The contents of ten heavy metals (Cr, Hg, As, Pb, Ni, Cd, Ti, Cu, Zn and V) in 413 topsoil samples from Puning City, Guangdong Province, China were investigated. Obvious enrichment of Hg, As, Pb, Cd ...and Zn were presented, and the contents of Hg and As in 5.8% and 3.4% samples respectively were higher than the guideline values recommended by the Chinese Environmental Quality Standard for Soils. Chromium and V were presented no enrichment and no pollution. According to one-way analysis of variance, the mean contents of Hg, Pb, Cu and Zn in land for construction were significantly higher than farmland and natural vegetation, but the land use had no obvious effect on other heavy metals. Furthermore, the potential sources of ten heavy metals were identified and apportioned in combination with geostatistics, correlation analysis and positive matrix factorization model. The results were following as: a) Pb, Zn and Cu mainly origin from vehicle emission and atmosphere deposition, and the hotspots approximately distributed in the areas of intensive traffic and near main roads; b) Hg and Cd were derived to industrial activities related to pharmaceutical industries, the textile and dyeing industries and e-waste recycling industries, and high-value areas were mainly concentrated in the northeast of the urban area where the industrial parks have been distributed; c) Soil parent material (Jurassic shale) was the main source of Cr, Ni, V and Ti; d) As mainly came from agricultural inputs such as pesticides or herbicides, livestock and fertilizers. Meanwhile, the contributions of four sources were 33.08%, 24.04%, 27.11% and 15.77% of the total contribution, respectively.
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•Obvious enrichment of Hg, Cd, Pb and Zn were found in Puning soils.•Four sources of soil heavy metals were apportioned by geostatistics and PMF.•Vehicle emission and industrial activities were the main anthropogenic source.
Chemodivergent tandem radical cyclization offers exciting possibilities for the synthesis of structurally diverse cyclic compounds. Herein, we revealed a chemodivergent tandem cyclization of ...alkene‐substituted quinazolinones under metal‐ and base‐free conditions, this transformation is initiated by alkyl radicals produced from oxidant‐induced α‐C(sp3)−H functionalization of alkyl nitriles or esters. The reaction resulted in the selective synthesis of a series of mono‐ and di‐alkylated ring‐fused quinazolinones by modulating the loading of oxidant, reaction temperature, and reaction time. Mechanistic investigations show that the mono‐alkylated ring‐fused quinazolinones is constructed by the key process of 1,2‐hydrogen shift, whereas the di‐alkylated ring‐fused quinazolinones is mainly achieved through crucial steps of resonance and proton transfer. This protocol is the first example of remote second alkylation on the aromatic ring via α‐C(sp3)−H functionalization and difunctionalization achieved by association of two unsaturated bonds in radical cyclization.
A novel method for preparing mono‐ and di‐alkylated ring‐fused quinazolinones from alkene‐substituted quinazolinones via chemodivergent tandem radical cyclization under metal‐ and base‐free conditions has been established.
For shade‐intolerant plants, changes in light quality through competition from neighbors trigger shade avoidance syndrome (SAS): a series of morphological and physiological adaptations that are ...ultimately detrimental to plant health and crop yield. Phytochrome‐interacting factor 7 (PIF7) is a major transcriptional regulator of SAS in Arabidopsis; however, how it regulates gene expression is not fully understood. Here, we show that PIF7 directly interacts with the histone chaperone anti‐silencing factor 1 (ASF1). The ASF1‐deprived asf1ab mutant showed defective shade‐induced hypocotyl elongation. Histone regulator homolog A (HIRA), which mediates deposition of the H3.3 variant into chromatin, is also involved in SAS. RNA/ChIP‐sequencing analyses identified the role of ASF1 in the direct regulation of a subset of PIF7 target genes. Furthermore, shade‐elicited gene activation is accompanied by H3.3 enrichment, which is mediated by the PIF7‐ASF1‐HIRA regulatory module. Collectively, our data reveal that PIF7 recruits ASF1‐HIRA to increase H3.3 incorporation into chromatin to promote gene transcription, thus enabling plants to effectively respond to environmental shade.
Synopsis
In Arabidopsis, the transcription factor PIF7 plays a dominant role in ameliorating the impact shade conditions have on fitness. In this study, a PIF7‐ASF1‐HIRA regulatory module is found to mediate H3.3 incorporation at a subset of shade‐responsive loci, leading to shade‐induced gene expression and morphological adaptation.
PIF7 recruits the ASF1‐HIRA complex under shade conditions
ASF1 and HIRA positively regulate shade‐induced hypocotyl elongation and define changes in gene expression
Shade increases ASF1 and H3.3 enrichment in the chromatin of a subset of PIF7 target genes
A PIF7‐ASF1‐HIRA regulatory module is responsible for H3.3 incorporation in the shade
When an Arabidopsis plant grows in shade, the transcription factor PIF7 triggers the adaptive growth response by guiding H3.3 deposition via the histone chaperone ASF1.
Objective
Hepatitis B virus X protein (HBx) is a pivotal factor for HBV-induced hepatitis. Herein, we sought to investigate HBx-mediated NLR pyrin domain containing 3 (NLRP3) inflammasome activation ...and pyroptosis under oxidative stress.
Methods
The effect of HBx on the NLRP3 inflammasome was analyzed by enzyme-linked immunosorbent assays, quantitative reverse transcription-polymerase chain reaction, western blotting, and immunofluorescence in hepatic HL7702 cells. Pyroptosis was evaluated by western blotting, lactate dehydrogenase release, propidium iodide staining, and transmission electron microscopy. NLRP3 expression in the inflammasome from liver tissues was assessed by immunohistochemistry.
Results
In hydrogen peroxide (H
2
O
2
)-stimulated HL7702 cells, HBx triggered the release of pro-inflammatory mediators apoptosis-associated speck-like protein containing a CARD (ASC), interleukin (IL)-1β, IL-18, and high-mobility group box 1 (HMGB1); activated NLRP3; and initiated pro-inflammatory cell death (pyroptosis). HBx localized to the mitochondria, where it induced mitochondrial damage and production of mitochondrial reactive oxygen species (mitoROS). Treatment of HL7702 cells with a mitoROS scavenger attenuated HBx-induced NLRP3 activation and pyroptosis. Expression levels of NLRP3, ASC, and IL-1β in liver tissues from patients were positively correlated with HBV DNA concentration.
Conclusions
The NLRP3 inflammasome was activated by elevated mitoROS levels and mediated HBx-induced liver inflammation and hepatocellular pyroptosis under H
2
O
2
-stress conditions.
A high transition temperature (Tc) is essential for the practical application of ferroelectrics as electronic devices under extreme thermal conditions in the aerospace, automotive, and energy ...industries. In recent decades, the isotope effect and strain engineering are found to effectively modulate Tc; however, these strategies are limited to certain systems. Developing simple, universal, and practical methods to improve Tc has become an imminent challenge for expanding the applications of ferroelectrics. Here, by adopting a molecular design strategy involving H/F substitution on an organic–inorganic hybrid perovskite (1‐azabicyclo2.2.1heptane)CdCl3 at a Tc of 190 K, the successful synthesis of a multiaxial, ferroelectric hybrid perovskite (4‐fluoro‐1‐azabicyclo2.2.1heptane)CdCl3 is reported, which demonstrates a large spontaneous polarization of 11.2 µC cm−2 (greater than that of polyvinylidene difluoride) and a Tc of 419 K (greater than that of BaTiO3). This temperature enhancement (229 K) is the largest reported for molecular ferroelectrics, far exceeding the reported enhancements induced by the isotope effect and other techniques. This pioneering technique provides an effective and universal method for improving Tc in ferroelectrics and represents an important step toward the development of high‐performance ferroelectric technology.
From (1‐azabicyclo2.2.1heptane)CdCl3, a molecular design strategy of H/F substitution is applied to synthesize a multiaxial organic–inorganic hybrid perovskite ferroelectric (4‐fluoro‐1‐azabicyclo2.2.1heptane)CdCl3. The phase transition temperature is successfully increased from 190 to 419 K, which is a record enhancement of 229 K for molecular ferroelectrics, significantly outperforming those induced by the isotope effect and other techniques.
The development of hydrogen sensors is of paramount importance for timely leak detection and remains a crucial unmet need. Palladium‐based materials, well known as hydrogen sensors, still suffer from ...poisoning and deactivation. Here, a hybrid hydrogen sensor consisting of a Pd nanocluster (NC) film, a metal–organic framework (MOF), and a polymer, are proposed. The polymer coating, as a protection layer, endows the sensor with excellent H2 selectivity and CO‐poisoning resistance. The MOF serves as an interface layer between the Pd NC film and the polymer layer, which alters the nature of the interaction with hydrogen and leads to significant sensing performance improvements, owing to the interfacial electronic coupling between Pd NCs and the MOF. The strategy overcomes the shortcomings of retarded response speed and degraded sensitivity induced by the polymer coating of a Pd NC film–polymer hybrid system. This is the first exhibition of a hydrogen‐sensing enhancement mechanism achieved by engineering the electronic coupling between Pd and a MOF. The work establishes a deep understanding of the hydrogen‐sensing enhancement mechanism at the nanoscale and provides a feasible strategy to engineer next‐generation gas‐sensing nanodevices with superior sensing figures of merit via hybrid material systems.
A triple‐layer, Pd nanocluster (NC) film–metal organic framework (MOF)–polymer hybrid nanocomposite for H2 detection is proposed, which overcomes the established limitations of the Pd–polymer nanocomposite system. The coupling between Pd NCs and MOF appears to have a profound impact on the surface electronic states of the Pd NCs, leading to a faster response and enhanced sensitivity.
Background Although several studies have indicated that lipoprotein(a) is a useful prognostic predictor for patients following percutaneous coronary intervention (PCI), previous observations have ...somewhat been limited by either small sample size or short-term follow-up. Hence, this study aimed to evaluate the impact of lipoprotein(a) on long-term outcomes in a large cohort of stable coronary artery disease patients after PCI. Methods and Results In this multicenter and prospective study, we consecutively enrolled 4078 stable coronary artery disease patients undergoing PCI from March 2011 to March 2016. They were categorized according to both the median of lipoprotein(a) levels and lipoprotein(a) values of <15 (low), 15 to 30 (medium), and ≥30 mg/dL (high). All patients were followed up for occurrence of cardiovascular events, including cardiovascular death, nonfatal myocardial infarction, and stroke. During an average of 4.9 years of follow-up, 315 (7.7%) cardiovascular events occurred. The events group had significantly higher lipoprotein(a) levels than the nonevents group. Compared with the low lipoprotein(a) group, Kaplan-Meier analysis showed that the high lipoprotein(a) group had a significantly lower cumulative event-free survival rate, and multivariate Cox regression analysis further revealed that the high lipoprotein(a) group had significantly increased cardiovascular events risk. Moreover, adding continuous or categorical lipoprotein(a) to the Cox model led to a significant improvement in C-statistic, net reclassification, and integrated discrimination. Conclusions With a large sample size and long-term follow-up, our data confirmed that high lipoprotein(a) levels could be associated with a poor prognosis after PCI in stable coronary artery disease patients, suggesting that lipoprotein(a) measurements may be useful for patient risk stratification before selective PCI.
Targeted therapy has been standardized in front-line therapies for metastatic colorectal cancer (mCRC), while explicit recommendations for third- or later-line are still lacking. This study evaluated ...the efficacy and safety of combining targeted therapy with chemotherapy in the third- or later-line treatment for mCRC
meta-analysis, providing evidence-based guidance for clinical or research practice. Comprehensive retrieval of related studies was conducted according to the PRISMA guideline. Studies were stratified with patient characteristics and pharmacological classification of the drugs. For the data available for quantitative analysis, pooled overall response rate, disease control rate, hazard ratios (HRs) for overall survival (OS) and progression-free survival (PFS), and adverse events rate with respective 95% confidence intervals (CIs) were calculated. A total of 22 studies (1,866 patients) were included in this meta-analysis. Data from 17 studies (1,769 patients) involving targets of epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF) were extracted for meta-analyses. The overall response rates for monotherapy and combined therapy were 4% (95% CI: 3%, 5%) and 20% (95% CI: 11%, 29%). The pooled HRs (combined therapy
mono) for OS and PFS were 0.72 (95% CI: 0.53, 0.99) and 0.34 (95% CI: 0.26, 0.45). Another five studies were included in narrative depiction, involving targets of BRAF, HER-2, ROS1, and NTRK. The findings of this meta-analysis indicate that VEGF and EGFR inhibitors manifest promising clinical response rates and prolonged survival in the treatment of mCRC with acceptable adverse events.
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