Solution electrospinning of polypropylene-based fibers and their application in catalysis

Since the dissolution of polyolefins is a chronic problem, melt processing has been tacitly accepted as an obligation. In this work, polypropylene (PP) was modified on molecular level incorporating poly(ethylene glycol) (PEG) as graft segment (PP-g-PEG) in a range of 6 to 9 mol%. Gold nanoparticles were nucleated in the presence of the copolymer chains via redox reaction. The dissolution of the amphiphilic comb-type graft copolymers containing gold nanoparticles (80 nm in diameter) was achieved in toluene and successfully electrospun from its solution. The diameter of composite fibers was in the range from 0.3 to 2.5 μm. The design of the structurally organized copolymer fiber mats provided a support medium for the nanoparticles enhancing the active surface area for the catalytic applications. The resulting composite fibers exhibited rapid catalytic reduction of methylene blue (MB) dye in the presence of sodium borohydride (NaBH₄) compared to corresponding composite cast film.     

Adaptation of endemic mediterranean Sternbergia candida Mathew Et T. Baytop in the continental climate of central anatolia

Sternbergia candida is an important endemic bulbous plant with beautiful white flowers. It grows on the rock slopes of Baba mountains under Lebanon Cedars in the Mugla province of Turkey with Mediterranean climate. The plant is vulnerable and endangered due to illegal collection for local and foreign flower industry. Fast developing tourism industry and rapid urbanization has also shown negative implications on its population. The study reports three years successful adaptation results of S. candida in the continental climate of Ankara in the Central Anatolia. Four groups of bulbs based on diameter (>2.45, 2.15–2.44, 1.85–2.14 and <1.84 cm) were collected from its natural habitat during March, April and May 1998 and were evaluated for frequency (%) of emergence, mean number of leaves per plant, mean plant height, frequency (%) of flowering, frequency (%) of fruit setting. mean number of bulbs per plant, and mean diameter (cm) of regenerated bulbs. All categories of bulbs could be multiplied and adapted successfully with variable frequency of fruit setting. However, the highest fruit set was recorded from 2.15–2.44 cm April collected bulbs. This indicated that the bulb diameter and collection time had clear implications on multiplication, propagation and adaptation of the plant.     

Development of energy generating photovoltaic textile structures for smart applications

The aim of this study is to develop a method with lower application temperature and a device structure to obtain reproducible photovoltaic textiles. Two different kinds of poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) solutions over a silver (Ag) layer was used as anode, a blend of poly(3-hexyl thiophene) (P3HT) and [6,6]-phenyl C61-butyric acid methyl ester (PCBM) as light absorbing layer and a thin aluminum (Al)/Ag layer as semi-transparent cathode. These devices capable of generating electricity from sunlight were fabricated on polypropylene tapes that could be woven into a textile fabric. The short-circuit current density and power conversion efficiency of photovoltaic tapes were increased by using an Ag layer beneath the PEDOT:PSS electrode. The photovoltaic textile structure exhibited remarkable power conversion efficiency (0.29 %) by transmitting the light through the upper electrode. This approach may be used in industrial applications to develop photovoltaic textile materials.     

Investigation of the antibiotic resistance and biofilm formation of Staphylococcus aureus strains isolated from gangrenous mastitis of ewes

In this study, Staphylococcus aureus strains (n = 110) isolated from seven ewe flocks in Sanliurfa, Turkey were screened for antibiotic resistance and biofilmforming ability as well as for genes associated with antibiotic resistance and biofilm-forming ability. All isolates were found to be susceptible to oxacillin, gentamicin, clindamycin, cefoxitin, tetracycline, vancomycin, amoxicillin-clavulanic acid, ciprofloxacin and sulphamethoxazole-trimethoprim. The percent proportions of strains resistant to penicillin G, ampicillin and erythromycin were 27.2% (n = 30), 25.4% (n = 28) and 6.3% (n = 7), respectively. Regarding the antibiotic resistance genes, 32 (29%) isolates carried the blaZ and 8 (7.2%) the ermC gene. Other resistance genes were not detected in the isolates. All isolates showed biofilm-forming ability on Congo red agar (CRA), while 108 (98.18%) and 101 (91.81%) of them were identified as biofilm producers by the use of standard tube (ST) and microplate (MP) methods, respectively. All isolates carried the icaA and icaD genes but none of them harboured the bap gene. The results demonstrated that S. aureus isolates from gangrenous mastitis were mainly resistant to penicillins (which are susceptible to the staphylococcal beta-lactamase enzyme), and less frequently to erythromycin. Furthermore, all of the S. aureus isolates produced biofilm which was considered a potential virulence factor in the pathogenesis of staphylococcal mastitis.     

Detection of superantigenic toxin genes in Staphylococcus aureus strains from subclinical bovine mastitis

The aim of this study was to determine the presence of genes encoding enterotoxins (sea-sej) and toxic shock syndrome toxin-1 (tst) of Staphylococcus aureus strains (n = 130) isolated from subclinical bovine mastitis in Turkey by polymerase chain reaction. Sixty-one (46.9%) isolates were found to contain one or more toxin genes. The most frequently found enterotoxin genes were seg (16.2%) and sei (16.2%), followed by sec (15.4%), sed (10.8%), and sej (10.8%), respectively. The tst gene was detected in seven (5.4%) isolates. None of S. aureus strains harbored sea, seb, see, and seh genes. Since these toxins are recognized agents of staphylococcal food poisoning, it must be considered that the consuming raw milk and raw milk products would pose public health risk as high prevalence of toxigenic S. aureus was found in this study.     

The influence of different beak trimming age on performance, H-L ratio and antibody production to SRBC in laying hens

The objectives of this study were to examine the effects of beak trimming age on performance criteria, H-L ratio, antibody production, the percentage of spleen and liver and external appearance. The chicks (Barred Rock) were randomly divided into 4 beak-trimming groups (non-trimmed (control), a trim at 1 d (1D), at 10 d (10D) and at 10 wk (10W)), each of 132 chicks. There were 6 replicate cages at beak trimming groups at rearing period. At 18 wk of age a total of 144 pullets were transferred to the layer house, and the pullets were housed at 323 and 646 cm²/hen with 8 and 4 birds per cage in three-deck layer cages. There were a total of 24 replications with 12 replications equally divided between the high and low density cages, and the beak trimmed treatments were randomly and equally divided within each density. As a result of this experiment differences among groups in body weight in rearing phase were disappear in the laying phase. Low feather condition was found in untrimmed hens. H-L ratio in both pullet and laying phase was higher in hens of untrimmed groups. Cage area affected all examined parameters except that body weight, mortality rate, cracked, broken and unshell egg rates, shell breaking, shape index, shell thickness, meat-blood spot rates, spleen and liver percentages, throat injures and antibody production to SRBC.