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Abstract Nitrogen oxides (NOx) play important roles in the nitrogen cycle system and serve as renewable nitrogen sources for the synthesis of value-added chemicals driven by clean electricity. However, it is challenging to achieve selective conversion of NOx to multi-nitrogen products (e.g., N2H4) via precise construction of a single N-N bond. Herein, we propose a strategy for NOx-to-N2H4 under ambient conditions, involving electrochemical NOx upgrading to NH3, followed by ketone-mediated NH3 to N2H4. It can achieve an impressive overall NOx-to-N2H4 selectivity of 88.7%. We elucidate mechanistic insights into the ketone-mediated N-N coupling process. Diphenyl ketone (DPK) emerges as an optimal mediator, facilitating controlled N-N coupling, owing to its steric and conjugation effects. The acetonitrile solvent stabilizes and activates key imine intermediates through hydrogen bonding. Experimental results reveal that Ph2CN* intermediates formed on WO3 catalysts acted as pivotal monomers to drive controlled N-N coupling with high selectivity, facilitated by lattice-oxygen-mediated dehydrogenation. Additionally, both WO3 catalysts and DPK mediators exhibit favorable reusability, offering promise for green N2H4 synthesis.

Abstract Achieving satisfactory multi-carbon (C2+) products selectivity and current density under acidic condition is a key issue for practical application of electrochemical CO2 reduction reaction (CO2RR), but is challenging. Herein, we demonstrate that combining microenvironment modulation by porous channel structure and intrinsic catalytic activity enhancement via doping effect could promote efficient CO2RR toward C2+ products in acidic electrolyte (pH ≤ 1). The La-doped Cu hollow sphere with channels exhibits a C2+ products Faradaic efficiency (FE) of 86.2% with a partial current density of −775.8 mA cm−2. CO2 single-pass conversion efficiency for C2+ products can reach 52.8% at −900 mA cm−2. Moreover, the catalyst still maintains a high C2+ FE of 81.3% at −1 A cm−2. The channel structure plays a crucial role in accumulating K+ and OH- species near the catalyst surface and within the channels, which effectively suppresses the undesired hydrogen evolution and promotes C–C coupling. Additionally, the La doping enhances the generation of *CO intermediate, and also facilitates C2+ products formation.

Abstract Single‐atom catalysts (SACs), featuring highly uniform active sites, tunable coordination environments, and synergistic effects with support, have emerged as one of the most efficient catalysts for various reactions, particularly for electrochemical CO2 reduction (ECR). However, the scalability of SACs is restricted due to the limited choice of available support and problems that emerge when preparing SACs by thermal deposition. Here, an in situ reconstruction method for preparing SACs is developed with a variety of atomic sites, including nickel, cadmium, cobalt, and magnesium. Driven by electricity, different oxygen‐containing metal precursors, such as MOF‐74 and metal oxides, are directly atomized onto nitrogen‐doped carbon (NC) supports, yielding SACs with variable metal active sites and coordination structures. The electrochemical force facilitates the in situ generation of bonds between the metal and the supports without the need for additional complex steps. A series of MNxOy (M denotes metal) SACs on NC have been synthesized and utilized for ECR. Among these, NiNxOy SACs using Ni‐MOF‐74 as a metal precursor exhibit excellent ECR performance. This universal and general SAC synthesis strategy at room temperature is simpler than most reported synthesis methods to date, providing practical guidance for the design of the next generation of high‐performance SACs.

Traditional ventilation methods consume excessive energy but still fail to meet requirements in underground tunnel group construction. Thus, a closed-loop intelligent control system for ventilation-on-demand (VOD) was developed. To address dynamic changes in ventilation load and reduce energy consumption, firstly, the developed system calculates the real-time ventilation load and establishes a ventilation-network-based control mode to represent the ventilation system structure. The deep deterministic policy gradient (DDPG) method was then employed for the closed-loop control ensuring the required air volume in each branch of tunnel groups while minimizing energy consumption. After that, the developed closed-loop intelligent ventilation control system encompasses comprehensive perception, real analysis, real-time control, and continuous optimization. This system treats decision-making, control, and feedback as subsystems that reflect the adaptability between ventilation efficiency, construction progress, and power consumption. Finally, the end-edge-cloud-based software of the system was developed to enable remote control and display on large screens, personal computers (PCs), and mobile applications (Apps) to ensure precise and timely operation. The system was employed in tunnel group under construction at the Xulong Hydropower Station in Southwestern China, and the obtained results validate its advanced closed-loop control based on reinforcement learning (RL) and confirm its feasibility in engineering practice.

Abstract Electrocatalytic CO2 reduction is a typical reaction involving two reactants (CO2 and H2O). However, the role of H2O dissociation, which provides active *H species to multiple protonation steps, is usually overlooked. Herein, we construct a dual-active sites catalyst comprising atomic Cu sites and Cu nanoparticles supported on N-doped carbon matrix. Efficient electrosynthesis of multi-carbon products is achieved with Faradaic efficiency approaching 75.4% with a partial current density of 289.2 mA cm−2 at −0.6 V. Experimental and theoretical studies reveal that Cu nanoparticles facilitate the C-C coupling step through *CHO dimerization, while the atomic Cu sites boost H2O dissociation to form *H. The generated *H migrate to Cu nanoparticles and modulate the *H coverage on Cu NPs, and thus promote *CO-to-*CHO. The dual-active sites effect of Cu single-sites and Cu nanoparticles gives rise to the catalytic performance.

Electrocatalytic reduction of nitrite (NO2−) is a sustainable and carbon-neutral approach to producing green ammonia (NH3). We herein report the first work on building defects on PrOx for electrochemical NO2− reduction to NH3, and demonstrate a high NH3 yield of 2870 μg h−1 cm−2 at the optimal potential of –0.7 V with a faradaic efficiency (FE) of 97.6% and excellent FEs of >94% at a wide given potential range (−0.5 to −0.8 V). The kinetic isotope effect (KIE) study suggested that the reaction involved promoted hydrogenation. Theoretical calculations clarified that there was an accelerated rate-determining step of NO2− reduction on PrOx. The results also indicated that PrOx could be durable for long-term electrosynthesis and cycling tests.

A general hydrochloric acid-assistant powder-to-powder strategy was proposed for preparing a series of lead-free perovskite microcrystals, meeting the needs of rapid preparation, mass production and remarkable fluorescent performance, simultaneously.

Summary: Efficient and sustainable amino acid synthesis is essential for industrial applications. Electrocatalytic reductive amination has emerged as a promising method, but challenges such as undesired side reactions and low efficiency persist. Herein, we demonstrated a lignin-derived catalyst for alanine synthesis. Carbon nanosheets (CNSs) were synthesized from lignin via a template-assisted method and doped with nitrogen and sulfur to boost reductive amination and suppress side reactions. The resulting N,S-co-doped carbon nanosheets (NS-CNSs) exhibited outstanding electrochemical performance. It achieved a maximum alanine Faradaic efficiency of 79.5%, and a yield exceeding 1,199 μmol h−1 cm−2 on NS-CNS, with a selectivity above 99.9%. NS-CNS showed excellent durability during long-term electrolysis. Kinetic studies including control experiments and theoretical calculations provided further insights into the reaction pathway. Moreover, NS-CNS catalysts demonstrated potential in upgrading real-world polylactic acid plastic waste, yielding value-added alanine with a selectivity over 75%.

Abstract Background Grafting is one of the promising techniques for improving abiotic stress tolerance in horticultural crops, but the underlying regulatory mechanisms of drought on grafted grapevine are largely unexplored. Results Herein, we investigated the phenotypic, physiologic, biochemical, and drought related genes change of self-rooted 1103P (1103 Paulsen), SM (Shine Muscat) and grafted SM/1103P (SM shoot/1103P root) under drought stress condition. The results indicated that grafted grapevine effectively alleviated drought damage in grape leaves by higher RWC, water potential and free water content. Drought stress led to the alterations of chlorophyll, carotenoid, photosynthetic parameters and chlorophyll fluorescence in grapevine leaves after drought treatment indicated grafted plants improved the photosystem response to drought stress. Moreover, grafted plants under drought stress exhibited higher levels of abscisic acid (ABA), indoleacetic acid (IAA) and soluble protein, but less contents of hydrogen peroxide (H2O2) and malondialdehyde (MDA) both in leaves and roots. Drought stress also increased the activities of antioxidant enzymes (SOD, POD and CAT) and activated the transcript expression of VvCu/ZnSOD, VvPOD4 and VvCAT1) in both leaves and roots. Further expression analysis by real-time PCR indicated that the expression levels of ABA-dependent and ABA-independent related genes could be activated in grafted grape after drought treatment. Conclusions Taken together, our findings demonstrated that grafting onto 1103P enhanced tolerance against drought stress in grape by improving water content, photosynthesis and antioxidant defense capacity, which provided a valuable information for understanding the mechanisms of drought tolerance regulated by grafting plants.

Highly pathogenic avian influenza viruses (HPAIV), such as H5N1, H5N6, and H7N9, have been reported to frequently infect humans, but acute encephalitis caused by HPAIV in humans has been rarely reported. We report the first critical case of acute encephalitis with mild pneumonia caused by the H5N6 virus. On January 25 of 2022, a 6-year-old girl with severe neurological symptoms was admitted to our hospital and rapidly developed into seizures and coma. Brain imaging showed abnormalities. Electroencephalogram (EEG) presented abnormal slow waves. Cerebrospinal fluid (CSF) contained elevated protein (1.64 g/L) and white cells (546 × 106/L). Laboratory investigations revealed abnormally elevated transaminases, lactate dehydrogenase, and cytokines in serum. A novel reassortant H5N6 virus was identified from the patient’s serum, CSF, and tracheal aspirate specimens. Phylogenic analysis indicated that this virus was a novel reassortant avian-origin influenza A (H5N6) virus that belonged to clade 2.3.4.4b. This patient was diagnosed with acute encephalitis and discharged from the hospital accompanied by a language barrier. An epidemiological investigation confirmed that wild waterfowls were the direct source of infection in this case. Our study highlights the urgent need to pay attention to acute encephalitis caused by HPAIV.

BackgroundNuss procedure is the most common method of surgical treatment to pectus excavatum (PE). A significant percentage of surgeons choose to use thoracoscopic assistance during the Nuss procedure (TNP) to avoid cardiac injury. However, our previous findings confirm the safety of single incision Non-thoracoscopic Nuss Procedure (SINTNP). Hence, Further studies, particularly prospective randomized controlled trials, are necessary to assess the value of SINTNP for PE.MethodsThis study is a prospective, superiority, multicenter, non-masked, randomized controlled trial that investigates the outcome and hospitalization medical expense of SINTNP compared to TNP for PE. A total of 320 eligible patients according to sample size calculation by retrospective data will be randomly assigned to the SINTNP group or the TNP group at a 1:1 ratio using stratified blocked randomization and the zone length was set as four. Patients aged between 3 and 18 years old for the first surgery and without combination of complex anomalies such as Marfan syndrome and congenital heart disease will be considered for the study. The co-primary endpoint is thoracic related complications and medical expense during hospitalization. Thoracic related complications were defined as pneumothorax, pleural effusion, pneumonia and incision infection. The secondary endpoints include surgery duration and length of hospital stay.The registration number for this study protocol is ChiCTR230073081 (Chinese Clinical Trial Registry, A Primary Registry of International Clinical Trial Registry Platform, World Health Organization).

In order to quantitatively evaluate and analyze regional water resources carrying capacity (WRCC) and to describe the micro motion between connection number components, a more applicable evaluation model was sought. Firstly, an evaluation index system and grade standards for a regional WRCC were constructed. Then, a method for determining the connection number was proposed, which considered the micro motion between the connection number components in the system structure. Finally, an evaluation model based on set pair analysis (SPA) and partial connection number (PCN) that used subtraction set pair potential (SPP) to identify vulnerability factors was built, and identification results were compared with the total partial connection number (TPCN). The model was applied to Huaibei City, Anhui Province, China. The results showed that: the WRCC grade value was between 2 and 3 which was poor; the support and regulation subsystem grade value was between 2 and 3, and the pressure subsystem grade value was between 1 and 2. SPP identified that the support force and regulation force subsystem were the vulnerable subsystems. Eight indexes, including water resources per capita, rate of ecological water consumption and density of population, were the main indicators causing the poor WRCC, which were in good agreement with the local measured data. In addition, the SPP and TPCN were compared to further verify rationality of the connection number determination method and reliability of the identification results. The model established in this paper has strong applicability and can also be used for the dynamic evaluation of other resources, including the environment and ecological carrying capacity. The results in this study provide a scientific basis for water resources management and decision-making. HIGHLIGHTS Based on partial connection number, a method for calculating the connection number of a regional water resources carrying capacity (WRCC) evaluation sample was proposed.; A dynamic evaluation model of a regional WRCC was constructed based on set pair analysis and partial connection number.; Reasons for poor WRCC in Huaibei City, China are identified and results compared with local measured data.;

Metal–organic frameworks (MOFs) have broad potential applications in electrochemical glucose detection. Herein, a green ultrasonic synthesis process is presented for preparing two-dimensional (2D) copper–nickel metal–organic framework nanosheets (CuNi-MOFNs) for glucose detection. The synthesized CuNi-MOFNs were characterized using scanning electron microscopy (SEM), scanning transmission electron microscope (STEM), X-ray diffractometer (XRD), and X-ray photoelectron spectrometer (XPS). The CuNi-MOFN nanocomposites were used to cover the glassy carbon electrode (GCE) and the CuNi-MOFNs-modified electrode was studied in alkaline media. Cyclic voltammetry (CV) and amperometric i–t curves indicated that the CuNi-MOFNs-modified electrode revealed great electrochemical performances towards glucose oxidation. Due to the ease of access to active metal sites in large specific surface of nanosheets, the CuNi-MOFNs-modified electrode can effectively improve the electronic transfer rate and enhance electrocatalytic activity of the CuNi-MOFNs-modified electrode. The CuNi-MOFNs-modified electrode showed electrochemical performances for glucose detection with a linear range from 0.01 mM to 4 mM, sensitivity of 702 μAmM−1cm−2, and detection limit of 3.33 μΜ (S/N = 3). The CuNi-MOFNs-modified electrode exhibited excellent anti-interference ability and high selectivity in glucose measurements. Hence, the CuNi-MOFNs-modified electrode has good, promising prospects in non-enzymatic electrochemical glucose detection.

The assessment and diagnosis of agricultural drought vulnerability is the basis for the scientific control and prevention of agricultural drought risk. In order to quantitatively evaluate the regional agricultural drought vulnerability and effectively deal with the fuzziness and randomness between evaluation sample and evaluation grade, the entropy fuzzy pattern recognition model, which was coupled with maximum information entropy principle and fuzzy pattern recognition method, was applied to the evaluation of agricultural drought vulnerability. Furthermore, in order to find methods to reduce drought vulnerability, the subtraction set pair potential method was used to further identify the main influence factors of agricultural drought vulnerability. In addition, a case study was carried out in Bengbu City, China. The results showed that during the period from 2001 to 2010, the evaluation value of agricultural drought vulnerability in Bengbu dropped from grade IV to III, which meant that the tolerance of agricultural system to drought had been improved. Moreover, the main factors that affected the vulnerability in Bengbu were precipitation, water use efficiency and irrigation protection area rate. And the latter two were the main objects of regulation and control. Compared with the other three methods, the physical concept of drought vulnerability assessment model based on entropy fuzzy pattern recognition is more obvious, and the evaluation results are reasonable and credible. The drought vulnerability diagnosis method based on subtraction set pair potential can accurately identify key influence factor and provide measures to reduce drought vulnerability and improve drought risk management.

Drawing on social cognitive career theory, this study aims to ascertain how social creativity influences college students’ entrepreneurial intentions, based on the mediating role of career adaptability and the moderating role of parental entrepreneurial background. A total of 715 college students completed an online survey designed to collect information on these variables. SPSS (version 25.0) was used to test the model. The results indicate that after controlling for gender and individual entrepreneurial experience, college students with a high level of social creativity were likely to have a high level of entrepreneurial intention. Career adaptability partially mediates the association between social creativity and entrepreneurial intention. Moreover, both direct and indirect associations between social creativity and entrepreneurial intention were moderated by parental entrepreneurial background. Specifically, compared with college students whose parents had no entrepreneurial background, the relationships between social creativity and entrepreneurial intention, social creativity and career adaptability, and career adaptability and entrepreneurial intention were stronger among college students whose parents had an entrepreneurial background. The findings help to develop promotion programs that are more suitable for college students’ entrepreneurship intentions.

Construction of an integrated drought index is a fundamental task to conducting drought disaster risk management and developing drought resistance planning strategies. Given the evident non-consistent features during the drought evolution process, firstly, the GAMLSS approach was utilized to construct multiple combination scenarios of time-variant parameters and corresponding probability distribution functions. Then, the time-variant comprehensive drought index integrating the variable characteristics of precipitation and soil moisture was established by means of the copula function. Finally, the reliability of the time-variant comprehensive drought index was verified through its application in frequency analysis and return period determination of drought hazard system in Huaibei Plain, China. The application results demonstrated that: (1) The variation of the time-variant integrated drought indicator presented strong consistency with both soil moisture and precipitation during historical years in Huaibei Plain. (2) The overall variation of the drought hazard system characterized by drought duration and severity presented a gradual mitigation trend from west to east and north to south in Huaibei Plain, which agrees with the geographic differences and water resources availability distribution features. (3) Drought recognition results, including the frequency of drought events and typical drought processes with extreme grades, are in agreement with the practical statistics and observed data series. On the whole, the proposed time-variant integrated drought indicator is capable of extracting complex variation characteristics within the drought hazard evolution process, and can be further applied in drought monitoring, recognition and assessment research fields.

In order to effectively deal with the uncertainty between evaluation samples and evaluation criteria, and quantitatively identify the water resources carrying capacity (WRCC) and its obstacle factors in the Yellow River irrigation district, a calculation method of dynamic difference degree coefficient varying with evaluation sample was proposed, and then an evaluation and diagnosis model of WRCC was established. The results applied to the Dagong irrigation district showed that the overall WRCC of five counties in the irrigation district were improved from 2010 to 2017, especially since 2013. The improvement magnitudes of Changyuan County, Fengqiu County, and Hua County were significantly higher than those of Xun County and Neihuang County. In 2017, Fengqiu County, Changyuan County, Hua County, Xun County, and Neihuang County were in water resources critical overloaded status, and the connection number values were 0.231, 0.163, 0.120, −0.293, and −0.331, respectively, which is consistent with the fact that their distances become farther from the main stream of the Yellow River. In addition, the utilization ratio of water resources, available water resources amount per capita, GDP per capita, and water deficient ratio in each county belonged to the middle or strong obstacle index over a long period of time. They were the crucial obstacle factors of WRCC in the Dagong irrigation district, as well as the core and difficult points of water resources management. In some counties, the effective irrigation area ratio, effective utilization coefficient of irrigation water, and water consumption ratio of the ecological environment gradually developed from strong obstacle to weak or strong promotion index. These were important reasons for the improvement of their carrying situation, reflecting their control of agricultural and ecological water consumption. In short, the results of the case study suggest that the model established in this study is conducive to the identification of water resources’ carrying status and its key obstacle factors in the Yellow River irrigation district, and can be applied to the evaluation and regulation of resources and environment carrying capacity.

Pulmonary artery dissection (PAD) is a rare disease. This article reports the treatment of PAD in young infants for the first time. Both cases of the infants were treated with surgery. Different surgical methods achieve different results, which provide ideas for treating PAD in young infants.

Currently, patients with esophageal cancer, especially advanced patients, usually use autologous tissue for esophageal alternative therapy. However, an alternative therapy is often accompanied by serious complications such as ischemia and leakage, which seriously affect the prognosis of patients. Tissue engineering has been widely studied as one of the ideal methods for the treatment of esophageal cancer. In view of the complex multi-layer structure of the natural esophagus, how to use the tissue engineering method to design the scaffold with structure and function matching with the natural tissue is the principle that the tissue engineering method must follow. This article will analyze and summarize the construction methods, with or without cells, and repair effects of single-layer scaffold and multi-layer scaffold. Especially in the repair of full-thickness and circumferential esophageal defects, the flexible design method and the binding force between the layers of the scaffold are very important. In short, esophageal tissue engineering technology has broad prospects and plays a more and more important role in the treatment of esophageal diseases.

With the rapid economic development and the acceleration of urbanization, the pressure on the water resources system is becoming intense. As an important indicator of water resources security and sustainable development, the water resources carrying capacity has become a hot issue. To overcome the limitation of commonly used methods for weight determination and to evaluate the regional water resources carrying capacity reasonably, the index weight determined by the Analytic Hierarchy Process method was revised by the subtraction set pair potential to calculate the dynamic index weight. Then, the dynamic weight was combined with the set pair analysis method to evaluate the regional water resources carrying capacity dynamically. In addition, the Dagum Gini coefficient and its decomposition method were used to analyze the overall difference of water resources carrying capacity in the whole region and the differences within and between subregions considering the lack of quantitative research in spatial equilibrium. Finally, a case study was carried out in Anhui Province, China. The results showed that from 2011 to 2018, most of the water resources carrying capacity for 16 cities in Anhui Province were in a critical state, with the strongest in the south of Anhui Province and the weakest in the north. The overall spatial difference of carrying capacity in Anhui Province showed an increasing trend from 2011 to 2018. Furthermore, the slightest difference within the subregion was in the north of Anhui Province, while the largest was in the south. The most significant difference between the subregions was between the south and the north of Anhui Province. The primary source of carrying capacity spatial difference in Anhui Province was from the difference between subregions. The results of the case study suggested that the method proposed in this paper are conducive to the early find of possible disadvantages of spatial equilibrium and can effectively identify the main source of regional spatial difference in water resources carrying capacity, which means that the method can be widely applied to similar issues.

In 2.2Cr-1Mo-0.25V bainitic steels, the effect of the initial microstructure on carbide precipitation has not yet been elucidated. Therefore, in this work, the effect of normalizing temperature on the microstructure evolution and corresponding high-temperature strength change of bainitic steels was investigated by transmission electron microscopy (TEM) and scanning electron microscopy (SEM) using extra-thick hydrogenation reactor steel as the assessed material, and the precipitation strengthening mechanism was discussed. When the normalizing temperature increased from 900 °C to 990 °C, the high-temperature yield strength increased from 451 to 475 MPa and the average absorbed Charpy impact energy at −30 °C decreased from 93 to 41 J. Therefore, the optimal normalizing temperature was 960 °C. The volume fraction of MC carbides with almost no change in average diameter increased from 0.21% to 0.44%, and the dispersed strengthening of carbide was significantly enhanced. The increase in normalizing temperature increased the solid solution of alloying elements within the bainite matrix, which increased the precipitation of MC carbides during the tempering process. In addition, the lamellar M-A constituents in the initial microstructure decomposed to form MC carbides.

Currently, the implementation of water resource spatial equilibrium strategy is a fundamental policy of water resource integrated management in China; it is also a considerable challenge to explore the relationship structure features of water resources, society, economy and ecological environment (WSEE) complex system. For this purpose, firstly, we applied information entropy, ordered degree and connection number coupling method to reveal the membership characteristics between different evaluation indicators and grade criterion. Secondly, the system dynamics approach was introduced to describe the relationship features among different equilibrium subsystems. Finally, the ordered degree, connection number, information entropy and system dynamics integrated model was established to conduct relationship structure simulation and evolution trend evaluation of the WSEE system. The application results in Hefei city, Anhui Province, China, demonstrated that: (1) the variation of overall equilibrium conditions of WSEE system in Hefei city, 2020–2029 was higher compared to that of 2010–2019, though the increasing rate of ordered degree and connection number entropy (ODCNE) became slower after 2019; and (2) the annual ODCNE value from 2020 to 2029 of WSEE system under dry year scenarios increased about 0.0812, which indicated that the construction of Yangtze-Huaihe Diversion (YHD) project could play significant positive role in mitigating the equilibrium situation of WSEE system in Hefei city in the future. On the whole, this study is capable of providing the guidance basis for constructing a theoretical framework of structure simulation and equilibrium evaluation analysis of WSEE complex system.

MXene materials have the metallic conductivity of transition metal carbides. Among them, Ti3C2TX with an accordion structure has great application prospects in the field of wearable devices. However, flexible wearable electronic devices face the problem of single function in practical application. Therefore, it is particularly important to study a flexible sensor with multiple functions for electronic skin. In this work, the near-field electrohydrodynamic printing (NFEP) method was proposed to prepare the composite thin film with a micro/nanofiber structure on the flexible substrate using a solution of poly(vinylidene fluoride)/MXene nanosheet/reduced graphene oxide (PMR) nanocomposites as the printing solution. A dual-mode flexible sensor for electronic skin based on the PMR nanocomposite thin film was fabricated. The flexible sensor had the detection capability of the piezoresistive mode and the piezoelectric mode. In the piezoresistive mode, the sensitivity was 29.27 kPa−1 and the response/recovery time was 36/55 ms. In the piezoelectric mode, the sensitivity was 8.84 kPa−1 and the response time was 18.2 ms. Under the synergy of the dual modes, functions that cannot be achieved by a single mode sensor can be accomplished. In the process of detecting the pressure or deformation of the object, more information is obtained, which broadens the application range of the flexible sensor. The experimental results show that the dual-mode flexible sensor has great potential in human motion monitoring and wearable electronic device applications.

In the process of fabricating micro-patterns using the near-field electrohydrodynamic (EHD) direct-writing technology, the voltage error and the dynamic responsiveness of applied voltage have an effect on the jetting shape and the direct-writing pattern. To solve these problems, an iterative control method was proposed to compensate the voltage error between the expected voltage and the actual voltage of the near-field EHD direct-writing setup, which was controlled by the idea of iteration, and a control method based on feedforward and feedback was proposed to enhance the dynamic response of applied voltage in the process of the near-field EHD direct-writing micro-pattern, which was controlled by the idea of the feedforward and feedback. Software algorithms of the voltage error compensation and improved dynamic response of applied voltage were implemented in the near-field EHD direct-writing setup. The experimental results show that the proposed method of voltage error compensation can effectively improve the precision of applied voltage and the presented control method of improving dynamic response capability can effectively shorten the delay time of applied voltage. Finally, two groups of contrast experiments were carried out in the near-field EHD direct-writing equipment, and the experimental results demonstrate that the proposed control methods can effectively improve the jetting shape and the quality of the direct-writing micro-pattern.

Abstract Background Biological routes for utilizing both carbohydrates and lignin are important to reach the ultimate goal of bioconversion of full carbon in biomass into biofuels and biochemicals. Recent biotechnology advances have shown promises toward facilitating biological transformation of lignin into lipids. Natural and engineered Rhodococcus strains (e.g., R. opacus PD630, R. jostii RHA1, and R. jostii RHA1 VanA−) have been demonstrated to utilize lignin for lipid production, and co-culture of them can promote lipid production from lignin. Results In this study, a co-fermentation module of natural and engineered Rhodococcus strains with significant improved lignin degradation and/or lipid biosynthesis capacities was established, which enabled simultaneous conversion of glucose, lignin, and its derivatives into lipids. Although Rhodococci sp. showed preference to glucose over lignin, nearly half of the lignin was quickly depolymerized to monomers by these strains for cell growth and lipid synthesis after glucose was nearly consumed up. Profiles of metabolites produced by Rhodococcus strains growing on different carbon sources (e.g., glucose, alkali lignin, and dilute acid flowthrough-pretreated poplar wood slurry) confirmed lignin conversion during co-fermentation, and indicated novel metabolic capacities and unexplored metabolic pathways in these organisms. Proteome profiles suggested that lignin depolymerization by Rhodococci sp. involved multiple peroxidases with accessory oxidases. Besides the β-ketoadipate pathway, the phenylacetic acid (PAA) pathway was another potential route for the in vivo ring cleavage activity. In addition, deficiency of reducing power and cellular oxidative stress probably led to lower lipid production using lignin as the sole carbon source than that using glucose. Conclusions This work demonstrated a potential strategy for efficient bioconversion of both lignin and glucose into lipids by co-culture of multiple natural and engineered Rhodococcus strains. In addition, the involvement of PAA pathway in lignin degradation can help to further improve lignin utilization, and the combinatory proteomics and bioinformatics strategies used in this study can also be applied into other systems to reveal the metabolic and regulatory pathways for balanced cellular metabolism and to select genetic targets for efficient conversion of both lignin and carbohydrates into biofuels.

To promote the application of entropy concepts in uncertainty analysis of water resources complex system, a quantitative evaluation and obstacle factor diagnosis model of agricultural drought disaster risk was proposed using connection number and information entropy. The results applied to Suzhou City showed that the agricultural drought disaster risks in Suzhou during 2007–2017 were all in middle-risk status, while it presented a decreasing trend from 2010. The information entropy values of the difference degree item bI were markedly lower than those of the difference degree b, indicating that bI provided more information in the evaluation process. Furthermore, the status of drought damage sensitivity and drought hazard were improved significantly. Nevertheless, high exposure to drought and weak drought resistance capacity seriously impeded the reduction of risk. Thus, the key to decreasing risk was to maintain the level of damage sensitivity, while the difficulties were to reduce exposure and enhance resistance. In addition, the percentage of the agricultural population, population density, and percentage of effective irrigation area were the main obstacle factors of risk and also the key points of risk control in Suzhou. In short, the results suggest that the evaluation and diagnosis method is effective and conducive to regional drought disaster risk management.

Andrographolide, which is enriched in the leaves of Andrographis paniculata, has been known as “natural antibiotic” due to its pharmacological activities such as anti-inflammatory, antimicrobial and antioxidant effects. Several key enzymes in andrographolide biosynthetic pathway have been studied since the genome sequences were released, but its regulatory mechanism remains unknown. WRKY transcription factors proteins have been reported to regulate plant secondary metabolism, development as well as biotic and abiotic stresses. Here, WRKY transcription factors related to andrographolide biosynthesis were systematically identified, including sequences alignment, phylogenetic analysis, chromosomal distribution, gene structure, conserved motifs, synteny, alternative splicing event and Gene ontology (GO) annotation. A total of 58 WRKYs were identified in Chuanxinlian genome and phylogenetically classified into three groups. Moreover, nine WRKY genes underwent alternative splicing events. Furthermore, the combination of binding site prediction, gene-specific expression patterns, and phylogenetic analysis suggested that 7 WRKYs (ApWRKY01, ApWRKY08, ApWRKY12, ApWRKY14, ApWRKY19, ApWRKY20, and ApWRKY50) might regulate andrographolide biosynthesis. This study laid a foundation for understanding the regulatory mechanism of andrographolide biosynthesis and the improvement and breeding of Andrographis paniculata varieties.

Hydrological variable frequency analysis is a fundamental task for water resource management and water conservancy project design. Given the deficiencies of higher distribution features for the upper tail section of hydrological variable frequency curves and the corresponding safer resulting design of water conservancy projects utilizing the empirical frequency formula and Pearson type III function-based curve fitting method, the normal cloud transform algorithm-based model for hydrological variable frequency analysis was proposed through estimation of the sample empirical frequency by the normal cloud transform algorithm, and determining the cumulative probability distribution curve by overlapping calculation of multiple conceptual cloud distribution patterns, which is also the primary innovation of the paper. Its application result in northern Anhui province, China indicated that the varying trend of the cumulative probability distribution curve of annual precipitation derived from the proposed approach was basically consistent with the result obtained through the traditional empirical frequency formula. Furthermore, the upper tail section of the annual precipitation frequency curve derived from the cloud transform algorithm varied below the calculation result utilizing the traditional empirical frequency formula, which indicated that the annual precipitation frequency calculation result utilizing the cloud transform algorithm was more optimal compared to the results obtained by the traditional empirical frequency formula. Therefore, the proposed cloud transform algorithm-based model was reliable and effective for hydrological variable frequency analysis, which can be further applied in the related research field of hydrological process analysis.

Dopamine (DA) is an important catecholamine neurotransmitter that plays a highly relevant role in regulating the central nervous system, and abnormal DA content can cause many immune-related diseases. Hence, it is of significance to sensitively and specifically identify DA for clinical medicine. In this work, Pt/NH2-MIL-101 hybrid nanozymes with bimetallic catalytic centers were fabricated by forming coordinate bonds between Pt nanoparticles (Pt NPs) and –NH2 on metal–organic frameworks (MOF). The catalytic activity of Pt/NH2-MIL-101 was increased by 1.5 times via enlarging the exposure of more active sites and improving the activity of the active sites through the strategy of forming bimetallic catalytic centers. In the presence of DA, competing with 3, 3′, 5, 5′-tetramethylbenzidine (TMB) for the generated hydroxyl radicals (•OH), the blue oxidation state TMB (Ox-TMB) is reduced to colorless TMB, showing dramatic color changes. The Pt/NH2-MIL-101-based colorimetric assay enables the sensitive and robust detection of DA molecules with a detection limit of only 0.42 μM and has an observable potential in clinical applications.

The development of nanomaterials for imaging and drug delivery has been of great interest to the field. Here, the authors synthesized multifunctional enzyme-responsive hydrogels with self-assembling quantum dots for nucleic acid and drug delivery as well as having imaging capability.

Controllable regulation of cell behavior is one of the most important factors conducive to the restoration of tissue functions. Recently, various strategies have been developed using physical or chemical cues. Although these techniques are effective, the high cost and complex fabrication procedures impede their application. In this study, we used a low cost and simple strategy to fabricate PVA/silk fibroin composite hydrogels using a cyclic freeze-thaw method. With the increase of freeze-thaw cycles, the pore size of hydrogels decreased, the elastic modulus increased, and the swelling rate decreased. Furthermore, we chose two shapes of model cells, a spindle using bone marrow mesenchymal stem cells and smooth muscle cells, and a round shape using BV2 microglial cells. PVA/silk fibroin composite hydrogels inhibited the adhesion and proliferation of stem cells and muscle cells and changed their cell shape from spindle to round, maintained the initial round shape of BV2 microglial cells, and promoted the proliferation of BV2 microglial cells. These results demonstrate that PVA/silk fibroin composite hydrogels can be used as a novel hydrogel system to regulate cell behavior.

Graphs are often used to describe the structure of compounds and drugs. Each vertex in the graph represents the molecule and each edge represents the bond between the atoms. The resistance distance between any two vertices is equal to the resistance between the two points of an electrical network. The Resistance-Harary index is defined as the sum of reciprocals of resistance distances between all pairs of vertices. In this paper, the extremal graphs with maximum Resistance-Harary index are determined in connected graphs with given vertices and cut edges.

A micro pattern is a key component of various functional devices. In the present study, using the poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) mixed material as the direct-writing solution and photographic paper as the flexible insulating substrate, the organic micro patterns of various shapes, such as the curve of the second-order self-similar structure, the helical curve, and the wave curve, were fabricated on the flexible insulating substrate by using the near-field electrohydrodynamic direct-writing method. The effects of process parameters, such as the applied voltage, direct-writing height, flow rate of the injection system, and moving velocity of the substrate, on the width and the conductivity of the organic micro patterns were studied in the near-field electrohydrodynamic direct-writing process. The results show that the width of an organic micro pattern increases with the increase of the applied voltage of the high-voltage power supplier and the flow rate of the injection system under the condition where the three other process parameters remained constant, respectively, while the width of an organic micro pattern decreases with the increase of the direct-writing height and the moving velocity of the flexible substrate, respectively. The fabricated organic microcircuit patterns of the natural drying in air at room temperature were tested by a thin film thermoelectric tester at a detection temperature. The results show that the conductivity of a fabricated organic micro pattern decreases with the increase of the electric field intensity, while the effect of moving velocity and the flow rate on the conductivity is small under the condition where the three other process parameters remained constant.