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This paper presents the design and development of a multiple-inputmultiple-output (MIMO) compact antenna with coplanar waveguide (CPW) feed for 5G millimeter-wave applications. It can be operated in the C (4-8 GHz), Ku (12-18 GHz), K (18-26.5 GHz), and Ka (27-40 GHz) with full coverage of the millimeter wave 5G New Radio (NR) n257/n258/n261 bands.The proposed antenna is designed with planar geometry with an element size of 14 mm×19 mm, which makes it compact and achieves a wide operating bandwidth. By the arrangement of orthogonal rotation, the 4-port structure is formed to realize good polarization diversity. The result shows that the MIMO antenna has a stable radiation pattern at the low-frequency band and offers an ultra-wide bandwidth (UWB) of 5-39 GHz (154.5%), isolation of more than 19 dB, and a total footprint of 40 mm×40 mm. ECC9.99, CCL

Background: Left paraduodenal hernia (PDH) is a mesenterico-parietal hernia with retroperitoneal retrocolic herniation of the small bowel into a sac formed by a peritoneal fold located near the fourth portion of the duodenum. It’s a rare cause of hydronephrosis by compressed the upper left ureter. Traditionally, PDH are treated by laparotomy.Case presentation: An 8-year-old boy’s primary purpose was the treatment of cryptorchidism. But hydronephrosis was detected and it was induced by left paraduodenal hernia. Diagnostic laparoscopic exploration confirmed the diagnosis left paraduodenal hernia secondary hydronephrosis. Cryptorchidism was the primary purpose of treatment. The patient was treated with laparoscopic surgery, fixed left paraduodenal hernia, released the ureteropelvic junction obstruction (UPJO) and treated hydronephrosis.Conclusion: Secondary surgery for treating cryptorchidism would be performed and the long-term follow up was necessary.This case suggests us a rare cause of hydronephrosis in children. Every why has a wherefore. We must pay much attention to any unusual details in our medical work even though these details aren’t related to our primary objects.