Alignment and rectifying properties of donor-electron bridge-acceptor molecules

Molecular electronics based on the bottom-up approach appears to be a promising alternative to overcome the limitations of the top-down lithographic fabrication of electronic devices. The ability to manipulate single or small groups of molecules provides a great opportunity to build electronic devices at the molecular level. However, before any device can be constructed, it is vital to understand the parameters that control the device properties such as: molecular structure, conformation and arrangement at the surface, the molecule-substrate and molecule-electrode interactions. This thesis presents an investigation of the alignment of acceptor-electron bridge-donor structures and describes how the molecular structure and arrangement affect rectifying properties of the monolayers. Studies included typical Langmuir-Blodgett (LB), chevron-shaped, and ionically coupled structures that were characterised using various techniques, such as Quartz Crystal Microbalance (QCM), Surface Plasmon Resonance (SPR), Second Harmonic Generation (SHG) and Scanning Tunnelling Spectroscopy (STS). The results obtained showed that to achieve high rectification the molecules must form ordered and stable monolayers that are able to withstand the electric field applied to the junction. It was also shown that due to the disordered monolayer formation and presence of certain ions, it was extremely difficult to state without doubt whether the rectification was a result of the donor-electron bridge-acceptor structure proposed by Aviram and Ratner1. Studies of chevron-shaped molecules confirmed the possibility of depositing them using the LB technique. However, the reduction of long aliphatic chains was very likely balanced by the formation of less ordered or unstable monolayers. The highest rectification ratio of 30 ± 3 at ± 1 V was obtained for 1-butyl-2,6-bis-[2-(4- dibutylamino-phenyl)-vinyl]-pyridinium iodide (dye 7) and the origin of the I-V asymmetry was attributed to back electron transfer from iodide to pyridinium ring. Although dye 1-butyl-2,6-bis-(2-{4-[2-(4-dibutylamino-phenyl)-ethyl]-phenyl}-vinyl)- pyridinium iodide (dye 9) showed electrical asymmetry (RR=16 at plus/minus 1 V) shortly after deposition onto the gold-coated highly oriented pyrolytic graphite (HOPG), it seemed to form an unstable alignment and as a consequence the rectification decayed over a period of a few hours. Improved ordering, stability, and rectification were achieved from ionically coupled structures, where the monolayers were formed using chemisorption and ionic assembly instead of physisorption.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Bypassing cellular EGF receptor dependence through epithelial-to-mesenchymal-like transitions

Over 90% of all cancers are carcinomas, malignancies derived from cells of epithelial origin. As carcinomas progress, these tumors may lose epithelial morphology and acquire mesenchymal characteristics which contribute to metastatic potential. An epithelial-to-mesenchymal transition (EMT) similar to the process critical for embryonic development is thought to be an important mechanism for promoting cancer invasion and metastasis. Epithelial-to-mesenchymal transitions have been induced in vitro by transient or unregulated activation of receptor tyrosine kinase signaling pathways, oncogene signaling and disruption of homotypic cell adhesion. These cellular models attempt to mimic the complexity of human carcinomas which respond to autocrine and paracrine signals from both the tumor and its microenvironment. Activation of the epidermal growth factor receptor (EGFR) has been implicated in the neoplastic transformation of solid tumors and overexpression of EGFR has been shown to correlate with poor survival. Notably, epithelial tumor cells have been shown to be significantly more sensitive to EGFR inhibitors than tumor cells which have undergone an EMT-like transition and acquired mesenchymal characteristics, including non-small cell lung (NSCLC), head and neck (HN), bladder, colorectal, pancreas and breast carcinomas. EGFR blockade has also been shown to inhibit cellular migration, suggesting a role for EGFR inhibitors in the control of metastasis. The interaction between EGFR and the multiple signaling nodes which regulate EMT suggest that the combination of an EGFR inhibitor and other molecular targeted agents may offer a novel approach to controlling metastasis

XLIV Konferencja Komitetu Nauk o Żywności i Żywieniu PAN: nauka, technologia i innowacje w żywności i żywieniu

Streszczenia w jęz. angielskimWydarzenie: XLIV Konferencja Komitetu Nauk o Żywności i Żywieniu PAN; Łódź, 3-4 lipca 2019 r.; http://pan.binoz.p.lodz.plOrganizator konferencji: Wydział Biotechnologii i Nauk o Żywności PŁ; Komitet Nauk o Żywności i Żywieniu PAN; Polskie Towarzystwo Technologów ŻywnościProjekt graficzny okładki: Grzelczyk, J.Projekt graficzny okładki: Klewicki, R.Skład: Oracz, J.Za treść zamieszczonych materiałów odpowiadają ich autorzy.Sesje Naukowe Komitetu Nauk o Żywności i Żywieniu Polskiej Akademii Nauk (KNoŻiŻ PAN) są organizowane przez krajowe ośrodki akademickie związane z naukami o żywności i żywieniu w dwuletnich cyklach. Sesje te stanowią największe w skali kraju forum prezentacji najnowszych osiągnięć naukowych i technologicznych w dziedzinie technologii żywności i żywienia człowieka, jak również wymiany poglądów oraz doświadczeń pracowników jednostek naukowych i przedstawicieli przemysłu spożywczego. Tematyka XLIV Sesji dotyczyć będzie szeroko pojętej problematyki związanej z oddziaływaniem żywności i odżywiania na zdrowie człowieka

New isotopic data on karst development in the northern Kraków-Wieluń Upland (southern Poland)

The Kraków-Wieluñ Upland is one of the major palaeokarst regions in Poland. However, the stages of karst development in this area are neither well documented nor reconstructed. A series of samples from a new location in the vicinity of Raciszyn was analysed. On the basis of the results of U-series dating, four phases of speleothem deposition were distinguished: (1) older than 600 ka, (2) from more than 600 ka to 290 ka, (3) around 150 ka, and the youngest (4), younger than 3 ka. On the basis of all geochronological data from the region, eight stages of karst development were described. The structure of the oldest speleothems indicates even more stages of deposition and erosion that cannot be recognized using the 230Th/234U dating method. These results indicate that the initial creation of empty spaces in the limestone took place in pre-Pleistocene time. After 600 ka ago, climatic conditions were stable for more than 300 ka, allowing the continuous deposition of speleothems. Several episodes of erosion, deposition of clastic sediments and speleothem growth during the Middle and Early Pleistocene were described. This variability of the sedimentation regime clearly reflects climate changes during that period

Antral Preservation in Sleeve Gastrectomy Appears to Protect Against Prolonged Vomiting and Gastroesophageal Reflux Disease. A Meta-Analysis of Randomized Controlled Trials.

The optimal distance between the starting point of gastric transection and the pylorus during laparoscopic sleeve gastrectomy (LSG), which can be referred to as the distance from pylorus (DFP), is controversial. No consensus exist for what DFP is considered antral preservation, and what DFP is considered antral resection. Some surgeons prefer shorter DFP to maximize excess weight loss percentage (EWL%), while others prefer longer DFP because they believe that it shortens length of stay (LOS) and protects against leaks, prolonged vomiting, and gastroesophageal reflux disease (GERD). We sought to compare 6-cm DFP and 2-cm DFP in postoperative outcomes. In addition, we sought to evaluate the magnitude of any observed benefit through number needed to treat (NNT) analysis

Seamguard Buttressing of the Staple Line During Laparoscopic Sleeve Gastrectomy Appears to Decrease the Incidence of Postoperative Bleeding, Leaks, and Reoperations. A Systematic Review and Meta-Analysis of Non-Randomized Comparative Studies.

Leaks and bleeding are major acute postoperative complications following laparoscopic sleeve gastrectomy (LSG). Various staple line reinforcement (SLR) methods have been invented such as oversewing/suturing (OS/S), omentopexy/gastropexy (OP/GP), gluing, and buttressing. However, many surgeons do not use any type of reinforcement. On the other hand, surgeons who use a reinforcement method are often confused of what kind of reinforcement they should use. No robust and high-quality data supports the use of one reinforcement over the other or even supports the use of reinforcement over no-reinforcement. Therefore, SLR is a controversial topic that is worth our focus. The aim of this study is to compare the outcomes of LSG with versus without Seamguard buttressing of the staple line during LSG