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1.
Opt Lett ; 49(11): 3126-3129, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38824344

RESUMO

Graphene is a kind of two-dimensional material with a single-layer carbon structure and has been investigated in many high-performance photodetectors. The lateral photovoltaic effect (LPE) is widely used in the position-sensitive detectors (PSDs) owing to its linear response of photovoltage to the light position. In this Letter, a type of graphene-enhanced LPE is observed in the Ag nanoparticle-covered graphene/n-type Si. The LPE sensitivity can reach 97.3 mV/mm, much higher than the sensitivity of 1.3 mV/mm in the control sample of Ag/Si and 5.2 mV/mm of graphene/Si. Based on the photocarriers' diffusion mechanism, tailoring a photocarrier transfer at the interface of a heterojunction plays a key role for the enhancement. These findings exhibit great application potential of graphene in the field of PSDs and offer an effective method for the optimization of LPE devices.

2.
Environ Toxicol ; 39(3): 1388-1401, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37986241

RESUMO

Silver is usually loaded on nano-titanium dioxide (TiO2 ) through photodeposition method to enhance visible-light catalytic functions for environment purification. However, little is known about how the toxicity changes after silver doping and how the physicochemical properties of loaded components affect nanocomposite toxicity. In this study, Ag-TiO2 with different sizes and contents of silver particles were obtained by controlling photodeposition time (PDT) and silver addition amount. Pro-inflammatory and pro-fibrogenic responses of these photocatalysts were evaluated in male C57BL/6J murine lung. As a result, silver was well assembled on TiO2 , promoting visible-light catalytic activity. Notably, the size of silver particles increased with PDT. Meanwhile, toxicity results showed that pure TiO2 (P25) mainly caused neutrophil infiltration, while 2 wt/wt% silver-loaded TiO2 recruited more types of inflammatory cells in the lung. Both of them caused the increase of proinflammatory cytokines while decreasing the anti-inflammatory cytokine in bronchoalveolar lavage fluid. However, 2 wt/wt% silver doping also accelerated the lung pro-fibrogenic response of photocatalysts in the subacute phase from evidence of collagen deposition and hydroxyproline concentrations. Mechanistically, the overactivation of TGFBR2 receptors in TGF-ß/smads pathways by silver-loaded TiO2 rather than pure TiO2 may be the reason why silver-loaded TiO2 can promote pro-fibrogenic effect response. Intriguingly, the increased toxicity caused by silver doping can be rescued by increasing the size of the loaded silver or decreasing the silver amount. These results may be important for the new understanding of the toxicity of TiO2 -based photocatalysts.


Assuntos
Nanopartículas Metálicas , Prata , Camundongos , Masculino , Animais , Prata/química , Nanopartículas Metálicas/química , Pulmão , Líquido da Lavagem Broncoalveolar , Titânio/química , Citocinas
3.
Environ Geochem Health ; 46(4): 124, 2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38483643

RESUMO

This study analyzed the distribution and content of eight heavy metals (Cu, Pb, Zn, Ni, Cr, As, Cd, and Hg) in 221 surface soil samples from the upper reaches of the Xiaowen River. Environmental geochemical baselines were established for the eight heavy metals, and the pollution status was assessed on the basis of these baselines and the soil background value of Weifang City. The calculation results of Nemerow pollution index and the potential ecological hazard index (PEHI)-Ri showed that the overall pollution degree and ecological hazard in the study area were at a slight level. 49% (calculated by baseline value) and 24% (calculated by background value of Weifang City) samples were at moderate or above pollution level. 9% (calculated by baseline value) and 42% (calculated by background value) samples were at the level of moderate potential ecological hazards or above. According to the calculation results of Igeo and PEHI-Ei, the main pollutant in the study area was Hg, followed by Cd. 3% (calculated by baseline value) and 12% (calculated by background value) of Hg samples were at moderate or above contamination levels. 5% (calculated by baseline value) and 38% (calculated by background value) of Hg samples were at the level of strong potential ecological hazard or above. The western, central, and eastern parts of the study area were mainly the primary areas of pollution and ecological hazards. The non-carcinogenic risk was at an acceptable level, the carcinogenic risk was at a tolerable level, and the main risk pathway was oral intake, with Cr being the main contributor. Source apportionment indicated that soil heavy metals primarily originate from soil parent material, transportation, agricultural fertilization, and industrial emissions (waste gas, waste water and solid waste).


Assuntos
Mercúrio , Metais Pesados , Poluentes do Solo , Solo/química , Monitoramento Ambiental/métodos , Rios/química , Cádmio , Poluentes do Solo/análise , Metais Pesados/análise , Medição de Risco , China
4.
Environ Monit Assess ; 196(2): 122, 2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38194101

RESUMO

The natural environment, as well as human production and survival, is intrinsically dependent on soil. This study comprehensively assessed the pollution status, health risks, and sources of trace metals in the middle reaches of the River Gui Basin (MRGB) utilizing the geoaccumulation index, potential ecological risk index (PERI), and human health risk evaluation method. The findings of this study provide the following key insights: (1) only Cu and Pb levels in the MRGB soils did not exceed the background values established for soils in Weifang City (WFC). (2) The geoaccumulation status in most areas of the MRGB ranged from non-polluted to mildly polluted, with the overall ecological risk classification ranging from mild to moderate. (3) The cumulative non-carcinogenic risk for humans in the MRGB remained within acceptable limits, whereas the carcinogenic risk indices fell within tolerable levels. Oral ingestion emerged as the primary exposure pathway for both non-carcinogenic and carcinogenic health risks. (4) Cu, Zn, Ni, and Cr concentrations in MRGB soils primarily stemmed from natural sources associated with parent rocks, with Zn exhibiting additional influence from anthropogenic factors. In contrast, Pb, Cd, Hg, and As concentrations were predominantly driven by anthropogenic sources. Although the soils in the MRGB typically exhibited mild-to-moderate contamination levels, the contamination levels of Hg and Cd were notably more severe. As and Cr were significant health hazards. Most soil contamination sources are attributed to anthropogenic factors, warranting heightened attention from the relevant authorities.


Assuntos
Mercúrio , Oligoelementos , Humanos , Cádmio , Chumbo , Rios , Monitoramento Ambiental , Carcinógenos , Solo , Medição de Risco
5.
Opt Lett ; 48(13): 3531-3534, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37390173

RESUMO

Position-sensitive detectors (PSDs) based on the lateral photovoltaic effect (LPE) are widely used for precision displacement and angle measurement. However, high temperatures can lead to the thermal decomposition or oxidation of nanomaterials frequently utilized in PSDs, and can ultimately affect the performance. In this study, we present a PSD based on Ag/nanocellulose/Si that maintains a maximum sensitivity of 416.52 mV/mm, even at elevated temperatures. By encapsulating nanosilver in a nanocellulose matrix, the device demonstrates excellent stability and performance over a wide temperature range from 300 to 450 K. Its performance can be comparable to that of room temperature PSDs. An approach that uses nanometals to regulate optical absorption and the local electric field overcomes carrier recombination due to nanocellulose, enabling a breakthrough in sensitivity for organic PSDs. The results indicate that the LPE in this structure is dominated by local surface plasmon resonance, presenting opportunities for expanding optoelectronics in high-temperature industrial environments and monitoring applications. The proposed PSD offers a simple, fast, and cost-effective solution for real-time laser beam monitoring, and its high-temperature stability makes it ideal for a wide range of industrial applications.


Assuntos
Eletricidade , Nanoestruturas , Ressonância de Plasmônio de Superfície
6.
Small ; 18(7): e2105188, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34862713

RESUMO

As one of the typical transition-metal dichalcogenides with distinct optical and electrical properties, WS2 exhibits tremendous potential for optoelectronic devices. However, its inherent band gap range limits the application in the infrared region. To overcome this draw-back and improve the sensitivity, P(VDF-CTFE) is used as a ferroelectric gate to control the states of WS2 /Si junctions and achieve an enhanced infrared photodetection. The polarization electric field not only broadens the range of absorption wavelength (405-1550 nm) but also greatly promotes the sensitivity of lateral photovoltaic effect (LPE) (from 198.6 to 503.2 mV mm-1 ). This phenomenon is attributed to the reduction of WS2 band gap and the change of potential barrier at the interface of the junction. Meanwhile, the response speed is improved significantly due to the increase of carrier initial kinetic energy. This new scheme for ferroelectric tuned LPE opens up a way to realize high-sensitivity, ultrafast, and stable infrared photodetection.

7.
Opt Lett ; 46(13): 3041-3044, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34197374

RESUMO

Complex oxide perovskites exhibit a range of novel, to the best of our knowledge, physical phenomena and have gained popularity as a material system in the past decades. Strontium titanate (SrTiO3) is an iconic material among oxide perovskite due to its unusual electronic transport behavior and has been investigated in many electronic devices. In this Letter, a type of SrTiO3 nano-film-induced enhancement of lateral photovoltaic effect (LPE) is observed in the heterojunction of Ti/SrTiO3/p-type Si. Optimizing the thickness of SrTiO3, the LPE sensitivity can reach 123.2 mV/mm, which is much higher than the sensitivity in the control samples of Ti/Si (55.3 mV/mm) and SrTiO3/Si (∼0mV/mm). These findings offer an effective way to improve the sensitivity and will be helpful in the development of oxide-based photodetection devices.

8.
Nanotechnology ; 32(50)2021 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-34525467

RESUMO

Due to magnetic field tunability and the abundance of iron in the Earth's crust, iron oxide-based resistive random access memory (RRAM) is considered to be low cost and potential for multi-level storage. However, the relatively high operation voltage (>1 V) and small storage window (<100) limit its application. In this work, the devices with simple Ag/Fe2O3/Pt structure exhibit typical bipolar resistive switching with ultralow set voltage (Vset) of 0.16 V, ultralow reset voltage (Vreset) of -0.04 V, high OFF/ON resistance ratio of 103, excellent cycling endurance more than 104and good retention time longer than 104s. Each major parameter has about an order of magnitude improvement compared to the previous data. The devices demonstrate outstanding stable low power consumption quality. Based on the analysis of the experimental results, a percolation model of silver ion migration was established and confirmed that low operation voltage is attributed to the amorphous oxide layer with large porosity. During electrical testing, the compliance current (Ic) and maximum reset voltage (Vmax) can also affect the device performance. This discovery suggests Fe2O3memristor has significant potential for application and provides a new idea for the realization of high-performance low-power RRAM.

9.
Sensors (Basel) ; 21(20)2021 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-34696029

RESUMO

As a typical application of sensor networks, there exist many information security problems in smart parks, such as confusion of personnel access, lack of security management, disorderly data flow, insufficient collection of audit evidence, and so on. Aiming at the scenario of personnel and equipment moving in different areas of smart parks, the paper proposes a joint authorization and dynamic access control mechanism, which can provide unified identity management services, access control services, and policy management services, and effectively solve the problem of multi-authorization in user identity and authority management. The license negotiation interaction protocol is designed to prevent common network attack threats in the process of identity authentication and authority management. In order to realize the tamper-proof storage of personnel and equipment movement trajectory, the paper also designs a movement trajectory traceability protocol based on a Merkle tree, which solves the problems of internal personnel malicious attack, trusted third-party dependency bottleneck, high overheads of tracking algorithms, and so on. The experimental results show that compared with the current security control mechanisms for sensor networks, the joint authorization, and dynamic access control mechanism can support multi-party authorization and traceability, while the overhead it generates in initialization, encryption, decryption, and key generation steps are basically the same as other mechanisms do.


Assuntos
Algoritmos , Segurança Computacional
10.
Sensors (Basel) ; 21(17)2021 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-34502799

RESUMO

Social distancing protocols have been highly recommended by the World Health Organization (WHO) to curb the spread of COVID-19. However, one major challenge to enforcing social distancing in public areas is how to perceive people in three dimensions. This paper proposes an innovative pedestrian 3D localization method using monocular images combined with terrestrial point clouds. In the proposed approach, camera calibration is achieved based on the correspondences between 2D image points and 3D world points. The vertical coordinates of the ground plane where pedestrians stand are extracted from the point clouds. Then, using the assumption that the pedestrian is always perpendicular to the ground, the 3D coordinates of the pedestrian's feet and head are calculated iteratively using collinear equations. This allows the three-dimensional localization and height determination of pedestrians using monocular cameras, which are widely distributed in many major cities. The performance of the proposed method was evaluated using two different datasets. Experimental results show that the pedestrian localization error of the proposed approach was less than one meter within tens of meters and performed better than other localization techniques. The proposed approach uses simple and efficient calculations, obtains accurate location, and can be used to implement social distancing rules. Moreover, since the proposed approach also generates accurate height values, exclusionary schemes to social distancing protocols, particularly the parent-child exemption, can be introduced in the framework.


Assuntos
COVID-19 , Pedestres , Calibragem , , Humanos , SARS-CoV-2
11.
Nanotechnology ; 31(40): 405301, 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-32512546

RESUMO

An improvement in the uniformity of resistive switching behaviors by embedding Cu nanodots is observed in Ta2O5 memory cells. In the conventional device structure, the growth of conductive filaments tends to be random and uncontrollable, which is the major obstacle for memory cell fabrication. By using a bottom electrode covered in metal nanodots, the field distribution in the electrolyte layer is modified and the conductive filaments prefer to grow along the direction of the Cu nanodots. Such controlled growth of conductive filaments leads to a reduced variation of switching parameters, as well as the disappearance of an unpredictable multistep resistive switching phenomenon, which is helpful for improving the device stability. Meanwhile, scaling relations are used to reveal the relationship between switching parameters and the microstructure of conductive filaments. By overlapping the scaling relations and electric field simulation, a model is proposed to explain the improvement in resistive switching performance caused by the presence of embedded Cu nanodots.

12.
Front Endocrinol (Lausanne) ; 15: 1374888, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38808118

RESUMO

Introduction: Fine needle aspiration (FNA) biopsy is a widely accepted method for diagnosing thyroid nodules. However, the influence of maximum diameter (MD) of ACR TIRADS 5 (TR5) thyroid nodules on the FNA outcomes remains debated. This study examined the influence of MD on the FNA outcomes and investigated the optimal MD threshold for FNA in TR5 nodules. Methods: We conducted a retrospective analysis of 280 TR5 thyroid nodules from 226 patients who underwent FNA from January to June 2022 in our department. Probably malignant (PM) group was defined as Bethesda V in cytopathology with confirmed BRAF V600E mutation or Bethesda VI, the other cytopathology outcomes were defined as probably benign (PB) group. We examined factors influencing malignant cytopathology outcomes and determined the optimal MD threshold for FNA in TR5 nodules using logistic regression and restricted cubic spline (RCS) analysis. Results: Among these nodules, 58.2% (163/280) had PM outcomes. The PM group had a significantly larger MD than the PB group [6.5mm (range 5.0-8.4) vs. 5.3mm (range 4.0-7.0), p < 0.001]. In multivariate logistic regression fully adjusted for confounders, MD was significantly associated with PM outcomes [odds ratio 1.16, 95%CI 1.05-1.31; p = 0.042]. The highest quartile of MD had a greater likelihood of PM outcomes compared to the lowest quartile [odds ratio 4.71, 95% CI 1.97-11.69, p = 0.001]. The RCS analysis identified 6.2 mm as the optimal MD threshold for FNA in TR5 nodules. Conclusion: MD significantly affects the probability of malignant outcomes in FNA of TR5 thyroid nodules. A MD threshold of ≥6.2mm is suggested for FNA in these nodules.


Assuntos
Nódulo da Glândula Tireoide , Humanos , Nódulo da Glândula Tireoide/patologia , Biópsia por Agulha Fina , Feminino , Masculino , Estudos Retrospectivos , Pessoa de Meia-Idade , Adulto , Idoso , Idoso de 80 Anos ou mais
13.
Life Sci ; 307: 120840, 2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-35905812

RESUMO

In recent years, the wide application of nanoparticles (NPs) inevitably leads to environmental pollution and human exposure, and its safety has attracted more and more attention. Since macrophages are the cells most directly exposed to multi-pathway invading NPs in the body, it is necessary to assess of toxic effects of NPs in macrophages, clarify the potential mechanisms of NPs toxicity to improve our understanding about the interaction of NPs with macrophages in vivo, and avoid body damage. Currently, studies on the toxicity of NPs to macrophages are rare and mainly focused on in vitro, so this paper integrated the toxic effect of macrophages exposed to NPs and the macrophages cellular changes following the interaction with NPs, including NPs internalization, ROS production, cytokines alterations, DNA damage and cell death, and further explored the involved mechanisms. This review aims to provide some insights into the further toxicological studies of NPs.


Assuntos
Nanopartículas Metálicas , Nanopartículas , Morte Celular , Citocinas/metabolismo , Humanos , Macrófagos/metabolismo , Nanopartículas Metálicas/toxicidade , Nanopartículas/metabolismo , Nanopartículas/toxicidade , Espécies Reativas de Oxigênio/metabolismo
14.
Histol Histopathol ; 37(8): 791-802, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35285011

RESUMO

OBJECTIVE: The present study aimed to explore the clinicopathological characteristics, potential heterogeneity and prognostic factors in synchronous bilateral breast cancer (SBBC). METHODS: We performed a retrospective review and paired comparison of the clinicopathological characteristics of 114 patients with SBBC in the Peking Union Medical College Hospital from January 2008 to September 2019. The prognostic significance of triple negativity status and coexistence ductal carcinoma in situ (DCIS) with bilateral invasive ductal carcinomas of no special type (IDC-NST) was analyzed in SBBC. RESULTS: Most bilateral lesions on both sides were of IDC-NST, grade 2, luminal subtype, and stage I. Although most lesions were concordant between the left and right side, discordances were observed in histological type (25 cases, 21.9%), histological grade (31 cases, 27.2%), pTNM (61 cases, 53.5%), molecular subtypes (20 cases, 17.5%), and immunohistochemical staining of ER (18 cases, 15.8%), PR (26 cases, 22.8%), and HER2 (12 cases, 10.5%). Moreover, there was no significant difference in disease-free survival (DFS) and overall survival (OS) between IDC-NST with coexisting DCIS on both sides and IDC-NST with coexisting DCIS on one side or pure IDC-NST. SBBC with triple negativity on both sides exhibited a significantly shorter DFS and OS when compared with triple negativity on one side or non-triple negativity on both sides (p<0.001), and remained an independent prognostic factor by multivariate analysis. CONCLUSIONS: A considerable proportion of discordance in clinicopathological characteristics is observed in SBBC, supporting the necessity of comprehensive pathological examination including immunohistochemical testing on both sides in clinical practice. Moreover, SBBC with triple negativity on both sides is a prognostic for poor survival.


Assuntos
Neoplasias da Mama , Carcinoma Ductal de Mama , Carcinoma Intraductal não Infiltrante , Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/patologia , Carcinoma Intraductal não Infiltrante/patologia , Intervalo Livre de Doença , Feminino , Humanos , Prognóstico , Análise de Sobrevida
15.
PLoS One ; 16(7): e0254711, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34265005

RESUMO

GRF genes have been confirmed to have important regulatory functions in plant growth, development and response to abiotic stress. Although the genome of Jatropha curcas is sequenced, knowledge about the identification of the species' GRF genes and their expression patterns is still lacking. In this study, we characterized the 10 JcGRF genes. A detailed investigation into the physic nut GRF gene family is performed, including analysis of the exon-intron structure, conserved domains, conserved motifs, phylogeny, chromosomal locations, potential small RNA targets and expression profiles under both normal growth and abiotic stress conditions. Phylogenetic analysis indicated that the 10 JcGRF genes were classified into five groups corresponding to group I, II, III, IV and V. The analysis of conserved domains showed that the motifs of JcGRF genes were highly conserved in Jatropha curcas. Expression analysis based on RNA-seq and qRT-PCR showed that almost all JcGRF genes had the highest expression in seeds, but very low expression was detected in the non-seed tissues tested, and four JcGRF genes responded to at least one abiotic stress at at least one treatment point. Our research will provide an important scientific basis for further research on the potential functions of JcGRF genes in Jatropha curcas growth and development, and response to abiotic stress, and will eventually provide candidate genes for the breeding of Jatropha curcas.


Assuntos
Jatropha , Filogenia , Secas , Genoma de Planta , Sementes
16.
Medicine (Baltimore) ; 98(15): e15213, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30985720

RESUMO

RATIONALE: Hemolymphangioma is a rare developmental defect of combined vasal and lymphatic vasculature. It is very rare that hemolymphangioma affects the bones and bladder simultaneously, and this condition has never been reported in PubMed. PATIENT CONCERNS: A 12-year-old male has a history of hospitalization for recurrent episodes of chyluria of 8 years duration and progressively worsening gross hematuria with right hip pain for 6 months. DIAGNOSIS: Chylous test of urine fluid was positive. There was no organic disease in the kidneys. Ga-NOTA-Evans Blue (NEB) positron emission tomography/computed tomography (PET/CT) images demonstrated clearly several round and strip-shaped low-density shadows with mildly increased radioactive uptake in both bladder wall and pelvis, including sacral, pubic, and ischial bones. Histopathological analysis of biopsy on pubic and ischial bones confirmed the diagnosis of hemolymphangioma. INTERVENTIONS: The patient received treatment with traditional Chinese medicine. OUTCOMES: At the 6-month follow-up visit, the patient's symptoms of chyluria, hematuria, and pain were all mitigated. LESSONS: Hemolymphangioma is a rare benign disease. Ga-NEB PET/CT is a specific method for the lymphatic system, and it might provide more accurate and comprehensive information about the disorder of the lymphatic system compared with CT and magnetic resonance imaging. When patients suffer from suspected lesions of the lymphatic system, Ga-NEB PET/CT might be recommended.


Assuntos
Neoplasias Ósseas/diagnóstico por imagem , Linfangioma/diagnóstico por imagem , Neoplasias da Bexiga Urinária/diagnóstico por imagem , Animais , Neoplasias Ósseas/patologia , Neoplasias Ósseas/terapia , Criança , Complexos de Coordenação , Diagnóstico Diferencial , Humanos , Linfangioma/patologia , Linfangioma/terapia , Masculino , Medicina Tradicional Chinesa , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Compostos Radiofarmacêuticos , Neoplasias da Bexiga Urinária/patologia , Neoplasias da Bexiga Urinária/terapia
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