Data on the reaction γp→K^{+}Λ from the CLAS experiments are used to derive the leading multipoles, E_{0+}, M_{1-}, E_{1+}, and M_{1+}, from the production threshold to 2180 MeV in 24 slices of the ...invariant mass. The four multipoles are determined without any constraints. The multipoles are fitted using a multichannel L+P model that allows us to search for singularities and to extract the positions of poles on the complex energy plane in an almost model-independent method. The multipoles are also used as additional constraints in an energy-dependent analysis of a large body of pion and photoinduced reactions within the Bonn-Gatchina partial wave analysis. The study confirms the existence of poles due to nucleon resonances with spin parity J^{P}=1/2^{-}, 1/2^{+}, and 3/2^{+} in the region at about 1.9 GeV.
.
The isobar model EtaMAID has been updated with new and high precision data for
η
and
η
photoproduction on protons and neutrons from MAMI, ELSA, GRAAL and CLAS. The background is described in a ...recently developed Regge cut model, and for the resonance part the whole list of nucleon resonances has been investigated with 21
N
*
states contributing to
η
photoproduction and 12
N
*
states contributing to
η
photoproduction. A new approach is discussed to avoid double counting in the overlap region of Regge and resonances. A comparison is done among four newly updated partial waves analyses for observables and partial waves. Finally, the possibility of a narrow resonance near
W
=
1900
MeV is discussed, that would be able to explain unexpected energy and angular dependence of observables in
p
(
γ
,
η
)
p
near
η
threshold.
Electromagnetic resonance properties are uniquely defined at the pole and do not depend on the separation of the resonance from background or the decay channel. Photon-nucleon branching ratios are ...nowadays often quoted at the pole, and we generalize the considerations to the case of virtual photons. In this paper, we derive and compare relations for nucleon to baryon transition form factors both for the Breit-Wigner and the pole positions. Using the MAID2007 and SAID SM08 partial wave analyses of pion electroproduction data, we compare the $G_M$, $G_E$, and $G_C$ form factors for the $\Delta(1232)$ resonance excitation at the Breit-Wigner resonance and pole positions up to $Q^2=5$ GeV$^2$. We also explore the $E/M$ and $S/M$ ratios as functions of $Q^2$. Finally, for pole and residue extraction, we apply the Laurent + Pietarinen method.
PURPOSE OF THE STUDY The purpose of this study is to remind of the specific features of diagnosis and therapy of dorsal dislocations of the glenohumeral joint to prevent frequent neglect or ...misdiagnosis during primary treatment. Also, we strived to present our experience and outcomes of posterior dislocation treatment by McLaughlin procedure and its modified version. MATERIAL AND METHODS We retrospectively evaluated 7 patients who had been treated at our department in the period 2015-2019 by McLaughlin procedure or its modification. The group consisted of 5 men and 2 women aged 33-79 years. In five patients, the dislocation occurred during an epileptic seizure, in two patients during an accident. The patients were treated by McLaughlin procedure or the Neer modification of McLaughlin procedure. The deltoideopectoral surgical approach was always used. Based on the preoperative planning, we decided, or intraoperatively changed our decision, as to whether mere transposition of the subscapularis is satisfactory or whether transposition of the lesser tuberosity to the defect, a bone graft and arthroplasty are necessary. Postoperatively, the operated limb was fixed for 6 weeks in neutral position, which was followed by rehabilitation. RESULTS We evaluated subjective and objective outcomes of the surgery, the radiological finding and in 2 patients also a control CT scan. The function of the shoulder was assessed using the Constant shoulder score and the OSIS scoring system. The resulting score: the mean OSIS was 55.7 points (92.8%) and the mean Constant score was 86.2 points (86.2%), which we regard as a very good result. All patients consider the surgery successful and are satisfied with the outcome. No patient reported recurrent dislocation. DISCUSSION When treating the posterior dislocation of the shoulder, vital is the shoulder reducibility and also the presence or the size of reverse Hill-Sachs defect. The transfer of the subscapularis tendon can be performed as an open procedure or arthroscopically. Inveterate irreducible posterior dislocation of the shoulder is quite a rare diagnosis, which is why even at our department the McLauglin procedure is performed in the order of units per year only. CONCLUSIONS The surgical solution of inveterate posterior dislocation of the shoulder is hardly ever uncomplicated. The reduction alone is often insufficient and some other way of shoulder stabilisation is necessary, often times addressing the humeral head defect. In our to date experience, the McLaughlin procedure or the Neer s modification is an elegant and safe method to treat posterior dislocation with a humeral head defect. The functional outcomes are very good and enable the patients to reengage in everyday activities. Thanks to this procedure shoulder joint arthroplasty can be avoided in younger patients. Nonetheless, in defects that are greater than 50% of the head the replacement is necessary. Due to frequently associated rotator cuff injuries, the most often procedure indicated by us is the reverse total shoulder replacement. Key words: posterior dislocation of the shoulder, reverse Hill-Sachs defect, McLaughlin procedure, Neer s modification.
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