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In impact crater lakes, the lacustrine sedimentary records may not solely reflect climatic changes but also potential erosional effects from lithologically distinct impactite formations. The hydrochemical and biogeochemical processes during the deposition of the Nördlinger Ries impact crater lake, which fall in the range of the mid-Miocene Climate Transition, were studied by analysing microcrystalline authigenic carbonates in a drill core succession, using stable oxygen and carbon isotopes in conjunction with biomarkers. These investigations revealed an early sulfidic interval characterized by thiophenes, iso- and anteiso-C 15:0 acids derived from sulfate reducing bacteria, and dolomites with low to intermediate δ13C carb values. The subsequent distinctive interval is characterized by extremely 13C-enriched dolomite (δ13C carb up to +20.93 ± 0.05‰ V-PDB), decline of iso- and anteiso-C 15:0 acids and is rich in an Archaea-derived archaeol that is 13C-enriched (−14.7‰), indicating extensive methanogenesis in sulfate-depleted lake porewater during early diagenesis. The sulfate decline results from successive sulfate reduction when replenishment by sulfate-bearing inflow water is limited. The carbonates exhibit enriched 18O due to pronounced evaporation in a long-resided water body and enriched 13C by methanogenesis. A change in provenance of water derived from the sulfur-rich suevite (impact melt-bearing breccia) and crystalline source rocks to the sulfur-poor Bunte Breccia (continuous ejecta blanket) is required. Intermittently high Si/Al and Zr/Al at the high δ13C interval suggests sporadic short-term runoff increase, leading to fluctuating physiochemical lake conditions. A subsequent decline in both δ13C carb and archaeol indicates a decreasing lake level with intermittent subaerial exposure events, supported by bioturbation and mud cracks. The concomitant lake oxygenation is well supported by increasing Pr/Ph ratios and lipids derived from aerobic methanotrophs (13C-depleted 3-methyl-hopanoids). In the youngest unit, allochthonous lignites and biomarkers from lacustrine/soil sources appear, high total sulphur contents and thiophenes recur, and stable C and O isotope values decrease again. These observations suggest another major provenance change of the inflowing solutes, with increasing influx from weathered pyrite-bearing Jurassic claystones. These findings demonstrate that the climatic record expected from the stable carbon and oxygen isotopes of the Ries carbonates is strongly overprinted by hydrochemical and biogeochemical processes due to changing ion influx from substrate rocks, along the course of the successive ejecta erosion and catchment changes. Such an intrinsic control of lacustrine biogeochemical processes is also expected for other hydrologically closed impact crater lake basins, where catchment rocks with distinctively different lithologies are present. [ABSTRACT FROM AUTHOR]

Medical image segmentation methods based on deep learning show good performance advantages and application prospects, but such methods require experienced medical experts to spend a lot of time labeling data. To address this problem in gland segmentation research, a model named ILECGJL based on incomplete label error correction and group joint learning is proposed, which significantly reduces the dependence on labeled data while ensuring segmentation performance. ILECGJL employs the proposed incomplete label error correction method to capture semantic relationships between labeled and unlabeled images, enhancing the quality of pseudo labels and improving the accuracy of gland segmentation. At the same time, ILECGJL harnesses the proposed group joint learning strategy to enhance the model's robustness on pseudo label noise, further boosting segmentation performance. Experimental results on the CRAG dataset confirm that our proposed label error correction method yields substantial improvements based on initial segmentation predictions. The performance of the ILECGJL model demonstrates significant enhancements compared to fully supervised methods that solely rely on labeled data and outperforms other mainstream semi-supervised approaches. Results and comparisons on the GlaS dataset showcase good generalization ability of the ILECGJL model. Moreover, due to its modular design and customizability, ILECGJL offers high flexibility and can be conveniently integrated into different segmentation models. • Incomplete Label Error Correction and Group Joint Learning model. • A group joint learning strategy for the label error correction. • Gland segmentation on GlaS and CRAG datasets achieves SOTA performance. [ABSTRACT FROM AUTHOR]

• A novel end-to-end two-stage network for the automatic detection of mitosis nuclei in breast cancer is proposed, and it achieves the best performance compared with other methods on the 2012 ICPR MITOSIS Dataset. • An improved residual network backbone is proposed to re-encode features to enhance the ability of the model to detect mitosis nuclei. • A hybrid anchor branch method is proposed to make the network adaptively select the optimal scale, which improves the detection accuracy of the target object. • A novel large-scale mitosis nuclei dataset (GZMH Dataset) with annotations is firstly published by the authors in this paper, and our method achieves the best performance compared with other reproducible methods on this dataset. Mitosis detection is one of the important problems in computational pathology, and mitotic count is an important index of breast cancer grading for pathologists. However, the current count of mitotic nuclei relies on pathologists observing the number of mitotic nuclei in hotspots under a microscope, which is subjective and time-consuming. In this paper, we propose a two-stage cascaded network, named FoCasNet, for mitosis detection. In the first stage, a detection network is proposed to screen as many candidates as possible. In the second stage, a classification network is proposed to refine the results of the first stage. In addition, the attention mechanism, normalization method, and hybrid anchor branch classification subnet are introduced to improve the overall detection performance. Our method achieves the current highest F1-score of 0.888 on the public dataset ICPR 2012. We also evaluated our method on the GZMH dataset released by our research group for the first time and reached the highest F1-score of 0.563, which is also better than the state-of-the-art detection networks. It confirmed the effectiveness and generalization of our method. The code will be available at: https://github.com/antifen/mitosis-nuclei-detection. [ABSTRACT FROM AUTHOR]

Abstract: Unintentional physical human–robot contact is becoming more common as robotic manipulators operate in closer proximity to people. In this paper, we investigate the use of compliant foam covering to reduce impact severity and enhance human safety. An improved analytical impact dynamic model is introduced. The impact model conservatively approximates the impact force and resulting head acceleration; and incorporates the configuration-dependent manipulator dynamics and the coupling between the human head and moving torso. It is applicable to head impacts with impact velocities that do not exceed 1.25m/s. Based on this model, the most important manipulator parameter for reducing the impact severity is the effective mass. Furthermore, the foam stiffness has a greater reduction effect than any of the manipulator parameters. A procedure to properly design the foam in accordance with a force-based or acceleration-based safety criterion and a foam thickness constraint is proposed. The impact model and model-based design procedure are tested experimentally. Impact experiments are performed with an apparatus simulating the human head–neck–torso. The maximum error between the predicted and experimental maximum head acceleration results is less than 7%. [Copyright &y& Elsevier]

Abstract: Extensive lidar measurements of Fe and Na meteor trails were conducted with an integration period of 3.2s. A total of 155 Fe trails and 136 Na trails were registered, respectively, from the 260-h Fe and 320-h Na photon count profiles. They came from the observations that did not coincide with the major meteor showers and thus represent sporadic meteors. The mean input fluxes from the lidar meteor trail measurements are 1.5×105 atomcm−2 s−1 for Fe and 1.4×104 atomcm−2 s−1 for Na. The values might be temperate overestimates of the absolute lower bounds of the mean Na and Fe input fluxes when wind is advecting the metal vapor trails, because strong winds along with small-scale turbulence and shear could distort and dilute the trails, consequently shortening their lifetime. The trail altitude distribution for each metal species differs in details from the corresponding background layer, whereas the centroid height for each trail distribution approaches that of the relevant background layer (∼90.9km for Na trails and 89.1km for Fe trails). Only 8 two-element trails are detected from a total of 210-h simultaneous and common-volume Na and Fe lidar measurements. The observed two-element meteor trails yield the mean Fe/Na abundance ratio of ∼9.0. These trail features suggest a role of differential ablation. [Copyright &y& Elsevier]

Fixtures can maintain stability in the machining of thin-walled parts (TWP), thus avoiding the occurrence of workpiece deformation. The stress at the fixture-workpiece contact interface is a key factor in evaluating the reliability of the fixture's restraint on the TWP. This paper investigates the prediction of icing interface normal stress during TWP milling based on the ice-based fixturing (IBF) previously proposed by the authors of this paper. The principle of the IBF is first explained. The mechanical properties of the ice-workpiece bonding material (IWBM) are then characterized by Dundurs parameters. Afterwards, an analytical model for the prediction of icing interface normal stress under cutting load is developed using the Goursat formula based on the interface continuity conditions of stress and displacement. The finite element method (FEM) is then used to verify the accuracy of the prediction model, and the results show that the average prediction error of the icing interface normal stress is limited to 13.99%. Finally, milling experiments are carried out to verify the validity of the finite element model, and the experimental results show that the simulation errors of the main cutting force and feeding force are limited to 12.35% and 11.47% respectively, and the FEM can greatly simulate the cutting state of the workpiece clamped by IBF. This paper can provide a valuable theoretical and practical basis for the analysis and prediction of stress at the workpiece-fixture contact interface. • The concept of "ice-based fixturing" is proposed to suppress machining deformation of thin-walled parts. • Dundurs parameters are used to characterize the mechanical properties of the icing interface. • An analytical model for the prediction of icing interface normal stresses under cutting loads is developed using the Goursat formula. [ABSTRACT FROM AUTHOR]

• The microscopic morphology of ice with physical crosslinking structure is elucidated. • The variation of stress–strain and time-strain rate of ice with physical crosslinking structure under impact load is analyzed. • The strengthening effect of different crosslinking structures on the mechanical properties of ice is studied. Ice is formed by the crystallization of water. Although ice appears to be less brittle under low strain rates during compression and shearing processes, it is still considered a brittle material, which poses significant challenges for its wide applications in industries. Therefore, the study of the mechanical properties of ice has always been a topic of great interest. This paper investigates the influence of single physical crosslinking structure (PCS) and dual PCS on the microstructure and dynamic mechanical properties of ice. Firstly, a solution with 0.2 wt% of sodium alginate (SA), a solution with 0.2 wt% of hydroxypropyl methyl cellulose (HPMC), and a mixture solution with 0.1 wt% of SA and 0.1 wt% of HPMC are prepared. The molecular chain connection methods in the prepared solutions are then analyzed. Subsequently, the microstructure of ice (Ice, SA-ice, HPMC-ice, SA&HPMC-ice) formed from different solutions is observed by a cryo-scanning electron microscope (Cryo-SEM). Finally, Hopkinson pressure bar (HPB) experiments are carried out to compare and analyze the time-strain rate and stress–strain relationships of different types of ice, thus elucidating the effect of microstructure on the strength of ice. Additionally, the variations in time-strain rate/strain energy and stress–strain curves of SA&HPMC-ice under different launch pressure are analyzed. This study provides valuable reference and guidance for enhancing the mechanical properties of ice and its engineering applications. [ABSTRACT FROM AUTHOR]

Objective: To report our experience of laparoscopic radiofrequency ablation (RFA) on patients with renal tumors. RFA has been increasingly applied in the management of small renal tumors. However, it was performed mostly via percutaneous approach, with limited cases and a short follow-up period. Methods: From February 2006 to March 2008, laparoscopic RFA was performed on 106 renal tumors (size range: 0.9-5.5 cm) in 106 selected patients (74 men and 32 women, age range: 25-81 years). Initial contrast-enhanced computed tomography (CT) examination was performed seven days after the procedure, with subsequent CT assessment at three months, six months, and every six months thereafter. Serum creatinine measurement was conducted along with each time CT examination. Results: The mean follow-up period was 32 months (range: 12-48). All 106 tumors were biopsied before RFA, of which 90 were diagnosed as renal cell carcinoma (RCC) (84.90%). There was one incomplete ablation. One case with radiographic local recurrence was then proved by pathologic analysis of the nephrectomy specimen to have no cancer cells. The local tumor control rate was 98.1% (104/106). Of the 90 RCC cases, the disease-free survival rate was 97.8% (88/90); both the cancer-specific and the overall survival rate were 100%. No death or renal failure after the procedure has yet been found. Conclusions: Our results showed that the laparoscopic RFA on small renal mass was safe, with outcomes of patients comparable with those by partial nephrectomy and percutaneous RFA. Further research and a longer follow-up period are needed to confirm our results. [ABSTRACT FROM AUTHOR]