2,559 research outputs found
b \bar b b\bar b production in proton-nucleus collisions at the LHC
A sizable rate of events, with several pairs of -quarks produced
contemporarily by multiple parton interactions, may be expected at very high
energies as a consequence of the large parton luminosities. The production
rates are further enhanced in hadron-nucleus reactions, which may represent a
convenient tool to study the phenomenon. We compare the different contributions
to production, due to single and double parton
scatterings, in collisions of protons with nuclei at the CERN-LHC.Comment: 13 pages, 4 figure
Zygomatic Implant Survival in 9 Ectodermal Dysplasia Patients with 3.5 to 7-year Follow Up
Ectodermal dysplasia syndrome is a complex group of genetic disorders identified by the abnormal development of the ectodermal structures. The aim of this retrospective clinical case series report was to evaluate the outcomes of the ectodermal dysplasia syndrome patients that underwent zygomatic implant surgery.
Materials and Methods: A total of 9 ectodermal dysplasia syndrome patients aged between 21 and 56 years (mean age 36.8) with severely atrophic maxilla were included in this study. All the patients were treated with a total of 19 zygomatic implants. The mean follow-up of the patients was 55 months (with a range of 44\u201384 months). The implant survival rate was evaluated as a primary outcome. The intra- and postoperative
complications were evaluated as additional criteria for success.
Results: The overall implant survival rate was 100% without any complications. Final or provisional prosthesis was delivered on the same day of surgery, which resulted in an improvement of the quality of life of the patients.
Conclusion: According to the results of this study, zygomatic surgery can be considered
as a viable and safe alternative to conventional treatment modalities for oral
rehabilitation of ectodermal dysplasia syndrome patients
Same-sign W pair production as a probe of double parton scattering at the LHC
We study the production of same-sign W boson pairs at the LHC in double
parton interactions. Compared with simple factorised double parton
distributions (dPDFs), we show that the recently developed dPDFs, GS09, lead to
non-trivial kinematic correlations between the W bosons. A numerical study of
the prospects for observing this process using same-sign dilepton signatures,
including same-sign WWjj, di-boson and heavy flavour backgrounds, at 14 TeV
centre-of-mass energy is then performed. It is shown that a small excess of
same-sign dilepton events from double parton scattering over a background
dominated by single scattering WZ(gamma*) production could be observed at the
LHC.Comment: 14 pages, 8 figures. Added references, slight changes in the text
Implant supported cantilevered fixed dental rehabilitations in partially edentulous patients : systematic review of the literature. Part I
Objectives: To investigate in which clinical situations a cantilever fixed implant supported restorations can be a treatment alternative and which complications are reported. Materials and Methods: Two operators screened the literature (MEDLINE, EMBASE) and performed a hand search on the main journals dealing with implantology and prosthetics until 31 December 2017. Only articles that considered cantilever implant fixed restorations with at least 10 patients and with a mean follow-up of at least 5\ua0year were selected. The outcome variables were survival of implants and prosthesis, mechanical, technical and biological complications, marginal bone loss. The review was performed according to the PRISMA statements. Risk of bias assessment was evaluated. Failure and complication rates were analysed using random effect Poisson regression models to obtain summary estimate of 5- and 10-year survival and complication rates. Results: A total of nine papers were selected for partially edentulous patients and reported high survival rate of the prosthesis. The estimated survival rate for 5\u201310\ua0years was calculated to be 98.4% for the implants and 99.2% for the rehabilitations. Mechanical, technical and biological complications were reported with a cumulative 5\u201310\ua0years complication rate of 28.66% and 26.57% for the patients and for the prosthesis, respectively. Two papers for single implant supporting 2-unit cantilever were not sufficient to draw conclusions. Conclusions: There is evidence that cantilever can be successful treatment in partially edentulous patients. In two adjacent edentulous sites, data are not yet sufficient
Microsurgical re-treatment of an endodontically treated tooth with an apically located incomplete vertical root fracture: a clinical case report
Although it is challenging, the early diagnosis of a vertical root fracture (VRF) is crucial in order to ensure tooth preservation. The purpose of this clinical case report was to describe reparative surgery performed to treat a tooth affected by an incomplete VRF. A 26 year old male patient was suspected to have a VRF in a maxillary left central incisor, and an exploratory flap was performed in order to confirm the diagnosis. After detecting the fracture, the lesion was surgically treated, the fracture and the infected root-end were removed, and a platelet-rich plasma membrane was used to cover the defect in order to prevent bacterial migration. A 24 month clinical and radiological follow-up examination showed that the tooth was asymptomatic and that the healing process was in progress. The surgical approach described here may be considered an effective treatment for a combined endodontic-periodontal lesion originating from an incomplete VRF and a recurrent periapical lesion
Multiple Parton Interactions in Z+jets production at the LHC. A comparison of factorized and non--factorized double parton distribution functions
We examine the contribution of Multiple Parton Interactions to Z+n-jets
production at the LHC, n=2,3,4, where the Z boson is assumed to decay
leptonically. We compare the results obtained with the correlated GS09 double
parton distribution function with those obtained with two instances of fully
factorized single parton distribution functions: MSTW2008LO and CTEQ6LO. It
appears quite feasible to measure the MPI contribution to Z+2/3/4 jets already
in the first phase of the LHC with a total luminosity of one inverse femtobarn
at 7 TeV. If as expected the trigger threshold for single photons is around 80
GeV, Z+2-jets production may well turn out to be more easily observable than
the gamma+3-jets channel. The MPI cross section is dominated by relatively soft
events with two jets balancing in transverse momentum.Comment: 15 pages, 3 plot
Clinical outcomes of fully and partially threaded zygomatic implants in a cohort of patients with minimum 7.5-year follow-up
OBJECTIVE: The aim of this retrospective case series report was to evaluate the results of oral rehabilitation with extra-sinus zygomatic implant surgery with a minimum follow-up of 7.5 years.
PATIENTS AND METHODS: A total of 35 patients with 87 zygomatic implants were included. The mean follow-up period of the patients was 93 months. The zygomatic implant survival and complications were evaluated as criteria for success.
RESULTS: There were no implant failures. Overall success rate without complications for zygomatic implant was 88.5%. Complications developed in 4 patients (1 cutaneous fistula and 3 mucositis). According to the results on an implant basis, patients with previously failed conventional implants had greater probability of complications. Patients with quad zygomatic implants had higher incidence of complications than those with two zygomatic implants. Fully threaded implant design was associated with higher incidence of mucositis than partially threaded design. No relation was found between implant success and smoking, prosthesis type, and antagonist dentition. When conducting the analysis using the patient as unit, only the antagonist dentition showed significant difference, the worst outcome being associated with the Toronto resin prosthesis.
CONCLUSIONS: Zygomatic implants can be considered as a safe alternative to conventional implant insertions and bone grafting procedures in oral rehabilitation of patients with severely atrophic maxillary bone
QCD
We discuss issues of QCD at the LHC including parton distributions, Monte
Carlo event generators, the available next-to-leading order calculations,
resummation, photon production, small x physics, double parton scattering, and
backgrounds to Higgs production.Comment: 115 pages, Latex, 47 figures, to appear in the Report of the ``1999
CERN Workshop on SM Physics (and more) at the LHC'', S. Catani, M. Dittmar,
D. Soper, W.J. Stirling, S. Tapprogge (convenors
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