1,009 research outputs found
Polyhydroxyalkanoates production in aerobic sequential processes by mixed microbial cultures
The current emphasis on sustainability, eco-efficiency and green chemistry has led to intensive search for renewable and environmentally friendly resources. Thus, sustainable development is recognized to be essential for the growth of the economy and industrial productivity. Since global petroleum reserves are finite, there is a need for additional new sources of durable materials. Renewable materials from microorganisms can provide a source of sustainable alternative to petroleum derived chemicals including polymers. Polyhydroxyalkanoates (PHA) are one of the relatively newer families of biodegradable polymers that have great potential in the future due to their variability in properties, they are polyesters of hydroxyalkanoic acids that have received extensive attention due to their inherent biocompatibility and biodegradability. The most widely applied strategy for PHA production is to cultivate one wild-type or genetically recombinant bacterial strain with a renewable but refined substrate. At the same time, some of the bacteria naturally occurring in open mixed microbial cultures (activated sludge) treating wastewaters are able to store PHA. In the wastewater treatment plant, carbon storage in the form of PHA can be enhanced under dynamic conditions respect to microbial substrate. In this way, while the wastewater treatment is applied favoring the PHA storing bacteria, a biopolymer can be harvested as a value-added resource from wastewater treatment system. The research activities of the thesis has been divided in 3 fundamental steps:
a) under new dynamic feeding condition (feast-famine) in Sequencing Batch Reactor (SBR), the process performance was investigated in the early days after start up, performing the PHA-accumulation stage in batch, under pulse feeding condition. The new process concept was evaluated in terms of specific storage rate and yield, PHA biomass content and PHA productivity;
b) the more traditional steady-state approach has been applied at fixed operating parameters (OLR, HRT, pH, T) with the exception of the frequency of the alternation of the feast and famine phases. Microbial community analysis, based on denaturing gradient gel electrophoresis (DGGE) was carried out in order to evaluate if the cycle length plays a main role on the microbial speciation within the SBR;
c) based on the results obtained at the point (b), a continuous system (SBR and accumulation) was developed. The PHA-saturated biomass was daily collected and treated with quenching reagent for PHA extraction; then the stored polymer was purified and characterized via lyophilization and chloroform purification;
d) the last part of the experimental program consists in the optimization of the accumulation stage in terms of nutrient content of wastewaters used as substrate, in particular the nitrogen and phosphorous concentration; the COD/N and COD/P ratios covered a wide range of values, changing from starvation to excess condition in the growth medium.
The achieved results open new perspectives and solutions for further investments and technology applications, in particular its integration within public services like the traditional wastewater treatment plants and anaerobic digestion plants
Global constraints on absolute neutrino masses and their ordering
Within the standard three-neutrino framework, the absolute neutrino masses
and their ordering (either normal, NO, or inverted, IO) are currently unknown.
However, the combination of current data coming from oscillation experiments,
neutrinoless double beta decay searches, and cosmological surveys, can provide
interesting constraints for such unknowns in the sub-eV mass range, down to
O(0.1) eV in some cases. We discuss current limits on absolute neutrino mass
observables by performing a global data analysis, that includes the latest
results from oscillation experiments, neutrinoless double beta decay bounds
from the KamLAND-Zen experiment, and constraints from representative
combinations of Planck measurements and other cosmological data sets. In
general, NO appears to be somewhat favored with respect to IO at the level of
~2 sigma, mainly by neutrino oscillation data (especially atmospheric),
corroborated by cosmological data in some cases. Detailed constraints are
obtained via the chi^2 method, by expanding the parameter space either around
separate minima in NO and IO, or around the absolute minimum in any ordering.
Implications for upcoming oscillation and non-oscillation neutrino experiments,
including beta-decay searches, are also discussed.Comment: 17 pages, including 3 tables and 11 figure
RFID technology for blood tracking: An experimental approach for benchmarking different devices
OBJECTIVE: The objective of the paper is to design a testing protocol to measure performances of RFID devices applied to blood supply chain, and to implement an experimental campaign in order to collect performance data. The protocol matches operational conditions in blood supply chain and is particularly tailored to some critical processes, which can benefit from RFID adoption. The paper thus strives at benchmarking performances of inlays, fixed and handheld RFID readers, when deployed in the blood supply chain processes. DESIGN, METHODOLOGY, APPROACH: The adopted testing protocol enables the assessment of performances of RFID devices in processes of the blood supply chain, since it has been developed peculiarly to emulate critical logistics processes. The testing protocol has been designed jointly with hospital personnel involved in every day operations on blood bags and tubes in order to improve processes, in terms of safety and reliability. The testing protocol has been applied to 3 inlays, 2 fixed readers, 1 mobile handheld in 3 logistics processes, all operating according to UHF EPC class 1 gen 2 protocols and ETSI regulations. We measured and compared read rates, accuracies and read times. FINDINGS: The results of the test give a direct insight of performances to be expected from different RFID devices when deployed in a real-world environment. Therefore, it is possible to give answers to how a specific piece of hardware - such as an inlay or a reader - performs, and how it can be effectively used to improve security of patients in healthcare. At the same time, researchers focusing on the business process reengineering of blood supply chain can assess the technical feasibility of the RFID-reengineered logistics processes in order to improve the safety of end users
Functional Annotation of Genes Overlapping Copy Number Variants in Autistic Patients: Focus on Axon Pathfinding
We have used Gene Ontology (GO) and pathway analyses to uncover the common functions associated to the genes overlapping Copy Number Variants (CNVs) in autistic patients. Our source of data were four published studies [1-4]. We first applied a two-step enrichment strategy for autism-specific genes. We fished out from the four mentioned studies a list of 2928 genes overall overlapping 328 CNVs in patients and we first selected a sub-group of 2044 genes after excluding those ones that are also involved in CNVs reported in the Database of Genomic Variants (enrichment step 1). We then selected from the step 1-enriched list a sub-group of 514 genes each of which was found to be deleted or duplicated in at least two patients (enrichment step 2). The number of statistically significant processes and pathways identified by the Database for Annotation, Visualization and Integrated Discovery and Ingenuity Pathways Analysis softwares with the step 2-enriched list was significantly higher compared to the step 1-enriched list. In addition, statistically significant GO terms, biofunctions and pathways related to nervous system development and function were exclusively identified by the step 2-enriched list of genes. Interestingly, 21 genes were associated to axon growth and pathfinding. The latter genes and other ones associated to nervous system in this study represent a new set of autism candidate genes deserving further investigation. In summary, our results suggest that the autism’s “connectivity genes” in some patients affect very early phases of neurodevelopment, i.e., earlier than synaptogenesis
Covid-2019 pandemic: growing wave of cancelled meetings in oral and maxillofacial surgery and its impact on specialty
We are at war. All our energy should be on one aim: to slow the progress of the virus. 1
—Emmanuel Macron
French President (March 16, 2020)
The official cause of the coronavirus disease 2019 (Covid-19) 2 became a novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) 3 which was officially identified on January 9, 2020. 4
Generally described four transmission routes for the Covid-19: 1) aerosol transmission, 2) contact transmission, 3) droplets transmission, and even through 4) digestive system. 3 The most commonly reported symptoms in patients are cough, fever, myalgia/fatigue, pneumonia, and complicated dyspnea. 3,5 According to Li et al cases resulting in death were primarily in elderly and middle-aged patients with pre-existing co-morbidities. 6 The statistically proved number of death worldwide continues permanently to increase. On March 26 that number of death reached 21,297 people, 7 on April 1 – 42,341 people, 8 on April 7 – 74,820 people, 9 on May 29 – 362,091 10 , and on August 11 – 739,342 1
Presence of oxytocin, vasopressin and atrial natriuretic peptide and their modification in rat hypothalamic paraventricular nucleus during resistance training.
Many studies have demonstrated the physiological effects of oxytocin (OT), atrial natriuretic peptide (ANP) and vasopressin (VP) in the homoeostasis of body fluids during physical exercise. However, a little information is available about the related immunohistochemical changes in hypothalamic magnocellular neurosecretory system during and after the training. The aim of the present work was to study the immunohistochemical changes in OT, ANP and VP levels in the hypothalamic paraventricular nucleus during and after resistance exercise protocol. Three groups of Wistar rats were trained by a rung ladder protocol for 15, 30 and 45 days, respectively; a fourth group was left to rest for 15 days after the training. Finally, four sedentary groups were used as controls. The results show that resistance training induces a significant reduction in the percentage of OT-positive neurons, compared with sedentary controls. In contrast, this protocol did not induce any change in VP levels, and ANP levels did not change significantly. However, VP increased after the resting period of 15 days. Our work shows that neurons of the paraventricular nucleus are involved in body fluid homoeostasis during and after resistance exercise. The functional significance of these changes in OT and VP levels, during and after the protocol, needs to be further investigated
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