210 research outputs found
Design, Analysis and Testing of Piezoelectric Tool Actuator for Elliptical Vibration Cutting
In the field of ultraprecision machining, the structured surfaces with various micro/nano characteristics may have different advanced functions, such as wettability modifications, tribological control and hybrid micro-optics. However, the machining of micro/nano structured surfaces is becoming a challenge for present cutting method. Especially for the difficult-to-cut materials, it is impossible to manufacture complex micro/nano features by using traditional cutting methods. The complex features require a cutting tool no longer confined to the traditional motion guide. The cutting tool should have more quick response velocity and flexible modulated ability. This chapter aims to make an introduction for piezoelectric tool actuator used in elliptical vibration cutting, which can be offering tertiary cutting operations with quick response and flexible modulated ability. The content covers the working principle of piezoelectric tool actuator, compliant mechanism design, static modeling, kinematic and dynamic modeling, structure optimization and offline testing
SEED-X: Multimodal Models with Unified Multi-granularity Comprehension and Generation
The rapid evolution of multimodal foundation model has demonstrated
significant progresses in vision-language understanding and generation, e.g.,
our previous work SEED-LLaMA. However, there remains a gap between its
capability and the real-world applicability, primarily due to the model's
limited capacity to effectively respond to various user instructions and
interact with diverse visual data. In this work, we focus on bridging this gap
through integrating two enhanced features: (1) comprehending images of
arbitrary sizes and ratios, and (2) enabling multi-granularity image
generation. We present a unified and versatile foundation model, namely,
SEED-X, which is able to model multi-granularity visual semantics for
comprehension and generation tasks. Besides the competitive results on public
benchmarks, SEED-X demonstrates its effectiveness in handling real-world
applications across various domains after instruction tuning. We hope that our
work will inspire future research into what can be achieved by versatile
multimodal foundation models in real-world applications. The models, codes, and
datasets will be released in https://github.com/AILab-CVC/SEED-X.Comment: Project released at: https://github.com/AILab-CVC/SEED-
Study on the tool wear of 3-D elliptical vibration cutting
Abstract. As always, the rapid wear of tools was one of the key factors limiting the precise turning of difficult-to-machine materials with diamond tool. 3-D elliptical vibration cutting has inherited many advantages of elliptical vibration cutting, such as the intermittent cutting property and friction reverse property. However, studies on the tool wear of three-dimensional elliptical vibration cutting has not been reported yet. The formation principle of 3-D cutting elliptical trajectory was analysed and a prediction model of tool wear was established in the present work. Besides, a self-developed three-dimensional elliptical vibration device was employed to conduct turning experiment. Compared with the proposed model, the experimental results showed a great agreement with the proposed prediction model. This work may provide a reference for the further optimization of the 3-D elliptical vibration cutting parameters.
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Engineering Co Single Atoms in Ultrathin BiOCl Nanosheets for Boosted CO<sub>2</sub> Photoreduction
Despite the development of a range of photocatalysts for CO2 reduction, the practical applications are significantly limited by low conversion efficiencies and their reliance on sacrificial agents, which are rooted in thermodynamic and kinetic challenges related to CO2 conversion. Here, the engineering of Co single atoms in ultrathin single-crystal BiOCl nanosheets for boosted photocatalytic CO2 reduction is reported. The engineering of Co atoms modulates the distribution of photogenerated charges at the catalyst surface, controlling key surface reaction dynamics and suppressing surface electron-hole recombination. This modulation also improves light absorption and enhances CO2 adsorption and activation, leading to more efficient surface reactions. Notably, CO2 is stably adsorbed onto the (001) face of BiOCl through a Bi-O-C(= O)-Co-O coordination unit, which lowers the activation energy for CO2 reduction and reduces the formation energy of COOH− intermediates. As a result, the BiOCl photocatalysts achieve a CO formation rate of 183.9 µmol g−1 h−1, when irradiated with a 300 W Xe lamp without cocatalysts or sacrificial agents. It represents an ≈13-fold increase compared to that of pristine BiOCl, and surpasses most reported Bi-based photocatalysts to date. Current work provides valuable insights into engineering of single atoms for developing advanced CO2-reduction photocatalysts.</p
miR-627-5p inhibits malignant progression of cervical cancer by targeting ANGPTL4
In recent years, accumulating evidence has highlighted the critical role of miR-627-5p in the occurrence and progression of various cancers. However, its specific role and mechanism in cervical cancer (CC) remain unclear. This study aimed to elucidate the mechanism by which miR-627-5p inhibits the malignant progression of CC and assess its potential clinical implications. In C33A cells, the mRNA expression levels of ANGPTL4 and miR-627-5p were analyzed using qRT-PCR. The miR-627-5p mimics and their control (miR-NC) were transfected into C33A cells to determine whether miR-627-5p directly regulates ANGPTL4 expression. A comprehensive suite of assays, including CCK-8, migration, transwell, flow cytometry, and Western blotting, was conducted to evaluate how miR-627-5p modulates the malignant biological behavior of CC cells. Rescue experiments were performed by overexpressing ANGPTL4. In C33A cells, miR-627-5p expression was reduced, whereas ANGPTL4 expression was elevated. Further analysis confirmed that miR-627-5p negatively regulates ANGPTL4 by directly targeting its 3'-UTR. Functional assays demonstrated that miR-627-5p inhibits proliferation, invasion, migration, and epithelial-mesenchymal transition (EMT) while promoting apoptosis and S-phase arrest in C33A cells, effects that were reversed by ANGPTL4 overexpression. These findings highlight the potential of miR-627-5p as both a biomarker and a therapeutic target for CC. By inhibiting EMT and regulating ANGPTL4 expression, miR-627-5p may provide a novel avenue for improving therapeutic strategies, particularly in advanced or metastatic CC. Moreover, miRNA-based therapies, supported by advanced delivery systems such as nanoparticle carriers, could enhance the stability and precision of miR-627-5p applications. This study lays the groundwork for future research integrating miR-627-5p into precision medicine approaches for CC treatment
Clinical Study Efficacy of Combined Laparoscopic and Hysteroscopic Repair of Post-Cesarean Section Uterine Diverticulum: A Retrospective Analysis
Background. Diverticulum, one of the long-term sequelae of cesarean section, can cause abnormal uterine bleeding and increase the risk of uterine scar rupture. In this study, we aimed to evaluate the efficacy of combined laparoscopic and hysteroscopic repair, a newly occurring method, treating post-cesarean section uterine scar diverticulum. Methods. Data relating to 40 patients with post-cesarean section uterine diverticulum who underwent combined laparoscopic and hysteroscopic repair were retrospectively analyzed. Preoperative clinical manifestations, size of uterine defects, thickness of the lower uterine segment (LUS), and duration of menstruation were compared with follow-up findings at 1, 3, and 6 months after surgery. Results. The average preoperative length and width of uterine diverticula and thickness of the lower uterine segment were recorded and analyzed. The average durations of menstruations at 1, 3, and 6 months after surgery were significantly shorter than the preoperative one ( < 0.05), respectively. At 6 months after surgery, the overall success improvement rate of surgery was 90% (36/40). Three patients (3/40 = 7.5%) developed partial improvement, and 1/40 (2.5%) was lost to follow-up. Conclusions. Our findings showed that combined treatment with laparoscopy and hysteroscopy was an effective method for the repair of post-cesarean section uterine diverticulum
Ticagrelor vs Clopidogrel in CYP2C19 loss-of-function carriers with Stroke or TIA
BACKGROUNDComparisons between ticagrelor- aspirin and clopidogrel-aspirin in CYP2C19 loss-of-function carriers have not been well studied for secondary stroke prevention.METHODSWe conducted a randomized, double-blind, placebo-controlled trial of 6,412 patients with a minor ischemic stroke or TIA who carried CYP2C19 LOF alleles determined by point-of-care testing. Patients were randomly assigned within 24 hours after symptom onset, in a 1:1 ratio to receive ticagrelor (180 mg loading dose on day 1 followed by 90 mg twice daily for days 2 through 90) or clopidogrel (300 mg loading dose on day 1 followed by 75 mg per day for days 2 through 90), plus aspirin (75-300 mg loading dose followed by 75 mg daily for 21 days). The primary efficacy outcome was stroke and the primary safety outcome was severe or moderate bleeding, both within 90 days. RESULTSStroke occurred within 90 days in 191 (6.0%) versus 243 (7.6%), respectively (hazard ratio, 0.77; 95% confidence interval, 0.64 to 0.94; P=0.008). Moderate or severe bleeding occurred in 9 patients (0.3%) in the ticagrelor-aspirin group and in 11 patients (0.3%) in the clopidogrel-aspirin group; any bleeding event occurred in 170 patients (5.3%) vs 80 (2.5%), respectively. CONCLUSIONSAmong Chinese patients with minor ischemic stroke or TIA within 24 hours after symptoms onset who were carriers of CYP2C19 loss-of-function alleles, ticagrelor- aspirin was modestly better than clopidogrel-aspirin for reducing the risk of stroke but was associated with more total bleeding events at 90 days. (CHANCE-2 ClinicalTrials.gov number, NCT04078737.
Dual Antiplatelet Treatment up to 72 Hours after Ischemic Stroke
BackgroundDual antiplatelet treatment has been shown to reduce recurrence of stroke compared to aspirin alone when initiated early after an acute stroke. The effect of clopidogrel and aspirin versus aspirin alone within 72 hours of acute cerebral ischemia from atherosclerosis has not been well studied.MethodsWe conducted a randomized, double-blind, placebo-controlled, 2-by-2 factorial trial in patients with mild ischemic stroke or high-risk transient ischemic attack (TIA) of presumed atherosclerotic cause, not receiving thrombolysis or thrombectomy in 222 hospitals in China. Patients were randomly assigned within 72 hours after symptom onset in a 1:1 ratio, to receive clopidogrel (300mg on day 1, 75mg daily on days 2-90) and aspirin (100-300mg on day1, 100mg daily on days 2-21), or clopidogrel placebo and aspirin (100-300mg on day1, 100mg daily on days 2-90). There was no interaction between this component of the factorial trial design trial and a second part that tested immediate vs delayed stain treatment and is reported separately. The primary efficacy outcome was a new stroke, and the primary safety outcome was moderate-to-severe bleeding, both within 90 days.ResultsA total of 6100 patients were enrolled, 3050 assigned to each trial group. The qualifying event for enrollment was TIA in 13%. Approximately 13% of patients were assigned to a treatment group within 24 hours and 87% were assigned between 24 and 72 hours of onset of stroke. A new stroke occurred in 222 (7.3%) in the clopidogrel-aspirin group, and 279 (9.2%) in the aspirin group (hazard ratio, 0.79; 95% confidence interval [CI], 0.66-0.94; P=0.008). Moderate-to-severe bleeding occurred in 27 (0.9%) and 13 patients (0.4%), respectively (hazard ratio, 2.08; 95% CI, 1.07-4.04, P=0.03).ConclusionsAmong patients with mild ischemic stroke or high-risk TIA of presumed atherosclerotic cause, combined clopidogrel-aspirin initiated within 72 hours of onset was superior to aspirin alone in reducing the risk of new stroke at 90 days but was associated with a low but increased risk of moderate-to-severe bleeding
Epithelioid inflammatory myofibroblastic sarcoma: a clinicopathological, immunohistochemical and molecular cytogenetic analysis of five additional cases and review of the literature
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