New Insight Into the Mechanism of Ecological Effects of Artificial Habitats: Elucidating the Relationship Between Protists Associated With Artificial Reefs and Adjacent Seawater

Artificial habitat deployment can restore natural habitats or supplement existing natural habitats. The effect of resource proliferation and protection is obvious. However, few reports have addressed the biological community association between artificial habitats and adjacent environments. Here, Illumina sequencing of 18S rDNA was performed, and the diversity, community structure, and co-occurrence networks of protists in different layers of artificial reefs (ARs) and adjacent seawater (WAR) were described to verify that constructing ARs in Bailong Pearl Bay improves local spatial heterogeneity and functional diversity. In terms of the degree of species interaction, the protist communities were ranked as follows: surface and bottom of WAR > ARs and WAR > different layers of ARs. The α-diversity of protists associated with ARs and WAR decreased with an increase in depth. Protist diversity was greater in WAR than in ARs. β-Diversity analysis revealed significant differences in protist community structure between WAR and ARs (P < 0.05), and the upper layers of ARs and the middle or bottom layers of ARs differed. The key topological features of protist networks showed more positive interspecific interactions in the AR-associated protist community, a higher degree of niche differentiation, and higher complexity and stability. The keystone protists in the bottom seawater layer displayed community functions that were biased toward initial fixation in the ocean carbon cycle. The AR-associated protist community tended to participate in carbon transfer in the food chain and decomposition and utilization of dissolved organic matter (DOM). This study revealed significant differences in protist community structure between ARs and the adjacent environment, and the ecological functions of the key phyla were found to be related. In conclusion, protist communities in WAR may provide food sources for AR-associated heterotrophic protists. A variety of key phyla associated with ARs have biological roles in the carbon pump via their ecological characteristics.

Early fixation of the humeral component in stemless total shoulder arthroplasty

Aims Stemless humeral implants have been developed to overcome stem-related complications in total shoulder arthroplasty (TSA). However, stemless implant designs may hypothetically result in less stable initial fixation, potentially affecting long-term survival. The aim of this study is to investigate early fixation and migration patterns of the stemless humeral component of the Simpliciti Shoulder System and to evaluate clinical outcomes. Methods In this prospective cohort study, radiostereometric analysis (RSA) radiographs were obtained in 24 patients at one day, six weeks, six months, one year, and two years postoperatively. Migration was calculated using model-based RSA. Clinical outcomes were evaluated using the visual analogue scale (VAS), the Oxford Shoulder Score (OSS), the Constant-Murley Score (CMS), and the Disabilities of the Arm, Shoulder and Hand (DASH) score. Results At two years, median translation along the x-, y-, and z-axis was -0.12 mm (interquartile range (IQR) -0.18 to 0.02), -0.17 mm (IQR -0.27 to -0.09), and 0.09 mm (IQR 0.02 to 0.31). Median rotation around the x-, y-, and z-axis was 0.12° (IQR -0.50 to 0.57), -0.98° (IQR -1.83 to 1.23), and 0.09° (IQR -0.76 to 0.30). Overall, 20 prostheses stabilized within 12 months postoperatively. Four prostheses showed continuous migration between 12 and 24 months. At two-year follow-up, with the exception of one revised prosthesis, all clinical scores improved significantly (median VAS difference at rest: -3.0 (IQR -1.5 to -6.0); OSS 22.0 (IQR 15.0 to 25.0); CMS 29.5 (IQR 15.0 to 35.75); and DASH -30.0 (IQR -20.6 to -41.67) (all p < 0.001)) with the exception of one revised prosthesis. Conclusion In conclusion, we found that 20 out of 24 implants stabilized within 12 months postoperatively. The significance of continuous migration in four implants is unclear and future research on the predictive value of early migration for future loosening in TSA is required. Clinical results revealed a clinically relevant improvement. Cite this article: Bone Joint J 2022;104-B(1):76–82.

Volar Lunate Facet Rim Fractures: K-I Classification and Technique

Background and Purpose It is difficult to capture and safely support a small volar lunate facet (VLF) fragment and obtain sufficient initial fixation. The challenge in treating VLF rim fractures has resulted in various management options. The purpose of this study was to evaluate the clinical and radiological outcomes of a consecutive series of VLF rim fractures of the distal radius treated surgically and to report the Kondo–Imatani (K-I) classification of these fractures, using computed tomography (CT) images and surgical technique, which is termed the Plate buttress and Double tiered subchondral support (PD) technique. Patients and Methods A retrospective review was conducted on 35 patients with VLF rim fractures that included postoperative clinical evaluations, CT images, and radiographs. Description of Technique The PD technique to stabilize the VLF fragment with an anatomical and low-profile volar locking plate (VLP). Results All fractures healed at the final follow-up; Mayo wrist performance score average was 81.7 points (45–100), and the quick disabilities of the arm, shoulder, and hand (quick-DASH) score average was 9.5 points (0–31.8), showing relatively good clinical results. Conclusion VLF rim fragments are not amenable to standard VLP fixation. Unstable fixation may result in postoperative correction loss, aseptic necrosis, malunion, radiocarpal subluxation, and wrist dysfunction. This report described the K-I classification for VLF rim fractures of the distal radius and surgical technique, termed the PD technique, to stabilize the VLF rim fragment with an anatomical and low-profile VLP. Level of Evidence This is a Level IV, case series study.

Treatment of FRI after intramedullary nailing of tibia fractures: assessment of nail retention and nail removal

Objectives: Fracture related infection (FRI) is a severe, potentially limb-threatening complication after fracture fixation. Dilemma exists with regard to removing or retaining implants while treating the infection. The purpose of this study was to compare primary bone union and infection clearance in patients who had an infection following intramedullary nailing of the tibia treated either by retaining the implant or by removing the implant. Methods: Patients from two level-I trauma centers were identified through billing registries and retrospectively reviewed between January 2013 and December 2020. We identified 44 patients who had a diagnosis of FRI within 90 days of their initial fixation and returned to the OR for operative treatment of the infection. The incidences of both primary union and infection clearance were calculated for both groups and multiple parameters that may be associated with success or failure were assessed. Results: Four patients did not have complete records and were excluded. Of the remaining patients, 20 (50%) achieved infection clearance. Twenty-three (59%) patients achieved primary union whereas 16 (41%) had a primary outcome of either delayed union, nonunion, or amputation (one additional patient excluded as healing status unknown). Further analysis showed no significant difference (X2 (39) = 1.13, p < .29) in infection clearance between patients treated with nail retention (64%) versus nail removal (68%). No significant difference was seen in primary bone union (X2 (39) = 3.24, p < .07) with 36% of patients treated with nail retention and 68% of patients treated with nail removal reaching primary union; however, this does trend toward an association. Fewer surgeries performed for infection and complication after initial fixation was positively associated with infection clearance (p < .04, M=4.6, SD=2.13, df=39) and primary union (p < .001, M=4, SD=2, df=38). Conclusion: Infection clearance seems similarly possible with both nail retention and nail removal strategies, with fewer number of surgeries performed for infection and complication improving the likelihood of infection clearance and bone union. This may suggest that more severe FRI’s are less likely to unite and clear infection. Nail removal may play a role in increasing primary bone union; however, a larger sample size is needed for more definitive assessment.

Biomechanical Comparison of Anatomic Restoration of the Ulnar Footprint vs Traditional Ulnar Tunnels in Ulnar Collateral Ligament Reconstruction

Background: Current techniques for ulnar collateral ligament (UCL) reconstruction do not reproduce the anatomic ulnar footprint of the UCL. The purpose of this study was to describe a novel UCL reconstruction technique that utilizes proximal-to-distal ulnar bone tunnels to better re-create the anatomy of the UCL and to compare the biomechanical profile at time zero among this technique, the native UCL, and the traditional docking technique. Hypothesis: The biomechanical profile of the anatomic technique is similar to the native UCL and traditional docking technique. Study Design: Controlled laboratory study. Methods: Ten matched cadaveric elbows were potted with the forearm in neutral rotation. The palmaris longus tendon graft was harvested, and bones were sectioned 14 cm proximal and distal to the elbow joint. Specimen testing included (1) native UCL testing performed at 90° of flexion with 0.5 N·m of valgus moment preload, (2) cyclic loading from 0.5 to 5 N·m of valgus moment for 1000 cycles at 1 Hz, and (3) load to failure at 0.2 mm/s. Elbows then underwent UCL reconstruction with 1 elbow of each pair receiving the classic docking technique using either anatomic (proximal to distal) or traditional (anterior to posterior) tunnel locations. Specimen testing was then repeated as described. Results: There were no differences in maximum load at failure between the anatomic and traditional tunnel location techniques (mean ± SD, 34.90 ± 10.65 vs 37.28 ± 14.26 N·m; P = .644) or when including the native UCL (45.83 ± 17.03 N·m; P = .099). Additionally, there were no differences in valgus angle after 1000 cycles across the anatomic technique (4.58°± 1.47°), traditional technique (4.08°± 1.28°), and native UCL (4.07°± 1.99°). The anatomic group and the native UCL had similar valgus angles at failure (24.13°± 5.86° vs 20.13°± 5.70°; P = .083), while the traditional group had a higher valgus angle at failure when compared with the native UCL (24.88°± 6.18° vs 19.44°± 5.86°; P = .015). Conclusion: In this cadaveric model, UCL reconstruction with the docking technique utilizing proximal-to-distal ulnar tunnels better restored the ulnar footprint while providing valgus stability comparable with reconstruction with the docking technique using traditional anterior-to-posterior ulnar tunnel locations. These results suggest that utilization of the anatomic tunnel location in UCL reconstruction has similar biomechanical properties to the traditional method at the time of initial fixation (ie, not accounting for healing after reconstruction in vivo) while keeping the ulnar tunnels farther from the ulnar nerve. Further studies are warranted to determine if an anatomically based UCL reconstruction results in differing outcomes than traditional reconstruction techniques. Clinical Relevance: Current UCL reconstruction techniques do not accurately re-create the ulnar UCL footprint. The UCL is a dynamic constraint to valgus loads at the elbow, and a more anatomic reconstruction may afford more natural joint kinematics. This more anatomic technique performs similarly to the traditional docking technique at time zero, and the results of this study may offer a starting point for future in vivo studies.

Graphological and semantic foregrounding as affecting gaze and speech of impulsive and reflective readers

The study explores the effects of graphological and semantic foregrounding on speech and gaze behavior in textual information construal of subjects with higher and lower impulsivity. Eye movements of sixteen participants were recorded as they read drama texts with interdiscourse switching (semantic foregrounding), with features of typeface distinct from the surrounding text (graphological foregrounding). Discourse modification patterns were analyzed and processed in several steps: specification of participant/object/action/event/perspective modification, parametric annotation of participants’ discourse responses, contrastive analysis of modification parameter activity and parameter synchronized activity. Significant distinctions were found in eye movement parameters (gaze count and initial fixation duration) in subjects with higher and lower impulsivity when reading parts of text with graphical foregrounding. Impulsive subjects tended to visit the areas more often with longer initial fixations than reflective subjects, which is explained in terms of stimulus-driven attention, associated with bottom-up processes. However, these differences in gaze behavior did not result in pronounced distinctions in discourse responses, which were only slightly mediated by impulsivity/reflectivity.

Foveal processing of emotion-informative facial features

Certain facial features provide useful information for recognition of facial expressions. In two experiments, we investigated whether foveating informative features of briefly presented expressions improves recognition accuracy and whether these features are targeted reflexively when not foveated. Angry, fearful, surprised, and sad or disgusted expressions were presented briefly at locations which would ensure foveation of specific features. Foveating the mouth of fearful, surprised and disgusted expressions improved emotion recognition compared to foveating an eye or cheek or the central brow. Foveating the brow led to equivocal results in anger recognition across the two experiments, which might be due to the different combination of emotions used. There was no consistent evidence suggesting that reflexive first saccades targeted emotion-relevant features; instead, they targeted the closest feature to initial fixation. In a third experiment, angry, fearful, surprised and disgusted expressions were presented for 5 seconds. Duration of task-related fixations in the eyes, brow, nose and mouth regions was modulated by the presented expression. Moreover, longer fixation at the mouth positively correlated with anger and disgust accuracy both when these expressions were freely viewed (Experiment 2b) and when briefly presented at the mouth (Experiment 2a). Finally, an overall preference to fixate the mouth across all expressions correlated positively with anger and disgust accuracy. These findings suggest that foveal processing of informative features is functional/contributory to emotion recognition, but they are not automatically sought out when not foveated, and that facial emotion recognition performance is related to idiosyncratic gaze behaviour.

Coating Characteristic of Hydroxyapatite on Titanium Substrates via Hydrothermal Treatment

Medical pure titanium (Ti) shows excellent chemical stability and mechanical properties in clinical uses, but its initial fixation with host bone, when implanted, is usually delayed owing to the bioinert Ti surface. In this study, we fabricate the hydroxyapatite (HA)-coated titanium by three steps reactions: (1) to form an activated O2− layer by immersing Ti substrate into an alkaline solution such as NaOH; (2) the O2− bonds with Ca2+ to form Ca–O–Ti bonding, in which O plays the part of bridge materials between Ca and Ti substrate and (3) the conversion of Ca–O–Ti samples to HA-coated Ti samples by immersion into Na2HPO4 2 M at 180 °C for 48 h using hydrothermal methods. The effect of different phosphate solutions (NaH2PO4 2 M and Na2HPO4 2 M solution) and hydrothermal treatment time (24 and 48 h) on the characteristic of hydroxyapatite coating titanium substrate is also investigated using the optical microscope, thin film XRD and SEM/EDX. The HA-coated Ti samples fabricated by immersion into Na2HPO4 2 M at 180 °C for 48 h show fiber HA covering Titan substrate with a diameter varying from 0.1 to 0.3 µm. These HA-coated Ti samples can be regarded as promising multifunctional biomaterials.

Differential Expression, Tissue-Specific Distribution, and Posttranslational Controls of Phosphoenolpyruvate Carboxylase

Phosphoenolpyruvate carboxylase (PEPC) is a ubiquitous cytosolic enzyme, which is crucial for plant carbon metabolism. PEPC participates in photosynthesis by catalyzing the initial fixation of atmospheric CO2 and is abundant in both C4 and crassulacean acid metabolism leaves. PEPC is differentially expressed at different stages of plant development, mostly in leaves, but also in developing seeds. PEPC is known to show tissue-specific distribution in leaves and in other plant organs, such as roots, stems, and flowers. Plant PEPC undergoes reversible phosphorylation and monoubiquitination, which are posttranslational modifications playing important roles in regulatory processes and in protein localization. Phosphorylation activates the PEPC enzyme, making it more sensitive to glucose-6-phosphate and less sensitive to malate or aspartate. PEPC phosphorylation is known to be diurnally regulated and delicately changed in response to various environmental stimuli, in addition to light. PEPCs belong to a small gene family encoding several plant-type and distantly related bacterial-type PEPCs. This paper provides a minireview of the general information on PEPCs in both C4 and C3 plants.

The Foreground Bias: Initial Scene Representations Across the Depth Plane

When you walk into a large room, you perceive visual information that is both close to you in depth and farther in the background. Here, we investigated how initial scene representations are affected by information across depth. We examined the role of background and foreground information on scene gist by using chimera scenes (images with a foreground and background from different scene categories). Across three experiments, we found a foreground bias: Information in the foreground initially had a strong influence on the interpretation of the scene. This bias persisted when the initial fixation position was on the scene background and when the task was changed to emphasize scene information. We concluded that the foreground bias arises from initial processing of scenes for understanding and suggests that scene information closer to the observer is initially prioritized. We discuss the implications for theories of scene and depth perception.