Cellulose nanocrystal thermal smart molecular brushes with upper critical aggregation temperature.

Grafting thermo-responsive polymers onto cellulose nanocrystals (CNCs) and achieving critical temperature regulation has drawn significant research interest. The thermal transition behavior of CNCs can be controlled by adjusting the polymer molecular brushes on the CNCs surface. We synthesized poly((2-dimethylamino) ethyl methacrylate) (PDMAEMA) grafted CNCs via surface-initiated reversible addition-fragmentation chain transfer, followed by modifying PDMAEMA brushes into poly-3-dimethyl(methacryloyloxyethyl) ammonium propane sulfonate (PDMAPS) brushes via quaternization. The critical temperature was regulated by modifying and grafting of poly (ethylene glycol) methacrylate. Found the thermal stimulus-responsive type and transition point of CNCs can be controlled by adjusting the surface molecular brushes. Ultraviolet-visible spectroscopy and dynamic light scattering analyses indicated that CNC-PDMAEMA aggregated above 70 °C, whereas CNC-PDMAPS aggregated below 31 °C. The thermo-responsive materials based on CNCs exhibited a conversion from a lower critical aggregation temperature to an upper critical aggregation temperature (UCAT) type. CNC-PDMAPS-mPEG was obtained by modifying and grafting for UCAT to be regulated to approximately 37 °C, which is close to the human body temperature. CNC-PDMAPS and CNC-PDMAPS-mPEG exhibited only microscopic alterations and could encapsulate and release substances. Therefore, they demonstrate considerable potential for biomedical applications.

Finite Element Analysis of the Effect of Femoral Prosthesis Varus and Valgus Angle Installation on the Lateral Compartment in Unicompartmental Knee Arthroplasty.

BACKGROUND: This study used finite element analysis (FEA) to investigate the effect of varus and valgus angle on the lateral compartment in unicompartmental knee arthroplasty (UKA). METHODS: One patient who underwent UKA was enrolled as the subject. Thirteen working conditions of the femoral prosthesis were simulated at varus and valgus angles of 0°, 2°, 4°, 6°, 8°, 10°, and 12°. A load of 1,000 N was applied downward along the mechanical axis of the femur, and the highest stress values on the surface of the polyethylene liner, cancellous bone under the tibial prosthesis, cartilage of femur lateral condyle, lateral meniscus, and tibial lateral plateau cartilage in each model were recorded. The six highest points were used to calculate the mean value. RESULTS: The highest stress values on the surface of the polyethylene liner, cancellous bone under the tibial prosthesis, cartilage of femur lateral condyle, lateral meniscus, and tibial lateral plateau cartilage increased with an increase in the femoral prosthesis varus/valgus angle. As compared with the standard position of the femoral prosthesis, there was no significant difference in the surface stress values of the polyethylene liner, cancellous bone under the tibial prosthesis, cartilage of femur lateral condyle, lateral meniscus and tibial lateral plateau cartilage when the femoral prosthesis varus/valgus angle was less than 4° (p > 0.05). In addition, the stress magnitude on the polyethylene liner, cancellous bone under the tibial prosthesis, cartilage of femur lateral condyle, lateral meniscus, and tibial lateral plateau cartilage significantly increased when the femoral prosthesis varus/valgus angle was greater than 4° (p < 0.001). CONCLUSIONS: The optimal femoral prosthesis varus/valgus angle in UKA was less than 4°.

In situ growth of Zr-based metal-organic frameworks on cellulose sponges for Hg2+ and methylene blue removal.

Metal-organic frameworks (MOFs) are characterised by high porosity levels and controllable structures, making them ideal adsorbents for wastewater. However, obtaining substrate materials with mechanical stability, excellent pore accessibility, and good processability for compositing MOF crystal powders to adsorb multiple pollutants in complex aqueous environments is challenging. In this study, porous MOFs@ modified cellulose sponge (MCS) composites were fabricated using MCS as a scaffold to provide anchoring sites for the coordination of Zr4+ ions and further in situ synthesis of MOFs, namely UiO-66@MCS and UiO-66-NH2@MCS, which effectively removed heavy metal ions and organic dyes. MOFs@MCS composites exhibit excellent water and dimensional stability, maintaining the pore structure by ambient drying during reuse. Compared with UiO-66@MCS composite, UiO-66-NH2@MCS composite exhibited a higher adsorption capacity of 224.5 mg·g-1 for Hg2+ and 400.9 mg·g-1 for methylene blue (MB). The adsorption of Hg2+ onto the MOFs@MCS composites followed the Langmuir and pseudo-second-order models, whereas the Freundlich and pseudo-second-order models were more suitable for MB adsorption. Moreover, the MOFs@MCS composites exhibited excellent reusability and were selective for the removal of Hg2+. Overall, this approach effectively combines Zr-based MOFs with mechanically and dimensionally stable porous cellulose sponges, rendering the approach suitable for purifying complex wastewater.

Water quality improvement project for initial rainwater pollution and its performance evaluation.

Efficiently addressing initial rainwater pollution is crucial for mitigating urban water pollution. However, the performance evaluation of initial rainwater pollution control project is rarely introduced. In this study, the architecture of effective comprehensive engineering measures for improving the water quality of initial rainwater in Anhui Province, China, was described. Three water quality indicators, ammonia nitrogen (NH3-N), chemical oxygen demand (COD), and total phosphorus (TP), were selected to explore the severity of urban pollution caused by initial rainwater under various rainfall scenarios. A single-factor evaluation method was used to contrast and assess the benefits of the initial rainfall interception project in terms of water quality enhancement. Results showed that initial rainfall pollution was gentler under light rainfall conditions but more prominent under moderate and heavy conditions. The percentages of NH3-N, COD, and TP in Lotus Pond that met the tertiary drinking water standard were 100%, 74.91%, and 100% with great improvement, and the average concentrations of NH3-N, COD, and TP in Fushan Road Drainage have decreased by 91.43%, 10.49%, and 57.33% respectively, after the construction of the interception project. These indicated that the nitrogen and phosphorus pollution were successfully controlled by the control techniques in both locations, but COD concentration has to be addressed with more specialized strategies. Overall, the water quality improvement project for initial rainwater pollution plays a great role in effectively governing initial rainwater pollution and improving river water quality, and provides an effective technical reference for urban water ecological environment management.

Water quality variation and driving factors quantitatively evaluation of urban lakes during quick socioeconomic development.

Rapid urbanisation has caused a significant impact on the ecological environment of urban lakes in the world. To maintain the harmonious development of urban progress and water quality, it is essential to evaluate water quality variation and explore the driving factors quantitatively. A comprehensive evaluation method with cluster analysis and Kriging interpolation was used to explore the spatiotemporal variation in a typical urban lake in China, Chaohu Lake, from 2011 to 2020. The correlation between water quality and socioeconomic factors was evaluated by Pearson correlation analysis. Results indicated that: total phosphorus (TP) and total nitrogen (TN) were the key pollution parameters of Chaohu Lake. The pollution situation was gradually improving, however, and the improvement in chemical oxygen demand (COD) is more evident due to anthropogenic control. The spatial heterogeneity of water quality in Chaohu Lake is remarkable, and the water quality is poor in the west but better in the east. Natural attributes of lakes and external load were the main reasons for the spatial heterogeneity. The western residential areas of Chaohu Lake Basin (CLB) are concentrated, and a large amount of industrial and domestic sewage exacerbates water pollution in the west of tributaries. In contrast, the implementation of water environmental governance policies in recent years has alleviated water pollution. From 2011 to 2020, water quality has improved by 23%-35% in the west and 7%-14% in the east. This study provided a framework for quantitatively assessing water quality variation and its driving forces in urban lakes.

Pollution source identification and abatement for water quality sections in Huangshui River basin, China.

Accurately obtaining the pollution sources and their contribution rates is the basis for refining watershed management. Although many source analysis methods have been proposed, a systematic framework for watershed management is still lacking, including the complete process of pollution source identification to control. We proposed a framework for identification and abatement of pollutants and applied in the Huangshui River Basin. A newer contaminant flux variation method based on a one-dimensional river water quality model was used to calculate the contribution of pollutants. The contributions of various factors to the over-standard parameters of water quality sections at different spatial and temporal scales were calculated. Based on the calculation results, corresponding pollution abatement projects were developed, and the effectiveness of the projects was evaluated through scenario simulation. Our results showed that the large scale livestock and poultry farms and sewage treatment plants were the largest sources of total nitrogen (TP) in Xiaoxia bridge section, with contribution rates of 46.02% and 36.74%, respectively. Additionally, the largest contribution sources of ammonia nitrogen (NH3-N) were sewage treatment plants (36.17%) and industrial sewage (26.33%). Three towns that contributed the most to TP were Lejiawan Town (14.4%), Ganhetan Town (7.3%) and Handong Hui Nationality town (6.6%), while NH3-N mainly from the Lejiawan Town (15.9%), Xinghai Road Sub-district (12.4%) and Mafang Sub-district (9.5%). Further analysis found that point sources in these towns were the main contributor to TP and NH3-N. Accordingly, we developed abatement projects for point sources. Scenario simulation indicated that the TP and NH3-N could be significantly improved by closing down and upgrading relevant sewage treatment plants and building facilities for large scale livestock and poultry farms. The framework adopted in this study can accurately identify pollution sources and evaluate the effectiveness of pollution abatement projects, which is conducive to the refined water environment management.

Co-assembly of stearoylated cellulose nanocrystals and GO (or CNTs) for the construction of superhydrophobic hierarchical structure with enhanced photothermal conversion.

The development of photothermal materials with high photothermal-conversion efficiencies is important in a range of applications, such as power generation, sterilization, desalination, and energy-production. To date, a few reports have been published related to improving the photothermal conversion performances of photothermal materials based on self-assembled nanolamellae. Herein, hybrid films of co-assembled stearoylated cellulose nanocrystals (SCNCs) and polymer-grafted graphene oxide (pGO)/polymer-grafted carbon nanotubes (pCNTs) were prepared. The chemical compositions, microstructures, and morphologies of these products were characterized, and it was found that the self-assembled SCNC structures exhibited numerous surface nanolamellae due to crystallization of the long alkyl chains. The hybrid films (i.e., SCNC/pGO and SCNC/pCNTs films) consisted of ordered nanoflake structures, confirming the co-assembly behavior of the SCNCs with pGO or pCNTs. The melting temperature (~65 °C) and latent heat of melting (87.87 J/g) of SCNC1.07 indicate its potential to induce the formation of nanolamellar pGO or pCNTs. Under light irradiation (50-200 mW/cm2), the pCNTs exhibited a higher light absorption capacity than pGO, and as a result, the SCNC/pCNTs film exhibited the best photothermal performance and electrical conversion, ultimately demonstrating its potential for use as a solar thermal device in practical applications.

Decoupling in international business: The 'new' vulnerability of globalization and MNEs' response strategies.

What can MNEs learn from the COVID-19 pandemic? IB scholars have provided ample insights into this question with many focusing on risk management. Complementing these insights, we argue that MNEs should also consider the long-lasting effect that COVID-19, inter alia, had on the institutional logic underlying globalization. The U.S. and its allies have redefined their logic from pursuing cost-reduction to building partnerships based on shared value, aiming to substitute China's role in the world economy. The geopolitical pressure for decoupling from China is the source of 'new' vulnerability of globalization. Such pressure is counteracted by economic rationality, creating unsettled priority between the globalization and deglobalization logics at the macro-level institutional space. Combining both risk-management and institutional logic perspectives, we develop a more comprehensive framework on how MNEs should respond to these challenges. This paper contributes to the debate regarding the impact of COVID-19 on globalization, suggesting that neither globalization nor deglobalization logics will prevail in the short run, and IB will likely be more fractured in the long run, based on not only geographic but also ideological and value propinquity. In strategic sectors, the balance will shift toward bifurcation while in others the balance will shift toward the globalization logic.

Que peuvent apprendre les entreprises multinationales (Multinational Enterprises ­ MNEs) de la pandémie de COVID-19 ? A cette question, les chercheurs en affaires internationales (International Business ­ IB) ont fourni de nombreux renseignements dont beaucoup se concentrent sur la gestion des risques. En complément de ces renseignements, nous argumentons que les MNEs devraient également tenir compte de l'effet durable que la COVID-19 a eu, entre autres, sur les logiques institutionnelles sous-tendant la globalisation. Les États-Unis et leurs alliés ont redéfini leur logique, passant de la recherche de la réduction des coûts à la construction de partenariats fondés sur la valeur partagée, et ce dans le but de substituer le rôle de la Chine dans l'économie mondiale. La pression géopolitique en faveur de la dissociation de la Chine constitue la source de la "nouvelle" vulnérabilité de la globalisation. Une telle pression est contrecarrée par la rationalité économique, impliquant une priorité instable entre les logiques de globalisation et de dé-globalisation dans l'espace institutionnel au niveau macro. En combinant les perspectives de la gestion des risques et de la logique institutionnelle, nous développons un cadre théorique plus complet sur la façon dont les MNEs devraient répondre à ces défis. Cet article contribue au débat sur l'impact de la COVID-19 sur la globalisation en suggérant que ni la logique de globalisation ni celle de dé-globalisation ne prévaudront à court terme, et que l'IB sera probablement plus fracturé à long terme en fonction de la proximité géographique, idéologique et de valeurs. Dans les secteurs stratégiques, l'équilibre penchera vers la bifurcation tandis que dans d'autres, il penchera vers la logique de globalisation.

¿Qué pueden aprender las empresas multinacionales de la pandemia? Los académicos de negocios internacionales han dado numerosos aportes sobre esta pregunta, muchas de ellas enfocadas en la gestión de riesgos. Complementando estos aportes, sostenemos que las empresas multinacionales deben también considerar el efecto duradero que COVID, entre otras cosas, tuvo en las lógicas institucionales que subyacen la globalización. Los Estados Unidos y sus aliados han redefinido su lógica de perseguir reducción de costos a la construcción de valor basado en valor compartido, con el objetivo de substituir el papel de China en la economía mundial. La presión geopolítica para desacoplarse de China es la fuente de la "nueva" vulnerabilidad de la globalización. Esta presión es contrarrestada con la racionalidad económica, creando prioridades inestables entre las lógicas de globalización y desglobalización a nivel macro del espacio institucional. Combinando las perspectivas tanto gestión de riesgos como la lógica institucional, desarrollamos un marco más completo sobre las multinacionales deben responder a estos retos. Este manuscrito contribuye al debate sobre el impacto del COVID-19 en la globalización, indicando que ni la lógica de globalización o de desglobalización van a prevalecer en el corto plazo, y los negocios internacionales estén más fracturados en el largo plazo, en función no solo en la proximidad geográfica, sino también ideológica y de valores. En sectores estratégicos la balanza se inclinará hacia la bifurcación mientras que en los otros la balanza se inclinará a la lógica de globalización.

O que MNEs podem aprender com a pandemia do COVID-19? Acadêmicos de IB forneceram amplos insights sobre essa questão, muitos deles focados no gerenciamento de riscos. Complementando esses insights, argumentamos que MNEs também devem considerar o efeito duradouro que o COVID-19 teve, entre outros, nas lógicas institucionais subjacentes à globalização. Os EUA e seus aliados redefiniram sua lógica de buscar a redução de custos para construir parcerias baseadas no valor compartilhado, visando substituir o papel da China na economia mundial. A pressão geopolítica para a separação da China é a fonte da "nova" vulnerabilidade da globalização. Tal pressão é contrabalançada pela racionalidade econômica, criando uma prioridade instável entre as lógicas da globalização e da desglobalização no espaço institucional de nível macro. Combinando as perspectivas de gerenciamento de risco e lógica institucional, desenvolvemos um modelo mais abrangente sobre como MNEs devem responder a esses desafios. Este artigo contribui para o debate sobre o impacto do COVID-19 na globalização, sugerindo que nem a lógica da globalização nem a da desglobalização prevalecerão no curto prazo, e IB provavelmente será mais fendido no longo prazo, com base não apenas na proximidade geográfica, mas também na ideológica e de valor. Em setores estratégicos o equilíbrio se deslocará para a bifurcação enquanto em outros o equilíbrio se deslocará para a lógica da globalização..

Scale effects of land use on river water quality: a case study of the Tuojiang River Basin, China.

Assessing the scale effects of land use on water quality is of great significance for effectively controlling nonpoint source (NPS) pollution in river basins. In this study, redundancy analysis (RDA) and stepwise multiple linear regression (SMLR) analysis were applied to assess the effects of land use on water quality across multiscales in the Tuojiang River Basin. All monitoring sections were classified into three groups according to the characteristics of land use and cluster analysis of water quality. Results showed that the improvement in water quality of rivers in the Tuojiang River Basin lies in the emphasis and protection of the small-scale scope. Concomitantly, the linkages between individual water quality parameter and land use were highly dependent on spatial scales and regional basis. For the upstream group A, urban land is the main source of COD and TN pollution, while industrial and rural residential land contributed the most to TP pollution. Water body exhibits favorable effects on ammonia nitrogen due to its absorption and degradation, together with the growth of phytoplankton within it. For group B in the middle-lower reaches, controlling the input of organic fertilizers in paddy field will effectively alleviate COD pollution. Increasing the proportion of grassland near the riparian zone can have a positive effect on TN and TP pollution. It should continue to strengthen the strict supervision of NH3-N concentration in wastewater discharge from industrial enterprises. Our results can provide important information for land use planning and making multiple scale measures for water quality conservation.

Comparative analysis of water quality prediction performance based on LSTM in the Haihe River Basin, China.

As the most water shortage and water polluted area in China, the water quality prediction is of utmost needed and important in Haihe River Basin for its water resource management. The long short-term memory (LSTM) has been a widely used tool for water quality forecast in recent years. The performance and adaptability of LSTM for water quality prediction of different indicators needs to be discussed before it adopted in a specific basin. However, literature contains very few studies on the comparative analysis of the various prediction accuracy of different water quality indicators and the causes, especially in Haihe River Basin. In this study, LSTM was employed to predict biochemical oxygen demand (BOD), permanganate index (CODMn), dissolved oxygen (DO), ammonia nitrogen (NH3-N), total phosphorus (TP), hydrogen ion concentration (pH), and chemical oxygen demand digested by potassium dichromate (CODCr). According to results under 24 different input conditions, it is demonstrated that LSTMs present better predicting on BOD, CODMn, CODCr, and TP (median Nash-Sutcliffe efficiency reaching 0.766, 0.835, 0.837, and 0.711, respectively) than NH3-N, DO, and pH (median Nash-Sutcliffe efficiency of 0.638, 0.625, and 0.229, respectively). Besides, the performance of LSTM to predict water quality is linearly related to the maximum value of temporal autocorrelation and cross-correlation coefficients of water quality indicators calculated by maximal information coefficient with the coefficients of determination of 0.79 to approximately 0.80. This study would provide new knowledge and support for the practical application and improvement of the LSTM in water quality prediction.

Flexible Janus wood membrane with asymmetric wettability for high-efficient switchable oil/water emulsion separation.

Janus membranes have attracted much attention for switchable oil/water separation because they have opposite wetting behavior on each side. However, it remains a challenge to fabricate Janus membranes with asymmetric wettability from biomass by simple methods. Herein, we prepared a flexible Janus wood (JW) membrane by cutting the natural wood along the longitudinal direction, followed by a facile top-down approach. The hydrophobic lignin was removed from the wood to prepare a highly porous and superhydrophilic wood (SW) with underwater superoleophobicity. Then, one side of the SW was sprayed with a mixture of 1H,1H,2H,2H-perfluorooctyltrichlorosilane/SiO2 nanoparticles to form a superhydrophobic surface that hardly affected the wettability of the other side. The obtained JW membrane maintains its selective wettability in harsh environments owing to its durability and stability. Furthermore, it has a switchable, high separation efficiency of >99% for both oil-in-water and water-in-oil emulsions, which can be attributed to the unique wettability and hierarchical micro/nano structure of the JW membrane. Notably, the three-dimensional interconnected micro/nanochannels (pits and nanopores) of the JW membrane are beneficial to the size-sieving effect during emulsion separation. At the same time, the layered channels (tracheids and vessels) enable multiple separations. JW membrane is sustainable, inexpensive, stable, and easy to manufacture, providing more implications for the innovation of biomass-based Janus separation materials in industrial wastewater treatment.

Click chemistry-induced modification of acrylated cellulose nanocrystals for application in PVA-based nanocomposites.

The surface functionalization of cellulose nanocrystals (CNC) is crucial for promoting their diverse applications, especially regarding their use as sustainable biobased polymer reinforcements. In this study, we develop poly (vinyl alcohol) (PVA)-CNC composites with improved tensile strength and gas-barrier performance using CNC-based nanofillers. Acrylated CNCs (ACNCs) were prepared from cellulose via one-pot acid hydrolysis/Fischer esterification; subsequently, surface modification was performed through a thiol-ene reaction to obtain surface-thiolated ACNCs, namely, DACNC, MACNC, and PACNC. The various functional groups on the surface-thiolated ACNCs not only affect the dispersion stability but also alter their interfacial interactions with the PVA matrix, thus realizing the PVA nanocomposites with tailored properties, including the thermal properties, mechanical properties, and gas barrier performance. This study demonstrates that surface-thiolated ACNCs with appropriate surface chemistry and loading levels can serve as excellent nanofillers for PVA, forming biobased composites with desired properties.

Water-Quality Assessment and Pollution-Risk Early-Warning System Based on Web Crawler Technology and LSTM.

The openly released and measured data from automatic hydrological and water quality stations in China provide strong data support for water environmental protection management and scientific research. However, current public data on hydrology and water quality only provide real-time data through data tables in a shared page. To excavate the supporting effect of these data on water environmental protection, this paper designs a water-quality-prediction and pollution-risk early-warning system. In this system, crawler technology was used for data collection from public real-time data. Additionally, a modified long short-term memory (LSTM) was adopted to predict the water quality and provide an early warning for pollution risks. According to geographic information technology, this system can show the process of spatial and temporal variations of hydrology and water quality in China. At the same time, the current and future water quality of important monitoring sites can be quickly evaluated and predicted, together with the pollution-risk early warning. The data collected and the water-quality-prediction technique in the system can be shared and used for supporting hydrology and in water quality research and management.

Flexoelectricity-Enhanced Photovoltaic Effect in Self-Polarized Flexible PZT Nanowire Array Devices.

In this investigation, we report the flexoelectricity-enhanced photovoltaic (FPV) effect in a flexible Pb(Zr0.52Ti0.48)O3 nanowire (PZT NW) array/PDMS (polydimethylsiloxane) nanocomposite. The simulation result of density functional theory (DFT) indicated that the FPV effect in PZT NWs can be greatly affected by the interactions of the strain gradients with the internal field generated by self-polarization. We found that when the nanocomposite film was curved down, the photovoltaic current of the aligned PZT-NW/PDMS composite increased by 84.6-fold and 27.6-fold compared with the PZT-nanoparticles/PDMS and randomly aligned PZT-NW/PDMS nanocomposites at the same curvature, respectively. This is mainly ascribed to the increased flexoelectricity in the aligned PZT-NW/PDMS nanocomposite. This study will contribute to a full understanding of the influence of nanoparticle shape on the flexophotovoltaic effect of nanocomposites. It will have potential use in nanocomposites for the study of the FPV effect and associated applications.

Aliphatic chains grafted cellulose nanocrystals with core-corona structures for efficient toughening of PLA composites.

To promote the replacement of nondegradable petrochemical-based polymers with green polylactic acid (PLA) materials, aliphatic chains-grafted cellulose nanocrystals (ECNCs) were prepared and used as nanofillers to overcome the disadvantage of poor toughness of PLA. ECNCs with core-corona structures were obtained by modifying cellulose nanocrystals (CNC) with valeryl chloride, octanoyl chloride, dodecanoyl chloride, and stearoyl chloride. ECNCs consists of a cellulose crystalline core and a soft esterified corona layer with aliphatic chains. Among the diverse ECNCs, the obtained EOCNC by esterification of octanoyl chloride exhibited most efficient enhancement of the toughness of PLA. Specifically, PLA/EOCNC-1% film displayed the best elongation at breakage of 108%, which was 6.4 times that of pure PLA. The esterified outer layer of ECNCs, which improves the interfacial compatibility, is one of the key factors contributing to toughening of PLA. These ECNCs with core-corona structure open up new directions for the application of PLA advanced composites.

Spatiotemporal heterogeneities and driving factors of water quality and trophic state of a typical urban shallow lake (Taihu, China).

Water quality deterioration and eutrophication of urban shallow lakes are global ecological problems with increasing concern and greater environmental efforts. In this study, spatiotemporal changes of water quality and eutrophication were assessed by trophic level index (TLI), cluster analysis, and spatial interpolation methods in Lake Taihu and its sub-lakes from 2015 to 2019. Results showed that the Taihu had poor water quality and maintained a light-eutropher state overall, mainly astricted by the total nitrogen (TN) and the total phosphorus (TP). All nutrient parameters reached relatively higher concentrations in the northwestern and northern areas. Meiliang Bay was the most polluted and nutrient-rich area. In terms of trend, the Mann-Kendall test highlighted that the TP and chlorophyll-a (Chl-a) concentrations increased significantly while the TN and five-day biochemical oxygen demand (BOD5) decreased. The massive nutrient loads caused by human activity from the northwestern Taihu and the geomorphological characteristic of the north closed bays were the main contributors to the spatial heterogeneity in water quality. The main driving force of the alleviative nitrogen pollution was the declining river inflow nitrogen loading, and phosphorus pollution was affected more by accumulated endogenous pollution and decline in aquatic plants area, as well as closely linked with algae biomass. Further water pollution and eutrophication restoration of Taihu should focus on the nutrient reductions and those heavily polluted closed bays.

Combined analysis of multi-omics reveals the potential mechanism of flower color and aroma formation in Macadamia integrifolia.

Introduction: Macadamia integrifolia Maiden & Betche is a domesticated high-value nut crop. The development of nut flower affects the fruit setting rate, yield and quality of nuts. Therefore, in this experiment, two varieties with different flower color, flowering time, flowering quantity and nut yield (single fruit weight) were selected as the research objects. Methods: Transcriptome (RNA-Seq) and metabolome (LC-MS/MS, GC-MS) analyses were performed to study the regulatory mechanisms of nut flower development, color and aroma. Results: The results indicated that plant hormone signal transduction, starch sucrose metabolism, phenylpropanoid metabolism, flavonoid biosynthesis, and anthocyanin biosynthesis pathways were related to nut flower development and flower color formation. In the early stage of flowering, most of the differentially expressed genes (DEGs) are involved in the IAA signal transduction pathway, while in the later stage, the brassinolide signal pathway is mainly involved. In starch and sugar metabolism, DEGs are mainly involved in regulating and hydrolyzing stored starch into small molecular sugars in flower tissues. In the phenylpropanoid biosynthesis pathway, DEGs are mainly related to the color and aroma (volatile organic compounds, VOCs) formation of nut flowers. Four color formation metabolites (anthocyanins) in nut flowers were found by LC-MS/MS detection. In addition, the VOCs showed no significant difference between red nut flowers (R) and white nut flowers (W), which was mainly reflected in the aroma formation stage (flowering time). And 12 common differentially accumulation metabolites (DAMs) were detected by GC-MS and LC-MS/MS. At the same time, the DEGs, AAT, LOX and PAL genes, were also identified to regulate key metabolite synthesis during nut flower development. These genes were further verified by qRT-PCR. Conclusion: Our results provide insights to clarify the molecular mechanism of color and aroma formation during M. integrifolia flower development that pave the way for nut quality and yield breeding.

Deep learning system compared with expert endoscopists in predicting early gastric cancer and its invasion depth and differentiation status (with videos).

BACKGROUND AND AIMS: We aimed to develop and validate a deep learning-based system that covers various aspects of early gastric cancer (EGC) diagnosis, including detecting gastric neoplasm, identifying EGC, and predicting EGC invasion depth and differentiation status. Herein, we provide a state-of-the-art comparison of the system with endoscopists using real-time videos in a nationwide human-machine competition. METHODS: This multicenter, prospective, real-time, competitive comparative, diagnostic study enrolled consecutive patients who received magnifying narrow-band imaging endoscopy at the Peking University Cancer Hospital from June 9, 2020 to November 17, 2020. The offline competition was conducted in Wuhan, China, and the endoscopists and the system simultaneously read patients' videos and made diagnoses. The primary outcomes were sensitivity in detecting neoplasms and diagnosing EGCs. RESULTS: One hundred videos, including 37 EGCs and 63 noncancerous lesions, were enrolled; 46 endoscopists from 44 hospitals in 19 provinces in China participated in the competition. The sensitivity rates of the system for detecting neoplasms and diagnosing EGCs were 87.81% and 100%, respectively, significantly higher than those of endoscopists (83.51% [95% confidence interval [CI], 81.23-85.79] and 87.13% [95% CI, 83.75-90.51], respectively). Accuracy rates of the system for predicting EGC invasion depth and differentiation status were 78.57% and 71.43%, respectively, slightly higher than those of endoscopists (63.75% [95% CI, 61.12-66.39] and 64.41% [95% CI, 60.65-68.16], respectively). CONCLUSIONS: The system outperformed endoscopists in identifying EGCs and was comparable with endoscopists in predicting EGC invasion depth and differentiation status in videos. This deep learning-based system could be a powerful tool to assist endoscopists in EGC diagnosis in clinical practice.

Basin-Scale Pollution Loads Analyzed Based on Coupled Empirical Models and Numerical Models.

Pollutant source apportionment is of great significance for water environmental protection. However, it is still challenging to accurately quantify pollutant loads at basin-scale. Refined analytical methods combined the pollution discharge coefficient method (PDCM), field observation, and numerical model (Soil & Water Assessment Tool, SWAT) to make quantitative source appointment in the Tuojiang River, a key tributary of the upper Yangtze River. The chemical oxygen demand (COD), total nitrogen (TN), total phosphorus (TP), and ammonia nitrogen (N-NH4+) were analyzed. Results showed that the urban sewage treatment plant point source has the largest contribution to COD, TN, and N-NH4+, while TP is mostly from the agricultural sources throughout the year. The total inflowing loads of pollution sources are significantly affected by rainfall. The overall pollution characteristics showed that pollutant loads present in different seasons are as follows: wet season > normal season > dry season. The month with the highest levels of pollutants is July in the wet season. Among the nine cities, the city that contributes the most COD, TN and N-NH4+, is Neijiang, accounting for about 25%, and the city that contributes the most TP is Deyang, accounting for 23%. Among the sub-basins, the Fuxi River subbasin and Qiuxihe River subbasin contribute the most pollutant loads. The technical framework adopted in this paper can be used to accurately identify the types, administrative regions and sub-basins of the main pollution sources in the watershed, which is conducive to management and governance of the environment.

Spatial-temporal distribution and evolutionary characteristics of water environment sudden pollution incidents in China from 2006 to 2018.

Sudden water pollution incidents (SWPI) are random and harmful, which is a problem that cannot be ignored in ecological environment governance and economic development. Identifying spatial-temporal distribution characteristics of SWPI is essential for the disaster prevention and the early warning of water environment. The Kernel Density (DE) and spatial mean center of SWPI transfer curve were used to explore the characteristics with the dataset of 1174 cases from 2006 to 2018 in China. Results showed that: (1) From the time point of view, there was an overall upward trend in the overall number of SWPI. (2) At a regional scale, Eastern China, Southwest China, and Southern China underwent a high frequency with 69.93% of SWPI. The Fujian, Guangdong and Chongqing provinces were specified as the top 3 provinces with incident frequencies. The Yangtze River Basin and the Pearl River Basin were two regions where water pollution incidents occur more often, more than 50% of incidents among basins in China every year. (3) In general, SWPI presents a northeast-southwest distribution pattern and center of SWPI moves in the direction of west by south. (4) More than half of the incidents (57.24% of the total) were induced by illegal pollutant discharge and production safety accidents.