Efficacy of pentamidine-loaded chitosan nanoparticles as a novel drug delivery system for Leishmania tropica.

The present study compares the in vitro effects of nanoparticles loaded pentamidine drug and conventional pentamidine on Leishmania tropica. Herein, pentamidine-loaded chitosan nanoparticles (PTN-CNPs) have been synthesized through an ionic gelation method with sodium tripolyphosphate (TPP). Next, the physical characteristics of PTN-CNPs were determined through the surface texture, zeta potential, in vitro drug release, drug loading content (DLC), and encapsulation efficacy (EE) and compared its efficacy with free pentamidine (PTN) drug against promastigotes and axenic amastigotes forms of L. tropica in vitro. The PTN-CNPs displayed a spherical shape having a size of 88 nm, an almost negative surface charge (-3.09 mV), EE for PTN entrapment of 86%, and in vitro drug release of 92% after 36 h. In vitro antileishmanial activity of PTN-CNPs and free PTN was performed against Leishmania tropica KWH23 promastigote and axenic amastigote using 3-(4, 5- dimethylthiazol-2-yl)-2, 5-diphenyletetrazolium bromide (MTT) assay. It was observed that the effect of PTN-CNPs and free PTN on both forms of the parasite was dose and time dependent. Free PTN presented low efficacy even at higher dose (40 µg/ml) with 25.6 ± 1.3 and 26.5 ±1.4 mean viability rate of the promastigotes and axenic amastigotes, respectively after 72 hrs incubation. While PTN-CNPs showed strong antileishmanial effects on both forms of parasite with 16 ± 0.4 and 19 ± 0.7 mean viability rate at the same higher concentration (40 µg/ml) after 72 hrs incubation. Half maximal inhibitory concentration (IC50) values of PTN-CNPs toward promastigotes and amastigotes were obtained as 0.1375 µg/ml and 0.1910 µg/ml, respectively. In conclusion, PTN-CNPs effectively inhibited both forms of the L. tropica; however, its effect was more salient on promastigotes. This data indicates that the PTN-CNPs act as a target drug delivery system. However, further research is needed to support its efficacy in animal and human CL.

Efficacy of pentamidine-loaded chitosan nanoparticles as a novel drug delivery system for Leishmania tropica

@#The present study compares the in vitro effects of nanoparticles loaded pentamidine drug and conventional pentamidine on Leishmania tropica. Herein, pentamidine-loaded chitosan nanoparticles (PTN-CNPs) have been synthesized through an ionic gelation method with sodium tripolyphosphate (TPP). Next, the physical characteristics of PTN-CNPs were determined through the surface texture, zeta potential, in vitro drug release, drug loading content (DLC), and encapsulation efficacy (EE) and compared its efficacy with free pentamidine (PTN) drug against promastigotes and axenic amastigotes forms of L. tropica in vitro. The PTN-CNPs displayed a spherical shape having a size of 88 nm, an almost negative surface charge (-3.09 mV), EE for PTN entrapment of 86%, and in vitro drug release of 92% after 36 h. In vitro antileishmanial activity of PTN-CNPs and free PTN was performed against Leishmania tropica KWH23 promastigote and axenic amastigote using 3-(4, 5- dimethylthiazol-2-yl)-2, 5-diphenyletetrazolium bromide (MTT) assay. It was observed that the effect of PTN-CNPs and free PTN on both forms of the parasite was dose and time dependent. Free PTN presented low efficacy even at higher dose (40 µg/ml) with 25.6 ± 1.3 and 26.5 ±1.4 mean viability rate of the promastigotes and axenic amastigotes, respectively after 72 hrs incubation. While PTN-CNPs showed strong antileishmanial effects on both forms of parasite with 16 ± 0.4 and 19 ± 0.7 mean viability rate at the same higher concentration (40 µg/ml) after 72 hrs incubation. Half maximal inhibitory concentration (IC50) values of PTN-CNPs toward promastigotes and amastigotes were obtained as 0.1375 µg/ml and 0.1910 µg/ml, respectively. In conclusion, PTN-CNPs effectively inhibited both forms of the L. tropica; however, its effect was more salient on promastigotes. This data indicates that the PTN-CNPs act as a target drug delivery system. However, further research is needed to support its efficacy in animal and human CL.

Cellulose acetate based Complexation-NF membranes for the removal of Pb(II) from waste water.

This study investigates the removal of Pb(II) using polymer matrix membranes, cellulose acetate/vinyl triethoxysilane modified graphene oxide and gum Arabic (GuA) membranes. These complexation-NF membranes were successfully synthesized via dissolution casting method for better transport phenomenon. The varied concentrations of GuA were induced in the polymer matrix membrane. The prepared membranes M-GuA2-M-GuA10 were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, atomic force microscope and bio-fouling studies. Thermal stability of the membranes was determined by thermogravimetric analysis under nitrogen atmosphere. Dead end nanofiltration was carried out to study the perm- selectivity of all the membranes under varied pressure and concentration of Pb(NO3)2. The complexation-NF membrane performances were significantly improved after the addition of GuA in the polymer matrix membrane system. M-GuA8 membrane showed optimum result of permeation flux 8.6 l m-2 h-1. Rejection of Pb(II) ions was observed to be around 97.6% at pH 9 for all the membranes due to electrostatic interaction between CA and Gum Arabic. Moreover, with the passage of time, the rate of adsorption was also increased up to 15.7 mg g-1 until steady state was attained. Gum Arabic modified CA membranes can open up new possibilities in enhancing the permeability, hydrophilicity and anti-fouling properties.

Evaluating the nutritive profile of three insect meals and their effects to replace soya bean in broiler diet.

This study was conducted to evaluate the comparative effect of maggot meal, silkworm meal and mealworm as dietary protein source on the production performance and some aspects of meat quality in broilers. In this regard, maggot meal was reared on chicken offal and poultry waste. Silkworm meal was obtained from silk industry, while mealworm was developed through beetles rearing. A total of 120-day-old broiler chicks were randomly divided into four groups where soya bean meal (M0) was replaced with maggot meal (M1), silkworm meal (M2) and mealworm (M3) respectively. Each group was further divided into three replicates. The study was carried out for a period of 5 weeks. Diets containing mealworm significantly reduced overall feed consumption and resulted into higher weight gain (p < .05). Lowest feed conversion ratio (FCR) was recorded for birds fed with mealworm diet (p < .05). Tenderness and juiciness of meat were higher (p < .05) in M3 compared to the control and other treatments. Mortality did not vary between the control and the treated groups. Therefore, it is concluded that insect meal is rich in essential nutrients and could be successfully used in broiler ration without compromising acceptability. In the light of this study, mealworm is the best choice in broiler ration, in comparison with maggot and silkworm.

Effect of lactic acid bacteria-treated King grass silage on the performance traits and serum metabolites in New Zealand white rabbits (Oryctolagus cuniculus).

This study examined the effects of Lactobacillus plantarum and Pediococcus acidilactici-treated silage of King grass (Pennisetum purpureophoides) on the productive traits and blood biochemistry of New Zealand white (NZW) rabbits. King grass was ensiled without or with L. plantarum (T1), P. acidilactici (T2) and P. acidilactici + L. plantarum (T3). A total of 72 male NZW rabbits (6 weeks) of similar weight and appearance were housed in groups in metallic cages in a completely randomized design. The performance traits, daily feed intake, body weight gain and feed convention ratio were not affected by the silage treatment. Triglyceride and alanine aminotransferase (ALT) concentration was increased (p < .05) in T2 (0.92 mmol/L) compared to the other treatments. The superoxide dismutase (SOD), phosphorous (P) and magnesium (Mg) increased (p < .05) in T1 (658.01 nmol/ml, 5.1 mg/kg and 2.43 mg/kg, respectively) compared to the control and other experimental groups. Cu and Mn decreased (p < .05), while Zn increased (p < .05) in the treated groups compared to the control. The CP decreased (p < .05) in the treatment groups compared to the control. Neutral detergent fibre (NDF) increased (p < .05) in T2 (54.40%) compared to the other treatments. The inoculation of lactic acid bacteria-treated King grass silage supplementation positively affected rabbit performance and improved blood cholesterol profile, antioxidant status and improve nutrients digestibility.

Comparative effects of direct-fed microbials alone or with a trace minerals supplements on the productive performance, blood metabolites, and antioxidant status in grazing Awassi lambs.

Twenty Awassi lambs were used to find the effects of direct-fed microbials (DFM) and long-acting trace minerals rumen bolus (TMB) supplements on performance, blood biochemical variables, and antioxidant status of the lambs under grazing conditions. The lambs were randomly distributed into four groups as follows: (1) untreated, (2) oral dose of 5 mL DFM, (3) TMB, or (4) oral dose of 5 mL DFM and TMB. The treatments were carried out for 90 days. Supplementation with TMB significantly increased (P < 0.05) average daily gain (ADG) and feed efficiency compared with the control. A significant (P < 0.05) increase in blood albumin in the DFM and a significant (P < 0.05) decrease in aspartate aminotrasferase were found in the lambs supplemented with TMB alone or in combination with DFM. Supplementing lambs with TMB resulted in higher glutathione peroxidase, total antioxidant capacity (P < 0.001) and activity of superoxide dismutase (P < 0.05) compared with no supplementation and supplementation with DFM only. In conclusion, TMB supplementation had a positive impact on performance traits and the antioxidant system of the lambs under grazing condition.

Evaluating the suitability of maggot meal as a partial substitute of soya bean on the productive traits, digestibility indices and organoleptic properties of broiler meat.

This study was conducted to replace soya bean meal with maggot meal at difference percentages. A total of 120 one-day-old broiler chicks were divided into four groups. Four diets were formulated with maggot meal to replace soya bean meal at the rate of 0%, 10%, 20% and 30% designated as A, B, C and D respectively. Feed and water were offered ad libitum during the study which lasted for 28 days. Feed intake decreased significantly in treated groups while body weight, Feed conversion ratio and dressing percentage increased significantly in group D. Apparent metabolizable energy increased significantly in the group fed 30% maggot meal; however, no significant difference was found in dry matter, crude protein, crude fibre, ether extract, ash and nitrogen free extract between the control and treated groups. The result of sensory evaluation revealed that tenderness and juiciness increased significantly in group C and B respectively. The colour and flavour were most accepted in group B and C. The results indicate that replacement of soya bean meal at the rate of 30% in broiler feed produced most favourable results.

Visceral phaeohyphomycosis caused by Alternaria alternata offering a diagnostic as well as a therapeutic challenge.

Phaeohyphomycosis is a heterogeneous group of opportunistic infections caused by dematiaceous molds, which are distributed worldwide as plant pathogens but rarely cause human diseases. However, due to the growing populations of immunocompromised patients, these fungi are frequently recognized as important human pathogens. We are reporting this very rare, unique case for the first time from Islamabad, Pakistan, describing the association of visceral Phaeohyphomycosis caused by the opportunistic fungus Alternaria alternata, affecting the left kidney, with the immunocompromised state in a young incidentally detected patient with insulin-dependent type I diabetes. The case was diagnosed on the basis of a high index of clinical suspicion, microbial cultures, microscopy, imaging studies and endourological procedures. The patient did not respond well to the highly sensitive Amphotericin B, resulting in loss of the kidney. Therefore, we suggest that clinicians involved in treating immunocompromised patients should have a high degree of clinical suspicion for such opportunistic pathogens to allow timely initiation of the correct diagnostic and therapeutic work-up.

In vivo adverse effects of alpha-tocopherol on the semen quality of male bucks.

Oxidative stress has detrimental effects on semen quality during spermatogenesis and semen processing for artificial insemination. This work was conducted to study the effect of different levels of vitamin E on the semen traits, oxidative status and trace minerals in Beetal bucks. Thirty-six bucks of similar body weight and age (1 year) were randomly divided into four groups. One group was kept as control with no supplementation (group 1), and the others were supplemented with 200 (group 2), 400 (group 3) and 800 IU (group 4) vitamin E/animal/day for 2 months. At the end of the experiment, semen samples were collected and evaluated. Seminal plasma was separated to study the concentration of superoxide dismutase (SOD), glutathione peroxidase (GPx), aspartate aminotransferase (AST), alanine aminotransferase (ALT) and trace minerals (Zn, Cu, Mn and Fe). Group 3 showed significantly higher (p < 0.05) semen volume and per cent motility and lower dead sperm percentage compared to control group. Superoxide dismutase, GPx, Zn, Cu and Mn were higher in the same group. The level of AST decreased in group 3 without any change on the concentration of ALT. It is suggested that vitamin E at the rate of 400 IU/buck/day supported higher semen volume, per cent motility, per cent live spermatozoa, antioxidants (SOD, GPx) and trace mineral levels (Zn, Cu, Mn) in the seminal plasma. The increased supplementation from 0 to 400 showed a general increasing trend in improving semen quality. However, the dose of 800 IU/kg had no useful effect in further improving the semen quality.

Influence of dietary zinc on semen traits and seminal plasma antioxidant enzymes and trace minerals of beetal bucks.

Zinc (Zn) is a potent antioxidant and plays a key role in scavenging free radicals. We hypothesized that supplementation of Zn would reduce the oxidative damage, which is linked with poor sperm quality. Sixteen bucks of similar average age (2 years) and body weight (41 kg) were randomly divided into four groups viz., 1, 2, 3 and 4 supplemented with zinc sulphate into the diet at the rate of 0, 50, 100 and 200 mg/buck/day, respectively, for 3 months. At the end of the experiment, semen samples were collected and assessed. Seminal plasma was separated to find the concentration of superoxide dismutase (SOD), glutathione peroxidase (GPx), aspartate aminotransferase (AST), alanine aminotransferase (ALT) and trace minerals (Zn, Cu, Mn and Fe). The results revealed that semen volume (1.85 ± 0.01 ml) and sperm motility (88.23 ± 5.77%) increased significantly (p < 0.05) in supplemented groups compared with the control specifically in group 3. SOD (10.66 ± 0.23 inhibition rate %) and GPx (23.55 ± 0.49 mU/ml) increased significantly (p < 0.05) in group 3 with no effect on AST and ALT. Among seminal plasma trace elements, no significant change (p > 0.05) was observed. From the present results, we concluded that zinc sulphate at the rate of 100 mg/buck/day improved semen traits and seminal plasma antioxidant capacity in Beetal bucks.

Antiparasitic effect of wild rue (Peganum harmala L.) against experimentally induced coccidiosis in broiler chicks.

Organic farming of poultry has increased in recent years as the prophylactic use of antibiotics has come into disfavor. This study was conducted to explore the antiparasitic effect of a methanolic extract of Peganum harmala in broilers challenged with coccidiosis. For this purpose, 200 1-week-old broiler chicks were divided into five treatments: negative control (basal diet, Ph-0/NC), positive control (basal diet with coccidiosis challenge, Ph-0/C), and three groups challenged with coccidiosis and supplemented with P. harmala at the rate of 200 mg L(-1) (Ph-200), 250 mg L(-1) (Ph-250), and 300 mg L(-1) (Ph-300) drinking water. Each group had three replicates of ten chicks each. Challenge with standard dose of the larvae of coccidiosis and supplementation of P. harmala were initiated on day 14 until 35 days of age. As expected, the results revealed that weight gain, feed intake, and feed conversion ratio (FCR) were depressed significantly in Ph-0 group with significant mortality percentage. Weight gain, total body weight, and FCR increased linearly with increasing dose of P. harmala with the exception of feed intake. The growth and feed efficiency of Ph-0/NC was better in Ph-0/NC compared to that in Ph-0/C and comparable to that in P. harmala-treated birds. Similarly, mean ooccytes per gram (OPG) decreased linearly (P < 0.05) in supplemented groups compared to that in Ph-0/C. Histological evidences showed that cecal lesion and leucocyte infiltration decreased markedly in supplemented groups of P. harmala specifically the Ph-300 group compared to those in Ph-0/C. From the present experiment, we concluded the anticoccidial effect of P. harmala in broiler chicks.

Effect of vitamins, protein level and probiotics on immune response of moulted male broiler breeders.

This study was planned to investigate the comparative effect of vitamins C (L-ascorbic acid), E (DL-α-tocopherol acetate), probiotics, lower than normal protein level (14%) and combination of these treatments on immune response of male broiler breeders after zinc-induced moulting. One hundred and eighty birds at the age of 65 weeks were induced to moult by mixing zinc oxide (ZnO) in feed at the rate 3000 IU/kg of feed. Upon completion of moulting, birds were divided into six groups (five replicates per group) in a completely randomized design and were fed vitamin C (500 IU/kg), vitamin E (100 IU/kg), lower protein level, probiotics (50 mg/l), and a combination of these components, while one group was kept as control. After completion of moulting phase (5 weeks), the treatment effects were tested as in vitro macrophages engulfment percentage, nitric oxide (NO) production, serum antibody titres against Newcastle disease (ND) and infectious bronchitis (IB). The results showed that in vitro macrophage engulfment percentage in unopsonized conditions was significantly higher in vitamin E-supplemented group. In addition, in opsonized condition, the macrophage engulfment percentage was significantly higher in both vitamin E- and C-supplemented groups. The NO (opsonized and unopsonized) production and antibody titre against ND and IB were significantly higher in vitamin E-supplemented group. It was concluded that vitamin E is a better option for enhanced immune response in broiler breeders after zinc-induced moulting.

Colour-causing defects and their related optoelectronic transitions in single crystal CVD diamond.

Defects causing colour in nitrogen-doped chemical vapour-deposited (CVD) diamond can adversely affect the exceptional optical, electronic and spintronic properties of the material. Several techniques were used to study these defects, namely optical absorption spectroscopy, thermoluminescence (TL) and electron paramagnetic resonance (EPR). From our studies, the defects causing colour in nitrogen-doped CVD diamond are clearly not the same as those causing similar colour in natural diamonds. The brown colour arises due to a featureless absorption profile that decreases in intensity with increasing wavelength, and a broad feature at 360 nm (3.49 eV) that scales in intensity with it. Another prominent absorption band, centred at 520 nm (2.39 eV), is ascribed to the neutral nitrogen-vacancy-hydrogen defect. The defects responsible for the brown colour possess acceptor states that are 1.5 eV from the valence band (VB) edge. The brown colour is removed by heat treatment at 1600 ° C, whereupon new defects possessing shallow (<1 eV) trap states are generated.

Effect of vitamins, probiotics and protein level on semen traits and seminal plasma biochemical parameters of post-moult male broiler breeders.

1. A study was designed to investigate the comparative effect of supplementary vitamin E, vitamin C, probiotics and dietary crude protein concentration on semen traits and seminal plasma biochemical parameters in male broiler breeders after Zn-induced moulting. 2. A total of 180 male broiler breeders were induced to moult at 65 weeks of age by mixing ZnO in diet at the rate 3000 mg/kg of feed. After moulting, the males were divided into six groups that were given feed supplemented with: vitamin C (500 IU/kg), vitamin E (100 IU/kg), protein (140 g CP/kg), probiotics (50 mg/kg) and the combination of these components, while one group was kept as a control. Semen samples were collected weekly and semen volume, spermatozoa concentration, motility and dead spermatozoa percentage were determined. Seminal plasma was separated to determine the concentration of total antioxidant capacity (TAC), homocysteine, paraoxonase (PON1), arylesterase, ceruloplasmin, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities. 3. Semen volume was significantly higher in the vitamin E and C groups compared to the control. Spermatozoa motility was higher in the vitamin E group and dead spermatozoa percentage was significantly lower in the vitamin C group compared with the control group. 4. Seminal plasma TAC was higher in the vitamin E group, homocysteine was lower in the vitamin C and E groups. PON1 was higher in the combination group. Arylesterase increased significantly in the vitamin C and combination groups over time. Seminal plasma AST was significantly lower in the vitamin C and E supplemented groups whereas ALT decreased significantly only in the vitamin E group compared with the control. Higher concentrations of ceruloplasmin were observed in the combination group compared with the other treatments. 5. It was concluded that additional vitamin E and C or their combination was the most potent nutrient treatment for improving the semen traits and seminal plasma biochemical characteristics in male broiler breeders after Zn-induced moulting.

Luminescence lifetimes of neutral nitrogen-vacancy centres in synthetic diamond containing nitrogen.

The decay time of luminescence from neutral nitrogen-vacancy (NV(0)) centres in synthetic diamond is reported. The intrinsic luminescence lifetime of NV (0) is measured as τ(r) = 19 ± 2 ns. Neutral substitutional nitrogen atoms (N(S)(0)) are shown to quench luminescence from NV(0) by dipole-dipole resonant energy transfer at a rate such that the transfer time would equal τ(r) if one (N(S)(0)) atom was ~3 nm from the NV(0). In chemical-vapour-deposited diamonds grown with a small nitrogen content, that are brown as a result of vacancy-cluster defects, the decay time of NV(0) equals τ(r) in the as-grown material. However, after annealing at ≥1700 °C to remove the brown colour, luminescence from the NV(0) centres is severely quenched. This effect is suggested to be a result of the destruction of NV(0) centres and the creation of new NV(0) centres localized in vacancy-rich regions of the crystals.

Effect of vitamins, probiotics and protein on semen traits in post-molt male broiler breeders.

The study aimed to investigate the comparative effect of vitamins E and C, probiotics, lower than normal protein level and the combination of these treatments in male broiler breeders after Zn-induced molting. One hundred and eighty birds at 65 weeks of age were divided into six groups (five replicates per group) in a completely randomized block design. Birds were induced to molt by mixing zinc oxide in feed at the rate of 3000 mg/kg of feed. Upon completion of molting, birds were fed different supplements. One group was kept as a control, while the other groups were fed: vitamin E (100 IU/kg), vitamin C (500 IU/kg), probiotics (50 mg/L of water), lower dietary protein level (14%) or the combination of these treatments. Results revealed that vitamins (E and C) supplementation increased (P<0.05) semen volume, however, sperm motility and egg fertility were significantly higher only in vitamin E supplemented group compared to control. The dead sperm percentage decreased (P<0.05) in vitamin C fed group, whereas, sperm concentration did not differ (P>0.05) between the control and treated groups. The results validate the key role of antioxidant vitamins in male broiler breeders' fertility after Zn-induced molting.

Malignant glomus tumour of larynx: first case report and literature review.

OBJECTIVE: We describe the first reported case of a malignant glomus tumour of the larynx. METHOD: Case report and review of the world literature concerning malignant glomus tumours. RESULTS: A 37-year-old man presented with progressive hoarseness and dyspnoea. A smooth, right-sided laryngeal mass was found on flexible nasolaryngoscopy. Initial biopsy of this lesion was reported as a true 'glomus tumour', which is a benign lesion. Wide local excision was performed. The final histology of this specimen showed it to be a 'malignant glomus tumour'. Immunohistochemistry was positive for smooth muscle actin, collagen type IV, vimentin and cluster of differentiation 34 glycoprotein. Total laryngectomy was then performed as a definitive curative procedure. CONCLUSION: Glomus tumour is rarely found in visceral locations. This tumour and its malignant counterpart are rare differential diagnoses of laryngeal masses.

Productive performance and histological features of intestinal mucosa of broiler chickens fed different dietary protein levels.

To evaluate the effect of decreasing dietary protein on growth performance, carcass traits, and intestinal mucosal morphometry, 180 female Hubbard strain broiler chickens were divided into 3 groups and fed 3 isoenergetic diets ad libitum from 14 d of age until slaughter age (49 d). The treatments varied according to 3 protein levels: high-protein diet (HiP, 22.5% CP, DM basis), medium-protein diet (MedP, 20.5% CP), and low-protein diet (LowP, 18.5%). Diets were obtained by replacing wheat middlings with soybean meal and were formulated to meet or exceed broiler amino acid requirements of the NRC. Morphometric indices of duodenum, jejunum, and ileum were measured at the end of the feeding period and included villus height, crypt depth, villus-to-crypt ratio, and apparent villus surface area. The dietary protein level had a significant effect on final BW of birds, whereas ADG, ADFI, and feed efficiency remained unaffected by dietary treatment. The muscle (breast and drumstick) yields were significantly higher in birds fed the HiP diet compared with those of the MedP and LowP diets. Meat quality traits were not affected by the protein level. The villus surface area of all intestinal segments did not change among groups. Instead, reducing the dietary protein level to 20.5% resulted in a higher villus height and villus height to crypt depth ratio in the duodenum and ileum. On the basis of our findings, even if the high-protein diet promoted meat yield, a medium-protein diet could positively support broiler growth performance, as confirmed by favorable morphometric features of the intestine.

Semen traits and seminal plasma biochemical parameters in white leghorn layer breeders.

This study was designed to determine the semen quality and seminal plasma biochemical parameters in White Leghorn layer breeders in the early phase of maturity. Individual ejaculates from 25 males were analysed for the determination of volume, sperm concentration, dead sperm percentage (DS) and sperm motility. Seminal plasma was separated and analysed for total oxidant status (TOS), total antioxidant capacity (TAC), paraoxonase (PON1), arylesterase, ceruloplasmin, triiodothyronine, thyroxine, aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Our findings showed a significant (p < 0.05) positive correlation between TOS and DS in layer breeders. The values of TAC were significantly negatively correlated with TOS and DS, while positively correlated with PON1. Conversely, AST showed significant negative correlation with motility and DS. Significantly, negative correlation was also observed between ALT and sperm concentration. In conclusion, these parameters provide some valuable basal data that may help better understanding the semen quality characteristics of White Leghorn layer breeders.

Time dependence of charge transfer processes in diamond studied with positrons.

We have developed a method called optical transient positron spectroscopy and apply it to study the optically induced carrier trapping and charge transfer processes in natural brown type IIa diamond. By measuring the positron lifetime with continuous and pulsed illumination, we present an estimate of the optical absorption cross section of the vacancy clusters causing the brown color. The vacancy clusters accept electrons from the valence band in the absorption process, giving rise to photoconductivity.