Vasectomy reversal in China during the recent decade: insights from a multicenter retrospective investigation.

To date, there is little information about the demography of vasectomy reversal (VR) patients or the factors currently influencing VR effectiveness in China, especially after the universal two-child policy was released in 2015. In this research, demographic data and perioperative medical records of VR patients were extracted from seven major hospitals in different provinces or municipalities of China. Meanwhile, a telephone survey of the patients was conducted to collect follow-up information. Eventually, 448 VR cases from the past 13 years were included. The results were analyzed by stratified comparison to investigate factors that can influence postoperative vas deferens patency and pregnancy rate. Appropriately statistical methods were used, and all of the protocols were approved by the Ethics Committees of the institutes in this research. The results showed that the annual operation volume of VR quadrupled after the two-child policy was implemented. Nonmicrosurgery and a long duration of vasectomy were significantly associated with a lower patency rate. A follow-up survey showed that the general postoperative pregnancy rate was 27.2%. For female partners over the age of 35 years, the postoperative pregnancy rate showed a more severe decline, but only 35.5% of them had been given a fertility examination before their husbands' VR surgery. Our work revealed that more patients in China have been demanding VR in recent years. High-quality microsurgery and a short duration of vasectomy are crucial for restoring patency by VR. Clinical andrologists should perform a preoperative fertility evaluation of the patients' female partners.

Removal of cadmium from wastewater by magnetic zeolite synthesized from natural, low-grade molybdenum.

Zeolite has a high adsorption capacity for heavy metals, but it is difficult to separate from the medium because of its small particle size. In this study, magnetic zeolite was synthesized from natural, low-grade molybdenum ore by adding nano ferroferric oxide (saturation magnetization 83.43 emu/g) directly in the hydrothermal synthesis process, which was used to adsorb cadmium from wastewater. The results of scanning electron microscopy showed that the nano ferroferric oxide was adhered to the surface of the zeolite to make it magnetic. The vibrating sample magnetometer showed that the larger the amount of nano ferroferric oxide added, the higher the saturation magnetization of the magnetic zeolite. The saturation magnetization of the magnetic zeolite with a loading proportion of 25% was 18.18 emu/g with a specific surface area of 459.8 m2/g. The adsorption experiments showed that when the pH value is greater than 4, the adsorption capacity of magnetic zeolite is high and stable, and the theoretical maximum adsorption capacity is 204.2 mg Cd/g. Na+ and Ca2+ have different inhibitory functions on the adsorption capacity. The mapping graphs showed that cadmium is captured by the magnetic zeolite after contact with cadmium, and XRD confirmed the presence of cadmium oxide in the magnetic zeolite after adsorption, XPS and EDS results indicated that ion exchange is one of the main mechanisms of cadmium adsorption by magnetic zeolites, and electrostatic adsorption may also have a contribution.

Synthesis and thermotropic studies of a new series of teraryl liquid crystals 2-(4'-alkoxybiphen-4-yl)-5-cyanopyridines.

A new series of teraryl 2-(4'-alkoxybiphen-4-yl)-5-cyanopyridines (nO-PPPyCN, n = 2-8) compounds, bearing a cyanopyridine terminus, were synthesized using a short 2-step reaction with overall yields between 33% and 69%. Spectral analyses were in accord with the expected structures. Thermotropic behavior of the teraryl compounds was investigated using polarised optical microscopy and differential scanning calorimetry. All compounds exhibited both enantiotropic nematic and smectic A phases, with an additional enantiotropic smectic C phase when n = 7 and 8. Polymesomorphism appears to be a common behavior in this series of linear liquid crystal compounds.