Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 522
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
J Am Chem Soc ; 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38869355

RESUMO

Coupling two magnetic anisotropic lanthanide ions via a direct covalent bond is an effective way to realize high magnetization blocking temperature of single-molecule magnets (SMMs) by suppressing quantum tunneling of magnetization (QTM), whereas so far only single-electron lanthanide-lanthanide bonds with relatively large bond distances are stabilized in which coupling between lanthanide and the single electron dominates over weak direct 4f-4f coupling. Herein, we report for the first time synthesis of short Dy(II)-Dy(II) single bond (3.61 Å) confined inside a carbon cage in the form of an endohedral metallofullerene Dy2@C82. Such a direct Dy(II)-Dy(II) covalent bond renders a strong Dy-Dy antiferromagnetic coupling that effectively quenches QTM at zero magnetic field, thus opening up magnetic hysteresis up to 25 K using a field sweep rate of 25 Oe/s, concomitant with a high 100 s magnetization blocking temperature (TB,100s) of 27.2 K.

2.
Artigo em Inglês | MEDLINE | ID: mdl-38771147

RESUMO

Alteration in the normal mechanical forces of breathing can contribute to changes in contractility and remodeling characteristic of airway diseases, but the mechanisms that mediate these effects in airway cells are still under investigation. Airway smooth muscle (ASM) cells contribute to both contractility and extracellular matrix (ECM) remodeling. In this study, we explored ASM mechanisms activated by mechanical stretch, focusing on mechanosensitive piezo channels and the key Ca2+ regulatory protein stromal interaction molecule 1 (STIM1). Expression of Ca2+ regulatory proteins, including STIM1, Orai1 and caveolin-1, mechanosensitive ion channels Piezo-1 and Piezo-2, and NLRP3 inflammasomes were upregulated by 10% static stretch superimposed on 5% cyclic stretch. These effects were blunted by STIM1 siRNA. Histamine-induced [Ca2+]i responses and inflammasome activation were similarly blunted by STIM1 knockdown. These data show that the effects of mechanical stretch in human ASM cells are mediated through STIM1, which activates multiple pathways including Piezo channels and the inflammasome, leading to potential downstream changes in contractility and ECM remodeling.

3.
Biochem Biophys Res Commun ; 695: 149425, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38211533

RESUMO

OBJECTIVES: Head and neck tumor patients may develop post-radiotherapy diseases after radiotherapy treatment. And radiotherapy can elicit radiation-induced bystander effect, wherein extracellular vesicles (EVs) play a crucial role. For normal parts of the body that have not been directly irradiated, the effect of EVs on them needs to be further explored. This study aims to investigate the functions of plasma-derived EVs in regulating normal osteoblasts during radiation-induced bystander effects. METHODS AND MATERIALS: Rat plasma-derived EVs were isolated and identified firstly, followed by an evaluation of their intracellular biological effects on normal osteoblasts in vitro. Transcriptome sequencing analysis and confirmations were performed to identify potential mechanisms. RESULTS: Irradiated plasma-derived EVs were found to enhance osteoblast proliferation, migration, and cell cycle progression, concurrently suppressing the expression of osteogenesis-related genes and proteins. Furthermore, these EVs attenuated the expression of osteogenesis and oxidative stress resistance related genes, while upregulating the PI3K-AKT pathway and intracellular reactive oxygen species in osteoblasts. CONCLUSIONS: Irradiated plasma-derived EVs could alter the biological effects in osteoblasts, which is closely associated with the levels of GPX1 and the PI3K-AKT signaling pathway. This suggests that plasma-derived EVs serve as a crucial factor contributing to radiation-induced bystander effect in osteoblasts.


Assuntos
Efeito Espectador , Vesículas Extracelulares , Humanos , Ratos , Animais , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Osteoblastos/metabolismo , Vesículas Extracelulares/metabolismo
4.
Cancer Immunol Immunother ; 73(8): 159, 2024 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-38850359

RESUMO

BACKGROUND: Although, immune checkpoint inhibitors (ICIs) have been widely applied in the therapy of malignant tumors, the efficacy and safety of ICIs in patients with tumors and pre-existing CAD, especially chronic coronary syndromes (CCS) or their risk factors (CRF), is not well identified. METHODS: This was a nationwide multicenter observational study that enrolled participants who diagnosed with solid tumors and received ICIs therapy. The main efficacy indicators were progression-free survival (PFS) and overall survival (OS), followed by objective response rate (ORR) and disease control rate (DCR). Safety was assessed by describing treatment-related adverse events (TRAEs) during ICIs therapy evaluated by the Common Terminology Criteria for Adverse Events 5.0 (CTCAE 5.0). RESULTS: In the current research, we retrospectively analyzed the data of 551 patients diagnosed with solid tumors and received ICIs therapy, and these patients were divided into CCS/CRF group and non-CCS/CRF group. Patients with CCS/CRF had more favorable PFS and OS than patients without CCS/CRF (P < 0.001) and the pre-existing CCS/CRF was a protective factor for survival. The ORR (51.8% vs. 39.1%) and DCR (95.8% vs. 89.2%) were higher in CCS/CRF group than in non-CCS/CRF group (P = 0.003, P = 0.006). In this study, there was no significant difference in treatment-related adverse events (TRAEs), including immune-related adverse events (irAEs), between the two groups. CONCLUSIONS: We concluded that ICIs appear to have better efficacy in malignant solid tumor patients with pre-existing CCS/CRF and are not accompanied by more serious irAEs.


Assuntos
Inibidores de Checkpoint Imunológico , Neoplasias , Humanos , Inibidores de Checkpoint Imunológico/efeitos adversos , Inibidores de Checkpoint Imunológico/uso terapêutico , Feminino , Masculino , Neoplasias/tratamento farmacológico , Neoplasias/complicações , Neoplasias/imunologia , Pessoa de Meia-Idade , Estudos Retrospectivos , Idoso , Fatores de Risco , Adulto , Idoso de 80 Anos ou mais , Estudos de Coortes
5.
Plant Physiol ; 191(3): 1771-1788, 2023 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-36617241

RESUMO

A key function of SUMOylation is the coordinated modification of numerous proteins to optimize plant growth and resistance to environmental stress. Plant cuticular wax is deposited on the surface of primary plant organs to form a barrier that provides protection against changes in terrestrial environments. Many recent studies have examined cuticular wax biosynthetic pathways and regulation. However, whether SUMOylation is involved in the regulation of cuticle wax deposition at the posttranslational level remains unclear. Here, we demonstrate that a small ubiquitin-like modifier (SUMO) E3 ligase, SAP AND MIZ1 DOMAIN CONTAINING LIGASE1 (MdSIZ1), regulates wax accumulation and cuticle permeability in apple (Malus domestica Borkh), SUMO E2 CONJUGATING ENZYME 1(MdSCE1) physically interacts with MdMYB30, a transcription factor involved in the regulation of cuticle wax accumulation. MdSIZ1 mediates the SUMOylation and accumulation of MdMYB30 by inhibiting its degradation through the 26S proteasome pathway. Furthermore, MdMYB30 directly binds to the ß-KETOACYL-COA SYNTHASE 1 (MdKCS1) promoter to activate its expression and promote wax biosynthesis. These findings indicate that the MdSIZ1-MdMYB30-MdKCS1 module positively regulates cuticular wax biosynthesis in apples. Overall, the findings of our study provide insights into the regulation pathways involved in cuticular wax biosynthesis.


Assuntos
Malus , Malus/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina/metabolismo , Regulação da Expressão Gênica de Plantas , Ceras/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
6.
Circ Res ; 130(9): 1321-1341, 2022 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-35382554

RESUMO

BACKGROUND: Cerebral small vessel injury, including loss of endothelial tight junctions, endothelial dysfunction, and blood-brain barrier breakdown, is an early and typical pathology for Alzheimer's disease, cerebral amyloid angiopathy, and hypertension-related cerebral small vessel disease. Whether there is a common mechanism contributing to these cerebrovascular alterations remains unclear. Studies have shown an elevation of BACE1 (ß-site amyloid precursor protein cleaving enzyme 1) in cerebral vessels from cerebral amyloid angiopathy or Alzheimer's disease patients, suggesting that vascular BACE1 may involve in cerebral small vessel injury. METHODS: To understand the contribution of vascular BACE1 to cerebrovascular impairments, we combined cellular and molecular techniques, mass spectrometry, immunostaining approaches, and functional testing to elucidate the potential pathological mechanisms. RESULTS: We observe a 3.71-fold increase in BACE1 expression in the cerebral microvessels from patients with hypertension. Importantly, we discover that an endothelial tight junction protein, occludin, is a completely new substrate for endothelial BACE1. BACE1 cleaves occludin with full-length occludin reductions and occludin fragment productions. An excessive cleavage by elevated BACE1 induces membranal accumulation of caveolin-1 and subsequent caveolin-1-mediated endocytosis, resulting in lysosomal degradation of other tight junction proteins. Meanwhile, membranal caveolin-1 increases the binding to eNOS (endothelial nitric oxide synthase), together with raised circulating Aß (ß-amyloid peptides) produced by elevated BACE1, leading to an attenuation of eNOS activity and resultant endothelial dysfunction. Furthermore, the initial endothelial damage provokes chronic reduction of cerebral blood flow, blood-brain barrier leakage, microbleeds, tau hyperphosphorylation, synaptic loss, and cognitive impairment in endothelial-specific BACE1 transgenic mice. Conversely, inhibition of aberrant BACE1 activity ameliorates tight junction loss, endothelial dysfunction, and memory deficits. CONCLUSIONS: Our findings establish a novel and direct relationship between endothelial BACE1 and cerebral small vessel damage, indicating that abnormal elevation of endothelial BACE1 is a new mechanism for cerebral small vessel disease pathogenesis.


Assuntos
Doença de Alzheimer , Angiopatia Amiloide Cerebral , Doenças de Pequenos Vasos Cerebrais , Hipertensão , Doença de Alzheimer/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide , Animais , Ácido Aspártico Endopeptidases/genética , Ácido Aspártico Endopeptidases/metabolismo , Caveolina 1/genética , Caveolina 1/metabolismo , Angiopatia Amiloide Cerebral/complicações , Angiopatia Amiloide Cerebral/metabolismo , Humanos , Hipertensão/complicações , Camundongos , Camundongos Transgênicos , Óxido Nítrico Sintase Tipo III/metabolismo , Ocludina/metabolismo , Proteínas de Junções Íntimas , Junções Íntimas/metabolismo
7.
Faraday Discuss ; 249(0): 469-484, 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-37786338

RESUMO

This study investigates the influence of excess water on the lipidic mesophase during the phase transition from diamond cubic phase (Pn3̄m) to reverse hexagonal phase (HII). Using a combination of small angle X-ray scattering (SAXS), broadband dielectric spectroscopy (BDS), and Fourier transform infrared (FTIR) techniques, we explore the dynamics of lipids and their interaction with water during phase transition. Our BDS results reveal three relaxation processes originating from lipids, all of which exhibit a kink during the phase transition. With the excess water, these processes accelerate due to the plasticizing effect of water. Additionally, our results demonstrate that the headgroups in the HII phase are more densely packed than those in the Pn3̄m phase, which agrees with the FTIR results. Meanwhile, we investigate the influence of excess water on the lipid headgroups, the H-bond network of water, the lipid tail, and the interface carbonyl group between the head and tail of the lipid molecule. The results indicate that excess water permeates the lipid interface and forms additional hydrogen bonds with the carbonyl groups. As a result, the headgroups are more flexible in a lipidic mesophase with excess water than those in mesophases without excess water.

8.
Inorg Chem ; 63(21): 10022-10030, 2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38748907

RESUMO

In this work, phase-pure Mg1.8(Ni1-xCox)0.2Al4Si5O18 (0 ≤ x ≤ 1) ceramics were synthesized by a high-temperature solid-state method. On the basis of Rietveld refinement data of X-ray powder diffraction and Phillips-Vechten-Levine theory, the atomic ionicity, lattice energy, and bond energy of the compound were calculated to explore their influence on the microwave dielectric properties of ceramics. The Mg1.8Ni0.1Co0.1Al4Si5O18 (x = 0.5) ceramic exhibited the best microwave dielectric properties: εr = 4.44, Qf = 73 539 GHz@13 GHz, and τf = -23.9 ppm/°C. (Ni1-xCox)2+ complex ionic doping, compared with only Ni2+ or Co2+, is beneficial for improving the symmetry of [Si4Al2O18] hexagonal rings and reducing distortion. Subsequently, 8 wt % TiO2 was added to Mg1.8Ni0.1Co0.1Al4Si5O18, resulting in a near-zero τf and high Qf values for the composite ceramic, with εr = 5.22, Qf = 58 449 GHz@13 GHz, and τf = -2.06 ppm/°C. Finally, a 5G millimeter-wave antenna with a central operating frequency of 25.52 GHz was designed and fabricated using the Mg1.8Ni0.1Co0.1Al4Si5O18-8 wt % TiO2 ceramics. Operating in the 24.7-26.0 GHz range, it demonstrated favorable radiation characteristics with a simulated efficiency of 85.2% and a gain of 4.58 dBi. The antenna's performance confirms the high potential of the cordierite composite for application in 5G communication systems.

9.
Proc Natl Acad Sci U S A ; 118(47)2021 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-34782465

RESUMO

Ischemic stroke can induce neurogenesis. However, most stroke-generated newborn neurons cannot survive. It has been shown that MR-409, a potent synthetic agonistic analog of growth hormone-releasing hormone (GHRH), can protect against some life-threatening pathological conditions by promoting cell proliferation and survival. The present study shows that long-term treatment with MR-409 (5 or 10 µg/mouse/d) by subcutaneous (s.c.) injection significantly reduces the mortality, ischemic insult, and hippocampal atrophy, and improves neurological functional recovery in mice operated on for transient middle cerebral artery occlusion (tMCAO). Besides, MR-409 can stimulate endogenous neurogenesis and improve the tMCAO-induced loss of neuroplasticity. MR-409 also enhances the proliferation and inhibits apoptosis of neural stem cells treated with oxygen and glucose deprivation-reperfusion. The neuroprotective effects of MR-409 are closely related to the activation of AKT/CREB and BDNF/TrkB pathways. In conclusion, the present study demonstrates that GHRH agonist MR-409 has remarkable neuroprotective effects through enhancing endogenous neurogenesis in cerebral ischemic mice.


Assuntos
Hormônio Liberador de Hormônio do Crescimento/agonistas , Hormônio Liberador de Hormônio do Crescimento/metabolismo , AVC Isquêmico/metabolismo , Regeneração Nervosa/efeitos dos fármacos , Neurogênese/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Proliferação de Células/efeitos dos fármacos , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Hormônio Liberador de Hormônio do Crescimento/genética , Infarto da Artéria Cerebral Média/metabolismo , Masculino , Glicoproteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Células-Tronco Neurais/metabolismo , Plasticidade Neuronal , Fármacos Neuroprotetores , Proteínas Tirosina Quinases/metabolismo , Recuperação de Função Fisiológica/efeitos dos fármacos
10.
BMC Biol ; 21(1): 176, 2023 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-37592232

RESUMO

BACKGROUND: Lotus corniculatus is a widely distributed perennial legume whose great adaptability to different environments and resistance to barrenness make it an excellent forage and ecological restoration plant. However, its molecular genetics and genomic relationships among populations are yet to be uncovered. RESULT: Here we report on a genomic variation map from worldwide 272 L. corniculatus accessions by genome resequencing. Our analysis suggests that L. corniculatus accessions have high genetic diversity and could be further divided into three subgroups, with the genetic diversity centers were located in Transcaucasia. Several candidate genes and SNP site associated with CNglcs content and growth traits were identified by genome-wide associated study (GWAS). A non-synonymous in LjMTR was responsible for the decreased expression of CNglcs synthesis genes and LjZCD was verified to positively regulate CNglcs synthesis gene CYP79D3. The LjZCB and an SNP in LjZCA promoter were confirmed to be involved in plant growth. CONCLUSION: This study provided a large number of genomic resources and described genetic relationship and population structure among different accessions. Moreover, we attempt to provide insights into the molecular studies and breeding of CNglcs and growth traits in L. corniculatus.


Assuntos
Lotus , Lotus/genética , Melhoramento Vegetal , Loci Gênicos , Demografia
11.
Angew Chem Int Ed Engl ; 63(1): e202312880, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-37962302

RESUMO

Soft nanoconfinement can increase chemical reactivity in nature and has therefore led to considerable interest in transferring this universal feature to artificial biological systems. However, little is known about the underlying principles of soft nanoconfinement responsible for the enhancement of biochemical reactions. Herein we demonstrate how enzymatic polymerization can be expanded, optimized, and engineered when carried out under soft nanoconfinement mediated by lipidic mesophases. By systematically varying the water content in the mesophase and thus the diameter of the confined water nanochannels, we show higher efficiency, turnover rate, and degrees of polymerization as compared to the bulk aqueous solution, all controlled by soft nanoconfinement effects. Furthermore, we exploit the unique properties of unfreezing soft nanoconfined water to perform the first enzymatic polymerization at -20 °C in pure aqueous media. These results underpin lipidic mesophases as a versatile host system for chemical reactions and promote them as an original and unexplored platform for enzymatic polymerization.


Assuntos
Lipídeos , Água , Polimerização , Água/química , Lipídeos/química
12.
J Am Chem Soc ; 145(10): 5645-5654, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36800216

RESUMO

The chemistry of f-block metal-carbon multiple bonds is underdeveloped compared to well-established carbene complexes of the d-block transition metals. Herein, we report two new actinide-rare earth mixed metal carbides and nitrogen carbide cluster fullerenes, USc2C2@D5h(6)-C80 and USc2NC@D5h(6)-C80, which contain U-C bonds with triple bond character and were successfully synthesized and characterized by mass spectrometry, UV-vis-NIR spectroscopy, Fourier transform infrared spectroscopy, single crystal X-ray diffraction, and DFT calculations. Crystallographic studies show that the two previously unreported clusters, USc2C2 and USc2NC, are stabilized in the D5h(6)-C80 carbon cage and adopt unique trifoliate configurations, in which C2/NC units are almost vertically inserted into the plane defined by the U and two Sc atoms. Combined experimental and theoretical studies further reveal the bonding structure of USc2C2 and USc2NC, which contain C═U(VI)═C and C═U(V)═N bonding motifs. The electronic structures of the two compounds are determined as U6+(Sc2)6+(C4-)2@D5h(6)-C804- and U5+(Sc2)6+(N)3-(C)4-@D5h(6)-C804-, respectively. Quantum-chemical studies confirm that the U-C bonds in both molecules show unprecedented multicenter triple-bond character. The discovery of this unique U-C multiple bond offers a deeper understanding of the fundamentals of uranium chemistry.

13.
J Am Chem Soc ; 145(41): 22599-22608, 2023 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-37787921

RESUMO

Metal complexes bearing single-electron metal-metal bonds (SEMBs) exhibit unusual electronic structures evoking strong magnetic coupling, and such bonds can be stabilized in the form of dimetallofullerenes (di-EMFs) in which two metals are confined in a carbon cage. Up to now, only a few di-EMFs containing SEMBs are reported, which are all based on a high-symmetry icosahedral (Ih) C80 cage embedding homonuclear rare-earth bimetals, and a chemical modification of the Ih-C80 cage is required to stabilize the SEMB. Herein, by introducing 3d-block transition metal titanium (Ti) along with 4f-block lanthanum (La) into the carbon cage, we synthesized the first crystallographically characterized SEMB-containing 3d-4f heteronuclear di-EMFs based on pristine fullerene cages. Four novel La-Ti heteronuclear di-EMFs were isolated, namely, LaTi@D3h(5)-C78, LaTi@Ih(7)-C80, LaTi@D5h(6)-C80, and LaTi@C2v(9)-C82, and their molecular structures were unambiguously determined by single-crystal X-ray diffraction. Upon increasing the cage size from C78 to C82, the La-Ti distance decreases from 4.31 to 3.97 Å, affording fine-tuning of the metal-metal bonding and hyperfine coupling, as evidenced by an electron spin resonance (ESR) spectroscopic study. Density functional theory (DFT) calculations confirm the existence of SEMB in all four LaTi@C2n di-EMFs, and the accumulation of electron density between La and Ti atoms shifts gradually from the proximity of the Ti atom inside C78 to the center of the LaTi bimetal inside C82 due to the decrease of the La-Ti distance. The electronic properties of LaTi@C2n heteronuclear dimetallofullerenes differ apparently from their homonuclear La2@C2n counterparts, revealing the peculiarity of heteronuclear dimetallofullerenes with the involvement of 3d-block transition metal Ti.

14.
J Am Chem Soc ; 145(46): 25440-25449, 2023 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-37955678

RESUMO

Despite decades of efforts, the actinide-carbon triple bond has remained an elusive target, defying synthesis in any isolable compound. Herein, we report the successful synthesis of uranium-carbon triple bonds in carbide-bridged bimetallic [U≡C-Ce] units encapsulated inside the fullerene cages of C72 and C78. The molecular structures of UCCe@C2n and the nature of the U≡C triple bond were characterized through X-ray crystallography and various spectroscopic analyses, revealing very short uranium-carbon bonds of 1.921(6) and 1.930(6) Å, with the metals existing in their highest oxidation states of +6 and +4 for uranium and cerium, respectively. Quantum-chemical studies further demonstrate that the C2n cages are crucial for stabilizing the [UVI≡C-CeIV] units through covalent and coordinative interactions. This work offers a new fundamental understanding of the elusive uranium-carbon triple bond and informs the design of complexes with similar bonding motifs, opening up new possibilities for creating distinctive molecular compounds and materials.

15.
J Am Chem Soc ; 145(30): 16778-16786, 2023 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-37406618

RESUMO

Endohedral metallofullerenes (EMFs) are sub-nano carbon materials with diverse applications, yet their formation mechanism, particularly for metastable isomers, remains ambiguous. The current theoretical methods focus mainly on the most stable isomers, leading to limited predictability of metastable ones due to their low stabilities and yields. Herein, we report the successful isolation and characterization of two metastable EMFs, Sc2C2@C1(39656)-C82 and Sc2C2@C1(51383)-C84, which violate the isolated pentagon rule (IPR). These two non-IPR EMFs exhibit a rare case of planar and pennant-like Sc2C2 clusters, which can be considered hybrids of the common butterfly-shaped and linear configurations. More importantly, the theoretical results reveal that despite being metastable, these two non-IPR EMFs survived as the products from their most stable precursors, Sc2C2@C2v(5)-C80 and Sc2C2@Cs(6)-C82, via a C2 insertion during the post-formation annealing stages. We propose a systematic theoretical method for predicting metastable EMFs during the post-formation stages. The unambiguous molecular-level structural evidence, combined with the theoretical calculation results, provides valuable insights into the formation mechanisms of EMFs, shedding light on the potential of post-formation mechanisms as a promising approach for EMF synthesis.

16.
Int J Cancer ; 153(11): 1904-1915, 2023 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-37085990

RESUMO

Novel biomarkers are essential to improve the treatment efficacy and overall survival of stage II and III colorectal cancer (CRC), allowing for personalized treatment decisions. Here, the densities of CD8+ and FOXP3+ T cells in the tumor and invasive margin were processed by immunohistochemistry and digital pathology to form a scoring system named regulatory-Immunoscore (RIS). Cox proportional hazards regression models were used to determine the risk factors associated with time to recurrence. Harrell's concordance index and the time-dependent area under the curve were used to assess model performance. A total of 1213 stage I-III DNA mismatch repair-proficient colorectal cancer (pMMR CRC) patients were randomly assigned to a training set (n = 642) and a validation set (n = 571). From the Cox multivariable analysis, the association of RIS with survival was independent of patient age, sex and anatomy-based tumor risk parameters (P < .0001). For stage II patients, chemotherapy was significantly associated with better recurrence time in patients with low (95% confidence interval [CI]: 0.11-0.54, P = .001) and intermediate (95% CI = 0.25-0.57, P < .001) RIS values. In stage III patients treated with adjuvant chemotherapy, a treatment duration of 6 or more months was significantly associated with better recurrence time in patients with intermediate RIS values (95% CI = 0.38-0.90, P = .016) when compared with duration under 6 months. Therefore, these findings suggest that RIS is reliable for predicting recurrence risk and treatment responsiveness for patients with stage I-III pMMR CRC.


Assuntos
Neoplasias do Colo , Neoplasias Colorretais , Humanos , Neoplasias do Colo/patologia , Estadiamento de Neoplasias , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Resultado do Tratamento , Quimioterapia Adjuvante , Prognóstico
17.
Biochem Biophys Res Commun ; 638: 147-154, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-36459878

RESUMO

Tissue engineering is thought to be the ideal therapy for bone defect reconstructive treatment. In this study, we present a method of utilizing micro/nano porous polycarbonate membranes (PCMs) as the extracellular matrix to cultivate the human periodontal ligament cells (hPDLCs) and investigate the osteogenic differentiation of those cells. We also compared the osteogenic enhancing abilities of different pore size PCMs. The pore diameters of the candidate membranes are 200 nm, 800 nm, 1200 nm, and 10 µm respectively, and their physical properties are identified. After seeding and cultivating on the PCMs, hPDLCs can be stimulated to undergo osteogenic differentiation, in which the 200 nm PCM is proved to have the most optimal osteo-induction ability. The results of in vivo experiments provide strong evidence suggesting that the hPDLCs stimulated by 200 nm PCM greatly accelerates the healing of bone reconstruction in mice skull defects, as well as promote the process of ectopic osteogenesis. RNA-sequencing was conducted to determine the differential mRNA expression profile during the osteogenesis process of hPDLCs on PCMs. GO and KEGG enrichment analysis were conducted to study the regulatory mechanisms, in which osteogenic marker expression such as Hippo, TGF-ß, and PI3K-Akt signaling pathways were significantly up-regulated. The up-regulation indicates the promising potential of nano porous PCMs for promoting osteogenesis for bone regeneration applications. Ultimately, signaling pathways that promote osteogenesis warrants further exploration.


Assuntos
Osteogênese , Fosfatidilinositol 3-Quinases , Humanos , Animais , Camundongos , Osteogênese/genética , Adesão Celular , Células Cultivadas , Diferenciação Celular , Ligamento Periodontal , RNA Mensageiro/genética
18.
BMC Med ; 21(1): 470, 2023 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-38031088

RESUMO

BACKGROUND: Cell-based  immunotherapy shows the therapeutic potential in sarcomas, in addition to angiogenesis-targeted tyrosine kinase inhibitor (TKI) and immune checkpoint inhibitor (ICI). Multi-antigen stimulated cell therapy-I (MASCT-I) technology is a sequential immune cell therapy for cancer, which composes of multiple antigen-loaded dendritic cell (DC) vaccines followed by the adoptive transfer of anti-tumor effector T-cells. METHODS: In this phase 1 study, we assessed MASCT-I plus camrelizumab (an ICI against PD-1) and apatinib (a highly selective TKI targeting VEGFR2) in patients with unresectable recurrent or metastatic bone and soft-tissue sarcoma after at least one line of prior systemic therapy. One MASCT-I course consisted of 3 DC subcutaneous injections, followed by 3 active T cell infusions administered 18-27 days after each DC injection. In schedule-I group, 3 DC injections were administered with a 28-day interval in all courses; in schedule-II group, 3 DC injections were administered with a 7-day interval in the first course and with a 28-day interval thereafter. All patients received intravenous camrelizumab 200 mg every 3 weeks and oral apatinib 250 mg daily. RESULTS: From October 30, 2019, to August 12, 2021, 19 patients were enrolled and randomly assigned to schedule-I group (n = 9) and schedule-II group (n = 10). Of the 19 patients, 11 (57.9%) experienced grade 3 or 4 treatment-related adverse events. No treatment-related deaths occurred. Patients in schedule-II group showed similar objective response rate (ORR) with those in schedule-I group (30.0% versus 33.3%) but had higher disease control rate (DCR; 90.0% versus 44.4%) and longer median progression-free survival (PFS; 7.7 versus 4.0 months). For the 13 patients with soft-tissue sarcomas, the ORR was 30.8%, DCR was 76.9%, and median PFS was 12.9 months; for the 6 patients with osteosarcomas, the ORR was 33.3%, the DCR was 50.0%, and median PFS was 5.7 months. CONCLUSIONS: Overall, MASCT-I plus camrelizumab and apatinib was safe and showed encouraging efficacy in advanced bone and soft-tissue sarcoma, and schedule-II administration method was recommended. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04074564.


Assuntos
Sarcoma , Humanos , Projetos Piloto , Sarcoma/tratamento farmacológico , Anticorpos Monoclonais Humanizados/uso terapêutico , Inibidores de Proteínas Quinases/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico
19.
Nat Mater ; 21(8): 917-923, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35835820

RESUMO

In-memory computing provides an opportunity to meet the growing demands of large data-driven applications such as machine learning, by colocating logic operations and data storage. Despite being regarded as the ultimate solution for high-density integration and low-power manipulation, the use of spin or electric dipole at the single-molecule level to realize in-memory logic functions has yet to be realized at room temperature, due to their random orientation. Here, we demonstrate logic-in-memory operations, based on single electric dipole flipping in a two-terminal single-metallofullerene (Sc2C2@Cs(hept)-C88) device at room temperature. By applying a low voltage of ±0.8 V to the single-metallofullerene junction, we found that the digital information recorded among the different dipole states could be reversibly encoded in situ and stored. As a consequence, 14 types of Boolean logic operation were shown from a single-metallofullerene device. Density functional theory calculations reveal that the non-volatile memory behaviour comes from dipole reorientation of the [Sc2C2] group in the fullerene cage. This proof-of-concept represents a major step towards room-temperature electrically manipulated, low-power, two-terminal in-memory logic devices and a direction for in-memory computing using nanoelectronic devices.

20.
J Org Chem ; 88(7): 4234-4243, 2023 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-36989519

RESUMO

Herein, we performed the reactions of M3N@Ih-C80 (M = Sc and Lu) with the methanol (CH3OH) solution of TBAOH (note that both CH3O- and OH- are nucleophiles) in benzonitrile (PhCN) and dimethylformamide, respectively. It is found that OH- ions rather than CH3O- ions selectively attacked the fullerene cage to form the M3N@C80--O- intermediate. Although the fullerene cage is initially attacked by OH- in both PhCN and DMF solvents, the products are quite different. In PhCN, two isomeric Sc3N@Ih-C80 fullerooxazoline heterocyclic products (1 and 2) were synthesized. Whereas, in DMF, an epoxide of Lu3N@Ih-C80 (3) was obtained. The preference for fullerooxazoline formation over that of fullerene epoxy in PhCN is well explained by density functional theory calculations. Plausible reaction mechanisms for the formation of metallofullerene oxazoline and epoxide were proposed based on the experimental and theoretical results.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA