Impact of the Deep neuromuscular Block on Oncologic Quality of laparoscopic Surgery in obese Gastric Cancer patients (DEBLOQS_GC) : A randomized clinical trial

AN LIANG Graduate School, Korea University 2021 국내박사

Objective: To evaluate whether deep neuromuscular block (NMB) improves oncologic quality of laparoscopic surgery in obese gastric cancer patients. Backgrounds: Obesity can impede oncological safety during laparoscopic cancer surgery. Numerous studies have reported that deep NMB improves laparoscopic surgical conditions, but it is unclear whether it has oncological benefits. Methods: We conducted a multi-institutional randomized controlled trial. Clinical stage I-II gastric cancer patients with body mass index (BMI) ≥25 kg/m2 were eligible and randomized 1:1 ratio to the deep or moderate NMB groups, with continuous infusion of rocuronium (0.5–1.0 and 0.1–0.5 mg/kg/h, respectively). The primary endpoint was the number of retrieved lymph nodes (LNs). The secondary endpoints included surgeon’s surgical rating score (SRS), interrupted events. Results: Between August 2017 to July 2020, 196 patients were enrolled from 9 institution. After 15 patients were excluded, 181 patients were analyzed as actual treatment group. There was no significant difference in the number of retrieved LNs between the deep (N=88) and moderate NMB groups (N=93) (44.6±17.5 vs. 41.5±16.9, P=0.239). However, deep NMB enabled the surgeon to retrieve more LNs in patients with BMI ≥28 kg/m2 than moderate NMB (49.2±18.6 vs. 39.2±13.3, P=0.026). Interrupted events during surgery were lower in the deep NMB group than in the moderate NMB group (21.6% vs. 36.6%; P=0.034). SRS were not influenced by the depth of NMB. Conclusions: Deep NMB provided oncological benefit by retrieving more LNs in patients with BMI ≥28 kg/m2 during laparoscopic gastrectomy and offered a stable surgical environment by reducing patient movements.

A numerical study of the contact behaviors in resistance spot welding steel-based sheets

Liang, Te-Hui The Ohio State University 2000 해외박사(DDOD)

This study has developed a numerical procedure for spot joining steel-based metal sheets, including uncoated mild steel sheets and hot-dipped galvanized steel sheets. This numerical procedure acts as a software signal processor, which can filter the material bulk resistance signals from the dynamic contact resistance (DCR) signals. Two immeasurable interfacial resistances at the electrode-to-sheet interface and the sheet-to-sheet interface can thus be numerically reconstructed step by step along the weld time. With the two computed interfacial resistances, the numerical model can produce the DCR curves similar to the measured DCR curve profiles. Two joule heat patterns, the peripheral joule heat and the uniform joule heat were found in this study. The competition between these two different energy patterns causes three distinct phases in the RSW process; that is, the non-laminar phase, the transition phase and the laminar phase. The non-laminar phase presents a peripheral joule heating process. A descriptive model of the non-laminar phase was developed to analytically explain the peripheral joule heat generation. The joule heat input during this phase presents a stable amount of energy varying within a small range. The energy gain or loss from an initial higher or lower static contact resistance in the squeeze time cannot influence the total joule heat. In the transition phase, the uniform heat generation competes with the peripheral heat to influence both temperature and electric potential distribution. The DCR curve in this phase is not sensitive to the actual interfacial resistance variation, especially for the beginning few weld cycles. The rising DCR curve in this phase occurs primarily because the globally elevated body temperature increases the material bulk resistances. The laminar phase presents a uniform temperature and electric potential distribution across the contact interfaces. The DCR measurement can consistently detect the resistance variation from the contact interfaces. Good numerical convergence behavior is found in this phase until the end of the weld time. The uncoated steel sheets and the hot-dipped galvanized steel sheets have long been known to have different weldability and DCR curve profiles. With the help of the numerical procedure, the computed sheet-to-sheet interfacial resistances of these two different types of contact also show different curve profiles to help explain the weldability. In general, the sheet-to-sheet interfacial resistance in joining the uncoated steel sheets presents a monotonic decreasing function and ends with a low resistance value. The sheet-to-sheet interfacial resistance in joining the hot-dipped galvanized steel sheets presents an unusual rising curve in the last few weld cycles. This late-rising sheet-to-sheet interfacial resistance with a relatively large electric current joining the hot-dipped galvanized steel sheets causes a higher weld nugget growth rate at the end of weld time. This result implies that one additional weld cycle in joining the hot-dipped galvanized steel sheets is more likely to cause expulsion than with the uncoated steel sheets. Furthermore, joining uncoated steel sheets presents an initial large sheet-to-sheet interfacial resistance and makes the weld nugget initiate earlier than with coated sheets. A longer duration of nugget formation implies that the uncoated steel sheets have a longer range of weld time to make a joint, and exhibit better weldability than the coated sheets. Furthermore, additional parametric studies were conducted in this research. With the efforts devoted in this research, an iteration procedure has been established to numerically study the contact behaviors in spot joining other contact metals.

Multiscale Study of Chemical Looping Technology and Its Applications for Low Carbon Energy Conversions

Zeng, Liang The Ohio State University 2012 해외박사(DDOD)

The chemical looping strategy for fossil energy applications promises to achieve an efficient energy conversion system for electricity, liquid fuels, hydrogen and/or chemicals generation, while economically separate CO₂ by looping reaction design in the process. Chemical looping particle performance, looping reactor engineering, and process design and applications are the key drivers to the success of chemical looping process development. In order to better understand and further scale up the chemical looping process, issues such as cost, time, measurement, safety, and other uncertainties need to be examined. To address these uncertainties, advanced reaction/reactor modeling and process simulation are highly desired and the modeling efforts can accelerate the chemical looping technology development, reduce the pilot-scale facility design time and operating campaigns, as well as reduce the cost and technical risks. The purpose of this work is thus to conduct multiscale modeling and simulations on the key aspects of chemical looping technology, including particle reaction kinetics, reactor design and operation, and process synthesis and optimization.

Comparative Meta-Analysis of Billroth 1 versus Billroth 2 versus Roux-en Y after Distal Gastrectomy for Stomach Cancer

AN LIANG 고려대학교 대학원 2017 국내석사

복강경 원 위부 위 절제술 (LDG)은 위암 치료에 있어 기존의 개방 원 위부 위 절제술 (ODG)의 기존상태를 대체했지만 LDG에서만 적용되는 재건 수술에 대한 정량적 검토는 아직 수행되지 않았다. 그 후 LDG 단독 환자의 데이터를 사용하여 복강경 기준으로 세 가지 재건 방법을 비교 하려고 했다. 메타 분석은 복강경 원 위부 위 절제술의 재건 방법을 비교 한 2016 년까지의 전자 서지 검색을 사용하여 수행되었다. 체계적인 검토 결과 및 민감도 분석의 11 가지 변수를 비교하여 통계력을 높이고 불일치 및 이질성을 최소화했다. 5767 명의 환자를 대상으로 한 23 건의 비 RCT 연구가 메타 분석에 포함되었다. 수술 시간을 제외하고 수술 후 회복 및 수술 변수에는 유의 한 차이가 없었다. B1은 B2 및 RY와 비교하여 유의하게 더 짧은 수술 시간을 나타났다. 수술 후 내시경 적 증상으로는 담즙 역류와 잔여 위염에서 B1과 B2보다 RY가 통계적으로 유의하게 우수 하였다. 수술 후 합병증의 측면에서, B1은 B2 및 RY보다 유의하게 낮은 이환률을 보였다. 우리의 연구는 LDG에서 문 합을 비교하는 최초의 메타 분석으로서 LDG에서 재건을 선택할 때 고려해야 할 새로운 기준이 생겼다. 수술 후 합병증 (B1 발생이 가장 적음)과 수술 후 내시경 증상 (RY가 가장 적게 발생)의 차이를 고려할 때 이 두 변수는 재건의 선택의 폭을 넓히는 데 합리적인 근거가 될 수 있다.

한·중 장소 접미사의 형태·의미론적 대조 연구

Fu, Liang 경북대학교 대학원 2018 국내석사

A Study on the Morphological and Semantic Contrast of Place Suffix in Korean and Chinese FU LIANG Department of Korean Language and Literature Graduate School, Kyungpook National University, Daegu, Korea (Supervised by Professor Paek, Doo-hyeon) (Abstract) This study aims to take the Korean Chinese place suffix and Chinese place quasi-suffix which have the same form as the research subject and contrast the characteristics of them. We try to find out the morphological and semantic similarities and differences that Korean Chinese place suffix and Chinese place quasi-suffix have. In addition, examine the corresponding features of Korean and Chinese place suffix for examining the corresponding aspect of Korean and Chinese place suffix derivatives. Chapter 2 reviews the characteristics of Korean and Chinese affix roughly. Based on the results of previous studies, rearrange the setting criteria of Korean Chinese place suffix and Chinese place quasi-suffix and provide a list of Korean and Chinese place suffixes. Chapter 3 reviews the morphological features of Korean and Chinese place suffix and reveal their morphological similarities and differences. Depending on preceding root’s syllable number and species, we examine the number of vocabulary that have used Korean and Chinese place suffix statistically. Then we reviews the characteristics of the leading roots precede the Korean and Chinese place suffixes contrastively. Also, by looking at the internal structure of the suffixes in Korean and Chinese, we consider and contrast the coupling method of Korean and Chinese place suffixes. We investigate the total number of words derived from Korean and Chinese place suffixes and investigate the productivity of Korean and Chinese place suffixes. Chapter 4 examines the meaning and usage of Korean and Chinese place suffix based on the lexical meaning. We examine the semantic qualities of Korean and Chinese place suffixes by examining some examples of place’s suffix derivation in Korean and Chinese. After analyzing the semantic functions of the Chinese and Korean place suffixes, we identify the semantic similarities and differences between Korean and Chinese place suffixes through contrast analysis. Furthermore, we try to look at the correspondence relationship between Korean and Chinese place suffixes through the correspondence pattern of place’s suffix derivation in Korean and Chinese. In this paper, it is meaningful that the existing studies related to Korean and Chinese place suffixes have complemented the limits of the scope of the study subjects. However, in the discussion of this paper, the research was conducted based only on the preliminary data and could not deal with the use of the place suffix derivation in real life. In this paper, only the Korean and Chinese place suffixes with the same forms have been dealt with, but in the future, it should be complemented by studies on other place suffixes. By expanding the objects of place suffixes and using large-scale vocabulary resources such as corpus, more objective and systematic research will enable deep understanding of Korean and Chinese place suffixes.

Hierarchically constructed Nickel Cobalt Sulfide/ Ni Co-layered Double Hydroxide core-shell Nanoarrays grown in situ on Nickel foam for Supercapacitors

LI, Ang 한양대학교 대학원 2018 국내석사

Battery-type electrodes consisting of hierarchically constructed nickel cobalt sulfide (denoted as NCS) core were fabricated employing a hydrothermal method with electrodeposited nickel cobalt layered double hydroxide (denoted as NCOH) core-shell nanotube arrays (denoted as NTAs) grown in situ on Ni foam for use in supercapacitors. The X-ray diffraction analysis, scanning electron microscopy, and energy-dispersive X-ray spectroscopy were used to characterize the structures and morphologies of the electrode materials. The nickel cobalt sulfide nanotubes coated with nickel cobalt layered double hydroxide nanosheets by electrodeposition for 40 s showed the highest specific capacitance (2105 F g−1 at the current density of 2 A g−1) and excellent cycling stability (65.1% capacitance retention after 3000 cycles). Moreover, a battery-type device based on NCS@NCOH as the positive electrode and carbon nanotube (denoted as CNT) as the negative electrode, delivering a specific capacity of 29.89 F g-1 at 0.5 A g-1, was fabricated for practical applications. The results show that the composite electrode material prepared by electrodeposition has great potential for application in energy storage devices.

Enable Intelligence on Billion Devices with Deep Learning

Li, Ang ProQuest Dissertations & Theses Duke University 2022 해외박사(DDOD)

With the proliferation of edge computing and Internet of Things (IoT), billions of edge devices (e.g., smartphone, AR/VR headset, autonomous car, etc) are deployed in our daily life and constantly generating the gigantic amount of data at the network edge. Bringing deep learning to such huge volumes of data will boost many novel applications and services in edge ecosystem and fuel the continuous booming of artificial intelligence (AI). Driven by this motivation, there is an urgent need to push the AI frontier to the network edge in order to fully exploit big data residing on edge devices.However, empowering edge intelligence with AI, especially deep learning, is technically challenging, due to the several critical challenges including privacy, efficiency, and performance. Conventional wisdom requires edge devices to transmit the data to cloud datacenters for training and inference. But moving a huge amount of data is prohibited by cost, high transmission delay, and privacy leakage. The emerging federated learning (FL) is a promising distributed learning paradigm that enables massive devices to collaboratively learn a machine learning model (e.g., deep neural network) without explicitly sharing data, and hence the privacy concerns caused by data sharing in the centralized learning can be mitigated. But FL is facing some critical challenges that hinder its deployments to edge devices, such as communication cost and data heterogeneity.Once we obtain a learned machine learning model, the next step is to deploy the model for serving applications and services. One straightforward approach is to deploy the model on device to perform the inference locally. Unfortunately, on-device AI often suffers from poor performance because most AI applications requires high computational power, which is technically unaffordable for resource-constrained edge devices. Edge computing pushes the cloud services from the network core to the network edge, and hence bridging devices with edge servers can alleviate the computational cost of running AI models on device alone. However, such a collaborative deployment scheme will inevitably incur transmission delay and raise privacy concern due to data movement between devices and edge servers. For example, the device can send the features extracted from raw data (e.g., images) to the cloud where a pre-trained machine learning model is deployed, but these extracted features can still be exploited by attackers to recover raw data and to infer embedded private attributes (e.g., age, gender, etc.).In this dissertation, I start with presenting a privacy-respecting data crowdsourcing framework for deep learning to address the privacy issue in centralized training. Then, I shift the setting from the centralized one to the decentralized environment, where three novel FL frameworks are proposed to jointly improve communication and computation efficiency while handling the heterogeneous data across devices. In addition to improving the learning on large-scale edge devices, I also design an efficient edge-assisted photorealistic video style transfer system for mobile phones by leveraging the collaboration between smartphones and the edge server. Besides, in order to mitigate the privacy concern caused by the data movement in the collaborative system, an adversarial training framework is proposed to prevent the adversary from reconstructing the raw data and inferring private attributes.

Spectroscopic Probes of Cardiac Calcium Regulation and Therapeutic Design

Li, Ang ProQuest Dissertations & Theses University of Minn 2021 해외박사(DDOD)

Cardiac muscle contraction and relaxation is controlled by changes in intracellular Ca2+, indicating that Ca2+ transport is a fundamental regulator of proper muscle function in the heart. The primary cardiac Ca2+ transporter is the sarcoendoplasmic reticulum Ca-ATPase 2a (SERCA2a), a transmembrane protein pump embedded in the sarcoplasmic reticulum (SR). SERCA2a pumps cytosolic Ca2+ into the sarcoplasmic reticulum (SR) of cardiac myocytes, enabling muscle relaxation during diastole. Abnormally high cytosolic [Ca2+] is a central factor in heart failure, suggesting that augmentation of SERCA2a Ca2+ transport activity could be a promising therapeutic approach. SERCA2a is inhibited by the protein phospholamban (PLB), and a novel transmembrane peptide, dwarf open reading frame (DWORF), is proposed to enhance SR Ca2+ uptake and myocyte contractility by displacing PLB from binding to SERCA2a. However, establishing DWORF’s precise physiological role requires further investigation. The work presented in this thesis focuses on the mechanisms and structural basis of SERCA2a regulation and primary drug screening of SERCA2a. In the first study (Chapter 4), we developed cell-based FRET biosensor systems that can report on protein-protein interactions and structural changes in SERCA2a complexes with PLB and/or DWORF. To test the hypothesis that DWORF competes with PLB to occupy the SERCA2a binding site, we transiently transfected DWORF into a stable HEK cell line expressing SERCA2a labeled with a FRET donor and PLB labeled with a FRET acceptor. We observed a significant decrease in FRET efficiency, consistent with a decrease in the fraction of SERCA2a bound to PLB. Surprisingly, we also found that DWORF also activates SERCA’s enzymatic activity directly in the absence of PLB at sub saturating calcium levels. Using site-directed mutagenesis, we generated DWORF variants that do not activate SERCA, thus identifying residues P15 and W22 as necessary for functional SERCA2a-DWORF interactions. This work advances our mechanistic understanding of the regulation of SERCA2a by small transmembrane proteins and sets the stage for future therapeutic development in heart failure research. In the second study (Chapter 5), we have developed fluorescence resonance energy transfer (FRET) biosensors with red-shifted fluorescent proteins, yielding improved characteristics for time-resolved (lifetime) fluorescence measurements. In comparison to biosensors with green and red FRET pairs (GFP/RFP), fluorescent proteins that emit at longer wavelengths (orange and maroon, OFP/MFP) increased the FRET efficiency, dynamic range, and signal-to-background of high-throughput screening (HTS). This combination promises to revolutionize high-precision FRET measurements from living-cells for the discovery of urgently needed therapeutics.

A splitting approach for the parallel solution of linear system on GPU cards

Li, Ang The University of Wisconsin - Madison 2016 해외박사(DDOD)

Dense and sparse linear algebra are identified by Colella (2004) as two of the seven most important classes of numerical methods (the "seven dwarfs"). Although more than a decade has passed since the original seven dwarfs' specification, fast linear algebra continues to be as relevant as ever. Solving linear systems is ubiquitous in a variety of science and engineering applications from computational mechanics (fluids and structure) to computational nanoelectronics (quantum mechanical simulations) to financial mathematics (random walks and geometric Brownian motion). Many real-life applications give rise to very large sparse linear systems that can be reordered to produce either narrow banded systems or low-rank perturbations of narrow banded systems, with the systems being either dense or sparse within the band. GPU-accelerated computing is the use of a Graphics Processing Unit (GPU) in tandem with a CPU to accelerate scientific, engineering, consumer, and enterprise applications. In many science and engineering fields, GPU-accelerated computing has become ubiquitous and is playing an increasingly important role in Scientific Computing, owing to its capacity to deliver speed-ups that in some cases can be as high as one order of magnitude compared to the execution on traditional multi-core CPUs. Despite the importance and ubiquity of solving linear systems and the fact that GPU-accelerated computing is presently widely used, there exist few solutions that leverage GPU or hybrid GPU/CPU computing, for solving linear systems of equations. In this dissertation, we discuss an approach for solving dense or sparse banded linear systems Ax = b on a GPU card. The matrix A ∈ R NxN is possibly asymmetric and moderately large; i.e., 10,000 ≤ N ≤ 500,000. The split and parallelize (SaP) approach seeks to partition the matrix A into diagonal sub-blocks Ai , i = 1, . . . , P, which are independently factored in parallel. The solution may choose to consider or to ignore the matrices that couple the diagonal sub-blocks Ai . This approach, along with the Krylov subspace-based iterative method that it preconditions, are implemented in a solver called SaP::GPU, which is compared in terms of efficiency with three commonly used multi-core CPU sparse direct solvers (PARDISO, SuperLU, and MUMPS), and one GPU sparse solver (NVIDIA's cuSOLVER). SaP::GPU, which runs entirely on the GPU except for several stages involved in preliminary row-column permutations, is more robust than all other four solvers and compares well in terms of efficiency with the aforementioned direct solvers. In a comparison against LAPACK and Intel's MKL, SaP::GPU also fares well when used to solve dense banded systems that are close to being diagonally dominant. SaP::GPU is currently used in the Simulation-Based Engineering Lab to compute the time evolution (dynamics) of many-body systems, e.g., granular material flow. SaP::GPU has also been used in determining the dynamics of mechanical systems that contain compliant (flexible) bodies, an exercise that calls for implicit integration methods. The latter methods draw on a Newton step, which solves nonlinear systems by repeatedly solving linear systems Ax = b. SaP::GPU, which is open source and freely available, is released under a permissive BSD3 license.

Complex nanoscopic objects from well-defined polymers that contain functional units

Li, Ang Texas A&M University 2012 해외박사(DDOD)

The construction of nanoscale polymeric objects with complex, well-defined structures and regiochemical functionalities is of great importance, because it enables the fabrication of soft materials with tunable properties. Direct polymerization of macromonomers through covalent bond formation and self-assembly of block copolymers <italic>via</italic> non-covalent interactions are two typical strategies to afford nanoscopic structures. Molecular brush polymers are composed of densely-grafted side chains along a polymeric backbone. Due to the significant steric repulsion from the side chains, they tend to adopt bottle-brush like conformations, as opposed to linear polymers. “Grafting through” synthesis of molecular brush polymers can provide precise control over the dimensions and functionalities of brush polymers. Shell crosslinked knedel-like nanoparticles (SCKs) are constructed by assembling from amphiphilic block copolymers into micelles, followed by covalent shell crosslinking to further stabilize the nanoparticles and introduce additional functional moieties. SCKs are attractive nanocarriers because of their variable morphologies, compositions and functionalities, which allow for the development of platforms for therapeutic or diagnostic purposes. By utilizing the orthogonal reactivity of the norbornene group and methacrylate group, two distinctly different reactive well-defined linear polymers, and a facile, one-pot synthesis of well-defined molecular brush polymers were studied by selective, orthogonal controlled radical polymerizations (CRPs) and ring-opening metathesis polymerization (ROMP). The living and high efficient characteristics of “grafting-through” strategy were further investigated for the preparation of topology-controlled brush polymers with tunable dimensions of both backbone and side chain lengths. Apart from the fundamental investigation of molecular brush polymers, a series of poly(carboxybetaine) (PCB)- and poly(ethylene glycol) (PEG)-grafted degradable SCKs were developed to evaluate their <italic> in vivo</italic> pharmacokinetics and biodistributions, aiming to achieve novel therapeutic and diagnostic platforms that may surpass the performance of the conventional PEGylated analogs.