Laparoscopy for management of nontraumatic acute abdomen

Secţia Chirurgie, Spitalul Municipal de Urgenţă, Moineşti, România, Al XII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova cu participare internațională 23-25 septembrie 2015Introducere: Laparoscopia în abdomenul acut are atât rol în stabilirea diagnosticului, confirmându-l în situaţiile echivoce, cât şi în orientarea strategiei terapeutice cu avantajele chirurgiei mini-invazive. Material şi metode: Studiul nostru evaluează 873 de cazuri de abdomen acut nontraumatic (exceptând colecistita acută) abordate laparoscopic în perioada 2010-2014, urmarindu-se concordanţa diagnosticului pre- şi postoperator, stabilirea unui diagnostic intraoperator cert, incidenţa intervenţiilor laparoscopice cât şi complicaţiile acestora. Rezultate: Diagnosticul intraoperator a fost de apendicită acută în 653 (75%) de cazuri, urgenţele ginecologice au fost certificate la 146 (17%) de pacienţi (chist ovarian eclatat, sarcina extrauterină, boala inflamatorie pelvină), 52 (6%) de pacienţi au fost diagnosticaţi cu ulcer perforat, 22 de cazuri fiind înregistrate cu alte patologii (pancreatite acute, perforaţii intestinale cu peritonite, diverticul Meckel perforat, infarcte enteromezenterice, peritonita TBC). Incidente şi accidente au fost întâlnite la 56 (6,5%) de pacienţi, au fost înregistrate 33 (3,7%) de conversii, complicaţii postoperatorii fiind înregistrate în 37 (4,2%) de cazuri. Concluzii: Laparoscopia diagnostică este o modalitate optimă diagnostică în cazurile de abdomen acut non-traumatic, fiind salutară în cazurile de apendicită acută, urgenţe ginecologice şi peritonita de etiologie neprecizată cu posibilitatea rezolvării pe această cale a patologiei identificate, în abdomenul acut laparoscopia fiind ultimul mijloc diagnostic şi primul mijloc terapeutic.Aims: Laparoscopy for acute abdomen is important either for diagnostic, when there is uncertainty in establishing the etiology, and also has a therapeutic role with the well known advantages of mini-invasive surgery. Material and methods: Our study evaluates 873 patients of nontraumatic acute abdomen (excepting acute cholecystitis), approached laparoscopically during 2010-2014. The following factors were pursued: the concordance between pre- and postoperative diagnostic, the establishment of a certain intraoperative diagnostic, incidence of laparoscopic interventions and their complications. Results: There were 653 (75%) cases of acute appendicitis, 146 patients with gynecological (ruptured ovarian cyst, ectopic pregnancy, inflammatory pelvic disease), 52 (6%) patients with perforated ulcer, 22 cases with other pathologies (acute pancreatitis, enteral perforations, perforations of Meckel diverticulum, entero-mesenteric infarction, tuberculous peritonitis), confirmed laparoscopically. Incidents and accidents were encountered in 56 (6.5%) cases, there were 33 (3.7%) conversions to open technique and for 37 (4.2%) patients were recorded postoperative complications. Conclusions: Diagnostic laparoscopy is an optimal method of diagnostic confirmation for cases of non-traumatic acute abdomen especially for acute appendicitis, gynecological emergencies and peritonitis of unknown etiology with the possibility of laparoscopic treatment of these pathologies, being also the last option for diagnostic and the first solution for treatment

Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE

Measurement of the t t-bar production cross section in the dilepton channel in pp collisions at sqrt(s) = 7 TeV

The t t-bar production cross section (sigma[t t-bar]) is measured in proton-proton collisions at sqrt(s) = 7 TeV in data collected by the CMS experiment, corresponding to an integrated luminosity of 2.3 inverse femtobarns. The measurement is performed in events with two leptons (electrons or muons) in the final state, at least two jets identified as jets originating from b quarks, and the presence of an imbalance in transverse momentum. The measured value of sigma[t t-bar] for a top-quark mass of 172.5 GeV is 161.9 +/- 2.5 (stat.) +5.1/-5.0 (syst.) +/- 3.6(lumi.) pb, consistent with the prediction of the standard model.Comment: Replaced with published version. Included journal reference and DO

Combined search for the quarks of a sequential fourth generation

Results are presented from a search for a fourth generation of quarks produced singly or in pairs in a data set corresponding to an integrated luminosity of 5 inverse femtobarns recorded by the CMS experiment at the LHC in 2011. A novel strategy has been developed for a combined search for quarks of the up and down type in decay channels with at least one isolated muon or electron. Limits on the mass of the fourth-generation quarks and the relevant Cabibbo-Kobayashi-Maskawa matrix elements are derived in the context of a simple extension of the standard model with a sequential fourth generation of fermions. The existence of mass-degenerate fourth-generation quarks with masses below 685 GeV is excluded at 95% confidence level for minimal off-diagonal mixing between the third- and the fourth-generation quarks. With a mass difference of 25 GeV between the quark masses, the obtained limit on the masses of the fourth-generation quarks shifts by about +/- 20 GeV. These results significantly reduce the allowed parameter space for a fourth generation of fermions.Comment: Replaced with published version. Added journal reference and DO

Search for anomalous t t-bar production in the highly-boosted all-hadronic final state

A search is presented for a massive particle, generically referred to as a Z', decaying into a t t-bar pair. The search focuses on Z' resonances that are sufficiently massive to produce highly Lorentz-boosted top quarks, which yield collimated decay products that are partially or fully merged into single jets. The analysis uses new methods to analyze jet substructure, providing suppression of the non-top multijet backgrounds. The analysis is based on a data sample of proton-proton collisions at a center-of-mass energy of 7 TeV, corresponding to an integrated luminosity of 5 inverse femtobarns. Upper limits in the range of 1 pb are set on the product of the production cross section and branching fraction for a topcolor Z' modeled for several widths, as well as for a Randall--Sundrum Kaluza--Klein gluon. In addition, the results constrain any enhancement in t t-bar production beyond expectations of the standard model for t t-bar invariant masses larger than 1 TeV.Comment: Submitted to the Journal of High Energy Physics; this version includes a minor typo correction that will be submitted as an erratu

Search for New Physics with Jets and Missing Transverse Momentum in pp collisions at sqrt(s) = 7 TeV

A search for new physics is presented based on an event signature of at least three jets accompanied by large missing transverse momentum, using a data sample corresponding to an integrated luminosity of 36 inverse picobarns collected in proton--proton collisions at sqrt(s)=7 TeV with the CMS detector at the LHC. No excess of events is observed above the expected standard model backgrounds, which are all estimated from the data. Exclusion limits are presented for the constrained minimal supersymmetric extension of the standard model. Cross section limits are also presented using simplified models with new particles decaying to an undetected particle and one or two jets

Measurement of the Z/gamma* + b-jet cross section in pp collisions at 7 TeV

The production of b jets in association with a Z/gamma* boson is studied using proton-proton collisions delivered by the LHC at a centre-of-mass energy of 7 TeV and recorded by the CMS detector. The inclusive cross section for Z/gamma* + b-jet production is measured in a sample corresponding to an integrated luminosity of 2.2 inverse femtobarns. The Z/gamma* + b-jet cross section with Z/gamma* to ll (where ll = ee or mu mu) for events with the invariant mass 60 < M(ll) < 120 GeV, at least one b jet at the hadron level with pT > 25 GeV and abs(eta) < 2.1, and a separation between the leptons and the jets of Delta R > 0.5 is found to be 5.84 +/- 0.08 (stat.) +/- 0.72 (syst.) +(0.25)/-(0.55) (theory) pb. The kinematic properties of the events are also studied and found to be in agreement with the predictions made by the MadGraph event generator with the parton shower and the hadronisation performed by PYTHIA.Comment: Submitted to the Journal of High Energy Physic

Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum