Measurement of Heavy-Flavor Properties at CMS and ATLAS

Thanks to the excellent performances of ATLAS and CMS in triggering on muon signals and reconstructing these particles down to low transverse momentum, large samples of heavy-flavored hadrons have been collected in the 2011 LHC run at sqrt(s) = 7 TeV. The analysis of these samples has enabled both experiments to perform competitive measurements of heavy-flavor properties, such as quarkonium polarization, lifetime and CP-violation measurements, hadron spectroscopy and branching ratios of rare B decays

Constraints on the Higgs boson total width using H*(126) -> ZZ events

Constraints are set on the Higgs boson decay width, Gamma_H, using off-shell production and decay to ZZ in the four-lepton (4l), or two-lepton-two-neutrino (2l2nu) final states. The analysis is based on the data collected in 2012 by the CMS experiment at the LHC, corresponding to an integrated luminosity L = 19.7 fb^{-1} at sqrt(s) = 8 TeV. A maximum-likelihood fit of invariant mass and kinematic discriminant distributions in the 4l case and of transverse mass or missing energy distributions in the 2l2nu case is performed. The result of it, combined with the 4l measurement near the resonance peak, leads to an upper limit on the Higgs boson width of Gamma_H < 4.2 x Gamma_H^SM at the 95% confidence level, assuming Gamma_H^SM = 4.15 MeV.Comment: 5 pages, 6 figures, proceedings to the XLIX Rencontres de Moriond session on Electroweak interactions and Unified theorie

Prospects for hadron spectroscopy at the CMS experiment

The CMS detector at the LHC will be able to detect hadron production at an unprecedented center-of-mass energy of 14 TeV. We present dedicated simulation studies for the measurement of the $B_c^+$-meson mass and lifetime using the exclusive decay channel $B_c^+ \rightarrow J/\psi \pi^+$. Moreover, quarkonium reconstruction capabilities in CMS are presented in terms of efficiency and expected resolution both in proton-proton collisions ($J/\psi$ reconstructed from the $B_s^0 \rightarrow J/\psi \phi$ decay channel) and in heavy ion collisions

The CMS High-Level Trigger

At the startup of the LHC, the CMS data acquisition is expected to be able to sustain an event readout rate of up to 100 kHz from the Level-1 trigger. These events will be read into a large processor farm which will run the "High-Level Trigger" (HLT) selection algorithms and will output a rate of about 150 Hz for permanent data storage. In this report HLT performances are shown for selections based on muons, electrons, photons, jets, missing transverse energy, tau leptons and b quarks: expected efficiencies, background rates and CPU time consumption are reported as well as relaxation criteria foreseen for a LHC startup instantaneous luminosity

Surgical treatment of gastrointestinal stromal tumors of the duodenum. A literature review

Background: Gastrointestinal stromal tumors (GIST) are the most frequent mesenchymal tumours in the digestive tract. The duodenal GIST (dGIST) is the rarest subtype, representing only 4–5% of all GIST, but up to 21% of the resected ones. The diagnostic and therapeutic management of dGIST may be difficult due to the rarity of this tumor, its anatomical location, and the clinical behavior that often mimic a variety of conditions; moreover, there is lack of consent for their treatment. This study has evaluated the scientific literature to provide consensus on the diagnosis of dGIST and to outline possible options for surgical treatment. Methods: An extensive research has been carried out on the electronic databases MEDLINE, Scopus, EMBASE and Cochrane to identify all clinical trials that report an event or case series of dGIST. Results: Eighty-six studies that met the inclusion criteria were identified with five hundred forty-nine patients with dGIST: twenty-seven patients were treated with pancreatoduodenectomy and ninety-six with only local resection (segmental/wedge resections); in four hundred twenty-six patients it is not possible identify the type of treatment performed (pancreatoduodenectomy or segmental/wedge resections). Conclusions: dGISTs are a very rare subset of GISTs. They may be asymptomatic or may involve symptoms of upper GI bleeding and abdominal pain at presentation. Because of the misleading clinical presentation the differential diagnosis may be difficult. Tumours smaller than 2 cm have a low biological aggressiveness and can be followed annually by endoscopic ultrasound. The biggest ones should undergo radical surgical resection (R0). In dGIST there is no uniformly adopted surgical strategy because of the low incidence, lack of experience, and the complex anatomy of the duodenum. Therefore, individually tailored surgical approach is recommended. R0 resection with 1–2 cm clear margin is required. Lymph node dissection is not recommended due to the low incidence of lymphatic metastases. Tumor rupture should be avoided

Bronchogenic cyst of the ileal mesentery: a case report and a review of literature

<p>Abstract</p> <p>Introduction</p> <p>Bronchogenic cyst is a rare clinical entity that occurs due to abnormal development of the foregut; the majority of bronchogenic cysts have been described in the mediastinum and they are rarely found in an extrathoracic location.</p> <p>Case presentation</p> <p>We describe the case of an intra-abdominal bronchogenic cyst of the mesentery, incidentally discovered during an emergency laparotomy for a perforated gastric ulcer in a 33-year-old Caucasian man.</p> <p>Conclusions</p> <p>Bronchogenic cyst should be considered in the differential diagnosis of subdiaphragmatic masses, even in an intraperitoneal location.</p

Tracking and Alignment with the Silicon Strip Tracker at the CMS Magnet Test Cosmic Challenge

Data were collected with a custom-built sub-structure of the silicon strip tracker, both during the preparation of the Magnet Test Cosmic Challenge and during the challenge itself. These data were used to evaluate performance of track reconstruction and detector alignment algorithms, both with and without magnetic field. The track reconstruction algorithm is described in detail and its performance presented, in terms of its efficiency, resolution and consistency with the results from other sub-detectors. A study of detector alignment is shown, including the use tracker construction information. The effect of alignment on track quality is discussed

Ilioinguinal nerve neurectomy is better than preservation in lichtenstein hernia repair. A systematic literature review and meta-analysis

Objective This study aimed to evaluate the incidence of chronic groin pain (primary outcome) and alterations of sensitivity (secondary outcome) after Lichtenstein inguinal hernia repair, comparing neurectomy with ilioinguinal nerve preservation surgery. Summary background data The exact cause of chronic groin postoperative pain after mesh inguinal hernia repair is usually unclear. Section of the ilioinguinal nerve (neurectomy) may reduce postoperative chronic pain. Methods We followed PRISMA guidelines to identify randomized studies reporting comparative outcomes of neurectomy versus ilioinguinal nerve preservation surgery during Lichtenstein hernia repairs. Studies were identified by searching in PubMed, Scopus, and Web of Science from April 2020. The protocol for this systematic review and meta-analysis was submitted and accepted from PROSPERO: CRD420201610. Results In this systematic review and meta-analysis, 16 RCTs were included and 1550 patients were evaluated: 756 patients underwent neurectomy (neurectomy group) vs 794 patients underwent ilioinguinal nerve preservation surgery (nerve preser- vation group). All included studies analyzed Lichtenstein hernia repair. The majority of the new studies and data comes from a relatively narrow geographic region; other bias of this meta-analysis is the suitability of pooling data for many of these studies. A statistically significant percentage of patients with prosthetic inguinal hernia repair had reduced groin pain a 6 months after surgery at 8.94% (38/425) in the neurectomy group versus 25.11% (113/450) in the nerve preservatio group [relative risk (RR) 0.39, 95% confidence interval (CI) 0.28–0.54; Z = 5.60 (P 0.00001)]. Neurectomy did no significantly increase the groin paresthesia 6 months after surgery at 8.5% (30/353) in the neurectomy group versu 4.5% (17/373) in the nerve preservation group [RR 1.62, 95% CI 0.94–2.80; Z = 1.74 (P = 0.08)]. At 12 months afte surgery, there is no advantage of neurectomy over chronic groin pain; no significant differences were found in th 12-month postoperative groin pain rate at 9% (9/100) in the neurectomy group versus 17.85% (20/112) in the inguina nerve preservation group [RR 0.50, 95% CI 0.24–1.05; Z = 1.83 (P = 0.07)]. One study (115 patients) reported dat about paresthesia at 12 months after surgery (7.27%, 4/55 in neurectomy group vs. 5%, 3/60 in nerve preservatio group) and results were not significantly different between the two groups [RR 1.45, 95% CI 0.34, 6.21;Z = 0.5 (P = 0.61)]. The subgroup analysis of the studies that identified the IIN showed a significant reduction of the 6th mont evaluation of pain in both groups and confirmed the same trend in favor of neurectomy reported in the previous overal analysis: statistically significant reduction of pain 6 months after surgery at 3.79% (6/158) in the neurectomy grou versus 14.6% (26/178) in the nerve preservation group [RR 0.28, 95% CI 0.13–0.63; Z = 3.10 (P = 0.002)]. Conclusion Ilioinguinal nerve identification in Lichtenstein inguinal hernia repair is the fundamental step to reduce or avoid postoperative pain. Prophylactic ilioinguinal nerve neurectomy seems to offer some advantages concerning pain in the first 6th month postoperative period, although it might be possible that the small number of cases contributed to the insignificancy regarding paresthesia and hypoesthesia. Nowadays, prudent surgeons should discuss with patients and their families the uncertain benefits and the potential risk of neurectomy before performing the hernioplasty