Enhanced ferromagnetism, perpendicular magnetic anisotropy and high Curie temperature in the van der Waals semiconductor CrSeBr through strain and doping.

Two-dimensional (2D) intrinsic van der Waals ferromagnetic semiconductor (FMS) crystals with strong perpendicular magnetic anisotropy and high Curie temperature (TC) are highly desirable and hold great promise for applications in ultrahigh-speed spintronic devices. Here, we systematically investigated the effects of a biaxial strain ranging between -8% and +8% and doping with different charge carrier concentrations (≤0.7 electrons/holes per unit cell) on the electronic structure, magnetic properties, and TC of monolayer CrSeBr by combining first-principles calculations and Monte Carlo (MC) simulations. Our results demonstrate that the pristine CrSeBr monolayer possesses an intrinsic FMS character with a band gap as large as 1.03 eV, an in-plane magnetic anisotropy of 0.131 meV per unit cell, and a TC as high as 164 K. At a biaxial strain of only 0.8% and a hole density of 5.31 × 1013 cm-2, the easy magnetization axis direction transitions from in-plane to out-of-plane. More interestingly, the magnetic anisotropy energy and TC of monolayer CrSeBr are further enhanced to 1.882 meV per unit cell and 279 K, respectively, under application of a tensile biaxial strain of 8%, and the monolayer retains its semiconducting properties throughout the entire range of investigated strains. It was also found that upon doping monolayer CrSeBr with holes with a concentration of 0.7 holes per unit cell, the perpendicular magnetic anisotropy and TC are increased to 0.756 meV per cell and 235 K, respectively, and the system tends to become metallic. These findings will help to advance the application of 2D intrinsic ferromagnetic materials in spintronic devices.

Strain Engineering and Halogen Compensation of Buried Interface in Polycrystalline Halide Perovskites.

Inverted perovskite solar cells based on weakly polarized hole-transporting layers suffer from the problem of polarity mismatch with the perovskite precursor solution, resulting in a nonideal wetting surface. In addition to the bottom-up growth of the polycrystalline halide perovskite, this will inevitably worse the effects of residual strain and heterogeneity at the buried interface on the interfacial carrier transport and localized compositional deficiency. Here, we propose a multifunctional hybrid pre-embedding strategy to improve substrate wettability and address unfavorable strain and heterogeneities. By exposing the buried interface, it was found that the residual strain of the perovskite films was markedly reduced because of the presence of organic polyelectrolyte and imidazolium salt, which not only realized the halogen compensation and the coordination of Pb2+ but also the buried interface morphology and defect recombination that were well regulated. Benefitting from the above advantages, the power conversion efficiency of the targeted inverted devices with a bandgap of 1.62 eV was 21.93% and outstanding intrinsic stability. In addition, this coembedding strategy can be extended to devices with a bandgap of 1.55 eV, and the champion device achieved a power conversion efficiency of 23.74%. In addition, the optimized perovskite solar cells retained 91% of their initial efficiency (960 h) when exposed to an ambient relative humidity of 20%, with a T80 of 680 h under heating aging at 65 °C, exhibiting elevated durability.

Hole-Doping-Induced Perpendicular Magnetic Anisotropy and High Curie Temperature in a CrSX (X = Cl, Br, I) Semiconductor Monolayer.

A large perpendicular magnetic anisotropy and a high Curie temperature (TC) are crucial for the application of two-dimensional (2D) intrinsic ferromagnets to spintronic devices. Here, we investigated the electronic and magnetic properties of carrier-doped Van der Waals layered CrSX (X = Cl, Br, I) ferromagnets using first-principles calculations. It was found that hole doping can increase the magnitude of the magnetic anisotropy energy (MAE) and change the orientation of the easy magnetization axis at small doping amounts of 2.37 × 1013, 3.98 × 1012, and 3.33 × 1012/cm2 for CrSCl, CrSBr, and CrSI monolayers, respectively. The maximum values of the MAE reach 57, 133, and 1597 µeV/u.c. for the critical hole-doped CrSCl, CrSBr, and CrSI with spin orientation along the (001) direction, respectively. Furthermore, the Fermi energy level of lightly hole-doped CrSX (X = Cl, Br, I) moves into the spin-up valence band, leading to the CrSX (X = Cl, Br, I) magnetic semiconductor monolayer becoming first a half-metal and then a metal. In addition, the TC can also be increased up to 305, 317, and 345 K for CrSCl, CrSBr, and CrSI monolayers at doping amounts of 5.94 × 1014, 5.78 × 1014, and 5.55 × 1014/cm2, respectively. These properties suggest that the hole-doping process can render 2D CrSX (X = Cl, Br, I) monolayers remarkable materials for application to electrically controlled spintronic devices.

Strain-tunable electric structure and magnetic anisotropy in monolayer CrSI.

Two-dimensional (2D) ferromagnetic semiconductors provide platforms for studying novel physical phenomena in low dimensional materials. Using first-principles calculations, we systematically investigate the effect of strain on the electronic structure and magnetic anisotropy energy (MAE) of monolayer CrSI. The results demonstrate that the easy axis of unstrained monolayer CrSI is parallel to the in-plane [100] axis and the MAE of monolayer CrSI is mainly contributed by the spin-polarized p-orbitals of nonmetallic I atoms. Remarkably, the strain transforms the ground state of monolayer CrSI from a ferromagnetic semiconductor to ferromagnetic metal. More importantly, the external strain can switch the direction of the easy axis of monolayer CrSI and compressive strain significantly enhances the MAE of the I atom to reach 0.52 meV per atom, which is comparable to that of metallic Fe atoms at Fe/MgO interfaces. Furthermore, we elucidate that the increase of the positive contributions of matrix element differences between the spin-up px and py orbitals as well as spin-up py and pz orbitals of the I atom to MAE with respect to compressive strain is the main cause of the significant enhancement in perpendicular magnetic anisotropy of monolayer CrSI under -10% compressive strain. Our research proves that monolayer CrSI has a good application prospect in magnetic storage devices.

Clinical performance of α-L-fucosidase for early detection of hepatocellular carcinoma.

Aim: To evaluate the diagnostic performance of serum AFU for early stage hepatocellular carcinoma (HCC). Methods: Concentration of AFU and AFP were measured in 512 patients. The performance was compared for AFU and AFP alone or in combination. Results: The area under the curve (AUC) for AFU was 0.68, with a sensitivity of 56.1% and specificity of 69.2% at the cut-off value of 24 U/l; whereas the AUC for AFP was 0.83, with a sensitivity of 58.2% and specificity of 85.2% at cut-off value of 20 ng/ml. The AUC of AFU alone or the combination with AFP were lower than that of AFP alone. Conclusion: AFU is a suboptimal biomarker for early detection of HCC.

Antinuclear antibodies detection: A comparative study between automated recognition and conventional visual interpretation.

BACKGROUND: The indirect immunofluorescence assay (IIFA) for the detection of antinuclear antibodies (ANA) was firstly described in 1958 and is still considered the reference method for ANA screening. Currently, an automated processing and recognition system for standardized and efficient ANA interpretation by human epithelial (HEp-2) cell-based immunofluorescence (IIF; EUROPattern Suite, Euroimmun) is available in China. METHODS: In this study, the performance of this novel system for positive/negative classification, pattern recognition (including homogenous, speckled, nucleolar, nuclear dots, cytoplasmic, and centromeres patterns) and titers evaluation was evaluated by comparing to visual interpretation. RESULTS: Referring to the total of 3681 collected samples, there was an agreement of 98.7% (κ = 0.973) between the visual and automated examination regarding positive/negative discrimination. In sera with single pattern, correct pattern recognition was observed in 94.6% of the samples. The efficiency of automated recognition for single pattern varied for the different patterns. The automatically determined patterns were correct and complete in 1071 of 1620 cases and correct and meaningful but not complete ("main pattern") in another 405 cases, enabling main pattern recognition in 91.1% of all cases. Referring to the titers evaluation, the results within the next titer were considered to be consistent. In 1603 positive sera both by visual and automated evaluation, titers of 1514 sample were consistent, accounting for 94.4%. CONCLUSION: Attributed to the performance characteristics, EUROPattern system is suitable for clinical use as its high degree of automation and result reliability, and may help clinical laboratories to standardize of IIF evaluation.

Diagnostic value of alpha-fetoprotein combined with neutrophil-to-lymphocyte ratio for hepatocellular carcinoma.

BACKGROUND: To investigate the diagnostic performance of alpha-fetoprotein (AFP) and neutrophil-to-lymphocyte ratio (NLR) as well as their combinations with other markers. METHODS: Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), AFP and levels as well as the numbers of neutrophils and lymphocytes of all enrolled patients were collected. The NLR was calculated by dividing the number of neutrophils by the number of lymphocytes. Receiver operating characteristic (ROC) curve analysis was conducted to determine the ability of each marker and combination of markers to distinguish HCC and liver disease patients. RESULTS: In total, 545 patients were included in this study. The area under the ROC curve (AUC) values for AFP, ALT, AST, and NLR were 0.775 (0.738-0.810), 0.504 (0.461-0.547), 0.660 (0.618-0.699), and 0.738 (0.699-0.774) with optimal cut-off values of 24.6 ng/mL, 111 IU/mL, 27 IU/mL, and 2.979, respectively. Of the four biomarkers, AFP and NLR showed comparable specificity (0.881 and 0.858) and sensitivity (0.561 and 0.539). The combination of AFP and NLR showed the highest AUC (0.769) with a significantly higher sensitivity (0.767) and a lower specificity (0.773) compared to AFP or NLR alone, and it had the highest sum of sensitivity and specificity (1.54) among all combinations. In patients with AFP < 20 ng/mL, the NLR showed the highest AUC and combination with other markers did not improve the diagnostic accuracy. CONCLUSIONS: Our data indicate that the combination of AFP and NLR offers better diagnostic performance than either marker alone for differentiating HCC from liver disease, which may benefit clinical screening.

Serum ARCHITECT PIVKA-II reference interval in healthy Chinese adults: Sub-analysis from a prospective multicenter study.

BACKGROUND: Protein induced by vitamin K absence or antagonist-II (PIVKA-II) has been widely used as a biomarker for liver cancer diagnosis in Japan for decades. However, the reference intervals for serum ARCHITECT PIVKA-II have not been established in the Chinese population. Thus, this study aimed to measure serum PIVKA-II levels in healthy Chinese subjects. METHODS: This is a sub-analysis from the prospective, cross-sectional and multicenter study (ClinicalTrials.gov Identifier: NCT03047603). A total of 892 healthy participants (777 Han and 115 Uygur) with complete health checkup results were recruited from 7 regional centers in China. Serum PIVKA-II level was measured by ARCHITECT immunoassay. All 95% reference ranges were estimated by nonparametric method. RESULTS: The distribution of PIVKA-II values showed significant difference with ethnicity and sex, but not age. The 95% reference range of PIVKA-II was 13.62-40.38 mAU/ml in Han Chinese subjects and 15.16-53.74 mAU/ml in Uygur subjects. PIVKA-II level was significantly higher in males than in females (P < 0.001). The 95% reference range of PIVKA-II was 15.39-42.01 mAU/ml in Han males while 11.96-39.13 mAU/ml in Han females. CONCLUSIONS: The reference interval of serum PIVKA-II on the Architect platform was established in healthy Chinese adults. This will be valuable for future clinical and laboratory studies performed using the Architect analyzer. Different ethnic backgrounds and analytical methods underline the need for redefining the reference interval of analytes such as PIVKA-II, in central laboratories in different countries.

Serum reference interval of ARCHITECT alpha-fetoprotein in healthy Chinese Han adults: Sub-analysis of a prospective multi-center study.

OBJECTIVES: Alpha-fetoprotein (AFP) has been widely used in clinical practice for decades. However, large-scale survey of serum reference interval for ARCHITECT AFP is still absent in Chinese population. This study aimed to measure serum AFP levels in healthy Chinese Han subjects, which is a sub-analysis of an ongoing prospective, cross-sectional, multi-center study (ClinicalTrials.gov Identifier: NCT03047603). METHODS: This analysis included a total of 530 participants (41.43±12.14years of age on average, 48.49% males), enrolled from 5 regional centers. Serum AFP level was measured by ARCHITECT immunoassay. Statistical analysis was performed using SAS 9.4 and R software. RESULTS: AFP distribution did not show significant correlation with age or sex. The overall median and interquartile range of AFP was 2.87 (2.09, 3.83) ng/mL. AFP level did not show a trend of increasing with age. The new reference interval was 2.0-7.07ng/mL (LOQ- 97.5th percentiles). CONCLUSIONS: The reference interval for ARCHITECT AFP is updated with the data of adequate number of healthy Han adults. This new reference interval is more practical and applicable in Chinese adults.