[circ_BACH2 affects the malignant biological behavior of papillary thyroid cancer by regulating miR-370-3p]

Objective: To investigate the influence of circ_BACH2 on the malignant biological behavior of papillary thyroid cancer and its molecular mechanism. Methods: Cancer tissues and paracancer tissues of 51 patients with papillary thyroid carcinoma from the Fourth Central Hospital of Tianjin between 2017 and 2019 were collected. Reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR) was used to detect the expressions of circ_BACH2, miR-370-3p and G protein coupled receptor kinase interacting factor 1 (GIT1) mRNA in tissues and cells; flow cytometry to detect cell apoptosis and cell cycle; plate clone formation experiment to detect the number of cell clones; cell counting kit 8 (CCK-8) to detect cell proliferation; Transwell array to detect cell migration and invasion; western blot to detect protein expressions; dual luciferase report experiment to detect the targeting relationship between circ_BACH2, miR-370-3p and GIT1; the nude mouse tumor formation experiment to detect the effect of circ_BACH2 on tumors in mice. Results: Compared with adjacent tissues, the expressions of circ_BACH2 and GIT1 in papillary thyroid cancer tissues was increased, while the expression of miR-370-3p was decreased. Compared with Nthy-ori3-1 cells, the expressions of circ_BACH2 in papillary thyroid cancer cells TPC-1 and SW579 were increased, the mRNA and protein levels of GIT1 were increased, miR-370-3p expression was decreased. The expression level of GIT1 mRNA was negatively correlated with that of miR-370-3p (r=-0.634), and the expression level of circ_BACH2 was positively correlated with that of GIT1 (r=0.635). The expression level of circ_BACH2 was negatively correlated with that of miR-370-3p (r=-0.394, P＜0.05). Circ_BACH2 and miR-370-3p has a binding site at the 3' UTR of GIT1. After knocking down circ_BACH2, the proportion of G0/G1 cells in papillary thyroid cancer cells TPC-1 and SW579 was increased, the proportion of S-phase cells was decreased and the proportion of G2/M-phase cells did not change significantly. The cell absorbance value was lower than that in si-NC group. The number of cell clone formation was decreased (43±5 vs 100±6, 54±8 vs 100±9); the cell apoptosis rate was increased [(19.60±2.40)% vs (4.30±0.20)%, (18.10±2.10)% vs (5.10±0.23)%]; cell migration number was decreased (61±7 vs 134±15, 58±6 vs 112±11), the invasion number was also decreased (45±6 vs 113±11, 47±4 vs 92±9); the expressions of Snail and Twist1 were decreased, and the expression of E-cadherin was increased (P＜0.000). Inhibition of miR-370-3p expression reversed the effect of circ_BACH2 knockdown on proliferation, migration, invasion and apoptosis of thyroid papillary cancer cells. Overexpression of GIT1 reversed the effects of overexpression of miR-370-3p on proliferation, migration, invasion and apoptosis of thyroid papillary cancer cells. Mice injected with TPC-1 cells stably transfected with sh-circ_BACH2 showed a reduction in tumor volume [(535±91) mm3 vs (857±114) mm3] after 35 days of culture; tumor weight was decreased [(0.62±0.13) mg vs (1.06±0.15) mg, P＜0.05]; the expressions of circ_BACH2 and GIT1 were decreased, and the expression of miR-370-3p was increased in nude mouse tumor tissue. Conclusion: Silencing circ_BACH2 may inhibit the proliferation, migration and invasion of papillary thyroid cancer cells in vitro, promote cell apoptosis, and inhibit tumor growth in vivo through targeted regulation of miR-370-3p/GIT1.

Analysis of SARS-CoV-2 transmission in a university classroom based on real human close contact behaviors

Due to high-population density, frequent close contact, possible poor ventilation, university classrooms are vulnerable for transmission of respiratory infectious diseases. Close contact and long-range airborne are possibly main routes for SARS-CoV-2 transmission. In this study, taking a university classroom in Beijing for example, close contact behaviors of students were collected through a depth-detection device, which could detect depth to each pixel of the image, based on semi-supervised learning. Finally, >23 h of video data were obtained. Using Computational Fluid Dynamics, the relationship between viral exposure and close contact behaviors (e.g. interpersonal distance, relative facial orientations, and relative positions) was established. A multi-route transmission model (short-range airborne, mucous deposition, and long-range airborne) of infectious diseases considering real close contact behaviors was developed. In the case of Omicron, the risk of infection in university classrooms and the efficacy of different interventions were assessed based on dose-response model. The average interpersonal distance in university classrooms is 0.9 m (95 % CI, 0.5 m-1.4 m), with the highest proportion of face-to-back contact at 87.0 %. The risk of infection of susceptible students per 45-min lesson was 1 %. The relative contributions of short-range airborne and long-range airborne transmission were 40.5 % and 59.5 %, respectively, and the mucous deposition was basically negligible. When all students are wearing N95 respirators, the infection risk could be reduced by 96 %, the relative contribution of long-range airborne transmission increases to 95.6 %. When the fresh air per capita in the classroom is 24 m3/h/person, the virus exposure could be decreased by 81.1 % compared to the real situation with 1.02 m3/h/person. In a classroom with an occupancy rate of 50 %, after optimized arrangement of student distribution, the infection risk could be decreased by 62 %.

Lower Incidence of Dementia Following Cancer Diagnoses: Evidence from a Large Cohort and Mendelian Randomization Study

BACKGROUND

The reported inverse association between cancer and subsequent Alzheimer's disease and related dementias (ADRD) remains uncertain.

OBJECTIVES

To investigate the association between these common conditions of old age and explore possible causal factors.

DESIGN, SETTING, PARTICIPANTS AND MEASUREMENTS

We conducted a large population-based cohort analysis using data from 3,021,508 individuals aged 60 and over in the UK Clinical Practice Research Datalink (CPRD), over a period up to 30 years (1988-2018). Cox proportional hazards models were fitted to estimate hazard ratios (HR) for risk of dementia associated with previous cancer diagnosis. Competing risk models were employed to account for competing risk of death. Two-sample Mendelian Randomization analysis based on meta-analysis data from large-scale GWAS studies was also conducted.

RESULTS

In the CPRD cohort, 412,903 participants had cancer diagnosis and 230,558 were subsequently diagnosed with dementia over a median follow-up period of 7.9 years. Cancer survivors had a 25% lower risk of developing dementia (HR=0.75, 95% CI:0.74-0.76) after adjustment for potential confounders. Accounting for competing risk of death provided a sub-distribution HR of 0.56 (95% CI:0.55-0.56). Results were consistent for prevalent and incident cancer and different common cancer types. Two-sample Mendelian Randomization analysis, using 357 cancer-related instrumental single-nucleotide polymorphisms (SNPs) revealed evidence of vertical pleiotropy between genetically predicted cancer and reduced risk of Alzheimer's disease (OR=0.97,95% CI:0.95-0.99).

CONCLUSION

Our results provide strong epidemiological evidence of the inverse association between cancer and risk of ADRD and support the potential causal nature of this association via genetic instruments. Further investigations into the precise underlying biological mechanisms may reveal valuable information for new therapeutic approaches.

Student close contact behavior and COVID-19 transmission in China's classrooms

Classrooms are high-risk indoor environments, so analysis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission in classrooms is important for determining optimal interventions. Due to the absence of human behavior data, it is challenging to accurately determine virus exposure in classrooms. A wearable device for close contact behavior detection was developed, and we recorded >250,000 data points of close contact behaviors of students from grades 1 to 12. Combined with a survey on students' behaviors, we analyzed virus transmission in classrooms. Close contact rates for students were 37 ± 11% during classes and 48 ± 13% during breaks. Students in lower grades had higher close contact rates and virus transmission potential. The long-range airborne transmission route is dominant, accounting for 90 ± 3.6% and 75 ± 7.7% with and without mask wearing, respectively. During breaks, the short-range airborne route became more important, contributing 48 ± 3.1% in grades 1 to 9 (without wearing masks). Ventilation alone cannot always meet the demands of COVID-19 control; 30 m3/h/person is suggested as the threshold outdoor air ventilation rate in a classroom. This study provides scientific support for COVID-19 prevention and control in classrooms, and our proposed human behavior detection and analysis methods offer a powerful tool to understand virus transmission characteristics and can be employed in various indoor environments.

Local travel behaviour under continuing COVID-19 waves- A proxy for pandemic fatigue?

COVID-19 continues to threaten the world. Relaxing local travel behaviours on preventing the spread of COVID-19, may increase the infection risk in subsequent waves of SARS-CoV-2 transmission. In this study, we analysed changes in the travel behaviour of different population groups (adult, child, student, elderly) during four pandemic waves in Hong Kong before January 2021, by 4-billion second-by-second smartcard records of subway. A significant continuous relaxation in human travel behaviour was observed during the four waves of SARS-CoV-2 transmission. Residents sharply reduced their local travel by 51.9%, 50.1%, 27.6%, and 20.5% from the first to fourth pandemic waves, respectively. The population flow in residential areas, workplaces, schools, shopping areas, amusement areas and border areas, decreased on average by 30.3%, 33.5%, 41.9%, 58.1%, 85.4% and 99.6%, respectively, during the pandemic weeks. We also found that many other cities around the world experienced a similar relaxation trend in local travel behaviour, by comparing traffic congestion data during the pandemic with data from the same period in 2019. The quantitative pandemic fatigue in local travel behaviour could help governments partially predicting personal protective behaviours, and thus to suggest more accurate interventions during subsequent waves, especially for highly infectious virus variants such as Omicron.

Changes on local travel behaviors under travel reduction-related interventions during COVID-19 pandemic: a case study in Hong Kong

The emerging Omicron variant poses a serious threat to human health. Public transports play a critical role in infection spread. Based on the data of nearly 4 billion smartcard uses, between January 1, 2019 and January 31, 2021 from the Mass Transit Railway Corporation of Hong Kong, we analyzed the subway travel behavior of different population groups (adults, children, students and senior citizens) due to the COVID-19 pandemic and human travel behavior under different interventions (e.g. work suspension, school closure). Due to the pandemic, the number of MTR passengers (the daily number of passengers in close proximity in subway carriages) decreased by 37.4% (40.8%) for adults, 80.3% (78.5%) for children, 71.6% (71.6%) for students, and 33.5% (36.1%) for senior citizens. Due to work from home (school suspension), the number of contacted adults (students/children) in the same carriage during the rush hours decreased by 39.6% (38.6%/43.2%). If all workers, students, and children were encouraged to commute avoiding rush hours, the possible repeated contacts during rush hour of adults, children and students decreased by 73.3%, 77.9% and 79.5%, respectively. Since adults accounted for 87.3% of the total number of subway passengers during the pandemic, work from home and staggered shift pattern of workers can reduce the infection risk effectively. Our objective is to find the changes of local travel behavior due to the pandemic. From the perspective of public transports, the results provide a scientific support for COVID-19 prevention and control in cities.

Public concern for animal welfare and its correlation with ethical ideologies after coronavirus disease (COVID-19) in China

The outbreak of coronavirus disease (COVID-19) represents a major public health challenge and a serious threat to sustainable social development. A consideration of animal welfare is clearly justified, given the potential contribution of animals to the spread of the disease. The present study, therefore, sought to investigate the concern the Chinese people have for animal welfare (PCAW) and how their 'ethical ideology' (idealism and relativism) determines PCAW after COVID-19, through comparison with the same study, carried out in China in 2015. Our results demonstrated a significant improvement in Chinese PCAW after COVID-19. The adverse impact of COVID-19 may have resulted in a lowered idealism score and this decreased score served to neutralise significant correlations between idealism and PCAW, compared to the 2015 results. The global pandemic did not increase people's relativism score and a significant correlation was found between relativism and PCAW. Gender, age, educational level, public perception of animals after COVID-19, zoo and aquarium visiting were all shown to be predictor variables for PCAW. This study is one of the first to investigate Chinese PCAW after COVID-19 and can therefore provide knowledge that will potentially increase Chinese PCAW.

Close contact behavior-based COVID-19 transmission and interventions in a subway system

During COVID-19 pandemic, analysis on virus exposure and intervention efficiency in public transports based on real passenger's close contact behaviors is critical to curb infectious disease transmission. A monitoring device was developed to gather a total of 145,821 close contact data in subways based on semi-supervision learning. A virus transmission model considering both short- and long-range inhalation and deposition was established to calculate the virus exposure. During rush-hour, short-range inhalation exposure is 3.2 times higher than deposition exposure and 7.5 times higher than long-range inhalation exposure of all passengers in the subway. The close contact rate was 56.1 % and the average interpersonal distance was 0.8 m. Face-to-back was the main pattern during close contact. Comparing with random distribution, if all passengers stand facing in the same direction, personal virus exposure through inhalation (deposition) can be reduced by 74.1 % (98.5 %). If the talk rate was decreased from 20 % to 5 %, the inhalation (deposition) exposure can be reduced by 69.3 % (73.8 %). In addition, we found that virus exposure could be reduced by 82.0 % if all passengers wear surgical masks. This study provides scientific support for COVID-19 prevention and control in subways based on real human close contact behaviors.

The bipolar charge plasma spectrometer (BCPS) based on the 2π-field-of-view double-channel electrostatic analyzer

In this paper, we propose a bipolar charge plasma spectrometer based on the double-channel electrostatic analyzer for simultaneously measuring thermal ions and electrons with a 2π hemispherical field-of-view. Both ions and electrons within the wide field-of-view enter the spectrometer, pass through the variable geometric factor channel, and are then separated by the double-channel electric fields. Two microchannel plates are accommodated at the exit of the analyzer for ion and electron detection. The main performance of the spectrometer has been obtained from on-ground calibration. With the electrostatic deflectors and the cylindrically symmetric structure, the spectrometer provides simultaneous measurements of thermal ion and electron velocity distributions with a shared field-of-view of 360° (azimuth angle) by 90° (elevation angle) and a broad energy range for both ions and electrons. The ion analyzer constant and the electron analyzer constant are 11.1 and 9.7, respectively. The detecting energy range of 33.3-44.4 keV for ions and 29.1-38.8 keV for electrons can be obtained by using the sweeping electrostatic analyzer voltage range of 3-4000 V. The ion and electron energy resolutions are 9.6% and 6.1%, respectively. The variable geometric factor function provides a large geometric factor adjusting range for both ion and electron measurements by two orders of magnitude, which fulfills the requirements of a large dynamic flux range for simultaneous measurements of space thermal plasma in the solar wind and magnetosphere.

COVID-19 Vaccination Did Not Change the Personal Protective Behaviors of Healthcare Workers in China

Personal protective behaviors of healthcare workers (HCWs) and dynamic changes in them are known to play a major role in the hospital transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this study, 1,499 HCWs in Chinese hospitals completed an online survey about their knowledge on SARS-CoV-2 transmission and their personal protective behaviors before and after coronavirus disease 2019 (COVID-19) vaccination. Of all the respondents, 89% were vaccinated at the time of the survey and 96% believed that the vaccine was effective or highly effective. Further, 88% of the vaccinated HCWs expressed that they would get revaccinated if the vaccination failed. Compared with HCWs with a lower education level, those with a higher education level had less fear of being infected with SARS-CoV-2 and reported a lower negative impact of the pandemic on how they treated patients. Physicians and nurses were willing to believe that short-range airborne and long-range fomite are possible transmission routes. HCWs with a higher education level had a better knowledge of COVID-19 but worse personal protective behaviors. The fact that HCWs with a longer work experience had worse personal protective behaviors showed that HCWs gradually relax their personal protective behaviors over time. Moreover, vaccination reduced the negative effects of the COVID-19 pandemic on how the HCWs treated patients. Importantly, the survey revealed that after vaccination, HCWs in China did not relax their personal protective behaviors, and it may bring a low potential risk for following waves of variant virus (e.g., delta).

Associations of Cardiovascular and Non-Cardiovascular Comorbidities with Dementia Risk in Patients with Diabetes: Results from a Large UK Cohort Study

BACKGROUND

Type 2 diabetes (T2D) is an established risk factor for dementia. However, it remains unclear whether the presence of comorbidities could further increase dementia risk in diabetes patients.

OBJECTIVES

To examine the associations between cardiovascular and non-cardiovascular comorbidities and dementia risk in T2D patients.

DESIGN

Population-based cohort study.

SETTING

The UK Clinical Practice Research Datalink (CPRD).

PARTICIPANTS

489,205 T2D patients aged over 50 years in the UK CPRD.

MEASUREMENTS

Major cardiovascular and non-cardiovascular comorbidities were extracted as time-varying exposure variables. The outcome event was dementia incidence based on dementia diagnosis or dementia-specific drug prescription.

RESULTS

During a median of six years follow-up, 33,773 (6.9%) incident dementia cases were observed. Time-varying Cox regressions showed T2D patients with stroke, peripheral vascular disease, atrial fibrillation, heart failure or hypertension were at higher risk of dementia compared to those without such comorbidities (HR [95% CI] = 1.64 [1.59-1.68], 1.37 [1.34-1.41], 1.26 [1.22-1.30], 1.15 [1.11-1.20] or 1.10 [1.03-1.18], respectively). Presence of chronic obstructive pulmonary disease or chronic kidney disease was also associated with increased dementia risk (HR [95% CI] = 1.05 [1.01-1.10] or 1.11 [1.07-1.14]).

CONCLUSIONS

A range of cardiovascular and non-cardiovascular comorbidities were associated with further increases of dementia risk in T2D patients. Prevention and effective management of these comorbidities may play a significant role in maintaining cognitive health in T2D patients.

Weakening personal protective behavior by Chinese university students after COVID-19 vaccination

Personal protective behaviors and their dynamic change are known to play a major role in the community spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causal pathogen of the coronavirus disease 2019 (COVID-19) pandemic. In this study, a total of 3229 students in Chinese universities completed an online survey about their knowledge on transmission and personal protective behavior before and after COVID-19 vaccination. Of the respondents, 87.6% had been vaccinated. Most students believed that the large droplet (97.0%) and short-range airborne (89.3%) routes were the two most likely SARS-CoV-2 transmission routes, whereas only 24.1% considered long-range airborne transmission to be possible. Students who would be expected to possess better knowledge about virus transmission (e.g., students of medicine) reported better personal protective behaviors. Female students reported relatively better personal hygiene practices than male students, so did the confident students than their diffident peers. Students washed their hands on average of 5.76 times per day during the pandemic. Students at universities in southern regions washed their hands more frequently but paid less attention to indoor ventilation than did their northern counterparts. Interestingly, students who are fear of being infected had the bad personal hygiene. University students wore 22% less masks in public indoor environments after vaccination. Chinese university students weakened their personal protective behavior after vaccination and it may increase the potential risk of infection in the new waves of variant virus (e.g. delta).

Nitrogen doped titanium dioxide as an aesthetic antimicrobial filler in dental polymers

OBJECTIVE

To develop an aesthetic resin composite using a nitrogen-doped titanium dioxide (NTiO₂) filler that possesses antimicrobial properties against cariogenic bacteria.

METHODS

N-TiO₂ powder was manufactured by calcining commercial TiO₂ with urea. Free radical release from the N-TiO₂ powder under visible light irradiation was analysed using UV-Vis spectrophotometry. The N-TiO₂ powder was incorporated into a dental resin and the photocatalytic activity assessed using a dye under both visible light and dark conditions. Using XTT assay to measure the cellular metabolic activity, the antibacterial properties of the N-TiO₂ /resin composite discs were tested using Streptococcus mutans.

RESULTS

Doping nitrogen of TiO₂ resulted in a band gap shift towards the visible light spectrum, which enabled the powder to release reactive oxygen species when exposed to visible light. When incorporated into a dental resin, the N-TiO₂/resin composite still demonstrated sustained release of reactive oxygen species, maintaining its photocatalytic activity and showing an antibacterial effect towards Streptococcus mutans under visible light conditions.

SIGNIFICANCE

N-TiO₂ filled resin composite shows great promise as a potential aesthetic resin based adhesive for orthodontic bonding.

Analysis of efficacy of intervention strategies for COVID-19 transmission: A case study of Hong Kong

By the end of February 2021, COVID-19 had spread to over 230 countries, with more than 100 million confirmed cases and 2.5 million deaths. To control infection spread with the least disruption to economic and societal activities, it is crucial to implement the various interventions effectively. In this study, we developed an agent-based SEIR model, using real demographic and geographic data from Hong Kong, to analyse the efficiency of various intervention strategies in preventing infection by the SARS-CoV-2 virus. Close contact route including short-range airborne is considered as the main transmission routes for COVID-19 spread. Contact tracing is not that useful if all other interventions have been fully deployed. The number of infected individuals could be halved if people reduced their close contact rate by 25%. For reducing transmission, students should be prioritized for vaccination rather than retired older people and preschool aged children. Home isolation, and taking the nucleic acid test (NAT) as soon as possible after symptom onset, are much more effective interventions than wearing masks in public places. Temperature screening in public places only disrupted the infection spread by a small amount when other interventions have been fully implemented. Our results may be useful for other highly populated cities, when choosing their intervention strategies to prevent outbreaks of COVID-19 and similar diseases.

Evidence for lack of transmission by close contact and surface touch in a restaurant outbreak of COVID-19

BACKGROUND

Coronavirus disease 2019 (COVID-19) is primarily a respiratory disease that has become a global pandemic. Close contact plays an important role in infection spread, while fomite may also be a possible transmission route. Research during the COVID-19 pandemic has identified long-range airborne transmission as one of the important transmission routes although lack solid evidence.

METHODS

We examined video data related to a restaurant associated COVID-19 outbreak in Guangzhou. We observed more than 40,000 surface touches and 13,000 episodes of close contacts in the restaurant during the entire lunch duration. These data allowed us to analyse infection risk via both the fomite and close contact routes.

RESULTS

There is no significant correlation between the infection risk via both fomite and close contact routes among those who were not family members of the index case. We can thus rule out virus transmission via fomite contact and interpersonal close contact routes in the Guangzhou restaurant outbreak. The absence of a fomite route agrees with the COVID-19 literature.

CONCLUSIONS

These results provide indirect evidence for the long-range airborne route dominating SARS-CoV-2 transmission in the restaurant. We note that the restaurant was poorly ventilated, allowing for increasing airborne SARS-CoV-2 concentration.

Changes in local travel behaviour before and during the COVID-19 pandemic in Hong Kong

COVID-19 threatens the world. Social distancing is a significant factor in determining the spread of this disease, and social distancing is strongly affected by the local travel behaviour of people in large cities. In this study, we analysed the changes in the local travel behaviour of various population groups in Hong Kong, between 1 January and 31 March 2020, by using second-by-second smartcard data obtained from the Mass Transit Railway Corporation (MTRC) system. Due to the pandemic, local travel volume decreased by 43%, 49% and 59% during weekdays, Saturdays and Sundays, respectively. The local travel volumes of adults, children, students and senior citizens decreased by 42%, 86%, 73% and 48%, respectively. The local travel behaviour changes for adults and seniors between non-pandemic and pandemic times were greater than those between weekdays and weekends. The opposite was true for children and students. During the pandemic, the daily commute flow decreased by 42%. Local trips to shopping areas, amusement areas and borders decreased by 42%, 81% and 99%, respectively. The effective reproduction number (R t ) of COVID-19 had the strongest association with daily population use of the MTR 7-8 days earlier.

Cystatin C alleviates H2O2-induced H9c2 cell injury

OBJECTIVE

At present, the incidence of acute myocardial infarction is increasing year by year, and it has become one of the diseases with the highest mortality rate in humans. Myocardial ischemia-reperfusion injury (MIRI) is a major problem in the treatment of myocardial infarction, but clinically there is no effective way to treat MIRI. This study used Cystatin C (Cys C) to treat cardiomyocytes and rats to investigate the effect of Cys C on MIRI.

MATERIALS AND METHODS

We used H2O2 to induce rat cardiomyocytes (H9c2 cells) injury and stimulated the cells with Cys C. Cell counting kit 8 (CCK8) assay was used to determine the optimal concentration of H2O2 and Cys C to stimulate H9c2 cells. We determined the effects of Cys C on oxidative stress and apoptosis levels in H9c2 cells by measuring the activity of dehydrogenase (LDH), superoxide dismutase (SOD) and malondialdehyde (MDA), and the expression of apoptosis-related molecules (caspase3/8/9, Bax and Bcl-2). Changes in the activity of the NF-κB signaling pathway in H9c2 cells were also detected. In addition, we made rat MIRI models by ligating the coronary arteries and used Cys C to treat rats to verify the effect of Cys C on MIRI.

RESULTS

According to the results of the CCK8 assay, 1000 μM of H2O2 and 15 μM of Cys C were used to stimulate H9c2 cells. Cys C alleviated H2O2-induced H9c2 cell injury, manifested as a decrease in LDH and MDA activity and an increase in SOD activity. Cys C also reduced the apoptosis level in H9c2 cells. The activity of NF-κB signaling pathway in injured H9c2 cells was increased, and stimulation of Cys C could inhibit the NF-κB signaling pathway in H9c2 cells. The application of Cys C in MIRI rats also verified its therapeutic effect on MIRI.

CONCLUSIONS

Cys C reduced the oxidative stress and apoptosis levels of cardiomyocytes by inhibiting the activity of NF-κB signaling pathway in cardiomyocytes, thereby reducing cardiomyocyte injury and treating MIRI.

Performance and simulated moment uncertainties of an ion spectrometer with asymmetric 2π field of view for ion measurements in space

Space plasma instruments provide 3D particle velocity distribution functions. Because of telemetry limitations, these cannot be transmitted in high time resolution and the plasma needs to be characterized by moments of the velocity distribution function. These moment uncertainties have vital effects on the reliability and accuracy of onboard plasma moments. We assess the measurement accuracy for magnetosheath and solar wind ions using an ion spectrometer with an asymmetric field of view designed for the all-sky measurement of low-energy ions in the magnetosheath and solar wind. We focus on moment uncertainties for the ideal spectrometer, not considering the background counts, which may have considerable effects on the uncertainties in real life. To obtain number density, bulk velocity, and temperature, different orders of moments are integrated assuming a Maxwellian velocity distribution. Based on the design specifications, we use simulations to estimate systematic and random errors for typical plasma conditions. We find that the spectrometer resolution is adequate for determining the density of solar wind (∼7% error) and magnetosheath ions (∼4% error). The resolution is also adequate for determining the temperature of solar wind (∼10% error) and magnetosheath ions (∼2% error). For high speed flows with a bulk velocity of 750 km/s and a temperature of 20 eV, the maximum density and temperature errors become 9% and 7%, respectively. The bulk velocity errors are less than 2% for all cases. The contributions of heavy ions to the systematic errors are less than 5% for magnetosheath ions and less than 8% for solar wind ions.

Demographic and clinical factors associated with immune reconstitution in HIV/HBV co-infected and HIV mono-infected patients: a retrospective cohort study

OBJECTIVES

To describe the clinical characteristics and factors associated with CD4 T-cell count and CD4/CD8 ratio restoration in HIV mono-infected and HIV/HBV co-infected individuals, and to explore liver and renal functional changes in both groups.

METHODS

A retrospective cohort study was performed including 356 HIV/HBV co-infected and 716 HIV mono-infected participants who initiated antiretroviral therapy (ART) during 2013-2017 in Beijing Youan Hospital, China. Demographic and clinical characteristics were compared between the two groups, using χ² and Mann-Whitney non-parametric tests. Bivariate and multivariate Cox regression models were used to test their association.

RESULTS

Baseline HIV viral load and ART regimen were found to be significantly associated with CD4 T-cell restoration among HIV-infected participants, whereas baseline HIV viral load was the only significant factor associated with CD4 T-cell restoration in HIV/HBV co-infected participants. The final model showed that baseline HIV viral load and ART regimen were significantly associated with CD4/CD8 ratio restoration among HIV-infected participants, while baseline HIV viral load was the significant factor. Liver and renal functions were similar at the endpoint (P > 0.05).

CONCLUSIONS

Baseline HIV viral load count was found to be the key factor affecting immune restoration in both HIV and HIV/HBV individuals. Future multi-wave prospective studies are needed to clarify the potential biological mechanism.

[The value of left ventricular longitudinal strain in the diagnosis and differential diagnosis of myocardial amyloidosis]

Objective: To investigate the characteristics of left ventricular longitudinal strain (LS) in myocardial amyloidosis (CA), hypertrophic cardiomyopathy (HCM) and Fabry disease (FD), as well as the correlation between left ventricular LS and these diseases. Methods: A total of 14 CA patients, 28 HCM patients and 5 FD patients who visited the Department of Cardiology of the First Affiliated Hospital of Suzhou University from June 2017 to November 2019 were retrospectively included. EchoPAC software was used to analyze left ventricular LS, and univariate logistic regression analysis was used to analyze the correlation between echocardiographic LS indexes and various myocardial hypertrophy diseases. The receiver operating characteristic (ROC) curve was used to assess the sensitivity and specificity of echocardiograph LS indexes in the diagnosis of various myocardial hypertrophy diseases. Results: There were significant differences in LS of left ventricular basal segment, inferior wall, posterior wall, lateral wall and posterior septum among the three groups (P<0.05). The absolute value of LS in the left ventricular basal segment decreased in the CA group; the absolute value of LS in left ventricular posterior wall and lateral wall decreased significantly in the FD group (P<0.05); the absolute values of LS in left ventricular basal segment, inferior wall, posterior septum, lateral wall and posterior wall increased significantly in the HCM group (P<0.05). The absolute value of LS < 7.9% in the left ventricular basal segment, or > 13.2% in the inferior wall and > 9.2% in the basal segment, or < 8.3% in the lateral wall and < 7.9% in the posterior wall were the indicators of high sensitivity and specificity in the diagnosis of CA, HCM and FD, respectively. Conclusions: Left ventricular LS was an important index to differentiate myocardial hypertrophy. Combined with their respective clinical characteristics, it could provide certain reference value for clinical practice.

Impact of intervention methods on COVID-19 transmission in Shenzhen

By March 31, 2020, COVID-19 had spread to more than 200 countries. Over 750,000 confirmed cases were reported, leading to more than 36,000 deaths. In this study, we analysed the efficiency of various intervention strategies to prevent infection by the virus, SARS-CoV-2, using an agent-based SEIIR model, in the fully urbanised city of Shenzhen, Guangdong Province, China. Shortening the duration from symptom onset to hospital admission, quarantining recent arrivals from Hubei Province, and letting symptomatic individuals stay at home were found to be the three most important interventions to reduce the risk of infection in Shenzhen. The ideal time window for a mandatory quarantine of arrivals from Hubei Province was between 10 January and January 17, 2020, while the ideal time window for local intervention strategies was between 15 and 22 January. The risk of infection could have been reduced by 50% if all symptomatic individuals had immediately gone to hospital for isolation, and by 35% if a 14-day quarantine for arrivals from Hubei Province had been introduced one week earlier. Intervention strategies implemented in Shenzhen were effective, and the spread of infection would be controlled even if the initial basic reproduction number had doubled. Our results may be useful for other cities when choosing their intervention strategies to prevent outbreaks of COVID-19.

Prospective Evaluation of Cognitive Health and Related Factors in Elderly at Risk for Developing Alzheimer's Dementia: A Longitudinal Cohort Study

BACKGROUND

The CHARIOT PRO Main study is a prospective, non-interventional study evaluating cognitive trajectories in participants at the preclinical stage of Alzheimer's disease (AD) classified by risk levels for developing mild cognitive impairment due to AD (MCI-AD).

OBJECTIVES

The study aimed to characterize factors and markers influencing cognitive and functional progression among individuals at-risk for developing MCI-AD, and examine data for more precise predictors of cognitive change, particularly in relation to APOE ε4 subgroup.

DESIGN

This single-site study was conducted at the Imperial College London (ICL) in the United Kingdom. Participants 60 to 85 years of age were classified as high, medium (amnestic or non-amnestic) or low risk for developing MCI-AD based on RBANS z-scores. A series of clinical outcome assessments (COAs) on factors influencing baseline cognitive changes were collected in each of the instrument categories of cognition, lifestyle exposure, mood, and sleep. Data collection was planned to occur every 6 months for 48 months, however the median follow-up time was 18.1 months due to early termination of study by the sponsor.

RESULTS

987 participants were screened, among them 690 participants were actively followed-up post baseline, of whom 165 (23.9%) were APOE ε4 carriers; with at least one copy of the allele. The mean age was 68.73 years, 94.6% were white, 57.4% were female, and 34.8% had a Family History of Dementia with a somewhat larger percentage in the APOE ε4 carrier group (42.4%) compared to the non-carrier group (32.4%). Over half of the participants were married and 53% had a Bachelor's or higher degree. Most frequently, safety events typical for this population consisted of upper respiratory tract infection (10.4%), falls (5.2%), hypertension (3.5%) and back pain (3.0%). Conclusion (clinical relevance): AD-related measures collected during the CHARIOT PRO Main study will allow identification and evaluation of AD risk factors and markers associated with cognitive performance from the pre-clinical stage. Evaluating the psycho-biological characteristics of these pre-symptomatic individuals in relation to their natural neurocognitive trajectories will enhance current understanding on determinants of the initial signs of cognitive changes linked to AD.

High expression level of interleukin-1β is correlated with poor prognosis and PD-1 expression in patients with lung adenocarcinoma

PURPOSE

Cytokines are vital pro-inflammatory factors and involved in tumor immune infiltration, and immune infiltration is closely related to PD-1/PD-L1 blockades immunotherapy. This study aims to explore the associations between cytokines and prognosis and also PD-1/PD-L1 expression in early lung adenocarcinoma, which is seldom reported.

METHODS

324 early lung adenocarcinoma patients with prior surgical resection were included and the associations between overall survival time and clinical factors and also cytokines including IL-1β, IL-6 and TNF-α were analyzed by multivariate cox regression and Kaplan-Meier curve (log-rank test). Resected tumor samples were randomly obtained to detect the PD-1/PD-L1 expression by immunohistochemistry, and Chi square test was used for relations between cytokines and PD-1/PD-L1 expression.

RESULTS

In this study group, 26.2% patients showed a high level of IL-1β and patients with high IL-1β level showed 19 months shortened mOS than those with normal IL-1 β expression (mOS: 24.00, 95%CI 11.98-36.02 vs 43.00, 95% CI 37.37-48.63, p = 0.017). Among detected samples, the positive rate of PD-1 was 25.0% (13/52), and the positive rate of PD-L1 was 37.3% (19/52). The positive rate of PD-1 was 36.1% higher in high-IL-1 β-level group as compared to normal-IL-1β-level group (50.0% vs 13.9%, p = 0.012). No significant association was found between IL-1 β and PD-L1 expression.

CONCLUSION

High expression level of IL-1β was correlated with poor prognosis and higher positive rate of PD-1 expression, which gave us insights into biomarkers of survival prediction and immunotherapy in lung adenocarcinoma. Further studies were still needed.