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In engineering measurements, metal foil strain gauges suffer from a limited range and low sensitivity, necessitating the development of flexible sensors to fill the gap. This paper presents a flexible, high-performance piezoresistive sensor using a composite consisting of graphene nanoplatelets (GNPs) and polydimethylsiloxane (PDMS). The proposed sensor demonstrated a significantly wider range (97%) and higher gauge factor (GF) (6.3), effectively addressing the shortcomings of traditional strain gauges. The microstructure of the GNPs/PDMS composite was observed using a scanning electron microscope, and the distribution of the conductive network was analyzed. The mechanical behavior of the sensor encapsulation was analyzed, leading to the determination of the mechanisms influencing encapsulation. Experiments based on a standard equal-strength beam were conducted to investigate the influence of the base and coating dimensions of the sensor. The results indicated that reducing the base thickness and increasing the coating length both contributed to the enhancement of the sensor's performance. These findings provide valuable guidance for future development and design of flexible sensors.
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In the field of wireless strain monitoring, it is difficult for the traditional metal-made antenna sensor to conform well with steel structures and monitor large strain deformation. To solve this problem, this study proposes a flexible antenna strain sensor based on a ductile graphene film, which features a 6.7% elongation at break and flexibility due to the microscopic wrinkle structure and layered stacking structure of the graphene film. Because of the use of eccentric embedding in the feeding form, the sensor can be miniaturized and can simultaneously monitor strain in two directions. The sensing mechanism of the antenna is analyzed using a void model, and an antenna is designed based on operating frequencies of 3 GHz and 3.5 GHz. The embedding size is optimized using a Smith chart and impedance matching principle. Both the simulation and experimental results verify that the resonant frequency and strain magnitude are linearly inversely proportional. The experimental results show that the strain sensitivity is 1.752 kHz/µÎµ along the geometric length and 1.780 kHz/µÎµ along the width, with correlation coefficients of 0.99173 and 0.99295, respectively.
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OBJECTIVE: The objective of this study is to investigate the gene-gene interactions associated with NSCL/P among DNA repair genes. DESIGN: This study included 806 NSCL/P case-parent trios from China. Quality control process was conducted for genotyped single nucleotide polymorphisms (SNPs) located in six DNA repair genes (ATR, ERCC4, RFC1, TYMS, XRCC1 and XRCC3). We tested gene-gene interactions with Cordell's method using statistical package TRIO in R software. Bonferroni corrected significance level was set as P = 4.24 × 10-4. We also test the robustness of the interactions by permutation tests. SETTING: Not applicable. PATIENTS/PARTICIPANTS: A total of 806 NSCL/P case-parent trios (complete trios: 682, incomplete trios: 124) with Chinese ancestry. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE(S): Not applicable. RESULTS: A total of 118 SNPs were extracted for the interaction tests. Fourteen pairs of significant interactions were identified after Bonferroni correction, which were confirmed in permutation tests. Twelve pairs were between ATR and ERCC4 or XRCC3. The most significant interaction occurred between rs2244500 in TYMS and rs3213403 in XRCC1(P = 8.16 × 10-15). CONCLUSIONS: The current study identified gene-gene interactions among DNA repair genes in 806 Chinese NSCL/P trios, providing additional evidence for the complicated genetic structure underlying NSCL/P. ATR, ERCC4, XRCC3, TYMS and RFC1 were suggested to be possible candidate genes for NSCL/P.
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OBJECTIVE: To explore the association between polymorphisms of transforming growth factor-ß (TGF-ß) signaling pathway and non-syndromic cleft lip with or without cleft palate (NSCL/P) among Asian populations, while considering gene-gene interaction and gene-environment interaction. METHODS: A total of 1 038 Asian NSCL/P case-parent trios were ascertained from an international consortium, which conducted a genome-wide association study using a case-parent trio design to investigate the genes affec-ting risk to NSCL/P. After stringent quality control measures, 343 single nucleotide polymorphism (SNP) spanning across 10 pivotal genes in the TGF-ß signaling pathway were selected from the original genome-wide association study(GWAS) dataset for further analysis. The transmission disequilibrium test (TDT) was used to test for SNP effects. The conditional Logistic regression models were used to test for gene-gene interaction and gene-environment interaction. Environmental factors collected for the study included smoking during pregnancy, passive smoking during pregnancy, alcohol intake during pregnancy, and vitamin use during pregnancy. Due to the low rates of exposure to smoking during pregnancy and alcohol consumption during pregnancy (<3%), only the interaction between maternal smoking during pregnancy and multivitamin supplementation during pregnancy was analyzed. The threshold for statistical significance was rigorously set at P =1.46×10-4, applying Bonferroni correction to account for multiple testing. RESULTS: A total of 23 SNPs in 4 genes yielded nominal association with NSCL/P (P<0.05), but none of these associations was statistically significant after Bonferroni' s multiple test correction. However, there were 6 pairs of SNPs rs4939874 (SMAD2) and rs1864615 (TGFBR2), rs2796813 (TGFB2) and rs2132298 (TGFBR2), rs4147358 (SMAD3) and rs1346907 (TGFBR2), rs4939874 (SMAD2) and rs1019855 (TGFBR2), rs4939874 (SMAD2) and rs12490466 (TGFBR2), rs2009112 (TGFB2) and rs4075748 (TGFBR2) showed statistically significant SNP-SNP interaction (P<1.46×10-4). In contrast, the analysis of gene-environment interactions did not yield any significant results after being corrected by multiple testing. CONCLUSION: The comprehensive evaluation of SNP associations and interactions within the TGF-ß signaling pathway did not yield any direct associations with NSCL/P risk in Asian populations. However, the significant gene-gene interactions identified suggest that the genetic architecture influencing NSCL/P risk may involve interactions between genes within the TGF-ß signaling pathway. These findings underscore the necessity for further investigations to unravel these results and further explore the underlying biological mechanisms.
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Labio Leporino , Fisura del Paladar , Interacción Gen-Ambiente , Estudio de Asociación del Genoma Completo , Polimorfismo de Nucleótido Simple , Transducción de Señal , Factor de Crecimiento Transformador beta , Humanos , Fisura del Paladar/genética , Labio Leporino/genética , Transducción de Señal/genética , Factor de Crecimiento Transformador beta/genética , Factor de Crecimiento Transformador beta/metabolismo , Femenino , Pueblo Asiatico/genética , Embarazo , Masculino , Predisposición Genética a la Enfermedad , Proteína smad3/genética , Factores de Riesgo , Proteína Smad2/genética , Proteína Smad2/metabolismo , Epistasis Genética , Contaminación por Humo de Tabaco/efectos adversos , Consumo de Bebidas Alcohólicas/genéticaRESUMEN
Objectives: This study aimed to compare fast-track surgery (FTS) and traditional perioperative care protocols in laparoscopic gynecological surgeries, assessing their impact on length of stay (LOS), recovery time, and postoperative complications. Methods: A case-control retrospective study was conducted at Suzhou Hospital of Integrated Chinese and Western Medicine, involving 167 patients undergoing laparoscopic gynecological surgery from June 2021 to June 2023. Of them, 81 patients underwent surgery based on the FTS protocol (FTS group) and 86 patients received a traditional perioperative management (control group). Patients in both groups underwent gynecologic laparoscopic procedures, including uterine, ovarian and tubal surgeries. Data were collected on general patients' characteristics, including age, BMI, surgery type and time, intestinal recovery and out-of-bed activity time, LOS, pain levels, and postoperative complications. Wilcoxon rank sum test with continuity correction was used to assess the difference in operative characteristics and postoperative pain levels. Fisher's exact test was used to assess the difference in overall frequency of postoperative complications between groups. Results: Patients in the FTS group exhibited faster intestinal recovery, shorter mobilization time, and reduced LOS compared to the control group. Pain levels were significantly lower at one, six and twelve hours post-surgery in the FTS group. Overall, the proportion of postoperative complications was significantly lower in the FTS group than in the control group. Conclusions: Implementing the FTS protocol in laparoscopic gynecological surgeries for benign conditions can reduce LOS, accelerate recovery, and minimize pain without increasing postoperative complications. Further research with more diverse patient populations is warranted to validate these findings.
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The folate-mediated one-carbon metabolism pathway is thought to play an important role in the etiology of non-syndromic oral clefts (NSOFC), although none of the genes in this pathway has shown significant signals in genome-wide association studies (GWAS). Recent evidence indicated that enhanced understanding could be gained by aggregating multiple SNPs effect simultaneously into polygenic risk score (PRS) to assess its association with disease risks. This study is aimed to assess the association between the genetic effect of folate-mediated one-carbon metabolism pathway and NSOFC risks using PRS based on a case-parent trio design. A total of 297 SNPs mapped from 18 genes in the folate-mediated one-carbon metabolism pathway were aggregated from a GWAS of 2458 case-parent trios recruited from an international consortium. We found a PRS based on the folate-mediated one-carbon metabolism pathway was significant among all NSOFC trios (OR = 1.95, 95% CI: 1.66-2.28, p = 2.39 × 10-16 ), as well as two major subtypes, non-syndromic cleft lip with or without cleft palate (NSCL/P) trios (OR = 1.71, 95% CI: 1.50-1.96, p = 7.66 × 10-15 ) and non-syndromic cleft palate only (NSCPO) trios (OR = 1.51, 95% CI: 1.36-1.68, p = 2.1 × 10-14 ). Similar results were also observed in further subgroup analyses stratified into Asian and European trios. The averaged PRS of the folate-mediated one-carbon metabolism pathway varied between the NSOFC case group and its comparison group (p < 0.05) with higher average PRS in the cases. Moreover, the top 5% pathway PRS group had 2.25 (95% CI: 1.85-2.73) times increased NSOFC risk, also 3.09 (95% CI: 2.50-3.81) and 2.06 (95% CI: 1.39-3.02) times increased risk of NSCL/P and NSCPO compared to the remainder of the distribution. The results of our study confirmed the folate-mediated one-carbon metabolism pathway was important in controlling risk to NSOFC and this study enhanced evidence towards understanding the genetic risks of NSOFC.
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Labio Leporino , Fisura del Paladar , Humanos , Fisura del Paladar/genética , Estudio de Asociación del Genoma Completo , Ácido Fólico , Labio Leporino/genética , Carbono , Polimorfismo de Nucleótido Simple , Predisposición Genética a la Enfermedad/genéticaRESUMEN
To assess the growth status of children with non-syndromic oral clefts (NSOC) and explore potential influencing factors. The data of NSOC children aged ≤5 years hospitalized between December 2018 and June 2020 were retrieved and evaluated, including their height, weight, NSOC subtypes and demographic characteristics before reparative surgeries. The growth status of the children was assessed using height-for-age Z-score (HAZ), weight-for-age Z-score (WAZ) and weight-for-height Z-score (WHZ). In total, 504 NSOC children (271 females & 233 males) were included. The proportion of stunting (HAZ <-2), underweight (WAZ <-2) and wasting (WHZ <-2) was 4.96%, 5.16% and 3.97%, respectively. In addition, we observed that HAZ and WAZ decreased with increasing age (both p < 0.01). Moreover, non-syndromic cleft palate only (NSCP) and non-syndromic cleft lip and palate (NSCLP) were associated with lower HAZ and WAZ compared with non-syndromic cleft lip only (NSCL) (all p < 0.01), while NSCLP was associated with a lower WHZ compared with NSCL (p < 0.01). The growth retardation and low weight rate of NSOC children under 5 years old were higher than the national average level and differed by the age of NSOC children and disease subtypes. Further improvements are warranted to promote the growth status of the NSOC-affected children.
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Labio Leporino , Fisura del Paladar , Masculino , Femenino , Humanos , Niño , Preescolar , Trastornos del CrecimientoRESUMEN
Discovering new bonding scenarios and subsequently exploring the reactivity contribute substantially to advance the main group element chemistry. Herein, we report on the isolation and characterization of an intriguing class of the hydrido-benzosiloles 2-4. These compounds exhibit a side arm of the amidinatosilylenyl group, featuring unidirectional silicon(II)/silicon(IV) donor-acceptor interaction on account of the geometric constraint. Furthermore, the reactions involving 2-4 with nitriles yield the tricyclic compounds that edge-fused of the Si-heteroimidazolidine-CN2 Si2 , silole-C4 Si, and phenyl-C6 -rings (5-13). These compounds are manifesting a unique reaction that the silicon(II)/silicon(IV) interaction enables the enamination of the α-H-bearing nitriles. The reaction mechanism involved in H-shift under oxidative addition at silylene followed by hydrosilylation of a ketenimine intermediate was revealed by density function theory (DFT) calculations.
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Electron-transferable oxidants such as B(C6 F5 )3 /nBuLi, B(C6 F5 )3 /LiB(C6 F5 )4 , B(C6 F5 )3 /LiHBEt3 , Al(C6 F5 )3 /(o-RC6 H4 )AlH2 (R=N(CMe2 CH2 )2 CH2 ), B(C6 F5 )3 /AlEt3 , Al(C6 F5 )3 , Al(C6 F5 )3 /nBuLi, Al(C6 F5 )3 /AlMe3 , (CuC6 F5 )4 , and Ag2 SO4 , respectively were employed for reactions with (L)2 Si2 C4 (SiMe3 )2 (C2 SiMe3 )2 (L=PhC(NtBu)2 , 1). The stable radical cation [1]+. was formed and paired with the anions [nBuB(C6 F5 )3 ]- (in 2), [B(C6 F5 )4 ]- (in 3), [HB(C6 F5 )3 ]- (in 4), [EtB(C6 F5 )3 ]- (in 5), {[(C6 F5 )3 Al]2 (µ-F)]- (in 6), [nBuAl(C6 F5 )3 ]- (in 7), and [Cu(C6 F5 )2 ]- (in 8), respectively. The stable dication [1]2+ was also generated with the anions [EtB(C6 F5 )3 ]- (9) and [MeAl(C6 F5 )3 ]- (10), respectively. In addition, the neutral compound [(L)2 Si2 C4 (SiMe3 )2 (C2 SiMe3 )2 ][µ-O2 S(O)2 ] (11) was obtained. Compounds 2-11 are characterized by UV-vis absorption spectroscopy, X-ray crystallography, and elemental analysis. Compounds 2-8 are analyzed by EPR spectroscopy and compounds 9-11 by NMR spectroscopy. The structure features are discussed on the central Si2 C4 -rings of 1, [1]+. , [1]2+ , and 11, respectively.
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Two borylaminoamidinatosilylenes (L)[(1,5-C8H14)B(Ar)N]Si (L = PhC(NtBu)2, Ar = 2,6-iPr2C6H3 (1)) and (L)[(1,5-C8H14)B(Ar')N]Si (Ar' = 2,4,6-Me3C6H2 (2)) have been prepared and utilized to investigate the reaction toward isocyanide. Reactions of 1 with the respective CN-2,6-Me2C6H3 and CNCy (Cy = cyclo-C6H11) produced compounds (L)Si(NAr)C(N-2,6-Me2C6H3)B(1,5-C8H14)(CN-2,6-Me2C6H3) (3) and (L)Si(NAr)C(NCy)C(NCy)B(1,5-C8H14)(CNCy) (4). Reactions of 2 with the respective CNCy and CN-2,6-Me2C6H3 yielded compounds cyclo-(L)SiN(Ar')C(NCy)B(1,5-C8H14)C(NCy) (5) and cyclo-(L)[(1,5-C8H14)B(Ar')N]SiC(CN-2,6-Me2C6H3)N(2,6-Me2C6H3)C(N-2,6-Me2C6H3) (6). Compounds 3-6 have different compositions and structures from each other. Density functional theory (DFT) calculations suggest initial formation of (L)[(1,5-C8H14)B(â:CN-2,6-Me2C6H3)(Ar)N]Si (A), (L)[(1,5-C8H14)B(â:CNCy)(Ar)N]Si (A'), (L)[(1,5-C8H14)B(â:CNCy)-(Ar')N]Si (Aâ³), and (L)[(1,5-C8H14)B(â:CN-2,6-Me2C6H3)(Ar')N]Si (Aâ´) as the respective intermediates. The as-followed transition states TS, TS1', TS1â³, and TSâ´ all feature probable Si:âC(âN):âB bonding with different Gibbs energies of 7.24, 2.46, 3.86, and 6.59 kcal/mol, respectively, due to variation among the Ar, Ar', 2,6-Me2C6H3, and Cy groups in these species, and reacted in different ways.
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ABSTRACT: Postoperative palatal fistula following primary cleft palate repair, especially wide and recurrent defects, presents significant challenges to management. When the fistula is surrounded by limited and scarred regional tissues, vascularized free flaps are recommended. The authors propose a novel method to repair a wide and recurrent palatal fistula resulting in excellent aesthetics and minor donor-site complications. The superficial circumflex iliac artery perforator flap was transferred with the application of intraoral anastomosis and supermicrosurgery techniques for palatal fistula closure.
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Fístula , Colgajo Perforante , Procedimientos de Cirugía Plástica , Anastomosis Quirúrgica , Estética Dental , Humanos , Arteria Ilíaca/cirugía , Colgajo Perforante/irrigación sanguínea , Complicaciones Posoperatorias , Procedimientos de Cirugía Plástica/métodosRESUMEN
The reaction of (LSi:)2 (1; L = PhC(NtBu)2) with 2 equiv of Me3SiC2C2SiMe3 resulted in the formation of (Me3SiC2)2(Me3Si)2C4Si2(L)2 (2). 2 exhibited a one-electron transfer when treated with 1 equiv of [Ph3C]+[B(C6F5)4]- to yield [(Me3SiC2)2(Me3Si)2C4Si2(L)2]·+[B(C6F5)4]- (3) and Ph3CCPh3, respectively. When compound 2 was treated with 2 equiv of AgOSO2CF3 a transfer of two electrons occurred to produce [(Me3SiC2)2(Me3Si)2C4Si2(L)2]2+·2[OSO2CF3]- (4) and elemental silver. The 1,4-disilabenzene 2 is disclosed of an open-shell singlet diradical character, and 3 and 4 are, respectively, the elusive stable radical cation and dication species of the 1,4-disilabenzene (2). Furthermore, 2 reacted with group 16 elements of O, S, and Se by oxidative addition to form (Me3SiC2)2(Me3Si)2C4Si2(L)2(µ-O2) (5) and (Me3SiC2)2(Me3Si)2C4Si2(L)2(µ-E) (E = S (6) and Se (7)), respectively.
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Two silylene molecules oxidatively react under formal [1 + 2 + 1]-cycloaddition to the C≡N bond of nitriles to yield 1-aza-2,4-disilabicyclo[1.1.0]butanes (L)(Cl)Si[µ-η1,2-NC(p-RC6H4)]Si(Cl)(L) (L = PhC(NtBu)2, R = CF3 (2), F (3), Cl (4), Br (5)). The strongly folded bicyclic SiCNSi cores in 2-5 feature inverted bridgehead carbon atoms and superelongated C-N bonds [1.745(12) to 1.801(2) Å], exceeding the lengths of C-N single bonds in known silaaziridines by up to 23%. Detailed bonding analysis discloses C-N bonding interactions, sharing far-reaching similarities with the central C-C bond in [1.1.1]propellane.
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Inflammation can cause a series of inflammatory lung disease, which seriously endangers human health. Pulmonary fibrosis is a kind of inflammatory disease with end-stage lung pathological changes. It has complicated and unknown pathogenesis and is still lack of effective therapeutic drugs. LPS-induced inflammation is a common feature of many infectious inflammations such as pneumonia, bacteremia, glomerulonephritis, etc. Evodiamine, one of the main components of Evodia rutaecarpa, is an alkaloid with excellent antiinflammatory effects. In this study, we evaluated the protective capacities of evodiamine on LPS-induced inflammatory damages in vitro and in vivo. MTT method, flow cytometry, immunofluorescence, and other methods were used for in vitro study to determine the protective capacities of evodiamine. The results suggest that evodiamine can protect murine macrophages from the LPS-nigericin-induced damages by (a) inhibiting cellular apoptosis, (b) inhibiting inflammatory cytokines releasing, and (c) activating the apelin pathway. We also used the exogenous apelin-13 peptide co-cultured with LPS-nigericin in RAW264.7 cells and found that apelin-13 contributes to protecting the effects of evodiamine. In vivo, the ELISA method and immunohistochemistry were used to examine inflammatory cytokines, apelin, and histological changes. BALB/c mice were exposed to LPS and subsequent administration of evodiamine ï¼p.o.ï¼for some time, the results of the alveolar lavage fluid and the tissue slices showed that evodiamine treatment alleviated the pulmonary inflammation and fibrosis, stimulated apelin expression and inhibited the inflammatory cytokines. These results provide a basis for the protective effect and mechanism of evodiamine in LPS-induced inflammation and suggest that it might be potential therapeutics in human pulmonary infections.
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Apelina/metabolismo , Evodia/química , Neumonía/tratamiento farmacológico , Quinazolinas/farmacología , Animales , Apoptosis/efectos de los fármacos , Citocinas/metabolismo , Fibrosis/tratamiento farmacológico , Humanos , Inflamación/tratamiento farmacológico , Inflamación/patología , Lipopolisacáridos/farmacología , Masculino , Ratones , Ratones Endogámicos BALB C , Extractos Vegetales/farmacología , Neumonía/patología , Células RAW 264.7RESUMEN
The silicon atom in LSiCl or LSiMes (L = PhC(NtBu)2, Mes = 2,4,6-Me3C6H2) inserts into the B-X bond of RBX2 (R = Ph, Mes, N(SiMe3)2; X = Cl, Br), which is followed by the migration of the amidinate ligand and the halide atom. By this way, LB(R)SiCl3 (R = Ph, 2; Mes, 3; N(SiMe3)2, 4) and LB(R)SiX2Mes (R = Ph, X = Cl, 5; R = Mes, X = Cl, 6; R = Mes, X = Br, 7) were obtained. Furthermore, a silylene-borane adduct LClSi â BPhCl2 (1) was obtained as an intermediate in the formation of compound 2. Compounds 2-7 are rare examples of borylhalosilanes.
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Melanoma is the deadliest form of skin cancer, and its incidence has continuously increased over the past 20 years. Therefore, the discovery of a novel targeted therapeutic strategy for melanoma is urgently needed. In our study, MTT-based cell proliferation assay, cell cycle, and apoptosis assays through flow cytometry, protein immunoblotting, protein immunoprecipitation, designing of melanoma xenograft models, and immunohistochemical/immunofluorescent assays were carried out to determine the detailed molecular mechanisms of a novel HSP90-PI3K dual inhibitor. Our compound, named DHP1808, was found to suppress A375 cell proliferation through apoptosis induction by activating the Fas/FasL signaling pathway; it also induced cell-cycle arrest and inhibited the cell migration and invasion of A375 cells by interfering with Hsp90-EGFR interactions and downstream signaling pathways. Our results indicate that DHP1808 could be a promising lead compound for the Hsp90/PI3K dual inhibitor.
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Fosfatidilinositol 3-Quinasa Clase I/antagonistas & inhibidores , Proteínas HSP90 de Choque Térmico/antagonistas & inhibidores , Melanoma/tratamiento farmacológico , Inhibidores de las Quinasa Fosfoinosítidos-3/farmacología , Neoplasias Cutáneas/tratamiento farmacológico , Puntos de Control del Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Fosfatidilinositol 3-Quinasa Clase I/metabolismo , Receptores ErbB/metabolismo , Proteínas HSP90 de Choque Térmico/metabolismo , Humanos , Melanoma/patología , Invasividad Neoplásica/patología , Piroptosis/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Neoplasias Cutáneas/patologíaRESUMEN
Reaction of the aluminum dialkynyl LAl(CCR)2 (L=N,N-chelate ligand and R=organic group) with B(C6 F5 )3 proceeds through an intermediate with Alâ â â η2 -C≡C side-on coordination to form the alumoles (2, 4, 6). A distinctive reaction pattern indicates a new facile synthetic route to aluminum-containing heterocycles. The synthetic process is described, and the characterization of compounds and computational calculations were carried out. Furthermore, alumoles 2 and 4 exhibit an aggregation-induced emission (AIE) of the bright yellow fluorescence.
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A collection of chiral spirocyclic tetrahydronaphthalene (THN)-oxindole hybrids bearing a quaternary carbon center at the ß-position of THN has been developed. The diastereodivergent direct catalytic Michael-aldol reaction between 3-ylideneoxindole and 2-methylbenzaldehyde was accomplished by using bifunctional tertiary amine. Simply changing the protecting group on the substrate in the organocatalytic cascade reaction led to inverted diastereoselectivity in good yields with a high ee value. To explain the diastereodivergence of the organocatalytic Michael-aldol cascade, we also proposed plausible transition-state models for [4 + 2] annulation based on the observed stereochemistry of the products.
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Direct sulfide organocatalysis is an emerging topic in research on synthetic chemistry. Here, an unprecedented sulfide-catalyzed diastereoselective [4+1] annulation of (in situ generated) ortho-quinone methides and bromides is reported. Notably, the robustness of such sulfide organocatalysis was demonstrated by performing the catalytic reaction under oxidative conditions without significantly affecting the reaction outcome. Various dihydrobenzofurans with diverse substituents were obtained with high isolated yields of up to 98% and remarkable diastereoselectivity (>19:1 dr in general).
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Compared with the intensively studied C3 spirooxindoles, limited reliable approaches are reported for synthesizing structurally analogous C2-spiropseudoindoxyl derivatives. Here, we developed an efficient method for highly diastereoselective synthesis of cyclopropane-fused spiropseudoindoxyl derivatives (up to 88% yield and >20 : 1 dr in all cases) through [2 + 1] annulation of (Z)-2-ylideneoxindoles with sulfur ylides.