Pool scrubbing is a potential method to removal aerosol under accident conditions of the nuclear power plants. The relative humidity of aerosol laden gas will increase when it passes through the liquid pool, which cause the hygroscopic growth of soluble aerosol. The hygroscopic growth of soluble aerosol can lead to the deviation of the size distribution of aerosol at the outlet of the liquid pool, resulting in a large error of the removal efficiency calculation results. In order to solve this problem, the size distribution of sodium chloride before and after penetrating the liquid phase was experimentally measured at gas flow rate of 4lpm and liquid height of 80 cm. Two methods of calculating the removal efficiency were proposed and compared. One method is directly calculating the removal efficiency by adding a diffusion drying tube before the aerosol laden gas enters the SMPS to reduce the relative humidity of sample gas below efflorescence point. Another method is modifying the aerosol size distribution and concentration curve by using the hygroscopic growth theory of soluble aerosols. The experiment results obtained by the two methods are in good agreement with the relative error within 20%.
In this paper, experiments were performed to investigate the flow loss characteristics of steam through different microchannels. The microchannels were assembled from stainless steel machined flange assemblies and pipes. The inlet pressure was 20 kPa, and the outlet pressure was adjusted between 5 kPa and 16 kPa (absolute pressure). The steam flow rate in microchannels was obtained by condensing the steam through a condenser coil, and the effects of microchannels of different structures and dimensions on the friction factor were studied by experiment. Experimental results show that the gas flow is not choking, even if the pressure ratio between the inlet and the outlet is as high as 4. In addition, a new correlation between the volumetric flow rate and the pressure difference was derived, and the error between the prediction curve and experimental data is within 20%. Besides, the microchannels’ structure effects on flow loss were investigated. The single most striking observation to emerge from the data comparison was that the gas flow phenomena in grooved channels with different hydraulic diameters were contrary. For microchannels with a hydraulic diameter of 300 µm, higher steam outlet velocities are found when steam flows in specially constructed microchannels. However, the opposite phenomena were observed in microchannels with a hydraulic diameter of 500 µm.
The correlations of epidemiological characteristics and clinical outcomes with different tumor sites in patients with intracranial typical site germinomas (ICTSGs) have not yet been well established. We analyzed ICTSGs using a multicenter database, focusing on its demographic, management patterns, and long-term survival outcomes.Patients diagnosed with ICTSGs were selected from the Surveillance, Epidemiology, and End-Results (SEER) database. Demographic information and management patterns of ICTSGs were extracted for data analysis stratified by different tumor sites. Kaplan-Meier curves were used to evaluate the survival outcome stratified by treatment, tumor site and tumor size.Among the 327 patients enrolled in the study, 16.21% had tumors located in the suprasellar region and 83.79% in the pineal region. The proportion of males was significantly higher among pineal germinomas (94.16 vs 66.04%; P < .001). Smaller tumors (<24 mm) were more common in the suprasellar region (37.74 vs 18.87%; P < .001). A higher percentage of patients with suprasellar germinomas underwent surgery. Radiotherapy (RT) and chemotherapy (CT) was, respectively, administered to 82.97 and 60.61% of patients during the treatment period, with no significant difference between suprasellar and pineal germinomas. CT plus RT was the most common treatment modality for both pituitary (30.19%) and pineal (33.94%) germinomas. Both RT and CT were associated with improved long-term survival. No survival difference was observed between suprasellar and pineal germinomas.Despite significant differences in epidemiology and management, pineal and suprasellar germinomas had a similar long-term clinical outcome.
MicroRNA‑21 (miR‑21) is a small non‑coding RNA that is differentially expressed during tooth development, particularly during amelogenesis. Although orthodontic tooth movement and the innate immune response are impaired, miR‑21 knockout mice demonstrate no obvious skeletal phenotype. However, the consequence of miR‑21 knockout on tooth phenotype and corresponding alveolar bone is unknown. The current study utilized landmark‑based geometric morphometrics to identify anatomical dissimilarities of the three lower and upper molars, and the corresponding alveolar bone, in miR‑21 knockout and wild‑type control mice. The anatomical structures were visualized by microcomputer tomography. A total of 36 and 38 landmarks were placed on mandibular and maxillary molars, respectively. For the alveolar bone, 16 landmarks were selected on both anatomical sites. General Procrustes analysis revealed significantly smaller molars and dimensions of the alveolar bone in the mandible of the miR‑21 knockout mice when compared with wild‑type controls (P=0.03 and P=0.04, respectively). The overall dimension of the mandible was reduced by the lack of miR‑21 (P=0.02). In the maxilla, the dimension of the alveolar bone was significant (P=0.02); however, this was not observed in the molars (P=0.36). Based on principal component analysis, no changes in shape for any of the anatomical sites were observed. Dental and skeletal jaw length were calculated and no prognathism was identified. However, the fluctuating asymmetry of the molars in the mandible and the maxilla was reduced in the miR‑21 knockout mice by 38 and 27%, respectively. Taken together, the results of the present study revealed that the molars in the mandible and the dimension of the respective alveolar bone were smaller in miR‑21 mice compared with wild‑type littermates, suggesting that miR‑21 influences tooth development.
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