Bio-based production of silver nanoparticles represents a sustainable alternative to commercially applied physicochemical manufacturing approaches and provides qualitatively highly valuable nanomaterials due to their narrow size dispersity, high stability and biocompatibility with broad application potentials. The intrinsic features of nanoparticles depend on size and shape, whereby the controlled synthesis is a challenging necessity. In the present study, the biosynthesis of size-tuned silver nanoparticles based on cell-free extracts of Saccharomyces cerevisiae DSM 1333 was investigated.
View Article and Find Full Text PDFAntimicrobial photodynamic therapy (aPDT) is an evolving treatment strategy against human pathogenic microbes such as the species, including the emerging pathogen . Using a modified EUCAST protocol, the light-enhanced antifungal activity of the natural compound parietin was explored. The photoactivity was evaluated against three separate strains of five yeasts, and its molecular mode of action was analysed via several techniques, i.
View Article and Find Full Text PDFThe requirements for novel and innovative production systems expedite research on light emitting diode-based illumination in a life science context. In course of these rapid developments, the scientific community is in need of a consensus regarding to the characterization and presentation of the applied lighting conditions. This publication aims to establish a basic understanding of photon physics and propose guidelines for the conclusive usage of light related quantities.
View Article and Find Full Text PDFBackground: Ultraviolet (UV)-light-emitting diodes (UV-LEDs) are energy efficient and of special interest for the inactivation of micro-organisms. In the context of the coronavirus disease 2019 pandemic, novel UV technologies can offer a powerful alternative for effective infection prevention and control.
Methods: This study assessed the antimicrobial efficacy of UV-C LEDs on Escherichia coli, Pseudomonas fluorescens and Listeria innocua, as well as severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), human immunodeficiency virus-1 (HIV-1) and murine norovirus (MNV), dried on inanimate surfaces, based on European Standard EN 17272.
Background: With the steady increase of antibiotic resistance, several strategies have been proposed in the scientific community to overcome the crisis. One of many successful strategies is the re-evaluation of known compounds, which have been early discarded out of the pipeline, with state-of-the-art know-how. Xanthoepocin, a polyketide widespread among the genus Penicillium with an interesting bioactivity spectrum against gram-positive bacteria, is such a discarded antibiotic.
View Article and Find Full Text PDFFungi have developed a wide array of defense strategies to overcome mechanical injuries and pathogen infections. Recently, photoactivity has been discovered by showing that pigments isolated from produce singlet oxygen under irradiation. To test if this phenomenon is limited to dermocyboid Cortinarii, six colourful species belonging to different classical subgenera (i.
View Article and Find Full Text PDFAntimicrobial resistance is one of the biggest health and subsequent economic threat humanity faces. Next to massive global awareness campaigns, governments and NGOs alike stress the need for new innovative strategies to treat microbial infections. One of such innovative strategies is the photodynamic antimicrobial chemotherapy (PACT) in which the synergistic effects of photons and drugs are exploited.
View Article and Find Full Text PDFBackground: There is a wide ranging incidence of venous thromboembolism after surgery and it continues to be a major cause of morbidity after spinal procedures.This study's aim was to investigate the relationship between timing and administration of venous thromboembolism (VTE) pharmacologic chemoprophylaxis after spinal surgery and the resulting VTE and bleeding complications by reviewing current practices and outcomes at a high-volume single institution to better define opportunities for perioperative intervention to prevent VTE without increasing bleeding complications.
Methods: All patients who underwent elective one or two-stage lumbar spinal fusion procedures were identified.
Helium adsorbed on C(60)(+) and C(70)(+) exhibits phenomena akin to helium on graphite. Mass spectra suggest that commensurate layers form when all carbon hexagons and pentagons are occupied by one He each, but that the solvation shell does not close until 60 He atoms are adsorbed on C(60)(+), or 62 on C(70)(+). Molecular dynamics simulations of C(60)He(n)(+) at 4 K show that the commensurate phase is solid.
View Article and Find Full Text PDFThe electron ionization of helium droplets doped with methane clusters is investigated for the first time using high-resolution mass spectrometry. The dominant ion products ejected into the gas phase are the unprotonated (CH(4))(n)(+) cluster ions along with the protonated ions, CH(5)(+)(CH(4))(n-1). The mass spectra show clear evidence for magic numbers, which are broadly consistent with icosahedral shell closings.
View Article and Find Full Text PDFThe submersion of sodium clusters beyond a critical size in helium nanodroplets, which has recently been predicted on theoretical grounds, is demonstrated for the first time. Confirmation of a clear transition from a surface location, which occurs for alkali atoms and small clusters, to full immersion for larger clusters, is provided by identifying the threshold electron energy required to initiate Na(n) cluster ionization. On the basis of these measurements, a lower limit for the cluster size required for submersion, n ≥ 21, has been determined.
View Article and Find Full Text PDFWe report the observation of the ejection of electrons caused by collisions of excited atoms with ions, rather than neutrals, leading to the production of doubly charged ions. Doping superfluid He droplets with methyl iodide and exposing them to electrons enhances the formation of doubly charged iodine atoms at the threshold for the production of two metastable He atoms. These observations point toward a novel ionization process where doubly charged ions are produced by sequential Penning ionization.
View Article and Find Full Text PDFHelium nanodroplets are co-doped with C(60) and ammonia. Mass spectra obtained by electron ionization reveal cations containing ammonia clusters complexed with up to four C(60) units. The high mass resolution of Δm/m≈ 1/6000 makes it possible to separate the contributions of protonated, unprotonated and dehydrogenated ammonia.
View Article and Find Full Text PDFElectron attachment to the explosive trinitrotoluene (TNT) embedded in Helium droplets (TNT@He) generates the non-decomposed complexes (TNT)(n)(-), but no fragment ions in the entire energy range 0-12 eV. This strongly contrasts the behavior of single TNT molecules in the gas phase at ambient temperatures, where electron capture leads to a variety of different fragmentation products via different dissociative electron attachment (DEA) reactions. Single TNT molecules decompose by attachment of an electron at virtually no extra energy reflecting the explosive nature of the compound.
View Article and Find Full Text PDFNeutral hydrogen clusters are grown in ultracold helium nanodroplets by successive pickup of hydrogen molecules. Even-numbered hydrogen cluster cations are observed upon electron-impact ionization with and without attached helium atoms and in addition to the familiar odd-numbered H(n)(+). The helium matrix affects the fragmentation dynamics that usually lead to the formation of overwhelmingly odd-numbered H(n)(+).
View Article and Find Full Text PDFBackground And Purpose: Experimental studies suggested neurovascular compression of the brain stem as a cause of hypertension. The aim of our prospective study was to investigate the effect of microvascular decompression in patients with severe hypertension with neurovascular compression on blood pressure and central sympathetic nerve activity in the long-term.
Methods: Fourteen patients (4 males; mean age, 46+/-8 years) with essential hypertension underwent microvascular decompression of the brain stem.
We study inelastic collisions in a pure, trapped sample of Feshbach molecules made of bosonic cesium atoms in the quantum halo regime. We measure the relaxation rate coefficient for decay to lower-lying molecular states and study the dependence on scattering length and temperature. We identify a pronounced loss minimum with varying scattering length along with a further suppression of loss with decreasing temperature.
View Article and Find Full Text PDFIn order to investigate the effect of different immunosuppressive regimens and the time interval between transplantation and pregnancy on long-term outcome, we performed a case-control study in pregnant renal allograft recipients. Eighty-one pregnancies of kidney transplanted recipients were identified [cyclosporine (CYA): n = 40; azathioprine (AZA): n = 41]. Controls were matched with respect to important prognostic factors.
View Article and Find Full Text PDFAlthough the modern technique of otosclerosis surgery introduced by John Shea on 1st May 1956 has already been used throughout the world for almost fifty years it has not been possible to bring in line the differing opinions of surgeons concerning the optimum operation technique, the problems of the fenestration of the footplate, material and form of stapes replacement prosthetics and kind and place of their anchoring on the incus. Moreover, there is considerable disagreement among surgeons on a realistic evaluation of the findings of early and late results. During the last few decades otosclerosis surgery has become the hallmark of modern ear surgery and has been practiced in very highly specialized departments as well as in outpatient departments.
View Article and Find Full Text PDFBackground: Renal anemia is an important determinant for left ventricular hypertrophy in dialysis patients and an independent prognosis parameter for the cardiovascular survival in dialysis patients. In addition, an autonomic dysfunction is associated with the uremic state and influences the cardiovascular risk in patients with end-stage renal disease (ESRD).
Methods: We investigated in this prospective longitudinal study the effect of hemoglobin normalization by a chronic treatment with recombinant human erythropoietin (rhEPO) on cardiovascular prognosis parameters in 23 patients on chronic hemodialysis with renal anemia (hemoglobin concentration < or =10.
Eur J Clin Invest
June 2004
Background: Preeclampsia has been shown to constitute a state of sympathetic overactivity. However, it remains unclear if the sympathetic activity precedes preeclampsia or represents only a secondary phenomenon. To further investigate this issue, we performed a prospective study in pregnant women considered to be at increased risk for preeclampsia owing to preeclampsia during a preceding pregnancy.
View Article and Find Full Text PDFIntroduction: Blockade of the renin-angiotensin system (RAS) by ACE inhibitors has been demonstrated to reduce total mortality in cardiovascular diseases. This advantage was attributed in part to changes of autonomic cardiovascular control, exemplified by an increase of heart rate variability (HRV) and baroreflex gain (BRG). We sought to assess the effects of the angiotensin type 1 (AT1) receptor blocker eprosartan on HRV and BRG.
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