bluuebunny/crossref_metadata_2025 huggingface dataset:
Donor Sperm Insemination Cycles: Are Two Inseminations Better Than One?
Authors: Chavkin Diana E. , Molinaro Thomas A. , Roe Andrea H. , Sammel Mary D. , Dokras Anuja
Published: May 2012

ABSTRACT: The objective of this study was to determine the clinical pregnancy rate with 2 inseminations compared to a single intrauterine insemination (IUI) in a given cycle using frozen‐thawed donor sperm. This was a retrospective study at a university practice; patients were women using donor sperm. We conducted a comparison of single IUI, intracervical insemination (ICI) followed by an IUI on the next day, and double IUI (2 consecutive days); clinical pregnancy rate was the main outcome measure. The cycle‐specific and total pregnancy rates were not significantly different between the 3 protocol groups (306 cycles). The average pregnancy rate over 3 cycles was 10.2% for IUI, 15.3% for ICI/IUI, and 13.7% for IUI/IUI (P = .47). After controlling for repeated measures per subject and age, gravidity, and use of Clomid, there was no significant difference between protocols. The ICI/IUI (odds ratio [OR] = 1.70; 95% confidence interval [CI], 0.83–3.51) and IUI/IUI (OR = 1.5; 95% CI, 0.52–4.33) protocols appeared more likely to result in a clinical pregnancy than the single IUI protocol. Current information on the optimal number of inseminations per cycle using donor sperm is limited. Our large study using 3 protocols found an increase in pregnancy rate with the addition of either an ICI or IUI to a single IUI protocol in a natural or Clomid cycle but did not meet statistical significance. Additional prospective studies are needed to better counsel patients using donor sperm.
Effects of Varicocelectomy on Sperm DNA Fragmentation, Mitochondrial Function, Chromatin Condensation, and Apoptosis
Authors: La Vignera Sandro , Condorelli Rosita , Vicari Enzo , D'Agata Rosario , Calogero Aldo E.
Published: May 2012

ABSTRACT: The aim of this study was to evaluate conventional semen parameters (density, morphology, and progressive motility) and the flow‐cytometric parameters of DNA fragmentation, mitochondrial membrane potential, phosphatidylserine externalization, and chromatin compactness in patients with varicocele before and after varicocelectomy. Thirty men (26.5 ± 3.2 years old, range 20–32 years) with oligoasthenoteratozoospermia and grade 3 left varicocele were selected (without other causes of male infertility). Each of them underwent sperm analysis and flow cytometric evaluation before and 4 months after subinguinal microsurgical varicocelectomy (SMV). After varicocelectomy, men had significantly higher sperm density, progressive motility, and normal forms compared with baseline. They also had a significantly lower percentage of spermatozoa with low mitochondrial membrane potential. After SMV, they showed a significantly lower percentage of spermatozoa with phosphatidylserine externalization, an early sign of apoptosis. Significantly decreased percentages of spermatozoa with abnormal chromatin compactness and spermatozoa with DNA fragmentation were found after SMV compared with baseline. Subinguinal microsurgical varicocelectomy improves sperm function in oligoasthenoteratozoospermia secondary to grade 3 left varicocele. Improvements are seen in conventional parameters and biofunctional parameters not routinely evaluated.
The Effects of Low‐Level Laser Light Exposure on Sperm Motion Characteristics and DNA Damage
Authors: Firestone Ross S. , Esfandiari Navid , Moskovtsev Sergey I. , Burstein Eliezer , Videna German T. , Librach Clifford , Bentov Yaakov , Casper Robert F.
Published: May 2012

ABSTRACT: The objective of this study was to determine the effects of low‐level laser light exposure on the motility of spermatozoa and on DNA damage. Thirty‐three semen samples were collected for routine analysis and were classified as normospermic, oligospermic, or asthenospermic. After routine semen analysis was performed, residual semen was divided into treated and control aliquots. Treated samples were exposed to a 30‐second infrared laser pulse of 50 mW/cm2 at 905 nm, a wavelength thought to increase light‐sensitive cytochrome c oxidase in the mitochondrial electron transport chain. Samples were then incubated at 37°C, and aliquots were analyzed at 30 minutes and 2 hours using computerassisted semen analysis. After incubation, 250 μL of each sample was frozen at 280°C until DNA fragmentation analysis by flow cytometry. A significant increase in motility, most prominent in oligospermic and asthenospermic samples (85% increase), was observed 30 minutes after the treatment (P < .0001). No significant increase in DNA damage compared with control samples was observed. Significant changes in sperm motion kinetics were observed. Low‐level laser light exposure appears to have a positive short‐term effect on the motility of treated spermatozoa and did not cause any increase in DNA damage measured at 2 hours. We conclude that some cases of asthenospermia may be related to mitochondrial dysfunction. The implications of this study in terms of future clinical applications needs further investigation.
The Impact of Transurethral Procedures for Benign Prostate Hyperplasia on Male Sexual Function: A Meta‐Analysis
Authors: Zong Huan‐Tao , Peng Xiao‐Xia , Yang Chen‐Chen , Zhang Yong
Published: May 2012

ABSTRACT: The effect of transurethral procedures for benign prostate hyperplasia (BPH) on male sexual function is still controversial, and we conducted this meta‐analysis to compare the effects of different transurethral surgical procedures for the treatment of symptomatic BPH on male erectile function (EF) and ejaculatory function (EJF). Databases, including MEDLINE, EMBASE, and the Cochrane Controlled Trial Register, were searched to identify randomized controlled trials (RCT) that compared watchful waiting, transurethral electrovaporization (TUEVP) or holmium laser treatment (HLT) with transurethral resection of the prostate (TURP). Trials were included if they were RCTs, contained fully available data, compared with conventional TURP for BPH, and referred to male EF and EJF. A total of 12 RCTs involving a total of 1889 subjects were selected for analysis, including 2 trials comparing TURP and watchful waiting, 6 comparing TURP with TUEVP, and 4 comparing TURP with HLT. TURP was associated with a higher occurrence of retrograde ejaculation compared with watchful waiting but not to TUEVP (P = .95) or HLT (P = .37) and associated with a lower incidence of male erectile dysfunction compared with TUEVP (P = .04) but not HLT. According to the analysis, TURP lead to a higher prevalence of retrograde ejaculation compared with watchful waiting but had less of an effect on EF than TUEVP. TURP did not have a significantly different effect on EF or EJF compared with HLT.
Urinary Concentrations of Di(2‐ethylhexyl) Phthalate Metabolites and Serum Reproductive Hormones: Pooled Analysis of Fertile and Infertile Men
Authors: Mendiola Jaime , Meeker John D. , Jørgensen Niels , Andersson Anna‐Maria , Liu Fan , Calafat Antonia M. , Redmon J. Bruce , Drobnis Erma Z. , Sparks Amy E. , Wang Christina , Hauser Russ , Swan Shanna H.
Published: May 2012

ABSTRACT: Urinary concentrations of metabolites of the anti‐androgenic xenobiotic di‐(2‐ethylhexyl) phthalate (DEHP) were previously shown to be weakly associated with serum levels of several hormones in 2 disparate US populations: partners of pregnant women participating in the Study for Future Families and partners in infertile couples from Massachusetts General Hospital infertility clinic. The observed associations between phthalate metabolites and reproductive hormones were robust and insensitive to the characteristics of the subpopulation or the laboratory in which the hormones were measured, despite the fact that these 2 populations span a range of fertility, urinary phthalate metabolites, and reproductive hormone levels. We therefore examined associations between urinary metabolites of DEHP and reproductive hormones—follicle‐stimulating hormone, luteinizing hormone, testosterone (T), inhibin B, and estradiol (E2)—and sex hormone–binding globulin (SHBG) in the pooled population. The magnitude of the associations seen were similar to those reported for each population separately, but effect estimates were more precise because of the increased sample size and the greater range of phthalate metabolite concentrations and hormone levels. Urinary concentrations of 3 metabolites of DEHP[mono(2‐ethylhexyl) phthalate (MEHP), mono(2‐ethyl‐5‐hydroxyhexyl) phthalate (MEHHP), and mono(2‐ethyl‐5‐oxohexyl) phthalate (MEOHP)] were inversely associated with the free androgen index (FAI = T/SHBG) and calculated free testosterone. Urinary concentrations of MEHHP and MEOHP were positively associated with SHBG, and MEHP was inversely associated with E2. No other phthalate metabolites were associated with serum hormones, consistent with results in each population. Our results in this diverse population suggest that DEHP exposure is robustly associated with some male sex steroid hormones.
A Novel Nonsense Mutation in the Androgen Receptor Gene Causes the Complete Androgen Insensitivity Syndrome
Authors: Liu Xiaoyi , Fu Jiao , Cai Zhen , Sun Liang , Zhang Xiaoyan , Li Zesong , Diao Ruiying , Wang Zihui , Yu Guangyin , Cai Zhiming , Gui Yaoting
Published: May 2012

ABSTRACT: We identified an unusual novel nonsense mutation in exon 3 of the androgen receptor (AR) gene in a patient with complete androgen insensitivity that was persistence of Wolffian derivatives. Sequence analysis revealed a substitution (C→T) at position 2211 and a deletion of G at position 2213 in exon 3 of the AR gene, resulting in theconversionofarginine(CGG) toastop codon (TGA) of the AR. Western blotting demonstrated a truncated AR with around 70 kd was expressed. Histology of patient's testes showed that seminiferous tubules were totally filled with Sertoli cells without germ cells. Immunohistochemistry revealed positive AR localization in the nuclei of Sertoli cells and epithelia of efferent ductule and vas deferens. AR immunoexpression was stronger in the epithelia of efferent ductule and vas deferens than in Sertoli cells. The study extends the spectrum of exon 3 mutations in the AR gene.
Orthogonal Polarization Spectral Imaging: A Novel Tool for Examination of Microcirculatory Changes in the Testis
Authors: Bajory Zoltán , Szabó Andrea , Deák Gábor , Varga Renáta , Pajor László
Published: May 2012

ABSTRACT: Testicular torsion is a surgical emergency in urologic practice. Many models have demonstrated the relationship between the degree and duration of the torsion and the subsequent damages of the testis, but there are as yet no suitable methods for visualization of the testicular microcirculation in this condition. We aimed to use orthogonal polarization spectral (OPS) imaging to observe the microcirculatory changes in the testis after ischemia‐reperfusion (I/R) challenge, and to compare this technique with that of fluorescence intravital video microscopy (IVM). Twelve rats subjected to 60‐minute ischemia following 720° testicular torsion were divided into two groups for IVM or OPS imaging examinations of the microcirculatory network of the testis at 60, 120, 180, and 240 minutes after reestablishment of perfusion. Significant microcirculatory failure was demonstrated after I/R in both groups. The absolute values of the microcirculatory parameters recorded with the OPS and IVM imaging methods did not differ statistically. The microcirculatory disturbances are present during the later phases of testicular torsion. OPS imaging technique represents an accurate noninvasive method to detect physiologic and pathophysiologic changes in the microcirculation of the testis.
Glans‐Preserving Surgery for Superficial Penile Cancer
Authors: Li Pengchao , Song Ninghong , Yin Changjun , Zhang Wei , Li Jie , Hua Lixin , Wang Zengjun , Cheng Gong
Published: May 2012

ABSTRACT: In this study, we investigated the safety and feasibility of glans‐preserving surgery for superficial penile squamous cell carcinoma. Young patients with penile primary tumors exhibiting favorable histologic features were best suited for organ‐sparing procedures, enabling them to avoid sexual disturbances. The study included 12 patients, 38–53 years of age (median age 46 years), with superficial lesions involving the glans penis, coronary sulcus, or shaft skin. After clinical staging and grading, those patients were offered a glans‐preserving procedure to preserve the normal appearance and functional integrity of the glans penis. Of the 12 patients referred, the tumors were TaG1 in 4 patients, TaG2 in 3, TisG1 in 1, TisG2 in 1, T1G1 in 2, and T1G2 in 1. All patients returned to normal sexual activity 1 month postoperatively. Sexual function and sexual satisfaction were well maintained after surgery. The cosmetic results were considered satisfying/very satisfying by 83% (10 of 12 patients). Follow‐up data were available on 12 patients at a mean follow‐up of 62.5 months. Only 1 patient had recurrence 6 months after surgery, which was managed by a second glans‐preserving surgery without recurrence. With careful patient selection and vigilant follow‐up, anatomically suitable superficial penile cancer can be offered this glans‐preserving surgery, while preserving function of the penis wherever possible.
Male Accessory Gland Infection Frequency in Infertile Patients With Chronic Microbial Prostatitis and Irritable Bowel Syndrome: Transrectal Ultrasound Examination Helps to Understand the Links
Authors: Vicari Enzo , Calogero Aldo E. , Condorelli Rosita A. , Vicari Lucia O. , La Vignera Sandro
Published: May 2012

ABSTRACT: The aim of this study was to evaluate the frequency of male accessory gland infection (MAGI) in patients with chronic bacterial prostatitis (CBP) plus irritable bowel syndrome (IBS) and to compare the sperm parameters of patients with or without MAGI. In addition, another objective of this study was to evaluate the ultrasound characterization of the anatomical space between the posterior wall of the prostate and the anterior wall of the rectum using transrectal ultrasonography. Fifty consecutive patients with the following criteria were enrolled: 1) infertility, 2) diagnosis of CBP, and 3) diagnosis of IBS according to the Rome III criteria. The following 2 age‐matched control groups were also studied: infertile patients with CBP alone (n = 56) and fertile men (n = 30) who had fathered a child within the previous 3 months. Patients and controls underwent an accurate patient history; administration of the National Institutes of Health–Chronic Prostatitis Symptom Index and the Rome III questionnaires for prostatitis and IBS, respectively; physical examination; semen analysis; and transrectal ultrasound evaluation (limited to patients with CBP and IBS or CBP alone). A significantly higher frequency of MAGI was found in patients with CBP plus IBS (82.0%) compared with patients with CBP alone (53.6%) or fertile men (0%). The presence of MAGI in patients with CBP plus IBS was associated with a significantly lower sperm concentration, total number, and forward motility, and with a higher seminal leukocyte concentration compared with patients with CBP alone and MAGI. Sperm normal morphology was similar in the groups of patients. All sperm parameters did not differ significantly in both groups of patients without MAGI. With ultrasound evaluation, a significantly higher frequency of dilatation of prostatic venous plexus was found in patients with CBP plus IBS (75%) compared with patients with CBP alone (10%). Patients with CBP plus IBS had a significantly higher frequency of MAGI compared with patients with CBP alone. This was associated with worse sperm parameters and, hence, poorer reproductive prognosis. We suggest searching for the presence of IBS in patients with prostatitis syndrome, in particular when CBP and/or worse sperm parameters are present. Finally, this is the first observation on ultrasound examination of the anatomical space between the posterior wall of the prostate and the anterior wall of the rectum reported in patients with CBP and IBS. Further studies should clarify the meaning of the ultrasound findings.
Arterial Erectile Dysfunction: Reliability of Penile Doppler Evaluation Integrated With Serum Concentrations of Late Endothelial Progenitor Cells and Endothelial Microparticles
Authors: La Vignera Sandro , Vicari Enzo , Condorelli Rosita A. , di Pino Luigi , Calogero Aldo E.
Published: May 2012

ABSTRACT: We recently showed the diagnostic value of a new immunophenotype of blood endothelial progenitor cells (EPC) (CD45−/CD34+/CD144+) and endothelial microparticles (EMP) (CD45−/CD144+/annexin V+) in patients with arterial erectile dysfunction (AED), particularly in patients with associated late‐onset hypogonadism and/or metabolic syndrome. In addition, we evaluated the effects of androgen replacement therapy, aerobic physical activity, and tadalafil administration on these markers. The aim of this study was to evaluate the serum concentrations of EPCs and EMPs in a large cohort of patients with AED according to severity of cavernous arterial insufficiency evaluated by penile Doppler. A total of 120 patients (aged 58.0 ± 6.0 years) with AED were enrolled in this study. Patients were classified into 3 groups based on value of peak systolic velocity (PSV). Group A: 37 patients with PSV <25 cm/s (severe arterial insufficiency); group B: 40 patients with PSV between 25 and 29 cm/s (moderate arterial insufficiency); group C: 43 patients with PSV between 30 and 34 cm/s (mild arterial insufficiency). Twenty patients (aged 60.0 ± 3.0 years) with psychogenic erectile dysfunction (PED) represented the control group. EPC and EMP blood concentrations were evaluated by flow cytometry. Patients with AED had significantly higher blood pressure, triglyceride levels, homeostasis model assessment index of insulin resistance, cavernous artery acceleration time, and intima‐media thickness than those with PED, whereas International Index of Erectile Function score, high‐density lipoprotein cholesterol level, and cavernous artery PSV were lower than those in PED. Both EPC and EMP levels were significantly higher in patients with AED compared with patients with PED. Among 3 groups of patients with AED, there were no significant differences in metabolic parameters examined, but group A showed significantly higher values of cavernous artery acceleration time and intima‐media thickness than group B and group C. Finally, group A showed serum concentrations of EPCs and EMPs significantly higher compared with other groups with AED. Patients with AED showed worse metabolic parameters, cavernous artery parameters, and EPC and EMP levels compared with patients with PED. Among patients with AED, those with PSV <25 cm/s showed worse findings of endothelial dysfunction. This suggests that AED is an expression of endothelial damage and that this original immunophenotype of EPCs and EMPs may be considered a predictor of endothelial dysfunction in patients with AED. Finally, this study confirmed the reliability of penile Doppler evaluation integrated with these serum markers of endothelial dysfunction.
Investigation of antibacterial activity of cinnamyl derivatives of arylpiperazine
Authors: Novakovic Irena , Penjisevic Jelena , Sukalovic V. , Andric Deana , Roglic G. , Kostic-Rajacic Sladjana
Published: May 2012

The derivatives of cinnamic acid and N-arylpiperazine show antibacterial
activity. In this work the potential synergistic effect of cinnamyl
derivatives of arylpiperazine in selected bacteria was investigated. The
antibacterial activities of the derivatives were evaluated against
Gram-positive bacteria: Staphylococcus aureus, Streptosporangium longisporum,
Sarcina lutea, Micrococcus flavus, Clostridium sporogenes and Bacillus
subtilis and Gram-negative bacteria: Escherichia coli, Pseudomonas
aeruginosa, Salmonella enteritidis and Proteus vulgaris by the disc diffusion
method. The minimum inhibitory concentration (MIC) against the selected
bacteria was determined for all compounds that showed activity in the disc
diffusion method. The majority of the investigated compounds displayed in
vitro antibacterial activity. The effect of the type and structure of the
substituent on the aromatic ring on the antibacterial activity is discussed.
It was found that two derivatives expressed activity toward S. longisporum
and P. aeruginosa that was almost as strong as that of amikacin.
Geographical and biological analysis of the water quality of Moravica spring in the Sokobanjska Moravica drainage basin, Serbia
Authors: Stankovic S. , Zlatkovic S. , Sabic D. , Milincic M. , Vujadinovic Snezana , Knezevic-Vukcevic Jelena
Published: May 2012

In this work we performed a geographical analysis of the Moravica spring
locality in the Sokobanjska Moravica drainage basin in Serbia, as well as an
analysis of the physical, chemical, and biological parameters of the water
during a one-year period. The basic sanitary characteristics and physical,
chemical, and biological parameters, necessary for understanding locality
conditions, were studied, and the saprobity index, class of quality, O/H
index, degree of saprobity, degree of trophicity, and category based on the
phosphatase activity index (PAI) were determined. Our results point to the
need for continual monitoring of the water quality in the spring locality.
Some characters of the pollen of spring and summer flowering common oak (Quercus robur L.)
Authors: Batos Branislava , Miljkovic Danijela , Bobinac M.
Published: May 2012

Summer flowering of the common oak is a natural rarity, considering the large
area of the species natural distribution. This phenomenon can be classified
as an ancestral (atavistic) property. Pollen morphological and physiological
characters from spring flowering male inflorescences collected over the
period 2004 - 2007 and summer flowering male inflorescences collected in 1999
were compared. The analysis included the pollen of a tree with frequent
summer flowering and a control tree with spring flowering only. The size and
form of summer pollen differed from the spring flowering pollen. The
germination percentage and germination energy depended on the pollen growing
medium (0, 5, 10, 15, 20, 25% sucrose solution), year of collection (2004 -
2007), temperature (+5?C and -20?C) and storage period (1 to 24 months). The
study results are significant for the explanation of common oak phylogenetic
development, and they contribute to the knowledge of pollen characters under
the effects of different factors.
Sex expression in Serbian dendroflora: A case study of Fraxinus ornus var. angustifolia
Authors: Popovic Zorica , Stefanovic Milena , Smiljanic Miroslava , Matic Rada , Kostic M. , Vidakovic Vera , Bojovic S.
Published: May 2012

Out of a total number of tree species in Serbian flora, 28% are
hermaphrodites, 43% are monoecious and 29% are dioecious. The dendroflora
appears to have a larger proportion of unisexual than hermaphrodite species.
The monoecious system is the dominant unisexual system within the tree
species in Serbia. The possible sex differentiation by RAPD markers and
Correspondence Analysis was examined in a population of Fraxinus ornus var.
angustifolia. On the basis of 6 selected RAPD bands which contribute to the
differentiation in frequency between male and hermaphrodite individuals,
Correspondence Analysis visualized the following tendency: 20 trees of each
variety were separated into two groups that mainly correspond to sexual
types. Our results showed that RAPD markers assisted by Correspondence
Analysis could be used in identifying male and hermaphrodite individuals in
F. ornus varieties.
Tropic responses of potato single-node explant cultures
Authors: Vinterhalter D. , Vinterhalter Branka
Published: May 2012

A special in-vitro protocol was elaborated enabling the production of potato
single-node explant plantlets that can be used as objects for tropic studies.
In light-grown plantlets, achievement of a full (90?) phototropic (PT)
curvature required 75 to 120 min of continuous unilateral blue light
irradiation or 120-135 min of gravitropic stimulation (GT). Time-lapse
photography revealed that the curves describing PT and GT bending have a
sigmoid shape. Continuous BL irradiation was necessary for the induction of
continuous PT bending. If the BL was turned off after 30-50 min of PT
stimulation, the bending gradually decreased and stopped in darkness after
25.0 ? 2.0 min. Within this period, curvature increased by 15.5 ? 1.5?. When
the BL was turned off upon completion of PT bending (when the plantlets
reached an angle of 90?), the plantlets entered the phase of fast
straightening. The 90? PT curvature was significantly exaggerated in darkness
by turning the jars from a vertical to horizontal position providing 120.74 ?
2.5? as the final curvature angle after two more hours in darkness.
The reproducibility of RAPD profiles: Effects of PCR components on RAPD analysis of four centaurium species
Authors: Skoric Marijana , Siler B. , Banjanac Tijana , Zivkovic Jasmina , Dmitrovic Slavica , Misic Danijela , Grubisic D.
Published: May 2012

Random amplified polymorphic DNA (RAPD) analysis is a simple and reliable
method used to detect DNA polymorphism. Several factors can affect the
amplification profiles, thereby causing false bands and non-reproducibility
of the assay. In this study, we analyzed the effects of different
concentrations of primer, magnesium chloride, template DNA and Taq DNA
polymerase to develop and standardize a RAPD protocol for Centaurium species.
The optimized PCR reaction mixture included: 50 ng of DNA extracted using a
CTbased protocol, 2.5 mM MgCl2, 7.5 pmol primer and 2 U of Taq polymerase
in a final volume of 25 ?l. Each of the five primers used in experiments
(OPB11, OPB15, OPB18, OPF05 and OPH02) generated reproducible and
distinguishable fingerprinting patterns of four Centaurium species. The
obtained optimized RAPD protocol and the selected primers are useful for our
further work in the genetic diversity studies of Centaurium species.
Types of beech-fir forests on Mt. Veliki Jastrebac, Serbia
Authors: Medarevic M. , Milosevic R.
Published: May 2012

The results of typological studies and typological classification of
beech-fir forests on Mt. Veliki Jastrebac, Serbia are presented. From the
typological aspect, the forests are quite homogeneous, i.e. there are two
types of forests: fir and beech (Abieti-Fagetum moesiacae montanum typicum)
on deep acid brown soils on granodiorites; and beech and fir with fescue
grass (Abieti-Fagetum moesiacae montanum drymetosum) on medium deep (often
skeletal) acid brown soils on granodiorites. By their ecology and potential
productivity, these forest types are identical with types at other localities
in Serbia, i.e. beech-fir forests in Serbia do not show the regional
character which is mostly expressed by the differences in the potential
productivity within the same type. Based on the characteristics and elements
on which the management and silvicultural measures are defined, the types
determined at this locality are two significantly different entities. This
fact requires a different approach in practical works in the selection of
silvicultural and management measures in the aim of reaching the functional
optimum, so their unification is not possible.
The effect of glycerol in the storage medium on the inhibitory kinetic behavior of glutathione reductase
Authors: Kulaksiz-Erkmen Gulnihal , Can Betul , Dalmizrak Ozlem , Ogus Hamdi , Ozer Nazmi
Published: May 2012

In this study we report on the effect of glycerol used in storage buffers, on
the inhibitory kinetic behavior of NADP+ on rat kidney glutathione reductase
(rkGR) stored at -80?C in ? 10% (v/v) glycerol. At fixed [GSSG] and varied
[NADPH], rkGR stored ? glycerol were inhibited competitively by NADP+.
Although the addition of glycerol decreased Km (9.7 ? 0.9 ?M) and Ki(NADP+)
(26.6 ? 2.2 ?M) for NADPH, the catalytic efficiency (kcat/Km = 2.75 x 107
M-1.s-1) was increased 1.64 fold. At fixed [NADPH] and varied [GSSG], rkGR
exhibited noncompetitive (Ki = 397 ? 69 ?M) and linear mixed-type (Ki = 59.6
? 8.4 ?M; Ks = 49.9 ? 3.2 ?M; ? = 7.74) inhibitions with and without glycerol
during storage. The kcat/ Km of rkGR stored in glycerol was 5.16 x 106
M-1.s-1. Although the increase in kcat was 1.25 fold, the kcat/Km was
minimally affected (1.06).
Assessment of the genotoxic potential of Lake Skadar sediments using Ames test and comet assay on the fish cell line RTL-W1
Authors: Perovic A. , Perovic Svetlana , Erdinger L. , Hollert H.
Published: May 2012

In this study we evaluated the genotoxic potential of surface sediment
extracts of Lake Skadar using a combination of two in vitro tests: the Comet
assay on the fibroblast-like permanent cell line RTL-W1, and the Ames test on
the strain Salmonella typhimurium TA98. The obtained results show that both
tests were successful in determining the genotoxic potential in the sediment
organic fractions. They possess enough sensitivity to detect early warning
signals and evaluate the genotoxic potential in sediments of the Lake. The
genotoxic potential was recorded and compared in the sediment samples from
different locations on the Lake Skadar.
Effect of exposure to sublethal concentrations of zinc cyanide on tissue ATPase activity in the fresh water fish, Cirrhinus mrigala (Ham)
Authors: Dube Shwetha , Hosetti B.B.
Published: May 2012

The present study was conducted to evaluate the effects of zinc cyanide
(Zn(CN)2) on the ATPase (Na+-K+-, Mg2+, Ca2+) activity of the freshwater fish
Cirrhinus mrigala (Ham). Fish were exposed to two sublethal concentrations
(0.114 and 0.068 mg/L) and the effects were studied in the liver, muscle and
gill tissues at the end of 5, 10 and 15 days of exposure. Cyanide
intoxication resulted in marked changes in ATPases, represented by a
significant decrease in the activities. Maximum inhibition was observed at
higher concentration. The order of inhibition in the activity was Na+-K+->
Ca2+ > Mg2+ ATPase. These results imply an immediate adaptive response to the
stress, demonstrating alterations in ATPase activities in the tissues of
cyanide-treated fish. The present study clearly proposes that ATPases can be
used as biomarkers of exposure of aquatic organisms to cyanide intoxication.
Nest-site preference of Griffon Vulture (Gyps fulvus) in Herzegovina
Authors: Marinkovic S.P. , Orlandic Ljiljana , Skoric S.B. , Karadzic B.D.
Published: May 2012

Although formerly an abundant species, the Eurasian Griffon (Gyps fulvus
Hablizl, 1783) has undergone a dramatic decline in Herzegovina. Such an
unfavorable trend may be associated with frequent poisoning incidents
(consumption of poisoned baits), shortage of food and hunting. This species
disappeared from its breeding habitats in Herzegovina during the last decade
of the 20th century. The extinction was probably caused by military
activities during the civil war. Using data that were collected over a period
of long-term (1980-1991) monitoring of the breeding population, we discovered
optimal environmental conditions for the nesting of the Eurasian Griffon
Vulture in Herzegovina. Information on nest-site preference is valuable for
conservation programs and the possible reintroduction of the Eurasian
Griffon, not only in Herzegovina, but also to a much wider region. During the
study period, we observed 61 nests and 252 nesting cases in four colonies of
Eurasian Griffon Vulture. Most nests were located on limestone and dolomite
rocks. The average altitude of nests was 378 m a.s.l.; most of nests (85%)
were located below 500 m a.s.l. Also, the majority of nests were located on
west-exposed sites.
Dental anomalies and clinical features in patients with maxillary canine impaction
Authors: Mercuri Emanuele , Cassetta Michele , Cavallini Costanza , Vicari Donatella , Leonardi Rosalia , Barbato Ersilia
Published: May 2012

Objective:

To analyze the prevalence, distribution, clinical features, and relationship with dental anomalies of maxillary canine impaction.

Materials and Methods:

The complete pretreatment records of 1674 orthodontic patients were examined. Subjects with maxillary impacted canines were divided into two study groups: a palatally displaced canine (PDC) group (114 patients) and a buccally displaced canine (BDC) group (37 patients). These were compared to a control group of 151 patients who were randomly selected from the initial sample without maxillary canine impaction. The significance of associations between canine impaction and dental and clinical features and anomalies was examined with the chi-square test.

Results:

PDC patients presented with normal overjet and facial profile and a lower degree of dental arch crowding in comparison to the control patients. PDC patients showed a higher prevalence of impaction of other teeth, dental aplasia, transposition, and peg-shaped maxillary lateral incisors (odds ratios 3.3, 2.6, 8.3, and 5.8, respectively).

Conclusion:

PDC was frequently the only orthodontic problem of patients. BDC group patients did not present with notable differences in clinical and dental features or dental anomalies compared to control subjects.
On topologies generated by some operators
Authors: Flak Katarzyna , Hejduk Jacek
Published: May 2012

The paper concerns topologies introduced in a topological space (X, τ) by operators which are much weaker than the lower density operators. Some properties of the family of sets having the Baire property and the family of meager sets with respect to such topologies are investigated.
Publication Bias
Authors: Banks George C. , Kepes Sven , Banks Karen P.
Published: May 2012

This article offers three contributions for conducting meta-analytic reviews in education research. First, we review publication bias and the challenges it presents for meta-analytic researchers. Second, we review the most recent and optimal techniques for evaluating the presence and influence of publication bias in meta-analyses. We then re-analyze two sets of meta-analytic data from the literacy literature that have been published in different journals. The analyses serve as case examples of the techniques reviewed, and the results demonstrate a range of findings from noticeable instances of publication bias to minimal or no bias. The conclusions have important implications for research, policymaking, and practice. Finally, we discuss recommendations for future research.
Sintering of mullite–β-eucryptite ceramics with very low thermal expansion
Authors: García-Moreno Olga , Fernández Adolfo , Torrecillas Ramón
Published: May 2012

Sintering of composite ceramic materials with an appropriate proportion of mullite and β-eucryptite to obtain a very low thermal expansion material has been tested by conventional and spark plasma sintering methods. The adjustment of the thermal expansion coefficient of the composites was performed by means of dilatometries and modifying the mullite–β-eucryptite proportions in the starting materials. Control of the reactivity between both phases at high temperature is the key to controlling not only the sinterability of the composites in the solid state, but also to controlling the final expansion properties of the material. X-ray diffraction with Rietveld refinement and field emission scanning microscopy have been used to characterize the sintered materials, together with some mechanical characterization.
Temperature-dependent 57Fe Mössbauer spectroscopy and local structure of mullite-type Bi2(Fe
x
Al1
–

x
)4O9 (0.1≤x≤1) solid solutions
Authors: Weber Sven-Ulf , Gesing Thorsten , Röder Jens , Litterst F. Jochen , Fischer Reinhard X. , Becker Klaus-Dieter
Published: May 2012

Oxides of the chemical composition Bi2(Fe
x
Al1
–

x
)4O9 (0.1≤x≤1) possessing a mullite-type structure have been investigated using 57Fe Mössbauer spectroscopy in the temperature range between room temperature and 1073K. The spectra have been fitted with two quadrupole doublets for Fe3
+ ions in octahedral and tetrahedral oxygen coordination. The distribution of iron on the two inequivalent structural sites has been determined from the relative areas of the subspectra. The site occupancy is found to be random within experimental error: it does not exhibit any preference of iron for the octahedral or tetrahedral sites, either as a function of temperature or with a dependence on the composition of the solid solutions.
Single crystal growth and characterization of mullite-type Bi2Mn4O10
Authors: Burianek Manfred , Krenzel Thomas F. , Schmittner Martin , Schreuer Jürgen , Fischer Reinhard X. , Mühlberg Manfred , Nénert Gwilherm , Schneider Hartmut , Gesing Thorsten M.
Published: May 2012

A part of the pseudo-binary join Bi2O3–Bi2Mn4O10 of the ternary system Bi2O3–MnO–MnO2 was examined using thermo-analytical methods. Because Bi2Mn4O10 melts incongruently single crystals of up to 20mm in diameter were grown by the top seeded solution growth method in the temperature range from about 1223K to 1173K. Single crystal neutron diffraction confirmed the principles of the crystal structure of Bi2Mn4O10 but revealed much smaller distortions of the cation coordination polyhedra. In contrast to the anisotropy observed in other mullite-type Bi containing compounds, the linear thermal expansion of Bi2Mn4O10, as studied by means of dilatometry and X-ray powder diffraction techniques, is characterized by α
11 > α
33>α
22 at room temperature. The relatively large expansion along the
a
-axis can be attributed to the two oxygen atoms bridging two corner shared MnO5 tetrahedral pyramids which alternate with the structural void between two adjacent Bi3
+ cations.
Synthesis and electrical conductivity of mullite-type Bi2Al4O9 and (Bi,Ca)2Al4O9 ceramics
Authors: Wei Wen-Cheng James , Chuang S. Y. , Hu Y. C. , Schneider Hartmut
Published: May 2012

Mullite-type Bi2Al4O9 is a potential material for electrolytes in solid oxide fuel cells. Colloidal dispersed homogeneous mixtures of commercial, submicron Bi2O3, Al2O3 and CaCO3 powders were used to fabricate mullite-type Bi2Al4O9 and (Bi,Ca)2Al4O9 by means of reaction sintering in the solid state or in liquid-phase assisted processes. The products were characterized using X-ray diffraction, scanning and transmission electron microscopy, and the sintering density was compared to two conventional sintering runs. This showed that the formation of the mullite-type Bi2Al4O9 proceeds via dissolution of Al2O3 in Bi2O3 at the temperatures > 750°C. Details on the formation mechanisms of mullite phase, electrical conductivity versus the residual γ-Bi24Al2O39 phase, and effects of Ca-dopant are reported.
An investigation of the microstructure and properties of the explosively welded Gr5–SS304 clad plates for golf heads
Authors: Zhao Hui , Zhou Yinggang , Li Pingcang , Huang Zhanghong
Published: May 2012

In this paper, Gr5 alloy and 304 stainless steel were joined by explosive welding. In order to improve the bond strength of the clad plates, a thin (2 mm) titanium sheet was introduced as an interlayer between Gr5 and SS 304. Accordingly, microstructure, hardness, tensile-shearing, and bending tests were evaluated in detail. Optical microscopy and scanning electron microscopy revealed that the interface between Gr5 alloys and the interlayer shows a slightly wavy morphology. The interface between the interlayer and SS304 shows a wavy structure. No distinctive separation, crack, or tear were observed in both interfaces. Line scan results indicate that there is no diffusion area at both bonding interfaces. Also, tensile-shearing and bending tests results showed that the bonding is acceptable.
Effect of cerium and aluminium on the hot-deformation behaviour of magnesium
Authors: Prasad Braj K. , Narayan Sashi P. , Modi Om P. , Ramakrishnan Nrarayanrao , Kumar Arun M. , Sachdev Anil K.
Published: May 2012

This study examines the response of pure Mg and its alloys, both binary Mg–Ce and ternary Mg–Al–Ce, during compression testing over a wide range of (true) strain rates and temperatures. Process maps were generated by plotting the instability parameter and efficiency of energy dissipation for microstructural evolution as a function of test temperature and strain rate. Microstructural features of each of the deformed samples were examined to generate a microstructure/micromechanism map as a matrix that was overlaid on the process map drawn in the temperature–strain-rate space. The combination of both maps delineated the desirable “safe” process window for each of the materials. Addition of 0.5% Ce to pure Mg reduced the extent of the “safe” process window despite increasing the flow stress, while alloying with both Ce and Al widened this window as determined by the extent of the desirable DRX domain. The process maps in general suggest a much wider range of temperature and strain rate for “safe” deformation compared to the microstructure maps.
Plasticity enhancement in centrally confined Zr-based bulk metallic glass
Authors: Tariq Naeem ul Haq , Awais Hasan Bin , Akhter Javaid Iqbal , Naeem Muhammad , Ahmad Atique
Published: May 2012

In the present work, a new idea is presented to enhance the plasticity of Zr65.5Cu22.4Al5.6Ni6.5 bulk metallic glass. A considerably large compressive plastic deformation (over 8%) was achieved by confining Zr65.5Cu22.4Al5.6Ni6.5 bulk metallic glass from its center. Numerical analysis was also carried out to investigate the stress distribution under the same mechanical conditions. It was revealed that loading induced high stress gradients facilitating large plastic strains through the generation of dense multiple shear bands.
Effect of titanium on the as-cast microstructure and impact toughness of hypereutectic high-chromium cast iron
Authors: Huang Zhifu , Xing Jiandong , Gao Yimin , Zhi Xiaohui
Published: May 2012

The effect of titanium on the as-cast microstructure of a hypereutectic high-chromium cast iron was investigated by means of optical microscopy, scanning electron microscopy and energy-dispersive X-ray spectroscopy. The results indicate that the primary M
7C3 carbides are refined and spheroidized with the addition of a suitable amount of titanium. TiC is found in the primary carbide by energy dispersive spectroscopy analysis. The mechanism of titanium modification on the microstructure of the alloy is also discussed. In addition, the impact test result indicates that, compared with the hypereutectic high-chromium cast iron without titanium addition, the impact toughness value of hypereutectic high-chromium cast iron with titanium additions is improved and approximately reaches 6.4 J · cm−2.
Cyclic fibre texture in hot extruded Ni50Mn29Ga21
Authors: Chulist Robert , Skrotzki Werner , Oertel Carl-Goerg , Böhm Andrea , Brokmeier Heinz-Günter , Lippmann Thomas
Published: May 2012

The cyclic texture in polycrystalline 5M Ni50Mn29Ga21 magnetic shape-memory alloy fabricated by hot extrusion was investigated with high-energy synchrotron radiation, neutron diffraction, and electron backscatter diffraction. Combination of these techniques reveals that the texture of the hot extruded sample is quite complex. It is composed of components related to the radial direction and rotated around the extrusion axis. Additionally, the dominant texture components change from the centre to the edge of the rod. The recrystallized grains contain many twins with the trace of the twin boundaries preferentially aligned along the extrusion and radial direction showing the cyclic nature of the texture and microstructure. The results are discussed with respect to deformation mode, phase transformations, starting grain structure, and texture.
Rod-like structure and microhardness during directional solidification of Sn-1wt.%Cu eutectic alloy
Authors: Hu Xiaowu , Ai Fanrong , Jiang Fugang
Published: May 2012

Sn-1wt.%Cu hypereutectic alloy was directionally solidified upward at a constant temperature gradient (G = 12 K · mm–1) in a wide range of growth velocities (V = 1–250 μm · s–1) using an improved Bridgman-type directional solidification furnace. The microstructure was observed to be a Cu6Sn5 rod in the matrix of β-Sn from the directionally solidified Sn-1wt.%Cu samples. The rod spacing (λ), rod diameter (d), and microhardness (HV) were measured from transverse sections of the samples. The experimental results showed that the rod spacing and rod diameter decreased with increasing growth velocity, while the microhardness increased with increasing growth velocity. The dependences of the rod spacing (λ), rod diameter (d), and microhardness (HV) on the growth velocity (V) were determined by using linear regression analysis, given as: λ = 10.49V−0.47, d = 2.1V−0.37 and HV = 9.33V0.11, respectively. The dependences of the microhardness on the rod spacing and rod diameter were also investigated, and the relationships between them were obtained by using linear regression analysis, given as: HV = 16.4λ−0.235 and HV = 11.8d−0.245.
Formation of Al67Cu23Fe10 quasicrystals by microwave heating
Authors: Mihoc Carmen , Schick Daniel , Lütgens Matthias , Lathe Christian , Burkel Eberhard
Published: May 2012

The present work was carried out to compare the formation of single icosahedral phase during conventional heating and microwave processing. Al67Cu23Fe10 alloy powder was synthesized from high purity (99.9%) powder elements by mechanical alloying. Differential scanning calorimetry combined with in-situ synchrotron energy dispersive X-ray diffraction was used to identify the main solid state reactions and the phase evolution of the powders. Inductive microwave processing in the magnetic field anti-node was performed to obtain the quasicrystalline phase in only a few seconds. Due to the rapid cooling of the sample it was possible to stabilize the icosahedral phase against its competing quasicrystalline approximants. Laboratory X-ray diffraction analysis was used to characterise the atomic structure of the specimen and scanning electron microscopy was used to characterise the microstructure after the microwave processing.
A comparative study of microstructure, compressive, and fracture properties of Ti3Al-based intermetallics produced via powder metallurgy, and melting and casting processes
Authors: Dimcic Biljana , Stasic Jelena , Radic Olivera , Bozic Dusan
Published: May 2012

A comparative study of the microstructure, compressive properties, and fractography of Ti3Al and Ti3Al–Nb intermetallics produced via powder metallurgy and standard vacuum melting and casting processes has been carried out. Non-porous compacts were obtained via vacuum hot pressing of powders produced by mechanical alloying. Prior to compression tests, all samples were homogenized by a solution treatment at 1050°C (α + β region), followed by water quenching. The compression tests were performed from room temperature to 500°C in vacuum at a strain rate of 2.4 × 10–3s–1. Detailed microstructural characterization was conducted using scanning electron microscopy, followed by energy dispersive X-ray spectroscopy and X-ray diffraction analysis. Values of compressive mechanical properties of compacts were higher than those of castings. Fracture topography was examined by scanning electron microscopy. A correlation between ductility and the fracture mode exists for all materials.
Nanoindentation of pseudoelastic NiTi containing Ni4Ti3 precipitates
Authors: Young Marcus L. , Frotscher Matthias , Bei Hongbin , Simon Tobias , George Easo P. , Eggeler Gunther
Published: May 2012

Depending on the processing method, pseudoelastic NiTi alloys can have small, lenticular Ni4Ti3 precipitates; however, the mechanical properties of these precipitates are not well understood. By performing nanoindentation with a spherical indenter, Ni4Ti3 precipitates within a pseudoelastic NiTi alloy were examined. Scanning electron microscopy was used to examine the indents after nanoindentation. After unloading, the hardness and remnant depth ratios of the indents in the Ni4Ti3 precipitates, the NiTi matrix, and the “average” NiTi alloy were compared. To decouple the effects of elasticity from those of pseudoelasticity, similar nanoindentation experiments were performed on an NiAl sample and compared with results from the NiTi sample.