in various fields such as catalysis, energy, materials, quantum, and microelectronics. Surface science mainly investigates the correspondence between surface property and functionality. Scanning probe microscopy (SPM) techniques are important tools to characterize surface properties because of the capability of atomic-scale imaging, spectroscopy and manipulation at the single-atom level. In this review, we summarize recent advances in surface electronic, magnetic and optical properties characterized mainly by SPM-based methods. We focus on elucidating the π-magnetism in graphene-based nanostructures, construction of spin qubits on surfaces, topology properties of surface organic structures, STM-based light emission, tip-enhanced Raman spectroscopy and integration of machine learning in SPM studies.

Nitrogen (N) fertilization changes both the degradation rate and chemical composition of plant litter and soil organic matter (SOM). We sought to document how N application rates and incorporation of crop straw residues in wheat-rice rotation systems are related to the chemical composition of SOM. Using Fourier transform infrared spectroscopy and 13C multiple cross-polarization/magic angle spinning nuclear magnetic resonance spectroscopy techniques, we investigated the chemical composition of SOM with incorporation of crop straw residues in a 6-year wheat-rice double-cropping system. Nitrogen fertilizer was applied at the rates of 0, 290, 380, and 470 kg N ha−1per year along with the incorporation of crop residues into the soil. We found that greater additions of N increased the concentrations of both C and N in the soil. The Fourier transform infrared spectra of SOM indicated that the abundance of aromatic functional groups (~1,628 and ~1,515 cm−1) and the amide groups (~1,660 and ~1,550 cm−1) increased in the N-amended treatments compared with the unamended treatment. 13C multiple cross-polarization/magic angle spinning nuclear magnetic resonance spectroscopy results revealed that the abundance of recalcitrant compounds, including alkyl and aromatic C, increased, whereas labile SOM components, dominated by O-alkyl and anomeric C, decreased with the elevated N application rates. These observations were also reflected in calculated indices of A/O-A aromaticity and hydrophobicity. Our results support the hypothesis that recalcitrant compounds of SOM appeared to be enhanced with the increase of the N application rates to promote crop straw decomposition in the rice-wheat rotation system.

The coordination abilities of different functional groups play fundamental roles in metal–organic frameworks. The coordination of indole-4-carboxylic acid with Fe on surfaces was investigated by scanning tunneling microscopy and density functional theory. The carboxyl group reacted with Fe atoms to form tetramers in a deprotonation process on Au(111) at room temperature. The deprotonation of pyrrolyl groups occurred at around 350 K, forming coordinated tetramer chains and rotiform structures. The arrangement of tetrameric clusters and coordination chains on Au(100) was influenced by surface reconstitution. A two-dimensional coordination network was obtained on Ag(111) without the influence of surface reconstitution.

Photon absorption-induced exciton generation plays an important role in determining the photovoltaic properties of donor/acceptor organic solar cells with an inverted architecture. However, the reconstruction of light harvesting and thus exciton generation at different locations within organic inverted device are still not well resolved. Here, we investigate the film depth-dependent light absorption spectra in a small molecule donor/acceptor film. Including depth-dependent spectra into an optical transfer matrix method allows us to reconstruct both film depth- and energy-dependent exciton generation profiles, using which short-circuit current and external quantum efficiency of the inverted device are simulated and compared with the experimental measurements. The film depth-dependent spectroscopy, from which we are able to simultaneously reconstruct light harvesting profile, depth-dependent composition distribution, and vertical energy level variations, provides insights into photovoltaic process. In combination with appropriate material processing methods and device architecture, the method proposed in this work will help optimizing film depth-dependent optical/electronic properties for high-performance solar cells.

Aiming at the problem of the fiber-optic photoacoustic (PA) sensor being easily disturbed by external vibration and noise, a differential cantilever enhanced fiber-optic PA sensor is proposed for diffusion gas detection. The sensor comprises two PA tubes with the same structure and a pair of differential interferometric cantilevers. The two PA tubes are symmetrically distributed. The laser is incident on the PA tube as the signal channel to excite the PA pressure wave. Another tube without incident laser is used as the reference channel to suppress external disturbance. The external interference signals and PA signals superimposed with disturbance are detected by the differential cantilevers from the two channels. The signals are simultaneously restored by a single white-light interferometry demodulator, which multiplexed the spectral frequency domain of the superimposed interference spectrum. The experimental results show that the suppression effect of the differential cantilever enhanced PA sensor on ambient noise is improved by 80%, compared to the traditional single-cantilever sensor. The external cofrequency disturbance is suppressed by 20.9 dB. The minimum detection limit to acetylene (C2H2) downs to about 60 ppb with an integration time of 100 s. The sensor has excellent antivibration and electromagnetic interference ability.

A self-calibration fiber-optic photoacoustic (PA) gas analyzer based on 2f/1fwavelength modulation spectroscopy (WMS) is proposed, which utilizes gas and solid multipass absorption enhancement. The laser light is incident obliquely on the cell wall, and one end of the cell is equipped with a highly reflective mirror. The gas analyzer takes full advantage of the miniature multipass PA cell, which enhances the absorption of gas and solid simultaneously. As a result, the double absorption enhancement of 1fand 2fPA signals are realized. A dual-channel lock-in white-light interferometer based on fiber-optic PA demodulation is designed to simultaneously extract the 1fand 2fPA signals detected by the silicon cantilever. The experimental results of methane gas detection show that the minimum detection limit (MDL) of the PA gas analyzer is 20 ppb when the integration time is 60 s. Moreover, the detection error of gas concentration is within 3% when the laser power is reduced by half. The fiber-optic PA gas analyzer eliminates the influence of changes in the laser power and optical path loss, which can be used for the high-precision detection of trace gases.

Surface chemistry focuses on the investigation of the adsorption, migration, assembly, activation, reaction, and desorption of atoms and molecules at surfaces. Surface chemistry plays the pivotal roles in both fundamental science and applied technology. This review will summarize the recent progresses on surface assembly, synthesis and catalysis investigated mainly by scanning tunneling microscopy and atomic force microscopy. Surface assemblies of water and small biomolecules, construction of Sierpiński triangles and surface chirality are summarized. On-surface synthesis of conjugated carbo- and heterocycles and other kinds of carbon nanostructures are surveyed. Surface model catalysis, including single-atom catalysis and electrochemical catalysis, are discussed at the single-atom level.

The stability of the shield tunneling face is an extremely important factor affecting the safety of tunnel construction. In this study, a transparent clay with properties similar to those of Tianjin clay is prepared and a new transparent clay model test apparatus is developed to overcome the “black box” problem in the traditional model test. The stability of the shield tunneling face (failure mode, influence range, support force, and surface settlement) is investigated in transparent clay under active failure. A series of transparent clay model tests is performed to investigate the active failure mode, influence range, and support force of the shield tunneling face under different burial depth conditions, whereas particle flow code three-dimensional numerical simulations are conducted to verify the failure mode of the shield tunneling face and surface settlement along the transverse section under different burial depth conditions. The results show that the engineering characteristics of transparent clay are similar to those of soft clay in Binhai, Tianjin and satisfy visibility requirements. Two types of failure modes are obtained: the overall failure mode (cover/diameter: C/D⩽ 1.0) and local failure mode (C/D⩾ 2.0). The influence range of the transverse section is wider than that of the longitudinal section when C/D⩾ 2.0. Additionally, the normalized thresholds of the relative displacement and support force ratio are 3%–6% and 0.2–0.4, respectively. Owing to the cushioning effect of the clay layer, the surface settlement is significantly reduced as the tunnel burial depth increases.

Wound healing is a complex dynamic process. During the occurrence of skin injury, the excessive reactive oxygen species (ROS) level is associated with sustained inflammatory response, which limits efficient wound repair. Although multifunctional hydrogels are considered ideal wound dressings due to their unique advantages, the development of hydrogel dressings with rapid gelling rates, shape adaptation, and antioxidant function is still a vital challenge. In this work, a ROS-responsive injectable polyethylene glycol hydrogel containing thioketal bonds (PEG-TK hydrogel) was synthesized and utilized to deliver epidermal growth factor (EGF). We adopted bio-orthogonal click chemistry for crosslinking the polymer chains to obtain the EGF@PEG-TK hydrogel with fast gelation time, injectability and shape-adaptability. More interestingly, the thioketal bonds in the PEG-TK hydrogel not only scavenged excessive ROS in the wound sites but also achieved responsive and controlled EGF release to facilitate regeneration. The EGF@PEG-TK hydrogel treatment offered the benefits of protecting cells from oxidative stress, accelerating wound closure, and reducing scar formation in the full-thickness skin defect model. This work provides a promising strategy for developing antioxidant hydrogel dressing for facilitating the repair of wounds.

Geometries of molecule-molecule interfaces strongly influence the current passing from one molecule to another. The contact conductance of molecule-molecule junctions which consist of fullerene and tin phthalocyanine molecules is investigated with a low-temperature scanning tunneling microscope. Two types of molecules are deposited onto Cu(111). Fullerene molecules are transferred to tips through controlled contact of STM tips on molecules. The molecule-molecule junctions are formed by approaching fullerene-terminated tips to tin phthalocyanine molecules on Cu(111). Our experimental method can be extended to study the intermolecular charge transport of a range of molecular junctions.

Fractals are of fundamental importance in science and technology. Theoretical simulations indicate that Sierpiński triangles (STs) possess specific optical and electronic properties. To study their properties and uncover their potential applications, it is necessary to pack STs into large-scale two-dimensional crystalline structures. Here, a series of ordered structures consisting of ST units are successfully constructed on gold surfaces through coordination between 1,3-bis(4-pyridyl) benzene molecules and Fe atoms. Crystals of STs are characterized by scanning tunneling microscopy. K-map analysis explains the structural formation mechanism, which is further verified by density functional theory calculations. The molecular free diffusion and nice structure matching between STs and gold surfaces play important roles in the formation of crystals of STs.

Wound dressings are widely used to promote wound healing. Traditional dressings need the help of tape to fix onto the wounds, which are not suitable in the human body. In addition, hemostasis of internal wounds is usually treated with direct sutures which will cause secondary trauma to the patient and increase the risk of infection. Therefore, development of new dressings with high tissue adhesion and biocompatibility is of great clinical significance. The highly adhesive wound dressings can firmly attach to external and internal wounds, and form a barrier to prevent bacterial invasion, accelerate healing, and avoid secondary damage caused by sutures. Hydrogels are soft materials that possess a 3D network structure with tunable physical and chemical properties, which provides ideal conditions to support the wound healing process. In this review, we summarize the recent advances in developing hydrogel-based wound dressings as well as their adhesion mechanism. Moreover, the prospects of these wound dressings over the coming years are also covered.

Agronomy journals form a core part of the process of scholarly communication and scientific research in the agronomic field. Determining the key features of high‐impact agronomic journals will be a central component for identifying the disciplinary development in the field of agronomy. In this study, we conducted a bibliometric study to fill this knowledge gap based on 64,703 articles published in 18 main agronomy journals since 1948 derived from the Scopus database. Our main findings were that (a) over 20% of publications in Advances in Agronomyand Agricultural and Forest Meteorologyreceived more than 50 citations; (b) authors from the United States, China, the United Kingdom, Germany, and Australia published the most articles in these journals, comprising 22.4, 11.5, 10.7, 8.7, and 8.0% of the total number of publications, respectively; and (c) journals published in a given country had a greater number of papers published by authors of that country than by authors of other countries. Furthermore, three clusters for these 18 journals were identified that included the topics of agronomy, interactions between agronomy and soil sciences, and interactions between agronomy and plant sciences. The results of this study provide valuable insights regarding the current state of and future development trends in agronomic journals.

3D bioprinting is one of the latest trends in regenerative medicine due to its capacity for constructing highly organized tissues with living cells. In this work, silk fibroin (SF) together with hydroxypropyl methyl cellulose (HPMC) was used to print bone marrow mesenchymal stem cell (BMSC)-laden double network (DN) hydrogel for cartilage tissue repair. The β-sheet structure formed among SF molecules was set as the rigid and brittle first network, while the cross-linking of HPMC-MA was set as the soft and ductile second network. Compared to the single network hydrogel, the fracture strength, breaking elongation, and compressive reproducibility increased significantly. Thereafter, the evaluation of cell proliferation and biochemical assay of this BMSC-laden 3D bioprinted hydrogel proved that it could ensure sufficient nutrient supply and great biochemical supportability in tissue engineering. This SF-based bioink with remarkable mechanical properties holds great promise as candidate for cartilage tissue regeneration.

The design and synthesis of a novel generation of a nanoscaled platform with imaging-guided therapy remain a real challenge. It can not only improve the imaging sensitivity of tumor tissues for guiding all kinds of treatments but also reduce the harm for healthy tissues. Here, polydopamine (PDA), polyethylene glycol (PEG), and c(RGDyK) peptide (RGD)-modified and cisplatin-loaded Gd2Hf2O7nanoparticles (Gd2Hf2O7@PDA@PEG-Pt-RGD NPs) are designed for magnetic resonance imaging (MRI)-guided combined chemo-/photothermal-/radiotherapy of resistant tumors. The as-prepared NPs display high relaxivity (r1= 38.28 mM–1s–1) as an MRI contrast agent because of their ultrasmall size and surface modification with polyacrylic acid and PDA. Gd2Hf2O7@PDA@PEG-Pt-RGD NPs exhibit pH and NIR dual-stimuli responsiveness for cisplatin release. Based on competent NIR absorption and high X-ray attenuation efficiency, Gd2Hf2O7@PDA@PEG-Pt-RGD NPs show potential photothermal effect by exposing to an 808 nm NIR laser and significantly improve the generation of reactive oxygen species after X-ray radiation. Combined chemo-/photothermal-/radiotherapy can effectively treat the resistant A549R cells, providing the enhanced therapeutic efficiency to cancer tissues and the reduced side effect to healthy tissues. Furthermore, Gd2Hf2O7@PDA@PEG-Pt-RGD NPs present no obvious toxicity during the treatment, which demonstrates the potential as an efficient MRI-guided combined chemo-/photothermal-/radiotherapy nanoplatform for drug-resistant tumors.

Ethylene (C2H4) is a crucial parameter to monitor due to its modulation of fruit ripening and its intrinsic significance to intelligent agriculture. In this work we present a high-performance C2H4gas sensor based on Pd-loaded SnO2, it is of potential applications in fruit quality monitoring.

The caveolin scaffolding domain peptide (CSP) is being developed for the therapeutic intervention of a lethal lung disease, idiopathic pulmonary fibrosis. While direct respiratory delivery of CSP7 (a 7-mer fragment of CSP) is considered an effective route, proper formulation and processing of the peptide are required. First, air-jet milling technology was performed in order to micronize the neat peptide powder. Next, the fine particles were subjected to a stability study with physical and chemical characterizations. In addition, the in vivoefficacy of processed CSP7 powder was evaluated in an animal model of lung fibrosis. The results revealed that, with jet milling, the particle size of CSP7 was reduced to a mass median aerodynamic diameter of 1.58 ± 0.1 μm and 93.3 ± 3.3% fine particle fraction, optimal for deep lung delivery. A statistically significant reduction of collagen was observed in diseased lung tissues of mice that received CSP7 powder for inhalation. The particles remained chemically and physically stable after micronization and during storage. This work demonstrated that jet milling is effective in the manufacturing of a stable, excipient-free CSP7 inhalation powder for the treatment of pulmonary fibrosis.

A powerful means to understand the cellular function of corrupt oncogenic signaling programs requires perturbing the system and monitoring the downstream consequences. Here, using a unique pair of non-small cell lung cancer (NSCLC)/normal lung epithelial patient-derived cell lines (HCC4017/HBEC30KT), we systematically interrogated the remodeling of the NSCLC proteome upon treatment with 35 chemical perturbagens targeting a diverse array of mechanistic classes. HCC4017 and HBEC30KT cells differ significantly in their proteomic response to the same compound treatment. Using protein covariance analyses, we identified a large number of functional protein networks. For example, we found that a poorly studied protein, C5orf22, is a novel component of the WBP11/PQBP1 splicing complex. Depletion of C5orf22 leads to the aberrant splicing and expression of genes involved in cell growth and immunomodulation. In summary, we show that by systematically measuring the tumor adaptive responses at the proteomic level, an understanding could be generated that provides critical circuit-level biological insights for these pharmacologic perturbagens.

A series of bio‐based poly(ethylene terephthalate‐co‐ethylene 2,5‐furandicarboxylate) (PEFT) fibers was prepared via the industrially feasible melt‐spinning and hot‐drawing process. The effect of 2,5‐furandicarboxylic acid (FDCA) content on the fibers properties was studied using differential scanning calorimetry, wide‐angle X‐ray diffraction, sound velocity, tensile, and boiling water shrinkage tests. It was found that the PEFT fibers showed comparable or superior tenacity to the PET fibers under the same conditions, especially the PEFT‐4 fibers exhibited the highest tenacity (2.3, 2.9 cN/dtex for the drawn PET and PEFT‐4 fibers prepared at the same take‐up speed of 2500 m/min and a fixed draw ratio of 1.6). Moreover, the boiling water shrinkage of the PEFT fibers was quite close to that of the PET fibers under the same conditions, showing that the PEFT fibers were comparable to the PET fibers in heat resistance. The results indicated that the bio‐based PEFT fibers would be a feasible alternative for the PET fibers, in terms of sustainability, processability, and mechanical properties. © 2020 Wiley Periodicals, Inc. J. Polym. Sci. 2020, 58, 320–329 A series of bio‐based PEFT fibers is fabricated via the industrially feasible melt‐spinning and hot‐drawing process and reported for the first time. Owing to the higher total molecular orientation favored by the enhanced spinline tension, the tenacity of the PEFT fibers is found close to or better than that of the PET fibers under the same conditions.

Sequence plays a crucial role in dictating the properties and applications of both natural and artificial polymers. Therefore, chemists have made great efforts to control the sequence of monomers along a polymer chain in the past decades. This focus review outlines the recent advances in sequence-controlled polymers (SCPs), mainly based upon the author’s research on constructing SCPs through maleimide chemistry, and discusses their potential applications.

The self-assembly of l-tryptophan on Cu(111) is investigated by an ultrahigh vacuum scanning tunneling microscope (STM) at 4.4 K. A series of novel supramolecular structures have been prepared with different annealing temperatures.

The self-powered strain sensors based on piezoelectric and triboelectric principles have been widely reported in flexible electronics, but they cannot achieve static strain detection. Inspired by electrochemical reactions, we propose and construct an electrochemical self-powered strain sensor for static and dynamic strain detections. Specifically, the sensor is composed of Cu/Al electrodes, elastic core-spun yarn coated with LiCl-carbon nanotubes (CNTs), and latex tube encapsulation. Among them, Cu and Al electrodes are used for electrochemical reactions; Elastic core-spun yarn endows the sensor with excellent tensile performance; LiCl provides conductive ions in electrochemical reactions; CNTs with good conductivity not only reduce the resistance between Cu and Al electrodes, but also facilitate good resistance strain effect; Latex tube encapsulation inhibits the evaporation of water molecules in the electrolyte. The strain sensing performance of the sensor is evaluated based on the current response. The results show that the sensor has wide strain detection range (2–100 %) and good repeatability (1000 times). By analyzing the strain voltage and current responses, as well as the morphology characterization of the sensor, the strain response mechanism of the sensor has been clarified, which is controlled by electrochemical reactions and resistance strain effect. The static strain monitoring function of the sensor is verified by monitoring finger bending. Combined with machine learning, the sensor can be used for respiratory behavior recognition. This work fundamentally contributes to developing self-powered strain sensor with static and dynamic strain detections.