Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 91
Filtrar
1.
Org Biomol Chem ; 22(26): 5401-5405, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38874577

RESUMO

A stable and practical electrochemical method was developed to promote the thio-Michael addition of N-substituted maleimides to various thiols in an aqueous medium. This protocol was found to be excellent in terms of facile scale-up, oxidant- and catalyst-free conditions, broad substrate scopes, good functional group tolerance, and easily available substrates. Notably, a plausible reaction mechanism was derived from the results of a series of control experiments and CV studies, which indicated that a radical pathway might speed up the thio-Michael addition under constant current.

2.
Eur J Med Chem ; 272: 116478, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38718624

RESUMO

Metallodrugs exhibiting distinct mechanisms of action compared with cisplatin hold promise for overcoming cisplatin resistance and improving the efficacy of anticancer drugs. In this study, a new series of rhodium (Rh)(III) complexes containing tris(triphenylphosphine)rhodium(I) chloride [(TPP)3RhCl] (TPP = triphenylphosphine, TPP=O = triphenylphosphine oxide) and 8-hydroxyquinoline derivatives (H-XR1-H-XR4), namely [Rh(XR1)2(TPP)Cl]·(TPP=O) (Yulin Normal University-1a [YNU-1a]), [Rh(XR2)2(TPP)Cl] (YNU-1b), [Rh(XR3)2(TPP)Cl] (YNU-1c), and [Rh(XR4)2(TPP)Cl] (YNU-1d), was synthesized and characterized via X-ray diffraction, mass spectrometry and IR. The cytotoxicity of the compounds YNU-1a-YNU-1d in Hep-G2 and HCC1806 human cancer cell lines and normal HL-7702 cell line was evaluated. YNU-1c exhibited cytotoxicity and selectivity in HCC1806 cells (IC50 = 0.13 ± 0.06 µM, selectivity factor (SF) = 384.6). The compounds YNU-1b and YNU-1c, which were selected for mechanistic studies, induced the activation of apoptotic pathways and mitophagy. In addition, these compounds released cytochrome c, cleaved caspase-3/pro-caspase-3 and downregulated the levels of mitochondrial respiratory chain complexes I/IV (M1 and M4) and ATP. The compound YNU-1c, which was selected for in vivo experiments, exhibited tumor growth inhibition (58.9 %). Importantly, hematoxylin and eosin staining and TUNEL revealed that HCC1806 tumor tissues exhibited significant apoptotic characteristics. YNU-1a-YNU-1d compounds are promising drug candidates that can be used to overcome cisplatin resistance.


Assuntos
Antineoplásicos , Proliferação de Células , Complexos de Coordenação , Ensaios de Seleção de Medicamentos Antitumorais , Mitofagia , Oxiquinolina , Ródio , Humanos , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Ródio/química , Ródio/farmacologia , Oxiquinolina/química , Oxiquinolina/farmacologia , Oxiquinolina/síntese química , Complexos de Coordenação/farmacologia , Complexos de Coordenação/química , Complexos de Coordenação/síntese química , Animais , Relação Estrutura-Atividade , Proliferação de Células/efeitos dos fármacos , Mitofagia/efeitos dos fármacos , Estrutura Molecular , Compostos Organofosforados/farmacologia , Compostos Organofosforados/química , Compostos Organofosforados/síntese química , Relação Dose-Resposta a Droga , Apoptose/efeitos dos fármacos , Camundongos , Linhagem Celular Tumoral
3.
Dalton Trans ; 53(5): 2143-2152, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38189098

RESUMO

Mitophagy, a selective autophagic process, has emerged as a pathway involved in degrading dysfunctional mitochondria. Herein, new platinum(II)-based chemotherapeutics with mitophagy-targeting properties are proposed. Four novel binuclear anticancer Pt(II) complexes with 4'-substituted-2,2':6',2''-terpyridine derivatives (tpy1-tpy4), i.e., [Pt2(tpy1)(DMSO)2Cl4]·CH3OH (tpy1Pt), [Pt(tpy2)Cl][Pt(DMSO)Cl3]·CH3COCH3 (tpy2Pt), [Pt(tpy3)Cl][Pt(DMSO)Cl3] (tpy3Pt), and [Pt(tpy4)Cl]Cl·CH3OH (tpy4Pt), were designed and prepared. Moreover, their potential antitumor mechanism was studied. Tpy1Pt-tpy4Pt exhibited more selective cytotoxicity against cisplatin-resistant SK-OV-3/DDP (SKO3cisR) cancer cells compared with those against ovarian SK-OV-3 (SKO3) cancer cells and normal HL-7702 liver (H702) cells. This selective cytotoxicity of Tpy1Pt-tpy4Pt was better than that of its ligands (i.e., tpy1-tpy4), the clinical drug cisplatin, and cis-Pt(DMSO)2Cl2. The results of various experiments indicated that tpy1Pt and tpy2Pt kill SKO3cisR cancer cells via a mitophagy pathway, which involves the disruption of the mitophagy-related protein expression, dissipation of the mitochondrial membrane potential, elevation of the [Ca2+] and reactive oxygen species levels, promotion of mitochondrial DNA damage, and reduction in the adenosine triphosphate and mitochondrial respiratory chain levels. Furthermore, in vivo experiments indicated that the dinuclear anticancer Pt(II) coordination compound (tpy1Pt) has remarkable therapeutic efficiency (ca. 52.4%) and almost no toxicity. Therefore, the new 4'-substituted-2,2':6',2''-terpyridine Pt(II) coordination compound (tpy1Pt) is a potential candidate for next-generation mitophagy-targeting dinuclear Pt(II)-based anticancer drugs.


Assuntos
Antineoplásicos , Cisplatino , Cisplatino/farmacologia , Platina/farmacologia , Dimetil Sulfóxido , Linhagem Celular Tumoral , Compostos Organoplatínicos/farmacologia , Antineoplásicos/farmacologia , Apoptose
4.
Eur Heart J ; 45(9): 669-684, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38085922

RESUMO

BACKGROUND AND AIMS: Survivors of acute coronary syndromes face an elevated risk of recurrent atherosclerosis-related vascular events despite advanced medical treatments. The underlying causes remain unclear. This study aims to investigate whether myocardial infarction (MI)-induced trained immunity in monocytes could sustain proatherogenic traits and expedite atherosclerosis. METHODS: Apolipoprotein-E deficient (ApoE-/-) mice and adoptive bone marrow transfer chimeric mice underwent MI or myocardial ischaemia-reperfusion (IR). A subsequent 12-week high-fat diet (HFD) regimen was implemented to elucidate the mechanism behind monocyte trained immunity. In addition, classical monocytes were analysed by flow cytometry in the blood of enrolled patients. RESULTS: In MI and IR mice, blood monocytes and bone marrow-derived macrophages exhibited elevated spleen tyrosine kinase (SYK), lysine methyltransferase 5A (KMT5A), and CCHC-type zinc finger nucleic acid-binding protein (CNBP) expression upon exposure to a HFD or oxidized LDL (oxLDL) stimulation. MI-induced trained immunity was transmissible by transplantation of bone marrow to accelerate atherosclerosis in naive recipients. KMT5A specifically recruited monomethylation of Lys20 of histone H4 (H4K20me) to the gene body of SYK and synergistically transactivated SYK with CNBP. In vivo small interfering RNA (siRNA) inhibition of KMT5A or CNBP potentially slowed post-MI atherosclerosis. Sympathetic denervation with 6-hydroxydopamine reduced atherosclerosis and inflammation after MI. Classical monocytes from ST-elevation MI (STEMI) patients with advanced coronary lesions expressed higher SYK and KMT5A gene levels. CONCLUSIONS: The findings underscore the crucial role of monocyte trained immunity in accelerated atherosclerosis after MI, implying that SYK in blood classical monocytes may serve as a predictive factor for the progression of atherosclerosis in STEMI patients.


Assuntos
Aterosclerose , Infarto do Miocárdio , Infarto do Miocárdio com Supradesnível do Segmento ST , Humanos , Animais , Camundongos , Monócitos , Imunidade Treinada
5.
J Colloid Interface Sci ; 658: 450-458, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38118191

RESUMO

Covalent organic frameworks (COFs) have a broad prospect to be used as a photocatalytic platform to convert solar energy into valuable chemicals due to their tunable structures and rich active catalytic sites. However, constructing COFs with tuned sp2-carbon donor-acceptor moiety remains an enormous challenge. Herein, we synthesized two new fully π-conjugated cyano-ethylene-linked COFs containing benzotrithiophene as functional group by Knoevenagel polycondensation reaction. The accetpor 2,2'-bipyridine unit in BTT-BpyDAN-COF skeleton favored the formation of a intermolecular specific electron transport pathway with the donor benzotrithiophene, and thereby promoted charge separation and transfer efficiency. Specifically, a donor-acceptor (D-A) type BTT-BpyDAN-COF exhibited high hydrogen evolution rate of 10.1 mmol g-1h-1 and an excellent apparent quantum efficiency of 4.83 % under visible light irradiation.

6.
J Neurol Surg B Skull Base ; 84(6): 609-615, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37854532

RESUMO

Objectives Primary frontal sinus malignancies (FSMs) are the rarest sinonasal cancers. This study aimed to determine clinicopathologic characteristics of primary FSMs and provide long-term survival outcomes. Design This study is a retrospective review. Setting The study was conducted at a tertiary medical center. Participants Patients who participated in this study were diagnosed with primary FSMs. Main Outcome Measures Median survival time is the primary outcome measure of this study. Results In this series, the median age was 48 years (30-53 years) and all patients were male. There were five cases with squamous cell carcinoma and one with osteosarcoma. All cases presented with locally advanced disease without regional lymphatic metastasis, including five cases of stage III and one case of stage II. The two most common pathways of tumor invasion were as follows: local tumor broke posteriorly through bone wall and invaded dura mater, followed by frontal lobe; local tumor infiltrated downward through the floor of frontal sinus into ethmoid sinus, thereafter invaded laterally orbit and orbital contents. All patients received surgery followed by postoperative radiotherapy at the total doses of 50 to 75.95 Gy. Among them, only one patient underwent R0 resection, the rest of patients underwent R1/R2 resection. With a median survival time of 56 months (32-76 months), two patients receiving R1/R2 resection developed treatment failure and died within 5 years, including one case with local recurrence and one with local recurrence, thereafter distant metastasis. Conclusion The majority of FSMs presented with peripherally invasive progression lesions which led to a high ratio of R1/R2 resection. Surgery combined with postoperative radiotherapy might result in satisfactory efficacy.

7.
J Inorg Biochem ; 248: 112361, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37659141

RESUMO

Both ruthenium-containing complexes and 8-quinolinoline compounds have emerged as a potential novel agent for malignant tumor therapy. Here, three triphenylphosphine ruthenium complexes, [Ru(ZW1)(PPh3)2Cl2] (PPh3 = triphenylphosphine) (RuZ1), [Ru(ZW2)(PPh3)2Cl2] (RuZ2) and [Ru(ZW2)2(PPh3)Cl2]·CH2Cl2 (RuZ3) bearing 5,7-dichloro-8-quinolinol (H-ZW1) and 5,7-dichloro-8-hydroxyquinaldine (H-ZW2), have been synthesized, characterized and tested for their anticancer potential. We showed that triphenylphosphine ruthenium complexes RuZ1-RuZ3 impaired the cell viability of ovarian adenocarcinoma cisplatin-resistant SK-OV-3/DDP (SKO3CR) and SK-OV-3 (SKO3) cancer cells with greater selectivity and specificity than cisplatin. In addition, RuZ1-RuZ3 show higher excellent cytotoxicity than cisplatin towards SKO3CR cells, with IC50 values of 9.66 ± 1.08, 4.05 ± 0.67 and 7.18 ± 0.40 µM, respectively, in which the SKO3CR cells was the most sensitive to RuZ1-RuZ3. Depending on the substituent type, the antiproliferative ability of RuZ1-RuZ3 followed the trend: -CH3 > -H. However, RuZ1-RuZ3 have no obvious toxicity to normal cell HL-7702. Besides, RuZ1 and RuZ2 could induce mitophagy related-apoptosis pathways through suppression of mitochondrial membrane potential (ΔΨm), accumulation of [Ca2+] and reactive oxygen species (ROS), and regulation of LC3 II/LC3 I, Beclin-1, P62, FUNDC1, PINK1, Parkin, cleaved-caspase-3, caspase-9 and cytochrome c signaling pathway, and hindering the preparation of mitochondrial respiration complexes I and IV and ATP levels. Mechanistic study revealed that RuZ1 and RuZ2 induce apoptosis in SKO3CR cells via mitophagy related-apoptosis pathways induction and energy (ATP) generation disturbance. Taken together, the studied triphenylphosphine ruthenium complexes RuZ1-RuZ3 are promising chemotherapeutic agents with high effectiveness and low toxicity.


Assuntos
Cisplatino , Rutênio , Cisplatino/farmacologia , Mitofagia , Trifosfato de Adenosina
8.
Org Biomol Chem ; 21(27): 5547-5552, 2023 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-37381748

RESUMO

An efficient electrochemical sulfonylation of amines with sulfonyl hydrazides under exogenous-oxidant-free and catalyst-free conditions in aqueous medium was developed. A wide variety of sulfonamides were prepared via a simple electrochemical process from various cyclic or acyclic secondary amines, as well as more challenging free primary amines with equivalent amount of aryl/heteroaryl hydrazides in air under mild conditions. This protocol was found to be excellent in terms of facile scale-up, and to show great potential in the modification/synthesis of bioactive compounds. The reaction mechanism was investigated by a series of control experiments and CV studies, which indicated that the reaction might have gone through a radical pathway. Also, n-Bu4NBr served both as a supporting electrolyte and a redox agent to yield sulfonyl radical species and sulfonyl cations from sulfonyl hydrazides.

9.
Chem Commun (Camb) ; 59(48): 7302-7320, 2023 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-37221919

RESUMO

The excessive use of traditional fossil fuels has led to energy and environmental pollution problems. Solar-driven hydrogen generation has attracted much attention in recent years owing to its environmental friendliness and economic feasibility. So far, a series of photocatalysts have been advanced. Unfortunately, these photocatalysts face some issues including poor sunlight harvesting ability, weak photo-corrosion resistance, broad band gap, bad stability, inferior hydrogen evolution rate and so on. It just so happens that COFs have emerged to provide an opportunity for settling these issues. Covalent organic frameworks (COFs), a novel family of porous materials with regular porosity and tunable physicochemical structures, have been extensively explored as photocatalysts for hydrogen production. Moreover, their photocatalytic activities are highly structurally dependent. In this review, we mainly focus on the linkage chemistry and disparate strategies for boosting COF-based photocatalytic hydrogen generation performance in detail. The prospects and obstacles confronted in the development of COF-based photocatalysts and proposals to settle dilemmas are also discussed.

10.
Quant Imaging Med Surg ; 13(1): 370-383, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36620155

RESUMO

Background: Respiratory motions may cause artifacts on positron emission tomography (PET) images that degrade image quality and quantification accuracy. This study aimed to evaluate the effect of a respiratory motion-corrected image reconstruction (MCIR) algorithm on image quality and tumor quantification compared with nongated/nonmotion-corrected reconstruction. Methods: We used a phantom consisting of 5 motion spheres immersed in a chamber driven by a motor. The spheres and the background chamber were filled with 18F solution at a sphere-to-background ratio of 5:1. We enrolled 42 and 16 patients undergoing 2-deoxy-2-[18F]fluoro-D-glucose {2-[18F]FDG} and 68Ga-labeled [1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid]-1-Nal3-octreotide {[68Ga]Ga-DOTA-NOC} PET/computed tomography (CT) from whom 74 and 30 lesions were segmented, respectively. Three reconstructions were performed: data-driven gating-based motion correction (DDGMC), external vital signal module-based motion correction (VSMMC), and noncorrection reconstruction. The standardized uptake values (SUVs) and the volume of the spheres and the lesions were measured and compared among the 3 reconstruction groups. The image noise in the liver was measured, and the visual image quality of motion artifacts was scored by radiologists in the patient study. Results: In the phantom study, the spheres' SUVs increased by 26-36%, and the volumes decreased by 35-38% in DDGMC and VSMMC compared with the noncorrection group. In the 2-[18F]FDG PET patient study, the lesions' SUVs had a median increase of 10.87-12.65% while the volumes had a median decrease of 14.88-15.18% in DDGMC and VSMMC compared with those of noncorrection. In the [68Ga]Ga-DOTA-NOC PET patient study, the lesions' SUVs increased by 14.23-15.45%, and the volumes decreased by 19.11-20.94% in DDGMC and VSMMC. The image noise in the liver was equal between the DDGMC, VSMMC, and noncorrection groups. Radiologists found improved image quality in more than 45% of the cases in DDGMC and VSMMC compared with the noncorrection group. There was no statistically significant difference in SUVs, volumes, or visual image quality scores between DDGMC and VSMMC. Conclusions: MCIR improves tumor quantification accuracy and visual image quality by reducing respiratory motion artifacts without compromised image noise performance or elongated acquisition time in 2-[18F]FDG and [68Ga]Ga-DOTA-NOC PET/CT tumor imaging. The performance of DDG-driven MCIR is as good as that of the external device-driven solution.

11.
Artigo em Inglês | MEDLINE | ID: mdl-36011615

RESUMO

With the deepening of population aging in China, chronic diseases are a major public health concern that threatens the life and health of nationals. Mobile health or mHealth can effectively monitor chronic diseases, which holds vital significance to the alleviation of social pressure caused by aging. To patients with chronic diseases, mHealth cannot give full play to its value, only when it is used in the long term. However, there is not yet research exploring mHealth continuance intention from the perspective of elders with chronic diseases. So, this research represents the first attempt to empirically analyze mHealth continuance intention from the perspective of elders with chronic diseases. The purpose of this research is to make up the research gap of the mHealth field and to put forward theoretical and practical implications based on research results. To obtain research data, a questionnaire was conducted. A total of 926 copies were collected online and 527 copies were collected offline. The structural equation model (SEM) was used for data analysis. Research results suggest that confirmation can significantly influence satisfaction, performance expectancy and effort expectancy. Meanwhile, confirmation and performance expectancy can significantly influence satisfaction. Additionally, effort expectancy, performance expectancy, social influence and facilitating conditions can directly and significantly influence continuance intention. Among them, performance expectancy can directly influence continuance intention in the most significant way. This research provides solid evidence for the validity of the integrated model of ECM-ISC and UTAUT in the mHealth field, which can be a theoretical basis for mHealth operators' product R&D.


Assuntos
Intenção , Telemedicina , Idoso , China , Doença Crônica , Humanos , Inquéritos e Questionários
12.
Front Psychol ; 13: 823523, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35774944

RESUMO

As the national awareness of health keeps deepening, online health communities (OHCs) have achieved rapid development. Users' participation is critically important to the sustainable development of OHCs. Nevertheless, users usually lack the motive for participation. Based on the social capital theory, this research examines factors influencing users' participation in OHCs. The purpose of this research is to find out decisive factors that influence users' participation in OHCs, enrich the understanding of users' participation in OHCs, and help OHCs address the issue of sustainable development. The research model was empirically tested using 1277 responses from an online survey conducted in China. Data was analyzed using the structural equation modeling (SEM). We found informational support and emotional support to have significant direct effects over the structural capital, relational capital and cognitive capital of OHCs. Meanwhile, it is observed that relational capital and cognitive capital degree have a significant influence on knowledge acquisition and knowledge contribution of OHCs. For researchers this study provides a basis for further refinement of individual models of users' participation. For practitioners, understanding the social capital is crucial to users' knowledge acquisition and knowledge contribution that achieve high participation in OHCs.

13.
Ying Yong Sheng Tai Xue Bao ; 33(4): 949-956, 2022 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-35543046

RESUMO

We explored the effects of C:N ratio in root exudates of Robinia pseudoacacia plantations on soil nutrient cycling and microbial activity on the Loess Plateau. We collected in-situ soil from the R. pseudoacacia plantations with essentially identical habitat conditions and growing time of 15, 25, 35, and 45 years. By adding root exudates with different C:N ratios (N only, C:N=10, C:N=50, C:N=100, C only) to the soil and using deionized water as a control, we analyzed the effects of C:N ratio of root exudates on the physicochemical properties of elements such as carbon, nitrogen and phosphorus, soil pH, and soil respiration. The results showed that: 1) Organic carbon content was positively correlated with the C:N ratio of root exudates. Soil organic carbon (SOC) decomposition was faster when root exudates C:N=10. Higher C:N ratio of root exudates (C:N=100) could inhibit SOC decomposition, but only C addition had no significant effect on SOC. 2) Different root exudate C:N produced no significant influence on the total nitrogen. The addition of carbon promoted microbial uptake of ammonium nitrogen, while the addition of nitrogen promoted the nitrification of ammonium nitrogen. As the C:N ratio of root exudates increased, soil ammonium nitrogen content decreased. 3) The addition of nitrogen would reduce soil pH and increase soil total phosphorus content. 4) Soil respiration of R. pseudoacacia plantations was positively correlated with the C:N ratio of root exudates. With the increases of C:N ratio, the promoting effect of root exudates on soil respiration at 25 and 35 years R. pseudoacacia plantations was stronger. In conclusion, higher C:N ratio of root exudates will significantly promote the effect on soil respiration of R. pseudoacacia plantations. Our results improved the understan-ding of the root-soil-microbial interactions in forests.


Assuntos
Compostos de Amônio , Robinia , Carbono/análise , China , Exsudatos e Transudatos/química , Nitrogênio/análise , Fósforo , Respiração , Solo/química
14.
J Colloid Interface Sci ; 621: 275-284, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35461142

RESUMO

The high-performance and durable oxygen reduction reaction (ORR) catalyst on air cathode is a key component in assembly of Zn-air batteries. Herein, three-dimensional N-doped ordered mesoporous carbon (3D N-OMC) was first prepared with silica as a template via pyrolysis with assistance of dicyandiamide as a N-doping agent, combined by full adsorption of platinum (II) acetylacetonate (Pt(acac)2) and iron (II) phthalocyanine (FePc) via π-π interactions. After further pyrolysis of the resulting mixture, many PtFe nanoparticles were efficiently incorporated in 3D N-OMC (termed as PtFe@3D N-OMC for simplicity). Control experiments were certificated the important role of the pyrolysis temperature played in this synthesis. The resultant composite synergistically combines advantages of hierarchically accessible surfaces, highly open structure, and well-dispersed PtFe particles, which endow the PtFe@3D N-OMC with onset and half-wave potentials of 0.98 and 0.86 V in alkaline media, respectively, showing appealing catalytic activity for the ORR. Most significantly, the PtFe@3D N-OMC based Zn-air battery has a high power density of 80.57 mW cm-2 and long-term durability (220 h, 660 cycles). This work opens a new avenue for design of high-efficiency and durable ORR electrocatalysts in energy conversion and storage systems.

15.
EJNMMI Phys ; 9(1): 23, 2022 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-35348926

RESUMO

BACKGROUND: To investigate the influence of small voxel Bayesian penalized likelihood (SVB) reconstruction on small lesion detection compared to ordered subset expectation maximization (OSEM) reconstruction using a clinical trials network (CTN) chest phantom and the patients with 18F-FDG-avid small lung tumors, and determine the optimal penalty factor for the lesion depiction and quantification. METHODS: The CTN phantom was filled with 18F solution with a sphere-to-background ratio of 3.81:1. Twenty-four patients with 18F-FDG-avid lung lesions (diameter < 2 cm) were enrolled. Six groups of PET images were reconstructed: routine voxel OSEM (RVOSEM), small voxel OSEM (SVOSEM), and SVB reconstructions with four penalty factors: 0.6, 0.8, 0.9, and 1.0 (SVB0.6, SVB0.8, SVB0.9, and SVB1.0). The routine and small voxel sizes are 4 × 4 × 4 and 2 × 2 × 2 mm3. The recovery coefficient (RC) was calculated by dividing the measured activity by the injected activity of the hot spheres in the phantom study. The SUVmax, target-to-liver ratio (TLR), contrast-to-noise ratio (CNR), the volume of the lesions, and the image noise of the liver were measured and calculated in the patient study. Visual image quality of the patient image was scored by two radiologists using a 5-point scale. RESULTS: In the phantom study, SVB0.6, SVB0.8, and SVB0.9 achieved higher RCs than SVOSEM. The RC was higher in SVOSEM than RVOSEM and SVB1.0. In the patient study, the SUVmax, TLR, and visual image quality scores of SVB0.6 to SVB0.9 were higher than those of RVOSEM, while the image noise of SVB0.8 to SVB1.0 was equivalent to or lower than that of RVOSEM. All SVB groups had higher CNRs than RVOSEM, but there was no difference between RVOSEM and SVOSEM. The lesion volumes derived from SVB0.6 to SVB0.9 were accurate, but over-estimated by RVOSEM, SVOSEM, and SVB1.0, using the CT measurement as the standard reference. CONCLUSIONS: The SVB reconstruction improved lesion contrast, TLR, CNR, and volumetric quantification accuracy for small lesions compared to RVOSEM reconstruction without image noise degradation or the need of longer emission time. A penalty factor of 0.8-0.9 was optimal for SVB reconstruction for the small tumor detection with 18F-FDG PET/CT.

16.
Materials (Basel) ; 14(6)2021 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-33810050

RESUMO

High boron steel is prone to brittle failure due to the boride distributed in it with net-like or fishbone morphology, which limit its applications. The Quenching and Partitioning (Q&P) heat treatment is a promising process to produce martensitic steel with excellent mechanical properties, especially high toughness by increasing the volume fraction of retained austensite (RA) in the martensitic matrix. In this work, the Q&P heat treatment is used to improve the inherent defect of insufficient toughness of high boron steel, and the effect mechanism of this process on microstructure transformation and the change of mechanical properties of the steel has also been investigated. The high boron steel as-casted is composed of martensite, retained austensite (RA) and eutectic borides. A proper quenching and partitioning heat treatment leads to a significant change of the microstructure and mechanical properties of the steel. The net-like and fishbone-like boride is partially broken and spheroidized. The volume fraction of RA increases from 10% in the as-cast condition to 19%, and its morphology also changes from blocky to film-like. Although the macro-hardness has slightly reduced, the toughness is significantly increased up to 7.5 J·cm-2, and the wear resistance is also improved.

17.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 28(5): 1674-1678, 2020 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-33067972

RESUMO

OBJECTIVE: To explore the correlation between the of regulatory T cells, Th17 cells and the prognosis of children with aplastic anemia. METHODS: The clinical data 13 children with aplastic anemia (AA) treated by antithymocyte globulin (ATG) combined with Cyclosporine in Beijing Children's Hospital, Capital Medical University from January 2017 to January 2018 were analyized retrospectively. The changes of T cell and Th17 cell expression level in peripheral blood of AA children before and after IST for 6 and 12 month were compared and analyzed. The SPSS 19.0 statistical package was used for data analysis. RESULTS: Compared with the pre-IST, the expression level of Treg cells decreased at 6 months of IST, the difference was statistically significant (P<0.05); however the expression level of Th17 cells did not show significant difference as compared with that pre-IST. The expression level of Treg and Th17 cells at 12 months of IST was lower than that pre-IST (P<0.01), compared with the level pre-IST, the ratio of Treg cells/Th17 cell at 6 months and 12 months of IST did not show a singificand difference. CONCLUSION: Treg cells and Th17 cells in peripheral blood of AA children decrease after IST, which suggests that the change of regulatory T cells and Th17 cells correlate with the clinical outcome of children with aplastic anemia.


Assuntos
Anemia Aplástica , Linfócitos T Reguladores , Criança , Humanos , Prognóstico , Estudos Retrospectivos , Células Th17
18.
Sleep Breath ; 24(4): 1767-1773, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32361960

RESUMO

PURPOSE: Obstructive sleep apnea (OSA) has been related to an increased risk of liver injury. Ferroptosis is a form of programmed cell death implicated in multiple physiological and pathological processes. This study aimed to explore the role of ferroptosis in chronic intermittent hypoxia (CIH)-induced liver injury as well as to uncover the underlying mechanisms using a CIH rat model. METHODS: Fourteen male Sprague-Dawley rats were randomly allocated to either the normal control (NC) (n = 7) or the CIH group (n = 7). Rats were exposed to intermittent hypoxia for 8 weeks in CIH group. Liver function, histological changes, and markers of oxidative stress were evaluated. The protein levels of hypoxia-inducible factor-1α, nuclear factor E2-related factor 2 (Nrf2), Acyl-CoA synthetase long-chain family member 4 (ACSL4), and glutathione peroxidase 4 (GPX4) in liver were examined by Western blot analysis. RESULTS: CIH treatment caused significant increase of serum alanine aminotransferase, aspartate aminotransferase, and malondialdehyde (MDA). Liver MDA was significantly higher in CIH group than that in NC group. Histology showed that CIH treatment induced discernible swelled, disordered hepatocytes, necrosis, and infiltrated inflammatory cells. CIH treatment significantly reduced the expression of GPX4, while markedly up-regulated expression of ACSL4, indicating elevation in hepatic ferroptosis. In addition, the protein expression of Nrf2 in CIH group was significantly lower than that in NC group. CONCLUSIONS: Ferroptosis played a crucial role in CIH-induced liver injury. The hepatic ferroptosis in CIH rat model might be mediated by the dysregulation of Nrf2. This highlights a potential therapeutic target for the treatment of OSA-related liver injury.


Assuntos
Ferroptose , Hipóxia/metabolismo , Fígado/lesões , Fígado/metabolismo , Animais , Modelos Animais de Doenças , Hipóxia/patologia , Peroxidação de Lipídeos , Fígado/patologia , Masculino , Estresse Oxidativo , Ratos Sprague-Dawley
19.
Eur J Nucl Med Mol Imaging ; 47(11): 2507-2515, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32424483

RESUMO

PURPOSE: The purpose was to investigate the effects of short acquisition time on the image quality and the lesion detectability of oncological 18F-FDG total-body PET/CT. METHODS: Nineteen oncological patients (6/13 women/men, age 65.6 ± 9.4 years) underwent total-body PET/CT on uEXPLORER scanner using 3D list mode. The administration of 18F-FDG was weight-based (4.4 MBq/kg). The acquisition time was 900 s, and PET data were reconstructed into 900-, 180-, 120-, 60-, 30-, and 18-s duration groups. The subjective PET image quality was scored using a 5-point scale (5, excellent; 1, poor) in 3 perspectives: overall quality, noise, and lesion conspicuity. The objective image quality was evaluated by SUVmax and standard deviation (SD) of the liver, SUVmax of the tumor, and tumor-to-background ratio (TBR). The lesion detectability was the percentage of identifiable lesions in the groups of 180 to 18 s using the group 900 s as reference. RESULTS: Our results showed that sufficient and acceptable subjective image quality could be achieved with 60- and 30-s groups, and good image quality scores were given to 180- and 120-s groups without significant difference. For shortened acquisition time, SD was increased, while SUVmax of tumor and TBR remained unchanged. The lesion detectability was decreased with shorter acquisition time, but the detection performance could be maintained until the 60-s group compared with the 900-s group, although the image quality degraded. CONCLUSION: The total-body PET/CT can significantly shorten the acquisition time with maintained lesion detectability and image quality.


Assuntos
Fluordesoxiglucose F18 , Neoplasias , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/diagnóstico por imagem , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Tomografia por Emissão de Pósitrons
20.
Org Lett ; 22(10): 3825-3829, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32378901

RESUMO

We describe an unprecedented dual C-H functionalization of indolin-2-one via an oxidative C(sp3)-H/N-H/X-H (X = N, C, S) cross-coupling protocol, which is catalyzed by a simple iron salt under mild and ligand-free conditions and employs air (molecular oxygen) as the terminal oxidant. This method is readily applicable for the construction of tetrasubstituted carbon centers from methylenes and provides a wide variety of spiro N-heterocyclic oxindoles.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...