Computer-Aided Multiphoton Microscopy Diagnosis of 5 Different Primary Architecture Subtypes of Meningiomas.

Meningiomas rank among the most common intracranial tumors, and surgery stands as the primary treatment modality for meningiomas. The precise subtyping and diagnosis of meningiomas, both before and during surgery, play a pivotal role in enabling neurosurgeons choose the optimal surgical program. In this study, we utilized multiphoton microscopy (MPM) based on 2-photon excited fluorescence and second-harmonic generation to identify 5 common meningioma subtypes. The morphological features of these subtypes were depicted using the MPM multichannel mode. Additionally, we developed 2 distinct programs to quantify collagen content and blood vessel density. Furthermore, the lambda mode of the MPM characterized architectural and spectral features, from which 3 quantitative indicators were extracted. Moreover, we employed machine learning to differentiate meningioma subtypes automatically, achieving high classification accuracy. These findings demonstrate the potential of MPM as a noninvasive diagnostic tool for meningioma subtyping and diagnosis, offering improved accuracy and resolution compared with traditional methods.

Prediction of Ki-67 labeling index, ATRX mutation, and MGMT promoter methylation status in IDH-mutant astrocytoma by morphological MRI, SWI, DWI, and DSC-PWI.

OBJECTIVE: Noninvasive detection of molecular status of astrocytoma is of great clinical significance for predicting therapeutic response and prognosis. We aimed to evaluate whether morphological MRI (mMRI), SWI, DWI, and DSC-PWI could predict Ki-67 labeling index (LI), ATRX mutation, and MGMT promoter methylation status in IDH mutant (IDH-mut) astrocytoma. METHODS: We retrospectively analyzed mMRI, SWI, DWI, and DSC-PWI in 136 patients with IDH-mut astrocytoma.The features of mMRI and intratumoral susceptibility signals (ITSS) were compared using Fisher exact test or chi-square tests. Wilcoxon rank sum test was used to compare the minimum ADC (ADCmin), and minimum relative ADC (rADCmin) of IDH-mut astrocytoma in different molecular markers status. Mann-Whitney U test was used to compare the rCBVmax of IDH-mut astrocytoma with different molecular markers status. Receiver operating characteristic curves was performed to evaluate their diagnostic performances. RESULTS: ITSS, ADCmin, rADCmin, and rCBVmax were significantly different between high and low Ki-67 LI groups. ITSS, ADCmin, and rADCmin were significantly different between ATRX mutant and wild-type groups. Necrosis, edema, enhancement, and margin pattern were significantly different between low and high Ki-67 LI groups. Peritumoral edema was significantly different between ATRX mutant and wild-type groups. Grade 3 IDH-mut astrocytoma with unmethylated MGMT promoter was more likely to show enhancement compared to the methylated group. CONCLUSIONS: mMRI, SWI, DWI, and DSC-PWI were shown to have the potential to predict Ki-67 LI and ATRX mutation status in IDH-mut astrocytoma. A combination of mMRI and SWI may improve diagnostic performance for predicting Ki-67 LI and ATRX mutation status. CLINICAL RELEVANCE STATEMENT: Conventional MRI and functional MRI (SWI, DWI, and DSC-PWI) can predict Ki-67 expression and ATRX mutation status of IDH mutant astrocytoma, which may help clinicians determine personalized treatment plans and predict patient outcomes. KEY POINTS: • A combination of multimodal MRI may improve the diagnostic performance to predict Ki-67 LI and ATRX mutation status. • Compared with IDH-mutant astrocytoma with low Ki-67 LI, IDH-mutant astrocytoma with high Ki-67 LI was more likely to show necrosis, edema, enhancement, poorly defined margin, higher ITSS levels, lower ADC, and higher rCBV. • ATRX wild-type IDH-mutant astrocytoma was more likely to show edema, higher ITSS levels, and lower ADC compared to ATRX mutant IDH-mutant astrocytoma.

Pediatric Extraspinal Subcutaneous Sacrococcygeal Myxopapillary Ependymoma: Case Report and Minireview.

ABSTRACT: A 9-year-old girl presented with a slow-growing and painless mass for 7 months in the soft tissue of the sacrococcygeal region. Magnetic resonance imaging revealed a well-circumscribed solid mass located in the subcutaneous soft tissue of the sacrococcygeal area, but not affecting bone structures. The mass was completely removed, and the disorder was diagnosed as myxopapillary ependymoma. In addition, the MYCN gene amplification status of the tumor was evaluated. Extra-axial ependymomas are very rare tumors with a tendency to metastasis, but they are usually regarded as low-grade ependymomas. Long-time surveillance and follow-up are necessary even after complete excision. Besides, we also discuss the diagnosis of primary soft tissue myxopapillary ependymoma.

Comparison of Conventional, Diffusion, and Perfusion MRI Between Low-Grade and Anaplastic Extraventricular Ependymoma.

OBJECTIVE. The purpose of this study was to investigate and compare conventional MRI, DWI, and dynamic susceptibility contrast-enhanced perfusion-weighted imaging (DSC-PWI) characteristics between low-grade and anaplastic extraventricular ependymomas. MATERIALS AND METHODS. Twenty-six patients with extraventricular ependymomas (19 anaplastic and seven low-grade) who underwent preoperative MRI were enrolled in this retrospective study. Conventional MRI and DWI were performed in all patients; DSCPWI was performed in 15 patients (11 with anaplastic ependymoma and four with low-grade ependymoma). Demographics, conventional MRI features, minimum relative apparent diffusion coefficient (rADCmin), and maximum relative cerebral blood volume (rCBVmax) of the low-grade and anaplastic ependymomas were compared. Diagnostic performance with optimal cutoff values was determined. RESULTS. Anaplastic extraventricular ependymomas were more likely to be located in the superficial supratentorial cerebral hemisphere (p = 0.026) and to present with pial and cortical involvement (p = 0.028 and 0.013, respectively) and necrotic degeneration (p = 0.014). The mean rADCmin ± SD of anaplastic ependymoma was significantly lower than that of low-grade ependymoma (0.8 ± 0.2 vs 1.2 ± 0.3, p = 0.002). The mean rCBVmax of anaplastic ependymoma was significantly higher than that of low-grade ependymoma (15.7 ± 5.3 vs 9.0 ± 4.4, p = 0.042). The cutoff values in grading extraventricular ependymoma were 1.02 for rADCmin and 10.43 for rCBVmax. Combining conventional MRI, DWI, and DSC-PWI allowed the best differentiation of low-grade and anaplastic ependymoma (AUC = 1.00). CONCLUSION. Conventional MRI, DWI, and DSC-PWI techniques may aid in assessing and grading extraventricular ependymomas.

MYB-QKI rearrangement in angiocentric glioma.

AIMS: To evaluate the occurrence and diagnostic value of MYB-QKI rearrangement status in angiocentric glioma (AG) in Chinese patients. MATERIALS AND METHODS: 27 cases were collected from six hospitals, followed by a retrospective analysis of clinical, radiological, and morphological data. MYB protein expression was assessed by immunohistochemical staining (IHC), and the MYB-QKI rearrangement was detected by fluorescence in situ hybridization (FISH). RESULTS: Among the 27 cases (16 males), the median age at surgery was 17 years (range 3 - 43 years); 24 (88.9%) cases had a history of refractory epilepsy, and the mean history of pre-surgical epilepsy was 13 years (range 1.5 - 27 years); 26 (96.3%) cases had lesions located in the superficial cerebrocortical regions, and 1 (3.7%) case had a lesion in the brainstem. Except for the classic histological features, the involvement of superficial cortex extending to the leptomeninges, microcalcification, and cystic pattern with microcystic formations was observed in 11 (40.7%), 3 (11.1%), and 4 (14.8%) cases, respectively. IHC showed that all 27 cases were positive for glial fibrillary acidic protein (GFAP) and vimentin, and negative for neuronal nuclear antigen (NeuN). The positive rates of epithelial membrane antigen (EMA) and D2-40 were 81.5% (22/27) and 74.1% (20/27), respectively. A total of 14 (51.9%) cases were positive for MYB. The rate of Ki-67 proliferation was 1 - 5% in 25 cases, and in 2 cases with anaplastic features it was 10 and 20%. MYB-QKI rearrangement was revealed by FISH examination in 95.8% (23/24) of the AGs, including 3 cases with atypical histological appearance. CONCLUSION: Compared to IHC, FISH was more appropriate for detecting MYB-QKI rearrangement. MYB-QKI rearrangement was detected in the majority of Chinese AG cases, and therefore represents a potential diagnostic biomarker for AG.

Diagnosing pituitary adenoma in unstained sections based on multiphoton microscopy.

PURPOSE: If we can find a new method that can achieve rapid diagnosis of adenoma during operation, it will help surgeon shorten the operation time and enhance the treatment efficacy. This study discusses the feasibility of multiphoton microscopy (MPM) in diagnosing pituitary adenoma. METHOD: MPM, based on two-photon excited fluorescence (TPEF) and second harmonic generation (SHG) is performed for the diagnosis of pituitary adenoma in unstained sections. RESULTS: Our results show that MPM can reveal the variation of reticulin fiber by SHG signals of collagen, combined with the measurement of area of acinus, thickness of collagen fiber and collagen percentage. MPM can further reflect the change of meshwork in normal pituitary and hyperplasia quantitatively. And the characteristics of typical growth patterns of pituitary adenoma are demonstrated by the overlay of SHG and TPEF images. What's more, we can identify the boundary of normal pituitary, hyperplasia and adenoma from MPM images. And the experiment also results verify the feasibility of this method in frozen sections. CONCLUSION: These results indicated that MPM can make a diagnosis of pituitary adenoma by the morphological changes without routine pathological processing including hematoxylin-eosin (H&E) staining and other special staining. Therefore, this technique is expected to help diagnosis of pituitary adenoma during operation.

Simultaneously Enhancing Light Emission and Suppressing Efficiency Droop in GaN Microwire-Based Ultraviolet Light-Emitting Diode by the Piezo-Phototronic Effect.

Achievement of p-n homojuncted GaN enables the birth of III-nitride light emitters. Owing to the wurtzite-structure of GaN, piezoelectric polarization charges present at the interface can effectively control/tune the optoelectric behaviors of local charge-carriers (i.e., the piezo-phototronic effect). Here, we demonstrate the significantly enhanced light-output efficiency and suppressed efficiency droop in GaN microwire (MW)-based p-n junction ultraviolet light-emitting diode (UV LED) by the piezo-phototronic effect. By applying a -0.12% static compressive strain perpendicular to the p-n junction interface, the relative external quantum efficiency of the LED is enhanced by over 600%. Furthermore, efficiency droop is markedly reduced from 46.6% to 7.5% and corresponding droop onset current density shifts from 10 to 26.7 A cm-2. Enhanced electrons confinement and improved holes injection efficiency by the piezo-phototronic effect are revealed and theoretically confirmed as the physical mechanisms. This study offers an unconventional path to develop high efficiency, strong brightness and high power III-nitride light sources.

IDH mutant and 1p/19q co-deleted oligodendrogliomas: tumor grade stratification using diffusion-, susceptibility-, and perfusion-weighted MRI.

PURPOSE: Currently, isocitrate dehydrogenase (IDH) mutation and 1p/19q co-deletion are proven diagnostic biomarkers for both grade II and III oligodendrogliomas (ODs). Non-invasive diffusion-weighted imaging (DWI), susceptibility-weighted imaging (SWI), and dynamic susceptibility contrast perfusion-weighted imaging (DSC-PWI) are widely used to provide physiological information (cellularity, hemorrhage, calcifications, and angiogenesis) of neoplastic histology and tumor grade. However, it is unclear whether DWI, SWI, and DSC-PWI are able to stratify grades of IDH-mutant and 1p/19q co-deleted ODs. METHODS: We retrospectively reviewed the conventional MRI (cMRI), DWI, SWI, and DSC-PWI obtained on 33 patients with IDH-mutated and 1p/19q co-deleted ODs. Features of cMRI, normalized ADC (nADC), intratumoral susceptibility signals (ITSSs), normalized maxim CBV (nCBV), and normalized maximum CBF (nCBF) were compared between low-grade ODs (LGOs) and high-grade ODs (HGOs). Receiver operating characteristic curve and logistic regression were applied to determine diagnostic performances. RESULTS: HGOs tended to present with prominent edema and enhancement. nADC, ITSSs, nCBV, and nCBF were significantly different between groups (all P < 0.05). The combination of SWI and DSC-PWI for grading resulted in sensitivity and specificity of 100.00 and 93.33%, respectively. CONCLUSIONS: IDH-mutant and 1p/19q co-deleted ODs can be stratified by grades using cMRI and advanced magnetic resonance imaging techniques including DWI, SWI, and DSC-PWI. Combined ITSSs with nCBV appear to be a promising option for grading molecularly defined ODs in clinical practice.

The vascular delta-like ligand-4 (DLL4)-Notch4 signaling correlates with angiogenesis in primary glioblastoma: an immunohistochemical study.

Delta-like ligand-4 (DLL4)-Notch signaling is known to play a pivotal role in the regulation of tumor angiogenesis. We had previously found that DLL4 was overexpressed, while Notch1 receptor, which binds to DLL4 during angiogenesis, was absent in the majority of human primary glioblastomas. Thus, DLL4-Notch signaling pathway in the regulation of tumor angiogenesis in primary glioblastoma remains unknown. Tumor tissues from 70 patients with primary glioblastoma were analyzed by immunohistochemistry for expression of components of DLL4-Notch signaling, vascular endothelial growth factor (VEGF), and microvessel density (MVD). Immunohistochemistry results showed that the positive staining of DLL4 and Notch4 was primarily distributed in tumor vascular endothelial cells but rarely detected in tumor cells. However, VEGF, hairy/enhancer of split-1 (HES1; a target gene of Notch signaling), and Notch1-3 expression was seen in both tumor vascular endothelial cells and tumor cells. Univariate analysis showed that the expression levels of VEGF and DLL4, HES1, and Notch4 in tumor endothelial cells were significantly associated with MVD in primary glioblastoma (P < 0.001). Binary logistic regression analysis showed that high expression levels of DLL4, HES1, and Notch4 in tumor endothelial cells were associated with a decrease of MVD in primary glioblastoma, while MVD increased with elevated VEGF expression in contrast. In addition, DLL4, Notch4, and HES1 expression were positively correlated in tumor vascular endothelial cells (P < 0.05). We conclude that the vascular DLL4-Notch4 signaling and VEGF signaling complementing each other plays an important role in the progression of tumor angiogenesis in primary glioblastoma. Graphical abstract A, positive staining of DLL4 in human kidney; B, positive staining of VEGF in human breast cancer; C, positive staining of CD34 in human lung cancer; D, positive staining of HES1 in human breast cancer; E-H, positive staining of Notch1-4: E-F in human lung cancer; G-H in human kidney.

Simultaneous enhancement of magnetic and ferroelectric properties in Dy and Cr co-doped BiFeO3 nanoparticles.

Multiferroic BiFeO3 (BFO), Bi0.95Dy0.05FeO3 and Bi0.95Dy0.05Fe0.95Cr0.05O3 samples were successfully synthesized by a carbon microsphere-assisted sol-gel (CSG) method. X-ray diffraction analysis confirmed a lattice distortion from a rhombohedral structure to a tetragonal structure upon doping Dy and Cr in BFO. The morphology of BFO and doped BFO could be effectively controlled to form nanoparticles, due to the nucleation sites of the carbon microspheres. The co-doping of Dy and Cr in BFO had a significant improvement effect on the magnetic properties, with the remnant magnetization being 0.557 emu g(-1), due to the structural phase transition, size effects and the strong ferromagnetic interaction between Fe(3+)-O-Cr(3+) ions arising from Cr substitution. Meanwhile, the doping of Dy into BFO effectively reduced the leakage current and enhanced the ferroelectric properties. The simultaneous enhancement of magnetic and ferroelectric properties shows the great potential application of Dy- and Cr-co-doped BFO in future multifunctional devices.

Detection of morphologic alterations in rectal carcinoma following preoperative radiochemotherapy based on multiphoton microscopy imaging.

BACKGROUND: Preoperative radiochemotherapy improves outcomes in patients with locally advanced rectal carcinoma, and has been used increasingly in patient management. However, there is a strong clinical need to assess tumor response to neoadjuvant treatment, and a non-invasive technique that allows the precise identification of morphologic changes in tumors would be of considerable clinical interest. METHODS: In this study, we used multiphoton microscopy (MPM) to detect morphologic alterations in rectal adenocarcinomas in patients treated with preoperative radiochemotherapy. RESULTS: MPM was able to identify histopathologic alterations in rectal cancer following preoperative radiochemotherapy, and allowed the qualitative assessment of treatment efficacy and feasibility in relation to dose or strategy. CONCLUSION: These findings may provide the groundwork for evaluating tumor response to neoadjuvant treatment, thus allowing the tailoring of effective treatment doses and strategies.

Co-expression of COX-2 and 5-LO in primary glioblastoma is associated with poor prognosis.

Cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LO) are important factors in tumorigenesis and malignant progression; however, studies of their roles in glioblastoma have produced conflicting results. To define the frequencies of COX-2 and 5-LO expression and their correlation with clinicopathological features and prognosis, tumor tissues from 76 cases of newly diagnosed primary ordinary glioblastoma were examined for COX-2 and 5-LO expression by immunohistochemistry. The expression levels of COX-2 and 5-LO and the relationships between the co-expression of COX-2/5-LO and patient age and gender, edema index (EI), Karnofsky Performance Scale and overall survival (OS) were analyzed. COX-2 and 5-LO were expressed in 73.7 % (56/76) and 92.1 % (70/76) of the samples, respectively. Among the clinicopathological characteristics, only age (>60 years) exhibited a significant association with the high expression of COX-2. No statistically significant correlations were found in the 5-LO cohort. A significant positive correlation was revealed between the COX-2 and 5-LO scores (r = 0.374; p = 0.001). The elevated co-expression of COX-2 and 5-LO was observed primarily in the patients over the age of 60 years. Patients with a high expression of COX-2 had a significantly shorter OS (p < 0.01), whereas the immunoexpression of 5-LO was not associated with the OS of patients with glioblastoma. Survival analysis indicated that simultaneous high levels of COX-2 and 5-LO expression were significantly correlated with poor OS and, conversely, that a low/low expression pattern of these two proteins was significantly associated with better OS (p < 0.05). Moreover, the Cox multivariable proportional hazard model showed that a high expression of COX-2, high co-expression of COX-2 and 5-LO, and a high Ki-67 index were significant predictors of shorter OS in primary glioblastoma, independent of age, gender, EI, 5-LO expression and p53 status. The hazard ratios for OS were 2.347 (95 % CI 1.30-4.25, p = 0.005), 1.900 (95 % CI 1.30-2.78, p = 0.001), and 2.210 (95 % CI 1.19-4.09, p = 0.011), respectively. These results suggest that COX-2 and 5-LO play roles in tumorigenesis and the progression of primary glioblastoma and that the co-expression pattern of COX-2/5-LO may be used as an independent prognostic factor in this disease.

Solitary Langerhans cell histiocytosis of frontal lobe: a case report and literature review.

The brain parenchymal Langerhans cell histiocytosis (LCH) without systemic disease or lytic skull lesions is extremely rare. We report a 23-year-old male presenting with new onset 1 hour seizure with loss of consciousness 20 days prior to admission, and recurrent seizure 2 weeks later. Brain magnetic resonance imaging (MRI) showed an irregularly mass with enhancement involving the right frontal lobe. Microscopically, the lesion was characterized by sheets of Langerhans cells in addition to reactive inflammatory elements. Immunohistochemically, Langerhans cells were positive for Langerin, CD1a and S-100 protein. The patient received no chemotherapy or radiotherapy after surgery. After 24 months of follow-up, no recurrence or other systemic lesions were observed. Although there is no standard treatment for solitary cerebral LCH, the prognosis generally appears to be good.

BrainGridNet: A two-branch depthwise CNN for decoding EEG-based multi-class motor imagery.

Brain-computer interfaces (BCIs) based on motor imagery (MI) enable the disabled to interact with the world through brain signals. To meet demands of real-time, stable, and diverse interactions, it is crucial to develop lightweight networks that can accurately and reliably decode multi-class MI tasks. In this paper, we introduce BrainGridNet, a convolutional neural network (CNN) framework that integrates two intersecting depthwise CNN branches with 3D electroencephalography (EEG) data to decode a five-class MI task. The BrainGridNet attains competitive results in both the time and frequency domains, with superior performance in the frequency domain. As a result, an accuracy of 80.26 percent and a kappa value of 0.753 are achieved by BrainGridNet, surpassing the state-of-the-art (SOTA) model. Additionally, BrainGridNet shows optimal computational efficiency, excels in decoding the most challenging subject, and maintains robust accuracy despite the random loss of 16 electrode signals. Finally, the visualizations demonstrate that BrainGridNet learns discriminative features and identifies critical brain regions and frequency bands corresponding to each MI class. The convergence of BrainGridNet's strong feature extraction capability, high decoding accuracy, steady decoding efficacy, and low computational costs renders it an appealing choice for facilitating the development of BCIs.

STaRNet: A spatio-temporal and Riemannian network for high-performance motor imagery decoding.

Brain-computer interfaces (BCIs), representing a transformative form of human-computer interaction, empower users to interact directly with external environments through brain signals. In response to the demands for high accuracy, robustness, and end-to-end capabilities within BCIs based on motor imagery (MI), this paper introduces STaRNet, a novel model that integrates multi-scale spatio-temporal convolutional neural networks (CNNs) with Riemannian geometry. Initially, STaRNet integrates a multi-scale spatio-temporal feature extraction module that captures both global and local features, facilitating the construction of Riemannian manifolds from these comprehensive spatio-temporal features. Subsequently, a matrix logarithm operation transforms the manifold-based features into the tangent space, followed by a dense layer for classification. Without preprocessing, STaRNet surpasses state-of-the-art (SOTA) models by achieving an average decoding accuracy of 83.29% and a kappa value of 0.777 on the BCI Competition IV 2a dataset, and 95.45% accuracy with a kappa value of 0.939 on the High Gamma Dataset. Additionally, a comparative analysis between STaRNet and several SOTA models, focusing on the most challenging subjects from both datasets, highlights exceptional robustness of STaRNet. Finally, the visualizations of learned frequency bands demonstrate that temporal convolutions have learned MI-related frequency bands, and the t-SNE analyses of features across multiple layers of STaRNet exhibit strong feature extraction capabilities. We believe that the accurate, robust, and end-to-end capabilities of the STaRNet will facilitate the advancement of BCIs.

[Activation of mTOR in maldeveloped balloon cells and dysmorphic neurons of type II focal cortical dysplasia].

OBJECTIVE: To investigate whether mammalian target of rapamycin (mTOR) kinase was abnormally activated in maldeveloped balloon cells and dysmorphic neurons of focal cortical dysplasia (FCD) with refractory epilepsy. METHODS: A total of 12 archival cases of FCD typeIIwith medically intractable epilepsy treated between 2008 and 2010 were retrieved. Perilesional brain tissue was used as control specimens (n = 8). The expression of phosphorylated p-AKT (Ser473), p-mTOR (Ser2448) and p-P70S6K (Thr389) was investigated by imunocytochemistry. RESULTS: The expression of p-AKT (Ser473), p-mTOR (Ser2448) and p-P70S6K (Thr389) was found in meldeveloped balloon cells and dysmorphic neurons of FCD. A weak stain in a small amount of pyramid neurons was also found in the control group. CONCLUSION: Abnormal activation of mTOR in maldeveloped balloon cells and dysmorphic neurons of FCD may be a key molecular mechanism underlying the histological changes and repeated seizures.

Expression of S100A9 in adamantinomatous craniopharyngioma and its association with wet keratin formation.

Wet keratin is a hallmark of adamantinomatous craniopharyngioma (ACP), which is frequently infiltrated by inflammatory cells. S100 calcium-binding protein A9 (S100A9) has been confirmed to play a decisive role in the development of inflammation. However, the relationship between wet keratin (keratin nodules) and S100A9 in ACP is poorly understood. The objective of the present study was to explore the expression of S100A9 in ACP and its association with wet keratin formation. Immunohistochemistry and immunofluorescence were used to detect the expression of S100A9, ß-catenin and Ki67 in 46 cases of ACP. A total of three online databases were used to analyze S100A9 gene expression and protein data. The results revealed that S100A9 was primarily expressed in wet keratin and some intratumoral and peritumoral cells, and its expression in wet keratin was upregulated in the high inflammation group (P=1.800x10-3). In addition, S100A9 was correlated with the degree of inflammation (r=0.6; P=7.412x10-3) and the percentage of Ki67-positive cells (r=0.37; P=1.000x10-2). In addition, a significant correlation was noted between the area of wet keratin and the degree of inflammation (r=0.51; P=2.500x10-4). In conclusion, the present study showed that S100A9 was upregulated in ACP and may be closely associated with wet keratin formation and the infiltration of inflammatory cells in ACP.

Effects of Vanadium Microalloying and Intercritical Annealing on Yield Strength-Ductility Trade-Offs of Medium-Manganese Steels.

In this paper, we investigate the effects of vanadium on the strength and ductility of medium-manganese steels by analyzing the microstructural evolution and strain hardening rates and performing quantitative calculations. Two significantly different contents of vanadium, 0.05 and 0.5 wt.%, were independently added to model steel (0.12C-10Mn) and annealed at different intercritical temperatures. The results show that higher vanadium addition increases the yield strength but decreases the ductility. The maximum yield strength can increase from 849 MPa to 1063 MPa at low temperatures. The model calculations reveal that this is due to a precipitation strengthening increment of up to 148 MPa and a dislocation strengthening increment of 50 MPa caused by a higher quantity of V4C3 precipitates. However, the high density of vanadium carbides leads them to easily segregate at grain boundaries or phase interfaces, which prevents strain from uniformly distributing throughout the phases. This results in stress concentrations which cause a high strain hardening rate in the early stages of loading and a delayed transformation-induced plasticity (TRIP) effect. Additionally, the precipitates decrease the austenite proportion and its carbon concentrations, rendering the TRIP effect unsustainable. Accordingly, the ductility of high vanadium steels is relatively low.

Automatic and label-free detection of meningioma in dura mater using the combination of multiphoton microscopy and image analysis.

Significance: To prevent meningioma recurrence, it is necessary to detect and remove all corresponding tumors intraoperatively, including those in the adjacent dura mater. Aim: Currently, the removal of meningiomas from the dura mater depends solely on cautious visual identification of lesions by a neurosurgeon. Inspired by the requirements for resection, we propose multiphoton microscopy (MPM) based on two-photon-excited fluorescence and second-harmonic generation as a histopathological diagnostic paradigm to assist neurosurgeons in achieving precise and complete resection. Approach: Seven fresh normal human dura mater samples and 10 meningioma-infiltrated dura mater samples, collected from 10 patients with meningioma, were acquired for this study. First, multi-channel mode and lambda mode detection were utilized in the MPM to characterize the architectural and spectral features of normal and meningioma-infiltrated dura mater, respectively. Three imaging algorithms were then employed to quantify the architectural differences between the normal and meningioma-infiltrated dura mater through calculations of the collagen content, orientation, and alignment. Finally, MPM was combined with another custom-developed imaging algorithm to locate the meningioma within the dura mater and further delineate the tumor boundary. Results: MPM not only detected meningioma cells in the dura mater but also revealed the morphological and spectral differences between normal and meningioma-infiltrated dura mater, providing quantitative information. Furthermore, combined with a self-developed image-processing algorithm, the precise borders of meningiomas in the dura mater could be accurately delineated. Conclusions: MPM can automatically detect meningiomas in the dura mater label-free. With the development of advanced multiphoton endoscopy, MPM combined with image analysis can provide decision-making support for histopathological diagnosis, as well as offer neurosurgeons more precise intraoperative resection guidance for meningiomas.

Synergistic Ion-Anchoring Passivation for Perovskite Solar Cells with Efficiency Exceeding 24% and Ultra-Ambient Stability.

The high-density defect states existing at the grain boundaries and heterojunction interfaces induce nonradiative charge recombination and ion migration processes within perovskite film, which seriously impair the device efficiency and stability. Here, we propose a novel synergistic ion-anchoring passivation (SIP) strategy for high-performance perovskite solar cells, by designing a multifunctional molecule to heal the charged defects via electrostatic interactions. The anion and cation species of the multifunctional molecule are rationally screened via high-throughput DFT simulation and experimental verification, which act as efficient surface passivation agents to heal the lead- and iodine-related defects. As a result, the defect-less perovskite films deliver encouraging device power conversion efficiency >24% with negligible hysteresis. A remarkable open-circuit voltage (Voc) of 1.17 V was obtained with a Voc deficit of 370 mV, featuring the outstanding defect-passivation capability of the SIP strategy. Moreover, the SIP-treated devices show exceptional ambient stability and maintain 70% of the initial efficiency after 150 h of high humidity exposure (relative humidity 70%-80%). Our results highlight the importance of the rational design of passivation agents to realize high-performance perovskite electronics.