Fluid inclusion, zircon U-Pb geochronology, and O-S isotopic constraints on the origin and evolution of ore-forming fluids of the tashvir and varmazyar epithermal base metal deposits, NW Iran

Tashvir and Varmazyar deposits are part of the epithermal ore system in the Tarom–Hashtjin Metallogenic Belt (THMB), NW Iran. In both deposits, epithermal veins are hosted by Eocene volcanic-volcaniclastic rocks of the Karaj Formation and are spatially associated with late Eocene granitoid intrusions. The ore assemblages consist of pyrite, chalcopyrite, chalcocite, galena, and sphalerite (Fe-poor), with lesser amounts of bornite and minor psilomelane and pyrolusite. Fluid inclusion measurements from the Tashvir and Varmazyar revealed 182–287 and 194–285°C formation temperatures and 2.7–7.9 and 2.6–6.4 wt.% NaCl equivalent salinities, respectively. The oxygen isotope data suggested that the mineralizing fluids originated dominantly from a magmatic fluid that mixed with meteoric waters. The sulfur isotope data indicated that the metal and sulfur sources were largely a mixture of magma and surrounding sedimentary rocks. LA-ICP–MS zircon U–Pb dating of the granitoid intrusion at Tashvir and Varmazyar, yielded a weighted mean age of 38.34–38.31 and 40.85 Ma, respectively, indicating that epithermal mineralization developed between 40.85 and 38.31 Ma. Our data indicated that fluid mixing along with some fluid boiling were the main drives for hydrothermal alteration and mineralization at Tashvir and Varmazyar. All these characteristics suggested an intermediate-sulfidation epithermal style of mineralization. The THMB is proposed to be prospective for precious and base metal epithermal mineralization. Considering the extensional tectonic setting, and lack of advanced argillic lithocaps and hypersaline fluid inclusions, the THMB possibly has less potential for economically important porphyry mineralization

Engineered receptors for human cytomegalovirus that are orthogonal to normal human biology.

A trimeric glycoprotein complex on the surface of human cytomegalovirus (HCMV) binds to platelet-derived growth factor (PDGF) receptor α (PDGFRα) to mediate host cell recognition and fusion of the viral and cellular membranes. Soluble PDGFRα potently neutralizes HCMV in tissue culture, and its potential use as an antiviral therapeutic has the benefit that any escape mutants will likely be attenuated. However, PDGFRα binds multiple PDGF ligands in the human body as part of developmental programs in embryogenesis and continuing through adulthood. Any therapies with soluble receptor therefore come with serious efficacy and safety concerns, especially for the treatment of congenital HCMV. Soluble virus receptors that are orthogonal to human biology might resolve these concerns. This engineering problem is solved by deep mutational scanning on the D2-D3 domains of PDGFRα to identify variants that maintain interactions with the HCMV glycoprotein trimer in the presence of competing PDGF ligands. Competition by PDGFs is conformation-dependent, whereas HCMV trimer binding is independent of proper D2-D3 conformation, and many mutations at the receptor-PDGF interface are suitable for functionally separating trimer from PDGF interactions. Purified soluble PDGFRα carrying a targeted mutation succeeded in displaying wild type affinity for HCMV trimer with a simultaneous loss of PDGF binding, and neutralizes trimer-only and trimer/pentamer-expressing HCMV strains infecting fibroblasts or epithelial cells. Overall, this work makes important progress in the realization of soluble HCMV receptors for clinical application

Religious Fasting of Muslim Patients After Metabolic and Bariatric Surgery: a Modified Delphi Consensus

Background Fasting during Ramadan is one of the five pillars of the Muslim faith. Despite the positive effects of fasting on health, there are no guidelines or clear recommendations regarding fasting after metabolic/bariatric surgery (MBS). The current study reports the result of a modified Delphi consensus among expert metabolic/bariatric surgeons with experience in managing patients who fast after MBS