The use of multicomponent reactions in the development of bis-boronic acids for the detection of ß-sialic acid.

Sialic acid (SA) is a naturally occurring monosaccharide found in glycoproteins and glycolipids. Changes in the expression of SA are associated with several diseases; thus, the detection of SA is of great significance for biological research, cancer diagnosis, and treatment. Boronic acid analogs have emerged as a promising tool for detecting sugars such as SA due to its reversible covalent bonding ability. In this study, 11 bis-boronic acid compounds and 2 mono-boronic acid compounds were synthesized via a highly efficient Ugi-4CR strategy. The synthesized compounds were subjected to affinity fluorescence binding experiments to evaluate their binding capability to SA. Compound A1 was shown to have a promising binding constant of 2602 ± 100 M-1 at pH = 6.0. Density Functional Theory (DFT) calculations examining the binding modes between A1 and SA indicated that the position of the boronic acid functional group was strongly correlated with its interaction with SA's α-hydroxy acid unit. The DFT calculations were consistent with the observations from the fluorescence experiments, demonstrating that the number and relative positions of the boronic acid functional groups are critical factors in enhancing the binding affinity to SA. DFT calculations of both S and R configuration of A1 indicated that the effect of the S/R configuration of A1 on its binding with ß-sialic acid was insignificant as the Ugi-4CR generated racemic products. A fluorine atom was incorporated into the R2 substituent of A1 as an electron-withdrawing group to produce A5, which possessed a significantly higher capability to bind to SA (Keq = 7015 ± 5 M-1 at pH = 6.0). Finally, A1 and A5 were shown to possess exceptional binding selectivity toward ß-sialic acid under pH of 6.0 and 6.5 while preferring to bind with glucose, fructose, and galactose under pH of 7.0 and 7.5.

Tidal effects on carbon dioxide emission dynamics in intertidal wetland sediments.

Understanding the control mechanisms of carbon dioxide (CO2) emissions in intertidal wetland sediments is beneficial for the concern of global carbon biogeochemistry and climate change. Nevertheless, multiple controls on CO2 emissions from intertidal wetland sediments to the atmosphere still need to be clarified. This study investigated the effect of tidal action on CO2 emissions from salt marsh sediments covered by Spartina alterniflora in the Jiaozhou Bay wetland using the static chamber method combined with an infrared CO2 detector. The results showed that the CO2 emission fluxes from the sediment during ebb tides were higher than those during flood tides. The whole wetland sediment acted as a weak source of atmospheric CO2 (average flux: 24.44 ± 16.80 mg C m-2 h-1) compared to terrestrial soils and was affected by the cycle of seawater inundation and exposure. The tidal influence on vertical dissolved inorganic carbon (DIC) transport in the sediment was also quantitated using a two-end member mixing model. The surface sediment layer (5-15 cm) with maximum DIC concentration during ebb tides became the one with minimum DIC concentration during flood tides, indicating the DIC transport from the surface sediment to seawater. Furthermore, aerobic respiration by microorganisms was the primary process of CO2 production in the sediment according to 16 S rDNA sequencing analysis. This study revealed the strong impact of tidal action on CO2 emissions from the wetland sediment and provided insights into the source-sink pattern of CO2 and DIC at the land-ocean interface.

Effects of school myopia management measures on myopia onset and progression among Chinese primary school students.

BACKGROUND: Schools play an organizational role in managing myopia-related behavioral habits among students. We evaluated the effects of school myopia management measures on myopia onset and progression in a school-based prospective 1-year observational study. METHODS: In total, 8319 children from 26 elementary schools were included. Online questionnaire completed by a parent, in which school myopia management experience including outdoor activities in recess or physical education class, teachers' supervision, and teaching facilities. Variables were defined as implemented well or poorly, according to the Comprehensive Plan to Prevent Myopia among Children and Teenagers. Children underwent ophthalmic examinations, and the incidence and progression of myopia from 2019 to 2020 were estimated. Multilevel logistic regression models were constructed to analyze the association between school management measures and myopia development in 8,9 years and 10,11 years students. RESULTS: From 2019 to 2020, the incidence of myopia among primary school students was 36.49%; the mean difference of spherical equivalent in myopic children was - 0.29 ± 1.22 diopters. The risk of incident myopia was reduced by 20% in 8,9 years participants with well-implemented class recess compared with those with poorly implemented class recess (adjusted odds ratio [aOR]: 0.80, p = 0.032). PE outdoor time was significantly associated with myopia incidence in 10,11 years students (aOR: 0.76, p = 0.043). Compared with poorly implemented reading and writing posture, desk and chair height, 10,11 participants with well-implemented desk and chair height were less likely to have rapid myopic progression (p = 0.029, p = 0.022). CONCLUSION: In Shanghai, children's myopia is associated with better implementation of school myopia management measures. The present findings suggest that outdoor activities during class recess or PE class, providing suitable desks and chairs, and adequate instruction in reading and writing postures might protect against pathological eye growth. An age-specific myopia prevention and control programs in school is of primary importance.

[Relationship between pyroptosis and cardiovascular diseases and traditional Chinese medicine prevention and treatment research].

Pyroptosis is a programmed cell death initiated by the activation of caspases, which is involved in the development and progression of several cardiovascular diseases. The gasdermins, a protein family, are key executive proteins in the development of pyroptosis, which increase cell membrane permeability, mediate the release of inflammatory factors, and aggravate the inflammatory injury. Traditional Chinese medicine(TCM)has shown unique therapeutic advantages in cardiovascular diseases with multi-component and multi-target characteristics. Currently, the effective prevention and treatment of cardiovascular diseases based on the theory of pyroptosis become a new research hotspot in this field. Based on the theories of TCM and modern medicine, this study summarized the role of pyroptosis in cardiovascular diseases such as atherosclerosis, myocardial infarction, diabetic cardiomyopathy, hypertension, and myocarditis. The role of TCM, including active monomers, crude extracts, and compound preparations, in cardiovascular protection through the regulation of pyroptosis was also summarized, providing a theoretical basis for the clinical prevention and treatment of cardiovascular diseases by TCM.

[Mechanism of essential oil from Schizonepeta tenuifolia in treatment of depression based on network pharmacology and experimental verification].

This paper aimed to explore the antidepressant effect of the essential oil from Schizonepeta tenuifolia Briq.(EOST) on the treatment of depression and its mechanism by using a combination of network pharmacology and the mouse model of lipopolysaccharide(LPS)-induced depression. The chemical components in EOST were identified using gas chromatography-mass spectrometer(GC-MS), and 12 active components were selected as the study objects. The targets related to EOST were obtained by Traditional Chinese Medicines Systems Pharmacology(TCMSP) and SwissTargetPrediction database. The targets related to depression were screened out through GeneCards, Therapeutic Target Database(TTD), and Online Mendelian Inheritance in Man(OMIM) database. The Venny 2.1 was applied to screen out the common targets of EOST and depression. The targets were imported into Cytoscape 3.7.2 to generate "drug-active component-diease-target" network diagram. The protein-protein interaction(PPI) network was constructed using STRING 11.5 database and Cytoscape 3.7.2, and the core targets were screened out. DAVID 6.8 database was used for Gene Ontology(GO) func-tional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment analysis, and subsequently the enrichment results were visualized through the bioinformatics platform. The mouse model of depression was induced by intraperitoneally injecting with LPS in mice. Before modeling, mice were administrated orally with EOST. The antidepressant effect of EOST was evalua-ted by tail suspension test(TST), forced swimming test(FST), and novelty suppressed feeding test(NSFT) after modeling. The content of interleukin(IL)-1ß was determined by enzyme-linked immunosorbent assay(ELISA), and the protein expression levels of IL-1ß and pro IL-1ß in the hippocampus were determined by Western blot. There were 12 main components and 179 targets in EOAT, of which, 116 targets were related to depression, mainly involved in neuroactive ligand-receptor interaction, calcium signaling pathway, and cyclic adenosine monophosphate(cAMP) signaling pathway. Biological processes such as synaptic signal transduction, G-protein coupled receptor signaling pathway, and chemical synaptic transmission were involved. Molecular functions such as neurotransmitter receptor activity, RNA polymerase Ⅱ transcription factor activity, and heme binding were involved. In mice experiments, the results showed that EOST at 100 mg·kg~(-1) and 50 mg·kg~(-1) significantly shortened the immobility time in TST and FST as well as the feeding latency in NSFT compared with the model group, decreased the levels of serum IL-1ß and NO, and reduced the protein expression levels of IL-1ß and pro IL-1ß in the hippocampus. In conclusion, EOST shows a good antidepressant effect in a multi-component, multi-target, and multi-pathway manner. The mechanism may be attributed to the fact that EOST can down-regulate the protein expression levels of IL-1ß and pro IL-1ß, decrease the release of inflammatory factors, and reduce neuroinflammation response.

Clinical practice guidelines for the nutritional risk screening and assessment of cancer patients: a systematic quality appraisal using the AGREE II instrument.

PURPOSE: To evaluate the quality of published clinical practice guidelines (CPGs) regarding the nutritional risk screening and assessment of cancer patients and to identify high-quality CPGs for clinical healthcare professionals. METHODS: Guidelines for the nutritional risk screening and assessment of cancer patients were comprehensively searched in eight electronic databases, including The Lancet, PubMed, Cochrane Library, Excerpta Medica dataBASE (EMBASE), Web of Science, China National Knowledge Infrastructure (CNKI), China Biology Medicine disc (CBMdisc), and Wan Fang Data, through August 2020. Six relevant guideline databases, including the National Comprehensive Cancer Network (NCCN), the National Guideline Clearinghouse (NGC), the Guideline International Network (GIN), the New Zealand Guidelines Group (NZGG), the China Guideline Clearinghouse (CGC), and Medlive, and relevant nutrition society websites, were also searched through August 2020. The methodological quality of the included CPGs was appraised independently by three assessors using the Appraisal of Guidelines for Research and Evaluation, 2nd edition (AGREE II) tool. RESULTS: Seven CPGs were located, and the domain with the highest percentage was "clarity of presentation" (85.44%), while the domain with the lowest percentage was "applicability" (40.26%). From the AGREE II results, two guidelines were rated as "strongly recommended," three were assessed as "recommended with modifications," and two were deemed as "not recommended." CONCLUSION: Considering that the two "strongly recommended" guidelines were developed within the American and European contexts, translation, validation, and cultural adaptation are recommended prior to implementing these guidelines in other countries or healthcare contexts to improve their effectiveness and sensitivity for local cancer patients. TRIAL REGISTRATION: PROSPERO registration of the study protocol: CRD42020177390 (July 5, 2020).

Hypofibrinogenemia Caused by Hemocoagulase Injection: A Retrospective Study on Clinical Laboratory Findings.

Objective Hemocoagulase injection based on the venom of Agkistrodon halys Pallas is widely used in the treatment of hemorrhagic disorders. This study aimed to characterize the clinical laboratory findings of hemocoagulase-induced hypofibrinogenemia as the associated adverse reaction of hemocoagulase injection.Methods We retrospectively enrolled 27 in-patients who were treated with hemocoagulase injection for hemoptysis and developed hypofibrinogenemia during the period of January 1, 2015 to March 31, 2018. Clinical data were collected and investigated, including clinical manifestations, hemostatic and fibrinolytic parameters, dosage of hemocoagulase, the medication time, and the cryoprecipitate blood product infusion. Differences in fibrinogen, D-dimer, and fibrin/fibrinogen degradation products (FDP) before, during, and after the application of hemocoagulase injection were analyzed statistically.Results Plasma fibrinogen level during medication of hemocoagulase injection decreased significantly compared to that before the treatment (F=1.80, P<0.001), with the average decrease of 2.28 g/L (0.63-3.9 g/L). After withdrawal, fibrinogen level increased significantly compared to that during the medication (F=-1.20, P<0.001), but was still lower than that before the medication (F=0.59, P=0.03). The D-dimer level and the FDP level after withdrawal decreased significantly compared to the levels during the medication (F=0.83, P=0.002; Wilcoxon-test, Z=-4.54, P<0.001). Spearman's correlation analyses did not find either fibrinogen change during-before the administration or FDP change after-during the administration was associated with the dosage of hemocoagulase (r=-0.17, P=0.40; r=-0.28, P=0.15; respectively) and the time of recovery from hypofibrinogenemia (r=-0.45, P=0.05; r=0.13, P=0.61; respectively).Conclusion Monitoring both clotting and fibrinolysis parameters is essential in the management of hemoptysis patients treated with hemocoagulase injection. Clinicians should be aware of hypofibrinogenemia and consider discontinuation of the administration of hemocoagulase whenever necessary.

Emission of CO2 and its related carbonate system dynamics in a hotspot area during winter and summer: The Changjiang River estuary.

The carbonate chemistry in river-dominated marginal seas is highly heterogeneous, and there is ongoing debate regarding the definition of atmospheric CO2 source or sink. On this basis, we investigated the carbonate chemistry and air-sea CO2 fluxes in a hotspot estuarine area: the Changjiang Estuary during winter and summer. The spatial characteristics of the carbonate system were influenced by water mixing of three end-members in winter, including the Changjiang freshwater with low total alkalinity (TA) concentration, the less saline Yellow Sea Surface Water with high TA, and the saline East China Sea (ECS) offshore water with moderate TA. While in summer with increased river discharge, the carbonate system was regulated by simplified two end-member mixing between the Changjiang freshwater and the ECS offshore water. By performing the end-member mixing model on DIC variations in the river plume region, significant biological addition of DIC was found in winter with an estimation of -120 ± 113 µmol kg-1 caused by wintertime organic matter remineralization from terrestrial source. While this biological addition of DIC shifted to DIC removal due to biological production in summer supported by the increased nutrient loading from Changjiang River. The pCO2 dynamics in the river plume and the ECS offshore were both subjected to physical mixing of freshwater and seawater, whether in winter and summer. In the inner estuary without horizontal mixing, the pCO2 dynamics were mainly influenced by biological uptake in winter and temperature in summer. The inner estuary, the river plume, and the ECS offshore were sources of atmospheric CO2, with their contributions varying seasonally. The Changjiang runoff enhanced the inner estuary's role as a CO2 source in summer, while intensive biological uptake reduced the river plume's contribution.

Regulation of seawater dissolved carbon pools by environmental changes in Ulva prolifera originating sites: A new perspective on the contribution of U. prolifera to the seawater carbon sink function.

The Ulva prolifera bloom is considered one of the most serious ecological disasters in the Yellow Sea in the past decade, forming a carbon sink in its source area within a short period but becoming a carbon source at its destination. To explore the effects of different environmental changes on seawater dissolved carbon pools faced by living U. prolifera in its originating area, U. prolifera were cultured in three sets with different light intensity (54, 108, and 162 µmol m-2 s-1), temperature (12, 20, and 28 °C) and nitrate concentration gradients (25, 50, and 100 µmol L-1). The results showed that moderate light (108 µmol m-2 s-1), temperature (20 °C), and continuous addition of exogenous nitrate significantly enhanced the absorption of dissolved inorganic carbon (DIC) in seawater by U. prolifera and most promoted its growth. Under the most suitable environment, the changes in the seawater carbonate system were mainly dominated by biological production and denitrification, with less influence from aerobic respiration. Facing different environmental changes, U. prolifera continuously changed its carbon fixation mode according to tissue δ13C results, with the changes in the concentrations of various components of DIC in seawater, especially the fluctuation of HCO3- and CO2 concentrations. Enhanced light intensity of 108 µmol m-2 s-1 could shift the carbon fixation pathway of U. prolifera towards the C4 pathway compared to temperature and nitrate stimulation. Environmental conditions at the origin determined the amount of dissolved carbon fixed by U. prolifera. Therefore, more attention should be paid to the changes in marine environmental conditions at the origin of U. prolifera, providing a basis for scientific management of U. prolifera.

Nitrogen oxides emissions from coastal wetland sediments: Experimental assessment of the influence of vegetation and nitrogen input.

Nitrogen oxides (NOx = NO + NO2) have essential impacts on global climate and the environment, making it essential to study the contribution of wetland-generated NOx to environmental problems. With exogenous nitrogen input from anthropogenic activities, wetland sediments become active emission hotspots for NOx. In this study, we conducted field experiments in a typical salt marsh wetland to measure nitric oxide (NO, the primary component of NOx from sediments) exchange fluxes in both mudflat and vegetated sediments. We found that NO fluxes in vegetated sediments (0.40 ±â€¯0.15 × 10-12 kg N m-2 s-1) were relatively higher than in mudflat sediments (-1.31 ±â€¯1.39 × 10-12 kg N m-2 s-1), with this difference occurring only during the vegetation-dying season (autumn). Correlations between sediment NO fluxes and environmental parameters revealed that NO flux variation during the observation period was primarily influenced by sediment respiration, temperature, water content, and substrate availability. However, the influence of these factors on NO fluxes differed between mudflat and vegetated sediments. In-situ data analysis also suggested that tidal horizontal migration, which affects sediment substrate and salinity, may regulate sediment NO emissions. Furthermore, in-situ incubations with nitrogen addition (ammonia, nitrite, and nitrate) were conducted to study the response of sediment NO emissions to exogenous nitrogen. We observed that nitrogen addition caused a 259.7 % increase in NO emissions from vegetated sediments compared to the control during the effective period of nitrogen addition (days 1-3). However, although nitrogen addition markedly stimulated sediment NO emissions, the overall NO production capacity constrained the extent of this increase.