Effects of tumor marker regression load score on long-term prognosis of gastric cancer patients undergoing radical surgery after neoadjuvant chemotherapy.

BACKGROUND: The effects of the dynamics of serum tumor markers (CA72-4, CEA, CA19-9, CA125 and AFP) before and after neoadjuvant chemotherapy (NACT) on the prognosis of gastric cancer(GC) patients remain unclear. METHODS: The training set contained 334 GC patients from Fujian Medical University Union Hospital (FJMUUH) and 113 GC patients in Qinghai University Affiliated Hospital (QhUAH) were used as an external validation set. Tumor marker regression load (ΔTMRL) indicator, including ΔCA72-4, ΔCEA, ΔCA19-9, ΔCA125, and ΔAFP, is defined as [(postNACT marker- preNACT marker)/preNACT marker]. Tumor marker regression load score (TMRLS) consists of ΔCA72-4, ΔCEA and ΔCA125. The predictive performance of the nomogram-TMRLS was evaluated using the area under the receiver operating characteristic(ROC) curve(AUC), decision curve analysis(DCA), and C-index. RESULTS: Patients from FJMUUH were divided into two groups, TMRLS-low and TMRLS-high, determined by R package maxstat. Survival analysis revealed a higher 3-year overall survival(OS) in the TMRLS-low than in the TMRLS-high group. The TMRLS-high group who received postoperative adjuvant chemotherapy(AC) showed a significantly higher 3-year OS rate than those who did not. Multivariate COX regression analysis indicated that TMRLS was an independent prognostic factor for OS. A nomogram for predicting OS based on TMRLS showed a significantly higher C-index and AUC than the ypTNM stage. The above results were also found in the QhUAH external validation cohort. CONCLUSION: TMRLS is a novel independent prognostic factor for GC who underwent NACT and a radical gastrectomy. Furthermore, the TMRLS-high group, who received postoperative AC, may achieve better survival outcomes. Notably, the predictive performance of the nomogram-TMRLS significantly outperformed that of the ypTNM stage.

Denitrification Characteristics of the Low-Temperature Tolerant Denitrification Strain Achromobacter spiritinus HS2 and Its Application.

The low-temperature environment significantly inhibits the growth and metabolism of denitrifying bacteria, leading to an excessive concentration of ammonia nitrogen and total nitrogen in sewage treatment plants during the cold season. In this study, an efficient denitrifying strain of heterotrophic nitrification-aerobic denitrification (HN-AD) bacteria named HS2 was isolated and screened from industrial sewage of a chemical factory in Inner Mongolia at 8 °C. The strain was confirmed to be Achromobacter spiritinus, a colorless rod-shaped bacterium. When cultured with sodium succinate as the carbon source, a carbon-to-nitrogen ratio of 20-30, a shaking rate of 150-180 r/min, and an initial pH of 6-10, the strain HS2 exhibited excellent nitrogen removal at 8 °C. Through the results of whole-genome sequencing, gene amplification, and gas product detection, the strain HS2 was determined to possess key enzyme genes in both nitrification and denitrification pathways, suggesting a HN-AD pathway of NH4+-N → NH2OH → NO2-N → NO → N2O → N2. At 8 °C, the strain HS2 could completely remove ammonia nitrogen from industrial sewage with an initial concentration of 127.23 mg/L. Microbial species diversity analysis of the final sewage confirmed Achromobacter sp. as the dominant genus, which indicated that the low-temperature denitrifying strain HS2 plays an important role in nitrogen removal in actual low-temperature sewage.

Trajectories of neutrophil-to-lymphocyte ratios during neoadjuvant chemotherapy correlate with short- and long-term outcomes in gastric cancer: a group-based trajectory analysis.

BACKGROUND: Systemic inflammatory factors can predict the survival prognosis of gastric cancer (GC) patients after neoadjuvant chemotherapy (NACT). However, whether longitudinal changes in systemic inflammatory factors are associated with short - and long-term outcomes has not been reported. METHODS: This study is a retrospective analysis of 216 patients with advanced gastric cancer who received NACT between January 2011 and June 2019, comparing receiver operating characteristic (ROC) curves for screening suitable inflammatory markers. Group-based trajectory modeling (GBTM) was used to analyze longitudinal changes in inflammatory markers during NACT to identify different potential subgroups and to compare postoperative complications, recurrence-free survival (RFS), and overall survival (OS) among subgroups. RESULTS: Ultimately, neutrophil-lymphocyte ratio (NLR) had the highest area under the curve (AUC) value in predicting prognosis was included in the GBTM analysis. Three trajectories of NLR were obtained: Stable group (SG) (n = 89), Ascent-descend group (ADG) (n = 80) and Continuous descend group (CDG) (n = 47). Compared with SG, ADG and CDG are associated with an increased risk of postoperative recurrence and death. The median time of RFS and OS of SG was longer than that of ADG and CDG (median RFS 81 vs. 44 and 22 months; median OS 69 vs. 41 and 30 months). In addition, CDG had significantly higher postoperative serious complications than SG and ADG (17 (36.2%) vs. 17 (19.1%) and 12 (15.0%); p = 0.005). CONCLUSION: There were different trajectories of NLR during NACT, and these potential trajectories were significantly associated with severe postoperative complications, recurrence, and mortality in patients with GC.

Developmental Toxicity of PEDOT:PSS in Zebrafish: Effects on Morphology, Cardiac Function, and Intestinal Health.

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is a conductive polymer commonly used in various technological applications. However, its impact on aquatic ecosystems remains largely unexplored. In this study, we investigated the toxicity effects of PEDOT:PSS on zebrafish. We first determined the lethal concentration (LC50) of PEDOT:PSS in zebrafish and then exposed AB-type zebrafish embryos to different concentrations of PEDOT:PSS for 120 h. Our investigation elucidated the toxicity effects of zebrafish development, including morphological assessments, heart rate measurements, behavioral analysis, transcriptome profiling, and histopathological analysis. We discovered that PEDOT:PSS exhibited detrimental effects on the early developmental stages of zebrafish, exacerbating the oxidative stress level, suppressing zebrafish activity, impairing cardiac development, and causing intestinal cell damage. This study adds a new dimension to the developmental toxicity of PEDOT:PSS in zebrafish. Our findings contribute to our understanding of the ecological repercussions of PEDOT:PSS and highlight the importance of responsible development and application of novel materials in our rapidly evolving technological landscape.

Biogeographic patterns of meio- and micro-eukaryotic communities in dam-induced river-reservoir systems.

Although the Three Gorges Dam (TGD) is the world's largest hydroelectric dam, little is known about the spatial-temporal patterns and community assembly mechanisms of meio- and micro-eukaryotes and its two subtaxa (zooplankton and zoobenthos). This knowledge gap is particularly evident across various habitats and during different water-level periods, primarily arising from the annual regular dam regulation. To address this inquiry, we employed mitochondrial cytochrome c oxidase I (COI) gene-based environmental DNA (eDNA) metabarcoding technology to systematically analyze the biogeographic pattern of the three communities within the Three Gorges Reservoir (TGR). Our findings reveal distinct spatiotemporal characteristics and complementary patterns in the distribution of meio- and micro-eukaryotes. The three communities showed similar biogeographic patterns and assembly processes. Notably, the diversity of these three taxa gradually decreased along the river. Their communities were less shaped by stochastic processes, which gradually decreased along the longitudinal riverine-transition-lacustrine gradient. Hence, deterministic factors, such as seasonality, environmental, and spatial variables, along with species interactions, likely play a pivotal role in shaping these communities. Environmental factors primarily drive seasonal variations in these communities, while hydrological conditions, represented as spatial distance, predominantly influence spatial variations. These three communities followed the distance-decay pattern. In winter, compared to summer, both the decay and species interrelationships are more pronounced. Taken together, this study offers fresh insights into the composition and diversity patterns of meio- and micro-eukaryotes at the spatial-temporal level. It also uncovers the mechanisms behind community assembly in various environmental niches within the dam-induced river-reservoir systems. KEY POINTS: • Distribution and diversity of meio- and micro-eukaryotes exhibit distinct spatiotemporal patterns in the TGR. • Contribution of stochastic processes in community assembly gradually decreases along the river. • Deterministic factors and species interactions shape meio- and micro-eukaryotic community.

Comparison of Short-Term Outcomes After Robotic Versus Laparoscopic Radical Gastrectomy for Advanced Gastric Cancer in Elderly Individuals: A Propensity Score-Matching Study.

BACKGROUND: Robotic gastrectomy (RG) has been widely used to treat gastric cancer. However, whether the short-term outcomes of robotic gastrectomy are superior to those of laparoscopic gastrectomy (LG) for elderly patients with advanced gastric cancer has not been reported. METHODS: The study enrolled of 594 elderly patients with advanced gastric cancer who underwent robotic or laparoscopic radical gastrectomy. The RG cohort was matched 1:3 with the LG cohort using propensity score-matching (PSM). RESULTS: After PSM, 121 patients were included in the robot group and 363 patients in the laparoscopic group. Excluding the docking and undocking times, the operation time of the two groups was similar (P = 0.617). The RG group had less intraoperative blood loss than the LG group (P < 0.001). The time to ambulation and first liquid food intake was significantly shorter in the RG group than in the LG group (P < 0.05). The incidence of postoperative complications did not differ significantly between the two groups (P = 0.14). Significantly more lymph nodes were dissected in the RG group than in the LG group (P = 0.001). Postoperative adjuvant chemotherapy was started earlier in the RG group than in the LG group (P = 0.02). CONCLUSIONS: For elderly patients with advanced gastric cancer, RG is safe and feasible. Compared with LG, RG is associated with less intraoperative blood loss; a faster postoperative recovery time, allowing a greater number of lymph nodes to be dissected; and earlier adjuvant chemotherapy.

Supervised machine learning improves general applicability of eDNA metabarcoding for reservoir health monitoring.

Effective and standardized monitoring methodologies are vital for successful reservoir restoration and management. Environmental DNA (eDNA) metabarcoding sequencing offers a promising alternative for biomonitoring and can overcome many limitations of traditional morphological bioassessment. Recent attempts have even shown that supervised machine learning (SML) can directly infer biotic indices (BI) from eDNA metabarcoding data, bypassing the cumbersome calculation process of BI regardless of the taxonomic assignment of eDNA sequences. However, questions surrounding the general applicability of this taxonomy-free approach to monitoring reservoir health remain unclear, including model stability, feature selection, algorithm choice, and multi-season biomonitoring. Here, we firstly developed a novel biological integrity index (Me-IBI) that integrates multitrophic interactions and environmental information, based on taxonomy-assigned eDNA metabarcoding data. The Me-IBI can better distinguish the actual health status of the Three Gorges Reservoir (TGR) than physicochemical assessments and have a clear response to human activity. Then, taking this reliable Me-IBI as a supervised label, we compared the impact of selecting different numbers of features and SML algorithms on the stability and predictive performance of the model for predicting ecological conditions in multiple seasons using taxonomy-free eDNA metabarcoding data. We discovered that even with a small number of features, different SML algorithms can establish a stable model and obtain excellent predictive performance. Finally, we proposed a four-step strategy for standardized routine biomonitoring using SML tools. Our study firstly explores the general applicability problem of the taxonomy-free eDNA-SML approach and establishes a solid foundation for the large-scale and standardized biomonitoring application.

Probiotics mitigate kidney damage after exposure to Sri Lanka's local groundwater from chronic kidney disease with uncertain etiology (CKDu) prevalent area in zebrafish.

Groundwater in Sri Lanka, contaminated with environmental toxins, is suspected to potentially induce chronic kidney disease of uncertain etiology (CKDu) in humans. This study aims to elucidate the potential mitigating effects of probiotics on kidney damage induced by exposure to this local groundwater (LW) in zebrafish. We used zebrafish as a model organism and exposed them to local groundwater to evaluate the risk of CKDu. Probiotics were then added at a concentration of 108 colony-forming units per milliliter (CFU/mL). Our findings revealed that exposure to local groundwater resulted in abnormalities, such as tail deletion and spinal curvature in zebrafish larvae. However, the addition of probiotics mitigated these effects, improving the hatching rate, heart rate, length, weight, deformity rate, survival rate, and abnormal behavior of zebrafish. It also positively influenced the differential expression levels of kidney development and immunity-related genes (dync2h1, foxj1, pkd2, gata3, slc20a1, il1ß, and lyso). Furthermore, exposure to LW decreased both the diversity and abundance of microbiota in zebrafish larvae. However, treatment with probiotics, such as L. plantarum and L. rhamnosus partially restored the disrupted gut microbiota and significantly impacted the cellular process pathways of the microbial community, as determined by KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis. In conclusion, this study highlights the risks associated with Sri Lanka's local groundwater from a CKDu prevalent area and confirms the beneficial effects of different probiotics. These findings may provide new insights into bacterial function in host kidney health.

Biomacromolecule-based nanocarrier strategies to deliver plant-derived bioactive components for cancer treatment: A recent review.

The quest for safe chemotherapy has attracted researchers to explore anticancer potential of herbal medicines. Owing to upsurging evidence of herbal drug's beneficial effects, hopes are restored for augmenting survival rates in cancer patients. However, phytoconstituents confronted severe limitations in terms of poor absorption, low-stability, and low bioavailability. Along with toxicity issues associated with phytoconstituents, quality control and limited regulatory guidance also hinder the prevalence of herbal medicines for cancer therapy. Attempts are underway to exploit nanocarriers to circumvent the limitations of existing and new herbal drugs, where biological macromolecules (e.g., chitosan, hyaluronic acid, etc.) are established highly effective in fabricating nanocarriers and cancer targeting. Among the discussed nanocarriers, liposomes and micelles possess properties to cargo hydro- and lipophilic herbal constituents with surface modification for targeted delivery. Majorly, PEG, transferrin and folate are utilized for surface modification to improve bioavailability, circulation time and targetability. The dendrimer and carbon nanotubes responded in high-loading efficiency of phytoconstituent; whereas, SLN and nanoemulsions are suited carriers for lipophilic extracts. This review emphasized unveiling the latent potential of herbal drugs along with discussing on extended benefits of nanocarriers-based delivery of phytoconstituents for safe cancer therapy owing to enhanced clinical and preclinical outcomes without compromising safety.

Ultra-sensitive detection of ecologically rare fish from eDNA samples based on the RPA-CRISPR/Cas12a technology.

Environmental DNA (eDNA) research holds great promise for improving biodiversity science and conservation efforts by enabling worldwide species censuses in near real-time. Current eDNA methods face challenges in detecting low-abundance ecologically important species. In this study, we used isothermal recombinase polymerase amplification (RPA)-CRISPR/Cas detection to test Ctenopharyngodon idella. RPA-CRISPR-Cas12a detected 6.0 eDNA copies/µL within 35 min. Ecologically rare species were identified in the Three Gorges Reservoir Area (TGRA) using functional distinctiveness and geographical restrictiveness, with seven fish species (9%) classified as potentially ecologically rare including three species in this investigation. RPA-CRISPR/Cas12a-FQ outperformed high-throughput sequencing (HTS) and qPCR in detecting low-abundance eDNA (AUC = 0.883∗∗). A significant linear correlation (R2 = 0.682∗∗) between RPA-CRISPR/Cas12a-FQ and HTS quantification suggests its potential for predicting species abundance and enhancing eDNA-based fish biodiversity monitoring. This study highlights the value of RPA-CRISPR/Cas12a-FQ as a tool for advancing eDNA research and conservation efforts.

Engineering bacteriophages for enhanced host range and efficacy: insights from bacteriophage-bacteria interactions.

Bacteriophages, the most abundant organisms on earth, have the potential to address the rise of multidrug-resistant bacteria resulting from the overuse of antibiotics. However, their high specificity and limited host range can hinder their effectiveness. Phage engineering, through the use of gene editing techniques, offers a means to enhance the host range of bacteria, improve phage efficacy, and facilitate efficient cell-free production of phage drugs. To engineer phages effectively, it is necessary to understand the interaction between phages and host bacteria. Understanding the interaction between the receptor recognition protein of bacteriophages and host receptors can serve as a valuable guide for modifying or replacing these proteins, thereby altering the receptor range of the bacteriophage. Research and development focused on the CRISPR-Cas bacterial immune system against bacteriophage nucleic acids can provide the necessary tools to promote recombination and counter-selection in engineered bacteriophage programs. Additionally, studying the transcription and assembly functions of bacteriophages in host bacteria can facilitate the engineered assembly of bacteriophage genomes in non-host environments. This review highlights a comprehensive summary of phage engineering methods, including in-host and out-of-host engineering, and the use of high-throughput methods to understand their role. The main aim of these techniques is to harness the intricate interactions between bacteriophages and hosts to inform and guide the engineering of bacteriophages, particularly in the context of studying and manipulating the host range of bacteriophages. By employing advanced high-throughput methods to identify specific bacteriophage receptor recognition genes, and subsequently introducing modifications or performing gene swapping through in-host recombination or out-of-host synthesis, it becomes possible to strategically alter the host range of bacteriophages. This capability holds immense significance for leveraging bacteriophages as a promising therapeutic approach against antibiotic-resistant bacteria.

Microstructures and Fatigue Properties of High-Strength Low-Alloy Steel Prepared through Submerged-Arc Additive Manufacturing.

Submerged arc additive manufacturing (SAAM) is a viable technique for manufacturing large and complex specialized parts used in structural applications. At present, manufacturing high-strength low-alloy steel T-branch pipe through SAAM has not been reported. This paper uses this technology to manufacture low-alloy structural steel parts. The microstructures of the samples were characterized, which revealed that they were mainly composed of polygonal ferrites. The tensile properties in the horizontal and vertical directions of deposits were studied. Results show that the horizontal tensile strength of deposits was quite close to the vertical one, while the elongation rate in the vertical direction was obviously lower than that in the horizontal direction. Fatigue results indicate that the strain fatigue limit of high-strength low-alloy steel samples in vertical direction was 0.24%. The fatigue fractures of fatigue samples of deposits showed multi-source crack initiation characteristics and the crack propagation regions exhibited typical fatigue striations, so the final instantaneous fracture region showed a ductile fracture. Fatigue performance is very important for the safe service of structural parts, but there is a lack of relevant research on this additive manufacturing part. The results of this paper may support the popularization of the SAAM for high-strength low-alloy steel T-branch pipe.

Recurrence of sigmoid colon cancer-derived anal metastasis: A case report and review of literature.

BACKGROUND: Distant metastasis of colorectal cancer to the anus is very rare, with only 30 related cases published in PubMed thus far. Therefore, recurrence of colorectal cancer derived anus metastases is rarely seen and less presented. CASE SUMMARY: Here we report an 80-year-old male patient who underwent radical resection for sigmoid colon cancer in January 2010 and another surgery for anal fistula resection in December 2010. Postoperative pathology of the anal fistula revealed a metastatic moderately differentiated adenocarcinoma. The patient subsequently received chemotherapy and radiotherapy. In May 2020, after the patient reported symptoms of anal swelling and pain, computed tomography and magnetic resonance imaging revealed a perianal abscess. Perianal mass biopsy was performed, and the postoperative pathological diagnosis was metastatic moderately differentiated adenocarcinoma. CONCLUSION: This case highlights that there is a risk of recurrence of anal metastasis of colorectal cancer even after 10 years of follow-up. We also reviewed the literature and discuss potential mechanisms for anal metastasis of colorectal cancer, thus providing some suggestions for treatment of these cases.

Comparative Study of Hydrochemical Classification Based on Different Hierarchical Cluster Analysis Methods.

Traditional methods for hydrochemical analyses are effective but less diversified, and are constrained to limited objects and conditions. Given their poor accuracy and reliability, they are often used in complement or combined with other methods to solve practical problems. Cluster analysis is a multivariate statistical technique that extracts useful information from complex data. It provides new ideas and approaches to hydrogeochemical analysis, especially for groundwater hydrochemical classification. Hierarchical cluster analysis is the most widely used method in cluster analysis. This study compared the advantages and disadvantages of six hierarchical cluster analysis methods and analyzed their objects, conditions, and scope of application. The six methods are: The single linkage, complete linkage, median linkage, centroid linkage, average linkage (including between-group linkage and within-group linkage), and Ward's minimum-variance. Results showed that single linkage and complete linkage are unsuitable for complex practical conditions. Median and centroid linkages likely cause reversals in dendrograms. Average linkage is generally suitable for classification tasks with multiple samples and big data. However, Ward's minimum-variance achieved better results for fewer samples and variables.

Multilevel Resistive Switching Memory Based on a CH3NH3PbI 3-xClx Film with Potassium Chloride Additives.

High-quality CH3NH3PbI 3-xClx (MAPIC) films were prepared using potassium chloride (KCl) as an additive on indium tin oxide (ITO)-coated glass substrates using a simple one-step and low-temperature solution reaction. The Au/KCl-MAPIC/ITO/glass devices exhibited obvious multilevel resistive switching behavior, moderate endurance, and good retention performance. Electrical conduction analysis indicated that the resistive switching behavior of the KCl-doped MAPIC films was primarily attributed to the trap-controlled space-charge-limited current conduction that was caused by the iodine vacancies in the films. Moreover, the modulations of the barrier in the Au/KCl-MAPIC interface under bias voltages were thought to be responsible for the resistive switching in the carrier injection trapping/detrapping process.

Changes of plasma BNP and copeptin levels in patients with CHF of different degrees and their correla‐tion with cardiac function class / 心血管康复医学杂志

Objective :To explore changes of plasma levels of BNP and copeptin (CPT) in patients with chronic heart failure (CHF) of different degrees and their correlation with cardiac function class .Methods :A total of 150 CHF patients treated in our hospital from Feb 2015 to Feb 2017 ,were selected as CHF group .Another 45 healthy volun‐ teers undergoing physical examination in our hospital simultaneously were regarded as healthy control group .Plasma BNP and CPT levels were compared between two groups .According to NYHA cardiac function class ,CHF group was further divided into class II group (n＝48) ,class III group (n＝51) and class IV group (n＝51).Plasma levels of BNP and CPT etc .were measured and compared among three subgroups .Correlation among BNP ,CPT levels and cardiac function class were analyzed in CHF patients .Results :Compared with healthy control group ,there were significant rise in plasma levels of BNP and CPT in CHF group , P＝ 0.001 both .Compared with class II group , there were significant rise in plasma levels of BNP [ (1002.82 ± 101.33) pmol／L vs.(1515.05 ± 166.73) pmol／L vs.(2102.36 ± 227.32) pmol／L] ,CPT [ (6.51 ± 1.01 ) pmol／L vs.(9.28 ± 2.89 ) pmol／L vs .(14.03 ± 3.72 ) pmol／L] and LVEDd [ (51.51 ± 4. 01) mm vs.(59.28 ± 6.19) mm vs.(64. 03 ± 5.72) mm] ,and significant reduc‐tion in LVEF [ (50. 82 ± 6. 33)% vs.(45.05 ± 4.73)% vs.(41.36 ± 2.32)%] in class III group and class IV group , and plasma levels of BNP ,CPT ,LVEDd in class IV group were significantly higher than those of class III group , and LVEF was significantly lower than that of class III group , P＝0. 001 all.Spearman correlation analysis indicated that plasma levels of BNP and CPT were significant positively correlated with cardiac function class in CHF patients ( r＝0.320 ,0.302 , P＝0.009 ,0.011).Conclusion :Along with CHF aggravates ,the plasma levels of BNP and CPT significantly rise .Cardiac function class is significant positively correlated with plasma levels of BNP and CPT .

Effects of Notoginsenoside R1 on Expression of Myocardial Inflammation-related Factors and Metalloproteinase in Atrial Fibrillation Rats / 中山大学学报(医学科学版)

@#Abstract: 【Objective】To study the effects of notoginsenoside R1 on the levels of intercellular adhesion molecule- 1（ICAM- 1），tumor necrosis factor- α （TNF- α），metalloproteinase- 2 （MMP- 2） and metalloproteinase- 2 inhibitor （TIMP- 2）in rats with atrial fibrillation in order to explore the mechanism of notoginsenoside R1 on the preventing and treating atrial fibrillation. 【Methods】 102 rats were randomly divided into control group ，atrial fibrillation group and notoginsenoside R1 group，with 34 rats in each group. The rat model of atrial fibrillation was established by injection of acetylcholine-calcium chloride into the tail vein. The rats in the notoginsenoside R1 group were intraperitoneally injected with 2 mL of notoginsenoside R1. ECG was used to measure the duration of atrial fibrillation. Masson staining was used to observe the degree of myocardial fibrosis. Immunohistochemistry was used to detect the expression of MMP-2 and TIMP-2 in atrial tissue. The serum ICAM-1，TNF-α，MMP-2 and TIMP-2 levels were determined by enzyme-linked immunosorbent assay（ELISA）. The levels of ICAM-1，TNF-α and type I collagen in atrial tissue were determined by Western blotting.【Results】Before the treatment of notoginsenoside R1 ，there was no significant difference in the duration of atrial fibrillation between the two groups（P > 0.05）. After treatment，the duration of atrial fibrillation in the notoginsenoside R1 group［（6.37±2.02）s］was lower than that in the pre-treatment and the atrial fibrillation groups（P < 0.05）. Masson staining showed：the amount of atrial fibrillar collagen fibers in control group was normal；a large number of collagen fibers were seen in the atrial myocytes of atrial fibrillation group；the patchy and punctate collagen fibers were seen in the atrial myocytes of notoginsenoside R1 group. Compared with control group，the serum levels of ICAM-1，TNF- α and MMP-2 ［（137.52±16.59）10-6 g/L，（14.25±1.08）10-6 g/L，（435.26±17.63）10-9 g/L；（109.25±14.62）10-6 g/L ，（12.31±1.27）10-6 g/L， （288.47±15.52）10-9 g/L］were increased（P < 0.05），the serum levels of TIMP-2 levels［（3 541.27±331.24）10-9 g/L ； （3 975.46 ± 313.24）10- 9 g/L］was decreased（P < 0.05），the atrial tissue ICAM- 1，TNF- α and type I collagen levels （0.23±0.07 ，0.51±0.09 、0.63±0.14 ；0.15±0.06 ，0.22±0.07 ，0.27±0.12）were increased（P < 0.05），the atrial tissue MMP-2 protein optical density（0.35±0.07；0.18±0.06）was increased（P < 0.05），the atrial tissue TIMP-2 protein optical density（0.11±0.04；0.18±0.03）was decreased（P < 0.05）in atrial fibrillation group and the notoginsenoside R1 group； Compared with atrial fibrillation group，the levels of serum ICAM-1，TNF- α and MMP-2 were decreased（P < 0.05）， the levels of serum TIMP-2 was increased（P < 0.05），the atrial tissue ICAM- 1 ，TNF- α and type I collagen levels were decreased（P < 0.05），the density of MMP-2 protein in atrial tissue was decreased（P < 0.05），and the optical density of TIMP-2 protein in atrial tissue was increased（P < 0.05）in the rats in notoginsenoside R1 group.【Conclusion】 Notoginsenoside R1 can prevent and treat atrial fibrillation by reducing the levels of ICAM- 1，TNF- α and MMP-2 and increasing the levels of TIMP-2 in serum and atrial tissue of rats with atrial fibrillation.

Intermolecular Dehydrative Coupling and Intramolecular Cyclization of Ruthenium Vinylidene Complexes Formed from Aromatic Propynes Containing Carbonyl Functionalities.

A remarkable intermolecular dehydrative coupling reaction with the formation of a C-C bond was found for the vinylidene complex 2 a, yielding the dinuclear bisvinylidene complex 4 a. Complex 2 a containing 1-hydroxyindan moiety was first formed from the reaction of o-propynyl benzaldehyde 1 a with [Ru]-Cl ([Ru]=Cp(PPh3 )2 Ru) by a cyclization process. For analogous aldehyde 1 b containing an additional 1,3-dioxolane group on the aryl ring, similar intermolecular coupling yields the dinuclear bisvinylidene complex 4 b. However, the fluoro group on the aryl ring in aldehyde 1 c inhibits the coupling reaction, giving only the vinylidene complex 2 c. For the reactions of [Ru]-Cl in MeOH with compounds 1 f, 1 g and 1 h, each with a ketone functionality, cyclization gives vinylidene complexes 2 f, 2 g and 2 h, respectively. However, no similar intermolecular coupling was observed, instead, the intramolecular dehydration yields 8 f, 8 g and 8 h, respectively. In CDCl3 , catalytic cyclization is observed for the o-propynylphenyl ketone 1 h with [Ru]-Cl at 50 °C giving the isochromene products 14 h. Furthermore, treatment of the o-propynylaryl α,ß-unsaturated ketones 1 k-m and 1 n with [Ru]-Cl in MeOH affords the corresponding vinylidene complexes 10 k-m and 11 n each with 1-benzosuberone moiety in the presence of NH4 PF6 . These intramolecular cyclization products were formed by the addition of Cß onto the terminal carbon of the alkene moiety. All these reaction products were characterized by spectroscopic methods. In addition, structures of complexes 4 a, and 10 l were confirmed by single crystal X-ray diffraction analysis.

Pb speciation in rare earth minerals and use of entropy and fuzzy clustering methods to assess the migration capacity of Pb during mining activities.

Ionic rare earth mining is of strategic importance in China; however, the heavy metal pollution it causes is of great concern, both at home and abroad. Data on Pb speciation at a rare earth mine were used to analyse the migration capacity of Pb during the process of ore leaching. The major factors thought to influence the migration capacity of Pb, including the clay mineral content, soil pH, oxidation-reduction potential, organic matter content, and cation exchange capacity (CEC), were quantified. Entropy and fuzzy clustering methods were used to identify the most predictive factors. The results showed that the clay mineral content of the soil exerts the strongest influence on the migration capacity of Pb in rare earth mines; the other factors demonstrated relatively weak influences on the transport processes. The results obtained from the classification of Pb per the potential migration index (PMI) approximated those obtained from fuzzy clustering, and the results of entropy analyses were consistent with those of fuzzy clustering. Thus, the methods upon which the proposed model is based are suitable for predicting the migration capacity of Pb in ore during the mining of ionic rare earth minerals.

Hydrogen bonding and fluorous weak interactions in the non-isomorphous {4,4'-bis[(2,2,3,3-tetrafluoropropoxy)methyl]-2,2'-bipyridine-κ2N,N'}dibromidopalladium and -platinum complexes.

The polyfluorinated title compounds, [MBr2(C18H16F8N2O2)] or [4,4'-(HCF2CF2CH2OCH2)2-2,2'-bpy]MBr2, (1) (M = Pd and bpy is bipyridine) and (2) (M = Pt), have -CH(α)2OCH(ß)2CF2CF2H side chains with methylene H-atom donors at the α and ß sites, and methine H-atom donors at the terminal sites, in addition to aromatic H-atom donors. In contrast to the original expectation of isomorphous structures, (1) crystallizes in the space group C2/c and (2) in P21/n, with similar unit-cell volumes and Z = 4. The asymmetric unit of (1) is one half of the molecule, which resides on a crystallographic twofold axis. Both (1) and (2) display stacking of the molecules, indicating a planar (bpy)MBr2 skeleton in each case. The structure of (1) exhibits columns with C-H(ß)...Br hydrogen bonds between consecutive layers which conforms to a static (ß,ß) linkage between layers. In the molecular plane, (1) shows double C-H(α)...Br hydrogen bonds self-repeating along the b axis, the planar molecules being connected into infinite belts. Compound (2) has no crystallographic symmetry and forms π-dimer pairs as supermolecules, which then stack parallel to the a axis. The π-dimer-pair supermolecules exhibit (Pt-)Br...Br(-Pt) contacts [3.6937 (7) Å] to neighbouring π-dimer pairs crosslinking the columns. The structure of (2) reveals many C-H...F(-C) interactions between F atoms and aromatic C-H groups, in addition to those between F atoms and methylene C-H groups.