Pilot-scale study of innovative mechanically-enhanced dynamic composting for treating kitchen waste

This study introduced a novel mechanically-enhanced dynamic composting (MEDC) method for treating kitchen waste (KW) through partial-mixing and stratified fermentation. A pilot test varied aeration frequencies (AF) to refine control parameters and explore the maturation mechanism. Results showed that a moderate AF (10 min/4 h) achieved optimal efficiency, with a compost germination index of 123 % within 15 d. Moderate AF enhanced the growth of Corynebacterium_1 (25.4 %) and Saccharomonospora (10.5 %) during the low-temperature stage and Bacillus growth (91.3 %) during the maturation stage. Moreover, it enhanced microbial interactions (with an average degree of 19.9) and promoted substrate degradation and transformation, expediting heating and maturation. Multivariate dimensionality reduction analysis showed the MEDC accomplished rapid composting through stratified composting, dividing the reactor into distinct functional zones: feeding, low-temperature, high-temperature, and maturation. This enabled efficient microorganism enrichment and material degradation, expediting KW decomposition and maturation. This study offers a promising alternative for accelerated KW composting.

Application of deep learning in the diagnosis and evaluation of ulcerative colitis disease severity

Background

Achieving endoscopic and histological remission is a critical treatment objective in ulcerative colitis (UC). Nevertheless, interobserver variability can significantly impact overall assessment performance.

Objectives

We aimed to develop a deep learning algorithm for the real-time and objective evaluation of endoscopic disease activity and prediction of histological remission in UC.

Design

This is a retrospective diagnostic study.

Methods

Two convolutional neural network (CNN) models were constructed and trained using 12,257 endoscopic images and biopsy results sourced from 1124 UC patients who underwent colonoscopy at a single center from January 2018 to December 2022. Mayo Endoscopy Subscore (MES) and UC Endoscopic Index of Severity Score (UCEIS) assessments were conducted by two experienced and independent reviewers. Model performance was evaluated in terms of accuracy, sensitivity, and positive predictive value. The output of the CNN models was also compared with the corresponding histological results to assess histological remission prediction performance.

Results

The MES-CNN model achieved 97.04% accuracy in diagnosing endoscopic remission of UC, while the MES-CNN and UCEIS-CNN models achieved 90.15% and 85.29% accuracy, respectively, in evaluating endoscopic severity of UC. For predicting histological remission, the CNN models achieved accuracy and kappa values of 91.28% and 0.826, respectively, attaining higher accuracy than human endoscopists (87.69%).

Conclusion

The proposed artificial intelligence model, based on MES and UCEIS evaluations from expert gastroenterologists, offered precise assessment of inflammation in UC endoscopic images and reliably predicted histological remission.

Denitrification fractionates N and O isotopes of nitrate following a ratio independent of carbon sources in freshwaters

The stable isotope technique has been used in tracking nitrogen cycling processes, but the isotopic characteristics are influenced by environmental conditions. To better understand the variability of nitrate isotopes in nature, we investigated the influence of organic carbon sources on isotope fractionation characteristics during microbial denitrification. Denitrifying cultures were inoculated with freshwater samples and enriched with five forms of organic compounds, that is, acetate, citrate, glucose, cellobiose, and leucine. Though the isotope enrichment factors of nitrogen and oxygen (15 ε and 18 ε) changed with carbon sources, 18 ε/15 ε always followed a proportionality near 1. Genome-centred metagenomics revealed the enrichment of a few populations, such as Pseudomonas, Enterobacter, and Atlantibacter, most of which contained both NapA- and NarG-type nitrate reductases. Metatranscriptome showed that both NapA and NarG were expressed but to different extents in the enrichments. Furthermore, isotopic data collected from a deep reservoir was analysed. The results showed δ18 O- and δ15 N-nitrate did not correlate in the surface water where nitrification was active, but 18 ε/15 ε followed a proportionality of 1.05 ± 011 in deeper waters (≥ 12 m) where denitrification controlled the nitrate isotope. The independence of 18 ε/15 ε from carbon sources provides an opportunity to determine heterotrophic denitrification and helps the interpretation of nitrate isotopes in freshwaters.

Patterns of the lymph node metastasis and the influencing factors in esophagogastric junction cancers

OBJECTIVE

A retrospective analysis of 214 cases of esophagogastric junction cancers (EGJCs) in Kunming, Yunnan Province, was conducted to investigate the lymph node metastasis (LNM) pattern for EGJCs and its associated risk factors (RFs), as well as the predictive value of common clinical metabolic indicators for it.

METHODS

The clinical data of 214 patients diagnosed with EGJCs by electronic gastroscope and postoperative pathology between 2013 and 2021 at the First Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital, and the Second Affiliated Hospital of Kunming Medical University were retrospectively examined. Preoperative gastroscopy, imaging, biochemical data, and postoperative pathological findings analysis in EGJCs were statistically analyzed to determine the RFs of LNM.

RESULTS

At presentation, 92.5% of EGJCs were progressive malignancies, including 68.2% LNMs, 79.5% abdominal lymph nodes (ALN), 20.1% mediastinal lymph nodes (MLN), and 27.1% distal metastases. The ratio of Siewert subtypes was approximately 2:11:7 (type I to type II to type III). In terms of age, disease duration at initial presentation, history, tumor length, pathological biopsy histology, degree of differentiation, depth of infiltration, LNM status, MLN metastasis, and surgical route, the differences between the three Siewert subgroups were statistically significant (p < 0.05). Multifactor analysis revealed that the proportion of patients aged <65 at the time of consultation was significantly more significant in Siewert II and Siewert III than in Siewert I. Significantly more patients than in Siewert I had <2 months of disease duration at the time of their first consultation. The proportion of patients with tumors <3 Cm in length was significantly higher than in Siewert I. For the RFs analysis of LNM, Siewert staging (type I and type II), depth of infiltration, and distant metastasis were the independent RFs for LNM. The depth of infiltration and family history of the tumor were the independent RFs for ALN metastasis, and the number of lymph nodes cleared in the abdominal and mediastinal regions was a protective factor for ALN metastasis. Siewert staging(type I and type II), infiltration depth, invasion of the esophagus by the tumor, tumor length, and distant metastasis were independent risk factors for MLN metastasis. Among the metabolic variables evaluated, BMI was an independent RF for LNM, fasting glucose was an independent RF for ALN metastasis, and triacylglycerol was a protective factor for MLN metastasis.

CONCLUSIONS

EGJCs are frequently advanced at presentation, characterized by minimal differentiation and a high incidence of LNM. The Siewert subtype is concentrated near the stomach. Different Siewert subtypes exhibit distinct clinicopathological characteristics. LNM and MLN metastasis risk are considerably higher in type I tumors compared to types II and III. There is a strong correlation between LNM and MLN metastasis and distant metastasis in EGJCs, so Siewert I is more aggressive and associated with a worse prognosis. EGJCs have numerous RFs associated with LNM, and there are similarities and differences in the RFs affecting their LNM, ALN metastases, and MLN metastases, which are related to their unique anatomical features. There is a close relationship between metabolic factors and EGJCs with some predictive value.

Promoter hypermethylation and comprehensive regulation of ncRNA lead to the down-regulation of ZNF880, providing a new insight for the therapeutics and research of colorectal cancer

The human genome encodes more than 350 kinds of Krüppel-associated box (KRAB) domain-containing zinc-finger proteins (KZFPs), KRAB-type ZNF transcription factor family (KZNF) plays a vital role in gene regulatory networks. The KZNF family members include a large number of highly homologous genes, gene subtypes and pseudogenes, and their expression has a high degree of tissue specificity and precision. Due to the high complexity of its regulatory network, the KZNF gene family has not been researched in sufficient, and the role of its members in the occurrence of cancer is mostly unexplored. In this study, ZNF880 was significantly associated with overall survival (OS) and disease-free survival (DFS) in colorectal carcinoma (CRC) patients. Low ZNF880 expression resulted in shorter OS and DFS. Combined with Colon adenocarcinoma (COAD) and Rectum adenocarcinoma (READ) data collection in the TCGA database, we found that ZNF880 was significantly down-regulated in CRC. Further analysis of the sequence variation of ZNF880 in CRC showed that ZNF880 accumulated a large number of SNV in the C2H2 domain and KRAB domain, while promoter region of ZNF880 also showed high methylation in COAD and READ. Combined with the Cbioportal and TIMER databases, the expression of mutant ZNF880 was significantly lower in COAD compared to the wild type. Simultaneously, the lncRNA-miRNA-ZNF880 ceRNA regulatory network was constructed through co-expression and miRNAs target gene prediction, demonstrating the precision of the ZNF880 regulatory network. In addition, the decreased expression of ZNF880 caused the significant immune infiltration decreases of CD8 + cells in COAD. In contrast, the immune infiltration of CD4 + cells and macrophages in COAD is positively correlated with ZNF880. Finally, through protein-protein interaction (PPI) network analysis and transcription factor target gene prediction, we screened out the genes most likely to be related to the function of ZNF880. CENPK, IFNGR2, REC8 and ZBTB17 were identified as the most closely functioning genes with ZNF880, which may indicate that ZNF880 has important links with the formation of cell centromere, tumor immunity, cell cycle and other pathways closely related to the occurrence of CRC. These studies show that the down-regulation of ZNF880 gene is closely related to CRC, and the targeted change of the expression of its regulatory molecules (miRNA and lncRNA) may be a new perspective for CRC treatment.

The OPAQUE1/DISCORDIA2 myosin XI is required for phragmoplast guidance during asymmetric cell division in maize

Formative asymmetric divisions produce cells with different fates and are critical for development. We show the maize (Zea mays) myosin XI protein, OPAQUE1 (O1), is necessary for asymmetric divisions during maize stomatal development. We analyzed stomatal precursor cells before and during asymmetric division to determine why o1 mutants have abnormal division planes. Cell polarization and nuclear positioning occur normally in the o1 mutant, and the future site of division is correctly specified. The defect in o1 becomes apparent during late cytokinesis, when the phragmoplast forms the nascent cell plate. Initial phragmoplast guidance in o1 is normal; however, as phragmoplast expansion continues o1 phragmoplasts become misguided. To understand how O1 contributes to phragmoplast guidance, we identified O1-interacting proteins. Maize kinesins related to the Arabidopsis thaliana division site markers PHRAGMOPLAST ORIENTING KINESINs (POKs), which are also required for correct phragmoplast guidance, physically interact with O1. We propose that different myosins are important at multiple steps of phragmoplast expansion, and the O1 actin motor and POK-like microtubule motors work together to ensure correct late-stage phragmoplast guidance.

Complications after endoscopic submucosal dissection for early colorectal cancer (Review)

Colorectal cancer (CRC) is a gastrointestinal malignancy that seriously threatens human life and health, resulting in a heavy disease burden. Endoscopic submucosal dissection (ESD) is widely used in clinical practice and is an effective treatment for early CRC (ECC). Colorectal ESD is a challenging operation, and the incidence of postoperative complications is relatively high because of the thin intestinal wall and limited space for endoscopic operations. Systematic reports on the postoperative complications of colorectal ESD, such as fever, bleeding and perforation, from both China and elsewhere are lacking. In the present review, progress in research on postoperative complications after ESD for ECC is summarized.

Reducing nitrogen loss during kitchen waste composting using a bioaugmented mechanical process with low pH and enhanced ammonia assimilation

Exploring the regulation of nitrogen transformation in bioaugmented mechanical composting (BMC) process for rural kitchen waste (KW) is essential to avoid the "not-in-my-backyard" phenomenon caused by nitrogen loss. Herein, nitrogen transformation and loss in BMC versus conventional pile composting (CPC) of KW were compared. The results showed that the total nitrogen loss in the BMC was 6.87-39.32 % lower than that in the CPC. The main pathways to prevent nitrogen loss in the BMC were reducing NH₃ by avoiding a sharp increase in pH followed by transforming the preserved NH₄⁺-N into recalcitrant nitrogen reservoir via enhanced ammonia assimilation. The enriched thermophilic bacteria with mineralization capacities (e.g., Bacillus and Corynebacterium) during rapid dehydration and heating in the BMC accumulated organic acids and easy-to-use carbon sources, which could lead to lower pH and ammonia assimilation enhancement, respectively. This study provides new ideas for formulating low-cost nitrogen conservation strategies in decentralized KW composting.

Alterations in metabolome and microbiome signatures provide clues to the role of antimicrobial peptide KT2 in ulcerative colitis

Introduction

Ulcerative colitis (UC) is an inflammatory disease of the intestinal tract with unknown etiology. Both genetic and environmental factors are involved in the occurrence and development of UC. Understanding changes in the microbiome and metabolome of the intestinal tract is crucial for the clinical management and treatment of UC.

Methods

Here, we performed metabolomic and metagenomic profiling of fecal samples from healthy control mice (HC group), DSS (Dextran Sulfate Sodium Salt) -induced UC mice (DSS group), and KT2-treated UC mice (KT2 group).

Results and Discussion

In total, 51 metabolites were identified after UC induction, enriched in phenylalanine metabolism, while 27 metabolites were identified after KT2 treatment, enriched in histidine metabolism and bile acid biosynthesis. Fecal microbiome analysis revealed significant differences in nine bacterial species associated with the course of UC, including Bacteroides, Odoribacter, and Burkholderiales, which were correlated with aggravated UC, and Anaerotruncus, Lachnospiraceae, which were correlated with alleviated UC. We also identified a disease-associated network connecting the above bacterial species with UC-associated metabolites, including palmitoyl sphingomyelin, deoxycholic acid, biliverdin, and palmitoleic acid. In conclusion, our results indicated that Anaerotruncus, Lachnospiraceae, and Mucispirillum were protective species against DSS-induced UC in mice. The fecal microbiomes and metabolomes differed significantly among the UC mice and KT2-treated and healthy-control mice, providing potential evidence for the discovery of biomarkers of UC.

Polarly localized WPR proteins interact with PAN receptors and the actin cytoskeleton during maize stomatal development

Polarization of cells prior to asymmetric cell division is crucial for correct cell divisions, cell fate, and tissue patterning. In maize (Zea mays) stomatal development, the polarization of subsidiary mother cells (SMCs) prior to asymmetric division is controlled by the BRICK (BRK)-PANGLOSS (PAN)-RHO FAMILY GTPASE (ROP) pathway. Two catalytically inactive receptor-like kinases, PAN2 and PAN1, are required for correct division plane positioning. Proteins in the BRK-PAN-ROP pathway are polarized in SMCs, with the polarization of each protein dependent on the previous one. As most of the known proteins in this pathway do not physically interact, possible interactors that might participate in the pathway are yet to be described. We identified WEAK CHLOROPLAST MOVEMENT UNDER BLUE LIGHT 1 (WEB1)/PLASTID MOVEMENT IMPAIRED 2 (PMI2)-RELATED (WPR) proteins as players during SMC polarization in maize. WPRs physically interact with PAN receptors and polarly accumulate in SMCs. The polarized localization of WPR proteins depends on PAN2 but not PAN1. CRISPR-Cas9-induced mutations result in division plane defects in SMCs, and ectopic expression of WPR-RFP results in stomatal defects and alterations to the actin cytoskeleton. We show that certain WPR proteins directly interact with F-actin through their N-terminus. Our data implicate WPR proteins as potentially regulating actin filaments, providing insight into their molecular function. These results demonstrate that WPR proteins are important for cell polarization.

[Review on the assessment model of nutrient recycling with agricultural residues treatment technologies]

The technology for nutrient resource utilization of agricultural residues is crucial to realizing a circular agricultural economy. The assessment model provides essential support to optimize nutrient recovery and treatment technologies. We specifically summarized research progress in the assessment framework of agricultural residues nutrient recycling technology, assessment models and evaluation indicators, data sources of models and their uncertainty analysis, and the application scale of models. We found that process mathematical models and industrial eco-logy models are the common nutrient flow assessment models. Process mathematical and industrial ecology models differed greatly in terms of the reliability of assessment results and the simulation scale. The former mainly focused at laboratory or pilot scale, with higher accuracy. The latter could achieve multi-scale simulation from microscopic to macroscopic and had higher uncertainty, due to the way its data were obtained. Finally, we provided an outlook on the research on the assessment model of agricultural residues nutrient resource utilisation technology. In order to achieve accurate assessment of waste resource utilisation technology in agricultural production systems at the regional scale, a reliable model framework and database should be established by combining process mathematical models with industrial ecology models. Meanwhile, we should carry out research on model expansion at the geographical scales of factory scale, farm scale, village scale, township scale, and regional scale.

Survival benefit of surgical resection for stage IV gastric cancer: A SEER-based propensity score-matched analysis

BACKGROUND

Gastric cancer (GC) is a major malignancy worldwide, and its incidence and mortality rate are increasing year by year. Clinical guidelines mainly use palliative drug combination therapy for stage IV gastric cancer. In accordance with some small sample studies, surgery can prolong survival. There is no uniform treatment plan for stage IV gastric cancer. This study focused on collecting evidence of the survival benefit of cancer-directed surgery (CDS) for patients with stage IV gastric cancer by analyzing data from a large sample.

METHODS

Data on patients with stage IV gastric cancer diagnosed between 2010 and 2015 was extracted and divided into CDS and no-CDS groups using the large dataset in the Surveillance, Epidemiology, and End Results (SEER) database. With bias between the two groups minimized by propensity score matching (PSM), the prognostic role of CDS was studied by the Cox proportional risk model and Kaplan-Meier.

RESULTS

A total of 6,284 patients with stage IV gastric cancer were included, including 514 patients with CDS who were matched with no-CDS patients according to propensity score (1:1), resulting in the inclusion of 432 patients each in the CDS and no-CDS groups. The results showed that CDS appeared to prolong the median survival time for stage IV gastric cancer (from 6 months to 10 months). Multifactorial analysis showed that poorly differentiated tumors (grades III-IV) significantly affected patient survival, and chemotherapy was a protective prognostic factor.

CONCLUSION

The findings support that CDS can provide a survival benefit for stage IV gastric cancer. However, a combination of age, underlying physical status, tumor histology, and metastatic status should be considered when making decisions about CDS, which will aid in clinical decision-making.

Evidence for Assimilatory Nitrate Reduction as a Previously Overlooked Pathway of Reactive Nitrogen Transformation in Estuarine Suspended Particulate Matter

Suspended particulate matter (SPM) contributes to the loss of reactive nitrogen (Nr) in estuarine ecosystems. Although denitrification and anaerobic ammonium oxidation in SPM compensate for the current imbalance of global nitrogen (N) inputs and sinks, it is largely unclear whether other pathways for Nr transformation exist in SPM. Here, we combined stable isotope measurements with metagenomics and metatranscriptomics to verify the occurrence of dissimilatory nitrate reduction to ammonium (DNRA) in the SPM of the Pearl River Estuary (PRE). Surprisingly, the conventional functional genes of DNRA (nirBD) were abundant and highly expressed in SPM, which was inconsistent with a low potential rate. Through taxonomic and comparative genomic analyses, we demonstrated that nitrite reductase (NirBD) in conjunction with assimilatory nitrate reductase (NasA) performed assimilatory nitrate reduction (ANR) in SPM, and diverse alpha- and gamma-proteobacterial lineages were identified as key active heterotrophic ANR bacteria. Moreover, ANR was predicted to have a relative higher occurrence than denitrification and DNRA in a survey of Nr transformation pathways in SPM across the PRE spanning 65 km. Collectively, this study characterizes a previously overlooked pathway of Nr transformation mediated by heterotrophic ANR bacteria in SPM and has important implications for our understanding of N cycling in estuaries.

Rare primary rectal mucosa-associated lymphoid tissue lymphoma with curative resection by endoscopic submucosal dissection: A case report and review of literature

BACKGROUND

Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) occurs in approximately 9% of non-Hodgkin B-cell lymphomas. The gastrointestinal tract is the most commonly affected site of the extranodal forms of primary non-Hodgkin’s lymphomas. However, it rarely occurs within the rectum, and at present, there is no consensus on its diagnosis and treatment at this site.

CASE SUMMARY

We report a rare laterally spreading tumour-like rectal MALT lymphoma case in which the diagnosis and the depth of infiltration were determined by magnifying endoscopy and ultrasonic endoscopy. Then, the lesion was en bloc resected by endoscopic submucosal dissection (ESD) alone. The lesion was confirmed as MALT lymphoma by haematoxylin and eosin staining, immunohistochemical staining and gene arrangement analysis. Surveillance exams have indicated a 2-year disease-free survival for this patient.

CONCLUSION

We report a rare primary rectal MALT lymphoma that was curable with resection by ESD. ESD is a safe and effective therapeutic option for rectal MALT lymphoma.

The Distinguishing Bacterial Features From Active and Remission Stages of Ulcerative Colitis Revealed by Paired Fecal Metagenomes

Ulcerative colitis (UC) is a serious chronic intestinal inflammatory disease, with an increased incidence in recent years. The intestinal microbiota plays a key role in the pathogenesis of UC. However, there is no unified conclusion on how the intestinal microbiota changes. Most studies focus on the change between UC patients and healthy individuals, rather than the active and remission stage of the same patient. To minimize the influences of genetic differences, environmental and dietary factors, we studied the intestinal microbiota of paired fecal samples from 42 UC patients at the active and remission stages. We identified 175 species of microbes from 11 phyla and found no difference of the alpha and beta diversities between the active and remission stages. Paired t-test analysis revealed differential microbiota at levels of the phyla, class, order, family, genus, and species, including 13 species with differential abundance. For example, CAG-269 sp001916005, Eubacterium F sp003491505, Lachnospira sp000436475, et al. were downregulated in the remission, while the species of Parabacteroides distasonis, Prevotellamassilia sp900540885, CAG-495 sp001917125, et al. were upregulated in the remission. The 13 species can effectively distinguish the active and remission stages. Functional analysis showed that the sporulation and biosynthesis were downregulated, and the hydrogen peroxide catabolic process was upregulated in remission of UC. Our study suggests that the 13 species together may serve as a biomarker panel contributing to identify the active and remission stages of UC, which provides a valuable reference for the treatment of UC patients by FMT or other therapeutic methods.

KT2 alleviates ulcerative colitis by reducing Th17 cell differentiation through the miR-302c-5p/STAT3 axis

BACKGROUND

The abnormal differentiation of Th17 cells aggravates ulcerative colitis (UC). Antimicrobial peptides (AMPs) exert pivotal protection functions against UC. KT2 is a cationic AMP that mediates colon cancer development. However, KT2's function in UC remains unclear.

METHODS

The UC mouse model was induced by administering 2.5% dextran sulfate sodium, and the mice were given an enema of KT2. KT2's function in UC and Th17 cell differentiation in vivo was evaluated through various molecular experiments. The KT2's function in Th17 cell differentiation in vitro was evaluated by the proportion of CD4⁺ IL-17⁺ T cells, IL-17 levels, and RORγt expression levels. Meanwhile, the mechanism was assessed through quantitative real-time PCR, various loss-of-function assays, and dual-luciferase reporter gene assay.

RESULTS

KT2 restrained Th17 cell differentiation in both in vivo and in vitro UC models and slowed the UC process. KT2 elevated miR-302c-5p expression, as well as restrained Th17 cell differentiation by increasing miR-302c-5p. Meanwhile, miR-302c-5p interacted with the signal transducer and activator of transcription 3 (STAT3) and negatively regulated its expression. Furthermore, our data revealed that KT2 restrained the activation of STAT3 by elevating miR-302c-5p, thereby inhibiting Th17 cell differentiation.

CONCLUSION

KT2 alleviates UC by repressing Th17 cell differentiation through the miR-302c-5p/STAT3 axis.

Elevation of NO3--N from biochar amendment facilitates mitigating paddy CH4 emission stably over seven years

Biochar application into paddy is an improved strategy for addressing methane (CH₄) stimulation of straw biomass incorporation. Whereas, the differentiative patterns and mechanisms on CH₄ emission of straw biomass and biochar after long years still need to be disentangled. Considering economic feasibility, a seven-year of field experiment was conducted to explore the long-term CH₄ mitigation effect of annual low-rate biochar incorporation (RSC, 2.8 t ha^-1), with annual rice straw incorporation (RS, 8 t ha^-1) and control (CK, with no biochar or rice straw amendment incorporation) as a comparation. Results showed that RSC mitigated CH₄ emission while RS stimulated CH₄ significantly (p < 0.05) and stably over 7 experimental years compared with CK. RSC mitigated 14.8-46.7% of CH₄ emission compared with CK. In comparison to RSC, RS increased 111-950.5% of CH₄ emission during 7 field experimental years. On the 7th field experimental year, pH was significantly increased both in RS and RSC treatment (p < 0.05). RSC significantly (p < 0.05) increased soil nitrate (NO₃^--N) compared with RS while RS significantly (p < 0.05) increased dissolved carbon (DOC) compared to RSC. Soil NO₃^--N inhibition on methanogens and promotion on methanotrophs activities were verified by laboratory experiment, while soil pH and DOC mainly promoted methanogens abundance. Significantly (p < 0.05) increased DOC and soil pH enhanced methanogens growth and stimulated CH₄ emission in RS treatment. Higher soil NO₃^--N content in RSC than CK and RS contributed to CH₄ mitigation. Soil NO₃^--N and DOC were identified as the key factors differentiating CH₄ emission patterns of RS and RSC in 2019. Collectively, soil NO₃^--N impacts on CH₄ flux provide new ideas for prolonged effect of biochar amendment on CH₄ mitigation after years.

Stability of biochar in mineral soils: Assessment methods, influencing factors and potential problems

Amendment of biochar into mineral soils has been reported a promising strategy for carbon sequestration and greenhouse gas mitigation due to its high stability. Currently, most studies on the stability of biochar are mainly focused on the assessment methods and influencing factors. The assessment methods include qualitative evaluation of physical and chemical properties, and utilization of kinetic mineralization models on the basis of laboratory incubation. As a result, these assessment methods are difficult to accurately reflect the real impact of the interaction between biochar and environmental factors. This article reviews the existing assessment methods, influencing factors, and the impact of environmental aging on the stability of biochar. It is found that under the influence of environmental factors, existing assessment methods are likely to overestimate the stability of biochar in mineral soils. Therefore, more emphases should be laid on the analyses of the deficiencies in the existing assessment methods on the stability of biochar in the consideration of practical applications. Long-term field experiment is strongly recommended to establish a more accurate assessment model on biochar stability for the evaluation of its carbon sequestration potential in mineral soils.

Carbohydrate degradation contributes to the main bioheat generation during kitchen waste biodrying process: A pilot study

Biodrying is a promising method for processing kitchen waste (KW) with high moisture content into reusable solid recovered fuels (SRFs). During biodrying, a large amount of bioheat generated from biodegradation of biochemical components results in KW dehydration. However, the degradation rules of these components and their contribution to the bioheat in KW biodrying have not been systematically clarified. Here, a pilot experiment was performed to investigate the variations in biochemical components, hydrolase activities, and bioheat generation during three successive cycles of biodrying processes. Results showed that KW could be rapidly converted into SRFs with low calorific values of 6705-7062 kJ/kg and moisture content of 31.26%-35.21%. Analyses of hydrolase activities and mean fluorescence intensity suggested that the biodrying process pioneered the degradation of lipids and proteins in the warming stages, while carbohydrates (i.e. amylum, celluloses, etc.) underwent rapid decomposition in a large extent in the high-temperature and cooling stages. Carbohydrates with minimal difficulty in degradation, contributed 73.37%-89.92% to the total degradation mass and 59.23%-60.80% to the bioheat source during the three-cycle biodrying process. The generated bioheat was 4.32-4.56 times the amount of the theoretical heat used for water removal, indicating that internal bioheat could significantly enhance water evaporation and was sufficient for the expected water removal mass. Therefore, the evaluation of the main components to bioheat generation and its utilization efficiency makes a prominent contribution that can greatly clarify the conversion of KW biodrying into SRFs in order to efficiently promote renewable bioenergy and support the bioeconomy.

Methane oxidation activity inhibition via high amount aged biochar application in paddy soil

Fresh biochar application has been recommended as an effective strategy to mitigate methane emissions from paddy soil due to its role in promoting potential methane oxidation (PMO). However, little is known about the effect of biochar on PMO after long-term aging. Here, a laboratory incubation experiment was performed to gain insight into the combined effects of biochar characteristics on soil PMO during the biochar aging process. Biochar samples aged with an HNO₃/H₂SO₄ mixture (1:3) were prepared and added at 22.5 and 2.8 t ha^-1 to paddy soil. Mixed acid with a dilution of 10- 40% indicated the aging process in paddy field properly. Smaller biochar particles, smoother surface, higher surface area and porosity were observed with the increase of mixed acid ratio. Carboxylic functional groups (COOR) on biochar surface increased accompanied with biochar aging process. Aged biochar application at 22.5 t ha^-1 inhibited paddy soil PMO, which mainly caused from the increased COOR groups induced NH₄⁺-N inhibition for PMO. Increased soil NH₄⁺-N inhibited PMO by limiting the growth of methanotrophs and nitrifiers due to decreased soil pH. In contrast, 2.8 t aged biochar ha^-1 application showed no significant difference on PMO compared with control. Our results indicated that aged biochar exerted in paddy soil have limited effect on mitigating methane emissions from paddy soil in the long term.

Mitigating methane emission via annual biochar amendment pyrolyzed with rice straw from the same paddy field

To develop an economic and sustainable biochar application strategy for mitigating methane emission from paddy fields, a four-year field experiment was conducted to compare two biochar amendment methods. The annual low (AL) rate pyrolyzed biochar returning method used the same amount of biochar as was harvested from rice straw in the field, 2.8 t ha^-1 yr^-1. The high single (HS) biochar returning method consisted of a single application of 22.5 t ha^-1 biochar only in the first year, 2015. Our results showed that the AL biochar returning strategy prevailed over the HS strategy in mitigating methane emission from paddy fields. On average, AL and HS could reduce methane emissions by 41% and 38.25% in four years, respectively. Methane accumulation per unit rice production was 45.8% and 43.1% in AL and HS, respectively. AL showed a stable effect on mitigating methane emission over four successive years, which resulted from the continuously increasing methanotrophs due to annual fresh biochar application. Aged biochar weakened the promotion of methanotrophs, leading to lower methane reduction rates in HS than in AL in the 4 years. Our results indicate that AL is a highly sustainable strategy for methane mitigation in paddy fields due to its high efficiency, practical operation, and economical acceptance.

Biochar amendment pyrolysed with rice straw increases rice production and mitigates methane emission over successive three years

A sustainable biochar strategies on increasing crop yield and mitigating CH₄ emissions over successive years is unknown. Thus, on-site equivalent rice straw biochar-returning (ERSC, biochar at 2.8 t ha^-1 annual) were compared with on-site equivalent rice straw- returning (RS, rice straw at 8 t ha^-1 annual) and high application rate biochar-returning (RSCH, biochar at 22.5 t ha^-1 only in the first year). The RS and RSCH treatments increased rice production by 10.1% and 11.8% on average, respectively. The ERSC treatment continually increased rice production by 8.0%, 1.6% and 7.3% in three successive years. The ERSC treatment had a cumulative effect on the soil nutrients phosphorus (P), potassium (K), and magnesium (Mg), as well as increasing total carbon (TC) and total nitrogen (TN) and continuously reducing the effect of soil available aluminum (Al). The RS treatment significantly promoted CH₄ emissions while the ERSC treatment reduced methane emissions by 43%, 31% and 30% and the RSCH treatment reduced methane emissions by 52%, 22% and14% in three successive years. Compared with RSCH, ERSC showed the best long-term stable effect on methane emission mitigation in three successive years. This might result from the fact that fresh biochar promoted anaerobic oxidation of methane. This research gives us scientific evidence that an on-site equivalent rice straw biochar-returning strategy may be a promising method for sustaining rice production and mitigating methane emissions.

Temporal physicochemical changes and transformation of biochar in a rice paddy: Insights from a 9-year field experiment

Biochar application to soil has attracted extensive attention worldwide due to its carbon (C) sequestration and fertility-enhancing properties. However, the lack of biochar accumulation in highly disturbed agroecosystems challenges the perceived long-term stability of biochars in soil. This 9-year field experiment was conducted in rice paddy fields to understand the temporal degradation of biochars produced from two contrasting feedstocks (rice straw vs. bamboo) at a high temperature (600 °C). Obvious physical alterations, surface oxidation, and transformation of condensed aromatic C occurred in biochars in the disturbed paddy field with frequent redox cycles. Increase in O/C atomic ratio, levels of high-temperature-sensitive degradable components, H/C ratio, and linear alkyl-C content were observed, which were indicative of time-dependent molecular changes and degradative transformation of biochars. Biochar degradation was characterized by the loss of labile C at an early stage and the degradation of aromatic C at a later stage. Based on the massive loss of C content in biochars (10.3-11.8%) and considerable degradation of aromatic C (5.0-8.7%) in 9 years, we argue that current biphasic C dynamic models probably overestimate the stability of biochars in agroecosystems such as rice paddy fields. Long-term field experiments (>5 years) are required to assess biochar's potential for C sequestration. This study provides long-term field data regarding the temporal changes in biochar physicochemical properties, which may facilitate the development of a robust assessment scheme on the long-term persistence of biochars in agroecosystems.

Biochar drives microbially-mediated rice production by increasing soil carbon

The effects of an on-site biomass (rice straw) equivalent biochar-returning strategy (RSC) on rice yield, soil nutrients and bacterial community composition were examined in a four-year field trial (2013-2016) conducted in a paddy field in south China. Three treatments were set up including annual on-site biomass return (RS, rice straw at 8 t ha^-1 yr^-1), annual on-site biomass equivalent biochar-return (RSC, rice straw biochar at 2.8 t ha^-1 yr^-1 with a 35 % carbonization rate) and control (CK, no rice straw or biochar added). Results showed that a low rate of biochar application (RSC) could significantly increase rice yield in four successive years. The increase in rice yield was mainly attributed to the increase in soil potassium and magnesium contents resulting from the presence of the unique surface functional groups of biochar. As a result of biochar amendment, soil bacterial cooperative relationships were improved in the RSC, compared to those in the RS treatment. Our study indicated that RSC might be promoted as a promising strategy to enhance rice productivity and soil fertility in a sustainable way.

Arabidopsis ADF5 promotes stomatal closure by regulating actin cytoskeleton remodeling in response to ABA and drought stress

Stomatal movement plays an essential role in plant responses to drought stress, and the actin cytoskeleton and abscisic acid (ABA) are two important components of this process. Little is known about the mechanism underlying actin cytoskeleton remodeling and the dynamic changes occurring during stomatal movement in response to drought stress/ABA signaling. Actin-depolymerizing factors (ADFs) are conserved actin severing/depolymerizing proteins in eukaryotes, and in angiosperms ADFs have evolved actin-bundling activity. Here, we reveal that the transcriptional expression of neofunctionalized Arabidopsis ADF5 was induced by drought stress and ABA treatment. Furthermore, we demonstrated that ADF5 loss-of-function mutations increased water loss from detached leaves, reduced plant survival rates after drought stress, and delayed stomatal closure by regulating actin cytoskeleton remodeling via its F-actin-bundling activity. Biochemical assays revealed that an ABF/AREB transcription factor, DPBF3, could bind to the ADF5 promoter and activate its transcription via the ABA-responsive element core motif ACGT/C. Taken together, our findings indicate that ADF5 participates in drought stress by regulating stomatal closure, and may also serve as a potential downstream target of the drought stress/ABA signaling pathway via members of the ABF/AREB transcription factors family.

UV modification of biochar for enhanced hexavalent chromium removal from aqueous solution

This study was conducted to understand the effects of ultraviolet (UV) irradiation on the physicochemical properties and the hexavalent chromium (Cr(VI)) removal ability of biochar. Structural and morphological analysis showed that UV irradiation increased the specific surface area of biochar and added a large amount of oxygen-containing functional groups (e.g., carboxyl, lactonic, and hydroxyl) to biochar's surface. Batch sorption experimental results showed that UV-modified biochar (UVBC) produced at the pyrolysis temperature of 300 °C, the irradiated time of 24 h, and the irradiation distance of 40 mm exhibited excellent Cr(VI) removal ability (from 1.11 mg/g for BC to 20.04 mg/g for UVBC, a 18.1-fold increase). The adsorption kinetics and adsorption isotherm data agreed well with the pseudo-second-order model and Freundlich model, respectively. Experimental and modeling results suggest that the oxygen-containing functional groups and specific surface areas of biochars were notably increased by UV irradiation, which enhanced Cr(VI) adsorption by surface complexation. X-ray photoelectron spectroscopy (XPS) analysis of UVBC before and after reaction with Cr(VI) showed that reduction occurred during Cr(VI) adsorption. The energy consumption of UV modification is 2.7 MJ per gram of UVBC produced, which is comparable to that in activated carbon. The results showed that the method of UV modification of biochar is a very novel and effective method for the adsorption of Cr(VI) in solution.

Synthesis and characterization of an iron-impregnated biochar for aqueous arsenic removal

The iron (Fe)-impregnated biochar (FBC), fabricated via thermal pyrolysis of corn straw treated with FeCl₃, was investigated for the sorption characteristics and mechanisms of aqueous arsenate removal. Structural and morphological analysis showed that large quantity of iron oxide particles tightly grew within the porous matrix of biochar (BC) through iron-impregnation. Batch sorption experimental results showed that the composite, with larger surface area, more functional groups, and greater thermal stability, exhibited excellent As(V) adsorption efficiency of 6.80mg/g compared to 0.017mg/g for unmodified BC (a 400-fold increase). The adsorption kinetics data were fitted well by pseudo second-order model, and sorption isotherms of As(V) were simulated well by both Freundlich and Langmuir models. XRD and FTIR analysis suggested that electrostatic attraction and precipitation were dominant mechanisms for As(V) sorption. The As(V)-loaded FBC could be easily separated from the solution by a magnet at the end of the sorption experiment. The FBC showed excellent re-sorption capacity, which account for about 70% removal efficiency for the second and third reuse in As(V) sorption. Results from this study demonstrated the promise of FBC composite as an efficient, low-cost, environmentally friendly, and regenerable adsorbent for As(V) remediation.

CAPSULE

FBC showed enhanced As(V) sorption capacity, excellent re-sorption capacity, and could be easily separated by a magnet.

Identification and validation of colorectal neoplasia-specific methylation biomarkers based on CTCF-binding sites

To date, the sensitivity of currently available biomarkers based on the methylation of gene promoters is suboptimal for detecting adenomas and early-stage colorectal cancer (CRC). We aimed to develop biomarkers with methylated DNA binding sites of the multifunctional transcriptional factor CTCF for early detection of CRC. Using combined analyses of genome-wide occupation and the methylation profile of CTCF-binding sites, we identified candidate CTCF-binding sites. Then, we applied methylation-sensitive high-resolution melting (MS-HRM) and mass spectrometry analysis to screen and validate these candidate sites in diverse sample sets. We identified a set of colorectal neoplasia-specific biomarkers with robust performance. The top five biomarkers were selected and recommended for early detection of colorectal neoplasia. All of the five novel biomarkers exhibited a more robust discriminatory performance than that by BMP3 and NDRG4, two currently acknowledged robust methylation biomarkers. When the five new biomarkers were considered as a marker panel and tumor-positive was defined as having two or more (of the five) positive biomarkers, the marker panel could achieve a sensitivity of 91.67% for adenomas, 97.44% for Stage I CRC, 94.06% for Stage II CRC, 93.62% for Stage III CRC, and 93.54% for total colorectal tumors with a specificity of 94.05%. To our knowledge, this is the first study for colorectal neoplasia-specific methylation biomarkers based on CTCF-binding sites. Using a similar strategy, CTCF-binding sites could be potentially developed into biomarkers for other tumors. In summary, this study opens a new area in developing biomarkers for tumor prevention and treatment.

Fimbrins 4 and 5 Act Synergistically During Polarized Pollen Tube Growth to Ensure Fertility in Arabidopsis

The germination and polar growth of pollen are prerequisite for double fertilization in plants. The actin cytoskeleton and its binding proteins play pivotal roles in pollen germination and pollen tube growth. Two homologs of the actin-bundling protein fimbrin, AtFIM4 and AtFIM5, are highly expressed in pollen in Arabidopsis and can form distinct actin architectures in vitro, but how they co-operatively regulate pollen germination and pollen tube growth in vivo is largely unknown. In this study, we explored their functions during pollen germination and polar growth. Histochemical analysis demonstrated that AtFIM4 was expressed only after pollen grain hydration and, in the early stage of pollen tube growth, the expression level of AtFIM4 was low, indicating that it functions mainly during polarized tube growth, whereas AtFIM5 had high expression levels in both pollen grains and pollen tubes. Atfim4/atfim5 double mutant plants had fertility defects including reduced silique length and seed number, which were caused by severe defects in pollen germination and pollen tube growth. When the atfim4/atfim5 double mutant was complemented with the AtFIM5 protein, the polar growth of pollen tubes was fully rescued; however, AtFIM4 could only partially restore these defects. Fluorescence labeling showed that loss of function of both AtFIM4 and AtFIM5 decreased the extent of actin filament bundling throughout pollen tubes. Collectively, our results revealed that AtFIM4 acts co-ordinately with AtFIM5 to organize and maintain normal actin architecture in pollen grains and pollen tubes to fulfill double fertilization in plants.

Higher-Ordered Actin Structures Remodeled by Arabidopsis ACTIN-DEPOLYMERIZING FACTOR5 Are Important for Pollen Germination and Pollen Tube Growth

Dynamics of the actin cytoskeleton are essential for pollen germination and pollen tube growth. ACTIN-DEPOLYMERIZING FACTORs (ADFs) typically contribute to actin turnover by severing/depolymerizing actin filaments. Recently, we demonstrated that Arabidopsis subclass III ADFs (ADF5 and ADF9) evolved F-actin-bundling function from conserved F-actin-depolymerizing function. However, little is known about the physiological function, the evolutional significance, and the actin-bundling mechanism of these neofunctionalized ADFs. Here, we report that loss of ADF5 function caused delayed pollen germination, retarded pollen tube growth, and increased sensitive to latrunculin B (LatB) treatment by affecting the generation and maintenance of actin bundles. Examination of actin filament dynamics in living cells revealed that the bundling frequency was significantly decreased in adf5 pollen tubes, consistent with its biochemical functions. Further biochemical and genetic complementation analyses demonstrated that both the N- and C-terminal actin-binding domains of ADF5 are required for its physiological and biochemical functions. Interestingly, while both are atypical actin-bundling ADFs, ADF5, but not ADF9, plays an important role in mature pollen physiological activities. Taken together, our results suggest that ADF5 has evolved the function of bundling actin filaments and plays an important role in the formation, organization, and maintenance of actin bundles during pollen germination and pollen tube growth.

Plant Actin-Depolymerizing Factors Possess Opposing Biochemical Properties Arising from Key Amino Acid Changes throughout Evolution

Functional divergence in paralogs is an important genetic source of evolutionary innovation. Actin-depolymerizing factors (ADFs) are among the most important actin binding proteins and are involved in generating and remodeling actin cytoskeletal architecture via their conserved F-actin severing or depolymerizing activity. In plants, ADFs coevolved with actin, but their biochemical properties are diverse. Unfortunately, the biochemical function of most plant ADFs and the potential mechanisms of their functional divergence remain unclear. Here, in vitro biochemical analyses demonstrated that all 11 ADF genes in Arabidopsis thaliana exhibit opposing biochemical properties. Subclass III ADFs evolved F-actin bundling (B-type) function from conserved F-actin depolymerizing (D-type) function, and subclass I ADFs have enhanced D-type function. By tracking historical mutation sites on ancestral proteins, several fundamental amino acid residues affecting the biochemical functions of these proteins were identified in Arabidopsis and various plants, suggesting that the biochemical divergence of ADFs has been conserved during the evolution of angiosperm plants. Importantly, N-terminal extensions on subclass III ADFs that arose from intron-sliding events are indispensable for the alteration of D-type to B-type function. We conclude that the evolution of these N-terminal extensions and several conserved mutations produced the diverse biochemical functions of plant ADFs from a putative ancestor.

Identification of Environmental Factors Associated with Inflammatory Bowel Disease in a Southwestern Highland Region of China: A Nested Case-Control Study

BACKGROUND

The aim of this study was to examine environmental factors associated with inflammatory bowel disease (IBD) in Yunnan Province, a southwestern highland region of China.

METHODS

In this nested case-control study, newly diagnosed ulcerative colitis (UC) cases in 2 cities in Yunnan Province and Crohn's disease (CD) cases in 16 cities in Yunnan Province were recruited between 2008 and 2013. Controls were matched by geography, sex and age at a ratio of 1:4. Data were collected using the designed questionnaire. Conditional logistic regression models were used to estimate adjusted odds ratios (ORs).

RESULTS

A total of 678 UC and 102 CD cases were recruited. For UC, various factors were associated with an increased risk of developing UC: dietary habits, including frequent irregular meal times; consumption of fried foods, salty foods and frozen dinners; childhood factors, including intestinal infectious diseases and frequent use of antibiotics; and other factors, such as mental labor, high work stress, use of non-aspirin non-steroidal anti-inflammatory drugs and allergies (OR > 1, p < 0.05). Other factors showed a protective effect: such as consumption of fruits, current smoking, physical activity, and drinking tea (OR < 1, p < 0.05). For CD, appendectomy and irregular meal times increased the disease risk (OR >1, p < 0.05), whereas physical activity may have reduced this risk (OR < 1, p < 0.05).

CONCLUSIONS

This study is the first nested case-control study to analyze the association between environmental factors and IBD onset in a southwestern highland region of China. Certain dietary habits, lifestyles, allergies and childhood factors may play important roles in IBD, particularly UC.

Gelsolin-Like Domain 3 Plays Vital Roles in Regulating the Activities of the Lily Villin/Gelsolin/Fragmin Superfamily

The villin/gelsolin/fragmin superfamily is a major group of Ca2+-dependent actin-binding proteins (ABPs) involved in various cellular processes. Members of this superfamily typically possess three or six tandem gelsolin-like (G) domains, and each domain plays a distinct role in actin filament dynamics. Although the activities of most G domains have been characterized, the biochemical function of the G3 domain remains poorly understood. In this study, we carefully compared the detailed biochemical activities of ABP29 (a new member of this family that contains the G1-G2 domains of lily ABP135) and ABP135G1-G3 (which contains the G1-G3 domains of lily ABP135). In the presence of high Ca2+ levels in vitro (200 and 10 μM), ABP135G1-G3 exhibited greater actin severing and/or depolymerization and nucleating activities than ABP29, and these proteins had similar actin capping activities. However, in the presence of low levels of Ca2+ (41 nM), ABP135G1-G3 had a weaker capping activity than ABP29. In addition, ABP29 inhibited F-actin depolymerization, as shown by dilution-mediated depolymerization assay, differing from the typical superfamily proteins. In contrast, ABP135G1-G3 accelerated F-actin depolymerization. All of these results demonstrate that the G3 domain plays specific roles in regulating the activities of the lily villin/gelsolin/fragmin superfamily proteins.

Annexin5 plays a vital role in Arabidopsis pollen development via Ca2+-dependent membrane trafficking

The regulation of pollen development and pollen tube growth is a complicated biological process that is crucial for sexual reproduction in flowering plants. Annexins are widely distributed from protists to higher eukaryotes and play multiple roles in numerous cellular events by acting as a putative "linker" between Ca2+ signaling, the actin cytoskeleton and the membrane, which are required for pollen development and pollen tube growth. Our recent report suggested that downregulation of the function of Arabidopsis annexin 5 (Ann5) in transgenic Ann5-RNAi lines caused severely sterile pollen grains. However, little is known about the underlying mechanisms of the function of Ann5 in pollen. This study demonstrated that Ann5 associates with phospholipid membrane and this association is stimulated by Ca2+ in vitro. Brefeldin A (BFA) interferes with endomembrane trafficking and inhibits pollen germination and pollen tube growth. Both pollen germination and pollen tube growth of Ann5-overexpressing plants showed increased resistance to BFA treatment, and this effect was regulated by calcium. Overexpression of Ann5 promoted Ca2+-dependent cytoplasmic streaming in pollen tubes in vivo in response to BFA. Lactrunculin (LatB) significantly prohibited pollen germination and tube growth by binding with high affinity to monomeric actin and preferentially targeting dynamic actin filament arrays and preventing actin polymerization. Overexpression of Ann5 did not affect pollen germination or pollen tube growth in response to LatB compared with wild-type, although Ann5 interacts with actin filaments in a manner similar to some animal annexins. In addition, the sterile pollen phenotype could be only partially rescued by Ann5 mutants at Ca2+-binding sites when compared to the complete recovery by wild-type Ann5. These data demonstrated that Ann5 is involved in pollen development, germination and pollen tube growth through the promotion of endomembrane trafficking modulated by calcium. Our results provide reliable molecular mechanisms that underlie the function of Ann5 in pollen.

Clinical characteristics of colorectal neoplasms: A retrospective analysis of 260 cases

AIM: To investigate the clinical characteristics of colorectal neoplasms so as to provide the basis for clinical diagnosis and treatment.

METHODS: The clinical data for 260 patients with primary colorectal neoplasms diagnosed surgically and pathologically in 2010 at our hospital were analyzed retrospectively. The clinical features for colorectal neoplasms and the association of smoking, drinking and past medical history with tumor progression were analyzed.

RESULTS: Male/female ratio was 1.24:1, and the average age was 61.73 ± 11.56 years. The incidences by tumor site ranked in descending order were the rectum, the sigmoid colon, the ascending, transverse and descending colons. Synchronized carcinomas of the colon and rectum were found in 8 cases. Approximately 64.23% of rectal neoplasms were located within 8 cm to the anus. The average length was significantly longer in male cases than in female cases (8.22 cm ±3.35 cm vs 7.08 cm ± 2.09 cm, t = 2.20, P = 0.03). Bloody stools was the main symptom of left-sided colonic and rectal neoplasms, while abdominal pain and abdominal distension were main symptoms of right-sided colonic neoplasms. The positive rate of fecal occult blood test (OBT) was 80.43%. The ratio of cases in Dukes stage A was 18.85%. Tumor differentiation degree was negatively correlated with age (r = -0.145, P = 0.019). The incidence rate of right-sided colonic neoplasms among cholecystectomy patients was higher than left-sided ones but the difference was not statistically significant (P > 0.05). The incidences of metastasis and infiltration among essential hypertension patients were lower (both P < 0.05).

CONCLUSION: Digital rectal examination (DRE) and OBT are two important methods for finding colorectal neoplasms. Bloody stools and abdominal pain, abdominal distension are the main symptoms of right- and left-sided colonic neoplasms, respectively. There is an increased trend in early diagnosis. Age, cholecystectomy and essential hypertension may relate to pathogenesis and development of colorectal neoplasms.

Heterotopic gastric mucosa in the upper and middle esophagus: 126 cases of gastroscope and clinical characteristics

BACKGROUND/AIMS

In this retrospective study, we aimed to investigate the prevalence of heterotopic gastric mucosa (HGM) in the upper and middle esophagus, to identify its macroscopic characteristics and evaluate clinical features.

METHODOLOGY

One hundred and twenty-six patients (82 males, 44 females; mean age 43.08 ± 12.84 years, range 15-81) with HGM in the upper and middle esophagus diagnosed by gastroscopy and biopsies were admitted to this retrospective study. Disease histories of all patients were carefully inquired, especially the associated complaints including discomfort of throat, heartburn or dysphagia, etc.

RESULTS

The prevalence was 0.21%. Patch size ranged between 5-20mm, mean diameter was 7.5 ± 3.7mm; 80 cases appeared as a single patch; 96.83% had the patch in the upper esophagus. Male gender was predominant (male:female ratio, 1.86), but age was not significant. The mean distance from the incisors to the patch was 18.83 ± 2.23cm and 17.20 ± 2.48cm in the male and the female respectively, with a significant difference (t=3.749, p<0.001). In 39 of 126 patients (26 male, 13 female), the esophageal and laryngopharyngeal symptoms were remarkable. Twelve were associated with other diseases of the esophagus. There were no correlations to esophageal symptom, gender, age, location, quantity or diameter. Among the 126 cases, 29 patients were associated with other esophageal diseases.

CONCLUSIONS

HGM patches in the esophagus should not be overlooked during endoscopy because they may lead to esophageal symptoms and even important complications in relation to their acid secretions.

Expression and clinical significance of PLUNC protein in nasal polyp and chronic sinusitis tissue

We conducted a study to validate the expression of PLUNC (palate, lung, and nasal epithelial clone) protein in nasal polyp and chronic sinusitis tissue by immunohistochemistry. We also explored the relationship between the intensity of positive immunohistochemical staining for PLUNC protein and postoperative therapeutic efficacy. Our study population consisted of 34 patients with nasal polyps and 30 with chronic sinusitis who had undergone surgical treatment, along with 18 healthy controls who did not undergo surgery. All samples were stained according to the streptavidin-peroxidase immunohistochemical method to examine PLUNC protein expression. The surgical patients were evaluated for clinical therapeutic efficacy 6 months postoperatively. The association between efficacy and the intensity of PLUNC protein positivity was examined by the Spearman rank correlation analysis. Intensity was rated as either +++(>50% positive cells), ++ (26 to 50% positive cells),+ (≤25% positive cells), or -(no positive cells). We found that the most common levels of PLUNC positivity were + in the patients with nasal polyps, +++ in the patients with chronic sinusitis, and ++ in the controls (p< 0.01). Analysis of the Spearman rank correlation indicated that the intensity of PLUNC protein expression was significantly correlated with postoperative therapeutic efficacy (p< 0.001). We conclude that PLUNC protein is an essential factor in the innate defense mechanism of the nasal mucosa. The immunohistochemical staining of PLUNC protein could have clinical benefit in terms of predicting therapeutic efficacy and outcomes in patients with nasal polyps or chronic sinusitis.

Expression and Clinical Significance of Plunc Protein in Nasal Polyp and Chronic Sinusitis Tissue

We conducted a study to validate the expression of PLUNC (palate, lung, and nasal epithelial clone) protein in nasal polyp and chronic sinusitis tissue by immunohistochemistry. We also explored the relationship between the intensity of positive immunohistochemical staining for PLUNC protein and postoperative therapeutic efficacy. Our study population consisted of 34 patients with nasal polyps and 30 with chronic sinusitis who had undergone surgical treatment, along with 18 healthy controls who did not undergo surgery. All samples were stained according to the streptavidin-peroxidase immunohistochemical method to examine PLUNC protein expression. The surgical patients were evaluated for clinical therapeutic efficacy 6 months postoperatively. The association between efficacy and the intensity of PLUNC protein positivity was examined by the Spearman rank correlation analysis. Intensity was rated as either +++ (>50% positive cells), ++ (26 to 50% positive cells), + (≤25% positive cells), or - (no positive cells). We found that the most common levels of PLUNC positivity were + in the patients with nasalpolyps, +++ in the patients with chronic sinusitis, and ++ in the controls (p < 0.01). Analysis of the Spearman rank correlation indicated that the intensity of PLUNC protein expression was significantly correlated with postoperative therapeutic efficacy (p < 0.001). We conclude that PLUNC protein is an essential factor in the innate defense mechanism of the nasal mucosa. The immunohistochemical staining of PLUNC protein could have clinical benefit in terms of predicting therapeutic efficacy and outcomes in patients with nasalpolyps or chronic sinusitis.

Arabidopsis vacuolar H+-ATPase (V-ATPase) B subunits are involved in actin cytoskeleton remodeling via binding to, bundling, and stabilizing F-actin

Vacuolar H(+)-ATPase (V-ATPase) is a membrane-bound multisubunit enzyme complex composed of at least 14 different subunits. The complex regulates the physiological processes of a cell by controlling the acidic environment, which is necessary for certain activities and the interaction with the actin cytoskeleton through its B and C subunits in both humans and yeast. Arabidopsis V-ATPase has three B subunits (AtVAB1, AtVAB2, and AtVAB3), which share 97.27% sequence identity and have two potential actin-binding sites, indicating that these AtVABs may have crucial functions in actin cytoskeleton remodeling and plant cell development. However, their biochemical functions are poorly understood. In this study, we demonstrated that AtVABs bind to and co-localize with F-actin, bundle F-actin to form higher order structures, and stabilize actin filaments in vitro. In addition, the AtVABs also show different degrees of activities in capping the barbed ends but no nucleating activities, and these activities were not regulated by calcium. The functional similarity and differences of the AtVABs implied that they may play cooperative and distinct roles in Arabidopsis cells.

Phantom experimental study on microwave ablation with a water-cooled antenna

Microwave ablation therapy using a water-cooled antenna was studied experimentally in a phantom. The development of the heating pattern induced by the microwave antenna was determined from the thermocouple-measured temperature field, and the influence of the cooling water flow within the antenna on temperature distribution and heating pattern was investigated. The shape of the heating pattern was pear-like, and the enlarging rate of the heating pattern decreased with heating time. Because of strong cooling effect, the heating pattern in the region with Z < 0 (where Z = 0 represents the position of radiator, Z < 0 and Z > 0 represent the backward direction of the antenna with cooling water and forward direction without water, respectively) was smaller in diameter than that with Z > 0, and the heating pattern with Z < 0 was slightly reduced when the velocity of the cooling water increased. The highest ablative temperature occurred with Z > 0 decreasing. Finally, the specific absorption rate distribution was also determined and investigated analytically. The present results can be helpful in clinical ablation therapy practice and will be applicable to multiple applicators for surgical planning.

Thermal characteristics of microwave ablation in the vicinity of an arterial bifurcation

PURPOSE

The objective of this research was to reveal the thermal characteristics of microwave ablations in the vicinity of an arterial bifurcation.

METHODS

The temperature distribution after microwave heating of a liver-like material in the close proximity of an arterial bifurcation was simulated using the finite element method. Coupled fluid flow and solid heat transfer were taken into consideration and a three-dimensional analysis was performed. An experimentally determined SAR (specific absorption rate) generated by the absorption of microwaves in liver-like material was used in the analysis instead of utilizing electromagnetic calculations. Several different tests of time-controlled ablations with varying distances between the microwave antenna and the bifurcation were performed and detailed temperature distributions near the bifurcation were obtained.

RESULTS

The interaction between the recirculation flow in the bifurcation and the heat transfer in the surrounding tissue makes the temperature distribution near the bifurcation complicated. Most importantly, after a period of continuous heating with constant microwave output power, the maximum temperatures caused by the ablation did not always increase with the distance between the antenna and the bifurcation.

CONCLUSION

It can be concluded that inadequate ablations can be the result not only from a close proximity between the antenna and the blood vessel, but also from a complicated blood flow in large vessels whose structure causes recirculation flow.

[Infection of Helicobacter pylori strains with multiple vacA m-region subtypes and/or iceA mixed genotype among the Bai, Naxi, and Han populations in Yunnan province]

OBJECTIVE

To study the epidemiology and pathogenicity of mixed infection of Helicobacter pylori (H. pylori) strains with multiple vacA m-region subtypes and/or iceA mixed genotype among the Bai, Naxi, and Han populations in Yunnan province.

METHODS

Gastric mucous membrane were obtained by gastroscopy from 444 patients with digestive ulcer or chronic gastritis, 165 of Han nationality, 117 of Bai nationality, and 162 of Naxi nationality. H. pylori was isolated from 109 patients and cultured. RT-PCR was used to detect the Helicobacter pylori strains vacA gene subtype and iceA genes.

RESULTS

The overall rates of vacA gene s1 type and vacA gene s2 type were 98.2% (107/109) and 1.8% (2/109) respectively. The overall rates of vacA gene m2 type, vacA gene m1a type, vacA gene m1b type, and mixed types were 45.9% (50/109), 0.9% (1.109), 23.9% (26/109), and 11% (12/109) respectively; and m region was not identified in 18.3% (20/109) of the strains. The overall rates of iceA1 and iceA2 genes were 67.0% (73/109) and 41.3% (45/109) respectively. In the specimens from the patients of Bai nationality, as regards the s region, only s1 type was identified in all specimens; the rates of vacA gene m2 type, vacA gene m1a type, vacA gene m1b type, and mixed type were 45.2% (14/31), 3.2% (1/31), 12.9% (4/31), and 16.2% (5/31) respectively, and m region was not identified in 22.6% of the strains; and the rates of iceA1 and iceA2 were 87.1% (27/31) and 61.3% (19/31) respectively. In the specimens from the patients of Naxi nationally, The rates of vacA gene s1 type and s2 type were 95.6% (43/45) and 4.4% (2/45), the rates of vacA gene m2 type, vacA gene m1b type, and mixed m-type were 33.3% (15/45), 37.8% (17/45), and 6.7% (3/45) respectively, no m1a type was found, and m region was not identified in 22.2% of the strains; the rates of iceA1 and iceA2 were 48.9% (22/45) and 31.1% (14/45) respectively. In the specimens of the patients of Han nationality, as regards the s region, all specimens were s1 type; the rates of vacA gene m2 type, vacA gene m1b type, and mixed type were 63.6% (21/33), 15.2% (5/33), and 12.1% (4/33) respectively, and m region was not identified in 9.1% (3/33) of the strains; the rates of iceA1 and iceA2 were 72.7% (24/33) and 36.4% (12/33) respectively. 34 of the 109 patients (31.2%) suffered from mixed infection of vacA gene m mixed subtype and/or iceA mixed genotype, 64.7% of which (22/34) suffering iceA1 + iceA2 infection, 23.5% of which (8/34) being iceA + vacA mixed infection, and 11.8% of which (4/34) being vacA subtype mixed infection, with the former incidence of the former group significantly higher than those of the 2 latter groups (both P < 0.001). The mixed infection rate of the Bai nationality (67.7%, 21/31) was significantly higher than those of the Naxi nationality (20.0%, 9/45, P < 0.001) and Han nationality (12.1%, 4/33, P > 0.001) without a significant difference between the Naxi and Han nationalities (P > 0.05). The mixed infection rate of iceA1 + iceA2 of the Bai nationality (61.3%, 19/31) was significantly higher than those of the Naxi nationality (17.8%, 8/45, P < 0.001) and Han nationality (9.1%, 3/33, P < 0.001) without a significant difference between the Naxi and Han nationalities (P > 0.05). The mixed rate of the patients with digestive ulcer was 30.2% (16/53), not significantly different from that of the patients with chronic gastritis (32.1%, 18/56, P > 0.05). 16 of the 34 cases of mixed infection were patients of digestive ulcer; and 8 of the 34 cases were patients with chronic gastritis. 8 of the 34 cases (23.5%) of mixed infection were cases of infection of vacA gene m mixed subtypes and iceA mixed genotype; among which 7 were patients with digestive ulcer and 1 case was patient of chronic gastritis. Thus the rate of vacA gene m mixed subtypes and iceA mixed genotype was 43.8% (7/16) in the patients with digestive ulcer, significantly higher than in the patient with chronic gastritis (5.6%, 1/18, P = 0.014). 22 of the 34 cases of mixed infection (64.7%) suffered from infection of iceA mixed gene subtypes. Among these 22 cases 15 were patients with chronic gastritis and 7 were patients with digestive ulcer. Thus the rate of iceA mixed subtypes infection was 43.8% (7/16) in the patients with digestive ulcer, significantly lower than in the patient with chronic gastritis (83.3%, 15/18, P = 0.016). In the 21 mixed infection patients of Bai nationality, the rate of vacA gene mixed sybtype + iceA gene mixed subtypes infection was 100% in the patients with digestive ulcer (100%, 5/5), significantly higher than that of single vacA gene subtype + iceA gene mixed subtypes (37.5%, 6/16, P = 0.0258). The mixed infection rate of H. pylori strains was 32.1%.

CONCLUSION

The mixed infection rate of the Bai nationality is higher than those of the Han and Naxi nationalities. Detection of mixed infection by vacA genotypes is more sensitive in Han populations. Detection of multiple infections by iceA gene mixed subtypes is more sensitive in Bai and Naxi populations.

[Study on metronidazole resistance to Helicobacter pylori from three populations with different ethnics in Yunnan]

OBJECTIVE

To evaluate the prevalence of Helicobacter pylori (H.pylori) resistance to metronidazole among three populations in Yunnan.

METHODS

Susceptibilities to metronidazole among 109 H. pylori strains (33 H. pylori strains from Han, 31 H. pylori strains from Bai and 45 H. pylori strains from Naxi ethnic populations) were tested by Epsilometer test (E-test).

RESULTS

In 109 H. pylori strains, the overall metronidazole resistance rate was 67.89%. There were no significant difference in the metronidazole resistant rates of H. pylori among Han, Bai, Naxi populations Yunnan in terms of the distribution on age and upper gastroduodenal diseases. In the facet of gender, metronidazole resistant rate of H. pylori was significantly lower in Han males than in females (chi2=5.304, P=0.027), but not seen in the Bai or Naxi peoples.

CONCLUSION

Metronidazole resistance rate of H. pyloriin Yunnan was high, but no significant difference was found among Han, Bai, Naxi peoples in the province.

Computer-aided dynamic simulation of microwave-induced thermal distribution in coagulation of liver cancer

To develop a method of dynamic three-dimensional (3-D) simulation of thermal distribution in ultrasound-guided microwave coagulation therapy of liver cancer and to verify its accuracy. The specific absorption rate (SAR) values were established by measuring the temperature in equivalent phantom tests. Those values were different under different power output condition. Dynamic 3-D temperature distributions were reconstructed with a finite-element model. Testing and rectification were performed through animal experiments and clinical trials, respectively. The temperature curves in the experiments corresponded well with simulated ones in vitro--91.4% and 88.9% using single and double electrodes, respectively. The measured coagulated boundary and simulated temperature boundary had a good correspondence in 85.7% of the specimens. In both in vivo experiments and clinical trials, blood perfusion influenced the rise in temperature significantly. Temperature curves between the simulations and actual measured results showed good correspondence--67.8% (19/28) in the patients with hepatocellular carcinoma. Distance between electrodes and combined thermal distributions were both optimized with computer-aided simulation during simultaneous two-electrode coagulation. The results demonstrated that computer-aided simulation of microwave thermal distribution is an accurate and reliable method which provides a theoretical and technical basis for controlling coagulated tissue volume and placement of the electrodes during microwave coagulation therapy of liver cancer.

Structure and expression analysis of the gdcsPA and gdcsPB genes encoding two P-isoproteins of the glycine-cleavage system from Flaveria pringlei

In Flaveria pringlei, a C3 plant, P protein of the glycine-cleavage system is encoded by a small gene family consisting of at least five transcriptionally active genes. We have cloned and sequenced two of these genes, gdcsPA and gdcsPB, and provide the first detailed report on the complete structure of eukaryotic gdcsP genes. Based on the lengths of exons and intervening sequences, the P-protein genes can be subdivided into two parts. In both cases the N-terminal region consists of one very long exon followed by a long intron. In contrast, the C-terminal parts show a complex mosaic structure of relatively small exons and introns. A highly conserved leucine-zipper motif was identified, which is supposed to participate in the assembly of the glycine decarboxylase multienzyme complex. The transcript derived from the gdcsPA sequence corresponds perfectly to a leaf cDNA isolated earlier. Reverse-transcriptase PCR experiments show that both genes are preferentially active in leaves. Stems contain distinctly less P protein mRNA and the relative level in roots is very low but still clearly detectable. In all three organs, but most significantly in roots, the gdcsPA transcript level is distinctly higher than that of gdcsPB. Analysis of promoter-beta-glucuronidase fusions in transgenic tobacco suggests that far-upstream elements enhance the transcriptional activity of both genes in leaves relative to stems. The analysis of distal gdcsPA promoter deletions reveals the presence of regulatory elements acting with a distinct organ preference and indicates their approximate location.