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Reactions of ß-diketiminato alkaline earth alkyldiboranate derivatives [(BDI)Ae{pinBB(R)pin}] (BDI = HC{(Me)CNDipp}2; Dipp = 2,6-i-Pr2C6H3; Ae = Mg, R = n-Bu or Ae = Ca, R = n-hexyl) with t-BuNC provide access to the respective group 2 derivatives of unprecedented diborata-allyl, {(pinB)2CNBpin(t-Bu)}-, anions. Although the necessary mode of B-C bond cleavage implicated in these transformations could not be elucidated, further studies of the reactivity of magnesium triboranates toward isonitriles delivered a more general and rational synthetic access to analogous anionic moieties. Extending this latter reactivity to a less symmetric triboranate variant also provided an isomeric Mg-C-bonded dibora-alkyl species and sufficient experimental insight to prompt theoretical evaluation of this reactivity. DFT calculations, thus, support a reaction pathway predicated on initial RNC attack at a peripheral boron centre and the intermediacy of such dibora-alkyl intermediates.
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The bimetallic species, [{SiNDipp}MgNa]2 [{SiNDipp} = {CH2SiMe2N(Dipp)}2; (Dipp = 2,6-i-Pr2C6H3)], is shown to be a potent reducing agent, able to effect one- or two-electron reduction of either dioxygen, TEMPO, anthracene, benzophenone, or diphenylacetylene. In most cases, the bimetallic reaction products imply that the dissimilar alkaline metal centers react with a level of cooperativity. EPR analysis of the benzophenone-derived reaction and the concurrent isolation of [{SiNDipp}Mg(OCPh2)2], however, illustrate that treatment with such reducible, but O-basic, species can also result in reactivity in which the metals provide independent reaction products. The notable E-stereochemistry of the diphenylacetylene reduction product prompted a computational investigation of the PhC≡CPh addition. This analysis invokes a series of elementary steps that necessitate ring-opening via Mg+ â Na+ amido group migration of the SiNDipp ligand, providing insight into the previously observed lability of the bidentate dianion and its consequent proclivity toward macrocyclization.
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Counter to synthetic convention and expectation provided by the relevant standard reduction potentials, the chloroberyllate, [{SiNDipp}BeClLi]2 [{SiNDipp} = {CH2SiMe2N(Dipp)}2; Dipp = 2,6-i-Pr2C6H3)], reacts with the group 1 elements (M = Na, K, Rb, Cs) to provide the respective heavier alkali metal analogues, [{SiNDipp}BeClM]2, through selective reduction of the Li+ cation. Whereas only [{SiNDipp}BeClRb]2 is amenable to reduction by potassium to its nearest lighter congener, these species may also be sequentially interconverted by treatment of [{SiNDipp}BeClM]2 by the successively heavier group 1 metal. A theoretical analysis combining density functional theory (DFT) with elemental thermochemistry is used to rationalise these observations, where consideration of the relevant enthalpies of atomisation of each alkali metal in its bulk metallic form proved crucial in accounting for experimental observations.
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Like the previously reported potassium-based system, rubidium and cesium reduction of [{SiNDipp}AlI] ({SiNDipp} = {CH2SiMe2NDipp}2) with the heavier alkali metals [M = Rb and Cs] provides dimeric group 1 alumanyl derivatives, [{SiNDipp}AlM]2. In contrast, similar treatment with sodium results in over-reduction and incorporation of a formal equivalent of [{SiNDipp}Na2] into the resultant sodium alumanyl species. The dimeric K, Rb, and Cs compounds display a variable efficacy toward the C-H oxidative addition of arene C-H bonds at elevated temperatures (Cs > Rb > K, 110 °C) to yield (hydrido)(organo)aluminate species. Consistent with the synthetic experimental observations, computational (DFT) assessment of the benzene C-H activation indicates that rate-determining attack of the Al(I) nucleophile within the dimeric species is facilitated by π-engagement of the arene with the electrophilic M+ cation, which becomes increasingly favorable as group 1 is descended.
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The potassium diamidoalumanyl, [K{Al(SiNDipp)}]2 (SiNDipp = {CH2SiMe2NDipp}2), reacts with the terminal B-O bonds of pinacolato boron esters, ROBpin (R = Me, i-Pr), and B(OMe)3 to provide potsassium (alkoxy)borylaluminate derivatives, [K{Al(SiNDipp)(OR)(Bpin)}]n (R = Me, n = 2; R = i-Pr, n = ∞) and [K{Al(SiNDipp)(OMe)(B(OMe)2)}]∞, comprising Al-B σ bonds. An initial assay of the reactivity of these species with the heteroallene molecules, N,N'-diisopropylcarbodiimide and CO2, highlights the kinetic inaccessibility of their Al-B bonds; only decomposition at high temperature is observed with the carbodiimide, whereas CO2 preferentially inserts into the Al-O bond of [K{Al(SiNDipp)(OMe)(Bpin)}]2 to provide a dimeric methyl carbonate species. Treatment of the acyclic dimethoxyboryl species, however, successfully liberates a terminal alumaboronic ester featuring trigonal N2Al-BO2 coordination environments at both boron and aluminum.
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The copper(i) alumanyl derivative, [{SiNDipp}Al-Cu(NHCiPr)] (SiNDipp = {CH2SiMe2NDipp}2; Dipp = 2,6-di-isopropylphenyl; NHCiPr = N,N'-di-isopropyl-4,5-dimethyl-2-ylidene), reacts in a stepwise fashion with up to three equivalents of various terminal alkynes. This reactivity results in the sequential formation of cuprous (hydrido)(alkynyl)aluminate, (alkenyl)(alkynyl)aluminate and bis(alkynyl)aluminate derivatives, examples of which have been fully characterised. The process of alkene liberation resulting from the latter reaction step constitutes a unique case of alkyne transfer semi-hydrogenation in which the C-H acidic alkyne itself acts as a source of proton, with the Cu-Al bond providing the requisite electrons to effect reduction. This reaction sequence is validated by DFT calculations, which rationalise the variable stability of the initially formed heterobimetallic hydrides.
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[{SiNDipp}MgNa]2 ({SiNDipp} = {CH2SiMe2N(Dipp)}2; Dipp = 2,6-i-Pr2C6H3) reacts directly with H2 to provide a heterobimetallic hydride. Although the transformation is complicated by the simultaneous disproportionation of magnesium, computational density functional theory (DFT) studies suggest that this reactivity is initiated by orbitally-constrained and interactions between the frontier MOs of both H2 and the tetrametallic core of [{SiNDipp}MgNa]2.
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Ionic compounds containing sodium cations are notable for their stability and resistance to redox reactivity unless highly reducing electrical potentials are applied. Here we report that treatment of a low oxidation state {Mg2 Na2 } species with non-reducible organic bases induces the spontaneous and completely selective extrusion of sodium metal and oxidation of the MgI centers to the more conventional MgII state. Although these processes are also characterized by a structural reorganisation of the initially chelated diamide spectator ligand, computational quantum chemical studies indicate that intramolecular electron transfer is abetted by the frontier molecular orbitals (HOMO/LUMO) of the {Mg2 Na2 } ensemble, which arise exclusively from the 3s valence atomic orbitals of the constituent sodium and magnesium atoms.
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Diabetic cardiomyopathy (DCM) is one of the main complications of diabetic patients and the major reason for the high prevalence of heart failure in diabetic patients. Fufang Xueshuantong (FXST) is a traditional Chinese medicine formula commonly used in the treatment of diabetic retinopathy and stable angina pectoris. However, the role of FXST in DCM has not yet been clarified. This study was conducted to investigate the effects of FXST on diabetic myocardial lesions and reveal its molecular mechanism. The rats were intraperitoneally injected with 65 mg/kg streptozotocin (STZ) to induce diabetes mellitus (DM). DM rats were given saline or FXST. The rats in the control group were intraperitoneally injected with an equal amount of sodium citrate buffer and gavaged with saline. After 12 weeks, echocardiography, heart weight index (HWI), and myocardial pathological changes were determined. The expression of transforming growth factor-beta1 (TGF-ß1), collagen I, and collagen III was examined using immunofluorescence staining and western blot. The expressions of Wnt/ß-catenin signaling pathway-related proteins and mRNA were detected by western blot and real-time PCR. The results showed that FXST significantly improved cardiac function, ameliorated histopathological changes, and decreased HWI in the DM rats. FXST significantly inhibited the expression of myocardial TGF-ß1, collagen I, and collagen III in DM rats. Furthermore, FXST significantly inhibited the Wnt/ß-catenin pathway. Taken together, FXST has a protective effect on DCM, which might be mediated by suppressing the Wnt/ß-catenin pathway.
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Objective: Non-alcoholic fatty liver disease (NAFLD) is one of the leading causes of chronic liver disease. The controlled attenuation parameter (CAP) obtained by FibroScan reflects the level of liver steatosis in patients with obesity. Our study aimed to construct a simple equation to predict the CAP, to facilitate the screening and monitoring of patients at high risk for NAFLD. Methods: A total of 272 subjects were randomly divided into derivation and validation cohorts at a ratio of 1:2. The derivation set was used for constructing a multiple linear regression model; the validation set was used to verify the validity of the model. Results: Several variables strongly correlated with the CAP were used to construct the following equation for predicting CAP values:CAP1 = 2.4 × BMI + 10.5 × TG+ 3.6 × NC + 10.3 × CP +31.0, where BMI is body mass index, TG is triglyceride, NC is neck circumference and CP is C-peptide. The CAP1 model had an R 2 of 0.764 and adjusted R 2 of 0.753. It was then simplified to derive CAP2 included only simple anthropometric parameters: CAP2 = 3.5 × BMI + 4.2 × NC + 20.3 (R 2 = 0.696, adjusted R 2 = 0.689). The data were well fitted by both models. In the verification group, the predicted (CAP1 and CAP2) values were compared to the actual CAP values. For the CAP1 equation, R 2 = 0.653, adjusted R 2 = 0.651. For the CAP2 equation, R 2 = 0.625, adjusted R 2 = 0.623. The intra-class correlation coefficient (ICC) values were 0.781 for CAP1 and 0.716 for CAP2 (p < 0.001). The actual CAP and the predicted CAP also showed good agreement in Bland-Altman plot. Conclusion: The equations for predicting the CAP value comprise easily accessible variables, and showed good stability and predictive power. Thus, they can be used as simple surrogate tools for early screening and follow-up of NAFLD in the Chinese population.
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Objective: Visceral obesity, reflected by the amount of visceral adipose tissue (VAT), is associated with multiple chronic diseases and metabolic disorders. The visceral fat area (VFA), measured by MRI, is the 'gold standard' for diagnosis of visceral obesity. In this study, a simple model to predict VFA was constructed to facilitate the identification and monitoring of patients who are at high risk of visceral obesity. Methods: The 721 overweight and obese participants were divided into two groups according to sex, then randomly assigned to derivation and validation cohorts in a 1:2 ratio. Data from the derivation group were used to construct a multiple linear regression model; data from the validation group were used to verify the validity of the model. Results: The following prediction equations, applicable to both sexes, were developed based on age, waist circumference (WC) and neck circumference (NC) that exhibited strong correlations with the VFA: VFA=3.7×age+2.4×WC+5.5×NC-443.6 (R2 = 0.511, adjusted R2 = 0.481, for men) and VFA=2.8×age+1.7×WC+6.5×NC-367.3 (R2 = 0.442, adjusted R2 = 0.433, for women). The data demonstrated good fit for both sexes. A comparison of the predicted and actual VFA in the verification group confirmed the accuracy of the equations: for men, R2 = 0.489, adjusted R2 = 0.484 and intra-class correlation coefficient (ICC) = 0.653 (p < 0.001) and for women: R2 = 0.538, adjusted R2= 0.536 and ICC = 0.672 (p < 0.001). The actual and predicted VFAs also showed good agreement in a Bland-Altman plot, indicating the significant correlations of both equations with the actual VFA. Conclusions: Based on readily available anthropometric data, VFA prediction equations consisting of age, WC and NC were developed. The equations are robust, with good predictive power in both sexes; they provide ideal tools for the early detection of visceral obesity in Chinese overweight and obese individuals.
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Grasa Intraabdominal , Sobrepeso , Preescolar , China/epidemiología , Femenino , Humanos , Lactante , Grasa Intraabdominal/diagnóstico por imagen , Masculino , Obesidad/diagnóstico , Obesidad Abdominal/diagnóstico , Sobrepeso/diagnósticoRESUMEN
The reactivity of a seven-membered cyclic potassium diamidoalumanyl toward a variety of ketone small molecules has been assessed. Whilst acetophenone generates an aluminium pinacolate derivative, reductive C-C coupling is induced between the ketyl and ortho-carbon centres of two equivalents of benzophenone. In contrast, whereas oxidative addition of an enolisable proton is observed with 2,4-dimethyl-3-pentanone, 2,2,4,4-tetramethyl-3-pentanone undergoes an unprecedented hydroalumination process, where the reducing hydride may be traced to intramolecular oxidative addition of a (sp3)C-H bond.
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Objective: Vascular endothelial dysfunction is considered an early predictor of endothelial injury and the initiating factor of atherosclerosis (AS). Brachial artery flow-mediated dilation (FMD) can detect endothelial injury early and provide important prognostic information beyond traditional cardiovascular (CV) risk factors. This study aimed to find the influencing factors of FMD and develop a simple prediction model in populations with different body mass indices (BMIs). Methods: In total, 420 volunteers with different BMIs were recruited in our study. Subjects were randomly assigned to the derivation and validation cohorts (the ratio of the two was 1:2) with simple random sampling. The former was used for influencing factors searching and model construction of FMD and the latter was used for verification and performance evaluation. Results: The population was divided into two groups, i.e., 140 people in the derivation group and 280 people in the verification group. Analyzing in the training data, we found that females had higher FMD than males (p < 0.05), and FMD decreased with age (p < 0.05). In people with diabetes, hypertension or obesity, FMD was lower than that in normal individuals (p < 0.05). Through correlation analysis and linear regression, we found the main influencing factors of FMD: BMI, age, waist-to-hip radio (WHR), aspartate aminotransferase (AST) and low-density lipoprotein (LDL). And we developed a simple FMD prediction model: FMD = -0.096BMI-0.069age-4.551WHR-0.015AST-0.242LDL+17.938, where R2 = 0.599, and adjusted R2 = 0.583. There was no statistically significant difference between the actual FMD and the predicted FMD in the verification group (p > 0.05). The intra-class correlation coefficient (ICC) was 0.77. In a Bland-Altman plot, the actual FMD and the predicted FMD also showed good agreement. This prediction model had good hints in CV risk stratification (area under curve [AUC]: 0.780, 95 % confidence intervals [95% CI]: 0.708-0.852, p < 0.001), with a sensitivity and specificity of 73.8 and 72.1%, respectively. Conclusions: Males, older, obesity, hypertension, diabetes, smoking, etc. were risk factors for FMD, which was closely related to CV disease (CVD). We developed a simple equation to predict FMD, which showed good agreement between the training and validation groups. And it would greatly simplify clinical work and may help physicians follow up the condition and monitor therapeutic effect. But further validation and modification bears great significance.
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BACKGROUND: The morbidity and mortality of community-acquired pneumonia are relatively high, but many pneumonia pathogens cannot be identified accurately. As a new pathogen detection technology, metagenomic next-generation sequencing (mNGS) has been applied more and more clinically. We aimed to evaluate the diagnostic significance of mNGS for community-acquired pneumonia (CAP) in the south of China. METHODS: Our study selected CAP patients who visited the 3rd Xiangya Hospital from May 2019 to April 2021. Pathogens in bronchoalveolar lavage fluid (BALF) specimens were detected using mNGS and traditional microbiological culture. mNGS group: detected by both mNGS and BALF culture; control group: detected only by BALF or sputum culture. The diagnostic performance of pathogens and the antibiotic adjustments were compared within mNGS group. RESULTS: The incidence of acute respiratory distress syndrome (ARDS) was 28.3% in the mNGS group and 17.3% in the control group. Within the mNGS group, the positive rate of pathogens detected by mNGS was 64%, thus by BALF culture was only 28%. Pathogens detected by mNGS were consisted of bacteria (55%), fungi (18%), special pathogens (18%), and viruses (9%). The most detected pathogen by mNGS was Chlamydia psittaci. Among the pathogen-positive cases, 26% was not pathogen-covered by empirical antibiotics, so most of which were made an antibiotic adjustment. CONCLUSIONS: mNGS can detect pathogens in a more timely and accurate manner and assist clinicians to adjust antibiotics in time. Therefore, we recommend mNGS as the complementary diagnosis of severe pneumonia or complicated infections.
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Reactions of the seven-membered heterocyclic potassium diamidoalumanyl, [K{Al(SiNDipp)}]2 (SiNDipp = {CH2SiMe2NDipp}2; Dipp = 2,6-di-isopropylphenyl), with a variety of Cu(I), Ag(I) and Au(I) chloride N-heterocyclic carbene (NHC) adducts are described. The resultant group 11-Al bonded derivatives have been characterised in solution by NMR spectroscopy and, in the case of [{SiNDipp}Al-Au(NHCiPr)] (NHCiPr = N,N'-di-isopropyl-4,5-dimethyl-2-ylidene), by single crystal X-ray diffraction. Although similar reactions of LAgCl and LAuCl, where L is a more basic cyclic alkyl amino carbene (CAAC), generally resulted in reduction of the group 11 cations to the base metals, X-ray analysis of [(CyCAAC)AgAl(SiNDipp)] (CyCAAC = 2-[2,6-bis(1-methylethyl)phenyl]-3,3-dimethyl-2-azaspiro[4.5]dec-1-ylidene) provides the first solid-state authentication of an Ag-Al σ bond. The reactivity of the NHC-supported Cu, Ag and Au alumanyl derivatives was assayed with the isoelectronic unsaturated small molecules, N,N'-di-isopropylcarbodiimide and CO2. While these reactions generally provided products consistent with nucleophilic attack of the group 11 atom at the electrophilic heteroallene carbon centre, treatment of the NHC-supported copper and silver alumanyls with N,N'-di-isopropylcarbodiimide yielded less symmetric Cu-C and Ag-C-bonded isomers. In contrast to the previously described copper and silver alumanyl derivatives, [(NON)Al(O2C)M(Pt-Bu3)] (M = Cu or Ag; NON = 4,5-bis(2,6-di-isopropylanilido)-2,7-di-tert-butyl-9,9-dimethylxanthene), which were prone to facile CO extrusion and formation of carbonate derivatives, the NHC-supported dioxocarbene species, [(NHCiPr)M(CO2)Al(SiNDipp)] (M = Cu, Ag, Au), are all stable at room and moderately elevated temperatures. The stabilising role of the NHC co-ligand was, thus, assessed by preparation of the t-Bu3P adducted copper-alumanyl, [(t-Bu3P)CuAl(SiNDipp)]. Treatment of this latter compound, which was also structurally characterised by X-ray analysis, with both N,N'-di-isopropylcarbodiimide and CO2 again provided smooth heteroallene insertion and formation of the relevant Cu-C-bonded products. Although both compounds were quite stable at room temperature, heating of [(t-Bu3P)Cu(CO2)Al(SiNDipp)] at 60 °C induced elimination of CO and formation of the analogous carbonate, [(t-Bu3P)Cu(OCO2)Al(SiNDipp)], which was identified by 13C and 31P NMR spectroscopy. Reflective of the more reliable nucleophilic behaviour of the gold centres in these group 11 alumanyls, computational (QTAIM and NBO) analysis highlighted a lower level of covalency of the Al-Au linkage in comparison to the analogous Al-Cu and Al-Ag interactions. Although substitution of the co-ligand significantly perturbs the charge distribution across the Cu-Al bond of [LCuAl(SiNDipp)] (L = NHCiPr or t-Bu3P), only a negligible difference is observed between the phosphine-coordinated copper systems derived from either the [SiNDipp]- or (NON)-based alumanyl ligands. Computational mapping of the reaction profiles arising from treatment of the various group 11 alumanyls with N,N'-di-isopropylcarbodiimide indicates that the observed formation of the Cu-N and Ag-N bound isomers do not provide the thermodynamic reaction outcome. In contrast, examination of the CO2-derived reactions, and their potential toward CO extrusion and subsequent carbonate formation, implies that the identity of the co-ligand exerts a greater influence on this aspect of reactivity than the architecture of the diamidoalumanyl anion.
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Background: High expression of chemokine (C-X3-C motif) receptor 1 (CX3CR1) was shown to contribute to the progression of many fibrotic diseases. However, there is still no study for the role of CX3CR1 in idiopathic pulmonary fibrosis (IPF). Therefore, we aimed to identify CX3CR1-related immune infiltration genes (IIGs) in IPF and establish a combined risk model to evaluate the prognosis of IPF. Methods: A discovery cohort of IPF patients (GSE70867) was downloaded from the Gene Expression Omnibus dataset. We identified the composition of 22 kinds of immune cells infiltration by CIBERSORT. The Cox regression model with the LASSO method was used for identifying prognostic genes and developing CX3CR1-related IIGs. Kaplan-Meier was applied to plot the survival curve of prognosis model. Peripheral blood mononuclear cell (PBMC) and bronchoalveolar lavage fluid (BALF) were collected to be tested by quantitative reverse transcriptase-PCR (qRT-PCR) from 15 clinical samples, including 8 healthy controls (HC), 4 patients with usual interstitial pneumonia (UIP) and 3 patients with pulmonary fibrosis (FIB). Results: We found that high expression of CX3CR1 in BALF contributed to the poor prognosis in IPF patients. ALR4C, RAB37, GPR56, MARCKS, PXN and RASSF2 were identified as CX3CR1-related IIGs, which were highly expressed in PBMC of UIP/FIB patients than that of HC. Moreover, the expression of PXN was higher in FIB patients' PBMC than that of UIP ones. In the cohort of IPF patients, high infiltration of activated NK cells in BALF caused poor survival compared to low infiltration group. The infiltration of activated NK was regulated by CX3CR1-related IIGs. The combined risk model predicted that high expression of CX3CR1-related IIGs and high infiltrated activated NK cells caused poor prognosis in IPF patients. Conclusion: We identified a group of CX3CR1-related IIGs in IPF patients. This combined risk model provided new insights in the prognosis and therapy of IPF.
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Fibrosis Pulmonar Idiopática , Líquido del Lavado Bronquioalveolar , Receptor 1 de Quimiocinas CX3C/genética , Estudios de Cohortes , Humanos , Fibrosis Pulmonar Idiopática/metabolismo , Leucocitos Mononucleares/metabolismo , PronósticoRESUMEN
ETHNOPHARMACOLOGICAL RELEVANCE: Euonymus alatus (Thunb.) Siebold (family Celastraceae) is a deciduous woody shrub that is recorded in ShenNong BenCaoJing. It has been widely used for diabetes in traditional Chinese medicine. AIM OF THE STUDY: This study aimed to identify the most effective extract of Euonymus alatus (EA) against high glucose-induced endothelial cells in vitro, evaluate its pharmacological effect on retinopathy in diabetic mice and explore its underlying mechanism by RNA sequencing. METHODS: Retinal vascular endothelial cells (RF/6A) were treated with normal glucose (5.5 mmol/L glucose), high glucose (25 mmol/L glucose) or high glucose plus methanol extracts of EA (MEA), ethyl acetate extracts of EA (EEA) or water extracts of EA (WEA). The cytotoxicity and cell viability were determined by Cell Counting Kit-8 (CCK-8) assay. Cell migration was examined using the Transwell assay, and tube formation ability was measured using the Matrigel assay. Then, the KK-Ay mice were administered WEA or water for 12 weeks. The velocities of ocular blood flow were determined by Doppler ultrasound. RNA sequencing and reverse transcription quantitative PCR (RT-qPCR) were performed on WEA-stimulated RF/6A cells to reveal the underlying mechanism. RESULTS: The cytotoxicity assay found that 30 µg/mL MEA, 20 µg/mL EEA and 30 µg/mL WEA had no toxic effect on RF/6A cells. The cell viability results showed that MEA, EEA and WEA all decreased cell viability. Compared with the high-glucose group, both MEA and WEA decreased the number of migrated cells, while the inhibition rate of WEA was higher. The Matrigel results showed that 30 µg/mL WEA effectively reduced the total tube length. Moreover, WEA improved the haemodynamics of the central retinal artery. RNA sequencing coupled with RT-qPCR verified that WEA regulated angiogenesis-related factors in high glucose-stimulated RF/6A cells. CONCLUSIONS: WEA inhibits the migration and tube formation of RF/6A cells and improves diabetic retinopathy (DR) by mediating angiogenesis.
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Supervivencia Celular/efectos de los fármacos , Medicamentos Herbarios Chinos/uso terapéutico , Euonymus/química , Fitoterapia , Animales , Glucemia/efectos de los fármacos , Línea Celular , Movimiento Celular/efectos de los fármacos , Diabetes Mellitus , Medicamentos Herbarios Chinos/química , Glucosa/toxicidad , Haplorrinos , Masculino , Ratones , Ratones Endogámicos ARESUMEN
Sodium reduction of [{SiNDipp}Mg] [{SiNDipp} = {CH2SiMe2N(Dipp)}2; Dipp = 2,6-i-Pr2C6H3] provides the Mg(I) species, [{SiNDipp}MgNa]2, in which the long Mg-Mg bond (>3.2 Å) is augmented by persistent Na-aryl interactions. Computational assessment indicates that this molecule is best considered to comprise a contiguous tetrametallic core, a viewpoint borne out by its reaction with CO, which results in ethynediolate formation mediated by the dissimilar metal centers.
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The seven-membered cyclic potassium alumanyl species, [{SiNMes }AlK]2 [{SiNMes }={CH2 SiMe2 N(Mes)}2 ; Mes=2,4,6-Me3 C6 H2 ], which adopts a dimeric structure supported by flanking K-aryl interactions, has been isolated either by direct reduction of the iodide precursor, [{SiNMes }AlI], or in a stepwise manner via the intermediate dialumane, [{SiNMes }Al]2 . Although the intermediate dialumane has not been observed by reduction of a Dipp-substituted analogue (Dipp=2,6-i-Pr2 C6 H3 ), partial oxidation of the potassium alumanyl species, [{SiNDipp }AlK]2 , where {SiNDipp }={CH2 SiMe2 N(Dipp)}2 , provided the extremely encumbered dialumane [{SiNDipp }Al]2 . [{SiNDipp }AlK]2 reacts with toluene by reductive activation of a methyl C(sp3 )-H bond to provide the benzyl hydridoaluminate, [{SiNDipp }AlH(CH2 Ph)]K, and as a nucleophile with BPh3 and RN=C=NR (R=i-Pr, Cy) to yield the respective Al-B- and Al-C-bonded potassium aluminaborate and alumina-amidinate products. The dimeric structure of [{SiNDipp }AlK]2 can be disrupted by partial or complete sequestration of potassium. Equimolar reactions with 18-crown-6 result in the corresponding monomeric potassium alumanyl, [{SiNDipp }Al-K(18-cr-6)], which provides a rare example of a direct Al-K contact. In contrast, complete encapsulation of the potassium cation of [{SiNDipp }AlK]2 , either by an excess of 18-cr-6 or 2,2,2-cryptand, allows the respective isolation of bright orange charge-separated species comprising the 'free' [{SiNDipp }Al]- alumanyl anion. Density functional theory (DFT) calculations performed on this moiety indicate HOMO-LUMO energy gaps in the of order 200-250â kJ mol-1 .
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Gastric cancer (GC) is one of the most common malignancies and has the second highest lethal rate in the world; thus, finding new medicines with high potency and low toxicity is urgent. Cudrania tricuspidata (Carr.) Bur. ex Lavallee (Moraceae) is a traditional medicinal herb that is considered to have antitumour efficacy. We extracted and isolated cudraxanthone L (CXL) from Cudrania tricuspidata and evaluated its anti-cancer efficacy. CXL treatment inhibited angiogenesis of chorioallantoic membrane (CAM) and repressed the cell viability of various human cancer cells, indicating it presented the antitumour potential. Among them, CXL presented the best inhibitory effects on MGC803 cells. In addition, the invasion, migration and clonogenicity were significantly repressed, S phase of the cell cycle was arrested, and apoptosis was induced when MGC803 cells were treated with CXL. The results of RNA sequencing, qRT-PCR and western blotting verified that CXL regulated the MAPK signalling pathway and induced apoptosis by FAS-mediated pathway. The in vivo data revealed that CXL arrested tumour growth without toxic effects and upregulated the protein levels in FAS-mediated pathway in MGC803 gastric cancer-bearing mice. In summary, we demonstrate CXL presents impactful anti-GC efficacy by regulating the MAPK signalling pathway and promoting the FAS-mediated pathway.