Multi-site sulfonation of lignin for the synthesis of a high-performance dye dispersant.

Sulfonated lignin-based dye dispersants have intensively attracted attention due to their low cost, renewability and abundant sources. However, their utilization is limited by the low content of sulfonic groups and high content of hydroxyl groups in their complex lignin structure, which results in various problems such as high reducing rate of dye, severe staining of the fibers and uneven dyeing. Here, the multi-site sulfonated lignin-based dispersants were prepared with high sulfonic group content (2.20 mmol/g) and low hydroxyl content (2.43 mmol/g). When using it as the dispersant, the dye uptake rate was improved from 69.23 % to 98.55 %, the reducing rate was decreased from 20.82 % to 2.03 %, the K/S value was reduced from 0.69 to 0.02, and the particle sizes in dye system before and after high temperature treatment were stabilized below 0.5 µm. Besides, the dispersion effect was significantly improved because no obvious separation between dye and water was observed even if without the assistance of grinding process. In short, the multi-site sulfonation method proposed in this work could remarkably improve the performances of the lignin-based dye dispersants, which would facilitate the development of the dye dispersion and the high value utilization of lignin.

Flexible Sandwich-Shaped Cellulose Nanocrystals/Silver Nanowires/MXene Films Exhibit Efficient Electromagnetic-Shielding Interference Performance.

The electromagnetic pollution problem is becoming increasingly serious due to the speedy advance of electronic communication devices. There are broad application prospects for the development of flexible, wearable composite films with high electromagnetic interference (EMI)-shielding performance. The MX@AC composite films were prepared from MXene, silver nanowires (AgNWs) and cellulose nanocrystals (CNCs) with a sandwich structure. Benefiting from the upper and lower frame structure formed by winding 1D AgNWs and CNC, the tensile strength of the MX@AC was improved to 35 MPa (12.5 wt% CNC content) from 4 MPa (0 wt% CNC content). The high conductivity of MXene and AgNWs resulted in the MX@AC composite film conductivity up to 90,670 S/m, EMI SE for 90 dB, as well as SSE/t up to 7797 dB cm2 g-1. And the MX@AC composite film was tested for practical application, showing that it can effectively isolate electromagnetic waves in practical application.

A nomogram for predicting severe adenovirus pneumonia in children.

Adenoviral pneumonia in children was an epidemic that greatly impacted children's health in China in 2019. Currently, no simple or systematic scale has been introduced for the early identification and diagnosis of adenoviral pneumonia. The early recognition scale of pediatric severe adenovirus pneumonia was established based on an analysis of the children's community-acquired pneumonia clinical cohort. This study analyzed the clinical data of 132 children with adenoviral pneumonia who were admitted to the Children's Hospital of Nanjing Medical University. The clinical parameters and imaging features were analyzed using univariate and multivariate logistic regression analyses. A nomogram was constructed to predict the risk of developing severe adenovirus pneumonia in children. There were statistically significant differences in age, respiratory rate, fever duration before admission, percentage of neutrophils and lymphocytes, CRP, ALT, and LDH between the two groups. Logistic regression analysis was conducted using the R language, and respiratory rate, percentage of neutrophils, percentage of lymphocytes, and LDH were used as scale indicators. Using the ROC curve, the sensitivity and specificity of the scale were 93.3% and 92.1%. This scale has good sensitivity and specificity through internal verification, which proves that screening for early recognition of severe adenovirus pneumonia can be realized by scales. This predictive scale helps determine whether a child will develop severe adenovirus pneumonia early in the disease course.

Giant Panda Microhabitat Study in the Daxiangling Niba Mountain Corridor.

Habitat reduction and increased fragmentation are urgent issues for the survival and recovery of the giant panda (Ailuropoda melanoleuca). However, changes in the distribution and microhabitat selection of giant panda habitats in different seasons in the same region have rarely been assessed. To further understand giant panda habitat requirements, this study analyzed the giant panda habitat selection characteristics and differences using the sample data of the giant panda occurrence sites collected during 2020-2022. The results showed that the giant panda in both seasons selected medium altitudes (2000-2400 m), southeastern slopes, slopes less than 15°, taller tree layers (8-15 m) with a larger diameter at breast height (17-25 cm) and medium density (25-55%), shorter shrub layers (<4 m) with sparse density (<30%), and taller bamboo (>2 m) with high density (>35%). The giant panda microhabitat survey in the Niba Mountain corridor clarified the characteristics of suitable habitat selection for the giant panda in the corridor. The findings of the study can provide scientific references for the development of practical habitat conservation and management measures for giant pandas in the study area.

Habitat restoration is the greatest challenge for population recovery of Hainan gibbons (Nomascus hainanus).

Hainan gibbons are among the world's most critically endangered primates, with a remaining population of only 35 individuals distributed across 5 social groups in the Bawangling Branch of the Hainan Tropical Rainforest National Park, China. Habitat conversion and forest fragmentation over the past 40 years have reduced their geographical distribution by 95%. In the absence of a quantitative assessment of the availability of remaining suitable habitat, it is unclear whether this species can survive to the end of this century. We used behavioral observations, ArcGIS, remote sensing, stereo optical imagery, and MaxEnt modeling to identify patterns of Hainan gibbon range use and compare changes in the distribution of suitable forest types and areas of forest fragmentation over the past 20 years (2000-2020). The results indicate that the combined range of the 5 extant Hainan gibbon groups totaled 14.89 km2 . The home range of the smallest group (Group E, 3 individuals) was 1.51 km2 , which likely represents the minimum home range size for this species. The remaining area of highly suitable and moderately suitable habitat totals 26.9 km2 . However, habitat connectivity across the gibbon range is very low (less than 0.5), limiting the ability of Hainan gibbons to move between forest patches. The results of this study indicate that the availability of suitable habitat in Bawangling is insufficient to allow for future Hainan gibbon population growth. Therefore, immediate action must be taken to restore, reforest, and establish ecological corridors to reconnect areas of suitable habitat for these critically endangered gibbons.

Preparation of activated lignin with high hydroxyl content using lewis acid as demethylation reagent.

Activation of lignin by demethylation for improving the reactivity has attracted extensive attentions. However, it still faces many challenges, such as the unsatisfied increase of hydroxyl content and the undesired cracking of linear linkages. Here, the efficient demethylations for significantly increasing the hydroxyl content and protecting the structure of industrial lignin were explored using lewis acid as modification reagent. As BBr3 was used, the phenolic hydroxyl content (Ar-OH) was increased by 80.65 %, but the lignin structure might be destroyed. About 75 % of the ß-O-4 linkages could be fortunately retained by using AlCl3. This method could also be used for the demethylation of alkaline poplar lignin with up to 171.67 % increase of Ar-OH (from 1.80 to 4.89 mmol/g). After activation, the antioxidant properties were improved 4.64-fold and 2.58-fold for 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals, respectively. This work would provide a theory guidance for activation of lignin and facilitate its high-value application.

Phylogenetic analysis of combined mitochondrial genome and 32 nuclear genes provides key insights into molecular systematics and historical biogeography of Asian warty newts of the genus Paramesotriton (Caudata: Salamandridae).

The Paramesotriton Chang, 1935 genus of Asian warty newts is the second most diverse genus in the family Salamandridae, currently containing 14 recognized species from northern Vietnam to southwest-central and southern China. Although species of this genus have been included in previous phylogenetic studies, the origin and interspecific relationships of the genus are still not fully resolved, especially at key nodes in the phylogeny. In this study, we sequenced mitochondrial genomes and 32 nuclear genes from 27 samples belonging to 14 species to reconstruct the interspecific phylogenetic relationships within Paramesotriton and explore its historical biogeography in southern China. Both Bayesian inference and maximum-likelihood analyses highly supported the monophyly of Paramesotriton and its two recognized species groups ( P. caudopunctatus and P. chinensis groups) and further identified five hypothetical phylogenetic cryptic species. Biogeographic analyses indicated that Paramesotriton originated in southwestern China (Yunnan-Guizhou Plateau/South China) during the late Oligocene. The time of origin of Paramesotriton corresponded to the second uplift of the Himalayan/Qinghai-Xizang (Tibetan) Plateau (QTP), rapid lateral extrusion of Indochina, and formation of karst landscapes in southwestern China. Principal component analysis (PCA), independent sample t-tests, and niche differentiation using bioclimatic variables based on locations of occurrence suggested that Paramesotriton habitat conditions in the three current regions (West, South, and East) differ significantly, with different levels of climatic niche differentiation. Species distribution model (SDM) predictions indicated that the most suitable distribution areas for the P. caudopunctatus and P. chinensis species groups are western and southern/eastern areas of southern China. This study increases our knowledge of the taxonomy, biodiversity, origin, and suitable distribution areas of the genus Paramesotriton based on phylogenetic, biogeographic, and species distribution models.

The complete mitochondrial genome of the Great evening bat Ia io (Chiroptera: Vespertiilionidae) from karst area, Southwestern China.

In this study, the complete mitochondrial genome of Ia io from Guizhou Province, China. The genome was a circular mitochondrial genome of 16689 bp in length, containing 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNA), 2 ribosomal RNA genes (rRNA), and a control region. The average base composition is 32.76% A, 24.59% C, 14.49% G, and 28.16% T. The first complete mitochondrial genome of I. io provides fundamental data for future systematic taxonomic studies of the genus Ia.

H2O2-Mediated Oxidative Stress Enhances Cystathionine γ-Lyase-Derived H2S Synthesis via a Sulfenic Acid Intermediate.

Hydrogen sulfide (H2S), which is generated mainly by cystathionine γ-lyase (CSE) in the cardiovascular system, plays a pivotal role in a wide range of physiological and pathological processes. However, the regulatory mechanism of the CSE/H2S system is poorly understood. Herein, we show that oxidation induces the disulfide bond formation between Cys252 and Cys255 in the CXXC motif, thus stimulating the H2S-producing activity of CSE. The activity of oxidized CSE is approximately 2.5 fold greater than that of the reduced enzyme. Molecular dynamics and molecular docking suggest that the disulfide bond formation induces the conformational change in the active site of CSE and consequently increases the affinity of the enzyme for the substrate L-cysteine. Mass spectrometry and mutagenesis studies further established that the residue Cys255 is crucial for oxidation sensing. Oxidative stress-mediated sulfenylation of Cys255 leads to a sulfenic acid intermediate that spontaneously forms an intramolecular disulfide bond with the vicinal thiol group of Cys252. Moreover, we demonstrate that exogenous hydrogen peroxide (H2O2) and endogenous H2O2 triggered by vascular endothelial growth factor (VEGF) promote cellular H2S production through the enhancement of CSE activity under oxidative stress conditions. By contrast, incubation with H2O2 or VEGF did not significantly enhance cellular H2S production in the presence of PEG-catalase, an enzymatic cell-permeable H2O2 scavenger with high H2O2 specificity. Taken together, we report a new posttranslational modification of CSE that provides a molecular mechanism for H2O2/H2S crosstalk in cells under oxidative stress.

Chinese herbal medicine therapy for coronary heart disease complicated with anxiety: a systematic review of randomized controlled trials.

OBJECTIVE: To evaluated the effectiveness and safety of Chinese herbal medicines (CHMs) for coronary heart disease (CHD) complicated with anxiety. METHODS: Randomized controlled clinical trials (RCTs) with parallel-groups were included after searching through electric-databases from inception to May, 2017. Meta-analysis was undertaken with RevMan 5.3 software. RESULTS: Twenty-three RCTs enrolling 1654 patients were included in this systematic review. The combination therapy (CHMs combined with anxiolytic) appeared to be superior to anxiolytic in terms of reducing the score of Zung Self-rating Anxiety scale (SAS) (mean Difference (MD), －12.25; 95% confidence interval (CI), －14.01 to －10.48, eliminating method; MD, －3.92; 95% CI, －5.48 to －2.35, tranquilizing method), improving the total effect rate (relative risk (RR), 1.26; 95% CI, 1.08 to 1.46, eliminating method) and reducing the TCM symptoms scores (MD, －2.24; 95% CI, －4.25 to －0.23, tranquilizing method) with a lower incidence of adverse events (RR, 0.46; 95% CI, 0.25 to 0.85, tonifying method). CHMs demonstrated benefits in lowering the score of Hamilton Anxiety Rating scale (MD, －6.77; 95% CI, －8.16 to －5.37, tonifying method),lowering the score of SAS (MD, －10.1; 95% CI, －13.73 to －6.30, tonifying method) and reducing the TCM symptoms scores (MD, －2.18; 95% CI, －3.12 to －1.24, tranquilizing method). CONCLUSION: We got a low evidence that CHMs,which had less side effects, showed potentially benefits to patients with CHD complicated with anxiety. While the results should be interpreted with caution. Trails with higher quality are required to verify the effectiveness and safety of CHMs for CHD complicated with anxiety.

Hydrogen Sulfide From Cysteine Desulfurase, Not 3-Mercaptopyruvate Sulfurtransferase, Contributes to Sustaining Cell Growth and Bioenergetics in E. coli Under Anaerobic Conditions.

Endogenous hydrogen sulfide (H2S), which is primarily generated by 3-mercaptopyruvate sulfurtransferase (3-MST) in Escherichia coli (E. coli) under aerobic conditions, renders bacteria highly resistant to oxidative stress. However, the biosynthetic pathway and physiological role of this gas under anaerobic conditions remains largely unknown. In the present study, we demonstrate that cysteine desulfurase (IscS), not 3-MST, is the primary source of endogenous H2S in E. coli under anaerobic conditions. A significant decrease in H2S production under anaerobic conditions was observed in E. coli upon deletion of IscS, but not in 3-MST-deficient bacteria (ΔmstA). Furthermore, the H2S-producing activity of recombinant IscS using L-cysteine as a substrate exhibited an approximately 2.6-fold increase in the presence of dithiothreitol (DTT), indicating that H2S production catalyzed by IscS was greatly increased under reducing conditions. The activity of IscS was regulated under the different redox conditions and the midpoint redox potential was determined to be -329 ± 1.6 mV. Moreover, in E. coli cells H2S production from IscS is regulated under oxidative and reductive stress. A mutant E. coli (ΔiscS) strain lacking a chromosomal copy of the IscS-encoding gene iscS showed significant growth defects and low levels of ATP under both aerobic and anaerobic conditions. The growth defects could be fully restored after addition of 500 µM Na2S (an H2S donor) under anaerobic conditions, but not by the addition of cysteine, sodium sulfite or sodium sulfate. We also showed that the addition of 500 µM Na2S to culture medium stimulates ATP synthesis in the mutant E. coli (ΔiscS) strain in the logarithmic growth phase but suppresses ATP synthesis in wild-type E. coli. Our results reveal a new H2S-producing pathway in E. coli under anaerobic conditions and show that hydrogen sulfide from IscS contributes to sustaining cell growth and bioenergetics under oxygen-deficient conditions.

Anti-depressive effect of Shuangxinfang on rats with acute myocardial infarction: Promoting bone marrow mesenchymal stem cells mobilization and alleviating inflammatory response.

Bone marrow mesenchymal stem cells (BM-MSCs) are recruited to injured site for cardiac self-repairing in acute myocardial infarction (AMI), but the spontaneous mobilization of BM-MSCs is insufficient for self-repairing. Inflammation initiated by necrosis cardiomyocytes induced cardiac remodeling and depression. Given the anti-inflammatory effects of BM-MSCs and the inextricably relationship among inflammation, ventricular remodeling and depression following AMI, methods focused on enhancing BM-MSCs mobilization are promising. Shuangxinfang (Psycho-cardiology Formula, PCF) is a classical traditional Chinese medicine prescription. In this study, we explored its psycho-cardiology effects in rats with AMI and explore its potential mechanism. Our results showed PCF inhibited inflammation caused by injured myocardium, improved heart function and depression developed from myocardial infarction, and these might partly attribute to the higher BM-MSCs mobilization efficiency promoted by PCF.

Antitumor effect of sikokianin C, a selective cystathionine ß-synthase inhibitor, against human colon cancer in vitro and in vivo.

Cystathionine ß-synthase (CBS) overexpression is related to the proliferation and migration of human colon cancers. Targeted therapy that inhibits CBS has achieved promising effects in colon cancer treatments, but no selective inhibitor of CBS is available. In our previous study, a natural biflavonoid compound, sikokianin C, was identified as a potent and selective inhibitor of CBS. However, the mode of action of this compound and its antitumor efficacy in vivo remain unknown. In the present study, we have demonstrated that sikokianin C selectively inhibits CBS activity in a competitive manner, and the five key residues involved in the binding of sikokianin C to the substrate channel of CBS protein were identified via a combination of molecular docking and site-directed mutagenesis. Additionally, we analyzed the antitumor efficacy of sikokianin C against human colon cancer cells in vitro and in vivo. Sikokianin C greatly suppressed the proliferation of HT29 colon cancer cells with an IC50 value of 1.6 µM, and CBS is the target of sikokianin C in mammalian cells, as evidenced by CBS knockdown analyses. Moreover, sikokianin C induced the apoptosis of HT29 cancer cells in a dose dependent manner. Treating mice with sikokianin C dramatically reduced the tumor volume and the weight of the colon cancer xenograft in vivo. These results indicate that the selective CBS inhibitor sikokianin C can potentially be used for the treatment of colon cancer.

Chaihulonggumulitang Shows Psycho-cardiology Therapeutic Effects on Acute Myocardial Infarction by Enhancing Bone Marrow Mesenchymal Stem Cells Mobilization.

Ischemic myocardium initiates the mobilization and homing of bone marrow mesenchymal stem cells (BM-MSCs) to promote myocardial regeneration after acute myocardial infarction (AMI). Inflammation caused by necrotic cardiomyocytes induce major pathological changes (cardiac remodeling and myocardial apoptosis) as well as anxiety disorder. This process may be inhibited by the differentiation and paracrine effects of BM-MSCs. However, the spontaneous mobilization of BMSCs is insufficient to prevent this effect. Given the anti-inflammatory effects of BM-MSCs, ventricular remodeling and anxiety following AMI, methods focused on enhancing BMSCs mobilization are promising. BFG is a classical traditional Chinese prescription medicine and has been proved effective in treating AMI and reducing anxiety, but the potential mechanism of its function remains unknown. In the present study, we explored the effects of Chaihulonggumulitang (BFG) on AMI and anxiety in vivo and in vitro. We also tested its effects in promoting BMSCs mobilization and alleviating inflammation. Our data showed that the classical Chinese prescription BFG promoted BM-MSCs mobilization, inhibited inflammatory response, and improved heart damage and anxiety developed from AMI. Thus, we provided an underlying mechanism of BFG function in psycho-cardiology conditions such as AMI.

Allosteric control of human cystathionine ß-synthase activity by a redox active disulfide bond.

Cystathionine ß-synthase (CBS) is the central enzyme in the trans-sulfuration pathway that converts homocysteine to cysteine. It is also one of the three major enzymes involved in the biogenesis of H2S. CBS is a complex protein with a modular three-domain architecture, the central domain of which contains a 272CXXC275 motif whose function has yet to be determined. In the present study, we demonstrated that the CXXC motif exists in oxidized and reduced states in the recombinant enzyme by mass spectroscopic analysis and a thiol labeling assay. The activity of reduced CBS is ∼2-3-fold greater than that of the oxidized enzyme, and substitution of either cysteine in CXXC motif leads to a loss of redox sensitivity. The Cys272-Cys275 disulfide bond in CBS has a midpoint potential of -314 mV at pH 7.4. Additionally, the CXXC motif also exists in oxidized and reduced states in HEK293 cells under oxidative and reductive conditions, and stressing these cells with DTT results in more reduced enzyme and a concomitant increase in H2S production in live HEK293 cells as determined using a H2S fluorescent probe. By contrast, incubation of cells with aminooxyacetic acid, an inhibitor of CBS and cystathionine γ-lyase, eliminated the increase of H2S production after the cells were exposed to DTT. These findings indicate that CBS is post-translationally regulated by a redox-active disulfide bond in the CXXC motif. The results also demonstrate that CBS-derived H2S production is increased in cells under reductive stress conditions.

Characterization of on-road CO, HC and NO emissions for petrol vehicle fleet in China city.

Vehicle emissions are a major source of air pollution in urban areas. The impact on urban air quality could be reduced if the trends of vehicle emissions are well understood. In the present study, the real-world emissions of vehicles were measured using a remote sensing system at five sites in Hangzhou, China from February 2004 to August 2005. More than 48000 valid gasoline powered vehicle emissions of carbon monoxide (CO), hydrocarbons (HC) and nitrogen oxide (NO) were measured. The results show that petrol vehicle fleet in Hangzhou has considerably high CO emissions, with the average emission concentration of 2.71%+/-0.02%, while HC and NO emissions are relatively lower, with the average emission concentration of (153.72+/-1.16)x10(-6) and (233.53+/-1.80)x10(-6), respectively. Quintile analysis of both average emission concentration and total amount emissions by model year suggests that in-use emission differences between well maintained and badly maintained vehicles are larger than the age-dependent deterioration of emissions. In addition, relatively new high polluting vehicles are the greatest contributors to fleet emissions with, for example, 46.55% of carbon monoxide fleet emissions being produced by the top quintile high emitting vehicles from model years 2000-2004. Therefore, fleet emissions could be significantly reduced if new highly polluting vehicles were subject to effective emissions testing followed by appropriate remedial action.