The Flux-Line Lattice in Superconductors

Magnetic flux can penetrate a type-II superconductor in form of Abrikosov vortices. These tend to arrange in a triangular flux-line lattice (FLL) which is more or less perturbed by material inhomogeneities that pin the flux lines, and in high-$T_c$ supercon- ductors (HTSC's) also by thermal fluctuations. Many properties of the FLL are well described by the phenomenological Ginzburg-Landau theory or by the electromagnetic London theory, which treats the vortex core as a singularity. In Nb alloys and HTSC's the FLL is very soft mainly because of the large magnetic penetration depth: The shear modulus of the FLL is thus small and the tilt modulus is dispersive and becomes very small for short distortion wavelength. This softness of the FLL is enhanced further by the pronounced anisotropy and layered structure of HTSC's, which strongly increases the penetration depth for currents along the c-axis of these uniaxial crystals and may even cause a decoupling of two-dimensional vortex lattices in the Cu-O layers. Thermal fluctuations and softening may melt the FLL and cause thermally activated depinning of the flux lines or of the 2D pancake vortices in the layers. Various phase transitions are predicted for the FLL in layered HTSC's. The linear and nonlinear magnetic response of HTSC's gives rise to interesting effects which strongly depend on the geometry of the experiment.Comment: Review paper for Rep.Prog.Phys., 124 narrow pages. The 30 figures do not exist as postscript file

Philosophy of law in the Soviet Union and the people’s democracies

The fate of Marxism in the Soviet Union and the people’s democracies as the former’s extension owing to post-WWII occupation was from the beginning sealed by Bolshevism, that is, the politico-ideological domination and use of the scholarly domain as well, made to self-close in a merely justificatory role. There may have been attempts at opening, even if only conceivable within—i.e. preserving at the same time—this framework function. In the present conspectus, the limiting positions are occupied by the Soviet Union and the German Democratic Republic, completed by after-1968 Czechoslovakia, as well as Yugoslavia and pre-1968 Czechoslovakia, representing the substitute-to-religion dogmatic side, exclusively politically motivated in the former and subordinated to a humanising tendency in the latter case, on the one hand, and Poland, dedicated to a purely analytical approach, in which Marxism has simply no relevance, on the other. Hungary, treated in an earlier paper by the author, was in-between, taking Marxism seriously but mostly as a methodology, and thereby able to foster live debates. All that notwithstanding, there has been quite a few progressive moves also in Romania and Bulgaria in this specific academic field. Turning topoi of the discussions were, chronologically but recurrent transubstantiatedly, the exclusivity of Vyshinsky’s socialist normativism, the consequences ensuing from the law’s superstructural nature, the discontinuity vs. continuity of law in historical development, and, in the background, the dilemma of the ontological/epistemological understanding of Marxism, the latter standing for a rigid Leninist reducibility of law to its material substratum as the product of sheer reflection, and the former enabling to develop the law’s relative autonomy as in Lukács’ posthumous ontology. On the final analysis, all these forced paths made a whole region’s efforts to be belated as compared to international developments, the fact notwithstanding those outstanding achievements were born especially on the fields of legal ontology and sociology, as well as the legal methodology and particularly that of the comparison of laws

Antibiotic Resistance Patterns of Uropathogens Causing Urinary Tract Infections in Children with Congenital Anomalies of Kidney and Urinary Tract

Background: Urinary tract infections (UTI) are common in children worldwide. Congenital anomalies of kidney and urinary tract (CAKUT) increase the risk of UTI and consequently antibiotic resistance. Antibiotic resistance represents an important public health issue worldwide. We aimed to evaluate the local trend in terms of bacterial uropathogen resistance in the western part of Romania in children with CAKUT and UTI. Methods: 252 children with CAKUT were admitted to our hospital over a five-year period. Of them, 91 developed at least one UTI episode, with a total number of 260 positive urine cultures. We collected data about age at diagnosis of CAKUT, sex, origin environment, type and side of CAKUT, number of UTIs, type of uropathogen, and uropathogens antibiotic resistance. Results: Distribution of uropathogens was Escherichia coli (38.84%), Klebsiella spp. (21.15%), Enterococcus spp. (15.76%), Proteus spp. (8.07%), Pseudomonas spp. (8.07%), Enterobacter spp. (2.3%), other Gram-negative bacteria (2.3%), and other Gram-positive bacteria (3.45%). High antibiotic resistance was detected for ampicillin, amoxicillin, and second-generation cephalosporins. Escherichia coli presented high resistance for cefepime and ceftriaxone. Pseudomonas spp. remained susceptible to amikacin, quinolones, and colistin. Vancomycin, teicoplanin, linezolid, and piperacillin/tazobactam remained effective in treating Gram-positive UTI. Conclusions: High antibiotic resistance was identified for frequently used antibiotics. Lower antibiotic resistance was observed for some broad-spectrum antibiotics. Understanding uropathogens’ antibiotic resistance is important in creating treatment recommendations, based on international guidelines, local resistance patterns, and patient particularities

Muon spin relaxation in Re-substituted HgA₂Ca_n-1Cu_nO_2n+2+x (A=Sr, Ga; n=2,3) superconductors

One of the fundamental features of the superconducting cuprates is their layered structure. They are made of superconducting CuO2 planes—or blocks of planes—separated by other layers which act as charge reservoirs and, depending on their atomic constituents and thickness, can be insulating, metallic, or even superconducting. This anisotropic structure is thought to be at the origin of most of the unusual superconducting properties of these compounds, as, for instance, the high critical temperature Tc and the low irreversibility line..

Factors Influencing Consumer Dietary Health Preventative Behaviours

Background: The deterioration of the health status of the Romanian population during the economic transition from a centrally planned to a free market economy has been linked to lifestyles factors ( e. g. diet) regarded as a main determinants of the disparity in life expectancy between Eastern and Western Europe. Reforms in the health care system in this transition economy aim to focus on preventive action. The purpose of this study was to identify the factors that impact on the individual decision to engage in Dietary Health Preventive Behaviour ( DHPB) and investigate their influence in the context of an adapted health cognition model