RESUMO
A facile and practical protocol to construct 2H-imidazoles by applying an oxime acetate block as the sole component via oxidative homo/cross-coupling catalyzed by Cu(I) was developed. This strategy provides a straightforward method to produce a series of substituted 2H-imidazoles in moderate to excellent yields. The transformation process is straightforward to operate and is considered as a readily available catalytic system exhibiting good substrate compatibility, eliminating the necessity for pre-functionalization of azides or the use of additives.
RESUMO
Pressure-induced topochemical polymerization of molecular crystals with various stackings is a promising way to synthesize materials with different co-existing sub-structures. Here, by compressing the azobenzene crystal containing two kinds of intermolecular stacking, we synthesized an ordered van der Waals carbon nanoribbon (CNR) heterostructure in one step. Azobenzene polymerizes via a [4 + 2] hetero-Diels-Alder (HDA) reaction of phenylazo-phenyl in layer A and a para-polymerization reaction of phenyl in layer B at 18 GPa, as evidenced by in situ Raman and IR spectroscopies, X-ray diffraction, as well as gas chromatography-mass spectrometry and the solid-state nuclear magnetic resonance of the recovered products. The theoretical calculation shows that the obtained CNR heterostructure has a type II (staggered) band gap alignment. Our work highlights a high-pressure strategy to synthesize bulk CNR heterostructures.
RESUMO
OBJECTIVE: The aim of this study was to investigate the role and related mechanism of chordin-like 1 (CHRDL1) in oral squamous cell carcinoma (OSCC). METHODS: The expressions of CHRDL1 were analyzed in both mRNA and protein levels by bioinformatics analysis, immunohistochemistry, and fluorescence in situ hybridization in OSCC. Survival analysis was used to determine the relationship between CHRDL1 and prognosis. In addition, enrichment analysis was used to suggest signal pathways involved in CHRDL1. Besides, the relationships between CHRDL1 and miRNAs, hypoxia, and immune infiltration were explored. RESULTS: The mRNA level of CHRDL1 in OSCC was significantly lower than that in normal tissues, while the protein level was significantly higher than that in normal tissues. The high mRNA levels of CHRDL1 suggested a poor prognosis in patients with OSCC. The enrichment results showed that CHRDL1 might be involved in the Calcium signaling pathway, dilated cardiomyopathy, and focal adhesion. 7 immune cells were positively correlated with CHRDL1, while Tgd was negatively correlated with CHRDL1. In addition, we also found that hsa-miR-455-3p directly targeted CHRDL1 and reduced the mRNA levels of CHRDL1. CONCLUSION: CHRDL1 plays a vital role in promoting cancer in OSCC and is down-regulated at the mRNA levels by hsa-miR-455-3p.
Assuntos
Carcinoma de Células Escamosas , Neoplasias de Cabeça e Pescoço , MicroRNAs , Neoplasias Bucais , Humanos , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Carcinoma de Células Escamosas/patologia , Neoplasias Bucais/patologia , Hibridização in Situ Fluorescente , MicroRNAs/genética , RNA Mensageiro , Neoplasias de Cabeça e Pescoço/genética , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Proliferação de CélulasRESUMO
2,5-Furandicarboxylic acid (FDCA) is one of the top-12 value-added chemicals from sugar. Besides the wide application in chemical industry, here we found that solid FDCA polymerized to form an atomic-scale ordered sp3-carbon nanothread (CNTh) upon compression. With the help of perfectly aligned π-π stacked molecules and strong intermolecular hydrogen bonds, crystalline poly-FDCA CNTh with uniform syn-configuration was obtained above 11 GPa, with the crystal structure determined by Rietveld refinement of the X-ray diffraction (XRD). The in situ XRD and theoretical simulation results show that the FDCA experienced continuous [4 + 2] Diels-Alder reactions along the stacking direction at the threshold C···C distance of â¼2.8 Å. Benefiting from the abundant carbonyl groups, the poly-FDCA shows a high specific capacity of 375 mAh g-1 as an anode material of a lithium battery with excellent Coulombic efficiency and rate performance. This is the first time a three-dimensional crystalline CNTh is obtained, and we demonstrated it is the hydrogen bonds that lead to the formation of the crystalline material with a unique configuration. It also provides a new method to move biomass compounds toward advanced functional carbon materials.
Assuntos
DiamanteRESUMO
BACKGROUND: Our previous study revealed that patients with oral squamous cell carcinoma and concomitant type 2 diabetes mellitus presented a lower 5-year survival rate. Hyperglycemia has been increasingly recognized as a risk factor for more advanced disease and poorer prognosis in patients with oral squamous cell carcinoma. However, its role remains unclear. METHODS: The expressions of BRIP1, Ki67, E-cadherin, and cleaved caspase-3 were detected by immunohistochemistry in oral squamous cell carcinoma tissues with or without type 2 diabetes mellitus. Cell counting kit-8 assay and wound healing assay were used to determine the proliferative and migratory ability of oral squamous cell carcinoma cells cultured with or without high glucose in vitro. Flow cytometry was applied to distinguish the role of high glucose on the cell cycle and apoptosis rates. RESULTS: The expression level of Ki67 was elevated while BRIP1, E-cadherin, and cleaved caspase-3 were downregulated in patients with oral squamous cell carcinoma coexisting with diabetes. The cell proliferation and migration in oral squamous cell carcinoma cell lines were significantly enhanced by high glucose. Flow cytometric analysis suggested that high glucose predisposed cancer cells to stay at S/G2 phase and to exhibit lower apoptosis rates. CONCLUSION: Our results implicated that type 2 diabetes mellitus may play a crucial role in the development and progression of oral squamous cell carcinoma through hyperglycemia, affecting cancer cell proliferation, migration, and apoptosis. This finding might provide a new direction for the prevention and treatment of oral squamous cell carcinoma.
Assuntos
Carcinoma de Células Escamosas , Diabetes Mellitus Tipo 2 , Neoplasias de Cabeça e Pescoço , Hiperglicemia , Neoplasias Bucais , Apoptose , Caderinas , Carcinoma de Células Escamosas/patologia , Caspase 3/metabolismo , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Diabetes Mellitus Tipo 2/complicações , Glucose , Humanos , Antígeno Ki-67 , Neoplasias Bucais/patologia , Carcinoma de Células Escamosas de Cabeça e PescoçoRESUMO
The metallic ground state in two-dimensional (2D) superconductors has attracted much attention but is still under intense scrutiny. Especially, the measurements in the ultralow temperature region are challenging for 2D superconductors due to the sensitivity to external perturbations. In this work, the resistance saturation induced by external noise, named as the "extrinsic anomalous metallic state", is observed in 2D transition metal dichalcogenide (TMD) superconductor 4Ha-TaSe2 nanodevices. However, with further decreasing temperature, credible evidence of the intrinsic anomalous metallic state is obtained by adequately filtering external radiation. Our work indicates that, at ultralow temperatures, the anomalous metallic state can be experimentally revealed as the quantum ground state in 2D crystalline TMD superconductors. Besides, Ising superconductivity revealed by ultrahigh in-plane critical field (Bc2â¥) going beyond the Pauli paramagnetic limit (Bp) is detected in 4Ha-TaSe2, from the one-unit-cell device to the bulk situation, which might be due to the weak coupling between the TaSe2 submonolayers.
RESUMO
Studies have revealed the neuropathological mechanism of the cognitive impairment associated with neurodegenerative diseases.However,the therapies for these cognitive disorders are limited,and the prevalence of cognitive impairment is expected to increase significantly in the future,which proves the necessity of new therapeutic agents.In recent years,the pharmacological activity of ß2-adrenergic receptor(ß2-AR)has been extensively studied,which has demonstrated that ß2-AR agonist has therapeutic effects on the cognitive impairment associated with several common neurodegenerative diseases,including Alzheimer's disease,vascular dementia,Parkinson's disease with dementia,and Lewy body dementia.We reviewed the neuropathological features of cognitive impairment in several common neurodegenerative diseases and expounded the pharmacological effects of ß2-AR on related diseases.
Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Doença por Corpos de Lewy , Doenças Neurodegenerativas , Humanos , Doenças Neurodegenerativas/complicações , Doenças Neurodegenerativas/tratamento farmacológico , Doença por Corpos de Lewy/complicações , Doença por Corpos de Lewy/tratamento farmacológico , Doença por Corpos de Lewy/patologia , Disfunção Cognitiva/tratamento farmacológico , Disfunção Cognitiva/complicações , Agonistas AdrenérgicosRESUMO
Residential locations, the jobs-housing relationship, and commuting patterns are key elements to understand urban spatial structure and how city dwellers live. Their successive interaction is important for various fields including urban planning, transport, intraurban migration studies, and social science. However, understanding of the long-term trajectories of workplace and home location, and the resulting commuting patterns, is still limited due to lack of year-to-year data tracking individual behavior. With a 7-y transit smartcard dataset, this paper traces individual trajectories of residences and workplaces. Based on in-metro travel times before and after job and/or home moves, we find that 45 min is an inflection point where the behavioral preference changes. Commuters whose travel time exceeds the point prefer to shorten commutes via moves, while others with shorter commutes tend to increase travel time for better jobs and/or residences. Moreover, we capture four mobility groups: home mover, job hopper, job-and-residence switcher, and stayer. This paper studies how these groups trade off travel time and housing expenditure with their job and housing patterns. Stayers with high job and housing stability tend to be home (apartment unit) owners subject to middle- to high-income groups. Home movers work at places similar to stayers, while they may upgrade from tenancy to ownership. Switchers increase commute time as well as housing expenditure via job and home moves, as they pay for better residences and work farther from home. Job hoppers mainly reside in the suburbs, suffer from long commutes, change jobs frequently, and are likely to be low-income migrants.
RESUMO
Urban rail transit (URT) systems are often regarded as the backbone of their respective city. The evolutionary features of URT systems have attracted much attention in recent years, but their evolution and their distinct function in contrast to other transit modes have seldom been investigated, especially quantitatively from the perspective of work-residence separation. Accordingly, we propose a framework for exploring the evolution of URT topological networks and demand-weighted networks, comparing the different impacts of all transit modes on work-residence separation. In this study, a URT passenger flow assignment model was formulated on the basis of travel cost function and an improved logit model was proposed that takes into account the heterogeneity of passengers. This model was used to generate a section load, which is regarded as a weight and able to reflect the residents' demand for travel by URT. Then, the fractal dimensions for a non-weighted network and demand-weighted network are proposed and their indications for transportation explained. Finally, the Beijing Subway System (BSS) is used as a case study by employing fifty years of network data and ten years of smart card data. Using fractal approaches, the different characteristics illustrated by the two networks were investigated and the reasons behind the observed patterns explained. In addition, the spatial features of the rail network, in terms of fractal indictors, were compared with population distribution and urban mobility for all modes, extracted from phone data as a proxy. Thus, the relationship between the residents' travel demand and traffic supply can be revealed to some extent. The main finding of this work is that demand must be taken into account when analyzing the fractal features of a transport network, lest the demand side be separated from the supply and important issues missed such as inconsistencies between demand and supply. Additionally, the role of rail transit in work-home imbalance can be investigated in the context of urban mobility for an entire city.
RESUMO
A series of novel bis-BN-naphthalene-fused oxepin derivatives were synthesized via a Pd-catalyzed tandem reaction from brominated 2,1-borazaronaphthalenes and cis-bis(boryl)alkenes. X-ray crystallographic analysis revealed that bis-BN-naphthalene-fused oxepins feature a planar framework. The electronic and photophysical properties of the novel BN-naphthalene-fused oxepins were investigated by UV-vis and fluorescence spectroscopies and density functional theory (DFT) calculations, which disclosed the distinct electronic and photophysical properties of the analogous hydrocarbon system. Interestingly, dual-fluorescent emissions were observed upon dissolving N-substituted derivatives 10-14 in dimethyl sulfoxide. Tunable emission colors especially for white-light emissions can be achieved by controlling the ratio of solvents, concentration, or temperature using only a single-molecule compound.
RESUMO
Early diagnosis of malignant lymphoma is often difficult since the clinical manifestation of the lymphoma occurred in the maxillofacial region is very similar to that of the squamous cell carcinoma. When the pathological diagnosis is not clear, the surgeon is easy to misdiagnose and lead to mistreatment. A patient visited the Affiliated Haikou Hospital of Xiangya School of Medicine, Central South Universily for gingival mass with an ipsilateral submaxillary enlargement. The clinical manifestation and preoperative MRI are very prone to squamous cell carcinoma with metastasis, so we did not take a preoperative pathological examination. The gingival mass was surgical removed firstly, but frozen pathological result showed that it was malignant small round cell tumor. Since the patient was diagnosed as high degree malignant of small round cell tumor and the submandibular region have been significantly metastasized, so we carried out the combined radical dissection of gingival, mandible and neck surgery. The postoperative pathological report was malignant lymphoma, suggesting that the patient was a case of misdiagnosis and mistreatment. This article draws lessons from misdiagnosis and provided experience for seeking improvement measures.
Assuntos
Carcinoma de Células Escamosas/patologia , Erros de Diagnóstico , Neoplasias Gengivais/patologia , Linfoma/patologia , Neoplasias Mandibulares/patologia , Esvaziamento Cervical , Neoplasias Gengivais/cirurgia , Humanos , Linfoma/cirurgia , Neoplasias Mandibulares/secundário , Neoplasias Mandibulares/cirurgiaRESUMO
Internal combustion engines (ICEs) are widely used in many important fields. The valve train clearance of an ICE usually exceeds the normal value due to wear or faulty adjustment. This work aims at diagnosing the valve clearance fault based on the vibration signals measured on the engine cylinder heads. The non-stationarity of the ICE operating condition makes it difficult to obtain the nominal baseline, which is always an awkward problem for fault diagnosis. This paper overcomes the problem by inspecting the timing of valve closing impacts, of which the referenced baseline can be obtained by referencing design parameters rather than extraction during healthy conditions. To accurately detect the timing of valve closing impact from vibration signals, we carry out a new method to detect and extract the commencement of the impacts. The results of experiments conducted on a twelve-cylinder ICE test rig show that the approach is capable of extracting the commencement of valve closing impact accurately and using only one feature can give a superior monitoring of valve clearance. With the help of this technique, the valve clearance fault becomes detectable even without the comparison to the baseline, and the changing trend of the clearance could be trackable.
RESUMO
The stereoselectivity in the 6-exo cyclization of α-carbamoyl radicals was investigated experimentally and theoretically. The BEt3/O2-initiated iodine-atom-transfer radical cyclization reactions of substituted N-(but-3-en-1-yl)-N-(tert-butyl)-2-iodoalkanamides were carried out, which led to the predominant formations of 3,4-cis, 4,5-trans, or 4,6-trans substituted δ-lactams. Density functional calculations at the B3LYP/6-31G* level revealed that the 6-exo radical cyclization proceeds via boat-conformational transition states. Furthermore, a mechanistic insight into the stereoselectivity was provided and the calculation results were in excellent agreement with the experimental observations.
RESUMO
The field of evolutionary multitasking optimization (EMTO) has been a highly anticipated research topic in recent years. EMTO aims to utilize evolutionary algorithms to concurrently solve complex problems involving multiple tasks. Despite considerable advancements in this field, numerous evolutionary multitasking algorithms continue to use a single evolutionary search operator (ESO) throughout the evolution process. This strategy struggles to completely adapt to different tasks, consequently hindering the algorithm's performance. To overcome this challenge, this paper proposes multitasking evolutionary algorithms via an adaptive bi-operator strategy (BOMTEA). BOMTEA adopts a bi-operator strategy and adaptively controls the selection probability of each ESO according to its performance, which can determine the most suitable ESO for various tasks. In an experiment, BOMTEA showed outstanding results on two well-known multitasking benchmark tests, CEC17 and CEC22, and significantly outperformed other comparative algorithms.
RESUMO
In this paper, we present a two-phase multimodal optimization model designed to efficiently and accurately identify multiple optima. The first phase employs a population-based search algorithm to locate potential optima, while the second phase introduces a novel peak identification (PI) procedure to filter out non-optimal solutions, ensuring that each identified solution represents a distinct optimum. This approach not only enhances the effectiveness of multimodal optimization but also addresses the issue of redundant solutions prevalent in existing algorithms. We propose two PI algorithms: HVPI, which uses a hill-valley approach to distinguish between optima, without requiring prior knowledge of niche radii; and HVPIC, which integrates HVPI with bisecting K-means clustering to reduce the number of fitness evaluations (FEs). The performance of these algorithms was evaluated using the F-measure, a comprehensive metric that accounts for both the accuracy and redundancy in the solution set. Extensive experiments on a suite of benchmark functions and engineering problems demonstrated that our proposed algorithms achieved a high precision and recall, significantly outperforming traditional methods.
RESUMO
In this study, polyimide (PI) and polysulfonamide (PSA) were used as base materials, and polyethylene glycol (PEG) was added to successfully prepare PI/PSA/PEG nanofiber membranes through electrospinning technology. Subsequently, water etching was performed on the membranes, utilizing the water solubility of PEG to form the rough wrinkled structure, further enhancing the surface hydrophobicity. The experimental results showed that under the conditions of a spinning voltage of 10 kV, PI/PSA mass fraction of 15 wt.%, and PEG-to-PI/PSA mass ratio of 1/3, the obtained fiber membranes exhibit a uniform morphology (an average diameter of 0.73 µm) and excellent hydrophobicity (the initial water contact angle (WCA) reaching 130.4°). After PEG water etching, the surface of the PI/PSA/PEG hydrophobic membranes formed the rough wrinkled structure, which not only improved their mechanical properties but also further enhanced their hydrophobicity (the initial WCA increasing to 137.9°). Hence, fiber membranes are expected to have broad application prospects in fields such as waterproofing and moisture permeability.
RESUMO
The set packing problem is a core NP-complete combinatorial optimization problem which aims to find the maximum collection of disjoint sets from a given collection of sets, S, over a ground set, U. Evolutionary algorithms (EAs) have been widely used as general-purpose global optimization methods and have shown promising performance for the set packing problem. While most previous studies are mainly based on experimentation, there is little theoretical investigation available in this area. In this study, we analyze the approximation performance of simplified versions of EAs, specifically the (1+1) EA, for the set packing problem from a theoretical perspective. Our analysis demonstrates that the (1+1) EA can provide an approximation guarantee in solving the k-set packing problem. Additionally, we construct a problem instance and prove that the (1+1) EA beats the local search algorithm on this specific instance. This proof reveals that evolutionary algorithms can have theoretical guarantees for solving NP-hard optimization problems.
RESUMO
BACKGROUND: Lung cancer (LC) is the leading cause of malignancy-related deaths worldwide. The most common sites of metastasis include the nervous system, bone, liver, respiratory system, and adrenal glands. LC metastasis in the parotid gland is very rare, and its diagnosis presents a challenge. Here, we report a case of parotid metastasis in primary LC. CASE SUMMARY: The patient was a 74-year-old male who was discovered to have bilateral facial asymmetry inadvertently two years ago. The right earlobe was slightly swollen and without pain or numbness. Computed tomography (CT) examination showed bilateral lung space-occupying lesions. Pulmonary biopsy was performed and revealed adenocarcinoma (right-upper-lung nodule tissue). Positron emission tomography-CT examination showed: (1) Two hypermetabolic nodules in the right upper lobe of the lung, enlarged hypermetabolic lymph nodes in the right hilar and mediastinum, and malignant space-occupying lesion in the right upper lobe of the lung and possible metastasis to the right hilar and mediastinal lymph nodes; and (2) multiple hypermetabolic nodules in bilateral parotid glands. Parotid puncture biopsy was performed considering lung adenocarcinoma metastasis. Gene detection of lung biopsy specimens revealed an EGFR gene 21 exon L858R mutation. CONCLUSION: This case report highlights the challenging diagnosis of parotid metastasis in LC given its rare nature. Such lesions should be differentiated from primary tumors of the parotid gland. Simple radiological imaging is unreliable, and puncture biopsy is needed for final diagnosis of this condition.
RESUMO
The gut microbiota of fish is crucial for their growth, development, nutrient uptake, physiological balance, and disease resistance. Yet our knowledge of these microbial communities in wild fish populations in their natural ecosystems is insufficient. This study systematically examined the gut microbial communities of seven wild fish species in Chaohu Lake, a fishing-restricted area with minimal water turnover, across four seasons. We found significant variations in gut microbial community structures among species. Additionally, we observed significant seasonal and regional variations in the gut microbial communities. The Chaohu Lake fish gut microbial communities were predominantly composed of the phyla Firmicutes, Proteobacteria(Gamma), Proteobacteria(Alpha), Actinobacteriota, and Cyanobacteria. At the genus level, Aeromonas, Cetobacterium, Clostridium sensu stricto 1, Romboutsia, and Pseudomonas emerged as the most prevalent. A co-occurrence network analysis revealed that C. auratus, C. carpio, and C. brachygnathus possessed more complex and robust gut microbial networks than H. molitrix, C. alburnus, C. ectenes taihuensis, and A. nobilis. Certain microbial groups, such as Clostridium sensu stricto 1, Romboutsia, and Pseudomonas, were both dominant and keystone in the fish gut microbial network. Our study offers a new approach for studying the wild fish gut microbiota in natural, controlled environments. It offers an in-depth understanding of gut microbial communities in wild fish living in stable, limited water exchange natural environments.