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An analytical solution is presented to study a plane solitary wave propagating past a concentric segmented arc-shaped breakwater using the matched eigenfunction and separation of variable methods. The undetermined potential coefficients are obtained based on matching conditions. The numerical results of this study are found to agree well with previous calculation results. The major factors (including the number of arc-shaped breakwaters, opening angle, incident angle, and gap width) that affecting the hydrodynamic loads and diffracted wave surface are discussed. The results indicate that the shielding effect of a segmented two-arc breakwater with a small gap width is better than that of an unsegmented arc-shaped breakwater. However, the arrangement of the segmented arc impacts the sheltering effect. Numerical results provide a valuable reference for the hydrodynamic analyses and structural design of segmented arc-shaped breakwaters. [ABSTRACT FROM AUTHOR]

The three-dimensional (3D) structure of RNA usually plays an important role in the recognition with RNA-binding protein. Along with the discovering of RNAs, several RNA databases are developed to study the functions of RNA based on sequence, secondary structure, local 3D structural motif and global structure. Based on RNA function and structure, different RNAs are classified and stored in SCOR and DARTS, respectively. The classification of RNA structures is useful in RNA structure prediction and function annotation. However, the SCOR and DARTS are not updated any more. In this study, we present an RNA classification database RR3DD based on RNA fold with the global 3D structural similarity. The RR3DD includes 13,601 RNA chains from PDB and mmCIF format structures which are classified into 780 RNA folds. The RNA chains from PDB and mmCIF format structures are aligned and clustered into 675 and 220 RNA folds, respectively. By analysing the RNA structure in RR3DD, we find that there are 11 clusters with more than 50 members. These clusters include rRNAs, riboswitches, tRNAs and so on. By mapping RR3DD into Rfam, we found that some RNAs without annotation by Rfam can be annotated through structural alignment. For example, we analysed tRNAs and found that tRNA were successfully grouped in RR3DD for which Rfam did not classify them into one family. Finally, we provide a web interface of RR3DD offering functions of browsing RR3DD, annotating RNA 3D structure and finding templates for RNA homology modelling. [ABSTRACT FROM AUTHOR]

Purpose: To summarize the research status on the function and mechanism of circRNAs in regulating the occurrence of diabetic retinopathy (DR). Methods: We systematically searched PubMed, Embase.com, and ARVO Abstracts website and reviewed relevant studies. Results: Thousands of circRNAs were found to be aberrantly expressed in DR patients, animal models, or cell models. A few circRNAs, such as cPWWP2A, circDNMT3B, circHIPK3, circ_0005015, et al were demonstrated to play an important role in DR by regulating the angiogenesis, proliferation, apoptosis, and inflammatory response of various cells in the retina. Conclusion: CircRNAs are involved in the development of DR. CircRNAs can not only serve as DR biomarkers, but also become therapeutic targets for DR. The role of plenty of circRNAs in DR is yet to be discovered. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the associations of the estimated glomerular filtration rate (eGFR) with peripapillary choroidal thickness (pCT) and retinal nerve fiber layer (pRNFL) thickness in diabetic patients by using swept-source optical coherence tomography (SS-OCT). Methods: Ocular treatment-naïve patients with type 2 diabetes mellitus registered in the community health system in Guangzhou, China, were recruited to participate in this prospective cross-sectional study. The eGFR was determined using the Xiangya formula, and the renal function was categorized into non-chronic kidney disease (non-CKD), mild CKD, and moderate to severe CKD (MS-CKD) according to the guidelines. The pCT and pRNFL thicknesses at 12 o'clock were obtained using an SS-OCT by a circular scan with a diameter of 3.4 mm centering on the optic nerve head, and the data from only one eye in each patient were used. Results: This study included 1,408 diabetic patients, with a mean age of 64.4 ± 7.8 years. The average pCT decreased with renal function deterioration, with 126.0 ± 58.0 μm for non-CKD, 112.0 ± 51.2 μm for mild CKD and 71.0 ± 22.9 μm for MS-CKD, respectively (P <.001). The pCT was found to be significantly thinner in CKD patients in all quadrantes (P <.05 in all regions) with the exception of the inferior quadrant, and the average pCT was positively correlated with eGFR (β = 0.3, 95%CI = 0.0 to 0.6, P =.021) after adjusting for other factors. The pRNFL thickness in the nasal quadrant was significantly reduced in patients with CKD, and pRNFL thickness was positively correlated with eGFR (β = 0.1, 95%CI = 0.0–0.2, P =.009) after adjusting for other factors. Conclusion: Impaired renal function was associated with a reduction of pCT and pRNFL thickness in patients with type 2 diabetes. The measurement of pCT and pRNFL may provide additional information for predicting renal impairment. [ABSTRACT FROM AUTHOR]

Background: Arterial pressure volume index (API) and arterial velocity pulse index (AVI) contribute to the development of vascular damage and cardiovascular disease. However, the relationship between common API/AVI trajectories and cardiovascular outcomes in hypertensive patients with heart failure with preserved ejection fraction (HFpEF) is unknown. Methods: A total of 488 consecutive hypertensive patients with HFpEF who repeatedly underwent API/AVI measurements were prospectively examined. We then applied API/AVI measurements into actual clinical practice. Latent mixture modeling was performed to identify API/AVI trajectories. Hazards ratios (HRs) were measured using Cox proportional hazard models. Results: We identified four distinct API/AVI trajectory patterns: low (7.6%), moderate (43.8%), high (28.9%), and very high (19.7%). Compared with the low group, higher API trajectories were associated with increased risk of total cardiovascular events (high group, adjusted HR: 2.91, 95% confidence interval [CI]: 1.97–4.26; very high group, adjusted HR: 2.46, 95%CI: 1.18–3.79). Consistently, higher AVI trajectories were also associated with a higher risk of total cardiovascular events (high group, adjusted HR: 2.58, 95%CI: 1.23–5.47; very high group, adjusted HR: 3.12, 95%CI: 1.83–6.08), compared with the low trajectory group. Conclusion: High API/AVI trajectories are strong predictors of cardiovascular risk in hypertensive patients with HFpEF. Among these patients, measuring API/AVI may improve risk stratification and provide additional information to tailor treatment strategies. [ABSTRACT FROM AUTHOR]

Investigation on bioactive chemical constituents of safflower led to the isolation of 10 compounds from the aqueous extract, including a new alkaloid (1), a new glucopyranoside (2), and 8 known compounds (3-10). The structures of two new compounds were elucidated on the basis of extensive spectral analyses, including 1D, 2D-NMR and HRESIMS. Biological research on the isolates indicated that compounds 3, 4 and 9 remarkably inhibited tyrosinase with IC50 at 0.11, 0.20 and 0.11 mM, respectively, compared with the positive control arbutin (0.26 mM). To investigate the interaction between enzyme and isolated compounds, an in silico docking study was carried out. The research provided valuable experience for phytochemistry and biological investigation on safflower. [ABSTRACT FROM AUTHOR]

Objectives: This study was aimed to further explore whether estradiol (E2) had protective effects on intervertebral disc degeneration (IVDD) in a rat model. Material/methods: Forty, three-month-old female Sprague Dawley (SD) rats were randomly divided into four groups: Sham, Ovariectomy (OVX), E2 and ICI182780 (ICI). Sham group only underwent the resection of a bit fat; OVX group underwent bilateral ovariectomy; E2 group was treated with E2 based on OVX; ICI group was treated with E2 and pretreated ICI182780 (inhibitor of the estrogen receptor) based on OVX. Radiography, hematoxylin and eosin (HE) staining, immunohistochemistry (IHC), western blot and quantitative real-time PCR (qRT-PCR) were applied to detect the apoptosis characteristics of intervertebral disc cells. Results: Radiographs showed marked intervertebral disc narrowing and HE staining showed typical apoptosis characteristics of intervertebral disc cells in OVX, which were reversed by E2. Furthermore, the results of IHC, Western blot and qRT-PCR revealed that OVX-induced IVDD was protected by E2 through decreasing the expression of caspase-3 and intracellular matrix metalloproteinases (MMPs), including MMP-3 and MMP-13, while increasing the expression of collagen Type II. All of the detected effects of E2 were abolished after treatment with ICI182780. Conclusion: 17β-E2 inhibits IVDD by down-regulating MMP-3 and MMP-13 and up-regulating collagen Type II in a rat model. [ABSTRACT FROM AUTHOR]

The technology of heat-assisted magnetic recording (HAMR) has improved the storage density of hard disc drives. The PFPE molecules of lubricant layer adhered on the disc can transfer from the lubricant layer and form the lubricant bridge which can deteriorate the stability of read/write process. In this paper, the formation and breaking of lubricant bridge at the head–disc interface (HDI) affects HAMR stability and deserves to be investigated. Using molecular dynamic simulation, a full-atom model was built to evaluate the behaviour of the lubricant bridge. Moreover, the effects of lubricant temperature, heating-up time, disc rotation speed and bearing pressure on the HDI were studied. It has been found that the amount of transferring atoms sharply increased when the lubricant temperature was above 700 K. The loss rate of lubricant layer decreased gradually during the heating process and it took about 2.2 ns for the remaining lubricant to reach stability. Furthermore, transferring PFPE molecules can form the lubricant bridge. A shorter heating-up time makes the lubricant bridge thicker and more robust. And the duration of lubricant bridge is notably affected by heating-up time, rotation speed and bearing pressure. A shorter heating-up time leads to a longer duration of lubricant bridge, whereas a higher rotation speed and bearing pressure reduces the duration of lubricant bridge. [ABSTRACT FROM PUBLISHER]

Two new metabolites, diorcinolic acid (1) and β-d-glucopyranosyl aspergillusene A (8), together with six diphenylethers (2–7), a diketopiperazine (9), a chromone (10) and a xanthone (11) were isolated from the fungus Aspergillus sydowii derived from the marine sponge Stelletta sp. The planar structures and their relative configurations were elucidated by analysing 1D, 2D NMR and HRESIMS data. Compound 8 is the first glycoside of phenolic bisabolane sesquiterpenes. Compounds 1 and 8 exhibited mild cytotoxicity against KB (human nasopharyngeal carcinoma cells), HepG2 (human liver cancer cells) and HCT 116 (human colon cancer cells). All compounds were evaluated for antibacterial activity and their abilities to suppress LPS-induced nitric oxide (NO) production. Compounds 2 and 4–7 showed mild antibacterial activity against human pathogen Staphylococcus aureus and fish pathogens Streptococcus iniae and Vibrio ichthyoenteri, and compounds 4 and 7 weakly suppressed NO production. [ABSTRACT FROM AUTHOR]

Boronizing treatment was done to form a boride surface layer well bonded with cemented carbide substrate. Multilayer microcrystalline diamond (MCD) and nanocrystalline diamond (NCD) coatings were prepared on the boronizing cemented carbide substrate by hot filament chemical vapor deposition (HFCVD) method. The surface and the cross section micrograph, coating component, hardness and adhesion of the as-deposited diamond coatings were observed with a SEM, Raman spectroscopy, nanoindenter and a Rockwell hardness tester accordingly. The results show that the MCD coating consists of well-faceted grains and the hardness of the MCD coating is about 85GPa. The NCD coating has morphological features with grain sizes of several tens of nanometer. The hardness of the NCD coating is about 52GPa. The boron doping of cemented carbide substrate can improve the fracture strength of the diamond film to some extent, and the adhesion of multilayer NCD/MCD coating is better than that of monolayer MCD and monolayer NCD coating. [ABSTRACT FROM AUTHOR]

We report controllable assembly of silver nanoparticles (Ag NPs) for patterning of silver microstructures. The assembly is induced by femtosecond laser direct writing (FsLDW). A tightly focused femtosecond laser beam is capable of trapping and driving Ag NPs to form desired micropatterns with a high resolution of ∼190 nm. Taking advantage of the ‘direct writing’ feature, three microelectrodes have been integrated with a microfluidic chip; two silver-based microdevices including a microheater and a catalytic reactor have been fabricated inside a microfluidic channel for chip functionalization. The FsLDW-induced programmable assembly of Ag NPs may open up a new way to the designable patterning of silver microstructures toward flexible fabrication and integration of functional devices. [ABSTRACT FROM AUTHOR]