191 research outputs found

    Temporomandibular Joint Disorder Complaints in Tinnitus: Further Hints for a Putative Tinnitus Subtype

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    OBJECTIVE: Tinnitus is considered to be highly heterogeneous with respect to its etiology, its comorbidities and the response to specific interventions. Subtyping is recommended, but it remains to be determined which criteria are useful, since it has not yet been clearly demonstrated whether and to which extent etiologic factors, comorbid states and interventional response are related to each other and are thus applicable for subtyping tinnitus. Analyzing the Tinnitus Research Initiative Database we differentiated patients according to presence or absence of comorbid temporomandibular joint (TMJ) disorder complaints and compared the two groups with respect to etiologic factors. METHODS: 1204 Tinnitus patients from the Tinnitus Research Initiative (TRI) Database with and without subjective TMJ complaints were compared with respect to demographic, tinnitus and audiological characteristics, questionnaires, and numeric ratings. Data were analysed according to a predefined statistical analysis plan. RESULTS: Tinnitus patients with TMJ complaints (22% of the whole group) were significantly younger, had a lower age at tinnitus onset, and were more frequently female. They could modulate or mask their tinnitus more frequently by somatic maneuvers and by music or sound stimulation. Groups did not significantly differ for tinnitus duration, type of onset (gradual/abrupt), onset related events (whiplash etc.), character (pulsatile or not), hyperacusis, hearing impairment, tinnitus distress, depression, quality of life and subjective ratings (loudness etc.). CONCLUSION: Replicating previous work in tinnitus patients with TMJ complaints, classical risk factors for tinnitus like older age and male gender are less relevant in tinnitus patients with TMJ complaints. By demonstrating group differences for modulation of tinnitus by movements and sounds our data further support the notion that tinnitus with TMJ complaints represents a subgroup of tinnitus with clinical features that are highly relevant for specific therapeutic management

    Foraging Behavior under Starvation Conditions Is Altered via Photosynthesis by the Marine Gastropod, Elysia clarki

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    It has been well documented that nutritional state can influence the foraging behavior of animals. However, photosynthetic animals, those capable of both heterotrophy and symbiotic photosynthesis, may have a delayed behavioral response due to their ability to photosynthesize. To test this hypothesis we subjected groups of the kleptoplastic sea slug, Elysia clarki, to a gradient of starvation treatments of 4, 8, and 12 weeks plus a satiated control. Compared to the control group, slugs starved 8 and 12 weeks displayed a significant increase in the proportion of slugs feeding and a significant decrease in photosynthetic capability, as measured in maximum quantum yield and [chl a]. The 4 week group, however, showed no significant difference in feeding behavior or in the metrics of photosynthesis compared to the control. This suggests that photosynthesis in E. clarki, thought to be linked to horizontally-transferred algal genes, delays a behavioral response to starvation. This is the first demonstration of a link between photosynthetic capability in an animal and a modification of foraging behavior under conditions of starvation

    Photochemical versus Thermal Synthesis of Cobalt Oxyhydroxide Nanocrystals

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    Photochemical methods facilitate the generation, isolation, and study of metastable nanomaterials having unusual size, composition, and morphology. These harder-to-isolate and highly reactive phases, inaccessible using conventional high-temperature pyrolysis, are likely to possess enhanced and unprecedented chemical, electromagnetic, and catalytic properties. We report a fast, low-temperature and scalable photochemical route to synthesize very small (~3 nm) monodisperse cobalt oxyhydroxide (Co(O)OH) nanocrystals. This method uses readily and commercially available pentaamminechlorocobalt(III) chloride, [Co(NH3) 5Cl]Cl2, under acidic or neutral pH and proceeds under either near-UV (350 nm) or Vis (575 nm) illumination. Control experiments showed that the reaction proceeds at competent rates only in the presence of light, does not involve a free radical mechanism, is insensitive to O 2, and proceeds in two steps: (1) Aquation of [Co(NH3) 5Cl] 2+ to yield [Co(NH3) 5(H2O)] 3+, followed by (2) slow photoinduced release of NH3 from the aqua complex. This reaction is slow enough for Co(O)OH to form but fast enough so that nanocrystals are small (ca. 3 nm). The alternative dark thermal reaction proceeds much more slowly and produces much larger (~250 nm) polydisperse Co(O)OH aggregates. UV-Vis absorption measurements and ab initio calculations yield a Co(O)OH band gap of 1.7 eV. Fast thermal annealing of Co(O)OH nanocrystals leads to Co3O4 nanocrystals with overall retention of nanoparticle size and morphology. Thermogravimetric analysis shows that oxyhydroxide to mixed-oxide phase transition occurs at significantly lower temperatures (up to T = 64 degrees C) for small nanocrystals compared with the bulk

    Microplastic-Associated Biofilms: A Comparison of Freshwater and Marine Environments

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    Microplastics (<5 mm particles) occur within both engineered and natural freshwater ecosystems, including wastewater treatment plants, lakes, rivers, and estuaries. While a significant proportion of microplastic pollution is likely sequestered within freshwater environments, these habitats also constitute an important conduit of microscopic polymer particles to oceans worldwide. The quantity of aquatic microplastic waste is predicted to dramatically increase over the next decade, but the fate and biological implications of this pollution are still poorly understood. A growing body of research has aimed to characterize the formation, composition, and spatiotemporal distribution of microplastic-associated (“plastisphere”) microbial biofilms. Plastisphere microorganisms have been suggested to play significant roles in pathogen transfer, modulation of particle buoyancy, and biodegradation of plastic polymers and co-contaminants, yet investigation of these topics within freshwater environments is at a very early stage. Here, what is known about marine plastisphere assemblages is systematically compared with up-to-date findings from freshwater habitats. Through analysis of key differences and likely commonalities between environments, we discuss how an integrated view of these fields of research will enhance our knowledge of the complex behavior and ecological impacts of microplastic pollutants

    Idiopathic pulmonary fibrosis is strongly associated with productive infection by herpesvirus saimiri

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    Idiopathic pulmonary fibrosis is a fatal disease without effective therapy or diagnostic test. To investigate a potential role for c�herpesviruses in this disease, 21 paraffin-embedded lung biopsies from patients diagnosed with idiopathic pulmonary fibrosis and 21 lung biopsies from age-matched controls with pulmonary fibrosis of known etiology were examined for a series of c�herpesviruses’ DNA/RNA and related proteins using in situ hybridization and reverse transcriptase-polymerase chain reaction (RT-PCR)-based methods. We detected four proteins known to be in the genome of several c�herpesviruses (cyclin D, thymidylate synthase, dihydrofolate reductase, and interleukin-17) that were strongly co-expressed in the regenerating epithelial cells of each of the 21 idiopathic pulmonary fibrosis cases and not in the benign epithelia of the controls. Among the c� herpesviruses, only herpesvirus saimiri expresses all four of these ‘pirated’ mammalian proteins. We found herpesvirus saimiri DNA in the regenerating epithelial cells of 21/21 idiopathic pulmonary fibrosis cases using four separate probe sets but not in the 21 controls. RT-PCR showed that the source of the cyclin D RNA in active idiopathic pulmonary fibrosis was herpesvirus saimiri and not human. We cloned and sequenced part of genome corresponding to the DNA polymerase herpesvirus saimiri gene from an idiopathic pulmonary fibrosis sample and it matched 100% with the published viral sequence. These data are consistent with idiopathic pulmonary fibrosis representing herpesvirus saimiri-induced pulmonary fibrosis. Thus, treatment directed against viral proliferation and/or viral-associated proteins may halt disease progression. Further, demonstration of the viral nucleic acids or proteins may help diagnose the disease

    Hydrogen and nitrogen codoping of anatase TiO<sub>2</sub> for efficiency enhancement in organic solar cells

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    TiO2 has high chemical stability, strong catalytic activity and is an electron transport material in organic solar cells. However, the presence of trap states near the band edges of TiO2 arising from defects at grain boundaries significantly affects the efficiency of organic solar cells. To become an efficient electron transport material for organic photovoltaics and related devices, such as perovskite solar cells and photocatalytic devices, it is important to tailor its band edges via doping. Nitrogen p-type doping has attracted considerable attention in enhancing the photocatalytic efficiency of TiO2 under visible light irradiation while hydrogen n-type doping increases its electron conductivity. DFT calculations in TiO2 provide evidence that nitrogen and hydrogen can be incorporated in interstitial sites and possibly form NiHi, NiHO and NTiHi defects. The experimental results indicate that NiHi defects are most likely formed and these defects do not introduce deep level states. Furthermore, we show that the efficiency of P3HT:IC60BA-based organic photovoltaic devices is enhanced when using hydrogen-doping and nitrogen/hydrogen codoping of TiO2, both boosting the material n-type conductivity, with maximum power conversion efficiency reaching values of 6.51% and 6.58%, respectively, which are much higher than those of the cells with the as-deposited (4.87%) and nitrogen-doped TiO2 (4.46%).</p

    Direct and Indirect Parametrization of a LocalizedModel for the Mountain Pine Beetle – Lodgepole Pine System

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    The dynamic interaction between mountain pine beetles (MPB) and one of its hosts is reviewed briefly. The ‘local’ projection of a partial differential equation model describing this interaction is employed in model parameter estimation. Methods and assumptions for estimating non-fitted parameter values are given. Assigning values to non-fitted parameters, direct and indirect parametrization techniques are employed to estimate remaining parameter values. The indirect method is quickly and easily applied to many data sets but requires some assumptions and model simplifications. The direct method requires fewer assumptions but is computationally intensive. The results of these two techniques are compared and evaluated
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