[Clinical analysis of 9 children with refractory N-methyl-D-aspartate receptor antibody encephalitis children treated with tocilizumab]

Objective: To analyze the clinical features of children with refractory N-methyl-D-aspartate (NMDA) receptor antibody encephalitis treated with tocilizumab. Methods: Demographic and clinical manifeatations, immunotherapy and prognosis data of 9 children with refractory NMDA receptor antibody encephalitis who received tocilizumab in the Department of Pediatrics Neurology, XiangYa Hospital of Central South University from August 2021 to September 2023 were collected retrospectively. Prognosis was evaluated using the modified Rankin scale at initial diagnosis, at the initiation of tocilizumab treatment, and at the last follow-up. Treatment related complications, neuroimaging, and electroencephalography data were analyzed. Results: Among the 9 children, 6 were male and 3 were female, with an onset age of 4.2 (2.8, 8.7) years. At the onset of the disease, 9 children had a modified Rankin scale score of 5. When tocilizumab treatment was initiated, 7 children had a score of 5, and 2 children had a score of 4. The interval between the onset and initiation of tocilizumab treatment was 12 (5, 27) months, and the treatment frequency was 8 (5, 13) times. The follow-up time was 2.8 (1.5, 3.7) years. At the last follow-up, the symptoms of 9 children, including movement disorder, sleep disorder, consciousness disorder, silence and autonomic dysfunction, were improved to varying degrees, and none of them had seizures. At the last follow-up, 4 cases with a modified Rankin scale score of 0, 1 case with a score of 1, 2 cases with a score of 3, 1 case with a score of 4 and 1 case with a score of 5. The modified Rankin scale at the last follow-up was significantly different from that at the start of tocilizumab (Z=-2.56, P=0.014). All children had no serious adverse reactions during the treatment. Conclusions: After treatment with tocilizumab, the symptoms in patievts with refractory NMDA receptor antibody encephalitis, including movement disorder, sleep disorder, consciousness disorder, silence and autonomic dysfunction were improved, and none of them had seizures. The modified Rankin scale were improved, and the safety was good.

The COSPAR planetary protection policy for missions to Icy Worlds: A review of history, current scientific knowledge, and future directions

Recent discoveries related to the habitability and astrobiological relevance of the outer Solar System have expanded our understanding of where and how life may have originated. As a result, the Icy Worlds of the outer Solar System have become among the highest priority targets for future spacecraft missions dedicated to astrobiology-focused and/or direct life detection objectives. This, in turn, has led to a renewed interest in planetary protection concerns and policies for the exploration of these worlds and has been a topic of discussion within the COSPAR (Committee on Space Research) Panel on Planetary Protection. This paper summarizes the results of those discussions, reviewing the current knowledge and the history of planetary protection considerations for Icy Worlds as well as suggesting ways forward. Based on those discussions, we therefore suggest to (1) Establish a new definition for Icy Worlds for Planetary Protection that captures the outer Solar System moons and dwarf planets like Pluto, but excludes more primitive bodies such as comets, centaurs, and asteroids: Icy Worlds in our Solar System are defined as all bodies with an outermost layer that is believed to be greater than 50 % water ice by volume and have enough mass to assume a nearly round shape. (2) Establish indices for the lower limits of Earth life with regards to water activity (LLAw) and temperature (LLT) and apply them into all areas of the COSPAR Planetary Protection Policy. These values are currently set at 0.5 and -28 °C and were originally established for defining Mars Special Regions; (3) Establish LLT as a parameter to assign categorization for Icy Worlds missions. The suggested categorization will have a 1000-year period of biological exploration, to be applied to all Icy Worlds and not just Europa and Enceladus as is currently the case. (4) Have all missions consider the possibility of impact. Transient thermal anomalies caused by impact would be acceptable so long as there is less than 10-4 probability of a single microbe reaching deeper environments where temperature is >LLT in the period of biological exploration. (5) Restructure or remove Category II* from the policy as it becomes largely redundant with this new approach, (6) Establish that any sample return from an Icy World should be Category V restricted Earth return.

Atmospheric environment characteristic of severe dust storms and its impact on sulfate formation in downstream city

This study comprehensively investigated the impact of dust storms (DSs) on downstream cities, by selecting representative DS events. In this paper, we discussed the characteristics of meteorological conditions, air pollutants, PM2.5 components, and their influence on sulfate formation mechanisms. During DSs, strong winds, reaching speeds of up to 10 m/s, led to significant increases in PM10 and PM2.5, with maximum concentrations of 2684.5 and 429 μg/m3, respectively. Primary gaseous pollutants experienced substantial reductions, with decline rates of 48.1, 34.9, 36.8, and 9.0 % for SO2, NO2, NH3, and CO, respectively. Despite a notable increase in PM2.5 concentrations, only 7.6 % of the total mass of PM2.5 was attributed to ionic and carbonaceous components, a much lower value than observed before the DSs (77.3 %). Concentrations of Fe, Ti, and Mn exhibited increases by factors of 6.5-14.1, 10.4-17.0, and 1.6-4.7, respectively. In contrast to the significant decrease of >76.2 % in nitrogen oxidation ratio (NOR), sulfur oxidation ratio (SOR) remained at a relatively high level, displaying a strong positive correlation with high concentrations of Fe, Mn, and Ti. Quantitative analysis revealed an average increase of 0.187 and 0.045 μg/m3 in sulfate from natural sources and heterogeneous generation, respectively. The heterogeneous reaction on mineral dust was closely linked to atmospheric humidity, radiation intensity, the form of metal existence, and concentrations of it. High concentrations of titanium dioxide and iron‑manganese oxides in mineral dust promoted heterogeneous oxidation of SO2 through photocatalysis during the daytime and metal ion catalysis during the nighttime. This study establishes that the metal components in mineral dust promote heterogeneous sulfate formation, quantifies the yield of sulfate generated as a result, and provides possible mechanisms for heterogeneous sulfate formation.

Sudomotor dysfunction is associated with impaired left ventricular diastolic function in persons with type 2 diabetes: a cross-sectional study

BACKGROUND

The incidence of preserved ejection fraction heart failure has significantly increased in persons with type 2 diabetes mellitus (T2DM). Left ventricular (LV) diastolic dysfunction is an early and important manifestation of preserved ejection fraction heart failure. The onset of heart failure in persons with diabetes is associated with diabetic neuropathy. However, the relationship among sudomotor function, which is an early manifestation of small fiber neuropathy, and LV diastolic function remains unclear. This study aimed to explore the association between sudomotor function and LV diastolic function in persons with T2DM.

METHODS

In total, 699 persons with T2DM were enrolled and divided into three groups according to electrochemical skin conductance (ESC) assessed using the SUDOSCAN device: "no dysfunction" group (NSF), "moderate dysfunction" group (MDF), and "severe dysfunction" group (SDF). LV diastolic function was assessed using Doppler echocardiography. To evaluate the relationship between ESC and echocardiographic parameters, Pearson's correlation analysis was performed. Additionally, logistic regression analysis was used to determine the association between LV diastolic function and ESC. A receiver operating characteristic (ROC) curve was constructed to evaluate the performance of sudomotor function indicators in detecting impaired cardiac diastolic function.

RESULTS

There were 301 persons (43.06%) in the NSF group, 232 (33.19%) in the MDF group, and 166 (23.75%) in the SDF group. Compared to the NSF group, the MDF and SDF groups had higher A and E/e' and lower e' values (all p < 0.05). Pearson's correlation analysis showed that A and E/e' were negatively associated with foot ESC (FESC) and hand ESC (HESC), whereas e' was positively associated with FESC and HESC (all p < 0.05). After adjusting for confounding factors, binary logistic regression analysis showed that ESC was independently associated with impaired LV diastolic function (p = 0.003). The area under the ROC curve values for FESC and HESC were 0.621 and 0.635, respectively (both p < 0.05).

CONCLUSIONS

Deteriorating sudomotor function was associated with reduced diastolic function indicators. ESC can be used as a biomarker for detecting LV diastolic impairment.

Secondary Organic Aerosol Formation Potential from Vehicular Non-tailpipe Emissions under Real-World Driving Conditions

Traffic emissions are a dominant source of secondary organic aerosol (SOA) in urban environments. Though tailpipe exhaust has drawn extensive attention, the impact of non-tailpipe emissions on atmospheric SOA has not been well studied. Here, a closure study was performed combining urban tunnel experiments and dynamometer tests using an oxidation flow reactor in situ photo-oxidation. Results show a significant gap between field and laboratory research; the average SOA formation potential from real-world fleet is 639 ± 156 mg kg fuel-1, higher than the reconstructed result (188 mg kg fuel-1) based on dynamometer tests coupled with fleet composition inside the tunnel. Considering the minimal variation of SOA/CO in emission standards, we also reconstruct CO and find the critical role of high-emitting events in the real-world SOA burden. Different profiles of organic gases are detected inside the tunnel than tailpipe exhaust, such as more abundant C6-C9 aromatics, C11-C16 species, and benzothiazoles, denoting contributions from non-tailpipe emissions to SOA formation. Using these surrogate chemical compounds, we roughly estimate that high-emitting, evaporative emission, and asphalt-related and tire sublimation share 14, 20, and 10% of the SOA budget, respectively, partially explaining the gap between field and laboratory research. These experimental results highlight the importance of non-tailpipe emissions to atmospheric SOA.

Investigating the impact of high-altitude on vehicle carbon emissions: A comprehensive on-road driving study

This study addresses the literature gap concerning accurately identifying vehicle carbon emission characteristics in high-altitude areas. Utilizing a portable emission measurement system (PEMS) for real-world testing, we quantified the influence of altitude on carbon emissions from light-duty gasoline (LDGV) and diesel vehicles (LDDV). The Random Forest (RF) algorithm was employed to analyze the complex nonlinear relationships between altitude, meteorological conditions, driving patterns, and carbon dioxide (CO2) emissions, enabling predictions across different altitudes. The results showed that CO2 emissions progressively increase with elevation. Furthermore, as altitude increases, combustion efficiency declines, and the overall impact of driving conditions on emission rates diminishes. Altitude and meteorological factors significantly contributed to CO2 emissions, whereas driving conditions and road grades contributed less. Compared with the COPERT model, the RF model demonstrates strong accuracy in predicting carbon emissions at different altitudes. Specifically, the CO2 emission rate nearly triples as altitude increases from 2.0 km to 4.5 km. This research bridges a critical gap in the understanding carbon emissions from high-altitude vehicles, offering insights into policy development for emission reduction strategies in such regions. Future studies should integrate diverse testing methodologies and comprehensive surveys to validate and extend the findings.

Insights into PM2.5 pollution of four small and medium-sized cities in Chinese representative regions: Chemical compositions, sources and health risks

Fine particles (PM2.5) pollution is still a severe issue in some cities in China, where the chemical characteristics of PM2.5 remain unclear due to limited studies there. Herein, we focused on PM2.5 pollution in small and medium-sized cities in key urban agglomerations and conducted a comprehensive study on the PM2.5 chemical characteristics, sources, and health risks. In the autumn and winter of 2019-2020, PM2.5 samples were collected simultaneously in four small and medium-sized cities in four key regions: Dingzhou (Beijing-Tianjin-Hebei region), Weinan (Fenwei Plain region), Fukang (Northern Slope of the Tianshan Mountain region), and Bozhou (Yangtze River Delta region). The results showed that secondary inorganic ions (43.1 %-67.0 %) and organic matter (OM, 8.6 %-36.4 %) were the main components of PM2.5 in all the cities. Specifically, Fukang with the most severe PM2.5 pollution had the highest proportion of SO42- (31.2 %), while the dominant components in other cities were NO3- and OM. The Multilinear Engine 2 (ME2) analysis identified five sources of PM2.5 in these cities. Coal combustion contributed most to PM2.5 in Fukang, but secondary sources in other cities. Combined with chemical characteristics and ME2 analysis, it was preliminarily determined that the primary emission of coal combustion had an important contribution to high SO42- in Fukang. Potential source contribution function (PSCF) analysis results showed that regional transport played an important role in PM2.5 in Dingzhou, Weinan and Bozhou, while PM2.5 in Fukang was mainly affected by short-range transport from surrounding areas. Finally, the health risk assessment indicated Mn was the dominant contributor to the total non-carcinogenic risks and Cr had higher carcinogenic risks in all cities. The findings provide a scientific basis for formulating more effective abatement strategies for PM2.5 pollution.

Diagnostic and prognostic value of parameters of erector spinae in patients with uremic sarcopenia

AIM

This study aimed to investigate whether computed tomography (CT)-measured erector spinae parameters (ESPs) have diagnostic, severity assessment, and prognostic predictive value in uremic sarcopenia (US).

MATERIALS AND METHODS

A total of 202 uremic patients were enrolled and divided into two groups: a control group and a sarcopenia group. Sarcopenia was classified into two types: severe and nonsevere. The area, volume, and density of the erector spinae (ES) were measured using chest CT images, and the relevant ESP, including the erector spinae index (ESI), total erector spinae volume (TESV), erector spinae density (ESD), and erector spinae gauge (ESG) were calculated. The occurrence of adverse events was followed-up for 36 months. The diagnostic value and severity of US were determined using the receiver operating characteristic (ROC) curve. Survival curves diagnosed using CT were plotted and compared with the curve drawn using the gold standard. Cox regression analysis was used to identify independent risk factors associated with survival in US.

RESULTS

With an area under the curve (AUC) of 0.840 and 0.739, the combined ESP has diagnostic value and the ability to assess the severity of US. There was no significant difference in the survival curve between the combined ESP for the diagnosis of US and the gold standard (P > 0.05). ESI is a standalone predictor of survival in patients with US.

CONCLUSION

ESP measured by CT has diagnostic values for US and its severity, as well as being a predictive value for the prognosis of US.

Regenerative braking system effectively reduces the formation of brake wear particles

Brake wear particles (BWPs) are considered one of the most significant non-exhaust particle emission sources from motor vehicles. Previous studies have primarily focused on BWPs from conventional fuel vehicles (CFVs), with limited research available on BWPs from new energy vehicles (NEVs). We developed an independent BWP emission testing system applicable to NEVs and conducted BWP emission tests on representative NEVs and CFVs under various testing cycles via a chassis dynamometer. The BWP emission characteristics of the NEVs equipped with regenerative braking system significantly differed from those of gasoline vehicles. For transient emission characteristics, gasoline vehicles exhibited higher peak concentrations during brake events than brake drag events, while those with regenerative braking exhibited the opposite feature. Under continuous braking, the concentration of ultrafine particles emitted by NEVs was reduced by more than 3 orders of magnitude compared to gasoline vehicles. In terms of single-particle morphology, BWPs could be mainly divided into three categories: carbonaceous particles, iron-rich particles, and mixed metal particles. We obtained realistic emission characteristics of BWPs from NEVs, which could provide data support and a scientific basis for the formulation of relevant emission standards and control measures in the future.

Transforming waste brake pads from automobiles into Nano-Catalyst: Synergistic Fe-C-Cu triple sites for efficient fenton-like oxidation of organic pollutants

The arbitrary disposal of used brake pads from motor vehicles has resulted in severe heavy metal pollution and resource wastage, highlighting the urgent need to explore the significant untapped potential of these discarded materials. In this study, The in-situ growth of highly dispersed Fe2O3 nanocrystals was achieved by simple oxidation annealing of brake pad debris(BPD). Interestingly, Cu remained unoxidized and acted as a "valence state transformation bridge of Fe2O3" to construct the "triple Fe-C-Cu sites". The Fenton degradation experiment of pollutants was conducted under constant temperature conditions at 40 °C, a stirring rate of 1300 rpm, a pH value of 3, a catalyst dosage of 0.5 g/L, pollutant dosage ranging from 50 to 400 mg/L, and H2O2 dosage of 0.25 g/L. Experimental results showed that BPD treated at 300 °C for 2 h exhibited optimal Fenton-like oxidation activity, achieving rapid degradation of over 90 % of refractory antibiotics, such as tetracycline and ciprofloxacin, in organic wastewater within 10 min. This remarkable performance was mainly attributed to the synergistic effect of "Fe-C-Cu triple sites", where the electron-donating role of C in the Fe-C and Cu-C interfaces facilitated the conversion of the Fe(III) to Fe(II) and Cu(II) to Cu(I). In addition, the ability of Cu2+ to accept electrons at the Fe-Cu interface promoted the transition from Fe (II) to Fe (III). This "balance of electron gain and loss" accelerated the interfacial electron transfer and the recycle of dual Fenton sites, Fe(II)/Fe(III) and Cu(I)/Cu(II), to generate more ·OH from H2O2. Therefore, this strategy of functionalizing BPD as Fenton-like catalysts without the addition of external Fe provides intriguing prospects for understanding the construction of Fe-based Fenton catalysts and resource utilization of Fe-containing solid waste materials.

Direct measurement of brake and tire wear particles based on real-world driving conditions

With implementing vehicle emission control policies, tailpipe particulate emissions have been gradually controlled, and the relative contribution of non-tailpipe particulate emissions, such as brake and tire wear, has further increased. A unified and scientific method for sampling non-tailpipe particulate matter (PM) emissions is essential to improve the accuracy of the emission characteristics and factors. This study proposes a novel sampling method based on real-world driving conditions to obtain information on emissions and extract characteristic conditions for tire and brake pad wear. We extracted 200 representative braking segments for simulation experiments based on road type, initial and final velocities, temperature, and deceleration rate. Two standard test cycles to simulate the tire wear conditions of the front and rear wheels were constructed based on velocity, lateral, and vertical forces. Under the real-world driving condition test cycle, the emission factors of PM2.5 and PM10 for brake wear particles of passenger vehicles were 2.66 mg/km and 11.65 mg/km, respectively. In contrast, the emission factors of PM2.5 and PM10 for tire wear particles were 0.21 mg/km and 1.27 mg/km, respectively. Moreover, this study provides insights and basic data for localizing and improving the emission model, which can enhance its applicability and accuracy.

Chemical characteristics of fine tire wear particles generated on a tire simulator

Tire wear is one of the major sources of traffic-related particle emissions, however, laboratory data on the components of tire wear particles (TWPs) is scarce. In this study, ten brands of tires, including two types and four-speed grades, were chosen for wear tests using a tire simulator in a closed chamber. The chemical components of PM2.5 were characterized in detail, including inorganic elements, water-soluble ions (WSIs), organic carbon (OC), elemental carbon (EC), and polycyclic aromatic hydrocarbons (PAHs). Inorganic elements, WSIs, OC, and EC accounted for 8.7 ± 2.1%, 3.1 ± 0.7%, 44.0 ± 0.9%, and 9.6 ± 2.3% of the mass of PM2.5, respectively. The OC/EC ratio ranged from 2.8 to 7.6. The inorganic elements were dominated by Si and Zn. The primary ions were SO42- and NO3-, and TWPs were proven to be acidic by applying an ionic balance. The total PAHs content was 113 ± 45.0 μg g-1, with pyrene being dominant. In addition, the relationship between the chemical components and tire parameters was analyzed. Inorganic elements and WSIs in TWPs were more abundant in all-season tires than those in winter tires, whereas the content of PAHs was the opposite. The mass fractions of OC, Si, and Al in the TWPs all showed increasing trends with increasing tire speed grade, but the PAHs levels showed a decreasing trend. Ultimately, to provide more data for further research, a TWPs source profile was constructed considering the tire weighting factor.

Deep Learning and GAN-Synthesis for Auto-Segmentation of Pancreatic Cancer by Non-Enhanced CT for Adaptive Radiotherapy

PURPOSE/OBJECTIVE(S)

In conventional adaptive radiotherapy (ART) for pancreatic cancer, contrast-enhanced CT (CECT) helps to more precisely delineate primary gross tumor volume (GTV) than non-enhanced CT (NECT). However, frequent use of contrast medium can damage kidneys and prolong treatment time. Moreover, traditional manual delineation is labor-intensive and highly dependent on the experience of oncologists. Currently, automatic delineation based on deep learning with Generative Adversarial Networks (GAN)-based CT synthesis is one of the most feasible solutions to these problems.

MATERIALS/METHODS

A dataset of 35 pancreatic cancer patients was retrospectively collected from May 2021 to December 2022. All patients consist of a pair of NECT and CECT. We designed and developed an automatic delineation framework (Proposed) for GTV of pancreatic cancer based on Trans-cycleGAN and a modified 3D U-Net. TranscycleGAN can not only synthesize CECT from NECT, but can also augment the amount of CT images; then all real and synthesized CT images were used to train the modified 3D U-Net for automatic delineation of GTV; finally, our framework was able to automatically delineate GTV by NECT, but not only by CECT. Our framework was evaluated by dice similarity coefficient (DSC), 95% Harsdorff distance (95HD) and average surface distance (ASD) with oncologists' manual delineation ("gold standard").

RESULTS

The evaluation results were summarized in Table 1. The proposed framework achieved the best automatic delineation results by NECT, which was superior to that of CECT: 0.917 & 0.903 of DSC, 2.498mm & 3.029mm of HD95, 0.481mm & 0.534mm of ASD, p < 0.05 for DSC and HD95. Specifically, it is significantly superior to the automatic delineation results using U-Net by CECT 0.917 & 0.818 of DSC, 2.498mm & 13.228mm of HD95, 0.481mm & 3.633mm of ASD, p < 0.05 for DSC.

CONCLUSION

We proposed an automatic delineation framework for contouring GTV in ART of pancreatic cancer based on deep learning and Trans-cycleGAN network. This framework could automatically delineate GTV and achieve better performance with NECT compared to CECT. Our method could not only reduce the use of contrast medium, but also increase the precision and effectiveness of tumor delineation, which could have a positive impact on precision radiotherapy.

Efficacy and Safety of High-Dose Vitamin C Combined with Total Neoadjuvant Chemoradiotherapy in Locally Advanced Rectal Cancer (HCCSC R02 Study)

PURPOSE/OBJECTIVE(S)

Forpatients with locally advanced rectal cancer (LARC), the standard treatment is fluoropyrimidine (FU) -based neoadjuvant chemoradiotherapy (NCRT) combined with curative surgery. The CAO/ARO/AIO-04 trial and FORWARC trial reported that the addition of oxaliplatin to FU -based NCRT contributed to improve pathologic complete response (pCR), nevertheless, increased the acute therapeutic toxicity. Some studies showed that vitamin C (VitC) had potential benefits on anti-tumor therapy and anti-inflammatory response. Therefore, we conducted this HCCSC R02 study to explore the efficacy and safety of adding a high-dose intravenous VitC to mFOLFOX6/XELOX -based NCRT in LARC.

MATERIALS/METHODS

HCCSCR02 study was designed as a prospective, single-center phase II trial, which including pts aged 18-75 years with stage II/III rectal adenocarcinoma, distance from anus ≤12cm. The enrollment criteria included: staged with MRI as cT3/cT4 or cN1/2, or mesorectal fascia involvement (MRF+), or difficult to preserve the anus. Patients with glucose-6-phosphate dehydrogenase enzyme(G6PD) deficiency were excluded. Pelvic intensity modulated radiation therapy (IMRT) was given in 45-50.4Gy/25-28 fractions. Concurrently, two cycles of chemotherapy (mFOLFOX6 or XELOX) were administered during IMRT, as well as intravenous VitC (24g) delivered daily after the end of each radiation therapy. Additional 2-3 cycles of mFOLFOX6 / XELOX were adopted between the completion of radiotherapy and surgery. The primary endpoint was pCR rate. The secondary endpoints included radiation-related toxicities, overall survival (OS) and disease-free survival (DFS). This study is still recruiting.

RESULTS

From May 15, 2021 to Feb 8, 2023, 19 pts were recruited and finished all the scheduled NCRT, of which the proportion of cT4, cT3, cN2, cN1 were 31.6%, 63.2%, 52.6%, 36.8%, respectively. In addition, 10 pts (52.6%) were diagnosed as MRF+ initially, and 8 pts (42.1%) had a lower primary tumor(≤5cm) who were considered difficult for anal preservation before NCRT. All subjects enrolled were confirmed to be proficient mismatch repair (pMMR). As a result, 18 pts underwent a total mesorectal excision (TME) all with R0-resection, and 8 pts were evaluated as pCR (44.4%, 8/18, confidence interval: 0.246-0.663), 11 as major pathological response rate (MPR) (61.6%, 11/18), respectively. The anus preservation rate in patients with lower diseases was 87.5% (7/8). One case accepted a watch-and-wait strategy because of clinical complete response (cCR). Overall, grade 3 toxicities were observed in 4 pts, including 3 leucopenia (15.8%, 3/19), 2 neutropenia (10.5%, 2/19) and 1 diarrhea (5.3%, 1/19). No grade 4 adverse event was observed.

CONCLUSION

The addition of high-dose VitC to the mFOLFOX6/XELOX-based NCRT in LARC showed a promising pCR, well tolerance, particularly low rate of diarrhea, thus warrants further investigation.

CLINICAL TRIAL INFORMATION

NCT04801511.

PD-L1 Inhibitors Combined with Thoracic Radiotherapy in First-Line Treatment of Extensive Stage Small Cell Lung Cancer: A Propensity Score-Matched, Real-World Study

PURPOSE/OBJECTIVE(S)

The CREST study showed that the addition of thoracic radiotherapy (TRT) could improve the survival of extensive stage small cell lung cancer (ES-SCLC), but whether TRT can bring survival benefit in the era of immunotherapy is controversial. This study aims to explore the efficacy and safety of adding TRT to the combination of PD-L1 inhibitors and chemotherapy.

MATERIALS/METHODS

Thepatients who received PD-L1 inhibitors combined with platinum-based chemotherapy as the first-line treatment of ES-SCLC from January 2019 to December 2021 were retrospectively collected. According to whether they received TRT, they were divided into two groups, and the follow-up analysis was performed. Propensity score matching (PSM) in with a 1:1 ratio was performed to balance the baseline characteristics of the two cohorts. The endpoints were progression-free survival (PFS) and OS.

RESULTS

A total of 211 patients with ES-SCLC were enrolled, of whom 70 (33.2%) patients received standard therapy plus TRT as first-line treatment, and 141 (66.8%) patients in the control group received PD-L1 inhibitors plus chemotherapy. After PSM, a total of 65 pairs of patients were enrolled in the analysis. There were no significant differences in baseline characteristics between the two groups of patients who received TRT and those who did not. In all patients, the median PFS (mPFS) in the TRT group and the non-TRT groupwere 9.5 months and 7.2 months, respectively, with HR = 0.60 (95% CI 0.41-0.87, p = 0.007). The median OS (mOS) in the TRT group was also significantly longer than that in the non-TRT group (24.1 months vs. 18.5 months, HR = 0.53, 95% CI 0.32-0.85, p = 0.009). Multivariable analysis showed that baseline liver metastasis and bone metastasis were independent prognostic factors for OS. In terms of safety, immunotherapy combined with thoracic radiotherapy increased the incidence of treatment-related pneumonia (p<0.001), most of which were grade 1-2.

CONCLUSION

This real-world study shows that adding TRT to durvalumab or atezolizumab plus chemotherapy significantly improves survival in ES-SCLC. It leads to more treatment-related pneumonia, but most of them can be relieved after symptomatic treatment. This treatment model deserves to be explored in prospective clinical trials.

Heavy vehicles' non-exhaust exhibits competitive contribution to PM2.5 compared with exhaust in port and nearby areas

Heavy port transportation networks are increasingly considered as significant contributors of PM2.5 pollution compared to vessels in recent decades. In addition, evidence points to the non-exhaust emission of port traffic as the real driver. This study linked PM2.5 concentrations to varied locations and traffic fleet characteristics in port area through filter sampling. The coupled emission ratio-positive matrix factorisation (ER-PMF) method resolves source factors by avoiding direct overlap from collinear sources. In the port central and entrance areas, freight delivery activity emissions including vehicle exhaust and non-exhaust particles, as well as induced road dust resuspension, accounted for nearly half of the total contribution (42.5%-49.9%). In particular, the contribution of non-exhaust from denser traffic with high proportion of trucks was competitive and equivalent to 52.3% of that from exhaust. Backward trajectory statistical models further interpreted the notably larger-scale coverage of non-exhaust emissions in the port's central area. The distribution of PM2.5 were interpolated within the scope of the port and nearby urban areas, displaying the potential contribution of non-exhaust within 1.15 μg/m3-4.68 μg/m3, slightly higher than the urban detections reported nearby. This study may provide useful insights into the increasing percentage of non-exhaust from trucks in ports and nearby urban areas and facilitate supplementary data collection on Euro-VII type-approval limit settings.

Evaluating vehicular exhaust and evaporative emissions via VOC measurement in an underground parking garage

Vehicular emissions, including both tailpipe exhaust and evaporative emissions, are major anthropogenic sources of volatile organic compounds (VOCs) in urban cities. Current knowledge on vehicle tailpipe and evaporative emissions was mainly obtained via laboratory tests on very few vehicles under experimental conditions. Information on fleet gasoline vehicles emission features under real-world conditions is lacking. Here, VOC measurement was conducted in a large residential underground parking garage in Tianjin, China, to reveal the feature of the exhaust and evaporative emissions from real-world gasoline vehicle fleets. The VOC concentration in the parking garage was on average 362.7 ± 87.7 μg m-3, significantly higher than that in the ambient atmosphere at the same period (63.2 μg m-3). Aromatics and alkanes were the mainly contributors on both weekdays and weekends. A positive correlation between VOCs and traffic flow was observed, especially in the daytime. Source apportionment through the positive matrix factorization model (PMF) revealed that the tailpipe and evaporative emissions accounted for 43.2% and 33.7% of VOCs, respectively. Evaporative emission contributed 69.3% to the VOCs at night due to diurnal breathing loss from numerous parked cars. In contrast, tailpipe emission was most remarkable during morning rush hours. Based on the PMF results, we reconstructed a vehicle-related VOCs profile representing the combination of the tailpipe exhaust and evaporative emission from fleet-average gasoline vehicles, which could benefit future source apportionment studies.

Brake wear-derived particles: Single-particle mass spectral signatures and real-world emissions

Brake wear is an important but unregulated vehicle-related source of atmospheric particulate matter (PM). The single-particle spectral fingerprints of brake wear particles (BWPs) provide essential information for understanding their formation mechanism and atmospheric contributions. Herein, we obtained the single-particle mass spectra of BWPs by combining a brake dynamometer with an online single particle aerosol mass spectrometer and quantified real-world BWP emissions through a tunnel observation in Tianjin, China. The pure BWPs mainly include three distinct types of particles, namely, Ba-containing particles, mineral particles, and carbon-containing particles, accounting for 44.2%, 43.4%, and 10.3% of the total BWP number concentration, respectively. The diversified mass spectra indicate complex BWP formation pathways, such as mechanical, phase transition, and chemical processes. Notably, the mass spectra of Ba-containing particles are unique, which allows them to serve as an excellent indicator for estimating ambient BWP concentrations. By evaluating this indicator, we find that approximately 4.0% of the PM in the tunnel could be attributable to brake wear; the real-world fleet-average emission factor of 0.28 mg km^-1 veh^-1 is consistent with the estimation obtained using the receptor model. The results presented herein can be used to inform assessments of the environmental and health impacts of BWPs to formulate effective emissions control policies.

Characteristics, sources, and health risks of inorganic elements in PM2.5 and PM10 at Tianjin Binhai international airport

To study air pollution from aircraft activity at airport and its risks to human health, we conducted an experiment near Tianjin Binhai International Airport from November 11 to November 24, 2017. The characteristics, source apportionment, and health risk of inorganic elements in particles were determined in the airport environment. The mean mass concentrations of inorganic elements in PM₁₀ and PM_2.5 were 17.1 and 5.0 μg/m³, accounting for 19.0% of PM₁₀ mass and 12.3% of PM_2.5 mass, respectively. Inorganic elements, including arsenic, chromium, lead, zinc, sulphur, cadmium, potassium, sodium, and cobalt, were mainly concentrated in fine particulate matter. The particle number concentration within the 60-170 nm particle size range was significantly higher under polluted than non-polluted conditions. A principal component analysis revealed important contributions of Cr, Fe, K, Mn, Na, Pb, S, and Zn originating from airport activities, including aircraft exhaust, braking, tire wear, ground service equipment, and airport vehicles. Based on analyses of the non-carcinogenic and carcinogenic risks of heavy metal elements in PM₁₀ and PM_2.5, there were notable human health impacts, emphasising the importance of relevant research.

Optical properties of vehicular brown carbon emissions: Road tunnel and chassis dynamometer tests

Brown carbon (BrC), as an important light-absorbing aerosol, significantly impacts regional and global climate. Vehicle emission is a nonnegligible source of BrC, but the optical properties of BrC emitted from vehicles remain poorly understood. This study evaluates the absorption Ångström exponent (AAE) of traffic-related light-absorbing aerosols (i.e., AAE_Tr) and the absorption emission factor (EF_abs) of vehicular BrC via chassis dynamometer tests and a road tunnel measurement in Tianjin, China. AAE_Tr are estimated as 0.98-1.33 and 1.11 ± 0.001 for tested vehicles and on-road vehicle fleet, respectively. The AAE of vehicular BrC (AAE_BrC) is 3.83 ± 0.092 for on-road vehicle fleet. The vehicle technology updates effectively reduce the EF_abs of vehicular BrC. Among the four tested China 5 and China 6 gasoline vehicles in the chassis dynamometer tests, BrC EF_abs of China 5 gasoline direct injection vehicle is the highest, while China 6 mixing fuel injection vehicle exhibits the lowest EF_abs. The BrC EF_abs of on-road vehicle fleet at 370 nm wavelength are 0.081 ± 0.0058 m² kg^-1 for mixed fleet, 0.074 ± 0.018 m² kg^-1 for gasoline vehicles (GVs), and 1.66 ± 0.71 m² kg^-1 for diesel vehicles (DVs) in the tunnel measurement. EF_abs of GV fleet in the road tunnel is higher than China 5 and China 6 vehicles, as China 1-4 vehicles accounted for 26.8% of the total vehicle fleet in the tunnel. EF_abs of vehicular BrC are lower than those from biomass burning and coal combustion emissions. The light absorption of BrC from GVs and DVs accounts for 7.2 ± 2.1% and 1.5 ± 0.77% of total traffic-related absorption at 370 nm, respectively. Our study provides optical features of BrC from vehicle source and could contribute to estimating the impacts of vehicular aerosol emissions on global and regional climate change.

HISMD: A Novel Immune Subtyping System for HNSCC

Immune subtyping is an important way to reveal immune heterogeneity, which may contribute to the diversity of the progression and treatment in head and neck squamous cell carcinoma (HNSCC). However, reported immune subtypes mainly focus on levels of immune infiltration and are mostly based on a mono-omics profile. This study aimed to identify a comprehensive immune subtype for HNSCC via multi-omics clustering and build a novel subtype prediction system for clinical application. Data were obtained from The Cancer Genome Atlas database and our independent multicenter cohort. Multi-omics clustering was performed to identify 3 clusters of 499 patients in The Cancer Genome Atlas based on immune-related gene expression and somatic mutations. The immune characteristics and biological features of the obtained clusters were revealed by bioinformatics, and 3 immune subtypes were identified: 1) adaptive immune activation subtype predominantly enriched in T cells, 2) innate immune activation subtype predominantly enriched in macrophages, and 3) immune desert subtype. Subsequently, the clinical implications of each subtype were analyzed per clinical epidemiology. We found that adaptive immune activation showed better survival outcomes and had a similar response to chemotherapy with innate immune activation, whereas immune desert might be relatively resistant to chemotherapy. Moreover, a subtype prediction system was developed by deep learning with whole slide images and named HISMD: HNSCC Immune Subtypes via Multi-omics and Deep Learning. We endowed HISMD with interpretability through image-based key feature extraction. The clinical implications, biological significances, and predictive stability of HISMD were successfully verified by using our independent multicenter cohort data set. In summary, this study revealed the immune heterogeneity of HNSCC and obtained a novel, highly accurate, and interpretable immune subtyping prediction system. For clinical implementation in the future, additional validation and utility studies are warranted.

The impact of the metabolic score for insulin resistance on cardiovascular disease: a 10-year follow-up cohort study

PURPOSE

To investigate whether the metabolic score for insulin resistance (METS-IR) is associated with an increased risk of cardiovascular disease (CVD).

METHODS

A total of 6489 participants aged 35-70 years without a history of CVD were included in this prospective cohort study. The median follow-up time was 10.6 years. The METS-IR was calculated as ln [2 × FPG (mg/dL) + fasting TG (mg/dL)] × BMI (kg/m²)/ln [HDL-C (mg/dL)]. The primary outcome was CVD, defined as the composite of coronary heart disease (CHD) and stroke.

RESULTS

During follow-up, 396 individuals developed CVD. Kaplan-Meier survival curves by quintiles of METS-IR showed statistically significant differences (log-rank test, P < 0.001). Multivariate Cox regression analysis showed that the hazard ratio [95% confidence interval (95% CI)] of CVD was 1.80 (1.24-2.61) in quintile 5 and 1.17 (1.05-1.31) for per standard deviation (SD) increase in METS-IR. In subgroup analysis, the significant association between METS-IR and CVD was mainly observed among females and subjects without diabetes mellitus. A significant interaction was found between gender and METS-IR (P-interaction = 0.001). Moreover, adding METS-IR to models with traditional risk factors yielded a significant improvement in discrimination and reclassification of incident CVD.

CONCLUSION

The elevated METS-IR was independently associated with incident CVD, suggesting that the METS-IR might be a valuable indicator for risk stratification and early intervention of CVD.

Evaluating traffic emission control policies based on large-scale and real-time data: A case study in central China

The traffic control policies, including "Odd and Even" (OAE) and "One Day Per Week" (ODPW), were adopted in Zhengzhou, China. In this study, we use the bottom-up policy evaluation framework to capture the temporal-spatial characteristics of traffic conditions and vehicle emissions under various traffic restriction scenarios. Moreover, we use the street-scale simulation model to evaluate the effectiveness of improving air quality. Results showed that the improvements in traffic conditions led to the emission decrease by about 28.3 % for carbon monoxide (CO), 16.2 % for nitrogen oxide (NOx), 21.3 % for particulate matter (PM_2.5), and 23.2 % for total hydrocarbon (THC) under OAE. During ODPW, total vehicle emissions decreased by 14.1 % for CO, 10.2 % for NOx, 13.7 % for PM_2.5, and 12.4 % for THC. However, the spatial analysis indicates traffic restrictions could not significantly reduce those emissions caused by high traffic volume; besides, buses, middle-duty trucks, and heavy-duty trucks have partly offset the reduction benefit from restrictions. The air quality simulation results reveal no significant concentration decrease of CO and nitrogen dioxide (NO₂) in most areas. With the update of vehicles, stricter management of high-emission vehicles, and limited coverage for implementation of policies, the traffic control policies were not as effective as before. The limitations of the restriction policies are gradually prominent, and upgrade policies are urgently needed to continuously improve urban air quality in the future.

Dosimetric comparison of different intensity-modulated radiotherapy techniques for whole-breast irradiation of right-breast cancer

PURPOSE

This study compared the dosimetric parameters of field-in-field forward intensity-modulated radiotherapy (FIF-IMRT) and fixed-field inversely optimized intensity-modulated radiotherapy (FFIO-IMRT) for the whole-breast irradiation of patients undergoing right-breast lumpectomy.

MATERIAL AND METHODS

A total of 30 patients with pT1-2N0M0 right-breast invasive ductal carcinoma were enrolled in this study. Two different treatment plans, i.e., FIF-IMRT and FFIO-IMRT, were designed for each patient. The dosimetric parameters of the two treatment plans were compared including ipsilateral lung and heart, conformity index (CI), and the homogeneity index (HI) of the planning target volume (PTV).

RESULTS

Fixed-field inversely optimized intensity-modulated radiotherapy was found to significantly improve CI (83.302% vs. 60.146%) and HI (11.837% vs. 19.280%), and significantly reduced V₂₅ (18.038% vs. 19.653%) and V₃₀ (15.790% vs. 18.492%) of the ipsilateral lung. It also significantly increased V₅ (69.791% vs. 32.615%) of the ipsilateral lung and V₅ (61.579% vs. 3.829%), V₁₀ (14.130% vs. 0.381%), V₂₀ (1.843% vs. 0.051%), and D_mean (5.211Gy vs. 1.870Gy) of the heart.

CONCLUSION

Regardless of improving the conformity and homogeneity of PTV and reducing the ipsilateral lung irradiation volume at high doses, FFIO-IMRT significantly raised the ipsilateral lung irradiated volume at low doses, as well as the irradiation volume and mean radiation doses to the heart. This limits its use in patients with early-stage right breast cancer.

Comparison of CO2, NOx, and VOCs emissions between CNG and E10 fueled light-duty vehicles

In China, natural gas (NG) is the main vehicle fuel after gasoline and diesel, and the number of NG vehicles ranks first in the world. At present, there are many studies on the conventional gaseous pollutants and particulate matter of NG vehicles, but very few studies on their VOCs. In this study, the chassis dynamometer is used to test CNG/E10 bi-fuel light-duty vehicles, analyze the advantages of CNG in CO₂, fuel thermal efficiency, and cost, and discuss its disadvantages in NO_x emission. Most importantly, the emission characteristics and ozone formation potential of VOCs in the exhaust of CNG vehicles were analyzed in the study. Compared with E10, CNG fuel can reduce CO₂ emission by about 20 %, improve thermal efficiency by about 13 %, and save fuel costs by about 50 %. However, it will increase NO_x and NO₂ emissions by about 10 % and 13 % respectively. As for VOCs, the emission factor of VOCs from CNG fuel is about 54 % of E10 fuel. The VOCs group with the highest proportion in the exhaust of CNG-fueled vehicles is alkanes, >80 %. while the alkanes and alkenes with the highest proportion in E10 fuel are 30 % and 23 % respectively. C2 VOCs emitted by CNG account for >70 %, while C2 VOCs emitted by E10 are <60 %, followed by C4 VOCs, about 10 % - 30 %. The OFPs of VOCs in CNG exhaust is about 13.7 % of E10. Alkenes contribute the most to ozone, and the OFPs of alkenes in CNG and E10 vehicle exhaust accounts for about 55.3 % and 78.8 % of TVOCs respectively. The results of this study are helpful to improve people's understanding of the environmental value of using NG vehicles.

Adaptations to water stress and pastoralism in the Turkana of northwest Kenya

The Turkana people inhabit arid regions of east Africa-where temperatures are high and water is scarce-and they practice subsistence pastoralism, such that their diet is primarily composed of animal products. Working with Turkana communities, we sequenced 367 genomes and identified 8 regions putatively involved in adaptation to water stress and pastoralism. One of these regions includes a putative enhancer for STC1-a kidney-expressed gene involved in the response to dehydration and the metabolism of purine-rich foods such as red meat. We show that STC1 is induced by antidiuretic hormone in humans, is associated with urea levels in the Turkana themselves, and is under strong selection in this population (s∼0.041). This work highlights that partnerships with subsistence-level groups can lead to new models of human physiology with biomedical relevance.

Tunnel measurements reveal significant reduction in traffic-related light-absorbing aerosol emissions in China

Light-absorbing aerosols (LAA), including black carbon (BC) and brown carbon (BrC), profoundly impact regional and global climate. Vehicle emission is an important source of LAA in urban areas, but real-world emission features of LAA from the urban vehicle fleet are not fully understood. This study evaluates traffic-related BC and BrC emission factors (EFs) and their vehicular emission inventories via road tunnel measurements in Tianjin, China, in 2017 and 2021. The distance-based and fuel-based EFs of BC for the mixed fleet were 1.05 ± 1.28 mg km^-1 veh^-1 and 0.057 ± 0.057 g (kg-fuel)^-1, respectively, in 2021, with a dramatic decrease of 80.6 % compared to those in 2017. The BC EFs for gasoline vehicles (GVs, including traditional gasoline and hybrid vehicles) and diesel vehicles (DVs) were 0.55 ± 0.065 mg km^-1 veh^-1 and 10.5 ± 2.52 mg km^-1 veh^-1, respectively, in 2021. Compared to 2017, the BrC EFs also decreased significantly in 2021, by 10.8-53.6 %, with 0.32 ± 0.45 mg km^-1 veh^-1 and 0.018 ± 0.020 g (kg-fuel)^-1 of distance-based and fuel-based EFs for mixed fleet. The BrC EFs for GVs and DVs were 0.091 ± 0.024 mg km^-1 veh^-1 and 3.06 ± 0.91 mg km^-1 veh^-1, respectively, in 2021. Based on the BC and BrC EFs for GVs and DVs and annual mileage for each vehicle category, the annual vehicular LAA emission inventories were estimated. From 2017 to 2021, the annual vehicular LAA emissions in Tianjin have been significantly reduced, by 69 % for BC and 10 % for BrC. DVs account for a small amount of the vehicle population (8.4 %), but contribute to most of the BC (83 %) and BrC (86 %). Our study demonstrates the significant reduction of vehicular light-absorbing aerosols emission due to vehicle pollution prevention and control in China.

Lattice distortions and the metal-insulator transition in pure and Ti-substituted Ca3Ru2O7

We report pair distribution function studies on the relationship between the metal-insulator transition (MIT) and lattice distortions in pure and Ti-substituted bilayer Ca₃Ru₂O₇. Structural refinements performed as a function of temperature, magnetic field and length scale reveal the presence of lattice distortions not only within but also orthogonal to the bilayers. Because of the distortions, the local and average crystal structure differ across a broad temperature region extending from room temperature to temperatures below the MIT. The coexistence of distinct lattice distortions is likely to be behind the marked structural flexibility of Ca₃Ru₂O₇under external stimuli. This observation highlights the ubiquity of lattice distortions in an archetypal Mott system and calls for similar studies on other families of strongly correlated materials.

[Thirty-year changes in disability adjusted life years for colorectal cancer in China: a screening perspective analysis]

Objective: From a screening-focused perspective, to analyze the 30-year changes in disability adjusted life years (DALYs) caused by colorectal cancer (CRC) in China and in some other selected populations, to inform extent of burden of CRC and future related prevention and control in populations in China. Methods: Based on the data of Global Burden of Disease 2019 (GBD 2019), the DALYs, world standardized DALY rate, and the composition of different subgroups in China were collected. Joinpoint regression model was used to analyze the trend during 1990-2019, and comparison was made with the international data and population screening situation. The trend of DALY burden caused by CRC in China was predicted. Results: In 2019, the DALYs due to CRC in China was 6.395 million person-years, accounting for 26.3% of the global burden and 9.5% of all cancers burden in China; the DALYs in men accounted for 65.2%, in those aged ≥65 years old accounted for 44.8%, in the age group recommended by local screening guidelines (40-75 years) accounted for 73.7%. The years lived with disability accounted for 4.8%. Compared with 1990, the CRC-caused DALYs in China increased by 181.5% in 2019. Factors with the largest increase in the attributable percentage were high Body Mass Index (151.1%), diet high in red meat (86.4%) and diet high in processed meat (78.8%), etc. For DALY rate, it was 245.6/100 000 in 1990 and 320.6/100 000 in 2019, an increase of 30.5%. For reference, Australia (began in 2006), the UK (2006), and Japan (1992), where CRC population-wide screening has been conducted, had decreases in DALY rate of 36.0%, 28.6%, and 17.8%, respectively. The predication of DALYs suggested that without continued expansion of population-based screening, the DALYs in China would reach 7.7 million person-year-9.1 million person-year by 2030, an increase of 19.9%-41.8% compared with 2019. Conclusions: The burden of CRC-caused DALYs in China increased over the past 30 years, and would become more serious because of population aging and the concomitant disability problem. The age range recommended by the current local screening guideline could theoretically include 70% of the population from which the DALYs burden originates, however, the real-world population screening coverage is still limited. The observed decline in CRC-related DALY rate in selected countries was substantially due to the implementation of mass screening, indicating the importance of speedily expanding the population coverage of CRC screening in China.

Diagnostic accuracy of ultrasonography for detecting gastric tube placement: an updated meta-analysis

OBJECTIVE

This study aimed at reviewing the diagnostic accuracy of ultrasonography for detecting correct nasogastric tube placement compared with X-ray imaging as the reference standard.

MATERIALS AND METHODS

This was a systematic review and meta-analysis of observational studies published between 1961 and 2022. We included studies that compared the diagnostic accuracy of ultrasound detection for nasogastric tube placement with that of X-ray imaging in adult patients who were undergoing nasogastric tube placement for any reason. We searched for published studies in the following electronic databases: Cochrane Library, PubMed, EMBASE, and Web of Science. The risk of bias was assessed using a standard procedure according to the Quality Assessment of Diagnostic Accuracy Studies-2 criteria. The results were analyzed using RevMan or Meta-Disc software to determine the adequacy and conclusiveness of the available evidence.

RESULTS

Fourteen studies met our inclusion criteria. Overall, 1,812 patients were included in these studies. The results included a pooled sensitivity of 0.96 (95% confidence interval [CI] 0.94-0.97), specificity of 0.91 (95% CI 0.85-0.96), positive likelihood ratio of 5.08 (95% CI 1.49-17.39), and negative likelihood ratio of 0.08 (95% CI 0.06-0.10). This was confirmed through a summary receiver operating characteristic curve, which showed that the area under the curve was 0.96.

CONCLUSIONS

We found evidence about validity of ultrasound as an efficient method for verifying nasogastric tube placement, although there is insufficient evidence to suggest that it can be used as a diagnostic tool for incorrect gastric tube placement.

The effect of black carbon aging from NO2 oxidation of SO2 on its morphology, optical and hygroscopic properties

Atmospheric aging of black carbon (BC) leads to changes in its physiochemical properties, exerting complex effects on environment and climate. In this study, we have conducted laboratory chamber experiments to investigate the effects of BC aging on its morphology, hygroscopicity and optical properties by exposing monodisperse fresh BC particles to ambient ubiquitous species of nitrogen dioxide (NO₂), sulfur dioxide (SO₂) and ammonia (NH₃) in absence of UV light. We show a rapid aging from highly fractal to compacted aggregates for the monodisperse BC particles with an initial diameter of 150 nm, with decline in the dynamic shape factor (χ) from about 1.8 to nearly 1. The effective density of the monodisperse BC particles increases from ∼0.54 to 1.50 g cm^-3 accordingly. The aging process leads to that the light scattering, absorption, and single scattering albedo of the monodisperse BC particles are strongly enhanced by factors of 7.0, 1.8 and 3.0 respectively. By comparing with the BC aging from other mechanisms, we reveal a critical role of the composition of the coating materials on BC in determining its light absorption enhancement. Moreover, due to strong water uptake capacity of the aged BC particles, the light absorption enhancement (E_abs) could be 40-60% higher at humid atmosphere compared with dry conditions. This BC aging process from NO₂ oxidation of SO₂ may occur commonly in polluted regions and thus considerably alter its effects on regional air quality and climate.

Applying machine learning to construct braking emission model for real-world road driving

Brake emissions from vehicles are increasing as the number of vehicles increases. However, current research on brake emissions, particularly the intensity and characteristics of emissions under real road conditions, is significantly inadequate compared to exhaust emissions. To this end, a dataset of 600 (200 unique real-world braking events simulated using three types of brake pads) real-world braking events (called brake pad segments) was constructed and a mapping function between the average brake emission intensity of PM2.5 from the segments and the segment features was established by five algorithms (multiple linear regression (MLR) and four machine learning algorithms). Based on the five algorithms, the importance of the different features of the fragments was discussed and brake energy intensity (BEI) and metal content (MC) of the brake pad emissions were identified as the most significant factors affecting brake emissions and used as the final modeling features. Among the five algorithms, categorical boosting (CatBoost) had the best prediction performance, with a mean R2 and RMSE of 0.83 and 0.039 respectively for the tenfold cross-validation. In addition, the CatBoost-based model was further compared with the MOVES model to demonstrate its applicability. The CatBoost-based model has better prediction performance than the MOVES model. The MOVES model overpredicts brake fragment emissions for urban roads and underpredicts brake fragment emissions for motorways. Furthermore, the CatBoost-based model was interpreted and visualized by an individual conditional expectation (ICE) plot to break the machine learning "black box", with BEI and MC showing nonlinear monotonic increasing relationships with braking emissions. ICE plot also provides viable technical solutions for controlling brake emissions in the future. Both avoiding aggressive braking driving behavior (e.g., the application of smart transportation technologies) and using brake pads with less metal content (e.g., using ceramic brake pads) can effectively reduce brake emissions. The construction of a machine learning-based brake emission model and the white-boxing of its model provide excellent insights for the future detailed assessment and control of brake emissions.

[China guideline for the screening, early detection and early treatment of gastric cancer (2022, Beijing)]

Gastric cancer (GC) is a major digestive tract malignancy in China, which seriously threatens the health of Chinese population. A large number of researches have demons-trated that screening, early detection and early treatment are effective in reducing the incidence and mortality of GC. The development of the guideline for GC screening, early detection and early treatment in line with epidemic characteristics of GC in China will greatly promote the homogeneity and standardization, and improve the effect of GC screening. This guideline was commissioned by the Bureau of Disease Control and Prevention of the National Health Commission. The National Cancer Center of China initiated and convened a working group comprising multidisciplinary experts. Following the World Health Organization Handbook for Guideline Development, this guideline combined the most up-to-date evidence of GC screening, China's national conditions, and practical experience in cancer screening. This guideline provided evidence-based recommendations with respect to the screening population, technology and procedure management, aiming to improve the effect of GC screening and provide scientific evidence for the GC prevention and control in China.

Two-step aggregation of gold nanoparticles based on charge neutralization for detection of melamine by colorimetric and surface-enhanced Raman spectroscopy platform

A colorimetric and surface-enhanced Raman scattering (SERS) signal amplification platform based on 2-step aggregation of gold nanoparticles (AuNP) was constructed for the sensitive detection of melamine. In this study, the positively charged SYBR Green I was used for the first step of aggregation of AuNP, via charge neutralization, to obtain small-sized AuNP aggregates. The positively charged SYBR Green I decreased the negative charges of the surface of AuNP, which was beneficial to the aggregation of AuNP. In addition, the melamine could aggregate AuNP by decreasing the negative charges of the surface of AuNP and self-assemble with each other on the surface of AuNP by hydrogen bonds. Therefore, the second efficient aggregation of small-sized AuNP aggregates could be achieved with melamine at low concentration, resulting in significant signal changes of color and SERS. The sensitivity of a colorimetric (0.60 mg/L) and SERS (0.089 mg/L) platform, based on 2-step aggregation of AuNP, was 15 and 2.2 times higher than that based on 1-step aggregation of AuNP for detecting melamine.

Determining factors and parameterization of brake wear particle emission

Brake wear emission contributes to an increasingly significant proportion of vehicle-related particulate matter, but knowledge of its emission features and determining factors is still highly insufficient. Here, brake dynamometer experiments were conducted under controlled variables tests and real-world driving conditions to systematically investigate brake wear particle (BWP) emission. Compared to the decelerating process, the separating of pads and disc releases more BWPs, accounting for 47-76% of the total PM_2.5 mass. Particle number and mass distributions exhibit bimodal (< 0.01 µm and 0.8-1.2 µm) and unimodal (2-5 µm) patterns, respectively. Larger speed reduction exponentially amplifies BWP emission, and the significant enhancement of nanoparticles is proved to be related to the evaporation of organic constituents in the pads with threshold ranging from 170 °C to 270 °C. Emissions from front and rear brake assemblies don't agree with braking torque distribution, mainly attributive to the different braking pressures. A parameterization scheme for BWP emission based on kinetic energy loss is further established and proved to sufficiently predict the variation of BWP under real-world driving conditions. Being corrected by 1.8th power of the initial speed, the scheme improves the prediction.

[China guideline for the screening, early detection and early treatment of esophageal cancer (2022, Beijing)]

Esophageal cancer (EC) is a major digestive tract malignancy in China, which seriously threatens the health of Chinese population. A large number of researches have demonstrated that screening and early detection are effective in reducing the incidence and mortality of EC. The development of the guideline for EC screening and early detection in line with epidemic characteristics of EC in China will greatly promote the homogeneity and standardization, and improve the effect of EC screening. This guideline was commissioned by the Bureau of Disease Control and Prevention of the National Health Commission. The National Cancer Center of China initiated and convened a working group comprising multidisciplinary experts. Following the World Health Organization Handbook for Guideline Development, this guideline combined the most up-to-date evidence of EC screening, China's national conditions, and practical experience in cancer screening. This guideline provided evidence-based recommendations with respect to the screening population, technology and procedure management, aiming to improve the effect of EC screening and provide scientific evidence for the EC prevention and control in China.

POS1368 DIVERSITY OF HEMODYNAMIC TYPES IN CONNECTIVE TISSUE DISEASE ASSOCIATED PULMONARY HYPERTENSION: MORE THAN A SUBGROUP OF PULMONARY ARTERIAL HYPERTENSION

Background

Connective tissue disease (CTD) associated pulmonary hypertension (PH) is classified as a subgroup of WHO group 1 PH, also called pulmonary arterial hypertension (PAH). However, not all CTD-PH fit the hemodynamic definition of PAH. This study investigates the diversity of hemodynamical types of CTD-PH, their different clinical characteristics and outcomes.

Objectives

This study investigates the diversity of hemodynamical types of CTD-PH, their different clinical characteristics and outcomes.

Methods

We performed a retrospective cohort study. CTD-PH patients underwent right heart catheterization (RHC) were enrolled and divided into WHO group1 PH, WHO group 2 PH and high output PH (PVR<3WU and PAWP<15mmHg) according to hemodynamic features. Patients with obvious lung diseases, left heart disease and pulmonary embolism were excluded. Baseline characteristics, inflammatory markers, autoantibodies, cardiac function status, echocardiogram parameters, hemodynamics and survival rates were compared.

Results

207 CTD-PH patients were included, including 139 in WHO group 1 PH, 36 in WHO group 2 PH and 32 in high output PH. Incidence of anti-ribonucleoprotein antibody was lower in WHO Group 2 PH. High output PH is less severe, presenting lower NT-proBNP level, better WHO functional class, lower mPAP and PVR, higher cardiac output, and less cardiac remodeling. Among patients with elevated PAWP, combine pre& post-capillary PH had higher mPAP and larger right ventricle diameter. Association of mild to moderate interstitial lung disease didn’t show significant difference in disease characteristics. Short-term survival was significantly worse in WHO group 2 PH, yet 5-year survival rates didn’t differ between groups.

Conclusion

Pre-capillary PH is not the only hemodynamic type of CTD-PH. Different types of CTD-PH present different clinical phenotypes and outcome. Carefully phenotyping PH in CTD-PH patients is important.

Disclosure of Interests

None declared

POS0453 EXPLORATORY IMMUNOPHENOTYPE OF THE RARE DISEASE JUVENILE SJÖGREN’S SYNDROME REVEALS A DYSREGULATION OF B AND T MEMORY CELL FREQUENCIES

Background

Sjögren’s syndrome (SS) is an autoimmune rheumatic disease characterised by dryness resulting from chronic lymphocytic infiltration of the exocrine glands. Patients also present with other extraglandular manifestations such as arthritis, anemia and fatigue or various organ and systems involvement. The disease is more frequent in women aged 30-50. However, in rare cases, the disease starts in childhood and is known as juvenile SS (JSS) or childhood SS. Children have different clinical manifestations compared to adults, with dryness being less common, making the diagnosis very challenging1.

Objectives

To investigate in depth the immune cell profile of patients with JSS for better understanding of disease pathogenesis.

Methods

Peripheral blood was collected from a cohort of patients with JSS while attending appointments at UCLH clinics. None had received B-cell depletion therapy. Immune-phenotyping of 29 immune-cell subsets, including B and T cells, in peripheral blood from patients with JSS (n=10) and age and sex-matched healthy controls (n=10) was performed using flow cytometry as we have performed previously for patients with adult onset SS2. Data were analysed using multiple t-tests and compared with the adult SS immune phenotype.

Results

Patients with JSS had an average age of 18 years (range 16-21) with an average age of disease onset at 14 years (range 12-18). Up to 60% of patients presented Anti-Ro autoantibodies while 50% presented Anti-La autoantibodies.

Patients with JSS had an altered immune profile compared to age matched healthy controls (average of 18 years, range 15-25). In the B cell compartment, JSS patients had higher frequencies of Total CD19+ B cells (p=0.0044), Naïve B cells (CD19+IgD+CD27-) (p=0.0183) and bm2 (CD19+IgD+CD38+) (p=0.0490) whereas memory B cell subsets such as early bm5 (CD19+IgD-CD38+) and late bm5 (CD19+IgD-CD38-) were significantly reduced (p=0.0249, and p=0.0117 respectively), similar to the profile seen in patients with adult-SS. Interestingly, in the CD4+ T cell compartment, central memory (CD4+CD27+CD45RA-) T cells were significantly reduced (p=<0,0001) but effector memory (CD4+CD27-CD45-) and effector memory-re-expressing-CD45RA (EMRA, CD4+CD27-CD45RA+) T-cell subsets were significantly elevated (p=0.0171 and p=0.0002 respectively). These changes were not identified in adult-SS patients. Finally, unlike our observations in patients with adult-onset SS there was no widespread deregulation of CD8+ T cell subsets in JSS patients; only a significant increase in CD8+CD25-CD127+ responders T cells (p=0.0392) was observed in JSS patients versus healthy.

Conclusion

This is the first pilot study investigating the immunophenotype profile of patients with JSS. Our preliminary findings suggest altered immune phenotypes in both B-cell and T cell compartments and for B cells are in concordance with previous immunophenotyping studies in adult SS (predominance of naïve and lower frequencies of memory B cells), suggesting an immunological rationale for the use of similar therapies. Further studies, comparing the adult with the juvenile phenotype could help stratify patients for targetted therapies and improve treatment in this rare disease in children for which no evidence-based recommnedations exist.

References

[1]Ciurtin C et al. Barriers to translational research in Sjögren’s syndrome with childhood onset: challenges of recognising and diagnosing an orphan rheumatic disease. Lancet Rheumatology. 2021; https://doi.org/10.1016/S2665-9913(20)30393-3.

[2]Martin-Gutierrez L, Peng J, et al. Stratification of Patients with Sjogren’s Syndrome and Patients With Systemic Lupus Erythematosus According to Two Shared Immune Cell Signatures, With Potential Therapeutic Implications. Arthritis Rheumatol. 2021;73(9):1626-37.

Disclosure of Interests

None declared.