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Bypass coupling triple-wire gas indirect arc welding (TW-GIA) has been proposed to control the heat input of base metal and consequently improve the weld forming as per the requirement. The influence of the bypass current on arc behavior, welding stability, and weld forming have been investigated. Results showed that the wetting angle and reinforcement reduced gradually, and the weld bead penetration increased with the bypass current increase. The reason was that the workpiece heating mode was changed due to the bypass circuit coupling. It was observed that the heat source was composed of two indirect arcs and two direct arcs, and they were in a coupling state. When the bypass current was 280 A, the electrical parameters of arc fluctuations were at a maximum, and the coupled arc state was not conducive to obtain a stable welding process. Compared to the lack of sidewall fusion and incomplete joint penetration defects of the weld with TW-GIA, the good butt joint of 12 mm thickness steel plates was successfully obtained with bypass coupling TW-GIA under the same energy consumption. [ABSTRACT FROM AUTHOR]

Background: Perioperative chemotherapy is the standard of care for patients with locally advanced gastric and gastroesophageal junction cancer. Recent evidence demonstrated the addition of programmed cell death protein 1 (PD-1) inhibitors enhanced therapeutic efficacy. However, the mechanisms of response and resistance remain largely undefined. A detailed multiomic investigation is essential to elucidate these mechanisms., Methods: We performed whole-exome sequencing, whole-transcriptome sequencing, multiplex immunofluorescence and single-cell RNA sequencing on matched pretreatment and post-treatment samples from 30 patients enrolled in an investigator-initiated Phase 2 clinical trial (NCT04908566). All patients received neoadjuvant PD-1 inhibitors in combination with chemotherapy. A major pathologic response (MPR) was defined as the presence of no more than 10% residual viable tumor cells following treatment., Results: Before treatment, the positive ratio of CD3+T cells in both the tumor parenchyma and stroma was significantly higher in the non-MPR group compared with the MPR group (p=0.042 and p=0.013, respectively). Least absolute shrinkage and selection operator regression was employed for feature gene selection and 13 genes were ultimately used to construct a predictive model for identifying MPR after surgery. The model exhibited a perfect area under curve (AUC) of 1.000 (95% CI: 1.000 to 1.000, p<0.001). Post-treatment analysis revealed a significant increase in CD3+T cells, CD8+T cells and NK cells in the tumor stroma of MPR patients. In the tumor parenchyma, aside from a marked increase in CD8+T cells and NK cells, a notable reduction in macrophage was also observed (all p<0.05). Importantly, forkheadbox protein 3 (FOXP3), the principal marker for regulatory T cells (Treg) cells, showed a significant decrease during treatment in MPR patients. FOXP3 expression in the non-MPR group was significantly higher than in the MPR group (p=0.0056) after treatment. Furthermore, single-cell RNA sequencing analysis confirmed that nearly all Treg cells were derived from the non-MPR group., Conclusions: Our study highlights the critical role of dynamic changes within the tumor immune microenvironment in predicting the efficacy of neoadjuvant combined immunochemotherapy. We examined the disparities between MPR/non-MPR groups, shedding light on potential mechanisms of immune response and suppression. In addition to bolstering cytotoxic immune responses, specifically targeting Treg cells may be crucial for enhancing treatment outcomes., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

MYC-rearranged high-grade B-cell lymphoma (HGBCL) patients with concurrent BCL2 rearrangements (HGBCL-MYC/BCL2) often have a poor prognosis with standard chemoimmunotherapy and may benefit from more intensified regimens. Conventional fluorescence in situ hybridization (FISH) is the gold standard for detecting rearrangements, but it has several limitations. This study compared DNA- and RNA-sequencing with FISH to detect clinically relevant rearrangements in HGBCL. Archived formalin-fixed, paraffin-embedded samples from 34 patients who underwent FISH testing were analyzed using targeted DNA- and RNA-sequencing. DNA- and RNA-sequencing identified six and five out of the 12 MYC rearrangements detected by FISH, 10 and 6 out of 10 FISH-detectable BCL2 rearrangements, and 13 and 10 out of the 18 FISH-detectable BCL6 rearrangements. When combining DNA- and RNA-sequencing (integrated NGS), the sensitivity for detecting MYC, BCL2, and BCL6 rearrangements was 58.3%, 100%, and 73.7%, respectively. Both DNA- and RNA-sequencing detected the EIF4A2::BCL6 fusion missed by FISH. FISH identified 12 HGBCL-MYC/BCL2 out of 34 cases, while the integrated NGS strategy identified 7 cases, with 5 cases showing discordant results (41.7%). Additionally, patients with DLBCL/HGBCL-MYC/BCL2 had significantly shorter overall survival than other patients. Our results suggest that an integrated NGS strategy should not replace FISH or be routinely used in the workup to detect the clinically relevant rearrangements in HGBCL. It may serve as a complement to FISH testing when FISH shows negative results.