74 research outputs found
WM-NET: Robust Deep 3D Watermarking with Limited Data
The goal of 3D mesh watermarking is to embed the message in 3D meshes that
can withstand various attacks imperceptibly and reconstruct the message
accurately from watermarked meshes. Traditional methods are less robust against
attacks. Recent DNN-based methods either introduce excessive distortions or
fail to embed the watermark without the help of texture information. However,
embedding the watermark in textures is insecure because replacing the texture
image can completely remove the watermark. In this paper, we propose a robust
deep 3D mesh watermarking WM-NET, which leverages attention-based convolutions
in watermarking tasks to embed binary messages in vertex distributions without
texture assistance. Furthermore, our WM-NET exploits the property that
simplified meshes inherit similar relations from the original ones, where the
relation is the offset vector directed from one vertex to its neighbor. By
doing so, our method can be trained on simplified meshes(limited data) but
remains effective on large-sized meshes (size adaptable) and unseen categories
of meshes (geometry adaptable). Extensive experiments demonstrate our method
brings 50% fewer distortions and 10% higher bit accuracy compared to previous
work. Our watermark WM-NET is robust against various mesh attacks, e.g. Gauss,
rotation, translation, scaling, and cropping
Influence of laser cutting conditions on electrical characteristics of half-size bifacial silicon solar cells
Abstract(#br)The half-size bifacial silicon solar cells have garnered significant research attention in photovoltaic (PV) modules because they render enhanced power output. Herein, the influence of cutting surface and scribing iteration times on electrical characteristics of bifacial silicon solar cells is investigated in detail. The results reveal that the cutting process should be carried out from the rear side and scribing iteration times should be twice. Moreover, we have studied the cutting losses of n-type passivated emitter and rear totally diffused (n-PERT) bifacial solar cells and demonstrated that not mechanical breaking but laser scribing is a major source of losses during the cell separation process. In addition, the damage induced by the cut was systematically investigated and it was observed that the heat-affected zone resulted in negligible damage under optimal cutting conditions. Overall, n-PERT half-cell bifacial modules, sectioned under optimal cutting conditions, can maintain high efficiency and excellent reliability
Preparation and electromechanical properties of PVDF matrix piezo-electric composites containing highly oriented BaTiO3 whiskers
The piezoelectric composites containing highly oriented BaTiO3 whiskers as active phase and PVDF as matrix have been prepared by micro-hole extrusion and orientation in carried fibers. The morphology of oriented BaTiO3 whiskers and microstructure of the composites were observed by SEM. As for its electromechanical properties, it is found that the dielectric constant, piezoelectric constant and remnant of polarization in the BaTiO3 whisker-PVDF composite are considerably higher than that in the BaTiO3 powders-PVDF composite, while the loss factors follow the opposite trend. For the BaTiO3 whisker-PVDF composite, the values of epsilon, d(33) and P-r parallel to the whisker orientation (normal specimen) are much higher than that perpendicular to the whisker orientation (parallel specimen). The significant effects of the connective passages of active phase on electromechanical properties of the piezoelectric composites has also been investigated
Extraction of phosphorus from metallurgical grade silicon using a combined process of Si-Al-Ca solvent refining and CaO-CaF 2 slag treatment
Abstract(#br)A combined purification process of Si-Al-Ca solvent refining and CaO-CaF 2 slag treatment was investigated with a focus on removing phosphorus (P) from metallurgical-grade Si (MG-Si). The primary precipitates in the slag-treated Si-Al-Ca alloy are CaAl 2 Si 2 and CaSi 2 , and these precipitates can be eliminated via leaching with HCl + CH 3 COOH and HCl + HF in sequence. Compared to MG-Si, a higher extraction efficiency of P was achieved with Si-Al-Ca alloy after CaO-CaF 2 slag treatment. Influences of alloy composition, slag components, and operation parameter on the P removal efficiency were studied systematically. The optimal dephosphorization efficiency reached 98.6% when the 70%Si-Al-Ca alloy was treated with 20%CaO–80%CaF 2 slag twice. Furthermore, the mechanism of P removal using the combined process was studied. The results indicate that the Si-Al-Ca solvent refining causes the segregation coefficient of P to be lower, thus facilitating its mass transfer in slag treatment. A large amount of P was reduced and then diffused to the slag phase in the slag experiment. Residual P in the slag-treated alloy was trapped by the CaAl 2 Si 2 phase and was then removed via acid leaching
Analysis of group 12a lymph node metastasis at different sites of gastric adenocarcinoma and its risk factors
Background and purpose: It is not clear that the pattern of lymph node (group 12a) metastasis within the hepatoduodenal ligament (along the hepatic artery) in gastric cancer, its indications for dissection are still controversial, and there is a lack of relevant clinical study data from large samples. This study investigated the risk factors of lymph node group 12a metastasis in gastric cancer at different sites by observing the lymph node metastasis rate. Methods: The medical records of 1 112 gastric cancer patients admitted to the Department of Gastric Surgery in Henan Provincial People’s Hospital from May 2016 to July 2021 were retrospectively analyzed. According to tumor location, they were divided into upper gastric cancer (561 cases), gastric body cancer (224 cases) and gastric antrum cancer (327 cases). The lymph node metastasis rate of group 12a in patients with different parts of gastric cancer was recorded. The c2 test and Fisher’s exact probability test were used to compare the relationship between group 12a lymph node metastasis and clinicopathological features in patients with gastric cancer at different sites. Multivariate logistic regression analysis was used to analyze the risk factors of group 12a lymph node metastasis in patients with gastric cancer at different locations. Results: Group 12a lymph node metastasis occurred in 72 of 1 112 gastric cancer patients, and the overall metastatic rate was 6.5%. Among the 561 cases of upper gastric cancer, 25 cases developed group 12a lymph node metastasis, and the metastatic rate was 4.5%. Of the 224 patients with gastric body cancer, 17 cases were positive in group 12a lymph nodes, and the metastasis rate was 7.6%. Among the 327 cases of gastric antrum cancer, 30 cases were positive in group 12a lymph nodes, and the metastatic rate was 9.2%. Taking the lymph node metastasis in group 12a as the dependent variable, and taking the indicators with statistical significance in univariate analysis as independent variables, they were included in the model for multivariate logistic regression analysis. The results showed that tumor diameter (OR=3.122, 95% CI: 2.896-3.366, P<0.001), T stage (OR=2.406, 95% CI: 1.705-3.396, P<0.001), TNM stage (OR=7.910, 95% CI: 4.755-13.160, P<0.001) were risk factors for lymph node metastasis in group 12a of upper gastric cancer patients. Tumor diameter (OR=2.757, 95% CI: 2.495-3.047, P<0.001), T stage (OR=3.298, 95% CI: 2.346-4.638, P<0.001), vascular nerve invasion (OR=1.839, 95% CI: 1.368-2.473, P<0.001) were risk factors for lymph node metastasis in group 12a of patients with gastric body cancer. Body mass index (BMI) (OR=1.098, 95% CI: 1.023-1.178, P=0.010), tumor diameter (OR=2.865, 95% CI: 1.778-4.616, P<0.001), T stage (OR=13.497, 95% CI: 8.363-21.783, P<0.001), TNM stage (OR=3.806, 95% CI: 3.113-4.653, P<0.001) were risk factors for lymph node metastasis in group 12a of patients with gastric antrum cancer. Conclusion: The total lymph node metastasis rate in group 12a is low. Tumor size, invasion depth, N stage and tumor stage are independent risk factors for group 12a lymph node metastasis in gastric cancer. Besides, vascular nerve invasion is the independent risk factors for gastric body cancer. Gastric body cancer and gastric antrum cancer require routine dissection of group 12a lymph nodes. The metastatic rate of lymph nodes in group 12a of upper gastric cancer is low, and routine dissection is not required. However, when the diameter is ≥6 cm, the depth of tumor invasion is deep (T3-T4), and the tumor stage is late (Ⅲ-Ⅳ), group 12a lymph nodes need to be dissected
Synthesis and biological evaluation of pentacyclic triterpenoid derivatives as potential novel antibacterial agents
A series of ursolic acid (UA), oleanolic acid (OA) and 18β-glycyrrhetinic acid (GA) derivatives were synthesized by introducing a range of substituted aromatic side-chains at the C-2 position after the hydroxyl group at C-3 position was oxidized. Their antibacterial activities were evaluated in vitro against a panel of four Staphylococcus strains. The results revealed that the introduction of aromatic side-chains at the C-2 position of GA led to the discovery of potent triterpenoid derivatives for inhibition of both drug sensitive and resistant S. aureus, while the other two series derivatives of UA and OA showed no significant antibacterial activity even at high concentrations. In particular, GA derivative showed good potency against all four strains of Staphylococcus (MIC = 1.25 - 5 μmol/L) with acceptable pharmacokinetics properties and low cytotoxicity in vitro. Molecular docking was also performed using S. aureus DNA gyrase structure to rationalize the observed antibacterial activity. Therefore, this series of GA derivatives have strong potential for the development of a new type of triterpenoid antibacterial agent
Parathyroid Hormone versus Bisphosphonate Treatment on Bone Mineral Density in Osteoporosis Therapy: A Meta-Analysis of Randomized Controlled Trials
BACKGROUND: Bisphosphonates and parathyroid hormone (PTH) represent the antiresorptive and anabolic classes of drugs for osteoporosis treatment. Bone mineral density (BMD) is an essential parameter for the evaluation of anti-osteoporotic drugs. The aim of this study was to evaluate the effects of PTH versus bisphosphonates on BMD for the treatment of osteoporosis. METHODS/PRINCIPAL FINDINGS: We performed a literature search to identify studies that investigated the effects of PTH versus bisphosphonates treatment on BMD. A total of 7 articles were included in this study, representing data on 944 subjects. The pooled data showed that the percent change of increased BMD in the spine is higher with PTH compared to bisphosphonates (WMD = 5.90, 95% CI: 3.69-8.10, p<0.01,). In the hip, high dose (40 µg) PTH (1-34) showed significantly higher increments of BMD compared to alendronate (femoral neck: WMD = 5.67, 95% CI: 3.47-7.87, p<0.01; total hip: WMD = 2.40, 95%CI: 0.49-4.31, p<0.05). PTH treatment has yielded significantly higher increments than bisphosphonates with a duration of over 12 months (femoral neck: WMD = 5.67, 95% CI: 3.47-7.86, p<0.01; total hip: WMD = 2.40, 95% CI: 0.49-4.31, P<0.05) and significantly lower increments at 12 months (femoral neck: WMD = -1.05, 95% CI: -2.26-0.16, p<0.01; total hip: WMD: -1.69, 95% CI: -3.05-0.34, p<0.05). In the distal radius, a reduction in BMD was significant between PTH and alendronate treatment. (WMD = -3.68, 95% CI: -5.57-1.79, p<0.01). DISCUSSION: Our results demonstrated that PTH significantly increased lumbar spine BMD as compared to treatment with bisphosphonates and PTH treatment induced duration- and dose-dependent increases in hip BMD as compared to bisphosphonates treatment. This study has also disclosed that for the distal radius, BMD was significantly lower from PTH treatment than alendronate treatment
Development of dual-drug-loaded stealth nanocarriers for targeted and synergistic anti-lung cancer efficacy
Combination chemotherapy is widely exploited for suppressing drug resistance and achieving synergistic anticancer efficacy in the clinic. In this paper, the nanostructured targeting methotrexate (MTX) plus pemetrexed (PMX) chitosan nanoparticles (CNPs) were developed by modifying methoxy polye (thylene glycol) (mPEG), in which PEGylation CNPs was used as stealth nanocarriers (PCNPs) and MTX was employed as a targeting ligand and chemotherapeutic agent as well. Studies were undertaken on human lung adenocarcinoma epithelial (A549) and Lewis lung carcinoma (LLC) cell lines, revealing the anti-tumor efficacy of nanoparticle drug delivery system. The co-delivery nanoparticles (MTX-PMX-PCNPs) had well-dispersed with sustained release behavior. Cell counting kit-8 (CCK8) has been used to measure A549 cell viability and the research showed that MTX-PMX-PCNPs were much more effective than free drugs when it came to the inhibition of growth and proliferation. Cell cycle assay by flow cytometry manifested that the MTX-PMX-PCNPs exhibited stronger intracellular taken up ability than free drugs at the same concentration. In vivo anticancer effect results indicated that MTX-PMX-PCNPs exhibited a significantly prolong blood circulation, more tumoral location accumulation, and resulted in a robust synergistic anticancer efficacy in lung cancer in mice. The results clearly demonstrated that such unique synergistic anticancer efficacy of co-delivery of MTX and PMX via stealth nanocarriers, providing a prospective strategy for lung cancer treatment
Study on the preparation and properties of UV curable polyurethane materials modified by organic silicon
In this paper, polyester polyol, toluene diisocyanate (TDI) and hydroxyethyl acrylate (HEA) were taken as the raw materials to synthesize polyurethane acrylate. UV curable organic silicon nano sol was synthesized by γ-methacryloxypropyltrime-thoxysilane. The UV curable polyurethane materials modified by organic silicon were prepared based on the UV curable organic silicon nano sol and synthesized polyurethane acrylate. This paper studies on the mechanical properties of organic silicon modified UV curable polyurethane materials and puts forward the micro model that inorganic phase is bonded to the resin in the form of chemical bonds. The results show that the heat resistance and mechanical properties of hybrid materials are improved with the increase of the nano silica sol’s contents , the abrasion resistance of hybrid coatings is also improved and the silica nano particles are well dispersed in the organic phase
The effects of role stressors and smartphone interactions on delivery riders’ unsafe behaviors during the delivery process in China
Objectives. Although some studies have shown role stressors can lead to unsafe behaviors, it is unclear how role stressors induce delivery riders’ unsafe behaviors. We found that delivery riders suffered from tremendous role stressors during the delivery process and had to conduct frequent smartphone interactions. This study aimed to explore the effects of role stressors and smartphone interactions on delivery riders’ unsafe behaviors. Methods. First, a questionnaire survey (N = 326) was used to collect data, and correlation and regression analyses were conducted to explore the relationship between role stressors, smartphone interaction frequency and delivery riders’ unsafe behaviors. Second, a scenario survey (N = 35) was conducted, and comparative analysis was used to further explore how smartphone interactions affect delivery riders’ unsafe behaviors. Results. The questionnaire survey revealed that role stressors, smartphone interaction frequency and delivery riders’ unsafe behaviors were positively correlated. In addition, the role stressors forced delivery riders to conduct necessary and unnecessary smartphone interactions. The scenario survey found that smartphone interactions reduced delivery riders’ motion speed and motion ability, and increased their psychology, so they had a risk-taking mentality, which led to an increase in unsafe behaviors.</p
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