Research on detecting structural damage at the earliest possible stage has been an interesting topic for decades. Among them, the vibration-based damage detection method as a global technique is ...especially pervasive. The present study reviewed the state-of-the-art on the framework of vibration-based damage identification in different levels including the prediction of the remaining useful life of structures and the decision making for proper actions. This framework consists of several major parts including the detection of damage occurrence using response-based methods, building reasonable structural models, selecting damage parameters and constructing objective functions with sensitivity analysis, adopting optimization techniques to solve the problem, predicting the remaining useful life of structures, and making decisions for the next actions. For each part, the commonly used methods were reviewed and the merits and drawbacks were summarized to give recommendations. This framework is aimed to guide the researchers and engineers to implement step by step the structure damage identification using vibration measurements. Finally, the future research work in this field is recommended.
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•Coumarin thiazoles with novel broad antimicrobial spectrum were developed.•Compound V-a exerted potent inhibition efficacy towards MRSA (MIC = 1 μg/mL).•Compound V-a showed low ...toxicity, no obvious resistance and good bioavailability.•Compound V-a could effectively damage the membrane and lead to the leakage of protein.•Derivative V-a could induce the generation of ROS.
A novel type of coumarin thiazoles as unique multi-targeting antimicrobial agents were developed through four steps including cyclization, nucleophilic substitution and condensation starting from commercial resorcine. Most of the prepared coumarin thiazoles displayed favorable inhibitory potency against the tested strains. Noticeably, methyl oxime V-a exerted potent inhibitory efficacy against methicillin-resistant Staphylococcus aureus (MRSA) at low concentration (1 μg/mL) and showed broad antimicrobial spectrum. Medicinal bioevaluations revealed that the active molecule V-a exhibited low toxicity toward mammalian cells, rapidly killing effect, good capability of eradicating MRSA biofilms and unobvious probability to engender drug resistance. Chemical biological methods were employed to investigate preliminary mechanism, which indicated that compound V-a was able to damage the integrity of membrane to trigger leakage of protein, insert into MRSA DNA to block its replication and induce the generation of reactive oxygen species (ROS) to inhibit bacterial growth. Computational study manifested that low HOMO-LUMO energy gap of molecule V-a was favorable to exert high antimicrobial activity.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Melatonin is a naturally occurring compound in plants. Here, we tested the effect of exogenous melatonin on rapeseed (Brassica napus L.) grown under salt stress. Application of 30 µmol L−1 melatonin ...alleviated salt-induced growth inhibition, and the shoot fresh weight, the shoot dry weight, the root fresh weight, and the root dry weight of seedlings treated with exogenous melatonin increased by 128.2, 142.9, 122.2, and 124.2%, respectively, compared to those under salt stress. In addition, several physiological parameters were evaluated. The activities of antioxidant enzymes including peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) were enhanced by 16.5, 19.3, and 14.2% compared to their activities in plants without exogenous melatonin application under salt stress, while the H2O2 content was decreased by 11.2% by exogenous melatonin. Furthermore, melatonin treatment promoted solute accumulation by increasing the contents of proline (26.8%), soluble sugars (15.1%) and proteins (58.8%). The results also suggested that higher concentrations (>50 µmol L−1) of melatonin could attenuate or even prevent the beneficial effects on seedling development. In conclusion, application of a low concentration of exogenous melatonin to rapeseed plants under salt stress can improve the H2O2-scavenging capacity by enhancing the activities of antioxidant enzymes such as POD, CAT and APX, and can also alleviate osmotic stress by promoting the accumulation of osmoregulatory substances such as soluble proteins, proline, and water soluble glucan. Ultimately, exogenous melatonin facilitates root development and improves the biomass of rapeseed seedlings grown under salt stress, thereby effectively alleviating the damage of salt stress in rapeseed seedlings.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Choroidal neovascularisation (CNV) that occurs as a result of age-related macular degeneration (AMD) causes severe vision loss among elderly patients. The relationship between diabetes and CNV ...remains controversial. However, oxidative stress plays a critical role in the pathogenesis of both AMD and diabetes. In the present study, we investigated the influence of diabetes on experimentally induced CNV and on the underlying molecular mechanisms of CNV. CNV was induced via photocoagulation in the ocular fundi of mice with streptozotocin-induced diabetes. The effect of diabetes on the severity of CNV was measured. An immunofluorescence technique was used to determine the levels of oxidative DNA damage by anti-8-hydroxy-2-deoxyguanosine (8-OHdG) antibody, the protein expression of phosphorylated signal transducer and activator of transcription 3 (p-STAT3) and vascular endothelial growth factor (VEGF), in mice with CNV. The production of reactive oxygen species (ROS) in retinal pigment epithelial (RPE) cells that had been cultured under high glucose was quantitated using the 2',7'-dichlorofluorescein diacetate (DCFH-DA) method. p-STAT3 expression was examined using Western blot analysis. RT-PCR and ELISA processes were used to detect VEGF expression. Hyperglycaemia exacerbated the development of CNV in mice. Oxidative stress levels and the expression of p-STAT3 and VEGF were highly elevated both in mice and in cultured RPE cells. Treatment with the antioxidant compound N-acetyl-cysteine (NAC) rescued the severity of CNV in diabetic mice. NAC also inhibited the overexpression of p-STAT3 and VEGF in CNV and in RPE cells. The JAK-2/STAT3 pathway inhibitor AG490 blocked VEGF expression but had no effect on the production of ROS in vitro. These results suggest that hyperglycaemia promotes the development of CNV by inducing oxidative stress, which in turn activates STAT3 signalling in RPE cells. Antioxidant supplementation helped attenuate the development of CNV. Thus, our results reveal a potential strategy for the treatment and prevention of diseases involving CNV.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The expression levels of microRNAs (miRNAs) including miR-21, have been reported to change in response to traumatic brain injury (TBI), suggesting that they may influence the pathophysiological ...process in brain injury. To analyze the potential effect of miR-21 on neurological function after TBI, we employed the fluid percussion injury rat model and manipulated the expression level of miR-21 in brain using intracerebroventricular infusion of miR-21 agomir or antagomir. We found that upregulation of miR-21 level in brain conferred a better neurological outcome after TBI by improving long-term neurological function, alleviating brain edema and decreasing lesion volume. To further investigate the mechanism underlying this protective effect, we evaluated the impact of miR-21 on apoptosis and angiogenesis in brain after TBI. We found that miR-21 inhibited apoptosis and promoted angiogenesis through regulating the expression of apoptosis- and angiogenesis-related molecules. In addition, the expression of PTEN, a miR-21 target gene, was inhibited and Akt signaling was activated in the procedure. Taken together, these data indicate that miR-21 could be a potential therapeutic target for interventions after TBI.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Wind barriers have attracted significant attention as an effective measure to ensure train safety under crosswinds. However, in past decades, the influence of structural parameters such as the height ...and ventilation ratio of wind barriers on the difference of the average pressure coefficient between the train windward and leeward surface (Δ
Cp
) has not been fully investigated. To determine the influence of the interaction among the three factors, namely the wind barrier height (
H
), ventilation ratio (
R
), and distance to the train (
D
), twenty five numerical simulation cases with different structural parameters were considered based on an orthogonal design. The shear stress transfer (SST)
k
-
ω
turbulent model was employed to calculate the wind pressure coefficients, and the calculation accuracy was validated by using wind tunnel experiments. The results indicated that with an increase in
R
, Δ
Cp
first decreased and then increased, and Δ
Cp
decreased while
D
increased. Moreover, with the increase in
H
, Δ
Cp
first increased and then decreased. Therefore, these three factors must be considered during the installation of wind barriers. Furthermore, according to a range analysis (judging the relative importance of the three factors intuitively), the three factors were ranked in the following order:
R>H>D.
Based on a variance analysis,
R
was found to be of high significance to Δ
Cp
, followed by
H
, which was significant, whereas
D
had relatively insignificant influence. Finally, the optimal values of
R
and
H
were determined to be 20% and 110 mm, respectively. And when
R
=40%,
H
=85 mm, the train was relatively unsafe under these such conditions. The findings of this study provide significant guidance for the structural design of wind barriers.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
8.
Production of Xb via Υ(5S,6S) radiative decays Wang, Xiao-Yun; Cai, Zu-Xin; Li, Gang ...
The European physical journal. C, Particles and fields,
1/3, Volume:
83, Issue:
3
Journal Article
Peer reviewed
Open access
We investigate the production of
X
b
in the process
Υ
(
5
S
,
6
S
)
→
γ
X
b
, where
X
b
is assumed to be a
B
B
¯
∗
molecular state. Two kinds of meson loops of
B
(
∗
)
B
¯
(
∗
)
and
B
1
′
B
¯
(
∗
)
...were considered. To explore the rescattering mechanism, we calculated the relevant branching ratios using the effective Lagrangian based on the heavy quark symmetry. The branching ratios for the
Υ
(
5
S
,
6
S
)
→
γ
X
b
were found to be at the orders of
10
-
7
∼
10
-
6
. Such sizeable branching ratios might be accessible at BelleII, which would provide important clues to the inner structures of the exotic state
X
b
.
Drought and salinity are the primary factors limiting wheat production worldwide. It has been shown that a rice stress-responsive transcription factor encoded by the rice NAC1 gene (SNAC1) plays an ...important role in drought stress tolerance. Therefore, we introduced the SNAC1 gene under the control of a maize ubiquitin promoter into an elite Chinese wheat variety Yangmai12. Plants expressing SNAC1 displayed significantly enhanced tolerance to drought and salinity in multiple generations, and contained higher levels of water and chlorophyll in their leaves, as compared to wild type. In addition, the fresh and dry weights of the roots of these plants were also increased, and the plants had increased sensitivities to abscisic acid (ABA), which inhibited root and shoot growth. Furthermore, quantitative real-time polymerase chain reactions revealed that the expressions of genes involved in abiotic stress/ABA signaling, such as wheat 1-phosphatidylinositol-3-phosphate-5-kinase, sucrose phosphate synthase, type 2C protein phosphatases and regulatory components of ABA receptor, were effectively regulated by the alien SNAC1 gene. These results indicated high and functional expression of the rice SNAC1 gene in wheat. And our study provided a promising approach to improve the tolerances of wheat cultivars to drought and salinity through genetic engineering.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
In this paper,acoustic emission（AE） and digital image correlation methods were applied to monitor interface cracking in thermal barrier coatings under compression.The interface failure process can be ...identifie via its AE features,including buckling,delamination incubation and spallation.According to the Fourier transformation of AE signals,there arefourdifferentfailuremodes：surfaceverticalcracks,opening and sliding interface cracks,and substrate deformation.The characteristic frequency of AE signals from surface vertical cracks is 0.21 MHz,whilst that of the two types of interface cracks are 0.43 and 0.29 MHz,respectively.The energy released of the two types of interface cracks are 0.43 and 0.29 MHz,respectively.Based on the energy released from cracking and the AE signals,a relationship is established between the interface crack length and AE parameters,which is in good agreement with experimental results.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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