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A felnőttkori invaginatiók ritkák, klinikai megjelenésük eltér a gyerekkori formáktól. Klinikumuk igen változatos, gyakran atípusos, jellemző, hogy egy klinikai sejtés nyomán gondolni kell az invaginatio lehetőségére. A kiegészítő vizsgálatok közül kiemelkedő szerep jut a computer tomográfiának (CT), ami magas érzékenységgel és fajlagossággal képes kimutatni a béltraktus invaginatióját. Gyógyításuk az esetek legnagyobb részében sebészi, sokszor csak a műtét során lehetséges felismerni a kiváltó okot. Esetismertetésünkben egy rendkívül ritka, felnőttkori, passage-zavart okozó colo-colicus, a bal colonfelet érintő, a colon-flexura lienalis-descendens határra lokalizált invaginatio klinikai jellemzőit, diagnosztikáját és definitív megoldásaként a laparoscoposan asszisztált bal oldali haemicolectomia műtéti megoldását mutatjuk be. Munkánkban összefoglaljuk a felnőttkori invaginatiókra vonatkozó kórélettani fogalmakat, diagnosztikai lehetőségeket, a leggyakoribb kiváltó tényezőket és terápiás lehetőségeket.

Introduction: Polycystic ovary syndrome (PCOS) is a common condition in women, characterised by reproductive and metabolic dysfunction. While dietary approaches have been evaluated as a first-line treatment for patients with PCOS, there is limited evidence to support preference for a specific dietary composition. This systematic review and network meta-analysis was performed with the objective of comparing different dietary interventions in terms of positive impact. Metformin, the currently preferred treatment, was also compared., Methods: The latest systematic search was performed on the 20th of March, 2023. Eligible randomised controlled trials (RCTs) included patients with PCOS and compared the dietary approach with another intervention or a standard diet. Outcomes were expressed via anthropometric measurements and hormonal, glycemic, and lipid levels. The Bayesian method was used to perform a network meta-analysis and to calculate the surface under the cumulative ranking curve (SUCRA) values in order to rank the dietary interventions. The overall quality of the evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation system., Results: 19 RCTs were identified, comprising data from 727 patients who were variously treated with 10 types of dietary interventions and metformin. The Dietary Approaches to Stop Hypertension (DASH) diet was the most effective in reducing Homeostatic Model Assessment of Insulin Resistance (SUCRA 92.33%), fasting blood glucose (SUCRA 85.92%), fasting insulin level (SUCRA 79.73%) and triglyceride level (SUCRA 82.07%). For body mass index (BMI), the most effective intervention was the low-calorie diet (SUCRA 84.59%). For weight loss, the low-calorie diet with metformin (SUCRA 74.38%) was the most effective intervention. Metformin produced the greatest reductions in low-density lipoprotein cholesterol (SUCRA 78.08%) and total testosterone levels (SUCRA 71.28%). The low-carb diet was the most effective intervention for reducing cholesterol levels (SUCRA 69.68%), while the normal diet (SUCRA 65.69%) ranked first for increasing high-density lipoprotein cholesterol levels., Conclusion: Dietary interventions vary in their effects on metabolic parameters in women with PCOS. Based on our results, the DASH diet is the most effective dietary intervention for treating PCOS. Registration PROSPERO ID CRD42021282984., (© 2024. The Author(s).)

Background: Soluble dietary fibers are known to reduce the levels of blood glucose and lipids in patients with type 2 diabetes mellitus (type 2 diabetes). Although several different dietary fiber supplements are utilized, to our knowledge, no previous study has ranked their efficacy yet., Objectives: We performed this systematic review and network meta-analysis to rank the effects of different types of soluble dietary fibers., Methods: We performed our last systematic search on November 20, 2022. Eligible randomized controlled trials (RCTs) included adult patients with type 2 diabetes and compared the intake of soluble dietary fibers with that of another type of dietary fiber or no fiber. The outcomes were related to glycemic and lipid levels. The Bayesian method was used to perform a network meta-analysis and calculate the surface under the cumulative ranking (SUCRA) curve values to rank the interventions. The Grading of Recommendations Assessment, Development, and Evaluation system was applied to evaluate the overall quality of the evidence., Results: We identified 46 RCTs, including data from 2685 patients who received 16 types of dietary fibers as intervention. Galactomannans had the highest effect on reducing the levels of HbA1c (SUCRA: 92.33%) and fasting blood glucose (SUCRA: 85.92%). With regard to fasting insulin level, HOMA-IR, β-glucans (SUCRA: 73.45%), and psyllium (SUCRA: 96.67%) were the most effective interventions. Galactomannans were ranked first in reducing the levels of triglycerides (SUCRA: 82.77%) and LDL cholesterol (SUCRA: 86.56%). With regard to cholesterol and HDL cholesterol levels, xylo-oligosaccharides (SUCRA: 84.59%) and gum arabic (SUCRA: 89.06%) were the most effective fibers. Most comparisons had a low or moderate certainty of evidence., Conclusions: Galactomannans were the most effective dietary fiber for reducing the levels of HbA1c, fasting blood glucose, triglycerides, and LDL cholesterol in patients with type 2 diabetes. This study was registered at PROSPERO as ID CRD42021282984., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Bee pollens are potential functional food ingredients as they contain essential nutrients and a wide range of bioactive compounds. The aim of this study was to investigate the effects of enrichment with monofloral bee pollens on the nutritional properties, techno-functional parameters, sensory profile, and consumer preference of biscuits. Biscuits were prepared according to the AACC-approved method by substituting wheat flour with pollens of rapeseed (Brassica napus L.), phacelia (Phacelia tanacetifolia Benth.) and sunflower (Helianthus annuus L.) at 2%, 5% and 10% levels. The macronutrient composition of the biscuits was determined: crude protein content (Kjeldahl method), crude fat content (Soxhlet extraction), ash content (carbonization), moisture content (drying), carbohydrate content (formula). Their total phenolic content (TPC) and in vitro antioxidant capacity (FRAP, TEAC, DPPH) were determined spectrophotometrically. The colour of the biscuits was measured using a tristimulus-based instrument, and their texture was characterized by using a texture analyser. Sensory profile of biscuits was determined by qualitative descriptive analysis (QDA). The consumer acceptance and purchase intention of the biscuits were also evaluated, based on the responses of 100 consumers. Additionally, an external preference map was created to illustrate the relationship between consumer preference and the sensory profile of the biscuits, and penalty analysis was conducted to identify directions for product development. Phacelia pollen appeared to be the most effective for improving the nutritional quality of biscuits. The addition of phacelia pollen at the 10% substitution level increased the protein content and TPC of the control biscuit by 21% and 145%, respectively. Significant changes (p < 0.05) were also observed regarding the colour and texture of biscuits. The results of the QDA revealed that biscuits containing pollens of different botanical sources have heterogeneous sensory attributes. The biscuit containing sunflower pollen at the 2% substitution level was preferred the most (overall liking = 6.9 ± 1.6), and purchase intentions were also the highest for this product. Based on the results of the present study, it is recommended to use sunflower pollen for developing pollen-enriched foods in the future.

Gluten-free (GF) diets often become nutritionally imbalanced, being low in proteins and fibers and high in sugars. Preparing GF foods with improved nutritional value is therefore a key challenge. This study investigates the impact of different combinations of whey protein (11.9%), inulin (6.0%) as dietary fiber, and xylitol (27.9%) as a sweetener used in the enrichment of green- and red-lentil-based gluten-free cookies. The cookies were characterized in terms of baking loss, geometric parameters, color, texture, and sensory profile. The results showed that these functional ingredients had different impacts on the lentil cookies made of different (green/red) lentils, especially regarding the effect of fiber and xylitol on the volume (green lentil cookies enriched with fiber: 16.5 cm 3 , sweetened with xylitol: 10.9 cm 3 vs. 21.2 cm 3 for control; red lentil cookies enriched with fiber: 21.9 cm 3 , sweetened with xylitol: 21.1 cm 3 vs. 21.8 cm 3 for control) and color (e.g., b* for green lentil cookies enriched with fiber: 13.13, sweetened with xylitol: 8.15 vs. 16.24 for control; b* for red lentil cookies enriched with fiber: 26.09, sweetened with xylitol: 32.29 vs. 28.17 for control). Regarding the textural attributes, the same tendencies were observed for both lentil products, i.e., softer cookies were obtained upon xylitol and whey protein addition, while hardness increased upon inulin enrichment. Stickiness was differently influenced by the functional ingredients in the case of green and red lentil cookies, but all the xylitol-containing cookies were less crumbly than the controls. The interactions of the functional ingredients were revealed in terms of all the properties investigated. Sensory analysis showed that the addition of whey protein resulted in less intensive "lentil" and "baked" aromas (mostly for red lentil cookies), and replacement of sugar by xylitol resulted in crumblier and less hard and crunchier products. The application of different functional ingredients in the enrichment of lentil-based gluten-free cookies revealed several interactions. These findings could serve as a starting point for future research and development of functional GF products.

Monotony in a gluten-free (GF) diet can be a challenge because of a limited choice of acceptable cereal sources. This study investigates the potential of five types of differently coloured lentils in the development of GF cookies using rice flour as a reference. Raw materials (lentil flours) and cookies were characterised in terms of physicochemical parameters (e.g., crude protein content, total phenolics and flavonoids, antioxidant properties, colour, pH); additionally, geometry, baking loss and texture profile were determined for the cookies. A sensory acceptance test was also conducted to find out consumer preferences regarding rice versus different lentil cookies. Results showed that lentil cookies were superior to rice control in terms of higher crude protein (12.1−14.8 vs. 3.8 g/100 g), phenolic (136.5−342.3 vs. 61.5 mg gallic acid equivalents/100 g) and flavonoid (23.8−75.9 vs. 13.1 mg catechin equivalents/100 g) content and antioxidant capacity (0.60−1.81 vs. 0.35 mmol trolox equivalents/100 g), as well as lower hydroxymethyl-furfural content (<1 vs. 26.2 mg/kg). Consumers preferred lentil cookies to rice ones (overall liking: 6.1−7.0 vs. 5.6, significant differences for red and brown lentils), liking especially their taste (6.3−7.0 vs. 5.5). Depending on the target parameter, whether physicochemical or sensory, these lentil flours can be promising raw materials for GF bakery products.

The probiotics are extremely sensitive to various environmental factors, which imposes limitation on their health and functional effectiveness. Thus, development of delivery system for protection of viable cells while passing through different stages of the human digestion system is key factor in application of probiotic products. In our study, the effects of several polysaccharides such as alginate, κ-carrageenan, locust bean gum, gellan gum, xanthan gum and their combination with various prebiotic components (resistant starch, lactulose, lactosucrose) on encapsulation of probiotic Lactobacillus casei 01 strain were studied. Both regular and unregular beads with size distributions from 2 mm up to 5 mm were obtained. The encapsulation efficiencies varied from 64.4% up to 79%. Based on the texture's profiles, the capsules can be grouped into 5 clusters with squared Euclidean distance 3.5. Meanwhile, the starch-alginate and the lactosucrose LS55L - alginate beads were found to be the most stable and to have massive textural properties, whereas the gellan gum - xanthan gum and the chitosan coated alginate beads emerged as the softest. Encapsulation significantly improved the degree of gastric tolerance of probiotic cells even in the presence of pepsin. The INFOGEST in vitro digestion protocol was adapted to investigate the protection effects of different capsules. The highest survival (with loss rate of lower than 1 log CFU/g) was observed in the case of the cells encapsulated in starch-alginate beads. Moreover, the alginate microcapsules combined with lactosucrose LS55L also provided very promising shield for probiotics from the low pH of gastric conditions. Our findings suggest that incorporation of prebiotics into alginate-base encapsulation would be good idea in development of micro delivery systems that helps the survival of probiotics and their delivery to the target sites of action in human body., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Percolation theory dictates an intuitive picture depicting correlated regions in complex systems as densely connected clusters. While this picture might be adequate at small scales and apart from criticality, we show that highly correlated sites in complex systems can be inherently disconnected. This finding indicates a counter-intuitive organization of dynamical correlations, where functional similarity decouples from physical connectivity. We illustrate the phenomenon on the example of the disordered contact process (DCP) of infection spreading in heterogeneous systems. We apply numerical simulations and an asymptotically exact renormalization group technique (SDRG) in 1, 2 and 3 dimensional systems as well as in two-dimensional lattices with long-ranged interactions. We conclude that the critical dynamics is well captured by mostly one, highly correlated, but spatially disconnected cluster. Our findings indicate that at criticality the relevant, simultaneously infected sites typically do not directly interact with each other. Due to the similarity of the SDRG equations, our results hold also for the critical behavior of the disordered quantum Ising model, leading to quantum correlated, yet spatially disconnected, magnetic domains.

Xylo-oligosaccharides (XOS) are nondigestible oligosaccharides (NDO) which are recently authorized as novel food ingredients in European Union. Present study introduces the effect of XOS on baking quality of cookies. Color measurements proved that XOS enhance the caramelization during baking. Texture profile, geometry, and baking loss of cookies showed little changes due to XOS addition indicating that XOS are easy to incorporate into baking products. Based on sensory evaluation by expert panel, it was observed that XOS increased the "baked character" of the cookies as indicated by the increased caramel flavor, darker color, and crispier texture. XOS addition also increased the sweet taste and global taste intensity of cookies suggesting that in bakery products XOS evolve a flavor enhancer role. XOS proved to be a promising new alternative to increase dietary fiber content of cereal-based cookies., Competing Interests: The authors declare that they do not have any conflict of interest., (© 2020 The Authors. Food Science & Nutrition published by Wiley Periodicals LLC.)

We study the time dependence of the local persistence probability during a nonstationary time evolution in the disordered contact process in d=1, 2, and 3 dimensions. We present a method for calculating the persistence with the strong-disorder renormalization group (SDRG) technique, which we then apply at the critical point analytically for d=1 and numerically for d=2,3. According to the results, the average persistence decays at late times as an inverse power of the logarithm of time, with a universal dimension-dependent generalized exponent. For d=1, the distribution of sample-dependent local persistence is shown to be characterized by a universal limit distribution of effective persistence exponents. Using a phenomenological approach of rare-region effects in the active phase, we obtain a nonuniversal algebraic decay of the average persistence for d=1 and enhanced power laws for d>1. As an exception, for randomly diluted lattices, the algebraic decay remains valid for d>1, which is explained by the contribution of dangling ends. Results on the time dependence of average persistence are confirmed by Monte Carlo simulations. We also prove the equivalence of the persistence with a return probability, a valuable tool for the argumentations.

Present study introduces the previously not-described rheological properties of a nondigestible oligosaccharide: xylo-oligosaccharide which is a novel food ingredient in Europe. Significant differences were observed among viscosity of solutions of different formulas (liquid or powder) of XOS. Thickening potential of XOS in aqueous media compared to that of sucrose (Suc) or fructo-oligosaccharides strongly depends on utilization level: At low concentration, XOS proved to be weaker while at high concentration to be stronger than fructo-oligosaccharides. Differences in viscosity of XOS, FOS, and sucrose were much higher at below 60°C than at higher temperatures. Storage and loss modulii of xanthan gum gels were not influenced while those of locust bean gum were affected negatively by XOS addition. Addition of XOS at low concentrations did not decrease gelatin gel strength but increased gelatin gel stability against mechanical stress. XOS proved to have different rheological behavior from previously used oligosaccharides., Competing Interests: The authors declare that they do not have any conflict of interest., (© 2019 The Authors. Food Science & Nutrition published by Wiley Periodicals, Inc.)

Introduction: Immunosuppressive therapy used after organ transplantation represents a considerable oncological risk. Abdominal ultrasound examinations play an essential role in the oncological screening of organ transplant patients. Our aim was to study the effectiveness of the ultrasound screening protocol currently used in our clinic., Methods: Reports of screening abdominal ultrasound examinations of kidney transplant recipients were processed at the Department of Transplantation and Surgery of Semmelweis University from January 2012 to December 2015., Results: In 1478 studies, 14 patients were diagnosed with a malignant tumor, 11 of which were formed in the native shrunken kidney. The mean age for tumor diagnosis was 55.6 ± 12.6 years, and 80% of the patients diagnosed with tumor were male. On average, 7.5 ± 4.6 years passed between the transplantation and recognition of the tumor. All of the kidney tumors were diagnosed at an early stage: histologic examination of removed kidneys showed 73% pT1a- and 17% pT1b-stage tumors., Conclusion: In our study, early stage shrunken kidney cancers were outstandingly the most common post-transplant malignancies found by ultrasound screening. Annual ultrasound examinations as part of our current screening protocol allowed the detection of tumors at an early stage in kidney transplant recipients., (Copyright © 2019 Elsevier Inc. All rights reserved.)

We consider the contact process near an extended surface defect, where the local control parameter deviates from the bulk one by an amount of λ(l)-λ(∞)=Al^{-s}, with l being the distance from the surface. We concentrate on the marginal situation s=1/ν&#95;{⊥}, where ν&#95;{⊥} is the critical exponent of the spatial correlation length, and study the local critical properties of the one-dimensional model by Monte Carlo simulations. The system exhibits a rich surface critical behavior. For weaker local activation rates AA&#95;{c}, the phase transition is of mixed order: the surface order parameter is discontinuous; at the same time the temporal correlation length diverges algebraically as the critical point is approached, but with different exponents on the two sides of the transition. The mixed-order transition regime is analogous to that observed recently at a multiple junction and can be explained by the same type of scaling theory.

We have studied the phase transition of the contact process near a multiple junction of M semi-infinite chains by Monte Carlo simulations. As opposed to the continuous transitions of the translationally invariant (M=2) and semi-infinite (M=1) system, the local order parameter is found to be discontinuous for M>2. Furthermore, the temporal correlation length diverges algebraically as the critical point is approached, but with different exponents on the two sides of the transition. In the active phase, the estimate is compatible with the bulk value, while in the inactive phase it exceeds the bulk value and increases with M. The unusual local critical behavior is explained by a scaling theory with an irrelevant variable, which becomes dangerous in the inactive phase. Quenched spatial disorder is found to make the transition continuous in agreement with earlier renormalization group results.

Modeling long-range epidemic spreading in a random environment, we consider a quenched, disordered, d-dimensional contact process with infection rates decaying with distance as 1/rd+σ. We study the dynamical behavior of the model at and below the epidemic threshold by a variant of the strong-disorder renormalization-group method and by Monte Carlo simulations in one and two spatial dimensions. Starting from a single infected site, the average survival probability is found to decay as P(t)∼t-d/z up to multiplicative logarithmic corrections. Below the epidemic threshold, a Griffiths phase emerges, where the dynamical exponent z varies continuously with the control parameter and tends to zc=d+σ as the threshold is approached. At the threshold, the spatial extension of the infected cluster (in surviving trials) is found to grow as R(t)∼t1/zc with a multiplicative logarithmic correction and the average number of infected sites in surviving trials is found to increase as Ns(t)∼(lnt)χ with χ=2 in one dimension.

We study the distribution of dynamical quantities in various one-dimensional disordered models, the critical behavior of which is described by an infinite randomness fixed point. In the disordered contact process, the survival probability P(t) is found to show multiscaling in the critical point, meaning that P(t)=t-δ, where the (environment and time-dependent) exponent δ has a universal limit distribution when t→∞. The limit distribution is determined by the strong disorder renormalization group method analytically in the end point of a semi-infinite lattice, where it is found to be exponential, while, in the infinite system, conjectures on its limiting behaviors for small and large δ, which are based on numerical results, are formulated. By the same method, the survival probability in the problem of random walks in random environments is also shown to exhibit multiscaling with an exponential limit distribution. In addition to this, the (imaginary-time) spin-spin autocorrelation function of the random transverse-field Ising chain is found to have a form similar to that of survival probability of the contact process at the level of the renormalization approach. Consequently, a relationship between the corresponding limit distributions in the two problems can be established. Finally, the distribution of the spontaneous magnetization in this model is also discussed.

This study is related to the accumulation of Cd(2+), its effects on oxidative stress biomarkers and its role in macromolecule damage in liver and kidney of common carp. We present evidence of an increased ratio of reduced to oxidized glutathione (GSH/GSSG) in both organs after 10 mg/L Cd(2+) exposure, with different underlying biological mechanisms and consequences. In the liver, the expressions and/or activities of superoxide dismutase, catalase, glutathione reductase and glutathione peroxidase increased to cope with the Cd(2+)-generated toxic effects during the first 48 h of treatment. In contrast, none of these selected antioxidant markers was significantly altered in the kidney, whereas the expression of glutathione synthetase was upregulated. These results suggest that the major defense mechanism provoked by Cd(2+) exposure involves the regeneration of GSH in the liver, while its de novo synthesis predominates in the kidney. High levels of accumulation of Cd(2+) and peroxynitrite anion (ONOO(-)) were detected in the kidney; the major consequences of ONOO(-) toxicity were enhanced lipid peroxidation and GSH depletion. The accumulation of ONOO(-) in the kidney suggests intensive production of NO and the development of nitrosative stress. In the liver the level of hydrogen peroxide was elevated., (© 2013.)

An asymmetric variant of the contact process where the activity spreads with different and independent random rates to the left and to the right is introduced. A real space renormalization scheme is formulated for the model by means of which it is shown that the local asymmetry of spreading is irrelevant on large scales if the model is globally (statistically) symmetric. Otherwise, in the presence of a global bias in either direction, the renormalization method predicts two distinct phase transitions, which are related to the spreading of activity in and against the direction of the bias. The latter is found to be described by an infinite randomness fixed point while the former is not.

Networks and dynamical processes occurring on them have become a paradigmatic representation of complex systems. Studying the role of quenched disorder, both intrinsic to nodes and topological, is a key challenge. With this in mind, here we analyze the contact process (i.e., the simplest model for propagation phenomena) with node-dependent infection rates (i.e., intrinsic quenched disorder) on complex networks. We find Griffiths phases and other rare-region effects, leading rather generically to anomalously slow (algebraic, logarithmic, etc.) relaxation, on Erdős-Rényi networks. We predict similar effects to exist for other topologies as long as a nonvanishing percolation threshold exists. More strikingly, we find that Griffiths phases can also emerge--even with constant epidemic rates--as a consequence of mere topological heterogeneity. In particular, we find Griffiths phases in finite-dimensional networks as, for instance, a family of generalized small-world networks. These results have a broad spectrum of implications for propagation phenomena and other dynamical processes on networks, and are relevant for the analysis of both models and empirical data.

Heat shock proteins are chaperones that play a pivotal role in controling multiple regulatory pathways such as stress defense, hormone signaling, cell cycle control, cell proliferation and differentiation, and apoptosis. In this study, the expression patterns of four well-known heat shock genes (hsp70, hsc70-1, hsc70-2 and hsp90α) were characterized in the skin, spleen and blood cells of the common carp, under unstressed conditions and after Cd2+ treatment or hypothermia. The examined genes were expressed in a tissue-specific manner: hsc70-2 was expressed constitutively, and was at best only slightly inducible; hsp90α exhibited a high basic expression in all three tissues, whereas hsc70-1 did so only in the blood cells, the expression of hsp70 proved to be below the level of detection in unstressed fish. Cold shock induced the expression of hsp genes in the spleen (hsp90α) and blood cells (hsp70, hsc70-1 and hsp90α), while Cd2+ treatment has no effect on the expression pattern. The highest inducibilities were detected in the skin: for hsp70 an induction of at least 20-fold after cadmium exposure, for hsc70-1 of at least 30-fold and for hsp90α of 3-fold after hypothermia.

The problem of random walk is considered in one dimension in the simultaneous presence of a quenched random force field and long-range connections, the probability of which decays with the distance algebraically as p(l)≃βl(-s). The dynamics are studied mainly by a numerical strong disorder renormalization group method. According to the results, for s>2 the long-range connections are irrelevant, and the mean-square displacement increases as ∼(lnt)(2/ψ) with the barrier exponent ψ=1/2, which is known in one-dimensional random environments. For s<2, instead, the quenched disorder is found to be irrelevant, and the dynamical exponent is z=1 like in a homogeneous environment. At the critical point, s=2, the interplay between quenched disorder and long-range connections results in activated scaling, however, with a nontrivial barrier exponent ψ(β), which decays continuously with β but is independent of the form of the quenched disorder. Upper and lower bounds on ψ(β) are established, and numerical estimates are given for various values of β. Besides random walks, accurate numerical estimates of the graph dimension and the resistance exponent are given for various values of β at s=2., (© 2012 American Physical Society)

Quenched disorder is known to play a relevant role in dynamical processes and phase transitions. Its effects on the dynamics of complex networks have hardly been studied. Aimed at filling this gap, we analyze the contact process, i.e., the simplest propagation model, with quenched disorder on complex networks. We find Griffiths phases and other rare-region effects, leading rather generically to anomalously slow (algebraic, logarithmic, …) relaxation, on Erdos-Rényi networks. Similar effects are predicted to exist for other topologies with a finite percolation threshold. More surprisingly, we find that Griffiths phases can also emerge in the absence of quenched disorder, as a consequence of topological heterogeneity in networks with finite topological dimension. These results have a broad spectrum of implications for propagation phenomena and other dynamical processes on networks.

We present simulation results for the contact process on regular cubic networks that are composed of a one-dimensional lattice and a set of long edges with unbounded length. Networks with different sets of long edges are considered that are characterized by different shortest-path dimensions and random-walk dimensions. We provide numerical evidence that an absorbing phase transition occurs at some finite value of the infection rate and the corresponding dynamical critical exponents depend on the underlying network. Furthermore, the time-dependent quantities exhibit log-periodic oscillations in agreement with the discrete scale invariance of the networks. In case of spreading from an initial active seed, the critical exponents are found to depend on the location of the initial seed and break the hyperscaling law of the directed percolation universality class due to the inhomogeneity of the networks. However, if the cluster-spreading quantities are averaged over initial sites, the hyperscaling law is restored.

A class of cubic networks composed of a regular one-dimensional lattice and a set of long-range links is introduced. Networks parametrized by a positive integer k are constructed by starting from a one-dimensional lattice and iteratively connecting each site of degree 2 with a kth neighboring site of degree 2. Specifying the way pairs of sites to be connected are selected, various random and regular networks are defined, all of which have a power-law edge-length distribution of the form P&#95;{>}(l) approximately l;{-s} with the marginal exponent s=1 . In all these networks, lengths of shortest paths grow as a power of the distance and random walk is superdiffusive. Applying a renormalization group method, the corresponding shortest-path dimensions and random-walk dimensions are calculated exactly for k=1 networks and for k=2 regular networks; in other cases, they are estimated by numerical methods. Although, s=1 holds for all representatives of this class, the above quantities are found to depend on the details of the structure of networks controlled by k and other parameters.

We study a system composed of two parallel totally asymmetric simple exclusion processes with open boundaries, where the particles move in the two lanes in opposite directions and are allowed to jump to the other lane with rates inversely proportional to the length of the system. Stationary density profiles are determined and the phase diagram of the model is constructed in the hydrodynamic limit, by solving the differential equations describing the steady state of the system, analytically for vanishing total current and numerically for nonzero total current. The system possesses phases with a localized shock in the density profile in one of the lanes, similarly to exclusion processes endowed with nonconserving kinetics in the bulk. Besides, the system undergoes a discontinuous phase transition, where coherently moving delocalized shocks emerge in both lanes and the fluctuation of the global density is described by an unbiased random walk. This phenomenon is analogous to the phase coexistence observed at the coexistence line of the totally asymmetric simple exclusion process, however, as a consequence of the interaction between lanes, the density profiles are deformed and in the case of asymmetric lane change, the motion of the shocks is confined to a limited domain.

We study the stationary properties as well as the nonstationary dynamics of the one-dimensional partially asymmetric exclusion process with position-dependent random hop rates. Relating the hop rates to an energy landscape the stationary current J is determined by the largest barrier in a finite system of L sites and the corresponding waiting time tau approximately J{-1} is related to the waiting time of a single random walker, tau&#95;{rw} , as tau approximately tau&#95;{rw}{1/2} . The current is found to vanish as J approximately L{-z2} , where z is the dynamical exponent of the biased single-particle Sinai walk. Typical stationary states are phase separated: At the largest barrier almost all particles queue at one side and almost all holes are at the other side. The high-density (low-density) region is divided into approximately L{1/2} connected parts of particles (holes) which are separated by islands of holes (particles) located at the subleading barriers (valleys). We also study nonstationary processes of the system, like coarsening and invasion. Finally we discuss some related models, where particles of larger size or multiple occupation of lattice sites is considered.