119 research outputs found
Syngas quality in fluidized bed gasification of biomass: comparison between olivine and K-feldspar as bed materials
The relevance of selecting an appropriate bed material in fluidized bed gasification is a crucial aspect that is often underestimated. The ideal material should be economical, resistant to high temperatures and have small chemical interaction with biomass. However, often only the first of such three aspects is considered, neglecting the biomass–bed interaction effects that develop at high temperatures. In this work, olivine and K-feldspar were upscale-tested in a prototype fluidized bed gasifier (FBG) using arboreal biomass (almond shells). The produced syngas in the two different tests was characterized and compared in terms of composition (H2, CH4, CO, CO2, O2) and fate of contaminants such as volatile organic compounds (VOCs), tar and metals.. Moreover, the composition of olivine and K-feldspar before and after the biomass gasification process has been characterized. The aim of this work is to show which advantages and disadvantages there are in choosing the most suitable material and to optimize the biomass gasification process by reducing the undesirable effects, such as heavy metal production, bed agglomeration and tar production, which are harmful when syngas is used in internal combustion engines (ICE). It has been observed that metals, such as Ni, Cu, Zn, Cd, Sn, Ba and Pb, have higher concentrations in the syngas produced by using olivine as bed material rather than K-feldspar. In particular, heavy metals, such as Pb, Cu, Cd, Ni and Zn, show concentrations of 61.06 mg/Nm3, 15.29 mg/Nm3, 17.97 mg/Nm3, 37.29 mg/Nm3 and 116.39 mg/Nm3, respectively, compared to 23.26 mg/Nm3, 11.82 mg/Nm3, 2.76 mg/Nm3, 24.46 mg/Nm3 and 53.07 mg/Nm3 detected with K-feldspar. Moreover, a more hydrogen-rich syngas when using K-feldspar was produced (46% compared to 39% with olivine)
Increased Sensitivity of Computed Tomography Scan for Neoplastic Tissues Using the Extracellular Vesicle Formulation of the Contrast Agent Iohexol.
Computed tomography (CT) is a diagnostic medical imaging modality commonly used to detect disease and injury. Contrast agents containing iodine, such as iohexol, are frequently used in CT examinations to more clearly differentiate anatomic structures and to detect and characterize abnormalities, including tumors. However, these contrast agents do not have a specific tropism for cancer cells, so the ability to detect tumors is severely limited by the degree of vascularization of the tumor itself. Identifying delivery systems allowing enrichment of contrast agents at the tumor site would increase the sensitivity of detection of tumors and metastases, potentially in organs that are normally inaccessible to contrast agents, such as the CNS. Recent work from our laboratory has identified cancer patient-derived extracellular vesicles (PDEVs) as effective delivery vehicles for targeting diagnostic drugs to patients' tumors. Based on this premise, we explored the possibility of introducing iohexol into PDEVs for targeted delivery to neoplastic tissue. Here, we provide preclinical proof-of-principle for the tumor-targeting ability of iohexol-loaded PDEVs, which resulted in an impressive accumulation of the contrast agent selectively into the neoplastic tissue, significantly improving the ability of the contrast agent to delineate tumor boundaries
Pediatric cochlear implantation: an update
Deafness in pediatric age can adversely impact language acquisition as well as educational and social-emotional
development. Once diagnosed, hearing loss should be rehabilitated early; the goal is to provide the child with
maximum access to the acoustic features of speech within a listening range that is safe and comfortable. In presence
of severe to profound deafness, benefit from auditory amplification cannot be enough to allow a proper language
development. Cochlear implants are partially implantable electronic devices designed to provide profoundly deafened
patients with hearing sensitivity within the speech range. Since their introduction more than 30 years ago, cochlear
implants have improved their performance to the extent that are now considered to be standard of care in the
treatment of children with severe to profound deafness. Over the years patient candidacy has been expanded and
the criteria for implantation continue to evolve within the paediatric population. The minimum age for implantation
has progressively reduced; it has been recognized that implantation at a very early age (12–18 months) provides
children with the best outcomes, taking advantage of sensitive periods of auditory development. Bilateral implantation
offers a better sound localization, as well as a superior ability to understand speech in noisy environments than unilateral
cochlear implant. Deafened children with special clinical situations, including inner ear malformation, cochlear nerve
deficiency, cochlear ossification, and additional disabilities can be successfully treated, even thogh they require
an individualized candidacy evaluation and a complex post-implantation rehabilitation. Benefits from cochlear
implantation include not only better abilities to hear and to develop speech and language skills, but also improved
academic attainment, improved quality of life, and better employment status. Cochlear implants permit deaf people
to hear, but they have a long way to go before their performance being comparable to that of the intact human ear;
researchers are looking for more sophisticated speech processing strategies as well as a more efficient coupling
between the electrodes and the cochlear nerve with the goal of dramatically improving the quality of sound of
the next generation of implants
Elevated endocannabinoid plasma levels are associated with coronary circulatory dysfunction in obesity
Aims Aim of this study was to evaluate a possible association between endocannabinoid (EC) plasma levels, such as anandamide (AEA) and 2-arachidonoylglycerol (2-AG), and coronary circulatory function in obesity. Methods and results Myocardial blood flow (MBF) responses to cold pressor test (CPT) and during pharmacological vasodilation with dipyridamole were measured with 13N-ammonia PET/CT. Study participants (n = 77) were divided into three groups based on their body mass index (BMI, kg/m2): control group 20≤ BMI <25 (n = 21); overweight group, 25≤ BMI <30 (n = 26); and obese group, BMI ≥30 (n = 30). Anandamide plasma levels, but not 2-AG plasma levels, were significantly elevated in obesity as compared with controls, respectively [0.68 (0.53, 0.78) vs. 0.56 (0.47, 0.66) ng/mL, P = 0.020, and 2.2 (1.21, 4.59) vs. 2.0 (0.80, 5.90) ng/mL, P = 0.806)]. The endothelium-related change in MBF during CPT from rest (ΔMBF) progressively declined in overweight and obese when compared with control group [0.21 (0.10, 0.27) and 0.09 (−0.01, 0.15) vs. 0.26 (0.23, 0.39) mL/g/min; P = 0.010 and P = 0.0001, respectively). Compared with controls, hyperaemic MBFs were significantly lower in overweight and obese individuals [2.39 (1.97, 2.62) vs. 1.98 (1.69, 2.26) and 2.10 (1.76, 2.36); P = 0.007 and P = 0.042, respectively)]. In obese individuals, AEA and 2-AG plasma levels were inversely correlated with ΔMBF to CPT (r = −0.37, P = 0.046 and r = −0.48, P = 0.008) and hyperaemic MBFs (r = −0.38, P = 0.052 and r = −0.45, P = 0.017), respectively. Conclusions Increased EC plasma levels of AEA and 2-AG are associated with coronary circulatory dysfunction in obese individuals. This observation might suggest increases in EC plasma levels as a novel endogenous cardiovascular risk factor in obesity, but needing further investigation
Novel Insights into Autophagy and Prostate Cancer: A Comprehensive Review
Autophagy is a complex process involved in several cell activities, including tissue growth,
differentiation, metabolic modulation, and cancer development. In prostate cancer, autophagy has a
pivotal role in the regulation of apoptosis and disease progression. Several molecular pathways are
involved, including PI3K/AKT/mTOR. However, depending on the cellular context, autophagy may
play either a detrimental or a protective role in prostate cancer. For this purpose, current evidence has
investigated how autophagy interacts within these complex interactions. In this article, we discuss
novel findings about autophagic machinery in order to better understand the therapeutic response
and the chemotherapy resistance of prostate cancer. Autophagic-modulation drugs have been
employed in clinical trials to regulate autophagy, aiming to improve the response to chemotherapy or
to anti-cancer treatments. Furthermore, the genetic signature of autophagy has been found to have a
potential means to stratify prostate cancer aggressiveness. Unfortunately, stronger evidence is needed
to better understand this field, and the application of these findings in clinical practice still remains
poorly feasible
Accuracy of Immunodiagnostic Tests for Active Tuberculosis Using Single and Combined Results: A Multicenter TBNET-Study
The clinical application of IFN-gamma release assays (IGRAs) has recently improved the diagnosis of latent tuberculosis infection. In a multicenter study of the Tuberculosis Network European Trialsgroup (TBNET) we aimed to ascertain in routine clinical practice the accuracy of a novel assay using selected peptides encoded in the mycobacterial genomic region of difference (RD) 1 for the diagnosis of active tuberculosis in comparison with tuberculin skin test (TST), QuantiFERON-TB GOLD In-Tube (Cellestis Ltd., Carnegie, Australia) and T-SPOT.TB (Oxfordimmunotec, Abingdon, UK)
Perinatal Asphyxia Affects Rat Auditory Processing: Implications for Auditory Perceptual Impairments in Neurodevelopmental Disorders
Perinatal asphyxia, a naturally and commonly occurring risk factor in birthing, represents one of the major causes of neonatal encephalopathy with long term consequences for infants. Here, degraded spectral and temporal responses to sounds were recorded from neurons in the primary auditory cortex (A1) of adult rats exposed to asphyxia at birth. Response onset latencies and durations were increased. Response amplitudes were reduced. Tuning curves were broader. Degraded successive-stimulus masking inhibitory mechanisms were associated with a reduced capability of neurons to follow higher-rate repetitive stimuli. The architecture of peripheral inner ear sensory epithelium was preserved, suggesting that recorded abnormalities can be of central origin. Some implications of these findings for the genesis of language perception deficits or for impaired language expression recorded in developmental disorders, such as autism spectrum disorders, contributed to by perinatal asphyxia, are discussed
A machine-learning based bio-psycho-social model for the prediction of non-obstructive and obstructive coronary artery disease
Background: Mechanisms of myocardial ischemia in obstructive and non-obstructive coronary artery disease (CAD), and the interplay between clinical, functional, biological and psycho-social features, are still far to be fully elucidated. Objectives: To develop a machine-learning (ML) model for the supervised prediction of obstructive versus non-obstructive CAD. Methods: From the EVA study, we analysed adults hospitalized for IHD undergoing conventional coronary angiography (CCA). Non-obstructive CAD was defined by a stenosis < 50% in one or more vessels. Baseline clinical and psycho-socio-cultural characteristics were used for computing a Rockwood and Mitnitski frailty index, and a gender score according to GENESIS-PRAXY methodology. Serum concentration of inflammatory cytokines was measured with a multiplex flow cytometry assay. Through an XGBoost classifier combined with an explainable artificial intelligence tool (SHAP), we identified the most influential features in discriminating obstructive versus non-obstructive CAD. Results: Among the overall EVA cohort (n = 509), 311 individuals (mean age 67 ± 11 years, 38% females; 67% obstructive CAD) with complete data were analysed. The ML-based model (83% accuracy and 87% precision) showed that while obstructive CAD was associated with higher frailty index, older age and a cytokine signature characterized by IL-1β, IL-12p70 and IL-33, non-obstructive CAD was associated with a higher gender score (i.e., social characteristics traditionally ascribed to women) and with a cytokine signature characterized by IL-18, IL-8, IL-23. Conclusions: Integrating clinical, biological, and psycho-social features, we have optimized a sex- and gender-unbiased model that discriminates obstructive and non-obstructive CAD. Further mechanistic studies will shed light on the biological plausibility of these associations. Clinical trial registration: NCT02737982
SARS-CoV-2 susceptibility and COVID-19 disease severity are associated with genetic variants affecting gene expression in a variety of tissues
Variability in SARS-CoV-2 susceptibility and COVID-19 disease severity between individuals is partly due to
genetic factors. Here, we identify 4 genomic loci with suggestive associations for SARS-CoV-2 susceptibility
and 19 for COVID-19 disease severity. Four of these 23 loci likely have an ethnicity-specific component.
Genome-wide association study (GWAS) signals in 11 loci colocalize with expression quantitative trait loci
(eQTLs) associated with the expression of 20 genes in 62 tissues/cell types (range: 1:43 tissues/gene),
including lung, brain, heart, muscle, and skin as well as the digestive system and immune system. We perform
genetic fine mapping to compute 99% credible SNP sets, which identify 10 GWAS loci that have eight or fewer
SNPs in the credible set, including three loci with one single likely causal SNP. Our study suggests that the
diverse symptoms and disease severity of COVID-19 observed between individuals is associated with variants across the genome, affecting gene expression levels in a wide variety of tissue types
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