High fat diet-induced obesity prolongs critical stages of the spermatogenic cycle in a Ldlr−/−.Leiden mouse model

Obesity can disturb spermatogenesis and subsequently affect male fertility and reproduction. In our study, we aim to elucidate at which cellular level of adult spermatogenesis the detrimental effects of obesity manifest. We induced high fat diet (HFD) obesity in low-density lipoprotein receptor knock-out Leiden (Ldlr−/−.Leiden) mice, and studied the morphological structure of the testes and histologically examined the proportion of Sertoli cells, spermatocytes and spermatids in the seminiferous tubules. We examined sperm DNA damage and chromatin condensation and measured plasma levels of leptin, testosterone, cholesterol and triglycerides. HFD-induced obesity caused high plasma leptin and abnormal testosterone levels and induced an aberrant intra-tubular organisation (ITO) which is associated with an altered spermatids/spermatocytes ratio (2:1 instead of 3:1). Mice fed a HFD had a higher level of tubules in stages VII + VIII in the spermatogenic cycle. The stages VII + VII indicate crucial processes in spermatogenic development like initiation of meiosis, initiation of spermatid elongation, and release of fully matured spermatids. In conclusion, HFD-induced obese Ldlr−/−.Leiden mice develop an aberrant ITO and alterations in the spermatogenic cycle in crucial stages (stages VII and VII). Thereby, our findings stress the importance of lifestyle guidelines in infertility treatments.

Compression and morphological properties of a bio-based polyurethane foam with aluminum hydroxide

Compression and morphological evaluation of a new bio-based polyurethane foam (PUF) with aluminum hydroxide (ATH) added as flame retardant were carried out. The PUF was obtained from a blend of vegetable oils. Compression behavior of the polyurethane with different mass fractions of flame retardant (ATH) was investigated according to ASTM D1621–16. The ATH addition highly increased the compression yield strength of the specimens, going from 0.85 MPa (no ATH) to 2.34 MPa ( + 50%wt ATH). The compression yield strain did not show a noteworthy difference up to 40% ATH, presenting a significant decrement in the PUF + 50%ATH. The compression elasticity modulus increased from 15.40 MPa (no ATH) up to 139.77 MPa ( + 50%wt ATH). SEM images were used in order to evaluate the morphological structure of the foam. Regarding the cell sizes, there was no pattern observed, therefore, the cell sizes were adopted as random. The shapes of the cells were detected as elliptical in two different directions in the same cross-sectional area. The digital image correlation (DIC) technique showed higher strain values where the transverse ellipsoid-shaped cells were located, therefore, the load-oriented ellipsoids presented higher stiffness. Thus, the results for PUF with addition of ATH show that the bio-based material presented an important improvement in the compression properties, which allows this material to become more useful for different applications, such as furniture, building and automobile industries, as well as sandwich structures.

Preparation and Thickness Optimization of Graphenic-Based Carbon Material as a Microwave Absorber

The purpose of this study is to optimize the thickness of a layered graphenic-based carbon compound, which is a non-magnetic material derived from biomass (old coconut shell). After the sample was exfoliated using HCl solution, the morphological structure showed that the material used in this study is a reduced graphene oxide (rGO), similar to carbon but with a thickness of less than 10 nm and lateral size in submicron (100 nm). The sample with a 2 mm thickness was then characterized using a vector network analyzer (VNA) to measure its reflection loss (RL). The measurement result is evaluated by converting the S-parameter values (S11 and S21) from the VNA using the Nicolsson Ross Weir (NRW) method to obtain input variables such as relative complex permeability and relative complex permittivity. Following this, the single-layer thickness of the sample was optimized using a genetic algorithm (GA), which can predict the appropriate thickness so that the optimum RL can be obtained. The optimum thickness of the sample was found to be 3.48 mm, which resulted in a much higher RL. The RL was re-measured for verification using a sample with the corresponding optimized thickness, revealing that this optimization is feasibly operational for a radar absorbing material (RAM) design. HIGHLIGHTS Carbon compounds containing graphenic phase derived from coconut shell are functional materials having various unique properties such as superior electrical conductivity, large surface area, and excellent structural flexibility, and microwave absorbtion The single-layer microwave absorber employing carbon compounds has been prepared The layer thickness optimized using a genetic algorithm (GA) can estimate the appropriate design with the maximum reflection loss (RL)

People in aviation – a linguists’ insight into history

History can be studied from a number of angles and on the basis of a variety of sources. Researchers interested in the history of aviation typically focus on the development of subsequent types of flying machines. This study relates to the history of aviation, but, due to its linguistic bias it concentrates on the semantic field <people in aviation>. The structure of this field is analysed on the basis of a collection of nouns that form the relating lexical fields. In detail the study is aimed to cast some light on the history of modern aviation, i.e. aviation that started with the 1903 flight made by the Wright Brothers in an engine-driven machine, and has been continued up to now. Importantly, in 1911, soon after the first flight took place, the first dictionary of aviation was published. This specialized dictionary served as an inspiration for an attempt to draw a linguistic picture of the discipline at the beginning of the 20th century, and later to contrast it with a linguistic picture of the discipline as emerging from modern specialized dictionaries of aviation one century later. Additionally, the analysis of particular nouns, including the study of their morphological structure and semantics leads to some interesting observations relating to the history of modern aviation.

Confocal Microscopy of Filtering Blebs after Trabeculectomy

Introduction: Filtration surgery is the most effective method of lowering intraocular pressure (IOP) in patients with insufficient medical control. It consists in facilitating the drainage of the intraocular fluid (IOF) from the anterior chamber to the subconjunctival space and subsequent lowering of IOP. The formation of filtration blebs (FB) and the processes of scarring occurring in the conjunctiva are of particular importance in glaucoma surgery. In many cases, the appearance of FB does not match the IOP values, and what causes the failure after trabeculectomy often remains unclear. Often, over time, there is a change in the structure of the FB, as fibrous tissue grows, which prevents the IOF drainage. Laser scanning in vivo confocal microscopy is a non-invasive study allowing the production of layered images at the microstructural level with high resolution of both the cornea and other structures of the anterior ocular surface. Aim: To evaluate the morphological structure and function of filtering blebs after trabeculectomy using in vivo confocal microscopy taking into account the type of implant and when the surgery was performed. Materials and methods: The study included 33 patients, 46 eyes with glaucoma. Twenty-six of the eyes had primary open-angle glaucoma (POAG), 18 eyes had pseudoexfoliative glaucoma and 2 eyes had juvenile glaucoma. All patients underwent trabeculectomy with fornix-based flap, and three of the eyes underwent retrabeculectomy. Mitomicyn C (MMC) was administered intraoperatively to all patients. The study of the filtering bleb was performed by in vivo confocal microscopy (CFM) (Heidelberg Retina Tomograph II (HRT II) /Rostock Cornea Module/ (Heidelberg Engineering GmbH, Heidelberg, Germany), the period from trabeculectomy and examination being from 1 year to 22 years. An Express implant was placed in 14 eyes, Ologen implant in 7 eyes, and 25 eyes had no implant placed. In the analysis of the morphological structure of the filtering blebs, three indicators were evaluated: the type of epithelium, the type of stroma, and blood vessels. Results: Statistical significance was established with regard to the function and morphological structure of the filtering bleb (p=0.009). Blebs with fine collagen mesh and dense collagen mesh demonstrate good function. In the case of blebs with insufficient function, those with a dense collagen network and hyper-reflective tissue predominated and there were no blebs with a fine collagen network, and in non-functioning blebs most common were those with a pronounced collagen network and hyper-reflective tissue. With regard to vascularization, we found that the functioning blebs in the shortest postoperative period were dominated by those with one blood vessel (stage 1) and there was no stage 3, with weak tortuosity, while in non-functioning blebs in the late postoperative period, there was moderate to severe vascularization and tortuosity (p=0.037), (p=0.043), (p=0.047), (p=0.021). The type of implant affects the tortuosity of the blood vessels of the filtering bleb (p=0.026). The blebs with Express implants show a slight tortuosity, followed by the blebs with Ologen implants. The highest percentage of highly kinked blood vessels occurred in blebs without an implant. Conclusions: In vivo confocal microscopy is an innovative method which allows visualization of the internal structure of the filtering blebs at a cellular level, giving us a new insight into the ongoing healing processes, premising the function of the filtering blebs after glaucoma surgery.

Ways to improve the diagnostics and detection of cervical cancer development and recurrence risk

th and the third most common female cancer worldwide. The purpose of the study was to determine risk factors and time to progression and recurrence in patients with cervical cancer after complex treatment (neoadjuvant chemotherapy + radical hysterectomy + combined radiation therapy). Methods: This retrospective study involved female patients with stage IB-IIA cervical cancer registered at Shymkent city oncological dispensary in 2011- 2021 (n=883). All patients underwent (n=883) radical hysterectomy with pelvic lymph node dissection. The patients were selected who underwent radiation therapy of the lower pelvis at a dose of ≥40 g. The age-, stage-, and tumor morphological structure-dependent survival factors and recurrence risk were analyzed during the research decade. Results: Direct correlation of the disease stage and the recurrence period was established. The progression was most often 5 to 6 months after treatment. 68.7% of progression and 63.1% of recurrences occurred in the first year and a half after the end of treatment, so this period is considered the most “dangerous” regarding the recurrence risk. 5.3% of patients had a recurrence 19 to 24 months after treatment, 31.5% – after more than two years. Conclusions: In this research, cervical cancer progressed in 74 (10.6%) out of 883 women and recurred in 19 (3.0%). The recurrence was most frequent in women aged 45-50 years (28.4%) and 50-60 years (26.3%).

Scanning electron microscopy of cuticular sensory structures on the legs of Micronecta haliploides (Horvath, 1904) and Hydrometra greeni (Kirkaldy, 1898) (Hemiptera: Heteroptera)

Structures on the legs of two hemipteran bugs, Micronecta haliploides (Horvath, 1904) and Hydrometra greeni (Kirkaldy, 1898), belonging to family Micronectidae and Hydrometridae of two infra orders Nepomorpha and Gerromorpha, respectively were investigated using scanning electron microscopy. Both species have a distinctive leg structure bearing specialised cuticular sensory structures. In the study, the sensilla were classified into five basic types: sensilla trichoidea, sensilla basiconidea, sensilla placoidea, porous circular sensilla and sensilla bell mouthed. These sensilla were further differentiated on the basis of shape, size, number, flexibility and type of socket attached. A total of 26 types of sensilla in the legs of these two species were observed. M. haliploides showed 18 types of sensory structures and H. greeni 8 types. A specific morphological structure of the porous circular sensilla was observed and found to be unique.

Assessment of prognostic factors in extracranial germ cell tumors in children

Germ cell neoplasms in the group of benign and malignant tumors heterogeneous in morphological structure, clinical features and prognosis. A special characteristic of germ cell tumors is their high sensitivity to platinum-containing chemotherapy, which allows cure of up to 80–90% patients. However 20–25% of patients with a common type have overall survival rate of less than 50%. The aim of the study is to assess the survival rate of children with extracranial germ cell tumors and to identify adverse risk factors. Methods. The study includes 116 children with extracranial germ cell tumors treated from 2013 to September 2009. Treatment consisted of tumor resection and platinum based on platinum chemotherapy. Survival rate was assessed by the Kaplan-Mayer method. Prognostic factors are determined according to IGCCCG, MaGIC, MAKEI, RODO. Results. Overall and event free survival rates were 79±5% and 76±4%, respectively. The worst overall survival had patients with extragonadal tumors, advanced stages of a disease, high initial level of AFP (≥10 000 ng/ml), non-seminoma version of state treasury bills and extra pulmonary metastases. Conclusion. Survival rate in children with extracranial germ cell tumors depends on the prognostic factors. Statistically significant predictors of the poor prognosis were extragonadal localization of a tumor and the AFP level ≥10 000 ng/ml.

Influence of the Process of Synthesis of Zeolites from Volcanic Ash in Its Synergistic Action as a Flame-Retardant for Polypropylene Composites

In this research, the influence of natural zeolites obtained from the volcanic ash of the Ubinas volcano has been studied as synergistic agents in a flame-retardant system (composed of ammonium polyphosphate, pentaerythritol, and polypropylene). Four zeolites were synthesized from volcanic ash, including those that had been calcined and those that had not. These were then placed in an alkaline solution at three synthesis temperatures. Zeolites were characterized through X-ray diffraction, specific surface area by nitrogen adsorption analysis (Brunauer–Emmett–Teller) and scanning electron microscopy. Polypropylene matrix composites were prepared with ammonium polyphosphate, pentaerythritol and zeolites at 1, 5 and 9%. Its thermal stability and fire resistance were evaluated by thermogravimetric analysis, limiting oxygen index, vertical burning test and cone calorimeter and its morphological structure by scanning electron microscopy. It was determined that the synthesis temperature and the use of calcined and without calcined volcanic ash have an influence on the characteristics of the zeolites and on its synergistic action.

Features of regional blood flow after endoscopic myomectomy

The state of regional blood flow in 65 patients before and after endoscopic myomectomy was studied using modem methods such as Doppler examination and color Doppler sonography. It was determined that blood flow velocity indeces obtained during the Doppler examination of myoma vessels and uterine arteries allow to estimate the morphological structure of myomas uninvasively and can be used to define the indications for conservative endoscopic surgical procedures in patients with myoma uteri. Doppler monitoring of regional blood flow during postoperative period makes it possible to evaluate the effectiveness of surgical treatment previously performed.