Leydig cell tumors (LCTs) refer to tumors of the stroma of the genital strand, which are found mainly in postmenopausal women. The diagnosis of LCTs in postmenopausal women is associated with ...specific difficulties and is based on the identification of hyperandrogenism with clinical manifestations of virilization, which has an erased picture in postmenopausal women. LCTs require differential diagnosis with other causes of hyperandrogenism. We present the clinical case of a 55-year-old Russian postmenopausal patient with LCTs of the right ovary, significantly increased levels of androgens, and rapidly progressive clinical signs of hyperandrogenism. The patient underwent laparoscopic bilateral salpingo-oophorectomy, and the androgen indices reached average values by the first and third month after surgery. This case demonstrates that LCTs are often benign with a good prognosis and normalization of the clinical and laboratory manifestations of hyperandrogenism after surgical treatment. The type of surgery performed (bilateral salpingo-oophorectomy rather than unilateral) is recommended as the treatment of choice for LCTs in postmenopausal patients.
We examined the effect of hydrogen on the growth of single-walled carbon nanotubes in the aerosol (a specific case of the floating catalyst) chemical vapor deposition process using ethylene as a ...carbon source and ferrocene as a precursor for a Fe-based catalyst. With a comprehensive set of physical methods (UV-vis-NIR and Raman spectroscopies, transmission electron microscopy, scanning electron microscopy, differential mobility analysis, and four-probe sheet resistance measurements), we showed hydrogen to inhibit ethylene pyrolysis extending the window of synthesis parameters. Moreover, the detailed study at different temperatures allowed us to distinguish three different regimes for the hydrogen effect: pyrolysis suppression at low concentrations (I) followed by surface cleaning/activation promotion (II), and surface blockage/nanotube etching (III) at the highest concentrations. We believe that such a detailed study will help to reveal the complex role of hydrogen and contribute toward the synthesis of single-walled carbon nanotubes with detailed characteristics.
In the framework of method of the B3LYP hybrid density functional and the restricted Hartree-Fock method, quantum-chemical calculations of model compounds of lignin, i.e. derivatives of ...p-hydroxycinnamic alcohol were carried out. The structures and reactivity of coumaric, coniferyl and synapol alcohols were studied. Quantitative characteristics of the reactivity of these acids are given. It is found that the electronic structure of lignin is determined primarily by the charge distribution in its structural phenylpropane unit. In the molecules of all model compounds of lignin, the center for nucleophilic attack is the carbon of aromatic ring (E-ring) with a hydroxyl group, and in the molecule of synapol alcohol, this center is also the carbon of the aromatic ring (E-ring) with a methoxy group. In all three compounds, a center with an increased electron density appears on the Сβ carbon atom.
BACKGROUND Although ovarian reserve tests (ORTs) are frequently used prior to IVF treatment for outcome prediction, their added predictive value is unclear. We assessed the added value of ORTs to ...patient characteristics in the prediction of IVF outcome. METHODS An individual patient data (IPD) meta-analysis from published studies was performed. Studies on FSH, anti-Müllerian hormone (AMH) or antral follicle count (AFC) in women undergoing IVF were identified and authors were contacted. Using random intercept logistic regression models, we estimated the added predictive value of ORTs for poor response and ongoing pregnancy after IVF, relative to patient characteristics. RESULTS We were able to collect 28 study databases, comprising 5705 women undergoing IVF. The area under the receiver-operating characteristic curve (AUC) for female age in predicting poor response was 0.61. AFC and AMH each significantly improved the model fit (P-value <0.001). Moreover, almost a similar accuracy was reached using AMH or AFC alone (AUC 0.78 and 0.76, respectively). Combining the two tests, however, did not improve prediction (AUC 0.80, P = 0.19) of poor response. In predicting ongoing pregnancy after IVF, age was the best single predictor (AUC 0.57), and none of the ORTs added any value. CONCLUSIONS This IPD meta-analysis demonstrates that AFC and AMH clearly add to age in predicting poor response. As single tests, AFC and AMH both fully cover the prediction of poor ovarian response. In contrast, none of the ORTs add any information to the limited capacity of female age to predict ongoing pregnancy after IVF. The clinical usefulness of ORTs prior to IVF will be limited to the prediction of ovarian response.
We developed a novel robust technique to produce high-quality dispersions of debundled SWCNTs in aqueous solutions. Direct injection of SWCNTs treated with supercritical nitrogen into the aqueous ...surfactant solution facilitates the dispersion process without the need of extensive ultrasonication. According to photoluminescence and absorbance measurements, the mild ultrasonic treatment of such dispersions resulted in a higher yield of individual SWCNTs, compared to pristine tubes and tubes collected after the supercritical treatment in the form of powder.
ABSTRACT In this research note, we replicate Brazel, Jackson, Schaefer, and Stewart's (2016) study of how auditors evaluate skeptical behavior. Like the original study, we find that evaluators reward ...audit staff who exercise appropriate levels of skepticism and identify a misstatement (positive outcome). However, when no misstatement is identified (negative outcome), evaluators penalize staff who exercise appropriate levels of skepticism. One factor causing this outcome effect may be that exercising skepticism typically causes budget overages due to additional testing. Hence, we examine whether formally attributing the budget overage to skeptical judgments and actions in the audit budget file reduces outcome effects. However, while replicating the initial effect across three separate studies, we have been unable to reduce this effect. Thus, it is clear that the outcome effect in this context is very robust. Data Availability: Contact the authors.
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•Structures of two related bacterial O-antigen pairs were elucidated.•O-Antigens of C. sakazakii G2594 and E. coli O103 differ in the glucosylation pattern.•O-Antigens of C. ...malonaticus G3864 and E. coli O29 differ in the O-acetylation pattern.•O-Antigen gene clusters are identical within each bacterial pair.•The structural differences are suggested to be due to prophage-carried genes.
O-Antigen (O-polysaccharide) variation is the basis for bacterial serotyping and is important in bacterial virulence and niche adaptation. In this work, we present structural and genetic evidences for close relationships between the O-antigens of the Cronobacter spp. and Escherichia coli. Cronobacter sakazakii G2594 (serotype O4) and Cronobacter malonaticus G3864 (serotype O1) are structurally related to those of E. coli O103 and O29, respectively, and some other members of the Enterobacteriaceae family differing in the patterns of lateral glucosylation (C. sakazakii G2594) or O-acetylation (C. malonaticus G3864). The O-antigen gene clusters of the corresponding Cronobacter and E. coli strains contain the same genes with high-level similarity, and the structural differences within both O-antigen pairs were suggested to be due to modification genes carried by prophages.
The relevance of the study is caused by the need to use both non-renewable and renewable natural resources to meet the energy needs. The purpose: the use of renewable raw materials with similar ...technological characteristics (starch, guar gum and neutral lignosulfonate) to create new reagent systems LKR-1 and LGKR-1 for application in oilfield chemistry, in particular as part of drilling fluids for use in the construction of oil and gas wells. Methods: set of existing basic methods for studying the properties of raw materials and synthesis products of natural polymers; evaluation and analysis of consistency index and nonlinearity coefficient (Brookfield viscometer), rheological (Fann rotary viscometer) and filtration properties (Fann filter press) of the developed reagent systems and known brands of gums. Results. It is shown that for Russia the issue of the competent use of renewable raw materials products is relevant, since it is a world leader in the possession of forest reserves and timber. The structure of wood as a polymer composition and the main components of both deciduous and coniferous species – cellulose, camels, starch, lignosulfonates – are presented. The paper introduces the list of domestic and foreign scientists whose works are devoted to the research and application of natural polymers in oilfield chemistry, products of renewable natural raw materials. The authors considered the influence of the main natural polymers used in oilfield chemistry and their modified forms on the technological parameters of process fluids. The properties of the developed reagent systems and their components are considered, and the presence of pseudoplastic properties of the LCR-1 reagent system is established, despite the fact that its components – starch and lignosulfonate – do not possess these properties. It was found that the component of the LGCR-1 reagent system, guar gum of plant origin, gives the developed reagent pseudoplastic properties comparable to the properties of reagents based on more expensive xanthan gum of the enzymatic production method.
We propose a novel approach to disperse and extract small-diameter single-walled carbon nanotubes (SWCNTs) using an aqueous solution of riboflavin and Sephacryl gel. The extraction of small-diameter ...semiconducting SWCNTs was observed, regardless of the initial diameter distribution of the SWCNTs. Dispersion of SWCNTs occurs due to the adsorption of π-conjugated isoalloxazine moieties on the surface of small-diameter nanotubes and interactions between hydroxy groups of ribityl chains with water. During the SWCNT extraction, specific adsorption of riboflavin to SWCNTs leads to the minimization of interactions between the SWCNTs and gel media. Our experimental findings are supported by ab initio calculations demonstrating the impact of the riboflavin wrapping pattern around the SWCNTs on their interaction with the allyl dextran gel.
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