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1.
J Hazard Mater ; 416: 126166, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34492942

RESUMO

Heavy metal pollution is one of the primary challenges of water pollution, and the fabrication of highly effective, green and non-toxic adsorbents for heavy metals is urgently required on the basis of environmental and sustainable development strategies. Here, we report a novel fluorescent wood (FW) with effective adsorption ability (maximum theoretical adsorption capacity of 98.14 mg/g for hexavalent chromium [Cr(VI)]), good fluorescence properties (absolute quantum yield of 12.8%), non-cytotoxicity (cell viability of >90%) and high detection sensitivity and selectivity for Cr(VI). The FW was formed using a process involving delignification, infiltration with carbon dots, and free-radical polymerization with acrylic acid. Mechanistic analysis confirmed that the reconstructed 3D porous structure of the FW provided many effective sorption sites, such as amino, hydroxyl and carboxyl groups. This improved the adsorption ability and stabilized the fluorescence signal, which enhanced the detection ability. These factors give the novel FW considerable potential for use in the removal of Cr(VI) ions from wastewater.

2.
J Food Biochem ; : e13928, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34524691

RESUMO

The effects of rutin (6, 30, and 150 µmol/gpro ) on the physicochemical, structural properties and gel characteristics of myofibrillar protein (MP) under oxidative stress were investigated. The addition of rutin significantly promoted the formation of oxidized MP carbonyl derivatives and dimer tyrosine, but it cannot prevent the loss of sulfhydryl groups (-SH). With increasing rutin concentration, the hydrophobic area was gradually shielded and rutin acted as a quencher to reduce the fluorescence intensity of oxidized MP. Under the oxidative stress, rutin increased the particle size and aggravated the cleavage of protein molecules. SDS-polyacrylamide gel electrophoresis revealed that rutin further aggravated oxidized MP degradation and cross-linked form polymer which cross-linked with protein to the maximum extent at 150 µmol/gpro rutin content. Moderate cross-linking between protein and rutin could improve the gel strength and water holding capacity (WHC) of oxidized MP gel. For rutin concentrations of 6 and 30 µmol/gpro , the gels had denser network structures, as observed by scanning electron microscopy. PRACTICAL APPLICATIONS: Polyphenols of the type and dosage can change the properties of the product itself and optimize the quality of product processing. Certain polyphenols may promote the oxidation process of protein-rich products, but this does not affect the improvement of product quality. The application of natural polyphenols is the promising business direction in the development of Coregonus peled industry.

3.
Zhongguo Zhong Yao Za Zhi ; 46(15): 3943-3948, 2021 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-34472271

RESUMO

The study aims to investigate the effect of the compatibility of paeonol and paeoniflorin(hereinafter referred to as the compatibility) on the expression of myocardial proteins in rats with myocardial ischemia injury and explore the underlying mechanism of the compatibility against myocardial ischemia injury. First, the acute myocardial infarction rat model was established by ligation of the anterior descending branch of the left coronary artery. The model rats were given(ig) paeonol and paeoniflorin. Then protein samples were collected from rat cardiac tissue and quantified by tandem mass tags(TMT) to explore the differential proteins after drug intervention. The experimental results showed that differential proteins mainly involved phagocytosis engulfment, extracellular space, and antigen binding, as well as Kyoto encyclopedia of genes and genomes(KEGG) pathways of complement and coagulation cascades, syste-mic lupus erythematosus, and ribosome. In this study, the target proteins and related signaling pathways identified by differential proteomics may be the biological basis of the compatibility against myocardial ischemia injury in rats.


Assuntos
Isquemia Miocárdica , Traumatismo por Reperfusão Miocárdica , Acetofenonas , Animais , Glucosídeos , Monoterpenos , Isquemia Miocárdica/tratamento farmacológico , Isquemia Miocárdica/genética , Proteômica , Ratos , Ratos Sprague-Dawley
4.
Nanoscale ; 13(33): 14179-14185, 2021 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-34477699

RESUMO

Nanoarray catalysts supported on substrates provide an opportunity for industrially promising overall water splitting at large current densities. However, most of the present electrocatalysts show high overpotentials at a large current density, inducing a low efficiency for industrial water electrolysis. Herein, using the classic NiCoP nanorod arrays as the basic catalyst model, we presented a trace W and Mo co-doped strategy to boost the overall water splitting electrocatalysis at an industrial current density. After a trace amount of W and Mo atoms was doped, the constructed W and Mo co-doped NiCoP nanorod arrays (W,Mo-NiCoP/NF) show a low overpotential of 249 mV towards the hydrogen evolution reaction (HER) at a very large current density of 1000 mA cm-2. We deduce that the regulation of the electronic structure caused by the trace W and Mo atoms, as well as the intrinsic features of nanoarrays leads to enhanced catalytic activity. In addition, a significant enhancement towards the oxygen evolution reaction (OER) was also achieved by this co-doped strategy. Finally, an overall water splitting device using W,Mo-NiCoP/NF as both the anode and cathode was assembled to exhibit a low cell voltage of 1.85 V at a large current density of 500 mA cm-2 and an excellent long-term stability within 50 h, better than most of the state-of-the-art bifunctional electrocatalysts yet reported. Our results highlight the significance of trace-doping engineering in industrial water electrolysis.

5.
Chem Commun (Camb) ; 2021 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-34486610

RESUMO

Taking advantage of the accumulation of a number of noncovalent intramolecular interactions, octanuclear and hexanuclear trefoil knots are self-assembled based on half-sandwich rhodium fragments. The selective synthesis of either the octanuclear or hexanuclear knot can be controlled by altering different dipyridyl arms.

6.
Sci Total Environ ; 803: 149874, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34492491

RESUMO

The treatment of sewage sludge (SS) is an environmental problem worldwide. In recent years, hydrothermal carbonization (HTC) of SS for hydrochar (HC) has attracted extensive attention. This study preliminarily explored the microwave-assisted HTC of SS for the first time. Increasing the reaction temperature (150-250 °C) and reaction time (0-120 min) resulted in a decrease in the HC yield, and it gradually increased with the rising solid-liquid ratio (0.03-0.25 g/mL). Compared with raw SS, the HC products possessed higher aromaticity, carbonization degree, porosity, and polarity, and lower content of soluble nutrients (N/P/K) and leachable heavy metals (Cu, Zn, Pb, Cd, Cr, and Ni), indicating a lower risk of nutrient and heavy metal loss. Attention should be paid to the total contents of Zn and Cd in HC exceeded the permitted value for use in cultivated land with edible crops. The use of CaO as a catalyst improved the yield of HC, made the HC and process water (PW) weakly alkaline, and further passivated the heavy metals in the HC. In the case of H3PO4, although the conversion of SS was enhanced (lower content of volatile organic matter in HC), the contents of soluble nutrients (N/P/K) in HC/PW increased, and the migration of Zn and Cd into process water was enhanced. The HCs obtained in this study had poor combustion properties, but higher ignition temperatures than raw SS. PW must be properly treated or recycled because it still contained high contents of organic matter and nutrients. This fundamental study provides basic insights into the microwave-assisted HTC of SS.

7.
Zhongguo Zhong Yao Za Zhi ; 46(12): 3066-3075, 2021 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-34467697

RESUMO

Lycii Cortex, the dry root bark of Lycium barbarum(Solanaceae), is rich in chemical compositions with unique structures, such as organic acids, lipids, alkaloids, cyclopeptides and other components, and plays an important role in traditional Chinese medicine. It has the effect of cooling blood and removing steam, clearing lung and reducing fire. It is mainly used in the treatment of hot flashes due to Yin deficiency, hectic fever with night sweat, cough, hemoptysis and internal heat and diabetes. Modern pharmacological studies have shown that the crude extract or monomer of Lycii Cortex has a variety of pharmacological activities, such as hypoglycemic, hypotensive, hypolipidemic, antibacterial, and antiviral effects. In this paper, the chemical constituents and pharmacological effects of Cortex Lycii were reviewed in order to further clarify its effective substances, promote the development of medical undertakings, and ensure the "Healthy China" plan.


Assuntos
Lycium , China , Hipoglicemiantes , Medicina Tradicional Chinesa , Casca de Planta
8.
Histol Histopathol ; : 18371, 2021 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-34477212

RESUMO

Perilipin-2, a lipid droplet (LD) coating protein, has been found to be involved in cancer progression. However, its role in hepatoblastoma (HB) is undefined. We collected 87 HB samples and the corresponding clinical data. Immunohistochemistry (IHC) staining was performed to detect perilipin-2 and the association of the perilipin-2 expression with clinical characteristics and prognosis was analyzed. The expression of perilipin-2 was increased in fetal HB components in comparison to embryonal HB components. The predominant staining pattern was vesicular in fetal HB cells, while it was granular in embryonal HB cells. Furthermore, strong expression of perilipin-2 was associated with the histopathological type of fetal predominant HB. Although event-free survival (EFS) did not differ to a statistically significant extent between the strong and weak expression groups in a univariate survival analysis, a multivariate survival analysis revealed that EFS was significantly improved in the strong perilipin-2 expression group. In conclusion, perilipin-2 is differentially expressed in HB and the strong expression of perilipin-2 predicts a better prognosis.

9.
Pharmacol Res ; 172: 105849, 2021 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-34450307

RESUMO

Nonalcoholic steatohepatitis (NASH) is a common chronic liver disease in clinical practice. It has been considered that NASH is one of the main causes of chronic liver disease, cirrhosis and carcinoma. The mechanism of the NASH progression is complex, including lipid metabolism dysfunction, insulin resistance, oxidative stress, inflammation, apoptosis, fibrosis and gut microbiota dysbiosis. Except for lifestyle modification and bariatric surgery, there has been no pharmacological therapy that is being officially approved in NASH treatment. Traditional Chinese medicine (TCM), as a conventional and effective therapeutic strategy, has been proved to be beneficial in treating NASH in numbers of studies. In the light of this, TCM may provide a potential therapy for treating NASH. In this review, we summarized the associated mechanisms of action TCM treating NASH in preclinical studies and systematically analysis the effectiveness of TCM treating NASH in current clinical trials.

10.
Environ Pollut ; 287: 117626, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34426372

RESUMO

In this study, Gymnodinium aeruginosum was exposed to polystyrene (PS) and polymethyl methacrylate (PMMA) of three particle sizes (0.1 µm, 1.0 µm and 100 µm) and two concentrations (10 mg/L and 75 mg/L) for 96 h. The density of algae cells, the endpoints that reactive oxygen species (ROS), total protein (TP), malondialdehyde (MDA), superoxide dismutase (SOD) and catalase (CAT), scanning and transmission electron microscopy (SEM and TEM) were used to explore the toxicity mechanism to the microalgae. At a concentration of 75 mg/L, the 96 h inhibition ratios (IR) with particle sizes of 0.1 µm, 1.0 µm and 100 µm on G. aeruginosum were 55.9%, 63.7% and 6.0% for PS, respectively, and 3.0%, 4.1% and -0.6% for PMMA, respectively. The most significant changes in ROS, TP, MDA, SOD and CAT were observed at 75 mg/L 1.0 µm of PS when treated for 96 h. When exposed to nanoplastics (NPs) and microplastics (MPs), the algae cells were damaged, and the antioxidant system was activated. Extracellular polymeric substance (EPS) could help to detoxify the algae. In general, PS was more toxic than PMMA. The toxicity of small MNPs (0.1 µm and 1.0 µm) was related to the concentrations, while large MNPs (100 µm) did not.


Assuntos
Dinoflagelados , Poluentes Químicos da Água , Matriz Extracelular de Substâncias Poliméricas , Plásticos , Polimetil Metacrilato , Poliestirenos
11.
Clin Neurol Neurosurg ; 208: 106844, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34388595

RESUMO

Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by the loss of dopamine-producing neurons in the substantia nigra and the abnormal cytoplasmic accumulation of proteinaceous aggregates called Lewy bodies (LBs), mainly composed of α-synuclein (α-syn). In recent years, it has been gradually recognized that fatigue is one of the most common and disabling symptoms in PD patients, with a prevalence of approximately 50%. Although neuroinflammation, a pathological hallmark of PD, is closely associated with fatigue, present mechanisms of fatigue in PD patients have not yet been systematically summarized, with their inflammatory predictors remaining controversial. Therefore, the aim of this brief review is to fill in the gaps in our understanding on the inflammatory factors involved in the pathophysiological mechanisms of fatigue and predicting its occurrence in PD patients. The determination of fatigue is mainly assessed using the Parkinson Fatigue Scale 16 (PFS-16) and Fatigue Severity Scale 9 (FSS-9). Several studies have reported that inflammatory marker levels, such as interleukin-6 (IL-6), and other inflammatory predictors closely associated with fatigue, such as soluble IL-2 receptor (sIL-2R), tumor necrosis factor alpha (TNF-α), high-sensitivity C-reactive protein (hs-CRP), neutrophil-to-lymphocyte ratio (NLR), and red blood cell distribution width (RDW), may help detect fatigue. Moreover, the following inflammatory mechanisms may be involved. (1) Abnormal aggregation of α-syn undergoes a conformational change, which then activates toll-like receptor 4 (TLR4) to release a large number of proinflammatory cytokines, causing fatigue symptoms. (2) Chronic peripheral inflammation and immune activation responses induce elevated levels of proinflammatory cytokines in PD patients, which enter the brain mainly through the traditional endocrine route or via direct vagus nerve transmission. The rising levels of proinflammatory cytokines cause the destruction of the blood-brain barrier (BBB) by combining with BBB endothelial cells, allowing many proinflammatory cytokines to cross the destroyed BBB and enter the brain, preventing astrocytes from reuptaking glutamate and laying foundations for the occurrence of fatigue. Furthermore, studies have suggested that fatigue symptoms in PD patients often represent a poor prognosis. Nevertheless, if the aforementioned inflammatory markers can effectively predict the occurrence of fatigue and allow early intervention, the prognosis of PD patients could be significantly improved. At present, its management mainly includes medical treatment (levodopa, dopamine receptor agonists, rasagiline, and antidepressants) and non-medical treatment (acupuncture and yoga). Thus, it is of great significance to be able to practice early detection and intervention in fatigue and improve the prognosis of patients with PD.

12.
Eur J Pharmacol ; 909: 174439, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34425100

RESUMO

Phillyrin, a natural plant extract, has significant antioxidant and anti-apoptotic effects. However, its effect on intracerebral hemorrhage (ICH) remains unclear. In this study, we investigated a potential role for phillyrin in the regulation of the oxidative stress and apoptosis induced by ICH. A model of ICH was induced by collagenase IV (0.2 U in 1 µl sterile normal saline) in male C57BL/6J (B6) mice and different doses of phillyrin (5, 15, or 30 mg/kg) were intraperitoneally (i.p.) injected at 30 min, 6 h, and 22 h after modeling. We found that phillyrin significantly reduced neural function and lesion volume, improved injury of white and grey matter around the lesion, decreased apoptosis and oxidative stress, increased the expression of nuclear factor-erythroid 2-related factor 2 (Nrf2), heme oxygenase 1(HO-1), NADPH quinone oxidoreductase 1 (NQO1) and Superoxide Dismutase-1(SOD-1) in vitro and in vivo, and protected neurons from the stimulation of hemin by promoting Nrf2 nuclear translocation. Treatment with ML385 (Nrf2 inhibitor) completely reversed the protective effects of phillyrin in vivo after ICH injury. Based on our findings, we conclude that phillyrin treatment alleviates ICH injury-induced apoptosis and oxidative stress via activation of the Nrf2 signaling pathway, highlighting a potential role for phillyrin as an ICH therapeutic.

13.
Cell Immunol ; 368: 104421, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34385001

RESUMO

Epigallocatechin-3 gallate (EGCG) is a polyphenolic component of tea and has potential curative effects in patients with autoimmune diseases. Multiple sclerosis (MS) is an autoimmune disease affecting the central nervous system (CNS). It remains unknown whether EGCG can regulate macrophage subtypes in MS. Here we evaluated the effects of EGCG in experimental autoimmune encephalomyelitis (EAE), MS mouse model. We found that EGCG treatment reduced EAE severity and macrophage inflammation in the CNS. Moreover, EAE severity was well correlated with the ratio of M1 to M2 macrophages, and EGCG treatment suppressed M1 macrophage-mediated inflammation in spleen. In vitro experiments showed that EGCG inhibited M1 macrophage polarization, but promoted M2 macrophage polarization. These effects were likely to be related to the inhibition of nuclear factor-κB signaling and glycolysis in macrophages by EGCG in macrophages. Overall, these findings provided important insights into the mechanisms through which EGCG may mediate MS.

14.
Artigo em Inglês | MEDLINE | ID: mdl-34417971

RESUMO

Diesel oxidation catalysts Pt-Pd-(y)ZrO2-(z)WO3/CeZrOx-Al2O3 with total Pt & Pd loading of only 0.68 wt.% were prepared and investigated for oxidation activity and stability of CO, C3H6, and NO. Introduction of ZrO2 greatly improved low-temperature activities and retained stability especially for CO and C3H6 oxidation after treated at 800 °C. With the optimal loading amount of 6 wt% ZrO2, 2 wt% WO3 was introduced to the system and showed higher activity. Reaction temperature for 50% CO and C3H6 conversion declined to 160 and 181 °C, and the maximal NO conversion increased to 50%. By using XRD, TEM, CO chemisorption, XPS, and H2-TPR analysis, it was found that ZrO2 could inhibit aggregation of Pt and Pd, improve metal dispersion, and increase surface-chemisorbed oxygen after high-temperature treatment, accounting for promoted performance. Also, there were more reducible oxide species in ZrO2-doped catalysts. ZrO2 could induce reduction of noble metal oxides and surface ceria by weakening Pt-O-Ce interaction, which increased the ability to dissociate H2 and spillover effect of dissociated hydrogen to ceria. Doping WO3 increased metal dispersion of fresh samples and brought more Pt0 species that were active sites for oxidation reactions. Thus, ZrO2 and WO3 could be effective additives for oxidation catalysts to synergistically improve their activities and thermal stability.

15.
J Alzheimers Dis ; 2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34420973

RESUMO

BACKGROUND: Previous studies revealed that abnormal blood pressure (BP) plays an important role in the pathogenesis of Alzheimer's disease (AD). However, little is known about the ambulatory BP characteristics of AD in the mild or severe stage. OBJECTIVE: We explored the ambulatory BP characteristics of AD in the mild or severe stage. METHODS: In the present study, 106 AD patients (42.5%male, average age 81.6 years) were enrolled from three centers in China. Clinal BP measurements at the supine and standing positions, neurological evaluations, and the 24 h ambulatory BP monitoring were performed. Statistical methods included the two-sample t-test, chi-square test, Spearman correlation analysis, and multivariate linear regression. RESULTS: In the 106 AD patients, 49.2%, 36.8%, and 70%of patients had 24 h, daytime, and nighttime systolic hypertension, respectively, while 19.8%, 29.2%, and 5.7%had 24 h, daytime, and nighttime diastolic hypotension. The prevalence of the reduced and reverse dipping pattern was 34.0%and 48.1%for systolic BP and 32.1%and 45.3%for diastolic BP, respectively. The daytime diastolic BP was significantly correlated with cognitive performance. After adjustment for age, sex, and body mass index, only daytime diastolic BP was associated with remarkable cognitive deterioration (p≤0.008). Further, AD patients in the severe stage had significantly lower levels of the 24 h, daytime, and nighttime diastolic BP, compared with those in the mild stage. CONCLUSION: In general, AD patients were featured with high nighttime systolic BP, low daytime diastolic BP, and abnormal circadian BP rhythm of reduced and reverse dipping. The diastolic BP, especially daytime diastolic BP, was adversely correlated with the cognitive deterioration in AD.

16.
Int J Nanomedicine ; 16: 5053-5064, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34349508

RESUMO

Background: High levels of oxidants, such as reactive oxygen species (ROS) and reactive nitrogen species (RNS), are typical characteristics of an inflammatory microenvironment and are closely associated with a various inflammatory pathologies, eg, cancer, diabetes, atherosclerosis, and neurodegenerative diseases. Therefore, the delivery of anti-inflammatory drugs by oxidation-responsive smart systems would be an efficient anti-inflammatory strategy that benefits from the selective drug release in an inflammatory site, a lower treatment dose, and minimizes side effects. Purpose: In this study, we present the feasibility of an oxidation-sensitive PEGylated alternating polyester, methoxyl poly(ethylene glycol)-block-poly(phthalic anhydride-alter-glycidyl propargyl ether) (mPEG-b-P(PA-alt-GPBAe)), as novel nanocarrier for curcumin (CUR), and explore the application in anti-inflammatory therapy. Methods: The copolymers used were obtained by combining a click reaction and a ring-opening-polymerization method. CUR was loaded by self-assembly. The in vitro drug release, cytotoxicity toward RAW 264.7 cells and cellular uptake were investigated. Furthermore, the anti-inflammatory effects of CUR-loaded polymeric nanoparticles (NPs-CUR) were investigated in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages and tested in a murine model of ankle inflammation. Results: Fast drug release from NPs-CUR was observed in trigger of 1 mM H2O2 in PBS. Compared with NPs and free drugs, the significant anti-inflammatory potential of NPs-CUR was proven in activated RAW 264.7 cells by inhibiting the production of TNF-α, IL-1ß, and IL-6 and increasing the level of an anti-inflammatory cytokine IL-10. Finally, a local injection of NPs-CUR at a dose of 0.25 mg/kg suppressed the acute ankle inflammatory response in mice by histological observation and further reduced the expression of pro-inflammatory cytokines in the affected ankle joints compared to that of free CUR. Conclusion: Both the significant in vitro and in vivo anti-inflammatory results indicated that our oxidation responsive polymeric nanoparticles are promising drug delivery systems for anti-inflammatory therapy.

17.
Artigo em Inglês | MEDLINE | ID: mdl-34366198

RESUMO

BACKGROUND: Apoptosis, also called programmed cell death, is a genetically controlled process against hyperproliferation and malignancy. The Fas-Fas ligand (FasL) system is considered a major pathway for apoptosis in cells and tissues. Thus, this study aimed to investigate whether single nucleotide polymorphisms (SNPs) in Fas and FasL gene may have effects on the recurrence and survival of patients with hepatocellular carcinoma (HCC) after curative hepatectomy. METHODS: We investigated the relationship between Fas rs1800682, rs2234767 and FasL rs763110 polymorphisms and recurrence-free survival (RFS) as well as overall survival (OS) in 117 Chinese Han patients with HCC who underwent hepatectomy. RESULTS: In Kaplan-Meier survival analysis, only Fas rs1800682 (-670 A/G) was associated with RFS and OS. Compared with AA genotype, the AG/GG genotype was significantly associated with better RFS (P = 0.008) and OS (P = 0.020). Moreover, multivariate Cox regression analysis showed that Fas rs1800682 remained as a significant independent predictor of RFS for HCC patients with hepatectomy [AG/GG vs. AA: adjusted hazard ratio = 0.464, 95% confidence interval: 0.275-0.782, P = 0.004], but was not an independent predictor of OS (P = 0.395). CONCLUSIONS: This study demonstrated that Fas -670 G allele may play a protective role in the recurrence and survival of HCC patients with hepatectomy. Furthermore, Fas rs1800682 polymorphism might be a promising biomarker for HCC patients after hepatectomy.

18.
J Am Chem Soc ; 143(31): 12404-12411, 2021 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-34337934

RESUMO

One fascinating and challenging synthetic target in the field of mechanically interlocked molecules is the family of linear [4]catenanes, which are topologically identical to the logo of automobile maker Audi. Herein, we report an "all-in-one" synthetic strategy for the synthesis of linear metalla[n]catenanes (n = 2-4) by the coordination-driven self-assembly of Cp*Rh-based (Cp* = η5-pentamethylcyclopentadienyl) organometallic rectangle π-donors and tetracationic organic cyclophane π-acceptors. We selected the pyrenyl group as the π-donor unit, leading to homogeneous metalla[2]catenanes and cyclic metalla[3]catenanes via π-stacking interactions. By taking advantage of the strong electrostatic interactions between π-donor units and π-acceptor units, a heterogeneous metalla[2]catenanes and linear metalla[3]catenanes, respectively, could be obtained by the simple stirring of homogeneous metalla[2]catenanes with a suitable tetracationic cyclophane. On this basis, this "all-in-one" synthetic strategy was further used to realize a quantitative one-step synthesis of a linear metalla[4]catenanes via the self-assembly of cyclic metalla[3]catenanes and tetracationic cyclophanes. All heterogeneous metalla[n]catenanes (n = 2-4) were fully characterized by single-crystal X-ray analysis, NMR spectroscopy and electrospray ionization mass spectrometry.

19.
Appl Environ Microbiol ; : AEM0138321, 2021 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-34378947

RESUMO

Arsenic (As) metabolism genes are generally present in soils but their diversity, relative abundance, and transcriptional activity in response to different As concentrations remain unclear, limiting our understanding of the microbial activities that control the fate of an important environmental pollutant. To address this issue, we applied metagenomics and metatranscriptomics to paddy soils showing a gradient of As concentrations to investigate As resistance genes (ars) including arsR, acr3, arsB, arsC, arsM, arsI, arsP, and arsH as well as energy-generating As respiratory oxidation (aioA) and reduction (arrA) genes. Somewhat unexpectedly, the relative DNA abundances and diversity of ars, aioA, and arrA genes were not significantly different between low and high (∼10 vs ∼100 mg kg-1) As soils. By comparison to available metagenomes from other soils, geographic distance rather than As levels drove the different compositions of microbial communities. Arsenic significantly increased ars genes abundance only when its concentration was higher than 410 mg kg-1. In contrast, between low and high As soils, metatranscriptomics revealed a significant increase in transcription of ars and aioA genes, which are induced by arsenite, the dominant As species in paddy soils, but not arrA genes, which are induced by arsenate. These patterns appeared to be community-wide as opposed to taxon-specific. Collectively, our findings advance understanding of how microbes respond to high As levels and the diversity of As metabolism genes in paddy soils and indicated that future studies of As metabolism in soil, or other environments, should include the function (transcriptome) level. IMPORTANCE Arsenic (As) is a toxic metalloid pervasively present in the environment. Microorganisms have evolved the capacity to metabolize As, and As metabolism genes are ubiquitously present in the environment even in the absence of high concentrations of As. However, these previous studies were carried out at the DNA level and thus, the activity of the As metabolism genes detected remains essentially speculative. Here, we show that the high As levels in paddy soils increased the transcriptional activity rather than the relative DNA abundance and diversity of As metabolism genes. These findings advance our understanding of how microbes respond to and cope with high As levels and have implications for better monitoring and managing an important toxic metalloid in agricultural soils and possibly other ecosystems.

20.
Neural Plast ; 2021: 7088856, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34335734

RESUMO

Suicidal ideation (SI) is a direct risk factor for suicide in patients with depression. Regarding the emergence of SI, previous studies have discovered many risk factors, including childhood abuse as the major public problem. Previous imaging studies have demonstrated that SI or childhood abuse has effects on brain structure and function, respectively, but the interaction effects between them have not been fully studied. To explore the interaction effect between SI and childhood abuse, 215 patients with major depressive disorder completed the Childhood Trauma Questionnaire to evaluate childhood abuse and Beck's Scale for Suicidal Ideation to evaluate SI. Then, they completed magnetic resonance imaging (MRI) within one week after completing questionnaires. Respectively, we preprocessed the structural and functional images and analyzed gray matter volumes (GMV) and mean fractional amplitude of low-frequency fluctuation (mfALFF) values. Results showed that the changes of GMV in the cuneus, precuneus, paracentric lobule, inferior frontal gyrus, and caudate nucleus and local activity in cuneal and middle temporal gyrus are in relation with SI and childhood abuse. And in left caudate, SI and childhood abuse interact with each other on the influence of GMV. That is, the influence of SI in GMV was related to childhood abuse, and the influence of childhood abuse in GMV was also related to SI. Therefore, the combination of SI and childhood abuse based on imaging should help us better understand the suicide ideation developing mechanism and propose more effective targeted prevention strategies for suicide prevention.

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