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Compared with the forced oscillation test in a conventional wind tunnel test, the wind tunnel virtual flight test can achieve partially constrained dynamic motion of the model in the wind tunnel by manipulating the control surface deflection. In this paper, a new four-degree-of-freedom (4-DOF) wind tunnel virtual flight test device is established. Compared with the 3-DOF wind tunnel virtual flight test with rotation around the center of mass, the model adds vertical motion, enabling it to simulate free flight more realistically. In this paper, the nonlinear flight dynamics model of 4-DOF wind tunnel virtual flight test is established, the differences in dynamics characteristics between it and free flight are analyzed, and the identification model of aerodynamic derivatives based on 4-DOF wind tunnel virtual flight test is derived. To ensure the safety of the test, the longitudinal altitude control law as well as the sideslip and roll angle control laws in the lateral direction are designed. Finally, a set of aerodynamic parameter identification methods based on a 4-DOF wind tunnel virtual flight test is formed. The output error method is used to identify the aerodynamic derivatives of the test model, and the accuracy of the identification results is higher than that of the 3-DOF wind tunnel virtual flight test.

Objective: Acute mesenteric vein thrombosis (AMVT) is one of the acute abdominal diseases with onset, rapid progression, extensive intestinal necrosis, and requiring immediate surgical resection. The purpose of this study was to determine the risk factors of nosocomial intestinal resection in patients with AMVT. Methods: We retrospectively analyzed 64 patients with AMVT diagnosed by CTA in Affiliated Hospital of Kunming University of Science and Technology from January 2013 to December 2021. We compared patients who underwent intestinal resection (42 cases) with those who did not undergo intestinal resection (22 cases). The area under the ROC curve was evaluated and the forest map was drawn. Results: Among the 64 patients, 6 cases (9.38%) had a fever, 60 cases (93.75%) had abdominal pain, 9 cases (14.06%) had a history of diabetes, 8 cases (12.5%) had a history of deep vein thrombosis (DVT), and 25 cases (39.06%) had ascites suggested by B ultrasound or CT after admission. The mean age of all patients was (49.86±16.25) years. The mean age of patients in the enterectomy group was (47.71±16.20) years. The mean age of patients in the conservative treatment group (without enterectomy) was (53.95±15.90) years. In univariate analysis, there were statistically significant differences in leukocyte count (P=0.003), neutrophil count (P=0.001), AST(P=0.048), total bilirubin (P=0.047), fibrinogen (P= 0.022) and DD2 (P= 0.024) between the two groups. Multivariate logistic regression analysis showed that admission white blood cell count (OR=1.153, 95%CI: 1.039-1.280P =0.007) was an independent risk factor for intestinal resection in patients with AMVT. ROC curve showed that white blood cell count (AUC=0.759 95%CI: 0.620-0.897P =0.001 optimal threshold :7.815 sensitivity: 0.881 specificity: 0.636) had a good predictive value for emergency enterectomy for AMVT. Conclusions: Among patients with AMVT, patients with a higher white blood cell count at admission were more likely to have intestinal necrosis and require emergency enterectomy. This study is helpful for clinicians to accurately determine whether emergency intestinal resection is needed in patients with AMVT after admission, prevent further intestinal necrosis, and improve the prognosis of patients.

By processing the wind tunnel virtual flight test data, the movement process of the fly-by-wire civil aircraft can be realistically simulated. This paper establishes the dynamic model of the fly-by-wire civil aircraft wind tunnel virtual flight, designs the aircraft's longitudinal and lateral heading control laws, and verifies the correctness of the test results by comparing the simulation data with the flight test data. The digital filter is used to eliminate the noise of the test data, and the data compatibility test is performed by the output error method to eliminate the constant error and the scale factor error in the flight test data. A set of virtual flight data processing methods for fly-by-wire civil aircraft in wind tunnels has been formed.

Absorption of acetaminophen has been shown to be dissolution independent in human. Both extent and rate of absorption are important variables in the treatment of pain. The absorption of acetaminophen was studied by using two different acetaminophen tablets Depyretin(superscript ®) manufactured by Veterans Pharmaceutical Plant, Taiwan, and Scanol(superscript ®), manufactured by Scanpharm, Denmark. Both Scanol and Depyretin, each of 500 mg single dose, were administered orally to sixteen healthy young Chinese males with an one-week washout period in a randomized crossover design. Plasma samples used for acetaminophen measurement were taken prior to drug administration and at various times up to 12 hr subsequent to administration. The plasma samples were measured for acetaminophen concentration by an HPLC method. Values for areas under plasma concentration-time curve (extent of absorption), peak plasma concentration, time to peak concentration (rate of absorption), elimination rate constant, elimination half-life and oral clearance were compared for each preparation. Statistical analyses including ANOVA, power analysis and 90% confidence intervals after logarithmic transformation, showed no significant difference in the rate and extent of acetaminophen absorption between Scanol and Depyretin. Furthermore, in vivo absorption did not significantly correlate with in vitro dissolution performance in water. However, differences between these two formulations both in in vitro dissolution and in vivo absorption were not seen.

Computer-aided molecular design requires the ability to predict different molecular properties of interesting from using molecular structure. Traditional quantitative structural property relations were developed by extracting molecular features for predicting various properties. Hence domains of molecular features are different for predictions of different properties. In this work, the concept of a universal translator was used to develop a universal digital chemical space by translating and projecting the chemical representation SMILES to a high-dimensional space that can be collapsed into different molecular fingerprints. We demonstrated different kinds of pure component properties, such as electrical and thermodynamic properties can be predicted by a simple input of molecular structure, SMILES. This method eliminates the need to manually extract different molecular features for predicting different properties. The ability of model to predict sigma profiles also pave the way of prediction phase equilibria of mixtures using molecular structure only.

In this paper, a machine learning method is proposed to extract molecular features as floating-point numbers in a high dimensional space from the language-like description Simplified Molecular Input Line Entry Specification (SMILES). Principle component analysis showed that this method can successfully classify alkanes and alcohols and also the chain lengths of the molecular by their location in a three-dimensional feature space. A neural network model is build using the location of a compound in this high dimensional space as input to predict the “sigma-profile”, the charge distribution of the molecule near a perfect infinite conductor, which is calculated by quantum mechanics. The sigma-profile can be used in the COSMOSAC model for predicting thermodynamic properties such as activity coefficient. Preliminary results showed that an accurate neural work model with generalization ability can be developed.