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The novel aspect of this study was to contextualize the co-localization of biomolecular expression in widened and narrowed periodontal ligament (PDL)-space within a mechanically activated periodontal complex. The PDL is unique as it is the only ligament with both innervation and vascularization. Maxillary molars in 6-week-old male C57BL/6 mice (N = 5) were experimentally translated for 2 weeks using an elastic spacer. Contralateral teeth were used as controls. Mechanical testing of the periodontal complex of a mouse in situ and imaging using X-ray micro-computed tomography (micro-XCT) illustrated deformations within blood vessels (BV) of the PDL. PDL-bone and PDL-cementum entheses at the widened and narrowed PDL-spaces following experimental tooth movement (ETM) illustrated osterix (OSX), bone sialoprotein (BSP), cluster of differentiation 146 (CD146), and protein gene product 9.5 (PGP9.5), indicating active remodeling at these sites. PGP9.5 positive nerve bundles (NBs) were co-localized with multinucleated cells (MCs), Howship's resorption lacunae, and CD146 positive BVs. Association between nerves and MC was complemented by visualizing the proximity of osmium tetroxide stained NBs with the ultrastructure of MCs by performing scanning transmission electron microscopy. Spatial association of NB with BV, and NB with MC, provided insights into the plausible co-activation of NBs to initiate osteoclastic activity. Resorption of mineral occurred as an attempt to restore PDL-space of the load-bearing complex, specifically at the PDL-entheses. Mapping of anatomy-specific structural elements and their association with regenerative molecules by correlating light and electron micrographs provided insights into the use of these extracellular matrix molecules as plausible targets for pharmacological interventions related to tooth movement. Within the realm of tissue regeneration, modulation of load can reverse naturally occurring mineral formation to experimentally induced resorption, and naturally occurring mineral resorption to experimentally induced formation at the enthesial sites to permit tooth translation.

Tomato fruit are especially susceptible to chilling injury (CI) when continuously exposed to temperatures below 12 °C. In this study, integrative comparative analyses of transcriptomics and metabolomics data were performed to uncover the regulatory network in CI tomato fruit. Metabolite profiling analysis found that 7 amino acids, 27 organic acids, 16 of sugars and 22 other compounds had a significantly different content while transcriptomics data showed 1735 differentially expressed genes (DEGs) were down-regulated and 1369 were up-regulated in cold-stored fruit. We found that the contents of citrate, cis-aconitate and succinate were increased, which were consistent with the expression of ATP-citrate synthase (ACS) and isocitrate dehydrogenase (IDH) genes in cold-treated tomato fruit. Cold stress promotes the expression of ACS and IDH which may increase the synthesis of citrate, cis-aconitate and succinate. Alanine and leucine had increased contents, which may result from alanine aminotransferase (ALT) and branched-chain amino acid aminotransferase (BcAT)'s high expression levels, respectively. Overall the transcriptomics and metabolomics data in our study explain the molecular mechanisms of the chilling injury and expands our understanding of the complex regulatory mechanisms of a metabolic network in response to chilling injury in tomato fruit.

Global change factors, such as variation in precipitation regimes and nitrogen (N) deposition, are likely to occur simultaneously and may have profound impacts on the relative abundance of grasses differing in functional traits, such as C3 and C4 species. We conducted an extreme drought and re-watering experiment to understand differences in the resistance and recovery abilities of C3 and C4 grasses under different N deposition scenarios. A C3 perennial grass (Leymus chinensis) and two C4 grasses (annual species Chloris virgata and perennial species Hemarthria altissima) that co-occur in Northeast China were selected as experimental plants. For both C3 and C4 grasses, N addition caused a strong increase in biomass and resulted in more severe drought stress, leading to a change in the dominant photosynthetic limitation during the drought periods. Although N addition increased antioxidant enzyme activities and protective solute concentrations, the carbon fixing capacity did not fully recover to pre-drought levels by the end of the re-watering period. N addition resulted in lower resilience under the drought conditions and lower resistance at the end of the re-watering. However, N addition led to faster recovery of photosynthesis, especially in the C3 grass, which indicate that the effect of N addition on photosynthesis during drought was asymmetric, especially in the plants with different photosynthetic nitrogen use efficiency (PNUE). These findings demonstrated that nitrogen deposition may significant alter the susceptibility of C3 and C4 grass species to drought stress and re-watering, highlighting the asymmetry between resistance and resilience and to improve our understanding about plant responses to climate change.

Understanding groundwater–surface water interaction is essential for water resource management and watershed ecological protection. However, the existing studies often emphasize the tracer role of hydrogeochemical methods (including hydrochemistry and isotopes) while underestimating the importance of analyzing watershed hydraulic characteristics, thus neglecting the indications of the driving mechanisms (hydraulic head difference) for the water exchange. Taking the Songhua River in the Sanjiang Plain as an example, this study combines hydraulic, hydrochemical, and isotopic methods to clarify the groundwater–surface water interactions from both a driving mechanism perspective and a hydrogeochemical characterization perspective within the water cycle. The results indicate that human exploitation has caused river water to infiltrate into groundwater, converting the section into a losing river, where surface water consistently exhibits a hydraulic tendency to recharge the aquifer. The influence zone of the river extends up to 3.5 km from the riverbank, with an average recharge rate from the river reaching 78.04% within this area. This recharge mixes and dilutes the adjacent groundwater, impacting its hydrogeochemical characteristics. This study enhances the understanding of combined methods for groundwater–surface water interaction and provides a scientific basis for water resource management and pollution control strategies in the local agricultural regions. [ABSTRACT FROM AUTHOR]

The hairpin structure is a common and fundamental secondary structure in macromolecules. In this work, the process of the translocation of a model polymer chain with a hairpin structure is studied using Langevin dynamics simulations. The simulation results show that the dynamics of hairpin polymer translocation through a nanopore are influenced by the hairpin structure. Hairpin polymers can be classified into three categories, namely, linear-like, unsteady hairpin, and steady hairpin, according to the interaction with the stem structure. The translocation behavior of linear-like polymers is similar to that of a linear polymer chain. The time taken for the translocation of unsteady hairpin polymers is longer than that for a linear chain because it takes a long time to unfold the hairpin structure, and this time increases with stem interaction and decreases with the driving force. The translocation of steady hairpin polymers is distinct, especially under a weak driving force; the difficulty of unfolding the hairpin structure leads to a low translocation probability and a short translocation time. The translocation behavior of hairpin polymers can be explained by the theory of the free-energy landscape. [ABSTRACT FROM AUTHOR]

This work reported the dark dyeing properties of Dioscorea cirrhosa Lour. tuber extracts with different molecular weights on silk. The study on component analysis indicates that the molecular weight of most condensed tannins and polyphenols in D. cirrhosa L. tuber extracts is higher than 1000. The kinetic study demonstrates that the adsorption processes of D. cirrhosa L. tuber extract components with molecular weights higher than 1000, and components with molecular weights lower than 1000 toward silk fabrics are fitted with the pseudo-second order model, and the survey of adsorption isotherms reveals that multiple interactions occurred between dyes and silk, encompassing hydrogen bonding and van der Waals forces. The dyeing research shows that the dyed silk achieves its darkest color when employing D. cirrhosa L. tuber extract components with molecular weights lower than 1000 with a Fe2+ mordant concentration of 4 g/L and a pH value of 5. The K/S and L* values of dyed silk are 9.05 and 30.77, respectively. Under this dyeing condition, the complex, Fe element content, and Fe2+ ratio on the silk dyed with D. cirrhosa L. tuber extract components with molecular weights lower than 1000 surface are higher than those of D. cirrhosa L. tuber extracts and D. cirrhosa L. tuber extract components with molecular weights higher than 1000. The present study indicates that condensed tannins in D. cirrhosa L. tuber extracts are not the sole active compounds involved in the silk dark dyeing process. Polyphenols with molecular weights below 1000 in D. cirrhosa L. tuber extracts are shown to influence significantly and, in some cases, dominate the silk dark dyeing process. [ABSTRACT FROM AUTHOR]

Economic globalization in the 21st century has been characterized by the rise and spread of global value chains (GVCs). It faces significant challenges due to increasing domestic and international policy uncertainty in the context of emerging mega risks like geopolitical tensions and climate change. This paper begins by constructing a theoretical model for an open economy to study how risk‐averse firms make decisions regarding the sourcing of intermediate inputs in an uncertain environment. Our model solution proposes that firms will source fewer intermediate inputs from countries with more economic uncertainty. An increase in domestic and foreign uncertainty will have opposite impacts on a country's position in GVCs. In this sense, we argue that a country tends to move downstream along GVCs if its own economic policies become more uncertain, and it tends to move upstream with an increase in the uncertainty of its trading partner countries. Our regression analyses, based on data including the World Input–Output Database, World Development Indicators, the UN Comtrade database, and the Economic Policy Uncertainty Index, provide empirical support for this model‐based conclusion. Our findings highlight that a nation must consider foreign economic policy uncertainty and maintain domestic policy stability to participate in GVCs. [ABSTRACT FROM AUTHOR]

Global climate change is intensifying and extreme weather events are occurring frequently, with far-reaching impacts on agricultural production. The Songnen Plain, as an important maize production region in China, faces challenges posed by climate change. This study aims to explore the effects of climate extremes on maize yield and provide a scientific basis for the adaptation of agriculture to climate change in this region. The study focuses on the spatial and temporal evolution characteristics of climate extremes during the maize reproductive period from 1988 to 2020 in the Songnen Plain and their impacts on maize yield. Daily temperature and precipitation data from 11 meteorological stations were selected and combined with maize yield information to assess the spatial and temporal trends of extreme climate indices using statistical methods such as the moving average and Mann–Kendall (M-K) mutation test. Pearson correlation analysis and a random forest algorithm were also used to quantify the degree of influence of extreme climate on maize yield. The results showed that (1) the extreme heat and humidity indices (TN90p, TX90p, CWD, R95p, R10, and SDII) tended to increase, while the cold indices (TN10p, TX10p) and the drought indices (CDD) showed a decreasing trend, suggesting that the climate of the Songnen Plain region tends to be warmer and more humid. (2) The cold indices in the extreme temperature indices showed a spatial pattern of being higher in the north and lower in the south and lower in the west and higher in the east, while the warm indices were the opposite, and the extreme precipitation indices showed a spatial pattern of being higher in the east and lower in the west. (3). Both maize yield and trend yield showed a significant upward trend. Maize meteorological yield showed a fluctuating downward trend within the range of −1.64~0.79 t/hm2. During the 33 years, there were three climatic abundance years, two climatic failure years, and the rest of the years were normal years. (4) The cold index TN10p and warm indices TN90p and CWD were significantly correlated with maize yield, in which TN90p had the highest degree of positive correlation with yield, and in the comprehensive analysis, the importance of extreme climatic events on maize yield was in the order of TN90p, TN10p, and CWD. This study demonstrates the impact of extreme climate indices on maize yield in the Songnen Plain, providing a scientific basis for local agricultural management and decision-making, helping to formulate response strategies to mitigate the negative effects of extreme climate, ensure food security, and promote sustainable agricultural development. [ABSTRACT FROM AUTHOR]