Achieving Complete Human Gingival Fibroblast Collagen Coverage on Implant Abutments through Vacuum Ultraviolet (VUV) Photofunctionalization.

PURPOSE: The formation of a biological seal between implant abutments and the surrounding soft tissue is a preventive strategy against peri-implantitis. The aim of this study is to test the hypothesis that surfaces of prosthetic implant abutments treated with vacuum ultraviolet (VUV) light enhance the growth and function of human gingival fibroblasts. MATERIALS AND METHODS: Implant abutments were treated with 172 nm VUV light for one minute. Untreated abutments were subjected as controls. Their surface properties were characterized using SEM, contact angle measurements, and chemical composition analysis. Human gingival fibroblasts were cultured on both untreated and VUV-treated abutments to evaluate cell attachment, proliferation, distribution, and collagen production. Cell detachment assays were also performed under various mechanical and chemical stimuli. RESULTS: After VUV treatment, implant abutments demonstrated a notable transition from hydrophobic to hydrophilic wettability. Surface element analysis revealed a considerable reduction in surface carbon and increases in oxygen and titanium elements on the VUV-treated surfaces. On day 1 of culture, 3.9 times more fibroblasts attached on VUV-treated abutments than on untreated control abutments. Fibroblastic proliferation increased 1.9-3.1 times on VUV-treated abutments, along with a significant improvement in the distribution of populating cells. Collagen production on VUV-treated abutments increased by 1.5-1.7 times. While untreated abutment surfaces showed voids and limited spread of collagen deposition, dense and full coverage of collagen was observed on VUV-treated abutments, with a great contrast in the challenging axial surface zone. Cell retention against mechanical and chemical detaching stimuli was increased 11.3 and 4.3 times, respectively, by VUV treatment. CONCLUSION: Treatment of implant abutments with VUV light for one minute resulted in a reduction of surface carbon and a transformation of the surface from hydrophobic to hydrophilic. This led to enhanced attachment, proliferation, and retention of human gingival fibroblasts, along with nearly complete collagen coverage on implant abutments. These in vitro results indicate the promising potential of utilizing VUV photofunctionalized implant abutments to enhance soft tissue reaction and sealing mechanisms.

Impact of increased trunk muscle mass on trunk function and activities of daily living in older individuals with cerebral infarction.

BACKGROUND & AIMS: The association between trunk muscle mass or trunk function or trunk muscle strength and activities of daily living (ADLs) has been reported, but no studies have examined the impact of increased trunk muscle mass on trunk function or ADL. This study aimed to determine whether increased trunk muscle mass is associated with trunk function and ADL in older individuals with cerebral infarction during rehabilitation. METHODS: This retrospective observational study enrolled 158 patients with cerebral infarction aged ≥65 years who were admitted for post-stroke rehabilitation. The trunk muscle mass index (TMI) was calculated at admission and discharge using bioelectrical impedance analysis. Patients were divided into two groups: one with increased TMI (64 participants; 41 %) and the other without TMI increase (94 participants; 59 %). Multiple linear regression analysis was performed with functional assessment for control of trunk (FACT) or functional independence measure (FIM)-motor gain as the objective variable and increased TMI group as the explanatory variable. RESULTS: We analyzed a total of 158 patients (79.5 ± 7.8 years of age, 51.9 % men). TMI increase was independently associated with FACT gain (coefficient = 1.413, 95 % confidence interval = 0.34-2.49, P = 0.010), but not with FIM-motor gain. CONCLUSIONS: The results suggest that increased TMI is independently associated with recovery of trunk function. Further prospective studies are needed to elucidate the relationship between increased TMI and ADL.

Calculation of trunk muscle mass and trunk muscle quality indices for walking independence in asian patients with hip fractures.

BACKGROUND & AIMS: This study aimed to investigate the association between trunk muscle mass and muscle quality, as evaluated by bioelectrical impedance analysis (BIA), and the ability to walk independently in patients with hip fractures. Cutoff values for quantitative and qualitative indicators of the trunk muscles were also calculated. METHODS: This study included 181 patients with hip fractures who were admitted to a convalescent rehabilitation ward. Trunk muscle mass and phase angle of the participants were evaluated on admission. The phase angle in this study was defined as the trunk muscle quality index (TMQI). Patients were classified into the independent (functional independence measure [FIM]-walk score ≥6; n = 101) and non-independent (FIM-walk score ≤5; n = 80) walking groups according to the FIM mobility scores at discharge. RESULTS: The independent group had a higher FIM gain than the non-independent group (37.0 ± 13.6 vs. 27.1 ± 13.5, p < 0.001). Logistic regression analysis showed that the trunk muscle mass index (TMI) and TMQI were associated with the ability to walk independently. Furthermore, cutoff values of TMI and TMQI for male and female to estimate the ability to walk independently were 6.5 kg/m2 and 5.7 kg/m2, and 4.5° and 3.4°, respectively. CONCLUSION: TMI and TMQI are related to the ability to walk independently in patients with hip fractures. These results suggest the importance of improving trunk muscle mass and muscle quality during rehabilitation of patients with hip fractures.

Machine learning-based gait analysis to predict clinical frailty scale in elderly patients with heart failure.

Aims: Although frailty assessment is recommended for guiding treatment strategies and outcome prediction in elderly patients with heart failure (HF), most frailty scales are subjective, and the scores vary among raters. We sought to develop a machine learning-based automatic rating method/system/model of the clinical frailty scale (CFS) for patients with HF. Methods and results: We prospectively examined 417 elderly (≥75 years) with symptomatic chronic HF patients from 7 centres between January 2019 and October 2023. The patients were divided into derivation (n = 194) and validation (n = 223) cohorts. We obtained body-tracking motion data using a deep learning-based pose estimation library, on a smartphone camera. Predicted CFS was calculated from 128 key features, including gait parameters, using the light gradient boosting machine (LightGBM) model. To evaluate the performance of this model, we calculated Cohen's weighted kappa (CWK) and intraclass correlation coefficient (ICC) between the predicted and actual CFSs. In the derivation and validation datasets, the LightGBM models showed excellent agreements between the actual and predicted CFSs [CWK 0.866, 95% confidence interval (CI) 0.807-0.911; ICC 0.866, 95% CI 0.827-0.898; CWK 0.812, 95% CI 0.752-0.868; ICC 0.813, 95% CI 0.761-0.854, respectively]. During a median follow-up period of 391 (inter-quartile range 273-617) days, the higher predicted CFS was independently associated with a higher risk of all-cause death (hazard ratio 1.60, 95% CI 1.02-2.50) after adjusting for significant prognostic covariates. Conclusion: Machine learning-based algorithms of automatically CFS rating are feasible, and the predicted CFS is associated with the risk of all-cause death in elderly patients with HF.

Human Gingival Fibroblast Growth and Function in Response to Laser-Induced Meso-and Microscale Hybrid Topography on Dental Implant Healing Abutments.

PURPOSE: Laser-created titanium surface topographies enhance soft tissue attachment and implant stability. However, knowledge about the underlying mechanisms governing the tissue-level reaction is lacking. The objective of this study was to examine the behavior and function of human gingival fibroblasts growing on healing abutments with or without laser-textured topography. MATERIALS AND METHODS: Human primary gingival connective tissue fibroblasts were cultured on healing abutments with machined or laser-textured (Laser-Lok, BioHorizons) surfaces. Cellular and molecular responses were evaluated by cell density assay (WST-1), fluorescence microscopy, qRT-PCR, and detachment test. RESULTS: The machined surface showed mono-directional traces and scratches from milling, whereas the laser-textured surface showed a distinct morphology consisting of mono-directional meso-scale channels (15 µm pitch) and woven, oblique micro-ridges formed within the channel. There were no differences in initial fibroblast attachment, subsequent fibroblast proliferation, nor collagen production between the machined and laser-textured surfaces. Fibroblasts growing on laser-textured surface spread mono-directionally along the meso-channels, while cells growing on machined surfaces spread randomly. Fibroblasts on laser-textured surfaces were 1.8-times more resistant to detachment than those on machined surfaces. An adhesive glycoprotein (fibronectin) and trans-membrane adhesion linker gene (integrin beta-1) were upregulated on laser-textured surfaces. CONCLUSIONS: The increased fibroblast retention, uniform growth, increased transcription of cell adhesion proteins compellingly explain the enhanced tissue-level response to laser-created, hybrid textured titanium surfaces. These results provide a cellular and molecular rationale for the tissue reaction to this unique surface and support its extended use from implant fixtures and healing abutments to diverse prosthetic components where enhanced soft tissue responses would be desirable.

Cold stress-induced ferroptosis in liver sinusoidal endothelial cells determines liver transplant injury and outcomes.

Although cold preservation remains the gold standard in organ transplantation, cold stress-induced cellular injury is a significant problem in clinical orthotopic liver transplantation (OLT). Because a recent study showed that cold stress activates ferroptosis, a form of regulated cell death, we investigated whether and how ferroptosis determines OLT outcomes in mice and humans. Treatment with ferroptosis inhibitor (ferrostatin-1) during cold preservation reduced lipid peroxidation (malondialdehyde; MDA), primarily in liver sinusoidal endothelial cells (LSECs), and alleviated ischemia/reperfusion injury in mouse OLT. Similarly, ferrostatin-1 reduced cell death in cold-stressed LSEC cultures. LSECs deficient in nuclear factor erythroid 2-related factor 2 (NRF2), a critical regulator of ferroptosis, were susceptible to cold stress-induced cell death, concomitant with enhanced endoplasmic reticulum (ER) stress and expression of mitochondrial Ca2+ uptake regulator (MICU1). Indeed, supplementing MICU1 inhibitor reduced ER stress, MDA expression, and cell death in NRF2-deficient but not WT LSECs, suggesting NRF2 is a critical regulator of MICU1-mediated ferroptosis. Consistent with murine data, enhanced liver NRF2 expression reduced MDA levels, hepatocellular damage, and incidence of early allograft dysfunction in human OLT recipients. This translational study provides a clinically applicable strategy in which inhibition of ferroptosis during liver cold preservation mitigates OLT injury by protecting LSECs from peritransplant stress via an NRF2-regulatory mechanism.

Text-Guided Image Editing Based on Post Score for Gaining Attention on Social Media.

Text-guided image editing has been highlighted in the fields of computer vision and natural language processing in recent years. The approach takes an image and text prompt as input and aims to edit the image in accordance with the text prompt while preserving text-unrelated regions. The results of text-guided image editing differ depending on the way the text prompt is represented, even if it has the same meaning. It is up to the user to decide which result best matches the intended use of the edited image. This paper assumes a situation in which edited images are posted to social media and proposes a novel text-guided image editing method to help the edited images gain attention from a greater audience. In the proposed method, we apply the pre-trained text-guided image editing method and obtain multiple edited images from the multiple text prompts generated from a large language model. The proposed method leverages the novel model that predicts post scores representing engagement rates and selects one image that will gain the most attention from the audience on social media among these edited images. Subject experiments on a dataset of real Instagram posts demonstrate that the edited images of the proposed method accurately reflect the content of the text prompts and provide a positive impression to the audience on social media compared to those of previous text-guided image editing methods.

Importance-aware adaptive dataset distillation.

Herein, we propose a novel dataset distillation method for constructing small informative datasets that preserve the information of the large original datasets. The development of deep learning models is enabled by the availability of large-scale datasets. Despite unprecedented success, large-scale datasets considerably increase the storage and transmission costs, resulting in a cumbersome model training process. Moreover, using raw data for training raises privacy and copyright concerns. To address these issues, a new task named dataset distillation has been introduced, aiming to synthesize a compact dataset that retains the essential information from the large original dataset. State-of-the-art (SOTA) dataset distillation methods have been proposed by matching gradients or network parameters obtained during training on real and synthetic datasets. The contribution of different network parameters to the distillation process varies, and uniformly treating them leads to degraded distillation performance. Based on this observation, we propose an importance-aware adaptive dataset distillation (IADD) method that can improve distillation performance by automatically assigning importance weights to different network parameters during distillation, thereby synthesizing more robust distilled datasets. IADD demonstrates superior performance over other SOTA dataset distillation methods based on parameter matching on multiple benchmark datasets and outperforms them in terms of cross-architecture generalization. In addition, the analysis of self-adaptive weights demonstrates the effectiveness of IADD. Furthermore, the effectiveness of IADD is validated in a real-world medical application such as COVID-19 detection.

Variations in predictors for urinary continence recovery at different time periods following robot-assisted radical prostatectomy.

INTRODUCTION: Urinary dysfunctions are common sequelae following prostatectomy. This study aimed to discover factors that can predict urinary continence recovery at various time periods after robot-assisted laparoscopic radical prostatectomy (RARP). METHODS: This was a retrospective analysis of data of 419 consecutive patients. Only patients followed up for ≥1 year were enrolled. An answer of "zero pad per day" in the Expanded Prostate Cancer Index Composite urinary assessment (question 5) denoted continence. Possible predictors of urinary continence recovery were evaluated at 3, 3-6, and 6-12 months after the operation. RESULTS: Continence rates at 3, 6, and 12 months after RARP were 12.9%, 21.2%, and 40.2%, respectively. The proportions of patients using 0-1 pad were 54.2%, 75.7%, and 83.1% at 3, 6, and 12 months after RARP, respectively. Multivariable regression analysis revealed that a membranous urethral length (MUL) ≥11 mm was significantly associated with urinary continence recovery both within 3 months (odds ratio: 0.367, P = .003) and 3-6 months (odds ratio: 0.354, P = .001) after RARP. The analysis also revealed that, in patients with urinary continence at 6 months, a large prostate volume (odds ratio: 1.973, P = .044) and a high body mass index (odds ratio: 2.874, P = .027) were negative predictors of urinary continence recovery within 6-12 months. CONCLUSION: A longer MUL was linked to urinary continence recovery within 6 months following RARP, whereas a large prostate volume and a high body mass index were adverse predictors of urinary continence recovery beyond 6 months.

Reduced Cross-Sectional Area of the Gluteus Medius Muscle is Associated With Decreased Activities of Daily Living in Older Adult Patients With Hip Fractures.

We investigated the association between the cross-sectional area (CSA) of the gluteus medius muscle (GMM) and activities of daily living in patients with hip fractures. This retrospective cohort study comprised 111 patients aged ≥65 years who underwent hip fracture rehabilitation. The CSA of the GMM was measured using computed tomography scans in the early stages of hospitalization. The group with decreased CSA of the GMM had a median GMI ≤17 cm2/m2 for male patients and ≤16 cm2/m2 for female patients. Patients in the group with decreased CSA of the GMM had lower functional independence measure gains than those in the control group. After adjusting for confounders, we found that decreased CSA of the GMM was significantly associated with lower functional independence measure gains (ß: -0.432, p < .001). In patients with hip fractures, decreased CSA of the GMM was associated with decreased activities of daily living.

Correlation between trunk function improvement and recovery of activities of daily living after stroke in older adult patients.

OBJECTIVES: To examine the impact of improved trunk function on activities of daily living in stroke patients using the Functional Independence Measure (FIM). METHODS: This retrospective observational study was conducted on patients aged ≥ 65 years who had cerebral infarction. Patients were divided into a group with improved trunk function and a group without trunk function improvement based on the difference between the calculated Functional Assessment for Control of Trunk (FACT) gain at discharge and admission. RESULTS: Of the 218 patients (mean age, 79.5 ± 7.9 years; 56.9% were men) included, 110 patients had improved FACT scores. Multiple linear regression analysis revealed that the group with improved FACT scores had higher FIM gain (coefficient = 7.562, 95% confidence interval = 3.870-11.253, P < 0.001). Multivariate logistic regression showed that the factors associated with FACT score improvement were the Mini Nutritional Assessment Short-Form score at admission, National Institutes of Health Stroke Scale score at admission, FACT score at admission, length of hospital stay, and period of rehabilitation. DISCUSSIONS: Improvement in trunk function suggests a positive correlation with the recovery of activities of daily living in patients with cerebral infarction. This relationship should be further validated through prospective observational studies.

Zero-Shot Traffic Sign Recognition Based on Midlevel Feature Matching.

Traffic sign recognition is a complex and challenging yet popular problem that can assist drivers on the road and reduce traffic accidents. Most existing methods for traffic sign recognition use convolutional neural networks (CNNs) and can achieve high recognition accuracy. However, these methods first require a large number of carefully crafted traffic sign datasets for the training process. Moreover, since traffic signs differ in each country and there is a variety of traffic signs, these methods need to be fine-tuned when recognizing new traffic sign categories. To address these issues, we propose a traffic sign matching method for zero-shot recognition. Our proposed method can perform traffic sign recognition without training data by directly matching the similarity of target and template traffic sign images. Our method uses the midlevel features of CNNs to obtain robust feature representations of traffic signs without additional training or fine-tuning. We discovered that midlevel features improve the accuracy of zero-shot traffic sign recognition. The proposed method achieves promising recognition results on the German Traffic Sign Recognition Benchmark open dataset and a real-world dataset taken from Sapporo City, Japan.

Synergistic Enhancement of Protein Recruitment and Retention via Implant Surface Microtopography and Superhydrophilicity in a Computational Fluid Dynamics Model.

The exact mechanisms by which implant surface properties govern osseointegration are incompletely understood. To gain insights into this process, we examined alterations in protein and blood recruitment around screw implants with different surface topographies and wettability using a computational fluid dynamics (CFD) model. Compared with a smooth surface, a microrough implant surface reduced protein infiltration from the outer zone to the implant thread and interface zones by over two-fold. However, the microrough implant surface slowed blood flow in the interface zone by four-fold. As a result, compared with the smooth surface, the microrough surface doubled the protein recruitment/retention index, defined as the mass of proteins present in the area per unit time. Converting implant surfaces from hydrophobic to superhydrophilic increased the mass of protein infiltration 2-3 times and slowed down blood flow by up to two-fold in the implant vicinity for both smooth and microrough surfaces. The protein recruitment/retention index was highest at the implant interface when the implant surface was superhydrophilic and microrough. Thus, this study demonstrates distinct control of the mass and speed of protein and blood flow through implant surface topography, wettability, and their combination, significantly altering the efficiency of protein recruitment. Although microrough surfaces showed both positive and negative impacts on protein recruitment over smooth surfaces, superhydrophilicity was consistently positive regardless of surface topography.

Vacuum Ultraviolet (VUV) Light Photofunctionalization to Induce Human Oral Fibroblast Transmigration on Zirconia.

Soft tissue adhesion and sealing around dental and maxillofacial implants, related prosthetic components, and crowns are a clinical imperative to prevent adverse outcomes of periodontitis and periimplantitis. Zirconia is often used to fabricate implant components and crowns. Here, we hypothesized that UV treatment of zirconia would induce unique behaviors in fibroblasts that favor the establishment of a soft tissue seal. Human oral fibroblasts were cultured on zirconia specimens to confluency before placing a second zirconia specimen (either untreated or treated with one minute of 172 nm vacuum UV (VUV) light) next to the first specimen separated by a gap of 150 µm. After seven days of culture, fibroblasts only transmigrated onto VUV-treated zirconia, forming a 2.36 mm volume zone and 5.30 mm leading edge. Cells migrating on VUV-treated zirconia were enlarged, with robust formation of multidirectional cytoplastic projections, even on day seven. Fibroblasts were also cultured on horizontally placed and 45° and 60° tilted zirconia specimens, with the latter configurations compromising initial attachment and proliferation. However, VUV treatment of zirconia mitigated the negative impact of tilting, with higher tilt angles increasing the difference in cellular behavior between control and VUV-treated specimens. Fibroblast size, perimeter, and diameter on day seven were greater than on day one exclusively on VUV-treated zirconia. VUV treatment reduced surface elemental carbon and induced superhydrophilicity, confirming the removal of the hydrocarbon pellicle. Similar effects of VUV treatment were observed on glazed zirconia specimens with silica surfaces. One-minute VUV photofunctionalization of zirconia and silica therefore promotes human oral fibroblast attachment and proliferation, especially under challenging culture conditions, and induces specimen-to-specimen transmigration and sustainable photofunctionalization for at least seven days.

Manipulation Direction: Evaluating Text-Guided Image Manipulation Based on Similarity between Changes in Image and Text Modalities.

At present, text-guided image manipulation is a notable subject of study in the vision and language field. Given an image and text as inputs, these methods aim to manipulate the image according to the text, while preserving text-irrelevant regions. Although there has been extensive research to improve the versatility and performance of text-guided image manipulation, research on its performance evaluation is inadequate. This study proposes Manipulation Direction (MD), a logical and robust metric, which evaluates the performance of text-guided image manipulation by focusing on changes between image and text modalities. Specifically, we define MD as the consistency of changes between images and texts occurring before and after manipulation. By using MD to evaluate the performance of text-guided image manipulation, we can comprehensively evaluate how an image has changed before and after the image manipulation and whether this change agrees with the text. Extensive experiments on Multi-Modal-CelebA-HQ and Caltech-UCSD Birds confirmed that there was an impressive correlation between our calculated MD scores and subjective scores for the manipulated images compared to the existing metrics.

Genome-wide transcriptional responses of osteoblasts to different titanium surface topographies.

This is the first genome-wide transcriptional profiling study using RNA-sequencing to investigate osteoblast responses to different titanium surface topographies, specifically between machined, smooth and acid-etched, microrough surfaces. Rat femoral osteoblasts were cultured on machine-smooth and acid-etched microrough titanium disks. The culture system was validated through a series of assays confirming reduced osteoblast attachment, slower proliferation, and faster differentiation on microrough surfaces. RNA-sequencing analysis of osteoblasts at an early stage of culture revealed that gene expression was highly correlated (r = 0.975) between the two topographies, but 1.38 % genes were upregulated and 0.37 % were downregulated on microrough surfaces. Upregulated transcripts were enriched for immune system, plasma membrane, response to external stimulus, and positive regulation to stimulus processes. Structural mapping confirmed microrough surface-promoted gene sharing and networking in signaling pathways and immune system/responses. Target-specific pathway analysis revealed that Rho family G-protein signaling pathways and actin genes, responsible for the formation of stress fibers, cytoplasmic projections, and focal adhesion, were upregulated on microrough surfaces without upregulation of core genes triggered by cell-to-cell interactions. Furthermore, disulfide-linked or -targeted extracellular matrix (ECM) or membranous glycoproteins such as laminin, fibronectin, CD36, and thrombospondin were highly expressed on microrough surfaces. Finally, proliferating cell nuclear antigen (PCNA) and cyclin D1, whose co-expression reduces cell proliferation, were upregulated on microrough surfaces. Thus, osteoblasts on microrough surfaces were characterized by upregulation of genes related to a wide range of functions associated with the immune system, stress/stimulus responses, proliferation control, skeletal and cytoplasmic signaling, ECM-integrin receptor interactions, and ECM-membranous glycoprotein interactions, furthering our knowledge of the surface-dependent expression of osteoblastic biomarkers on titanium.

Relationship between Trunk Muscle Mass Index at Admission and Walking Independence in Patients with Hip Fracture.

Objectives: This study aimed to investigate the relationship between trunk muscle mass index (TMI), appendicular skeletal muscle mass index (ASMI), and walking independence in patients aged 65 years and older undergoing rehabilitation for hip fracture. Methods: This retrospective, observational study was conducted in a convalescent rehabilitation ward and included 314 patients (aged ≥65 years) with hip fracture. The patients were classified into the independence group [functional independence measure (FIM)-walk score ≥6] or the non-independence group (FIM-walk score ≤5) according to the mobility item score among the motor FIM items at the time of discharge. Age, sex, TMI, ASMI, and Mini Nutritional Assessment-Short Form (MNA-SF) data were also extracted. Between-group and multivariate analyses were performed to evaluate the factors associated with walking independence. Results: The independence group had higher TMI (males: 6.6±0.9 vs. 5.6±1.0 kg/m2, P <0.001; females: 6.1±0.8 vs. 5.7±1.0 kg/m2, P <0.001), ASMI (males: 6.7±1.1 vs. 5.9±1.3 kg/m2, P=0.004; females: 5.3±0.9 vs. 4.7±0.8 kg/m2, P <0.001), MMSE-J (21.5±4.9 vs. 16.4±4.5 points, P <0.001), and MNA-SF [median (interquartile range): 8 (6-9) vs. 7 (5-8) points, P <0.001] than the non-independence group. Multivariate analysis showed that TMI at admission was significantly associated with walking independence (odds ratio: 1.86, 95% confidence interval: 1.28-2.72, P <0.001). Conclusions: This study suggests that a higher TMI at admission was important for acquiring walking independence in patients with hip fracture and shows the importance of early evaluation of TMI during hospitalization of patients with hip fracture.

Influence of Surface Contaminants and Hydrocarbon Pellicle on the Results of Wettability Measurements of Titanium.

Hydrophilicity/hydrophobicity-or wettability-is a key surface characterization metric for titanium used in dental and orthopedic implants. However, the effects of hydrophilicity/hydrophobicity on biological capability remain uncertain, and the relationships between surface wettability and other surface parameters, such as topography and chemistry, are poorly understood. The objective of this study was to identify determinants of surface wettability of titanium and establish the reliability and validity of the assessment. Wettability was evaluated as the contact angle of ddH2O. The age of titanium specimens significantly affected the contact angle, with acid-etched, microrough titanium surfaces becoming superhydrophilic immediately after surface processing, hydrophobic after 7 days, and hydrorepellent after 90 days. Similar age-related loss of hydrophilicity was also confirmed on sandblasted supra-micron rough surfaces so, regardless of surface topography, titanium surfaces eventually become hydrophobic or hydrorepellent with time. On age-standardized titanium, surface roughness increased the contact angle and hydrophobicity. UV treatment of titanium regenerated the superhydrophilicity regardless of age or surface roughness, with rougher surfaces becoming more superhydrophilic than machined surfaces after UV treatment. Conditioning titanium surfaces by autoclaving increased the hydrophobicity of already-hydrophobic surfaces, whereas conditioning with 70% alcohol and hydrating with water or saline attenuated pre-existing hydrophobicity. Conversely, when titanium surfaces were superhydrophilic like UV-treated ones, autoclaving and alcohol cleaning turned the surfaces hydrorepellent and hydrophobic, respectively. UV treatment recovered hydrophilicity without exception. In conclusion, surface roughness accentuates existing wettability and can either increase or decrease the contact angle. Titanium must be age-standardized when evaluating surface wettability. Surface conditioning techniques significantly but unpredictably affect existing wettability. These implied that titanium wettability is significantly influenced by the hydrocarbon pellicle and other contaminants inevitably accumulated. UV treatment may be an effective strategy to standardize wettability by making all titanium surfaces superhydrophilic, thereby allowing the characterization of individual surface topography and chemistry parameters in future studies.

The Effects of a Biomimetic Hybrid Meso- and Nano-Scale Surface Topography on Blood and Protein Recruitment in a Computational Fluid Dynamics Implant Model.

The mechanisms underlying bone-implant integration, or osseointegration, are still incompletely understood, in particular how blood and proteins are recruited to implant surfaces. The objective of this study was to visualize and quantify the flow of blood and the model protein fibrinogen using a computational fluid dynamics (CFD) implant model. Implants with screws were designed with three different surface topographies: (1) amorphous, (2) nano-trabecular, and (3) hybrid meso-spikes and nano-trabeculae. The implant with nano-topography recruited more blood and fibrinogen to the implant interface than the amorphous implant. Implants with hybrid topography further increased recruitment, with particularly efficient recruitment from the thread area to the interface. Blood movement significantly slowed at the implant interface compared with the thread area for all implants. The blood velocity at the interface was 3- and 4-fold lower for the hybrid topography compared with the nano-topography and amorphous surfaces, respectively. Thus, this study for the first time provides insights into how different implant surfaces regulate blood dynamics and the potential advantages of surface texturization in blood and protein recruitment and retention. In particular, co-texturization with a hybrid meso- and nano-topography created the most favorable microenvironment. The established CFD model is simple, low-cost, and expected to be useful for a wide range of studies designing and optimizing implants at the macro and micro levels.

Zero-Shot Neural Decoding with Semi-Supervised Multi-View Embedding.

Zero-shot neural decoding aims to decode image categories, which were not previously trained, from functional magnetic resonance imaging (fMRI) activity evoked when a person views images. However, having insufficient training data due to the difficulty in collecting fMRI data causes poor generalization capability. Thus, models suffer from the projection domain shift problem when novel target categories are decoded. In this paper, we propose a zero-shot neural decoding approach with semi-supervised multi-view embedding. We introduce the semi-supervised approach that utilizes additional images related to the target categories without fMRI activity patterns. Furthermore, we project fMRI activity patterns into a multi-view embedding space, i.e., visual and semantic feature spaces of viewed images to effectively exploit the complementary information. We define several source and target groups whose image categories are very different and verify the zero-shot neural decoding performance. The experimental results demonstrate that the proposed approach rectifies the projection domain shift problem and outperforms existing methods.