Retention Of Structures Research Articles

Beneficial role of short-term aging on creep performance of cold-worked Ti-added 14Cr–15Ni stainless steel

AbstractThe initial microstructure of cold-worked Ti-added 14Cr–15Ni stainless steel was modified through short-term aging and its influence on creep properties has been investigated at a test temperature of 973 K and two stress levels of 150 and 175 MPa. The improvement in rupture life of the condition comprising of post-aging was nominal at 175 MPa, but enhanced more than two times at 150 MPa when compared to the condition which comprised of prior cold work alone. Microstructural examination after creep testing showed that though M23C6 type of precipitates was prominent in both conditions, their size distribution varied with respect to processing condition (viz., one with prior cold work and another comprising of prior cold work followed by aging) as well as applied stress. Retention of cold work-induced dislocation structures aided by secondary TiC precipitates in the aged condition enhanced the rupture life at 150 MPa. Extensive recovery of the dislocation substructure was observed in the unaged condition tested at the same stress level. The size distribution of the dimples observed from the fractographs could be correlated with the extent of creep-induced cavitation. This work describes how the two preprocessing conditions influence the nucleation of M23C6 and secondary TiC precipitates during creep deformation. Graphical Abstract

CryoTRANS: predicting high-resolution maps of rare conformations from self-supervised trajectories in cryo-EM

Cryogenic electron microscopy (cryo-EM) has revolutionized structural biology, enabling efficient determination of structures at near-atomic resolutions. However, a common challenge arises from the severe imbalance among various conformations of vitrified particles, leading to low-resolution reconstructions in rare conformations due to a lack of particle images in these quasi-stable states. We introduce CryoTRANS, a method that predicts high-resolution maps of rare conformations by constructing a self-supervised pseudo-trajectory between density maps of varying resolutions. This trajectory is represented by an ordinary differential equation parameterized by a deep neural network, ensuring retention of detailed structures from high-resolution density maps. By leveraging a single high-resolution density map, CryoTRANS significantly improves the reconstruction of rare conformations and has been validated on four real-world datasets: alpha-2-macroglobulin, actin-binding protein complexes, SARS-CoV-2 spike glycoprotein, and the 70S ribosome. CryoTRANS can also predict high-resolution structures in cryogenic electron tomography maps using a high-resolution cryo-EM map.

Imaging-Based Drug Penetration Profiling in an Excised Sheep Cornea Model.

Formulations designed to address ocular conditions and diseases are predominantly administered topically. While in vitro test systems have been developed to assess corneal permeation under extended contact conditions, methods focusing on determining the penetration depth and kinetics of a substance within the cornea itself rather than through it, are scarce. This study introduces a method for time-dependent penetration depth analysis (10 and 60 min) by means of a semiquantitative imaging method in comparison with a quantitative corneal depth-cut technique, employing fluorescein sodium at concentrations of 0.2 and 0.4 mg/mL as a small molecule model substance and sheep cornea as a human surrogate. Excised tissues exhibited sustained viability in modified artificial aqueous humor and maintained thickness (746 ± 43 µm) and integrity (electrical resistance 488 ± 218 Ω∙cm2) under the experimental conditions. Both methods effectively demonstrated the expected concentration- and time-dependent depth of penetration of fluorescein sodium, displaying a significantly strong correlation. The traceability of the kinetic processes was validated with polysorbate 80, which acted as a penetration enhancer. Furthermore, the imaging-based method enabled detecting the retention of larger structures, such as hyaluronic acid and nanoemulsions from the commercial eyedrop formulation NEOVIS® TOTAL multi, inside the lacrimal layer.

Synthesis and characterization of multi-walled carbon nanotube-reinforced Ti–Mg alloy prepared by mechanical alloying and microwave sintering

Titanium-magnesium (Ti–Mg) alloy is a widely accepted bimetallic material suitable for biomedical applications. However, reduced wear and corrosion resistance, low strength and hardness, and stress shielding effect limit their widespread applications. Reinforcing multi-walled carbon nanotubes (MWCNTs) possessing low density, high modulus, and improved mechanical properties overcome the shortcomings of Ti–Mg alloy. In the present work, nanostructured Ti–Mg alloy was synthesized at room temperature and simultaneously reinforced with MWCNTs. The high energetic ball milling process (HEBM) has been successfully utilized to mechanically alloy Ti with Mg at room temperature by decreasing the grain size to the nanoscale and reinforcing the alloy with MWCNTs. The synthesized nanostructured powder size was 25 nm. Characterization results have shown the emergence of new phases like Ti4C4 and Mg2C3 as a result of mechanical alloying (MA). The reinforced alloy powder was consolidated by cold compaction and followed by microwave sintering. The consolidated sample crystallite size attained was 72 nm and then characterized by Nanoindentation, XRD, and SEM. XRD results show intermetallic compounds Mg2C3 and TiC in bulk samples. SADP TEM confirmed the retention of Nano and partial amorphous structures in the consolidated samples. The nanoindentation test revealed the hardness and elastic modulus values 0.93 GPa and 28.12 GPa, respectively, equivalent to CpTi and its associated alloys. The results are prevalent in those alloys used in biomedical applications produced by conventional melting and casting techniques and can be a potential biomaterial.

Phase Transitions Involving Channel Hydrates of a New Pharmaceutical Compound.

Hydrates are often used as pharmaceutical active pharmaceutical ingredients (API), especially when anhydrates may not be feasible likely due to physicochemical properties concerns. Pharmaceutical hydrates, whereas water is present as crystal adduct, are feasible for drug products as they do not pose any safety concern. Hydrates can impart many different advantages; therefore, they are quite common and preferred solid forms for numerous pharmaceutical materials on market. However, hydrates may involve various phase transitions, which may impact the stability and processability of drug substance. Phase transitions, which include temperature-induced dehydration and moisture-facilitated rehydration are investigated by different solid-state analytical techniques such as powder x-ray diffraction, thermogravimetric analysis, differential scanning calorimetry, polarized light microscopy, and single-crystal x-ray diffraction. This research investigation focuses on the different phase transition behaviors of a newly discovered pharmaceutical compound with three channel hydrates, two of which confirmed by single-crystal analysis. The retention or rearrangement of crystal structures over the transitions are studied. Hydrate 3 exhibits a characteristic feature of channel hydrate that involves symmetric lattice relaxation.Unlike hydrate 3, hydrate 2 results in a potentially new unit cell upon dehydration due to asymmetric lattice relaxation, which converted back to Hydrate 2 in presence of water, a very unique behavior for a channel hydrate, rarely observed, which entails novelty of this research work. The relationship among crystal forms of different hydrates of this new compound is thus established. The current investigation is a vital part of drug product risk assessment for hydrates to avoid any challenges during manufacturing operations and/or stability studies. This investigation was successfully applied in the present study and can be expanded to other newly discovered APIs in future.

Volatility and chemical composition of secondary organic aerosol derived from acenaphthylene and acenaphthene under various oxidant conditions

Acenaphthene (ACE) and acenaphthylene (ACY), distinguished by their unique structures, exhibit high reactivity among polycyclic aromatic hydrocarbons (PAHs). Particularly, the rapid ozonolysis of the carbon-carbon double bond in ACY and the swift oxidation of the fused cyclopenta ring in both ACE and ACY by NO3 underscore their distinct atmospheric fate. Through the utilization of a thermo denuder and high-resolution mass spectrometry, the chemical composition and volatility of four types of secondary organic aerosols (SOA) derived from ACE and ACY are investigated. The chemical composition of SOA formed by ACY ozonolysis is characterized by low O: C ratios and high unsaturation, suggesting the retention of aromatic structures. This leads to measured high SOA volatility and is consistent with the low reactivity of O3 with aromatic compounds. In contrast to ozonolysis, the reaction of NO3 with ACY could yield SOA with very low volatility, characterized by abundant dimers and highly oxidized products. Furthermore, the prevalence of compounds with 11 carbon atoms suggests the presence of complex mechanisms in the ACY oxidation process initiated by NO3, where dealkylation reactions and cleavage reactions may be pivotal. The diverse chemical composition and volatility of SOA from ACE and ACY reacting with NO3 radicals highlight the substantial impact of precursor structure on SOA chemical composition, particularly concerning the presence of active carbon-carbon double bonds. The higher O: C ratio of SOA from OH-initiated oxidation of ACE indicates the significant role of OH in the oxidation of PAHs. These findings offer valuable insights into the atmospheric fate of these PAHs, underscoring the necessity for a comprehensive understanding of their degradation processes and the formation of SOA.

Structure of Metal-Organic Frameworks Eco-Modulated by Acid-Base Balance toward Biobased Flame Retardant in Polyurea Composites.

Biobased-functionalized metal-organic frameworks (Bio-FUN-MOFs) stand out from the crowd of candidates in the flame-retardant field due to their multipathway flame-retardant mechanisms and green synthesis processes. However, exploring and designing Bio-FUN-MOFs tend to counteract the problem of compromising the flame-retardant advantages of MOFs themselves, which inevitably results in a waste of resources. Herein, a strategy in which MOFs are ecologically regulated through acid-base balance is presented for controllable preparation of Bio-FUN-MOFs by two birds with one stone, i.e., higher flame-retardant element loading and retention of more MOF structures. Specifically, the buffer layer is created on the periphery of ZIF-67 by weak etching of biobased alkali arginine to resist the excessive etching of ZIF-67 by phytic acid when loading phosphorus source and to preserve the integrity of internal crystals as much as possible. As a proof of concept, ZIF-67 was almost completely etched out by phytic acid in the absence of arginine. The arginine and phytic acid-functionalized ZIF-67 with yolk@shell structure (ZIF@Arg-Co-PA) obtained by this strategy, as a biobased flame retardant, reduces fire hazards for polyurea composites. At only 5 wt % loading, ZIF@Arg-Co-PA imparted polyurea composites with a limiting oxygen index of 23.2%, and the peaks of heat release rate, total heat release, and total smoke production were reduced by 43.8, 32.3, and 34.3%, respectively, compared to neat polyurea. Additionally, the prepared polyurea composites have acceptable mechanical properties. This work will shed light on the advanced structural design of polymer composites with excellent fire safety, especially environmentally friendly and efficient biobased MOF flame retardants.

Handmade Flashcards for Developing English Comprehension of Rural EFL Young Learners

This research investigates the effectiveness of handmade flashcards as a teaching tool to improve English comprehension among rural EFL young learners. It aims at enhancing vocabulary retention and overall language comprehension by providing a hands-on, visually appealing learning experience. The research also addresses the lack of resources and engagement in rural EFL classrooms, bridging the gap through innovative approaches. It has implications for EFL teaching practices in rural settings, highlighting handmade flashcards as practical and accessible resources to address resource limitations. The qualitative method as research design involves data collection, classroom observations, and interviews. The sample comprises rural EFL young learners aged 12-13 from diverse backgrounds, ensuring representation of various factors affecting English comprehension. The research findings show that handmade flashcards had positive impact on the students. They exhibited increasing engagement, vocabulary retention, and better understanding of sentence structures and context. Peer interactions, fostering collaboration, and communication skills are also encouraged. These ideas can facilitate vocabulary acquisition, active learning, and language development among young learners. Further exploration and implementation of such innovative materials to support effective EFL instruction in developing English comprehension of rural areas should be conducted, ultimately for empowering both teachers and Young Learners.

Distribution of osteoprotegerin in unruptured intracranial aneurysms in humans: association with aneurysm wall protective remodeling.

Aneurysm wall inflammation is associated with lesion instability in unruptured intracranial aneurysms (UIAs). However, most UIAs remain unruptured during lifelong follow-ups because of simultaneous protective remodeling against the inflammatory response. The protective effects of osteoprotegerin (OPG) in intracranial and abdominal aortic aneurysms have been suggested using rodent models; however, the role of this protein in UIAs in humans remains unclear. Herein, the authors examined the relationship between OPG expression and aneurysm wall integrity in intraoperatively resected UIAs by using immunohistochemical and immunofluorescence staining. Sixteen UIA wall tissue specimens resected between 2017 and 2022 were analyzed. Aneurysm growth was defined as an enlargement > 1 mm or an obvious morphological change over the course of more than 6 months. Three high-power fields were randomly selected from areas expressing high and low levels of OPG within the same aneurysm. To clarify the role of OPG in the human aneurysm wall, the authors compared averaged values for the following pathological features between the 2 OPG expression groups: aneurysm wall thickness, collagen, macrophages, smooth muscle cells, and transforming growth factor beta 1 (TGF-β1). Immunohistochemical staining within the entire tissue area was also analyzed to determine the relationships between OPG expression and different aneurysm growth patterns. Pathological findings were compared between high and low OPG expression levels using the Wilcoxon signed-rank test. The heterogeneous expression of OPG was detected in the walls of UIAs. Lesions expressing high OPG levels had thicker aneurysm walls (327 vs 180 μm, p = 0.002) and higher expression levels of TGF-β1 (8.5% vs 5.4%, p = 0.002) than those expressing low OPG levels. The expression of TGF-β1 was colocalized with that of OPG mainly in the tunica media. Furthermore, lesions expressing high OPG levels had larger α-SMA+ areas (25% vs 13%, p = 0.002). Aneurysm growth was observed in 6 of 9 UIAs with available data: whole sac expansion in 4 and secondary aneurysm formation in 2. Among the 6 UIAs with aneurysm growth, OPG expression was relatively higher in the UIAs with an internal elastic lamina than in those without (17% vs 6.9%). Aneurysm wall integrity was associated with OPG expression in the aneurysm wall. Collectively, the study results indicated that OPG is associated with protective remodeling, which may contribute to the retention of aneurysm wall structures.

Complete Oriented Deviation Texture Loss Based GAN (CODT_GAN) for MRI Image Denoising

The use of denoising is crucial in MRI applications for diagnosing medical conditions. MRI pictures frequently include undesirednoises that might impair the accuracy of a pathological diagnosis. Deep learning networks have recently been used to generate a large number of models for MRI denoising with excellent results. However, the majority of them are incapable of providing clients with additional perceptual features of the image without information loss. In this paper, a novel structural and texture loss approach named Complete Oriented Deviated Texture Loss (CODTL) based GAN (CODT_GAN) was proposed to complete the image denoising task. Initially, a GAN network was used to produce images to resemble original images as closely as feasible. Then the GAN generated image is fed into the proposed CODTL operator to estimate textural loss. This proposed approach incorporates structural loss and textural loss, which has been used to fill in the gaps left by GAN network denoising of MRI images. The effectiveness of the proposed work is evaluated by BraTS’17 dataset. The results of the experiments show that the suggested approach is more reliable and performs better than the traditional methods in terms of both the degree of denoising and retention of the anatomical structures, textural details, and defined contrast.

Evaluating the appropriateness of γ-graphyne derivatives as electrode materials for supercapacitors

DFT calculations were used to study the quantum capacitance of pure, B/Al/Si/N/P-doped, and defective γ-graphyne. Due to the direct relationship between capacitance and electronic states around the Fermi level, structures' electronic properties were evaluated by DOS plots. The results of integrated specific quantum capacitance in the range of water stability potential show an improvement of capacity in each p and n-type doping. The calculated cohesive energies of doped structures reflect the stability enhancement. Also, the stability/capacitance of single and double vacancies in two distinct positions (sp and sp2) were examined. The results illustrate stability retention and quantum capacitance improvement of these defective structures. Among the doped structures, the maximum quantum capacitance is 2251.10 F/gr belonging to the aluminum doped structure (in the sp position). For the defective structures, the maximum quantum capacitance is 4221.69 F/gr belonging to removing two sp carbon atoms. These quantum capacitances significantly improved compared to the pristine structure (1216.87 F/gr) and many other structures. These stunning results can contribute to the design of appropriate structures as electrode materials for high-efficiency supercapacitors.

Effect of Palm Fiber-Hydrated Lime Composition on the Permeability of Stabilised Sandy Soil

Sandy soil is one of the most conventional construction materials used as backfill materials in the retention of structures in foundations. Thisstudy to investigate the composition of admixture permeability experimental to stabilized sandy soil use the composition percentage (4, 6, & 8% hydrated lime only), sandy soil with 2% hydrated lime (0.5%, 1%, and 1.5% palm fiber) and 6% of hydrated lime (0.5%, 1% and 1.5% of palm fiber) proportionally. The results presented that the mixture of 2% and 6% hydrated lime with 0.5%, 1%, and 1.5% of palm fiber proportionally, decreased the percentage of reduction of permeability from 94.22% at 0 days to 66.67% at 7 days. The mixture of 6% of hydrated lime and 1.5% of palm fiber at 0 dan 7 curing time give a better performance. Thus, this helps in using the constant head method in Geotechnical practices.

Canopy openness as the main driver of aculeate Hymenoptera and saproxylic beetle diversity following natural disturbances and salvage logging

Forests are increasingly affected by natural disturbances like fires, insect outbreaks, and windstorms. Such disturbances are commonly followed by salvage logging. Disturbance and salvage logging affect biodiversity by altering microclimate, habitat structure, and deadwood amount. To mitigate possible negative effects of salvage logging on biodiversity, ecologists often recommend the retention of disturbance-created structures. However, the mechanisms through which retained structures affect biodiversity remain largely unknown. We analysed 9,602 individuals of saproxylic beetles belonging to 268 species and 3,172 individuals of aculeate Hymenoptera belonging to 68 species of cavity-nesters and 126 species of non-cavity-nesters over two years in a wind-disturbed beech forests with various intensity of salvage logging. We quantified the relative importance of canopy openness and deadwood amount. Our final dataset consisted of 268 saproxylic beetle species and 194 species of aculeate Hymenoptera out of which 68 were cavity-nesters and 126 non cavity-nesters. Generalized linear mixed effect models showed the lowest number of Hymenoptera and beetle species in undisturbed forest. Permutational analysis of variance revealed that treatment and canopy openness drive community composition of both taxa. Increased canopy openness was the main factor positively affecting numbers of species of aculeate Hymenoptera and saproxylic beetles in the first two years after the disturbance. Deadwood amount only affected community composition of saproxylic beetles. However, gamma diversity and community composition of saproxylic beetles indicated that disturbed and extensively logged plots resembled disturbed unlogged plots rather than disturbed and intensively logged plots. Our findings suggest that at least some timber might be extracted from disturbed areas, without major losses of biodiversity of saproxylic beetles and aculeate Hymenoptera.

Response of Soybean Yield and Certain Growth Parameters to Simulated Reproductive Structure Removal

Soybeans often encounter several in-season stressors that can alter retention of reproductive structures. To understand soybean response to structural losses through altered growth parameters—and, ultimately, yield—a field trial was established in Bixby, Oklahoma, in 2019 and 2020 and Perkins, Oklahoma, in 2019. Removal of reproductive structures occurred at full flower (R2), the beginning of pod development (R3), and the beginning of seed development (R5) and at three locations on the plant (top third (T), middle third (M), whole (W)). The impact of flower removal on yield at the R2 and R3 stages did not significantly differ from that in non-treated soybean. Pod removal as late as R5 from the upper fruiting positions (T) had a lesser impact on overall yield, with R5:T showing a reduction in seed number of 860 seeds plant−1, whereas R5:M was 1921 seeds plant−1 below the non-treated soybean. The middle portion of the mainstem was the location where the loss demonstrated was paramount at R5, as this region is a large sink and major contributor to yield. Late-season, stress-negating yield recovery, depending on the severity, may indicate that management practices should anticipate physiological limitations for stress, as well as the potential for relative yield recovery and yield improvement.

A Contour Line Group Simplification Method Based on Classified Terrain Features

Contour line group simplification methods can effectively preserve terrain features during map making and producing. This process involves two main steps, namely terrain feature line extraction and contour bend selection. The terrain feature line extraction includes two steps, that is, terrain feature point extraction and classification, and terrain feature line connection. However, to date, many similar studies have not considered the hierarchy of terrain features. Therefore, we proposed a group simplification method for contour lines based on classified terrain features and tested it on a study area with mainly positive landforms. In accordance with geomorphological theory, we divided valleys into either gradually descending or ordinary. Valley points were extracted based on the constrained Delaunay triangulation method and then classified into the two categories. Gradually descending and ordinary valley lines were then connected. The contour bends were grouped based on the valley lines extracted and then selected according to the geometric indicators of the bend group. The results have demonstrated that the valley lines extracted closely matched human perception in integrity and structure. Contour lines simplified by our method achieved effective reduction of map information and adequate retention of the main terrain structures, which are similar to those from manual simplification.

Synthesis of AgI and AuI Complexes from Tetra(thiophene‐NHC)‐Substituted Ethylene and Their Tunable Fluorescence Properties

AbstractDinuclear silver(I) and gold(I) complexes have been prepared from (NHC‐thiophene)‐substituted ethylene (NHC = N‐heterocyclic carbene). Both the 1,2,3,4‐tetrathienylethene (TTE)‐bridged tetrakisazolium salts (H4‐L1(PF6)4 and H4‐L2(PF6)4) and the 2,2′‐(diphenylethene‐1,1‐diyl)dithiophene (DPDT)‐bridged bisimidazolium ligand precursors H4‐L3(PF6)2 have been prepared and are treated with Ag2O to give dinuclear tetracarbene complexes [Ag2L](PF6)2 (L = L1, L2) and [Ag2(L3)2](PF6)2, respectively. The silver(I) complexes undergo a transmetalation reaction with [AuCl(THT)] (THT = tetrahydrothiophene) to furnish gold(I) NHC complexes with retention of the original structures. All complexes have been characterized by multi‐nuclear magnetic resonance (NMR) and high‐resolution electrospray ionization (HR‐ESI) mass spectrometry, and single‐crystal X‐ray diffraction analysis. The thiophene‐containing NHC complexes exhibit aggregation‐induced emission behavior in acetonitrile/water solutions and temperature‐dependent fluorescence properties.

Habitat Use for Two Heliothermic Lizards in Longleaf Pine Savannas

Heliothermic lizards, like Aspidoscelis sexlineata (Six-lined Racerunner) and Sceloporus undulatus (Eastern Fence Lizard), use direct solar radiation to maintain high body temperatures needed to fulfill their basic life functions. These lizards are often found in frequently burned Pinus palustris (Longleaf Pine) savannas that provide open, high-quality thermal habitat and foraging opportunities. We examined microhabitat features surrounding 42 locations where we captured lizards using drift-fences within Longleaf Pine savannas from March to May 2017 to better understand the fine-scale habitat components important for these 2 species. We used negative binomial regression, model selection (AICc), and model averaging to identify important variables associated with lizard habitat use. We found both Six-lined Racerunners (n = 52) and Eastern Fence Lizards (n = 38) used microhabitats that were characteristic of open-canopied sites (i.e., more bare ground and grass, and less litter, midstory, and canopy cover). However, their use of sites differed in the forest structure selected. The surface-dwelling Six-lined Racerunner selected sites with more stumps and the arboreal Eastern Fence Lizard selected sites with greater Quercus (oak) basal area. Management for these lizards should include activities that promote their habitat, foraging, and thermoregulatory requirements, such as frequent prescribed fire to maintain savanna-like conditions and the retention of forest structures for basking and refuge.

Quantitative Characterisation of Low Abundant Yeast Mitochondrial Proteins Reveals Compensation for Haplo-Insufficiency in Different Environments.

The quantification of low abundant membrane-binding proteins such as transcriptional factors and chaperones has proven difficult, even with the most sophisticated analytical technologies. Here, we exploit and optimise the non-invasive Fluorescence Correlation Spectroscopy (FCS) for the quantitation of low abundance proteins, and as proof of principle, we choose two interacting proteins involved in the fission of mitochondria in yeast, Fis1p and Mdv1p. In Saccharomyces cerevisiae, the recruitment of Fis1p and Mdv1p to mitochondria is essential for the scission of the organelles and the retention of functional mitochondrial structures in the cell. We use FCS in single GFP-labelled live yeast cells to quantify the protein abundance in homozygote and heterozygote cells and to investigate the impact of the environments on protein copy number, bound/unbound protein state and mobility kinetics. Both proteins were observed to localise predominantly at mitochondrial structures, with the Mdv1p bound state increasing significantly in a strictly respiratory environment. Moreover, a compensatory mechanism that controls Fis1p abundance upon deletion of one allele was observed in Fis1p but not in Mdv1p, suggesting differential regulation of Fis1p and Mdv1p protein expression.

Synthesis and Characterization of Solvated Lanthanide Tris(trimethylsilyl)siloxides.

In an effort to develop precursors for the production of lanthanide silicate (LnSiOx) materials, the reactions of [Ln(NR2)3] (R = SiMe3) with three equivalents of tris(trimethylsilyl)silanol (H-OSi(SiMe3)3) or H-SST) in tetrahydrofuran (THF) were undertaken. The products were crystallographically characterized as [Ln(SST)3(THF)2] (where Ln = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu). In general, these compounds are similar to the previously reported [Gd(SST)3(THF)2] complex, where each metal center of the monomeric species is found to adopt a trigonal bipyramidal (TBP; τ = av 0.95) geometry; however, the crystallographic structure solutions for these crystals invoke a much larger unit cell that reveals the complex disorder of the axial THF ligands. Using incompletely washed H-SST, the tetrahedrally (T-4) bound [Ln(SST)3(NEt3)] (Ln-NEt3 = Pr-NEt3, Ho-NEt3; NEt3 = triethylamine) compounds were isolated from the same reaction run in toluene. Rational syntheses of amine derivatives were realized by performing the same reaction with pure H-SST in toluene containing the appropriate amine and [Ln(NR2)3] with the final products identified as [Tm(SST)3(NEt3)] (Tm-NEt3) or [Tm(SST)3(NHPr2i)] (NHPr2i = di-iso-propylamine; Tm-NHPr2i). The products isolated from reactions undertaken in pyridine (py) were identified as [Ln(SST)3(py)2] (Ln-py = Ce-py, Eu-py, and Tm-py). The Ln-py structures exhibit the larger unit cell noted for the THF derivatives with each Ln adopting a TBP (τ = av 0.98) metal center possessing equatorial SST and axial py ligands. The same reaction run in toluene led to the isolation of [(η6-tol)Tm(SST)3] (Tm-tol). Multinuclear NMR (1H and 29Si) data support the retention of the solid-state structures of all of these compounds in solution. Photoluminescent measurements of Tb, Sm, Dy, and Eu were found to display emission and lifetime profiles in the visible range due to f-f transitions, consistent with trivalent lanthanide metal centers.

AEducaAR, Anatomical Education in Augmented Reality: A Pilot Experience of an Innovative Educational Tool Combining AR Technology and 3D Printing.

Gross anatomy knowledge is an essential element for medical students in their education, and nowadays, cadaver-based instruction represents the main instructional tool able to provide three-dimensional (3D) and topographical comprehensions. The aim of the study was to develop and test a prototype of an innovative tool for medical education in human anatomy based on the combination of augmented reality (AR) technology and a tangible 3D printed model that can be explored and manipulated by trainees, thus favoring a three-dimensional and topographical learning approach. After development of the tool, called AEducaAR (Anatomical Education with Augmented Reality), it was tested and evaluated by 62 second-year degree medical students attending the human anatomy course at the International School of Medicine and Surgery of the University of Bologna. Students were divided into two groups: AEducaAR-based learning (“AEducaAR group”) was compared to standard learning using human anatomy atlas (“Control group”). Both groups performed an objective test and an anonymous questionnaire. In the objective test, the results showed no significant difference between the two learning methods; instead, in the questionnaire, students showed enthusiasm and interest for the new tool and highlighted its training potentiality in open-ended comments. Therefore, the presented AEducaAR tool, once implemented, may contribute to enhancing students’ motivation for learning, increasing long-term memory retention and 3D comprehension of anatomical structures. Moreover, this new tool might help medical students to approach to innovative medical devices and technologies useful in their future careers.