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1.
Mol Cell ; 84(10): 1964-1979.e6, 2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38759628

RESUMO

The role of the mitochondrial electron transport chain (ETC) in regulating ferroptosis is not fully elucidated. Here, we reveal that pharmacological inhibition of the ETC complex I reduces ubiquinol levels while decreasing ATP levels and activating AMP-activated protein kinase (AMPK), the two effects known for their roles in promoting and suppressing ferroptosis, respectively. Consequently, the impact of complex I inhibitors on ferroptosis induced by glutathione peroxidase 4 (GPX4) inhibition is limited. The pharmacological inhibition of complex I in LKB1-AMPK-inactivated cells, or genetic ablation of complex I (which does not trigger apparent AMPK activation), abrogates the AMPK-mediated ferroptosis-suppressive effect and sensitizes cancer cells to GPX4-inactivation-induced ferroptosis. Furthermore, complex I inhibition synergizes with radiotherapy (RT) to selectively suppress the growth of LKB1-deficient tumors by inducing ferroptosis in mouse models. Our data demonstrate a multifaceted role of complex I in regulating ferroptosis and propose a ferroptosis-inducing therapeutic strategy for LKB1-deficient cancers.


Assuntos
Proteínas Quinases Ativadas por AMP , Complexo I de Transporte de Elétrons , Ferroptose , Fosfolipídeo Hidroperóxido Glutationa Peroxidase , Proteínas Serina-Treonina Quinases , Ferroptose/genética , Ferroptose/efeitos dos fármacos , Animais , Humanos , Proteínas Quinases Ativadas por AMP/metabolismo , Proteínas Quinases Ativadas por AMP/genética , Complexo I de Transporte de Elétrons/metabolismo , Complexo I de Transporte de Elétrons/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Serina-Treonina Quinases/genética , Camundongos , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/metabolismo , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/genética , Linhagem Celular Tumoral , Neoplasias/genética , Neoplasias/patologia , Neoplasias/metabolismo , Neoplasias/tratamento farmacológico , Quinases Proteína-Quinases Ativadas por AMP/genética , Mitocôndrias/metabolismo , Mitocôndrias/genética , Mitocôndrias/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto , Transdução de Sinais , Feminino
2.
J Cell Physiol ; 239(3): e31068, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37357526

RESUMO

N6-methyladenosine (m6 A) is one of the main epitranscriptomic modifications that accelerates the progression of malignant tumors by modifying RNA. Methyltransferase-like 16 (METTL16) is a newly identified methyltransferase that has been found to play an important oncogenic role in a few malignancies; however, its function in osteosarcoma (OS) remains unclear. In this study, METTL16 was found to be upregulated in OS tissues, and associated with poor prognosis in OS patients. Functionally, METTL16 substantially promoted OS cell proliferation, migration, and invasion in vitro and OS growth in vivo. Mechanistically, vacuolar protein sorting protein 33b (VPS33B) was identified as the downstream target of METTL16, which induced m6 A modification of VPS33B and impaired the stability of the VPS33B transcript, thereby degrading VPS33B. In addition, VPS33B was found to be downregulated in OS tissues, VPS33B knockdown markedly attenuated shMETTL16-mediated inhibition on OS progression. Finally, METTL16/VPS33B might facilitate OS progression through PI3K/AKT pathway. In summary, this study revealed an important role for the METTL16-mediated m6 A modification in OS progression, implying it as a promising target for OS treatment.


Assuntos
Adenosina , Neoplasias Ósseas , Metiltransferases , Osteossarcoma , Fosfatidilinositol 3-Quinases , Proteínas de Transporte Vesicular , Humanos , Neoplasias Ósseas/genética , Neoplasias Ósseas/patologia , Metiltransferases/genética , Metiltransferases/metabolismo , Osteossarcoma/genética , Osteossarcoma/patologia , Fosfatidilinositol 3-Quinases/metabolismo , Transporte Proteico , Proteínas de Transporte Vesicular/genética , Proteínas de Transporte Vesicular/metabolismo , Adenosina/análogos & derivados , Adenosina/metabolismo , Linhagem Celular Tumoral
3.
Chembiochem ; 25(13): e202400227, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38700476

RESUMO

Biomarkers are crucial physiological and pathological indicators in the host. Over the years, numerous detection methods have been developed for biomarkers, given their significant potential in various biological and biomedical applications. Among these, the detection system based on functionalized DNA origami has emerged as a promising approach due to its precise control over sensing modules, enabling sensitive, specific, and programmable biomarker detection. We summarize the advancements in biomarker detection using functionalized DNA origami, focusing on strategies for DNA origami functionalization, mechanisms of biomarker recognition, and applications in disease diagnosis and monitoring. These applications are organized into sections based on the type of biomarkers - nucleic acids, proteins, small molecules, and ions - and concludes with a discussion on the advantages and challenges associated with using functionalized DNA origami systems for biomarker detection.


Assuntos
Biomarcadores , DNA , DNA/química , DNA/análise , Biomarcadores/análise , Humanos , Técnicas Biossensoriais , Nanoestruturas/química , Proteínas/análise , Proteínas/química , Conformação de Ácido Nucleico
4.
Nat Mater ; 22(12): 1470-1477, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38012388

RESUMO

Three-dimensional (3D) hetero-integration technology is poised to revolutionize the field of electronics by stacking functional layers vertically, thereby creating novel 3D circuity architectures with high integration density and unparalleled multifunctionality. However, the conventional 3D integration technique involves complex wafer processing and intricate interlayer wiring. Here we demonstrate monolithic 3D integration of two-dimensional, material-based artificial intelligence (AI)-processing hardware with ultimate integrability and multifunctionality. A total of six layers of transistor and memristor arrays were vertically integrated into a 3D nanosystem to perform AI tasks, by peeling and stacking of AI processing layers made from bottom-up synthesized two-dimensional materials. This fully monolithic-3D-integrated AI system substantially reduces processing time, voltage drops, latency and footprint due to its densely packed AI processing layers with dense interlayer connectivity. The successful demonstration of this monolithic-3D-integrated AI system will not only provide a material-level solution for hetero-integration of electronics, but also pave the way for unprecedented multifunctional computing hardware with ultimate parallelism.

5.
Mol Biol Rep ; 51(1): 680, 2024 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-38796595

RESUMO

Menstrual blood-derived endometrial stem cells (MenSCs) have attracted increasing interest due to their excellent safety, and lack of ethical dilemma as well as their ability to be periodically obtained in a noninvasive manner. However, although preclinical research as shown the therapeutic potential of MenSCs in several diseases, their poor cell survival and low engraftment at disease sites reduce their clinical efficacy. Flotillins (including Flot1 and Flot2) are implicated in various cellular processes, such as vesicular trafficking, signal transduction, cell proliferation, migration and apoptosis. In this study, we aimed to determine the effects of Flotillins on MenSCs survival, proliferation and migration. Our experimental results show that MenSCs were modified to overexpress Flot1 and/or Flot2 without altering their intrinsic characteristics. Flot1 and Flot2 co-overexpression promoted MenSC viability and proliferation capacity. Moreover, Flot1 or Flot2 overexpression significantly promoted the migration and inhibited the apoptosis of MenSCs compared with the negative control group, and these effects were stronger in the Flot1 and Flot2 gene co-overexpression group. However, these effects were significantly reversed after Flot1 and/or Flot2 knockdown. In conclusion, our results indicate that Flot1 and Flot2 overexpression in MenSCs improved their proliferation and migration and inhibited their apoptosis, and this might be an effective approach to improve the efficiency of cell-based therapies.


Assuntos
Apoptose , Movimento Celular , Proliferação de Células , Sobrevivência Celular , Proteínas de Membrana , Humanos , Proteínas de Membrana/metabolismo , Proteínas de Membrana/genética , Feminino , Endométrio/citologia , Endométrio/metabolismo , Células-Tronco/metabolismo , Células-Tronco/citologia , Células Cultivadas , Transdução de Sinais
6.
Phys Chem Chem Phys ; 26(5): 3890-3896, 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38230515

RESUMO

With the development of advanced micro/nanoscale technologies, two-dimensional materials have emerged from laboratories and have been applied in practice. To investigate the mechanisms of solid-liquid interactions in potential applications, molecular dynamics simulations are employed to study the flow behavior of n-dodecane (C12) molecules confined in black phosphorus (BP) nanochannels. Under the same external conditions, a significant difference in the velocity profiles of fluid molecules is observed when flowing along the armchair and zigzag directions of the BP walls. The average velocity of C12 molecules flowing along the zigzag direction is 9-fold higher than that along the armchair direction. The friction factor at the interface between C12 molecules and BP nanochannels and the orientations of C12 molecules near the BP walls are analyzed to explain the differences in velocity profiles under various flow directions, external driving forces, and nanochannel widths. The result shows that most C12 molecules are oriented parallel to the flow direction along the zigzag direction, leading to a relatively smaller friction factor hence a higher average velocity. In contrast, along the armchair direction, most C12 molecules are oriented perpendicular to the flow direction, leading to a relatively larger friction factor and thus a lower average velocity. This work provides important insights into understanding the anisotropic liquid flows in nanochannels.

7.
Environ Res ; 248: 118393, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38309564

RESUMO

Soil solution pH and dissolved organic carbon (DOC) influence cadmium (Cd) uptake by hyperaccumulators but their tradeoff in calcareous soils is unclear. This study investigated the mechanisms of Solanum nigrum L. and Solanum alatum Moench in calcareous soil using a combination of concentration gradient experiments (0.6-100 mg Cd kg-1) and soil solution composition analysis. The results showed that the soil solution pH of S. nigrum remained stable despite Cd stress. On average, the soil solution pH of S. alatum was 0.23 units higher than that of S. nigrum, although pH decreased significantly under high Cd stress. In addition, the concentrations of potassium (K) and calcium (Ca) in the soil solution of S. nigrum increased and decreased under low and high levels of Cd stress, respectively. In S. alatum, the K and Ca concentrations in the soil solution generally increased with increasing Cd stress levels. Moreover, the level of DOC in the soil solution of both plants was higher under Cd stress compared to the control, and a gradually increasing trend with Cd stress level was observed in S. alatum. Consequently, the bioconcentration factors of the roots (2.62-19.35) and shoots (1.20-9.59) of both plants were >1, while the translocation factors were <1, showing an obstacle of Solanum hyperaccumulators in transferring Cd into their aboveground parts. Redundancy analysis revealed that the Cd concentration in S. nigrum roots was significantly negatively correlated with the soil solutions of K and Ca. In contrast, Cd concentrations in S. alatum roots and shoots were significantly positively correlated with soil solution DOC, K, and Ca but negatively correlated with pH. Our results suggest that calcareous soil neutralizes the acidity of released protons but does not affect cation exchange, inhibiting DOC in assisting the translocation of Cd within plants.


Assuntos
Poluentes do Solo , Solanum nigrum , Solanum , Cádmio/análise , Matéria Orgânica Dissolvida , Solo/química , Biodegradação Ambiental , Poluentes do Solo/análise , Minerais/análise , Íons/análise , Raízes de Plantas/química , Cálcio/análise , Concentração de Íons de Hidrogênio
8.
Cancer Sci ; 114(4): 1582-1595, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36632741

RESUMO

Cervical squamous cell carcinoma (CSCC) is one of the leading causes of cancer death in women worldwide. Patients with advanced cervical carcinoma always have a poor prognosis once resistant to cisplatin due to the lack of effective treatment. It is urgent to investigate the molecular mechanisms of cisplatin resistance. Circular RNAs (circRNAs) are known to exert their regulatory functions in a series of malignancies. However, their effects on CSCC remain to be elucidated. Here, we found that cytoplasmic circARHGAP5, derived from second and third exons of the ARHGAP5 gene, was downregulated in cisplatin-resistant tissues compared with normal cervix tissues and untreated cervical cancer tissues. In addition, experiments from overexpression/knockdown cell lines revealed that circARHGAP5 could inhibit cisplatin-mediated cell apoptosis in CSCC cells both in vitro and in vivo. Mechanistically, circARHGAP5 interacted with AU-rich element RNA-binding protein (AUF1) directly. Overexpression of AUF1 could also inhibit cell apoptosis mediated by cisplatin. Furthermore, we detected the potential targets of AUF1 related to the apoptotic pathway and found that bcl-2-like protein 11 (BIM) was not only negatively regulated by AUF1 but positively regulated by circARHGAP5, which indicated that BIM mRNA might be degraded by AUF1 and thereby inhibited tumor cell apoptosis. Collectively, our data indicated that circARHGAP5 directly bound to AUF1 and prevented AUF1 from interacting with BIM mRNA, thereby playing a pivotal role in cisplatin resistance in CSCC. Our study provides insights into overcoming cancer resistance to cisplatin treatment.


Assuntos
Carcinoma de Células Escamosas , Ribonucleoproteína Nuclear Heterogênea D0 , RNA Circular , Neoplasias do Colo do Útero , Feminino , Humanos , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Cisplatino/farmacologia , Proteínas Ativadoras de GTPase/genética , Ribonucleoproteína Nuclear Heterogênea D0/metabolismo , RNA Circular/genética , RNA Mensageiro/metabolismo , Neoplasias do Colo do Útero/tratamento farmacológico , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/patologia
9.
Opt Express ; 31(21): 34963-34979, 2023 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-37859240

RESUMO

The paper presents a 170 GHz quasi-optical sub-harmonic mixer with a 3D-printed back-to-back lenses packaging. The quasi-optical mixer is comprised by a pair of antiparallel GaAs Schottky diodes, a patch antenna for receiving local oscillator (LO) pump signal, a symmetric-slit patch antenna for receiving radio frequency (RF) signal, dual 3D-printed lenses and a matching network. The quasi-optical mixer with a pair of antiparallel GaAs Schottky diodes is designed on a multilayer build-up printed circuit board (PCB) utilizing commercially low-cost and high-density interconnect (HDI) technology. The LO and RF antennas are placed on the front and back of the multilayer build-up substrate, respectively, thus significantly simplifying the quasi-optical design. Furthermore, dual 3D-printed lenses placed back-to-back are proposed for LO and RF antennas radiation gain enhancement and mechanical robustness. Additionally, the buried planar reflectors in the substrate maintain effective radiation isolation between the antennas. For facilitating coupling efficiency of signal power into the Schottky diodes and signal isolation between the LO pump signal and RF signal, a compact matching network with low-loss quasi-coaxial via transition structure is integrated in the mixer circuit. The measured single-sideband conversion loss is from 11.3 to 15.4 dB in an operation range of 160 to 180 GHz. The measured radiation patterns agree well with the simulated results.

10.
Anal Bioanal Chem ; 415(12): 2249-2260, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36920495

RESUMO

In this work, we design and synthesize 2,2'-(7,9-dimethyl-2,4,6,8-tetraoxo-6,7,8,9-tetrahydropyrimido[5,4-g]pteridine-1,3(2H,4H)-diyl)bis(N,N-bis(2-chloroethyl)acetamide) (PT-MCA) as a novel DNA intercalator and potential antitumor agent. Electrochemical analysis reveals the redox process of PT-MCA on the electrode surface. The bioelectrochemical sensors are obtained by modifying the surface of GCE with calf thymus DNA (ctDNA), poly (dG), poly (dA), and G-quadruplex, respectively. The DNA oxidative damage induced by PT-MCA is investigated by comparing the peak intensity change of dGuo and dAdo and monitoring the peaks of the oxidation products of guanine and/or adenine (8-oxoGua and/or 2,8-oxoAde). UV-vis absorption and fluorescence spectra and gel electrophoresis are further employed to understand the intercalation of PT-MCA into DNA base pairs. Moreover, PT-MCA is proved to exhibit stronger anti-proliferation activity than mitoxantrone against both 4T1 and B16-F10 cancer cells. At last, the oxidative damage of PT-MCA toward ctDNA is not interfered by the coexistence of ions and also can be detected in real serums.


Assuntos
Antineoplásicos , Pteridinas , DNA/genética , Antineoplásicos/farmacologia , Adenina , Estresse Oxidativo , Dano ao DNA
11.
Appl Opt ; 62(20): 5399-5408, 2023 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-37706856

RESUMO

The terahertz frequency modulation continuous-wave (THz FMCW) imaging technology has been widely used in non-destructive testing applications. However, THz FMCW real-aperture radar usually has a small depth of field and poor lateral resolution, thus restricting the high-precision imaging application. This paper proposes a 150-220 GHz FMCW Bessel beam imaging system, effectively doubling the depth of field and unifying the lateral resolution compared to the Gaussian beam quasi-optical system. Moreover, a THz image restoration algorithm based on local gradients and convolution kernel priors is proposed to eliminate further the convolution effect introduced by the Bessel beam, thereby enhancing the lateral resolution to 2 mm. It effectively improves the image under-restoration or over-restoration caused by the mismatch between the ideal and actual point spread function. The imaging results of the resolution test target and semiconductor device verify the advantages of the proposed system and algorithm.

12.
Sleep Breath ; 27(6): 2509-2516, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37097553

RESUMO

PURPOSE: To examine whether or not folic acid (FA) supplementation may modify the relationships between duration or quality of sleep and gestational diabetes mellitus (GDM) risk. METHODS: In a case-control study of patients with GDM and controls, mothers were interviewed face-to-face at enrollment. The Pittsburgh Sleep Quality Scale was used to assess duration and quality of sleep during early pregnancy, and information on FA supplementation and covariates was obtained using a semiquantitative questionnaire. RESULTS: Among 396 patients with GDM and 904 controls, GDM risk increased by 328% and 148% among women with short (< 7 h) and long (≥ 9 h) sleep durations, respectively, compared to those averaging 7-8.9 h sleep. Mothers with poor sleep quality increased their GDM risk by an average of 75% (all p < 0.05). The effect of short sleep duration on GDM risk was much weaker among women with adequate FA supplementation (taking supplements containing ≥ 0.4 mg FA daily for each day of the first three months of pregnancy) than that among women with inadequate FA supplementation, with a p-value for interaction = 0.003. There were no significant effects of FA on links among long duration and poor quality of sleep with GDM risk. CONCLUSIONS: Sleep duration and quality in early gestation were related to increased GDM risks. FA supplementation may reduce GDM risk associated with short sleep duration.


Assuntos
Diabetes Gestacional , Transtornos do Sono-Vigília , Gravidez , Feminino , Humanos , Diabetes Gestacional/prevenção & controle , Duração do Sono , Estudos de Casos e Controles , Sono , Suplementos Nutricionais , Ácido Fólico/uso terapêutico
13.
Data Knowl Eng ; 146: 102193, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37251597

RESUMO

The outbreak of the COVID-19 epidemic has had a huge impact on a global scale and its impact has covered almost all human industries. The Chinese government enacted a series of policies to restrict the transportation industry in order to slow the spread of the COVID-19 virus in early 2020. With the gradual control of the COVID-19 epidemic and the reduction of confirmed cases, the Chinese transportation industry has gradually recovered. The traffic revitalization index is the main indicator for evaluating the degree of recovery of the urban transportation industry after being affected by the COVID-19 epidemic. The prediction research of traffic revitalization index can help the relevant government departments to know the state of urban traffic from the macro level and formulate relevant policies. Therefore, this study proposes a deep spatial-temporal prediction model based on tree structure for the traffic revitalization index. The model mainly includes spatial convolution module, temporal convolution module and matrix data fusion module. The spatial convolution module builds a tree convolution process based on the tree structure that can contain directional features and hierarchical features of urban nodes. The temporal convolution module constructs a deep network for capturing temporal dependent features of the data in the multi-layer residual structure. The matrix data fusion module can perform multi-scale fusion of COVID-19 epidemic data and traffic revitalization index data to further improve the prediction effect of the model. In this study, experimental comparisons between our model and multiple baseline models are conducted on real datasets. The experimental results show that our model has an average improvement of 21%, 18%, and 23% in MAE, RMSE and MAPE indicators, respectively.

14.
Opt Express ; 30(6): 9814-9822, 2022 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-35299396

RESUMO

The terahertz frequency modulated continuous wave (THz FMCW) imaging has proved to be a novel nondestructive testing (NDT) technology for non-metal materials, and the large bandwidth is usually required to meet high range resolution demands in many applications such as multilayer sample under test (SUT). However, broadband THz hardware is difficult to design. In this paper, an ultra-wideband THz FMCW generation method is proposed, which provides frequency modulation bandwidths of up to 386 GHz by time-division multiplexing. Furthermore, an ultra-wideband signal fusion algorithm (USFA) is also proposed and significantly improves the range resolution to 0.46 mm in air. Results from the artificially constructed multilayer structure demonstrate the superiority and effectiveness of our method quantitatively.

15.
Xenotransplantation ; 29(1): e12720, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34850455

RESUMO

Islet transplantation is a potential treatment option for certain patients with type 1 diabetes; however, it still faces barriers to widespread use, including the lack of tools to monitor islet grafts post-transplantation. This study investigates whether labeling neonatal porcine islets (NPI) with polyvinylpyrrolidone-coated superparamagnetic iron oxide nanoparticles (PVP-SPIO) affects their function, and whether this nanoparticle can be utilized to monitor NPI xenografts with magnetic resonance imaging (MRI) in a mouse model. In vitro, PVP-SPIO-labeled NPI in an agarose gel was visualized clearly by MRI. PVP-SPIO-labeled islets were then transplanted under the kidney capsules of immunodeficient nondiabetic and diabetic mice. All diabetic mice that received transplantation of PVP-SPIO-labeled islets reached normoglycemia. Grafts appeared as hypo-intense areas on MRI and were distinguishable from the surrounding tissues. Following injection of spleen cells from immunocompetent mice, normoglycemic recipient mice became diabetic and islet grafts showed an increase in volume, accompanied by a mixed signal on MRI. Overall, this study demonstrates that PVP-SPIO did not affect the function of NPI that PVP-SPIO-labeled islets were easily seen on MRI, and changes in MRI signals following rejection suggest a potential use of PVP-SPIO-labeled islets to monitor graft viability.


Assuntos
Diabetes Mellitus Experimental , Transplante das Ilhotas Pancreáticas , Ilhotas Pancreáticas , Animais , Humanos , Transplante das Ilhotas Pancreáticas/métodos , Nanopartículas Magnéticas de Óxido de Ferro , Imageamento por Ressonância Magnética/métodos , Camundongos , Povidona , Suínos , Transplante Heterólogo/métodos
16.
Org Biomol Chem ; 20(14): 2831-2842, 2022 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-35294516

RESUMO

Trifluoromethylation reaction is one of the significant and practical organic chemical reactions, and the design and discovery of novel trifluoromethylation reagents have been attracting more and more attention. Trifluoromethyl-substituted organic hydride compounds (XH) have the potential to be novel trifluoromethylation reagents in organic synthesis due to the favorable tendency of XH˙+ releasing ˙CF3 to form stable aromatic structures in terms of thermodynamics. The key elementary step of the trifluoromethylation is the radical cation (XH˙+) generation by catalysis or single-electron activation releasing ˙CF3 to form a stable aromatic structure, which also provides the thermodynamic driving force of the chemical process. In this work, 47 new trifluoromethylation reagent candidates of XHs were designed and calculated for the Gibbs free energy and activation free energy [ΔG‡RD(XH˙+)] of XH˙+ releasing ˙CF3 using the density functional theory (DFT) method, in order to quantitatively measure the reactivity of XHs as trifluoromethylation reagents, and to establish the molecular library as well as reactivity database of novel trifluoromethylation reagents for synthetic chemists. According to the and ΔG‡RD(XH˙+) values, all the XHs can be reasonably divided into 3 classes, including class 1 (excellent trifluoromethylation reagents), class 2 (potential trifluoromethylation reagents) and class 3 (not trifluoromethylation reagents). To our delight, 15 XHs with a 1,4-dihydropyridine structure and 3 XHs with a 3,4-dihydropyrimidin-2-one structure are identified to be novel excellent and potential trifluoromethylation reagents, respectively, according to their reactivity data. The relationship between the structural features, including methylation, heteroatom, substituents, conjugated structure and so on, and the reactivity of XHs as trifluoromethylation reagents are also discussed in this work. The computation results indicate that trifluoromethyl-substituted 1,4-dihydropyridine compounds and 3,4-dihydropyrimidin-2-one analogues could be possible trifluoromethylation reagents in organic synthesis. This work may provide the theoretical basis and references for discovering organic hydride compounds as novel reagents for trifluoromethylation or other alkylation reactions.


Assuntos
Modelos Teóricos , Compostos Orgânicos , Catálise , Indicadores e Reagentes , Estrutura Molecular
17.
Bioorg Chem ; 129: 106182, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36341739

RESUMO

Tumor-targeted near-infrared (NIR) fluorescence imaging by using NIR fluorescent probes has attracted extensive attentions in the field of tumor imaging and is becoming an attractive strategy for early cancer diagnosis and surgical guidance for the past few decades. Especially, due to the high affinity and low toxicity, the peptide-based NIR fluorescent probes play an important role in the field of tumor-targeted imaging and therapy. Extensive attempts have been made to develop a set of nontoxic and efficacious "always-on" peptide-based NIR fluorescent probes. In this review, we give a comprehensive analysis of the "always-on" peptide-based NIR fluorescent probes for tumor-targeting for the past 5 years, highlighting the design strategy, chemical synthesis, therapeutical applications, spectroscopic and pharmacological characterization, as well as the multifaceted roles of peptides. A comprehensive understanding of the tumor-targeted, "always-on" peptide-based NIR fluorescent probes will increase our knowledge of cancer diagnosis and benefit clinical cancer therapeutics.


Assuntos
Corantes Fluorescentes , Neoplasias , Humanos , Corantes Fluorescentes/química , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Imagem Óptica/métodos , Neoplasias/diagnóstico por imagem , Peptídeos/química
18.
Appl Opt ; 61(24): 7189-7196, 2022 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-36256339

RESUMO

Terahertz frequency modulation continuous wave (THz FMCW) imaging technology has been widely used in non-destructive testing (NDT) applications of non-metallic materials. However, THz FMCW real-aperture radar usually has a narrow bandwidth and small depth of field, thus restricting the application of THz FMCW NDT. In this paper, a wideband THz signal (220-500 GHz) generation method is proposed by time-division multiplexing. Moreover, a dual-band quasi-optical design with a large depth of field is proposed based on the THz Bessel beam, and a high-quality range profile is obtained. Especially, a signal fusion extended Fourier analysis algorithm without prior knowledge is proposed to further enhance the range profile accuracy, which improves the range resolution to 0.28 mm (λ/3, center frequency 360 GHz). The effectiveness and advantages of the proposed system are verified by artificially constructing composite materials.

19.
Biochem Biophys Res Commun ; 581: 38-45, 2021 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-34653677

RESUMO

A detrimental role of the receptor for the advanced glycation end product (RAGE) has been identified in the immune response, and various pathological conditions and its V and C1 domains in the extracellular region of RAGE are believed to be the main ligand-binding domains. Consequently, specific inhibitors targeting those domains could be of clinical value in fighting against the pathological condition associated with RAGE over-activation. Single-domain antibodies, also called nanobodies (Nbs), are antibody fragments engineered from the heavy-chain only antibodies found in camelids, which offer a range of advantages in therapy. In this study, we report the development and characterization of the V-C1 domain-specific Nbs. Three Nbs (3CNB, 4BNB, and 5ENB) targeting V-C1 domain of human RAGE were isolated from an immunized alpaca using a phage display. All of these Nbs revealed high thermostability. 3CNB, 4BNB, and 5ENB bind to V-C1 domain with a dissociation constant (KD) of 27.25, 39.37, and 47.85 nM, respectively, using Isothermal Titration Calorimetry (ITC). After homodimerization using human IgG1-Fc fusion, their binding affinity improved to 0.55, 0.62, and 0.41 nM, respectively, using Surface Plasmon Resonance (SPR). Flow cytometry showed all the Fc fusions Nbs can bind to human RAGE expressed on the cell surface. Competitive ELISA further confirmed their V-C1-hS100B blocking ability in solution, providing insights into the applicability of Nbs in treating RAGE-associated diseases.


Assuntos
Produtos Finais de Glicação Avançada/química , Fragmentos Fc das Imunoglobulinas/química , Imunoglobulina G/química , Receptor para Produtos Finais de Glicação Avançada/química , Proteínas Recombinantes de Fusão/química , Anticorpos de Domínio Único/biossíntese , Sequência de Aminoácidos , Animais , Sítios de Ligação , Camelídeos Americanos , Clonagem Molecular , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Produtos Finais de Glicação Avançada/genética , Produtos Finais de Glicação Avançada/imunologia , Células HEK293 , Humanos , Fragmentos Fc das Imunoglobulinas/genética , Fragmentos Fc das Imunoglobulinas/imunologia , Imunoglobulina G/genética , Imunoglobulina G/imunologia , Biblioteca de Peptídeos , Ligação Proteica , Domínios Proteicos , Domínios e Motivos de Interação entre Proteínas , Multimerização Proteica , Receptor para Produtos Finais de Glicação Avançada/antagonistas & inibidores , Receptor para Produtos Finais de Glicação Avançada/genética , Receptor para Produtos Finais de Glicação Avançada/imunologia , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Anticorpos de Domínio Único/química , Anticorpos de Domínio Único/isolamento & purificação
20.
Appl Opt ; 60(22): 6400-6408, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-34612874

RESUMO

Terahertz (THz) testing, by the frequency modulated continuous wave (FMCW) system, is often hampered by the limited range resolution. Thus, in this paper, a software method is proposed to reconstruct the range profile, yielding significant improvements in range resolution and in signal parameter extraction. Specifically, the multiple signal characterization algorithm is first introduced to indicate a higher-resolution range profile qualitatively and to acquire the echoes' initial values. Then, multiple Gaussian functions are applied to fit those echoes in the whole original range profile and to accurately extract the parameters, including the amplitude, range, and width, of each echo. Finally, with these parameters, the range profile can be more precisely and flexibly reconstructed, facilitating the following detection procedure to a great extent. Both the simulated and the real THz data, acquired by a 150-220 GHz FMCW imager, have been used to demonstrate the superiority and effectiveness of our method, qualitatively and quantitatively.

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