Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 96
Filtrar
1.
ACS Appl Mater Interfaces ; 16(17): 21672-21688, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38637290

RESUMO

Titanium (Ti) and its alloys are widely used as hard tissue substitutes in dentistry and orthopedics, but their low bioactivity leads to undesirable osseointegration defects in the early osteogenic phase. Surface modification is an important approach to overcome these problems. In the present study, novel magnesium phosphate (MgP) coatings with controllable structures were fabricated on the surface of Ti using the phosphate chemical conversion (PCC) method. The effects of the microstructure on the physicochemical and biological properties of the coatings on Ti were researched. The results indicated that accelerators in PCC solution were important factors affecting the microstructure and properties of the MgP coatings. In addition, the coated Ti exhibited excellent hydrophilicity, high bonding strength, and good corrosion resistance. Moreover, the biological results showed that the MgP coatings could improve the spread, proliferation, and osteogenic differentiation of mouse osteoblast cells (MC3T3-E1) and vascular differentiation of human umbilical vein endothelial cells (HUVECs), indicating that the coated Ti samples had a great effect on promoting osteogenesis and angiogenesis. Overall, this study provided a new research idea for the surface modification of conventional Ti to enhance osteogenesis and angiogenesis in different bone types for potential biomedical applications.


Assuntos
Diferenciação Celular , Proliferação de Células , Materiais Revestidos Biocompatíveis , Células Endoteliais da Veia Umbilical Humana , Compostos de Magnésio , Neovascularização Fisiológica , Osteogênese , Fosfatos , Titânio , Titânio/química , Titânio/farmacologia , Osteogênese/efeitos dos fármacos , Animais , Camundongos , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/farmacologia , Fosfatos/química , Fosfatos/farmacologia , Compostos de Magnésio/química , Compostos de Magnésio/farmacologia , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Neovascularização Fisiológica/efeitos dos fármacos , Osteoblastos/efeitos dos fármacos , Osteoblastos/citologia , Propriedades de Superfície , Linhagem Celular , Angiogênese
2.
Adv Mater ; : e2311652, 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38502781

RESUMO

The explosive growth of massive-data storage and the demand for ultrafast data processing require innovative memory devices with exceptional performance. 2D materials and their van der Waal heterostructures with atomically sharp interfaces hold great promise for innovations in memory devices. Here, this work presents non-volatile, floating-gate memory devices with all functional layers made of 2D materials, achieving ultrafast programming/erasing speeds (20 ns), high extinction ratios (up to 108), and multi-bit storage capability. These devices also exhibit long-term data retention exceeding 10 years, facilitated by a high gate-coupling ratio (GCR) and atomically sharp interfaces between functional layers. Additionally, this work demonstrates the realization of an "OR" logic gate on a single-device unit by synergistic electrical and optical operations. The present results provide a solid foundation for next-generation ultrahigh-speed, ultralong lifespan, non-volatile memory devices, with a potential for scale-up manufacturing and flexible electronics applications.

3.
J Cell Mol Med ; 28(1): e18021, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37994489

RESUMO

Clinical assessments relying on pathology classification demonstrate limited effectiveness in predicting clinical outcomes and providing optimal treatment for patients with ovarian cancer (OV). Consequently, there is an urgent requirement for an ideal biomarker to facilitate precision medicine. To address this issue, we selected 15 multicentre cohorts, comprising 12 OV cohorts and 3 immunotherapy cohorts. Initially, we identified a set of robust prognostic risk genes using data from the 12 OV cohorts. Subsequently, we employed a consensus cluster analysis to identify distinct clusters based on the expression profiles of the risk genes. Finally, a machine learning-derived prognostic signature (MLDPS) was developed based on differentially expressed genes and univariate Cox regression genes between the clusters by using 10 machine-learning algorithms (101 combinations). Patients with high MLDPS had unfavourable survival rates and have good prediction performance in all cohorts and in-house cohorts. The MLDPS exhibited robust and dramatically superior capability than 21 published signatures. Of note, low MLDIS have a positive prognostic impact on patients treated with anti-PD-1 immunotherapy by driving changes in the level of infiltration of immune cells. Additionally, patients suffering from OV with low MLDIS were more sensitive to immunotherapy. Meanwhile, patients with low MLDIS might benefit from chemotherapy, and 19 compounds that may be potential agents for patients with low MLDIS were identified. MLDIS presents an appealing instrument for the identification of patients at high/low risk. This could enhance the precision treatment, ultimately guiding the clinical management of OV.


Assuntos
Neoplasias Ovarianas , Humanos , Feminino , Prognóstico , Imunoterapia , Algoritmos , Aprendizado de Máquina , Microambiente Tumoral
5.
BMC Womens Health ; 23(1): 555, 2023 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-37884919

RESUMO

OBJECTIVE: This study aimed to explore metabolic abnormalities in cervical squamous cell carcinoma and endocervical adenocarcinoma (CESC) for metabolism-related genes. METHODS: We downloaded expression data for metabolism-related genes, performed differential expression analysis, and applied weighted gene co-expression network analysis (WGCNA) to identify metabolism-related functional modules. We obtained normalised miRNA expression data and identified master methylation regulators for metabolism-related genes. Cox regression of data on metabolism-related genes was performed to screen for genes that affect the prognosis of patients with CESC. Furthermore, we selected key genes for validation. RESULTS: Our results identified 3620 metabolism-related genes in CESC, 2493 of which contained related mutations. The co-occurrence of CUBN, KALRN, and HERC1 was related to the prognosis of CESC. The fraction of genome altered (FGA) closely correlated with overall survival. In expression analysis, 374 genes were related to the occurrence and prognosis of CESC. We then identified four metabolic pathway modules in WGCNA. Further analysis revealed that glycolysis/gluconeogenesis was related to endothelial cells and that arachidonic acid metabolism was related to cell proliferation. These four modules were also related to the prognosis of CESC. Among CESC-related metabolic genes, two genes were found to be regulated by microRNAs (miRNAs) and methylation, whereas another two genes were coregulated by miRNAs and mutations. CONCLUSIONS: Among metabolism-related genes, 15 genes were related to the prognosis of CESC. The co-occurrence of CUBN/KALRN/HERC1 was associated with CESC prognosis. Glycolysis/gluconeogenesis was related to endothelial cells, and arachidonic acid metabolism was related to cell proliferation.


Assuntos
Carcinoma de Células Escamosas , MicroRNAs , Neoplasias do Colo do Útero , Feminino , Humanos , Neoplasias do Colo do Útero/genética , Ácido Araquidônico , Células Endoteliais , MicroRNAs/genética , Prognóstico
6.
Eur J Med Res ; 28(1): 402, 2023 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-37798729

RESUMO

BACKGROUND: To date, there is no consensus on whether intrauterine insemination (IUI) treatment is required in young patients with diminished ovarian reserve (DOR). Pregnancy outcomes in young DOR patients undergoing IUI are controversial. The existing studies are all single-center studies, with no existing multicenter cohort studies. The purpose of this multicenter study was to investigate the pregnancy outcomes of young DOR patients undergoing IUI. METHODS: This multicenter cohort study included a total of 4600 cycles in 2204 infertile patients who underwent IUI treatment in three reproductive medical centers between September 2018 and January 2022. The research subjects were divided into two groups according to their serum anti-Müllerian hormone (AMH) levels. Propensity score matching (PSM) was used to match the research subjects at a ratio of 1:4. The pregnancy outcomes in the two groups were compared. RESULTS: There was no significant difference in the clinical pregnancy rates (CPR), biochemical rates, and ectopic pregnancy rates between the two groups (P > 0.05). There were, however, significant differences in the miscarriage rates between the groups (P < 0.05). The live birth rates (LBR) were 6.6 vs. 9.9 between the two groups. The multivariable logistic regression models reveal that body mass index, AMH were significantly correlated with CPR; AMH were significantly correlated with LBR; BMI, follicle stimulating hormone were significantly correlated with miscarriage rate. CONCLUSIONS: The clinical pregnancy rate of DOR patients was not significantly different from that of NOR patients; however, the miscarriage rates were significantly different from those of NOR patients.


Assuntos
Aborto Espontâneo , Reserva Ovariana , Gravidez , Feminino , Humanos , Resultado da Gravidez , Estudos de Coortes , Taxa de Gravidez , Hormônio Antimülleriano , Inseminação , Estudos Retrospectivos
7.
Bioorg Chem ; 141: 106838, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37717414

RESUMO

Six pyrazolopyrimidine rhodium(III) or palladium(II) complexes, [Rh(L1)(H2O)Cl3] (1), [Rh(L2)(CH3OH)Cl3] (2), [Rh(L3)(H2O)Cl3] (3), [Rh2(L4)Cl6]·CH3OH (4), [Rh(L5)(CH3CN)Cl3]·0.5CH3CN (5), and [Pd(L5)Cl2] (6), were synthesized and characterized. These complexes showed high cytotoxicity against six tested cancer cell lines. Most of the complexes showed higher cytotoxicity to T-24 cells in vitro than cisplatin. Mechanism studies indicated that complexes 5 and 6 induced G2/M phase cell cycle arrest through DNA damage, and induced apoptosis via endoplasmic reticulum stress response. In addition, complex 5 also induced cell apoptosis via mitochondrial dysfunction. Complexes 5 and 6 showed low in vivo toxicity and high tumor growth inhibitory activity in mouse tumor models. The inhibitory effect of rhodium complex 5 on tumor growth in vivo was more pronounced than that of palladium complex 6.


Assuntos
Antineoplásicos , Complexos de Coordenação , Neoplasias , Ródio , Animais , Camundongos , Antineoplásicos/farmacologia , Antineoplásicos/metabolismo , Ródio/farmacologia , Paládio/farmacologia , Linhagem Celular , Neoplasias/tratamento farmacológico , Apoptose , Complexos de Coordenação/farmacologia , Linhagem Celular Tumoral
8.
Rev Sci Instrum ; 94(9)2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37671954

RESUMO

We developed a new scheme for cryogen-free cooling down to sub-3 K temperature range and ultra-low vibration level. An ultra-high-vacuum cryogen-free scanning probe microscope (SPM) system was built based on the new scheme. Instead of mounting a below-decoupled cryocooler directly onto the system, the new design was realized by integrating a Gifford-McMahon cryocooler into a separate liquefying chamber, providing two-stage heat exchangers in a remote way. About 10 L of helium gas inside the gas handling system was cooled, liquefied in the liquefying chamber, and then transferred to a continuous-flow cryostat on the SPM chamber through an ∼2 m flexible helium transfer line. The exhausted helium gas from the continuous-flow cryostat was then returned to the liquefying chamber for reliquefaction. A base temperature of ∼2.84 K at the scanner sample stage and a temperature fluctuation of almost within ±0.1 mK at 4 K were achieved. The cooling curves, tunneling current noise, variable-temperature test, scanning tunneling microscopy and non-contact atomic force microscopy imaging, and first and second derivatives of I(V) spectra are characterized to verify that the performance of our cryogen-free SPM system is comparable to the bath cryostat-based low-temperature SPM system. This remote liquefaction close-cycle scheme shows conveniency to upgrade the existing bath cryostat-based SPM system, upgradeability of realizing even lower temperature down to sub-1 K range, and great compatibility of other physical environments, such as high magnetic field and optical accesses. We believe that the new scheme could also pave a way for other cryogenic applications requiring low temperature but sensitive to vibration.

9.
Molecules ; 28(15)2023 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-37570605

RESUMO

Organic thioethers play an important role in the discovery of drugs and natural products. However, the green synthesis of organic sulfide compounds remains a challenging task. The convenient and efficient synthesis of 5-alkoxy-3-halo-4-methylthio-2(5H)-furanones from DMSO is performed via the mediation of 1,3-dibromo-5,5-dimethylhydantoin (DBDMH), affording a facile route for the sulfur-functionalization of 3,4-dihalo-2(5H)-furanones under transition metal-free conditions. This new approach has demonstrated the functionalization of non-aromatic Csp2-X-type halides with unique structures containing C-X, C-O, C=O and C=C bonds. Compared with traditional synthesis methods using transition metal catalysts with ligands, this reaction has many advantages, such as the lower temperature, the shorter reaction time, the wide substrate range and good functional group tolerance. Notably, DMSO plays multiple roles, and is simultaneously used as an odorless methylthiolating reagent and safe solvent.

10.
Materials (Basel) ; 16(16)2023 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-37629946

RESUMO

Selective laser melting (SLM) of high-temperature alloys involves intricate interdependencies among key process parameters, such as laser power and scanning speed, affecting properties such as density and tensile strength. However, relying solely on experiential knowledge for process parameter design often hampers the precise attainment of target requirements. To address this challenge, we propose an innovative approach that integrates the analytic hierarchy process (AHP) and weighted particle swarm optimization (WPSO) to recommend SLM process parameters for high-temperature alloy fabrication. Our proposed AHP-WPSO model consists of three main steps. First, a comprehensive historical database is established, capturing the process parameters and performance metrics of high-temperature alloy SLM parts. Utilizing an AHP framework, we compute the performance similarity between target and historical cases, applying rational thresholds to identify analogous cases. When suitable analogs are elusive, the model seamlessly transitions to the second step. Here, the WPSO model optimizes and recommends process parameters according to target specifications. Lastly, our experimental validation of the GH4169 high-temperature alloy through SLM experiments corroborates the effectiveness of our AHP-WPSO model in making process parameter recommendations. The outcomes underscore the model's high accuracy, attaining a recommendation precision of 99.81% and 96.32% when historical analogs are present and absent, respectively. This innovative approach offers a robust and reliable solution to the challenges posed in SLM process parameter optimization for high-temperature alloy applications.

11.
J Med Chem ; 66(14): 9592-9606, 2023 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-37432720

RESUMO

As a continuation of our endeavors in discovering metal-based drugs with cytotoxic and antimetastatic activities, herein, we reported the syntheses of 11 new rhodium(III)-picolinamide complexes and the exploration of their potential anticancer activities. These Rh(III) complexes showed high antiproliferative activity against the tested cancer cell lines in vitro. The mechanism study indicated that Rh1 ([Rh(3a)(CH3CN)Cl2]) and Rh2 ([Rh(3b)(CH3CN)Cl2]) inhibited cell proliferation by multiple modes of action via cell cycle arrest, apoptosis, and autophagy and inhibited cell metastasis via FAK-regulated integrin ß1-mediated suppression of EGFR expression. Furthermore, Rh1 and Rh2 significantly inhibited bladder cancer growth and breast cancer metastasis in a xenograft model. These rhodium(III) complexes could be developed as potential anticancer agents with antitumor growth and antimetastasis activity.


Assuntos
Antineoplásicos , Neoplasias da Mama , Complexos de Coordenação , Ródio , Humanos , Feminino , Ródio/farmacologia , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Apoptose , Proliferação de Células , Autofagia , Linhagem Celular Tumoral , Complexos de Coordenação/farmacologia , Complexos de Coordenação/uso terapêutico
12.
Adv Mater ; 35(32): e2301067, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37204321

RESUMO

The development of electrically ultrafast-programmable semiconductor homojunctions can lead to transformative multifunctional electronic devices. However, silicon-based homojunctions are not programmable so that alternative materials need to be explored. Here 2D, multi-functional, lateral homojunctions made of van der Waals heterostructures with a semi-floating-gate configuration on a p++ Si substrate feature atomically sharp interfaces and can be electrostatically programmed in nanoseconds, more than seven orders of magnitude faster than other 2D-based homojunctions. By applying voltage pulses with different polarities, lateral p-n, n+ -n and other types of homojunctions can be formed, varied, and reversed. The p-n homojunctions possess a high rectification ratio of up to ≈105 and can be dynamically switched between four distinct conduction states with the current spanning over nine orders of magnitude, enabling them to function as logic rectifiers, memories, and multi-valued logic inverters. Built on a p++ Si substrate, which acts as the control gate, the devices are compatible with Si technology.

13.
Curr Med Sci ; 43(2): 336-343, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37059936

RESUMO

OBJECTIVE: This study aims to construct and validate a predictable deep learning model associated with clinical data and multi-sequence magnetic resonance imaging (MRI) for short-term postoperative facial nerve function in patients with acoustic neuroma. METHODS: A total of 110 patients with acoustic neuroma who underwent surgery through the retrosigmoid sinus approach were included. Clinical data and raw features from four MRI sequences (T1-weighted, T2-weighted, T1-weighted contrast enhancement, and T2-weighted-Flair images) were analyzed. Spearman correlation analysis along with least absolute shrinkage and selection operator regression were used to screen combined clinical and radiomic features. Nomogram, machine learning, and convolutional neural network (CNN) models were constructed to predict the prognosis of facial nerve function on the seventh day after surgery. Receiver operating characteristic (ROC) curve and decision curve analysis (DCA) were used to evaluate model performance. A total of 1050 radiomic parameters were extracted, from which 13 radiomic and 3 clinical features were selected. RESULTS: The CNN model performed best among all prediction models in the test set with an area under the curve (AUC) of 0.89 (95% CI, 0.84-0.91). CONCLUSION: CNN modeling that combines clinical and multi-sequence MRI radiomic features provides excellent performance for predicting short-term facial nerve function after surgery in patients with acoustic neuroma. As such, CNN modeling may serve as a potential decision-making tool for neurosurgery.


Assuntos
Aprendizado Profundo , Neuroma Acústico , Humanos , Nervo Facial/diagnóstico por imagem , Neuroma Acústico/diagnóstico por imagem , Neuroma Acústico/cirurgia , Imageamento por Ressonância Magnética/métodos , Prognóstico
14.
J Integr Plant Biol ; 65(6): 1536-1552, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37073786

RESUMO

Although root nodules are essential for biological nitrogen fixation in legumes, the cell types and molecular regulatory mechanisms contributing to nodule development and nitrogen fixation in determinate nodule legumes, such as soybean (Glycine max), remain incompletely understood. Here, we generated a single-nucleus resolution transcriptomic atlas of soybean roots and nodules at 14 days post inoculation (dpi) and annotated 17 major cell types, including six that are specific to nodules. We identified the specific cell types responsible for each step in the ureides synthesis pathway, which enables spatial compartmentalization of biochemical reactions during soybean nitrogen fixation. By utilizing RNA velocity analysis, we reconstructed the differentiation dynamics of soybean nodules, which differs from those of indeterminate nodules in Medicago truncatula. Moreover, we identified several putative regulators of soybean nodulation and two of these genes, GmbHLH93 and GmSCL1, were as-yet uncharacterized in soybean. Overexpression of each gene in soybean hairy root systems validated their respective roles in nodulation. Notably, enrichment for cytokinin-related genes in soybean nodules led to identification of the cytokinin receptor, GmCRE1, as a prominent component of the nodulation pathway. GmCRE1 knockout in soybean resulted in a striking nodule phenotype with decreased nitrogen fixation zone and depletion of leghemoglobins, accompanied by downregulation of nodule-specific gene expression, as well as almost complete abrogation of biological nitrogen fixation. In summary, this study provides a comprehensive perspective of the cellular landscape during soybean nodulation, shedding light on the underlying metabolic and developmental mechanisms of soybean nodule formation.


Assuntos
Ascomicetos , Medicago truncatula , Fixação de Nitrogênio/genética , Glycine max/fisiologia , Nodulação/genética , Nódulos Radiculares de Plantas/genética , Nódulos Radiculares de Plantas/metabolismo , Transcriptoma/genética , Citocininas/metabolismo , Medicago truncatula/genética , Medicago truncatula/metabolismo , Simbiose/genética , Regulação da Expressão Gênica de Plantas/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Nitrogênio/metabolismo
15.
Nat Prod Res ; 37(15): 2551-2558, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35319320

RESUMO

One new alkaloid, 6, 7-dimethoxyisoquinoline-N-oxide (1), one new benzofuran derivative, 3,7-dimethyl-6-acetyl-8-benzofuranol (2) and one new lignan, salsolains A (3), along with seven known compounds (4-10), were isolated from the whole plant of Salsola collina Pall. Their structures were elucidated by extensive analysis of spectroscopic data (IR, UV, HR-ESI-MS, 1 D and 2 D NMR), and their absolute configurations were determined by the X-ray crystallography and ECD calculation. The activities of compounds 1-10 against inflammatory cytokines IL-6 and TNF-α levels on LPS-induced RAW 264.7 macrophages were assessed, especially, compound 5 (50 µM) exhibited the most significant anti-inflammatory activity with the secretion levels of IL-6 and TNF-α at 3.87% and 4.03%, respectively.


Assuntos
Alcaloides , Salsola , Animais , Camundongos , Salsola/química , Fator de Necrose Tumoral alfa , Interleucina-6 , Macrófagos , Células RAW 264.7 , Estrutura Molecular
16.
Front Nutr ; 9: 1053811, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36570142

RESUMO

Kaempferia elegans polysaccharide (KEP) was extracted using a high-voltage pulsed electric field-assisted hot water method. Its physicochemical properties, in vitro activity and hypoglycemic effect was investigated. Experiments were undertaken with diabetic mice models and the potential mechanism of KEP to improve blood glucose levels was unveiled through measurements of relevant indicators in the serum and liver of the mice. Results showed that KEP is mainly composed of glucose, rhamnose, arabinose, and galactose. It has certain DPPH and ABTS free radical scavenging ability and good α-glucosidase inhibitory ability, indicating that KEP has the potential to improve blood glucose levels in diabetes patients. The experimental results of KEP treatment on mice showed that KEP could control the continuous increase of fasting blood glucose levels. The potential mechanisms behind this blood glucose level control composes of (1) increasing the glucokinase and C peptide levels and decreasing Glucose-6-phosphatase content for improving key enzyme activity in the glucose metabolism pathway. This promotes the consumption of blood glucose during glycolysis, thereby inhibiting the production of endogenous glucose in gluconeogenesis pathway; (2) reducing triglyceride, total cholesterol, low density lipoprotein cholesterol, and increasing high density lipoprotein cholesterol content, for regulating blood lipid indicators to normal levels; and (3) by improving the activities of catalase, glutathione peroxidase, and antioxidant enzymes superoxide dismutase for further improving the antioxidant defense system in the body to reduce blood glucose.

17.
Adv Mater ; 34(35): e2204779, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35816107

RESUMO

Monolayer Six Cy constitutes an important family of 2D materials that is predicted to feature a honeycomb structure and appreciable bandgaps. However, due to its binary chemical nature and the lack of bulk polymorphs with a layered structure, the fabrication of such materials has so far been challenging. Here, the synthesis of atomic monolayer Si9 C15 on Ru (0001) and Rh(111) substrates is reported. A combination of scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), scanning transmission electron microscopy (STEM), and density functional theory (DFT) calculations is used to infer that the 2D lattice of Si9 C15 is a buckled honeycomb structure. Monolayer Si9 C15 shows semiconducting behavior with a bandgap of ≈1.9 eV. Remarkably, the Si9 C15 lattice remains intact after exposure to ambient conditions, indicating good air stability. The present work expands the 2D-materials library and provides a promising platform for future studies in nanoelectronics and nanophotonics.

18.
Dalton Trans ; 51(5): 1968-1978, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-35023532

RESUMO

Four mononuclear terpyridine complexes [Cu(H-La)Cl2]·CH3OH (1), [Cu(H-La)Cl]ClO4 (2), [Cu(H-Lb)Cl2]·CH3OH (3), and [Cu(H-Lb)(CH3OH)(DMSO)](ClO4)2 (4) were prepared and fully characterized. Complexes 1-4 exhibited higher cytotoxic activity against several tested cancer cell lines especially BEL-7402 cells compared to cisplatin, and they showed low toxicity towards normal human liver cells. ICP-MS detection indicated that the copper complexes were accumulated in mitochondria. Mechanistic studies demonstrated that the copper complexes induced G0/G1 arrest and altered the expression of the related proteins of the cell cycle. All copper complexes reduced the mitochondrial membrane potential while increasing the intracellular ROS levels and the release of Ca2+. They also up-regulated Bax and down-regulated Bcl-2 expression levels, caused cytochrome c release and the activation of the caspase cascade, and induced mitochondrion-mediated apoptosis. Animal studies demonstrated that complex 1 suppressed tumor growth in a mouse xenograft model bearing BEL-7402 tumor cells.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Piridinas/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Cálcio/metabolismo , Caspase 3/genética , Caspase 3/metabolismo , Caspase 9/genética , Caspase 9/metabolismo , Linhagem Celular Tumoral , Cisplatino/farmacologia , Complexos de Coordenação , Cobre , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Modelos Moleculares , Estrutura Molecular , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Piridinas/síntese química , Piridinas/química , Espécies Reativas de Oxigênio , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismo
19.
Nanotechnology ; 33(15)2022 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-34952533

RESUMO

Voltage-driven stochastic magnetization switching in a nanomagnet has attracted more attention recently with its superiority in achieving energy-efficient artificial neuron. Here, a novel pure voltage-driven scheme with ∼27.66 aJ energy dissipation is proposed, which could rotate magnetization vector randomly using only a pair of electrodes covered on the multiferroic nanomagnet. Results show that the probability of 180° magnetization switching is examined as a sigmoid-like function of the voltage pulse width and magnitude, which can be utilized as the activation function of designed neuron. Considering the size errors of designed neuron in fabrication, it's found that reasonable thickness and width variations cause little effect on recognition accuracy for MNIST hand-written dataset. In other words, the designed pure voltage-driven spintronic neuron could tolerate size errors. These results open a new way toward the realization of artificial neural network with low power consumption and high reliability.

20.
Hemoglobin ; 45(5): 329-331, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34957901

RESUMO

Homozygous or compound heterozygous mutations of the ß-globin gene lead to ß-thalassemia (ß-thal) major (ß-TM) or ß-thal intermedia (ß-TI), whereas heterozygotes usually show microcytosis with negligible or no hemolysis. Certain missense mutations in exon 3, however, produce unstable globins causing a dominant ß-thal phenotype or hemolytic anemia in heterozygotes. Here we report a mutation in exon 3 of the ß-globin gene, which results in an unstable globin (Hb Dieppe) [ß127(H5)Gln→Arg; HBB: c.383A>G] with a dominant ß-thal phenotype in two generations of a Chinese family. Physicians should be alerted to this mechanism of ß-thal considering its relative rarity.


Assuntos
Talassemia beta , Éxons , Humanos , Mutação , Fenótipo , Globinas beta/genética , Talassemia beta/diagnóstico , Talassemia beta/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA