Molecular basis of methyl-salicylate-mediated plant airborne defence.

Aphids transmit viruses and are destructive crop pests1. Plants that have been attacked by aphids release volatile compounds to elicit airborne defence (AD) in neighbouring plants2-5. However, the mechanism underlying AD is unclear. Here we reveal that methyl-salicylate (MeSA), salicylic acid-binding protein-2 (SABP2), the transcription factor NAC2 and salicylic acid-carboxylmethyltransferase-1 (SAMT1) form a signalling circuit to mediate AD against aphids and viruses. Airborne MeSA is perceived and converted into salicylic acid by SABP2 in neighbouring plants. Salicylic acid then causes a signal transduction cascade to activate the NAC2-SAMT1 module for MeSA biosynthesis to induce plant anti-aphid immunity and reduce virus transmission. To counteract this, some aphid-transmitted viruses encode helicase-containing proteins to suppress AD by interacting with NAC2 to subcellularly relocalize and destabilize NAC2. As a consequence, plants become less repellent to aphids, and more suitable for aphid survival, infestation and viral transmission. Our findings uncover the mechanistic basis of AD and an aphid-virus co-evolutionary mutualism, demonstrating AD as a potential bioinspired strategy to control aphids and viruses.

H2O2 negatively regulates aluminum resistance via oxidation and degradation of the transcription factor STOP1.

Aluminum (Al) stress triggers the accumulation of hydrogen peroxide (H2O2) in roots. However, whether H2O2 plays a regulatory role in aluminum resistance remains unclear. In this study, we show that H2O2 plays a crucial role in regulation of Al resistance, which is modulated by the mitochondrion-localized pentatricopeptide repeat protein REGULATION OF ALMT1 EXPRESSION 6 (RAE6). Mutation in RAE6 impairs the activity of complex I of the mitochondrial electron transport chain, resulting in the accumulation of H2O2 and increased sensitivity to Al. Our results suggest that higher H2O2 concentrations promote the oxidation of SENSITIVE TO PROTON RHIZOTOXICITY 1 (STOP1), an essential transcription factor that promotes Al resistance, thereby promoting its degradation by enhancing the interaction between STOP1 and the F-box protein RAE1. Conversely, decreasing H2O2 levels or blocking the oxidation of STOP1 leads to greater STOP1 stability and increased Al resistance. Moreover, we show that the thioredoxin TRX1 interacts with STOP1 to catalyze its chemical reduction. Thus, our results highlight the importance of H2O2 in Al resistance and regulation of STOP1 stability in Arabidopsis (Arabidopsis thaliana).

USP8 promotes cancer progression and extracellular vesicle-mediated CD8+ T cell exhaustion by deubiquitinating the TGF-ß receptor TßRII.

TGF-ß signaling is a key player in tumor progression and immune evasion, and is associated with poor response to cancer immunotherapies. Here, we identified ubiquitin-specific peptidase 8 (USP8) as a metastasis enhancer and a highly active deubiquitinase in aggressive breast tumors. USP8 acts both as a cancer stemness-promoting factor and an activator of the TGF-ß/SMAD signaling pathway. USP8 directly deubiquitinates and stabilizes the type II TGF-ß receptor TßRII, leading to its increased expression in the plasma membrane and in tumor-derived extracellular vesicles (TEVs). Increased USP8 activity was observed in patients resistant to neoadjuvant chemotherapies. USP8 promotes TGF-ß/SMAD-induced epithelial-mesenchymal transition (EMT), invasion, and metastasis in tumor cells. USP8 expression also enables TßRII+ circulating extracellular vesicles (crEVs) to induce T cell exhaustion and chemoimmunotherapy resistance. Pharmacological inhibition of USP8 antagonizes TGF-ß/SMAD signaling, and reduces TßRII stability and the number of TßRII+ crEVs to prevent CD8+ T cell exhaustion and to reactivate anti-tumor immunity. Our findings not only reveal a novel mechanism whereby USP8 regulates the cancer microenvironment but also demonstrate the therapeutic advantages of engineering USP8 inhibitors to simultaneously suppress metastasis and improve the efficacy of cancer immunotherapy.

SMYD2-Methylated PPARγ Facilitates Hypoxia-Induced Pulmonary Hypertension by Activating Mitophagy.

BACKGROUND: Hyperproliferation of pulmonary arterial smooth muscle cells (PASMCs) and consequent pulmonary vascular remodeling are the crucial pathological features of pulmonary hypertension (PH). Protein methylation has been shown to be critically involved in PASMC proliferation and PH, but the underlying mechanism remains largely unknown. METHODS: PH animal models were generated by treating mice/rats with chronic hypoxia for 4 weeks. SMYD2-vTg mice (vascular smooth muscle cell-specific suppressor of variegation, enhancer of zeste, trithorax and myeloid Nervy DEAF-1 (deformed epidural auto-regulatory factor-1) domain-containing protein 2 transgenic) or wild-type rats and mice treated with LLY-507 (3-cyano-5-{2-[4-[2-(3-methylindol-1-yl)ethyl]piperazin-1-yl]-phenyl}-N-[(3-pyrrolidin-1-yl)propyl]benzamide) were used to investigate the function of SMYD2 (suppressor of variegation, enhancer of zeste, trithorax and myeloid Nervy DEAF-1 domain-containing protein 2) on PH development in vivo. Primary cultured rat PASMCs with SMYD2 knockdown or overexpression were used to explore the effects of SMYD2 on proliferation and to decipher the underlying mechanism. RESULTS: We demonstrated that the expression of the lysine methyltransferase SMYD2 was upregulated in the smooth muscle cells of pulmonary arteries from patients with PH and hypoxia-exposed rats/mice and in the cytoplasm of hypoxia-induced rat PASMCs. More importantly, targeted inhibition of SMYD2 by LLY-507 significantly attenuated hypoxia-induced pulmonary vascular remodeling and PH development in both male and female rats in vivo and reduced rat PASMC hyperproliferation in vitro. In contrast, SMYD2-vTg mice exhibited more severe PH phenotypes and related pathological changes than nontransgenic mice after 4 weeks of chronic hypoxia treatment. Furthermore, SMYD2 overexpression promoted, while SMYD2 knockdown suppressed, the proliferation of rat PASMCs by affecting the cell cycle checkpoint between S and G2 phases. Mechanistically, we revealed that SMYD2 directly interacted with and monomethylated PPARγ (peroxisome proliferator-activated receptor gamma) to inhibit the nuclear translocation and transcriptional activity of PPARγ, which further promoted mitophagy to facilitate PASMC proliferation and PH development. Furthermore, rosiglitazone, a PPARγ agonist, largely abolished the detrimental effects of SMYD2 overexpression on PASMC proliferation and PH. CONCLUSIONS: Our results demonstrated that SMYD2 monomethylates nonhistone PPARγ and inhibits its nuclear translocation and activation to accelerate PASMC proliferation and PH by triggering mitophagy, indicating that targeting SMYD2 or activating PPARγ are potential strategies for the prevention of PH.

Cross-linker design determines microtubule network organization by opposing motors.

During cell division, cross-linking motors determine the architecture of the spindle, a dynamic microtubule network that segregates the chromosomes in eukaryotes. It is unclear how motors with opposite directionality coordinate to drive both contractile and extensile behaviors in the spindle. Particularly, the impact of different cross-linker designs on network self-organization is not understood, limiting our understanding of self-organizing structures in cells but also our ability to engineer new active materials. Here, we use experiment and theory to examine active microtubule networks driven by mixtures of motors with opposite directionality and different cross-linker design. We find that although the kinesin-14 HSET causes network contraction when dominant, it can also assist the opposing kinesin-5 KIF11 to generate extensile networks. This bifunctionality results from HSET's asymmetric design, distinct from symmetric KIF11. These findings expand the set of rules underlying patterning of active microtubule assemblies and allow a better understanding of motor cooperation in the spindle.

Dengue virus infection modifies mosquito blood-feeding behavior to increase transmission to the host.

Mosquito blood-feeding behavior is a key determinant of the epidemiology of dengue viruses (DENV), the most-prevalent mosquito-borne viruses. However, despite its importance, how DENV infection influences mosquito blood-feeding and, consequently, transmission remains unclear. Here, we developed a high-resolution, video-based assay to observe the blood-feeding behavior of Aedes aegypti mosquitoes on mice. We then applied multivariate analysis on the high-throughput, unbiased data generated from the assay to ordinate behavioral parameters into complex behaviors. We showed that DENV infection increases mosquito attraction to the host and hinders its biting efficiency, the latter resulting in the infected mosquitoes biting more to reach similar blood repletion as uninfected mosquitoes. To examine how increased biting influences DENV transmission to the host, we established an in vivo transmission model with immuno-competent mice and demonstrated that successive short probes result in multiple transmissions. Finally, to determine how DENV-induced alterations of host-seeking and biting behaviors influence dengue epidemiology, we integrated the behavioral data within a mathematical model. We calculated that the number of infected hosts per infected mosquito, as determined by the reproduction rate, tripled when mosquito behavior was influenced by DENV infection. Taken together, this multidisciplinary study details how DENV infection modulates mosquito blood-feeding behavior to increase vector capacity, proportionally aggravating DENV epidemiology. By elucidating the contribution of mosquito behavioral alterations on DENV transmission to the host, these results will inform epidemiological modeling to tailor improved interventions against dengue.

Myocardial reperfusion injury exacerbation due to ALDH2 deficiency is mediated by neutrophil extracellular traps and prevented by leukotriene C4 inhibition.

BACKGROUND AND AIMS: The Glu504Lys polymorphism in the aldehyde dehydrogenase 2 (ALDH2) gene is closely associated with myocardial ischaemia/reperfusion injury (I/RI). The effects of ALDH2 on neutrophil extracellular trap (NET) formation (i.e. NETosis) during I/RI remain unknown. This study aimed to investigate the role of ALDH2 in NETosis in the pathogenesis of myocardial I/RI. METHODS: The mouse model of myocardial I/RI was constructed on wild-type, ALDH2 knockout, peptidylarginine deiminase 4 (Pad4) knockout, and ALDH2/PAD4 double knockout mice. Overall, 308 ST-elevation myocardial infarction patients after primary percutaneous coronary intervention were enrolled in the study. RESULTS: Enhanced NETosis was observed in human neutrophils carrying the ALDH2 genetic mutation and ischaemic myocardium of ALDH2 knockout mice compared with controls. PAD4 knockout or treatment with NETosis-targeting drugs (GSK484, DNase1) substantially attenuated the extent of myocardial damage, particularly in ALDH2 knockout. Mechanistically, ALDH2 deficiency increased damage-associated molecular pattern release and susceptibility to NET-induced damage during myocardial I/RI. ALDH2 deficiency induced NOX2-dependent NETosis via upregulating the endoplasmic reticulum stress/microsomal glutathione S-transferase 2/leukotriene C4 (LTC4) pathway. The Food and Drug Administration-approved LTC4 receptor antagonist pranlukast ameliorated I/RI by inhibiting NETosis in both wild-type and ALDH2 knockout mice. Serum myeloperoxidase-DNA complex and LTC4 levels exhibited the predictive effect on adverse left ventricular remodelling at 6 months after primary percutaneous coronary intervention in ST-elevation myocardial infarction patients. CONCLUSIONS: ALDH2 deficiency exacerbates myocardial I/RI by promoting NETosis via the endoplasmic reticulum stress/microsomal glutathione S-transferase 2/LTC4/NOX2 pathway. This study hints at the role of NETosis in the pathogenesis of myocardial I/RI, and pranlukast might be a potential therapeutic option for attenuating I/RI, particularly in individuals with the ALDH2 mutation.

Toripalimab combined with definitive chemoradiotherapy for locally advanced cervical squamous cell carcinoma patients (TRACE): A single-arm, phase I/II trial.

PURPOSE: This phase I/II trial (ChiCTR2000032879) assessed the safety and efficacy of toripalimab combined with chemoradiotherapy for locally advanced cervical squamous cell carcinoma. METHODS AND MATERIALS: Twenty-two patients, regardless of their programmed death ligand-1 (PD-L1) status, received toripalimab combined with concurrent chemoradiotherapy (CCRT). CCRT included cisplatin (40 mg/m2, once weekly for 5 weeks), radiotherapy (45-50.4 Gy/25-28 Fx, 5 fractions weekly), followed by brachytherapy (24-30 Gy/3-5 Fx) and toripalimab (240 mg, intravenous) on days 1, 22 and 43 during CCRT. The primary endpoints were safety and 2-year progression-free survival (PFS). The secondary endpoints included 2-year local control (LC), local regional control and overall survival (OS). RESULTS: All patients successfully completed CCRT and toripalimab treatment. Grade III and higher adverse events (AEs) were observed in 11 patients (11/22, 50%), and no patient experienced grade V AEs. The objective response rate (ORR) was 100%. At the data cutoff (June 30, 2023), the median follow-up was 31.8 months (9.5 to 37.8 months). The 2-year PFS rate was 81.8%. The 2-year LC and local regional control rates were both 95.5%, and the 2-year OS rate was 90.9%. CONCLUSIONS: Toripalimab combined with CCRT achieved good tolerance and showed promising anti-tumor effects in patients with locally advanced cervical cancer.

Modulation of external and internal aluminum resistance by ALS3-dependent STAR1-mediated promotion of STOP1 degradation.

The ALMT1 transporter aids malate secretion, chelating Al3+ ions to form nontoxic Al-malate complexes, believed to exclude Al from the roots. However, the extent to which malate secreted by ALMT1 is solely used for the exclusion of Al3+ or can be reutilized by plant roots for internal Al tolerance remains uncertain. In our investigation, we explored the impact of malate secretion on both external and internal Al resistance in Arabidopsis thaliana. Additionally, we delved into the mechanism by which the tonoplast-localized bacterial-type ATP-binding cassette (ABC) transporter complex STAR1/ALS3 promotes the degradation of the Al resistance transcription factor STOP1 to regulate ALMT1 expression. Our study demonstrates that the level of secreted malate influences whether the Al-malate complex is excluded from the roots or transported into root cells. The nodulin 26-like intrinsic protein (NIP) subfamily members NIP1;1 and NIP1;2, located in the plasma membrane, coordinate with STAR1/ALS3 to facilitate Al-malate transport from root apoplasm to the symplasm and eventually to the vacuoles for the internal Al detoxification. ALS3-dependent STAR1 interacts with and promotes the degradation of STOP1, regulating malate exudation. Our findings demonstrate the dual roles of malate exudation in external Al exclusion and Al absorption for internal Al detoxification.

Visualizing features with wide-field volumetric OCT angiography.

Optical coherence tomography (OCT) and its extension OCT angiography (OCTA) have become essential clinical imaging modalities due to their ability to provide depth-resolved angiographic and tissue structural information non-invasively and at high resolution. Within a field of view, the anatomic detail available is sufficient to identify several structural and vascular pathologies that are clinically relevant for multiple prevalent blinding diseases, including age-related macular degeneration (AMD), diabetic retinopathy (DR), and vein occlusions. The main limitation in contemporary OCT devices is that this field of view is limited due to a fundamental trade-off between system resolution/sensitivity, sampling density, and imaging window dimensions. Here, we describe a swept-source OCT device that can capture up to a 12 × 23-mm field of view in a single shot and show that it can identify conventional pathologic features such as non-perfusion areas outside of conventional fields of view. We also show that our approach maintains sensitivity sufficient to visualize novel features, including choriocapillaris morphology beneath the macula and macrophage-like cells at the inner limiting membrane, both of which may have implications for disease.

Optimizing numerical k-sampling for swept-source optical coherence tomography angiography.

High-quality swept-source optical coherence tomography (SS-OCT) requires accurate k-sampling, which is equally vital for optical coherence tomography angiography (OCTA). Most SS-OCT systems are equipped with hardware-driven k-sampling. However, this conventional approach raises concerns over system cost, optical alignment, imaging depth, and stability in the clocking circuit. This work introduces an optimized numerical k-sampling method to replace the additional k-clock hardware. Using this method, we can realize high axial resolution (4.9-µm full-width-half-maximum, in air) and low roll-off (2.3 dB loss) over a 4-mm imaging depth. The high axial resolution and sensitivity achieved by this simple numerical method can reveal anatomic and microvascular structures with structural OCT and OCTA in both macular and deeper tissues, including the lamina cribrosa, suggesting its usefulness in imaging retinopathy and optic neuropathy.

The addition of pembrolizumab to neoadjuvant chemoradiotherapy did not increase the risk of developing postoperative anastomotic leakage for ESCC: an analysis from a prospective cohort.

BACKGROUND: To compare the difference of postoperative anastomotic leakage (AL) rate between neoadjuvant chemoradiotherapy (NCRT) with pembrolizumab and NCRT group, and investigate the risk factors of developing AL for locally advanced esophageal squamous cell cancer (ESCC). MATERIALS AND METHODS: The GF was contoured on the pretreatment planning computed tomography and dosimetric parameters were retrospectively calculated. Univariate and multivariate logistic regression analysis was performed to determine the independent risk predictors for the entire cohort. A nomogram risk prediction model for postoperative AL was established. RESULTS: A total of 160 ESCC patients were included for analysis. Of them, 112 were treated with NCRT with pembrolizumab and 44 patients with NCRT. Seventeen (10.6%) patients experienced postoperative AL with a rate of 10.7% (12/112) in NCRT with pembrolizumab and 11.4% (5/44) in NCRT group. For the entire cohort, mean, D50, Dmax, V5, V10 and V20 GF dose were statistically higher in those with AL (all p < 0.05). Multivariate logistic regression analysis indicated that tumor length (p = 0.012), volume of GF (p = 0.003) and mean dose of GF (p = 0.007) were independently predictors for postoperative AL. Using receiver operating characteristics analysis, the mean dose limit on the GF was defined as 14 Gy. CONCLUSION: Based on our prospective database, no significant difference of developing AL were observed between NCRT with pembrolizumab and NCRT group. We established an individualized nomograms based on mean GF dose combined with clinical indicators to predict AL in the early postoperative period.

Biosynthesis of nonnutritive monosaccharide d-allulose by metabolically engineered Escherichia coli from nutritive disaccharide sucrose.

Sucrose is a commonly utilized nutritive sweetener in food and beverages due to its abundance in nature and low production costs. However, excessive intake of sucrose increases the risk of metabolic disorders, including diabetes and obesity. Therefore, there is a growing demand for the development of nonnutritive sweeteners with almost no calories. d-Allulose is an ultra-low-calorie, rare six-carbon monosaccharide with high sweetness, making it an ideal alternative to sucrose. In this study, we developed a cell factory for d-allulose production from sucrose using Escherichia coli JM109 (DE3) as a chassis host. The genes cscA, cscB, cscK, alsE, and a6PP were co-expressed for the construction of the synthesis pathway. Then, the introduction of ptsG-F and knockout of ptsG, fruA, ptsI, and ptsH to reprogram sugar transport pathways resulted in an improvement in substrate utilization. Next, the carbon fluxes of the Embden-Meyerhof-Parnas and the pentose phosphate pathways were regulated by the inactivation of pfkA and zwf, achieving an increase in d-allulose titer and yield of 154.2% and 161.1%, respectively. Finally, scaled-up fermentation was performed in a 5 L fermenter. The titer of d-allulose reached 11.15 g/L, with a yield of 0.208 g/g on sucrose.

Dysregulation of AMPK-mTOR signaling leads to comorbid anxiety in Dip2a KO mice.

Autism is often comorbid with other psychiatric disorders. We have previously shown that Dip2a knockout (KO) induces autism-like behaviors in mice. However, the role of Dip2a in other psychiatric disorders remains unclear. In this paper, we revealed that Dip2a KO mice had comorbid anxiety. Dip2a KO led to a reduction in the dendritic length of cortical and hippocampal excitatory neurons. Molecular mechanism studies suggested that AMPK was overactivated and suppressed the mTOR cascade, contributing to defects in dendritic morphology. Deletion of Dip2a in adult-born hippocampal neurons (Dip2a conditional knockout (cKO)) increased susceptibility to anxiety upon acute stress exposure. Application of (2R,6R)-hydroxynorketamine (HNK), an inhibitor of mTOR, rescued anxiety-like behaviors in Dip2a KO and Dip2a cKO mice. In addition, 6 weeks of high-fat diet intake alleviated AMPK-mTOR signaling and attenuated the severity of anxiety in both Dip2a KO mice and Dip2a cKO mice. Taken together, these results reveal an unrecognized function of DIP2A in anxiety pathophysiology via regulation of AMPK-mTOR signaling.

Immunogenic cell death-related genes predict prognosis and response to immunotherapy in lung squamous cell carcinoma.

Lung squamous cell carcinoma (LUSC) is a malignancy with limited therapeutic options. Immunogenic cell death (ICD) has the potential to enhance the efficacy of cancer therapy by triggering immune responses. We aimed to explore the potential of ICD-based classification in predicting prognosis and response to immunotherapy for LUSC. RNA-seq information and clinical data of LUSC patients were obtained from The Cancer Genome Atlas (TCGA) dataset. ICD-related gene expressions in LUSC samples were analyzed by consensus clustering. Subsequently, differentially expressed genes (DEGs) between different ICD-related subsets were analyzed. Tumor mutation burden, immune cell infiltration, and survival analyses were conducted between different ICD subsets. Finally, an ICD-related risk signature was constructed and evaluated in LUSC patients, and the immunotherapy responses based on the gene expressions were also forecasted. ICD-high and ICD-low groups were defined, and 1466 DEGs were identified between the two subtypes. These DEGs were mainly enriched in collagen-containing extracellular matrix, cytokine-cytokine receptor interaction, the PI3K-Akt signaling pathway, and neuroactive ligand-receptor interaction. Furthermore, the ICD-low group exhibited a favorable prognosis, enhanced TTN and MUC16 mutation frequencies, increased infiltrating immune cells, and downregulated immune checkpoint expressions. Furthermore, we demonstrated that an ICD-related model (based on CD4, NLRP3, NT5E, and TLR4 genes) could forecast the prognosis of LUSC, and ICD risk scores were lower in the responder group. In summary, the predicted values of ICD-related genes (CD4, NLRP3, NT5E, and TLR4) for the prognosis and response to immunotherapy in LUSC were verified in the study, which benefits immunotherapy-based interventions for LUSC patients.

Customizing carrier screening in the Chinese population: Insights from a 334-gene panel.

OBJECTIVE: This study aimed to evaluate the yield and applicability of expanded carrier screening and propose carrier rate screening thresholds suitable for the Chinese population by comparing the current screening panel with the American College of Medical Genetics and Genomics recommended panel of 113 genes. METHODS: Using targeted next-generation sequencing, a customized panel with 334 genes was performed on 2168 individuals without clinical phenotypes for expanded carrier screening purpose. Variant interpretation followed the American College of Medical Genetics and Genomics guidelines. Carrier rates were calculated for each identified variant and each gene. At-risk couple rates were also assessed. The yield of expanded carrier screening was evaluated through calculating cumulative carrier rate. RESULTS: Overall, 65.87% of the individuals were found to be carriers of at least 1 disease causing variants. The overall at-risk couple rate was 11.76%, of which the GJB2:c.109G > A related at-risk couple rate was 5.78%. The cumulative carrier rate of 334-panel was 65.53%. When screened genes with gene carrier rate ≥1/1000, the expanded carrier screening can cover over 90% of the cumulative carrier rate and at-risk couples. A total of 86 genes overlapped with American College of Medical Genetics and Genomics Tier-3 genes and were attributed to the cumulative carrier rate of 47.33%. CONCLUSION: Expanded carrier screening using the 334-gene panel showed high screening efficiency. A threshold of gene carrier rate ≥1/1000 is recommended for selecting carrier screening genes in the Chinese Han population. This study highlights the importance of customizing screening panels based on the ACMG Tier-3 genes in conjunction with population-specific carrier frequencies to improve the accuracy and effectiveness of expanded carrier screening.

Lifetime mapping using femtosecond time-resolved photoemission electron microscopy.

Time-resolved photoemission electron microscopy (PEEM) has established itself as a versatile experimental technique to unravel the ultrafast electron dynamics of materials with nanometer-scale resolution. However, the approach of performing PEEM-based, pixel-by-pixel lifetime mapping has not been reported thus far. Herein, we describe in detail the data pre-processing procedure and an algorithm to perform time-trace fittings of each pixel. We impose an energy cutoff for each pixel prior to spectral integration to enhance the robustness of our approach. With the energy cutoff, the energy-integrated time traces show improved statistics and lower fitting errors, thus resulting in a more accurate determination of the fit parameters, e.g., decay time constants. Our work allows us to reliably construct PEEM-based lifetime maps, which potentially shed light on the effects of local microenvironment on the ultrafast processes of the material and allow spatial distributions of lifetimes to be correlated with observables obtained from complementary microscopic techniques, hence enabling a more comprehensive characterization of the material.

Deltoid tuberosity index for proximal humerus fracture: reliability and a predictor of systemic osteoporosis in an Asian population.

HYPOTHESIS AND BACKGROUND: Fragility fracture of the proximal humerus is a common occurrence. Current literature suggests that poor local bone density is a significant predictor of surgical fixation failure. The deltoid tuberosity index (DTI) is a simple radiographic tool that strongly correlates with local humeral bone mineral density (BMD), aiding surgical planning to consider adjuncts or arthroplasty. However, there is a lack of data in the reliability of assessment of DTI, as well as its correlation to systemic osteoporosis. Our study investigates the reliability of DTI as a predictor of systemic osteoporosis. METHODS: A retrospective cohort of patients with proximal humeral fracture (PHF) treated at a trauma center in Singapore from August 2017 to July 2018 were recruited. Four raters at different levels of varying clinical seniority measured DTI using shoulder radiographs. The dual-energy x-ray absorptiometry (DEXA) BMD scan of the hip and lumbar spine was used to diagnose osteoporosis. Area under the receiver operating characteristic curve analysis was calculated to study the diagnostic utility of DTI for predicting the risk of osteoporosis. RESULTS: Our study sample had 87 patients comprising 18 men and 69 women, mainly of Chinese ethnicity (84%), and with a mean age of 69.7 years (standard deviation 9.52, range 39-92). For assessment of DTI, there was good intrarater reliability among 4 raters (correlation coefficient range 0.805-0.843) and excellent interrater reliability between all raters (intraclass correlation coefficient 0.898, 95% confidence interval [CI] 0.784-0.950, P < .001). Based on the BMD, 55.2% (n = 48) had osteoporosis, with a T score <2.5. The highest correlation of DTI to BMD was with femoral neck density at 0.580. The DTI cutoff of 1.6 had the highest combined sensitivity and false positive rate, with areas under the curve of 0.682 (95% CI 0.564-0.799) for the overall population and 0.706 (95% CI 0.569-0.842) for patients aged <75 years. CONCLUSION: The DTI is a simple and reliable tool and has a strong applicability in clinical practice to enhance preoperative planning in the surgical fixation of PHF. DTI with a cutoff of 1.6 may help prompt clinicians to initiate workup and thus manage underlying osteoporosis.

Non-linear associations between night shifts and adverse events in nursing staff: a restricted cubic spline analysis.

INTRODUCTION: Existing studies suggest that the number of night shifts may impact the occurrence of adverse events. However, while this relationship is well-documented, previous research has not thoroughly examined the non-linear associations between night shifts and adverse events among nursing staff, which remains a gap in our understanding. METHODS: Participants were 1,774 Chinese nurse staff. Psychosocial characteristics were screened by The Chinese version of the multidimensional scale of perceived social support (MSPSS) for social support, the 9-item Patient Health Questionnaire (PHQ-9) for depressive symptoms, the Generalized Anxiety Disorder-7 (GAD-7) for anxiety symptoms. Binary logistic regression and restricted cubic splines were applied to analyze the data. The statistical software used were R version 3.6.2 and SPSS version 22.0. RESULTS: Over the past year, 325 cases (18.3%) were classified as adverse events. Logistic regression unveiled that social support played a protective role against adverse events, with an OR of 0.991 (95% CI: 0.983, 0.999). Furthermore, night shifts continued to surface as a substantial risk factor for adverse events, with an OR to 1.300 (95% CI: 1.181, 1.431). The restricted cubic spline regression model highlights a nonlinear relationship between night shifts and adverse events (P for non-liner < 0.001). The probability of adverse events increases with the number of night shifts, but compared to individuals working 3-4 night shifts per month, those working 5-6 night shifts per month have a lower probability of adverse events. CONCLUSION: Our findings indicate a non-linear relationship between the frequency of night shifts and adverse events, suggesting a complex interplay of factors. This highlights the need for nursing practice and policy to consider the intricacies of night shift scheduling and explore more reasonable rostering strategies to mitigate the probability of adverse events.

Upcycling of Carbon Fiber/Thermoset Composites into High-Performance Elastomers and Repurposed Carbon Fibers.

Recycling of carbon fiber-reinforced polymer composites (CFRCs) based on thermosetting plastics is difficult. In the present study, high-performance CFRCs are fabricated through complexation of aromatic pinacol-cross-linked polyurethane (PU-AP) thermosets with carbon fiber (CF) cloths. PU-AP thermosets exhibit a breaking strength of 95.5 MPa and toughness of 473.6 MJ m-3 and contain abundant hydrogen-bonding groups, which can have strong adhesion with CFs. Because of the high interfacial adhesion between CF cloths and PU-AP thermosets and high toughness of PU-AP thermosets, CF/PU-AP composites possess a high tensile strength of >870 MPa. Upon heating in N,N-dimethylacetamide (DMAc) at 100 °C, the aromatic pinacols in the CF/PU-AP composites can be cleaved, generating non-destructive CF cloths and linear polymers that can be converted to high-performance elastomers. The elastomers are mechanically robust, healable, reprocessable, and damage-resistant with an extremely high tensile strength of 74.2 MPa and fracture energy of 149.6 kJ m-2. As a result, dissociation of CF/PU-AP composites enables the recovery of reusable CF cloths and high-performance elastomers, thus realizing the upcycling of CF/PU-AP composites.