Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 60
Filtrar
1.
Int. j. morphol ; 42(2)abr. 2024.
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1558135

RESUMO

SUMMARY: Overexpression of metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in various tumor tissues and cell lines was found to promote tumor cell proliferation, migration, and invasion. However, the role of MALAT1 in gastric cancer (GC) is still unclear. We aimed to investigate the correlation between long-chain non-coding RNAs (lncRNAs), MALAT1, MicroRNAs (miRNA) and vascular endothelial growth factor A (VEGFA) in gastric cancer and to disclose underlying mechanism. The correlation between MALAT1 levels and clinical features was analyzed by bioinformatics data and human samples. The expression of MALAT1 was down regulated in AGS cells to detect the cell proliferation, migration, and invasion characteristics, as well as the effects on signal pathways. Furthermore, we validated the role of MALAT1/miR-330-3p axis in GC by dual luciferase reporter gene assays. Expression of MALAT1 was higher in cancer tissues than in para-cancerous tissues. The high MALAT1 level predicted malignancy and worse prognosis. Down-regulation of MALAT1 expression in AGS cells inhibited cell proliferation, migration, and invasion by targeting VEGFA. By dual luciferase reporter gene assay and miR-330-3p inhibitor treatment, we demonstrate that MALAT1 sponged miR-330-3p in GC, leading to VEGFA upregulation and activation of the mTOR signaling pathway. The MALAT1/miR-330-3p axis regulates VEGFA through the mTOR signaling pathway and promotes the growth and metastasis of gastric cancer.


Se descubrió que la sobreexpresión del transcrito 1 de adenocarcinoma de pulmón asociado a metástasis (MALAT1) en varios tejidos tumorales y líneas celulares promueve la proliferación, migración e invasión de células tumorales. Sin embargo, el papel de MALAT1 en el cáncer gástrico (CG) aún no está claro. Nuestro objetivo fue investigar la correlación entre los ARN no codificantes de cadena larga (lncRNA), MALAT1, los microARN (miARN) y el factor de crecimiento endotelial vascular A (VEGFA) en el cáncer gástrico y revelar el mecanismo subyacente. La correlación entre los niveles de MALAT1 y las características clínicas se analizó mediante datos bioinformáticos y muestras humanas. La expresión de MALAT1 se reguló negativamente en las células AGS para detectar las características de proliferación, migración e invasión celular, así como los efectos sobre las vías de señales. Además, validamos el papel del eje MALAT1/miR- 330-3p en GC mediante ensayos de genes indicadores de luciferasa dual. La expresión de MALAT1 fue mayor en tejidos cancerosos que en tejidos paracancerosos. El alto nivel de MALAT1 predijo malignidad y peor pronóstico. La regulación negativa de la expresión de MALAT1 en células AGS inhibió la proliferación, migración e invasión celular al apuntar a VEGFA. Mediante un ensayo de gen indicador de luciferasa dual y un tratamiento con inhibidor de miR-330-3p, demostramos que MALAT1 esponjaba miR-330-3p en GC, lo que lleva a la regulación positiva de VEGFA y la activación de la vía de señalización mTOR. El eje MALAT1/miR-330-3p regula VEGFA a través de la vía de señalización mTOR y promueve el crecimiento y la metástasis del cáncer gástrico.

2.
Natl Sci Rev ; 11(2): nwad279, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38213527

RESUMO

Graphene is one of the most promising candidates for integrated circuits due to its robustness against short-channel effects, inherent high carrier mobility and desired gapless nature for Ohmic contact, but it is difficult to achieve satisfactory on/off ratios even at the expense of its carrier mobility, limiting its device applications. Here, we present a strategy to realize high back-gate switching ratios in a graphene monolayer with well-maintained high mobility by forming a vertical heterostructure with a black phosphorus multi-layer. By local current annealing, strain is introduced within an established area of the graphene, which forms a reflective interface with the rest of the strain-free area and thus generates a robust off-state via local current depletion. Applying a positive back-gate voltage to the heterostructure can keep the black phosphorus insulating, while a negative back-gate voltage changes the black phosphorus to be conductive because of hole accumulation. Then, a parallel channel is activated within the strain-free graphene area by edge-contacted electrodes, thereby largely inheriting the intrinsic carrier mobility of graphene in the on-state. As a result, the device can provide an on/off voltage ratio of >103 as well as a mobility of ∼8000 cm2 V-1 s-1 at room temperature, meeting the low-power criterion suggested by the International Roadmap for Devices and Systems.

3.
Innovation (Camb) ; 4(6): 100502, 2023 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-37701921

RESUMO

Twin boundaries (TBs) in transition metal dichalcogenides (TMDs) constitute distinctive one-dimensional electronic systems, exhibiting intriguing physical and chemical properties that have garnered significant attention in the fields of quantum physics and electrocatalysis. However, the controlled manipulation of TBs in terms of density and specific atomic configurations remains a formidable challenge. In this study, we present a non-epitaxial growth approach that enables the controlled and large-scale fabrication of homogeneous catalytically active TBs in monolayer TMDs on arbitrary substrates. Notably, the density achieved using this strategy is six times higher than that observed in convention chemical vapor deposition (CVD)-grown samples. Through rigorous experimental analysis and multigrain Wulff construction simulations, we elucidate the role of regulating the metal source diffusion process, which serves as the key factor for inducing the self-oriented growth of TMD grains and the formation of unified TBs. Furthermore, we demonstrate that this novel growth mode can be readily incorporated into the conventional CVD growth method by making a simple modification of the growth temperature profile, thereby offering a universal approach for engineering of grain boundaries in two-dimensional materials.

4.
ACS Nano ; 17(13): 12216-12224, 2023 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-37279100

RESUMO

Chemical growth of two-dimensional (2D) materials with controlled morphology is critical to bring their tantalizing properties to fruition. However, the growth must be on a substrate, which involves either intrinsic or intentionally introduced undulation, at a scale significantly larger than the materials thickness. Recent theory and experiments showed that 2D materials grown on a curved feature on substrates can incur a variety of topological defects and grain boundaries. Using a Monte Carlo method, we herein show that 2D materials growing on periodically undulated substrates with nonzero Gaussian curvature of practical relevance follow three distinct modes: defect-free conformal, defect-free suspension and defective conformal modes. The growth on the non-Euclidean surface can accumulate tensile stress that gradually lifts the materials from substrates and progressively turns the conformal mode into a suspension mode with increasing the undulation amplitude. Further enhancing the undulation can trigger Asaro-Tiller-Grinfield growth instability in the materials, manifested as discretely distributed topological defects due to strong stress concentration. We rationalize these results by model analyses and establish a "phase" diagram for guiding the control of growth morphology via substrate patterning. The undulation-induced suspension of 2D materials can help understand the formation of overlapping grain boundaries, spotted quite often in experiments, and guide how to avoid them.

5.
Materials (Basel) ; 16(11)2023 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-37297287

RESUMO

Currently, the single-point incremental forming process often faces issues such as insufficient formability of the sheet metal and low strength of the formed parts. To address this problem, this study proposes a pre-aged hardening single-point incremental forming (PH-SPIF) process that offers several notable benefits, including shortened procedures, reduced energy consumption, and increased sheet forming limits while maintaining high mechanical properties and geometric accuracy in formed components. To investigate forming limits, an Al-Mg-Si alloy was used to form different wall angles during the PH-SPIF process. Differential scanning calorimetry (DSC) and transmission electron microscopy (TEM) analyses were conducted to characterize microstructure evolution during the PH-SPIF process. The results demonstrate that the PH-SPIF process can achieve a forming limit angle of up to 62°, with excellent geometric accuracy, and hardened component hardness reaching up to 128.5 HV, surpassing the strength of the AA6061-T6 alloy. The DSC and TEM analyses reveal numerous pre-existing thermostable GP zones in the pre-aged hardening alloys, which undergo transformation into dispersed ß" phases during the forming procedure, leading to the entanglement of numerous dislocations. The dual effects of phase transformation and plastic deformation during the PH-SPIF process significantly contribute to the desirable mechanical properties of the formed components.

6.
Small ; 19(7): e2205593, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36461686

RESUMO

The coalescence of randomly distributed grains with different crystallographic orientations can result in pervasive grain boundaries (GBs) in 2D materials during their chemical synthesis. GBs not only are the inherent structural imperfection that causes influential impacts on structures and properties of 2D materials, but also have emerged as a platform for exploring unusual physics and functionalities stemming from dramatic changes in local atomic organization and even chemical makeup. Here, recent advances in studying the formation mechanism, atomic structures, and functional properties of GBs in a range of 2D materials are reviewed. By analyzing the growth mechanism and the competition between far-field strain and local chemical energies of dislocation cores, a complete understanding of the rich GB morphologies as well as their dependence on lattice misorientations and chemical compositions is presented. Mechanical, electronic, and chemical properties tied to GBs in different materials are then discussed, towards raising the concept of using GBs as a robust atomic-scale scaffold for realizing tailored functionalities, such as magnetism, luminescence, and catalysis. Finally, the future opportunities in retrieving GBs for making functional devices and the major challenges in the controlled formation of GB structures for designed applications are commented.

7.
Natl Sci Rev ; 9(9): nwab214, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36199985

RESUMO

Water confined in nanometer-scale crevices and cavities underpins a wide range of fundamental processes, such as capillary flow, ion transport and protein folding. However, how water responds within these confined spaces, with prevalent inhomogeneity built in or caused by impurities, is not well understood. Here, we show theoretically that water confined in one-dimensional nanochannels with localized perturbation exhibits pronounced density oscillations. The oscillations occur vividly like the Friedel oscillations in electron density resulting from defects in metals. A model analysis reveals that the density oscillations result from the perturbation-induced molecular scattering that is augmented by the confinement-enhanced correlation of water dipoles. This renders the oscillations a general behavior independent of the channel geometries and specific forms of the perturbation. Under confinements comparable to biological ion channels, such oscillations can strikingly extend over 10 nm, resulting in non-trivial effects at large distances that, for example, repel all ions from the channels with their long-range force. These results deepen the understanding of biological functions and inspire new applications in a variety of domains, such as ionic sensing and seawater desalination.

8.
Front Microbiol ; 13: 908461, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35783394

RESUMO

In recent decades, infections caused by the opportunistic fungus Candida albicans have increased, especially in patients with immunodeficiency. In this study, we investigated the mechanism of action of sanguinarine (SAN) against C. albicans both in vitro and in vivo. SAN exhibited antifungal activity against C. albicans clinical isolates, with MICs in the range of 112.8-150.5 µM. Furthermore, scanning electron and transmission electron microscopy showed that SAN induced morphological changes as well as structure disruption in C. albicans cells, including masses of cellular debris, ruptured cell walls, and membrane deformation. Flow cytometry revealed that SAN could lead to cell membrane damage, and ergosterol content analysis indicated that SAN could cause ergosterol content reduction exceeding 90%. Further, we validated the efficacy of SAN against candidiasis caused by C. albicans in a murine model, and SAN significantly improved survival and reduced weight loss compared to vehicle. The treatment of 1.5 and 2.5 mg/kg/d SAN obviously reduced the fungal burden in the kidney. In addition, histopathological examination indicated that no fungal cells were observed in lung and kidney tissues after SAN treatment. Hence, this study suggests that SAN is a promising plant-derived compound for the development of an effective anticandidal agent.

9.
Materials (Basel) ; 15(13)2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35806758

RESUMO

Deformation and heat treatment are important means to strengthen aluminum alloys. However, the influence mechanism of pre-strain on aging precipitation kinetics and its effect on mechanical properties are still not clear. In this work, uniaxial isothermal tensile tests with different strains and artificial aging treatments for Al-Zn-Mg-Cu alloys have been carried out. Then, a model describing the precipitates kinetic behavior has been developed to investigate the effect of thermal pre-strain on subsequent aging precipitation kinetics and peak aging microhardness based on the microstructure characterization by TEM, SAXS and XRD tests. In addition, the role of dislocations on the aging precipitation kinetics is also explored. The experimental results show that the peak aging microhardness of the Al-Zn-Mg-Cu alloy reveals a tendency to decrease and increase and then the peak aging time firstly decreases and then keeps almost constant with the increase in the strain. The calculations demonstrate that the precipitate average size almost remains unchanged, while the precipitate volume fraction decreases and then increases with the increase in strain, which is consistent with the change in peak aging microhardness. It also indicates that dislocations can promote precipitate nucleation and growth, while the actual effect depends on the dislocation density, which is closely dependent on the pre-deformation condition, especially for the precipitate nucleation. In particular, when the dislocation density after thermal pre-deformation is not enough, it will slightly inhibit precipitate nucleation but promote precipitate growth, which could shorten the peak aging time, with the peak aging strength being guaranteed.

10.
Materials (Basel) ; 15(13)2022 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-35806849

RESUMO

Due to their high strength, high toughness, and corrosion resistance, high-strength aluminum alloys have attracted great scientific and technological attention in the fields of aerospace, navigation, high-speed railways, and automobiles. However, the fracture toughness and impact toughness of high-strength aluminum alloys decrease when their strength increases. In order to solve the above contradiction, there are currently three main control strategies: adjusting the alloying elements, developing new heat treatment processes, and using different deformation methods. This paper first analyzes the existing problems in the preparation of high-strength aluminum alloys, summarizes the strengthening and toughening mechanisms in high-strength aluminum alloys, and analyzes the feasibility of matching high-strength aluminum alloys in strength and toughness. Then, this paper summarizes the research progress towards adjusting the technology of high-strength aluminum alloys based on theoretical analysis and experimental verification, including the adjustment of process parameters and the resulting mechanical properties, as well as new ideas for research on high-strength aluminum alloys. Finally, the main unsolved problems, challenges, and future research directions for the strengthening and toughening of high-strength aluminum alloys are systematically emphasized. It is expected that this work could provide feasible new ideas for the development of high-strength and high-toughness aluminum alloys with high reliability and long service life.

11.
Lancet HIV ; 9(4): e254-e268, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35364026

RESUMO

BACKGROUND: Poor adherence to oral HIV pre-exposure prophylaxis (PrEP) diminishes its clinical and public health benefits. This study synthesises evidence regarding discontinuation, adherence, and reinitiation of PrEP among geographically diverse PrEP users. METHODS: We did a systematic review and meta-analysis evaluating studies published in MEDLINE, Embase, and Cochrane Central Register of Controlled Trials from inception to Dec 18, 2020. We included longitudinal studies that presented data for PrEP discontinuation, defined as investigator-reported loss to follow-up or participant self-reported PrEP stoppage. Data were extracted from published reports and assessed for risk of bias. We used a random-effects meta-analysis to pool estimates of discontinuation and I2 and τ2 to evaluate heterogeneity. This study is registered with PROSPERO, CRD42020155675. FINDINGS: We identified 4129 records, of which 59 articles were included (n=43 917 participants). 41·0% (95% CI 18·8-63·5) of participants discontinued PrEP within 6 months, with the highest rates in observational studies. The discontinuation rate in sub-Saharan Africa (47·5%, 95% CI: 29·4-66·4%) was higher than in other regions (p<0·001). Discontinuation rates were lower in studies with adherence interventions than in those without (24·7% vs 36·7%, p=0·015). Gay or bisexual men who have sex with men and transgender women offered daily or non-daily dosing options had lower discontinuation rates than those offered daily dosing alone (21·6% vs 31·5%; p<0·001). The pooled suboptimal adherence within 6 months was 37·7% (95% CI 8·4-66·9). Among people who discontinued PrEP, 47·3% (95% CI 31·5-63·2) reinitiated PrEP within 1 year of PrEP initiation. The included studies had poor quality in terms of study design, with a moderate risk of bias. INTERPRETATION: Strategies to encourage reinitiating PrEP for new or persistent risk should be a focus of future PrEP implementation strategies. FUNDING: National Institutes of Health and Nature Science Foundation of China.


Assuntos
Fármacos Anti-HIV , Infecções por HIV , Profilaxia Pré-Exposição , Minorias Sexuais e de Gênero , Fármacos Anti-HIV/uso terapêutico , Feminino , Infecções por HIV/tratamento farmacológico , Infecções por HIV/prevenção & controle , Homossexualidade Masculina , Humanos , Masculino
12.
Materials (Basel) ; 15(6)2022 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-35329629

RESUMO

Friction stir welding (FSW) of aluminum alloys is an advanced manufacturing technology to realize lightweight bodywork. However, most studies only focus on the mechanical properties and corrosion behaviors of the welded joints. The effect of deformation on the corrosion behavior of FSWed joints is unclear. In this work, the plastic deformation behavior was characterized using uniaxial tensile tests. The effect of deformation on the corrosion behavior of a 2024 aluminum alloy nugget was studied by using a Tafel polarization curve, electrochemical impedance spectroscopy, exfoliation corrosion test, scanning electron microscopy and energy dispersive spectrometer, and transmission electron microscopy. The results show that the corrosion resistance of FSWed joints with different deformation degrees can be ranked as: 0% > 7% > 10% > 4%, and an "inflection point" appears at 7%. The corrosion potential and current density at 7% are near the values at 0%, and the 7% sample shows less corrosion rate than all other deformation samples. Only pitting and bubbling occur in the sample in 96 h. With an increase in plastic deformation, the dislocations and dislocation rings increase, there is an increase in the surrounding winding precipitates. The impurity phase is cleaved by dislocations; a reduction in the size of the impurity phase with low chemical activity can be observed, resulting in an increase in corrosion resistance. However, the transgranular and intergranular cracks appear on the 10% deformation sample. They almost always develop along the grain boundaries after initiation, making them more susceptible to corrosion.

13.
Cell Death Discov ; 8(1): 73, 2022 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-35184134

RESUMO

The transformation of tumor cells from an epithelial to a mesenchymal-like phenotype, designated as epithelial-to-mesenchymal transition (EMT), represents a key hallmark of human cancer metastasis, including gastric cancer (GC). However, a large set of non-coding RNAs have been studied for their functions that initiate or inhibit this phenotypic switch in GC cells by regulating oncogenes or tumor suppressors. In this paper, we aimed to identify lncRNA SND1-IT1, miR-124, and COL4A1 gene in the context of GC with a specific focus on their effects on transforming growth factor ß1 (TGF-ß1)-induced EMT. The study included 52 paired samples of lesion tissues and adjacent lesion-free tissues surgically resected from patients diagnosed with GC. HGC-27 cells were stimulated with exogenous TGF-ß1 (2 ng/mL). Expression of lncRNA SND1-IT1, miR-124, and COL4A1 was determined by RT-qPCR. CCK-8 assays, Transwell assays, immunoblotting analysis of EMT-specific markers, and tumor invasion markers were performed to evaluate cell viability, migration, and invasion of cultured HGC-27 cells. Luciferase activity assay was employed to examine miR-124 binding with lncRNA SND1-IT1 and COL4A1, respectively. LncRNA SND1-IT1 was upregulated in GC tissues and cells. TGF-ß1-stimulated EMT and regulated lncRNA SND1-IT1, miR-124, and COL4A1 expressions in HGC-27 cells. LncRNA SND1-IT1 knockdown tempered HGC-27 cell viability, migration and invasion. LncRNA SND1-IT1 participated in TGF-ß1-stimulated EMT in GC by sponging miR-124. MiR-124 attenuated TGF-ß1-stimulated EMT in GC by targeting COL4A1. These results primarily demonstrated TGF-ß1 can regulate cancer cell migration, invasion and stimulate EMT through the SND1-IT1/miR-124/COL4A1 axis in GC.

15.
J Med Internet Res ; 23(8): e23978, 2021 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-34448709

RESUMO

BACKGROUND: Routine HIV testing accompanied with pre-exposure prophylaxis (PrEP) requires innovative support in a real-world setting. OBJECTIVE: This study aimed to determine the usage of HIV self-testing (HIVST) kits and their secondary distribution to partners among men who have sex with men (MSM) in China, who use PrEP, in an observational study between 2018 and 2019. METHODS: In 4 major cities in China, we prospectively followed-up MSM from the China Real-world oral PrEP demonstration study, which provides daily or on-demand PrEP for 12 months, to assess the usage and secondary distribution of HIVST on quarterly follow-ups. Half of the PrEP users were randomized to receive 2 HIVSTs per month in addition to quarterly facility-based HIV testing. We evaluated the feasibility of providing HIVST to PrEP users. RESULTS: We recruited 939 MSM and randomized 471 to receive HIVST, among whom 235 (49.9%) were daily and 236 (50.1%) were on-demand PrEP users. At baseline, the median age was 29 years, 390 (82.0%) men had at least college-level education, and 119 (25.3%) had never undergone facility-based HIV testing before. Three months after PrEP initiation, 341 (74.5%) men had used the HIVST provided to them and found it very easy to use. Among them, 180 of 341 (52.8%) men had distributed the HIVST kits it to other MSM, and 132 (51.6%) among the 256 men who returned HIVST results reported that used it with their sexual partners at the onset of intercourse. Participants on daily PrEP were more likely to use HIVST (adjusted hazard ratio=1.3, 95% CI 1.0-1.6) and distribute HIVST kits (adjusted hazard ratio=1.3, 95% CI 1.1-1.7) than those using on-demand PrEP. CONCLUSIONS: MSM who used PrEP had a high rate of usage and secondary distribution of HIVST kits, especially among those on daily PrEP, which suggested high feasibility and necessity for HIVST after PrEP initiation. Assuming that fourth-generation HIVST kits are available, HIVST may be able to replace facility-based HIV testing to a certain extent. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR1800020374; https://www.chictr.org.cn/showprojen.aspx?proj=32481. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.1136/bmjopen-2019-036231.


Assuntos
Infecções por HIV , Profilaxia Pré-Exposição , Minorias Sexuais e de Gênero , Adulto , China , Estudos de Coortes , Infecções por HIV/diagnóstico , Infecções por HIV/prevenção & controle , Homossexualidade Masculina , Humanos , Internet , Masculino , Estudos Prospectivos , Autoteste
16.
Nat Commun ; 12(1): 4998, 2021 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-34404782

RESUMO

External photo-stimuli on heterojunctions commonly induce an electric potential gradient across the interface therein, such as photovoltaic effect, giving rise to various present-day technical devices. In contrast, in-plane potential gradient along the interface has been rarely observed. Here we show that scanning a light beam can induce a persistent in-plane photoelectric voltage along, instead of across, silicon-water interfaces. It is attributed to the following movement of a charge packet in the vicinity of the silicon surface, whose formation is driven by the light-induced potential change across the capacitive interface and a high permittivity of water with large polarity. Other polar liquids and hydrogel on silicon also allow the generation of the in-plane photovoltage, which is, however, negligible for nonpolar liquids. Based on the finding, a portable silicon-hydrogel array has been constructed for detecting the shadow path of a moving Cubaris. Our study opens a window for silicon-based photoelectronics through introducing semiconductor-water interfaces.

17.
Photodiagnosis Photodyn Ther ; 35: 102431, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34233223

RESUMO

BACKGROUND: Numerous studies have confirmed that 5-aminolevulinic acid-based photodynamic therapy (ALA-PDT) is an effective treatment for human papillomavirus-associated diseases. In this study, we evaluated the variables associated with human papillomavirus (HPV) persistence or clearance after ALA-PDT in patients with genital warts. METHODS: We performed a retrospective chart review of all patients with genital warts or subclinical HPV infection who received ALA-PDT treatment between January 2019 and December 2020 at Nanfang Hospital and Dermatology Hospital of Southern Medical University and analyzed the predictors of HPV persistence or clearance. HPV genotype and viral load assays were analyzed before treatment and after each session of photodynamic therapy. RESULTS: Multiple sexual partners, a history of recurrent HPV infection, and severe pain response during photodynamic therapy were associated with higher odds of viral persistence after three rounds of ALA-PDT. Infection with single strains of HPV, and mucosal and subclinical infection were more likely to be cleared after three rounds of photodynamic therapy. CONCLUSION: Our findings suggest that patients with multiple sexual partners, a history of recurrent infections, and severe pain response during photodynamic therapy should undergo close surveillance and monitoring, and may need additional photodynamic therapy sessions. Infection with a single strain of HPV, and mucosal or subclinical infections are more likely to be cleared after three courses of ALA-PDT treatment. These findings may improve the efficiency of ALA-PDT in clinical practice.


Assuntos
Alphapapillomavirus , Condiloma Acuminado , Infecções por Papillomavirus , Fotoquimioterapia , Verrugas , Ácido Aminolevulínico/uso terapêutico , Condiloma Acuminado/tratamento farmacológico , Humanos , Papillomaviridae , Infecções por Papillomavirus/tratamento farmacológico , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/uso terapêutico , Estudos Retrospectivos , Verrugas/tratamento farmacológico
18.
Photodiagnosis Photodyn Ther ; 35: 102454, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34303875

RESUMO

BACKGROUND: Multiple human papillomavirus infections are commonly encountered in genital warts. Infection can be eliminated using 5-aminolevulinic acid-based photodynamic therapy. The aim of this study was to identify the preponderant genotypes and patterns of human papillomavirus co-infection clearance during photodynamic therapy in patients with genital warts. METHODS: We conducted a retrospective study between January 2020 and February 2021 at two hospitals in Guangzhou, China. Human papillomavirus typing and quantitative detection were performed before starting treatment and after each session of photodynamic therapy. RESULTS: A total of 97 patients participated in the study. Co-infections with low-risk and high-risk types were common in genital warts. Types 6 was the most common type detected, followed by types 52, 11, 58, 51 and 56. Patients with multiple infections were more likely to have high-risk human papillomavirus infection. The viral load of high-risk human papillomavirus before treatment was significantly lower than that of low-risk human papillomavirus, and decreased faster during therapy. In addition, high-risk types were cleared more readily than low-risk types, and 51.4% of high-risk types were eliminated after three rounds of therapy. A transient increase in viral load, especially low-risk types, was observed after two sessions of therapy. CONCLUSIONS: Low-risk human papillomavirus was preponderant in patients co-infected with low-risk and high-risk types. Photodynamic therapy effectively eliminated multiple human papillomavirus infections. The response to photodynamic therapy was mainly determined by the low-risk types in patients infected with combinations of low-risk and high-risk types.


Assuntos
Alphapapillomavirus , Condiloma Acuminado , Infecções por Papillomavirus , Fotoquimioterapia , Verrugas , Ácido Aminolevulínico/uso terapêutico , Condiloma Acuminado/tratamento farmacológico , Humanos , Papillomaviridae , Infecções por Papillomavirus/tratamento farmacológico , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/uso terapêutico , Estudos Retrospectivos , Verrugas/tratamento farmacológico
19.
Nanomaterials (Basel) ; 11(3)2021 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-33803453

RESUMO

Although various phenomena have confirmed that surface geometry has an impact on surface energy at micro/nano scales, determining the surface energy on micro/nano curved surfaces remains a challenge. In this paper, based on Lennard-Jones (L-J) pair potential, we study the geometrical effect on surface energy with the homogenization hypothesis. The surface energy is expressed as a function of local principle curvatures. The accuracy of curvature-based surface energy is confirmed by comparing surface energy on flat surface with experimental results. Furthermore, the surface energy for spherical geometry is investigated and verified by the numerical experiment with errors within 5%. The results show that (i) the surface energy will decrease on a convex surface and increase on a concave surface with the increasing of scales, and tend to the value on flat surface; (ii) the effect of curvatures will be obvious and exceed 5% when spherical radius becomes smaller than 5 nm; (iii) the surface energy varies with curvatures on sinusoidal surfaces, and the normalized surface energy relates with the ratio of wave height to wavelength. The curvature-based surface energy offers new insights into the geometrical and scales effect at micro/nano scales, which provides a theoretical direction for designing NEMS/MEMS.

20.
Waste Manag ; 126: 266-273, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33789215

RESUMO

Consumption of copper and aluminum has increased significantly in recent years; therefore, recycling these elements from the end-of-life vehicles (ELVs) will be of great economic value and social benefit. However, the separation of non-ferrous materials is difficult because of their different sources, various shapes and sizes, and complex surface conditions. In experimental study on the separation of these materials, few non-ferrous metal scraps can be used. To address these limitations, a traditional image recognition model and a small sample multi-target detection model (which can detect multiple targets simultaneously) based on deep learning and transfer learning were used to identify non-ferrous materials. The improved third version of You Only Look Once (YOLOv3) multi-target detection model using data augmentation, the loss function of focal loss, and a method of adjusting the threshold of Intersection over Union (IOU) between candidate bound and ground truth bound has superior target detection performance than methods. We obtained a 95.3% and 91.4% accuracy in identifying aluminum and copper scraps, respectively, and an operation speed of 18 FPS, meeting the real-time requirements of a sorting system. By using the improved YOLOv3 multi-target detection algorithm and equipment operation parameters selected, the accuracy and purity of the separation system exceeded 90%, meeting the needs of actual production.


Assuntos
Aprendizado Profundo , Algoritmos , Alumínio , Metais , Reciclagem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA