Publications by authors named "Ning Xiang"

82 Publications

Experimental study on treatment of heavy metal-contaminated soil by manganese-oxidizing bacteria.

Environ Sci Pollut Res Int 2021 Aug 23. Epub 2021 Aug 23.

College of Earth and Environmental Sciences, Lanzhou University, 222 Tianshui South Road, Lanzhou, 730000, China.

There are many studies on the treatment of heavy metals by manganese-oxidizing bacteria and the reaction is good; the problem of compound pollution of heavy metals in soil has been difficult to solve. In this study, the application of manganese-oxidizing bacteria in soil was studied. The tolerance of manganese-oxidizing strains (Pseudomonas taiwanensis) to environmental conditions and the treatment effect of heavy metals As, Pb, and Cd in aqueous solution were investigated, and the effect of iron-manganese ratio on the treatment effect was discussed. The results showed that the suitable pH conditions for the growth of P. taiwanensis were 5-9, and the salt tolerance was 6% (by sodium chloride). The tolerant concentrations for heavy metals As(V) and Mn(II) were 500 mg L and 120 mg L, respectively. The strains were enriched by nutrient broth medium. After the logarithmic phase, the bacterial suspension was mixed with ATCC#279 medium at a ratio of 1:10, and a certain amount (10 mg L) of Mn(II) was added. The results of As, Pb, and Cd removal in the composite polluted water phase were 22.09%, 30.75%, and 35.33%, respectively. The molar ratio of manganese and iron affected the removal efficiency of single arsenic, the highest efficiency is 68%, and the ratio of iron to manganese is 1:5. However, when the soil was treated by the same method, the results showed that not all metals were passivated, such as Cu. At the same time, for As, Pb, and Cd, the treatment effects in soil were worse than those in water, perhaps more consideration should be given to environmental conditions, such as soil moisture and temperature, when manganese-oxidizing bacteria are used to treat soil.
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http://dx.doi.org/10.1007/s11356-021-15475-0DOI Listing
August 2021

Expression and significance of inflammatory reactions mediated by the IL-33/ST2 signaling pathway in the serum of heart failure patients.

Am J Transl Res 2021 15;13(7):8247-8252. Epub 2021 Jul 15.

Guizhou Medical University Guiyang, Guizhou Province, China.

Objective: This research aimed to explore the clinical significance of inflammatory reactions mediated by the IL-33/ST2 signaling pathway in heart failure (HF) patients.

Methods: A total of 100 HF patients treated in the Department of Cardiology in our hospital were prospectively regarded as the observation group, and 100 healthy age and gender matched patients who were undergoing physical examination were considered as the control group. The levels of interleukin-33 (IL-33), ST2, tumor necrosis factor-α (TNF-α) and pro B-type natriuretic peptide (pro-BNP) in the peripheral blood of patients were detected. The potential correlation between IL-33 and ST2, TNF-α and pro-BNP was analyzed by Pearson.

Results: The levels of IL-33, IL-10, ST2 and pro-BNP in the peripheral blood of patients in the observation group were higher than those in the control group; and they increased with the rise of cardiac function grade (all P<0.05). In addition, IL-33 was positively correlated with TNF-α, ST2 and pro-BNP (r=0.863, 0.879, 0.945; all P<0.05). Multivariate Logistic analysis revealed that the increase of IL-33 and ST2 were independent risk factors of HF.

Conclusion: The IL-33 and ST2 levels in the peripheral serum of HF patients are correlated with TNF-α and BNP, the finding of which can assist in clinical diagnosis and treatment.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8340166PMC
July 2021

Preparation and characterization of soybean protein isolate/pectin-based phytosterol nanodispersions and their stability in simulated digestion.

Food Res Int 2021 05 26;143:110237. Epub 2021 Feb 26.

College of Food Science and Technology, Zhejiang University of Technology, Hangzhou 310014, Zhejiang, People's Republic of China; Key Laboratory of Food Macromolecular Resources Processing Technology Research (Zhejiang University of Technology), China National Light Industry, People's Republic of China. Electronic address:

In this study, stigmasterol was nanoencapsulated in soy protein isolate -pectin-based nanodispersions. Based on the particle size and zeta-potential, the optimal pectin/SPI ratio of stigmasterol nanodispersion was determined to be 1:10. At this ratio, nanodispersions was manufactured with an average particle size of 477 ± 33 nm, an encapsulation efficiency of 89.37%, and a loading amount of 17.87%. The physical properties and morphology of the nanodispersion were investigated. Fourier transform infrared spectroscopy and differential scanning calorimetry analysis revealed that stigmasterol was loaded in nanodispersions successfully. The pectin, which was used to stable nanodispersion, could restrict the release of stigmasterol in the simulated gastric fluid. This experiment indicated that the presence of pectin can improve the stability of the nanodispersion and can be used to achieve controlled release of bioactive compounds.
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http://dx.doi.org/10.1016/j.foodres.2021.110237DOI Listing
May 2021

Metamaterial-like aerogels for broadband vibration mitigation.

Soft Matter 2021 May;17(17):4496-4503

Department of Mechanical Engineering, The University of Texas at Dallas, Richardson, TX 75080, USA.

We report a mechanical metamaterial-like behavior as a function of the micro/nanostructure of otherwise chemically identical aliphatic polyurea aerogels. Transmissibility varies dramatically with frequency in these aerogels. Broadband vibration mitigation is provided at low frequencies (500-1000 Hz) through self-assembly of locally resonant metastructures wherein polyurea microspheres are embedded in a polyurea web-like network. A micromechanical constitutive model based on a discrete element method is established to explain the vibration mitigation mechanism. Simulations confirm the metamaterial-like behavior with a negative dynamic material stiffness for the micro-metastructured aerogels in a much wider frequency range than the majority of previously reported locally resonant metamaterials.
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http://dx.doi.org/10.1039/d1sm00074hDOI Listing
May 2021

A Three-Dimensional Printable Liquid Metal-Like Ag Nanoparticle Ink for Making a Super-Stretchable and Highly Cyclic Durable Strain Sensor.

ACS Appl Mater Interfaces 2021 Apr 12;13(15):18021-18032. Epub 2021 Apr 12.

School of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China.

Fabrication of metal nanoparticle (NP)-based strain sensors with both a broad working range and linearity range is still a significant challenge. Typically, homogeneous conductive percolation networks are indispensable for linear sensing performance, whereas inhomogeneous microstructures may inevitably arise under large strain due to the formation of defects in rigid NPs. In this study, a sandwich-structured strain sensor with an extraordinarily large stretchability (800%) yet self-healing property is fabricated by three-dimensional printing using a liquid metal-like Ag NP ink. The strain sensor shows an initial conductivity of 248 S cm, a good linearity in two strain ranges, and a long-term stability after undergoing 5000 cycles under a strain level of 100%. Such highly comprehensive sensing performance is attributed to the unique structure of the Ag NP ink, in which Ag NPs coalesce together after room-temperature sintering triggered by chlorides, and then, the sintered Ag aggregates tend to form continuous conductive networks through hydrogen bonds between polyacrylic acid and carboxymethylcellulose. Further, the free flow of Ag aggregates is the root cause that leads to the change of relative resistance as demonstrated by finite element simulation. This Ag NP-based strain sensor shows high potential for application in monitoring human knuckle motion.
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http://dx.doi.org/10.1021/acsami.1c02422DOI Listing
April 2021

Recent Advances in 3D Printing with Protein-Based Inks.

Prog Polym Sci 2021 Apr 16;115. Epub 2021 Feb 16.

Department of Biomedical Engineering, Tufts University, Medford, MA 02155, USA.

Three-dimensional (3D) printing is a transformative manufacturing strategy, allowing rapid prototyping, customization, and flexible manipulation of structure-property relationships. Proteins are particularly appealing to formulate inks for 3D printing as they serve as essential structural components of living systems, provide a support presence in and around cells and for tissue functions, and also provide the basis for many essential ex vivo secreted structures in nature. Protein-based inks are beneficial in vivo due to their mechanics, chemical and physical match to the specific tissue, and full degradability, while also to promoting implant-host integration and serving as an interface between technology and biology. Exploiting the biological, chemical, and physical features of protein-based inks can provide key opportunities to meet the needs of tissue engineering and regenerative medicine. Despite these benefits, protein-based inks impose nontrivial challenges to 3D printing such as concentration and rheological features and reconstitution of the structural hierarchy observed in nature that is a source of the robust mechanics and functions of these materials. This review introduces photo-crosslinking mechanisms and rheological principles that underpins a variety of 3D printing techniques. The review also highlights recent advances in the design, development, and biomedical utility of monolithic and composite inks from a range of proteins, including collagen, silk, fibrinogen, and others. One particular focus throughout the review is to introduce unique material characteristics of proteins, including amino acid sequences, molecular assembly, and secondary conformations, which are useful for designing printing inks and for controlling the printed structures. Future perspectives of 3D printing with protein-based inks are also provided to support the promising spectrum of biomedical research accessible to these materials.
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http://dx.doi.org/10.1016/j.progpolymsci.2021.101375DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7996313PMC
April 2021

Characterization of iron reducibility of soy protein amyloid fibrils and their applications in iron fortification.

Food Chem 2021 Aug 3;353:129420. Epub 2021 Mar 3.

College of Food Science and Technology, Zhejiang University of Technology, Zhejiang, Hangzhou 310014, PR China; Key Laboratory of Food Macromolecular Resources Processing Technology Research (Zhejiang University of Technology), China National Light Industry, China. Electronic address:

Iron deficiency is a common nutritional disorder worldwide. Iron fortification of food is an effective strategy to control iron deficiency anemia (IDA), however, traditional iron fortificants usually provoke undesirable organoleptic changes or have limited colloid stability. In this research, we investigated iron reducibility of soy protein amyloid fibrils made from soy protein isolates (SPI), soy β-conglycinin (7S) and soy glycinin (11S), and explored their applications in iron fortification. All three protein fibrils showed iron reducibility. The reducibility was utilized to generate fibril-iron nanoparticle composites. The iron reducibility was affected by fibril concentration, degree of fibrillation and reducing amino acid composition. We identified 11S had the most significant effect on reducing Fe (III) to more bioavailable Fe (II) state, whereas 7S showed the optimal result for generation of iron nanoparticle on fibrils in situ. The resulted fibril-iron nanoparticle hybrids showed high dispersibility in various liquid foods, without distinct color change.
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http://dx.doi.org/10.1016/j.foodchem.2021.129420DOI Listing
August 2021

Enhanced Antibacterial Activity of Hen Egg-White Lysozyme against and due to Protein Fibrillation.

Biomacromolecules 2021 02 19;22(2):890-897. Epub 2021 Jan 19.

College of Food Science and Technology, Zhejiang University of Technology, Zhejiang, Hangzhou 310014, P. R. China.

Antibacterial agents with broad-spectrum antibacterial properties have always been in large demand. Lysozyme, a common and inexpensive protein, is widely used in food safety and biomedical applications for antibacterial purposes. However, many pathogens are lysozyme-resistant or insensitive. In this research, we investigated the antibacterial activities and mechanism of oligomers and amyloid fibrils formed from hen egg-white lysozyme (HEWL) against and . The HEWL fibrils showed significantly enhanced antibacterial activity against both lysozyme-resistant and lysozyme-insensitive . The HEWL oligomers, on the other hand, did not show an obvious improvement in antibacterial activity compared to native HEWL. Our results indicated that the fibrillation of HEWL can significantly enhance antibacterial activity against both and . The natural and inexpensive HEWL amyloid fibrils can be potentially applied to antimicrobial food packaging, animal feed, antibiotic replacement, etc.
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http://dx.doi.org/10.1021/acs.biomac.0c01599DOI Listing
February 2021

Liquid-Exfoliated Mesostructured Collagen from the Bovine Achilles Tendon as Building Blocks of Collagen Membranes.

ACS Appl Mater Interfaces 2021 Jan 5;13(2):3186-3198. Epub 2021 Jan 5.

Department of Biomedical Engineering, Tufts University, Medford, Massachusetts 02155, United States.

Mesoscaled assemblies are organized in native collagen tissues to achieve remarkable and diverse performance and functions. In this work, a facile, low-cost, and controllable liquid exfoliation method was applied to directly extract these collagen mesostructures from bovine Achilles tendons using a sodium hydroxide (NaOH)/urea aqueous system with freeze-thaw cycles and sonication. A series of collagen fibrils with diameters of 26-230 nm were harvested using this process, and in situ observations under polarizing microscopy (POM) and using molecular dynamics simulations revealed the influence of the NaOH/urea system on the tendon collagen. FTIR and XRD results confirmed that these collagen fibrils preserved typical structural characteristics of type I collagen. These isolated collagen fibrils were then utilized as building blocks to fabricate free-standing collagen membranes, which exhibited good stability in solvents and outstanding mechanical properties and transparency, with potential for utility in optical and electronic sensors. Moreover, in vitro and vivo evaluations demonstrated that these new resulting collagen membranes had good cytocompatibility, biocompatibility, and degradability for potential applications in biomedicine. This work provides a new approach for collagen processing by liquid exfoliation with utility for the formation of robust collagen materials that consist of native collagen mesostructures as building blocks.
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http://dx.doi.org/10.1021/acsami.0c20330DOI Listing
January 2021

Plant-based and cell-based approaches to meat production.

Nat Commun 2020 12 8;11(1):6276. Epub 2020 Dec 8.

Department of Biomedical Engineering, Tufts University, 4 Colby St., Medford, 02155, Massachusetts, USA.

Advances in farming technology and intensification of animal agriculture increase the cost-efficiency and production volume of meat. Thus, in developed nations, meat is relatively inexpensive and accessible. While beneficial for consumer satisfaction, intensive meat production inflicts negative externalities on public health, the environment and animal welfare. In response, groups within academia and industry are working to improve the sensory characteristics of plant-based meat and pursuing nascent approaches through cellular agriculture methodology (i.e., cell-based meat). Here we detail the benefits and challenges of plant-based and cell-based meat alternatives with regard to production efficiency, product characteristics and impact categories.
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http://dx.doi.org/10.1038/s41467-020-20061-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7722853PMC
December 2020

Recent advances in improving stability of food emulsion by plant polysaccharides.

Food Res Int 2020 11 4;137:109376. Epub 2020 Jun 4.

School of Materials and Chemical Engineering, Ningbo University of Technology, Zhejiang, Ningbo 315211, PR China.

Emulsion is considered to be an excellent system for delivering nutraceuticals, but instability limits the application of the emulsion. Adding stabilizers is an effective method to improve the stability of the emulsion. Due to safety concerns, stabilizers from natural resources are attracting more and more attentions in food industry. Plant polysaccharides are natural biopolymers which are widely distributed in the cells of plants. Many plant polysaccharides have been shown good emulsifying and thickening effects, therefore, they are widely used as stabilizers in emulsions. The application of plant polysaccharides in improving emulsion stability was reviewed in this paper. Firstly, the factors affecting the stability of the emulsion were elaborated in detail. On this basis, the methods of improving the stability of the emulsion were discussed. Furthermore, the effects of the plant polysaccharide structures on emulsion stability were explained, such as the molecular weight of the polysaccharide, the hydrophobic group of the polysaccharide, and the protein content of the polysaccharide. Additionally, the application of several common plant polysaccharides and their derivatives in emulsions were introduced. It is hoped that this review can provide sufficient theoretical basis for application of plant polysaccharides in emulsions in the future.
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http://dx.doi.org/10.1016/j.foodres.2020.109376DOI Listing
November 2020

Generalization of Sabine's reverberation theory.

Authors:
Ning Xiang

J Acoust Soc Am 2020 09;148(3):R5

Graduate Program in Architectural Acoustics, Rensselaer Polytechnic Institute, 110 8th Street, Troy, New York 12180, USA.

The Reflections series takes a look back on historical articles from The Journal of the Acoustical Society of America that have had a significant impact on the science and practice of acoustics.
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http://dx.doi.org/10.1121/10.0001806DOI Listing
September 2020

Model-based Bayesian analysis in acoustics-A tutorial.

Authors:
Ning Xiang

J Acoust Soc Am 2020 Aug;148(2):1101

Graduate Program in Arcvhitectural Acoustics, Rensselaer Polytechnic Institute, Troy, New York 12180, USA.

Bayesian analysis has been increasingly applied in many acoustical applications. In these applications, prediction models are often involved to better understand the process under investigation by purposely learning from the experimental observations. When involving the model-based data analysis within a Bayesian framework, issues related to incorporating the experimental data and assigning probabilities into the inferential learning procedure need fundamental consideration. This paper introduces Bayesian probability theory on a tutorial level, including fundamental rules for manipulating the probabilities, and the principle of maximum entropy for assignment of necessary probabilities prior to the data analysis. This paper also employs a number of examples recently published in this journal to explain detailed steps on how to apply the model-based Bayesian inference to solving acoustical problems.
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http://dx.doi.org/10.1121/10.0001731DOI Listing
August 2020

Ginsenoside Rg2 attenuates myocardial fibrosis and improves cardiac function after myocardial infarction via AKT signaling pathway.

Biosci Biotechnol Biochem 2020 Nov 24;84(11):2199-2206. Epub 2020 Jul 24.

Department of Traditional Chinese Medicine, Affiliated Hospital of Guizhou Medical University , Guiyang, Guizhou Province, China.

With the popularization of percutaneous coronary intervention technology in clinical applications, the mortality rate of acute myocardial infarction has been significantly reduced. However, ventricular remodeling following myocardial infarction (MI) has attracted extensive attention for that it can cause malignant arrhythmia, heart failure, and even death. We aimed to investigate the effects of ginsenoside Rg2 on cardiac function and myocardial fibrosis after MI and its potential mechanism. The results demonstrated that ginsenoside Rg2 improved cardiac function and inhibited collagen deposition in mice after MI. In addition, ginsenoside Rg2 reduced the levels of fibrosis-associated genes Collagen I (Col 1), Collagen III (Col 3), and alpha-smooth muscle actin (α-SMA) by activating phosphorylated AKT in angiotensin II-induced cardiac fibroblasts. Taken together, ginsenoside Rg2 improves cardiac function and attenuates cardiac fibrosis via the AKT pathway, suggesting that ginsenoside Rg2 may be a promising drug for the prevention of ventricular remodeling after MI. MI: myocardial infarction; AMI: acute myocardial infarction; LAD: left anterior descending; ECM: extracellular matrix; Col 1: collagen I; Col 3: collagen III; α-SMA: alpha-smooth muscle actin; ROS: reactive oxygen species; SOD: superoxide dismutase; GSH: glutathione; HO-1: heme oxygenase-1; WST8: water-soluble tetrazolium salt 8.
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http://dx.doi.org/10.1080/09168451.2020.1793292DOI Listing
November 2020

A new insight into the promotional effect of nitrogen-doping in activated carbon for selective catalytic reduction of NO with NH.

Sci Total Environ 2020 Oct 12;740:140158. Epub 2020 Jun 12.

State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, PR China. Electronic address:

A series of N-doped carbons were prepared to investigate the effect of different N-containing groups on selective catalytic reduction (SCR) of NOx with NH. Combined the SCR activity with the results of porosity analysis and X-ray photoelectron spectroscopy, it's deduced that the pyridinic N (N-6) rather than the surface area or doped total N was mainly responsible for the promoted SCR activity. The electron paramagnetic resonance and O-temperature programmed desorption (O-TPD) experiments indicated that N-6 created numerous of oxygen vacancy. The NO+O-TPD and transient response of NH further demonstrated that the increased oxygen vacancy enhanced the absorbability and reactivity of NOx, therefore the SCR reaction was elevated by accelerating the reaction in the Langmuir-Hinshelwood (L-H) mechanism. Furthermore, the NH-TPD suggested that N-6 was conductive to the NH adsorption. In situ DRIFTs of NH adsorption and reaction illustrated that the increased NH mainly existed as NH species, which were quickly consumed by NO+O, further elevated the reaction between gaseous NO and adsorbed NH in the Eley-Rideal (E-R) mechanism. The N-6 groups doped in the activated carbons facilitated the L-H and E-R reactions and thus promoted the SCR activity.
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http://dx.doi.org/10.1016/j.scitotenv.2020.140158DOI Listing
October 2020

[Treatment of spine metastases by open decompression, microwave ablation combined with open vertebroplasty and pedicle screw rod system].

Zhongguo Gu Shang 2020 May;33(5):470-6

Department of Orthopaedics, Fuzhou Second Hospital Affiliated to Xiamen University, Fuzhou 350000, Fujian, China.

Objective: To evaluate the preliminary clinical effective of open decompression, microwave ablation combined with open vertebroplasty and pedicle screw rod system in the treatment of spine metastases.

Methods: The clinical data of 12 patients with spine metastases were retrospectively analyzed, they were treated with open decompression, microwave ablation combined with open vertebroplasty and pedicle screw rod system between January 2014 and January 2016. Six males and 6 females were included, aged from 30 to 75 years old with an average of 55.6 years. There were 5 cases with spine metastases from lung cancer, 2 from breast cancer, 2 from thyroid cancer, 2 from renal cancer and 1 from liver cancer. Sevencases were thoracic metastases and 5 cases were lumbar metastases. Tomita score were mainly arranging from 3 to 6 points. According to ASIA neurologic grading system, 3 patients were grade C, 1 was grade D, 8 were grade E. Preoperative VAS score was 8.3±0.4. VAS was used to evaluate the clinical effect at 1, 3, 6 months after operation and final follow-up.

Results: All operations were successful and the amount of blood loss during surgery was 500 to 2 050 ml (average of 850 ml), operation time was 3.5 to 5.5 h (average of 4.5 h). There was no nerve root injury during surgery. Cerebrospinal fluid leakage occurred in 3 cases after surgery, which were healed after conservative treatment. Superficial infection of the incision occurred in 2 cases, which were healed after dressing change. There was one case of pulmonary infection. No deep infection, lower limb thrombosis or other complications were found. All 12 patients were followed up for 9 -40 months with an average of 28.6 months. The clinical symptoms of all patients were significantly improved, and the motor function of the lower limbs was recovered to varying degrees. According to ASIA grade, 2 cases of grade C were improved to grade B;1 case of grade C did not recover significantly;1 case of grade D was improved to grade E. One patient died of primary liver cancer 10 months after surgery. Local tumor recurrence occurred in 1 patient during follow up period. The VAS scores were 2.7±0.6, 2.5±0.4, 2.6±0.5, and 2.5±0.5 at 1, 3, 6 months after surgery and at final follow-up, which were significantly improved compared with the score before surgery(<0.05).

Conclusion: Open decompression, microwave ablation combined with open vertebroplasty and pedicle screw rod system in the treatment of spine metastases show some effects, with less intraoperative blood loss, shorter operation time, significant postoperative pain relief, and low tumor recurrence rate.
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http://dx.doi.org/10.12200/j.issn.1003-0034.2020.05.016DOI Listing
May 2020

Acceleration of computer-generated hologram using wavefront-recording plane and look-up table in three-dimensional holographic display.

Opt Express 2020 Mar;28(7):9833-9841

In this paper, we propose a fast calculation method using look-up table and wavefront-recording plane. Wavefront-recording plane method consists of two steps: the first step is the calculation of a wavefront-recording plane which is placed between the object and the hologram. In the second step, we obtain the hologram by executing diffraction calculation from the wavefront-recording plane to the hologram plane. The first step of the previous wavefront-recording plane method is time consuming. In order to obtain further acceleration to the first step, we propose high compressed look-up table method based on wavefront-recording plane. We perform numerical simulations and optical experiments to verify the proposed method. Numerical simulation results show that the calculation time reduces dramatically in comparison with previous wavefront-recording plane method and the memory usage is very small. The optical experimental results are in accord with the numerical simulation results. It is expected that proposed method can greatly reduce the computational complexity and could be widely applied in the holographic field in the future.
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http://dx.doi.org/10.1364/OE.385388DOI Listing
March 2020

Model-based Bayesian direction of arrival analysis for sound sources using a spherical microphone array.

J Acoust Soc Am 2019 Dec;146(6):4936

Graduate Program in Architectural Acoustics, School of Architecure, Rensselaer Polytechnic Institute, Troy, New York 12180, USA.

In many room acoustics and noise control applications, it is often challenging to determine the directions of arrival (DoAs) of incoming sound sources. This work seeks to solve this problem reliably by beamforming, or spatially filtering, incoming sound data with a spherical microphone array via a probabilistic method. When estimating the DoA, the signal under consideration may contain one or multiple concurrent sound sources originating from different directions. This leads to a two-tiered challenge of first identifying the correct number of sources, followed by determining the directional information of each source. To this end, a probabilistic method of model-based Bayesian analysis is leveraged. This entails generating analytic models of the experimental data, individually defined by a specific number of sound sources and their locations in physical space, and evaluating each model to fit the measured data. Through this process, the number of sources is first estimated, and then the DoA information of those sources is extracted from the model that is the most concise to fit the experimental data. This paper will present the analytic models, the Bayesian formulation, and preliminary results to demonstrate the potential usefulness of this model-based Bayesian analysis for complex noise environments with potentially multiple concurrent sources.
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http://dx.doi.org/10.1121/1.5138126DOI Listing
December 2019

Room acoustic modeling and auralization at an indoor firing range.

J Acoust Soc Am 2019 11;146(5):3868

Graduate Program in Architectural Acoustics, Rensselaer Polytechnic Institute, Troy, New York 12180, USA.

Reverberation time measurements were conducted in the 21-lane indoor firing range at Wright Patterson Air Force Base. Long reverberation times resulted in poor speech transmission indices (STI) which required acoustical treatments within the range. After treatment, reverberation times were significantly reduced and STI was dramatically enhanced. Standard Sabine and Eyring models failed to accurately predict the reverberation times. A computer simulation of the range was developed to predict room acoustic conditions and auralize speech performance for perceptual evaluation in the range.
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http://dx.doi.org/10.1121/1.5132286DOI Listing
November 2019

Electrospinning of zein-ethyl cellulose hybrid nanofibers with improved water resistance for food preservation.

Int J Biol Macromol 2020 Jan 15;142:592-599. Epub 2019 Nov 15.

Institute of Food Science, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China.

Zein electrospun nanofibers have poor water resistance, which restricts its applications in food preservation. To improve the water resistance of nanofibers, zein/ethyl cellulose (EC) hybrid nanofibers were prepared at different ratios. Besides, we also encapsulated cinnamon essential oil (CEO) into electrospun fibers for Agaricus bisporus preservation. As the weight ratio of EC increased from 0% (ZE-10) to 100% (ZE-01), the viscosity of electrospinning solutions gradually increased from 80.33 ± 19.23 mPa·s to 756.78 ± 22.48 mPa·s, resulting in sufficient chain entanglement for the preparation of uniform fibers. The average diameters of ZE-01, ZE-12, ZE-11, ZE-21, and ZE-10 nanofibers were 326 ± 53 nm, 267 ± 31 nm, 237 ± 51 nm, 292 ± 45 nm, and 362 ± 70 nm, respectively. The hydrogen bonds between the hydroxyl groups of ethyl cellulose and the amino groups of zein decreased the amount of free hydrophilic group, thus improving water resistance of nanofibers. Food packaging potential was evaluated using Agaricus bisporus. The zein/EC nanofibers loaded CEO significantly decreased weight loss and maintained the firmness of the Agaricus bisporus, and improved the quality of the Agaricus bisporus during storage.
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http://dx.doi.org/10.1016/j.ijbiomac.2019.09.134DOI Listing
January 2020

Bayesian Inference for Acoustic Direction of Arrival Analysis Using Spherical Harmonics.

Entropy (Basel) 2019 Jun 10;21(6). Epub 2019 Jun 10.

Graduate Program in Architectural Acoustics, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.

This work applies two levels of inference within a Bayesian framework to accomplish estimation of the directions of arrivals (DoAs) of sound sources. The sensing modality is a spherical microphone array based on spherical harmonics beamforming. When estimating the DoA, the acoustic signals may potentially contain one or multiple simultaneous sources. Using two levels of Bayesian inference, this work begins by estimating the correct number of sources via the higher level of inference, Bayesian model selection. It is followed by estimating the directional information of each source via the lower level of inference, Bayesian parameter estimation. This work formulates signal models using spherical harmonic beamforming that encodes the prior information on the sensor arrays in the form of analytical models with an unknown number of sound sources, and their locations. Available information on differences between the model and the sound signals as well as prior information on directions of arrivals are incorporated based on the principle of the maximum entropy. Two and three simultaneous sound sources have been experimentally tested without prior information on the number of sources. Bayesian inference provides unambiguous estimation on correct numbers of sources followed by the DoA estimations for each individual sound sources. This paper presents the Bayesian formulation, and analysis results to demonstrate the potential usefulness of the model-based Bayesian inference for complex acoustic environments with potentially multiple simultaneous sources.
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http://dx.doi.org/10.3390/e21060579DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7515069PMC
June 2019

Artificial enveloping reverberation for binaural auralization using reciprocal maximum-length sequences.

J Acoust Soc Am 2019 04;145(4):2691

Acoustic Laboratory, School of Physics and Optoelectronics, South China University of Technology, Guangzhou, China.

Binaural auralization through proper room-acoustic simulation can produce a realistic listening experience as if the listener were sitting in a room with spatial perception, including enveloping reverberance. Based on analysis of experimentally measured binaural room-acoustic data, this paper discusses an approach to creating artificial but natural-sounding reverberation for binaural rendering that can be employed in simulating such an environment in an efficient way. Approaches to adjusting the spaciousness of enveloping reverberance within the context of artificially generated reverberation are investigated via hearing tests. This paper exploits the excellent pseudorandom properties of maximum-length sequences to generate deterministic and controllable decorrelations between binaural channels for artificial reverberation for room-acoustic simulations with high computational efficiency. To achieve natural-sounding enveloping reverberance in an enclosed space, and thereby an immersive environment, the shapes of both the reverberation energy decays and the spatial characteristics are found to be decisive. This paper discusses systematic hearing test results that support the mentioned finding.
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http://dx.doi.org/10.1121/1.5095863DOI Listing
April 2019

Introduction to the Special Issue on Room Acoustic Modeling and Auralization.

J Acoust Soc Am 2019 Apr;145(4):2597

Graduate Program in Architectural Acoustics, Rensselaer Polytechnic Institute, Troy, New York 12180, USA.

This Special Issue on Room Acoustic Modeling and Auralization contains nineteen research papers. A majority of the papers focus on various room acoustic simulation techniques, while the remaining ones concentrate on auralization of either simulation or measurement results. Using room acoustic simulation, the last paper in this issue presents a case study of the historic venue, Palais du Trocadero in Paris, France.
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http://dx.doi.org/10.1121/1.5099017DOI Listing
April 2019

Diffusion equation modeling for sound energy flow analysis in multi domain structures.

J Acoust Soc Am 2019 Apr;145(4):2703

Department of Mechanical Engineering, Middle East Technical University, Ankara, 06800, Turkey.

This study investigates reliable models and methods to be applied in sound field analysis of multi-domain structures. The case structures are two monuments, namely, Süleymaniye Mosque and Hagia Sophia in İstanbul. These are both multi-volume spaces with many smaller sub-volumes coupled to each other by coupling apertures in form of arches. A key concern of the study is to examine energy flow decays and understand the mechanism of multi-slope sound energy decays. The methodology involves diffusion equation model (DEM) application in a finite-element scheme for sound energy flow analysis. Energy flow decays, energy flow dips, and spatial flow vectors are examined for single versus multi-domain DEM solutions. It is concluded that specification of different domains with individual diffusion coefficients is a critical setting such that, if not assigned correctly, may mislead the results. The energy flow vector analysis has enabled us to comprehend the architectural features in relation to such energy flow decay dip occurrence. The computational efficiency of DEM is also discussed. The DEM application in this study has proved to be a powerful and practical method in room acoustics applications, specifically for multi-rate decay investigations.
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http://dx.doi.org/10.1121/1.5095877DOI Listing
April 2019

Sound diffraction prediction of a rectangular rigid plate using the physical theory of diffraction.

J Acoust Soc Am 2019 Apr;145(4):2677

Graduate Program in Architectural Acoustics, Rensselaer Polytechnic Institute, Troy, New York 12180, USA.

For the purpose of numerical efficiency in room acoustic modeling, the physical theory of diffraction (PTD) is applied to approximate solutions of a finite-sized, rigid rectangular plate. The application of the PTD enables sound diffraction contributions from the two edge pairs of the rigid plate to be predicted separately while ignoring the edge waves around the corners in far-field. This paper discusses numerical implementations of the theoretical predictions to show the efficiency of the application of the PTD in finite-sized objects. The numerical results implemented will also be compared with preliminary experimental results carried out using an acoustical goniometer.
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http://dx.doi.org/10.1121/1.5095872DOI Listing
April 2019

Bayesian acoustic analysis of multilayer porous media.

J Acoust Soc Am 2018 Dec;144(6):3582

Department of Mechanical Engineering, University of Sheffield, Sheffield, S1 3JD, United Kingdom.

In many acoustical applications, porous materials may be stratified or physically anisotropic along their depth direction. In order to better understand the sound absorbing mechanisms of these porous media, the depth-dependent anisotropy can be approximated as a multilayer combination of finite-thickness porous materials with each layer being considered as isotropic. The uniqueness of this work is that it applies Bayesian probabilistic inference to determine the number of constituent layers in a multilayer porous specimen and macroscopic properties of their pores. This is achieved through measurement of the acoustic surface impedance and subsequent transfer-matrix analysis based on a valid theoretical model for the acoustical properties of porous media. The number of layers considered in the transfer-matrix analysis is varied, and Bayesian model selection is applied to identify individual layers present in the porous specimen and infer the parameters of their microstructure. Nested sampling is employed in this process to solve the computationally intensive inversion problem.
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http://dx.doi.org/10.1121/1.5083835DOI Listing
December 2018

Experimental investigations on sound energy propagation in acoustically coupled volumes using a high-spatial resolution scanning system.

J Acoust Soc Am 2018 Jun;143(6):EL437

Institute of Technical Acoustics, RWTH Aachen University, Kopernikusstr. 5, 52074 Aachen, Germany

The aim of this work is to study the sound field distribution in an experimental scale-model of two coupled rooms. An automatic scanning mechanism moves a microphone in small grid steps to measure room impulse responses at each grid point. The measurements cover the entire two-dimensional area of the coupled rooms. Sound energy distributions can be analyzed in the form of animated visual displays, revealing sound propagation across the coupling aperture and inside each room. This paper describes the measurement results, and the analysis method, which offer deep insights into the temporal development of a sound field in coupled spaces.
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http://dx.doi.org/10.1121/1.5040886DOI Listing
June 2018

A model-based Bayesian framework for sound source enumeration and direction of arrival estimation using a coprime microphone array.

J Acoust Soc Am 2018 Jun;143(6):3934

Graduate Program in Architectural Acoustics School of Architecture, Rensselaer Polytechnic Institute, Troy, New York 12180, USA.

Coprime microphone arrays use sparse sensing to achieve greater degrees of freedom, while the coprimality of the microphone subarrays help resolve grating lobe ambiguities. The result is a narrow beam at frequencies higher than the spatial Nyquist limit allows, with residual side lobes arising from aliasing. These side lobes can be mitigated when observing broadband sources, as shown by Bush and Xiang [J. Acoust. Soc. Am. 138, 447-456 (2015)]. Peak positions may indicate directions of arrival in this case; however, one must first ask how many sources are present. In answering this question, this work employs a model describing scenes with potentially multiple concurrent sound sources. Bayesian inference is used to first select which model the data prefer from competing models before estimating model parameters, including the particular source locations. The model is a linear combination of Laplace distribution functions (one per sound source). The likelihood function is explored by a Markov Chain Monte Carlo method called nested sampling in order to evaluate Bayesian evidence for each model. These values increase monotonically with model complexity; however, diminished returns are penalized via an implementation of Occam's razor.
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http://dx.doi.org/10.1121/1.5042162DOI Listing
June 2018

Characterization of Interactions between Curcumin and Different Types of Lipid Bilayers by Molecular Dynamics Simulation.

J Phys Chem B 2018 03 20;122(8):2341-2354. Epub 2018 Feb 20.

Department of Agricultural and Biological Engineering, Purdue University , West Lafayette, Indiana 47907, United States.

Curcumin (CUR) is a natural food ingredient with known ability to target microbial cell membrane. In this study, the interactions of CUR with different types of model lipid bilayers (POPE, POPG, POPC, DOPC, and DPPE), mixtures of model lipid bilayers (POPE/POPG), and biological membrane mimics (Escherichia coli and yeast) were investigated by all-atom explicit solvent molecular dynamics (MD) simulation. CUR readily inserts into different types of model lipid bilayer systems in the liquid crystalline state, staying in the lipid tails region near the interface of lipid head and lipid tail. Parallel orientation to the membrane surface is found to be more probable than perpendicular for CUR, as indicated by the tilt angle distribution. This orientation preference is less significant as the fraction of POPE is increased in the system, likely due to the better water solvation of perpendicular orientation in the POPE bilayer. In E. coli and yeast bilayers, tilt angle distributions were similar to that for POPE/POPG mixed bilayer, with water hydration number around CUR for the former being higher. Insertion of CUR resulted in membrane thinning. The results from these simulations provide insights into the possible differences in membrane disrupting activity of CUR against different types of microorganisms.
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http://dx.doi.org/10.1021/acs.jpcb.7b10566DOI Listing
March 2018

Investigation of the interaction of amyloid β peptide (11-42) oligomers with a 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) membrane using molecular dynamics simulation.

Phys Chem Chem Phys 2018 Mar;20(10):6817-6829

Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, IN 47907, USA.

Some amyloid related proteins/peptides are involved in aggregation and pore formation in phospholipid membranes (cell membranes), which result in a variety of neurological disorders such as Alzheimer's disease, Parkinson's disease and Huntington disease. In this research, the mechanism of pore formation by β amyloid (Aβ) peptides was investigated using molecular dynamics simulation by simulating the interaction of the Aβ(11-42) peptide, with a lipid membrane and the potential of the mean force of interaction was evaluated. A 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) membrane system with different cholesterol concentrations was used to simulate the neural cell membrane. The results indicated that Aβ(11-42) peptide oligomers with peptide numbers larger than two were more likely to lead to lipid deformation and water channels, and the free energy of penetration into the membrane decreased with the increasing number of peptides. Increasing the concentration of cholesterol leads to a higher energy barrier for the penetration of peptide into the lipid bilayer thereby protecting the membrane. The results of this research have potential application in the prevention of pore formation by Aβ aggregates on the lipid membrane.
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http://dx.doi.org/10.1039/c7cp07148eDOI Listing
March 2018
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