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Sintered rare-earth permanent magnets (for example, [Sm.sub.2][Co.sub.17], Sm[Co.sub.5], and [Nd.sub.2][Fe.sub.14]B magnets) are quite brittle and easily crack in the course of fabrication, machining, and application. Here, we report on an investigation of fracture behavior and mechanical characteristics of sintered rare-earth permanent magnets and discuss the origin of rare-earth magnet brittleness. We studied three groups of bending specimens with different orientations, cut from the same block of magnet. The bending strength was measured. The fracture surfaces were carefully observed by scanning electron microscopy and showed that the fracture behavior and bending strength of sintered rare-earth permanent magnets obviously exhibit anisotropy. Sintered Sm-Co magnets tend to cleavage fracture in the close-packed (0001) plane or in the (10[bar.1]1) plane. The fracture mechanism of sintered [Nd.sub.2][Fe.sub.14]B magnet appears to be mainly intergranular fracture. Our analysis indicates that the anisotropy of fracture behavior and mechanical strength of sintered rare-earth magnets is caused by the strong crystal-structure anisotropy and grain texture created by magnetic field alignment during the fabrication process. Index Terms--Anisotropy, fracture behavior, mechanical strength, rare-earth permanent magnets.

Commercial N50 sintered Nd–Fe–B magnets were grain boundary diffusion (GBD) processed with TbHx powders. The diffusion temperature and time dependent microstructure and magnetic properties of the GBD processed magnets were investigated. High remanence and coercivity were obtained when the magnet was GBD processed at 875 °C for 14 h; the coercivity of the magnet increased from 12.57 kOe to 22.65 kOe. The relationships between microstructure and coercivity, remanence, and thermal stability of the GBD processed magnets were analyzed and discussed. [ABSTRACT FROM AUTHOR]

Purpose: Breast cancer is the most common cancer and the leading cause of cancer‐related deaths for women all over the world. Recently, automated breast ultrasound (ABUS) has become a new and promising screening modality for whole breast examination. However, reviewing volumetric ABUS is time‐consuming and lesions could be missed during the examination. Therefore, computer‐aided cancer detection in ABUS volume is extremely expected to help clinician for the breast cancer screening. Methods: We develop a novel end‐to‐end 3D convolutional network for automated cancer detection in ABUS volume, in order to accelerate reviewing and meanwhile to provide high detection sensitivity with low false positives (FPs). Specifically, an efficient 3D Inception Unet‐style architecture with fusion deep supervision mechanism is proposed to attain decent detection performance. In addition, a novel asymmetric loss is designed to help the network balancing false positive and false negative regions, thus improving detection sensitivity for small cancerous lesions. Results: The efficacy of our network was extensively validated on a dataset including 196 patients with 661 cancer regions. Our network obtained a detection sensitivity of 95.1% with 3.0 FPs per ABUS volume. Furthermore, the average inference time of the network was 0.1 second per volume, which largely shortens the conventional reviewing time. Conclusions: The proposed network provides efficient and accurate cancer detection scheme using ABUS volume, and may assist clinicians for more efficient breast cancer screening. [ABSTRACT FROM AUTHOR]

In this article, the phase compositions, microstructures, and magnetic properties of PrNd-free Ce-Fe-B-based sintered magnets with the nominal composition of (Ce0.78Y0.17La0.05)16.28Febal.B7.44M1.94 (at.%: M = Co, Al, Cu, and Nb) have been investigated. It shows that a lamellar crystalline structure is formed in the Ce-Fe-B-based strip casting (SC) alloy. The Y-substituted Ce-Fe-B-based SC alloy is mainly composed of R2Fe14B and RFe2 phases. It suggests that Y substitution is helpful for depressing the $\alpha $ -Fe phase generated in the SC alloy. The island-like intermediate phases exist in the RFe2 region, which are probably caused by the incomplete peritectic reaction during alloy solidification. The Curie temperature $T_{\mathrm {c}}$ of the Y-substituted Ce-Fe-B-based alloy is about 463 K, which is higher than that of the Ce2Fe14B compound ($T_{\mathrm {c}} =424$ K). For the experimental Ce-Fe-B-based sintered magnet without PrNd addition, the remanence $B_{\mathrm {r}}$ of 8.31 kG, the coercivity $H_{\mathrm {cj}}$ of 0.92 kOe, and the maximum energy product (BH)max of 5.30 MGOe have been obtained. A good combination of coercivity $H_{\mathrm {cj}}$ (= 5.57 kOe) and maximum energy product (BH)max (= 20.17 MGOe) has been achieved in the Ce-Fe-B-based blended magnet with PrNd/ $\sum $ RE = 25% prepared using a binary main phase (BMP) method. The heterogeneous elemental distributions and microstructure characteristics of the BMP magnet are also analyzed. [ABSTRACT FROM AUTHOR]

ABUS, or Automated breast ultrasound, is an innovative and promising method of screening for breast examination. Comparing to common B-mode 2D ultrasound, ABUS attains operator-independent image acquisition and also provides 3D views of the whole breast. Nonetheless, reviewing ABUS images is particularly time-intensive and errors by oversight might occur. For this study, we offer an innovative 3D convolutional network, which is used for ABUS for automated cancer detection, in order to accelerate reviewing and meanwhile to obtain high detection sensitivity with low false positives (FPs). Specifically, we offer a densely deep supervision method in order to augment the detection sensitivity greatly by effectively using multi-layer features. Furthermore, we suggest a threshold loss in order to present voxel-level adaptive threshold for discerning cancer vs. non-cancer, which can attain high sensitivity with low false positives. The efficacy of our network is verified from a collected dataset of 219 patients with 614 ABUS volumes, including 745 cancer regions, and 144 healthy women with a total of 900 volumes, without abnormal findings. Extensive experiments demonstrate our method attains a sensitivity of 95% with 0.84 FP per volume. The proposed network provides an effective cancer detection scheme for breast examination using ABUS by sustaining high sensitivity with low false positives. The code is publicly available at https://github.com/nawang0226/abus_code. [ABSTRACT FROM AUTHOR]

Objectives: The diagnostic value of axillary ultrasound (US) for level II and III axillary lymph node metastasis after axillary lymph node dissection for invasive breast cancer is currently not clear. The objectives of this study were to retrospectively analyze the diagnostic value of axillar US for level II and III axillary lymph node metastasis and compare it with palpation and to analyze the US features of level II and III axillary lymph nodes that are predictive of metastatic recurrence during follow‐up. Methods: Cases with level II or III axillary lymph nodes detected by US between January 2005 and December 2017 at a cancer center were divided into 2 groups according to a retrospective analysis of US findings: potential malignancy group and follow‐up group. Biopsy was performed in all patients in the potential malignancy group. In the follow‐up group, the patients were followed for at least 2 years, and biopsy was performed if suspicious US features were detected. Results: The 401 enrolled cases were followed by axillary US and physical examination (PE) for comparison. Finally, 55 axillary metastases were pathologically confirmed (14%). The sensitivity, specificity, and area under the receiver operating characteristic curve for axillary US were 92.7%, 93.9%, and 0.933, respectively, and the corresponding values for PE were 49.1%, 91.3%, and 0.702 (P < .001). An increase in the major or minor axis diameter of the lymph nodes of greater than 2 mm, a Solbiati index value of less than 1.5, and the presence of new suspicious lesions in other regions were significant predictors of lymph node metastasis based on the US findings (P = .013,.006,.015, and.036). Conclusions: Axillary is helpful in the follow‐up of level II and III axillary lymph nodes after axillary lymph node dissection for invasive breast cancer and can detect cancer recurrence earlier than PE. [ABSTRACT FROM AUTHOR]

The effects of rare-earth contents, substitutions, and heat treatment parameters on the impact resistance of the Nd–Fe–B sintered magnets were investigated. Analysis shows that the impact resistance increases linearly with increasing plastic rare-earth-rich phase in the investigated magnets. Heavy rare-earth Dy substitutions for Nd help us to improve the impact resistance. The bending strength and impact resistance during annealing process was investigated. It is found that the annealing process affects the bending strength and impact resistance remarkably. Both the bending strength and the intrinsic coercivity are poor in the as-sintered specimen. In the postsintering annealing process, both of them get improved and the change of intrinsic coercivity is similar to that of the bending strength. Study showed that the optimized heat treatment parameters help us to improve the bending strength and impact resistance of the sintered Nd–Fe–B magnets. Study shows that the sintered Nd–Fe–B magnets with improved impact resistance can be produced by the adjustment of compositions and heat treatment parameters. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to investigate the value of shear wave elastography (SWE) for characterization of breast masses in a Chinese population. Patients and methods: Two thousand two hundred seventy-three women consented to be prospectively enrolled for the characterization of breast masses with ultrasound and SWE. Breast masses were known from symptoms, palpability, and/or previous imaging screening with mammography and/or ultrasound. Correlation of SWE qualitative and quantitative features with malignancy risk and impact on diagnostic performance of combining SWE features were assessed, and the Breast Imaging Reporting and Data System (BI-RADS) scoring was calculated using histopathology as reference. Results: Data of 2,262 masses (median size: 13 mm; range: 1.3–50) from 2,262 patients (median age: 43 years; range: 18–91) were investigated, of which 752 (33.3%) were malignant. Sensitivity and specificity of BI-RADS diagnosis were 97.5% (733/752) and 54.8% (827/1,510), respectively. By logistic regression, the combination of maximum elasticity (Emax) measurements with BI-RADS assessments increased the area under the receiver operating characteristic curve from 0.908 (95% CI: 0.896–0.920) to 0.954 (95% CI: 0.944–0.962). Using Emax of 30 kPa or lower to selectively downgrade BI-RADS 4a masses to follow-up, and Emax of 160 kPa or higher to selectively upgrade BI-RADS 3 lesions to biopsy, specificity significantly increased from 54.8% (827/1,510) to 66.1% (998/1,510) (P [ABSTRACT FROM AUTHOR]

The (R,Ce)–Fe–B magnets have been successfully industrialized in recent years. The mechanical property of sintered permanent magnets is one important aspect of their comprehensive performances, which directly influences the service reliability and the production cost. In this paper, the bending strength, fracture toughness, Vickers hardness, and brittleness index of commercial (R1–xCex)30.5–31.5Febal.B1M1 magnets with different cerium contents have been investigated. The micro-fractures of the magnets were observed by a scanning electron microscopy equipped with energy dispersive X-ray analysis system. It shows that the bending strength and the fracture toughness of (R,Ce)–Fe–B magnets have a downward tendency with increasing Ce content x, while the Vickers hardness of the magnets varies irregularly with Ce contents in this paper. The optimum mechanical properties have been obtained in the (R1–xCex)30.5–31.5Febal.B1M1 magnet with $x = 0.15$ ; the bending strength, fracture toughness and brittleness index of the magnet with $x =0.15$ are obviously superior to those of the ordinary sintered Nd–Fe–B magnets. Some flocculent oxide phases have been discovered in the (R,Ce)–Fe–B magnet with $x = 0.15$ . The flocculent phases may absorb the crack propagating energy, and reduce the stress concentration at a crack tip, which is beneficial to strengthening and toughening of (R,Ce)–Fe–B magnets. However, the mechanical properties are obviously worse for the magnet with $x = 0.45$ (Ce/ $\sum $ RE = 45%). That is probably because the microstructures of the magnet with $x = 0.45$ become deteriorated, in which abnormally large grains have been observed. [ABSTRACT FROM AUTHOR]

Waste Nd–Fe–B sintered magnets (grade 33H) were recycled to manufacture anisotropic sintered magnets by adding Ce-rich alloys. The influences of additive amounts of Ce-rich alloys on the microstructure and magnetic properties of the recycled sintered magnets were investigated. It showed that the recycled sintered Nd–Fe–B magnet without Ce-rich alloy addition has rather lower density; the density of the magnet is slightly raised with increased sintering temperature, but the recycled magnet is prone to oxidation, even cracking. For recycled sintered magnets with Ce-rich alloy addition, the densities of the magnets are upgraded with increasing amounts of Ce-rich alloy, and the magnetic properties are obviously improved. This suggests that Ce-rich alloy plays the important role of sintering-aid in the densification of the recycled magnet. However, the coercivity ( $H_{{\text {cj}}} ) of the recycled magnets is decreased, when the additive amounts of Ce-rich alloy are over 8 wt.%. This is probably because excessive Ce-rich alloy addition can cause RE-rich phase aggregation at the triple grain boundary junctions, and deteriorate the microstructure of the recycled magnets. The recycled magnet with 5 wt.% Ce-rich alloy, sintered at 1080 °C, exhibits the following optimal magnetic properties: Br of 11.67 kGs; H{\text {cj}} of 18.94 kOe; and maximum energy product [(BH)\max ] of 33.1 MGOe. The magnetic properties of the recycled magnets are comparative to those of the waste magnets. Recycled magnets have a higher coercivity and perfect squareness of demagnetization curve ( Hk/H{\text {cj}} =0.972 ). [ABSTRACT FROM AUTHOR]

The forkhead box O (FOXO) transcription factors play important roles in various cancer development including Hepatocellular Carcinoma (HCC). In this study we conducted a hospital-based case control study including 1049 cases (HCC patients) and 1052 controls (non-tumor patients) to examine whether single nucleotide polymorphisms (SNPs) within microRNA (miRNA) target sites of FOXO genes confer HCC susceptibility. A total of three miRNA target site SNPs in the 3’ untranslated regions (UTR) of FOXO1 (rs17592236), FOXO3 (rs4946936) and FOXO4 (rs4503258) were analyzed. No statistically significant differences were found in genotype distribution for rs17592236, rs4946936, and rs4503258 between the HCC patient group and the tumor-free control group using single factor chi-square analysis (P>0.05). However, multivariate logistic regression analysis showed that the CT/TT genotype in rs17592236 was significantly associated with decreased risk of HCC development (P = 0.010, OR = 0.699, 95% CI: 0.526–0.927) as compared to the CC genotype in rs17592236. Additionally, a genetic interaction was found between rs17592236 and rs4503258 (P = 0.003, OR = 0.755, 95% CI: 0.628–0.908). Functional dual luciferase reporter assays verified that the rs17592236 SNP was a target site of human miRNA miR-137. Together, these results indicate that the rs17592236 polymorphism is associated with decreasing of HCC hereditary susceptibility likely through modulating the binding affinity of miR-137 to the 3’UTR in FOXO1 messenger RNA (mRNA). Further knowledge obtained from this study may provide important evidence for the prevention and targeted therapy of HCC. [ABSTRACT FROM AUTHOR]

In this paper, the structure and magnetic properties of the (Ce, Nd)–Fe–B magnets without Dy and Tb substitution have been investigated. The purpose of the investigation is to develop the applicable Ce–Fe–B magnets with Ce content over 50 wt.%. Sintered (Ce, Nd)–Fe–B magnets with the nominal composition of (Nd1−xCex)30(Fe, TM)balB1 ( x=0 –0.75) in wt.% were fabricated by advanced powder metallurgy processes. The effects of Ce substitution on the microstructure and magnetic properties of the (Ce, Nd)–Fe–B magnets were discussed. It was found that the (Ce, Nd)-rich boundary phase with lower melting point is helpful to obtain improved boundary microstructures and refined grain magnets. Good magnetic properties of Br = 13.5 kG, H_{\mathrm {cj}}= 9.5 kOe, and (BH)_{\mathrm {max}} = 42.8$ MGOe were obtained in the Dy-free (Ce, Nd)–Fe–B magnets with 30 wt.% Ce substitution. A higher coercivity (>10 kOe) has been achieved in the Ce–Fe–B type magnets by the modifications of alloy compositions and the optimization of preparation conditions, in which the proportion of Nd and/or Pr is lower than 35 wt.% of the total rare-earth content. [ABSTRACT FROM AUTHOR]

Fractal study was used to the analysis of the fractured surface of commercial N50-type Nd-Fe-B sintered magnets. The strain-stress properties of the specimens indicate that the elastic and plastic deformations occur simultaneously during intergranual cracking. The microfractography of the specimens exhibits typical brittle fracture pattern with some toughness dimples, indicating that plastic deformation has happened in some local areas. A 'line-measuring dimension' Dline was selected to discuss the fracture behavior. The calculated Dline is about 1.28 and 1.29 for the specimens with c-axis parallel and perpendicular to the applied force direction, respectively. The line-measuring dimension analysis indicates that the fracture feature may be isotropic for our studied specimens, which is a bit inconsistent with previous report on the fracture characterization of Nd-Fe-B sintered magnets. More comprehensive fractal study is further needed to confirm the fracture behavior in detail in the future. [ABSTRACT FROM AUTHOR]