Cell Type-Specific Oxidative Stress Genomic Signatures in the Globus Pallidus of Dopamine-Depleted Mice.

Neuron subtype dysfunction is a key contributor to neurologic disease circuits, but identifying associated gene regulatory pathways is complicated by the molecular complexity of the brain. For example, parvalbumin-expressing (PV+) neurons in the external globus pallidus (GPe) are critically involved in the motor deficits of dopamine-depleted mouse models of Parkinson's disease, where cell type-specific optogenetic stimulation of PV+ neurons over other neuron populations rescues locomotion. Despite the distinct roles these cell types play in the neural circuit, the molecular correlates remain unknown because of the difficulty of isolating rare neuron subtypes. To address this issue, we developed a new viral affinity purification strategy, Cre-Specific Nuclear Anchored Independent Labeling, to isolate Cre recombinase-expressing (Cre+) nuclei from the adult mouse brain. Applying this technology, we performed targeted assessments of the cell type-specific transcriptomic and epigenetic effects of dopamine depletion on PV+ and PV- cells within three brain regions of male and female mice: GPe, striatum, and cortex. We found GPe PV+ neuron-specific gene expression changes that suggested increased hypoxia-inducible factor 2α signaling. Consistent with transcriptomic data, regions of open chromatin affected by dopamine depletion within GPe PV+ neurons were enriched for hypoxia-inducible factor family binding motifs. The gene expression and epigenomic experiments performed on PV+ neurons isolated by Cre-Specific Nuclear Anchored Independent Labeling identified a transcriptional regulatory network mediated by the neuroprotective factor Hif2a as underlying neural circuit differences in response to dopamine depletion.SIGNIFICANCE STATEMENT Cre-Specific Nuclear Anchored Independent Labeling is an enhanced, virus-based approach to isolate nuclei of a specific cell type for transcriptome and epigenome interrogation that decreases dependency on transgenic animals. Applying this technology to GPe parvalbumin-expressing neurons in a mouse model of Parkinson's disease, we discovered evidence for an upregulation of the oxygen homeostasis maintaining pathway involving Hypoxia-inducible factor 2α. These results provide new insight into how neuron subtypes outside the substantia nigra pars compacta may be compensating at a molecular level for differences in the motor production neural circuit during the progression of Parkinson's disease. Furthermore, they emphasize the utility of cell type-specific technologies, such as Cre-Specific Nuclear Anchored Independent Labeling, for isolated assessment of specific neuron subtypes in complex systems.

The impact of the centrifuge characteristics and centrifugation protocols on the cells, growth factors, and fibrin architecture of a leukocyte- and platelet-rich fibrin (L-PRF) clot and membrane.

L-PRF (leukocyte- and platelet-rich fibrin) is one of the four families of platelet concentrates for surgical use and is widely used in oral and maxillofacial regenerative therapies. The first objective of this article was to evaluate the mechanical vibrations appearing during centrifugation in four models of commercially available table-top centrifuges used to produce L-PRF and the impact of the centrifuge characteristics on the cell and fibrin architecture of a L-PRF clot and membrane. The second objective of this article was to evaluate how changing some parameters of the L-PRF protocol may influence its biological signature, independently from the characteristics of the centrifuge. In the first part, four different commercially available centrifuges were used to produce L-PRF, following the original L-PRF production method (glass-coated plastic tubes, 400 g force, 12 minutes). The tested systems were the original L-PRF centrifuge (Intra-Spin, Intra-Lock, the only CE and FDA cleared system for the preparation of L-PRF) and three other laboratory centrifuges (not CE/FDA cleared for L-PRF): A-PRF 12 (Advanced PRF, Process), LW-UPD8 (LW Scientific) and Salvin 1310 (Salvin Dental). Each centrifuge was opened for inspection, two accelerometers were installed (one radial, one vertical), and data were collected with a spectrum analyzer in two configurations (full-load or half load). All clots and membranes were collected into a sterile surgical box (Xpression kit, Intra-Lock). The exact macroscopic (weights, sizes) and microscopic (photonic and scanning electron microscopy SEM) characteristics of the L-PRF produced with these four different machines were evaluated. In the second part, venous blood was taken in two groups, respectively, Intra-Spin 9 ml glass-coated plastic tubes (Intra-Lock) and A-PRF 10 ml glass tubes (Process). Tubes were immediately centrifuged at 2700 rpm (around 400 g) during 12 minutes to produce L-PRF or at 1500 rpm during 14 minutes to produce A-PRF. All centrifugations were done using the original L-PRF centrifuge (Intra-Spin), as recommended by the two manufacturers. Half of the membranes were placed individually in culture media and transferred in a new tube at seven experimental times (up to 7 days). The releases of transforming growth factor ß-1 (TGFß-1), platelet derived growth factor AB (PDGF-AB), vascular endothelial growth factor (VEGF) and bone morphogenetic protein 2 (BMP-2) were quantified using ELISA kits at these seven experimental times. The remaining membranes were used to evaluate the initial quantity of growth factors of the L-PRF and A-PRF membranes, through forcible extraction. Very significant differences in the level of vibrations at each rotational speed were observed between the four tested centrifuges. The original L-PRF centrifuge (Intra-Spin) was by far the most stable machine in all configurations and always remained under the threshold of resonance, unlike the three other tested machines. At the classical speed of production of L-PRF, the level of undesirable vibrations on the original centrifuge was between 4.5 and 6 times lower than with other centrifuges. Intra-Spin showed the lowest temperature of the tubes. A-PRF and Salvin were both associated with a significant increase in temperature in the tube. Intra-Spin produced the heaviest clot and quantity of exudate among the four techniques. A-PRF and LW produced much lighter, shorter and narrower clots and membranes than the two other centrifuges. Light microscopy analysis showed relatively similar features for all L-PRF types (concentration of cell bodies in the first half). However, SEM illustrated considerable differences between samples. The original Intra-Spin L-PRF showed a strongly polymerized thick fibrin matrix and all cells appeared alive with a normal shape, including the textured surface aspect of activated lymphocytes. The A-PRF, Salvin and LW PRF-like membranes presented a lightly polymerized slim fibrin gel and most of the visible cell bodies appeared destroyed (squashed or shrunk). In the second part of this study, the slow release of the three tested growth factors from original L-PRF membranes was significantly stronger (more than twice stronger, p<0.001) at all experimental times than the release from A-PRF membranes. No trace of BMP2 could be detected in the A-PRF. A slow release of BMP2 was detected during at least 7 days in the original L-PRF. Moreover, the original L-PRF clots and membranes (produced with 9 mL blood) were always significantly larger than the A-PRF (produced with 10 mL blood). The A-PRF membranes dissolved in vitro after less than 3 days, while the L-PRF membrane remained in good shape during at least 7 days. Each centrifuge has its clear own profile of vibrations depending on the rotational speed, and the centrifuge characteristics are directly impacting the architecture and cell content of a L-PRF clot. This result may reveal a considerable flaw in all the PRP/PRF literature, as this parameter was never considered. The original L-PRF clot (Intra-Spin) presented very specific characteristics, which appeared distorted when using centrifuges with a higher vibration level. A-PRF, LW and Salvin centrifuges produced PRF-like materials with a damaged and almost destroyed cell population through the standard protocol, and it is therefore impossible to classify these products in the L-PRF family. Moreover, when using the same centrifuge, the original L-PRF protocol allowed producing larger clots/membranes and a more intense release of growth factors (biological signature at least twice stronger) than the modified A-PRF protocol. Both protocols are therefore significantly different, and the clinical and experimental results from the original L-PRF shall not be extrapolated to the A-PRF. Finally, the comparison between the total released amounts and the initial content of the membrane (after forcible extraction) highlighted that the leukocytes living in the fibrin matrix are involved in the production of significant amounts of growth factors. The centrifuge characteristics and centrifugation protocols impact significantly and dramatically the cells, growth factors and fibrin architecture of L-PRF.

Transition-Metal-Free Synthesis of 2-Substituted Methyl Benzo[b]furan-3-carboxylates.

A concise and highly efficient synthetic pathway was developed for 2-substituted methyl benzo[b]furan-3-carboxylates. This method provides convenient and cost-effective access for 2-substituted methyl benzo[b]furan-3-carboxylates without the use of a transition metal catalyst for synthesis. Furthermore, in most cases, this method gives excellent yields and conventional flash column chromatography is not needed for purification.

Compensatory Interactions between Corneal and Internal Astigmatism despite Lifestyle Changes.

This study explores whether children's refractive errors and visual behaviors reverted to pre-COVID-19 levels a year after normal schooling resumed in Hong Kong as well as the impact of corneal and internal astigmatism on refractive astigmatism development. Vision survey data and questionnaire results collected in 2022 (n = 119) and 2020 (n = 173) were compared. Cross-sectional data showed similar proportions of astigmatism (cylindrical power ≥ 0.75 D) in the 2020 (49.1%) and 2022 cohorts (55.5%). Despite a 0.28 D increase in corneal astigmatism, a compensatory 0.24 D increase in internal astigmatism of opposite direction kept refractive astigmatism relatively stable. The questionnaire data showed that children spent an additional 0.5 h/day outdoors on weekends post-resumption of normal schooling but engaged in more near-work activities, especially non-screen near-work, by approximately 1 h/day on both weekdays and weekends. These findings were supported by longitudinal data from 72 children who participated in both surveys. This study highlights the significant role of corneal and internal astigmatism in refractive astigmatism changes. Despite the return to in-person classes, children's total near-work time increased and astigmatism remained high. These findings underscore the need for comprehensive strategies to reduce the high environmental risks for refractive error development in children.

Distinct prefrontal projection activity and transcriptional state conversely orchestrate social competition and hierarchy.

Social animals compete for limited resources, resulting in a social hierarchy. Although different neuronal subpopulations in the medial prefrontal cortex (mPFC), which has been mechanistically implicated in social dominance behavior, encode distinct social competition behaviors, their identities and associated molecular underpinnings have not yet been identified. In this study, we found that mPFC neurons projecting to the nucleus accumbens (mPFC-NAc) encode social winning behavior, whereas mPFC neurons projecting to the ventral tegmental area (mPFC-VTA) encode social losing behavior. High-throughput single-cell transcriptomic analysis and projection-specific genetic manipulation revealed that the expression level of POU domain, class 3, transcription factor 1 (Pou3f1) in mPFC-VTA neurons controls social hierarchy. Optogenetic activation of mPFC-VTA neurons increases Pou3f1 expression and lowers social rank. Together, these data demonstrate that discrete activity and gene expression in separate mPFC projections oppositely orchestrate social competition and hierarchy.

Sn-Doped Zinc Oxide as an Electron Transporting Layer for Enhanced Performance in PbS Quantum Dot Solar Cells.

Colloidal PbS quantum dot solar cells (QDSCs) have been primarily demonstrated in n-i-p structures by incorporating a solution-processed ZnO electron transporting layer (ETL). Nevertheless, the inherent energy barrier for the electron extraction at the ZnO/PbS junction along with the defective nature significantly diminishes the performance of the PbS QDSCs. In this study, by employing Sn-doped ZnO (ZTO) ETL, we have tuned the conduction band offset at the junction from spike-type to cliff-type so that the electron extraction barrier can be eliminated and the overall photovoltaic parameters can be enhanced (open-circuit voltage of 0.7 V, fill factor over 70%, and efficiency of 11.3%) as compared with the counterpart with the undoped ZnO ETL. The X-ray photoelectron spectroscopy (XPS) analysis revealed a mitigation of oxygen vacancies in the ZTO ETL of our PbS QDSCs. Our work signifies the importance of Sn doping into the conventional ZnO ETL for the superior electron extraction in PbS QDSCs.

Korean Medicine Subcision Therapies in Scar Treatment: A Retrospective, Multicenter Study at Network Clinics.

Purpose: This study is a retrospective, multicenter research designed to report the efficacy of Korean medicine subcision therapies in scar treatment. Patients and Methods: Charts and photographs of 29 patients who received subcision treatment between May 2016 and June 2020 in four scar treatment network clinics were analyzed. The Qualitative Global Acne Scarring Grade System (QGASC) and the Stony Brook Scar Evaluation Scale (SBSES) were used to objectively measure scar scores. Results: Except for 4 patients whose GASGS and SBSES scores remained unchanged, most patients' scars showed improvement from Visit 2 to about Visit 8. Furthermore, the degree of change for both scales was found to be statistically significant. Conclusion: Subcision therapy using acupuncture has been found to be an effective treatment for scar, with statistically significant improvements in patients' SBSES and QGASC scores.

Spatial, transcriptomic, and epigenomic analyses link dorsal horn neurons to chronic pain genetic predisposition.

Key mechanisms underlying chronic pain occur within the dorsal horn. Genome-wide association studies (GWASs) have identified genetic variants predisposed to chronic pain. However, most of these variants lie within regulatory non-coding regions that have not been linked to spinal cord biology. Here, we take a multi-species approach to determine whether chronic pain variants impact the regulatory genomics of dorsal horn neurons. First, we generate a large rhesus macaque single-nucleus RNA sequencing (snRNA-seq) atlas and integrate it with available human and mouse datasets to produce a single unified, species-conserved atlas of neuron subtypes. Cellular-resolution spatial transcriptomics in mouse shows the precise laminar location of these neuron subtypes, consistent with our analysis of neuron-subtype-selective markers in macaque. Using this cross-species framework, we generate a mouse single-nucleus open chromatin atlas of regulatory elements that shows strong and selective relationships between the neuron-subtype-specific chromatin regions and variants from major chronic pain GWASs.

Experimental evidence for interfacial biochemical bonding in osseointegrated titanium implants.

OBJECTIVES: (i) To identify and quantify an interfacial biochemical bond and the bonding strength of osseointegrated implants with bioactive titanium oxide chemistry, ATiO(x)B (A, metal cations; TiO(x) , titanium oxides/hydroxides; B, non-metal anions) and (ii) to provide quantitative evidence for the biochemical bond theory of osseointegration proposed by Sul et al. for description and explanation of why and how the implants with ATiO(x) B surface oxide chemistry may exhibit a significantly stronger bone response, in spite of the fact that the roughness values approached zero, or were equivalent to or significantly lower than those of the control implants. MATERIALS AND METHODS: We applied a newly developed biochemical bond measurement (BBM) method to model implant surfaces that were "perfectly" smooth nanotopography near-zero roughness as the constant parameter, and used the bioactive surface chemistry of titanium oxide, ATiOx B chemistry as a variable parameter in rabbit tibiae for 10 weeks. In this manner, we determined an interfacial biochemical bond and quantified its bonding strength. RESULTS: The increase in biochemical bond strengths of the test implant relative to the control implant was determined to be 0.018 (±0.008) MPa (0.031 vs 0.021 MPa, n = 10) for tensile strength and 8.9 (±6.1) Ncm (33.0 vs 24.1 Ncm, n = 10) for removal torque. Tensile and removal torque show strong correlation in the Pearson test (r = 0.901, P ≤ 0.001). In addition, histomorphometric measurements including bone-to-metal-contact (BMC, P = 0.007), bone area and newly formed bone showed significant increases in the mean values for ATiO(x) B chemistry (P = 0.007, n = 10). Biochemical bond theory states that the surface oxide chemistry, ATiO(x) B must have more electrical and chemical molecular polarity that fractionally charges the surfaces denoted as δ(+) and δ(-) and leads to electrostatic and electrodynamic interactions with the bone healing cascade, eventually leading to the formation of biochemical bonding at the bone/implant interface. CONCLUSIONS: The present study has provided quantitative evidence for biochemical bond theory of osseointegration of implants with bioactive surface oxide chemistry, ATiO(x) B. The theory of biochemical bonds may provide a scientific rationale pertinent to recent emerging trends and technologies for surface chemistry modifications of implants.

The effect of calcium ion concentration on the bone response to oxidized titanium implants.

AIM: To investigate the effect of calcium concentration on the bone tissue response to Ca-incorporated titanium implants. MATERIALS AND METHODS: Two titanium surfaces containing 4.2% and 6.6% calcium were prepared using the micro-arc oxidation process. The implants were inserted in the tibia of nine New Zealand White rabbits. After 6 weeks of healing, the bone response to the implants was quantitatively compared by biomechanical and histomorphometrical measurements. RESULTS: Ca 4.2% and Ca 6.6% containing implants revealed no distinctive differences in their qualitative surface chemistry; chemical bonding state of Ca in titanium oxide was mainly calcium titanates. No significant differences were observed between two implants in peak removal torque and shear strength comparisons (P>0.05). Histomorphometrical analyses presented no significant differences in bone-metal contact, bone area and newly formed bone measurements between two implants (P>0.05). CONCLUSIONS: From biomechanical and histomorphometrical measurements, the two calcium concentrations in this study did not differ significantly with respect to their influence on the bone tissue response. This similar bone response in rabbit tibiae may be explained by the similarity of the qualitative Ca chemistry in titanium surfaces.

Prevention and management of adverse events following COVID-19 vaccination using traditional Korean medicine: An online survey of public health doctors.

BACKGROUND: Since February 2021, vaccination against coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 has started in Korea. AIM: To perform a questionnaire survey about the prevention and management of adverse events of COVID-19 vaccination among public health doctors of Korean Medicine (PHKMDs). METHODS: An online questionnaire was developed, comprising categories about adverse events of vaccination (AEVs) and perception of using Korean medicine (KM) in managing vaccine adverse events (AEs) among PHKMDs. PHKMDs' experience of AEVs, usage of Korean medicine for AEVs, and perception and attitude in using KM for AEVs were surveyed. The survey web-link was emailed to the association of PHKMDs. Online links were sent through Survey Monkey to all PHKMDs in Korea. RESULTS: A total of 143 participants were recruited for this study; 65% of participants were vaccinated at the same of the survey (n = 93). Although most participants did not take any medication for prevention of the adverse events, 62% (n = 58) of participants had taken herbal medicine to treat the adverse events (n = 52). Approximately 35% of participants (n = 33) said that they would recommend taking herbal medicine to prevent any AEVs. From various KM interventions, the participants strongly recommended taking an herbal medicine (n = 69, 74.19%) to treat AEs, and the second-highest was acupuncture treatment (n = 19, 20.43%). CONCLUSION: Overall, this research demonstrated a high prevalence of KM usage by the PHKMDs. Hence, this study's results may serve as fundamental evidence for health professionals to consider using KM treatments when treating or preventing AEVs in the near future.

Observational study of home-based integrative Korean medicine program to satisfy unmet healthcare needs of persons with disability.

OBJECTIVE: To overcome the limitations of the previous studies by implementing traditional east Asian medicine home-based healthcare program for People with disabilities (PWDs)1 based on a standard protocol developed by the government. METHODS: Twenty participants with limb or brain impairment with severe grade were selected from a Public Health Center in Korea. Objective outcome variables were used, a patient perspective was provided, and a standardized treatment regimen was adopted to overcome the limitations of previous studies. RESULTS: Participants reported significant improvements in Overall pain and Quality of life. CONCLUSIONS: IKMHP showed possibility of integrative management for PWDs in terms of pain, quality of life, safety and overall satisfaction.

Utilization of Acupuncture and Herbal Ointment Instead of Skin Graft Surgery for the Treatment of Burn Injuries: A Case Series and Literature Review.

Skin graft surgery is a standard treatment that increases the survival rate of patients with burn injuries; however, it leaves many sequelae. Conventional external preparations for the treatment of burns also have various side effects. In this retrospective case study, we assessed the cases of four patients with topical third-degree burns who did not wish to undergo the skin graft surgeries recommended by medical doctors and were thus treated using traditional medicine alone. A Korean medicine doctor administered integrative traditional medicine treatment to the patients using acupuncture and herbal ointments. Analysis of the patients' treatment photographs, quantitative evaluation indices, and vivid narratives suggested that their skin recovered well without adverse effects. Traditional Korean medicine treatment, including acupuncture and herbal ointment treatment, can be a new alternative therapeutic strategy for the treatment of patients with topical burns who do not want to undergo skin graft surgery or who have higher risks for poor surgical outcomes.

Comprehensive traditional East Asian medicine treatment strategy for obesity considering the therapeutic effects and adverse events: A protocol for systematic review and network meta-analysis.

BACKGROUND: Obesity has become a serious global health problem due to its increasing prevalence. Because of several limitations or adverse events associated with conventional western medicine therapies, there has been an increase in demand for alternative therapies such as traditional East Asian medicine (TEAM). This study aims to provide comprehensive evidence-based information assessing the clinical efficacy and safety of TEAM treatment for obesity as the basis for reliable clinical strategies for patients with obesity. METHODS: Electronic searches of the PubMed, Cochrane Library, EMBASE, China National Knowledge Infrastructure, OASIS, and Korea Citation Index will be performed. Methodological quality will be assessed using the "risk of bias" tool. The primary outcome for efficacy will be weight loss. The secondary outcomes will be response rate, body mass index, waist circumference, and blood pressure. We will also evaluate the rates of adverse events and mortality for safety assessment. First, we will conduct a conventional pairwise meta-analysis. Next, we will conduct network meta-analysis using the frequentist approach. We shall verify the assumption of network meta-analysis and provide network geometry, P-score, net league table, and intervention-based forest plot. A subgroup analysis will be conducted to ascertain the factors that affect treatment, such as dosage, treatment duration, and severity of obesity. RESULTS: The results of this study will provide high-quality systematic reviews that can assist decision making in obesity management. Our network meta-analysis results can provide direct and indirect comparison evidence on comparative efficacy and safety. CONCLUSION: This study will provide fundamental data for prospective research on the application of TEAM in patients with obesity. PROTOCOL REGISTRY NUMBER OF ONLINE REGISTRY: This study protocol was registered in open Science framework (OSF) (Registration DOI: 10.17605/OSF.IO/ETWDS). URL OF THE ONLINE REGISTRY: https://osf.io/etwds.

Fascin Regulates the Hippo Pathway and Is Important for Melanoma Development.

BACKGROUND/AIM: Fascin, an actin-bundling protein, plays an essential role in cancer metastasis. The Hippo pathway is critical for carcinogenesis and cancer stem cell self-renewal. Mammalian STE20-like kinase (MST) is a core component of the Hippo pathway. However, whether fascin and MST2 affect melanoma remain largely unknown. This study aimed to investigate the role of fascin and MST2 in melanoma development. MATERIALS AND METHODS: Surgically excised skin melanomas and the adjacent non-tumorous skin tissue from 30 cases were analyzed using immunohistochemistry for fascin and MST2. The melanoma cell line WM793 was employed for fascin and MST2 knock-down followed by western blotting, and melanoma xenografting in BALB/c mice. RESULTS: Immunohistochemistry revealed increased expression of fascin and decreased expression of MST2 in melanoma. The reverse correlation of fascin and MST2 was statistically significant. Fascin siRNA upregulated MST2 expression; however, MST2 siRNA did not significantly affect fascin expression in the WM793. WM793 xenografting followed by fascin knock-down inhibited tumor growth significantly in the animal study. CONCLUSION: Fascin is a regulator of the Hippo pathway and plays an important role in melanoma development. Therefore, fascin could be a potential therapeutic target for melanoma.

Extracellular Acidity-mediated Expression of cPLA2γ Confers Resistance in Gastric Cancer Cells.

BACKGROUND/AIM: Extracellular acidity, a characteristic of solid tumors, has been proposed to be a critical factor for aggravating tumor malignancy and conferring resistance to therapeutics. Recently, acidity has been implicated in inflammatory responses, which are mediated through active lipid metabolites in various human tissues. In the present study, we investigated whether acidity can affect lipid-mediated signaling, and found that phospholipase A2 (PLA2) activity increased at acidic pH in SNU601 and AGS gastric carcinoma cell lines. MATERIALS AND METHODS: To identify the PLA2 isoform that is responsible for the acidity-induced activity, we assessed mRNA levels of cPLA2 isotypes through real-time qPCR, and protein levels through immunoblot assay in cells cultured in acidic medium. RESULTS: It was found that acidic pH conditions markedly elevated the PLA2γ expression. A gene interference study using specific siRNA of cPLA2γ suggested that expression of cPLA2γ in acidic culture conditions may be associated with protection of cancer cells in acidic environment, as shown by cell viability and clonogenic assays. In addition, expression of cPLA2γ appeared to confer cell resistance to anticancer drugs under acidic pH conditions. CONCLUSION: Acidity-induced cPLA2γ expression may exert protective effects by imparting resistance to the gastric cancer cells under acidic environment.

3D Printer-Based Encapsulated Origami Electronics for Extreme System Stretchability and High Areal Coverage.

Stretchability and areal coverage of active devices are critical design considerations of stretchable or wearable photovoltaics and photodetections where high areal coverages are required. However, simultaneously maximizing both properties in conventional island-bridge structures through traditional two-dimensional manufacturing processes is difficult due to their inherent trade-offs. Here, a 3D printer-based strategy to achieve extreme system stretchability and high areal coverage through combining fused deposition modeling (FDM) and flexible conductive nanocomposites is reported. Distinguished from typical approaches of using conductive filaments for FDM which have a flexibility dilemma and conductivity trade-offs, the proposed axiomatic approach to embed a two-dimensional silver nanowire percolation network into the surfaces of flexible 3D printed structures offers sufficient conductivity and deformability as well as additional benefits of electrical junction enhancement and encapsulation of silver nanowires. Kirigami/origami-pattern-guided three-dimensional arrangements of encapsulated interconnections provide efficient control over stretchability and areal coverage. The suggested process enables a perovskite solar module with an initial areal coverage of ∼97% to be electrically and mechanically reversible with 400% system stretchability and 25 000% interconnect stretchability under the 1000 cycle test, by folding down or hiding the origami-applied interconnects under the islands. This 3D printing strategy of potentially low cost, large size capabilities, and high speed is promising for highly flexible future energy conversion applications.

Heterogeneously Assembled Metamaterials and Metadevices via 3D Modular Transfer Printing.

Metamaterials have made the exotic control of the flow of electromagnetic waves possible, which is difficult to achieve with natural materials. In recent years, the emergence of functional metadevices has shown immense potential for the practical realization of highly efficient photonic devices. However, complex and heterogeneous architectures that enable diverse functionalities of metamaterials and metadevices have been challenging to realize because of the limited manufacturing capabilities of conventional fabrication methods. Here, we show that three-dimensional (3D) modular transfer printing can be used to construct diverse metamaterials in complex 3D architectures on universal substrates, which is attractive for achieving on-demand photonic properties. Few repetitive processing steps and rapid constructions are additional advantages of 3D modular transfer printing. Thus, this method provides a fascinating route to generate flexible and stretchable 2D/3D metamaterials and metadevices with heterogeneous material components, complex device architectures, and diverse functionalities.

Subwavelength imaging in the visible range using a metal coated carbon nanotube forest.

We demonstrate subwavelength imaging in the visible range by using a metal coated carbon nanotube forest. Under 532 nm illumination, a 160 nm separated double slit is resolved. This corresponds to the resolution of 0.3 wavelength. By controlling the growing conditions and with the help of the microtoming technique, we made a dense carbon nanotube forest layer of 400 nm thickness. The metal coated carbon nanotube forest, acting as a wire medium nanolens, delivers imaging information including details in the evanescent fields near the objects.

Improved neural differentiation of human mesenchymal stem cells interfaced with carbon nanotube scaffolds.

AIM: The authors aimed to investigate the effect of carbon nanotube (CNT)-based extracellular environments on the neural differentiation of human mesenchymal stem cells (hMSCs) when combined with chemical inducers. MATERIALS & METHODS: CNT-based nanoscaffolds (linear CNT network patterns and CNT bulk network films) were prepared on solid substrates for hMSC culturing. After the hMSCs were differentiated in neural differentiation media for 2 weeks, the authors examined the neural differentiation of the hMSCs using immunocytochemistry and real-time PCR. RESULTS: The authors found that the linear CNT network patterns could effectively control the cell elongation and nuclear shape of hMSCs during the neural differentiation process, further enhancing neural gene expression compared with the bulk CNT-based films. Moreover, the CNT network films could significantly upregulate the gene expression of voltage-gated ion channels, which should be a key component for the neural activity of differentiated hMSCs. CONCLUSION: These findings suggest that CNT-based nanoscaffolds can be used as an excellent extracellular nano-/micro-environment for applications requiring effective neural differentiation of stem cells, such as regenerative medicine and tissue engineering.