Ultra-high resistive switching current ratio and improved ferroelectricity and dielectric tunability performance in a BaTiO3/La0.7Sr0.3MnO3 heterostructure by inserting a SrCoO2.5 layer

A BaTiO3/SrCoO2.5 (BTO/SCO) bilayer and a BTO single film were prepared by radio frequency magnetron sputtering on La0.7Sr0.3MnO3 (LSMO) buffered SrTiO3 (001) substrates. Interestingly, compared with reported BTO-based films, the BTO/SCO/LSMO heterostructure has a maximum ON/OFF current ratio of ∼945. More interestingly, compared with the BTO single layer, a larger Pr (∼18.4 μC cm-2) and larger dielectric tunability (∼71.9%) were achieved in the BTO/SCO bilayer. The improved performance may be attributed to the large tetragonality and improved oxygen vacancy concentrations in the BTO/SCO/LSMO heterostructure. Furthermore, our BTO/SCO/LSMO stacks exhibit potential for flexible electronic informational devices.

[Surgical treatment for perihilar cholangiocarcinoma:a single-center experience]

Objective: To investigate surgical strategies and the corresponding benefits for patients with perihilar cholangiocarcinoma(pCCA). Methods: A total of 81 patients with pCCA who underwent radical excision in the Department of Biliary and Pancreatic Surgery of Sun Yat-Sen Memorial Hospital between January 2014 and December 2021 were retrospectively collected.The cohort consisted of 50 male and 31 female patients,with an age of (62.5±11.5)years(range:26 to 83 years).Seventy-five cases were diagnosed with jaundice,60 of whom received preoperative biliary drainage,while 20 patients received portal vein embolization.Their serum bilirubin level within one week before the operation(M(IQR)) was 44.3 (41.9) μmol/L(range:8.0 to 344.2 μmol/L).Preoperative imaging examinations were performed to evaluate the Bismuth-Corlette type of pCCA,showing 3,6,21,27,and 24 cases of Bismuth-Corlette type Ⅰ,Ⅱ,Ⅲa,Ⅲb,and Ⅳ,respectively.The primary outcome was overall survival (OS),and the secondary outcomes were relapse-free survival (RFS),90-day postoperative morbidity and 90-day postoperative mortality.OS and RFS were estimated using the Kaplan-Meier method and compared by the Log-rank test.Significant prognostic factors were determined using univariate and multivariable Cox proportional hazard regression analyses. Results: In the cohort of 81 pCCA patients,67 cases(82.7%) underwent major hepatectomy while 3 cases received major hepatectomy combined with pancreaticoduodenectomy.Thirty-four patients underwent hepatectomy combined with vascular resection and reconstruction(18 cases of portal vein resection and reconstruction alone;9 cases of hepatic artery resection and reconstruction alone;7 cases of combination of portal vein and hepatic artery resection and reconstruction).Margin negative(R0 excision) were achieved in 53.1%(43/81) of these patients.The operation duration was (627±136)minutes(range:565 to 940 minutes),and the intraoperative blood loss was 400(455)ml(range:200 to 2 800 ml).The 90-day postoperative mortality was 3.7%(3/81).Grade 3-4 postoperative morbidity was 23.4% (19/81) according to the Clavien-Dindo classification of surgical complications.Up to the last follow-up at September 2022,the follow-up time was 34.0(24.2)months (range:0.4 to 103.6 months).Three patients who died within 90 days after surgery were excluded from the survival analysis.The median OS was 36.10 months (95%CI:18.23 to 42.97 months) and the 1-,3-and 5-year OS rates were 85.3%,46.8% and 27.3%,respectively.The median OS of 41 patients with negative margins was 47.83 months(95%CI:36.90 to 58.80 months) and that of 37 patients with positive margins was 20.47 months(95%CI:10.52 to 30.58 months).The median RFS of 70 patients with R0 and R1 resection was 24.50 months(95%CI:12.15 to 31.85 months)and the 1-,3-and 5-year RFS rates were 65.2%,45.7% and 29.9%,respectively.The median RFS of 41 patients with R0 resection was 38.57 months(95%CI:21.50 to 55.63 months) and that of 29 patients with R1 resection was 10.83 months(95%CI:2.82 to 19.86 months). Conclusions: The primary therapy for pCCA is radical surgical resection.A precise preoperative evaluation and sufficient preparation can reduce postoperative morbidity.Surgical treatment can achieve a better survival outcome by increasing the radical resection rate.

[The clinical characteristic treatment strategy and prognosis of adenoid cystic carcinoma of the head and neck]

Objective: To explore the clinical characteristics, treatment strategy and prognosis of adenoid cystic carcinoma of the head and neck (ACCHN). Methods: A retrospective analysis of the clinical and follow-up treatment of 79 patients with ACCHN from June 2008 to July 2017 was conducted in the Cancer Hospital of Zhengzhou University. Results: A total of 79 ACCHN cases, including 31 males and 48 females. The age ranged from 19 to 77 (median, 52). The clinical manifestations of ACC were related to the locations of primary tumor.The mean size of the tumor was 2.6 cm (range from 1.5 to 7.7 cm). 50 of 79 patients with a definitive pathological diagnosis received surgical resection. 59 cases received chemotherapy and 62 cases received radiotherapy. With a median follow-up of 55 months, the 5-year, 10-year survival rate of these patients were 69.6% and 54.4%, respectively. Conclusions: ACCHN is an uncommon neoplasm with the characteristics of epithelial nerve growth, being inclined to distant metastasis, and high early misdiagnosis rate. The clinical manifestation, imaging and pathological result are need to be combined together to diagnose ACCHN.

[miRNA-96-5p inhibits the proliferation and migration of gastric cancer cells by targeting FoxQ1]

Objective: To investigate the role of microRNA-96-5p in the proliferation and invasion of gastric cancer cells and its molecular mechanism. Methods: From June 2015 to January 2017, 53 resected specimens were collected. The transcriptional levels of microRNA-96-5p and forkhead box Q1 (FoxQ1) in gastric cancer tissues and the matched para-cancerous tissues were quantified by quantitative real-time PCR (qRT-PCR). The expression of FoxQ1 protein was also detected by immunohistochemistry (IHC). The relationship between microRNA-96-5p expression and the clinicopathological features of gastric cancer and its correlation with FoxQ1 expression were analyzed. The expressions of miRNA-96-5p in gastric cancer tissue and adjacent normal tissue were detected by qRT-PCR. miRNA-96-5p mimics was transfected to BGC-823 gastric cancer cells. The effects of miRNA-96-5p on cell proliferation and invasion were detected by cell counting kit-8 (CCK-8) assay and Transwell assay, respectively. The protein expressions of FoxQ1, E-cadherin and vimentin were determined by western blot. The relationship between FoxQ1 and miRNA-96-5p expressed in BGC-823 cells was detected by dual-luciferase reporter assay. Results: The median expression of miRNA-96-5p in gastric cancer tissue was 1.05, significantly lower than 3.23 of para-cancerous tissues (P<0.05). The positive rate of FoxQ1 expression in gastric cancer tissue was 71.7%, significantly higher than 28.3% of para-cancerous tissues (P<0.05). The expression of FoxQ1 was negatively corelated with the level of miRNA-96-5p (r=-0.613, P=0.006). The expression of miRNA-96-5p in gastric cancer cell BGC-823 was significantly decreased compared with normal gastric epithelial cell (0.96±0.08 vs 2.84±0.15, P<0.05). The results of CCK-8 assay and Transwell assay showed that overexpression of miRNA-96-5p significantly reduced the proliferation and invasion abilities of gastric cancer cells (P<0.05). Overexpression of miRNA-96-5p decreased the protein level of FoxQ1. Moreover, it upregulated the expression of E-cadherin and downregulated the expression of vimentin. The result of dual-luciferase-3'-UTR reporter assay confirmed that miRNA-96-5p binds to the 3'UTR of FoxQ1. Conclusion: miRNA-96-5p may suppress the proliferation, migration and epithelial-mesenchymal transition (EMT) of gastric cancer cell by down-regulation of FoxQ1.

Topological valley pumping in Weyl semimetals

We investigate the topological pumping effect in Weyl semimetals, subject to the modulation of two ac electric fields along y  and z directions, respectively. We show that the pumping effect originates from the anomalous velocity related to the Berry curvature. The direction of the pumping current is dependent on the chirality of the Weyl fermions. While the total particle current is vanishing because the Weyl points of opposite chirality always come in pairs in Weyl semimetals, the pump gives rise to a net chirality current or valley current. The noiseless valley current generated can be useful in valleytronic applications.

[The clinical characteristics surgical procedures and prognosis of solid pseudopapillary tumor of the pancreas]

Objective: To explore the clinical characteristics, surgical procedures and prognosis of solid pseudopapillary tumor of the pancreas(SPTP). Methods: The clinical and follow-up data of 55 cases with SPTP in Henan Tumor Hospital from June 2005 to April 2015 were retrospectively analyzed. Results: There were 55 SPTP cases, including 7 males and 48 females. The age ranged from 16 to 76 (median, 33). Clinical presentations of SPTP were not specific. The mean size of the tumor was 7.6 cm (range from 2 to 25cm). Pancreatic head and tail were the most common locations of SPTP. All the patients received surgical resection with a definitive pathological diagnosis. Some immunohistochemical markers were mostly positive, including β-catenin, Vim, Syn, CD10, CD56, PR, etc. With a median follow-up of 53 months, the 1-year, 2-year and 5-year survival rate were 98.1%, 96.1% and 94.0%, respectively. Conclusions: SPTP is an uncommon exocrine pancreatic neoplasm with low malignant potential, which frequently occurs in young women. Preoperative imaging can provide evidence for the selection of treatment modalities among which surgical resection ispreferred. Diagnosis still relies on pathology and immunohistochemistry.

Analytical theory and possible detection of the ac quantum spin Hall effect

We develop an analytical theory of the low-frequency ac quantum spin Hall (QSH) effect based upon the scattering matrix formalism. It is shown that the ac QSH effect can be interpreted as a bulk quantum pumping effect. When the electron spin is conserved, the integer-quantized ac spin Hall conductivity can be linked to the winding numbers of the reflection matrices in the electrodes, which also equal to the bulk spin Chern numbers of the QSH material. Furthermore, a possible experimental scheme by using ferromagnetic metals as electrodes is proposed to detect the topological ac spin current by electrical means.

Theory of Inverse Edelstein Effect of The Surface States of A Topological Insulator

The surface states of three-dimensional topological insulators possess the unique property of spin-momentum interlocking. This property gives rise to the interesting inverse Edelstein effect (IEE), in which an applied spin bias μ is converted to a measurable charge voltage difference V. We develop a semiclassical theory for the IEE of the surface states of Bi2Se3 thin films, which is applicable from the ballistic regime to diffusive regime. We find that the efficiency of the spin-charge conversion, defined as γ = V/μ, exhibits a universal dependence on the ratio between sample size and electron mean free path. The efficiency increases from γ = π/4 in the ballistic limit to γ = π in the diffusive limit, suggesting that sufficient strength of impurity scattering is favorable for the IEE.

Experimental Observation of Anisotropic Adler-Bell-Jackiw Anomaly in Type-II Weyl Semimetal WTe_{1.98} Crystals at the Quasiclassical Regime

The asymmetric electron dispersion in type-II Weyl semimetal theoretically hosts anisotropic transport properties. Here, we observe the significant anisotropic Adler-Bell-Jackiw (ABJ) anomaly in the Fermi-level delicately adjusted WTe_{1.98} crystals. Quantitatively, C_{W}, a coefficient representing the intensity of the ABJ anomaly along the a and b axis of WTe_{1.98} are 0.030 and 0.051  T^{-2} at 2 K, respectively. We found that the temperature-sensitive ABJ anomaly is attributed to a topological phase transition from a type-II Weyl semimetal to a trivial semimetal, which is verified by a first-principles calculation using experimentally determined lattice parameters at different temperatures. Theoretical electrical transport study reveals that the observation of an anisotropic ABJ along both the a and b axes in WTe_{1.98} is attributed to electrical transport in the quasiclassical regime. Our work may suggest that electron-doped WTe_{2} is an ideal playground to explore the novel properties in type-II Weyl semimetals.

Time-reversal-breaking induced quantum spin Hall effect

We show that quantum spin Hall (QSH) effect does not occur in a square lattice model due to cancellation of the intrinsic spin-orbit coupling coming from different hopping paths. However, we show that QSH effect can be induced by the presence of staggered magnetic fluxes alternating directions square by square. When the resulting Peierls phase takes a special value , the system has a composite symmetry ΘΡ₋ with Θ the time-reversal operator and Ρ₋ transforming the Peierls phase from γ to γ − , which protects the gapless edge states. Once the phase deviates from , the edge states open a gap, as the composite symmetry is broken. We further investigate the effect of a Zeeman field on the QSH state, and find that the edge states remain gapless for . This indicates that the QSH effect is immune to the magnetic perturbation.

[Relationship between metastatic lymph node and prognosis of esophageal cancer patients treated with following radical esophagectomy]

Objective: To investigate the number of metastatic lymph nodes (pN) and the metastatic lymph node ratio (LNR) on the post-surgical prognosis of patients with esophageal cancer (EC). Methods: A retrospective analysis of 573 inpatients diagnosed as esophageal carcinomas from March 2008 to June 2012 was carried out.All pathologic specimen were reviewed by pathologists from Henan Tumor Hospital.The Kaplan-Meier method was used to calculate survival rates, and survival curves were compared with the Log-rank test.The Cox model was employed for multivariate analyses of factors.The association of pN and LNR with prognosis of esophageal cancer was examined by the area under the ROC curve(AUC). Results: The 1-, 3- and 5-year OS rates were 72.5%, 46.1% and 32.3%, respectively.Univariate analysis showed that tumor location(P=0.020), tumor length(P=0.009), pT stage(P=0.011), pN stage(P<0.01), and the LNR(P<0.01) were prognostic factors for OS.Multivariate analysis indicated that pT stage(P=0.047), pN stage(P=0.018) and LNR(P=0.011) were significant and independent risk factors for poor OS.ROC analysis indicated that LNR (AUC=0.680) had better predictive value than pN (AUC=0.579). Conclusion: The integrated use of LNR and pN may be suitable for evaluation of prognosis in patients with EC and positive nodal metastasis after curative resection.

π Spin Berry Phase in a Quantum-Spin-Hall-Insulator-Based Interferometer: Evidence for the Helical Spin Texture of the Edge States

The quantum spin Hall insulator is characterized by helical edge states, with the spin polarization of the electron being locked to its direction of motion. Although the edge-state conduction has been observed, unambiguous evidence of the helical spin texture is still lacking. Here, we investigate the coherent edge-state transport in an interference loop pinched by two point contacts. Because of the helical character, the forward interedge scattering enforces a π spin rotation. Two successive processes can only produce a nontrivial 2π or trivial 0 spin rotation, which can be controlled by the Rashba spin-orbit coupling. The nontrivial spin rotation results in a geometric π Berry phase, which can be detected by a π phase shift of the conductance oscillation relative to the trivial case. Our results provide smoking gun evidence for the helical spin texture of the edge states. Moreover, it also provides the opportunity to all electrically explore the trajectory-dependent spin Berry phase in condensed matter.

Zeeman-Field-Tuned Topological Phase Transitions in a Two-Dimensional Class-DIII Superconductor

We investigate the topological phase transitions in a two-dimensional time-reversal invariant topological superconductor in the presence of a Zeeman field. Based on the spin Chern number theory, we find that the system exhibits a number of topologically distinct phases with changing the out-of-plane component of the Zeeman field, including a quantum spin Hall-like phase, quantum anomalous Hall-like phases with total Chern number C = −2, −1, 1 and 2, and a topologically trivial superconductor phase. The BdG band gap closes at each boundary of the phase transitions. Furthermore, we demonstrate that the zero bias conductance provides clear transport signatures of the different topological phases, which are robust against symmetry-breaking perturbations.

SUSCEPTIBILITY LOCI FOR UMBILICAL HERNIA IN SWINE DETECTED BY GENOME-WIDE ASSOCIATION

Umbilical hernia (UH) is a complex disorder caused by both genetic and environmental factors. UH brings animal welfare problems and severe economic loss to the pig industry. Until now, the genetic basis of UH is poorly understood. The high-density 60K porcine SNP array enables the rapid application of genome-wide association study (GWAS) to identify genetic loci for phenotypic traits at genome wide scale in pigs. The objective of this research was to identify susceptibility loci for swine umbilical hernia using the GWAS approach. We genotyped 478 piglets from 142 families representing three Western commercial breeds with the Illumina PorcineSNP60 BeadChip. Then significant SNPs were detected by GWAS using ROADTRIPS (Robust Association-Detection Test for Related Individuals with Population Substructure) software base on a Bonferroni corrected threshold (P = 1.67E-06) or suggestive threshold (P = 3.34E-05) and false discovery rate (FDR = 0.05). After quality control, 29,924 qualified SNPs and 472 piglets were used for GWAS. Two suggestive loci predisposing to pig UH were identified at 44.25MB on SSC2 (rs81358018, P = 3.34E-06, FDR = 0.049933) and at 45.90MB on SSC17 (rs81479278, P = 3.30E-06, FDR = 0.049933) in Duroc population, respectively. And no SNP was detected to be associated with pig UH at significant level in neither Landrace nor Large White population. Furthermore, we carried out a meta-analysis in the combined pure-breed population containing all the 472 piglets. rs81479278 (P = 1.16E-06, FDR = 0.022475) was identified to associate with pig UH at genome-wide significant level. SRC was characterized as plausible candidate gene for susceptibility to pig UH according to its genomic position and biological functions. To our knowledge, this study gives the first description of GWAS identifying susceptibility loci for umbilical hernia in pigs. Our findings provide deeper insights to the genetic architecture of umbilical hernia in pigs.

The regulatory VirA protein of Agrobacterium tumefaciens does not function at elevated temperatures

Previous studies have shown that Agrobacterium tumefaciens causes tumors on plants only at temperatures below 32 degrees C, and virulence gene expression is specifically inhibited at temperatures above 32 degrees C. We show here that this effect persists even when the virA and virG loci are expressed under the control of a lac promoter whose activity is temperature independent. This finding suggests that one or more steps in the signal transduction process mediated by the VirA and VirG proteins are temperature sensitive. Both the autophosphorylation of VirA and the subsequent transfer of phosphate to VirG are shown to be sensitive to high temperatures (> 32 degrees C), and this correlates with the reduced vir gene expression observed at these temperatures. At temperatures of 32 degrees C and higher, the VirA molecule undergoes a reversible inactivation while the VirG molecule is not affected. vir gene induction is temperature sensitive in an acetosyringone-independent virA mutant background but not in a virG constitutive mutant which is virA and acetosyringone independent. These observations all support the notion that the VirA protein is responsible for the thermosensitivity of vir gene expression. However, an Agrobacterium strain containing a constitutive virG locus still cannot cause tumors on Kalanchoe plants at 32 degrees C. This strain induces normal-size tumors at temperatures up to 30 degrees C, whereas the wild-type Agrobacterium strain produces almost no tumors at 30 degrees C. These results suggest that at temperatures above 32 degrees C, the plant becomes more resistant to infection by A. tumefaciens and/or functions of some other vir gene products are lost in spite of their normal levels of expression.