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Camera calibration is the most important aspect of computer vision research. To address the issue of insufficient precision, therefore, a high precision calibration algorithm for binocular stereo vision camera using deep reinforcement learning is proposed. Firstly, a binocular stereo camera model is established. Camera calibration is mainly divided into internal and external parameter calibration. Secondly, the internal parameter calibration is completed by solving the antihidden point of the camera light center and the camera distortion value of the camera plane. The deep learning fitting value function is used based on the internal parameters. The target network is established to adjust the parameters of the value function, and the convergence of the value function is calculated to optimize reinforcement learning. The deep reinforcement learning fitting structure is built, the camera data is entered, and the external parameter calibration is finished by continuous updating and convergence. Finally, the high precision calibration of the binocular stereo vision camera is completed. The results show that the calibration error of the proposed algorithm under different sizes of checkerboard calibration board test is only 0.36% and 0.35%, respectively, the calibration accuracy is high, the value function converges quickly, and the parameter calculation accuracy is high, the overall time consumption of the proposed algorithm is short, and the calibration results have strong stability.

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BACKGROUND: This study aims to investigate the clinical efficacy of transoral laser microsurgery and open partial laryngectomy (OPL) in treating T1-2 laryngeal cancer. METHODS: A retrospective analysis was conducted of 182 patients with T1-2 cancer with anterior vocal commissure (AVC) involvement. The local control (LC), disease-free survival (DFS) and overall survival (OS) rates at 5-year follow-up and the influencing factors were analyzed. RESULTS: No significant difference was observed in the LC or DFS rates between the two groups at 3- and 5-year follow-up. No significant difference was found between the two groups with T1-stage disease. The 5-year LC rates were significantly different from patients with grade 3 or 4 tumors on indirect laryngoscopy and patients with class III or IV tumors on the modified Mallampati test (MMT) (log-rank test: χ2=8.037, P=0.005). The 3-year LC rate of OPL in the depth of pathological infiltration (3-5 mm) group was found to be significantly higher than that of TLM. Significant differences in pathological infiltration depth (3-5 mm) existed between the two groups (log-rank test: χ2=5.786, P=0.016). CONCLUSIONS: T1 lesions are generally limited and superficial, and laser surgery can be well-controlled. For patients with difficult airway exposure, surgeons should have extensive surgical experience and skills. It is recommended that a variety of equipment should be ready so that surgeons can convert to open surgery at any time. For patients with a deep infiltration depth, surgeons should examine laryngoscopy imaging results before surgery.

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The present study endeavored to develop orodispersible films (ODFs) containing 30 mg racecadotril for pediatric use, which focuses on improving the compliance of pediatric patients and reducing risk of choking. The challenge of this study is to prepare high drug loading ODFs with successful mechanical and physicochemical properties. Compatibilities between drug and different polymers (hydroxypropyl methylcellulose, HPMC; polyvinyl alcohol, PVA; low-substituted hydroxypropyl cellulose, L-HPC; pullulan, PU) were investigated to select stable and safe film-forming polymers. Afterwards, the study explored the maximum amount of racecadotril incorporated into PVA films and PU films. Subsequently, disintegrant (Lycoat RS720, 4-10%, w/w) and plasticizers (glycerol, 2-6%, w/w) were investigated to reduce disintegration time of PVA films and enhance the flexibility of PU films, respectively. Formulation characteristics (appearance, tensile strength, percent elongation, disintegration time, drug content, weight, thickness, pH value, moisture content, moisture uptake, and Q5min) of prepared ODFs were examined to obtain the optimal compositions of racecadotril ODFs. Differential scanning calorimetry (DSC) study, powder X-ray diffraction (XRD) study, Fourier transform infrared (FTIR) study, comparative in vitro dissolution study, and pharmacokinetic study in Beagle dogs of optimized racecadotril ODFs were then conducted. Eventually, ODFs containing 50% racecadotril, 38% PVA, 7% Lycoat RS720, 2% sucralose, 2% apricot, and 1% titanium dioxide could achieve desirable mechanical properties, disintegrating within a few seconds and releasing more than 85% drug within 5 min in four dissolution media. An in vivo study showed optimized racecadotril ODF and Hidrasec were bioequivalent in Beagle dogs. In summary, ODFs containing 30 mg racecadotril were successfully prepared by solvent casting method, and it was suitable for the administration to the pediatric patients.

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The aim of this research was to develop and assess a new dissolution apparatus for orodispersible films (ODFs). The new apparatus was based on a flow-through cell design which requires only a limited amount of dissolution medium and can automatically collect samples in short-time intervals. Compared with the dissolution method in Chinese Pharmacopeia, our method simulated the flow condition of the oral cavity and resulted in reproducible dissolution data and remarkably discriminating capability. Therefore, we concluded that the proposed dissolution method was particularly suitable for evaluating the dissolution of ODFs and should also be applicable to other fast-dissolving solid dosage forms.

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Organic and mineral soil horizons from forests in 30 mountains across China were analysed for polychlorinated biphenyl (PCB). Soil total organic carbon (TOC) content was a key determinant of PCB distribution explaining over 90% of the differences between organic and mineral soils, and between 30% and 60% of the variance along altitudinal and regional transects. The residual variance (after normalization by TOC) was small. Tri- to tetra-CB levels were higher in the South in relation to high source density and precipitation. Heavier congeners were instead more abundant at mid/high-latitudes where the advection pattern was mainly from long range transport. This resulted in a latitudinal fractionation opposite to theoretical expectations. The study showed that exposure to sources with different characteristics, and possibly accumulation/degradation trends of different congeners in soils being out-of-phase at different latitudes, can lead to an unsteady large scale distribution scenario conflicting with the thermodynamic equilibrium perception.

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