Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 51
Filtrar
1.
J Am Chem Soc ; 146(30): 20996-21007, 2024 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-39037260

RESUMO

Conical intersections (CIs) hold significant stake in manipulating and controlling photochemical reaction pathways of molecules at interfaces and surfaces by affecting molecular dynamics therein. Currently, there is no tool for characterizing CIs at interfaces and surfaces. To this end, we have developed phase-cycling interface-specific two-dimensional electronic spectroscopy (i2D-ES) and combined it with advanced computational modeling to explore nonadiabatic CI dynamics of molecules at the air/water interface. Specifically, we integrated the phase locked pump pulse pair with an interface-specific electronic probe to obtain the two-dimensional interface-specific responses. We demonstrate that the nonadiabatic transitions of an interface-active azo dye molecule that occur through the CIs at the interface have different kinetic pathways from those in the bulk water. Upon photoexcitation, two CIs are present: one from an intersection of an optically active S2 state with a dark S1 state and the other from the intersection of the progressed S1 with the ground state S0. We find that the molecular conformations in the ground state are different for interfacial molecules. The interfacial molecules are intimately correlated with the locally populated excited state S2 being farther away from the CI region. This leads to slower nonadiabatic dynamics at the interface than in bulk water. Moreover, we show that the nonadiabatic transition from the S1 dark state to the ground state is significantly longer at the interface than that in the bulk, which is likely due to the orientationally restricted configuration of the excited state at the interface. Our findings suggest that orientational configurations of molecules manipulate reaction pathways at interfaces and surfaces.

2.
Anal Chem ; 96(33): 13607-13615, 2024 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-39126390

RESUMO

Droplet interfaces are instrumental in processes of biology, engineering, production, and environmental systems. The chemical and physical properties of heterogeneous interfaces are known to be different from those of their underlying bulk phases, and different again when considering the curved surface of submicron aerosol droplets. The recently developed technique of vibrational sum-frequency scattering (VSFS) spectroscopy from airborne particles has emerged as an interface-specific method for the in situ analysis of this unique system. While the technique has shown promise in debut works, a quantitative analysis of the VSFS system has not yet been performed. Here we provide a comprehensive analysis of a VSFS spectrometer with reference to the well-documented planar analog. We decompose the VSFS signal into coherent and incoherent as well as resonant and nonresonant components as a function of incident pulse delay time. We then quantify and compare resonant and nonresonant VSFS and VSFG experimental data using the same laser and detection systems. Using the air/water interface as a guide, we show that the resonant and nonresonant contributions to the SF responses are comparable for the two systems by extracting second-order susceptibilities and hyperpolarizabilities, and using them to estimate single-particle susceptibilities. A quantitative analysis of the signal detection systems for the scattering and planar geometries is made, and conversion efficiencies for VSFG, VSFS, and other nonlinear scattering experiments are compared. Lastly, the possibility of a low-repetition (1 kHz) VSFS spectrometer is considered, determining that it may be possible with modern laser technology but is inevitably less efficient than a high-repetition (100 kHz) system. Though this multistep analysis we obtain a better understanding of the components of the VSFS signal from aerosol particles, further validate the feasibility of the experiments, and provide insight to those wishing to conduct similar experiments and how they may be improved.

3.
J Chem Phys ; 161(11)2024 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-39291691

RESUMO

Two-dimensional electronic spectroscopy (2D-ES) has become an important technique for studying energy transfer, electronic coupling, and electronic-vibrational coherence in the past ten years. However, since 2D-ES is not interface specific, the electronic information at surfaces and interfaces could not be demonstrated clearly. Two-dimensional electronic sum-frequency generation (2D-ESFG) is an emerging spectroscopic technique that explores the correlations between different interfacial electronic transitions and is the extension of 2D-ES to surface and interfacial specificity. In this work, we present the detailed development and implementation of phase-cycling 2D-ESFG spectroscopy using an acousto-optic pulse shaper in a pump-probe geometry. With the pulse pair generated by a pulse shaper rather than optical devices based on birefringence or interference, this 2D-ESFG setup enables rapid scanning, phase cycling, and the separation of rephasing and nonrephasing signals. In addition, by collecting data in a rotating frame, we greatly improve experimental efficiency. We demonstrate the method for azo-derivative molecules at the air/water interface. This method could be readily extended to different interfaces and surfaces. The unique phase-cycling 2D-ESFG technique enables one to quantify the energy transfer, charge transfer, electronic coupling, and many other electronic properties and dynamics at surfaces and interfaces with precision and relative ease of use. Our goal in this article is to present the fine details of the fourth-order nonlinear optical technique in a manner that is comprehensive, succinct, and approachable such that other researchers can implement, improve, and adapt it to probe unique and innovative problems to advance the field.

4.
J Med Virol ; 95(10): e29132, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37792307

RESUMO

Esophageal squamous cell carcinoma (ESCC) may be correlated with HPV infection, and the mechanism underlying the ESCC formation induced by HPV16 infection remains elusive. Here, we overexpressed HPV16 E6 and E7 and coordinated the overexpression of these two genes in EPC2 and ESCC cells. We found that E7 and coordinated expression of E6 and E7 promoted the proliferation of EPC2 cells, and upregulation of shh was responsible for cell proliferation since the use of vismodegib led to the failure of organoid formation. Meanwhile, overexpression of E6 and E7 in ESCC cells promoted cell proliferation, migration, and invasion in vitro. Importantly, E6 and E7 coordinately increased the capability of tumor growth in nude mice, while vismodegib slowed the growth of tumors in NCG mice. Moreover, a series of genes and proteins changed in cell lines after overexpression of the E6 and E7 genes, the potential biological processes and pathways were systematically analyzed using a bioinformatics assay. Together, these findings suggest that the activation of the hedgehog pathway induced by HPV16 infection may initially transform basal cells in the esophagus and promote following malignant processes in ESCC cells. The application of hedgehog inhibitors may represent a therapeutic avenue for ESCC treatment.


Assuntos
Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , Infecções por Papillomavirus , Animais , Camundongos , Proteínas Hedgehog/genética , Carcinoma de Células Escamosas do Esôfago/genética , Papillomavirus Humano 16/genética , Infecções por Papillomavirus/complicações , Neoplasias Esofágicas/genética , Camundongos Nus
5.
Langmuir ; 39(31): 10724-10743, 2023 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-37497860

RESUMO

Surface properties of nanodroplets and microdroplets are intertwined with their immense applicability in biology, medicine, production, catalysis, the environment, and the atmosphere. However, many means for analyzing droplets and their surfaces are destructive, non-interface-specific, not conducted under ambient conditions, require sample substrates, conducted ex situ, or a combination thereof. For these reasons, a technique for surface-selective in situ analyses under any condition is necessary. This feature article presents recent developments in second-order nonlinear optical scattering techniques for the in situ interfacial analysis of aerosol droplets in the air. First, we describe the abundant utilization of such droplets across industries and how their unique surface properties lead to their ubiquitous usage. Then, we describe the fundamental properties of droplets and their surfaces followed by common methods for their study. We next describe the fundamental principles of sum-frequency generation (SFG) spectroscopy, the Langmuir adsorption model, and how they are used together to describe adsorption processes at planar liquid and droplet surfaces. We also discuss the history of developments of second-order scattering from droplets suspended in dispersive media and introduce second-harmonic scattering (SHS) and sum-frequency scattering (SFS) spectroscopies. We then go on to outline the developments of SHS, electronic sum-frequency scattering (ESFS), and vibrational sum-frequency scattering (VSFS) from droplets in the air and discuss the fundamental insights about droplet surfaces that the techniques have provided. Finally, we describe some of the areas of nonlinear scattering from airborne droplets which need improvement as well as potential future directions and utilizations of SHS, ESFS, and VSFS throughout environmental systems, interfacial chemistry, and fundamental physics. The goal of this feature article is to spread knowledge about droplets and their unique surface properties as well as introduce second-order nonlinear scattering to a broad audience who may be unaware of recent progress and advancements in their applicability.

6.
J Chem Phys ; 158(21)2023 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-37278478

RESUMO

Understanding the electric double layer (EDL) of the metal electrode-electrolyte interface is essential to electrochemistry and relevant disciplines. In this study, potential-dependent electrode Sum Frequency Generation (SFG) intensities of polycrystalline gold electrodes in HClO4 and H2SO4 electrolytes were thoroughly analyzed. The potential of zero charges (PZC) of the electrodes was -0.06 and 0.38 V in HClO4 and H2SO4, respectively, determined from differential capacity curves. Without specific adsorption, the total SFG intensity was dominated by the contribution from the Au surface and increased similar to that of the visible (VIS) wavelength scanning, which pushed the SFG process closer to the double resonant condition in HClO4. However, the EDL contributed about 30% SFG signal with specific adsorption in H2SO4. Below PZC, the total SFG intensity was dominated by the Au surface contribution and increased with potential at a similar slope in these two electrolytes. Around PZC, as the EDL structure became less ordered and the electric field changed direction, there would be no EDL SFG contribution. Above PZC, the total SFG intensity increased much more rapidly with potential in H2SO4 than in HClO4, which suggested that the EDL SFG contribution kept increasing with more specific adsorbed surface ions from H2SO4.

7.
J Phys Chem A ; 126(23): 3758-3764, 2022 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-35667005

RESUMO

Small-volume nanodroplets play an increasingly common role in chemistry and biology. Such nanodroplets are believed to have unique chemical and physical properties at the interface between a droplet and its surrounding medium, however, they are underexamined. In this study, we present the novel technique of vibrational sum frequency scattering (VSFS) spectroscopy as an interface-specific, high-performance method for the in situ investigation of nanodroplets with sub-micron radii; as well as the droplet bulk through simultaneous hyper-Raman scattering (HRS) spectroscopy. We use laboratory-generated nanodroplets from aqueous alcohol solutions to demonstrate this technique's ability to separate the vibrational phenomena which take place at droplet surfaces from the underlying bulk phase. In addition, we systemically examine interfacial spectra of nanodroplets containing methanol, ethanol, 1-propanol, and 1-butanol through VSFS. Furthermore, we demonstrate interfacial differences between such nanodroplets and their analogous planar surfaces. The sensitivity of this technique to probe droplet surfaces with few-particle density at standard conditions validates VSFS as an analytical technique for the in situ investigation of small nanodroplets, providing breakthrough information about these species of ever-increasing relevance.


Assuntos
Análise Espectral Raman , Água , Metanol , Vibração , Água/química
8.
Lancet Oncol ; 22(8): 1162-1174, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34174189

RESUMO

BACKGROUND: The addition of camrelizumab to gemcitabine and cisplatin showed promising activity as first-line therapy in patients with recurrent or metastatic nasopharyngeal carcinoma in a phase 1 trial. We therefore compared camrelizumab plus gemcitabine and cisplatin with placebo plus gemcitabine and cisplatin in a randomised phase 3 trial. METHODS: In this randomised, double-blind, phase 3 trial done at 28 hospitals in China, patients were eligible if they were aged 18-75 years, had an Eastern Cooperative Oncology Group (ECOG) performance status of 0-1, and had previously untreated recurrent or metastatic nasopharyngeal carcinoma. Patients were randomly assigned (1:1; using an interactive web-response system with a block size of four) to receive either camrelizumab (200 mg on day 1) or matching placebo intravenously, plus gemcitabine and cisplatin (gemcitabine 1000 mg/m2 on days 1 and 8; cisplatin 80 mg/m2 on day 1) intravenously every 3 weeks for four to six cycles, followed by maintenance therapy with camrelizumab or placebo, until radiographic progression, unacceptable toxicity, start of new anticancer treatment, investigator decision, or withdrawal of consent. Stratification factors used in randomisation were liver metastases, previous radical concurrent chemoradiotherapy, and ECOG performance status. The allocation sequence was generated by an independent randomisation group. The primary endpoint was progression-free survival per independent review committee. The significance threshold for independent review committee-assessed progression-free survival was p=0·0086 (one-sided) at the interim analysis. Efficacy and safety analyses included all patients who received at least one dose of study drug. This trial is registered with ClinicalTrials.gov, NCT03707509, and is closed for enrolment but is ongoing. FINDINGS: Between Nov 13, 2018, and Nov 29, 2019, 343 patients were screened and 263 were eligible and were randomly assigned to the camrelizumab group (n=134) or placebo group (n=129). At the prespecified interim analysis (June 15, 2020), independent review committee-assessed progression-free survival was significantly longer in the camrelizumab group (median 9·7 months [95% CI 8·3-11·4]) than in the placebo group (median 6·9 months [5·9-7·3]; hazard ratio 0·54 [95% CI 0·39-0·76]; one-sided p=0·0002). As of Dec 31, 2020, the most common grade 3 or worse adverse events of any cause were decreased white blood cell count (89 [66%] of 134 patients in the camrelizumab group vs 90 [70%] of 129 patients in the placebo group), decreased neutrophil count (86 [64%] vs 85 [66%]), anaemia (53 [40%] vs 57 [44%]), and decreased platelet count (53 [40%] vs 52 [40%]). Serious adverse events were reported in 59 (44%) of 134 patients in the camrelizumab group and 48 (37%) of 129 patients in the placebo group. Treatment-related deaths occurred in five (4%) patients in the camrelizumab group (two unknown cause of death, one multiple organ dysfunction syndrome, one pharyngeal haemorrhage, and one arrhythmia) and one (<1%) patient in the placebo group (unknown cause of death). INTERPRETATION: Our findings suggest that camrelizumab plus gemcitabine and cisplatin could be a new standard of care for patients with recurrent or metastatic nasopharyngeal carcinoma in the first-line setting. Longer follow-up is needed to confirm this conclusion. FUNDING: Jiangsu Hengrui Pharmaceuticals (formerly Jiangsu Hengrui Medicine). TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma Nasofaríngeo/tratamento farmacológico , Neoplasias Nasofaríngeas/tratamento farmacológico , Adulto , Idoso , Cisplatino/uso terapêutico , Desoxicitidina/análogos & derivados , Desoxicitidina/uso terapêutico , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Gencitabina
9.
JAMA ; 326(10): 916-925, 2021 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-34519801

RESUMO

Importance: Standard first-line therapy for advanced or metastatic esophageal carcinoma is chemotherapy, but the prognosis remains poor. Camrelizumab (an anti-programmed death receptor 1 [PD-1] antibody) showed antitumor activity in previously treated advanced or metastatic esophageal squamous cell carcinoma. Objective: To evaluate the efficacy and adverse events of camrelizumab plus chemotherapy vs placebo plus chemotherapy as a first-line treatment in advanced or metastatic esophageal squamous cell carcinoma. Design, Setting, and Participants: This randomized, double-blind, placebo-controlled, multicenter, phase 3 trial (ESCORT-1st study) enrolled patients from 60 hospitals in China between December 3, 2018, and May 12, 2020 (final follow-up, October 30, 2020). A total of 751 patients were screened and 596 eligible patients with untreated advanced or metastatic esophageal squamous cell carcinoma were randomized. Interventions: Patients were randomized 1:1 to receive either camrelizumab 200 mg (n = 298) or placebo (n = 298), combined with up to 6 cycles of paclitaxel (175 mg/m2) and cisplatin (75 mg/m2). All treatments were given intravenously every 3 weeks. Main Outcomes and Measures: Coprimary end points were overall survival (significance threshold, 1-sided P < .02) and progression-free survival (significance threshold, 1-sided P < .005). Results: Of the 596 patients randomized (median age, 62 years [interquartile range, 56-67 years]; 523 men [87.8%]), 1 patient in the placebo-chemotherapy group did not receive planned treatment. A total of 490 patients (82.2%) had discontinued the study treatment. The median follow-up was 10.8 months. The overall survival for the camrelizumab-chemotherapy group was a median of 15.3 months (95% CI, 12.8-17.3; 135 deaths) vs a median of 12.0 months (95% CI, 11.0-13.3; 174 deaths) for the placebo-chemotherapy group (hazard ratio [HR] for death, 0.70 [95% CI, 0.56-0.88]; 1-sided P = .001). Progression-free survival for camrelizumab plus chemotherapy was a median of 6.9 months (95% CI, 5.8-7.4; 199 progression or deaths) vs 5.6 months (95% CI, 5.5-5.7; 229 progression or deaths) for the placebo-chemotherapy group (HR for progression or death, 0.56 [95% CI, 0.46-0.68]; 1-sided P < .001). Treatment-related adverse events of grade 3 or higher occurred in 189 patients (63.4%) in the camrelizumab-chemotherapy group and 201 (67.7%) in the placebo-chemotherapy group, including treatment-related deaths among 9 patients (3.0%) and 11 patients (3.7%), respectively. Conclusions and Relevance: Among patients with advanced or metastatic esophageal squamous cell carcinoma, the addition of camrelizumab to chemotherapy, compared with placebo and chemotherapy, significantly improved overall survival and progression-free survival. Trial Registration: ClinicalTrials.gov Identifier: NCT03691090.


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Esofágicas/tratamento farmacológico , Carcinoma de Células Escamosas do Esôfago/tratamento farmacológico , Adulto , Idoso , Anticorpos Monoclonais Humanizados/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Cisplatino/administração & dosagem , Método Duplo-Cego , Neoplasias Esofágicas/mortalidade , Carcinoma de Células Escamosas do Esôfago/mortalidade , Carcinoma de Células Escamosas do Esôfago/secundário , Feminino , Humanos , Imunoterapia , Masculino , Pessoa de Meia-Idade , Paclitaxel/administração & dosagem , Placebos , Intervalo Livre de Progressão , Qualidade de Vida , Análise de Sobrevida
10.
Lancet Oncol ; 21(6): 832-842, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32416073

RESUMO

BACKGROUND: Patients with advanced or metastatic oesophageal squamous cell carcinoma have poor prognosis and few treatment options after first-line therapy. We aimed to assess efficacy and safety of the anti-PD-1 antibody camrelizumab versus investigator's choice of chemotherapy in previously treated patients. METHODS: ESCORT is a randomised, open-label, phase 3 study of patients aged 18 to 75 years with a histological or cytological diagnosis of advanced or metastatic oesophageal squamous cell carcinoma done at 43 hospitals in China. Eligible patients had an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1, and had progressed on, or were intolerant to, first-line standard therapy. Patients were randomly assigned (1:1) to camrelizumab (200 mg every 2 weeks) or chemotherapy with docetaxel (75 mg/m2 every 3 weeks) or irinotecan (180 mg/m2 every 2 weeks), all given intravenously. Central randomisation was done using the Randomization and Trial Supply Management system with block size randomly generated as four or six and stratified by disease and ECOG performance status. The primary endpoint was overall survival, assessed in randomised patients who had received at least one dose of treatment. Safety was assessed in all treated patients. The trial is registered with ClinicalTrials.gov, NCT03099382, and is closed to new participants. FINDINGS: From May 10, 2017, to July 24, 2018, 457 (75%) of 607 screened patients were randomly assigned to treatment, of whom 228 received camrelizumab treatment and 220 received chemotherapy. As of data cutoff on May 6, 2019, with a median follow-up time of 8·3 months (IQR 4·1-12·8) in the camrelizumab group and 6·2 months (3·6-10·1) in the chemotherapy group, median overall survival was 8·3 months (95% CI 6·8-9·7) in the camrelizumab group and 6·2 months (5·7-6·9) in the chemotherapy group (hazard ratio 0·71 [95% CI 0·57-0·87]; two-sided p=0·0010). The most common treatment-related adverse events of grade 3 or worse were anaemia (camrelizumab vs chemotherapy: six [3%] vs 11 [5%]), abnormal hepatic function (four [2%] vs one [<1%]), and diarrhoea (three [1%] vs nine [4%]). Serious treatment-related adverse events occurred in 37 (16%) of 228 patients in the camrelizumab group, and in 32 (15%) of 220 patients in the chemotherapy group. Ten treatment-related deaths occurred, seven (3%) in the camrelizumab group (three deaths from unknown causes, one enterocolitis, one hepatic function abnormal, one pneumonitis, and one myocarditis) and three (1%) in the chemotherapy group (two deaths from unknown causes, and one gastrointestinal haemorrhage). INTERPRETATION: Second-line camrelizumab significantly improved overall survival in patients with advanced or metastatic oesophageal squamous cell carcinoma compared with chemotherapy, with a manageable safety profile. It might represent a potential option of standard second-line treatment for patients with oesophageal squamous cell carcinoma in China. FUNDING: Jiangsu Hengrui Medicine.


Assuntos
Anticorpos Monoclonais Humanizados/administração & dosagem , Antineoplásicos Imunológicos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Docetaxel/administração & dosagem , Neoplasias Esofágicas/tratamento farmacológico , Carcinoma de Células Escamosas do Esôfago/tratamento farmacológico , Irinotecano/administração & dosagem , Adolescente , Adulto , Idoso , Anticorpos Monoclonais Humanizados/efeitos adversos , Antineoplásicos Imunológicos/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , China , Progressão da Doença , Docetaxel/efeitos adversos , Neoplasias Esofágicas/imunologia , Neoplasias Esofágicas/mortalidade , Neoplasias Esofágicas/patologia , Carcinoma de Células Escamosas do Esôfago/imunologia , Carcinoma de Células Escamosas do Esôfago/mortalidade , Carcinoma de Células Escamosas do Esôfago/secundário , Feminino , Humanos , Irinotecano/efeitos adversos , Masculino , Pessoa de Meia-Idade , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/imunologia , Intervalo Livre de Progressão , Transdução de Sinais , Fatores de Tempo , Adulto Jovem
11.
Angew Chem Int Ed Engl ; 59(50): 22397-22402, 2020 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-32893447

RESUMO

Driven by the persisting poor understanding of the sluggish kinetics of the hydrogen evolution reaction (HER) on Pt in alkaline media, a direct correlation of the interfacial water structure and activity is still yet to be established. Herein, using Pt and Pt-Ni nanoparticles we first demonstrate a strong dependence of the proton donor structure on the HER activity and pH. The structure of the first layer changes from the proton acceptors to the donors with increasing pH. In the base, the reactivity of the interfacial water varied its structure, and the activation energies of water dissociation increased in the sequence: the dangling O-H bonds < the trihedrally coordinated water < the tetrahedrally coordinated water. Moreover, optimizing the adsorption of H and OH intermediates can re-orientate the interfacial water molecules with their H atoms pointing towards the electrode surface, thereby enhancing the kinetics of HER. Our results clarified the dynamic role of the water structure at the electrode-electrolyte interface during HER and the design of highly efficient HER catalysts.

12.
Phys Chem Chem Phys ; 21(45): 25047-25053, 2019 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-31690901

RESUMO

As an important pathway for energy storage and a key reaction in the carbon cycle, the CO2 electrochemical reduction reaction has recently gained significant interest. A variety of catalysts have been used to approach this topic experimentally and theoretically; however, the molecular level insight into the reaction mechanism is lacking due to the complexity of the surface processes and the challenges in probing the intermediate species. In this study, CO2 reduction reactions on polycrystalline Cu and Au electrodes were investigated in 0.1 M CO2-saturated NaHCO3 solution. In situ sum frequency generation (SFG) spectroscopy has been adopted to access the intermediates and products on the metal electrodes. On the Au electrode, only linearly adsorbed CO could be detected, and the reduction produced no hydrocarbon species. On the Cu electrode, C-H stretching vibrations corresponding to surface-adsorbed ethoxy species were observed, but no CO vibrations can be detected with SFG. The results revealed that the CO randomly adsorbed on the Cu surface, and the multiple orientations of the adsorbed species may be the reason for the formation of C-C bonding. These results demonstrate direct molecular level evidence for different reaction pathways on the Cu and Au electrodes.

13.
Biochem J ; 472(3): 309-18, 2015 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-26438880

RESUMO

Macrophages within adipose tissue play a key role in mediating inflammatory responses in adipose tissue that are associated with obesity-related metabolic complications. In an effort to identify novel proteins secreted from adipocytes that may negatively regulate macrophage inflammation, we found that peroxiredoxin (PRX)-like 2 activated in M-CSF stimulated monocytes (PAMM), a CXXC-type PRX-like 2 domain-containing redox regulatory protein, is a novel secreted protein with potent anti-inflammatory properties. PAMM is secreted from mature human adipocytes but not preadipocytes. Overexpression of PAMM significantly attenuated lipopolysaccharide (LPS)-induced macrophage inflammation. Incubation of macrophages with adipocyte-conditional medium treated with anti-PAMM antibody significantly enhanced LPS-induced interleukin-12 (IL-12) expression in Raw264.7 cells. In addition, incubation of Raw264.7 cells with purified PAMM protein had a similar anti-inflammatory effect. Moreover, forced expression of PAMM in Raw264.7 cells resulted in decreased LPS-induced ERK1/2, p38 and c-Jun N-terminal kinase (JNK) phosphorylation, suggesting that PAMM exerted the anti-inflammatory function probably by suppressing the mitogen-activated protein kinase (MAPK) signalling pathway. Mutations in the CXXC motif of PAMM that suppressed its anti-redox activity were still able to suppress production of inflammatory cytokines in LPS-stimulated macrophages, suggesting that PAMM's anti-inflammatory properties may be independent of its antioxidant properties. Finally, PAMM was highly expressed in both white (WAT) and brown adipose tissues (BAT) and further increased in obesity status. Our results suggest that adipocyte-derived PAMM may suppress macrophage activation by inhibiting MAPK signalling pathway.


Assuntos
Adipócitos/metabolismo , Sistema de Sinalização das MAP Quinases , Ativação de Macrófagos , Macrófagos/metabolismo , Peroxirredoxinas/metabolismo , Adipócitos/imunologia , Adipócitos/patologia , Motivos de Aminoácidos , Animais , Células HEK293 , Humanos , Inflamação/induzido quimicamente , Inflamação/genética , Inflamação/imunologia , Inflamação/metabolismo , Inflamação/patologia , Lipopolissacarídeos/toxicidade , MAP Quinase Quinase 4/genética , MAP Quinase Quinase 4/imunologia , MAP Quinase Quinase 4/metabolismo , Macrófagos/imunologia , Macrófagos/patologia , Camundongos , Proteína Quinase 1 Ativada por Mitógeno/genética , Proteína Quinase 1 Ativada por Mitógeno/imunologia , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/genética , Proteína Quinase 3 Ativada por Mitógeno/imunologia , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Mutação , Peroxirredoxinas/genética , Peroxirredoxinas/imunologia , Proteínas Quinases p38 Ativadas por Mitógeno/genética , Proteínas Quinases p38 Ativadas por Mitógeno/imunologia , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
14.
Med Sci Monit ; 21: 1276-87, 2015 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-25940978

RESUMO

BACKGROUND: Different sensitivity of advanced cervical cancer to irradiation can decrease effectiveness of radiotherapy in some cases. We attempted to identify the differentially expressed genes in residual cervical cancer after radiotherapy that might be associated with poor prognosis and radioresistance. MATERIAL/METHODS: Differential genes expression was identified by an oligonucleotide microarray in cervical cancer tissues before radiation and after a 50-Gy dose of radiation. The microarray results were validated by quantitative real-time PCR. CXCL12 was validated by immunohistochemistry in paraffin-embedded cervical cancer tissues before radiotherapy. The relationship between the differentiated gene and prognosis was validated by survival analysis. RESULTS: Hierarchic cluster analysis identified 238 differentiated genes that exhibited ≥3.0-fold change and p<0.05. We found 111 genes that were in persistent up-regulation and 127 in persistent down-regulation after a 50-Gy dose of radiation when compared with the control group. These genes were involved in processes such as cell growth and death, cell-apoptosis, cell cycle regulation, cell signaling, DNA synthesis and repair, and cell adhesion. High differential expression of CXCL12, CD74, FGF7, COL14A1, PRC1, and RAD54L genes was validated by quantitative PCR before and after radiotherapy. Survival analysis results showed that the high expression of CXCL12 was closely related to poor prognosis. CONCLUSIONS: The higher expression of CXCL12 might be informative regarding poor prognosis in patients undergoing radical radiotherapy. The differentially expressed genes identified in our study might provide a new method for diagnosis and treatment of radioresistance in cervical cancer.


Assuntos
Carcinoma de Células Escamosas/radioterapia , Regulação Neoplásica da Expressão Gênica , Proteínas de Neoplasias/genética , Neoplasias do Colo do Útero/radioterapia , Adulto , Idoso , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patologia , Quimiocina CXCL12/biossíntese , Quimiocina CXCL12/genética , Análise por Conglomerados , Feminino , Humanos , Estimativa de Kaplan-Meier , Pessoa de Meia-Idade , Proteínas de Neoplasias/biossíntese , Análise de Sequência com Séries de Oligonucleotídeos , Prognóstico , Tolerância a Radiação , Dosagem Radioterapêutica , Reação em Cadeia da Polimerase em Tempo Real , Resultado do Tratamento , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/patologia
15.
Med Sci Monit ; 21: 318-25, 2015 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-25623525

RESUMO

BACKGROUND: The aim of the study was to assess the role of irradiation in the expression of HIF-1a, VEGF, and P53 in human cervical carcinoma cells under a simulated hypoxia environment. MATERIAL/METHODS: The tetrazolium-based colorimetric cellular assay (MTT) and flow cytometry (FCM) were used to detect the growth inhibition rates of HeLa cells in different groups. Western blot and reverse transcription polymerase chain reaction (RT-PCR) were used to observe gene and protein expression of HIF-1α, VEGF, and P53. The effect of HIF-1α on radioresistance and expression of VEGF and P53 were confirmed with the HIF-1α siRNA in vivo and in vitro. RESULTS: Hypoxic conditions enhanced the radiation resistance dependent on HIF-1α by elevating the expression of VEGF and inhibiting the expression of p53. After transfection of HIF-1α siRNA, MTT assay showed the survival rates were increased in the cells receiving irradiation under hypoxia. The expression of VEGF decreased significantly more than that of cells transfected with sense oligodeoxynucleotides, while an opposite result was found in the expression of P53 protein in the same X-ray dose (p<0.05). In vivo, the radioresistance of HIF-1α was consistent with the results in vitro. CONCLUSIONS: In the future, we might inhibit human cervical cancer progression and enhance the radiosensitivity by inhibiting HIF-1α to reduce VEGF and increase P53 expression. The challenge is how to use this information to optimize cancer therapy.


Assuntos
Apoptose , Carcinoma/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Neoplasias do Colo do Útero/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Animais , Progressão da Doença , Feminino , Citometria de Fluxo , Células HeLa , Humanos , Hipóxia , Camundongos , Camundongos Endogâmicos BALB C , Oligonucleotídeos/química , RNA Interferente Pequeno/metabolismo , Raios X
16.
Breast Cancer ; 31(3): 426-439, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38472737

RESUMO

Enhancing radiotherapy sensitivity is crucial for improving treatment outcomes in triple-negative breast cancer (TNBC) patients. In this study, we investigated the potential of targeting Elongin B (ELOB) to enhance radiotherapy efficacy in TNBC. Analysis of TNBC patient cohorts revealed a significant association between high ELOB expression and poor prognosis in patients who received radiation therapy. Mechanistically, we found that ELOB plays a pivotal role in regulating mitochondrial function via modulating mitochondrial DNA expression and activities of respiratory chain complexes. Targeting ELOB effectively modulated mitochondrial function, leading to enhanced radiosensitivity in TNBC cells. Our findings highlight the importance of ELOB as a potential therapeutic target for improving radiotherapy outcomes in TNBC. Further exploration of ELOB's role in enhancing radiotherapy efficacy may provide valuable insights for developing novel treatment strategies for TNBC patients.


Assuntos
Tolerância a Radiação , Neoplasias de Mama Triplo Negativas , Feminino , Humanos , DNA Mitocondrial/genética , Regulação Neoplásica da Expressão Gênica/efeitos da radiação , Mitocôndrias/efeitos da radiação , Mitocôndrias/metabolismo , Prognóstico , Fatores de Transcrição/metabolismo , Neoplasias de Mama Triplo Negativas/radioterapia , Neoplasias de Mama Triplo Negativas/patologia
17.
World J Gastrointest Oncol ; 16(1): 1-7, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38292836

RESUMO

Four major studies (Checkmate577, Keynote-590, Checkmate649 and Attraction-4) of locally advanced esophageal cancer published in 2020 have established the importance of immunotherapy, represented by anti-programmed death protein (PD)-1 in postoperative adjuvant treatment and advanced first-line treatment of locally advanced or advanced esophageal cancer and esophagogastric junction cancer, from the aspects of proof of concept, long-term survival, overall survival rate and progression-free survival. For unresectable or inoperable nonmetastatic esophageal cancer, concurrent radiotherapy and chemotherapy is the standard treatment recommended by various guidelines. Because its curative effect is still not ideal, it is necessary to explore radical radiotherapy and chemotherapy in the future, and it is considered to be promising to combine them with immunotherapeutic drugs such as anti-PD-1. This paper mainly discusses how to combine radical concurrent radiotherapy and chemotherapy with immunotherapy for unresectable local advanced esophageal cancer.

18.
Anim Nutr ; 18: 419-432, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39309969

RESUMO

Intestine derived lipopolysaccharide (LPS) is closely related to systemic inflammation and disorders, yet little is known about its roles in the weanling stress of piglets and its potential as a nutritional intervention target. This study aimed to investigate the potential of essential oils (EO) and organic acids (OA) in mitigating weaning stress in piglets by modulating the circulation of intestine derived LPS. Seventy-two weaned piglets at 21 d old with body weight of 8.12 ± 0.168 kg were randomly divided into a control group (CON) and an experimental group, each consisting of six pens with six piglets per pen, and were fed either a basal diet or a basal diet supplemented with 3 kg/t OA + 500 g/t EO (EO + OA). On the 14th day of the feeding trial, 12 weaned piglets were randomly selected from the CON group, and 6 piglets were selected from the experimental group. Based on diet composition and stress treatment, these 18 piglets were divided into the following three groups: 1) CON group. Piglets were fed a basal diet and received an intraperitoneal injection of saline as a control. 2) LPS group. Piglets were fed a basal diet and received an intraperitoneal injection of LPS (100 µg/kg body weight) to induce stress. 3) EO + OA + LPS group. Piglets were fed a basal diet supplemented with EO and OA and received an intraperitoneal injection of LPS (100 µg/kg body weight) to induce stress. The results showed that EO + OA significantly ameliorated the oxidative imbalance and inflammation disorder induced by LPS in piglets' serum and intestine by inhibiting the activation of the Toll-like receptor 4 (TLR4)/nuclear factor-kappa B (NF-κB)/mitogen-activated protein kinase (MAPK) signaling pathway. Furthermore, compared to the LPS group, supplementation with EO + OA restored LPS-induced reductions in Bcl-2 protein expression in the piglets' intestines (P < 0.05) and mitigated morphological damage; it also enhanced both the protein expression and relative gene expression of the tight junction proteins occludin and claudin-1 (P < 0.05), and reduced the plasma diamine oxidase activity (DAO) and LPS content (P < 0.05). Compared to the CON group, supplementation with EO + OA altered the composition of the intestinal microbiota, increasing beneficial bacteria relative abundance (Faecalibacterium) (P < 0.05) and decreasing harmful bacteria relative abundance [Rikenellaceae_RC9_gut_group (P < 0.01), Negativibacillus (P < 0.05)]. Further analysis revealed that plasma LPS content in piglets was negatively correlated with the relative abundance of Faecalibacterium (r = -0.662, P = 0.021), Akkermansia (r = -0.492, P = 0.031), and average daily gain (ADG) (r = -0.912, P = 0.041). Plasma LPS content was also positively correlated with the plasma inflammatory factors interleukin (IL)-1ß (r = 0.591, P = 0.021), IL-6 (r = 0.623, P = 0.021), IL-12 (r = 561, P = 0.031) contents, and the relative abundance of Negativibacillus (r = 0.712, P = 0.041). In summary, the addition of EO + OA prevents the leakage of intestine derived LPS into the circulation by improving intestinal integrity and microbiota composition, thereby enhancing antioxidant and anti-inflammatory abilities and growth performance of weaned piglets.

19.
Antioxidants (Basel) ; 13(2)2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38397739

RESUMO

This study aims to investigate the impact of dietary supplementation with selenium yeast (SeY) and glycerol monolaurate (GML) on the transfer of antioxidative capacity between the mother and fetus during pregnancy and its underlying mechanisms. A total of 160 sows with similar body weight and parity of 3-6 parity sows were randomly and uniformly allocated to four groups (n = 40) as follows: CON group, SeY group, GML group, and SG (SeY + GML) group. Animal feeding started from the 85th day of gestation and continued to the day of delivery. The supplementation of SeY and GML resulted in increased placental weight and reduced lipopolysaccharide (LPS) levels in sow plasma, placental tissues, and piglet plasma. Furthermore, the redox balance and inflammatory markers exhibited significant improvements in the plasma of sows fed with either SeY or GML, as well as in their offspring. Moreover, the addition of SeY and GML activated the Nrf2 signaling pathway, while downregulating the expression of pro-inflammatory genes and proteins associated with inflammatory pathways (MAPK and NF-κB). Vascular angiogenesis and nutrient transportation (amino acids, fatty acids, and glucose) were upregulated, whereas apoptosis signaling pathways within the placenta were downregulated with the supplementation of SeY and GML. The integrity of the intestinal and placental barriers significantly improved, as indicated by the increased expression of ZO-1, occludin, and claudin-1, along with reduced levels of DLA and DAO with dietary treatment. Moreover, supplementation of SeY and GML increased the abundance of Christensenellaceae_R-7_group, Clostridium_sensus_stricto_1, and Bacteroidota, while decreasing levels of gut microbiota metabolites LPS and trimethylamine N-oxide. Correlation analysis demonstrated a significant negative relationship between plasma LPS levels and placental weight, oxidative stress, and inflammation. In summary, dietary supplementation of SeY and GML enhanced the transfer of antioxidative capacity between maternal-fetal during pregnancy via gut-placenta axis through modulating sow microbiota composition.

20.
Heliyon ; 10(7): e28090, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38571596

RESUMO

Background: Lung adenocarcinoma (LUAD) has a complex tumor heterogeneity. Our research attempts to clearness LUAD subtypes and build a reliable prognostic signature according to the activity changes of the hallmark and immunologic gene sets. Methods: According to The Cancer Genome Atlas (TCGA) - LUAD dataset, changes in marker and immune gene activity were analyzed, followed by identification of prognosis-related differential gene sets (DGSs) and their related LUAD subtypes. Survival analysis, correlation with clinical characteristics, and immune microenvironment assessment for subtypes were performed. Moreover, the differentially expressed genes (DEGs) between different subtypes were identified, followed by the construction of a prognostic risk score (RS) model and nomogram model. The tumor mutation burden (TMB) and tumor immune dysfunction and exclusion (TIDE) of different risk groups were compared. Results: Two LUAD subtypes were determined according to the activity changes of the hallmark and immunologic gene sets. Cluster 2 had worse prognosis, more advanced tumor and clinical stages than cluster 1. Moreover, a prognostic RS signature was established using two LUAD subtype-related DEGs, which could stratify patients at different risk levels. Nomogram model incorporated RS and clinical stage exerted good prognostic performance in LUAD patients. A shorter survival time and higher TMB were observed in the high-risk patients. Conclusions: Our findings revealed that our constructed prognostic signature could exactly predict the survival status of LUAD cases, which was helpful in predicting the prognosis and guiding personalized therapeutic strategies for LUAD.

SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa