Aim Laparoscopic appendectomy (LA) is not yet unanimously considered the gold standard treatment for appendicitis, despite the increasing use of advanced laparoscopic operations and the high ...incidence of the disease.
Method Due to the results of an audit which classified LA as widespread in Italy, a Consensus Conference was organized, in order to give evidence‐based answers to the most debated problems regarding the operation. After researching the literature, a panel of 20 experts were selected and interviewed on hot topics; a subsequent discussion using the Delphi methodology was utilized in the course of the consensus conference and submitted to the evaluation of an audience of surgeons.
Results Checkpoint statements were formulated whenever an agreement was reached. A level of evidence was then assigned to single statements and the process revised by two external reviewers.
Conclusion Consensus development guidelines are herein reported and regard diagnostic pathway, diagnostic laparoscopy, indications, behaviour in case of innocent appendix, technical aspects, learning curve; however, some questions remain unsolved due to the lack of evidence.
Zenkers diverticulum represents the most common form of pharyngo-oesophageal diverticula usually occurring on the left side of the neck. Due to its anatomical proximity to the thyroid, it can mimic ...a thyroid mass. Here we describe the case of an asymptomatic 49-year-old man referred to the Thyroid Clinic of the Policlinico Umberto I Hospital-Sapienza University of Rome for thyroid sonography due to a family history of autoimmune thyroid disease. The patients thyroid blood tests did not reveal any abnormalities. The sonographic examination showed a dishomogeneus and hypoechoic thyroid gland. In addition, in the third middle of the right lobe, a mass (with a diameter greater than 26 mm), with heterogeneous internal echogenicity, hypoechoic margins and internal hyperechoic spots was recorded, with no appreciable flow at the Doppler evaluation. The TI-RADS score was 4c. Hence, the patient underwent ultrasound-guided fine-needle aspiration cytology that revealed the presence of squamous cells without cytological atypia, erythrocytes, muscular and vegetable fibres, colonies of bacteria in the absence of inflammatory infiltrate. This was consistent with the diagnostic hypothesis of oesophagus diverticulum, which was confirmed by means of a barium-swallow oesophagography. This case report underlines the possibility that a suspicious thyroid mass may result from a Zenkers diverticulum, even if located on the right side, especially if the lesion has a heterogeneous echo-texture, a hypoechoic rim and internal hyperechoic spots.
We prove that, for
n
⩾
4
, there are
C
∞
nonnegative functions
f of
n variables (and even flat ones for
n
⩾
5
) which are not a finite sum of squares of
C
2
functions. For
n
=
1
, where a ...decomposition in a sum of two squares is always possible, we investigate the possibility of writing
f
=
g
2
. We prove that, in general, one cannot require a better regularity than
g
∈
C
1
. Assuming that
f vanishes at all its local minima, we prove that it is possible to get
g
∈
C
2
but that one cannot require any additional regularity.
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