Genome-wide development of simple sequence repeats markers and genetic diversity analysis of chayote.

BACKGROUND: Chayote is a high economic crop in the Cucurbitaceae family, playing an important role in food production, disease treatment and the production of degradable materials in industries. Due to the harsh environment, such as high temperature, drought and frost, some chayote resources are gradually disappearing. It is crucial to collect, characterize, and conserve chayote resources. However, the genetic diversity of chayote resources in China has not been studied so far. RESULTS: In this study, we collected 35 individuals of chayote from 14 provinces in China. Subsequently, we found 363,156 SSR motifs from the chayote genome and designed 57 pairs of SSR primers for validation. Out of these, 48 primer pairs successfully amplified bands, with 42 of them showing polymorphism. These 42 primer pairs detected a total of 153 alleles, averaging 3.64 alleles per locus. The polymorphic information content ranged from 0.03 to 0.78, with an average value of 0.41, indicating a high level of polymorphism. Based on the analysis using STRUCTURE, PCoA, and UPGMA methods, the 35 chayote individuals were divided into two major clusters. Through further association analysis, 7 significantly associated SSR markers were identified, including four related to peel color and three related to spine. CONCLUSIONS: These molecular markers will contribute to the analysis of genetic diversity and genetic breeding improvement of chayote in the future.

Enhancing Machine-Learning Prediction of Enzyme Catalytic Temperature Optima through Amino Acid Conservation Analysis.

Enzymes play a crucial role in various industrial production and pharmaceutical developments, serving as catalysts for numerous biochemical reactions. Determining the optimal catalytic temperature (Topt) of enzymes is crucial for optimizing reaction conditions, enhancing catalytic efficiency, and accelerating the industrial processes. However, due to the limited availability of experimentally determined Topt data and the insufficient accuracy of existing computational methods in predicting Topt, there is an urgent need for a computational approach to predict the Topt values of enzymes accurately. In this study, using phosphatase (EC 3.1.3.X) as an example, we constructed a machine learning model utilizing amino acid frequency and protein molecular weight information as features and employing the K-nearest neighbors regression algorithm to predict the Topt of enzymes. Usually, when conducting engineering for enzyme thermostability, researchers tend not to modify conserved amino acids. Therefore, we utilized this machine learning model to predict the Topt of phosphatase sequences after removing conserved amino acids. We found that the predictive model's mean coefficient of determination (R2) value increased from 0.599 to 0.755 compared to the model based on the complete sequences. Subsequently, experimental validation on 10 phosphatase enzymes with undetermined optimal catalytic temperatures shows that the predicted values of most phosphatase enzymes based on the sequence without conservative amino acids are closer to the experimental optimal catalytic temperature values. This study lays the foundation for the rapid selection of enzymes suitable for industrial conditions.

Bibliometric analysis of research trends and topic areas in traditional Chinese medicine therapy for lymphoma.

CONTEXT: Traditional Chinese Medicine (TCM) is effective as a cancer treatment modality. However, this is the first bibliometric analysis of TCM in lymphoma treatment. OBJECTIVE: This study explores the current trends and research topics of TCM in treating lymphoma from 2000 to 2023. MATERIALS AND METHODS: We searched within the Web of Science Core Collection (WoSCC) for publications on TCM in lymphoma treatment, spanning 2000 to 2023. Subsequently, we employed a comprehensive approach utilizing CiteSpace software and VOSviewer to visually analyze research trends, authors, institutions, co-cited references, and keywords. RESULTS: From January 1, 2000, to August 31, 2023, annual scientific publications on TCM for lymphoma treatment have steadily increased. Among the leading institutions in this field, the Beijing University of Chinese Medicine and the Fujian Medical University occupied the top positions. Regarding the authors, Jun Peng, Jiumao Lin, and Hongwei Chen emerged as the top three contributors. In the co-citation analysis of references, the top three co-cited references were authored by Hanahan D, Elmore S, and Livak KJ with citations numbered 13, 14, and 17, respectively. In particular, keywords reflecting current emerging trends included 'pathway', 'traditional Chinese medicine', 'oxidative stress', and 'macrophage polarization'. DISCUSSION AND CONCLUSIONS: This bibliometric analysis provides a comprehensive overview of TCM for lymphoma treatment. This analysis identified the predominant trends and research topics in the field. The findings are expected to be of significant value for researchers who focus on TCM in lymphoma treatment, helping them better understand the development of this field.

Biosynthesis of Lacto-N-biose I from starch and N-acetylglucosamine via an in vitro synthetic enzymatic biosystem.

Human milk oligosaccharides (HMOs) are very distinctive components in human milk and are beneficial for infant health. Lacto-N-biose I (LNB) is the core structural unit of HMOs, which could be used for the synthesis of other HMOs. In this study, an ATP-free in vitro synthetic enzymatic biosystem contained four thermostable enzymes (alpha-glucan phosphorylase from Thermococcus kodakarensis, UDP-glucose-hexose-1-phosphate uridylyltransferase from Thermotoga maritima, UDP-glucose 4-epimerase from T. maritima, lacto-N-biose phosphorylase from Clostridium thermobutyricum) were constructed for the biosynthesis of LNB from starch and N-acetylglucosamine (GlcNAc). Under the optimal conditions, 0.75 g/L and 2.23 g/L LNB was produced from 1.1 g/L and 4.4 g/L GlcNAc and excess starch, with the molar yield of 39% and 29% based on the GlcNAc concentration, respectively, confirming the feasibility of this in vitro synthetic enzymatic biosystem for LNB synthesis and shedding light on the biosynthesis of other HMOs using LNB as the core structural unit from low cost polysaccharides.

Biomanufacturing by In Vitro Biotransformation (ivBT) Using Purified Cascade Multi-enzymes.

In vitro biotransformation (ivBT) refers to the use of an artificial biological reaction system that employs purified enzymes for the one-pot conversion of low-cost materials into biocommodities such as ethanol, organic acids, and amino acids. Unshackled from cell growth and metabolism, ivBT exhibits distinct advantages compared with metabolic engineering, including but not limited to high engineering flexibility, ease of operation, fast reaction rate, high product yields, and good scalability. These characteristics position ivBT as a promising next-generation biomanufacturing platform. Nevertheless, challenges persist in the enhancement of bulk enzyme preparation methods, the acquisition of enzymes with superior catalytic properties, and the development of sophisticated approaches for pathway design and system optimization. In alignment with the workflow of ivBT development, this chapter presents a systematic introduction to pathway design, enzyme mining and engineering, system construction, and system optimization. The chapter also proffers perspectives on ivBT development.

Gradient boosting DD-MLP Net: An ensemble learning model using near-infrared spectroscopy to classify after-stroke dyskinesia degree during exercise.

This study aims to develop an automatic assessment of after-stroke dyskinesias degree by combining machine learning and near-infrared spectroscopy (NIRS). Thirty-five subjects were divided into five stages (healthy, patient: Brunnstrom stages 3, 4, 5, 6). NIRS was used to record the muscular hemodynamic responses from bilateral femoris (biceps brachii) muscles during passive and active upper (lower) limbs circular exercise. We used the D-S evidence theory to conduct feature information fusion and established a Gradient Boosting DD-MLP Net model, combining the dendrite network and multilayer perceptron, to realize automatic dyskinesias degree evaluation. Our model classified the upper limb dyskinesias with high accuracy: 98.91% under the passive mode and 98.69% under the active mode, and classified the lower limb dyskinesias with high accuracy: 99.45% and 99.63% under the passive and active modes, respectively. Our model combined with NIRS has great potential in monitoring the after-stroke dyskinesias degree and guiding rehabilitation training.

Effect of light intensity on celery growth and flavonoid synthesis.

Light is one of the important environmental factors affecting the growth and development of facility vegetables. In this experiment, we investigated the effects of different light intensities on the growth, nutritional quality and flavonoid accumulation of celery under hydroponic and full LED light conditions. Four light intensities of 40, 100, 200, or 300 µmol·m-2·s-1 were set up in the experiment, and three harvest periods were set up on the basis of different light intensities, which were 15, 30, and 45 d after treatment (labeled as S1, S2, and S3, respectively). The results showed that the plant height and aboveground biomass of celery increased with the increase of light intensity, and the light intensity of 200 µmol·m-2·s-1 was beneficial to increase the contents of chlorophyll, carotenoids, total phenols, vitamin C, cellulose, total flavones and apigenin in celery. During the S1-S3 period, the activities of PAL, CHS, CHI and ANS increased gradually under 200 and 300 µmol·m-2·s-1 light intensity treatments, and the activities of FNS and CHS enzymes were the highest under 200 µmol·m-2·s-1 light intensity treatment. The expression and ANS activity of Ag3GT, a key gene for anthocyanin synthesis, reached the maximum value at 300 µmol·m-2·s-1, and the expression level and FNS activity of AgFNS, a key gene for apigenin synthesis, reached a maximum value at 200 µmol·m-2·s-1. In general, the anthocyanin content was the highest at 300 µmol·m-2·s-1, and the apigenin content was the highest at 200 µmol·m-2·s-1. In conclusion, light intensity of 200 µmol·m-2·s-1 treatment was more favorable for celery growth and nutrient synthesis.

SLAMF8 expression predicts the efficacy of anti-PD1 immunotherapy in gastrointestinal cancers.

OBJECTIVES: Epstein-Barr virus (EBV) infection is associated with a better response to anti-PD1 immunotherapy. We hypothesised that genetic alterations induced by EBV infection are responsible for the activation of key immune responses and hence are predictive of anti-PD1 efficacy. METHODS: With transcriptome data of gastric cancer (GC), we explored differentially expressed genes (DEGs) specific for EBV infection and performed coexpression network analysis using the DEGs to identify the consistent coexpression genes (CCGs) between EBV-positive and EBV-negative GC tissues. We selected the tag genes of the CCGs and validated them using RNA sequencing and immunohistochemistry. We established murine models and collected tissues from clinical patients to test the value of SLAMF8 in predicting anti-PD1 treatment. The location and expression of SLAMF8 were characterised by multiplex immunofluorescence and quantitative PCR. Moreover, exogenous overexpression and RNA-sequencing analysis were used to test the potential function of SLAMF8. RESULTS: We identified 290 CCGs and validated the tag gene SLAMF8 in transcriptome data of gastrointestinal cancer (GI). We observed that the T-cell activation pathway was significantly enriched in high-expression SLAMF8 GI cancers. Higher SLAMF8 expression was positively associated with CD8 expression and a better response to anti-PD1 treatment. We further observed dynamically increased expression of SLAMF8 in murine models relatively sensitive to anti-PD1 treatment. SLAMF8 was mainly expressed on the surface of macrophages. Exogenous overexpression of SLAMF8 in macrophages resulted in enrichment of positive regulation of multiple immune-related pathways. CONCLUSION: Higher SLAMF8 expression may predict better anti-PD1 immunotherapy efficacy in GI cancer.

Differences in survival of prostate cancer Gleason 8-10 disease and the establishment of a new Gleason survival grading system.

BACKGROUND: Although the latest Gleason grading system in 2014 has distinguished between Gleason 3 + 4 and 4 + 3, Gleason 8 and Gleason 9-10 are remained systemically classified. METHODS: A total of 261,125 patients diagnosed with prostate cancer (PCa) were selected between 2005 and 2015 from the Surveillance, Epidemiology, and End Results (SEER) database. We used propensity score matching to balance clinical variables and then compared overall survival (OS) and cancer-specific survival (CSS) between Gleason score subgroups. We further establish a new Gleason survival grading system based on the hazard ratio (HR) values of each Gleason subgroup. Cox proportional hazards models and Kaplan-Meier curves were used to compare patient survival. RESULTS: Among PCa patients with Gleason score 8 disease, patients with Gleason 5 + 3 had significantly worse OS and CSS than those with Gleason 3 + 5 (OS: HR = 1.26, p = 0.042; CSS: HR = 1.42, p = 0.005) and 4 + 4 (HR = 1.50 for OS and HR = 1.69 for CSS, p < 0.001 for all). PCa patients with Gleason 5 + 3 and Gleason 4 + 5 may have the similar OS and CSS (reference Gleason score <=6, 5 + 3: OS HR = 2.44, CSS HR = 7.63; 4 + 5: OS HR = 2.40, CSS HR = 8.92; p < 0.001 for all). The new Gleason survival grading system reclassified the grades 4 and 5 of the 2014 updated Gleason grading system into three hierarchical grades, which makes the classification of grades more detailed and accurate. CONCLUSION: PCa patients with Gleason 8-10 may have three different survival subgroups, Gleason 3 + 5 and 4 + 4, Gleason 5 + 3 and 4 + 5, and Gleason 5 + 4 and 5 + 5. Our results maximize risk stratification for PCa patients, provide guidance for clinicians to assess their survival and clinical management, and make a recommendation for the next Gleason grading system update.

Involvement of CHP2 in the Development of Non-Small Cell Lung Cancer and Patients' Poor Prognosis.

The present study aimed to investigate the expression levels and clinical significance of the calcineurin B homologous protein 2 (CHP2) in non-small cell lung cancer (NSCLC), and to study its effects on biological characteristics of NSCLC cells. Tumor and adjacent samples were collected from 196 NSCLC patients. Western blot analysis was used to detect the expression levels of the CHP2 in 8 pairs of NSCLC fresh tissues and 4 NSCLC cell lines. Immunohistochemical analysis was used to detect the expression of the CHP2 in 188 additional pairs of NSCLC wax block tissues. The data indicated that the expression levels of the CHP2 in the paraffin and fresh tissues of NSCLC were significantly higher than those of the adjacent tissues. According to the histo-score, univariate and multivariate analysis indicated that a high expression level of CHP2 was an important factor affecting the 5-year survival rate of NSCLC patients. After knocking down the expression of CHP2 in NSCLC cell lines, the proliferative, migratory, and invasive activities of NSCLC-CHP2 cells were decreased which were assessed by Western blotting, Cell Counting Kit-8, and transwell and wound-healing assays. In conclusion, the data demonstrated that CHP2 was highly expressed in NSCLC and that it could promote the development of NSCLC, suggesting its potential application for the therapy of NSCLC.

Overcoming drug-resistant lung cancer by paclitaxel-loaded hyaluronic acid-coated liposomes targeted to mitochondria.

As a major cause for the inefficiency of cancer chemotherapy, multidrug resistance (MDR) has become a major barrier to cancer treatment. Mitochondrion-orientated transportation of smart liposomes has been developed as a promising strategy to deliver anticancer drugs directly to tumor sites and actively target the mitochondria, so that drugs can interfere with mitochondrial function and facilitate cell apoptosis, overcoming MDR. Herein, we report a novel dual-functional paclitaxel (PTX) liposome system possessing both CD44-targeting and mitochondrial-targeting properties to enhance drug accumulation in mitochondria and trigger apoptosis of drug-resistant cancer cells. Mitochondria-targeting PTX-loaded liposomes were prepared by thin-film hydration and then coated with hyaluronic acid (HA) by electrostatic adsorption. We evaluated the characteristics of the PTX liposomes in vitro, and found that their particle size was about 100 nm and increased to ∼140 nm after modification by HA. The entrapment efficiency was larger than 85%, and stability data indicated that the liposomes were physically and chemically stable for at least one week at 4 °C. We further evaluated the intake, mitochondrial targeting, ATP levels, caspase-3 activity measurement, and antitumor actives of the liposomes. The results indicated that HA-coated liposomes with mitochondria targeting had significant inhibitory effects against A549 and A549/Taxol cells, showing them to be a promising means of improving therapeutic efficacy and overcoming MDR in cancer treatment.

Hyaluronic acid-modified cationic niosomes for ocular gene delivery: improving transfection efficiency in retinal pigment epithelium.

OBJECTIVES: Recent years, gene therapy to treat retinal diseases has been paid much attention. The key to successful therapy is utilizing smart delivery system to achieve efficient gene delivery and transfection. In this study, hyaluronic acid (HA) modified cationic niosomes (HA-C-niosomes) have been designed in order to achieve retinal pigment epithelium (RPE) cells targeted gene delivery and efficient gene transfection. METHODS: Cationic niosomes composed of tween 80/squalene/1, 2-dioleoyl-3-trimethylammonium-propane (DOTAP) were prepared by the ethanol injection method. After that, HA-DOPE was further added into cationic niosomes to form HA-C-niosomes. Cellular uptake and transfection have been investigated in ARPE-19 cells. In vivo pEGFP transfection efficiency was evaluated in rats. KEY FINDINGS: Twenty percentage HA-C-niosomes were about 180 nm, with -30 mV, and showing spherical shape in TEM. 2 times higher transfection efficiency was found in the group of HA-C-niosomes with 20% HA modification. No toxicity was found in niosome preparations. In vivo evaluation in Sprague Dawley (SD) rats revealed that HA-C-niosomes could specifically target to the retina layer. In the group of pEGFP-loaded HA-C-niosomes, 6-6.5 times higher gene transfection has been achieved, compared with naked pEGFP. CONCLUSIONS: Hyaluronic acid-C-niosomes might provide a promising gene delivery system for successful retinal gene therapy.

Using hyaluronic acid-functionalized pH stimuli-responsive mesoporous silica nanoparticles for targeted delivery to CD44-overexpressing cancer cells.

In this study, novel hyaluronic acid-pH stimuli-responsive lipid membrane mesoporous silica nanoparticles (HA-PL-MSNs) were designed and assembled, with the chemotherapeutic agent doxorubicin (DOX) as the model drug. HA-PL-MSNs exhibited a well-defined mesostructure covered by lipid bilayer and particle size of ~150 nm. The drug loading capacity was up to ~18.2%. DOX release could be effectively retained by the lipid bilayer in pH 7.4 buffer and exhibited a pH-triggered burst release in the acidic condition. Confocal laser scanning microscopy and fluorescence-activated cell sorting showed that HA-PL-MSNs exhibited higher cellular uptake efficiency via CD44 receptor-mediated endocytosis compared with PL-MSNs in HeLa cells. In vitro cytotoxicity studies demonstrated that HA-PL-MSNs could effectively enhance the targeted delivery of DOX and restrain the growth of HeLa cells. This might provide a promising alternative for the development of a targeted anticancer drug delivery system.

[Effect of Aloe emodin on invasion and metastasis of high metastatic breast cancer MDA-MB-231 cells].

OBJECTIVE: To investigate the effect of Aloe emodin (AE) on the invasive and metastatic abilities of human high metastatic breast cancer MDA-MB-231 cells. METHODS: MTT assay was used to evaluate the viability of MDA-MB-231 cells after treated with AE for 6 h and 24 h. The adhesive potential of MDA-MB-231 cells to FN and LN was tested by cell-matrix adhesion assay. The effect of AE on invasion of MDA-MB-231 cells was measured by Transwell chamber assay. Scratch wound healing assay was applied to determine the effect on migration of MDA-MB-231 cells. The effect of AE on MDA-MB-231 lung metastasis was determined on an experimental metastatic model. RESULTS: 80 micromol/L AE significantly inhibited the invasion, adhesion to FN, LN of MDA-MB-231 cells in vitro, the inhibitory rates were (52.98 +/- 5.46)%, (34.99 +/- 2.63)%, (28.73 +/- 7.00)%, respectively. After 24 h treatment, AE significantly inhibited the migration of MDA-MB-231 cells. The number and volume of lung metastatic nodules formed by MDA-MB-231 cells after 80 micromol/L AE 24 h treatment were decreased compared with control group. CONCLUSION: AE can suppress the metastasis of MDA-MB-231 cells. Their mechanisms may be related to the inhibition of the capabilities of invasion and migration of MDA-MB-231 cells.

Effects of water regime during rice-growing season on annual direct N(2)O emission in a paddy rice-winter wheat rotation system in southeast China.

Annual paddy rice-winter wheat rotation constitutes one of the typical cropping systems in southeast China, in which various water regimes are currently practiced during the rice-growing season, including continuous flooding (F), flooding-midseason drainage-reflooding (F-D-F), and flooding-midseason drainage-reflooding and moisture but without waterlogging (F-D-F-M). We conducted a field experiment in a rice-winter wheat rotation system to gain an insight into the water regime-specific emission factors and background emissions of nitrous oxide (N(2)O) over the whole annual cycle. While flooding led to an unpronounced N(2)O emission during the rice-growing season, it incurred substantial N(2)O emission during the following non-rice season. During the non-rice season, N(2)O fluxes were, on average, 2.61 and 2.48 mg N(2)O-Nm(-)(2) day(-1) for the 250 kg N ha(-1) applied plots preceded by the F and F-D-F water regimes, which are 56% and 49% higher than those by the F-D-F-M water regime, respectively. For the annual rotation system experienced by continuous flooding during the rice-growing season, the relationship between N(2)O emission and nitrogen input predicted the emission factor and background emission of N(2)O to be 0.87% and 1.77 kg N(2)O-Nha(-1), respectively. For the plots experienced by the water regimes of F-D-F and F-D-F-M, the emission factors of N(2)O averaged 0.97% and 0.85%, with background N(2)O emissions of 2.00 kg N(2)O-Nha(-1) and 1.61 kg N(2)O-Nha(-1) for the annual rotation system, respectively. Annual direct N(2)O-N emission was estimated to be 98.1 Gg yr(-1) in Chinese rice-based cropping systems in the 1990s, consisting of 32.3 Gg during the rice-growing season and 65.8 Gg during the non-rice season, which accounts for 25-35% of the annual total emission from croplands in China.

[Quantifying direct N2O emissions from paddy fields during rice growing season in China: model and input data validation].

The models on direct N2O emissions from rice paddies under different water regimes developed by the authors were validated against field measurements in China reported in 2005-2007 and in other regions. In flooding rice paddies (F), N2O emission predicted by the model was consistent with previous reports in other regions. Under the water regime of flooding-midseason drainage-reflooding (F-D-F), the model developed in this study was comparable to that established by using worldwide database. The models also well fitted N2O emissions from rice paddies under the water regime of flooding-midseason drainage-reflooding-moisture but without waterlogging (F-D-F-M) in China. Consistency of rice production data derived from the database of this study with those reported in previous studies suggests that the model input data of rice production had high reliability. The input data showed that water management and nitrogen input regimes have greatly changed in rice paddies since the 1950s. During the 1950s-1970s, about 20%-25% of the rice paddy was continuous water logging, and 75%-80% under the water regime of F-D-F. Since the 1980s, about 12%-16%, 77% and 7%-12% of paddy fields were under the water regimes of F, F-D-F and F-D-F-M, respectively. Total N input during the rice growing season averaged 87.49 kg x hm(-2) in the 1950s and 224.64 kg x hm(-2) in the 1990s. Chemical N input during the rice growing season has increased from 37.4 kg x hm(-2) in the 1950s to 198.8 kg x hm(-2) in the 1990s, accounting for 43% and 88% of the seasonal total N inputs, respectively. Manure N input was applied at stable rate, ranging from 45.2 kg x hm(-2) to 48.2 kg x hm(-2) during the 1950s-1970s, but thereafter it decreased over time. The contribution of manure N to total N inputs has decreased from 52% in the 1950s to 9% in the 1990s. Crop residue N retained during the rice growing season has increased from 4.9 kg x hm(-2) in the 1950s to 6.3 kg x hm(-2) in the 1980s. A high spatial variation of nitrogen inputs during the rice growing season was found in the 1950s-1970s, while it was not pronounced in the 1980s-1990s. Overall, the results of this study suggest that the models could be used to quantify direct N2O emissions from rice paddies under various water regimes in China.

[Quantifying direct N2O emissions from paddy fields during rice growing season in China: model application].

Based on statistical analysis of field N2O measurements in rice paddies in China, the models on direct N2O emissions under different water regimes were established. After successes in model validation and input data verification, the models were used to quantify changes in direct N2O emissions from paddy fields during the rice growing season in mainland China between the 1950s and the 1990s. Due to increases in rice planting area and nitrogen input and changes in water regime, the models predicted that seasonal N2O-N emissions from rice paddies have increased from 9.55 Gg each year in the 1950s to 32.26 Gg N2O-N in the 1990s, which was accompanied by the increase in rice yield over the period 1950s-1990s. During the period 1950s-1990s, seasonal N2O-N emissions from rice paddies have increased, on average, at a rate of 6.74 Gg per decade. Seasonal N2O fluxes in rice paddies were estimated to be 0.32 kg x hm(-2) in the 1950s and 1.00 kg x hm(-2) in the 1990s, which accounted for 0.37% and 0.46% of the seasonal total N inputs, respectively. The uncertainties in N2O estimate were estimated to be 59.8% in the 1950s and 37.5% in the 1990s. Seasonal N2O emissions from rice paddies in the region of middle and lower Yangtze River contributed 51% -56% to its national total. In the 1990s, N2O emissions during the rice growing season accounted for 8%-11% of the reported annual total of N2O emissions from croplands in China, suggesting that paddy rice development could have contributed to mitigating agricultural N2O emissions in the past decades. However, seasonal N2O emissions would be increased given that saving-water irrigation and nitrogen inputs are increasingly adopted in rice paddies in China.

[Quantifying direct N2O emissions from paddy fields during rice growing season in China: model establishment].

Various water management regimes, such as continuous flooding (F), flooding-midseason drainage-reflooding (F-D-F), and flooding-midseason drainage-reflooding-moist intermittent irrigation but without water logging (F-D-F-M), are currently practiced in paddy rice production in China. These water regimes have incurred a sensitive change in direct N2O emission from rice paddy fields. In order to establish statistical models quantifying the country-specific emission factor and background emission of N2O in paddy fields during the rice growing season, we compiled and statistically analyzed field data on 71 N2O measurements from 17 field studies that were published in peer-reviewed Chinese and English journals. For each field study, we documented the seasonal N2O emission, the type and amount of organic amendment and fertilizer nitrogen application, the water management regime, the drainage duration, the field location and cropping season. Seasonal total N2O was, on average, equivalent to 0.02% of the nitrogen applied in the continuous flooding rice paddies. Under the water regime of F-D-F or the F-D-F-M, seasonal N2O emissions increased with N fertilizer applied in rice paddies. Applying an Ordinary Least Square (OLS) linear regression model resulted in an emission factor of 0.42% for N2O, and in unpronounced background N2 O emission under the water regime of F-D-F. Under the F-D-F-M water regime, N2O emission factor and N2O-N background emission were estimated to be 0.73% and 0.79 kg x hm(-2) during the paddy rice growing season, respectively. After considering three different water regimes in rice paddies in China, the emission factor of N for N2O and N2O-N background emission averaged 0.54% and 0.43 kg x hm(-2). The results of this study suggest that paddy rice relative to upland crop production could have contributed to mitigating N2O emissions from agriculture in China. The emission factor of N for N2O and its background emissions can be directly adopted to develop national inventory of N2O emissions from paddy fields during the rice growing season in China.

[Study on the effect of resveratrol on metastasis-associated ability of ovarian carcinoma HO-8910PM cells in vitro].

OBJECTIVE: To investigate the inhibitory effect of resveratrol on the metastasis-associated ability of human highly metastatic ovarian carcinoma HO-8910PM cells in vitro. METHODS: MTf assay was used to examine the cytotoxicity of resveratrol in HO-8910PM cells; Transwell Chamber assay was performed to determine the effect on invasion and migratory capacity of the cells by resveratrol; Effect on adhesion potential of HO-8910PM cells was tested by cell-Matrigel adhesion assay. RESULTS: Resveratrol showed no cytotoxicity on HO-8910PM cells after 6 h treatment. Resveratrol significantly inhibited migration and adhesion capacity of HO-8910PM cells in vitro. Their inhibitory rates after treated with the chemical of 100 micromol/L for 6 h were (30. 1 +/- 10. 8) % ,(34. 27 +/- 1. 28)% , respectively. However, Resveratrol had no effect on invasion capacity of HO-8910PM cells. CONCLUSION: Resveratrol can inhibit the migration and adhesion of HO-8910PM cells in vitro. Resveratrol might be a potential drug to inhibit tumor metastasis.