23 research outputs found
Hand-selective visual regions represent how to grasp 3D tools: Brain decoding during real actions
Most neuroimaging experiments that investigate how tools and their actions are represented in the brain use visual paradigms where tools or hands are displayed as 2D images and no real movements are performed. These studies discovered selective visual responses in occipitotemporal and parietal cortices for viewing pictures of hands or tools, which are assumed to reflect action processing, but this has rarely been directly investigated. Here, we examined the responses of independently visually defined category-selective brain areas when participants grasped 3D tools (N = 20; 9 females). Using real-action fMRI and multivoxel pattern analysis, we found that grasp typicality representations (i.e., whether a tool is grasped appropriately for use) were decodable from hand-selective areas in occipitotemporal and parietal cortices, but not from tool-, object-, or body-selective areas, even if partially overlapping. Importantly, these effects were exclusive for actions with tools, but not for biomechanically matched actions with control nontools. In addition, grasp typicality decoding was significantly higher in hand than tool-selective parietal regions. Notably, grasp typicality representations were automatically evoked even when there was no requirement for tool use and participants were naive to object category (tool vs nontools). Finding a specificity for typical tool grasping in hand-selective, rather than tool-selective, regions challenges the long-standing assumption that activation for viewing tool images reflects sensorimotor processing linked to tool manipulation. Instead, our results show that typicality representations for tool grasping are automatically evoked in visual regions specialized for representing the human hand, the primary tool of the brain for interacting with the world
Photoelectrochemical Sensing of Hydrogen Peroxide on Hematite
International audienceDue to its abundance and chemical stability, hematite (α-Fe 2 O 3) is a promising n-type semiconductor photoelectrode. This is particularly true in the frame of the rapidly developing area of photoelectrochemical (PEC) sensing, where the short excited-state lifetime and the small carrier diffusion length of hematite can be beneficially employed. On the other hand, H 2 O 2 is an essential molecule for biological, environmental and industrial applications. In this article, we report a simple method to prepare photoelectroactive hematite layers on fluorine-doped SnO 2 (FTO) and we use these surfaces for H 2 O 2 PEC sensing. The so-created sensors allow to reliably detect H 2 O 2 down to a sub-µM concentration with a large linear range and a good reusability. H 2 O 2 is a crucial molecule. First, it is a marker for oxidative stress and a major factor of pathophysiological complications in serious diseases. [1,2] H 2 O 2 is also present in the natural environment [3] and commonly employed as a reagent in paper, textile or food industry. Hence, fast and accurate monitoring of H 2 O 2 is of great interest to medicine, environmental and industrial processing. Analytical protocols based on chromatography, [4] titration, [5] spectrophotometry, [6] fluorescence, [7] chemiluminescence, [8] and electrochemistry [9,10] have been used to detect this molecule and the development of H 2 O 2 sensors attracts considerable attention. [9,11] Photoelectrochemical (PEC) sensing is based on the photoinduced charge transfer at a semiconductor/liquid interface. It is a rather new and rapidly-developing research area which sensing combines aspects of electrochemical and optical sensing. [12,13] PEC sensing decouples excitation (light) and detection (electrochemical) signals, which is expected to significantly increase the signal-to-noise ratio with respect to electrochemical sensing. [13] Besides, it is also promising because it enables 2D reaction confinement on the transducer surface (i.e. on the photoelectrode) [14,15] which can be useful for electrode reuse [16,17] or for the design of multiplexed arrays. [18,19] So far, PEC sensing has been mainly employed for the detection of biological macromolecules, [20] in immuno-[21] or apta-[22] assays and has also been explored for the detection of small organic molecules such as antioxidants [23] or glucose. [24,25] While H 2 O 2 is a widely-employed hole scavenger in the field of energy-related photoelectrochemical research (typically used to probe the upper performance of water-splitting photoanodes), [26,27] the PEC sensing of H 2 O 2 has been only reported on TiO 2 , [28-30] WO 3 , [31] ZnO, [32,33] BiVO 4 , [34,35] and Si [36]-based photoanodes and on Cu 2 O, [37] CuO, [38] CdS, [39] and CuInS 2 [40]-based photocathodes. Hematite (α-Fe 2 O 3) is a promising photoanode material due to its great abundance, low-cost, chemical stability and its high theoretical photoconversion efficiency. [41,42] Nevertheless, it also has a short excited-state lifetime and a small hole diffusion length. This is a severe drawback for energy-related applications [41,42] but can be a great advantage for the design of PEC sensor arrays activated by micrometer-sized spots of light. [15,17] Hematite photoanodes have been previously employed for the PEC sensing of biological macromolecules, [43,44] neurotransmitters, [17] endocrine disruptors, [45,46] glucose, [25,44] inorganic pollutants, [47] and metal cations. [48] In this paper, we report the preparation of hematite photoanodes by a convenient spin-coating/annealing method and the use of these surfaces for H 2 O 2 PEC sensing. Figure 1. a) Scheme showing the method used to deposit hematite on FTO. b) Colored SEM image showing a cross-section of the hematite deposited on FTO. c) SEM image showing a top view of the hematite coating on FTO. d) XRD pattern of the deposited layer (black line), the red lines indicate the peaks position and relative intensity for hematite (ICSD #15840). e) High-resolution TEM image of the prepared hematite layer, the distance between the (210) planes is indicated. f) [12 1] zone axis SAED patterns recorded on hematite. Our hematite precursor is poly(vinylferrocene) (pvf), a Fe-containing polymer, dissolved in tetrahydrofuran (THF), which was spin-coated onto FTO slides and subsequently annealed, as shown in Figure 1a. A similar approach was previously employed by our group, however, with a low annealing temperature (300 °C) in order to deposit amorphous catalytic FeO x layers. [49] In the present work, we wanted to assess the feasibility of growing semiconductor films, we thus employed a higher annealin
Boosting the Performance of BiVO 4 Prepared through Alkaline Electrodeposition with an Amorphous Fe Co-catalyst
International audienceBiVO4 is a promising n‐type semiconductor for water‐splitting photoelectrochemical cells. We report here a new method to prepare BiVO4 photoanodes that is based on an alkaline electrodeposition process, which avoids chemical etching of Bi. In addition, we present a simple and general method to prepare coatings of amorphous FeOx that behave as a co‐catalyst on our BiVO4 material, improving the water splitting photocurrent
A New Label-Free Approach to Glioblastoma Cancer Stem Cell Sorting and Detection
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Characteristics of thrombocytopenia, anasarca, fever, reticulin fibrosis and organomegaly syndrome: a retrospective study from a large Western cohort
International audienceIdiopathic multicentric Castleman disease (iMCD) is a non-clonal inflammatory lymphoproliferative disorder of unknown origin. Recently, TAFRO syndrome (thrombocytopenia, anasarca, fever, reticulin fibrosis and organomegaly) emerged as a singular variant of iMCD in Asia and was associated with a severe course and a poor outcome. The present study describes the first large Western cohort of TAFRO syndrome patients (n = 25) meeting the All Japan TAFRO Syndrome Research Group diagnostic criteria. Characteristics of TAFRO patients were compared to iMCD-not otherwise specified (iMCD-NOS) patients used as a control group (n = 43). Our results show that despite baseline characteristics in accordance with previously reported series, Western TAFRO syndrome patients do not appear to present with a worse outcome than iMCD-NOS patients. There were no significant differences between the two groups regarding treatment choice, response to rituximab (71% vs. 67%) or tocilizumab (69% vs. 91%) in TAFRO and iMCD-NOS, respectively. The two-year overall survival was above 95% in both groups. Limits of inclusion and exclusion criteria for TAFRO definition are also discussed. Our findings raise the question of the singularity of the TAFRO entity in Western countries. The data should promote further research using unsupervised models to identify markers of disease severity in Western cohorts of iMCD patients
Interruption versus continuation of trabectedin in patients with soft-tissue sarcoma (T-DIS): a randomised phase 2 trial
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Paclitaxel Given Once Per Week With or Without Bevacizumab in Patients With Advanced Angiosarcoma: A Randomized Phase II Trial
International audiencePurpose The aim of this randomized, phase II trial was to explore the activity and safety of adding bevacizumab to paclitaxel once per week in treatment of angiosarcomas (AS). Methods Patients were treated with paclitaxel alone (90 mg/m 2 per week for six cycles of 28 days each; arm A) or with paclitaxel combined with bevacizumab (10 mg/kg once every 2 weeks; arm B). In the combination treatment arm, bevacizumab was administered after the six cycles of chemotherapy as maintenance therapy (15 mg/kg once every 3 weeks) until intolerance or progression occurred. Stratification factors were superficial versus visceral AS and de novo versus radiation-induced AS. The primary end point was the 6-month progression-free survival (PFS) rate, which was based on RECIST, version 1.1. Statistical assumptions were P0 = 20%, P1 = 40%, a = 10%, and b = 20%. P0 was the PFS rate at 6 months defining inactive drug, and P1 was the PFS rate at 6 months defining promising drug. Results A total of 52 patients were enrolled, and 50 were randomly assigned in 14 centers. The most common primary sites were the breast (49%) and skin (12%). There were 17 (34%) visceral and 24 (49%) radiation-induced AS. The performance status was 0 in 24 patients (49%) and 1 in the remaining 25 patients (51%). The median follow-up time was 14.5 months. Both treatment regimens were considered active, with 6-month PFS rates of 54% (14 of 26) in arm A and 57% (14 of 24) in arm B. The median overall survival rates were 19.5 months in arm A and 15.9 months in arm B. Toxicity was higher with the combination arm and included one fatal drug-related toxicity (intestinal occlusion). Conclusion The primary objective was met in both treatment arms. However, the present data do not support additional clinical investigation of combined paclitaxel/bevacizumab for the treatment of advanced AS
Circulating tumor DNA in cervical cancer patients.
<p>Abbreviations: FIGO: International Federation of Gynecology and Obstetrics; SCC: squamous cell carcinoma associated antigen; NA: not available;</p>*<p>Repeated sequences: Homology with the centromeric sequences of various chromosomes.</p