Materials exhibiting a spontaneous electrical polarization that can be switched easily between antiparallel orientations are of potential value for sensors, photonics and energy-efficient memories. ...In this context, organic ferroelectrics are of particular interest because they promise to be lightweight, inexpensive and easily processed into devices. A recently identified family of organic ferroelectric structures is based on intermolecular charge transfer, where donor and acceptor molecules co-crystallize in an alternating fashion known as a mixed stack: in the crystalline lattice, a collective transfer of electrons from donor to acceptor molecules results in the formation of dipoles that can be realigned by an external field as molecules switch partners in the mixed stack. Although mixed stacks have been investigated extensively, only three systems are known to show ferroelectric switching, all below 71 kelvin. Here we describe supramolecular charge-transfer networks that undergo ferroelectric polarization switching with a ferroelectric Curie temperature above room temperature. These polar and switchable systems utilize a structural synergy between a hydrogen-bonded network and charge-transfer complexation of donor and acceptor molecules in a mixed stack. This supramolecular motif could help guide the development of other functional organic systems that can switch polarization under the influence of electric fields at ambient temperatures.
Epitheliotropic intestinal T-cell lymphoma (EITL, also known as type II enteropathy-associated T-cell lymphoma) is an aggressive intestinal disease with poor prognosis and its molecular alterations ...have not been comprehensively characterized. We aimed to identify actionable easy-to-screen alterations that would allow better diagnostics and/or treatment of this deadly disease. By performing whole-exome sequencing of four EITL tumor-normal pairs, followed by amplicon deep sequencing of 42 tumor samples, frequent alterations of the JAK-STAT and G-protein-coupled receptor (GPCR) signaling pathways were discovered in a large portion of samples. Specifically, STAT5B was mutated in a remarkable 63% of cases, JAK3 in 35% and GNAI2 in 24%, with the majority occurring at known activating hotspots in key functional domains. Moreover, STAT5B locus carried copy-neutral loss of heterozygosity resulting in the duplication of the mutant copy, suggesting the importance of mutant STAT5B dosage for the development of EITL. Dysregulation of the JAK-STAT and GPCR pathways was also supported by gene expression profiling and further verified in patient tumor samples. In vitro overexpression of GNAI2 mutants led to the upregulation of pERK1/2, a member of MEK-ERK pathway. Notably, inhibitors of both JAK-STAT and MEK-ERK pathways effectively reduced viability of patient-derived primary EITL cells, indicating potential therapeutic strategies for this neoplasm with no effective treatment currently available.
The dissimilar metal joint of titanium (Ti) to 304L stainless steel (SS) is essential in the nuclear industry for the dissolution of spent fuel that is carried out in boiling nitric acid in the ...dissolver vessel (made of Ti) and the dissolved solution is transported through the 304L SS pipes to the other plant components made of 304L SS. Because of the radioactive environment, leak tightness and corrosion resistance of this dissimilar joint are important. In this work, friction welding process was attempted to join Ti to 304L SS. Direct friction welding of Ti to 304L SS results in a stronger weld in which failure occurs in the Ti base metal during tensile testing. However, the joints have almost zero bend ductility that has been attributed to the formation of intermetallics due to mechanical alloying, strain hardening of Ti near the joint interface and residual stresses. Post-weld heat treatment marginally increases the bend ductility to 5° because of relieving of the effects of strain hardening and of residual stresses at the joint interface. Corrosion test in boiling nitric acid as per ASTM A-262 Practice C shows that the average corrosion rate is 10
mpy with the joints remaining intact after the corrosion test. The details of mechanical tests, microstructure analysis using optical and scanning electron microscopy, are discussed.
B-flavor tagging at Belle II Akopov, N.; Banerjee, Sw; Bauer, M. ...
The European physical journal. C, Particles and fields,
04/2022, Letnik:
82, Številka:
4
Journal Article
Recenzirano
Odprti dostop
We report on new flavor tagging algorithms developed to determine the quark-flavor content of bottom (
) mesons at Belle II. The algorithms provide essential inputs for measurements of quark-flavor ...mixing and charge-parity violation. We validate and evaluate the performance of the algorithms using hadronic
decays with flavor-specific final states reconstructed in a data set corresponding to an integrated luminosity of 62.8 fb
-
1
, collected at the
resonance with the Belle II detector at the SuperKEKB collider. We measure the total effective tagging efficiency to be
ε
eff
=
(
30.0
±
1.2
(
stat
)
±
0.4
(
syst
)
)
%
for a category-based algorithm and
ε
eff
=
(
28.8
±
1.2
(
stat
)
±
0.4
(
syst
)
)
%
for a deep-learning-based algorithm.
Microstructural features and creep-rupture behaviour of a dissimilar weld joint (DWJ) between Grade 91 (G91) steel and 316LN stainless steel prepared by Electron beam (EB) welding are investigated. ...The SEM-EDAX and EBSD observations in the fusion zone revealed compositional variations and distinct microstructural features, depending on the extent of mixing of both base metals. Further, at the interface between the fusion zone and G91 steel, nickel enrichment was observed, which lowered the Ac
1
temperature, resulting in fresh martensite and higher hardness upon PWHT. In the creep-rupture tests conducted at 873 K and 110 to 175 MPa, failure location shifted from G91 base metal to intercritical HAZ of G91 steel above 2500 hours of creep exposure. As against the interface failures, which are considered the life-limiting factor in DWJs, the ruptured specimens in the present study revealed better interface stability with insignificant cavitation even after creep exposure of over 10,000 hours. The composition at the ferritic–weld interface exhibits almost equivalent carbon activity to G91 steel which improved the interface stability by resisting the coarsening of carbides. It is important to highlight that the EB weld joint exhibited higher rupture life and weld strength reduction factor than the joints made by conventional multi-pass arc welding.
Summary
Growth in early life may predict adult bone health. Our data showed that greater height and body mass index (BMI) gain in utero and infancy are associated with higher peak bone mass, and ...greater BMI gain in childhood/adolescence with higher peak bone density. These associations are mediated by attained adult height and BMI.
Introduction
To study the relationship of height and BMI during childhood with adult bone mineral content (BMC), areal density (aBMD) and apparent density (BMAD, estimated volumetric density).
Methods
Participants comprised 565 men and women aged 33–39 years from the New Delhi Birth Cohort, India, whose weight and height were recorded at birth and annually during infancy (0–2 years), childhood (2–11 years) and adolescence (11 years–adult). Lumbar spine, femoral neck and forearm BMC and aBMD were measured using dual X-ray absorptiometry; lumbar spine and femoral neck BMAD were calculated.
Results
Birth length, and height and height gain during infancy, childhood and adolescence were positively correlated with adult BMC (
p
≤0.01 all sites except birth length with femoral neck). Correlations increased with height from birth to 6 years, then remained constant for later height measurements. There were no associations with BMAD. BMI at birth, and during childhood and adolescence was also positively correlated with BMC (
p
< 0.01 all sites). BMI at 11 years, and BMI gain in childhood and adolescence, were correlated with aBMD and BMAD (
p
< 0.001 for all); these correlations strengthened with increasing age of BMI measurement. The associations with height and BMI in early life became non-significant after adjustment for adult height and BMI.
Conclusions
Greater skeletal growth and BMI gain in utero and during infancy are associated with higher peak BMC, and greater BMI gain in childhood and adolescence is associated with higher peak aBMD and BMAD. These associations are mediated by the attainment of adult height and BMI, respectively.
To assess whether serial measurements of childhood body mass index (BMI) give clinically useful predictions of the risk of developing adult metabolic syndrome and impaired glucose tolerance or type 2 ...diabetes.
Follow-up of a community-based birth cohort in Delhi, India.
1492 men and women aged 26-32 years whose BMI was recorded 6-monthly throughout childhood.
The predictive value of childhood BMI for adult metabolic syndrome and impaired glucose tolerance (IGT) and diabetes mellitus.
25% of subjects had metabolic syndrome and 15% had IGT/diabetes mellitus. Both outcomes were associated with greater childhood BMI gain (metabolic syndrome: OR 1.63 (95% CI 1.44 to 1.85); IGT/diabetes mellitus: 1.39 (1.20 to 1.60) per unit increase in within-cohort BMI SD score between 5 and 14 years). The best predictions of adult disease were obtained using a combined test comprising (i) any increase in BMI SD score between 5 and 14 years and (ii) a BMI SD score >0 at 14 years (metabolic syndrome: sensitivity 45%, specificity 78%; IGT/diabetes mellitus: 37%, 73%). Likelihood ratios were low (metabolic syndrome: 1.4-2.0; IGT/diabetes mellitus: 1.2-1.4). A single high BMI measurement at 14 years (overweight or obese, according to International Obesity Task Force criteria) was highly specific but insensitive (metabolic syndrome: sensitivity 7%, specificity 97%; IGT/diabetes mellitus: 8%, 97%). Charts for plotting BMI SD scores through childhood were produced.
Serial measurements of childhood BMI give useful predictions of adult risk and could guide advice to children and parents on preventing later disease.
The Physics of the B Factories Golob, Bostjan; Mannel, Thomas; Bevan, Adrian
The European physical journal. C, Particles and fields,
11/2014, Letnik:
74, Številka:
11
eBook, Journal Article
Retinoic acid (RA; all-trans RA and 9-cis RA) enhances embryo developmental competence and quality through multiple mechanisms affecting the oocyte and preimplantation embryo. Folliculogenesis and ...oocyte maturation are influenced by tumor necrosis factor-α (TNF-α) via inhibition of aromatase activity and estradiol secretion in granulosa cells. Retinoic acid inhibits TNF-α production in various cell lines. The aim of the present study was to determine whether oocyte TNF-α concentrations regulate developmental competence and embryo quality and if the beneficial effects of 9-cis RA are mediated through attenuation of oocyte TNF-α production. Bovine cumulus oocyte complexes collected from abattoir ovaries were matured in maturation medium in the absence (control) or presence of 5 nM 9-cis RA (RA), 100 ng/mL of recombinant bovine TNF-α (TNF), or 5 nM 9-cis RA + 100 ng/mL of recombinant bovine TNF-α (RA+TNF). Oocytes were subsequently collected for gene expression analysis or subjected to in vitro fertilization and culture. Apoptosis and gene expression were analyzed in d-8 blastocysts. Results indicated that 9-cis RA downregulated (P < 0.01) both basal and TNF-α-induced TNF-α mRNA in oocytes (1.0-fold in control, 0.4-fold in RA, 2.1-fold in TNF, and 0.7-fold in RA+TNF). The 9-cis RA increased (P < 0.001) blastocyst development rates (37.1 ± 6.9 vs. 23.6 ± 8.0%) and total cell number (138.4 ± 19.2 vs. 120.2 ± 24.5) and reduced (P < 0.001) the percentage of apoptotic cells (3.3 ± 2.0 vs. 5.6 ± 2.3%) compared with controls. Expression of caspase 3 (0.4- vs. 1.0-fold) and TNF-α (0.4- vs. 1.0-fold) mRNA was downregulated (P < 0.05) in RA-treated blastocysts compared with controls. Moreover, 9-cis RA rescued (P < 0.001) development rates (24.5 ± 11.1 vs. 15.6 ± 9.0%), increased total cell number (124.6 ± 36.5 vs. 106.9 ± 31.1), and reduced apoptosis (5.8 ± 2.0 vs. 8.1 ± 3.1%) in blastocysts exposed to TNF-α (TNF group). Caspase 3 (0.8-fold in RA+TNF vs. 2.2-fold in TNF) and TNF-α (0.3-fold in RA+TNF vs. 2.8-fold in TNF) mRNA expression was attenuated (P < 0.05) in TNF-α-treated blastocysts. In conclusion, the present study suggests that 9-cis RA exerts its beneficial roles on oocyte developmental competence and embryo quality by attenuating oocyte TNF-α mRNA expression.
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