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1.
Nature ; 597(7877): 485-488, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34552255

RESUMO

Star formation in half of massive galaxies was quenched by the time the Universe was 3 billion years old1. Very low amounts of molecular gas seem to be responsible for this, at least in some cases2-7, although morphological gas stabilization, shock heating or activity associated with accretion onto a central supermassive black hole are invoked in other cases8-11. Recent studies of quenching by gas depletion have been based on upper limits that are insufficiently sensitive to determine this robustly2-7, or stacked emission with its problems of averaging8,9. Here we report 1.3 mm observations of dust emission from 6 strongly lensed galaxies where star formation has been quenched, with magnifications of up to a factor of 30. Four of the six galaxies are undetected in dust emission, with an estimated upper limit on the dust mass of 0.0001 times the stellar mass, and by proxy (assuming a Milky Way molecular gas-to-dust ratio) 0.01 times the stellar mass in molecular gas. This is two orders of magnitude less molecular gas per unit stellar mass than seen in star forming galaxies at similar redshifts12-14. It remains difficult to extrapolate from these small samples, but these observations establish that gas depletion is responsible for a cessation of star formation in some fraction of high-redshift galaxies.

2.
Environ Res ; 246: 118046, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38160968

RESUMO

Tannery sludge, a challenging waste, was utilized as a substrate for the production of Short-Chain Fatty Acids (SCFAs) through a series of six thermophilic Continuous Stirred-Tank Reactor runs. The sludge was subjected to a mild thermal pre-treatment and incorporated zeolites (chabazite in run II, and clinoptilolite in run III) in the acidification process. Results highlighted zeolites' impact on chromium concentration and the SCFAs/CODSOL ratio. Ammonia release remained consistent at around 47 % and 51 % for run I and II, respectively, but surpassed 60% in run III, suggesting limited zeolite effectiveness in NH4 absorption. Chromium release in the liquid fraction, due to thermal pretreatment, reached 335 mg/L. While in tests without zeolite, complete removal proved challenging, in zeolite-amended runs, complete removal was achieved, showcasing the materials' heavy metal absorption capacity. SCFA concentrations reached 20260 mgCOD/L, with acidification efficiency varying; runs I and III had ratios around 0.70 COD/COD, while run II showed substantial improvement (0.92) with chabazite. Anaerobic fermentation-digestion mass balance indicated a 41% reduction in landfill sludge mass, reducing its environmental footprint while yielding valuable byproducts like biogas and SCFAs. These findings underscore zeolites' potential in heavy metal absorption and acidification process enhancement, paving the way for applications with tannery sludge.


Assuntos
Metais Pesados , Zeolitas , Esgotos , Anaerobiose , Ácidos Graxos Voláteis , Fermentação , Cromo , Concentração de Íons de Hidrogênio
3.
Molecules ; 26(3)2021 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-33494198

RESUMO

Polyhydroxyalkanoates (PHAs) are well-known biodegradable plastics produced by various bacterial strains, whose major drawback is constituted by the high cost of their synthesis. Producing PHAs from mixed microbial cultures and employing organic wastes as a carbon source allows us to both reduce cost and valorize available renewable resources, such as food waste and sewage sludge. However, different types of pollutants, originally contained in organic matrices, could persist into the final product, thus compromising their safety. In this work, the exploitation of municipal wastes for PHA production is evaluated from the environmental and health safety aspect by determining the presence of polycyclic aromatic hydrocarbons (PAHs) in both commercial and waste-based PHA samples. Quantification of PAHs by gas chromatography-mass spectrometry on 24 PHA samples obtained in different conditions showed very low contamination levels, in the range of ppb to a few ppm. Moreover, the contaminant content seems to be dependent on the type of PHA stabilization and extraction, but independent from the type of feedstock. Commercial PHA derived from crops, selected for comparison, showed PAH content comparable to that detected in PHAs derived from organic fraction of municipal solid waste. Although there is no specific regulation on PAH maximum levels in PHAs, detected concentrations were consistently lower than threshold limit values set by regulation and guidelines for similar materials and/or applications. This suggests that the use of organic waste as substrate for PHA production is safe for both the human health and the environment.


Assuntos
Bactérias/crescimento & desenvolvimento , Reatores Biológicos , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Poli-Hidroxialcanoatos/metabolismo , Esgotos/microbiologia , Eliminação de Resíduos Líquidos , Bactérias/classificação , Humanos
4.
Future Oncol ; 14(13s): 61-72, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29989453

RESUMO

New therapeutic options in non-small-cell lung cancer have been available through a great in-depth and genomic research, improving preclinical disease patterns and identifying the specific toxicity of target therapy. The multidisciplinary approach, increasingly practiced among clinicians, researchers, pharmaceutical companies and ethics committees has allowed the emergence of a new generation of translational clinical trials and the adoption of new technologies (e.g., point-of-care sequencing), then speeding up the development and trade of these new drugs. Consequently, there is a long list of therapeutic candidates that need to be efficiently evaluated early in the context of Phase I clinical trials. In this review, we discuss some of the key developments and novelties in the main histological groups.


Assuntos
Biomarcadores Tumorais , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/etiologia , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/etiologia , Terapia de Alvo Molecular , Animais , Carcinoma Pulmonar de Células não Pequenas/patologia , Ensaios Clínicos como Assunto , Humanos , Neoplasias Pulmonares/patologia , Estadiamento de Neoplasias , Pesquisa Translacional Biomédica
5.
Int J Urol ; 22(9): 861-6, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26010048

RESUMO

OBJECTIVES: To report our initial experience with urethra-sparing reconstruction combining dorsal preputial skin and ventral buccal mucosa grafts for tight bulbar urethral strictures. METHODS: Between November 2006 and September 2012, 26 patients with tight bulbar strictures underwent urethroplasty. Using a ventral urethrotomy approach, the two-sided urethral reconstruction was carried out avoiding the transection of urethra and augmenting the preserved urethral plate by dorsal preputial skin plus ventral buccal mucosa grafts. The primary outcome was the objective urinary result, defined as the absence of stricture recurrence. The outcome was considered a failure when any postoperative instrumentation was required. Postoperative sexual dysfunctions were investigated using a validated questionnaire. RESULTS: Mean follow up was 30.1 months (range 12-79 months). Mean stricture length was 3.3 cm (range 1.5-6 cm). Mean length for dorsal preputial skin and ventral buccal mucosa grafts was 3.2 cm (range 2-7 cm) and 4.9 cm (range 4-6 cm), respectively. Of 26 cases, 23 (88.5%) were successful and three (11.5%) were failures with stricture recurrence. Failures were treated with perineal urethrostomy in one case, ventral buccal graft urethroplasty in one case and internal urethrotomy in one case. Among 12 sexually active men preoperatively, none reported postoperative penile curvature/shortening, impaired erection or dissatisfaction regarding erection; sexual activity was unaltered pre- and post-surgery. CONCLUSIONS: In tight bulbar urethra strictures, the two-sided urethroplasty combining dorsal preputial skin and ventral buccal mucosa grafts provides a safe and effective semi-circumferential reconstruction by augmenting the preserved urethral plate, with no impact on sexual function.


Assuntos
Mucosa Bucal/transplante , Transplante de Pele , Estreitamento Uretral/cirurgia , Procedimentos Cirúrgicos Urológicos Masculinos/métodos , Adolescente , Adulto , Idoso , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Tratamentos com Preservação do Órgão , Pênis , Recidiva , Reoperação , Saúde Reprodutiva , Estudos Retrospectivos , Sexualidade , Inquéritos e Questionários , Falha de Tratamento , Estreitamento Uretral/patologia , Adulto Jovem
6.
Artigo em Inglês | MEDLINE | ID: mdl-38376782

RESUMO

Gas-permeable membrane (GPM) technology is gaining interest to recover nitrogen from residual effluents due to its effectiveness, simple operation and capacity of producing a nutrient rich product with fertilising value. In this study, a GPM contactor was used at 25 °C to recover total ammoniacal nitrogen (TAN) from swine slurry as a concentrated (NH4)2SO4 solution. Firstly, a synthetic solution was tested on a wide pH range (6-12). Results showed that the ammonia mass transfer constants (Km) increased from 7.9·10-9 to 1.2·10-6 m/s as the pH increased. The reagent consumption to control the pH per mole nitrogen recovered had a minimum at pH 9, which showed a Km value of 3.0·10-7 m/s. Secondly, various pH control strategies were tested using swine slurry, including (i) no pH control, (ii) pH control at 8.5, 9.0 and 10.0, and (iii) an initial spike of the NaOH equivalent to the required to control the pH at 9. The test without pH control reached a TAN recovery of around 60%, which could be an interesting strategy when high nitrogen recoveries or short operating times are not required. The pH control at 9 stood out as the most favourable operating condition due to its high Km and lower reagent consumption. Thirdly, several feed-to-trapping volume ratios ranging from 1:1 to 15:1 were tested using swine slurry at pH 9. These assays revealed that a GPM process with a high feed-to-trapping volume ratio fastens the recovery of 99% of TAN as a high purity (NH4)2SO4 solution containing 40 g N/L.

7.
Chemosphere ; 338: 139468, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37442385

RESUMO

The present study describes the microbial production of polyhydroxyalkanoates (PHA) from thermally pre-treated sewage sludge at pilot scale level, investigating for the first time the effect of the organic loading rate (OLR) under oxygen limitation on biomass storage properties and kinetics. Polymer characteristics have been also evaluated. The selection/enrichment of PHA-storing biomass was successfully achieved in a Sequencing Batch Reactor (SBR) under short hydraulic retention time (HRT; 2 days). Low OLR (2.05 g COD/L d) was ideal for the selection of an efficient PHA-producing consortium cultivated under limited oxygen availability. In the fed-batch accumulation conducted under high DO regime, such biomass was characterized by 51% of PHA content on cell dry weight, with a related storage yield (YP/Sbatch) of 0.61 CODPHA/CODS. On the contrary, medium OLR (4.56 g COD/L d) was not technically feasible to sustain the required consortium's selection under low DO regime. The PHA produced by biomass cultivated under low DO regime was characterized higher thermal stability and crystalline domain compared to PHA traditionally produced under high DO regime. The mass balance assessment highlighted a global yield of 51 g PHA/kg VS (volatile solids of thickened sludge), which was 9% lower than yield obtained under high DO regime, in the face of a realistic reduction of the energy cost of the process.


Assuntos
Poli-Hidroxialcanoatos , Esgotos , Fermentação , Reatores Biológicos , Oxigênio , Anaerobiose , Biomassa
8.
Bioengineering (Basel) ; 9(3)2022 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-35324814

RESUMO

Volatile fatty acid (VFA) rich streams from fermentation of organic residuals and wastewater are suitable feedstocks for mixed microbial culture (MMC) Polyhydroxyalkanoate (PHA) production. However, many such streams have low total VFA concentration (1-10 gCOD/L). PHA accumulation requires a flow-through bioprocess if the VFAs are not concentrated. A flow through bioprocess must balance goals of productivity (highest possible influent flow rates) with goals of substrate utilization efficiency (lowest possible effluent VFA concentration). Towards these goals, dynamics of upshift and downshift respiration kinetics for laboratory and pilot scale MMCs were evaluated. Monod kinetics described a hysteresis between the upshift and downshift responses. Substrate concentrations necessary to stimulate a given substrate uptake rate were significantly higher than the concentrations necessary to sustain the attained substrate uptake rate. A benefit of this hysteresis was explored in Monte Carlo based PHA accumulation bioprocess numerical simulations. Simulations illustrated for a potential to establish continuous flow-through PHA production bioprocesses even at a low (1 gCOD/L) influent total VFA concentration. Process biomass recirculation into an engineered higher substrate concentration mixing zone, due to the constant influent substrate flow, enabled to drive the process to maximal possible PHA production rates without sacrificing substrate utilization efficiency.

9.
Bioresour Technol ; 361: 127716, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35926558

RESUMO

Dairy products, extra virgin olive oil, red and white wines are excellent food products, appreciated all around the world. Their productions generate large amounts of by-products which urge for recycling and valorization. Moreover, another abundant waste stream produced in urban context is the Organic Fraction of Municipal Solid Wastes (OFMSW), whose global annual capita production is estimated at 85 kg. The recent environmental policies encourage their exploitation in a biorefinery loop to produce Volatile Fatty Acids (VFAs) and polyhydroxyalkanoates (PHAs). Typically, VFAs yields are high from cheese whey and OFMSW (0.55-0.90 gCOD_VFAs/gCOD), lower for Olive Mill and Winery Wastewaters. The VFAs conversion into PHAs can achieve values in the range 0.4-0.5 gPHA/gVSS for cheese whey and OFMSW, 0.6-0.7 gPHA/gVSS for winery wastewater, and 0.2-0.3 gPHA/gVSS for olive mill wastewaters. These conversion yields allowed to estimate a huge potential annual PHAs production of about 260 M tons.


Assuntos
Olea , Poli-Hidroxialcanoatos , Reatores Biológicos , Ácidos Graxos Voláteis , Resíduos Sólidos , Águas Residuárias
10.
Polymers (Basel) ; 13(16)2021 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-34451326

RESUMO

Volatile fatty acids obtained from the fermentation of the organic fraction of municipal solid waste can be used as raw materials for non-toxic ethyl ester (EE) synthesis as well as feedstock for the production of polyhydroxyalkanoates (PHAs). Taking advantage of the concept of an integrated process of a bio-refinery, in the present paper, a systematic investigation on the extraction of intracellular poly(3-hydroxybutyrate-co-3-hydroxyvalerate), produced by mixed microbial culture by using EEs was reported. Among the tested EEs, ethyl acetate (EA) was the best solvent, dissolving the copolymer at the lowest temperature. Then, extraction experiments were carried out by EA at different temperatures on two biomass samples containing PHAs with different average molecular weights. The parallel characterization of the extracted and non-extracted PHAs evidenced that at the lower temperature (100 °C) EA solubilizes preferentially the polymer fractions richer in 3HV comonomers and with the lower molecular weight. By increasing the extraction temperature from 100 °C to 125 °C, an increase of recovery from about 50 to 80 wt% and a molecular weight reduction from 48% to 65% was observed. The results highlighted that the extracted polymer purity is always above 90 wt% and that it is possible to choose the proper extraction condition to maximize the recovery yield at the expense of polymer fractionation and degradation at high temperatures or use milder conditions to maintain the original properties of a polymer.

11.
Front Bioeng Biotechnol ; 9: 628719, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33681164

RESUMO

Polyhydroxyalkanoates (PHAs) production at pilot scale has been recently investigated and carried out exploiting different process configurations and organic wastes. More in detail, three pilot platforms, in Treviso (North-East of Italy), Carbonera (North-East of Italy) and Lisbon, produced PHAs by open mixed microbial cultures (MMCs) and different organic waste streams: organic fraction of municipal solid waste and sewage sludge (OFMSW-WAS), cellulosic primary sludge (CPS), and fruit waste (FW), respectively. In this context, two stabilization methods have been applied, and compared, for preserving the amount of PHA inside the cells: thermal drying and wet acidification of the biomass at the end of PHA accumulation process. Afterward, polymer has been extracted following an optimized method based on aqueous-phase inorganic reagents. Several PHA samples were then characterized to determine PHA purity, chemical composition, molecular weight, and thermal properties. The polymer contained two types of monomers, namely 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (3HV) at a relative percentage of 92.6-79.8 and 7.4-20.2 w/w, respectively, for Treviso and Lisbon plants. On the other hand, an opposite range was found for 3HB and 3HV monomers of PHA from Carbonera, which is 44.0-13.0 and 56.0-87.0 w/w, respectively. PHA extracted from wet-acidified biomass had generally higher viscosity average molecular weights (M v ) (on average 424.8 ± 20.6 and 224.9 ± 21.9 KDa, respectively, for Treviso and Lisbon) while PHA recovered from thermally stabilized dried biomass had a three-fold lower M v .

12.
Arch Biochem Biophys ; 500(2): 116-22, 2010 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-20494652

RESUMO

Chemoresistance is a multifactorial phenomenon and many studies clearly show that a coordinated expression of efflux transporter proteins and phase II conjugating enzymes in tumor cells is linked to the development of the multidrug resistance phenotype. In particular, the overexpression of glutathione S-transferases and efflux pumps in tumors may reduce the reactivity of various anticancer drugs. In recent years it has become evident that glutathione S-transferases are also involved in the control of apoptosis through the inhibition of the JNK signaling pathway. As such, the glutathione S-transferase superfamily has become the focus of extensive pharmaceutical research in attempt to generate more efficient anticancer agents. Here we present an overview of the GST inhibitors and the GST-activated pro-drugs utilized to date to overcome drug resistance.


Assuntos
Resistencia a Medicamentos Antineoplásicos/fisiologia , Glutationa Transferase/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/enzimologia , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Transportadores de Cassetes de Ligação de ATP/metabolismo , Animais , Antineoplásicos/química , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Transporte Biológico Ativo , Resistência a Múltiplos Medicamentos/fisiologia , Inibidores Enzimáticos/farmacologia , Glutationa Transferase/antagonistas & inibidores , Humanos , Neoplasias/patologia , Pró-Fármacos/química , Pró-Fármacos/farmacocinética , Pró-Fármacos/farmacologia
13.
J Biotechnol ; 323: 54-61, 2020 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-32763260

RESUMO

The utilisation of urban organic waste as feedstock for polyhydroxyalkanoates (PHA) production is growing since it allows to solve the main concerns about their disposal and simultaneously to recover added-value products. A pilot scale platform has been designed for this purpose. The VFA-rich fermentation liquid coming from the anaerobic treatment of both source-sorted organic fraction of municipal solid waste (OFMSW) and waste activated sludge (WAS) has been used as substrate for the aerobic process steps: a first sequencing batch reactor (SBR, 100 L) for the selection of a PHA-producing biomass, and a second fed-batch reactor (70 L) for PHA accumulation inside the cells. The SBR was operated at 2.0-4.4 kg COD/(m3 d) as OLR, under dynamic feeding regime (feast-famine) and short hydraulic retention time (HRT; 1 day). The selected biomass was able to accumulate up to 48% g PHA/g VSS. Both steps were performed without temperature (T) control, avoiding additional consumption of energy. In this regard, the applied OLR was tuned based on environmental T and, as a consequence, on biomass kinetic, in order to have a constant selective pressure. The latter was mainly quantified by the PHA storage yield (YP/Sfeast 0.34-0.45 CODP/CODS), which has been recognized as the main parameters affecting the global PHA productivity [1.02-1.82 g PHA/(L d)] of the process.


Assuntos
Meios de Cultura/química , Alimentos , Poli-Hidroxialcanoatos/metabolismo , Esgotos/microbiologia , Temperatura , Técnicas de Cultura Celular por Lotes , Biomassa , Reatores Biológicos , Fermentação , Eliminação de Resíduos
14.
N Biotechnol ; 56: 140-148, 2020 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-32017996

RESUMO

The selection and enrichment of a mixed microbial culture (MMC) for polyhydroxyalkanoates (PHA) production is a well-known technology, typically carried out in sequencing batch reactors (SBR) operated under a feast-famine regime. With a nitrogen-deficient carbon source to be used as feedstock for PHA synthesis, a nutrient supply in the SBR is required for efficient microbial growth. In this study, an uncoupled carbon (C) and nitrogen (N) feeding strategy was adopted by dosing the C-source at the beginning of the feast and the N-source at the beginning of the famine, at a fixed C/N ratio of 33.4 g COD/g N and 12 h cycle length. The applied organic loading rate (OLR) was increased from 4.25 to 8.5 and finally to 12.725 g COD/L d. A more efficient selective pressure was maintained at lower and intermediate OLR, where the feast phase length was shorter (around 20 % of the whole cycle length). However, at the higher OLR investigated, the PHA content in the biomass reached a value of 0.53 g PHA/g VSS at the end of the feast phase, as a consequence of the increased C-source loaded per cycle. Moreover, 2nd stage PHA productivity was 2.4 g PHA/L d, 1.5 and 3.0-fold higher than those obtained at lower OLR. The results highlight the possibility of simplifying the process by withdrawing the biomass at the end of the feast phase directly to downstream processing, without a need for the intermediate accumulation step.


Assuntos
Reatores Biológicos , Carbono/metabolismo , Consórcios Microbianos , Nitrogênio/metabolismo , Poli-Hidroxialcanoatos/biossíntese , Biomassa , Carbono/química , Nitrogênio/química
15.
Water Res ; 170: 115371, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31835138

RESUMO

This study focuses on the application of the concept of circular economy, with the creation of added-value marketable products and energy from organic waste while minimizing environmental impacts. Within this purpose, an urban biorefinery technology chain has been developed at pilot scale in the territorial context of the Treviso municipality (northeast Italy) for the production of biopolymers (polyhydroxyalkanoates, PHAs) and biogas from waste of urban origin. The piloting system (100-380 L) comprised the following units: a) acidogenic fermentation of the organic fraction of municipal solid waste (OFMSW) and biological sludge; b) two solid/liquid separation steps consisting of a coaxial centrifuge and a tubular membrane (0.2 µm porosity); c) a Sequencing Batch Reactor (SBR) for aerobic PHA-storing biomass production; d) aerobic fed-batch PHA accumulation reactor and e) Anaerobic co-digestion (ACoD). The thermal pre-treatment (72 °C, 48 h) of the feedstock enhanced the solubilization of the organic matter, which was converted into volatile fatty acids (VFAs) in batch mode under mesophilic fermentation conditions (37 °C). The VFA content increased up to 30 ± 3 g COD/L (overall yield 0.65 ± 0.04 g CODVFA/g VS(0)), with high CODVFA/CODSOL (0.86 ± 0.05). The high CODVFA/CODSOL ratio enhanced the PHA-storing biomass selection in the SBR by limiting the growth of the non-storing microbial population. Under fully aerobic feast-famine regime, the selection reactor was continuously operated for 6 months at an average organic loading rate (OLR) of 4.4 ± 0.6 g COD/L d and hydraulic retention time (HRT) of 1 day (equal to SRT). The ACoD process (HRT 15 days, OLR 3.0-3.5 kg VS/m3 d) allowed to recover the residual solid-rich overflows generated by the two solid/liquid separation units with the production of biogas (SGP 0.44-0.51 m3/kg VS) and digestate. An overall yield of 7.6% wt PHA/VS(0) has been estimated from the mass balance. In addition, a preliminary insight into potential social acceptance and barriers regarding organic waste-derived products was obtained.


Assuntos
Poli-Hidroxialcanoatos , Eliminação de Resíduos , Biocombustíveis , Reatores Biológicos , Alimentos , Itália , Esgotos
16.
ACS Appl Bio Mater ; 3(9): 6110-6123, 2020 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-35021744

RESUMO

The present study reports on the production and characterization of a new biopackaging material made of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) derived from municipal biowaste (MBW) and produced by the mixed bacterial culture technology. After purification and extraction, the MBW-derived PHBV was processed by electrospinning to yield defect-free ultrathin fibers, which were thermally post-treated. Annealing at 130 °C, well below the biopolymer's melting temperature (Tm), successfully yielded a continuous film resulting from coalescence of the electrospun fibrillar morphology, the so-called biopaper, exhibiting enhanced optical and color properties compared to traditional melt compounding routes. The crystallinity and crystalline morphology were comprehensively studied as a function of temperature by attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy and combined time-resolved synchrotron small- and wide-angle X-ray scattering (SAXS and WAXS) experiments, which clearly indicated that the molecular order within the copolyester was improved up to a maximum at 130 °C, and then it decreased at the biopolymer's Tm. It was hypothesized that by annealing at the temperature at which the thermally induced molecular order is maximized, the fibers generated sufficient mobility to align alongside, hence reducing surface energy and porosity. The data suggest that this material shows a good balance between enhanced mechanical and improved barrier properties to vapors and gases in comparison to traditional paper and other currently used petroleum-derived polymers, thus presenting significant potential to be part of innovative food biopackaging designs for the protection and preservation of foods in a circular bioeconomy scenario.

17.
Chemosphere ; 259: 127472, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32599378

RESUMO

In line with the Circular Economy approach, the production of polyhydroxyalkanoate (PHA) with organic waste as the feedstock may a biotechnological application to reduce waste and recover high-value materials. The potential contaminants that could transfer from bio-waste to a PHA include inorganic elements, such as heavy metals. Hence, the total content and migratability of certain elements were evaluated in several PHA samples produced from different origins and following different methods. The total content of certain elements in PHA ranged between 0.0001 (Be) and 49,500 mg kg-1 (Na). The concentrations of some alkaline (Na and K) and alkaline earth (Ca and Mg) metals were highest, which are of little environmental concern. The feedstock type and PHA stabilisation and extraction procedures affected the element contents. Several sets of experiments were conducted to evaluate the migration of elements from the PHA samples under different storage times, temperatures, and pH levels. The total contents of some heavy metals (As, Cd, Fe, Hg, Ni, Pb, and Zn) in PHA produced from fruit waste or crops (commercial PHA) were lower than those in the PHA samples produced from the mixture of the organic fraction of municipal waste and sludge from wastewater treatment. Both the PHA obtained by extraction from wet biomass (acid storage) with aqueous phase extraction reagents and commercial PHA were below the migration limits stipulated by the current Toy Safety Directive and by Commission Regulation (EU) October 2011 on plastic materials and articles intended to come into contact with food under frozen and refrigerated conditions.


Assuntos
Plásticos Biodegradáveis/análise , Plásticos/análise , Resíduos/análise , Biomassa , Biotecnologia , Alimentos , Metais Pesados/análise , Polímeros , Esgotos/química , Eliminação de Resíduos Líquidos , Águas Residuárias
18.
Polymers (Basel) ; 12(3)2020 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-32183353

RESUMO

The microbial synthesis of polyhydroxyalkanoates (PHA) from organic wastes is a valuable process to valorize available renewable resources, such as food wastes and biological sludge. Bioplastics find many applications in various sectors, from medical field to food industry. However, persistent organic pollutants could be transferred from wastes to the final product. The present paper demonstrates that the use of municipal wastes in PHA production is safe for the environment and human health and provides a polychlorinated biphenyl (PCB) profile in both commercial and waste-based PHA samples. PCB analysis in several PHA samples showed very low concentrations of the target analytes. Commercial PHA samples showed a similar PCB level with respect to PHA samples from municipal waste/sludge and higher than PHA samples from fruit waste. For all analyzed PCBs, detected concentrations were consistently lower than the ones reported in regulatory framework or guidelines.

19.
Oncol Rep ; 21(4): 1029-35, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19288005

RESUMO

The aim of this study was to evaluate the apoptotic damage to bone marrow cells caused by three chemotherapy regimens for advanced Hodgkin's lymphoma, ABVD, COPPEBVCAD and BEACOPP, which were randomly administered in the HD 2000 GISL trial. Bone marrow mononuclear cells (BMMCs) stained with anti-CD34 antibody and Annexin V, were evaluated by flow cytometry before starting chemotherapy, 30 days after completing chemotherapy and after 6 months. Results are expressed as the percentages of BMMCs positive to anti-CD34, to Annexin V or to both. Fourteen patients treated with ABVD, 11 with COPPEBVCAD and 13 with BEACOPP were evaluated before and 30 days after treatment. Late assessments were made in 6, 7 and 8 of them, respectively. No differences were found among the pretherapeutic flow cytometry findings in relation to the staging characteristics (marrow involvement included). All the regimens increased the apoptotic fraction of the whole mononuclear bone marrow cells (COPPEBVCAD did so significantly) and increased the CD34+ compartment (with significant early differences after ABVD and BEACOPP, tending to late persistence for ABVD, only). All the regimens increased the apoptotic CD34+ cells within the whole BMMC population (significantly after BEACOPP), although with a general trend to decrease in their percentage within the CD34+ compartment over time, even after the most dose-dense regimens. Based on the variations induced in the apoptotic fraction of all mononuclear and CD34+ cells, ABVD was the least toxic regimen and COPPEBVCAD the most toxic one.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Células-Tronco Hematopoéticas/efeitos dos fármacos , Doença de Hodgkin/tratamento farmacológico , Adolescente , Adulto , Idoso , Antígenos CD34/análise , Apoptose/efeitos dos fármacos , Bleomicina/efeitos adversos , Ciclofosfamida/efeitos adversos , Dacarbazina/efeitos adversos , Doxorrubicina/efeitos adversos , Etoposídeo/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prednisona/efeitos adversos , Procarbazina/efeitos adversos , Vimblastina/efeitos adversos , Vincristina/efeitos adversos
20.
Sci Total Environ ; 689: 765-773, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31280158

RESUMO

This study analyses the bacterial population dynamics of a mixed microbial community (MMC) selected in a pilot plant producing polyhydroxyalkanoate (PHA) from the fermentation of the organic fraction of urban waste (OFMSW) and sewage sludge (SS). 16S rRNA gene high-throughput sequencing revealed the occurrence of a variety of PHA accumulating bacteria that ensured a stable PHA production in an open system operating with real substrates and without temperature control. The Volatile Fatty Acids (VFA) changes in the feed and the temperature variation affected the dynamics of the PHA-accumulating bacteria over the plant operation. Remarkably, the higher PHA content was associated to a MMC largely comprising of Hydrogenophaga species during the operation at higher working temperature. The involvement of a heterogeneous PHA-accumulating MMC was associated with a high phaC synthase genes biodiversity confirming the occurrence of a functional redundancy.


Assuntos
Bactérias/genética , Fenômenos Fisiológicos Bacterianos , Microbiota , Poli-Hidroxialcanoatos/genética , Esgotos/análise , Águas Residuárias/análise , Bactérias/isolamento & purificação , Bactérias/metabolismo , Reatores Biológicos , Fermentação , Dinâmica Populacional , RNA Bacteriano/análise , RNA Ribossômico 16S/análise , Análise de Sequência de RNA
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