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1.
Biomacromolecules ; 25(8): 4991-5007, 2024 Aug 12.
Artículo en Inglés | MEDLINE | ID: mdl-39087761

RESUMEN

The GPS-Nanoconveyor (MA-NV@DOX-Cas13a) is a targeted nanoplatform designed for the imaging and gene/chemotherapy synergistic treatment of melanoma. It utilizes rolling circle amplification (RCA) products as a scaffold to construct a DNA "Nanoconveyor" (NV), which incorporates a multivalent aptamer (MA) as a "GPS", encapsulates doxorubicin (DOX) in the transporter, and equips it with CRISPR/Cas13a ribonucleoproteins (Cas13a RNP). Carrying MA enhances the ability to recognize the overexpressed receptor nucleolin on B16 cells, enabling targeted imaging and precise delivery of MA-NV@DOX-Cas13a through receptor-mediated endocytosis. The activation of signal transducer and activator of transcription 3 (STAT3) in cancer cells triggers cis-cleavage of CRISPR/Cas13a, initiating its trans-cleavage function. Additionally, deoxyribonuclease I (DNase I) degrades MA-NV, releasing DOX for intracellular imaging and as a chemotherapeutic agent. Experiments demonstrate the superior capabilities of this versatile nanoplatform for cellular imaging and co-treatment while highlighting the advantages of these nanodrug delivery systems in mitigating DOX side effects.


Asunto(s)
Sistemas CRISPR-Cas , Doxorrubicina , Doxorrubicina/farmacología , Doxorrubicina/química , Doxorrubicina/administración & dosificación , Animales , Ratones , Humanos , Aptámeros de Nucleótidos/química , Técnicas de Amplificación de Ácido Nucleico/métodos , Línea Celular Tumoral , Antibióticos Antineoplásicos/farmacología , Antibióticos Antineoplásicos/administración & dosificación , Antibióticos Antineoplásicos/química
2.
Environ Sci Technol ; 2024 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-39137285

RESUMEN

The consumption of disposable surgical masks (DSMs) considerably increased during the coronavirus pandemic in 2019. Herein, we explored the spread of antibiotic resistance genes (ARGs) and the potential risks of antibiotic resistant bacteria (ARB) on DSMs. At environmentally relevant concentrations, the conjugate transfer frequency (CTF) of ARGs increased by 1.34-2.37 folds by 20 µg/m3 of atmospheric water-soluble inorganic ions (WSIIs), and it increased by 2.62-2.86 folds by 80 ng/m3 of polycyclic aromatic hydrocarbons (PAHs). Total suspended particulates (TSP) further promoted the CTF in combination with WSIIs or PAHs. Under WSII and PAH exposure, gene expression levels related to oxidative stress, cell membrane, and the adenosine triphosphate (ATP) were upregulated. WSIIs predominantly induced cellular contact, while PAHs triggered ATP formation and membrane damage. Molecular dynamics simulations showed that WSIIs and PAHs reduced membrane lipid fluidity and increased membrane permeability through interactions with the phosphatidylcholine bilayer. DSM filtering performance decreased, and the CTF of ARGs increased with the wearing time. The gut simulator test showed that ARB disrupted the human gut microbial community and increased total ARG abundance but did not change the ARG abundance carried by ARB themselves. A mathematical model showed that long-term WSII and PAH exposure accelerated ARG dissemination in DSMs.

3.
Org Lett ; 2024 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-39106520

RESUMEN

Herein we unveil a visible-light-driven transition-metal-free 1,3-bromodifluoroallylation of [1.1.1]propellane. This reactivity is harnessed through organophotocatalysis, providing practical synthetic pathways to 1-brominated-3-gem-difluoroallylic bicyclo[1.1.1]pentane derivatives, particularly derived from readily available α-trifluoromethylalkenes and inexpensive KBr salts utilized as precursors for bromine radicals. Mechanistic investigations reveal that bromide anions quench the excited state of the photocatalyst, leading to the formation of bromine radicals, which react in a strain-release radical addition process rather than hydrogen atom abstraction with [1.1.1]propellane.

4.
ACS Nano ; 2024 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-39102459

RESUMEN

Recent years have witnessed the explosive development of highly sensitive smart sensors based on conductive polymer foam materials. However, the design and development of multifunctional polymeric foam composites as smart sensors applied in complex solvent and oil environments remain a critical challenge. Herein, we design and synthesize vinyl-terminated polytrifluoropropylmethylsiloxane through anionic ring-opening polymerization to fabricate fluorosilicone rubber foam (FSiRF) materials with nanoscale wrinkled surfaces and reactive Si-H groups via a green and rapid chemical foaming strategy. Based on the strong adhesion between FSiRF materials and consecutive oxidized ketjen black (OKB) nano-network, multifunctional FSiRF nanocomposites were prepared by a dip-coating strategy followed by fluoroalkylsilane modification. The optimized F-OKB@FSiRF nanocomposites exhibit outstanding mechanical flexibility in wide-temperature range (100 cycle compressions from -20 to 200 °C), structure stability (no detached particles after being immersed into various aqueous solutions for up to 15 days), surface superhydrophobicity (water contact angle of 154° and sliding angle of ∼7°), and tunable electrical conductivity (from 10-5 to 10-2 S m-1). Additionally, benefiting from the combined actions of multiple lines of defense (low surface energy groups, physical barriers, and "shielding effect"), the F-OKB@FSiRF sensor presents excellent anti-swelling property and high sensitivity in monitoring both large-deformation and tiny vibrations generated by knocking the beaker, ultrasonic action, agitating, and sinking objects in weak-polar or nonpolar solvents. This work conceivably provides a chemical strategy for the fabrication of multifunctional polymeric foam nanocomposite materials as smart sensors for broad applications.

5.
Angew Chem Int Ed Engl ; : e202406705, 2024 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-39049163

RESUMEN

Solution-processed perovskite films generally possess small grain sizes and high density of grain boundaries, which intensify non-radiative recombination of carriers and limits the power conversion efficiency (PCE) of solar cells. In this study, we report the room-temperature ripening enabled by the synergy of hygroscopic salts and moisture in air for efficient hole-conductor-free printable mesoscopic perovskite solar cells (p-MPSCs). Treating perovskite films with proper hygroscopic salts in damp air induces obvious secondary recrystallization, which coarsens the grains size from hundreds of nanometers to several micrometers. It's proposed that the hygroscopic salt at grain boundaries could absorb moisture and form a complex which could not only serve as mass transfer channel but also assist in the dissolution of perovskite grains. This activates mass transfer between small grains and large grains since they possess different solubilities, and thus ripens the perovskite film. Consequently, p-MPSCs treated with the hygroscopic salt of NH4SCN show an improved power conversion efficiency of 20.13% from 17.94%, and maintain >98% of the initial efficiency under maximum power point tracking at 55±5°C for 350 hours.

6.
J Imaging Inform Med ; 2024 Jul 29.
Artículo en Inglés | MEDLINE | ID: mdl-39075250

RESUMEN

In the domain of medical image segmentation, traditional diffusion probabilistic models are hindered by local inductive biases stemming from convolutional operations, constraining their ability to model long-term dependencies and leading to inaccurate mask generation. Conversely, Transformer offers a remedy by obviating the local inductive biases inherent in convolutional operations, thereby enhancing segmentation precision. Currently, the integration of Transformer and convolution operations mainly occurs in two forms: nesting and stacking. However, both methods address the bias elimination at a relatively large granularity, failing to fully leverage the advantages of both approaches. To address this, this paper proposes a conditional diffusion segmentation model named TransDiffSeg, which combines Transformer with convolution operations from traditional diffusion models in a parallel manner. This approach eliminates the accumulated local inductive bias of convolution operations at a finer granularity within each layer. Additionally, an adaptive feature fusion block is employed to merge conditional semantic features and noise features, enhancing global semantic information and reducing the Transformer's sensitivity to noise features. To validate the impact of granularity in bias elimination on performance and the impact of Transformer in alleviating the accumulated local inductive biases of convolutional operations in diffusion probabilistic models, experiments are conducted on the AMOS22 dataset and BTCV dataset. Experimental results demonstrate that eliminating local inductive bias at a finer granularity significantly improves the segmentation performance of diffusion probabilistic models. Furthermore, the results confirm that the finer the granularity of bias elimination, the better the segmentation performance.

7.
Neurotoxicology ; 103: 310-319, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-39004286

RESUMEN

Isoflurane is one of the most commonly used anaesthetic agents in surgery procedures. During the past decades, isoflurane has been found to cause impairment in neurological capabilities in new-borns and elderly patients. Luteolin is a flavonoid that has been documented to possess a neuroprotective effect. Here we investigated the putative neuroprotective effects of luteolin on isoflurane-induced neurotoxicity in mouse hippocampal neuronal HT22 cells and explored the potential mechanisms. We demonstrated that luteolin improved mitochondrial dysfunction and reduced oxidative stress and apoptosis in isoflurane-treated HT22 cells, and thus inhibiting the isoflurane-induced neuronal injury. Further investigations showed that isoflurane exposure caused miR-214 downregulation, which could be mitigated by treatment with luteolin. Knockdown of miR-214 attenuated the neuroprotection of luteolin on isoflurane-induced neuronal injury. More importantly, luteolin inhibited isoflurane-caused regulation of the PTEN/Akt pathway, while miR-214 knockdown altered the regulatory effect of luteolin on the PTEN/Akt pathway. Furthermore, the effects of miR-214 knockdown on the neuroprotection of luteolin could also be prevented by knockdown of PTEN, implying that the neuroprotective effect of luteolin was mediated by miR-214/PTEN/Akt signaling pathway. These findings provided evidence for the potential application of luteolin in preventing isoflurane-induced neurotoxicity.


Asunto(s)
Hipocampo , Isoflurano , Luteolina , MicroARNs , Neuronas , Fármacos Neuroprotectores , Fosfohidrolasa PTEN , Proteínas Proto-Oncogénicas c-akt , Transducción de Señal , Animales , Isoflurano/toxicidad , Isoflurano/farmacología , Fosfohidrolasa PTEN/metabolismo , Luteolina/farmacología , Ratones , Proteínas Proto-Oncogénicas c-akt/metabolismo , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Neuronas/efectos de los fármacos , Neuronas/metabolismo , MicroARNs/metabolismo , Fármacos Neuroprotectores/farmacología , Transducción de Señal/efectos de los fármacos , Línea Celular , Estrés Oxidativo/efectos de los fármacos , Apoptosis/efectos de los fármacos
8.
Molecules ; 29(14)2024 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-39064981

RESUMEN

In this study, a new polyionic polymer inhibitor, TIL-NH2, was developed to address the instability of shale gas horizontal wells caused by water-based drilling fluids. The structural characteristics and inhibition effects of TIL-NH2 on mud shale were comprehensively analyzed using infrared spectroscopy, NMR spectroscopy, contact angle measurements, particle size distribution, zeta potential, X-ray diffraction, thermogravimetric analysis, and scanning electron microscopy. The results demonstrated that TIL-NH2 significantly enhances the thermal stability of shale, with a decomposition temperature exceeding 300 °C, indicating excellent high-temperature resistance. At a concentration of 0.9%, TIL-NH2 increased the median particle size of shale powder from 5.2871 µm to over 320 µm, effectively inhibiting hydration expansion and dispersion. The zeta potential measurements showed a reduction in the absolute value of illite's zeta potential from -38.2 mV to 22.1 mV at 0.6% concentration, highlighting a significant decrease in surface charge density. Infrared spectroscopy and X-ray diffraction confirmed the formation of a close adsorption layer between TIL-NH2 and the illite surface through electrostatic and hydrogen bonding, which reduced the weakly bound water content to 0.0951% and maintained layer spacing of 1.032 nm and 1.354 nm in dry and wet states, respectively. Thermogravimetric analysis indicated a marked reduction in heat loss, particularly in the strongly bound water content. Scanning electron microscopy revealed that shale powder treated with TIL-NH2 exhibited an irregular bulk shape with strong inter-particle bonding and low hydration degree. These findings suggest that TIL-NH2 effectively inhibits hydration swelling and dispersion of shale through the synergistic effects of cationic imidazole rings and primary amine groups, offering excellent temperature and salt resistance. This provides a technical foundation for the low-cost and efficient extraction of shale gas in horizontal wells.

9.
J Hazard Mater ; 476: 135181, 2024 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-39003806

RESUMEN

Dissemination of antibiotic resistance genes (ARGs) has become a critical threat to public health. Activated sludge, rich in extracellular polymeric substances (EPS), is an important pool of ARGs. In this study, mechanisms of conjugation transfer of ARGs induced by EPS, including tightly bound EPS (TBEPS), soluble EPS (SEPS), and loosely bound EPS (LBEPS), were explored in terms of molecular diversities and electron transfer properties of EPS. Conjugation transfer frequency was increased by 9.98-folds (SEPS), 4.21-folds (LBEPS), and 15.75-folds (TBEPS) versus the control, respectively. Conjugation-related core genes involving SOS responses (9 genes), membrane permeability (18 genes), intercellular contact (17 genes), and energy metabolism pathways (13 genes) were all upregulated, especially in the presence of TBEPS. Carbohydrates and aliphatic substances in SEPS and LBEPS were contributors to ARG transfer, via influencing reactive oxygen species (ROS) formation (SEPS) and ROS and adenosine triphosphate (ATP) production (LBEPS). TBEPS had the highest redox potential and greatest lability and facilitated electron transfer and alternated respiration between cells, thus promoting ARG transfer by producing ATP. Generally, the chemical molecular characteristics and redox properties of EPS facilitated ARG transfer mainly by influencing lipid peroxidation and ATP, respectively.


Asunto(s)
Matriz Extracelular de Sustancias Poliméricas , Matriz Extracelular de Sustancias Poliméricas/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Transporte de Electrón/efectos de los fármacos , Aguas del Alcantarillado/microbiología , Conjugación Genética , Genes Bacterianos/efectos de los fármacos , Farmacorresistencia Microbiana/genética , Adenosina Trifosfato/metabolismo
10.
Phytochemistry ; 225: 114193, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38908463

RESUMEN

Lathyrisone A (1), a diterpene with an undescribed tricyclic 6/6/6 fused carbon skeleton, along with spirolathyrisins B-D (3-5), three diterpenes with a rare [4.5.0] spirocyclic carbon skeleton, and one known compound (2) were isolated from the roots of Euphorbia lathyris. Their chemical structures were characterized by extensive spectroscopic analysis, X-ray crystallography, ECD and quantum chemistry calculation. A plausible biosynthetic pathway for compounds 1-5 was proposed, which suggested it is a competitive pathway for ingenol biosynthesis in the plant. The anti-fungal activities of these compounds were tested, especially, compound 2 showed stronger anti-fungal activities against Fusarium oxysporum and Alternaria alternata than the positive control fungicide thiophanate-methyl. The preliminary structure-activity relationship of compounds 1-5 was also discussed. These results not only expanded the chemical diversities of E. lathyris, but also provided a lead compound for the control of plant pathogens.


Asunto(s)
Alternaria , Antifúngicos , Diterpenos , Euphorbia , Fusarium , Pruebas de Sensibilidad Microbiana , Raíces de Plantas , Euphorbia/química , Diterpenos/química , Diterpenos/farmacología , Diterpenos/aislamiento & purificación , Raíces de Plantas/química , Antifúngicos/farmacología , Antifúngicos/química , Antifúngicos/aislamiento & purificación , Relación Estructura-Actividad , Fusarium/efectos de los fármacos , Alternaria/efectos de los fármacos , Estructura Molecular , Descubrimiento de Drogas , Cristalografía por Rayos X , Relación Dosis-Respuesta a Droga
11.
Chemistry ; : e202400963, 2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-38923685

RESUMEN

The development of innovative methods for synthesizing silylcyclopentene compounds is particularly important for enriching and improving the synthetical toolbox of organosilicon compounds. Herein, a facile approach has been developed for the synthesis of silylcyclopentenes promoted by mechanochemically generated organolithium species as silicon nucleophiles under ball milling conditions, avoiding the requirement of large amounts of bulk solvent. This operationally simple method demonstrates good functional group compatibility, which provides a great opportunity for further exploration of the synthetic applications of silylcyclopentenes. Density functional theory calculations indicated that the transient lithiosilole intermediates undergo a stepwise nucleophilic addition process, which governs this mechanic-force-promoted [4+1] cycloaddition reaction.

12.
PLoS One ; 19(6): e0304977, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38917082

RESUMEN

The mental health challenges among Chinese college students have become a pressing social concern. This study examined the relationship between parental support for exercise and depression among freshmen and also explored the mediating role of physical exercise and physical self-esteem. Utilizing the Parental Exercise Support Scale, Depression Self-Rating Scale, Physical Activity Rating Scale, and Physical Self-Esteem Scale, a questionnaire survey was conducted. Convenient samples from two universities were recruited by university teachers, which included 766 university freshmen. Correlation and linear regression analyses were employed to assess the overall associations while bootstrapping method was used to test mediation effects. Results indicated significant correlations between parental support for exercise and physical exercise, physical self-esteem, and depression. Physical exercise and physical self-esteem were found to mediate the relationship between parental support for exercise and depression, both individually and sequentially. These findings highlight the potential association between parental support for exercise and the mental health of college freshmen and also offer a mechanism to understand this association.


Asunto(s)
Depresión , Ejercicio Físico , Autoimagen , Humanos , Ejercicio Físico/psicología , Femenino , Masculino , Depresión/psicología , Adulto Joven , Estudiantes/psicología , Encuestas y Cuestionarios , Adulto , Padres/psicología , Universidades , Adolescente , Apoyo Social
13.
J Org Chem ; 89(14): 10379-10383, 2024 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-38923888

RESUMEN

Herein we present a catalytic cross-coupling strategy between C-radicals and Si-radicals, enabling the efficient, gentle, and versatile synthesis of dibenzylic silanes from para-quinone methides and silanecarboxylic acids as the stable silyl radical precursors. The reaction is facilitated by an inexpensive organophotocatalyst and exhibits broad compatibility with various electron-donating and electron-withdrawing functional groups. Notably, mechanistic investigations suggest the involvement of dibenzylic and silyl radicals, underscoring a novel radical coupling mechanism that introduces a fresh perspective on C-Si bond formation.

14.
Spine (Phila Pa 1976) ; 49(15): E229-E238, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-38721831

RESUMEN

STUDY DESIGN: Finite element analysis. OBJECTIVE: To investigate the biomechanical effect of four posterior fixation techniques on stability and adjacent segment degeneration in treating thoracolumbar burst fractures with osteoporosis. SUMMARY OF BACKGROUND DATA: In terms of stability and adjacent segment degeneration, there remains no consensus or guidelines on the optimal technique for the treatment of thoracolumbar burst fractures in patients with osteoporosis. MATERIALS AND METHODS: Images of CT scans were imported into MIMICS and further processed by Geomagic to build three-dimensional models of the T10-L5 region. A v-shaped osteotomy was performed on the L1 vertebral body to simulate a burst fracture in the setting of osteoporosis. Subsequently, four fixation techniques were designed using SolidWorks software. Range of motion (ROM) of the global spine, ROM distribution, ROM of adjacent segment, Von Mises stress on adjacent intervertebral disks, and facet joints were analyzed. RESULTS: Among the four groups, the cortical bone screw fixation (CBT) showed the highest global ROM at 1.86°, while long-segmented pedicle screw fixation (LSPS) had the lowest global ROM at 1.25°. The LSPS had the smallest percentage of ROM of fractured vertebral body to fixed segment at 75.04%, suggesting the highest stability after fixation. The maximum ROM of the adjacent segment was observed in the CBT at 1.32°, while the LSPS exhibited the smallest at 0.89°. However, the LSPS group experienced larger maximum stress on the adjacent intervertebral disks (9.60 MPa) and facet joints (3.36 MPa), indicating an increasing risk of adjacent segment disease. CONCLUSION: LSPS provided the greatest stability, while CBT provided the smallest amount of stability. However, the elevated stress on adjacent intervertebral disks and facet joints after LSPS fixation increased the possibility of adjacent segment degeneration. Cement-augmented pedicle screw fixation (CAPS) and combined cortical bone screw and pedicle screw fixation (CBT-PS) demonstrated significant biomechanical advantages in providing moderate fixation strength while reducing stress on the intervertebral disks and facet joints.


Asunto(s)
Análisis de Elementos Finitos , Fijación Interna de Fracturas , Vértebras Lumbares , Osteoporosis , Fracturas de la Columna Vertebral , Vértebras Torácicas , Humanos , Vértebras Torácicas/cirugía , Vértebras Torácicas/lesiones , Vértebras Torácicas/diagnóstico por imagen , Vértebras Lumbares/cirugía , Vértebras Lumbares/lesiones , Vértebras Lumbares/diagnóstico por imagen , Fracturas de la Columna Vertebral/cirugía , Fracturas de la Columna Vertebral/diagnóstico por imagen , Fenómenos Biomecánicos , Fijación Interna de Fracturas/métodos , Osteoporosis/cirugía , Osteoporosis/complicaciones , Rango del Movimiento Articular , Tornillos Pediculares , Masculino , Persona de Mediana Edad
15.
Inflammopharmacology ; 32(4): 2153-2175, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38761314

RESUMEN

Cancer, a chronic disease characterized by uncontrolled cell development, kills millions of people globally. The WHO reported over 10 million cancer deaths in 2020. Anticancer medications destroy healthy and malignant cells. Cancer treatment induces neuropathy. Anticancer drugs cause harm to spinal cord, brain, and peripheral nerve somatosensory neurons, causing chemotherapy-induced neuropathic pain. The chemotherapy-induced mechanisms underlying neuropathic pain are not fully understood. However, neuroinflammation has been identified as one of the various pathways associated with the onset of chemotherapy-induced neuropathic pain. The neuroinflammatory processes may exhibit varying characteristics based on the specific type of anticancer treatment delivered. Neuroinflammatory characteristics have been observed in the spinal cord, where microglia and astrocytes have a significant impact on the development of chemotherapy-induced peripheral neuropathy. The patient's quality of life might be affected by sensory deprivation, loss of consciousness, paralysis, and severe disability. High cancer rates and ineffective treatments are associated with this disease. Recently, histone deacetylases have become a novel treatment target for chemotherapy-induced neuropathic pain. Chemotherapy-induced neuropathic pain may be treated with histone deacetylase inhibitors. Histone deacetylase inhibitors may be a promising therapeutic treatment for chemotherapy-induced neuropathic pain. Common chemotherapeutic drugs, mechanisms, therapeutic treatments for neuropathic pain, and histone deacetylase and its inhibitors in chemotherapy-induced neuropathic pain are covered in this paper. We propose that histone deacetylase inhibitors may treat several aspects of chemotherapy-induced neuropathic pain, and identifying these inhibitors as potentially unique treatments is crucial to the development of various chemotherapeutic combination treatments.


Asunto(s)
Antineoplásicos , Inhibidores de Histona Desacetilasas , Neuralgia , Neuralgia/tratamiento farmacológico , Neuralgia/inducido químicamente , Humanos , Inhibidores de Histona Desacetilasas/farmacología , Animales , Antineoplásicos/efectos adversos , Neoplasias/tratamiento farmacológico , Calidad de Vida
16.
Med Biol Eng Comput ; 2024 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-38727759

RESUMEN

In clinical practice, the morphology of the left atrial appendage (LAA) plays an important role in the selection of LAA closure devices for LAA closure procedures. The morphology determination is influenced by the segmentation results. The LAA occupies only a small part of the entire 3D medical image, and the segmentation results are more likely to be biased towards the background region, making the segmentation of the LAA challenging. In this paper, we propose a lightweight attention mechanism called fusion attention, which imitates human visual behavior. We process the 3D image of the LAA using a method that involves overview observation followed by detailed observation. In the overview observation stage, the image features are pooled along the three dimensions of length, width, and height. The obtained features from the three dimensions are then separately input into the spatial attention and channel attention modules to learn the regions of interest. In the detailed observation stage, the attention results from the previous stage are fused using element-wise multiplication and combined with the original feature map to enhance feature learning. The fusion attention mechanism was evaluated on a left atrial appendage dataset provided by Liaoning Provincial People's Hospital, resulting in an average Dice coefficient of 0.8855. The results indicate that the fusion attention mechanism achieves better segmentation results on 3D images compared to existing lightweight attention mechanisms.

17.
J Phys Chem Lett ; 15(19): 5150-5158, 2024 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-38712816

RESUMEN

Intrinsic boundaries formed by grain stacks of randomly oriented perovskite crystallites seriously restrict charge transport in the resultant photovoltaic devices, whereas direct passivation of these defects remains unexplored, and it is desirable to modulate perovskite growth with uniform orientation. Herein, we report a simple but effective method to regulate perovskite crystallization by employing a volatile and polymerizable monomer of hydroxyethyl methacrylate (HEMA), which can simultaneously interact with both FA+ and Pb2+ via hydrogen and coordination bonding, respectively, to seed perovskite crystallization with accelerated nucleation and retarded crystal growth. Upon thermal annealing, the gradual volatilization and partial self-condensation of the HEMA drive the perovskite growth perpendicularly to the substrate, leading to largely suppressed defect states, improved crystallinity, and a reduced Young's modulus of the perovskite film. As a result, champion efficiencies exceeding 24 and 22% with improved operational and mechanical stability of the optimized perovskite solar cells based on rigid and flexible substrates were finally achieved.

18.
Small ; : e2401624, 2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38773869

RESUMEN

The poor machinability of halide perovskite crystals severely hampered their practical applications. Here a high-throughput growth method is reported for armored perovskite single-crystal fibers (SCFs). The mold-embedded melt growth (MEG) method provides each SCF with a capillary quartz shell, thus guaranteeing their integrality when cutting and polishing. Hundreds of perovskite SCFs, exemplified by CsPbBr3, CsPbCl3, and CsPbBr2.5I0.5, with customized dimensions (inner diameters of 150-1000 µm and length of several centimeters), are grown in one batch, with all the SCFs bearing homogeneity in shape, orientation, and optical/electronic properties. Versatile assembly protocols are proposed to directly integrate the SCFs into arrays. The assembled array detectors demonstrated low-level dark currents (< 1 nA) with negligible drift, low detection limit (< 44.84 nGy s-1), and high sensitivity (61147 µC Gy-1 cm-2). Moreover, the SCFs as isolated pixels are free of signal crosstalk while showing uniform X-ray photocurrents, which is in favor of high spatial resolution X-ray imaging. As both MEG and the assembly of SCFs involve none sophisticated processes limiting the scalable fabrication, the strategy is considered to meet the preconditions of high-throughput productions.

19.
Biomed Chromatogr ; 38(7): e5894, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38777624

RESUMEN

Verbena officinalis L. as a medical plant has been used to treat many diseases. However, the quality control underlying V. officinalis remains to be studied. HPLC fingerprint analysis and the qualitative and quantitative analysis of water extract from V. officinalis were carried out, and it was found that the quality varies according to habitat and batch. Verbenalin could be a crucial component in the quality evaluation of V. officinalis. This study contributes to better understanding of quality control for V. officinalis.


Asunto(s)
Extractos Vegetales , Verbena , Cromatografía Líquida de Alta Presión/métodos , Extractos Vegetales/química , Extractos Vegetales/análisis , Verbena/química , Reproducibilidad de los Resultados , Espectrometría de Masas/métodos , Modelos Lineales , Límite de Detección , Cromatografía Líquida con Espectrometría de Masas
20.
Small ; 20(32): e2401489, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38661053

RESUMEN

To mitigate the environmental impact of the improper disposal of spent LiFePO4 batteries and reduce resource waste, the development of LiFePO4 recycling technologies is of paramount importance. Meanwhile, olivine-structured NaFePO4 in sodium-ion batteries has received great attention, due to its high theoretical specific capacity of 154 mAh g-1 and excellent stability. However, olivine NaFePO4 only can be synthesized from olivine LiFePO4. Accordingly, in this proposal, developing the continuous flow electrochemical solid-liquid reactor-based metal ion insertion technology is to utilize the olivine FePO4, recycled from LiFePO4, and to synthesize NaFePO4. Additionally, by employing I- as the reducing agent, NaFePO4 is successfully synthesized with a discharge-specific capacity of 134 mAh g-1 at 0.1C and a remarkable capacity retention rate of 86.5% after 100 cycles at 0.2C. And the reasons for sodium deficiency in the synthesized NFP are elucidated through first-principles calculations. Furthermore, the kinetics of the solid-solution reaction 2 (Na2/3+ßPO4→ Na1-αFePO4) mechanism improve with cycling and are sensitive to temperature. Utilizing a minimal amount of reducing agent in the electrochemical reactor, NaFePO4 synthesis is successfully achieved. This innovative approach offers a new, cost-effective, and environmentally friendly strategy for preparing NaFePO4 from recycling LiFePO4.

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