Inverse design of metasurfaces with customized transmission characteristics of frequency band based on generative adversarial networks.

In recent years, deep learning (DL) has demonstrated significant potential in the inverse design of metasurfaces, and the generation of metasurfaces with customized transmission characteristics of frequency band remains a challenging and underexplored area. In this study, we propose a DL-assisted method for the inverse design of transmissive metasurfaces. The method consists of a generative adversarial network (GAN)-based graph generator, an electromagnetic response predictor, and a genetic algorithm optimizer. By integrating these components, we can obtain customized metasurfaces with desired transmission characteristics of frequency band. We demonstrate the effectiveness of the proposed method through examples of inverse-designed three-layer cascaded transmissive metasurfaces with wideband, dual-band, and stopband responses in the 8∼12 GHz frequency range. Specifically, we realize three different types of dual-band metasurfaces, namely double-wide, front-wide and rear-narrow, and front-narrow and rear-wide configurations. Additionally, we analyze the accuracy and reliability of the inverse design method by employing data from the training dataset, self-defined objectives, and bandwidth-reduced target responses scaled from the wideband type as design inputs. Quantitative evaluation is performed using metrics such as mean absolute error and average precision. The proposed method successfully achieves the desired effect as intended.

Rex Shunt as a Treatment of Type II Abernethy Malformation with Severe Dysplasia of Portal Vein.

BACKGROUND: Ligation of abnormal portosystemic shunt has been used to treat type II Abernethy malformation, but it may not be suitable for all patients. In this study, Rex shunt was carried out to manage type II Abernethy malformation with portal venous dysplasia. The outcomes are evaluated retrospectively. METHODS: Between June 2014 and January 2015, 2 boys (age: 4.8 and 12.8 years, respectively) with type II Abernethy malformation underwent Rex shunt with ligation of inferior mesenteric vein (IMV). The portal venous pressures were measured intraoperatively to decide the extent of inferior mesenteric venous ligation. An ileal vein (6 mm in diameter) and a venae sigmoideae (7 mm in diameter) were interposed between the left portal vein and superior mesenteric vein, respectively. To minimize postoperative portal hypertension, the IMV was partially ligated. Five months later, the IMV was completely ligated in a second operation because of persistent bloody stool and anemia (hemoglobin < 100 g/L). RESULTS: The duration of the operations was 180 and 240 min. The extrahepatic portal pressure increased after bypass, but the portal pressure was less than 24 cm H2O in both patients. The fecal blood loss and frequency of hemafecia decreased after surgery. The bypass vein was patent, and the portal blood flow was shown increased on postoperative ultrasound and computed tomography. There was no hypersplenism and esophageal gastric varices. CONCLUSIONS: The surgical management of Abernethy type II malformation should be individualized. Rex shunt with ligation of portosystemic shunt is feasible and effective in patients with severe dysplasia of portal vein.

Spleen-preserving proximal splenic-left intrahepatic portal shunt for the treatment of extrahepatic portal hypertension in children.

PURPOSE: The Rex shunt has been employed successfully to treat patients with extrahepatic portal hypertension. In the conventional Rex shunt, the internal jugular vein is used as a venous graft. Inevitably, such a procedure requires neck exploration and sacrifice of the internal jugular vein. The authors describe a novel adaptation of spleen-preserving spleno-Rex bypass, successfully carried out in children with extrahepatic portal hypertension. METHODS: The mean age of the four patients (1 boy, 3 girls) was 46 months at the time of operation. All children had a history of upper gastrointestinal bleeding, and suffered from splenomegaly and hypersplenism. Spleen-preserving proximal splenic-left intrahepatic portal shunt was performed in all patients. The splenic artery and vein were ligated at the splenic hilum, and the splenic vein was completely separated from the bed of the pancreas to its junction with the inferior mesenteric vein. The freed splenic vein was anastomosed to left portal vein. The short gastric and left gastroepiploic vessels were kept intact to supply and drain the spleen. All patients were followed-up for 7-33 months (median: 21.5 months). RESULTS: The spleen-preserving spleno-Rex bypass was successfully performed in all 4 patients. The median operative time was 225 min (range: 215-260 min). One patient received blood transfusion, and the postoperative length of hospital stay varied from 4 to 6 days (median: 4.5 days). Intraoperative portal venous angiography demonstrated the patency of the shunt in all patients. Postoperatively, the complete blood count normalized and the biochemistry tests were within normal range. Postoperative ultrasound confirmed shunt patency and satisfactory flow in the proximal splenic-portal shunt in each patient. The size of the spleen decreased and there was no recurrence of variceal bleeding. CONCLUSIONS: The spleen-preserving spleno-Rex bypass is a viable option to treat EHPVO in children.

Single-incision laparoscopic excision of pancreatic tumor in children.

PURPOSE: Single-incision laparoscopic surgery (SILS) as a surgical approach in treatment of pancreatic disease has recently been reported in adults. However, its application in pancreatic surgery in children is limited. In this article, we report our preliminary experience of SILS in children with pancreatic disease. METHODS: Three children with pancreatic tumor underwent single-incision laparoscopic partial pancreatectomy between July 2011 and August 2013. Two of three children were girls, and one was a boy. The ages ranged from 2 to 10 months, with an average age of 6.7 months. RESULTS: All operations were successfully performed. There was no conversion to the conventional multi-incision surgery. The mean operation time of the 3 cases was 153.3 minutes (range 120-200 minutes). The postoperative hospital stay was 7 days. The drainage tubes were kept for 3 to 4 days after surgery. There was no pancreatic juice leak in this case series. All patients were followed up and there was no recurrence. CONCLUSIONS: Single-incision laparoscopic partial pancreatectomy for children with pancreatic tumor is feasible.

Transanal rectal mucosectomy and partial internal anal sphincterectomy for Hirschsprung's disease.

PURPOSE: Hirschsprung-associated enterocolitis (HAEC) is a serious complication of Hirschsprung's disease (HD), with generalized sepsis and high mortality rate. Although the surgical correction of HD is mostly successful, challenges remain in the management of children with repeated episodes of enterocolitis. The authors describe a novel modification of transanal rectal mucosectomy and partial internal anal sphincterectomy (TRM-PIAS) for HD. METHODS: One hundred twenty-seven HD children aged from 8 days to 16 years who successfully underwent TRM-PIAS were reviewed. TRM-PIAS was carried out circumferentially along the anorectal line. Anterior dissection was conducted between the rectal submuscosal layer and the rectal muscular sleeve. The posterior dissection was performed along the plane between internal and external anal sphincters. Normal colon was pulled through and anastomosed to anal mucosa. Aganglionic segment, rectal mucosa, part of internal anal sphincter and posterior rectal muscular cuff were removed. Twenty-five age-matched children without defecation dysfunction were used as the control group in the study of anal resting pressure. RESULTS: Patients were followed up for 6-12 years (median: 8.2 years). The median age at last follow-up was 12.2 years (7.2-20.1 years). The incidence of enterocolitis decreased from 33.9% (43/127) preoperatively to 1.6% (2/127) postoperatively (P<0.01). The incidence of constipation decreased from 100% (127/127) preoperatively to 2.4% (3/127) postoperatively (P<0.01). Soiling rate on postoperative 1 month was 32.3%. It gradually decreased to 1.6% 6 months later. Anorectal manometries showed that mean anal resting pressure was significantly reduced from 37.9±12.5 mm Hg preoperatively to 20.2±6.4 mm Hg on postoperative 1 month and 24.8±9.9 mm Hg on postoperative 6 months, which were similar to age-matched normal controls (27.9±9.6 mm Hg, P>0.05). CONCLUSIONS: TRM-PIAS is effective in treatment of HD. It is associated with low postoperative HD-associated enterocolitis.

Laparoscopic pancreaticojejunostomy for pancreatic ductal dilatation in children.

PURPOSE: The application of laparoscopic surgery in pancreatic surgery in children is limited. In this article, we describe laparoscopic pancreaticojejunostomy for children with congenital pancreatic ductal dilatation. METHODS: Four children with recurrent pancreatitis and pancreatic ductal dilatation underwent laparoscopic pancreaticojejunostomy between July 2009 and November 2011. Longitudinal incision of the dilated pancreatic ducts and side-to-side Roux-Y pancreaticojejunostomy were performed. RESULTS: Operative time ranged from 103 to 154 min, and blood loss was minimal. The average postoperative hospital stay was 4 to 6 days. There were no pancreatic leaks. None of the patients experienced recurrence of pancreatitis. CONCLUSIONS: Laparoscopic pancreaticojejunostomy for children with congenital pancreatic ductal dilatation is safe and effective.

Gastroportal shunt for portal hypertension in children.

PURPOSE: Extrahepatic portal venous obstruction is the most common cause of portal hypertension in children. The Rex shunt has been used successfully to treat patients with extrahepatic portal hypertension. In the conventional Rex shunt, the internal jugular vein is used as a venous graft. Inevitably, such a procedure requires neck exploration and sacrifice of internal jugular vein. The authors describe a novel adaptation of gastroportal shunt, successfully carried out in 8 children with extrahepatic portal hypertension. METHODS: The mean age of the 8 patients (6 boys and 2 girls) was 66.6 months at the time of operation. All children had portal hypertension. Seven had a history of upper gastrointestinal bleeding, and 4 had splenomegaly and hypersplenism. Gastroportal shunt was performed in all patients. The left gastric vein was mobilized and anastomosed to left portal vein. In 1 patient, the left gastric vein was not of adequate length and required a venous graft (the inferior mesenteric vein). All patients were followed up for 3 to 20 months (median, 9 months). RESULTS: The gastroportal shunt was successfully performed in all patients. The median operative time was 265 minutes (range, 205-360 minutes). Operative blood loss was 21 ± 7.4 mL, and the length of hospital stay varied from 9 to 19 days (median, 15 days). Intraoperative portal venous angiography demonstrated the patency of the shunt in all patients. Postoperatively, the complete blood count normalized, and the biochemistry tests were within reference range. Postoperative ultrasound confirmed shunt patency and satisfactory flow in the gastroportal shunt in each patient. The size of spleen decreased. There was no recurrence of variceal bleeding. CONCLUSIONS: The gastroportal shunt is an effective treatment of extrahepatic portal hypertension.

Laparoscopic excision of choledochal cyst and Roux-en-Y hepaticojejunostomy in symptomatic neonates.

PURPOSE: Choledochal cysts require surgical excision, preferably before the onset of cholangitis. Recently, it has become feasible to accomplish the excision laparoscopically in adults and older children. Yet, whether laparoscopic excision of choledochal cyst can be performed safely in symptomatic neonates with choledochal cyst is unclear. We herewith reviewed our experience of laparoscopic excision of choledochal cysts in neonates. METHODS: We managed 9 neonates with choledochal cysts between April 2003 and February 2007. The choledochal cysts were excised laparoscopically. The Roux-en-Y hepaticojejunostomy was fashioned extracorporeally by exteriorizing the jejunum through the extended umbilical port site. End-to-side anastomosis between the common hepatic duct stump and Roux loop was carried out intracorporeally. The patients were followed up for an average of 26 months. RESULTS: The patients presented with jaundice, pale stool, and deranged liver function tests. The diagnosis was confirmed with ultrasonography postnatally. The median operation time was 3.6 hours. There was no operative complication and no conversion. The blood loss was minimal. The recovery was uneventful, and the median hospital stay was 6 days. The liver function tests normalized 3 to 16 weeks postoperatively. No complication was detected at the follow-up visits. CONCLUSIONS: Our preliminary results show that laparoscopic excision of choledochal cyst and Roux-en-Y hepaticojejunostomy in neonates is both feasible and safe. It curtails further complication of the cysts and reverses the derangement of liver function. In addition, the laparoscopic approach minimizes surgical trauma.

Laparoscopic hepatojejunostomy for biliary atresia.

PURPOSE: The aim of this study was to evaluate the feasibility of laparoscopic hepatojejunostomy for types I and II biliary atresia (BA). MATERIALS AND METHODS: Between April 2003 and July 2007, 10 children with "correctable" types I and II BA were enrolled for the study. They presented with progressive jaundice, pale stools, and elevated aspartate transferase and alanine transferase levels. There were 6 girls and 4 boys, with ages ranging from 23 to 160 days (median,53). All BA had cysts of extrahaptic bile ducts. There were 6 type I and 4 were type II BA. The median diameter of the cysts was 1.5 cm (range, 1.0-1.8). All 10 children underwent laparoscopic cyst excision with Roux-en-Y hepatojejunostomy. Four trocars were inserted. The distal end of the cyst was resected.and a Rouxen-Y hepatojejunostomy was fashioned. The patients were followed up on median for 26 months (range, 4-51). RESULTS: The median duration of the operation was 3.0 hours (range, 2.4 - 3.2). There were no intraoperative complications. The blood loss was between 5 to 10 mL. Postoperatively, patients passed flatus after 18 hours(range, 16-28), and resumed oral intake in 20 hours (range, 16-30). Normal colored stools were passed after 3 days (range, 2-4). Jaundice started to disappear on postoperative day 10 (range, 7-16). In 6 cases, the total and the direct bilirubin were normalized on postoperative day 14-3 in 3 weeks. One patient had a persistent elevation of bilirubin. The postoperative course was uneventful in all patients. The median postoperable hospital stay was 7 days (range, 5-9). No postoperative complication was found at the follow-up visits. CONCLUSIONS: The laparoscopic Kasai' operation for children with type I or II biliary atresia is feasible, safe, and effective.

Total extrapleura sternal elevation for the correction of pectus excavatum in children.

PURPOSE: The aim of this study was to evaluate the efficacy and safety of the thoracoscopic total extrapleural approach of the Nuss procedure for the correction of pectus excavatum in children. MATERIALS AND METHODS: Under thoracoscopic guidance, an extrapleural tunnel was created by using a blunt dissector via a right thoracic incision. A steel bar was inserted in the entirely extrapleural tunnel. The bar was turned and fixed as in the standard Nuss procedure. RESULTS: The operations were completed successfully in all patients. The operating time ranged from 35 to 50 minutes (median, 45). The intraoperative blood loss was 2 to 3 mL. There was no pneumothorax or hydrothoraxin our series. All patients were followed up for 2-6 months, and the surgical outcomes were excellent. CONCLUSIONS: The extrapleura Nuss procedure under thoracoscopic guidance is a safe and less traumatic procedure for the correction of pectus excavatum.

Laparoscopic correction of biliary duct stenosis in choledochal cyst.

BACKGROUND/PURPOSES: Laparoscopy has been widely accepted as a technique for the excision of choledochal cyst, but there has been little experience using it as a therapeutic modality for hepatic duct stenosis. The aim of this study is to present our experiences in laparoscopic excision of biliary stenosis and Roux-en-Y reconstruction for patients with choledochal cysts. METHODS: Eight patients, 3 boys and 5 girls (ranged from 6 months to 12 years; median age, 3.6 years), with hepatic duct stenosis underwent laparoscopic excision of the cyst and ductoplasty, with a Roux-en-Y hepaticoenterostomy between July 2001 and January 2005. Seven of the 8 patients had common hepatic duct stenosis with intrahepatic duct dilatation, and 1 had right hepatic duct stenosis with proximal dilatation. Four ports were inserted for instruments of 3- and 5-mm sizes. Each patient underwent a laparoscopic cholangiography. The gallbladder and dilated bile ducts were completely excised. The strictures of the hepatic ducts were treated by ductoplasty. The cut end of the duct was widened by incising along the anterior wall of the hepatic duct after excision of the narrow segment. By using intraoperative bile duct endoscopy, the optimal level of resection of the common hepatic duct was determined safely without endangering the orifices of the hepatic ducts or leaving any redundant duct, and the stone debris in the bile duct was identified and washed out. The Roux-en-Y jejunal loop was fashioned extracorporeally by exteriorizing the jejunum through the umbilical incision (1.0-1.5 cm) and passed up retrocolically followed by an end-to-side hepaticojejunostomy. RESULTS: The median duration of the operation was 4.3 hours (3.8-5.6 hours). Intraoperative bleeding was minimal, with no patients requiring blood transfusion. In 7 of the 8 cases, postoperative hospital stay ranged from 4 to 6 days; the other case had bile leak, which was cured by draining for 26 days without surgical intervention. All the patients had been followed up for 6 to 51 months. They stayed asymptomatic and well with no delayed complication. CONCLUSIONS: Laparoscopically assisted hepatic ductoplasty is effective and safe for children with choledochal cyst. Bile duct endoscopy proved to be a valuable instrument in showing detailed variations of the biliary system and allowed a safe hepatic hilum exploration and accurate placed hepaticojejunal anastomosis.

The immunostimulatory effects of hot-water extract of Gelidium amansii via immersion, injection and dietary administrations on white shrimp Litopenaeus vannamei and its resistance against Vibrio alginolyticus.

The total haemocyte count (THC), phenoloxidase activity, and respiratory burst were examined when white shrimp Litopenaeus vannamei were immersed in seawater (34 per thousand) containing hot-water extract of red alga Gelidium amansii at 200, 400 and 600 mg l(-1), injected with hot-water extract at 4 and 6 microg g(-1) shrimp, and fed diets containing hot-water extract at 0, 0.5, 1.0 and 2.0 g kg(-1). These parameters increased significantly when shrimp were immersed in seawater containing hot-water extract at 400 and 600 mg l(-1) after 1h, when shrimp were injected with hot-water extract at 6 microg g(-1) shrimp after one day, and when shrimp were fed diets containing hot-water extract at 1.0 and 2.0 g kg(-1) after 14 days. Phagocytic activity and clearance efficiency were significantly higher for the shrimp that were fed diets containing hot-water extract at 1.0 and 2.0 g kg(-1) than those of shrimp that were fed diets containing hot-water extract at 0 and 0.5 g kg(-1) after 14 and 28 days. In a separate experiment, L. vannamei which had received hot-water extract via injection, or fed diets containing hot-water extract, were challenged after 3h or 28 days with V. alginolyticus at 2 x 10(6) cfu shrimp(-1) and 1 x 10(6) cfu shrimp(-1), respectively, and then placed in seawater. The survival of shrimp that were injected with hot-water extract at 6 microg g(-1) was significantly higher than that of control shrimp after 1 day, and the survival of shrimp fed diets containing hot-water extract at 0.5, 1.0 and 2.0 g kg(-1) increased significantly after 3 days as well as at the end of the experiment (6 days after the challenge), respectively. It was concluded that L. vannamei that were immersed in hot-water extract at 400 mg l(-1), injected with hot-water extract at 6 microg g(-1) shrimp, and fed hot-water extract of G. amansii at 2.0 g kg(-1) or less showed increased immune ability as well as resistance to V. alginolyticus infection.

The immunostimulatory effect of hot-water extract of Gracilaria tenuistipitata on the white shrimp Litopenaeus vannamei and its resistance against Vibrio alginolyticus.

The total haemocyte count (THC), phenoloxidase activity, respiratory burst, superoxide dismutase (SOD) activity, phagocytic activity and clearance efficiency to the pathogen Vibrio alginolyticus were examined in the white shrimp Litopenaeus vannamei (10.3+/-1.5 g) injected individually with hot-water extract of Gracilaria tenuistipitata at 4 or 6 microg g-1. L. vannamei receiving hot-water extract of G. tenuistipitata at either dose increased significantly its THC, phenoloxidase activity, and respiratory burst after 2 days. L. vannamei received hot-water extract of G. tenuistipitata at 6 microg g-1 increased its phagocytic activity and clearance efficiency to V. alginolyticus after 1 day. In another experiment, L. vannamei which had been injected with hot-water extract of G. tenuistipitata were challenged with V. alginolyticus at 2x10(6) colony-forming units (cfu) shrimp-1 and then placed in seawater of 34 per thousand. The survival of shrimp that received hot-water extract of G. tenuistipitata at 6 microg g-1 was significantly higher than that of shrimp that received saline and the control shrimp after 3 days, and at the termination of the experiment (6 days after the challenge). It is therefore concluded that L. vannamei receiving the hot-water extract of G. tenuistipitata at 6 microg g-1 or less increased its immune ability and resistance to V. alginolyticus infection.