To determine the distribution pattern of the threshing and separating device, the simulation experiment on the distribution pattern of our self-designed drum-shape bar-tooth longitudinal axial flow threshing and separating device was carried out with the help of the EDEM software, by which the axial and radial distribution curve of the threshed mixture along the cylinder was acquired. The three-dimensional distribution of the mass of the threshed mixture was drawn by using the Matlab software, and the bench test was carried out on the self-built small-scale longitudinal axial flow threshing cylinder performance test platform, which was consistent with the simulation conditions. The results showed that the axial and radial distribution of the threshed mixture was uneven, and the axial distribution of the threshed mixture decreased gradually, which was mainly distributed in the first third section of the cylinder. The distribution of the threshed mixture along the radial area of the cylinder was gradually decreasing at first and then increasing, i.e., the total mass of the threshed mixture on the left and right sides was higher than that of the middle area, which was basically consistent with the simulation results. The research can provide reference for the optimization of structural parameters of threshing and separating device and cleaning system.

The first seasonal harvest technology of ratoon rice requires the least rolling with suitable stubble height required by agronomy when the ratoon rice is nearly mature. Mechanized harvesting in the first season of ratoon rice needs to finish harvesting, threshing, cleaning, straw treatment, grain transportation, grain collection and other processes at one time with a low rolling rate and low rolling degree. Limited by the production conditions such as wet and soft fields, and wet, thick and strong straw, harvest technology with high efficiency and a low rolling rate of ratoon rice in the first season has become the key technology and research focus affecting the yield of ratoon rice. In this paper, we analyzed the planting and popularization of ratoon rice in China, summarized the planting mode and agronomic characteristics of ratoon rice, highlighted the research status of mechanized harvesting equipment for the first season of ratoon rice, especially the specialized harvesters, and illustrated in detail the technical characteristics and research trends of key segments such as chassis, header, and processes such as threshing and cleaning, and straw and stubble treatment of ratoon rice harvesters. In addition, we summarized the application status and value of lightweight technology, performance monitoring and fault diagnosis technology, grain quality detection technology and automatic navigation technology of mechanized harvest in the first season, explained the main problems and reasons affecting the development of ratoon rice harvest mechanization in China, and illustrated the prospect of its research focus and tendency.

BACKGROUNDVagus nerve stimulation (VNS) has been approved for the treatment of refractory partial epilepsy in adults and children over 12 years of age. Later on, its application expanded to include younger children and other types of epilepsy. We report our experience with this treatment modality for refractory epilepsy in Saudi Arabia.DESIGN AND SETTINGSOpen-label, uncontrolled, retrospective study of patients with refractory epilepsy, who were treated with VNS in a tertiary care hospital from January 2010 to June 2013.PATIENTS AND METHODSCollected data included 26 patients’ demographics, epilepsy characteristics, seizure frequency, and treatment history. Patients with a follow-up duration of minimum 12 months were included in the analysis. The examined outcome measures were seizure reduction rates, antiepileptic drugs (AEDs) burden, and impact on patients’ quality of life (QOL).RESULTSOnset of seizures was from birth to 30 years. Patients’ ages at VNS implantation ranged from 4 to 38 years (18.9 [8.7] years). Epilepsy was classified as focal in 8 patients (30%), multifocal in 9 patients (35%), and generalized in 9 patients (35%). The average number of AEDs failed before VNS was 4.2 (1.4). Greater than 50% seizure reduction was achieved in 50% of patients at 3 months, 67% at 6 months, 73% at 12 months, and 78% at 24 months. There was no significant reduction in AEDs burden during the same period. Subjective QOL improvement was reported by 72% of patients at 3 months, 83% at 6 months, 78% at 12 months, and 73% at 24 months after VNS. Minor adverse effects were reported in 27% of patients. One patient had the device replaced due to malfunction.CONCLUSIONThe experience with VNS in a single center in Saudi Arabia confirms that it is a safe and effective adjunctive therapy for refractory epilepsy in adult and pediatric patients.