Water hampers the formation of strong and durable bonds between adhesive polymers and solid surfaces, in turn hindering the development of adhesives for biomedical and marine applications. Inspired ...by mussel adhesion, a mussel foot protein homologue (mfp3S‐pep) is designed, whose primary sequence is designed to mimic the pI, polyampholyte, and hydrophobic characteristics of the native protein. Noticeably, native protein and synthetic peptide exhibit similar abilities to self‐coacervate at given pH and ionic strength. 3,4‐dihydroxy‐l‐phenylalanine (Dopa) proves necessary for irreversible peptide adsorption to both TiO2 (anatase) and hydroxyapatite (HAP) surfaces, as confirmed by quartz crystal microbalance measurements, with the coacervate showing superior adsorption. The adsorption of Dopa‐containing peptides is investigated by attenuated total reflection infrared spectroscopy, revealing initially bidentate coordinative bonds on TiO2, followed by H‐bonded and eventually long‐ranged electrostatic and Van der Waals interactions. On HAP, mfp3s‐pep‐3Dopa adsorption occurs predominantly via H‐bond and outersphere complexes of the catechol groups. Importantly, only the Dopa‐bearing compounds are able to remove interfacial water from the target surfaces, with the coacervate achieving the highest water displacement arising from its superior wetting properties. These findings provide an impetus for developing coacervated Dopa‐functionalized peptides/polymers adhesive formulations for a variety of applications on wet polar surfaces.
Water hampers the formation of strong and durable bonds between adhesive polymers and solid surfaces. Inspired by mussel adhesion, a mussel foot protein homologue (mfp3S‐pep) is designed and demonstrated to undergo self‐coacervation. The peptide coacervate containing Dopa adsorbs irreversibly on titanium and hydroxyapatite surfaces after removing interfacial water as measured by attenuated total reflection infrared spectroscopy.
Alzheimer’s disease (AD) is the most common neurodegenerative disorder, and its etiology and pathogenesis are not fully understood. Astragalus polysaccharide (APS) has many pharmacological ...activities, but there are few reports about its role in AD. Using the common AD model APP/PS1 mice, it was found that the expression of Keap1 (a negative regulatory factor of Nrf2), the protein level of cytoplasmic Nrf2 and the content of MDA were increased significantly, while the mRNA level of Nrf2, the expression of Nrf2 in nucleus and the contents of SOD and GSH-Px were decreased significantly. APS treatment significantly increased the expression of Nrf2 in the nucleus but decreased its expression in the cytoplasm, and restored the expression levels of Keap1, SOD, GSH-Px and MDA. When APP/PS1 mice were treated with APS and injected with Nrf2 siRNA, the down-regulation of Nrf2 expression significantly blocked the regulation of APS on oxidative stress. Continuing to test the physiological function of AD mice showed that the spatial learning and memory abilities of APP/PS1 mice were impaired, the apoptosis of brain cells and the content of β-amyloid (Aβ) were significantly increased. APS treatment significantly improved the cognitive ability of APP/PS1 mice, reduced apoptosis and the accumulation of Aβ, but the above effects of APS were blocked by Nrf2 siRNA injection. Therefore, APS can activate Nrf2 pathway to improve the physiological function of AD mice, which may have important clinical application value.
•APS activates Nrf2 pathway in AD mice.•APS activates Nrf2 pathway to regulate oxidative stress in AD mice.•APS activates Nrf2 pathway to improve apoptotic level and cognitive ability of AD mice.•APS activates Nrf2 pathway to reduce the accumulation of Aβ in AD mice.
CuZn antisite defects have been regarded as the efficiency limiting factor of kesterite solar cells because they cause band tailing and loss of open circuit voltage (VOC). To suppress CuZn antisite ...defects, Ag-alloyed (Ag,Cu)2ZnSn(S,Se)4 (ACZTSSe) kesterite has been proposed. Although efficiency enhancement is realized by a limited amount of Ag addition (Ag/(Ag + Cu) ≤ 20%), the antisite defects may not be completely eliminated by the small amount of Ag. Further enhancement by using a high Ag content (Ag/(Ag + Cu) ≥ 20%) has not been achieved yet. In this work, the effects of Ag on the phase stability, crystal structure, defect properties and device performance are investigated. Experimental results demonstrate that the optimized formation temperature of kesterite is reduced with increasing Ag content. We demonstrate that Ag2ZnSn(S,Se)4 is ordered kesterite and CuZn antisite defects are effectively eliminated as 35% of Cu is replaced by Ag in ACZTSSe. To further increase the efficiency of the high Ag-content kesterite, 1 at% Na addition to the precursor is critical to passivate the interface as well as grain boundaries and increase the carrier concentration. An efficiency of 10% for ACZTSSe solar cells is reported with Ag/(Ag + Cu) = 35% at a processing temperature as low as 470 °C through an environment-friendly chemical spray pyrolysis process using aqueous solution. This study demonstrates the feasibility of controlling antisite defects and band-gap engineering by a larger amount of Ag substitution in the kesterite system to solve the VOC deficit problem.
POEMS syndrome is a rare plasma cell dyscrasia. This study compared the responses to and survival of 347 POEMS syndrome patients given three first-line treatment regimens: autologous stem cell ...transplantation (ASCT, N = 165) and melphalan + dexamethasone (MDex, N = 79), or lenalidomide + dexamethasone (LDex, N = 103). After a median 45-month follow-up, overall hematologic complete remission (CR
) was 46.4%, vascular endothelial growth factor complete remission (CR
) was 55.1%, and neurological remission (R
) was 93.8%. CR
was better with ASCT (49.7%) than with MDex (37.7%, p = 0.001). CR
was better with ASCT (66.2%) than with MDex (38.5%, p = 0.001) or LDex (47.7%, p = 0.008). Differences in R
achieved by three regimens (91.5% vs. 100% vs. 93.8%, p = 0.234) were not significant. Overall 3-year progression-free survival (PFS) was 80.5% and overall 3-year overall survival (OS) was 90.8%. PFS was 87.6% with ASCT and 64.9% with LDex (p = 0.003). OS in the three regimens did not differ (p = 0.079). In medium-high risk patients, ASCT had better CR
and CR
than MDex, and better PFS than LDex. Therefore, although all three treatments had reasonable responses and survivals, patients with higher risk may benefit more from ASCT treatment.
A manta ray biomimetic glider is designed and studied with both laboratory experiments and numerical simulations with a new dynamic update method called the motion-based zonal mesh update method ...(MBZMU method) to reveal its hydrodynamic performance. Regarding the experimental study, an ejection gliding experiment is conducted for qualitative verification, and a hydrostatic free-fall experiment is conducted to quantitatively verify the reliability of the corresponding numerical simulation. Regarding the numerical simulation, to reduce the trend of nose-up movement and to obtain a long lasting and stable gliding motion, a series of cases with the center of mass offset forward by different distances and different initial angles of attack have been calculated. The results show that the glider will show the optimal gliding performance when the center of mass is 20mm in front of the center of geometry and the initial attack angle range lies between A0 = -5° to A0 = -2.5° at the same time. The optimal gliding distance can reach six times its body length under these circumstances. Furthermore, the stability of the glider is explained from the perspective of Blended-Wing-Body (BWB) configuration.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In this study, a new method of cryopreservation of lactic acid bacteria (LAB) using natural deep eutectic solvents (NADESs) was developed. Survival rates of LAB during 24-h short-term and 180-day ...long-term cryostorage at − 20 °C were investigated. The results revealed that survival of
Streptococcus thermophilus
(
S. thermophilus
) in NADESs after 24 h of cryostorage was superior to survival of two other tested LAB. Moreover, survival was higher at a ratio of NADESs to
S. thermophilus
of 1:1 (
v
/
v
) than observed using a 4:1 (
v
/
v
) ratio. Representative freezing characteristics of five NADESs were elucidated, including thermodynamic properties and hydrogen bonding interactions after addition of water. In order to identify the protective mechanism of NADESs on cell structure and vital metabolic enzymes of
S. thermophilus
during cryostorage, transmission electron microscopy (TEM) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) were employed and enzyme activities of both lactate dehydrogenase (LDH) and
β
-galactosidase were determined. Subsequently, NADES GlyP prepared from glycerol and L-proline was demonstrated to maintain cell membrane structural integrity and significantly (
p
< 0.05) maintain activities of both intracellular enzymes of
S. thermophilus
. Moreover, NADESs could efficiently penetrate
S. thermophilus
cells and intracellular
β
-galactosidase activity could be used to demonstrate NADESs effectiveness in maintaining
S. thermophilus
survival after long-term cryostorage. These results demonstrate that NADESs can be used as green cryoprotective chemical agents (CPAs) that can efficiently increase LAB viability during cryostorage. These results should have great value in the food production and probiotics industries.
The fundamental technology behind bitcoin, known as blockchain, has been studied and used in a variety of industries especially in finance. The security of blockchain is extremely important as it ...will affects the assets of the clients as well as it is the lifeline feature of the entire system that needs to be guaranteed. Currently, there is a lack of a methodical approach to guarantee the security and dependability of the private key during its whole life. Furthermore, there is no quick, easy, or secure way to create the encryption key. A biometric-based private key encryption and management framework (BPKEM) for blockchain is proposed not only to solve the private key lifecycle manag- ement problem, but also it maintains compatibility with existing blockchain systems. For the problem of private key encryption, a biometric-based stable key generation method is proposed. By using the relative invariance between facial and fingerprint feature points, this measure can convert feature points into stable and distinguishable descriptors, then using a reusable fuzzy extractor to create a stable key. The correct- ness and efficiency of the newly proposed biometric-based blockchain encryption tech- nique in this paper has been validated in the experiments.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
At present, the UAV (Unmanned Aerial Vehicle) has been widely used both in civilian and military fields. Most of the current object detection algorithms used to detect UAVs require more parameters, ...and it is difficult to achieve real-time performance. In order to solve this problem while ensuring a high accuracy rate, we further lighten the model and reduce the number of parameters of the model. This paper proposes an accurate and lightweight UAV detection model based on YOLOv4. To verify the effectiveness of this model, we made a UAV dataset, which contains four types of UAVs and 20,365 images. Through comparative experiments and optimization of existing deep learning and object detection algorithms, we found a lightweight model to achieve an efficient and accurate rapid detection of UAVs. First, from the comparison of the one-stage method and the two-stage method, it is concluded that the one-stage method has better real-time performance and considerable accuracy in detecting UAVs. Then, we further compared the one-stage methods. In particular, for YOLOv4, we replaced MobileNet with its backbone network, modified the feature extraction network, and replaced standard convolution with depth-wise separable convolution, which greatly reduced the parameters and realized 82 FPS and 93.52% mAP while ensuring high accuracy and taking into account the real-time performance.
Abstract
Based on independent shear measurements using the Dark Energy Camera Legacy Survey/DR8 imaging data, we measure the weak lensing signals around isolated central galaxies (ICGs) from Sloan ...Digital Sky Survey/DR7 at
z
∼ 0.1. The projected stellar mass density profiles of satellite galaxies are further deduced, using photometric sources from the Hyper Suprime-cam survey. The signals of ICGs + their extended stellar halos are taken from Wang et al. All measurements are compared with predictions by the IllustrisTNG300-1 simulation. We find, overall, a good agreement between observation and TNG300. In particular, a correction to the stellar mass of massive observed ICGs is applied based on the calibration of He et al., which brings a much better agreement with TNG300 predicted lensing signals at
log
10
M
*
/
M
⊙
>
11.1
. In real observation, red ICGs are hosted by more massive dark matter halos and have more satellites and more extended stellar halos than blue ICGs at fixed stellar mass. However, in TNG300 there are more satellites around blue ICGs at fixed stellar mass, and the outer stellar halos of red and blue ICGs are similar. The stellar halos of TNG galaxies are more extended compared with real observed galaxies, especially for blue ICGs with
log
10
M
*
/
M
⊙
>
10.8
. We find the same trend for TNG100 galaxies and for true halo central galaxies. The tensions between TNG and real galaxies indicate that satellite disruptions are stronger in TNG. In both TNG300 and observation, satellites approximately trace the underlying dark matter distribution beyond 0.1
R
200
, but the fraction of total stellar mass in TNG300 does not show the same radial distribution as real galaxies.
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