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The authors describe a silicon nanoparticle-based fluorometric method for sensitive and selective detection of Cu. It is based on the catalytic action of Cu on the oxidation of cysteine (Cys) by oxygen to form cystine and the by-product HO. The generated HO is catalytically decomposed by Cu to generate hydroxyl radicals which oxidize and destroy the surface of SiNPs. As a result, the blue fluorescence of the SiNPs is quenched. The method has excellent selectivity due to the dual catalytic effects of Cu, which is much better than most previously reported nanomaterial-based assays for Cu. Under the optimal conditions, the method has low detection limit (29 nM) and a linear response in a concentration range from 0.05 μM to 15 μM. The method has been successfully applied to the determination of Cu in spiked real water samples, and the results agreed well with those obtained by the Chinese National Standard method (GB/T 7475-1987; AAS). Graphical abstract Schematic presentation of a fluorometric method for the determination of Cu based on the dual catalytic effects of Cu, and the oxidative effect of hydroxy radicals on the surface of silicon nanoparticles (SiNPs). The method has a 29 nM detection limit and good selectivity.

Patients with heart failure (HF) are prone to combine with renal insufficiency. Recently, LCZ696 has been used in the treatment of HF, but whether LCZ696 is better than angiotensin converting enzyme inhibitors/angiotensin receptor antagonists (ACEI/ARB) in renal protection for HF patients has not been investigated. Therefore, we conducted a meta-analysis focusing on LCZ696 and its role in preservation of renal function in HF patients. Embase, PubMed, the Cochrane Library and ClinicalTrials.gov databases were electronically searched for available randomized controlled trials (RCTs). HF patients taking LCZ696 or ACEI/ARB were assessed for renal adverse events. The last search date was Sep 20, 2019. A total of 14959 patients from 6 trials were included in this meta-analysis. As compared to ACEI/ARB, LCZ696 significantly reduced the risk of renal function deterioration (odds ratio 0.77, 95% confidence interval 0.61-0.97, P = 0.02). In summary, LCZ696 may have superior renal protection in HF patients compared with ACEI/ARB.

This paper designs a microchannel liquid cold plate suitable for array multi-chip cooling. The influence of aspect ratio of rectangular cross section on heat transfer and flow performance of microchannel cold plate was studied by numerical analysis. The optimal ratio of height to width of rectangular section is selected and its structure is optimized. The results show that when the equivalent diameter of rectangular cross-section is fixed, the friction coefficient f and Nusselt number Nu increase with the increase of aspect ratio of rectangular cross-section; after optimizing the structure of the channel, the microchannel cold plate exhibits good heat transfer characteristics of low pressure drop, realizing effective heat dissipation and meeting the requirements of pressure drop.

LetB2ndenote the Brualdi-Li matrix, and letρ2n=ρ(B2n)denote the Perron value of the Brualdi-Li matrix of order2n. We prove that2n(n-1/2-ρ2n)is monotonically decreasing for allnandρ2n<n-1/2-(e2-1)/4(e2+1)n, wheree=2.718281828459045….

Let ≥ 1 be an integer, let B 2 denote the Brualdi-Li matrix of order 2 , and let LB 2 denote the Laplacian matrices of Brualdi-Li tournament digraphs. We obtain the eigenvalues and eigenvectors of LB 2 .