Large Opening Research Articles

Mummy of a juvenile sabre-toothed cat Homotherium latidens from the Upper Pleistocene of Siberia.

The frozen mummy of the large felid cub was found in the Upper Pleistocene permafrost on the Badyarikha River (Indigirka River basin) in the northeast of Yakutia, Russia. The study of the specimen appearance showed its significant differences from a modern lion cub of similar age (three weeks) in the unusual shape of the muzzle with a large mouth opening and small ears, the very massive neck region, the elongated forelimbs, and the dark coat color. Tomographic analysis of the mummy skull revealed the features characteristic of Machairodontinae and of the genus Homotherium. For the first time in the history of paleontology, the appearance of an extinct mammal that has no analogues in the modern fauna has been studied.

The Multi-Functional Use of Large Tree Cavities by Arboreal Vertebrates in a Temperate Broadleaved Forest of Eastern Europe.

Tree cavities offer protected shelters and resources for arboreal vertebrates worldwide. In general, cavities with larger openings are better accessible for predators and are avoided by smaller species for breeding, but can still be attractive for occasional use. The current study explores the diversity of functional use types and species interactions at the largest available tree cavities (entrance width ≥ 10 cm) in a temperate European forest with a low number of large cavity-breeding species. Year-round camera observations at 9 cavities (range 0.7-3.5 years) revealed 34 visiting species of birds and mammals, including non-cavity-breeding species. The top predator threatening other large-cavity users was European pine marten (Martes martes), which regularly visited each cavity year-round, on average every 0.7 months. Tawny owl (Strix aluco) was the only species successfully breeding in cavities, arguably because of its ability to defend the nests. However, other species visited cavities at an average rate of 1.5 visits per day, making predominantly short visits (less than 30 s) interpreted as exploration, searching for food, or inspecting for the presence of owls (mobbing). Making short visits and time segregation with predators was a behavioural strategy to exploit cavities for most species. These results confirm that, similarly to other keystone structures (large arboreal nests, ground burrows, etc.), large tree cavities attract a significant part of the arboreal vertebrate community and enrich their habitats. To sustain these functions in wooded ecosystems, management should provide a surplus of available cavities and diversity of their characteristics even when the apparent number of breeding species is low.

Dynamic behaviour of ultra-high performance concrete beams with rectangular openings subjected to impact loads

To facilitate residents’ needs, contemporary building structures often incorporate prefabricated transverse openings in reinforced concrete (RC) beams to accommodate pipeline installations. However, these openings can potentially impact the load-bearing capacity of the beams, particularly as structures increasingly need to consider dynamic loading effects. The use of ultra-high performance concrete (UHPC) has proven effective in enhancing the dynamic resistance of RC beams with openings. This study employs numerical simulations in ANSYS/LS-DYNA to investigate the dynamic response of UHPC beams with rectangular openings exposed to low-velocity impact. The calibrated Continuous Surface Cap (CSC) model is primarily validated through quasi-static four-point loading tests on UHPC beams with openings. Following this validation, numerical simulations of drop hammer impact are carried out to comprehensively analyse the behaviour of UHPC beams with openings. Furthermore, parametric investigations are performed to evaluate the impact response of UHPC beams with large or small openings, considering various design factors such as opening size, opening position, stirrup quantity and UHPC strength level.

Microclimate of Brown Bear (Ursus arctos L.) Dens and Denning Area.

The aim of this study was to determine the microclimate of brown bear dens depending on their size, their status (active or inactive), and the location of the den. The study included five dens of different sizes and locations in the Velebit Mountains, in the Dinaric Alps. The measurements of air temperature (°C) and relative humidity (%) in dens and the forest stands were carried out over 182 days. The absolute minimum air temperature in inactive dens was between -2.88 °C and -0.38 °C and belonged to the dens with shorter tunnels and without chambers. The exception was inactive den 1, which was situated in a thermophilic forest. No negative absolute minimum air temperatures were recorded in active dens. The absolute minimum air temperatures in the forest stands were lower than in the dens. The relative humidity was significantly higher in all dens than in the forest stands. Dens with a large entrance opening and a short tunnel were strongly influenced by the local microclimate of the forest stand. The greatest temperature difference (den-forest) was between elongated dens with chambers and the associated forest stand, while the smallest temperature differences occurred in dens with a short tunnel, without a chamber, and at the northern exposure. The greatest differences in relative humidity (den-forest) were found in dens with chambers. The den temperatures correlated with the air temperatures in the forest stands.

Stitching of T-deep beams with large openings by CFRP sheets and NSM steel bars

AbstractIn the present study, a comparison has been conducted to investigate the efficiency of stitching using the near-surface mounted steel bars and externally bonded carbon fibers reinforced polymers technique for strengthening the T-deep beams having large opening within the shear spans and with deficient shear reinforcement. Eight specimens with two locations of openings were tested. It was found that stitching of beams by steel bars with openings located flush to the flange yielded improvement in capacity in range (10–39%). Furthermore, Stitching by external bonded carbon sheets yield enhancements in capacity was 96 and 78% for the top location compared to the control specimen and the vertical near-surface mounted stirrups system. The respective values for the bottom location were 62 and 42% respectively.

Medial Joint Opening in the Operated Knee After Unilateral High Tibial Osteotomy: Risk of Osteoarthritis and Future Surgery in the Operated and Nonoperated Knee

Background: High tibial osteotomy (HTO) modifies the mechanics of the affected knee but can also affect the nonoperated knee. However, no research has reported on the prognosis and risk factors related to the nonoperated knee after unilateral HTO. Purpose: To assess the radiological parameters associated with osteoarthritis (OA) progression and the need for surgery in the nonoperated knee after unilateral HTO, with concurrent assessment of the operated knee. Study Design: Case series; Level of evidence, 4. Methods: The medical charts of 197 patients with knee OA who underwent unilateral HTO between March 2007 and December 2020 were retrospectively investigated. Radiological parameters such as the Kellgren-Lawrence grade, weightbearing line ratio, joint line convergence angle (JLCA), and joint line obliquity angle were assessed preoperatively and 1 year postoperatively. Results: The mean follow-up length for the 197 patients was 5.9 ± 3.2 years for the operated knee and 5.5 ± 3.2 years for the nonoperated knee. A smaller postoperative JLCA in the operated knee was a significant risk factor for OA progression (P = .027) and undergoing surgery (P = .006) in the nonoperated knee. Conversely, a larger postoperative JLCA in the operated knee was a significant risk factor for OA progression (P = .014) and conversion to arthroplasty (P = .027) in the operated knee. A postoperative JLCA >1.5° (P < .001) and <3.9° (P < .001) was needed to reduce the risk of undergoing surgery in the nonoperated knee and OA progression in the operated knee, respectively. Additionally, a pre- to postoperative change in the JLCA (ΔJLCA) between −5.6° and −1.7° (P = .021 and P = .004, respectively) was needed to reduce the risk of OA progression in both knees. Conclusion: A large medial joint opening (a small postoperative JLCA) in the operated knee after unilateral HTO was associated with a higher risk of OA progression and surgery in the nonoperated knee. Conversely, a small medial joint opening (a large postoperative JLCA) was associated with a higher risk of OA progression and conversion to arthroplasty in the operated knee. For a balanced medial joint opening, if the postoperative JLCA was between 1.5° and 3.9° or the ΔJLCA was between −5.6° and −1.7°, a favorable prognosis in both knees could be anticipated.

Static and stability analyses of multi-strut type aluminium alloy suspen-dome structure with large opening

By combining the advantages of the multi-strut concept in cable dome structures with aluminum alloy material, a new type of prestressed spatial structure—the multi-strut aluminum alloy suspen-dome with a large opening—has been developed by integrating a lower prestressed support system into an aluminum alloy reticulated shell. The optimal structural configuration was determined by comparing the static, stability, and economic performance of three types of upper chord mesh topologies for this structure. Subsequently, an analysis of the static performance and large-scale parameters affecting the structural stability of the optimal grid topology was conducted. The study explored the influence of structural prestressing, overall shape, and support stiffness—encompassing three categories and seven parameters—on structural stability and material consumption. Additionally, the effects of initial imperfections and load distribution forms on structural stiffness and stability were further examined. Finally, the static properties, stability, and economic indicators of the structure were compared with two other structural systems: the steel suspen-dome and the cable dome. The results indicate that the pentagonal grid topology provides the best structural performance and that the structure is sensitive to cooling effects. Optimal values for key design parameters, such as the rise-span ratio and thickness-span ratio, were identified. Moreover, the economic advantages of the aluminum alloy suspen-dome compensate for its mechanical performance shortcomings compared to the steel suspen-dome. These findings offer innovative solutions and a scientific basis for the selection and stability design of aluminum alloy suspen-dome structures.

The grouting plugging mechanism of layered jointed rock mass considering the time-varying yield stress of grout

Slurry retention in fractures decreases after grouting is completed and the pressure supply is stopped, which affects the grouting sealing effect and prevents or restrains the occurrence of such adverse conditions. Based on the time-varying yield stress of grout, a theoretical analysis model of grouting diffusion decay is established, the decay height variation function and the minimum pressure stabilisation time calculation formula are derived, and the sealing mechanism of a jointed rock mass with multiple joints is studied. Moreover, a 3D visualisation laboratory test device for grouting diffusion decay of a jointed rock mass with layers was developed to analyse the diffusion and decay process of grout with different water-cement (W/C) ratios visually, and the correctness of the theoretical model was verified. The results show that: (1) the W/C ratio of grout should not be greater than 2, otherwise it is difficult for grout to remain in the cracks; (2) a large fissure opening easily spreads grout but is not conducive to the retention of grout; and (3) the time of stable pressure determines the retention rate of the slurry in the crack. When the horizontal crack opening width is 3 mm and the W/C ratio of the slurry is 1, the minimum stable pressure time to achieve a better sealing effect is 810 s. The research results can be used to reasonably plan the grouting time and improve the grouting efficiency to ensure the grouting effect, which is crucial for improving the theoretical system of grouting technology.

Elastic Bands Improve Oral Appliance Treatment Effect on Obstructive Sleep Apnoea: A Randomised Crossover Trial.

Oral appliances (OAs) that limit mouth opening during sleep, such as monobloc appliances, have shown superior treatment effects in subgroups of patients with obstructive sleep apnoea. The application of elastic bands on bibloc appliances may resemble these benefits. The primary objective was to investigate if application of elastic bands to bibloc appliances improves treatment success (> 50% reduction of respiratory event index (REI)), in addition to other subjective variables. Furthermore, we aimed to identify variables predicting the need for elastic bands in OA treatment. Included patients (n = 69) were randomly assigned to OA treatment with or without elastic bands. After 3 weeks, treatment effect was investigated with home respiratory polygraphy and questionnaires. Thereafter, patients changed treatment modality, with identical follow-up regime. Statistical analyses were performed using Student's t-test and Pearson's chi-squared test to investigate differences between the two treatment modalities, and logistic regression analysis was conducted to investigate variables tentatively associated with treatment success. Based on REI, the success rate with OA treatment was in favour of elastic bands (53.9% vs. 34.6%, p = 0.002). Male sex and larger maximum mouth opening were identified as predictors for increased treatment success with elastic bands. The main benefit with elastic bands seemed to be greater reduction of REI when supine. However, patients seem to prefer OA without elastic bands. Elastic bands improved OA treatment effect by reducing the REI in supine position. Patient groups that seemed to benefit from elastic bands in OA treatment were men with large maximum mouth openings.

Scanning electron microscopy and light microscopy of tongue, fingers, toes, nuptial pad, and humeral gland in Sylvirana nigrovittata (Anura: Ranidae)

The micromorphology and histology of anuran skin, particularly in Thai species, remain relatively understudied. Anurans use their tongues for prey capture and their hands and feet for adhesion and mating, suggesting a close relationship between micro-surface features and histological structure. Information on Sylvirana nigrovittata is particularly limited. This study provides a detailed examination of the micro-surface and histological characteristics of the tongue, fingers, toes, nuptial pad, and humeral gland in S. nigrovittata. Specimens collected from Phu Luang Wildlife Sanctuary in Loei province, northeastern Thailand, were studied using scanning electron microscopy (SEM) for micro-surface features and H&amp;E staining for histological details. SEM micrographs revealed that the tongue was cordate-shaped, with about 75% of its surface covered by filiform papillae and 25% by fungiform papillae housing taste buds. Filiform papillae were trapezoidal, averaging 23.88±5.68 µm in width and 38.83±6.57 µm in length, while fungiform papillae were disc-like, averaging 52.95±14.64 µm in width and 66.70±15.88 µm in length. Digital pads on fingers and toes presented prismatic cells, with fingertip cells averaging 7.09±0.97 µm in width and 11.81±1.24 µm in length, and toe cells averaging 8.40±1.37 µm in width and 11.28±1.63 µm in length. Subdigital surfaces were smoother, containing squamous cells with dimensions of 10.65±3.21 µm in width and 21.29±4.35 µm in length. Subarticular tubercles were composed of prismatic cells with hexagonal or pentagonal surfaces, averaging 10.02±2.85 µm in width and 13.08±1.94 µm in length. Nuptial pad displayed cylindrical structures with dome-like tips, averaging 24.01±3.96 µm in width and 21.16±4.37 µm in length, and feature mucous openings. They consisted of a thick keratinized stratified squamous epithelium and a dense dermis with specialized mucous glands. Humeral gland exhibited rough surfaces with squamous cells and microridges, showing both small and large mucous openings, with average cell dimensions of 16.23±1.70 µm in width and 19.11±2.05 µm in length. Histological analysis confirmed that these structures were predominantly composed of keratinized stratified squamous epithelium, with variations in dermal collagen density and mucous gland distribution. This study enhances our understanding of the skin and gland morphology in S. nigrovittata, highlighting on its anatomical and functional adaptations.

Seismic performance of pentagonal type aluminum alloy suspen-dome structure with large opening

Prestressing technology is an effective way to enhance the mechanical properties of space structures. In view of this, a new pentagonal type aluminum alloy suspen-dome structure with large opening is proposed in this paper by introducing the lower cable support system into the aluminium alloy single-layer reticulated shell structure. The seismic performance of this new structure is investigated using time-procedure analysis. Firstly, the effects of rise-span ratio, thickness-span ratio, prestressing level, horizontal radius factor for lower chord nodes and roof loading on the free vibration characteristics of the structure with different supporting stiffness are investigated. The distributions of internal forces and displacements of members of overall structure considering lower support and roof structure only are analyzed. Subsequently, the dynamic response of the structure under seismic combinations of different dimensions and directions is investigated, and reasonable combinations that should be considered for simplified analyses are derived. Furthermore, seismic internal force coefficients are introduced to assess the degree of seismic effects on various types of members. On this basis, parametric analysis of the seismic performance of the structural performance is conducted and quantitative assessment of the sensitivity of the parameters is carried out. Additionally, the free vibration characteristics and dynamic performance of steel and aluminium suspen-dome are compared. The results show that considering the supporting structure weakens the structural stiffness while increasing the structural dynamic response; reasonable values of key parameters in the seismic design of the structure are obtained; and the rise-span ratio and thickness-span ratio are important influencing factors of the seismic performance of the structure. Besides, the internal forces of members in aluminium alloy suspen-dome are less affected by seismic effects than those in steel suspen-dome, and the new structure has good seismic performance.

An Unusual Variant of Mid-penile Hypospadias with Intact Prepuce and Patulous Urethra - Addition of a Drop to the Sea of Hypospadias Variants.

Hypospadias is one of the most common and extensively studied pathology of paediatric surgery. Although a plethora of research articles describing hypospadias and its variants exist, new variants are often encountered and they never cease to surprise us. We, in our case, are trying to add a drop to the sea of variants of hypospadias. A 2-year-old boy was brought with an abnormally large and patulous urethral opening at the mid-penile region with intact prepuce and chordee. In this case report, we will review the available literature on this rare variant and discuss its management.

Factors affecting crossing structure use by khulan and goitered gazelle in China

Quantifying the utilization of wildlife crossing structures (CSs) requires considering the local population background. This study assessed the effectiveness of 22 CSs based on the abundance of two ungulates (khulan and goitered gazelle) in northwestern China and analyzed variables influencing their usage such as openness, water source, and human activities in drylands. Results showed that there were 7 and 13 CSs with higher performance indices (PRi) for khulan and goitered gazelle, respectively. Khulan favors CSs near water sources and with large openness, while goitered gazelle prefers structures that include ponding and also feature large openness. Factors like distance to the CSs of the railway, predators, and human activities affect the utilization of CSs by goitered gazelle. This study emphasized the importance of designing and managing effective wildlife CSs by focusing on openness and water resources. It is recommended that CSs can be spatially consistent in multiple transportation lines run parallel.

Characterization of Skoliomonas gen. nov., a haloalkaliphilic anaerobe related to barthelonids (Metamonada).

Metamonads are a large and exclusively anaerobic group of protists. Additionally, they are one of the three clades proposed to ancestrally possess an "excavate" cell morphology, with a conspicuous ventral groove accompanied by a posterior flagellum with a vane. Here, we cultivate and characterize four anaerobic bacterivorous flagellates from hypersaline and alkaline soda lake environments, which represent a novel clade. Small subunit ribosomal RNA (SSU rRNA) gene phylogenies support recent phylogenomic analyses in placing them as the sister of barthelonids, a group that is itself sister to or deeply branching within Fornicata (Metamonada). The new isolates have a distinctive morphology: the hunchbacked cell body is traversed by a narrow ventral groove ending in a large opening to a conspicuous recurrent cytopharynx. The right margin of the groove is defined by a thin "lip." The posterior flagellum bears a wide ventral-facing vane. The narrow ventral groove and elongate cytopharynx are shared with barthelonids. We describe one isolate as Skoliomonas litria, gen. et sp. nov. Further investigation of their mitochondrial-related organelles (MROs) and detailed ultrastructural studies would be important to understanding the adaptation to anaerobic conditions in Metamonads-especially fornicates-as well as the evolution of the "excavate" cell architecture.

Large-deformation finite-element modelling of face instability during tunnelling in clayey soils: Incorporating dynamic excavation process

Earth pressure balance (EPB) shield tunnelling plays a crucial role in urban infrastructure development but faces challenges due to potential face instability. Previous studies often overlook the impact of dynamic excavation processes on face stability, particularly in clayey soils. This study proposes a three-dimensional coupled Eulerian-Lagrangian (CEL) large-deformation approach to explore the failure process of tunnel face in clayey soils during both EPB shutdown and excavation conditions by incorporating the influence of dynamic excavation process. The findings reveal that the face stability during dynamic excavation conditions is consistently lower than that during EPB shutdown, indicating that neglecting dynamic excavation effects could overestimate face stability, potentially compromising construction safety. Moreover, when considering the dynamic excavation process, the opening ratio ξ (the ratio between the cross-section area of cutterhead opening to the total area of tunnel face) is a critical factor affecting face stability. As expected, the face is more stable for a small opening ratio (e.g., ξ = 15 %) while face stability is reduced for a large opening ratio (e.g., ξ = 30 % and 50 %). This is because for large opening ratio, the soil disturbance caused by the cutterhead excavation process exceeds the supportive effect that the cutterhead panels can provide to the face. Finally, the obtained numerical results were used to calculate support pressure in a real tunnel project considering the dynamic excavation process, which matches well with the measured data in the project, validating the effectiveness and superiority of the current CEL approach in modelling face instability and estimating face support pressure. This study offers a significant advancement over the traditional methods for the design of support pressure in clayey soils, providing new insight into the dynamic cutterhead-soil interaction and valuable guidance for reducing the risk of face collapse.

Risk factors for delayed bone union in opening wedge high tibial osteotomy.

The purpose of this study was to investigate the relationship between patient demographics and potential intraoperative factors and delayed bone union in opening wedge high tibial osteotomy (OWHTO). A retrospective review of 65 patients (37 females, 28 males; mean age: 60.1±10.1 years; range, 44 to 77 years) who underwent OWHTO using an angle-stable implant with beta-tricalcium phosphate gap filling between September 2016 and October 2019 was conducted. The osteotomy site was divided into five zones from the lateral hinge on anteroposterior radiographs, and we defined the zone in which bone healing was observed. The bone union area was assessed according to this definition at three, six, nine, and 12 months after surgery, and bone union was defined as union at the fourth zone or greater. A generalized estimating equations approach was employed to investigate longitudinal data pertaining to bone union area as a dependent variable. In addition, the association of bone union at six months postoperatively and predictors were evaluated using cross-sectional statistical methods. The categorical predictors included in the models were smoking, diabetes, hinge fracture, and autologous osteophyte grafting. The continuous variables included in the models were age, body mass index, opening gap width, and plate position. Smoking (odds ratio [OR]=0.478, p<0.01), large opening gap width (OR=0.941, p=0.014), and anterior plate placement (OR=0.971, p<0.01) were significantly associated with decreased bone union area. Union rate at six months in smokers was significantly lower compared to nonsmokers (16.6% and 67.8%, respectively; OR=0.10, p=0.023). Area under the curve in the receiver operating characteristic analysis for bone union at six months was 0.60 for gap width and 0.63 for plate placement. Smoking, large opening gap width, and anterior plate placement are risk factors for delayed bone union after OWHTO. Surgeons should avoid anterior placement of the plate and carefully consider other options for smokers and those who require a large correction.

Exploring high-emission driving behaviors of heavy-duty diesel vehicles based on engine principles under different road grade levels

To reveal the outstanding high-emission problems that occur when heavy-duty diesel vehicles (HDDV) pass uphill and downhill, this study proposes a method to depict the nitrogen oxides (NOx) and carbon dioxide (CO2) high-emission driving behaviors caused by slopes from the perspective of engine principles. By calculating emission and grade data of HDDV based on on-board diagnostic (OBD) data and digital elevation model (DEM) data, the 262 short trips including uphill, flat-road and downhill are firstly obtained through the rule-based short trip segmentation method, and the significant correlation between the road grade and emissions of the short trips is verified by Kendall's Tau and K-means clustering. Secondly, by comparing the distribution changes of three speed categories (acceleration state, constant speed state and deceleration state), the differences in HDDV operating states under different grade levels are discussed. Finally, the machine learning models (Random Forest, XGBoost and Elastic Net), are used to develop the NOx and CO2 emission estimation model, identifying high-emission driving behaviors, particularly during uphill driving, which showed the highest proportion of high-emission. Explained by the feature importance and SHapley Additive exPlanations (SHAP) model that large accelerator pedal opening, frequent aggressive acceleration, and high engine load have positive effects both on NOx and CO2 emissions. The difference is in the air-fuel ratio that the engine in the rich or slightly lean burning state will increase CO2 emissions and the lean burning state will increase NOx emissions. In addition, due to the uncertainty of the actual uphill, drivers often undergo a rapid “deceleration-uniform-acceleration” process, which significantly contributes to high NOx and CO2 emissions from the engine perspective. The findings provide insights for designing driving strategies in slope scenarios and offer a novel perspective on depicting driving behaviors.

The effects of brick wall and RC tie variables on the seismic performance of low-rise confined masonry buildings

An extensive parametric investigation is carried out to determine the effects of different RC tie system and brick wall variables on the performance of confined masonry walls and buildings. The variables considered include: the number of storeys and adjacent walls, the walls aspect ratio, thickness and compressive strength of masonry walls, presence of openings, the RC tie system dimensions, compressive strength and detailing of the longitudinal and transverse reinforcements. The main aim of the investigation is to verify the efficiency of some of the prescriptive code recommendations and to provide a basis for further descriptive guidelines for low-rise confined masonry buildings. Among the major conclusions, it is found that the main affecting parameters are those of the masonry walls themselves. When the walls have sufficient shear capacities, due to lower aspect ratio, higher compressive strength and wall thickness and lack of, or small openings, the flexural demand on the tie system is small and its elements act mainly as axially-loaded tie elements. Therefore, the least affecting parameters are those of the tie system's reinforcement detailing. However, when the masonry walls are weak in shear (low masonry strength and large openings), the demand on the tie system increases, to the point that instead of acting as an integral part of the wall, it acts similar to a weak, moment-resisting frame having infill masonry walls, for which it has not been designed. The scenarios that this will happen include: the wall aspect ratios AR > 2, the masonry compressive strength, f′m < 5.0 MPa and the ratio of length of opening to the length of the wall, Ol/Wl > 0.5. To avoid such behaviour, it is also suggested that the tensile stresses in the longitudinal bars of the RC tie elements be limited to 0.6fy.

Pore-Specific Anisotropic Etching of Zeolitic Imidazolate Frameworks by Carboxylic Acid Vapors.

Anisotropic etching is a powerful way to customize metal-organic frameworks with advanced nanostructures, but it is still in its infancy. Herein, we proposed an unprecedented etching strategy that created anisotropic hollow structures in various zeolitic imidazolate framework (ZIF) nano/single crystals via pore-specific carving. The etching occurred through a newly discovered gas-solid reaction where carboxylic acid vapors bind with ligands in ZIFs at room temperature to form ionic liquid (IL). A series of experiments were conducted to decode the origin of anisotropy and the "hollowing out" effect. We found that large pore openings on {111} facets provide access for the entry of carboxylic acid vapors and the outflow of the IL, resulting in pore-dependent anisotropy features. The unique "etching after adsorption" mechanism and the adsorption capacity of the IL enable acid vapors to hollow out nanocrystals and even single crystals. By altering carboxylic acids and ligands in ZIFs, the etching process can be precisely tuned from the inside out or the outside in. This new method demonstrates broad universality and brings unprecedented morphologies and complexities. It may offer great opportunities for achieving purposeful modification of ZIFs and the rational construction of intricate architectures.

Fine Particulate Matter Components and Risk of Rheumatoid Arthritis: A Large General Canadian Open Cohort Study.

Exposure to fine particulate matter (PM2.5) has been linked to many diseases. However, it remains unclear which PM2.5 chemical components for these diseases, including rheumatoid arthritis (RA), are more harmful. This study aimed to assess potential associations between PM2.5 components and RA and quantify the individual effects of each chemical component on RA risk. An open cohort of 11,696,930 Canadian adults was assembled using Ontario administrative health data from January 2007 onward. Individuals were followed until RA onset, death, emigration from Ontario, or the end of the study (December 2019). Incident RA cases were defined by physician billing and hospitalization discharge diagnostic codes. The average levels of PM2.5 components (ammonium, black carbon, mineral dust, nitrate, organic matter, sea salt, and sulfate) for 5 years before cohort entry were assigned to participants based on residential postal codes. A quantile g-computation and Cox proportional hazard models for time to RA onset were developed for the mixture of PM2.5 components and environmental overall PM2.5, respectively. We identified 67,676 new RA cases across 130,934,256 person-years. The adjusted hazard ratios for the time to RA onset were 1.027 and 1.023 (95% confidence intervals 1.021-1.033 and 1.017-1.029) per every decile increase in exposures to all seven components and per 1 μg/m3 increase in the overall PM2.5, respectively. Ammonium contributed the most to RA onset in the seven components. Exposure to PM2.5 components was modestly associated with RA risk. Public health efforts focusing on specific components (eg, ammonium) may be a more efficient way to reduce RA burden.