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1.
J Am Chem Soc ; 146(12): 8320-8326, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38489763

RESUMO

One-dimensional (1D) Heisenberg antiferromagnets are of great interest due to their intriguing quantum phenomena. However, the experimental realization of such systems with large spin S remains challenging because even weak interchain interactions induce long-range ordering. In this study, we present an ideal 1D S = 5/2 spin chain antiferromagnet achieved through a multistep topochemical route involving dehydration and rehydration. By desorbing three water molecules from (2,2'-bpy)FeF3(H2O)·2H2O (2,2'-bpy = 2,2'-bipyridyl) at 150 °C and then intercalating two water molecules at room temperature (giving (2,2'-bpy)FeF3·2H2O 1), the initially isolated FeF3ON2 octahedra combine to form corner-sharing FeF4N2 octahedral chains, which are effectively separated by organic and added water molecules. Mössbauer spectroscopy reveals significant dynamical fluctuations down to 2.7 K, despite the presence of strong intrachain interactions. Moreover, results from electron spin resonance (ESR) and heat capacity measurements indicate the absence of long-range order down to 0.5 K. This controlled topochemical dehydration/rehydration approach is further extended to (2,2'-bpy)CrF3·2H2O with S = 3/2 1D chains, thus opening the possibility of obtaining other low-dimensional spin lattices.

2.
J Transl Med ; 22(1): 809, 2024 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-39217342

RESUMO

BACKGROUND: This study investigates the molecular mechanisms of CC@AC&SF@PP NPs loaded with AC099850.3 siRNA and sorafenib (SF) for improving hepatitis B virus-related hepatocellular carcinoma (HBV-HCC). METHODS: A dataset of 44 HBV-HCC patients and their survival information was selected from the TCGA database. Immune genes related to survival status were identified using the ImmPort database and WGCNA analysis. A prognostic risk model was constructed and analyzed using Lasso regression. Differential analysis was performed to screen key genes, and their significance and predictive accuracy for HBV-HCC were validated using Kaplan-Meier survival curves, ROC analysis, CIBERSORT analysis, and correlation analysis. The correlation between AC099850.3 and the gene expression matrix was calculated, followed by GO and KEGG enrichment analysis using AC099850.3 and its co-expressed genes. HepG2.2.15 cells were selected for in vitro validation, and lentivirus interference, cell cycle determination, CCK-8 experiments, colony formation assays, Transwell experiments, scratch experiments, and flow cytometry were performed to investigate the effects of key genes on HepG2.2.15 cells. A subcutaneous transplanted tumor model in mice was constructed to verify the inhibitory effect of key genes on HBV-HCC tumors. Subsequently, pH-triggered drug release NPs (CC@AC&SF@PP) were prepared, and their therapeutic effects on HBV-HCC in situ tumor mice were studied. RESULTS: A prognostic risk model (AC012313.9, MIR210HG, AC099850.3, AL645933.2, C6orf223, GDF10) was constructed through bioinformatics analysis, showing good sensitivity and specificity in diagnostic prediction. AC099850.3 was identified as a key gene, and enrichment analysis revealed its impact on cell cycle pathways. In vitro cell experiments demonstrated that AC099850.3 promotes HepG2.2.15 cell proliferation and invasion by regulating immune checkpoint CD276 expression and cell cycle progression. In vivo, subcutaneously transplanted tumor experiments showed that AC099850.3 promotes the growth of HBV-HCC tumors in nude mice. Furthermore, pH-triggered drug release NPs (CC@AC&SF@PP) loaded with AC099850.3 siRNA and SF were successfully prepared and delivered to the in situ HBV-HCC, enhancing the effectiveness of combined therapy for HBV-HCC. CONCLUSIONS: AC099850.3 accelerates the cell cycle progression and promotes the occurrence and development of HBV-HCC by upregulating immune checkpoint CD276 expression. CC@AC&SF@PP NPs loaded with AC099850.3 siRNA and SF improve the effectiveness of combined therapy for HBV-HCC.


Assuntos
Antígenos B7 , Carcinoma Hepatocelular , Proliferação de Células , Vírus da Hepatite B , Neoplasias Hepáticas , Invasividade Neoplásica , Sorafenibe , Humanos , Sorafenibe/farmacologia , Sorafenibe/uso terapêutico , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/virologia , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/virologia , Proliferação de Células/efeitos dos fármacos , Animais , Antígenos B7/metabolismo , Antígenos B7/genética , Células Hep G2 , Vírus da Hepatite B/efeitos dos fármacos , Camundongos Nus , Camundongos , Quitosana/química , Quitosana/farmacologia , Inibidores de Checkpoint Imunológico/farmacologia , Inibidores de Checkpoint Imunológico/uso terapêutico , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Masculino , Hepatite B/tratamento farmacológico , Hepatite B/virologia , Camundongos Endogâmicos BALB C
3.
Inorg Chem ; 63(13): 5831-5841, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38506755

RESUMO

The exploration of new rare-earth (RE)-based triangular-lattice materials plays a significant role in motivating the discovery of exotic magnetic states. Herein, we report a family of hexagonal perovskite compounds Ba6RE2Ti4O17 (RE = Nd, Sm, Gd, Dy-Yb) with a space group of P63/mmc, where magnetic RE3+ ions are distributed on the parallel triangular-lattice layers within the ab-plane and stacked in an 'AA'-type fashion along the c-axis. The low-temperature magnetic characterizations indicate that all synthesized Ba6RE2Ti4O17 compounds exhibit dominant antiferromagnetic (AFM) interactions and the absence of magnetic order down to 1.8 K. The isothermal magnetization and electron spin resonance results reveal the distinct magnetic anisotropy for the compounds with different RE ions. Moreover, the as-grown Ba6Nd2Ti4O17 single crystals exhibit Ising-like magnetic anisotropy with a magnetic easy-axis perpendicular to the triangle-lattice plane and no long-range magnetic order down to 80 mK, as the quantum spin liquid candidate with dominant Ising-type interactions.

4.
Inorg Chem ; 63(31): 14354-14365, 2024 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-39056108

RESUMO

A series of analogous chain selenite chlorides Ba2M(SeO3)2Cl2 (M = Cu 1, Ni 2, Co 3, Mn 4) and Pb2Cu(SeO3)2Cl2 5 with tunable spin S from S = 1/2 to S = 5/2 have been hydrothermally synthesized and characterized. These analogues crystallized in the orthorhombic Pnnm space group (monoclinic P21/n space group for 5) all containing M2+-SeO3-M2+ spin chains, which are further separated by the Ba2+ ions (Pb2+ for 5). The magnetic susceptibility results of 1, 2, and 5 show broad maxima around 80.0, 18.9, and 78.0 K, respectively, indicating good one-dimensional (1D) magnetism. Meanwhile, no long-range order (LRO) is observed down to 2 K for both 1 and 5, while the isostructural compounds 2, 3, and 4 exhibit LRO at 3.4 K, 10.8 K, and 5.7 K, respectively, which are further confirmed by the heat capacity and electron spin resonance results, as well as the observed spin-flop transitions in the M-H curves measured at 2 K below TN. The magnetizations of 1-5 at 7 T are still far from saturation. In addition, thermal stability and FT-IR and UV-vis-NIR spectroscopy of 1-5 are reported.

5.
Angew Chem Int Ed Engl ; : e202415700, 2024 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-39248441

RESUMO

One-dimensional (1D) magnets are of great interest owing to their intriguing quantum phenomena and potential application in quantum computing. We successfully synthesized an ideal antiferromagnetic spin S = 5/2 chain compound [H2(4,4'-bpy)](H3O)2Fe2F10 (4,4'-bpy = 4,4'-bipyridyl) 1, using a single-step low-temperature hydrothermal method under conditions that favors the protonation of the bulky bidentate ligand 4,4'-bpy. Compound 1 consists of well-separated (Fe3+-F-)¥ chains with a large Fe-F-Fe angle of 174.8°. Both magnetic susceptibility and specific heat measurements show that 1 does not undergo a magnetic long-range ordering down to 0.5 K, despite the strong Fe-F-Fe intrachain spin exchange J with J/kB = -16.2(1) K. This indicates a negligibly weak interchain spin exchange J'. The J'/J value estimated for 1 is extremely small (< 2.8×10-6), smaller than those reported for all other S = 5/2 chain magnets. Our hydrothermal synthesis incorporates both [H2(4,4'-bpy)]2+ and (H3O)+ cations into the crystal lattice with numerous hydrogen bonds, hence effectively separating the (Fe3+-F-)¥ spin chains. This single-step hydrothermal synthesis under conditions favoring the protonation of bulky bidentate ligands offers an effective synthetic strategy to prepare well-separated 1D spin chain systems of magnetic ions with various spin values.

6.
J Minim Access Surg ; 19(3): 419-426, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37470631

RESUMO

Introduction: The efficacy and safety of minimally invasive pancreatic enucleation (PE) have rarely been investigated. This study aimed to compare the perioperative and long-term outcomes of minimally invasive enucleation (MIEn) with those of open enucleation (OEn) for benign/low-grade malignant pancreatic neoplasms. Patients and Methods: Data collected from patients who underwent PE between January 2011 and June 2020 at our centre were analysed. Results: Forty-two patients who underwent MIEn (10 - robot-assisted and 32 - laparoscopic) and 47 who underwent OEn were included in this study. Compared with the OEn group, the MIEn group showed shorter operation time (147.6 ± 71.3 min vs. 183.1 ± 64.3 min), shorter post-operative hospital stay (11.5 ± 3.9 days vs. 13.4 ± 4.2 days), shorter off-bed activity time (2.9 ± 0.9 days vs. 3.7 ± 1.0 days) and lower estimated blood loss (EBL) (118.5 ± 59.2 mL vs. 153.1 ± 85.0 mL). Overall complication rate (47.6% vs. 55.3%), overall post-operative pancreatic fistula (POPF) rate (40.5% vs. 44.7%) and Grade B + C POPF rate (11.9% vs. 19.1%) were similar in both the groups. For neoplasms located in the proximal pancreas, MIEn showed more favourable perioperative outcomes than OEn. Unlike MIEn for superficial neoplasms, MIEn for neoplasms deeply embedded in the pancreas resulted in a longer operative time and tended to increase EBL and the incidence of complications and POPF. During the follow-up period, no significant differences were observed between these two groups in terms of pancreatic function or quality of life. Conclusions: Compared to OEn, MIEn is effective and safe for patients with benign or low-grade malignant pancreatic neoplasms. However, MIEn for embedded pancreatic neoplasms is recommended only in experienced centres because of the high rates of complications and POPF.

7.
Angew Chem Int Ed Engl ; 62(52): e202314364, 2023 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-37964715

RESUMO

The utilization of a single-atom catalyst to break C-C bonds merges the merits of homogeneous and heterogeneous catalysis and presents an intriguing pathway for obtaining high-value-added products. Herein, a mild, selective, and sustainable oxidative cleavage of alkene to form oxime ether or nitrile was achieved by using atomically dispersed cobalt catalyst and hydroxylamine. Diversified substrate patterns, including symmetrical and unsymmetrical alkenes, di- and tri-substituted alkenes, and late-stage functionalization of complex alkenes were demonstrated. The reaction was successfully scaled up and demonstrated good performance in recycling experiments. The hot filtration test, catalyst poisoning and radical scavenger experiment, time kinetics, and studies on the reaction intermediate collectively pointed to a radical mechanism with cobalt/acid/O2 promoted C-C bond cleavage as the key step.

8.
J Transl Med ; 20(1): 325, 2022 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-35864529

RESUMO

BACKGROUND: NCAPG, non-SMC subunit in the concentrate I complex, might promote the proliferation of hepatocellular carcinoma (HCC), but the mechanism is unclear. The aim of this study was to explore how NCAPG affects PTEN to influence the proliferation of HCC. METHODS: Western blotting, qRT-PCR and immunohistochemistry were used to detect NCAPG expression in HCC tissues. The effect of NCAPG on the proliferation of HCC cell lines was evaluated using an EdU incorporation assay, a Cell Counting Kit-8 assay and Fluorescence in situ hybridization (FISH). BALB/c-nu/nu mice were used for the in vivo proliferation experiment. Transcriptome sequencing was used to determine the relationship between NCAPG and PTEN. Immunocoprecipitation-mass spectrometry (IP-MS), proteomic sequencing and Co-immunoprecipitation (CO-IP) were used to identify and examine the interaction between the NCAPG and CKII proteins. RESULTS: We confirmed that NCAPG was abnormally overexpressed in HCC and promoted the proliferation of HCC cells. Transcriptome sequencing revealed that NCAPG inhibited the transcription of PTEN and promoted the activation of the PI3K-AKT pathway. We found a close association between NCAPG and CKII through proteomic sequencing; their interaction was confirmed by Co-IP. There was a positive correlation between NCAPG and CKII that promoted the phosphorylation of PTEN and thus inhibited its transcription and functions. We also proved that CKII was the key factor in the induction of proliferation by NCAPG. CONCLUSION: We revealed the mechanism by which NCAPG regulates the proliferation of HCC: NCAPG inhibits PTEN through its interaction with CKII, and then activates the PI3K-AKT pathway to promote the proliferation of HCC.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Animais , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Hibridização in Situ Fluorescente , Neoplasias Hepáticas/patologia , Camundongos , Camundongos Endogâmicos BALB C , PTEN Fosfo-Hidrolase/genética , PTEN Fosfo-Hidrolase/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteômica , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/fisiologia
9.
Inorg Chem ; 61(44): 17838-17847, 2022 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-36285503

RESUMO

The iodate anion group has been widely used for design and synthesis of functional materials including nonlinear optical materials but rarely for magnetic materials. Particularly, none of magnetic iodate fluorides has been reported yet. In this work, first, two novel magnetic iodate fluorides MIO3F (M = Co 1 and Ni 2) have been synthesized by a hydrothermal method and characterized by magnetic susceptibility, magnetization, and heat capacity measurements as well as thermogravimetry, Fourier transform infrared spectroscopy (FT-IR), and ultraviolet-visible-near-infrared (UV-vis-NIR) spectroscopy. Compounds 1 and 2 are isostructural and crystallize in the monoclinic space group P21/n with alternating M2+-F2-M2+-O2-M2+ zigzag spin chains along the b axis, which are further separated by triangular IO3 groups in the ab plane. Magnetic susceptibilities suggest that 1 exhibits an antiferromagnetic long-range order (LRO) at 16.5 K, confirmed by heat capacity results with released entropy consistent with the theoretical value for a pseudo-spin of 1/2 for Co2+ at low temperatures. Meanwhile, 2 displays a broad maximum around 10.5 K for low dimensional magnetism followed by a sharp peak at 5.7 K indicating the occurrence of an LRO transition, in good agreement with the heat capacity measurement. Field-dependent magnetizations show an obvious spin-flop transition around 4.5 T and a magnetic hysteresis loop between 4.5 and 7 T for 1, but only a slight slope change could be observed around 2.3 T for 2. Thermal stability, FT-IR, and UV-vis-NIR spectroscopy of 1 and 2 are also reported.

10.
Inorg Chem ; 60(17): 13309-13319, 2021 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-34374524

RESUMO

Two cobalt oxyfluoride antiferromagnets CoMOF5(pyz)(H2O)2 (M = Nb 1, Ta 2; pyz = pyrazine) have been synthesized via conventional hydrothermal methods and characterized by thermogravimetric (TGA) analysis, FTIR spectroscopy, electron spin resonance (ESR), magnetic susceptibility, and magnetization measurements at both static low field and pulsed high field. The single-crystal X-ray diffraction indicates both compounds 1 and 2 are isostructural and crystallize in the monoclinic space group C2/m with a two-dimensional Co2+ triangular lattice in the ab plane, separated by the nonmagnetic MOF5 (M = Nb 1, Ta 2) octahedra along the c-axis with large intertriangular-lattice Co···Co distance. Because of low dimensionality together with frustrated triangular lattice, compounds 1 and 2 exhibit no long-range antiferromagnetic order until ∼3.7 K. Moreover, a spin flop transition is observed in the magnetization curves at 2 K for both compounds, which is further confirmed by ESR spectra. In addition, the ESR spectra suggest the presence of a zero-field spin gap in both compounds. The high field magnetization measured at 2 K saturates at ∼7 T with Ms = 1.55 µB for 1 and 1.71 µB for 2, respectively, after subtracting the Van Vleck paramagnetic contribution, which is usually observed for Co2+ ions with pseudospin spin of 1/2 at low temperature. Powder-averaged magnetic anisotropy of g = 3.10 for 1 (3.42 for 2) and magnetic superexchange interaction J/kB = -3.2 K for 1 (-3.6 K for 2) are obtained.

11.
BMC Surg ; 21(1): 410, 2021 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-34861838

RESUMO

BACKGROUND: Liver tumours between the root angle of the middle and right hepatic veins are a special type of liver segment VIII tumour. In this study, we designed a modified median hepatic fissure approach to remove these tumours. The safety and effectiveness of the approach were evaluated. MATERIALS AND METHODS: From April 2015 to November 2019, 11 patients with liver tumours between the angle of the middle and right hepatic veins underwent this modified median hepatic fissure approach. We retrospectively analysed data from the perioperative periods of these 11 patients, including general condition, operation time, intraoperative bleeding, and postoperative complications. Disease-free survival and overall survival were assessed. RESULTS: Of the 11 patients, 9 patients had primary hepatocellular carcinoma and 2 had colorectal liver metastases. The average intraoperative blood loss was 285 mL (150-450 mL). Two patients developed postoperative bile leakage, but there were no significant serious complications, such as intraabdominal bleeding and liver failure, in any of the patients. The liver function returned to the normal range on the 5th day after surgery. Of the 11 patients, 5 have survived for more than 3 years (45.5%), and 4 have been disease-free for more than 3 years (36.3%). CONCLUSIONS: For liver tumours between the root angle of the middle and right hepatic veins, the modified median hepatic fissure approach is a safe and feasible method.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Perda Sanguínea Cirúrgica , Carcinoma Hepatocelular/cirurgia , Hepatectomia , Veias Hepáticas/cirurgia , Humanos , Neoplasias Hepáticas/cirurgia , Estudos Retrospectivos
12.
Cancer Cell Int ; 20: 31, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32015691

RESUMO

BACKGROUND: Circular RNAs (circRNAs) have received considerable attention in human cancer research. However, many circRNAs remain to be detected. In our study, we determined novel circRNAs and investigated their effects on bladder cancer (BCa). METHODS: Microarray dataset GSE92675 was downloaded from Gene Expression Omnibus (GEO). Then, we combined computational biology with quantitative real-time polymerase chain reaction (qRT-PCR) to select related circRNAs in BCa. The selected circRNA-microRNA (miRNA)-messenger RNA (mRNA) regulatory subnetwork was determined by Gene Oncology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. RESULTS: The regulatory network constructed from the microarray dataset (GSE92675) contained 49 differentially expressed circRNAs (DECs). GO and KEGG analyses showed that the MAPK and PI3K-AKT signaling pathways were statistically significant. On the basis of qRT-PCR and the degree value calculated by the cytoHubba plugin of Cytoscape, hsa_circ_0011385 was finally confirmed. The subnetwork around hsa_circ_0011385 was constructed. In addition, we created a protein-protein interaction (PPI) network composed of 67 nodes and 274 edges after removing independent nodes. GO and KEGG analyses showed that hubgenes were involved in cell cycle activities. Moreover, they could be regulated by miRNAs and play an eventful role in BCa pathogenesis. CONCLUSIONS: We proposed a novel circRNA-miRNA-mRNA network related to BCa pathogenesis. This network might be a new molecular biomarker and could be used to develop potential treatment strategies for BCa.

13.
Mol Cancer ; 18(1): 110, 2019 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-31228940

RESUMO

BACKGROUND: METTL3 is known to be involved in all stages in the life cycle of RNA. It affects the tumor formation by the regulation the m6A modification in the mRNAs of critical oncogenes or tumor suppressors. In bladder cancer, METTL3 could promote the bladder cancer progression via AFF4/NF-κB/MYC signaling network by an m6A dependent manner. Recently, METTL3 was also found to affect the m6A modification in non-coding RNAs including miRNAs, lincRNAs and circRNAs. However, whether this mechanism is related to the proliferation of tumors induced by METTL3 is not reported yet. METHODS: Quantitative real-time PCR, western blot and immunohistochemistry were used to detect the expression of METTL3 in bladder cancer. The survival analysis was adopted to explore the association between METTL3 expression and the prognosis of bladder cancer. Bladder cancer cells were stably transfected with lentivirus and cell proliferation and cell cycle, as well as tumorigenesis in nude mice were performed to assess the effect of METTL3 in bladder cancer. RNA immunoprecipitation (RIP), co-immunoprecipitations and RNA m6A dot blot assays were conducted to confirm that METTL3 interacted with the microprocessor protein DGCR8 and modulated the pri-miR221/222 process in an m6A-dependent manner. Luciferase reporter assay was employed to identify the direct binding sites of miR221/222 with PTEN. Colony formation assay and CCK8 assays were conducted to confirm the function of miR-221/222 in METTL3-induced cell growth in bladder cancer. RESULTS: We confirmed the oncogenic role of METTL3 in bladder cancer by accelerating the maturation of pri-miR221/222, resulting in the reduction of PTEN, which ultimately leads to the proliferation of bladder cancer. Moreover, we found that METTL3 was significantly increased in bladder cancer and correlated with poor prognosis of bladder cancer patients. CONCLUSIONS: Our findings suggested that METTL3 may have an oncogenic role in bladder cancer through interacting with the microprocessor protein DGCR8 and positively modulating the pri-miR221/222 process in an m6A-dependent manner. To our knowledge, this is the first comprehensive study that METTL3 affected the tumor formation by the regulation the m6A modification in non-coding RNAs, which might provide fresh insights into bladder cancer therapy.


Assuntos
Adenosina/análogos & derivados , Metiltransferases/metabolismo , MicroRNAs/genética , Neoplasias da Bexiga Urinária/patologia , Adenosina/metabolismo , Animais , Linhagem Celular Tumoral , Proliferação de Células , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Metiltransferases/genética , Camundongos , Transplante de Neoplasias , PTEN Fosfo-Hidrolase/genética , PTEN Fosfo-Hidrolase/metabolismo , Proteínas de Ligação a RNA/metabolismo , Análise Serial de Tecidos , Regulação para Cima , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/metabolismo
14.
Inorg Chem ; 57(10): 6186-6190, 2018 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-29741890

RESUMO

A layered iron selenite fluoride CsFe3(SeO3)2F6 1 was hydrothermally synthesized. Single-crystal X-ray diffraction studies show that 1 has a trigonal ( P3̅ m1) lattice, where [Fe3(SeO3)2F6]- blocks of three iron sublayers are separated by Cs cations. Within the block, only Fe(2)F6 and Fe(1)O3F3 octahedra are magnetically connected via superexchange Fe(1) -F -Fe(2) pathways, giving an S = 5/2 cube tile (dice) lattice. At low magnetic field, 1 exhibits an antiferromagnetic transition at ∼130 K, where ferrimagnetic cube tile layers are arranged in a staggered manner. At low temperatures, we observed a field-induced transition to a ferrimagnetic state with a one-third magnetization plateau.

15.
Inorg Chem ; 57(22): 14443-14449, 2018 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-30394089

RESUMO

We have identified six new 4d4 and 4d5 compounds with isolated RuCl6 octahedra, with formulas (HMA)4RuCl6·Cl (1; MA = methylamine), (HGly)4RuCl6·Cl (2; gly = glycine), (HGly)3RuCl6·2H2O (3), (NH4)2RuCl6 (4), (HPy)2RuCl6 (5; py = pyridine), and H2(4,4'-bpy)RuCl6 (6; 4,4'-bpy = 4,4'-bipyridine). We find that the temperature-dependent magnetization is well described by single-ion physics in the presence of spin-orbit coupling and negligible superexchange interactions. Further, we find that many compounds in the literature are also well described by single-ion physics, and our results demonstrate the importance of considering single-ion physics when evaluating candidate geometric frustrated magnets in the presence of spin-orbit coupling.

16.
Inorg Chem ; 56(15): 9353-9360, 2017 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-28741934

RESUMO

A diamond spin chain system, one of the one-dimensional frustrated lattices, is known to exhibit novel properties, but experimental studies have been exclusively confined to materials with a single spin component. Here, we report on the synthesis, structure, and magnetic properties of a new diamond chain compound Cu2FePO4F4(H2O)4 1 composed of mixed-spins of Cu2+ (S = 1/2 × 2) and Fe3+ (S = 5/2). Compound 1 crystallizes in the space group C2/c of the monoclinic crystal system with a = 7.7546(4) Å, b = 12.1290(6) Å, c = 9.9209(6) Å, ß = 105.29(1)°, and Z = 4. DC magnetization, Mössbauer spectroscopy, and heat capacity measurements revealed an antiferromagnetic order at 11.3 K with a small ferromagnetic component. It is suggested that ferrimagnetic diamond chains are arranged in an antiferromagnetic fashion (i.e., [...Fe(↑)-2Cu(↓↓)-Fe(↑)...] and [...Fe(↓)-2Cu(↑↑)-Fe(↓)...]) within the ab plane to cancel net magnetization, and the spin orientation of the diamond chains changes alternately along the c axis due to the magnetic anisotropy, leading to a noncollinear spin order. Furthermore, another anomaly is observed in the heat capacity at around 3 K, suggesting a successive magnetic transition or crossover due to competing magnetic interactions.

17.
J Am Chem Soc ; 137(31): 9804-7, 2015 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-26200135

RESUMO

An ideal one-dimensional (1D) magnet is expected to show exotic quantum phenomena. For compounds with larger S (S = 3/2, 2, 5/2, ...), however, a small interchain interaction J' tends to drive a conventional long-range ordered (LRO) state. Here, a new layered structure of FeF3(4,4'-bpy) (4,4'-bpy = 4,4'-bipyridyl) with novel S = 5/2 (Fe(3+)) chains has been hydrothermally synthesized by using 4,4'-bpy to separate chains. The temperature-dependent susceptibility exhibits a broad maximum at high as 164 K, suggesting a fairly strong Fe-F-Fe intrachain interaction J. However, no anomaly associated with a LRO is seen in both magnetic susceptibility and specific heat even down to 2 K. This indicates an extremely small J' with J'/J < 3.2 × 10(-5), making this new material a nearly ideal 1D antiferromagnet. Mössbauer spectroscopy at 2.7 K reveals a critical slowing down of the 1D fluctuations toward a possible LRO at lower temperatures.

18.
Inorg Chem ; 54(3): 765-72, 2015 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-25137441

RESUMO

The syntheses of two noncentrosymmetric (NCS) vanadium oxide-fluoride compounds that originate from the same synthetic reagent concentrations are presented. Hydrothermal and low-temperature syntheses allow the isolation of metastable products that may form new phases (or decompose) upon heating and allow creation of chemically similar but structurally different materials. NCS materials synthesis has been a long-standing goal in inorganic chemistry: in this article, we compare two chemically similar NCS inorganic materials, NaVOF(4)(H(2)O) (I) and NaVO(2-x)F(2+x) (II; x = 1/3). These materials originate from the same, identical reagent mixtures but are synthesized at different temperatures: 100 °C and 150 °C, respectively. Compound I crystallizes in Pna2(1): a = 9.9595(4) Å, b = 9.4423(3) Å, and c = 4.8186(2) Å. Compound II crystallizes in P2(1): a = 6.3742(3) Å, b = 3.5963(2) Å, c = 14.3641(7) Å, and ß = 110.787(3)°. Both materials display second-harmonic-generation activity; however, compound I is type 1 non-phase-matchable, whereas compound II is type 1 phase-matchable.

19.
Inorg Chem ; 53(1): 537-42, 2014 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-24328075

RESUMO

In this study, we describe the crystallization of specific niobium oxide-fluoride anions (either [NbOF4](-) or [NbOF5](2-)) by increasing the fluoride concentration with the appropriate use of organic bases with varied corresponding pKa values to create suitable equilibria for the formation of each anion. HpyNbOF4 (I; py = pyridine) contains the [NbOF4](-) anion, while [H2(4,4'-bpy)]NbOF5] (II; 4,4'-bpy = 4,4'-bipyridyl) contains the [NbOF5](2-) anion; their identity is correlated with reagent ratios. The increase of basic species (proton acceptors) results in an increase in the fluoride concentration and high fluoride-containing anions. The crystallization of [NbOF4](-) in [NbO2/2F4]∞ chains in I was controlled with the use of weak base pyridine (pKa = 5.23), while isolated [NbOF5](2-) crystallized in II with strong base 4,4'-bipyridyl (pKa = 10.5). This approach can be broadly applied to target-specific basic building units for fundamentally new and potentially functional solid-state materials.

20.
Am J Cancer Res ; 14(4): 1523-1544, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38726263

RESUMO

Although sorafenib is the first-line therapeutic agent for advanced hepatocellular carcinoma (HCC), the development of drug resistance in HCC cells limits its clinical efficacy. However, the key factors involved in mediating the sorafenib resistance of HCC cells and the underlying mechanisms have not been elucidated. In this study, we generated sorafenib-resistant HCC cell lines, and our data demonstrate that HLA-F locus-adjacent transcript 10 (FAT10), a ubiquitin-like protein, is markedly upregulated in sorafenib-resistant HCC cells and that reducing the expression of FAT10 in sorafenib-resistant HCC cells increases sensitivity to sorafenib. Mechanistically, FAT10 stabilizes the expression of the PTEN-specific E3 ubiquitin ligase NEDD4 that causes downregulation of PTEN, thereby inducing AKT-mediated autophagy and promoting the resistance of HCC cells to sorafenib. Moreover, we screened the small molecule Compound 7695-0983, which increases the sensitivity of sorafenib-resistant HCC cells to sorafenib by inhibiting the expression of FAT10 to inhibit NEDD4-PTEN/AKT axis-mediated autophagy. Collectively, our preclinical findings identify FAT10 as a key factor in the sorafenib resistance of HCC cells and elucidate its underlying mechanism. This study provides new mechanistic insight for the exploitation of novel sorafenib-based tyrosine kinase inhibitor (TKI)-targeted drugs for treating advanced HCC.

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