Jiawei Tang - Academia.edu (original) (raw)

Papers by Jiawei Tang

Microbial Cell Factories

Background Acarbose, as an alpha-glucosidase inhibitor, is widely used clinically to treat type I... more Background Acarbose, as an alpha-glucosidase inhibitor, is widely used clinically to treat type II diabetes. In its industrial production, Actinoplanes sp. SE50/110 is used as the production strain. Lack of research on its regulatory mechanisms and unexplored gene targets are major obstacles to rational strain design. Here, transcriptome sequencing was applied to uncover more gene targets and rational genetic engineering was performed to increase acarbose production. Results In this study, with the help of transcriptome information, a TetR family regulator (TetR1) was identified and confirmed to have a positive effect on the synthesis of acarbose by promoting the expression of acbB and acbD. Some genes with low expression levels in the acarbose biosynthesis gene cluster were overexpressed and this resulted in a significant increase in acarbose yield. In addition, the regulation of metabolic pathways was performed to retain more glucose-1-phosphate for acarbose synthesis by weakening...

Bioorganic & Medicinal Chemistry

Proceedings of the 2022 International Conference on Management of Data

Data visualization is a powerful tool for understating information through visual cues. However, ... more Data visualization is a powerful tool for understating information through visual cues. However, allowing novices to create visualization artifacts for what they want to see is not easy, just as not everyone can write SQL queries. Arguably, the most natural way to specify what to visualize is through natural language or speech, similar to our daily search on Google or Apple Siri, leaving to the system the task of reasoning about what to visualize and how. In this demo, we present Sevi an end-to-end data visualization system that acts as a virtual assistant to allow novices to create visualizations through either natural language or speech. Sevi is powered by two main components: Speech2Text which is based on Google Cloud Speech-to-Text Rest API, and Text2VIS, which uses an end-to-end neural machine translation model called ncNet trained using a cross-domain benchmark called nvBench. Both ncNet and nvBench have been developed by us. We will walk the audience through two general domain datasets, one related to COVID-19 and the other on NBA player statistics, to highlight how Sevi enables novices to easily create data visualizations. Because nvBench contains Text2VIS training samples from 105 domains (e.g., sport, college, hospital, etc.), the audience can play with speech or text input with any of these domains.

Cornell University - arXiv, Dec 23, 2021

Figure 1: A brief history of natural language query to visualization in academia. After the relea... more Figure 1: A brief history of natural language query to visualization in academia. After the release of nvBench in 2021, some deep learning-based models are developed to support translating natural language queries into visualizations.

Cornell University - arXiv, Apr 30, 2020

Recent reopening policies in the US, following a period of social distancing measures, introduced... more Recent reopening policies in the US, following a period of social distancing measures, introduced a significant increase in daily COVID-19 infections, calling for a roll-back or substantial revisiting of these policies in many states. The situation is suggestive of difficulties modeling the impact of partial distancing/re-opening policies on future epidemic spread for purposes of choosing safe alternatives. More specifically, one needs to understand the impact of manipulating the availability of social interaction venues (e.g., schools, workplaces, and retail establishments) on virus spread. We introduce a model, inspired by social networks research, that answers the above question. Our model compartmentalizes interaction venues into categories we call mixing domains, enabling one to predict COVID-19 contagion trends in different geographic regions under different "what if" assumptions on partial reopening of individual domains. We apply our model to several highly impacted states showing (i) how accurately it predicts the extent of current resurgence (from available policy descriptions), and (ii) what alternatives might be more effective at mitigating the second wave. We further compare policies that rely on partial venue closure to policies that espouse widespread periodic testing instead (i.e., in lieu of social distancing). Our models predict that the benefits of (mandatory) testing outshadow the benefits of partial venue closure, suggesting that perhaps more efforts should be directed to such a mitigation strategy.

Lecture Notes in Electrical Engineering, 2017

Based on the analysis of the working principle and dynamic characteristics of quad-rotor, its dyn... more Based on the analysis of the working principle and dynamic characteristics of quad-rotor, its dynamic model is established. And the simulation platform of quad-rotor control system is developed in Matlab/Simulink environment. Considering the characteristics of nonlinear, strong coupling, under-actuated, and uncertain of the quad-rotor aircraft, the most widely used cascade PID controller is adopted in the simulation of the quad-rotor control system. To deal with the aircraft parameter uncertainties and external interferences, this paper designed a linear active disturbance rejection controller (LADRC), which realizes the real-time estimation and compensation of internal disturbances and external disturbances by using the extended state observer (ESO) to overcome the strong coupling, model uncertainties and external disturbances of the quad-rotor aircraft. Simulation results on attitude tracking and height control of the LADRC system are analyzed on the simulation platform and compared with the cascade PID control system. The simulation results show that the LADRC is superior to the cascade PID controller in terms of disturbance rejection.

Environmental Science: Water Research & Technology, 2021

Perfluorinated compounds (PFCs) are environmentally persistent, bioaccumulative, and globally dis... more Perfluorinated compounds (PFCs) are environmentally persistent, bioaccumulative, and globally distributed pollutants, which exhibit potential toxicity to both humans and ecosystems.

Background: Acute kidney injury (AKI) is a common clinical disease with complex pathophysiology a... more Background: Acute kidney injury (AKI) is a common clinical disease with complex pathophysiology and very limited therapeutic choices. This prompts the need for novel therapy targeting multiple aspects of this disease. Human amnion epithelial cells (hAECs) are ideal alternative stem cell source for regenerative medicine. Increasing evidence suggests that hAEC-derived exosomes (hAECs-EXO) may act as novel cellcell communicators. Accordingly, we assessed the therapeutic potential of hAECs in ischemia reperfusion mouse model of AKI and explored the underlying mechanisms. Methods: The hAECs were primary cultured and hAECs-EXO were isolated and characterized. An ischemic renal injury mouse model was established to mimic different severity of the kidney injury. Mouse blood creatinine level was used to assess renal function and kidney specimens were processed to detect cell proliferation, apoptosis and angiogenesis. Immune cells in ltration was analyzed by ow cytometry. hAECs-EXO was used to treat hypoxia-reoxygenation (H/R) injured HK2 cells and mouse bone marrowderived macrophages to evaluate their protective effect in vitro. Furthermore, hAEC exosomes were subjected to liquid chromatography-tandem mass spectrometry for proteomic pro ling. Results: We found that systematically administered hAECs could improve mortality and renal function in IRI mice; decrease the number of apoptotic cells; promote peritubular capillary regeneration and modulate kidney local immune response. However, hAECs showed very low kidney tissue integration. Exosomes isolated from hAECs recapitulated the renal protective effects of their parent cells. In vitro, hAECs-EXO protected HK-2 cells from H/R injury-induced apoptosis and promoted bone marrow-derived macrophage polarization toward M2 phenotype. Proteomic analysis on hAECs-EXO revealed proteins involved in extracellular matrix organization, growth factor signaling pathways, cytokine production and immunomodulation. These ndings demonstrated that paracrine of exosomes might be a key mechanism by hAECs mediating kidney functional recovery in AKI. Conclusions: We rst reported hAECs could improve mortality and renal repair in mice with ischemiareperfusion injury. The anti-apoptotic, pro-angiogenetic, and immunomodulatory capabilities of hAECs at least partially, through paracrine pathways. The renoprotective effects of hAECs-EXO might be a promising clinical therapeutic tool, overcoming the weaknesses and risks associated with the use of native stem cells for patients with AKI.

Additional file 3: Supplementary Figure 2. Proteomic profile of exosomes derived from hAECs. A an... more Additional file 3: Supplementary Figure 2. Proteomic profile of exosomes derived from hAECs. A and B, Gene ontology (GO) enrichment analysis for the significantly enriched GO terms of Cellular Component and Molecular Function. C, Bubble chart of the biological processes significantly enriched in hAECs exosome.

Additional file 2: Supplementary Figure 1. hAECs mouse organ distribution. A. 100 ng total DNA wa... more Additional file 2: Supplementary Figure 1. hAECs mouse organ distribution. A. 100 ng total DNA was used as template and human mitochondria specific sequence was amplified. PCR products was detected by 1% agarose gel electrophoresis. hAECs was mainly concentrated in the lung and heart, much less hAECs DNA was detected in the kidney. B. Human nuclear antigen (HNA) staining for hAECs in lung and kidney tissue at 1 h and 1 day after tail injection of 1 × 106 hAECs into the IRI mice. Green boxes indicate the HNA positive hAEC cells. Scale bar: 25 μm.

International Journal of Power Electronics, 2023

Scientific Reports, 2022

Aiming at the problem of poor transient performance of the control system caused by the control u... more Aiming at the problem of poor transient performance of the control system caused by the control uncertainty of the undertrained neural network, a neural network compensation control method based on fuzzy inference is proposed in this paper. The method includes three control substructures: fuzzy inference block, neural network control block and basic control block. The fuzzy inference block adaptively adjusts the neural network compensation control quantity according to the control error and the error rate of change, and adds a dynamic adjustment factor to ensure the control quality at the initial stage of network learning or at the moment of signal transition. The neural network control block is composed of an identifier and a controller with the same network structure. After the identifier learns the dynamic inverse model of the controlled object online, its training parameters are dynamically copied to the controller for real-time compensation control. The basic control block uses...

European Journal of Medicinal Chemistry, 2022

Osteoporosis is a common disease in which the risk of fracture increases due to decreased bone ma... more Osteoporosis is a common disease in which the risk of fracture increases due to decreased bone mass and qualitative skeletal changes. Selective androgen receptor modulators (SARMs) are agonists with tissue selectivity, which act as partial or weak androgen receptor (AR) agonists in androgenic tissues, but mainly as complete AR agonists in synthetic metabolic tissues. In the recent 20 years, many scaffolds of SARMs have been reported, among which several molecules are promising and are undergoing clinical trial evaluation. However, it is still a challenge to discover SARMs with high activity and reduced side effects. In this review, not only are structure of SARMs reported in the literatures systematically collected and classified but also the structure-activity relationships (SAR) are systematically summarized. Furthermore, the advances in SARMs as potential treatment for osteoporosis are also updated.

IOP Conference Series: Materials Science and Engineering, 2020

The magnetic resonance image (MRI) is widely used in medical treatment, which is harmless for hum... more The magnetic resonance image (MRI) is widely used in medical treatment, which is harmless for human body. However, more noise than the CT image sometimes can be a problem when doctor focus on details of some narrow structure of human body such as nasal. It is necessary to process the MRI like image fusion before using it. Subjects have to move head during a few MR scans. Image registration can help all corresponding points find their own correct position, so that it can be processed and give us more information from not only one time scan. Mutual information is a good mathematics tool in statistics and information theory. It can describe the relationship between input signal and output signal. In this paper, they are reference image data set and float image data set, and the process between them are some little bit head move and some other influence during scanning. The rigid body transformation is used to reduce the impact of head move because the nasal consisting of bones almost d...

Medical Physics, 2022

OBJECTIVES In this study, Ultrasound Needle-an improved minimally invasive ultrasonic horn device... more OBJECTIVES In this study, Ultrasound Needle-an improved minimally invasive ultrasonic horn device was used to explore its potential of synergizing with urokinase in enhancing clots lysis in an in-vitro intracranial hematoma model. MATERIALS AND METHODS 10 ml bovine blood was incubated for 3 h at 37 ℃, and coagulated into clot to mimic intracranial hematoma in-vitro. Ultrasound Needle was an improved ultrasonic horn with a fine tip (1.80 mm) and metallic sheath, and had a frequency of 29.62 kHz. 10000 IU urokinase was injected through the metallic sheath during the vibration of Ultrasound Needle tip to lyse the clots for 8 minutes under different working parameter settings (n = 8) to explore the influence of parameters Amplitude (%) and Duty (%) on clot lysis weight (W0 ). The maximum temperatures were measured by an infrared thermometer during the treatment process. The W0 of different treatment groups (US (Ultrasound Needle), US+NS (normal saline), UK (urokinase), US+UK, n = 8) were compared to verify the synergistic lysis effect of Ultrasound Needle combined with urokinase at optimal working parameters (40% Amplitude, 20% Duty; input power 4.20 W; axial tip-vibration amplitude 69.17 μm). Clots samples after treatment were fixed overnight for macroscopic examination. And fluorescent frozen sections and scanning electron microscopy examination were performed to show microscopic changes in clots and evaluate the cavitation effect of Ultrasound Needle on promoting drug diffusion within the clots. RESULTS The clot lysis weight W0 increased with the parameters Amplitude (%) and Duty (%), reached a peak (2.435±0.137 g) at 40% Amplitude and 20% Duty (input power 4.20 W), and then decreased. Higher Amplitude (%) and Duty (%) led to higher maximum temperature, and W0 was negatively correlated with the maximum temperature after the peak (r = -0.958). At the optimal parameter setting, the maximum temperature was 33.8±0.9 ℃, and the W0 of the US+UK group was more than 4 times of UK alone group (2.435±0.137 g vs 0.607±0.185 g). Fluorescent frozen sections confirmed that the ultrasound energy of Ultrasound Needle could mechanically damage the clot tissues and promote the intra-clots drug diffusion. Macroscopic examination showed that US+UK group caused larger clots lysis area than UK alone group (2.08 cm2 vs 0.65 cm2 ). In addition, electron microscopy examination exhibited that the fibrin filaments of the clots in US+UK group were lysed more thoroughly compared to single treatment groups. CONCLUSIONS Ultrasound Needle, an improved ultrasonic horn device, can mechanically damage the clot tissues and exhibit an excellent synergistic lysis effect with thrombolytic drugs. Therefore, Ultrasound Needle has great potential in providing a new minimally invasive strategy for rapid intracranial hematoma evacuation. This article is protected by copyright. All rights reserved.

Proceedings of the International Field Exploration and Development Conference 2018, 2019

Commonly, the strong heterogeneity leads to poorer sweep efficiency for poor reservoir. So, liqui... more Commonly, the strong heterogeneity leads to poorer sweep efficiency for poor reservoir. So, liquid production rate optimization was often used to improve development effect, especially liquid production rate increasing in high water cut stage. However, the quantitative relationship between the rising law of water cut and the main control factors is not clear, which results in the uncertainty of water cut changing after liquid increasing. This paper proposed a theoretical prediction model of water cut presenting the correlations between water cut and formation parameters, fluid property parameters, relative permeability parameters and production control conditions. Furthermore, the water cut rising law is theoretically divided into three types (continuous rising type, stable type and step type). Moreover, the theoretical equation of water cut change after liquid increasing is established, and the critical mathematical conditions were clarified for different kinds of water cut changing law such as water cut rising, unchanged or decreasing in complex multi-layer reservoirs. Then, oil rate increment and liquid rate changing can be predicted quantitatively further. The proposed method could be used for the working system optimization, stimulation optimization and development plan adjustment. It has been proved to have a high accuracy based on the actual dynamic data.

07.08.2018 Fluorinated structures make up more than 20 percent of modern drugs, but benign and fa... more 07.08.2018 Fluorinated structures make up more than 20 percent of modern drugs, but benign and fast fluorination schemes are scarce. In a study scientists have now combined dynamic kinetic resolution and nucleophilic fluorination for the asymmetric synthesis of florfenicol, a veterinary antibiotic. After enzymatic resolution of the racemate, two different fluorination strategies both proved effective and fast. One is especially interesting for industrial production.

Science of The Total Environment, 2021

In China, a large amount of kitchen waste (KW) is generated each year, and the resource utilisati... more In China, a large amount of kitchen waste (KW) is generated each year, and the resource utilisation of the KW has become a problem. KW has a high carbon content and can be used as a raw material for biochar. Kitchen waste biochar (KWB) can be used to prepare adsorption materials, soil amendments, energy materials, carbon quantum dots, and electrode materials. However, few studies have used KWB as a raw material for catalytic materials. The application of sulfur (S) and nitrogen (N) doped biochar in the field of catalysis has proved effective and feasible. KWB contained a certain mass percentage of N and S elements, which has good application potential for use in the field of catalysis by KWB. In the process of preparing KWB by KW, keeping S and N as much as possible and converting them into pyridine N and thiophene S benefit the application of catalysis. This review provides a reference for the future application of KWB in China.

ArXiv, 2020

Current social distancing measures to impede COVID-19 (such as shelter-in-place) are economically... more Current social distancing measures to impede COVID-19 (such as shelter-in-place) are economically unsustainable in the long term. Models are needed to understand the implications of possible relaxation options for these measures. We report such models, together with corresponding parameter estimation techniques and prediction outcomes, borrowing insights from another domain; namely, information cascades. Our models assume that the containment of the virus into isolated locales is no longer possible. Instead, we explore options that reduce the rate of spread. We predict COVID-19 contagion trends in different geographic regions under a "what if" scenario to understand the effects of potential policy decisions on regional trends. Our model allows experimentation with other policies that, we hope, can contribute to socially viable outcomes both in terms of health system capacity and economic impact. We apply our model to over 30 highly impacted states in the US and publish the...

IEEE Transactions on Visualization and Computer Graphics, 2021

Create a bar chart showing the top 5 states with the most confirmed cases until 2021-03-08 Show m... more Create a bar chart showing the top 5 states with the most confirmed cases until 2021-03-08 Show me the trend of confirmed, died, and recovered cases in Utah