Bott--Kitaev periodic table and index theory

We consider topological insulators and superconductors with discrete symmetries and clarify the relevant index theory behind the periodic table proposed by Kitaev. An effective Hamiltonian determines the analytical index, which can be computed by a topological index. We focus on the spatial dimensions one, two and three, and only consider the bulk theory. In two dimensions, the $\mathbb{Z}$-valued invariants are given by the first Chern number. Meanwhile, $\mathbb{Z}_2$-valued invariants can be computed by the odd topological index and its variations. The Bott-Kitaev periodic table is well-known in the physics literature, we organize the topological invariants in the framework of KR-theory.Comment: 37 page

EARLY PROBIOTICS IN PREVENTING VENTILATOR-ASSOCIATED PNEUMONIA AFTER MULTIPLE TRAUMA

Objective: Using probiotics in preventing ventilator-associated pneumonia (VAP) remain controversial due to different intensive care unit (ICU) populations included in such studies. The aim of this study is to evaluate the role of probiotics in prophylaxis of VAP after multiple trauma. Methods: Sixty-five adult multiple trauma patients on mechanical ventilator (expected ≥48 h) after admission to the Critical Care Medicine Department, Alexandria Main University Hospital from June to November 2018. Patients were randomly assigned using computer sheet into two groups; probiotics group (32 patients received one Lacteol Forte® sachet through orogastric/nasogastric tube 3 times daily during their ICU stay) and control group (33 patients received similar regimen of placebo sachets). All patients were followed up and subjected to all possible strategies of the diagnosis of microbiologically confirmed VAP. Results: Sixty-five patients were enrolled with a mean of age (39.48±7.692) years, 80% of them were male. Regarding the incidence of VAP, it was 18.46% of all patients without statistically significant difference between probiotics group (15.63%) and control group (21.21%) (p=0.751). Conclusion: Routine use of early probiotics in mechanically ventilated multiple trauma patients was not associated with lower incidence of VAP, duration of MV, or ICU mortality

Synthesis of Novel 6-(4-Substituted piperazine-1-yl)-9(b-D-ribofuranosyl) purine Derivatives, Which Lead to Senescence-Induced Cell Death in liver Cancer Cells

Cataloged from PDF version of article.Novel purine ribonucleoside analogues (9-13) containing a 4-substituted piperazine in the substituent at N-6 were synthesized and evaluated for their cytotoxicity on Huh7, HepG2, FOCUS, Mahlavu liver, MCF7 breast, and HCT116 colon carcinoma cell lines. The purine nucleoside analogues were analyzed initially by an anticancer drug-screening method based on a sulforhodamine B assay. Two nucleoside derivatives with promising cytotoxic activities (11 and 12) were further analyzed on the hepatoma cells. The N-6-(4-Trifluoromethylphenyl)piperazine analogue 11 displayed the best antitumor activity, with IC50 values between 5.2 and 9.2 mu M. Similar to previously described nucleoside analogues, compound 11 also interferes with cellular ATP reserves, possibly through influencing cellular kinase activities. Furthermore, the novel nucleoside analogue 11 was shown to induce senescence-associated cell death, as demonstrated by the SA beta-gal assay. The senescence-dependent cytotoxic effect of 11 was also confirmed through phosphorylation of the Rb protein by p15(INK4b) overexpression in the presence of this compound

Molecular SPECT Imaging: An Overview

Molecular imaging has witnessed a tremendous change over the last decade. Growing interest and emphasis are placed on this specialized technology represented by developing new scanners, pharmaceutical drugs, diagnostic agents, new therapeutic regimens, and ultimately, significant improvement of patient health care. Single photon emission computed tomography (SPECT) and positron emission tomography (PET) have their signature on paving the way to molecular diagnostics and personalized medicine. The former will be the topic of the current paper where the authors address the current position of the molecular SPECT imaging among other imaging techniques, describing strengths and weaknesses, differences between SPECT and PET, and focusing on different SPECT designs and detection systems. Radiopharmaceutical compounds of clinical as well-preclinical interest have also been reviewed. Moreover, the last section covers several application, of μSPECT imaging in many areas of disease detection and diagnosis

Hydrogels and Their Combination with Liposomes, Niosomes, or Transfersomes for Dermal and Transdermal Drug Delivery

Polymeric networks that retain and absorb substantial amount of water or biological fluids and resemble as a biological tissue are defined as hydrogels. On the other hand, liposomes, transfersomes and niosomes are lipid carriers, which represent one of the major research and development focus areas of the pharmaceutical industry. They have great potential as lipid vehicles that are able to enhance permeation of drugs across the intact skin and can act as local depot for the drug to sustain and control its delivery. Lipid carrier and hydrogel combinations offer transdermal drug delivery of great potential to enhance systemic effects of both hydrophilic and lipophilic drugs. Also, lipid carriers can target drugs to skin appendages and improve transdermal delivery. Lipid carrier proform systems in the form of gelly liquid crystals can also be used transdermally for better drug absorption enhancement. This review highlights the potential of hydrogels and emulgels with or without lipid nanocarriers for dermal and transdermal application

A Simple Angle of Arrival Estimation System

We propose a practical, simple and hardware friendly, yet novel and very efficient, angle of arrival (AoA) estimation system. Our intuitive, two-phases cross-correlation based system requires a switched beam antenna array with a single radio frequency chain. Our system cross correlates a reference omni-directional signal with a set of received directed signals to determine the AoA. Practicality and high efficiency of our system are demonstrated through performance and complexity comparisons with multiple signal classification algorithm.Scopu

Exploiting Spectrum Sensing Data for Key Management

In cognitive radio networks, secondary users (SUs) communicate on unused spectrum slots in the frequency bands assigned to primary users (PUs). Like any other wireless communication system, cognitive radio networks are ex- posed to physical layer attacks. In particular, we focus on two common at- tacks, namely, spectrum sensing data falsification and eavesdropping. Such attacks can be counteracted by using symmetric key algorithms, which how- ever require a complex key management scheme. In this paper we propose a novel algorithm that significantly reduces the complexity of the management of symmetric link keys by leveraging spectrum sensing data that is available to all nodes. In our algorithm, it is assumed that a primary secret key is pre-distributed to the legitimate SUs, which is needed every number of de- tection cycles. With the aid of the information provided in the primary key, our algorithm manipulates the collected samples so that a segment of the estimated sensing statistic at the two legitimate SUs can be used as a seed to generate a common symmetric link key. The link key is then employed to encrypt the transmitted data. Our algorithm exhibits very good performance in terms of bit mismatch rate (BMR) between two link keys generated at the two legitimate SUs. In addition, our solution is robust against the difference in the received signal to noise ratio between two legitimate SUs thus making it suitable for practical scenarios. Furthermore, our algorithm exploits the decision statistic that SUs use for spectrum sensing, hence, it does require neither extra processing nor extra time, allowing the SUs to quickly and securely tab into empty spectrum slots