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Zhangdi Xu,1– 3,* Bihui Pan,1– 3,* Yue Li,1– 3 Yi Xia,1– 3 Jinhua Liang,1– 3 Yilin Kong,1– 3 Xinyu Zhang,1– 3 Jing Tang,1– 3 Li Wang,1– 3 Jianyong Li,1– 3 Wei Xu,1– 3,* Jiazhu Wu1– 3,* 1Department of Hematology, the First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, Nanjing, People’s Republic of China; 2Key Laboratory of Hematology of Nanjing Medical University, Nanjing, People’s Republic of China; 3Collaborative Innovation Center for Cancer Personalized Medicine, Nanjing, People’s Republic of China*These authors contributed equally to this workCorrespondence: Jiazhu Wu; Wei Xu, Department of Hematology, the First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, Nanjing, 210029, People’s Republic of China, Tel +86-25-83781120, Fax +86-25-83781120, Email wujiazhu09@sina.com; xuwei10000@hotmail.comBackground: Chronic lymphocytic leukemia (CLL) is a subtype of B-cell malignancy with high heterogeneity. Ferroptosis is a novel cell death induced by iron and lipid peroxidation and exhibits prognostic value in many cancers. Emerging studies on long non-coding RNAs (lncRNAs) and ferroptosis reveal the unique value in tumorigenesis. However, the prognostic value of ferroptosis-related lncRNAs (FRLs) remains unclear in CLL.Aim: We aimed to construct a FRLs risk model to predict prognosis and improve prognostic stratification for clinical practice.Methods: RNA-sequencing data and clinical characteristics of CLL patients were downloaded from the GEO database. Based on ferroptosis-related genes from FerrDb database, differentially expressed FRLs with prognostic significance were identified and used to generate the risk model. The capability of the risk model was assessed and evaluated. GO and KEGG analyses were performed to confirm biological roles and potential pathways.Results: A novel ferroptosis-related lncRNAs prognostic score (FPS) model containing six FRLs (PRKCQ, TRG.AS1, LNC00467, LNC01096, PCAT6 and SBF2.AS1) was identified. Patients in the training and validation cohort were evenly divided into high- and low-risk groups. Our results indicated that patients in the high-risk group had worse survival than those in the low-risk group. Functional enrichment analyses showed that the differently expressed genes (DEGs) between the two groups were enriched in the chemokine signaling pathway, hematopoietic cell lineage, T cell differentiation, TCR pathway and NF-κB pathway. Moreover, significant differences in immune cell infiltration were also observed. Surprisingly, FPS was proved to be an independent prognostic indicator for OS.Conclusion: We established and evaluated a novel prognostic risk model with 6 FRLs that could predict prognosis accurately and describe the distinct immune infiltration in CLL.Keywords: chronic lymphocytic leukemia, ferroptosis, long non-coding RNAs, prognosis, immune infiltration

The effects of the two types of typical spatial laser beam profiles (SLBP), including the super-Gaussian profile (SGP) and Gaussian profile (GP), on the thermal-fluid transport during laser-based d...

For laser direct metal deposition (LDMD) process, a general powder distribution model of discontinuous coaxial powder stream (DCPS) was developed based on homogeneous transformation. An image-based powder measurement (IBPM) technique, whose illumination light is a cylindrical light, was used to acquire powder distribution characteristics. A set of data preprocessing methods were proposed to validate the developed model. Correlation analysis indicated that the matching coefficients between the measured and simulated data are above 0.99 on the axial plane of the coaxial powder stream, whereas above 0.95 on the cross-sections near the focal spot. The error of the predicted focal spot position was less than 1%. Mean sensitivity indexes inferred that both the injection radius and the injection angle of the powder-fed head have significant influence on the focal spot characteristics of the DCPS compared to the nozzle exit diameter. Reducing the focal spot diameter can improve the powder utilization efficiency. For achieving safe deposition process and stable powder delivery, the standoff distance at the focal spot should be greater than 6 mm.

The thin-walled structures of Al2O3-ZrO2 ceramic were deposited using laser direct material deposition (LDMD). The effect of heat input on Al2O3-ZrO2 ceramics with different Al2O3/ZrO2 powder weight ratios were studied and the microstructures in different regions of the deposit were analyzed. For the thin-walled structure with 85 wt% Al2O3 and 15 wt% ZrO2 (H1) hypoeutectic deposition, the grain growth angle increases with increasing heat input. From the frontier region to the central region, the microstructure was transformed from a columnar dendritic structure to a cellular structure. For thin-walled structure with 65 wt% Al2O3 and 35 wt% ZrO2 (H2) hypoeutectic deposition, the mean thickness of the banded structure increases with increasing heat input but decreased when the heat input was 124.3 J/mm. The minimum thickness of the banded structure was 0.16 mm. The microstructure of the frontier region exhibited cellular dendritic, while the amorphous structures appeared in the central region. The maximum hardness of the thin-walled structure with H1 hypoeutectic deposit was 21.4 GPa while the maximum fracture toughness of the H2 hypoeutectic deposit was 4.61 MPa m1/2. The fracture toughness was found to increases as the thickness of the banded structure decreases under high heat input. The results of this research provide some basis for attaining high quality Al2O3-ZrO2 ceramics by laser direct material deposition.

A three-dimensional transient heat and mass transfer model for laser-powder coupling is created based on the lumped parameter method. A super-Gaussian beam model that is closer to the fiber laser beam profile for welding is employed instead of a frequently-used Gaussian beam. A beam characteristic parameter identification method is proposed to identify the beam characteristic parameters such as the focal spot radius and Rayleigh length. The spatial distribution of the beam power density is reconstructed. The super-Gaussian beam model has a better goodness-of-fit index than the Gaussian beam model. Finite difference method is used to solve the heat and mass transfer model developed. Some powder particles, under the action of three types of laser beams, have evaporated before falling into the laser-induced pool. The average heating rate for the super-Gaussian beam and non-ideal Gaussian beam is lower than that of the ideal Gaussian beam. Although the heated powder distribution zone and the melted powder distribution zone on the workpiece surface for the super-Gaussian beam are larger, the maximum powder mass loss by evaporation is the smallest. The effect of the identified super-Gaussian beam and non-ideal Gaussian beam on the heat and mass transfer zone and evaporation-induced mass loss is not significantly different, except for the ideal GB.

Laser additive manufacturing facilitates the manufacture of functional structures, gradient materials, and complex inner structure parts. This process, which is known for its rapid and green manufacturing capabilities, presents an important direction for the development of advanced manufacturing technologies. However, contour accuracy introduces a technical bottleneck that remains unsolved. In five-axis laser additive manufacturing, tool vector control plays a pivotal role in determining contour accuracy. Accordingly, this article proposes a method for tool vector control in five-axis laser additive manufacturing. This method utilizes a five-axis spiral milling tool path to change the vector direction for five-axis laser additive manufacturing and to improve the contour precision of complex surface parts. First, the continuous spiral tool path is obtained by using commercial CAM software. Second, based on the relationship between the additive and subtractive control vectors, the control vector of the obtained spiral tool path is converted into the tool vector control of the laser cladding. Third, the tool position point and tool vector are converted into a G code program via post processing. Fourth, the performance of the proposed method is verified by conducting a virtual simulation and a five-axis laser cladding experiment with a blade specimen.

T cell exhaustion is one of the hallmarks of cancer and chronic viral infections. Revitalization of exhausted T cells is critical for restoring immune function and curing diseases. Recent studies suggest that epigenetic mechanisms are directly involved in the transcriptional control of T cell exhaustion. Decoding the epigenome specific to exhausted T cells is a pivotal step toward development of therapeutic approaches for overcoming T cell exhaustion in infections and cancer.

Ultrafast lasers have brought revolutionary changes to crystalline materials processing, leading to a wealth of new applications in many areas. In this paper, the authors report a method to modulate crack formation inside a single-crystal sapphire using ultrafast laser zero-order Bessel beams. The number of cracks, transverse crack length, and direction of crack propagation can be modulated by adjusting the pulse duration, single pulse energy, and scanning path, independently. Through the crack control method proposed herein, linear and curvilinear cleaving without debris or taper are demonstrated. The experimental results prove that this method of control is feasible and it is easy to achieve curvilinear cleaving of sapphire.

In the field of automotive manufacturing, it is pivotal to obtain a moderate penetration status when joining automotive parts by laser keyhole welding. As a typical characteristic of laser keyhole welding, keyhole behavior can directly reflect the penetration status of the weld bead. In this paper, a coaxial vision monitoring system with a laser auxiliary illuminant is established to collect the keyhole images from the top-face of the weldment during laser welding. The interferences of the bright spot caused by mirror reflection and metal vapors in the collected images are fully considered. Then, a hybrid adaptive keyhole detection algorithm is proposed to accurately segment the keyhole region. Five static image features are extracted from the perspective of the average gray value, area, and perimeter in the keyhole region. The feature selection method of Wrapper, which combines a sequential forward searching algorithm with a random forest classifier, is used to select ten penetration status features (PSFs). The constructed prediction model of weld penetration based on the selected PSFs has excellent performance. The proposed monitoring method in laser keyhole welding irradiated by a laser auxiliary illuminant is contributed to the closed-loop control of weld penetration to obtain a moderate penetration status.

The heat and mass transfer behavior is the influencing factor of welding quality, during filler powder laser welding. The characteristics of plasma and keyhole can characterize the heat and mass transfer behavior. Experimental platforms were built to observe the effect of powder feeding rate on the heat and mass transfer behavior. The main results of the experiment are as follows. In the process of filler powder laser welding, the keyhole depth and fusion depth were improved by selecting the critical value of powder feeding rate 5 g/min as the welding process parameter. When the powder feeding rate exceeded the critical value, the electron temperature and electron density decreased and increased respectively. The keyhole depth decreased with the increase of the inverse bremsstrahlung absorption coefficient of the keyhole plasma at the top of the keyhole. The keyhole area increased with the increase of plasma pressure at the keyhole opening. The inverse bremsstrahlung absorption of plasma plume and the number of powder particles sprayed into the molten pool were the factors that caused the decrease of the surface temperature and the length of the molten pool.