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1.
J Am Chem Soc ; 146(14): 9709-9720, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38546406

RESUMO

Chemically modifying monolayer two-dimensional transition metal dichalcogenides (TMDs) with organic molecules provides a wide range of possibilities to regulate the electronic and optoelectronic performance of both materials and devices. However, it remains challenging to chemically attach organic molecules to monolayer TMDs without damaging their crystal structures. Herein, we show that the Mo atoms of monolayer MoS2 (1L-MoS2) in defect states can coordinate with both catechol and 1,10-phenanthroline (Phen) groups, affording a facile route to chemically modifying 1L-MoS2. Through the design of two isomeric molecules (LA2 and LA5) comprising catechol and Phen groups, we show that attaching organic molecules to Mo atoms via coordinative bonds has no negative effect on the crystal structure of 1L-MoS2. Both theoretical calculation and experiment results indicate that the coordinative strategy is beneficial for (i) repairing sulfur vacancies and passivating defects; (ii) achieving a long-term and stable n-doping effect; and (iii) facilitating the electron transfer. Field effect transistors (FETs) based on the coordinatively modified 1L-MoS2 show high electron mobilities up to 120.3 cm2 V-1 s-1 with impressive current on/off ratios over 109. Our results indicate that coordinatively attaching catechol- or Phen-bearing molecules may be a general method for the nondestructive modification of TMDs.

2.
Cancer Sci ; 2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-39013843

RESUMO

In our previous study, we found that small ubiquitin-related modifier (SUMO)-activating enzyme ubiquitin-associated-2 domain (UBA2) was upregulated in hepatocellular carcinoma (HCC) patients who were insensitive to chemoembolization. In this study, we aimed to investigate the role of UBA2 in HCC progression. Three cohorts were used to evaluate the efficacy of UBA2 as a prognostic factor for HCC. Our results indicated that UBA2 was associated with aggressive clinical behaviors and was a strong indicator of poor prognosis in HCC. In vitro experiments demonstrated that UBA2 accelerated cell growth, invasion, and migration. These results were further supported by in vivo experiments. RNA-sequencing analysis indicated NQO1 as a target of UBA2, with its levels altering following UBA2 manipulation. The results were verified by western blotting (WB) and quantitative PCR. The SUMOplot Analysis Program predicted lysine residue K240 as a modification target of UBA2, which was confirmed by immunoprecipitation (IP) assays. Subsequent mutation of NQO1 at K240 in HCC cell lines and functional assays revealed the significance of this modification. In addition, the oncogenic effect of UBA2 could be reversed by the SUMO inhibitor ML792 in vivo and in vitro. In conclusion, our study elucidated the regulatory mechanism of UBA2 in HCC and suggested that the SUMO inhibitor ML792 may be an effective combinatory treatment for patients with aberrant UBA2 expression.

3.
Expert Rev Proteomics ; 21(1-3): 115-123, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38372668

RESUMO

INTRODUCTION: Around 20% of individuals diagnosed with acute pancreatitis (AP) may develop severe acute pancreatitis (SAP), possibly resulting in a mortality rate ranging from 15% to 35%. There is an urgent need to thoroughly understand the molecular phenotypes of SAP resulting from diverse etiologies. The field of translational research on AP has seen the use of several innovative proteomic methodologies via the ongoing improvement of isolation, tagging, and quantification methods. AREAS COVERED: This paper provides a comprehensive overview of differentially abundant proteins (DAPs) identified in AP by searching the PubMed/MEDLINE database (2003-2023) and adds significantly to the current theoretical framework. EXPERT OPINION: DAPs for potentially diagnosing AP based on proteomic identification need to be confirmed by multi-center studies that include larger samples. The discovery of DAPs in various organs at different AP stages via proteomic technologies is essential better to understand the pathophysiology of AP-related multiple organ dysfunction syndrome. Regarding the translational research of AP, novel approaches like single-cell proteomics and imaging using mass spectrometry may be used as soon as they become available.


Assuntos
Pancreatite , Humanos , Pancreatite/diagnóstico , Pancreatite/complicações , Pancreatite/metabolismo , Proteômica , Doença Aguda , Insuficiência de Múltiplos Órgãos
4.
Langmuir ; 40(20): 10776-10791, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38728176

RESUMO

Fractured reservoirs are an important source of oil and gas energy. After depletion of production, the production capacity of this reservoir decreases rapidly. Effective profile control is needed to improve the sweep efficiency and reservoir heterogeneity. Foam can solve such problems, but its profile control mechanism is not fully understood. Based on this, this paper uses the level set method to study the microscale control mechanism of foam in fractured media. The results show that artificial fractures and high-permeability microfractures are tighter than natural fractures, the Jamin effect of foam is stronger, and the secondary foaming ability is better. Therefore, the plugging ability of foam to natural fractures is far less than that of foam to artificial fractures and high-permeability microfractures. The larger the fracture opening, the larger the foam volume and the smaller the flow rate. As the opening ratio increases gradually, the generated foam flows more to the natural fractures with a large opening, and the effect of foam blocking large fractures becomes worse. The diversion rate curves of different opening ratios show that the foam has a good profile control effect when the opening ratios are 4:1 and 2:1, and even the diversion rate overturns, while the profile control diversion effect is poor when the opening ratio is 10:1, so it cannot play an effective role in profile control. The foam shows the profile control process of preferentially plugging the high-permeability area and allowing more subsequent fluids to enter the low-permeability area. The research reveals the profile control mechanism of foam on fractured reservoirs from the micro level, which is the supplement and verification of relevant macro research and provides a theoretical basis for the efficient development of fractured reservoirs.

5.
Inorg Chem ; 63(10): 4691-4696, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38394615

RESUMO

In this study, four isostructural pillar-layered frameworks were constructed using a porphyrin layer and an anthracene pillar, which served as the sensitizer and annihilator, respectively, in the triplet-triplet annihilation upconversion (TTA-UC) system. Framework 1 demonstrated the highest upconversion quantum yield of 1.01%. Additionally, 1 and 2 also exhibited down-conversion fluorescence resulting from the porphyrin component. A twist intramolecular charge transfer (TICT) state was observed in the bianthracene chromophore of 2, resulting in transient rotation of two anthracene rings and red-shifted emission. Both computational studies and experiments confirmed the transition from a locally excited state to a TICT state upon the inclusion of polar guest molecules into the framework.

6.
J Chem Phys ; 160(20)2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38804490

RESUMO

Understanding the dynamics of excited-state vibrational energy relaxation in photosynthetic pigments is crucial for elucidating the mechanisms underlying energy transfer processes in light-harvesting complexes. Utilizing advanced femtosecond broadband transient fluorescence (TF) spectroscopy, we explored the excited-state vibrational dynamics of Chlorophyll-a (Chl-a) both in solution and within the light-harvesting complex II (LHCII). We discovered a vibrational cooling (VC) process occurring over ∼6 ps in Chl-a in ethanol solution following Soret band excitation, marked by a notable ultrafast TF blueshift and spectral narrowing. This VC process, crucial for regulating the vibronic lifetimes, was further elucidated through the direct observation of the population dynamics of higher vibrational states within the Qy electronic state. Notably, Chl-a within LHCII demonstrated significantly faster VC dynamics, unfolding within a few hundred femtoseconds and aligning with the ultrafast energy transfer processes observed within the complex. Our findings shed light on the complex interaction between electronic and vibrational states in photosynthetic pigments, underscoring the pivotal role of vibrational dynamics in enabling efficient energy transfer within light-harvesting complexes.

7.
Artigo em Inglês | MEDLINE | ID: mdl-38639618

RESUMO

Objective: This study aims to investigate the clinical efficacy of biomimetic physiotherapy combined with manipulation therapy in the management of female myofascial pelvic pain syndrome (MPPS). Methods: A total of 120 patients diagnosed with MPPS at our hospital from June 2018 to June 2021 were included. All patients had a history of sexual activity, met the diagnostic criteria for female chronic pelvic pain, and exhibited pelvic floor muscle and myofascial trigger points in gynecological examinations. Based on treatment methods, patients were categorized into a control group (n=64, treated with biomimetic physiotherapy) and an experimental group (n=56, treated with biomimetic physiotherapy plus manipulation therapy). Pre- and post-treatment assessments in both groups included pelvic floor muscle surface electromyogram, Visual Analogue Scale (VAS) score, pelvic floor muscle tenderness score, and pelvic floor muscle strength. Results: After treatment, the mean values of pre-resting potential and post-resting potential declined significantly, from (9.58±2.22) to (4.06±0.77) and from (8.18±1.78) to (3.56±0.61), respectively. In the control group, these values decreased from (9.61±2.77) to (3.15±0.58), and in the experimental group, they decreased from (8.16±1.78) to (2.79±0.59). The VAS score exhibited a noteworthy decrease from (6.18±1.00) to (3.15±0.56) in the control group and from (6.20±1.13) to (2.04±0.68) in the experimental group. The pelvic floor muscle tenderness score decreased from (8.14±0.86) to (3.78±0.77) in the control group and from (7.91±1.03) to (1.93±0.80) in the experimental group. Furthermore, the percentage of patients whose pelvic floor muscle strength increased from

8.
J Am Chem Soc ; 145(10): 5769-5777, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36863033

RESUMO

A series of novel surface Ru-H bipyridine complexes-grafted TiO2 nanohybrids were for the first time prepared by a combined procedure of surface organometallic chemistry with post-synthetic ligand exchange for photocatalytic conversion of CO2 to CH4 with H2 as electron and proton donors under visible light irradiation. The selectivity toward CH4 increased to 93.4% by the ligand exchange of 4,4'-dimethyl-2,2'-bipyridine (4,4'-bpy) with the surface cyclopentadienyl (Cp)-RuH complex and the CO2 methanation activity was enhanced by 4.4-fold. An impressive rate of 241.2 µL·g-1·h-1 for CH4 production was achieved over the optimal photocatalyst. The femtosecond transient IR absorption results demonstrated that the hot electrons were fast injected in 0.9 ps from the photoexcited surface 4,4'-bpy-RuH complex into the conduction band of TiO2 nanoparticles to form a charge-separated state with an average lifetime of ca. 50.0 ns responsible for the CO2 methanation. The spectral characterizations indicated clearly that the formation of CO2•- radicals by single electron reduction of CO2 molecules adsorbed on surface oxygen vacancies of TiO2 nanoparticles was the most critical step for the methanation. Such radical intermediates were inserted into the explored Ru-H bond to generate Ru-OOCH species and finally CH4 and H2O in the presence of H2.

9.
Small ; 19(28): e2301731, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37173815

RESUMO

The commercialization of high-energy Li-metal batteries is impeded by Li dendrites formed during electrochemical cycling and the safety hazards it causes. Here, a novel porous copper current collector that can effectively mitigate the dendritic growth of Li is reported. This porous Cu foil is fabricated via a simple two-step electrochemical process, where Cu-Zn alloy is electrodeposited on commercial copper foil and then Zn is electrochemically dissolved to form a 3D porous structure of Cu. The 3D porous Cu layers on average have a thickness of ≈14 um and porosity of ≈72%. This current collector can effectively suppress Li dendrites in cells cycled with a high areal capacity of 10 mAh cm-2 and under a high current density of 10 mA cm-2 . This electrochemical fabrication method is facile and scalable for mass production. Results of advanced in situ synchrotron X-ray diffraction reveal the phase evolution of the electrochemical deposition and dealloying processes.

10.
Small ; 19(8): e2206167, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36504426

RESUMO

Broadband infrared (IR) absorption is sought after for wide range of applications. Graphene can support IR plasmonic waves tightly bound to its surface, leading to an intensified near-field. However, the excitation of graphene plasmonic waves usually relies on resonances. Thus, it is still difficult to directly obtain both high near-field intensity and high absorption rate in ultra-broad IR band. Herein, a novel method is proposed to directly realize high near-field intensity in broadband IR band by graphene coated manganous oxide microwires featured hierarchical nanostructures (HNSs-MnO@Gr MWs) both experimentally and theoretically. Both near-field intensity and IR absorption of HNSs-MnO@Gr MWs are enhanced by at least one order of magnitude compared to microwires with smooth surfaces. The results demonstrate that the HNSs-MnO@Gr MWs support vibrational sensing of small organic molecules, covering the whole fingerprint region and function group region. Compared with the graphene-flake-based enhancers, the signal enhancement factors reach a record high of 103 . Furthermore, just a single HNSs-MnO@Gr MW can be constructed to realize sensitively photoresponse with high responsivity (over 3000 V W-1 ) from near-IR to mid-IR. The graphene coated dielectric hierarchical micro/nanoplatform with enhanced near-field intensity is scalable and can harness for potential applications including spectroscopy, optoelectronics, and sensing.

11.
Mol Carcinog ; 62(12): 1846-1859, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37589421

RESUMO

Pulmonary lymphoepithelioma-like carcinoma (pLELC) is a rare malignancy that lacks specific biomarkers. N6-methyladenosine (m6 A) is the most widespread internal modification of messenger RNA (mRNA), and its dysregulation is involved in the development of many cancers. However, the expression of m6 A genes in pLELC and their roles are unknown. We obtained an exosomal transcriptome data set of patients diagnosed with pLELC and healthy controls using RNA sequencing and identified differentially expressed genes (DEGs) in the two groups using R software. The differential expression of the 37 m6 A genes in the two sets of samples was further analyzed, and receiver operating characteristic (ROC) curves were plotted for each gene to identify their grouping ability. The STRING database was used to construct a protein-protein interaction network for m6 A genes. An mRNA-miRNA regulatory network of m6 A-related DEGs was constructed using the miRNet database, and a prediction score formula was established. A nomogram was constructed based on the candidate m6 A genes and prediction scores. The expression of key genes was determined through the immunohistochemical (IHC) staining of clinical tissue sections. Using ROC curves, nine m6 A genes were revealed to have classification efficacy in both groups of samples. We screened seven m6 A-related DEGs (MAN2C1, HNRNPCL1, FUS, EIF6, DIP2A, COA3, and BUD13) that were beneficial for grouping and constructed nomogram models. Through IHC, we identified FUS and EIF6 as being possibly involved in the occurrence and development of pLELC. The m6 A gene expression patterns in pLELC-derived exosomes were significantly different from those in healthy controls. We screened several key genes to facilitate the development of diagnostic markers for pulmonary lymphoepithelioma.


Assuntos
Carcinoma de Células Escamosas , Humanos , Metilação , Perfilação da Expressão Gênica , Transcriptoma , Adenosina/genética , RNA Mensageiro/genética
12.
J Med Virol ; 95(12): e29272, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-38054501

RESUMO

The impact of severe acute respiratory syndrome coronavirus 2 infection on the potential development of pancreatitis is a subject of ongoing debate within academic discourse. Establishing a causal link between COVID-19 and pancreatitis may not be fully supported by relying only on retrospective studies or case reports. This study examined the relationship between COVID-19 phenotypes and pancreatitis by Mendelian randomization (MR) method. The identification of instrumental variables (single nucleotide polymorphisms) that exhibit a robust association with the COVID-19 phenotypes was accomplished through a meticulous process of rigorous screening procedures. We included acute pancreatitis and chronic pancreatitis (CP) as the outcomes in the MR analysis, even though no definitive studies exist between COVID-19 and CP. A direct causal relationship between genetically predicted COVID-19 phenotypes and pancreatitis risk cannot be established. There is an ongoing debate over the designation of COVID-19 as a definitive cause of pancreatitis.


Assuntos
COVID-19 , Pancreatite , Humanos , Doença Aguda , COVID-19/complicações , Estudo de Associação Genômica Ampla , Fenótipo , Polimorfismo de Nucleotídeo Único , Estudos Retrospectivos , Análise da Randomização Mendeliana
13.
Opt Express ; 31(18): 29019-29036, 2023 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-37710710

RESUMO

Designing freeform optics with high degrees of freedom can improve their optical performances; however, there are high requirements for controlling the surface shapes of such optics. Optical designers need to add constraints to the optimization process and make repeated adjustments to ensure the manufacturability of these shapes; this process is cumbersome and relies heavily on the experience of the designer. In this study, an automatic control method for freeform surface shapes is proposed. By adding an outer loop to the optimization process, the principal curvature and sag departure of the sampling points are gradually controlled during the optimization cycle based on the system requirements and surface evaluation results. The method was implemented in CODE V and successfully applied to a design example in freeform prism optics.

14.
BMC Cancer ; 23(1): 841, 2023 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-37684569

RESUMO

BACKGROUND: Breast cancers with 1-10% cell staining for estrogen receptor (ER) present particular clinical features. The clinical data of estrogen receptor expression level and treatment effect are limited, particularly regarding chemotherapy benefit. We evaluated the pathologic response to neoadjuvant chemotherapy (NAC) in ER low positive tumors (ER staining 1-10%) and compared it with ER > 10% positive tumors (ER staining > 10%) and ER-negative tumors. We further explored the differences in recurrence and survival with respect to the ER expression level. METHOD: Patients with stages II and III HER2-negative primary breast cancer who received neoadjuvant chemotherapy followed by definitive surgery were categorized according to their ER percentages into three groups: ER-negative, ER low positive, and ER > 10% positive. Logistic regression models were used to assess the association between each variable and pathologic complete response (pCR). Kaplan‒Meier analysis was used to estimate survival outcomes. Cox models were used to adjust for patient and tumor characteristics. RESULTS: A total of 241 patients were analyzed. Of all patients included, 22 (9.1%) had ER low positive tumors, 159 (66.0%) had ER > 10% positive tumors, and 60 (24.9%) were ER-negative. Low ER positivity was significantly associated with a higher pCR rate than ER > 10% positivity (OR, 0.249; 95% CI, 0.067-0.923; P = 0.038). After a median follow-up time of 32 months, the disease-free survival (DFS) and overall survival (OS) of the patients with ER low positive tumors were significantly worse than those of the patients with ER > 10% positive tumors but similar to those with ER-negative tumors. After adjustment for covariates, ER low positive tumors were significantly associated with worse DFS than ER > 10% positive tumors. CONCLUSION: Our results indicated that ER low positive breast cancer presents a better response to neoadjuvant chemotherapy and significantly worse prognosis for patients than those with ER > 10% positive tumors, but similar to the ER-negative group. These data support that this category of patients behaves clinically like patients with ER-negative breast cancer and should be treated differently from patients with ER > 10% positive tumors. Further prospective study is needed.


Assuntos
Neoplasias da Mama , Humanos , Feminino , Neoplasias da Mama/tratamento farmacológico , Receptores de Estrogênio , Terapia Neoadjuvante , Prognóstico , Intervalo Livre de Doença
15.
Cell Commun Signal ; 21(1): 207, 2023 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-37587491

RESUMO

Keloids are a fibroproliferative skin disorder that develops in people of all ages. Keloids exhibit some cancer-like behaviors, with similar genetic and epigenetic modifications in the keloid microenvironment. The keloid microenvironment is composed of keratinocytes, fibroblasts, myofibroblasts, vascular endothelial cells, immune cells, stem cells and collagen fibers. Recent advances in the study of keloids have led to novel insights into cellular communication among components of the keloid microenvironment as well as potential therapeutic targets for treating keloids. In this review, we summarized the nature of genetic and epigenetic regulation in keloid-derived fibroblasts, epithelial-to-mesenchymal transition of keratinocytes, immune cell infiltration into keloids, the differentiation of keloid-derived stem cells, endothelial-to-mesenchymal transition of vascular endothelial cells, extracellular matrix synthesis and remodeling, and uncontrolled angiogenesis in keloids with the aim of identifying new targets for therapeutic benefit. Video Abstract.


Assuntos
Queloide , Humanos , Células Endoteliais , Epigênese Genética , Pele , Queratinócitos
16.
Nanotechnology ; 34(23)2023 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-36877995

RESUMO

In this work, ultrafast carrier dynamics of mechanically exfoliated 1T-TiSe2flakes from the high-quality single crystals with self-intercalated Ti atoms are investigated by femtosecond transient absorption spectroscopy. The observed coherent acoustic and optical phonon oscillations after ultrafast photoexcitation reveal the strong electron-phonon coupling in 1T-TiSe2. The ultrafast carrier dynamics probed in both visible and mid-infrared regions indicate that some photogenerated carriers localize near the intercalated Ti atoms and form small polarons rapidly within several picoseconds after photoexcitation due to the strong and short-range electron-phonon coupling. The formation of polarons leads to a reduction of carrier mobility and a long-time relaxation process of photoexcited carriers for several nanoseconds. The formation and dissociation rates of the photoinduced polarons are dependent on both the pump fluence and the thickness of TiSe2sample. This work offers new insights into the photogenerated carrier dynamics of 1T-TiSe2, and emphasizes the effects of intercalated atoms on the electron and lattice dynamics after photoexcitation.

17.
Environ Sci Technol ; 57(13): 5414-5423, 2023 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-36942728

RESUMO

Due to the growing demands of rare earth elements (REEs) and the vulnerability of REEs to potential supply disruption, there have been increasing interests in recovering REEs from waste streams such as coal fly ash (CFA). Meanwhile, CFA as a large industrial waste stream in the United States (U.S.) poses significant environmental and economic burdens. Recovery of REEs from CFA is a promising solution to the REE scarcity issue and also brings opportunities for CFA management. This study demonstrates a green system for REE recovery from Class F and C CFA that consists of three modules: REE leaching using citrate, REE separation and concentration using oxalate, and zeolite synthesis using secondary wastes from Modules I and II. In Module I, ∼10 and 60% REEs were leached from the Class F and C CFA samples, respectively, using citrate at pH 4. In Module II, the addition of oxalate selectively precipitated and concentrated REEs from the leachate via the formation of weddellite (CaC2O4·2H2O), while other trace metals remained in solution. In Module III, zeolite was synthesized using wastes from Modules I and II. This study is characterized by the successful recovery of REEs and upcycling of secondary wastes, which addresses both REE recovery and CFA management challenges.


Assuntos
Metais Terras Raras , Zeolitas , Cinza de Carvão/química , Carvão Mineral , Citratos , Ácido Cítrico
18.
Appl Opt ; 62(29): 7837-7843, 2023 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-37855494

RESUMO

Ultrashort throw projector (UTP) technology has been a challenging research focus in the fields of large field of view and short-distance projection. In this paper, we propose a design method for a curved-target UTP based on image precorrection. A predistortion method (<1p i x e l) using a radial basis function is presented to effectively correct irregular distortion. A grayscale precorrection method is used to address uneven illumination distribution. We provide a UTP design example and verify the correction methods using two different curved targets (aspherical and freeform), demonstrating effective distortion correction (<1%) and illumination uniformity (>90%). The structure similarity index measure for the projection images shows close or greater than 0.9 correlation.

19.
Sensors (Basel) ; 23(23)2023 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-38067896

RESUMO

Accurate terrain mapping information is very important for foot landing planning and motion control in foot robots. Therefore, a terrain mapping method suitable for an indoor structured environment is proposed in this paper. Firstly, by constructing a terrain mapping framework and adding the estimation of the robot's pose, the algorithm converts the distance sensor measurement results into terrain height information and maps them into the voxel grid, and effectively reducing the influence of pose uncertainty in a robot system. Secondly, the height information mapped into the voxel grid is downsampled to reduce information redundancy. Finally, a preemptive random sample consistency (preemptive RANSAC) algorithm is used to divide the plane from the height information of the environment and merge the voxel grid in the extracted plane to realize the adaptive resolution 2D voxel terrain mapping (ARVTM) in the structured environment. Experiments show that the proposed mapping algorithm reduces the error of terrain mapping by 62.7% and increases the speed of terrain mapping by 25.1%. The algorithm can effectively identify and extract plane features in a structured environment, reducing the complexity of terrain mapping information, and improving the speed of terrain mapping.

20.
Nano Lett ; 22(14): 5651-5658, 2022 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-35786976

RESUMO

Edge states of two-dimensional transition-metal dichalcogenides (TMDCs) are crucial to quantum circuits and optoelectronics. However, their dynamics are pivotal but remain unclear due to the edge states being obscured by their bulk counterparts. Herein, we study the state-resolved transient absorption spectra of ball-milling-produced MoS2 nanosheets with 10 nm lateral size with highly exposed free edges. Electron energy loss spectroscopy and first-principles calculations confirm that the edge states are located in the range from 1.23 to 1.78 eV. Upon above bandgap excitations, excitons populate and diffuse toward the boundary, where the potential gradient blocks excitons and the edge states are formed through interband transitions within 400 fs. With below bandgap excitations, edge states are slowed down to 1.1 ps due to the weakened valence orbital coupling. These results shed light on the fundamental exciton dissociation processes on the boundary of functionalized TMDCs, enabling the ground work for applications in optoelectronics and light-harvesting.

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