Background: Egg yolk is the main cryoprotectant agent in semen freezing EXTENDERs which is used in order to protect spermatozoa against cold shock. However, elimination of animal bioproducts from the cryopreservation protocol is becoming mandatory. Therefore, the aim of this study is to compare a previously studied, homemade soya bean lecithin based EXTENDER with a commercially available EXTENDER for ram sperm cryopreservation. Materials and Methods: Samples from three rams were pooled and split into two equal aliquots and diluted (1:20) with i%lecithin - 7%glycerol (L1G7) and Bioxcell®. The effects of L1G7 and Bioxcell® on sperm parameters and the in vitro fertilization ability of frozen-thawed ram spermatozoa were assessed. Results: The results of this study revealed no difference between the two EXTENDERs in terms of motility, viability, and capacitation status. The results of in vitro fertilization in terms of rate of blastocyst formation were similar for both EXTENDERs, but significantly lower than that of freshly processed ram sperm. Conclusion: We conclude that both EXTENDERs are suitable for ram sperm cryopreservation.

The effects of chain EXTENDER length on the gas permeability of polyether-based polyurethanes were investigated. Synthesized polyurethanes were based on 1000 and 2000 molecular weight polytetramethylene-glycol (PTMG) with toluene diisocyanate (TDI). Ethylene glycol, 1,4-butane diol (BDO), 1,6-hexane diol (HDO) and 1,10-decane diol (DDO) chain EXTENDERs were used to complete the conversion of prepolymers to the final polyurethanes. Membranes made from polyurethane were used to study the permeability and diffusivity of nitrogen, oxygen, methane, and carbon dioxide.Lag time method was used to determine the diffusivity of gases in polyurethanes. This study indicated that glass transition temperature of the polymers decrease by chain EXTENDER's length. The increase in chain EXTENDER's length makes the phase separation more probable. DSC and FTIR studies also indicate the extent of the phase separation in polyurethanes. Permeability and diffusivity of gases increase with the increasing length of the chain EXTENDERs. Selectivity of CO2/N2 changed by chain EXTENDER length, while selectivity of CO2/CH4 and O2/N2 did not show any remarkable changes. This study shows that solubilization is the dominant mechanism in gas permeation process in polyurethane membranes.

In this study, an aqueous polyurethane dispersion based on polyester was synthesized. Fourier Transform Infrared Spectroscopy was used to monitor the end point of the polymerization. In addition, the effects of two different chain EXTENDERs were studied on the average molecular weight advancement by using gel permeation chromatography. Also, the modification of average particle size, thermal behavior of the basic resin and mechanical properties of the produced paint film were investigated by use of particle size analyzer, differential scanning calorimetry, hardness, flexibility and wet scrub tests, respectively. The results clearly explained that in constant molar ratio of NCO/OH, Using of 1,4 Butanediol as chain EXTENDER in comparison to Hexamethylenediamine, followed by decreasing in particle size, increasing in hardness and wet scrub that improved the mechanical properties of the final paint film.

Introduction: Cryopreservation of the sperm causes irreversible damage to the sperm cell. The main reason of abnormal spermatozoa during storage at low temperatures are the occurrence of lipid peroxidation (LPO), production of reactive oxygen species and antioxidants imbalances (Tuncer et al. 2010). Also, factors such as the formation of ice crystals, production of reactive oxygen species, temperature changes, lipid peroxidation, changes in membrane composition, chemical toxicity due to cryoprotectants and osmotic stress, reduce the quality of sperm after thawing (Barbas and Mascarenhas 2009). The addition of antioxidants to the diluent of bird sperm during the freezing process reduces damage to sperm and maintains motility and viability rate of sperms after its thawing, which might affect the development of artificial insemination in birds. Cysteine is a sulfurcontaining amino acid with antioxidant properties that can easily penetrate the cell membrane and increases the biosynthesis of intracellular glutathione and eliminates the free oxygen radicals (Kaeoket et al. 2010, Sariozkan et al. 2009). In recent years, researchers found that the use of cysteine as an antioxidant in the freezing of various mammalian sperm (Bucak et al. 2009; Tuncer et al. 2010) improve the mobility and the viability of frozen-thawed sperm. Materials and methods: In this study, after two weeks of adaptation period, semen was collected from eight mature roosters (Ross 308). Initial semen assessments such as volume, progressive motility, concentration, viability, and percentage of abnormal sperm were conducted in the laboratory. Next, the samples with standard quality were split into four equal aliquots and diluted (1: 30; v/v) with basic EXTENDER supplemented by different concentrations of cysteine (2. 5, 5 and 7. 5 Mm) at 37 ˚ C. In this experiment, freezing procedure was conducted in two steps. So that the 3ml of EXTENDER containing different concentrations of cysteine and semen samples, were cooled slowly at 5◦ C for 2 h to reach thermal equilibrium. Then, 1 ml of the semen EXTENDER (precooled to 5◦ C) was added to the semen (EXTENDER plus semen) to provide a final concentration of 100 × 10 6 sperm/ml and 8% glycerol at a temperature of 5℃ . Immediately after 1 h the sample was loaded into 0. 25 mL straws (IMV, L’ Aigle, France). Then, the straws were frozen in liquid nitrogen vapor, 4 cm above the liquid nitrogen, for 7 min, and plunged into liquid nitrogen for storage. After storing, the samples were evaluated twice with an interval of 15 days and frozen straws were thawed individually at 37℃ for 30 min in a water bath and then evaluated individually. Results and discussion: The quality of sperms in the present work was evaluated after keeping them for 15 and 30 days in liquid nitrogen. The results of this study showed that the sample diluted with 2. 5 mM of cysteine indicate the highest viability performance in keeping for 15 days in the liquid nitrogen compared to the control group and samples with other dosages of this amino acid (P<0/05). The viability of the sperms diluted for 30 days is considerably lower than that of those diluted during 15 days. The integrity of the membrane of sperms diluted with 5 mM of cysteine stored in liquid nitrogen for 15 days indicate the best performance compared to the samples with other dosages of amino acid and the control group (Table 3). Based on the Table 3, the minimum abnormality of sperms was seen in the group treated with 7. 5 mM of cysteine for 15 days (18. 3%) while the maximum sperm abnormality was for the sperm in control group of day 30 (30. 6%). Moreover, results of table 4 indicated that the samples with 2. 5 mM of cysteine had the best performance in terms of total and progressive motilities among other treatments and control group (P<0/05). It has been reported that sperm storage in the presence of cysteine improves sperm motility after freezing. In this experiment, cysteine increased the viability and motility of sperm compared to the control group, which were consistent with the results of previous studies on boar (Kaeoket et al. 2010), ram (Coyan et al. 2011), dog (Michael et al. 2010) Cow (Topraggaleh et al. 2014) and Goat (Memon et al. 2012). Moreover, the results of this study was agree with Partyka and et al. 2013 that proposed the cysteine (5 mM) improves the integrity of the rooster sperm membrane. Bucak et al. (2009) reported that the addition of cysteine (5 mM) and terhalose (50 mM) increased the amount of live and motile ram sperm after freezing-thawing process. According to the results of Ahmadian et al. (2014), the low level of cysteine in the thrice-based diluent provides the best response in the process of freezing-thawing of ram sperm, which is consistent with the results of our research. Conclusion: it was concluded that the cysteine improves semen quality and facilitates freezing rooster sperm for longer periods.

A novel type of polyurethane elastomer (PUE) containing nanocomposites of sodium alginate thiacalix[4]arene macrocycles including sodium alginate-thiacalix[4]arene and sodium alginate-tetra-sulfonated thaiacalix[4]arene (SA-TSTCA) was prepared. The key role of these nanocomposites merged into polyurethane elastomers is to function as chain EXTENDERs. To provide profound insight into the structural, thermal, mechanical, morphological and hydrophilic properties of the samples, several techniques were employed, namely Fourier transform infrared spectroscopy, thermal gravimetric analysis, scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). Also the results were compared with the results of polyurethane elastomer based on glycerol (Gly) as chain EXTENDER. The results showed that the samples extended with nanocomposites as chain EXTENDER have better thermal and mechanical properties and between them the PUE containing SA-TSTCA showed higher thermal and mechanical properties. Furthermore, these elastomers have been used as adsorbent for removal of Malachite green (MG) for investigation of the effect of sulfonated groups introduced on the chain EXTENDER. The results revealed that SA-TSTCA-based polyurethane elastomer nanocomposite could well adsorb Malachite green from aqueous media by a batch adsorption method. The pseudo-first-order and pseudo-second-order kinetic models were employed to provide an in-depth study of the adsorption capacity of MG, suggesting that its adsorption onto PUE/SA-TSTCA elastomer was in accordance with pseudo-second-order kinetic process. A possible mechanism of adsorption was suggested where π, –, π,stacking interactions, H-bonding interaction and electrostatic attraction controlled the MG adsorption.

This study was conducted to investigate the effect of Chrysin inclusion to semen EXTENDER on rooster sperm quality during in vitro storage. Semen samples were collected from five 44-week-old male broiler breeders (ROS 308). After primary evaluation (motility >60%), semen samples were pooled and divided into five equal part and each part was diluted with one of the following EXTENDERs: 1) control negative EXTENDER (without any additive), 2) control positive EXTENDER (with 4% DMSO), 3) EXTENDER containing 25 μ g of Chrysin (Chrysin-25), 4) EXTENDER containing 50 μ g of Chrysin (Chrysin-50) and 5) EXTENDER containing 75 μ g of Chrysin (Chrysin-75). Semen quality parameters including total and forward motility, plasma membrane integrity and functionality were assessed in 0, 6, 12 and 24 hours after preservation at 4 ° C. Based on obtained results, different levels of Chrysin failed to alter total and forward motility, plasma membrane integrity and functionality of spermatozoa during preservation period ° at 4 C (p≥ 0. 05). Also, the effect of time in all parameters and the effect of time and treatment interaction in sperm plasma membrane functionality were significant. Therefore, Chrysin inclusion failed to ameliorate the negative time-dependent detrimental effects on rooster sperm quality. However, further research is needed to confirm obtained results.

This research work was conducted to investigate the effect of using honeybee royal jelly as a protein source in tris EXTENDER on survival and motility characteristics of ram spermatozoa. Three Dallagh rams semen samples were pooled and subjected to six treatments, tris EXTENDER plus 0, 1, 2, 3, 4 and 5 percent of royal jelly, in a randomized complete block design with sub-samples in an experimental unit. Results of experiment showed that effect of royal jelly treatment improved survival of ram spermatozoa significantly (P<0.01). At post freezing stage, percentages of live and motile spermatozoa were improved with an increase of royal jelly in tris EXTENDER from 0 to 4% (34 and 31.32 to 37.32 and 34.41). Effect of tris EXTENDER with four percentage of royal jelly and tris EXTENDER with five percentage of royal jelly on live and motility of spermatozoa (37.45 and 34.56) was not significant (P<0.01). Therefore, the addition of four percent of royal jelly in tris EXTENDER is recommended for dilution and freezing ram semen.