666 research outputs found
Virtual optofluidic time-stretch quantitative phase imaging
No full textOptofluidic time-stretch quantitative phase imaging (OTS-QPI) is a potent tool for biomedical applications as it enables high-throughput QPI of numerous cells for large-scale single-cell analysis in a label-free manner. However, there are a few critical limitations that hinder OTS-QPI from being widely applied to diverse applications, such as its costly instrumentation and inherent phase-unwrapping errors. Here, to overcome the limitations, we present a QPI-free OTS-QPI method that generates "virtual" phase images from their corresponding bright-field images by using a deep neural network trained with numerous pairs of bright-field and phase images. Specifically, our trained generative adversarial network model generated virtual phase images with high similarity (structural similarity index >0.7) to their corresponding real phase images. This was also supported by our successful classification of various types of leukemia cells and white blood cells via their virtual phase images. The virtual OTS-QPI method is highly reliable and cost-effective and is therefore expected to enhance the applicability of OTS microscopy in diverse research areas, such as cancer biology, precision medicine, and green energy
sj-docx-1-acr-10.1177_02841851231199744 - Supplemental material for Machine learning models based on multi-parameter MRI radiomics for prediction of molecular glioblastoma: a new study based on the 2021 World Health Organization classification
No full textSupplemental material, sj-docx-1-acr-10.1177_02841851231199744 for Machine learning models based on multi-parameter MRI radiomics for prediction of molecular glioblastoma: a new study based on the 2021 World Health Organization classification by Xin Kong, Yu Mao, Yuqi Luo, Fengjun Xi, Yan Li and Jun Ma in Acta Radiologica</p
Structural basis of DNA recognition of the Campylobacter jejuni CosR regulator
No full textCampylobacter jejuni is a foodborne pathogen commonly found in the intestinal tracts of animals. This pathogen is a leading cause of gastroenteritis in humans. Besides its highly infectious nature, C. jejuni is increasingly resistant to a number of clinically administrated antibiotics. As a consequence, the Centers for Disease Control and Prevention has designated antibiotic-resistant Campylobacter as a serious antibiotic resistance threat in the United States. The C. jejuni CosR regulator is essential to the viability of this bacterium and is responsible for regulating the expression of a number of oxidative stress defense enzymes. Importantly, it also modulates the expression of the CmeABC multidrug efflux system, the most predominant and clinically important system in C. jejuni that mediates resistance to multiple antimicrobials. Here, we report structures of apo-CosR and CosR bound with a 21 bp DNA sequence located at the cmeABC promotor region using both single-particle cryo-electron microscopy and X-ray crystallography. These structures allow us to propose a novel mechanism for CosR regulation that involves a long-distance conformational coupling and rearrangement of the secondary structural elements of the regulator to bind target DNA.This article is published as Zhang, Zhemin, Yuqi Yan, Jinji Pang, Lei Dai, Qijing Zhang, and Edward W. Yu. "Structural basis of DNA recognition of the Campylobacter jejuni CosR regulator." Mbio (2024): e03430-23. doi: https://doi.org/10.1128/mbio.03430-23. Copyright © 2024 Zhang et al. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license
Gender discrimination facilitates fMRI responses and connectivity to thermal pain
No full textMing Zhang, Yuqi Zhang, Yan Mu, Zhaoxing Wei, Yazhuo Kong
Data and codes supported the submission of NIMG-21-1109, NeuroImage
In this repository, we share the behavioral data, the processed fMRI data (i.e., activation maps, ROI, PPI), and the codes. Other materials that support the findings of this study also are available upon request
Tear Fluid Pharmacokinetics Following Oral Prednisone Administration in Dogs With and Without Conjunctivitis
No full textPurpose: To describe the pharmacokinetics (PK) of prednisone and prednisolone in tear fluid of dogs receiving oral prednisone at anti-inflammatory to immunosuppressive doses and to assess the impact of induced conjunctivitis on lacrimal drug levels.
Methods: Six healthy Beagle dogs were administered 4 courses of prednisone at 0.5, 1.0, 2.0, and 4.0 mg/kg given orally once a day for 5 days. At steady state, topical histamine was applied to induce mild (1 mg/mL) or severe (375 mg/mL) conjunctivitis in 1 eye of each dog and tear samples were collected from both eyes at selected times. Prednisone and prednisolone were quantified in tears by liquid chromatography-mass spectrometry.
Results: Lacrimal prednisone and prednisolone concentrations ranged from 2 to 523 ng/mL and 5 to 191 ng/mL, respectively. Drug concentrations were overall greater in dogs receiving higher doses of prednisone, but were not correlated with tear flow rate. Eyes with conjunctivitis often had larger amounts of prednisone and prednisolone in tear fluid compared to control eyes (up to +64%), but differences were not statistically significant. Significantly greater, but clinically insignificant, levels of prednisolone were found in eyes with severe versus mild conjunctivitis for oral prednisone doses ≥1.0 mg/kg.
Conclusions: Disruption of the blood–tear barrier with conjunctivitis did not significantly affect drug levels in tears. Based on drug PK in tears, oral prednisone is likely safe for the management of reflex uveitis and ocular surface diseases. However, further prospective trials using systemic corticotherapy in diseased animals are warranted to confirm findings from this preclinical study.This is a manuscript of an article published as Sebbag, Lionel, Yuqi Yan, Joe S. Smith, Rachel A. Allbaugh, Larry W. Wulf, and Jonathan P. Mochel. "Tear Fluid Pharmacokinetics Following Oral Prednisone Administration in Dogs With and Without Conjunctivitis." Journal of Ocular Pharmacology and Therapeutics (2019). DOI: 10.1089/jop.2019.0020. Posted with permission.</p
Near-field imaging of impedance grating surfaces
No full textThis dissertation investigates the inverse rough surface scattering problem in near-field optical imaging, the purpose of which is to reconstruct a scattering surface with a resolution beyond the diffraction limit. The surface is assumed to be a small and smooth deformation of a plane surface. Based on a transformed field expansion, the boundary value problem with complex scattering surface is converted into a successive sequence of a two-point boundary value problems in the frequency domain, whereby an analytic solution for the direct scattering problem is derived from the method of integrated solution. By neglecting the high order terms in the power series expansion, the nonlinear inverse problem is linearized and an explicit inversion formula is obtained. A spectral cut-off regularization is adopted to suppress the exponential growth of the noise in the evanescent wave components, which carry high spatial frequency of the scattering surface and contribute to the super resolution in the near-field regime. The method works for sound soft, sound hard, and impedance surfaces, and requires only a single illumination at a fixed frequency and is realized efficiently by the fast Fourier transform. Numerical results show that the method is simple, stable, and effective to reconstruct scattering surfaces with sub-wavelength resolution.Thesis (Ph. D.)--Michigan State University. Applied Mathematics, 2014Includes bibliographical reference
Research on the Development of Voice Assistants in the Era of Artificial Intelligence
No full textVoice assistants have gradually occupied an important position in the products of many electronics companies. Artificial Intelligence voice assistants are able to interpret human speech and respond. Users can ask their assistant questions and manage other essential tasks such as email calendars through verbal commands. This paper analyzes the artificial intelligence voice assistant through the method of comparative analysis. The author studies the development situation of intelligent voice assistants, and compares the differences between Chinese and foreign voice assistants, and finally discusses the relationship between voice intelligent assistants and people’s lives. The author found that users in different countries have different functional preferences for using voice assistants, but they can help people’s work and life to a great extent. In other words, voice assistants play an important role in contemporary society. Therefore, people need to better understand the relationship between humans and machin
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