Search Results (42)

We report, for the first time, waimirite-(Y) in Egypt. This is only the third reported occurrence of this mineral in the world. This observation arose during our study of the rare earth element (REE) mineralization associated with the Neoproterozoic rare-metal granite intrusion in Wadi Abu Rusheid in the Eastern Desert of Egypt. The principal lanthanide and yttrium (Y) hosts in the area are waimirite-(Y) and bastnäsite-(Ce) in leucogranite and bastnäsite-(Y) in adjacent metasedimentary country rock. The leucogranite is a strongly fractionated, metaluminous to weakly peraluminous (A/CNK = 0.98–1.03), medium- to high-K calk-alkaline I-type granite. The metasediments are composed of upper greenschist to lower amphibolite-grade biotite schists with variable amounts of amphibole, graphite, and garnet. Leucogranite contains accessory Li-bearing mica, garnet, zircon, fluorite, and columbite in addition to the REE minerals. It is enriched by three orders of magnitude relative to primitive mantle in Li, Rb, Th, Ta, Nb, Pb, U, and Sn; relative to these highly enriched elements the concentrations of Sr, Ba, Ga, Zr, Hf, and Y are notably low. The REE patterns of most samples show strong enrichment in heavy relative to light REE but occasional samples have light REE-enriched patterns controlled by accessory REE minerals, and all display strong negative Eu anomalies (Eu/Eu* ≤ 0.05). The whole-rock chemistry of the metasedimentary units are different; relative to average upper continental crust they show enrichments of one to two orders of magnitude in Li, Rb, Pb, Sn, Cs, and sometimes Cr and Zn. The REE patterns of the metasedimentary units are nearly flat, with some samples showing negative Eu anomalies. Waimirite-(Y), nominally YF₃, also contains several weight percent each of Yb, Dy, and Er. The empirical formula (based on one cation) is (Y_0.55Ce_0.02Pr_0.01Nd_0.02Sm_0.02Gd_0.02Dy_0.05Er_0.04Yb_0.05Th_0.05Ca_0.16Pb_0.01)_∑1.00(F_2.48O_0.52)_∑3.00. Bastnäsite-(Ce) in leucogranite samples, nominally Ce(CO₃)F, also has several weight percent each of Nd₂O₃ and La₂O₃. The REE host in metasedimentary rocks is bastnäsite-(Y), nominally Y(CO₃)F, but also rich in Nd₂O₃ (11–19 wt.%) and La₂O₃ (4–14 wt.%). It is intimately associated with fluorophlogopite. The geochemical, mineralogical, and textural evidence indicates that waimirite-(Y) and bastnäsite-(Ce) in leucogranite crystallized from granite-derived F- and CO₂-bearing hydrothermal fluids, whereas the source of Y for growth of the bastnäsite-(Y) in the metasedimentary rocks is unclear; the large negative Ce anomaly in bastnäsite-(Y) suggests an oxidizing supergene setting. Despite their proximity, if there is a genetic connection between the mineralization in the granite and in its country rocks, the relationship is not evident from elemental patterns or host mineralogy. Full article

Kutná Hora ore district, one of the largest historical silver deposits in Central Europe, consists of nine major lodes with Pb-Zn-Ag mineralization hosted by high-grade basement rocks of the Kutná Hora Crystalline Complex in central part of the Bohemian Massif. We conducted a detailed electron-microprobe study of a previously unknown ore mineralization from the uppermost level of the Muzejní důl mine, which is a medieval mine located within the Ag-richest Oselské pásmo Lode, in the southern part of the ore district. An unusual nature of this ore mineralization, which originated during three respective stages, was found. The early stage comprises the hypogene mineralization commonly occurring in the southern part of the district, composed of pyrite, arsenopyrite, Fe,Mn-enriched sphalerite, galena, and (keno)argentotetrahedrite-(Fe) hosted in quartz and siderite-rhodochrosite gangue. The second stage was characterized by the corrosion of early vein fill followed by the crystallization of a specific suite of ore minerals anomalously enriched in Ag, Cu, Zn, Cd, As, and Sb, including galena, Cd-enriched and Fe-poor sphalerite, greenockite, bornite, Ag,As,Sb,Mn-bearing chalcopyrite, silver, gold, stephanite, As,Cu-bearing pyrargyrite, Ag-Cu- and Sb-As-bearing polybasite-pearceite group minerals and a suite of tetrahedrite-group minerals, the latter showing wide variations in Ag-Cu, Sb-As, and Fe-Zn-Cd contents. The origin of the second-stage mineralization is interpreted in hydrothermal remobilization of ore metals and metaloids from the early ore mineralization, which was mediated by surficial fluids characterized by elevated redox potential. The third stage comprises acanthite and probably also Ag-Cu minerals (stromeyerite, jalpaite, and mckinstryite), Cu-S phases (covellite, spionkopite, geerite), and an Ag-Cu-Hg mineralization. This late mineralization was likely related to the pre-Cretaceous weathering of the apical part of the ore deposit and to the associated supergene enrichment of deeper parts of the ore zone by descending Ag,Cu-bearing waters. Full article

The assessment of systemic congestion in acute heart failure (AHF) remains clinically challenging, particularly across different left ventricular ejection fraction (LVEF) phenotypes. This study aimed to evaluate whether differences exist in the degree of congestion, assessed through a multimodal approach including physical examination, biomarkers (NT-proBNP, CA125), and point-of-care ultrasound using the Venous Excess Ultrasound (VExUS) protocol, between patients with preserved (HFpEF) and reduced ejection fraction (HFrEF). We conducted a prospective observational study involving 90 hospitalized AHF patients, 80 of whom underwent a complete VExUS assessment. Although patients with HFrEF exhibited higher levels of NT-proBNP and CA125, and more frequent signs of third-space fluid accumulation such as pleural effusion and ascites, no statistically significant differences were found in VExUS grades between the two groups. These findings suggest that the VExUS protocol provides consistent and reproducible information on systemic venous congestion, regardless of LVEF phenotype. Its integration into clinical practice may help refine congestion assessment and optimize diuretic therapy. Further multicenter studies with larger populations are warranted to validate its diagnostic and prognostic utility and to determine its potential role in guiding individualized treatment strategies in AHF. Full article

Background: Cytokine release syndrome (CRS) is a life-threatening systemic inflammatory condition marked by excessive cytokine production, leading to multi-organ dysfunction. It is commonly associated with T-cell-engaging therapies such as chimeric antigen receptor (CAR) T cells, T-cell receptor bispecific molecules, and monoclonal antibodies. Carfilzomib, a proteasome inhibitor, is known to cause a range of adverse effects, primarily hematologic and cardiovascular. However, multiorgan failure grade 5 (fatal), resembling CRS has not been previously reported in association with Carfilzomib. Case Report: A 74-year-old male with relapsed multiple myeloma developed grade 5 multiorgan failure 60 min after the third dose of Carfilzomib, resulting in death within 24 h of symptom onset. The patient tolerated the first doses of Carfilzomib well with only fever and headache developing post infusion. Before the second dose, the patient developed worsening pancytopenia, prompting the discontinuation of Lenalidomide. After the second Carfilzomib infusion, he experienced fever and transient encephalopathy, which resolved with acetaminophen, corticosteroids, and supportive care. However, following the third dose, he rapidly deteriorated—developing fever, tachycardia, hypotension, hypoxia, and encephalopathy. Despite aggressive management with intravenous fluids, broad-spectrum antibiotics, corticosteroids, and tocilizumab, the patient progressed to refractory shock and multi-organ failure, culminating in death within 24 h. A comprehensive infectious workup was negative, ruling out sepsis and suggesting possible Carfilzomib-induced CRS. Conclusion: Grade 5 multiorgan failure with signs and symptoms similar with CRS following Carfilzomib administration is a rare but potentially fatal adverse drug reaction. Further research is needed to better define the risk factors and optimal management strategies for Carfilzomib-induced multiorgan failure and possible CRS. Full article

Objectives: To evaluate the efficacy of faricimab in patients with neovascular age-related macular degeneration (nAMD) that did not respond to other VEGF inhibitors. Methods: This retrospective study included the eyes of patients diagnosed with nAMD who had been switched to faricimab treatment due to the persistence of intraretinal fluid (IRF) and/or subretinal fluid (SRF), despite monthly anti-VEGF treatment with aflibercept, bevacizumab, or ranibizumab using the treat and extend regimen, and who had received at least three faricimab injections following the switch. Best-corrected visual acuity (BCVA) measurement and optical coherence tomography (OCT) analysis were performed at each visit, and the OCT results were graded by two independent readers. Results: We included 41 eyes of 39 patients (21 male, 18 female) with a mean age of 80.5 ± 8.1 years. The median duration of anti-VEGF treatment prior to the switch to faricimab was 5.0 years, with a median of 53 injections. Complete resolution of IRF and SRF was observed after the first dose of faricimab in 12 eyes (29.3%) and after the third dose in 15 eyes (36.6%). Twenty-eight eyes reached a follow-up time after a switch of at least 12 months, with a median of 10 faricimab injections. Of these 28 eyes, 10 eyes (35.7%) exhibited complete IRF/SRF resolution; treatment intervals were extended beyond 4 weeks in 21 eyes (80.7%), and 8 eyes (28.6%) presented complete IRF/SRF resolution under extended treatment intervals at month 12. Central retinal thickness after 12 months was reduced from a median of 368.0 µm to 297.5 µm (p < 0.001), and the BCVA remained stable (p = 0.057). No adverse events were reported throughout the entire treatment period. Conclusions: In nAMD patients with poor anti-VEGF treatment response, complete and fast fluid resolution and the extension of treatment intervals can be reached by switching to faricimab, even after years of prior unsuccessful therapy. Full article

This paper addresses the mixed convective flow and heat transfer in combustible third-grade fluids through a slant porous channel filled with permeable materials. The fluid layer in contact with the channel wall is exposed to asymmetrical slippage and isothermal conditions. We employ the spectral Chebyshev collocation method (SCCM) to the coupled nonlinear flow governing equations and validate using the Shooting–Runge–Kutta method (RK4). Fluid velocity and temperature profiles, local entropy generation, and irreversibility ratio are computed and analyzed quantitatively and qualitatively. The convergence of the numerical method was demonstrated. The flow and thermal effects results, entropy generation rate, and Bejan number revealed fascinating manifestations that have profound implications in the design of thermo-mechanical systems. In particular, the thermal analysis results are pertinent to optimal system designs that achieve efficient energy utilization. Full article

In this work, we propose a new three-dimensional constitutive equation related to a third-grade fluid. This proposal is based on experimental work for which the viscosity term and the terms related to viscoelasticity may depend on the shear rate, in accordance with a power-law type model. The numerical implementation of this fluid model is rather demanding in terms of computational calculation and, in this sense, we use the Cosserat theory related to fluid dynamics, which makes the transition from the three-dimensional fluid model to a one-dimensional fluid model for a specific geometry under study which, in this case, is a straight tube with constant circular cross-section. Based on this approximation theory, the one-dimensional fluid model is solved by assuming an ordinary differential equation involving: an unsteady mean pressure gradient; an unsteady volume flow rate; the Womersley number; and the viscosity and viscoelasticity parameters. Consequently, for specific data, and using the Runge–Kutta method, we can obtain the solution for the unsteady volume flow rate and we can present simulations to the three-dimensional velocity field. Full article

In this study, the Kevin–Voigt viscoelastic constitutive relationship is used to investigate the vibration characteristics and stability of a functionally graded viscoelastic(FGV) fluid-conveying pipe with initial geometric defects under thermal–magnetic coupling fields. First, the nonlinear dimensionless differential equations of motion are derived by applying Timoshenko beam theory. Second, by solving the equilibrium position of the system, the nonlinear term in the differential equations of motion is approximated as the sum of the longitudinal displacement at the current time and longitudinal displacement relative to the position, and the equations are linearized. Third, these equations are discretized using the Galerkin method and are numerically solved under simply supported conditions. Finally, the effects of dimensionless temperature field parameters, dimensionless magnetic field parameters, thermal–magnetic coupling, initial geometric defect types, and the power-law exponent on the complex frequency of the pipe are examined. Results show that increasing the magnetic field intensity enhances the critical velocity of first-order mode instability, whereas a heightened temperature variation reduces the critical velocity of first-order diverge instability. Under thermal–magnetic fields, when the magnetic field intensity and temperature difference are simultaneously increased, their effects on the complex frequency can partially offset each other. Increasing the initial geometric defect amplitude increases the imaginary parts of the complex frequencies; however, for different types of initial geometric defect tubes, it exhibits the most distinct influence only on a certain order. Full article

The complex multiphase morphology of thermoplastic elastomers based on styrene-block copolymers (TPSs) affects their flow behavior significantly and in a way which may not be considered by commonly used characterization and evaluation procedures. To evaluate the relevance of non-Newtonian flow phenomena for the validity of rheometric data in processing, three commercially available TPSs with comparable hardness of about 60 Shore A but with different application fields were selected and characterized using parallel plate and high-pressure capillary rheometry. The validity of the rheometric data is assessed by modeling the flow in a high-pressure capillary rheometer by a computational fluid dynamics (CFD) simulation. The results were discussed in conjunction with close-up images of samples taken after the measurement. The materials show clearly different rheological behaviors but depend on the respective shear and geometrical conditions. In particular, for the material with the lowest viscosity, doubling the capillary diameter resulted in a disproportionate increase of the pressure loss by up to one third. Only the capillary flow of this material could not be reproduced by the CFD simulation. The results indicate that conventionally determined rheometric data of TPSs are of limited use in evaluating process flows for various material grades. Full article

In this work, an artificial neural network based on the Cuckoo search algorithm (CS-ANN) is implemented for squeezing flow problems. Three problems are considered: the squeezing flow, the MHD squeezing flow, and the flow of the third-grade fluid past a moving belt. First, the approximation for the said nonlinear differential equations is explained and the proposed problems are transformed into the $L_2$ norms of minimization problems. Then, a well-known Cuckoo search algorithm is used to minimize the norms of each problem to get the best set of weights for artificial neural networks. The outcome of the proposed method is displayed through graphs. Two cases for each problem are discussed consisting of the solution, error, weights, and fitness function, respectively. The numerical results for the state variables are displayed in Tables. The error analysis in each case proves the accuracy of our implemented technique. The results are validated through graphs by comparing CS-ANN results with the gradient descent method. Full article

The Golden Ridge gold deposit is located in southwestern New Brunswick, in the Canadian Appalachians. Gold mineralization is consistently associated with acicular arsenopyrite, and to a lesser degree with pyrite, disseminated in host rocks, sulphide veinlets, quartz-carbonate veins, and the breccia matrix. According to petrographic-based textural differences, four types of pyrite and two types of arsenopyrite are recognized with associated assemblages. Based on SEM-BSE imaging and LA-ICP-MS spot analyses of the different types of pyrites and arsenopyrites, “invisible gold” (solid solution in the crystal lattice of pyrite and arsenopyrite or <100 nm nanoparticles) and micrometer-size inclusions were identified as the main forms of Au. Four syn-gold mineralization pulses of fluid are suggested. The initial hydrothermal fluid, which generated low-grade pyrite (Py-I) enriched in Sb, Pb, Cu, Co, Ni, and Bi, was followed by a second pulse of fluid enriched in arsenic and gold, generating coprecipitated Py-II and Asp-I. The third and fourth pulses were enriched in both arsenic and gold and precipitated Py-III, then coprecipitated Py-IV and Asp-II, which constitute the most important Au depositional episodes. The repeated occurrence of growth zones with Au enrichment in the arsenian pyrites (Py-II, Py-III, and Py-IV) indicate surface growth during metal deposition and disequilibrium crystallization processes. Full article

The Western Syncline hosts reduced-facies, or Kupferschiefer-type, sedimentary rock-hosted stratiform Cu deposits (SSC) in the lowermost meters of the Nonesuch Formation, which is part of a thick section of clastic sedimentary rocks that comprise the upper fill of the Mesoproterozoic Midcontinent Rift of North America. Located in the Porcupine Mountains Cu district in Upper Peninsula, Michigan, these blind deposits were discovered in 1956, but are not yet developed, although recent renewed interest may result in near-term production. The deposits are distinguished by their relatively undeformed nature and lack of superposed hydrothermal events. Prior to lithification, chalcocite mineralization replaced diagenetic pyrite within two discrete tabular, albeit discontinuous, potential orebodies referred to as the lower Cu-bearing sequence (LCBS) and the upper Cu-bearing sequence (UCBS). The Top Cu Zone transgresses lithologic boundaries, suggesting that a limited volume of Cu-bearing fluids moved vertically upwards through the unlithified stratigraphy, since reductant pyritic rocks above this zone are essentially barren of Cu. The total Cu inventory that has a reasonable expectation of economic extraction is 3678 M lbs. of Cu with 15.3 M oz. of byproduct Ag. When a cutoff grade of 0.9% Cu over a minimum thickness of 2 m is applied to justify an underground room-and-pillar mine, the LCBS and UCBS are not continuous over the Western Syncline. Sedimentology is the first-order control of potential ore and its continuity; dark-gray shales and siltstones deposited under low-energy, anoxic conditions are preferred host rocks, whose thickness must be >2 m to be potential ore since host-rock thickness determines economic viability of extraction. Furthermore, stratigraphy influences the time constraints on mineralization as the lithification process impedes vertical permeability and thus the flow of Cu-bearing fluids upward through the unlithified section. Syn-sedimentary tectonic movements, likely along pre-existing buried faults, are a third-order control as the thickness of host rocks is enhanced under such conditions. Therefore, an understanding of the depositional and tectonic history throughout the Western Syncline is fundamental to understanding the limits of possible economic exploitation and to optimizing ore extraction. Full article

The selection of the recipient mare is one of the most important factors involved in the success of equine embryo transfer. The aim of this study was to determine whether the age of the recipient, the number of transfers and the detection of intrauterine fluid during the follicular phase or after ovulation can affect pregnancy rate at 14 and 45 days (PR 14 and PR 45) or early embryonic loss (EEL). A total of 1222 ETs were included in the study. Mares receiving the first embryo of the year had a higher PR 14 and 45 days compared to mares at the third transfer (78.8% and 70.1% vs. 65.6% and 54.1%, respectively). The detection of intrauterine fluid post ovulation negatively affected PR 14 (60.5% vs. 77.6%) and should therefore be considered an abnormal finding, probably being a sign of uterine inflammation or delayed uterine clearance. On the contrary, the age of the recipient mare and detection of fluid during follicular phase did not affect PR 14. Only the age of the recipient mare influenced the EEL, since mares aged 10–13 years had a higher EEL compared to mares aged 3–5 years (15.6% vs. 6.4%). Embryo size and grade affected PR 14 and 45. Full article

A mathematical investigation of a thermodynamical system linked with energy management and its impact on the environment, especially climate change, is presented in this study. In this regard, a numerical investigation of the flow and heat transfer of hydromagnetic third-grade liquid through a porous medium. The permeability of the medium and electrical conductivity of the fluid are assumed to be temperature functions. The appropriate mathematical formulations for momentum, energy, and entropy equations are presented in both dimensional and dimensionless forms. We obtained the numerical solutions using the spectral version of the Chebyshev collocation method and compared the result with the shooting Runge–Kutta method. Numerical results for velocity, temperature, entropy, and Bejan profiles are communicated through tables and graphs with adequate physical interpretation. The thermal stability of the thermo-fluid system that guarantees the prevention of spontaneous fluid heating that fuels climate change is also included in the analysis. Full article

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) directed therapy emerged as a treatment of peritoneal metastasis (PM) a decade ago. The response assessment of PIPAC is not uniform. This narrative review describes non-invasive and invasive methods for response evaluation of PIPAC and summarizes their current status. PubMed and clinicaltrials.gov were searched for eligible publications, and data were reported on an intention-to-treat basis. The peritoneal regression grading score (PRGS) showed a response in 18–58% of patients after two PIPACs. Five studies showed a cytological response in ascites or peritoneal lavage fluid in 6–15% of the patients. The proportion of patients with malignant cytology decreased between the first and third PIPAC. A computed tomography showed stable or regressive disease following PIPAC in 15–78% of patients. The peritoneal cancer index was mainly used as a demographic variable, but prospective studies reported a response to treatment in 57–72% of patients. The role of serum biomarkers of cancer or inflammation in the selection of candidates for and responders to PIPAC is not fully evaluated. In conclusion, response evaluation after PIPAC in patients with PM remains difficult, but PRGS seems to be the most promising response evaluation modality. Full article