References to the identified CCTs are now available in CENTRAL, the Cochrane Collaboration repository for these studies. We call for adherence to the CONSORT statement in dentistry to improve reporting of CCTs in journals published in Spanish language.
Giant pseudocyst is a rare complication of incisional hernia repairs whose etiology and incidence remains unknown. We have reviewed all cases of abdominal incisional hernia repair in our abdominal wall unit since its creation 6 years ago. Pseudocyst formation was observed in seven cases out of 871 incisional hernia repair operations. Four of them underwent surgical exploration with excision of the mass. To the best of our knowledge, only 18 cases of giant pseudocyst have been described in the literature. From both our personal experience and the reported literature, we understand that abdominal pseudocyst is an extremely rare or underreported late complication of hernia repair surgery. The complete excision of the cyst and its fibrous wall is the definitive treatment of choice.
Laparoscopic surgery reduces, but not eliminates, the rate of incisional hernia. It is accepted that large trocar orifices should be sutured, in order to prevent future herniation. In morbidly obese patients, the closure of the anterior fascia is a very difficult job, and it does not prevent from preperitoneal herniation. Ventralex composite mesh is a very easy-to-place device, which closes satisfactorily both the peritoneal opening and the subcutaneous trocar pathway. We recommend its use for large diameter orifices and Hasson orifices in bariatric patients.
Increasingly, wireless networks are being used to provide connection services for devices running applications with very different quality of service requirements. Although this issue has been addressed by the IEEE 802.11e standard, the fact is that most networks deployed in home/office environments nowadays use IEEE 802.11a/b/g standard devices. Unfortunately, administrators often do not set configuration parameters of network devices to maximize resources performance, thus providing poor quality of service. In this paper, two IEEE 802.11a/b/g analytical performance evaluation models for mixed traffic Ad Hoc and infrastructure WLANs are presented, assuming that some network devices are executing single applications, like VoIP, videoIP or network browsing. In our analysis, network devices are grouped according to the expected traffic pattern of the applications they are running. Then, global and individual group goodput are calculated assuming a congested network. Based upon the outcome of this analysis for different settings of the device configuration parameters, it is shown that the performance of a standard home/office IEEE 802.11 wireless network can be significantly improved by choosing appropriate values of these parameters.
Purpose
In a printed circuit board assembly (PCBA), the coefficient of thermal expansion (CTE) mismatch between the solder joint materials has a detrimental impact on reliability. The mechanical stresses caused by the thermal changes of the assembly lead to fatigue and sometimes the failure of the solder joints. The purpose of this study is to propose a novel pad design to obtain an interrupted solder/substrate interface, to improve the PCBA reliability.
Design/methodology/approach
An interruption in the continuous intermetallic compound (IMC) layer of a solder joint was implemented, by the deposition of a silicone film in the pad, changing its geometry. That change allows a redistribution of stresses in the most ductile zone of the solder joint, the solder. The stress concentration at the solder/substrate interface is reduced, as well as the general state of stress at the solder joint.
Findings
A new way was developed to reduce the stress on the solder joints, caused by thermal variations, because of the different components CTEs mismatch. This new method consists of interrupting the IMC layers of the solder joint, strategically, redirecting the usual stresses to a more ductile area of the joint, the solder. This is an innovative method that allows increase the lifetime of PCBAs and the equipments.
Originality/value
In this study, a new pad design concept for higher solder joint reliability was developed to reduce the shear stress in the solder joints because of the CTE mismatch between all the solder joint components.
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