Electrochemical synthesis of peptide aldehydes via C‒N bond cleavage of cyclic amines.

Peptide aldehydes are crucial biomolecules essential to various biological systems, driving a continuous demand for efficient synthesis methods. Herein, we develop a metal-free, facile, and biocompatible strategy for direct electrochemical synthesis of unnatural peptide aldehydes. This electro-oxidative approach enabled a step- and atom-economical ring-opening via C‒N bond cleavage, allowing for homoproline-specific peptide diversification and expansion of substrate scope to include amides, esters, and cyclic amines of various sizes. The remarkable efficacy of the electro-synthetic protocol set the stage for the efficient modification and assembly of linear and macrocyclic peptides using a concise synthetic sequence with racemization-free conditions. Moreover, the combination of experiments and density functional theory (DFT) calculations indicates that different N-acyl groups play a decisive role in the reaction activity.

The efficacy of nutritional screening indexes in predicting the incidence of osteosarcopenia and major osteoporotic fracture in the elderly.

INTRODUCTION: The effect of nutritional status on osteosarcopenia (OS) and major osteoporotic fracture (MOF) among the elderly is still unclear. So we aimed to compare the efficacy of the Mini-Nutrition Assessment-Short Form (MNA-sf), the Geriatric Nutritional Risk Index (GNRI) and Controlling Nutritional Status (CONUT) for predicting OS and MOF among the elderly. MATERIALS AND METHODS: A total of 409 participants were enrolled in this prospective study. Blood biochemical indexes, nutritional status, and bone- and muscle-related examinations were assessed at initial visit to the outpatient. Participants were divided into 4 groups: (1) control; (2) osteopenia/osteoporosis; (3) sarcopenia; (4) osteosarcopenia, and then followed for 5 years, recording the occurrence time of MOF. RESULTS: The frequency values of osteopenia/osteoporosis, sarcopenia, and OS, at baseline, were respectively 13.4, 16.1, and 12% among the study samples. Correlation analysis showed that nutritional status scores were associated with body mass index, handgrip strength, albumin, bone mineral density, and physical functions. According to multivariate models, poor nutritional status was significantly associated with a higher risk of OS and MOF (P < 0.05). Survival analysis showed that the MOF rate in malnutrition group was significantly higher than normal nutrition group (P < 0.05). The receiver operator characteristic curve shows that the value of MNA-sf to diagnose OS and MOF is greater (P < 0.05). CONCLUSION: The poor nutritional status was associated with a higher risk of both OS and MOF. MNA-sf showed a superior diagnostic power for OS and MOF among the elderly. Early nutrition assessments and interventions may be key strategies to prevent OS and fractures.

Network Pharmacology Combined with Molecular Docking Approach to Investigate the Mechanism of ChuShiWeiLing Decoction Against Perianal Eczema.

BACKGROUND: ChuShiWeiLing Decoction (CSWLD) is a famous classical Chinese prescription for the treatment of eczema with desirable effect in clinical practice. It has gradually exerted good curative effects on perianal eczema (PE) in recent years, but its specific mechanism is not elucidated yet. OBJECTIVE: This research explores the underlying pharmacological mechanism of CSWLD in addressing PE through network pharmacology combined with molecular docking strategy. METHODS: The key chemical compounds and potential target genes of CSWLD were screened by bioinformatics. The major targets of CSWLD were discovered using network modules. Functional annotation of Gene Ontology (GO) was undertaken, as well as pathway enrichment analysis using the Kyoto Encyclopedia of Genes and Genomes (KEGG). Molecular docking of core protein-ligand interactions was modeled using AutoDock software. Pymol software was used to perform a molecular dynamics simulation for the ideal core protein-ligand that was discovered by molecular docking. RESULTS: A total of 2,853 active compounds and 922 targets of CSWLD were collected. The target with a higher degree was identified through the PPI network, namely TNF, IL6, ALB, STAT3, EGFR, TLR4, CXCL8 and PTPRC. GO and KEGG analyses suggested that CSWLD treatment of PE mainly involves cellular activation, activation of leukocytes, and adhesion among leukocytes. The molecular docking results showed that wogonin, hederagenin and quercetin of CSWLD could bind to IL-6 and TNF, respectively. CONCLUSION: Our results indicated that the bioactives, potential targets, and molecular mechanism of CSWLD against PE.

Vitamin D delays intervertebral disc degeneration and improves bone quality in ovariectomized rats.

Known to be involved in bone-cartilage metabolism, Vitamin D (VD) may play a role in human's disc pathophysiology. Given that postmenopausal women are prone to suffer VD deficiency and intervertebral disc degeneration (IDD), this study is intended to investigate whether VD can delay IDD in ovariectomized rats by improving bone microstructure and antioxidant stress. Female Sprague-Dawley rats were randomly allocated into four groups: sham, oophorectomy (OVX)+VD deficiency (VDD), OVX, and OVX+VD supplementation (VDS). In vivo, after a 6-month intervention, imaging and pathology slice examinations showed that IDD induced by OVX was significantly alleviated in VDS and deteriorated by VDD. The expressions of aggrecan and Collagen II in intervertebral disc were reduced by OVX and VDD, and elevated by VDS. Compared with the OVX+VDD and OVX group vertebrae, OVX+VDS group vertebrae showed significantly improved endplate porosity and lumbar bone mineral density with increased percent bone volume and trabecular thickness. Furthermore, 1α,25(OH)2D3 restored the redox balance (total antioxidant capacity, ratio of oxidized glutathione/glutathione) in the disc. The cocultivation of 1α,25(OH)2D3 and nucleus pulposus cells (NPCs) was conducted to observe its potential ability to resist excessive oxidative stress damage induced by H2O2. In vitro experiments revealed that 1α,25(OH)2D3 reduced the senescence, apoptosis, and extracellular matrix degradation induced by H2O2 in NPCs. In conclusion, VDS exhibits protective effects in OVX-induced IDD, partly by regulating the redox balance and preserving the microstructure of endplate. This finding provides a new idea for the prevention and treatment of IDD.

The Effects of Abdominal Obesity and Sagittal Imbalance on Sacroiliac Joint Pain After Lumbar Fusion.

BACKGROUND: Postoperative sacroiliac joint pain (SIJP) is a common manifestation of failed back surgery syndrome after a posterior lumbar interbody fusion (PLIF). However, there is currently no consensus on the risk factors for SIJP after PLIF. OBJECTIVES: We explored the effects of abdominal obesity and sagittal imbalance on SIJP after PLIF. STUDY DESIGN: This is a prospective observational cohort study. SETTING: This study occurred at the Department of Spinal Surgery at a hospital affiliated with a medical university. METHODS: A total of 401 patients who underwent PLIF from June 2018 to June 2021 were enrolled in this study. 36 patients experienced postoperative SIJP. In contrast, a matched group comprised 72 non-SIJP patients. We used 1:2 propensity score matching to compare obesity features and sagittal spine parameters in the 2 groups. Inflammatory cytokines and visual analog scale (VAS) scores were measured in the SIJP group. RESULTS: A total of 36 patients (8.98%) experienced SIJP during the follow-up. Compared with the non-SIJP group, patients with postoperative SIJP had a higher body mass index (BMI), greater abdominal obesity, a higher incidence of pelvic incidence-lumbar lordosis greater than 10°, and a higher incidence of a sagittal vertical axis greater than 5 cm (P < 0.05). Receiver operating characteristic curve analysis showed that the area under the curve for waist circumference was greater than that for BMI (0.762 vs. 0.650, P = 0.049). Logistic regression analysis revealed that the risk factors for SIJP were abdominal obesity, a pelvic incidence-lumbar lordosis of greater than 10°, and a sagittal vertical axis greater than 5 cm (P < 0.05). In patients with SIJP, interleukin 6, tumor necrosis factor-α, and VAS scores were higher in the abdominal obesity group than in the non-abdominal obesity group (P < 0.05). LIMITATIONS: There was no uniform diagnosis of SIJP, so the incidence rate of SIJP might not be accurate. CONCLUSIONS: The significant predictors of SIJP were abdominal obesity and sagittal imbalance. Patients with abdominal obesity showed higher levels of inflammatory markers and pain intensity. More attention should be paid to body shape and the angle of correction of lumbar lordosis before lumbar surgery.

Acupuncture as a therapeutic intervention for post-COVID-19 vaccination urticaria: a systematic review and meta-analysis protocol.

INTRODUCTION: The COVID-19 pandemic persisted for over 3 years since its onset in December 2019, posing an ongoing global threat to human health. In the absence of specific antiviral medications for COVID-19, vaccination has emerged as a popular preventive measure adopted by the general public. However, an undesirable consequence of COVID-19 vaccination has been the frequent incidence of urticaria, a type of adverse skin manifestations. Despite the prevalence of this issue, there is currently a lack of clinical evidence exploring the potential utility of acupuncture as a therapeutic approach to managing urticaria arising after COVID-19 vaccination. To address this knowledge gap, this study aims to comprehensively evaluate the effectiveness and safety of acupuncture as a therapeutic intervention for treating urticaria in the general population following COVID-19 vaccination. METHODS AND ANALYSIS: The retrieval strategies employed in this study involve obtaining all relevant articles published from December 2019 to October 2023. These articles will be obtained from databases including PubMed, EMBASE, Cochrane Library, Web of Science, Chinese National Knowledge Infrastructure (CNKI), Chinese Biomedical Literature Database (SinoMed), VIP database and the WanFang database. Subsequently, the collected articles will undergo a thorough screening process based on predefined inclusion and exclusion criteria. Additionally, study quality will be evaluated using the Cochrane risk bias assessment tool. To conduct the meta-analysis, we will employ the Review Manager software (RevMan V.5.3). Finally, the study findings will be evaluated for their level of evidence. ETHICS AND DISSEMINATION: As this is a secondary review of published clinical data, this study does not involve direct contact with human subjects, and therefore, ethical approval and consent are not required. The findings of the study will be disseminated through a peer-reviewed journal, ensuring that the results undergo rigorous evaluation by experts in the field. PROSPERO REGISTRATION NUMBER: CRD42022377343.

A solution and practice for combining multi-source heterogeneous data to construct enterprise knowledge graph.

The knowledge graph is one of the essential infrastructures of artificial intelligence. It is a challenge for knowledge engineering to construct a high-quality domain knowledge graph for multi-source heterogeneous data. We propose a complete process framework for constructing a knowledge graph that combines structured data and unstructured data, which includes data processing, information extraction, knowledge fusion, data storage, and update strategies, aiming to improve the quality of the knowledge graph and extend its life cycle. Specifically, we take the construction process of an enterprise knowledge graph as an example and integrate enterprise register information, litigation-related information, and enterprise announcement information to enrich the enterprise knowledge graph. For the unstructured text, we improve existing model to extract triples and the F1-score of our model reached 72.77%. The number of nodes and edges in our constructed enterprise knowledge graph reaches 1,430,000 and 3,170,000, respectively. Furthermore, for each type of multi-source heterogeneous data, we apply corresponding methods and strategies for information extraction and data storage and carry out a detailed comparative analysis of graph databases. From the perspective of practical use, the informative enterprise knowledge graph and its timely update can serve many actual business needs. Our proposed enterprise knowledge graph has been deployed in HuaRong RongTong (Beijing) Technology Co., Ltd. and is used by the staff as a powerful tool for corporate due diligence. The key features are reported and analyzed in the case study. Overall, this paper provides an easy-to-follow solution and practice for domain knowledge graph construction, as well as demonstrating its application in corporate due diligence.

α-Ketoglutaric acid ameliorates intervertebral disk degeneration by blocking the IL-6/JAK2/STAT3 pathway.

Intervertebral disk degeneration (IVDD) is the major cause of low back pain. Alpha-ketoglutaric acid (α-KG), an important intermediate in energy metabolism, has various functions, including epigenetic regulation, maintenance of redox homeostasis, and antiaging, but whether it can ameliorate IVDD has not been reported. Here, we examined the impacts of long-term administration of α-KG on aging-associated IVDD in adult rats. In vivo and in vitro experiments showed that α-KG supplementation effectively ameliorated IVDD in rats and the senescence of nucleus pulposus cells (NPCs). α-KG supplementation significantly attenuated senescence, apoptosis, and matrix metalloproteinase-13 (MMP-13) protein expression, and it increased the synthesis of aggrecan and collagen II in IL-1ß-treated NPCs. In addition, α-KG supplementation reduced the levels of IL-6, phosphorylated JAK2 and STAT3, and the nuclear translocation of p-STAT3 in IL-1ß-induced degenerating NPCs. The effects of α-KG were enhanced by AG490 in NPCs. The underlying mechanism may involve the inhibition of JAK2/STAT3 phosphorylation and the reduction of IL-6 expression. Our findings may help in the development of new therapeutic strategies for IVDD.NEW & NOTEWORTHY Alpha-ketoglutaric acid (α-KG) exerted its protective effect on nucleus pulposus cells' (NPCs) degeneration by inhibiting the senescence-associated secretory phenotype and extracellular matrix degradation. The possible mechanism may be associated with negatively regulating the JAK2/STAT3 phosphorylation and the decreased IL-6 expression, which could be explained by a blockage of the positive feedback control loop between IL-6 and JAK2/STAT3 pathway.

Dual-ring parity-time symmetric brillouin fiber laser with an unbalanced polarization Mach-Zehnder interferometer.

A dual-ring parity-time (PT) symmetric Brillouin fiber laser (BFL) with an unbalanced polarization Mach-Zehnder interferometer (UP-MZI) is proposed and experimentally investigated. An UP-MZI consisting of optical coupler, polarization beam combiner (PBC) and two asymmetric length arms with 10 km and 100 m single-mode fiber, is used to achieve Vernier effect and PT symmetry. Due to the orthogonally polarized lights created in the PBC, the dual-ring PT symmetry BFL with an UP-MZI implements two unbalanced length feedback rings that are connected to one another, one long length ring with a Brillouin gain and the other short length ring with a loss of the same magnitude, to break a PT symmetric and maintain the Vernier effect. By contrast with existing PT symmetry BFL studies, this design does not require same lengths of the gain and loss loops, but can manipulate freely PT symmetry status in accordance with a rational scaling factor between them. Experimental results reveal that the 3-dB linewidth of dual-ring PT symmetry BFL with an UP-MZI is about 4.85 Hz with the threshold input power of 9.5 mW, in accordance with the 97 Hz measured linewidth at the -20 dB power point. Within 60 mins of the stability experiment, the power and frequency stability fluctuation are ±0.02 dB and ±0.137 kHz, respectively. Thanks to the two asymmetric ring lengths, the sidemode suppression ratio (SMSR) is optimized by 54 dB compared to that with the only long ring structure, 26 dB when using only the Vernier effect or 12 dB for existing PT symmetry BFL. This BFL design with single longitudinal mode and high SMSR output can be applied to high coherent communication and Brillouin-based microwave photonics systems with low phase noise.

Chaihu Longgu Muli Decoction for post-stroke insomnia: A protocol for systematic review and meta-analysis.

BACKGROUND: Poststroke insomnia (PSI) is a frequent complication of stroke usually as a comorbidity of poststroke depression and mainly occurs within the first 6 months after stroke.[1] Addressing PSI to improve stroke prognosis is of great value. Herbal medicine like Chaihu Longgu Muli Decoction (CLMD), which is commonly considered to be a good treatment for depression and epilepsy, has the therapeutic potential on PSI; however, insufficient systematic reviews were conducted to testify its efficacy. Therefore, the objective of this paper is to provide reliable evidence of the efficacy and safety of CLMD on PSI and a foundation for further investigation. METHODS: The literature of clinical randomized controlled trials (RCTs) regarding CLMD for PSI published before June of 2021 will be retrieved in the databases, and 2 investigators will be asked to collect and crosscheck the data independently. For the including studies, the quality evaluation on methodology will be assessed in the light of the Cochrane Handbook for Systematic Review of Interventions V.5.1.0 as well as the quality of evidence will be evaluated by the Grading of Recommendations Assessment, Development, and Evaluation. Besides, the assessment of heterogeneity and reporting bias, the sensitivity analysis and the subgroup analysis will be conducted. Stata 15 will be applied to analyze the above data. RESULTS: The review will conduct a high-quality synthesis on present evidence of CLMD for PSI. CONCLUSION: The conclusion of the study will indicate whether CLMD is effective and safe for PSI.

Colorimetric Detection of Met Dimerization on Live Cells via Smartphone for High-Sensitivity Sensing of the HGF/Met Signaling Pathway.

Membrane protein dimerization regulates numerous cellular biological processes; therefore, highly sensitive and facile detection of membrane protein dimerization are very crucial for clinical diagnosis and biomedical research. Herein, a colorimetric detection of Met dimerization on live cells via smartphone for high-sensitivity sensing of the HGF/Met signaling pathway was developed for the first time. The Met monomers on live cells were recognized by specific ligands (aptamers) first, and the Met dimerizations triggered the proximity-ligation-assisted catalytic hairpin assembly (CHA) reaction to generate large amounts of G-quadruplex (G4) fragments which can further combine hemin to form G4/hemin DNAzymes possessing the horseradish-peroxidase-like catalytic activity for catalyzing the oxidation of ABTS by H2O2 and producing the colorimetric signal (i.e., color change). The colorimetric detection of Met on live cells was then achieved by image acquisition and processing via a smartphone. As a proof-of-principle, the HGF/Met signaling pathway based on Met-Met dimerization was facile monitored, and the human gastric cancer cells MKN-45 with natural Met-Met dimers were sensitively tested and a wide linear working range from 2 to 1000 cells with a low detection limit of 1 cell was obtained. The colorimetric assay possesses a good specificity and high recovery rate of MKN-45 cells spiked in peripheral blood, which indicates that the proposed colorimetric detection of Met dimerization can be used for convenient observation of the HGF/Met signaling pathway and has extensive application prospects in point-of-care testing (POCT) of Met-dimerization-related tumor cells.

A novel cascade signal amplification strategy integrating CRISPR/Cas13a and branched hybridization chain reaction for ultra-sensitive and specific SERS detection of disease-related nucleic acids.

The molecular diagnosis of disease by high-sensitively and specifically detecting extremely trace amounts of nucleic acid biomarkers in biological samples is still a great challenge, and the powerful sensing strategy has become an urgent need for basic researches and clinical applications. Herein, a novel one-pot cascade signal amplification strategy (Cas13a-bHCR) integrating CRISPR/Cas13a system (Cas13a) and branched hybridization chain reaction (bHCR) was proposed for ultra-highly sensitive and specific SERS assay of disease-related nucleic acids on SERS-active silver nanorods sensing chips. The Cas13a-bHCR based SERS assay of gastric cancer-related miRNA-106a (miR-106a) can be achieved within 60 min and output significantly enhanced SERS signal due to the multiple signal amplification, which possesses a good linear calibration curve from 10 aM to 1 nM with the limit of detection (LOD) low to 8.55 aM for detecting gastric cancer-related miR-106a in human serum. The Cas13a-bHCR based SERS sensing also shows good specificity, uniformity, repeatability and reliability, and has good practicability for detection of miR-106a in clinical samples, which can provide a potential powerful tool for SERS detection of disease-related nucleic acids and promise brighter prospects in the field of clinical diagnosis of early disease.

Effect of different acupuncture and moxibustion methods on functional dyspepsia caused by sequelae of COVID-19: A protocol for systematic review and meta-analysis.

BACKGROUND: Functional dyspepsia (FD) is a group of diseases that cannot be explained after routine clinical examination, and is characterized by postprandial fullness, early satiety, and upper abdominal pain or burning. According to the statistics, FD continues to become one of the high-risk sequelae of coronavirus disease 2019 (COVID-19), affecting patients' quality of life, increasing psychological burden and increasing economic costs. However, its optimal treatment is still an urgent problem. A large number of studies have shown that acupuncture and moxibustion is effective and safe in the treatment of FD caused by sequelae of COVID-19, which is of research value. Therefore, based on the current literatures, the effectiveness and safety of different acupuncture and moxibustion methods were systematically evaluated to provide possible alternative therapy on FD. METHODS: Studies search for eligible randomized controlled trials that use different acupuncture and moxibustion methods as the sole treatment on FD and their data extraction will be done by 2 researchers. In case of disagreement, a third researcher will be introduced for arbitration. Mean difference or relative risk with fixed or random effect model in terms of 95% confidence interval will be adopted for the data synthesis. To evaluate the risk of bias, the Cochrane risk of bias assessment tool will be utilized. The sensitivity or subgroup analysis will also be conducted when meeting high heterogeneity (I2 > 50%). RESULTS: This meta-analysis will provide an authentic synthesis of different acupuncture and moxibustion methods on FD caused by sequelae of COVID-19. CONCLUSION: This meta-analysis will evaluate the effect of acupuncture and moxibustion on FD caused by sequelae of COVID-19, providing evidence as to the treatment in these patients.

Association Between Poor Nutritional Status and Increased Risk for Subsequent Vertebral Fracture in Elderly People with Percutaneous Vertebroplasty.

Background: The relationship between a poor nutritional state and the risk of fractures has not been investigated. This study aimed to investigate the ability of the Controlling Nutritional Status (CONUT) and Geriatric Nutritional Risk Index (GNRI) to predict the incidence of subsequent vertebral fracture (SVF) after percutaneous vertebroplasty (PVP). Methods: A total of 307 women and 138 men over 50 years old who underwent PVP for osteoporotic vertebral compression fracture (OVCF) were included. Blood biochemical indexes, body mass index (BMI), bone mineral density (BMD), physical function, and muscle strength were measured at baseline. Cox regression analysis was used to determine whether nutritional state was an independent predictor for SVF. Results: During follow-up, 35 (25.4%) men and 85 (27.7%) women suffered SVF. Patients with SVF had lower BMI, serum albumin levels, GNRI scores, grip strength, lumbar BMD, and Short-Physical Performance Battery (SPPB) scores and higher fall rates and CONUT scores (P < 0.05). Compared with normal nutrition, mild malnutrition was associated with higher risk for SVF (women: HR 2.37, p=0.001, men: HR 2.97, p=0.021 by GNRI; women: HR 2.36, p=0.005, men: HR 3.62, p=0.002 by CONUT) after adjusting for confounding factors. Those with moderate-severe malnutrition also had a higher risk of SVF. Kaplan-Meier analysis showed that poor nutrition state was significantly associated with lower SVF-free survival (P<0.05). The area under curve (AUC) for predicting SVF was 0.65 and 0.73 for the GNRI and 0.67 and 0.66 for the CONUT in men and women, respectively. Conclusion: GNRI and CONUT are simple and effective tools for predicting SVF in patients undergoing PVP. Health management and nutrition supplement after PVP is a potentially effective prevention strategy against SVF.

Provincial heterogeneity in the management of care cascade for hypertension, diabetes, and dyslipidaemia in China: Analysis of nationally representative population-based survey.

Background: This study aims to examine (1) province-level variations in the levels of cardiovascular disease (CVD) risk and behavioral risk for CVDs, (2) province-level variations in the management of cascade of care for hypertension, diabetes, and dyslipidaemia, and (3) the association of province-level economic development and individual factors with the quality of care for hypertension, diabetes, and dyslipidaemia. Methods: We used nationally representative data from the China Health and Retirement Longitudinal Study in 2015, which included 12,597 participants aged 45 years. Using a care cascade framework, we examined the quality of care provided to patients with three prevalent NCDs: hypertension, diabetes, and dyslipidaemia. The proportion of WHO CVD risk based on the World Health Organization CVD risk prediction charts, Cardiovascular Risk Score (CRS) and Behavior Risk Score (BRS) were calculated. We performed multivariable logistic regression models to determine the individual-level drivers of NCD risk variables and outcomes. To examine socio-demographic relationships with CVD risk, linear regression models were applied. Results: In total, the average CRS was 4.98 (95% CI: 4.92, 5.05), while the average BRS was 3.10 (95% confidence interval: 3.04, 3.15). The weighted mean CRS (BRS) in Fujian province ranged from 4.36 to 5.72 (P < 0.05). Most of the provinces had a greater rate of hypertension than diabetes and dyslipidaemia awareness and treatment. Northern provinces had a higher rate of awareness and treatment of all three diseases. Similar patterns of regional disparity were seen in diabetes and dyslipidaemia care cascades. There was no evidence of a better care cascade for CVDs in patients who reside in more economically advanced provinces. Conclusion: Our research found significant provincial heterogeneity in the CVD risk scores and the management of the cascade of care for hypertension, diabetes, and dyslipidaemia for persons aged 45 years or more. To improve the management of cascade of care and to eliminate regional and disparities in CVD care and risk factors in China, local and population-based focused interventions are necessary.

Simultaneous Visualization of Dual Intercellular Signal Transductions via SERS Imaging of Membrane Proteins Dimerization on Single Cells.

The visualization of protein dimerization on live cells is an urgent need and of vital importance for facile monitoring the signal transduction during intercellular communication. Herein, a highly sensitive and specific SERS strategy for simultaneously imaging dual homodimerizations of membrane proteins on single live cells was proposed by networking of AuNPs-based dual-recognition probes (dual-RPs) and SERS tags via proximity ligation-assisted catalytic hairpin assembly (CHA). The dual-RPs were prepared by comodifying hairpin-structured ssDNAs H1-Met and H1-TßRII on 50 nm AuNPs and two SERS tags for membrane proteins Met and TßRII were prepared respectively by labeling their corresponding Raman molecules and hairpin-structured single-stranded DNAs H2-Met or H2-TßRII on 15 nm AuNPs. The membrane proteins were ligated proximally by specific aptamers, and the dimerizations of proteins resulted in the proximity ligation-assisted CHA-based networking of dual-RPs and SERS tags to form 15Au-50Au network nanostructures with significantly enhanced SERS effect. The SERS strategy for visualizing the membrane protein dimerization was established and the good performance on simultaneously SERS imaging dual dimerizations of membrane proteins (i.e., Met-Met and TßRII-TßRII) was confirmed. Furthermore, the membrane protein dimerization-based signaling pathways between cancer cells and stromal cells or stem cells were observed by SERS, which indicates that the proposed SERS strategy is a good method for high-sensitivity monitoring of membrane proteins dimerizations-based multiple intercellular signal transductions in a natural and complex cellular microenvironment.

Computed tomography-based paravertebral muscle density predicts subsequent vertebral fracture risks independently of bone mineral density in postmenopausal women following percutaneous vertebral augmentation.

BACKGROUND: The risk of subsequent vertebral fractures (SVF) after the primary vertebral fracture cannot be explained by lower bone mineral density (BMD) alone. Computed tomography (CT) measurements of paravertebral muscle density (PMD) are recognized radiographic markers used to predict physical function, fragile fractures. AIMS: This study aims to investigate the relationship between PMD and the risk of SVF in cohorts of postmenopausal women, and to determine if combining both PMD and BMD measures derived from CT can improve the accuracy of predicting SVF. METHODS: This study enrolled 305 postmenopausal women between the ages of 50 and 88 for 3 years of follow-up studies. Trabecular attenuation (Hounsfield units, HU) was measured at L1 level and muscle attenuation of paravertebral muscle at L3 level on preoperative lumbar CT scans to determine the L1 BMD and L3 PMD. Kaplan-Meier analysis was applied to evaluate SVF-free survival. The hazard ratios (HRs) of PMD for SVF events were estimated with the Cox proportional hazards model. The predictive values of L1 BMD and L3 PMD for SVF were quantified using the Receiver-Operating Characteristic (ROC) curve. RESULT: During the 3 years of follow-up studies, 88 patients (28.9%) suffered an SVF. ROC curve analysis demonstrated that an L3 PMD threshold of 32 HU had a sensitivity of 89.8% and a specificity of 62% for the prediction of SVF. Kaplan-Meier analysis showed that L3 PMD ≤ 32 HU was significantly associated with lower SVF-free survival (p < 0.001; log-rank test). After adjusting for age, BMI, diabetes, postoperative osteoporosis treatment, handgrip strength, L1 BMD, multivariate analyses also indicated a persistent modest effect of L3 PMD on SVF-free survival. The area under the ROC curve of L3 PMD and L1 BMD, combined to predict the risk of SVF, was 0.790, which was significantly higher than the value for L1 BMD alone (0.735). L3 PMD and L1 BMD significantly improved the accuracy of SVF risk prediction compared with L1 BMD alone, which was confirmed by reclassification improvement measures. The inclusion of handgrip strength and postoperative osteoporosis treatment in the model further improved SVF prediction accuracy, and PMD remained significant in the model. CONCLUSION: Decreased L3 PMD is an independent risk predictor of SVF. Combined CT-based L1 BMD and L3 PMD can significantly improve the accuracy of predicting the risk of SVF in postmenopausal women who have suffered prior osteoporotic vertebral fractures.

Bacterial Succession in Microbial Biofilm as a Potential Indicator for Postmortem Submersion Interval Estimation.

Bacteria acts as the main decomposer during the process of biodegradation by microbial communities in the ecosystem. Numerous studies have revealed the bacterial succession patterns during carcass decomposition in the terrestrial setting. The machine learning algorithm-generated models based on such temporal succession patterns have been developed for the postmortem interval (PMI) estimation. However, the bacterial succession that occurs on decomposing carcasses in the aquatic environment is poorly understood. In the forensic practice, the postmortem submersion interval (PMSI), which approximately equals to the PMI in most of the common drowning cases, has long been problematic to determine. In the present study, bacterial successions in the epinecrotic biofilm samples collected from the decomposing swine cadavers submerged in water were analyzed by sequencing the variable region 4 (V4) of 16S rDNA. The succession patterns between the repeated experimental settings were repeatable. Using the machine learning algorithm for establishing random forest (RF) models, the microbial community succession patterns in the epinecrotic biofilm samples taken during the 56-day winter trial and 21-day summer trial were determined to be used as the PMSI predictors with the mean absolute error (MAE) of 17.87 ± 2.48 ADD (≈1.3 day) and 20.59 ± 4.89 ADD (≈0.7 day), respectively. Significant differences were observed between the seasons and between the substrates. The data presented in this research suggested that the influences of the environmental factors and the aquatic bacterioplankton on succession patterns of the biofilm bacteria were of great significance. The related mechanisms of such influence need to be further studied and clarified in depth to consider epinecrotic biofilm as a reliable predictor in the forensic investigations.

Exogenous Klotho ameliorates extracellular matrix degradation and angiogenesis in intervertebral disc degeneration via inhibition of the Rac1/PAK1/MMP-2 signaling axis.

Intervertebral disc degeneration (IDD) is highly ubiquitous in the aged population and is an essential factor for low back pain and spinal disability. Because of the association between IDD and senescence, we investigated the ability of the anti-aging drug Klotho to inhibit age-dependent advancement of nucleus pulposus cell (NPC) degeneration. The results indicated that 400 pM exogenous Klotho significantly ameliorated extracellular matrix degradation and angiogenesis. Moreover, we demonstrated that the suppression of angiogenesis and extracellular matrix catabolism was related to inhibition of the Ras-related C3 botulinum toxin substrate 1 (Rac1)/PAK1 axis and matrix metalloproteinase 2 protein expression by exogenous Klotho cotreatment with a Rac1 inhibitor, gene overexpression in NPCs, and stimulation of human umbilical vein endothelial cells with conditioned medium from NPCs. The treatment also preserved the NPC phenotype, viability, and matrix content. In conclusion, these results suggest that the new anti-aging drug Klotho is a potential treatment strategy to mitigate IDD, and thus, provides an innovative understanding of the molecular mechanism of IDD. DATA AVAILABILITY: All data supporting the findings of this study are available from the corresponding authors upon reasonable request.

DNA walker-powered ratiometric SERS cytosensor of circulating tumor cells with single-cell sensitivity.

Identification and detection of extreme rare circulating tumor cells (CTCs) in peripheral blood can precisely monitor cancer recurrence and metastasis, however, how to ultra-sensitively and reliably detect CTCs is a big challenge. In this work, a ratiometric surface-enhanced Raman spectroscopy (SERS)-based strategy for ultra-sensitively and nondestructively detecting CTCs was proposed via CTCs-triggered DNA walker-assisted assembly of plasmonic nanostructure networks consisting of Walker probes and SERS tags. The Walker probes were prepared by modifying Fe3O4@SiO2@Au nanoparticles (GMNPs) with ROX-labeled EpCAM aptamer-blocked Zn2+-specific DNAzyme and hairpin-structured single-stranded DNAs H1, and the SERS tags were constructed by co-labelling hairpin-structured single-stranded DNAs H2 and Raman molecules (DTNB) on Au NPs. The aptamers can recognize EpCAM-positive CTCs via the specific binding to EpCAM, so that the activity of DNAzymes is activated with the assistance of Zn2+ to launch the DNA walker to move around for the cleavage of H1 on GMNPs. The residual fragments of H1 on GMNPs can hybridize with H2 on SERS tags and result in the formation of Walker probe-SERS tag network nanostructures (Nw NSs) with rich SERS hot spots. The reliable SERS detection of CTCs is achieved by the stable ratiometric SERS signals of DTNB and ROX generated from the Nw NSs, and a good linear relation between ratiometric SERS signal and MCF-7 cells concentration was obtained with the detection limit low to 1 cell/mL. The recovery rate of MCF-7 cells in peripheral blood is in the range of 94.0%-104.5%, which indicates a good application prospect of the novel ratiometric SERS cytosensor in the clinic detection of EpCAM-positive CTCs.