Treatment of cryptorchidism in pediatric surgical practice: a multicenter study

Introduction. Cryptorchidism is a common disease in pediatric urological and andrological practice since the issues of tactical approaches and its optimal treatment remain extremely relevant. Cryptorchidism makes a significant contribution to the structure of male infertility.Objective. To conduct a retrospective analysis of treatment results in children and adolescents with cryptorchidism.Materials & methods. This study summarises the treatment results of 8308 patients with cryptorchidism aged from 6 months to 17 years who underwent inpatient treatment in the Russian Federation and the Republic of Uzbekistan.Results. It was revealed that from 2015 to 2019, patients were admitted for surgical treatment evenly over the years. The ratio of right-sided / left-sided / bilateral cryptorchidism was 4.6 : 4.4 : 1 The inguinal form prevailed more than 6 times over the abdominal location. At the same time, 26.1% of the patients underwent surgery at the optimal time, and 9.8% were older than 10 years. More often, children are operated from an open inguinal access (95.0%), much less often — laparoscopically and percutaneously. Stage-by-stage treatment was carried out in 6.0% of patients.Conclusion. Thus, the approach presented in the study in the surgical treatment of cryptorchidism provided good treatment results. The number of disease relapses was 1.9% (mainly among children over 7 years old). Most surgeons are very reserved about primary orchidectomies (only 3.8% were performed)

The Management of Characteristics of the New Two-layer Rubber Matrix Seals

Rubber seals for closing devices operating in cold climates degrade quickly in aggressive environments at very low temperatures. As a result, leaks and failures occur in the closure devices. Therefore, there is a great need to develop a new model of rubber seals and develop their scientific basis. The article is devoted to increasing the sealing effect of rubber seals of machines and equipment, including closures, by introducing the anisotropy of the rubber matrix into its structure with control of the characteristics of hard closures obtained from rubber. For this purpose, new models of the gate valve design were obtained and new models of two-layer panel seals based on a modified rubber elastomer matrix are applied to these structures. For this, a test program is carried out in the form of an analytical trajectory of large, medium and small constant curves in two closed forms based on characteristic deformations to study the anisotropy of matrix deformations. It is found that the eigenvector of the deformation anisotropy of the matrix is not in the load trajectory before it collapses, it arises with a delay. This delay slows down the rate of destruction. This property of deceleration of the main eigenvector of the deformation anisotropy of the matrix is subjected to a very complex loading of the initial fields, in the latter sections it is also observed in samples No. 2, No. 3, tested along the trajectory of linear loading. This delay slows down the destruction rate. Thus, the direction of the deceleration property of the main eigenvector can be considered quite common. This leads to an increase in its resistance to wear in a highly aggressive environmen