OBJECTIVE:Classification of polycystic ovary syndrome (PCOS) according to their phenotypes is important in terms of understanding which parameter has clinical and laboratory implications. This study was designed to measure the follicular fluid total oxidant capacity (TOC) and total antioxidant capacity (TAC) and DNA degradation products of 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels in patients with different PCOS phenotypes undergoing In-Vitro Fertilization/Intra-Cytoplasmic Sperm Injection (IVF/ICSI).PATIENTS AND METHODS:Thirty women who were diagnosed with PCOS and twenty infertile patients who did not have the clinical and laboratory findings of PCOS were included. Women carrying at least two of the three parameters below were considered to have PCOS. (1) Biochemical or clinical manifestations of hyperandrogenism (HA); (2) Ovulatory dysfunction (OD); (3) Polycystic ovarian morphology (PCOM). Patients were then classified into four different PCOS phenotypes: (1) Phenotype A is also known as classical PCOS and meets all three criteria (HA/OD/PCOM). (2) Phenotype B has two criteria, HA and OD. (3) Phenotype C consists of HA and PCOM criteria. (4) Phenotype D is the non-hyperandrogenic form and consists of OD and PCOM criteria. Antagonist protocol was used in both PCOS and control groups. During oocyte pick-up, follicular fluid of the dominant follicle was collected. TAC and TOC levels, which are redox balance markers, and 8-OHdG levels, which are DNA degradation products, were measured in follicular fluid samples (FF).RESULTS:Follicular fluid 8-OHdG levels of all four types of phenotypes were significantly higher than the control group. When the phenotype groups were evaluated among themselves, FF-8-OHdG levels of each group were found to be similar. Serum TOC levels of each phenotype group were found to be significantly higher than the control group. TAC levels of the patients in the control group were significantly higher than the other four phenotype groups. Oxidative stress index (OSI) values were significantly higher in all four phenotype groups compared to the control group. OSI values of phenotype B and D groups were significantly higher than phenotypes A and C.CONCLUSIONS:In each phenotype of PCOS, TOC and OSI increased while TAC decreased. Increased OSI leads to DNA degradation and an increase in the level of 8-OHdG. The cumulative effect of oxidative stress and DNA degradation may be the main mechanism of PCOS-related subfertility.

Dehydration of halloysite (Hly) to metahalloysite (m-Hly) was examined by X-ray diffraction (XRD). The Hly samples heated in temperature range of 80–400 ℃. The heating time ( t ) at each temperature was changed up to 420 min. The peak intensities ( I ) for the basal spacing ( d 001 ) of Hly (1.0 nm) and m-Hly (0.7 nm) were determined. The variation of the intensities with the heating time was evaluated for each temperature. The full heating time ( t f ) for each completed crystal transformation was determined graphically and used as kinetic variable. The rate constant ( k ) was evaluated as k=1/t_f for the crystal transformation assumed from the zeroth order ( n = 0). It has been observed that the drawn ln k -1/ T graph conforms to the Arrhenius equation in the form of lnk=-3247.2/T+3.4215 . The activation energy was calculated as E # = 27 kJ mol −1 from the slope of this line equation, and the frequency factor from its intercept was calculated as A = 31 min −1 .

OBJECTIVE:To investigate the effects of body mass index (BMI) values and 25(OH) vitamin D levels determined by Endocrine Society on serum Anti Mullerian Hormone (AMH) and antral follicle count (AFC) in women with polycystic ovary syndrome (PCOS).PATIENTS AND METHODS:Sixty infertile women with PCOS and 30 age-matched women with unexplained infertility (UEI), were included. Patients in PCOS and control groups were divided into three subgroups according to their BMI values as normal, overweight and obese. Each BMI group was divided into three subgroups according to vitamin D levels. While AMH and vitamin D levels were determined at first admission, AFC was measured on the third day of cycle.RESULTS:BMI, AFC, and AMH levels of women with PCOS were significantly higher than the UEI group. AMH values of women with PCOS with normal BMI were found to be significantly higher than UEI controls with normal BMI. AMH values of overweight and obese PCOS patients and controls were similar. As BMI values of the PCOS group increased, vitamin D levels decreased significantly. Vitamin D levels of the patients in the PCOS group were found to be significantly lower than the control group. When evaluated according to BMI, the vitamin D levels of normal, overweight and obese women with PCOS were significantly lower than the UEI.CONCLUSIONS:Rising BMI in PCOS leads to a significant decrease in vitamin D and AMH. Deficiency, insufficiency or normality of vitamin D do not affect the main markers of ovarian reserve.

Using a specially constructed experimental apparatus, the freezing thermograms of benzene at increasingly higher constant pressures and temperatures were determined.The isotherm reversible freezing of liquid benzene, which metastabilizes irreversibly through super cooling and isentalpic transformation steps, is studied in detail.In addition to the temperature and pressure changes, it was determined that the step times decreased rapidly due to increasing pressure and temperature and reached zero.Where these quantities are zero, 356 K and 2230 bar are considered as the temperature and pressure of the critical point of the liquid-solid equilibrium line, respectively.The liquid-solid equilibrium line for the variation of pressure with temperature between this critical point and the triple point is precisely determined.A pressure-temperature phase diagram with the critical point and this test line is arranged for benzene.The irreversible metastabilization of liquid benzene has been studied thermodynamically.It has been determined that enthalpy, entropy, volume and internal energy changes and work done on the system decrease rapidly with temperature and pressure as they gradually increase and approach zero at critical values.

A weak acidic complex ester (CE) in solid form was prepared by a condensation reaction between very weak boric acid (BA: H3BO3) and (D)-mannitol (MA: C6H14O6) by the molar ratio of BA/MA = 2. A boron carbide (B4C) precursor was obtained from heating of the CE at 400 °C for 4 h. The precursor was pyrolyzed under argon flow in the interval of 1300–1550 °C for 4 h and at 1400 °C for 1–4 h, respectively. The materials were examined using several techniques such as X-ray diffraction analysis, thermal analysis, scanning electron microscopy, particle size distribution, and nitrogen adsorption/desorption. The optimum pyrolysis temperature and duration were 1400 °C and 4 h, respectively. The most crystalline B4C particles were distributed between 1 and 100 µm with a mean particle size of 20 µm. The specific surface area and specific pore volume were 13.5 m2 g–1 and 0.09 cm3 g–1, respectively. The size of the pores was between 2 and 36 nm with a mean size of 14 nm.

Among green synthesis methods, which are an eco-friendly, non-toxic, simple, and safe approach for the synthesis of silver nanoparticles (AgNPs), using plant extract is the most efficient method. Salvia fruticosa Mill. which was not used formerly was selected for this research. By changing the synthesis parameters (the amount of extract, extract concentration, and silver ion concentration in precursors), their effects on the formation and structure of nanoparticles were investigated by UV-visible spectroscopy, transmission electron microscopy and Fourier transform infrared spectroscopy techniques. The antioxidant activity of extracts and AgNPs was evaluated by performing DPPH assay. It is observed that the phytosynthesized nanoparticles also possess antioxidant potentials. Finally, AgNPs were used as modifiers for carbon paste electrode (CPE) and their effect on charge transfer resistance and the ascorbic acid signal was investigated by using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and square wave voltammetry (SWV). E1-1/CPE showed good electro-catalytic oxidation of ascorbic acid and can be utilized for the development of the new sensors. According to results, in the process of green synthesis of AgNPs, synthesis parameters are vital as they change not only the size and size distribution of the AgNPs but also their antioxidant activity and electrochemical properties.

The aim of this study was to investigate the interaction of carbide nuclear fuels with steel that is being used as cladding material for nuclear reactors. The specimens prepared from steel EN 1.4988 were consecutively annealed in three uranium carbide (UC) powders, having different carbon contents, at 600 °C for 1000 h. Both Ar and Na were used as bonding elements. The increase in the carbon content of the carburized specimens was determined and evaluated according to the bound and free carbon contents in the UC powders. The migration of free and bound carbon atoms into steel via self-diffusion and over Fe3C formation is interpreted as carburizing. Microhardness measurements and stress-strain tests were used to determine the mechanical properties of crude and carburized steel specimens. Maximum hardness at the contact surface and depth of the carburized zone were determined from the microhardness profiles and discussed depending on the bonding elements and carbon content in the specimens. These variables have a significant impact on the elongation percent, 0.2% yield stress, and tensile stress.

Molecular modelling is an appreciated tool that brings valuable data on physical and chemical characteristics of materials that eliminates the necessity of conducting any experiment. This method allows to calculate the performance of energetic molecules to be synthesized. In the work, the detonation parameters of the energetic organic compounds Pentaerythritol tetranitrate(PETN), Butanetriol trinitrate (BTTN), Trimetylolethane trinitrate (TMETN) and Diethyleneglycol dinitrate (DEGDN) has theoretically been calculated and some values compared with the literature values. Moreover, three hypothetical molecules combining PETN with other explosive molecules have been designed. The detonation properties have been calculated using density functional theory (DFT) with B3LYP/6-31G (d,p) basis set. It has been concluded that all molecules have the effect of increasing the explosion parameters of PETN.

This study presents the preparation and application of the electrochemical sensor based on pencil graphite elec-trode (PGE) coated with a mixture of multi-wall carbon nanotube (MWCNT) and nano size-sodium montmoril-lonite (NNaM). The electrode obtained was used in the electrochemical quantification of heavy metals. The electrochemical analysis was elaborated further by collecting Bi nanoparticles (BiNP) on the electrode surface during the deposition step of the analytes. The heavy metal cations, zinc (II), cadmium (II), lead (II) and copper (II) were qualified at the potentials of about -1.0, -0.70, -0.47 and 0.00 V, respectively and they quantified within the linear concentration ranges of 2.36-40.0; 40.0-180.0 mu M, 0.32-2.0; 2.0-240.0 mu M, 0.03-5.0; 5.0-80.0 mu M and 0.52-10.0; 10.0-40.0 mu M, respectively. The characterization of the electrode surfaces was made by energy-dispersive X-ray spectroscopy (EDS), electrochemical impedance spectroscopy (EIS), and cyc-lic voltammetry (CV). The surface morphology of the electrode was investigated by scanning electron micro-scopy (SEM). The electrode developed was coded by BiNP/MWCNT-NNaM/PGE. The electrochemical quantification results indicate that the electrode developed is a low-cost tool of high conductive surface area, capable of producing a high SWAS voltammetric signal; much better for electrochemical analysis than unmod-ified PGE. Repeatability and reproducibility for BiNP/MWCNT-NNaM/PGE electrode were found to be RSD < 9.5 % and RSD < 8.0 %, respectively. The interference effects of the cations Mn2+, Al3+, Ni2+, Sb3+ Co2+, Fe3+, Cr3+, Ca2+, Mg2+ and Na3PO4 at concentrations ten-fold lower than the analytes are toler-able (< 4.5 %). Detection limits as low as 0.707 mu M, 0.097 mu M, 0.008 mu M, and 0.157 mu M, were formed for Zn (II), Cd (II), Pb (II), and Cu (II), respectively. The designed sensor was applied to a tap water sample using the standard addition method, and the results are satisfactory.

We report the simultaneous determination of purine molecules with biological significance on pencil graphite electrode (PGE) modified with a composite solution including NiO nanoparticles, multi-walled carbon nanotube (MWCNT), and natural nano-Na-montmorillonite clay (NNaM) using DPV technique. The novel sensor, NiO/MWCNT/NNaM/PGE, achieved simultaneous determination of xanthine, theophylline, and theobromine at the detection limits 0.077 mu M, 0.361 mu M, and 0.458 mu M with the linear working ranges 0.5-150 mu M, 5-200 mu M, and 5-250 mu M in Britton-Robinson buffer at pH 2.0, respectively. The sensor revealed excellent performance for the simultaneous determination of XT, TP, and TB in three real-world samples.

Three samples taken from a silica gel Hypersil were hydrothermally treated, washed and dried under different conditions. The portions from the obtained samples were heated over a temperature range of 300 and 850 °C for 16 h. Surface area and pore volume all of the treated samples were respectively determined by nitrogen adsorption data at 77 K and mercury porosimetry. The volumetric flow rate and permeability of the isopropyl alcohol on the columns filled with the prepared samples were determined depending both the inlet pressure and packing pressure. The optimum conditions to prepare a column filling materials with the heights permeability were discussed.

Using experimental data from literature [1], hydrogen density-pressure (ρ-P) and density-temperature (ρ-T) phase diagrams were drawn and evaluated for various pressure and temperature intervals. Solid, liquid, vapor, gas, supercritical liquid, supercritical gas and supercritical fluid regions were identified on the obtained diagrams. There are exact equilibrium boundaries between subcritical phases. On the contrary, it is concluded that there are no such exact boundaries for supercritical phases. Formation of the supercritical fluid between liquid and gas phases explained thermodynamically with first and second order partial derivatives of chemical potential relative to pressure at constant temperature.

Surface area (20 m(2)g(-1)) and pore volume (0.015 cm(3)g(-1)) estimate for the bottom ash of an asphaltite from Sirnak/Turkey deposit, were determined using the nitrogen adsorption/desorption isotherms at 196 degrees C. The shape and location of the adsorption/desorption isotherms of ammonia on the ash at 0, 50, 100, and 200 degrees C revealed that the irreversible chemical adsorption was more effective than the accompanied physical one. The overall and chemical adsorption capacities increased with the increasing temperature, whereas the physical adsorption capacity decreased. Data obtained from the isotherms, adsorption isosteres, and corresponding Van't Hoff graphs were evaluated thermodynamically to estimate the isosteric enthalpy (Delta H) and entropy changes (Delta S) for the overall ammonia adsorption. Decrease in Delta H and Delta S is caused due to a drop in the endothermic chemical adsorption, whereas increasing exothermic physical adsorption is correlated to the progression of the reaction.

When looking at the experimental research on boron complex condensation reactions, it appears that polyvinyl alcohol or mannitol is often used with boric acid (H3BO3). Contrary to the common literature use, monoethylene glycol (C2H6O2) and glycerol (C3H8O3) molecules were studied in this study. It is intended to choose the ideal molecule to synthesis the boron complex using the data obtained from the theoretical analysis of molecules, In addition, it was aimed to conduct an experimental study considering the 1:1 molar ratio between boric acid and the other two molecules in order to make an experimental contribution to the theoretical results. Spartan 14 and Gaussian 03W package programs were used in theoretical studies. As methods, the B3LYP mixed density function theory and the 6-31+G ** diffuse bipolar split valence base set were chosen. Investigation on the molecules, some structure descriptors such as total molecular energy (ET), E HOMO, E LUMO, electron affinity (A), ionization energy (I), hardness (ɳ), softness (σ), electronegativity (χ), chemical potential (CP) and electrophilicity (ω) have been calculated. According to the results obtained from the theoretical studies,in the complex ester formation reaction, the glycerol molecule contains more hydroxyl groups (three hydroxyl groups), the energy gap (8.51) is lower, the softer (0.23502) molecule and it is more electronegative (2.775) in its structure than the monoethylene glycol molecule, was predicted to be more effective. Experiments were carried out at a pressure of 1 atm, at a temperature of 100 °C, and with a Graham condenser. Since the products were not intended for use in a structure, no characterization tests were conducted on them, but pH changes over time were observed and reported. The obtained pH values revealed that the boric acid-glycerol solution was more acidic.

A gray-colored sediment from Erzurum/Turkey zone was characterized by scanning electron microscopy, X-ray diffraction, chemical analysis, and thermal analysis techniques. The raw sample contains mainly an amorphous biogenic opal-A as well as opal-CT, smectite, illite, and quartz as impurities. The XRD-pattern of the heated samples at different temperatures ranging between 1050 and 1175oC for durations from zero to 4 h was recorded. Consecutive increases in the intensity of the characteristic XRD-reflection at 2θ = 22o showed that the biogenic silica changed over paracrystalline opal-CT to crystalline α-cristobalite having the reflection with the maximum intensity (Im). Its insolubility in orthophosphoric acid digestion proved this formation. The temperature and heating time dependent intensity (I) were used as kinetic variables and the ratio of $$ I/{I}_m=\alpha $$ was defined as crystalline fraction. Using the differential rate law, $$d\alpha /dt=k {(1-\alpha )}^{n}$$ and Arrhenius equation $$\text{ln}k=-{E}^{\#}/RT+ln A$$ , the order and activation energy for the crystallization were calculated as $$n=1$$ , and $${E}^{\#}=202 \text{k}\text{J}{ \text{m}\text{o}\text{l}}^{-1},$$ respectively.

Pentaerythritol tetranitrate (PETN, C5H8N4O12) is a relatively stable explosive nitrate ester molecule. It has been widely used in various military and public industrial productions. In this study, the solubility tendency of PETN in different organic solvents was investigated theoretically. Several physicochemical parameters of PETN such as density, detonation pressure, temperature, rate and products of detonation reaction were investigated using the B3LYP functional and basic set of polarization functions (d, p) containing 6-31G**. The obtained results have been compared with the literature values. Furthermore, the stability and reactivity of PETN in acetone, diethyl ether, ethanol, tetrahydrofuran, toluene and methylene chloride were examined. Results revealed toluene is a good solvent to increase the explosive properties of PETN.

Abstract Acid activation was carried out by heating muds prepared from Ca-rich bentonite (CaB), sulfuric acid (H2SO4) and distilled water, yielding various bleaching earths (BEs). The roles of each of the process variables, namely mass fraction of H2SO4 (x) in the dried CaB and pure H2SO4 mixture, heating temperature (T) and contact time (t), in the activation were tested. The raw CaB and each BE were examined with X-ray diffraction, chemical analyses, N2 adsorption/desorption, pH-metry and tintometry. The BE contents in both the aqueous and oily suspensions were set to 2% by mass in order to measure the pH value and the bleaching power, respectively. The optimum conditions for the activation to obtain a BE having the same bleaching power (0.60) as Tonsil® Optimum Bleaching Earth for soybean oil were determined as x = 0.35, T = 100°C and t = 2 h. The bleaching power increased only marginally upon increasing the activation time from 2 h up to 10 h at a given x and T. After 10 h, significant changes did not take place in the bleaching power of the BE. The mass fraction of total structural metal oxide (y), pH value, specific pore volume (V), specific surface area (S) and mean internal diameter (D) of the mesopores for the optimized BE are y = 0.10, pH = 3.0, V = 0.31 cm3 g–1, S = 225 m2 g–1 and D = 7 nm. The pH and D values were more important for bleaching the alkaline refined soybean oil compared to the other parameters tested.

Two methods were proposed to calculate the thermodynamic parameters of porous ceramic compacts depending on their molar volume change with applied pressure and heating temperature, respectively. Molar volume of the porous α-alumina (α-Al2O3) compact was evaluated according to literature depending on both the applied pressure at room temperature and the heating temperature at atmospheric pressure. The isothermal compressibility coefficient, Gibbs energy, and work done on the compact by compression were calculated. The thermal shrinkage coefficient and activation energy as well as the change in enthalpy, entropy and Gibbs energy were calculated for partial sintering. The spontaneous nature of the treatments were discussed with respect to the obtained results.

Since their exceptional rheological behavior, bentonite suspensions are widely used in engineering, industrial, agricultural, and drilling applications. So, the aim of the present study is to investigate the rheological properties of three types aqueous suspensions prepared with calcium bentonite (CaB), sodium bentonite (NaB) obtained from that by Na2CO3 activation, and NaB with the excess soda. The CaB taken from Giresun/Turkey region contains calcium smectite (CaxS) as clay mineral and opal CT (SiO2.nH2O) as impurity which is paracrystalline silica. Soda content by the activation and bentonite content in the suspension were changed in the interval of 2.5-15.0% and 5-20% by mass, respectively. CaxS completely converted to sodium smectite (Na2xS) by the activation with the soda content of 2.5% and then Na2xS+Na2CO3 mixtures formed. Rheological properties of these aqueous suspensions were measured using a Fann Viscometer. These properties reached their maxima by the most thixotropic Na2xS suspensions and greatly increased with the increasing of smectite content. Rheological plots drawn of the shear rate vs. shear stress in the interval of 170-1020 s-1 showed that the suspensions flow as a Bingham Plastic. Change in rheological properties depending on the smectite type and content as well as excess soda content was explained thermodynamically based on the chemical potential gradient between interlayer and dispenser waters.

AbstractThe objective of this work was to use air-dried sepiolite granules as an additive in cigarette filter tips to increase the removal yield of tar and nicotine from mainstream smoke. Granules with a mass of 95 mg per cigarette filter and a mean particle size (D) of 0.05–0.41 mm were used to constrain the effects of the mean particle size and mass of sepiolite in the removal process. The granules were sandwiched in common cellulose acetate filter tips. Maximum removal yields of 90% were obtained when D ≤ 0.10 mm. Filters containing granules with a mean size of 0.10 mm and mass variations from 35 to 95 mg were tested, and increasing amounts of sepiolite added led to progressively greater yields of tar and nicotine from 20% to 90%. The sepiolite granules were examined using scanning electron microscopy with energy-dispersive X-ray spectroscopy, Fourier-transform infrared spectroscopy and X-ray diffraction techniques both before and after smoke experimentation. It is suggested that tar and nicotine were condensed both on the fibre clusters of the sepiolite granules and in the voids between them during the flow of the mainstream smoke.