Professor Sidney Barski (1918–2018) Albrecht, J.
British journal of dermatology (1951),
January 2019, 2019-Jan, 2019-01-00, 20190101, Letnik:
180, Številka:
1
Journal Article
It′s no sacrifice: Alkynes have been used as direct precursors to sulfur ylides under gold or platinum π‐acid catalysis in an atom‐economic manner. An intramolecular redox reaction between an alkyne ...group with a tethered sulfoxide unit generates a sulfur ylide, which undergoes 2,3‐sigmatropic rearrangement. Acyclic substrates are cycloisomerized to afford functionalized dihydrothiophenones (see scheme) and dihydrothiopyranones.
Chemotherapy-induced peripheral neuropathy (CIPN) is a disruptive and persistent side effect of cancer treatment with paclitaxel. Recent reports showed that paclitaxel treatment results in the ...activation of Toll-like receptor 4 (TLR4) signaling and increased expression of monocyte chemoattractant protein 1 (MCP-1) in dorsal root ganglion cells. In this study, we sought to determine whether an important consequence of this signaling and also a key step in the CIPN phenotype was the recruitment and infiltration of macrophages into dorsal root ganglia (DRG). Here, we show that macrophage infiltration does occur in a time course that matches the onset of the behavioral CIPN phenotype in Sprague-Dawley rats. Moreover, depletion of macrophages by systemic administration of liposome-encapsulated clodronate (clophosome) partially reversed behavioral signs of paclitaxel-induced CIPN as well as reduced tumor necrosius factor α expression in DRG. Intrathecal injection of MCP-1 neutralizing antibodies reduced paclitaxel-induced macrophage recruitment into the DRG and also blocked the behavioral signs of CIPN. Intrathecal treatment with the TLR4 antagonist lipopolysaccharide-RS (LPS-RS) blocked mechanical hypersensitivity, reduced MCP-1 expression, and blocked the infiltration of macrophages into the DRG in paclitaxel-treated rats. The inhibition of macrophage infiltration into DRG after paclitaxel treatment with clodronate or LPS-RS prevented the loss of intraepidermal nerve fibers (IENFs) observed after paclitaxel treatment alone. These results are the first to indicate a mechanistic link such that activation of TLR4 by paclitaxel leads to increased expression of MCP-1 by DRG neurons resulting in macrophage infiltration to the DRG that express inflammatory cytokines and the combination of these events results in IENF loss and the development of behavioral signs of CIPN.
This paper shows that activation of innate immunity by paclitaxel results in a sequence of signaling events that results in the infiltration of the dorsal root ganglia by activated macrophages. Macrophages appear to drive the development of behavioral hypersensitivity and the loss of distal epidermal nerve fibers, and hence play an important role in the mechanism of paclitaxel-related neuropathy.
Background and aims Northern peatlands are large repositories of carbon. Peatland vascular plant community composition has been functionally associated to a set of biogeochemical processes such as ...carbon cycling. Yet, we do not fully understand to what extent vascular plant functional types (PFTs) affect the quality of dissolved organic matter, and if there is any feedback on soil microbial activity. Methods Using a longer-term plant removal experiment in a boreo-nemoral peatland in Southern Sweden, we relate the dominance of different vascular plant functional types (i.e. ericoids and graminoids) to the chemistry of the dissolved organic matter (DOM) and microbial enzymatic activities (fluorescein diacetate hydrolysis, FDA). Results Our results show that PFTs modifies the composition of DOM moieties, with a decrease of low molecular weight organic compounds after vascular plant removal. The decrease of enzymatic activity by up to 68 % in the plant removal plots suggests a reduction in DOM mineralization in the absence of vascular plants. Conclusions Our results show that plant-derived low molecular organic compounds enhance peatland microbial activity, and suggest that an increase of vascular plant cover in response to climate change can potentially destabilize the OM in peatlands, leading to increased carbon losses.
Long‐term efficacy: the new gold standard? Gerdes, S.; Albrecht, J.
British journal of dermatology (1951),
December 2021, 2021-12-00, 20211201, Letnik:
185, Številka:
6
Journal Article
Recenzirano
Odprti dostop
Linked Article: Papp et al. Br J Dermatol 2021; 185:1135–1145.
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•Sr-doped CaMnO3 can provide specific TCES over 750kJ/kg between 500 and 900°C.•Over 50% of TCES in Sr-doped CaMnO3 can be sustained through endothermic reaction.•Kinetic measurements ...indicate challenges in reaching TCES thermodynamic limits for CSP.
Thermochemical energy storage (TCES) using redox cycles of reducible perovskite oxides can potentially provide higher specific energy capacities and storage temperatures than molten-salt systems for large-scale energy storage in concentrating solar power (CSP) and other applications. Perovskites from earth abundant cations, such as CaMnO3, are needed for cost-effective solutions, but such materials must demonstrate favorable thermodynamics for high specific TCES (chemical+sensible) and favorable kinetics for heat-driven reduction and exothermic re-oxidation in the redox cycle. This paper explores the thermodynamics and kinetics of Ca1-xSrxMnO3-δ(x=0.05and0.1) particles for TCES redox cycles where the particles are heated and reduced in N2 (PO2≈10-4bar) to high temperatures TH up to 1000°C in a solid-particle solar receiver. Chemical and sensible energy stored in the reduced perovskite particles is released as needed to a power cycle via re-oxidation and cooling of the material. Variation of oxygen non-stoichiometry (δ) of Ca1-xSrxMnO3-δ with temperature and PO2 is measured via thermogravimetric analysis. Reaction enthalpy for reduction and re-oxidation is determined by fitting the variation of δ with temperature and PO2 to a two-reaction point defect model. The fits compare favorably to differential scanning calorimetry with overall reaction enthalpies varying significantly with δ. For CSP applications, limited time in the solar receiver for perovskite reduction requires fast kinetics to achieve high specific TCES. Once the material is characterized thermodynamically, kinetic measurements for particle reduction and re-oxidation are performed in a packed-bed reactor to assess rates of O2 release and uptake at various temperatures and PO2 with particles of diameter between250and425μm. Packed-bed experiments indicate that the low values of A-site Sr-doping stabilize the CaMnO3-δ structure and allow large δ at high temperatures and PO2≈10-4bar. In these time-limited redox cycling experiments between 500and900°C, mass-transfer limited kinetics allows the Ca0.95Sr0.05MnO3-δ to reach a specific TCES of 620kJkg−1, which is 78% of the equilibrium limit of 791kJkg−1. X-ray diffraction after 1000 redox cycles showed that the Ca1-xSrxMnO3-δ particles have excellent phase stability for the desired redox conditions.
Gallium antimonide (GaSb) is a III-V semiconductor of technological interest for low-power, high-mobility field-effect transistors, as well as for mid-wave infrared detectors. In such devices, GaSb ...interfaces with other III–V semiconductors with different lattice constants that can induce strain in the GaSb layers. Two dominant limiting factors in hot carrier relaxation are the intra-valley and the inter-valley electron–phonon (e-ph) scattering. In GaSb, these are sensitive to the
Γ
–
L
energy ordering, which depend intimately on the strain. Here, we report ab initio calculations of electronic structure, phonon dispersion, e-ph scattering and relaxation times for GaSb as a function of strain. As observed previously for other group IV and III-V semiconductors, our results show strong anisotropy, a strong contribution from LO phonons, and the need to go beyond the deformation potential scattering. For GaSb, the main finding is that a compressive strain between 0.4% and 0.6% converts GaSb from a direct-bandgap semiconductor to an indirect-bandgap semiconductor, with dramatic changes in the competing scattering rates and carrier relaxation times.
Summary
Context
Many physicians monitor liver function tests during terbinafine therapy.
Objectives
To evaluate the symptoms of published cases of terbinafine‐associated severe drug‐induced liver ...injury (DILI) to assess the utility of laboratory monitoring.
Data sources
We based our search on the LiverTox database of the National Institutes of Health, but we also searched both PubMed and Embase. In addition, we hand searched the references of the papers we found.
Study selection
All reports of patients with DILI on terbinafine and with reported clinical symptoms, or absence thereof, were evaluated.
Data extraction
Two independent reviewers (J.A. and O.N.K.) assessed articles for eligibility of inclusion, and collected and evaluated the data.
Data synthesis
Thirty‐eight papers fulfilled the inclusion criteria, with reports of 69 symptomatic patients. The mean duration of terbinafine treatment until onset of symptoms was 30·2 days (range 5–84). Symptoms in order of frequency were jaundice, flu‐like symptoms, dark urine and pruritus. Patients experienced symptoms for a mean and median of 14·8 and 16 days, respectively (range 0–42) until seeking medical attention.
Conclusions
Patients who had DILI were symptomatic, usually with jaundice, abdominal pain and general malaise, but also with severe pruritus. No asymptomatic patient was identified through laboratory screening. The timeline of DILI onset varies significantly, but most cases occur between 4 and 6 weeks. There was no time point at which monitoring was meaningful, and we do not recommend monitoring of liver function tests on terbinafine; however, patients should be advised to discontinue treatment and look for medical care when symptoms of DILI occur.
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