Accuracy of quantitative viral secondary standards: a re-examination

Interlaboratory agreement of viral load assays depends on the accuracy and uniformity of quantitative calibrators. Previous work demonstrated poor agreement of secondary cytomegalovirus (CMV) standards with nominal values. This study re-evaluated this issue among commercially produced secondary standards for both BK virus (BKV) and CMV, using digital polymerase chain reaction (dPCR) to compare the materials from three different manufacturers. Overall, standards showed an improved agreement compared to prior work, against nominal values in both log10 copies/mL and log10 international unit (IU)/mL, with bias from manufacturer-assigned nominal values of 0.0-0.9 log10 units (either copies or IU)/mL. Standards normalized to IU and those values assigned by dPCR rather than by real-time PCR (qPCR) showed better agreement with nominal values. The latter reinforces prior conclusions regarding the utility of using such methods for quantitative value assignment in reference materials. Quantitative standards have improved over the last several years, and the remaining bias from nominal values might be further reduced by universal implementation of dPCR methods for value assignment, normalized to IU.

IMPORTANCE

Interlaboratory agreement of viral load assays depends on accuracy and uniformity of quantitative calibrators. Previous work, published in JCM several years ago, demonstrated poor agreement of secondary cytomegalovirus (CMV) standards with nominal values. This study re-evaluated this issue among commercially produced secondary standards for both BK virus (BKV) and CMV, using digital polymerase chain reaction (dPCR) to compare the materials from three different manufacturers. Overall, standards showed an improved agreement compared to prior work, against nominal values, indicating a substantial improvement in the production of accurate secondary viral standards, while supporting the need for further work in this area and for the broad adaption of international unit (IU) as a reporting standard for quantitative viral load results.

Two cities, two stages in transforming society-a mixed methods study comparing doctors' adoption of mobile apps for communication with patients in Hangzhou and Yancheng, China

Objectives

Mobile apps have become commonplace in doctor-patient communication over the last 20 years. Doctors mainly use two kinds of app, social networking apps (i.e., WeChat) and medical platform apps (i.e., Haodf). The purpose of this study was to investigate whether the attributes of social interaction in local society impact doctors' choice of mobile apps to communicate with patients. This article addresses two research questions: (a) To what degree do doctors' adoption patterns in different societies differ? (b) Why do doctors choose certain mobile apps to communicate with patients?

Methods

This study employed a mixed methods research design to analyze doctor's adoption behavior patterns in two cities, Hangzhou (HZ) and Yancheng (YC), which represent two stages in transforming society. Various patterns, measured as the percentage of doctors who utilize the medical platform app of Haodf among all doctors and the average service counts per doctor, were compared in three groups of tertiary hospitals: the top ones in HZ, the average ones in HZ, and the average ones in YC. We also conducted thematic content analysis of qualitative data from semi-structured interviews with 20 purposely selected doctors in the two cities.

Results

The percentages of doctors who have adopted the app of Haodf from the three groups of tertiary hospitals were 49.97%, 41.00%, and 32.03%, with an average service counts per doctor of 261, 182 and 39, respectively. According to the interviewees, doctors from YC are more likely to use social networking apps to communicate with patients than their HZ counterparts to maintain social connections with their relatives, friends, colleagues, and others.

Conclusion

This study demonstrates that doctors' choices of mobile apps are dependent upon social context. In traditional society, where people have close ties, the logic of using social networking apps lies in doctors' need to maximize the utility of their knowledge by maintaining social connections with others. In modern society, where the close ties between people have gradually weakened, the logic of using medical platform apps lies in doctors' needs for reputation marketing, either for themselves or for institutions, their affiliated departments or hospitals.

Obstructive sleep apnea affects the psychological and behavioural development of children-a case-control study

This study aims to investigate the effects of obstructive sleep apnea on paediatric psychological and behavioural abnormalities. A total of 1086 paediatric patients with obstructive sleep apnea and 728 sample snoring controls were enrolled in the study. Patients with obstructive sleep apnea underwent bilateral tonsillectomy plus adenoidectomy or adenoidectomy alone. Repeated Autism Behaviour Checklist, Spence Children's Anxiety Scale, and Children's Depression Inventory were performed to assess the autism symptoms, anxiety level and depressive symptoms before and after surgery. The score of Autism Behaviour Checklist in preschool children with obstructive sleep apnea was higher than that in control. In school children with obstructive sleep apnea, the score of Spence Children's Anxiety Scale was also higher. School children with obstructive sleep apnea with depressive symptoms were significantly higher than that in control. The scores of Autism Behaviour Checklist, Spence Children's Anxiety Scale, and Children's Depression Inventory in the obstructive sleep apnea group after surgery were significantly lower than that before surgery. Our study showed that the score of Spence Children's Anxiety Scale and Children's Depression Inventory had a close correlation with the illness course and hypoxia duration. The Spence Children's Anxiety Scale and Children's Depression Inventory scores are also closely associated with the Autism Behaviour Checklist score. These results suggest that obstructive sleep apnea may have a significant impact on autism symptoms, anxiety levels and depressive symptoms in children. We found that the longer the duration of the obstructive sleep apnea course and hypoxia, the greater the impact on anxiety level and depressive symptoms. The suspected autism symptoms, anxiety level and depressive symptoms in children with obstructive sleep apnea were also significantly correlated. Thus, early detection and timely treatment may often reverse the psychological and behavioural abnormalities caused by obstructive sleep apnea.

A multi-resolution TOF-DOI detector for human brain dedicated PET scanner

Objective. We propose a single-ended readout, multi-resolution detector design that can achieve high spatial, depth-of-interaction (DOI), and time-of-flight (TOF) resolutions, as well as high sensitivity for human brain-dedicated positron emission tomography (PET) scanners.Approach. The detector comprised two layers of LYSO crystal arrays and a lightguide in between. The top (gamma ray entrance) layer consisted of a 16 × 16 array of 1.53 × 1.53 × 6 mm3LYSO crystals for providing high spatial resolution. The bottom layer consisted of an 8 × 8 array of 3.0 × 3.0 × 15 mm3LYSO crystals that were one-to-one coupled to an 8 × 8 multipixel photon counter (MPPC) array for providing high TOF resolution. The 2 mm thick lightguide introduces inter-crystal light sharing that causes variations of the light distribution patterns for high DOI resolution. The detector was read out by a PETsys TOFPET2 application-specific integrated circuit.Main result. The top and bottom layers were distinguished by a convolutional neural network with 97% accuracy. All crystals in the top and bottom layers were resolved. The inter-crystal scatter (ICS) events in the bottom layer were identified, and the measured average DOI resolution of the bottom layer was 4.1 mm. The coincidence time resolution (CTR) for the top-top, top-bottom, and bottom-bottom coincidences was 476 ps, 405 ps, and 298 ps, respectively. When ICS events were excluded from the bottom layer, the CTR of the bottom-bottom coincidence was 277 ps.Significance. The top layer of the proposed two-layer detector achieved a high spatial resolution and the bottom layer achieved a high TOF resolution. Together with its high DOI resolution and detection efficiency, the proposed detector is well suited for next-generation high-performance brain-dedicated PET scanners.

Association of metabolic syndrome conditions with risk of second primary uterine cancer in breast cancer survivors

PURPOSE

Uterine cancer risk is high in breast cancer survivors. Although breast cancer and uterine cancer share some common epidemiological risk factors, association of metabolic syndrome with incident uterine cancer in breast cancer survivors is under-studied. We evaluated the association of metabolic syndrome conditions with second primary uterine cancer in breast cancer survivors.

METHODS

In this retrospective cohort study, 37,303 breast cancer patients diagnosed between 2008 and 2020 at Kaiser Permanente Southern California, an integrated healthcare system, were included. Data on cancer-related variables, sociodemographic, and clinical variables were extracted from KPSC's Surveillance, Epidemiology, and End Results (SEER)-affiliated cancer registry and electronic health records, as appropriate. Patients were followed from breast cancer diagnosis until 12/31/2021 for incident uterine cancer. Proportional hazards regression was used to report association [HR (95% CI)] between metabolic conditions and uterine cancer.

RESULTS

More than half (53.1%) of the breast cancer survivors had 1-2 metabolic conditions; 19.4% had 3 + , while 27. 5% had no metabolic conditions. Median time to follow-up was 5.33 years and 185 (0.5%) patients developed second primary uterine cancer. Obesity was associated with an elevated uterine cancer risk in the adjusted model [HR (95% CI) 1.64 (1.20-2.25)]. Having 1-2 metabolic conditions (versus none) was not associated with increased uterine cancer risk [adjusted HR (95% CI) 1.24 (0.85-1.82)]; however, there was an increased uterine cancer risk with 3 + metabolic conditions [adjusted HR (95% CI) 1.82 (1.16-2.87)].

CONCLUSION

Although not statistically significant, we found a trend demonstrating greater uterine cancer risk by increasing numbers of metabolic syndrome conditions in breast cancer survivors.

NtMYB1 and NtNCED1/2 control abscisic acid biosynthesis and tepal senescence in Chinese narcissus (Narcissus tazetta)

Chinese narcissus (Narcissus tazetta var. chinensis cv. 'Jinzhanyintai') is one of the 10 most famous traditional flowers of China, having a beautiful and highly ornamental flower with a rich fragrance. However, the flower longevity affects its commercial appeal. While petal senescence in Narcissus is ethylene-independent and abscisic acid-dependent, the regulatory mechanism has yet to be determined. In this study, we identified a R2R3-MYB gene (NtMYB1) from Narcissus tazetta and generated oeNtMYB1 and Ntmyb1 RNA interference mutants in Narcissus as well as an oeNtMYB1 construct in Arabidopsis. Overexpressing NtMYB1 in Narcissus or Arabidopsis led to premature leaf yellowing, an elevated level of total carotenoid, a reduced level of chlorophyll b, and a decrease in photosystem II fluorescence (Fv/Fm). A dual-luciferase assay and chromatin immunoprecipitation-quantitative PCR revealed that NtMYB1 directly binds to the promoter of NtNCED1 or NtNCED2 and activates NtNCED1/2 gene expression both in vitro and in vivo. Moreover, overexpressing NtMYB1 accelerated abscisic acid biosynthesis, up-regulated the content of zeatin and abscisic acid, and down-regulated the level of β-carotene and gibberellin A1, leading to petal senescence and leaf yellowing in Narcissus. This study revealed a regulatory process that is fundamentally different between non-photosynthetic organs and leaves.

Insight into the enhancement effect of amino functionalized carbon nanotubes on the H2S removal performance of nanofluid system

By constructing nanofluid system, trace functionalized nanoparticles can significantly enhance the absorption performance of basic liquid. In this work, amino functionalized carbon nanotubes (ACNTs) and carbon nanotubes (CNTs) were introduced into alkaline deep eutectic solvents to build nanofluid systems and used for the dynamic absorption of H2S. The experiment results showed that the introduction of nanoparticles can significantly enhance the H2S removal performance of original liquid. When performing H2S removal experiments, the optimal mass concentrations of ACNTs versus CNTs were 0.05 % and 0.01 %, respectively. The characterization showed that the surface morphology and structure of the nanoparticles unchanged significantly during the absorption-regeneration process. A double mixed gradientless gas-liquid reactor was used to explore the gas-liquid absorption kinetics characteristics of the nanofluid system. It was found that the gas-liquid mass transfer rate increased significantly after the addition of nanoparticles. The highest total mass transfer coefficient of the nanofluid system of ACNTs was increased to more than 400 % of the value before the addition of nanoparticles. The analysis showed that the shuttle effect and hydrodynamic effect of nanoparticles play important role in the process of enhancing gas-liquid absorption, and the amino functionalization enhanced the shuttle effect of nanoparticles significantly.

Analysis of Multimorbidity of Moderate to Severe Allergic Rhinitis in Children: A Real-World Study

INTRODUCTION

Allergic rhinitis (AR) in children is associated with various comorbidities, posing challenges for treatment and management. There have been few investigations of these multimorbidities in Chinese children with AR. Here, we investigated the prevalence of multimorbidities in children with moderate to severe AR and analyzed the influencing factors using real-world data.

METHODS

In total, 600 children who visited the outpatient clinic of our hospital and were diagnosed with moderate-severe AR were prospectively enrolled. All children underwent allergen detection and electronic nasopharyngoscopy. Parents or guardians completed a questionnaire that included age, sex, mode of delivery, feeding pattern, and familial history of allergy. The multimorbidities investigated included atopic dermatitis (AD), asthma, allergic conjunctivitis (AC), chronic rhinosinusitis (CRS), adenoid hypertrophy (AH), tonsil hypertrophy (TH), recurrent epistaxis, and recurrent respiratory tract infections (RRTIs).

RESULTS

The AR multimorbidities reported in children were as follows: recurrent epistaxis (46.5%), AC (46.3%), AD (40.7%), asthma (22.5%), RRIs (21.3%), CRS (20.5%), AH (19.7%), and TH (12.5%). In univariate logistic regression analysis, age (<6 years), birth mode, familial history of allergy, and single dust mite allergy were associated with AR multimorbidity (p < 0.05). Multivariate logistic regression revealed that a familial history of allergy was an independent risk factor for AC (odds ratio [OR] = 1.539, 95% confidence interval [CI]: 1.104-2.145) and AH (OR = 1.506, 95% CI: 1.000-2.267) (p < 0.05). Age (<6 years) was independently associated with the risk of AD (OR = 1.405, 95% CI: 1.003-1.969) and RRTIs (OR = 1.869, 95% CI: 1.250-2.793) (p < 0.05), cesarean section with AR and CRS risk (OR = 1.678, 95% CI: 1.100-2.561), and single dust mite allergy with asthma (OR = 1.590, 95% CI: 1.040-2.432) and CRS (OR = 1.600, 95% CI: 1.018-2.515) risk (p < 0.05). Further, non-dust mite allergy was independently associated with AR and CRS (OR = 2.056, 95% CI: 1.084-3.899).

CONCLUSION

AR was found to be accompanied by different comorbidities, including both allergic and non-allergic comorbidities, complicating disease treatment. These findings demonstrated that age (<6 years), familial history of allergy, types of allergens, and cesarean section were risk factors for different multimorbidities associated with AR.

Rearrangement of GO nanosheets with inner and outer forces under high-speed spin for supercapacitor

The self-standing graphene membranes are considered as ideal electrode materials for supercapacitors. However, maintaining highly regularized and uniform graphene membranes with satisfied electrochemical performance is still a challenge. Herein, with the chelation of metal cation and the radial shear force introduced by high-speed spinning, the uniform interlayer channels and shrunken cracks between adjacent nanosheets can be achieved in the metal-intercalated graphene oxide (GO) membranes, thus realizing regularization both in normal and radial direction. With the promotion in electron transfer and electrolyte penetration, the iron cross-linked GO membrane with spin coating for 40 cycles exhibits a high specific capacitance (427 F g^-1 at 1 A g^-1) and rate capability (42.6% capacitance retention from 1 to 40 A g^-1), as well as excellent cyclic capability (90.5% capacitance retention after 20,000 cycles). Particularly, a 21% increasement in capacitance can be achieved after high-speed spinning treatment. Moreover, the spin regularization strategy can be extended to GO membranes cross-linked by various multi-valence metal cations, the electrochemical performance of metal-cation cross-linked GO membrane electrodes after high-speed spinning treatment can also be improved obviously. Therefore, this paper provides a novel method to fabricate highly ordered GO membranes with promising electrochemical performance, which presents an immense potential application in membrane materials applied in energy storage, separation and catalysis.

A CNN-based four-layer DOI encoding detector using LYSO and BGO scintillators for small animal PET imaging

OBJECTIVE

We propose a novel four-layer depth-of-interaction (DOI) encoding phoswich detector using LYSO and BGO scintillator crystal arrays for high sensitivity and high spatial resolution small animal PET imaging. &#xD;Approach: The detector was comprised of a stack of four alternating LYSO and BGO scintillator crystal arrays coupled to an 8×8 multi-pixel photon counter (MPPC) array and read out by a PETsys TOFPET2 application specific integrated circuit (ASIC). The four layers from the top (gamma ray entrance) to the bottom (facing the MPPC) consisted of a 24×24 array of 0.99×0.99×6 mm3 LYSO crystals, a 24×24 array of 0.99×0.99×6 mm3 BGO crystals, a 16×16 array of 1.53×1.53×6 mm3 LYSO crystals and a 16×16 array of 1.53×1.53×6 mm3 BGO crystals. &#xD;Main results: Events that occurred in the LYSO and BGO layers were first separated by measuring the pulse energy (integrated charge) and duration (time over threshold (ToT)) from the scintillation pulses. Convolutional neural networks (CNNs) were then used to distinguish between the top and lower LYSO layers and between the upper and bottom BGO layers. Measurements with the prototype detector showed that our proposed method successfully identified events from all four layers. The CNN models achieved a classification accuracy of 91% for distinguishing the two LYSO layers and 81% for distinguishing the two BGO layers. The measured average energy resolution was 13.1% ± 1.7% for the top LYSO layer, 34.0% ± 6.3% for the upper BGO layer, 12.3% ± 1.3% for the lower LYSO layer, and 33.9% ± 6.9% for the bottom BGO layer. The timing resolution between each individual layer (from the top to the bottom) and a single crystal reference detector was 350 ps, 2.8 ns, 328 ps, and 2.1 ns respectively.&#xD;Significance: In conclusion, the proposed four-layer DOI encoding detector achieved high performance and is an attractive choice for next-generation high sensitivity and high spatial resolution small animal PET systems.

Synthesis and characterization of condensed Schiff bases and their iron salts with aldamine

As a result of the coordination polycondensation of p-phenylenediamine with glyoxal or terephthalaldehyde, two types of long-chain conjugated Schiff bases differing in structure were obtained. Their ferric salts were also obtained. Elemental analysis and infrared spectroscopy (FTIR) were used to evaluate the chemical structure of the obtained Schiff bases and their salts. Thermal stability (TGA) and electrical conductivity were also investigated.

Favorable outcome in advanced pheochromocytoma and paraganglioma after hypofractionated intensity modulated radiotherapy

PURPOSE

The purpose of this study was to review outcomes of patients with advanced/metastatic pheochromocytoma/paraganglioma (PPGL) treated at our institution with Intensity-modulated radiotherapy (IMRT), describe the treatment outcomes, and determine predictors.

METHODS

A retrospective study on patients with advanced/metastatic PPGL who received IMRT at Peking Union Medical College Hospital between 2014 and 2019. A total of 14 patients with 17 lesions were included in this study. Ultra-hypofractionated radiation therapy was used for 7 lesions in 5 patients, while hypofractionated radiation therapy was used for 8 lesions in 7 patients. 2 patients got conventional fractionated radiotherapy. Patients who received external beam radiation therapy were given a median total radiation dose of 74.4/130 Gy (BED10/3) in a median of 13 fractions.

RESULTS

OS at 2 years was 78% for all patients. For lesions evaluated by RECIST response, at least stable disease of the target lesion was achieved in 94% and distant progression in 28.5%, with an average time to progression of 5.2 months. Patients with locally advanced primary tumors or recurred in situ (n = 8) achieved 100% local control, and none of them got recurrence or distant metastasis after radiotherapy at last follow-up (median 29 months). Of patients with catecholamine-related syndromes (n = 12), 91% of symptomatic lesions improved following radiation therapy and a more than 50% decline in catecholamines.

CONCLUSIONS

We have found hypofractionated IMRT effective as an additional therapy for patients with advanced primary tumors or recurrence in situ and not amenable to complete surgical resection.

Aging behavior of three-proof polyurethane coatings under UV radiation

The influence of UV radiation on the physical and mechanical properties of polyurethane resins and three-proof polyurethane coatings was examined. Changes of mechanical properties and the gloss of resins and coatings were determined. The structure of materials was confirmed using scanning microscopy SEM and Fourier transform infrared spectroscopy FTIR; thermogravimetric TGA and DTG studies were also performed. It turned out that the gloss of finished protective coatings was worse than the gloss of individual resins, and aging significantly lowered these values (from 81.3° to 8.9° in case of resins and from 61.1° to 2.8° in case of coatings after 1200 hours of irradiation). Tensile strength of resins decreased constantly during aging while their elongation at break decreased than increased reaching minimum at exposure time of 100 hours. In case of coatings, both tensile strength and elongation at break firstly decreased than increased reaching minimum at exposure time of 800 hours; after long exposure time, more than 1200 hours, these properties decreased again.

Matrix Matters: Assessment of Commutability among BK Virus Assays and Standards

Quantitative testing of BK virus (BKPyV) nucleic acid has become the standard of care in transplant patients. While the relationship between interassay harmonization and commutability has been well characterized for other transplant-related viruses, it has been less well studied for BKPyV, particularly regarding differences in commutability between matrices. Here, interassay agreement was evaluated among six real-time nucleic acid amplification tests (NAATs) and one digital PCR (dPCR) BKPyV assay. Differences in the commutability of three quantitative standards was examined across all assays using a variety of statistical approaches. Panels, including 40 samples each of plasma and urine samples previously positive for BKPyV, together with one previously negative plasma sample and four previously negative urine samples, were tested using all assays, with each real-time NAAT utilizing its usual quantitative calibrators. Serial dilutions of WHO, National Institute for Standards and Technology (NIST), and commercially produced (Exact/Bio-Rad) reference materials were also run by each assay as unknowns. The agreement of the clinical sample values was assessed as a group and in a pairwise manner. The commutability was estimated using both relativistic and quantitative means. The quantitative agreement across assays in the urine samples was within a single log10 unit across all assays, while the results from the plasma samples varied by 2 to 3 log10 IU/mL. The commutability showed a similar disparity between the matrices. Recalibration using international standards diminished the resulting discrepancies in some but not all cases. Differences in the sample matrix can affect the commutability and interassay agreement of quantitative BKPyV assays. Differences in commutability between matrices may largely be due to factors other than those such as amplicon size, previously described as important in the case of cytomegalovirus. Continued efforts to standardize viral load measurements must address multiple sources of variability and account for differences in assay systems, quantitative standards, and sample matrices.

Constructing a Double Alternant "Rigid-Flexible" Structure for Simultaneously Strengthening and Toughening the Interface of Carbon Fiber/Epoxy Composites

An optimized "rigid-flexible" structure with multistage gradient modulus was constructed on carbon fiber (CF) surface via chemical grafting using "flexible" polyethyleneimine (PEI) and "rigid" polydopamine (PDA) between "rigid" CF and "flexible" epoxy (EP) to elaborate a double alternant "rigid-flexible" structure for simultaneously strengthening and toughening CF/EP composites. PDA and PEI polymers can greatly enhance the roughness and wettability of CF surfaces, further strengthening the mechanical interlocking and chemical interactions between CFs and epoxy. Besides, the "rigid-flexible" structure endows the interface with a gradient transition modulus, which could uniformly transfer internal stress and effectively avoid the stress concentration. Moreover, the double alternant "rigid-flexible" could buffer the external loading, induce more micro cracks and propagation paths and, thereby, consume more energy during the destruction of the composite. The interfacial shear strength, interlaminar shear strength, impact strength increased by 80.2%, 23.5% and 167.2%, and the fracture toughness improved by 227.2%, compared with those of the unmodified CF composite, respectively. This creative strategy and design afford a promising guidance for the preparation and production of advanced CF/EP structural materials with high strength and toughness.

Constructing a Superior Interfacial Microstructure on Carbon Fiber for High Interfacial and Mechanical Properties of Epoxy Composites

The interface quality is crucial for the properties of carbon fiber-reinforced polymer- matrix composites (CFRPs). In order to improve the interfacial and mechanical properties of CFRPs, a superior gradient modulus interfacial microstructure is constructed on the carbon fiber (CF) surface by chemically grafting a self-assembly carboxyl-terminated hyperbranched polymer (HP-COOH). A monofilament debonding test, a short beam shear test, an impact test and a dynamic mechanical thermal analysis (DMTA) were conducted to investigate the properties of the modified composite. Prominent improvements of 79.6% for the interfacial shear strength, 51.5% for the interlaminar shear strength, and 49.2% for the impact strength, as well as superior heat-resistance properties are achieved for composites with the gradient modulus interface over those of the untreated CF composites. The mechanism for performance improvement is mainly attributed to the enhanced CF surface energy, mechanical interlocking, and chemical bonding interactions. In particular, an atomic force microscopy (AFM) test proved that the gradient modulus interfacial microstructure formed by HP-COOH could widen the interface layer thickness and buffer the sharp variations in the modulus from CF to resin, thereby transmitting an external force and reducing the stress concentration. This work provides a facile and efficient strategy for constructing a superior and versatile interface for high- performance composites.

A Boronated Derivative of Temozolomide Showing Enhanced Efficacy in Boron Neutron Capture Therapy of Glioblastoma

There is an incontestable need for improved treatment modality for glioblastoma due to its extraordinary resistance to traditional chemoradiation therapy. Boron neutron capture therapy (BNCT) may play a role in the future. We designed and synthesized a ¹⁰B-boronated derivative of temozolomide, TMZB. BNCT was carried out with a total neutron radiation fluence of 2.4 ± 0.3 × 10¹¹ n/cm². The effects of TMZB in BNCT were measured with a clonogenic cell survival assay in vitro and PET/CT imaging in vivo. Then, ¹⁰B-boronated phenylalanine (BPA) was tested in parallel with TMZB for comparison. The IC50 of TMZB for the cytotoxicity of clonogenic cells in HS683 was 0.208 mM, which is comparable to the IC50 of temozolomide at 0.213 mM. In BNCT treatment, 0.243 mM TMZB caused 91.2% ± 6.4% of clonogenic cell death, while 0.239 mM BPA eliminated 63.7% ± 6.3% of clonogenic cells. TMZB had a tumor-to-normal brain ratio of 2.9 ± 1.1 and a tumor-to-blood ratio of 3.8 ± 0.2 in a mouse glioblastoma model. BNCT with TMZB in this model caused 58.2% tumor shrinkage at 31 days after neutron irradiation, while the number for BPA was 35.2%. Therefore, by combining the effects of chemotherapy from temozolomide and radiotherapy with heavy charged particles from BNCT, TMZB-based BNCT exhibited promising potential for therapeutic applications in glioblastoma treatment.

Thermal aging resistance of natural rubber compounded with conjugated Schiff base

Schiff’s base iron salt can be used as a new and effective antioxidant for rubber compounds.The tensile strength after 96 h of aging was approx. 36% and 12% higher, respectively, than in the caseof the antioxidants 4010NA and BHT used. Natural rubber vulcanizate (NR) containing the iron salt of Schiff’s base showed excellent rheological and mechanical properties, as well as very good thermalstability. These properties were far superior to that of other commercially available antioxidant rubber blends.

Clinical outcomes for Day 3 double cleavage-stage embryo transfers versus Day 5 or 6 single blastocyst transfer in frozen-thawed cycles: a retrospective comparative analysis

Objective

This study aimed to compare the clinical outcomes for transfer of Day 3 (D3) double cleavage-stage embryos and Day 5/6 (D5/6) single blastocysts in the frozen embryo transfer (FET) cycle to formulate a more appropriate embryo transplantation strategy.

Methods

We retrospectively analyzed 609 FET cycles from 518 women from April 2017 to March 2021. All FETs were assigned to the D3-DET group (transfer of a Day 3 double cleavage-stage embryo), D5-SBT group (transfer of a Day 5 single blastocyst), or D6-SBT group (transfer of a Day 6 single blastocyst). Clinical outcomes were comparatively analyzed.

Results

There were no significant differences in the biochemical pregnancy rate, clinical pregnancy rate, or ongoing pregnancy rate between the D3-DET and D5-SBT groups, but these rates in the two groups were all significantly higher compared with those in the D6-SBT group. The implantation rate in the D5-SBT group was significantly higher than that in the D3-DET group. The twin pregnancy rate in the D5-SBT and D6-SBT groups was significantly lower than that in the D3-DET group.

Conclusion

This study suggests that D5-SBT is the preferred option for transplantation. D6-SBT reduces the pregnancy rate, making it a more cautious choice for transfer of such embryos.

Aurora Kinase A as a Diagnostic and Prognostic Marker of Malignant Mesothelioma

Background

Malignant mesothelioma (MM) is a highly aggressive cancer with a poor prognosis. Despite the use of several well-known markers, the diagnosis of MM is still challenging in some cases. we applied bioinformatics to identify key genes and screen for diagnostic and prognostic markers of MM.

Methods

The expression profiles of GSE2549 and GSE112154 microarray datasets from the Gene Expression Omnibus database contained 87 cases of MM tissue and 8 cases of normal mesothelial tissue in total. The GEO2R tool was used to detect differentially expressed genes (DEGs). Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses of DEGs were performed using DAVID Bioinformatics Resources. The DEGs protein-protein interaction networks were constructed from the STRING database. Cytoscape was used to identify significant modules and hub genes. The GEPIA database was used to explore relationships between hub genes and prognosis of MM. Immunohistochemistry was used to analyze protein expression in tissue microarrays with 47 Chinese MM tissues. Statistical analyses diagnostic and prognostic values.

Results

346 DEGs were identified: 111 genes upregulated, and 235 downregulated. GO analysis showed that the primary biological processes of these DEGs were cell adhesion, leukocyte migration, and angiogenesis. The main cellular components included the extracellular space, extracellular exosome, and extracellular region. The molecular functions were integrin binding, heparin binding, and calcium ion binding. KEGG pathway analysis showed that DEGs are primarily involved in PPAR signaling pathway, extracellular matrix–receptor interactions, and regulation of lipolysis in adipocytes. Survival analysis showed that seven genes—AURKA, GAPDH, TOP2A, PPARG, SCD, FABP4, and CEBPA—may be potential prognostic markers for MM. Immunohistochemical studies showed that Aurora kinase A (AURKA gene encode, Aurora-A) and GAPDH were highly expressed in MM tissue in comparison with normal mesothelial tissue. Kaplan-Meier analysis confirmed a correlation between Aurora-A protein expression and overall survival but did not confirm a correlation with GAPDH. The receiver operating characteristic curves of Aurora-A protein expression suggested acceptable accuracy (AUC = 0.827; 95% CI [0.6686 to 0.9535]; p = 0.04). The sensitivity and specificity of Aurora-A were 83.33% and 77.78%, respectively.

Conclusion

Aurora-A could be an optimal diagnostic biomarker and a potential prognostic marker for MM.

MOF-derived NiFe2S4/Porous carbon composites as electromagnetic wave absorber

The preparation of strong absorption, thin thickness and wide band electromagnetic wave absorbers has always been the focus of research. In this paper, NiFe₂S₄/PC composites, an electromagnetic wave absorbing material with excellent performance, is prepared by introducing Ni-MOF, Fe and S elements into porous carbon framework. The material has a minimum reflection loss (RL_min) of -51.41 dB and the matching thickness is only 1.8 mm. In addition, the effective absorption bandwidth (EAB) is 4.08 GHz when the thickness is 1.9 mm. The rich interface and good impedance matching characteristics are the main reasons for the excellent absorbing performance of the material. The experimental results show that NiFe₂S₄/PC composites is a reasonable and effective electromagnetic wave absorption material.

Investigating the Relationships Between Public Health Literacy and Public Trust in Physicians in China's Control of COVID-19: A Cross-Sectional Study

Objective: Public trust in physicians and public health literacy (HL) are important factors that ensure the effectiveness of health-care delivery, particularly that provided during the SARS-CoV-2 pandemic. This study investigates HL as a predictor of public trust in physicians in China's ongoing efforts to control COVID-19. Methods: Data were gathered in February 2020 during the peak of the disease in China. Based on Nutbeam's conceptualization of HL, we measure HL vis-à-vis COVID-19 by using a six-item scale that includes two items each for functional, interactive, and critical HL. Trust in physicians was measured by assessing physicians' capability to diagnose COVID-19. A rank-sum test and ordinal logit regression modeling were used to analyze the data. Results: Two key findings: (a) trust in physician handling of treatment for COVID-19 is reported by about 74% of respondents; and (b) five of the six HL measures are positive predictors of public trust in physician treatment of the disease, with functional HL1 having the highest level of such association (coefficient 0.285, odds ratio 1.33%, p < 0.01). Conclusions: Improving public HL is important for better public-physician relationships, as well as for nations' efforts to contain the pandemic, serving as a possible behavioral, non-clinical antidote to COVID-19. Being confronted with the unprecedented virus, humans need trust. Health education and risk communication can improve public compliance with physicians' requirements and build a solid foundation for collective responses.

Efficacy and safety of rivaroxaban in patients with inferior vena cava filter placement without anticoagulation contraindications (EPICT): a prospective randomised controlled trial study protocol

INTRODUCTION

Inferior vena cava (IVC) filters are commonly used in patients with venous thromboembolism to prevent fatal pulmonary embolism, but the thrombosis risk increases after filter placement. Warfarin is a widely anticoagulant, but long-term monitoring and dose adjustments are required. Anticoagulation with rivaroxaban is more straightforward as it dose not require laboratory monitoring. This study compares the efficacy and safety of rivaroxaban and warfarin as an in anticoagulation therapy for patients with IVC filter placement.

METHODS AND ANALYSIS

This is a multicentre, randomised controlled trial. In total, 200 patients with deep vein thrombosis (DVT) with IVC filter implantation from 10 hospitals will be recruited. The patients will be randomised to the experimental group (rivaroxaban) or the control group (nadroparin overlapped with warfarin). The primary outcomes include death of any cause, pulmonary embolism (PE)-related death, bleeding and recurrent PE/DVT. The secondary outcomes include the percentage of other vascular events, IVC filter retrieval failure and net clinical benefits. This study aims to provide reliable, verification for the efficacy and safety of rivaroxaban antithrombotic therapy after IVC filter placement.

ETHICS AND DISSEMINATION

The study was approved by the Human Research Ethics Committee of the Second Affiliated Hospital of Zhejiang University School of Medicine (approval number: (2019) 295). The results will be disseminated through presentations at scientific conferences and publications in peer-reviewed journals TRIAL REGISTRATION NUMBER: NCT04066764.

Assessing local California trends in emergency physician opioid prescriptions from 2012 to 2020: Experiences in a large academic health system

OBJECTIVES

There has been increased focus nationally on limiting opioid prescriptions. National data demonstrates a decrease in annual opioid prescriptions among emergency medicine physicians. We analyzed data from 2012 to 2020 from a large academic health system in California to understand trends in opioid prescribing patterns for emergency department (ED) discharged patients and assessed the potential impact of two initiatives at limiting local opioid prescriptions.

METHODS

In 2012-2020, monthly ED visit data was used to evaluate the total number of outpatient opioid prescriptions and percent of ED visits with opioid prescriptions (as primary outcomes). Descriptive statistics, graphic representation, and segmented regression with interrupted times series were used based on two prespecified time points associated with intensive local initiatives directed at limiting opioid prescribing1) comprehensive emergency medicine resident education and 2) electronic health record (EHR)-based intervention.

RESULTS

Between March 2012 and July 2020, a total of 41,491 ED discharged patients received an opioid prescription. The three most commonly prescribed drugs were hydrocodone (84.1%), oxycodone (10.8%), and codeine (2.8%). After implementing comprehensive emergency medicine resident education, the total number of opioid prescriptions, the percentage of opioid prescriptions over total ED visit numbers and the total tablet number showed decreasing trends (p's ≤ 0.01), in addition to the natural (pre-intervention) decreasing trends. In contrast, later interventions in the EHR tended to show attenuated decreasing trends.

CONCLUSIONS

From 2012 to 2020, we found that total opioid prescriptions decreased significantly for discharged ED patients. This trend is seen nationally. However, our specific interventions further heightened this downward trend. Evidence-based legislation, policy changes, and educational initiatives that impact prescribing practices should guide future efforts.

Application Prospects and Prospect of Metabolomics in the Identification of Sudden Cardiac Death

Abstract

In cases of sudden death, the prevention of sudden cardiac death and the analysis of the cause of death after sudden cardiac death have always been a difficult problem. Therefore, clinical research and forensic pathological identification of sudden cardiac death are of great significance. In recent years, metabolomics has gradually developed into a popular field of life science research. The detection of "metabolic fingerprints" of biological fluids can provide an important basis for early diagnosis of diseases and the discovery of potential biomarkers. This article reviews the current research status of sudden cardiac death and the research on metabolomics of cardiovascular diseases that is closely related to sudden cardiac death and analyzes the application prospects of metabolomics in the identification of the cause of sudden cardiac death.

POS0788 CIRCULATING EXOSOMES PROMOTE LUPUS NEPHRITIS IN MRL-LPR MICE

Background:

Systemic Lupus Erythematosus (SLE) is a prototypic autoimmune disease that characterized by the loss of self-tolerance and the production of autoantibodies (autoAbs) [1, 2]. Lupus nephritis (LN), the severe organ-threatening manifestations of SLE, could cause massive damage to patients[3, 4]. Currently, some exosomal microRNAs (miRNAs) are considered as potential biomarkers in SLE. However, the role of exosomal miRNAs in Lupus Nephritis (LN) remains unclear.

Objectives:

The purpose of this study was to investigate molecular mechanism of plasma exosomal miRNAs in the development of Lupus Nephritis.

Methods:

Circulating exosomes were isolated from plasma of patients with LN, SLE without LN (NLN). Plasma exosomes were authenticated by Western Blot, Nanosight Tracking Analysis (NTA) and transmission electron microscopy (TEM). Fluorescence microscopy of co-cultured plasma exosomes and podocytes demonstrated that exosomes were uptaken into podocytes. Moreover, cell apoptosis and the inflammation factors was assessed using Western Blot. We analyzed the expression profiles of miRNAs in LN and NLN exosomes and the expression profiles of mRNAs of podocytes stimulated with LN and NLN exosomes with the help of next generation sequencing (NGS).

Results:

We demonstrate that exosomes derived from LN plasma could be taken by neighboring podocytes and promote the apoptosis of podocytes and the expression of inflammation factors. In addition, the sequencing found that miRNAs were differentially expressed in LN and NLN exosomes and mRNAs were differentially expressed in podocytes stimulated with LN and NLN exosomes.

Conclusion:

LN plasma exosomes have a potency to stimulate the apoptosis of podocytes and the expression of inflammation factors. Moreover, differentially expressed miRNAs in exosomes play a potential role in the development of LN.

References:

[1]T. Colasanti, A. Maselli, F. Conti, M. Sanchez, C. Alessandri, C. Barbati, D. Vacirca, A. Tinari, F. Chiarotti, A. Giovannetti, F. Franconi, G. Valesini, W. Malorni, M. Pierdominici, E. Ortona, Autoantibodies to estrogen receptor α interfere with T lymphocyte homeostasis and are associated with disease activity in systemic lupus erythematosus, Arthritis and rheumatism, 64 (2012) 778-787.

[2]H.A. Al-Shobaili, A.A. Al Robaee, A.A. Alzolibani, Z. Rasheed, Antibodies against 4-hydroxy-2-nonenal modified epitopes recognized chromatin and its oxidized forms: role of chromatin, oxidized forms of chromatin and 4-hydroxy-2-nonenal modified epitopes in the etiopathogenesis of SLE, Disease markers, 33 (2012) 19-34.

[3]A. Kaul, C. Gordon, M.K. Crow, Z. Touma, M.B. Urowitz, R. van Vollenhoven, G. Ruiz-Irastorza, G. Hughes, Systemic lupus erythematosus, Nat Rev Dis Primers, 2 (2016) 16039.

[4]M.G. Tektonidou, A. Dasgupta, M.M. Ward, Risk of End-Stage Renal Disease in Patients With Lupus Nephritis, 1971-2015: A Systematic Review and Bayesian Meta-Analysis, Arthritis & rheumatology (Hoboken, N.J.), 68 (2016) 1432-1441.

Disclosure of Interests:

None declared

AB0343 THE CHARACTERISTICS OF T CELLS IN SYSTEMIC LUPUS ERYTHEMATOSUS PATIENTS WITH ANXIETY BASED ON MACHINE LEARNING

Background:

Systemic lupus erythematosus (SLE) is an autoimmune disease, the immune system of patients to be disordered, especially in T cell subsets1. They were prone to mental diseases, anxiety particularly, which lead to suicide2. The recent study had reported that CD4+ T cells in the peripheral blood played the key role in like anxiety behavior of mice3. Although there showed that the level of serum TNF-α in SLE patients with anxiety was higher than without anxiety4, finding the important special mediators especially in T cell subsets was still necessary for the prevention of anxiety in SLE patients.

Objectives:

In total, 108 SLE patients, which met the diagnostic criteria of the American Society of rheumatology (v1997), were enrolled in this study from Affilliated Hospital of Nantong University, China. Exclusion criteria included other autoimmune diseases and active infection (including hepatitis B or C virus, Epstein-Barr virus, human immunodeficiency virus or Mycobacterium tuberculosis infection).

Methods:

We surveyed the abundance of 74 immune cell subpopulations from 108 SLE patients using flow cytometry, and investigated their differences between patients with and without anxiety (24 versus 84). Moreover, machine learning including Lasso regression, Random forest (RF) and Sparsity partial least squares discriminant analysis (sPLS-DA) was employed to build models and futher selected important features for the classification of SLE patients with anxiety.

Results:

SLE patients with anxiety showed higher body mass index (BMI) and lower quality of life. In their peripheral blood, the proportion of internal cell subsets composition of Th cell and Treg cells changed. By machine learning, we finally found that BMI and PD1-CD28- Treg played important rules to developing lupus anxiety.

Conclusion:

In this study, machine learning was applied to build models to select the most important T cell subset in SLE patients with anxiety. These findings suggested that BMI and imbalance of PD1-CD28- Treg containing effector memory Treg cells and effector Treg cells mostly played important roles in the development of SLE anxiety.

Disclosure of Interests:

None declared

POS0401 THE APPLICATION OF MTX-LOADING DNA TETRAHEDRON IN TREATING COLLAGEN-INDUCED ARTHRITIS MICE VIA REGULATING MACROPHAGE

Background:

Rheumatoid arthritis (RA) is a systemic autoimmune disease which mainly affect joints. [1]. Macrophages often infiltrate in the inflammatory joints. Activated macrophages release TNF-α, IL-1β to accelerate tissue damage, is one of the most important targets for RA intervention. The traditional drugs currently used commonly have some disadvantages cannot be bypassed[2], while DNA nanostructure is a new type of drugs have precise design, and likewise takes biological effect together[3]. We synthesized a DNA tetrahedron loaded with MTX and conjugated with HA which targeted to macrophage.

Objectives:

To verify whether MTX-loading DNA tetrahedron can regulate the apoptosis and polarization of macrophage and finally improve the condition of CIA model mice by while decrease the side effect of MTX.

Methods:

DNA TET was synthesized by mixing signal strand DNA in TM buffer and heated to 95 °C for 10 min, then cooling to 4 °C. Electrophoresis was applied to confirm the formation of TET. The absorbance of MTX solution was detected by microplate reader to analyze the loading efficiency of MTX into TET. Fluorescence microscope was used to observe the intake of TET into cells. CCK8 experiment was applied to measure the vitality of cells. Flow cytometry was used to detect the apoptosis and polarization. CIA model was established based on DBA/1 mice. Mice were randomly divided into five groups: normal group injected with NS; after established CIA model, CIA group injected with NS, MTX group injected with MTX solution, MTX-TET group injected with MTX-TET NP.

Results:

We synthesized DNA tetrahedron(A) and used 8% PAGE electrophoresis to confirmed the successfully synthesis(B). Then We found that when TET concentration fixed, the loading MTX concentration gradually increased and saturated at 190μM(C). While completely loading needed at least 4 hours(D). Fluorescence showed that single DNA strand cannot be taken by RAW, while TET can be easily taken by RAW(E). CCK8 showed that empty TET had no obvious effect on cells, while MTX and MTX-TET with equivalent concentration can obviously suppress the vitality(F). Similarly, the apoptosis trial showed that TET can slightly decrease the apoptosis of RAW, MTX and MTX-TET can significantly promote the apoptosis(G). Flow cytometry showed that the MTX-TET can decrease the expression of M1 marker CD80 (H).

At last, we treat mice with NS, TET, MTX and MTX-TET once a week after CIA model established, and found that TET have no significantly effect on mice, while MTX and MTX-TET can alleviate the inflammation symptom of paws(I).

Conclusion:

Conclusions: We synthesized MTX-loading DNA tetrahedron conjugated with HA, and found that the MTX-TET NP have the excellent ability of promote RAW apoptosis and relieve proinflammatory M1 polarization. while also can alleviate the symptom of CIA mice.

References:

[1]Aletaha D, Smolen JS: Diagnosis and Management of Rheumatoid Arthritis: A Review. JAMA 2018, 320(13):1360-1372.

[2]Smolen JS, Aletaha D, McInnes IB: Rheumatoid arthritis. Lancet 2016, 388(10055):2023-2038.

[3]Hu Q, Li H, Wang L, Gu H, Fan C: DNA Nanotechnology-Enabled Drug Delivery Systems. Chem Rev 2019, 119(10):6459-6506.

Figure 1.

Disclosure of Interests:

None declared

OP0073 SINGLE-CELL TRANSCRIPTOMICS UNCOVERS DEFECTIVE BONE MARROW EARLY B CELL DEVELOPMENT IN A SUBSET OF LUPUS PATIENTS ASSOCIATED WITH AGGRAVATED INFLAMMATION

Background:

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease that occurs when the body’s immune system attacks own tissues and organs. B cells play a central role in SLE pathogenesis by producing autoantibodies as well as antibody-independent functions. Peripheral B cell abnormality is well known in lupus patients such as expansions of plasmablasts and atypical memory B cells, which are associated with active diseases. However, little is known about the B cell development in the bone marrow of lupus patients.

Objectives:

We conduct this survey to explore the disorder of the B cell development in the bone marrow of lupus patients.

Methods:

In this study, we have performed the scRNASeq to profile the bone marrow B cell compartment in lupus patients and healthy donors.

Results:

We identified that in a subset of lupus patients, the early B cells (proB and preB cells) were strongly decreased, which were confirmed by flow cytometry in an expanded cohort. Furthermore, bone marrow B cells from these patients showed a strong proinflammatory signature revealed by pathway analysis. Interestingly, BCR repertoire analysis showed that the IGHV-4-34 was highly enriched in these patients, indicating an enhanced B cell tolerance defect. Finally, a panel of proinflammatory cytokines (TNF-a, IL-1a, IL-12p70, IFN-g, et al.) were strongly increased in the bone marrow plasma of these patients compared with early B normal patients and healthy donors, confirming a localized proinflammatory microenvironment.

Conclusion:

Altogether, the current study has revealed that a defective early B cell development in lupus patients is associated with a more severe B cell tolerance defect and aggravated inflammation, which may shed new light on developing novel therapies by targeting relevant pathways.

References:

[1]Min Wang, Hua Chen, Jia Qiu, et al. Antagonizing miR-7 suppresses B cell hyperresponsiveness and inhibits lupus development. J Autoimmun 2020.

[2]A M Jacobi, D M Goldenberg, F Hiepe, et al. Differential effects of epratuzumab on peripheral blood B cells of patients with systemic lupus erythematosus versus normal controls. Ann Rheum Dis, 2008.

Acknowledgements:

This work was funded by Special project of clinical medicine of Nantong University (Grant/Award number: 2019LQ001), National Natural Science Foundation of China (Grant/Award number: 81671616, 81871278 and 82071838).

Disclosure of Interests:

None declared

AB0639 EXOSOMES DERIVED FROM ENDOTHELIAL CELLS PREVENT OSTEOBLAST APOPTOSIS IN STEROID-INDUCED OSTEONECROSIS OF THE FEMORAL HEAD RAT MODEL VIA THE PI3K/AKT/Bcl-2 SIGNAL PATHWAY

Background:

Osteonecrosis of the femoral head (ONFH) is a common disease caused by many trauma factors and un-trauma factors. Among those un-trauma factors, steroid-induced osteonecrosis of the femoral head (SNFH) accounted for a large proportion and mainly concentrated in young people. SNFH has been reported as an irreversible disease and associated with the damage of blood vessels and the loss balance of bone homeostasis. Circulating endothelial progenitor cells (CEPCs), one part of circulating endothelial cells (CECs), are immature precursor cells with proliferative potential. The damage of vascular endothelial cells in SNFH has been confirmed by many studies, but the changes of CECs and CEPCs in the peripheral blood of patients with SNFH have not been studied yet.

Objectives:

The objective of the study is to explore the number of CECs and CEPCs in SNFH patients and normal people and then investigate whether EC-secreted exosomes (EC-exos) could prevent the progression of SNFH in rat model and its mechanism of action.

Methods:

We collect peripheral blood of 3 SNFH patients and 3 heathy people and detected the levels of CECs and CEPCs by Flow cytometer. TEM, NTA and western blot was used to characterize the isolated EC-exos. Annexin V-FITC/PI double staining with flow cytometric analysis and western blot were used to evaluate MC3T3-E1 cells apoptosis. CCK-8, scratching experiment and transwell were used to evaluate MC3T3-E1 cells viability and migration ability. Micro-CT and morphological staining were used to evaluate the progress of SNFH in rat model.

Results:

Firstly, we found that the number of CECs and CEPCs in the peripheral blood was decreased in SNFH patients than normal people. Then our results indicated that EC-exos could improve the migration, viability and prevent apoptosis of osteoblasts under dexamethasone by activating the PI3K/AKT/Bcl-2 signal pathway in vitro. Finally, our Micro-CT and morphological staining results in SNFH rat model revealed that EC-exos prevented the progression of SNFH.

Conclusion:

EC-exos could enhance the cell viability and migration ability of osteoblasts under dexamethasone and play an anti-apoptosis role against steroids-induced osteoblast apoptosis by activating the PI3K/AKT/Bcl-2 signal pathway. EC-exos prevented the progression of SNFH in rat model.

References:

[1]Zalavras CG, Lieberman JR. Osteonecrosis of the femoral head: evaluation and treatment. J Am Acad Orthop Surg. 2014;22(7):455-64.

[2]Microsurgery Department of the Orthopedics Branch of the Chinese Medical Doctor A, Group from the O, Bone Defect Branch of the Chinese Association of R, Reconstructive S, Microsurgery, Reconstructive Surgery Group of the Orthopedics Branch of the Chinese Medical A. Chinese Guideline for the Diagnosis and Treatment of Osteonecrosis of the Femoral Head in Adults. Orthop Surg. 2017;9(1):3-12.

[3]Mont MA, Jones LC, Hungerford DS. Nontraumatic osteonecrosis of the femoral head: ten years later. J Bone Joint Surg Am. 2006;88(5):1117-32.

[4]Yuan HF, Zhang J, Guo CA, Yan ZQ. Clinical outcomes of osteonecrosis of the femoral head after autologous bone marrow stem cell implantation: a meta-analysis of seven case-control studies. Clinics (Sao Paulo). 2016;71(2):110-3.

[5]Houdek MT, Wyles CC, Packard BD, Terzic A, Behfar A, Sierra RJ. Decreased Osteogenic Activity of Mesenchymal Stem Cells in Patients With Corticosteroid-Induced Osteonecrosis of the Femoral Head. J Arthroplasty. 2016;31(4):893-8.

Disclosure of Interests:

None declared.

POS0787 BERBERINE MODULATE LUPUS SYNDROME VIA THE REGULATION OF GUT MICROBIOTA IN MRL/LPR MICE

Background:

Intestinal flora disorder and immune abnormalities have been reported in systemic lupus erythematosus (SLE) patients1,2. Berberine (BBR) showed significant effects in regulating the intestinal flora, repairing gut barriers and regulating immune cells3,4. While few reports mentioned the abnormal gut microbiota and metabolites in Chinese SLE patients.

Objectives:

Our investigation tried to illustrate the relationship between gut microbiota, intestinal metabolites and disease activity in Chinese SLE patients. And the effect of BBR to intestinal dysbacteriosis, multiple organ damages and over-activated immune system in MRL/Lpr mice.

Methods:

16S high-throughput (16S rRNA) sequence, qRT-PCR and gas chromatography technology were used to determine the gut microbiota and metabolites in 104 SLE patients from Affiliated Hospital of Nantong University, China. BBR was orally treated to the MRL/Lpr mice in low, medium and high doses. After 6 weeks treatment, mice were sacrificed. Serum, faeces and organs were collected for further studies.

Results:

Chinese SLE patients showed higher abundance of Bacteroidetes and lower abundance of Firmcutes. The results of qRT-PCR showed high Firmcutes/Bacteroidetes (F/B) ratio of SLE patients. The F/B ratio was negative correlated with SLE disease activity index (SLEDA) score. Almost all the tested short-chain fatty acids (SCFAs) found statistically significant results in SLE and LN (lupus nephritis) patients, especially the propanoic acid and butyric. BBR altered the relative abundance of Bacteroides and Verrucomicrobia and the butyric acid content in colon of MRL/Lpr mice. The increase of tight junction protein also indicated the gut barrier was repaired by BBR. Treg and Tfr cells in spleen and mesenteric lymph node (MLN) were increased. These results revealed a positive therapeutic effect of berberine on SLE from gut microbiota to immune status.

Conclusion:

Our study highlights current status of intestinal dysbacteriosis in Chinese patients with SLE and differences in intestinal metabolites among patients with different disease states. The regulation of intestinal flora and the repairment of gut barrier by intestinal metabolites in BBR treated mice seemed to be the factor that directed the immune responses and disease outcomes. The ultimate goal of our study was to determine the beneficial effects of regulating the gut microbiota on the treatment of SLE. The application of berberine is a relatively safe and convenient way. In the coming investigations, we plan to focus on the study of berberine and its metabolites on intestinal function and systemic immunity.

References:

[1]Guo, M. et al. Alteration in gut microbiota is associated with dysregulation of cytokines and glucocorticoid therapy in systemic lupus erythematosus. Gut microbes11, 1758-1773, doi:10.1080/19490976.2020.1768644 (2020).

[2]Mu, Q. et al. Control of lupus nephritis by changes of gut microbiota. Microbiome5, 73, doi:10.1186/s40168-017-0300-8 (2017).

[3]Habtemariam, S. Berberine pharmacology and the gut microbiota: A hidden therapeutic link. Pharmacological research155, 104722, doi:10.1016/j.phrs.2020.104722 (2020).

[4]Cui, H. et al. Berberine Regulates Treg/Th17 Balance to Treat Ulcerative Colitis Through Modulating the Gut Microbiota in the Colon. Frontiers in pharmacology9, 571, doi:10.3389/fphar.2018.00571 (2018).

Figure 1.

Disclosure of Interests:

None declared

POS0761 INVESTIGATION ON THE EFFECT AND MECHANISM OF ABNORMALLY ACTIVATED CD8+ T CELLS FROM BONE MARROW ON HEMATOPOIETIC STEM CELLS IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS

Background:

SLE is an autoimmune disease characterized by the abnormal function of lymphocytes. The impairment of hematopoietic function of bone marrow participates in its pathogenesis, in which T cells play an important role. However, study on bone marrow T cells in SLE patients is very limited.

Objectives:

This study aims to characterize the phenotype and molecular characteristics of abnormally activated CD8+T cells in bone marrow of SLE patients and explore the mechanism of hematopoietic stem cells (HSCs) reduction caused by the abnormally activated CD8+T cells in bone marrow of patients with SLE.

Methods:

A total of 8 SLE patients and 5 age- and sex-matched controls were recruited in our study. Among them, 3 SLE patients and 4 donors were collected bone marrow and peripheral blood samples for Single-cell RNA sequencing (scRNA-seq) and functional studies. BM and peripheral T cell subsets were measured by flow cytometry. Plasma cytokines and secreted immunoglobulins were detected by Luminex. Disease activity of SLE patients was measured using the SLE Disease Activity Index (SLEDAI). All analyses were performed using R language and Flowjo 9.

Results:

In the present study, SLE patients had increased CD8+T%αβT cells and decreased CD4+T%αβT cells in bone marrow of SLE, compared to healthy controls. A large number of CD38+HLADR+CD8+T cells existed in the bone marrow and peripheral blood of SLE patients. Those patients also showed reduced number of HSCs, and with a downward trend of the numbers of peripheral red blood cells, white blood cells, neutrophils, hemoglobin, and platelets. By scRNA-seq, the CD38+HLADR+CD8+T cells contained high levels of GZMK, GZMA, PRF1, IFNG, and TNF in the bone marrow of SLE patients. the CD38+HLADR+CD8+T cells exhibited significant relationship with HSCs, white blood cells, neutrophils, and platelets.

Conclusion:

These findings demonstrated that the abnormally activated CD8+T cells in bone marrow can reduce the number of HSCs by the expression of killer molecules, which contributes to the impairment of hematopoietic function and the development of SLE. This project focuses on the specific bone marrow T cell subset in SLE. The completement of this project provides information for exploring the mechanism of hematopoiesis involvement.

References:

[1]Anderson E, Shah B, Davidson A, Furie R. Lessons learned from bone marrow failure in systemic lupus erythematosus: Case reports and review of the literature. Semin Arthritis Rheum. 2018;48(1):90-104.

[2]Sun LY, Zhou KX, Feng XB, Zhang HY, Ding XQ, Jin O, Lu LW, Lau CS, Hou YY, Fan LM. Abnormal surface markers expression on bone marrow CD34+cells and correlation with disease activity in patients with systemic lupus erythematosus. Clin Rheumatol. 2007;26(12):2073-2079.

Acknowledgements:

We want to thank Lu Meng, Teng Li, Wei Zhou, and Jiaxin Guo for their assistance with this study.

Disclosure of Interests:

None declared

POS0785 CHANGING EXPRESSION PROFILES OF LONG NONCODING RNAS, MIRNAS, MRNAS AND CIRCULAR RNAS IN LABIAL SALIVARY GLANDS OF PRIMARY SJÖGREN’S SYNDROME (PSS)

Background:

Primary Sjögren’s syndrome (pSS) is a relatively common autoimmune disease characterized by oral and ocular dryness. An increasing number of studies have revealed that long non-coding RNA (lncRNA), miRNA, mRNA and circular RNA (circRNA) contributes to the pathogenesis of autoimmune diseases.

Objectives:

To explore lncRNA, miRNA, mRNA and circRNA expression profiles in labial salivary glands (LSGs) in pSS patients and their biological functions in the regulation of pSS.

Methods:

The expression of 75,550 lncRNAs, 2,318 miRNA, 20,292 mRNAs and 6,877 circRNAs were determined in the LSG of six pSS patients and six healthy controls using microarray experiments. Validation was performed in pSS patients and controls using real-time PCR. LncRNA-mRNA co-expression and gene-pathway networks were constructed using bioinformatics software.

Results:

A total of 599 lncRNAs (upregulated: 279, downregulated: 320), 78 miRNAs (upregulated: 26, downregulated: 52), 615 mRNAs (upregulated: 590, downregulated: 25) and 160 mRNAs (upregulated: 110, downregulated: 50) were differentially expressed in the LSGs of pSS patients. Five of these lncRNAs were validated using real-time PCR. lncRNA HCP5, lncRNA SNHG5, lncRNA IFI44L, lncRNA CMPK2 were significantly upregulated and lncRNA TTYH1 were downregulated in pSS. GO and KEGG biological pathway analysis were performed to predict the functions of differentially expressed lncRNAs and co-expressed potential targeting genes. Subsequently, a ceRNA (lncRNA-miRNA-mRNA) network including 2320 ceRNA pairs was constructed based on predicted miRNAs shared by lncRNAs and mRNAs.

Conclusion:

The expression profile provided a systematic perspective on the potential functions of lncRNAs miRNAs, mRNAs and circRNAs in the pathogenesis of pSS. Therefore, this study will aid in the development of new diagnostic biomarkers and drug therapies.

References:

[1]Le Dantec C, Varin MM, Brooks WH, Pers JO, Youinou P, Renaudineau Y. Epigenetics and Sjogren’s syndrome.Curr Pharm Biotechnol. 2012 Aug;13(10):2046-53.

Disclosure of Interests:

None declared

AB0146 HAND AND WRIST ACTIVE RANGE OF MOTIONS AND CONTRIBUTING FACTORS IN RHEUMATOID ARTHRITIS: A CROSS-SECTIONAL STUDY

Background:

Patients with rheumatoid arthritis (RA) usually impaired range of motions (ROMs), especially hand and wrist active ROMs (AROMs), thus influencing their ability to perform daily activities and health-related quality of life (HR-QoL). However, little is known about the potential factors of reduced hand and wrist AROMs and their relations to quality of life in Chinese RA patients.

Objectives:

To explore the contributing factors of hand and wrist AROMs and their associations with HR-QoL and functional limitation in Chinese RA population.

Methods:

In this cross-sectional study, 108 patients were enrolled from Affiliated Hospital of Nantong University between November 2018 and July 2019. We measured all the participants’ AROMs with different directions of the hand and wrist in both sides, including volar flexion, ulnar deviation, radial deviation and radial deviation of the wrist joint, the first metacarpophalangeal (MCP1) flexion, interphalangeal (IP) flexion, volar abduction, radial abduction and thumb opposition (cm) in the thumb, average flexion, hypertension and abduction of the MCP2-5, average proximal interphalangeal (PIP) 2-5 and distal interphalangeal (DIP) 2-5 flexions, total active range of motion (TAM) of the second to the fifth fingers (TAM2-TAM5). Their sociodemographic, physical, psychological, disease-related data, acute phase reactants, laboratory indicators, drug usage and HR-QoL were examined as well. Statistical analysis used Pearson’s and Spearman’s correlation analysis, univariate and multivariate linear regression analyses.

Results:

In univariate analyses, we found that living in rural area, longer disease duration, comorbidity, hospitalization, more swollen joints, higher disease activity, pain level, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), red blood cell count and glucocorticoids usage were associated with most of the decreased hand and wrist AROMs (P ≤ 0.050), while higher education and annual income were related to most of the increased hand and wrist AROMs (P ≤ 0.048). In multivariate analyses, higher disease duration (P ≤ 0.023) and higher disease activity (P ≤ 0.033) were corelated with most of the decreased hand and wrist AROMs. Interestingly, the psychological factor, anxiety, was only positively associated with thumb opposition in both univariate and multivariate analyses (P ≤ 0.001). Additionally, most of the declined hand and wrist AROMs were associated with functional impairment and poor HR-QoL, especially in physical components (P < 0.05).

Conclusion:

Various factors, especially longer disease duration and higher disease activity, were related to decreased hand and wrist AROMs, and thus causing functional impairment and poor HR-QoL in RA patients. Clinical physicians and medical faculties should pay more attention to disease activity and disease-related symptoms of these patients in order to maintain their activity of daily living (ADL) ability and improve HR-QoL.

References:

[1]Rheumatoid arthritis. Nat Rev Dis Primers. 2018;4:18002.

[2]Zhang L, Cao H, Zhang Q, Fu T, Yin R, Xia Y, et al. Motion analysis of the wrist joints in Chinese rheumatoid arthritis patients: a cross-sectional study. BMC Musculoskelet Disord. 2018;19(1):270.

Acknowledgements:

This work was funded by Postgraduate Research & Practice Innovation Program of Jiangsu Province (Grant/Award number: KYCX19_2071), National Natural Science Foundation of China (Grant/Award number: 81871278, Science and technology Project of Jiangsu Province (Grant/Award number: BE2018671)

Disclosure of Interests:

None declared

Preparation and characterization of halogen-free flame retardant MCA core-shell microcapsules coated with melamine or acrylic acid resin

The resin melamine cyanurate (MCA) core-shell microcapsules were prepared by surface coatingmodification of halogen-free flame retardant MCA using melamine resin and acrylic resin as wall materials. The influence of different wall materials on the coating effect of halogen-free flame retardant MCA was studied by SEM, particle size analysis, IR, and DSC and TGA methods. The results showed that the melamine resin had a high degree of polymerization and decomposed at about 160°, which had a surface modification effect on MCA and did not affect its flame retardant performance. The surface coating rate of poly(methyl methacrylate) PMMA-MCA core-shell microcapsules was about 80%. Afteradding acrylic acid (AA) as the second monomer the coating effect was significantly improved and the thermal decomposition temperature of the wall material of the microcapsule was reduced.

Effects of carbon nanotubes and graphene on the structure and properties of natural rubber

Natural rubber (NR) is an important strategic material for national defense industry. It is also used in the food industry and medicine. However, due to the unsaturated double bond, its aging resistance, mechanical properties and solvent resistance are very poor. In order to improve these properties, carbon nanotubes (CNTs) and reduced graphene oxide (rGO) were used, added at 1 : 1 ratio. TheNR/CNTs/rGO nanocomposites were obtained by  mechanical mixing after adding 1, 2, 3 and 4 phr offiller. The influence of the filler content on the structure (TEM), vulcanization properties, abrasion and solvent resistance, mechanical properties, dynamic mechanical properties (DMA) and thermal properties (TGA) of nanocomposites was investigated. Increasing the content of CNTs/rGO increased the crosslinking density of the composites. TEM studies showed that CNTs and graphene sheets were evenly dispersed throughout the NR matrix. They also had good compatibility with the rubber matrix. The addition of CNTs and graphene increased the abrasion and solvent resistance as well as improved the mechanical properties. TGA analysis showed that the nanocomposites had excellent thermal stability. The best properties were obtained with the CNTs/rGO content of 2 phr.

Multi-omics integration identifies key upstream regulators of pathomechanisms in hypertrophic cardiomyopathy due to truncating MYBPC3 mutations

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is the most common genetic disease of the cardiac muscle, frequently caused by mutations in MYBPC3. However, little is known about the upstream pathways and key regulators causing the disease. Therefore, we employed a multi-omics approach to study the pathomechanisms underlying HCM comparing patient hearts harboring MYBPC3 mutations to control hearts.

RESULTS

Using H3K27ac ChIP-seq and RNA-seq we obtained 9310 differentially acetylated regions and 2033 differentially expressed genes, respectively, between 13 HCM and 10 control hearts. We obtained 441 differentially expressed proteins between 11 HCM and 8 control hearts using proteomics. By integrating multi-omics datasets, we identified a set of DNA regions and genes that differentiate HCM from control hearts and 53 protein-coding genes as the major contributors. This comprehensive analysis consistently points toward altered extracellular matrix formation, muscle contraction, and metabolism. Therefore, we studied enriched transcription factor (TF) binding motifs and identified 9 motif-encoded TFs, including KLF15, ETV4, AR, CLOCK, ETS2, GATA5, MEIS1, RXRA, and ZFX. Selected candidates were examined in stem cell-derived cardiomyocytes with and without mutated MYBPC3. Furthermore, we observed an abundance of acetylation signals and transcripts derived from cardiomyocytes compared to non-myocyte populations.

CONCLUSIONS

By integrating histone acetylome, transcriptome, and proteome profiles, we identified major effector genes and protein networks that drive the pathological changes in HCM with mutated MYBPC3. Our work identifies 38 highly affected protein-coding genes as potential plasma HCM biomarkers and 9 TFs as potential upstream regulators of these pathomechanisms that may serve as possible therapeutic targets.

Microsatellite markers reveal polymorphisms at the 3′ untranslated region of the SLC11A1 gene in Zhongdian Yellow cattle (Bos taurus)

Solute carrier family 11-member A1 (SLC11A1) gene encodes natural macrophage resistance-associated protein which regulates activity of macrophages against intracellular pathogens. The objective of this study was to study the polymorphism in the microsatellites present at 3′ untranslated region (UTR) of the SLC11A1 gene in 113 Zhongdian Yellow cattle (Bos taurus). Using DNA bi-directional sequencing, we detected seven alleles (GT10–16) for the first microsatellite (MS1), five alleles (GT12–16) for MS2, and four alleles (GT4–7) for MS3. MS3 is studied for the first time and revealed four novel variants (alleles GT4–7). Alleles GT12 (45.1%), GT13 (59.3%), and GT5 (85.4%) were the most frequent alleles at MS1, MS2, and MS3, respectively, Genotypes G12/12, G13/13, and G5/5 had the highest frequency 0.239, 0.540, and 0.743 at MS1, MS2, and MS3, respectively. Haplotypic data revealed that GT12/GT13 was the most frequent haplotype observed followed by GT12/14 haplotype. Three nucleotide variations were observed in MS1 and MS2. Comparative analysis of GT12/GT12 and GT13/GT13 genotype with other bovine genotypes showed significant difference (P > 0.05). Our results suggest that the homozygous genotypes GT12/GT12 and GT13/GT13 in Zhongdian Yellow cattle might be related to disease resistance. The findings reported in this study would be helpful in cattle breeding programs.

Preparation and characterization of attapulgite microcapsules coated with acrylic polymer

The attapulgite core-shell microcapsule type flame retardant was prepared by in situ polymerization. Attapulgite (ATP) was used as a core material with poly(methyl methacrylate) (PMMA) and poly(methyl methacrylate-co-acrylic acid) [P(MMA-co-AA)] as shell materials. The attapulgite was modified by the silane coupling agent. The effects of different shell materials and modification methods on the structure and properties of attapulgite core-shell microcapsules were studied by scanning electron microscopy, particle size distribution, infrared analysis and thermogravimetric analysis. The results showed that the coating effect was best when the amount of silane coupling agent was 1% of the attapulgite mass. The particle size of the microcapsule prepared with PMMA as shell material was uniform and the coating efficiency was better. After the copolymerization of acrylic acid (AA) in MMA shell materials, the cladding efficiency was improved. At the same time, the thermal decomposition temperature of the microcapsule shell material was greatly reduced, which is beneficial to the performance of attapulgite flame retardant.

Temporal feature prior-aided separated reconstruction method for low-dose dynamic myocardial perfusion computed tomography

Dynamic myocardial perfusion computed tomography (DMP-CT) is an effective medical imaging technique for coronary artery disease diagnosis and therapy guidance. However, the radiation dose received by the patient during repeated CT scans is a widespread concern of radiologists because of the increased risk of cancer. The sparse few-view CT scanning protocol can be a feasible approach to reduce the radiation dose of DMP-CT imaging; however, an advanced reconstruction algorithm is needed. In this paper, a temporal feature prior-aided separated reconstruction method (TFP-SR) for low-dose DMP-CT images reconstruction from sparse few-view sinograms is proposed. To implement the proposed method, the objective perfusion image is divided into the baseline fraction and the enhancement fraction introduced by the arrival of the contrast agent. The core of the proposed TFP-SR method is the utilization of the temporal evolution information that naturally exists in the DMP-CT image sequence to aid the enhancement image reconstruction from limited data. The temporal feature vector of an image pixel is defined by the intensities of this pixel in the pre-reconstructed enhancement sequence, and the connection between two related features is calculated via a zero-mean Gaussian function. A prior matrix is constructed based on the connections between the extracted temporal features and used in the iterative reconstruction of the enhancement images. To evaluate the proposed method, the conventional filtered back-projection algorithm, the total variation regularized PWLS (PWLS-TV) and the prior image constrained compressed sensing are compared in this paper based on studies on a digital extended cardiac-torso (XCAT) thoracic phantom and a preclinical porcine DMP-CT data set that take image misregistration into account. The experimental results demonstrate that the proposed TFP-SR method has superior performance in sparse DMP-CT images reconstruction in terms of image quality and the analyses of the time attenuation curve and hemodynamic parameters.

An improved patch-based regularization method for PET image reconstruction

Background

Statistical reconstruction methods based on penalized maximum likelihood (PML) are being increasingly used in positron emission tomography (PET) imaging to reduce noise and improve image quality. Wang and Qi proposed a patch-based edge-preserving penalties algorithm that can be implemented in three simple steps: a maximum-likelihood expectation-maximization (MLEM) image update, an image smoothing step, and a pixel-by-pixel image fusion step. The pixel-by-pixel image fusion step, which fuses the MLEM updated image and the smoothed image, involves a trade-off between preserving the fine structural features of an image and suppressing noise. Particularly when reconstructing images from low-count data, this step cannot preserve fine structural features in detail. To better preserve these features and accelerate the algorithm convergence, we proposed to improve the patch-based regularization reconstruction method.

Methods

Our improved method involved adding a total variation (TV) regularization step following the MLEM image update in the patch-based algorithm. A feature refinement (FR) step was then used to extract the lost fine structural features from the residual image between the TV regularized image and the fused image based on patch regularization. These structural features would then be added back to the fused image. With the addition of these steps, each iteration of the image should gain more structural information. A brain phantom simulation experiment and a mouse study were conducted to evaluate our proposed improved method. Brain phantom simulation with added noise were used to determine the feasibility of the proposed algorithm and its acceleration of convergence. Data obtained from the mouse study were divided into event count sets to validate the performance of the proposed algorithm when reconstructing images from low-count data. Five criteria were used for quantitative evaluation: signal-to-noise ratio (SNR), covariance (COV), contrast recovery coefficient (CRC), regional relative bias, and relative variance.

Results

The bias and variance of the phantom brain image reconstructed using the patch-based method were 0.421 and 5.035, respectively, and this process took 83.637 seconds. The bias and variance of the image reconstructed by the proposed improved method, however, were 0.396 and 4.568, respectively, and this process took 41.851 seconds. This demonstrates that the proposed algorithm accelerated the reconstruction convergence. The CRC of the phantom brain image reconstructed using the patch-based method was iterated 20 times and reached 0.284, compared with the proposed method, which reached 0.446. When using a count of 5,000 K data obtained from the mouse study, both the patch-based method and the proposed method reconstructed images similar to the ground truth image. The intensity of the ground truth image was 88.3, and it was located in the 102^nd row and the 116^th column. However, when the count was reduced to below 40 K, and the patch-based method was used, image quality was significantly reduced. This effect was not observed when the proposed method was used. When a count of 40 K was used, the image intensity was 58.79 when iterated 100 times by the patch-based method, and it was located in the 102^nd row and the 116^th column, while the intensity when iterated 50 times by the proposed method was 63.83. This suggests that the proposed method improves image reconstruction from low-count data.

Conclusions

This improved method of PET image reconstruction could potentially improve the quality of PET images faster than other methods and also produce better reconstructions from low-count data.

DaNet: dose-aware network embedded with dose-level estimation for low-dose CT imaging

Many deep learning (DL)-based image restoration methods for low-dose CT (LDCT) problems directly employ the end-to-end networks on low-dose training data without considering dose differences. However, the radiation dose difference has a great impact on the ultimate results, and lower doses increase the difficulty of restoration. Moreover, there is increasing demand to design and estimate acceptable scanning doses for patients in clinical practice, necessitating dose-aware networks embedded with adaptive dose estimation. In this paper, we consider these dose differences of input LDCT images and propose an adaptive dose-aware network. First, considering a large dose distribution range for simulation convenience, we coarsely define five dose levels in advance as lowest, lower, mild, higher and highest radiation dose levels. Instead of directly building the end-to-end mapping function between LDCT images and high-dose CT counterparts, the dose level is primarily estimated in the first stage. In the second stage, the adaptively learned low-dose level is used to guide the image restoration process as the pattern of prior information through the channel feature transform. We conduct experiments on a simulated dataset based on original high dose parts of American Association of Physicists in Medicine challenge datasets from the Mayo Clinic. Ablation studies validate the effectiveness of the dose-level estimation, and the experimental results show that our method is superior to several other DL-based methods. Specifically, our method provides obviously better performance in terms of the peak signal-to-noise ratio and visual quality reflected in subjective scores. Due to the dual-stage process, our method may suffer limitations under more parameters and coarse dose-level definitions, and thus, further improvements in clinical practical applications with different CT equipment vendors are planned in future work.

Simple and effective purification of a SGLT-2 inhibitor cocrystal Rongliflozin l-pyroglutamic acid: coformer-induced purification

We report and design a simple and robust process to obtain a single and pure crystalline form I (1) of the cocrystal, containing Rongliflozin (2) with l-pyroglutamic acid (l-PA), based on coformer-induced purification (CoIP).

A digital phoswich detector using time-over-threshold for depth of interaction in PET

We present the performance of a digital phoswich positron emission tomography (PET) detector, composed by layers of pixilated scintillator arrays, read out by solid state light detectors and an application specific integrated circuit (ASIC). We investigated the use of integrated charge from the scintillation pulses along with time-over-threshold (ToT) to determine the layer of interaction (DOI) in the scintillator. Simulations were performed to assess the effectiveness of the ToT measurements for separating the scintillator events and identifying cross-layer-crystal-scatter (CLCS) events. These simulations indicate that ToT and charge integration from such a detector provide sufficient information to determine the layer of interaction. To demonstrate this in practice, we used a pair of prototype LYSO/BGO detectors. One detector consisted of a 19 × 19 array of 7 mm long LYSO crystals (1.36 mm pitch) coupled to a 16 × 16 array of 8 mm long BGO crystals (1.63 mm pitch). The other detector was similar except the LYSO crystal pitch was 1.63 mm. These detectors were coupled to an 8 × 8 multi-pixel photon counter mounted on a PETsys TOFPET2 ASIC. This high performance ASIC provided digital readout of the integrated charge and ToT from these detectors. We present a method to separate the events from the two scintillator layers using the ToT, and also investigate the performance of this detector. All the crystals within the proposed detector were clearly resolved, and the peak to valley ratio was 11.8 ± 4.0 and 10.1 ± 2.9 for the LYSO and BGO flood images. The measured energy resolution was 9.9% ± 1.3% and 28.5% ± 5.0% respectively for the LYSO and BGO crystals in the phoswich layers. The timing resolution between the LYSO-LYSO, LYSO-BGO and BGO-BGO coincidences was 468 ps, 1.33 ns and 2.14 ns respectively. Results show ToT can be used to identify the crystal layer where events occurred and also identify and reject the majority of CLCS events between layers.