Co-transport behavior of Am(III) and natural colloids in the vadose zone sediments

Americium (III) (Am(III)) in the natural environment is considered immobile due to its low solubility, strong adsorption, and high affinity to solid surfaces. However, the presence of natural colloids may carry Am(III) transport for long distance. The individual and co-transport behaviors of Am(III) and natural colloids through the unsaturated packed columns were investigated under the influence of pH, electrolyte concentration, velocity, Am(III) concentration and natural colloids concentration. Under all experimental conditions, Am(III) individual transport construct sight breakthrough curves (BTCs, CAm/C0 < 3%), but the presence of natural colloids increased the BTCs plateau of Am(III) significantly (30% < CAm/C0 < 80%), indicating that the colloids were able to promote Am(III) transport in the unsaturated porous media. DLVO theoretical calculations reveal that the increased pH and decreased electrolyte concentration lead to a rase in electrostatic repulsion, and the natural colloids tend to be dispersed and stabilized, which facilitates elution. In addition to this, the increase of velocity and colloids concentration will lead to greater breakthrough of natural colloids. The non-equilibrium two-site model and the two-site kinetic retention model well-described the BTCs of Am(III) and natural colloids, respectively. This study provide new insights into the behavior of natural colloids carrying the Am(III) into aquifers through the vadose zone sediments.

Leaching behaviour of 226Ra from uranium tailings and adsorption behaviour in geotechnical medias

The leaching process of uranium tailings is a typical water-rock interaction. The release of 226Ra from uranium tailings depends on the nuclides outside the intrinsic properties of uranium tailings on the one hand, and is influenced by the water medium on the other. In this paper, a uranium tailings repository in southern China was used as a research object, and uranium tailings at different depths were collected by drilling samples and mixed to analyse the 226Ra occurrence states. Static dissolution leaching experiments of 226Ra under different pH conditions, solid-liquid ratio conditions, and ionic strength conditions were carried out, and the adsorption and desorption behaviours of 226Ra in five representative stratigraphic media were investigated. The results show that 226Ra has a strong adsorption capacity in representative strata, with adsorption distribution coefficient Kd values ranging from 1.07E+02 to 1.29E+03 (mL/g) and desorption distribution coefficients ranging from 4.97E+02 to 2.71E+03 (mL/g), but the adsorption is reversible. The 226Ra in uranium tailings exists mainly in the residual and water-soluble states, and the release of 226Ra from uranium tailings under different conditions is mainly from the water-soluble and exchangeable state fractions. Low pH conditions, low solid-liquid ratio conditions and high ionic strength conditions are favourable to the release of 226Ra from uranium tailings, so the release of 226Ra from uranium tailings can be reduced by means of adjusting the pH in the tailings and setting up a water barrier. The results of this research have important guiding significance for the management of existing uranium tailings ponds and the control of 226Ra migration in groundwater, which is conducive to guaranteeing the long-term safety, stability and sustainability of uranium mining sites.

Adsorption-desorption of 241Am(Ⅲ) on montmorillonite colloids and quartz sand: Effects of pH, ionic strength, colloid concentration and grain size

Clay colloids in the subsurface environment have a strong adsorption capacity for radionuclides, and the mobile colloids will carry the nuclides for migration, which would promote the movability of radionuclides in the groundwater environment and pose a threat to the ecosphere. The investigations of the adsorption/desorption behaviors of radionuclides in colloids and porous media are significant for the evaluation of the geological disposal of radioactive wastes. To illustrate the adsorption/desorption behaviors of 241Am(Ⅲ) in Na-montmorillonite colloid and/or quartz sand systems at different pH (5, 7 and 9), ionic strengths (0, 0.1 and 5 mM), colloid concentrations (300 and 900 mg/L), nuclide concentrations (500, 800, 1100 and 1400 Bq/mL) and grain sizes (40 and 60 mesh), a series of batch sorption-desorption experiments were conducted. Combining the analysis of the physical and chemical properties of Na-montmorillonite with the Freundlich model, the influencing mechanism of different controlling factors is discussed. The experimental results show that the adsorption/desorption behaviors of 241Am(Ⅲ) in Na-montmorillonite colloid and/or quartz sand strongly are influenced by the pH value and ionic strength of a solution, the colloid concentration as well as quartz sand grain size. The adsorption and desorption isotherms within all the experimental conditions could be well-fitted by the Freundlich model and the correlation coefficients (R2) are bigger than 0.9. With the increase in pH, the adsorption partition coefficient (Kd) at 241Am(Ⅲ)-Na-montmorillonite colloid two-phase system and 241Am(Ⅲ)-Na-montmorillonite colloid-quartz sand three-phase system presents a trend which increases firstly followed by decreasing, due to the changes in the morphology of Am with pH. The Kd of 241Am(Ⅲ) adsorption on montmorillonite colloid and quartz sand decreases with increasing in ionic strength, which is mainly attributed to the competitive adsorption, surface complexation and the reduction of surface zeta potential. Additionally, the Kd increases with increasing colloid concentrations because of the increase in adsorption sites. When the mean grain diameter changes from 0.45 to 0.3 mm, the adsorption variation trends of 241Am(Ⅲ) remain basically unchanged. The research results obtained in this work are meaningful and helpful in understanding the migration behaviors of radionuclides in the underground environment.

Research on leaching behavior of uranium from a uranium tailing and its adsorption behavior in geotechnical media

The release of uranium from uranium tailings into the aqueous environment is a complex process controlled by a series of interacting geochemical reactions. In this paper, uranium tailings from a uranium tailings pond in southern China were collected at different depths by means of borehole sampling and mixed to analyze the fugacity state of U. Static leaching experiments of U at different pH, oxidant concentration and solid-to-liquid ratios and dynamic leaching experiments of U at different pH were carried out, and the adsorption and desorption behaviour of U in five representative stratigraphic media were investigated. The results show that U is mainly present in the residue state in uranium tailings, that U release is strong in the lower pH range, that the leached U is mainly in the form of U(VI), mainly from the water-soluble, Fe/Mn oxides and exchangeable fraction of uranium tailings, and that the reduction in U leaching at higher pH is mainly due to the combined effect of precipitation formation and larger particle size of platelets in uranium tailings. Experiments with different oxidant concentrations and solid-liquid ratios showed that the oxygen-enriched state and low solid-liquid ratios were favorable for the leaching of U from uranium tailings. Adsorption and desorption experiments show that U is weakly adsorbed in representative strata, reversibly adsorbed, and that U is highly migratory in groundwater. The present research results have important guiding significance for the management of existing uranium tailings ponds and the control of U migration in groundwater, which is conducive to ensuring the long-term safety, stability and sustainability of uranium mining sites.

[Key microbial monitoring and clinical analysis of bloodstream infections and CRO colonization after hematopoietic stem cell transplantation in hematological patients]

Objective: To investigate the distribution and clinical characteristics of pathogenic bacteria following hematopoietic stem cell transplantation (HSCT), as well as to provide a preliminary research foundation for key microbial monitoring, and clinical diagnosis and treatment of infections after HSCT in hematological patients. Methods: We retrospectively analyzed the clinical data of 190 patients who tested positive for microbial testing [G-bacteria blood culture and/or carbapenem-resistant organism (CRO) screening of perianal swabs] at our center from January 2018 to December 2022. Patients were divided into blood culture positive, perianal swab positive, and double positive groups based on the testing results. The three patient groups underwent statistical analysis and comparison. Results: The top four pathogenic bacteria isolated from sixty-three patients with G-bacteria bloodstream infection (BSI) were Escherichia coli (28 strains, 43.75% ), Klebsiella pneumonia (26 strains, 40.63% ), Pseudomonas aeruginosa (3 strains, 4.69% ), and Enterobacter cloacae (3 strains, 4.69% ). The top three pathogenic bacteria isolated from 147 patients with CRO perianal colonization were carbapenem-resistant Klebsiella pneumoniae (58 strains, 32.58% ), carbapenem-resistant Escherichia coli (49 strains, 27.53% ), and carbapenem-resistant Enterobacter cloacae (20 strains, 11.24% ). The 3-year disease-free survival (DFS ) and overall survival (OS) of double positive group patients were significantly lower compared to those in the blood culture and perianal swab positive groups (DFS: 35.6% vs 53.7% vs 68.6%, P=0.001; OS: 44.4% vs 62.4% vs 76.9%, P<0.001), while non-relapse mortality (NRM) was significantly higher (50.0% vs 34.9% vs 10.6%, P<0.001). Failed engraftment of platelets and BSI are independent risk factors for NRM (P<0.001). Using polymyxin and/or ceftazidime-avibactam for more than 7 days is an independent protective factor for NRM (P=0.035) . Conclusion: This study suggests that the occurrence of BSI significantly increases the NRM after HSCT in patients with hematological diseases; CRO colonization into the bloodstream has a significant impact on the DFS and OS of HSCT patients.

Positional multi-length and mutual-attention network for epileptic seizure classification

The automatic classification of epilepsy electroencephalogram (EEG) signals plays a crucial role in diagnosing neurological diseases. Although promising results have been achieved by deep learning methods in this task, capturing the minute abnormal characteristics, contextual information, and long dependencies of EEG signals remains a challenge. To address this challenge, a positional multi-length and mutual-attention (PMM) network is proposed for the automatic classification of epilepsy EEG signals. The PMM network incorporates a positional feature encoding process that extracts minute abnormal characteristics from the EEG signal and utilizes a multi-length feature learning process with a hierarchy residual dilated LSTM (RDLSTM) to capture long contextual dependencies. Furthermore, a mutual-attention feature reinforcement process is employed to learn the global and relative feature dependencies and enhance the discriminative abilities of the network. To validate the effectiveness PMM network, we conduct extensive experiments on the public dataset and the experimental results demonstrate the superior performance of the PMM network compared to state-of-the-art methods.

Leaching behaviour and mechanism of U, 226Ra and 210Pb from uranium tailings at different pH conditions

A large number of radionuclides remain in uranium tailings, and U, 226Ra and 210Pb leach out with water chemistry, causing potential radioactive contamination to the surrounding environment. In this paper, uranium tailings from a uranium tailings pond in southern China were collected at different depths by means of borehole sampling, mixed and homogenised, and analysed for mineral and chemical composition, microscopic morphology, U, 226Ra and 210Pb fugacity, static leaching and dynamic leaching of U, 226Ra and 210Pb in uranium tailings at different pH conditions. The variation of U, 226Ra and 210Pb concentrations in the leachate under different pH conditions with time was obtained, and the leaching mechanism was analysed. The results showed that the uranium tailings were dominated by quartz, plagioclase and other minerals, of which SiO2 and Al2O3 accounted for 65.45% and 13.32% respectively, and U, 226Ra and 210Pb were mainly present in the residue form. The results of the static leaching experiments show that pH mainly influences the leaching of U, 226Ra and 210Pb by changing their chemical forms and the particle properties of the tailings, and that the lower the pH the more favourable the leaching. The results of dynamic leaching experiments during the experimental cycle showed that the leaching concentration and cumulative release of U, 226Ra and 210Pb in the leach solution were greater at lower pH conditions than at higher pH conditions, and the leaching of U, 226Ra and 210Pb at different pH conditions was mainly from the water-soluble and exchangeable states. The present research results are of great significance for the environmental risk management and control of radioactive contamination in existing uranium tailings ponds, and are conducive to ensuring the long-term safety, stability and sustainability of uranium mining sites.

Shaddock peel-derived N-doped carbon quantum dots coupled with ultrathin BiOBr square nanosheets with boosted visible light response for high-efficiency photodegradation of RhB

In the present work, we constructed a serials of novel shaddock peel-derived N-doped carbon quantum dots (NCQDs) coupled with BiOBr composites. The result showed that the as-synthesized BiOBr (BOB) was composed of ultrathin square nanosheets and flower-like structure, and NCQDs were uniformly dispersed on the surface of BiOBr. Furthermore, the BOB@NCQDs-5 with optimal NCQDs content displayed the top-flight photodegradation efficiency with ca. 99% of removal rate within 20 min under visible light and possessed excellent recyclability and photostability after 5 cycles. The reason was attributed to relatively large BET surface area, the narrow energy gap, inhibited recombination of charge carriers and excellent photoelectrochemical performances. Meanwhile, the improved photodegradation mechanism and possible reaction pathways were also elucidated in detail. On this basis, the study opens a novel perspective to obtain a highly efficient photocatalyst for practical environment remediation.

Acute myocardial infarction and myocarditis following COVID-19 vaccination

Emerging reports raise concerns on the potential association between the COVID-19 vaccines and cardiac manifestations. We sought to evaluate cardiac complications associated with COVID-19 vaccination in a pooled analysis from our institution's cohort study and systematic review. Consecutive patients admitted to a tertiary hospital in Singapore between 1 January 2021 and 31 March 2021, with the onset of cardiac manifestations within 14 days following COVID-19 vaccination, were studied. Furthermore, a systematic review was performed, with PubMed, Embase, Research Square, MedRxiv and LitCovid databases accessed from inception up to 29 June 2021. Relevant manuscripts reporting individual patient data on cardiac complications following COVID-19 vaccination were included. Thirty patients were included in the study cohort, with 29 diagnosed with acute myocardial infarction (AMI) and 1 with myocarditis. Five patients developed heart failure, two had cardiogenic shock, three intubated, and one had cardiovascular-related mortality. In the systematic review, 16 studies were included with 41 myocarditis and 6 AMI cases. In the pooled analysis of the study cohort and the systematic review, 35 patients had AMI and 42 had myocarditis. Majority were men, and myocarditis patients were younger than AMI patients. Myocarditis patients tended to present 72 h postvaccination, while AMI patients were older and typically presented 24 h postvaccination. Majority with AMI or myocarditis developed symptoms after the first and second vaccination dose, respectively. This pooled analysis of patients presenting with cardiac manifestations following COVID-19 vaccination highlights the differences between myocarditis and AMI presentations in temporal association with the vaccination.

Robotic versus laparoscopic left colectomy with complete mesocolic excision for left-sided colon cancer: a multicentre study with propensity score matching analysis

BACKGROUND

Robotic surgery for right-sided colon and rectal cancer has rapidly increased; however, there is limited evidence in the literature of advantages of robotic left colectomy (RLC) for left-sided colon cancer. The purpose of this study was to compare the outcomes of RLC versus laparoscopic left colectomy (LLC) with complete mesocolic excision (CME) for left-sided colon cancer.

METHODS

Patients who had RLC or LLC with CME for left-sided colon cancer at 5 hospitals in China between January 2014 and April 2022 were included. A one-to-one propensity score matched analysis was performed to decrease confounding. The primary outcome was postoperative complications occurring within 30 days of surgery. Secondary outcomes were disease-free survival, overall survival and the number of harvested lymph nodes.

RESULTS

A total of 292 patients (187 males; median age 61.0 [20.0-85.0] years) were eligible for this study, and propensity score matching yielded 102 patients in each group. The clinical-pathological characteristics were well-matched between groups. The two groups did not differ in estimated blood loss, conversion to open rate, time to first flatus, reoperation rate, or postoperative length of hospital stay (p > 0.05). RLC was associated with a longer operation time (192.9 ± 53.2 vs. 168.9 ± 52.8 minutes, p=0.001). The incidence of postoperative complications did not differ between the RLC and LLC groups (18.6% vs. 17.6%, p = 0.856). The total number of lymph nodes harvested in the RLC group was higher than that in the LLC group (15.7 ± 8.3 vs. 12.1 ± 5.9, p< 0.001). There were no significant differences in 3-year and 5-year overall survival or 3-year and 5-year disease-free survival.

CONCLUSIONS

Compared to laparoscopic surgery, RLC with CME for left-sided colon cancer was found to be associated with higher numbers of lymph nodes harvested and similar postoperative complications and long-term survival outcomes.

Advection-Dispersion Behavior for Simulation of H-3 and Pu-238 Transport in Undisturbed Argillaceous Shale of a Near-Surface Repository

In this study, a column experiment was employed to evaluate the nuclide migration behavior in the surrounding rock medium of a near-surface disposal site in China and to investigate the advection-dispersion behavior of tritium (H-3) and plutonium-238 (Pu-238) in highly weathered argillaceous shale. A reasonable numerical model was selected to fit the experimental breakthrough curves (BTCs) and to obtain the relevant migration parameters. The results show the following: (1) the internal structure of the highly weathered argillaceous shale exhibited heterogeneity, and the nuclide migration BTC showed characteristics of a "curve peak moving forward" and a "tail curve trailing"; (2) compared with other models, the stream tube mode could better fit the BTCs and obtain the average dispersion coefficient <D>, average distribution coefficient <K_d>, and other parameters; (3) compared to the results of the batch experiment, the distribution coefficient K_d obtained from the column experiment was smaller than that obtained from the batch experiment, which is speculated to be due to the influence of contact time and the contact area between the nuclide and the medium.

Solution to the particle concentration effect on determining Kd value of radionuclides

The particle concentration effect on Kd values of radionuclides has been observed but the underlying mechanism remains controversial. The hope is to use the relationship between particle concentration, adsorption-desorption isotherms and reversibility, in combination with surface component activity of model (SCA model), to solve this issue. 137Cs, 60Co, 90Sr were used as tracers, batch experiments were conducted in freshwater-sediment and seawater-sediment. The experiment of each radionuclide was designed with five different particle concentrations Cp, and for each Cp there were seven different initial concentrations C0. After adsorption experiments, four consecutive desorption experiments were carried out. At the fourth desorption experiment, radionuclide concentrations in the supernatant and sediment were measured. The results showed that adsorption and single desorption data of 137Cs, 60Co, 90Sr might be described by linear isotherms. 137Cs was reversible in the seawater-sediment, so hysteresis angles of the five-particle concentration were approximately 0°, all adsorption and desorption data could be classified into one line. In the remaining systems, besides the adsorption and single desorption isotherms moved upward with the decrease of particle concentration, hysteresis angles and irreversibility also increased, thus, the particle concentration effect was obvious. The reversible and resistant component concentrations calculated by adsorption, single desorption and consecutive desorption isotherm were linear functions of equilibrium concentration Ce1, respectively. Data from adsorption and desorption experiments with particle concentration effect could be classified into the same line using the Freundlich-SCA model. The results of this study indicate that the particle concentration effect is related to reversibility. When adsorption isotherm and single desorption isotherm are both linear, consecutive desorption isotherm, reversible and resistant component concentrations approach linearity too. After the Freundlich-SCA model eliminated the particle concentration effect on adsorption and desorption data, the data can be used to predict the adsorption, single desorption isotherm and Kd value at any particle concentration.

Higher long-term mortality in patients with concomitant acute coronary syndrome and aortic stenosis

Background

Aortic stenosis (AS) and acute coronary syndrome (ACS) share similar cardiovascular risk factors, and their concomitant presentation is increasing in incidence with the aging population. Yet literature regarding the prognosis of patients with concomitant ACS and AS remains scarce.

Methods

This retrospective cohort study examined consecutive patients presenting with ACS (ST-segment elevation myocardial infarction [STEMI] and non-STEMI [NSTEMI]) and concomitant AS between 1 January 2011 and 31 March 2021 in a tertiary hospital. The cohort was divided into mild, moderate and severe AS based on index echocardiogram. The primary outcome was all-cause mortality. Kaplan-Meier curves were constructed to compare all-cause mortality among the three groups of patients, based on ACS type and left ventricular ejection fraction (LVEF). Multivariable Cox regression was performed to identify independent predictors of all-cause mortality.

Results

Of a total of 563 patients, 264 had mild (46.9%), 193 moderate (34.3%) and 106 severe AS (18.8%). The mean follow-up duration was 2.5 (± 2.4) years. Majority of patients (72.5%) presented with NSTEMI. Patients with moderate and severe AS had higher rates of all-cause mortality compared to those with mild AS (49.7% vs. 51.4% vs. 35.6% respectively, p=0.002). Concomitant moderate (HR 1.439, 95% CI 1.012–2.048, p=0.043) and severe AS (HR 1.844, 95% CI 1.159–2.933, p=0.010) were independent predictors of all-cause mortality after adjusting for age, gender, LVEF, ACS type, chronic kidney disease, diabetes, hypertension, coronary artery bypass grafting and aortic valve replacement as a time-dependent variable. The Kaplan-Meier curves demonstrated excess mortality in moderate and severe AS, compared to the mild AS group (p&lt;0.001), with similar survival trends observed in the STEMI and the NSTEMI groups, as well as those with preserved LVEF.

Conclusion

Regardless of the ACS presentation type, long-term excess mortality in those with concomitant moderate or severe AS was observed. The adverse prognosis typically observed in patients with concomitant severe AS, in the setting of ACS, extends to patients with moderate AS.

Funding Acknowledgement

Type of funding sources: None.

Prognostically distinct phenotypes of metabolic health beyond obesity in aortic stenosis

Background

Whilst current evidence are in favour of metabolic health and non-obesity in the reduction of incident cardiovascular disease, little is known regarding the prognosis across the metabolic phenotypes once cardiovascular disease occurs. This study examined the prognosis of patients with significant aortic stenosis (AS) based on the presence of metabolic health and obesity.

Methods

This retrospective cohort on consecutive patients presenting with moderate-to-severe AS to a tertiary hospital between 2010 and 2015. Patients were allocated into 4 groups based on obesity and metabolic health: metabolically healthy obese (MHO), metabolically healthy non-obese (MHNO), metabolically unhealthy obese (MUO) and metabolically unhealthy non-obese (MUNO). Metabolic health was defined in accordance to Program Adult Treatment Panel III criteria. The primary outcome was all-cause mortality. Cox regression examined independent associations between mortality and metabolic phenotypes, adjusting for aortic valve area, ejection fraction, age, sex, chronic kidney disease and AVR as a time-dependent covariate.

Results

Of 727 patients, the majority (51.6%) were MUNO, followed by MUO (32.7%), MHNO (11.4%), and MHO (4.3%). MHNO had the highest mortality (43.0%), followed by the MUNO (37.5%), MUO (30.0%) and MHO (6.9%) groups (p=0.001). Compared to MHNO, MHO (HR 0.159, 95% CI 0.038–0.668, p=0.012) and MUO (HR 0.614, 95% CI 0.403–0.937, p=0.024) were independently associated with lower all-cause mortality rates, after adjusting for confounders. In obese patients, metabolic health had favourable survival compared to metabolically unhealthy (p=0.015), but this protective impact of metabolic health was not observed in overweight or normal weight individuals. Obesity had favourable survival compared to overweight and normal weight, in both metabolically health (p=0.002) and unhealthy (p=0.007) patients,

Conclusion

MHO patients with AS have the most favourable prognosis whilst the seemingly healthy MHNO group had the worst survival. There should be a paradigm shift towards prioritising metabolic health rather than weight reduction in patients with significant AS.

Funding Acknowledgement

Type of funding sources: None.

Study on Tritium and Iodine Species Transport through Porous Granite: A Non-Sorption Effect by Anion Exclusion

The safety of deep geological repositories is important in the disposal of high-level radioactive waste (HLW). In this study, advection−dispersion experiments were designed to build a transport model through a calibration/validation process, and the transport behavior of tritiated water (HTO) and various iodine species (iodide: I− and iodate: IO3−) was studied on a dynamic compacted granite column. Breakthrough curves (BTCs) were plotted under various flow rates (1−5 mL/min). BTCs showed that the non-sorption effect by anion exclusion was observed only in I− transport because the retardation factor (R) of I− was lower than that of HTO (R = 1). Moreover, equilibrium and nonequilibrium transport models were used and compared to identify the mobile/immobile zones in the compacted granite column. The anion exclusion effect was influenced by the immobile zones in the column. The non-sorption effect by anion exclusion (R < 1) was only observed for I− at 5.0 ± 0.2 mL/min flow rate, and a relatively higher Coulomb’s repulsive force may be caused by the smaller hydration radius of I−(3.31 Å) than that of IO3−(3.74 Å).

Clinical Observation of General Anesthesia Combined with Spinal Anesthesia in Elderly Patients with Chronic Obstructive Pulmonary Disease

Objective

This work is aimed at evaluating the efficacy and safety of general anesthesia (GA) combined with spinal anesthesia (SA) (GA+SA) in elderly patients with chronic obstructive pulmonary disease (COPD). Methods and Material. 50 elderly COPD patients were rolled randomly into a control group (simple GA) and observation group (GA+SA). The differences in operation time, postoperative recovery time (PRT), language expression time (LET), anesthetic dosage (AD), catheter extubation time (CET), respiratory circulation indicators (mean arterial pressure (MAP), heart rate (HR), SaO2, and PaO2), postoperative VRS score, pulmonary function (forced vital capacity (FVC)), forced expiratory volume in 1 s (FEV1)/FVC and forced expiratory flow (FEF 25%~75%), serum inflammatory factors (IL-6, IL-8, and TNF-α), Short Portable Mental Status Questionnaire (SPMSQ) score, and the incidence of respiratory system events were analyzed.

Results

The results showed that the PRT, LET, AD, and CET of the observation group were all shorter (P < 0.05). The postoperative MAP, HR, SaO2, and PaO2 levels of patients who received GA+SA were much higher than those who received simple GA (P < 0.05). The postoperative VRS score of the observation group was better than that of the controls (P < 0.05). The postoperative pulmonary function of patients in the observation group was better compared with that in the control group (P < 0.05). The postoperative serum inflammatory factors in the observation group were lower in contrast to the patients who received simple GA (P < 0.05). The postoperative cognitive function SPMSQ score of patients who received GA+SA was lower compared with the score of patients who received simple GA (P < 0.05). However, the probability of respiratory system events in the observation group was lower (P < 0.05).

Conclusion

In conclusion, GA+SA could significantly shorten the PRT and improve the recovery quality of elderly COPD patients. It can also reduce the postoperative inflammatory response and strengthen the pulmonary function and cognitive function. It also enhances the analgesic which is beneficial to patients' postoperative recovery. Therefore, GA+SA was a highly effective and safe anesthesia method for elderly patients with COPD, and it was worthy of clinical application.

A Retrospective Cohort Study of the Efficacy, Safety, and Clinical Value of 6-TG versus 6-MP Maintenance Therapy in Children with Acute Lymphoblastic Leukemia

Objective

To explore the efficacy, safety, and clinical value of 6-TG versus 6-MP when treating childhood acute lymphoblastic leukemia (ALL).

Methods

The study period was from January 2017 to June 2021. The subjects of this study were 100 children with ALL who were treated in our hospital. According to different intervention methods, the children who received 6-MP maintenance therapy were selected as the control group, with a total of 57 cases. Children with TG maintenance therapy were included in the research group, a total of 43 cases. The ICNS recurrence rate, non-ICNS recurrence rate, first remission mortality rate, secondary malignant tumor, and other indicators were compared.

Results

First of all, we compared the effective rate: complete remission (CR), partial remission, and nonremission in the study group, and the effective rate was 87.5%. In the control group, there were CR, partial remission, and no remission, and the effective rate was 65.5%. The effective rate of the study group was higher, and the difference between groups was statistically significant (P < 0.05). There were 55 cases of failure in the study group, with an incidence of 21.91%. There were 42 cases of total failure events in the control group, the incidence rate was 18.02%, and there exhibited no remarkable difference (P > 0.05). In the study group, 6 cases died in the first remission, with a fatality rate of 2.39%, while there exhibited no death in the control group. The mortality in the first remission period in the study group was lower (P < 0.05). The overall recurrence rate of the study group was 5.57%, while that of the control group was 11.15%. The overall recurrence rate of the study group was lower, and the difference between groups was statistically significant (P < 0.05). The recurrence rate of ICNS was 2.14% in the study group and 2.98% in the control group, and there exhibited no remarkable difference (P > 0.05). The non-ICNS recurrence rate was 3.43% in the study group and 7.17% in the control group. There exhibited no remarkable difference (P > 0.05). The incidence of secondary malignant tumor events was 0.85% in the study group and 1.59% in the control group. There exhibited no remarkable difference (P > 0.05). The incidence of hepatic vein occlusive disease was 7.29% in the study group and 2.39% in the control group. The incidence of hepatic vein occlusive disease in the study group was higher, and the difference between groups was statistically significant (P < 0.05). Finally, we compared the incidence of adverse reactions. In the study group, there were 12 cases of oral mucosal damage, 7 cases of liver function damage, 6 cases of infection, 10 cases of myelosuppression, 9 cases of gastrointestinal reaction, and 4 cases of skin damage; the incidence rate was 23.17%. In the control group, there were 12 cases of oral mucosal damage, 7 cases of liver function damage, 6 cases of infection, 10 cases of myelosuppression, 9 cases of gastrointestinal reaction, and 4 cases of skin damage, with an incidence of 19.12%. There exhibited no remarkable difference in the incidence of adverse reactions (P > 0.05).

Conclusion

6-TG maintenance therapy in children with ALL can enhance the overall effective rate, can reduce the first remission mortality and the total recurrence rate, and will not increase the overall incidence of adverse reactions, but the incidence of reversible or irreversible hepatic veno-occlusive disease is remarkably increased, which has a certain clinical value.

Background

Treatment-related hepatotoxicity and myelosuppression remain formidable challenges for clinicians. Pharmacokinetic studies found that 6-TG has a more direct intracellular activation pathway, shorter cytotoxic time, and stronger potency than 6-MP. Therefore, this study investigated the efficacy, safety, and clinical value of 6-TG and 6-MP in the treatment of children with ALL.

A scintillator attenuation spectrometer for intense gamma-rays

A new type of compact high-resolution high-sensitivity gamma-ray spectrometer for short-pulse intense gamma-rays (250 keV to 50 MeV) has been developed by combining the principles of scintillators and attenuation spectrometers. The first prototype of this scintillator attenuation spectrometer (SAS) was tested successfully in Trident laser experiments at LANL. Later versions have been used extensively in the Texas Petawatt laser experiments in Austin, TX, and more recently in OMEGA-EP laser experiments at LLE, Rochester, NY. The SAS is particularly useful for high-repetition-rate laser applications. Here, we give a concise description of the design principles, capabilities, and sample preliminary results of the SAS.

OP0015 PROINFLAMMATORY MONOCYTES AND MACROPHAGES IN SYNOVIAL FLUID AND BURSAL TISSUE OF PATIENTS WITH POLYMYALGIA RHEUMATICA: POTENT PRODUCERS OF IL-6 AND GM-CSF

Background

Polymyalgia rheumatica (PMR) is a common, rheumatic inflammatory disease. Inflammation of bursae and tendon sheaths is a characteristic finding in patients with PMR. Glucocorticoid treatment remains the mainstay treatment for PMR. A study published in 1996 reported that macrophages dominate the inflammatory infiltrates in the glenohumeral synovium of PMR patients1, suggesting the importance of these cells in the immunopathology of PMR. However, the functional and phenotypical heterogeneity of the tissue-infiltrating macrophages in PMR remains obscure. Although treatment with anti-IL-6 receptor (tocilizumab) has shown promising results2, it is unclear whether macrophages contribute to IL-6 production in PMR. Additionally, anti-GM-CSF receptor therapy (mavrilimumab), recently shown to be efficacious in the closely related disease giant cell arteritis3, may also be useful for the treatment of PMR. Knowledge on the functional heterogeneity of monocytes/macrophages in PMR may aid in identifying novel therapeutic targets for this condition.

Objectives

To determine the phenotype of monocyte/macrophages in peripheral blood, bursal/tenosynovial fluid and bursal tissue of patients with PMR.

Methods

Paired peripheral blood (PB), bursal/tenosynovial fluid (SF) and bursal tissue biopsy samples from 11 PMR patients were included in our study. Bursal and tenosynovial samples were obtained from the shoulder. Distribution of the monocyte subsets (classical, intermediate and non-classical monocytes) was determined based on the level of CD14 and CD16 expression by flow cytometry. To study monocyte activation status, markers of ‘M1’ like (CD80 and CD64) and ‘M2’ like (CD206 and FRβ) macrophage polarization were included in the flow cytometry analysis. Immunohistochemistry of bursal tissue biopsies was focused on macrophage markers (CD68, CD86, CD64, CD206 and FRβ) andproinflammatory cytokines (IL-6 and GM-CSF), which were scored semi-quantitatively. Double immunofluorescence stainings were performed to determine the expression of IL-6 and GM-CSF by tissue-infiltrating macrophages in bursal tissue.

Results

Monocytes were detected in the SF of PMR patients. The proportion of classical monocytes was significantly lowered (p=0.001) in SF versus PB, while the proportion of intermediate monocytes was significantly elevated (p=0.001). The expression of CD206 was significantly elevated (p=0.001) but not FRβ in SF monocytes, suggesting GM-CSF skewed phenotype. In bursal tissue, macrophages displayed mixed ‘M1’/’M2’ traits with high expression of all macrophage polarization markers. Proinflammatory cytokines IL-6 and GM-CSF were highly expressed throughout the bursal tissue biopsies. Double immunofluorescence staining confirmed the expression of IL-6 and GM-CSF by the infiltrating macrophages.

Conclusion

SF monocytes and bursal tissue macrophages show a pro-inflammatory phenotype in PMR. Moreover, tissue-infiltrating macrophages show a prominent IL-6 and GM-CSF response in PMR. Our data add to the rationale of targeting IL-6 and GM-CSF as treatment options in PMR.

References

[1]Meliconi R, Pulsatelli L, Uguccioni M, et al. Leukocyte infiltration in synovial tissue from the shoulder of patients with polymyalgia rheumatica. Quantitative analysis and influence of corticosteroid treatment. Arthritis Rheum. 1996;39(7):1199-1207.

[2]Devauchelle-Pensec V, Berthelot JM, Cornec D, et al. Efficacy of first-line tocilizumab therapy in early polymyalgia rheumatica: a prospective longitudinal study. Ann Rheum Dis. 2016;75(8):1506-1510.

[3]Cid MC, Unizoni S, Pupim L, et al. Mavrilimumab (anti GM-CSF Receptor α Monoclonal Antibody) Reduces Time to Flare and Increases Sustained Remission in a Phase 2 Trial of Patients with Giant Cell Arteritis [Abstract]. Arthritis Rheumatol. 2020; 72 (suppl 10).

Acknowledgements

This work was supported by a research grant from FOREUM Foundation for Research in Rheumatology. The PMR Research On disease Mechanisms In Synovium (PROMIS) study was also funded by the Rheumatology Grant (Dutch Society for Rheumatology) and Mandema Stipend (University Medical Center Groningen).

Disclosure of Interests

William Febry Jiemy: None declared, Rosanne Reitsema: None declared, Anqi Zhang: None declared, Maria Sandovici: None declared, Annemieke Boots: None declared, Peter Heeringa: None declared, Elisabeth Brouwer Speakers bureau: E. Brouwer reports speaker and consulting fees from Roche in 2017-2018, outside the submitted work, Consultant of: E. Brouwer reports speaker and consulting fees from Roche in 2017-2018, outside the submitted work, Kornelis van der Geest Consultant of: K. van der Geest reports personal fees from Roche, outside the submitted work.

Deep Scale-Variant Network for Femur Trochanteric Fracture Classification with HP Loss

Achieving automatic classification of femur trochanteric fracture from the edge computing device is of great importance and value for remote diagnosis and treatment. Nevertheless, designing a highly accurate classification model on 31A1/31A2/31A3 fractures from the X-ray is still limited due to the failure of capturing the scale-variant and contextual information. As a result, this paper proposes a deep scale-variant (DSV) network with a hybrid and progressive (HP) loss function to aggregate more influential representations of the fracture regions. More specifically, the DSV network is based on the ResNet and integrated with the designed scale-variant (SV) layer and HP loss, where the SV layer aims to enhance the representation ability to extract the scale-variant features, and HP loss is intended to force the network to condense more contextual clues. Furthermore, to evaluate the effect of the proposed DSV network, we carry out a series of experiments on the real X-ray images for comparison and evaluation, and the experimental results demonstrate that the proposed DSV network could outperform other classification methods on this classification task.

Thermal Analysis of PE Extended Chain Crystal of PE Extended Chain Crystal from Gel Spinning

It has been recognized that ultra-high strength and high modulus ultra-highly drawn Polyethylene (PE) fiber is produced from the formation of extended chain crystal. Nevertheless, whether extended chain crystal exists in gel spinning ultra-highly drawn PE fiber is still an unsettled question. In this work, decalin was adopted as a solvent for PE gel spinning. By means of thermal analysis, X-ray diffraction methods etc, the existence of extended chain crystal was explored. Reasons for confusion in previous studies of this problem were discussed.

In PE fiber from 3 wt-°/o dope, extended chain crystal starts to form during draw ratios over 20. When draw ratio equals 42, the content of extended chain crystal roughly equals that of folded chain crystal. The melting point of extended chain crystal is 6°C higher than that of folded chain crystal. They are 145.5° C and 150° C to 152.5° C respectively. The latter would slightly rise with arise of draw ratio.

Multi-crystallization behavior of annealed PE fiber was determined and discussed. It was also confirmed that there is a linear logarithm relationship between thermal shrinkage (internal stresses) and fiber moduli.

Evidence for X(3872) in Pb-Pb Collisions and Studies of its Prompt Production at sqrt[s_{NN}]=5.02 TeV

The first evidence for X(3872) production in relativistic heavy ion collisions is reported. The X(3872) production is studied in lead-lead (Pb-Pb) collisions at a center-of-mass energy of sqrt[s_{NN}]=5.02  TeV per nucleon pair, using the decay chain X(3872)→J/ψπ^{+}π^{-}→μ^{+}μ^{-}π^{+}π^{-}. The data were recorded with the CMS detector in 2018 and correspond to an integrated luminosity of 1.7  nb^{-1}. The measurement is performed in the rapidity and transverse momentum ranges |y|<1.6 and 15<p_{T}<50  GeV/c. The significance of the inclusive X(3872) signal is 4.2 standard deviations. The prompt X(3872) to ψ2S yield ratio is found to be ρ^{Pb-Pb}=1.08±0.49(stat)±0.52(syst), to be compared with typical values of 0.1 for pp collisions. This result provides a unique experimental input to theoretical models of the X(3872) production mechanism, and of the nature of this exotic state.

An application research for near-surface repository of strontium-90 sorption kinetic model on mudrocks

In this study,90Sr was used as the test radionuclide to characterize the sorption kinetics and effects of initial 90Sr activity and remaining 90Sr in solid concentration were simulated for a near-surface repository. The study focused on the sorption characteristics of radionuclides in unsaturated groundwater environment (or vadose zone) is the important information for investigating the near-surface disposal of intermediate and low-level radioactive waste (ILLW). Moreover, the 90Sr sorption experiments reached equilibrium within 56 h, which fit to the first order sorption kinetic model, and the remaining 90Sr in mudrock samples showed obvious sorption equilibrium hysteresis, which fit to the second order sorption kinetic model. Before reaching the maximum sorption capacity, the sorption rate constant increases with 90Sr increasing; the distribution coefficient (Kd) of 56 h decreases with the remaining 90Sr decreasing. In addition, it showed that the slow sorption process dominated before the sorption reaches equilibrium. In fact, a reliable safety assessment methodology for on-going near-surface repository required a lot of the radionuclides parameters with local environment including the radionuclides sorption/desorption rate constant and maximum sorption capacity.

Robust Evaluation of Ultraviolet-C Sensitivity for SARS-CoV-2 and Surrogate Coronaviruses

UV light, more specifically UV-C light at a wavelength of 254 nm, is often used to disinfect surfaces, air, and liquids. In early 2020, at the cusp of the COVID-19 pandemic, UV light was identified as an efficient means of eliminating coronaviruses; however, the variability in published sensitivity data is evidence of the need for experimental rigor to accurately quantify the effectiveness of this technique. In the current study, reliable and reproducible UV techniques have been adopted, including accurate measurement of light intensity, consideration of fluid UV absorbance, and confirmation of uniform dose delivery, including dose verification using an established biological target (T1UV bacteriophage) and a resistant recombinant virus (baculovirus). The experimental results establish the UV sensitivity of SARS-CoV-2, HCoV-229E, HCoV-OC43, and mouse hepatitis virus (MHV) and highlight the potential for surrogate viruses for disinfection studies. All four coronaviruses were found to be easily inactivated by 254 nm irradiation, with UV sensitivities of 1.7, 1.8, 1.7, and 1.2 mJ/cm2/log10 reduction for SARS-CoV-2, HCoV-229E, HCoV-OC43, and MHV, respectively. Similar UV sensitivities for these species demonstrate the capacity for HCoV-OC43, HCoV-229E, and MHV to be considered surrogates for SARS-CoV-2 in UV-inactivation studies, greatly reducing hazards and simplifying procedures for future experimental studies. IMPORTANCE Disinfection of SARS-CoV-2 is of particular importance due to the global COVID-19 pandemic. UV-C irradiation is a compelling disinfection technique because it can be applied to surfaces, air, and water and is commonly used in drinking water and wastewater treatment facilities. UV inactivation depends on the dose received by an organism, regardless of the intensity of the light source or the optical properties of the medium in which it is suspended. The 254 nm irradiation sensitivity was accurately determined using benchmark methodology and a collimated beam apparatus for four coronaviruses (SARS-CoV-2, HCoV-229E, HCoV-OC43, and MHV), a surrogate indicator organism (T1UV), and a resistant recombinant virus (baculovirus vector). Considering the light distribution across the sample surface, the attenuation of light intensity with fluid depth, the optical absorbance of the fluid, and the sample uniformity due to mixing enable accurate measurement of the fundamental inactivation kinetics and UV sensitivity.

Isobutanol tolerance and production of Saccharomyces cerevisiae can be improved by engineering its TATA-binding protein Spt15

Low isobutanol tolerance of Saccharomyces cerevisiae limits its application in isobutanol fermentation. Here, we used global transcription machinery engineering to screen mutants with higher isobutanol tolerance and elevated isobutanol titres. TATA-binding protein Spt15 was used as the target of global transcription machinery engineering for improvement of such complex phenotypes. A random mutagenesis library of S. cerevisiae TATA-binding protein Spt15 was constructed and subjected to screening under isobutanol stress. A mutant strain (denoted as spt15-3) with improved isobutanol tolerance was identified. There were three mutations of Spt15 in strain spt15-3, including deletion of A at position -132 nt upstream of initiation codon, insertion of G at position -65 nt upstream of initiation codon and a synonymous mutation at position 315 nt (T → C) downstream of initiation codon. We then metabolically engineered isobutanol synthesis in strains harbouring plasmids YCplac22 containing these Spt15 mutations. Delta integration was used to overexpress ILV3 gene, and 2μ plasmids carrying PGK1p-ILV2 and PGK1p-ARO10 were used to overexpress ILV2 and ARO10 genes. After 24-h micro-aerobic fermentation, Engi-3 produced 0·556 g l^-1 isobutanol, which was 404% and 25·3% greater than isobutanol produced by control Engi-1 and engineered Engi-2, respectively. After 28 h, Engi-4 produced 0·459 g l^-1 isobutanol, which was 315% and 3·2% greater than isobutanol produced Engi-1 and Engi-2, respectively. RNA-Seq-based transcriptome analysis shows that mutations of Spt15 in strain spt15-3 increased the expression of SPT15. Meanwhile, compared with strain Engi-3, the spt15-3 mutation downregulated the expression of genes involved in the TCA cycle and glyoxylic acid cycle, but increased the expression of genes related to cell stability. This work demonstrates that isobutanol tolerance and production of S. cerevisiae can be improved by engineering its TATA-binding protein Spt15. This study clarified the molecular mechanisms regulating isobutanol production and tolerance in S. cerevisiae.

A Review of Mechano-Biochemical Models for Testing Composite Restorations

Due to the severe mechano-biochemical conditions in the oral cavity, many dental restorations will degrade and eventually fail. For teeth restored with resin composite, the major modes of failure are secondary caries and fracture of the tooth or restoration. While clinical studies can answer some of the more practical questions, such as the rate of failure, fundamental understanding on the failure mechanism can be obtained from laboratory studies using simplified models more effectively. Reviewed in this article are the 4 main types of models used to study the degradation of resin-composite restorations, namely, animal, human in vivo or in situ, in vitro biofilm, and in vitro chemical models. The characteristics, advantages, and disadvantages of these models are discussed and compared. The tooth-restoration interface is widely considered the weakest link in a resin composite restoration. To account for the different types of degradation that can occur (i.e., demineralization, resin hydrolysis, and collagen degradation), enzymes such as esterase and collagenase found in the oral environment are used, in addition to acids, to form biochemical models to test resin-composite restorations in conjunction with mechanical loading. Furthermore, laboratory tests are usually performed in an accelerated manner to save time. It is argued that, for an accelerated multicomponent model to be representative and predictive in terms of both the mode and the speed of degradation, the individual components must be synchronized in their rates of action and be calibrated with clinical data. The process of calibrating the in vitro models against clinical data is briefly described. To achieve representative and predictive in vitro models, more comparative studies of in vivo and in vitro models are required to calibrate the laboratory studies.

P–138 When is low quality really low? Should we transfer low-grade blastocysts?

Study question

What is the live birth rate after single, low-grade blastocyst (LGB) transfer?

Summary answer

The live birth rate for LGBs is 28%, ranging between 15–31% for the different inner cell mass (ICM) and trophectoderm (TE) subgroups of LGBs.

What is known already

Live birth rates following LGB transfer are varied and have been reported to be in the range of 5–39%. However, these estimates are inaccurate as studies investigating live birth rates following LGB transfer are inherently limited by sample size (n = 10–440 for LGB transfers) due to LGBs being ranked last for transfer. Further, these studies are heterogenous with varied LGB definitions and design. Collating LGB live birth data from multiple clinics is warranted to obtain sufficient numbers of LGB transfers to establish reliable live birth rates, and to allow for delineation of different LGB subgroups, including blastocyst age and female age.

Study design, size, duration

We performed a multicentre, multinational retrospective cohort study in 9 IVF centres in China and New Zealand from 2012 to 2019. We studied the outcome of 6966 single blastocyst transfer cycles on days 5–7 (fresh and frozen) according to blastocyst grade, including 875 transfers from LGBs (&lt;3bb, this being the threshold typically applied to LGB studies). Blastocysts with expansion stage 1 or 2 (early blastocysts) were excluded.

Participants/materials, setting, methods

The main outcome measured was live birth rate. Blastocysts were grouped according to quality grade: good-grade blastocysts (GGBs; n = 3849, aa, ab and ba), moderate-grade blastocysts (MGBs; n = 2242, bb) and LGBs (n = 875, ac, ca, bc, cb and cc) and live birth rates compared using the Pearson Chi-squared test. A logistic regression analysis explored the relationship between blastocyst grade and live birth after adjustment for the confounders: clinic, female age, expansion stage, and blastocyst age.

Main results and the role of chance

The live birth rates for GGBs, MGBs and LGBs were 45%, 36% and 28% respectively (p &lt; 0.0001). Within the LGB group, the highest live birth rates were for grade c TE (30%) and the lowest were for grade c ICM (19%). The lowest combined grade (cc) maintained a 15% live birth rate (n = 7/48). After accounting for confounding factors, including female age and blastocyst characteristics, the odds of live birth were 2.33 (95% CI = 1.88–2.89) for GGBs compared to LGBs and 1.56 (95% CI = 1.28–1.92) for MGBs compared to LGBs following fresh and frozen blastocyst transfers (p &lt; 0.0001, odds ratios confirmed in exclusively frozen blastocyst transfer cycles). When stratified by individual ICM and TE grade, the odds of live birth according to ICM grade were 1.31 (a versus b; 95% CI = 1.15–1.48), 2.82 (a versus c; 95% CI = 1.91–4.18) and 2.16 (b versus c; 95% CI = 1.48–3.16; all p &lt; 0.0001). The odds of live birth according to TE grade were 1.33 (a versus b; 95% CI = 1.17–1.50, p &lt; 0.0001), 1.85 (a versus c; 95% CI = 1.45–2.34, p &lt; 0.0001) and 1.39 (b versus c; 95% CI = 1.12–1.73, p = 0.0024).

Limitations, reasons for caution

Despite the large multicentre design of the study, analyses of transfers occurring within the smallest subsets of the LGB group were limited by sample size. The study was not randomised and had a retrospective character.

Wider implications of the findings: LGBs maintain satisfactory live birth rates (averaging 28%) in the general IVF population. Even those in the lowest grading tier maintain modest live birth rates (15%; cc). It is recommended that LGBs not be universally discarded, and instead considered for subsequent frozen embryo transfer to maximize cumulative live birth rates.

Trial registration number

Not applicable

Second-trimester abdominal circumference discordance and adverse perinatal outcomes in monochorionic twins

OBJECTIVE

The perinatal outcomes in second-trimester abdominal circumference (AC) discordant twins are yet to be established. The aim of this study was to ascertain perinatal risks associated with second-trimester AC discordance in monochorionic (MC) twins.

METHOD

We conducted a retrospective study of all MC twin pregnancies over a 7-year period. Intertwin AC discordance at 14-26 gestational weeks was analyzed in relation to Doppler abnormalities, obstetric complications, and perinatal adverse outcomes.

RESULTS

A total of 246 MC twin pregnancies were included in the analysis. The smaller twins of second-trimester AC discordant pairs were at increased prevalence of abnormal umbilical artery flow (50% versus 24%, p < .001) and low positive A wave of ductus venous flow (24% versus 9%, p = .002). The second-trimester AC discordant twins were at increased risk of oligohydramnios in smaller twin (OR = 2.44, 95% CI = 1.37-4.32, p < .01), cardiomegaly in larger twin (OR = 2.95, 95% CI = 1.01-8.60, p < .05), birth weight of either twin below the 10th percentile for gestational age (OR = 5.56, 95% CI = 2.67-11.59, p < .001), birth weight discordance > 25% (OR = 9.41, 95% CI = 4.46-19.87, p < .001), IUFD (OR = 3.26, 95% CI = 1.76-6.05, p < .001), and severe neonatal morbidity (OR = 1.83, 95% CI = 1.03-3.26, p < .05). The intact survival rate in discordant and concordant twin pairs was 70% and 89%, respectively (p < .001).

CONCLUSIONS

Early and increase fetal surveillance of the second-trimester AC discordant twins should be utilized to establish perinatal risks, thus allowing prenatal care to improve.

Development and validation of HERWIG 7 tunes from CMS underlying-event measurements

This paper presents new sets of parameters ("tunes") for the underlying-event model of the H E R W I G 7 event generator. These parameters control the description of multiple-parton interactions (MPI) and colour reconnection in H E R W I G 7 , and are obtained from a fit to minimum-bias data collected by the CMS experiment at s = 0.9 , 7, and 13 Te . The tunes are based on the NNPDF 3.1 next-to-next-to-leading-order parton distribution function (PDF) set for the parton shower, and either a leading-order or next-to-next-to-leading-order PDF set for the simulation of MPI and the beam remnants. Predictions utilizing the tunes are produced for event shape observables in electron-positron collisions, and for minimum-bias, inclusive jet, top quark pair, and Z and W boson events in proton-proton collisions, and are compared with data. Each of the new tunes describes the data at a reasonable level, and the tunes using a leading-order PDF for the simulation of MPI provide the best description of the data.

Remyelination is enhanced by Astragalus polysaccharides through inducing the differentiation of oligodendrocytes from neural stem cells in cuprizone model of demyelination

Demyelination is the hallmark of multiple sclerosis (MS). Promoting remyelination is an important strategy to treat MS. Our previous study showed that Astragalus polysaccharides (APS), the main bioactive component of Astragalus membranaceus, could prevent demyelination in experimental autoimmune encephalomyelitis mice. To investigate the effects of APS on remyelination and the underlying mechanisms, in this study we set up a cuprizone-induced demyelination model in mice and treated them with APS. It was found that APS relieved the neurobehavioral dysfunctions caused by demyelination, and efficaciously facilitated remyelination in vivo. In order to determine whether the mechanism of enhancing remyelination was associated with the differentiation of neural stem cells (NSCs), biomarkers of NSCs, astrocytes, oligodendrocytes and neurons were measured in the corpus callosum tissues of mice through Real-time PCR, Western blot and immunohistochemistry assays. Data revealed that APS suppressed the stemness of NSCs, reduced the differentiation of NSCs into astrocytes, and promoted the differentiation into oligodendrocytes and neurons. This phenomenon was confirmed in the differentiation model of C17.2 NSCs cultured in vitro. Since Sonic hedgehog signaling pathway has been proven to be crucial to the differentiation of NSCs into oligodendrocytes, we examined expression levels of the key molecules in this pathway in vivo and in vitro, and eventually found APS activated this signaling pathway. Together, our results demonstrated that APS probably activated Sonic hedgehog signaling pathway first, then induced NSCs to differentiate into oligodendrocytes and promoted remyelination, which suggested that APS might be a potential candidate in treating MS.

EpsR Negatively Regulates Streptococcus mutans Exopolysaccharide Synthesis

Streptococcus mutans is considered the primary etiological agent of human dental caries. Glucosyltransferases (Gtfs) from S. mutans play important roles in the formation of biofilm matrix and the development of cariogenic oral biofilm. Therefore, Gtfs are considered an important target to prevent the development of dental caries. However, the role of transcription factors in regulating gtf expression is not yet clear. Here, we identify a MarR (multiple antibiotic resistance regulator) family transcription factor named EpsR (exopolysaccharide synthesis regulator), which negatively regulates gtfB expression and exopolysaccharide (EPS) production in S. mutans. The epsR in-frame deletion strain grew slowly, aggregated more easily in the presence of dextran, and displayed different colony morphology and biofilm structure. Notably, epsR deletion resulted in altered 3-dimensional biofilm architecture, increased water-insoluble EPS production, and upregulated GtfB protein content and activity. In addition, global gene expression profiling revealed differences in the expression levels of 69 genes in which gtfB was markedly upregulated. The conserved DNA motif for EpsR binding was determined by electrophoretic mobility shift assay and DNase I footprinting assays. Moreover, analysis of β-galactosidase activity suggested that EpsR acted as a repressor and inhibited gtfB expression. Taken together, our findings indicate that EpsR is an important transcription factor that regulates gtfB expression and EPS production in S. mutans. These results add new aspects to the complexity of regulating the expression of genes involved in the cariogenicity of S. mutans, which might lead to novel strategies to prevent the formation of cariogenic biofilm that may favor diseases.

A6 THE ROLE OF TUFT CELLS IN INTESTINAL HOMEOSTASIS

Background

Intestinal epithelial cells may actively regulate homeostasis by recognizing and responding to extracellular signals. One of these cell types, tuft cells, has been proposed to have a role in secretion, absorption, and reception. However, their role in the intestine has not been fully characterized. We have found that tuft cells express the SH2 domain-containing inositol 5’-phosphatase (SHIP), which was formerly thought to be restricted to hematopoietic cells. SHIP negatively regulates PI3K-mediated cell growth, proliferation, and activation. Tuft cells secrete IL-25, which activates group 2 innate lymphoid cells (ILC2s), leading to type 2 immune responses. Tuft cells may contribute to inflammation in the intestine by increasing ILC2 numbers and/or activation, leading to type II inflammation.

Aims

My hypothesis is that SHIP inhibits tuft cell responses to innate immune stimuli by limiting PI3K activation. Moreover, SHIP deficiency will increase tuft cell responses to commensal microbes, causing ILC2-mediated type II inflammation. To investigate the role of SHIP in tuft cell responses in vivo, I will use a tuft cell-specific SHIP deficient mouse in the dextran sodium sulfate (DSS)-induced colitis model.

Methods

We created a mouse deficient in SHIP only in intestinal tuft cells (Fabpcre x SHIPfl/fl) to investigate the impact of SHIP deficiency in tuft cells on responses to luminal microbes. Tuft cell-specific SHIP deficient mice (8-week-old) and their wild type littermates were subjected to DSS-induced colitis for 7 days. Clinical disease activity was monitored daily and gross pathology, including total colon length, was examined at the experimental endpoint. The concentrations of pro-inflammatory type I and type II cytokines were assessed in colonic tissue homogenates via ELISA.

Results

During DSS-induced colitis, mice with SHIP deficient tuft cells had increased disease activity compared to their wild type littermates, particularly evident in their weight loss. Mice with SHIP deficient tuft cells also had significantly shorter colons than their wild type littermates. IL-25 concentrations (produced by tuft cells) were increased in full thickness colon homogenates from mice with SHIP deficient tuft cells. In contrast, pro-inflammatory cytokines IL-1β, IL-6, and TNF did not differ between genotypes. Thus, increased tuft cell activity due to SHIP deficiency correlated with increased disease severity during DSS-induced colitis.

Conclusions

SHIP deficiency in intestinal tuft cells leads to increased tuft cell activity and exacerbated colitis during DSS treatment. Tuft cells may contribute to inflammation via IL-25 production, leading to increased type II inflammation by ILC2s. In future studies, we will target IL-25 in this model to determine whether increased tuft cell IL-25 production plays a causal role in disease exacerbation.

Funding Agencies

NSERC

Fabrication of ternary AgBr/BiPO4/g-C3N4 heterostructure with dual Z-scheme and its visible light photocatalytic activity for Reactive Blue 19

A plasmonic photocatalyst of AgBr/BiPO₄/g-C₃N₄ was prepared. X-ray powder diffraction, Scanning electron microscope, Transmission electron microscopy, Fourier infrared spectroscopy, Ultraviolet Visible diffuse reflectance spectroscopy and photoluminescence emission spectra have been employed to determine the structure, morphology and optical property of the as-prepared AgBr/BiPO₄/g-C₃N₄ composite and analysis the reasons for improving photocatalytic efficiency. The optimal doping ratio of AgBr was 10 wt% by degrading 20 mg/L of Reactive Blue 19 (RB19) under visible light (λ > 420 nm), and 10 wt%AgBr/BiPO₄/g-C₃N₄ degraded 20 mg/L of RB19 to 2.59% at 40 min, which is ascribed to synergistic effects at the interface of AgBr, BiPO₄ and g-C₃N₄. The effect of catalyst dosage, initial concentration and initial pH of RB19 solution on photocatalytic efficiency was investigated. Four cycles of experiments were conducted. Finally, through the trapping experiment, we found that the main active factor for degrading RB19 in the photocatalytic process is O₂^-. The possible photocatalytic mechanism of AgBr/BiPO₄/g-C₃N₄ was discussed in connection with the synergistic effect of Ag and active substances at the AgBr/BiPO₄/g-C₃N₄ interface.

Nonfuel Antineutrino Contributions in the High Flux Isotope Reactor

Reactor neutrino experiments have seen major improvements in precision in recent years. With the experimental uncertainties becoming lower than those from theory, carefully considering all sources of ν ¯ e is important when making theoretical predictions. One source of ν ¯ e that is often neglected arises from the irradiation of the nonfuel materials in reactors. The ν ¯ e rates and energies from these sources vary widely based on the reactor type, configuration, and sampling stage during the reactor cycle and have to be carefully considered for each experiment independently. In this article, we present a formalism for selecting the possible ν ¯ e sources arising from the neutron captures on reactor and target materials. We apply this formalism to the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory, the ν ¯ e source for the the Precision Reactor Oscillation and Spectrum Measurement (PROSPECT) experiment. Overall, we observe that the nonfuel ν ¯ e contributions from HFIR to PROSPECT amount to 1% above the inverse beta decay threshold with a maximum contribution of 9% in the 1.8-2.0 MeV range. Nonfuel contributions can be particularly high for research reactors like HFIR because of the choice of structural and reflector material in addition to the intentional irradiation of target material for isotope production. We show that typical commercial pressurized water reactors fueled with low-enriched uranium will have significantly smaller nonfuel ν ¯ e contribution.

Measurement of single-diffractive dijet production in proton-proton collisions at s = 8 Te with the CMS and TOTEM experiments

Measurements are presented of the single-diffractive dijet cross section and the diffractive cross section as a function of the proton fractional momentum loss ξ and the four-momentum transfer squared t. Both processesp p → p X andp p → X p , i.e. with the proton scattering to either side of the interaction point, are measured, whereX includes at least two jets; the results of the two processes are averaged. The analyses are based on data collected simultaneously with the CMS and TOTEM detectors at the LHC in proton-proton collisions ats = 8 Te during a dedicated run withβ ∗ = 90 m at low instantaneous luminosity and correspond to an integrated luminosity of 37.5 nb - 1 . The single-diffractive dijet cross section σ jj p X , in the kinematic region ξ < 0.1 ,0.03 < | t | < 1 Ge 2 , with at least two jets with transverse momentump T > 40 Ge , and pseudorapidity | η | < 4.4 , is 21.7 ± 0.9 (stat) - 3.3 + 3.0 (syst) ± 0.9 (lumi) nb . The ratio of the single-diffractive to inclusive dijet yields, normalised per unit of ξ , is presented as a function of x, the longitudinal momentum fraction of the proton carried by the struck parton. The ratio in the kinematic region defined above, for x values in the range - 2.9 ≤ log 10 x ≤ - 1.6 , is R = ( σ jj p X / Δ ξ ) / σ jj = 0.025 ± 0.001 (stat) ± 0.003 (syst) , where σ jj p X and σ jj are the single-diffractive and inclusive dijet cross sections, respectively. The results are compared with predictions from models of diffractive and nondiffractive interactions. Monte Carlo predictions based on the HERA diffractive parton distribution functions agree well with the data when corrected for the effect of soft rescattering between the spectator partons.