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This study aimed to explore the role and mechanism of DYRK1a regulating ferroptosis of cardiomyocytes during myocardial ischemia–reperfusion injury (MIRI). H9c2 cells treated with oxygen–glucose deprivation/reoxygenation (OGD/R) were used as MIRI cell models and transfected with sh‐DYRK1a or/and erastin. Cell viability, apoptosis, and DYRK1a mRNA/protein expression were measured accordingly. The levels of reactive oxygen species (ROS), iron, malondialdehyde (MDA), and glutathione (GSH) were determined. The expression of ferroptosis‐related proteins (GPX4, SLC7A11, ACSL4, and TFR1) was detected using western blotting. The MIRI rat model was established to explore the possible role of DYRK1a suppression in cell injury and ferroptosis. OGD/R cells showed elevated mRNA and protein expression for DYRK1a. OGD/R cells transfected with sh‐DYRK1a showed elevated cell viability, GSH content, increased GPX4 and SLC7A11 expression, suppressed iron content, MDA, ROS, ACSL4, and TFR1 expression, and reduced apoptosis rate, whereas co‐transfection of sh‐DYRK1a with erastin reversed the attenuation of sh‐DYRK1a on MIRI. The suppressive effect of sh‐DYRK1a on MI/R injury was confirmed in an MIRI rat model. DYRK1a mediates ferroptosis of cardiomyocytes to deteriorate MIRI progression.

There is increasing evidence linking long-term fine particulate matter (PM2.5) exposure to negative health effects. However, the relative influence of each component of PM2.5on health risk is poorly understood. In a cohort study in the contiguous United States between 2000 and 2017, we examined the effect of long-term exposure to PM2.5main components and all-cause mortality in older adults who had to be at least 65 years old and enrolled in Medicare. We estimated the yearly mean concentrations of six key PM2.5compounds, including black carbon (BC), organic matter (OM), soil dust (DUST), nitrate (NO3–), sulfate (SO42–), and ammonium (NH4+), using two independently sourced well-validated prediction models. We applied Cox proportional hazard models to evaluate the hazard ratios for mortality and penalized splines for assessing potential nonlinear concentration–response associations. Results suggested that increased exposure to PM2.5mass and its six main constituents were significantly linked to elevated all-cause mortality. All components showed linear concentration–response relationships in the low exposure concentration ranges. Our research indicates that long-term exposure to PM2.5mass and its essential compounds are strongly connected to increased mortality risk. Reductions of fossil fuel burning may yield significant air quality and public health benefit.

Study Design: Retrospective cohort study.Objective: Overcorrection in adult spinal deformity (ASD) surgery may lead to proximal junctional kyphosis (PJK) because of posterior spinal displacement. The aim of this paper is to determine if the L1 position relative to the gravity line (GL) is associated with PJK.Methods: ASD patients fused from the lower thoracic spine to sacrum by 4 spine surgeons at our hospital were retrospectively studied. Lumbar-only and upper thoracic spine fusions were excluded. Spinopelvic parameters, the L1 plumb line (L1PL), L1 distance to the GL (L1-GL), and Roussouly type were measured.Results: One hundred fourteen patients met inclusion criteria (63 patients with PJK, 51 without). Mean age and follow up was 65.51 and 3.39 years, respectively. There was no difference between the PJK and the non-PJK groups in baseline demographics, pre-operative and immediate post-operative pelvic incidence-lumbar lordosis mismatch, sagittal vertical axis, or coronal Cobb. The immediate postoperative L1-GL was -7.24 cm in PJK and -3.45 cm in non-PJK (P< 0.001), L1PL was 1.71 cm in PJK and 3.07 cm in non-PJK (P= 0.004), and PT (23.76° vs 18.90°, P= 0.026) and TK (40.56° vs 31.39°, P< 0.001) were larger in PJK than in non-PJK. After univariate and multivariate analyses, immediate postoperative TK and immediate postoperative L1-GL were independent risk factors for PJK without collinearity.Conclusions: A dorsally displaced L1 relative to the GL was associated with an increased risk of PJK after ASD surgery. The postoperative L1-GL distance may be a factor to consider during ASD surgery.

We construct zigzag graphene nanoribbon junctions for generating pure spin current through the photogalvanic effect (PGE) by first-principles calculations. Two devices with spatial inversion symmetry are designed, both consisting of three zigzag graphene nanoribbons (ZGNRs) that introduce either two carbon tetragons (“2-C4”) or two carbon hexagons (“2-C6”) as connectors. The results show that robust pure spin current without charge current can be generated in both structures. The mechanism originates from the spatial inversion antisymmetric spin density as well as the spatial inversion symmetry of the geometrical structures. Furthermore, when more connectors are involved, we generalize that for structures with carbon tetragons as connectors, an even number of connectors are required to generate pure spin currents, while for structures with carbon hexagon connectors, any number of connectors can form pure spin currents. In addition, we find that larger pure spin currents can be obtained in the case of using hexagons as connectors. These findings provide a scheme for obtaining pure spin currents based on graphene nanoribbons, which has important reference implications for the design of spintronic devices with composite nanostructures.

Purpose: While posterior spinal instrumentation and fusion (PSIF) for severe adolescent idiopathic scoliosis (AIS) is the gold standard, anterior vertebral body tethering (AVBT) is becoming an alternative for select cases. Several studies have compared technical outcomes for these two procedures, but no studies have compared post-operative pain and recovery. Methods: In this prospective cohort, we evaluated patients who underwent AVBT or PSIF for AIS for a period of 6 weeks after operation. Pre-operative curve data were obtained from the medical record. Post-operative pain and recovery were evaluated with pain scores, pain confidence scores, PROMIS scores for pain behavior, interference, and mobility, and functional milestones of opiate use, independence in activities of daily living (ADLs), and sleeping. Results: The cohort included 9 patients who underwent AVBT and 22 who underwent PSIF, with a mean age of 13.7 years, 90% girls, and 77.4% white. The AVBT patients were younger (p= 0.03) and had fewer instrumented levels (p= 0.03). Results were significant for decreased pain scores at 2 and 6 weeks after operation (p= 0.004, and 0.030), decreased PROMIS pain behavior at all time points (p= 0.024, 0.049, and 0.001), decreased pain interference at 2 and 6 weeks post-operative (p= 0.012 and 0.009), increased PROMIS mobility scores at all time points (p= 0.036, 0.038, and 0.018), and faster time to functional milestones of weaning opiates, independence in ADLs, and sleep (p= 0.024, 0.049, and 0.001). Conclusion: In this prospective cohort study, the early recovery period following AVBT for AIS is characterized by less pain, increased mobility, and faster recovery of functional milestones, compared with PSIF. Level of evidence: IV.

Background and context: In patients with adolescent idiopathic scoliosis (AIS) of main thoracic and lumbar spine regions, combined anterior thoracic vertebral body tethering and posterior lumbar spine tethering (ATVBT/PLST) is a novel non-fusion treatment option for growth modulation and conservation of motion. Methods: Fourteen patients with AIS who underwent ATVBT/PLST with at least 2-year follow-up were included. Primary outcomes included quality of life as assessed by SRS-22 instruments, radiographic analysis, and revision operations. We secondarily reported perioperative metrics and post-operative opiate morphine equivalents (OME). Clinical success was defined as patients who achieved skeletal maturity with ≤ 30° curve magnitude of both their main thoracic and thoracolumbar/lumbar curves and who did not undergo posterior spine instrumentation and fusion (PSIF). Results: Patients had a mean age of 11.6 years (range 10–14 years), majority were girls (92%), and mean follow-up was 3.0 years (range 2–4.8 years). All patients were skeletally immature with a Risser ≤ 2. Included curves were Lenke 1C, 3C, or 6C. Mean preoperative curve magnitudes were 53° ± 8° (range 45°–65°) main thoracic and 49° ± 9° (range 40°–62°) thoracolumbar/lumbar curves. At most recent follow-up, patients had a mean main thoracic curve of 29° ± 8° (range 15°–40°) and a mean thoracolumbar/lumbar curve of 20° ± 15° (range 4°–35°). 50% required a revision operation. Cable breakage occurred in 43%, which did not always require revision. One patient progressed to thoracic fusion, but no patient underwent lumbar fusion. Patients had a mean SRS-22 outcome score of 4.2 ± 0.4. Conclusions: ATVBT/PLST is a potential alternative to spine fusion for select immature patients with AIS at a minimum 2-year follow-up. ATVBT/PLST potentially offers motion conservation at the cost of a higher revision rate. Further study and reporting of results are necessary to refine indications and techniques, which in turn will improve outcomes of this procedure. Level of evidence: Level IV—Case series without comparative group.

Study Design: Retrospective cohort.Objective: Reoperation to lumbar spinal fusion creates significant burden on patient quality of life and healthcare costs. We assessed rates, etiologies, and risk factors for reoperation following elective 1 to 2 level lumbar fusion.Methods: Patients undergoing elective 1 to 2 level lumbar fusion were identified using the Health Care Utilization Project (HCUP) state inpatient databases from Florida and California. Patients were tracked for 5 years for any subsequent lumbar fusion. Cox proportional hazard analyses for reoperation were assessed using the following covariates: fusion approach type, age, race, Charlson comormidity index, gender, and length of stay. Distribution of etiologies for reoperation was then assessed.Results: 71, 456 patients receiving elective 1 to 2 level lumbar fusion were included. A 5-year reoperation rate of 13.53% and mortality rate of 2.22% was seen. Combined anterior-posterior approaches (HR = 0.904, p < 0.05) and TLIF (HR = 0.867, p < 0.001) were associated with reduced risk of reoperation compared to stand-alone anterior approaches and non-TLIF posterior approaches. Age, gender, and number of comorbidities were not associated with risk of reoperation. From 1 to 5 years, degenerative disease rose from 43.50% to 50.31% of reoperations; mechanical failure decreased from 37.65% to 29.77%.Conclusions: TLIF and combined anterior-posterior approaches for 1 to 2 level lumbar fusion are associated with the lowest rate of reoperation. Number of comorbidities and age are not predictive of reoperation. Primary etiologies leading to reoperation were degenerative disease and mechanical failure. Mortality rate is not increased from baseline following 1 to 2 level lumbar fusion.

The surgical goals for pediatric scoliosis surgery are to create a balanced, stable spine, to preserve range of motion (ROM) especially in the lumbar spine, and to avoid complications such as revision surgery (RS) or adding on phenomenon (AO). We describe a posterior scoliosis surgical method using intravertebral interpedicle (IVIP) constructs for limited apical fusion within the major structural curve(s) and correction of the deformity above or below the fusion with posterolateral vertebral tethering (PLVT) utilizing polyethylene terephthalate bands.

Although laparoscopic technology has achieved rapid development in the surgical field, it has not been applied to liver transplantation, primarily because of difficulties associated with laparoscopic vascular anastomosis. In this study, we introduced a new magnetic-assisted vascular anastomosis technique and explored its application in laparoscopic liver transplantation in pigs.

Background: Small intestinal monomorphic–epitheliotropic intestinal T-cell lymphoma (MEITL) is a rare aggressive T-cell lymphoma originating in the gastrointestinal tract. This study aimed to investigate the clinicopathological features, immunophenotypes, and molecular genetic changes of MEITL. Methods: The clinicopathological data for three patients with surgically resected MEITL of the small intestine were collected. Next, immunohistochemical labeling, Epstein–Barr virus (EBV) in situ hybridization, assessment of clonal rearrangement of T-cell receptor (TCR) genes, and next-generation sequencing (NGS) were performed. Results: Of the three patients, two were male and one was female, with ages of 61, 67, and 73 years, respectively. Clinical manifestations were predominantly abdominal pain and distension. Histopathology revealed infiltrative growth of small-to-medium-sized lymphocytes with a consistent morphology between the intestinal walls, accompanied by an obvious pro-epithelial phenomenon. The expression of CD3, CD8, CD43, CD56, TIA-1, CD103, H3K36me3, and Bcl-2 was detected, and the Ki-67 proliferation index ranged from 50% to 80%. All three patients tested negative for EBER. However, monoclonal rearrangement of the TCR gene was detected in them. NGS testing showed a JAK3mutation in all three cases. Further, STAT5B, SETD2, and TP53mutations were each observed in two cases, and a BCORmutation was found in one case. All patients were treated with chemotherapy after surgery. Two patients died 7 and 15 month post-operation, and one patient survived for 5 months of follow-up. Conclusions: Our findings demonstrate that mutations in JAK3and STAT5Bof the JAK/STAT pathway and inactivation of the oncogene SETD2markedly contribute to the lymphomagenesis of MEITL.

Introduction: Although matching lumbar lordosis (LL) with pelvic incidence (PI) is an important surgical goal for adult spinal deformity (ASD), there is concern that overcorrection may lead to proximal junctional kyphosis (PJK). We introduce the upper instrumented vertebra–femoral angle (UIVFA) as a measure of appropriate postoperative position in the setting of lower thoracic to pelvis surgical correction for patients with sagittal imbalance. We hypothesize that a more posterior UIV position in relation to the center of the femoral head is associated with an increased risk of PJK given compensatory hyperkyphosis above the UIV. Methods: In this retrospective cohort study, adult patients undergoing lower thoracic (T9–T12) to pelvis correction of ASD with a minimum of 2-year follow-up were included. UIVFA was measured as the angle subtended by a line from the UIV centroid to the femoral head center to the vertical axis. Patients who developed PJK and those who did not were compared with preoperative and postoperative UIVFA as well as change between postoperative and preoperative UIVFA (deltaUIVFA). Results: Of 119 patients included with an average 3.6-year follow-up, 51 (42.9%) had PJK and 24 (20.2%) had PJF. Patients with PJK had significantly higher postoperative UIVFA (12.6 ± 4.8° vs. 9.4 ± 6.6°, p= 0.04), deltaUIVFA (6.1 ± 7.6° vs. 2.1 ± 5.6°, p&lt; 0.01), postoperative pelvic tilt (27.3 ± 9.2 vs. 23.3 ± 11, p= 0.04), postoperative lumbar lordosis (47.7 ± 13.9° vs. 42.4 ± 13.1, p= 0.04) and postoperative thoracic kyphosis (44.9 ± 13.2 vs. 31.6 ± 18.8) than patients without PJK. With multivariate logistic regression, postoperative UIVFA and deltaUIVFA were found to be independent risk factors for PJK (p&lt; 0.05). DeltaUIVFA was found to be an independent risk factor for PJF (p&lt; 0.05). A receiver operating characteristic (ROC) curve for UIVFA as a predictor for PJK was established with an area under the curve of 0.67 (95% CI 0.59–0.76). Per the Youden index, the optimal UIVFA cut-off value is 11.5 degrees. Conclusion: The more posterior the UIV is from the femoral head center after lower thoracic to pelvis surgical correction for ASD, the more patients are at risk for PJK. The greater the magnitude of posterior translation of the UIV from the femoral head center from preop to postop, the greater the likelihood for PJF.

Combination treatments are more effective than conventional monotherapy in combating cancer. Herein, a multifunctional prodrug BDP-L-CPTwas rationally engineered and prepared by the conjugation of a boron dipyrromethene (BDP)-based photosensitizer (PS) to the active site of the chemotherapeutic drug camptothecin (CPT) via a phenyl benzoate group. After modification, the cytotoxicity of CPT was locked. Moreover, the fluorescence emission at 430 nm from the CPT component in the prodrug was substantially inhibited through the intramolecular fluorescence resonance energy transfer process. The phenyl benzoate linker in BDP-L-CPTcould be selectively cleaved by exogenous carboxylesterase in phosphate-buffered saline solution and endogenous carboxylesterase overexpressed in cancer cells, which was followed by self-immolation to release free CPT. The drug release process could be monitored by the turn-on of CPT fluorescence in solution and cells. Owing to the combination of site-specific chemotherapy with light-driven photodynamic therapy, the IC50values of the prodrug BDP-L-CPTagainst HepG2 human hepatocellular carcinoma and HeLa human cervical carcinoma cells were lower than those of the controls, BDP-COOHand CPT. The combined antitumor effects of the prodrug BDP-L-CPTwere also observed in the mice bearing H22 tumors. Furthermore, BDP-L-CPThad a more prolonged blood circulation time in mice than CPT, which is beneficial to persistent therapy. This study may provide a promising strategy for a selective combination cancer treatment by conjugating a prodrug to a PS.

Purpose: To compare direct costs of index and revision operations of thoracic posterior spinal instrumented fusion (TPSIF) and thoracic anterior spinal tethering (TAST) for adolescent idiopathic thoracic scoliosis in children. Methods: Children (ages 11–18 years) who underwent TPSIF and TAST (2/2013–9/2019) were reviewed. Follow-up &lt; 2 years and cervical instrumentation and/or instrumentation of a lumbar level at L3 or below were exclusion criteria. Patient demographics, radiographic curve magnitude, index operations and postoperative data, as well as indications for revisions/readmissions were collected. Direct costs were identified and compared for index and revision operations during follow-up. Results: One hundred and four patients were included (TPSIF: 78; TAST: 25). TAST procedures were performed in children significantly younger and for smaller curve magnitudes. They had significantly fewer levels instrumented, shorter operating room (OR) times, and less estimated blood loss (EBL). After operation, a significantly higher percentage of TAST were admitted to ICU. Hospital length of stay (LOS) was similar between groups. Index operations’ average direct costs were significantly higher for TAST than TPSIF ($52,947 v.$46,641; p= 0.02). Major cost drivers for both groups were implants, OR services, post-anesthesia care unit (PACU), and room/board. Conclusions: Index operations’ average direct costs were statistically similar between TPSIF and TAST for adolescent idiopathic scoliosis. Major cost drivers were implants, OR services, PACU, and room/board. TAST index operations’ direct costs and associated direct costs for implants and room/board were significantly higher, while their anesthesia and OR services were significantly lower than TPSIF. TAST revisions were for overcorrection and curve progression, while TPSIF revisions were most commonly for junctional deformity. Overall average direct costs for revisions were similar despite revision rates being higher for TAST. Level of evidence: III.

Purpose To evaluate the ability of patients to return to work following anteromedialization (AMZ) tibial tubercle osteotomy (TTO) due to isolated patellofemoral osteoarthritis or pain.Methods Consecutive patients undergoing AMZ TTO were reviewed retrospectively at a minimum of 1 year postoperatively. Patients completed a subjective work questionnaire, a visual analog scale for pain, as well as a Kujala questionnaire and satisfaction questionnaire.Results Fifty-seven patients (61 knees; average age: 32.7 ± 9.6 years) were contacted at an average follow-up of 4.86 ± 2.84 years postoperatively. The preoperative Kujala score improved from 55.7 ± 17.8 to 84.6 ± 15.8 at final follow-up (P< 0.001). Thirty-seven patients (64.9%) were employed within 3 years prior to surgery and 34 patients (91.9%) were able to return to work by 2.8 ± 2.6 months postoperatively. However, only 27 patients (73.0%) of patients were able to return to the same level of occupational intensity. Patients who held sedentary, light-, medium-, or high-intensity occupations were able to return to work at a rate of 100.0%, 93.8%, 77.8%, and 100.0% by 2.2 months, 3.0 months, 3.1 months, and 4.0 months, postoperatively. No patients underwent revision TTO or conversion to arthroplasty by the time of final follow-up.Conclusion In patients with focal patellofemoral osteoarthritis or pain, AMZ TTO provides a high rate of return to work (91.9%) by 2.8 ± 2.6 months postoperatively. Patients with higher intensity occupations may take longer to return to work than those with less physically demanding occupations.Level of Evidence III.

Long noncoding RNAs (lncRNAs) have been reported to exert important roles in tumors, including clear cell renal cell carcinoma (ccRCC). PVT1 is an important oncogenic lncRNA which has critical effects on onset and development of various cancers, however, the underlying mechanism of PVT1 functioning in ccRCC remains largely unknown. VHLdeficiency-induced HIF2α accumulation is one of the major factors for ccRCC. Here, we identified the potential molecular mechanism of PVT1 in promoting ccRCC development by stabilizing HIF2α. PVT1 was significantly upregulated in ccRCC tissues and high PVT1 expression was associated with poor prognosis of ccRCC patients. Both gain-of-function and loss-of function experiments revealed that PVT1 enhanced ccRCC cells proliferation, migration, and invasion and induced tumor angiogenesis in vitro and in vivo. Mechanistically, PVT1 interacted with HIF2α protein and enhanced its stability by protecting it from ubiquitination-dependent degradation, thereby exerting its biological significance. Meanwhile, HIF2α bound to the enhancer of PVT1 to transactivate its expression. Furthermore, HIF2α specific inhibitor could repress PVT1 expression and its oncogenic functions. Therefore, our study demonstrates that the PVT1/ HIF2α positive feedback loop involves in tumorigenesis and progression of ccRCC, which may be exploited for anticancer therapy.

Dielectric ceramic capacitors, with the advantages of high power density, fast charge-discharge capability, excellent fatigue endurance, and good high temperature stability, have been acknowledged to be promising candidates for solid-state pulse power systems. This review investigates the energy storage performances of linear dielectric, relaxor ferroelectric, and antiferroelectric from the viewpoint of chemical modification, macro/microstructural design, and electrical property optimization. Research progress of ceramic bulks and films for Pb-based and/or Pb-free systems is summarized. Finally, we propose the perspectives on the development of energy storage ceramics for pulse power capacitors in the future.

Poly (N -ethylaniline) (PNEA) composites with varying silicate content were fabricated on copper through a novel electropolymerized strategy in acidic solution. Thickness, compactness, conductivity and adhesive strength of the composite (PNEA-10Si) were optimized as silicate content reached 10 mM. Electrochemical, morphological and solution analyses were employed to evaluate the protective performance of PNEA and PNEA-10Si coatings for copper in 3.5 % NaCl solution. Results of electrochemical analyses indicated that as-prepared coatings retarded the oxygen reduction process efficiently for copper in 3.5 % NaCl solution, drained corrosion current density and elevated interfacial charge transfer resistance. Due to favorable barrier effect, compact structure and low porosity index, PNEA-10Si composite exhibited superior anti-corrosive performance, which was more tolerant than PNEA during long-time immersion. PNEA-10Si coated sample exhibited a stable topography after 144 h immersion with the minimum concentration of released ions revealing the improved protection capacity. Electronic/atomic-multiscale calculations were conducted to clarify the deposition and protection mechanism of as-prepared coatings. Outcomes of density functional theory corroborated that silicate is stabilized in the PNEA layer via electrostatic force; and immobile silicate positively contributed to the charge transfer barrier of the composite. Molecular dynamics simulations evidenced that the favorable compatibility between PNEA and silicate facilitated polymer deposition and confined in-situ ions diffusion. [ABSTRACT FROM AUTHOR]

Few-atom gold nanoclusters (AuNCs) have been fabricated and used for various fields owing to their remarkable optical and photophysical features. However, the rational design for the antibody-mediated synthesis of fluorescent AuNCs for direct antigen–antibody reactions remains unexplored. In this work, immunoglobulin G (IgG)-functionalized AuNCs (IgG-AuNCs) were successfully prepared via a facile and fast biomineralization process. The generated IgG-AuNCs can emit intense red fluorescence with a high photoluminescence quantum yield. Besides strong emission, the bioactivity of IgG on the IgG-AuNCs can be retained. Surface plasmon resonance measurements suggested that IgG-AuNCs can bind to goat anti-human IgG with an affinity constant of 6.21 × 10–8M. A simple detection method was then developed using a dot-blot immunoassay with IgG-AuNCs as fluorescent tags. Experimental results confirmed that the IgG-AuNC-based fluorescent reporters had many advantages such as low nonspecific adsorption and good photostability, offering immense potential for the development of efficient biosensors. This work can be extended to other specific antibodies to produce multifunctional AuNCs and utilized to detect and monitor targeted analytes and biological events of interest.

Study Design Retrospective comparative study.Objective To compare patient-reported physical activity between anterior thoracic vertebral body tethering and posterior lumbar spine tethering (ATVBT/PLST) and posterior spinal instrumentation and fusion (PSIF) with minimum 2 year follow-up.Methods Consecutive skeletally immature patients with idiopathic scoliosis and a thoracic and lumbar curve magnitude ≥40° who underwent either ATVBT/PLST or PSIF from 2015-2019 were included. The primary outcome was rate of returning to sport. Secondary outcomes included ability to bend and satisfaction with sport performance as well as weeks until return to sport, school, physical education (PE) classes, and running.Results Ten patients underwent ATVBT/PLST and 12 underwent PSIF. ATVBT/PLST patients reported significantly faster return to sport (13.5 weeks vs 27.9 weeks, P= .04), running (13.3 weeks vs 28.8 weeks, P= .02), and PE class (12.6 weeks vs 26.2 weeks, P= .04) compared to PSIF patients. ATVBT/PLST patients reported that they had to give up activities due to their ability to bend at lower rates than PSIF patients while reporting “no changes” in their ability to bend after surgery at higher rates than PSIF patients (0% vs 4% giving up activities and 70% vs 0% reporting no changes in bending ability for ATVBT/PLST and PSIF, respectively, P= .01). Compared to PSIF patients, ATVBT/PLST patients experienced less main thoracic and thoracolumbar/lumbar curve correction at most recent follow-up (thoracic: 41 ± 19% vs 69 ± 18%, P= .001; thoracolumbar/lumbar: 59 ± 25% vs 78 ± 15%, P= .02). No significant differences in the number of revision surgeries were observed between ATVBT/PLST and PSIF patients (4 (40%) and 1 (8%) for ATVBT/PLST and PSIF, respectively, P= .221).Conclusions ATVBT/PLST patients reported significantly faster rates of returning to sport, running, and PE. In addition, ATVBT/PLST patients were less likely to have to give up activities due to bending ability after surgery and reported no changes in their ability to bend after surgery more frequently than PSIF patients. However, the overall rate of return to the same or higher level of sport participation was high amongst both groups, with no significant difference observed between ATVBT/PLST and PSIF patients.

Spondylodiscitis (SD) is an infection of the intervertebral disc with involvement of the adjacent vertebral bodies. Diagnostic tests with CT-guided biopsy only provide a positive yield in 14%–48% of cases. Percutaneous endoscopic debridement and drainage (PEDD) has recently shown promise in the treatment of spondylodiscitis.

For solving the trade-off relationship of the polarization and breakdown electric field, ferroelectric films with high polarization are playing a critical role in energy storage capacitor applications, especially at moderate/low electric fields. In this work, we propose a multiscale structure (including defect, domain, and grain structures) synergetic optimization strategy to optimize the polarization behavior and energy storage performances of BiMg0.5Ti0.5O3(BMT) ferroelectric films by introducing Sr0.7La0.2TiO3(SLT) without compromising the breakdown strength. At a moderate electric field of 2917 kV/cm, a high discharge density of 72.2 J/cm3has been achieved in 0.9BMT-0.1SLT films, together with good frequency, thermal, and cycle stabilities for energy storage. Importantly, the phase difference Δφ is utilized to quantitatively evaluate the polarization switching mobility of the ferroelectric domain/PNRs at an external electric field stimulation. This research demonstrates that a multiscale structure optimization strategy could effectively regulate the energy storage performance, and ecofriendly BMT-based materials are promising candidates for next-generation energy storage capacitors, especially at moderate/low electric fields.

The interpretability of machine learning reveals associations between input features and predicted physical properties in models, which are essential for discovering new materials. However, previous works were mainly devoted to algorithm improvement, while the essential multi-scale characteristics are not well addressed. This paper introduces distortion modes of oxygen octahedrons as cross-scale structural features to bridge chemical compositions and material properties. Combining model-agnostic interpretation methods, we are able to achieve interpretability even using simple machine learning schemes and develop a predictive model of effective mass for a widely used material type, namely perovskite oxides. With this framework, we reach the interpretability of the model, understanding the trend of the effective mass without any prior background information. Moreover, we obtained the knowledge only available to experts, i.e., the interpretation of effective mass from the s–p orbitals hybridization of B-site cations and O2−in ABO3perovskite oxides.

Metal nanoclusters (MNCs) represent a promising class of materials for catalytic carbon dioxide and proton reduction as well as dihydrogen oxidation. In such reactions, multiple proton-coupled electron transfer (PCET) processes are typically involved, and the current understanding of PCET mechanisms in MNCs has primarily focused on the sequential transfer mode. However, a concerted transfer pathway, i.e., concerted electron–proton transfer (CEPT), despite its potential for a higher catalytic rate and lower reaction barrier, still lacks comprehensive elucidation. Herein, we introduce an experimental paradigm to test the feasibility of the CEPT process in MNCs, by employing Au18(SR)14(SR denotes thiolate ligand), Au22(SR)18, and Au25(SR)18–as model clusters. Detailed investigations indicate that the photoinduced PCET reactions in the designed system proceed via an CEPT pathway. Furthermore, the rate constants of gold nanoclusters (AuNCs) have been found to be correlated with both the size of the cluster and the flexibility of the Au–S framework. This newly identified PCET behavior in AuNCs is prominently different from that observed in semiconductor quantum dots and plasmonic metal nanoparticles. Our findings are of crucial importance for unveiling the catalytic mechanisms of quantum-confined metal nanomaterials and for the future rational design of more efficient catalysts.

0.5wt%MnO2-doped (1 − x)BaTiO3–xBiCoO3ceramics short as (1 − x)BT–xBC–M sintered in air and reducing atmosphere via solid-state process were investigated. The X-ray diffraction results showed that solid solubility in (1 − x)BT–xBC ceramics sintered in the air was higher than that in reducing atmosphere. (1 − x)BT–xBC–M ceramics sintered in air transformed from tetragonal to pseudo-cubic phase when x≥ 0.1. The scanning electron microscopy results indicated that the average grain size increased with the BC component increasing; however, opposite phenomena occurred in samples sintered in the reducing atmosphere. The dielectric temperature curves of samples sintered in reducing atmosphere were flatted with excellent insulation resistivity of an order of magnitude of 1013Ω·cm, while anomalous dielectric constant and dielectric loss of samples sintered in the air with deteriorated insulation resistivity of an order of magnitude of 107Ω·cm. The anti-reduction mechanism of (1 − x)BT–xBC–M system was explained by the “electron–hole” trapping effect and formation of defect dipoles MnTi″-VO··and 2CoTi′-VO··.

Capacitor is an important part of many electronic devices, so the temperature stability as one key parameter of capacitor needs to be improved constantly for meeting the requirements of various application temperature. Here, combined with the X-ray diffraction (XRD), selected area electron diffraction (SAED) and Vienna Ab-initio Simulation Package (VASP) calculation, it was confirmed that Ca ion can substitute the Ti site in the BaTi1-xCaxO3-x[BTC100×] (0 ≤ x ≤ 0.05) ceramics synthesized by solid-phase method which greatly improved the low-temperature stability of dielectric constant. Moreover, introducing Bi3+and Zn2+into BTC4 to form (1-y)BaTi0·96Ca0·04O2.96-yBi(Zn0·5Ti0.5)O3[(1-y)BTC4-yBZT] (0.1 ≤ y ≤ 0.2) ceramics can further improve the dielectric-temperature stability by means of diffused phase transition and core-shell structure. Most importantly, the 0.85BTC4-0.15BZT ceramics with a pseudocubic perovskite structure possessed a temperature coefficient of capacitance at 25 °C (TCC25°C) being less than ±15% over a wide temperature range of −55 °C–200 °C and a temperate dielectric constant (ε = 1060) and low dielectric loss (tanδ = 1.5%), which measure up to the higher standard in the current capacitor industry such as X9R requirements.

The use of metal ions to bridge the fluorescent materials to target analytes has been demonstrated to be a promising way to sensor design. Herein, the effect of rare-earth ions on the fluorescence of l-methionine-stabilized gold nanoclusters (Met-AuNCs) was investigated. It was found that europium (Eu3+) can significantly suppress the emission of Met-AuNCs, while other rare-earth ions showed a negligible impact. The mechanism on the observed fluorescence quenching of Met-AuNCs triggered by Eu3+was systematically explored, with results revealing the dominant role of photoinduced electron transfer (PET). Eu3+can bind to the surface of Met-AuNCs by the coordination effect and accepts the electron from the excited Met-AuNCs, which results in Met-AuNC fluorescence suppression. After introducing dipicolinic acid (DPA), an excellent biomarker for spore-forming pathogens, Eu3+was removed from the surface of Met-AuNCs owing to the higher binding affinity between Eu3+and DPA. Consequently, an immediate fluorescence recovery occurred when DPA was present in the system. Based on the Met-AuNC/Eu3+ensemble, we then established a simple and sensitive fluorescence strategy for turn-on determination of biomarker DPA, with a linear range of 0.2–4 μM and a low limit of detection of 110 nM. The feasibility of the proposed method was further validated by the quantitative detection of DPA in the soil samples. We believe that this study would significantly facilitate the construction of metal-ion-mediated PET sensors for the measurement of various interested analytes by applying fluorescent AuNCs as detection probes.

Leaf color has been considered an important agronomic trait in rice (Oryza sativaL.) for a long time. The changes in leaf color affect the yield of rice. In this study, a green-revertible albino(graS) mutant was isolated from a 60Co-gamma-irradiated mutant pool of indicacultivar Guangzhan 63-4S. The fine mapping indicated that graSmutant was mapped to chromosome 1, and was located in a confined region between markers ab134 and InDel 8 with genetic distances of 0.11 and 0.06 cM, respectively. Based on the annotation results, four open reading frames (ORFs) were predicted in this region. Sequence analysis revealed that LOC_Os01g55974had a 2-bp nucleotide insertion (AA) in the coding region that led to premature termination at the 324th base. Sequence analysis and expression analysis of related genes indicated that LOC_Os01g55974is the candidate gene of GraS.We studied the genome and protein sequences of LOC_Os01g55974, and the data showed that GraScontains a deoxycytidine deaminase domain, which was expressed ubiquitously in all tissues. Further investigation indicated that GraSplays an essential role in the regulation of chloroplast biosynthesis, photosynthetic capacity and yield. Moreover, leaf color mutant can be used as an effective marker for the purity of breeding and hybridization.

The current work presents the designed series of compositions within pseudocubic regions based on (1–x)La0.03Na0.91NbO3–xBi(Li0.5Nb0.5)O3ceramics abridged as (1–x)LNN–xBLN meant for energy storage applications. The addition of Bi(Li0.5Nb0.5)O3(BLN) considerably disrupted the ferroelectric order of the La0.03Na0.91NbO3(LNN) ceramics and favored the perfection of the energy storage density properties. Material properties like breakdown strength (BDS), charge–discharge efficiency (η), and dielectric loss of the system were enhanced via the incorporation of BLN into LNN. The external electric field supply into the system drastically enlarged the energy storage density, where the maximum recoverable energy density value of 2.02 J cm–3at 300 kV cm–1was achieved in 0.88LNN–0.12BLN ceramics. Besides this, the new system also demonstrates a strong ability to withstand stress (fatigue-free character) and sound temperature stability characteristics. The impressive storage density, temperature stability, cycle stability, and frequency stability credited to a steady relaxor pseudocubic phase covering a broad temperature range describes the newly designed system. The results demonstrate the potential for the (1–x)LNN–xBLN ceramics as the promising lead-free energy storage materials.

A comparison between poly(vinyl alcohol) (PVA)-formed (TYPE-I), Ba(OH)2/TiO2[Ba/Ti] suspension-formed (TYPE-II), and cold isostatic pressed (CIP) pellets (TYPE-II+CIP) of 0.9BaTi1–xCaxO3-x–0.1BiAlO3(x= 0.005–0.03) was investigated. The nominal composition of BiAlO3was kept constant at a limit of 0.1 in order to resolve the effect of Ca-substitution to the Ti-site. The experimental interpretations of the processing structure–property relationship explicitly support the effectiveness of Ba(OH)2/TiO2suspension, as expounded by efficient characterizations with regard to the thermal properties, phase structures, density developments, dielectric properties, microstructure progressions, and impedance analysis response to temperature. Thus, we present XRD analyses and SEM and TEM images that relate the basic underlying dielectric-temperature stability mechanism to the evolutionary dynamics of B-site substitution and core–shell morphology in a densified microstructure (TYPE-II: 5.723–5.919 g/cm3, TYPE-II+CIP: 5.784–5.938 g/cm3) of a submicrometer grain size (TYPE-II: 0.32–0.8 μm, TYPE-II+CIP: 0.23–0.71 μm). Apart from enhancing low-temperature sintering, this is the first time a Ba(OH)2/TiO2precursor suspension has been incorporated as a unique mechanism to effect a wide-range X8R dielectric material.

Protein-supported nanoparticles have a great significance in scientific and nanotechnology research because of their “green” process, low cost-in-use, good biocompatibility, and some interesting properties. Ruthenium oxide nanoparticles (RuO2NPs) have been considered to be an important member in nanotechnology research. However, the biosynthetic approach of RuO2NPs is relatively few compared to those of other nanoparticles. To address this challenge, this work presented a new way for RuO2NP synthesis (BSA-RuO2NPs) supported by bovine serum albumin (BSA). BSA-RuO2NPs are confirmed to exert peroxidase-like activity, electrocatalytic activity, in vitro salt resistance (2 M NaCl), and biocompatibility. Results indicate that BSA-RuO2NPs have higher affinity binding for 3,3′,5,5′-tetramethylbenzidine or H2O2than bare RuO2NPs. Moreover, BSA turns out to be a crucial factor in promoting the stability of RuO2NPs. Taking the advantages of these improved properties, we established colorimetric (linear range from 2 to 800 μM, a limit of detection of 1.8 μM) and electrochemical (linear range from 0.4 to 3850 μM, a limit of detection of 0.18 μM) biosensors for monitoring in situ H2O2secretion from living MCF-7 cells. Herein, this work offers a new biosynthesis strategy to obtain BSA-RuO2NPs and sheds light on the sensitive biosensors to monitor the H2O2secreted from living cells for promising applications in the fields of nanotechnology, biology, biosensors, and medicine.

Donor–linker–acceptor (D-L-A)-based photoinduced electron transfer (PET) has been frequently used for the construction of versatile fluorescent chemo/biosensors. However, sophisticated and tedious processes are generally required for the synthesis of these probes, which leads to poor design flexibility. In this work, by exploiting a Schiff base as a linker unit, a covalently bound D-L-A system was established and subsequently utilized for the development of a PET sensor. Cysteamine (Cys) and N-acetyl-l-cysteine (NAC) costabilized gold nanoclusters (Cys/NAC-AuNCs) were synthesized and adopted as an electron acceptor, and pyridoxal phosphate (PLP) was selected as an electron donor. PLP can form a Schiff base (an aldimine) with the primary amino group of Cys/NAC-AuNC through its aldehyde group and thereby suppresses the fluorescence of Cys/NAC-AuNC. The Rehm–Weller formula results and a HOMO–LUMO orbital study revealed that a reductive PET mechanism is responsible for the observed fluorescence quenching. Since the pyridoxal (PL) produced by the acid phosphatase (ACP)-catalyzed cleavage of PLP has a weak interaction with Cys/NAC-AuNC, a novel turn-on fluorescent method for selective detection of ACP was successfully realized. To the best of our knowledge, this is the first example of the development of a covalently bound D-L-A system for fluorescent PET sensing of enzyme activity based on AuNC nanoprobes using a Schiff base.

A visual assay for the detection of heparinase was developed on the basis of a ternary system of Hg2+–heparin–osmium nanoparticles (OsNPs). First, heparin-capped OsNPs (heparin–OsNPs) were synthesized by a facile reduction method using heparin as the protecting/stabilizing agent. The oxidase-like activity of heparin–OsNPs, however, turned out to be low, which somewhat limits their application. We discovered that Hg2+can significantly/specifically boost the oxidase-like activity of heparin–OsNPs via electrostatic interaction. The oxidase-like activity of heparin–OsNPs toward the oxidation of the substrate, 3,3′,5,5′-tetramethylbenzidine, by dissolved O2was found to increase by 76-fold in the presence of Hg2+. More significantly, heparin in heparin–OsNPs could be specifically hydrolyzed into small fragments in the presence of heparinase, which resulted in the weakening of the oxidase-like activity of Hg2+/heparin–OsNPs. On the basis of these findings, a linear response of the sensor for heparinase was obtained in the range 20–1000 μg/L with a low detection limit (15 μg/L), which is comparable to those of other reported sensors. Further, the colorimetric sensor was employed for the detection of heparinase in human serum samples with satisfactory results. We speculate that combining such surface modification of the osmium nanozyme with a sensing element could be an interesting direction for promoting nanozyme research in medical diagnosis.

High-performance piezoelectric materials are pivotal to many electromechanical applications including piezoelectric actuators, sensors, and transducers. However, the general approach to achieve high piezoelectric properties by establishing morphotropic phase boundary (MPB) has limitation due to the weak anisotropy of the Gibbs free energy profile at the MPB region. Here, aliovalent Sm3+-doped 0.4Pb(Mg1/3Nb2/3)O3-(0.6–x)PbZrO3-xPbTiO3piezoelectric ceramics were fabricated by a solid-state method, where the optimized piezoelectric coefficient d33= 910 pC/N, dielectric constant εr= 4090, and Curie temperature TC= 184 °C were obtained at x= 0.352, being attributed to the synergistic contributions from the MPB and enhanced local structural heterogeneity. Rayleigh analysis was adopted to study the intrinsic and extrinsic contributions in Sm-doped PMN-PZ-PT ceramics, where the extrinsic contribution was found to be on the order of 25–67% at 4 kV/cm. Of particular significance is that a large signal d33* = 820 pm/V (at 20 kV/cm) with a minimal strain variation of 5% was achieved for a composition of x= 0.372 over the temperature range of 20–160 °C, being superior to those previously reported piezoelectric ceramic materials. This work offers a good paradigm to simultaneously achieve high piezoelectric properties with good temperature stability in ferroelectric ceramics, which have great potential for piezoelectric application at elevated temperatures.

Dielectric ceramics with high energy storage density and energy efficiency play an important role in high power energy storage applications. In this work, lead free relaxor ferroelectric ceramics in (1-x)Bi0.51Na0.47TiO3- xBa(Zr0.3Ti0.7)O3(BNT-BZT100x: x = 0.20, 0.30, 0.40 and 0.50) system are fabricated by conventional solid-state sintering method. The BNT-BZT100xceramics are sintered dense with minimal pores, exhibiting pseudocubic symmetry and strong relaxor characteristic. A high energy storage density of 3.1 J/cm3and high energy efficiency of 91% are simultaneously achieved in BNT-BZT40 ceramic with 0.1 mm in thickness, at the applied electric field of 280 kV/cm. The temperature stability of the energy density is studied over temperature range of 20–160 °C, showing minimal variation below 1.5%, together with the excellent cycling reliability (the variations of both energy density and efficiency are below 3% up to 106cycles), making BNT-BZT40 ceramic promising candidate for high-temperature dielectric and energy storage applications.

High dielectric nonlinearity is a basic requirement for various microwave devices, such as tunable oscillators, phase shifters, varactors, etc. This study focuses on the dielectric nonlinearity of Sr(Nb0.5Al0.5)xTi1–xO3paraelectric ceramics, a giant permittivity and low dielectric loss system. The anomalous dielectric nonlinearity (permittivity increases as the DC bias electric field intensifies) was observed under a low electric field (∼5 kV/cm) for the first time, which cannot be explained by previously proposed theories that were applied for ferroelectrics and relaxor ferroelectrics. The abnormal phenomenon occurred at the same temperature region as the polarization and hopping conduction between Ti3+and Ti4+. Furthermore, the Ti3+concentration decreased and the size of the defect dipole increased after the sample was polarized. Compared with being sintered in air, the samples sintered in nitrogen feature a high Ti3+concentration, which reduce the starting temperature of anomalous dielectric nonlinearity. It can be proposed that the anomalous dielectric nonlinearity was ascribed to the electronic relaxation polarization and/or produced large defect dipoles of Ti3+under a low electric field. These fundamental understandings will provide an innovative way to adjust the dielectric nonlinearity of materials.

Although it has been demonstrated that rare-earth elements (REEs) disturb and alter the catalytic activity of numerous natural enzymes, their effects on nanomaterial-based artificial enzymes (nanozymes) have been seldom explored. In this work, the influence of REEs on the peroxidase-like activity of bare gold nanoparticles (GNPs) is investigated for the first time, and a new type of Ce3+-activated peroxidase mimetic activity of GNPs is obtained. The introduced Ce3+can be bound to the bare GNP surface rapidly through electrostatic attraction, after which it donates its electron to the bare GNP. As H2O2is a good electron scavenger, more •OH radicals are generated on the surfaces of the bare GNPs, which can considerably enhance TMB oxidation. Due to its redox cycling ability, the activation effect of Ce3+is proved to be more efficient in comparison to those of the other reported metal ion activators (e.g., Bi3+, Hg2+, and Pb2+). In addition, it is determined that Ce3+should directly contact with the gold core to trigger its activation effect. When the surface states of the bare GNPs are altered, the Ce3+-stimulated effect is strongly inhibited. Furthermore, a novel colorimetric method for Ce3+is developed, on the basis of its enhancing effect on the peroxidase mimetic activity of bare GNPs. The sensitivity of this newly developed method for Ce3+is excellent with a limit of detection as low as 2.2 nM. This study not only provides an effective GNP-based peroxidase mimic but also contributes in realizing new applications for nanozymes.

A new conidial fungus,Nakataea multiseptatasp. nov. was collected from dead branches of forests in southern China. It is described, illustrated and compared with closely related taxa.Nakataea multiseptatais characterized by fusiform to obclavate and 5-septate conidia with an appendage at each end. A key to the accepted species ofNakataeais provided.

Previous studies have reported that lipoxin A4 (LXA4) and the angiotensin I-converting enzyme 2 (ACE2), angiotensin-(1-7) [Ang-(1-7)], and its receptor Mas [ACE2-Ang-(1-7)-Mas] axis play important protective roles in acute lung injury (ALI). However, there is still no direct evidence of LXA4-mediated protection via the ACE2-Ang-(1-7)-Mas axis during ALI. This work was performed using an LPS-induced ALI mouse model and the data indicated the following. First, the animal model was established successfully and LXA4 ameliorated LPS-induced ALI. Second, LXA4 could increase the concentration and activity of ACE2 and the levels of Ang-(1-7) and Mas markedly. Third, LXA4 decreased the levels of TNF-α, IL-1β, and reactive oxygen species while increasing IL-10 levels. Fourth, LXA4 inhibited the activation of the NF-κB signal pathway and repressed the degradation of inhibitor of NF-κB, the phosphorylation of NF-κB, and the translocation of NF-κB. Finally, and more importantly, BOC-2 (LXA4 receptor inhibitor), MLN-4760 (ACE2 inhibitor), and A779 (Mas receptor antagonist) were found to reverse all of the effects of LXA4. Our data provide evidence that LXA4 protects the lung from ALI through regulation of the ACE2-Ang-(1-7)-Mas axis.

As the number of anatomic total shoulder arthroplasties performed on younger patients continues to grow, return to work after surgery becomes increasingly important. The purpose of this study was to evaluate the ability of anatomic total shoulder arthroplasty to return patients 55 years or younger to work postoperatively. A retrospective review was performed of consecutive anatomic total shoulder arthroplasty patients. Inclusion criteria were age 55 years or younger at surgery, greater than 2 years of follow-up, and employment within 3 years of surgery. Employment was stratified by intensity of work (sedentary, light, moderate, or heavy). Return to work status and time out of work were also evaluated. Fifty-two patients worked before surgery. Average age was 48.4 years, with average follow-up of 5.4 years. Seventy-three percent were male, and average body mass index was 28.0 kg/mAs the number of anatomic total shoulder arthroplasties performed on younger patients continues to grow, return to work after surgery becomes increasingly important. The purpose of this study was to evaluate the ability of anatomic total shoulder arthroplasty to return patients 55 years or younger to work postoperatively. A retrospective review was performed of consecutive anatomic total shoulder arthroplasty patients. Inclusion criteria were age 55 years or younger at surgery, greater than 2 years of follow-up, and employment within 3 years of surgery. Employment was stratified by intensity of work (sedentary, light, moderate, or heavy). Return to work status and time out of work were also evaluated. Fifty-two patients worked before surgery. Average age was 48.4 years, with average follow-up of 5.4 years. Seventy-three percent were male, and average body mass index was 28.0 kg/m2. Average visual analog scale score improved from 5.5 to 0.9 (P<.0001) and American Shoulder and Elbow Society score improved from 39.9 to 88.3 (P<.0001). Forty-eight (92%) of 52 returned to work postoperatively after an average of 2.1 months. When stratified by intensity, all patients with sedentary, light, or moderate work returned, whereas 64% returned to heavy work (P<.01). Eighty-seven percent were satisfied to very satisfied after surgery. In summary, most patients (92%) who undergo anatomic total shoulder arthroplasty at 55 years or younger return to work, on average, 2.1 months after surgery. [Orthopedics.2018; 41(3):e310–e315.]

This work attempted to elucidate the corrosion inhibition mechanism of a supramolecular complex formed between β-cyclodextrin (β-CD) and octadecylamine (ODA) for mild steel in the condensate water. Molecular mechanics simulation was applied to determine the energy favored configuration of the complex and the possible orientation of ODA inside the β-CD cavity. Based on the results of gravimetric measurements, thermodynamics parameters for the adsorption process were calculated through Arrhenius and transition state equations. Scanning electron microscopy and X-ray photo electron spectroscopy were used for surface characterization. Density functional theory calculations (Mulliken charges and molecular electrostatic potential plot) were performed to clarify the adsorption mechanism of β-CD/ODA complex on the steel surface. It was found that four possible configurations of β-CD/ODA complex might be concurrent in the supramolecular system with the stable state in the aqueous solution. ODA molecules could break away from the β-CD cavity and chemically adsorbed on the metal surface, which obeyed the Langmuir adsorption isotherm. The inherent molecular electrostatic properties resulted in the tilted adsorption of ODA.

The development of simple yet powerful methods for monitoring enzyme activity is of great significance. Herein, a facile, convenient, cost-effective, and continuous fluorescent method for the detection of arginase and its inhibitor has been reported based on a host–guest interaction-controlled and enzymatic hydrolysis-controlled luminescent nanoswitch. The fluorescence intensity of 6-aza-2-thiothymine-stabilized gold nanoparticle (ATT-AuNP) is enhanced by l-arginine, owing to the formation of a supramolecular host–guest assembly between the guanidine group of l-arginine and ATT molecules capped on the AuNP surface. However, hydrolysis of l-arginine, catalyzed by arginase, leads to a decrease in the fluorescence intensity of l-arginine/ATT-AuNPs hybrids. Upon incorporation of the arginase inhibitor l-norvaline, the fluorescence of the ATT-AuNP-based detecting system is restored. The linear range of arginase activity determination is from 0.0625 to 1.15 U/mL and the limit of detection is 0.056 U/mL. The half-maximal inhibition value IC50of l-norvaline is determined to be 5.6 mM. The practicability of this luminescent nanoswitch is validated by assaying the arginase activity in rat liver and monitoring the response of rat liver arginase to pharmacological agent. Compared to the existing fluorescent method of arginase activity assay, the approach demonstrated here does not involve any complicated technical manipulation, thereby greatly simplifying the detection steps. We propose that this AuNP-based luminescent nanoswitch would find wide applications in the field of life sciences and medicine.