The renewed interest in the use of hybrid zones for studying speciation calls for the identification and study of hybrid zones across a wide range of organisms, especially in long‐lived taxa for ...which it is often difficult to generate interpopulation variation through controlled crosses. Here, we report on the extent and direction of introgression between two members of the ‘model tree’ genus Populus: Populus alba (white poplar) and Populus tremula (European aspen), across a large zone of sympatry located in the Danube valley. We genotyped 93 hybrid morphotypes and samples from four parental reference populations from within and outside the zone of sympatry for a genome‐wide set of 20 nuclear microsatellites and eight plastid DNA restriction site polymorphisms. Our results indicate that introgression occurs preferentially from P. tremula to P. alba via P. tremula pollen. This unidirectional pattern is facilitated by high levels of pollen vs. seed dispersal in P. tremula (pollen/seed flow = 23.9) and by great ecological opportunity in the lowland floodplain forest in proximity to P. alba seed parents, which maintains gene flow in the direction of P. alba despite smaller effective population sizes (Ne) in this species (P. alba Nec. 500–550; P. tremula Nec. 550–700). Our results indicate that hybrid zones will be valuable tools for studying the genetic architecture of the barrier to gene flow between these two ecologically divergent Populus species.
Superconductivity originates from the formation of bound (Cooper) pairs of electrons that can move through the lattice without resistance below the superconducting transition temperature Tc (ref.). ...Electron Cooper pairs in most superconductors form anti-parallel spin singlets with total spin S = 0 (ref.), although they can also form parallel spin-triplet Cooper pairs with S = 1 and an odd parity wavefunction3. Spin-triplet pairing is important because it can host topological states and Majorana fermions relevant for quantum computation. Because spin-triplet pairing is usually mediated by ferromagnetic (FM) spin fluctuations, uranium-based materials near an FM instability are considered to be ideal candidates for realizing spin-triplet superconductivity. Indeed, UTe2, which has a Tc ≈ 1.6 K (refs.), has been identified as a candidate for a chiral spin-triplet topological superconductor near an FM instability, although it also has antiferromagnetic (AF) spin fluctuations. Here we use inelastic neutron scattering (INS) to show that superconductivity in UTe2 is coupled to a sharp magnetic excitation, termed resonance, at the Brillouin zone boundary near AF order. Because the resonance has only been found in spin-singlet unconventional superconductors near an AF instability, its observation in UTe2 suggests that AF spin fluctuations may also induce spin-triplet pairing or that electron pairing in UTe2 has a spin-singlet component.
Type 2 diabetes mellitus (T2DM) and metabolic syndrome (MetS) are diseases caused by the interaction of genetic and non-genetic factors. Therefore, the aim of our study was to investigate the ...association between six common genetic polymorphisms and T2DM and MetS in males. A total of 120 T2DM, 75 MetS, and 120 healthy controls (HC) were included in the study.
ID,
4a/b,
A1166C,
(A>G),
+35A/C,
-21A/T gene polymorphisms were genotyped by PCR or PCR-RFLP techniques. T2DM was diagnosed at an earlier age compared to MetS (54 vs 55 years old, p=0.0003) and the difference was greater in carriers of the
G allele (54 vs 56 years old, p=0.0002) or both
G and
b alleles (54 vs 56, p=0.00016). The
AA genotype (O.R.=0.11, p=0.0006) and the presence of both
I and
A (O.R.=0.39, p=0.0005) alleles revealed to be protective for T2DM.
AA and AC genotypes were protective factors for triglyceride (p=0.0002 and p=0.0005, respectively) and HDL cholesterol (p=0.0002 and p=0.0004, respectively) levels in T2DM patients.
DD was identified more frequently in hypertensive T2DM patients (O.R.=3.77, p=0.0005) and in those who reported drinking alcohol (p=0.0001) comparing to HC and T2DM patients who did not drink alcohol, respectively. We observed that T2DM patients who reported drinking alcohol had an increased frequency of
DD and
bb (p<0.0001), or
DD and
G (p<0.0001) compared to non-drinkers. No gene polymorphisms were associated with MetS.
Non-alcoholic fatty liver disease (NAFLD) appears to be independently associated with the development of atherosclerosis. The biological mechanisms underlying this association are complex, and likely ...involve liver-resident cell types other than hepatocytes. Thus, we review recent evidence that non-parenchymal hepatic cell responses to lipid excess contribute to the pathogenesis of both NAFLD and atherosclerosis.
Significant independent associations between NAFLD and atherosclerosis have been identified through cross-sectional studies and meta-analyses. Mechanistic studies in cell cultures and in rodent models suggest that liver-resident macrophages, activated hepatic stellate cells (HSC) and liver sinusoidal endothelial cells (LSEC) mount lipotoxic responses under NAFLD conditions which can contribute to the progression of both NAFLD and atherosclerosis.
Non-parenchymal hepatic cell types exhibit some similarity in their responses to lipid excess, and in their pathogenic mechanisms, which likely contribute to the coordinated progression of NAFLD and atherosclerosis. In response to lipotoxic conditions, macrophages, Kupffer cells and HSC initiate robust inflammatory responses, whereas LSEC generate excess reactive oxygen species (ROS). The extent to which inflammatory cytokines and ROS produced by non-parenchymal cells contribute to the progression of both NAFLD and atherosclerosis warrants further investigation.
Medicinal use of mushrooms has been documented since ancient times, and in the modern world, mushrooms have a longstanding history of use in Eastern medicine. Recent interest in plant-based diets in ...Westernized countries has brought increasing attention to the use of mushrooms and mushroom-derived compounds in the prevention and treatment of chronic diseases. Edible mushrooms are the most abundant food sources of the modified amino acid, ergothioneine. This compound has been shown to accumulate in almost all cells and tissues, but preferentially in those exposed to oxidative stress and injury. The demonstrated cytoprotectant effect of ergothioneine has led many to suggest a potential therapeutic role for this compound in chronic conditions that involve ongoing oxidative stress and inflammation, including cardiovascular and metabolic diseases. However, the in vivo effects of ergothioneine and its underlying therapeutic mechanisms in the whole organism are not as clear. Moreover, there are no well-defined, clinical prevention and intervention trials of ergothioneine in chronic disease. This review highlights the cellular and molecular mechanisms of action of ergothioneine and its potential as a Traditional, Complementary and Alternative Medicine for the promotion of cardiometabolic health and the management of the most common manifestations of cardiometabolic disease.
Abstract
Recent experiments in multiband Fe-based and heavy-fermion superconductors have challenged the long-held dichotomy between simple
s
- and
d
-wave spin-singlet pairing states. Here, we ...advance several time-reversal-invariant irreducible pairings that go beyond the standard singlet functions through a matrix structure in the band/orbital space, and elucidate their naturalness in multiband systems. We consider the
s
τ
3
multiorbital superconducting state for Fe-chalcogenide superconductors. This state, corresponding to a
d
+
d
intra- and inter-band pairing, is shown to contrast with the more familiar
d
+ i
d
state in a way analogous to how the B- triplet pairing phase of
3
He superfluid differs from its A- phase counterpart. In addition, we construct an analog of the
s
τ
3
pairing for the heavy-fermion superconductor CeCu
2
Si
2
, using degrees-of-freedom that incorporate spin-orbit coupling. Our results lead to the proposition that
d
-wave superconductors in correlated multiband systems will generically have a fully-gapped Fermi surface when they are examined at sufficiently low energies.
Abstract
The surface states of 3D topological insulators in general have negligible quantum oscillations (QOs) when the chemical potential is tuned to the Dirac points. In contrast, we find that ...topological Kondo insulators (TKIs) can support surface states with an arbitrarily large Fermi surface (FS) when the chemical potential is pinned to the Dirac point. We illustrate that these FSs give rise to finite-frequency QOs, which can become comparable to the extremal area of the unhybridized bulk bands. We show that this occurs when the crystal symmetry is lowered from cubic to tetragonal in a minimal two-orbital model. We label such surface modes as ‘shadow surface states’. Moreover, we show that the sufficient next-nearest neighbor out-of-plane hybridization leading to shadow surface states can be self-consistently stabilized for tetragonal TKIs. Consequently, shadow surface states provide an important example of high-frequency QOs beyond the context of cubic TKIs.
BackgroundPatients that recovered from COVID-19 may remain with symptoms which can persist for an uncertain period of time. AimThe purpose of this study was to investigate the reasons why patients ...who passed the acute phase of COVID-19 presented themselves to the Emergency Department. Patients and MethodsWe selected 87 patients admitted to the Emergency Department of the Bucharest University Emergency Hospital between 01.01.2021-31.05.2021. Patients had pulmonary fibrosis (11.49%), pleural effusion (16.09%) or a history of hypertension (73.56%), type 2 diabetes (42.53%), stroke (24.14%), malignant diseases (10.34%). ResultsAssociation between neutrophil levels and acute stroke and between fibrinogen levels and alveolar condensation were identified. The percentage of deaths was significantly higher in the subgroup of subjects that had maxim 11 days of hospitalization (p=0.004); we observed a trend of association between the age of more than 51 years old and admission in the Emergency Unit at less than a month after the SARS Cov2 infection, the positive result at the RT-PCR test or a lung damage of over 30% (p<0.05). ConclusionA significant percentage of patients that were admitted to the Emergency Unit post COVID-19 had chronic pathologies and their characteristics were associated with neutrophilia, high fibrinogen levels or length of hospitalization.
Abstract
An important challenge in condensed matter physics is understanding iron-based superconductors. Among these systems, the iron selenides hold the record for highest superconducting transition ...temperature and pose especially striking puzzles regarding the nature of superconductivity. The pairing state of the alkaline iron selenides appears to be of
d
-wave type based on the observation of a resonance mode in neutron scattering, while it seems to be of
s
-wave type from the nodeless gaps observed everywhere on the Fermi surface. Here we propose an orbital-selective pairing state, dubbed
sτ
3
, as a natural explanation of these disparate properties. The pairing function, containing a matrix
τ
3
in the basis of 3
d
-electron orbitals, does not commute with the kinetic part of the Hamiltonian. This dictates the existence of both intraband and interband pairing terms in the band basis. A spin resonance arises from a
d
-wave-type sign change in the intraband pairing component, whereas the quasiparticle excitation is fully gapped on the FS due to an
s
-wave-like form factor associated with the addition in quadrature of the intraband and interband pairing terms. We demonstrate that this pairing state is energetically favored when the electron correlation effects are orbitally selective. More generally, our results illustrate how the multiband nature of correlated electrons affords unusual types of superconducting states, thereby shedding new light not only on the iron-based materials but also on a broad range of other unconventional superconductors such as heavy fermion and organic systems.
Cell dysfunction and death induced by lipid accumulation in nonadipose tissues, or lipotoxicity, may contribute to the pathogenesis of obesity and type 2 diabetes. However, the mechanisms leading to ...lipotoxic cell death are poorly understood. We recently reported that, in Chinese hamster ovary (CHO) cells and in H9c2 cardiomyoblasts, lipid overload induced by incubation with 500 μM palmitate leads to intracellular accumulation of reactive oxygen species, which subsequently induce endoplasmic reticulum (ER) stress and cell death. Here, we show that palmitate also impairs ER function through a more direct mechanism. Palmitate was rapidly incorporated into saturated phospholipid and triglyceride species in microsomal membranes of CHO cells. The resulting membrane remodeling was associated with dramatic dilatation of the ER and redistribution of protein-folding chaperones to the cytosol within 5 h, indicating compromised ER membrane integrity. Increasing β-oxidation, through the activation of AMP-activated protein kinase, decreased palmitate incorporation into microsomes, decreased the escape of chaperones to the cytosol, and decreased subsequent caspase activation and cell death. Thus, palmitate rapidly increases the saturated lipid content of the ER, leading to compromised ER morphology and integrity, suggesting that impairment of the structure and function of this organelle is involved in the cellular response to fatty acid overload.
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