Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
Int J Hyperthermia ; 40(1): 2122597, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36642421

RESUMO

OBJECTIVES: The outcome of balloon-based atherosclerosis thermoplasty is closely related to the temperature/stress distribution during the treatment. For precise prediction of a required thermal lesion in the heterogeneous and thin atherosclerotic vessel, a numerical model incorporating heat-induced tissue expansion or shrinkage and the strain caused by balloon dilation is necessary. METHODS: A fully coupled thermal-electrical-structural new model was established. The model features a heterogeneous structure including eccentric plaque, healthy artery and surrounding tissue. Tissue expansion/shrinkage and hyperelasticity material model were taken into consideration. Different heating strategies and plaque mechanical properties were investigated. The temperature distribution was compared with the traditional thermal-electrical coupled model. The possibility of thermoplasty treatment using balloons with different sizes was also explored. RESULTS: The temperature, the electrical intensity and the stress during the thermoplasty were obtained. Lower stress was found in the heating region where tissue shrinkage occurred. The ablation depth was predicted to be ∼0.42 mm larger without coupling the biomechanical influence. The mechanical properties and input condition significantly affect the temperature and stress distribution considering the small dimensions of the tissue. Besides, with a 12.5% reduction of balloon diameter, the largest Von Mises stress decreases by 25.4%. CONCLUSIONS: It is confirmed that a coupled thermal-electrical-structural model is needed for precise temperature prediction in the balloon-based thermoplasty of the heterogeneous and thin tissue. The model presented may help with future development of optimized treatment planning considering both ablation depth and minimum stress.


Assuntos
Aterosclerose , Temperatura Alta , Humanos , Temperatura
2.
Environ Geochem Health ; 45(6): 3669-3682, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36474059

RESUMO

Pentachlorophenol (PCP) has been widely used as an insecticide for killing oncomelania (the intermediate host of schistosome) in China and leads to severe environmental contamination. Poyang Lake, as the largest freshwater lake and bird habitat in China, was once a schistosomiasis epidemic area. In this study, the concentrations of PCP in water and aquatic products from Poyang Lake were determined and analyzed, and then the human health ambient water quality criteria (AWQC) was derived based on native parameters of Poyang Lake basin. Finally, a comprehensive analysis of the health risks of drinking water and different types of aquatic products consumption was carried out. The results showed that PCP concentrations were ranged from 0.01 to 0.43 µg/L in surface water and 3.90 to 85.95 µg/kg in aquatic products. Due to the carcinogenicity of PCP, the human health AWQC for PCP are 0.02 µg/L for consumption of water and organisms and 0.03 µg/L for consumption of organisms only. Deterministic and probabilistic risk analysis indicated that the non-carcinogenic risk of PCP were acceptable in Poyang Lake, while the carcinogenic risk cannot be ignored. The health risks of PCP caused by aquatic products consumption were higher than that by drinking water. The percentages of acceptable risk for the population in Poyang Lake Basin were 99.95% at acceptable level of 10-4. Based on the sensitivity analysis, the impact of PCP concentrations on health risk values ranged from 53 to 82%. The study provided valuable information for regional water quality criteria development and water quality assessment.


Assuntos
Água Potável , Pentaclorofenol , Humanos , Qualidade da Água , Lagos/análise , Pentaclorofenol/toxicidade , Pentaclorofenol/análise , Água Potável/análise , Medição de Risco , China/epidemiologia , Monitoramento Ambiental/métodos
3.
Opt Express ; 29(12): 18760-18768, 2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-34154125

RESUMO

We fabricated the freestanding "core-shell" AgNWs/ Ni mesh electrodes by employing AgNWs solution onto the freestanding Ni-mesh. The combination of AgNWs and Ni mesh resulted in higher electrical conductivity, thereby enhancing the electromagnetic interference (EMI) shielding effectiveness (SE). The hybrid freestanding electrode created highly effective transparent and flexible EMI shielding films, featuring an ultrathin thickness (3 µm), the high optical transparency of 93% at 550 nm, and a SE of 41.5 dB in the X-band, which exceeds that of 30 dB for a freestanding Ni-mesh (94%). We showed that the hybrid freestanding AgNWs/Ni-mesh film is a promising high-performance transparent and flexible EMI shielding material that satisfies the requirements for optoelectronic devices.

4.
Opt Express ; 29(16): 25254-25269, 2021 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-34614859

RESUMO

It has been a great challenge to design an extremely flexible and stretchable electrochromic device (ECD), due to the physical deformation and fracture of the conductive materials and supporting substrates after plenty of bending. To solve the aforementioned shortcoming of ECDs, in this paper, a self-supporting metal Ni gird electrode is mentioned, which discarded solid or flexible polymeric substrates, having outstanding features of extremely foldability (bending radius lower 50 µm), stretchability (stretching to 117.6%), excellent conductivity (sheet resistance lower 0.4 Ω/sq), high transmittance (about 90% in full spectra), and ultra-thin thickness (3.7 µm). By assembling the metal electrode, the electrochromic material and the hydrogel, a paper-thin, ultra-flexible, and stretchable ECD with an overall thickness of 113 µm was prepared, which could be attached to the manifold and undulating surface of things and be stretched without compromising the dynamic bleaching and coloration performance. The triple-layered and substrate-free ECD with excellent flexibility and wearability could serve as futuristic electronics used for multiple purposes, like flexible displays, camouflage wearables and medical monitoring, etc.

5.
Opt Express ; 28(18): 26531-26542, 2020 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-32906925

RESUMO

An efficient approach to obtain high shielding effectiveness (SE) in transparent shielding in an optical window field is proposed and demonstrated by fabricating an embedded double-layer metallic mesh (DLMM) comprised of randomly structured Ni meshes on both sides of a flexible substrate, employing a facile and low-cost double-sided nanoimprinting method. The unique nonperiodic random structure contributes to uniform diffraction and eliminates the Moiré fringe generated by double-layer periodic meshes, ensuring high imaging quality for optical applications. The designed DLMM films simultaneously achieve strong shielding in the X-band and high transmittance in the visible spectrum, demonstrating a high transmittance of 88.7% at the 550-nm wavelength and a SE of 46.9 dB at a frequency of 8.2 GHz. An ultra-high SE of 80 dB is achieved at 64.2% transmittance, which reveals the highest reported SE over a metallic mesh for transparent shielding, indicating the high potential for this transparent electromagnetic interference shielding material for practical optical applications.

6.
Biomed Eng Online ; 19(1): 44, 2020 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-32522205

RESUMO

BACKGROUND: Restenosis remains a challenge in the treatment of atherosclerosis due to damage to the endothelial layer and induced proliferation of smooth muscle cells. A novel radiofrequency (RF) heating strategy was proposed to selectively ablate atherosclerosis plaque and to thermally inhibit the proliferation of smooth muscle cells while keeping the endothelial cells intact. METHODS: To realize the proposed strategy, a new radiofrequency balloon catheter, consisting of three ports, a three-channel tube, a balloon and an electrode patch, was designed. To evaluate the feasibility of this new design, a phantom experiment with thermocouples measuring temperatures with different voltages applied to the electrodes was conducted. A numerical model was established to obtain the 3D temperature distribution. The heating ability was also evaluated in ex vivo diseased artery samples. RESULTS: The experimental results showed that the highest temperature could be achieved in a distance from the surface of the balloon as designed. The temperature differences between the highest temperature at 0.78 mm and those of the surface reached 9.87 °C, 12.55 °C and 16.00 °C under applied 15 V, 17.5 V and 20 V heating, respectively. In the circumferential direction, the heating region (above 50 °C) spread from the middle of the two electrodes. The numerical results showed that the cooling effect counteracted the electrical energy deposition in the region close to the electrodes. The thermal lesion could be directed to cover the diseased media away from the catheter surface. The ex vivo heating experiment also confirmed the selective heating ability of the device. The temperature at the targeted site quickly reached the set value. The temperature of the external surface was higher than the inner wall surface temperature of the diseased artery lumen. CONCLUSION: Both the experimental and numerical results demonstrated the feasibility of the newly designed RF balloon catheter. The proposed RF microelectrodes heating together with the cooling water convection can realize the desired heating in the deeper site of the blood vessel wall while sparing the thin layer of the endothelium.


Assuntos
Angioplastia com Balão/instrumentação , Aterosclerose/terapia , Ondas de Rádio , Eletrodos , Imagens de Fantasmas , Temperatura
7.
Opt Express ; 27(21): 29547-29557, 2019 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-31684214

RESUMO

Flexible electronics, as a futuristic technology, is presenting tremendous impact in areas of wearable displaying, energy saving, and adaptive camouflage. In this work, we constructed a simple triple-layered electrochemical device with high flexibility using the electroplated nickel (Ni) grid electrode and the multifunctional hydrogel. The Ni grid electrode with low resistance (0.5 Ω/sq), high optical transparency (84.8%) and good mechanical flexibility, is beneficial for efficient electron injection, while the transparent lithium chloride hydrogel functions simultaneously for ion storage, ion transportation and counter-conducting. The thin polymer poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT: PSS) film is utilized as the electrochromic (EC) material and it also distributes the electrons evenly for uniform coloration. The triple-layered EC architecture not only simplifies the manufacturing procedures but also improves the device performance in terms of optical contrast and mechanical robustness. The device shows fast response for coloration and bleaching with an absolute transmittance contrast of 40% and a contrast retention over 72% after 2500 bending cycles. The ability of the flexible electrochromic device for conformable attaching was also investigated without obvious performance degradation. The electroplated Ni grid electrode and the multifunctional hydrogel are advantageous in constructing flexible electrochromic devices in terms of the response time, the working stability and the bending capability, paving a way for next-generation flexible electronics.

8.
Drug Dev Ind Pharm ; 42(11): 1723-31, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27074758

RESUMO

The synchronous sustained-release of two drugs was desired urgently for patients needing combination therapy in long term. However, sophisticated technologies were used generally to realize the simultaneous delivery of two drugs especially those with different physico-chemical properties. The purpose of this study was to obtain the concurrent release of felodipine and metoprolol tartrate, two drugs with completely different solubilities, in a simple monolithic osmotic pump system (FMOP). Two types of blocking agents were used in monolithic osmotic pump tablets and the synchronous sustained-release of FMOP was acquired in vitro. The tablets were also administered to beagle dogs and the plasma levels of FMOP were determined by HPLC-MS/MS. The pharmacokinetic parameters were calculated using a non-compartmental model. Cmax of both felodipine and metoprolol from the osmotic pump tablets were lower, tmax and mean residence time of both felodipine and metoprolol from the osmotic pump tablets were longer significantly than those from immediate release tablets. These results verified prolonged release of felodipine and metoprolol tartrate from osmotic pump formulations. The similar absorption rate between felodipine and metoprolol in beagles was also obtained by this osmotic pump formulation. Therefore, it could be supposed that the accordant release of two drugs with completely different solubilities may be realized just by using monolithic osmotic pump technology.


Assuntos
Anti-Hipertensivos/administração & dosagem , Felodipino/administração & dosagem , Metoprolol/administração & dosagem , Comprimidos/administração & dosagem , Animais , Anti-Hipertensivos/farmacocinética , Preparações de Ação Retardada , Cães , Sistemas de Liberação de Medicamentos , Felodipino/farmacocinética , Humanos , Metoprolol/farmacocinética , Osmose , Solubilidade
9.
Drug Dev Ind Pharm ; 42(1): 12-18, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25830369

RESUMO

REQUIP XL, prolonged release formulation of ropinirole hydrochloride (RH) in market, could release ropinirole constantly and showed satisfactory therapeutic effect and good compliance. REQUIP XL was composed of more than 10 kinds of excipients and prepared by Geomatrix technology, which was complex and laborious. The purpose of this study was to obtain a dosage form of RH with similar in vitro release profile and bioequivalence in vivo compared to REQUIP XL. Osmotic pump tablet combined with fast release phase was selected as the delivery system of RH and similar release curves were obtained in different media. The tablets were also administered to beagle dogs and the pharmacokinetic parameters were calculated using a non-compartmental model. Cmax, tmax, mean residence time (MRT), and area under the curve from 0 to 24 h (AUC0-24) were 3.97 ± 0.53 ng/mL, 3.58 ± 0.49 h, 8.29 ± 0.93 h, and 35.20 ± 8.11 ng/mL c h for ropinirole osmotic pump tablets (ROPT) and 4.15 ± 1.07 ng/mL, 2.92 ± 0.49 h, 7.84 ± 1.09 h, and 34.34 ± 10.06 ng/mL c h for REQUIP XL. The log-transformed mean Cmax and AUC0-24 of ROPT were about 92.15% and 102.49% relative to that of REQUIP XL, respectively. The 90% confidence intervals of Cmax and AUC0-24 for ROPT were 75.69-115.31% and 88.89-122.30%, respectively. So it could be concluded that ROPT was uniform with REQUIP XL both in vitro and in beagles and the release profiles of Geomatrix technology may be obtained by osmotic pump combined with fast release technology.


Assuntos
Preparações de Ação Retardada/administração & dosagem , Agonistas de Dopamina/administração & dosagem , Composição de Medicamentos , Sistemas de Liberação de Medicamentos/métodos , Indóis/administração & dosagem , Síndrome das Pernas Inquietas/tratamento farmacológico , Animais , Área Sob a Curva , Química Farmacêutica , Preparações de Ação Retardada/farmacocinética , Preparações de Ação Retardada/uso terapêutico , Cães , Agonistas de Dopamina/farmacocinética , Agonistas de Dopamina/uso terapêutico , Excipientes/química , Humanos , Indóis/farmacocinética , Indóis/uso terapêutico , Osmose , Qualidade de Vida , Comprimidos , Equivalência Terapêutica
10.
Front Cell Infect Microbiol ; 14: 1360852, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38481665

RESUMO

Helicobacter pylori (H. pylori) eradication is pivotal for alleviating gastric mucosal inflammation and preventing the progression of gastric diseases. While antibiotic-based therapies have achieved significant success in H. pylori eradication, challenges such as antibiotic resistance, drug toxicity, side effects, nonadherence, inapplicability, and disruption of gastrointestinal microflora have emerged. Updated therapies are urgently needed to suppress H. pylori. Nature has provided multitudinous therapeutic agents since ancient times. Natural products can be a potential therapy endowed with H. pylori eradication efficacy. We summarize the basic information, possible mechanisms, and the latest research progress of some representative natural products in H. pylori eradication, highlighting their safety, accessibility, efficiency, and ability to overcome limitations associated with antibiotic application. This review highlights the potential therapeutic advantages of incorporating ethnomedicine into anti-H. pylori regimens. The findings of this review may provide insights into the development of novel natural products and expand the therapeutic options available for H. pylori eradication.


Assuntos
Infecções por Helicobacter , Helicobacter pylori , Humanos , Infecções por Helicobacter/tratamento farmacológico , Quimioterapia Combinada , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Medicina Tradicional
11.
Biomed Opt Express ; 15(1): 319-335, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38223193

RESUMO

Nonuniform rotational distortion (NURD) correction is vital for endoscopic optical coherence tomography (OCT) imaging and its functional extensions, such as angiography and elastography. Current NURD correction methods require time-consuming feature tracking/registration or cross-correlation calculations and thus sacrifice temporal resolution. Here we propose a cross-attention learning method for the NURD correction in OCT. Our method is inspired by the recent success of the self-attention mechanism in natural language processing and computer vision. By leveraging its ability to model long-range dependencies, we can directly obtain the spatial correlation between OCT A-lines at any distance, thus accelerating the NURD correction. We develop an end-to-end stacked cross-attention network and design three types of optimization constraints. We compare our method with two traditional feature-based methods and a CNN-based method on two publicly-available endoscopic OCT datasets. We further verify the NURD correction performance of our method on 3D stent reconstruction using a home-built endoscopic OCT system. Our method achieves a ∼3 × speedup to real time (26 ± 3 fps), and superior correction performance.

12.
Sci Total Environ ; 913: 169756, 2024 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-38171460

RESUMO

Triphenyl phosphate (TPhP) and tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) are common organophosphate esters (OPEs), which are used as additives in various industries. These compounds have been widely detected in aquatic environment, raising concerns about their adverse effects on aquatic organisms. In order to protect aquatic ecosystems, a total of 7 species were selected for acute and chronic toxicity tests in this study. The results indicated that TPhP and TDCIPP exhibited varying degrees of toxicity to aquatic organisms. The 96-h LC50 values ranged from 1.088 mg/L to 1.574 mg/L for TPhP and from 2.027 mg/L to 17.855 mg/L for TDCIPP. The 28-d LC10 values ranged from 0.023 mg/L to 0.177 mg/L for TPhP and from 0.300 mg/L to 1.102 mg/L for TDCIPP. The tested toxicity data, combined with collected toxicity data, were used to investigate the predicted no-effect concentration in water (PNECwater) of TPhP and TDCIPP by species sensitivity distribution (SSD) method. The results revealed PNECwater values of 6.35 and 38.0 µg/L for TPhP and TDCIPP, respectively. Furthermore, the predicted no-effect concentrations in sediment (PNECsed) were derived as 110 µg/kg dry weight (dw) for TPhP and 424 µg/kg dw for TDCIPP using the equilibrium partitioning (EqP) approach. Based on the toxicity data and PNECs, the ecological risk of these two chemicals in surface waters and sediments worldwide over the last decade were evaluated. The results indicated that TDCIPP posed negligible risk in aquatic ecosystems. However, TPhP showed potential risk in sediments, as indicated by the hazard quotients (HQs) exceeding 0.1. The results of joint probability curves (JPC) indicated that the probabilities of exceeding hazardous concentration for 1 % of species for TPhP in water and sediment were 0.33 % and 5.2 %, respectively. Overall, these findings highlight the need for continued monitoring and assessment of the presence and potential impacts of TPhP and TDCIPP in aquatic ecosystems.


Assuntos
Retardadores de Chama , Fosfatos , Fosfatos/toxicidade , Ecossistema , Monitoramento Ambiental/métodos , Retardadores de Chama/análise , Organofosfatos/toxicidade , Água , Medição de Risco , Organismos Aquáticos , Ésteres
13.
Front Neurol ; 15: 1367654, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38882689

RESUMO

Introduction: Limb motor dysfunction is one of the challenges in rehabilitation after cerebral ischemic stroke (CIS) and greatly affects the quality of life of patients. This study aims to investigate the central mechanisms of the curative effect with multimodal magnetic resonance imaging (MRI), which will provide additional evidence to support the application of Xingnao Kaiqiao (XNKQ) acupuncture. Methods and analysis: This trial is a randomized controlled trial. Patients who meet the criteria will be recruited and randomly divided into 2 groups. One group will receive acupuncture treatment and another group will not receive acupuncture treatment. Both groups will receive conventional treatment. In addition, 20 healthy individuals will be recruited who will not receive any treatment. The total course of treatment is 14 days. The primary outcome is multimodal MRI analysis. For safety assessment, adverse events will be observed and recorded. Ethics and dissemination: The study involving human subjects was reviewed and approved by the Ethics Committee of IRB of The First Teaching Hospital of Tianjin University of TCM (TYLL2023[K]031). This study complied with the Declaration of Helsinki. Written informed consent about this study was provided by the participants. The results of this study will be published in a peer-reviewed journal. Clinical trial registration: Chinese Clinical Trial Registration Center (ChiCTR2300078315) https://www.chictr.org.cn/.

14.
Front Med (Lausanne) ; 11: 1339747, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38947240

RESUMO

Background: Diabetic peripheral neuropathy (DPN) is one of the most common complications of diabetes mellitus, often causing pain or numbness in the patient's limbs and even leading to amputation and death. Elderly patients with DPN usually have higher morbidity and more severe results. Acupuncture has been widely used as an effective treatment for DPN in China. However, the efficacy of acupuncture in the treatment of DPN remains unclear. In this review, we aimed to explore the impact of acupuncture in alleviating symptoms of DPN. Method and analysis: Six databases were searched from inception to October 2023. We searched Medline, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), and three Chinese databases, namely China National Knowledge Infrastructure (CNKI), SinoMed, and Wanfang. All randomized controlled trials related to the effect of acupuncture on DPN will be included. There was no restriction in language or publication year. The primary outcome is the response rate. The secondary outcomes are the Toronto clinical scoring system (TCSS), nerve conduction velocities (NCVs), and blood glucose before and after the treatment. Two researchers will be responsible for the selection of study, data extraction, and assessment of study quality independently. RevMan V5.1.0 software will be used to assess the risk of bias and generate data. Results: We searched 4518 studies, among which 9 RCTs were considered eligible. Overall, acupuncture treatment had a higher response rate than controls (relative risk (RR), -2.87 [95% confidence interval (CI), -5.27 to -0.48], p = 0.02) and significantly alleviated the symptoms of DPN patients, reduced their blood glucose levels, and improved their NCVs compared to the control group. This study will provide a high-quality synthesis of current available evidence for the clinical treatment of DPN with this therapy. Conclusion: The results suggested that acupuncture might be effective in improving symptoms of DPN in elderly patients. Owing to the overall low quality of the literature included, we need more large-sample, high-quality, and low-bias studies to prove it.

15.
Bioengineering (Basel) ; 10(2)2023 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-36829656

RESUMO

(1) Background: A combination of radiofrequency (RF) volumetric heating and convection cooling has been proposed to realize plaque ablation while protecting the endothelial layer. However, the depth of the plaque and the thickness of the endothelial layer vary in different atherosclerotic lesions. Current techniques cannot be used to achieve penetrating heating for atherosclerosis with two targets (the specified protection depth and the ablation depth). (2) Methods: A tissue-mimicking phantom heating experiment simulating atherosclerotic plaque ablation was conducted to investigate the effects of the control parameters, the target temperature (Ttarget), the cooling water temperature (Tf), and the cooling water velocity (Vf). To further quantitatively analyze and evaluate the ablation depth and the protection depth of the control parameters, a three-dimensional model was established. In addition, a conformal penetrating heating strategy was proposed based on the numerical results. (3) Results: It was found that Ttarget and Tf were factors that regulated the ablation results, and the temperatures of the plaques varied linearly with Ttarget or Tf. The simulation results showed that the ablation depth increased with the Ttarget while the protection depth decreased correspondently. This relationship reversed with the Tf. When the two parameters Ttarget and Tfwere controlled together, the ablation depth was 0.47 mm-1.43 mm and the protection depth was 0 mm-0.26 mm within 2 min of heating. (4) Conclusions: With the proposed control algorithm, the requirements of both the ablation depth and the endothelium protection depth can be met for most plaques through the simultaneous control of Ttarget and Tf.

16.
Biomed Opt Express ; 14(7): 3294-3307, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37497504

RESUMO

Deep learning has been successfully applied to OCT segmentation. However, for data from different manufacturers and imaging protocols, and for different regions of interest (ROIs), it requires laborious and time-consuming data annotation and training, which is undesirable in many scenarios, such as surgical navigation and multi-center clinical trials. Here we propose an annotation-efficient learning method for OCT segmentation that could significantly reduce annotation costs. Leveraging self-supervised generative learning, we train a Transformer-based model to learn the OCT imagery. Then we connect the trained Transformer-based encoder to a CNN-based decoder, to learn the dense pixel-wise prediction in OCT segmentation. These training phases use open-access data and thus incur no annotation costs, and the pre-trained model can be adapted to different data and ROIs without re-training. Based on the greedy approximation for the k-center problem, we also introduce an algorithm for the selective annotation of the target data. We verified our method on publicly-available and private OCT datasets. Compared to the widely-used U-Net model with 100% training data, our method only requires ∼10% of the data for achieving the same segmentation accuracy, and it speeds the training up to ∼3.5 times. Furthermore, our proposed method outperforms other potential strategies that could improve annotation efficiency. We think this emphasis on learning efficiency may help improve the intelligence and application penetration of OCT-based technologies.

17.
Environ Sci Pollut Res Int ; 30(19): 54657-54665, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36879088

RESUMO

As an important commercial form of vanadium, vanadium pentoxide (V2O5) is widely used in various modern industries, and its environmental impacts and ecotoxicity have been extensively studied. In this research, the ecotoxicity of V2O5 to earthworms (Eisenia fetida) in soil was tested by exposure to V2O5 at a series of doses, and biochemical response indices, such as the superoxide dismutase (SOD) and catalase (CAT) enzyme activity and malondialdehyde (MDA) content, were analysed to determine the mechanism by which antioxidant enzymes respond to V2O5 exposure. The bioaccumulation factor (BAF) of vanadium pentoxide in the earthworms and soil was also measured to explore the bioaccumulation process of V2O5 in the test period. The results showed that the acute and subchronic lethal toxicity values of V2O5 towards E. fetida were 21.96 mg/kg (LC50, 14 days) and 6.28 mg/kg (LC10, 28 days), respectively. For the antioxidant enzymes, SOD and CAT were synchronously induced or inhibited within the time period, and the enzyme activity had a dose-effect relationship with the V2O5 concentration. MDA analysis indicated that lipid peroxidation in earthworms mainly occurred at the early stage and was eliminated slowly in the later stage during the test time. In addition, the BAFs were much less than 1, which indicated that V2O5 did not easily accumulate in earthworms, and the BAF was positively correlated with the exposure time and negatively linearly correlated with the V2O5 concentration in the soil. These results indicated that the bioconcentration and metabolic mechanism of V2O5 in earthworms differed with the different exposure concentrations, and bioaccumulation became balanced after 14-28 days in earthworms exposed to a relatively lower dose of V2O5. The analysis of the integrated biomarker response (IBR) index indicated that the trends of IBR values were positively related to the changing V2O5 concentration, and the IBR index could reflect the organism's sensitivity to the external stimulus of V2O5. The toxicity of V2O5 is mainly caused by V5+, which is also an important factor in formulating guidelines regarding vanadium levels in soil, and the test earthworm species (Eisenia fetida) is a sensitive biological indicator for risk assessments of vanadium oxidation in the soil.


Assuntos
Oligoquetos , Poluentes do Solo , Animais , Antioxidantes/metabolismo , Bioacumulação , Solo/química , Vanádio/toxicidade , Vanádio/análise , Poluentes do Solo/análise , Catalase/metabolismo , Estresse Oxidativo , Superóxido Dismutase/metabolismo , Biomarcadores/metabolismo , Malondialdeído/metabolismo
18.
Zhong Yao Cai ; 35(7): 1112-6, 2012 Jul.
Artigo em Zh | MEDLINE | ID: mdl-23252278

RESUMO

OBJECTIVE: To study the effect of polysaccharides from Radix Glycyrrhizae on migration and polyamines (putrescine, spermidine and spermine) contents of IEC-6 cell. METHODS: Cell migration model was induced by scratch method in each well,and the polyamines in IEC-6 cell was determined by pre-column derivation high performance liquid chromatography. The polysaccharides inhibited effect on migration and polyamines contents of IEC-6 cells, and on IEC-6 cell migration by DFMO (a polyamines synthesis inhibitor) and the polyamines contents in the cells were observed. RESULTS: The polysaccharides (50 mg/L or 100 mg/L) was able to promote the cell migration, reverse the cell migration inhibition by DFMO, enhance the IEC-6 cell polyamines (putrescine, spermidine and spermine) contents in the process of cell migration and reverse the reduction of polyamines (putrescine, spermidine and spermine) induced by DFMO. CONCLUSION: The effect of Radix Glycyrrhizae on the gastrointestinal mucosal damage repairing may be related to increasing polyamine content in cells and promoting cell migration.


Assuntos
Células Epiteliais/efeitos dos fármacos , Glycyrrhiza/química , Mucosa Intestinal/citologia , Poliaminas/metabolismo , Polissacarídeos/farmacologia , Animais , Linhagem Celular , Movimento Celular/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Medicamentos de Ervas Chinesas/farmacologia , Eflornitina/antagonistas & inibidores , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Raízes de Plantas/química , Ratos , Rizoma/química
19.
Bioengineering (Basel) ; 9(9)2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-36135020

RESUMO

As a safe and minimal-invasive modality, thermal therapy has become an effective treatment in cancer treatment. Other than killing the tumor cells or destroying the tumor entirely, the thermal modality results in profound molecular, cellular and biological effects on both the targeted tissue, surrounding environments, and even the whole body, which has triggered the combination of the thermal therapy with other traditional therapies as chemotherapy and radiation therapy or new therapies like immunotherapy, gene therapy, etc. The combined treatments have shown encouraging therapeutic effects both in research and clinic. In this review, we have summarized the outcomes of the existing synergistic therapies, the underlying mechanisms that lead to these improvements, and the latest research in the past five years. Limitations and future directions of synergistic thermal therapy are also discussed.

20.
Chemosphere ; 262: 127864, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32768751

RESUMO

Phthalate esters (PAEs) are a class of endocrine disruptors that are produced and used extensively in China. Given its presence in various products, a great quantity of PAEs flows into different aquatic systems each year. Hence, it is important to study the pollution levels and ecological risk of PAEs. This study investigated the distribution and seasonal variation of six priority PAEs in the surface water of Poyang Lake, the largest freshwater lake in China. In the wet season, the mean concentration of the total PAEs was 0.544 ± 0.173 µg/L, while the dry season concentration (1.003 ± 0.451 µg/L) nearly doubled. The most abundant PAE congeners were di-n-butyl phthalate (DBP), followed by bis (2-ethylhexyl) phthalate (DEHP). To evaluate the ecological risks in Poyang Lake, the predicted no-effect concentrations (PNECs) of four PAEs based on non-lethal effects were derived. For diethyl phthalate (DEP), butyl benzyl phthalate (BBP), DBP, and DEHP, the PNECs were 31.6, 3.30, 2.31, and 0.0210 µg/L, respectively. The tiered ecological risk assessment showed that DEP and BBP posed no risk in Poyang Lake. Meanwhile, DBP posed a potential risk in Poyang Lake, but the risk of DEHP was unacceptable and requires more actions. Specifically, the probabilities of exceeding the threshold for the protection of 95% of the aquatic organisms (HC5) were 3.30% and 4.43% for DEHP in the wet and dry season, respectively. This study provides an appropriate reference for the surface water management of PAE pollution in China.


Assuntos
Exposição Ambiental/análise , Ésteres/análise , Ácidos Ftálicos/análise , Poluentes Químicos da Água/análise , Organismos Aquáticos , China , Dibutilftalato , Disruptores Endócrinos , Lagos , Medição de Risco , Rios , Estações do Ano , Água
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA