225 research outputs found
Phonon-induced rotation of the electronic nematic director in superconducting BiSe
The doped topological insulator , with
, becomes a nematic superconductor
below . The associated electronic nematic director is
described by an angle and is experimentally manifested in the
elliptical shape of the in-plane critical magnetic field . Because of
the threefold rotational symmetry of the lattice, is expected to align
with one of three high-symmetry directions corresponding to the in-plane
nearest-neighbor bonds, consistent with a -Potts nematic transition.
Here, we show that the nematic coupling to the acoustic phonons, which makes
the nematic correlation length tend to diverge along certain directions only,
can fundamentally alter this phenomenology in trigonal lattices. Compared to
hexagonal lattices, the former possesses a sixth independent elastic constant
due to the fact that the in-plane shear strain doublet
and the out-of-plane shear
strain doublet transform as the same
irreducible representation. We find that, when overcomes a threshold
value, which is expected to be the case in doped , the
nematic director unlocks from the high-symmetry directions due to the
competition between the quadratic phonon-mediated interaction and the cubic
nematic anharmonicity. This implies the breaking of the residual in-plane
twofold rotational symmetry (), resulting in a triclinic phase. We
discuss the implications of these findings to the structure of nematic domains
and to the shape of the in-plane in , and
to presence of nodes inside the superconducting state.Comment: 24 pages, 10 figure
Cascade of vestigial orders in two-component superconductors: Nematic, ferromagnetic, -wave charge- , and -wave charge- states
A Closer Look on the Polyhydroxybutyrate- (PHB-) Negative Phenotype of Ralstonia eutropha PHB-4
The undefined poly(3-hydroxybutyrate)- (PHB-) negative mutant R. eutropha PHB-4
was generated in 1970 by 1-nitroso-3-nitro-1-methylguanidine (NMG)
treatment. Although being scientific relevant, its genotype remained
unknown since its isolation except a recent first investigation. In this
study, the mutation causing the PHA-negative phenotype of R. eutropha PHB-4 was confirmed independently: sequence analysis of the phaCAB operon identified a G320A mutation in phaC yielding a stop codon, leading to a massively truncated PhaC protein of 106 amino acids (AS) in R. eutropha PHB-4 instead of 589 AS in the wild type. No other mutations were observed within the phaCAB operon. As further mutations probably occurred in the genome of mutant PHB-4
potentially causing secondary effects on the cells' metabolism, the
main focus of the study was to perform a 2D PAGE-based proteome analysis
in order to identify differences in the proteomes of the wild type and
mutant PHB-4. A total of 20 differentially expressed proteins
were identified which provide valuable insights in the metabolomic
changes of mutant PHB-4. Besides excretion of pyruvate, mutant PHB-4
encounters the accumulation of intermediates such as pyruvate and
acetyl-CoA by enhanced expression of the observed protein species: (i)
ThiJ supports biosynthesis of cofactor TPP and thereby reinforces the
2-oxoacid dehydrogenase complexes as PDHC, ADHC and OGDHC in order to
convert pyruvate at a higher rate and the (ii) 3-isopropylmalate
dehydrogenase LeuB3 apparently directs pyruvate to synthesis of several
amino acids. Different (iii) acylCoA-transferases enable transfer
reactions between organic acid intermediates, and (iv) citrate lyase
CitE4 regenerates oxaloacetate from citrate for conversion with
acetyl-CoA in the TCC in an anaplerotic reaction. Substantial amounts of
reduction equivalents generated in the TCC are countered by (v)
synthesis of more ubiquinones due to enhanced synthesis of MenG2 and
MenG3, thereby improving the respiratory chain which accepts electrons
from NADH and succinate
Gamma-glutamyltransferase is a strong predictor of secondary sclerosing cholangitis after lung transplantation for COVID-19 ARDS
Background: Lung transplantation (LTx) can be considered for selected patients suffering from COVID-19 acute respiratory distress syndrome (ARDS). Secondary sclerosing cholangitis in critically ill (SSC-CIP) patients has been described as a late complication in COVID-19 ARDS survivors, however, rates of SSC-CIP after LTx and factors predicting this detrimental sequela are unknown. Methods: This retrospective analysis included all LTx performed for post-COVID ARDS at 8 European LTx centers between May 2020 and January 2022. Clinical risk factors for SSC-CIP were analyzed over time. Prediction of SSC-CIP was assessed by ROC-analysis. Results: A total of 40 patients were included in the analysis. Fifteen patients (37.5%) developed SSC-CIP. GGT at the time of listing was significantly higher in patients who developed SSC-CIP (median 661 (IQR 324-871) vs 186 (109-346); p = 0.001). Moreover, higher peak values for GGT (585 vs 128.4; p < 0.001) and ALP (325 vs 160.2; p = 0.015) were found in the ‘SSC’ group during the waiting period. Both, GGT at the time of listing and peak GGT during the waiting time, could predict SSC-CIP with an AUC of 0.797 (95% CI: 0.647-0.947) and 0.851 (95% CI: 0.707-0.995). Survival of ‘SSC’ patients was severely impaired compared to ‘no SSC’ patients (1-year: 46.7% vs 90.2%, log-rank p = 0.004). Conclusions: SSC-CIP is a severe late complication after LTx for COVID-19 ARDS leading to significant morbidity and mortality. GGT appears to be a sensitive parameter able to predict SSC-CIP even at the time of listing
Thyrotropin-releasing hormone (TRH) promotes wound re-epithelialisation in frog and human skin
There remains a critical need for new therapeutics that promote wound healing in patients suffering from chronic skin wounds. This is, in part, due to a shortage of simple, physiologically and clinically relevant test systems for investigating candidate agents. The skin of amphibians possesses a remarkable regenerative capacity, which remains insufficiently explored for clinical purposes. Combining comparative biology with a translational medicine approach, we report the development and application of a simple ex vivo frog (Xenopus tropicalis) skin organ culture system that permits exploration of the effects of amphibian skin-derived agents on re-epithelialisation in both frog and human skin. Using this amphibian model, we identify thyrotropin-releasing hormone (TRH) as a novel stimulant of epidermal regeneration. Moving to a complementary human ex vivo wounded skin assay, we demonstrate that the effects of TRH are conserved across the amphibian-mammalian divide: TRH stimulates wound closure and formation of neo-epidermis in organ-cultured human skin, accompanied by increased keratinocyte proliferation and wound healing-associated differentiation (cytokeratin 6 expression). Thus, TRH represents a novel, clinically relevant neuroendocrine wound repair promoter that deserves further exploration. These complementary frog and human skin ex vivo assays encourage a comparative biology approach in future wound healing research so as to facilitate the rapid identification and preclinical testing of novel, evolutionarily conserved, and clinically relevant wound healing promoters
The economics and politics of women's rights
Women’s rights and economic development are highly correlated. Today, the discrepancy between the legal rights of women and men is much larger in developing compared to developed countries. Historically, even in countries that are now rich women had few rights before economic development took off. Is development the cause of expanding women’s rights, or conversely, do women’s rights facilitate development? We argue that there is truth to both hypotheses. The literature on the economic consequences of women’s rights documents that more rights for women lead to more spending on health and children, which should benefit development. The politicaleconomy literature on the evolution of women’s rights finds that technological change increased the costs of patriarchy for men, and thus contributed to expanding women’s rights. Combining these perspectives, we discuss the theory of Doepke and Tertilt (2009), where an increase in the return to human capital induces men to vote for women’s rights, which in turn promotes growth in human capital and income per capita
Citizen science’s transformative impact on science, citizen empowerment and socio-political processes
Citizen science (CS) can foster transformative impact for science, citizen empowerment and socio-political processes. To unleash this impact, a clearer understanding of its current status and challenges for its development is needed. Using quantitative indicators developed in a collaborative stakeholder process, our study provides a comprehensive overview of the current status of CS in Germany, Austria and Switzerland. Our online survey with 340 responses focused on CS impact through (1) scientific practices, (2) participant learning and empowerment, and (3) socio-political processes. With regard to scientific impact, we found that data quality control is an established component of CS practice, while publication of CS data and results has not yet been achieved by all project coordinators (55%). Key benefits for citizen scientists were the experience of collective impact (“making a difference together with others”) as well as gaining new knowledge. For the citizen scientists’ learning outcomes, different forms of social learning, such as systematic feedback or personal mentoring, were essential. While the majority of respondents attributed an important value to CS for decision-making, only few were confident that CS data were indeed utilized as evidence by decision-makers. Based on these results, we recommend (1) that project coordinators and researchers strengthen scientific impact by fostering data management and publications, (2) that project coordinators and citizen scientists enhance participant impact by promoting social learning opportunities and (3) that project initiators and CS networks foster socio-political impact through early engagement with decision-makers and alignment with ongoing policy processes. In this way, CS can evolve its transformative impact
Mutations in KEOPS-Complex Genes Cause Nephrotic Syndrome with Primary Microcephaly
Galloway-Mowat syndrome (GAMOS) is an autosomal-recessive disease characterized by the combination of early-onset nephrotic syndrome (SRNS) and microcephaly with brain anomalies. Here we identified recessive mutations in OSGEP, TP53RK, TPRKB, and LAGE3, genes encoding the four subunits of the KEOPS complex, in 37 individuals from 32 families with GAMOS. CRISPR-Cas9 knockout in zebrafish and mice recapitulated the human phenotype of primary microcephaly and resulted in early lethality. Knockdown of OSGEP, TP53RK, or TPRKB inhibited cell proliferation, which human mutations did not rescue. Furthermore, knockdown of these genes impaired protein translation, caused endoplasmic reticulum stress, activated DNA-damage-response signaling, and ultimately induced apoptosis. Knockdown of OSGEP or TP53RK induced defects in the actin cytoskeleton and decreased the migration rate of human podocytes, an established intermediate phenotype of SRNS. We thus identified four new monogenic causes of GAMOS, describe a link between KEOPS function and human disease, and delineate potential pathogenic mechanisms
A pandemic recap : lessons we have learned
On January 2020, the WHO Director General declared that the outbreak constitutes a Public Health Emergency of International Concern. The world has faced a worldwide spread crisis and is still dealing with it. The present paper represents a white paper concerning the tough lessons we have learned from the COVID-19 pandemic. Thus, an international and heterogenous multidisciplinary panel of very differentiated people would like to share global experiences and lessons with all interested and especially those responsible for future healthcare decision making. With the present paper, international and heterogenous multidisciplinary panel of very differentiated people would like to share global experiences and lessons with all interested and especially those responsible for future healthcare decision making.Non peer reviewe
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