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High cost and poor durability of Pt-based cathode catalysts for oxygen reduction reaction (ORR) severely hamper the popularization of proton exchange membrane fuel cells (PEMFCs). Tailoring carbon support is one of effective strategies for improving the performance of Pt-based catalysts. Herein, petroleum vacuum residue was used as carbon source, and nitrogen-doped porous carbon (N-PPC) was synthesized using a simple template-assisted and secondary calcination method. Small Pt nanoparticles (Pt NPs) with an average particles size of 1.8 nm were in-situ prepared and spread evenly on the N-PPC. Interestingly, the lattice compression (1.08%) of Pt NPs on the N-PPC (Pt/N-PPC) was clearly observed by aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), which was also verified by the shift of (111) crystal plane of Pt on N-PPC to higher angles. The X-ray photoelectron spectroscopy (XPS) results suggest that the N-PPC support had a strong effect on anchoring Pt NPs and endowing surface Pt NPs with lowered d band center. Thus, the Pt/N-PPC as a catalyst simultaneously boosted the ORR activity and durability. The specific activity (SA) and mass activity (MA) of the Pt/N-PPC at 0.9 V reached 0.83 mA cm−2 and 0.37 A mg Pt −1, respectively, much higher than those of the commercial Pt/C (0.21 mA cm−2 and 0.11 A mg Pt −1) in 0.1 M HClO 4. The half-wave potential (E 1/2) of Pt/N-PPC exhibited only a minimal negative shift of 7 mV after 30,000 accelerated durability tests (ADT) cycles. More importantly, an H 2 –O 2 fuel cell with a Pt/N-PPC cathode achieved a power density of 866 mW cm−2, demonstrating that the prepared catalyst has a promising application potential in working environment of PEMFCs. • Nitrogen-doped porous carbon supports (N–PPCs) were obtained via using petroleum vacuum residues as carbon source. • Pt NPs (1.8 nm) were loaded in situ on the N-PPC attributed to the porous confinement and metal-support interaction. • The (111) plane of Pt NPs has lattice compression (1.08%) strain caused by strong metal support interaction. • Pt/N-PPC reached a power density of 866 mW cm−2 as a cathode catalyst for H 2 –O 2 fuel cells. [ABSTRACT FROM AUTHOR]

Oral leukoplakia (OLK) is the most common oral potentially malignant disorder (OPMD), which can be malignantly transformed into oral squamous cell carcinoma (OSCC). Peroxiredoxin1(Prx1) has been predicted to bind to Prohibitin2 (PHB2), which confers to affect OLK progression; however, the mechanism of Prx1/PHB2 mediated mitophagy involved in OLK remains unclear. This study aimed to explore the mechanism of the Prx1/PHB2 axis on senescence in OLK through mediating mitophagy. The positive rate of Ki67 and the expression of p21, p16, PHB2, and LC3 in human normal, OLK, and OSCC tissues were detected by immunohistochemical staining. The mitophagy and mitochondrial function changes were then analyzed in Prx1 knockdown and Prx1C52S mutations in dysplastic oral keratinocyte (DOK) cells treated with H 2 O 2. In situ Proximity Ligation Assay combined with co-immunoprecipitation was used to detect the interaction between Prx1 and PHB2. Clinically, the positive rate of Ki67 progressively increased from normal to OLK, OLK with dysplasia, and OSCC. Higher p21, p16, PHB2, and LC3 expression levels were observed in OLK with dysplasia than in normal and OSCC tissues. In vitro , PHB2 and LC3II expression gradually increased with the degree of DOK cell senescence. Prx1/PHB2 regulated mitophagy and affected senescence in H 2 O 2 -induced DOK cells. Furthermore, Prx1C52S mutation specifically reduced interaction between Prx1 and PHB2. Prx1Cys52 is associated with mitochondrial reactive oxygen species (ROS) accumulated and cell cycle arrest. Prx1Cys52 functions as a redox sensor that binds to PHB2 and regulates mitophagy in the senescence of OLK, suggesting its potential as a clinical target. [ABSTRACT FROM AUTHOR]

Aberrant activation of autophagy in triple-negative breast cancer (TNBC) has led researchers to investigate potential therapeutic strategies targeting this process. The regulation of autophagy is significantly influenced by METTL3. Our previous research has shown that the Panax ginseng -derived compound, 20(R)-panaxatriol (PT), has potential as an anti-tumor agent. However, it remains unclear whether PT can modulate autophagy through METTL3 to exert its anti-tumor effects. Our objective is to investigate whether PT can regulate autophagy in TNBC cells and elucidate the molecular mechanisms. For in vitro experiments, we employed SUM-159-PT and MDA-MB-231 cells. While in vivo experiments involved BALB/c nude mice and NOD/SCID mice. In vitro , TNBC cells were treated with PT, and cell lines with varying expression levels of METTL3 were established. We assessed the impact on tumor cell activity and autophagy by analyzing autophagic flux, Western Blot (WB), and methylation levels. In vivo , subcutaneous transplantation models were established in BALB/c nude and NOD/SCID mice to observe the effect of PT on TNBC growth. HE staining and immunofluorescence were employed to analyze histopathological changes in tumor tissues. MeRIP-seq and dual-luciferase reporter gene assays were used to identify key downstream targets. Additionally, the silencing of STIP1 Homology And U-Box Containing Protein 1 (STUB1) explored PT's effects. The mechanism of PT's action on STUB1 via METTL3 was elucidated through mRNA stability assays, mRNA alternative splicing analysis, and nuclear-cytoplasmic mRNA separation. In both in vivo and in vitro experiments, it was discovered that PT significantly upregulates the expression of METTL3, leading to autophagy inhibition and therapeutic effects in TNBC. Simultaneously, through MeRIP-seq analysis and dual-luciferase reporter gene assays, we have demonstrated that PT modulates STUB1 via METTL3, influencing autophagy in TNBC cells. Furthermore, intriguingly, PT extends the half-life of STUB1 mRNA by enhancing its methylation modification, thereby enhancing its stability. In summary, our research reveals that PT increases STUB1 m6A modification through a METTL3-mediated mechanism in TNBC cells, inhibiting autophagy and further accentuating its anti-tumor properties. Our study provides novel mechanistic insights into TNBC pathogenesis and potential drug targets for TNBC. Our study has revealed that in TNBC cells, PT can suppress autophagy and exert its anti-tumor effects by enhancing the stability of STUB1 mRNA through a METTL3-dependent m6A modification mechanism. [Display omitted] [ABSTRACT FROM AUTHOR]

Biogenic volatile organic compounds (BVOCs) emitted by plants play a crucial role in ozone (O 3) formation. Avoiding urban air quality trade-offs of urban greening involves selecting low-emission and O 3 forming potential (OFP) plants. Using a dynamic enclosure system and the TD-GC-MS technique, we measured BVOC emissions from 47 common urban greening plant species in northern China. The potential to form O 3 was estimated based on the emission quantification of 63 compounds and their maximum incremental reactivity (MIR) values. The results indicated that isoprene and most of monoterpene dominated BVOC emissions. Most of the broad-leaved trees were isoprene emitter, whereas needle-leaved and some broad-leaved trees emitted monoterpene and sesquiterpene. Alkene emissions, such as 1-hexene, were relatively low, while Phoebe zhennan exhibited higher aromatics such as m-ethyltoluene. Broad-leaved trees had a higher potential for O 3 generation compared to needle-leaved trees. BVOC emission rates and OFP varied significantly among plant species, ranging from 0.08 to 112.23 μg/(g h) and 0.33–1130.75 μg/(g h), respectively. To minimize BVOC emissions and O 3 pollution, we determined a list of preferred urban greening plants using hierarchical cluster analysis combined BVOC emission rates and OFPs. Based on our findings, we recommend incorporating plants with low BVOC emissions and OFPs, such as Eucommia ulmoides , Firmiana platanifolia , and Cercis chinensis , in future urban greening plans to prevent strengthening O 3 pollution in northern China. [Display omitted] • BVOC emissions of 47 urban greening plant species were measured in northern China. • BVOC emissions and composition, and OFPs differed significantly among plant species. • OFP of a plant was determined by both BVOC emission level and compound composition. • Preferred urban greening plant species were selected by integrating emission and OFP. [ABSTRACT FROM AUTHOR]

In the study of the durability of concrete structures, the chloride ion diffusion coefficient (D t) is a key parameter that directly affects the prediction of concrete's service life. This study aims to explore the relationship between the chloride ion diffusion coefficient in concrete and the "curing age (t ref)" and "exposure time (t)." By conducting long-term curing and seawater exposure experiments on three different mixes of high-performance concrete samples, we collected experimental data with a curing age of 3 years and a seawater exposure time of 4.5 years. Through in-depth analysis of these data, we found that there is a significant power function relationship between the chloride ion diffusion coefficient and exposure time, while the relationship with curing age is not significant. This finding suggests that in the derivation of the concrete chloride ion diffusion theory model, the time range of the definite integral of D t should be from 0 to t, rather than from t ref to t ref +t. Furthermore, we have validated the concrete life prediction model using actual data from the Swedish Marine Exposure Station, further confirming the accuracy and reliability of our research results. This study provides a more scientific and accurate theoretical basis for the durability assessment and service life prediction of concrete structures. • ClinConc and ChaDuraLife V1.0 differ in considering "curing age (t ref)" in chloride diffusion theory. • Concrete chloride ion diffusion coefficient relates to "exposure time (t)" via a power function. • In the chloride ion diffusion model, D t 's integral time range is 0∼t, not t ref ∼t ref +t. • ChaDuraLife V1.0 outperforms ClinConc in predicting concrete chloride ion diffusion. [ABSTRACT FROM AUTHOR]

Model-based control approaches are inadequate to solve the marine surface vehicle (MSV) path-following problem, especially under adverse environments. To effectively deal with the MSV path-following problem, model-free deep reinforcement learning (DRL) based methods have been developed. However, defining an efficient reward function for DRL in path following tasks is rather difficult. Providing expert demonstration is often easier than designing effective reward functions. Thus, we propose a model-free stable adversarial inverse reinforcement learning (SAIRL) algorithm that only adopts the state of MSV and reconstructs the reward function from the expert demonstration. The SAIRL algorithm is designed to guarantee the prescribed MSV path following accuracy and training stability. It utilizes an alternative loss function and dual-discriminator framework to dissolve the issue of policy collapse, which arises due to the vanishing gradient of the discriminator. Simulations and experiments have validated that the SAIRL algorithm outperforms other baseline algorithms in terms of path-following accuracy and stability of convergence. • A model-free inverse reinforcement learning approach is proposed for path following. • Reconstructing reward function from demonstration data supersedes manual design. • A dual-discriminator framework is proposed to enhance convergence stability. [ABSTRACT FROM AUTHOR]

In this work, we comparatively analyzed the structure and antioxidant activities of different polysaccharide fractions from Arctium lappa L. A total of four water-soluble polysaccharide fractions (ALP-1, ALP-2, ALP-3 and ALP-4) were obtained from the roots of Arctium lappa L. They differed in monosaccharide composition, molecular weight and linkage mode. ALP-1 and ALP-2 mainly consisted of fructose, with average molecular weights of 2.676 × 103 and 2.503 × 104 g/mol, respectively. ALP-3 and ALP-4 were mainly composed of fructose, arabinose and galactose, with average molecular weights of 9.709 × 104 and 6.790 × 104 g/mol, respectively. Furthermore, Fourier transform infrared spectrometry, methylation analysis and nuclear magnetic resonance spectroscopy suggested that the main polysaccharide ALP-1 had a linear chain of (1 → 2)-linked β -D- Fructofuranosyl backbone (n ≈ 15) linked to a terminal (1 → 2)-linked α - d - Glucopyranosyl at the non-reducing end. All five polysaccharides displayed high antioxidant ability, especially ALP-4 in H 2 O 2 -induced HepG2 cell model and ALP-1 in metronidazole [MET]-induced zebrafish model. These findings provided comparative information on the structure and biological activity of different burdock polysaccharides and highlighted their potential as antioxidants in functional foods. [Display omitted] • Four purified polysaccharide components were obtained from Arctium lappa L. • They differed in monosaccharide composition, molecular weight and linkage mode. • The main component had a (1 → 2)-linked β -D- Fructofuranosyl chain structure. • ALP-4 showed the most excellent antioxidant ability in H 2 O 2 -induced HepG2 cells. • ALP-1 had the best protective effect on metronidazole-damaged zebrafish embryos. [ABSTRACT FROM AUTHOR]

Pectins are highly sought after as food additives, functional ingredients, and structural polymers. So far, no study has been performed on the extraction, characterization, and application of pectins from garlic pomace. In this study, a medium-sized low-methoxyl pectin rich in rhamnogalacturonan-I (RG-I) and galactose was prepared from garlic pomace (termed "GP"; molecular weight, Mw, 324.08 kDa; degree of methyl esterification, DM, 48.10%; RG-I, 35.20%), via citric acid-water extraction at 65 °C for 120 min and ethanol precipitation. GP contained six neutral monosaccharides (fucose, rhamnose, arabinose, galactose, glucose, and xylose) and two acidic monosaccharides (galacturonic acid and glucuronic acid), and could protect zebrafish against metronidazole-induced oxidative damage. Compared with commercial citrus pectin, GP had a comparable Mw, much more RG-Is and homogalacturonans, higher protein and phenolic contents, higher degree of branching, lower crystallinity, higher thermal stability (over 30–377 °C), higher in vitro and in vivo antioxidant capacities, higher viscosity, and higher emulsifying and emulsion-stabilizing abilities. Accordingly, garlic pomace was a good source of RG-I-rich and galactose-rich pectins with high emulsifying and antioxidant capacities. GP can be used for making foods and pharmaceuticals possessing simultaneously high emulsifying, emulsion-stabilizing, and antioxidant capacities. This study demonstrates a sustainable garlic waste valorization approach. [Display omitted] • Pectins rich in RG-I and galactose (GP) were prepared from garlic pomace. • GP was a medium-sized low-methoxyl pectin with a high degree of branching. • GP showed more excellent emulsifying abilities than commercial citrus pectin. • GP effectively protected zebrafish against metronidazole-induced oxidative damage. • GP is a good ingredient/additive with high emulsifying and antioxidant capacities. [ABSTRACT FROM AUTHOR]

Lack of exercise may reduce the quality of life, physical capability, and functional capability of dialysis patients. Home-based exercise seems to be a desirable form of low-cost intervention. But the effectiveness of this intervention in the dialysis population is still unclear. The purpose of this meta-analysis is to provide effective evidence to determine the impact of home-based exercise on functional capacity, physical capacity, muscular strength, biochemical parameters, and health-related quality of life among dialysis patients with end-stage renal disease (ESRD). PubMed, Embase, Cochrane Library, and Web of Science were searched from inception to May 2023, to identify potential randomized controlled trials (RCTs) assessing the effectiveness of home-based exercise in dialysis patients with ESRD. Two independent reviewers selected studies, extracted data, and assessed the risk of bias using the Cochrane tool. Evidence summary using fixed or random effects for meta-analysis. Twelve RCTs including 1008 dialysis patients met the inclusion criteria. The meta-analysis showed significant effects of home-based exercise on physical capacity. Seven studies reported the results of the 6-min walking test, compared with short-term (0–3 months) home-based exercise (P = 0.76), long-term (3–6 months) interventions (P < 0.001) can significantly improve the results of the 6-min walking test. The results showed that home-based exercise did significantly improve patients' VO 2 peak (P = 0.007). Compared with center-based exercise or usual care, home exercise did not significantly improve handgrip strength, quality of life or CRP and other biochemical parameters (P > 0.05). The results showed that long-term home-based exercise can improve walking ability. In addition, home-based exercise had the benefit on the VO 2 peak of ESRD patients receiving dialysis patients. However, there was no statistically significant difference in handgrip strength, health-related quality of life, CRP, and other biochemical parameters. • This is the first article to evaluate the impact of home-based exercise in dialysis patients with end-stage renal disease. • Home-based exercise improves physical capacity and functional capacity. • The long-term (3–6 months) home-based exercise can significantly improve walking ability compared to short-term exercise at home. [ABSTRACT FROM AUTHOR]

Genomic instability is an important characteristic of cancer, which promotes clonal evolution and tumorigenesis by increasing the frequency of gene destruction and loss of genome integrity. Generally, the maintenance of genomic stability depends significantly on the accurate regulation and timely repair of different genomic scales, ranging from DNA sequence to chromatin higher-order structures to chromosomes. Once irreversible damage and imperfect repair occurred, the resulting genomic instability can lead to a higher risk of tumorigenesis. However, how these factors disrupt genomic stability and their specific tumorigenic mechanisms remain unclear. Inspiringly, numerous studies have confirmed that long noncoding RNAs (lncRNAs), an important regulator of epigenetic inheritance, are functional in such process. Thus, this review aimed to discuss the vital factors that may lead to genomic instability at these multiple genomic scales, with an emphasis on the role of lncRNAs in it. • LncRNAs is a common modulator of genomic instability at different scales from chromosomes to DNA bases during tumorigenesis. • LncRNAs affect aneuploidy formation and telomere length through mitotic checkpoint, centromere and telomere regulation. • LncRNAs interact with important stability-regulation factors of TAD and chromatin loop structures. • LncRNAs modulate DNA resection and RPA covering, repair-proteins recruitment, and DNA connection in DSB repair process. [ABSTRACT FROM AUTHOR]

The anisotropy of compression response and energy absorption of fiber enforced porous ceramics by directional freeze-casting have been investigated to infer the failure mechanism. An enhanced porous ceramic structured with fiber-bridging-lamellar walls was synthesized by directionally freezing nano spherical alumina suspension with different fiction of alumina microfibers. Due to the anisotropic microstructure, the mechanical properties of the freeze-casting ceramics are closely related to the orientation of the applied stress. Different orientations of loads correspond to the different deformation mechanisms under the load. The compression experiments under different orientations were carried out, and the failure mechanism was judged by the energy absorption characteristics and compression response. In contrast to traditional freeze-casting ceramics, the scaffolds supported with fiber bridges have higher mechanical properties (up to 15 MPa in compressive strength and density up to 0.76 g/cm3), and their failure behavior tends to plastic fracture, which increases toughness and availability without decreasing porosity and pore size. [ABSTRACT FROM AUTHOR]

Randomized trials of people with peripheral artery disease (PAD) and intermittent claudication have traditionally used maximal treadmill walking distance as the primary outcome, but the 6-minute walk test is increasingly used as a primary outcome in randomized trials of PAD. This study compared relative changes in maximal treadmill walking distance versus 6-minute walk distance in response to a therapeutic intervention or control in randomized trials of participants with PAD. Data from four randomized trials of therapeutic interventions in participants with PAD that measured both 6-minute walk and treadmill walking performance at baseline and the 6-month follow-up were combined. Two trials studied supervised treadmill exercise, one studied home-based walking exercise, and one studied resveratrol. Of 467 participants (mean age, 69.8; standard deviation, 9.7), the mean ankle-brachial index was 0.66 (standard deviation, 0.17). At the 6-month follow-up, participants with PAD randomized to control or placebo significantly declined in 6-minute walk distance (−10.2 m; 95% confidence interval, −18.2 to −2.2; P =.013), but improved maximal treadmill walking distance (+25.7 m; 95% CI, +6.0 to +45.3 m; P =.010; difference between change in 6-minute walk versus maximal treadmill walking distance: −37.3 m; 95% CI, −56.4 to −18.2; P <.001). Home-based exercise improved the 6-minute walk distance by 43.2 m (95% CI, +28.4 to +57.9), and supervised treadmill exercise improved the 6-minute walk distance by 25.0 m (95% CI, +14.7 to +35.2; mean difference, +18.2 m favoring home-based exercise [95% CI, +0.2 to +36.2 m; P =.048]). Among all participants, the presence (vs absence) of treadmill exercise training was associated with a 141.3-m greater improvement in maximal treadmill walking distance compared to 6-minute walk distance (95% CI, 88.2-194.4; P <.001), suggesting a benefit from treadmill training on the treadmill outcome. Maximal treadmill walking distance and the 6-minute walk distance are not interchangeable outcomes in participants with PAD. Participants with PAD randomized to control groups improved treadmill walking distance but simultaneously meaningfully declined in 6-minute walk distance. Supervised treadmill exercise training amplified improvement in treadmill walking distance because of a training to the outcome measure phenomenon. [ABSTRACT FROM AUTHOR]

To discover novel anti-fibrotic agents, a series of UDCA-aminopyrimidine hybrids were designed and synthesized as potent ATX inhibitors by molecular hybridization strategy. The ATX inhibitory activities of all synthesized compounds were evaluated using the LPC choline release assay. The preliminary structure-activity relationship was concluded. Among them, 12a and 12h exhibited the strongest ATX inhibitory activities with IC 50 values of 7.62 ± 0.62 and 7.51 ± 0.72 nM respectively, which were 9-fold more effective than the positive control drug GLPG-1690. Molecular docking studies revealed that 12a and 12h occupied the hydrophobic pocket and tunnel of the ATX binding site. The cytotoxicity assay of 12a and 12h revealed that they had no obvious toxicity at concentrations up to 80 μM, therefore their anti-hepatic fibrosis and anti-pulmonary fibrosis activities were further investigated. The results suggested that 12a and 12h significantly decreased the gene and protein expression of α-SMA, COL1A1 and FN in both TGF-β1-induced HSC-LX2 and CCC-HPF-1 cells. In addition, 12a and 12h significantly inhibited cells migration in both TGF-β1-induced HSC-LX2 and CCC-HPF-1 cells. Preliminary mechanistic studies indicated that 12a and 12h exerted anti-hepatic fibrosis and anti-pulmonary fibrosis effects by inhibiting the TGF-β/Smad signaling pathway. Overall, our findings suggested that 12a and 12h might be two promising anti-fibrotic agents, or might serve as two new lead compounds for the further development of anti-fibrotic agents. [Display omitted] • Novel ursodeoxycholic acid (UDCA)-aminopyrimidine hybrids were synthesized. • Compounds 12a and 12h displayed significant ATX inhibitory activity. • Compounds 12a and 12h significantly decreased the gene and protein expression of α-SMA, COL1A1 and FN. • Compounds 12a and 12h markedly inhibited TGF-β1-induced migration of HSC-LX2 and CCC-HPF-1 cells. • Compound 12a and 12h exerted their anti-fibrotic activities through the inhibition. [ABSTRACT FROM AUTHOR]

• A numerical analysis model is developed for the arc of hybrid welding with T-joint. • The interaction behavior between arc and laser-induced metal vapor during welding process can be simulated. • Laser-induced metal vapor has a cooling effect on the arc. • The influence of laser rotation frequency on arc and laser-induced metal vapor is discussed. • The influence of laser rotation radius on arc and laser-induced metal vapor is discussed. In order to improve the reliability and stability of complex joints hybrid welding, this paper establishes an arc numerical analysis model, studies the T-joint high-frequency rotating laser-GMAW hybrid welding arc physical characteristics, and expounds the effects of laser rotation frequency along with rotation radius on arc plasma temperature, velocity, and metal vapor concentration field distribution. The research results show: the arc is more likely to start on the bottom plate and vertical plate surfaces, and the current density at the angle between the plates decreases significantly; temperature drops at the hybrid welding arc tail, the current effective distribution radius was reduced, and current density was more concentrated; the laser beam rotation frequency increases, the eruption speed of the metal vapor ejected from the keyhole decreases, while the meeting height of arc plasma and laser-induced metal vapor decreases; and, with an increase in rotation radius, the laser rotation speed increases accordingly. At the same rotation frequency, the injected metal vapor kinetic energy and rising height are reduced. [ABSTRACT FROM AUTHOR]

• The compressive strength and dynamic elastic modulus of HPC exposed in salt lake brine increased first and then decreased. • HPC has good long-term corrosion resistance in salt lake brine. • Under the condition of long-term brine erosion, HPC specimens still maintain the characteristics of high strength and brittleness and relatively dense internal structure. • The three-dimensional concrete meso -model, considering the random aggregate shape, can be used to simulate the uniaxial compression mechanical behavior of HPC specimens in a salt lake brine environment. The study investigated the corrosion resistance, corrosion micro-mechanisms, and the uniaxial compression stress–strain constitutive relationship of high-performance concrete (HPC) specimens subjected to long-term brine corrosion in an underground salt lake environment (Xining, China), which possesses a salt content of 180894.5mg/L. A three-dimensional random aggregate concrete meso -model was established considering the mesostructural characteristics of concrete. The mechanical behavior of HPC was assessed using the LS-DYNA software platform. The findings indicated that both the compressive strength and the dynamic elastic modulus of HPC demonstrated a pattern of initial increase, followed by a decrease, with extended brine exposure. Nevertheless, after 10 years of exposure to salt lake brine, the compressive strength of the HPC samples was still considerably greater than their original strength, with minimal evident corrosion damage to the concrete. Physical and chemical corrosion products formed exclusively in the spherical pores created by the air-entraining agent within the shallow layer of HPC, without notable micro-cracks or spalling. The HPC specimens exposed to brine for ten years under uniaxial compression load exhibited typical characteristics of splitting failure. In addition, the results from the mesoscopic numerical simulations aligned well with the experimental findings. The study shows that the three-dimensional random aggregate concrete mesoscopic model can simulate the uniaxial compressive mechanical behavior of HPC specimens under long-term corrosion conditions. [ABSTRACT FROM AUTHOR]

Biogenic volatile organic compounds (BVOCs) are important drivers of atmospheric chemical composition and accurate model simulations require characterization of the emissions associated with specific vegetation types which is typically determined using enclosure measurements. Static enclosure techniques were used for past BVOC emission measurement studies, especially in the 1960s–1980s, but are no longer widely used because of concerns that the resulting emission rates are not representative. The main advantages of the static approach are the capability for rapid measurements and a lower detection limit that enables the use of less sensitive analytical techniques. We evaluate a version of the static approach which we call the semi-static approach. In order to evaluate the performance of the semi-static approach for BVOCs emission measurements, multiple replicate measurements for different plants were conducted in a laboratory growth chamber using both semi-static and dynamic enclosure techniques. Variability of replicate measurements was calculated and the results from the two techniques were compared. The semi-static technique provided consistent measurements for isoprene but not for α-pinene, β-pinene and other compounds that are stored in leaves. The measured isoprene emission factors were much higher than dynamic measurements. There were a large number of compounds to be detected by dynamic technique that could not be detected by the semi-static technique. But the semi-static technique could still provide qualitative information on categorization of non, low and high emitters for some compounds. • Semi-static method cannot provide consistent measurements for VOCs stored in leaf. • The measured isoprene emission factors are much higher than dynamic measurements. • Semi-static technique can detect fewer compounds than dynamic one. [ABSTRACT FROM AUTHOR]