298 research outputs found
Pressure Driven Membrane Technology for Food and Biotechnology Industry
The increase in energy costs and the demands for products with greater nutritional value and of processing procedures less toxic to the environment are attractive factors for transferring membrane processing to food industry and biotechnology applications.
Sugar production is one of the most energy-intensive applications in the food industry, therefore membrane separation processes find many applications, nevertheless some limitation exist for application of membrane processes in the sugar industry.
This study focused on Food applications of membrane processes. A critical summary of a wide experimental investigation is reported. In this work, separation performances of commercial polyamide NF membranes are investigated in a wide range of compositions in the feed side at temperatures from 30 to 50°C; aqueous solutions containing monosaccharides, disaccharides, and mixtures of them are studied, and the role of the electrolytes on their rejection is investigated.
All the results obtained, have been organized in three main sections: (i) Hydraulic permeability, (ii) experimental investigation as it is, and (iii) Intrinsic membrane performances. Differently from literature, where typically aqueous solutions containing monosaccharides and oligosaccharides are used at low concentrations, at room temperature and only experimental data as it is are reported, a key point of this study is the critical evaluation based on intrinsic membrane performances.
The data processing discussed allows to introduce a revised Donnan Steric Pore & Dielectric Exclusion model.
The revised model provides useful elements to understand which kind of interactions (complex formation or dehydration) can affect sugars rejections in presence of strong electrolytes, however dehydration effects caused by temperature and electrolyte are the most evident.
The revised model is able to predict with good confidence both the temperature effect on membrane performances and rejections in multicomponent mixtures, ranging from laboratory to process/industrial scale
The occurrence of the Pear Psyllid, Cacopsylla bidens (Ĺ ulc, 1907) (insecta: Hemiptera: Psyllidae), in Uruguay
The Pear Psyllid, Cacopsylla bidens (Ĺ ulc, 1907), is here reported from the Department of Canelones, the major region of pear production in Uruguay. Previous records of C. pyricola (Foerster, 1848) from Uruguay are misidentifications of C. bidens. Information is provided on the taxonomy and biology of this species
Ensemble deep learning for the prediction of proficiency at a virtual simulator for robot-assisted surgery
Background
Artificial intelligence (AI) has the potential to enhance patient safety in surgery, and all its aspects, including education and training, will derive considerable benefit from AI. In the present study, deep-learning models were used to predict the rates of proficiency acquisition in robot-assisted surgery (RAS), thereby providing surgical programs directors information on the levels of the innate ability of trainees to facilitate the implementation of flexible personalized training.
Methods
176 medical students, without prior experience with surgical simulators, were trained to reach proficiency in five tasks on a virtual simulator for RAS. Ensemble deep neural networks (DNN) models were developed and compared with other ensemble AI algorithms, i.e., random forests and gradient boosted regression trees (GBRT).
Results
DNN models achieved a higher accuracy than random forests and GBRT in predicting time to proficiency, 0.84 vs. 0.70 and 0.77, respectively (Peg board 2), 0.83 vs. 0.79 and 0.78 (Ring walk 2), 0.81 vs 0.81 and 0.80 (Match board 1), 0.79 vs. 0.75 and 0.71 (Ring and rail 2), and 0.87 vs. 0.86 and 0.84 (Thread the rings 2). Ensemble DNN models outperformed random forests and GBRT in predicting number of attempts to proficiency, with an accuracy of 0.87 vs. 0.86 and 0.83, respectively (Peg board 2), 0.89 vs. 0.88 and 0.89 (Ring walk 2), 0.91 vs. 0.89 and 0.89 (Match board 1), 0.89 vs. 0.87 and 0.83 (Ring and rail 2), and 0.96 vs. 0.94 and 0.94 (Thread the rings 2).
Conclusions
Ensemble DNN models can identify at an early stage the acquisition rates of surgical technical proficiency of trainees and identify those struggling to reach the required expected proficiency level
Negative Feedback Regulation of Auxin Signaling by ATHB8/ACL5–BUD2 Transcription Module
ABSTRACT The role of auxin as main regulator of vascular differentiation is well established, and a direct correlation between the rate of xylem differentiation and the amount of auxin reaching the (pro)cambial cells has been proposed. It has been suggested that thermospermine produced by ACAULIS5 (ACL5) and BUSHY AND DWARF2 (BUD2) is one of the factors downstream to auxin contributing to the regulation of this process in Arabidopsis . Here, we provide an in-depth characterization of the mechanism through which ACL5 modulates xylem differentiation. We show that an increased level of ACL5 slows down xylem differentiation by negatively affecting the expression of homeodomain-leucine zipper ( HD–ZIP ) III and key auxin signaling genes. This mechanism involves the positive regulation of thermospermine biosynthesis by the HD–ZIP III protein ARABIDOPSIS THALIANA HOMEOBOX8 tightly controlling the expression of ACL5 and BUD2 . In addition, we show that the HD–ZIP III protein REVOLUTA contributes to the increased leaf vascularization and long hypocotyl phenotype of acl5 likely by a direct regulation of auxin signaling genes such as LIKE AUXIN RESISTANT2 ( LAX2 ) and LAX3 . We propose that proper formation and differentiation of xylem depend on a balance between positive and negative feedback loops operating through HD–ZIP III genes
Mechanical phenotyping of K562 cells by the Micropipette Aspiration Technique allows identifying mechanical changes induced by drugs
Mechanical properties of living cells can be used as reliable markers of their state, such as the presence of a pathological state or their differentiation phase. The mechanical behavior of cells depends on the organization of their cytoskeletal network and the main contribution typically comes from the actomyosin contractile system, in both suspended and adherent cells. In the present study, we investigated the effect of a pharmaceutical formulation (OTC - Ossitetraciclina liquida 20%) used as antibiotic, on the mechanical properties of K562 cells by using the Micropipette Aspiration Technique (MAT). This formulation has been shown to increase in a time dependent way the inflammation and toxicity in terms of apoptosis in in vitro experiments on K562 and other types of cells. Here we show that by measuring the mechanical properties of cells exposed to OTC for different incubation times, it is possible to infer modifications induced by the formulation to the actomyosin contractile system. We emphasize that this system is involved in the first stages of the apoptotic process where an increase of the cortical tension leads to the formation of blebs. We discuss the possible relation between the observed mechanical behavior of cells aspirated inside a micropipette and apoptosis
Infections in lung cancer patients undergoing immunotherapy and targeted therapy: an overview on the current scenario
Patients with a diagnosis of lung cancer are often vulnerable to infection, and the risk is increased by tumor-associated immunosuppression and the effects of the treatments. Historically, links between the risk of infection and cytotoxic chemotherapy due to neutropenia and respiratory syndromes are well established. The advent of tyrosine kinase inhibitors (TKIs) and immune-checkpoint inhibitors (ICIs) targeting the programmed cell death-1 (PD-1)/programmed cell death- ligand 1 (PD-L1) axis and cytotoxic T-lymphocyte antigen-4 (CTLA-4) have changed the treatment paradigm for lung cancer patients. Our understanding of the risk of infections while administrating these drugs is evolving, as are the biological mechanisms that are responsible. In this overview, we focus on the risk of infection with the use of targeted therapies and ICIs, summarizing current evidence from preclinical and clinical studies and discussing their clinical implications
Structured cost analysis of robotic TME resection for rectal cancer:a comparison between the da Vinci Si and Xi in a single surgeon's experience
Background: Robotic-assisted surgery by the da Vinci Si appears to benefit rectal cancer surgery in selected patients, but still has some limitations, one of which is its high costs. Preliminary studies have indicated that the use of the new da Vinci Xi provides some added advantages, but their impact on cost is unknown. The aim of the present study is to compare surgical outcomes and costs of rectal cancer resection by the two platforms, in a single surgeon’s experience. Methods: From April 2010 to April 2017, 90 robotic rectal resections were performed, with either the da Vinci Si (Si-RobTME) or the da Vinci Xi (Xi-RobTME). Based on CUSUM analysis, two comparable groups of 40 consecutive Si-RobTME and 40 consecutive Xi-RobTME were obtained from the prospectively collected database and used for the present retrospective comparative study. Data costs were analysed based on the level of experience on the proficiency–gain curve (p–g curve) by the surgeon with each platform. Results: In both groups, two homogeneous phases of the p–g curve were identified: Si1 and Xi1: cases 1–19, Si2 and Xi2: cases 20–40. A significantly higher number of full RAS operations were achieved in the Xi-RobTME group (p < 0.001). A statistically significant reduction in operating time (OT) during Si2 and Xi2 phase was observed (p < 0.001), accompanied by reduced overall variable costs (OVC), personnel costs (PC) and consumable costs (CC) (p < 0.001). All costs were lower in the Xi2 phase compared to Si2 phase: OT 265 versus 290 min (p = 0.052); OVC 7983 versus 10231.9 (p = 0.009); PC 1151.6 versus 1260.2 (p = 0.052), CC 3464.4 versus 3869.7 (p < 0.001). Conclusions: Our experience confirms a significant reduction of costs with increasing surgeon’s experience with both platforms. However, the economic gain was higher with the Xi with shorter OT, reduced PC and CC, in addition to a significantly larger number of cases performed by the fully robotic approach
Synthesis, structural studies and biological properties of new TBA analogues containing an acyclic nucleotide
A new modified acyclic nucleoside, namely N(1)-(3-hydroxy-2-hydroxymethyl-2-methylpropyl)-thymidine, was synthesized and transformed into a building block useful for oligonucleotide (ON) automated synthesis. A series of modified thrombin binding aptamers (TBAs) in which the new acyclic nucleoside replaces, one at the time, the thymidine residues were then synthesized and characterized by UV, CD, MS, and (1)H NMR. The biological activity of the resulting TBAs was tested by Prothrombin Time assay (PT assay) and by purified fibrinogen clotting assay. From a structural point of view, nearly all the new TBA analogues show a similar behavior as the unmodified counterpart, being able to fold into a bimolecular or monomolecular quadruplex structure depending on the nature of monovalent cations (sodium or potassium) coordinated in the quadruplex core. From the comparison of structural and biological data, some important structure-activity relationships emerged, particularly when the modification involved the TT loops. In agreement with previous studies we found that the folding ability of TBA analogues is more affected by modifications involving positions 4 and 13, rather than positions 3 and 12. On the other hand, the highest anti-thrombin activities were detected for aptamers containing the modification at T13 or T12 positions, thus indicating that the effects produced by the introduction of the acyclic nucleoside on the biological activity are not tightly connected with structure stabilities. It is noteworthy that the modification at T7 produces an ON being more stable and active than the natural TBA
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