Material radiopurity control in the XENONnT experiment

The selection of low-radioactive construction materials is of the utmost importance for rare-event searches and thus critical to the XENONnT experiment. Results of an extensive radioassay program are reported, in which material samples have been screened with gamma-ray spectroscopy, mass spectrometry, and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^{222}$$\end{document}222Rn emanation measurements. Furthermore, the cleanliness procedures applied to remove or mitigate surface contamination of detector materials are described. Screening results, used as inputs for a XENONnT Monte Carlo simulation, predict a reduction of materials background (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\sim $$\end{document}∼17%) with respect to its predecessor XENON1T. Through radon emanation measurements, the expected \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^{222}$$\end{document}222Rn activity concentration in XENONnT is determined to be 4.2 (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^{+0.5}_{-0.7}$$\end{document}-0.7+0.5) \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\upmu $$\end{document}μBq/kg, a factor three lower with respect to XENON1T. This radon concentration will be further suppressed by means of the novel radon distillation system.

Dietary Magnesium Intake Level Modifies the Association Between Vitamin D and Insulin Resistance: A Large Cross-Sectional Analysis of American Adults

Background

Previous clinical studies and randomized controlled trials have revealed that low serum vitamin D levels are associated with the risk of developing insulin resistance. Magnesium has been reported to be a protective factor for insulin resistance, and magnesium has been considered an important co-factor for vitamin D activation. However, the effect of dietary magnesium intake on the relationship between vitamin D and the risk of developing insulin resistance has not been comprehensively investigated. Therefore, we designed this cross-sectional analysis to assess whether dietary magnesium intake modifies the association of vitamin D and insulin resistance.

Methods

A total of 4,878 participants (male: 48.2%) from 4 consecutive cycles of the National Health and Nutrition Examination Survey (2007-2014) were included in this study after a rigorous screening process. Participants were stratified by their dietary magnesium intake into low-intake (<267 mg/day) and high-intake (≥267 mg/day) groups. We assessed differences between serum vitamin D levels and the risk of developing insulin resistance (interaction test), using a weighted multivariate logistic regression to analyze differences between participants with low and high magnesium intake levels.

Results

There was a negative association between vitamin D and insulin resistance in the US adult population [OR: 0.93 (0.88-0.98)], P < 0.001. Dietary magnesium intake strengthened the association (P for interaction < 0.001). In the low dietary magnesium intake group, vitamin D was negatively associated with the insulin resistance [OR: 0.94 (0.90-0.98)]; in the high dietary magnesium intake group, vitamin D was negatively associated with insulin resistance [OR: 0.92 (0.88-0.96)].

Conclusion

Among adults in the United States, we found an independent association between vitamin D level and insulin resistance, and this association was modified according to different levels of magnesium intake.

AB1043 IDENTIFICATION OF UNUSUAL TOPHI ANTERIOR TO THE THYROID CARTILAGE USING DIFFERENT IMAGING METHODS

Background

Inadequately treated gout patients could develop tophi. However, tophi could appear as atypical mass, leading to difficulty in differential diagnosis.

Objectives

The objectives of the study were to describe an unusual case with tophi anterior to the Thyroid Cartilage using different imaging methods.

Methods

Clinical information of the case was presented. Ultrasound, dual energy Computed Tomography (DECT) and CT scan were compared to describe the tophi.

Results

A 66-year-old man with a 30-year history of gout was admitted. He had received urate-lowering drugs intermittently over the past few years. Physical examination revealed multiple tophi on the hands, feet, and other auricular surfaces. Moreover, there was a subcutaneous mass above the thyroid cartilage (Figure 1A). Ultrasound revealed hyperechoic nodule anterior to the thyroid cartilage, 11*7cm in size, with uneven internal echo, no blood flow signal inside, and a close relationship between the barrier of the nodule and the thyroid cartilage (Figure 1B). DECT of the neck confirmed that the mass anterior to the thyroid cartilage were tophi (Figure 1C-D). A plain radiographic evaluation demonstrated soft-tissue swellings and para-articular erosions involving hands (Figure 1E-F). The serum creatinine and uric acid levels were elevated as follows, creatinine, 562 μmol per liter (normal range, 31.8 to 116); and uric acid, 621 μmol per liter (normal range, 90 to 420).

Figure 1.

Tophi detected by different imaging methods. A.A picture of the mass anterior to the thyroid cartilage; B. A mass anterior to the thyroid cartilage detected by ultrasound; C. The mass anterior to the thyroid cartilage detected by dual energy CT; D. The mass anterior to the thyroid cartilage detected by CT scan; E. a picture of tophi in the hands; F. a plain radiograph of tophi in the hands.

Conclusion

DECT has more advantages over ultrasound and CT for detection of atypical tophi in gout patients.

Disclosure of Interests

Yutong Jiang Grant/research support from: Scientific and Technological Planning Project of Guangzhou City [grant number 202102020150], Xinyu Wu: None declared, Zetao Liao: None declared, Jun Qi: None declared, Jieruo Gu: None declared

Effect of rehabilitation on the long-term efficacy of botulinum toxin-A for spastic cerebral palsy

OBJECTIVE

To investigate the long-term effects of botulinum toxin-A (BTX-A) nerve block on relaxation of spasticity in cerebral palsy.

PATIENTS AND METHODS

From June 2015 to December 2018, 52 children, aged 20-56 months, with spastic cerebral palsy were treated with BTX-A. The dose of BTX-A was selected based on the weight of the child and the modified Ashworth scale (MAS). The injection dose ranged from 45 IU to 150 IU (average 68.0±31.6 IIU). The muscle tone and motor functions of all children were evaluated before the block. The spasticity was measured using the MAS, and the motor function was measured using the Physician Rating Scale (PRS) and the gross motor function measure (GMFM). After two years, all children were re-evaluated.

RESULTS

No significant difference was observed between the trial and control groups in terms of age, weight, MAS, PRS, and GMFM measurements before the block (p>0.05). The PRS and GMFM improved significantly in both groups after two years (p<0.05). The PRS and GMFM in the trial group increased more significantly than those in the control group (p<0.05).

CONCLUSIONS

The BTX-A block showed a long-term positive effect. Rehabilitation training after the block could help children to improve their motor functions.

Disease Burden and Attributable Risk Factors of Alzheimer's Disease and Dementia in China from 1990 to 2019

BACKGROUND

Updated information on the burden of Alzheimer's disease and other forms of dementia are of great importance for evidence-based health care planning. However, such an estimate has been lacking in Chinese populations at both national and provincial levels.

OBJECTIVE

To estimate the temporal trends and the attributable burdens of selected risk factors of Alzheimer's disease and other forms of dementia in China.

DESIGN, SETTING, AND PARTICIPANTS

This is an observational description of the Global Burden of Diseases Study 2019 (GBD 2019). Data on incidence, mortality, prevalence, disability-adjusted life years (DALYs), years lived with disability (YLDs), and years of life lost (YLLs) of Alzheimer's disease and other forms of dementia were derived from the GBD 2019 study at both national and provincial levels in China.

MEASUREMENTS

Six indicators were used: incidence, mortality, prevalence, DALYs, YLLs, and YLDs. Absolute numbers in detail by age, sex, region, and age-standardized rates (with 95% uncertainty intervals) were calculated.

RESULTS

There were notable increasing trends in the number of deaths (247·9%), incidence (264·8%), prevalence (296·5%), DALYs (228·1%), YLDs (308·7%) and YLLs (201·7%) from 1990 to 2019, respectively. The corresponding age-standardized rates increased by 6·2%, 19·3%, 33·6%, 10·7%, 33·4% and 3·1%. Smoking, high body mass index, high fasting plasma glucose levels, and metabolic risks were the four leading risk factors. Higher burden was observed among females versus males and in the more developed regions.

CONCLUSIONS

The disease burden in China were increasing substantially. Regional differences of the disease burden are accompanied by discrepancies of economic level and geographical location, as well as different levels of exposure to risk factors. Targeted prevention and control strategies are urgently needed to reduce the disease burden.

Mucoadhesive Nucleoside-Based Hydrogel Delays Oral Leukoplakia Canceration

Some oral squamous cell carcinomas (OSCCs) originate from preexisting oral potentially malignant disorders (OPMDs). Oral leukoplakia (OLK) is the most common and typical OPMD in the clinic, so treatment for it is essential to reduce OSCC incidence. Local chemotherapy is an option other than surgery considering the superficial site of OLK. However, there are no standardized drugs applied to OLK, and traditionally used chemotherapeutic drugs revealed limited efficacy for lack of adhesion. Hence, there is a growing demand to prepare new agents that combine mucoadhesion with an anti-OLK effect. Here, an isoguanosine-tannic acid (isoG-TA) supramolecular hydrogel via dynamic borate esters was successfully fabricated based on isoG and TA. Previously reported guanosine-TA (G-TA) hydrogel was also explored for an anti-OLK effect. Both gels not only exhibited ideal adhesive properties but also integrated anti-OLK activities in one system. In vitro cell viability indicated that isoG and TA inhibited the proliferation of dysplastic oral keratinocytes (DOKs). The in vivo OLK model evidence revealed that both gels showed potential to prevent OLK canceration. In addition, the probable anti-DOK mechanisms of isoG and TA were investigated. The results indicated that isoG could bind to adenosine kinase (ADK) and then affected the mammalian target of rapamycin (mTOR) pathway to inhibit DOK proliferation. TA could significantly and continuously reduce reactive oxygen species (ROS) in DOKs through its antioxidant effect. ROS plays an important role in the progression of cell cycle. We proved that the low level of ROS may inhibit DOK proliferation by inducing G₀/G₁ arrest in the cell cycle. Altogether, this study innovatively fabricated an isoG-TA hydrogel with ideal adhesion, and both isoG and TA showed in vitro inhibition of DOKs. Moreover, both isoG-TA and G-TA hydrogels possessed potential in delaying the malignant transformation of OLK, and the G-TA hydrogel showed a better statistical effect, providing an effective strategy for controlling OLK.

Insights into tribofilm formation on Ti-6V-4Al in a bioactive environment: Correlation between surface modification and micro-mechanical properties

Ti-6Al-4V has been used as a surgical implant material for a long time because of its combination of strength, corrosion resistance and biocompatibility. However, there remains much that is not understood about how the surface reacts with the environment under tribocorrosion conditions. In particular, the conditions under which tribofilms form and their role on friction and wear are not clear. To evaluate the complicated nature of the dynamic surface microstructural changes on the wear track, high resolution transmission electron microscopy (TEM), scanning transmission electron microscope (STEM) and electron energy loss spectroscopy (EELS) have been used to characterise the structure and chemical composition of the tribofilm. Detailed analysis of the formation and structure of the tribofilm and the metal surface deformation behaviour were studied as a function of applied potential and the role of proteins in the lubricant. For the first time, graphitic and onion-like carbon structures from wear debris were found in the testing solution. The presence of carbon nanostructures in the tribocorrosion process and the formation of the tribofilm leads to an improved tribocorrosion behaviour of the system, in particular a reduction in wear and friction. A detailed, quantitative, analysis of surface deformation was undertaken, in particular, the geometrically necessary dislocation (GND) density was quantified using precession electron diffraction (PET). A clear correlation between applied potential, tribofilm formation and the surface strain was established. STATEMENT OF SIGNIFICANCE: The formation of tribofilm and microstructure modification of the Ti-6Al-4V surface during tribocorrosion in a physiological environment is not fully understood. In particular, the correlation between microstructural changes and electrochemical conditions is not clear. This study presents a detailed investigation of the structure and chemical composition of tribofilms at the nanoscale during tribocorrosion tests in simulated body fluid and gives a detailed and quantitative description of the evolved surface structure. A clear correlation between applied potential, tribofilm formation and the surface strain was established. Moreover, particular attention is paid to the wear debris particles captured from the lubricating solution, including nanocarbon onion structures. The implications for tribocorrosion of the alloy in its performance as an implant are discussed.

Deacetylation of FOXO4 by Sirt1 stabilizes chondrocyte extracellular matrix upon activating SOX9

OBJECTIVE

FOXO4 has essential roles in cellular metabolism and prevents cartilage degeneration in osteoarthritis (OA). Here we aim to provide evidence that deacetylated-FOXO4 stabilizes chondrocyte (CH) extracellular matrix (ECM) related to SOX9 activation.

PATIENTS AND METHODS

We used Chromatin immunoprecipitation (ChIP) and Dual-Luciferase reporter assay to verify that the FOXO4 protein activates SOX9 by binding to its promoter. We cultured human CHs with IL-1β to cause degeneration and supplied Sirt1 protein to deacetylate FOXO4. To confirm the function of FOXO4 and SOX9 during CHs degeneration, we also used the FOXO4 and SOX9 silenced CHs by siRNA transfection as a comparison. Western blot assay was used to analyze the protein level of Sirt1, SOX9, and the acetylated condition of FOXO4. Besides, RT-PCR was used to measure the mRNA level of collagen I/II/X, aggrecan, MMP-13, and ADAMTS-5 for determining the ECM states.

RESULTS

FOXO4 protein transcriptionally activates SOX9 expression by binding to its promoter. Under the IL-1β stimulation, FOXO4 acetyl-lysine rate increased, and the SOX9 protein expression decreased, which was alleviated after the supplement of exogenic Sirt1 protein. Meanwhile, Sirt1 overexpression increased the collagen II and aggrecan and reduced the collagen I, collagen X, MMP-13, and ADAMTS-5 mRNA expression. However, the silencing of FOXO4 abolished the Sirt1 induced SOX9 expression and weakened the ECM production stability. Additionally, SOX9 silencing also alleviated the effect of the Sirt1 supplement on the degenerated CHs, though the FOXO4 was highly deacetylated.

CONCLUSIONS

FOXO4 acetylation aggravates during the degeneration of CHs, and the deacetylation of FOXO4 by Sirt1 could activate the SOX9 expression and result in maintaining the ECM stability of cartilage.

Metabolomics and cancer preventive behaviors in the BC Generations Project

Metabolomics can detect metabolic shifts resulting from lifestyle behaviors and may provide insight on the relevance of changes to carcinogenesis. We used non-targeted nuclear magnetic resonance to examine associations between metabolic measures and cancer preventive behaviors in 1319 participants (50% male, mean age 54 years) from the BC Generations Project. Behaviors were dichotomized: BMI < 25 kg/m², ≥ 5 servings of fruits or vegetables/day, ≤ 2 alcoholic drinks/day for men or 1 drink/day for women and ≥ 30 min of moderate or vigorous physical activity/day. Linear regression was used to estimate coefficients and 95% confidence intervals with a false discovery rate (FDR) of 0.10. Of the 218 metabolic measures, 173, 103, 71 and 6 were associated with BMI, fruits and vegetables, alcohol consumption and physical activity. Notable findings included negative associations between glycoprotein acetyls, an inflammation-related metabolite with lower BMI and greater fruit and vegetable consumption, a positive association between polyunsaturated fatty acids and fruit and vegetable consumption and positive associations between high-density lipoprotein subclasses with lower BMI. These findings provide insight into metabolic alterations in the context of cancer prevention and the diverse biological pathways they are involved in. In particular, behaviors related to BMI, fruit and vegetable and alcohol consumption had a large metabolic impact.

Tomographic imaging with Compton PET modules: ideal case and first implementation

In our previous studies, we demonstrated that the Compton PET module, a layer structure PET detector with side readout, can provide high performance in terms of spatial/energy/timing resolution, as well as high gamma ray detection efficiency. In this study, we investigate how to translate the high performance of the detector module into good quality reconstructed tomographic images. This study is performed using GATE simulation, as well as with physical experiments. Similar detector geometry is used in the simulation and experiment: two identical 4-layer detector modules are placed with face to face distance of 56 mm. In the simulation study, each layer consists of a 1-mm-pitch pixelated crystal array. In the experimental study, each layer is a monolithic crystal, which is virtually binned into 1 mm² cells to group single events according to the gamma ray interaction locations. A customized Derenzo phantom was placed between the two detector modules. By rotating the phantom using a motorized rotary stage, data along lines of response (LORs) at different angles were collected for reconstructing the tomographic image. The same reconstruction algorithm was used for both simulation and experimental studies. The results demonstrate that the simulation study could resolve 0.8 mm rods while the experimental study was able to resolve 1.0 mm rods.

Accurate diagnosis of colorectal cancer based on histopathology images using artificial intelligence

BACKGROUND

Accurate and robust pathological image analysis for colorectal cancer (CRC) diagnosis is time-consuming and knowledge-intensive, but is essential for CRC patients' treatment. The current heavy workload of pathologists in clinics/hospitals may easily lead to unconscious misdiagnosis of CRC based on daily image analyses.

METHODS

Based on a state-of-the-art transfer-learned deep convolutional neural network in artificial intelligence (AI), we proposed a novel patch aggregation strategy for clinic CRC diagnosis using weakly labeled pathological whole-slide image (WSI) patches. This approach was trained and validated using an unprecedented and enormously large number of 170,099 patches, > 14,680 WSIs, from > 9631 subjects that covered diverse and representative clinical cases from multi-independent-sources across China, the USA, and Germany.

RESULTS

Our innovative AI tool consistently and nearly perfectly agreed with (average Kappa statistic 0.896) and even often better than most of the experienced expert pathologists when tested in diagnosing CRC WSIs from multicenters. The average area under the receiver operating characteristics curve (AUC) of AI was greater than that of the pathologists (0.988 vs 0.970) and achieved the best performance among the application of other AI methods to CRC diagnosis. Our AI-generated heatmap highlights the image regions of cancer tissue/cells.

CONCLUSIONS

This first-ever generalizable AI system can handle large amounts of WSIs consistently and robustly without potential bias due to fatigue commonly experienced by clinical pathologists. It will drastically alleviate the heavy clinical burden of daily pathology diagnosis and improve the treatment for CRC patients. This tool is generalizable to other cancer diagnosis based on image recognition.

Search for Coherent Elastic Scattering of Solar ^{8}B Neutrinos in the XENON1T Dark Matter Experiment

We report on a search for nuclear recoil signals from solar ^{8}B neutrinos elastically scattering off xenon nuclei in XENON1T data, lowering the energy threshold from 2.6 to 1.6  keV. We develop a variety of novel techniques to limit the resulting increase in backgrounds near the threshold. No significant ^{8}B neutrinolike excess is found in an exposure of 0.6  t×y. For the first time, we use the nondetection of solar neutrinos to constrain the light yield from 1-2 keV nuclear recoils in liquid xenon, as well as nonstandard neutrino-quark interactions. Finally, we improve upon world-leading constraints on dark matter-nucleus interactions for dark matter masses between 3 and 11  GeV c^{-2} by as much as an order of magnitude.

Hybridization Dynamics in CeCoIn_{5} Revealed by Ultrafast Optical Spectroscopy

We investigate the quasiparticle dynamics in the prototypical heavy fermion CeCoIn_{5} using ultrafast optical pump-probe spectroscopy. Our results indicate that this material system undergoes hybridization fluctuations before the establishment of heavy electron coherence, as the temperature decreases from ∼120  K (T^{†}) to ∼55  K (T^{*}). We reveal that the anomalous coherent phonon softening and damping reduction below T^{*} are directly associated with the emergence of collective hybridization. We also discover a distinct collective mode with an energy of ∼8  meV, which may be experimental evidence of the predicted unconventional density wave. Our findings provide important information for understanding the hybridization dynamics in heavy fermion systems.

Chiral terahertz wave emission from the Weyl semimetal TaAs

Weyl semimetals host chiral fermions with distinct chiralities and spin textures. Optical excitations involving those chiral fermions can induce exotic carrier responses, and in turn lead to novel optical phenomena. Here, we discover strong coherent terahertz emission from Weyl semimetal TaAs, which is demonstrated as a unique broadband source of the chiral terahertz wave. The polarization control of the THz emission is achieved by tuning photoexcitation of ultrafast photocurrents via the photogalvanic effect. In the near-infrared regime, the photon-energy dependent nonthermal current due to the predominant circular photogalvanic effect can be attributed to the radical change of the band velocities when the chiral Weyl fermions are excited during selective optical transitions between the tilted anisotropic Weyl cones and the massive bulk bands. Our findings provide a design concept for creating chiral photon sources using quantum materials and open up new opportunities for developing ultrafast opto-electronics using Weyl physics.

[Prognostic evaluation of nutritional indicators in patients with limited-stage small cell lung cancer]

Objective: To explore the effect of nutritional status pre-and during chemoradiotherapy on the prognosis of patients with limited- stage small cell lung cancer (LS-SCLC). Methods: We retrospectively collected medical records of 172 LS-SCLC patients undergoing concurrent chemoradiotherapy in our hospital from 2000 to 2014, with 126 males and 46 females. The data of complete blood count and hepatic and renal function were collected before initial treatment, before radiotherapy, 4 weeks during radiotherapy, and 1 month after complete of treatment. The prognostic nutritional index(PNI)was calculated. Kaplan-Meier method was used to calculate the survival rate. Log-rank test was performed used to compare the survival differences between groups. Multivariate prognostic analysis was performed using Cox regression model. Results: The median overall survival (OS) was 21 months, with median progression-free survival (PFS) of 11 months. At the beginning of treatment, patients with pre-treatment PNI ≥ 53 had significantly superior OS (median 37 vs 15 months, P=0.001) and PFS (median 16 vs 10 months, P=0.017). Patients with pre-treatment hemoglobin ≥140 g/L and <140 g/L had an median OS of 32 months and 17 months (P=0.019), and median PFS of 16 months and 9 months (P=0.040), respectively. During chemoradiation, patients with elevated hemoglobin had similar median OS compared with those had decreased hemoglobin (27 vs 18 months, P=0.063, but superior median PFS (15 vs 9 months, P=0.017). Multivariate analysis revealed that prophylactic cranial irradiation, pre-treatment hemoglobin ≥140 g/L, and pretreatment PNI ≥53 were independent predictors of OS and PFS in patients with LS-SCLC. Conclusion: Pre-treatment nutritional status and the changes of nutritional status during chemoradiotherapy is significantly associated with the prognosis of patients with limited-stage small cell lung cancer. The patients with better pre-treatment nutritional status have a better prognosis.