Genetic characterization and molecular epidemiological analysis of enterovirus C99 in China.

Enterovirus C99 (EV-C99) is a newly identified EV serotype within the species Enterovirus C. Few studies on EV-C99 have been conducted globally. More information and research on EV-C99 are needed to assess its genetic characteristics, phylogenetic relationships, and associations with enteroviral diseases. Here, the phylogenetic characteristics of 11 Chinese EV-C99 strains have been reported. The full-length genomic sequences of these 11 strains show 79.4-80.5% nucleotide identity and 91.7-94.3% amino acid (aa) identity with the prototype EV-C99. A maximum likelihood phylogenetic tree constructed based on the entire VP1 coding region identified 13 genotypes (A-M), revealing a high degree of variation among the EV-C99 strains. Phylogeographic analysis showed that the Xinjiang Uygur Autonomous Region is an important source of EV-C99 epidemics in various regions of China. Recombination analysis revealed inter-serotype recombination events of 16 Chinese EV-C99 strains in 5' untranslated regions and 3D regions, resulting in the formation of a single recombination form. Additionally, the Chinese strain of genotype J showed rich aa diversity in the P1 region, indicating that the genotype J of EV-C99 is still going through variable dynamic changes. This study contributes to the global understanding of the EV-C99 genome sequence and holds substantial implications for the surveillance of EV-C99.

Identification and genetic characterization of a recently identified enterovirus C116 in China.

Enterovirus C116 (EV-C116) is a new member of the enterovirus C group which is closely associated with several infectious diseases. Although sporadic studies have detected EV-C116 in clinical samples worldwide, there is currently limited information available. In this study, two EV-C-positive fecal specimens were detected in apparently healthy children, which harbored low abundance, through meta-transcriptome sequencing. Based on the prototypes of several EV-Cs, two lineages were observed. Lineage 1 included many types that could not cause EV-like cytopathic effect in cell culture. Three genogroups of EV-C116 were divided in the maximum likelihood tree, and the two strains in this study (XZ2 and XZ113) formed two different lineages, suggesting that EV-C116 still diffuses worldwide. Obvious inter-type recombination events were observed in the XZ2 strain, with CVA22 identified as a minor donor. However, another strain (XZ113) underwent different recombination situations, highlighting the importance of recombination in the formation of EV-Cs biodiversity. The EV-C116 strains could propagate in rhabdomyosarcoma cell cultures at low titer; however, EV-like cytopathic effects were not observed. HEp-2, L20B, VERO, and 293T cell lines did not provide an appropriate environment for EV-C116 growth. These results challenge the traditional recognition of the uncultured nature of EV-C116 strains and explain the difficulty of clinical detection.

Hydrogel Rivet with Unidirectional Shape Morphing for Flexible Mechanical Assembly.

Integrating diverse materials and functions into highly additive produce has piqued global interest due to the increasing demands of intelligent soft robotics. Nevertheless, existing assembly techniques, especially supramolecular assembly which heavily rely on precise chemical design and specific recognition, may prove inadequate when confronted with diverse external demands. Inspired by the traditional mechanical assembly, rivet connection, herein, a thermo-responsive hydrogel with unidirectional shape-morphing is fabricated and a stable mechanical assembly is constructed by emulating the rivet connection mechanism. This system employed poly(acrylamide-co-acrylic acid) [P(AAm-co-AAc)] to induce continuous swelling and hexylamine-modified polyvinyl alcohol (PVA-C6) as a molecular switch to control the swelling process. The hydrogel rivet, initially threaded through pre-fabricated hollows in two components. Subsequently, upon the disassociation of alkane chains the molecular switch would activate, inducing swelling and stable mechanical assembly via anchor structures. Moreover, to enhance the assembly strength, knots are introduced to enhance assembly strength, guiding localized stress release for programmed deformations. Additionally, the system can be remotely controlled using near-infrared light (NIR) by incorporating photo-thermal nanoparticles. This work presents a universal and efficient strategy for constructing stable mechanical assemblies without compromising overall softness, offering significant potential for the fabrication of integrated soft robots.

Effect of exposures to multiple metals on blood pressure and hypertension in the elderly: a community-based study.

A chronic disease, hypertension (HTN) is prevalent among the elderly. Exploring the factors that influence HTN and blood pressure (BP) changes is of great public health significance. However, mixed exposure to multiple serum metals has had less research on the effects on BP and HTN for the elderly. From April to August 2019, 2372 people participated in the community physical examination program for the elderly in Tongling City, Anhui Province. We measured BP and serum levels of 10 metals and collected basic demographic information. We analyzed the relationship between metal levels and changes in BP and HTN by the least absolute shrinkage and selection operator regression, Bayesian kernel machine regression model, and generalized linear model. In multiple models, lead (Pb) and cadmium (Cd) were still significantly associated with HTN occurrence after adjusting for potential confounders (Pb: ORquartile 4 VS quartile 1 = 1.20, 95% CI 1.01-1.43; Cd: ORquartile 4 VS quartile 1 = 1.37, 95% CI 1.16-1.62). In the male subgroup, results were similar to those of the general population. In the female group, Cd was positively correlated with HTN and systolic blood pressure, while Pb was not. According to this study, Pb and Cd were correlated with BP and HTN positively, and there was a certain joint effect. To some extent, our findings provide clues for the prevention of hypertension in the elderly.

[Development of green pesticides from traditional Chinese medicines based on artificial intelligence and compatibility of traditional Chinese medicines].

The food security of China as a big agricultural country is attracting increasing attention. With the progress in the traditional Chinese medicine industry, Chinese medicinal materials and their preparations have been gradually developed as agents for disease prevention and with antimicrobial and insecticidal functions in agriculture. Promoting pesticide innovation by interdisciplinary integration has become the trend in pesticide research globally. Considering the increasingly important roles of green pesticides from traditional Chinese medicines and artificial intelligence in pest target prediction, this paper proposed an innovative green control strategy in line with the concepts of ecological sustainable development and food security protection. CiteSpace was used for visual analysis of the publications. The results showed that artificial intelligence had been extensively applied in the pesticide field in recent years. This paper explores the application and development of biopesticides for the first time, with focus on the plant-derived pesticides. The thought of traditional Chinese medicine compatibility can be employed to creat a new promosing field: pesticides from traditional Chinese medicine. Moreover, artificial intelligence can be employed to build the formulation system of pesticides from traditional Chinese medicines and the target prediction system of diseases and pests. This study provides new ideas for the future development and market application of biopesticides, aiming to provide more healthy and safe agricultural products for human beings, promote the innovation and development of green pesticides in China, and protect the sustainable development of the environment and ecosystem. This may be the research hotspot and competition point for the green development of the pesticide industry chain in the future.

Pathological Characteristics of Echovirus 30 Infection in a Mouse Model.

Echovirus 30 (E30), a member of species B enterovirus, is associated with outbreaks of aseptic meningitis and has become a global health emergency. However, the pathogenesis of E30 remains poorly understood due to the lack of appropriate animal models. In this study, we established a mouse infection model to explore the pathogenicity of E30. The 2-day-old IFNAR-/- mice infected with E30 strain WZ16 showed lethargy and paralysis, and some died. Obvious pathological changes were observed in the skeletal muscle, brain tissue, and other tissues, with the highest viral load in the skeletal muscles. Transcriptome analysis of brain and skeletal muscle tissues from infected mice showed that significant differentially expressed genes were enriched in complement response and neuropathy-related pathways. Using immunofluorescence assay, we found that the viral double-stranded RNA (dsRNA) was detected in the mouse brain region and could infect human glioma (U251) cells. These results indicated that E30 affects the nervous system, and they provide a theoretical basis for understanding its pathogenesis. IMPORTANCE Echovirus 30 (E30) infection causes a wide spectrum of diseases with mild symptoms, such as hand, foot, and mouth disease (HFMD), acute flaccid paralysis, and aseptic meningitis and other diseases, especially one of the most common pathogens causing aseptic meningitis outbreaks. We established a novel mouse model of E30 infection by inoculating neonatal mice with clinical isolates of E30 and observed the pathological changes induced by E30. Using the E30 infection model, we found complement responses and neuropathy-related genes in the mice tissues at the transcriptome level. Moreover, we found that the viral dsRNA localized in the mouse brain and could replicate in human glioma cell line U251 rather than in the neuroblastoma cell line, SK-N-SH.

Characterizing enterovirus C96 genome and phylodynamics analysis.

Enterovirus C96 (EV-C96) is a recently discovered serotype belonging to enterovirus C species. It had been isolated from patients with acute flaccid paralysis, hand, foot, and mouth disease, diarrhea, healthy people, or environmental specimens. Despite increasing reports of the virus, the small number of full-length genomes available for EV-C96 has limited molecular epidemiological studies. In this study, newly collected rare EV-C96 strains in China from 1997 to 2020 were combined with sequences available in GenBank for comprehensive analyses. Sequence analysis revealed that the nucleotide sequence similarity of EV-C96 and the prototype strain (BAN00-10488) was 75%-81.8% and the amino acid sequence similarity was 85%-94.9%. EV-C96 had a high degree of genetic variation and could be divided into 15 genogroups. The mean evolutionary rate was 5.16 × 10-3 substitution/site/year, and the most recent common ancestor was dated to 1925. A recombination analysis revealed that EV-C96 may be a recombinant derived from other serotypes in the EV-C group in the nonstructural protein coding region. This comprehensive and integrated analysis of the whole genome sequence of EV-C96 provides valuable data for further studies on the molecular epidemiology of EV-C96 worldwide.

The impact of ambient air pollutants on childhood respiratory system disease and the resulting disease burden: a time-series study.

PURPOSE: The effects of air pollution on human health have long been a hot topic of research. For respiratory diseases, a large number of studies have proved that air pollution is one of the main causes. The purpose of this study was to investigate the risk of hospitalization of children with respiratory system diseases (CRSD) caused by six pollutants (PM2.5, PM10, NO2, SO2, CO, and O3) in Hefei City, and further calculate the disease burden. METHOD: In the first stage, the generalized additive models were combined with the distributed lag non-linear models to evaluate the impact of air pollution on the inpatients for CRSD in Hefei. In the second stage, this study used the cost-of-illness approach to calculate the attributable number of hospitalizations and the extra disease burden. RESULT: Overall, all the six kinds of pollutants had the strongest effects on CRSD inpatients within lag10 days. SO2 and CO caused the highest and lowest harm, respectively, and the RR values were SO2 (lag0-5): 1.1 20 (1.053, 1.191), and CO (lag0-6): 1.002 (1.001, 1.003). During the study period (January 1, 2014 to December 30, 2020), the 7-year cumulative burden of disease was 36.19 million CNY under the WHO air pollution standards. CONCLUSION: In general, we found that six air pollutants were risk factors for CRSD in Hefei City, and create a huge burden of disease.

The combined effects of exposure to multiple PM2.5 components on overweight and obesity in middle-aged and older adults: a nationwide cohort study from 125 cities in China.

The prevalence of overweight or obesity increased rapidly over the past decades in most countries, including China. However, little evidence exists about the effects of long-term exposure to PM2.5 components on overweight or obesity, particularly in developing countries. We measured different weight stages according to body mass index (BMI), and investigated the effects of exposure to PM2.5 components (ammonium [[Formula: see text]], sulfate [[Formula: see text]], nitrate [[Formula: see text]], black carbon and organic matter) on different BMI levels in middle-aged and elderly people of China. Our study explored the effects of single and multiple air pollution exposures on overweight and obesity by using the Generalized Linear Model and Quantile g-Computation model (QgC). This study found a significantly positive association between five PM2.5 components and overweight/obesity. In the QgC model, there was still a positive association between multiple exposure to PM2.5 components and overweight when all PM2.5 components were considered as a whole. In addition, males, the elderly, and urban residents were also more sensitive to five PM2.5 components.

Tension-compression asymmetry in amorphous silicon.

Hard and brittle materials usually exhibit a much lower strength when loaded in tension than in compression. However, this common-sense behaviour may not be intrinsic to these materials, but arises from their higher flaw sensitivity to tensile loading. Here, we demonstrate a reversed and unusually pronounced tension-compression asymmetry (tensile strength exceeds compressive strength by a large margin) in submicrometre-sized samples of isotropic amorphous silicon. The abnormal asymmetry in the yield strength and anelasticity originates from the reduction in shear modulus and the densification of the shear-activated configuration under compression, altering the magnitude of the activation energy barrier for elementary shear events in amorphous Si. In situ coupled electrical tests corroborate that compressive strains indeed cause increased atomic coordination (metallization) by transforming some local structures from sp3-bonded semiconducting motifs to more metallic-like sites, lending credence to the mechanism we propose. This finding opens up an unexplored regime of intrinsic tension-compression asymmetry in materials.

Immediate outcome prognostic value of plasma factors in patients with acute ischemic stroke after intravenous thrombolytic treatment.

In the present study, we explored multiple plasma factors to predict the outcomes of patients with AIS after IVT. Fifty AIS patients who received IVT with alteplase were recruited and divided into two groups according to their NIHSS scores. Serum from all subjects was collected to quantitatively analyze the levels of different plasma factors, IL-6, MMP-9, ADAMTS13, TNC, GSN and TRX, using Luminex assays or ELISA measurements. Compared with the levels assessed at the onset of AIS, the levels of MMP-9 (P < 0.001), ADAMTS13 (P < 0.001), and TRX (P < 0.001) significantly decreased after IVT. The level of IL-6 was significantly increased in the NIHSS > 5 group at admission (P < 0.001) compared to the NIHSS ≤ 5 group. AIS patients with a poor prognosis had lower levels of ADAMTS13 at 72 h post-IVT compared with patients with a good prognosis (P = 0.021). IL-6 also was notably higher in the poor outcome group (P = 0.012). After adjusting for confounders, ADAMTS13 at 72 h post-IVT was an independent protective factor for prognosis in AIS patients with an adjusted OR of 0.07 (P = 0.049), whereas IL-6 was an independent predictor of risk for AIS patients with an adjusted OR of 1.152 (P = 0.028). IVT decreased MMP-9, ADAMTS13, and TRX levels in the plasma of AIS patients. Patients with a NIHSS score of less than 5 exhibited lower IL-6 levels, indicating that increased levels of IL-6 correlated with AIS severity after IVT. Therefore, IL-6 and ADAMTS13 might be useful plasma markers to predict the prognosis in AIS patients at 90-days after IVT.

Individual PM2.5 component exposure model, elevated blood pressure and hypertension in middle-aged and older adults: A nationwide cohort study from 125 cities in China.

Recently, elevated blood pressure (BP) and hypertension (HTN) have caused a huge burden of health loss. Previous studies used ambient air pollutants as a proxy for individual exposure, limiting the assessment of its multiple exposure to health effects. For the first time, this study constructed individual PM2.5 component (SO42-, NO3-, NH4+, OM, and BC) exposure model DAG (Directed Acyclic Graph), DAG-oriented generalized linear model and random forest model, and explored the effects of single and multiple exposures to PM2.5 components on BP at different stages by the generalized linear model (GLM) and Quantile g-Computation (QgC) model based on a large cohort study in China. We defined BP in four stages according to the 2017 ACC/AHA guidelines. After excluding the lack of key information, the cohort analyses ultimately included 9031 participants. Our results showed that the individual PM2.5 component exposure model had good efficacy. Single or multiple exposure to PM2.5 components had significant positive effects on normal BP to elevated BP and elevated BP to stage 1 HTN. In addition, males, the elderly and urban residents were more sensitive to PM2.5 components. This study provided implications for environmental exposure assessment and control of particulate pollution in the future.

Interaction of biomass fuels use and metals exposure on hypertension: A prospective cohort study in rural areas along the Yangtze River, China.

Humans maybe simultaneously exposed to multiple-metals and indoor air pollution in daily life. However, limited prospective studies have assessed the interaction between multiple metals exposure and biomass fuels use on hypertension in China. The prospective cohort study in rural areas along the Yangtze River included 2625 adults in 2014-2015, and they were followed up till 2019. Among 1248 rural residents who were without hypertension at baseline, 377 hypertension events (30.21%) were observed after 4.5 years of average follow-up time. First-morning urine samples of residents were collected at baseline, the association between urinary metals level and hypertension were assessed using quantile g-computation. Additionally, we also examined the effect of biomass fuels use, fuels switching, and cookstove ventilation on the association of metals exposure with hypertension. Quantile g-computation analyses showed a positive joint effect of 17 metals on hypertension, with the odds ratio (OR) of 1.68 (95% CI: 0.89, 3.14) when increasing all seventeen metals by one quartile, and cadmium, lithium, copper contributed the largest positive weights. Biomass fuels use can interact with cadmium exposure on hypertension with OR for interaction of 1.28 (95%CI: 1.00, 1.73), and increase the association between copper, manganese and zinc exposure and systolic blood pressure, lithium exposure and diastolic blood pressure at the follow-up visit. Moreover, switching from biomass fuels to clean fuels during follow up, cookstove ventilation can alleviate the risk of higher blood pressure from metals exposure. In rural areas along the Yangtze River, China, biomass fuels use for cooking can interact with multiple-metals exposure on hypertension. Residents who switched from biomass fuels to clean fuels and who used ventilation had a lower risk of hypertension. Further cohort studies are needed to clarify the mechanism of combined effects of metals exposure and biomass fuels use on the human health.

Development of a real-time RT-PCR assay for the detection of pan-human parechoviruses.

BACKGROUND: Parechoviruses (PeV-As), which constitute a new genus within the family Picornaviridae, have been associated with numerous localized outbreaks of serious diseases, such as coryza, pneumonia, maculopapular exanthem, and conjunctivitis. However, to the best of our knowledge, only a few laboratories worldwide conduct tests for the identification of this group of viruses. Therefore, in this study, we aimed to develop and validate a real-time RT-PCR assay for the identification of PeV-As. METHODS: To design and validate a real-time PCR primer-probe targeting the 5'-UTR region of PeV-As, the 5'-UTR sequences of PeV-As available in GenBank were aligned using the MUSCLE algorithm in MEGA v7.0. Thereafter, the highly conserved 5'-UTR region was selected, and its primer-probe sequence was designed using Primer Premier v5.0. This primer-probe sequence was then evaluated for specificity, sensitivity, and repeatability, and for its validation, it was tested using fecal samples from 728 healthy children living in Beijing (China). RESULTS: The PeV-A real-time RT-PCR assay detected only the RNA-positive standards of PeV-A genotypes (1-8, 14, 17, and 18), whereas 72 serotypes of non-PeV-A EV viruses were undetected. In addition, the VP1 region of these 11 PeV-A genotypes that tested positive were amplified using the primers designed in this study. Typing results indicated that eight, one, and two strains of the 11 were PeV-A1, PeV-A4, and PeV-A6, respectively. We also determined and presented the genetic characterization and phylogenetic analyses results corresponding to these 11 VP1 region sequences. Furthermore, real-time RT-PCR assay showed good sensitivity with LOD of 102 copies/µL. Positive results in eight parallel experiments at each concentration gradient from 107 copies/µL to 102 copies/µL, indicating good repeatability. CONCLUSION: Our findings suggested that the real-time RT-PCR assay developed in this study can be applied for routine PeV-A identification. We detected PeV-A1, 4 and 6 genotypes in the 728 faecal samples using this method. Additionally, we believe that our results will serve as a foundation for further studies on PeV-As and facilitate the expansion of the gene sequence information available in GenBank.

Coxsackievirus B4: an underestimated pathogen associated with a hand, foot, and mouth disease outbreak.

In order to discover the causes of a coxsackievirus B4 (CV-B4)-associated hand, foot, and mouth disease (HFMD) outbreak and to study the evolutionary characteristics of the virus, we sequenced isolates obtained during an outbreak for comparative analysis with previously sequenced strains. Phylogenetic and evolutionary dynamics analysis was performed to examine the genetic characteristics of CV-B4 in China and worldwide. Phylogenetic analysis showed that CV-B4 originated from a common ancestor in Shandong. CV-B4 strains isolated worldwide could be classified into genotypes A-E based on the sequence of the VP1 region. All CV-B4 strains in China belonged to genotype E. The global population diversity of CV-B4 fluctuated substantially over time, and CV-B4 isolated in China accounted for a significant increase in the diversity of CV-B4. The average nucleotide substitution rate in VP1 of Chinese CV-B4 (5.20 × 10-3 substitutions/site/year) was slightly higher than that of global CV-B4 (4.82 × 10-3 substitutions/site/year). This study is the first to investigate the evolutionary dynamics of CV-B4 and its association with an HFMD outbreak. These findings explain both the 2011 outbreak and the global increase in CV-B4 diversity. In addition to improving our understanding of a major outbreak, these findings provide a basis for the development of surveillance strategies.

The relationship between inflammation and neurocognitive dysfunction in obstructive sleep apnea syndrome.

Obstructive sleep apnea syndrome (OSAS), a state of sleep disorder, is characterized by repetitive apnea, chronic hypoxia, oxygen desaturation, and hypercapnia. Previous studies have revealed that intermittent hypoxia (IH) conditions in OSAS patients elicited neuron injury (especially in the hippocampus and cortex), leading to cognitive dysfunction, a significant and extraordinary complication of OSAS patients. The repeated courses of airway collapse and obstruction in OSAS patients resulted in apnea and arousal during sleep, leading to IH and excessive daytime sleepiness (EDS) and subsequently contributing to the development of inflammation. IH-mediated inflammation could further trigger various types of cognitive dysfunction. Many researchers have found that, besides continuous positive airway pressure (CPAP) treatment and surgery, anti-inflammatory substances might alleviate IH-induced neurocognitive dysfunction. Clarifying the role of inflammation in IH-mediated cognitive impairment is crucial for potentially valuable therapies and future research in the related domain. The objective of this article was to critically review the relationship between inflammation and cognitive deficits in OSAS.

Actuating Supramolecular Shape Memorized Hydrogel Toward Programmable Shape Deformation.

Inspired by nature, diverse biomimetic hydrogel actuators are fabricated and become one of the most essential components of bionics research. Usually, the anisotropic structure of a hydrogel actuator is generated at the early fabrication process, only a specific shape transformation behavior can be produced under external stimuli, and thus has limited the development of hydrogel actuators toward the biomimetic shape deformation behavior. Herein, a novel bilayer hydrogel having a thermoresponsive actuating layer and a metal ion-responsive memorizing layer is proposed, therefore, a 2D hydrogel film can be fixed into various 3D shapes via supramolecular metal-ligand coordination, with further realizing programmable 4D shape deformation under the stimulus of temperature. By manipulating the temporary shapes via shape memory behavior, various temporary anisotropic structures can be obtained via the bilayer hydrogel, thus producing diverse reversible shape deformation performances, which is expected to promote the development of intelligent polymeric materials.

Ionic Strength and Thermal Dual-Responsive Bilayer Hollow Spherical Hydrogel Actuator.

As one of the most promising intelligent materials, polymeric hydrogel actuators could produce reversible shape change upon external stimuli. Although complex shape deformation from 2D to 3D have been achieved, the realization of actuating behavior from 3D to 3D is still a significant challenge. Herein, an effective strategy to develop a novel bilayer hollow spherical hydrogel actuator is proposed. Through immersing a Ca2+ incorporated gelatin core into alginate solution, an ionic-strength-responsive alginate layer will be formed along the gelatin core via alginate-Ca2+ crosslinks, and then another thermo-responsive alginate-poly(2-(dimethylamino)ethyl methacrylate)(Alg-PDMAEMA) layer is introduced to achieve a bilayer hydrogel with ionic strength and temperature dual responsiveness. A hollow hydrogel capsule could be obtained if a spherical gelatin core is applied, and it could produce complex shape deformations from 3D to 3D upon the trigger of ionic strength and temperatures changes. The present work may offer new inspirations for the development of novel intelligent polymeric hydrogel actuators.

Unprecedented Piezoresistance Coefficient in Strained Silicon Carbide.

Reports reveal that the piezoresistance coefficients of silicon carbide (SiC) nanowires (NWs) are 2 to 4 times smaller than those of their corresponding bulk counterparts. It is a challenge to eliminate contamination in adhering NWs onto substrates. In this study, a new setup was developed, in which NWs were manipulated and fixed by a goat hair and conductive silver epoxy in air, respectively, in the absence of any depositions. The goat hair was not consumed during manipulation of the NWs. The process took advantage of the stiffness and tapered tip of the goat hair, which is unlike the loss issue of beam sources in depositions. With the new fixing method, in situ transmission electron microscopy (TEM) electromechanical coupling measurements were performed on pristine SiC NWs. The piezoresistance coefficient and carrier mobility of SiC NW are -94.78 × 10-11 Pa-1 and 30.05 cm2 V-1 s-1, respectively, which are 82 and 527 times respectively greater than those of SiC NWs reported previously. We, for the first time, report that the piezoresistance coefficient of SiC NW is 17 times those of its bulk counterparts. These findings provide new insights to develop high performance SiC devices and to help avoid catastrophic failure when working in harsh environments.

Light-Promoted Nickel Catalysis: Etherification of Aryl Electrophiles with Alcohols Catalyzed by a NiII -Aryl Complex.

A highly effective C-O coupling reaction of (hetero)aryl electrophiles with primary and secondary alcohols is reported. Catalyzed by a NiII -aryl complex under long-wave UV (390-395 nm) irradiation in the presence of a soluble amine base without any additional photosensitizer, the reaction enables the etherification of aryl bromides and aryl chlorides as well as sulfonates with a wide range of primary and secondary aliphatic alcohols, affording synthetically important ethers. Intramolecular C-O coupling is also possible. The reaction appears to proceed via a NiI -NiIII catalytic cycle.