Search

Bistable composite structures have a wide application prospect in the design of deformable structures. In this study, the snap behaviors of unsymmetric cross-ply bistable composites with different thicknesses are investigated. Besides the experiments, the relationships between load and displacement during the snap process are also analyzed by finite element (FE) methods. The load-displacement curves of composite shell with four layers and two layers are completely different. The results of the two-layer cylindrical shell with resin layer are in good agreement with the experimental results. The resin layer has great influence on the snap behaviors of the two-layer bistable cylindrical shell, although it has little effect on the four-layer cylindrical shell. So it cannot be ignored in the analyzing of two-layer bistable shell. The cause of experimental errors is also analyzed. The research results of this paper have reference value for the engineering design of bistable composite structures. [ABSTRACT FROM AUTHOR]

Baicalin, a major flavonoid extracted from Scutellaria baicalensis Georgi (Lamiaceae), has been shown to exert therapeutic effects on pulmonary fibrosis (PF). To use serum metabolomics combined with biochemical and histopathological analyses to clarify anti-PF mechanisms of baicalin on metabolic pathways and the levels of potential biomarkers. Forty male Sprague–Dawley rats were randomly divided into the control, PF model, prednisolone acetate-treated (4.2 mg/kg/day) and baicalin-treated (25 and 100 mg/kg/day) groups. A rat model of PF was established using a tracheal injection of bleomycin, and the respective drugs were administered intragastrically for 4 weeks. Histomorphology of lung tissue was examined after H&E and Masson's trichrome staining. Biochemical indicators including SOD, MDA and HYP were measured. Serum-metabonomic analysis based on UPLC-Q-TOF/MS was used to clarify the changes in potential biomarkers among different groups of PF rats. Both doses of baicalin effectively alleviated bleomycin-induced pathological changes, and increased the levels of SOD (from 69.48 to 99.50 and 112.30, respectively), reduced the levels of MDA (from 10.91 to 5.0 and 7.53, respectively) and HYP (from 0.63 to 0.41 and 0.49, respectively). Forty-eight potential biomarkers associated with PF were identified. Meanwhile, the metabolic profiles and fluctuating metabolite levels were normalized or partially reversed after baicalin treatment. Furthermore, baicalin was found to improve PF potentially by the regulation of four key biomarkers involving taurine and hypotaurine metabolism, glutathione metabolism, and glycerophospholipid metabolism. These findings revealed the anti-fibrotic mechanisms of baicalin and it may be considered as an effective therapy for PF. [ABSTRACT FROM AUTHOR]

Objective: To investigate whether closed suction drainage (CSD) is related to accelerated rehabilitation of patients after open reduction and internal fixation (ORIF) for closed distal femur fractures. Methods: This study was a prospective, randomized controlled clinical trial. Between October 2018 and June 2020, 160 closed distal femur fracture patients who were prepared for ORIF were prospectively randomized into two groups: a CSD group with the mean age of 57.91 ± 14.38 years (32 [40%] men and 48 [60%] women) and a non‐CSD group with the mean age of 59.73 ± 17.55 years (27 [34%] men and 54 [66%] women). Wound visual analogue scale (VAS) pain scores, peri‐wound skin temperature, hematocrit (Hct), hemoglobin (Hb) concentrations, hidden blood loss (HBL), dressing change, period of wound oozing, postoperative blood transfusion, and length of postoperative hospital stay were recorded. Postoperative wound complications, namely wound infections, wound haematoma, wound dehiscence, erythema of wound, and lower limb deep vein thrombosis (DVT) were collected. All the patients were administrated by a single surgical team and followed up for 1 month after the ORIF. Results: The patients without CSD were identified with lower peri‐wound skin temperature and wound VAS pain scores during the first three postoperative days (36.69 ± 0.33 vs 36.86 ± 0.38 °C, P = 0.002; 1.88 ± 0.82 vs 3.15 ± 1.15, P = 0.000). However, both the peri‐wound skin temperature and wound VAS pain scores did not differ significantly between the two groups on the fifth postoperative day. In addition, patients with CSD had a longer length of postoperative hospitalization time (11.45 ± 5.95 vs 9.78 ± 4.64 days, P = 0.049). There was no statistically significant difference between CSD and non‐CSD groups within 1 month after the ORIF regarding blood loss, period of wound oozing, and postoperative complications, such as incidence of wound infection, haematoma, erythema, dehiscence, and lower limb DVT. Conclusion: Prophylactic CSD after primary ORIF for closed distal femur fractures not only had no significant advantage to minimize blood loss and wound complications, but increased local inflammation and postoperative hospital stay, and thus we suggest that prophylactic CSD after primary ORIF for closed distal femur fractures is not recommended for optimized clinical pathways and accelerated recovery. [ABSTRACT FROM AUTHOR]

The trailing suction hopper dredger (TSHD) is a ship that excavates sediments from the sea bottom while sailing. Soil properties have a strong effect on the dredging process. The parameter with the greatest importance is the real-time soil grain diameter dm. This, however, cannot be directly measured by available sensors. In this paper, an alternative method is proposed to solve this problem. A new estimation method is developed on the basis of an existing sedimentation model and measuring system data. The loading process with several grain diameters is simulated to perform a sensitivity analysis of soil type. Simulation results show that the dredging efficiency is strongly affected by fine soil. This soil-related estimation problem is solved with a continuous-discrete feedback particle filter (CD-FPF), which is a recently developed filter for a CD time system. For comparison, a bootstrap particle filter (BPF) is also used to simulate the steplike changes in dm in both the no-overflow and constantvolume loading phases. The results show that the CD-FPF outperforms the BPF in terms of accuracy and applicability. Thus, it is recommended to be applied in the estimator of artificial intelligence (AI) dredging systems. [ABSTRACT FROM AUTHOR]

Resveratrol, a natural phenolic compound, provides neuroprotective effects, however, the specific mechanisms of action remain to be elucidated. The purpose of the present study was to examine the neuroprotective effect of resveratrol on spinal cord injury (SCI) and the potential molecular mechanisms of action. A rat model of SCI was induced using Allen's method, and resveratrol (100 mg/kg) was intraperitoneally injected 1 day following surgery. The recovery of neurological function was assessed using the Basso, Beattie, Bresnahan scoring system and an inclined plane test. The concentrations of pro‑ and anti‑inflammatory factors were measured using ELISA. The expression and location of autophagy markers were measured using western blot and immunofluorescence analyses. The results suggested that resveratrol administration resulted in functional improvement of locomotor activity and reduced neuroinflammation following the induction of SCI. In addition, autophagy was activated following SCI, as demonstrated by the significantly increased ratio of microtubule‑associated protein light chain 3 (LC3)‑II/LC3‑I and expression of Beclin‑1 in the injured spinal cord. Of note, the enhancement of phosphorylated (p)‑AMP‑activated protein kinase (AMPK) and the reduction of p‑mammalian target of rapamycin (mTOR) following SCI indicated that the SCI‑induced activation of autophagy was associated with the AMPK/mTOR signaling pathway. Resveratrol treatment further enhanced the activation of autophagy via the AMPK/mTOR pathway following SCI. By contrast, the autophagic inhibitor, 3‑methyladenine, partially inhibited the neuroprotective effects of resveratrol treatment. Together, these findings suggested that resveratrol promoted functional recovery and inhibited neuroinflammation through the activation of autophagy mediated by the AMPK/mTOR pathway following SCI. [ABSTRACT FROM AUTHOR]

In free Galerkin methods, the weight function is very important. Through Gauss function, this article uses the truncated Gauss function as the weight function, combining with least square approximation method to solve one-dimensional partial differential equations. The results show that the method is feasible and the calculation accuracy has been significantly improved. [ABSTRACT FROM AUTHOR]