Dynamic fracture failure of rocks subjected to static hydrostatic pressure is commonly encountered in deep underground rock engineering. The static fracture behavior of rocks under hydrostatic stress ...has been well studied in the literature. However, it is desirable to investigate the dynamic fracture failure of rocks under various hydrostatic pressures. In this study, a triaxial split Hopkinson pressure bar (SHPB) system is used to measure the dynamic fracture toughness of rocks under five hydrostatic pressures. The results show that dynamic fracture toughness under a certain hydrostatic pressure enhances with the increase of the loading rate, and the dynamic fracture toughness at the similar loading rate increases with the hydrostatic pressure due to the closure of microcracks in rocks. An empirical formula is proposed to describe the influences of the loading rate and the hydrostatic pressure on the rock dynamic fracture toughness.
Rare-earth-doped crystals are excellent hardware for quantum storage of photons. Additional functionality of these materials is added by their waveguiding properties allowing for on-chip photonic ...networks. However, detection and coherent properties of rare-earth single-spin qubits have not been demonstrated so far. Here we present experimental results on high-fidelity optical initialization, efficient coherent manipulation and optical readout of a single-electron spin of Ce(3+) ion in a yttrium aluminium garnet crystal. Under dynamic decoupling, spin coherence lifetime reaches T2 = 2 ms and is almost limited by the measured spin-lattice relaxation time T1 = 4.5 ms. Strong hyperfine coupling to aluminium nuclear spins suggests that cerium electron spins can be exploited as an interface between photons and long-lived nuclear spin memory. Combined with high brightness of Ce(3+) emission and a possibility of creating photonic circuits out of the host material, this makes cerium spins an interesting option for integrated quantum photonics.
A study was conducted to investigate the inclusion effects of sugar beet pulp and rice straw mixture silage with inoculation (BRMS), in place of whole-plant corn silage (CS), on the dry matter ...intake, total-tract nutrient digestibility, plasma metabolites, rumen fermentation, and lactation performance in high-production dairy cows. Sixteen multiparous Holstein cows (body weight, 622 ± 35 kg; days in milk, 90 ± 11 d; mean ± standard deviation) were used in our experiments; the experiments were based on a repeated 4 × 4 Latin square design for 21 d, and each experimental period consisted of 14 d of adaptation, followed by 7 d of data collection. The 4 dietary treatments used were (dry matter basis): (1) 0% BRMS and 28.6% CS (0BRMS); (2) 4.3% BRMS and 24.3% CS (15BRMS); (3) 8.60% BRMS and 20.0% CS (30BRMS); and (4) 12.9% BRMS and 15.7% CS (45BRMS). The increasing inclusion of dietary BRMS was observed to linearly increase the total volatile fatty acids and the propionate concentration. The dry matter intake and digestibility values of neutral detergent fiber and acid detergent fiber increased linearly as the percentage of BRMS increased up to 45%. Milk yield linearly increased with the increase in the content of BRMS (39.0, 39.8, 40.9, and 40.3 kg/d for 0BRMS, 15BRMS, 30BRMS, and 45BRMS, respectively). The increasing inclusion of dietary BRMS induced a decrease in the ammonia nitrogen and milk urea nitrogen concentration, leading to a linear increase in milk protein production (1.15, 1.26, 1.35, and 1.27 kg/d for 0BRMS, 15BRMS, 30BRMS, and 45BRMS, respectively). In conclusion, the diets with the replacement of CS with BRMS up to 45% were beneficial to the production performance of high-production dairy cows, indicating that this method may be an appropriate use of sugar beet pulp and rice straw.
Owing to the diverse sample quality as a result of different synthesis methods, previous studies on p-type MCoSb (M = Zr, Hf, Ti)-based half-Heusler thermoelectric (TE) compounds yield inconsistent ...results. It is thus necessary to verify the optimized carrier concentration and understand the transport mechanisms for this system based on high-purity samples, which can provide the guidance of further improving its TE properties and reasonably assess the application potential. In this work, high-purity Zr0.5Hf0.5CoSb1-xSnx (x = 0.05–0.30) and Zr1-yHfyCoSb0.8Sn0.2 (y = 0–1.0) are synthesized to understand the intrinsic electrical and thermal transport features. The optimized carrier concentration is found to be about 2.2×1021 cm−3 with the Sn doping level x = 0.2. A high power factor more than 3×10−3 Wm−1K−2 at 800 K is achieved for Zr0.5Hf0.5CoSb0.8Sn0.2. Moreover, our results indicate that it is necessary to combine alloying at the M site and grain refinement to achieve a low lattice thermal conductivity. A relatively high zT ∼0.93 at 1123 K is obtained for the Zr0.5Hf0.5CoSb0.8Sn0.2 sample. This work provides useful insight into the charge carrier and phonon transport mechanisms and confirms the TE application potential of this system.
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•The origin of inconsistent results in thermoelectric MCoSb systems from previous studies is discussed.•The point defect scattering and grain boundary scattering are found to be important for phonon transport in the MCoSb system.•A high power factor more than 3 × 10−3 Wm−1K−2 at 800 K is achieved via optimizing the carrier concentration.•A peak zT ∼0.93 is achieved at 1123 K for the Zr0.5Hf0.5CoSb0.8Sn0.2 sample.
Evidence suggests that mitochondrial abnormalities increase the risk of two neurodevelopmental disorders: undiagnosed developmental disorder (UDD) and autism spectrum disorder (ASD). However, which ...nuclear-encoded mitochondrial-related genes (NEMGs) were associated with UDD-ASD is unclear.
To explore the association between de novo variants (DNVs) of NEMGs and UDD-ASD.
Comprehensive analysis based on DNVs of NEMGs identified in patients (31 058 UDD probands and 10 318 ASD probands) and 4262 controls.
By curating NEMGs and cataloging publicly published DNVs in NEMGs, we compared the frequency of DNVs in cases and controls. We also applied a TADA-denovo model to highlight disease-associated NEMGs and characterized them based on gene intolerance, functional networks and expression patterns.
Compared with levels in 4262 controls, an excess of protein-truncating variants and deleterious missense variants in 1421 cataloged NEMGs from 41 376 patients (31 058 UDD and 10 318 ASD probands) was observed. Overall, 3.23% of de novo deleterious missense variants and 3.20% of de novo protein-truncating variants contributed to 1.1% and 0.39% of UDD-ASD cases, respectively. We prioritized 130 disease-associated NEMGs and showed distinct expression patterns in the developing human brain. Disease-associated NEMGs expression was enriched in both excitatory and inhibitory neuronal lineages from the developing human cortex.
Rare genetic alterations of disease-associated NEMGs may play a role in UDD-ASD development and lay the groundwork for a better understanding of the biology of UDD-ASD.
Pure aluminium particles were successfully synthesised into fully dense bulk material by back pressure equal channel angular consolidation (BP-ECAC) at 100
°C. The as-consolidated material showed a ...fine grain structure with excellent tensile strength and ductility. The simplicity and effectiveness of BP-ECAC make it a promising process for producing strong bulk materials from particles.
To investigate the clinical significance of endothelin A receptor (ETAR) expression in high-grade serous ovarian carcinoma (HGSOC). To design ETAR carboxyl terminal (ETAR-C) amino acids derived ...polypeptide and to study the inhibitory effect on ovarian epithelial carcinoma cells in vitro.
(1) A total of 126 patients who received surgical treatment and were diagnosed with HGSOC by postoperative pathological examination in Central Hospital of Xuzhou from January 1, 2007 to December 31, 2017 were selected. All patients had completed clinicopathological data and follow-up data. Cancer tissue samples were collected and ETAR mRNA expression in HGSOC tissues was detected by reverse transcript-PCR. The clinical significance was analyzed. (2) ETAR-C fusion polypeptide was designed based on the sequence of carboxyl terminal amino acids of ETAR, expressed and purified in vitro. The effects of ETAR-C fusion polypeptide on migration and invasion ability of ovarian cancer SKOV3 and CAOV3 cells were detected by scratch test
The cracked chevron notch Brazilian disc (CCNBD) method is widely used in characterizing rock fracture toughness. We explore here the possibility of extending the CCNBD method to dynamic rock ...fracture testing. In dynamic rock fractures, relevant fracture parameters are the initiation fracture toughness, the fracture energy, the fracture propagation toughness, and the fracture velocity. The dynamic load is applied with a split Hopkinson pressure bar (SHPB) apparatus. A strain gauge is mounted on the sample surface near the notch tip to detect the fracture-induced strain release, and a laser gap gauge (LGG) is used to monitor the crack surface opening distance (CSOD) during the test. With dynamic force balance achieved in the tests, the stable–unstable transition of the crack propagation crack is observed and the initiation fracture toughness is obtained from the peak load. The dynamic fracture initiation toughness values obtained for the chosen rock (Laurentian granite) using this method are consistent with those measured using other methods. The dynamic fracture initiation toughness is in the range 2.5–4.6
MPa
m
1/2 and the propagation fracture toughness is in the range 7.1–10.6
MPa
m
1/2, which is consistently larger than the initiation toughness.
We propose and validate a fracture testing method using a notched core-based semi-circular bend (SCB) specimen loaded dynamically with a modified split Hopkinson pressure bar (SHPB) apparatus. An ...isotropic fine-grained granitic rock, Laurentian granite (LG) is tested to validate this dynamic SCB method. Strain gauges are mounted near the crack tip of the specimen to detect the fracture onset and a laser gap gauge (LGG) is employed to monitor the crack surface opening distance. We demonstrate that with dynamic force balance achieved by pulse shaping, the peak of the far-field load synchronizes with the specimen fracture time. Furthermore, the evolution of dynamic stress intensity factor (SIF) obtained from the dynamic finite element analysis agrees with that from quasi-static analysis. These results prove that with dynamic force balance in SHPB, the inertial effect is minimized even for samples with complex geometries like notched SCB disc. The dynamic force balance thus enables the regression of dynamic fracture toughness using quasi-static analysis. This dynamic SCB method provides an easy and cost-effective way to measure dynamic fracture toughness of rocks and other brittle materials.
Paroxysmal kinesigenic dyskinesias is a paroxysmal movement disorder characterized by recurrent, brief attacks of abnormal involuntary movements induced by sudden voluntary movements. Although ...several loci, including the pericentromeric region of chromosome 16, have been linked to paroxysmal kinesigenic dyskinesias, the causative gene has not yet been identified. Here, we identified proline-rich transmembrane protein 2 (PRRT2) as a causative gene of paroxysmal kinesigenic dyskinesias by using a combination of exome sequencing and linkage analysis. Genetic linkage mapping with 11 markers that encompassed the pericentromeric of chromosome 16 was performed in 27 members of two families with autosomal dominant paroxysmal kinesigenic dyskinesias. Then, the whole-exome sequencing was performed in three patients from these two families. By combining the defined linkage region (16p12.1-q12.1) and the results of exome sequencing, we identified an insertion mutation c.649_650InsC (p.P217fsX7) in one family and a nonsense mutation c.487C>T (p.Q163X) in another family. To confirm our findings, we sequenced the exons and flanking introns of PRRT2 in another three families with paroxysmal kinesigenic dyskinesias. The c.649_650InsC (p.P217fsX7) mutation was identified in two of these families, whereas a missense mutation, c.796C>T (R266W), was identified in another family with paroxysmal kinesigenic dyskinesias. All of these mutations completely co-segregated with the phenotype in each family. None of these mutations was identified in 500 normal unaffected individuals of matched geographical ancestry. Thus, we have identified PRRT2 as the first causative gene of paroxysmal kinesigenic dyskinesias, warranting further investigations to understand the pathogenesis of this disorder.
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