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1.
Micromachines (Basel) ; 15(6)2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38930750

RESUMO

To address the requirements of sonar imaging, such as high receiving sensitivity, a wide bandwidth, and a wide receiving angle, an AlN PMUT with an optimized ratio of 0.6 for the piezoelectric layer diameter to backside cavity diameter is proposed in this paper. A sample AlN PMUT is designed and fabricated with the SOI substrate-based bulk MEMS process. The characterization test result of the sample demonstrates a -6 dB bandwidth of approximately 500 kHz and a measured receiving sensitivity per unit area of 1.37 V/µPa/mm2, which significantly surpasses the performance of previously reported PMUTs. The -6 dB horizontal angles of the AlN PMUT at 300 kHz and 500 kHz are measured as 68.30° and 54.24°, respectively. To achieve an accurate prediction of its characteristics when being packaged and assembled in a receive array, numerical simulations with the consideration of film stress are conducted. The numerical result shows a maximum deviation of ±7% in the underwater receiving sensitivity across the frequency range of 200 kHz to 1000 kHz and a deviation of about 0.33% in the peak of underwater receiving sensitivity compared to the experimental data. By such good agreement, the simulation method reveals its capability of providing theoretical foundation for enhancing the uniformity of AlN PMUTs in future studies.

2.
Nutrients ; 16(8)2024 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-38674860

RESUMO

Silymarin, salvianolic acids B, and puerarin were considered healthy food agents with tremendous potential to ameliorate non-alcoholic fatty liver disease (NAFLD). However, the mechanisms by which they interact with gut microbiota to exert benefits are largely unknown. After 8 weeks of NAFLD modeling, C57BL/6J mice were randomly divided into five groups and fed a normal diet, high-fat diet (HFD), or HFD supplemented with a medium or high dose of Silybum marianum extract contained silymarin or polyherbal extract contained silymarin, salvianolic acids B, and puerarin for 16 weeks, respectively. The untargeted metabolomics and 16S rRNA sequencing were used for molecular mechanisms exploration. The intervention of silymarin and polyherbal extract significantly improved liver steatosis and recovered liver function in the mice, accompanied by an increase in probiotics like Akkermansia and Blautia, and suppressed Clostridium, which related to changes in the bile acids profile in feces and serum. Fecal microbiome transplantation confirmed that this alteration of microbiota and its metabolites were responsible for the improvement in NAFLD. The present study substantiated that alterations of the gut microbiota upon silymarin and polyherbal extract intervention have beneficial effects on HFD-induced hepatic steatosis and suggested the pivotal role of gut microbiota and its metabolites in the amelioration of NAFLD.


Assuntos
Depsídeos , Dieta Hiperlipídica , Suplementos Nutricionais , Microbioma Gastrointestinal , Isoflavonas , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica , Silimarina , Animais , Microbioma Gastrointestinal/efeitos dos fármacos , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Dieta Hiperlipídica/efeitos adversos , Isoflavonas/farmacologia , Masculino , Camundongos , Silimarina/farmacologia , Benzofuranos/farmacologia , Fígado/metabolismo , Fígado/efeitos dos fármacos , Modelos Animais de Doenças , Ácidos e Sais Biliares/metabolismo , Extratos Vegetais/farmacologia
3.
Nutrients ; 16(7)2024 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-38613119

RESUMO

Resveratrol (RES) has been reported to prevent hyperuricemia (HUA); however, its effect on intestinal uric acid metabolism remains unclear. This study evaluated the impact of RES on intestinal uric acid metabolism in mice with HUA induced by a high-fat diet (HFD). Moreover, we revealed the underlying mechanism through metagenomics, fecal microbiota transplantation (FMT), and 16S ribosomal RNA analysis. We demonstrated that RES reduced the serum uric acid, creatinine, urea nitrogen, and urinary protein levels, and improved the glomerular atrophy, unclear renal tubule structure, fibrosis, and renal inflammation. The results also showed that RES increased intestinal uric acid degradation. RES significantly changed the intestinal flora composition of HFD-fed mice by enriching the beneficial bacteria that degrade uric acid, reducing harmful bacteria that promote inflammation, and improving microbial function via the upregulation of purine metabolism. The FMT results further showed that the intestinal microbiota is essential for the effect of RES on HUA, and that Lactobacillus may play a key role in this process. The present study demonstrated that RES alleviates HFD-induced HUA and renal injury by regulating the gut microbiota composition and the metabolism of uric acid.


Assuntos
Microbioma Gastrointestinal , Hiperuricemia , Animais , Camundongos , Hiperuricemia/tratamento farmacológico , Resveratrol/farmacologia , Ácido Úrico , Túbulos Renais , Inflamação
4.
Micromachines (Basel) ; 15(2)2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38398897

RESUMO

This paper proposes a system-in-package combination navigation chip. We used wire bonding, chip stacking, surface mount, and other processes to integrate satellite navigation chips, inertial navigation chips, microprocessor chips, and separation devices. Finally, we realized the hardware requirements for combined navigation in a 20 mm × 20 mm chip. Further, we performed a multi-physics simulation analysis of the package design. For antenna signals, the insertion loss was greater than -1 dB@1 GHz and the return loss was less than -10 dB@1 GHz. The amplitude of these noises of the signal between the MCU and the IMU was approximately 20%, and the maximum value of the coupling coefficient between signal lines on the top surface was 13.4174%. The ninth mode of the power plane yielded a maximum voltage of 55 mV, and all power delivery networks had a DC voltage drop of less than 2%. The highest temperature in the microsystem was approximately 42 °C. These results show that our design performed well in terms of signal, power, and thermal performance.

5.
ACS Appl Mater Interfaces ; 16(9): 11749-11757, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38381996

RESUMO

Wearable and implantable devices have gained significant popularity, playing a crucial role in smart healthcare and human-machine interfaces, which necessitates the development of more complex electronic devices and circuits on biocompatible flexible materials. Polylactic acid (PLA) stands out due to its biodegradability, cost-effectiveness, and low immunogenicity. In this study, we utilize a solution-based spin-coating method to produce high-quality PLA thin films, serving as substrates for the fabrication of thin-film transistors (TFTs) in which the dielectric layer material is silicon dioxide, the channel layer material is IGZO, and the gate, drain, and source material is ITO at low temperatures (<40 °C) through a shadow masking technique. The resulting PLA-TFT devices exhibited remarkable flexibility, biocompatibility, and impressive electrical characteristics, including a charge carrier mobility of 27.81 cm2/(V s), a subthreshold swing of 162.8 mV/decade, and an ON/OFF current ratio of up to 1 × 106, and maintained performance under various deformations. We successfully constructed fundamental logic gate circuits using PLA-TFTs, including AND, OR, and NOT gates, which effectively performed logical functions and demonstrated stability under diverse bending conditions. These research findings provide valuable support for future endeavors in fabricating intricate logic circuits and realizing advanced functionalities on biocompatible flexible materials.

6.
Nanoscale ; 16(6): 3191, 2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38294130

RESUMO

Correction for 'An interfacial toughening strategy for high stability 2D/3D perovskite X-ray detectors with a carbon nanotube thin film electrode' by Liwen Qiu et al., Nanoscale, 2023, 15, 14574-14583, https://doi.org/10.1039/D3NR02801A.

7.
Sheng Wu Gong Cheng Xue Bao ; 39(11): 4445-4462, 2023 Nov 25.
Artigo em Chinês | MEDLINE | ID: mdl-38013177

RESUMO

Plastics are widely used in human daily life, which bring great convenience. Nevertheless, the disposal of a large amount of plastic wastes also brings great pressure to the environment. Polyethylene terephthalate (PET) is a polymer thermoplastic material produced from petroleum. It has become one of the most commonly used plastics in the world due to its durability, high transparency, light weight and other characteristics. PET can exist in nature for a long time due to its complex structure and the difficulty in degradation, which causes serious pollution to the global ecological environment, and threatens human health. The degradation of PET wastes has since become one of the global challenges. Compared with physical and chemical methods, biodegradation is the greenest way for treating PET wastes. This review summarizes the recent advances on PET biodegradation including microbial and enzymatic degradation of PET, biodegradation pathway, biodegradation mechanisms, and molecular modification of PET-degrading enzymes. In addition, the prospect for achieveing efficient degradation of PET, searching and improving microorganisms or enzymes that can degrade PET of high crystallinity are presented, with the aimto facilitate the development, application and molecular modification of PET biodegradation microorganisms or enzymes.


Assuntos
Petróleo , Polietilenotereftalatos , Humanos , Polietilenotereftalatos/metabolismo , Polímeros , Biodegradação Ambiental
8.
Micromachines (Basel) ; 14(8)2023 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-37630067

RESUMO

The decreasing-width, increasing-aspect-ratio RDL presents significant challenges to the design for reliability (DFR) of an advanced package. Therefore, this paper proposes an ML-based RDL modeling and simulation method. In the method, RDL was divided into blocks and subdivided into pixels of metal percentage, and the RDL was digitalized as tensors. Then, an ANN-based surrogate model was built and trained using a subset of tensors to predict the equivalent material properties of each block. Lastly, all blocks were transformed into elements for simulations. For validation, line bending simulations were conducted on an RDL, with the reaction force as an accuracy indicator. The results show that neglecting layout impact caused critical errors as the substrate thinned. According to the method, the reaction force error was 2.81% and the layout impact could be accurately considered with 200 × 200 elements. For application, the TCT maximum temperature state simulation was conducted on a CPU chip. The simulation indicated that for an advanced package, the maximum stress was more likely to occur in RDL rather than in bumps; both RDL and bumps were critically impacted by layouts, and RDL stress was also impacted by vias/bumps. The proposed method precisely concerned layout impacts with few resources, presenting an opportunity for efficient improvement.

9.
Nanoscale ; 15(35): 14574-14583, 2023 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-37610065

RESUMO

Single-crystalline metal halide perovskite materials hold great promise for developing next-generation low-dose X-ray detection. To bring this new technology into reality, it is important to improve the durability of perovksite detectors by suppressing the well-known corrosion and ion diffusion problems at the perovskite/electrode interface. For imaging application, it is also imperative to develop new assembling approaches to realise non-planar interconnection between thick perovskite crystals and thin-film transistor (TFT) backplanes. Herein, a flexible and mechanically robust carbon nanotube (CNT) film was proposed to replace noble metal electrodes. The proposed CNT film, whose binder contains a carboxyl group, can form solid contact with a phenethylamine-based two-dimensional (2D) perovskite via amide coupling, thus toughening the perovskite-electrode interface. The resulting CNT/2D-3D perovskite detector shows an applaudable low dark current, high sensitivity, a low dose detection limit and excellent stability, retaining 98% of its initial sensitivity after storage for three months. Moreover, the flexible CNT films are also beneficial for making non-planar interconnection between thick perovskite crystals and TFT backplanes. The proposed flexible CNT thin film electrode thus provides a facile route towards realising a low-dose, high-resolution and highly stable perovskite X-ray detector.

10.
Nano Lett ; 23(18): 8399-8405, 2023 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-37339058

RESUMO

Stem cells possess exceptional proliferation and differentiation abilities, making them highly promising for targeted recruitment research in tissue engineering and other clinical applications. DNA is a naturally water-soluble, biocompatible, and highly editable material that is widely used in cell recruitment research. However, DNA nanomaterials face challenges, such as poor stability, complex synthesis processes, and demanding storage conditions, which limit their potential applications. In this study, we designed a highly stable DNA nanomaterial that embeds nucleic acid aptamers in the single strand region. This material has the ability to specifically bind, recruit, and capture human mesenchymal stem cells. The synthesis process involves rolling circle amplification and topological isomerization, and it can be stored for extended periods under varying temperatures and humidity conditions. This DNA material offers high specificity, ease of fabrication, simple preservation, and low cost, providing a novel approach to stem cell recruitment strategies.


Assuntos
Aptâmeros de Nucleotídeos , Nanoestruturas , Humanos , DNA , Engenharia Tecidual
11.
Polymers (Basel) ; 15(5)2023 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-36904490

RESUMO

Parylene C has been widely used in the fields of microelectromechanical systems (MEMS) and electronic device encapsulation because of its unique properties, such as biocompatibility and conformal coverage. However, its poor adhesion and low thermal stability limit its use in a wider range of applications. This study proposes a novel method for improving the thermal stability and enhancing the adhesion between Parylene and Si by copolymerizing Parylene C with Parylene F. The successful preparation of Parylene copolymer films containing different ratios of Parylene C and Parylene F was confirmed using Fourier-transform infrared spectroscopy and surface energy calculations. The proposed method resulted in the copolymer film having an adhesion 10.4 times stronger than that of the Parylene C homopolymer film. Furthermore, the friction coefficients and cell culture capability of the Parylene copolymer films were tested. The results indicated no degradation compared with the Parylene C homopolymer film. This copolymerization method significantly expands the applications of Parylene materials.

12.
Nutrients ; 15(3)2023 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-36771199

RESUMO

Resveratrol is a polyphenol with a well-established beneficial effect on dyslipidemia and hyperuricemia in preclinical experiments. Nonetheless, its efficacy and dose-response relationship in clinical trials remains unclear. This study examined whether resveratrol supplement improves the serum lipid profile and other metabolic markers in a dose-response manner in individuals with dyslipidemia. A total of 168 subjects were randomly assigned to placebo (n = 43) and resveratrol treatment groups of 100 mg/d (n = 41), 300 mg/d (n = 43), and 600 mg/d (n = 41). Anthropometric and biochemical parameters were analyzed at baseline and 4 and 8 weeks. Resveratrol supplementation for 8 weeks did not significantly change the lipid profile compared with the placebo. However, a significant decrease of serum uric acid was observed at 8 weeks in 300 mg/d (-23.60 ± 61.53 µmol/L, p < 0.05) and 600 mg/d resveratrol groups (-24.37 ± 64.24 µmol/L, p < 0.01) compared to placebo (8.19 ± 44.60 µmol/L). Furthermore, xanthine oxidase (XO) activity decreased significantly in the 600 mg/d resveratrol group (-0.09 ± 0.29 U/mL, p < 0.05) compared with placebo (0.03 ± 0.20 U/mL) after 8 weeks. The reduction of uric acid and XO activity exhibited a dose-response relationship (p for trend, <0.05). Furthermore, a marked correlation was found between the changes in uric acid and XO activity in the resveratrol groups (r = 0.254, p < 0.01). Resveratrol (10 µmol/L) treatment to HepG2 cells significantly reduced the uric acid levels and intracellular XO activity. Nevertheless, we failed to detect significant differences in glucose, insulin, or oxidative stress biomarkers between the resveratrol groups and placebo. In conclusion, resveratrol supplementation for 8 weeks had no significant effect on lipid profile but decreased uric acid in a dose-response manner, possibly due to XO inhibition in subjects with dyslipidemia. The trial was registered on ClinicalTrials.gov (NCT04886297).


Assuntos
Dislipidemias , Ácido Úrico , Humanos , Resveratrol , Suplementos Nutricionais , Lipídeos , Dislipidemias/tratamento farmacológico , Método Duplo-Cego
13.
Micromachines (Basel) ; 13(10)2022 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-36296020

RESUMO

The microfluidic device (MFD) with a glass−PDMS−glass (G-P-G) structure is of interest for a wide range of applications. However, G-P-G MFD fabrication with an ultra-thin PDMS film (especially thickness less than 200 µm) is still a big challenge because the ultra-thin PDMS film is easily deformed, curled, and damaged during demolding and transferring. This study aimed to report a thickness-controllable and low-cost fabrication process of the G-P-G MFD with an ultra-thin PDMS film based on a flexible mold peel-off process. A patterned photoresist layer was deposited on a polyethylene terephthalate (PET) film to fabricate a flexible mold that could be demolded softly to achieve a rigid structure of the glass−PDMS film. The thickness of ultra-thin patterned PDMS could reach less than 50 µm without damage to the PDMS film. The MFD showcased the excellent property of water evaporation inhibition (water loss < 10%) during PCR thermal cycling because of the ultra-thin PDMS film. Its low-cost fabrication process and excellent water evaporation inhibition present extremely high prospects for digital PCR application.

14.
Materials (Basel) ; 15(11)2022 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-35683145

RESUMO

Powder spreading is one of crucial steps in selective laser sintering (SLS), which controls the quality of the powder bed and affects the quality of the printed parts. It is not advisable to use empirical methods or trial-and-error methods that consume lots of manpower and material resources to match the powder property parameters and powder laying process parameters. In this paper, powder spreading in realistic SLS settings was simulated using a discrete element method (DEM) to investigate the effects of the powder's physical properties and operating conditions on the bed quality, characterized by the density characteristics, density uniformity, and flatness of the powder layer. A regression model of the powdering quality was established based on the response surface methodology (RSM). The relationship between the proposed powdering quality index and the research variables was well expressed. An improved multi-objective optimization algorithm of the non-dominated sorting genetic algorithm II (NSGA-II) was used to optimize the powder laying quality of nylon powder in the SLS process. We provided different optimization schemes according to the different process requirements. The reliability of the multi-objective optimization results for powdering quality was verified via experiments.

15.
Am J Clin Nutr ; 116(4): 1070-1077, 2022 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-35728041

RESUMO

BACKGROUND: Indole-3-propionic acid (IPA), a microbiota-produced tryptophan metabolite, has been shown to exhibit cardioprotective effects in animal models. However, the relation of IPA with cardiovascular risk in humans is currently unknown. OBJECTIVES: This prospective study aimed to investigate whether plasma tryptophan and IPA levels are associated with decreased risks of mortality. METHODS: Ultra-HPLC-MS/MS was used to measure plasma tryptophan and IPA levels in 1829 patients with coronary artery disease (CAD). Cox proportional hazards regression models were used to estimate the associations between tryptophan and IPA levels and the risks of cardiovascular and all-cause mortality. RESULTS: During the median 9.2-year follow-up, 424 all-cause deaths occurred, of which 272 were cardiovascular deaths. Plasma tryptophan and IPA levels were significantly associated with reduced risks of cardiovascular and all-cause mortality. Patients with CAD with the highest quartiles of tryptophan and IPA levels had multivariable-adjusted HRs of 0.62 (95% CI, 0.43-0.89) and 0.71 (95% CI, 0.50-0.99), respectively, for cardiovascular mortality and 0.67 (95% CI, 0.50-0.90) and 0.75 (95% CI, 0.57-0.99), respectively, for all-cause mortality compared with those in patients with CAD in the lowest quartile. After multivariable adjustments, 1-SD increases in the continuous plasma tryptophan and IPA levels were associated with 16% and 14% decreases, respectively, in the risks of cardiovascular mortality and with 13% and 14% decreases, respectively, in the risks of all-cause mortality. Restricted cubic splines displayed linear associations between plasma tryptophan and IPA levels and cardiovascular and all-cause mortality among patients with CAD. CONCLUSIONS: Our findings suggest that plasma tryptophan and IPA levels are significantly associated with decreased risks of cardiovascular and all-cause mortality in patients with CAD. Further studies are needed to determine the clinical diagnostic and therapeutic values of tryptophan and IPA levels on the risks of mortality among patients with CAD.


Assuntos
Doença da Artéria Coronariana , Animais , Humanos , Indóis , Propionatos , Estudos Prospectivos , Espectrometria de Massas em Tandem , Triptofano/metabolismo
16.
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue ; 34(5): 475-480, 2022 May.
Artigo em Chinês | MEDLINE | ID: mdl-35728847

RESUMO

OBJECTIVE: To explore the value of red blood cell distribution width (RDW) in evaluating the severity of patients infected with novel coronavirus Delta variant. METHODS: A total of 28 patients infected with novel coronavirus Delta variant in designated hospital treated by the First Affiliated Hospital of Xi'an Jiaotong University medical team from December 2021 to January 2022 were enrolled (23 cases of common type, 4 severe and 1 critical cases). The detailed clinical data of patients was collected. Then, Pearson's correlation analysis was used to identify the blood examination indexes which affected the arterial partial pressure of oxygen (PaO2) and arterial partial pressure of carbon dioxide (PaCO2). According to the median standard deviation of red blood cell distribution width (RDW-SD, 42.5 fL), 28 patients were divided into low RDW-SD group (≤ 42.5 fL, 16 cases) and high RDW-SD group (> 42.5 fL, 12 cases), and the immune related indexes of the two groups were compared. Receiver operator characteristic curve (ROC) was drawn to evaluate the predictive value of RDW-SD on the severity of illness of coronavirus disease 2019 (COVID-19). RESULTS: Correlation analysis showed that RDW-SD was the only index related to PaO2 and PaCO2 on the first day of admission, which was negative correlation with PaO2 (r = -0.379, P = 0.047) and positive correlation with PaCO2 (r = 0.509, P = 0.006). The results of effects of different clinical characteristics on RDW-SD level showed that there was no statistically significant difference in RDW-SD between groups with different clinical characteristics (including male/female, ≥ 65 years old/< 65 years old, having/without hypertension, having/without diabetes, smoking/not smoking, having/without hyperpyrexia, with/without fever for 3 days, with/without respiratory symptoms, with/without digestive symptoms). It was suggested that RDW-SD be relatively stable and not affected by the patient's baseline level. The percentage of B cells in low RDW-SD group was higher than that in high RDW-SD group (23.01±3.01 vs. 15.34±5.34, P < 0.05), immunoglobulin G (IgG) level in low RDW-SD group was lower than that in high RDW-SD group (g/L: 11.43±3.20 vs. 15.42±1.54, P < 0.05). The area under ROC curve (AUC) of RDW-SD in evaluating severe cases was 0.83 [95% confidence interval (95%CI) was 0.59-1.06], which was close to multilobularinltration, hypo-lymphocytosis, bacterial coinfection, smoking history, hyper-tension and age (MuL BSTA score; AUC = 0.82, 95%CI was 0.51-1.12) and better than British Thoracic Society's modified pneumonia score (CURB-65 score; AUC = 0.70, 95%CI was 0.50-0.91). CONCLUSIONS: RDW-SD has significant evaluative effect on the severity of COVID-19 patients with Delta variants.


Assuntos
COVID-19 , SARS-CoV-2 , Idoso , Eritrócitos , Feminino , Humanos , Masculino , Gravidade do Paciente , Prognóstico , Curva ROC , Estudos Retrospectivos
17.
Micromachines (Basel) ; 13(4)2022 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-35457818

RESUMO

AlN thin film is widely used in piezoelectric MEMS devices, and the accurate characterizations of its material coefficients are critical for the optimization of the AlN thin film process and the design of AlN thin-film-based devices. However, it is difficult to extract the material coefficients of AlN in the form of thin film. This paper reports a strategy for systematically extracting full elastic coefficients, piezoelectric coefficients and dielectric constants of c-axis-oriented AlN thin film based on the resonance method outlined in IEEE Standard on Piezoelectricity Std 176-1987. In this strategy, four self-suspended resonators with length thickness extension (LTE), thickness extension (TE), radial extension (RE), lateral electric field excited thickness shear (LEF-TS) modes together with a lamb wave resonator (LWR) are specifically adopted, and the material coefficients of AlN thin film are extracted by measuring the impedance spectra of these resonators. In addition, the effects of the pad and electrodes on the resonators were systematically studied, and the corresponding procedures to eliminate their influences on the extraction accuracy of material coefficients were proposed. Finally, a complete extraction process based on the above strategy was established. The simulation results show that the strategy can achieve high accuracy for AlN thin film with different thicknesses and electrode configurations, and it can also be applied to other materials belonging to the 6 mm piezoelectric crystal class such as ZnO, ScAlN, etc.

18.
Food Chem ; 381: 132220, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35114621

RESUMO

Effects of sodium ascorbate (1%, 2%, 3%) on the liquefaction of alkali-induced egg white gel (EWG) were investigated. Results showed hardness and water holding capacity (WHC) gradually decreased at 1%. However, hardness and WHC declined and then rose at 2% and 3%. Microstructural changes further confirmed the effects of sodium ascorbate on hardness and WHC. Electrophoresis showed sodium ascorbate caused the cross-linking between proteins, which was more resistant to degradation. Fourier transform infrared spectroscopy (FTIR) and surface hydrophobicity indicated sodium ascorbate significantly changed protein structure, especially at 2% and 3% resulted in protein reaggregation, increasing ß-sheet, and decreasing surface hydrophobicity in the later stage. In general, sodium ascorbate didn't inhibit the liquefaction of alkali-induced EWG at 1%, but did effectively at 2% and 3%. Therefore, high concentrations of sodium ascorbate possess the potential to inhibit the "alkali injury liquefaction" of preserved egg whites without heavy metals.


Assuntos
Álcalis , Clara de Ovo , Álcalis/química , Ácido Ascórbico , Clara de Ovo/química , Géis/química , Interações Hidrofóbicas e Hidrofílicas
19.
Micromachines (Basel) ; 12(5)2021 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-34069925

RESUMO

In this paper, a novel method to achieve all-GaN integrated MIS-HEMTs in a Si-CMOS platform by self-terminated and self-alignment process is reported. Furthermore, a process of repairing interface defects by supercritical technology is proposed to suppress the threshold voltage shift of all GaN integrated MIS-HEMTs. The threshold voltage characteristics of all-GaN integrated MIS-HEMTs are simulated and analyzed. We found that supercritical NH3 fluid has the characteristics of both liquid NH3 and gaseous NH3 simultaneously, i.e., high penetration and high solubility, which penetrate the packaging of MIS-HEMTs. In addition, NH2- produced via the auto coupling ionization of NH3 has strong nucleophilic ability, and is able to fill nitrogen vacancies near the GaN surface created by high temperature process. The fabricated device delivers a threshold voltage of 2.67 V. After supercritical fluid treatment, the threshold voltage shift is reduced from 0.67 V to 0.13 V. Our demonstration of the supercritical technology to repair defects of wide-bandgap family of semiconductors may bring about great changes in the field of device fabrication.

20.
Micromachines (Basel) ; 12(3)2021 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-33800370

RESUMO

This paper presents a high-accuracy complementary metal oxide semiconductor (CMOS) driven ultrasonic ranging system based on air coupled aluminum nitride (AlN) based piezoelectric micromachined ultrasonic transducers (PMUTs) using time of flight (TOF). The mode shape and the time-frequency characteristics of PMUTs are simulated and analyzed. Two pieces of PMUTs with a frequency of 97 kHz and 96 kHz are applied. One is used to transmit and the other is used to receive ultrasonic waves. The Time to Digital Converter circuit (TDC), correlating the clock frequency with sound velocity, is utilized for range finding via TOF calculated from the system clock cycle. An application specific integrated circuit (ASIC) chip is designed and fabricated on a 0.18 µm CMOS process to acquire data from the PMUT. Compared to state of the art, the developed ranging system features a wide range and high accuracy, which allows to measure the range of 50 cm with an average error of 0.63 mm. AlN based PMUT is a promising candidate for an integrated portable ranging system.

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