Healthcare systems are increasingly recognized as significant contributors to environmental burdens; however, conventional lifecycle assessment (LCA) primarily quantifies impacts and offers limited insight into the complex interactions influencing sustainability-related decisions. This study presents a scenario-based LCA of peritoneal dialysis (PD) delivery systems and explores the integration of LCA with dynamically calibrated Fuzzy Cognitive Mapping (FCM) as a systems-oriented framework. The framework is applied to PD delivery systems in Vancouver, Canada, comparing automated peritoneal dialysis (APD) and continuous ambulatory peritoneal dialysis (CAPD). Environmental impacts are assessed using the ReCiPe 2016 midpoint method across full lifecycle stages, including consumables production, transportation, and waste treatment. Multiple scenarios are developed to capture variations in clinical prescription, consumables manufacturing, transportation logistics, and service delivery pathways. Results indicate that APD with standard prescription exhibits the highest total climate change impact (35%), followed by APD incremental (25%), CAPD standard (22%), and CAPD incremental (16%). Across all scenarios, consumables production (>51%) and transportation (>42%) are the dominant contributions, highlighting upstream supply-chain processes as key intervention points. The exploratory calibrated FCM analysis identifies consumables material composition and landfill disposal as influential system components. It ranks CAPD incremental with fully virtual follow-up visits as environmentally favorable pathways under the evaluated system conditions, where clinically appropriate. These findings show that scenario-based LCA can identify clear environmental hotspots, while calibrated FCM provides an exploratory systems perspective for interpreting environmental interactions, identifying influential system components, and exploring potential mitigation opportunities within the PD system.
The Liba Au deposit (109.8 t Au at 1.99 g/t) in the West Qinling orogen (central China) is hosted in Middle Devonian greenschist facies metamorphosed clastic rocks and carbonates and has a close spatio-temporal relationship with Late Triassic granitoid complex and mafic to felsic dikes. The Au mineralization is localized within west-northwest to east-west fracture zones and characterized by pyrite disseminations and subordinate auriferous quartz veins. Based on field and textural relationships, the following four paragenetic stages are defined: (1) pre-ore stage marked by deformed pyrite, (2) early ore stage comprising quartz-pyrite and quartz-sericite-pyrite ores, (3) late ore stage composed of quartz-polymetallic sulfide veins, and (4) post-ore stage of barren calcite. Pre-ore stage pyrite (Au <= 3.0 ppm) has 834S values of 5.0 to 6.8%c, which are lower than those for ore-stage pyrites (6.8-10.4%c). This S isotope difference discounts the possibility that some of the ore-forming S was sourced from the local metasedimentary host rocks. Pyrite from the early ore stage displays core-mantle-rim zoned textures and hosts fine-grained native gold grains and has relatively high contents of invisible Au (<= 600 ppm) in its mantle zones. The uniform 834S values (mostly 8.5-10.4%c) and 206Pb/204Pb ratios (18.3918-18.6362) for these pyrites suggest a deep-seated homogenized source for ore fluids, most likely derived from metamorphic devolatilization of Paleozoic metasedimentary rocks. Pyrite of the late ore stage, closely associated with abundant native gold, can be subdivided into a texturally early Au-bearing generation (Au <= 8.9 ppm; 834S of 8.6-9.3%c; 206Pb/204Pb of 18.9885-18.9959), which is overprinted by a texturally later Au-poor generation (Au <= 2.0 ppm; 834S of 8.8-9.6%c) and Au-bearing generation (Au <= 3.9 ppm; 834S of 6.8-8.5%c; 206Pb/204Pb of 18.9501-18.9890). The lower 834S values and more radiogenic Pb isotope signature, combined with enrichment in Cu, Zn, Ag, Sn, Sb, and Pb in this latest Au-bearing pyrite, indicate a different fluid source, which is suggested to originate from magmatic-hydrothermal fluids that interacted with the enveloping Devonian metasedimentary rocks. Integration of our new data with previous studies suggests the Liba Au deposit is hybrid in nature and involved multiple fluid sources and multiple Au deposition stages-a finding that has also been documented in other orogenic Au deposit settings worldwide. In addition, systematic in situ chemical and isotopic analyses of texturally well-constrained pyrite provide the means to geochemically characterize the entire fluid evolution history, as done at Liba, and fingerprint the fluid reservoirs and processes implicated in orogenic Au systems.
The Ormaque gold deposit is located within the Val-d'Or mining district of the Archean Abitibi greenstone belt, Quebec, where the influential fault-valve model for the formation of orogenic gold deposits was first applied. The deposit is hosted within the synvolcanic C porphyry, which was emplaced in volcaniclastic rocks of the ca. 2704 Ma Val-d'Or Formation. Ormaque consists of gently dipping, extensional quartz-tourmaline-carbonate veins flanking reverse faults. The veins are surrounded by alteration halos, which contain tourmaline, carbonate, and pyrite; these are locally overprinted by late albite and pyrite. Native gold and Au-Ag-Te-Bi-bearing poly-metallic minerals occur as inclusions and fracture-fill in pyrite, tourmaline, and carbonate, and as disseminated grains along grain boundaries. Ormaque is dominated by extensional veins and differs from other Val-d'Or deposits, which are either dominated by fault-fill veins (e.g., Triangle, Plug No. 4, and Mine No. 3) or comprise both fault-fill and extensional veins in more equal proportions (e.g., Sigma, Lamaque, and Mine No. 2 deposits). All deposits are hosted by misoriented faults, which either cut through ca. 2685 Ma competent plugs (first group of deposits) or C porphyry (second group of deposits). Ormaque further differs from these deposits by a near lack of fault-fill veins and its more severely misoriented, steeply N-and S-dipping faults. The latter are reactivated, and extensional veins form at supralithostatic fluid pressures and low differential stress. With increasing misorientation angle, the maximum differential stress for shear reactivation of faults decreases, and the range of differential stresses over which extensional veins can form increases. The higher reactivation angles (80 degrees) of the faults at Ormaque likely favored the formation of extensional veins rather than fault-fill veins over a wider range of differential stress and resulted in a predominance of extensional veins. Using failure mode diagrams, the study highlights how differences in reactivation angles may relate to the reactivation of preexisting high-angle faults and rotation of new faults during regional horizontal shortening, which led to differences in deposit style across a single mining district.
The current study explores the synthesis, structural characterization, and pharmacological assessment of 9,9-dibutylfluorene-2-carboxylic acid, focusing on its potential as an inhibitor of dihydrofolate reductase (DHFR), a crucial enzyme in cancer treatment. SC-XRD confirmed its molecular structure, detailing essential bond lengths and angles, while Hirshfeld surface analysis identified significant intermolecular interactions primarily driven by H-bonding and van der Waals forces. Density Functional Theory (DFT) revealed stable electronic properties, providing deeper insight into the optimized geometric parameters. Molecular docking established a strong binding affinity to DHFR, indicating promising inhibitory effects. Furthermore, pharmacokinetic analysis suggested favorable drug-like properties, including high gastrointestinal absorption. Together, the findings present this compound as a fascinating candidate for future development as a fluorene-based anticancer agent.
Complex breccia host rocks, quartz-topaz alumina-rich alteration, and low-sulfide ore (<3%) differentiate the Akulla Au-Te deposit from nearby volcanogenic massive sulfide (VMS) deposits, which are the main deposit type in the Skellefte district. At Akulla, mineralization comprises native gold and telluride minerals in disseminated, remobilized fracture-associated, quartz vein-associated, and sulfide-associated styles within a steeply dipping lens-shaped domain of strongly altered 1.9 Ga dacitic to andesitic volcanic rocks. The host rocks and mineralization are flattened and elongated subparallel to the main D2 tectonic foliation and lineation and are metamorphosed to upper greenschist facies. The deposit has an almost concentrically zoned hydrothermal alteration pattern with a quartz-topaz-rich core that is centered on a breccia complex. Topaz occurs as discrete altered clasts in the breccias as well as pervasive to patchy alteration. The quartz-topaz-sericite-andalusite core is poor in sulfide and passes outward to sericite-andalusite +/- corundum +/- quartz +/- chlorite associations, then to sericite and finally chlorite. Stringer veins and small semimassive to massive base metal sulfide lenses occur in the alteration zones outside the topaz core, continue similar to 300 m updip to the Akulla Ostra massive sulfide deposit, and resemble footwall alteration and mineralization associated with nearby VMS deposits. Four main breccia facies are identified based on textural characteristics: monomict jigsaw-fit breccia; poorly sorted, dominantly polymict breccia with rotated clasts; moderately sorted matrix-supported polymict breccia; and well-sorted breccias with graded bedding. These breccias are attributed to quench and hydrothermal brecciation in a sea-floor to subseafloor setting during emplacement of a dacitic-andesitic volcanic complex. Clast size grading within breccia facies with topaz-rich clasts is dominated by fining to the northeast, the same direction as in nearby volcaniclastic sedimentary rocks, indicating that these breccias were emplaced while the strata were flat lying or gently dipping. This constrains the formation of the topaz-rich breccias and Au-Te mineralization to the early synvolcanic evolution of the succession, possibly prior to or during rotation of strata in extensional fault blocks. The topaz-and alumina-rich alteration of the breccias is attributed to acidic, F-rich, probably magmatic-hydrothermal fluids. The Akulla Au-Te deposit represents unusual, F-rich, subseafloor synvolcanic mineralization within a larger VMS mineral system. The relationship we demonstrate between VMS mineralization, sulfide-poor Au-Te mineralization, complex breccias, and magmatic ore fluids at Akulla will modify exploration models for VMS mineralization in the Skellefte district and should be considered in other VMS districts.
