Efficient extraction and determination of Au(III) ions from acid mine drainage and water samples using silica gel immobilized with .

The analysis of gold, which is a precious metal with limited resources, in environmental samples is crucial for the sustainable utilization of natural resources. Therefore, in the present research we have aimed to develop a novel and environmentally friendly bioadsorbent, loaded on silica gel (BB@Si), with outstanding adsorptive properties that can be implemented for quantitative recovery of Au(III) ions the solid phase extraction (SPE) technique. After characterizing the developed adsorbent using FTIR and SEM techniques, we conducted a detailed investigation of the critical parameters that influence the extraction performance of Au(III) ions.

Hyperandrogenemia impairs endometrial vitamin D receptor expression in polycystic ovary syndrome.

Objectives: To determine the effects of hyperandrogenemia and other phenotypic parameters on endometrial vitamin D receptor (VDR-X2 and VDR-X4) expression in women with polycystic ovary syndrome (PCOS) undergoing ovarian stimulation and total embryo freezing.

Methods: Forty-four PCOS patients were divided into four phenotypes according to the criteria for hyperandrogenemia (HA), ovulatory dysfunction (OD), and polycystic ovary morphology (PCOM): phenotype A (HA+OD+PCOM), phenotype B (HA+OD), phenotype C (HA+PCOM), and phenotype D (OD+PCOM). Endometrial VDR expression was determined by real-time PCR and immunohistochemistry.

Divergent Oxidation Reactions of E- and Z-Allylic Primary Alcohols by an Unspecific Peroxygenase.

Unspecific peroxygenases (UPOs) catalyze the selective oxygenation of organic substrates using only hydrogen peroxide as the external oxidant. The PaDa-I variant of the UPO from Agrocybe aegerita catalyses the oxidation of Z- and E-allylic alcohols with complementary selectivity, giving epoxide and carboxylic acid/aldehyde products respectively. Both reactions can be performed on preparative scale with isolated yields up to 80 %, and the epoxidations proceed with excellent enantioselectivity (>99 % ee).

Technique and Long-Term Results of Laparoscopic Aorto-Bi-Femoral Bypass for Juxta-Renal Aortic Occlusion.

Background: Describe the technique and the long-term results of total laparoscopic aorto-bifemoral bypass for juxtarenal aortic occlusion (JRAO).

Methods: From December 2000 to January 2023, 16 patients with a JRAO (TASC D lesions) underwent total laparoscopic aorto-bifemoral bypass. The patients' database was prospective and the file analysis was retrospective.

Altering Active-Site Loop Dynamics Enhances Standalone Activity of the Tryptophan Synthase Alpha Subunit.

The α-subunit (TrpA) of the allosterically regulated bifunctional tryptophan synthase αββα enzyme catalyzes the retro-aldol cleavage of indole-glycerol phosphate (IGP) to d-glyceraldehyde 3-phosphate (G3P) and indole. The activity of the enzyme is highly dependent on the β-subunit (TrpB), which allosterically regulates and activates TrpA for enhanced function. This contrasts with the homologous BX1 enzyme from that can catalyze the same reaction as TrpA without requiring the presence of any additional binding partner.