Cavitation erosion-corrosion (CE-C) behaviour of various copper alloys for ship propellers were investigated in sulphide-containing 3.5% NaCl solutions. Results indicate that the CE-C resistance ...remarkably decreases with increase in sulphide concentration for cast and friction stir processed nickel-aluminum bronzes. CE increases the current density by approximately two orders of magnitude and causes a positive potential shift when the sulphide concentration exceeds 50 ppm. The synergistic effect between CE and corrosion contributes greatly to CE-C degradation in sulphide solutions. However, the CE-C behaviour is insensitive to sulphide concentration for manganese-aluminum bronze and manganese brass. In all solutions, CE causes a positive potential shift and increases the current density by less than one order of magnitude. Mechanical attack dominates the CE-C damage.
•CE-C behaviours of various copper alloys were studied in seawater with sulphide.•The sulphide has different effects on CE behaviour of different copper alloys.•The effect of CE on the electrochemical behaviour was analysed.•The synergistic effect between corrosion and CE was discussed.
Purpose
It has been reported that proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors can significantly reduce lipoprotein(a) Lp(a), and the mechanism for Lp(a) reduction remains ...unclear. Recently an interesting clinical research with a small sample showed a positive correlation between plasma PCSK9 and Lp(a) levels in diabetes. Here we aimed to use a relatively large sample to investigate whether such an association exists in Han Chinese.
Methods
A total of 783 inpatients were consecutively enrolled and composed of 172 patients with type 2 diabetes mellitus (T2DM) and 611 non-T2DM subjects. Plasma PCSK9 level was measured by ELISA, and its association with Lp(a) was assayed by Spearman’s correlation and multiple regression. Clinical and biochemical parameters were determined in all subjects studied.
Results
No significant differences in PCSK9 and Lp(a) levels were found between T2DM and non-T2DM patients. PCSK9 level was not related to Lp(a) level either in T2DM or non-T2DM group in bivariate correlation and multiple linear regression analysis. Additionally, no association between the levels of PCSK9 and Lp(a) was found in well, poorly controlled T2DM patients or in T2DM patients with or without coronary artery disease (CAD). Besides, no difference was found among the PCSK9 values across tertiles of Lp(a) level.
Conclusion
We found no association of plasma PCSK9 levels with Lp(a) level in Han Chinese with or without T2DM, suggesting that Lp(a) reduction by PCSK9 inhibitors may not be achieved simply through PCSK9 pathway at least in Chinese.
Abstract
The spin–orbit coupling (SOC) lifts the band degeneracy that plays a vital role in the search for different topological states, such as topological insulators (TIs) and topological ...semimetals (TSMs). In TSMs, the SOC can partially gap a degenerate nodal line, leading to the formation of Dirac/Weyl semimetals (DSMs/WSMs). However, such SOC-induced gap structure along the nodal line in TSMs has not yet been systematically investigated experimentally. Here, we report a direct observation of such gap structure in a magnetic WSM Co
3
Sn
2
S
2
using high-resolution angle-resolved photoemission spectroscopy. Our results not only reveal the existence and importance of the strong SOC effect in the formation of the WSM phase in Co
3
Sn
2
S
2
, but also provide insights for the understanding of its exotic physical properties.
We report on the terahertz (THz) quantum cascade lasers in continuous-wave (CW) operation with an emitting frequency above 5 THz. Excellent performance with a smaller leakage current and higher ...population inversion efficiency is obtained by one-well bridged bound-to-continuum hybrid quantum design at 5 THz. By designing and fabricating a graded metallic sampled distributed feedback grating in the waveguide, the first single-mode THz quantum cascade laser at 5.13 THz in CW operation mode is achieved. The maximum single-mode optical power of
∼
48
mW
is achieved at 15 K with a side-mode suppression ratio above 24 dB. This will draw great interest in the spectroscopy applications above the 5 THz range for THz quantum cascade lasers.
Summary
To examine the semen quality of patients with uraemia and renal transplant recipients, 40 patients with uraemia and 40 renal transplant recipients were included. According to their interval ...of post‐transplantation, renal transplant recipients were subdivided into group A (22) ≤2 years and group B (18) >2 years. A total of 40 healthy men with normal fertility were included as the controls. Semen samples from all subjects were collected and analysed. The fertility index (FI) value was calculated. The FI value of the normal fertility men was 13.02 (14.26), that of the renal transplant recipient groups A and B were 5.53 (8.30) and 9.27 (22.49) respectively, while the FI of the patients with uraemia was 0.23 (0.76). Compared with the uraemia group, the FI values of renal transplant recipient group either group A or group B were significantly better (P < 0.01). However, compared with the normal control group, the FI values of renal transplant recipient group A were lower (P < 0.01), while there was no significant difference between group B and the control group (P > 0.05). In conclusion, the FI of renal transplant recipients was recovered close to the level of healthy men with normal fertility 2 years after transplantation.
In this work we demonstrate the use of the push-pull model system 4-(dimethylamino)benzonitrile (DMABN) as a convenient molecular probe to investigate the local solvation structure and dynamics by ...means of time-resolved infrared spectroscopy (TRIR). The photochemical features associated with this system provide several advantages due to the high charge separation between the ground and charge transfer states involving the characteristic nitrile bond, and an excited state lifetime that is long enough to observe the slow solvation dynamics in organic solvents and ionic liquids. The conversion from a locally excited state to an intramolecular charge transfer state (LE-ICT) in ionic liquids shows similar kinetic lifetimes in comparison to organic solvents. This similarity confirms that such conversion depends solely on the intramolecular reorganization of DMABN in the excited state, and not by the dynamics of solvation. In contrast, the relative shift of the
ν
(CN) vibration during the relaxation of the ICT state reveals two distinct lifetimes that are sensitive to the solvent environment. This study reveals a fast time component which is attributed to the dipolar relaxation of the solvent and a slower time component related to the rotation of the dimethylamino group of DMABN.
In this work we demonstrate the use of the push-pull model system 4-(dimethylamino)benzonitrile (DMABN) as a convenient molecular probe to investigate the local solvation structure and dynamics by means of time-resolved infrared spectroscopy (TRIR).
There is a great need to assess the harmful effects or toxicities of chemicals to which man is exposed. In the present paper, the simplified molecular input line entry specification (SMILES) ...representation-based string kernel, together with the state-of-the-art support vector machine (SVM) algorithm, were used to classify the toxicity of chemicals from the US Environmental Protection Agency Distributed Structure-Searchable Toxicity (DSSTox) database network. In this method, the molecular structure can be directly encoded by a series of SMILES substrings that represent the presence of some chemical elements and different kinds of chemical bonds (double, triple and stereochemistry) in the molecules. Thus, SMILES string kernel can accurately and directly measure the similarities of molecules by a series of local information hidden in the molecules. Two model validation approaches, five-fold cross-validation and independent validation set, were used for assessing the predictive capability of our developed models. The results obtained indicate that SVM based on the SMILES string kernel can be regarded as a very promising and alternative modelling approach for potential toxicity prediction of chemicals.
Exosomes are small vesicles with a bilayer membrane structure secreted by a variety of cells. They are widely distributed in a variety of body fluids and contain proteins, nucleic acids and other ...components. They can mediate information transmission between cells and participate in a variety of physiological and pathological activities of cells. Hepatocytes, hepatic sinus endothelial cells and other cells were able to communicate with hepatic stellate cells via exosomes, and regulate the activation, migration, apoptosis and other biological activities of hepatic stellate cells. In this review, the recent advances in the regulation of exosomes on the biological activity of hepatic stellate cells were reviewed.
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