Browsing by Subject "X-ray"

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  • Aly, Ashraf A.; Hassan, Alaa A.; Bräse, Stefan; Ibrahim, Mahmoud A. A.; Abd Al-Latif, El-Shimaa S. M.; Spuling, Eduard; Nieger, Martin (2017)
    Bisthioureas reacted with either 2-(bis(methylthio)methylene)malononitrile or ethyl 2-cyano-3,3-bis(methylthio)acrylate to give 1,3,4-thiadiazoles and 1,3-thiazoles. Only, the reactive allyl derivative of bisthioureas reacted with the bis(methylthio)methylene compounds to give 1,3-thiazoles. The mechanism was discussed. The structures of products were proved by MS, IR, NMR and elemental analyses and X-ray structure analysis. [GRAPHICS]
  • Aly, Ashraf A.; El-Emary, Talaat; Mourad, Aboul-Fetouh E.; Alyan, Zainab Khallaf; Bräse, Stefan; Nieger, Martin (2019)
    5-Carbohydrazides and 5-carbonylazides of pyrazolo[3,4-b]pyridines are used to synthesize new heterocyclic derivatives. Some unexpected behaviors are observed in the reactions of the above two species. The structures of the obtained compounds are proved by spectroscopic studies together with elemental and X-ray structure analyses.
  • Viitanen, Akke Esa Tapio (Helsingin yliopisto, 2017)
    Active galactic nuclei (AGN) are compact, luminous objects found in the central region of many galaxies. In the standard paradigm, the AGN is fueled by accretion of matter into a supermassive black hole (SMBH). In fact, the properties of many galaxies and their respective SMBHs are linked, which hints at the importance of AGN as factors in galaxy formation and evolution. The bulk of the matter in the Universe is some form of dark matter, which is still poorly understood. AGN are biased tracers of the underlying dark matter distribution. By comparing the clustering of AGN with that of the dark matter, the bias may be quantified and further, the bias can be linked to a characteristic mass of the dark matter halo hosting the AGN. The advent of high-resolution X-ray telescopes, namely Chandra and XMM-Newton, has made unprecedently large samples available for study. With detailed spectroscopic follow-up programs, the study of X-ray selected AGN clustering has received a major boost. The clustering measurements tell of the typical environments that are likely to host AGN and thus shed light on what actually triggers the AGN. In this thesis, the clustering of ∼ 600 X-ray selected AGN with z < 2.5 (z = 1.19) in the COS- MOS (Cosmic evolution survey) field surveyed with XMM-Newton (XMM-COSMOS) is studied. The full sample is split into subsamples based on the host galaxy stellar mass M∗ and the ratio between the X-ray luminosity and the stellar mass LX/M∗ which is a proxy for the Eddington ratio. For the full sample the bias is 3.61+0.37−0.40, which corresponds to a characteristic halo mass of log M halo /h−1 M⊙ = 13.52+0.12−0.16 , consistent with the overall picture of X-ray selected AGN residing in massive haloes with 12.5 < logMhalo/h−1M⊙ < 13.5. The low M∗ and high M∗ samples have biases 3.53+0.58−0.70 and 4.13+0.85−1.07, respectively and the data do not support a difference in the typical masses of the hosting haloes. For the LX/M∗ subsamples, there is marginal evidence that low L X /M∗ AGN (logM halo /h−1M⊙ = 13.52+0.22−0.37) reside in more massive haloes than high L X /M∗ AGN (logM halo /h−1M⊙ = 13.29+0.28−0.58). One possible explanation would be that the environment of the low LX /M∗ AGN reduces the amount of gas available for accretion and thus results in lower accretion rates.
  • Nieminen, H. J.; Ylitalo, T.; Karhula, S.; Suuronen, J. -P.; Kauppinen, S.; Serimaa, R.; Haeggstrom, E.; Pritzker, K. P. H.; Valkealahti, M.; Lehenkari, P.; Finnila, M.; Saarakkala, S. (2015)
    Objective: Collagen distribution within articular cartilage (AC) is typically evaluated from histological sections, e.g., using collagen staining and light microscopy (LM). Unfortunately, all techniques based on histological sections are time-consuming, destructive, and without extraordinary effort, limited to two dimensions. This study investigates whether phosphotungstic acid (PTA) and phosphomolybdic acid (PMA), two collagen-specific markers and X-ray absorbers, could (1) produce contrast for AC X-ray imaging or (2) be used to detect collagen distribution within AC. Method: We labeled equine AC samples with PTA or PMA and imaged them with micro-computed tomography (micro-CT) at pre-defined time points 0, 18, 36, 54, 72, 90, 180, 270 h during staining. The micro-CT image intensity was compared with collagen distributions obtained with a reference technique, i.e., Fourier-transform infrared imaging (FTIRI). The labeling time and contrast agent producing highest association (Pearson correlation, BlandeAltman analysis) between FTIRI collagen distribution and micro-CT -determined PTA distribution was selected for human AC. Results: Both, PTA and PMA labeling permitted visualization of AC features using micro-CT in non-calcified cartilage. After labeling the samples for 36 h in PTA, the spatial distribution of X-ray attenuation correlated highly with the collagen distribution determined by FTIRI in both equine (mean +/- S.D. of the Pearson correlation coefficients, r = 0.96 +/- 0.03, n = 12) and human AC (r = 0.82 +/- 0.15, n = 4). Conclusions: PTA-induced X-ray attenuation is a potential marker for non-destructive detection of AC collagen distributions in 3D. This approach opens new possibilities in development of non-destructive 3D histopathological techniques for characterization of OA. (C) 2015 The Authors. Published by Elsevier Ltd and Osteoarthritis Research Society International.
  • Aly, Ashraf A.; El-Sheref, Essmat M.; Brown, Alan B.; Braese, Stefan; Nieger, Martin; Abdelhafez, El-Shinnaa M. N. (2019)
    A new one pot reaction of substituted thiosemicarbazides with 2-bromoacetophenone and carbonyl compounds gave 2-hydrazonothiazoles in good yields. The structures of the isolated compounds were corroborated by NMR, IR, mass spectra and elemental analyses in addition to X-ray structure determination. [GRAPHICS] .
  • Aly, Ashraf A.; Bräse, Stefan; Hassan, Alaa A.; Mohamed, Nasr K.; Abd El-Haleem, Lamiaa E.; Nieger, Martin; Morsy, Nesrin M.; Abdelhafez, Elshimaa M. N. (2020)
    A new series of methyl 2-(2-(4 '-[2.2]paracyclophanyl)-hydrazinylidene)-3-substituted-4-oxothiazolidin-5-ylidene)acetates3a-fwere synthesized from the reaction of paracyclophanyl-acylthiosemicarbazides2a-fwith dimethyl acetylenedicarboxylate. Based upon nuclear magnetic resonance (NMR), infrared (IR), and mass spectra (HRMS), the structure of the obtained products was elucidated. X-ray structure analysis was also used as unambiguous tool to elucidate the structure of the products. The target compounds3a-fwere screened against 60 cancer cell lines. They displayed anticancer activity against a leukemia subpanel, namely, RPMI-8226 and SR cell lines. The activity of compound3awas found as the most cytotoxic potency against 60 cancer cell lines. Consequently, it was selected for further five doses analysis according to National Cancer Institute (NCI) protocol. The cytotoxic effect showed selectivity ratios ranging between 0.63 and 1.28 and between 0.58 and 5.89 at the GI(50)and total growth inhibition (TGI) levels, respectively. Accordingly, compound3aunderwent further mechanistic study against the most sensitive leukemia RPMI-8226 and SR cell lines. It showed antiproliferation with IC50 = 1.61 +/- 0.04 and 1.11 +/- 0.03 mu M against RPMI-8226 and SR cell lines, respectively. It also revealed a remarkable tubulin inhibitory activity, compared to colchicine with IC50 = 4.97 mu M/mL. Caspase-3, BAX, and Bcl-2 assays for3ausing annexin V-FITC staining revealed significant pro-apoptotic activity. Furthermore, multidrug-resistant leukemia SR cells were used to show better resistance indices (1.285 ng/mL, 1.15-fold) than the reference. Docking studies with beta-tubulin indicate that most of the tested compounds illustrated good binding at the colchicine binding site of the enzyme, especially for compound3a, which made several interactions better than that of the reference colchicine.
  • Aly, Ashraf A.; El-Sheref, Essmat M.; Mourad, Aboul-Fetouh E.; Bakheet, Momtaz E. M.; Bräse, Stefan; Nieger, Martin (2019)
    In this investigation an efficient synthesis of 2,3-bis-(4-hydroxy-2-oxo-1,2-dihydroquinolin-3-yl)succinic acid derivatives was achieved by one-pot reaction of one equivalent of aromatic amines with two equivalents of diethyl malonate in diphenyl ether and catalyzed with triethylamine. In case of applying the previous condition with aromatic amines and diethyl malonate in a ratio of 2:1, no quinolone structure was obtained, whereas N-1,N-3-bis(4-bromophenyl)malonamide, as an example, was obtained in 95% yield. Under the same previous condition, arylmethylene-bis-3,3-quinoline-2-ones were in one pot synthesized via the reaction of equal equivalents of aromatic amines and diethyl malonate together with half equivalent of the corresponding aromatic aldehydes. The structure of the obtained compounds was proved by IR, NMR and mass spectra and X-ray structure analyses. [GRAPHICS] .
  • Coccolini, Federico; Stahel, Philip F.; Montori, Giulia; Biffl, Walter; Horer, Tal M.; Catena, Fausto; Kluger, Yoram; Moore, Ernest E.; Peitzman, Andrew B.; Ivatury, Rao; Coimbra, Raul; Fraga, Gustavo Pereira; Pereira, Bruno; Rizoli, Sandro; Kirkpatrick, Andrew; Leppäniemi, Ari; Manfredi, Roberto; Magnone, Stefano; Chiara, Osvaldo; Solaini, Leonardo; Ceresoli, Marco; Allievi, Niccolo; Arvieux, Catherine; Velmahos, George; Balogh, Zsolt; Naidoo, Noel; Weber, Dieter; Abu-Zidan, Fikri; Sartelli, Massimo; Ansaloni, Luca (2017)
    Complex pelvic injuries are among the most dangerous and deadly trauma related lesions. Different classification systems exist, some are based on the mechanism of injury, some on anatomic patterns and some are focusing on the resulting instability requiring operative fixation. The optimal treatment strategy, however, should keep into consideration the hemodynamic status, the anatomic impairment of pelvic ring function and the associated injuries. The management of pelvic trauma patients aims definitively to restore the homeostasis and the normal physiopathology associated to the mechanical stability of the pelvic ring. Thus the management of pelvic trauma must be multidisciplinary and should be ultimately based on the physiology of the patient and the anatomy of the injury. This paper presents the World Society of Emergency Surgery (WSES) classification of pelvic trauma and the management Guidelines.
  • Faria, J. C. T.; Melo, L. A.; Assumpcao, C. R. M.; Brondani, G. E.; Breier, T. B.; Faria, J. M. R. (2019)
    This study aimed to analyze the physical properties of the seeds of Moquiniastrum polymorphum when processed by mini-SAS, X-ray and seed blower systems. The seeds were purchased from Seeds Caicara, located in Penapolis-SP. After purchase, the seed lot was characterized by standard tests. In the X-ray test the seeds were classified according to their internal morphology as filled, unfilled or malformed. The seed blower was set at six opening settings, resulting in light and heavy fractions. The evaluations were performed by weighing the seeds that remained in the blower (heavy fraction) and by the amount of filled seeds indicated by the X-ray test. The germination tests were composed of four replicates of 50 seeds. The mini-SAS was used for external evaluation. It was concluded that the combined use of the seed blower and the X-ray test was efficient for the evaluation and determination of the physical quality of the seeds of M. polymorphum. The seed blower at opening settings 5 resulted in the best lot quality. The external parameters were not able to qualitatively evaluate the seeds of M. polymorphum.
  • Aly, Ashraf A.; Hassan, Alaa A.; Mohamed, Nasr K.; Abd El-Haleem, Lamiaa E.; Bräse, Stefan; Polamo, Mika; Nieger, Martin; Brown, Alan B. (2019)
    Herein, we report the synthesis of 5,12-dihydropyrazino[2,3-c:5,6-c ' ]difuro[2,3-c:4,5-c ']-diquinoline-6,14(5H,12H)diones, 2-(4-hydroxy-2-oxo-1,2-dihydroquinolin-3-yl)-1,4-diphenyl- butane-1,4-diones and 4-(benzo-[d]oxazol-2-yl)-3-hydroxy-1H-[4,5]oxazolo[3,2-a]pyridine-1-one. The new candidates were synthesized and identified by different spectroscopic techniques, and X-ray crystallography.
  • Suuronen, Jussi-Petteri; Peura, Marko; Fagerstedt, Kurt; Serimaa, Ritva (2013)
    Background The hydraulic conductivity of the stem is a major factor limiting the capability of trees to transport water from the soil to transpiring leaves. During drought conditions, the conducting capacity of xylem can be reduced by some conduits being filled with gas, i.e. embolized. In order to understand the dynamics of embolism formation and repair, considerable attention has been given to developing reliable and accurate methods for quantifying the phenomenon. In the past decade, non-destructive imaging of embolism formation in living plants has become possible. Magnetic resonance imaging has been used to visualize the distribution of water within the stem, but in most cases it is not possible to resolve individual cells. Recently, high-resolution synchrotron x-ray microtomography has been introduced as a tool to visualize the water contents of individual cells in vivo, providing unprecedented insight into the dynamics of embolism repair. We have investigated the potential of an x-ray tube -based microtomography setup to visualize and quantify xylem embolism and embolism repair in water-stressed young saplings and shoot tips of Silver and Curly birch (Betula pendula and B. pendula var. carelica). Results From the microtomography images, the water-filled versus gas-filled status of individual xylem conduits can be seen, and the proportion of stem cross-section that consists of embolized tissue can be calculated. Measuring the number of embolized vessels in the imaged area is a simple counting experiment. In the samples investigated, wood fibers were cavitated in a large proportion of the xylem cross-section shortly after watering of the plant was stopped, but the number of embolized vessels remained low several days into a drought period. Under conditions of low evaporative demand, also refilling of previously embolized conduits was observed. Conclusions Desktop x-ray microtomography is shown to be an effective method for evaluating the water-filled versus embolized status of the stem xylem in a small living sapling. Due to its non-destructive nature, the risk of inducing embolisms during sampling is greatly reduced. Compared with synchrotron imaging beamlines, desktop microtomography offers easier accessibility, while maintaining sufficient resolution to visualize the water contents of individual cells.