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Solid–water interfaces are crucial for clean water, conventional and renewable energy, and effective nuclear waste management. However, reflecting the complexity of reactive interfaces in continuum-scale models is a challenge, leading to oversimplified representations that often fail to predict real-world behavior. This is because these models use fixed parameters derived by averaging across a wide physicochemical range observed at the molecular scale. Recent studies have revealed the stochastic nature of molecular-level surface sites that define a variety of reaction mechanisms, rates, and products even across a single surface. To bridge the molecular knowledge and predictive continuum-scale models, we propose to represent surface properties with probability distributions rather than with discrete constant values derived by averaging across a heterogeneous surface. This conceptual shift in continuum-scale modeling requires exponentially rising computational power. By incorporating our molecular-scale understanding of solid–water interfaces into continuum-scale models we can pave the way for next generation critical technologies and novel environmental solutions. Chemistry at solid-water interfaces is crucial for all aspects of human life. Here, authors propose to use a probability-based paradigm for formalizing chemical reactions at solid-water interfaces in continuum scale models. [ABSTRACT FROM AUTHOR]

Solid–water interfaces are crucial for clean water, conventional and renewable energy, and effective nuclear waste management. However, reflecting the complexity of reactive interfaces in continuum-scale models is a challenge, leading to oversimplified representations that often fail to predict real-world behavior. This is because these models use fixed parameters derived by averaging across a wide physicochemical range observed at the molecular scale. Recent studies have revealed the stochastic nature of molecular-level surface sites that define a variety of reaction mechanisms, rates, and products even across a single surface. To bridge the molecular knowledge and predictive continuum-scale models, we propose to represent surface properties with probability distributions rather than with discrete constant values derived by averaging across a heterogeneous surface. This conceptual shift in continuum-scale modeling requires exponentially rising computational power. By incorporating our molecular-scale understanding of solid–water interfaces into continuum-scale models we can pave the way for next generation critical technologies and novel environmental solutions. Chemistry at solid-water interfaces is crucial for all aspects of human life. Here, authors propose to use a probability-based paradigm for formalizing chemical reactions at solid-water interfaces in continuum scale models. [ABSTRACT FROM AUTHOR]

Many challenges related to carbon-dioxide ( CO 2 ) sequestration in subsurface rock are linked to the injection of fluids through induced or existing fracture networks and how these fluids are altered through geochemical interactions. Here, we demonstrate that fluid mixing and carbonate mineral distributions in fractures are controlled by gravity-driven chemical dynamics. Using optical imaging and numerical simulations, we show that a density contrast between two miscible fluids causes the formation of a low-density fluid runlet that increases in areal extent as the fracture inclination decreases from 90 ∘ (vertical fracture plane) to 30 ∘ . The runlet is sustained over time and the stability of the runlet is controlled by the gravity-driven formation of 3D vortices that arise in a laminar flow regime. When homogeneous precipitation was induced, calcium carbonate covered the entire surface for horizontal fractures (0 ∘ ). However, for fracture inclinations greater than 10 ∘ , the runlet formation limited the areal extent of the precipitation to less than 15% of the fracture surface. These insights suggest that the ability to sequester CO 2 through mineralization along fractures will depend on the fracture orientation relative to gravity, with horizontal fractures more likely to seal uniformly. [ABSTRACT FROM AUTHOR]

Background/Aims: Epstein-Barr virus (EBV) and Helicobacter pylori (HP) coinfection may synergistically induce severe inflammatory responses in the stomach tissue, increasing the risk of developing gastric cancer. We aimed to analyze the effect of EBV and HP coinfection on the clinicopathologic features and prognosis of gastric cancer, as well as to evaluate the role of EBV infection in non-gastric carcinoma with lymphoid stroma (non-GCLS). Methods: Overall, 956 patients who underwent surgery for gastric cancer between September 2014 and August 2015 were eligible and divided into groups, according to GCLS morphology, EBV infection, and HP infection. Clinicopathologic characteristics and oncologic outcomes were analyzed retrospectively. Results: EBV and HP coinfection was significantly associated with male sex, proximal location, GCLS morphology, and equivocal p53 expression (p<0.001). Multivariate analysis revealed that EBV infection alone (hazard ratio [HR], 0.362; 95% CI, 0.131 to 0.996; p=0.049) and lower third location (HR, 0.624; 95% CI, 0.413 to 0.943; p=0.025) were inversely correlated with overall survival. During median follow-up period of 72 months, overall survival rate was not significantly different between the EBV and HP coinfection group and others (97.6% vs 86.8%, log-rank p=0.144). In non-GCLS patients (n=920), overall survival rate was not significantly different between the EBV infection group and others (96.9% vs 86.4%, log-rank p=0.126). Conclusions: EBV and HP coinfection is not an independent prognostic factor for gastric cancer. EBV infection status, regardless of HP infection, affects the clinicopathologic features of all types of gastric cancer. However, it does not lead to a significant difference in overall survival of nonGCLS patients. [ABSTRACT FROM AUTHOR]

Engineered cyanobacterium Synechococcus elongatus can use light and CO2 to produce sucrose, making it a promising candidate for use in co-cultures with heterotrophic workhorses. However, this process is challenged by the mutual stresses generated from the multispecies microbial culture. Here we demonstrate an ecosystem where S. elongatus is freely grown in a photo-bioreactor (PBR) containing an engineered heterotrophic workhorse (either β-carotene-producing Yarrowia lipolytica or indigoidine-producing Pseudomonas putida) encapsulated in calcium-alginate hydrogel beads. The encapsulation prevents growth interference, allowing the cyanobacterial culture to produce high sucrose concentrations enabling the production of indigoidine and β-carotene in the heterotroph. Our experimental PBRs yielded an indigoidine titer of 7.5 g/L hydrogel and a β-carotene titer of 1.3 g/L hydrogel, amounts 15–22-fold higher than in a comparable co-culture without encapsulation. Moreover, 13C-metabolite analysis and protein overexpression tests indicated that the hydrogel beads provided a favorable microenvironment where the cell metabolism inside the hydrogel was comparable to that in a free culture. Finally, the heterotroph-containing hydrogels were easily harvested and dissolved by EDTA for product recovery, while the cyanobacterial culture itself could be reused for the next batch of immobilized heterotrophs. This co-cultivation and hydrogel encapsulation system is a successful demonstration of bioprocess optimization under photobioreactor conditions. [ABSTRACT FROM AUTHOR]

All solid materials are created via nucleation. In this evolutionary process, nuclei form in solution or at interfaces, expand by monomeric growth and oriented attachment, and undergo phase transformation. Nucleation determines the location and size of nuclei, whereas growth controls the size, shape, and aggregation of newly formed nanoparticles. These physical properties of nanoparticles can affect their functionalities, reactivities, and porosities, as well as their fate and transport. Recent advances in nanoscale analytical technologies allow in situ real-time observations, enabling us to uncover the molecular nature of nuclei and the critical controlling factors for nucleation and growth. Although a single theory cannot yet fully explain such evolving processes, we have started to better understand how both classical andnonclassical theories can work together, and we have begun to recognize the importance of connecting these theories. This review discusses the recent convergence of knowledge about the nucleation and growth of nanoparticles. [ABSTRACT FROM AUTHOR]

Solar-driven desalination, which involves the conversion of solar energy to heat for freshwater generation, has been recognized as an attractive and sustainable desalination technology to alleviate freshwater shortage. In particular, photothermally driven membrane distillation (PMD) is a highly promising solar-driven desalination technology, especially in remote regions and disaster-struck communities, where no power infrastructure or waste heat from industrial plants is available. MXene, more specifically Ti3C2Tx, with excellent photothermal properties, easy processability, and electrical conductivity offers a great opportunity for realizing highly efficient, stable and multifunctional PMD membranes. Herein, we realize a MXene composite aerogel comprised of hydroxyapatite nanowires and poly(vinyl alcohol) with high thermal efficiency (61%) and water flux (0.72 kg m−2 h−1) under 0.8 sun irradiation (0.8 kW m−2), representing the first validation of highly efficient MXene-based PMD systems in treating ambient saline water. Owing to the strong interfacial interaction (i.e., hydrogen bonding) between the building blocks, the MXene composite aerogel with high porosity (up to 91%) exhibited excellent mechanical stability. This highly interconnected porous network offers low resistance to vapor transport and low thermal conductivity, which minimizes conductive heat transfer across the aerogel, thus maximizing the thermal efficiency. Furthermore, the outstanding bactericidal activity induced by solar irradiation or electric potential makes the MXene composite aerogel a highly attractive candidate for PMD in the real world. [ABSTRACT FROM AUTHOR]

Manmade high-performance polymers are typically non-biodegradable and derived from petroleum feedstock through energy intensive processes involving toxic solvents and byproducts. While engineered microbes have been used for renewable production of many small molecules, direct microbial synthesis of high-performance polymeric materials remains a major challenge. Here we engineer microbial production of megadalton muscle titin polymers yielding high-performance fibers that not only recapture highly desirable properties of natural titin (i.e., high damping capacity and mechanical recovery) but also exhibit high strength, toughness, and damping energy — outperforming many synthetic and natural polymers. Structural analyses and molecular modeling suggest these properties derive from unique inter-chain crystallization of folded immunoglobulin-like domains that resists inter-chain slippage while permitting intra-chain unfolding. These fibers have potential applications in areas from biomedicine to textiles, and the developed approach, coupled with the structure-function insights, promises to accelerate further innovation in microbial production of high-performance materials. Here, the authors engineer microbial production of muscle titin fibers with highly desirable mechanical properties and provide structural analyses that explain the molecular mechanisms underlying high performance of this polymer with potential uses in biomedicine and textile industries, among others. [ABSTRACT FROM AUTHOR]

In developing countries and resource-limited regions, where no power infrastructure or waste heat from industrial plants is available, photothermal-driven membrane distillation (PMD) has been recognized as an attractive and sustainable technology for freshwater generation. PMD enables easy water collection, inherent fouling resistance, low-pressure operation, and high-salinity water treatment. Hydroxyapatite (HA) nanowires with excellent mechanical flexibility owing to their high aspect ratio, low thermal conductivity, easy surface modification and scalable production offer great potential for highly efficient membrane distillation. Herein, we demonstrate that the environmentally benign HA nanowire-based bilayered film offers the highest photothermal efficiency (62%) and water flux (0.89 kg m−2 h−1) with 1 sun irradiation (1 kW m−2), among the existing PMD systems without auxiliary heating or multilayer heat recovery reported so far. The hierarchical porous structure formed by the remarkably flexible and intertwined HA nanowires allows low resistance to vapor transport, which is critical for high water flux. Simultaneously, the low thermal conductivity of the thermal insulator layer comprised of HA nanowires prevents conductive heat transfer across the membrane, which significantly enhances the thermal efficiency of the membrane. The completely biocompatible, scalable, and thermally engineered bilayered film demonstrated here achieves highly efficient PMD. [ABSTRACT FROM AUTHOR]

To alleviate the scarcity of clean water, solar steam generation, which utilizes the green and abundant resources of Earth, has attracted considerable attention and been recognized as a sustainable technology to purify seawater and wastewater. Within the past five to seven years, building on remarkable advances in the synthesis of nanoscale photothermal materials, significant progress has been made in the design and fabrication of solar evaporators. Here, we comprehensively review the materials and structures of the three key components of solar evaporators: solar absorbers, substrates (i.e., support layers), and water collectors towards efficient harvesting of sunlight, thermal management, water transportation, interfacial evaporation, and collection. In particular, we discuss the design principles of water collectors for solar-driven evaporation, which are in the early stages of development at present. Furthermore, bio-inspired water collectors provide exciting opportunities for the design and realization of efficient water harvesting from solar steam. Finally, we introduce photothermal-enhanced membrane distillation (PMD), a promising alternative technique involving solar-driven interfacial evaporation for producing clean water. PMD combines solar energy and membrane distillation, which facilitates efficient water purification and collection. In this review, we discuss the design guidelines and recent development of this photothermal-enhanced water purification. This review provides useful insights into the material choice and structure optimization to realize enhanced solar evaporators towards freshwater generation. [ABSTRACT FROM AUTHOR]

Background: To evaluate the clinical feasibility of radiofrequency ablation (RFA) of benign thyroid nodules along with cytomorphological alteration, and any malignant transformation through biopsy. Methods: The data were retrospectively collected between April 2008 and June 2013 and core needle biopsy (CNB) was performed on 16 benign thyroid nodules previously treated using RFA. The parameters of the patients were compared, between the time of enrollment and the last follow-up examination, using linear mixed model statistical analysis. Results: No atypical cells or neoplastic transformation were detected in the undertreated peripheral portion of treated benign nodules on the CNB specimen. RFA altered neither the thyroid capsule nor the thyroid tissue adjacent to the treated area. On histopathological examinations, we observed 81.2% acellular hyalinization, which was the most common finding. After a mean follow-up period of over 5 years, the mean volume of thyroid nodule had decreased to 6.4±4.2 mL, with a reduction rate of 81.3%±5.8% (P<0.0001). Conclusion: RFA is a technically feasible treatment method for benign thyroid nodules, with no carcinogenic effect or tissue damage of the normal thyroid tissue adjacent to the RFA-treated zone. [ABSTRACT FROM AUTHOR]

To ensure the safety and efficiency of engineered subsurface operations, it is vital to understand impacts of aqueous chemistries on brine–mineral interactions in subsurface environments. In this study, using biotite as a model phyllosilicate, we investigated the effects of sulfate on its interfacial reactions under subsurface relevant conditions (95 °C and 102 atm of CO2). By making monodentate mononuclear complexes with biotite surface sites, 50 mM sulfate enhanced biotite dissolution by 40% compared to that without sulfate. However, sulfate at lower concentrations than 50 mM did not obviously affect biotite dissolution. In addition, sulfate did not impact secondary mineral precipitation. However, even without any discernible surface morphological change, sulfate adsorption made biotite surfaces more hydrophilic. To provide a more comprehensive perspective on environmentally-abundant ligands, we further comparatively examined the effects of various inorganic (e.g., sulfate and phosphate) and organic ligands (e.g., acetate, oxalate, and phosphonates) on biotite interfacial interactions and assessed their impacts on physico-chemical properties. We found that the presence of phosphate and phosphonates significantly promoted precipitation of Fe- and Al-bearing secondary minerals, but sulfate, acetate, and oxalate did not. Biotite surface wettability was also altered as a result of changes in biotite surface functional groups and surface charges by ligand adsorption: sulfate, oxalate, phosphate, and phosphonate made biotite more hydrophilic, while acetate made it less hydrophilic. This study provides useful new insights into the effects of brine chemistries on brine–mineral interactions, enabling safer and more efficient engineered subsurface operations. [ABSTRACT FROM AUTHOR]

Graph: Professor Donald Sparks This Special Issue of I Geochemical Transactions i is dedicated to Professor Donald L. Sparks, the S. Hallock du Pont Chair in the Department of Plant and Soil Sciences, and the Director of the Delaware Environmental Institute, at the University of Delaware (UD), in celebration and honor of his life-long research interests and achievements in environmental soil chemistry. Then, several articles by Sowers et al. [[5]], Stuckey et al. [[6]], Sundman et al. [[7]], and Zhu et al. [[8]] discuss how iron and manganese (hydr)oxides interact with organic compounds undergoing redox reactions and dissolution. Nickel, zinc, and copper in soils are trace transition metals and critical nutrients as well. [Extracted from the article]

Solar-driven membrane distillation using photothermal membranes is of considerable interest for future water desalination systems. However, the low energy efficiency, complex synthesis, and instability of current photothermal materials hinder their further development and practicability. In this study, for the first time, we demonstrate a simple, stable, and scalable polydopamine (PDA)-coated polyvinylidene fluoride (PVDF) membrane for highly efficient solar-driven membrane distillation (MD). Our membrane shows the best energy efficiency among existing photothermal MD membranes (45%) and the highest water flux (0.49 kg m−2 h−1) using a direct contact membrane distillation (DCMD) system under 0.75 kW m−2 solar irradiation. Such a performance was facilitated by the PDA coating, whose broad light absorption and outstanding photothermal conversion properties enable higher transmembrane temperature and increased driving force for vapor transport. In addition, the excellent hydrophobicity achieved by fluoro-silanization gives the membrane great wetting resistance and high salt rejection. More importantly, the robustness of our membrane, stemming from the excellent underwater adhesion of the PDA, makes the composite membrane an outstanding candidate for real-world applications. [ABSTRACT FROM AUTHOR]

Li metal batteries can store at least ten times more energy than currently existing Li-ion batteries. However, during routine charging and discharging, Li dendrites grow on the Li metal electrode, which can lead to capacity loss by the consumption of Li salt at the surface of the Li dendrites, and be a safety hazard resulting from the potential for short-circuits. Although past efforts have provided useful information about the morphology and surface area of Li dendrite formation at the microscale, a nanoscale understanding of nucleation and growth of Li nanoparticle electrodeposition is still elusive. In this study, using a new electrochemical cell for transmission mode grazing incidence small angle X-ray scattering, we obtained, for the first time, the primary nucleus size of Li nanoparticles, their size evolution and their fractal structures at various current densities and in real-time. The measured average radius of gyration, Rg, at current densities of 0.1, 0.5, and 2.0 mA cm−2 is 5.4 ± 0.4, 4.5 ± 0.3, and 3.5 ± 0.3 nm, respectively. This variation in size with current density is noteworthy when recognizing that the surface area-to-volume ratio of the Li nanoparticles is 3.7 times higher at 2.0 mA cm−2 than at 0.1 mA cm−2. We also compared a hierarchical fractal structure of Li particles from the nanometer to micrometer scale. Our findings illuminate the role of overpotential in the reactive surface area of Li dendrites at the nanoscale, and provide a novel research platform for suppressing Li dendrite formation in Li metal battery systems. [ABSTRACT FROM AUTHOR]

Global phosphorus (P) should be managed more sustainably to secure food, energy, and water for a growing population. Despite the abundance of calcium in most environments, we have not fully utilized its thermodynamic stability to form calcium phosphate minerals (CaP) for aqueous P management. In this study, we showed that the energy barriers to CaP nucleation can be reduced by seeding reactive CaP nuclei in calcium alginate beads. The CaP nucleation kinetics enhanced by seeds effectively immobilized aqueous P into the macroscale beads, which can be reused as a slow-release fertilizer. Given that more developed CaP crystalline seeds have a lower solubility than does an amorphous structure, equilibrium P concentration was regulated successfully by the seed crystallinity during both the removal and release processes. A simultaneous seed nucleation during alginate gelation enabled control of the degree of the seeds’ crystallization without using any hazardous substance or additional energy input. Poorly crystalline hydroxyapatite CaP seeds effectively decreased aqueous P concentration from 200 to 22.7 μM within one day at a final pH 7.2 (96.4 mg P g−1 dry seed). After P recovery, the beads were moved to a P-deficient environment to be evaluated as a slow-release fertilizer. Utilizing the thermodynamic stability of CaP at neutral pH, this approach highlights a potential application of naturally abundant biomaterials for sustainable P management. [ABSTRACT FROM AUTHOR]

Brine–mica interfacial interactions affect both the caprock integrity and the fate and transport of reactive fluids at deep subsurface sites. Phosphate naturally exists at low concentration in subsurface brines, and its concentration can be increased significantly during energy-related engineered subsurface processes. However, our understanding of the influence of phosphate on brine–mica interactions is limited, especially under subsurface conditions. Here, biotite dissolution experiments were conducted without and with phosphate (0.1, 1, and 10 mM) at 95 °C and 102 atm CO2. Compared to the control, 0.1 mM, and 1 mM phosphate systems, biotite dissolution was four times higher with 10 mM phosphate. Despite the dissolution differences, in all the phosphate systems, phosphate interacted with Al and Fe sites in biotite, forming surface complexation and precipitating as Fe- or Al-bearing minerals on surfaces and in solutions. Consequently, aqueous Fe and Al concentrations became lower with phosphate than in the control experiments. In addition, the biotite basal surfaces became more hydrophilic after reaction with phosphate, even at 0.1 mM, mainly from phosphate adsorption. This study offers new information on how phosphate-containing brine interacts with caprocks and on the consequent wettability changes, results that can benefit current and future energy-related subsurface engineering processes. [ABSTRACT FROM AUTHOR]

Solar steam generation by heat localization is considered to be a highly efficient, sustainable way to alleviate water shortage in resource-limited regions. However, most of the interfacial photothermal evaporators demonstrated so far involve non-biodegradable nanoscale materials, which can quickly pose a significant threat to the environment and ecosystems, especially marine ecosystems, after their disposal. For the first time, a flexible, scalable and, more importantly, completely biodegradable photothermal evaporator for highly efficient solar steam generation is introduced. The bilayered evaporator is comprised of bacterial nanocellulose (BNC) densely loaded with polydopamine (PDA) particles during its growth. The biodegradable foam introduced here exhibits large light absorption and photothermal conversion, heat localization, and efficient water transportation, leading to an excellent solar steam generation performance under one sun (efficiency of ∼78%). The novel material and scalable process demonstrated here can be a sustainable solution to alleviate the global water crisis. [ABSTRACT FROM AUTHOR]

Although metastasis from cutaneous malignant melanoma to the small intestine is not uncommon, primary small bowel melanoma (SBM) is extremely rare. This case report describes a rare case of primary SBM, diagnosed by single-balloon enteroscopy. A 74-yearold man presented with recurrent melena. Upper endoscopy and colonoscopy were unremarkable. Abdominal computed tomography (CT) revealed an ileal mass with ileo-ileal intussusception. Subsequent single-balloon enteroscopy identified an ileal tumor, which was histologically diagnosed as melanoma. Extensive clinical examination did not reveal any primary cutaneous lesions. To the best of our knowledge, this is the first case of primary SBM in South Korea. [ABSTRACT FROM AUTHOR]

This study introduces a new and previously unconsidered fast abiotic formation of Mn(iv) oxides. We report photochemically assisted fast abiotic oxidation of Mn2+ (aq) to Mn(iv) (s) by superoxide radicals generated from nitrate photolysis. This photochemical pathway generates randomly stacked layered birnessite (δ-MnO2) nanosheets. [ABSTRACT FROM AUTHOR]

Mineral scaling persists in many water treatment processes. More specifically, it can significantly reduce the efficacy of aromatic polyamide (PA) membranes during reverse osmosis (RO) water treatment. Previous studies have integrated hydrophilic materials, such as polyethylene glycol (PEG), onto RO membranes to combat scaling from generally hydrophobic feed water constituents; however, there are still outstanding knowledge gaps regarding the interplay of the modified membrane surface chemistry and the water chemistry in complex RO feed waters. In this work, we have investigated the mechanisms of hydrophilic PEG-grafted PA membranes in reducing mineral scaling from calcium carbonate (CaCO3) and calcium sulfate (CaSO4) in the presence of humic acid (HA). Based on surface and solution analyses, we found that colloidal formation was significantly reduced on PA–PEG surfaces in systems without HA. When HA was introduced, CaCO3 scaling was reduced on both virgin and PA–PEG membrane surfaces; while, interestingly, synergistic PEG–HA–CaSO4 interactions increased CaSO4 colloidal formation on PA–PEG membranes. Promoted CaSO4 formation results from a high negative surface charge near the PEG-modified membrane surface when HA and SO42− are present, attracting more Ca2+ to form CaSO4. The results of this work provide new information about colloidal formation at water–membrane interfaces for designing better PEG and PEG-based scale-resistant desalination membranes. [ABSTRACT FROM AUTHOR]

Pseudomembranous colitis (PMC) is a nosocomial and opportunistic infection caused by Clostridium difficile. PMC is related to the use of antibiotics leading to intestinal dysbiosis and an overgrowth of C. difficile. Metronidazole or vancomycin is considered to be the standard therapy for the management of PMC. However, PMC has a 15%-30% recurrence rate and can be refractory to standard treatments, resulting in morbidity and mortality. Here we describe a patient who experienced refractory PMC who was treated with fecal microbiota transplantation. A 69-year-old woman was admitted to the hospital with consistent abdominal pain and diarrhea, which had been present for 5 months. She was diagnosed with PMC by colonoscopy and tested positive for C. difficile toxin. Even though she took metronidazole for 10 days, followed by vancomycin for 4 weeks, her symptoms did not improve. Because of her recurrent and refractory symptoms, we decided to perform fecal microbiota transplantation. Fifty grams of fresh feces from a donor were obtained on the day of the procedure, mixed with 500 mL of normal saline, and then filtered. The filtered solution was administered to the patient's colon using a colonoscope. After the procedure, her symptoms rapidly improved and a follow-up colonoscopy showed that the PMC had resolved without recurrence. [ABSTRACT FROM AUTHOR]

Background: Metformin is considered the first choice oral treatment for type 2 diabetes patients in the absence of contraindications. Rarely, life-threatening complications associated with metformin treatment are seen in some patients with underlying diseases. The aim of this study was to further investigate the clinical profiles and risk factors for metformin-associated lactic acidosis (MALA) and the treatment modalities according to survival. Methods: To identify MALA, we performed a retrospective study in seven diabetic patients who were taking metformin and had been diagnosed with lactic acidosis at Inha University Hospital between 1995 and 2012. For each patient, we recorded the age, sex, daily metformin dosage, laboratory test results, admission diagnosis, and risk factors. Also, concurrent conditions, treatment modalities, and outcomes were evaluated. Results: Six patients had risk factors for lactic acidosis before admission. All patients had renal impairment on admission as a precipitating risk factor. Five patients survived and two patients died despite early renal replacement therapy. Older patients tended to have a poorer prognosis. Conclusion: Renal function must be monitored in elderly type 2 diabetes mellitus patients with underlying diseases and conditions causing renal impairment who begin metformin treatment. Accurate recognition of MALA and initiation of renal replacement are essential for treatment. [ABSTRACT FROM AUTHOR]

A quantitative description of how the bulk properties of aluminosilicates affect their dissolution kinetics is important in helping people understand the regulation of atmospheric CO2 concentration by silicate weathering and predict the fate and transport of geologically sequestered CO2 through brine–rock interactions. In this study, we employed a structure model based on the C1̅ space group to illustrate how differences in crystallographic properties of aluminosilicates, such as T–O (Tetrahedral site–Oxygen) bond length and Al/Si ordering, can result in quantifiable variations in mineral dissolution rates. The dissolution rates of plagioclases were measured under representative geologic carbon sequestration (GCS) conditions (90 °C, 100 atm of CO2, 1.0 M NaCl, and pH ∼ 3.1), and used to validate the model. We found that the logarithm of the characteristic time of the breakdown of Al–O–Si linkages in plagioclases follows a good linear relation with the mineral's aluminum content (nAl). The Si release rates of plagioclases can be calculated based on an assumption of dissolution congruency or on the regularity of Al/Si distribution in the constituent tetrahedra of the mineral. We further extended the application of our approach to scenarios where dissolution incongruency arises because of different linkage reactivities in the solid matrix, and compared the model predictions with published data. The application of our results enables a significant reduction of experimental work for determining the dissolution rates of structurally related aluminosilicates, given a reaction environment. [ABSTRACT FROM AUTHOR]

Managed aquifer recharge (MAR) has potential for addressing deficits in water supplies worldwide. It is also widely used for preventing saltwater intrusion, maintaining the groundwater table, and augmenting ecological stream flows, among many other beneficial environmental applications. However, field MAR sites have experienced arsenic mobilization from aquifer formation minerals due to induced changes in groundwater chemistry. To address this environmental concern, it is crucial to understand the potential sources and sinks impacting arsenic mobilization. This paper outlines important mineral–water interactions that can occur at MAR sites. Detailed information on minerals of concern, physiochemical processes for arsenic mobilization or attenuation, and the potential impact of microbial activity and hydrology on these processes is provided. Based on these mineral–water interactions, guidelines for predicting arsenic mobility are presented, and recommendations are made concerning MAR site monitoring. The review emphasizes important aspects in correlating interfacial reactions to reactive transport modeling and elucidating future challenges, a first step toward developing safer and more sustainable MAR operations. [ABSTRACT FROM AUTHOR]

Nucleation occurs widely in materials synthesis and natural environments. However, in the nucleation rate equation, values for the apparent activation energy (Ea) and the pre-exponential kinetic factor (A) are thus far unknown because real-time nanoscale observations are difficult to perform. Here we experimentally determine Ea and A using heterogeneous calcium carbonate nucleation on quartz as a model system. Nucleation rates are measured with in situ grazing incidence small-angle X-ray scattering and ex situ atomic force microscopy, and the experiments are conducted with a fixed supersaturation of IAP/Ksp(calc) = 101.65 at 12, 25, and 31 °C. Ea is calculated as 45 ± 7 kJ mol−1, and A is 1012.0 ± 1.1 nuclei μm−2 min−1, or 102.9 ± 1.3 mol m−2 min−1. Increasing the temperature shortens the induction time, but does not change nucleus sizes. These parameter values are critical for predicting and controlling the nucleation of materials. Nucleation is a ubiquitous process, but key kinetic parameters governing the rate of nucleation can be difficult to measure. Here a combination of in situ GISAXS and ex situ AFM measurements allows experimental determination of the activation energy and pre-exponential kinetic factor for heterogeneous CaCO3 nucleation on quartz. [ABSTRACT FROM AUTHOR]