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In order to study the corrosion behavior of L360 steel at the pipe wall of water-containing gathering and transportation pipelines under real flow conditions， a self-made cyclic flow corrosion test device was used.The electrochemical impedance spectroscopy and potentiodynamic scanning methods were used to analyze the corrosion electrochemical characteristics of L360 steel.The scanning electron microscope and three-dimensional optical microscope were used to analyze the corrosion micromorphology.Results showed that the average corrosion rate of the test piece increased with the increase of flow rate，and the local corrosion rate presented a trend of first decreasing and then increasing.Properly increasing the flow rate could slow down the local corrosion rate.After the loop was run for 4 h， a relatively complete corrosion product film began to form on the surface of the sample.When the flow rate reached 0.5 m/s， the corrosion product film on the pipe wall began to detach.For clean and smooth samples， the initial stage of corrosion belonged to extremely severe corrosion.

Traditional molecular dynamics simulation of biomolecules suffers from the conformational sampling problem. It is often difficult to produce enough valid data for post analysis such as free energy calculation and transition path construction. To improve the sampling, one practical solution is putting an adaptive bias potential on some predefined collective variables. The quality of collective variables strongly affects the sampling ability of a molecule in the simulation. In the past, collective variables were built with the sampling data at a constant temperature. This is insufficient because of the same sampling problem. In this work, we apply the standard weighted histogram analysis method to calculate the multi-ensemble averages of pairs of time-lagged features for the construction of both linear and nonlinear slow collective variables. Compared to previous single-ensemble methods, the presented method produces averages with much smaller statistical uncertainties. The generated collective variables help a peptide and a miniprotein fold to their near-native states in a short simulation time period. By using the method, enhanced sampling simulations could be more effective and productive. [ABSTRACT FROM AUTHOR]

IntroductionCongenital diaphragmatic hernia (CDH) repair is an area of active research. Large defects requiring patches have a hernia recurrence rate of up to 50%. We designed a biodegradable polyurethane (PU)-based elastic patch that matches the mechanical properties of native diaphragm muscle. We compared the PU patch to a non-biodegradable Gore-Tex™ (polytetrafluoroethylene) patch.MethodsThe biodegradable polyurethane was synthesized from polycaprolactone, hexadiisocyanate and putrescine, and then processed into fibrous PU patches by electrospinning. Rats underwent 4 mm diaphragmatic hernia (DH) creation via laparotomy followed by immediate repair with Gore-Tex™ (n = 6) or PU (n = 6) patches. Six rats underwent sham laparotomy without DH creation/repair. Diaphragm function was evaluated by fluoroscopy at 1 and 4 weeks. At 4 weeks, animals underwent gross inspection for recurrence and histologic evaluation for inflammatory reaction to the patch materials.ResultsThere were no hernia recurrences in either cohort. Gore-Tex™ had limited diaphragm rise compared to sham at 4 weeks (1.3 mm vs 2.9 mm, p = 0.003), but no difference was found between PU and sham (1.7 mm vs 2.9 mm, p = 0.09). There were no differences between PU and Gore-Tex™ at any time point. Both patches formed an inflammatory capsule, with similar thicknesses between cohorts on the abdominal (Gore-Tex™ 0.07 mm vs. PU 0.13 mm, p = 0.39) and thoracic (Gore-Tex™ 0.3 mm vs. PU 0.6 mm, p = 0.09) sides.ConclusionThe biodegradable PU patch allowed for similar diaphragmatic excursion compared to control animals. There were similar inflammatory responses to both patches. Further work is needed to evaluate long-term functional outcomes and further optimize the properties of the novel PU patch in vitro and in vivo.Level of evidenceLevel II, Prospective Comparative Study.

[Objective] To explore the effectiveness of the Revised Universal Soil Loss Equation (RUSLE) model in simulating soil erosion on slope surfaces during vegetation restoration in the Loess Plateau. [Methods] This study utilized rainfall-runoff and sediment data from ten runoff plots in Ansai Fangta small watershed in northern Shaanxi Province during 2016—2022. Utilizing various commonly used algorithms for RUSLE model factors specific to the Loess Plateau, a total of 144 combinations of factors were simulated to estimate soil erosion on restored slopes. The Nash-Sutcliffe efficiency coefficient (NSE) and root mean square error (RMSE) were used to evaluate the effectiveness of the model simulations. [Results] The results indicated that the simulated soil erosion on restored slopes using the 144 factor combinations ranged from -38.47 to 0.19 for NSE and from 1.92 to 12.65 t/(hm2·a) for RMSE, suggesting limited model performance. The selected algorithms for RUSLE model factors appeared to be inadequate for assessing soil erosion on slopes undergoing vegetation restoration. Further improvements are needed for the individual factors within the RUSLE model. When applying RUSLE model to simulate soil erosion on restored slopes in the Loess Plateau, it is recommended to utilize data with high temporal resolution to reduce errors in calculating the R-factor, and comprehensively consider the effects of soil physical and chemical properties such as soil organic matter content, soil particle size and aggregate structure and bulk density on K-factor, and the the effects of vegetation coverage, vegetation height, litter, and biological crust and C-factor, full consider to slopes steeper than 10° in refining the LS-factor. [Conclusion] The RUSLE model is not well-suited for simulating soil erosion in the context of vegetation restoration on abandoned slopes in the Loess Plateau.This study provides some reference for the research and development of soil erosion model and the application of RUSLE model on the slope of vegetation restoration in the Loess Plateau.

ObjectiveTo observe effects of electroacupuncture at Fengchi acupoint on expression of myosatellite cells, myogenic determining factor (MyoD), proliferating cell nuclear antigen (PCNA), Toll-like receptor 4 (TLR4), myeloid differentiation primary response gene 88 (MyD88) and nuclear factor-kappa B p65 (NF-κBp65) protein in rat with chronic cervical muscle injury, so as to explore possible mechanism of electroacupuncture in promoting the repair of chronic cervical muscle injury.MethodsTen Wistar rats were selected from 45 Wistar rats as blank group, and the remaining rats were divided into model group, electroacupuncture group (EA group) and meloxicam group according to random number table method, with 10 rats in each group (5 rats were unsuccessful in modeling). Chronic cervical muscle injury model of rats was established by long-term head flexion fixation and hypertonic saline injection. After 3 months of modeling, the morphological changes of posterior cervical muscle were observed by ultrasonic diagnostic detector. The success of modeling was verified by EMG. The EA group received electroacupuncture at Fengchi acupoint on both sides, 25 min each time, once a day, for 10 consecutive days as one course of treatment, with an interval of two days between courses of treatment, for 2 courses of treatment. After intervention, the posterior cervical muscle tissue of rats in each group was collected and the morphological changes of posterior cervical muscle tissue were observed under electron microscope. The protein contents of PCNA, MyoD, TLR4, MyD88 and NF-κBp65 were detected by immunohistochemistry.Results1) Morphological detection: Compared with the blank group, ultrasonic diagnosis results of the model group showed that tissue of posterior cervical muscle of rats was discontinuous and thickness was significantly narrower. Electrophysiological test results showed that amplitude and frequency of electromyographic significantly decreased in the model group. Compared with the blank group, muscle electron microscopy results of the model group showed that the arrangement of myofibrils was discontinuous, some mitochondria were swollen, and there were breaks between muscle fibers and muscle segments, and there were vacuoles. Compared with the model group, the EA group showed that myofibrils were clearly visible, cross-section of the myofibrils was punctured, sarcomere and serosa were intact, some mitochondria were swollen, and a few of them had vacuoles at the fracture of myofibrils. Myofibril structure of the meloxicam group was occasionally irregular, with vacuoles at the fracture of myofibril and a small amount of mitochondrial swelling. 2) Immunohistochemistry: Compared with the blank group, expression of PCNA and MyoD in model group was weakly positive, and protein expression of TLR4, MyD88 and NF-κBp65 significantly increased (PPPP>0.05).ConclusionThe treatment of chronic cervical muscle injury by electroacupuncture at Fengchi acupoint may be related to promoting the proliferation and differentiation of myosatellite cells, and the mechanism may be achieved by regulating the TLR4/MyD88/NF-κB signal transduction pathway.

Osteoporosis （OP） is a systemic bone disease and a common orthopedic disorder in elderly patients. High morbidity， disability and mortality rates and medical cost of OP bring huge burden to the patients and their family. Serine/threonine protein kinase（AMPK）/ mammalian target of rapamycin （mTOR） signaling pathway plays a significant role in cell metabolism and apoptosis. Traditional Chinese medicine monomer or compound can prevent and treat OP by regulating the expression levels of related factors through the AMPK/mTOR signaling pathway， whereas the specific mechanism remains elusive. In this article， the effect of AMPK/mTOR signaling pathway upon osteoblasts and osteoclasts， and the regulatory role of traditional Chinese medicine were reviewed， aiming to provide novel perspectives and ideas for prevention and treatment of OP.