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1.
Artigo em Inglês | MEDLINE | ID: mdl-38830306

RESUMO

Ionic current rectification (ICR) of charged conical nanopores has various applications in fields including nanofluidics, biosensing, and energy conversion, whose function is closely related to the dynamic response of nanopores. The occurrence of ICR originates from the ion enrichment and depletion in conical pores, whose formation is found to be affected by the scanning rate of voltages. Here, through time-dependent simulations, we investigate the variation of ion current under electric fields and the dynamic formation of ion enrichment and depletion, which can reflect the response time of conical nanopores. The response time of nanopores when ion enrichment forms, i.e., at the "on" state is significantly longer than that with the formation of ion depletion, i.e., at the "off" state. Our simulation results reveal the regulation of response time by different nanopore parameters including the surface charge density, pore length, tip, and base radius, as well as the applied conditions such as the voltage and bulk concentration. The response time of nanopores is closely related to the surface charge density, pore length, voltage, and bulk concentration. Our uncovered dynamic response mechanism of the ionic current can guide the design of nanofluidic devices with conical nanopores, including memristors, ionic switches, and rectifiers.

2.
Artigo em Inglês | MEDLINE | ID: mdl-38691150

RESUMO

Urinary tract infection (UTI) is one of the most prevalent bacterial infectious diseases worldwide. However, the resistance of urinary pathogens to other UTI antibiotics such as trimethoprim and trimethoprim/sulphamethoxazole increased. Pivmecillinam is a prodrug of mecillinam, which is effective for the treatment of urinary tract infections. The purpose of this study was to assess the safety, and pharmacokinetics of pivmecillinam and mecillinam after single- and multiple-dose oral administration of pivmecillinam tablets in healthy Chinese subjects. The study also investigated the profile of urinary excretion of mecillinam, as well as the effect of food and gender on the pharmacokinetics of pivmecillinam and mecillinam. This study was a single-center, open-label phase I study carried out in three groups. In total, 34 subjects were included in the study: group 1-food effect study with pivmecillinam 200 mg (n = 12); group 2-single- and multiple-dose study with pivmecillinam 400 mg (n = 12); group 3-single dose study with pivmecillinam 600 mg (n = 10). The plasma and urine concentrations of pivmecillinam and mecillinam were measured, and their pharmacokinetics were calculated. Treatment-emergent adverse events were evaluated and recorded in safety assessments for three groups. No severe adverse events were found in this study. After a single dose of pivmecillinam was taken orally, the maximum plasma concentration (Cmax) and the area under the concentration-time curve (AUC) of pivmecillinam increased in a dose-proportional manner, nor did mecillinam. Food had significant effects on Cmax and AUC0-t of pivmecillinam and Cmax of mecillinam. The mean cumulative percentage of urine excretion of mecillinam at 0 to 24 h ranged from 35.5 to 44.0%. Urinary cumulative excretion is relative to the drug dose, but the diet and multiple-dose administration did not affect the urinary cumulative excretion rate. The safety and pharmacokinetics of pivmecillinam and mecillinam after single- (200/400/600 mg) or multiple-dose (400 mg) administration were demonstrated in healthy Chinese subjects. Food affected the pharmacokinetics of pivmecillinam and mecillinam.

3.
Adv Mater ; : e2313209, 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38591644

RESUMO

Metal nanoparticle (NP) cocatalysts are widely investigated for their ability to enhance the performance of photocatalytic materials; however, their practical application is often limited by the inherent instability under light irradiation. This challenge has catalyzed interest in exploring high-entropy alloys (HEAs), which, with their increased entropy and lower Gibbs free energy, provide superior stability. In this study, 3.5 nm-sized noble-metal-free NPs composed of a FeCoNiCuMn HEA are successfully synthesized. With theoretic calculation and experiments, the electronic structure of HEA in augmenting the catalytic CO2 reduction has been uncovered, including the individual roles of each element and the collective synergistic effects. Then, their photocatalytic CO2 reduction capabilities are investigated when immobilized on TiO2. HEA NPs significantly enhance the CO2 photoreduction, achieving a 23-fold increase over pristine TiO2, with CO and CH4 production rates of 235.2 and 19.9 µmol g-1 h-1, respectively. Meanwhile, HEA NPs show excellent stability under simulated solar irradiation, as well high-energy X-ray irradiation. This research emphasizes the promising role of HEA NPs, composed of earth-abundant elements, in revolutionizing the field of photocatalysis.

4.
Food Sci Nutr ; 12(3): 2081-2092, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38455167

RESUMO

Chinese cooking is the primary treatment method for table food in China. The process is complex and large-scale, which is important to the macroeconomy and national nutrition and health. First, this article puts forward the concept of thermal accumulation for Chinese cooking by taking pork tenderloin fried at different oil temperatures, explaining changes in moisture content, hardness, and color with different thermal accumulation conditions, and measuring kinetic parameters. The variations of L* and b* obtained by the experimental results belong to the first-order reaction kinetic model, while the changes in water content and shear force belong to the zero-order reaction kinetic model. Simultaneously, the superheat value is used as a thermal accumulation indicator, combined with sensory evaluation to determine that the Z value of the human sensory overheating of pork tenderloin is 99°C, and O s,max (Z = 99°C, the reference temperature is 110°C) is 5.86 min.

5.
Neural Netw ; 171: 457-465, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38150871

RESUMO

Guaranteeing the monotonicity of a learned model is crucial to address concerns such as fairness, interpretability, and generalization. This paper develops a new monotonic neural network named Deep Isotonic Embedding Network (DIEN), which uses different modules to deal with monotonic and non-monotonic features respectively, and then combine outputs of these modules linearly to obtain the prediction result. A new embedding tool called Isotonic Embedding Unit is developed to process monotonic features and turn each one into an isotonic embedding vector. By converting non-monotonic features into a series of non-negative weight vectors and then combining them with isotonic embedding vectors that have special properties, we enable DIEN to guarantee monotonicity. Besides, we also introduce a module named Monotonic Feature Learning Network to capture complex dependencies between monotonic features. This module is a monotonic feedforward neural network with non-negative weights and can handle scenarios where there are few non-monotonic features or only monotonic features. In comparison to existing methods, DIEN does not require intricate structures like lattices or the use of additional verification techniques to ensure monotonicity. Additionally, the relationship between DIEN's inputs and outputs is obvious and intuitive. Results from experiments on both synthetic and real-world datasets demonstrate DIEN's superiority over existing methodologies.


Assuntos
Generalização Psicológica , Aprendizagem , Redes Neurais de Computação
6.
Sensors (Basel) ; 23(18)2023 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-37765736

RESUMO

For traditional imaging systems, high imaging quality and system miniaturization are often contradictory. In order to meet the requirements of high imaging quality and system miniaturization, this paper proposes a method to correct the aberration of coherent imaging optical systems. The method is based on the idea of phase recovery and the imaging principle of a coherent imaging system to recover the aberrations at the exit pupil of the system. According to the recovered aberrations, conjugate filters are constructed to correct the image quality in the frequency domain. The imaging quality of the system is improved without changing the original optical path, and the simplicity of the system is guaranteed. To solve the pupil frequency domain aberration more accurately, this paper adopts the dual competition and parallel recombination strategy based on the genetic algorithm and introduces the disaster model. The improved genetic algorithm can effectively restrain the appearance of the "precocity" phenomenon. Finally, the paraxial imaging optical path is simulated and verified by experiments. The results show that, after aberration correction, the image sharpness is improved and the edge information is richer, which verifies the feasibility of the coherent imaging system image quality enhancement method proposed in this paper.

7.
ACS Omega ; 8(32): 29836-29846, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37599935

RESUMO

Surface-enhanced Raman scattering (SERS) is a widely used rapid and noninvasive method for detecting biological substances in serum samples and is commonly employed in disease screening and diagnosis. Solid-state nanoarray SERS substrates used in serum detection may cause spectral instability due to imperfections in the detection method. For the purpose of identifying optimal detection conditions, various dilution levels of the serum were tested in this study. The study found that a complete and stable serum SERS spectrum can be obtained when the serum is diluted by a factor of 50. The study reports the successful preparation of an Au nanocone array (Au NCA) plasmonic substrate with a uniform, controllable microstructure and high activity, achieved through a combination of PS colloidal sphere template-assisted reactive ion etching (RIE) process and magnetron sputtering deposition technology. Based on this substrate, a standard detection scheme was developed to obtain highly stable and repeatable serum SERS spectra. The study verified the reliability of the optimized serum detection scheme by comparing the SERS spectra of serum samples from healthy individuals and gastric cancer patients, and confirmed the potential benefits of the scheme for disease screening and diagnosis.

8.
RSC Adv ; 13(35): 24692-24698, 2023 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-37601599

RESUMO

In order to study the relationship between the HLB value of oil and emulsion stabilization, the optimal formation of emulsification system was determined, and then, the properties of emulsion, such as particle size, stability, interfacial tension and zeta potential, were tested by laser particle analyzer, stability analyzer, and interfacial tensiometer. Experimental results showed that the optimal ratio of emulsification was Tween 80 : Span 80 = 5 : 5. Meanwhile, when the HLB value of the emulsification system was close to that of oil, the emulsion exhibited the best stability. This phenomenon is due to the fact that when the HLB values are close, the surfactant molecules are arranged more closely on the oil-water interface, leading to smaller sized emulsion droplet, which is conducive to emulsion stability. This study provides new insights into the effective adjustment of emulsion stability.

9.
Nanomaterials (Basel) ; 13(13)2023 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-37446532

RESUMO

Volatile organic compounds (VOCs), particularly monoaromatic hydrocarbon compounds (MACHs), pose a potential risk to the atmospheric environment and human health. Therefore, the progressive development of efficient detection methodologies is a pertinent need, which is still a challenge at present. In this study, we present a rapid and sensitive method to detect trace amounts of MACHs using a bifunctional SERS composite substrate. We prepared an Au/SiO2 enhanced layer and a porous Cu(OH)2 adsorption layer via microfluidic-assisted gas-liquid interface self-assembly. The composite substrate effectively monitored changes in benzaldehyde using time-varying SERS spectra, and track-specifically identified various VOCs such as benzene, xylene, styrene, and nitrobenzene. In general, the substrate exhibited a rapid response time of 20 s to gaseous benzaldehyde, with a minimum detection concentration of less than 500 ppt. Further experimental assessments revealed an optimum Cu(OH)2 thickness of the surrounding adsorption layer of 150 nm, which can achieve an efficient SERS response to MACHs. Furthermore, the recoverable and reusable property of the composite substrate highlights its practicality. This study presents a straightforward and efficient approach for detecting trace gaseous VOCs using SERS, with significant implications in the designing of SERS substrates for detecting other VOCs.

10.
J Hazard Mater ; 459: 132156, 2023 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-37523958

RESUMO

Styrene, a prevalent volatile organic compounds (VOCs), is very harmful to atmosphere and humans. Consequently, the development of efficient detection technologies for styrene is of high importance, which is still in challenge! In this work, we crafted a layered double hydroxide (LDH) porous film-coated gold nanoarray, designed to act as a surface enhanced Raman spectroscopy (SERS) chip for the efficient and portable detection of gaseous styrene. This chip features a covering layer composed of cross-linked LDH nanosheets, notable for their porous structure and high specific surface area. When the covering layer is 100-300 nm in thickness, this composite chip has significant enrichment effect and strong SERS performance to gaseous styrene with a lowest detectable concentration below 1 ppb (4.64 ×10-3 mg/m3), and can response within 10 s, showing the rapid response and high sensitivity. Additionally, the chip has strong anti-interference capabilities and maintains excellent response to styrene, even in mixed benzene-VOCs gases. The exceptional SERS performances of this chip is ascribed to its LDH covering layer-induced styrene-enrichment and structurally-enhanced SERS performances. This study provides a simple route and practical chip for the rapid and ultrasensitive SERS-based detection of gaseous styrene, which is also potentially beneficial for the detection of other gaseous VOCs.

11.
IEEE Trans Pattern Anal Mach Intell ; 45(12): 15406-15425, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37494160

RESUMO

Estimating human pose and shape from monocular images is a long-standing problem in computer vision. Since the release of statistical body models, 3D human mesh recovery has been drawing broader attention. With the same goal of obtaining well-aligned and physically plausible mesh results, two paradigms have been developed to overcome challenges in the 2D-to-3D lifting process: i) an optimization-based paradigm, where different data terms and regularization terms are exploited as optimization objectives; and ii) a regression-based paradigm, where deep learning techniques are embraced to solve the problem in an end-to-end fashion. Meanwhile, continuous efforts are devoted to improving the quality of 3D mesh labels for a wide range of datasets. Though remarkable progress has been achieved in the past decade, the task is still challenging due to flexible body motions, diverse appearances, complex environments, and insufficient in-the-wild annotations. To the best of our knowledge, this is the first survey that focuses on the task of monocular 3D human mesh recovery. We start with the introduction of body models and then elaborate recovery frameworks and training objectives by providing in-depth analyses of their strengths and weaknesses. We also summarize datasets, evaluation metrics, and benchmark results. Open issues and future directions are discussed in the end, hoping to motivate researchers and facilitate their research in this area.


Assuntos
Algoritmos , Telas Cirúrgicas , Humanos , Benchmarking , Modelos Estatísticos , Movimento (Física)
12.
Spectrochim Acta A Mol Biomol Spectrosc ; 302: 122977, 2023 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-37329830

RESUMO

The accurate, sensitive and portable detection of morphine is important to handle judicial cases, but remains to be a great challenge. In this work, a flexible route is presented for the accurate identification and efficient detection of trace morphine in solutions based on surface-enhanced Raman spectroscopy (SERS) and a solid substrate/chip. A gold-coated jagged silicon nanoarray (Au-JSiNA) is designed and prepared via Si-based polystyrene colloidal template-reactive ion etching and sputtering deposition of Au. Such Au-JSiNA has three-dimensional nanostructure with good structural uniformity, high SERS activity and hydrophobic surface. Adopting this Au-JSiNA as SERS chip, trace morphine in solutions could be detected and identified in both dropping and soaking ways, and the limit of detection is below 10-4 mg/mL. Importantly, such chip is especially suitable for the detection of trace morphine in aqueous solutions and even domestic sewage. The good SERS performance is attributed to the high-density nanotips and nanogaps on this chip as well as its hydrophobic surface. Additionally, the appropriate surface modification of this Au-JSiNA chip with 3-mercapto-1-propanol or 3-mercaptopropionic acid/1-(3-dimethylaminopropyl)-3-ethylcarbodiimide can further increase its SERS performances to morphine. This work provides a facile route and practical solid chip for SERS detection of trace morphine in solutions, which is significant to develop the portable and reliable instruments for on-site analysis of drugs in solutions.

13.
J Phys Chem Lett ; 14(17): 4113-4118, 2023 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-37129182

RESUMO

Molecular-level understandings of gas sensing mechanisms of oxide-based chemiresistors are significant for designing high-performance gas sensors; however, the mechanisms are still controversial due to the lack of direct experimental evidence. This work demonstrates efficient in situ surface-enhanced Raman spectroscopy (SERS) tracing of the highly representative SnO2-ethanol gas sensing using Au@SnO2 nanoparticles (NPs), where the Au core and SnO2 shell provide SERS activity and a gas sensing response, respectively. The in situ SERS evidence suggests that the sensing follows a Mars-van Krevelen mechanism rather than the prevailing adsorbed oxygen (AO) model. This mechanism is also observed in sensing other gases based on the Au@SnO2 NPs, showing its universality. This work offers efficient in situ tracing for gas sensing and experimental elucidation of the specific gas sensing mechanism, potentially ending the long-term controversy over the gas sensing mechanisms. Therefore, it is highly significant to this field.

14.
ACS Nano ; 17(11): 10300-10312, 2023 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-37234025

RESUMO

Significantly increasing the photothermal conversion of plasmonic nanostructured particles (PNPs) is a common goal for all applications of thermoplasmonics, but it is still in challenge, especially for PNPs with the morphology and composition required for a specific photothermal application. Here, we present a concept of defect-induced damping-enhanced photothermal conversion, which favors PNP intrinsic properties. A model of a defect-damped harmonic oscillator is established to depict photothermal conversion correlation with the structure of PNPs and is capable of accurately reproducing the optical performance of the PNPs with the local surface plasmon resonance far from the interband transition. The theoretical model analyses demonstrate that the defect-induced damping can significantly suppress the light scattering of the PNPs and effectively improve their photothermal conversion efficiency. Especially for the PNPs with a sufficiently large size (larger than ∼100 nm for Au and Ag), we show that defect-induced damping can significantly enhance their light absorption and photothermal performances. These are experimentally confirmed. Typically, defect-enriched Au nanostars with ∼100-150 nm profile size were fabricated and showed much higher photothermal performance and a big increment by 23% in photothermal conversion efficiency, compared with the normal (or defect-impoverished) counterpart. Furthermore, the in vitro and in vivo biological experiments demonstrate that this defect-enriched PNP can indeed exhibit significantly higher photothermal performance than the normal counterpart in cells and mouse tumors, which confirms the validity of the presented strategy in typical practical applications. This work provides a strategy to intrinsically and significantly enhance plasmonic photothermal conversion of PNPs with a sufficiently large size, which is not only suitable for PNPs with the morphology and composition required for specific applications but also can be combined with existing strategies to further increase their photothermal performance.

15.
IEEE Trans Pattern Anal Mach Intell ; 45(10): 12287-12303, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37126625

RESUMO

We present PyMAF-X, a regression-based approach to recovering a parametric full-body model from a single image. This task is very challenging since minor parametric deviation may lead to noticeable misalignment between the estimated mesh and the input image. Moreover, when integrating part-specific estimations into the full-body model, existing solutions tend to either degrade the alignment or produce unnatural wrist poses. To address these issues, we propose a Pyramidal Mesh Alignment Feedback (PyMAF) loop in our regression network for well-aligned human mesh recovery and extend it as PyMAF-X for the recovery of expressive full-body models. The core idea of PyMAF is to leverage a feature pyramid and rectify the predicted parameters explicitly based on the mesh-image alignment status. Specifically, given the currently predicted parameters, mesh-aligned evidence will be extracted from finer-resolution features accordingly and fed back for parameter rectification. To enhance the alignment perception, an auxiliary dense supervision is employed to provide mesh-image correspondence guidance while spatial alignment attention is introduced to enable the awareness of the global contexts for our network. When extending PyMAF for full-body mesh recovery, an adaptive integration strategy is proposed in PyMAF-X to produce natural wrist poses while maintaining the well-aligned performance of the part-specific estimations. The efficacy of our approach is validated on several benchmark datasets for body, hand, face, and full-body mesh recovery, where PyMAF and PyMAF-X effectively improve the mesh-image alignment and achieve new The project page with code and video results can be found at https://www.liuyebin.com/pymaf-x.

16.
Acta Biochim Biophys Sin (Shanghai) ; 55(8): 1184-1192, 2023 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-37021975

RESUMO

Autophagy plays a critical role in the physiology and pathophysiology of hepatocytes. High level of homocysteine (Hcy) promotes autophagy in hepatocytes, but the underlying mechanism is still unknown. Here, we investigate the relationship between Hcy-induced autophagy level and the expression of nuclear transcription factor EB (TFEB). The results show that Hcy-induced autophagy level is mediated by upregulation of TFEB. Silencing of TFEB decreases the level of autophagy-related protein LC3BII/I and increases p62 expression level in hepatocytes after exposure to Hcy. Moreover, the effect of Hcy on the expression of TFEB is regulated by hypomethylation of the TFEB promoter catalyzed by DNA methyltransferase 3b (DNMT3b). In summary, this study shows that Hcy can activate autophagy by inhibiting DNMT3b-mediated DNA methylation and upregulating TFEB expression. These findings provide another new mechanism for Hcy-induced autophagy in hepatocytes.


Assuntos
Autofagia , Metilação de DNA , Hepatócitos , Homocisteína , Autofagia/genética , DNA , Homocisteína/metabolismo , Homocisteína/farmacologia , Humanos , DNA Metiltransferase 3B
17.
Pediatr Res ; 94(2): 747-755, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-36864281

RESUMO

BACKGROUND: This study investigated the association between urinary epidermal growth factor (EGF) and complete remission (CR) of proteinuria in children with IgA nephropathy (IgAN). METHODS: We included 108 patients from the Registry of IgA Nephropathy in Chinese Children. The urinary EGF at the baseline and follow-up were measured and normalized by urine creatinine (expressed as uEGF/Cr). The person-specific uEGF/Cr slopes were estimated using linear mixed-effects models for the subset of patients with longitudinal data of uEGF/Cr. Cox models were used to analyze the associations of baseline uEGF/Cr and uEGF/Cr slope with CR of proteinuria. RESULTS: Patients with high baseline uEGF/Cr were more likely to achieve CR of proteinuria (adjusted HR 2.24, 95% CI: 1.05-4.79). The addition of high baseline uEGF/Cr on the traditional parameters significantly improved the model fit for predicting CR of proteinuria. In the subset of patients with longitudinal data of uEGF/Cr, high uEGF/Cr slope was associated with a higher likelihood of CR of proteinuria (adjusted HR 4.03, 95% CI: 1.02-15.88). CONCLUSIONS: Urinary EGF may be a useful noninvasive biomarker for predicting and monitoring CR of proteinuria in children with IgAN. IMPACT: High levels of baseline uEGF/Cr (>21.45 ng/mg) could serve as an independent predictor for CR of proteinuria. The addition of baseline uEGF/Cr on the traditional clinical pathological parameters significantly improved the fitting ability for the prediction of CR of proteinuria. Longitudinal data of uEGF/Cr were also independently associated with CR of proteinuria. Our study provides evidence that urinary EGF may be a useful noninvasive biomarker in the prediction of CR of proteinuria as well as monitoring therapeutic response, thus guiding treatment strategies in clinical practice for children with IgAN.


Assuntos
Fator de Crescimento Epidérmico , Glomerulonefrite por IGA , Humanos , Criança , Glomerulonefrite por IGA/complicações , População do Leste Asiático , Taxa de Filtração Glomerular , Proteinúria , Creatinina , Biomarcadores
18.
Nephrology (Carlton) ; 28(5): 272-275, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36878861

RESUMO

Alport syndrome (AS) is a progressive renal disease characterized by hematuria and progressive renal failure. X-linked dominant (XLAS) is the major inheritance form, accounting for almost 80% of the cases, caused by mutations in COL4A5 genes. Klinefelter syndrome (KS) is the most common genetic cause of human male gonadal dysgenesis. AS and KS are both rare disease, there are only three cases of combined AS and KS in the literatures. Fanconi syndrome (FS) caused by AS is also very rare. We report here the first case combined AS, KS and FS in a Chinese boy. We suggest that the severe renal phenotype and FS might be due to the two homozygous COL4A5 variants in our boy, and cases of AS combined KS will be good research objects for X chromosome inactivation.


Assuntos
Síndrome de Fanconi , Síndrome de Klinefelter , Nefrite Hereditária , Humanos , Masculino , Colágeno Tipo IV/genética , População do Leste Asiático , Síndrome de Fanconi/diagnóstico , Síndrome de Fanconi/genética , Hematúria/genética , Síndrome de Klinefelter/complicações , Síndrome de Klinefelter/diagnóstico , Síndrome de Klinefelter/genética , Mutação , Nefrite Hereditária/complicações , Nefrite Hereditária/diagnóstico , Nefrite Hereditária/genética
19.
Int J Parasitol Parasites Wildl ; 20: 162-169, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36890989

RESUMO

Ticks and tick-borne diseases have negative impacts on the health of wild animals including endangered and vulnerable species. The giant panda (Ailuropoda melanoleuca), a vulnerable and iconic flagship species, is threatened by tick infestation as well. Not only can ticks cause anemia and immunosuppression in the giant panda, but also bacterial and viral diseases. However, previous studies regarding tick infestation on giant pandas were limited in scope as case reports from sick or dead animals. In this study, an investigation focusing on the tick infestation of a reintroduced giant panda at the Daxiangling Reintroduction Base in Sichuan, China was conducted. Ticks were routinely collected and identified from the ears of the giant panda from March to September in 2021. A linear model was used to test the correlation between tick abundance and climate factors. All ticks were identified as Ixodes ovatus. Tick abundance was significantly different among months. Results from the linear model showed temperature positively correlated to tick abundance, while air pressure had a negative correlation with tick abundance. To the best of our knowledge, this study is the first reported investigation of tick species and abundance on a healthy giant panda living in the natural environment, and provides important information for the conservation of giant pandas and other species sharing the same habitat.

20.
Nanomaterials (Basel) ; 13(4)2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36839101

RESUMO

Volatile organic compounds (VOCs) in indoor environments have typical features of multiple components, high concentration, and long duration. The development of gas sensors with high sensitivity to multiple VOCs is of great significance to protect human health. Herein, we proposed a sensitive ZnO/WO3 composite chemi-resistive sensor facilely fabricated via a sacrificial template approach. Based on the transferable properties of self-assembled monolayer colloidal crystal (MCC) templates, two-dimensional honeycomb-like ordered porous ZnO/WO3 sensing matrixes were constructed in situ on commercial ceramic tube substrates with curved and rough surfaces. The nanocomposite thin films are about 250 nm in thickness with large-scale structural consistency and integrity, which facilitates characteristic responses with highly sensitivity and reliability. Furthermore, the nanocomposite sensor shows simultaneous responses to multiple VOCs that commonly exist in daily life with an obvious suppression sensing for traditional flammable gases. Particularly, a detection limit of 0.1 ppm with a second-level response/recovery time can be achieved, which is beneficial for real-time air quality assessments. We proposed a heterojunction-induced sensing enhancement mechanism for the ZnO/WO3 nanocomposite film in which the formation of abundant heterojunctions between ZnO and WO3 NPs significantly increases the thickness of the electron depletion layer in the bulk film and improves the formation of active oxygen species on the surface, which is conducive to enhanced responses for reducing VOC gases. This work not only provides a simple approach for the fabrication of high-performance gas sensors but also opens an achievable avenue for air quality assessment based on VOC concentration detection.

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