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1.
Small ; 19(18): e2207219, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36720005

RESUMO

The electrocatalytic transformation of carbon dioxide (CO2 ) to formate is a promising route for highly efficient conversion and utilization of CO2 gas, due to the low production cost and the ease of storage of formate. In this work, porous poly(ionic liquid) (PPIL)-based tin-silver (Sn-Ag) bimetallic hybrids (PPILm -Snx Ag10- x ) are prepared for high-performance formate electrolytic generation. Under optimal conditions, an excellent formate Faradaic efficiency of 95.5% with a high partial current density of 214.9 mA cm-2 is obtained at -1.03 V (vs reversible hydrogen electrode). Meanwhile, the high selectivity of formate (>≈83%) is maintained in a wide potential range (>630 mV). Mechanistic studies demonstrate that the presence of Ag-species is vital for the formation, maintenance, and high dispersion of tetravalent Sn(IV)-species, which accounts for the active sites for CO2 -to-formate conversion. Further, the introduction of Ag-species significantly enhances the activity by increasing the electron density near the Fermi energy level.

2.
Eur Arch Otorhinolaryngol ; 280(3): 1183-1190, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36053358

RESUMO

OBJECTIVE: To analyze the clinical effect of nitorzumab injection combined with chemoradiotherapy in the treatment of advanced nasopharyngeal carcinoma. METHODS: The databases, such as CNKI, Wanfang, VIP, China Biology Medicine (CBM), PubMed, Cochrane Library, Wiley Online Library, and Google Academic were searched. The randomized controlled trials (RCT) of nimotuzumab combined with concurrent chemoradiotherapy (experimental group) and concurrent chemoradiotherapy (control group) were searched. The between-group differences of objective remission rate (ORR), disease control rate (DCR), and drug-related adverse reactions were analyzed by RevMan5.3 software. RESULTS: Totally, 11 studies were included in meta-analysis, including 655 patients. All 11 articles mentioned random grouping and no blind method was used. The objective remission rate, disease control rate, and adverse drug reactions are given in 11 articles. In this study, 11 literatures were analyzed by fixed effect model after heterogeneity and sensitivity analysis. The meta analysis showed that in 10 literatures, the objective remission rate and disease control rate of patients in the experimental group were significantly higher than those in the control group (RR = 1.32, 95% CI: 1.2-1.45, Z = 5.72, P < 0.00001); (RR = 1.07, 95% CI: 1.02-1.11, Z = 3.04, P = 0.002 < 0.01. There was no significant difference in adverse reactions between the two groups (RR = 0.95, 95% CI: 0.79-1.15, Z = 0.52, P = 0.6 > 0.05). CONCLUSION: The efficacy and safety of nituozumab injection combined with concurrent chemoradiotherapy are reliable and definite.


Assuntos
Anticorpos Monoclonais Humanizados , Neoplasias Nasofaríngeas , Humanos , Carcinoma Nasofaríngeo/tratamento farmacológico , Anticorpos Monoclonais Humanizados/uso terapêutico , Quimiorradioterapia/métodos , Neoplasias Nasofaríngeas/tratamento farmacológico
3.
Int J Mol Sci ; 24(6)2023 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-36983039

RESUMO

Osteoporosis, a common systematic bone homeostasis disorder related disease, still urgently needs innovative treatment methods. Several natural small molecules were found to be effective therapeutics in osteoporosis. In the present study, quercetin was screened out from a library of natural small molecular compounds by a dual luciferase reporter system. Quercetin was found to upregulate Wnt/ß-catenin while inhibiting NF-κB signaling activities, and thereby rescuing osteoporosis-induced tumor necrosis factor alpha (TNFα) impaired BMSCs osteogenesis. Furthermore, a putative functional lncRNA, Malat1, was shown to be a key mediator in quercetin regulated signaling activities and TNFα-impaired BMSCs osteogenesis, as mentioned above. In an ovariectomy (OVX)-induced osteoporosis mouse model, quercetin administration could significantly rescue OVX-induced bone loss and structure deterioration. Serum levels of Malat1 were also obviously rescued in the OVX model after quercetin treatment. In conclusion, our study demonstrated that quercetin could rescue TNFα-impaired BMSCs osteogenesis in vitro and osteoporosis-induced bone loss in vivo, in a Malat1-dependent manner, suggesting that quercetin may serve as a therapeutic candidate for osteoporosis treatment.


Assuntos
Doenças Ósseas Metabólicas , Osteoporose , RNA Longo não Codificante , Camundongos , Animais , Feminino , Humanos , Osteogênese/genética , RNA Longo não Codificante/genética , RNA Longo não Codificante/uso terapêutico , Fator de Necrose Tumoral alfa/farmacologia , Quercetina/farmacologia , Quercetina/uso terapêutico , Medula Óssea/patologia , Osteoporose/etiologia , Osteoporose/genética , Ovariectomia/efeitos adversos , Células-Tronco/patologia , Diferenciação Celular , Via de Sinalização Wnt
4.
Int J Mol Sci ; 24(23)2023 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-38069034

RESUMO

Hepatocellular carcinoma (HCC) is a common malignant tumor with high mortality. Human phenylalanine tRNA synthetase (PheRS) comprises two α catalytic subunits encoded by the FARSA gene and two ß regulatory subunits encoded by the FARSB gene. FARSB is a potential oncogene, but no experimental data show the relationship between FARSB and HCC progression. We found that the high expression of FARSB in liver cancer is closely related to patients' low survival and poor prognosis. In liver cancer cells, the mRNA and protein expression levels of FARSB are increased and promote cell proliferation and migration. Mechanistically, FARSB activates the mTOR complex 1 (mTORC1) signaling pathway by binding to the component Raptor of the mTORC1 complex to play a role in promoting cancer. In addition, we found that FARSB can inhibit erastin-induced ferroptosis by regulating the mTOR signaling pathway, which may be another mechanism by which FARSB promotes HCC progression. In summary, FARSB promotes HCC progression and is associated with the poor prognosis of patients. FARSB is expected to be a biomarker for early screening and treatment of HCC.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/genética , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Proliferação de Células/genética , Linhagem Celular Tumoral
5.
J Am Chem Soc ; 143(2): 612-616, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-33382247

RESUMO

The molecular structure of Sc3N@C2v(7854)-C70 was determined by single-crystal X-ray diffraction. Variable-temperature X-ray diffraction analysis unraveled the details of the phase transition caused by the temperature-driven jumplike rotation of the fullerene cage between two orientations. Whereas in the lower-temperature P21/c phase the fullerene predominantly occupies one orientation, two orientations become equally occupied in the higher-temperature C2/m phase. This work provides a rare example of the well-defined order-disorder transition in metallofullerene crystals and thus gives important insight into the problem of disorder impeding metallofullerene crystallography.

6.
J Am Chem Soc ; 143(43): 18139-18149, 2021 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-34669376

RESUMO

Lanthanide dimetallofullerenes with single-electron M-M bonds are an important class of single molecular magnets and qubit candidates, but stabilization of their unique electronic and spin structure in the form of a neutral molecule requires functionalization of the fullerene cage with a single radical group. The lack of selectivity of the currently available procedure results in a complicated and tedious separation process. Here we demonstrate that electrophilic trifluoromethylation of a mixture of metallofullerene anions with Umemoto reagent II is highly selective toward M2@C80- (M = Tb, Y) anions, yielding M2@C80(CF3) monoadducts as the main reaction product. Single-crystal X-ray diffraction study proved attachment of the CF3 group to the pentagon/hexagon/hexagon junction and revealed that positions of metal atoms inside the fullerene cage in the cocrystal with NiOEP are strongly related to the position of the porphyrin moieties. Magnetic characterization of Tb2@C80(CF3) showed that it is a robust single-molecule magnet with broad magnetic hysteresis, 100 s blocking temperature of 25 K, and the relaxation barrier of 801(4) K, corresponding to the flipping of the Tb magnetic moment in the strongly ferromagnetically coupled [Tb3+-e-Tb3+] spin system.

7.
Biochem Biophys Res Commun ; 546: 65-73, 2021 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-33571906

RESUMO

The occurrence and development of tumors cannot be separated from the influence of differentiation at different stages and levels. Our study found that E-cadherin was significantly increased in cell model induced by sodium butyrate and cell density, while METTL3, METTL16 and WTAP were decreased during the differentiation of cells. In the clinicopathological tissues, E-cadherin was low expressed in poorly differentiated tumor tissues and above three regulators were highly expressed in poorly differentiated tissues. At the levels of clinicopathological differentiation, tissue differentiation and cell differentiation, the result indicated that the poor prognosis of colorectal cancer (CRC) may be closely related to high expression of total m6A level and high expression of METTL3, METTL16 and WTAP.


Assuntos
Adenosina/análogos & derivados , Diferenciação Celular , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Adenosina/metabolismo , Ácido Butírico/farmacologia , Proteínas de Ciclo Celular , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Neoplasias Colorretais/genética , Inibição de Contato/efeitos dos fármacos , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Metiltransferases , Pessoa de Meia-Idade , Biossíntese de Proteínas/efeitos dos fármacos , Fatores de Processamento de RNA , Transcrição Gênica/efeitos dos fármacos
8.
Inorg Chem ; 60(15): 11496-11502, 2021 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-34278797

RESUMO

Actinide endohedral fullerenes have demonstrated remarkably different physicochemical properties compared to their lanthanide analogues. In this work, two novel isomers of Th@C82 were successfully synthesized, isolated, and fully characterized by mass spectrometry, X-ray single crystallography, UV-vis-NIR spectroscopy, Raman spectroscopy, and cyclic voltammetry. The molecular structures of the two isomers were determined unambiguously as Th@C2v(9)-C82 and Th@C2(5)-C82 by single-crystal X-ray diffraction analysis. Raman and UV-vis-NIR spectroscopies further confirm the assignment of the cage isomers. Electrochemical gaps suggest that both Th@C2v(9)-C82 and Th@C2(5)-C82 possess a stable closed-shell electronic structure. The computational results further confirm that Th@C2v(9)-C82 and Th@C2(5)-C82 exhibit a unique four-electron charge transfer from the metal to the carbon cage and are among the most abundant isomers of Th@C82.

9.
Int J Mol Sci ; 22(7)2021 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-33808496

RESUMO

Aptamers are short single-stranded DNA, RNA, or synthetic Xeno nucleic acids (XNA) molecules that can interact with corresponding targets with high affinity. Owing to their unique features, including low cost of production, easy chemical modification, high thermal stability, reproducibility, as well as low levels of immunogenicity and toxicity, aptamers can be used as an alternative to antibodies in diagnostics and therapeutics. Systematic evolution of ligands by exponential enrichment (SELEX), an experimental approach for aptamer screening, allows the selection and identification of in vitro aptamers with high affinity and specificity. However, the SELEX process is time consuming and characterization of the representative aptamer candidates from SELEX is rather laborious. Artificial intelligence (AI) could help to rapidly identify the potential aptamer candidates from a vast number of sequences. This review discusses the advancements of AI pipelines/methods, including structure-based and machine/deep learning-based methods, for predicting the binding ability of aptamers to targets. Structure-based methods are the most used in computer-aided drug design. For this part, we review the secondary and tertiary structure prediction methods for aptamers, molecular docking, as well as molecular dynamic simulation methods for aptamer-target binding. We also performed analysis to compare the accuracy of different secondary and tertiary structure prediction methods for aptamers. On the other hand, advanced machine-/deep-learning models have witnessed successes in predicting the binding abilities between targets and ligands in drug discovery and thus potentially offer a robust and accurate approach to predict the binding between aptamers and targets. The research utilizing machine-/deep-learning techniques for prediction of aptamer-target binding is limited currently. Therefore, perspectives for models, algorithms, and implementation strategies of machine/deep learning-based methods are discussed. This review could facilitate the development and application of high-throughput and less laborious in silico methods in aptamer selection and characterization.


Assuntos
Aptâmeros de Nucleotídeos/farmacologia , Previsões/métodos , Técnica de Seleção de Aptâmeros/métodos , Aptâmeros de Nucleotídeos/química , Aptâmeros de Nucleotídeos/metabolismo , Inteligência Artificial/tendências , Simulação por Computador , Desenho Assistido por Computador/tendências , Ligantes , Simulação de Acoplamento Molecular , Ácidos Nucleicos/química , Reprodutibilidade dos Testes
10.
Antonie Van Leeuwenhoek ; 113(3): 377-388, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31630297

RESUMO

Acne is a common inflammatory skin disease, especially in adolescents. Certain Cutibacterium acnes subtypes are associated with acne, although more than one subtype of C. acnes strains may simultaneously reside on the surface of the skin of an individual. To better understand the relationship between the genomic characteristics of C. acnes subtypes and acnes, we collected 50 C. acnes strains from the facial skin of 10 people (5 healthy individuals, 5 patients with acne) in Liaoning, China and performed whole genome sequencing of all strains. We demonstrated that the six potential pathogenic C. acnes strains were all Type II subtype, and discovered 90 unique genes of the six strains related to acne using pan-genome analysis. The distribution of 2 of the 90 genes was identified by PCR in bacterial cultures collected from the facial skin of 171 individuals (55 healthy individuals, 52 patients with mild acne and 64 patients with moderate to severe acne). Both the genes were significantly associated with acne (Chi square test, P < 0.01). We conclude that Type II strains are associated with acne in Chinese patients.


Assuntos
Acne Vulgar/microbiologia , Infecções por Actinomycetales/microbiologia , Propionibacterium/classificação , China , Genoma Bacteriano , Genômica/métodos , Humanos , Tipagem de Sequências Multilocus , Filogenia , Propionibacterium/genética , Sequenciamento Completo do Genoma
11.
Apoptosis ; 24(3-4): 312-325, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30710195

RESUMO

Gasdermin E (GSDME) has an important role in inducing secondary necrosis/pyroptosis. Upon apoptotic stimulation, it can be cleaved by activated caspase-3 to generate its N-terminal fragment (GSDME-NT), which executes pyroptosis by perforating the plasma membrane. GSDME is expressed in many human lung cancers including A549 cells. Paclitaxel and cisplatin are two representative chemotherapeutic agents for lung cancers, which induce apoptosis via different action mechanisms. However, it remains unclear whether they can induce GSDME-mediated secondary necrosis/pyroptosis in lung A549 cancer cells. Here we showed that both paclitaxel and cisplatin evidently induced apoptosis in A549 cells as revealed by the activation of multiple apoptotic markers. Notably, some of the dying cells displayed characteristic morphology of secondary necrosis/pyroptosis, by blowing large bubbles from the cellular membrane accompanied by caspase-3 activation and GSDME-NT generation. But the ability of cisplatin to induce this phenomenon was much stronger than that of paclitaxel. Consistent with this, cisplatin triggered much higher activation of caspase-3 and generation of GSDME-NT than paclitaxel, suggesting that the levels of secondary necrosis/pyroptosis correlated with the levels of active caspase-3 and GSDME-NT. Supporting this, caspase-3 specific inhibitor (Ac-DEVD-CHO) suppressed cisplatin-induced GSDME-NT generation and concurrently reduced the secondary necrosis/pyroptosis. Besides, GSDME knockdown significantly inhibited cisplatin- but not paclitaxel-induced secondary necrosis/pyroptosis. These results indicated that cisplatin induced higher levels of secondary necrosis/pyroptosis in A549 cells than paclitaxel, suggesting that cisplatin may provide additional advantages in the treatment of lung cancers with high levels of GSDME expression.


Assuntos
Antineoplásicos/farmacologia , Caspase 3/metabolismo , Cisplatino/farmacologia , Neoplasias Pulmonares/tratamento farmacológico , Paclitaxel/farmacologia , Piroptose/efeitos dos fármacos , Receptores de Estrogênio/metabolismo , Células A549 , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Neoplasias Pulmonares/metabolismo , Necrose/tratamento farmacológico , Necrose/metabolismo
12.
Inorg Chem ; 58(24): 16722-16726, 2019 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-31773950

RESUMO

For the first time, Th@Td(19151)-C76, a highly symmetric C76 cage encapsulating an actinide metal ion, has been synthesized and characterized by single-crystal X-ray crystallography, mass spectrometry, UV-vis-NIR spectroscopy, and cyclic voltammetry. The single-crystal crystallographic analysis unambiguously assigned the fullerene cage as Td(19151)-C76 and confirmed Th@Td(19151)-C76 as the first IPR (isolated-pentagon rule) C76-based monometallofullerene. The crystallographic results further revealed that the optimal Th site resides over a sumanene-type hexagon, similar to that of the Th@C1(11)-C86 but different from the previously reported Th@C3v(8)-C82. In addition, electrochemical study found that Th@Td(19151)-C76 processes an unusually low first oxidation potential (0.03 V), suggesting its strong electron donating ability.

13.
Environ Sci Technol ; 53(23): 13570-13582, 2019 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-31657912

RESUMO

Biochar is increasingly gaining attention for its potential environmental benefits. In addition to carbon (C), silicon (Si) is a major elemental component in biochar with abundant precursor sources and remarkable properties. Due to the abundance and utilization of silicon-rich biochar (Sichar), as well as the significant function of Si in agricultural production and environmental remediation, it is indispensable to understand the environmental effects of Si within Sichar. Therefore, this review focused on carbon-silicon coupling in Sichar and summarized the advanced studies on Si within Sichar regarding characterization, soil improvement, pollution remediation, and C-Si coupling interactions. After an understanding of Si content, morphology, species and releasing behaviors, the environmental effects on soil Si balance, the plant uptake of Si, and remediation potentials of inorganic pollutants (Al, As, Cd, and Cr) were summarized. The C-Si coupling interactions were highlighted in the processes of Sichar preparation, pollution remediation, and soil C sequestration. The coupling relationship of C and Si from biomass under natural, pyrolysis and geological processes for the biogeochemical cycling of C and Si can obtain four "F" benefits of farm, food, fuel, and finance. To better understand the environmental effects and maximize the benefits of the designed utilization of Sichar, more investigations are required with an extension to microbes and more interactions with different ions via quantitative modeling.


Assuntos
Carbono , Recuperação e Remediação Ambiental , Carvão Vegetal , Silício , Solo
14.
J Am Chem Soc ; 140(11): 3907-3915, 2018 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-29376388

RESUMO

The nature of actinide-actinide bonds has attracted considerable attention for a long time, especially since recent theoretical studies suggest that triple and up to quintuple bonds should be possible, but little is known experimentally. Actinide-actinide bonds inside fullerene cages have also been proposed, but their existence has been debated intensively by theoreticians. Despite all the theoretical arguments, critical experimental data for a dimetallic actinide endohedral fullerene have never been obtained. Herein, we report the synthesis and isolation of a dimetallic actinide endohedral metallofullerene (EMF), U2@C80. This compound was fully characterized by mass spectrometry, single crystal X-ray crystallography, UV-vis-NIR spectroscopy, Raman spectroscopy, cyclic voltammetry, and X-ray absorption spectroscopy (XAS). The single crystal X-ray crystallographic analysis unambiguously assigned the molecular structure to U2@ I h(7)-C80. In particular, the crystallographic data revealed that the U-U distance is within the range of 3.46-3.79 Å, which is shorter than the 3.9 Å previously predicted for an elongated weak U-U bond inside the C80 cage. The XAS results reveal that the formal charge of the U atoms trapped inside the fullerene cage is +3, which agrees with the computational and crystallographic studies that assign a hexaanionic carbon cage, ( I h-C80)6-. Theoretical studies confirm the presence of a U-U bonding interaction and suggest that the weak U-U bond in U2@ I h(7)-C80 is strengthened upon reduction and weakened upon oxidation. The comprehensive characterization of U2@ I h(7)-C80 and the overall agreement between the experimental data and theoretical investigations provide experimental proof and deeper understanding for actinide metal-metal bonding interactions inside a fullerene cage.

15.
J Am Chem Soc ; 140(51): 18039-18050, 2018 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-30453733

RESUMO

For the first time, actinide endohedral metallofullerenes (EMFs) with non-isolated-pentagon-rule (non-IPR) carbon cages, U@C80, Th@C80, and U@C76, have been successfully synthesized and fully characterized by mass spectrometry, single crystal X-ray diffractometry, UV-vis-NIR and Raman spectroscopy, and cyclic voltammetry. Crystallographic analysis revealed that the U@C80 and Th@C80 share the same non-IPR cage of C1(28324)-C80, and U@C76 was assigned to non-IPR U@ C1(17418)-C76. All of these cages are chiral and have never been reported before. Further structural analyses show that enantiomers of C1(17418)-C76 and C1(28324)-C80 share a significant continuous portion of the cage and are topologically connected by only two C2 insertions. DFT calculations show that the stabilization of these unique non-IPR fullerenes originates from a four-electron transfer, a significant degree of covalency, and the resulting strong host-guest interactions between the actinide ions and the fullerene cages. Moreover, because the actinide ion displays high mobility within the fullerene, both the symmetry of the carbon cage and the possibility of forming chiral fullerenes play important roles to determine the isomer abundances at temperatures of fullerene formation. This study provides what is probably one of the most complete examples in which carbon cage selection occurs through thermodynamic control at high temperatures, so the selected cages do not necessarily coincide with the most stable ones at room temperature. This work also demonstrated that the metal-cage interactions in actinide EMFs show remarkable differences from those previously known for lanthanide EMFs. These unique interactions not only could stabilize new carbon cage structures, but more importantly, they lead to a new family of metallofullerenes for which the cage selection pattern is different to that observed so far for nonactinide EMFs. For this new family, the simple ionic A q+@C2 n q- model makes predictions less reliable, and in general, unambiguously discerning the isolated structures requires the combination of accurate computational and experimental data.

16.
Inorg Chem ; 57(18): 11597-11605, 2018 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-30156833

RESUMO

Mixed-metal cluster fullerenes have been extensively studied in recent years for their rich structural variability of the encaged clusters and have shown great potential in applied studies such as biomedicine and molecular electronic devices. However, the studies in this field have mostly concentrated on the nitride cluster fullerene, and very few other types of mixed-metal cluster fullerenes have been reported so far. Herein, we report the synthesis and isolation of the first mixed-metal oxide cluster fullerene, ScGdO@C82, and a novel mixed dimetallic carbide cluster fullerene, ScGdC2@C82. Spectroscopic and electrochemical studies combined with density functional theory (DFT) calculations assigned the molecular structure of the two cluster fullerenes (CFs) to ScGdO@ C3v(8)-C82 and ScGdC2@ C2v(9)-C82, respectively. DFT calculations also suggested that these two mixed-metal clusters are likely to be found in any of the three isolated pentagon rule Cs(6)-C82, C3v(8)-C82 and/or C2v(9)-C82 cages. The electrochemical studies show that the electrochemical gap of ScGdO@ C3v(8)-C82 and ScGdC2@ C2v(9)-C82 are 1.49 and 1.08 V. Moreover, comparative studies of ScGdO@ C3v(8)-C82 and Sc2O@ C3v(8)-C82, ScGdC2@ C2v(9)-C82 and Sc2C2@ C2v(9)-C82 showed that, despite their close structural resemblance, the replacement of one Sc ion by a Gd ion resulted in notable changes in their electrochemical behaviors as well as their 45Sc NMR spectra.

17.
Org Biomol Chem ; 16(11): 1971-1975, 2018 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-29498392

RESUMO

A metal-free protocol of direct C(sp3)-H cyanation with cyanobenziodoxolones functioning as both cyanating reagents and oxidants was developed. Unactivated substrates, such as alkanes, ethers and tertiary amines, were thereby transformed to the corresponding nitriles in moderate to high yields. Mechanistic studies indicated that the cyanation proceeded with two potential pathways, which is highly dependent on the substrates: (1) a free radical case for alkanes and ethers and (2) an oxidative case for tertiary amines.

18.
Nucleic Acids Res ; 44(9): e85, 2016 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-26850641

RESUMO

CRISPR/Cas9-induced site-specific DNA double-strand breaks (DSBs) can be repaired by homology-directed repair (HDR) or non-homologous end joining (NHEJ) pathways. Extensive efforts have been made to knock-in exogenous DNA to a selected genomic locus in human cells; which, however, has focused on HDR-based strategies and was proven inefficient. Here, we report that NHEJ pathway mediates efficient rejoining of genome and plasmids following CRISPR/Cas9-induced DNA DSBs, and promotes high-efficiency DNA integration in various human cell types. With this homology-independent knock-in strategy, integration of a 4.6 kb promoterless ires-eGFP fragment into the GAPDH locus yielded up to 20% GFP+ cells in somatic LO2 cells, and 1.70% GFP+ cells in human embryonic stem cells (ESCs). Quantitative comparison further demonstrated that the NHEJ-based knock-in is more efficient than HDR-mediated gene targeting in all human cell types examined. These data support that CRISPR/Cas9-induced NHEJ provides a valuable new path for efficient genome editing in human ESCs and somatic cells.


Assuntos
Sistemas CRISPR-Cas/genética , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , Reparo do DNA por Junção de Extremidades/genética , Genes Reporter/genética , Gliceraldeído-3-Fosfato Desidrogenase (Fosforiladora)/genética , Reparo de DNA por Recombinação/genética , Linhagem Celular Tumoral , DNA/genética , Quebras de DNA de Cadeia Dupla , Edição de Genes/métodos , Técnicas de Introdução de Genes , Proteínas de Fluorescência Verde/genética , Células HCT116 , Células HEK293 , Células-Tronco Embrionárias Humanas/citologia , Humanos , RNA Guia de Cinetoplastídeos/genética
19.
J Am Chem Soc ; 139(14): 5110-5116, 2017 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-28314102

RESUMO

Endohedral metallofullerenes (EMFs) containing lanthanides have been intensively studied in recent years. By contrast, actinide endohedral fullerenes remain largely unexplored. Herein, for the first time, we report the single crystal structure and full characterization of an actinide endohedral fullerene, Th@C82, which exhibits remarkably different electronic and spectroscopic properties compared to those of lanthanide EMFs. Single crystal X-ray crystallography unambiguously established the molecular structure as Th@C3v(8)-C82. Combined experimental and theoretical studies reveal that Th@C3v(8)-C82 is the first example of an isolated monometallofullerene with four electrons transferred from the metal to the cage, with a surprisingly large electrochemical band gap of 1.51 eV. Moreover, Th@C3v(8)-C82 displays a strong vibrationally coupled photoluminescence signal in the visible region, an extremely rare feature for both fullerenes and thorium compounds.

20.
Chemistry ; 23(8): 1775-1778, 2017 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-27917550

RESUMO

A highly effective asymmetric version of α-cyanation of ß-keto esters and amides was developed with a Lewis-acid catalyst. Thus, by using 10 mol % of a tridentate bisoxazoline-zinc(II) complex as the catalyst, a series of chiral nitriles containing a quaternary carbon center were obtained in excellent enantioselectivities (up to 97 % enantiomeric excess) and up to 95 % yield in the presence of 4 Šmolar sieve at room temperature. For the first time, mild and active 4-acetylphenyl cyanate was used instead of cyano-hyperiodinate as the cationic cyano source for catalytic asymmetric α-cyanation.

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