Photoelectrothermocatalytic reduction of CO2 to glycol via Cu2S/MoS2-Vs octahedral heterostructure with synergistic mechanism

The defects and interface engineering are efficient approaches to adjust the physical and chemical properties of nanomaterials to enhance catalytic performance. In this study, we report a new MOFs-driven porous Cu2S/MoS2-Vs octahedral semiconductor with heterostructure and photothermal effect. The introduction of sulfur vacancies directly improves the adsorption performance of CO2, and the formation of heterostructure significantly increases the charge transfer rate. The C-penetrating material obtained from MOFs not only acts as an octahedral skeleton support, but also gives photothermal effects under photoelectric conditions. The formation rate of sole C2 products in photoelectrocatalytic CO2 reduction by using Cu2S/MoS2-Vs heterostructure is up to 52 μM·h-1·cm-2 equal to the total electron transfer rate of 541 μM·h-1·cm-2. The carbene mechanism and reaction pathways were proposed and verified by 13CO2 isotopic labelling and operando Fourier transform infrared (FT-IR) spectra. The important intermediates of *CO2-, *CO, *CHO and *CHO-CHO were identified by operando FT-IR spectra. In the comparative experiments, the photothermal electrons are beneficial to C2 products. DFT calculations indicate that the presence of S vacancies (Vs) reduces the energy barrier for product generation.

[Dosimetric analysis of different optimization algorithms for three-dimensional brachytherapy for gynecologic tumors]

OBJECTIVE

To investigate the dosimetric difference between manual and inverse optimization in 3-dimensional (3D) brachytherapy for gynecologic tumors.

METHODS

This retrospective study was conducted among a total of 110 patients with gynecologic tumors undergoing intracavitary combined with interstitial brachytherapy or interstitial brachytherapy. Based on the original images, the brachytherapy plans were optimized for each patient using Gro, IPSA1, IPSA2 (with increased volumetric dose limits on the basis of IPSA1) and HIPO algorithms. The dose-volume histogram (DVH) parameters of the clinical target volume (CTV) including V200, V150, V100, D90, D98 and CI, and the dosimetric parameters D2cc, D1cc, and D0.1cc for the bladder, rectum, and sigmoid colon were compared among the 4 plans.

RESULTS

Among the 4 plans, Gro optimization took the longest time, followed by HIPO, IPSA2 and IPSA1 optimization. The mean D90, D98, and V100 of HIPO plans were significantly higher than those of Gro and IPSA plans, and D90 and V100 of IPSA1, IPSA2 and HIPO plans were higher than those of Gro plans (P < 0.05), but the CI of the 4 plans were similar (P > 0.05). For the organs at risk (OARs), the HIPO plan had the lowest D2cc of the bladder and rectum; the bladder absorbed dose of Gro plans were significantly greater than those of IPSA1 and HIPO (P < 0.05). The D2cc and D1cc of the rectum in IPSA1, IPSA2 and HIPO plans were better than Gro (P < 0.05). The D2cc and D1cc of the sigmoid colon did not differ significantly among the 4 plans.

CONCLUSION

Among the 4 algorithms, the HIPO algorithm can better improve dose coverage of the target and lower the radiation dose of the OARs, and is thus recommended for the initial plan optimization. Clinically, the combination of manual optimization can achieve more individualized dose distribution of the plan.

Tongue-Coating Microbial and Metabolic Characteristics in Halitosis

Halitosis is a common oral condition, which leads to social embarrassment and affects quality of life. Cumulative evidence has suggested the association of tongue-coating microbiome with the development of intraoral halitosis. The dynamic variations of tongue-coating microbiota and metabolites in halitosis have not been fully elucidated. Therefore, the present study aimed to determine the tongue-coating microbial and metabolic characteristics in halitosis subjects without other oral diseases using metagenomics and metabolomics analysis. The participants underwent oral examination, halitosis assessment, and tongue-coating sample collection for the microbiome and metabolome analysis. It was found that the microbiota richness and diversity were significantly elevated in the halitosis group. Furthermore, species from Actinomyces, Prevotella, Veillonella, and Solobacterium were significantly more abundant in the halitosis group. However, the Rothia and Streptococcus species exhibited opposite tendencies. Eleven Kyoto Encyclopedia of Genes and Genomes pathways were significantly enriched in the halitosis tongue coatings, including cysteine and methionine metabolism. Functional genes related to sulfur, indole, skatole, and cadaverine metabolic processes (such as serA, metH, metK and dsrAB) were identified to be more abundant in the halitosis samples. The metabolome analysis revealed that indole-3-acetic, ornithine, and L-tryptophan were significantly elevated in the halitosis samples. Furthermore, it was observed that the values of volatile sulfur compounds and indole-3-acetic abundances were positively correlated. The multiomics analysis identified the metagenomic and metabolomic characteristics to differentiate halitosis from healthy individuals using the least absolute shrinkage and selection operator logistic regression and random forest classifier. A total of 19 species and 39 metabolites were identified as features in halitosis patients, which included indole-3-acetic acid, Bacillus altitudinis, Candidatus Saccharibacteria, and Actinomyces species. In conclusion, an evident shift in microbiome and metabolome characteristics was observed in the halitosis tongue coating, which may have a potential etiological significance and provide novel insights into the mechanism for halitosis.

TiO2 nanorod arrays@PDA/Ag with biomimetic polydopamine as binary mediators for duplex SERS detection of illegal food dyes

Based on TiO2 nanorod arrays@PDA/Ag (TNRs@PDA/Ag), a better surface-enhanced Raman scattering (SERS) sensor with effective enrichment and enhancement was investigated for duplex SERS detection of illicit food dyes. Biomimetic PDA functions as binary mediators by utilizing the structural characteristics of polydopamine (PDA), which include the conjugated structure and abundant hydrophilic groups. One PDA functioned as an electron transfer mediator to enhance the efficiency of electron transfer, and the other as an enrichment mediator to effectively enrich rhodamine B (RhB) and crystal violet (CV) through hydrogen bonding, π-π stacking, and electrostatic interactions. Individual and duplex detection of illicit food dyes (RhB and CV) was performed using TNRs@PDA/Ag to estimate SERS applications. Their linear equations and limits of detection of 1 nM for RhB and 5 nM for CV were derived. Individual and duplex food colour detection was successfully accomplished even in genuine chili meal with good results. The bifunctional TNRs@PDA/Ag-based highly sensitive and duplex SERS dye detection will have enormous potential for food safety monitoring.

Impact of Differential Rates of Disease Progression in Amyloid-Positive Early Alzheimer's Disease: Findings from a Longitudinal Cohort Analysis

BACKGROUND

There is limited literature regarding the impact of differential rates of disease progression on longitudinal outcomes in individuals with early Alzheimer's disease (AD) and confirmed brain amyloid pathology.

OBJECTIVES

To describe the underlying characteristics and long-term outcomes associated with different rates of disease progression among amyloid-positive individuals with early symptomatic AD.

DESIGN

Retrospective observational study.

SETTING

Data from the National Alzheimer's Coordinating Center (NACC) Uniform Data Set (UDS) in the United States (06/2005-11/2021).

PARTICIPANTS

Individuals with a clinical assessment of mild cognitive impairment or dementia and Clinical Dementia Rating® Dementia Staging Instrument Sum of Boxes (CDR-SB) score 0.5-9.0 (inclusive; first visit defined as the index date) and confirmed amyloid positivity. Participants were stratified into No Progression (change ≤0), Slower Progression (0< change <2.0 points), Median Progression (2.0-point change), and Faster Progression (change >2.0 points) cohorts based on the observed distribution of changes in CDR-SB score between the index and first subsequent visit.

MEASUREMENTS

For each cohort, the functional and neuropsychiatric outcomes were described at index and each subsequent visit for up to five years, and least-square (LS) mean changes from baseline were estimated using linear mixed-effects models adjusting for baseline demographic and clinical characteristics.

RESULTS

Among 1,263 participants included in the analysis, the mean±standard deviation (SD) age at index was 72.7±9.7 years and 55.3% were males. Demographic characteristics and comorbidity profiles at index were similar across cohorts. However, at index, the Faster Progression (N=279) cohort had higher CDR-SB and Functional Assessment Questionnaire (FAQ) scores compared with the No Progression (N=474), Slower Progression (N=297), and Median Progression (N=213) cohorts. Adjusting for baseline characteristics, at year 5 after index the FAQ score increased by 23.6 points for Faster Progression cohort and 10.4, 15.8, and 19.2 points for the No, Slower, and Median Progression cohorts, respectively. The corresponding increases in Neuropsychiatric Inventory Questionnaire (NPI-Q) scores were 6.7 points for the Faster Progression cohort, and by 1.3, 3.1, and 8.3 points, for the No, Slower, and Median Progression cohorts, respectively.

CONCLUSIONS

Despite similar demographic and clinical profiles at baseline, amyloid-positive individuals with greater deterioration based on CDR-SB early in the AD trajectory continue to experience worse functional and behavioral outcomes over time than those with more gradual deterioration in this metric.

Potential Implications of Slowing Disease Progression in Amyloid-Positive Early Alzheimer's Disease: Estimates from Real-World Data

BACKGROUND

Emerging therapies have shown promising results for slowing the progression of Alzheimer's disease (AD). However, the potential impact of these therapies on real-world outcomes remains to be explored.

OBJECTIVE

To examine the impact of slowing AD progression on functional abilities and behavioral symptoms.

DESIGN

Retrospective observational study.

SETTING

Data from the National Alzheimer's Coordinating Center (NACC) Uniform Data Set (UDS) in the United States (06/2005-11/2021, primary analysis) and the Alzheimer's Disease Neuroimaging Initiative (ADNI) database (09/2005-03/2022, sensitivity analysis) were used.

PARTICIPANTS

Individuals with mild cognitive impairment (MCI) or mild dementia, Clinical Dementia Rating Scale Sum of Boxes (CDR-SB) score 0.5-9.0 (inclusive; first visit defined as the index date), and confirmed amyloid positivity were identified in NACC. In ADNI, individuals with at least one clinical center visit with a clinical assessment of MCI or mild dementia and confirmed amyloid positivity were identified.

MEASUREMENTS

Hypothetical effects of slowing disease progression as assessed by CDR-SB on functional and behavioral outcomes including the Functional Activities Questionnaire (FAQ) score, Neuropsychiatric Inventory Questionnaire (NPI-Q) score, and the probability of complete dependence over five years were evaluated using multivariable regression among NACC participants, separately for the subgroups with MCI and mild dementia at baseline, respectively. For the ADNI sensitivity analysis, the hypothetical effects of slowing disease progression were evaluated for FAQ score using multivariable regression among the MCI participants only.

RESULTS

Compared with natural disease progression, slowing progression by 20% over five years for NACC participants with MCI and mild dementia, respectively, would result in 1.7-point (10.8%) and 1.6-point (12.9%) less deterioration based on FAQ; 0.5-point (20.3%) and 0.5-point (19.3%) less deterioration based on NPI-Q; 4.7 percentage-point (22.2%) and 10.1 percentage-point (21.6%) lower probability of complete dependence. Among ADNI participants, delaying disease progression by 20% or 30% over 4 years would avert deterioration based on FAQ of 1.1 points (20.4%) and 1.6 points (29.6%), respectively, compared to natural disease progression.

CONCLUSIONS

Slowing early AD progression could result in preservation of functional and behavioral attributes and functional autonomy for longer.

PVP-capped silver nanoparticles for efficient SERS detection of adenine based on the stabilizing and enrichment roles of PVP

A polyvinylpyrrolidone-capped (PVP-capped) strategy is reported to synthesize Ag NPs on silicon wafers via galvanic replacement reaction for SERS detection of adenine, where PVP acts as stabilizing agent in synthesis and efficient enrichment in detection. The morphologies of Ag NPs are optimized with uniform particle size by adjusting synthesis conditions, which hold excellent SERS performances like a high enhancement factor of 1.42 × 106, good uniform, reproducibility, and transferable nature. With the protection of the capped PVP, the Ag NPs keep excellent SERS properties even against harsh conditions of high temperature (100 ℃) and strong acid and base for 24 h. Utilizing the structural feature of PVP with abundant carbonyl groups, the PVP-capped Ag NPs achieve efficient enrichment of adenine through hydrogen bonding and π-interactions, which is analyzed by density functional theory. Quantitative detection of adenine is performed with a wide linear range from 10-4 to 10-8 M and a low limit of detection of 1 nM. Detection of adenine in human urine samples is achieved with a recovery of 99.1-103.4% and an RSD of less than 5%.

Global burden of neoplasms attributable to specific occupational carcinogens over 30 years: a population-based study

OBJECTIVES

The study aimed to analyze the global burden of occupational neoplasms from various epidemiological perspectives.

STUDY DESIGN

In this cross-sectional study, secondary analyses were conducted to assess the burden of neoplasms attributable to occupational carcinogens and their distribution characteristics using data from GBD 2019 and the World Bank database.

METHODS

Based on the GBD 2019 and the World Bank database, we analyzed the global burden of occupational neoplasms including the age-period-cohort model, decomposition analysis, health inequality analysis, and panel model. All analyses were conducted in R (version 4.0.3) and Joinpoint (version 4.9.1).

RESULTS

The absolute number of neoplasms burden attributable to occupational carcinogens has continued to rise over 30 years. In 2019, occupational neoplasms caused 333,867 [95% uncertainty interval (UI): 263,491 to 404,641] mortalities and 6,964,775 (95% UI: 5,467,884 to 8,580,431) disability-adjusted life years (DALYs) globally. Greenland, Monaco, the Netherlands, and Andorra suffered the highest burden. The burden was higher in countries with a higher sociodemographic index. The age effect was prominent in the elderly, and the 1925 birth cohort had the highest cohort effect. Population growth was the most significant driver of the mortalities (89%) and DALYs (111%) change. Moreover, the proportion of urban population was significantly positively associated with the disease burden, while GDP per capita was negatively correlated with the disease burden.

CONCLUSIONS

The burden of occupational neoplasms was unevenly distributed across locations and populations. The need for rational allocation of healthcare resources was urgent.

[Inhibitor of growth protein-2 silencing alleviates angiotensin Ⅱ-induced cardiac remodeling in mice by reducing p53 acetylation]

OBJECTIVE

To investigate the effect of inhibitor of growth protein-2 (Ing2) silencing on angiotensin Ⅱ (AngⅡ)-induced cardiac remodeling in mice and explore the underlying mechanism.

METHODS

An adenoviral vector carrying Ing2 shRNA or empty adenoviral vector was injected into the tail vein of mice, followed 48 h later by infusion of 1000 ng · kg^-1 · min^-1 Ang Ⅱ or saline using a mini-osmotic pump for 42 consecutive days. Transthoracic echocardiography was used to assess cardiac geometry and function and the level of cardiac hypertrophy in the mice. Masson and WGA staining were used to detect myocardial fibrosis and cross-sectional area of cardiomyocytes, and myocardial cell apoptosis was detected with TUNEL assay. Western blotting was performed to detect myocardial expressions of cleaved caspase 3, ING2, collagen Ⅰ, Ac-p53(Lys382) and p-p53 (Ser15); Ing2 mRNA expression was detected using real-time PCR. Mitochondrial biogenesis, as measured by mitochondrial ROS content, ATP content, citrate synthase activity and calcium storage, was determined using commercial assay kits.

RESULTS

The expression levels of Ing2 mRNA and protein were significantly higher in the mice with chronic Ang Ⅱ infusion than in saline-infused mice. Chronic infusion of AngⅡ significantly increased the left ventricular end-systolic diameter (LVESD) and left ventricular end-diastolic diameter (LVEDD) and reduced left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) in the mice. Ing2 silencing obviously alleviated AngⅡ-induced cardiac function decline, as shown by decreased LVEDD and LVESD and increased LVEF and LVFS, improved myocardial mitochondrial damage and myocardial hypertrophy and fibrosis, and inhibited cardiomyocyte apoptosis. Chronic AngⅡ infusion significantly increased myocardial expression levels of Ac-p53(Lys382) and p-p53(Ser15) in the mice, and Ing2 silencing prior to AngⅡ infusion lessened AngⅡ- induced increase of Ac-p53(Lys382) without affecting p53 (ser15) expression.

CONCLUSION

Ing2 silencing can inhibit AngⅡ-induced cardiac remodeling and dysfunction in mice by reducing p53 acetylation.

Carbon ion irradiation induces DNA damage in melanoma and optimizes the tumor microenvironment based on the cGAS-STING pathway

PURPOSES

Increased number of studies reveal the crucial role of the Cyclic GMP-AMP synthase/stimulator of interferon genes (cGAS/STING) pathway in anti-tumor immunity. In this study, we aim to explore the effect of cGAS/STING on tumor immune microenvironment of melanoma after carbon ion radiotherapy (CIRT) and the underlying mechanism.

METHODS

C57BL/6 mouse tumor models were used to evaluate the efficacy of different treatments (X-ray, carbon ion, PD-L1 inhibitor and combination therapies) on tumor growth and process. Mass cytometry was performed to assess tumor-infiltrating lymphocytes (TILs). DNA damage response (DDR) and cGAS/STING pathway were investigated by immunofluorescence-co-localization assays, γ-H2AX, P53-binding protein 1 (53BP1), Breast Cancer 1 (BRCA1), and cGAS measurements.

RESULTS

Carbon ion irradiation caused more DNA damages and cGAS-STING pathway activation compared with X-ray irradiation, and the former slowed the melanoma growth in syngeneic model. Although X-ray irradiation is not sensitive for melanoma treatment, carbon ion irradiation showed a significant anti-tumor effect for melanoma treatment. TILs analysis revealed that CIRT boosted the infiltration of natural killer (NK), CD4⁺, and CD8⁺ T cells, meanwhile increased the number of immune checkpoint (programmed death-1, PD-1, lymphocyte activation gene 3, LAG-3 and T-cell immunoglobulin and mucin domain-containing protein 3, TIM-3). Moreover, CIRT increased PD-L1 exposure on cell surface compared with X-ray group. Furthermore, CIRT combined with PD-L1 inhibitor therapy increased the number of T cells and NK cells in melanoma, and slowed the growth of melanoma compared with other therapies.

CONCLUSIONS

Our findings showed that CIRT displayed biological effects by increasing DNA damages of tumor cells and improving immunity in melanoma, which indicated that CIRT might be a potential synergetic treatment for radiotherapy and radioimmunotherapy in melanoma patients. Our works put forward a new insight to provide an effective strategy for melanoma therapy. These findings may help in the design of strategies on melanoma in clinical studies.

A novel causal model for nasopharyngeal carcinoma

The development of nasopharyngeal carcinoma (NPC) and its unique geographic distribution have long been attributed to a combination of dietary intake of salt-preserved fish, inherited susceptibility, and early-life infection with the Epstein-Barr virus (EBV). New findings from our large, rigorously designed, population-based case-control study of NPC in southern China have enabled substantial revision of this causal model. Here, we briefly summarize these results and provide an updated model of the etiology of NPC. Our new research identifies two EBV genetic variants that may be causally involved in the majority of NPC in southern China, and suggests the rise of modern environmental co-factors accompanying cultural and economic transformation in NPC-endemic regions. These discoveries can be translated directly into clinical and public health advances, including improvement of indoor air quality and oral health, development of an EBV vaccine, enhanced screening strategies, and improved risk prediction. Greater understanding of the roles of environmental, genetic, and viral risk factors can reveal the extent to which these agents act independently or jointly on NPC development. The history of NPC research demonstrates how epidemiology can shed light on the interplay of genes, environment, and infections in carcinogenesis, and how this knowledge can be harnessed for cancer prevention and control.

P-380 Single-cell transcriptome analysis reveales that expression changes of the endometrium in repeated implantation failure are altered by HPV-mediated CXCL chemokine secretion

Study question

What are the mechanisms and molecular expression patterns of reduced endometrial receptivity in repeated implantation failure (RIF) after human papillomavirus (HPV) infection?

Summary answer

The single-cell transcriptomic analysis identifies the expression changes of endometrium in RIF via HPV-mediated CXCL chemokines secretion in single-cell resolution.

What is known already

Regardless of the advance of in vitro fertilization (IVF), RIF is still a formidable challenge for couples and physicians in clinical treatment. In infertile couples, a reduction in natural and assisted cumulative pregnancy rate and an increase in miscarriage rate are related to the HPV infection.

Study design, size, duration

Cross-sectional clinical studies with 322 infertile couples undergoing IVF were integrated to demonstrate the associations between HPV infection and reproductive outcomes (pregnancy rate and miscarriage). Descriptive analysis of single-cell transcriptome data of uteruses, and transcriptome profiles of mid-secretory endometrium from 16 healthy fertile women and 38 repeated IVF failure women were analyzed to identify the expression patterns of endometrium in RIF. In vitro assays were used to validate the expression patterns in endometrium.

Participants/materials, setting, methods

322 infertile couples, single-cell transcriptome data of uteruses (human and mouse), and transcriptome profiles of endometrium (16 normal vs. 38 RIF) were used to analyze the association between HPV infection and reduced endometrial receptivity. HPV genes (E1, E2, E4, and E5) were transfected into a human normal endometrial epithelial cell line (hEM3), and immunohistochemistry, Westerns, quantitative PCR were used to validate the changes of CXCL chemokines in the endometrium in vitro.

Main results and the role of chance

Integrated cross-sectional studies demonstrate that HPV+ women exhibit a decreased pregnancy rate (83.09%) as compared with HPV- women (55.17%, P &lt;0.001), and a higher miscarriage rate (62.5% vs. 16.7%, P &lt;0.001) and the relative risk of spontaneous abortion (odd ratio=2.84, P &lt;0.0001) were observed in HPV+ women. Transcriptome profiling analysis identified the enrichment of the processes related to viral protein interaction with cytokine and cytokine receptor and cytokine-cytokine receptor interaction, especially in the CXCL chemokine family. Further analysis of single-cell transcriptome demonstrated that the changed expression patterns were associated with endometrial epithelial cells and immune cells, including macrophage dendritic cells, monocytes, and granulocytes. Moreover, in vitro assays validated the HPV-mediated CXCL chemokines secretion, which played the role in recruiting immune cells.

Limitations, reasons for caution

The current findings are based on the single-cell profiling analysis in normal endometrium. In addition, the in vivo response of the HPV infection may differ from the in vitro assay, which should be validated in the HPV infection couples.

Wider implications of the findings

Our study demonstrated the expression changes of endometrium in RIF via HPV-mediated CXCL chemokines secretion, which provided insight into the mechanisms of HPV-induced reduced endometrial receptivity in single-cell resolution.

Trial registration number

not applicable

The Role of RAD6B and PEDF in Retinal Degeneration

RAD6B is an E2 ubiquitin-conjugating enzyme, playing an important role in DNA damage repair, gene expression, senescence, apoptosis and protein degradation. However, the specific mechanism between ubiquitin and retinal degeneration requires more investigation. Pigment epithelium-derived factor (PEDF) has a potent neurotrophic effect on the retina, protecting retinal neurons and photoreceptors from cell death caused by pathological damage. In this study, we found that loss of RAD6B leads to retinal degeneration in mice, especially in old age. Affymetrix microarray analysis showed that the PEDF signal was changed in RAD6B deficient groups. The expression of γ-H2AX, β-Gal, P53, Caspase-3, P21 and P16 was increased significantly in retinas of RAD6B knockout (KO) mice. Our studies suggest that RAD6B and PEDF play an important role in the health of retina, whereas the absence of RAD6B accelerates the degeneration.

Gallbladder disease and pancreatic cancer risk: a multicentric case-control European study

BACKGROUND AND AIMS

The overall evidence on the association between gallbladder conditions (GBC: gallstones and cholecystectomy) and pancreatic cancer (PC) is inconsistent. To our knowledge, no previous investigations considered the role of tumour characteristics on this association. Thus, we aimed to assess the association between self-reported GBC and PC risk, by focussing on timing to PC diagnosis and tumour features (stage, location, and resection).

METHODS

Data derived from a European case-control study conducted between 2009 and 2014 including 1431 PC cases and 1090 controls. We used unconditional logistic regression models to estimate odds ratios (ORs) and corresponding 95% confidence intervals (CIs) adjusted for recognized confounders.

RESULTS

Overall, 298 (20.8%) cases and 127 (11.6%) controls reported to have had GBC, corresponding to an OR of 1.70 (95% CI 1.33-2.16). The ORs were 4.84 (95% CI 2.96-7.89) for GBC diagnosed <3 years before PC and 1.06 (95% CI 0.79-1.41) for ≥3 years. The risk was slightly higher for stage I/II (OR = 1.71, 95% CI 1.15-2.55) vs. stage III/IV tumours (OR = 1.23, 95% CI 0.87-1.76); for tumours sited in the head of the pancreas (OR = 1.59, 95% CI 1.13-2.24) vs. tumours located at the body/tail (OR = 1.02, 95% CI 0.62-1.68); and for tumours surgically resected (OR = 1.69, 95% CI 1.14-2.51) vs. non-resected tumours (OR = 1.25, 95% CI 0.88-1.78). The corresponding ORs for GBC diagnosed ≥3 years prior PC were close to unity.

CONCLUSION

Our study supports the association between GBC and PC. Given the time-risk pattern observed, however, this relationship may be non-causal and, partly or largely, due to diagnostic attention and/or reverse causation.

Worldwide cancer statistics of adolescents and young adults in 2019: a systematic analysis of the Global Burden of Disease Study 2019

Background

The cancer burden in adolescents and young adults (AYAs) deserves more attention. However, global cancer statistics for AYAs are often presented as aggregates, concealing important heterogeneity. This study aimed to describe the worldwide profile of cancer incidence, mortality, and corresponding trends from 1990 to 2019 among 15-39-year olds by focusing on the patterns by age, sex, sociodemographic index (SDI), and regions.

Patients and methods

Global, regional, and country data on the number of cancer cases and cancer-related deaths for 29 cancer types were collected from the 2019 Global Burden of Disease (GBD) Study. We also summarized the results using five levels of the SDI and 21 GBD regions.

Results

In 2019, an estimated 1 335 100 new cancer cases and 397 583 cancer-related deaths occurred among AYAs worldwide. While the incidence rate increased mildly, the death rate decreased significantly between 1990 and 2019, with an estimated annual percentage change of 0.38 (95% confidence interval 0.36-0.39) and −0.93 (95% confidence interval −0.95 to −0.92), respectively. The cancer burden was disproportionally greater among women than among men. The cancer profiles varied substantially across geographical regions, with the highest burden being in South Asia and East Asia. Besides, the cancer incidence in the high SDI regions was four times higher than that in the low SDI regions; however, the mortality burden in the high SDI region was lower than that in the low SDI region, which reflected the differences in cancer profiles across SDI regions and the inferior outcomes in the low SDI regions.

Conclusion

This study updates the previous epidemiological data of the cancer burden of AYAs. The cancer burden in AYAs varied substantially according to age, sex, SDI, and geographical regions. These findings highlight that the specific cancer profile of AYA patients requires targeted cancer control measures to reduce the cancer burden in this age group.

•

The cancer burden in AYAs varied substantially according to age, sex, SDI, and geographical regions.

•

Cancer burden in AYAs was disproportionally greater among women than among men.

•

Cancer profiles of AYAs varied across different geographical regions and SDI regions.

•

Cancer burden in AYAs was still considerable in the low SDI regions.

[Comparison of three rotary file systems for removal of Enterococcus faecalis from infected root canals]

OBJECTIVE

To compare the efficacy of a novel rotary file system (EZ Pass) with two well-established rotary file systems(ProTaper Gold and ProTaper Next)for removal of Enterococcus faecalis from infected root canals in extracted maxillary central incisors.

METHODS

Models of root canal infection with Enterococcus faecalis were constructed in 51 extracted singlerooted maxillary central incisors.One of the incisor model with infected root canal was demineralized, sectioned, and stained with Brown & Brenn technique for microscopic observation; The remaining 50 models were randomly divided into 5 groups(n=10) for treatment with EZ Pass, ProTaper Gold, ProTaper Next, 0.9% NaCl or 2% NaOCl.Samples were collected from the infected root canals before and after the treatments to assess the percent reduction and logarithmic reduction value of CFU in the root canals.

RESULTS

The incisors with root canal infection by Enterococcus faecalis showed obvious biofilms on the surface of the root canals and massive bacterial invasion deep into the dentinal tubules, with a maximum invasion depth of about 475 μm.The percent reduction of the CFU did not differ significantly after treatments with EZ Pass, ProTaper Gold, ProTaper Next and 2% NaOCl (P > 0.05), but all these treatments resulted in significantly greater reduction than 0.9% NaCl (P < 0.01).The logarithmic reduction of CFU were comparable after treatments with EZ Pass (1.47±0.12), ProTaper Gold (1.74±0.14) and ProTaper Next (1.63±0.17;P > 0.05).

CONCLUSION

EZ Pass can significantly reduce the bacterial load in infected root canals with an equivalent bacterial elimination capacity to ProTaper Gold and ProTaper Next.

Odderon Exchange from Elastic Scattering Differences between pp and pp[over ¯] Data at 1.96 TeV and from pp Forward Scattering Measurements

We describe an analysis comparing the pp[over ¯] elastic cross section as measured by the D0 Collaboration at a center-of-mass energy of 1.96 TeV to that in pp collisions as measured by the TOTEM Collaboration at 2.76, 7, 8, and 13 TeV using a model-independent approach. The TOTEM cross sections, extrapolated to a center-of-mass energy of sqrt[s]=1.96  TeV, are compared with the D0 measurement in the region of the diffractive minimum and the second maximum of the pp cross section. The two data sets disagree at the 3.4σ level and thus provide evidence for the t-channel exchange of a colorless, C-odd gluonic compound, also known as the odderon. We combine these results with a TOTEM analysis of the same C-odd exchange based on the total cross section and the ratio of the real to imaginary parts of the forward elastic strong interaction scattering amplitude in pp scattering for which the significance is between 3.4σ and 4.6σ. The combined significance is larger than 5σ and is interpreted as the first observation of the exchange of a colorless, C-odd gluonic compound.

POS1084 COMPARISON OF NUMERICAL RATING SCALE (NRS) AND VISUAL ANALOGUE SCALE (VAS) IN THE PATIENT REPORTED OUTCOME MEASURES OF 3VAS AND 4VAS IN PSORIATIC ARTHRITIS

Background:

There is a recognised need for a feasible continuous composite measure in routine clinical care for psoriatic arthritis (PsA). Two multidimensional composite Visual Analogue Scales (VAS) have been proposed; the 3 and 4VAS1, but there may be some advantages to using a numerical rating scale (NRS) over VAS in patient reported outcomes. VAS is a 100mm horizontal line, and the NRS a 21-point scale ranging from 0 to 10 in increments of 0.5. NRS are simple and faster to score, less susceptible to measurement error and may reduce the floor and ceiling effects, whereby patients avoid using the extremes of the scale. A previous study has demonstrated good agreement between VAS and NRS for the separate patient reported outcome measures in PsA, which correlate with disease severity and life impact.2

Objectives:

To test the performance of NRS, compared with VAS, in the composite 3 and 4VAS scores.

Methods:

Data were collected prospectively across three UK hospital trusts from 2018-2019, as part of a study assessing the use of NRS in patient reported outcome measures in PsA.2 Patients completed the VAS and NRS for pain, arthritis, skin psoriasis, and global disease activity. The 3 VAS comprises of a physician global VAS, patient global VAS and patient skin VAS and the 4 VAS comprises of the physician global VAS, patient pain VAS, joint VAS and skin VAS. NRS and VAS versions of the patient reported measures were tested. Physician global scores were not available from the study data, therefore only the patient reported components are included. Agreement between the scales was assessed using the intraclass correlation coefficients (ICCs), with a two-way mixed absolute agreement model, and Bland-Altman plots. Spearman’s rank correlation coefficients were used to assess dependency between scale scores and clinical parameters including tender and swollen joint count, PsAID12 and HAQDI.

Results:

Data from 209 patients were analysed. 60.0% were male, with mean age of 51.7 years and median PsA duration of 7.0 years. Mean 3VAS score was 3.57 and the mean NRS-3VAS was 3.79, with ICC 0.98 (95% CI 0.96-0.98). Mean 4VAS was 3.71 and NRS-4VAS was 3.90 with ICC 0.98 (95% CI 0.97-0.98). Average NRS scores were slightly higher than VAS scores. The Bland-Altman plots comparing NRS and VAS for the patient-reported components of 3VAS and 4VAS are demonstrated in Figure 1. 64.1% patients reported a preference for NRS over VAS. Correlation of the 3/4VAS with PSAID, HAQ and joints counts are reported in Table 1. Visual representation of the NRS and VAS scales for 3VAS and 4VAS as histograms demonstrated that there is marginally less floor effect using NRS compared to VAS.

Conclusion:

There is good agreement between VAS and NRS for the patient-reported components of 3VAS and 4VAS, supporting that VAS scores are reproducible as NRS scores. Both NRS and VAS versions of the 3 and 4VAS scales correlate with disease activity and life impact.2 There may be advantages in testing the 3/4VAS as NRS moving forward.

References:

[1]Tillett W et al. J Rheumatol. 2021; in press

[2]Ye W et al. J Rheumatol. 2020 Dec 1:jrheum.200928.

Table 1.

Spearman’s correlations of the 3 and 4 VAS scores with TJC, SJC, PsAID and HAQ

Patient ReportedTJCSJCPsAIDHAQDI without aids3 VAS vas0.510.440.880.624 VAS vas0.540.470.890.653 VAS nrs0.490.430.890.634 VAS nrs0.530.460.920.67

Key: 3VAS; Patient global and skin VAS, 4 VAS: Patient pain, joint and skin VAS. 3 and 4 NRS; Numeric Rating Scale (NRS). TJC/ SJC: Tender/Swollen Joint count. PSAID: Psoriatic Arthritis Impact of Disease. HAQDI: Stanford Heath Assessment Questionnaire.

Acknowledgements:

Dr Day and Dr Ye contributed equally to the development of this abstract.

Disclosure of Interests:

Julia Day: None declared, Weiyu Ye: None declared, William Tillett Speakers bureau: AbbVie, Amgen, Celgene, Lilly, Janssen, Novartis, Pfizer Inc., and UCB, Consultant of: AbbVie, Amgen, Celgene, Lilly, Janssen, Novartis, MSD, Pfizer Inc., and UCB, Grant/research support from: AbbVie, Celgene, Eli Lilly, Janssen and UCB, Laura C Coates Speakers bureau: AbbVie, Amgen, Biogen, Celgene, Gilead, Eli Lilly, Janssen, Medac, Novartis, Pfizer, and UCB., Consultant of: AbbVie, Amgen, Boehringer Ingelheim, Bristol-Myers Squibb, Celgene, Eli Lilly, Gilead, Janssen, Novartis, Pfizer, and UCB;, Grant/research support from: AbbVie, Amgen, Celgene, Eli Lilly, Pfizer, and Novartis.

Group-Targeting SERS Screening of Total Benzodiazepines Based on Large-Size (111) Faceted Silver Nanosheets Decorated with Zinc Oxide Nanoparticles

Rapid, quantitative, and group-targeting detection of total benzodiazepines (BZDs) is critical to create an accurate judgement in emergent medical and forensic settings. Large-size (111) faceted Ag nanosheets decorated with small ZnO nanoparticles were designed as the prominent surface-enhanced Raman scattering substrate, which possessed advantages of specific metal facets and additional charge-transfer (CT) effect from the semiconductor. The vital and bridge role of ZnO in the CT effect was systematically studied via experimental investigations and molecular dynamics simulation, which proves the essentiality of an appropriate ZnO decoration density. Upon determining optimal Ag NS/ZnO hybrids, a calibration curve of estazolam was established with a 0.5 nM detection limit. Based on the obtained curve, group-targeting screening was achieved toward total concentrations of five BZDs (estazolam, oxazepam, alprazolam, triazolam, and lorazepam). Importantly, the total concentrations of BZDs in mice serum were accurately monitored with changing analytical time during the metabolic process, which was in agreement with the tendency measured by liquid chromatography with tandem mass spectrometry.

Mixed-reality hologram for diagnosis and surgical planning of double outlet of the right ventricle: a pilot study

AIM

To evaluate the mixed-reality (MR) hologram, a novel technology based on two-dimensional images, which simulates three-dimensional (3D) images and provides a dynamic and interactive alternative, for its usefulness in the diagnosis and surgical planning of double outlet of the right ventricle (DORV).

MATERIALS AND METHODS

Thirty-four patients who were suspected of DORV based on ultrasound findings underwent cardiac computed tomography angiography (CTA). The patients were assigned randomly to the MR holographic guidance (MRHG) group or the control group. For the patients in the MRHG group, the CTA images were converted into Standard Template Library (STL) files after segmentation, 3D reconstruction, colourisation, and transparentisation, and then exported for MR holographic visualisation. The CTA images of the patients in the control group were analysed using routine 3D reconstruction only. Diagnostic accuracy and surgical planning were compared between the two groups based on visualisation at surgery.

RESULTS

In the MRHG group, the 3D hologram observation was in concordance with the actual anatomical findings, and the DORV type was classified accurately in all patients. The diagnostic accuracy for the malformation was 95.5% in the MRHG group and 89.7% in the control group, but the difference was not significant (p=0.3). All the procedures were exactly the same as planned based on the 3D MR holographic model. The surgical planning time was shorter for the MRHG group (51.65 ± 11.11 min) than that for the control group (65.71 ± 18.07 min, p<0.05).

CONCLUSION

MR 3D holograms may provide a clear and deeper anatomical perception of DORV and improve surgical planning.

The influence of angioplasty balloon sizing on acute post-procedural outcomes: a Finite Element Analysis

Atherosclerosis is one of the most common vascular pathologies in the world. Among the most commonly performed endovascular treatments, percutaneous transluminal angioplasty (PTA) has been showing significantly positive clinical outcomes. Due to the complex geometries, material properties and interactions that characterize PTA procedures, finite element analyses of acute angioplasty balloon deployment are limited. In this work, finite element method (FEM) was used to simulate the inflation and deflation of a semi-compliant balloon within the 3D model of a stenosed artery with two different plaque types (lipid and calcified). Self-defined constitutive models for the balloon and the plaque were developed based on experimental and literature data respectively. Balloon deployment was simulated at three different inflation pressures (10, 12 and 14 atm) within the two plaque types. Balloon sizing influence on the arterial elastic recoil obtained immediately after PTA was then investigated. The simulated results show that calcified plaques may lead to higher elastic recoil ratios compared to lipid stenosis, when the same balloon inflation pressures are applied. Also, elastic recoil increases for higher balloon inflation pressure independent of the plaque type. These findings open the way for a data-driven assessment of angioplasty balloon sizing selection and clinical procedures optimization.Clinical Relevance- The FE model developed in this work aims at providing quantitative evaluation of recoil after balloon angioplasty. It may be useful for both manufacturers and clinicians to improve efficiency of angioplasty balloon device design and sizing selection with respect to plaque geometry and constitution, consequently enhancing clinical outcomes.

Silver mirror films deposited on well plates for SERS detection of multi-analytes: Aiming at 96-well technology

96-Well technology is associated with automated sample preparation and simultaneous analysis based on the low-cost well plate format. To explore the potential applications of 96-well technology in SERS detection, we examined the surface-bound electroless deposition procedure for the preparation of uniform and stable Ag mirror films on polydopamine (PDA)-coated well plates as active-SERS substrates. In the presented procedure, small Ag seeds assembled on PDA coating were employed as the surface-bound catalyst and provided the active sites for electroless Ag deposition. The high-quality Ag mirror films showed high performance in terms of sensitivity, uniformity, reproducibility and stability using rhodamine 6G (R6G) as the probe molecule. A remarkable enhancement factor of 3.41 × 10⁸ was obtained. The relative standard deviations against well-by-well and batch-by-batch reproducibility were less than 5%. The SERS films on well plates were successfully used to quantify the amounts of organic dyes (R6G and malachite green) in environmental water samples and small biological molecules (adenosine triphosphate and adenine) in urine matrix, displaying satisfactory sensitivity, selectivity and recovery. Their limit of detection values were at nanomolar, even picomolar concentration.

Liquid biopsy assay for lung carcinoma using centrifuged supernatants from fine-needle aspiration specimens

INTRODUCTION

Tumor mutation profiling is standard-of-care in lung carcinoma patients. However, comprehensive molecular profiling of small specimens, including core needle biopsy (CNB) and fine-needle aspiration (FNA) specimens, may often be inadequate due to limited tissue. Centrifuged FNA supernatants, which are typically discarded, have emerged recently as a novel liquid-based biopsy for molecular testing. In this study, we evaluate the use of lung carcinoma FNA supernatants for detecting clinically relevant mutations.

METHODS

Supernatants from lung carcinoma FNA samples (n = 150) were evaluated. Samples were further analyzed using next-generation sequencing (NGS) and ultrasensitive droplet digital PCR (ddPCR). Mutation profiles in a subset of samples were compared with results derived from paired tissue samples from the same patient (n = 67) and available plasma liquid biopsy assay (n = 45).

RESULTS

All 150 samples yielded adequate DNA and NGS were carried out successfully on 104 (90%) of 116 selected samples. Somatic mutations were detected in 82% of the samples and in 50% of these patients a clinically relevant mutation was identified that would qualify them for targeted therapy or a clinical trial. There was high overall concordance between the mutation profiles of supernatants and the corresponding tissue samples, with 100% concordance with concurrent FNA and 96% with concurrent CNB samples. Comparison of actionable driver mutations detected in supernatant versus plasma samples showed 84% concordance.

CONCLUSIONS

FNA supernatants can provide a valuable specimen source for genotyping lung carcinoma especially in patients with insufficient tumor tissue, thereby reducing multigene mutation profiling failure rates, improving turnaround times, and avoiding repeat biopsies.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Antidiabetics, statins and the risk of amyotrophic lateral sclerosis

BACKGROUND

Medications that are used for treatment of metabolic disorders have been suggested to be associated with the development of amyotrophic lateral sclerosis (ALS).

METHODS

To examine the associations of antidiabetics and statins with the subsequent risk of ALS we conducted a population-based nested case-control study of 2475 Swedish residents diagnosed with ALS during July 2006 to December 2013 and 12 375 population controls (five for each ALS case). We extracted information on filled prescriptions of antidiabetics and statins for both cases and controls from the Swedish Prescribed Drug Register during the years before ALS diagnosis. Conditional logistic regression was used to calculate odds ratios (ORs) for the associations of these medications with ALS risk.

RESULTS

Patients with ALS were less likely to have been prescribed with antidiabetics compared with controls [OR, 0.76; 95% confidence intervals (CI), 0.65-0.90]. Conversely, statins were not associated with ALS risk overall (OR, 1.08; 95% CI, 0.98-1.19), although a positive association was noted among women (OR, 1.28; 95% CI, 1.10-1.48). The latter association was mostly explained by ALS cases being more likely to have a first prescription of statins during the year before diagnosis compared with controls (OR, 2.54; 95% CI, 1.84-3.49).

CONCLUSIONS

The inverse association of antidiabetics with ALS is consistent with the previously reported inverse association between type 2 diabetes and ALS risk. The increase in prescription of statins during the year before ALS diagnosis deserves attention because it might reflect an acceleration of the course of ALS due to statin use.

Dissociable dopaminergic and pavlovian influences in goal-trackers and sign-trackers on a model of compulsive checking in OCD

RATIONALE

Checking is a functional behaviour that provides information to guide behaviour. However, in obsessive-compulsive disorder (OCD), checking may escalate to dysfunctional levels. The processes underpinning the transition from functional to dysfunctional checking are unclear but may be associated with individual differences that support the development of maladaptive behaviour. We examined one such predisposition, sign-tracking to a pavlovian conditioned stimulus, which we previously found associated with dysfunctional checking. How sign-tracking interacts with another treatment with emerging translational validity for OCD-like checking, chronic administration of the dopamine D₂ receptor agonist quinpirole, is unknown.

OBJECTIVES

We tested how functional and dysfunctional checking in the rat observing response task (ORT) was affected by chronic quinpirole administration in non-autoshaped controls and autoshaped animals classified as sign-trackers or goal-trackers.

METHODS

Sign-trackers or goal-trackers were trained on the ORT before the effects of chronic quinpirole administration on checking were assessed. Subsequently, the effects on checking of different behavioural challenges, including reward omission and the use of unpredictable reinforcement schedules, were tested.

RESULTS

Prior autoshaping increased checking. Sign-trackers and goal-trackers responded differently to quinpirole sensitization, reward omission and reinforcement uncertainty. Sign-trackers showed greater elevations in dysfunctional checking, particularly during uncertainty. By contrast, goal-trackers predominantly increased functional checking responses, possibly in response to reduced discrimination accuracy in the absence of cues signalling which lever was currently active.

CONCLUSIONS

The results are discussed in terms of how pavlovian associations influence behaviour that becomes compulsive in OCD and how this may be dependent on striatal dopamine D₂ receptors.

First report of the sting nematode Belonolaimus longicaudatus infecting bermudagrass in Barbados

In 2016, "Tifdwarf" hybrid bermudagrass (Cynodon dactylon (L) Pers. × C. transvaalensis Burtt-Davy) grown on a golf green built to the United States Golf Association recommendations in Barbados started to show irregular significant chlorotic patches followed by gradual thinning and decline of turfgrass. A survey was conducted in May 2016 to determine the presence of plant-parasitic nematodes. The results revealed the presence of the plant-parasitic sting nematode Belonolaimus longicaudatus. To our knowledge, this is the first report of B. longicaudatus associated with bermudagrass in Barbados.

In 2016, “Tifdwarf” hybrid bermudagrass (Cynodon dactylon (L) Pers. × C. transvaalensis Burtt-Davy) grown on a golf green built to the United States Golf Association recommendations in Barbados started to show irregular significant chlorotic patches followed by gradual thinning and decline of turfgrass. A survey was conducted in May 2016 to determine the presence of plant-parasitic nematodes. The results revealed the presence of the plant-parasitic sting nematode Belonolaimus longicaudatus. To our knowledge, this is the first report of B. longicaudatus associated with bermudagrass in Barbados.

N-doped carbon coated Mn3O4/PdCu nanocomposite as a high-performance catalyst for 4-nitrophenol reduction

This paper reports the chemical synthesis of highly-active Mn₃O₄/PdCu nanocomposites coated with N-doped carbon (NC) shell using polydopamine (PDA) as the carbon source, which provides high specific surface area and pore volume. The structure and morphology of Mn₃O₄/PdCu@NC nanocomposites were systematically studied. Taking advantage of the synergistic effects of PdCu alloy and Mn₃O₄ support, the Mn₃O₄/PdCu@NC catalyst exhibited an outstanding activity toward the reduction of 4-nitrophenol (4-NP), in comparison to Mn₃O₄/PdM@NC (M = Ni, Au, Ag), Mn₃O₄/PdCu@PDA, and commercial Pd/C catalyst. Owing to the protection by NC shell, the as-prepared catalyst showed stable conversion efficiency of up to 90% over ten successive cycles. Considering 4-NP as one of the important organic pollutants from industrial production, the effects of various inorganic and organic species on the catalytic efficiency were further tested and most of them had negligible impact. This strategy of utilizing an N-doped carbon shell could be extended to obtain PdCu alloys supported on other metal oxides, making it applicable for applications in treatment of environmental pollutants.

Multi-hydrogen bond assisted SERS detection of adenine based on multifunctional graphene oxide/poly (diallyldimethyl ammonium chloride)/Ag nanocomposites

Nanocomposites of graphene oxide/poly (diallyldimethyl ammonium chloride)/Ag nanoparticles (GO/PDDA/Ag NPs) were constructed via a self-assembly process as a surface-enhanced Raman scattering (SERS) substrate, in which functional macromolecules PDDA were utilized to load GO and support Ag NPs. Fundamental SERS performance of this SERS substrate was evaluated using rhodamine 6G (R6G), which displayed excellent enhancement effect, transferable nature and high stability of the synthesized GO/PDDA/Ag NPs substrate. Furthermore, the synthesized SERS substrate was employed in the sensitive detection of adenine with a linear range of 0.05-1000 μM and low detection limit of 1 nM. Other than the large surface area of GO, multiple-hydrogen bond interactions between adenine and the modified PDDA were another important factor in capturing adenine molecules and enhancing SERS signal. The hydrogen bond interaction was calculated using quantum mechanical calculations. Moreover, determination of adenine in aqueous solutions was achieved with good anti-interference ability against other nucleic bases with similar structures, such as guanine, cytosine and thymine. Therefore, GO/PDDA/Ag can be anticipated to be a potential substrate for label-free, fast and sensitive SERS detection of adenine in the field of bioanalysis.