Single-Step Control of Liquid-Liquid Crystalline Phase Separation by Depletion Gradients

Fine-tuning nucleation and growth of colloidal liquid crystalline (LC) droplets, also known as tactoids, is highly desirable in both fundamental science and technological applications. However, the tactoid structure results from the trade-off between thermodynamics and nonequilibrium kinetics effects, and controlling liquid-liquid crystalline phase separation (LLCPS) in these systems is still a work in progress. Here, a single-step strategy is introduced to obtain a rich palette of morphologies for tactoids formed via nucleation and growth within an initially isotropic phase exposed to a gradient of depletants. The simultaneous appearance is shown of rich LC structures along the depleting potential gradient, where the position of each LC structure is correlated with the magnitude of the depleting potential. Changing the size (nanoparticles) or the nature (polymers) of the depleting agent provides additional, precise control over the resulting LC structures through a size-selective mechanism, where the depletant may be found both within and outside the LC droplets. The use of depletion gradients from depletants of varying sizes and nature offers a powerful toolbox for manipulation, templating, imaging, and understanding heterogeneous colloidal LC structures.

Digital Templating of Hip Arthroplasty Using Microsoft PowerPoint: A Pilot Study with Technical Details

Templating is essential in hip arthroplasty preparation, facilitating implant size prediction and surgical rehearsal. It ensures the selection of suitable implants according to patient anatomy and disease, aiming to minimize post-operative complications. Various templating methods exist, including traditional acetate templating on both analog and digital images, alongside digital templating on digital images, which is categorized into 2D and 3D approaches. Despite the popularity of acetate templating on digital images, challenges such as the requirement for physical templates and result preservation persist. To address these limitations, digital templating with software like OrthoSize and Orthoview has been suggested, although not universally accessible. This technical note advocates for Microsoft PowerPoint as an effective alternative for 2D digital templating, highlighting its user-friendly features for image manipulation without needing specialized software. The described method involves scanning acetate templates, adjusting the images in PowerPoint 365 for size, position, and calibration on patient radiographs, and demonstrating reliability through preliminary assessments, with intraclass correlation coefficient (ICC) values indicating a high level of agreement for cup and stem size (ICC = 0.860, 0.841, respectively) but moderate for neck length (ICC = 0.592). We have introduced a method for performing 2D digital templating in the clinical field without the need for specialized software dedicated to digital templating. We believe this method significantly improves the accessibility to 2D digital templating, which was previously limited by the need for digital templating software. Additionally, it enables surgeons to easily establish arthroplasty plans and share them, overcoming the limitations of acetate templates.

THA-Net: A Deep Learning Solution for Next-Generation Templating and Patient-specific Surgical Execution

BACKGROUND

This study introduces THA-Net, a deep learning inpainting algorithm for simulating postoperative total hip arthroplasty (THA) radiographs from a single preoperative pelvis radiograph input, while being able to generate predictions either unconditionally (algorithm chooses implants) or conditionally (surgeon chooses implants).

METHODS

The THA-Net is a deep learning algorithm which receives an input preoperative radiograph and subsequently replaces the target hip joint with THA implants to generate a synthetic yet realistic postoperative radiograph. We trained THA-Net on 356,305 pairs of radiographs from 14,357 patients from a single institution's total joint registry and evaluated the validity (quality of surgical execution) and realism (ability to differentiate real and synthetic radiographs) of its outputs against both human-based and software-based criteria.

RESULTS

The surgical validity of synthetic postoperative radiographs was significantly higher than their real counterparts (mean difference: 0.8 to 1.1 points on 10-point Likert scale, P < .001), but they were not able to be differentiated in terms of realism in blinded expert review. Synthetic images showed excellent validity and realism when analyzed with already validated deep learning models.

CONCLUSION

We developed a THA next-generation templating tool that can generate synthetic radiographs graded higher on ultimate surgical execution than real radiographs from training data. Further refinement of this tool may potentiate patient-specific surgical planning and enable technologies such as robotics, navigation, and augmented reality (an online demo of THA-Net is available at: https://demo.osail.ai/tha_net).

Fabrication of Zigzag Parylene Nanofibers in Liquid Crystals with Electric Field-Induced Defect Structures

Liquid crystals (LCs) have been adopted to induce tunable physical properties that dynamically originated from their unique intrinsic properties responding to external stimuli, such as surface anchoring condition and applied electric field, which enables them to be the template for aligning functional guest materials. We fabricate the fiber array from the electrically modulated (in-plain) nematic LC template using the chemical vapor polymerization (CVP) method. Under an electric field, an induced defect structure with a winding number of -1/2 contains a periodic zigzag disclination line. It is known that LC defect structures can trap the guest materials, such as particles and chemicals. However, the resulting fibers grow along the LC directors, not trapped in the defects. To show the versatility of our platform, nanofibers are fabricated on patterned electrodes representing the alphabets 'CVP.' In addition, the semifluorinated moieties are added to fibers to provide a hydrophobic surface. The resultant orientation-controlled fibers will be used in controllable smart surfaces that can be used in sensors, electronics, photonics, and biomimetic surfaces.

Interfacing Coacervates with Membranes: From Artificial Organelles and Hybrid Protocells to Intracellular Delivery

Compartmentalization is crucial for the functioning of cells. Membranes enclose and protect the cell, regulate the transport of molecules entering and exiting the cell, and organize cellular machinery in subcompartments. In addition, membraneless condensates, or coacervates, offer dynamic compartments that act as biomolecular storage centers, organizational hubs, or reaction crucibles. Emerging evidence shows that phase-separated membraneless bodies in the cell are involved in a wide range of functional interactions with cellular membranes, leading to transmembrane signaling, membrane remodeling, intracellular transport, and vesicle formation. Such functional and dynamic interplay between phase-separated droplets and membranes also offers many potential benefits to artificial cells, as shown by recent studies involving coacervates and liposomes. Depending on the relative sizes and interaction strength between coacervates and membranes, coacervates can serve as artificial membraneless organelles inside liposomes, as templates for membrane assembly and hybrid artificial cell formation, as membrane remodelers for tubulation and possibly division, and finally, as cargo containers for transport and delivery of biomolecules across membranes by endocytosis or direct membrane crossing. Here, recent experimental examples of each of these functions are reviewed and the underlying physicochemical principles and possible future applications are discussed.

Computed Tomography-Based Humeral Templating for Uncemented Elbow Arthroplasty

BACKGROUND

Intramedullary (IM) screw insertion into the distal humerus provides fixation for a novel, uncemented elbow arthroplasty. A multitude of screw sizes is required to accommodate variable humeral morphology. The goal of this study was to use computed tomography (CT) for IM screw sizing and to validate this templating by inserting screws into three-dimensionally (3D) printed models.

METHODS

Computed tomography humerus scans for 30 patients were reformatted in the plane of the distal IM canal. Screw size was templated by measuring the canal diameter at 3 locations corresponding to the lengths of the screws being tested. Interrater and intrarater reliabilities of the measurements were assessed. Three-dimensional models of 5 humeri were printed, and IM screws were placed to achieve a secure endosteal fit.

RESULTS

We identified combinations of body components and IM screw length and diameter for all patients to seat this uncemented elbow arthroplasty. The measurements and screw width determinations were reliable. Canal diameter correlated with age but was unrelated to sex. Screws were inserted into five 3D-printed models which matched the templates and demonstrated mechanical and radiographic evidence of secure fit.

CONCLUSIONS

This study characterizes distal humerus anatomy in the context of IM screw fixation. Humerus CT scans of 30 patients were able to be templated, and validation via implantation of IM screws into 3D models was successful. Computed tomography templating will allow surgeons to predict the optimal screw size prior to implantation. A broad range of screw lengths and diameters is critical for implantation of this novel elbow arthroplasty.

Tuning the Porosity of Dextran Microgels with Supramacromolecular Nanogels as Soft Sacrificial Templates

Hydrogels, as well as colloidal hydrogels (microgels), are important materials for a large variety of applications in the biomedical field. Microgels with a controlled pore size (meso- and macropores) are required for efficient nutrient support, modulation of cell adhesion, removal of metabolic products in cell cultures, and probiotic loading. Common microgel fabrication techniques do not provide sufficient control over pore sizes and geometry. In this work, the natural polysaccharide dextran modified with methacrylate groups is used to synthesize highly monodisperse meso- and macroporous microgels in a size range of 100-150 µm via photo cross-linking in microfluidic droplets. The size of mesopores is varied by the concentration of dextran methacrylate chains in the droplets (50-200 g L-1 ) and the size of macropores is regulated by the integration of pH-degradable supramacromolecular nanogels with diameters of 300 and 700 nm as sacrificial templates. Using permeability assays combined with confocal laser scanning microscopy, it is demonstrated that functional dextran-based microgels with uniform and defined pores could be obtained.

Peptide Macrocyclization Guided by Reversible Covalent Templating

The creation of complementary products via templating is a hallmark feature of nucleic acid replication. Outside of nucleic acid-like molecules, the templated synthesis of a hetero-complementary copy is still rare. Herein we describe one cycle of templated synthesis that creates homomeric macrocyclic peptides guided by linear instructing strands. This strategy utilizes hydrazone formation to pre-organize peptide oligomeric monomers along the template on a solid support resin, and microwave-assisted peptide synthesis to couple monomers and cyclize the strands. With a flexible templating strand, we can alter the size of the complementary macrocycle products by increasing the length and number of the binding peptide oligomers, showing the potential to precisely tune the size of macrocyclic products. For the smaller macrocyclic peptides, the products can be released via hydrolysis and characterized by ESI-MS.

Short term Functional Outcomes of Reverse Shoulder Arthroplasty Following Three-Dimensional Planning is Similar Whether Placed with a Standard Guide or Patient Specific Instrumentation (PSI)

BACKGROUND

Preoperative assessment of the glenoid and surgical placement of the initial guide wire are important in implant positioning during reverse total shoulder arthroplasty (rTSA). Three-dimensional (3D) computed tomography (CT) and patient specific instrumentation (PSI) have improved the placement of the glenoid component, but the impact on clinical outcomes remains unclear. The purpose of this study was to compare short term clinical outcomes after rTSA based on intraoperative technique for central guidewire placement in a cohort of patients that had preoperative 3D planning.

METHODS

A retrospective matched analysis was performed from a multicenter prospective cohort of patients who underwent rTSA with preoperative 3D planning and a minimum of 2-year clinical follow-up. Patients were divided into 2 cohorts based on the technique utilized for glenoid guide pin placement: 1) Standard manufacture guide (SG) that was not customized or 2) PSI. Patient reported outcomes (PROs), active range of motion (ROM), and strength measures were compared between the groups. The ASES score was used to assess the minimum clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptomatic state (PASS).

RESULTS

One hundred seventy patients met the study criteria, including 56 performed with SGs and 122 with PSI. There was no difference in PROs between cohorts. There were no significant differences in the percentage of patients that achieved an ASES MCID, SCB, or PASS. Improvement in internal rotation to the nearest spinal level (p < .001) and at 90° (p = .002) were higher in the SG group and, but likely explained by differences in glenoid lateralization utilized. Improvement in abduction strength (p < .001) and external rotation strength (p = .010) were higher in the PSI group.

CONCLUSION

rTSA performed following preoperative 3D planning leads to similar improvement in PROs regardless of whether a SG or PSI are utilized intraoperatively for central glenoid wire placement. Greater improvement in postoperative strength was observed with the use of PSI, but the clinical significance of this finding is unclear.

All-Solid-State Interdigitated Micro-Supercapacitors Based on Porous Gold Electrodes

Recent developments in embedded electronics require the development of micro sources of energy. In this paper, the fabrication of an on-chip interdigitated all-solid-state supercapacitor, using porous gold electrodes and a PVA/KOH quasisolid electrolyte, is demonstrated. The fabrication of the interdigitated porous gold electrode is performed using an original bottom-up approach. A templating method is used for porosity, using a wet chemistry process followed by microfabrication techniques. This paper reports the first example of an all-gold electrode micro-supercapacitor. The supercapacitor exhibits a specific capacitance equal to 0.28 mF·cm^-2 and a specific energy of 0.14 mJ·cm^-2. The capacitance value remains stable up to more than 8000 cycles.

Macroporous Mannitol Granules Produced by Spray Drying and Sacrificial Templating

In pharmaceutical applications, the porous particles of organic compounds can improve the efficiency of drug delivery, for example into the pulmonary system. We report on the successful preparation of macroporous spherical granules of mannitol using a spray-drying process using polystyrene (PS) beads of ~340 nm diameter as a sacrificial templating agent. An FDA-approved solvent (ethyl acetate) was used to dissolve the PS beads. A combination of infrared spectroscopy and thermogravimetry analysis proved the efficiency of the etching process, provided that enough PS beads were exposed at the granule surface and formed an interconnected network. Using a lab-scale spray dryer and a constant concentration of PS beads, we observed similar granule sizes (~1-3 microns) and different porosity distributions for the mannitol/PS mass ratio ranging from 10:1 to 1:2. When transferred to a pilot-scale spray dryer, the 1:1 mannitol/PS composition resulted in different distributions of granule size and porosity depending on the atomization configuration (two-fluid or rotary nozzle). In all cases, the presence of PS beads in the spray-drying feedstock was found to favor the formation of the α mannitol polymorph and to lead to a small decrease in the mannitol decomposition temperature when heating in an inert atmosphere.

Magnification assessment of radiographs for knee replacement (MARKeR) - A pilot study in a low-resource setting

Background

Selecting the correct size of implants to be used in total knee arthroplasty is critical for a successful outcome. Marker-less templating systems use an institutionally derived magnification factor for all radiographs.

Purpose

To determine the institutional magnification of knee radiographs for patients awaiting total knee arthroplasty.

Material and Methods

Eighty patients awaiting total knee arthroplasty underwent preoperative knee radiographs using a standardized protocol. A marker attached to the patients’ knees at the level of the knee joint was used to calculate the magnification factor on both anteroposterior (AP) and lateral (LAT) views. Two independent observers estimated the magnification to determine the intra and inter-observer reliability.

Results

The mean magnification of the AP (15.3%) radiograph was significantly greater than the LAT (12.1%) radiograph (p< 0.0001). Patients with absent markers on their radiographs were heavier than patients in whom the marker was visible (84.7 kgs vs. 76.6 kgs, p=0.01). No marker was visible on the radiographs in 56.3% (45/80) of patients. There was excellent inter and intra-observer reliability of both the AP and LAT measurements.

Conclusion

After standardizing the protocol for preoperative knee radiographs, our results show significantly greater institutional magnification of the anteroposterior compared with the lateral images. Accurate templating in knee arthroplasty requires both radiographic images. To reduce errors in implant sizing, we recommend surgeons use different institutional magnification factors for the anteroposterior and lateral radiographs.

Microstructure and ionic conductivity investigation of samarium doped ceria (Sm0.2Ce0.8O1.9) electrolytes prepared by the templating methods

Sm0.2Ce0.8O1.9 (SDC20) electrolytes were synthesized with cellulose templating (CT) and PVA templating (PVAT) methods. Powder characteristics were examined using TG/DTA, XRD, and SEM. Pellets are sintered at various temperatures for different durations. Mean grain sizes were calculated from SEM micrographs using the linear intercept method. Grain growth behavior of the electrolytes was investigated and the dominant diffusion mechanism was examined. The grain growth activation energies were obtained for the first time for the mentioned electrolytes prepared by the mentioned methods. The ionic conductivities were calculated by electrochemical impedance spectroscopy. The highest ionic conductivity value was found to be 0.050 S cm-1 for the cellulose templating method.

Macroscopic rods from assembled colloidal particles of hydrothermally carbonized glucose and their use as templates for silicon carbide and tricopper silicide

Self-aggregated colloids can be used for the preparation of materials, and we studied long rod-like aggregates formed on the evaporation of water from dispersed particles of colloidal hydrochar. The monodispersed hydrochar particles (100-200 nm) were synthesized by the hydrothermal carbonization of glucose and purified through dialysis. During the synthesis they formed colloidal dispersions which were electrostatically stable at intermediate to high pH and at low ion strengths. On the evaporation of water, macroscopically large rods formed from the dispersions at intermediate pH conditions. The rods formed at the solid-water interface orthogonally oriented with respect to the drying direction. Pyrolysis rendered the rods highly porous without qualitatively affecting their shape. A Cu-Si alloy was reactively infiltrated into the in-situ pyrolyzed hydrochars and composites of tricopper silicide (Cu₃Si)-silicon carbide (SiC)/carbon formed. During this process, the Si atoms reacted with the C atoms, which in turned caused the alloy to wet and further react with the carbon. The shape of the underlying carbon template was maintained during the reactions, and the formed composite preparation was subsequently calcined into a Cu₃Si-SiC-based replica of the rod-like assemblies of carbon-based colloidal particles. Transmission and scanning electron microscopy, and X-ray diffraction were used to study the shape, composition, and structure of the formed solids. Further studies of materials prepared with reactive infiltration of alloys into self-aggregated and carbon-based solids can be justified from a perspective of colloidal science, as well as the explorative use of hydrochar prepared from real biomass, exploration of the compositional space in relation to the reactive infiltration, and applications of the materials in catalysis.

Development and assessment of 3-dimensional computed tomography measures of proximal humeral bone density: a comparison to established 2-dimensional measures and intraoperative findings in patients undergoing shoulder arthroplasty

Background

The purpose of this study was to develop novel three-dimensional (3D) measures of bone density from computed tomography (CT) scans and to compare them with validated two-dimensional (2D) radiographic assessments of bone density. Patient demographic data were also analyzed to see if there were any predictors of bone density (age, sex, etiology).

Methods

The study group consisted of 290 consecutive patients undergoing primary shoulder arthroplasty surgery (total anatomic, reverse, and hemiarthroplasty). All underwent preoperative CT imaging. Three 3D CT measurements (metaphysis cancellous, metaphysis cortical, and proximal diaphysis) were developed and automated into software. The developed 3D measurements were compared with validated 2D measures (Tingart and Gianotti Index). Patient demographic data were correlated with these measurements. The difference between the size of the final sounder and of the final stem was calculated as Delta.

Results

There was moderately strong correlation between Tingart and Gianotti measures (0.674, P < .001), as well as between 3D metaphysis cancellous measurements and Tingart (0.645, P < .001). Decreased bone density was highly correlated with female sex. Tingart (area under the curve [AUC]: 0.87, 95% confidence interval [CI]: 0.82-0.91) and 3D metaphysis cancellous (AUC: 0.78, 95% CI: 0.72-0.84) had the highest correlation. These were significantly more than other measures of bone density (P < .01). Decreased bone density measured with Tingart also had moderate correlation with advanced age (AUC: 0.67, 95% CI: 0.6-0.73), but less so for etiology (AUC: 0.62, 95% CI: 0.55-0.69). The 3D metaphysis cancellous measure had lower correlation with age (AUC: 0.59, 95% CI: 0.52-0.66) and etiology (AUC: 0.59, 95% CI: 0.52-0.65). The highest correlation with Delta (the difference between the final sounder and the stem size) was with the 3D metaphysis cancellous measure (AUC: 0.67, 95% CI: 0.59-0.73), followed by Tingart (AUC: 0.647, 95% CI: 0.57-0.671). A multiple regression model to predict Delta demonstrated the stronger prediction using 3D metaphysis cancellous (analysis of variance F-ratio of 42.6, P < .001) than Tingart (35.9, P < .001).

Conclusion

This study demonstrates that automated measures of bone density can be obtained from 3D CT scans. Of the three novel 3D measurements of bone density, the humeral metaphysis cancellous measurement was most correlated to the known 2D measures and most correlated to the intraoperative assessment of bone density (delta).

Fabrication of Superconducting Nanowires Using the Template Method

The fabrication and characterization of superconducting nanowires fabricated by the anodic aluminium oxide (AAO) template technique has been reviewed. This templating method was applied to conventional metallic superconductors, as well as to several high-temperature superconductors (HTSc). For filling the templates with superconducting material, several different techniques have been applied in the literature, including electrodeposition, sol-gel techniques, sputtering, and melting. Here, we discuss the various superconducting materials employed and the results obtained. The arising problems in the fabrication process and the difficulties concerning the separation of the nanowires from the templates are pointed out in detail. Furthermore, we compare HTSc nanowires prepared by AAO templating and electrospinning with each other, and give an outlook to further research directions.

Is analog preoperative planning still applicable?-comparison of accuracy of analog and computer preoperative planning methods in total hip arthroplasty

Background

Preoperative planning is an integral part of total hip arthroplasty and has a significant impact on surgical technique and clinical outcome. The variety of types and sizes of endoprosthesis components makes the procedure more demanding and generates a need for accurate preoperative planning. The objective of this study was to analyze an analog method of preoperative planning of primary total hip arthroplasty based on templates overlaying on preoperative radiograms and compare its accuracy for predicting the size, both the stem and cup, with computer planning methods.

Methods

A retrospective cohort study based on 360 X-ray images of hip joints in 348 patients qualified for total hip arthroplasty between 2018 and 2019. The study group consisted of 136 men and 212 women, with an average age of 65 years (56 to 85 years). Material included both cementless and cemented endoprostheses.

Results

In the analyzed material, the accuracy of cup planning using the analog method was 85% (P<0.001) and 77% (P<0.001) in the planning of stem size. However, using the computer method, planning accuracy was 82% (P<0.001) for the cup and 72% (P<0.001) for the stem.

Conclusions

Both methods of preoperative planning remain effective. The analog method of preoperative planning is simple, precise, and repeatable in choosing the type and size of endoprosthesis components with an accuracy of 85% and 77% for the cup and stem respectively. The accuracy of planning depends on the type of endoprosthesis and in the case of the cemented endoprosthesis, it is lower than in cementless.

Molecular Recognition: Perspective and a New Approach

This perspective presents an overview of approaches to the preparation of molecular recognition agents for chemical sensing. These approaches include chemical synthesis, using catalysts from biological systems, partitioning, aptamers, antibodies and molecularly imprinted polymers. The latter three approaches are general in that they can be applied with a large number of analytes, both proteins and smaller molecules like drugs and hormones. Aptamers and antibodies bind analytes rapidly while molecularly imprinted polymers bind much more slowly. Most molecularly imprinted polymers, formed by polymerizing in the presence of a template, contain a high level of covalent crosslinker that causes the polymer to form a separate phase. This results in a material that is rigid with low affinity for analyte and slow binding kinetics. Our approach to templating is to use predominantly or exclusively noncovalent crosslinks. This results in soluble templated polymers that bind analyte rapidly with high affinity. The biggest challenge of this approach is that the chains are tangled when the templated polymer is dissolved in water, blocking access to binding sites.

Prospective Comparison of Available Primary Total Knee Arthroplasty Sizing Equations

BACKGROUND

Several studies have proposed regression equations that can increase the accuracy of predicting femur and tibia component sizes for total knee arthroplasty (TKA). This study compared available regression equations in their ability to prospectively predict component size in a unique patient series.

METHODS

Demographic data and implanted femur and tibia TKA component sizes were collected on a consecutive 382 patients undergoing index TKA. Equations by Bhowmik-Stoker et al, Ren et al, Sershon et al, and Miller et al were identified that used age, race, ethnicity, gender, height, weight, or body mass index. Equation outputs were converted to implant-corrected sizes and compared to the implanted component.

RESULTS

Femur and tibia sizes were accurately predicted within 1 size 88% and 92%, 84% and 86%, and 79% and 92% for Bhowmik-Stoker et al, Sershon et al, and Miller et al, respectively. Ren et al was within 1 tibia size 88% of the time. Adding one more common implant size improved this accuracy by an average of 9.1% and 6.6% for the femur and tibia, respectively. For femur components, Bhowmik-Stoker et al outperformed Sershon et al by 0.14 sizes (P < .001) and Miller et al by 0.21 sizes (P < .001) on average. For tibia components, Bhowmik-Stoker et al outperformed Sershon et al by 0.09 sizes (P = .028) and Ren et al by 0.11 sizes (P = .005) on average.

CONCLUSION

Equations by Bhowmik-Stoker et al more accurately predicted implanted TKA size. In cases of greater uncertainty, the practicing surgeon may err on having more common TKA sizes available.

Accuracy of leg length and femoral offset restoration after total hip arthroplasty with the utilisation of an intraoperative calibration gauge

BACKGROUND

Offset and leg length (LL) restoration are critical for the achievement of a stable, well-functioning hip following total hip arthroplasty (THA). Several techniques are described in the literature, including a hip calibration gauge. We question whether meticulous preoperative planning of a specific surgical technique in combination with the utilisation of a calibration gauge can provide an accurate offset and LL restoration.

METHODS

Retrospective review of 101 unilateral THAs via a posterior approach by a single surgeon. Preoperative radiographic LL and offset were radiographically calculated. Intraoperatively prior to hip dislocation a calibration gauge was used to measure LL and offset with a pin inserted into the iliac crest acting as a static referencing point. All had pelvis x-ray performed 6 weeks postoperatively. A literature review was conducted to establish average postoperative LL/offset values for statistical comparison.

RESULTS

The average absolute postoperative leg-length discrepancy (LLD) was 2.51 mm compared to preoperatively 3.54 mm (p = 0.018). A total of 93.1% and 100% had LLD of ⩽5 mm and ⩽10 mm, respectively. The mean postoperative offset difference was 2.39 mm. The investigated LLD and offset results were comparable with literature data of studies utilising an intraoperative measuring device. LLD was significantly decreased when compared to a free-hand technique (LLD 4.42 mm, p < 0.001).

CONCLUSION

The technique utilising preoperative templating, intraoperative offset verification together with the use of hip calibration gauge yielded accurate LLD and offset restoration as in the literature. Precise offset restoration, which often is a neglected issue, can lead to better abductor vector restoration, hip function and less pain.

Yolk-Shell Nanostructures: Syntheses and Applications for Lithium-Ion Battery Anodes

Yolk-shell nanostructures have attracted tremendous research interest due to their physicochemical properties and unique morphological features stemming from a movable core within a hollow shell. The structural potential for tuning inner space is the focal point of the yolk-shell nanostructures in a way that they can solve the long-lasted problem such as volume expansion and deterioration of lithium-ion battery electrodes. This review gives a comprehensive overview of the design, synthesis, and battery anode applications of yolk-shell nanostructures. The synthetic strategies for yolk-shell nanostructures consist of two categories: templating and self-templating methods. While the templating approach is straightforward in a way that the inner void is formed by removing the sacrificial layer, the self-templating methods cover various different strategies including galvanic replacement, Kirkendall effect, Ostwald ripening, partial removal of core, core injection, core contraction, and surface-protected etching. The battery anode applications of yolk-shell nanostructures are discussed by dividing into alloying and conversion types with details on the synthetic strategies. A successful design of yolk-shell nanostructures battery anodes achieved the improved reversible capacity compared to their bare morphologies (e.g., no capacity retention in 300 cycles for Si@C yolk-shell vs. capacity fading in 10 cycles for Si@C core-shell). This review ends with a summary and concluding remark yolk-shell nanostructures.

Hierarchical Tubular-Structured MoSe2 Nanosheets/N-Doped Carbon Nanocomposite with Enhanced Sodium Storage Properties

Intimately coupled carbon/molybdenum-based hierarchical nanostructures are promising anodes for high-performance sodium-ion batteries owing to the combined effects of the two components and their robust structural stability. Mo-polydopamine (PDA) complexes are appealing precursors for the preparation of various Mo-based nanostructures containing N-doped carbon (NC). A facile method for the fabrication of hierarchical tubular nanocomposites with intimately coupled MoSe₂ and NC nanosheets has been developed, which involves the preparation of Mo-PDA hybrid nanotubes through a chemical route followed by two heat treatments. The strong coupling between Mo anions and the catechol groups in dopamine not only restricts the crystallite size but also inhibits agglomeration during selenization, resulting in few-layered MoSe₂ nanosheets embedded in hierarchical NC substrates. The as-synthesized nanotube composites are constructed by assembling primary MoSe₂ /NC nanosheets. This unique structure not only increases the number of active sites but also shortens the diffusion length of ions and enhances the electronic conductivity of electrode materials. The as-synthesized hierarchical MoSe₂ /NC nanotubes deliver a high capacity of 429 mAh g^-1 at 1 A g^-1 after the 150th cycle when used as anodes in sodium-ion batteries. Furthermore, at a high current density of 10 A g^-1 , a high discharge capacity of 236 mAh g^-1 is achieved.

"Ghost" Silica Nanoparticles of "Host"-Inherited Antibacterial Action

We fabricated surface-rough mesoporous silica nanoparticles ("ghost" SiO₂NPs) by using composite mesoporous copper oxide nanoparticles ("host" CuONPs) as templates, which allowed us to mimic their surface morphology. The "host" CuONPs used here as templates, however, had a very high antibacterial effect, with or without functionalization. To evaluate the surface roughness effect on the "ghost" SiO₂NPs antibacterial action, we functionalized them with (3-glycidyloxypropyl)trimethoxysilane (GLYMO) to permit additional covalent coupling of 4-hydroxyphenylboronic acid (4-HPBA). The diol groups on the bacterial membrane can form reversible covalent bonds with boronic acid (BA) groups on the "ghost" SiO₂NPs surface and bind to the bacteria, resulting in a very strong amplification of their antibacterial activity, which does not depend on electrostatic adhesion. The BA-functionalized "ghost" SiO₂NPs showed a very significant antibacterial effect as compared to smooth SiO₂NPs of the same surface coating and particle size. We attribute this to the "ghost" SiO₂NPs mesoporous surface morphology, which mimics to a certain extent those of the original mesoporous CuONPs used as templates for their preparation. We envisage that the "ghost" SiO₂NPs effectively acquire some of the antibacterial properties from the "host" CuONPs, with the same functionality, despite being completely free of copper. The antibacterial effect of the functionalized "ghost" SiO₂NPs/GLYMO/4-HPBA on Rhodococcus rhodochrous (R. rhodochrous) and Escherichia coli (E. coli) is much higher than that of the nonfunctionalized "ghost" SiO₂NPs or the "ghost" SiO₂NPs/GLYMO. The results indicate that the combination of rough surface morphology and strong adhesion of the particle surface to the bacteria can make even benign material such as silica act as a strong antimicrobial agent. Additionally, our BA-functionalized nanoparticles ("ghost" SiO₂NPs/GLYMO/4-HPBA) showed no detectable cytotoxic impact against human keratinocytes at particle concentrations, which are effective against bacteria.

Nanofibrous, Emulsion-Templated Syndiotactic Polystyrenes with Superhydrophobicity for Oil Spill Cleanup

A series of syndiotactic polystyrene (sPS) monoliths with controllable shapes, nanofibrous structures, hierarchical pores, superhydrophobicity, high specific surface area, and high strength have been fabricated for the first time by solidifying nonaqueous high internal phase emulsions (HIPEs) through crystallization-induced gelation. The nonaqueous HIPEs were formed by dispersing glycerol in 1,2,4-trichlorobenzene stabilized by sulfonated sPS at a high temperature of 120 °C, and with sPS in the continuous phase, these HIPEs were solidified by cooling at room temperature to obtain sPS monoliths. The shapes of the sPS monoliths were controllable, and excitedly, nanofibrous structures were found at void walls, with fiber diameters ranging from 20 to 100 nm. The sPS monoliths exhibited pores in different scales: emulsion-templated voids at nearly 10 μm with pore throats ranging from 1 to 2 μm and macropores and mesopores between nanofibers, enabling the monoliths to exhibit extremely high specific surface area of up to 420 m²·g^-1. The porous sPS monoliths were robust, and they did not fail even at a compressive strain of 70%, with Young's moduli ranging from 157.7 to 2638.0 kPa. The monoliths were superhydrophobic and oleophilic, with water contact angles over 150° and with oils absorbed rapidly. The superhydrophobicity and oleophilicity enabled the porous sPS monoliths to absorb bulk oils on the water surface, underwater oils, and even oils within oil-in-water emulsions. The monoliths absorbed a large amount of organic solvents, edible oils, and fuel oils with equilibrium liquid uptakes up to 81.3, 44.4, and 41.9 g·g^-1 for chloroform, olive oil, and diesel, respectively. The liquid absorption was rapid, and the monoliths exhibited a relatively high reusability. These porous sPS monoliths were demonstrated to be a candidate for the applications of oil/water separation and/or oil spill cleanup.

Nanodot-Directed Formation of Plasmonic-Fluorescent Nanohybrids toward Dual Optical Detection of Glucose and Cholesterol via Hydrogen Peroxide Sensing

Hybrid nanoparticles (NPs) have emerged as an important class of nanomaterials owing to their integrated enhanced properties and functionality. In this study, we have developed an effective nanodot templating strategy for the in situ formation of surfactant-free nanohybrids with unique plasmonic-fluorescent properties. A bright photoluminescent biodot synthesized from serine and histamine biomolecular precursors (Ser-Hist dot) was first engineered to have rich functional groups on the nanosurface capable of anchoring Ag⁺ ions via electrostatic interaction. Upon UV irradiation, free electrons could transfer from the photoexcited Ser-Hist dot to the Ag⁺ ions, facilitating the in situ growth of AgNPs. The resulting nanohybrid system (Bio@AgNPs) exhibits distinct characteristic surface plasmon resonance absorbance and highly quenched PL intensity due to the inner filter effect. Furthermore, the Bio@AgNP nanohybrid retains its redox capability, enabling hydrogen peroxide sensing via AgNP etching, which in turn empowers a dual colorimetric and fluorescent detection of glucose and cholesterol in complex biological samples (i.e., synthetic urine and human plasma) with high selectivity and sensitivity. This finding reveals a new effective and facile method for the preparation of highly functional hybrid nanomaterials for dual-mode detection of hydrogen peroxide-producing species and/or reactions.

Improving the accuracy of digital templating: achieving success through stakeholder management

The use of a marker ball in digital templating for hip arthroplasty is a well-established method of preoperative planning and is used to overcome the inherent magnification in plain film radiographs. Our hospital policy is to place a marker ball in all anteroposterior pelvic films taken in the emergency department (ED) which have been requested for suspected neck of femur fractures. We carried out a baseline measurement followed by three Plan-Do-Study-Act cycles for all pelvic films taken in ED during July 2016, November 2016, February 2017 and November 2017. Interventions between the baseline measurement and cycle 1 were to educate the lead radiographer and publish the results in the radiology newsletter, and between cycles 1 and 2 was to run a teaching session for radiographers, display posters in the X-ray department and place an electronic prompt on the X-ray machine to alert them of the need to place a marker ball in the X-ray field. Cycle 3 looked to see if improvements were sustained. 16/81 (20%) radiographs complied with the policy in our baseline measurement; 25/51 (46%, p=0.002) in cycle 1; 40/54 (74%, p=0.0056) in cycle 2; and 48/63 (76%) in cycle 3. Our quality improvement project led to large improvements in clinical practice through straightforward, small, but appropriately targeted interventions. Stakeholder management is key to successfully implementing change. The next step is to switch from the VoyantMark to the KingMark marker ball, as it has greater accuracy of templating and is also easier to place within the field of an X-ray.

Prospective Validation of a Demographically Based Primary Total Knee Arthroplasty Size Calculator

BACKGROUND

Preoperative planning for total knee arthroplasty (TKA) is essential for streamlining operating room efficiency and reducing costs. Digital templating and patient-specific instrumentation have shown some value in TKA but require additional costs and resources. The purpose of this study was to validate a previously published algorithm that uses only demographic variables to accurately predict TKA tibial and femoral component sizes.

METHODS

Four hundred seventy-four consecutive patients undergoing elective primary TKA were prospectively enrolled. Four surgeons were included, three of which were unaffiliated with the retrospective cohort study. Patient sex, height, and weight were entered into our published Arthroplasty Size Prediction mobile application. Accuracy of the algorithm was compared with the actual sizes of the implanted femoral and tibial components from 5 different implant systems. Multivariate regression analysis was used to identify independent risk factors for inaccurate outliers for our model.

RESULTS

When assessing accuracy to within ±1 size, the accuracies of tibial and femoral components were 87% (412/474) and 76% (360/474). When assessing accuracy to within ±2 sizes of predicted, the tibial accuracy was 97% (461/474), and the femoral accuracy was 95% (450/474). Risk factors for the actual components falling outside of 2 predicted sizes include weight less than 70 kg (odds ratio = 2.47, 95% confidence interval [1.21-5.06], P = .01) and use of an implant system with <2.5 mm incremental changes between femoral sizes (odds ratio = 5.50, 95% confidence interval [3.33-9.11], P < .001).

CONCLUSIONS

This prospective series of patients validates a simple algorithm to predict component sizing for TKA with high accuracy based on demographic variables alone. Surgeons can use this algorithm to simplify the preoperative planning process by reducing unnecessary trays, trials, and implant storage, particularly in the community or outpatient setting where resources are limited. Further assessment of components with less than 2.5-mm differences between femoral sizes is required in the future to make this algorithm more applicable worldwide.

Air Templated Macroporous Epoxy Foams with Silica Particles as Property-Defining Additive

Nonaqueous foams were successfully produced by mechanically beating air into liquid epoxy resin, surfactant, and silica particle mixtures and used as templates to produce macroporous polymers. The air bubbles introduced into the epoxy formulations served as templates for the pores of the cured epoxy foams. The addition of silica particles into the resin mixture resulted in an increased viscosity of the formulation, thus enhancing the stability of the liquid epoxy froths, which could then be thermally cured at 60 °C. Increasing the silica loading in the formulation resulted in an increase of the foam density and decrease of the average pore size of the epoxy foams. The epoxy foams containing silica exhibited a hierarchical pore structure, where large pores were surrounded by smaller pores, and enhanced stiffness as compared to the control epoxy foams with a monomodal pore size distribution.

The external obturator footprint as a landmark in total hip arthroplasty through a direct anterior approach: a CT-based analysis

BACKGROUND:

Anatomical landmarks for templating of total hip arthroplasty (THA) that are visible both during surgery and on radiographs are rare. If surgery is performed through a direct anterior approach the external obturator tendon (EO) is consistently visible. To use this point as a reference the exact position and dimensions of the footprint need to be known.

AIM:

To determine the location and dimension of the EO footprint on pelvic radiographs by correlating the EO anatomy in CT scans with conventional radiographs.

METHODS:

CT scans and radiographs of 200 patients were analysed. The EO tendon was identified on CT scans; the height of its footprint, and its distance to the tip of the greater trochanter and to the anatomical axis of the femur was measured. The accuracy and inter-rater reliability in the identification of the EO footprint was determined.

RESULTS:

The EO tendon was visible on all CT scans and it's footprint was identifiable on all corresponding radiographs. It's cranio-caudal dimension was 6.4 ± 1.4 mm. It's distance to the tip of the greater trochanter was 16.0 ± 3.1 mm. The EO footprint was located 5.2 ± 3.7 mm lateral to the femoral anatomical axis. There was no significant difference regarding the accuracy of EO footprint localisation on radiographs among the 2 readers.

CONCLUSION:

The EO footprint on the greater trochanter is consistently visible on CT scans and radiographs. As the variability of the footprint dimension is small, this structure may serve as a useful landmark in THA, particularly when performed through a direct anterior approach.

Synthesis and Formation Mechanism of All-Organic Block Copolymer-Directed Templating of Laser-Induced Crystalline Silicon Nanostructures

This report describes the generation of three-dimensional (3D) crystalline silicon continuous network nanostructures by coupling all-organic block copolymer self-assembly-directed resin templates with low-temperature silicon chemical vapor deposition and pulsed excimer laser annealing. Organic 3D mesoporous continuous-network resin templates were synthesized from the all-organic self-assembly of an ABC triblock terpolymer and resorcinol-formaldehyde resols. Nanosecond pulsed excimer laser irradiation induced the transient melt transformation of amorphous silicon precursors backfilled in the organic template into complementary 3D mesoporous crystalline silicon nanostructures with high pattern fidelity. Mechanistic studies on laser-induced crystalline silicon nanostructure formation revealed that the resin template was carbonized during transient laser-induced heating on the milli- to nanosecond timescales, thereby imparting enhanced thermal and structural stability to support the silicon melt-crystallization process at temperatures above 1250 °C. Photoablation of the resin material under pulsed excimer laser irradiation was mitigated by depositing an amorphous silicon overlayer on the resin template. This approach represents a potential pathway from organic block copolymer self-assembly to alternative functional hard materials with well-ordered 3D morphologies for potential hybrid photovoltaics, photonic, and energy storage applications.

Multiferroic nanocomposite fabrication via liquid phase using anodic alumina template

We report a novel and inexpensive fabrication process of multiferroic nanocomposite via liquid phase using an anodic alumina template. The sol-gel spin-coating technique was used to coat the template with ferrimagnetic CoFe₂O₄. By dissolving the template with NaOH aqueous solution, a unique nanotube array structure of CoFe₂O₄ was obtained. The CoFe₂O₄ nanotube arrays were filled with, and sandwiched in, ferroelectric BaTiO₃ layers by a sol-gel spin-coating method to obtain the composite. Its multiferroicity was confirmed by measuring the magnetic and dielectric hysteresis loops.

Using Patient Demographics and Statistical Modeling to Predict Knee Tibia Component Sizing in Total Knee Arthroplasty

BACKGROUND

Preoperative planning is important to achieve successful implantation in primary total knee arthroplasty (TKA). However, traditional TKA templating techniques are not accurate enough to predict the component size to a very close range.

METHODS

With the goal of developing a general predictive statistical model using patient demographic information, ordinal logistic regression was applied to build a proportional odds model to predict the tibia component size. The study retrospectively collected the data of 1992 primary Persona Knee System TKA procedures. Of them, 199 procedures were randomly selected as testing data and the rest of the data were randomly partitioned between model training data and model evaluation data with a ratio of 7:3. Different models were trained and evaluated on the training and validation data sets after data exploration.

RESULTS

The final model had patient gender, age, weight, and height as independent variables and predicted the tibia size within 1 size difference 96% of the time on the validation data, 94% of the time on the testing data, and 92% on a prospective cadaver data set.

CONCLUSION

The study results indicated the statistical model built by ordinal logistic regression can increase the accuracy of tibia sizing information for Persona Knee preoperative templating. This research shows statistical modeling may be used with radiographs to dramatically enhance the templating accuracy, efficiency, and quality. In general, this methodology can be applied to other TKA products when the data are applicable.

Tissue-engineered 3D microvessel and capillary network models for the study of vascular phenomena

Advances in tissue engineering, cell biology, microfabrication, and microfluidics have led to the development of a wide range of vascular models. Here, we review platforms based on templated microvessel fabrication to generate increasingly complex vascular models of (i) the tumor microenvironment, (ii) occluded microvessels, and (iii) perfused capillary networks. We outline fabrication guidelines and demonstrate a number of experimental methods for probing vascular function such as permeability measurements, tumor cell intravasation, flow characterization, and endothelial cell morphology and proliferation.

Graphene Inks as Versatile Templates for Printing Tiled Metal Oxide Crystalline Films

There is great interest in exploiting van der Waals gaps in layered materials as confinement reaction vessels to template the synthesis of new nanosheet structures. The gallery spaces in multilayer graphene oxide, for example, can intercalate hydrated metal ions that assemble into metal oxide films during thermal oxidation of the sacrificial graphene template. This approach offers limited control of structure, however, and does not typically lead to 2D atomic-scale growth of anisotropic platelet crystals, but rather arrays of simple particles directionally sintered into porous sheets. Here, a new graphene-directed assembly route is demonstrated that yields fully dense, space-filling films of tiled metal oxide platelet crystals with tessellated structures. The method relies on colloidal engineering to produce a printable "metallized graphene ink" with accurate control of metal loading, grain size/porosity, composition, and micro/nanomorphologies, and is capable of achieving higher metal-carbon ratio than is possible by intercalation methods. These tiled structures are sufficiently robust to create free standing papers, complex microtextured films, 3D shapes, and metal oxide replicas of natural biotextures.

Prospective, Randomized, Surgeon-Blinded Comparison of Standard Magnification Assumption vs Magnification Marker Usage for Preoperative Templating in Total Hip Arthroplasty

BACKGROUND

We undertook this prospective, randomized, surgeon-blinded study to compare the accuracy of using of a magnification marker on preoperative radiographs for templating vs using a standard 21% magnification.

METHODS

One hundred consecutive total hip arthroplasties were randomized to preoperative templating using a 25-mm magnification marker (50 patients) or a standard 21% magnification (50 patients). Intraoperative data were collected regarding the actual and predicted size of the femoral and acetabular components.

RESULTS

The 2 groups were found to be comparable with respect to body mass index (28.9 vs 27.9, P = .26) and gender (P = .69). In the magnification marker group, we predicted the femoral size within 1 size in 80% of the cases and the acetabular component in 94%. In the group of a standard 21% magnification, we predicted the femoral size within 1 size in 90% of the cases and the acetabular component in 96%. These proportions did not statistically differ (femur: χ²P = .16, odds ratio = 2.3, 95% confidence interval = 0.7-7.1; acetabulum: χ²P = .65, odds ratio = 1.5, 95% confidence interval = 0.3-9.6).

CONCLUSION

We did not detect a statistically significant difference in accuracy by using one method over the other when comparing the accuracy of component size selection. As the use of the magnification marker adds to the time and expense of preoperative radiographic acquisition, we feel using a standard 21% magnification is an equally accurate technique.

Can Demographic Variables Accurately Predict Component Sizing in Primary Total Knee Arthroplasty?

BACKGROUND

As health care reform drives providers to reduce costs and improve efficiencies without compromising patient care, preoperative planning has become imperative. The purpose of this study is to determine whether height, weight, and gender can accurately predict total knee arthroplasty (TKA) sizing.

METHODS

A consecutive series of 3491 primary TKAs performed by 2 surgeons was reviewed. Height, weight, gender, implant, preoperative templating sizes, and final implant sizes were collected. Implant-specific dimensions were collected from vendors. Using height, weight, and gender, a multivariate linear regression was performed with and without the inclusion of preoperative templating. Accuracy of the model was reported for commonly used implants.

RESULTS

There was a significant linear correlation between height, weight, and gender for femoral (R² = 0.504; P < .001) and tibial sizes (R² = 0.610; P < .001). Adding preoperative templating to the regression analysis increased the overall model fit for both the femoral (R² = 0.756; P < .001) and tibial sizes (R² = 0.780; P < .001). Femoral and tibial sizes were accurately predicted within 1 size of the final implant 71%-92% and 81%-97% using demographics alone or 85%-99% and 90%-99% using both templating and demographics, respectively.

CONCLUSION

This novel TKA templating model allows final implants to be predicted to within 1 size. The model allows for simplified preoperative planning and potential implementation into a cost-savings program that limits inventory and trays required for each case.

Advances in 3D Modeling: Preoperative Templating for Revision Wrist Surgery

BACKGROUND

Three-dimensional (3D) printing is a computer-directed process leading to the layered synthesis of scaled models. The popularity and availability of the technique has exponentially increased over the last decade, and as such is seeing a greater number of medical and surgical applications.

METHODS

We report 3 cases involving the use of 3D printing as an aid to operative planning in the revision of wrist surgery.

RESULTS

All patients underwent successful operative interventions with a £34 average cost of model creation.

CONCLUSIONS

A growing number of reports are emerging in reconstructive surgical specialities including maxillofacial, orthopedic, and plastic surgery; from our experience, we advocate the economically viable use of 3D printing for preoperative templating.

Transcription of Nanofibrous Cerium Phosphate Using a pH-Sensitive Lipodipeptide Hydrogel Template

A novel and simple transcription strategy has been designed for the template-synthesis of CePO₄·xH₂O nanofibers having an improved nanofibrous morphology using a pH-sensitive nanofibrous hydrogel (glycine-alanine lipodipeptide) as structure-directing scaffold. The phosphorylated hydrogel was employed as a template to direct the mineralization of high aspect ratio nanofibrous cerium phosphate, which in-situ formed by diffusion of aqueous CeCl₃ and subsequent drying (60 °C) and annealing treatments (250, 600 and 900 °C). Dried xerogels and annealed CePO₄ powders were characterized by conventional thermal and thermogravimetric analysis (DTA/TG), and Wide-Angle X-ray powder diffraction (WAXD) and X-ray powder diffraction (XRD) techniques. A molecular packing model for the formation of the fibrous xerogel template was proposed, in accordance with results from Fourier-Transformed Infrarred (FTIR) and WAXD measurements. The morphology, crystalline structure and composition of CePO₄ nanofibers were characterized by electron microscopy techniques (Field-Emission Scanning Electron Microscopy (FE-SEM), Transmission Electron Microscopy/High-Resolution Transmission Electron Microscopy (TEM/HRTEM), and Scanning Transmission Electron Microscopy working in High Angle Annular Dark-Field (STEM-HAADF)) with associated X-ray energy-dispersive detector (EDS) and Scanning Transmission Electron Microscopy-Electron Energy Loss (STEM-EELS) spectroscopies. Noteworthy, this templating approach successfully led to the formation of CePO₄·H₂O nanofibrous bundles of rather co-aligned and elongated nanofibers (10⁻20 nm thick and up to ca. 1 μm long). The formed nanofibers consisted of hexagonal (P6₂22) CePO₄ nanocrystals (at 60 and 250 °C), with a better-grown and more homogeneous fibrous morphology with respect to a reference CePO₄ prepared under similar (non-templated) conditions, and transformed into nanofibrous monoclinic monazite (P21/n) around 600 °C. The nanofibrous morphology was highly preserved after annealing at 900 °C under N₂, although collapsed under air conditions. The nanofibrous CePO₄ (as-prepared hexagonal and 900 °C-annealed monoclinic) exhibited an enhanced UV photo-luminescent emission with respect to non-fibrous homologues.

Variance in predicted cup size by 2-dimensional vs 3-dimensional computerized tomography-based templating in primary total hip arthroplasty

Background

Preoperative total hip arthroplasty templating can be performed with radiographs using acetate prints, digital viewing software, or with computed tomography (CT) images. Our hypothesis is that 3D templating is more precise and accurate with cup size prediction as compared to 2D templating with acetate prints and digital templating software.

Methods

Data collected from 45 patients undergoing robotic-assisted total hip arthroplasty compared cup sizes templated on acetate prints and OrthoView software to MAKOplasty software that uses CT scan. Kappa analysis determined strength of agreement between each templating modality and the final size used. t tests compared mean cup-size variance from the final size for each templating technique. Interclass correlation coefficient (ICC) determined reliability of digital and acetate planning by comparing predictions of the operating surgeon and a blinded adult reconstructive fellow.

Results

The Kappa values for CT-guided, digital, and acetate templating with the final size was 0.974, 0.233, and 0.262, respectively. Both digital and acetate templating significantly overpredicted cup size, compared to CT-guided methods (P < .001). There was no significant difference between digital and acetate templating (P = .117). Interclass correlation coefficient value for digital and acetate templating was 0.928 and 0.931, respectively.

Conclusions

CT-guided planning more accurately predicts hip implant cup size when compared to the significant overpredictions of digital and acetate templating. CT-guided templating may also lead to better outcomes due to bone stock preservation from a smaller and more accurate cup size predicted than that of digital and acetate predictions.

Intricate Hollow Structures: Controlled Synthesis and Applications in Energy Storage and Conversion

Intricate hollow structures garner tremendous interest due to their aesthetic beauty, unique structural features, fascinating physicochemical properties, and widespread applications. Here, the recent advances in the controlled synthesis are discussed, as well as applications of intricate hollow structures with regard to energy storage and conversion. The synthetic strategies toward complex multishelled hollow structures are classified into six categories, including well-established hard- and soft-templating methods, as well as newly emerging approaches based on selective etching of "soft@hard" particles, Ostwald ripening, ion exchange, and thermally induced mass relocation. Strategies for constructing structures beyond multishelled hollow structures, such as bubble-within-bubble, tube-in-tube, and wire-in-tube structures, are also covered. Niche applications of intricate hollow structures in lithium-ion batteries, Li-S batteries, supercapacitors, Li-O₂ batteries, dye-sensitized solar cells, photocatalysis, and fuel cells are discussed in detail. Some perspectives on the future research and development of intricate hollow structures are also provided.

Spontaneous emergence of catalytic cycles with colloidal spheres

Colloidal particles endowed with specific time-dependent interactions are a promising route for realizing artificial materials that have the properties of living ones. Previous work has demonstrated how this system can give rise to self-replication. Here, we introduce the process of colloidal catalysis, in which clusters of particles catalyze the creation of other clusters through templating reactions. Surprisingly, we find that simple templating rules generically lead to the production of huge numbers of clusters. The templating reactions among this sea of clusters give rise to an exponentially growing catalytic cycle, a specific realization of Dyson's notion of an exponentially growing metabolism. We demonstrate this behavior with a fixed set of interactions between particles chosen to allow a catalysis of a specific six-particle cluster from a specific seven-particle cluster, yet giving rise to the catalytic production of a sea of clusters of sizes between 2 and 11 particles. The fact that an exponentially growing cycle emerges naturally from such a simple scheme demonstrates that the emergence of exponentially growing metabolisms could be simpler than previously imagined.

Oil-in-Water-in-Oil Multinanoemulsions for Templating Complex Nanoparticles

Complex nanoemulsions involving nanodroplets with a defined inner structure have great potential for encapsulation and templating applications. We report a method to form novel complex oil-in-water-in-oil nanoemulsions using a combination of high-energy processing with mixed nonionic surfactants that simultaneously achieve ultralow interfacial tension and frustrated curvature of the water-oil interface. The method produces multinanoemulsions possessing morphologies resembling water-swollen reverse vesicles with core-shell and multicore-shell morphologies of water in cyclohexane. A combination of macroscopic and microscopic characterization conclusively verifies and quantifies the complex morphologies, which vary systematically and reproducibly with water content for water volume fractions between 0.01 and 0.10. The complex morphologies are stable tens of hours, providing a route for their use as liquid templates for internally structured nanoparticles. As a demonstration, we test the complex nanoemulsions' ability to template complex polymer nanogels.

Nanometer-Scale Chemistry of a Calcite Biomineralization Template: Implications for Skeletal Composition and Nucleation

Plankton, corals, and other organisms produce calcium carbonate skeletons that are integral to their survival, form a key component of the global carbon cycle, and record an archive of past oceanographic conditions in their geochemistry. A key aspect of the formation of these biominerals is the interaction between organic templating structures and mineral precipitation processes. Laboratory-based studies have shown that these atomic-scale processes can profoundly influence the architecture and composition of minerals, but their importance in calcifying organisms is poorly understood because it is difficult to measure the chemistry of in vivo biomineral interfaces at spatially relevant scales. Understanding the role of templates in biomineral nucleation, and their importance in skeletal geochemistry requires an integrated, multiscale approach, which can place atom-scale observations of organic-mineral interfaces within a broader structural and geochemical context. Here we map the chemistry of an embedded organic template structure within a carbonate skeleton of the foraminifera Orbulina universa using both atom probe tomography (APT), a 3D chemical imaging technique with Ångström-level spatial resolution, and time-of-flight secondary ionization mass spectrometry (ToF-SIMS), a 2D chemical imaging technique with submicron resolution. We quantitatively link these observations, revealing that the organic template in O. universa is uniquely enriched in both Na and Mg, and contributes to intraskeletal chemical heterogeneity. Our APT analyses reveal the cation composition of the organic surface, offering evidence to suggest that cations other than Ca2+, previously considered passive spectator ions in biomineral templating, may be important in defining the energetics of carbonate nucleation on organic templates.

Guided Folding of Nematic Liquid Crystal Elastomer Sheets into 3D via Patterned 1D Microchannels

Two-dimensional liquid-crystal elastomer (LCE) sheets with preprogrammed topological defects are prepared by aligning liquid-crystal monomers within micropatterned epoxy channels, followed by photopolymerization. Upon heating, the LCE films form various three-dimensional structures in agreement with theoretical design. The miniaturized LCE actuators offer large-area work capacities (≈1.05 J m^-2 ) to lift over 700 times their own weight.

Polymer Capsules for Plaque-Targeted In Vivo Delivery

Targeted polymer capsules can selectively bind to unstable plaques in mice after intravenous injection. Different formulations of the capsules are explored with a synthetic/biopolymer hybrid capsule showing the best stability and small-molecule drug retention. The synthetic polymer is composed of pH-sensitive blocks (PDPA), low-binding blocks (PEG), and click-groups for postfunctionalization with targeting peptides specific to plaques.

Magnetostatic Interactions in Self-Assembled CoxNi1-xFe2O4/BiFeO3 Multiferroic Nanocomposites

Self-assembled vertically aligned oxide nanocomposites consisting of magnetic pillars embedded in a ferroelectric matrix have been proposed for logic devices made from arrays of magnetostatically interacting pillars. To control the ratio between the nearest neighbor interaction field and the switching field of the pillars, the pillar composition CoxNi1-xFe2O4 was varied over the range 0 ≤ x ≤ 1, which alters the magnetoelastic and magnetocrystalline anisotropy and the saturation magnetization. Nanocomposites were templated into square arrays of pillars in which the formation of a "checkerboard" ground state after ac-demagnetization indicated dominant magnetostatic interactions. The effect of switching field distribution in disrupting the antiparallel nearest neighbor configuration was analyzed using an Ising model and compared with experimental results.

Conformational Compatibility Is Essential for Heterologous Aggregation of α-Synuclein

Under aggregation-prone conditions, soluble amyloidogenic protein monomers can self-assemble into fibrils or they can fibrillize on preformed fibrillar seeds (seeded aggregation). Seeded aggregations are known to propagate the morphology of the seeds in the event of cross-seeding. However, not all proteins are known to cross-seed aggregation. Cross-seeding has been proposed to be restricted either because of differences in the protein sequences or because of conformations between the seeds and the soluble monomers. Here, we examine cross-seeding efficiency between three α-synuclein sequences, wild-type, A30P, and A53T, each varying in only one or two amino acids but forming morphologically distinct fibrils. Results from bulk Thioflavin-T measurements, monomer incorporation quantification, single fibril fluorescence microscopy, and atomic force microscopy show that under the given solution conditions conformity between the conformation of seeds and monomers is essential for seed elongation. Moreover, elongation characteristics of the seeds are defined by the type of seed.

One-Step Fabrication of Microchannels Lined with a Metal Oxide Coating

We demonstrate a simple, single-step method for metal/metal oxide coating on interior walls of microchannels in an elastomeric material like PDMS, which is the mainstay of microfluidic devices. The fabrication process involves electrodeposition of cuprous oxide on a metallic wire or a sheet, embedding it inside a PDMS matrix along with the cross-linker, curing and then swelling the PDMS elastomer, and finally pulling out the template metal wire or the metal sheet from the PDMS matrix. Stronger attachment of the metal oxide layer to PDMS allows the transfer of the metal oxide coating originally present on the template surface (wire or sheet) to the channel wall resulting in a microchannel/microslit lined with the metal/metal oxide layer. In view of the catalytic activity associated with transition metal oxides, this simple method offers a cost-effective and versatile technique to fabricate microfluidic and lab-on-a-chip devices which can be utilized as microcatalytic reactors or chemical filters. As a proof of concept, we have successfully tested the metal oxide coated microchannels and microslits as active sites for adsorption of iodide ions.

Calibration Marker Position in Digital Templating of Total Hip Arthroplasty

BACKGROUND

We report a mathematical method to assess the vertical and horizontal positions of spherical radiopaque objects of known size in conventional radiographs.

METHODS

The reliability and validity of the method were tested in an experimental setting and applied to 100 anteroposterior pelvic radiographs with external calibration markers and unilateral total hip arthroplasty (THA).

RESULTS

We found excellent reliabilities; intraclass correlation coefficients for interobserver and intraobserver reliabilities were 0.999-1.000 (P = .000). The mean normal height of THA was 198 mm (range: 142-243 mm, standard deviation: 18 mm) above the detector. Vertical and horizontal external marker positions differed significantly from the true hip center (THA; P < .001 and P = .017).

CONCLUSION

This method could enhance patient safety by enabling automated detection of malpositioned calibration markers by templating software.

Measuring the Femoral Head Size--An Additional Real-Time Intraoperative Monitoring Tool for the Accuracy of the Preoperative Process and Implant Selection

The purpose of this study was to examine the correlation between the implanted cup's outer diameter and the actual femoral head diameter removed during surgery. Seventy-five patients with primary total hip arthroplasty were evaluated. The difference between the implanted cup diameter and the femoral head diameter was calculated for each patient. The mean±SD actual femoral head diameter that was removed and measured during surgery was 48.5±3.7 mm. The mean±SD cementless implanted cup outer diameter was 51.8±3.5 mm. A high correlation was found between the implanted cup diameter and the actual femoral head diameter (r=0.923). A cut-off point of 4mm of the measured femoral head diameter should be considered as an additional monitoring indicator.