The optical purity of cannabichromene (CBC, ) is affected by the matrix in which it is generated by thermolysis from its native carboxylated form (cannabichromenic acid, CBCA, ). Thus, thermolysis at 130 °C caused a marked decrease of the enantiomeric excess (ee), while, under the same conditions, only a modest decrease of optical purity was observed when thermolysis was carried out . To rationalize these puzzling observations, the kinetics of thermal (100 °C) racemization of enantiopure cannabichromene () was evaluated by enantioselective ultrahigh performance liquid chromatography in solvents (decalin and isopropyl alcohol, neat and acidified with TFA) and surfaces (native and silanized borosilicate glass) of complementary polarity. Optical stability was more than halved in isopropanol compared to decalin ( 50 h vs 135 h), but acidification had no effect on racemization. However, contact with a solid surface dramatically accelerated the process, with a of only 6 h on both glass surfaces. The overall extent of racemization of enantiopure CBC () was compared under conditions commonly used for decarboxylation (heating at 130 °C) between a decalin solution and a thin film on three different surfaces (native and silanized borosilicate glass and powdered blank cannabis biomass). In line with the kinetic data, a significant erosion of enantiopurity was observed on all solid surfaces compared to the solution. These observations suggest that discrepancies in the reported enantiomeric purity of natural CBC could be not only of biogenetic derivation but also be associated with the decarboxylation protocol of cannabichromenic acid (). These findings, while relevant for the exploitation of the bioactivity of natural CBC for human health, should also prompt the adoption of a standardized decarboxylation protocol for the studies on the configurational status of CBC () in cannabis and, in general, of cannabinochromanoids in nature.

The impact of pyrite mining on water quality is a global concern. This study investigates the impact of acid mine drainage (AMD) from an abandoned pyrite mine in the Qinling Mountains on surface and groundwater hydrochemistry and rare earth elements (REEs) evolution. A total of 54 water samples were collected in 2021, of which the Muzi River downstream of the mining area was repeated three times in three sampling periods. Hydrogeochemical methods and stable isotope techniques were used to analyze the impacts of AMD. Results showed that tailing water in comparison to groundwater and surface waters exhibits low pH with high concentrations of SO, potentially toxic elements (PTEs), and REEs, and is characterized by normalized middle REE (MREE) enrichment. Groundwater is less influenced by AMD and shows HCO-Ca and HCO-Ca·Na types. AMD contaminates surface water to different degrees. Surface water received SO input from AMD, exhibited SO-Ca, SO·HCO-Ca, and HCO·SO-Ca types within the mining area, and evolved from HCO·SO-Ca to HCO-Ca downstream as AMD influence diminishes. High concentrations of PTEs and REEs are presented in AMD and seepage near the slag heap, and decreased rapidly along the flow path, while SO migrated over longer distances. The water in the study area primarily originates from atmospheric precipitation, with close relation among surface water, groundwater, and tailing water. Water-rock interactions and pyrite oxidation governed the hydrochemical composition, with sulfide oxidation facilitated the carbonatite-water reaction, which alleviated sulfide oxidation-induced acidification. The concentrations of PTEs are regulated by adsorption and precipitation, carbonate buffering, and dilution along the flow path. REEs are mainly controlled by pH, inorganic complexation, and secondary mineral adsorption. As the pH changes from acidic to neutral or weakly alkaline, REEs shift from sulfate-complex dominated to carbonate-complex dominated. These insights contribute to a better understanding of AMD impacts on surface and groundwater, providing a basis for the rational management of AMD.

In response to the safety risks posed by cadmium (Cd)-contaminated rice fields worldwide, a suitable production-and-restoration strategy is required for actual agricultural practices. To investigate the remediation effects of different accumulation varieties in rapeseed-rice cropping systems and their influence on Cd migration and transportation, field experiments were conducted based on different planting combinations (FWHR, conventional rice variety (HR) monoculture under fallow; FWLR, low Cd-accumulating rice variety (LR) monoculture under fallow; LOLR, LO (low Cd-accumulating rapeseed variety)-LR rotation; LOHR, LO-HR rotation; HOLR, HO (high Cd-accumulating rapeseed variety)-LR rotation; HOHR, HO-HR rotation). The study found that a rapeseed and rice rotation with appropriate varieties could reduce the rice grain Cd content, increase rice yield, and remove soil Cd without affecting agricultural production efficiency. Compared to the fallow-conventional rice pattern, various rapeseed-rice rotations reduced the Cd content of rice grains by 15 %-38 %, and significantly increased the available potassium (Ava-K) in the subsequent rice soil by 29.6-56.4 mg/kg. The total economic benefits increased by $500-$1800 per hectare. A high accumulation variety of rapeseed and low accumulation variety of rice produced the most effective reduction in Cd levels, with a reduction rate of 38 % in brown rice and an annual removal rate of 24.42 g/hm. This combination also resulted in a 29 % increase in rice yield compared to the fallow-low accumulation variety rice pattern. Structural equation modeling revealed that with the combined action of crop rotation and variety selection the crop rotation directly reduced the soil available Cd or had an indirect effect by weakening the root-zone acidification effect and increasing soil Ava-P. The rotation of rapeseed and rice with carefully selected matching varieties is a feasible solution for the safe production and pollution remediation of Cd-contaminated paddy fields.

Disturbed flow (DF) plays a critical role in the development and progression of cardiovascular disease (CVD). Hydrogen sulfide (HS) is involved in physiological processes within the cardiovascular system. However, its specific contribution to DF-induced vascular remodeling remains unclear. Here, we showed that the HS donor, NaHS suppressed DF-induced vascular remodeling in mice. Further experiments demonstrated that NaHS inhibited the proliferation and migration of vascular smooth muscle cells (VSMCs) induced by platelet-derived growth factor-BB (PDGF), as well as the autophagy triggered by DF and PDGF. Mechanistically, RNA-Seq results revealed that NaHS counteracted the PDGF-induced upregulation of lactate dehydrogenase B (LDHB). Overexpression of LDHB abolished the protective effect of NaHS on DF-induced vascular remodeling. Furthermore, LDHB interacted with vacuolar-type proton ATPase catalytic subunit A (ATP6V1A), leading to lysosomal acidification, a process that was attenuated by NaHS treatment. The residues of leucine (Leu) 57 in ATP6V1A and serine (Ser) 269 in LDHB are critical for their interaction. Notably, the expression of LDHB was found to be elevated in vascular tissues from patients with abdominal aortic aneurysms (AAA) and thoracic aortic aneurysms (TAA). These data identify a molecular mechanism by which HS attenuates DF-induced vascular remodeling by inhibiting LDHB and disrupting the interaction between LDHB and ATP6V1A, thereby impeding the autophagy process. Our findings provide insight that HS or targeting LDHB has therapeutic potential for preventing and treating vascular remodeling.

When humans drive rapid environmental change, is it favourable to be a generalist or specialist? To address this question, we compare how specialist and generalist marine herbivores adjust their isotopic niches (used as proxy for trophic niche) in response to predicted resource alterations under the simulated effects of ocean warming and acidification (based on a 6-month mesocosm experiment). Here, we show that when exposed to multiple climate stressors, food resources homogenized towards dominance of turf algae and suspended organic matter, with generalists and specialists adjusting their trophic niches in opposing ways. Whilst the niche breath of most generalists narrowed under climate stressors, those of specialists generally broadened, causing increasing overlap between their niches. The magnitude of this change was such that some generalists turned into specialists, and vice versa. Under ocean acidification, there was a greater probability of generalists increasing and specialists maintaining their biomass, respectively, but under warming the biomass of both specialists and generalists had a greater probability of collapse. For specialists, this collapse occurred even though they had adequate thermal tolerance and the capacity to expand their trophic niche. Climate change constrains or liberates resources, but where they are homogenized, generalists and specialists are likely to converge their trophic niches so they can exploit transforming environments for their survival or adaptive advantage.

Plant photosynthesis significantly regulates atmospheric CO₂ but is often limited by nitrogen (N) availability. While N deposition could alleviate this limitation and enhance gross ecosystem productivity (GEP), its long-term effects are uncertain due to potential negative impacts like biodiversity loss and soil acidification. Yet, many long-term N addition experiments emphasize community biomass over gross GEP. Here, we conducted a six-year N addition experiment in an alpine meadow, frequently monitoring GEP, community structure, aboveground net primary productivity (ANPP)and plant traits. We found that N addition significantly enhanced GEP in the first three years, but during 4-6 years this effect disappeared. We further disentangled the mechanisms affecting GEP into biomass-based and non-biomass-based processes. The latter is expressed as biomass-specific GEP, defined as GEP per unit biomass. Differing with GEP, biomass-specific GEP provides a metric of carbon assimilation efficiency normalized to biomass. Unlike previous studies, we found that it was not ANPP, but specific GEP that determined the loss of the short-term N effect. ANPP showed a consistent increase under N addition, whereas specific GEP decreased in the last three years. This specific GEP reduction was primarily regulated by biodiversity loss and increased light limitation under N addition. Overall, our findings suggest that short-term benefits of N deposition on GEP are not sustained in long term, highlighting the need to explore the non-biomass-based mechanisms to better predict ecosystem responses to prolonged N enrichment.

Dinoflagellates, both armored and unarmored, with distinct cell wall difference, are being affected by elevated CO-induced ocean acidification (OA). However, their specific responses to OA are not well understood. In this study, we investigated the physiological and molecular response of the armored species Prorocentrum obtusidens and the unarmored species Karenia mikimotoi to OA over a 28-day period. The results show that the two species responded differently to OA. Cell growth rate, particulate organic carbon (POC) content, and the activities of C pathway enzymes decreased in P. obtusidens under future acidified ocean condition (pH 7.8, 1000 μatm pCO), but the activities of carbonic anhydrase (CA), ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO), and superoxide dismutase (SOD) increased. Whereas cell growth rate, contents of Chl a and PON, and SOD activity altered insignificantly in K. mikimotoi, but contents of POC and total carbohydrate, and the activity of RubisCO increased while the activities of CA and C pathway enzymes decreased. Transcriptomic analysis indicates that genes associated with antioxidative response, heat shock protein, proteasome, signal transduction, ribosome, and pH regulation were up-regulated in P. obtusidens but down-regulated in K. mikimotoi. Notably, the synthesis of soluble organic matter (i.e., spermidine and trehalose) was enhanced in K. mikimotoi, thereby regulating intracellular pH and improving stress resistance. This study highlights the divergent response of the armored and unarmored dinoflagellates to OA, with the unarmored dinoflagellate exhibiting a higher ability to withstand this stressor. Therefore, caution should be exercised when predicting the behavior and the eventual fate of dinoflagellates in the future acidified ocean.

As the most significant carbon sink on Earth, the ocean has been inevitably absorbing excess atmospheric CO, leading to high concentration of CO that threatens marine life. Like emissions of greenhouse gases, this issue demands urgent attention. Hence, comprehensive investigation and comparison, including both non-electrochemical and electrochemical direct ocean capture (DOC) methods, are revealed in this review. The non-electrochemical approach utilizes specialized materials such as gas-permeable membranes (GPM), hollow fiber membrane contactors (HFMC), and ion exchange resins to extract CO from seawater. In contrast, the electrochemical method employs chemical reactions to generate H or OH ions, which adjust the pH value of seawater to either release CO gas or precipitate carbonate, thereby removing dissolved carbon. This article comprehensively overviews each method, including the latest research findings, underlying principles, employed equipment, and performance metrics. Finally, the achievements, current gaps, corresponding perspectives, and potential solutions in CO capture from seawater are also proposed.

This study investigated the effects of pineapple peel powder with varied chemical profiles and sonication-assisted polyphenol biotransformation during fermentation on the quality characteristics of yogurt products. It aimed at exploring the feasibility of sonication-assisted fermentation to enhance the physicochemical properties, control post-acidification, and improve antioxidant activities in yogurts fortified with polyphenol-rich pineapple peel powder. Targeted analysis showed that polyphenol-rich pineapple dietary fiber obtained by ultrasonication-assisted extraction (NPFU) exhibited the slowest rates of acidification, highest antioxidant capacity, and lowest degree of whey separation at 21.67 %. Sonication pretreatments significantly increased transformation of free phenolic acids derived from pineapple peel fiber during fermentation, particularly increasing the accumulation of ferulic acid, caffeic acid and 5-hydroxyflavone, revealing the positive effects of sonication-mediated fermentation in promoting the hydrolysis of conjugated phenolics into free fractions. Yogurts fortified with pineapple peel fiber displayed significantly higher antioxidant activities (p < 0.05) compared to those with pineapple peel whole powder, corresponding with the increased free phenolics. Non-targeted metabolomics analysis was employed to explore the mechanisms underlying the alleviated post-acidification by sonication-assisted fermentation during storage. Metabolomic profiling revealed that the bioactive components from pineapple peel extract significantly influenced the metabolism pathways of lactic acid bacteria particularly involving galactose metabolism, glycerophospholipid metabolism, closely associated with the acid production of the strains and the regulation of the post-acidification rates of yogurt during storage. These results confirmed the potential of ultrasound-assisted fermentation combined with the addition of pineapple dietary fiber to enhance yogurt quality, providing an innovative tool to develop future yogurt products with high marketability.

The giant anteater (Myrmecophaga tridactyla) is a toothless mammal that feeds mainly on termites and ants. Therefore, like other toothless mammals, this species has morphological and physiological adaptations of the salivary glands related to eating habits. Saliva is essential for the health of the oral cavity, chewing and lubrication of the mouth and it is constituted by an aqueous fluid containing electrolytes, enzymes, and glycoproteins which play an important role in modulating the oral microbiota. The present study investigated the morphology, glycan pattern and the aquaporin 5 (AQP5) expression in the giant anteater mandibular gland.