Construction of an artificial phosphoketolase pathway that efficiently catabolizes multiple carbon sources to acetyl-CoA.

The canonical glycolysis pathway is responsible for converting glucose into 2 molecules of acetyl-coenzyme A (acetyl-CoA) through a cascade of 11 biochemical reactions. Here, we have designed and constructed an artificial phosphoketolase (APK) pathway, which consists of only 3 types of biochemical reactions. The core enzyme in this pathway is phosphoketolase, while phosphatase and isomerase act as auxiliary enzymes. The APK pathway has the potential to achieve a 100% carbon yield to acetyl-CoA from any monosaccharide by integrating a one-carbon condensation reaction. We tested the APK pathway in vitro, demonstrating that it could efficiently catabolize typical C1-C6 carbohydrates to acetyl-CoA with yields ranging from 83% to 95%. Furthermore, we engineered Escherichia coli stain capable of growth utilizing APK pathway when glycerol act as a carbon source. This novel catabolic pathway holds promising route for future biomanufacturing and offering a stoichiometric production platform using multiple carbon sources.

Evaluation and optimization of six adsorbents for removal of tetracycline from swine wastewater: Experiments and response surface analysis.

The removal of tetracycline antibiotics using adsorbents is becoming an environmentally friendly and cost-effective method. This study systematically analyzed the stability, structure, morphology, and chemical properties of various adsorbents. Batch adsorption experiments (pH, time, temperature, tetracycline concentration, and adsorbent dosage) were conducted to compare the adsorption capacity of the six adsorbents (biochar, activated carbon, montmorillonite, zeolite, chitosan, and polymerized aluminum chloride) for tetracycline removal. The results indicated that montmorillonite had the highest adsorption efficiency, followed by biochar, with chitosan showing the lowest efficiency. At an adsorbent dose of 25 g/L and an initial tetracycline concentration of 120 mg/L, the removal rates of tetracycline by montmorillonite, biochar, and chitosan were 97.6%, 69.3%, and 12.2%, respectively. Furthermore, the removal rate of tetracycline by biochar, following the response surface methodology optimal mode, increased by 5.5%. The Elovich model was better suited to explain the adsorption process of tetracycline compared to the conventional pseudo-first kinetic model and second-order kinetic model. The isothermal adsorption model suggested that both chemisorption and physisorption occurred in all removal processes, in which chemisorption dominated. Tetracycline was efficiently adsorbed through the combined effects of pore filling, electrostatic attraction, π-π interactions, and complexation reactions of surface functional groups. Additionally, montmorillonite demonstrated superior performance as an adsorbent for tetracycline removal from swine wastewater compared to the other adsorbents studied.

Swimming exercise activates peroxisome proliferator-activated receptor-alpha and mitigates age-related renal fibrosis in rats.

Aging results in progressive decline of renal function as well as histological alterations including glomerulosclerosis and interstitial fibrosis. The objective of current study was to test the benefits of moderate swimming exercise in aged rats on renal function and structure and investigate its molecular mechanisms. Aged rats of 21-months old were given moderate swimming exercise for 12 weeks. Swimming exercise in aged rats led to reduced plasma levels of creatinine and blood urea nitrogen. Periodic acid-Schiff staining results revealed reduced renal injury scores in aged rats after swimming exercise. Swimming exercise in aged rats mitigated renal fibrosis and downregulated the mRNA expression of Acta2, Fn, Col1a, Col4a, and Tgfb1 in kidneys. Swimming exercise in aged rats attenuated lipid accumulation and reduced levels of triglyceride in kidneys. Swimming exercise in aged rats abated oxidative stress, evidenced by reduced MDA levels and increased MnSOD activities in kidneys. Swimming exercise in aged rats inhibited NF-κB activities and reduced renal expression of pro-inflammatory cytokines including MCP-1, IL-1ß and IL-6. Mechanistically, swimming exercise restored mRNA and protein expression of PPAR-α in kidney of aged rats. Furthermore, swimming exercise in aged rats increased expression of PPAR-α-targeting microRNAs including miR-21 and miR-34a. Collectively, swimming exercise activated PPAR-α, which partly explained the benefits of moderate swimming exercise in aging kidneys.

ame-miR-34 Modulates the Larval Body Weight and Immune Response of Apis mellifera Workers to Ascosphara apis Invasion.

MiRNAs are critical regulators of numerous physiological and pathological processes. Ascosphaera apis exclusively infects bee larvae and causes chalkbrood disease. However, the function and mechanism of miRNAs in the bee larval response to A. apis infection is poorly understood. Here, ame-miR-34, a previously predicted miRNA involved in the response of Apis mellifera larvae to A. apis invasion, was subjected to molecular validation, and overexpression and knockdown were then conducted to explore the regulatory functions of ame-miR-34 in larval body weight and immune response. Stem-loop RT-PCR and Sanger sequencing confirmed the authenticity of ame-miR-34 in the larval gut of A. mellifera. RT-qPCR results demonstrated that compared with that in the uninfected larval guts, the expression level of ame-miR-34 was significantly downregulated (p < 0.001) in the guts of A. apis-infected 4-, 5-, and 6-day-old larvae, indicative of the remarkable suppression of host ame-miR-34 due to A. apis infection. In comparison with the corresponding negative control (NC) groups, the expression level of ame-miR-34 in the larval guts in the mimic-miR-34 group was significantly upregulated (p < 0.001), while that in the inhibitor-miR-34 group was significantly downregulated (p < 0.01). Similarly, effective overexpression and knockdown of ame-miR-34 were achieved. In addition, the body weights of 5- and 6-day-old larvae were significantly increased compared with those in the mimic-NC group; the weights of 5-day-old larvae in the inhibitor-miR-34 group were significantly decreased in comparison with those in the inhibitor-NC group, while the weights of 4- and 6-day-old larvae in the inhibitor-miR-34 group were significantly increased, indicating the involvement of ame-miR-34 in modulating larval body weight. Furthermore, the expression levels of both hsp and abct in the guts of A. apis-infected 4-, 5-, and 6-day-old larvae were significantly upregulated after ame-miR-34 overexpression. In contrast, after ame-miR-34 knockdown, the expression levels of the aforementioned two key genes in the A. apis-infected 4-, 5-, and 6-day-old larval guts were significantly downregulated. Together, the results demonstrated that effective overexpression and knockdown of ame-miR-34 in both noninfected and A. apis-infected A. mellifera larval guts could be achieved by the feeding method, and ame-miR-34 exerted a regulatory function in the host immune response to A. apis invasion through positive regulation of the expression of hsp and abct. Our findings not only provide a valuable reference for the functional investigation of bee larval miRNAs but also reveal the regulatory role of ame-miR-34 in A. mellifera larval weight and immune response. Additionally, the results of this study may provide a promising molecular target for the treatment of chalkbrood disease.

Systematic Characterization and Regulatory Role of lncRNAs in Asian Honey Bees Responding to Microsporidian Infestation.

Long noncoding RNAs (lncRNAs) are pivotal regulators in gene expression and diverse biological processes, such as immune defense and host-pathogen interactions. However, little is known about the roles of lncRNAs in the response of the Asian honey bee (Apis cerana) to microsporidian infestation. Based on our previously obtained high-quality transcriptome datasets from the midgut tissues of Apis cerana cerana workers at 7 days post inoculation (dpi) and 10 dpi with Nosema ceranae (AcT7 and AcT10 groups) and the corresponding un-inoculated midgut tissues (AcCK7 and AcCK10 groups), the transcriptome-wide identification and structural characterization of lncRNAs were conducted, and the differential expression pattern of lncRNAs was then analyzed, followed by investigation of the regulatory roles of differentially expressed lncRNAs (DElncRNAs) in host response. Here, 2365, 2322, 2487, and 1986 lncRNAs were, respectively, identified in the AcCK7, AcT7, AcCK7, and AcT10 groups. After removing redundant ones, a total of 3496 A. c. cerana lncRNAs were identified, which shared similar structural characteristics with those discovered in other animals and plants, such as shorter exons and introns than mRNAs. Additionally, 79 and 73 DElncRNAs were screened from the workers' midguts at 7 dpi and 10 dpi, respectively, indicating the alteration of the overall expression pattern of lncRNAs in host midguts after N. ceranae infestation. These DElncRNAs could, respectively, regulate 87 and 73 upstream and downstream genes, involving a suite of functional terms and pathways, such as metabolic process and Hippo signaling pathway. Additionally, 235 and 209 genes co-expressed with DElncRNAs were found to enrich in 29 and 27 terms, as well as 112 and 123 pathways, such as ABC transporters and the cAMP signaling pathway. Further, it was detected that 79 (73) DElncRNAs in the host midguts at 7 (10) dpi could target 321 (313) DEmiRNAs and further target 3631 (3130) DEmRNAs. TCONS_00024312 and XR_001765805.1 were potential precursors for ame-miR-315 and ame-miR-927, while TCONS_00006120 was the putative precursor for both ame-miR-87-1 and ame-miR-87-2. These results together suggested that DElncRNAs are likely to play regulatory roles in the host response to N. ceranae infestation through the regulation of neighboring genes via a cis-acting effect, modulation of co-expressed mRNAs via trans-acting effect, and control of downstream target genes' expression via competing endogenous RNA networks. Our findings provide a basis for disclosing the mechanism underlying DElncRNA-mediated host N. ceranae response and a new perspective into the interaction between A. c. cerana and N. ceranae.

Unveiling the circRNA-Mediated Immune Responses of Western Honey Bee Larvae to Ascosphaera apis Invasion.

Western honey bee (Apis mellifera), a eusocial insect with a superior economic and ecological value, is widely used in the beekeeping industry throughout the world. As a new class of non-coding RNAs (ncRNAs), circular RNAs (circRNAs) participate in the modulation of considerable biological processes, such as the immune response via diverse manners. Here, the identification, characteristic investigation, and molecular verification of circRNAs in the Apis mellifera ligustica larval guts were conducted, and the expression pattern of larval circRNAs during the Ascosphaera apis infection was analyzed, followed by the exploration of the potential regulatory part of differentially expressed circRNAs (DEcircRNAs) in host immune responses. A total of 2083 circRNAs in the larval guts of A. m. ligustcia were identified, with a length distribution ranging from 106 nt to 92,798 nt. Among these, exonic circRNAs were the most abundant type and LG1 was the most distributed chromosome. Additionally, 25, 14, and 30 up-regulated circRNAs as well as 26, 25, and 62 down-regulated ones were identified in the A. apis-inoculated 4-, 5-, and 6-day-old larval guts in comparison with the corresponding un-inoculated larval guts. These DEcircRNAs were predicted to target 35, 70, and 129 source genes, which were relative to 12, 23, and 20 GO terms as well as 11, 10, and 27 KEGG pathways, including 5 cellular and humoral immune pathways containing apoptosis, autophagy, endocytosis, MAPK, Toll, and Imd signaling pathways. Furthermore, complex competing endogenous RNA (ceRNA) regulatory networks were detected to be formed among DEcircRNAs, DEmiRNAs, and DEmRNAs. The Target DEmRNAs were engaged in 24, 20, and 25 functional terms as well as 62, 80, and 159 pathways, including several vital immune defense-associated pathways, namely the lysosome, endocytosis, phagosome, autophagy, apoptosis, MAPK, Jak-STAT, Toll, and Imd signaling pathways. Finally, back-splicing sites within 15 circRNAs and the difference in the 9 DEcircRNAs' expression between un-inoculated and A. apis-inoculated larval guts were confirmed utilizing molecular methods. These findings not only enrich our understanding of bee host-fungal pathogen interactions, but also lay a foundation for illuminating the mechanism underlying the DEcircRNA-mediated immune defense of A. m. ligustica larvae against A. apis invasion.

Spatiotemporal variations and influencing factors of methane emissions from livestock in China: A spatial econometric analysis.

In recent years, China has been implementing policies to improve the livestock industry in response to the global trend toward green and low-carbon development. These policies include the establishment of demonstration zones for high-standard agriculture, the relocation of farms to the north, etc. This study aims to investigate the impact of changes in the spatial structure of the livestock industry on methane emissions. It used panel data from 31 provinces in China from 2001 to 2021 and applied the IPCC methodology to quantify methane emissions at both the national and provincial levels. In addition, a spatial econometric model was used to analyze the impact of changes in the spatial structure of the livestock industry on methane emissions. The results show that methane from livestock in China decreased from 13.85 million tons in 2001 to 11.82 million tons in 2021. In addition, methane emissions from livestock in China show a significant spatial gradient and correlation. The Southwest has the highest methane emissions, accounting for 24 % of the total emissions. After controlling for spatial correlation and other factors in the model, it was found that the spatial structure of the livestock industry has a different influence on methane emissions both in the province and in neighboring provinces. To improve methane emission efficiency in the future, policies such as establishing functional zones for livestock farming, strengthening technological innovation and sharing for green development in agriculture, and promoting the optimization of agricultural and rural management structures should be implemented.

Redesigning glycolaldehyde synthase for the synthesis of biorefinery feedstock D-xylulose from C1 compounds.

Global climate deterioration intensifies the demand for exploiting efficient CO2 utilization approaches. Converting CO2 to biorefinery feedstock affords an alternative strategy for third-generation biorefineries. However, upcycling CO2 into complex chiral carbohydrates remains a major challenge. Previous attempts at sugar synthesis from CO2 either produce mixtures with poor stereoselectivity or require ATP as a cofactor. Here, by redesigning glycolaldehyde synthase, the authors constructed a synthetic pathway for biorefinery feedstock D-xylulose from CO2 that does not require ATP as a cofactor. The artificial D-xylulose pathway only requires a three-step enzyme cascade reaction to achieve the stereoselective synthesis of D-xylulose at a concentration of 1.2 g L-1. Our research opens up an alternative route toward future production of chemicals and fuels from CO2.

Characterization of ribostamycin and its impurities using a nano-quantity analyte detector: Systematic comparison of performance among three different aerosol detectors.

Characterization of aminoglycoside antibiotics like ribostamycin is important due to the complex composition and common toxic impurities. Aerosol detectors are often employed for determination of these non-absorbent analytes. In this work, a robust and cost-effective method was developed for simultaneous detection of ribostamycin and its related substances using high-performance liquid chromatography (HPLC) with a relative new aerosol detector named nano-quantity analyte detector (NQAD). With the introduction of less toxic but more compatible ion-pairs pentafluoropropionic acid (PFPA) and trifluoroacetic acid (TFA) in the eluent, an optimized separation effect was achieved. Compared with the other two aerosol detectors namely ELSD (evaporative light scattering detector) and CAD (charged aerosol detector), method verification and quantitative detection results revealed that NQAD had higher sensitivity than ELSD with a 0.8 µg/mL limit of detection, as well as wider linear range (from 2 µg/mL to 1000 µg/mL) than both CAD (from 2 µg/mL to 200 µg/mL) and ELSD (from 8 µg/mL to 200 µg/mL) detector. The performance of NQAD helped to realize detection of ribostamycin and its impurities with significant concentration differences in a single run. With a cation suppressor to eliminate the ion-suppression caused by the ion-pairs in the eluent, the structure of nine impurities in ribostamycin sample was characterized by liquid chromatography-mass spectrum (LC-MS). Both external standard and area normalization calculation were investigated, and NQAD obtained more accurate results due to its full-range linear response-to-concentration relationship, providing an alternative for routine quality control of multi analyte systems.

Association of ultraprocessed food consumption with risk of rheumatoid arthritis: a retrospective cohort study in the UK Biobank.

BACKGROUND: Limited studies explored the association between consumption of ultraprocessed food (UPF) and rheumatoid arthritis (RA). OBJECTIVES: This study aimed to examine the association between UPF consumption and RA risk and explore the potential mediating effects of RA-related biomarkers. METHODS: This retrospective cohort study included 207,012 participants without RA at recruitment and completed 24-h dietary recalls. UPF was defined based on the NOVA food classification system. Incident RA was ascertained using the International Classification of Diseases version 10. Cox regression models were used to examine the association between UPF consumption and the incidence of RA. Additionally, mediation analyses were conducted to evaluate the contribution of biomarkers related to the lipid profile, systemic inflammatory factors, serum liver enzymes, and glucose metabolism to the observed associations. RESULTS: The participants' mean (standard deviation [SD]) age at recruitment was 56.08 (7.95) y. During a median follow-up of 12.24 (interquartile range: 11.66-13.03) y, 1869 RA events were recorded. Compared with the lowest quintile of UPF consumption (weight percentage of the UPF), the adjusted hazard ratio (HR) of RA in the highest quintile was 1.17 (95% confidence interval (CI): 1.01, 1.36). There was a 6% elevated risk of RA incidence per SD increase in UPF intake (HR: 1.06; 95% CI: 1.01, 1.11). In the mediation analyses, the biomarkers explained 3.07%-14.80% of the association between UPF intake and RA. CONCLUSIONS: Higher UPF consumption was associated with an increased risk of RA, which may be mediated by inflammation, lipids, and liver enzymes. Lower UPF consumption is recommended to reduce RA incidence.

Lactoferrin ameliorated obesity-induced endothelial dysfunction by inhibiting the Tak1/IL-18/eNOS pathway between PVAT and vascular endothelium.

Vascular endothelial dysfunction (ED) is one of the mechanisms underlying obesity-related hypertension. Perivascular adipose tissue (PVAT) surrounds blood vessels and influences the vascular endothelium function. Previous studies have demonstrated the antihypertensive effects of lactoferrin (LF) and its hydrolysates through various mechanisms. However, the effect of LF on ED and PVAT has not yet been investigated. In this study, we examined the influence of LF on ED and PVAT using high-fat diet mice as well as MAEC cells and 3T3-L1 adipocytes. Finally, LF supplementation decreases the systolic blood pressure (SBP), serum adhesion molecule (ICAM-1 and VCAM-1), and aorta ROS levels, and improves endothelium-dependent relaxation function in high-fat diet mice. Moreover, LF supplementation down-regulates the Tak1/IL-18/eNOS pathway between PVAT and aorta and enhances the NO generation in high-fat diet mice. In addition, we observe that LF decreases the expression levels of IL-18 and p-Tak1 in 3T3-L1 adipocytes, but fails to influence the eNOS and p-eNOS expression levels in MAEC cells. Finally, the significant associations between LF and IL-18 and SBP and hypertension risk are also observed in obesity children only. These findings provide evidence that the Tak1/IL-18/eNOS pathway between the aorta and PVAT is important in obesity-related ED, and LF may improve ED or even hypertension by down-regulating this pathway.

Expression Profile, Regulatory Network, and Putative Role of microRNAs in the Developmental Process of Asian Honey Bee Larval Guts.

MiRNAs, as a kind of key regulators in gene expression, play vital roles in numerous life activities from cellular proliferation and differentiation to development and immunity. However, little is known about the regulatory manner of miRNAs in the development of Asian honey bee (Apis cerana) guts. Here, on basis of our previously gained high-quality transcriptome data, transcriptome-wide identification of miRNAs in the larval guts of Apis cerana cerana was conducted, followed by investigation of the miRNAs' differential expression profile during the gut development. In addition to the regulatory network, the potential function of differentially expressed miRNAs (DEmiRNAs) was further analyzed. In total, 330, 351, and 321 miRNAs were identified in the 4-, 5-, and 6-day-old larval guts, respectively; among these, 257 miRNAs were shared, while 38, 51, and 36 ones were specifically expressed. Sequences of six miRNAs were confirmed by stem-loop RT-PCR and Sanger sequencing. Additionally, in the "Ac4 vs. Ac5" comparison group, there were seven up-regulated and eight down-regulated miRNAs; these DEmiRNAs could target 5041 mRNAs, involving a series of GO terms and KEGG pathways associated with growth and development, such as cellular process, cell part, Wnt, and Hippo. Comparatively, four up-regulated and six down-regulated miRNAs detected in the "Ac5 vs. Ac6" comparison group and the targets were associated with diverse development-related terms and pathways, including cell, organelle, Notch and Wnt. Intriguingly, it was noticed that miR-6001-y presented a continuous up-regulation trend across the developmental process of larval guts, implying that miR-6001-y may be a potential essential modulator in the development process of larval guts. Further investigation indicated that 43 targets in the "Ac4 vs. Ac5" comparison group and 31 targets in the "Ac5 vs. Ac6" comparison group were engaged in several crucial development-associated signaling pathways such as Wnt, Hippo, and Notch. Ultimately, the expression trends of five randomly selected DEmiRNAs were verified using RT-qPCR. These results demonstrated that dynamic expression and structural alteration of miRNAs were accompanied by the development of A. c. cerana larval guts, and DEmiRNAs were likely to participate in the modulation of growth as well as development of larval guts by affecting several critical pathways via regulation of the expression of target genes. Our data offer a basis for elucidating the developmental mechanism underlying Asian honey bee larval guts.

Effect of Ascosphaera apis Infestation on the Activities of Four Antioxidant Enzymes in Asian Honey Bee Larval Guts.

Ascosphaera apis infects exclusively bee larvae and causes chalkbrood, a lethal fungal disease that results in a sharp reduction in adult bees and colony productivity. However, little is known about the effect of A. apis infestation on the activities of antioxidant enzymes in bee larvae. Here, A. apis spores were purified and used to inoculate Asian honey bee (Apis cerana) larvae, followed by the detection of the host survival rate and an evaluation of the activities of four major antioxidant enzymes. At 6 days after inoculation (dpi) with A. apis spores, obvious symptoms of chalkbrood disease similar to what occurs in Apis mellifera larvae were observed. PCR identification verified the A. apis infection of A. cerana larvae. Additionally, the survival rate of larvae inoculated with A. apis was high at 1−2 dpi, which sharply decreased to 4.16% at 4 dpi and which reached 0% at 5 dpi, whereas that of uninoculated larvae was always high at 1~8 dpi, with an average survival rate of 95.37%, indicating the negative impact of A. apis infection on larval survival. As compared with those in the corresponding uninoculated groups, the superoxide dismutase (SOD) and catalase (CAT) activities in the 5- and 6-day-old larval guts in the A. apis−inoculated groups were significantly decreased (p < 0.05) and the glutathione S-transferase (GST) activity in the 4- and 5-day-old larval guts was significantly increased (p < 0.05), which suggests that the inhibition of SOD and CAT activities and the activation of GST activity in the larval guts was caused by A. apis infestation. In comparison with that in the corresponding uninoculated groups, the polyphenol oxidase (PPO) activity was significantly increased (p < 0.05) in the 5-day-old larval gut but significantly reduced (p < 0.01) in the 6-day-old larval gut, indicating that the PPO activity in the larval guts was first enhanced and then suppressed. Our findings not only unravel the response of A. cerana larvae to A. apis infestation from a biochemical perspective but also offer a valuable insight into the interaction between Asian honey bee larvae and A. apis.

Numerical and Experimental Study on the Direct Chill Casting of Large-Scale AA2219 Billets via Annular Coupled Electromagnetic Field.

The internal coupled electromagnetic melt treatment (ICEMT) method is firstly proposed to produce high-quality and large-sized aluminum alloy billets. A three-dimensional model was established to describe the ICEMT process of direct chill casting (DC casting). The effect of ICEMT on the fluid flow patterns and temperature field in the DC casting of ϕ880 mm AA2219 billets is numerically analyzed. Moreover, the mechanisms of the ICEMT process on grain refinement and macrosegregation were discussed. The calculated results indicate that the electromagnetic field appears to be coupled circinate at the cross section of the melt, the fluid flow becomes unstable accompanied by the bias flow, and the temperature profiles are significantly more uniform. An experimental verification was conducted and the results prove that compared with traditional direct chill casting, the microstructures of the AA2219 large-scale billet under the ICEMT process are uniform and fine.

Comprehensive assessment of heavy metals in soil-crop system based on PMF and evolutionary game theory.

The traditional assessment of farmland environmental quality usually focuses on soil heavy metals, but ignores agricultural produce safety. It is urgent to comprehensively assess the effects of farmland environmental quality based on soil quality and produce safety. To fill this gap, the comprehensive assessment method was improved based on previous studies, which was used to assess the pollution level of heavy metals in soil-crop system of Shenyang, Liaoning Province, Northeast China. In addition, this study also made a comprehensive analysis of pollution sources based on positive matrix factorization (PMF) model, and discussed soil-crop system income stability by evolutionary game theory. The mean concentrations of As, Cd, Cr, Hg, Pb, Cu, Zn, and Ni in soil exceeded the corresponding Shenyang soil background values (5.68 %, 14.36 %, 57.61 %, 7.86 %, 30.32 %, 5.21 %, 211.72 %, 171.88 %). The results showed that about 28.28 % of paired soil-crop points were polluted by heavy metals, especially rice-soil points. Furthermore, heavy metals in crops may be transmitted less from soil and more from other environmental media. The PMF analysis results showed that there were six pollution sources in study area, and the major contributor of pollution were agricultural activities, traffic-related activities, and industrial activities. In farmland environment protection, the only stable strategy is soil-crop system, and soil-crop system is better than the benefits of single soil or crop from the perspective of benefits. This study provides a scientific and reliable method to combine soil quality with produce safety to assess the risk of heavy metals in farmland.

Iridescent chiral nematic papers based on cellulose nanocrystals with multiple optical responses for patterned coatings.

Chiral nematic papers (CNPs) with mesopores structure based on cellulose nanocrystals (CNCs) were fabricated successfully via a swelling and freeze-drying method. The order of the original chiral nematic cellulose nanocrystals film was preserved in CNPs, which was proved by scanning electron microscopy (SEM), polarized optical microscopy (POM) measurements and circular dichroism (CD) spectra. The CNPs exhibited excellent optical responsive properties to different solvents. Inspired by this feature, a colorable ink containing amounts of gel particles was prepared by pulverizing CNPs/water mixture into a suspension. Patterns written in suspension ink with various colors can be formed when soaked with different solvents. Moreover, CNPs displayed an irreversible color response to compression. Additionally, the hydrophilicity of CNPs was tuned by polyethyleneimine. Modified CNPs exhibited different colors under the identical solvent environment when compared to the original one. Aqueous PEI can be used as an ink to depict responsive photonic patterns on CNPs.

Comprehensive assessment of harmful heavy metals in contaminated soil in order to score pollution level.

Soil-related problems have grown up to be a major threat to human society. Scientific evaluation is helpful to understand the status of soil pollution and provide reference to further work. In this situation, Liaoning Province, a typical industrial and agricultural province in Northeast China, was selected as a case study region. It reviewed 200 studies published between 2010 and 2020 and recorded related data of soil heavy metal. It used model method and index method to evaluate the agricultural region. The comprehensive assessment score of Liaoning pollution level was 0.8998. Dalian was 0.9536, ranking first among the 14 cities. Huludao and Jinzhou were 0.7594 respectively, ranked the last. Heavy metal accumulation in different cities stemmed from different sources, including weathering of parent materials, industrial wastes, sewage irrigation, and mining activities. In general, the pollution level of heavy metal in Liaoning was at low risk level, but it still needs to pay attention to the health risk of heavy metal and the input of heavy metal into the soil, especially cadmium (Cd). This study provides a comprehensive assessment of soil heavy metal pollution in Liaoning, while identifying policy recommendations for pollution mitigation and environmental management.

Transcriptome-Wide Characterization of piRNAs during the Developmental Process of European Honey-Bee Larval Guts.

piRNAs play pivotal roles in maintaining genome stability, regulating gene expression, and modulating development and immunity. However, there are few piRNA-associated studies on honey-bees, and the regulatory role of piRNAs in the development of bee guts is largely unknown. Here, the differential expression pattern of piRNAs during the developmental process of the European honey-bee (Apis mellifera) larval guts was analyzed, followed by investigation of the regulatory network and the potential function of differentially expressed piRNAs (DEpiRNAs) in regulating gut development. A total of 843 piRNAs were identified in the larval guts of A. mellifera; among these, 764 piRNAs were shared by 4- (Am4 group), 5- (Am5 group), and 6-day-old (Am6 group) larval guts, while 11, 67, and one, respectively, were unique. The first base of piRNAs in each group had a cytosine (C) bias. Additionally, 61 up-regulated and 17 down-regulated piRNAs were identified in the "Am4 vs. Am5" comparison group, further targeting 9, 983 genes, which were involved in 50 GO terms and 142 pathways, while two up-regulated and five down-regulated piRNAs were detected in the "Am5 vs. Am6" comparison group, further targeting 1, 936 genes, which were engaged in 41 functional terms and 101 pathways. piR-ame-742536 and piR-ame-856650 in the "Am4 vs. Am5" comparison group as well as piR-ame-592661 and piR-ame-31653 in the "Am5 vs. Am6" comparison group were found to link to the highest number of targets. Further analysis indicated that targets of DEpiRNAs in these two comparison groups putatively regulate seven development-associated signaling pathways, seven immune-associated pathways, and three energy metabolism pathways. Moreover, the expression trends of five randomly selected DEpiRNAs were verified based on stem-loop RT-PCR and RT-qPCR. These results were suggestive of the overall alteration of piRNAs during the larval developmental process and demonstrated that DEpiRNAs potentially modulate development-, immune-, and energy metabolism-associated pathways by regulating the expression of corresponding genes via target binding, further affecting the development of A. mellifera larval guts. Our data offer a novel insight into the development of bee larval guts and lay a basis for clarifying the underlying mechanisms.

Numerical assessment of the passivator effectiveness for Cd-contaminated soil remediation.

A highly effective, economical, and reliable remedial technology is imperative for the successful remediation of [1] cadmium (Cd)-contaminated soil. Although certain Cd passivators have been found to be effective, the methods of assessing their effectiveness are very limited and rarely studied. This study aimed to develop a practical score method for assessing the remedial effectiveness of the Cd passivator. Ultimately, 16 evaluation indexes, 36 weight coefficients, 16 utility functions, and an evaluation system set were obtained. The repair effect of passivator was analysed according to four aspects: metal pollution, soil fertility, passivator cost-effectiveness, and crop profit. The numerical score scale ranged from 0 to 1, with a higher score being indicative of higher remedial effectiveness. There were five repair levels: level 1-5. Level 1 was optimal, and level 5 the poorest. In addition, this study suggested and designed the structure of a passivator database composed of soil information, the remediation effectiveness of the passivator, and the evaluation method. This study provides more comprehensive and insightful information to guide improved soil remediation and soil contamination control.

Facile One-Step Deposition of Ag Nanoparticles on SiO2 Electrospun Nanofiber Surfaces for Label-Free SERS Detection and Antibacterial Dressing.

The fabrication of highly active and free-standing surface-enhanced Raman scattering (SERS) substrates in a simple and low-cost manner has been a crucial and urgent challenge in recent years. Herein, SiO2 nanofiber substrates modified with size-tunable Ag nanoparticles were prepared by the combination of electrospinning and in situ chemical reduction. The results demonstrate the presence and uniform adsorption of Ag nanoparticles on the SiO2 matrix surface. The free-standing composite nanofibrous substrates show high-performance SERS response toward 4-mercaptophenol and 4-mercaptobenzoic acid, and the detection limit can be as low as 10-10 mol/L. Most importantly, the as-prepared substrate as a versatile SERS platform can realize label-free detection of bio-macromolecules of bacteria, i.e., Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Furthermore, the substrates also possess outstanding antibacterial activities against S. aureus and E. coli. Briefly, the significance of this study is that size-tunable Ag nanoparticles can be decorated on SiO2 nanofiber surfaces with triethanolamine as a bridging and reducing agent through a one-pot reaction, and the as-prepared nanofibrous membranes are expected to act as a candidate for label-free SERS detection as well as antibacterial dressing.