Novel Mg-based alloys by selective laser melting for biomedical applications: microstructure evolution, microhardness and in vitro degradation behaviour

Laser-melted Mg-3Zn-xDy (x = 0, 1, 3, 5 wt. %) alloys were investigated as candidate materials for biodegradable metallic implant applications. The results showed that the α-Mg, MgZn2 and Mg-Zn-Dy phases were distributed in the Dy-containing alloys. Due to the addition of Dy, the grain size was significantly refined. As the grain size decreased and the second phase content increased, the hardness monotonously increased. The degradation characteristics analysis via immersion testing indicated that the degradation rate of the laser-melted Mg-3Zn-1Dy alloys was remarkably reduced, evidenced by the corresponding lower average hydrogen evolution rate. Consequently, the Mg-3Zn-1Dy was considered to be a promising candidate for implant applications, due to the appropriate rate of mechanical integrity loss during degradation. Overall, the mitigated degradation rate was attributed to the refined grains, the homogeneous microstructure as well as a certain amount of second phase produced during the process of selective laser melting

Cloning of the quail PIWI gene and characterization of PIWI binding to small RNAs.

The PIWI protein regulates gene expression at the epigenetic and post-transcriptional level with a variety of endogenous small non-coding RNAs. In poultry, the biological function of the PIWI protein and PIWI binding to small RNAs had not been determined. The present study cloned and analyzed the sequences of the PIWIL1 protein. We also characterized PIWIL1 binding to small RNAs from adult quail testis, where the PIWIL1 protein is specifically expressed. Small RNAs showed a strong peak at 24-27 nt in the testicular RNA library, mapped primarily to repeat sequences and were similar to rasiRNAs. MicroRNAs (miRNAs) were abundant in the ovarian RNA library at a peak of 22 nt

US-Guided Percutaneous Radiofrequency versus Microwave Ablation for Benign Thyroid Nodules: A Prospective Multicenter Study

Abstract Compared with microwave ablation (MWA), percutaneous radiofrequency ablation (RFA) and laser ablation (LA) have been recommended as minimally invasive treatments for patients with symptomatic benign thyroid nodules (BTNs) because of the large number of clinical applications. This prospective multicenter study sought to evaluate the clinical outcomes of RFA and MWA for BTNs. In eight participating institutions, the total number of 1252 patients treated by RFA and MWA were 649 ones with 687 BTNs and 603 ones with 664 BTNs, respectively. The clinical outcomes including the nodular maximal diameter reduction ratio (MDRR), the nodular volume reduction ratio (VRR), and the incidence of complications were compared to evaluate the efficacy and safety of the two techniques. The results for the nodular MDRR and VRR in the RFA group were significantly better than those in the MWA group at 6 months and later follow-up, and the major complication rates of 4.78% and 6.63% in RFA and MWA groups showed no statistically significant differences. In conclusion, both RFA and MWA are safe and effective techniques for selected patients with symptomatic BTNs. The achieved MDRR and VRR in the RFA group were greater than those in the MWA group at 6 months and later follow-up

Monodisperse core-shell structured magnetic mesoporous aluminosilicate nanospheres with large dendritic mesochannels

The rational design and precise synthesis of multifunctional hybrid nanostructures with a tailored active core and a large, dendritic, modified mesoporous structured shell can promote catalysis, energy storage, and biological applications. Here, an oil-water biphase stratification coating strategy has been developed to prepare monodisperse magnetic dendritic mesoporous silica core-shell structured nanospheres. These sophisticated Fe3O4@SiO2@dendritic-mSiO2 nanospheres feature large dendritic open pores (2.7 and 10.3 nm). Significantly, the silica shells can be converted into dendritic mesoporous aluminosilicate frameworks with unchanged porosity, a Si/Al molar ratio of 14, and remarkably strong acidic sites, through a post-synthesis approach. In addition, the resultant magnetic dendritic mesoporous aluminosilicate nanospheres exhibit outstanding properties and promising application in phosphate removal from wastewater

New twinning route in face-centered cubic nanocrystalline metals

Twin nucleation in a face-centered cubic crystal is believed to be accomplished through the formation of twinning partial dislocations on consecutive atomic planes. Twinning should thus be highly unfavorable in face-centered cubic metals with high twin-fault energy barriers, such as Al, Ni, and Pt, but instead is often observed. Here, we report an in situ atomic-scale observation of twin nucleation in nanocrystalline Pt. Unlike the classical twinning route, deformation twinning initiated through the formation of two stacking faults separated by a single atomic layer, and proceeded with the emission of a partial dislocation in between these two stacking faults. Through this route, a three-layer twin was nucleated without a mandatory layer-by-layer twinning process. This route is facilitated by grain boundaries, abundant in nanocrystalline metals, that promote the nucleation of separated but closely spaced partial dislocations, thus enabling an effective bypassing of the high twin-fault energy barrier

Pre-miRNAs and mature miRNAs identified in three libraries.

<p>Pre-miRNAs and mature miRNAs identified in three libraries.</p

Properties of unannotated unique reads in the testis.

<p>A: Chromosomal distribution of exons (top), repeat sequences (middle) and unannotated unique reads (bottom). The number of bases in exons of Refseq genes and repeats are plotted as a percentage of overall chromosome length. The numbers of piRNAs are normalized to chromosome length and plotted. B: Density analysis of exons (red), repeat sequences (green) and unannotated unique reads (with the positive strand in blue and the negative strand in purple) along chromosome 16. The densities of exons and repeats were using a 50 kB window, scanning the genome in increments of 1000 bases. Unannotaed uniques densities were determined by calculating a moving average of reads in a 5 kB sliding window (100 base increments) along each chromosome. Only reads that map 1 to 5 times to the genome were used in density analysis.</p

The PIWIL1 protein.

<p>A: Complete amino acid sequence of PIWIL1; PAZ domain, red; PIWI domain, blue. B: A phylogenetic tree of the PIWIL1 protein generated using UPGMA.</p

<i>PIWIL1</i> is specifically expressed in the testis.

<p>A: Northern blot analysis of <i>PIWIL1</i> expression in adult tissues with <i>β-actin</i> as the loading control. B: Western blot analysis of adult tissues; H, heart; L, live; K, kidney; B, brain; T, testis; O, ovary; F, lung; XJ, pectoral muscle.</p

Overdose intake of Neu5Gc triggers colorectal inflammation and alters liver metabolism

A positive correlation between massive red meat consumption with colorectal cancer had been reported. Given the complexity of meat components, we focused on investigating the role of Neu5Gc in human healthy. Two groups, either feeding with normal and overdose concentration of Neu5Gc for two weeks, to mimic the normal and overconsumption of red meat conditions in human, respectively. The colorectal transcriptomes revealed that Neu5Gc promotes intestinal immune response and identified the hub genes positively correlated with colorectal cancer such as Tnf, Cd19, Muc13, and Nso2,. The colorectal cancer patients have a 25–30% chance of developing liver metastases, thus we sequenced the liver and revealed the role of Neu5Gc in regulating cell metabolism. Moreover, we found that Neu5Gc negatively regulates the expression of Cmah. We conclude that high Neu5Gc intake promotes colorectal inflammatory responses in ApcMin/+ mice, and suppresses colorectal and hepatic metabolic and digestive processes through Cmah inhibition.</p