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Small Cu clusters are excellent candidates for the electrocatalytic reduction of carbon dioxide (CO2RR), and their catalytic performance is expected to be significantly influenced by the interaction between the substrate and cluster. In this study, we systematically investigate the CO2RR for a Cu3 cluster anchored on Janus MoSX (X = Se, Te) substrates using density functional theory calculations. These substrates feature a broken vertical mirror symmetry, which generates spontaneous out-of-plane polarization and offers two distinct polar surfaces to support the Cu3 cluster. Our findings reveal that the CO2RR performance on the Cu3 cluster is strongly influenced by the polarization direction and strength of the MoSX (X = Se, Te) substrates. Notably, the Cu3 cluster supported on the S-terminated MoSTe surface (Cu3(S)@MoSTe) demonstrates the highest CO2RR activity, producing methane. These results underscore the pivotal role of substrate polarization in modulating the binding strength of reactants and reaction intermediates, thereby enhancing the CO2RR efficiency.
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BACKGROUND: Congenital unilateral renal agenesis (URA) is a kind of rare birth defect during fetal development with varies clinical phenotypes. The pathogenesis and the relationship between gene and phenotype are still unclear. METHODS: Ten URA fetuses were followed up after birth using postnatal renal ultrasound examination to confirm the diagnosis with nine children were URA and one was Renal Ectopy (RE). Trio- WES, CNV- seq were performed with the 10 children and their close relatives. RESULTS: There were 3 heterozygous variants of CHD7, PROKR2 and NRIP1 genes were identified in 3 children, respectively. CHD7 (c.2663T>C, p.M888T) is classified as likely pathogenic (LP), PROKR2 (c.685G>C, p.G229R) and NRIP1 (c.2705T>G, p.F902C) are classified as variants of uncertain significance (VUS). CHD7 (c.2663T>C, p.M888T) and PROKR2 (c.685G>C, p.G229R) as URA-related genes may be associated with idiopathic hypogonadotropic hypogonadism (IHH) or CHARGE syndrome (CS), and 3D-protein structure prediction revealed that the two variants may affect the stability in the CHD7 protein or PROKR2 protein, separately. The RE-related gene NRIP1 (c.2705T>G, p.F902C) may be causative of congenital anomalies of the kidneys and urinary tract (CAKUT). CONCLUSIONS: Identification of these variants can in exploring the etiology of URA or RE and improve the level of genetic counseling. IMPACTS: We performed trio-whole-exome sequencing (trio- WES) and copy number variation sequencing (CNV- seq) in 10 children, including 9 children with Unilateral Renal Agenesis and 1 with Renal Ectopy after birth. The possible pathogenic genes of URA can be screened using prenatal and postnatal diagnosis of URA fetuses and gene detection after birth. Future studies evaluating this association may lead to a better understanding of URA and elucidate exploring the etiology of URA or RE and improve the level of genetic counseling.
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In this study, a convenient chitosan oligosaccharide laser lithograph (COSLL) technology was developed to fabricate laser-induced graphene (LIG) electrodes and flexible on-chip microsupercapacitors (MSCs). With a simple one-step CO2 laser, the pyrolysis of a chitosan oligosaccharide (COS) and in situ welding of the generated LIGs to engineering plastic substrates are achieved simultaneously. The resulting LIG products display a hierarchical porous architecture, excellent electrical conductivity (6.3 Ω sq-1), and superhydrophilic properties, making them ideal electrode materials for MSCs. The pyrolysis-welding coupled mechanism is deeply discussed through cross-sectional analyses and finite element simulations. The MSCs prepared by COSLL exhibit considerable areal capacitance of over 4 mF cm-2, which is comparable to that of the polyimide-LIG-based counterpart. COSLL is also compatible with complementary metal-oxide-semiconductor (CMOS) and micro-electro-mechanical system (MEMS) processes, enabling the fabrication of LIG/Au MSCs with comparable areal capacitance and lower internal resistance. Furthermore, the as-prepared MSCs demonstrate excellent mechanical robustness, long-cycle capability, and ease of series-parallel integration, benefiting their practical application in various scenarios. With the use of eco-friendly biomass carbon source and convenient process flowchart, the COSLL emerges as an attractive method for the fabrication of flexible LIG on-chip MSCs and various other advanced LIG devices.
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The concomitant cloning of RNA degradation products is a major concern in standard small RNA-sequencing practices. This not only complicates the characterization of bona fide sRNAs but also hampers cross-batch experimental replicability and sometimes even results in library construction failure. Given that all types of plant canonical small RNAs possess the 3' end 2'-O-methylation modification, a new small RNA sequencing (sRNA-seq) method, designated as PBOX-sRNA-seq, has been developed specifically to capture this modification. PBOX-sRNA-seq, as its name implies, relies on the sequential treatment of RNA samples with phenylboronic acid-polyacrylamide gel electrophoresis (PBA-PAGE) and sodium periodate (NaIO4) oxidation, before sRNA library construction and sequencing. PBOX-sRNA-seq outperformed separate treatments (i.e. PBA-PAGE only or NaIO4 only) in terms of the depletion of unmethylated RNA species and capture 2'-O-modified sRNAs with extra-high purity. Using PBOX-sRNA-seq, we discovered that nascent miRNA-5p/-3p duplexes may undergo mono-cytidylation/uridylation before 2'-O-methylation. We also identified two highly conserved types of 5'-tRNA fragments (tRF) bearing HEN1-independent 2'-O modification (mainly the 13-nt tRF-5aAla and the 26-nt tRF-5bGly). We believe that PBOX-sRNA-seq is powerful for both qualitative and quantitative analyses of sRNAs in plants and piRNAs in animals.
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MicroARNs , ARN de Transferencia , MicroARNs/metabolismo , MicroARNs/genética , MicroARNs/química , ARN de Transferencia/metabolismo , ARN de Transferencia/genética , ARN de Transferencia/química , Análisis de Secuencia de ARN/métodos , ARN de Planta/metabolismo , ARN de Planta/química , ARN de Planta/genética , Metilación , Arabidopsis/genética , Arabidopsis/metabolismo , Electroforesis en Gel de Poliacrilamida , Biblioteca de Genes , Ácidos Borónicos/químicaRESUMEN
The predictive power of B-type natriuretic peptide (BNP) and left ventricular ejection fraction (LVEF) is limited by its low specificity in patients with heart failure (HF). Discovery of more novel biomarkers for HF better diagnosis is necessary and urgent. ELABELA, an early endogenous ligand for the G protein-coupled receptor APJ (Apelin peptide jejunum, Apelin receptor), exhibits cardioprotective actions. However, the relationship between plasma ELABELA and cardiac function in HF patients is unclear. To evaluate plasma ELABELA level and its diagnostic value in HF patients, a total of 335 patients with or without HF were recruited for our monocentric observational study. Plasma ELABELA and Apelin levels were detected by immunoassay in all patients. Spearman correlation analysis was used to analyze the correlation between plasma ELABELA or Apelin levels and study variables. The receiver operating characteristic curves were used to access the predictive power of plasma ELABELA or Apelin levels. Plasma ELABELA levels were lower, while plasma Apelin levels were higher in HF patients than in non-HF patients. Plasma ELABELA levels were gradually decreased with increasing New York Heart Association grade or decreasing LVEF. Plasma ELABELA levels were negatively correlated with BNP, left atrial diameter, left ventricular end-diastolic diameter, left ventricular end-systolic diameter, and left ventricular posterior wall thickness and positively correlated with LVEF in HF patients. In contrast, the correlation between plasma Apelin levels and these parameters is utterly opposite to ELABELA. The diagnostic value of ELABELA, Apelin, and LVEF for all HF patients was 0.835, 0.673, and 0.612; the sensitivity was 62.52, 66.20, and 32.97%; and the specificity was 95.92, 67.23, and 87.49%, respectively. All these parameters in HF patients with preserved ejection fraction were comparable to those in total HF patients. Overall, plasma ELABELA levels were significantly reduced and negatively correlated with cardiac function in HF patients. Decreased plasma ELABELA levels may function as a novel screening biomarker for HF. A combined assessment of BNP and ELABELA may be a good choice to increase the accuracy of the diagnosis of HF.
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Apelina , Biomarcadores , Insuficiencia Cardíaca , Hormonas Peptídicas , Humanos , Insuficiencia Cardíaca/sangre , Insuficiencia Cardíaca/diagnóstico , Masculino , Femenino , Hormonas Peptídicas/sangre , Persona de Mediana Edad , Biomarcadores/sangre , Anciano , Apelina/sangre , Volumen Sistólico , Curva ROC , Péptido Natriurético Encefálico/sangre , Función Ventricular Izquierda , Estudios de CohortesRESUMEN
Objective: This study aimed to assess the impact of combined moxibustion therapy and Gua sha on enhancing functional independence, reducing fall risk, and alleviating pain in patients undergoing post-rehabilitation for multiple cerebral infarctions. Methods: In a prospective clinical trial, 67 patients diagnosed with multiple cerebral infarctions (age range: 40 to 93 years) were enrolled. Baseline health characteristics included a median hospital stay of 10 days, prevalent medical conditions such as hypertension (64.18%), and various comorbidities like spondylosis (17.91%) and heart disease (14.93%). Patients received moxibustion treatment daily for 20-30 minutes on specific acupoints of the upper and lower extremities. Additionally, Gua sha therapy targeting the the head, back, chest, abdomen, and selected acupoints was administered twice a week with an interval of 3 to 4 days. Assessments included Barthel Index (BI) for functional independence, Morse Fall Scale (MFS) for fall risk, and Visual Analogue Scale (VAS) for pain intensity before and after the intervention. Results: After one week of rehabilitation, significant improvements were observed in the patient's functional independence, as indicated by a median BI score of 100 (IQR: 95-100), compared to the pre-rehabilitation median score of 95 (IQR: 90-100). The MFS score also showed a significant decrease after rehabilitation, with a median score of 35 (IQR: 35-45) compared to the pre-rehabilitation median score of 45 (IQR: 35-45). Additionally, pain intensity significantly decreased, with a median VAS score of 0 (range: 0-2) after rehabilitation, compared to the pre-rehabilitation median score of 0 (range: 0-3). Conclusion: Combined moxibustion therapy and Gua sha demonstrated positive effects on functional independence, fall risk reduction, and pain alleviation in post-rehabilitation for multiple cerebral infarctions. These findings suggest the potential of moxibustion and Gua sha as complementary interventions in stroke rehabilitation. The observed improvements in functional independence, fall risk, and pain underscore the potential benefits of these therapies for patients with multiple cerebral infarctions. Further exploration could delve into long-term effects, larger-scale trials, and mechanistic studies to elucidate the underlying pathways of efficacy.
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BACKGROUND: Metastasis is still a major cause of poor pathological outcome and prognosis in esophageal squamous cell carcinoma (ESCC) patients. NUAK1 has been reported highly expressed in many human cancers and is associated with the poor prognosis of cancer patients. However, the role of NUAK1 and its underlying signaling mechanism in ESCC metastasis remain unclear. METHODS: Expression of NUAK1 in ESCC was detected by real-time quantitative RT-PCR (qRT-PCR), Western blotting and immunohistochemical staining. MTT, colony formation, wound-healing and transwell assays were used to determine the role NUAK1 in vitro. Metastasis was evaluated by use of an experimental pulmonary metastasis model in BALB/c-nu/nu mice. The mechanisms were assessed by using coimmunoprecipitation, immunofluorescence and dual-luciferase reporter gene experiments. RESULTS: NUAK1 was highly expressed in ESCC tissues compared with the adjacent normal esophageal epithelial tissues. Moreover, the elevated expression of NUAK1 positively correlated with tumor invasion depth, lymph node metastasis, pathological TNM stage, and poor survival in ESCC patients. Further experiments showed that NUAK1 overexpression did not change the cell viability and colony formation of ESCC cells, while remarkably promoted the migration and invasion in vitro and experimental pulmonary metastasis in vivo. Mechanistically, NUAK1 enhanced the transcription level of Slug, which enhanced the migratory and invasive capability of ESCC cells. Consistently, silencing Slug almost completely diminished the migration and invasion of NUAK1-overexpressing ESCC cells. Further studies demonstrated that NUAK1 upregulated the transcription activity of Slug through activating the JNK/c-Jun pathway. CONCLUSION: These results demonstrated that NUAK1 promoted the metastasis of ESCC cells through activating JNK/c-Jun/Slug signaling, indicating NUAK1 is a promising therapeutic target for metastatic ESCC.
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Tiliroside, a natural flavonoid, has various biological activities and improves several inflammatory diseases in rodents. However, the effect of Tiliroside on lipopolysaccharide (LPS)-induced acute kidney injury (AKI) and the underlying mechanisms are still unclear. This study aimed to evaluate the potential renoprotective effect of Tiliroside on LPS-induced AKI in mice. Male C57BL/6 mice were intraperitoneally injected with LPS (a single dose, 3 mg/kg) with or without Tiliroside (50 or 200 mg/kg/day for 8 days). Tiliroside administration protected against LPS-induced AKI, as reflected by ameliorated renal dysfunction and histological alterations. LPS-stimulated renal expression of inflammatory cytokines, fibrosis markers, and kidney injury markers in mice was significantly abolished by Tiliroside. This flavonoid also stimulated autophagy flux but inhibited oxidative stress and tubular cell apoptosis in kidneys from LPS-injected mice. Mechanistically, our study showed the regulation of Tiliroside on the intrarenal renin-angiotensin system in LPS-induced AKI mice. Tiliroside treatment suppressed intrarenal AGT, Renin, ACE, and Ang II, but upregulated intrarenal ACE2 and Ang1-7, without affecting plasma Ang II and Ang1-7 levels. Collectively, our data highlight the renoprotective action of Tiliroside on LPS-induced AKI by suppressing inflammation, oxidative stress, and tubular cell apoptosis and activating autophagy flux via the shift towards the intrarenal ACE2/Ang1-7 axis and away from the intrarenal ACE/Ang II axis.
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Lesión Renal Aguda , Sistema Renina-Angiotensina , Ratones , Masculino , Animales , Lipopolisacáridos/farmacología , Peptidil-Dipeptidasa A/metabolismo , Enzima Convertidora de Angiotensina 2/metabolismo , Ratones Endogámicos C57BL , Riñón/metabolismo , Flavonoides/metabolismo , Lesión Renal Aguda/inducido químicamente , Lesión Renal Aguda/tratamiento farmacológico , Lesión Renal Aguda/prevención & control , Angiotensina II/metabolismoRESUMEN
Drug carriers have been commonly used for drug control release, enhancing drug efficacy and/or minimizing side-effects. However, it is still difficult to get a high loading efficiency when encapsulating super hydrophilic drugs with a narrow therapeutic index, such as many neurotoxins. Increasing the carrier proportion can improve drug loading to a certain degree, while the burst released drug when the formulation enters the body may cause overdose side-effects. Moreover, high-dose carriers themselves may increase the metabolic burden of the body. Hence, new drug carriers and/or loading strategies are urgently needed to promote the applications of these drugs. This minireview will introduce drug loading strategies based on specific interactions (between drugs and carriers) and will discuss the challenges and perspectives of these strategies. This work is expected to provide alternative inspiration for the delivery of hydrophilic drugs.
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Pattern hair loss can occur in both men and women, and the underlying molecular mechanisms have been continuously studied in recent years. Male androgenetic alopecia (M-AGA), also termed male pattern hair loss, is the most common type of hair loss in men. M-AGA is considered an androgen-dependent trait with a background of genetic predisposition. The interplay between genetic and non-genetic factors leads to the phenotype of follicular miniaturization. Although this similar pattern of phenotypic miniaturization can also be found in female pattern hair loss (FPHL), the corresponding genetic factors in M-AGA do not account for the phenotype in FPHL, indicating that there are different genes contributing to FPHL. Therefore, the role of genetic factors in FPHL is still uncertain. Understanding the genetic mechanism that causes FPHL is crucial for the future development of personalized treatment strategies. This review aims to highlight the differences in the ethnic prevalence and genetic background of FPHL, as well as the current genetic research progress in nutrition, Wnt signaling, and sex hormones related to FPHL.
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Alopecia , Andrógenos , Masculino , Femenino , Humanos , Alopecia/genética , Predisposición Genética a la Enfermedad , Fenotipo , Vía de Señalización Wnt/genéticaRESUMEN
The fabrication of flexible pressure sensors with low cost, high scalability, and easy fabrication is an essential driving force in developing flexible electronics, especially for high-performance sensors that require precise surface microstructures. However, optimizing complex fabrication processes and expensive microfabrication methods remains a significant challenge. In this study, we introduce a laser pyrolysis direct writing technology that enables rapid and efficient fabrication of high-performance flexible pressure sensors with a micro-truncated pyramid array. The pressure sensor demonstrates exceptional sensitivities, with the values of 3132.0, 322.5, and 27.8 kPa-1 in the pressure ranges of 0-0.5, 0.5-3.5, and 3.5-10 kPa, respectively. Furthermore, the sensor exhibits rapid response times (loading: 22 ms, unloading: 18 ms) and exceptional reliability, enduring over 3000 pressure loading and unloading cycles. Moreover, the pressure sensor can be easily integrated into a sensor array for spatial pressure distribution detection. The laser pyrolysis direct writing technology introduced in this study presents a highly efficient and promising approach to designing and fabricating high-performance flexible pressure sensors utilizing micro-structured polymer substrates.
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Two-dimensional carbon-based materials have great potential for electrocatalysis. Herein, we screen 12 defective and doped C3N nanosheets by evaluating their CO2RR and NRR activity and selectivity vs. the HER based on density functional theory calculations. The calculation results suggest that all 12 C3Ns can enhance CO2 adsorption and activation. And PN-VC-C3N is the best electrocatalyst for the CO2RR towards HCOOH with UL = -0.17 V, which is much more positive than most of the reported values. BN-C3N and PN-C3N are also good electrocatalysts that promote the CO2RR towards HCOOH (UL = -0.38 V and -0.46 V). Moreover, we find that SiC-C3N can reduce CO2 to CH3OH, adding an alternative option to the limited catalysts available for the CO2RR to CH3OH. Furthermore, BC-VC-C3N, BC-VN-C3N, and SiC-VN-C3N are promising electrocatalysts for the HER with |ΔGH*| ≤ 0.30 eV. However, only three C3Ns of BC-VC-C3N, SiC-VN-C3N, and SiC-VC-C3N can slightly improve N2 adsorption. And none of the 12 C3Ns are found to be suitable for the electrocatalytic NRR because all the ΔeNNH* values are larger than the corresponding ΔGH* values. The high performance of C3Ns in the CO2RR stems from the altered structure and electronic properties, which result from the introduction of vacancies and doping elements into C3N. This work identifies suitable defective and doped C3Ns for excellent performance in the electrocatalytic CO2RR, which will inspire relevant experimental studies to further explore C3Ns for electrocatalysis.
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To meet the comprehensive demand for flexible microwave absorbing (MA) materials, a novel MA rubber containing homemade Polypyrrole nanotube (PPyNT) is produced based on the natural rubber (NR) and acrylonitrile-butadiene rubber (NBR) blends. To achieve the optimal MA performance in the X band, the PPyNT content and NR/NBR blend ratio are adjusted in detail. The 6 phr PPyNT filled NR/NBR (90/10) composite has the superior MA performance with the minimum reflection loss value of -56.67 dB and the corresponding effective bandwidth of 3.7 GHz at a thickness of 2.9 mm, which has the merits in virtue of achieving strong absorption and wide effective absorption band with low filler content and thickness compared to most reported microwave absorbing rubber materials over the same frequency. This work provides new insight into the development of flexible microwave-absorbing materials.
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Short-wave ultraviolet (also called UVC) irradiation is a well-adopted method of viral inactivation due to its ability to damage genetic material. A fundamental problem with the UVC inactivation method is that its mechanism of action on viruses is still unknown at the molecular level. To address this problem, herein we investigate the response mechanism of genome materials to UVC light by means of quantum chemical calculations. The spectral properties of four nucleotides, namely, adenine, cytosine, guanine, and uracil, are mainly focused on. Meanwhile, the transition state and reaction rate constant of uracil molecules are also considered to demonstrate the difficulty level of adjacent nucleotide reaction without and with UVC irradiation. The results show that the peak wavelengths are 248.7 nm, 226.1 nm (252.7 nm), 248.3 nm, and 205.8 nm (249.2 nm) for adenine, cytosine, guanine, and uracil nucleotides, respectively. Besides, the reaction rate constants of uracil molecules are 6.419 × 10-49 s-1 M-1 and 5.436 × 1011 s-1 M-1 for the ground state and excited state, respectively. Their corresponding half-life values are 1.56 × 1048 s and 1.84 × 10-12 s. This directly suggests that the molecular reaction between nucleotides is a photochemical process and the reaction without UVC irradiation almost cannot occur.
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Nucleótidos , Uracilo , Adenina , Citosina , Guanina , Rayos UltravioletaRESUMEN
Copper (Cu) is an essential micronutrient for both human and animals. However, excessive intake of copper will cause damage to organs and cells. Inflammation is a biological response that can be induced by various factors such as pathogens, damaged cells, and toxic compounds. Dysregulation of inflammatory responses are closely related to many chronic diseases. Recently, Cu toxicological and inflammatory effects have been investigated in various animal models and cells. In this review, we summarized the known effect of Cu on inflammatory responses and sum up the molecular mechanism of Cu-regulated inflammation. Excessive Cu exposure can modulate a huge number of cytokines in both directions, increase and/or decrease through a variety of molecular and cellular signaling pathways including nuclear factor kappa-B (NF-κB) pathway, mitogen-activated protein kinase (MAPKs) pathway, JAK-STAT (Janus Kinase- signal transducer and activator of transcription) pathway, and NOD-like receptor protein 3 (NLRP3) inflammasome. Underlying the molecular mechanism of Cu-regulated inflammation could help further understanding copper toxicology and copper-associated diseases.
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Cobre , FN-kappa B , Animales , Humanos , Cobre/toxicidad , FN-kappa B/metabolismo , Inflamación/inducido químicamente , Inflamación/metabolismo , Proteínas Quinasas Activadas por Mitógenos/metabolismo , InflamasomasRESUMEN
Photodecarboxylation of biomass-derived fatty acids to alkanes offers significant potential to obtain hydrocarbons and economic benefits due to the mild conditions and high activity. Herein, the photodecarboxylation of hexanoic acid into alkanes using TiO2-supported monometallic Au or Pd and bimetallic Au-Pd catalysts is reported. It was found that bimetallic Au-Pd catalysts, featuring a core-shell structure evidenced by EDX-mapping and element line profile, show better photocatalytic performance, achieving 94.7% conversion of hexanoic acid and nearly 100% selectivity to pentane under UV-vis irradiation in the absence of H2 than the monometallic Au analogue. This remarkable enhancement in activity compared to its TiO2 supported monometallic Au or Pd analogues can be attributed to the synergistic effect between Au and Pd within the nanostructured Au(core)-Pd(shell) alloy for achieving more efficient charge-separation efficiency upon visible light excitation. This photocatalyst exhibits a wide scope converting multiple fatty acids into hydrocarbons. Moreover, it can even photocatalyze the conversion of raw bio-oils into alkanes directly. No obvious activity loss was observed during the reusability tests, demonstrating the good stability of the present catalyst. Density functional theory (DFT) calculations indicate that oxidation of carboxylates on TiO2 leads to alkyl radicals that become bound to metal nanoparticles. The superior catalytic performance of Au(core)-Pd(shell)/TiO2 is derived from the weaker adsorption for H on the alloy and the lower hydrogen evolution reaction overpotential. Our research can result in an efficient bio-oil upgrading, resulting in the synthesis of biofuels from biomass under mild conditions.
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Recent reports focus on the hydrogenation engineering of monolayer boron phosphide and simultaneously explore its promising applications in nanoelectronics. Coupling density functional theory and finite element method, we investigate the bowtie triangle ring microstructure composed of boron phosphide with hydrogenation based on structural and performance analysis. We determine the carrier mobility of hydrogenated boron phosphide, reveal the effect of structural and material parameters on resonance frequencies, and discuss the variation of the electric field at the two tips. The results suggest that the mobilities of electrons for hydrogenated BP monolayer in the armchair and zigzag directions are 0.51 and 94.4 cm2·V-1·s-1, whereas for holes, the values are 136.8 and 175.15 cm2·V-1·s-1. Meanwhile, the transmission spectra of the bowtie triangle ring microstructure can be controlled by adjusting the length of the bowtie triangle ring microstructure and carrier density of hydrogenated BP. With the increasing length, the transmission spectrum has a red-shift and the electric field at the tips of equilateral triangle rings is significantly weakened. Furthermore, the theoretical sensitivity of the BTR structure reaches 100 GHz/RIU, which is sufficient to determine healthy and COVID-19-infected individuals. Our findings may open up new avenues for promising applications in the rapid diagnosis of COVID-19.
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A novel methodology for the annulation of terminal alkynes and o-phenylenediamines by using a combination of a cobalt catalyst and oxygen as a terminal oxidant is reported. This method shows wide substrate scope and good functional group tolerance and provides a wide range of quinoxalines in good to high yields. The method is demonstrated by its gram-scale and broad potential applications. Furthermore, this protocol serves as a powerful tool for the late-stage functionalization of various complex bioactive molecules and drugs to provide a new class of molecules containing two distinct bioactive molecules directly linked. Detailed mechanistic studies reveal that the current reaction goes through a novel mechanism different from the previously reported glyoxal mechanism.
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Alquinos , Cobalto , Alquinos/química , Cobalto/química , Quinoxalinas/química , Catálisis , Fenilendiaminas/químicaRESUMEN
In Arabidopsis, HESO1 and URT1 act cooperatively on unmethylated miRNA and mRNA uridylation to induce their degradation. Their collaboration significantly impacts RNA metabolism in plants. However, the molecular mechanism determining the functional difference and complementarity of these two enzymes remains unclear. We previously solved the three-dimensional structure of URT1 in the absence and presence of UTP. In this study, we further determined the structure of URT1 in complex with a 5'-AAAU-3' RNA stretch that mimics the post-catalytic state of the mRNA poly(A) tail after the addition of the first uridine. Structural analysis and enzymatic assays revealed that L527 and Y592 endow URT1 with a preference to interact with purine over pyrimidine at the -1 RNA binding position, thus controlling the optimal number of uridine added to the 3' extremity of poly(A) as two. In addition, we observed that a large-scale conformational rearrangement in URT1 occurs upon binding with RNA from an 'open' to a 'closed' state. Molecular dynamic simulation supports an open-closed conformational selection mechanism employed by URT1 to interact with RNA substrates and maintain distributive enzymatic activity. Based on the above results, a model regarding the catalytic cycle of URT1 is proposed to explain its di-uridylation activity.
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Proteínas de Arabidopsis , Arabidopsis , ARN Nucleotidiltransferasas/metabolismo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , MicroARNs/genética , MicroARNs/metabolismo , Purinas/metabolismo , ARN Mensajero/metabolismo , Uridina Trifosfato/metabolismoRESUMEN
Background: Primary hepatic neuroendocrine tumours (PHNET) are extremely rare. Currently, no evidence-based guidelines are available for PHNET treatment, especially for unresectable tumours. Case Presentation: We present the case of a 43-year-old man who was admitted to our hospital with complaints of backache for more than 1 month. The imaging examination showed a 5.5×5.3 cm lesion in the liver and no extrahepatic lesions, which was confirmed as a grade 2 PHNET by the pathological results and exclusion of non-hepatic origins. A multidisciplinary team (MDT) consultation revealed that the lesion was an unresectable primary hepatic neuroendocrine tumour (uPHNET) but could be potentially treated by conversion surgery. The patient was initially administered four cycles of chemotherapy with temozolomide, 5-fluorouracil, and ondansetron, and was evaluated as stable disease (SD) according to the Response Evaluation Criteria in Solid Tumours version 1.1 (RECIST 1.1). Because of the limited clinical benefit of chemotherapy, the patient subsequently underwent transcatheter arterial chemoembolisation (TACE) treatment, which reduced the tumour size and converted uPHNET to resectable tumours. A complete response (CR) was achieved after surgery, and the patient has been disease-free. Conclusions: This case was reported by a patient with uPHNET who benefited from the pre-operative TACE, providing a potentially effective management strategy for refractory tumours.