An Inverse Method of Designing the Cooling Passages of Turbine Blades Based on the Heat Adjoint Equation

A method of solution of the inverse problem in heat conduction is presented. The method, based on an adjoint optimization procedure, is applied to the design of the pattern of cooling passages inside turbine blades. For blade coating technologies, the general case of a non-homogeneous solid material is considered. The numerical solution of both the temperature field and of the adjoint problem is based on a finite element method. The new formulation of the adjoint thermal problem is deduced for three different parametric representation of the internal cooling passages. This allows the designer to select the most adequate blade parametrization, going from blades with circular coolant passages to modern multi-holed hollow blades. The mathematical method, the adjoint problem solution and the enforcement of geometric constraints are explained and the procedure is validated against theoretical, experimental data and numerical solution available in open literature

INVERSE DESIGN OF INTERNALLY COOLED TURBINE BLADES BASED ON THE HEAT ADJOINT EQUATION

A method of solution of the inverse problem in heat conduction is presented. The method, based on an adjoint optimization procedure, is applied to the design of the pattern of circular cooling passages inside coated turbine blades. The general case of a non-homogeneous solid material is considered. The numerical solution of both the temperature field and of the adjoint problem is based on a finite element method. The mathematical method is explained and the procedure is validated against theoretical and experimental data available in open literature

Implantation of autologous muscle-derived stem cells in treatment of fecal incontinence : results of an experimental pilot study

Background The aim of this study is to present results of the implantation of autologous myoblasts into the external anal sphincter (EAS) in ten patients with fecal incontinence. Methods After anatomical and functional assessment of the patients’ EAS, a vastus lateralis muscle open biopsy was performed. Stem cells were extracted from the biopsy specimens and cultured in vitro. Cell suspensions were then administered to the EAS. Patients were scheduled for follow-up visits in 6-week intervals. Total follow-up was 12 months. Results All biopsy and cell implantation procedures were performed without complications. Nine of the patients completed a full 12-month follow-up. There was subjective improvement in six patients (66.7 %). In manometric examinations 18 weeks after implantation, squeeze anal pressures and high-pressure zone length increased in all patients, with particularly significant sphincter function recovery in five patients (55.6 %). Electromyographic (EMG) examination showed an increase in signal amplitude in all patients, detecting elevated numbers of propagating action potentials. Twelve months after implantation two patients experienced deterioration of continence, which was also reflected in the deterioration of manometric and EMG parameters. The remaining four patients (44.4 %) still described their continence as better than before implantation and retained satisfactory functional examination parameters. Conclusions Implantation of autologous myoblasts gives good short-term results not only in a subjective assessment, but also in objective functional tests. It seems that this promising technology can improve the quality of life of patients with fecal incontinence, but further study is required to achieve better and more persistent results

Complex cytogenetic and molecular-genetic analysis of males with spermatogenesis failure

The chromosomal anomalies, microdeletions of AZF region of Y-chromosome and CFTR gene mutations have been studied among 80 infertile men with idiopathic spermatogenetic failure: 36 (45 %) patients with aspermia, 19 (24 %) patients with azoospermia and 25 (31 %) patients with severe oligoasthenoteratozoospermia. In total 30 % males with spermatogenetic failure genetic factor of infertility was observed. Karyotype anomalies were observed in 17.5 % of infertile men, within 16.2 % numerical and structural gonosomal anomalies and in 1.3 % – Robertsonian translocation were revealed. In 11 % males with spermatogenetic failure, Y-chromosome AZF region microdeletions were detected. The frequency of CFTR major mutation F508del among infertile men was 6.25 %. 5T allele of polymorphic locus IVS8polyT was detected in 7.5 % of examined men. The results obtained indicate the high complexity of cytogenetic and moleculargenetic studies of male infertility.Изучали аномалии хромосом, микроделеции AZF региона Y-хромосомы и мутации гена ТРБМ у 80 мужчин с идиопатическими нарушениями сперматогенеза, а именно: у 36 (45 %) пациентов с аспермией, 19 (24 %) пациентов с азооспермией и 25 (31 %) пациентов с олигоастенотератозооспермией IV степени. В общем у 30 % мужчин с нарушениями сперматогенеза установлены генетические факторы бесплодия. Нарушения кариотипа наблюдали у 17.5 % бесплодных мужчин, среди них у 16.2 % – количественные и структурные аномалии хромосом и у 1.3 % – робертсоновскую транслокацию. У 11 % мужчин с нарушениями сперматогенеза выявили микроделеции AZF региона Y хромосомы. Частота мажорной мутации F508del гена ТРБМ среди бесплодных мужчин составила 6.25 %. 5T аллель полиморфного локуса IVS8polyT выявили у 7.5 % обследованных мужчин. Полученные результаты свидетельствуют о высокой информативности комплексного цитогенетического и молекулярно-генетического исследования при мужском бесплодии

Standards in semen examination:publishing reproducible and reliable data based on high-quality methodology

Biomedical science is rapidly developing in terms of more transparency, openness and reproducibility of scientific publications. This is even more important for all studies that are based on results from basic semen examination. Recently two concordant documents have been published: the 6th edition of the WHO Laboratory Manual for the Examination and Processing of Human Semen, and the International Standard ISO 23162:2021. With these tools, we propose that authors should be instructed to follow these laboratory methods in order to publish studies in peer-reviewed journals, preferable by using a checklist as suggested in an Appendix to this article.Peer reviewe

Standards in semen examination: publishing reproducible and reliable data based on high-quality methodology

Biomedical science is rapidly developing in terms of more transparency, openness and reproducibility of scientific publications. This is even more important for all studies that are based on results from basic semen examination. Recently two concordant documents have been published: the 6th edition of the WHO Laboratory Manual for the Examination and Processing of Human Semen, and the International Standard ISO 23162:2021. With these tools, we propose that authors should be instructed to follow these laboratory methods in order to publish studies in peer-reviewed journals, preferable by using a checklist as suggested in an Appendix to this article

Complex nature of the human antisperm antibody response in SCID mice

Human peripheral blood mononuclear (PBMs) cells were introduced into the peritoneal cavity of severely-combined immunodeficient (SCID) mice in concentrations of 2.5-4.0 x 10(7) cells per mouse. Whole mononuclear cell suspensions were used either unstimulated or following primary in vitro culture with human spermatozoa. In some experiments, immunodepletion of CD8(+) cells was carried out prior to grafting. Lymphocytes were obtained from nonsensitized (to antigen) human subjects or from individuals who were primed in vivo (vasectomized individuals in case of sperm antigens). An enzyme-linked immunosorbent assay was employed to assess total human immunoglobulin (G or M) levels as well as the specificity of the antibodies generated. We have been successful by generating primary and secondary immune responses with 'naïve' human lymphocytes, challenged with chlamydia or ovalbumin but without adjuvant or CD8(+) immunodepletion; however, we were unable to induce specific antibodies to spermatozoa under this regime in SCID male mice. We then employed female SCID mice, treated with sperm antigen extracts (glycosylated or deglycosylated) encapsulated in liposomes and human lymphocytes obtained from 'naïve' or pre-sensitized in vivo subjects. It was found that the most pronounced humoral response to sperm antigens was obtained with deglycosylated antigens and PBMs from vasectomized (in vivo pre-primed to spermatozoa) individuals. A presented SCID mice model can be helpful at understanding of antisperm antibody development and the molecular nature of generated antibodies to modified sperm antigenic entities