A Bioprinted Heart-on-a-Chip with Human Pluripotent Stem Cell-Derived Cardiomyocytes for Drug Evaluation

In this work, we show that valve-based bioprinting induces no measurable detrimental effects on human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). The aim of the current study was three-fold: first, to assess the response of hiPSC-CMs to several hydrogel formulations by measuring electrophysiological function; second, to customise a new microvalve-based cell printing mechanism in order to deliver hiPSC-CMs suspensions, and third, to compare the traditional manual pipetting cell-culture method and cardiomyocytes dispensed with the bioprinter. To achieve the first and third objectives, iCell² (Cellular Dynamics International) hiPSC-CMs were used. The effects of well-known drugs were tested on iCell² cultured by manual pipetting and bioprinting. Despite the results showing that hydrogels and their cross-linkers significantly reduced the electrophysiological performance of the cells compared with those cultured on fibronectin, the bio-ink droplets containing a liquid suspension of live cardiomyocytes proved to be an alternative to standard manual handling and could reduce the number of cells required for drug testing, with no significant differences in drug-sensitivity between both approaches. These results provide a basis for the development of a novel bioprinter with nanolitre resolution to decrease the required number of cells and to automate the cell plating process.

Personalized individual-based exercise prescriptions are effective in treating depressive symptoms of college students during the COVID-19: A randomized controlled trial in China

BACKGROUND

The COVID-19 pandemic has seriously increased depression prevalence among the public, including Chinese college students. However, many exercise cannot be performed as usual under the stay-at-home order. This study was a 12-week three-arm randomized controlled trial using the intention-to-treat principle, aiming to explore and compare the feasibility and effect of individual-based personalized aerobic-exercise and resistance-training prescriptions on depressive symptoms in college students, and conclude with some recommendations for individual-based exercise prescriptions.

METHODS

Eighty-six college students with depressive symptoms were randomized into aerobic-exercise (AE), resistance-training (RT), and wait-list control (WLC) groups. Participants in two experimental groups received 12-week personalized AE and RT prescriptions on their individual situations, respectively. No intervention was implemented on participants in the WLC group. Depressive symptoms and physical activity (PA) were measured by Zung Self-Rating Depression Scale (SDS) and International Physical Activity Questionnaire-Short Form (IPAQ-SF), respectively. All data were collected at the baseline, 4, 8, and 12 weeks, and 4-week post-intervention.

RESULTS

At 12 weeks, 72.09% of depressive participants improved to "normal." Participants exhibited a statistical reduction in SDS in all 3 groups (p < 0.05) at 12 weeks compared to baseline. Follow-up assessments showed no significant increase in SDS at 4-week post-intervention compared to 12 weeks (p > 0.05). The independent t-test revealed significantly lower SDS in AE and RT group than in WLC group (p _AE < 0.001 and p _RT < 0.05) at 4, 8, and 12 weeks, and 4-week post-intervention. Furthermore, the PA of participants (including total PA and intensities) in both experimental groups represented a significant improvement at 4-week post-intervention compared to baseline (p < 0.05), while no differences were observed in the PA of participants in the WLC group (p > 0.05).

CONCLUSION

Personalized exercise prescriptions have good feasibility as they can increase adherence to intervention and reduce serious adverse events. Besides, individual-based personalized aerobic-exercise and resistance-training prescriptions result in a similar effect in relieving depressive symptoms and improving physical activity in college students. The individual-based exercise programs performed in 45- to 60- min with progressive moderate-to-vigorous intensity, 3 times/week for at least 12 weeks, may reduce depressive symptoms in college students during the COVID-19.

Theoretical study of the reaction mechanism between Criegee intermediates and hydroxyl radicals in the presence of ammonia and amine

Criegee intermediates (CIs), formed in the ozonolysis process of unsaturated hydrocarbons, play an important role in the formation of OH radicals, sulfuric acid, and aerosols. In this study, quantum chemical calculations were carried out to investigate the mechanism for the reaction of Criegee intermediates [involving CH₂OO, CH₃CHOO and (CH₃)₂COO] with OH radicals at the level of CCSD(T)/jun-cc-pVTZ//M06-2X/6-311 + G(2d,2p). A third component, such as water, ammonia, or amines, was introduced to the reaction of CIs with OH to evaluate their catalytic effect. The results show that the OH addition is the favorable channel among four channels involving cis-H abstraction, trans-H abstraction and O abstraction. The third component has a positively catalytic effect on the trans-H abstraction and O abstraction pathways. Moreover, for the trans-H abstraction of CH₃CHOO and (CH₃)₂COO with OH, ammonia and amine exhibit more effectively catalytic ability than water. Furthermore, Born-Oppenheimer molecular dynamic simulation results show that the addition of third component to CIs and hydrogen abstraction from the third component by OH occur simultaneously.

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

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

CircHIPK3 contributes to human villous trophoblast growth, migration and invasion via modulating the pathway of miR-346/KCMF1

INTRODUCTION

Preeclampsia (PE) is one of the leading causes of maternal and perinatal morbidity and mortality worldwide. The regular growth, migration and invasion of villous trophoblast cells contribute to placental development. The objective of this study was to investigate the role and mechanism of circular RNA homeodomain interacting protein kinase 3 (circHIPK3) in the biological functions of trophoblast cells.

METHODS

The expression of circHIPK3, microRNA-346 (miR-346) and potassium channel modulatory factor 1 (KCMF1) mRNA was measured by quantitative real-time PCR (qPCR). Trophoblast cell proliferation, migration/invasion and cell cycle progression/apoptosis were determined by CCK-8 assay, transwell assay and flow cytometry assay, respectively. The predicted relationship between miR-346 and circHIPK3 or KCMF1 by bioinformatics was confirmed dual-luciferase reporter assay and RIP assay.

RESULTS

CircHIPK3 and KCMF1 were downregulated, while miR-346 was upregulated in placenta tissues from PE patients. The forced expression of circHIPK3 promoted trophoblast cell proliferation and migration/invasion but alleviated cell cycle arrest and cell apoptosis. MiR-346 was a target of circHIPK3, and miR-346 restoration reversed the effects of circHIPK3 upregulation. In addition, circHIPK3 acted as miR-346 sponge to modulate KCMF1 expression. KCMF1 downregulation partially repressed trophoblast cell proliferation, migration and invasion that were facilitated by miR-346 inhibition or circHIPK3 upregulation.

DISCUSSION

CircHIPK3 contributes to trophoblast cell proliferation, migration and invasion by upregulating KCMF1 via acting as miR-346 sponge.

Factors Influencing the Implementation of Foreign Innovations in Organization and Management of Health Service Delivery in China: A Systematic Review

Background: China has been encouraged to learn from international innovations in the organization and management of health service delivery to achieve the national health reform objectives. However, the success and effectiveness of implementing innovations is affected by the interactions of innovations with the Chinese context. Our aim is to synthesize evidence on factors influencing the implementation of non-Chinese innovations in organization and management of health service delivery in mainland China. Methods: A systematic review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We searched seven databases for peer-reviewed articles published between 2009 and 2020. Data were analyzed and combined to generate a list of factors influencing the implementation of foreign innovations in China. The factors were classified in the categories context, system, organization, innovation, users, resources, and implementation process. Results: The 110 studies meeting the inclusion criteria revealed 33 factors. Most supported by evidence is the factor integration in organizational policies, followed by the factors motivation & incentives and human resources. Some factors (e.g., governmental policies & regulations) were mentioned in multiple studies with little or no evidence. Conclusion: Evidence on factors influencing the implementation of foreign innovations in organization and management of health service delivery is scarce and of limited quality. Although many factors identified in this review have also been reported in reviews primarily considering Western literature, this review suggests that extrinsic motivation, financial incentives, governmental and organizational policies & regulations are more important while decentralization was found to be less important in China compare to Western countries. In addition, introducing innovations in rural China seems more challenging than in urban China, because of a lack of human resources and the more traditional rural culture.

What Do We Know About Teamwork in Chinese Hospitals? A Systematic Review

Background and Objective: Improving quality of care is one of the primary goals in current Chinese hospital reforms. Teamwork can play an essential role. Characteristics of teamwork and interventions for improving teamwork in hospitals have been widely studied. However, most of these studies are from a Western context; evidence from China is scarce. Because of the contextual differences between China and Western countries, empirical evidence on teamwork from Western hospitals may have limited validity in China. This systematic review aims to advance the evidence base and understanding of teamwork in Chinese hospitals. Methods: Both English (i.e., Embase, Medline, and Web of Science) and Chinese databases (i.e., CNKI, CQVIP, and Wanfang) were searched for relevant articles until February 6, 2020. We included the studies that empirically researched teamwork in Chinese hospitals. Studies were excluded if they (1) were not conducted in hospitals in Mainland China, (2) did not research teamwork on team interventions, (3) were not empirical, (4) were not written in English or Chinese, (5) were not published in peer-reviewed journals, and (6) were not conducted in teams that provide direct patient care. Both deductive and inductive approaches were used to analyze data. The Mixed Methods Appraisal Tool (MMAT) was used to assess their methodological quality. Results: A total of 70 articles (i.e., 39 English articles and 31 Chinese articles) were included. The results are presented in two main categories: Teamwork components and Team interventions. The evidence regarding the relationships among inputs, processes, and outcomes is scarce and mostly inconclusive. The only conclusive evidence shows that females perceive better team processes than males. Similar types of training and tools were introduced as can be found in Western literature, all showing positive effects. In line with the Chinese health reforms, many of the intervention studies regard the introduction of multidisciplinary teams (MDTs). The evidence on the implementation of MDTs reveals that they have led to lower complication rates, shorter hospital stays, higher diagnosis accuracy, efficiency improvement, and a variety of better disease-specific clinical outcomes. Evidence on the effect on patient survival is inconclusive. Conclusion: The Chinese studies on teamwork components mainly focus on the input-process relationship. The evidence provided on this relationship is, however, mostly inconclusive. The intervention studies in Chinese hospitals predominantly focus on patient outcomes rather than organizational and employee outcomes. The introduction of training, tools, and MDTs generally shows promising results. The evidence from primary hospitals and rural areas, which are prioritized in the health reforms, is especially scarce. Advancing the evidence base on teamwork, especially in primary hospitals and rural areas, is needed and can inform policy and management to promote the health reform implementation. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020175069, identifier CRD42020175069.

A COVID-19 screening method based on eyes photographs and artificial intelligence

Background

SARS-CoV-2 can spread both from symptomatic and asymptomatic individuals. Ocular manifestations due to SARS-CoV-2 have been described, being conjunctival inflammation the most common affectation. Evidence shows that conjunctivitis could be the first and/or only manifestation of COVID-19. This study aimed to develop and validate a COVID-19 screening method based on eyes photographs and artificial intelligence.

Methods

In this multicentre study, 1,200 participants were enrolled from Shanghai Public Health Clinical Center (SPHCC) Fudan University, AIMOMICS LAB and La Fe University and Polytechnic Hospital (LFUPH) of Valencia (Spain). Pictures of participants' ocular surface were taken in four different positions with mobile phone cameras, and a Deep Learning System (DLS) was developed through machine learning to identify characteristic conjunctival inflammation patterns. The study was conducted in accordance with the Declaration of Helsinki and was approved by the Ethics Committees of SPHCC and LFUPH.

Results

The area under the receiver-operating-characteristic curve (AUC), sensitivity, specificity, and accuracy were calculated according to the results of our binary classification network. Bootstrapping with 1,000 replicates was used to estimate 95% confidence intervals of the performance metrics, with photography as the resampling unit. On the subject-level classification, the network achieved the AUC of 0.976 (95% CI 0.965-0.988) among Asian population and 0.892 (95% CI 0-763-1.000) among Caucasian population.

Conclusions

Preliminary results show that this DLS performed well in identifying probable asymptomatic COVID-19 cases through the analysis of participants' eyes pictures. This method could be an innocuous, accessible, low cost and quick COVID-19 screening method. Eventually, it could potentially contribute to pandemic control.

Key messages

In the context of the COVID-19 pandemic it would be useful to have a screening method to easily and quickly detect asymptomatic individuals, in addition to using temperature control. Preliminary results show that this Deep Learning System (DLS) based on eyes pictures taken with mobile phone cameras could be an innocuous, accessible, low cost and quick COVID-19 screening method.

Gas-phase and aqueous-surface reaction mechanism of Criegee radicals with serine and nucleation of products: A theoretical study

Criegee intermediates (CIs) are short-lived carbonyl oxides, which can affect the budget of OH radicals, ozone, ammonia, organic/inorganic acids in the troposphere. This study investigated the reaction of CIs with serine (Ser) in the gas phase by using density functional theory (DFT) calculations and at the gas-liquid interface by using Born-Oppenheimer molecular dynamics (BOMD). The results reveal that the reactivity of the three functional groups of Ser can be ordered as follows: COOH > NH₂ > OH. Water-mediated reactions of CIs with NH₂ and OH groups of Ser on the droplet follow the proton exchange mechanism. The products, sulfuric acids, ammonia, and water molecules form stable clusters within 20 ns. This study shows that hydroperoxide products can contribute to new particle formation (NPF). The result deepens the understanding of the reaction of CIs with multifunctional pollutants and atmospheric behavior of CIs in polluted areas.

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

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

[Vincristine inhibits the proliferation of ovarian cancer cells by regulating the demethylation of RASSF2A]

Objective: To investigate the effect of vincristine on the proliferation of ovarian cancer cells by regulating RASSF2A demethylation. Methods: SKOV3 cells were infected with control (LV-NC) and RASSF2A lentivirus (LV-RASSF2A) and treated with or without vincristine. Cell counting kit-8 (CCK-8) was used to detect the activity of ovarian cancer cells (SKOV3) treated with different doses of vincristine. Colony formation assay was used to detect the proliferation of SKOV3 cells. Flow cytometry was used to detect the apoptosis of SKOV3 cells. Real time polymerase chain reaction (RT-PCR) was used to examine the mRNA expression of RASSF2A in IOSE-29 and SKOV3 cells. Western blot was used to examine the protein expression of RASSF2A in IOSE-29 and SKOV3 cells. Methylation-specific PCR was used to detect methylation and demethylation levels of RASSF2A gene in IOSE-29 and SKOV3 cells. Results: The cell viabilities of SKOV3 cell treated with 6.25 nmol/L, 12.5 nmol/L, 25 nmol/L, 50 nmol/L and 100 nmol/L vincristine were (87.19±4.49)%, (73.67±8.62)%, (66.35±6.04)%, (50.32±6.00)% and (34.92±6.11)%, respectively, lower than (100.46±4.69)% of control group (P<0.05). The half maximal inhibitory concentration of vincristine at 48 hours was 50.02 nmol/L. The proliferation abilities of SKOV3 cells in vincristine 12.5 nmol/L group, 25 nmol/L group and 50 nmol/L group were (41.70±2.21)%, (32.15±1.80)% and (23.00±2.01)%, respectively, significantly lower than (100.78±5.66)% in the control group (all P<0.05). The apoptotic rates of SKOV3 cells in vincristine 12.5 nmol/L group, 25 nmol/L group and 50 nmol/L group were (3.65±0.27)%, (5.21±0.76)% and (10.46±1.00)%, respectively, significantly higher than (2.12±0.23)% in the control group (all P<0.05). Compared with the IOSE-29 group (1.00±0.07 and 0.68±0.04), the mRNA expression (0.32±0.04) and protein expression (0.24±0.02) of RASSF2A were down-regulated in SKOV3 cells (P<0.05). Compared with the LV-NC group [(101.60±4.39)%, (100.73±3.29)%, (4.06±0.30)%], over-expression of RASSF2A down-requlated cell viability (68.92±3.94)%, inhibited proliferation (16.38±2.16)%, and promoted apoptosis (8.65±0.56)%, (P<0.05). Conclusion: Vincristine can increase RASSF2A expression and inhibit ovarian cancer cell proliferation by promoting the demethylation of RASSF2A promoter.

Heavy ozone pollution episodes in urban Beijing during the early summertime from 2014 to 2017: Implications for control strategy

Ground-level ozone (O₃) has become the principal air pollutant in Beijing during recent summers. In this context, an investigation of ambient concentrations and variation characteristics of O₃ and its precursors in May and June from 2014 to 2017 in a typical urban area of Beijing was carried out, and the formation sensitivity and different causes of heavy O₃ pollution (HOP, daily maximum 8-h O₃ (MDA8h O₃)>124 ppbv) were analyzed. The results showed that the monthly assessment values of the O₃ concentrations (the 90^th percentile MDA8h O₃ within one month) were highest in May or June from 2014 to 2017, and the values presented an overall increasing trend. During this period, the number of O₃ pollution days (MDA8h O₃ > 75 ppbv) also showed an increasing trend. During the HOP episodes, the concentrations of volatile organic compounds (VOCs), nitrogen oxides (NO_X), and carbon monoxide (CO) were higher than their respective mean values in May and June, and the meteorological conditions were more conducive to atmospheric photochemical reactions. The HOP episodes were mainly caused by local photochemical formation. From 2014 to 2017, O₃ formation during the HOP episodes shifted from VOC and NO_X mixed-limited to VOC-limited conditions, and O₃ formation was most sensitive to anthropogenic VOCs. Six categories of VOC sources were identified, among which vehicular exhaust contributed the most to anthropogenic VOCs. The VOC concentrations and OFPs of anthropogenic sources have decreased significantly in recent years, indicating that VOC control measures have been effective in Beijing. Nevertheless, NO_X concentrations did not show an evident decreasing trend in the same period. Therefore, more attention should be devoted to O₃ pollution control in May and June; control measure adjustments are needed according to the changes in O₃ precursors, and coordinated control of VOCs and NO_X should be strengthened in long-term planning.

Comprehensive evaluation of manganese oxides and iron oxides as metal substrate materials for constructed wetlands from the perspective of water quality and greenhouse effect

Manganese oxides and iron oxides have been widely introduced in constructed wetlands (CWs) for sewage treatment due to their extensiveness in nature and their ability to participate in various reactions, but their effects on greenhouse gas (GHG) emissions remain unclear. Here, a set of vertical subsurface-flow CWs (Control, Fe-VSSCWs, and Mn-VSSCWs) was established to comprehensively evaluate which are the better metal substrate materials for CWs, iron oxides or manganese oxides, through water quality and the global warming potential (GWP) of nitrous oxide (N₂O), methane (CH₄), and carbon dioxide (CO₂). The results revealed that the removal efficiencies of chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) in Mn-VSSCWs were all higher than that in Fe-VSSCWs, and manganese oxides could almost completely suppress the CH₄ production and reduce GWP (from 8.15 CO₂-eq/m²/h to 7.17 mg CO₂-eq/m²/h), however, iron oxides promoted GWP (from 8.15 CO₂-eq/m²/h to 10.84 mg CO₂-eq/m²/h), so manganese oxides are the better CW substrate materials to achieve effective sewage treatment while reducing the greenhouse gas effect.

Insights into the metabolic mechanism of PBDEs catalyzed by cytochrome P450 enzyme 3A4: A QM/MM study

Elucidating the metabolic mechanism and the derivatives of polybrominated diphenyl ethers (PBDEs) is significant to risk assessment. This study delineated the metabolic mechanism of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) catalyzed by P450 enzymes using a combination of molecular dynamic (MD), quantum mechanics/molecular mechanics (QM/MM) and density functional theory (DFT). The calculation results reveal that the electrophilic addition is the main pathway for the biotransformation of BDE-47 catalyzed by P450 enzymes. 6-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (6-OH-BDE-47) is a more kinetically preferable product than 5-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (5-OH-BDE-47). Electrophilic addition reaction can lead to the formation of polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs). The ecotoxicity assessment indicates that the final products of BDE-47 are still toxic to aquatic organisms, but the solubility increase of the hydroxylated products can accelerate their excretion from the body. We expect that the established metabolic mechanism and the derivatives will be used to predict the biotransformation of other PBDE congeners catalyzed by P450 enzymes in human livers.

Acetaminophen degradation by hydroxyl and organic radicals in the peracetic acid-based advanced oxidation processes: Theoretical calculation and toxicity assessment

The research on the mechanisms and kinetics of radical oxidation in peracetic acid-based advanced oxidation processes was relatively limited. In this work, HO^• and organic radicals mediated reactions of acetaminophen (ACT) were investigated, and the reactivities of important organic radicals (CH₃COO^• and CH₃COOO^•) were calculated. The results showed that initiated reaction rate constants of ACT are in the order: CH₃COO^• (5.44 × 10¹⁰ M^-1 s^-1) > HO^• (7.07 × 10⁹ M^-1 s^-1) > CH₃O^{• (}1.57 × 10⁷ M^-1 s^-1) > CH₃COOO^• (3.65 × 10⁵ M^-1 s^-1) >> ^•CH₃ (5.17 × 10² M^-1 s^-1) > CH₃C^•O (1.17 × 10² M^-1 s^-1) > CH₃OO^• (11.80 M^-1 s^-1). HO^•, CH₃COO^• and CH₃COOO^• play important roles in ACT degradation. CH₃COO^• is another important radical in the hydroxylation of aromatic compounds in addition to HO^•. Reaction rate constants of CH₃COO^• and aromatic compounds are 1.40 × 10⁶ - 6.25 × 10¹⁰ M^-1 s^-1 with addition as the dominant pathway. CH₃COOO^• has high reactivity to phenolate and aniline only among the studied aromatic compounds, and it was more selective than CH₃COO^•. CH₃COO^•-mediated hydroxylation of aromatic compounds could produce their hydroxylated products with higher toxicity.

Substantial emissions of nitrated aromatic compounds in the particle and gas phases in the waste gases from eight industries

Nitrated aromatic compounds, the ubiquitous nitrogen-containing organic pollutants, impact the environment and organisms adversely. As industrial raw materials and intermediates, nitrated aromatic compounds and their aromatic precursors are widely employed in the industrial production activities. Nevertheless, their emission from industrial waste gases has so far not been studied extensively. In this study, the concentrations of 12 nitrated aromatic compounds in the particle and gas phases downwind of 16 factories encompassing eight industries (i.e., pharmaceutical, weaving and dyeing, herbicide, explosive, painting, phenolic resin, paper pulp and polystyrene foam industries), were determined by ultra-high-performance liquid chromatography-mass spectrometry. Their concentrations in the particle and gas phases from different factories ranged from 114.7 ± 63.5 to 296.6 ± 62.5 ng m^-3 and 148.7 ± 7.4 to 309.8 ± 26.2 ng m^-3, respectively, thus, exhibiting significantly high concentrations as compared to the background sites. Among the 12 detected species, 4-nitrophenol, 5-nitrosalicylic acid, 3-nitrosalicylic acid and 4-methyl-2,6-dinitrophenol were observed to be the predominant species, with total fractions up to 47.9-72.3% and 63.1-70.3% in the particle and gas phases, respectively. Their emission profiles with respect to the industrial activities exhibited large discrepancies as compared to the combustion sources, thus, indicating different formation mechanisms. The emission ratios of particulate nitrated aromatic compounds owing to the industrial activities were estimated between 0.5 ± 0.2 and 4.3 ± 1.5 ng μg^-1, which were higher than or comparable to those from various combustion sources. The findings from this study confirm the industrial emission to be an important source of nitrated aromatic compounds in the atmosphere. The substantial emissions of nitrated aromatic compounds from various industries reported in this study provide the fundamental basis for further emission estimation and pollution control.

Peptide vaccine-conjugated mesoporous carriers synergize with immunogenic cell death and PD-L1 blockade for amplified immunotherapy of metastatic spinal

The clinical treatment of metastatic spinal tumor remains a huge challenge owing to the intrinsic limitations of the existing methods. Programmed cell death protein 1 (PD1)/programmed cell death ligand 1 (PD-L1) pathway blockade has been explored as a promising immunotherapeutic strategy; however, their inhibition has a low response rate, leading to the minimal cytotoxic T cell infiltration. To ameliorate the immunosuppressive microenvironment of intractable tumor and further boost the efficacy of immunotherapy, we report an all-round mesoporous nanocarrier composed of an upconverting nanoparticle core and a large-pore mesoporous silica shell (UCMS) that is simultaneously loaded with photosensitizer molecules, the IDO-derived peptide vaccine AL-9, and PD-L1 inhibitor. The IDO-derived peptide can be recognized by the dendritic cells and presented to CD8⁺ cytotoxic T cells, thereby enhancing the immune response and promoting the killing of the IDO-expressed tumor cells. Meanwhile, the near-infrared (NIR) activated photodynamic therapy (PDT) could induce immunogenic cell death (ICD), which promotes the effector T-cell infiltration. By combining the PDT-elicited ICD, peptide vaccine and immune checkpoint blockade, the designed UCMS@Pep-aPDL1 successfully potentiated local and systemic antitumor immunity and reduced the progression of metastatic foci, demonstrating a synergistic strategy for cancer immunotherapy.

[Early reduction of serum RANTES can predict HBsAg clearance in patients with chronic hepatitis B treated with nucleos(t)ide analogues combined with peginterferon alpha]

Objective: To observe the dynamic changes of serum RANTES during the treatment with nucleos(t)ide analogues combined with pegylated interferon alpha (peginterferon-α), and further analyze the predictive effect of RANTES on HBsAg clearance in patients with chronic hepatitis B. Methods: 98 cases of chronic hepatitis B with quantitative HBsAg < 3 000 IU/ml and HBV DNA < 20 IU/ml after≥1 year NAs treatment were enrolled. Among them, 26 cases continued to receive NAs monotherapy, 72 cases received NAs combined with pegylated interferon alpha therapy. The changes in RANTES during treatment were observed. The receiver operating characteristic curve was used to analyze the early changes of RANTES to predict the HBsAg clearance during 48 weeks. Results: During 48 weeks, 15 cases (20.83%) had achieved HBsAg clearance in combination group, while no patient had achieved HBsAg clearance in NAs group. The overall serum RANTES level had decreased from baseline in NAs and combination group. At week 48, in the combination group, the serum RANTES level was decreased more significantly in patients with HBsAg clearance than patients without. Further analysis showed that, in combination group, HBsAg clearance rate of patients with serum RANTES decreased at week 12 and 24 was higher than patients with elevated (29.17% vs. 4.17%, P = 0.014; 28.00% vs. 4.55%, P = 0.052), and quantitative HBsAg reduction was larger significantly [(1.49 ± 1.26) log(10)IU/ml vs. (0.73 ± 0.81) log(10)IU/ml, P = 0.017; (1.54 ± 1.27) log(10)IU/ml vs. (0.57 ± 0.56) log(10)IU/ml, P = 0.004]. Receiver operating characteristic curve analysis showed that the baseline quantitative HBsAg and the reduction in quantitative HBsAg and serum RANTES during the early period were predictors of HBsAg clearance after 48-week combination therapy. Furthermore, the combination of baseline quantitative HBsAg and 12 - or 24-week reduction of serum RANTES were better predictors of HBsAg clearance than that of baseline quantitative HBsAg combined with HBsAg decrease at week 12 or 24. The area under the receiver operating characteristic curve of the former was 0.925 and 0.939, while that of the latter was 0.909 and 0.929, respectively. Conclusion: Early reduction of serum RANTES at week 12 and 24 can predict HBsAg loss in CHB patients receiving addition of peginterferon-α to ongoing NAs Therapy, so serum RANTES could be one of the key immunological markers for predicting HBsAg clearance.

Electrochemical synthesis of 1,2,4,5-tetrasubstituted imidazoles from enamines and benzylamines

An electrochemical method for synthesizing 1,2,4,5-tetrasubstituted imidazoles was developed under undivided electrolytic conditions. This synthesis was specifically realized based on electrochemical C(sp3)-H amination via enamines and amines. Readily available starting materials were used, avoiding the use of both transition metals and oxidants. The practicability of the method lies in its broad substrate adaptability and in its ability to provide a simple green pathway for synthesizing GABAA receptor analogs.

Enhanced photocatalytic performance of PdO-loaded heterostructured nanobelts to degrade phenol

Heterostructured catalysts play a significant role in the photodegradation of pollutants in wastewater. Combining the large surface of nanobelts with the high photocatalytic property of titanium dioxide (TiO₂) nanoparticles is a promising method for preparing photocatalysts, which have an advanced photocatalytic activity and are easy to precipitate. In this work, titanium dioxide nanobelts (NB) and acid corroded titanium dioxide nanobelts (C-NB) were synthesized via a hydrothermal process under alkaline conditions. Their surfaces were then loaded with palladium oxide (PdO) nanoparticles to prepare heterostructured photocatalysts (PdO-NB and PdO-C-NB) by a well-designed chemical precipitation method. The photodegradation efficiencies of the four catalysts for phenol, as well as for methyl orange, were tested and the order of degradation efficiency was found to be PdO-C-NB > PdO-NB > C-NB > NB. A degradation efficiency of 61% for phenol was achieved within 90 min using PdO-C-NB, which was nearly twice as much as using NB. The enhanced photocatalytic property of PdO-C-NB was due to the large specific surface area, abundant photocatalytic active sites and the low recombination rate of electron-hole pairs. Therefore, the degradation of phenol and methyl orange was speeded up considerably. Considering the high catalytic activity of PdO-C-NB, the heterostructure catalyst is of great significance to the degradation of organic wastewater, and has an important impact on our ecological environment and human health.

Theoretical study of the formation and nucleation mechanism of highly oxygenated multi-functional organic compounds produced by α-pinene

In recent years, highly oxygenated organic molecules (HOMs) derived from photochemical reactions of α-pinene, the most abundant monoterpene, have been considered as important precursors of biogenic particles. However, the specific reactions of HOMs remain largely unknown, especially the corresponding formation and nucleation mechanism in the nanoscale. In this study, we implemented quantum chemical calculations and molecular dynamics (MD) simulations to explore the mechanism of the formation of HOM monomers/dimers by ozonolysis and autoxidation of α-pinene. Furthermore, we investigated the mechanisms of HOMs with different oxygen-to‑carbon (O/C) ratios and functional groups participating in neutral and ion-induced nucleation. The results show that the formation of HOMs is hardly affected by water, sulfuric acid and ions. In the ion-induced nucleation, HOM can dominate the initial nucleation steps; however, in the neutral nucleation, HOMs are more likely to participate in the growth stage. In addition, the nucleation ability of HOM has a bearing on the O/C ratio and the types of the functional groups. The current calculations provide valuable insight into the formation mechanism of the pure organic particles at low sulfuric acid concentrations.

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

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

Imparting multi-functionality to covalent organic framework nanoparticles by the dual-ligand assistant encapsulation strategy

The potential applications of covalent organic frameworks (COFs) can be further developed by encapsulating functional nanoparticles within the frameworks. However, the synthesis of monodispersed core@shell structured COF nanocomposites without agglomeration remains a significant challenge. Herein, we present a versatile dual-ligand assistant strategy for interfacial growth of COFs on the functional nanoparticles with abundant physicochemical properties. Regardless of the composition, geometry or surface properties of the core, the obtained core@shell structured nanocomposites with controllable shell-thickness are very uniform without agglomeration. The derived bowl-shape, yolk@shell, core@satellites@shell nanostructures can also be fabricated delicately. As a promising type of photosensitizer for photodynamic therapy (PDT), the porphyrin-based COFs were grown onto upconversion nanoparticles (UCNPs). With the assistance of the near-infrared (NIR) to visible optical property of UCNPs core and the intrinsic porosity of COF shell, the core@shell nanocomposites can be applied as a nanoplatform for NIR-activated PDT with deep tissue penetration and chemotherapeutic drug delivery.

Comprehensive Understanding of Fluoroacetate Dehalogenase-Catalyzed Degradation of Fluorocarboxylic Acids: A QM/MM Approach

Fluorochemicals are persistent, bioaccumulative, and toxic compounds that are widely tributed in the environment. Developing efficient biodegradation strategies to decompose the fluorochemicals via breaking the inert C-F bonds presents a holistic challenge. As a promising biodegradation enzyme candidate, fluoroacetate dehalogenase (FAcD) has been reported as the only non-metallic enzyme to catalyze the cleavage of the strong C-F bond. Here, we systematically investigated the catalytic actions of FAcD toward its natural substrate fluoroacetate using molecular dynamics simulations and quantum mechanism/molecular mechanism calculations. We propose that the enzymatic transformation involves four elementary steps, (I) C-F bond activation, (II) nucleophilic attack, (III) C-O bond cleavage, and (IV) proton transfer. Our results show that nucleophilic attack is the rate-determining step. However, for difluoroacetate and trifluoroacetate, C-F bond activation, instead of nucleophilic attack, becomes the rate-determining step. We show that FAcD, originally recognized as α-fluorocarboxylic acid degradation enzyme, can catalyze the defluorination of difluoroacetate to glyoxylate, which is captured by our high-resolution mass spectrometry experiments. In addition, we employed amino acid electrostatic analysis method to screen potential mutation hotspots for tuning FAcD's electrostatic environment to favor substrate conversion. The comprehensive understanding of catalytic mechanism will inform a rational enzyme engineering strategy to degrade fluorochemicals for benefits of environmental sustainability.