Laparoscopic versus Open Surgery in Complicated Appendicitis in Children Less Than 5 Years Old: A Six-Year Single-Centre Experience

Introduction. Acute appendicitis is the most common surgical emergency in the pediatric population. The peak incidence occurs in the first decade of life, while it is uncommon to face appendicitis in children younger than 5 years of age. Laparoscopy is now demonstrated to be the optimal approach also to treat complicated appendicitis, but in very young children this standardized operation is not always easy to perform. Material and Methods. From January 2009 to December 2015 we operated on 525 acute appendicitis, with 120 patients less than 5 years of age. Results. 90 children had a complicated appendicitis (localized or diffuse peritonitis): 43 (48%) were operated on by open approach and 47 (52%) by laparoscopy. The overall incidence of postoperative complications was greater in the open appendectomy group (63% versus 26%) and all severe complications requiring reintervention (6% of cases: 3 postoperative abscesses resolved with ultrasound guided percutaneous abscess drainage; 1 tubal surgery for salpingitis; 1 adhesion-related ileus requiring relaparotomy) were mostly associated with open surgery. Conclusions. Laparoscopic surgery resulted as the best approach for treating complicated appendicitis also in younger children, with minor and less severe postoperative complications compared to open surgery

Compressively-strained, buried-channel Si0.7Si_{0.7}Ge0.3_{0.3} p-MOSFETs fabricated on SiGe virtual substrates using a 0.25 µm CMOS process

Enhanced performance is demonstrated from a buried, compressively strained-Si0.7Ge0.3 p-MOSFET fabricated on a relaxed Si0.85Ge0.15 using a high thermal budget 0.25 µm CMOS process. The devices are designed to be fully compatible with a strained-Si CMOS process but offers a number of potential benefits over a surface channel p-MOSFET for certain circuit applications. Transconductance, on-current, hole velocity and mobility enhancements are observed over surface strained-Si channel devices on both Si0.85Ge0.15 and Si0.8Ge0.2 virtual substrates and the bulk Si control devices for constant effective channel length. The buried channel devices exhibit enhancements over the Si control devices of 93% in on-current and 62% in hole velocity for 0.25 µm effective channel length devices without compromising the subthreshold characteristics. The extracted effective mobility for the buried channel device is over 40% greater than the universal mobility curve for bulk Si p-MOS devices at 0.55 MV/cm vertical effective electric fields. Index Terms—CMOS, p-MOSFET, strained-Si, SiGe, quantum well, thermal budget, drain current enhancements, transconductance enhancements, virtual substrate

W(111) surface: an experimental and theoretical photoemission study

A detailed analysis of W(111) surface has been carried out by means of photoemission spectroscopy, together with a theoretical study of the electronic structure of the surface based on a tight binding Hamiltonian. During such a study the results from angular integrated and angular resolved ultraviolet photoemission spectroscopy have been compared with the computed surface density of states. This allowed the unique assignement of the surface sensitive features to surface states and resonances; the use of the polarized continuum of Synchrotron Radiation excitation source made possible to extend such an analysis to the determination of the state symmetries. The picture which emerges for the W(111) surface shows a remarkable feature: the surface states and resonances bands have a very small dispersion in the 2D BZ, due to the large surface atoms separation. The effect is so large that the K parallel integrated surface DOS is interpretable in terms of single d-orbital derived peaks