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Hydrometallurgical gold recovery processes play a pivotal role in the gold mining industry, contributing to more than 90% of global gold production. Among the array of techniques available, the Merrill–Crowe process, adsorption, ion exchange, and solvent extraction are central in extracting gold from leach solutions. While the Merrill–Crowe process and gold complex adsorption onto activated carbon represent historical cornerstones, their inherent limitations have prompted the emergence of more recent innovations in ion exchange and solvent extraction, offering enhanced selectivity, control, and sustainability. The evolution of modern organic chemistry has significantly influenced the progress of ion exchange technology, mainly through the introduction of advanced polymer matrix synthetic resins. At the same time, novel solvents tailored to gold complex interactions have revitalized ion exchange and solvent extraction. Introducing ionic liquids and deep eutectic solvents has also added a new dimension to efforts to improve gold extraction metallurgy. This paper reviews these cutting-edge developments and their potential to revolutionize the hydrometallurgical gold recovery process, addressing the pressing need for improved efficiency and environmental responsibility. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to evaluate the accuracy of 12 intraocular lens (IOL) power calculation formulae for eyes that have undergone both radial keratotomy (RK) and laser assisted in situ keratomileusis (LASIK) surgery to determine the efficacy of various IOL calculations for this unique patient group. Currently, research on this surgical topic is limited. Methods: In this retrospective study, 11 eyes from 7 individuals with a history of RK and LASIK who underwent cataract surgery at Hoopes Vision were analyzed. Preoperative biometric and corneal topographic measurements were performed. Subjective refraction was obtained postoperatively. Twelve different intraocular lens (IOL) power calculations were used: Barrett True K No History, Barrett True K (prior LASIK, Prior RK history), Barrett Universal 2, Camellin-Calossi-Camellin (3C), Double K-Modified Holladay, Haigis-L, Galilei, OCT, PEARL-DGS, Potvin-Hill, Panacea, and Shammas. Results: The rankings of mean arithmetic error (MAE), from least to greatest, were as follows: 3C (0.088), Haigis-L-L (− 0.508), Shammas (− 0.516), OCT Average (− 0.538), Barrett True K (− 0.557), OCT RK (− 0.563), Galilei (− 0.570), IOL Master (− 0.571), OCT LASIK (− 0.583), Barrett True K No History (− 0.597), Pearl-DGS (− 0.606), Potvin-Hill SF (− 0.770), Potvin-Hill TNP (− 0.778), Panacea (− 0.876), and Barrett Universal 2 (− 1.522). The 3C formula achieved the greatest percentage of eyes within ± 0.25 D of target range (91%), while Haigis-L, Shammas, Galilei, Potvin Hill, Barrett True K, IOL Master, PEARL-DGS, and OCT formulae performed similarly, achieving 45% of eyes within ± 0.75D of target refraction. Conclusion: This study demonstrates the accuracy of the lesser known 3C formula in IOL calculation, particularly for patients who have undergone both RK and LASIK. Well-known formulae, such as Haigis-L, Shammas, and Galilei, which are used by the American Society of Cataract and Refractive Surgery (ASCRS), are viable options, although 3C formulae should be considered in this patient population. Furthermore, larger studies can confirm the best IOL power formulas for post-RK and LASIK cataract patients. [ABSTRACT FROM AUTHOR]

Purpose: To compare the vault predictability of most available implantable collamer lens (ICL) sizing nomograms and identify which preoperative measurements are predictive of vault. Setting: Private practice in Draper, Utah. Design: Retrospective chart review. Methods: This study was a retrospective analysis of 209 eyes of 106 patients who underwent STAAR Surgical ICL implantation. Analyses were performed based on the availability of preoperative parameters, varying the number of eyes for each test. Mean absolute error (MAE) of predicted vs actual postoperative vault was calculated for each nomogram. The frequency of Kim, Rocamora (least absolute shrinkage and selection operator-optical coherence tomography), Russo, and Reinstein recommending the correct ICL size in instances when Parkhurst, optimized white-to-white (WTW), and STAAR could not recommend a definitive ICL size was determined. Univariate and multivariate linear regression analysis was performed between preoperative measurements and vault. Results: The Kim, Rocamora, Russo, and Reinstein nomograms had significantly lower MAE of predicted vs actual postoperative vault than the KSV2 and Nakamura V3 nomograms. The Russo formula most frequently recommended the correct ICL size when the Parkhurst, Optimized WTW, and STAAR nomograms could not provide ICL size recommendations. At the 0.05 significance level, anterior chamber depth (ACD), ciliary body inner diameter (CBID), and pupil diameter were the parameters found to have significant correlation with postoperative vault. Conclusions: The Kim, Rocamora, Russo, and Reinstein nomograms were the most predictive of vault. Additionally, ACD, CBID, and pupil diameter were found to be significantly correlated with vault and should be considered for use in future ICL sizing nomograms. [ABSTRACT FROM AUTHOR]

Direct write technology using special inks consisting of finely dispersed metal nanoparticles in liquid is receiving an undivided attention in recent years for its wide range of applicability in modern electronic industry. The application of this technology covers radio frequency identification-tag (RFID-tag), flexible-electronics, organic light emitting diodes (OLED) display, e-paper, antenna, bumpers used in flip-chip, underfilling, frit, miniresistance applications and biological uses, artificial dental applications and many more. In this paper, the authors have reviewed various direct write technologies on the market and discussed their advantages and shortfalls. Emphasis has given on microdispensing deposition write (MDDW), maskless mesoscale materials deposition (M3D), and ink-jet technologies. All of these technologies allow printing various patterns without employing a mask or a resist with an enhanced speed with the aid of computer. MDDW and M3D are capable of drawing patterns in three-dimension and MDDW, in particular, is capable of writing nanoinks with high viscosity. However, it is still far away for direct write to be fully implemented in the commercial arena. One of the hurdles to overcome is in manufacturing conductive inks which are chemically and physically stable, capable of drawing patterns with acceptable conductivity, and also capable of drawing patterns with acceptable adhesiveness with the substrates. The authors have briefly discussed problems involved in manufacturing nanometal inks to be used in various writing devices. There are numerous factors to be considered in manufacturing such inks. They are reducing agents, concentrations, oxidation, compact ability allowing good conductivity, and stability in suspension. [ABSTRACT FROM AUTHOR]

Azide-alkyne cycloaddition is a powerful reaction for the formation of bioconjugates. When catalyzed by Cu(I) or strain promotion, this cycloaddition is considered to be a "click" reaction with many applications in chemical biology and materials science. We report a new type of azide-alkyne click chemistry for the synthesis of protein conjugates using cucurbit[6]uril (CB6) supramolecular chemistry. CB6-promoted azide-alkyne cycloaddition has been previously used for the synthesis of rotaxanes but has not been applied to the development of complex bioconjugates. By developing new substrates for CB6 click that do not contain any cross-reactive functional groups and by optimizing reaction conditions, we converted CB6 click chemistry from a rotaxane synthesis tool into a useful bioconjugation technique. Using these new parameters, we synthesized a series of protein conjugates including protein-peptide, protein-DNA, protein-polymer, and protein-drug conjugates. We further demonstrated that CB6 click can be used in conjunction with strain-promoted azide-alkyne cycloaddition to generate distinct bioconjugates in protein mixtures. CB6 click is a promising new reaction for the development of protein conjugates and can be applied toward the synthesis of complex biomaterials for a wide range of applications. [ABSTRACT FROM AUTHOR]

Optimization of the acid leaching process for Mongolian apatite-based ore containing rare-earth elements (REEs) was studied. The ore contained approximately 10% of REEs as total rare earth oxides, and the major impurities were Ca (33% as CaO) and Fe (23% as Fe2O3). Fe bearing minerals could be removed by passing the sample through a wet high-intensity magnetic separator before leaching. After magnetic separation, basic leaching tests were conducted to investigate the influence of the acid type and concentration, temperature, and the pH on the REE leaching level and kinetics. Hydrochloric acid was found to be the most effective leaching agent, leaching more than 90% of REEs in an hour. However, the concentrations of Ca ions in the leachate were also high, which would complicate recovery of the REEs. Therefore, to reduce the amount of Ca ions in the leachate, a two-stage leaching procedure was attempted. In stage 1, the sample was preleached using 1.0 M hydrochloric acid to dissolve Ca. In stage 2, the solid residue of stage 1 was leached using 2.0 M hydrochloric acid to dissolve REEs. Consequently, this two-stage leaching significantly reduced the Ca concentration in the final leachate without affecting the leaching levels of REEs. [ABSTRACT FROM AUTHOR]

The selective precipitation of rare earth elements (REEs) in acidic media often plays a key role in the effective extraction of these elements from various sources such as ores and recycling streams. In this study, the precipitation characteristics of REEs with sulfate, a frequently used precipitant, were carefully examined, and the results were compared with those of other precipitants, such as phosphate, oxalate, and fluoride/carbonate systems. Emphasis is given on various forms of precipitates, such as anhydrous sulfate, octa-hydrated sulfate, and sodium double salt, in which the sodium double salt was compared with the anionic double salt precipitation of the fluoride-carbonate system. It was found that anions such as Cl−, NO3−, and SO42− play an important role in the precipitation behavior, particularly through complexation with the dissolved REEs. In general, the effectiveness of precipitation follows the order of sodium double salt, a hydrated form of sulfate, and anhydrous sulfate. In this study, it was observed that the synergistic role of a double salt precipitation, either cationic or anionic, is frequently as effective as that of oxalate and phosphate, even in a low pH range. [ABSTRACT FROM AUTHOR]

The progress made in aging research using laboratory organisms is undeniable. Yet, with few exceptions, these studies are conducted in a limited number of isogenic strains. The path from laboratory discoveries to treatment in human populations is complicated by the reality of genetic variation in nature. To model the effect of genetic variation on the action of the drug rapamycin, here we use the growth of Drosophila melanogaster larvae. We screened 140 lines from the Drosophila Genetic References Panel for the extent of developmental delay and found wide‐ranging variation in their response, from lines whose development time is nearly doubled by rapamycin, to those that appear to be completely resistant. Sensitivity did not associate with any single genetic marker, nor with any gene. However, variation at the level of genetic pathways was associated with rapamycin sensitivity and might provide insight into sensitivity. In contrast to the genetic analysis, metabolomic analysis showed a strong response of the metabolome to rapamycin, but only among the sensitive larvae. In particular, we found that rapamycin altered levels of amino acids in sensitive larvae, and in a direction strikingly similar to the metabolome response to nutrient deprivation. This work demonstrates the need to evaluate interventions across genetic backgrounds and highlights the potential of omic approaches to reveal biomarkers of drug efficacy and to shed light on mechanisms underlying sensitivity to interventions aimed at increasing lifespan. [ABSTRACT FROM AUTHOR]

Introduction: Amphetamine-based medications such as Adderall®, used for the treatment of attention deficit-hyperactivity disorder (ADHD), may theoretically elicit angle closure through their adrenergic mechanisms. The relationship between the use of implantable collamer lenses (ICLs) and angle closure has been extensively investigated based on appropriate vault and lens sizing and postoperative changes in the anterior chamber angle (ACA) and corneal morphology. This case reflects a synergistic impact from both Adderall® use and ICL implantation for the proposed mechanism of angle closure. Case Presentation: A 36-year-old myopic female with ADHD controlled with Adderall® underwent toric ICL implantation in the right eye after undergoing preoperative laser peripheral iridotomy. Shortly after, the patient developed episodic angle closure in the right eye, with episodes mainly occurring after taking an additional dose of Adderall® in a dimly lit environment. The patient later had an ICL exchange with a smaller sized EVO+ toric ICL in the right eye and remained asymptomatic after. Conclusion: Additive mechanisms from both the ICL and Adderall® were present in our patient. The ICL caused crowding of the ACA through a pseudophacomorphic mechanism, and the Adderall® caused increased iridotrabecular contact secondary to pharmacologic mydriasis. This resulted in episodic angle closure with subsequent spikes in the intraocular pressure. There are no current reports or studies in the current literature describing the combined mechanisms of ICL implantation and Adderall® use in the potential development of angle closure. Further studies may be done to assess interactions of such medications in patients after ICL implantation. [ABSTRACT FROM AUTHOR]

Rare earth elements (REEs) are of great importance to modern society and their reliable supply is a major concern of many industries that utilize them in metal alloys, semiconductors, electrical equipment, and defense equipment. REEs in the coal waste have been revealed to be an alternative resource for REEs production. In this study, the extraction, recovery, and upgrading of the REEs from coal waste has been realized with the bioleaching and precipitation processes. Reliable and sustainable acid and oxidant production from the oxidation of the pyrite with Acidithiobacillus ferrooxidans to generate acid for leaching were realized in this research. The acidified bioleaching solution was used to extract REEs from coal waste, with 13–14% yields for most REE elements (~72 h of leaching). However, recovery for longer duration tests was significant higher (varies from 40–60% for individual REEs). After extraction, precipitation and separation processes were designed with the aid of Visual Minteq calculations and modeling to concentrate the REEs. With the procedures designed in this research, a final REEs precipitate product containing 36.7% REEs was produced. [ABSTRACT FROM AUTHOR]

The effective and selective leaching of rare earth elements (REEs) from various sources is frequently possible in practice by adopting a carefully coordinated strategy incorporating a selective precipitation of these elements from undesired ones in solution. In this study, the behavior of chemical precipitation of REEs with commonly used precipitants such as sulfate, carbonate, fluoride, phosphate, and oxalate was examined using thermodynamic principles and calculations. It was found that the pH of the system has a profound effect on determining particular chemical species of precipitants, which are subsequently responsible for the precipitation of REEs. The role of various anions such as Cl−, NO3−, and SO42− derived from the acid used in the leaching process on the precipitation behavior of REEs was examined. These anions form complexes with REEs and display a very positive effect on the precipitation behavior. The nitrate environment exhibits most conducive to precipitation followed by sulfate and then chloride. [ABSTRACT FROM AUTHOR]

Copper nano-ink has been synthesized in various kinds of alcohol with carbon chain of 1 through 5 using a direct reduction by hydrazine. The solubility of copper nitrate was best with methanol and decreased dramatically when the chain length increased. The nano-ink prepared using copper in alcohol was then compared with those prepared in distilled water under the same conditions. The results have shown that methanol is a better medium than water in that oxidation of copper in alcohol was minimized and the size of nano-particles was much smaller than those prepared in water under similar conditions. [ABSTRACT FROM AUTHOR]

Abstract: The redox behavior of vanadate ions in alkaline solutions has been studied with NaOH concentration ranging from 0.1M to 1M. The cyclic voltammetry results reveal that vanadate ions are irreversibly reduced to V(OH)2 via a three-electron transfer reaction, and the first electron transfer reaction is the rate-determining step. The oxidation processes involve the stepwise oxidation of V(OH)2 to V(OH)3, and V(OH)3 to vanadate ions. The reduction kinetics is discussed and the diffusion coefficient of vanadate ion is calculated to be 1.40×10−9 m2/s. Chemical and XPS analysis results suggest that due to the instability of the direct reduction product V(OH)2, the obtained deposits after reducing electrolysis are mixed-valence (+3/+4) vanadium compounds with an empirical compound formula of VO1.87·1.38H2O. X-ray diffraction and TGA/DSC analysis results further confirm that the collected reducing electrolysis products are amorphous hydrated vanadium compounds. [Copyright &y& Elsevier]