25 research outputs found
Marine data collection based on embedded system with wired and wireless transmission
A great interest of boat manufacturers is to improve their products by knowing how the boats are used after sale. In order to gather information about the condition of usages, a system needs to be developed in order to collect data from different marine electronics mounted on the boat. Through this thesis work, we developed such data collecting system for leisure boats which support CAN Bus the message-based protocol. The data collection system has been developed and installed on a Linux-based embedded system connected to the CAN Bus network through a gateway in our laboratory. Through the data collection system, all data generated from different marine electronics in the network can be captured, filtered, transmitted, displayed and then stored in the system. For data transmission and access, we have implemented three methods through wired or wireless networks, i.e., the fixed Internet, 3G/LTE cellular networks and Wi-Fi networks.
Furthermore, the prototype implementation has been extensively tested in both lab and real-life environment
Re-Attention Transformer for Weakly Supervised Object Localization
Weakly supervised object localization is a challenging task which aims to
localize objects with coarse annotations such as image categories. Existing
deep network approaches are mainly based on class activation map, which focuses
on highlighting discriminative local region while ignoring the full object. In
addition, the emerging transformer-based techniques constantly put a lot of
emphasis on the backdrop that impedes the ability to identify complete objects.
To address these issues, we present a re-attention mechanism termed token
refinement transformer (TRT) that captures the object-level semantics to guide
the localization well. Specifically, TRT introduces a novel module named token
priority scoring module (TPSM) to suppress the effects of background noise
while focusing on the target object. Then, we incorporate the class activation
map as the semantically aware input to restrain the attention map to the target
object. Extensive experiments on two benchmarks showcase the superiority of our
proposed method against existing methods with image category annotations.
Source code is available in
\url{https://github.com/su-hui-zz/ReAttentionTransformer}.Comment: 11 pages, 5 figure
B7 family protein glycosylation: Promising novel targets in tumor treatment
Cancer immunotherapy, including the inhibition of immune checkpoints, improves the tumor immune microenvironment and is an effective tool for cancer therapy. More effective and alternative inhibitory targets are critical for successful immune checkpoint blockade therapy. The interaction of the immunomodulatory ligand B7 family with corresponding receptors induces or inhibits T cell responses by sending co-stimulatory and co-inhibitory signals respectively. Blocking the glycosylation of the B7 family members PD-L1, PD-L2, B7-H3, and B7-H4 inhibited the self-stability and receptor binding of these immune checkpoint proteins, leading to immunosuppression and rapid tumor progression. Therefore, regulation of glycosylation may be the “golden key” to relieve tumor immunosuppression. The exploration of a more precise glycosylation regulation mechanism and glycan structure of B7 family proteins is conducive to the discovery and clinical application of antibodies and small molecule inhibitors
Validation of the digital health literacy assessment among the university students in China
PurposeWith the development of the internet, digital health literacy (DHL) has become increasingly important for managing health. Consequently, various digital health literacy scales have been created for different groups. The purpose of this study was to verify the reliability and validity of the simplified Chinese version of the Digital Health Literacy Assessment (DHLA) scale among university students in China.MethodSnowball sampling was used to recruit the participants via an online platform (Wenjuan.com), and finally 304 university students were included in the survey. Demographic information and the status of DHL were collected through the online questionnaire. Cronbach’s alpha and split-half reliability were used to test the internal consistency of the scale, while the structural validity was verified by exploratory factor analysis and confirmatory factor analysis. Additionally, the convergence of the scale was tested by composite reliability (CR) and average variance extracted (AVE).ResultTwo dimensions were generated from 10 entries in the scale, named Self-rated Digital Health Literacy and Trust Degree of Online Health Information, respectively. The Cronbach’s alpha and split-half reliability of the total scale were 0.912 and 0.828, while the Cronbach’s alpha of the two dimensions were 0.913 and 0.830, respectively. The structural validity-related indexes of the scale met the standards (RMSEA = 0.079, GFI = 0.943, AGFI = 0.902, CFI = 0.971). In each dimension, the CR and AVE also reached critical values (CR > 0.7 and AVE > 0.5).ConclusionThe scale had high reliability and validity, indicating the simplified Chinese DHLA scale could be used to evaluate the DHL of university students in China
A Multifunctional and Fast-Response Lysosome-Targetable Fluorescent Probe for Monitoring pH and Isoxaflutole
A new chemosensor, namely N-(2-morpholinoethyl)acetamide-4-morpholine-1,8-naphthimide (MMN), was designed and synthesized through an amidation reaction. MMN was fabricated as a multifunctional fluorescent probe for monitoring pH and isoxaflutole. MMN exhibited excellent stability in MeCN/H2O (v/v, 9/1), with an obvious “off–on” fluorescence response toward pH changes due to intramolecular charge transfer (ICT), where the linear response ranges of MMN in the weakly acidic system were from 4.2 to 5.0 and from 5.0 to 6.0 with apparent pKa = 4.62 ± 0.02 and 5.43 ± 0.02. Based on morpholine as the lysosome targetable unit, MMN could selectively locate lysosomes in live cells. MMN also successfully detected the presence of H+ in test papers. Finally, MMN could specifically recognize isoxaflutole at a detection limit of 0.88 μM. A possible sensing mechanism was identified based on density function theory calculations. These results indicate that MMN could be a superior potential chemosensor for detecting pH and isoxaflutole selectively and sensitively and could be used in real sample detection
Strong and Stiff Aramid Nanofiber/Carbon Nanotube Nanocomposites
Small but strong carbon nanotubes (CNTs) are fillers of choice for composite reinforcement owing to their extraordinary modulus and strength. However, the mechanical properties of the nanocomposites are still much below those for mechanical parameters of individual nanotubes. The gap between the expectation and experimental results arises not only from imperfect dispersion and poor load transfer but also from the unavailability of strong polymers that can be effectively utilized within the composites of nanotubes. Aramid nanofibers (ANFs) with analogous morphological features to nanotubes represent a potential choice to complement nanotubes given their intrinsic high mechanical performance and the dispersible nature, which enables solvent-based processing methods. In this work, we showed that composite films made from ANFs and multiwalled CNTs (MWCNTs) by vacuum-assisted flocculation and vacuum-assisted layer-by-layer assembly exhibited high ultimate strength of up to 383 MPa and Young’s modulus (stiffness) of up to 35 GPa, which represent the highest values among all the reported random CNT nanocomposites. Detailed studies using different imaging and spectroscopic characterizations suggested that the multiple interfacial interactions between nanotubes and ANFs including hydrogen bonding and π–π stacking are likely the key parameters responsible for the observed mechanical improvement. Importantly, our studies further revealed the attractive thermomechanical characteristics of these nanocomposites with high thermal stability (up to 520 °C) and ultralow coefficients of thermal expansion (2–6 ppm·K<sup>–1</sup>). Our results indicated that ANFs are promising nanoscale building blocks for functional ultrastrong and stiff materials potentially extendable to nanocomposites based on other nanoscale fillers
SERS–Fluorescence Dual-Mode pH-Sensing Method Based on Janus Microparticles
A surface-enhanced
Raman scattering (SERS)–fluorescence dual-mode pH-sensing method
based on Janus microgels was developed, which combined the advantages
of high specificity offered by SERS and fast imaging afforded by fluorescence.
Dual-mode probes, pH-dependent 4-mercaptobenzoic acid, and carbon
dots were individually encapsulated in the independent hemispheres
of Janus microparticles fabricated via a centrifugal microfluidic
chip. On the basis of the obvious volumetric change of hydrogels in
different pHs, the Janus microparticles were successfully applied
for sensitive and reliable pH measurement from 1.0 to 8.0, and the
two hemispheres showed no obvious interference. The proposed method
addressed the limitation that sole use of the SERS-based pH sensing
usually failed in strong acidic media. The gastric juice pH and extracellular
pH change were measured separately in vitro using the Janus microparticles,
which confirmed the validity of microgels for pH sensing. The microparticles
exhibited good stability, reversibility, biocompatibility, and ideal
semipermeability for avoiding protein contamination, and they have
the potential to be implantable sensors to continuously monitor pH
in vivo
Hybrid Au/ZnO Hexagonal Pyramid Nanostructures: Preferred Growth on the Apexes of the Basal Plane than on the Tip
Nanoscale
materials having size- and shape-dependent interactions
with light provide flexible opportunities for harvesting solar energy.
Photocatalysts based on semiconductor nanoparticles (NPs) have been
the most effective materials for the conversion of light into chemical
energy, the efficiency of which can be further enhanced by the incorporation
of metallic NPs forming hybrid nanostructures. The structural parameters
of not only constituent components but also the resultant hybrid nanostructures
are critical for the optimization of photocatalytic performance of
composite catalysts. Here we demonstrated the successful size control
over ZnO hexagonal pyramids (HPs) for the first time. The smallest
HPs showing the best photocatalytic properties were used for further
Au attachment. Interestingly, we found that most of the Au NPs preferred
to grow on the apexes of the basal plane. Very occasionally, Au NPs
at the tip of ZnO HPs can be observed. The role of light in promoting
the reduction of gold salt by sodium citrate was also revealed. Quantum
mechanical calculations were used to explain the site-specific growth
of Au on the surface of ZnO HPs. Enhanced degradation rates over organic
dyes were found for Au/ZnO hybrids under both UV and visible light
irradiation
Four organic–inorganic compounds based on polyoxometalates: crystal structures and catalytic epoxidation of styrene
<div><p>Four compounds based on polyoxometalates, [Cu(4-bpo)(H<sub>2</sub>O)][Cu<sub>2</sub>(<i>μ</i><sub>2</sub>-Cl)(4-bpo)<sub>2</sub>(H<sub>2</sub>O)][SiW<sub>12</sub>O<sub>40</sub>][N(CH<sub>3</sub>)<sub>4</sub>]<sub>2</sub>·H<sub>2</sub>O (<b>1</b>), [Cu(4-bpo)]<sub>4</sub>[P<sub>2</sub>W<sub>18</sub>O<sub>62</sub>][N(CH<sub>3</sub>)<sub>4</sub>]<sub>2</sub>·6H<sub>2</sub>O (<b>2</b>), [Cu<sub>2</sub>(<i>μ</i><sub>2</sub>-OH)(4-bpo)<sub>2</sub>(Hina)(H<sub>2</sub>O)<sub>2</sub>]<sub>2</sub>[P<sub>2</sub>W<sub>18</sub>O<sub>62</sub>]·4H<sub>2</sub>O (<b>3</b>), and [Cu<sub>2</sub>(Hina)<sub>4</sub>(H<sub>2</sub>O)<sub>2</sub>][H<sub>2</sub>P<sub>2</sub>W<sub>18</sub>O<sub>62</sub>](Hina)·11H<sub>2</sub>O (<b>4</b>) (4-bpo=2,5-bis(4-pyridyl)-1,3,4-oxadiazole, ina=isonicotinic acid), have been hydrothermally synthesized and characterized by elemental analysis, IR, and single-crystal X-ray diffraction. The 3-D framework of <b>1</b> is composed by Keggin-type polyoxoanions {SiW<sub>12</sub>} and two types of infinite chains, {Cu(4-bpo)(H<sub>2</sub>O)}<sub><i>n</i></sub> and {Cu<sub>2</sub>(<i>μ</i><sub>2</sub>-Cl)(4-bpo)<sub>2</sub>(H<sub>2</sub>O)}<sub><i>n</i></sub>, through hydrogen bonds. Compound <b>2</b> has a 3-D rigid framework which is fabricated by Wells–Dawson type polyoxoanions {P<sub>2</sub>W<sub>18</sub>} and Cu-(4-bpo) chains through covalent bonds. Compound <b>3</b> contains an infinite {Cu<sub>2</sub>(<i>μ</i><sub>2</sub>-OH)(4-bpo)<sub>2</sub>(Hina)(H<sub>2</sub>O)<sub>2</sub>}<sub><i>n</i></sub> double-chain and {P<sub>2</sub>W<sub>18</sub>} polyoxoanions immobilized in the voids between the chains. Compound <b>4</b> exhibits a 3-D supramolecular network directed by hydrogen bonds between {P<sub>2</sub>W<sub>18</sub>} polyoxoanions and the double paddle-wheel {Cu<sub>2</sub>(Hina)<sub>4</sub>(H<sub>2</sub>O)<sub>2</sub>}. Compounds <b>1–4</b> were tested as heterogeneous catalysts for the epoxidation of styrene using <i>tert-</i>butyl hydroperoxide (TBHP) as oxidant. The compounds show catalytic activity with <b>2</b> giving the highest yield of styrene oxide.</p></div