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Sleep problems among frontline medical staff during the COVID-19 epidemic require attention. A total of 249 frontline medical staff who were recruited to support Wuhan completed this cross-sectional study. A web-based questionnaire about insomnia, depression, anxiety, and fatigue was used to assess mental health status. The prevalence of sleep disorders among frontline medical staff was 50.6%. More time spent in Wuhan and a history of insomnia, depression, anxiety, and fatigue were associated with a higher risk of insomnia. People who stayed in Wuhan for a long time with a history of insomnia, depression, anxiety, and fatigue symptoms might be at high risk of insomnia. [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]

A comprehensive and integrative view of East Asian monsoon evolution during the Holocene is still under debate, and additional high-resolution proxy records from climatically sensitive locations are requisite to solve this complex issue. In this paper, we present three well-dated mud/peat cores from a paleo-pingo depression in the Sanjiang Plain, a climatically sensitive region to monsoon variation, to reveal the paleoenvironmental history of the wetland and discuss the regional impacts from monsoon evolution. A paleolake developed in the study area before 5.5 ka BP, and a peatland initiated thereafter consequent upon the gradual shrinking of the paleolake. This transition lasted until 4.5 ka BP, when the paleolake changed entirely to a wetland. Considering the prevalent monsoon climate in the Sanjiang Plain, we suggest that the lake-to-wetland transition from 5.5 to 4.5 ka BP indicates a rapid decline of the East Asian summer monsoon in addition to autogenic basin infilling processes. Such a remarkable monsoon weakening event has been documented across northern China, and we associate this with ocean–atmosphere interactions throughout low-latitude regions. [ABSTRACT FROM AUTHOR]

Peatlands in the Sanjiang Plain could be more vulnerable to global warming because they are located at the southernmost boundary of northern peatlands. Unlike bacteria, fungi are often overlooked, even though they play important roles in substance circulation in the peatland ecosystems. Accordingly, it is imperative that we deepen our understanding of fungal community structure and diversity in the peatlands. In this study, high-throughput Illumina sequencing was used to study the fungal communities in three fens in the Sanjiang Plain, located at the southern edge of northern peatlands. Peat soil was collected from the three fens which developed during different periods. A total of 463,198 fungal ITS sequences were obtained, and these sequences were classified into at least six phyla, 21 classes, more than 60 orders and over 200 genera. The fungal community structures were distinct in the three sites and were dominated by Ascomycota and Basidiomycota. However, there were no significant differences between these three fens in any α-diversity index (p > 0.05). Soil age and the carbon (C) accumulation rate, as well as total carbon (TC), total nitrogen (TN), C/N ratio, and bulk density were found to be closely related to the abundance of several dominant fungal taxa. We captured a rich fungal community and confirmed that the dominant taxa were those which were frequently detected in other northern peatlands. Soil age and the C accumulation rate were found to play important roles in shaping the fungal community structure. [ABSTRACT FROM AUTHOR]

The highly glycosylated bone sialoprotein (BSP) is an abundant non-collagenous phosphoprotein in bone which enhances osteoblast differentiation and new bone deposition in vitro and in vivo. However, the structural details of its different glycosylation linkages have not been well studied and their functions in bone homeostasis are not clear. Previous studies suggested that the O -glycans, but not the N -glycans on BSP, are highly sialylated. Herein, we employed tandem mass spectrometry (MS/MS) to demonstrate that the N -glycanson the recombinant human integrin binding sialoprotein (rhiBSP) are also enriched in sialic acids (SAs) at their termini. We also identified multiple novel sites of N -glycan modification. Treatment of rhiBSP enhances osteoblast differentiation and mineralization of MC3T3-E1 cells and this effect could be partially reversed by efficient enzymatic removal of its N -glycans. Removal of all terminal SAs has a greater effect in reversing the effect of rhiBSP on osteogenesis, especially on mineralization, suggesting that sialylation at the termini of both N -glycans and O -glycans plays an important role in this regulation. Moreover, BSP-conjugated SAs may affect mineralization via ERK activation of VDR expression. Collectively, our results identified novel N -glycans enriched in SAs on the rhiBSP and demonstrated that SAs at both N - and O -glycans are important for BSP regulation of osteoblast differentiation and mineralization in vitro. [ABSTRACT FROM AUTHOR]

Understanding the response of wetlands to climate changes could provide useful insights toward predicting the wetlands future in a warmer world. Here, we present a well-dated peat/mud profile with multiple proxies to reconstruct the historic development of Honghe wetland and discuss its response to the East Asian monsoon variations during the Holocene. The results show that the Honghe wetland developed as a shallow-water lake in the mid-early Holocene during a time of high precipitation from the East Asian monsoon. At 4600 years BP, peat layers appeared with sharp increases in the accumulation rate, grain-size Md and arboreal plants, marking a decline in water levels with the relative dry climate. Moreover, the transition corresponds well to the mid-Holocne monsoon weakening event and we suggest the decrease of the monsoon associated precipitation plays a critical role in driving the lake-peatland transition in Honghe. Facing the intensified summer monsoon in future, we suggest some practical measures should be taken to protect the present wetlands from changing back to lakes. [ABSTRACT FROM AUTHOR]

[Display omitted] • The bacterial variation within microhabitats associated with the black stone of the Black Gobi desert were investigated. • Bacterial communities within microhabitats were highly different in the desert ecosystems. • Microhabitats formed by black stones support highly diverse and biologically active bacterial communities. • Major environmental controls were water content, total carbon, and total nitrogen. Desert soil around the black stones is highly complex, which substantially affects the diversity and composition of inhabiting microbes. The existence of black stones in the southern part of the Black Gobi desert of China could provide microhabitats for diverse bacterial communities that remain unexplored. Hence, Illumina MiSeq sequencing was used to determine the differences in bacterial communities associated within microhabitats in three sites of the Black Gobi desert, China. Our results show that bacterial communities are significantly affected by each microhabitat. For instance, the α -diversity of bacterial communities indicated more remarkable diversity and richness in these microhabitats. Considering β -diversity, variances were reported mainly in the Proteobacteria (30%), Actinobacteria (26%), Chloroflexi (19%), and Firmicutes (9%). Firmicutes were markedly enriched in the upper surface, especially in site 1. Compared to other microhabitats, the relative abundance of Proteobacteria was greater in the subsurface, and they were also more dominant in the other two sites. Network analysis of soil factors and bacterial genera showed that the most significant-occurrences were positively correlated, demonstrating potential synergistic interactions. Collective with the predicted function profiles and the redundancy analysis, these results indicated the highest variances in bacterial community structure and function in Black Gobi Desert ecosystems. These differences are likely closely related to the soil parameters, mainly water content, total carbon, and total nitrogen, and might be associated with black stones. This study concludes that microhabitats formed by black stones support highly diverse and biologically active bacterial communities. These microhabitats with extreme environmental conditions deliver new opportunities to explore soil bacterial communities at relevant spatial scales in the Black Gobi desert. [ABSTRACT FROM AUTHOR]

Understanding the fire evolution history and its driving mechanisms can provide useful insights into the fire regimes and their potential impacts in the future. Here, we present a well-dated peat profile with high-resolution charcoal and pollen records to reconstruct the fire and vegetation history in the Sanjiang Plain over the last 6000 yr. The regional and local fire frequencies were reconstructed with the microscopic (< 125 μm) and macroscopic (> 125 μm) charcoal fractions, respectively. During the interval ~ 6.0–4.5 ka BP, both the regional and local fires exhibited much low frequencies responding to the strong summer monsoon. Thereafter, the fire frequencies increased significantly with the decline of the summer monsoon, and the highest frequencies corresponded well with the weak monsoon intervals around 4.0, 2.7, and 0.8 ka BP. As for the local fires, in addition to the climate changes, the local vegetation conditions have also served an important role in driving their occurrences. During the last 300 yr, the gradually increased fire frequencies were attributed to the intensified human activities instead of the climate and vegetation influences. [ABSTRACT FROM AUTHOR]

Background: To study the feasibility and efficacy of antibiotic cement in preserving endoplants after infection in patients with early tibial plateau fracture on plate exposure. Patients and Methods: A retrospective analysis of 23 patients treated for post-operative infection with plate exposure after tibial plateau fracture between 2017 and 2021. They were divided into the observation group (10 patients) and the control group (13 patients). Total operation time, length of hospitalization, hospitalization cost, the number of surgeries, white blood cell (WBC) count, neutrophil (NEUT) count, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), the post-operative evaluation index, and complications were observed during the follow-up period. Results: All patients were followed up for 6 to 12 months; wound healing was observed in both groups. The total operation time for patients in the control group was longer compared with the observation group. However, the length of hospitalization, hospitalization cost, and number of surgeries in the observation group were less compared with the control group. No difference in WBC, NEUT, ESR, and CRP levels was observed one day after surgery. Furthermore, WBC, NEUT, ESR, and CRP levels were higher in patients in the control group compared with the observation group 72 hours after surgery. There were no differences in the post-operative evaluation index and complications in both groups. Conclusions: The antibiotic cement coating used for treating early post-operative infection in patients with tibial plateau fracture could effectively control infection while retaining endoplant, thereby promoting wound healing. It could also reduce pain and the medical burden on patients. [ABSTRACT FROM AUTHOR]

Fucoidans are complex sulfated polysaccharides extracted from brown algae. Depending on the concentration, they have been shown to stimulate and inhibit blood coagulation in vitro . Promotion of coagulation is mediated by blocking tissue factor pathway inhibitor (TFPI). We screened fucoidan extracts from four brown algae species in vitro with respect to their potential to improve coagulation in bleeding disorders. The fucoidans’ pro- and anticoagulant activities were assessed by global hemostatic and standard clotting assays. Results showed that fucoidans improved coagulation parameters. Some fucoidans also activated the contact pathway of coagulation, an undesired property reported for sulfated glycosaminoglycans. Chemical evaluation of fucoidans’ complex and variable structure included molecular weight ( Mw ), polydispersity (polyD), structural heterogeneity, and organic and inorganic impurities. Herewith, we describe a screening strategy that facilitates the identification of crude fucoidan extracts with desired biological and structural properties for improvement of compromised coagulation like in hemophilia. [ABSTRACT FROM AUTHOR]

Compared to the well-studied the grain-size depositional process in hydraulic and aeolian sediments, the process in wetlands is still poorly understood. In this study, the grain-size components of a well-dated mud/peat profile (SJ2) in the Sanjiang Plain were partitioned using a lognormal distribution function. The results suggest that the lacustrine deposits contain four distinct unimodal grain-size distributions, C-1 through C-4, with their modal sizes ranging 0.7–1.6, 2.4–8.7, 15.7–27.8, and 380.2–529.6 μm respectively. Only the C-1 and C-3 were identified in the peat layers. A grain-size depositional modal was introduced to explain the environmental meanings of the four components. C-3, as a nearshore suspension component, was the most sensitive component to the variation of local hydraulic conditions. Based on the variation of C-3 percentages of the profile SJ2, the local hydraulic conditions were tentatively reconstructed, and the results showed a close relation with the monsoon variations during the Holocene. Accordingly, we suggest the relative coarse component of the polymodal peat deposits in monsoonal regions can be used as a sensitive indicator for the hydraulic conditions and the monsoon circulations in the geological past. [ABSTRACT FROM AUTHOR]

Monosaccharide analysis is a critical way to profile the composition of complex carbohydrates. Methods to analyze neutral and amino sugars have been established for a long time, but methods for acidic sugars are rare. The acidic sugars, including uronic acids and sialic acids, are also important components in some complex carbohydrates. In this report, a high-performance anion-exchange chromatography method with pulsed amperometric detection was initially developed to analyze acidic sugars including different uronic acids and sialic acids. Subsequently, a method to profile complete monosaccharides, including most neutral, amino, and acidic sugars, was developed. This method has a limit of quantitation of ~12.5 × 10-3 nmol for each sugar as well as good linearity over a wide range. This is a convenient procedure because it avoids additional derivatization of monosaccharides and has a broad application to a wide range of complex carbohydrates. The monosaccharide compositions of a variety of complex carbohydrates such as different glycosaminoglycans, alginate, fucoidan, and glycans were profiled by this comprehensive method. In addition, the hydrolysis patterns of these complex carbohydrates are discussed. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, we report 3780-m-thick Neogene deposits accumulated in the Kuqa foreland basin of southern Tianshan range, providing great potential for studying both tectonics and paleoclimatic changes. Based on palynological evidence, we discuss the paleoenvironmental changes as well as the interplay between regional uplift and climatic change in the region studied. Our results indicate that the vegetation and climatic changes from 13.3 to 7Ma were response to global climatic changes. After 7Ma, the uplift of the southern Tianshan range partially affects vegetation and climatic changes. Both global cooling and the rainshadow effect of uplifted high mountains affect the enhanced arid climate initiated ca. 5.23Ma ago. Such climatic changes are important archives in reconstructing paleoclimate of the Asian interior. [ABSTRACT FROM AUTHOR]

Abstract: Chondroitin sulfate (CS) has an important role in cell division, in the central nervous system, and in joint-related pathologies such as osteoarthritis. Due to the complex chemical structure and biological importance of CS, simple, sensitive, high resolution, and robust analytical methods are needed for the analysis of CS disaccharides and oligosaccharides. An ion-pairing, reversed-phase, ultraperformance liquid chromatography (IPRP–UPLC) separation, coupled to electrospray ionization mass spectrometry with an ion trap mass analyzer, was applied for the analyses of CS-derived disaccharides. UPLC separation technology uses small particle diameter, short column length, and elevated column temperature to obtain high resolution and sensitivity. Hexylamine (15mM) was selected as the optimal ion-pairing reagent. [Copyright &y& Elsevier]

Heparin is a widely used anticoagulant and antithrombotic agent. Recently, a contaminant, oversulfated chondroitin sulfate (OSCS), was discovered within heparin preparations. The presence of OSCS within heparin likely led to clinical manifestations, most prevalently, hypotension and abdominal pain leading to the deaths of several dozens of patients. Given the biological effects of OSCS, one continuing item of concern is the ability for existing methods to identify other persulfonated polysaccharide compounds that would also have anticoagulant activity and would likely elicit a similar activation of the contact system. To complete a more extensive analysis of the ability for NMR and capillary electrophoresis (CE) to capture a broader array of potential contaminants within heparin, we completed a systematic study of NMR. both monoand bidimensional, and CE to detect both various components of sidestream heparin and their persulfonated derivatives. We show that given the complexity of heparin samples, and the requirement to ensure their purity and safety, use of orthogonal analytical techniques is effective at detecting an array of potential contaminants that could be present. [ABSTRACT FROM AUTHOR]

Abstract: The novel low-molecular-weight chitosan polysulfate (MW 5120–26,200Da) was prepared using the depolymerization of chitosan with papain (EC. 3.4.22.2). The sulfonation of depolymerized products was performed using chlorosulfonic acid in N,N-dimethylformamide under semi-heterogeneous conditions. The structures of the products were characterized by FTIR, 13C NMR, and 1H NMR (1D, 2D NMR) spectroscopy. The present study sheds light on the mechanism of anticoagulant activity of chitosan polysulfate. Anticoagulant activity was investigated by an activated partial thromboplastin assay, a thrombin time assay, a prothrombin time assay, and thrombelastography. Surface plasmon resonance also provided valuable data for understanding the relationship between the molecular binding of sulfated chitosan to two important blood clotting regulators, antithrombin III and heparin cofactor II. These results show that the principal mechanism by which this chitosan polysulfate exhibits anticoagulant activity is mediated through heparin cofactor II and is dependent on polysaccharide molecular weight. [Copyright &y& Elsevier]

Thin layer chromatography (TLC) is routinely used by synthetic organic chemists and natural products chemists working on a variety of types of molecules. Carbohydrate chemists and biochemists in the past largely relied on paper chromatography for rapid and inexpensive analysis. Carbohydrates are highly polar molecules and often require derivatization to be analyzed by TLC. Acidic carbohydrates pose an even more difficult challenge as they contain a formal negative charge and counterion, and can interact with commonly used stationary phases. This review describes TLC methods that have been developed for the analysis of acidic monosaccharides, disaccharides, and oligosaccharides derived from natural sources. [ABSTRACT FROM AUTHOR]

Abstract: Liquid chromatography–mass spectrometry was applied to determine the action pattern of different chondroitin lyases. Two commercial enzymes, chondroitinase ABC (Proteus vulgaris) and chondroitinase ACII (Arthrobacter aurescens), having action patterns previously determined by viscosimetry and gel electrophoresis were first examined. Next, the action patterns of recombinant lyases, chondroitinase ABC from Bacteroides thetaiotaomicron (expressed in Escherichia coli) and chondroitinase AC from Flavobacterium heparinum (expressed in its original host), were examined. Chondroitin sulfate A (CS-A, also known as chondroitin-4-sulfate) was used as the substrate for these four lyases. Aliquots taken at various time points were analyzed. The products of chondroitinase ABC (P. vulgaris) and chondroitinase AC (F. heparinum) contained unsaturated oligosaccharides of sizes ranging from disaccharide to decasaccharide, demonstrating that both are endolytic enzymes. The products afforded by chondroitinase ABC (B. thetaiotaomicron) and chondroitinase ACII (A. aurescens) contained primarily unsaturated disaccharide. These two exolytic enzymes showed different minor products, suggesting some subtle specificity differences between the actions of these two exolytic lyases on chondroitin sulfate A. [Copyright &y& Elsevier]

Abstract: Propagation of faults and folds in the foreland basins of Tian Shan is an important process accommodating Cenozoic crustal shortening and mountain building, but little is known about the accurate time of the Cenozoic tectonic deformation. Based on growth strata and age determination, we show that syntectonic growth strata began to develop in the middle part of Tian Shan since 6 Ma ago. Geometry analysis indicates that formation of the growth strata is associated with progressive fold-limb rotation. Formation of the growth strata is contemporaneous with the tectonic deformation in the thrusting and folding zones. Together with the remarkable increase of sedimentation rate as well as the accumulation of coarse molasse deposits, we conclude that the late Cenozoic crustal shortening and mountain building in the region initiated since about 6 Ma and lasted to the early Pleistocene, as a consequence of intracontinental deformation within the India–Eurasia convergent system. [Copyright &y& Elsevier]

Abstract: Thick Cenozoic deposits were shed into the foreland basin of the Tian Shan Range, providing great potential for understanding the relationship between tectonic history and paleoclimatic changes. In the present study, we compiled a pollen record for the interval 26.5–2.6 Ma based on a palynological analysis of a latest Oligocene–Pliocene stratigraphic sequence in the northern foreland basin of the Tian Shan. Our results indicate that a remarkable warm climate occurred at ca. 18–15 Ma ago, corresponding to the Mid-Miocene Climatic Optimum, while a change to an arid climate occurred at 6 Ma, marked by an increase in the drought-tolerant herb taxa Artemisia and Chenopodiaceae. This latter change was coincident with the late Cenozoic climatic deterioration recorded at high latitudes in the Northern Hemisphere. These inferred climatic events are further supported by the results of principal component analysis of the pollen data, such records are important archives in reconstructing the paleoclimate of the Asian interior. [Copyright &y& Elsevier]

Understanding the historical flooding regime and its driving mechanisms provide useful insights into prediction of disasters in future. In this study, the paleo-flooding activities along the upper Amur River Delta were reconstructed based on the grain-size dataset of three sedimentary cores along a 120-km transect from its alluvial valley. Our results indicate that the coarse sand fraction in marshes surrounding the upper Amur River Delta is closely linked to historical flooding activities. Six "busy" flooding periods were identified at 4.4–4.0 ka BP, 3.6–3.2 ka BP, 1.7–1.4 ka BP, 1.1–0.9 ka BP, 0.7–0.5 ka BP, and 0.2–0 ka BP, respectively. These flooding intervals correspond well to other sedimentary flooding records from the East Asia Summer Monsoon (EASM) domain, and are in-line with the strengthened EASM stages throughout the Late-Holocene. Thus, our dataset suggests that the EASM circulation, especially its associated precipitation, has played a critical role in the evolution of flooding regime during the Late-Holocene epoch in the Amur River Delta. The last 0.2 ka BP is an exception as the coarse sand accumulation rate increased significantly while the EASM precipitation shows no equivalent shift. The increased coarse sand signals were likely attributed to floods induced by human interference instead of the long-term climate influence. [Display omitted] • The coarse sand fraction in marshes surrounding the Amur River is closely linked to historical flooding activities. • Six "busy" flooding periods were identified at 4.4-4.0, 3.6-3.2, 1.7-1.4, 1.1-0.9, 0.7-0.5, and 0.2-0 ka BP. • The Historical flooding activities in our study region were primarily controlled by EASM associated precipitation. • The flooding-rich period over the last 200 years was ascribed to human disturbance. [ABSTRACT FROM AUTHOR]

Isobaric oligosaccharides enzymatically prepared from hyaluronic acid (HA) and N-acetylheparosan (NAH), were distinguished using tandem mass spectrometry. The only difference between the two series of oligosaccharides was the linkage pattern (in HA 1→3 and in NAH 1→4) between glucuronic acid and N-acetylglucosamine residues. Tandem mass spectrometry afforded spectra in which glycosidic cleavage fragment ions were observed for both HA and NAH oligosaccharides. Cross-ring cleavage ions 0,2An and 0,2An-h (n is even number) were observed only in GlcNAc residues of NAH oligosaccharides. One exception was an 0,2A2 ion fragment observed for the disaccharide from HA. These cross-ring cleavage fragment ions are useful to definitively distinguish HA and NAH oligosaccharides. [Copyright &y& Elsevier]

Abstract: A sensitive and selective liquid chromatographic–tandem mass spectrometric (LC–MS/MS) method was developed for the determination of serial chiral novel anticholinergic compounds of phencynonate in rat plasma. After a simple protein-precipitation using methanol, the post-treatment samples were separated on a CAPCELL UG120 column with a mobile phase of a mixture of methanol and water (35:65) containing 0.1% formic acid. The serial chiral analytes and internal standard (IS) were all detected by the use of selected reaction monitoring mode (SRM). The method of all serial chiral analytes developed was validated in rat plasma with a daily working range of 0.5–100ng/ml with correlation coefficient, R 2 ≥0.99 and a sensitivity of 0.5ng/ml as lower limit of quantification, respectively. This method was fully validated for the accuracy, precision and stability studies for all serial chiral analytes. The method proved to be accurate and specific, and was applied to the pharmacokinetic study of serial chiral novel anticholinergic compounds of phencynonate in rat plasma. [Copyright &y& Elsevier]

Negative-ion electrospray tandem mass spectrometry (ES-MS/MS) with collision-induced dissociation (CID) is attempted for sequence determination of alginate oligosaccharides, derived from polyanionic alginic acid, polymannuronate, and polyguluronate by partial depolymerization using either alginate lyase or mild acid hydrolysis. Sixteen homo- and hetero-oligomeric fragments were obtained after fractionation by gel-filtration and strong anion exchange high performance liquid chromatography. The product-ion spectra of these alginate oligosaccharides were dominated by intense B-, C-, Y-, and Z-type ions together with 0,2A- and 2,5A-ions of lower intensities. Internal mannuronate residues (M) produce weak but specific decarboxylated Zint-ions (Zint − 44 Da; int: denotes internal), which can be used for distinction of M and a guluronate residue (G) at an internal position. A reducing terminal M or G, although neither gives rise to a specific ion, can be identified by differences in the intensity ratio of fragment ions of the reducing terminal residue [2,5Ared]/[0,4Ared] (red: denotes reducing terminal). [Copyright &y& Elsevier]

Alginate that was purified from the fermentation solution of marine bacteria Vibro sp. 510 under specific reaction conditions was hydrolyzed by alginate lyase. Seven oligosaccharides, including di-, tri- and tetrasaccharides, were isolated through low-pressure, gel-permeation chromatography (LP-GPC) and semipreparative strong-anion exchange (SAX) fast-protein liquid chromatography (FPLC). The oligosaccharide structures were elucidated based on ESIMS and 2D NMR spectral analysis. The hydrolytic specificity of this alginate lyase to alginate is discussed. [Copyright &y& Elsevier]

Schematic figure showing climate driving mechanisms on wetland hydrological and vegetational evolution. The relatively strong East Asian summer monsoon (EASM) with high precipitation tends to generate a higher water-level condition with more hygrophilous herbaceous plants while blocking the deposition of coarse grain-size fractions (a), and vise versa for weak EASM stages (b). [Display omitted] • The late-Holocene hydrological and vegetational regimes were reconstructed. • An ecological lake-to-wetland transition occurred at ~4.5 ka BP. • The wetlands evolution was largely controlled by monsoonal precipitation. The responding mechanism of wetland ecosystem to climate change is currently unclear due to a lack of long-term records incorporating multiple ecological factors. This paper presents a well-dated and multi-proxy cored record from a natural freshwater wetland developed in a paleo-pingo-related depression on the Sanjiang Plain. The study aims to reconstruct the wetland water-level and vegetational regimes during the past ~6.0 ka BP and discuss the wetland evolution response to the East Asian summer monsoon (EASM) circulation. The results show that a shallow-water lake with hygrophilous herbs developed in the depression with a strong EASM during ~6.0–4.5 ka BP. The paleolake was succeeded by a wetland with a lowered mean water level and an increase in tree cover controlled by the weakened EASM during the past 4.5 ka BP. Such an ecological lake-to-wetland transition corresponds well to the sharp decline of the EASM around 4.5 ka BP which has been well documented in various geological records across the EASM domain. During the wetland developing stage over the past 4.5 ka BP, the water-level and vegetational changes in the studied depression were also closely related to the EASM variations. The strengthened EASM usually generated higher water levels with more hygrophilous herbs around 4.0 ka BP, 3.5 ka BP, 3.0 ka BP, 2.0 ka BP, and 1.3 ka BP. Considering the prevalent EASM climate serving as the predominant water supply for the wetlands on the modern Sanjiang Plain, we suggest the EASM circulation has played a critical role in driving the wetland ecological evolution during the mid-to-late Holocene Epoch. The past 0.4 ka BP is an exception as the local Trees/Herbs ratio visibly increased with the declined water level, while the monsoonal precipitation shows no equivalent shift. The wetland evolution at this stage was attributed to human interference. [ABSTRACT FROM AUTHOR]

The chloride content is a critical factor influencing the corrosion of steel fibers in concrete. This study focused on the corrosion behaviors of steel fibers exposed to simulated concrete pore solutions with different chloride contents. The corrosion rates of the steel fibers were calculated based on the changes in the diameter and ultimate tensile load. The electrochemical parameters for the corrosion of the steel fibers were continuously monitored for 62 days. In addition, the surface micromorphologies of the corroded steel fibers were observed using scanning electron microscopy (SEM). The results showed that based on the change in the diameter, the corrosion rate of the steel fibers increased almost linearly when the NaCl content in the simulated solution increased from 2% to 5%. However, based on the variation of the ultimate tensile load, the corrosion ratio of the steel fibers increased linearly with the increase in the exposure time when the NaCl content was less than 3%, while it increased exponentially when the NaCl content exceeded 3%. According to the open circuit potential, Tafel polarization curves, and electrochemical impedance spectroscopy (EIS), the corrosion tendency and corrosion rates of the steel fibers exposed to the simulated solutions increased significantly when the NaCl content increased from 2% to 5%. Additionally, the corrosion damage on the surfaces of the steel fibers increased notably, and after 180 days of exposure to the simulated solution with 5% NaCl, the steel fiber was almost broken. These findings will help to understand the durability of SFRC in a chloride environment. [ABSTRACT FROM AUTHOR]

As a kind of Fabry-Perot cavities, one-dimensional photonic crystals (1DPCs) with defect layers have been widely utilized for narrow-band filtering. However, according to the Bragg interference condition, photonic band gaps (PBGs) in conventional all-dielectric 1DPCs shift towards shorter wavelengths (blueshift) as the incident angle increases. Therefore, transmittance peaks in all-dielectric one-dimensional defective PCs also shift along with PBGs as the incident angle increases. Recently, the emergence of angle-insensitive PBGs in 1DPCs containing hyperbolic metamaterials (HMMs) provides us a possibility to realize omnidirectional narrow-band filtering. In this paper, we design an angle-insensitive ultraviolet PBG in a 1DPC containing HMM, where HMM layer is mimicked by a subwavelength dielectric-metal multilayer. By introducing a defect layer into the 1DPC and adjusting the dielectric thickness within the 1DPC, we achieve omnidirectional narrow-band ultraviolet filtering with angle-insensitive property. This omnidirectional narrow-band filtering might possess applications in digital display, organic solar cell and wavelength division demultiplexing. [ABSTRACT FROM AUTHOR]

This work aims to investigate the effect of additional flue gas desulfurization gypsum (FGDG) on the properties of calcium sulfoaluminate cement (CSAC) blended with ground granulated blast furnace slag (GGBFS). The hydration rate, setting time, mechanical strength, pore structure and hydration products of the CSAC-GGBFS mixture containing FGDG were investigated systematically. The results show that the addition of FGDG promotes the hydration of the CSAC-GGBFS mixture and improves its mechanical strength; however, the FGDG content should not exceed 6%. [ABSTRACT FROM AUTHOR]

An integrated view of wetland's evolution is currently poorly understood due to a lack of knowledge on long-term interactions of multiple ecological factors. Here, we present a cored palynological record covering the Holocene Epoch from a depressional wetland on Heixiazi Island (China). With the aid of principal component analysis and cluster analysis of the palynological data, the historical vegetation regime has been well reconstructed for wetlands on the island. With further assistance from the published data on local hydrology and regional East Asian summer monsoon (EASM) variations, the interactions of vegetation, hydrology, and climate in the island's wetlands have been thoroughly analyzed with correlation analysis of the three factors. The results indicate that a strong EASM generally led to a high water level in the wetlands from increased monsoonal precipitation, causing an increase in arboreal vegetation and a decrease in herbs. Alternatively, a weak EASM generally led to low water levels due to decreased monsoonal precipitation, causing a decrease in arboreal vegetation and an increase in herbs. The local vegetation regime during the early Holocene was marked by an increase in tree/herb ratio due to rising water levels under the influence of an increasingly strengthened EASM. Subsequently, a general decline of the tree/herb ratio occurred from a gradual decrease in water level during the mid and late Holocene when the EASM gradually retreated. The wettest stage marked by the highest water level and tree/herb ratio occurred 8.0–4.6 ka BP with the strongest EASM. The driest stage occurred during the last 0.4 ka BP, which was attributed to both the weakest EASM influence and anthropogenic disturbance. Our study provides an integrated view of the wetlands' ecological dynamics incorporating multi-factor interactions, which further sheds light on the EASM driving mechanisms on wetlands evolution during the Holocene Epoch. Schematic figure showing the historical interactions of vegetation, hydrology, and climate in a typical wetland on Heixiazi Island, NE China. The relatively strong East Asian summer monsoon (EASM) with high atmospheric precipitation tends to generate a higher water level with less herbaceous plants (a), while a weaker EASM stage with less precipitation leads to a lower water level and more herbaceous plants (b). The light blue and gray arrows indicate the separate pollen contributions of arboreal trees in elevated areas and herbs within the depressional wetland, respectively. Unlabelled Image • A palynological methodology aided in reconstructing vegetation history. • Holocene climatological and hydrological regimes were determined. • Holocene interactions of vegetation, hydrology, and climate were presented. • Wetland evolution was largely controlled by monsoonal precipitation. [ABSTRACT FROM AUTHOR]

Abstract: Traditional chromatographic quantification methods for heparosan produced from the Escherichia coli K5 strain rely on extensive purification requiring laborious sample preparation. These methods are time-consuming, often resulting in sample loss during purification, and thus might not accurately reflect the amount of heparosan in the original mixture. A simple, sensitive 1H nuclear magnetic resonance (NMR) quantification method that directly quantifies heparosan K5 polysaccharide present in E. coli fermentation supernatant is described. [Copyright &y& Elsevier]

A novel homogenous polysaccharide LPWF together with its three acid hydrolysis products LPWF1–3 were isolated and prepared from lotus plumule (germs of Nelumbo nucifera). LPWF was composed of rhamnose (Rha), arabinose (Ara), galactose (Gal), xylose (Xyl), and galacturonic acid (GalA) in the molar ratio of 7.3: 34.0: 7.0: 19.1: 32.6 with a molecular weight of 567.6 kDa. The structure of LPWF was elucidated by methylation and NMR analysis of LPWF1–3 and a follow-up structural assembling aided by high-resolution mass spectrometry mapping of oligosaccharides and ROSEY spectra. LPWF was characterized as an unusual pectin linked by rhamnogalacturonan I (RGI, composed of LPWF1–2) and xylogalacturonan (XGA, LPWF3). LPWF1 was an arabinan peeled from the RGI part with a 1,5-linked backbone branching on the O -2 position, while LPWF2 was the remaining part of RGI composed of Rha (36.1%), Gal (17.8%), and GalA (43.7%). LPWF3 was identified as the XGA part with a backbone of α-1,4-linked GalA and branches of mono-xylose substitutions on the O -3 of GalA. LPWF (25 μg/mL) demonstrated significant inhibitions on the expression of IL-1β, IL-6, and TNF-α in LPS-stimulated primary murine microglia cultures. LPWF1 and 2 showed selectively and significantly inhibitory activity against the expression of IL-1β. • Structure features of the pectin LPWF was determined by NMR and methylation. • Structural characterization of LPWF was elucidated by assembling three stepwise hydrolyzed fragments. • LPWF is speculated to be a linearly linked RGI and XGA pectin. • The pectin LPWF could significantly inhibit the expression of IL-1β, IL-6, and TNF-α. [ABSTRACT FROM AUTHOR]

Background: Wrist fracture is one of the common limb fractures. Its incidence rate increases with age and osteoporosis. Nowadays, Sleep health is increasingly valued, but the relationship between wrist fractures and sleep time is not yet clear. Methods: Data in this study were collected and screened from the NHANES from 2005 to 2010 and 2013 to 2014. The variables were extracted from interviews and compared between the wrist fractures and the sleep duration. The data was analyzed by weighted multivariate logistic regression. Results: After excluding individuals who were not eligible and had invalid data, we finally identified 1835 participants for inclusion in this study. We found a negative association between the sleep duration and the fractured of the wrist (OR = 1.027,95% CI (1.027, 1.028), P < 0.00001). Conclusion: This study demons that the association between the sleep duration and the fractures of the wrist is significant. Our findings provide a better understanding of the relationship between sleep duration and wrist fractures. This study may help us reducing the incidence of wrist fractures in the population based on healthy sleep management in the future, and improve the quality of life of middle-aged and elderly patients. Provide evidence for clinical patients to manage healthy sleep. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the chiral inversion and the stereoselective pharmacokinetic profiles of desmethyl‐phencynonate hydrochloride after administration of the single isomer and its racemate to beagle dogs. A liquid chromatography with tandem mass spectrometry (LC–MS/MS) method was established for determination of the stereoisomers on chiral columns in beagle dog plasma, which met all the requirements. The chiral inversion in dogs of the desmethyl‐phencynonate hydrochloride were studied after administration of the single isomer or the racemic modification. The stereoselective pharmacokinetic profiles of the desmethyl‐phencynonate hydrochloride were studied by assays for simultaneous isomers after administration of the racemic modification. The results showed that the absorption of the R-configuration dosed as the single isomer was higher than it dosed as the racemic modification. The AUC(0‐t), AUC(0‐∞), and Cmax of the S-configuration were much higher than those of R-configuration after oral administration of the racemic desmethyl‐phencynonate hydrochloride. The chiral inversion of desmethyl‐phencynonate isomers could not occur in dogs after administration of the R-configuration. [ABSTRACT FROM AUTHOR]

This study investigated the effect of alkalis on C3S hydration with and without incorporating aluminate phases. Pastes of 100% C3S and 90% C3S+10% metakaolin (MK) were prepared at 1%, 2%, and 3% Na2O content. X-ray diffraction (XRD) and thermogravimetric analysis (TGA) were used to characterize the solid phase assemblages, and then the hydration degree of C3S. Inductively coupled plasma optical emission spectroscopy (ICP-OES) was used to analyze the aqueous composition of pore solution. Mercury intrusion porosimetry (MIP) was used to measure the porosity of the hydrated pastes. The results highlighted the promoting effect of Na and the inhibiting effect of Al in pore solution on C3S hydration after a period of curing (90 days). Without incorporating metakaolin, the hydration degree of C3S continuously increased with the increase of Na concentration. Incorporating metakaolin into C3S can generate aluminate hydrates (carboaluminates, in this study), and the increased Na concentration can increase the dissolution or instability of carboaluminates and elevate the equilibrium Al concentration. Under this condition, the hydration degree of C3S fluctuated depending on the combined effect of Na and Al concentrations in pore solution on C3S hydration. [ABSTRACT FROM AUTHOR]

Background: The soil microbiome drives soil ecosystem function, and soil microbial functionality is directly linked to interactions between microbes and the soil environment. However, the context-dependent interactions in the soil microbiome remain largely unknown. Results: Using latent variable models (LVMs), we disentangle the biotic and abiotic interactions of soil bacteria, fungi and environmental factors using the Qinghai-Tibetan Plateau soil ecosystem as a model. Our results show that soil bacteria and fungi not only interact with each other but also shift from competition to facilitation or vice versa depending on environmental variation; that is, the nature of their interactions is context-dependent. Conclusions: Overall, elevation is the environmental gradient that most promotes facilitative interactions among microbes but is not a major driver of soil microbial community composition, as evidenced by variance partitioning. The larger the tolerance of a microbe to a specific environmental gradient, the lesser likely it is to interact with other soil microbes, which suggests that facilitation does not necessarily lead to niche expansion. [ABSTRACT FROM AUTHOR]

As a major plant‐derived soil organic carbon (SOC) component, lignin phenols are unique biomarkers that reflect biogeochemical characteristics under different vegetation compositions and climatic zones in coastal wetlands. However, the latitudinal patterns of plant‐derived lignin phenols to SOC and their link with the stability and controlling mechanisms remain poorly understood.A total of 156 soil samples from 39 sites along a 5000 km coastal transect, were taken to explore the effects of biological and environmental controls on the patterns of lignin phenols. Lignin phenols had contents ranging from 1.91 to 83.3 mg g−1 OC, and a positive correlation was detected in grass‐dominated salt marsh, but a weakly negative correlation in mangrove. Positive correlations between SOC or lignin content and C/V or S/V (the cinnamyl‐ or syringyl‐to‐vanillyl) ratios were found, while overall negative correlations between SOC or lignin content and (Ad/Al)V or (Ad/Al)S (the acid‐to‐aldehyde of vanillyl or syringyl units) ratios were detected, respectively, which confirmed the validity of these lignin biomarker degradation parameters.Our findings revealed that plant C inputs and monomer ratios directly influenced the capacity of lignin phenols in soils. Lignin content and stabilization was mainly controlled by soil properties (i.e. pH, EC sand/clay). Mean annual temperature (MAT) influenced the patterns of lignin phenols both directly by increasing decomposition and indirectly by changing the vegetation and soil biogeochemistry (i.e. microbial substrate availability).Coastal wetlands are characterized by high primary productivity and C burial rate, yet plant‐derived lignin phenols are not as much as we thought compared to microbial residues C. Precise identification and quantification of the origin, decomposition, and determinants of lignin phenols help us understand their contribution to C sequestration and its response to climate and environmental changes. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

The corrosion of steel fibers is a direct cause of the deterioration of steel fiber-reinforced concrete in chloride environments. This study mainly investigated the corrosion behavior of steel fibers exposed to NaCl solutions with pH=7 , 10, 11, 12, and 13. The corrosion rate of the steel fibers was calculated according to the change of the diameter and ultimate tensile load. The electrochemical parameters of the steel fibers corrosion were continuously monitored. The morphology of the steel fibers affected by chloride attack was observed by scanning electron microscope (SEM). The results reveal that the corrosion rate of the steel fibers decreased as the pH of the NaCl solution increased from 7 to 13, and it was very small at pH≥12. According to the open circuit potential, corrosion potential, corrosion current density, and electrochemical impedance spectroscopy, the steel fibers exhibited a high corrosion tendency and corrosion rate when exposed to NaCl solutions with pH≤12. However, they exhibited low corrosion tendency in the chloride solution with pH=13. The surface roughness of the steel fibers exhibited only a slight increase after exposure to the NaCl solution with pH=13 for 180 days. [ABSTRACT FROM AUTHOR]

Heparin, an old but first-line anticoagulant, has been used over a century. It is a heterogeneous, linear, highly sulfated, anionic glycosaminoglycan with a broad distribution in relative molecular weight and charge density. These structural properties allow heparin to selectively interact with multiple proteins, leading to heparin's various pharmacological functions, such as anticoagulant, anti-viral, anti-tumor and anti-inflammatory activities. Clinical data suggest that unfractionated heparin or low molecule weight heparin could decrease mortality in COVID-19 patients with sepsis-induced hypercoagulation through the anticoagulant, anti-viral and anti-inflammatory activities of these drugs. Thus, the non-anticoagulant activity of heparin has again aroused attention. This review highlights recent advances in the preparation of heparin-derived drugs and clinical research on its non-anticoagulant properties over the past decade, to further the development and utilization of these important drugs. [Display omitted] [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]

• Soil water content (SWC) is determined as the outcomes of land use changes. • A significant correlation occurred between δ13C and δ15N values in wetlands, but underwent considerable changes after wetland conversion. • The shifts in organic matter sources over time and distinct mechanisms of degradation and preservation of SOM were underscore in wetlands following land use changes. Land use change in wetlands leads to significant losses of soil organic matter (SOM). Stable carbon (C) and nitrogen (N) isotopes offer insights into changes in C3/C4 vegetation, SOM sources, and decomposition processes. Yet, predicting the spatial–temporal dynamics of SOM contents and isotopes under land use changes remains challenging. This study delves into the effects of land use changes on soil organic carbon (SOC), total nitrogen (TN), δ13C and δ15N values, and soil physico-chemical properties and lignin phenols. Our results highlight the significance of soil water content (SWC) in determining the outcomes of land use changes. The conversion of wetland to cropland, forestland and construction land, led to notable reductions in SOC contents (8.71–56.33 %), and TN contents (7.87–37.12 %). Wetland conversion resulted in an enrichment of 13C and 15N abundance, with wetlands exhibiting the lowest δ13C (−25.57 to –22.89 ‰) and δ15N (2.66 to 6.67 ‰) values. A significant correlation occurred between δ13C and δ15N values in wetlands, but underwent considerable changes after wetland conversion. Key parameters, including bulk density (BD), C:N, the acid-to-aldehyde of vanillyl ((Ad/Al)v), lignin content (Λ 8), and total phosphorus (TP), were identified as influencing factors for both SOC and TN contents. When evaluating δ13C values, the most influential factors included silt, C:N, SOC, sand, and BD. These indicate the importance of soil chemical group (from 41 % to 21 %) in elucidating δ13C values declined, while lignin group's (from 9 % to 28 %) importance increased from topsoil to subsoil. The acid-to-aldehyde of syringyl ((Ad/Al)s), Λ 8 , C:N, BD and the cinnamyl-to-vanillyl ratio (C/V) were identified as the primary factors influencing δ15N values, with chemical group accounting for 36 % and lignin group for 48 % in topsoil, while physical group dominated 42 % in subsoil. Our findings underscore the shifts in SOM sources and distinct mechanisms of degradation/preservation of SOM following land use changes. [ABSTRACT FROM AUTHOR]

Anthocyanins in different types of black rice are different and their in vivo antioxidant activity is poorly studied. In this study, nine anthocyanins were detected by high performance liquid chromatography (HPLC) and eight of them were identified by ultra performance liquid chromatography/time-of-flight mass spectrometry (UPLC/Q-TOF-MS) in black rice. The in vivo antioxidant activity of the black rice extract containing 41.69% of anthocyanins was determined by the model of KBrO 3 -induced renal injury in mice. KBrO 3 caused serious renal injury, with a significant increase in serum creatinine (14.37 ± 0.27 μg/mL versus 8.80 ± 0.38 μg/mL) and blood urea nitrogen (BUN, 625.56 ± 42.62 mg/L versus 348.49 ± 14.90 mg/L) levels. KBrO 3 could also cause oxidative stress in the kidney, with a significant increase in renal xanthine oxidase (XOD), malondialdehyde (MDA) and nitric oxide (NO) levels. Pretreatment with the anthocyanin-rich black rice extract remarkably reduced the levels of serum creatinine and BUN and the levels of renal XOD, MDA and NO. The protective effects were due to the free radical scavenging capacity of the anthocyanins. [ABSTRACT FROM AUTHOR]

Licorice is known as "Gan-Cao" in traditional Chinese Medicine (TCM), belonging to the genus Glycyrrhiza (Family: Fabaceae/Leguminosae). It has a long medicinal history and wide applications in China. Polysaccharides of licorice (LPs) are one of the key bioactive components. As herbal polysaccharides attracted increasing interest in the past several decades, their extraction, isolation, structural characterization, pharmacological activities, and medicinal application have been explored extensively. It is worth heeding that the method of extraction and purification effects LPs, apart from specie and origin specificity. This review evaluates the method of extraction and purification and demonstrates its performance in gaining specific composition and its structure-activity relationship, which might lead the readers to a fresh horizon for developing advanced treatment strategies. It is recently reported that the conformation of LPs plays a vital role as biopolymers, such as selenized modification, microencapsulation, nanocomposite, liposome formulation, drug/hydrogel combinations, biosensor device, and synergistic effect with a vaccine. In addition, LPs showed a good thermodynamics profile, as these properties enable them to interact with additional supramolecular interaction by chemical modifications or copolymerization. Functional polymers that are responsive to various external stimuli, such as physical, chemical, and biological signals, are a promising study topic. Thus, LPs are emerging as a new biomaterial that can enhance intended formulation along exerting its inherent medicinal effects. It is hoped that this review will provide a basis for the utilization and further developments of licorice polysaccharides in the vast medium. [ABSTRACT FROM AUTHOR]

Abstract: The sulfo groups of glycosaminoglycans contribute to their high charge densities, and are critical for the role they play in various physiological and pathophysiological processes. Unfortunately, the sulfo groups can be hydrolyzed to inorganic sulfate. Thus, it is important to monitor the presence of these sulfo groups. In addition, free anions, including chloride, sulfate and acetate, are often present in glycosaminoglycans as a result of multiple purification steps, and their presence also needs to be monitored. In this report, ion chromatography with conductivity detection is used to analyze the anions present in glycosaminoglycans, including heparin, heparan sulfate, chondroitin sulfate and dermatan sulfate. This method allows quantitation over a wide range of concentrations, affording a limit of quantitation of 0.1ppm and a limit of detection of 0.05ppm for most anions of interest. The stability of heparin was also studied, providing data on the formation of both sulfate and acetate anions. [Copyright &y& Elsevier]