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Purpose Our purpose was to compare the performance of prostate-specific membrane antigen (PSMA)-positron emission tomography (PET) traditional fixed threshold (FT) and newly-established Prostate Imaging Reporting and Data System (PI-RADS)-based segmented threshold (ST) for diagnosing clinically significant prostate cancer (csPCa).Methods The study retrospectively included 218 patients who underwent multiparametric magnetic resonance imaging (mpMRI) and PSMA-PET examination for suspected prostate cancer (PCa) from January 2018 to November 2021. Lesions with Gleason score (GS) ≥ 3 + 4 were diagnosed as csPCa. In PSMA-PET maximum standardized uptake value (SUVmax), the FT for all the lesions and ST for lesions with different PI-RADS score for diagnosing csPCa were determined by receiver operating characteristic (ROC) curves analysis and compared with Z test. The McNemar test was used to compare sensitivity and specificity.Results Among the 218 patients, there were 113 csPCa and 105 non-csPCa. The PSMA-PET FT was SUVmax > 5.3 (area under the curve, AUC = 0.842) and STs for PI-RADS 3/4/5 were SUVmax > 4.2/5.7/6.0 (AUCs = 0.870/0.867/0.882), respectively. The AUC of PSMA-PET ST was higher than that of PSMA-PET FT (0.872 vs. 0.842), especially for PI-RADS 3 (0.870 vs. 0.653). Multimodality diagnostic criteria combining PSMA-PET ST and PI-RADS scores of mpMRI was established and its AUC was higher than that of PSMA-PET ST (0.893 vs. 0.872), and significantly higher than that of PSMA-PET FT (0.893 vs. 0.842) with an improvement in sensitivity (93% vs. 78%, p 0.05).Conclusions For diagnosing csPCa, PI-RADS-based PSMA-PET ST achieved better performance than traditional FT, especially for PI-RADS 3 lesions.

Purpose: 68Ga-FAPI-04 PET imaging has shown clinical advantages for detecting and staging various solid tumor types, including gastrointestinal cancer. This study aims to compare the diagnostic efficacy of 68Ga-FAPI-04 PET and 18F-FDG PET for detecting anastomotic recurrence in postoperative patients with gastrointestinal cancer and to characterize the pattern of 68Ga-FAPI-04 uptake at surgical wounds post-surgery. Methods: This study involved 63 gastrointestinal cancer patients who underwent 68Ga-FAPI-04 and 18F-FDG PET/CT imaging, or 68Ga-FAPI-04 PET/CT imaging only for postoperative surveillance after curative surgical resection. The SUVmax at surgical wounds (anastomotic sites and abdominal incision sites) and its corresponding ratio compared to background were assessed. Endoscopic pathology confirmed anastomotic recurrence or it was ruled out by imaging and clinical follow-up. The sensitivity, specificity, positive and negative predictive values (PPV and NPV), and accuracy of the two PET imaging in detecting anastomotic recurrence were compared based on the analysis of paired FAPI-FDG PET imaging. Relationships between tracer uptake at surgical wounds and postoperative time were also analyzed. Results: Sensitivity, specificity, PPV, NPV, and accuracy of detecting anastomotic recurrence were 100.0%, 87.3%, 41.7%, 100.0%, and 88.3% for 68Ga-FAPI-04 PET imaging, and 60.0%, 81.8%, 23.1%, 95.7%, and 80.0% for 18F-FDG PET imaging respectively. Compared with non-recurrent patients, the recurrent patients exhibited a significantly higher anastomotic SUVmax and ratio on FAPI-PET imaging (SUVmax : 9.92±4.36 vs. 2.81±1.86, P =0.002; Ratio: 5.11±1.99 vs. 2.23±1.17, P 68Ga-FAPI-04 PET displayed a significantly higher SUVmax ratio at surgical wounds than 18F-FDG PET imaging (anastomotic sites: 2.57±1.61 vs. 1.76±0.74, P =0.001; abdominal incision sites: 2.14±1.47 vs. 1.65±1.12, P =0.029). Although 68Ga-FAPI-04 PET signal at surgical wounds showed a slight trend to decrease over time (anastomotic SUVmax : r=-0.2830, P =0.0223; incisional SUVmax : r=-0.4549, P 0.05). Conclusion: The surveillance power of 68Ga-FAPI-04 PET is superior to 18F-FDG PET in postoperative anastomotic recurrence of gastrointestinal cancer, but the positive predictive value was limited due to wound healing inference. Therefore, combined surveillance methods were suggested instead of relying on 68Ga-FAPI-04 or 18F-FDG PET only.

Background and Aims: The aims of this study were to establish a maximum standardized uptake value (SUVmax) cutoff to discriminate clinically significant prostate cancer (csPCa) from benign prostate disease (BPD) by 68Ga-labeled prostate-specific membrane antigen (68Ga-PSMA-11) positron emission tomography/computed tomography (PET/CT) in patients with suspected prostate cancer (PCa), and to perform a prospective real-world validation of this cutoff value. Methods: The study included a training cohort to identify an SUVmax cutoff value and a prospective real-world cohort to validate it. A retrospective analysis assessed 135 patients with suspected PCa in a large tertiary care hospital in China who underwent 68Ga-PSMA-11 PET/CT. All patients were suspected of having PCa based on symptoms, digital rectal examination (DRE), total prostate-specific antigen (tPSA) level, and multiparameter magnetic resonance imaging (mpMRI). The 68Ga-PSMA PET/CT results were evaluated using histopathological results from transrectal ultrasound-guided 12-core biopsy with necessary targeted biopsy as references. Patients with Gleason scores (GS) ≥7 from the biopsy results were diagnosed with csPCa, and patients with negative biopsy and follow-up results were diagnosed with BPD. Receiver operating characteristic (ROC) curve analysis was used to identify the optimal SUVmax cutoff value. The cutoff value was prospectively validated in 58 patients with suspected PCa. The diagnostic benefits of the cutoff value for clinical decision making were also evaluated. Results: According to ROC curve analysis, the most appropriate SUVmax cutoff value for discriminating csPCa from BPD was 5.30 (sensitivity, 85.85%; specificity, 86.21%; area under the curve [AUC], 0.893). The cutoff achieved a sensitivity of 83.33%, a specificity of 81.25%, a positive predictive value (PPV) of 92.11%, a negative predictive value (NPV) of 65.00%, and an accuracy of 82.76% in the prospective validation cohort. Metastases were used as an indicator to reduce false negative results in patients with SUVmax ≤ 5.30. In patients without metastases, an SUVmax value of 5.30 was also the best cutoff to diagnose localized csPCa (sensitivity, 80.43%; specificity, 86.21%; AUC, 0.852). The cutoff discriminated localized csPCa from BPD with a sensitivity of 76.19%, a specificity of 81.25%, a PPV of 84.21%, an NPV of 72.22%, and an accuracy of 78.38% in the prospective validation cohort. The cutoff, combined with metastases, achieved an accuracy of 89.12% in all patients, increasing accuracy by 8.29% and reducing equivocal results compared with manual reading. There was a strong correlation between SUVmax and PSMA expression (rs = 0.831, P < 0.001) and a moderate correlation between SUVmax and GS (rs = 0.509, P < 0.001). The PSMA expression and SUVmax values of patients with csPCa were significantly higher than those of patients with BPD (P < 0.001). Conclusion: We established and prospectively validated the best SUVmax cutoff value (5.30) for discriminating csPCa from BPD with high accuracy in patients with suspected PCa. 5.30 is an effective cutoff to discriminate csPCa patients with or without metastases. The cutoff may provide a potential tool for the precise identification of csPCa by 68Ga-PSMA PET/CT, ensuring high accuracy and reducing equivocal results.

Rare-earth orthoferrite SmFeO3 is an outstanding single-phase multiferroic material, holding great potential in novel low-power electronic devices. Nevertheless, simultaneous magnetic and ferroelectric orders as well as magnetoelectric (ME) coupling effect at room temperature (RT) in this system have not been demonstrated yet. In this study, epitaxial SmFeO3 films were successfully prepared onto tensile-strain Nb-SrTiO3 (Nb-STO) substrates by a pulsed laser deposition (PLD) method. Measurement results show that the films exhibit obvious ferromagnetic and ferroelectric orders at RT. Meanwhile, the magnetic anisotropy gradually changes from out-of-plane (OP) to in-plane (IP) direction with increasing film thickness, which is attributed to the variations of O 2p-Fe 3d hybridization intensity and Fe 3d-orbit occupancy caused by the strain-relaxed effect. Moreover, electrically driven reversible magnetic switching further proves that the SmFeO3 films exhibit the RT ME coupling effect, suggesting promising applications in new-generation electric-write magnetic-read data storage devices.

Background Osteoblastoma (OB) is an intermediate lesion, which makes the accurate preoperative diagnosis very important. 99mTc-methylene diphosphonate (99mTc-MDP) bone scan and SPECT/CT imaging were evaluated for their diagnostic value in spinal OB. Methods This study was a retrospective analysis of patients with spinal OB lesions confirmed by pathology and diagnosed with bone scan and SPECT/CT for preoperative diagnosis from January 2008 to December 2018. The uptake levels of OB on planar bone scan were divided into low, medium, and high groups by visual assessment referring to the uptake of the normal rib, spine, and bladder. X-ray, CT, MRI, bone scan, and SPECT/CT imaging of the patients were analyzed for characteristics summary. Results Twenty-five patients were diagnosed for spinal OB (17 males and 8 females with a proportion of 2.1:1), and the average age was 26.8 ± 10.8 years (range 5~59). There were 8 lesions located in the cervical, 6 in the thoracic, and 11 in the lumbar vertebrae. Twenty-four lesions involved posterior elements, especially the pedicles (14/25). Symptoms were predominantly painful with a duration of 18.3 ± 13.9 months (range 0.5~60 months). The lesion size ranged from 9 to 35 mm. All the lesions were low to high uptake in the planar bone scan, and the percentages of low to high levels were 1 (4%), 8 (32%), and 16 (64%) cases. Conclusions Spinal OB mainly involved the posterior area, and elderly patients should be considered as well. SPECT/CT combined the characteristics of bone uptake and anatomical features of bone tumors, proving its one-in-all diagnostic value for spinal OB and other osteogenic tumors.

Thin films with perpendicular magnetic anisotropy (PMA) play an essential role in the development of technologies due to their excellent thermal stability and potential application in devices with high density, high stability, and low energy consumption. Many studies have focused on the relationship between the resistivity of heavy metals and the PMA of the neighbouring magnetic metals in magnetic multi-layered films. However, reports on the effects of heavy metals non-adjacent to the magnetic metals on the PMA are rare. Herein, we demonstrate the influence of the heavy metal Ta underlayer non-adjacent to the magnetic Co layer on the PMA and thermal stability in the Ta/Pt/Co/Pt heterostructures. A type of amorphous Ta film having an ultra-high resistivity (ρmax = 3.9 × 105 μΩ cm) was optimized by DC sputtering at a high sputtering Ar pressure, low sputtering power, and large target-to-substrate distance. The value of resistivity is three orders of magnitude higher than that of the β-Ta underlayer. We found that this special Ta underlayer can effectively improve the PMA and thermal stability of the magnetic Co layer based on the anomalous Hall and planar Hall effect measurements. The maximum magnetic anisotropic field reaches 1.1 T at a low temperature. It is very likely that the ultra-high resistivity leads to the increase in the additional electron scattering in the Ta/Pt interface, while the latter results in the enhancement of the PMA and thermal stability in the structure. These results reveal the inherent relationship between the resistivity of the heavy metal underlayer and PMA, and provide a novel approach to improve the PMA and thermal stability of heavy metal/magnetic metal multi-layered films.

Objectives Dynamic contrast-enhanced MRI (DCE-MRI) with Extended Tofts Linear (ETL) model has been used in tissue and tumor evaluation. However, its reliability and reproducibility in pancreatic evaluation has been unclear. It is also unclear whether pancreatic DCE-MRI pharmacokinetic parameters were consistent and stable among different pancreatic regions, ages and genders. Methods Pancreatic pharmacokinetic parameters of 54 volunteers were calculated using DCE-MRI with ETL model. Firstly, Intra- and inter-observer reproducibility was evaluated using intra-class correlation coefficient (ICC) and coefficient of variation (CoV). Secondly, subgroup evaluation of pancreatic DCE-MRI pharmacokinetic parameters was performed. 54 subjects were divided into three groups in virtue of pancreatic region, three groups according to age, two groups according to gender, which pharmacokinetic parameters among and between different groups were calculated and compared. Results There was excellent agreement and low variability of intra- and inter-observer to pancreatic DCE-MRI pharmacokinetic parameters. The intra- and inter-observer ICCs of Ktrans, kep, ve, vp were 0.971, 0.952, 0.959, 0.944 and 0.947, 0.911, 0.978, 0.917, respectively. The intra- and inter-observer CoVs of Ktrans, kep, ve, vp were 9.98%, 5.99%, 6.47%, 4.76% and 10.15%, 5.22%, 6.28%, 5.40%, respectively. There were no significant differences of Ktrans, kep among different pancreatic regions, among different age groups, between male and female groups (P all > 0.10). Only, pancreatic ve of old group was higher than that of young and middle-aged groups (P = 0.042, 0.001), and vp of pancreatic head was higher than that of pancreatic body and tail (P = 0.014, 0.043). Conclusions DCE-MRI with ETL model is reliable and reproducible for quantitative assessment of pancreatic pharmacokinetic parameters. ve varies with age and vp varies with pancreatic region, which can provide guidance for the selection of normal reference in the pharmacokinetics study of pancreatic diseases.

Purpose Gene mutations are mutually exclusive in non-small cell lung cancer (NSCLC). Using EGFR and KRAS as examples, this study aims to assess the significance of mutation mutual exclusion information in the optimization of radiomics algorithms for predicting gene mutation.Methods We retrospectively analyzed 161 NSCLC patients with 18F-FDG PET/CT scans and EGFR and KRAS gene mutation data. Patients were randomly divided into training and testing cohorts. The Pyradiomics toolkit was used for radiomics feature extraction. Based on these features, radiomics score (RS) models were developed for predicting KRAS mutations using the gradient boosting decision tree (GBDT) algorithm. Furthermore, to investigate the value of adding mutation mutual exclusion information, a composite model combining PET/CT RS and EGFR mutation status was developed using logistic regression. The area under the curve (AUC), specificity, sensitivity, and accuracy were calculated for model performance evaluation in the training and test cohorts. To test the generalizability of this optimization method, models for predicting EGFR mutation were established in parallel, with or without adding KRAS gene mutation information.Results Compared with CT, the PET/CT based RS model exhibited higher AUC (KRAS: 0.792 vs 0.426; EGFR: 0.786 vs 0.644). By integrating EGFR mutation information into the PET/CT RS model, the AUC, accuracy, and specificity for predicting KRAS mutations were all elevated in the test cohort (0.928, 0.857, 0.897 vs 0.792, 0.755, 0.769). Conversely, the composite model for predicting EGFR mutations could also be optimized by adding KRAS gene mutation information (AUC, accuracy, and specificity: 0.877, 0.776, 0.700 vs 0.786, 0.694, 0.567). By adding EGFR and KRAS exclusive mutation information, respectively, the composite model corrected 55.4% and 30.7% false positive cases produced by the PET/CT RS model in the test cohort, without sacrificing sensitivity.Conclusion Integrating the mutation status of a known gene is a potential method to optimize radiomics models for predicting another gene mutation. This method may help predict unconventional gene mutations when the second biopsy is clinically difficult to carry out.

In this work, the magnetic and transport properties of La0.7Ca0.3MnO3 (LCMO) films are compared with films capped with Fe3O4. The capping layers for films with the thicknesses of 50 nm and 100 nm broadened the metal–insulator transition, though they produced rather few changes to other properties. The results were dramatically different for a 20-nm-thick LCMO layer compared to other thicker films. The metal–insulator transition temperature increased from 160 to 200 K for capped LCMO film despite the fact that the capping layer reduced the magnitude of magnetization. The temperature of maximum magnetoresistance (MR) shifted from 115 to 185 K. However, its magnitude, 1500% at 5 T, remained unchanged due to capping. This behavior was attributed to atomic inter-diffusion at the LCMO/Fe3O4 interface which resulted in the generation of Mn2+ ions. These results are of great significance and suggest a promising future for both the fundamental research and device applications involving thin films of LCMO.

Perpendicular magnetic anisotropy (PMA) plays a critical role in spintronics, giving rise to improvements in fundamental research and industrial production. Generally, PMA originates mainly from the spin–orbit interaction with perpendicular orbital moment. However, electron orbitals are difficult to tune once they emerge. Here, we propose a simple and effective method for preparing (001)-oriented ultrathin La0.67Sr0.33MnO3 (LSMO) films with PMA, which is induced by compressive strain and surface symmetry breaking. Moreover, PMA was effectively strengthened by means of annealing under applied magnetic field. X-ray linear dichroism spectra reveal that PMA should be attributed to the preferential occupancy of the 3z2 − r2 orbital in LSMO films. The results presented here show that PMA can be manipulated by orbital reconstruction in perovskite manganite films under compressive strain through a simple and effective strategy. These findings illustrate a new method for designing and controlling magnetic anisotropy and might advance fundamental applications of orbital physics and spintronics.

In this work, epitaxial growth of LaMnO3 thin films on different substrates using pulsed laser deposition under tensile and compressive strain was studied. The intrinsic exchange bias effect was observed in the single A-type antiferromagnetic LaMnO3 films no matter whether the tensile or compressive strain was supplied by the substrates. Due to the lattice mismatch between the film and different substrates, the intense strain can induce MnO6 octahedral rotation in the bottom region of the film neighboring the substrate, which leads to the distortion of MnO6 octahedron and the net magnetic behavior. However, the upper part maintains the original A-type antiferromagnetic order due to strain relaxation. The exchange bias effect in single films is attributed to the coupling between the bottom canted magnetic part and the upper antiferromagnetic region. The observation of exchange bias in single films on different substrates enables the emergence of a new class of biasing components in spintronics, which are based on strain-engineering.

PurposePLND (pelvic lymph node dissection)-validated nomograms are widely accepted clinical tools to determine the necessity of PLND by predicting the metastasis of lymph nodes (LNMs) in pelvic region. However, these nomograms are in lacking of a threshold to predict the metastasis of extrareolar lymph nodes beyond pelvic region, which is not suitable for PLND. The aim of this study is to evaluate a threshold can be set for current clinical PLND-validated nomograms to predict extrareolar LN metastases beyond pelvic region in high-risk prostate cancer patients, by using 68Ga-PSMA PET/CT as a reference to determine LN metastases (LNMs).Experimental DesignWe performed a retrospective analysis of 57 high-risk treatment-naïve PC patients in a large tertiary care hospital in China who underwent 68Ga-PSMA-617 PET/CT imaging. LNMs was detected by 68Ga-PSMA-617 PET/CT and further determined by imaging follow-up after anti-androgen therapy. The pattern of LN metastatic spread of PC patients were evaluated and analyzed. The impact of 68Ga-PSMA PET/CT on clinical decisions based on three clinical PLND-validated nomograms (Briganti, Memorial Sloan Kettering Cancer Center, Winter) were evaluated by a multidisciplinary prostate cancer therapy team. The diagnostic performance and the threshold of these nomograms in predicting extrareolar LNMs metastasis were evaluated via receiver operating characteristic (ROC) curve analysis.ResultsLNMs were observed in 49.1% of the patients by 68Ga-PSMA PET/CT, among which 65.5% of LNMs were pelvic-regional and 34.5% of LNMs were observed in extrareolar sites (52.1% of these were located above the diaphragm). The Briganti, MSKCC and Winter nomograms showed that 70.2%-71.9% of the patients in this study need to receive ePLND according to the EAU and NCCN guidelines. The LN staging information obtained from 68Ga-PSMA PET/CT would have led to changes of planned management in 70.2% of these patients, including therapy modality changes in 21.1% of the patients, which were mainly due to newly detected non-regional LNMs. The thresholds of nomograms to predict non-regional LNMs were between 64% and 75%. The PC patients with a score >64% in Briganti nomogram, a score >75% in MSKCC nomogram and a score >67% in Winter nomogram were more likely to have non-regional LNMs. The AUCs (Area under curves) of the clinical nomograms (Briganti, MSKCC and Winter) in predicting non-regional LNMs were 0.816, 0.830 and 0.793, respectively.ConclusionsBy using 68Ga-PSMA PET/CT as reference of LNM, the PLND-validated clinical nomograms can not only predict regional LNMs, but also predict non-regional LNMs. The additional information from 68Ga-PSMA PET/CT may provide added benefit to nomograms-based clinical decision-making in more than two-thirds of patients for reducing unnecessary PLND. We focused on that a threshold can be set for current clinical PLND-validated nomograms to predict extrareolar LN metastases with an AUC accuracy of about 80% after optimizing the simple nomograms which may help to improve the efficiency for PC therapy significantly in clinical practice.

Background Osteoblastoma (OB) is an intermediate lesion, which makes the accurate preoperative diagnosis very important. 99mTc-methylene diphosphonate (99mTc-MDP) bone scan and SPECT/CT imaging were evaluated for their diagnostic value in spinal OB. Methods This study was a retrospective analysis of patients with spinal OB lesions confirmed by pathology and diagnosed with bone scan and SPECT/CT for preoperative diagnosis from January 2008 to December 2018. The uptake levels of OB on planar bone scan were divided into low, medium, and high groups by visual assessment referring to the uptake of the normal rib, spine, and bladder. X-ray, CT, MRI, bone scan, and SPECT/CT imaging of the patients were analyzed for characteristics summary. Results Twenty-five patients were diagnosed for spinal OB (17 males and 8 females with a proportion of 2.1:1), and the average age was 26.8 ± 10.8 years (range 5~59). There were 8 lesions located in the cervical, 6 in the thoracic, and 11 in the lumbar vertebrae. Twenty-four lesions involved posterior elements, especially the pedicles (14/25). Symptoms were predominantly painful with a duration of 18.3 ± 13.9 months (range 0.5~60 months). The lesion size ranged from 9 to 35 mm. All the lesions were low to high uptake in the planar bone scan, and the percentages of low to high levels were 1 (4%), 8 (32%), and 16 (64%) cases. Conclusions Spinal OB mainly involved the posterior area, and elderly patients should be considered as well. SPECT/CT combined the characteristics of bone uptake and anatomical features of bone tumors, proving its one-in-all diagnostic value for spinal OB and other osteogenic tumors.

Recent theoretical studies indicated that the Curie temperature of perovskite manganite thin films can be increased by more than an order of magnitude by applying appropriate interfacial strain to control orbital ordering. In this work, we demonstrate that the regular intercalation of BaTiO3 layers between La0.67Sr0.33MnO3 layers effectively enhances ferromagnetic order and increases the Curie temperature of La0.67Sr0.33MnO3/BaTiO3 superlattices. The preferential orbital occupancy of eg(x 2 –y 2 ) in La0.67Sr0.33MnO3 layers induced by the tensile strain of BaTiO3 layers is identified by X-ray linear dichroism measurements. Our results reveal that controlling orbital ordering can effectively improve the Curie temperature of La0.67Sr0.33MnO3 films and that in-plane orbital occupancy is beneficial to the double exchange ferromagnetic coupling of thin-film samples. These findings create new opportunities for the design and control of magnetism in artificial structures and pave the way to a variety of novel magnetoelectronic applications that operate far above room temperature.

We study the magnetic properties of an epitaxial growth bilayer composed of ferromagnetic La0.7Sr0.3MnO3 (LSMO) and paramagnetic LaNiO3 (LNO) on SrTiO3 (STO) substrates. We find that the stack order of the bilayer heterostructure plays a key role in the interfacial coupling strength, and the coupling at the LSMO(top)/LNO(bottom) interface is much stronger than that at the LNO(top)/LSMO(bottom). Moreover, a strong spin glass state has been observed at the LSMO/LNO interface, which is further confirmed by two facts: first, that the dependence of the irreversible temperature on the cooling magnetic field follows the Almeida-Thouless line and, second, that the relaxation of the thermal remnant magnetization can be fitted by a stretched exponential function. Interestingly, we also find an exchange bias effect at the LSMO/LNO bilayer below the spin glass freezing temperature, indicating that the exchange bias is strongly correlated with the spin glass state at its interface.

A SiO 2 -Co film with a Pt bottom electrode and an Au top electrode was deposited by magnetron sputtering at room temperature. The sample exhibits bipolar resistive switching properties. Both oxygen vacancies and Co nanoparticles in the SiO 2 -Co film contribute to resistive switching properties and the formation of conducting filaments. The sample, at high and low resistance states, exhibits magnetoresistance at 300 K and 10 K, respectively; this may be due to spin-dependent tunneling between Co particles through the SiO 2 barriers. Thus, the combination of resistive switching and magnetoresistance in a simple Pt/SiO 2 -Co/Au structure leads to the formation of multiple resistance states, which is promising for future applications of multiple-state non-volatile storage.

Artificial heterostructures based on LaNiO3 (LNO) have been widely investigated with the aim to realize the insulating antiferromagnetic state of LNO. In this work, we grew [(La0.7Sr0.3MnO3)5-(LaNiO3)n]12 superlattices on (001)-oriented SrTiO3 substrates by pulsed laser deposition and observed an unexpected exchange bias effect in field-cooled hysteresis loops. Through X-ray absorption spectroscopy and magnetic circular dichroism experiments, we found that the charge transfer at the interfacial Mn and Ni ions can induce a localized magnetic moment. A remarkable increase of exchange bias field and a transition from metal to insulator were simultaneously observed upon decreasing the thickness of the LNO layer, indicating the antiferromagnetic insulator state in 2 unit cells LNO ultrathin layers. The robust exchange bias of 745 Oe in the superlattice is caused by an interfacial localized magnetic moment and an antiferromagnetic state in the ultrathin LNO layer, pinning the ferromagnetic La0.7Sr0.3MnO3 layers...

The ferroelectric HfO2 thin film has attracted a lot of research interest due to being Pb free and its excellent compatibility with the Si-based semiconductor process. However, methods to obtain thicker HfO2 thin films with strong ferroelectricity have yet to be explored. In this work, a 50 nm-thick La-doped HfO2 thin film was prepared using pulsed laser deposition, and significant room temperature ferroelectricity with a remnant polarization (Pr) of 27 µC/cm2 was achieved through annealing in N2 with a rapid-heating-temperature process. The ferroelectricity is mainly related to the increase in the content of the (002)-oriented orthogonal phase formed by the rapid-heating-temperature treatment. Furthermore, this special annealing process was verified in a 50 nm-thick Tm-doped HfO2 film, and the Pr of 48 µC/cm2 was observed. This value is the highest value reported so far in doped HfO2 films with a thickness of 50 nm or greater. These results provide a new approach to prepare thicker ferroelectric HfO2-based thin films.

With the goal of observing and explaining the unexpected exchange bias effect in paramagnetic LaNiO3-based superlattices, a wide range of theoretical and experimental research has been published. Within the scope of this work, we have grown high-quality epitaxial LaMnO3(n)-LaNiO3(n) (LMO/LNO) superlattices (SLs) along (001)-, (110)-, and (111)-oriented SrTiO3 substrates. The exchange bias effect is observed in all cases, regardless of growth orientation of the LMO/LNO SLs. As a result of a combination of a number of synchrotron based x-ray spectroscopy measurements, this effect is attributed to the interfacial charge transfer from Mn to Ni ions that induces localized magnetic moments to pin the ferromagnetic LMO layer. The interaction per area between interfacial Mn and Ni ions is nearly consistent and has no effect on charge transfer for different orientations. The discrepant charge transfer and orbital occupancy can be responsible for the different magnetic properties in LMO/LNO superlattices. Our experimental results present a promising advancement in understanding the origin of magnetic properties along different directions in these materials.

In this work, we have successfully grown high quality epitaxial [Formula: see text]-Ga2O3 thin films on [Formula: see text]-Ga2O3 (100) and Al2O3(0001) substrates using pulsed laser deposition (PLD). By optimizing temperature and oxygen pressure, the best conditions were found to be 650–700∘C and 0.5[Formula: see text]Pa. To further improve the quality of hetero-epitaxial [Formula: see text]-Ga2O3, the sapphire substrates were pretreated for atomic terraced surface by chemical cleaning and high temperature annealing. From the optical transmittance measurements, the films grown at 600–750∘C exhibit a clear absorption edge at deep ultraviolet region around 250–275[Formula: see text]nm wavelength. High resolution transmission electron microscope (HRTEM) images and X-ray diffraction (XRD) patterns demonstrate that [Formula: see text]-Ga2O3(-201)//Al2O3(0001) epitaxial texture dominated the epitaxial oxide films on sapphire substrate, which opens up the possibilities of high power electric devices.

Heavy metal/ferromagnetic metal bi-layered structures that exhibit both strong perpendicular magnetic anisotropy (PMA) and large spin-orbit torque (SOT) efficiency have high potential in high-density, low-power memory, and logic device applications. Here, we report the enhancement of PMA and SOT in Ta/Pt/Co/Ta multi-layered heterostructures through interfacial diffusion. The structures can exhibit PMA fields of 9100 Oe at 300 K and 14100 Oe at 10 K and an effective spin Hall angle (SHA) of 0.61 ± 0.03 at 300 K. These values are larger than the corresponding values reported previously for similar heterostructures. The current-induced magnetization switching was demonstrated. The critical switching current density is on the order of 106 A/cm2, and the corresponding switching efficiency is higher than that reported for similar structures. X-ray absorption spectroscopy and high-angle annular dark-field scanning transmission electron microscopy analyses suggest a strong correlation between the observed PMA and SOT enhancement and the interfacial diffusion during the sputtering growth of the samples. It is very likely that the interfacial diffusion gives rise to enhanced spin-orbit coupling at the interface, while the latter results in enhancement in the PMA, SHA, and switching efficiency in the structure.

High field linear magnetoresistance is an important feature for magnetic sensors applied in magnetic levitating train and high field positioning measurements. Here, we investigate linear magnetoresistance in Pt/FePt/ZnO/Fe/Pt multilayer magnetic sensor, where FePt and Fe ferromagnetic layers exhibit out-of-plane and in-plane magnetic anisotropy, respectively. Perpendicular anisotropy L10-FePt reference layer with large coercivity and high squareness ratio was obtained by in situ substrate heating. Linear magnetoresistance is observed in this sensor in a large range between +5 kOe and −5 kOe with the current parallel to the film plane. This L10-FePt based sensor is significant for the expansion of linear range and the simplification of preparation for future high field magnetic sensors.

[Co(0.6 nm)/ZnO( x nm)] 60 (x=0.3 - 3) films were deposited on glass substrates by magnetron sputtering, and then annealed in vacuum. The large negative magnetoresistance of -10.4% is observed in the as-deposited [Co(0.6 nm)/ZnO(0.4 nm)] 60 film. When ZnO layer thickness is increased from 0.3 to 3 nm, MR ratios of the as-deposited Co/ZnO films are gradually decreased and MR ratios of the annealed films are increased, which might be attributed to the transformation of the structures from the multilayers to granular films during annealing. And the postannealing process makes the magnetism of the films transform from superparamagnetism to ferromagnetism due to Co precipitation in granular films after annealing.

18F-Fluoro-deoxyglucose (FDG) PET/CT can be used to monitor the biological behavior of hepatocellular carcinoma (HCC). Baseline PET/CT has prognostic value in HCC patients, but there is litter knowledge of the PET/CT changes after treatment. We evaluated 27 HCC patients treated with transarterial chemoembolization (TACE) from June 2011 to July 2012, and we investigated the prognostic value of PET/CT. Patients were followed up with regular clinical and laboratory examinations and contrast-enhanced spiral computed tomography (CT). Furthermore, PET/CT assessments were collected and analyzed before (range 1~15 d) and after the first month of TACE (range, 27~45 d). We tested the prognostic value of the tumor standardized uptake value (TSUV) and normal liver SUV(LSUV) according to the VOI (volume of interest). The SUVs were used to assess the relationship between the treatment response and survival. To assess their prognostic value, we evaluated the areas under the receiver operating characteristic (ROC) curves of different SUVs for predicting survival. Finally, the median overall survival (OS) and time to progression (TTP) for 27 patients were 15.4 months (95%CI, 3.3-27.5 months) and 11.4 months (95%CI, 6.7-16.1 months), respectively. The ΔTSUVmax%, based on the VOI, had the highest discriminative prognostic value and the cutoff PET/CT response was 0.1 with a sensitivity of 100% and a specificity of 95.2%. The OS was significantly better in the PET/CT response group than in the PET/CT non-response group (p=0.025). In conclusion, an early interim PET/CT after TACE may have prognostic value for HCC patients treated with TACE, and the ΔTSUVmax% may help in determining the HCCs viability in patients with high baseline and follow-up18F-FDG uptake.

Carbon-doped ZnO films were prepared on c-cut sapphire substrates by conventional PLD method. All films exhibit RT ferromagnetism. However, the samples deposited at low temperature and low pressure with low C concentration show large M s. The substitution of carbon for O in ZnO causes the electron transfer of 3d orbital of Zn ion, which results in the generation of a net spin with one half in the d-orbit of Zn, and accordingly makes ferromagnetism possible. XPS and Auger results indicate the formation of donor defects such as VO or/and Zni in the film, which makes the net spin align, accordingly induces magnetic ordering of the films. Both a certain number of donor defects and the net spin of Zn ions caused by the substitution of O by C are two key factors in inducing magnetic ordering in C-doped ZnO films. Therefore, defect-induced ferromagnetism is reasonable to explain the observed magnetism in our experiment.

We report the dependence of magnetoresistance effect on resistivity (ρ) in Co/ZnO films deposited by magnetron sputtering at different sputtering pressures with different ZnO contents. The magnitude of the resistivity reflects different carrier transport regimes ranging from metallic to hopping behaviors. Large room-temperature magnetoresistance greater than 8% is obtained in the resistivity range from 0.08 to 0.5 Ω · cm. The magnetoresistance value decreases markedly when the resistivity of the films is less than 0.08 Ω · cm or greater than 0.5 Ω · cm. When 0.08 Ω · cm ρ N = 2). The former gives rise to a high room-temperature magnetoresistance effect. When ρ > 0.5 Ω · cm, the spin-independent higher-order hopping (N > 2) comes into play and decreases the tunneling magnetoresistance value. For the samples with ρ

Multilayer films of ZnO with Co were deposited on glass substrates then annealed in a vacuum. The magnetisation of the films increased with annealing but not the magnitude of the magneto-optical signals. The dielectric functions for the films were calculated using the MCD spectra. A Maxwell Garnett theory of a metallic Co/ZnO mixture is presented. The extent to which this explains the MCD spectra taken on the films is discussed., This paper was presented at ICM (2009) and is accepted in this form for the proceedings