Virtual Reality Simulation of Airway Management Post-Cleft Palate Surgery: A Model for Sustainable and Equitable Education.

BACKGROUND: The effectiveness of virtual-reality (VR) simulation-based training in cleft surgery has not been tested. The purpose of this study was to evaluate learners' acceptance of VR simulation in airway management of a pediatric patient post-cleft palate repair. METHODS: This VR simulation was developed through collaboration between BioDigital and Smile Train. 26 medical students from a single institution completed 10 min of standardized VR training and 5 min of standardized discussion about airway management post-cleft palate repair. They spent 4-8 min in the VR simulation with guidance from a cleft surgery expert. Participants completed pre- and post-surveys evaluating confidence in using VR as an educational tool, understanding of airway management, and opinions on VR in surgical education. Satisfaction was evaluated using a modified Student Evaluation of Educational Quality questionnaire and scored on a 5-point Likert scale. Wilcoxon signed-rank tests were performed to evaluate responses. RESULTS: There was a significant increase in respondents' confidence using VR as an educational tool and understanding of airway management post-cleft palate repair after the simulation (P < .001). Respondents' opinions on incorporating VR in surgical education started high and did not change significantly post-simulation. Participants were satisfied with VR-based simulation and reported it was stimulating (4.31 ± 0.88), increased interest (3.77 ± 1.21), enhanced learning (4.12 ± 1.05), was clear (4.15 ± 0.97), was effective in teaching (4.08 ± 0.81), and would recommend the simulation (4.2 ± 1.04). CONCLUSION: VR-based simulation can significantly increase learners' confidence and skills in airway management post-cleft palate repair. Learners find VR to be effective and recommend its incorporation in surgical education.

Bilateral Cleft lip Simulation.

OBJECTIVE: To evaluate the features, anatomic accuracy, and educational value of a high-fidelity bilateral cleft lip simulator. DESIGN: Evaluation of the simulator by expert cleft surgeons after performing a simulated bilateral cleft lip repair. SETTING: The simulator was evaluated by the surgeons during the Latin American Craniofacial Association meeting. PARTICIPANTS: Eleven experienced cleft surgeons evaluated the simulator. The cleft surgeons were selected based on their availability during the meeting. INTERVENTIONS: The participants performed a simulated bilateral cleft lip repair. They were each provided with a questionnaire assessing the simulator's features, realism and value as a training tool. MAIN OUTCOME MEASURE (S): The main outcome measure are the scores obtained from a Likert-type questionnaire assessing the simulators features, realism and value. RESULTS: Overall, the surgeons agreed with the simulator's realism and anatomic accuracy (average score of 3.7 out of 5). Overall, the surgeons strongly agreed with the value of the simulator as a training tool (average score of 4.6 out of 5). CONCLUSIONS: A high-fidelity bilateral cleft lip simulator was developed that is realistic and valuable as a training tool. The simulator provides a comprehensive training platform to gain hands-on experience in bilateral cleft lip repair before operating on real patients.

Internet-based Digital Simulation for Cleft Surgery Education: A 10-year Assessment of Demographics, Usage, and Future Directions.

Background: In October 2012, an open-access, multimedia digital cleft simulator was released. Its purpose was to address global disparities in cleft surgery education, providing an easily accessible surgical atlas for trainees globally. The simulator platform includes a three-dimensional surgical simulation of cleft care procedures, intraoperative videos, and voiceover. This report aims to assess the simulator's demographics and usage in its tenth year since inception. Finally, we also aim to understand the traction of virtual reality in cleft surgical education. Methods: Usage data of the simulator over 10 years were retrospectively collected and analyzed. Data parameters included the number of users, sessions, countries reached, and content access. An electronic survey was emailed to registered users to assess the benefits of the simulator. Results: The total number of new and active simulator users reached 7687 and 12,042. The simulator was accessed an average of 172.9.0 ± 197.5 times per month. Low- to middle-income regions accounted for 43% of these sessions. The mean session duration was 11.4 ± 6.3 minutes, yielding a total screen time of 3022 hours. A total of 331 individuals responded to the survey, of whom 80.8% found the simulator to be very useful or extremely useful. Of those involved in education, 45.0% implemented the simulator as a teaching tool. Conclusions: Global utilization of the simulator has been sustained after 10 years from inception with an increased presence in low- to middle-income nations. Future similar surgical simulators may provide sustainable training platforms to surgeons in low- and high-resource areas.

Hyaluronic acid-British anti-Lewisite as a safer chelation therapy for the treatment of arthroplasty-related metallosis.

Cobalt-containing alloys are useful for orthopedic applications due to their low volumetric wear rates, corrosion resistance, high mechanical strength, hardness, and fatigue resistance. Unfortunately, these prosthetics release significant levels of cobalt ions, which was only discovered after their widespread implantation into patients requiring hip replacements. These cobalt ions can result in local toxic effects-including peri-implant toxicity, aseptic loosening, and pseudotumor-as well as systemic toxic effects-including neurological, cardiovascular, and endocrine disorders. Failing metal-on-metal (MoM) implants usually necessitate painful, risky, and costly revision surgeries. To treat metallosis arising from failing MoM implants, a synovial fluid-mimicking chelator was designed to remove these metal ions. Hyaluronic acid (HA), the major chemical component of synovial fluid, was functionalized with British anti-Lewisite (BAL) to create a chelator (BAL-HA). BAL-HA effectively binds cobalt and rescues in vitro cell vitality (up to 370% of cells exposed to IC50 levels of cobalt) and enhances the rate of clearance of cobalt in vivo (t1/2 from 48 h to 6 h). A metallosis model was also created to investigate our therapy. Results demonstrate that BAL-HA chelator system is biocompatible and capable of capturing significant amounts of cobalt ions from the hip joint within 30 min, with no risk of kidney failure. This chelation therapy has the potential to mitigate cobalt toxicity from failing MoM implants through noninvasive injections into the joint.

The Promise of Emergent Nanobiotechnologies for In Vivo Applications and Implications for Safety and Security.

Nanotechnology, the multidisciplinary field based on the exploitation of the unique physicochemical properties of nanoparticles (NPs) and nanoscale materials, has opened a new realm of possibilities for biological research and biomedical applications. The development and deployment of mRNA-NP vaccines for COVID-19, for example, may revolutionize vaccines and therapeutics. However, regulatory and ethical frameworks that protect the health and safety of the global community and environment are lagging, particularly for nanotechnology geared toward biological applications (ie, bionanotechnology). In this article, while not comprehensive, we attempt to illustrate the breadth and promise of bionanotechnology developments, and how they may present future safety and security challenges. Specifically, we address current advancements to streamline the development of engineered NPs for in vivo applications and provide discussion on nano-bio interactions, NP in vivo delivery, nanoenhancement of human performance, nanomedicine, and the impacts of NPs on human health and the environment.

Ultra-low binder content 3D printed calcium phosphate graphene scaffolds as resorbable, osteoinductive matrices that support bone formation in vivo.

Bone regenerative engineering could replace autografts; however, no synthetic material fulfills all design criteria. Nanocarbons incorporated into three-dimensional printed (3DP) matrices can improve properties, but incorporation is constrained to low wt%. Further, unmodified nanocarbons have limited osteogenic potential. Functionalization to calcium phosphate graphene (CaPG) imparts osteoinductivity and osteoconductivity, but loading into matrices remained limited. This work presents ultra-high content (90%), 3DP-CaPG matrices. 3DP-CaPG matrices are highly porous (95%), moderately stiff (3 MPa), and mechanically robust. In vitro, they are cytocompatible and induce osteogenic differentiation of human mesenchymal stem cells (hMSCs), indicated by alkaline phosphatase, mineralization, and COL1α1 expression. In vivo, bone regeneration was studied using a transgenic fluorescent-reporter mouse non-union calvarial defect model. 3DP-CaPG stimulates cellular ingrowth, retains donor cells, and induces osteogenic differentiation. Histology shows TRAP staining around struts, suggesting potential osteoclast activity. Apparent resorption of 3DP-CaPG was observed and presented no toxicity. 3DP-CaPG represents an advancement towards a synthetic bone regeneration matrix.

Relevance of Biotin Deficiency in Patients with Inflammatory Bowel Disease and Utility of Serum 3 Hydroxyisovaleryl Carnitine as a Practical Everyday Marker.

BACKGROUND: Biotin, a water-soluble B vitamin, has demonstrable anti-inflammatory properties. A biotin-deficient diet induced a colitis-like phenotype in mice, alleviable by biotin substitution. Mice with dextran sulfate sodium (DSS)-induced colitis showed biotin deficiency and diminished levels of sodium-dependent multivitamin transporter, a protein involved in biotin absorption. Biotin substitution induced remission by reducing activation of NF-κB, a transcription factor involved in intestinal permeability and inflammatory bowel disease (IBD). We investigated for the first time a possible clinical role of biotin status in IBD. METHODS: In a comparative, retrospective, cross-sectional study, serum samples of 138 patients with IBD (67 female; 72 Crohn's disease (CD), 66 ulcerative colitis (UC)) aged 18-65 years and with a mean age (±SD) of 42.5 ± 14.3 years as well as 80 healthy blood donors (40 female; 40.0 ± 10.0 years; range 20-60 years) were analyzed. Inflammation was defined as hsCRP ≥5 mg/L, and to determine biotin status, serum 3-hydroxyisovaleryl carnitine (3HIVc) levels were measured by LC-MS/MS. RESULTS: A total of 138 patients with IBD (67f; 72CD/66 UC; 42.5 ± 14.3 years) were enrolled: 83/138 had inflammation. Mean serum 3HIVc levels were significantly higher in IBD patients but unaffected by inflammation. Biotin deficiency (95th percentile of controls: >30 nmol/L 3HIVc) was significantly more common in IBD patients versus controls. CONCLUSION: High serum 3HIVc levels and biotin deficiency were associated with IBD but not inflammatory activity or disease type. Our findings suggest biotin may play a role as cause or effect in IBD pathogenesis. Routine assessment and supplementation of biotin may ameliorate IBD and support intestinal integrity.

Community dynamics of soil-borne fungal communities along elevation gradients in neotropical and palaeotropical forests.

Because of their steep gradients in abiotic and biotic factors, mountains offer an ideal setting to illuminate the mechanisms that underlie patterns of species distributions and community assembly. We compared the composition of taxonomically and functionally diverse fungal communities in soils along five elevational gradients in mountains of the Neo- and Palaeotropics (northern Argentina, southern Brazil, Panama, Malaysian Borneo and Papua New Guinea). Both the richness and composition of soil fungal communities reflect environmental factors, particularly temperature and soil pH, with some shared patterns among neotropical and palaeotropical regions. Community dynamics are characterized by replacement of species along elevation gradients, implying a relatively narrow elevation range for most fungi, which appears to be driven by contrasting environmental preferences among both functional and taxonomic groups. For functional groups dependent on symbioses with plants (especially ectomycorrhizal fungi), the distribution of host plants drives richness and community composition, resulting in important differences in elevational patterns between neotropical and palaeotropical montane communities. The pronounced compositional and functional turnover along elevation gradients implies that tropical montane forest fungi will be sensitive to climate change, resulting in shifts in composition and functionality over time.

Pearlescent Mica-Doped Alginate as a Stable, Vibrant Medium for Two-Dimensional and Three-Dimensional Art.

Emergent technologies are driving forces in the development of innovative art media that progress the field of modern art. Recently, artists have capitalized on the versatility of a new technology to create, restore, and modify art: additive manufacturing or three-dimensional (3D) printing. Additively manufactured art relies heavily on plastic-based materials, which typically require high heat to induce melting for workability. The necessity for heat limits plastic media to dedicated 3D printers. In contrast, biologically derived polymers such as polysaccharides used to create "bioinks" often do not require heating the material for workability, broadening the types of techniques available for printing. Here, we detail the formulation of a bioink consisting of mica pigments suspended in alginate as a new, vibrant art medium for 2D and 3D compositions. The properties that make alginate an ideal colorant binder are detailed: low cost with wide availability, nontoxicity and biocompatibility, minimal color, and an array of attractive physicochemical properties that offer workability and processing into 2D and 3D structures. Further, the chemical composition, morphology, and dispersibility of an array of mica pigment additives are characterized in detail as they pertain to the quality of an art medium. Alginate-based media with eight mica colors were formulated, where mica addition resulted in vibrantly colored inks with moderate hiding power and coverage of substrates necessary for 2D printing with thin horizontal and vertical lines. The utility of the media is demonstrated via the generation of 2D and 3D vibrant structures.

The Blanket Effect: How Turning the World Upside Down Reveals the Nature of Graphene Oxide Cytocompatibility.

Extensive cytocompatibility testing of 2D nanocarbon materials including graphene oxide (GO) has been performed, but results remain contradictory. Literature has yet to account for settling-although sedimentation is visible to the eye and physics suggests that even individual graphenic flakes will settle. To investigate settling, a series of functional graphenic materials (FGMs) with differing oxidation levels, functionalities, and physical dimensions are synthesized. Though zeta potential indicates colloidal stability, significant gravitational settling of the FGMs is theoretically and experimentally demonstrated. By creating a setup to culture cells in traditional and inverted orientations in the same well, a "blanket effect" is demonstrated in which FGMs settle out of solution and cover cells at the bottom of the well, ultimately reducing viability. Inverted cells protected from the blanket effect are unaffected. Therefore, these results demonstrate that settling is a crucial factor that must be considered for FGM cytocompatibility experiments.

Tunable, bacterio-instructive scaffolds made from functional graphenic materials.

The balance of bacterial populations in the human body is critical for human health. Researchers have aimed to control bacterial populations using antibiotic substrates. However, antibiotic materials that non-selectively kill bacteria can compromise health by eliminating beneficial bacteria, which leaves the body vulnerable to colonization by harmful pathogens. Due to their chemical tunablity and unique surface properties, graphene oxide (GO)-based materials - termed "functional graphenic materials" (FGMs) - have been previously designed to be antibacterial but have the capacity to actively adhere and instruct probiotics to maintain human health. Numerous studies have demonstrated that negatively and positively charged surfaces influence bacterial adhesion through electrostatic interactions with the negatively charged bacterial surface. We found that tuning the surface charge of FGMs provides an avenue to control bacterial attachment without compromising vitality. Using E. coli as a model organism for Gram-negative bacteria, we demonstrate that negatively charged Claisen graphene (CG), a reduced and carboxylated FGM, is bacterio-repellent through electrostatic repulsion with the bacterial surface. Though positively charged poly-l-lysine (PLL) is antibacterial when free in solution by inserting into the bacterial cell wall, here, we found that covalent conjugation of PLL to CG (giving PLLn-G) masks the antimicrobial activity of PLL by restricting polypeptide mobility. This allows the immobilized positive charge of the PLLn-Gs to be leveraged for E. coli adhesion through electrostatic attraction. We identified the magnitude of positive charge of the PLLn-G conjugates, which is modulated by the length of the PLL peptide, as an important parameter to tune the balance between the opposing forces of bacterial adhesion and proliferation. We also tested adhesion of Gram-positive B. subtilis to these FGMs and found that the effect of FGM charge is less pronounced. B. subtilis adheres nondiscriminatory to all FGMs, regardless of charge, but adhesion is scarce and localized. Overall, this work demonstrates that FGMs can be tuned to selectively control bacterial response, paving the way for future development of FGM-based biomaterials as bacterio-instructive scaffolds through careful design of FGM surface chemistry.

Robotic Surgery: The Impact of Simulation and Other Innovative Platforms on Performance and Training.

OBJECTIVE: To review the current status of robotic training and the impact of various training platforms on the performance of robotic surgical trainees. DATA SOURCES: Literature review of Google Scholar and PubMed. The search terms included a combination of the following: "robotic training," "simulation," "robotic curriculum," "obgyn residency robotic training," "virtual reality robotic training," "DaVinci training," "surgical simulation," "gyn surgical training." The sources considered for inclusion included peer-reviewed articles, literature reviews, textbook chapters, and statements from various institutions involved in resident training. METHODS OF STUDY SELECTION: A literature search of Google Scholar and PubMed using terms related to robotic surgery and robotics training, as mentioned in the "Data Sources" section. RESULTS: Multiple novel platforms that use machine learning and real-time video feedback to teach and evaluate robotic surgical skills have been developed over recent years. Various training curricula, virtual reality simulators, and other robotic training tools have been shown to enhance robotic surgical education and improve surgical skills. The integration of didactic learning, simulation, and intraoperative teaching into more comprehensive training curricula shows positive effects on robotic skills proficiency. Few robotic surgery training curricula have been validated through peer-reviewed study, and there is more work to be completed in this area. In addition, there is a lack of information about how the skills obtained through robotics curricula and simulation translate into operating room performance and patient outcomes. CONCLUSION: Data collected to date show promising advances in the training of robotic surgeons. A diverse array of curricula for training robotic surgeons continue to emerge, and existing teaching modalities are evolving to keep up with the rapidly growing demand for proficient robotic surgeons. Futures areas of growth include establishing competency benchmarks for existing training tools, validating existing curricula, and determining how to translate the acquired skills in simulation into performance in the operating room and patient outcomes. Many surgical training platforms are beginning to expand beyond discrete robotic skills training to procedure-specific and team training. There is still a wealth of research to be done to understand how to create an effective training experience for gynecologic surgical trainees and robotics teams.

Acid Mine Drainage Remediation: Aluminum Chelation Using Functional Graphenic Materials.

Acid mine drainage (AMD) is a pervasive source of metal pollution that severely impacts freshwater ecosystems and has a direct impact on human health. Conventional active and passive methods work very well for removing iron in AMD remediation, which is typically the highest metallic impurity. However, conventional passive remediation fails to remove all aluminum, which has severe ecological implications. Removal of aluminum ions using chelation, which traditionally uses small molecules that bind metals tightly for sequestration, holds promise. Yet, chelation strategies are limited because once introduced into surface water, small molecules are difficult to reclaim and often persist in the environment as pollutants. To address this, we have designed six unique scaffolds based on functional graphenic materials (FGMs) to create nonsoluble materials that could be placed at the end of a passive remediation process to remove persistent aluminum. When tested for efficacy, all six FGMs successfully demonstrated a reversible capacity to remove aluminum from acidic water, chelating up to 21 µg of Al/mg of FGM. Furthermore, when they were exposed to E. coli as an approximation for environmental compatibility, viability was unaffected, even at high concentrations, suggesting these FGMs are nontoxic and viable candidates for passive chelation-based remediation.

Polyester functional graphenic materials as a mechanically enhanced scaffold for tissue regeneration.

Traditional metal implants such as titanium, cobalt, and chromium have found wide utility in medicine; however, these come with a risk of toxicity. To overcome metal-related toxicity and enable degradability, polyesters including polycaprolactone (PCL), polylactic acid (PLA), and polyglycolic acid (PGA) show promise for the replacement of various biomedical applications of metals due to their accepted biocompatibility and FDA approval. However, polyesters are less stiff than their metallic counterparts, limiting their application to non-load bearing injury sites, such as fixation hardware for fingers. To improve mechanical properties, graphene oxide (GO)-polyester composites are a promising class of biodegradable scaffolds. Initial reports of these composites are encouraging, but mechanical properties still fall short. Traditional composites rely on non-covalent association between GO and the polyesters, which often leads to failure at the interface and weakens the overall strength of the material. Herein, we present a strategy for attachment of these FDA-approved polyesters onto a derivative of GO using a robust covalent bond. By covalently functionalizing the graphenic backbone with polyesters and without metal catalysts, we create functional graphenic materials (FGMs) to not only simultaneously retain biodegradability and compatibility, but also mechanically strengthen PCL, PLA, and PGA; we observed an average increase in the Young's modulus of over 140% compared to the graphenic backbone. These polyester-functionalized FGMs are a promising platform technology for tissue implants.

Functional Graphenic Materials That Seal Condenser Tube Leaks in Situ.

Undesirable condenser tube leaks frequently occur in power plants, resulting in reduced power output, increased burden on downstream systems, and substantial revenue losses. Current techniques such as wood flour provide temporary in situ remediation but lack adhesive properties to form stable seals. Here, we report the development of in situ sealants for long-term defect repair. The carboxylic acids on graphene oxides and Claisen graphene were used as chemical handles to covalently install a bio-inspired, adhesive catechol, generating a class of functional graphenic material (FGM) sealants. FGM sealants outperformed unfunctionalized scaffolds with enhanced antimicrobial activity to prevent fouling (up to 55% reduction) and superior cohesive properties to promote stable seals. Further, FGM sealants were adhesive, effectively sealing defects in a model experiment, whereas unfunctionalized scaffolds did not display any sealant capacity.

Phosphate graphene as an intrinsically osteoinductive scaffold for stem cell-driven bone regeneration.

Synthetic, resorbable scaffolds for bone regeneration have potential to transform the clinical standard of care. Here, we demonstrate that functional graphenic materials (FGMs) could serve as an osteoinductive scaffold: recruiting native cells to the site of injury and promoting differentiation into bone cells. By invoking a Lewis acid-catalyzed Arbuzov reaction, we are able to functionalize graphene oxide (GO) to produce phosphate graphenes (PGs) with unprecedented control of functional group density, mechanical properties, and counterion identity. In aqueous environments, PGs release inducerons, including Ca2+ and PO43- Calcium phosphate graphene (CaPG) intrinsically induces osteogenesis in vitro and in the presence of bone marrow stromal cells (BMSCs), can induce ectopic bone formation in vivo. Additionally, an FGM can be made by noncovalently loading GO with the growth factor recombinant human bone morphogenetic protein 2 (rhBMP-2), producing a scaffold that induces ectopic bone formation with or without BMSCs. The FGMs reported here are intrinsically inductive scaffolds with significant potential to revolutionize the regeneration of bone.

Utilising the Delphi Process to Develop a Proficiency-based Progression Train-the-trainer Course for Robotic Surgery Training.

CONTEXT: As the role of robot-assisted surgery continues to expand, development of standardised and validated training programmes is becoming increasingly important. OBJECTIVE: To provide guidance on an optimised "train-the-trainer" (TTT) structured educational programme for surgical trainers, in which delegates learn a standardised approach to training candidates in skill acquisition. We aim to describe a TTT course for robotic surgery based on the current published literature and to define the key elements within a TTT course by seeking consensus from an expert committee formed of key opinion leaders in training. EVIDENCE ACQUISITION: The project was carried out in phases: a systematic review of the current evidence was conducted, a face-to-face meeting was held in Philadelphia, and then an initial survey was created based on the current literature and expert opinion and sent to the committee. Thirty-two experts in training, including clinicians, academics, and industry, contributed to the Delphi process. The Delphi process underwent three rounds of survey in total. Additions to the second- and third-round surveys were formulated based on the answers and comments from the previous rounds. Consensus opinion was defined as ≥80% agreement. EVIDENCE SYNTHESIS: There was 100% consensus that there was a need for a standardized TTT course in robotic surgery. A consensus was reached in multiple areas, including the following: (1) definitions and terminologies, (2) qualifications to attend, (3) course objectives, (4) precourse considerations, (5) requirement of e-learning, (6) theory and course content, and (7) measurement of outcomes and performance level verification. The resulting formulated curriculum showed good internal consistency among experts, with a Cronbach alpha of 0.90. CONCLUSIONS: Using the Delphi methodology, we achieved an international consensus among experts to develop and reach content validation for a standardised TTT curriculum for robotic surgery training. This defined content lays the foundation for developing a proficiency-based progression model for trainers in robotic surgery. This TTT curriculum will require further validation. PATIENT SUMMARY: As the role of robot-assisted surgery continues to expand, development of standardised and validated training programmes is becoming increasingly important. There is currently a lack of high-level evidence on how best to train trainers in robot-assisted surgery. We report a consensus view on a standardised "train-the trainer" curriculum focused on robotic surgery. It was formulated by training experts from the USA and Europe, combining current evidence for training with experts' knowledge of surgical training.

Injectable amine functionalized graphene and chondroitin sulfate hydrogel with potential for cartilage regeneration.

Damaged cartilage does not readily heal and often requires surgical intervention that only modestly improves outcomes. A synthetic material that could be injected and covalently crosslinked in situ to form a bioactive, mechanically robust scaffold that promotes stem cell chondrogenic differentiation holds promise for next-generation treatment of cartilage lesions. Here, Johnson-Claisen rearrangement chemistry was performed on graphene oxide (GO) to enable functionalization with a primary amine covalently bound to the graphenic backbone through a chemically stable linker. The primary amines are used to form covalent crosslinks with chondroitin sulfate, an important component of cartilage that promotes regeneration, to form a hydrogel (EDAG-CS). The EDAG-CS system gels in situ within 10 min, and the graphenic component imparts improved mechanical properties, including stiffness (320% increase) and toughness (70% increase). EDAG-CS hydrogels are highly porous, resistant to degradation, and enable the growth of human mesenchymal stem cells and their deposition of collagen matrix. This system has potential to improve clinical outcomes of patients with cartilage damage.

Defoliating Insect Mass Outbreak Affects Soil N Fluxes and Tree N Nutrition in Scots Pine Forests.

Biotic stress by mass outbreaks of defoliating pest insects does not only affect tree performance by reducing its photosynthetic capacity, but also changes N cycling in the soil of forest ecosystems. However, how insect induced defoliation affects soil N fluxes and, in turn, tree N nutrition is not well-studied. In the present study, we quantified N input and output fluxes via dry matter input, throughfall, and soil leachates. Furthermore, we investigated the effects of mass insect herbivory on tree N acquisition (i.e., organic and inorganic 15N net uptake capacity of fine roots) as well as N pools in fine roots and needles in a Scots pine (Pinus sylvestris L.) forest over an entire vegetation period. Plots were either infested by the nun moth (Lymantria monacha L.) or served as controls. Our results show an increased N input by insect feces, litter, and throughfall at the infested plots compared to controls, as well as increased leaching of nitrate. However, the additional N input into the soil did not increase, but reduce inorganic and organic net N uptake capacity of Scots pine roots. N pools in the fine roots and needles of infested trees showed an accumulation of total N, amino acid-N, protein-N, and structural N in the roots and the remaining needles as a compensatory response triggered by defoliation. Thus, although soil N availability was increased via surplus N input, trees did not respond with an increased N acquisition, but rather invested resources into defense by accumulation of amino acid-N and protein-N as a survival strategy.

Graphene oxide as a scaffold for bone regeneration.

Graphene oxide (GO), the oxidized form of graphene, holds great potential as a component of biomedical devices, deriving utility from its ability to support a broad range of chemical functionalities and its exceptional mechanical, electronic, and thermal properties. GO composites can be tuned chemically to be biomimetic, and mechanically to be stiff yet strong. These unique properties make GO-based materials promising candidates as a scaffold for bone regeneration. However, questions still exist as to the compatibility and long-term toxicity of nanocarbon materials. Unlike other nanocarbons, GO is meta-stable, water dispersible, and autodegrades in water on the timescale of months to humic acid-like materials, the degradation products of all organic matter. Thus, GO offers better prospects for biological compatibility over other nanocarbons. Recently, many publications have demonstrated enhanced osteogenic performance of GO-containing composites. Ongoing work toward surface modification or coating strategies could be useful to minimize the inflammatory response and improve compatibility of GO as a component of medical devices. Furthermore, biomimetic modifications could offer mechanical and chemical environments that encourage osteogenesis. So long as care is given to assure their safety, GO-based materials may be poised to become the next generation scaffold for bone regeneration. WIREs Nanomed Nanobiotechnol 2017, 9:e1437. doi: 10.1002/wnan.1437 For further resources related to this article, please visit the WIREs website.