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Frederick Epstein opublikował 1 rok, 3 miesiące temu
At last, the secondary organic release of a dynamic formed cake layer was proved to be limited especially for living algae cells.Manganese(IV) oxides, and more especially birnessite, rank among the most efficient metal oxides for As(III) oxidation and subsequent sorption, and thus for arsenic immobilization. Efficiency is limited however by the precipitation of low valence Mn (hydr)oxides at the birnessite surface that leads to its passivation. The present work investigates experimentally the influence of chelating agents on this oxidative process. Specifically, the influence of sodium pyrophosphate (PP), an efficient Mn(III) chelating agent, on As(III) oxidation by birnessite was investigated using batch experiments and different arsenic concentrations at circum-neutral pH. In the absence of PP, Mn(II/III) species are continuously generated during As(III) oxidation and adsorbed to the mineral surface. Field emission-scanning electron microscopy, synchrotron-based X-ray diffraction and Fourier transform infrared spectroscopy indicate that manganite is formed, passivating birnessite surface and thus hampering the oxidative process. In the presence of PP, generated Mn(II/III) species form soluble complexes, thus inhibiting surface passivation and promoting As(III) conversion to As(V) with PP. Enhancement of As(III) oxidation by Mn oxides strongly depends on the affinity of the chelating agent for Mn(III) and from the induced stability of Mn(III) complexes. Compared to PP, the positive influence of oxalate, for example, on the oxidative process is more limited. The present study thus provides new insights into the possible optimization of arsenic removal from water using Mn oxides, and on the possible environmental control of arsenic contamination by these ubiquitous nontoxic mineral species.
Little is known about the stability of public drug treatment in the United States to deliver services in an era of expansion of public insurance. Guided by organizational theories, we examined the role of program size, and performance (i.e., rates of treatment initiation and engagement) on discontinuing services in one of the largest treatment systems in the United States.
This study relied on multi-year (2006-2014) administrative data of 249,029 treatment admission episodes from 482 treatment programs in Los Angeles County, CA. We relied on survival regression analysis to identify associations between program size, treatment initiation (wait time) and engagement (retention and completion rates) and discontinuing services in any given year. We examined program differences between discontinued versus sustained services in pre- and post-expansion periods.
Sixty-two percent of programs discontinued services at some point between 2006 and 2014. Program size and rates of treatment retention were negatively aatment system. Because more than 70% of programs in this system are small, it is critical to support their capacity to sustain services to reduce existing disparities in access to care. We discuss the implications of these findings for system evaluation and for responding to public health crises.
Immune checkpoint inhibitors (ICIs) are associated with immune-related adverse events (irAEs) that occur as a consequence of enhanced immune response due to T-cell activation. The objective of this retrospective study was to investigate the association between irAEs and disease outcome in patients with recurrent/metastatic (R/M) head and neck squamous cell carcinoma (HNSCC).
This study included 89 patients with R/M HNSCC who were treated with nivolumab in our center from October 2015 to January 2020. Overall survival (OS) and post-progression survival (PPS) were calculated from the date of nivolumab initiation or from the date of progression on nivolumab respectively to the date of death or censored at the last date of follow up.
Twenty-four patients (27%) developed irAEs, with more common thyroiditis (N=13, 14.6%). ORR did not differ between patients with irAEs (29.2%) and patients without irAEs (21.9%, p=0.576). Median PFS was similar between the two groups (3.1months for patients with irAEs vs. 2.6months for patients without irAEs, p=0.412). Median OS was significantly longer in patients with irAEs (17.9 vs. 6.3months in patients without irAEs, log-rank p=0.004). Additionally, median PPS was significantly improved in patients who developed irAEs (10.2months vs. 2.8months for patients without irAEs, log-rank p=0.001). In multivariate analysis, the development of irAEs and response to nivolumab were shown to be independent prognostic factors for favorable OS and PPS.
The development of irAEs is a strong predictor of improved survival in patients with advanced HNSCC treated with nivolumab.
The development of irAEs is a strong predictor of improved survival in patients with advanced HNSCC treated with nivolumab.Genome-wide association studies (GWAS) have identified genetic susceptibility loci for a variety of autoimmune and inflammatory diseases. These studies confirm the fundamental genetic basis of individual autoimmune diseases, and also point to shared etiological mechanisms across the spectrum of autoimmunity. While hundreds of genetic loci have been implicated in autoimmune diseases, the translation of individual susceptibility loci into specific molecular mechanisms for individual diseases remains difficult. This review highlights recent advances in the genetics of autoimmune disease, and the emerging use of epigenetic techniques to identify pathogenic cell types and causal molecular mechanisms of autoimmunity.Alongside difficulties with communication and social interaction, autism is often accompanied by unusual sensory and perceptual experiences including enhanced visual performance on tasks that involve separating local parts from global context. This superiority may be the result of atypical integrative processing, involving feedback and lateral connections between visual neurons. The current study investigated the integrity of these connections in autistic adults by examining two psychophysics tasks that rely on these processes – collinear facilitation and contour integration. The relative contribution of feedback and lateral connectivity was studied by altering the timing of the target relative to the flankers in the collinear facilitation task, in 16 autistic and 16 non-autistic adults. There were no significant differences in facilitation between the autistic and non-autistic groups, indicating that for this task and participant sample, lateral and feedback connectivity appear relatively intact in autistic individuals. Contour integration was examined in a different group of 20 autistic and 18 non-autistic individuals, for open and closed contours to assess the closure effect (improved detection of closed compared to open contours). Autistic individuals showed a reduced closure effect at both short (150 ms) and longer (500 ms) stimulus presentation durations that was driven by better performance of the autistic group for the open contours. These results suggest that reduced closure in a simple contour detection paradigm is unlikely to be due to slower global processing. Reduced closure has implications for understanding sensory overload by contributing to reduced figure-ground segregation of salient visual features.
Neurodegenerative diseases like Parkinson’s disease often take several years before they can be diagnosed reliably based on clinical grounds. Imaging techniques such as MRI are used to detect anatomical (structural) pathological changes. However, these kinds of changes are usually seen only late in the development. The measurement of functional brain activity by means of [
F]fluorodeoxyglucose positron emission tomography (FDG-PET) can provide useful information, but its interpretation is more difficult. The scaled sub-profile model principal component analysis (SSM/PCA) was shown to provide more useful information than other statistical techniques. Our objective is to improve the performance further by combining SSM/PCA and prototype-based generalized matrix learning vector quantization (GMLVQ).
We apply a combination of SSM/PCA and GMLVQ as a classifier. In order to demonstrate the combination’s validity, we analyze FDG-PET data of Parkinson’s disease (PD) patients collected at three different neuroimaysis we conclude that the first steps towards a diagnostic support system have been taken successfully.
We have shown that the presented combination of SSM/PCA and GMLVQ can provide useful means to assess and better understand characteristic differences in FDG-PET data from PD patients and HCs. Based on the assessments by medical experts and the results of our computational analysis we conclude that the first steps towards a diagnostic support system have been taken successfully.
In cardiac medical imaging, the extraction and segmentation of the part of interest is the key to the diagnosis of heart disease. Due to irregular diastole and contraction, magnetic resonance imaging (MRI) images have poorly defined boundaries, and traditional segmentation algorithms have poor performance. In this paper, a cardiac MRI segmentation technique using convolutional neural network and image saliency is suggested.
The convolutional neural network is used for detecting target area, filter out the ribs, muscles and the other parts of the anatomy where the contrast is not clearly defined. It can also be used to extract the region of interest (ROI), and compute the contrast of the ROI in order to improve clarity of the heart tissue within the ROI. The cardiac image diagnosis is performed using the obtained saliency image and compared with the segmentation result of the region growth algorithm. Finally, the images of 85 patients were used to train and test the algorithm model. Here, 46 patients were l applications.The presence of above-chance unconscious behavioral responses following stimulus presentation to the blind hemifield of hemianopic patients (blindsight) is a well-known phenomenon. What is still lacking is a systematic study of the neuroanatomical bases of two distinct aspects of blindsight the unconscious above chance performance and the phenomenological aspects that may be associated. Here, we tested 17 hemianopic patients in two tasks i.e. movement and orientation discrimination of a visual grating presented to the sighted or blind hemifield. We classified patients in four groups on the basis of the presence of above chance unconscious discrimination without or with perceptual awareness reports for stimulus presentation to the blind hemifield. A fifth group was represented by patients with interruption of the Optic Radiation. In the various groups we carried out analyses of lesion extent of various cortical areas, probabilistic tractography as well as assessment of the cortical thickness of the intact hemibe a result of neuroplastic compensatory mechanisms.Hydrogen sulfide (H2S) plays an important role in the plant salt stress response. The main component of salt stress is neutral salt (NaCl); NaHCO3 and Na2CO3 play a key role in soil alkaline due to the influence of pH. Malus hupehensis Rehd. var. pingyiensis Jiang (Pingyi Tiancha, PYTC) is a salt-sensitive apple rootstock. Seedlings of PYTC pretreated with NaHS (an H2S donor) were exposed to an alkaline salt solution, and then the plant growth, root architecture, oxidative damage, Na+/K+ homeostasis and gene expression of MhSOS1 and MhSKOR were investigated. The results showed that NaHS pretreatment increased the endogenous H2S content in seedlings, significantly alleviated the alkaline salt stress-induced growth inhibition and oxidative damage by inducing antioxidant enzymes activities, and sustained the root activity and root architecture of PYTC in the alkaline salt solution. NaHS pretreatment significantly decreased the root Na+ content and increased K+ content to maintain the homeostasis of Na+/K+, and effect the expression of MhSOS1 and MhSKOR at the transcription level in the presence of the alkaline salt.


