3,333 research outputs found
Expression of the High-Affinity K+ Transporter 1 (PpHKT1) Gene From Almond Rootstock ‘Nemaguard’ Improved Salt Tolerance of Transgenic Arabidopsis
Soil salinity affects plant growth and development, which directly impact yield. Plants deploy many mechanisms to cope with, or mitigate, salt stress. One of such mechanism is to control movement of ions from root to shoot by regulating the loading of Na+ in the transpiration stream. The high-affinity K+ transporter 1 (HKT1) is known to play a role in the removal of Na+from the xylem and bring it back to the root. As almond is a salt-sensitive crop, the rootstock plays an important role in successful almond cultivation in salt-affected regions. We currently lack knowledge on the molecular mechanisms involved in salt tolerance of almond rootstocks. In this study, we complemented the Arabidopsis athkt1 knockout mutant with HKT1 ortholog (PpHKT1) from the almond rootstock ‘Nemaguard’. Arabidopsis transgenic lines that were generated in athkt1 background with the constitutive promoter (PpHKT1OE2.2) and the native promoter (PpHKT1NP6) were subjected to different salt treatments. Both transgenic lines survived salt concentrations up to 120 mM NaCl, however, the mutant athkt1 died after 18 days under 120 mM NaCl. At 90 mM NaCl, the dry weight of athkt1 decreased significantly compared to the transgenic lines. Both transgenic lines showed significantly longer lateral roots compared to the athkt1 mutant at 80 mM NaCl treatment. The transgenic lines, PpHKT1OE2.2 and PpHKTNP6 had lower electrolyte leakage and higher relative water content compared to athkt1, suggesting that transgenic plants coped well with increased salt concentration by maintaining the integrity of the membranes. The expression analyses showed that PpHKT1 was induced in PpHKT1OE2.2 and PpHKTNP6 lines under salt treatment, which confirmed that both over-expression and native expression of PpHKT1 in the Arabidopsis mutant can complement salt tolerance function
Biological treatment of a contaminated gaseous emission containing monochlorobenzene
This study presents the operation of a biotrickling filter when treating a monochlorobenzene (MCB) contaminated gaseous
emission. Treatment dynamics were characterised by exposing the reactor to various MCB Organic Loads (OL). The use of
different growth support materials, namely limestone, sand, ceramic and PVC pall-rings, was investigated. Limestone led to
clogging of the reactor due to the accumulation of surface precipitates, but PVC pall-rings allowed for a uniform biofilm
growth. The biotrickling filter presented maximum removal efficiency (RE, 95%) under OL regimes of 10 g m-3-reactor h-1.
Treatment inhibition was observed when the reactor was exposed to OL of 45 g m-3-reactor h-1 with RE reaching a minimum
value (8%) and elimination capacity of 8 g m3-reactor h-1 The first half of the reactor height was the predominant section for
MCB biodegradation and increasing the mineral medium redrculation rate was beneficial for the overall treatment
Surface functionalization of cuttlefish bone-derived biphasic calcium phosphate scaffolds with polymeric coatings
Cuttlefish bone (CB) has been explored as biomaterial in the bone tissue-engineering field due to its unique porous structure and capacity of the aragonite mineral to be hydrothermally converted into calcium phosphates (CaPs). In the present study, undoped and ion (Sr2+, Mg2+ and/or Zn2+) doped biphasic calcium phosphate (BCP) scaffolds were prepared by hydrothermal transformation (HT, 200 °C, 24 h) of CB. The obtained scaffolds were sintered and then coated with two commercial polymers, poly(ε-caprolactone) (PCL) or poly(DL-lactide) (PDLA), and with two synthesized ones, a poly(ester amide) (PEA) or a poly(ester urea) (PEU) in order to improve their compressive strength. The scaffolds were characterized by X-ray diffraction (XRD) coupled with structural Rietveld refinement, Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). The results demonstrate that CB could be entirely transformed into BCPs in the presence or absence of doping elements. The initial CB structure was preserved and the polymeric coatings did not jeopardize the interconnected porous structure. Furthermore, the polymeric coatings enhanced the compressive strength of the scaffolds. The in vitro bio-mineralization upon immersing the scaffolds into simulated body fluid (SBF) demonstrated the formation of bone-like apatite surface layers in both uncoated and coated scaffolds. Overall, the produced scaffolds exhibit promising properties for bone tissue engineering applications.publishe
Fabrication, characterization and implementation of thermo resistive TiCu(N,O) thin films in a polymer injection mold
This paper presents the development of metallic thermoresistive thin film, providing an innovative solution to dynamically control the temperature during the injection molding process of polymeric parts. The general idea was to tailor the signal response of the nitrogen- and oxygen-doped titanium-copper thin film (TiCu(N,O))-based transducers, in order to optimize their use in temperature sensor devices. The results reveal that the nitrogen or oxygen doping level has an evident effect on the thermoresistive response of TiCu(N,O) films. The temperature coefficient of resistance values reached 2.29 × 10−2 °C−1, which was almost six times higher than the traditional platinum-based sensors. In order to demonstrate the sensing capabilities of thin films, a proof-of-concept experiment was carried out, integrating the developed TiCu(N,O) films with the best response in an injection steel mold, connected to a data acquisition system. These novel sensor inserts proved to be sensitive to the temperature evolution during the injection process, directly in contact with the polymer melt in the mold, demonstrating their possible use in real operation devices where temperature profiles are a major parameter, such as the injection molding process of polymeric parts.This work was supported by the project SAM—Smart Active Mold (contract ANI—33/SI/2015) by
the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding
UID/FIS/04650/2019, and from the Basque Government Industry Department under the ELKARTEK and
HAZITEK programs
Biological treatment of a contaminated gaseous emission from a leather industry in a suspended-growth bioreactor
A suspended-growth bioreactor (SGB) was operated for the treatment of a gaseous stream mimicking emissions generated at a leather industrial company. The main volatile
organic compounds (VOCs) present
in the gaseous stream consisted
of 1-methoxy-2-propanol,
2,6-dimethyl-4-heptanone,
2-butoxyethanol,
toluene
and butylacetate.
A microbial
consortium
able to degrade these VOCs was successfully
enriched. A laboratory-
scale SGB was established
and operated
for 210-d with an 8 h cycle period and with shutdowns
at weekends.
Along this period, the SGB was exposed to organic loads (OL) between 6.5 and 2.3 £ 102 g h¡1 m¡3. Most
of the compounds
were not detected at the outlet
of the SGB. The highest
total VOC removal efficiency
(RE)
(ca 99%) was observed when an OL of 1.6 £ 102 g h¡1 m¡3 was fed to the SGB. The maximum
total VOC elimination
capacity
(1.8 £ 102 g h¡1 m¡3) was achieved when the OL applied to the SGB was 2.3 £ 102 g h¡1 m¡3. For all
the operating
conditions,
the SGB showed high levels
of degradation
of toluene
and butylacetate
(RE t 100%).
This study also revealed that recirculation
of the gaseous
effluent
improved the performance
of the SGB. Overall,
the SGB was shown to be robust, showing
high performance
after night and weekend shutdown
periods.info:eu-repo/semantics/acceptedVersio
EdifÃcios de xisto no concelho de Peso da Régua
A pedra de xisto é um material natural e local comummente utilizado nas construções tradicionais do Concelho de Peso da Régua. Esta zona do Nordeste Português está inserida na região do Douro que é classificada como Património Mundial pela UNESCO. Os muros de divisão de terrenos, de suporte de terras e os edifÃcios de construção tradicional são os tipos de construção em que a pedra de xisto é o material dominante. Estas construções são parte integrante da paisagem e do património vernacular local, e por isso devem ser valorizados e preservados. Através deste trabalho de investigação foi possÃvel realizar um levantamento dos edifÃcios de xisto existentes neste concelho, e reunir um conjunto de informações técnicas e construtivas que os caracterizam. Este artigo pretende divulgar informação técnica relativa a detalhes construtivos deste tipo de construção tradicional, focada principalmente nas suas especificidades estruturais. No contexto estrutural, as paredes de alvenaria de pedra de xisto são os elementos estruturais verticais principais. As dimensões e constituição das paredes, dos vãos de janela e de porta, dos cunhais e das padieiras são alguns dos aspectos técnicos e construtivos que merecem especial destaque, tendo em conta que podem influenciar de forma decisiva o comportamento estrutural deste elemento construtivo. Deste modo, pretende-se contribuir para o conhecimento deste tipo de construção, e disponibilizar informação base que possa suportar estudos futuros de modelação numérica e/ou ensaios experimentais do comportamento de paredes em alvenaria de pedra de xisto
Eco-friendly methods for extraction and modification of cellulose: an overview
Cellulose is the most abundant renewable polymer on Earth and can be obtained from several different sources, such as trees, grass, or biomass residues. However, one of the issues is that not all the fractionation processes are eco-friendly and are essentially based on cooking the lignocellulose feedstock in a harsh chemical mixture, such as NaOH + Na2S, and water, to break loose fibers. In the last few years, new sustainable fractionation processes have been developed that enable the obtaining of cellulose fibers in a more eco-friendly way. As a raw material, cellulose’s use is widely known and established in many areas. Additionally, its products/derivatives are recognized to have a far better environmental impact than fossil-based materials. Examples are textiles and packaging, where forest-based fibers may contribute to renewable and biodegradable substitutes for common synthetic materials and plastics. In this review, some of the main structural characteristics and properties of cellulose, recent green extraction methods/strategies, chemical modification, and applications of cellulose derivatives are discussed.BDE 05|POCI-01-0247-FEDER021874; 2022.07519.PTDCinfo:eu-repo/semantics/publishedVersio
Measurement of the 70Ge(n,γ) cross section up to 300 keV at the CERN n_TOF facility
Neutron capture data on intermediate mass nuclei are of key importance to nucleosynthesis in the weak component of the slow neutron capture processes, which occurs in massive stars. The (n,γ) cross section on 70Ge, which is mainly produced in the s process, was measured at the neutron time-of-flight facility n_TOF at CERN. Resonance capture kernels were determined up to 40 keV neutron energy and average cross sections up to 300 keV. Stellar cross sections were calculated from kT =5 keV tokT =100 keV and are in very good agreement with a previous measurement by Walter and Beer (1985) and recent evaluations. Average cross sectionsareinagreementwithWalterandBeer(1985)overmostoftheneutronenergyrangecovered,whilethey aresystematicallysmallerforneutronenergiesabove150keV.Wehavecalculatedisotopicabundancesproduced in s-process environments in a 25 solar mass star for two initial metallicities (below solar and close to solar). While the low metallicity model reproduces best the solar system germanium isotopic abundances, the close to solar model shows a good global match to solar system abundances in the range of mass numbers A=60–80.Austrian Science Fund J3503Adolf Messer Foundation ST/M006085/1European Research Council ERC2015-StGCroatian Science Foundation IP-2018-01-857
Left ventricular end diastolic pressure and acute coronary syndromes
BACKGROUND: Data is lacking in the literature regarding the prognostic impact of left ventricular-end diastolic pressure (LVEDP) across acute coronary syndromes (ACS).
OBJECTIVE: To assess LVEDP and its prognostic implications in ACS patients.
METHODS: Prospective, longitudinal and continuous study of 1329 ACS patients from a single center between 2004 and 2006. Diastolic function was determined by LVEDP. Population was divided in two groups: A - LVEDP 26.5 mmHg (n = 226).
RESULTS: There were no significant differences between groups with respect to risk factors for cardiovascular disease, medical history and medical therapy during admission. In group A, patients with non-ST elevation ACS were more frequent, as well as normal coronary angiograms. In-hospital mortality was similar between groups, but one-year survival was higher in group A patients (96.9 vs 91.2%, log rank p = 0.002). On a multivariate Cox regression model, a LVEDP > 26.5 mmHg (HR 2.45, 95%CI 1.05 - 5.74) remained an independent predictor for one-year mortality, when adjusted for age, LV systolic ejection fraction, ST elevation ACS, peak troponin, admission glycemia, and diuretics at 24 hours. Also, a LVEDP > 26.5 mmHg was an independent predictor for a future readmission due to congestive HF (HR 6.65 95%CI 1.74 - 25.5).
CONCLUSION: In our selected population, LVEDP had a significant prognostic influence
Long-term performance and microbial dynamics of an up-flow fixed bed reactor established for the biodegradation of fluorobenzene
An up-flow fixed bed reactor (UFBR) was established
to investigate the biodegradation of fluorobenzene
(FB) under a number of operating conditions, which
included variation in the concentration of FB in the feed
stream (up to 180 mg l−1) and temporary suspension of
feeding. Degradation of FB was followed for a period of
8 months under a continuous flow regime. During the operation
of the UFBR, FB was never detected in the reactor
effluent, being biodegraded by the microbial biofilm or
adsorbed to the granular activated carbon (GAC). Biodegradation
of FB was observed from the beginning of the
reactor operation, and overall, it accounted for 50% of the
total amount fed to the bioreactor. High organic loads of FB
(210–260 mg d−1 dm−3) were found to affect the biological
removal efficiency, possibly due to an inhibitory effect
caused by the higher FB concentrations fed to the bioreactor
(149–179 mg l−1). When FB feeding was suspended for
1 month, biodegradation continued, indicating that the
adsorbed FB became bioavailable. Biofilm bacterial dynamics
were followed throughout the UFBR operation by
denaturing gradient gel electrophoresis and plate-counting
techniques, showing that a quite stable community was
found in the bioreactor, and this was mainly attributed to the
high selective pressure exerted by the presence of FB
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