Noncanonical Condensation of Nucleic Acid Chains by Hydrophobic Gold Nanocrystals.

Nucleic acid condensates are essential for various biological processes and have numerous applications in nucleic acid nanotechnology, gene therapy, and mRNA vaccines. However, unlike the in vivo condensation that is dependent on motor proteins, the in vitro condensation efficiency remains to be improved. Here, we proposed a hydrophobic interaction-driven mechanism for condensing long nucleic acid chains using atomically precise hydrophobic gold nanoclusters (Au NCs). We found that hydrophobic Au NCs could condense long single-stranded DNA or RNA to form composites of spherical nanostructures, which further assembled into bead-shaped suprastructures in the presence of excessive Au NCs. Thus, suprastructures displayed gel-like behaviors, and Au NCs could diffuse freely inside the condensates, which resemble the collective motions of condensin complexes inside chromosomes. The dynamic hydrophobic interactions between Au NCs and bases allow for the reversible release of nucleic acids in the presence of mild triggering agents. Our method represents a significant advancement toward the development of more efficient and versatile nucleic acid condensation techniques.

Cervical disc arthroplasty for magnetic resonance-evident cervical spondylotic myelopathy: comparison with anterior cervical discectomy and fusion.

OBJECTIVE: Anterior cervical discectomy and fusion (ACDF) is a standard surgical approach for cervical spondylotic myelopathy (CSM) caused by disc herniations. Although cervical disc arthroplasty (CDA) has become, in the past decade, a viable alternative to ACDF in selected patients, the differences among patients with CSM treated with CDA and ACDF remain elusive. The effectiveness of motion preservation devices in CSM is also unclear. METHODS: Adult patients who underwent 1- or 2-level CDA or ACDF between 2007 and 2021 were retrospectively reviewed. Patients whose preoperative T2-weighted MRI demonstrated increased intramedullary signal intensity (IISI) were included and analyzed for the following: comparison of the length of IISI on pre- and postoperative MR images as well as range of motion (ROM) at the indexed levels between the CDA and ACDF groups. Measurement for clinical outcomes included the visual analog scale (VAS) of the arm and neck, the Neck Disability Index, and modified Japanese Orthopaedic Association scores. Perioperative clinical data were also compared between the two groups. RESULTS: A total of 122 patients were allocated to the CDA group and 108 to the ACDF group, with mean follow-ups of 46.6 and 39.0 months, respectively. Patients in the CDA group were younger than those in the ACDF group (47.64 ± 12.40 vs 61.73 ± 12.25 years, p < 0.001) (mean ± SD). The ACDF group had more 2-level surgery compared to the CDA group (p = 0.002). Both groups had significant regression of IISI on postoperative MRI compared to that of preoperative imaging (CDA: 1.23 ± 0.84 to 0.28 ± 0.39 cm; ACDF: 1.07 ± 0.60 to 0.37 ± 0.42 cm; both p < 0.001). The decrease in the length of IISI was similar between the two groups (p = 0.058). The postoperative ROM was well preserved in the CDA group (superior to ACDF, which yielded minimal ROM postoperatively). Both the CDA and ACDF groups demonstrated improvement in Neck Disability Index and modified Japanese Orthopaedic Association scores at 24 months postoperatively. The CDA group had significant improvements on VAS scores, whereas the improvement did not reach significance for the ACDF group at 24 months postoperatively. CONCLUSIONS: Significant shortening of IISI on T2-weighted MRI was demonstrated after both CDA and ACDF. At 24 months postoperatively, all clinical outcomes demonstrated improvement after both strategies, except that the VAS score was not significantly improved for ACDF. Therefore, CDA is a safe and effective option for patients with MR-evident CSM.

Prenylated C6-C3 derivatives from the root of Illicium ternstroemioides with antiviral activity.

Six previously undescribed prenylated C6-C3 derivatives (1-6) were isolated from the root of Illicium ternstroemioides A. C. Smith. Their structures were elucidated based on extensive spectroscopic analyses (UV, IR, 1D and 2D NMR, and HRESIMS). The absolute configurations of 1-3 were determined using electronic circular dichroism (ECD), and Mo2(OAc)4 induced circular dichroism (ICD). Compound 3 exhibited weak activity against Coxsackievirus B3 with an IC50 value of 33.3 µM, and compound 5 exhibited more potent activity against Coxsackievirus B3 with an IC50 value of 6.4 µM.

Recent advances on natural colorants-based intelligent colorimetric food freshness indicators: fabrication, multifunctional applications and optimization strategies.

With the increasing concerns of food safety and public health, tremendous efforts have been concentrated on the development of effective, reliable, nondestructive methods to evaluate the freshness level of different kinds of food. Natural colorants-based intelligent colorimetric indicators which are typically constructed with natural colorants and polymer matrices has been regarded as an innovative approach to notify the customers and retailers of the food quality during the storage and transportation procedure in real-time. This review briefly elucidates the mechanism of natural colorants used for intelligent colorimetric indicators and fabrication methodologies of natural colorants-based food freshness indicators. Subsequently, their multifunctional applications in intelligent food packaging systems like antioxidant packaging, antimicrobial packaging, biodegradable packaging, UV-blocking packaging and inkless packaging are well introduced. This paper also summarizes several optimizing strategies for the practical application of this advanced technology from different perspectives. Strategies like adopting a hydrophobic matrix, constructing double-layer film and encapsulation have been developed to improve the stability of the indicators. Co-pigmentation, metal ion complexation, pigment-mixing and using substrates with high surface area are proved to be effective to enhance the sensitivity of the indicators. Approaches include multi-index evaluation, machine learning and smartphone-assisted evaluation have been proven to improve the accuracy of the intelligent food freshness indicators. Finally, future research opportunities and challenges are proposed. Based on the fundamental understanding of natural colorants-based intelligent colorimetric food freshness indicators, and the latest research and findings from literature, this review article will help to develop better, lower cost and more reliable food freshness evaluation technique for modern food industry.

Human Endocrine-Disrupting Effects of Phthalate Esters through Adverse Outcome Pathways: A Comprehensive Mechanism Analysis.

Phthalate esters (PAEs) are widely exposed in the environment as plasticizers in plastics, and they have been found to cause significant environmental and health hazards, especially in terms of endocrine disruption in humans. In order to investigate the processes underlying the endocrine disruption effects of PAEs, three machine learning techniques were used in this study to build an adverse outcome pathway (AOP) for those effects on people. According to the results of the three machine learning techniques, the random forest and XGBoost models performed well in terms of prediction. Subsequently, sensitivity analysis was conducted to identify the initial events, key events, and key features influencing the endocrine disruption effects of PAEs on humans. Key features, such as Mol.Wt, Q+, QH+, ELUMO, minHCsats, MEDC-33, and EG, were found to be closely related to the molecular structure. Therefore, a 3D-QSAR model for PAEs was constructed, and, based on the three-dimensional potential energy surface information, it was discovered that the hydrophobic, steric, and electrostatic fields of PAEs significantly influence their endocrine disruption effects on humans. Lastly, an analysis of the contributions of amino acid residues and binding energy (BE) was performed, identifying and confirming that hydrogen bonding, hydrophobic interactions, and van der Waals forces are important factors affecting the AOP of PAEs' molecular endocrine disruption effects. This study defined and constructed a comprehensive AOP for the endocrine disruption effects of PAEs on humans and developed a method based on theoretical simulation to characterize the AOP, providing theoretical guidance for studying the mechanisms of toxicity caused by other pollutants.

Novel chlorin e6-based conjugates of tyrosine kinase inhibitors: Synthesis and photobiological evaluation as potent photosensitizers for photodynamic therapy.

Since tyrosine kinase inhibitor (TKI) could reverse ABCG2-mediated drug-resistance, novel chlorin e6-based conjugates of Dasatinib and Imatinib as photosensitizer (PS) were designed and synthesized. The results demonstrated that conjugate 10b showed strongest phototoxicity against HepG2 and B16-F10 cells, which was more phototoxic than chlorin e6 and Talaporfin. It could reduce efflux of intracellular PS by inhibiting ABCG2 in HepG2 cells, and localize in mitochondria, lysosomes, golgi and ER, resulting in higher cell apoptosis rate and ROS production than Talaporfin. Moreover, it could induce cell autophagy and block cell cycle in S phase, and significantly inhibit tumor growth and prolong survival time on BALB/c nude mice bearing HepG2 xenograft tumor to a greater extent than chlorin e6. Consequently, compound 10b could be applied as a promising candidate PS due to its good water-solubility and stability, low drug-resistance, high quantum yield of 1O2 and excellent antitumor efficacy in vitro and in vivo.

Characteristics, differential diagnosis, individualized treatment, and prevention of hyperhomocysteinemia in newborns.

OBJECTIVES: This study aimed to investigate the incidence rate, clinical phenotype, gene variation spectrum, and prognosis of neonatal hyperhomocysteinemia (HHcy) and explore its diagnosis, individualised treatment, and prevention strategies. METHODS: We screened 84722 neonates for HHcy using liquid chromatography-tandem mass spectrometry (LC-MS/MS) combined with biochemical detection, urine gas chromatography-mass spectrometry (GC-MS), and next-generation sequencing (NGS) for gene analysis to comprehensively differentiate and diagnose diseases. RESULTS: 18 children (P1-P18) were diagnosed with methylmalonic acidemia (MMA) and HHcy, and fourteen known and one new variant of the MMACHC gene were found. Five children showed poor mental reactions, brain dysplasia, lethargy, hyperbilirubinemia, and jaundice, whereas the other 13 children had no evident abnormalities. These children were all cobalamin- and folic acid-reactive types, and they were mainly supplemented with cobalamin, L-carnitine, betaine, and folic acid. The mother of P12 had a prenatal diagnosis at the next pregnancy; the results showed that MMACHC gene was not pathogenic and she gave birth to a healthy baby. One child (P19) was diagnosed with methylenetetrahydrofolate reductase (MTHFR) deficiency, and one new mutation was detected in the MTHFR gene. Patient P19 showed congenital brain dysplasia, neonatal anaemia, and hyperbilirubinemia, and treatment consisted mainly of betaine and cobalamin supplementation. One child (P20) was confirmed to have methionine adenosyltransferase I (MAT I) deficiency but had no clinical manifestations. After treatment, all the children had a good prognosis. CONCLUSION: The incidence of neonatal HHcy in the Zibo area was 1/4236, and the common pathogenic variants were c.609G>A, c.80A>G, and c.482G>A in the MMACHC gene. Patients with HHcy can achieve a good prognosis if pathogenic factors and targeted treatment are identified. Gene analysis and prenatal diagnosis contribute to the early prevention of HHcy.

Dual role of caspase 8 in adipocyte apoptosis and metabolic inflammation.

Caspases are cysteine-aspartic proteases that were initially discovered to play a role in apoptosis. However, caspase 8, in particular, also has additional non-apoptotic roles, such as in inflammation. Adipocyte cell death and inflammation are hypothesized to be initiating pathogenic factors in type 2 diabetes. Here, we examined the pleiotropic role of caspase 8 in adipocytes and obesity-associated insulin resistance. Caspase 8 expression was increased in adipocytes from mice and humans with obesity and insulin resistance. Treatment of 3T3-L1 adipocytes with caspase 8 inhibitor Z-IETD-FMK decreased both death receptor-mediated signaling and targets of NF-κBsignaling. We generated novel adipose tissue and adipocyte-specific caspase 8 knockout mice (aP2Casp8-/- and adipoqCasp8-/-). Both males and females had improved glucose tolerance in the setting of high fat diet (HFD) feeding. Knockout mice also gained less weight on HFD, with decreased adiposity, adipocyte size and hepatic steatosis. These mice had decreased adipose tissue inflammation and decreased activation of canonical and non-canonical NF-κB signaling. Furthermore, they demonstrated increased energy expenditure, core body temperature, and UCP1 expression. Adipocyte-specific activation of Ikbkb or housing mice at thermoneutrality attenuated improvements in glucose tolerance. These data demonstrate an important role for caspase 8 in mediating adipocyte cell death and inflammation to regulate glucose and energy homeostasis.

CD7 targeted "off-the-shelf" CAR-T demonstrates robust in vivo expansion and high efficacy in the treatment of patients with relapsed and refractory T cell malignancies.

T-cell acute lymphoblastic leukemia (T-ALL) represents an area of highly unmet medical needs. Once relapsed, patients have limited treatment options and poor prognosis. T-ALL antigens such as CD7 is extensively expressed in normal T cells and natural killer (NK) cells, and extending the success of CAR-T therapy to T cell malignancies was challenged by CAR-T cell fratricide, high production cost, and potential product contaminations. GC027 is an "off-the-shelf" allogeneic CD7 targeted CAR-T therapeutic product for T cell malignancies. It demonstrated superior cell expansion and antileukemia efficacy in mouse xenograft model. In our previous study, we observed promising efficacy results in the first two relapsed and refractory(R/R) T-ALL patients treated with GC027. In the expanded study, 11 out of 12 patients had rapid eradication of T-lymphoblasts and reached complete response within 1-month after GC027 infusion. GC027 cells expanded quickly beginning at infusion and reached to peak around 5-10 days after infusion. For most patients with a response(9/11), GC027 could not be detected via flow cytometry or qPCR 4 weeks after infusion. One patient had progression free survival of >3 years. With manageable toxicity profile, GC027 demonstrated superior clinical efficacy to standard chemotherapy regimens in (R/R) T cell malignancies.

Safety and efficacy of adding postbiotics in infant formula: a systematic review and meta-analysis.

Postbiotics, as emerging products, were added to infant formula, but their safety and efficacy are unclear. To clarify this issue, we wrote this meta-analysis. We searched PubMed, Embase, Web of Science and ProQuest from its establishment to February 2023. The review was registered on PROSPERO database (CRD42022352405). The effects of infant formula with and without postbiotics were compared, and the incidence of serious adverse events (SAEs), digestive symptoms, concentration of stool secretory immunoglobulin A (SIgA), and growth and development indexes were analyzed. Nine randomized controlled trials with 2065 participants were included. The addition of postbiotics to infant formula was found to increase the concentration of stool SIgA (P < 0.05) with very low certainty of evidence, without significantly impacting the incidence of SAEs, infantile colic, flatulence, diarrhea, vomiting, abdominal pain and gastrointestinal disorders, the daily weight gain, the total gain in body length and the daily head circumference gain (all P > 0.05). Adding postbiotics to the formula is safe for infants, which would not increase the incidence of SAEs, infantile colic, flatulence, diarrhea, vomiting, abdominal pain, and gastrointestinal disorders, and could increase the concentration of stool SIgA. IMPACT: Our study provides evidence that the addition of postbiotics to infant formula is safe but not effective. This is the first systematic review and meta-analysis of postbiotics. This study provides strong evidence for the safety of postbiotics and lays a foundation for related clinical trials.

FUNDC2, a mitochondrial outer membrane protein, mediates triple-negative breast cancer progression via the AKT/GSK3ß/GLI1 pathway.

Triple-negative breast cancer (TNBC) lacks effective therapeutic targets and has a poor prognosis, easy recurrence and metastasis. It is urgent and important to explore TNBC treatment targets. Through mass spectrometry combined with qRT-PCR validation in luminal A cells and TNBC cells, high-content screening and clinical sample analysis, FUNDC2 was discovered as a novel target. The function of the outer mitochondrial membrane protein FUNDC2 in breast cancer is still unclear. In this study, we find that FUNDC2 expression in TNBC tissues is significantly higher than that in luminal subtype breast cancer tissues. FUNDC2 silencing in TNBC cells significantly reduces cell proliferation, migration and invasion. As demonstrated in vivo using subcutaneous tumor xenografts in mice, FUNDC2 suppression significantly inhibits tumor growth. The underlying mechanism might be mediated by inactivating its downstream signal AKT/GSK3ß and GLI1, a key factor of the Hedgehog signaling pathway. Therefore, FUNDC2 may promote TNBC progression and provide a therapeutic target for treating TNBC.

Knockdown of PRMT1 suppresses the malignant biological behavior of osteosarcoma cells and increases cisplatin sensitivity via c-Myc-mediated BCAT1 downregulation.

Increasing evidence indicated that protein arginine methyltransferase-1 (PRMT1) is an oncogene in multiple malignant tumors, including osteosarcoma (OS). The aim of this study was to investigate the underlying mechanism of PRMT1 in OS. The effects of PRMT1 or BCAT1, branched-chain amino acid transaminase 1 (BCAT1) on OS cell proliferation, invasion, autophagy, and apoptosis in vitro were examined. Moreover, molecular control of PRMT1 on c-Myc or transactivation of BCAT1 on c-Myc was assessed by chromatin immunoprecipitation and quantitative reverse transcription PCR assays. The effects of PRMT1 in vivo were examined with a xenograft tumor model. The results showed that PRMT1 was potently upregulated in OS tissues and cells. Upregulation of PRMT1 markedly increased OS cell proliferation and invasion in vitro and reduced cell apoptosis, whereas PRMT1 silencing showed the opposite effects. Cisplatin, one of the most effective chemotherapeutic drugs, improved cell survival rate by inducing the expression of PRMT1 to downregulate the cisplatin sensitivity. Meanwhile, the cisplatin-induced upregulation of PRMT1 expression caused dramatically autophagy induction and autophagy-mediated apoptosis by inactivating the mTOR signaling pathway, which could be reversed by 3-methyladenine, an autophagy inhibitor, or PRMT1 silencing. PRMT1 could activate c-Myc transcription and increase c-Myc-mediated expression of BCAT1. Furthermore, BCAT1 overexpression counteracted the effects of PRMT1 knockdown on cell proliferation, invasion, and apoptosis. Of note, deficiency of PRMT1 suppressed tumor growth in vivo. PRMT1 facilitated the proliferation and invasion of OS cells, inhibited cell apoptosis, and decreased chemotherapy sensitivity through c-Myc/BCAT1 axis, which may become potential target in treating OS.

A multicenter retrospective analysis of patients with salivary gland carcinoma treated with postoperative radiotherapy alone or chemoradiotherapy.

BACKGROUND: The aim of this study was to interrogate if the use of postoperative chemoradiotherapy (POCRT) correlated with superior oncological outcomes for certain subgroups of patients with high-risk salivary gland carcinoma (SGC), compared with postoperative radiotherapy (PORT) alone. METHODS: This multicenter retrospective study included 411 patients with surgically resected SGC who underwent PORT (n = 263) or POCRT (n = 148) between 2000 and 2015. Possible correlations of clinical parameters with outcomes were examined using the Kaplan-Meier analysis and Cox proportional-hazards regression model. RESULTS: The median follow-up of survivors is 10.9 years. For the entire cohort, adding concurrent chemotherapy to PORT was not associated with OS, PFS, or LRC improvement. However, patients with nodal metastasis who underwent POCRT had significantly higher 10-year OS (46.2% vs. 18.2%, P = 0.009) and PFS (38.7% vs. 10.0%, P = 0.009) rates than those treated with PORT alone. The presence of postoperative macroscopic residual tumor (R2 resection) was identified as an independent prognosticator for inferior OS (P = 0.032), PFS (P = 0.001), and LRC (P = 0.007). Importantly, POCRT significantly correlated with higher 10-year LRC rates in patients with R2 resection (74.2% vs. 40.7%, P = 0.034) or adenoid cystic carcinoma (AdCC, 97.6% vs. 83.6%, P = 0.039). On multivariate analyses, the use of POCRT significantly predicted superior OS (P = 0.037) and PFS (P = 0.013) for node-positive patients and LRC for patients with R2 resection (P = 0.041) or AdCC (P = 0.005). CONCLUSIONS: For surgically resected SGC, POCRT was associated with improved long-term OS and PFS for patients with nodal metastasis and superior LRC for patients with R2 resection or AdCC.

Soil and vegetation characteristics during the formation of typical Ligularia virgaurea degraded grassland.

To understand the formation process of typical poisonous plant degraded grassland, we studied the cha-racteristics of vegetation and soil during the gradual expansion of Ligularia virgaurea into the native grassland of Qinghai-Tibet Plateau. The results showed that population density, plant height, coverage, and biomass of L. virgaurea increased during the formation of L. virgaurea degraded grassland. In comparison with native grassland, the degraded grassland had higher total aboveground biomass (113.9%), soil total nitrogen concentration (61.0%), NH4+-N (77.9%), organic carbon concentration (45.3%), available phosphorus concentration (78.8%) as well as soil microbial biomass carbon (42.1%) and nitrogen (47.4%), but lower NO3--N (40.1%) and species richness (28.5%) and aboveground biomass (45.7%) of other species beyond L. virgaurea. The extremely strong abilities of interspecific inhibition and morphological plasticity of L. virgaurea, as well as efficient nutrient accumulation and utilization were the keys to its successful expansion, which facilitated the formation of typical L. virgaurea degraded grassland.

A regional comparison of children's blood cadmium, lead, and mercury in rural, urban and industrial areas of six European countries, and China, Ecuador, and Morocco.

OBJECTIVES: The authors aimed to evaluate whether blood cadmium (B-Cd), lead (B-Pb) and mercury (B-Hg) in children differ regionally in 9 countries, and to identify factors correlating with exposure. MATERIAL AND METHODS: The authors performed a cross-sectional study of children aged 7-14 years, living in 2007-2008 in urban, rural, or potentially polluted ("hot spot") areas (ca. 50 children from each area, in total 1363 children) in 6 European and 3 non-European countries. The authors analyzed Cd, Pb, and total Hg in blood and collected information on potential determinants of exposure through questionnaires. Regional differences in exposure levels were assessed within each country. RESULTS: Children living near industrial "hot-spots" had B-Cd 1.6 (95% CI: 1.4-1.9) times higher in the Czech Republic and 2.1 (95% CI:1.6-2.8) times higher in Poland, as compared to urban children in the same countries (geometric means [GM]: 0.13 µg/l and 0.15 µg/l, respectively). Correspondingly, B-Pb in the "hot spot" areas was 1.8 (95% CI: 1.6-2.1) times higher than in urban areas in Slovakia and 2.3 (95% CI: 1.9-2.7) times higher in Poland (urban GM: 19.4 µg/l and 16.3 µg/l, respectively). In China and Morocco, rural children had significantly lower B-Pb than urban ones (urban GM: 64 µg/l and 71 µg/l, respectively), suggesting urban exposure from leaded petrol, water pipes and/or coal-burning. Hg "hot spot" areas in China had B-Hg 3.1 (95% CI: 2.7-3.5) times higher, and Ecuador 1.5 (95% CI: 1.2-1.9) times higher, as compared to urban areas (urban GM: 2.45 µg/l and 3.23 µg/l, respectively). Besides industrial exposure, traffic correlated with B-Cd; male sex, environmental tobacco smoke, and offal consumption with B-Pb; and fish consumption and amalgam fillings with B-Hg. However, these correlations could only marginally explain regional differences. CONCLUSIONS: These mainly European results indicate that some children experience about doubled exposures to toxic elements just because of where they live. These exposures are unsafe, identifiable, and preventable and therefore call for preventive actions. Int J Occup Med Environ Health. 2023;36(3):349-64.

Screening for Fungicide Efficacy in Controlling Blackleg Disease in Wasabi (Eutrema japonicum).

Blackleg disease is devastating for wasabi (Eutrema japonicum) production, occurring at any time and everywhere within the main production area of the Sichuan Province, China. There have been very few studies on the chemical control of this disease. In this study, we isolated and identified a local popular strain of the pathogen Plenodomus wasabiae. The isolated fungus strain caused typical disease spots on the leaves and rhizomes upon inoculation back to wasabi seedlings. The symptoms of blackleg disease developed very quickly, becaming visible on the second day after exposure to P. wasabiae and leading to death within one week. We then evaluated the efficacy of ten widely used fungicides to screen out effective fungicides. The efficacy of the tested fungicides was determined through mycelial growth inhibition on medium plates. As a result, tebuconazole and pyraclostrobin were able to inhibit the mycelial growth of P. wasabiae, and the most widely used dimethomorph in local production areas produced the lowest inhibition activity (13.8%). Nevertheless, the highest control efficacy of tebuconazole and pyraclostrobin on wasabi seedlings was only 47.48% and 39.03%, respectively. Generally, the control efficacy of spraying the fungicide before inoculation was better than that after inoculation. An increase in the application concentration of the two fungicides did not proportionately result in improved performance. We cloned the full-length sequence of sterol 14-demethylase (CYP51) and cytochrome B (CYTB) of which the mutations may contribute to the possible antifungalresistance. These two genes of the isolated fungus do not possess any reported mutations that lead to fungicide resistance. Previous studies indicate that there is a significant difference between fungicides in terms of the effectiveness of controlling blackleg disease; however, the control efficacy of fungicides is limited in blackleg control. Therefore, field management to prevent wound infection and unfavorable environmental conditions are more important than pesticide management.

Nitrogen transformation and its microbial mechanism under co-composting of biogas slurry with garden waste.

Large amount of garden waste is consecutively produced in China every year. The composting with urea and microbial inoculum makes it possible to dispose garden waste in large quantities. However, composting accompanies with serious nitrogen loss and environmental problems. The biogas slurry contains considerable nitrogen nutrients and microorganisms, which theoretically could be used as alternative to urea and bacteria to reduce nitrogen loss, respectively. We set up three treatments of biogas slurry + garden waste (GB), biogas slurry + garden waste + urea (GBU), and biogas slurry + garden waste + urea + microbial inoculum (GBUM) to investigate the decomposition, nitrogen conversion and nitrogen loss in the co-composting process. The results showed that the high tempe-rature period of GB treatment was longer and more stable compared to that of GBU and GBUM treatments. The pH and EC value of GB treatment would benefit composting process and generated products with the highest germination index (GI) (221.8%). In addition, NH3 and N2O emission rates in the GB treatment were 2.59 mg·kg-1·d-1 and 3.65 µg·kg-1·d-1, respectively, being 99.0% and 50.0% lower than that in the GBU treatment and 99.4% and 40.7% lower than that in the GBUM treatment. The results of δ18O vs. δ15NSP dual isotopocule plots approach analysis showed that the GB and GBU treatments were dominated by denitrification, and that the contribution of denitrification was higher in the GB treatment. In contrast, the GBUM treatment was dominated by nitrification. The degree of N2O reduction in GB treatment (83.7%) was higher than the other two treatments. It was clear that GB treatment had the best maturity and lowest nitrogen loss in all treatments by enhancing the N2O reduction process during denitrification to reduce N2O emission. In conclusion, the biogas slurry and garden wastes could be directly co-composted without the limitation of C/N and microbial addition. The co-composting method could protect the environment and save resources leading to the recycling of waste in actual production.

Effects of long-term fertilization patterns on bacterial community structure and soil nutrients in dryland of yellow soil.

Understanding the responses of soil bacterial community to long-term fertilization in dryland of yellow soil could provide theoretical basis for establishing scientific fertilization system and cultivating healthy soil. Based on a 25-year long-term fertilization experiment on yellow soil, we collected soil samples from 0-20 cm layer under different fertilization treatments: no fertilization (CK), balanced application of N, P and K fertilizers (NPK), single application of organic fertilizer (M), combined application of constant organic and inorganic fertilizer (MNPK), and 1/2 organic fertilizer instead of 1/2 chemical fertilizer (MNP). Illumina MiSeq high-throughput sequencing technology was used to examine the effects of different fertilization patterns on soil bacterial community structure and soil nutrient content. The main driving factors of soil bacterial community were explored. The results showed that soil pH and organic matter content under treatments with organic fertilizer increased by 11.4%-13.5% and 28.8%-52.0%, respectively, compared to that under NPK treatment. Long-term fertilization did not affect soil bacterial α diversity, but significantly affected soil bacterial ß diversity. Compared with CK and NPK treatment, treatments of M, MNP, and MNPK significantly changed soil bacterial community structure, and increased the relative abundance of Fusobacteria and Anaerobes. Four fertilization treatments increased the relative abundance of Bacteroidetes, and decreased the relative abundance of Actinomyces and Campylobacter, compared to CK. Soil pH was the most important factor affecting soil bacterial community structure. Fertilization-stimulated rare microbial taxa (Pumilomyces and Anaerobes) were more sensitive to changes in different environmental factors and were the main drivers of the formation of community versatility. In conclusion, organic fertilizer improved soil properties and fertility and changed soil bacterial community structure, which are conducive to cultivating healthy soil.

Characterization of atmospheric mercury from mercury-added product manufacturing using passive air samplers.

Although alternatives to mercury (Hg) are available in most products and industrial activities, Hg continues to be an ingredient in some products, including fluorescent lamps and electrical and electronic equipment (EEE). In this work, low-cost passive air samplers (PASs) were used to investigate the atmospheric Hg pollution in Zhongshan, a large industrial city and major hub of mercury-added product manufacturing in South China. The GEM concentrations in the atmosphere were measured for two weeks during the summer of 2019 at a total of 144 sites across Zhongshan. Comparison with the results of active sampling confirmed that the PASs yielded accurate and reliable gaseous elemental mercury (GEM) concentrations and were thus well-suited for multi-site field monitoring. The mean GEM concentrations in the areas with mercury-added product manufacturing activities (5.1 ± 0.4 ng m-3) were significantly higher than those in other parts of Zhongshan (1.5 ± 0.4 ng m-3), indicating that local releases, rather than regional transport, were responsible for the atmospheric Hg pollution. Elevated GEM concentrations (up to 11.4 ng m-3) were found in the vicinity of fluorescent lamp and EEE factories and workshops, indicating significant Hg vapor emissions, presumably from the outdated production technologies and non-standard operation by under-trained workers. The Hg emissions from mercury-added product manufacturing were estimated to be 0.06 and 7.8 t yr-1 for Zhongshan and China, respectively, based on the scales of fluorescent lamp and EEE production. The non-carcinogenic health risk of Zhongshan residents from inhalation and ingestion was judged acceptable, whereby the inhalation exposure in Hg-polluted areas exceeded that of dietary ingestion. These findings demonstrate that mercury-added product manufacturing still contributes notably to anthropogenic gaseous Hg releases in the industrial areas with intense mercury-added product manufacturing activities.