Background/Objectives: Rho-associated protein kinase inhibitors reduce intraocular pressure (IOP) by enhancing aqueous humor outflow through the trabecular meshwork-Schlemm's canal pathway. However, it remains unclear whether the fixed-dose combination of ripasudil hydrochloride hydrate and brimonidine tartrate (GLAALPHA) enhances conventional aqueous outflow in vivo. Methods: This single-center randomized clinical trial included healthy adult volunteers who received GLAALPHA, a brimonidine tartrate-brinzolamide fixed-dose combination (Ailamide), or brimonidine tartrate monotherapy (Aiphagan) in a crossover sequence. The aqueous column width in the episcleral veins was assessed at baseline and at 2 h (primary outcome) and 8 h using hemoglobin video imaging. Results: Among 24 participants, analyses included 23 GLAALPHA-treated eyes, 21 Ailamide-treated eyes, and 22 Aiphagan-treated eyes. Two hours after instillation, the aqueous column width significantly increased from baseline only in the GLAALPHA group (p = 0.002). The percent increase in the aqueous column width at 2 h was significantly greater with GLAALPHA than with Ailamide (p = 0.039) and not significantly different between GLAALPHA and Aiphagan (p = 0.114). At 8 h, the aqueous column width did not differ from the baseline in any groups. Conclusions: In healthy adult eyes, GLAALPHA significantly increased the aqueous column width in the episcleral veins 2 h after instillation, indicating enhanced conventional aqueous outflow. These findings provide evidence that GLAALPHA promotes trabecular outflow beyond the effects of brimonidine tartrate-containing comparators and offer mechanistic insights into its action.
Subanalysis of a prospective, multicenter, observational study at 72 US adult, pediatric, and mixed trauma centers. We investigated trauma-related risk factors and patient-level factors associated with multiregional spinal column injury, defined as cervical spine injury (CSI) requiring treatment and thoracolumbar injury (TLI). Traumatic spinal injury causes morbidity and mortality in pediatric patients. Injuries to multiple spinal column regions require early identification and thoughtful management. All children <18 years undergoing cervical spine evaluation after blunt multisystem trauma were prospectively identified and enrolled. Clinically significant CSI was defined by cervical spine surgery or halo placement. TLI incidence and management was recorded. The primary outcome was multiregional spinal column injury (CSI+TLI). Of 19,651 enrolled patients, 1484 children (7.5%) experienced a TLI, 159 (0.81%) had CSI requiring treatment, and 30 (0.15%) had CSI+TLI. Multivariate analysis revealed that the trauma-related factors mechanism of injury (P<0.001), rib fractures (odds ratio (OR) 2.8 [2.3-3.4]), hemothorax/pneumothorax (OR 2.0 [1.7-2.4]), bowel injury (OR 4.0 [2.9-5.4]), pelvic fracture (OR 1.5 [1.2-1.9]), and clinically significant CSI (OR 1.9 [1.2-2.9]) were independently associated with TLI. Of the 159 children with clinically significant CSI, 30 also experienced TLI (19%). Multivariate analysis identified prehospitalization intubation (OR 3.1 [1.1-8.4]) and rib fractures (OR 3.9 [1.2-12.8]) as independent associations with CSI+TLI. Of children with CSI requiring treatment, 19% experienced TLI. MOI and various trauma-related injuries were independently associated with TLI, whereas prehospitalization intubation and rib fractures were independent risk factors for CSI+TLI. These factors should trigger screening for multiregional spinal column injury in pediatric trauma patients. Furthermore, if there is known TLI, the cervical spine should be evaluated, and if there is significant CSI, then dedicated imaging of the thoracic and lumbar spine is indicated. III.
L-shaped steel-reinforced concrete (SRC) columns are commonly used as edge and corner members in bridge piers and high-rise buildings. However, systematic experimental evidence on their dynamic behavior and detailing effects under lateral impact remains limited. This study presents a parametric drop-weight impact program on seven SRC columns with built-in L-shaped steel sections. The effects of impact velocity (v), axial compression ratio (n = 0-0.2), and stirrup spacing in the non-densified region (s = 100-200 mm) were examined in terms of damage evolution, impact-response indices (Fmax, Fave, Δmax, Δres, T), and energy absorption efficiency (η = Eab/E). The results show that impact velocity was the dominant parameter governing both response amplitude and damage severity. Increasing v from 7.67 to 9.90 m/s increased Δmax and Δres by 92.6% and 144.3%, respectively, while η increased from 60.7% to 74.6%. Within the investigated range, axial compression improved resistance and suppressed residual deformation. As n increased from 0 to 0.2, Fmax and Fave increased by 17.5% and 30.4%, respectively, whereas Δres decreased by 32.1%. The effect of stirrup spacing on η was non-monotonic. The intermediate spacing (s = 150 mm) yielded the highest energy absorption ratio (60.7%) and the most balanced overall response among the tested cases, rather than representing a definitive optimum. No global buckling of the embedded steel section was observed, and all specimens maintained overall structural integrity under high-energy impact. These results provide experimental evidence for the response assessment and preliminary transverse detailing of asymmetric SRC columns under lateral impact.
To analyze the learning curve of robot-assisted percutaneous placement of acetabular anterior column screws. Between January 2021 and January 2024, 30 patients undergoing robot-assisted percutaneous acetabular anterior column screw placement performed by the same surgeon were enrolled, including 21 males and 9 females, aged from 27 to 65 years old with a mean of (45.2±17.6) years old, with a disease course ranging from 1 to 9 days with a mean of (1.1±5.3) days. According to the chronological order of surgery, the patients were divided into an early group, a middle group, and a late group, with 10 cases in each group. The number of screws graded as excellent, good, and poor was recorded in each group. Fluoroscopy times, screw planning time, guide wire adjustment times, and total operation time were compared among groups. The learning curve was analyzed using curve regression. All procedures was successfully completed in all three groups, without intraoperative or postoperative complications. Postoperative coronal CT showed that in the early group, excellent/good screws were 8/2;in the middle group, excellent/good screws were 9/1;in the late group, excellent/good screws were 9/1. All screws were graded as excellent or good (26/4), without cortical perforation or poor grade screws. There was no significant difference in the proportion of excellent and good screws among the three groups (P>0.05). Fluoroscopy times, screw planning time, guide wire adjustment times, and total operation time:the differences were statistically significant between the early group and the middle group, and between the early group and the late group (P<0.05), while no significant difference was found between the middle group and the late group(P>0.05). Curve regression showed that fluoroscopy times, screw planning time, guide wire adjustment times, and total operation time for robot-assisted percutaneous antegrade anterior column screw placement gradually decreased progressively with increasing surgical experience and reached a plateau after approximately 15 cases. The learning curve of robot-assisted percutaneous acetabular anterior column screw placement is relatively steep, and surgical performance tends to stabilize after about 15 cases.
Launched in April 2023, the Tropospheric Emissions: Monitoring of Pollution (TEMPO), instrument provides for the first time hourly measurements of atmospheric pollutants over most of North America at high spatial resolution (~2 × 4.75 km2). This evaluation of TEMPO's first year demonstrates the capability of total formaldehyde column retrievals (ΩHCHO, version 3) at different locations, seasons, and meteorological conditions. The ΩHCHO product is assessed using 36 ground-based Pandora direct-sun measurements from Pandonia Global Network (PGN) as a reference data set. The 36 PGN sites were chosen for consistency in direct-sun and sky-scan measurement modes. In the first year of operation (Aug 2023-Sep 2024), TEMPO ΩHCHO exhibits moderate to strong agreement at PGN sites in both measurement modes (R 2 = 0.63 to 0.85). TEMPO shows a negligible bias of -2 ± 20% at lower ΩHCHO (<1.0 × 1016 molecule cm-2) and a larger underestimation of -22 ± 5% at higher ΩHCHO (>1.5 × 1016 molecule cm-2). TEMPO clearly captures the seasonal variability of ΩHCHO, with summer values being greatest and winter, spring, and fall values being lower by - 62%, - 45%, and - 29%, respectively. TEMPO shows no consistent bias at any time of day with excellent agreement with Pandora for different meteorological conditions. For all hourly differences between TEMPO and Pandora, 96% fall within 1 × 1016 molecules cm-2. TEMPO provides almost 50% more days with at least one observation compared to observations taken only at 1 p.m., from typical polar-orbiting satellites. These findings confirm the high quality of TEMPO's ΩHCHO measurements under a wide variety of conditions and show great promise for future scientific applications.
Although mass spectrometry (MS) is a powerful analytical technique, it is vulnerable to matrix interference, and it does not distinguish ions with the same m/z (isobaric interference). Therefore, for the past few decades, numerous efforts have been made to enable coupling separation systems with MS. Apart from a set of mainstream hyphenation approaches (such as those using inductively coupled plasma ionization, electron ionization, and electrospray ionization), a number of less conventional ways to couple separation systems with MS have been devised. Extraordinary methods for coupling gas chromatography, liquid chromatography, capillary electrophoresis, thin-layer chromatography, supercritical fluid chromatography, and other unconventional interfaces and ion sources have been disclosed in the literature. Some of these techniques extend the analyte coverage of traditional hyphenated techniques by enabling the detection of less polar compounds. Others speed up analysis or decrease the cost. Another notable trend is the implementation of the so-called ambient ionization techniques for coupling separations with MS.
Lake Kasumigaura, the second-largest lake in Japan, is shallow, well-oxygenated, and eutrophic. Since shallow lakes are hotspots for methane（CH4）emissions, understanding CH4 oxidation - the process that reduces CH4 emissions - is essential. This study examines aerobic CH4 oxidation in Lake Kasumigaura to clarify seasonal fluctuations over six years and the factors that influence it. There was a seasonal dynamic in aerobic CH4 oxidation in Lake Kasumigaura, with the highest rates in autumn and the lowest in spring. The peak values for both the specific CH4 oxidation rate (0.0764 ± 0.04 h-1) and the CH4 consumption rate (14.9 ± 13.3 nM CH4 h-1) occurred in autumn. Moderate activity was recorded in both summer and winter. Using quantitative PCR and Next-Generation Sequencing, it was found that, unlike in other freshwater lakes, Lake Kasumigaura's methanotrophic community is mainly composed of Methylocystis, a Type II methanotroph. Redundancy analysis revealed niche differentiation: Methylocystis (Type II) correlates strongly with TN and NO3-, while Type I methanotrophs are less abundant and more sensitive to dissolved CH4 and water temperature (W.T.). Variations in the dominant methanotrophs (revealed by pmoA gene analyses) in lake water, along with the complex relationships between environmental factors and these communities, highlight the unique biogeochemical properties of Lake Kasumigaura.
A novel enantioselective open-tubular capillary electrochromatography (CEC) column was fabricated by noncovalently immobilizing (+)-diacetyl-L-tartaric anhydride functionalized NH2-MIL-101(Fe) onto the capillary inner wall using polydopamine as an adhesive layer. The coating of the modified capillary was comprehensively characterized through Fourier-transform infrared spectroscopy, powder X-ray diffraction, Brunauer-Emmett-Teller analysis, scanning electron microscopy, energy dispersive X-ray spectroscopy, circular dichroism, and electroosmotic flow measurements. The column's chiral separation ability was assessed by analyzing seven model compounds, comprising four proton pump inhibitors (omeprazole, pantoprazole, lansoprazole, and tenatoprazole) and three fluoroquinolones (ofloxacin, sparfloxacin, and gatifloxacin). Under optimized conditions, baseline resolution (9.68-14.56) of all enantiomers was achieved within 7 min. The column demonstrated excellent reproducibility, with inter-day, intra-day, and column-to-column relative standard deviations ranging from 1.22% to 4.98%. Additionally, molecular docking simulations were conducted using AutoDock Tools to investigate interactions between the stationary phase and analyte enantiomers, with computational results corroborating experimental CEC data.
MEMS hydrophones, as critical sensors for maritime security and underwater information acquisition, have sensitive membrane structures that exhibit insufficient ability to withstand hydrostatic pressure, necessitating an overload-protection design. Based on buckling stability theory, a collaborative optimization method for overload-protection column design was proposed, integrating theoretical analysis, finite-element simulation, and process feasibility. An optimized design scheme for hydrophone overload-protection columns was established by comprehensively considering geometric buckling-resistant design, micro-gap anti-adhesion requirements, minimal impact on sensitivity, and micro/nano-fabrication constraints. The results indicate that intermediate slenderness columns with radii between 5.5 μm and 7.5 μm sufficiently meet both fabrication and operational requirements, effectively providing overload protection. Furthermore, at water depths not exceeding 382 m, the MEMS hydrophone can maintain the integrity of its membrane structure without column buckling.
We propose the Optimal-Transport Gated Echo-State Network (OT-ESN), a two-timescale reservoir that replaces ad hoc inter-module couplings with a principled, mass-conserving transport mechanism on a cortical-sheet geometry. At each step, a slow, exogenous controller computes an entropically regularized optimal-transport plan Π between the previous distribution of column activity (source) and an input-derived "intent" over columns (target), using a geometric cost that encodes anatomical or functional proximity. The resulting plan-doubly stochastic up to prescribed marginals-acts as a bounded, geometry-aware mixer that gates inter-column blocks of the reservoir at the next fast update. This one-step delay ensures that Π is absent from the time-t Jacobian, so with a 1-Lipschitz nonlinearity and fixed leak, the echo-state property collapses to a single spectral-norm inequality on pre-scaled intra- and inter-column operators, yielding a uniform contraction certificate. OT-ESN, thus, achieves interpretable, neuromodulation-like routing of assembly activity while preserving the simplicity of readout-only training. Computationally, Sinkhorn iterations on a J×J kernel provide efficient, smooth control, with the regularization parameter spanning diffuse (diffusion-like) to sharp (path-like) transports without jeopardizing stability. Ergo, via optimal transport, OT-ESN enables long, structured memory and geometry-respecting information flow in a provably stable recurrent substrate.
Hallux valgus (HV) is a complex forefoot deformity influenced by interactions between osseous alignment, ligamentous restraint, and muscle-tendon forces. While the biomechanical role of ligament laxity and bone geometry has been extensively investigated, the contribution of tibialis anterior (TA) tendon insertion variability to medial column mechanics remains insufficiently understood. A patient-specific finite element model of the foot was developed from high-resolution computed tomography data. Five anatomically documented TA distal insertion configurations were modeled, representing different distributions of attachment to the medial cuneiform and first metatarsal base. All simulations were performed under identical boundary and loading conditions representative of the stance phase of gait. Global (full-foot) and local (first bone and first metatarsal) mechanical responses were quantified using total deformation, equivalent von Mises stress, and strain distributions. Marked differences in mechanical behavior were observed across TA insertion types. The metatarsal-dominant configuration (Type 3) demonstrated the highest global and local deformation values (global deformation: 1.0928 mm; first bone deformation: 1.0928 mm) and elevated strain distributions, whereas the medial-dominant configuration (Type 2) showed minimal deformation (global: 0.0727 mm; first bone: 0.0350 mm) but the highest global equivalent von Mises stress (5.7698 MPa). The single-band insertion to the medial cuneiform (Type 5) produced the greatest localized stress in the first bone region (3.8634 MPa). Representative strain maps revealed distinct spatial redistribution patterns within the medial column associated with TA insertion geometry. This patient-specific finite element analysis indicated that distal TA insertion variability alone can substantially modify deformation, stress, and strain patterns within the medial column. These findings suggested that TA insertion anatomy may act as a biomechanical modulator of first-ray mechanics and should be considered in future studies investigating hallux valgus pathomechanics and personalized treatment strategies.
Background/Objectives: Mass spectrometry-based multi-attribute methods (MAM) have the potential to transform therapeutic protein analysis by enabling comprehensive monitoring of multiple quality attributes in a single assay. However, the widespread adoption of MAM is hindered by significant challenges, most notably artificial oxidation during sample preparation and analysis. This report summarizes long-term operational observations and several case studies that substantiate this concern. Methods: A tryptic digest, high-resolution LC-MS MAM workflow was applied to an Fc-fusion protein and multiple antibody-based therapeutics, with a frozen reference standard analyzed in each run for system suitability and longitudinal trending. Oxidation excursions were investigated by comparing laboratories, consumables, LC-MS configurations, and other method parameters. Results: In a seven-year trending record, apparent total methionine oxidation in the Fc-fusion protein reference standard showed an abrupt, sustained increase (up to ~5-fold); the shift was traced to a specific bag of microcentrifuge-tubes used during buffer exchange and resolved after those tubes were discontinued. In an antibody-drug conjugate, observed methionine oxidation was strongly influenced by the sample preparation procedure. In other antibodies, variability of observed methionine oxidation was attributed to on-column oxidation, which produced a broad and noisy peak that interferes with automated peak integration. EDTA flushing reduced this feature, implicating exposure to metal ions. Conclusions: While advances continue to address many MAM challenges, artificial oxidation remains unpredictable and constitutes a major obstacle to robust implementation in regulated QC environments. Enhanced control strategies and further research are urgently needed to ensure reliable therapeutic protein analysis. Such control strategies include consumable qualification and change control, system suitability/trending using a reference standard, metal management across LC flow path/column lifecycle, reduction of trifluoracetic acid (TFA) exposure, data analysis to safeguard excessive on-column oxidation, etc.
With the growing interest in personalized medicine, alternative biological matrices to blood are increasingly explored as sources of diagnostic information. Saliva has emerged as a promising diagnostic matrix due to its non-invasive collection, suitability for home sampling, and minimal requirements for personnel training. Numerous studies have demonstrated the presence of metabolites in saliva that enable disease diagnosis and monitoring. However, the influence of pre-analytical and analytical factors on salivary metabolomics outcomes remains insufficiently characterized. In this study, we investigated factors potentially affecting the number and abundance of detected metabolites in untargeted salivary metabolomics using liquid chromatography coupled with mass spectrometry (LC-MS). The impact of chromatographic column type, extraction protocol, and saliva type (stimulated versus resting) was evaluated. Additionally, the effect of swab type on analyte recovery was assessed. The use of a synthetic swab for saliva collection yielded results most comparable to those obtained without swabs, for both resting and stimulated saliva samples, indicating minimal pre-analytical interference. The greatest metabolite coverage was obtained using ACN:MeOH (1:1, v/v), with a ZIC-HILIC column for polar metabolites and a C18 column for non-polar metabolite separation. These findings demonstrate that swab type, chromatographic column, extraction solvent, and saliva type critically shape metabolite coverage in untargeted salivary metabolomics. Importantly, the distinct metabolic profiles of resting and stimulated saliva suggest that these matrices may provide complementary clinical insights, underscoring the need for saliva type selection tailored to specific diagnostic and biomarker discovery objectives.
Vascular endothelial growth factor (VEGF) is widely used in regenerative medicine and therapeutic research. However, the purification of recombinant VEGF largely relies on affinity chromatography, which requires expensive chromatographic columns, specialized equipment, and multistep processing. These column-based workflows increase operational complexity and cost, particularly for large-scale production. Therefore, the development of an alternative purification strategy to conventional chromatography-based purification for VEGF is needed. In this study, we developed a chromatography-free VEGF purification strategy using an anti-VEGF-scFv-calsequestrin (CSQ) fusion protein that enables calcium-dependent affinity precipitation. The fusion protein retained strong binding affinity for VEGF (Kd = 1.1 nM) while exhibiting rapid and reversible Ca2⁺-dependent polymerization. Upon CaCl₂ addition, the anti-VEGF-scFv-CSQ-VEGF complex rapidly formed aggregates, enabling efficient separation of VEGF from impurities. Using this strategy, VEGF was purified within 30 min with a purity of 94% and a yield of 93%. SEC-HPLC analysis confirmed a purity of 94.3%, and host cell protein contamination was reduced from 1.44 × 104 ppm to 774 ppm. The fusion protein also maintained stable purification performance over five repeated cycles, with VEGF recovery consistently maintained above 85%. These findings demonstrate that the scFv-CSQ fusion protein enables rapid separation of VEGF through calcium-dependent polymerization. This column-free mechanism reduces operational cost and technical complexity, highlighting its potential as an alternative to conventional chromatography-based purification.
Visual behavior depends on the ability to prioritize relevant sensory information while filtering out distractions. Predictable sensory contexts enable more efficient behavior by altering sensory processing. Using laminar neurophysiology in macaque visual cortex measuring population spiking during a feature-based pop-out visual search task, we examined how predictable visual routines influence cortical columnar processing of sensory information. By manipulating predictability through attentional priming, we found improved behavioral performance with predictable stimulus arrays. These behavioral changes were supported by earlier neuronal attentional target selection driven by reduced variability in the sensory response to the predictable target stimulus and more homogeneous feedforward processing dynamics across the cortical column. More effective distractor suppression was driven by adapted feedforward processing of the more frequent distractor stimulus. Taken together, these changes implicate independent mechanisms for target enhancement and distractor suppression. Our results highlight how predictions from experience alter visual columnar processing to optimize attentional selection through streamlining feedforward signaling. Both target enhancement and distractor suppression are independently observable in visual cortex with different profiles of modulation as a function of predictability.Predictions produce stronger, more reliable feedforward responses to attention-capturing targets across the visual cortical layers.Better distractor suppression with stimulus predictability is driven by adapted sensory representations, not top-down inhibition. How do predictions help determine what catches our attention? It is well known that when primates repeatedly perform visuomotor tasks, they become more proficient. Using neural recordings across the layers of the visual cortex, Groot et al. demonstrate that more efficient feedforward processing of sensory information contributes to improved visual behavior under predictable sensory conditions. These findings highlight the crucial role of predictions in proactively shaping sensory representations to facilitate efficient attentive behavior.
This paper analyzes and investigates the acoustic sensitivity of mandrel fiber optic hydrophones (FOHs) with fiber optic layers (FOLs). Sensitivity models for both single-column and push-pull air-backed structures influenced by the FOL were established, and simulations were conducted to compare the theoretical acoustic sensitivity of mandrel structures with and without the FOL. Three sets of single-column FOHs and two sets of push-pull FOHs were fabricated using different materials and tested. The experimental results show that: in the model considering FOL, the deviation between theoretical and measured values for different material mandrel structures is controlled within 1.5 dB; in the model neglecting the FOL, the maximum deviation between theoretical and measured values of the polyurethane single-column probe reaches 29.2 dB, and the maximum deviation between the theoretical and measured values for the polycarbonate push-pull probe reached 4.29 dB. Therefore, this model can more accurately estimate the acoustic sensitivity of mandrel structures with lower Young's modulus, providing guidance and reference for the design of high-sensitivity mandrel FOHs.
Steroids are critical for numerous physiological processes; disruption in their metabolism is associated with numerous endocrine disorders. Steroid quantification is essential to improve the understanding and diagnosis of these pathologies. Historically, urinary steroid profiling has been performed using low-throughput gas chromatography mass spectrometry (GC-MS), providing holistic coverage of steroid classes with low cross-reactivity. Here, we translate our previous GC-MS urinary steroid profile to a liquid chromatography tandem-MS (LC-MS/MS) platform, offering a validated, comprehensive overview of steroid metabolism with comparatively low sample preparation times and increased throughput. Urinary steroids were enzymatically hydrolysed and extracted via C18 solid-phase extraction. Quantification was conducted using a triple quadrupole mass spectrometer. Chromatographic separation of 27 analytes was completed in 16 min using a C18-T3 column. Due to chromatographic co-elution of tetrahydrocortisol and 5α-tetrahydrocortisol, a second injection was required on a BEH-C18 column for their separation. Lower limit of quantification (LLOQ) ranged from 2 to 20 ng/mL, witha ccuracy (bias) ranging from -18.7% to 19.9%, and precision (percentage coefficient of variation [%CV]) ranging from 4.0% to 18.6%. Matrix effects remained within the ideal range <±15% for all steroids. Recovery ranged from 76% to 103%, and intra- and inter-assay imprecision (CV) ranged from 0.8% to 14.9%. In 40 healthy volunteers, most analytes were detected above the LLOQ in over 95% of samples, although tetrahydro-aldosterone (85%), 5-pregenediol (68%), and pregnanetriol-one (59%) demonstrated lower quantification rates. Diurnal and sex-based variations were observed, with excretion levels significantly higher during daytime and in males. This robust, high-throughput LC-MS/MS method facilitates the simultaneous quantification of multiple steroid classes, enhancing its utility for clinical and research applications in endocrine science.
Stormwater runoff is a significant contributor of phosphorus (P) loading to waterbodies around the world. Green stormwater infrastructure (GSI) that uses filtration media, such as bioretention, can effectively retain suspended solids and associated particulate P, but is commonly less effective for soluble P retention. The addition of aluminum-based drinking water treatment residuals (DWTRs) may increase P-sorbing capacity of GSI media, though guidance is needed for material selection and to reduce risk of potential contamination. This study examined the P removal capacities of DWTRs (n=11) from drinking water treatment plants in the New England region (northeastern USA). DWTRs were compared for P-sorption potential using batch isotherm and column experiments and characterized for several material properties as well as arsenic leaching and per and polyfluoroalkyl substances (PFAS) content. Results indicate that P retention capacity of DWTRs is generally high (>1,000 mg P kg-1) but varies by approximately one order of magnitude. Lower DWTR bulk density and greater oxalate-extractable Al + Fe were correlated with greater P retention in column experiments. Our findings also indicate that the potential for significant arsenic leaching is low. PFAS were detected in 36% of DWTRs, often at low levels near the method detection limit, with three DWTRs having higher levels of certain PFAS. The addition of DWTRs to GSI is promising for enhanced soluble P removal on a decadal scale (10-90 years), but additional research on As, PFAS, and other contaminants should be pursued prior to use, especially in areas with known or suspected source water contamination. Achieving effective long-term P removal requires selecting DWTRs with favorable material properties (e.g., drier, lower bulk density, greater oxalate-extractable Al + Fe), and mixture with sand at up to 10% DWTR by volume and potentially higher if proven to not impede hydraulic conductivity. Field monitoring of DWTR-enhanced infrastructure at multiple time points postinstallation (e.g., years 1, 5, 10, 20, and 30) is needed to confirm P removal longevity over expected infrastructure lifespans.
Antiaromatic molecules are known for their intriguing physical properties and high reactivity, which arise from their unique electronic structures. While the properties of individual antiaromatic molecules have been extensively studied, research on their assembled structures is still in the early stages. In this work, we synthesized a hydrogen-bonded organic framework, named Nor-HOF, using a stable antiaromatic molecule, Ni(II) norcorrole, as a building block. Single-crystal X-ray structure analysis revealed that Nor-HOF possesses a one-dimensional columnar structure of infinitely stacked Ni(II) norcorroles with permanent porosity. Theoretical calculations indicated that the norcorroles in Nor-HOF interact through their molecular orbitals while retaining their antiaromaticity. Furthermore, we demonstrated that the oxidation of the norcorrole columns by adsorption of I2 into the pores enhances the electrical conductivity of Nor-HOF by approximately 1000-fold. This work opens a new perspective on exploiting the periodic structure of antiaromatic molecules for the development of advanced functional materials.
Cave mines operating at greater depths are faced with higher draw column heights, typically ranging from several hundred metres to over one kilometre. This results in significantly higher cave stress on the production level, making reliable stress estimation critical for assessing long-term stability. The current approach to estimating cave stresses in the draw column relies on Janssen's equation, developed initially using the Method of Differential Slices (MDS) and based on laboratory observations of corn and bulk solids in storage silos. This article first reviews the MDS and the assumptions used to derive Janssen's equation. The article also discusses how the limitations of the analogues (e.g. corn material and full-to-empty silo condition) used to develop the equation do not represent conditions equivalent to those observed in cave mining (e.g. fragmented rock blocks undergoing fragmentation and no-column to full-column condition as cave propagates). These mechanistic differences may lead to erroneous estimations of cave stresses. While Janssen's equation is a valuable initial tool for estimating cave stresses, practitioners must carefully assess its assumptions and limitations before applying it to engineering designs.