Solution-phase sample-averaged single-particle spectroscopy of quantum emitters with femtosecond resolution

The development of many quantum optical technologies depends on the availability of single quantum emitters with near-perfect coherence. Systematic improvement is limited by a lack of understanding of the microscopic energy flow at the single-emitter level and ultrafast timescales. Here we utilize a combination of fluorescence correlation spectroscopy and ultrafast spectroscopy to capture the sample-averaged dynamics of defects with single-particle sensitivity. We employ this approach to study heterogeneous emitters in two-dimensional hexagonal boron nitride. From milliseconds to nanoseconds, the translational, shelving, rotational and antibunching features are disentangled in time, which quantifies the normalized two-photon emission quantum yield. Leveraging the femtosecond resolution of this technique, we visualize electron-phonon coupling and discover the acceleration of polaronic formation on multi-electron excitation. Corroborated with theory, this translates to the photon fidelity characterization of cascaded emission efficiency and decoherence time. Our work provides a framework for ultrafast spectroscopy in heterogeneous emitters, opening new avenues of extreme-scale characterization for quantum applications.

[Study of the predictive role of serum HBV RNA on HBeAg serological conversion in children with chronic hepatitis B]

Objective: To investigate the role of serum hepatitis B virus RNA (HBV RNA) in predicting HBeAg serological conversion in children with chronic hepatitis B. Methods: 175 children aged 1~17 years with chronic hepatitis B who received interferon α (IFNα) for 48 weeks were selected. Patients were divided into HBeAg seroconversion and non-conversion based on whether HBeAg seroconversion occurred at 48 weeks of treatment.T-test and Mann-Whitney U test were used to compare between groups; chisquare test or Fisher exact probability method was used to compare the frequency between groups of classified variables; and Pearson correlation was used to analyze the correlation between indicators. Univariate and multivariate logistic regression analyses were used to identify influencing factors associated with HBeAg serological conversion. The predictive effect of HBV RNA, HBV DNA, and HBsAg on HBeAg serological conversion was compared and analyzed by the receiver operating characteristic curve (ROC). Results: The seroconversion rate of HBeAg at 48 weeks was 36.0% (63/175). The reduction in HBVRNA levels from baseline to the 12th, 24th, 36th, and 48th weeks of antiviral therapy was significantly greater in the HBeAg serological conversion group than that in the non-conversion group, and the difference was statistically significant between the two groups (P < 0.05). Univariate and multivariate regression analyses showed that age and a decline in HBV RNA levels at week 12 were independent predictors of HBeAg serological conversion. The area under the ROC curve (AUROC) of HBV RNA decline at week 12 was 0.677(95% CI∶0.549-0.806, P = 0.012), which was significantly better than the same period of AUROC of HBV DNA (0.657, 95% CI∶0.527-0.788, P = 0.025) and HBsAg (0.660, 95% CI∶0.526-0.795, P = 0.023) decline. HBV RNA levels decreased (>1.385 log10 copies/ml) at week 12, with a positive predictive value of 53.2%, a negative predictive value of 72.2%, a sensitivity of 77.4%, and a specificity of 57.9% for HBeAg seroconversion. Conclusion: HBV RNA level lowering during the 12th week of antiviral therapy can serve as an early predictor marker for HBeAg serological conversion in children with chronic hepatitis B.

Enhancement Patterns of Metastatic Intrahepatic Cholangiocarcinoma and Outcomes after Chemotherapy and Radiation

PURPOSE/OBJECTIVE(S)

Patients with metastatic intrahepatic cholangiocarcinoma (M1-iCCA) have a poor prognosis with a 5-year survival rate of less than 20%. Definitive doses of radiation therapy (RT) after upfront chemotherapy (chemo/RT) in this patient population have shown to prolong survival by reducing the risk of tumor-related liver failure compared to chemotherapy alone. Our group has also identified a baseline radiographic feature, the arterial enhancement pattern, which has pathological and prognostic associations for iCCA. We tested the hypothesis that baseline arterial enhancement is independently associated with survival outcomes for patients who receive chemo/RT or chemo alone.

MATERIALS/METHODS

Patients with M1-iCCA from 2010 to 2021 were included in this retrospective study. Patients were grouped into those who underwent chemo alone and those who underwent chemo/RT. The inclusion criteria included confirmed diagnosis of M1-iCCA, availability of baseline multi-phasic computed tomography (CT), and follow-up for at least six months or until death. Tumor arterial enhancement patterns were categorized as previously described into hypovascular or hypervascular, where the tumors that were hypervascular had either peripheral enhancement or central enhancement. Mean tumor density in Hounsfield units was recorded for each patient. Survival was estimated using the Kaplan Meier method, and Cox proportional models were used to adjust for prognostic variables.

RESULTS

A total of 281 patients with iCCA were identified and 229 had evaluable CT scans. Demographic and baseline characteristics of patient groups are shown in the Table. On univariate analysis, patient age, ECOG performance status (PS) at diagnosis, treatment type, and arterial enhancement patterns associated with overall survival (OS). On multivariable analysis, the arterial enhancement pattern independently associated with OS after accounting for covariates. Patients with hypervascular tumors had prolonged OS compared to those with hypovascular tumors (HR = 0.72, [0.54 - 0.96], p = 0.02). Prolonged OS was also observed in the chemo/RT group compared to the chemo alone group (HR = 0.37, [0.25-0.54], p< 0.0001).

CONCLUSION

Baseline enhancement patterns of M1-iCCA were prognostic in the contexts of chemo alone and chemo/RT. This imaging-based biomarker may improve the ability to stratify patients for therapeutic management.

Compensating for gyroradius effects in beamlines with small Helmholtz coils

Measurements of lighter, low-energy charged particles in a laboratory beamline are complicated due to the influence of Earth's magnetic field. Rather than nulling out the Earth's magnetic field over the entire facility, we present a new way to correct particle trajectories using much more spatially limited Helmholtz coils. This approach is versatile and easy to incorporate in a wide range of facilities, including the existing ones, enabling measurements of low-energy charged particles in a laboratory beamline.

[Nontuberculous mycobacteria infection and pulmonary alveolar proteinosis in a patient with hematopoietic defects]

A 28-year-old male with a history of leukopenia was admitted with complaints of fever, cough, and dyspnea for 3 months. Initial work-up identified reduced circulating levels of granulocytes, monocytes, lymphocytes, and NK cells. Computed tomography revealed bilateral reticulonodular opacities and mediastinal lymph node enlargement. Peripheral blood culture and mediastinal lymph node aspiration yielded Mycobacterium avium. Genetic testing revealed a heterozygous germline GATA2 mutation (c.1187G>A, R396Q). Despite standard anti-mycobacterial therapy, the patient's dyspnea worsened and subsequent imaging studies revealed diffuse ground-glass opacification. A transbronchial lung biopsy confirmed the development of pulmonary alveolar proteinosis. Bone marrow transplantation had not been performed due to the unavailability of suitable donors. The disease progressed after whole lung lavage, and the patient died at the age of 31 years from respiratory failure. The current case report emphasized the importance of raising awareness about the rare GATA2 deficiency, which is characterized by hematologic abnormalities, primary immunodeficiency, and pulmonary alveolar proteinosis.

[Clinical and pathological features and differential diagnosis of fibro-osseous tumors and dysplasias]

Fibro-osseous lesions is a class of diseases with obvious similarities in clinical manifestations and pathological features, which has been attracting the attention of clinicians and pathologists. The latest WHO 2022 Classification (5th edition) included six of these diseases (cemento-osseous dysplasia, segmental odontomaxillary dysplasia, fibrous dysplasia, juvenile trabecular ossifying fibroma, psammomatoid ossifying fibroma and familial gigantiform cementoma) in the " fibro-osseous tumours and dysplasias ", and put forward new ideas on the diagnosis and treatment of these diseases. According to the latest WHO 2022 Classification (5th edition), the clinical and pathological features, diagnosis and differential diagnosis of these six diseases were described.

[Research progress of tunneling nanotube in bone biology]

Tunneling nanotube (TNT) is a newly discovered communication mode between animal cells in recent years, which have important physiological and pathological significance. However, the role of TNT in bone biology is still unclear. At present, there are many reports about tunneling nanotubes in bone marrow mesenchymal stem cells, osteoclast precursor cells, osteoblasts and immune cells. This review describes the research advances of TNT and its research progress in bone biology. It looks forward to the research direction of TNT in oral and maxillofacial bone development and bone biology, to provide new strategies for the maintenance of bone homeostasis and the treatment of bone diseases.

Response of sugar metabolism in the cotyledons and roots of Ricinus communis subjected to salt stress

Ricinus communis is an important oilseed crop worldwide and is also considered one of the best potential plants for salt-affected soil improvement in northeast China. However, little is known about photosynthesis and carbohydrate metabolism in this plant, nor the distribution of carbohydrates in cotyledons and roots under salinity stress. In the present study, seedling growth, gas exchange parameters (P_N , E, g_s and C_i ), carbohydrate (fructose, sucrose, glucose, soluble sugar and starch) metabolism and related enzymes and genes were measured in Ricinus plants. Under salt stress, P_N of cotyledons decreased significantly (P < 0.05), resulting in weak photosynthetic capacity. Furthermore, salt stress increased sucrose and glucose content in cotyledons, but decreased soluble sugar and starch content. However, sucrose increased and starch decreased in roots. This may be correlated with the increasing sugar metabolism under salinity, including notable changes in sugar-related enzyme activities (SPS, SuSy, α-amylase and β-amylase) and gene expression of RcINV, RcSUS, RcAmY, RcBAM and RcGBE1. The results suggest that salinity reduces photosynthesis of cotyledons, alters carbohydrate allocation between cotyledons and roots and also promotes starch utilization in cotyledons and starch biosynthesis in roots, leading to a functional imbalance between cotyledons and roots. Together, these findings provide insights into the crucial role of sugar metabolism in improving salt-tolerance of Ricinus during the early seedling growth stage.

Relationship between Social Support, Sarcopenia, and Cognitive Impairment in Chinese Community-Dwelling Older Adults

BACKGROUND

Cognitive impairment and sarcopenia have become important challenges for the growing aging population. Social support has been shown to protect against cognitive impairment, but its impact on sarcopenia remains unknown. The purpose of this study was to explore the correlation between social support, sarcopenia, and cognitive impairment in Chinese older adults.

METHOD

A multi-stage whole group sampling method was used to conduct a cross-sectional survey of 720 community-dwelling older people in Shanghai. The definition of sarcopenia was in accordance with the criteria of the Asian Working Group for Sarcopenia (AWGS) 2019. Cognitive impairment was evaluated using a computerized neuropsychological assessment device that had been previously validated. Social support was assessed using the Social Support Rate Scale. Logistic regression analyses were conducted to explore the relationship between social support cognitive impairment and sarcopenia, fully adjusting for all potential confounding factors.

RESULTS

Our study found that 230 (31.94%) of the participants had cognitive impairment and 97 (13.47%) of the participants had sarcopenia. The mean social support score was 35.10 ± 7.54. Besides, the results showed that cognitive impairment was associated with sarcopenia (OR:1.650, 95% CI: 1.048, 2.596, P=0.030) after adjusting for confounding factors. Older adults with high level social support had the lowest risk of cognitive impairment (OR: 0.297, 95% CI: 0.115, 0.680, P=0.021) and sarcopenia (OR: 0.113, 95% CI: 0.031, 0.407, P=0.001), respectively.

CONCLUSION

Our analysis revealed that high level social support was negatively associated with sarcopenia and cognitive impairment. These findings provide strong support for the health promotion effect of social networks against sarcopenia and cognitive impairment in Chinese community-dwelling older adults, with important implications for healthcare policy makers.

[Changes of the World Health Organization 2022 classification (5th edition) of salivary glands tumors]

Pathological diagnosis of salivary gland tumors is one of the most challenging areas in all head and neck surgical pathology. The classification of salivary gland tumors was updated in the 5th edition of the World Health Organization Classification of Head and Neck Tumours, most of which were based on their molecular pathological characteristerics. This new classification features a description of several new entitiesamong benign and malignant neoplasms, salivary gland tumors with updated naming or diagnostic criteria, and lesions deleted from this section, etc.This present review focuses on the updates and changes in the new classification of salivary gland tumors, and provides some reference for head and neck surgeons and pathologists.

Activation of PI3K/Akt prevents hypoxia/reoxygenation-induced GnRH decline via FOXO3a

Recent studies have suggested that the hypothalamus has an important role in aging by regulating nuclear factor-κB (NF-κB)-directed gonadotropin-releasing hormone (GnRH) decline. Moreover, our previous study has shown that ischemia-reperfusion (IR) injury activates NF-κB to reduce hypothalamic GnRH release, thus suggesting that IR injury may facilitate hypothalamic programming of system aging. In this study, we further examined the role of phosphoinositide 3-kinase (PI3K)/Protein kinase B (Akt) pathway, a critical intracellular signal pathway involved in the repair process after IR, in hypoxia-reoxygenation (HR)-associated GnRH decline in vitro. We used GT1-7 cells and primarily-cultured mouse GnRH neurons as cell models for investigation. Our data revealed that the activation of the PI3K/Akt/Forkhead box protein O3a (FOXO3a) pathway protects GnRH neurons from HR-induced GnRH decline by preventing HR-induced gnrh1 gene inhibition and NF-κB activation. Our results further the understanding of the regulatory mechanisms of HR-associated hypothalamic GnRH decline.

OP0113 FUNCTIONAL GENOMICS IN PRIMARY T CELLS AND MONOCYTES IDENTIFIES MECHANISMS BY WHICH GENETIC SUSCEPTIBILITY LOCI INFLUENCE SYSTEMIC SCLEROSIS RISK

Background

Systemic sclerosis (SSc) is a complex autoimmune disease with a strong genetic component. However, the underlying mechanism by which genetics increase disease risk is still unknown. The most recent GWAS studies have identified 27 independent signals associated to SSc [1]. However, the majority of these signals affect regulatory elements that can regulate genes often located hundreds of kilobases away.

The challenge in the post-GWAS era is to use functional genomics to translate genetic findings into patients’ benefit, particularly in disease-relevant cell types.

Objectives

In this study we use chromatin conformation and gene expression analysis in patient derived primary cells and healthy individuals to assess potential mechanisms by which GWAS variants increase disease risk. We identify the potentially affected genes in a cell type specific manner and potential drug targets already in use or with potential for re-purposing.

Methods

Promoter capture Hi-C (pCHi-C) and RNA sequencing experiments were performed in a total of 15 CD4+ T cells and CD14+ monocytes samples each isolated from peripheral blood from SSc patients and healthy controls. We linked SSc-associated variants with their target genes and performed differential expression and differential interaction analyses between both cell types. Potential drug targets were identified using a protein-protein interaction model and queried against the OpenTargets database.

Results

We linked SSc-associated loci to 39 new potential target genes, confirming 7 previously assigned genes. We highlight novel causal genes, such as CXCR5 as the most probable candidate gene for the DDX6 locus (Figure 1). We confirm some previously linked SSc genes such as IRF8, STAT4, or CD247 which interestingly showed cell type specific interactions. We also identified 15 potential drug targets already in use in other similar immune-mediated diseases that could be repurposed for SSc treatment. Furthermore, we observed that interactions are directly related with the expression of important genes implicated in cell type specific pathways.

Figure 1.

Promoter Capture Hi-C interactions linking the DDX6 GWAS loci with the promoter of CXCR5 in CD4+ T cells and CD14+ monocytes. CD4+ T cells show significantly stronger interactions as well as CXCR5 gene expression.

Conclusion

Our study reveals potential causal genes for SSc-associated loci, some of them acting in a cell type specific manner, suggesting novel drug targets and biological mechanisms that may mediate SSc pathogenesis.

References

[1]López-Isac E, Acosta-Herrera M, Kerick M, et al (2019) GWAS for systemic sclerosis identifies multiple risk loci and highlights fibrotic and vasculopathy pathways. Nat Commun 10:. https://doi.org/10.1038/s41467-019-12760-y

Acknowledgements

This work was supported by the Spanish Ministry of Science and Innovation (grants RTI2018101332-B-100 and SAF2015-66761-P), the Cooperative Research Thematic Network (RETICS) programme (RD16/0012/0013) (RIER) from Instituto de Salud Carlos III (ISCIII, Spanish Ministry of Economy, Industry and Competitiveness), the Wellcome Trust (award references 207491/Z/17/Z and 215207/Z/19/Z), Versus Arthritis (award reference 21754), and the NIHR Manchester Biomedical Research Centre. DGS was supported by the Spanish Ministry of Economy and Competitiveness through the FPI programme (SAF2015-66761-P).

Disclosure of Interests

None declared

POS0035 GENE REGULATION IN T-CELLS FROM PsA PATIENTS DIFFERS BETWEEN PERIPHERAL BLOOD AND THE INFLAMED JOINTS: IMPLICATIONS FOR THE INTERPRETATION OF GWAS SIGNALS

Background

Genome-wide association studies (GWAS) have identified variants that are associated with complex diseases such as Psoriatic Arthritis (PsA). The majority of these variants do not affect the coding sequence of proteins but rather regulatory elements which are highly cell type and state specific, and can affect distally located genes via chromatin interaction mechanisms.

We and others have previously analysed GWAS loci for multiple conditions (including PsA and Rheumatoid Arthrtitis) in cell lines using functional genomics techniques, providing putative mechanisms to many loci with previously unknown function [1].

However, multiple studies have identified large differences in gene regulatory mechanisms between cell lines and primary cells, which could significantly alter the proposed mechanisms. Differences between between samples from healthy volunteers and patients, in particular from the affected tissue, have although not been exhaustively investigated.

Objectives

To assess the impact of using primary cells derived from PsA patients compared to healthy volunteers in functional genomics studies.

Methods

CD4+ and CD8+ T cells were isolated from peripherial blood from 10 healthy controls and 48 PsA patients and from 6 PsA synovial fluid samples.

We performed RNA-seq and ATAC-seq on these two cell types to analyse the global patterns of gene expression and chromatin activity.

Results

We find subtle differences between PsA patients and healthy controls in cells isolated from blood. RNA-seq analysis identified only a handful of differentially expressed genes whilst ATAC-seq analysis identified only 28 differential loci.

On the other hand, T cells isolated from synovial fluid showed significant differences compared to T cells isolated from patient’s blood. Interestingly, we find that CD4+ T cells show substantially more differentially expressed genes compared to CD8+ T cells (1168 vs 346 Log2FoldChange > 1, FDR < 0.01). Genes overexpressed in synovial CD4+ T cells are more strongly enriched for immune pathways such as cytokine signaling and T cell proliferation compared to synovial CD8+ T cells

We also find that synovial CD4+ T cells highly overexpress MHC class II genes (Figure 1).

Figure 1.

Normalized counts of the alpha chains of MHC class 2 genes in CD4+ and CD8+ T cells purified from blood from healthy subjects and patients and synovial fluid.

Conclusion

This preliminary analysis suggests that T cells isolated from peripherial blood do not seem to differ significantly between PsA patients and healthy controls. In contrast, cells isolated from synovial fluid are highly specialized and activated. Moreover, these cells do not resemble canonically activated T cells which means that this state can not be easily emulated in vitro.

This study indicates the importance of not only studying GWAS loci in relevant primary cells from patients, but also that attention needs to be given to cells isolated from the affected site.

References

[1]Shi C, Ray-Jones H, Ding J, et al (2021) Chromatin Looping Links Target Genes with Genetic Risk Loci for Dermatological Traits. J Invest Dermatol 141:1975–1984. https://doi.org/10.1016/J.JID.2021.01.015

Acknowledgements

This work was funded by the Wellcome Trust (award references 207491/Z/17/Z and 215207/Z/19/Z), the Versus Arthritis (award reference 21754), the NIHR Manchester Biomedical Research Centre, and the Medical Research Council (award reference MR/N00017X/1).

Disclosure of Interests

None declared

OP0222 IDENTIFICATION OF CAUSAL GENES AND MECHANISMS BY WHICH GENETIC VARIATION MEDIATES JUVENILE IDIOPATHIC ARTHRITIS SUSCEPTIBILITY USING FUNCTIONAL GENOMICS AND CRISPR-CAS9

Background

We recently performed the largest juvenile idiopathic arthritis (JIA) genome-wide association study (GWAS) to date 1. Disease-associated loci contain multiple single nucleotide polymorphism (SNPs), and the majority map to non-coding enhancers, making it challenging to define causal variants and genes.

Functional genomics datasets in disease-relevant tissues have shown to be essential for the functional interpretation of GWAS loci. In particular, capture Hi-C (CHi-C) has been successful in detecting chromosomal interactions linking GWAS loci to their target genes. However, such datasets are lacking in JIA.

Objectives

The aim of this study is to bridge this gap and advance the knowledge of the biological mechanisms that underpin susceptibility to JIA, by integrating GWAS with public epigenomics datasets and in-house generated CHi-C from JIA patients. We focus on CD4+ T-cells, which have been shown to be one of the most relevant cell types in JIA. In addition, we use CRISPR-Cas9 to validate the regulatory effect of prioritised variants on their predicted target genes.

Methods

Credible SNP sets for the top JIA risk loci (P < 5x10-6) were annotated using EpiMap data 2. Low input whole genome promoter CHi-C (PCHi-C) was performed on CD4+ T-cells isolated from blood from 3 JIA oligoarthritis patients, and data was analysed using CHiCAGO 3. GWAS and PCHi-C data were combined to prioritise causal genes using the Capture Hi-C Omnibus Gene Score (COGS) pipeline 4. We subsequently employed CRISPR activation (CRISPRa) and CRISPR interference (CRISPRi) in Jurkats to assess whether prioritized JIA variants were capable of regulating the expression of the interacting genes.

Results

614 credible SNPs (out of 735) were found to overlap active enhancers in CD4+ T-cells, and were prioritized for further analysis.

We identified numerous significant chromatin interactions in 19 out of 44 non-MHC JIA associated loci, linking JIA SNPs mapping to T-cell enhancers to a total of 61 target genes and revealing potential novel disease pathways. Moreover, COGS prioritised a total of 7 genes (RGS14, ERAP2, HIPK1, CCR4, CCRL2, CCR2, CCR3).

A JIA associated locus on chromosome 3 contains 39 SNPs. It maps to an intergenic region and the causal gene/s are unclear. Our PCHi-C data revealed that this JIA locus presents chromatin interactions with the promoters of several genes, such as CCRL2, CCR2, CCR3 and CCR5, three of which were prioritised by COGS. Two variants were selected for further analysis: rs79815064, which had the highest posterior probability, and rs8005404,the only variant within a CD4+ T-cell enhancer linked to surrounding gene activity.

When both SNPs were targeted with CRISPRa and CRISPRi, we observed an increased and decreased expression, respectively, of CCRL2, CCR2, CCR3 and CCR5, confirming their role in disease. These genes belong to the chemokine receptor family and are important regulators of the inflammatory response.

Conclusion

Our work shows how functional genomics can help identify biological mechanisms by which GWAS variants increase risk of JIA, which in turn will benefit patients through personalised medicine and the identification of therapeutic targets.

References

[1]López-Isac, E. et al. Combined genetic analysis of juvenile idiopathic arthritis clinical subtypes identifies novel risk loci, target genes and key regulatory mechanisms. Ann. Rheum. Dis.80, 321–328 (2021).

[2]Boix, C. A., James, B. T., Park, Y. P., Meuleman, W. & Kellis, M. Regulatory genomic circuitry of human disease loci by integrative epigenomics. Nat. 2021 5907845590, 300–307 (2021).

[3]Cairns, J. et al. CHiCAGO: Robust detection of DNA looping interactions in Capture Hi-C data. Genome Biol.17, 1–17 (2016).

[4]Javierre, B. M. et al. Lineage-Specific Genome Architecture Links Enhancers and Non-coding Disease Variants to Target Gene Promoters. Cell167, 1369 (2016).

Disclosure of Interests

Antonio Frantzesko: None declared, Valeriya Malysheva: None declared, Chenfu Shi: None declared, James Ding: None declared, John Bowes: None declared, Wendy Thomson: None declared, Stephen Eyre: None declared, Mikhail Spivakov Shareholder of: co-founder and shareholder of Enhanc3D Genomics Ltd, Gisela Orozco: None declared

A High Energy X-ray Diffraction Study of Amorphous Indomethacin

Amorphous pharmaceuticals often possess a wide range of molecular conformations and bonding arrangements. The x-ray pair distribution function (PDF) method is a powerful technique for the characterization of variations in both intra-molecular and inter-molecular packing arrangements. Here, the x-ray PDF of amorphous Indomethacin is shown to be particularly sensitive to the preferred orientations of the chlorobenzyl ring found in isomers in the crystalline state. In some cases, the chlorobenzyl ring has no preferred torsional angle in the amorphous form, while in others evidence of distinct isomer orientations are observed. Amorphous samples with no preferred torsion angles of the chlorobenzyl ring are found to favor enhanced inter-molecular hydrogen bonding, and this is reflected in the intensity of the first sharp diffraction peak. These significant variations in structure rule out amorphous Indomethacin as a possible standard for x-ray PDF measurements. At high humidity, time resolved PDF's for >40 h reveal water molecules forming hydrogen bonds with Indomethacin molecules. A simple linear hydrogen bond model indicates that water molecules in the wet amorphous form have similar hydrogen bond strengths to those found between Indomethacin dimers or chains in the dry amorphous form.

[Value of the application of enhanced CT radiomics and machine learning in preoperative prediction of microvascular invasion in hepatocellular carcinoma]

Objective: To explore the value of machine learning models in preoperative prediction of microvascular invasion (MVI) in hepatocellular carcinoma (HCC) based on dual-phase contrast-enhanced CT radiomics features. Methods: The data of 148 patients [106 males and 42 females, with an average age of (58±11) years] with HCC confirmed by pathology in the First Affiliated Hospital of Soochow University from January 2015 to May 2020 were retrospectively analyzed, including 88 cases of positive MVI and 60 cases of negative MVI. According to the ratio of 7∶3, the patients were randomly divided into the training and validation sets, respectively. The three-dimensional (3D) radiomics features of HCC in arterial phase (AP) and portal venous phase (PP) were extracted by MaZda software, and the optimal feature subset was obtained by combining three feature selection methods (FPM method) and Lasso regression. Then, six machine learning methods were used to build the prediction models. Receiver operating characteristic (ROC) curves were drawn to evaluate the prediction ability of the aforementioned models, and the area under the curve (AUC), accuracy, sensitivity and specificity were calculated. Results: Radiomics features of HCC in AP and PP were extracted by MaZda software, with 239 in each phase. There were 7 optimal features in AP and 14 optimal features in PP selected by FPM method and Lasso regression, respectively. The AUCs of decision tree, extreme gradient boosting, random forest, support vector machine (SVM), generalized linear model, and neural network based on the 7 optimal features in AP in the validation set were 0.736, 0.910, 0.913, 0.915, 0.897, 0.648, respectively. The SVM had the highest AUC in the validation set, with the accuracy, sensitivity and specificity of 95.35%, 95.83% and 94.74%, respectively. Likewise, the AUCs of machine learning models in prediction of MVI in HCC based on the 14 optimal features in PP in the validation set were 0.873, 0.876, 0.913, 0.859, 0.877, 0.834, respectively, and there were no significant differences (all P>0.05). The random forest had the highest AUC in the validation set, with the accuracy, sensitivity and specificity of 90.70%, 87.50% and 94.74%, respectively. Conclusion: Machine learning models based on dual-phase enhanced CT radiomics features can be used in preoperative prediction of MVI in HCC, particularly the SVM and random forest models have high prediction efficiency.

LncRNA OTUD6B-AS1 inhibits many cellular processes in colorectal cancer by sponging miR-21-5p and regulating PNRC2

Accumulating evidence has revealed that long noncoding RNAs (lncRNAs) play essential roles in regulating cellular process of various cancers. There have been many studies on the biological functions of lncRNAs in colorectal cancer (CRC). In this research, we explored the role and mechanism of lncRNA ovarian tumor domain containing 6B antisense RNA1 (OTUD6B-AS1) in CRC. Here, we detected OTUD6B-AS1 expression in CRC tissues and cells by RT-qPCR. Functional experiments were performed to test alterations in different cellular processes. Moreover, to verify the binding ability among the indicated RNA molecules, we carried out RIP, RNA pull-down and luciferase reporter assays. According to our data, OTUD6B-AS1 expression was low in CRC tissues and cells. Functionally, overexpression of OTUD6B-AS1 inhibited cell proliferation, migration, invasion and EMT, and promoted cell apoptosis. Bioinformatic analysis and mechanistical experiments confirmed that OTUD6B-AS1 could act as a competitive endogenous RNA (ceRNA) to upregulate Proline-Rich Nuclear Receptor Coactivator 2 (PNRC2) expression by sequestering miR-21-5p. Further rescue experiments validated the inhibitory function of the OTUD6B-AS1/miR-21-5p/PNRC2 axis in cellular process of CRC. Overall, OTUD6B-AS1 inhibits cellular development in CRC by sponging miR-21-5p and upregulating PNRC2, providing a novel insight into the exploration on CRC treatment.