54 research outputs found
In meso crystal structure of a novel membrane-associated octaheme cytochrome c from the Crenarchaeon Ignicoccus hospitalis
The Crenarchaeon Ignicoccus hospitalis lives in symbiosis with Nanoarchaeum equitans providing essential cell components and nutrients to its symbiont. Ignicoccus hospitalis shows an intriguing morphology that points toward an evolutionary role in driving compartmentalization. Therefore, the bioenergetics of this archaeal host–symbiont system remains a pressing question. To date, the only electron acceptor described for I. hospitalis is elemental sulfur, but the organism comprises genes that encode for enzymes involved in nitrogen metabolism, e.g., one nitrate reductase and two octaheme cytochrome c, Igni_0955 (IhOCC) and Igni_1359. Herein, we detail functional and structural studies of the highly abundant IhOCC, including an X-ray crystal structure at 1.7 Å resolution, the first three-dimensional structure of an archaeal OCC. The trimeric IhOCC is membrane associated and exhibits significant structural and functional differences to previously characterized homologs within the hydroxylamine oxidoreductases (HAOs) and octaheme cytochrome c nitrite reductases (ONRs). The positions and spatial arrangement of the eight hemes are highly conserved, but the axial ligands of the individual hemes 3, 6 and 7 and the protein environment of the active site show significant differences. Most notably, the active site heme 4 lacks porphyrin-tyrosine cross-links present in the HAO family. We show that IhOCC efficiently reduces nitrite and hydroxylamine, with possible relevance to detoxification or energy conservation
Efficient synthesis of pyrene-1-carbothioamides and carboxamides. Tunable solid-state fluorescence of pyrene-1-carboxamides
Pyrene reacts with potassium thiocyanate and organic isothiocyanates in the presence of
trifluoromethanesulfonic acid to afford primary and secondary pyrene-1-carbothioamides in high yields.
These compounds were efficiently oxidatively desulfurized with Oxone® to the corresponding
carboxamides. The amides display solid-state fluorescence with quantum efficiencies up to 62%,
originating from monomers, aggregates (such as preformed dimers), and/or excimers, depending on the
substituent at the nitrogen atom. Single crystal X-ray diffraction characterization of one highly emissive
compound supports this assumption.Publikacja w ramach programu Royal Society of Chemistry "Gold for Gold" 2014 finansowanego przez Uniwersytet Łódzki
Congenital monomelic muscular hypertrophy of the upper extremity.
Pathological muscular hypertrophy results from either muscular or neurogenic damage. Rarely, it is caused by a congenital malformation consisting of a unilateral muscular hyperplasia of the upper extremity. We report on a young woman with an enlargement of the right upper extremity. Electromyography showed polyphasic, large motor unit potentials in the affected muscles. MRI and ultrasound assessment demonstrated diffuse enlargement of muscle mass without signs of edema. Muscle biopsy revealed sections with marked variations in fiber size with no signs of inflammation or marked loss of muscle fibers. Factors assumed to be important in the pathophysiology of this phenomenon are discussed
Reconstruction of defects involving the Achilles tendon and local soft tissues A QUICK SOLUTION FOR A LINGERING PROBLEM
A total of seven patients (six men and one woman) with a defect in the Achilles tendon and overlying soft tissue underwent reconstruction using either a composite radial forearm flap (n = 3) or an anterolateral thigh flap (n = 4). The Achilles tendons were reconstructed using chimeric palmaris longus (n = 2) or tensor fascia lata (n = 2) flaps or transfer of the flexor hallucis longus tendon (n = 3). Surgical parameters such as the rate of complications and the time between the initial repair and flap surgery were analysed. Function was measured objectively by recording the circumference of the calf, the isometric strength of the plantar flexors and the range of movement of the ankle. The Achilles tendon Total Rupture Score (ATRS) questionnaire was used as a patient-reported outcome measure. Most patients had undergone several previous operations to the Achilles tendon prior to flap surgery. The mean time to flap surgery was 14.3 months (2.1 to 40.7). At a mean follow-up of 32.3 months (12.1 to 59.6) the circumference of the calf on the operated lower limb was reduced by a mean of 1.9 cm (SD 0.74) compared with the contralateral limb (p = 0.042). The mean strength of the plantar flexors on the operated lower limb was reduced to 88.9% of that of the contralateral limb (p = 0.043). There was no significant difference in the range of movement between the two sides (p = 0.317). The mean ATRS score was 72 points (SD 20.0). One patient who had an initial successful reconstruction developed a skin defect of the composite flap 12 months after free flap surgery and this resulted in recurrent infections, culminating in transtibial amputation 44 months after reconstruction. These otherwise indicate that reconstruction of the Achilles tendon combined with flap cover results in a successful and functional reconstruction
Manifestations of Non-Planar Adsorption Geometries of Lead Pyrenocyanine at the Liquid-Solid Interface
In this work, we provide evidence for multiple non-planar adsorption geometries of a novel pyrenocyanine derivative at the liquid-solid interface under ambient conditions. When adsorbed at the organic liquid-solid interface, lead pyrenocyanine forms well-ordered monolayers that exhibit peculiar non-periodic contrast variation. The different contrast of the adsorbed molecules is attributed to dissimilar adsorption geometries which arise from the non-planar conformation of the molecules. The non-planarity of the molecular backbone in turn arises due to a combination of the angularly extended pyrene subunits and the presence of the large lead ion, which is too big to fit inside the central cavity and thus is located out of the aromatic plane. The two possible locations of the lead atom, namely below and above the aromatic plane, could be identified as depression and protrusion in the central cavity, respectively. The manifestation of such multiple adsorption geometries on the structure of the resultant monolayer is discussed in detail. The packing density of these 2D arrays of molecules could be tuned by heating of the sample wherein the molecular packing changes from a low-density, pseudo six-fold symmetric to a high-density, two-fold symmetric arrangement. Finally, a well-ordered two-component system could be constructed by incorporating C60 molecules in the adlayer of lead pyrenocyanine at the liquid-solid interface.status: publishe
Cubital tunnel syndrome: A comparison of an endoscopic technique with a minimal invasive open technique
Both open and endoscopic methods for ulnar nerve decompression have been described. The purpose of this study is to compare the 6-month results of a minimal invasive open technique with an endoscopic technique. We treated 60 patients with unilateral ulnar neuropathy at the elbow, employing both techniques. Six months postoperative we found no differences in treatment effect on pain and disability scores between both groups, but both techniques resulted in an early postoperative relief of symptoms and good patient satisfaction
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