Advancing mass spectrometry-based chemical imaging: A noncontact continuous flow surface probe in mass spectrometry for enhanced signal detection and spatial resolution

A new method has been developed for mass spectrometric imaging of small molecules and proteins on tissue or in thinly sliced materials. A laser desorption Venturi electrospray ionization-mass spectrometer was developed for molecular imaging. This method combines laser desorption (LD) and electrospray ionization (ESI) systems before a mass spectrometer (MS). To carry out laser desorption, samples are excited with a laser from the back side of a glass substrate. The desorbed molecules or particles are then captured by a solvent flow. In the ESI system, these desorbed particles and molecules are ionized. The spray part of the solvent system consists of two capillaries: one delivers solvent to the sample plate sides to capture desorbed molecules and particles, and the other carries the solution to the mass spectrometry side using the Venturi effect. A 2D stage facilitates sampling. The system is designed to minimize the sample size after desorption using a 355 nm diode laser, and it is optimized for molecules of various sizes, including organic molecules, amino acids, and proteins. Despite challenging atmospheric conditions for protein desorption, this specialized design enables the collection of protein spectra. The amino acids and other small molecules showed high sensitivity in the MSI measurements. This innovative MS imaging system can be directly applied to real tissue systems and other plant samples to visualize the molecular level distributions.

Corrigendum to "Advancing mass spectrometry-based chemical imaging: A noncontact continuous flow surface probe in mass spectrometry for enhanced signal detection and spatial resolution" [Talanta 273 (2024) 125858]

In the statement "This innovative MS imaging system can be directly applied to real tissue systems and other plant samples to visualize the molecular level distributions." "innovative" should be read as "important".

[Analysis of the efficacy and influencing factors of sodium channel blockers in the treatment of focal epilepsy in infants under 6 months of age]

Objective: To analyze the efficacy and safety of the sodium channel blockers (SCB) antiseizure medication in the treatment of focal epilepsy in infants under 6 months of age. Methods: This was a case series study. Infants with focal epilepsy with onset within 6 months of age and treated with SCB attending the Department of Neurology of Beijing Children's Hospital from June 2016 to April 2022 were collected. The clinical data, auxiliary examinations, SCB application, efficacy, adverse reactions, and prognosis were analyzed retrospectively. Patients were grouped according to type of seizure and epileptic syndrome, age of onset and etiology. Chi square test and Fisher exact test were used to analyze the differences between groups statistically. Results: A total of 118 infants were enrolled, 65 males and 53 females, with an age of epilepsy onset of 56 (4, 114) days. Developmental and epileptic encephalopathy was diagnosed in 60 infants, 39 had self-limited neonatal and (or) infantile epilepsy, and 19 had non-syndromic focal epilepsy. Application of SCB: 106 used oxcarbazepine, 2 used lacosamide, 9 switched from oxcarbazepine to lacosamide or a combination of 2 SCB, and 1 used oxcarbazepine, lacosamide, and lamotrigine successively; oxcarbazepine was the first choice in 46 cases. The age at which SCB was applied was 103 (53, 144) days. The children were followed up for 6 months to 6 years. SCB was effective in 89 cases (75.4%), including 70 cases (59.3%) who achieved seizure freedom. The seizure-free rate was higher in the focal epilepsy only group than in the group with other seizure types (64.4% (65/101) vs. 4/17, χ²=9.99, P<0.05). The responder and seizure-free rates were all higher in the group with the onset age of >3-6 months than the group >1-3 months (84.4% (38/45) vs. 62.5% (20/32), 73.3% (33/45) vs. 46.9% (15/32), χ²=4.85 and 5.58, both P<0.05). With the exception of variants in the PRRT2 gene, those with variants in sodium or potassium channels had higher responder and seizure-free rates than those with variants in other genes(86.2% (25/29) vs. 45.5% (10/22), 62.1% (18/29) vs. 22.7% (5/22), χ²=9.65 and 7.82,both P<0.05). The most common adverse event was transient hyponatremia, which happened in 66 cases (55.9%). There were 9 cases of rash, which subsided in 6 cases after discontinuing oxcarbazepine and switching to lacosamide, and 7 cases of electrocardiogram abnormalities, which improved after withdrawing oxcarbazepine and changing to lacosamide in 1 case. Conclusion: SCB are effective and tolerable in the treatment of focal epilepsy in infants under 6 months of age, with better efficacy in patients with genetic variants of the sodium or potassium channel, focal seizures only, and seizure onset >3-6 months of age.

[Clinical characteristics and short-term prognosis of 22 cases with SARS-CoV-2 infection associated acute encephalopathy]

Objective: To investigate the clinical features and short-term prognosis of patients with SARS-CoV-2 infection associated acute encephalopathy (AE). Methods: Retrospective cohort study. The clinical data, radiological features and short-term follow-up of 22 cases diagnosed with SARS-CoV-2 infection associated AE in the Department of Neurology, Beijing Children's Hospital from December 2022 to January 2023 were retrospectively analyzed. The patients were divided into cytokine storm group, excitotoxic brain damage group and unclassified encephalopathy group according to the the clinicopathological features and the imaging features. The clinical characteristics of each group were analyzed descriptively. Patients were divided into good prognosis group (≤2 scores) and poor prognosis group (>2 scores) based on the modified Rankin scale (mRS) score of the last follow-up. Fisher exact test or Mann-Whitney U test was used to compare the two groups. Results: A total of 22 cases (12 females, 10 males) were included. The age of onset was 3.3 (1.7, 8.6) years. There were 11 cases (50%) with abnormal medical history, and 4 cases with abnormal family history. All the enrolled patients had fever as the initial clinical symptom, and 21 cases (95%) developed neurological symptoms within 24 hours after fever. The onset of neurological symptoms included convulsions (17 cases) and disturbance of consciousness (5 cases). There were 22 cases of encephalopathy, 20 cases of convulsions, 14 cases of speech disorders, 8 cases of involuntary movements and 3 cases of ataxia during the course of the disease. Clinical classification included 3 cases in the cytokine storm group, all with acute necrotizing encephalopathy (ANE); 9 cases in the excitotoxicity group, 8 cases with acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) and 1 case with hemiconvulsion-hemiplegia syndrome; and 10 cases of unclassified encephalopathy. Laboratory studies revealed elevated glutathione transaminase in 9 cases, elevated glutamic alanine transaminase in 4 cases, elevated blood glucose in 3 cases, and elevated D-dimer in 3 cases. Serum ferritin was elevated in 3 of 5 cases, serum and cerebrospinal fluid (CSF) neurofilament light chain protein was elevated in 5 of 9 cases, serum cytokines were elevated in 7 of 18 cases, and CSF cytokines were elevated in 7 of 8 cases. Cranial imaging abnormalities were noted in 18 cases, including bilateral symmetric lesions in 3 ANE cases and "bright tree appearance" in 8 AESD cases. All 22 cases received symptomatic treatment and immunotherapy (intravenous immunoglobulin or glucocorticosteroids), and 1 ANE patient received tocilizumab. The follow-up time was 50 (43, 53) d, and 10 patients had a good prognosis and 12 patients had a poor prognosis. No statistically significant differences were found between the two groups in terms of epidemiology, clinical manifestations, biochemical indices, and duration of illness to initiate immunotherapy (all P>0.05). Conclusions: SARS-CoV-2 infection is also a major cause of AE. AESD and ANE are the common AE syndromes. Therefore, it is crucial to identify AE patients with fever, convulsions, and impaired consciousness, and apply aggressive therapy as early as possible.

[Clinical features of 6 children with uridine-responsive developmental epileptic encephalopathy 50 caused by CAD gene variants]

Objective: To analyze the clinical features of children with uridine responsive developmental epileptic encephalopathy 50 (DEE50) caused by CAD gene variants. Methods: A retrospective study was conducted on 6 patients diagnosed with uridine-responsive DEE50 caused by CAD gene variants at Beijing Children's Hospital and Peking University First Hospital from 2018 to 2022. The epileptic seizures, anemia, peripheral blood smear, cranial magnetic resonance imaging (MRI), visual evoked potential (VEP), genotype features and the therapeutic effect of uridine were descriptively analyzed. Results: A total of 6 patients, including 3 boys and 3 girls, aged 3.5(3.2,5.8) years, were enrolled in this study. All patients presented with refractory epilepsy, anemia with anisopoikilocytosis and global developmental delay with regression. The age of epilepsy onset was 8.5 (7.5, 11.0) months, and focal seizures were the most common seizure type (6 cases). Anemia ranged from mild to severe. Four patients had peripheral blood smears prior to uridine administration, showing erythrocytes of variable size and abnormal morphology, and normalized at 6 (2, 8) months after uridine supplementation. Two patients suffered from strabismus, 3 patients had VEP examinations, indicating of suspicious optic nerve involvement, and normal fundus examinations. VEP was re-examined at 1 and 3 months after uridine supplementation, suggesting significant improvement or normalization. Cranial MRI were performed at 5 patients, demonstrating cerebral and cerebellar atrophy. They had cranial MRI re-examined after uridine treatment with a duration of 1.1 (1.0, 1.8) years, indicating significant improvement in brain atrophy. All patients received uridine orally at a dose of 100 mg/(kg·d), the age at initiation of uridine treatment was 1.0 (0.8, 2.5) years, and the duration of treatment was 2.4 (2.2, 3.0) years. Immediate cession of seizures was observed within days to a week after uridine supplementation. Four patients received uridine monotherapy and were seizure free for 7 months, 2.4 years, 2.4 years and 3.0 years respectively. One patient achieved seizure free for 3.0 years after uridine supplementation and had discontinued uridine for 1.5 years. Two patients were supplemented with uridine combined with 1 to 2 anti-seizure medications and had a reduced seizure frequency of 1 to 3 times per year, and they had achieved seizure free for 8 months and 1.4 years respectively. Conclusions: The clinical manifestations of DEE50 caused by CAD gene variants present a triad of refractory epilepsy, anemia with anisopoikilocytosis, and psychomotor retardation with regression, accompanied by suspected optic nerve involvement, all of which respond to uridine treatment. Prompt diagnosis and immediate uridine supplementation could lead to significant clinical improvement.

[Clinical analysis of 4 acute ischemic stroke children treated with endovascular thrombectomy]

Objective: To assess the feasibility of endovascular thrombectomy (EVT) for the treatment of acute ischemic stroke (AIS) in children. Methods: Clinical data and follow-up information of 4 AIS children who received EVT in the Department of Intervention & Hemangioma at the Children's Hospital of the Capital Institute of Pediatrics from December 2020 to June 2021 were collected retrospectively. The vascular recanalization after EVT was assessed by the modified thrombolysis in cerebral infarction (mTICI) score. Efficacy outcomes were assessed with initial and postprocedural Pediatric National Institutes of Health Stroke Scale (PedNIHSS) score, and the modified Rankin scale (mRS) score at 3 and 6 months after treatment. Safety assessments included perioperative complications and intracranial hemorrhage post-treatment. Results: A total of 5 EVT treatment were performed on 4 children with AIS, of whom 3 were male. The age of onset was 4.6, 13.8, 7.8, 8.0, 8.9 years, respectively. The time from symptom onset to initiation of EVT was 19.0, 25.0, 22.0, 4.0, 16.5 hours, respectively and all patients achieved successful recanalization of the vessel after EVT (mTICI≥2b). The PedNIHSS score was 39, 14, 25, 39, 24 before treatment and decreased to 8, 1, 12, 39, 5 at discharge. All the procedures were performed with no perioperative complications. Only 1 patient with congenital heart disease had a recurrent AIS with malignant brain oedema and brain hernia. Although the occluded vessels were successfully recanalized,the symptoms were not improved and this patient died after treatment abandonment. The other 3 patients achieved good recovery at 6 months postoperatively. The mRS score of 3 patients was 3, 1, 2 at 3 months after EVT and decreased to 2, 1, 1 at 6 months. Conclusion: EVT treatment may be feasible and safe for pediatric AIS due to large vessel occlusion even when the treatment was initiated 6 hours post stroke, but children with heart disease may have a dismal prognosis.

Quality matters: low-density lipoprotein electronegativity but not quantity determines mortality risk in acute coronary syndromes

Background

Changes in the protein composition of low-density lipoprotein (LDL) particles induce a shift in their electronegativity, a phenomenon implicated in both pro-inflammatory and pro-atherogenic signalling (1). While high levels of LDL foster the build-up of atherosclerotic plaques, and as such the susceptibility for the development of acute coronary syndromes (ACS), LDL levels assessed at the time of presentation fail to associate with fatal events following the index event (2). Experimental data suggest that altered LDL electronegativity exerts functional effects on both the myocardium and vasculature (1,3).

Purpose

We aimed to study the association between LDL electronegativity, assessed at the time of acute presentation, and all-cause mortality following the index ACS.

Methods

We designed a case-cohort study in 2'619 ACS patients prospectively recruited in the investigator-driven, multicentre SPUM-ACS study (ClinicalTrials.gov Identifier: NCT01000701). Plasma LDL levels were quantified at baseline and LDL was chromatographically resolved into 5 subfractions (L1-L5), with the L1/L5 ratio serving as a proxy for overall LDL electronegativity. By employing least-squares ordinary regression models determinants of plasma L1, L5, and the L1/5 ratio were studied, and the association with mortality of both LDL levels and its electronegativity were estimated using weighted Cox regression models.

Results

Cases and controls showed similar lipid profiles, but distinct LDL electronegativity, demonstrated by an increase in the L1/L5 ratio in cases vs. controls (P&lt;0.05; Fig. 1). The highest-ranked determinants of the L1/L5 ratio were total cholesterol, LDL, high-density lipoprotein, age and triglycerides. Higher L1/L5 ratios were associated with increased risk all-cause and cardiovascular death at both 30-day (adjusted [adj.] hazard ratio [HR], 2.35, 95% confidence interval [CI], 1.81–3.03, and 2.37, 95% CI, 1.83–3.07, per standard-deviation [SD] increase) and 1-year intervals (adj. HR, 1.88, 95% CI 1.43–2.46, and 1.81, 95% CI 1.36–2.42 per SD increase). In contrast, LDL levels were not associated with these outcomes, neither at 30-day (adj. HR, 1.20, 95% CI, 0.64–2.24, and 1.20, 95% CI, 0.64–2.56 per SD increase) nor 1-year intervals (adj. HR, 1.35, 95% CI, 0.69–2.63, and 1.25, 95% CI 0.56–2.78 per SD increase). These associations were independent of age, sex, cardiometabolic risk factors and baseline risk, as assessed by the updated GRACE score. When compared with established risk factors (hsTnT levels, BMI, Killip class, eGFR, LDL levels), the L1/L5 ratio superseded several risk factors as an independent predictor for fatal events following ACS (Fig. 2).

Conclusions

In contemporary patients with ACS, LDL electronegativity independently predicts fatal events after the acute event, while LDL levels do not. Our results suggest that LDL quality rather than quantity provides predictive utility for premature death within 1 year after the index ACS.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Swiss National Science FoundationSwiss Heart FoundationTheodor-Ida Herzog StiftungFoundation for Cardiovascular Research – Zurich Heart House

[Analysis of clinical and genetic characteristics of epilepsy associated with chromosome 16p11.2 microdeletion]

Objective: To investigate the clinical and genetic characteristics of epilepsy associated with chromosome 16p11.2 microdeletion. Methods: The patients (n=10) with 16p11.2 microdeletion found in children with epilepsy treated in Beijing Children's Hospital Affiliated to Capital Medical University from January 2018 to January 2021 were collected. The clinical manifestations, gene variations and prognosis were analyzed retrospectively. Results: A total of 10 children's data were collected, including 5 male and 5 female. The onset age of epilepsy was 4.5 (4.1,5.0) months. Regarding the seizure types, 7 cases had focal seizures with secondary generalization, 2 cases had generalized seizures, and 1 case had tonic seizures and spasms. Nine cases had cluster seizure attacks and 3 cases had status epilepticus. Seven cases had focal or multifocal epileptiform discharges in interictal electroencephalogram (EEG), 3 cases had borderline or normal EEG. Brain magnetic resonance imaging showed polymicrogyria in 1 case, paraventricular leukomalacia in 1 case, delayed myelination of white matter in 3 cases, and no obvious abnormalities in the other 5 cases. The patients were followed up for 0.5-3.5 years, with 1-3 kinds of antiepileptic drugs taken orally. The case with polymicrogyria still had seizures, however the other 9 cases had seizures controlled. The age of the last seizure attack was 8 (6, 12) months. There were 6 cases with mental and motor developmental delay before epilepsy onset. During the follow-up, 7 cases were retarded to varying degrees, while 3 cases had normal development. Regarding the genetic detection methods, 7 cases underwent whole exome sequencing, 2 cases underwent whole genome copy number variation detection, and 1 case underwent whole genome sequencing. The length of the 16p11.2 deletion in 10 cases ranged from 525 to 951 kb, and all contained the PRRT2 gene intact. Six cases were de novo variants, 1 case was inherited from the mother who had a history of convulsions in early childhood, and the source of variant was not verified in 3 cases, none of whose parents had relevant phenotype. Conclusions: The epilepsy associated with 16p11.2 microdeletion is mainly induced by the heterozygous deletion of PRRT2 gene in this region, however the phenotype is usually severe, and often combined with developmental and epileptic encephalopathy. Detection of copy number variation should be emphasized in children whose etiology is considered genetic but second-generation sequencing result is negative.

Portable particle mass spectrometer

In situ and real-time analysis of airborne particulate matter mass distributions using portable particle mass spectrometer.

Search for Lepton-Flavor Violation in Z-Boson Decays with τ Leptons with the ATLAS Detector

A search for lepton-flavor-violating Z→eτ and Z→μτ decays with pp collision data recorded by the ATLAS detector at the LHC is presented. This analysis uses 139  fb^{-1} of Run 2 pp collisions at sqrt[s]=13  TeV and is combined with the results of a similar ATLAS search in the final state in which the τ lepton decays hadronically, using the same data set as well as Run 1 data. The addition of leptonically decaying τ leptons significantly improves the sensitivity reach for Z→ℓτ decays. The Z→ℓτ branching fractions are constrained in this analysis to B(Z→eτ)<7.0×10^{-6} and B(Z→μτ)<7.2×10^{-6} at 95% confidence level. The combination with the previously published analyses sets the strongest constraints to date: B(Z→eτ)<5.0×10^{-6} and B(Z→μτ)<6.5×10^{-6} at 95% confidence level.

Investigation of solvent microparticle formation in spray ionization-quadrupole ion trap-mass spectrometry

In the present study, a new method has been developed for the real-time analysis of insource created solvent particles based on spray ionization-quadrupole ion trap-mass spectrometry (SI-QIT-MS). This is the first work in the literature reporting the formation of different solvent particles during solvent spray in mass spectrometry. The solvent particles formed from the solvent droplets are detected by a charge detector. Our ion trap system allows the measurement of a wide range particle masses. Various solvents and solvent mixtures such as water, methanol, acetone, toluene, n-butanol, water-methanol, and water-ethanol were sprayed through a cone system, and the mass of the particles was monitored by different trap frequencies and voltages. While polar molecules produce larger and more diverse particles due to their strong intermolecular forces, apolar solvents generally do not produce a significant number of particles. We obtained results using a homemade ion trap mass spectrometer capable of determining the mass of micro-sized solvent and solvent mixture particles weighing up to 10¹⁵ (Da). The instrument uses a charge detector connected to the exit of the ion trap. Simultaneous acquisition of particle mass spectra and measurement of the amount of charge in each particle allow mass assignment of each particle. Sprayed solvent particles were examined at various trap frequencies and voltages to find the best instrumental parameters for the highest trapping efficiency. The custom SI-QIT-MS instrument allows the measurement of the mass distribution of charged particles from the solvent spray.

Search for New Phenomena in Final States with Two Leptons and One or No b-Tagged Jets at sqrt[s]=13 TeV Using the ATLAS Detector

A search for new phenomena is presented in final states with two leptons and one or no b-tagged jets. The event selection requires the two leptons to have opposite charge, the same flavor (electrons or muons), and a large invariant mass. The analysis is based on the full run-2 proton-proton collision dataset recorded at a center-of-mass energy of sqrt[s]=13  TeV by the ATLAS experiment at the LHC, corresponding to an integrated luminosity of 139  fb^{-1}. No significant deviation from the expected background is observed in the data. Inspired by the B-meson decay anomalies, a four-fermion contact interaction between two quarks (b, s) and two leptons (ee or μμ) is used as a benchmark signal model, which is characterized by the energy scale and coupling, Λ and g_{*}, respectively. Contact interactions with Λ/g_{*} lower than 2.0 (2.4) TeV are excluded for electrons (muons) at the 95% confidence level, still far below the value that is favored by the B-meson decay anomalies. Model-independent limits are set as a function of the minimum dilepton invariant mass, which allow the results to be reinterpreted in various signal scenarios.

P–445 Successful live birth after repeated high-dose radiotherapy to the uterus

Study question

It has been established that radiotherapy can increase the risk of adverse pregnancy outcomes. However, there is currently no consensus on the effective sterilizing dose for adulthood uterine radiotherapy.

Summary answer

Uterine fertility preservation methods should be guided by the age of the patient receiving radiotherapy and the actual dose of radiation exposure to the uterus.

What is known already

Many experts have suggested that a high dose of radiation to the uterus is a reason to counsel patients against future pregnancy. There are major limitations to the current literature regarding off-target radiation damage to the uterus. One study reported a relative risk of 9.1 for stillbirth and neonatal death after 10 Gy doses.

Study design, size, duration

Case report and review of the literature before December 2020

Participants/materials, setting, methods

A case report of a 36-year-old female with three cancers and received repeated high-dose radiotherapy of 66 Gy and 50 Gy to the pelvis. We used a dose-volume histogram, the most widely used tool to calculate the radiation distribution within a volume of interest of the patient during radiotherapy. We determined that her uterus may have received the highest uterine radiation dosage for full-term live birth in current literature.

Main results and the role of chance

Due to iatrogenic ovarian failure, she could only use donor eggs. After endometrium preparation for 18 days, the endometrium reached 8.7 mm with a triple-line appearance. We transferred two cleavage-staged embryos and one of them implanted successfully. The course of the pregnancy was uneventful. Finally, the patient gave birth to a healthy baby via Cesarean section at 38 5/7 weeks of gestation.

Limitations, reasons for caution

It should be noted that the success of our case may not apply to all patients with cancer after they have received RT. We should inform patients about the increased risk of preterm birth, low birth weight infants, uterine rupture, and neonatal death.

Wider implications of the findings: The patient’s age and the dose of RT exposure to the uterus are important factors for the prognosis of a future pregnancy. More well-designed studies will be needed to allow future standard guidelines for uterine fertility preservation.

Trial registration number

TMU-JIRB N20204149

P–522 Cervical secretion methylation profile is associated with the success of frozen-thawed embryo transfer - a proof-of-concept study

Study question

Is cervical secretion gene methylation profile different between receptive and non-receptive endometrium and associated with implantation outcome in frozen-embryo transfer (FET) cycle?

Summary answer

The combination of candidate genes methylation profiles obtained from cervical secretion showed significant associations with pregnancy outcomes.

What is known already

Implantation failure remains a black box in reproductive medicine, and the exact mechanism of how endometrial receptivity is regulated is still unknown. Epigenetic modifications play a role in the gene expression pattern and may alter the endometrial receptivity in the human endometrium. Cervical secretion containing various implantation-related cytokines, and the gene methylation change can be used as a non-invasive molecular source that reflects the endometrium condition.

Study design, size, duration

In this retrospective case-control study, sixty-two women who entered the FET cycle (30 pregnant and 32 non-pregnant women) were enrolled.

Participants/materials, setting, methods

Cervical secretion was collected before embryo transfer from women enrolled in multicenter university-affiliated reproductive units. The DNA methylation status of six candidate genes was measured using quantitative methylation-specific PCR (qMSP). The correlation between methylation change and the pregnancy outcome was analyzed.

Main results and the role of chance

The candidate genes were selected from that associated with implantation with literature review and the original genome-wide DNA methylation data from NCBI GEO DataSets (GSE90060) which processed using bioinformatics analysis. Six candidate genes whose CpG-level methylation analysis with β-value statistically higher in receptive endometrium than in a pre-receptive endometrium were selected. All six candidate genes showed different degrees of correlation with the pregnancy outcomes. Among them, PRKAG2 methylation changes showed the highest correlation with the pregnancy outcome. A logistic regression model was used to evaluate the performance of a single gene or a combination of genes for implantation prediction. The results showed a statistically significant association between the methylation status of a combination of genes (PRKAG2, KRS1, HAND2) and the pregnancy outcome (p = 0.008), resulting in an optimal AUC of 0.7 (95% CI: 0.57 - 0.81) for implantation prediction.

Limitations, reasons for caution

The results obtained from a relatively small cohort size. A larger study and further comprehensive methylome investigations are warranted.

Wider implications of the findings: This study is the first proof-of-concept study that cervical secretion methylation profile is associated with implantation outcome in a FET cycle, and showed potential as a non-invasive method for implantation prediction.

Trial registration number

non applicable

O-086 End-to-end deep learning for recognition of ploidy status using time-lapse videos

Study question

Our Retrospective study is to investigate an end-to-end deep learning model in identifying ploidy status through raw time-lapse video.

Summary answer

Our deep learning model demonstrates a proof of concept and potential in recognizing the ploidy status.

What is known already

Since the time-lapse system has been introduced into the IVF lab, the relationship between morphogenetic and ploidy status has been often discussed. However, the result has not yet reached a united conclusion due to some limitations such as human labeling. Besides the statistical approach, deep learning models have been utilized for ploidy prediction. As such approaches are single image-based, the performance remains unpromising as previous statistical-based research. Therefore, in order to move further toward clinical application, better research design and approach are needed.

Study design, size, duration

A retrospective analysis of the time-lapse videos and chromosomal status from 690 biopsied blastocysts cultured in a time-lapse incubator (EmbryoScope+, Vitrolife) between January 2017 and August 2018 in the Lee Women’s Hospital were assessed. The ploidy status of the blastocyst was derived from the PGT-A using high-resolution next-generation sequencing (hr-NGS). Embryo videos were obtained after normal fertilization through the intracytoplasmic sperm injection or conventional insemination.

Participants/materials, setting, methods

By randomly dividing the data into 80% and 20%, we developed our deep learning model based on Two-Stream Inflated 3D ConvNets(I3D) network. This model was trained by the 80% time-lapse videos and the PGT-A result. The remaining 20% has been tested by feeding the time-lapse video as input and the PGT-A prediction as output. Ploidy status was classified as Group 1 (aneuploidy) and Group 2 (euploidy and mosaicism).

Main results and the role of chance

Time-lapse videos were divided into 3-time partitions: day 1, day 1 to 3, and day 1 to 5. Deep learning models have been fed by RGB and optical flow. Combining 3 different time partitions with RGB, optical flow, and fused result from RGB and optical flow, we received nine sets of test results. According to the results, the longest time partition with the fusion method has the highest AUC result as 0.74, which appeared higher than the other eight experimental settings with a maximum increase of 0.17.

Limitations, reasons for caution

The present study is retrospective and future prospective research would help us to identify more key factors and improve this model. In addition, expanding sample size combined with cross-centered validation will also be considered in our future approach.

Wider implications of the findings

Group 1 and Group 2 approach provided deselection of aneuploidy embryos, while future deep learning approaches toward high mosaicism, low mosaicism, and euploidy will be needed, in order to provide a better clinical application.

Trial registration number

CS18082

Search for Displaced Leptons in sqrt[s]=13 TeV pp Collisions with the ATLAS Detector

A search for charged leptons with large impact parameters using 139  fb^{-1} of sqrt[s]=13  TeV pp collision data from the ATLAS detector at the LHC is presented, addressing a long-standing gap in coverage of possible new physics signatures. Results are consistent with the background prediction. This search provides unique sensitivity to long-lived scalar supersymmetric lepton partners (sleptons). For lifetimes of 0.1 ns, selectron, smuon, and stau masses up to 720, 680, and 340  GeV, respectively, are excluded at 95% confidence level, drastically improving on the previous best limits from LEP.

Monitoring Silver(I)-Insulin Complexes with Electrospray Ionization Quadrupole Ion Trap Mass Spectrometry

Ag(I)-insulin complex formation was investigated using electrospray quadrupole ion trap mass spectrometry (ESI-QIT-MS), and Ag(I) ion binding to an insulin molecule was evaluated. The Ag(I) binding ratios were measured in the range of pH 3-8. The highest binding ratio of the Ag(I) ions was obtained at pH 7. Spectrometric titration was carried out at varied molar ratios of Ag(I) ions to insulin from 20/1 to 250/1. It was observed that four Ag(I) ions were bound effectively to an insulin molecule to form Ag(I)_1-4-insulin complexes. The formation equilibrium constants of Ag(I)_1-4-insulin complexes were calculated from the ESI-QIT-MS peak intensities. The equilibrium constants were found as K_f1 = (2.92 ± 0.18) × 10⁴ M^-1, K_f2 = (1.03 ± 0.07) × 10⁴ M^-1, K_f3 = (6.67 ± 0.46) × 10³ M^-1, and K_f4 = (2.00 ± 0.16) × 10³ M^-1. The tandem MS/MS spectroscopies were studied to evaluate the stability of the Ag(I) complexes. The different flow rates with nano-ESI were performed to determine the binding of Ag(I) ions in solution or gas phase. In conclusion, it was observed that the Ag(I) ion forms stable Ag(I)_1-4-complexes with high formation equilibrium constants.

Development of a focused high-energy macromolecular ion beam

In this work, we report the development of a focused macromolecular ion beam with kinetic energy of up to 110 keV. The system consists of a quadrupole ion trap (QIT), einzel lens and linear accelerator (LINAC). Based on the combination of matrix-assisted laser desorption ionization (MALDI) and quadrupole ion trapping (QIT), ions were desorbed from the surface and trapped with an ion trap to form biomolecular ion packets. Positive- and negative-pulsed voltages were applied on each end-cap electrode of the QIT to extract the ion packets and form an ion beam that was subsequently focused via an einzel lens and accelerated by stepwise pulsed voltages. The tabletop instrument was designed and successfully demonstrated via measurements of molecular ions of insulin, cytochrome c and bovine serum albumin (BSA) with mass-to-charge ratios (m/z) ranging from ∼5.8 to 66.5 k. This is the first report of both a focused and high-kinetic-energy protein ion beam. In addition, both secondary ions and electrons were observed from the surface by hypervelocity ion beam bombardment. This focused macromolecular ion beam has demonstrated its potential in the study of interactions between large molecular ions with other molecules either in the gas phase or upon a surface.

[The etiology of 340 infants with early-onset epilepsy]

Objective: To investigate the etiology of epilepsy onset before 6 months old and improve clinical understanding. Methods: The medical history, electroencephalogram, brain imaging, genetic examination and other clinical data of 340 patients who were diagnosed with epilepsy with onset under 6 months of age and were hospitalized in the Department of Neurology, Beijing Children's Hospital, Capital Medical University between January 2017 and December 2018 were retrospectively analyzed. Rank sum test was used to compare the ages of onset of different etiologic groups. Results: Of the 340 patients, 196 were males and 144 were females. The age of onset was 90.5 (48.0, 135.5) days. In the 250 (73.5%) underwent genetic test, 103 (41.2%) had pathogenic or likely pathogenic variants, involving 43 single gene variants and 2 chromosomal abnormalities. Seventy-nine patients (23.2%) had genetic etiology, 66 (19.4%) had structural etiology, 19 (5.6%) had metabolic etiology, 13 (3.8%) had multiple etiologies, and 163 (47.9%) had unknown etiology. In the 79 cases with genetic etiology, 30 single gene variants were detected, including 19 cases of PRRT2, 10 cases of KCNQ2, 7 cases of SCN1A, 6 cases of SCN2A, 6 cases of STXBP1, 5 cases of CDKL5, 2 cases of ARX, and 1 case of each of 23 gene variants. Two cases had chromosomal abnormalities which were 21-trisomy and 16p11.2 microdeletion syndrome respectively. Among the 66 cases with structural etiologies, 37 cases had acquired factors such as perinatal brain injury, 28 cases had congenital factors such as cortical malformation and 1 case was perinatal brain injury combined megalencephaly. The onset age of genetic etiology was 95 (26, 128) days, that of structural etiology was 90 (58, 30) days, and that of metabolic etiology was 57 (30, 90) days. The onset age of metabolic etiology was earlier than that of structural etiology (U=436.500, P=0.044). Conclusions: Genetic etiology is the most common defined etiology of infants with early-onset epilepsy aged 0-6 months, and there are certain differences in the age of onset between different etiologies. Proper application of genetic test is helpful to identify the etiology and guide treatment.

Longitudinal Flow Decorrelations in Xe+Xe Collisions at sqrt[s_{NN}]=5.44 TeV with the ATLAS Detector

The first measurement of longitudinal decorrelations of harmonic flow amplitudes v_{n} for n=2-4 in Xe+Xe collisions at sqrt[s_{NN}]=5.44  TeV is obtained using 3  μb^{-1} of data with the ATLAS detector at the LHC. The decorrelation signal for v_{3} and v_{4} is found to be nearly independent of collision centrality and transverse momentum (p_{T}) requirements on final-state particles, but for v_{2} a strong centrality and p_{T} dependence is seen. When compared with the results from Pb+Pb collisions at sqrt[s_{NN}]=5.02  TeV, the longitudinal decorrelation signal in midcentral Xe+Xe collisions is found to be larger for v_{2}, but smaller for v_{3}. Current hydrodynamic models reproduce the ratios of the v_{n} measured in Xe+Xe collisions to those in Pb+Pb collisions but fail to describe the magnitudes and trends of the ratios of longitudinal flow decorrelations between Xe+Xe and Pb+Pb. The results on the system-size dependence provide new insights and an important lever arm to separate effects of the longitudinal structure of the initial state from other early and late time effects in heavy-ion collisions.

Search for Dark Matter Produced in Association with a Dark Higgs Boson Decaying into W^{±}W^{∓} or ZZ in Fully Hadronic Final States from sqrt[s]=13 TeV pp Collisions Recorded with the ATLAS Detector

Several extensions of the Standard Model predict the production of dark matter particles at the LHC. An uncharted signature of dark matter particles produced in association with VV=W^{±}W^{∓} or ZZ pairs from a decay of a dark Higgs boson s is searched for using 139  fb^{-1} of pp collisions recorded by the ATLAS detector at a center-of-mass energy of 13 TeV. The s→V(qq[over ¯])V(qq[over ¯]) decays are reconstructed with a novel technique aimed at resolving the dense topology from boosted VV pairs using jets in the calorimeter and tracking information. Dark Higgs scenarios with m_{s}>160  GeV are excluded.

Unusual Near-Horizon Cosmic-Ray-like Events Observed by ANITA-IV

ANITA's fourth long-duration balloon flight in 2016 detected 29 cosmic-ray (CR)-like events on a background of 0.37_{-0.17}^{+0.27} anthropogenic events. CRs are mainly seen in reflection off the Antarctic ice sheets, creating a phase-inverted waveform polarity. However, four of the below-horizon CR-like events show anomalous noninverted polarity, a p=5.3×10^{-4} chance if due to background. All anomalous events are from locations near the horizon; ANITA-IV observed no steeply upcoming anomalous events similar to the two such events seen in prior flights.

Medium-Induced Modification of Z-Tagged Charged Particle Yields in Pb+Pb Collisions at 5.02 TeV with the ATLAS Detector

The yield of charged particles opposite to a Z boson with large transverse momentum (p_{T}) is measured in 260  pb^{-1} of pp and 1.7  nb^{-1} of Pb+Pb collision data at 5.02 TeV per nucleon pair recorded with the ATLAS detector at the Large Hadron Collider. The Z boson tag is used to select hard-scattered partons with specific kinematics, and to observe how their showers are modified as they propagate through the quark-gluon plasma created in Pb+Pb collisions. Compared with pp collisions, charged-particle yields in Pb+Pb collisions show significant modifications as a function of charged-particle p_{T} in a way that depends on event centrality and Z boson p_{T}. The data are compared with a variety of theoretical calculations and provide new information about the medium-induced energy loss of partons in a p_{T} regime difficult to measure through other channels.

[Pediatric autoimmune encephalitis associated with anti-glutamic acid decarboxylase 65 antibody: two cases report and literature review]

Objective: To investigate the clinical features and prognosis of pediatric autoimmune encephalitis associated with anti-glutamic acid decarboxylase 65 (GAD65) antibody. Methods: Clinical data of 2 patients diagnosed as autoimmune encephalitis associated with anti-GAD65 antibody at Department of Neurology, Beijing Children's Hospital in 2019 were analyzed retrospectively. A literature search with "anti-GAD65 antibody""encephalitis""epilepsy" or "cerebellar ataxia" as key words was conducted at China National Knowledge Infrastructure, Wanfang Data Knowledge Service Platform and PubMed (up to January 2020). The clinical features and prognosis of pediatric cases with complete clinical data were retrieved and summarized. Results: Two patients with positive anti-GAD65 antibody of serum and cerebrospinal fluid were both females. The onset age of case 1 was 57 months and her main clinical manifestations were fever and unconsciousness. The cranial magnetic resonance imaging (MRI) showed diffuse T2 weighted imaging (T2WI) abnormal signals, and the electroencephalogram (EEG) showed slow waves. The onset age of case 2 was 80 months and her main clinical manifestations of were recurrent focal seizures, memory loss, and headache. The MRI showed high T2WI signal in bilateral hippocampus, and the EEG showed abnormal discharge involving the temporal area. Both cases were treated with methylprednisolone and intravenous immunoglobulin, the short-term symptoms of them were both improved. They were followed up for 6 months and 1 year respectively, the case 1 recovered completely, and the case 2 still had focal seizures. Six English reports which included 6 cases were retrieved. Together with these 2 cases, a total of 8 cases were analyzed. The clinical symptoms included seizures (6 cases), memory loss (4 cases), loss of consciousness (3 cases), behavioral abnormalities (3 cases), cognitive impairment (2 cases), headache (2 cases), autonomic symptoms (1 case), ataxia (1 case), dysphagia (1 case), and aphasia (1 case). There were 5 cases with cranial MRI abnormalities in the acute phase or sub-acute phase, of whom 3 cases had the limbic system involvement, and 2 cases were mainly had extra limbic area involvement. Three cases had hippocampal atrophy or sclerosis during follow-up. All 8 patients were treated with immunotherapy. After immunotherapy, all patients had short-term improvement. Follow-up for 6 months to 6 years showed that 3 cases with extra limbic encephalitis improved to baseline levels, and 5 limbic encephalitis cases had poor outcomes, including 1 death and 4 cases still had focal epilepsy. Conclusions: Pediatric anti-GAD65 antibody associated autoimmune encephalitis is a rare but treatable disease, including limbic encephalitis and extra limbic encephalitis. The most common clinical manifestations are seizures and memory impairment. Early diagnosis and immunotherapy can improve the symptoms in a short time. But patients with limbic encephalitis often had refractory epilepsy in the chronic phase, and have a poor long-term outcome.

Observation and Measurement of Forward Proton Scattering in Association with Lepton Pairs Produced via the Photon Fusion Mechanism at ATLAS

The observation of forward proton scattering in association with lepton pairs (e^{+}e^{-}+p or μ^{+}μ^{-}+p) produced via photon fusion is presented. The scattered proton is detected by the ATLAS Forward Proton spectrometer, while the leptons are reconstructed by the central ATLAS detector. Proton-proton collision data recorded in 2017 at a center-of-mass energy of sqrt[s]=13  TeV are analyzed, corresponding to an integrated luminosity of 14.6  fb^{-1}. A total of 57 (123) candidates in the ee+p (μμ+p) final state are selected, allowing the background-only hypothesis to be rejected with a significance exceeding 5 standard deviations in each channel. Proton-tagging techniques are introduced for cross-section measurements in the fiducial detector acceptance, corresponding to σ_{ee+p}=11.0±2.6(stat)±1.2(syst)±0.3(lumi) and σ_{μμ+p}=7.2±1.6(stat)±0.9(syst)±0.2(lumi)  fb in the dielectron and dimuon channel, respectively.

Comprehensive Workflow for Mapping Disulfide Linkages Including Free Thiols and Error Checking by On-Line UV-Induced Precolumn Reduction and Spiked Control

Mapping highly complicated disulfide linkages and free thiols via liquid chromatography-tandem mass spectrometry (LC-MS²) is challenging because of the difficulties in optimizing sample preparation to acquire critical MS data and detecting mispairings. Herein, we report a highly efficient and comprehensive workflow using an on-line UV-induced precolumn reduction tandem mass spectrometry (UV-LC-MS²) coupled with two-stage data analysis and spiked control. UV-LC-MS² features a gradient run of acetonitrile containing a tunable percentage of photoinitiators (acetone/alcohol) that drives the sample to the MS through a UV-flow cell and reverse phase column to separate UV-induced products for subsequent fragmentation via low energy collision-induced dissociation. This allowed the alkylated thiol-containing and UV-reduced cysteine-containing peptides to be identified by a nontargeted database search. Expected or unexpected disulfide/thiol mapping was then carried out based on the search results, and data were derived from partially reduced species by photochemical reaction. Complete assignments of native and scrambled disulfide linkages of insulin, α-lactalbumin, and bovine serum albumin (BSA) as well as the free C34-BSA were demonstrated using none or single enzyme digestion. This workflow was applied to characterize unknown disulfide/thiol patterns of the recombinant cyclophilin 1 monomer (rTvCyP1 mono) from the human pathogen Trichomonas vaginalis. α-Lactalbumin was judiciously chosen as a spiked control to minimize mispairings due to sample preparation. rTvCyP1 was determined to contain a high percentage of thiol (>80%). The rest of rTvCyP1 mono were identified to contain two disulfide/thiol patterns, of which C41-C169 linkage was confirmed to exist as C53-C181 in rTvCyP2, a homologue of rTvCyP1. This platform identifies heterogeneous protein disulfide/thiol patterns in a de-novo fashion with artifact control, opening up an opportunity to characterize crude proteins for many applications.

Search for Heavy Resonances Decaying into a Photon and a Hadronically Decaying Higgs Boson in pp Collisions at sqrt[s]=13 TeV with the ATLAS Detector

This Letter presents a search for the production of new heavy resonances decaying into a Higgs boson and a photon using proton-proton collision data at sqrt[s]=13  TeV collected by the ATLAS detector at the LHC. The data correspond to an integrated luminosity of 139  fb^{-1}. The analysis is performed by reconstructing hadronically decaying Higgs boson (H→bb[over ¯]) candidates as single large-radius jets. A novel algorithm using information about the jet constituents in the center-of-mass frame of the jet is implemented to identify the two b quarks in the single jet. No significant excess of events is observed above the expected background. Upper limits are set on the production cross-section times branching fraction for narrow spin-1 resonances decaying into a Higgs boson and a photon in the resonance mass range from 0.7 to 4 TeV, cross-section times branching fractions are excluded between 11.6 fb and 0.11 fb at a 95% confidence level.

[Clinical characteristics and prognostic analysis of 458 children with high-risk neuroblastoma in a single center]

Objective: To summarize the clinical characteristics of high-risk neuroblastoma (HR-NB) in a single center, analyze the prognostic factors of HR-NB. Methods: The clinical data of children with HR-NB who were treated and followed up at the hematology-oncology center of Beijing Children's Hospital from February 1, 2007 to June 30, 2018 were analyzed retrospectively. The clinical features were summarized. Kaplan-Meier method was used for survival analysis and Cox regression was used to analyze the prognostic factors. The last follow-up time was June 30, 2019. Results: A total of 458 children with HR-NB were enrolled in this study, including 265 males (57.9%) and 193 females (42.1%), the age at diagnosis was 40.0 months (4.5-148.0 months), the follow-up time was 22.0 months (0.2-138.0 months) and the time of tumor progression or recurrence was 15 months (1-72 months). The 5-year event-free survival (EFS) rate was (31.2±2.6)% and the 5-year overall survival (OS) rate was (43.9±3.2)%. The 5-year EFS rate and 5-year OS rate in 142 hematopoietic stem cell transplantation (HSCT) patients with bone marrow metastases were better than that in 196 non-transplantation cases with bone marrow metastases ((26.5±4.5)% vs. (25.1±3.6)%, χ²=13.773, P=0.001; (38.1±5.5)% vs. (35.7±4.7)%, χ²=9.235, P=0.002); 128 transplantation patients with bone metastases had higher 5-year EFS rate and 5-year OS rate than 188 non-transplantation cases with bone metastases ((28.5±5.0)% vs. (26.7±3.8)%, χ²=10.222, P=0.001; (37.1±6.0)% vs. (36.2±4.8)%, χ²=7.843, P=0.005). The 5-year EFS rate was higher in 37 HSCT patients with MYCN amplification than in 49 non-transplantation cases with MYCN amplification ((26.8±8.0) % vs. (20.5±6.4) %, χ²=5.732, P=0.017). No significant difference was found in 5-years OS rate between transplantation group with MYCN amplification and non-transplantation group with MYCN amplification ((31.4±8.6) % vs. (26.2±7.4) %, χ²=3.230, P=0.072). Univariate survival analysis showed that lactate dehydrogenase (LDH)≥1 500 U/L was associated with poor prognosis of patients with MYCN amplification (χ²=6.960, P=0.008). Multivariate Cox analysis showed bone marrow metastasis and LDH≥1 500 U/L were independent risk factors for poor prognosis of patients with non-MYCN amplification (HR=2.427, 1.618;95%CI：1.427-4.126, 1.275-2.054, P<0.05) for both comparisons. Conclusions: LDH≥1 500 U/L was the poor prognostic factor for patients with MYCN amplification. The bone marrow metastasis and LDH≥1 500 U/L were the poor prognostic factors for HR-NB patients with non-MYCN amplification. HSCT can improve the prognosis of patients with bone or bone marrow metastasis. It can also retard the time of progression or recurrence for patients with MYCN amplification.

Targeted drug delivery using an aptamer against shared tumor-specific peptide antigen of MAGE-A3

We developed a DNA aptamer, Ap52, against the shared tumor-specific MAGE-A3_111-125 peptide antigen that was used to target multiple types of cancer cells. Here we report the in vivo study of mice implanted with pancreatic tumor cells AsPC-1, which demonstrates accumulation of phosphorothioate-modified Ap52 (ThioAp52) at the xenograft tumor following either intravenous or in situ injection. When complexed with antitumor drug doxorubicin (Dox), ThioAp52 achieves targeted delivery to four types of cancer cells, including breast, oral, pancreatic, and skin. Image analysis shows that ThioAp52-Dox complex selectively enters cancer cells, while free Dox is taken up by all cell lines. The cytotoxicity of ThioAp52-Dox for cancer cells is enhanced as compared to that for the corresponding normal/noncancerous cells. These results indicate that this aptamer against shared tumor-specific antigen can be a potential delivery vehicle for therapeutics to treat multiple cancers.

Search for Higgs Boson Decays into a Z Boson and a Light Hadronically Decaying Resonance Using 13 TeV pp Collision Data from the ATLAS Detector

A search for Higgs boson decays into a Z boson and a light resonance in two-lepton plus jet events is performed, using a pp collision dataset with an integrated luminosity of 139  fb^{-1} collected at sqrt[s]=13  TeV by the ATLAS experiment at the CERN LHC. The resonance considered is a light boson with a mass below 4 GeV from a possible extended scalar sector or a charmonium state. Multivariate discriminants are used for the event selection and for evaluating the mass of the light resonance. No excess of events above the expected background is found. Observed (expected) 95% confidence-level upper limits are set on the Higgs boson production cross section times branching fraction to a Z boson and the signal resonance, with values in the range 17-340 pb (16_{-5}^{+6}-320_{-90}^{+130}  pb) for the different light spin-0 boson mass and branching fraction hypotheses, and with values of 110 and 100 pb (100_{-30}^{+40} and 100_{-30}^{+40}  pb) for the η_{c} and J/ψ hypotheses, respectively.

Enhancement of fucosylated N-glycan isomer separation with an ultrahigh column temperature in porous graphitic carbon liquid chromatography-mass spectrometry

Due to the heterogeneous and isomeric nature of glycans, the development of an advanced separation of distinct glycan isomers is essential for glycan research and application. In this study, we utilized porous graphite carbon (PGC) chromatography for the separation of isomeric oligosaccharides without reduction or chemical derivatization at 190 °C in a custom-built heating oven. Furthermore, the fine structures of glycan isomers could be identified by using ultrahigh temperature PGC liquid chromatography mass spectrometry (UHT-PGC-LCMS). A nonreduced hydrolyzed dextran was applied to verify the performance of UHT-PGC. When the temperature of the PGC column was increased from 25 to 190 °C, the liquid chromatography separation power of the nonreduced dextran ladder significantly increased. The advantage of the UHT-PGC column was its high peak capacity with gradient elution in 10 min at 190 °C, 6700 psi, and a 250 μL/min flow rate for native glycan analysis. Four synthetic Lewis antigen isomers were used to elucidate the separation effectiveness in UHT-PGC. Moreover, mass spectrometry-based sequencing to generate specific diagnostic ions from the four synthetic Lewis antigens was used to predict isomeric glycans based on the relative intensity ratio (RIR) of diagnostic ions. The intensities of the diagnostic ions of synthetic isomers were used to identify each isomer of the fucosylated glycan. The results clearly showed that terminal Lewis A and X residues were in the 3- and 6-arms of N-glycan, respectively.

Spatial orientation in virtual environment compared to real-world

Virtual reality (VR) is popular across many disciplines and has been increasingly used in sports as a training tool lately. However, it is not clear whether the spatial orientation of humans works equally within VR and in the real-world. In this paper, two studies are presented, in which natural body movements were allowed and demanded. Firstly, a series of verbal and walking distance estimation tests were conducted in both the virtual and the real environment. The non-parametric Friedman test with pairwise comparisons showed no significant differences neither in verbal nor in walking distance estimations between the conditions (all p > 0.05). However, shorter distances (0.9-1.5 m) were estimated more precisely than larger distances (2.6-2.8 m) in both environments. Secondly, a self-developed route recall test to examine the spatial orientation was performed in the virtual and the real environment. The participants visually perceived the predefined route and were instructed to follow these routes with their eyes blindfolded and afterward to return to their starting position. Between the ending and the starting position, no difference between the two environments was observed (p > 0.05). Based on these two studies, the performance of the human spatial orientation preliminarily verified the same in a virtual and real environment.

Dijet Resonance Search with Weak Supervision Using sqrt[s]=13 TeV pp Collisions in the ATLAS Detector

This Letter describes a search for narrowly resonant new physics using a machine-learning anomaly detection procedure that does not rely on signal simulations for developing the analysis selection. Weakly supervised learning is used to train classifiers directly on data to enhance potential signals. The targeted topology is dijet events and the features used for machine learning are the masses of the two jets. The resulting analysis is essentially a three-dimensional search A→BC, for m_{A}∼O(TeV), m_{B},m_{C}∼O(100  GeV) and B, C are reconstructed as large-radius jets, without paying a penalty associated with a large trials factor in the scan of the masses of the two jets. The full run 2 sqrt[s]=13  TeV pp collision dataset of 139  fb^{-1} recorded by the ATLAS detector at the Large Hadron Collider is used for the search. There is no significant evidence of a localized excess in the dijet invariant mass spectrum between 1.8 and 8.2 TeV. Cross-section limits for narrow-width A, B, and C particles vary with m_{A}, m_{B}, and m_{C}. For example, when m_{A}=3  TeV and m_{B}≳200  GeV, a production cross section between 1 and 5 fb is excluded at 95% confidence level, depending on m_{C}. For certain masses, these limits are up to 10 times more sensitive than those obtained by the inclusive dijet search. These results are complementary to the dedicated searches for the case that B and C are standard model bosons.

CP Properties of Higgs Boson Interactions with Top Quarks in the tt[over ¯]H and tH Processes Using H→γγ with the ATLAS Detector

A study of the charge conjugation and parity (CP) properties of the interaction between the Higgs boson and top quarks is presented. Higgs bosons are identified via the diphoton decay channel (H→γγ), and their production in association with a top quark pair (tt[over ¯]H) or single top quark (tH) is studied. The analysis uses 139  fb^{-1} of proton-proton collision data recorded at a center-of-mass energy of sqrt[s]=13  TeV with the ATLAS detector at the Large Hadron Collider. Assuming a CP-even coupling, the tt[over ¯]H process is observed with a significance of 5.2 standard deviations. The measured cross section times H→γγ branching ratio is 1.64_{-0.36}^{+0.38}(stat)_{-0.14}^{+0.17}(sys)  fb, and the measured rate for tt[over ¯]H is 1.43_{-0.31}^{+0.33}(stat)_{-0.15}^{+0.21}(sys) times the Standard Model expectation. The tH production process is not observed and an upper limit on its rate of 12 times the Standard Model expectation is set. A CP-mixing angle greater (less) than 43 (-43)° is excluded at 95% confidence level.

Search for Heavy Higgs Bosons Decaying into Two Tau Leptons with the ATLAS Detector Using pp Collisions at sqrt[s]=13 TeV

A search for heavy neutral Higgs bosons is performed using the LHC Run 2 data, corresponding to an integrated luminosity of 139  fb^{-1} of proton-proton collisions at sqrt[s]=13  TeV recorded with the ATLAS detector. The search for heavy resonances is performed over the mass range 0.2-2.5 TeV for the τ^{+}τ^{-} decay with at least one τ-lepton decaying into final states with hadrons. The data are in good agreement with the background prediction of the standard model. In the M_{h}^{125} scenario of the minimal supersymmetric standard model, values of tanβ>8 and tanβ>21 are excluded at the 95% confidence level for neutral Higgs boson masses of 1.0 and 1.5 TeV, respectively, where tanβ is the ratio of the vacuum expectation values of the two Higgs doublets.

Flow Chemistry System for Carbohydrate Analysis by Rapid Labeling of Saccharides after Glycan Hydrolysis

This study demonstrates the utilization of a flow chemistry system for continuous glycan hydrolysis and saccharide labeling to assist with the existing methods in glycan structural analysis. Acidic hydrolysis of glycans could be accelerated in a flow system. Aldoses and α-ketoacid-type saccharides were effectively labeled with naphthalene-2,3-diamine (NADA) at 60 °C for 10 min to form the fluorescent naphthimidazole (NAIM) and quinoxalinone (QXO) derivatives, respectively. The NADA-labeled derivatives improved the structural determination and composition analysis for their parent saccharides by using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS), liquid chromatography mass spectrometry (LC-MS), and nuclear magnetic resonance (NMR). Furthermore, this protocol was applied to determine the SA–Gal–Glc sequence of GM3-sugar out of six possible permutations.

Measurement of the Lund Jet Plane Using Charged Particles in 13 TeV Proton-Proton Collisions with the ATLAS Detector

The prevalence of hadronic jets at the LHC requires that a deep understanding of jet formation and structure is achieved in order to reach the highest levels of experimental and theoretical precision. There have been many measurements of jet substructure at the LHC and previous colliders, but the targeted observables mix physical effects from various origins. Based on a recent proposal to factorize physical effects, this Letter presents a double-differential cross-section measurement of the Lund jet plane using 139  fb^{-1} of sqrt[s]=13  TeV proton-proton collision data collected with the ATLAS detector using jets with transverse momentum above 675 GeV. The measurement uses charged particles to achieve a fine angular resolution and is corrected for acceptance and detector effects. Several parton shower Monte Carlo models are compared with the data. No single model is found to be in agreement with the measured data across the entire plane.

[Epidemiological investigation on clinical characteristics of 801 inpatients with chronic wounds]

Objective: To analyze the clinical characteristics of 801 inpatients with chronic wounds. Methods: The medical records of patients with chronic wounds who were admitted to the General Hospital of Southern Theater Command of PLA (hereinafter referred to as the author's unit) from January 2013 to December 2017, including gender, occupation, wound type, age, department distribution, recovery status, recovery time, hospitalization time, hospitalization cost, treatment method, clinical outcome, and medical expenses were retrospectively analyzed. Data were statistically analyzed with chi-square test, Fisher's exact probability test, and Kruskal-Wallis H test. Results: Of 245 037 inpatients admitted to the author's unit within 5 years, 801 (3.3‰) patients with chronic wounds met the inclusion criteria. The composition ratio of chronic wound patients during the 5 years was 2.4‰ (106/44 230)-3.9‰ (191/49 342). Among chronic wound patients, there were 527 males and 274 females, with manual labor, retired, and unemployed patients accounted for a large proportion. The main type of chronic wound was unhealed wound after surgery, accounting for 28.2% (226/801), followed by diabetic wound, accounting for 22.7% (182/801) and traumatic wound, accounting for 16.5% (132/801). There was statistically significant difference in gender distribution of patients with different types of chronic wounds (χ(2)=28.236, P<0.05). The main types of wound in male patients were unhealed wound after surgery, diabetic wound, and traumatic wound, while the main types of wound in female patients were diabetic wound and unhealed wound after surgery. There was statistically significant difference in the age group distribution of patients with different types of chronic wounds (P<0.01). Patients aged 41-60 years had a high incidence of unhealed wound after surgery and traumatic wound, and patients aged 61-80 years had a high incidence of diabetic wound. Patients with chronic wounds in department of orthopedics had the highest recovery rate, followed by comprehensive department. There were statistically significant differences in hospitalization time and hospitalization cost of patients with chronic wounds admitted to different departments (χ(2)=47.390, 107.390, P<0.05). There were no statistically significant differences in cure status and cure time of patients with chronic wounds admitted to different departments (χ(2)=7.163, 15.510, P>0.05). Patients treated with surgery in combination with drug had higher recovery rates than patients given other treatment methods. There was no statistically significant difference in the cure rate of patients with different treatment methods (χ(2)=7.600, P>0.05). There were statistically significant differences in cure time, hospitalization cost, and hospitalization time of patients given different treatment methods (χ(2)=38.067, 130.520, 130.890, P<0.05). There were no statistically significant differences in hospitalization cost and hospitalization time of patients with different clinical outcomes (χ(2)=2.070, 5.790, P>0.05). The total medical cost of 801 patients with chronic wounds was about 47 million yuan, of which the total hospitalization cost per capita was 50, 725 yuan, with a minimum of 1 164 yuan and a maximum of about 1.16 million yuan per capita, and with drug and materials costs accounted for high proportions of the total cost. Conclusions: Patients with chronic wounds in the author's unit are mainly physical labor and middle-aged and elderly people, with more male patients than female patients. The main type of wound is unhealed wound after surgery, which brings serious economic burden to the patients and the society. Therefore, it is necessary to strengthen the public knowledge about chronic wounds and improve the awareness of prevention and treatment.

A portable multiple ionization source biological mass spectrometer

In the past, matrix-assisted laser desorption/ionization (MALDI) and electrospray ionization (ESI), used for large biomolecule detection, were usually installed in two separate mass spectrometers. In this study, they were equipped in the same mass spectrometer. This portable biological mass spectrometer has multiple ionization capabilities in the same mass spectrometer and shares the same mass analyzer and detector. This mass spectrometer can be operated under low vacuum (∼10-3 Torr) and can use air as the buffer gas. Therefore, the demand for pumping is reduced and rare gas feeding is no longer essential. A small scroll pump, employed to assist a miniature turbo pump, is sufficient to maintain the operational pressure. The mass spectra of biomolecules were obtained using frequency scanning instead of voltage ramping. Therefore, a wider mass-to-charge ratio (m/z) range was achieved. Furthermore, the design also couples a conversion dynode with a channeltron to enhance the mass detection range. This homemade mass spectrometer has the capability to measure charged particles with very large m/z values (m/z > 100 000). The concentrations of the studied compounds (angiotensin, insulin, cytochrome C, bovine serum albumin (BSA), immunoglobulin G, and immunoglobulin A) are from 5 femtomole to 100 picomole, and the mass resolutions are from 30 to 260. The mass range of this portable mass spectrometer was comparable with a commercial linear time-of-flight mass spectrometer owing to the use of the frequency scan.

Abstract A16: Metformin is a potential nontoxic adjuvant to enhance the efficacy of non-PDL1/PD-1 targeting immune therapies

Investigations into various immunotherapies combined with conventional anticancer drugs are ongoing to increase therapeutic efficacy. However, combination therapy generally increases the risk of side effects. To achieve high efficacy with minimal side effects, nontoxic adjuvants should be identified and appropriate combinations should be designed based on the functional mechanism. In this regard, metformin can be an attractive candidate for immunotherapeutic adjuvants. Metformin is a widely used oral medication for type 2 diabetes (T2D) and has been recognized as a safe and well-tolerated drug through several decades of clinical experience. Interestingly, metformin also exhibits antitumor effects as several case-control studies for T2D patients indicated that metformin reduces the incidence of various cancer types. However, the functions and the detailed mechanism of metformin related to cancer immunity are not fully understood. In this study, we investigated the antitumor effects of metformin in relation to cancer immunity in the tumor microenvironment. Our data showed that AMPK activated by metformin decreases the expression of PD-L1 in the cancer cells, blocking PD-L1’s ability to aid cancer cells in escaping immune surveillance. This is caused by the mechanism in which phosphorylation of PD-L1 at S195 induces an abnormal glycan structure that leads to endoplasmic reticulum-associated degradation. In addition, we have obtained human breast tumor tissues from a previous clinical trial investigating metformin as treatment for breast cancer patients. The data from human tumor tissues also provided strong support to our current conclusion, namely AMPK activated by metformin reduces the level of PD-L1. On the basis of these results, we validated the possibility of metformin as an adjuvant to boost the efficacy of previous immunotherapy without toxicity. Our findings suggest that metformin has strong potential to be used as an adjuvant for immunotherapy. Metformin is expected to have synergistic effect with various non-PDL1/PD-1 targeting immune therapies without additional toxicity.

Citation Format: Jong-Ho Cha, Wen-Hao Yang, Weiya Xia, Yongkun Wei, Li-Chuan Chan, Seung-Oe Lim, Chia-Wei Li, Jennifer Hsu, Hung-Ling Wang, Chu-Wei Kuo, Wei-Chao Chang, Sirwan Hadad, Colin Purdie, Aaron McCoy, Jennifer Litton, Elizabeth Mittendorf, Stacy Moulder, William Symmans, Alastair M Thompson, Helen Piwnica-Worms, Chung-Hsuan Chen, Kay-Hooi Khoo, Mien-Chie Hung. Metformin is a potential nontoxic adjuvant to enhance the efficacy of non-PDL1/PD-1 targeting immune therapies [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2018 Nov 27-30; Miami Beach, FL. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(4 Suppl):Abstract nr A16.

Measurement of Azimuthal Anisotropy of Muons from Charm and Bottom Hadrons in pp Collisions at sqrt[s]=13 TeV with the ATLAS Detector

The elliptic flow of muons from the decay of charm and bottom hadrons is measured in pp collisions at sqrt[s]=13  TeV using a data sample with an integrated luminosity of 150  pb^{-1} recorded by the ATLAS detector at the LHC. The muons from heavy-flavor decay are separated from light-hadron decay muons using momentum imbalance between the tracking and muon spectrometers. The heavy-flavor decay muons are further separated into those from charm decay and those from bottom decay using the distance-of-closest-approach to the collision vertex. The measurement is performed for muons in the transverse momentum range 4-7 GeV and pseudorapidity range |η|<2.4. A significant nonzero elliptic anisotropy coefficient v_{2} is observed for muons from charm decays, while the v_{2} value for muons from bottom decays is consistent with zero within uncertainties.

[Clinical and genetic analysis of childhood-onset myoclonus dystonia syndrome caused by SGCE variants]

Objective: To explore the clinical characteristics and genotyping results of childhood-onset myoclonus dystonia syndrome caused by SGCE variants. Methods: The clinical data of 9 children with SGCE-related myoclonus dystonia syndrome admitted at either the Department of Neurology, Beijing Children's Hospital, Capital Medical University or the Department of Pediatrics, Peking University First Hospital from May 2018 to October 2019 were collected and the patients were followed up. The definite diagnosis was made on the basis of whole exome sequencing and multiple ligation-dependent probe amplification. The clinical features and gene test results were analyzed retrospectively. Results: Data of 9 patients (4 boys and 5 girls) diagnosed as myoclonus dystonia syndrome caused by SGCE variants were collected. The onset age ranged from 1 year to 3 years and 2 months. The first symptom was myoclonus in 4 cases, while dystonia in the remaining 5 cases. In the course of the disease, 9 cases had myoclonus and 8 had dystonia. Myoclonic jerks were characterized by involuntary jerks in both upper limbs in 8 patients. Six patients had involuntary jerks of lower limbs, resulting in gait instability or even falling. The myoclonus was exacerbated during the fine motor activities, emotional stress or fatigue. Dystonia was characterized by abnormal gait, including 5 cases with right leg dystonia, and 3 cases with the left leg dystonia. Three probands had a positive family history. Intellectual development was normal in all cases. There was no obvious abnormality in video-electroencephalogram (EEG) during both ictal and interictal periods. Electromyography (EMG) and brain magnetic resonance imaging (MRI) of 9 patients were normal. Nine patients carried SGCE gene variants, including 3 frame shift variants, 2 nonsense variants, 2 missense variants, 1 fragment deletion variant and 1 splice site variant. Seven variants were inherited paternally, and 2 variants were de novo. Madopar was used in 8 patients, and nitrazepam in 4 patients, leading to the decrease in the myoclonus jerks and improvement of gait in 6 and 2 patients, respectively. Conclusions: SGCE gene variants can cause myoclonus dystonia syndrome. The onset of the disease may occur at infancy or preschool age, with either myoclonic jerks or dystonia as the initial symptom. Non-epileptic myoclonus is the prominent symptom, with upper limb mainly involved. Most of the patients have the accompanying symptoms of dystonia, and some of them may have spontaneous symptom relief. SGCE gene is imprinted maternally, and the inherited variants of SGCE are paternal in origin.

Search for Magnetic Monopoles and Stable High-Electric-Charge Objects in 13 Tev Proton-Proton Collisions with the ATLAS Detector

A search for magnetic monopoles and high-electric-charge objects is presented using 34.4  fb^{-1} of 13 TeV pp collision data collected by the ATLAS detector at the LHC during 2015 and 2016. The considered signature is based upon high ionization in the transition radiation tracker of the inner detector associated with a pencil-shape energy deposit in the electromagnetic calorimeter. The data were collected by a dedicated trigger based on the tracker high-threshold hit capability. The results are interpreted in models of Drell-Yan pair production of stable particles with two spin hypotheses (0 and 1/2) and masses ranging from 200 to 4000 GeV. The search improves by approximately a factor of 5 the constraints on the direct production of magnetic monopoles carrying one or two Dirac magnetic charges and stable objects with electric charge in the range 20≤|z|≤60 and extends the charge range to 60<|z|≤100.

Efficacy of a Latex Agglutination Test for Rapid Identification of Staphylococcus aureus: Collaborative Study

Fifteen laboratories completed a collaborative study comparing the efficacy of a latex agglutination kit (Aureus Test) with that of AOAC Official Method 987.09 (coagulase test for identification of Staphylococcus aureus). Each laboratory analyzed 240 strains of bacteria, including 160 isolates of S. aureus and 80 isolates of other bacteria. Upon receipt of cultures, collaborators subcultured each isolate on both tryptic soy agar (TSA) and Baird-Parker agar medium (BPA) to determine whether the growth medium has any effect on either method. For cultures grown on TSA, the latex test had sensitivity and specificity rates of 99.2 and 97.1 %, respectively, whereas the coagulase test had respective rates of 98.4 and 92.5%. For cultures able to grow on BPA, the latex test had sensitivity and specificity rates of 99.2 and 96.6%, respectively, while the coagulase test had respective rates of 98.3 and 91.3%. By using the McNemar pairwise comparison test of the 2 methods, the falsepositive and false-negative rates of the latex test were significantly lower (p &lt; 0.01) than those of the coagulase test for strains grown either on TSA or BPA. The latex agglutination test for identification of S. aureus isolated from foods has been adopted by AOAC INTERNATIONAL.

Musashi-1 promotes stress-induced tumor progression through recruitment of AGO2

Carcinomatous progression and recurrence are the main therapeutic challenges frequently faced by patients with refractory tumors. However, the underlined molecular mechanism remains obscure.

Methods: We found Musashi-1 (MSI1) transported into cytosol under stress condition by confocal microscopy and cell fractionation. Argonaute 2 (AGO2) was then identified as a cytosolic binding partner of MSI1 by Mass Spectrametry, immunoprecipitation, and recombinant protein pull-down assay. We used RNA-IP to determine the MSI1/AGO2 associated regions on downstream target mRNAs. Finally, we overexpressed C-terminus of MSI1 to disrupt endogenous MSI1/AGO2 interaction and confirm it effects on tmor progression.

Results: Malignant tumors exhibit elevated level of cytosolic Musashi-1 (MSI1), which translocates into cytosol in response to stress and promote tumor progression. Cytosolic MSI1 forms a complex with AGO2 and stabilize or destabilize its target mRNAs by respectively binding to their 3´ untranslated region or coding domain sequence. Both MSI1 translocation and MSI1/AGO2 binding are essential for promoting tumor progression. Blocking MSI1 shuttling by either chemical inhibition or point mutation attenuates the growth of GBM-xenografts in mice. Importantly, overexpression of the C-terminus of MSI1 disrupts endogenous MSI1/AGO2 interaction and effectively reduces stress-induced tumor progression.

Conclusion: Our findings highlight novel molecular functions of MSI1 during stress-induced carcinomatous recurrence, and suggest a new therapeutic strategy for refractory malignancies by targeting MSI1 translocation and its interaction with AGOs.