Spatial Tuning of Light-Matter Interaction via Strain-Gradient-Induced Polarization in Freestanding Wrinkled 2D Materials.

To date, controlled deformation of two-dimensional (2D) materials has been extensively demonstrated with substrate-supported structures. However, interfacial effects arising from these supporting materials may suppress or alter the unique behavior of the deformed 2D materials. To address interfacial effects, we report, for the first time, the formation of a micrometer-scale freestanding wrinkled structure of 2D material without any encapsulation layers where we observed the enhanced light-matter interactions with a spatial modulation. Freestanding wrinkled monolayer WSe2 exhibited about a 330% enhancement relative to supported wrinkled WSe2 quantified through photoinduced force microscopy. Spatial modulation and enhancement of light interaction in the freestanding wrinkled structures are attributed to the enhanced strain-gradient effect (i.e., out-of-plane polarization) enabled by removing the constraining support and proximate dielectrics. Our findings offer an additional degree of freedom to modulate the out-of-plane polarization and enhance the out-of-plane light-matter interaction in 2D materials.

MoS2 Passivated Multilayer Graphene Membranes for Li-Ion Extraction From Seawater.

Abundant Li resources in the ocean are promising alternatives to refining ore, whose supplies are limited by the total amount and geopolitical imbalance of reserves in Earth's crust. Despite advances in Li+ extraction using porous membranes, they require screening other cations on a large scale due to the lack in precise control of pore size and inborn defects. Herein, MoS2 nanoflakes on a multilayer graphene membrane (MFs-on-MGM) that possess ion channels comprising i) van der Waals interlayer gaps for optimal Li+ extraction and ii) negatively charged vertical inlets for cation attraction, are reported. Ion transport measurements across the membrane reveal ≈6- and 13-fold higher selectivity for Li+ compared to Na+ and Mg2+ , respectively. Furthermore, continuous, stable Li+ extraction from seawater is demonstrated by integrating the membrane into a H2 and Cl2 evolution system, enabling more than 104 -fold decrease in the Na+ concentration and near-complete elimination of other cations.

Role of Thin Film Adhesion on Capillary Peeling.

The capillary force can peel off a substrate-attached film if the adhesion energy (Gw) is low. Capillary peeling has been used as a convenient, rapid, and nondestructive method for fabricating free-standing thin films. However, the critical value of Gw, which leads to the transition between peeling and sticking, remains largely unknown. As a result, capillary peeling remains empirical and applicable to a limited set of materials. Here, we investigate the critical value of Gw and experimentally show the critical adhesion (Gw,c) to scale with the water-film interfacial energy (≈0.7γfw), which corresponds well with our theoretical prediction of Gw,c = γfw. Based on the critical adhesion, we propose quantitative thermodynamic guidelines for designing thin film interfaces that enable successful capillary peeling. The outcomes of this work present a powerful technique for thin film transfer and advanced nanofabrication in flexible photovoltaics, battery materials, biosensing, translational medicine, and stretchable bioelectronics.

Polarization Control of Deterministic Single-Photon Emitters in Monolayer WSe2.

Single-photon emitters, the basic building blocks of quantum communication and information, have been developed using atomically thin transition metal dichalcogenides (TMDCs). Although the bandgap of TMDCs was spatially engineered in artificially created defects for single-photon emitters, it remains a challenge to precisely align the emitter's dipole moment to optical cavities for the Purcell enhancement. Here, we demonstrate position- and polarization-controlled single-photon emitters in monolayer WSe2. A tensile strain of ∼0.2% was applied to monolayer WSe2 by placing it onto a dielectric rod structure with a nanosized gap. Excitons were localized in the nanogap sites, resulting in the generation of linearly polarized single-photon emission with a g(2) of ∼0.1 at 4 K. Additionally, we measured the abrupt change in polarization of single photons with respect to the nanogap size. Our robust spatial and polarization control of emission provides an efficient way to demonstrate deterministic and scalable single-photon sources by integrating with nanocavities.

Heterogeneous deformation of two-dimensional materials for emerging functionalities.

Atomically thin 2D materials exhibit strong intralayer covalent bonding and weak interlayer van der Waals interactions, offering unique high in-plane strength and out-of-plane flexibility. While atom-thick nature of 2D materials may cause uncontrolled intrinsic/extrinsic deformation in multiple length scales, it also provides new opportunities for exploring coupling between heterogeneous deformations and emerging functionalities in controllable and scalable ways for electronic, optical, and optoelectronic applications. In this review, we discuss (i) the mechanical characteristics of 2D materials, (ii) uncontrolled inherent deformation and extrinsic heterogeneity present in 2D materials, (iii) experimental strategies for controlled heterogeneous deformation of 2D materials, (iv) 3D structure-induced novel functionalities via crumple/wrinkle structure or kirigami structures, and (v) heterogeneous strain-induced emerging functionalities in exciton and phase engineering. Overall, heterogeneous deformation offers unique advantages for 2D materials research by enabling spatial tunability of 2D materials' interactions with photons, electrons, and molecules in a programmable and controlled manner.

Ultraviolet to Mid-Infrared Emissivity Control by Mechanically Reconfigurable Graphene.

Spectral emissivity control is critical for optical and thermal management in the ambient environment because solar irradiance and atmospheric transmissions occur at distinct wavelength regions. For instance, selective emitters with low emissivity in the solar spectrum but high emissivity in the mid-infrared can lead to significant radiative cooling. Ambient variations require not only spectral control but also a mechanism to adjust the emissivity. However, most selective emitters are fixed to specific wavelength ranges and lack dynamic control mechanisms. Here we show ultraviolet to mid-infrared emissivity control by mechanically reconfiguring graphene, in which stretching and releasing induce dynamic topographic changes. We fabricate crumpled graphene with pitches ranging from 40 nm to 10 µm using deformable substrates. Our measurements and computations show that 140 nm-pitch crumpled graphene offers ultraviolet emissivity control in 200-300 nm wavelengths whereas 10 µm-pitch crumpled graphene offers mid-infrared emissivity control in 7-19 µm wavelengths. Significant emissivity changes arise from interference induced by the periodic topography and selective transmissivity reductions. Dynamic stretching and releasing of 140 nm and 10 µm pitch crumpled graphene show reversible emissivity peak changes at 250 nm and at 9.9 µm wavelengths, respectively. This work demonstrates the unique potential of crumpled graphene as a reconfigurable optical and thermal management platform.

Electrical Double Layer of Supported Atomically Thin Materials.

The electrical double layer (EDL), consisting of two parallel layers of opposite charges, is foundational to many interfacial phenomena and unique in atomically thin materials. An important but unanswered question is how the "transparency" of atomically thin materials to their substrates influences the formation of the EDL. Here, we report that the EDL of graphene is directly affected by the surface energy of the underlying substrates. Cyclic voltammetry and electrochemical impedance spectroscopy measurements demonstrate that graphene on hydrophobic substrates exhibits an anomalously low EDL capacitance, much lower than what was previously measured for highly oriented pyrolytic graphite, suggesting disturbance of the EDL ("disordered EDL") formation due to the substrate-induced hydrophobicity to graphene. Similarly, electrostatic gating using EDL of graphene field-effect transistors shows much lower transconductance levels or even no gating for graphene on hydrophobic substrates, further supporting our hypothesis. Molecular dynamics simulations show that the EDL structure of graphene on a hydrophobic substrate is disordered, caused by the disruption of water dipole assemblies. Our study advances understanding of EDL in atomically thin limit.

Heart Rate Change While Drowsy Driving.

Heart rate (HR) change during sleepy driving has never been investigated. Healthy volunteers who planned to drive a long distance were recruited and monitored with a 24-hour Holter. Six healthy volunteers were enrolled. Their mean driving time was 297.7 ± 111 minutes. Mean duration of sleepy time while driving was 27 ± 24.5 minutes. Driving HR showed a trend for increment as compared to day time mean HR, from 85 ± 5.6 to 89.8 ± 5.6 beats/min (by 7%) (P = 0.093). Mean HR while sleepy driving significantly decreased to 81.5 ± 9.2 beats/min by 9.3% ± 7.4% (P = 0.046). This pilot study for the first time demonstrated that HR decreased while sleepy driving.

Diagnosis and classification of kidney transplant rejection using machine learning-assisted surface-enhanced Raman spectroscopy using a single drop of serum.

The quest to reduce kidney transplant rejection has emphasized the urgent requirement for the development of non-invasive, precise diagnostic technologies. These technologies aim to detect antibody-mediated rejection (ABMR) and T-cell-mediated rejection (TCMR), which are asymptomatic and pose a risk of potential kidney damage. The protocols for managing rejection caused by ABMR and TCMR differ, and diagnosis has traditionally relied on invasive biopsy procedures. Therefore, a convergence system using a nano-sensing chip, Raman spectroscopy, and AI technology was introduced to facilitate diagnosis using serum samples obtained from patients with no major abnormality, ABMR, and TCMR after kidney transplantation. Tissue biopsy and Banff score analysis were performed across the groups for validation, and 5 µL of serum obtained at the same time was added onto the Au-ZnO nanorod-based Surface-Enhanced Raman Scattering sensing chip to obtain Raman spectroscopy signals. The accuracy of machine learning algorithms for principal component-linear discriminant analysis and principal component-partial least squares discriminant analysis was 93.53% and 98.82%, respectively. The collagen (an indicative of kidney injury), creatinine, and amino acid-derived signals (markers of kidney function) contributed to this accuracy; however, the high accuracy was primarily due to the ability of the system to analyze a broad spectrum of various biomarkers.

Strain modulation in crumpled Si nanomembranes: Light detection beyond the Si absorption limit.

Although Si is extensively used in micro-nano electronics, its inherent optical absorption cutoff at 1100-nm limits its photonic and optoelectronic applications in visible to partly near infrared (NIR) spectral range. Recently, strain engineering has emerged as a promising approach for extending device functionality via tuning the material properties, including change in optical bandgap. In this study, the reduction in bandgap with applied strain was used for extending the absorption limit of crystalline Si up to 1310 nm beyond its intrinsic bandgap, which was achieved by creating the crumpled structures in Si nanomembranes (NMs). The concept was used to develop a prototype NIR image sensor by organizing metal-semiconductor-metal-configured crumpled Si NM photosensing pixels in 6 × 6 array. The geometry-controlled, self-sustained strain induction in Si NMs provided an exclusive photon management with shortening of optical bandgap and enhanced photoresponse beyond the conventional Si absorption limit.

Probiotic Potential of Bacillus Subtilis Strain I3: Antagonistic Activity Against Chalkbrood Pathogen and Pesticide Degradation for Enhancing Honeybee Health.

To explore the potential of probiotic candidates beneficial for honeybee health through the modulation of the gut microbiome, bee gut microbes were isolated from bumblebee (Bombus terrestris) and honeybee (Apis mellifera) using diverse media and cultural conditions. A total of 77 bee gut bacteria, classified under the phyla Proteobacteria, Firmicutes, and Actinobacteria, were identified. The antagonistic activity of the isolates against Ascosphaera apis, a fungal pathogen responsible for chalkbrood disease in honeybee larvae, was investigated. The highest growth inhibition percentage against A. apis was demonstrated by Bacillus subtilis strain I3 among the bacterial strains. The presence of antimicrobial peptide genes in the I3 strain was detected using PCR amplification of gene fragments encoding surfactin and fengycin utilizing specific primers. The export of antimicrobial peptides by the I3 strain into growth medium was verified using liquid chromatography coupled with mass spectroscopy. Furthermore, the strain's capabilities for degrading pesticides, used for controlling varroa mites, and its spent growth medium antioxidant activity were substantiated. The survival rate of honeybees infected with (A) apis was investigated after feeding larvae with only medium (fructose + glucose + yeast extract + royal jelly), (B) subtilis I3 strain, A. apis with medium and I3 strain + A. apis with medium. Honeybees receiving the I3 strain + A. apis exhibited a 50% reduction in mortality rate due to I3 strain supplementation under experimental conditions, compared to the control group. In silico molecular docking revealed that fengycin hydrolase from I3 strain effectively interacted with tau-fluvalinate, suggesting its potential in bee health and environmental protection. Further studies are needed to confirm the effects of the I3 strain in different populations of honey bees across several regions to account for genetic and environmental variations.

Immunoprotective Effect of Liver Allograft on Patients with Combined Liver and Kidney Transplantation.

BACKGROUND Simultaneous liver-kidney transplantation (SLKT) and kidney transplantation (KT) after liver transplantation (LT) provide potential treatment options for patients with end-stage liver and kidney disease. There is increasing attention being given to liver-kidney transplantation (LTKT), particularly regarding the immune-protective effects of the liver graft. This retrospective, single-center, observational study aimed to evaluate the clinical outcomes of KT in LTKT patients - either SLKT or KT after LT (KALT) - compared to KT alone (KTA). MATERIAL AND METHODS We included patients who underwent KT between January 2005 and December 2020, comprising a total of 4312 patients divided into KTA (n=4268) and LTKT (n=44) groups. The LTKT group included 11 SLKT and 33 KALT patients. To balance the difference in sample sizes between the 2 groups, we performed 3: 1 propensity score matching (PSM). RESULTS There was no significant difference in graft survival between the groups. However, the LTKT group exhibited significantly superior rejection-free survival compared to the KTA group (P.

Ultrasound-guided cervical periradicular steroid injection for cervical radicular pain: relevance of spread pattern and degree of penetration of contrast medium.

BACKGROUND AND OBJECTIVES: Ultrasound-guided cervical periradicular steroid injection (US-CPSI) is an attractive alternate to conventional C-arm guided transforaminal epidural injection for treatment of cervical radicular pain. We compared the technical differences and clinical outcomes between these two techniques. METHODS: Following ultrasound-guided needle placement, the extent of contrast media spread and the degree of tissue penetration were monitored by real-time fluoroscopy at the time of cervical periradicular injection in 59 patients. The spread pattern was judged to be medial foramen (medial bisector of foramen), lateral foramen (lateral bisector of foramen), or extraforaminal. The degree of tissue penetration was classified into periradicular, pararadicular, and intramuscular based on the penetration characteristics. Ultrasonographic images were categorized into crescent, perineuronal protruding, and intramuscular types. These groups were then correlated with clinical outcomes. RESULTS: The actual distance between the ultrasound-guided needle position and fluoroscopic target point was 1.9 and 2.3 cm in the oblique and anteroposterior view, respectively. Despite a difference in ultrasound and fluoroscopic end points, contrast dye spread was found to reach lateral foramen in 53%, medial foramen in 34%, and extraforaminal in 13% of the subjects. Analysis of postprocedural pain reduction (PPPR) showed significantly the better outcomes in periradicular and pararadicular penetration, medial and lateral, and crescent and perineural protruding type without subgroup differences than intramuscular penetration, extraforaminal spread, and ultrasonographic images of intramuscular type (P < 0.001). Analysis of clinical overall outcome showed favorable outcome in the groups with better results of PPPR. CONCLUSION: Our preliminary data suggest that the technique of UP-CPSI can provide an adequate local spread pattern, tissue penetration for treatment of cervical radicular pain.

Comparison of functional and histological outcomes after intralesional, intracisternal, and intravenous transplantation of human bone marrow-derived mesenchymal stromal cells in a rat model of spinal cord injury.

BACKGROUND: Few studies have compared methods of stem cell transplantation. The aim of the present study was to determine the optimal method of delivery of therapeutic stem cells in spinal cord injury (SCI). We compared functional and histologic outcomes after administration of human bone marrow stromal cells (BMSCs) by intralesional (ILT), intracisternal (ICT), and intravenous transplantation (IVT). METHOD: A rat model of spinal cord injury was produced by dropping a 10-g weight, 2 mm in diameter, onto the exposed spinal cords of animals from a height of 25 mm. In each treatment group, 24 animals were randomly assigned for functional assessment and 24 for histologic examination. BMSCs (3 × 10(5), ILT; 1 × 10(6), ICT; 2 × 10(6), IVT) were transplanted 1 week after SCI in numbers determined in previous studies. Basso-Beattie-Bresnahan scoring was performed in all animals weekly for 6 weeks. Spinal cord specimens were obtained from eight animals in each group 2, 4, and 6 weeks after SCI. Viable BMSCs were counted in six sagittal sections from each spinal cord. RESULTS: All three treatment groups showed improved functional recovery compared to controls beginning 2 weeks after stem cell injection (P < 0.01). The ICT group showed the best functional recovery, followed by the ILT and IVT groups, respectively (P < 0.01). Histological analysis showed the largest number of viable BMSCs in the ILT group, followed by the ICT and IVT groups, respectively (P < 0.01). CONCLUSIONS: ICT may be the safest and most effective method for delivering stem cells and improving functional outcome in SCI when no limits are placed on the number of cells transplanted. As research on enhancing engraftment rates advances, further improvement of functional outcome can be expected.

Emerging Role of NRF2 Signaling in Cancer Stem Cell Phenotype.

Cancer stem cells (CSCs) are a small population of tumor cells characterized by self-renewal and differentiation capacity. CSCs are currently postulated as the driving force that induces intra-tumor heterogeneity leading to tumor initiation, metastasis, and eventually tumor relapse. Notably, CSCs are inherently resistant to environmental stress, chemotherapy, and radiotherapy due to high levels of antioxidant systems and drug efflux transporters. In this context, a therapeutic strategy targeting the CSC-specific pathway holds a promising cure for cancer. NRF2 (nuclear factor erythroid 2-like 2; NFE2L2) is a master transcription factor that regulates an array of genes involved in the detoxification of reactive oxygen species/electrophiles. Accumulating evidence suggests that persistent NRF2 activation, observed in multiple types of cancer, supports tumor growth, aggressive malignancy, and therapy resistance. Herein, we describe the core properties of CSCs, focusing on treatment resistance, and review the evidence that demonstrates the roles of NRF2 signaling in conferring unique properties of CSCs and the associated signaling pathways.

Transplant-associated Kaposi's sarcoma in a kidney allograft: a case report.

Kaposi's sarcoma (KS) is a disease that is not widely known among the general public, but has a high prevalence among organ transplant recipients. Here, we present a rare case of intragraft KS after kidney transplantation. A 53-year-old woman who had been on hemodialysis due to diabetic nephropathy underwent deceased-donor kidney transplantation on December 7, 2021. Approximately 10 weeks after kidney transplantation, her creatinine level increased to 2.99 mg/dL. Upon examination, ureter kinking was confirmed between the ureter orifices and the transplanted kidney. As a result, percutaneous nephrostomy was performed, and a ureteral stent was inserted. During the procedure, bleeding occurred due to a renal artery branch injury, and embolization was performed immediately. Subsequently, kidney necrosis and uncontrolled fever developed, leading to graftectomy. Surgical findings revealed that the kidney parenchyma was necrotic as a whole, and lymphoproliferative lesions had formed diffusely around the iliac artery. These lesions were removed during graftectomy, and a histological examination was performed. The kidney graft and lymphoproliferative lesions were diagnosed as KS based on a histological examination. We report a rare case in which a recipient developed KS in the kidney allograft as well as in adjacent lymph nodes.

Comparison of long-term outcomes in simultaneous pancreas-kidney transplant versus simultaneous deceased donor pancreas and living donor kidney transplant.

Simultaneous deceased donor pancreas and living donor kidney transplant (SPLK) has certain advantages over conventional simultaneous pancreas-kidney transplant (SPK) and may be beneficial for overcoming the paucity of organs needed for diabetic patients requiring transplant. We compared the clinical outcomes of patients who underwent either SPK (n = 149) or SPLK (n = 46) in terms of pre- and post-transplantation variables, development of de novo DSA, occurrence of biopsy-proven acute rejection (BPAR), and graft survival rates. There were no significant differences in the baseline characteristics between the SPK and SPLK groups except for the shorter cold ischemic time of kidney grafts, shorter duration of diabetes, older age of pancreas graft-donors, and younger age of kidney graft-donors in the SPLK group. Our results showed that the death-censored pancreas graft survival rate was lower in the SPLK group. In addition, the incidence of BPAR of the pancreas graft was higher in the SPLK group. There was no significant difference in the presence of de novo DSA and the rates of kidney graft failure, kidney BPAR, and mortality. Our results show that SPLK can be considered an alternative option for SPK although higher incidences of BPAR and graft failure of pancreas after SPLK need to be overcome.

Dynamically tuning friction at the graphene interface using the field effect.

Dynamically controlling friction in micro- and nanoscale devices is possible using applied electrical bias between contacting surfaces, but this can also induce unwanted reactions which can affect device performance. External electric fields provide a way around this limitation by removing the need to apply bias directly between the contacting surfaces. 2D materials are promising candidates for this approach as their properties can be easily tuned by electric fields and they can be straightforwardly used as surface coatings. This work investigates the friction between single layer graphene and an atomic force microscope tip under the influence of external electric fields. While the primary effect in most systems is electrostatically controllable adhesion, graphene in contact with semiconducting tips exhibits a regime of unexpectedly enhanced and highly tunable friction. The origins of this phenomenon are discussed in the context of fundamental frictional dissipation mechanisms considering stick slip behavior, electron-phonon coupling and viscous electronic flow.

Robot-assisted kidney transplantation in a morbidly obese patient with incisional hernia reconstruction and abdominoplasty: a case report.

Performing kidney transplantations in patients with morbid obesity presents unique challenges using the conventional retroperitoneal approach. Robot-assisted kidney transplantation (RAKT) offers several advantages, such as better access to hard-to-reach areas. A 56-year-old morbidly obese woman presented with end-stage renal disease due to diabetic nephropathy. The patient had a history of obesity for over 20 years, with a peak body mass index (BMI) of 46.9 kg/m2. Before transplantation, she successfully reduced her BMI to 28.9 kg/m2, but was left with excessive skin folds. The surgery began with the removal of the sac from the incisional hernia and umbilical hernia, which was then used as the site for the GelPOINT port. The da Vinci X robot system was utilized to perform RAKT. After completing RAKT, the plastic surgery team initiated abdominal reconstruction involving panniculectomy, followed by hernial reconstruction and abdominoplasty. The patient's postoperative course was uneventful, and she was discharged on postoperative day 7. Her creatinine level was 0.69 mg/dL, and she did not experience any episodes of rejection during the 16 months following RAKT. This case report describes the successful combination of RAKT with incisional hernia reconstruction and abdominoplasty in a patient with morbid obesity.

Strain Engineering of Low-Dimensional Materials for Emerging Quantum Phenomena and Functionalities.

Recent discoveries of exotic physical phenomena, such as unconventional superconductivity in magic-angle twisted bilayer graphene, dissipationless Dirac fermions in topological insulators, and quantum spin liquids, have triggered tremendous interest in quantum materials. The macroscopic revelation of quantum mechanical effects in quantum materials is associated with strong electron-electron correlations in the lattice, particularly where materials have reduced dimensionality. Owing to the strong correlations and confined geometry, altering atomic spacing and crystal symmetry via strain has emerged as an effective and versatile pathway for perturbing the subtle equilibrium of quantum states. This review highlights recent advances in strain-tunable quantum phenomena and functionalities, with particular focus on low-dimensional quantum materials. Experimental strategies for strain engineering are first discussed in terms of heterogeneity and elastic reconfigurability of strain distribution. The nontrivial quantum properties of several strain-quantum coupled platforms, including 2D van der Waals materials and heterostructures, topological insulators, superconducting oxides, and metal halide perovskites, are next outlined, with current challenges and future opportunities in quantum straintronics followed. Overall, strain engineering of quantum phenomena and functionalities is a rich field for fundamental research of many-body interactions and holds substantial promise for next-generation electronics capable of ultrafast, dissipationless, and secure information processing and communications.