Role of oxygen concentration in the osteoblasts behavior: A finite element model

Oxygen concentration plays a key role in cell survival and viability. Besides, it has important effects on essential cellular biological processes such as cell migration, differentiation, proliferation and apoptosis. Therefore, the prediction of the cellular response to the alterations of the oxygen concentration can help significantly in the advances of cell culture research. Here, we present a 3D computational mechanotactic model to simulate all the previously mentioned cell processes under different oxygen concentrations. With this model, three cases have been studied. Starting with mesenchymal stem cells within an extracellular matrix with mechanical properties suitable for its differentiation into osteoblasts, and under different oxygen conditions to evaluate their behavior under normoxia, hypoxia and anoxia. The obtained results, which are consistent with the experimental observations, indicate that cells tend to migrate toward zones with higher oxygen concentration where they accelerate their differentiation and proliferation. This technique can be employed to control cell migration toward fracture zones to accelerate the healing process. Besides, as expected, to avoid cell apoptosis under conditions of anoxia and to avoid the inhibition of the differentiation and proliferation processes under conditions of hypoxia, the state of normoxia should be maintained throughout the entire cell-culture process

In-situ spectroscopy of intrinsic Bi2Te3 topological insulator thin films and impact of extrinsic defects

Combined in-situ x-ray photoemission spectroscopy, scanning tunnelling spectroscopy and angle resolved photoemission spectroscopy of molecular beam epitaxy grown Bi2Te3 on lattice mismatched substrates reveal high quality stoichiometric thin films with topological surface states without a contribution from the bulk bands at the Fermi energy. The absence of bulk states at the Fermi energy is achieved without counter doping. We observe that the surface morphology and electronic band structure of Bi2Te3 are not affected by in-vacuo storage and exposure to oxygen, whereas major changes are observed when exposed to ambient conditions. These films help define a pathway towards intrinsic topological devices.Comment: 8 pages, 5 figure

Wyniki leczenia uszkodzenia nerwu strzałkowego na wysokości kolana: doświadczenie oddziału szpitala wo¡skowego

Background and purpose We investigated the management outcome of common peroneal nerve decompression at the knee level between the years 2005 and 2009. Material and methods Thirty consecutive patients with knee-level peroneal nerve injury who underwent decompression surgery and external neurolysis at our institution were evaluated preoperatively and postoperatively by electrophysiological studies and motor examination (Medical Research Council grading). Results Twenty-eight of the cases were male and 2 were female. Mean age was 31.1 for males and 57.5 for females. Physical activity during military training (overstretch/contusion) was the cause of nerve lesion in the majority of the patients (n = 28, 93%). Mean time interval between the diagnosis and the surgery was 5 months. Follow-up time ranged from 3 to 48 months (mean: 14 months). Twenty-nine of 30 (97%) patients recovered totally or near totally in foot/toe dorsiflexion. Conclusions Early decompression and neurolysis of the common peroneal nerve (CPN) at knee level after strenuous physical activity offers excellent functional recovery. Additionally, for knee-level CPN injuries, in order to minimize the postoperative scar, pain and delay in wound healing, we strictly advocate short ‘lazy S-shaped incision’ around the fibular head in supine position unlike the classical extensive opening up to the superior border of the popliteal fossa in prone position.Wstęp i cel pracy Autorzy ocenili wyniki chirurgicznego odbarczenia nerwu strzałkowego wspólnego na wysokości kolana, wykonywanego w latach 2005–2009. Materiał i metody Przedoperacyjnej i pooperacyjnej ocenie klinicznej (w skali Medical Research Council) oraz elektrofizjologicznej poddano 30 kolejnych pacjentów z uszkodzeniem nerwu strzałkowego na wysokości kolana, u których wykonano odbarczenie chirurgiczne z zewnętrzną neurolizą. Wyniki Wśród leczonych było 28 mężczyzn (średnia wieku: 31,1 roku) i dwie kobiety (średnia wieku: 57,5 roku). U zdecydowanej większości pacjentów (n = 28, 93%) przyczyną uszkodzenia nerwu była aktywność fizyczna w czasie szkolenia wojskowego (nadmierne rozciągnięcie/stłuczenie). Średnia czasu od rozpoznania do operacji wyniosła 5 miesięcy. Obserwacja po zabiegu trwała od 3 do 48 miesięcy (średnia: 14 miesięcy). U 29 na 30 chorych (97%) uzyskano pełny lub prawie pełny powrót zgięcia grzbietowego stopy/palców. Wnioski Wczesne chirurgiczne odbarczenie i neuroliza nerwu strzałkowego wspólnego na wysokości kolana w leczeniu urazu powstałego wskutek nadmiernej aktywności fizycznej daje możliwość znakomitej poprawy czynnościowej. Ponadto w przypadku uszkodzeń nerwu strzałkowego wspólnego na wysokości kolana w celu zminimalizowania blizny pooperacyjnej, nasilenia bólu i opóźnienia w gojeniu się rany pooperacyjnej autorzy usilnie zalecają krótkie cięcie w kształcie wydłużonej litery „S” wokół głowy strzałki u chorego w pozycji leżącej na plecach zamiast klasycznego otwarcia aż do górnej granicy dołu podkolanowego w pozycji leżącej na brzuchu

Petroleum-Collecting And Dispersing Chemicals For Cleaning Sea Surface From Thin Petroleum Slicks

Monoethylolamide, diethylolamide and triethanolamine ester synthesized by us based on fish oil and their phosphate derivatives being surface-active and ecologically safe possess a high capacity of petroleum collecting and dispersing. When introducing phosphate group, a tendency to replacement of petroleum slick dispersing by its collection (accumulation into a spot) is observed. Efficiency of the chemicals change depends on the type and concentration of ions in the water. Such salts as NaCl, KI, KBr, and MgSO4 positively influence petroleum-collecting activity whereas K2CO3 and NaHCO3 cause petroleum dispersing

The Fluvial and Water-Rich History of Northern Xanthe Terra: A Reference for the ExoMars Landing Site

We produced a geomorphological map of a study area in northern Xanthe Terra, which shares several characteristics with the ExoMars Rover landing site

Effects of Supersymmetric Threshold Corrections on High-Scale Flavor Textures

Integration of superpartners out of the spectrum induces potentially large contributions to Yukawa couplings. These corrections, the supersymmetric threshold corrections, therefore influence the CKM matrix prediction in a non-trivial way. We study effects of threshold corrections on high-scale flavor structures specified at the gauge coupling unification scale in supersymmetry. In our analysis, we first consider high-scale Yukawa textures which qualify phenomenologically viable at tree level, and find that they get completely disqualified after incorporating the threshold corrections. Next, we consider Yukawa couplings, such as those with five texture zeroes, which are incapable of explaining flavor-changing proceses. Incorporation of threshold corrections, however, makes them phenomenologically viable textures. Therefore, supersymmetric threshold corrections are found to leave observable impact on Yukawa couplings of quarks, and any confrontation of high-scale textures with experiments at the weak scale must take into account such corrections.Comment: 25 pages, submitted to JHE

ALACA: A platform for dynamic alarm collection and alert notification in network management systems

Mobile network operators run Operations Support Systems that produce vast amounts of alarm events. These events can have different significance levels and domains and also can trigger other ones. Network operators face the challenge to identify the significance and root causes of these system problems in real time and to keep the number of remedial actions at an optimal level, so that customer satisfaction rates can be guaranteed at a reasonable cost. In this paper, we propose a scalable streaming alarm management system, referred to as Alarm Collector and Analyzer, that includes complex event processing and root cause analysis. We describe a rule mining and root cause analysis solution for alarm event correlation and analyses. The solution includes a dynamic index for matching active alarms, an algorithm for generating candidate alarm rules, a sliding window–based approach to save system resources, and a graph-based solution to identify root causes. Alarm Collector and Analyzer is used in the network operation center of a major mobile telecom provider. It helps operators to enhance the design of their alarm management systems by allowing continuous analysis of data and event streams and predict network behavior with respect to potential failures by using the results of root cause analysis. We present experimental results that provide insights on performance of real-time alarm data analytics systems. Copyright © 2017 John Wiley & Sons, Ltd