Effects of circumcision on male sexual functions： systematic review and meta-analysis

This meta-analysis was performed to assess sexual functions following adult male circumcision. We searched the Cochrane Central Register of Controlled Trials, PUBMED, EMBASE, the Cochrane Database of Systematic Review and Web of Science from their inception until January 2013 to identify all eligible studies that reported on men＇s sexual function after circumcision. The Cochrane Collaboration＇s RevMan 5.2 software was employed for data analysis, and the fixed or the random effect model was selected depending on the proportion of heterogeneity. We identified 10 studies, which described a total of 9317 circumcised and 9423 uncircumcised men who were evaluated for the association of circumcision with male sexual function. There were no significant differences in sexual desire （odds ratio （OR）： 0.99; 95% confidence interval （CI）： 0.92-1.06）, dyspareunia （OR： 1.12; 95% Ch 0.52-2.44）, premature ejaculation （OR. 1.13; 95% Ch 0.83-1.54）, ejaculation latency time （OR： 1.33; 95% Ch 0.69-1.97）, erectile dysfunctions （OR： 0.90; 95% Ch 0.65-1.25） and orgasm difficulties （OR： 0.97; 95% Ch 0.83-1.13）. These findings suggest that circumcision is unlikely to adversely affect male sexual functions. However, these results should be evaluated in light of the low quality of the existing evidence and the significant heterogeneity across the various studies. Well-designed and prospective studies are required for a further understanding of this topic.

Experimental study of transient pressure wave in the behind armor blunt trauma induced by different rifle bullets

Pressure wave plays an important role in the occurrence of behind armor blunt trauma(BABT),and ballistic gelatin is widely used as a surrogate of biological tissue in the research of BABT.Comparison of pressure wave in the gelatin behind armor for different rifle bullets is lacking.The aim of this study was to observe dynamic changes in pressure wave induced by ballistic blunt impact on the armored gelatin block and to compare the effects of bullet type on the parameters of the transient pressure wave.The gelatin blocks protected with National Institute of Justice(NIJ) class III bulletproof armor were shot by three types of rifle bullet with the same level of impact energy.The transient pressure signals at five locations were recorded with pressure sensors and three parameters(maximum pressure,maximum pressure impulse,and the duration of the first positive phase) were determined and discussed.The results indicated that the waveform and the twin peak of transient pressure wave were not related to the bullet type.However,the values of pressure wave's parameters were significantly affected by bullet type.Additionally,the attenuation of pressure amplitude followed the similar law for the three ammunitions.These findings may be helpful to get some insight in the BABT and improve the structure design of bullet.

Effect of electric pulse modification on mircostructure and properties of Ni-rich Al-Si piston alloy

In order to improve the properties of Ni-rich(2.5wt.%) Al-Si piston alloy, electric pulse modification was applied in fabricating the Ni-rich Al-Si piston alloy in this study. The effect of electric pulse modification on the mechanical properties of the Ni-rich Al-Si piston alloy was studied using optical microscope(OM), scanning electron microscope(SEM), X-ray diffraction(XRD), microhardness measurement and tensile strength testing.The results showed that the microstructures of Ni-rich Al-Si piston alloy treated by electric pulse modification were refined, the solid solubility of Cu, Ni, Si, etc. in α-Al matrix was improved, and furthermore, the microhardness and high-temperature tensile strength were increased by 9.41% and 17.5%, respectively. The distribution of second phases was also more uniform compared with that of a non-modified sample.

Hardware design of a localization system for staff in high-risk manufacturing areas

In this paper,we propose a hardware design for an effective real time indoor localization system for staff working in high-risk manufacturing areas.Because of the special requirements of our system,the chirp spread spectrum(CSS) is the most suitable indoor localization technology.The details of the new localization system are described.The system involves several anchors,tags,and a gateway,all of which use the nanoLOC TRX transceiver(NA5TR1) RF chip(Nanotron Co.,Germany),which is based on the CSS technology.To validate the effectiveness of our system,both ranging and localization tests were carried out.The difference between the ranging accuracy indoors and outdoors was small.The localization system can position indoor mobile staff precisely,enabling the establishment of an emergency rescue mechanism.

Modeling sintering behavior of metal fibers with different fiber angles

The formation of sintering necks between two metal fibers was investigated using the oval-oval model with respect to the fiber angle range of 0°-90°. Surface diffusion was assumed to be the predominant mechanism in every section of the junction of two metal fibers in this model, which was addressed numerically using the level- set method. The growth rates of the sintering necks in the direction of the bisector of obtuse angle, the bisector of acute angle and the fiber axis were discussed in detail. It is found that the growth rate of the sintering necks decreases with fiber angle increasing in the direction of the fiber axis and the bisector of acute angle. However, an opposite variation in growth rate of sintering necks can be found in the direction of the bisector of obtuse angle. The numerical simulation results show that the growth rate of the sintering necks is significantly affected by the initial local geomet- rical structure which is determined by the fiber angle.