Nano and microplastics (NPs/MPs) have received widespread attention in recent years. Because of their large specific surface area and hydrophobicity, NPs/MPs can adsorb various organic contaminants. ...This article gives a brief review of the sorption behavior of organic contaminants to NPs/MPs, summarizes the possible sorption mechanisms, and analyzes the influencing factors in the environment on the sorption behavior and mechanisms of NPs/MPs. The main mechanisms of sorption of organic contaminants to NPs/MPs are partitioning, surface sorption (hydrogen bonding, π-π interaction, electrostatic interaction, and van der Waals force), and pore filling. The sorption behavior of organic contaminants to NPs/MPs is not only affected by the properties of the NPs/MPs and the organic contaminants, but also by the solution chemistry, such as the pH, ionic strength, and dissolved organic matter.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
A highly enantioselective oxidative cyclopropanation of 1,6‐enynes catalyzed by cationic AuI/chiral phophoramidite complexes is presented. The new method provides convenient access to densely ...functionalized bicyclo3.1.0hexanes bearing three contiguous quaternary and tertiary stereogenic centers with high enantioselectivity (up to e.r. 98:2). Control experiments suggest that the quinoline moiety of the β‐gold vinyloxyquinolinium intermediate in the reaction plays an important role in promoting good enantioselectivity through a transitional auxiliary effect in the transition state.
Playing it safe: A highly enantioselective oxidative cyclopropanation of 1,6‐enynes with cationic AuI/chiral phosphoramidite catalysts provided convenient access to densely functionalized bicyclo3.1.0hexanes with three contiguous quaternary and tertiary stereogenic centers (see scheme; up to 92 % yield, e.r. 98:2). Control experiments suggest that the quinoline moiety in the oxidant plays an essential role in the enantioselective cyclopropanation.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Atmospheric pressure fluctuations can induce subsurface airflow, affecting Volatile Organic Compound (VOC) contaminant migration in the vadose zone. When modeling this process, traditional vapor ...intrusion models have relied on the assumption of local equilibrium conditions and neglected kinetic mass transfer processes among different phases. In this study, a nonequilibrium multiphase flow and transport model was developed to investigate the impact of atmospheric pressure fluctuations on VOC release from groundwater to the atmosphere. Kinetic mass transfer processes between vapor & liquid phases, and between liquid & solid phases were taken into consideration. A series of soil column experiments with downward/upward pumped gas flow were conducted to validate the model. The experimental results imply the necessity to use nonequilibrium models for quantifying the impact of atmospheric pressure fluctuation. The validated model was used to investigate the role of atmospheric pressure fluctuations for various practical hydrogeologic settings under daily pressure fluctuations. It was found that when the soil organic carbon content is relatively large, the nonequilibrium model more accurately represents VOC migration than a traditional equilibrium model. Therefore, this study suggests the need to apply nonequilibrium vapor intrusion models at sites with high soil organic matter content.
Key Points
A nonequilibrium model was developed to depict the effect of atmospheric pressure fluctuation on contaminant transport in vadose zone
Nonequilibrium model could better simulate the variations of gaseous concentration and total soil concentration in vadose zone
A larger soil organic matter content would lead to a larger difference between equilibrium and nonequilibrium models
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Recent studies demonstrated that metformin exerts anti-neoplastic effect in a spectrum of malignancies. However, the mechanism whereby metformin affects various cancers, including gastric cancer, is ...poorly elucidated. Considering apoptosis plays critical role in tumorigenesis, we, in the present study, investigated the in vitro apoptotic effect of metformin on human gastric cancer cell and the underlying mechanism. Three differently-differentiated gastric cancer cell lines, MKN-28, SGC-7901 and BGC-823, along with one noncancerous gastric cell line GES-1 were used. We found that metformin treatment selectively induces apoptosis in the 3 cancer cell lines, but not the noncancerous one, as confirmed by flow cytometry, Caspase-Glo assay and western blotting against PARP and cleaved caspase 3. Moreover, the apoptotic effect of metformin seems to correlate negatively with the differentiation degree of gastric cancer. Metformin-induced apoptosis may be partially mediated through inhibition of anti-apoptotic survivin. Additionally, AMPK and mTOR, 2 important regulatory molecules responsible for metformin action, were investigated for their possible involvements in metformin-induced apoptosis of gastric cancer cell. AMPK knockdown by siRNA restores metformin-inhibited survivin expression and partially abolishes metformin-induced apoptosis. Similarly, forced overexpression of mTOR downstream effector p70S6K1 relieves metformin-induced inhibition of survivin and partly attenuates metformin-induced apoptosis. More importantly, survivin overexpression alleviates metformin-induced apoptosis. Xenograft nude mouse experiment also confirmed that AMPK/mTOR-mediated decrease of suvivin is in vivo implicated in metformin-induced apoptosis. Taken together, these evidences suggest that AMPK/mTOR-mediated inhibition of survivin may partly contribute to metformin-induced apoptosis of gastric cancer cell.
The first intramolecular enantioselective cyclopropanation of indenes and trisubstituted alkenes was accomplished by using new chiral phosphine X5 derived gold(I) complexes. This reaction is a ...straightforward, efficient method for constructing 5–3–6 fused-ring compounds with two vicinal all-carbon quaternary stereogenic centers, a core structure shared by numerous pharmacological products, and bioactive compounds. The salient features of this transformation include high enantioselectivity (up to >98% ee), excellent yield (>97%), and nice functional group tolerance.
Full text
Available for:
IJS, KILJ, NUK, PNG, UL, UM
Fatty acids (FAs) can serve as energy for poultry, maintain normal cell structure and function, and support a healthy immune system. Although the addition of polyunsaturated fatty acids (PUFAs) to ...the diet has been extensively studied and reported, the mechanism of action of saturated fatty acids (SFAs) remains to be elucidated. We investigated the effect of 0.04% dietary myristic acid (MA) on slaughter performance, lipid components, tissue FAs, and the transcriptome profile in chickens. The results showed that dietary MA had no effect on slaughter performance (body weight, carcass weight, eviscerated weight, and pectoral muscle weight) (P > 0.05). Dietary MA enrichment increased MA (P < 0.001) and triglycerides (TGs) (P < 0.01) levels in the pectoral muscle. The levels of palmitic acid, linoleic acid (LA), arachidonic acid (AA), SFAs, monounsaturated fatty acids (MUFAs), and PUFAs were significantly higher (P < 0.01) in the MA supplementation group compared to the control group. However, there were no significant differences in the ratios of PUFA/SFA and n6/omega-3 (n3) between the two groups. The MA content was positively correlated with the contents of palmitic acid, LA, linolenic acid (ALA), n3, n6, SFAs, and unsaturated fatty acids (UFA). DHCR24, which is known to be involved in steroid metabolism and cholesterol biosynthesis pathways, was found to be a significantly lower in the MA supplementation group compared to the control group (P < 0.05, log2(fold change) = -0.85). Five overlapping co-expressed genes were identified at the intersection between the differential expressed genes and Weighted Gene Co‑expression Network Analysis-derived hub genes associated with MA phenotype, namely BHLHE40, MSL1, PLAGL1, SRSF4, and ENSGALG00000026875. For the TG phenotype, a total of 28 genes were identified, including CHKA, KLF5, TGIF1, etc. Both sets included the gene PLAGL1, which has a negative correlation with the levels of MA and TG. This study provides valuable information to further understand the regulation of gene expression patterns by dietary supplementation with MA and examines at the molecular level the phenotypic changes induced by supplementation with MA.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Cathepsin B (CatB) is a cysteine proteolytic enzyme widely expressed in various cells and mainly located in the lysosomes. It contributes to the pathogenesis and development of many diseases. ...However, the role of CatB in viral myocarditis (VMC) has never been elucidated. Here we generated the VMC model by intraperitoneal injection of coxsackievirus B3 (CVB3) into mice. At day 7 and day 28, we found CatB was significantly activated in hearts from VMC mice. Compared with the wild-type mice receiving equal amount of CVB3, genetic ablation of CatB (Ctsb-/-) significantly improved survival, reduced inflammatory cell infiltration, decreased serum level of cardiac troponin I, and ameliorated cardiac dysfunction, without altering virus titers in hearts. Conversely, genetic deletion of cystatin C (Cstc-/-), which markedly enhanced CatB levels in hearts, distinctly increased the severity of VMC. Furthermore, compared with the control, we found the inflammasome was activated in the hearts of wild-type mice with VMC, which was attenuated in the hearts of Ctsb-/- mice but was further enhanced in Cstc-/- mice. Consistently, the inflammasome-initiated pyroptosis was reduced in Ctsb-/- mice hearts and further increased in Cstc-/- mice. These results suggest that CatB aggravates CVB3-induced VMC probably through activating the inflammasome and promoting pyroptosis. This finding might provide a novel strategy for VMC treatment.
Full text
Available for:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Sarcopenia has been recognized as the third category of disabling complications in patients with type 2 diabetes mellitus(T2DM), in addition to micro- and macrovascular complications. Sodium-glucose ...co-transporter 2 (SGLT2) inhibitors are innovative glucose-lowering treatments that have been shown to reduce body weight and enhance cardiovascular and renal outcomes. However, there is vigilance that SGLT2 inhibitors should be taken cautiously because they target skeletal muscle and may raise the risk of sarcopenia. Herein, we conducted a meta-analysis of randomized controlled trials to evaluate the effects of SGLT2 inhibitors on sarcopenia in patients with T2DM.
Relevant studies were obtained from PubMed, Embase, Medicine, Cochrane, and Web of Science databases to determine eligible studies until February 2023, without any language restrictions. A random effects model was utilized irrespective of heterogeneity, and the I
statistic was used to evaluate study heterogeneity. The differences in results were measured using the weighted average difference (WMD) of the continuous data, along with a 95% confidence interval (CI).
A total of 25 randomized controlled trials with 2,286 participants were included. SGLT2 inhibitors significantly reduced weight-related changes and fat-related changes, including body weight(BW) (WMD= -2.74, 95% CI: -3.26 to -2.23, P<0.01), body mass index(BMI) (WMD= -0.72, 95% CI: -0.95 to -0.49, P<0.01), waist circumference(WC) (WMD= -1.60, 95% CI: -2.99 to -0.22, P=0.02), fat mass(FM)(WMD= -1.49, 95% CI: -2.18 to -0.80, P<0.01), percentage body fat(PBF) (WMD= -1.28, 95% CI: -1.83 to -0.74, P<0.01), visceral fat area(VFA)(WMD= -19.52, 95% CI: -25.90 to -13.14, P<0.01), subcutaneous fat area(SFA)(WMD= -19.11, 95% CI: -31.18 to -7.03, P=0.002), In terms of muscle-related changes, lean mass(LM)(WMD= -0.80, 95% CI: -1.43 to -0.16, P=0.01), and skeletal muscle mass(SMM) (WMD= -0.38, 95% CI: -0.65 to -0.10, P=0.007), skeletal muscle index(SMI) (WMD= -0.12, 95% CI: -0.22 to -0.02, P=0.02)were also significantly reduced. In addition, body water likewise decreased significantly (WMD=-0.96, 95% CI: -1.68 to -0.23, P=0.009).
As one of the most widely used hypoglycemic, SGLT2 inhibitors have beneficial effects on FM and BW weight loss in T2DM, such as BW, BMI, WC, FM, PBF, VFA, and SFA. However, the negative influence on muscle mass paralleled the reduction in FM and BW, and the consequent increased risk of sarcopenia warrants high attention, especially as patients are already predisposed to physical frailty.
https://www.crd.york.ac.uk/prospero/#myprospero, identifier PROSPERO (No.CRD 42023396278).
Normal aortic valves are composed of valve endothelial cells (VECs) and valve interstitial cells (VICs). VICs are the major cell population and have distinct embryonic origins in the endocardium and ...cardiac neural crest cells. Cell signaling between the VECs and VICs plays critical roles in aortic valve morphogenesis. Disruption of major cell signaling pathways results in aortic valve malformations, including bicuspid aortic valve (BAV). BAV is a common congenital heart valve disease that may lead to calcific aortic valve disease (CAVD), but there is currently no effective medical treatment for this beyond surgical replacement. Mouse and human studies have identified causative gene mutations for BAV and CAVD via disrupted VEC to VIC signaling. Future studies on the developmental signaling mechanisms underlying aortic valve malformations and the pathogenesis of CAVD using genetically modified mouse models and patient-induced pluripotent stem cells may identify new effective therapeutic targets for the disease.
•A sequential chemical extraction method was used to assay soil Si fractionations along different slope positions at the margin of a coastal wetland.•The Na2CO3-Si fraction accounted for 82%–90% of ...the labile Si in soil and sediment, mainly resulting from phytoliths and diatoms.•The storage of labile Si in sediment was significantly lower than that in soil.•With the influence of margin erosion under sea level rise, coastal wetland ecosystems will be an important source of Si to the estuary.
Silicon (Si) and its biogeochemical cycling play an important role in maintaining the functions of terrestrial and marine ecosystems. However, the effects of sea level rise on the biogeochemical cycling of Si in coastal wetlands remain poorly understood. To explore this impact on biogeochemical Si cycling, we sampled a gradient from sediment to soil without the impact of tidal inundation in the Beidagang Wetland Nature Reserve, and then assayed non-crystalline Si (labile Si), including mobile Si (CaCl2-Si), adsorbed Si (Acetic-Si), Si bound to soil organic matter (H2O2-Si), Si occluded in pedogenic oxides/hydroxide (Oxalate-Si), and amorphous Si (Na2CO3-Si) fractions. Analytical results showed that the content of CaCl2-Si ranged from 13.0 to 53.3 mg kg−1 and the content of Acetic-Si ranged from 32.3 to 80.9 mg kg−1, both of which were lower in sediments compared to soils. The content of H2O2-Si (84.1–160.1 mg kg−1) and Oxalate-Si (306.6–655.1 mg kg−1) in the soil profiles showed non-significant variations along the sampling slope. The Na2CO3-Si fraction accounted for 82%–90% of labile Si in soil and sediment, mainly being contributed from phytoliths or diatoms. Diatoms were only detected in sediment profiles. The storage of labile Si in sediment was significantly (p = 0.0009) lower than the storage in soil, suggesting that the coastal wetland ecosystems are an important source of Si to the estuary. With future sea level rise and increased margin erosion, the inter-transformation processes among different Si fractions would likely be weakened to increase dissolved Si for marine diatoms.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
PDF
