Triangular lattice models for pattern formation by core-shell particles with different shell thicknesses.

Triangular lattice models for pattern formation by hard-core soft-shell particles at interfaces are introduced and studied in order to determine the effect of the shell thickness and structure. In model I, we consider particles with hard-cores covered by shells of cross-linked polymeric chains. In model II, such inner shell is covered by a much softer outer shell. In both models, the hard cores can occupy sites of the triangular lattice, and nearest-neighbor repulsion following from overlapping shells is assumed. The capillary force is represented by the second or the fifth neighbor attraction in model I or II, respectively. Ground states with fixed chemical potential µ or with fixed fraction of occupied sites c are thoroughly studied. For T > 0, the µ(c) isotherms, compressibility and specific heat are calculated by Monte Carlo simulations. In model II, 6 ordered periodic patterns occur in addition to 4 phases found in model I. These additional phases, however, are stable only at the phase coexistence lines at the (µ, T) diagram, which otherwise looks like the diagram of model I. In the canonical ensemble, these 6 phases and interfaces between them appear in model II for large intervals of c and the number of possible patterns is much larger than in model I. We calculated line tensions for different interfaces, and found that the favorable orientation of the interface corresponds to its smoothest shape in both models.

Abashian-Booth-Crowe effect in basic double-pionic fusion: a new resonance?

We report on an exclusive and kinematically complete high-statistics measurement of the basic double-pionic fusion reaction pn→dπ(0)π(0) over the full energy region of the ABC effect, a pronounced low-mass enhancement in the ππ-invariant mass spectrum. The measurements, which cover also the transition region to the conventional t-channel ΔΔ process, were performed with the upgraded WASA detector setup at COSY. The data reveal the Abashian-Booth-Crowe effect to be uniquely correlated with a Lorentzian energy dependence in the integral cross section. The observables are consistent with a narrow resonance with m=2.37 GeV, Γ≈70 MeV and I(J(P))=0(3(+)) in both pn and ΔΔ systems. Necessary further tests of the resonance interpretation are discussed.

Estimation of endogenous adenosine activity at adenosine receptors in guinea-pig ileum using a new pharmacological method.

AIM: Adenosine modulates neurotransmission and in the intestine adenosine is continuously released both from nerves and from smooth muscle. The main effect is modulation of contractile activity by inhibition of neurotransmitter release and by direct smooth muscle relaxation. Estimation of adenosine concentration at the receptors is difficult due to metabolic inactivation. We hypothesized that endogenous adenosine concentrations can be calculated by using adenosine receptor antagonist and agonist and dose ratio (DR) equations. METHODS: Plexus-containing guinea-pig ileum longitudinal smooth muscle preparations were made to contract intermittently by electrical field stimulation in organ baths. Schild plot regressions were constructed with 2-chloroadenosine (agonist) and 8-(p-sulfophenyl)theophylline (8-PST; antagonist). In separate experiments the reversing or enhancing effect of 8-PST and the inhibiting effect of 2-chloroadenosine (CADO) were analysed in the absence or presence of an adenosine uptake inhibitor (dilazep), and nucleoside overflow was measured by HPLC. RESULTS: Using the obtained DR, baseline adenosine concentration was calculated to 28 nm expressed as CADO activity, which increased dose dependently after addition of 10(-6) m dilazep to 150 nm (P < 0.05). HPLC measurements yielded a lower fractional increment (80%) in adenosine during dilazep, than found in the pharmacological determination (440%). CONCLUSION: Endogenous adenosine is an important modulator of intestinal neuro-effector activity, operating in the linear part of the dose-response curve. Other adenosine-like agonists might contribute to neuromodulation and the derived formulas can be used to calculate endogenous agonist activity, which is markedly affected by nucleoside uptake inhibition. The method described should be suitable for other endogenous signalling molecules in many biological systems.

a+0 (980)-resonance production in pp-->dK+K-0 reactions close to threshold.

The reaction pp-->dK+K(-)0 has been investigated at an excess energy of Q=46 MeV above the K+K(-)0 threshold with ANKE at the cooler synchrotron COSY-Jülich. From the detected coincident dK(+) pairs, about 1000 events with a missing K(-)0 were identified, corresponding to a total cross section of sigma(pp-->dK+K(-)0)=[38+/-2(stat)+/-14(syst)] nb. Invariant-mass and angular distributions have been jointly analyzed and reveal s-wave dominance between the two kaons, accompanied by a p wave between the deuteron and the kaon system. This is interpreted in terms of a(+)0 (980)-resonance production.

[Prospects of immunotropic therapy of traumatic uveitis]. / O perspektivakh immunotropnogo lecheniia travmaticheskikh uveitov.

Traditional corticosteroid and antiinflammatory therapy should be supplemented with new immunocorrective drugs in patients with traumatic uveitis and ocular subatrophy. Immunotherapy is a pathogenetically justified and perspective trend in multiple-modality treatment of patients with injuries to the organ of vision. The authors validate the use of immunocorrectors utilized in general transplantology for preventing rejection crisis. Immunostimulants or immunosuppresants can be added to treatment protocols for patients with traumatic uveitis, depending on the changes in the patient's immune status. New immunotropic drugs affecting all components of immunity are needed.

[Modern methods of medical rehabilitation in traumatic detachment of retina]. / Sovremennye metody meditsinskoi reabilitatsii pri travmaticheskoi otsloiki setchatki.

The authors analyze the efficacy of treating patients with vitreoretinal diseases using a pathogenetically-based system of comprehensive medical rehabilitation and the results of ophthalmological examination recorded and processed in a special computer case history. Prognostic analysis making use of nonparametrical statistics method distinguished highly informative signs determining the results of medical rehabilitation in traumatic detachment of the retina. Basic methods of surgical rehabilitation are supplemented with preventive YAG laser surgery. Modern scleroplastic materials are offered. The authors emphasize the significance of two staged adequate postoperative rehabilitation during the immediate postoperative period with special emphasis on the agents regulating redox processes; later YAG lasers and other stimulators can be used. Other perspective trends of research are study of electroenesis and pathogenesis of vitreoretinal proliferation for drug development.

[Clinical aspects of traumatic uveitis and causes of enucleation]. / Kliniko-immunologicheskie aspekty travmaticheskikh uveitov, prichiny énukleatsii.

The authors analyze 37 cases with grave traumatic uveitis eventuating in enucleation. Terms of enucleation after the injury, type of the injury, clinical picture of chronic uveitis, echographic and electrophysiological findings are presented. In ten patients signs of sensitization to ocular tissues were detected in various periods after the injury. Sensitization was detected by the leukocyte migration inhibition test (LMIT). The authors regard the results as a response to release of tissue antigens in the bloodflow because of impairment of the blood-eye barrier caused by the trauma. The authors claim that the results of LMIT in traumatic uveitis may be regarded as an additional, together with the clinical symptoms, criterion among indications to enucleation.

[Immunological reactions in pathogenesis of posttraumatic uveitis and eyeball subatrophy]. / Immunologicheskie reaktsii v patogeneze posttravmaticheskogo uveita i subatrofii glaznogo iabloka.

Clinical and morphological examinations of 30 eyes enucleated for relapses of traumatic uveitis and subatrophy caused by grave penetrating wounds involving a complete loss of visual function were carried out and 12 patients were tested for sensitization to tissue antigens by the leukocyte migration inhibition test. Morphological examination revealed cellular reaction in eye membranes, indicating an autoimmune process developing in response to release of the antigenic tissue substances of the eye into the bloodflow and reactive flow of immunocompetent cells towards ocular tissues because of injury to the blood-eye barrier. Detection of sensitization to tissue antigen in the patients confirms this viewpoint. The authors compare the revealed inflammatory process in the injured eye with the graft rejection reaction and find them similar.

[Clinical course of ocular injuries in patients with a history of keratotomy]. / Osobennosti klinicheskogo techeniia travm glaz u lits, perenesshikh keratotomiiu.

Fifteen patients with contusions and a history of keratotomy were observed. All the patients presented with a characteristic symptom complex: lacerated wounds of the cornea because of ruptures at the sites of incisions, rupture of the iris, prolapse of the lens and vitreous body, impairment of internal membranes. Primary surgical treatment and subsequent antiinflammatory therapy and rehabilitation measures helped preserve all the eyes and attain functional results in 50% patients.

[Characteristics of the ambulatory care of patients with posttraumatic pathology of the eye]. / Osobennosti dispanserizatsii bol'nykh s posttravmaticheskoi patologiei glaza.

The paper generalizes experience with dispensary work in the Department of eye trauma and prosthesing of the Helmholtz Institute for the period from 1985 to 1988. Analysis of 3000 patients with various posttraumatic pathologies allowed to single out dispensary groups of patients depending on localization, severity of trauma and other pecularities of posttraumatic periods; to determine optimal terms for dispensarization of these patients; and to define rehabilitative measures depending on clinical pecularities. The developed system of dispensarization of patients with posttraumatic pathology should be widely used in ophthalmologic practice because of high effectivity of the system.