Publications by authors named "Liu Guojun"
We observed tunable characteristics of optical frequency combs (OFCs) generated from InGaAs/GaAs double quantum wells (DQWs) asymmetric waveguide two-section mode-locked lasers (TS-MLLs). This involves an asymmetric waveguide mode-locked semiconductor laser (AWML-SL) operating at a center wavelength of net modal gain of approximately 1.06 µm, which indicates a stable pulse shape, with the power-current(P-I) characteristic curve revealing a small difference between forward and reverse drive currents in the gain region.
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- Magnesium and its alloys are gaining interest in various industries due to their high strength, stiffness, and effective properties like electromagnetic shielding and damping.
- However, magnesium's tendency to oxidize easily results in a non-protective oxide layer (MgO), leading to rapid degradation in high-oxidation environments.
- This study explores how preheating magnesium-calcium alloys in an argon atmosphere can create a thicker, more protective oxide layer, significantly improving oxidation resistance, particularly in the Mg-3Ca alloy.
Highly Stretchable Composite Conductive Fibers (SCCFs) and Their Applications.
Polymers (Basel)
September 2024
Article Synopsis
- - Stretchable composite conductive fibers (SCCFs) are highly conductive and flexible, making them perfect for use in wearable electronics and bioelectronics due to their excellent properties like breathability and biocompatibility.
- - The review discusses the complexities involved in developing SCCFs, including material choices and manufacturing methods, while also explaining how these fibers conduct electricity and how to enhance their performance.
- - It highlights the various applications of SCCFs in wearable tech and aims to guide further research and innovation in this field to maximize their potential use in electronic devices.
Article Synopsis
- * Simulation tests were conducted to observe the effects of different fracturing fluids — including pure CO2 and CO2 mixed with brine — on the microstructure and mechanical properties of shale after short-term exposure.
- * Results revealed that the mechanical parameters such as strength and brittleness of shale significantly decrease after treatment with CO2 fluids, especially when brine is added, indicating important implications for optimizing shale gas extraction methods.
Study on 1550 nm Human Eye-Safe High-Power Tunnel Junction Quantum Well Laser.
Micromachines (Basel)
August 2024
Article Synopsis
- 1550 nm semiconductor lasers are safe for human eyes and are used in LIDAR, optical communication, and gas sensing applications.
- A new high-power laser design features three quantum well structures and uses photolithography and etching to create trenches that enhance performance by reducing extension current.
- The resulting laser device achieved a pulsed peak power of 31 W with good efficiency and specific divergence angles, making it suitable for fog-transparent imaging and fast-ranging radar systems.
Article Synopsis
- - Telesurgery has the potential to allow surgeons to operate at a distance, but the effects of network latency and bandwidth on surgical success were not fully understood prior to this study.
- - A new telesurgery system was tested over a distance of 3000 km for 108 animal operations, focusing on how variations in latency (170-320 ms) and bandwidth (15-20 Mbps to <1 Mbps) influenced surgical outcomes, workload, and surgeons' perception.
- - Results showed that despite low bandwidth and increased latency, all surgeries were successful. Latency was found to have a greater impact on performance than bandwidth, and adjusting image quality can help manage latency challenges in telesurgery.
Article Synopsis
- Researchers used a special imaging technique called two-photon optical imaging to study how cervical lymphatic vessels (cLVs) drain cerebrospinal fluid (CSF) in live mice, revealing that contraction of the vessel walls is the main driving force of this flow.* -
- They found that in older mice, the frequency of these contractions and the speed of fluid flow decreased, linked to lower levels of smooth muscle actin.* -
- By applying prostaglandin F to aged mice, the researchers were able to enhance muscle contraction and improve CSF drainage, suggesting that boosting cLV function could help clear waste from the brain in aging individuals.*
Article Synopsis
- GRT-X, a compound targeting mitochondrial translocator protein (TSPO) and Kv7.2/3 potassium channels, has been shown to aid recovery from cervical spine injuries, promoting axonal growth in dorsal root ganglion (DRG) neurons.
- When tested on DRG explants from wild-type and TSPO knockout mice, GRT-X significantly stimulated axonal growth, while targeting TSPO with agonist XBD173 had delayed effects and activators/inhibitors of Kv7 channels reduced growth.
- The compound GRT-X increased gene expression related to axonal growth and myelination in co-cultures, but its effects were lost in TSPO knockout cultures, suggesting other mechanisms involved that need further exploration
Article Synopsis
- Phosphonate and phosphate prodrugs are important for improving drug absorption, but their toxic metabolites pose risks that must be addressed.
- The study specifically looks at how certain metabolite compounds affect pancreatic cancer cells, glioblastoma cells, and mouse astrocytes, finding that 2-naphthol is particularly toxic to these cell types.
- A clear trend shows that normal cells are generally more vulnerable to the toxic effects of these prodrug metabolites compared to cancer cells, highlighting the need to consider this toxicity during drug development.
Article Synopsis
- Antimonene is a promising material known for its high carrier mobility, thermoelectric properties, and stability, making it valuable for applications in Q-switched lasers, laser protection, and spintronics.
- Researchers have successfully produced antimonene films on silicon and germanium/silicon substrates using electron beam evaporation, marking a new approach in its fabrication.
- Characterization techniques like Raman spectroscopy, X-ray diffraction, and scanning electron microscopy revealed that factors such as deposition rate and substrate type can significantly influence the structure and growth of antimonene.
Article Synopsis
- - Mono and polycyclic aromatic hydrocarbons (PAHs) are harmful pollutants in water systems, primarily stemming from human activities, making their detection and mitigation vital for ecosystems.
- - Electrochemistry is highlighted as a key technology for developing effective sensors for detecting these contaminants and improving water treatment methods, demonstrating promising performance through various materials.
- - The study reviews current research on sensor technologies and treatment strategies for PAHs, discusses their sources and risks, and identifies challenges and future directions for improving pollution removal methods.
In this paper, an intelligent blind guide system based on 2D LiDAR and RGB-D camera sensing is proposed, and the system is mounted on a smart cane. The intelligent guide system relies on 2D LiDAR, an RGB-D camera, IMU, GPS, Jetson nano B01, STM32, and other hardware. The main advantage of the intelligent guide system proposed by us is that the distance between the smart cane and obstacles can be measured by 2D LiDAR based on the cartographer algorithm, thus achieving simultaneous localization and mapping (SLAM).
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- Human umbilical cord blood (UCB) mononuclear cells show promise for treating ischemic stroke (IS), but the specific role of SSEA3 positive subpopulations was previously unexplored.
- In this study, researchers isolated SSEA3(+)UCB cells, which made up about 7.01% of UCB cells, and found that these cells exhibited distinctive markers and higher Oct3/4 expression.
- After injecting SSEA3(+)UCB cells into a rat model of ischemic stroke, the treated group showed better neurological recovery and less neuronal loss compared to the control group, suggesting that SSEA3 positive cells may be effective in IS therapy.
Histone chaperone FACT (facilitates chromatin transcription) is well known to promote chromatin recovery during transcription. However, the mechanism how FACT regulates genome-wide chromatin accessibility and transcription factor binding has not been fully elucidated. Through loss-of-function studies, we show here that FACT component Ssrp1 is required for DNA replication and DNA damage repair and is also essential for progression of cell phase transition and cell proliferation in mouse embryonic fibroblast cells.
View Article and Find Full Text PDF[Application Effect of Continuous Lumbar Cistern Fluid Drainage Combined With Decompressive Craniectomy in the Treatment of Severe Craniocerebral Injury].
Sichuan Da Xue Xue Bao Yi Xue Ban
September 2023
Article Synopsis
- The study aimed to analyze how combining continuous lumbar cistern fluid drainage with standard decompressive craniectomy affects recovery in patients with severe craniocerebral injury.
- A total of 87 patients were divided into two groups: one receiving only standard craniectomy (control group), and the other receiving both treatments (observation group).
- Results showed that the observation group had quicker recovery times, lower medication needs, fewer complications, and better overall prognosis compared to the control group, although mortality rates were similar between the two groups.
As one of the main types of structural variation in the human genome, copy number variation (CNV) plays an important role in the occurrence and development of human cancers. Next-generation sequencing (NGS) technology can provide base-level resolution, which provides favorable conditions for the accurate detection of CNVs. However, it is still a very challenging task to accurately detect CNVs from cancer samples with different purity and low sequencing coverage.
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- Traditional belief held that bloodstream infections (BSIs) were primarily caused by a single organism, but this study reveals mixed populations of genetically diverse strains of Candida glabrata in patients.
- Whole genome sequencing showed distinct genetic differences among these strains, impacting their susceptibility to antifungal treatments and their ability to evade the immune system.
- Findings indicate that the persistence and relapse of infections may be linked to a diversity of drug-resistant strains, highlighting the need for a population-based understanding of C. glabrata during BSIs.
Topology-Optimized Micromixer Design with Enhanced Reverse Flow to Increase Mixing Efficiency.
Micromachines (Basel)
August 2023
Article Synopsis
- A new serpentine mixing unit model, using topology optimization, is developed to improve reverse flow and enhance mixing in both horizontal and vertical directions.
- This model increases the chaotic advection phenomenon, leading to a higher mixing index and is applied to create a new micromixer design called TOD.
- Simulations conducted with Comsol Multiphysics show that TOD excels in mixing performance, achieving over 90% mixing index for Reynolds numbers greater than 5, making it a viable micromixer option.
Article Synopsis
- - Metabolic reprogramming, specifically lipid metabolism, is crucial in cancer development, with significant findings in thyroid and kidney cancers showing increased lipid metabolism.
- - While some cancers exhibit overall down-regulation of lipid processes, fatty acid synthesis and cholesterol production are up-regulated in several types, and lipophagy is activated in thyroid and kidney cancers.
- - A model based on lipid metabolic genes has been created to predict cancer prognosis, enhancing our understanding of lipid metabolism's role in various cancers.
Diagnostic Value of a Combined Serum α-Hydroxybutyrate Dehydrogenase, Carcinoembryonic Antigen and Glycoantigen 125 Test for Early-Stage Breast Cancer.
Breast Cancer (Dove Med Press)
August 2023
Article Synopsis
- - The study aimed to evaluate the effectiveness of measuring serum levels of α-hydroxybutyrate dehydrogenase (α-HBDH), carcinoembryonic antigen (CEA), and cancer antigen 125 (CA125) for diagnosing early-stage breast cancer (ESBC) compared to benign breast disease and healthy controls.
- - Results showed that patients with ESBC had significantly higher levels of these markers, and using a combined approach for detection improved the diagnostic rate notably, with a combined detection sensitivity of 54.5% and specificity of 91.2%.
- - The overall conclusion is that measuring α-HBDH, CEA, and CA125 together offers a more reliable diagnostic tool for early-stage breast cancer
Article Synopsis
- This study aimed to determine if the consistency of venous tumor thrombus (VTT) affects the prognosis of patients with renal cell carcinoma (RCC).
- Researchers analyzed data from 190 RCC patients with VTT and found that 76.3% had solid VTT while 23.7% had friable VTT, but there were no significant survival differences based on VTT consistency.
- The overall conclusion is that VTT consistency does not serve as a prognostic risk factor for overall survival or progression-free survival in RCC patients, indicating that other factors may be more relevant.
Article Synopsis
- Automated classification of lymph node metastasis (LNM) is crucial for diagnosing and predicting patient outcomes, but it's difficult due to the need to analyze tumor shape and spread in tissues.
- The article introduces a two-stage dMIL-Transformer framework that utilizes multiple instance learning to improve classification by focusing on tumor morphology and spatial distribution.
- The framework achieves better accuracy (1.79%-7.50% improvement over existing methods) through a double Max-Min MIL strategy for instance selection and a Transformer-based approach for integrating and analyzing the selected instances.
Article Synopsis
- The study investigates how nitrous oxide (NO) emissions interact with straw management and future climate conditions (elevated CO and temperature) in wheat ecosystems.
- Findings indicate that returning straw (via incorporation or mulching) significantly increases NO emissions, but also enhances soil carbon and nitrogen levels, as well as denitrifying genes.
- Return of straw is beneficial in mitigating climate change by reducing the net global warming potential (NGWP) and greenhouse gas intensity (GHGI), while simultaneously boosting grain yield and soil organic carbon sequestration.