Phase separation near half-filling point in superconducting compounds

We present the model of superconducting ceramics using the single band extended Hubbard Hamiltonian. We investigate the simultaneous presence of antiferromagnetism (AF) and d-wave superconductivity (SC) in the coherent potential (CP) approximation applied to the on-site Coulomb repulsion $U$. We consider the hopping interaction, $\Delta t$, the inter-site charge-charge interaction, $V$, (creating SC), and the single site Hund's type exchange interaction, $F_{in}$, (creating AF). The influence of these interactions on the separation of superconducting and antiferromagnetic phases near the half-filling point is investigated. Results are compared with the experimental data for YBaCuO and NdCeCuO compounds.Comment: 4 pages, 4 figure

Band magnetism with inter-site correlations and interactions

We introduce the Hamiltonian to describe narrow band electrons. The physics of driving forces towards ferromagnetism is re-examined. Using different approximations it has been shown that the magnetic moments created by inter-site interaction and inter-site kinetic correlation decrease quickly with temperature. As a result of these interactions and the realistic density of states (DOS) the Curie temperatures calculated after fitting magnetic moments to their low temperature values are realistic. In the past the Curie temperatures calculated using only the on-site interaction were much higher than the experimental temperatures.Comment: 6 pages, 1 figur

Assessing the innervation of the dorsal wrist capsule using modified Sihler’s staining

Background: The aim of this study was to assess the innervation of the dorsal articular capsule of the wrist using modified Sihler’s staining. Materials and methods: Thirty dorsal wrist capsules were collected from 15 donors (both sides) within 12 hours of death. All the capsules were collected in the same manner — using the dorsal incision. The specimens were stained according to the protocol of the modified Sihler’s staining technique. The preserved capsules were analysed under 8–16× magnification of an optical microscope for the presence of major nerve trunks, their major and minor branches, and nerve connections. Results: The range of innervation visualised was that the posterior interosseous nerve innervated approximately 60% of the central part; the remaining area was innervated by the dorsal sensory branch of the radial nerve and medial antebrachial cutaneous nerve. The constant findings were the branches departing from the ulnar side of the posterior interosseous nerve and from the radial side, with an exception seen in 2 cases. A communicans branch between the posterior interosseous nerve and medial antebrachial cutaneous nerve was seen in all the specimens. The posterior interosseous nerve innervation extended beyond the level of the carpometacarpal joints II–V. Conclusions: The modified Sihler’s staining technique allows for transparent visibility of the nerves that innervate the dorsal wrist capsule. However, it does not allow as accurate assessment as does histological examination, especially regarding the evaluation of nerve endings. Nevertheless, this method provides a significantly larger area of nerve observation than is provided by histological examination

The median nerve in the carpal tunnel

A study of the variations of the course and branching pattern of the median nerve within the carpal tunnel were carried out on 60 wrists from 30 fresh cadavers autopsied in the Department of Forensic Medicine of Jagiellonian University Medical College. The results were compared with the literature. The study confirmed that the extraligamentous type of motor branch variation is most common. The transligamentous course of the nerve is of special importance: it is usually accompanied by hypertrophic muscle, and the nerve hidden within this muscle can easily be cut during transection of the retinaculum. The results proved the necessity of approaching the median nerve from the ulnar side when opening the carpal tunnel. (Folia Morphol 2011; 70, 1: 41-46

Ferromagnetic Systems with Hopping Interaction

We analyze the influence of hopping interaction on magnetic ordering. Scattering scheme of the Hubbard III approximation with included inter-site kinetic electron-electron correlation is used. The hopping interaction and inter-site correlation lead to two spin dependent effects: the band width correction and the band-shift correction. The band-shift correction factor causes an exchange splitting between the spin-up and spin-down spectrum, and its role is similar to the exchange interaction in the classic Stoner model. The spin dependent band width correction enhanced strongly by the inter-site kinetic correlation lowers the kinetic energy of electrons by decreasing the majority spin band width for some electron occupations with respect to the minority spin band width. The results show that in the case of the symmetrical density of states there is only ferromagnetic enhancement. For the strongly asymmetrical density of states there is a ferromagnetic transition

Median nerve thenar motor branch anatomical variations

Aim. The aim of this study was to determine the prevalence of the different types of the median nerve thenar motor branch and to compare them with literature data.Materials and Methods. This study has been conducted using median nerves dissected from cadavers stored in a 10% solution of formaldehyde at the Department of Anatomy, Jagiellonian University Medical College (JUMC) and cadavers from the Department of Forensic Medicine (JUMC). The research protocol was approved by the Jagiellonian University Ethics Committee (registry KBET/209/B/2002).Results. The studied group comprised of 8 (26,7%) women and 22 men (age between 23-92 years), yielding a total of 60 thenar motor branches (30 right vs. 30 left). Forty-seven (78,3%) nerves were classified as extraligamentous, 12 (20%) were subligamentous and 1 (1,7%) was transligamentous. As for the side of origin of the thenar motor branch in 45 cases (75%) it was the radial side and in 2 cases (3,33%) it was the ulnar side.Conclusions. The obtained results confirm that the extraligamentous type of the thenar motor branch is the most common and that the ulnar origin of the thenar motor branch is the rarest

Comparison of the histological structure of the tibial nerve and its terminal branches in the fresh and fresh-frozen cadavers

Background: The aim of this study was to compare the histological structure (cross-sectional area [CSA] and number of nerve fascicles) of the distal part of the tibial nerve (TN) and its terminal branches (medial plantar nerve [MPN], lateral plantar nerve [LPN]) in the fresh and fresh-frozen cadavers using computer assisted image analysis.Materials and methods: The TNs with terminal branches (MPN and LPN) were dissected from the fresh and fresh-frozen cadavers. Each nerve was harvested 5 mm proximally and respectively 5 mm distally from the TN bifurcation, marked, dehydrated, embedded in paraffin, sectioned at 2 μm slices and stained with haematoxylin and eosin. Then the specimens were photographed and analysed using Olympus cellSens software.Results: The fresh cadavers’ group comprised 60 feet (mean age 68.1 ± 15.2 years). The mean CSA and the number of nerve fascicles were respectively 15.25 ± 4.6 mm2, 30.35 ± 8.45 for the TN, 8.76 ± 1.93 mm2, 20.75 ± 7.04 for the MPN and 6.54 ± 2.02 mm2, 13.40 ± 5.22 for the LPN. The fresh-frozen cadavers’ group comprised 21 feet (mean age 75.1 ± 9.0 years). The mean CSA and the number of nerve fascicles were respectively 13.71 ± 5.66 mm2, 28.57 ± 8.00 for the TN, 7.55 ± 3.25 mm2, 18.00 ± 6.72 for the MPN and 4.29 ± 1.93 mm2, 11.33 ± 1.93 for the LPN. Only LPNs showed statistical differences in the CSA and the number of nerve fascicles between examined groups (p = 0.000, p = 0.037, respectively). A positive correlation was found between donors age and tibial nerve CSA in the fresh cadavers group (r = 0.44, p = 0.000). A statistical difference was found between the MPN and LPN both in the CSA and the number of nerve fascicles (p < 0.001, p < 0.001, respectively).Conclusions: The CSA and the number of nerve fascicles of the tibial and medial plantar nerves were similar in the fresh and fresh-frozen cadavers whilst different in the LPN. The TN showed increasing CSA with the advanced age in the fresh cadavers. The MPN had larger CSA and more nerve fascicles than the LPN