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1.
Artigo em Inglês | MEDLINE | ID: mdl-38656847

RESUMO

This article aims to solve the video object segmentation (VOS) task in a scribble-supervised manner, in which VOS models are not only initialized with sparse target scribbles for inference but also trained by sparse scribble annotations. Thus, the annotation burdens for both initialization and training can be substantially lightened. The difficulties of scribble-supervised VOS lie in two aspects: 1) it demands a strong reasoning ability to carefully segment the target given only a sparse initial target scribble and 2) it necessitates learning dense prediction from sparse scribble annotations during training, requiring powerful learning capability. In this work, we propose a reliability-guided hierarchical memory network (RHMNet) for this task, which segments the target in a stepwise expanding strategy w.r.t. the memory reliability level. To be specific, RHMNet maintains a reliability-guided memory bank. It first uses the high-reliability memory to locate the region with high reliability belonging to the target, i.e., highly similar to the initial target scribble. Then, it expands the located high-reliability region to the entire target conditioned on the region itself and all existing memories. In addition, we propose a scribble-supervised learning mechanism to facilitate the model learning for dense prediction. It exploits the pixel-level relations within a single frame and the instance-level variations across multiple frames to take full advantage of the scribble annotations in sequence training samples. The favorable performance on four popular benchmarks demonstrates that our method is promising. Our project is available at: https://github.com/mkg1204/RHMNet-for-SSVOS.

2.
Sci Total Environ ; 924: 171573, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38462005

RESUMO

The critical impacts of microclimate on carbon (C) cycling have been widely reported. However, the potential effects of global change on wetland microclimate remain unclear, primarily because of the absence of field manipulative experiment in inundated wetland. This study was designed to examine the effects of nighttime warming and nitrogen (N) addition on air, water, and sediment temperature and also reveal the controlling factors in a Phragmites australis dominated freshwater wetland on the North China Plain. Nighttime warming increased daily air, water, and sediment temperature by 0.24 °C, 0.27 °C, and 0.36 °C, respectively. The diurnal temperature range of water was decreased by 0.44 °C under nighttime warming, whereas warming had no effect on diurnal temperature range of air and sediment. In addition, N addition caused a reduction of 0.20 °C and 0.14 °C in daily water and sediment temperature by increasing vegetation coverage. There was a significant interaction between nighttime warming and N addition on water temperature. Furthermore, the vapor pressure deficit is the main factor affecting the extent of the warming-induced increases in air temperature. The changes of height and leaf area index of Phragmites australis are responsible for the cooling effects in the N addition plots. This study provides empirical evidence for the positive climate warming - microclimate feedback in freshwater wetland. However, N deposition leads to decreased water and sediment temperature. Our findings highlight the importance of incorporating the differential impacts of nighttime warming and N addition on air, water, and sediment temperature into the predictions of wetland C cycling responses to climate change.

3.
Food Sci Biotechnol ; 32(14): 2093-2104, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37860745

RESUMO

Three different Akebia trifoliata fruit juices were prepared, and their effects on modulation of human fecal microbiota were elucidated through an anaerobic fermentation in vitro. Results indicated that the introduction of inoculatedly-fermented Akebia trifoliata fruit juice promoted short-chain fatty acids productivity. Fecal microbiota analysis demonstrated up-regulations for abundances of Limosilactobacillus, Megamonas, Bifidobacterium, and Escherichia_Shigella, and down-regulations for numbers of Bacteroides, Prevotella_9, Parasutterella, and Sutterella. Correlation analysis confirmed relationships among sample components, short-chain fatty acids productivity, and microbial abundances, suggesting that sugars and organic acids stimulated growth of Actinobacteriota and suppressed proliferation of Proteobacteria, thus uncovering the underlying mechanism for the better ability of inoculatedly-fermented Akebia trifoliata fruit juice to regulate microbiota structure. Besides, clusters of orthologous groups of proteins analysis indicated that metabolite biosynthesis, energy metabolism, homeostasis maintenance and other physiological functions were ameliorated. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-023-01308-y.

4.
Cancer Med ; 12(21): 20573-20589, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37860928

RESUMO

BACKGROUND: Gastrointestinal cancer poses a serious health threat owing to its high morbidity and mortality. Although immune checkpoint blockade (ICB) therapies have achieved meaningful success in most solid tumors, the improvement in survival in gastrointestinal cancers is modest, owing to sparse immune response and widespread resistance. Metabolic reprogramming, autophagy, and ferroptosis are key regulators of tumor progression. METHODS: A literature review was conducted to investigate the role of the metabolic reprogramming, autophagy, and ferroptosis in immunotherapy resistance of gastrointestinal cancer. RESULTS: Metabolic reprogramming, autophagy, and ferroptosis play pivotal roles in regulating the survival, differentiation, and function of immune cells within the tumor microenvironment. These processes redefine the nutrient allocation blueprint between cancer cells and immune cells, facilitating tumor immune evasion, which critically impacts the therapeutic efficacy of immunotherapy for gastrointestinal cancers. Additionally, there exists profound crosstalk among metabolic reprogramming, autophagy, and ferroptosis. These interactions are paramount in anti-tumor immunity, further promoting the formation of an immunosuppressive microenvironment and resistance to immunotherapy. CONCLUSIONS: Consequently, it is imperative to conduct comprehensive research on the roles of metabolic reprogramming, autophagy, and ferroptosis in the resistance of gastrointestinal tumor immunotherapy. This understanding will illuminate the clinical potential of targeting these pathways and their regulatory mechanisms to overcome immunotherapy resistance in gastrointestinal cancers.


Assuntos
Ferroptose , Neoplasias Gastrointestinais , Neoplasias , Humanos , Neoplasias Gastrointestinais/tratamento farmacológico , Autofagia , Imunoterapia , Radioimunoterapia , Microambiente Tumoral
5.
Rev Sci Instrum ; 94(6)2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-37862498

RESUMO

Magnetic anomaly detection technologies have been widely used for tracking moving targets. In this paper, we present a fast-tracking method for magnetic abnormalities using a distributed Overhauser magnetometer system based on the genetic algorithm. Our proposed framework of the Overhauser magnetometer system employs multiple sensors to eliminate background interference, and the genetic algorithm efficiently solves magnetic anomaly data without requiring the derivation of the objective function. Test platforms were built to evaluate the distributed Overhauser magnetometer system and the genetic algorithm. Results from the natural outdoor magnetism laboratories showed that the noise of our presented magnetometers was below 0.134 nT. The optimal factors for solution precision and effectiveness in the genetic algorithm were obtained from the simulation. Moreover, the outdoor tracking experiments indicated that the proposed method could accurately and quickly detect the moving ferromagnetic object within 6.9% maximum positioning error in 0.55 m, and the tracking precision of the object velocity can get 5.88% maximum error in 4.33 km/h.

6.
Sensors (Basel) ; 23(20)2023 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-37896730

RESUMO

The robotic surgery environment represents a typical scenario of human-robot cooperation. In such a scenario, individuals, robots, and medical devices move relative to each other, leading to unforeseen mutual occlusion. Traditional methods use binocular OTS to focus on the local surgical site, without considering the integrity of the scene, and the work space is also restricted. To address this challenge, we propose the concept of a fully perception robotic surgery environment and build a global-local joint positioning framework. Furthermore, based on data characteristics, an improved Kalman filter method is proposed to improve positioning accuracy. Finally, drawing from the view margin model, we design a method to evaluate positioning accuracy in a dynamic occlusion environment. The experimental results demonstrate that our method yields better positioning results than classical filtering methods.


Assuntos
Procedimentos Cirúrgicos Robóticos , Humanos , Procedimentos Cirúrgicos Robóticos/métodos , Percepção
7.
Sensors (Basel) ; 23(16)2023 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-37631840

RESUMO

Unmanned vehicles frequently encounter the challenge of navigating through complex mountainous terrains, which are characterized by numerous unknown continuous curves. Drones, with their wide field of view and ability to vertically displace, offer a potential solution to compensate for the limited field of view of ground vehicles. However, the conventional approach of path extraction solely provides pixel-level positional information. Consequently, when drones guide ground unmanned vehicles using visual cues, the road fitting accuracy is compromised, resulting in reduced speed. Addressing these limitations with existing methods has proven to be a formidable task. In this study, we propose an innovative approach for guiding the visual movement of unmanned ground vehicles using an air-ground collaborative vectorized curved road representation and trajectory planning method. Our method offers several advantages over traditional road fitting techniques. Firstly, it incorporates a road star points ordering method based on the K-Means clustering algorithm, which simplifies the complex process of road fitting. Additionally, we introduce a road vectorization model based on the piecewise GA-Bézier algorithm, enabling the identification of the optimal frame from the initial frame to the current frame in the video stream. This significantly improves the road fitting effect (EV) and reduces the model running time (T-model). Furthermore, we employ smooth trajectory planning along the "route-plane" to maximize speed at turning points, thereby minimizing travel time (T-travel). To validate the efficiency and accuracy of our proposed method, we conducted extensive simulation experiments and performed actual comparison experiments. The results demonstrate the superior performance of our approach in terms of both efficiency and accuracy.

8.
Sensors (Basel) ; 23(13)2023 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-37447978

RESUMO

This paper evaluates the potential application of Raman baselines in characterizing organic deposition. Taking the layered sediments (Stromatolite) formed by the growth of early life on the Earth as the research object, Raman spectroscopy is an essential means to detect deep-space extraterrestrial life. Fluorescence is the main factor that interferes with Raman spectroscopy detection, which will cause the enhancement of the Raman baseline and annihilate Raman information. The paper aims to evaluate fluorescence contained in the Raman baseline and characterize organic sedimentary structure using the Raman baseline. This study achieves spectral image fusion combined with mapping technology to obtain high spatial and spectral resolution fusion images. To clarify that the fluorescence of organic matter deposition is the main factor causing Raman baseline enhancement, 5041 Raman spectra were obtained in the scanning area of 710 µm × 710 µm, and the correlation mechanism between the gray level of the light-dark layer of the detection point and the Raman baseline was compared. The spatial distribution of carbonate minerals and organic precipitations was detected by combining mapping technology. In addition, based on the BI-IHS algorithm, the spectral image fusion of Raman fluorescence mapping and reflection micrograph, polarization micrograph, and orthogonal polarization micrograph are realized, respectively. A fusion image with high spectral resolution and high spatial resolution is obtained. The results show that the Raman baseline can be used as helpful information to characterize stromatolite organic sedimentary structure.


Assuntos
Algoritmos , Carbonatos , Compostos Orgânicos , Análise Espectral Raman/métodos
9.
Medicine (Baltimore) ; 102(21): e33775, 2023 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-37233428

RESUMO

Pancreatic cancer is a highly malignant cancer with a poor prognosis. Owing to the strong drug resistance of pancreatic cancer, adjuvant chemotherapy has failed to achieve good results in clinical practice. The expression profile data of circular RNA (circRNA) (GSE110580), microRNA (miRNA) (GSE79234), and messenger RNA (mRNA) (GSE140077, GES35141) were obtained from the gene expression omnibus database. The Cancer-Specific circRNA Database identified the structural pattern of circRNA, and the starBase and circBank databases together predicted the miRNA of circRNA. The mirDIP database predicts the target mRNAs of miRNAs and identifies the ceRNA network of circRNA-miRNA-mRNA via negative regulatory mechanisms. The final validation was performed using clinical data from the cancer treatment response gene signature database of patients treated with gemcitabine for pancreatic cancer of the cancer genome atlas. By differential expression analysis, 22 differential circRNAs (8 upregulated and 14 downregulated), 70 differential microRNAs (37 upregulated and 33 downregulated), and 256 differential messenger RNA (DEmRNA) (161 upregulated and 95 downregulated) were obtained. Gene ontology and Kyoto encyclopedia of genes and genomes enrichment analyses showed that DEmRNAs were associated with drug response, exogenous cellular stimulation, and the tumor necrosis factor signaling pathway. The screened downregulated differential circular RNA (hsa_circ_0007401), upregulated differential microRNA (hsa-miR-6509-3p), and downregulated DEmRNA (FLI1) were consistent with the negative regulation mechanism of the ceRNA network, and FLI1 was significantly downregulated in the data of gemcitabine-resistant pancreatic cancer patients in the cancer genome atlas (n = 26).


Assuntos
MicroRNAs , Neoplasias Pancreáticas , Humanos , RNA Circular/genética , Gencitabina , MicroRNAs/genética , MicroRNAs/metabolismo , RNA Mensageiro/metabolismo , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/genética , Redes Reguladoras de Genes , Neoplasias Pancreáticas
10.
Molecules ; 28(9)2023 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-37175305

RESUMO

The efficient biosynthesis of chiral amines at an industrial scale to meet the high demand from industries that require chiral amines as precursors is challenging due to the poor stability and low catalytic efficiency of ω-transaminases (ω-TAs). Herein, this study adopted a green and efficient solvent engineering method to explore the effects of various aqueous solutions of deep eutectic solvents (DESs) as cosolvents on the catalytic efficiency and stability of ω-TA. Binary- and ternary-based DESs were used as cosolvents in enhancing the catalytic activity and stability of a ω-TA variant from Aspergillus terreus (E133A). The enzyme exhibited a higher catalytic activity in a ternary-based DES that was 2.4-fold higher than in conventional buffer. Moreover, the thermal stability was enhanced by a magnitude of 2.7, with an improvement in storage stability. Molecular docking studies illustrated that the most potent DES established strong hydrogen bond interactions with the enzyme's amino acid, which enhanced the catalytic efficiency and improved the stability of the ω-TA. Molecular docking is essential in designing DESs for a specific enzyme.


Assuntos
Solventes Eutéticos Profundos , Transaminases , Transaminases/metabolismo , Simulação de Acoplamento Molecular , Aminoácidos , Solventes/química , Aminas/química
11.
Sensors (Basel) ; 23(4)2023 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-36850588

RESUMO

Online detection of yarn roll's margin is one of the key issues in textile automation, which is related to the speed and scheduling of bobbin (empty yarn roll) replacement. The actual industrial site is characterized by uneven lighting, restricted shooting angles, diverse yarn colors and cylinder yarn types, and complex backgrounds. Due to the above characteristics, the neural network detection error is large, and the contour detection extraction edge accuracy is low. In this paper, an improved neural network algorithm is proposed, and the improved Yolo algorithm and the contour detection algorithm are integrated. First, the image is entered in the Yolo model to detect each yarn roll and its dimensions; second, the contour and dimensions of each yarn roll are accurately detected based on Yolo; third, the diameter of the yarn rolls detected by Yolo and the contour detection algorithm are fused, and then the length of the yarn rolls and the edges of the yarn rolls are calculated as measurements; finally, in order to completely eliminate the error detection, the yarn consumption speed is used to estimate the residual yarn volume and the measured and estimated values are fused using a Kalman filter. This method overcomes the effects of complex backgrounds and illumination while being applicable to different types of yarn rolls. It is experimentally verified that the average measurement error of the cylinder yarn diameter is less than 8.6 mm, and the measurement error of the cylinder yarn length does not exceed 3 cm.

12.
J Biotechnol ; 364: 66-74, 2023 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-36708998

RESUMO

As versatile and green biocatalysts for the asymmetric amination of ketones, the insufficient thermostability of transaminases always limits its broad application in the pharmaceutical and fine chemical industries. Here, synthetic shuffling technology was used to enhance stability of (R)-selective transaminase from Aspergillus terreus. The results showed that 30 out of 5000 mutants had improved thermostability by color-based screening method, among which mutants with residual enzyme activity higher than 50% at 45 °C for 10 min were selected for further analysis. Especially, the half-inactivation temperature (T5010), half-life (t1/2), and melting temperature (Tm) of the best mutant M14 (M280C-H210N-M150C-F115L) were 13.7 °C, 165.8 min, and 13.9 °C higher than that of the wild type (WT), respectively. M14 also exhibited a significant biocatalytic efficiency toward acetophenone and 1-acetylnaphthalene, the yield of which were 265.6% and 117.5% higher than WT, respectively. Based on molecular dynamics simulation, improved catalytic efficiency of M14 could be attributed to its increased hydrogen bonds interaction around the mutation sites. Additionally, the introduction of disulfide bond combined with above mutations has a synergistic effect on the improved protein thermostability.


Assuntos
Aspergillus , Transaminases , Transaminases/metabolismo , Estabilidade Enzimática , Temperatura
13.
Altern Ther Health Med ; 29(2): 264-270, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36399081

RESUMO

Context: The main pathological features of jaw cysts are bone defects. Obtaining autologous bone for transplantation repair has been associated with postoperative complications, and the amount of bone that dentist can collect is limited. Studies have found that autologous tooth bone powder is safe and has good bone-formation ability and stability. Objective: The study intended to examine the efficacy of implantation of autologous tooth bone powder and inorganic bovine bone powder, after marsupialization and second-stage curettage for large jaw cysts that dentist can't directly remove by surgery in clinical practice. Design: The research team designed a prospective randomized controlled trial. Setting: The study took place in the Head and Neck Surgery Department at Chongqing University Cancer Hospital in Chongqing, China. Participants: Participants were 60 patients at the hospital between 2016 and 2018 who had mandibular cysts that surgical operation couldn't directly remove by surgery in clinical practice. Intervention: At 4 months after curettage, the research team randomly divided participants into three groups: (1) an intervention group who received implants of autologous tooth bone powder into the bone defects, (2) a positive control group who received implants of inorganic bovine bone powder, and (3) a negative control group who received no implants of any material. Outcome Measures: The research team performed: (1) periodontal probing at a fixed anatomical point for the intervention and both control groups postintervention at one day and 4 months after surgery and recorded the changes in probing depth and (2) computed tomography (CT) scans at baseline one day before and postintervention at 4 months after the implantation to determine changes in the bone mineral density and compared them among the three groups. Results: The change in the height of the intervention group's fixed anatomical point postintervention at 4 months after surgery was significantly smaller than that of the positive control group (P < .05). In the CT scan analysis, the differences between the intervention and negative control groups and between the positive and negative control groups were statistically significant (P < .05); however, the difference between the intervention and positive control groups wasn't significant (P > .05). Conclusions: Autologous tooth bone powder and inorganic bovine bone powder can effectively repair bone defects caused by large jaw cysts and that the repaired effect may be better than that of spontaneous osteogenesis. The autologous tooth bone powder was associated with lower levels of bone loss than those seen with use of inorganic bovine bone powder.


Assuntos
Cistos Maxilomandibulares , Humanos , Animais , Bovinos , Pós , Estudos Prospectivos , China
14.
PLoS One ; 17(12): e0278890, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36580453

RESUMO

While corporate charitable giving(CG) can help firms obtain external innovation resource support, it can also crowd out internal innovation resources. The purpose of this study is to clarify the mechanism of CG and government green subsidies(GS) on green innovation(GI). In this regard, we integrated signaling theory and principal-agent theory to provide a new theoretical perspective for simultaneously focus on the impact of external resource acquisition and internal resource allocation on GI. We conducted a threshold regression analysis on the balanced panel data of 863 listed companies of China from 2016 to 2019 to clarify the input boundary between the promoting and inhibiting effects of corporate CG on corporate GI. And we further explored the relationship between GS and GI under the effect of different CG thresholds. Our findings indicate that there is an inverted U-shaped threshold effect of CG on GI. The impact of GS on GI shows a decreasing marginal benefit as the intensity of CG increases. Based on the findings, we propose corresponding countermeasures for the management of enterprises and the government.


Assuntos
Pessoal de Educação , Humanos , China , Limiar Diferencial , Governo , Orientação Espacial
15.
J Dent ; 126: 104286, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36096297

RESUMO

OBJECTIVES: To demonstrate a procedure for fusing images from cone-beam computed tomography (CBCT), magnetic resonance imaging (MRI) and optical positioning tracking system to dynamically evaluate the relative motion of the temporomandibular joint (TMJ) for the diagnosis of temporomandibular disorders (TMD). METHODS: CBCT data was collected from a patient wearing a fixation device with markers in the intercuspal position. The patient's mandibular movements were recorded using an optical positioning tracking system. The CBCT data were imported into a virtual simulation system to reproduce the mandibular movement. Five jaw positions were selected for 3D printing of the occlusal plate that the patient wore to undergo MRI. MRI scans were registered with the CBCT image for fusion and reconstruction. RESULTS: The anatomical structures of the articular fossa, articular disc, and condyle were clearly displayed in the CBCT-MRI fused images. The spatial posture and relative position of the fossa-disc-condyle during mandibular movement could be reproduced dynamically using the 3D reconstruction model. CONCLUSIONS: This method can visually display mandibular motion trajectories and the relative TMJ positions. Virtual reproduction provides a comprehensive understanding of the articular disc's morphology and position in different states from a 3D perspective. CLINICAL SIGNIFICANCE: This method can be used in clinical studies of TMJ as an adjunct to the 3D dynamic diagnosis and assessment for complex patients with TMD and provide relevant data for doctors.


Assuntos
Imageamento Tridimensional , Transtornos da Articulação Temporomandibular , Humanos , Imageamento Tridimensional/métodos , Côndilo Mandibular/diagnóstico por imagem , Côndilo Mandibular/patologia , Articulação Temporomandibular/diagnóstico por imagem , Transtornos da Articulação Temporomandibular/diagnóstico por imagem , Tomografia Computadorizada de Feixe Cônico/métodos
16.
Food Chem ; 397: 133763, 2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-35970057

RESUMO

ß-carotene and oleic acids are important molecules to distinguish between extra olive oil (EVOO) and other oils. To identify adulteration which use common vegetable oils blended with ß-carotene to imitate EVOO, a non-invasive, lossless method is proved to be effective. The present work presents a laser confocal Raman technique for analyzing and comparing the differences of molecule between EVOO and SSO, which based on theoretical Raman spectra of ß-carotene, oleic acids and linoleic acids calculated by density functional theory (DFT). Chemometrics based on support vector regression (SVR) was used to realize quantitative analysis of ß-carotene in synthetic olive oils. Nine different volume ratios were prepared independently, and test set evaluation index of linear kernel of SVR as follow: RMSE 0.0653, R2 0.9868. The results show that laser confocal Raman technique, combined with theoretical Raman spectra based on DFT, could analyze composition of vegetable oil accurately, and identify low-cost imitation of olive oil.


Assuntos
Contaminação de Alimentos , beta Caroteno , Contaminação de Alimentos/análise , Ácidos Oleicos , Azeite de Oliva/análise , Óleos de Plantas/análise , beta Caroteno/análise
17.
J Environ Radioact ; 251-252: 106959, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35830840

RESUMO

Glaciers, as the core part of the cryosphere, are very sensitive to climate change. As an indicator of glacier changes, the characteristics of glacier-originated rivers have profound significance to global climate change and local water resources. In this paper, the Mingyong River, a glacier-originated river replenished by groundwater, was selected to study the river hydrological cycle characteristics by integrating natural tracer radium isotopes with hydrochemical parameters. The results showed that there were significant differences in radium isotope activities and hydrochemical parameters between groundwater and river water, and the radium activities increased along the river, which reflected the fact that the river was supplied by groundwater seepage. We also found that the activity ratios of 224Ra/228Ra in river and groundwater were less than one unit, which indicated that the groundwater and river water circulated rapidly and that the radioactive equilibrium of short-time radium isotopes had not yet been reached. According to the geochemical behavior of radium in river water body, the mass balance equation of radium was established. 228Ra and 224Ra were used to estimate the groundwater seepage of different segments of the Mingyong River. The results demonstrated that the groundwater seepage fluxes calculated by 224Ra and 228Ra were similar and increased along the river from 123.12 to 657.68 m3 m-1 d-1. Our results have certain significance in revealing the characteristics of the local hydrological cycle and demonstrate that radium isotopes can be used as a tool to estimate the groundwater discharge of rivers in glacial environments.


Assuntos
Água Subterrânea , Monitoramento de Radiação , Rádio (Elemento) , Monitoramento Ambiental/métodos , Camada de Gelo , Isótopos , Rádio (Elemento)/análise , Rios , Água
18.
Front Nutr ; 9: 917432, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35769382

RESUMO

In this work, we exploited an efficient method to release hemicellulosic polysaccharides (BLHP) from bamboo (Phyllostachys pubescens Mazel) leaves assisted by a small amount of phosphotungstic acid. Structural unit analysis proved that BLHP-A1 and BLHP-B1 samples possessed abundant low-branch chains in →4)-ß-D-Xylp-(1→ skeleton mainly consisting of Xylp, Manp, Glcp, Galp, and Araf residues. According to the results of the antioxidant activity assays in vitro, both of the two fractions demonstrated the activity for scavenging DPPH⋅ and ABTS+ radicals and exhibited relatively a high reducing ability compared to the recently reported polysaccharides. Moreover, the antioxidant activities of purified polysaccharides were evaluated against H2O2-induced oxidative stress damage in HepG2 cells. BLHP-B1 showed more activity for preventing damages from H2O2 in HepG2 cells by improving the enzyme activities of SOD, CAT, and GSH-Px and decreasing the production of MDA as well as suppressing reactive oxygen species (ROS) formation. This study implied that BLHP could demonstrate its attenuation ability for oxidative stress in HepG2 cells.

19.
J Photochem Photobiol B ; 232: 112478, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35633610

RESUMO

This paper proposes a method to identify the blood of 4 poultry species (chicken, duck, goose and pigeon) based on Raman spectroscopy and its baseline. Samples were prepared by pretreatment methods of freezing, thawing, and dilution. The Raman spectra of dynamic blood and static blood were measured, respectively, and the spectral differences between the two research schemes were analyzed. The four species of poultry blood were identified based on the Raman spectroscopy and its baseline. The results show that the method can realize the identification of four species of poultry blood. In addition, the potential of Raman spectroscopy as a technique for determining carotenoids in blood has been clearly confirmed, which opens up the possibility to quickly determine whether poultry eats feed containing carotenoids without sample preparation.


Assuntos
Carotenoides , Análise Espectral Raman , Animais , Galinhas , Análise Espectral Raman/métodos
20.
Rev Sci Instrum ; 93(3): 035104, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-35365024

RESUMO

Fluxgate sensors are currently widely used for weak magnetic field measurement because of their relatively great performance, such as resolution, power consumption, and measurement of vector magnetic fields directly. Since the analog fluxgate sensor has some drawbacks, e.g., it would be influenced by the noise of the analog circuit. Hence, in recent years, the analog circuit is gradually inclined to be realized by digital processing in which the software parameter adjustment is employed to replace the analog components, which can greatly improve the flexibility of the design. This paper proposes a digital single-axis fluxgate sensor according to the cobalt-based amorphous effect. To be specific, the analog signal output by the fluxgate is sampled directly by an analog-to-digital converter to obtain the signal waveform in digital form after amplification. The demodulation, filtering, and integration of the signal are all solved by mathematical algorithms. Based on the working principle of the fluxgate sensor, the selection of the magnetic core material and coil winding method of the fluxgate sensor probe is introduced in detail. The design and function of the excitation circuit and preamplifier circuit, as well as the specific realization of digital signal processing, are described. Finally, the performance test of the digital fluxgate sensor was performed under laboratory conditions, and the magnetic anomaly detection comparison experiment was performed outdoors with commercial fluxgate sensors. To sum up, the linearity of the digital single-axis fluxgate sensor is better than 1 × 10-5, and the root mean square noise value is below 0.1 nT. At the same time, it has good magnetic field tracking performance and is extremely sensitive to the magnetic field of the measurement area.

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