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Magnesium alloy has the advantages of low density, good damping and noise reduction and good electrical conductivity. It is the lightest metal structural material in applications. However, they are easily corroded due to the low potential of magnesium alloy electrodes, which limits their wide application in industry. At present, surface coating protection technology is one of the most effective methods to improve the corrosion resistance of magnesium alloys. Graphene oxide (GO) has excellent thermal, mechanical and barrier properties, and has broad application prospects in metal protection. GO-based composite coatings can provide a good physical barrier to corrosive media and have become one of the candidate materials for anti-corrosion coatings. In this article, the solutions were proposed for the limitations of single-component GO nanosheets, such as agglomeration and poor compatibility. The preparation methods, types and corrosion protection research progress of GO composite coatings were mainly summarized and its protection mechanism was analyzed in depth. Finally, the future development trend of GO application of magnesium alloy surface corrosion protection coating were prospected. The preparation methods and types of GO composite coatings on magnesium alloys were mainly described. The research progress and corrosion protection mechanism of GO coating on magnesium alloy were summarized.

The aim of this study is to develop and verify a magnetic resonance imaging (MRI)-based radiomics model for predicting the microvascular invasion grade (MVI) before surgery in individuals diagnosed with nodular hepatocellular carcinoma (HCC). Methods: A total of 198 patients were included in the study and were randomly stratified into two groups: a training group consisting of 139 patients and a test group comprising 59 patients. The tumor lesion was manually segmented on the largest cross-sectional slice using ITK SNAP, with agreement reached between two radiologists. The selection of radiomics features was carried out using the LASSO (Least Absolute Shrinkage and Selection Operator) algorithm. Radiomics models were then developed through maximum correlation, minimum redundancy, and logistic regression analyses. The performance of the models in predicting MVI grade was assessed using the area under the receiver operating characteristic curve (AUC) and metrics derived from the confusion matrix. Results: There were no notable statistical differences in sex, age, BMI (body mass index), tumor size, and location between the training and test groups. The AP and PP radiomic model constructed for predicting MVI grade demonstrated an AUC of 0.83 (0.75– 0.88) and 0.73 (0.64– 0.80) in the training group and an AUC of 0.74 (0.61– 0.85) and 0.62 (0.48– 0.74) in test group, respectively. The combined model consists of imaging data and clinical data (age and AFP), achieved an AUC of 0.85 (0.78– 0.91) and 0.77 (0.64– 0.87) in the training and test groups, respectively. Conclusion: A radiomics model utilizing-contrast-enhanced MRI demonstrates strong predictive capability for differentiating MVI grades in individuals with nodular HCC. This model could potentially function as a dependable and resilient tool to support hepatologists and radiologists in their preoperative decision-making processes. [ABSTRACT FROM AUTHOR]

Constipation is one of themost common chronic gastrointestinal problems. The estimated incidence of constipation in the United States is3% to 19% in general population.1,2 Patientswith head injuries, spinal cord injuries, pelvic fractures, lower extremity fractures ormultiple traumas require a long-term bed rest, during which the incidence of constipation reached as high as 50%.3,4 Constipation always brings inconvenience and tremendous suffering to patientsand strongly influences the recovery from primary disease. Irritants or lubricants can relieve the symptoms, but long-term application of them may lead to side effects like melanosis coli5 and cathartic colon6. The absorption of fat soluble vitamins is also affected.7 Polyethylene glycol 4000 (trade name: Forlax®), a long chain polymer with a high molecular weight, can conjugate withwater molecule through hydrogen bond to increase the water content and volume of stools, thereby, facilitate bowelmovement and defecation.8,9 It is neither absorbed nor metabolized in the digestive tract, hence it is highly safe and well tolerable. Thus, long-term medication of polyethylene glycol 4000 is conducive to the reconstruction of normal defecation pattern. Therefore, polyethylene glycol 4000 is now being widely used as the mainstay adult chronic functional constipation management.10,11 The aim of this study was to verify the efficacy and safety of polyethylene glycol 4000 on adult functional constipation of posttraumatic bedridden patients.

This paper develops a finite-difference time-domain (FDTD) approach suitable for modeling general antenna structures which include cylindrical dipoles. The medium averaging is a key factor of the method since the FDTD grid size is comparable to the dimensions of the antenna. It is essential in the FDTD calculation to account for the effective media seen by different electric field components. The input impedance calculated by the FDTD approach agrees well with the published results for a cylindrical dipole, although only one cell in the transverse direction is assigned as the metallic conductor. This FDTD approach is then used to model and analyze a novel broadband antenna which can be used in a borehole radar system for oil-field imaging while drilling. The antenna is essentially a horizontal cut on a metallic drill collar with a vertical cylindrical dipole placed across the cut and loaded at the ends. Based on the modeling results, we found that a proper resistive loading is the key in order to increase the bandwidth of the antenna and reduce ringing. When properly loaded, the antenna has a fairly flat input impedance ranging from 50 MHz to 600 MHz. The real part of the input impedance varies favorably around 75 [OMEGA]. In addition, the input impedance of the antenna is not very sensitive to the surrounding medium. The simulated antenna radiation of the electric field shows good azimuthal discrimination. For a lossless medium with a permittivity of [20[member of].sub.0] the front-back ratio climbs from around 15 dB at 100 MHz to about 45 dB at 600 MHz. Index Terms--Borehole radar, broadband antenna, finite difference, imaging while drilling, input impedance, subsurface.