Search

Threaded fasteners are one of the most commonly used connection methods for mechanical structures. Its primary function is to generate appropriate clamping forces and fasten the connected parts. An inappropriate preload can cause loosening, fatigue fracture, and other problems. This will affect the safety and reliability of mechanical equipment. The precise control of the preload has become a critical issue in mechanical assembly processes. Over the past few decades, various tightening measures and methods have been proposed to address this issue. However, many problems continue to exist with practical applications that have not been reviewed comprehensively and systematically. First, various control methods were summarized systematically, and their advantages and disadvantages in engineering applications were analyzed. Torque control is the most widely used tightening method owing to its simple operation and low cost. Therefore, the research on the torque control method was summarized systematically from three aspects: the torque–preload correlation formula, effective friction radius, and friction characteristics during tightening. In addition, the special circumstances that may increase preload uncertainty were discussed. Finally, based on a summary of the current research status, the prospects for future research were discussed. This study would aid researchers in extensively understanding the problems in preload control. [ABSTRACT FROM AUTHOR]

With the success of immunotherapy in advanced esophageal cancer, neoadjuvant chemo-immunotherapy (CIT) is being increasingly used for local staged esophageal cancer, especially in the context of clinical trials, which brings similar pCR with neoadjuvant chemoradiotherapy and shows promising results. However, there is still a part of potentially operable patients can't undergo surgery after neoadjuvant chemo-immunotherapy. The follow-up treatment and prognosis of this population remain unclear. Patients pathologically diagnosed with ESCC, clinical stage T1-3N+M0 or T3-4aNanyM0 (AJCC 8th), PS 0–1 were retrospectively enrolled from 1/2020 to 6/2021 in Zhejiang Cancer Hospital. All patients firstly received PD-1 inhibitors plus chemotherapy (albumin paclitaxel, 260 mg/m2 on day 1 plus carboplatin AUC = 5 on day 1) every 3 weeks for 2–4 cycles. For those patients who did not receive surgery, definitive radiotherapy with 50.4 Gy/28F or 50 Gy/25F was adopted using VMAT, concurrent with chemotherapy or alone. The concurrent chemotherapy regimens included weekly TC (paclitaxel 50 mg/m2, d1, carboplatin AUC = 2, d1) or S1 (60 mg bid d1–14, 29–42). The survival outcomes and treatment toxicity were recorded and analyzed. A total of 56 eligible patients were finally identified from 558 patients who were treated in department of thoracic surgery, among all the patients, 25 (44.6%) received radiotherapy alone, and 31 (55.4%) received chemoradiotherapy after neoadjuvant CIT. The median follow-up was 20.4 months (interquartile range [IQR] 8.7–27 months). The median PFS and OS were 17.9 months (95% confidence interval [CI] 11.0–21.9 months) and 20.5 months (95% CI 11.8–27.9 months), respectively. In the subgroup analysis, the median OS was 26.3 months (95% CI 15.33–NA) for patients exhibiting partial response (PR) to CIT, compared to 17 months (95% CI 8.77–26.4) for those with stable disease (SD) or progressive disease (PD), yielding a hazard ratio (HR) of 0.54 (95% CI 0.27–1.06, P = 0.07). No significant difference was observed for patients received radiotherapy alone or chemoradiotherapy with HR = 0.73 (95% CI 0.72–2.6, P = 0.33). The most common Adverse events (AEs) observed during this study were anemia (98.2%), leukopenia (83.9%), thrombocytopenia (53.6%). AEs of grade ≥ 3 radiation-induced pneumonitis and esophagitis were 12.5% and 32.1%, especially, 6 patients (10.7%) died from esophageal fistula and 2 patients (3.6%) died from grade 5 pneumonitis. For local advanced ESCC patients after neoadjuvant CIT who did not receive surgery, definitive radiotherapy was an optional treatment strategy. However, those patients with no response to CIT also showed poor response to radiotherapy, and particular attention should be paid to treatment related toxicity, especially esophageal fistula. [ABSTRACT FROM AUTHOR]

Background: Prophylactic cranial irradiation (PCI) is part of standard care in limited-stage small cell lung cancer (SCLC) at present. As evidence from retrospective studies increases, the benefits of PCI for limited-stage SCLC are being challenged. Methods: A multicenter, prospective, randomized controlled study was designed. The key inclusion criteria were: histologically or cytologically confirmed small cell carcinoma, age ≥ 18 years, KPS ≥ 80, limited-stage is defined as tumor confined to one side of the chest including ipsilateral hilar, bilateral mediastinum and supraclavicular lymph nodes, patients have received definitive thoracic radiotherapy (regardless of the dose-fractionation of radiotherapy used) and chemotherapy, evaluated as complete remission (CR) of tumor 4–6 weeks after the completion of chemo-radiotherapy. Eligible patients will be randomly assigned to two arms: (1) PCI and brain MRI surveillance arm, receiving PCI (2.5 Gy qd to a total dose of 25 Gy in two weeks) followed by brain MRI surveillance once every three months for two years; (2) brain MRI surveillance alone arm, undergoing brain MRI surveillance once every three months for two years. The primary objective is to compare the 2-year brain metastasis-free survival (BMFS) rates between the two arms. Secondary objectives include 2-year overall survival (OS) rates, intra-cranial failure patterns, 2-year progression-free survival rates and neurotoxicity. In case of brain metastasis (BM) detect during follow-up, stereotactic radiosurgery (SRS) will be recommended if patients meet the eligibility criteria. Discussion: Based on our post-hoc analysis of a prospective study, we hypothesize that in limited-stage SCLC patients with CR after definitive chemoradiotherapy, and ruling out of BM by MRI, it would be feasible to use brain MRI surveillance and omit PCI in these patients. If BM is detected during follow-up, treatment with SRS or whole brain radiotherapy does not appear to have a detrimental effect on OS. Additionally, this approach may reduce potential neurotoxicity associated with PCI. [ABSTRACT FROM AUTHOR]

The benefit of local ablative therapy (LAT) for oligo-recurrence has been investigated and integrated into the treatment framework. In recent decades, stereotactic body radiation therapy (SBRT) has been increasingly used to eliminate metastasis owing to its high rate of local control and low toxicity. This study aimed to investigate the outcomes of SBRT for patients with lung oligo-recurrence of non-small cell lung cancer (NSCLC) from our therapeutic center. Patients with lung oligo-recurrence of NSCLC treated with SBRT between December 2011 and October 2018 at Cancer Hospital of the University of Chinese Academy of Sciences (Zhejiang Cancer Hospital) were reviewed. The characteristics, treatment-related outcomes, and toxicities of the patients were analyzed. Univariable and multivariable Cox regression were performed to identify the factors associated with survival. A total of 50 patients with lung oligo-recurrence of NSCLC were enrolled. The median follow-up period was 23.6 months. The 3-year local progression-free survival (LPFS), progression-free survival (PFS) and overall survival (OS) after SBRT were 80.2%, 21.9% and 45.3%, respectively. Patients in the subgroup with LAT to all residual diseases showed significantly improved OS and PFS. No treatment-related death occurred after SBRT. SBRT is a feasible option to treat patients with lung oligo-recurrence of NSCLC, with high rates of local control and low toxicity. LAT to all residual diseases was associated with better survival outcomes. Future prospective randomized clinical trials should evaluate SBRT strategies for such patients. [ABSTRACT FROM AUTHOR]