bluuebunny/crossref_metadata_2025 huggingface dataset:
Emerging Technologies for the Diagnosis of Perihilar Cholangiocarcinoma
Authors: Ilyas Sumera I , Eaton John , Yang Ju Dong , Chandrasekhara Vinay , Gores Gregory J.
Published: June 2018

The diagnosis of malignant biliary strictures remains problematic, especially in the perihilar region and in primary sclerosing cholangitis (PSC). Conventional cytology obtained during endoscopic retrograde cholangiography (ERC)-guided brushings of biliary strictures is suboptimal due to limited sensitivity, albeit it remains the gold standard with a high specificity. Emerging technologies are being developed and validated to address this pressing unmet patient need. Such technologies include enhanced visualization of the biliary tree by cholangioscopy, intraductal ultrasound, and confocal laser endomicroscopy. Conventional cytology can be aided by employing complementary and advanced cytologic techniques such as fluorescent in situ hybridization (FISH), and this technique should be widely adapted. Interrogation of bile and serum by examining extracellular vesicle number and cargo, and exploiting next-generation sequencing and proteomic technologies, is also being explored. Examination of circulating cell-free deoxyribonucleic acid (cfDNA) for differentially methylated regions is a promising test which is being rigorously validated. The special expertise required for these analyses has to date hampered their validation and adaptation. Herein, we will review these emerging technologies to inform the reader of the progress made and encourage further studies, as well as adaptation of validated approaches.
The Thromboplastinogen activity time (TAT) Test
Authors: Quick Armand J.
Published: June 2018

The thromboplastinogen activity time (TAT) test is described. The method is based on the finding that rabbit brain extract heated to 60° C loses its holo-thromboplastin activity but retains the properties of platelet extract and can, therefore, be used as a substitute for platelet extract in the prothrombin consumption test. The application of the test to differentiate hemophilia from thrombocytopenia and thrombasthenia is illustrated by case reports. The use of the test for the differential diagnosis of hemophilia and PTC deficiency is outlined and examples of its application given.
Platelet cothromboplastin: a platelet factor(s) related to the blood clotting mechanisms
Authors: Lee Pyung-Hee , Johnson Shirley A. , Seegers Walter H.
Published: June 2018

Bovine Platelets contain a factor(s) that greatly enhances the capacity of lung extract thromboplastin to conver purified prothrombin to biothrombin. It also may function with Russell’s viper venom in the activation of prothrombin The activity is destroyed below pH 4 or above pH 11 or at temperatures above 52° C. Concentrates of the activity have been obtained in a fraction of platelets that consists predominately of carbohydrate and protein.
The Challenge of cerebral vascular diseases
Authors: Wright Irving S.
Published: June 2018

Cerebral vascular diseases are of major importance but unfortunately their study has been greatly neglected until recent years.

There are serious gaps in our basic knowledge regarding their pathogenesis and therapy. The differential diagnoses of thrombosis, embolism, hemorrhage and tumor have been outlined. Intermittent neurological signs due to cerebral vascular diseases have been discussed. The distinctions between intermittent and permanent occlusion of the basilar artery, carotid artery and cerebral artery have been elaborated.

Long term anticoagulant therapy is of value in the prevention of recurrent thromboses and emboli wherever they may occur in the carotid, basilar or cerebral arterial tree.

Anticoagulants are indicated as a prophylactic measure before mitral com-misurotomy when the patient has had previous emboli or when his heart is in atrial fibrillation. They should also be continued after this surgery. The question whether the patient should be carried through the operation at therapeutic levels of anticoagulant therapy is at present under study in several clinics, but the evidence suggests that this is feasible and improves the chances of avoiding emboli.

It appears logical to use anticoagulants in the treatment of acute episodes of thrombosis and embolism but this is under further study at present.

Other forms of therapy including the stellate sympathetic ganglion block, and the inhalation of CO2 have been evaluated. Thus far the evidence suggests that while the inhalation of CO2 may be helpful theoretically the others are of doubtful value.

This is a challenging field which should attract the attention of many workers during the next several decades.
Versuche zur chemischen Identifikation und Synthese von Gerinnungsfaktoren
Authors: Hecht E , Shapiro D
Published: June 2018

1. Mit Hilfe einer ausführlichen Einleitung wurde versucht, die Grundlage zum müheloseren Verständnis der vorliegenden Untersuchung zu schaffen.

2. Die Resultate einer Studie mit fünf verschiedenen synthetischen Kephalinen waren:

a) Die synthetischen Kephaline sind im Gegensatz zu den lipoiden Aktivatoren und dem von Paul s sen untersuchten Lipoidextrakt aus den Blutplättchen gegenüber Hühnerplasma und menschlichem Plasma inaktiv.

b) Ebensowenig können die Kephaline die Rolle der sub a) genannten Substanzen im Rahmen der Sphingosinreaktionen übernehmen.

c) Die Kephaline sind nicht imstand im Thrombokinasebildungstest die Funktion der Thrombozyten zu erfüllen, wozu die Lipoidextrakte aus denselben und ebenso die lipoiden Aktivatoren befähigt sind.

d) Alle synthetischen Kephaline geben anläßlich ihrer papierchromatographi-schen Untersuchung andere Ninhydrin-positive Reaktionen wie Lipoidextrakte aus den Blutplättchen und die lipoiden Aktivatoren.

3. Die sub 2 genannten Befunde werden als weitere Argumente gegen die Auffassung von der Identität des lipoiden Aktivators mit dem Kephalin klassischer Prägung gedeutet.

4. Die typischen Reaktionen des aus physiologischem Material isolierten Inhibitors Sphingosin werden in noch stärkerem Maß von der synthetisch bereiteten Verbindung gegeben.

5. Die Untersuchung von 8 synthetischen Derivaten, Isomeren und Homologen des Sphingosins zeigte, daß zum Erhalt der maximalen Sphingosinreaktionen sowohl die Doppelbindung als auch die freien OH- und NH2-Gruppen erforderlich sind.
The Haemostatic Balance))
Authors: Astrup Tage
Published: June 2018

The roles played by the blood clotting system and by fibrinolysis in the haemostatic balance are discussed. The significance of the tissue thromboplastin and the tissue activator of plasminogen for local haemostasis is emphasized, and their relation to anticoagulant therapy considered. Problems specific for coronary thrombosis, cerebral thrombosis and cerebral haemorrhage have been mentioned.
Long Term Treatment with Anticoagulants in Coronary Artery Disease
Authors: Owren P. A
Published: June 2018

347 patients with angina pectoris and 222 patients who had survived an attack of myocardial infarction for at least 8 weeks have been under long-term treatment with dicumarol or phenylindanedione. The annual mortality-rate was reduced to 5% in both groups. Patients with angina pectoris show improvement in 47.7% of the cases, if the disease is not older than 1 year before the start of treatment. Improvement was found in only 25% of the cases when the disease was older than 4 years. It was clearly evidenced that anticoagulant treatment of angina pectoris is only useful when the disease is not older than 2 to 3 years before starting treatment.
Chronic Antithrombinaemia (Antithrombin V) with Haemorrhagic Diathesis in a Case of Rheumatoid Arthritis with Hypergammaglobulinaemia
Authors: Loeliger A , Hers J. F. Ph
Published: June 2018

A report is represented on a 44-year-old patient suffering, since 1938, from very slowly progressive rheumatoid arthritis. Haemorrhagic manifestations have been seen since 1951 (large cutaneous and muscular haemorrhages, microhaematuria and macrohaematuria, possibly also articular haemorrhages). In addition to an extremely marked increase in γ-globulins to values above 8 g/100 ml (γ-globulins with a normal sedimentation constant S 7) a circulating anticoagulant was demonstrable, which is held responsible for the marked increase in clotting time, “prothrombin” time and thrombin time. The hypothesis is forwarded that this is a physiological anticoagulant showing a marked increase. Since it is different from the four antithrombins described by Seegers it is referred to as antithrombin-V. Antithrombin-V occurs both in the plasma and in the serum and appears to be bound to the (ß)γ-fraction. It is a thrombin inhibitor which, unlike antithrombin-II, has no direct effect on thromboplastin and thrombin formation. Antithrombin-V cannot be neutralized by protamine sulphate; it is heat-stable, not dialysable and not adsorbed onto BaSO4. Thrombelastography made it possible clearly to demonstrate that an increase in antithrombin-V is associated with a marked increase in clotting time but causes no pathological course of clot formation.

Therapeutic results obtained with ACTH and cortisone are favourable: the activity of antithrombin-V decreases parallel with a decrease in γ-globulin values, and the clotting time is normalized. The patient has received, during the past 16 months, oral cortisone treatment (25 mg thrice daily), and is at present free of complaints, although clinical and laboratory findings show a gradual increase in symptoms respectively γ-globulin values with a slight increase in clotting time.

The possible significance of the antithrombin-V activity in the protection against thrombo-embolism is briefly mentioned.
Probleme der Antikoagulantienbehandlung
Authors: Deutsch E , Benda L , Zischka W
Published: June 2018

Die Antikoagulantien beeinflussen neben der Blutgerinnung auch die Zellteilung, das Wachstum von Fibroblastenkulturen und die Bindegewebsbildung. Da diese Vorgänge die Heilung bei Myokardinfarkten ungünstig beeinflussen könnten, wurde das histologische Bild der Abheilungsvorgänge experimenteller Myokardinfarkte bei Hunden mit und ohne Behandlung mit Marcoumar oder Heparin verfolgt. Es zeigte sich, daß bei den Kontrolltieren nach 14 Tagen bereits ein junges, faserreiches Bindegewebe im Bereich des Infarktes nachweisbar ist, während unter Marcoumar noch Nekrosen, reichlich Fibroblasten, aber noch keine Bindegewebsfasern nachgewiesen werden können. Erst nach 4 Wochen ist die Bindegewebsbildung so weit fortgeschritten wie bei den Kontrolltieren nach 14 Tagen. Unter Heparin ist die Proliferation der Fibroblasten besonders ausgeprägt. Die Konsequenzen für die Antikoagulantienbehandlung der Myokardinfarkte werden diskutiert.
Augentrauma im Kindesalter
Authors: Meier P.
Published: June 2018

Unglücklicherweise erleiden immer wieder Kinder Augenunfälle. Wir können dabei zwischen direkten und indirekten Traumata unterscheiden und klassifizieren direkte Augenunfälle in offene und geschlossene Bulbusverletzungen, zu letzteren gehören Verätzungen und Verbrennungen.

Kinder verunfallen vorzugsweise zu Hause beim unbeaufsichtigten Spielen. Wichtig ist die Kenntnis des jeweiligen Unfallherganges. Oftmals haben wir jedoch keine oder auch falsche Informationen, manchmal ist die Glaubwürdigkeit der Angaben fraglich und die Kinder sind nicht kooperativ. Primäres Ziel der Untersuchung sollte eine klare Diagnose der Augenverletzung sein, damit eine optimale Versorgung ohne Verzögerung eingeleitet werden kann. Dazu ist bei der Mehrzahl der kindlichen Augenverletzungen eine gute Zusammenarbeit zwischen Pädiatern, Augenärzten, Radiologen und anderen Fachgebieten notwendig.

Eine notfallmäßige Intervention ist bei Verätzungen und Verbrennungen der Augen erforderlich, wichtigste Sofortmaßnahme ist ein unverzügliches intensives Spülen der Augenoberfläche, da jede Verzögerung eine Verschlechterung der Prognose bedeutet.
Diagnose „Konnatale Hypothyreose” – früh stellen und dranbleiben!
Authors: Kiess W. , Pfäffle R. , Körner A. , Stoltze A.
Published: June 2018

Schwere mentale und körperliche Retardierung sind bekannte Folgen einer nicht behandelten primären Hypothyreose. Seit Einführung des erweiterten Neugeborenenscreenings in Deutschland sehen wir das gesamte Ausmaß dieser Folgeerscheinungen erfreulicherweise kaum noch. Wir berichten hier über ein Mädchen, welches trotz gestellter Diagnose im Neugeborenenscreening und umgehend eingeleiteter Behandlung mit initialer Normalisierung der Serumparameter unter extremem Kleinwuchs sowie weiteren Auswirkungen einer manifesten Hypothyreose litt.
Prepectoral implant placement in plastic-reconstructive breast surgery – a contribution to the discussion
Authors: Paepke Stefan , Ohlinger Ralf , Klein Evelyn , Thill Marc
Published: June 2018

Implant-based breast reconstruction has gained a high and increasing level of importance both nationally and internationally in recent years and covers a wide spectrum of reconstruction techniques. The standard procedure in nipple-sparing subcutaneous mastectomies is currently performed by placing the implant into a subpectoral pocket beneath the pectoralis muscle. The use of implant-based reconstructive techniques with the need for internal support to reconstruct the inframammary fold, to cover the implant at the lower pole and to provide a stable but flexible implant position has become relevant and led to the introduction of heterologous materials such as acellular dermal matrices and synthetic meshes. Although the safety and aesthetics of this approach have produced good results, prepectoral techniques add a whole new dimension with the development of the next generation of acellular dermal matrices and, especially, titanised implant pockets created specifically for prepectoral implant placement 1 have brought about a renaissance in muscle-sparing reconstructive techniques. These preserve the natural anatomy, thereby avoiding the adverse effects associated with submuscular reconstruction, including preservation of full shoulder function, minimising postoperative pain and the risk of bleeding and haematoma, and animation deformities such as “jumping breast phenomenon”. A new method of implant-based breast reconstruction is therefore available and must be analysed regarding indications and benefits.
EUS-FNA versus ERCP for tissue diagnosis of suspect malignant biliary strictures: a prospective comparative study
Authors: Moura Diogo , de Moura Eduardo , Matuguma Sergio , dos Santos Marcos , Moura Eduardo , Baracat Felipe , Artifon Everson , Cheng Spencer , Bernardo Wanderley , Chacon Danielle , Tanigawa Ryan , Jukemura José
Published: June 2018

Background and study aims Biliary strictures are frequently a challenging clinical scenario and the anatomopathological diagnosis is essential in the therapeutic management, whether for curative or palliative purposes. The acquisition of specimens is necessary since many benign diseases mimic biliopancreatic neoplasms. Endscopic retrograde cholangiopancreatography (ERCP) is the traditionally used method despite the low sensitivity of biliary brush cytology and forceps biopsy. On the other hand, several studies reported good accuracy rates using endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). The aim of this prospective study was to compare, the accuracy of EUS-FNA and ERCP for tissue sampling of biliary strictures.

Patients and methods After performing the sample size calculation, 50 consecutive patients with indeterminate biliary strictures were included to undergo ERCP and EUS on the same sedation.The gold-standard was surgery or 6 months’ follow-up. Evaluation of the diagnostic indices (sensitivity, specificity, positive and negative predictive value, positive and negative likelihood ratio), concordance and adverse events among the methods were performed. Also, subtype analyses of the techniques, anatomical localization and size of the lesion were included.

Results The final diagnoses reported in 50 patients were 47 malignant, 1 suspicious and 2 benign lesions. 31 lesions were extraductal and 19 intraductal, 35 were distal and 15 proximal strictures. In the intention-to-treat analysis, the sensitivity and accuracy of EUS-FNA were superior than ERCP tissue sampling (93,8 %, 94 % vs. 60,4 %, 62 %, respectively) (P = 0.034), with similar adverse events. There was no concordance between the methods and combining both methods improved the sensitivity and accuracy for 97.9 % and 98 %, respectively. In the subtype analyses, the EUS-FNA was superior, with a higher accuracy than ERCP tissue sampling in evaluating extraductal lesions (100 % vs. 54.8 %, P = 0.019) and in those larger than 1.5 cm (95.8 % vs. 61.9 %, P = 0.031), but were similar in evaluating intraductal lesions and lesions smaller than 1.5 cm. There was no significant difference between the methods in the analyzes of proximal, distal and pancreatic lesions.

Conclusion EUS-FNA is better than ERCP with brush cytology and intraductal forceps biopsy in diagnosing malignant biliary strictures, mainly in the assessment of extraductal lesions and in those larger than 1.5 cm. Combining ERCP with tissue sampling and EUS-FNA is feasible, the techniques have similar complication rates, and the combination greatly improves diagnostic accuracy.
Myomembolisation
Authors: Neumahr Tobias , Göß Simon
Published: June 2018

Minimal-invasive Therapien nehmen in der Medizin einen immer größeren Stellenwert ein. Ein Fachbereich der in den letzten Jahren immer mehr in den Vordergrund rückt, ist die interventionelle Radiologie. Mit ihr ist es möglich, innere Blutungsquellen durch das Einbringen von Embolisaten zu stoppen. Mit dem gleichen Prinzip wird Tumoren die Blutversorgung abgeschnitten. Auf dieser Grundidee baut auch die Myomembolisation auf.
Face and construct validity of a novel mechanical ERCP simulator
Authors: van der Wiel Sophia , Koch Arjun , Bruno Marco
Published: June 2018

Background and study aims Simulation-based training has become an important pillar in competence-based medicine. However, limited data are available on use of simulators in training for endoscopic retrograde cholangiopancreatography (ERCP). We aimed to determine the face and construct validity of the Boškoski-Costamagna mechanical ERCP Trainer, and to assess its didactic value, as judged by experts.

Methods Participants were divided into four groups based on ERCP lifetime experience: novices, intermediate, experienced, and experts. Participants performed several standardized assignments on the simulator. Outcome parameters included times to complete the procedure, ability to cannulate both ducts, number of attempts to cannulate the common bile duct and pancreatic duct, number of inadvertent pancreatic duct cannulations, successful stent placement, and successful stone extraction. All experts filled out a questionnaire on the simulator’s realism and didactic value.

Results Novices (n = 11) completed the total procedure in 21:09 (min:sec), intermediates (n = 5) in 10:58, experienced (n = 8) in 06:42 and experts (n = 22) in 06:05. Experts were significantly faster than novices (Kruskal-Wallis test P < 0.000). Experts rated the realism of the simulator 7.12 on a 10-point Likert scale. The simulator’s potential as a tool for training novices was rated 3.91 on a four-point Likert scale, and there was a high agreement among experts to include the simulator in the training of novice endoscopists (3.86 on a four-point Likert scale).

Conclusions The novel Boškoski-Costamagna ERCP simulator demonstrates good face and construct validity. ERCP experts highly agree on the didactic value and added value of this simulator in the training curriculum for novice endoscopists.
Motivations and Mental Models Associated with Smallholder Farmers’ Adoption of Improved Agricultural Technology: Evidence from Use of Quality Seed Potato in Kenya
Authors: Okello Julius , Zhou Yuan , Barker Ian , Schulte-Geldermann Elmar
Published: June 2018

Potato is a major food staple that makes a significant contribution to food security, having potential to smooth the volatility in food prices resulting from recent episodes of global food price increases. Despite its importance, most potato growers continue to use poor-quality seed, normally obtained from local/community sources. This study uses means-end chain theory to examine the drivers of use of quality seed potato, and the mental models associated with quality seed potato use. It finds that the decision to purchase and use quality seed is driven by deep-seated life goals that farmers pursue, and that profit-making is merely a means to these end/life goals. It further finds that the structure of mental models differs by the gender of the adopter and between adopters and nonadopters. The study concludes that the structure and content of farmers’ mental models differ by farmer type. The implications of the study findings for policy are discussed.
Global solutions and finite time blow-up for fourth order nonlinear damped wave equation
Authors: Xu Runzhang , Wang Xingchang , Yang Yanbing , Chen Shaohua
Published: June 2018

In this paper, we study the initial boundary value problem and global well-posedness for a class of fourth order wave equations with a nonlinear damping term and a nonlinear source term, which was introduced to describe the dynamics of a suspension bridge. The global existence, decay estimate, and blow-up of solution at both subcritical (E(0) < d) and critical (E(0) = d) initial energy levels are obtained. Moreover, we prove the blow-up in finite time of solution at the supercritical initial energy level (E(0) > 0).
Multiconfigurational short-range density-functional theory for open-shell systems
Authors: Hedegård Erik Donovan , Toulouse Julien , Jensen Hans Jørgen Aagaard
Published: June 2018

Many chemical systems cannot be described by quantum chemistry methods based on a single-reference wave function. Accurate predictions of energetic and spectroscopic properties require a delicate balance between describing the most important configurations (static correlation) and obtaining dynamical correlation efficiently. The former is most naturally done through a multiconfigurational (MC) wave function, whereas the latter can be done by, e.g., perturbation theory. We have employed a different strategy, namely, a hybrid between multiconfigurational wave functions and density-functional theory (DFT) based on range separation. The method is denoted by MC short-range DFT (MC–srDFT) and is more efficient than perturbative approaches as it capitalizes on the efficient treatment of the (short-range) dynamical correlation by DFT approximations. In turn, the method also improves DFT with standard approximations through the ability of multiconfigurational wave functions to recover large parts of the static correlation. Until now, our implementation was restricted to closed-shell systems, and to lift this restriction, we present here the generalization of MC–srDFT to open-shell cases. The additional terms required to treat open-shell systems are derived and implemented in the DALTON program. This new method for open-shell systems is illustrated on dioxygen and [Fe(H2O)6]3+.
Influences of adding negative couplings between cliques of Kuramoto-like oscillators
Authors: Yang Li-xin , Lin Xiao-lin , Jiang Jun
Published: June 2018

We study the dynamics in a clustered network of coupled oscillators by considering positive and negative coupling schemes. Second order oscillators can be interpreted as a model of consumers and generators working in a power network. Numerical results indicate that coupling strategies play an important role in the synchronizability of the clustered power network. It is found that the synchronizability can be enhanced as the positive intragroup connections increase. Meanwhile, when the intragroup interactions are positive and the probability p that two nodes belonging to different clusters are connected is increased, the synchronization has better performance. Besides, when the intragroup connections are negative, it is observed that the power network has poor synchronizability as the probability p increases. Our simulation results can help us understand the collective behavior of the power network with positive and negative couplings.
Critical roles of time-scales in soft tissue growth and remodeling
Authors: Latorre Marcos , Humphrey Jay D.
Published: June 2018

Most soft biological tissues exhibit a remarkable ability to adapt to sustained changes in mechanical loads. These macroscale adaptations, resulting from mechanobiological cellular responses, are important determinants of physiological behaviors and thus clinical outcomes. Given the complexity of such adaptations, computational models can significantly increase our understanding of how contributions of different cell types or matrix constituents, and their rates of turnover and evolving properties, ultimately change the geometry and biomechanical behavior at the tissue level. In this paper, we examine relative roles of the rates of tissue responses and external loading and present a new rate-independent approach for modeling the evolution of soft tissue growth and remodeling. For illustrative purposes, we also present numerical results for arterial adaptations. In particular, we show that, for problems defined by particular characteristic times, this approximate theory captures well the predictions of a fully general constrained mixture theory at a fraction of the computational cost.
Perspective: Stochastic magnetic devices for cognitive computing
Authors: Roy Kaushik , Sengupta Abhronil , Shim Yong
Published: June 2018

Stochastic switching of nanomagnets can potentially enable probabilistic cognitive hardware consisting of noisy neural and synaptic components. Furthermore, computational paradigms inspired from the Ising computing model require stochasticity for achieving near-optimality in solutions to various types of combinatorial optimization problems such as the Graph Coloring Problem or the Travelling Salesman Problem. Achieving optimal solutions in such problems are computationally exhaustive and requires natural annealing to arrive at the near-optimal solutions. Stochastic switching of devices also finds use in applications involving Deep Belief Networks and Bayesian Inference. In this article, we provide a multi-disciplinary perspective across the stack of devices, circuits, and algorithms to illustrate how the stochastic switching dynamics of spintronic devices in the presence of thermal noise can provide a direct mapping to the computational units of such probabilistic intelligent systems.
Strong light extraction enhancement using TiO2 nanoparticles-based microcone arrays embossed on III-Nitride light emitting diodes
Authors: Désières Yohan , Chen Ding Yuan , Visser Dennis , Schippers Casper , Anand Srinivasan
Published: June 2018

Colloidal TiO2 nanoparticles were used for embossing of composite microcone arrays on III-Nitride vertical-thin-film blue light emitting diodes (LEDs) as well as on silicon, glass, gallium arsenide, and gallium nitride surfaces. Ray tracing simulations were performed to optimize the design of microcones for light extraction and to explain the experimental results. An optical power enhancement of ∼2.08 was measured on III-Nitride blue LEDs embossed with a hexagonal array of TiO2 microcones of ∼1.35 μm in height and ∼2.6 μm in base width, without epoxy encapsulation. A voltage increase in ∼70 mV at an operating current density of ∼35 A/cm2 was measured for the embossed LEDs. The TiO2 microcone arrays were embossed on functioning LEDs, using low pressures (∼100 g/cm2) and temperatures ≤100 °C.
End-to-end distance and contour length distribution functions of DNA helices
Authors: Zoli Marco
Published: June 2018

I present a computational method to evaluate the end-to-end and the contour length distribution functions of short DNA molecules described by a mesoscopic Hamiltonian. The method generates a large statistical ensemble of possible configurations for each dimer in the sequence, selects the global equilibrium twist conformation for the molecule, and determines the average base pair distances along the molecule backbone. Integrating over the base pair radial and angular fluctuations, I derive the room temperature distribution functions as a function of the sequence length. The obtained values for the most probable end-to-end distance and contour length distance, providing a measure of the global molecule size, are used to examine the DNA flexibility at short length scales. It is found that, also in molecules with less than ∼60 base pairs, coiled configurations maintain a large statistical weight and, consistently, the persistence lengths may be much smaller than in kilo-base DNA.
Resonance of scroll rings with periodic external fields in excitable media
Authors: Pan De-Bei , Li Qi-Hao , Zhang Hong
Published: June 2018

By direct numerical simulations of a chemical reaction-diffusion system coupled to a periodic external AC electric field with frequency equal to double frequency of the scroll wave rotation, we find that scroll rings resonate with the electric field and exhibit various dynamical behaviors, for example, their reversals, collapses, or growths, depending both on the initial phase of AC electric fields and on the initial phase of scroll rings. A kinematical model characterizing the drift velocity of the scroll rings along their radial directions as well as that of the scroll rings along their symmetry axes is proposed, which can effectively account for the numerical observations and predict the behaviors of the scroll rings. Besides, the existence of the equilibrium state of a scroll ring under the AC electric fields is predicted by the kinematical model and the predictions agree well with the simulations.
Hardy’s paradox according to non-classical semantics
Authors: Bolotin Arkady
Published: June 2018

In this paper, using the language of spin-half particles, Hardy’s paradox is examined within different semantics: a partial one, a many-valued one, and the one defined as a set of weak values of projection operators. As it is shown in this paper, any of such non-classical semantics can resolve Hardy’s paradox.
Elementary fractal geometry. New relatives of the Sierpiński gasket
Authors: Bandt Christoph , Mekhontsev Dmitry
Published: June 2018

By slight modification of the data of the Sierpiński gasket, keeping the open set condition fulfilled, we obtain self-similar sets with very dense parts, similar to fractals in nature and in random models. This is caused by a complicated structure of the open set and is revealed only under magnification. Thus, the family of self-similar sets with separation condition is much richer and has higher modelling potential than usually expected. An interactive computer search for such examples and new properties for their classification are discussed.