Carotenoids are lipophilic isoprenoid compounds synthesized by all photosynthetic organisms and some non-photosynthetic prokaryotes and fungi. With some notable exceptions, animals (including humans) ...do not produce carotenoids de novo but take them in their diets. In photosynthetic systems carotenoids are essential for photoprotection against excess light and contribute to light harvesting, but perhaps they are best known for their properties as natural pigments in the yellow to red range. Carotenoids can be associated to fatty acids, sugars, proteins, or other compounds that can change their physical and chemical properties and influence their biological roles. Furthermore, oxidative cleavage of carotenoids produces smaller molecules such as apocarotenoids, some of which are important pigments and volatile (aroma) compounds. Enzymatic breakage of carotenoids can also produce biologically active molecules in both plants (hormones, retrograde signals) and animals (retinoids). Both carotenoids and their enzymatic cleavage products are associated with other processes positively impacting human health. Carotenoids are widely used in the industry as food ingredients, feed additives, and supplements. This review, contributed by scientists of complementary disciplines related to carotenoid research, covers recent advances and provides a perspective on future directions on the subjects of carotenoid metabolism, biotechnology, and nutritional and health benefits.
The sequential solid/gas single-crystal to single-crystal reaction of Rh(Cy2P(CH2)3PCy2)(COD)BArF 4 (COD = cyclooctadiene) with H2 or D2 was followed in situ by solid-state 31P{1H} NMR ...spectroscopy (SSNMR) and ex situ by solution quenching and GC-MS. This was quantified using a two-step Johnson–Mehl–Avrami–Kologoromov (JMAK) model that revealed an inverse isotope effect for the second addition of H2, that forms a σ-alkane complex Rh(Cy2P(CH2)3PCy2)(COA)BArF 4. Using D2, a temporal window is determined in which a structural solution for this σ-alkane complex is possible, which reveals an η2,η2-binding mode to the Rh(I) center, as supported by periodic density functional theory (DFT) calculations. Extensive H/D exchange occurs during the addition of D2, as promoted by the solid-state microenvironment.
•Review of recent studies centered on BIM-based LCA.•Focus on the way that BIM can contribute to simplify input and optimize output.•Most of reviewed papers are focused on CO2 emission ...calculation.•Study evidences the need to establish guidelines to assist in BIM-LCA integration.
Current environmental problems arising from the building sector require tools to help reduce resource consumption and environmental impact. Life Cycle Assessment (LCA) is a widely used tool to quantify the environmental impacts of the building sector. The literature recognizes the need to simplify the method application, especially to reduce and optimize data acquisition. Building Information Modeling (BIM) is defined as a virtual 3D building model which integrates with a database of their building elements. Several studies recognize that the integration of BIM and LCA can simplify data acquisition of the building as well as provide both tools with feedback. This paper reviews recent studies centered on BIM-based LCA, and also carries out a methodological analysis of their integration, focusing on the way that BIM can contribute to simplifying data input, and optimize output data and results during the LCA application in buildings. The results show the viability to develop methods based on BIM models for organizing building information used to estimate environmental and energy consumption impacts based on LCA, including: templates and plug-ins for BIM software, and the integration of automated processes combining different data and software. Reviewed papers are simplified LCA applications, mostly focused on CO2 emission calculation during the early stages of design. Finally, methodological challenges and recommendations for BIM and LCA tools are propose.
Attenuated total reflectance-Fourier transform infrared (FTIR-ATR) spectroscopy was applied to 120 samples of heartwood rings from eight individual pine trees from different locations in Spain.
Pinus ...sylvestris
cores were collected at the Artikutza natural park (Ps-ART).
Pinus nigra
cores were collected in Sierra de Cazorla (Pn-LIN) and in La Sagra Mountain (Pn-LSA). Three discriminant analysis tests were performed using all bands (DF
T
), lignin bands only (DF
L
) and polysaccharides bands only (DF
P
), to explore the ability of FTIR-ATR to separate between species and growing location. The DF
L
model enabled a good separation between pine species, whereas the DF
P
model enabled differentiation for both species and growing location. The DF
T
model enabled virtually perfect separation, based on two functions involving twelve FTIR bands. Discrimination between species was related to bands at 860 and 1655 cm
−1
, which were more intense in
P. sylvestris
samples, and bands at 1425 and 1635 cm
−1
, more intense in
P. nigra
samples. These vibrations were related to differences in lignin structure and polysaccharide linear chains. Discrimination between growing locations was mainly related to polysaccharide absorptions: at 900, 1085 and 1335 cm
−1
more representative of Pn-LIN samples, and at 1105 and 1315 cm
−1
mostly associated to Pn-LSA samples. These absorptions are related to β-glycosidic linkages (900 cm
−1
), cellulose and hemicellulose (C–O bonds, 1085 and 1105 cm
−1
) and content in amorphous/crystalline cellulose (1315 and 1335 cm
−1
). These results show that FTIR-ATR in combination with multivariate statistics can be a useful tool for species identification and provenancing for pine wood samples of unknown origin.
Bimetallic sodium magnesiates have been employed in metal-halogen exchange for the first time. Utilising the racemic phenoxide ligand 5,5′,6,6′-tetramethyl-3,3′-di-
tert
...-butyl-1,1′-biphenyl-2,2′-diol (
rac
)-BIPHEN-H
2
, the dialkyl sodium magnesiates (
rac
)-BIPHENNa
2
MgBu
2
(TMEDA)
2
3
and (
rac
)-BIPHENNa
2
MgBu
2
(PMDETA)
2
4
have been synthesised. Both
3
and
4
can be easily prepared through co-complexation of di-
n
-butylmagnesium with the sodiated (
rac
)-BIPHEN precursor which can be prepared
in situ
in hydrocarbon solvent. Prior to the main investigation, synthesis of the sodiated precursor BIPHEN
2
Na
4
(THF)
4
1
was explored in order to better understand the formation of sodium magnesiates utilising the dianionic (
rac
)-BIPHEN ligand as the parent ligand. In addition, a BIPHEN-rich sodium magnesiate BIPHEN
2
Na
2
Mg(THF)
4
2
was prepared and characterised, and its formation was rationalised. Complex
1
and
4
have also been fully characterised in both solid and solution state. In terms of onward reactivity,
3
and
4
have been tested as potential exchange reagents with aryl and heteroaryl iodides to produce aryl and heteroaryl magnesium phenoxides utilising toluene as a non-polar hydrocarbon solvent. Complex
3
reacted smoothly to give a range of aryl and heteroaryl magnesium phenoxides, whilst
4
′s reactivity is more sluggish.
Sodium magnesiates incorporating the (
rac
)-BIPHEN ligand have been prepared and characterised and subsequently used in metal-halogen exchange reactions.
In certain unconventional superconductors with sizable electronic correlations, the availability of closely competing pairing channels leads to characteristic soft collective fluctuations of the ...order parameters, which leave fingerprints in many observables and allow the phase competition to be scrutinized. Superconducting layered materials, where electron–electron interactions are enhanced with decreasing thickness, are promising candidates to display these correlation effects. In this work, the existence of a soft collective mode in single‐layer NbSe2, observed as a characteristic resonance excitation in high‐resolution tunneling spectra is reported. This resonance is observed along with higher harmonics, its frequency Ω/2Δ is anticorrelated with the local superconducting gap Δ, and its amplitude gradually vanishes by increasing the temperature and upon applying a magnetic field up to the critical values (TC and HC2), which sets an unambiguous link to the superconducting state. Aided by a microscopic model that captures the main experimental observations, this resonance is interpreted as a collective Leggett mode that represents the fluctuation toward a proximate f‐wave triplet state, due to subleading attraction in the triplet channel. These findings demonstrate the fundamental role of correlations in superconducting 2D transition metal dichalcogenides, opening a path toward unconventional superconductivity in simple, scalable, and transferable 2D superconductors.
The experimental observation of Leggett collective modes in the superconducting state of a 2D transition metal dichalcogenide (TMD) is reported. Leggett modes have been rarely seen in nature and represent the first type of collective modes observed in 2D TMD superconductors, which highlights the rather unconventional superconducting properties of this family of materials in the single‐layer limit.
There is an increasing trend in the consumption of olive oil, especially extra virgin olive oil, due to its health benefits. These health benefits are mainly correlated to health-promoting components ...of olive oil such as polyphenols, tocopherols, and carotenoids, positive effects of olive oil on the inhibition of foodborne pathogens, stimulation of the growth of beneficial microorganisms, and its antioxidant activity. These attributes make olive oil one of the leading healthy edible oils worldwide.
The current study overviews the recent findings on the health benefits of olive oil consumption including its effects on gut microbiota, its antioxidant activity, and its ability in preventing cardiovascular disease (CVD). In addition, the potential mechanism involved in these health-promoting effects are discussed.
Key findings and conclusions: This study showed that olive oils originated from various regions of the world can pose some positive effects on gut microbiota. Moreover, this edible oil (especially the extra virgin type) can prevent CVD due to the high levels of valuable bioactive components including phenolic compounds (e.g. oleocanthal, tyrosol, hydroxytyrosol, oleuropein, and oleuropein aglycone) and the presence of highly bioavailable health-promoting carotenoids such as provitamin A, β-carotene, and lutein. Furthermore, the oral intake of extra virgin olive oil can be beneficial in preventing cancer and type 2 diabetes. Therefore, the consumption of olive oil, especially the extra virgin type, can be recommended not only because of its healthy fatty acid profile (particularly oleic acid) but also due to valuable positive effects of its bioactive components on human health.
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•Olive oil, especially,extra virgin olive oil (EVOO), contains bioactive compounds (e.g., polyphenols).•Fatty acid profile of EVOO is rich in oleic acid which possess beneficial health effects.•EVOO could improve health through positive effects on gut microbiota.•EVOO could reduce the risk of cardiovascular diseases.•EVOO could reduce the risk of hypertension, type 2 diabetes, and cancer.
Rhodium-alkene complexes of the pincer ligand κ3-C5H3N-2,6-(OPiPr2)2 (PONOP-iPr) have been prepared and structurally characterized: Rh(PONOP-iPr)(η2-alkene)BArF 4 alkene = cyclooctadiene (COD), ...norbornadiene (NBD), ethene; ArF = 3,5-(CF3)2C6H3. Only one of these, alkene = COD, undergoes a reaction with H2 (1 bar), to form Rh(PONOP-iPr)(η2-COE)BArF 4 (COE = cyclooctene), while the others show no significant reactivity. This COE complex does not undergo further hydrogenation. This difference in reactivity between COD and the other alkenes is proposed to be due to intramolecular alkene-assisted reductive elimination in the COD complex, in which the η2-bound diene can engage in bonding with its additional alkene unit. H/D exchange experiments on the ethene complex show that reductive elimination from a reversibly formed alkyl hydride intermediate is likely rate-limiting and with a high barrier. The proposed final product of alkene hydrogenation would be the dihydrogen complex Rh(PONOP-iPr)(η2-H2)BArF 4, which has been independently synthesized and undergoes exchange with free H2 on the NMR time scale, as well as with D2 to form free HD. When the H2 addition to Rh(PONOP-iPr)(η2-ethene)BArF 4 is interrogated using pH2 at higher pressure (3 bar), this produces the dihydrogen complex as a transient product, for which enhancements in the 1H NMR signal for the bound H2 ligand, as well as that for free H2, are observed. This is a unique example of the partially negative line-shape effect, with the enhanced signals that are observed for the dihydrogen complex being explained by the exchange processes already noted.
Most physical and other natural systems are complex entities composed of a large number of interacting individual elements. It is a surprising fact that they often obey the so-called scaling laws ...relating an observable quantity with a measure of the size of the system. Here we describe the discovery of universal superlinear metabolic scaling laws in human cancers. This dependence underpins increasing tumour aggressiveness, due to evolutionary dynamics, which leads to an explosive growth as the disease progresses. We validated this dynamic using longitudinal volumetric data of different histologies from large cohorts of cancer patients. To explain our observations we put forward increasingly-complex biologically-inspired mathematical models that captured the key processes governing tumor growth. Our models predicted that the emergence of superlinear allometric scaling laws is an inherently three-dimensional phenomenon. Moreover, the scaling laws thereby identified allowed us to define a set of metabolic metrics with prognostic value, thus providing added clinical utility to the base findings.
H
3
B·NMe
3
σ-complexes of d
8
(
L1
)RhBAr
F
4
and d
10
(
L1
)AgBAr
F
4
(where
L1
= 2,6-bis-1-(2,6-diisopropylphenylimino)ethylpyridine) have been prepared and structurally characterised. Analysis ...of the molecular and electronic structures reveal important but subtle differences in the nature of the bonding in these σ-complexes, which differ only by the identity of the metal centre and the d-electron count. With Rh the amine-borane binds in an η
2
:η
2
fashion, whereas at Ag the unsymmetrical {Ag H
3
B·NMe
3
} unit suggests a structure lying between the η
2
:η
2
and η
1
extremes.
The bonding in H
3
B·NMe
3
σ-complexes of d
8
-Rh(
i
) and d
10
-Ag(
i
) show subtle differences, as probed by structural, spectroscopic and computational studies.
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