General relationship between strength and hardness Zhang, P.; Li, S.X.; Zhang, Z.F.
Materials science & engineering. A, Structural materials : properties, microstructure and processing,
11/2011, Letnik:
529
Journal Article
Recenzirano
► The hardness is not an intrinsic property but reflects the hardening state in CG. ► The ratio of hardness to strength can also be reflected by indentation morphology. ► The ratio of hardness to ...strength increases with increasing parameter
α. ►
H
V
=
3
σ
UTS
is valid for materials with relatively high strength and better toughness.
Both hardness and strength are the important properties of materials, and they often obey the three times empirical relationship in work-hardened metals and some bulk metallic glasses (BMGs). But the relationships between strength and hardness are quite different for those coarse-grained (CG) and ultrafine-grained materials, brittle BMGs and ceramics. In the present work, some Cu alloys with different microstructures, Zr-, Co-based BMGs and Al
2O
3 were employed to analyze the general relationship between hardness and strength. Several different relationships could be gotten from the experimental results of different materials available, and three types of indentation morphologies were observed. Indentation with “sink-in” morphology always represents a state of material and one third of hardness is in the range from yield strength to ultimate tensile strength. The other two indentation morphologies induced the fully hardening of material, so hardness could represent the intrinsic mechanical property of materials. The ratios of hardness to strength are found to be affected by the piled-up behaviors and their ability of shear deformation. Combined effect of the two aspects makes hardness approximately be three times of strength in the work-hardened crystalline materials and the shearable BMGs, but higher than three times of strength in the brittle-, annealed BMGs and ceramics.
Current status of viroid taxonomy Di Serio, F; Flores, R; Verhoeven, J. Th. J ...
Archives of virology,
12/2014, Letnik:
159, Številka:
12
Journal Article
Recenzirano
Odprti dostop
Viroids are the smallest autonomous infectious nucleic acids known so far. With a small circular RNA genome of about 250-400 nt, which apparently does not code for any protein, viroids replicate and ...move systemically in host plants. Since the discovery of the first viroid almost forty-five years ago, many different viroids have been isolated, characterized and, frequently, identified as the causal agents of plant diseases. The first viroid classification scheme was proposed in the early 1990s and adopted by the International Committee on Taxonomy of Viruses (ICTV) a few years later. Here, the current viroid taxonomy scheme and the criteria for viroid species demarcation are discussed, highlighting the main taxonomic questions currently under consideration by the ICTV Viroid Study Group. The impact of correct taxonomic annotation of viroid sequence variants is also addressed, taking into consideration the increasing application of next-generation sequencing and bioinformatics for known and previously unrecognized viroids.
Organoids have extensive therapeutic potential and are increasingly opening up new avenues within regenerative medicine. However, their clinical application is greatly limited by the lack of ...effective GMP-compliant systems for organoid expansion in culture. Here, we envisage that the use of extracellular matrix (ECM) hydrogels derived from decellularized tissues (DT) can provide an environment capable of directing cell growth. These gels possess the biochemical signature of tissue-specific ECM and have the potential for clinical translation. Gels from decellularized porcine small intestine (SI) mucosa/submucosa enable formation and growth of endoderm-derived human organoids, such as gastric, hepatic, pancreatic, and SI. ECM gels can be used as a tool for direct human organoid derivation, for cell growth with a stable transcriptomic signature, and for in vivo organoid delivery. The development of these ECM-derived hydrogels opens up the potential for human organoids to be used clinically.
We present lattice QCD results for masses and magnetic polarizabilities of light and strange pseudoscalar mesons, chiral condensates, decay constants of neutral pion, and neutral kaon in the presence ...of background magnetic fields with e B ranging up to around 3.35 GeV2( ~ 70 M2π) in the vacuum. The computations were carried out in (2 + 1)-flavor QCD mostly on 323 × 96 lattices using the highly improved staggered quark action with Mπ ≈ 220 MeV at zero temperature. We find that the masses of neutral pseudoscalar mesons monotonously decrease as the magnetic field strength grows and then saturate at a nonzero value, while there exists a nonmonotonous behavior of charged pion and kaon masses in the magnetic field. We observe a qB scaling of the up and down quark flavor components of neutral pion mass, neutral pion decay constant as well as the quark chiral condensates at 0.05 ≲ eB ≲ 3.35 GeV2. We show that the correction to the Gell-Mann-Oakes-Renner relation involving the neutral pion is less than 6% and the correction for the relation involving neutral kaon is less than 30% at e B ≲ 3.35 GeV2 . We also derive the Ward-Takahashi identities for QCD in the magnetic field in the continuum formulation including the relation between integrated neutral pseudoscalar meson correlators and chiral condensates.
Purpose
To explore the effects of mobile health (mHealth) intervention on pregnancy weight management, blood glucose control and pregnancy outcomes.
Methods
A total of 124 patients with gestational ...diabetes mellitus (GDM) were selected. Patients were randomly divided into two groups. The 60 patients in the control group received standard outpatient treatment, while the remaining 64 patients received a nurse’s online guidance both through a mobile medical App installed on their phone and through regular offline clinical treatment in the mHealth group. Patients were treated for an average of 13 weeks and general conditions, compliance, blood glucose, glycosylated hemoglobin, weight gain, pregnancy, and neonatal outcomes were monitored in both groups longitudinally.
Results
The mHealth group demonstrated higher levels of compliance (83.3 ± 12.5% vs. 70.4 ± 10.1%,
t
= − 6.293,
df
= 122,
p
< 0.001), lower frequency of outpatient service (8.1 ± 1.3 vs. 11.2 ± 1.1,
t
= 14.285,
df
= 122,
p
< 0.001), lower hemoglobin A1C before delivery (4.7 ± 0.2 vs. 5.3 ± 0.3,
t
= 13.216,
df
= 122,
p
< 0.001) as well as the rates of off-target measurements both fasting (4.6 ± 0.4% vs. 8.3 ± 0.6%,
t
= 40.659,
df
= 122,
p
< 0.001) and 2 h post-prandial (7.9 ± 0.7% vs. 14.7 ± 0.8%,
t
= 50.746,
df
= 122,
p
< 0.001). Weight gain in the mHealth group was less than control group (3.2 ± 0.8 vs. 4.8 ± 0.7,
t
= 11.851,
df
= 122
p
< 0.001).
Conclusion
Mobile health intervention management of gestational diabetes mellitus improves patients’ compliance and blood glucose control, and reduces weight gain, thereby reducing the rates of complications in both pregnant women and fetuses during delivery during pregnancy.
To analysis the clinical characteristics of 400 fetuses with heart defects and the impactors of pregnancy decision making, and explore the influence of a multi-disciplinary team (MDT) cooperation ...approach on it.
Clinical data of 400 fetuses with abnormal cardiac structure diagnosed at Peking University First Hospital from January 2012 to June 2021 were collected, which were divided into 4 groups according to the characteristics of fetal heart defects and the presence of extracardiac abnormalities or not: single cardiac defects without extracardiac abnormalities (122 cases), multiple cardiac defects without extracardiac abnormalities (100 cases), single cardiac defects with extracardiac abnormalities (115 cases), and multiple cardiac defects with extracardiac abnormalities (63 cases). The types of fetal cardiac structural abnormalities and genetic test results, and the detection rate of pathogenic genetic abnormalities, MDT consultation and management situation, and pregnancy decision of fetuses in each group
Superconductivity arises from two distinct quantum phenomena: electron pairing and long-range phase coherence. In conventional superconductors, the two quantum phenomena generally take place ...simultaneously, while in the underdoped high- Tc cuprate superconductors, the electron pairing occurs at higher temperature than the long-range phase coherence. Recently, whether electron pairing is also prior to long-range phase coherence in single-layer FeSe film on SrTiO3 substrate is under debate. Here, by measuring Knight shift and nuclear spin-lattice relaxation rate, we unambiguously reveal a pseudogap behavior below Tp∼60 K in two kinds of layered FeSe-based superconductors with quasi2D nature. In the pseudogap regime, a weak diamagnetic signal and a remarkable Nernst effect are also observed, which indicates that the observed pseudogap behavior is related to superconducting fluctuations. These works confirm that strong phase fluctuation is an important character in the 2D iron-based superconductors as widely observed in high-Tc cuprate superconductors.
Scalar atomic magnetometers have many attractive features but their sensitivity has been relatively poor. We describe a Rb scalar gradiometer using two multipass optical cells. We use a pump-probe ...measurement scheme to suppress spin-exchange relaxation and two probe pulses to find the spin precession zero crossing times with a resolution of 1 psec. We realize a magnetic field sensitivity of 0.54 fT/Hz(1/2), which improves by an order of magnitude the best scalar magnetometer sensitivity and exceeds, for example, the quantum limit set by the spin-exchange collisions for a scalar magnetometer with the same measurement volume operating in a continuous regime.
Purpose
The function of B cells in papillary thyroid cancer (PTC) is controversial. The role of B-cell-related tertiary lymphoid structures (TLSs) is still unclear. Whether B cells exert their ...anti-tumor effect through forming TLS in PTC needs further investigation.
Methods
We detected the percentage of B cells in PTC tissues by multi-parameter flow cytometry. Paraffin-embedded tumor tissues of 125 PTC patients were collected and stained with Haematoxylin–Eosin (H&E) for inflammatory infiltration analysis in combination with clinical features. Multiplexed immunohistochemistry (mIHC) was performed to verify the TLSs in above inflammatory infiltration. Correlation of B cells and TLSs with prognosis was analyzed using the TCGA database.
Results
We observed that PTC patients with higher expression of B lineage cell genes had improved survival and the percentage of B cells in the PTC tumor tissues was variable. Moreover, PTC tumor tissues with more B cells were surrounded by immune cell aggregates of varying sizes. We furtherly confirmed the immune cell aggregates as TLSs with different maturation stages. By analyzing PTC data from TCGA database, we found the maturation stages of TLSs were associated with genders and clinical stages among PTC patients. Moreover, patients with high TLSs survived longer and had a better prognosis.
Conclusion
B cells are associated with the existence of TLSs which have different maturation stages in PTC. Both B cells and TLSs are associated with the survival rate of PTC. These observations indicate that the anti-tumor effects of B cells in PTC are associated with TLSs formation.
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