RESUMO
The sources of fluids and metals in porphyry systems of continental-collision settings are poorly constrained. Mercury isotopes display unique mass-independent fractionation (expressed as Δ199Hg) and may provide important constraints on metal and volatile sources given that Hg is a highly volatile metal. Here, we report Hg isotope data on ore-forming porphyries, barren magmatic rocks, and mantle-derived mafic magmas from southern Tibet. The fertile porphyries and coeval mafic magmas display mainly positive Δ199Hg values (up to +0.25 per mil), while Δ199Hg values in barren magmatic rocks and mafic magmas are largely negative (-0.54 to 0.00 per mil). The positive Δ199Hg values observed here are consistent with seawater and marine sediments, suggesting that the ultimate source of fluids involved in the genesis of post-subduction porphyry copper deposits was the mantle lithosphere metasomatized by previous oceanic plate subduction. Our Hg isotope data provide an alternative view to current metallogenetic models on collisional porphyry systems that focus on melting of the lower continental crust.
RESUMO
Whereas the genesis of carbonatitic rare earth element (REE) deposits has long been a focus of study, the controls on mobilization and mineralization of REEs during magmatic-hydrothermal processes still remain open to debate. Here, we present our investigation of the dissolution and crystallization of REE (fluor)carbonate minerals in alkaline carbonate brine-melts up to 850°C and 11.6 kbar. Our results show that REEs are soluble in Na2CO3 brine-melts, achieving concentrations exceeding 8 weight % at temperatures above 650°C. The addition of calcium and/or fluoride has minimal impact on REE mobilization, whereas introduction of silica suppresses REE solubilities by half, due to britholite formation above 550°C. Upon cooling, sodium and REEs combine to crystallize in burbankite or carbocernaite in sodium-enriched brine-melts, even at fluoride saturation. However, while the brine-melts contain substantial ferro- or aluminosilicate, REE mineralization in fluorcarbonates occurs after sufficient sodium precipitation in alkaline silicate minerals, hence revealing how silicate and sodium carbonate govern REE mineralization.
RESUMO
BACKGROUND: Primary cervical cancer screening and treating precancerous lesions are effective ways to prevent cervical cancer. However, the coverage rates of human papillomavirus (HPV) vaccines and routine screening are low in most developing countries and even some developed countries. This study aimed to explore the benefit of an artificial intelligence-assisted cytology (AI) system in a screening program for a cervical cancer high-risk population in China. METHODS: A total of 1231 liquid-based cytology (LBC) slides from women who underwent colposcopy at the Chinese PLA General Hospital from 2018 to 2020 were collected. All women had received a histological diagnosis based on the results of colposcopy and biopsy. The sensitivity (Se), specificity (Sp), positive predictive value (PPV), negative predictive value (NPV), false-positive rate (FPR), false-negative rate (FNR), overall accuracy (OA), positive likelihood ratio (PLR), negative likelihood ratio (NLR) and Youden index (YI) of the AI, LBC, HPV, LBC + HPV, AI + LBC, AI + HPV and HPV Seq LBC screening strategies at low-grade squamous intraepithelial lesion (LSIL) and high-grade squamous intraepithelial lesion (HSIL) thresholds were calculated to assess their effectiveness. Receiver operating characteristic (ROC) curve analysis was conducted to assess the diagnostic values of the different screening strategies. RESULTS: The Se and Sp of the primary AI-alone strategy at the LSIL and HSIL thresholds were superior to those of the LBC + HPV cotesting strategy. Among the screening strategies, the YIs of the AI strategy at the LSIL + threshold and HSIL + threshold were the highest. At the HSIL + threshold, the AI strategy achieved the best result, with an AUC value of 0.621 (95% CI, 0.587-0.654), whereas HPV testing achieved the worst result, with an AUC value of 0.521 (95% CI, 0.484-0.559). Similarly, at the LSIL + threshold, the LBC-based strategy achieved the best result, with an AUC of 0.637 (95% CI, 0.606-0.668), whereas HPV testing achieved the worst result, with an AUC of 0.524 (95% CI, 0.491-0.557). Moreover, the AUCs of the AI and LBC strategies at this threshold were similar (0.631 and 0.637, respectively). CONCLUSIONS: These results confirmed that AI-only screening was the most authoritative method for diagnosing HSILs and LSILs, improving the accuracy of colposcopy diagnosis, and was more beneficial for patients than traditional LBC + HPV cotesting.
Assuntos
Inteligência Artificial , Detecção Precoce de Câncer , Infecções por Papillomavirus , Neoplasias do Colo do Útero , Humanos , Feminino , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/virologia , Neoplasias do Colo do Útero/patologia , Adulto , Detecção Precoce de Câncer/métodos , Pessoa de Meia-Idade , Infecções por Papillomavirus/diagnóstico , Infecções por Papillomavirus/virologia , Colposcopia , China/epidemiologia , Sensibilidade e Especificidade , Displasia do Colo do Útero/diagnóstico , Displasia do Colo do Útero/virologia , Displasia do Colo do Útero/patologia , Displasia do Colo do Útero/epidemiologia , Adulto Jovem , Curva ROC , Citodiagnóstico/métodosRESUMO
Micro-nanobubbles (MNBs) can form reactive oxygen species (ROS) with high oxidizing potential. In this study, nickel-doped metal-organic framework materials (MOFs) capable of activating molecular oxygen were synthesized using trivalent arsenic (As(III)) as a target pollutant and combined with peroxymonosulfate (PMS) to construct a MOF/MNB/PMS system. The results included the rapid oxidation of As(III), the successful absorption of oxidized As(V), and finally the efficient removal of As. The effects of pH, amount of PMS used, and preparation time of MNBs on the As removal performance of the MOF/MNB/PMS system were investigated experimentally. The changes in the properties of the materials before and after the reaction were analyzed by XPS, and it was found that the main active sites on the surface of the MOFs were the metal elements and the pyridine nitrogen near the carbon atom. The regular morphology and elemental composition of the MOFs were determined by TEM scanning and EDS test, which indicated the presence of nickel. XRD tests before and after the reaction showed that the MOFs were structurally stable. The results of the free radical burst experiments show that the single linear oxygen (1O2) is the main active substance in the system, and that the MNBs are key factors by which the system achieves efficient oxidation performance. In addition to providing a sustainable supply of molecular oxygen to the MOFs during the reaction process, coupling the MNBs with PMS was found to improve the oxidation capacity of the system. The results of this study thus provide a new concept for As removal and advanced oxidation in water bodies.
Assuntos
Arsênio , Estruturas Metalorgânicas , Níquel , Poluentes Químicos da Água , Níquel/química , Estruturas Metalorgânicas/química , Poluentes Químicos da Água/química , Arsênio/química , Purificação da Água/métodos , Oxirredução , Água/químicaRESUMO
Selective catalytic NH3-to-N2 oxidation (NH3-SCO) is highly promising for abating NH3 emissions slipped from stationary flue gas after-treatment devices. Its practical application, however, is limited by the non-availability of low-cost catalysts with high activity and N2 selectivity. Here, using defect-rich nitrogen-doped carbon nanotubes (NCNT-AW) as the support, we developed a highly active and durable copper-based NH3-SCO catalyst with a high abundance of cuprous (Cu+) sites. The obtained Cu/NCNT-AW catalyst demonstrated outstanding activity with a T50 (i.e. the temperature to reach 50% NH3 conversion) of 174°C in the NH3-SCO reaction, which outperformed not only the Cu catalyst supported on N-free O-functionalized CNTs (OCNTs) or NCNT with less surface defects, but also those most active Cu catalysts in open literature. Reaction kinetics measurements and temperature-programmed surface reactions using NH3 as a probe molecule revealed that the NH3-SCO reaction on Cu/NCNT-AW follows an internal selective catalytic reaction (i-SCR) route involving nitric oxide (NO) as a key intermediate. According to mechanistic investigations by X-ray photoelectron spectroscopy, Raman spectroscopy, and X-ray absorption spectroscopy, the superior NH3-SCO performance of Cu/NCNT-AW originated from a synergy of surface defects and N-dopants. Specifically, surface defects promoted the anchoring of CuO nanoparticles on N-containing sites and, thereby, enabled efficient electron transfer from N to CuO, increasing significantly the fraction of SCR-active Cu+ sites in the catalyst. This study puts forward a new idea for manipulating and utilizing the interplay of defects and N-dopants on carbon surfaces to fabricate Cu+-rich Cu catalysts for efficient abatement of slip NH3 emissions via selective oxidation.
Assuntos
Amônia , Cobre , Oxirredução , Cobre/química , Amônia/química , Catálise , Nanotubos de Carbono/química , Poluentes Atmosféricos/química , Temperatura , Modelos QuímicosRESUMO
Neuropeptides are involved in many biological processes in insects. However, it is unclear what role neuropeptides play in Spodoptera litura adaptation to phytochemical flavone. In this study, 63 neuropeptide precursors from 48 gene families were identified in S. litura, including two neuropeptide F genes (NPFs). NPFs played a positive role in feeding regulation in S. litura because knockdown of NPFs decreased larval diet intake. S. litura larvae reduced flavone intake by downregulating NPFs. Conversely, the flavone intake was increased if the larvae were treated with NPF mature peptides. The NPF receptor (NPFR) was susceptible to the fluctuation of NPFs. NPFR mediated NPF signaling by interacting with NPFs to regulate the larval diet intake. In conclusion, this study suggested that NPF signaling regulated diet intake to promote S. litura adaptation to flavone, which contributed to understanding insect adaptation mechanisms to host plants and provide more potential pesticidal targets for pest control.
Assuntos
Proteínas de Insetos , Larva , Neuropeptídeos , Spodoptera , Animais , Spodoptera/fisiologia , Spodoptera/metabolismo , Neuropeptídeos/metabolismo , Neuropeptídeos/genética , Neuropeptídeos/química , Larva/crescimento & desenvolvimento , Larva/metabolismo , Larva/química , Proteínas de Insetos/metabolismo , Proteínas de Insetos/genética , Proteínas de Insetos/química , Flavonas/metabolismo , Flavonas/química , Comportamento Alimentar , Sequência de AminoácidosRESUMO
BACKGROUND: Long-term ozone (O3) exposure has been associated with cardiovascular disease (CVD) mortality in mounting cohort evidence, yet its relationship with incident CVD was poorly understood, especially in low- and middle-income countries (LMICs) experiencing high ambient air pollution. METHODS: We carried out a nationwide perspective cohort study from 2010 through 2018 by dynamically enrolling 36948 participants across Chinese mainland. Warm-season (April-September) O3 concentrations were estimated using satellite-based machine-learning models with national coverage. Cox proportional hazards model with time-varying exposures was employed to evaluate the association of long-term O3 exposure with incident CVD (overall CVD, hypertension, stroke, and coronary heart disease [CHD]). Assuming causality, a counterfactual framework was employed to estimate O3-attributable CVD burden based on the exposure-response (E-R) relationship obtained from this study. Decomposition analysis was utilized to quantify the contributions of four key direct driving factors (O3 exposure, population size, age structure, and incidence rate) to the net change of O3-related CVD cases between 2010 and 2018. RESULTS: A total of 4428 CVD, 2600 hypertension, 1174 stroke, and 337 CHD events were reported during 9-year follow-up. Each 10-µg/m³ increase in warm-season O3 was associated with an incident risk of 1.078 (95% confidence interval [CI]: 1.050-1.106) for overall CVD, 1.098 (95% CI: 1.062-1.135) for hypertension, 1.073 (95% CI: 1.019-1.131) for stroke, and 1.150 (95% CI: 1.038-1.274) for CHD, respectively. We observed no departure from linear E-R relationships of O3 exposure with overall CVD (Pnonlinear= 0.22), hypertension (Pnonlinear= 0.19), stroke (Pnonlinear= 0.70), and CHD (Pnonlinear= 0.44) at a broad concentration range of 60-160 µg/m3. Compared with rural dwellers, those residing in urban areas were at significantly greater O3-associated incident risks of overall CVD, hypertension, and stroke. We estimated 1.22 million (10.6% of overall CVD in 2018) incident CVD cases could be attributable to ambient O3 pollution in 2018, representing an overall 40.9% growth (0.36 million) compared to 2010 (0.87 million, 9.7% of overall CVD in 2010). This remarkable rise in O3-attributable CVD cases was primary driven by population aging (+24.0%), followed by increase in O3 concentration (+10.5%) and population size (+6.7%). CONCLUSIONS: Long-term O3 exposure was associated with an elevated risk and burden of incident CVD in Chinese adults, especially among urban dwellers. Our findings underscored policy priorities of implementing joint control measures for fine particulate matter and O3 in the context of accelerated urbanization and population aging in China.
Assuntos
Poluentes Atmosféricos , Doenças Cardiovasculares , Exposição Ambiental , Ozônio , Humanos , Ozônio/análise , China/epidemiologia , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/induzido quimicamente , Pessoa de Meia-Idade , Masculino , Exposição Ambiental/efeitos adversos , Feminino , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/toxicidade , Incidência , Estudos de Coortes , Idoso , Adulto , Poluição do Ar/efeitos adversos , Poluição do Ar/análiseRESUMO
Metabolic alternation is a typical characteristic of insecticide resistance in insects. However, mechanisms underlying metabolic alternation and how altered metabolism in turn affects insecticide resistance are largely unknown. Here, we report that nicotinamide levels are decreased in the imidacloprid-resistant strain of Nilaparvata lugens, may due to reduced abundance of the symbiotic bacteria Arsenophonus. Importantly, the low levels of nicotinamide promote imidacloprid resistance via metabolic detoxification alternation, including elevations in UDP-glycosyltransferase enzymatic activity and enhancements in UGT386B2-mediated metabolism capability. Mechanistically, nicotinamide suppresses transcriptional regulatory activities of cap 'n' collar isoform C (CncC) and its partner small muscle aponeurosis fibromatosis isoform K (MafK) by scavenging the reactive oxygen species (ROS) and blocking the DNA binding domain of MafK. In imidacloprid-resistant N. lugens, nicotinamide deficiency re-activates the ROS/CncC signaling pathway to provoke UGT386B2 overexpression, thereby promoting imidacloprid detoxification. Thus, nicotinamide metabolism represents a promising target to counteract imidacloprid resistance in N. lugens.
Assuntos
Hemípteros , Inseticidas , Animais , Inseticidas/toxicidade , Espécies Reativas de Oxigênio , Neonicotinoides , Nitrocompostos/toxicidade , Transdução de Sinais , Isoformas de Proteínas , NiacinamidaRESUMO
Polyvinyl alcohol (PVA) with abundant hydroxyl groups (-OH) has been widely used for membranes, hydrogels, and films, and its function is largely affected by the alcoholysis degree. Therefore, the development of rapid and accurate methods for alcoholysis degree determination in PVAs is important. In this contribution, we have proposed a novel fluorescence-based platform for probing the alcoholysis degree of PVA by using the (E)-N-(4-methoxyphenyl)-1-(quinolin-2-yl)methanimine (QPM)-Zn2+ complex as the reporter. The mechanism study disclosed that the strong coordination between -OH and Zn2+ induced the capture of the QPM-Zn2+ complex and promoted its subsequent immobilization into the noncrystalline area. The immobilization of the QPM-Zn2+ complex restricted its molecular rotation and reduced the nonirradiative transition, thus yielding bright emissions. In addition, the practical applications of this proposed method were further validated by the accurate alcoholysis degree determination of blind PVA samples with the confirmation of the National Standard protocol. It is expected that the developed fluorescence approach in this work might become an admissive strategy for screening the alcoholysis degree of PVA.
RESUMO
Efficient detoxification is the key factor for phytophagous insect to adapt to phytochemicals. However, the role of uridine diphosphate (UDP)-glycosyltransferases (UGTs) in insect anti-defense to phytochemical flavone is largely unknown. In this study, 52 UGT genes were identified in Spodoptera litura and they presented evident gene duplication. UGT played a crucial part in larval tolerance to flavone because the enzyme activity and transcriptional level of 77 % UGT members were remarkably upregulated by flavone administration and suppression of UGT enzyme activity and gene expressions significantly increased larval susceptibility to flavone. Bacteria coexpressing UGTs had high survival rates under flavone treatment and flavone was dramatically metabolized by UGT recombinant cells, which indicated the involvement of UGTs in flavone detoxification. What's more, ecdysone pathway was activated by flavone. Topical application of 20-hydroxyecdysone highly upregulated UGT enzyme activity and more than half of UGT expressions. The effects were opposite when ecdysone receptor (EcR) and ultraspiracle (USP)-mediated ecdysone signaling pathway was inhibited. Furtherly, promoter reporter assays of 5 UGT genes showed that their transcription activities were notably increased by cotransfection with EcR and USP. In consequence, this study suggested that UGTs were involved in flavone detoxification and their transcriptional expressions were regulated by ecdysone pathway.
Assuntos
Flavonas , Glicosiltransferases , Animais , Glicosiltransferases/metabolismo , Difosfato de Uridina , Spodoptera/genética , Ecdisona , Insetos/metabolismo , Compostos Fitoquímicos , Flavonas/farmacologiaRESUMO
In a sustainable economy, each firm perceives different levels of carbon risk, but there are few studies on the relationship between a firm's carbon risk perception and Environmental, Social, and Governance (ESG) performance. This paper examines the impact of firm-level carbon risk perception on ESG performance using Chinese A-share listed firms during 2011-2020. We find a positive relationship between firm-level perception of carbon risk and firm ESG performance. Further analysis shows that analyst coverage and media attention exert a substantial moderating effect on the link between carbon risk perception and ESG performance. We identify three channels through which carbon risk perception affects ESG performance. First, rising carbon risk perception enables firms to take measures to reduce pollutants and greenhouse gas emissions and increases environmental (E) scores. Second, this perception encourages firms to take responsibility for social employment and increases social (S) scores. Finally, it improves firm sustainable governance and further increases governance (G) scores. Our research has an important guiding role in promoting firm ESG practice.
Assuntos
Poluentes Ambientais , Carbono , PercepçãoRESUMO
Spiders are representative arthropods of adaptive radiation. The high-quality genomes have only been reported in several web weaver spider species, leaving the wandering spiders' genomic information scarce. The pond wolf spider, Pardosa pseudoannulata, is a representative species in the retrolateral titial apophysis (RTA) clade. We present a chromosome-level P. pseusoannulata genome assembly of 2.42 Gb in size with a scaffold N50 of 169.99 Mb. Hi-C scaffolding assigns 94.83% of the bases to 15 pseudo-chromosomes. The repeats account for 52.79% of the assembly. The assembly includes 96.2% of the complete arthropod universal single-copy orthologs. Gene annotation predicted 24,530 protein-coding genes with a BUSCO score of 95.8% complete. We identified duplicate clusters of Hox genes and an expanded cuticle protein gene family with 243 genes. The expression patterns of CPR genes change in response to environmental stresses such as coldness and insecticide exposure. The high-quality P. pseudoannulata genome provides valuable information for functional and comparative studies in spiders.
Assuntos
Animais Peçonhentos , Artrópodes , Genoma de Inseto , Aranhas , Animais , Cromossomos/genética , Aranhas/genéticaRESUMO
BACKGROUND: Cohort evidence linking long-term ozone (O3) exposure to mortality remained largely mixed worldwide and was extensively deficient in densely-populated Asia. This study aimed to assess the long-term effects of O3 exposure on all-cause mortality among Chinese adults, as well as to examine potential regional heterogeneity across the globe. METHODS: A national dynamic cohort of 42153 adults aged 16+ years were recruited from 25 provinces across Chinese mainland and followed up during 2010-2018. Annual warm-season (April-September) O3 and year-round co-pollutants (i.e., nitrogen dioxide [NO2] and fine particulate matter [PM2.5]) were simulated through validated spatial-temporal prediction models and were assigned to each enrollee in each calendar year. Cox proportional hazards models with time-varying exposures were employed to assess the O3-mortality association. Concentration-response (C-R) curves were fitted by natural cubic spline function to investigate the potential nonlinear association. Both single-pollutant model and co-pollutant models additionally adjusting for PM2.5 and/or NO2 were employed to examine the robustness of the estimated association. The random-effect meta-analysis was adopted to pool effect estimates from the current and prior population-based cohorts (n = 29), and pooled C-R curves were fitted through the meta-smoothing approach by regions. RESULTS: The study population comprised of 42153 participants who contributed 258921.5 person-years at risk (median 6.4 years), of whom 2382 death events occurred during study period. Participants were exposed to an annual average of 51.4 ppb (range: 22.7-74.4 ppb) of warm-season O3 concentration. In the single-pollutant model, a significantly increased hazard ratio (HR) of 1.098 (95% confidence interval [CI]: 1.023-1.179) was associated with a 10-ppb rise in O3 exposure. Associations remained robust to additional adjustments of co-pollutants, with HRs of 1.099 (95% CI: 1.023-1.180) in bi-pollutant model (+PM2.5) and 1.093 (95% CI: 1.018-1.174) in tri-pollutant model (+PM2.5+NO2), respectively. A J-shaped C-R relationship was identified among Chinese general population, suggesting significant excess mortality risk at high ozone exposure only. The combined C-R curves from Asia (n = 4) and North America (n = 17) demonstrated an overall increased risk of all-cause mortality with O3 exposure, with pooled HRs of 1.124 (95% CI: 0.966-1.307) and 1.023 (95% CI: 1.007-1.039) per 10-ppb rise, respectively. Conversely, an opposite association was observed in Europe (n = 8, HR: 0.914 [95% CI: 0.860-0.972]), suggesting significant heterogeneity across regions (P < 0.01). CONCLUSIONS: This study provided national evidence that high O3 exposure may curtail long-term survival of Chinese general population. Great between-region heterogeneity of pooled O3-mortality was identified across North America, Europe, and Asia.