Sections Of Specimens Research Articles

A three miRNAs panel in paraffin tissue serves as tool for predicting prognosis of renal cell carcinoma.

Renal cell carcinoma (RCC) stands as the most prevalent form of urogenital cancer. However, there is currently no universally accepted method for predicting the prognosis of RCC. MiRNA holds great potential as a prognostic biomarker for RCC. A total of 100 cases with complete paraffin specimens and over 5-year follow-up data meeting the requirements were collected. Utilizing the clinical information and follow-up data of the specimens, an information model was developed. The expression levels of eight microRNAs were identified using RT-qPCR. Finally, determine and analyze the clinical application value of these microRNAs as prognostic markers for RCC. Significant differences were observed in the expression of two types of miRNAs (miR-378a-5p, miR-23a-5p) in RCC tissue, and three types of miRNAs (miR-378a-5p, miR-642a-5p, miR-23a-5p) were found to be linked to the prognosis of RCC. Establish biomarker combinations of miR-378a-5p, miR-642a-5p, and miR-23a-5p to evaluate RCC prognosis. The combination of three microRNA groups (miR-378a-5p, miR-642a-5p, and miR-23a-5p) identified in paraffin section specimens of RCC in this study holds significant potential as biomarkers for assessing RCC prognosis.

Continuous specimen cooling during slicing and thickness measurement contributes to improved accuracy in image analysis of pathologic specimens.

Sections were prepared from a paraffin-only block and formalin-fixed paraffin-embedded (FFPE) blocks containing fish sausage and human liver specimens. The ST was compared between the sections prepared with cooling using an ice pack (IP) or a continuous cooling device (CCD) paired with a sliding microtome set at an ST of 4 µm. The sections were stained with eosin or aniline blue, and the association between the percent area of positive staining and ST was determined using computer-aided analysis of images captured with a whole slide scanner. The average STs of the paraffin-only block sections measured by four practitioners were 5.01-5.41 and 4.09-4.33 µm in samples prepared using an IP and a CCD, respectively. Therefore, subsequent analyses included sections prepared using the CCD. The ST of the tissue surface was significantly thinner than that of the paraffin surrounding the tissue section. Furthermore, the percent areas of positive staining for eosin and aniline blue were significantly correlated with ST in both the fish sausage and liver sections. The analysis of the ST and percent area of positive staining in 60 sections of the same block, which were categorized into quantiles based on ST, revealed a significant difference in the percent area of positive staining between the thicker and thinner sections. Specimen sectioning should be performed with a CCD, ST should be measured before the staining of pathologic specimens prepared for quantitative analysis, and histologic examination should be performed using specimens with uniform ST.

The effect of deviations in sintering temperature on the translucency and color of multi-layered zirconia

ObjectThis study aimed to investigate the changes in the translucency and color of four different multi-layered zirconia materials when the sintering temperature were inaccurate.Materials and methodsTwo hundred zirconia samples (11 × 11 × 1.0 mm) of four multi-layered zirconia, Upcera TT-GT (UG), Upcera TT-ML (UM), Cercon xt ML (CX), and Lava Esthetic (LE), were divided into five subgroups according to the sintering temperature: L1 (5% lower temperature), L2 (2.5% lower temperature), R (recommended sintering temperature), H2 (2.5% higher temperature), H1 (5% higher temperature). After sintering, color coordinates were measured. Then the translucency parameter (TP) values, and the color differences (between the inaccurate sintering temperature and the recommended temperature) of each zirconia specimen were calculated. Statistical analysis was performed by using three-way ANOVA tests, the one-way ANOVA, and Tukey’s post hoc test.ResultsThree-way ANOVA results showed that material type, sintering temperature, specimen section, and their interactions significantly influenced the TP values (except for the interactions of specimen section and sintering temperature) (P < .05). TP values of zirconia specimens were significantly different in the inaccurate sintering temperatures (P < .05), except for the cervical and body sections of UG group (P > .05). Compared with recommended sintering temperature, higher sintering temperature caused higher TP values for CX, but lower for LE. Three-way ANOVA results showed that material type, sintering temperature, and their interactions significantly influenced the ∆E00 values (P < .05). There were no significant differences in ∆E00 values of UM and CX groups at different inaccurate sintering temperatures, and were clinical imperception (except for UM-L1) (∆E00 < 1.25). ∆E00 values of all zirconia specimens showed clinically acceptable (∆E00 < 2.23).ConclusionThe deviations in sintering temperature significantly influenced the translucency and color of tested multi-layered zirconia. The trends of translucency in the multi-layered zirconia depended on material type and the color changes of all zirconia materials were clinically acceptable at inaccurate sintering temperatures.

The last giants: New evidence for giant Late Triassic (Rhaetian) ichthyosaurs from the UK.

Giant ichthyosaurs with body length estimates exceeding 20 m were present in the latest Triassic of the UK. Here we report on the discovery of a second surangular from the lower jaw of a giant ichthyosaur from Somerset, UK. The new find is comparable in size and morphology to a specimen from Lilstock, Somerset, described in 2018, but it is more complete and better preserved. Both finds are from the uppermost Triassic Westbury Mudstone Formation (Rhaetian), but the new specimen comes from Blue Anchor, approximately 10 km west along the coast from Lilstock. The more complete surangular would have been >2 m long, from an individual with a body length estimated at ~25 m. The identification of two specimens with the same unique morphology and from the same geologic age and geographic location warrants the erection of a new genus and species, Ichthyotitan severnensis gen. et sp. nov. Thin sections of the new specimen revealed the same histological features already observed in similar giant ichthyosaurian specimens. Our data also supports the previous suggestion of an atypical osteogenesis in the lower jaws of giant ichthyosaurs. The geological age and giant size of the specimens suggest shastasaurid affinities, but the material is too incomplete for a definitive referral. Ichthyotitan severnensis gen. et sp. nov., is the first-named giant ichthyosaur from the Rhaetian and probably represents the largest marine reptile formally described.

Effects of Impurities and Additives on Interactions of Nuclear-Grade Graphite with Molten LiF-NaF-KF

It has been widely acknowledged that the presence of impurities in molten fluoride salt can alter the salt/material interactions. However, the effects of various impurities such as oxides, metal fluorides, reducing impurities, etc., on the behavior of nuclear-grade graphite in molten fluoride salts have not been reported. This study focuses on understanding the effects of various oxidizing and reducing impurities on the wetting and infiltration behavior of molten FLiNaK salt for nuclear-grade IG-110 graphite. Our results suggest that different impurities can cause different effects on nuclear graphite–molten salt interactions, with some impurities leading to significant degradation of the graphite. Our results demonstrate that certain impurities, such as Cr2O3 and CrF3, lead to a limited increase in wetting and infiltration of molten salt into nuclear graphite, while impurities such as Li2O lead to significantly increased wetting and infiltration throughout the cross section of the graphite specimen. Certain impurities, such as Li, can also lead to significant degradation of the graphite in the salt, with the extent of degradation increasing with the increase in the quantity of Li added. Our results also demonstrate that firing of IG-110 graphite at 900°C under a reducing atmosphere made the graphite surface resistant to wetting by molten FLiNaK salt, as compared to the nonfired sample.

Abstract 5573: Loss of glutathione S-transferase omega 2 promotes immunosuppressive tumor microenvironment by the induction of PD-L1 expression in lung adenocarcinoma

Abstract Glutathione S-transferase omega 2 (GSTO2) is known as one of important regulators for the glutathione redox balance. We recently reported that GSTO2 is exclusively expressed in airway basal cells, Clara cells, and type II alveolar cells, which have self-renewal capacity in the lungs; however, its expression was completely lost in lung squamous cell carcinoma (LSCC) (Cancer Science, 2022). In this study, we examined the expression of GSTO2 in lung adenocarcinoma (LAC), another type of lung cancer, and analyzed the relationship between GSTO2 expression and clinicopathological features. We enrolled 139 patients who were diagnosed with LAC and underwent surgery, and immunohistochemically evaluated the expression of GSTO2 using formalin-fixed, paraffin-embedded sections of surgical specimens. Fifty eight of 139 lung adenocarcinoma samples exhibited GSTO2 expression, while remaining 81 cases did not. The expression of GSTO2 in LAC samples was significantly associated with never or light (Brinkman Index &amp;lt; 400) smoking history (P=0.0027) and histological subtypes (lepidic 77%; acinar 44%; papillary 22%; micropapillary 16.7%; solid 9.6%; P&amp;lt;0.0001). There were no significant differences between the groups with respect to pN, pM, EGFR mutation, ALK fusion, and ROS-1 fusion. However, GSTO2 expression in LAC significantly associated with pT1 (P&amp;lt;0.0001), early stage (P&amp;lt;0.0001), and absence of PD-L1 expression (P=0.0027). Moreover, patients with GSTO2-negative LAC had a significantly lower disease-free survival rate than those with GSTO2-positve LAC (P=0.028). To examine whether GSTO2 expression affects PD-L1 expression, we prepared GSTO2-transfected and mock-transfected lung adenocarcinoma cell lines (A549 and PC-9). In both cell lines, mRNA level of PD-L1 was significantly reduced in GSTO2-transfectants. Because Jang RH et al reported that vimentin, reflecting to acquire mesenchymal traits in epithelial-mesenchymal transition (EMT), regulates the PD-L1 expression, we next examined whether GSTO2 overexpression affects the expression of EMT related molecules. There was no difference in a mRNA level of E-cadherin, while the mRNA expression of vimentin and SLUG, a transcriptional inducer of EMT, were significantly suppressed in GSTO2-transfected PC-9. In both cell lines, protein expression of vimentin was also significantly reduced in GSTO2-transfectants. The present study shed light on a novel function of GSTO2 as a PD-L1 regulator, which may contribute to prevention of tumor immune escape. Citation Format: Ryusuke Sumiya, Hiroto Hatano, Teruki Hagiwara, Satoshi Nagasaka, Kazuhiko Yamada, Norihiro Kokudo, Hiromu Suzuki, Yuki I. Kawamura. Loss of glutathione S-transferase omega 2 promotes immunosuppressive tumor microenvironment by the induction of PD-L1 expression in lung adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5573.

Creep Performance Study of Inconel 740H Weldment Based on Microstructural Deformation Mechanisms

Abstract The creep behavior of Inconel 740H weldment at the temperature of 760 °C is investigated experimentally and analytically using the deformation-mechanism-based true stress (DMTS) model. The Inconel 740H weldment specimens are prepared with the gas tungsten arc welding technique. Creep testing is performed on the Inconel 740H weldment specimens under a range of stress levels from 190 MPa to 447 MPa at the temperature of 760 °C. The DMTS model is employed to analyze the creep curves and creep rates. The model parameters for Inconel 740H weldment are determined from the analyses of the creep testing data in combination with that from the previous studies of similar materials based on the same creep mechanisms that involve grain boundary sliding and intragranular dislocation climb-plus-glide with dislocation multiplication. The creep life predictions of the DMTS model for Inconel 740H weldment agree very well with creep rupture test data within a temperature range of 700–800 °C. The fractured surfaces and longitudinal sections of creep-tested Inconel 740H weldment specimens are examined using scanning electron microscopy, which corroborates the DMTS model inference that the creep failure of Inconel 740H weldment is in a mode of predominantly intergranular fracture. The present study suggests that grain boundary sliding is the most significant controlling factor for the creep failure of Inconel 740H weldment.

Mechanical properties of Hastelloy X produced by laser powder bed fusion and affected by spatter redeposition

Defects in materials manufactured via laser powder bed fusion challenge this manufacturing process' dependability and may prevent it from being comprehensively used for structural components, particularly those intended to operate under dynamic loading conditions. This study aims to investigate the effect of spatter-driven lack of fusion on the mechanical properties of Hastelloy X, with a particular focus on fatigue performance. Mechanical test specimens were manufactured in two builds with different build rates and monitored through in-situ optical tomography. The images acquired in situ were analyzed to detect spatter redeposits to predict the defect content in the gauge section. Selected specimens were measured ex-situ using X-ray computed tomography to map the defect populations. Afterward, the specimens were tensile and fatigue tested, and their performance was analyzed based on the measured and expected defect populations. It was confirmed that a higher build rate is associated with more extensive detection of spatter redeposits in optical tomography images and lack of fusion defects. The fatigue lives of specimens manufactured at higher build rates presented higher scatter but significantly higher average, despite the more critical defect population. Surprisingly, the confirmed presence of lack of fusion defects in the gauge section of test specimens did not necessarily result in a poorer fatigue performance. It was concluded that the grain refinement obtained through the increase in nominal layer thickness has a life-prolonging effect that overrides the effects of spatter-induced lack of fusion defects.

Research on the Erosion of Gun Barrel Based on Vented Vessel Tests

The vented vessel test, as an alternation of the firing practice, is implemented to reconstruct the deterioration process of the gun barrel suffering the thermochemical erosion by propellant combustion gas. High pressure of over 300 MPa with a duration exceeding 20 ms is applied on the rifled specimen. A phase transition layer about 136 μm is observed by scanning electron microscopy (SEM) from the cross section of the test specimen. Some residual oxidation products of the iron can be detected by energy dispersive x-ray spectroscopy (EDS) on parts of the inner surface. A comprehensive erosion analysis is conducted, which estimates that the mass loss of the specimen is mainly attributed to the periodical formation and peeling of the chemical reaction layer on the bore surface. The most severely eroded part is located on the corner of the land. On the basis of the examined erosion mechanisms, a proper thermochemical erosion model is employed. The mass dissipation and the geometry evolution under continuous firing are simulated using finite element method (FEM). The simulation phenomenon shows good consistency with results of the experimental tests.

Differentiating Between Epstein-Barr Virus-positive Lymphoid Neoplasm Relapse and Post-transplant Lymphoproliferative Disorder After Sex-mismatched Hematopoietic Stem Cell Transplantation.

After allogeneic hematopoietic stem cell transplantation (HSCT), accurate differentiation between donor-derived post-transplant lymphoproliferative disorder (PTLD) and relapse of recipient-derived lymphoproliferative disorder (LPD) is crucial for determining treatment. Conventional diagnostic approaches for PTLD include histopathological examination, flow cytometry, and chimerism analysis of bulk tumor tissue. However, these methods are inconclusive in cases in which the primary disease is an Epstein-Barr virus (EBV)-positive LPD and is of the same lineage as that of the post-HSCT LPD tumor cells. Particularly, in cases where the number of tumor cells in the tissue is low, it is difficult to determine the origin of tumor cells. In this study, we developed a new method to simultaneously detect signals using sex chromosome fluorescence in situ hybridization, immunofluorescence staining, and EBV-encoded small RNA in situ hybridization on a single section of formalin-fixed paraffin-embedded histopathological specimen. The utility of the method was validated using specimens from 6 cases of EBV-positive LPD after sex-mismatched HSCT that were previously difficult to diagnose, including Hodgkin lymphoma-like PTLD that developed after HSCT for Hodgkin lymphoma and recurrence of chronic active EBV infection. This method successfully preserved the histologic structure after staining and allowed accurate determination of tumor cell origin and lineage at the single-cell level, providing a definitive diagnosis in all cases. This method provides a powerful tool for the diagnosis of LPDs after sex-mismatched HSCT.

Experimental programme on austenitic stainless steel RHS members subjected to monotonic and cyclic bending

Stainless steel is a corrosion resistant iron alloy with great potential in structural engineering due to its excellent mechanical features, durability and aesthetic properties. Since most of the existing research has concerned the behaviour of the material, the response of individual structural members, or the performance of simple structural systems under monotonic loading, one of the challenges that remains is the evaluation of the cyclic performance of members to promote its use in seismic design and exploit the excellent ductility and strain hardening properties of this material. For this reason, an experimental programme on austenitic stainless steel Rectangular Hollow Section (RHS) specimens was carried out at the Department of Civil Engineering of the Università degli Studi di Salerno in collaboration with the Universitat Politècnica de Catalunya. A total of eight RHS specimens were tested around the minor axis under both monotonic (three specimens) and cyclic (five specimens) loading, in an experimental set-up that followed a cantilever scheme. The main purpose of this study was to acquire information on the cyclic performance of austenitic steel structural members, focusing on the comparison between monotonic and cyclic behaviours. The outcomes of the tests included the load–displacement and the moment–rotation curves, the energy dissipation capacity, and the evaluation of the key rotation capacities of the members. The reported data are essential to enhance the still scarce research on the seismic behaviour of stainless steel structures.

An investigation on the toughening behavior and morphology of acrylonitrile butadiene styrene/polybutylene terephthalate blends reinforced by carbon nanotubes

Acrylonitrile butadiene styrene (ABS) and polybutylene terephthalate (PBT) polymers are widely exploited polymers in the plastics industry. In this research, PBT polymer is added into ABS polymer as a second phase due to its good fluidity and some superior mechanical characteristics. Carbon nanotubes (CNTs) are added as a reinforcement into the ABS/PBT polymer blend (80/20). Standard samples of mechanical tests including tensile, flexural, and impact were made by injection molding and standard samples of fracture tests were made by hot press method. The essential work of fracture (EWF) method was used to check fracture toughness. The presence of PBT into ABS improved its tensile and flexural strength while it diminished the impact strength and fracture toughness of ABS. The addition of carbon nanotubes into ABS/PBT blends increased its tensile and flexural strength, impact resistance as well as fracture toughness. The results of microscopic tests demonstrate a relatively uniform distribution of carbon nanotubes in the polymer blend. In addition, the morphological observations illustrate a rather proper adhesion between carbon nanotubes and the polymeric matrix. As importantly, investigations on the fractured sections of fracture specimens revealed that the nanocomposites containing CNTs have a tendency toward a ductile failure in comparison with ABS/PBT polymer blend.

Experimental and numerical study on the load-bearing capacity of cold-formed stiffened high-strength steel box columns

This paper reports a comprehensive experimental and numerical study on the load-bearing capacity of cold-formed stiffened high-strength steel box columns. A novel cold-formed stiffened section for box columns with width-to-thickness ratios exceeding design limits was presented. Column buckling tests were conducted, including precise measurements of initial geometric imperfections, material property tests, and axial compression tests. The results revealed that the stability factors of the stiffened specimens consistently surpassed those of the corresponding box section specimens within the same experimental group, with an average increase ratio of 19.9%. Finite element models were developed, validated, and used for parametric studies, considering variations in width-to-thickness ratios, slenderness ratios, and steel strengths. A total of 144 finite element models were analyzed to comprehensively investigate the effects of the selected parameters. The obtained parameter analysis results were compared with calculation methods and design codes, such as GB 50017–2017, EN 1993-1-1, ANSI/AISC 360–16, and AISI S100-16, to investigate their applicability. The Direct Strength Method (DSM) was found to overestimate the bearing capacity of these columns. Therefore, a modified DSM was proposed specifically for predicting the ultimate strength of cold-formed stiffened high-strength steel box columns. Extensive verification confirmed that the design strengths obtained using the modified DSM provide accurate and reliable predictions for the behavior of these columns.

Through‐thickness tensile characterization and analysis of fiber‐reinforced polymer composites using digital image correlation and finite element modeling

AbstractDigital image correlation (DIC) and finite element analysis (FEA) are used to assess the cylindrical spool‐shaped ASTM D7291 and I‐beam‐shaped specimens for through‐thickness (TT) mechanical characterization of thick (~25 mm) fiber reinforced polymer matrix composites. The composites are made of E‐glass woven fabrics reinforcing a vinyl ester matrix. DIC full‐field measurements and FEA showed a rather uniform strain distribution within the gage section of the ASTM D7291 specimen. However, strain concentrations are revealed at the bondlines between the end‐tabs and the test specimen, in addition to strain gradients at the curved section of the specimen. DIC‐measured and FEA‐predicted strain fields of the I‐beam specimens exhibited a region of uniform strain distribution within the gage section larger than that of the ASTM D7291 specimen. Nevertheless, high stress concentrations at the fillet (curved flange‐to‐web transition) regions and some amount of web bending occur in the I‐beam specimen. Beyond providing the TT mechanical properties of the E‐glass woven/vinyl ester composites, the current work discusses advantages and caveats of both promising specimens, providing quantifications of stress concentration factors and length of zones were strains and stresses may be considered uniform.Highlights Stress/strain distributions of through‐thickness tensile specimens are evaluated. The main drawback of the spool‐shaped specimen is adhesive failure. The modified I‐beam specimen shows acceptable stress concentration factors. The modified I‐beam is adequate for strength and Poisson ratio characterization. I‐beam specimens are easier to manufacture and do not require adhesive joints.

Enhancing diagnosis of Hirschsprung’s disease using deep learning from histological sections of post pull-through specimens: preliminary results

PurposeAccurate histological diagnosis in Hirschsprung disease (HD) is challenging, due to its complexity and potential for errors. In this study, we present an artificial intelligence (AI)-based method designed to identify ganglionic cells and hypertrophic nerves in HD histology.MethodsFormalin-fixed samples were used and an expert pathologist and a surgeon annotated these slides on a web-based platform, identifying ganglionic cells and nerves. Images were partitioned into square sections, augmented through data manipulation techniques and used to develop two distinct U-net models: one for detecting ganglionic cells and normal nerves; the other to recognise hypertrophic nerves.ResultsThe study included 108 annotated samples, resulting in 19,600 images after data augmentation and manually segmentation. Subsequently, 17,655 slides without target elements were excluded. The algorithm was trained using 1945 slides (930 for model 1 and 1015 for model 2) with 1556 slides used for training the supervised network and 389 for validation. The accuracy of model 1 was found to be 92.32%, while model 2 achieved an accuracy of 91.5%.ConclusionThe AI-based U-net technique demonstrates robustness in detecting ganglion cells and nerves in HD. The deep learning approach has the potential to standardise and streamline HD diagnosis, benefiting patients and aiding in training of pathologists.

Limit load of notched Ti-6Al-4V specimens under axial fatigue

Ti-6Al-4V is used to manufacture aircraft components, that are subjected to fatigue loads during their service life. These components exhibit flaws and are susceptible to impact damage. Therefore, it is important to study the fatigue behaviour of Ti-6Al-4V in the presence of defects to accurately evaluate the fatigue life of components. This paper reports the limit load of notched Ti-6Al-4V specimens not subjected to solution treatment and over-aging under axial fatigue. The tests are carried out in inert environments using a step loading procedure, with a load ratio R = 0. The limit loads of the specimens with a notch depth / width of the specimens’ gauge section ratio d / D = 0.0439 and d / D = 0.0877 are similar and higher than the limit load of the specimen with d / D = 0.1754 since the net area at the minimum cross section of the third specimen is much smaller than the areas of the other two specimens. The nominal stress at failure referred to the net area is similar for the fatigued specimens.

Evaluation of the predictive effect of PD-L1 expression on survival in early triple-negative breast cancer

Objectives: To find the prognostic factors related to early triple-negative breast cancer to optimize the therapeutic strategies, and explore the influence of programmed cell death ligand-1(PD-L1)expression in early triple-negative breast cancer on its prognosis, so as to provide support for clinical treatment decisions. Methods: Early triple-negative breast cancer patients treated at the National Cancer Center, National Clinical Research Center for Cancer, Cancer Hospital, Chinese Academy of Medical Sciences during 1st June, 2009 and 31st Oct, 2015 were enrolled in this study. All the clinicopathological data of patients were collected, and the paraffin sections of the surgical specimens were stained with estrogen receptor, progesterone receptor, human epidermal growth factor receptor-2, secreted protein acidic and rich in cysteine (SPARC), androgen receptor, PD-L1 and other antibodies by the immunohistochemical method. Kaplan-Meier survival and Cox regression curves were used for survival analysis of relevant clinical and pathological results and nomogram survival prediction models were established to explore the influence of relevant factors on the prognosis. Results: A total of 205 patients with triple-negative breast cancer were enrolled. Ninety patients (43.9%) were PD-L1 positive. The median follow-up time was 63 months. Thirty-seven patients were relapsed or recurrent and 16 patients were dead. The 5-year disease-free survival (DFS) rate and overall survival (OS) rate were 86.1% (95% CI: 81.4%-90.8%) and 93.6% (95% CI: 91.0%-97.6%), respectively, in the general population. Univariate Cox regression analysis showed that PD-L1 expression and lymph node metastasis were correlated with DFS and OS (P<0.05). In multivariate analysis, PD-L1 expression was an independent influencing factor of DFS, with PD-L1 positive patients possessing a significant survival benefit in DFS (HR=0.31, 95% CI: 0.13-0.73). Lymph node metastasis was an independent influencing factor of OS, and OS was significantly shortened in patients with positive lymph node metastasis (HR=3.24, 95% CI: 1.15-9.17). PD-L1, lymph node metastasis, menopausal status, Ki-67 index and adjuvant chemotherapy regimen were included to establish the 1- and 3-year DFS and OS nomogram prediction models, resulting in C indices of 0.698 and 0.748, respectively. Conclusions: PD-L1 expression is a predictive biomarker of good prognostic factor in triple-negative breast cancer patients. DFS is significantly prolonged in PD-L1 positive patients and OS also shows a prolongation trend. The nomogram prognosis prediction models have reference values for adjuvant chemotherapy in this patient group.

Behaviour of T-shaped stiffened concrete-filled steel tubular stub columns after uniform and non-uniform fire exposure

The post-fire behaviour of T-shaped stiffened concrete-filled steel tubular stub columns was investigated by the heating and residual mechanical performance tests. Key parameters, such as heating duration, number of surfaces exposed to fire and the influence of the stiffening steel bars, were studied. Temperature distribution, failure modes, mid-height strain curves, and load-displacement curves were obtained and discussed. The study reveals that the number of fire-exposure surfaces significantly affects the temperature distribution of the specimen section. Both the bearing capacity and compressive stiffness decrease with the increase of fire exposure surfaces and heating time, whereas the ductility follows an inverse pattern. The transverse stiffeners can enhance the mechanical performance of these stub columns, especially for ductility.

Development and validation of a deep learning model for improving detection of nonmelanoma skin cancers treated with Mohs micrographic surgery

BackgroundReal-time review of frozen sections underpins the quality of Mohs surgery. There is an unmet need for low-cost techniques that can improve Mohs surgery by reliably corroborating cancerous regions of interest and surgical margin proximity. ObjectiveTo test that deep learning models can identify non-melanoma skin cancer (NMSC) regions in Mohs frozen section specimens. MethodsDeep learning models were developed on archival images of focused-microscopic views (FMV) containing regions of annotated, invasive NMSC between 2015 and 2018, then validated on prospectively collected images in a temporal cohort (2019-2021). ResultsThe tile-based classification models were derived using 1,423 FMV images from 154 patients and tested on 374 images from 66 patients. The best models detected basal cell carcinomas with a median average precision of 0.966 and median area under the receiver operating curve of 0.889 at 100x magnification (0.943 and 0.922 at 40x magnification). For invasive squamous cell carcinomas, high median average precision of 0.904 was achieved at 100x magnification. LimitationsSingle institution study with limited cases of SCC and rare NMSC. ConclusionDeep learning appears highly accurate for detecting skin cancers in Mohs frozen sections, supporting its potential for enhancing surgical margin control and increasing operational efficiency.

Experimental and numerical investigation on cold-formed steel zed section beams with complex edge stiffeners

This paper describes the experimental and numerical investigation on the flexural performance of cold-formed steel (CFS) zed section members bent about the neutral axis parallel to the flanges. In the test program, twelve pairs of zed section specimens fabricated from steel sheets of grades G450, G500 and G550 were loaded under four-point bending. Three series of sectional shapes, namely the zed sections with plain flanges as well as complex edge stiffeners consisting of double-fold inward and outward return lips, were devised for the test specimens. In the numerical investigation, the finite element model of four-point bending members, which was developed using ABAQUS and calibrated against the experimental results, was adopted to predict the behaviour of CFS unstiffened and edge-stiffened zed section beams over wide ranges of flange-to-web width ratio, lip-to-flange width ratio, return lip-to-lip width ratio and cross-sectional compactness. Furthermore, underpinned by the bending capacities acquired from the 12 experiments and 222 FE analyses in this study as well as 22 tests available in the literature, it was demonstrated that the current direct strength method (DSM) codified in the AISI S100 generally provided conservative flexural strength predictions for the unstiffened zed section members, while led to overall slightly unconservative design for the edge-stiffened zed section beams. In addition, based upon the DSM-based approaches that were addressed in the previous studies to account for the effect of local-distortional interaction, the nominal flexural strengths of the CFS zed section members with simple and complex edge stiffeners were found to be underestimated by 17% to 21% on average. Accordingly, the modified DSM formulae were recommended in this study for the CFS unstiffened and edge-stiffened zed section beams bent about the neutral axis parallel to the flanges.