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The behavior of steel fiber-reinforced concrete (SFRC) exposed to simulated marine environments was investigated in this work. The cubic compressive strength as well as axial compressive and flexural properties of SFRC subjected to chloride attack was monitored over 36 months. Meanwhile, the chloride transport behavior in SFRC was also investigated. Furthermore, the effect of water-to-binder ratio (W/B), mineral admixtures, and exposure conditions on the mechanical properties and chloride transport of SFRC was analyzed. Results showed that many rust spots appeared on SFRC surfaces after 36 months of chloride attack, while the internal steel fibers remained intact despite chloride penetration depths over 20 mm. The SFRC specimens immersed in 3% NaCl solution for 36 months showed no decreases in their cubic compressive strengths, axial compressive strengths, flexural strengths and toughness as compared to unexposed specimens. However, the SFRC specimens exposed to drying-wetting cycles condition showed some slight degradations. In addition, the SFRC specimens with 20% fly ash showed higher chloride resistance than the specimens with 20% fly ash and 40% slag. This study provides more experimental data and evidences for the application of SFRC in a marine environment. [ABSTRACT FROM AUTHOR]

Palladium complexes of indane-based phosphine–oxazoline ligands with a spirocarbon stereogenic center were examined for asymmetric addition of arylboronic acids to cyclic N-sulfonyl imines. Excellent reaction activities (up to 99% yield) and enantioselectivities (up to 99% ee) were obtained with a broad scope of substrate. [ABSTRACT FROM AUTHOR]

The Holocene hydrological regime on the Heixiazi Island is critical for understanding the evolution of the East Asian summer monsoon (EASM) for the island's climate-sensitive location on the northern fringe of the EASM domain. In this paper, a marsh depression on the central island was selected to reconstruct the locally hydrological variation and to discuss its indications for the Holocene EASM evolution. This work is based on multi-proxy (magnetic susceptibility, grain size, loss-on-ignition, and carbonate content) analyses of 22 modern sedimentary samples with a water-level gradient of 0–66 cm and 100 cored sedimentary samples covering last ~ 9.0 ka BP. The proxies' hydrological significance was previously interpreted by the 22 modern samples using linear regression equations to construct their relationships to water-level changes. Among these proxies, the magnetic susceptibility, carbonate content, as well as the Md and sand fraction of grain size exhibit high-level relationships against the water-level changes with R2 > 0.6. Thus, these four proxies' linear-regression equations were selected and used on the 100 cored samples, and the Holocene water-level changes in the studied depression were quantitatively reconstructed. It shows that two relatively high water-level stages with strengthened EASM occurred during 8.0–4.5 ka BP and 3.0–1.4 ka BP, which were alternated by three low water-level stages with declined EASM during ~ 9.0–8.0 ka BP, 4.5–3.0 ka BP, and 1.4–0 ka BP, respectively. Among these fluctuations, the highest water-level stage with most strengthened EASM which is defined as the Holocene Monsoon Maximum occurred during 6.4–4.5 ka BP. Such a new evolution pattern of the EASM can be further supported by a large variety of records from monsoon-margin regions. We suggest the Holocene EASM evolution was generally associated with the thermal conditions in both the inner Eurasia landmass and the West Pacific Ocean, with an exception of the weak EASM before 8.0 ka BP due to the enhanced Siberia High with the dominance of the Eurasia ice sheet in the early Holocene. [ABSTRACT FROM AUTHOR]

Sulfur mustard (SM) is a powerful vesicant and one of the most harmful chemical warfare agents. Although having been studied for a long time, it is still difficult to fully elucidate the mechanisms of SM poisoning, and there is no effective antidote or specific treatment for SM injury. The investigations on toxicokinetics and tissue distribution of SM will help to understand its toxicity and provide a theoretical basis for pretreatment and therapy of SM poisoning. But the metabolic trajectory or fate of intact SM in vivo remains unclear, and there are insufficient experimental data to elucidate, due to its high reactivity and difficulty in biomedical sample analysis. In this paper, a sensitive method for the detection and quantification of intact SM in blood or tissues using isotope-dilution LC-MS/MS coupled with chemical conversion was developed. By transforming highly reactive SM into stable derivative product, the real concentration of intact SM in biological samples was obtained accurately. The toxicokinetics and tissue distribution studies of intact SM in rats were successfully profiled by the novel method after intravenous (10 mg/kg) or cutaneous administration (1, 3 and 10 mg/kg). The SM level in blood with peak time at 30-60 min determined in cutaneous exposure experiment was found much higher than previously reported, and the mean residence time in blood extended to 1-1.5 h. A significant accumulation of intact SM was observed in adipose tissues, including the perirenal fat, epididymal fat, subcutaneous fat and brown fat, in which the concentrations of SM were at least 15 times greater than those in non-adipose tissues in cutaneous exposed rats. The recovery of SM in body fat was calculated as 3.3 % of bioavailable SM (the bioavailability after cutaneous exposure was evaluated as 16 %). Thus, the adipose tissue was important for SM distribution and toxicity, which may pioneer a new model for both the prevention and treatment of SM exposure. [ABSTRACT FROM AUTHOR]

Understanding the response of carbon (C) accumulation to past climate changes can provide useful insights for predicting the fate of C in a future, warmer world. Here, we present data from three well-dated peat cores that reveal the history of wetland C accumulation in the Sanjiang Plain (China), and its links to Holocene climate and environmental changes. Regional C accumulation was largely governed by monsoon-driven depositional conditions. Before ~4400 cal year BP, the strong summer monsoon favored development of lakes with relatively slow and stable C accumulation rates, ~20 g C m year. Thereafter, with the sharp decline in summer monsoon precipitation, peatlands began to form at the expense of the paleolakes, leading to a roughly sixfold increase in the C accumulation rate. This was a consequence of the higher primary production in peatlands compared to lakes. During the interval from 4400 to 500 cal year BP, the gradually increasing C accumulation rate responded to the decreasing strength of the summer monsoon. The decline in C accumulation rate over the past 500 years is attributed to both the strengthened summer monsoon and intensified human influences. [ABSTRACT FROM AUTHOR]

Accumulating evidence from the last decade has shown that many pharmaceutical excipients are not pharmacologically inert but instead have effects on metabolic enzymes and/or drug transporters. Hence, the absorption, distribution, metabolism, and elimination (ADME) of active pharmaceutical ingredients (APIs) may be altered due to the modulation of their metabolism and transport by excipients. The impact of excipients is a potential concern for Biopharmaceutics Classification System (BCS)-based biowaivers, particularly as the BCS-based biowaivers have been extended to class 3 drugs in certain dosage forms. The presence of different excipients or varying amounts of excipients between formulations may result in bio-inequivalence. The excipient impact may lead to significant variations in clinical outcomes as well. The aim of this paper is to review the recent findings of excipient effects on gastrointestinal (GI) absorption, focusing on their interactions with the metabolic enzymes and transporters in the GI tract. A wide range of commonly used excipients such as binders, diluents, fillers, solvents, and surfactants are discussed here. We summarized the reported effects of those excipients on GI tract phase I and phase II enzymes, uptake and efflux transporters, and relevant clinical significance. This information can enhance our understanding of excipient influence on drug absorption and is useful in designing pharmacokinetic studies and evaluating the resultant data. [ABSTRACT FROM AUTHOR]

The 150-year historical changes in concentrations of pollution elements (Pb, Cu and Zn) in sediment profiles from two riparian freshwater wetlands along the Wusuli River (boundary river between China and Russia) were studied, and the ecological risk of heavy metals and their effects on four riparian wetlands during the urban development from Khanka Lake to Black Bear Island along the Wusuli River were assessed. Results showed that there are sharp increases of the enrichment factor and the ratio of anthropogenic/total of heavy metals in the sediment profiles during the 2000s, which showed that intensive human activities during city development had greatly affected heavy metals distribution since the 1960s. According to the principal component analysis, sediment textures, redox regimes, and organic matter contents accounted for 45.7, 23.6 and 16.5 % of the total variance of element concentrations, respectively. This study also showed that ecological risk of heavy metals was increased along the Wusuli River and closely related to the water quality of the rivers as their hydrological regimes likely affect wetlands. [ABSTRACT FROM AUTHOR]

The production of the anticoagulant drug heparin from non-animal sources has a number of advantages over the current commercial production of heparin. These advantages include better source material availability, improved quality control, and reduced concerns about animal virus or prion impurities. A bioengineered heparin would have to be chemically and biologically equivalent to be substituted for animal-sourced heparin as a pharmaceutical. In an effort to produce bioengineered heparin that more closely resembles pharmaceutical heparin, we have investigated a key step in the process involving the N-deacetylation of heparosan. The extent of N-deacetylation directly affects the N-acetyl/ N-sulfo ratio in bioengineered heparin and also impacts its molecular weight. Previous studies have demonstrated that the presence and quantity of N-acetylglucosamine in the nascent glycosaminoglycan chain, serving as the substrate for the subsequent enzymatic modifications (C5 epimerization and O-sulfonation), can impact the action of these enzymes and, thus, the content and distribution of iduronic acid and O-sulfo groups. In this study, we control the N-deacetylation of heparosan to produce a bioengineered heparin with an N-acetyl/ N-sulfo ratio and molecular weight that is similar to animal-sourced pharmaceutical heparin. The structural composition and anticoagulant activity of the resultant bioengineered heparin was extensively characterized and compared to pharmaceutical heparin obtained from porcine intestinal mucosa. [ABSTRACT FROM AUTHOR]

A sensitive and selective method for determination of ( S, R)-penehyclidine in rat plasma by liquid chromatography-tandem mass spectrometry is described. The procedure employed the use of an internal standard (I.S.) and a simple protein precipitation step. The method developed was linear from 0.1 to 100 ng mL−1, with a sensitivity of 0.1 ng mL−1 as the lower limit of quantification. The intra- and inter-day assay accuracy (relative error) was within 8.27% and precision (RSD) was below 6.7%. It was successfully applied to pharmacokinetic studies of ( S, R)-penehyclidine in rat plasma. [ABSTRACT FROM AUTHOR]

The whole tissue of the earthworm ( Eisenia andrei) was lyophilized and extracted to purify glycosaminoglycans. Fractions, eluting from an anion-exchange column at 1.0 M and 2.0 M NaCl, showed the presence of acidic polysaccharides on agarose gel electrophoresis. Monosaccharide compositional analysis showed that galactose and glucose were most abundant monosaccharides in both fractions. Depolymerization of the polysaccharide mixture with glycosaminoglycan-degrading enzymes confirmed the presence of chondroitin sulfate/dermatan sulfate and heparan sulfate in the 2.0 M NaCl fraction. The content of GAGs (uronic acid containing polysaccharide) in the 2.0 M NaCl fraction determined by carbazole assay was 2%. Disaccharide compositional analysis using liquid chromatography–electrospray ionization mass spectrometry (LC–ESI–MS) analysis after chondroitinase digestion (ABC and ACII), showed that the chondroitin sulfate/dermatan sulfate contained a 4- O-sulfo (76%), 2,4-di- O-sulfo (15%), 6- O-sulfo (6%), and unsulfated (4%) uronic acid linked N-acetylgalactosamine residues. LC–ESI–MS analysis of heparin lyase I/II/III digests demonstrated the presence of N-sulfo (69%), N-sulfo-6- O-sulfo (25%) and 2- O-sulfo- N-sulfo-6- O-sulfo (5%) uronic acid linked N-acetylglucosamine residues. [ABSTRACT FROM AUTHOR]

Acharan sulfate content from African giant snail ( Achatina fulica) was compared in eggs and snails of different ages. Acharan sulfate was not found in egg. Acharan sulfate disaccharide →4)-α- d-GlcNpAc (1→4)-α- l-IdoAp2S(1→, analyzed by SAX (strong-anion exchange)–HPLC was observed soon after hatching and increases as the snails grow. Monosaccharide compositional analysis showed that mole % of glucosamine, a major monosaccharide of acharan sulfate, increased with age while mole % of galactose decreased with age. These results suggest that galactans represent a major energy source during development, while acharan sulfate appearing immediately after hatching, is essential for the snail growth. The structures of neutral N-glycans released from eggs by peptide N-glycosidase F (PNGase F), were next elucidated using ESI-MS/MS, MALDI-MS/MS, enzyme digestion, and monosaccharide composition analysis. Three types of neutral N-glycan structures were observed, truncated (Hex2–4-HexNAc2), high mannose (Hex5–9-HexNAc2), and complex (Hex3-HexNAc2–10) types. None showed core fucosylation. [ABSTRACT FROM AUTHOR]

Recently, certain lots of heparin have been associated with an acute, rapid onset of serious side effects indicative of an allergic-type reaction. To identify potential causes for this sudden rise in side effects, we examined lots of heparin that correlated with adverse events using orthogonal high-resolution analytical techniques. Through detailed structural analysis, the contaminant was found to contain a disaccharide repeat unit of glucuronic acid linked β1→3 to a β-N-acetylgalactosamine. The disaccharide unit has an unusual sulfation pattern and is sulfated at the 2-O and 3-O positions of the glucuronic acid as well as at the 4-O and 6-O positions of the galactosamine. Given the nature of this contaminant, traditional screening tests cannot differentiate between affected and unaffected lots. Our analysis suggests effective screening methods that can be used to determine whether or not heparin lots contain the contaminant reported here. [ABSTRACT FROM AUTHOR]

The pollen flux in coniferous and deciduous broadleaved mixed forest in the Changbai Mountains is presented in one year's experiments. The results indicate that arboreal pollen percentages are more than 65% and pollen flux is higher than 5000 grain·cm²·a-1, while less than 2% and lower than 1000 grain·cm²·a-1 for shrubby pollen, and less than 20% and lower than 3000 grain·cm²·a-1 for herbaceous pollen for most samples at different heights. The pollen assemblages are similar to those in the samples under 8 m height where Pinus and Quercus are dominant and followed by the few non-local pollen types, and Fraxinus percentages are high with a few non-local pollen types at 16 m to 32 m height as well as non-local pollen clearly increased at 40 m height. Comparisons between pollen assemblages and vegetation composition suggest that similarities are higher for pollen trap samples than for surface moss samples. [ABSTRACT FROM AUTHOR]

Enfuvirtide (T20), is the first HIV fusion inhibitor approved for treatment of HIV/AIDS patients who fail to respond to the current antiretroviral drugs. However, its clinical application is limited because of short half-life, drug resistance and cross-reactivity with the preexisting antibodies in HIV-infected patients. Using an artificial peptide strategy, we designed a peptide with non-native protein sequence, AP3, which exhibited potent antiviral activity against a broad spectrum of HIV-1 strains, including those resistant to T20, and had remarkably longer in vivo half-life than T20. While the preexisting antibodies in HIV-infected patients significantly suppressed T20's antiviral activity, these antibodies neither recognized AP3, nor attenuated its anti-HIV-1 activity. Structurally different from T20, AP3 could fold into single-helix and interact with gp41 NHR. The two residues, Met and Thr, at the N-terminus of AP3 form a hook-like structure to stabilize interaction between AP3 and NHR helices. Therefore, AP3 has potential for further development as a new HIV fusion inhibitor with improved antiviral efficacy, resistance profile and pharmacological properties over enfuvirtide. Meanwhile, this study highlighted the advantages of artificially designed peptides, and confirmed that this strategy could be used in developing artificial peptide-based viral fusion inhibitors against HIV and other enveloped viruses. [ABSTRACT FROM AUTHOR]

The climate change in the Qaidam Basin has significant impacts on local humans and ecological environment. However, the humidity variation and relationship between climate factors in the Qaidam Basin remain insufficient. Here we study the modern climate change in the Qaidam Basin. The mean annual temperature in the Qaidam Basin has increased rapidly by 0.5 °C/10a between 1959 and 2022, exhibiting cycles of 9.1 a and 3.2 a. Concurrently, the pattern of precipitation variations has displayed an upward trend, with a rate of increase amounting to 9.2 mm/10a and a cycle of 2.5 a. The Qaidam Basin has witnessed a considerable increase in temperature since 1977, as indicated by the Mann–Kendall mutation test. Within the Qaidam Basin, the mutation point at which precipitation transitioned from a lesser amount to a more volume occurred in 2001. Furthermore, a reduction in the variation of evaporation was observed between 1959 and 2003, possibly attributed to decreased sunshine and wind speed within the basin. The moist coefficient (precipitation/evaporation) and absolute humidity serve as direct indicators of the level of humidity in the environment. The moist coefficient has displayed an upward trend, accompanied by a corresponding increase in absolute humidity. The lake area and vegetation coverage are indirect indicators that reflect the level of humidity in the environment. In the Qaidam Basin, the lakes have expanded in surface area and there has been a noticeable increase in vegetation coverage. Collectively, these indicators unambiguously show that the Qaidam Basin is undergoing a process of increased moisture levels. Thus, it can be deduced that the modern Qaidam Basin is both experiencing warming and becoming wet. [ABSTRACT FROM AUTHOR]