When renormalizability is not sufficient: Coulomb problem for vector bosons

The Coulomb problem for vector bosons W incorporates a known difficulty; the boson falls on the center. In QED the fermion vacuum polarization produces a barrier at small distances which solves the problem. In a renormalizable SU(2) theory containing vector triplet (W^+,W^-,gamma) and a heavy fermion doublet F with mass M the W^- falls on F^+, to distances r ~ 1/M, where M can be made arbitrary large. To prevent the collapse the theory needs additional light fermions, which switch the ultraviolet behavior of the theory from the asymptotic freedom to the Landau pole. Similar situation can take place in the Standard Model. Thus, the renormalizability of a theory is not sufficient to guarantee a reasonable behavior at small distances for non-perturbative problems, such as a bound state problem.Comment: Four page

Endoscopic and surgical treatment of the Mirizzi syndrome

Academia Medicală de Studii Postuniversitare, Harkov, Ucraina, Al XII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova cu participare internațională 23-25 septembrie 2015Introducere: Sindromul Mirizzi se caracterizează prin compresia căii biliare de către colecist sau formarea unei fistule între acestea, care corespunde tipului Mirizzi I şi II (McSherry, 1984). Diagnosticul se confirmă prin ERCP. Corecţia chirurgicală este complexă şi adesea în cazurile de Mirizzi II este necesară aplicarea hepaticojejunostomiei. Scop: Evaluarea oportunităţilor tratamentului endoscopic şi chirurgical al sindromului Mirizzi pentru păstrarea pasajului bilei spre duoden. Material şi metode: Dintre 2144 pacienţi cu litiază biliară, obstrucţia căilor biliare a fost evidențiată la 328 (15,3%). Sindromul Mirizzi a fost diagnosticat în 21 (6,4%) cazuri: de tip I – la 6 (28,6%) pacienţi, de tip II – la 15 (71,4%). Rezultate: În două cazuri de Mirizzi I iniţial a fost practicat drenajul biliar transnazal, într-un caz – stentarea ductului biliar comun. Colecistectomia laparoscopică s-a efectuat la 5 pacienţi şi deschisă – la unul. La 2 din 15 (13,3%) pacienţi cu Mirizzi II s-a reuşit litotripsia, la un bolnav a fost realizată stentarea biliară. Pentru a reduce icterul în 12 cazuri a fost aplicat drenajul biliar transnazal. Ulterior, 9 pacienţi au suportat colecistectomie cu plastia defectului ductului biliar comun, la 2 bolnavi s-a efectuat colecistectomie laparoscopică cu extragerea calculilor biliari, şi într-un caz s-a practicat hepaticojejunostomia. Astfel, la 14 din 15 (93,3%) bolnavi cu Mirizzi II pasajul biliar fiziologic a fost restabilit cu succes. Mortalitatea postoperatorie a constituit 0, morbiditatea – 19% (4 pacienţi). Concluzie: Aplicarea tratamentului endoscopic şi chirurgical la pacienţii cu Mirizzi II a permis restabilirea pasajul biliar fiziologic în 93% din cazurile noastre.Introduction: The Mirizzi syndrome is characterized by compression of bile duct by gallbladder or fistula formation between them, that corresponds to the Mirizzi type I and type II (McSherry, 1984). The diagnosis confirms by ERCP. Surgical correction is complex and often needs hepaticojejunostomy in cases of Mirizzi II. Aim: Evaluate opportunities of the endoscopic and surgical treatment of Mirizzi syndrome in the preservation of bile passage to the duodenum. Material and methods: Among 2144 patients with cholelithiasis, biliary tract obstruction occurred in 328 (15.3%). Mirizzi syndrome was diagnosed in 21 (6.4%): type I – in 6 (28.6%) patients, type II – in 15 (71.4%). Results: In two cases of Mirizzi I initially transnasal biliary drainage was performed and in one – the common bile duct stenting. In 5 patients laparoscopic and in one open cholecystectomy was performed. In 2 of 15 (13.3%) patients with Mirizzi II lithotr ipsy was successful; in one bile duct stenting was performed. To reduce jaundice in 12 cases transnasal biliary drainage was introduced. Thereafter, 9 patients underwent cholecystectomy with the common bile duct defect plasty, 2 patients underwent laparoscopic cholecystolitotomy with bile duct stones extraction, and in one case hepaticojejunostomy was formed. Thus, in 14 of 15 (93.3%) of Mirizzi II physiological bile passage was successfully restored. Postoperative mortality was 0, morbidity was 19% (4 patients). Conclusion: The use of endoscopic and surgical treatment in cases of Mirizzi II allowed restoring the physiological bile passage in 93% of cases

Monopole Vector Spherical Harmonics

Eigenfunctions of total angular momentum for a charged vector field interacting with a magnetic monopole are constructed and their properties studied. In general, these eigenfunctions can be obtained by applying vector operators to the monopole spherical harmonics in a manner similar to that often used for the construction of the ordinary vector spherical harmonics. This construction fails for the harmonics with the minimum allowed angular momentum. These latter form a set of vector fields with vanishing covariant curl and covariant divergence, whose number can be determined by an index theorem.Comment: 21 pages, CU-TP-60

Flux- and volume-limited groups/clusters for the SDSS galaxies: catalogues and mass estimation

We provide flux-limited and volume-limited galaxy group and cluster catalogues, based on the spectroscopic sample of the SDSS data release 10 galaxies. We used a modified friends-of-friends (FoF) method with a variable linking length in the transverse and radial directions to identify as many realistic groups as possible. The flux-limited catalogue incorporates galaxies down to m_r = 17.77 mag. It includes 588193 galaxies and 82458 groups. The volume-limited catalogues are complete for absolute magnitudes down to M_r = -18.0, -18.5, -19.0, -19.5, -20.0, -20.5, and -21.0; the completeness is achieved within different spatial volumes, respectively. Our analysis shows that flux-limited and volume-limited group samples are well compatible to each other, especially for the larger groups/clusters. Dynamical mass estimates, based on radial velocity dispersions and group extent in the sky, are added to the extracted groups. The catalogues can be accessed via http://cosmodb.to.ee and the Strasbourg Astronomical Data Center (CDS).Comment: 16 pages, 18 figures, 2 tables, accepted for publication in A&

Topological surface state under graphene for two-dimensional spintronics in air

Spin currents which allow for a dissipationless transport of information can be generated by electric fields in semiconductor heterostructures in the presence of a Rashba-type spin-orbit coupling. The largest Rashba effects occur for electronic surface states of metals but these cannot exist but under ultrahigh vacuum conditions. Here, we reveal a giant Rashba effect ({\alpha}_R ~ 1.5E-10 eVm) on a surface state of Ir(111). We demonstrate that its spin splitting and spin polarization remain unaffected when Ir is covered with graphene. The graphene protection is, in turn, sufficient for the spin-split surface state to survive in ambient atmosphere. We discuss this result along with evidences for a topological protection of the surface state.Comment: includes supplementary informatio

Atomic clocks with suppressed blackbody radiation shift

We develop a nonstandard concept of atomic clocks where the blackbody radiation shift (BBRS) and its temperature fluctuations can be dramatically suppressed (by one to three orders of magnitude) independent of the environmental temperature. The suppression is based on the fact that in a system with two accessible clock transitions (with frequencies v1 and v2) which are exposed to the same thermal environment, there exists a "synthetic" frequency v_{syn} (v1-e12 v2) largely immune to the BBRS. As an example, it is shown that in the case of ion 171Yb+ it is possible to create a clock in which the BBRS can be suppressed to the fractional level of 10^{-18} in a broad interval near room temperature (300\pm 15 K). We also propose a realization of our method with the use of an optical frequency comb generator stabilized to both frequencies v1 and v2. Here the frequency v_{syn} is generated as one of the components of the comb spectrum and can be used as an atomic standard.Comment: 5 pages, 2 figure

Observation of Surface-Avoiding Waves: A New Class of Extended States in Periodic Media

Coherent time-domain optical experiments on GaAs-AlAs superlattices reveal the exis-tence of an unusually long-lived acoustic mode at ~ 0.6 THz, which couples weakly to the environment by evading the sample boundaries. Classical as well as quantum states that steer clear of surfaces are generally shown to occur in the spectrum of periodic struc-tures, for most boundary conditions. These surface-avoiding waves are associated with frequencies outside forbidden gaps and wavevectors in the vicinity of the center and edge of the Brillouin zone. Possible consequences for surface science and resonant cavity ap-plications are discussed.Comment: 16 pages, 3 figure

Possibilities of prophylaxis of purulent complications in patients with acute intestinal obstruction

Academia Medicală de Studii Postuniversitare, Harkov, Ucraina, Al XII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova cu participare internațională 23-25 septembrie 2015Introducere: Mortalitatea postoperatorie prin complicaţii septice acute ce survin la 50-85% dintre pacienţii cu ocluzii intestinale acute (OIA) ajunge pînă la 17-21%. Injectarea intraluminală a antibioticelor, terapia parenterală empirică cu antibiotice, cît şi intubarea intestinului urmată de lavaj nu îmbunătăţesc parametrii indicaţi mai sus. Scopul studiului: Definirea rolului antibioticilor, care reprezintă cel mai răspîndit grup, în profilaxia complicaţiilor purulente septice în OIA. Material şi metode: Au fost analizate rezultatele tratamentului a 176 pacienţi, inclusiv a 62 cazuri diagnosticate cu OIA; obturaţie – în 82 cazuri, iar în 32 cazuri cauza a fost hernia strangulată. Primul grup a inclus 81 pacienţi, 41 dintre care au beneficiat de tratament parenteral cu preparate din grupul aminoglicozidelor şi 40 – preparate din seria penicilinelor. Al doilea grup a inclus 95 pacienţi, la 48 dintre care li s-au administrat preparate din grupul fluorochinolonelor şi 47 – preparate din seria cefalosporinelor. Alegerea preparatelor antibacteriene s-a bazat pe rezultatele studiului experimental de acumulare a antibioticelor în peretele intestinal inflamat. Rezultate: Eficacitatea terapiei antibacteriene a fost estimată prin frecvenţa ritmului cardiac, temperatura corpului, timpul de restabilire a peristalticii, normalizarea indicilor clinici ai sîngelui şi urinei, caracterul şi calitatea complicaţiilor purulente. În ambele grupuri nu au fost stabilite diferenţe semnificative referitoare la temperatura corpului şi timpul de restabilire a peristalticii. Au fost atestate deosebiri semnificative între grupuri în ceea ce priveşte timpul de normalizare a frecvenţei ritmului cardiac, formula sîngelui şi rata complicaţiilor purulente. În grupul al doilea de pacienţi numărul complicaţiilor inflamatorii purulente a fost de 21%, iar în primul grup, în care pacienţilor li s-au administrat preparate aminoglicozide – 33,3%. Concluzii: Utilizarea parenterală a fluorochinolonelor şi cefalosporinelor a influenţat rezultatele experimentului, diminuînd esenţial complicaţiile purulente septice asociate cu OIA.Introduction: Post-operative mortality with acute-septic complications in patients with acute intestinal obstruction (AIO) as its reason in 50-85% cases comprises 17-21%. Intraluminal introduction of antibiotics, empirical parenteral antibiotic therapy as well as intestinal intubation with further lavage did not improve the parameters mentioned above. The aim of study: Definition of antibiotics role, the most widespread groups, in septic complications prophylaxis in AIO. Material and methods: There were analyzed the results of treatment of 176 patients, including 62 cases with diagnosed AIO of adhesive genesis, obstructive – in 82 cases and 32 cases with strangulated hernia. The first group included 81 patients, 41 – have incurred preparations with parenteral aminoglycosides and 40 – preparations with penicillin series. The second group included 95 patients, 48 of them followed preparations with fluoroquinolones and 47 – with cephalosporin. The choice of antibacterial preparations was based on the data of experimental trial on antibiotics cumulation in the wall of inflamed intestine. Results: Efficacy of antibacterial therapy was estimated considering heart rate frequency, body temperature, and terms of peristaltic restoration, normalization of blood and urine tests, character and quality of purulent complications. In the second group of patients (fluoroquinolones and cephalosporins preparations) the number of purulent inflammatory complications was 21%, but in the first group (aminoglycosides) – 33.3%. Conclusion: Parenteral indication of fluoroquinolones and cephalosporines in patients with acute intestinal obstruction influence on the results essentially decreases the number of purulent complications correlated with AIO

The origin of purulent-septic complications in the obturation ileus

Objective. To establish the origin of the purulent complications developing in obturative ileus in experiment. Materials and methods. The experiment was conducted on 24 white rats of the Wistar line, in whom obturative ileus was simulated. Results. The data about dynamical changes of the intestinal wall histostructure above the obstruction and concerning its seeding degree were obtained. In 12 h from the obstruction occurrence the destructive changes in intestinal wall, consisting of mucosal phlegmonous inflammation, occurr, while the bacterial seeding level of the intestinal wall raises from 104 CFU/g of the tissue (the initial) up to 1011 CFU/g. In 36 hours of the ileus persistence the purulent inflammation spreads on submucosal and muscular layers, and translocation of microflora into submucosal layer occurs, the level of microbial seeding of intestinal wall in these terms raises up to 1010-1011 CFU/g of the tissue. Conclusion. Phlegmonous enteritis develops in durable persistence of obturative ileus in intestinal wall, localized above the obstruction. After elimination of obturative ileus, the intestinal lumen and abdominal cavity sanation the main origin of purulent complications persists in intestinal wall above the obstruction

Six-body Light-Front Tamm-Dancoff approximation and wave functions for the massive Schwinger model

The spectrum of the massive Schwinger model in the strong coupling region is obtained by using the light-front Tamm-Dancoff (LFTD) approximation up to including six-body states. We numerically confirm that the two-meson bound state has a negligibly small six-body component. Emphasis is on the usefulness of the information about states (wave functions). It is used for identifying the three-meson bound state among the states below the three-meson threshold. We also show that the two-meson bound state is well described by the wave function of the relative motion.Comment: 19 pages, RevTeX, 7 figures are available upon request; Minor errors have been corrected; Final version to appear in Phys.Rev.