Due to various technical issues,existing numerical weather prediction(NWP)models often perform poorly at forecasting rainfall in the first several hours.To correct the bias of an NWP model and improve the accuracy of ...Due to various technical issues,existing numerical weather prediction(NWP)models often perform poorly at forecasting rainfall in the first several hours.To correct the bias of an NWP model and improve the accuracy of short-range precipitation forecasting,we propose a deep learning-based approach called UNet Mask,which combines NWP forecasts with the output of a convolutional neural network called UNet.The UNet Mask involves training the UNet on historical data from the NWP model and gridded rainfall observations for 6-hour precipitation forecasting.The overlap of the UNet output and the NWP forecasts at the same rainfall threshold yields a mask.The UNet Mask blends the UNet output and the NWP forecasts by taking the maximum between them and passing through the mask,which provides the corrected 6-hour rainfall forecasts.We evaluated UNet Mask on a test set and in real-time verification.The results showed that UNet Mask outperforms the NWP model in 6-hour precipitation prediction by reducing the FAR and improving CSI scores.Sensitivity tests also showed that different small rainfall thresholds applied to the UNet and the NWP model have different effects on UNet Mask's forecast performance.This study shows that UNet Mask is a promising approach for improving rainfall forecasting of NWP models.展开更多
The pressure and horizontal particle velocity combined descriptions in the very low frequency acoustic field of shallow wa- ter integrated with the concept of effective depth of Pekeris wave- guide is proposed, especi...The pressure and horizontal particle velocity combined descriptions in the very low frequency acoustic field of shallow wa- ter integrated with the concept of effective depth of Pekeris wave- guide is proposed, especially the active component of the pressure and horizontal particle velocity cross-spectrum, also called ho- rizontal complex cross acoustic intensity, when only two normal modes are trapped in the waveguide. Both the approximate theo- retic analysis and the numerical results show that the sign of the horizontal complex cross acoustic intensity active component is independent of the range when vertically deployed receiving dual sensors are placed in appropriate depths, the sum of which is equal to the waveguide effective depth, so it can be used to tell whether the sound source is near the surface or underwater; while the range rate is expected to be measured by utilizing the sign distribution characteristic of the reactive component. The further robustness analysis of the depth classification algorithm shows that the existence of shear waves in semi infinite basement and the change of acoustic velocity profiles have few effects on the application of this method, and the seabed attenuation will limit the detection range, but the algorithm still has a good robustness in the valid detection range.展开更多
BACKGROUND Management of non-neurogenic,non-obstructive dysuria represents one of the most challenging dilemmas in urological practice.The main clinical symptom is the increase in residual urine.Voiding dysfunction is...BACKGROUND Management of non-neurogenic,non-obstructive dysuria represents one of the most challenging dilemmas in urological practice.The main clinical symptom is the increase in residual urine.Voiding dysfunction is the main cause of dysuria or urinary retention,mainly due to the decrease in bladder contraction(the decrease in contraction amplitude or duration)or the increase in outflow tract resistance.Sacral neuromodulation(SNM)has been used for>10 years to treat many kinds of lower urinary tract dysfunction.It has become increasingly popular in China in recent years.Consequently,studies focusing on nonneurogenic,non-obstructive dysuria patients treated by SNM are highly desirable.AIM To assess the outcome of two-stage SNM in non-neurogenic,non-obstructive dysuria.METHODS Clinical data of 54 patients(26 men,28 women)with non-neurogenic,nonobstructive dysuria treated by SNM from January 2012 to December 2016 in ten medical centers in China were retrospectively analyzed.All patients received two or more conservative treatments.The voiding diary,urgency score,and quality of life score before operation,after implantation of tined lead in stage I(test period),and during short-term follow-up(latest follow-up)after implantation of the implanted pulse generator in stage II were compared to observe symptom improvements.RESULTS Among the 54 study patients,eight refused to implant an implanted pulse generator because of the unsatisfactory effect,and 46 chose to embed the implanted pulse generator at the end of stage I.The conversion rate of stage I to stage II was 85.2%.The average follow-up time was 18.6 mo.There were significant differences between baseline(before stage I)and the test period(after stage I)in residual urine,voiding frequency,average voiding amount,maximum voiding amount,nocturia,urgency score,and quality of life score.The residual urine and urgency score between the test period and the latest follow-up time(after stage II)were also significantly different.No significant differences were observed for other parameters.No wound infection,electrode breakage,or other irreversible adverse events occurred.CONCLUSION SNM is effective for patients with non-neurogenic,non-obstructive dysuria showing a poor response to traditional treatment.The duration of continuous stimulation may be positively correlated with the improvement of residual urine.展开更多
BACKGROUND Emerging studies indicate the critical involvement of microorganisms,such as Epstein-Barr virus(EBV),in the pathogenesis of inflammatory bowel disease(IBD).Immunosuppressive therapies for IBD can reactivate...BACKGROUND Emerging studies indicate the critical involvement of microorganisms,such as Epstein-Barr virus(EBV),in the pathogenesis of inflammatory bowel disease(IBD).Immunosuppressive therapies for IBD can reactivate latent EBV,complicating the clinical course of IBD.Moreover,the clinical significance of EBV expression in B lymphocytes derived from IBD patients’intestinal tissues has not been explored in detail.AIM To explore the clinical significance of latent EBV infection in IBD patients.METHODS Latent EBV infection was determined by double staining for EBV encoded RNA and CD20 in colon specimens of 43 IBD patients who underwent bowel resection.Based on the staining results,the patients were divided into two groups,according to their latent EBV infection states-negative(n=33)and positive(n=10).Illness severity of IBD were assigned according to Crohn’s disease activity index(ulcerative colitis)and Mayo staging system(Crohn’s disease).The clinicpathological data were analyzed between the two different latent EBV groups and also between the mild-to-moderate and severe disease groups.RESULTS Systolic pressure(P=0.005),variety of disease(P=0.005),the severity of illness(P=0.002),and pre-op corticosteroids(P=0.025)were significantly different between the EBV-negative and EBV-positive groups.Systolic pressure(P=0.001),variety of disease(P=0.000),pre-op corticosteroids(P=0.011)and EBV infection(P=0.003)were significantly different between the mild-to-moderate and severe disease groups.CONCLUSION IBD patients with latent EBV infection may manifest more severe illnesses.It is suggested that the role of EBV in IBD development should be further investigated,latent EBV infection in patients with serious IBD should be closely monitored,and therapeutic course should be optimized.展开更多
基金jointly supported by the National Natural Science Foundation of China(Grant No.U1811464)the Hydraulic Innovation Project of Science and Technology of Guangdong Province of China(Grant No.2022-01)the Guangzhou Basic and Applied Basic Research Foundation(Grant No.202201011472)。
文摘Due to various technical issues,existing numerical weather prediction(NWP)models often perform poorly at forecasting rainfall in the first several hours.To correct the bias of an NWP model and improve the accuracy of short-range precipitation forecasting,we propose a deep learning-based approach called UNet Mask,which combines NWP forecasts with the output of a convolutional neural network called UNet.The UNet Mask involves training the UNet on historical data from the NWP model and gridded rainfall observations for 6-hour precipitation forecasting.The overlap of the UNet output and the NWP forecasts at the same rainfall threshold yields a mask.The UNet Mask blends the UNet output and the NWP forecasts by taking the maximum between them and passing through the mask,which provides the corrected 6-hour rainfall forecasts.We evaluated UNet Mask on a test set and in real-time verification.The results showed that UNet Mask outperforms the NWP model in 6-hour precipitation prediction by reducing the FAR and improving CSI scores.Sensitivity tests also showed that different small rainfall thresholds applied to the UNet and the NWP model have different effects on UNet Mask's forecast performance.This study shows that UNet Mask is a promising approach for improving rainfall forecasting of NWP models.
基金supported by the National Natural Science Foundation of China(1140440611374072)
文摘The pressure and horizontal particle velocity combined descriptions in the very low frequency acoustic field of shallow wa- ter integrated with the concept of effective depth of Pekeris wave- guide is proposed, especially the active component of the pressure and horizontal particle velocity cross-spectrum, also called ho- rizontal complex cross acoustic intensity, when only two normal modes are trapped in the waveguide. Both the approximate theo- retic analysis and the numerical results show that the sign of the horizontal complex cross acoustic intensity active component is independent of the range when vertically deployed receiving dual sensors are placed in appropriate depths, the sum of which is equal to the waveguide effective depth, so it can be used to tell whether the sound source is near the surface or underwater; while the range rate is expected to be measured by utilizing the sign distribution characteristic of the reactive component. The further robustness analysis of the depth classification algorithm shows that the existence of shear waves in semi infinite basement and the change of acoustic velocity profiles have few effects on the application of this method, and the seabed attenuation will limit the detection range, but the algorithm still has a good robustness in the valid detection range.
基金Supported by National Key Research and Development Program of China,No.2018YFC2002202.
文摘BACKGROUND Management of non-neurogenic,non-obstructive dysuria represents one of the most challenging dilemmas in urological practice.The main clinical symptom is the increase in residual urine.Voiding dysfunction is the main cause of dysuria or urinary retention,mainly due to the decrease in bladder contraction(the decrease in contraction amplitude or duration)or the increase in outflow tract resistance.Sacral neuromodulation(SNM)has been used for>10 years to treat many kinds of lower urinary tract dysfunction.It has become increasingly popular in China in recent years.Consequently,studies focusing on nonneurogenic,non-obstructive dysuria patients treated by SNM are highly desirable.AIM To assess the outcome of two-stage SNM in non-neurogenic,non-obstructive dysuria.METHODS Clinical data of 54 patients(26 men,28 women)with non-neurogenic,nonobstructive dysuria treated by SNM from January 2012 to December 2016 in ten medical centers in China were retrospectively analyzed.All patients received two or more conservative treatments.The voiding diary,urgency score,and quality of life score before operation,after implantation of tined lead in stage I(test period),and during short-term follow-up(latest follow-up)after implantation of the implanted pulse generator in stage II were compared to observe symptom improvements.RESULTS Among the 54 study patients,eight refused to implant an implanted pulse generator because of the unsatisfactory effect,and 46 chose to embed the implanted pulse generator at the end of stage I.The conversion rate of stage I to stage II was 85.2%.The average follow-up time was 18.6 mo.There were significant differences between baseline(before stage I)and the test period(after stage I)in residual urine,voiding frequency,average voiding amount,maximum voiding amount,nocturia,urgency score,and quality of life score.The residual urine and urgency score between the test period and the latest follow-up time(after stage II)were also significantly different.No significant differences were observed for other parameters.No wound infection,electrode breakage,or other irreversible adverse events occurred.CONCLUSION SNM is effective for patients with non-neurogenic,non-obstructive dysuria showing a poor response to traditional treatment.The duration of continuous stimulation may be positively correlated with the improvement of residual urine.
基金Supported by Clinical and Translational Medicine Research Foundation of Chinese Academy of Medical Sciences,No. 2020-I2M-C&T-B-038Capital Health Research and Development of Special Project,No. 2022-1-2181Group Medical Aid Project of the Tibet Autonomous Region Natural Science Foundation,No. XZ2020ZR-ZY28[Z]
文摘BACKGROUND Emerging studies indicate the critical involvement of microorganisms,such as Epstein-Barr virus(EBV),in the pathogenesis of inflammatory bowel disease(IBD).Immunosuppressive therapies for IBD can reactivate latent EBV,complicating the clinical course of IBD.Moreover,the clinical significance of EBV expression in B lymphocytes derived from IBD patients’intestinal tissues has not been explored in detail.AIM To explore the clinical significance of latent EBV infection in IBD patients.METHODS Latent EBV infection was determined by double staining for EBV encoded RNA and CD20 in colon specimens of 43 IBD patients who underwent bowel resection.Based on the staining results,the patients were divided into two groups,according to their latent EBV infection states-negative(n=33)and positive(n=10).Illness severity of IBD were assigned according to Crohn’s disease activity index(ulcerative colitis)and Mayo staging system(Crohn’s disease).The clinicpathological data were analyzed between the two different latent EBV groups and also between the mild-to-moderate and severe disease groups.RESULTS Systolic pressure(P=0.005),variety of disease(P=0.005),the severity of illness(P=0.002),and pre-op corticosteroids(P=0.025)were significantly different between the EBV-negative and EBV-positive groups.Systolic pressure(P=0.001),variety of disease(P=0.000),pre-op corticosteroids(P=0.011)and EBV infection(P=0.003)were significantly different between the mild-to-moderate and severe disease groups.CONCLUSION IBD patients with latent EBV infection may manifest more severe illnesses.It is suggested that the role of EBV in IBD development should be further investigated,latent EBV infection in patients with serious IBD should be closely monitored,and therapeutic course should be optimized.
