In vitro effect of zearalenone on sperm parameters, oocyte maturation and embryonic development in buffalo.

The negative impact of zearalenone (ZEN; potent estrogenic mycotoxin) exposure on buffalo embryo production has not yet been determined. In the current study, buffalo sperm and oocytes were exposed to ZEN at different concentrations during maturation. Sperms (with and without ZEN exposure) were incubated for 2 h and evaluated for motility, viability, acrosome integrity, normality, and ultrastructure. Matured oocytes exposed to ZEN were stained to determine their nuclear maturation. Further, their developmental ability was evaluated after in vitro fertilization. Our results showed the toxic effects of ZEN at high concentrations (2000 ng/mL) on different buffalo sperm parameters. The number of acrosome-intact sperm was reduced at 0 h after exposure to a concentration of ≥ 100 ng/mL. Furthermore, the maturation rate of buffalo oocytes (telophase I + metaphase II) was significantly decreased in ZEN-treated oocytes with a higher degeneration rate. Oocytes matured in 1000 ng/mL ZEN and subsequently exhibited considerable reduction in cleavage rate and blastocyst formation compared with control oocytes (2.6% vs. 13.1%). Moreover, the morula rate was decreased (p < 0.001) in ZEN-treated oocytes at concentrations of ≥ 10 ng/mL. Overall, the adverse effects of in vitro ZEN exposure on buffalo sperm parameters and oocyte meiotic progression with a notable reduction in cleavage, morula, and blastocyst rates were defined by these results. Altogether, buffaloes should be considered sensitive to ZEN exposure with respect to their reproductive function.

Exogenous gonadotropin-releasing hormone counteracts the adverse effect of scrotal insulation on testicular functions in bucks.

This study determined the effects of scrotal insulation on testicular functions in bucks and evaluated the impact of exogenous gonadotropin-releasing hormone (GnRH) administration before scrotal insulation on sperm production and testicular vascular dynamics. Twelve bucks were randomly divided into three groups: scrotal-insulated animals without GnRH treatment (INS), scrotal-insulated animals treated previously with GnRH (GnRH + INS), and animals without insulation as controls (CON). Doppler ultrasonography was used to evaluate testicular vascular changes, and semen samples were collected to assess seminal parameters. Testicular samples were collected from slaughtered bucks at the end of the experiment for histological investigations and immunohistochemical analysis for caspase 3 (apoptotic marker), and a vascular endothelial growth factor (VEGF; hypoxic marker) evaluation. Sperm motility drastically decreased (33%) in the INS group on day 8 compared with those in the GnRH + INS and CON groups (58% and 85%, respectively). Testicular blood flow significantly decreased for 3 and 2 weeks in the INS and GnRH + INS groups, respectively. The pulsatility index (PI) reached pretreatment values at 5 and 4 weeks after insulation in the INS and GnRH + INS groups, respectively. The resistance index (RI) values increased in both insulated groups for the first 2 weeks and decreased to control values 4 weeks after insulation. However, the maximum velocity (VP) started to increase reaching pretreatment values by the 5th and 3rd weeks after insulation in the INS and GnRH + INS groups, respectively. Histological investigations showed a marked reduction in lipid inclusions in Sertoli cells in the GnRH + INS group compared with those in the INS group. The distributions of both caspase 3 and VEGF decreased in the GnRH + INS group compared with those in the INS group. This study showed that the administration of a single dose of GnRH delayed the negative effects of scrotal insulation on different seminal traits and revealed the pivotal role of GnRH in compensating testicular insulation in bucks.

Review of cooling techniques used to enhance the efficiency of photovoltaic power systems.

Photovoltaic (PV) panels are one of the most important solar energy sources used to convert the sun's radiation falling on them into electrical power directly. Many factors affect the functioning of photovoltaic panels, including external factors and internal factors. External factors such as wind speed, incident radiation rate, ambient temperature, and dust accumulation on the PV cannot be controlled. The internal factors can be controlled, such as PV surface temperature. Some of the radiation falling on the surface of the PV cell turns into electricity, while the remainder of incident radiation is absorbed inside the PV cell. This, in turn, elevates its surface temperature. Undesirably, the higher panel temperature, the lower conversion performance, and lesser reliability over the long term occur. Hence, many cooling systems have been designed and investigated, aiming to effectively avoid the excessive temperature rise and enhance their efficiency. Many cooling methods are used to cool solar cells, such as passive cooling, active cooling, cooling with phase change materials (PCMs), and cooling with PCM with other additives such as nanoparticles or porous metal. In this work, the common methods utilized for cooling PV panels are reviewed and analyzed, focusing on the last methods, and summarizing all the researches that dealt with cooling PV solar cells with PCM and porous structures.

Enhancement of the daily performance of solar still by exhaust gases under hot and cold climate conditions.

A study is presented on the enhancement of solar still (SS) performance by using chimney exhaust gases (EGs) passing through chimney channels under the still basin. The impact of the exhaust gas temperature on the SS temperature, productivity, efficiency, and freshwater yield cost is considered. The SS performance with the chimney is compared with that of conventional solar still. The study is performed under the hot and cold climate conditions of Upper Egypt. A complete transient mathematical model of the physical model including the solar still regions temperatures, yield, and heat transfer between the SS and the EGs is constructed. This model is solved by using Runge-Kutta method of fourth-order and programmed inside MATLAB software and validated using an experimental setup. The results show that the SS saline water temperature and freshwater yield rise with rising EGs temperatures. Furthermore, the impact of using EGs on the SS performance in winter is superior to that in summer, and also during the daytime is higher than that of night. Using chimney EGs at 75 °C and 125 °C enhances the daily freshwater yield of the SS by more than three times and about six times in winter, respectively, and about two and half times and more than three times in summer, respectively. Using EGs at 125 °C achieves a maximum solar still efficiency of 29.5% in winter and 49.5% in summer with an increase of 41% and 55.7%, respectively, and reduces its yield cost by 63.6% compared to conventional SS.

Assessment of double-pass pin finned solar air heater at different air mass ratios via energy, exergy, economic, and environmental (4E) approaches.

In this study, an assessment based on energy, exergy, economic, and environmental approaches on a double-pass (DP) solar air heater (SAH) having pin finned absorber at different air mass ratios up and down the absorber is investigated experimentally. Four air mass ratios are considered: (i) all the air mass flow passes up the absorber and returns to pass down the absorber (DP), (ii) 2/3 of the airflow passes up the absorber and returns to mix with the remainder of air to pass down the absorber (2/3 DP), (iii) the same as (ii) but 1/3 of the air passes up the absorber (1/3 DP), and (iv) all the air mass passes only down the absorber (single pass, SP). For all mass ratios, the performance of pin finned SAH (P_SAH) is compared with that of flat SAH (F_SAH). The results indicated that the air temperature rise and energy and exergy efficiencies of P_SAH are highly greater than those of F_SAH. The highest average thermal efficiency of F_SAH is 56.7% obtained at DP flow condition, whereas the highest value of P_SAH is 65.21% obtained at 2/3 DP with an increase of 17.6% compared with F_SAH. Also, P_SAH has higher average exergy efficiency of about 34.7% compared to F_SAH. Furthermore, P_SAH achieves energy payback time (EPBT) lower than that of F_SAH, while P_SAH has higher embodied energy. The findings indicated that F_SAH at SP airflow pattern has the maximum energy cost (0.0427 $/kWh), whereas P_SAH at 2/3 DP airflow pattern achieves the minimum energy cost (0.037 $/kWh). Finally, the proposed P_SAH system appears to be more viable from exergoeconomic and enviroeconomic approaches compared to F_SAH.

Productivity, exergy, exergoeconomic, and enviroeconomic assessment of hybrid solar distiller using direct salty water heating.

In this work, experimental work is presented on the performance of a hybrid solar distiller comprising solar still (SS) combined with parabolic trough solar collector (PTSC) using direct heating of salty water by the collector. In this technique, the salty water supplied to the SS is heated by passing it directly through the parabolic receiver without using heat transfer mediums that reduce the system efficiency. The study is carried out at different salty water depths inside the SS basin under hot climate conditions of Upper Egypt. The system performance is compared with a previous system using oil as a heat transfer medium between PTSC and still (indirect heating). The advantages of this technique are its ability to reduce initial salty water depth in the basin and avoid using the pumping system and heat exchanger compared to the direct heating. The performance of the proposed system is evaluated based on productivity, energy payback time (EPBT), exergy, enviroeconomic, and exergoeconomic methodologies. Findings illustrate that the present system rises the energy efficiency by about 12%, 27.5%, and 46% and the system exergy efficiency by about 14%, 30%, and 49% at salty water depth 15 mm, 10 mm, and 5 mm in the basin compared with the indirect heating system. Moreover, using this technique of salty water heating reduces the production cost of freshwater by about 71% compared with the direct heating system. The exergoeconomic and enviroeconomic parameters of the direct heating mechanism are more effective compared with those of the indirect heating mechanism.

Energy, exergy, environmental, and economic analysis of natural and forced cooling of solar still with porous media.

The performance of single slope solar still with an enhanced condenser at different saline water mediums in the basin is studied and assessed based on productivity, energy, exergy, economic, and enviroeconomic methodologies. Six solar still configurations are considered: conventional solar still (CSS); modified solar still (MSS) which is a still with heat sink condenser; MSS having an umbrella (MSS + U); MSS with forced-air cooling (MSS + FA); MSS with forced-water cooling (MSS + FW); and finally, MSS with forced-water cooling and contains sand in the basin (MSS + FW + SD). Experiments are conducted under hot and cold climate conditions of Sohag city, Egypt. The results indicate that the MSS + FW + SD has a maximum daily yield of 5.37 kg/m2 in summer and 2.74 kg/m2 in winter with an increase of 36% in summer and 26% in winter compared with CSS. It was found that the maximum increase of the energy and exergy efficiency compared with CSS is achieved in the case of MSS + FW + SD of 39% and 33%, respectively. Furthermore, the maximum and minimum cost of freshwater is achieved in cases of MSS + U and MSS + FW + SD, respectively. Finally, among all studied systems, MSS + FW + SD achieves the best performance based on the exergoeconomic approach.

Salmonella Typhimurium Triggered Unilateral Epididymo-Orchitis and Splenomegaly in a Holstein Bull in Assiut, Egypt: A Case Report.

This report illustrates, for the first time, a case of unilateral orchitis and epididymitis in a Holstein-Friesian bull, associated with Salmonella enterica infection (Salmonella enterica serovar Typhimurium). A one and a half-year-old Holstein-Friesian bull had arrived at the Veterinary Hospital of Assiut University suffering from anorexia accompanied with persistent fever, which did not respond to oxytetracycline and flunixin meglumine injection for 15 days. Gross examination revealed left scrotal enlargement (three times its normal size), heat sensation, and induration of the testis and epididymis, which was painful on external palpation. Microbiological and pathological examinations of the left testicle, epididymis, and spleen samples were performed. S. Typhimurium was recovered from the affected tissues and its critical virulence genes (stn, avrA and sopB) were identified. Pathological examination revealed a unilateral necrotizing intratubular pyogranulomatus orchitis and epididymitis with severe peri-orchitis. In addition, splenomegaly with a firm and large whitish nodular capsular structure associated with different stages of granulomatous reaction around the white and red pulp. To the authors' knowledge, this report is the first isolation of S. Typhimurium from the epididymis and testicles of a Holstein-Friesian bull. These results highlight the importance of including S. Typhimurium among the health disorders associated with stressful situations in bovine with orchitis and or/epididymitis. In Egypt, Salmonella spp. infection as being enzootic with high probability of dissemination should be considered one of genital health problems among cattle farms.

Ovulatory follicular fluid induces sperm phagocytosis by neutrophils, but oviductal fluid around oestrus suppresses its inflammatory effect in the buffalo oviduct in vitro.

We have recently shown that the conditioned media from bovine oviductal epithelial cell culture suppress sperm phagocytosis by neutrophils, suggesting that the oviduct around oestrus supplies the anti-inflammatory microenvironment. To investigate the immune response of neutrophils toward the sperm at ovulation in the buffalo oviduct, we examined (a) a detailed distribution of neutrophils in the oviduct in buffaloes, (b) the effect of ovulatory follicular fluid (FF) and oviductal fluid (OF) on sperm phagocytosis by neutrophils, and (c) the interaction of the ovulatory FF with OF on sperm phagocytosis by neutrophils in vitro. Buffalo oviducts were collected from healthy reproductive tracts at a local slaughterhouse. A detailed observation by histological examination and transmission electron microscopy revealed that neutrophils exist in the oviduct epithelium and lumen throughout the oestrous cycle in buffaloes. The number of neutrophils at the oestrus stage was higher in ampulla compared with those in isthmus, whereas they remained relatively constant at the dioestrus stage. Two hours of preincubation of neutrophils with FF enhanced sperm phagocytosis through the formation of neutrophil extracellular traps (NETs) together with H2 O2 production, whereas OF around oestrus (eOF) suppressed sperm phagocytosis, NETs formation, and H2 O2 production and relieved the above FF-induced inflammatory response. Our findings show that neutrophils exist in the healthy cyclic oviduct across bovine species, and the OF supplies a strong anti-inflammatory environment that could minimize the inflammatory effect of the FF that flows into the oviduct lumen after ovulation and supports the occurrence of fertilization.

Oviduct epithelium induces interferon-tau in bovine Day-4 embryos, which generates an anti-inflammatory response in immune cells.

Recent studies indicate that communication between the bovine embryo and the mother begins in the oviduct. Here, we aimed to investigate the effect of embryos on bovine oviducts for their immune responses using an in vitro model. First, zygotes were cultured with or without bovine oviduct epithelial cells (BOECs) for 4 days, when embryos had reached the 16-cell stage. At that time, we detected interferon-tau (IFNT) in embryos co-cultured with BOECs, but not in embryos cultured alone. Next, peripheral blood mononuclear cells (PBMCs) were incubated either in media from embryo alone cultures or from co-cultures of embryos with BOECs. The medium from embryo alone cultures did not modulate PBMCs gene expression; whereas the embryo-BOEC co-culture medium increased interferon-stimulated genes (ISGs: ISG15, OAS1, MX2), STAT1, PTGES and TGFB1 but suppressed IL17 expression in PBMCs. Both IFNT-treated BOEC culture medium and IFNT-supplemented fresh medium alone without BOEC, modulated PBMCs gene expressions similar to those by the embryo-BOEC co-culture medium. Further, specific antibody to IFNT neutralized the effect of embryo-BOEC co-culture medium on PBMCs gene expression. Our results indicate that BOECs stimulate embryos to produce IFNT, which then acts on immune cells to promote an anti-inflammatory response in the oviduct.

Zearalenone (ZEN) disrupts the anti-inflammatory response of bovine oviductal epithelial cells to sperm in vitro.

Dietary contamination by Zearalenone (ZEN) has a detrimental effect on bovine fertility. Recently, we showed a novel anti-inflammatory response of bovine oviductal epithelial cells (BOEC) to active sperm cells in vitro. The aim of the present study was to investigate the effect of ZEN exposure of BOEC on the immune-related cytokine expression in response to bovine sperm. At concentrations of 100 and 1000ng/mL, ZEN induced the expression of TNF and IL1B (pro-inflammatory cytokines) as well as IL8 (chemokine) in BOEC in a dose-dependent manner. Furthermore, ZEN induced PTGES expression and PGE2 secretion in BOEC. Sperm co-culture induced an anti-inflammatory response in BOEC with upregulation of TGFB, secretion of PGE2 and downregulation of TNF. Most importantly, ZEN at 1-1000ng/mL eliminated the response of BOEC to sperm. Estradiol-17ß (5ng/mL) treatment did not produce the same effects as ZEN, suggesting that the response of BOEC to ZEN is, at least in part, not mediated by estrogen receptors. Taken together, ZEN can produce inflammatory effects on BOEC by stimulating the expressions of pro-inflammatory cytokines and disrupt the normal interaction between sperm and BOEC at the level of cytokine expressions and PGE2 production. Thus, exposure of the bovine oviduct to ZEN may negatively affect sperm survival and reduce fertility.

Bovine embryo induces an anti-inflammatory response in uterine epithelial cells and immune cells in vitro: possible involvement of interferon tau as an intermediator.

Recent observations suggest that the bovine uterus starts to react to the early embryo immediately after its arrival from the oviduct. The present study aimed to investigate the effect of the early developing embryo on the immune-related gene profile in bovine uterine epithelial cells (BUECs) in vitro, and to further examine the impact of conditioned media (CM), either from embryo-BUEC co-culture or embryo culture alone, on gene expression in peripheral blood mononuclear cells (PBMCs). First, BUECs were co-cultured with morulae (n = 10) for D5-D9 (D0 = IVF), and gene expression in BUECs was analyzed. Subsequently, PBMCs were cultured in CM from embryo-BUEC co-culture or D5-D9 embryo culture, and gene expression was evaluated. In BUECs, the embryo induced interferon (IFN)-stimulated genes (ISGs: ISG15, OAS1, and MX2), a key factor for IFN-signaling (STAT1), and type-1 IFN receptors (IFNAR1 and IFNAR2), with suppression of NFkB2, NFkBIA and pro-inflammatory cytokines (TNFA and IL1B). The embryo also stimulated PTGES and PGE2 secretion in BUECs. In PBMCs, both CM from embryo-BUEC co-culture and embryo culture alone induced ISGs, STAT1 and TGFB1, while suppressing TNFA and IL17. Similarly, interferon tau (IFNT) at 100 pg/ml suppressed NFkB2, TNFA and IL1B in BUECs, and also stimulated TGFB1 and suppressed TNFA in PBMCs. Our findings suggest that the bovine embryo, in the first four days in the uterus (D5-D9), starts to induce an anti-inflammatory response in epithelial cells and in immune cells. IFNT is likely to act as one of the intermediators for induction of the anti-inflammatory response in the bovine uterus.

Unified analysis and mathematical representation of film-thickness behavior of film-substrate systems.

The ellipsometric function p of a film-substrate system is studied as the film thickness d is kept constant and the angle of incidence phi is changed. The generated constant-thickness contours (CTCs) are characterized by an introduced mathematical behavior indicator that represents a group of CTCs. The behavior of each group is developed and studied in the four planes phi-d, X, Z, and p, where X is the film-thickness exponential function and Z is a previously introduced intermediate plane. In the phi-d plane the film-thickness domain is identified and divided into a sequence of disconnected thickness subdomains (DTSs), depending on only N0 and N1, and their number depending on the range in which N0/N1 lies. The behavior of the CTCs in the successive planes X, Z, and p is then studied in each DTS, and the CTC's space is divided into disconnected subfamilies according to the behavior indicator. Equivalence classes that reduce the infinite number of subfamilies into a finite number are then introduced. The transformation from each plane to the next is studied with the origin of the Z plane mapped onto the point at infinity of the p plane, forming a singularity. A multiple-film-thickness inequality is derived to determine the unique solution of the film thickness. The type of reflection being internal or external at both ambient-film and film-substrate interfaces affects the analysis and is also considered. To conclude we introduce the design of polarization-preserving devices and a novel oscillating single-element ellipsometer to fully characterize zero film-substrate systems as examples of applying the knowledge developed here.