Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 63
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
J Gene Med ; 26(1): e3584, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37605934

RESUMEN

BACKGROUND: Triple-negative breast cancer (TNBC) is a pathological subtype with a high mortality, and the development of inhibitors in the ubiquitin-proteasome system (UPS) component could be a novel therapeutic tool. METHODS: Triple-negative breast cancer data were obtained from The Cancer Genome Atlas (TCGA), and subtype analysis was performed by consistent clustering analysis to identify molecular subtypes of TNBC according to UPS characteristics. Differential analysis, COX and least absolute shrinkage and selection operator (LASSO) COX regression analyses were performed to select genes associated with overall survival in TNBC. The final prognostic model (UPS score) was determined using the LASSO COX model. The model performance was assessed using receiver operating characteristic (ROC) curves and survival curves. In addition, the results of the UPS score on analyzing the abundance of immune cell infiltration and immunotherapy were explored. Finally, we developed a nomogram for TNBC survival prediction. RESULTS: Two UPS subtypes (UPSMS1 and UPSMS2) showing significant survival differences were classified. COX regression analysis on differentially expressed genes in UPSMS1 and UPSMS2 filtered five genes that affected overall survival. Based on the regression coefficients and expression data of the five genes, we built a prognostic assessment system (UPS score). The UPS score showed consistent prognostic and therapeutic guidance values. Finally, the ROC curve of the nomogram and UPS score showed the highest predictive efficacy compared with traditional clinical prognostic indicators. CONCLUSION: The UPS score represented a promising prognostic tool to predict overall survival and immune status and guide personalized treatment selection in TNBC patients, and this study may provide a more practical alternative for clinical monitoring and management of TNBC.


Asunto(s)
Complejo de la Endopetidasa Proteasomal , Neoplasias de la Mama Triple Negativas , Humanos , Complejo de la Endopetidasa Proteasomal/genética , Neoplasias de la Mama Triple Negativas/genética , Neoplasias de la Mama Triple Negativas/terapia , Citoplasma , Inmunoterapia , Ubiquitinas
2.
Phys Chem Chem Phys ; 26(29): 20022-20036, 2024 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-39007185

RESUMEN

The chemical kinetic studies of hydrogen atom (H-atom) abstraction reactions by hydroperoxyl (HȮ2) radicals from five branched pentanol isomers, including 3-methyl-1-butanol, 2-methyl-1-butanol, 1,1-dimethyl-1-propanol, 1,2-dimethyl-1-propanol, and 2,2-dimethyl-1-propanol were investigated systematically through high-level ab initio calculations. Geometry optimization, frequency analysis, and zero-point energy (ZPE) corrections were performed for six reactants, twenty-three transition states (TSs), and twenty-four products at the M06-2X/6-311++G(d,p) level of theory. The intrinsic reaction coordinate calculation was performed at the same level of theory to confirm the transition state connection. The one-dimensional hindered rotor treatment for low-frequency torsional modes was also treated at the M06-2X/6-311++G(d,p) level of theory. The QCISD(T)/CBS level of theory was used to calculate the single-point energies for the species whose T1 diagnostic value was lower than 0.035. At the same time, the CASPT2/CBS level of theory was used to calculate the single-point energies for the channel in which the T1 diagnostic value of transition states was greater than 0.035. Rate constants for the H-atom abstraction reactions from the five branched pentanol isomers by HȮ2 radicals were calculated by using conventional transition state theory with asymmetric Eckart tunneling corrections in the temperature range of 500-2000 K. Rate constants and branching ratios for the title reactions and the rate rules for ten different H-atom abstraction types were investigated. Temperature-dependent thermochemistry properties for all reactants and products were calculated by the composite methods of G3/G4/CBS-QB3/CBS-APNO, which were in good agreement with the data available in the literature. Rate constants for the H-atom abstraction reactions by HȮ2 radical from branched pentanol isomers were investigated in this work as part I, and those for linear pentanol isomers will be analyzed in part II. All the calculated kinetics and thermochemistry data can be utilized in the model development for branched pentanol isomers oxidation.

3.
Phys Chem Chem Phys ; 26(21): 15494-15510, 2024 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-38752432

RESUMEN

High-level ab initio calculations are conducted for studying the kinetics of three linear pentanol radicals generated through H-atom abstraction reactions. The species involved are optimized using the M06-2X/6-311++G(d,p) level of theory, while a relaxed scan at the M06-2X/6-31g level of theory with 10° increments is used for the hindrance potential for low-frequency torsional modes. Single-point energies for all stationary points are obtained through the QCISD(T) and MP2 methods in combination with cc-pVDZ, cc-pVTZ, and cc-pVQZ basis sets, which can be extrapolated to the complete basis set (CBS) limit. The rate constants and branching ratios for isomerization and decomposition reactions are computed over a temperature range of 250-2000 K and a pressure range of 0.01-100 atm. Isomerization reactions are dominant at low temperatures, while decomposition reactions are more dominant at high temperatures. The branching ratio of the isomerization reaction exhibits a slight decrease with increasing pressure, while the trend for decomposition reactions depends on the type of the breaking bond. Based on the calculations for five branched pentanol radicals in part I, kinetics of linear and branched pentanol radicals are compared in this work and the results reveal that, for the same kind of ß-scission reaction at similar positions of linear and branched pentanol radicals, the rate constants of branched ones are faster than those of linear ones at low temperatures. The hydroxyl group adjacent to the breaking bond can increase the ß-scission reaction rate constants, while the effect can be ignored when the hydroxyl group is not adjacent to the breaking bond. Moreover, compared to when the hydroxyl group is located in the middle of the carbon chain, its positioning at the chain's end yields a more noticeable impact on the products and rate constants of C-O bond and O-H bond ß-scission reactions. Besides, when incorporating calculated rate constants into the CRECK model, the updated mechanism shows a better performance for ignition delay times of 1-pentanol in the NTC range but exhibits lower reactivity at higher temperatures. The simulation of speciation profiles also shows better agreement with the experimental data obtained using a flow reactor.

4.
Sensors (Basel) ; 24(5)2024 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-38475033

RESUMEN

To address the challenges faced in the prediction of rolling bearing life, where temporal signals are affected by noise, making fault feature extraction difficult and resulting in low prediction accuracy, a method based on optimal time-frequency spectra and the DenseNet-ALSTM network is proposed. Firstly, a signal reconstruction method is introduced to enhance vibration signals. This involves using the CEEMDAN deconvolution method combined with the Teager energy operator for signal reconstruction, aiming to denoise the signals and highlight fault impacts. Subsequently, a method based on the snake optimizer (SO) is proposed to optimize the generalized S-transform (GST) time-frequency spectra of the enhanced signals, obtaining the optimal time-frequency spectra. Finally, all sample data are transformed into the optimal time-frequency spectrum set and input into the DenseNet-ALSTM network for life prediction. The comparison experiment and ablation experiment show that the proposed method has high prediction accuracy and ideal prediction performance. The optimization terms used in different contexts in this paper are due to different optimization methods, specifically the CEEMDAN method.

5.
Nano Lett ; 23(4): 1144-1151, 2023 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-36749930

RESUMEN

Thermophotovoltaic (TPV) generators provide continuous and high-efficiency power output by utilizing local thermal emitters to convert energy from various sources to thermal radiation matching the bandgaps of photovoltaic cells. Lack of effective guidelines for thermal emission control at high temperatures, poor thermal stability, and limited fabrication scalability are the three key challenges for the practical deployment of TPV devices. Here we develop a hierarchical sequential-learning optimization framework and experimentally realize a 6″ module-scale polaritonic thermal emitter with bandwidth-controlled thermal emission as well as excellent thermal stability at 1473 K. The 300 nm bandwidth thermal emission is realized by a complex photon polariton based on the superposition of Tamm plasmon polariton and surface plasmon polariton. We experimentally achieve a spectral efficiency of 65.6% (wavelength range of 0.4-8 µm) with statistical deviation less than 4% over the 6″ emitter, demonstrating industrial-level reliability for module-scale TPV applications.

6.
Small ; 19(23): e2207736, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-36916696

RESUMEN

DNA self-assembly has been developed as a kind of robust signal amplification strategy, but most of reported assembly pathways are programmed to amplify signal in one direction. Herein, based on mutual-activated cascade cycle of hybridization chain reaction (HCR) and catalytic hairpin assembly (CHA), a closed cycle circuit (CCC) based DNA machine is developed for sensitive logic operation and molecular recognition. Benefiting from the synergistically accelerated signal amplification, the closed cyclic DNA machine enabled the logic computing with strong and significant output signals even at weak input signals. The typical logic operations such as OR, YES, AND, INHIBIT, NOR, and NAND gate, are conveniently and clearly executed with this DNA machine through rational design of the input and computing elements. Moreover, by integrating the target recognition module with the CCC module, the proposed DNA machine is further employed in the homogeneous detection of apurinic/apyrimidinic endonuclease 1 (APE1). The precise recognition and exponential signal amplification facilitated the highly selective and sensitive detection of APE1 with limit of detection (LOD) of 7.8 × 10-5 U mL-1 . Besides, the normal cells and tumor cells are distinguished unambiguously by this method according to the detected concentration difference of cellular APE1, which indicates the robustness and practicability of this method.


Asunto(s)
Técnicas Biosensibles , Técnicas Biosensibles/métodos , ADN , Hibridación de Ácido Nucleico , Lógica , Límite de Detección
7.
Small ; 19(7): e2206588, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36470658

RESUMEN

Potassium-ion batteries (PIBs) have become one of the promising candidates for electrochemical energy storage that can provide low-cost and high-performance advantages. The poor cyclability and rate capability of PIBs are due to the intensive structural change of electrode materials during battery operation. Carbon-based materials as anodes have been successfully commercialized in lithium- and sodium-ion batteries but is still struggling in potassium-ion battery field. This work conducts structural engineering strategy to induce anionic defects within the carbon structures to boost the kinetics of PIBs anodes. The carbon framework provides a strong and stable structure to accommodate the volume variation of materials during cycling, and the further phosphorus doping modification is shown to enhance the rate capability. This is found due to the change of the pore size distribution, electronic structures, and hence charge storage mechanism. The optimized electrode in this work shows a high capacity of 175 mAh g-1 at a current density of 0.2 A g-1 and the enhancement of rate performance as the PIB anode (60% capacity retention with the current density increase of 50 times). This work, therefore provides a rational design for guiding future research on carbon-based anodes for PIBs.

8.
Opt Express ; 31(24): 39811-39820, 2023 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-38041295

RESUMEN

We propose a scheme to achieve controllable nonreciprocal behavior in asymmetric graphene metasurfaces composed of a continuous graphene sheet and a poly crystalline silicon slab with periodic grooves of varying depths on each side. The proposed structure exhibits completely asymmetric reflection in opposite directions in the near-infrared range, which is attributed to the pronounced structural asymmetry and its accompanying nonlinear effects. The obtained nonreciprocal reflection ratio, reaching an impressive value of 21.27 dB, combined with a minimal insertion loss of just -0.76 dB, highlights the remarkable level of nonreciprocal efficiency achieved by this design compared to others in its category. More importantly, the proposed design can achieve dynamic tunability by controlling the incident field intensity and the graphene Fermi level. Our design highlights a potential means for creating miniaturized and integratable nonreciprocal optical components in reflection mode, which can promote the development of the integrated isolators, optical logic circuits, and bias-free nonreciprocal photonics.

9.
Phys Chem Chem Phys ; 25(26): 17320-17336, 2023 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-37345723

RESUMEN

Theoretical investigations on the kinetics of decomposition and isomerization reactions for five types of branched pentanol radicals are carried out in this work. The M06-2X/6-311++G(d,p) level of theory was used to optimize the geometries of all reactants, transition states, and products, while the hindrance potentials for the lower frequency modes in all of the species were obtained through a relaxed scan with an increment of 10° at the M06-2X/6-31G level of theory. Single-point energies of all species were determined at the QCISD(T)/cc-pVDZ, TZ level of theories with basis set corrections from MP2/cc-pVDZ, TZ, QZ methods. The RRKM/master equation was solved to calculate the pressure- and temperature-dependent rate coefficients for all channels in the pressure range of 0.01-100 atm over 250-2000 K. Pressure and temperature-dependent branching fractions of key species produced from pentanol radicals show that most of the pentanol radical isomers tend to isomerize to alkoxy radicals via a six-membered-ring or five-membered-ring transition state at low temperatures, producing ketones or aldehydes. At higher temperatures, the ß-scission reactions are the main reaction channels for the consumption of pentanol radicals. A weak pressure dependence has been found for all isomerization reactions, and it becomes more and more important as pressure increases. The pressure dependence trends are different for the ß-scission reactions of different branched pentanol radicals. In part I, the results for branched pentanol radical isomers are presented in detail, while in part II the results for linear pentanol radical isomers will be discussed.

10.
J Biochem Mol Toxicol ; 37(10): e23445, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37393522

RESUMEN

Diabetic nephropathy (DN) affects around 40% of people with diabetes, the final outcome of which is end-stage renal disease. The deficiency of autophagy and excessive oxidative stress have been found to participate in the pathogenesis of DN. Sinensetin (SIN) has been proven to have strong antioxidant capability. However, the effect of SIN on DN has not been studied. We examined the effect of SIN on cell viability and autophagy in the podocyte cell line, MPC5 cells, treated with high glucose (HG). For in vivo studies, DN mice models were established by intraperitoneal injected with streptozotocin (40 mg/kg) for 5 consecutive days and fed with a 60% high-fat diet, and SIN was given (10, 20, and 40 mg/kg) for 8 weeks via intraperitoneal injection. The results showed that SIN could protect MPC5 cells against HG-induced damage and significantly improve the renal function of DN mice. Moreover, SIN remarkably restored the autophagy activity of MPC5 cells which was inhibited under HG conditions. Consistent with this, SIN efficiently improved autophagy in the kidney tissue of DN mice. In brief, our findings demonstrated the protective effect of SIN on DN via restoring the autophagic function, which might provide a basis for drug development.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA