A single-cell chromatin accessibility dataset of human primed and naïve pluripotent stem cell-derived teratoma.

Teratoma, due to its remarkable ability to differentiate into multiple cell lineages, is a valuable model for studying human embryonic development. The similarity of the gene expression and chromatin accessibility patterns in these cells to those observed in vivo further underscores its potential as a research tool. Notably, teratomas derived from human naïve (pre-implantation epiblast-like) pluripotent stem cells (PSCs) have larger embryonic cell diversity and contain extraembryonic lineages, making them more suitable to study developmental processes. However, the cell type-specific epigenetic profiles of naïve PSC teratomas have not been yet characterized. Using single-cell assay for transposase-accessible chromatin sequencing (scATAC-seq), we analyzed 66,384 cell profiles from five teratomas derived from human naïve PSCs and their post-implantation epiblast-like (primed) counterparts. We observed 17 distinct cell types from both embryonic and extraembryonic lineages, resembling the corresponding cell types in human fetal tissues. Additionally, we identified key transcription factors specific to different cell types. Our dataset provides a resource for investigating gene regulatory programs in a relevant model of human embryonic development.

Biosynthesis of fungus-based oral selenium microcarriers for radioprotection and immuno-homeostasis shaping against radiation-induced heart disease.

Radiation-induced heart disease (RIHD), characterized by severe oxidative stress and immune dysregulation, is a serious condition affecting cancer patients undergoing thoracic radiation. Unfortunately, clinical interventions for RIHD are lacking. Selenium (Se) is a trace element with excellent antioxidant and immune-modulatory properties. However, its application in heart radioprotection remains challenging. Herein, we developed a novel bioactive Cordyceps militaris-based Se oral delivery system (Se@CM), which demonstrated superior radioprotection effects in vitro against X-ray-induced damage in H9C2 cells through suppressing excessive ROS generation, compared to the radioprotectant Amifostine. Moreover, Se@CM exhibited exceptional cardioprotective effects in vivo against X-ray irradiation, reducing cardiac dysfunction and myocardial fibrosis by balancing the redox equilibrium and modulating the expression of Mn-SOD and MDA. Additionally, Se@CM maintained immuno-homeostasis, as evidenced by the upregulated population of T cells and M2 macrophages through modulation of selenoprotein expression after irradiation. Together, these results highlight the remarkable antioxidant and immunity modulation properties of Se@CM and shed light on its promising application for cardiac protection against IR-induced disease. This research provides valuable insights into developing effective strategies for preventing and managing RIHD.

Atrial lead perforation early after device implantation-a case report and literature review.

We report three patients with screw-in lead perforation in the right atrial free wall not long after device implantation. All the patients complained of intermittent stabbing chest pain associated with deep breathing during the implantation. The "dry" epicardial puncture was utilized to avoid hemopericardium during lead extraction in the first case. The atrial electrode was repositioned in all cases and replaced by a new passive fixation lead in two patients with resolution of the pneumothorax or pericardial effusion. A literature review of 50 reported cases of atrial lead perforation was added to the findings in our case report.

Significance of Volatile Organic Compounds to Secondary Pollution Formation and Health Risks Observed during a Summer Campaign in an Industrial Urban Area.

The chemical complexity and toxicity of volatile organic compounds (VOCs) are primarily encountered through intensive anthropogenic emissions in suburban areas. Here, pollution characteristics, impacts on secondary pollution formation, and health risks were investigated through continuous in-field measurements from 1-30 June 2020 in suburban Nanjing, adjacent to national petrochemical industrial parks in China. On average, the total VOCs concentration was 34.47 ± 16.08 ppb, which was comprised mostly by alkanes (41.8%) and halogenated hydrocarbons (29.4%). In contrast, aromatics (17.4%) dominated the ozone formation potential (OFP) and secondary organic aerosol formation potential (SOAFP) with 59.6% and 58.3%, respectively. Approximately 63.5% of VOCs were emitted from the petrochemical industry and from solvent usage based on source apportionment results, followed by biogenic emissions of 22.3% and vehicle emissions of 14.2%. Of the observed 46 VOC species, hexachlorobutadiene, dibromoethane, butadiene, tetrachloroethane, and vinyl chloride contributed as high as 98.8% of total carcinogenic risk, a large fraction of which was ascribed to the high-level emissions during ozone pollution episodes and nighttime. Therefore, the mitigation of VOC emissions from petrochemical industries would be an effective way to reduce secondary pollution and potential health risks in conurbation areas.

Natural antioxidants mitigate heavy metal induced reproductive toxicity: prospective mechanisms and biomarkers.

Heavy metals are harmful environmental pollutants that have attracted widespread attention, attributed to their health hazards to humans and animals. Due to the non-degradable property of heavy metals, organisms are inevitably exposed to heavy metals such as arsenic (As), cadmium (Cd), lead (Pb), and mercury (Hg). Several studies revealed that heavy metals can cause reproductive damage by the excessive production of reactive oxygen species (ROS), which exacerbates oxidative stress, inflammation, and endocrine disruption. Natural antioxidants, mainly polyphenols, carotenoids, and vitamins, have been shown to mitigate heavy metal-induced reproductive toxicity potentially. In this review, accumulated evidences on the influences of four non-essential heavy metals As, Cd, Pb, and Hg on both males and females reproductive system were established. The purpose of this review is to explore the potential mechanisms of the effects of heavy metals on reproductive function and point out the potential biomarkers of natural antioxidants interventions toward heavy metal-induced reproductive toxicity. Notably, increasing evidence proven that the regulations of hypothalamic-pituitary-gonadal axis, Nrf2, MAPK, or NF-κB pathways are the important mechanisms for the amelioration of heavy metal induced reproductive toxicity by natural antioxidants. It also provided a promising guidance for prevention and management of heavy metal-induced reproductive toxicity.

Chemical Characteristics and Source-Specific Health Risks of the Volatile Organic Compounds in Urban Nanjing, China.

This work comprehensively investigated the constituents, sources, and associated health risks of ambient volatile organic compounds (VOCs) sampled during the autumn of 2020 in urban Nanjing, a megacity in the densely populated Yangtze River Delta region in China. The total VOC (TVOC, sum of 108 species) concentration was determined to be 29.04 ± 14.89 ppb, and it was consisted of alkanes (36.9%), oxygenated VOCs (19.9%), halogens (19.1%), aromatics (9.9%), alkenes (8.9%), alkynes (4.9%), and others (0.4%). The mean TVOC/NOx (ppbC/ppbv) ratio was only 3.32, indicating the ozone control is overall VOC-limited. In terms of the ozone formation potential (OFP), however, the largest contributor became aromatics (41.9%), followed by alkenes (27.6%), and alkanes (16.9%); aromatics were also the dominant species in secondary organic aerosol (SOA) formation, indicative of the critical importance of aromatics reduction to the coordinated control of ozone and fine particulate matter (PM2.5). Mass ratios of ethylbenzene/xylene (E/X), isopentane/n--pentane (I/N), and toluene/benzene (T/B) ratios all pointed to the significant influence of traffic on VOCs. Positive matrix factorization (PMF) revealed five sources showing that traffic was the largest contributor (29.2%), particularly in the morning. A biogenic source, however, became the most important source in the afternoon (31.3%). The calculated noncarcinogenic risk (NCR) and lifetime carcinogenic risk (LCR) of the VOCs were low, but four species, acrolein, benzene, 1,2-dichloroethane, and 1,2-dibromoethane, were found to possess risks exceeding the thresholds. Furthermore, we conducted a multilinear regression to apportion the health risks to the PMF-resolved sources. Results show that the biogenic source instead of traffic became the most prominent contributor to the TVOC NCR and its contribution in the afternoon even outpaced the sum of all other sources. In summary, our analysis reveals the priority of controls of aromatics and traffic/industrial emissions to the efficient coreduction of O3 and PM2.5; our analysis also underscores that biogenic emissions should be paid special attention if considering the direct health risks of VOCs.

Higher serum tissue inhibitor of metalloproteinase-1 predicts atrial fibrillation recurrence after radiofrequency catheter ablation.

Background: Tissue inhibitor of metalloproteinase-1 (TIMP-1) levels is strongly associated with cardiac extracellular matrix accumulation and atrial fibrosis. Whether serum levels of TIMP-1 are associated with atrial fibrillation (AF) recurrence following radiofrequency catheter ablation (RFCA) remains unknown. Materials and methods: Serum TIMP-1 levels of patients with AF before they underwent initial RFCA were measured using ELISA. Univariate and multivariate-adjusted Cox models were constructed to determine the relationship between TIMP-1 levels and AF recurrence. Multivariate logistic regression analyses were performed to determine predictors of AF recurrence. Results: Of the 194 enrolled patients, 61 (31.4%) had AF recurrence within the median 30.0 months (interquartile range: 16.5-33.7 months) of follow-up. These patients had significantly higher baseline TIMP-1 levels than those without AF recurrence (129.8 ± 65.7 vs. 112.0 ± 51.0 ng/ml, P = 0.041). The same was true of high-sensitivity C-reactive protein (3.9 ± 6.0 vs. 1.9 ± 2.8 ng/ml, P = 0.001). When a TIMP-1 cutoff of 124.15 ng/ml was set, patients with TIMP-1 ≥ 124.15 ng/ml had a higher risk of recurrent AF than those with TIMP-1 < 124.15 ng/ml (HR, 1.961, 95% CI, 1.182-2. 253, P = 0.009). Multivariate Cox regression analysis revealed that high TIMP-1 was an independent risk factor for AF recurrence. Univariate Cox regression analysis found that substrate modification surgery does not affect AF recurrence (P = 0.553). Subgroup analysis revealed that female sex, age < 65 years, hypertension (HTN), body mass index (BMI) ≥ 24 kg/m2, CHA2DS2-VASc score < 2, HAS-BLED score < 3, and EHRA score = 3 combined with high TIMP-1 level would perform well at predicting AF recurrence after RFCA. Conclusion: Elevated preoperative TIMP-1 levels are related to a higher risk of AF recurrence and can independently predict AF recurrence following RFCA.

Clinical and Laboratory Biomarkers in Paroxysmal Atrial Fibrillation: A Single Center Cross-Sectional Study.

The clinical risk profile of paroxysmal atrial fibrillation (pAF) patients is inconclusive. We aimed to identify clinical and laboratory biomarkers in patients with pAF and the differences in biomarkers among genders. A cross-sectional study was conducted with a total of 181 participants in a single center in Beijing Anzhen Hospital. The participants were grouped according to the presence of pAF and sex differences, and clinical and laboratory results were collected and compared. The 181 participants had a mean age of 52.9 ± 15.1 years (pAF group, 60.4 ± 9.9 years, SR group, 48.3 ± 15.9 years, P < 0.05). Patients with pAF had significantly higher rates of age, left atrial (LA) diameter, haemoglobin (Hb) levels, tissue inhibitor of metalloproteinase-1 (TIMP-1), soluble tumour suppressor-2 (sST2), B-type natriuretic peptide (BNP) and indirect bilirubin (Ibil), mean haemoglobin concentration (MCHC), and hypertension (HTN) and smoking (P < 0.05). Multivariable logistic regression analysis revealed that age (OR = 1.075, 95% CI: 1.035-1.118, P < 0.0001), smoking (OR = 4.538, 95% CI: 1.559-13.205, P = 0.006), and MCHC (OR = 1.062, 95% CI: 1.019-1.106, P = 0.004) were independent predictive factors for pAF. Multivariable logistic regression analysis found that age (OR = 1.107, 95% CI: 1.016-1.206, P = 0.02) and Ibil level (OR = 2.303, 95% CI: 1.158-4.582, P = 0.017) were independent predictive factors of the occurrence of pAF in females; BNP (OR = 1.015, 95% CI: 1.002-1.029, P = 0.029) was an independent predictive variable of pAF in males. Age, smoking, and MCHC were independent predictive factors of pAF. BNP was an independent predictive biomarker of pAF in males, while in females, age and Ibil were independent predictive factors.

Early assessment of chemotherapeutic response in hepatocellular carcinoma based on serum surface-enhanced Raman spectroscopy.

In clinical practice, the transcatheter arterial chemoembolization (TACE) has been widely accepted as the first option for non-surgical hepatocellular carcinoma (HCC) treatment. However, patients with HCC often suffer from poor response to TACE therapy. This can be prevented if the chemotherapeutic response can be early and accurately assessed, which is essential to guide timely and rational management. In this study, the serum SERS technique was for the first time investigated as a potential prognostic tool for early assessment of HCC chemotherapeutic response. According to the SERS spectral analysis results, it is newly found that not only the absolute circulating nucleic acids and collagen levels in pre-therapeutic serum but also the changes in circulating nucleic acids and amino acids between pre-therapeutic and post-therapeutic serum are expected to be potential serum markers for HCC prognosis. By further applying chemometrics methods to establish prognostic models, excellent prognostic accuracies were achieved within only 3 days after TACE therapy. Thus, the proposed method is expected to provide guidance on timely and rational management of HCC to improve its survival rate.

Exploring the photocatalytic conversion mechanism of gaseous formaldehyde degradation on TiO2-x-OV surface.

To understand the conversion mechanism of photocatalytic gaseous formaldehyde (HCHO) degradation, strontium (Sr)-doped TiO2-x-OV catalysts was designed and synthesized in this study, with comparable HCHO removal performance. Our results proved that foreign-element doping reduced Ti4+ to the lower oxidation state Ti(4- x)+, and that the internal charge kinetics was largely facilitated by the unbalanced electron distribution. Oxygen vacancies (OVs) were developed spontaneously to realize an electron-localized phenomenon in TiO2-x-OV, thereby boosting O2 adsorption and activation for the enhanced generation of reactive oxygen species (ROS). At the chemisorption stage, in-situ DRIFTS spectra and density functional theory calculation results revealed that surface adsorbed O2 (Oads) and lattice O (Olat) engaged in the isomerisation of HCHO to dioxymethylene (DOM) on TiO2-x-OV and TiO2, respectively. Time-resolved DRIFTS spectra under light irradiation revealed that the DOM was then converted to formate and thoroughly oxidized to CO2 and H2O in TiO2-x-OV. While bicarbonate byproducts were detected from DOM hydroxylation or possible side conversion of CO2 in TiO2, owing to insufficient consumption of surface hydroxyl. Our study enhances the understanding on the photocatalytic oxidation of HCHO, thereby promoting the practical application in indoor air purification.

Exogenous melatonin alleviates hemorrhagic shock­induced hepatic ischemic injury in rats by inhibiting the NF­κB/IκBα signaling pathway.

Melatonin (MT) is an indoleamine hormone that can counteract ischemia­induced organ injury through its antioxidant effects. The aim of the present study was to investigate the protective effects of exogenous MT against hemorrhagic shock (HS)­induced hepatic ischemic injury in rats, and the role of the nuclear factor (NF)­κB signaling pathway in this process. A rat model of HS­induced hepatic ischemic injury was established. The serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), glutamate dehydrogenase (GDH), tumor necrosis factor (TNF)­α, interferon (IFN)­Î³, interleukin (IL)­6 and IL­1ß were measured every 6 h, and the 24­h survival rate of the rats was analyzed. All surviving rats were sacrificed after 24 h. Pathological changes in the liver and the hepatocyte apoptosis rate were observed by hematoxylin and eosin staining and TUNEL assay, respectively, and the expression levels of NF­κB p65 and NF­κB inhibitor α (IκBα) were analyzed by reverse transcription­quantitative PCR analysis and western blotting. The results demonstrated that the serum levels of ALT, AST, LDH, GDH, TNF­α, IFN­Î³, IL­6 and IL­1ß gradually increased after HS compared with those in rats subjected to a sham procedure, but this increase was attenuated by MT. Furthermore, the survival rate of the MT group was significantly higher compared with that of the HS group. The degree of pathological hepatic injury, the hepatocyte apoptosis rate, and the hepatic levels of TNF­α, IFN­Î³, IL­6 and IL­1ß were significantly decreased in the MT group compared with the HS group. In addition, the mRNA expression of NF­κB p65 was significantly decreased and the mRNA expression of IκBα was significantly increased in the MT group compared with the sham group. Furthermore, the NF­κB p65 protein levels in the MT group were significantly increased in the cytosol but decreased in the nucleus, and the IκBα protein levels were increased while those of phosphorylated IκBα were decreased compared with those in the HS group. Therefore, it may be inferred that exogenous MT alleviates HS­induced hepatic ischemic injury in rats via the inhibition of NF­κB activation and IκBα phosphorylation.

Chronic oral exposure to cadmium causes liver inflammation by NLRP3 inflammasome activation in pubertal mice.

Cadmium (Cd) is a potentially toxic trace element frequently existed in foods, water, and air, threatening liver function from its continuous bioaccumulation and induction of oxidative stress and inflammation. However, the hepatotoxicity of Cd during puberty remains unclear. In this study, pubertal mice were given cadmium chloride at a dose of 5.0 mg/kg·bw by gavage, and the liver damage was investigated at different treatment points of 10, 20, and 30 days. After Cd exposure, there is an obvious inflammatory hepatocyte infiltration accompanied by more apoptotic cells at 20 days and an increase in alanine aminotransferases and aspartate aminotransferases in circulation at 30 days. Additionally, the soaring TNF-α and MCP-1 were found in liver, and the mRNA expression of pro-inflammatory cytokines (IL-1α, IL-1ß, and IL-18) and anti-inflammatory cytokines (TGF-ß, IL-10, and IL-13) were both significantly upregulated. Moreover, the activated M1 and M2 macrophages were confirmed in charge of these cytokines release. Most importantly, the data validated a pivotal role of NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome in Cd-induced inflammation in liver at puberty. Collectively, our results suggested that low-dose Cd oral exposure can cause liver inflammation via activation of NLRP3 inflammasome and give rise to severe liver injury at puberty.

Triterpenoid-Mediated Inhibition of Virus-Host Interaction: Is Now the Time for Discovering Viral Entry/Release Inhibitors from Nature?

Fatal infectious diseases caused by HIV-1, influenza A virus, Ebola virus, and currently pandemic coronavirus highlight the great need for the discovery of antiviral agents in mechanisms different from current viral replication-targeted approaches. Given the critical role of virus-host interactions in the viral life cycle, the development of entry or shedding inhibitors may expand the current repertoire of antiviral agents; the combination of antireplication inhibitors and entry or shedding inhibitors would create a multifaceted drug cocktail with a tandem antiviral mechanism. Therefore, we provide critical information about triterpenoids as potential antiviral agents targeting entry and release, focusing specifically on the emerging aspect of triterpenoid-mediated inhibition of a variety of virus-host membrane fusion mechanisms via a trimer-of-hairpin motif. These properties of triterpenoids supply their host an evolutionary advantage for chemical defense and may protect against an increasingly diverse array of viruses infecting mammals, providing a direction for antiviral drug discovery.

Effects of indoor activities and outdoor penetration on PM2.5 and associated organic/elemental carbon at residential homes in four Chinese cities during winter.

There is increasing public attention on exposure to PM2.5 and its related health impacts. It is essential to study the pollution levels, sources, and health implications of indoor PM2.5, especially for residential homes, as people tend to spend most of their time indoors. The indoor PM2.5 mass and organic/elemental carbon (OC/EC) during winter and early spring period of 2016-2017 at 68 residential households in four large Chinese cities (i.e. Hong Kong, Guangzhou, Shanghai, and Xi'an) were studied. Average indoor PM2.5 varied by two-fold, lowest in Hong Kong (34.0 ± 14.6 µg m-3) and highest in Xi'an (78.7 ± 49.3 µg m-3), with comparable levels for Guangzhou (47.2 ± 5.4 µg m-3) and Shanghai (50.3 ± 17.9 µg m-3). Lowest air exchange rate (AER, 0.8 ± 0.8 h-1) and PM2.5 indoor/outdoor (I/O) ratio (0.72 ± 0.23) were found for Xi'an households, indicating the limited influence from indoor sources, while importance of indoor PM2.5 sources is signified with the highest PM2.5 I/O ratio (1.32 ± 0.43) identified for Shanghai households. For households in four cities, OC and EC accounted for 29.5%-38.5% and 7.5%-8.9% of the indoor PM2.5 mass, indicating the significance of carbonaceous aerosols. Larger differences between indoor and outdoor OC (2.6-8.4%) than EC (-2.2-1.5%) indicate the presence of indoor OC sources. Decreasing trends of PM2.5 I/O ratio and indoor OC proportion were found as the worsening ambient air quality. On average, 11.8 µg m-3 (23.1%) and 3.02 µg m-3 (18.7%) higher indoor PM2.5 and OC concentrations were identified for households with other indoor combustions (e.g., tobacco smoking, incense burning) compared to those with only cooking activities. For Hong Kong and Shanghai households, increments of 13.2 µg m-3 (54.1%) of PM2.5 and 4.1 µg m-3 (45.4%) of OC were found at households with cooking activities as compared to households with no specific indoor combustion.

Active Complexes on Engineered Crystal Facets of MnOx-CeO2 and Scale-Up Demonstration on an Air Cleaner for Indoor Formaldehyde Removal.

Crystal facet-dominated surfaces determine the formation of surface-active complexes, and engineering specific facets is desirable for improving the catalytic activity of routine transition-metal oxides that often deactivate at low temperatures. Herein, MnOx-CeO2 was synthetically administered to tailor the exposure of three major facets, and their distinct surface-active complexes concerning the formation and quantitative effects of oxygen vacancies, catalytically active zones, and active-site behaviors were unraveled. Compared with two other low-index facets {110} and {001}, MnOx-CeO2 with exposed {111} facet showed higher activity for formaldehyde oxidation and CO2 selectivity. However, the {110} facet did not increase activity despite generating additional oxygen vacancies. Oxygen vacancies were highly stable on the {111} facet, and its bulk lattice oxygen at high migration rates could replenish the consumption of surface lattice oxygen, which was associated with activity and stability. High catalytically active regions were exposed at the {111}-dominated surfaces, wherein the predominated Lewis acid-base properties facilitated oxygen mobility and activation. The mineralization pathways of formaldehyde were examined by a combination of in situ X-ray photoemission spectroscopy and diffuse reflectance infrared Fourier transform spectrometry. The MnOx-CeO2-111 catalysts were subsequently scaled up to work as filter substrates in a household air cleaner. In in-field pilot tests, 8 h of exposure to an average concentration of formaldehyde after start-up of the air cleaner attained the Excellent Class of Indoor Air Quality Objectives in Hong Kong.

In Situ Intermediates Determination and Cytotoxicological Assessment in Catalytic Oxidation of Formaldehyde: Implications for Catalyst Design and Selectivity Enhancement under Ambient Conditions.

Formation and decay of formaldehyde oxides (CH2OO) affect the complete oxidation of formaldehyde. However, the speciation and reactivity of CH2OO are poorly understood because of its extremely fast kinetics and indirect measurements. Herein, three isomers of CH2OO (i.e., main formic acid, small dioxirane, and minor CH2OO Criegee) were in situ determined and confirmed as primary intermediates of the room-temperature catalytic oxidation of formaldehyde with two reference catalysts, that is, TiO2/MnO x-CeO2 and Pt/MnO x-CeO2. CH2OO Criegee is quite reactive, whereas formic acid and dioxirane have longer lifetimes. The production, stabilization, and removal of the three intermediates are preferentially performed at high humidity, matching well with the decay rate of CH2OO at approximately 6.6 × 103 s-1 in humid feed gas faster than 4.0 × 103 s-1 in dry feed. By contrast, given that a thinner water/TiO2 interface was well-defined in TiO2/MnO x-CeO2, fewer reductions in the active sites and catalytic activity were found when humidity was decreased. Furthermore, lethal intermediates mostly captured at the TiO2/MnO x-CeO2 surface suppressed the toxic off-gas emissions. This study provides practical insights into the rational design and selectivity enhancement of a reliable catalytic process for indoor air purification under unfavorable ambient conditions.

Synthesis, structure activity relationship and in vitro anti-influenza virus activity of novel polyphenol-pentacyclic triterpene conjugates.

It is urgently necessary to develop more effective anti-influenza agents due to the continuous emergence of drug-resistant strains of influenza virus. Our earlier studies have identified that certain pentacyclic triterpene derivatives are effective inhibitors of influenza virus infection. In the present study, a series of C-28 modified pentacyclic triterpene derivatives via conjugation with a series of polyphenols were synthesized, and their antiviral activities against influenza A/WSN/33 (H1N1) virus in MDCK (Madin-Darby canine kidney) cells were evaluated. Four compounds 23m, 23o, 23q and 23s displayed robust anti-influenza potency with averaged IC50 values at the low-micromole level, surpassing the potency of oseltamivir. In addition, the in vitro cytotoxic activity of the four conjugates against MDCK cells showed no toxicity at 100 µM. Further mechanism studies of compound 23s, one of the best representative conjugates with IC50 value of 5.80 µM and a selective index (SI) value of over 17.2, by hemagglutination inhibition (HI), surface plasmon resonance and molecular modeling indicated that this conjugate bound tightly to the viral envelope hemagglutinin (KD = 15.6 µM), thus blocking the invasion of influenza viruses into host cells.

Triterpenoids manipulate a broad range of virus-host fusion via wrapping the HR2 domain prevalent in viral envelopes.

A trimer-of-hairpins motif has been identified in triggering virus-cell fusion within a variety of viral envelopes. Chemically manipulating such a motif represents current repertoire of viral fusion inhibitors. Here, we report that triterpenoids, a class of natural products, antagonize this trimer-of-hairpins via its constitutive heptad repeat-2 (HR2), a prevalent α-helical coil in class I viral fusion proteins. Triterpenoids inhibit the entry of Ebola, Marburg, HIV, and influenza A viruses with distinct structure-activity relationships. Specifically, triterpenoid probes capture the viral envelope via photocrosslinking HR2. Profiling the Ebola HR2-triterpenoid interactions using amino acid substitution, surface plasmon resonance, and nuclear magnetic resonance revealed six residues accessible to triterpenoids, leading to wrapping of the hydrophobic helix and blocking of the HR1-HR2 interaction critical in the trimer-of-hairpins formation. This finding was also observed in the envelopes of HIV and influenza A viruses and might potentially extend to a broader variety of viruses, providing a mechanistic insight into triterpenoid-mediated modulation of viral fusion.

An Iron-Containing Metal-Organic Framework as a Highly Efficient Catalyst for Ozone Decomposition.

We present an iron-containing metal-organic framework, MIL-100(Fe), for ozone removal. MIL-100(Fe) exhibits long-lasting ozone conversion efficiency of 100 % for over 100 h under a relative humidity of 45 % and space velocity of 1.9×105  h-1 at room temperature, which is well beyond the performance of most porous or metal catalysts such as activated carbon and α-MnO2 . We also investigated the impact of humidity level and elucidated the plausible reaction mechanism, which is further confirmed by DFT calculations. Furthermore, MIL-100(Fe) can be processed into films and used as filtration layer in a mask to protect personnel against ozone contamination. This study demonstrates the promising potential of MOFs in ozone pollution control, and also offers new insights for the design of ozone decomposition catalysts.

Stable Aluminum Metal-Organic Frameworks (Al-MOFs) for Balanced CO2 and Water Selectivity.

Three new Al-MOFs in the formation of [Al4(OH)2(OCH3)4(OH-BDC)3]·xH2O (BIT-72), [Al4(OH)2(OCH3)4(CH3-BDC)3]·xH2O (BIT-73) and {Al4(OH)2(OCH3)4[(CH3)2-BDC]3}·xH2O (BIT-74) have been synthesized by assembling Al3+ ion with terephthalic acid ions decorated with monohydroxyl, monomethyl or dimethyl groups, respectively. All of these three MOFs exhibit high stability in boiling water and acidic conditions. Among them, BIT-72 shows the highest surface area of 1618 m2·g-1 and IAST CO2/N2 selectivity of 48, while BIT-73 and BIT-74 present moderate IAST CO2/N2 selectivity and much lower H2O capacity below P/P0 = 0.3. The high CO2/N2 selectivity together with alleviative H2O sorption at low water relative pressure may provide promising potential in postcombustion CO2 capture.