5 research outputs found

    Bromate Removal from Water Using Doped Iron Nanoparticles on Multiwalled Carbon Nanotubes (CNTS)

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    The raw carbon nanotubes (CNTs) were prepared by the floating catalyst chemical vapor deposition method. The raw carbon nanotubes were functionalized, impregnated with iron nanoparticles, and characterized using high resolution transmission electron microscopy (HRTEM), scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), and thermogravimetric analysis (TGA). The three types of these multiwalled carbon nanotubes were applied as adsorbents for the removal of bromate from drinking water. The effects of the pH, the concentration of BrO3- anion, the adsorbent dose, the contact time, and the coanions on the adsorption process have been investigated. The results concluded that the highest adsorption capacities were 0.3460 and 0.3220 mg/g through using CNTs-Fe and raw CNTs, respectively, at the same conditions. The results showed that the CNTs-Fe gives higher adsorption capacity compared with the raw CNTs and the functionalized CNTs. The presence of nitrate (NO3-) in the solution decreases the adsorption capacity of all CNTs compared with chloride (Cl-) associated with pH adjustment caused by nitric acid or hydrochloric acid, respectively. However, the adsorption of all MWNCTs types increases as the pH of solution decreases

    Approach to the virilizing girl at puberty

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    Virilization is the medical term for describing a female who develops characteristics associated with male hormones (androgens) at any age, or when a newborn girl shows signs of prenatal male hormone exposure at birth. In girls, androgen levels are low during pregnancy and childhood. A first physiologic rise of adrenal androgens is observed at the age of 6 to 8 years and reflects functional activation of the zona reticularis of the adrenal cortex at adrenarche, manifesting clinically with first pubic and axillary hairs. Early adrenarche is known as “premature adrenarche.” It is mostly idiopathic and of uncertain pathologic relevance but requires the exclusion of other causes of androgen excess (eg, nonclassic congenital adrenal hyperplasia) that might exacerbate clinically into virilization. The second modest physiologic increase of circulating androgens occurs then during pubertal development, which reflects the activation of ovarian steroidogenesis contributing to the peripheral androgen pool. However, at puberty initiation (and beyond), ovarian steroidogenesis is normally devoted to estrogen production for the development of secondary female bodily characteristics (eg, breast development). Serum total testosterone in a young adult woman is therefore about 10- to 20-fold lower than in a young man, whereas midcycle estradiol is about 10- to 20-fold higher. But if androgen production starts too early, progresses rapidly, and in marked excess (usually more than 3 to 5 times above normal), females will manifest with signs of virilization such as masculine habitus, deepening of the voice, severe acne, excessive facial and (male typical) body hair, clitoromegaly, and increased muscle development. Several medical conditions may cause virilization in girls and women, including androgen-producing tumors of the ovaries or adrenal cortex, (non)classical congenital adrenal hyperplasia and, more rarely, other disorders (also referred to as differences) of sex development (DSD). The purpose of this article is to describe the clinical approach to the girl with virilization at puberty, focusing on diagnostic challenges. The review is written from the perspective of the case of an 11.5-year-old girl who was referred to our clinic for progressive, rapid onset clitoromegaly, and was then diagnosed with a complex genetic form of DSD that led to abnormal testosterone production from a dysgenetic gonad at onset of puberty. Her genetic workup revealed a unique translocation of an abnormal duplicated Y-chromosome to a deleted chromosome 9, including the Doublesex and Mab-3 Related Transcription factor 1 (DMRT1) gene

    Mechanistic study of polyepoxy succinic acid (PESA) as green corrosion inhibitor on carbon steel in aerated NaCl Solution

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    The inhibition mechanism of mild steel corrosion in aerated aqueous 3% NaCl medium was studied using Polyepoxy succinic acid (PESA) as a green inhibitor. The study utilized electrochemical, thermodynamic, and surface microscopic techniques. Computational methods supported the empirical results of the inhibition mechanism at the molecular level. Results showed inhibition efficiency of PESA exceeding 60% at 2 g/l at 25 °C through the formation of a protection layer on mild steel surface. An addition of 2 mg/l of zinc cations to 2 g/l of PESA at 25 °C enhanced the inhibition efficiency reaching 90%. SEM and AFM scans revealed an efficient coverage of an adsorbed layer on mild steel surface. Quantum chemical, Monte Carlo computation and simulation provided mechanistic insights of the reactivity sites and PESA's adsorption strength on metal surface

    Diagnosis and Therapy of Female Genital Malformations (Part 1). Guideline of the DGGG, OEGGG and SGGG (S2k Level, AWMF Registry Number 015/052, May 2019).

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    Objectives Female genital malformations may take the form of individual entities, they may involve neighboring organs or they may occur in the context of complex syndromes. Given the anatomical structures of the vulva, vagina, uterus and adnexa, the clinical picture of malformations may vary greatly. Depending on the extent of the malformation, organs of the urinary system or associated malformations may also be involved. Methods This S2k-guideline was developed by representative members from different medical specialties and professions as part of the guidelines program of the DGGG, SGGG and OEGGG. The recommendations and statements were developed using a structured consensus process with neutral moderation and voted on. Recommendations The guideline is the first comprehensive presentation of the symptoms, diagnosis and treatment options for female genital malformations. Additional chapters on classifications and transition were included

    Diagnosis and Therapy of Female Genital Malformations (Part 2). Guideline of the DGGG, OEGGG and SGGG (S2k Level, AWMF Registry Number 015/052, May 2019).

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    Objectives Female genital malformations may be present in the form of individual entities, they may involve neighboring organs or they may occur in the context of complex syndromes. Given the anatomical structures of the vulva, vagina, uterus and uterine appendages, the clinical picture of malformations varies greatly. Methods This S2k-guideline was developed by representative members from different medical specialties and professions as part of the guidelines program of the DGGG, SGGG and OEGGG. The recommendations and statements were developed and voted on using a structured consensus process with neutral moderation. Recommendations This guideline is the first comprehensive summary of female genital malformations from infancy to adulthood which covers clinical examinations, diagnostic workups and treatment options. Additional chapters have been included on complex urogenital malformations, vascular malformations, psychosomatic care, and tumor risk
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