Continuous cropping has become a common form of agricultural production at present, but with the increase of continuous cropping years, continuous cropping obstacles such as soil-borne diseases and plant growth potent...Continuous cropping has become a common form of agricultural production at present, but with the increase of continuous cropping years, continuous cropping obstacles such as soil-borne diseases and plant growth potential decline are becoming more and more common. At present, the causes of continuous cropping obstacles and continuous cropping restoration have become a hot issue in agricultural research. This paper summarized the effects of continuous cropping obstacles on soil microbial community structure and main technical methods to repair continuous cropping obstacles, such as agricultural measure management, microbial balance adjustment and soil improvement, aiming to provide theoretical reference for protecting the sustainable utilization of soil ecosystem and ensuring the stability of crop production.展开更多
BACKGROUND Second-look endoscopy(SLE)to prevent recurrent bleeding in patients with peptic ulcer disease(PUD)and those undergoing endoscopic submucosal dissection(ESD)is routinely being performed.Conflicting evidence ...BACKGROUND Second-look endoscopy(SLE)to prevent recurrent bleeding in patients with peptic ulcer disease(PUD)and those undergoing endoscopic submucosal dissection(ESD)is routinely being performed.Conflicting evidence exists regarding efficacy,risk,benefit,and cost-effectiveness.AIM To identify the role and effectiveness of SLE in ESD and PUD,associated rebleeding and PUD-related outcomes like mortality,hospital length of stay,need for endoscopic or surgical intervention and blood transfusions.METHODS A systematic review of literature databases PubMed,Cochrane,and Embase was conducted from inception to January 5,2023.Randomized controlled trials that compared patients with SLE to those who did not have SLE or evaluated the role of prophylactic hemostasis during SLE compared to other conservative interventions were included.The study was conducted per PRISMA guidelines,and the protocol was registered in PROSPERO(ID CRD42023427555:).RevMan was used to perform meta-analysis,and Mantel-Haenszel Odds ratio(OR)were generated using random effect models.RESULTS A total of twelve studies with 2687 patients were included in our systematic review and meta-analysis,of which 1074 patients underwent SLE after ESD and 1613 patients underwent SLE after PUD-related bleeding.In ESD,the rates of rebleeding were 7%in the SLE group compared to 4.4%in the non-SLE group with OR 1.65,95%confidence intervals(CI)of 0.96 to 2.85;P=0.07,whereas it was 11%in the SLE group compared to 13%in the non-SLE group with OR 0.895%CI:0.50 to 1.29;P=0.36.The mean difference in the blood transfusion rates in the SLE and no SLE group in PUD was OR 0.01,95%CI:-0.22 to 0.25;P=0.91.In SLE vs non-SLE groups with PUD,the OR for Endoscopic intervention was 0.29,95%CI:0.08 to 1.00;P=0.05 while it was OR 2.03,95%CI:0.95 to 4.33;P=0.07,for surgical intervention.The mean difference in the hospital length of stay was-3.57 d between the SLE and no SLE groups in PUD with 95%CI:-7.84 to 0.69;P=0.10,denoting an average of approximately 3 fewer days of hospital stay among patients with PUD who underwent SLE.For mortality between SLE and non-SLE groups in PUD,the OR was 0.88,95%CI:0.45 to 1.72;P=0.70.CONCLUSION SLE does not confer any benefit in preventing ESD and PUD-associated rebleeding.SLE also does not provide any significant improvement in mortality,need for interventions,or blood transfusions in PUD patients.SLE decreases the hospital length of stay on average by 3.5 d in PUD patients.展开更多
The effects of survivin antisense RNA on proliferation of leukemia cell line HL-60 and taxol-induced chemotherapy was explored. A cDNA fragment of survivin obtained by RT-PCR was inserted into a plamid vector named pc...The effects of survivin antisense RNA on proliferation of leukemia cell line HL-60 and taxol-induced chemotherapy was explored. A cDNA fragment of survivin obtained by RT-PCR was inserted into a plamid vector named pcDNA3 in the reverse direction. The vector encoding antisense RNA of survivin was confirmed by restriction enzyme digestion and DNA sequencing. The recombinant plasmid was delivered into HL-60 cells by electroporation. Growth curves were plotted based on cell counting. Trypan blue dye exclusion assay and MTT assay were carried out after the cells were incubated with taxol. DNA gel electrophoresis and nuclear staining were performed for cell apoptosis assay. The correct construction of the recombinant plasmid has been identified by restriction enzyme digestion and DNA sequencing. A stable down-regulation has been achieved in HL-60 SVVas cells after G418 selection. Compared to HL-60 cells, the proliferation of HL-60 SVVas cells was significantly inhibited (P〈0.05). Cytotoxicity assays indicated that IC50 of HL-60 SVVas for taxol was relatively lower than controls (P〈0.01). Apoptosis assays revealed that taxol-induced apoptosis was detected in HL-60 SVVas cells incubated with 50 ng/ml taxol for 12 h, while in HL-60 cells incubated with 100 ng/ml taxol for 72 h. It was suggested that Survivin antisense RNA could inhibit the proliferation of HL-60 cells and enhance taxol-induced apoptosis in HL-60 cells, which may lay an experimental foundation for further research on gene therapy in leukemia.展开更多
Azalea is a general designation of Rhododendron in the Ericaceae family.Rhododendron not only has high ornamental value but also has application value in ecological protection,medicine,and scientific research.In this ...Azalea is a general designation of Rhododendron in the Ericaceae family.Rhododendron not only has high ornamental value but also has application value in ecological protection,medicine,and scientific research.In this study,we used Illumina and PacBio sequencing to assemble and annotate the entire chloroplast genomes(cp genomes)of four Rhododendron species.The chloroplast genomes of R.concinnum,R.henanense subsp.lingbaoense,R.micranthum,and R.simsii were assembled into 207,236,208,015,207,233,and 206,912 bp,respectively.All chloroplast genomes contain eight rRNA genes,with either 88 or 89 protein-coding genes.The four cp genomes were compared and analyzed by bioinformatics,and the phylogenetic analysis based on chloroplast genomes of 26 species of Ericaceae,Actinidiaceae,and Primulaceae under Ericales was conducted.A comparison of the linear structure of cp genomes of four Rhododendron showed that there were substantial sequence similarities in coding regions,but high differences in non-coding regions.A phylogenetic analysis,based on chloroplast whole genome sequences,showed that all Rhododendron species are in the clade Ericaceae.This study provides valuable genetic information for the study of population genetics and evolutionary relationships in Rhododendron and other azalea species.展开更多
Background:Acer griseum Pax is an endangered species endemic to China with both ornamental and economic value.However,the lack of information on its genome size and characteristics hinders further work at the genome l...Background:Acer griseum Pax is an endangered species endemic to China with both ornamental and economic value.However,the lack of information on its genome size and characteristics hinders further work at the genome level.Methods:This paper applied bioinformatics methods to predict the characteristics and patterns of the A.griseum genome,providing an important basis for formulating its whole-genome sequencing scheme.This study also characterized the simple sequence repeats(SSRs)of A.griseum,laying the foundation for the development and application of genome-wide SSR markers.In this study,PE150 sequencing was performed by the BGI MGISEQ platform,and the sequence files were analyzed by the K-mer method to estimate the characteristic information by GCE software.Results:The genome size was finally determined to be 739.63 Mb,its heterozygosity ratio was 1.33%,and the repetition ratio was 65.68%.A total of 825,960 SSR loci were identified in the assembled genome sequence,and primers were successfully designed for 526,020 loci.To verify the effectiveness of these primers,100 pairs of primers were randomly selected and synthesized,and 81 pairs successfully amplified the target fragments.Fourteen pairs of primers with good polymorphism were selected for principal component analysis of 31 A.griseum individuals from two populations,showing favorable heterozygosity and PIC values.According to the findings,these SSRs might identify genetic variations based on geographic areas.Conclusion:It is suggested that Illumina+PacBio assembly strategy should be used for whole-genome sequencing due to the high heterozygosity rate and high repetition rate of the genome.In addition,the SSR primers designed in batches in this study laid a foundation for the in-depth study of population structure and population maintenance mechanism of A.griseum,which is helpful for the effective conservation and sustainable utilization of this germplasm resource.展开更多
Large numbers of bacteria live on the surface of various brown algae and can produce alginate lyases to consume alginate,an important component of the cell wall of brown algae.Sargassum is a genus of the largest canop...Large numbers of bacteria live on the surface of various brown algae and can produce alginate lyases to consume alginate,an important component of the cell wall of brown algae.Sargassum is a genus of the largest canopyforming brown algae of more than 150 species,which are widely distributed in tropical and subtropical environments.However,our knowledge about the epiphytic bacteria and the alginate lyase-excreting bacteria from Sargassum is still primitive.Here,we investigated the diversity of the culturable epiphytic bacteria and alginate-degrading bacteria from Sargassum samples collected from the coastal seawaters of Shandong Province,China.In total,37 strains belonging to 21 genera in 3 phyla were isolated,including 15 previously unreported genera,of which Vibrio(6/37)and Pseudoalteromonas(5/37)are the dominant genera.Eight strains,mainly Vibrio and Pseudoalteromonas species,were further identified as alginate lyase-excreting strains that can utilize alginate for growth.The extracellular alginolytic activity of the 8 strains was determined,and strains Vibrio sp.C42and Pseudoalteromonas sp.M9 showed the highest activity.These results provide a better understanding of brown algae epiphytes and alginate-degrading bacteria,and are fundamental for further studies on the interactions between brown algae and their epiphytes.展开更多
The automatic and accurate identification of apoptosis facilitates large-scale cell analysis.Most identification approaches using nucleus fluorescence imaging are based on specific morphological parameters.However,the...The automatic and accurate identification of apoptosis facilitates large-scale cell analysis.Most identification approaches using nucleus fluorescence imaging are based on specific morphological parameters.However,these parameters cannot completely describe nuclear morphology,thus limiting the identification accuracy of models.This paper proposes a new feature extraction method to improve the performance of the model for apoptosis identification.The proposed method uses a histogram of oriented gradient(HOG)of high-frequency wavelet coefficients to extract internal and edge texture information.The HOG vectors are classified using support vector machine.The experimental results demonstrate that the proposed feature extraction method well performs apoptosis identification,attaining 95:7% accuracy with low cost in terms of time.We confirmed that our method has potential applications to cell biology research.展开更多
Bioprobe based on fluorescence is widely used in biological and medical research due to its high sensitivity and selectivity.Yet,its quantification in vivo is complicated and often compromised by the interaction betwe...Bioprobe based on fluorescence is widely used in biological and medical research due to its high sensitivity and selectivity.Yet,its quantification in vivo is complicated and often compromised by the interaction between the fluorophore with the environmental factors,as well as the optical scattering and absorption by the tissue.A high florescence quantum yield and minimal interference by the environment are key requirements for designing an effective bioprobe,and the prerequisitions severely limit the available options.We propose that a comprehensive evaluation of potential bioprobe can be achieved by simultaneously measuring both radiative and nonradiative transitions,the two fundamental and complementary pathways for the energy de-excitation.This approach will not only improve the accuracy of the quantification by catching the information from a broader spectrum of the energy,but also provide additional information of the probe environment that often impacts the balance between the two forms of the energy transition.This work first analyzes the underlying mechanism of the hypothesis.The practical feasibility is then tested by means of simultaneous measurements of photoacoustic signal for the non-radiative and fluorescence for the radiative energy processes,respectively.It is demonstrated that the systematic evaluation of the probe energy de-excitation results in an improved quantitative tracing of a bioprobe in complex environment.展开更多
[Objectives]To protect the local rare citrus germplasm resources and further develop and cultivate new citrus varieties.[Methods]The germplasm resources of Shatangju(Citrus flamea Hort.Ex Tseng Shiyueju)in Sihui City ...[Objectives]To protect the local rare citrus germplasm resources and further develop and cultivate new citrus varieties.[Methods]The germplasm resources of Shatangju(Citrus flamea Hort.Ex Tseng Shiyueju)in Sihui City of Guangdong Province and other 8 citrus varieties from the same origin were evaluated.The appearance characteristics of tree shape,the length and thickness of shoot at each shoot stage,the appearance characteristics of leaves and the fruit quality of each variety were investigated.[Results]Through the comparison of various citrus varieties grafted with sour mandarin,the results showed that the overall advantages of the length and thickness of the shoots of Shatang tangerine in summer and autumn were more prominent,which was conducive to fruit setting.The sprouting time of the three shoots of each variety was different,and there were sporadic sprouting phenomena in different seasons,so the growth was different,and the length and thickness of the shoots were different in different seasons.There were significant differences in shoot length and diameter among different varieties in the same season.The coefficient of variation of Shatangju's leaves was low,and the traits were stable;leaf shape,leaf base shape,leaf margin and other indicators among the three shoots of the same variety and the differences among the same shoots of different varieties were compared.All varieties had strong flavor,separately sweet and sour,sweet and sweet taste.Shatangju has many segments,orange pericarp,rough texture,easy peeling,and high oblate fruit shape.The orange pericarp was favored by the participants,while the rough and thick peel was not favored by the participants.[Conclusions]Based on the improvement of local varieties,it is recommended to improve the smoothness of pericarp,reducing the thickness of pericarp and improving the flavor of fruit will be conducive to increasing sales.In the cultivation process of various quality resources,especially in the period of fruit growth and development,the plan of nutrition and fertilization should be formulated according to the rules of fruit growth and development,the rules of yield formation and the rules of quality composition,so as to establish the integrated nutrient management system of various varieties.展开更多
As an emerging hybrid imaging modality,microwave-induced thermoacoustic imaging(MTAI),using microwaves as the excitation source and ultrasonic signals as the information carrier for combining the characteristics of hi...As an emerging hybrid imaging modality,microwave-induced thermoacoustic imaging(MTAI),using microwaves as the excitation source and ultrasonic signals as the information carrier for combining the characteristics of high contrast of electromagnetic imaging and high resolution of ultrasound imaging,has shown broad prospects in biomedical and clinical applications.The imaging contrast depends on the microwave-absorption coe±cient of the endogenous imaged tissue and the injected MTAI contrast agents.With systemically introduced functional nanoparticles,MTAI contrast and sensitivity can be further improved,and enables visualization of biological processes in vivo.In recent years,functional nanoparticles for MTAI have been developed to improve the performance and application range of MTAI in biomedical applications.This paper reviews the recent progress of functional nanoparticles for MTAI and their biomedical applications.The challenges and future directions of microwave thermoacoustic imaging with functional nanoparticles in theeld of translational medicine are discussed.展开更多
BACKGROUND Non-alcoholic fatty liver disease(NAFLD)and metabolic-associated fatty liver disease(MAFLD)are on the rise like any other liver disease,and tend to affect 25%of the United States population.The impact of NA...BACKGROUND Non-alcoholic fatty liver disease(NAFLD)and metabolic-associated fatty liver disease(MAFLD)are on the rise like any other liver disease,and tend to affect 25%of the United States population.The impact of NAFLD and MAFLD on patients with coronavirus disease 2019(COVID-19)remains unclear.AIM To identify the association of NAFLD and MAFLD with mortality,hospitalization,hospital length of stay,and supplemental oxygen utilization in COVID-19 patients.METHODS A systematic review of literature on Cochrane,Embase,PubMed,ScienceDirect,and Web of Science databases was conducted from January 2019 to July 2022.Studies that evaluated NAFLD/MAFLD using laboratory methods,noninvasive imaging,or liver biopsy were included.The study protocol was registered in PROSPERO(ID CRD42022313259)and PRISMA guidelines were followed.The National Institutes of Health quality assessment tool was used to assess the quality of the studies.Pooled analysis was conducted using software Rev Man version 5.3.The stability of the results was assessed using sensitivity analysis.RESULTS Thirty-two studies with 43388 patients were included in the meta-analysis of whom 8538(20%)patients were observed to have NAFLD.There were 42254 patients from 28 studies included in the mortality analysis.A total of 2008 patients died from COVID-19;837(10.52%)in the NAFLD group and 1171(3.41%)in the non-NAFLD group.The odds ratio(OR)was 1.38 for mortality with a 95%confidence interval(95%CI)=0.97-1.95 and P=0.07.A total of 5043 patients from eight studies were included in the hospital length of stay analysis.There were 1318 patients in the NAFLD group and 3725 patients in the non-NAFLD group.A qualitative synthesis showed that the mean difference in hospital length of stay was about 2 d between the NAFLD and non-NAFLD groups with a 95%CI=0.71-3.27 and P=0.002.For hospitalization rates,the OR was 3.25 with a 95%CI of 1.73-6.10 and P=0.0002.For supplemental oxygen utilization,the OR was 2.04 with a 95%CI of 1.17-3.53 and P=0.01.CONCLUSION Our meta-analysis suggests that there are increased odds of hospitalization,longer hospital length of stay,and increased use of supplemental oxygen in NAFLD/MAFLD patients.展开更多
In previous experiment, we isolated a compound dibutyl phthalate (DBP) from Vaccaria segetalis which had galactopoietic function on mammary gland epithelial cells of dairy cow (DCMECs). In this experiment, we asce...In previous experiment, we isolated a compound dibutyl phthalate (DBP) from Vaccaria segetalis which had galactopoietic function on mammary gland epithelial cells of dairy cow (DCMECs). In this experiment, we ascertained the metabolic regulation function of DBP on DCMECs. Many genes related to lactation including Stat5, AMPK, b-casein, Glut1, SREBP-1, PEPCK, and ACC were detected by real-time PCR. Furthermore, Stat5 and AMPK were detected by Western blot and immunofluorescence co-localization, respectively. The results showed that DBP stimulates the expression of Stat5 and p-Stat5, thus activates Stat5 cell signal transduction pathway and stimulates b-casein synthesis. DBP also raises the activities of Glut1 and AMPK to stimulate glucose uptake and glycometabolism and activates the expression of AMPK downstream target genes PEPCK and ACC and expression of SREBP-1 to stimulate milk fat synthesis. In addition, the activities of HK, G-6-PDH, ICDH, ATPase, and energy charges were stimulated by DBP to increase the energy metabolism level of DCMECs. The results showed DBP stimulates energy metabolism related to galactopoietic function in DCMECs.展开更多
A field experiment was conducted at Kezuohouqi County, Inner Mongolia Autonomous Region of China, which was located on the southeastern edge of the Horqin Sandy Land, to study the spatial variability of soil nutrients...A field experiment was conducted at Kezuohouqi County, Inner Mongolia Autonomous Region of China, which was located on the southeastern edge of the Horqin Sandy Land, to study the spatial variability of soil nutrients for a smallscale, nutrient-poor, sandy site in a semi-arid region of northern China; to investigate whether or not there were 'islands of fertility' at the experimental site; and to determine the key nutrient elements that sustained ecosystem stability. Results obtained from geostatistical analysis indicated that the spatial distribution pattern of soil total nitrogen (STN) was far different from those of soil organic matter (SOM), total phosphorus (STP), and total potassium (STK). Compared to SOM, STP, and STK, STN had a lower structural heterogeneity ratio and a longer range, while other elements were all similar. In addition, STN had an isotropic spatial structure, whereas the others had an anisotropic spatial structure. The spatial structure patterns of herbage species, cover,and height also differed, indicating that spatial variability was subjected to different ecological factors. Differences in the spatial variability patterns among soil nutrients and vegetation properties showed that soil nutrients for a small-scale were not the primary limiting factors that influenced herbage spatial distribution patterns. Incorporating spatial distribution patterns of tree species, namely, Pinus sylvestris var. mongolica Litv. and shrub Lespedeza bicolor Turcz. in a research plot and using fractal dimension,SOM, STP, and STK were shown to contribute to the 'islands of fertility' phenomenon, however STN was not, possibly meaning that nitrogen was a key limiting element. Therefore, during restoration of similar ecosystems more attention should be given to soil nitrogen.展开更多
The effect and the mechanism of action of lanthanum, cerium and neodymium on aged seeds of spinach were studied. By LaCl_3, CeCl_3, and NdCl_3 treatment, the germination rate, germination index and vigor index of aged...The effect and the mechanism of action of lanthanum, cerium and neodymium on aged seeds of spinach were studied. By LaCl_3, CeCl_3, and NdCl_3 treatment, the germination rate, germination index and vigor index of aged spinach seeds are increased and the activities of superoxide dismutase, catalase and peroxidase are enhanced. Moreover the ·O_2^- and malondialdehyde content are decreased and the cell membrane permeability of aged spinach seeds is reduced. Among these three rare earth elements, Ce treatment enhances vigor of aged seeds most significantly, that of Nd treatment secondly and La treatment is not as effective as the other two treatments. The reason may be from 4f electron characteristic and alternation valence of REEs.展开更多
Objective To study the regulating effects of a novel CpG oligodeoxynuleotide and the synergistic effect of chitosan-nanoparticles (CNP) with CpG on immune responses of mice, which were used to develop a novel immuno...Objective To study the regulating effects of a novel CpG oligodeoxynuleotide and the synergistic effect of chitosan-nanoparticles (CNP) with CpG on immune responses of mice, which were used to develop a novel immunoadjuvant to boost immune response to conventional vaccines. Methods A novel CpG ODN containing 11 CpG motifs was synthesized and its bioactivities to stimulate the proliferation of lymphocytes of pig in vitro were detected. Then it was entrapped with CNP prepared in our laboratory by the method of ionic cross linkage, and immunized Kunming mice were co-inoculated with paratyphoid vaccine. The peripheral blood was collected weekly from the tail vein of inoculated mice to detect the contents of IgG, IgA, IgM, and specific antibody against salmonella as well as the levels of interleukin-2 (IL2), IL-4, and IL-6 by SABC-ELISA assay. The numbers of leucocytes, monocytes, granuloytes, and lymphocytes were calculated separately using the routine method. The experimental mice were orally challenged with virulent salmonella 35 days after inoculation. Results This CpG ODN could remarkably provoke the proliferation of lymphocytes of pig in vitro in contrast with the control (P〈0.05). Compared with those of the control, immunoglobulins, including IgG, IgA, IgM, and specific antibodies to paratyphoid vaccine, increased significantly in sera from the CpG or CpG-CNP-vaccinated mice (P〈0.05). IL-2, IL-4, and IL-6 increased remarkably in sera from immunized mice (P〈0.05). The leucocytes, monocytes, granuloytes, and lymphocytes of the mice immunized with CpG or CpG-CNP were also increased in number (P〈0.05). After the challenge, these immunity values were elevated in the mice vaccinated with CpG or CpG-CNP. The immunized mice all survived, while the control mice fell ill with evident lesions with diffuse hemorrhage in stomach, small intestine, and peritoneum. Conclusions CpG ODN entrapped with CNP is a promising effective immunoadjuvant for vaccination, which promotes humoral and cellular immune responses, enhances immunity and resistance against salmonella by co-administration with paratyphoid vaccine. Key words:展开更多
The dynamics of soil inorganic nitrogen (NH4+ -N and NO-3 -N) and microbial biomass carbon (Cmic) and nitrogen (Nmic) under 30-year-old fenced Pinus sylvestris L. var. mongolica Litvin (SF), unfenced P. sylvestris L. ...The dynamics of soil inorganic nitrogen (NH4+ -N and NO-3 -N) and microbial biomass carbon (Cmic) and nitrogen (Nmic) under 30-year-old fenced Pinus sylvestris L. var. mongolica Litvin (SF), unfenced P. sylvestris L. var. mongolica Litvin (SUF), and unfenced Pinus densiflora Siebold et Zucc. (DUF) plantations in the Zhanggutai sandy soil of China were studied during Apr. to Oct. 2004 by the in situ closed-top core incubation method. All mentioned C and N indices in each stand type fluctuated over time. The ranges of inorganic N, Cmic, and Nmic contents in the three stand types were 0.7–2.6, 40.0–128.9, and 5.4–15.2 μg g-1, respectively. The average contents of soil NH4+ -N and Cmic under the three 30-year-old pine plantations were not different. However, soil NO3 -N and total inorganic N contents decreased in the order of SUF ≥ SF ≥ DUF, the Nmic content was in the order of SF = SUF > DUF, and the Cmic:Nmic ratio was in the order of SUF = DUF > SF. Seasonal variations were observed in soil inorganic N, microbial biomass, and plant growth. These seasonal variations had certain correlations with microbe and plant N use in the soil, and their competition for NH+4 -N was mostly regulated by soil N availability. The influence of tree species on inorganic N and Nmic were mainly because of differences in litter quality. Lack of grazing decreased the Cmic:Nmic ratio owing to decreased carbon output and increased the ability of soil to supply N. The soil N supply under the P. sylvestris var. mongolica plantation was lower than under the P. densiflora plantation.展开更多
Rare earth elements(REE)are applied as micro-fertilizer in large scale in China and there is growing concern about the environmental effects of REE accumulation in soils. Accumulation of REE was simulated in lab by ad...Rare earth elements(REE)are applied as micro-fertilizer in large scale in China and there is growing concern about the environmental effects of REE accumulation in soils. Accumulation of REE was simulated in lab by adding REE to three soils and the survival of Pseudomonas fluorescence X16 strain marked with luxAB gene in soils was detected. Curvilinear regression method was applied to analyze the survival pattern. The stimulation values, EC_(50) and NOEC values for X16 strain were calculated to compare the toxic intensity of REE in different soils. The stimulation(peak)values in red soil, yellow fluovo-aquic soil and yellow cinnamon soil, are 11.55~18.08,(0~2.13), 2.37~4.62 mg·kg^(-1) , respectively. EC_(50) values are 13.47~39.12, 6.59~56.18, 372~1034 (mg·kg^(-1)), respectively.NOEC values are 5.62 ~21.41, 0.00~4.53, 133.3~327.1 mg·kg^(-1), respectively. Tangents values of regression equation of the survival of X16 strain in red soil are the maximum ones indicating that REE accumulation in red soil has stronger inhibitory effects than in other two soils. The soil order, reflecting toxic intensity of REE is as follows: red soil>yellow fluovic-aquic soil>yellow cinnamon soil.展开更多
Vegetative cells of Porphyra yezoensis are isolated with sea snail enzyme and cultured on the solidified agar medium. The results of experiments show that the isolated cells can survive,divide and regenerate well on t...Vegetative cells of Porphyra yezoensis are isolated with sea snail enzyme and cultured on the solidified agar medium. The results of experiments show that the isolated cells can survive,divide and regenerate well on the medium solidified with agar. The first division on the solid medium starts after 7 days' culture, 4 days later than the liquid culture. The survival rate of isolated cells is 71.3% on the solid medium, lower than the 86.2% of that in seawater.Thalli, thalloids,conchocelis, spermatangia and multicellular masses are developed on the solid/medium in the first month, slowly but normally. Spermatangia sacs disappear within 4 weeks. Without adding nutrient liquid onto the surface of solid medium or injecting seawater under the agar layer in order to keep moisture, the thalli and cell groups release monospores to form new thalli instead of enlarging their areas after 5 weeks' culturing. Some monospores regenerate new thalli. Other monospores lose their pigments and minimize their volume and divide quickly to form light pink calli. After 16 weeks, numerous calli can be seen on the solid medium and after 24 weeks' culturing, almost only calli and conchocelis can be seen. If the calli are immersed in seawater, the monospores are released and may develop into young thallus.展开更多
Effect of UV - B radiation on the feeding behaviour of marine zooplankton is important to assessing the health harm of marine ecosystem due to the gradually enhanced UV - B radiation in air. However, there are a few s...Effect of UV - B radiation on the feeding behaviour of marine zooplankton is important to assessing the health harm of marine ecosystem due to the gradually enhanced UV - B radiation in air. However, there are a few studies on this topic. The feeding behavior of the rotifer, Brachionus plicatilis, under the treatment of UV - B radiation on five species of microalgae, i. e. , Chlorella sp. , Tetraselmis chuii, Isochrysis galbana Park 8701, Chaetoceros muelleri Lermumerman, and Nitzschia clostertum, was studied. The results showed that the filtering and feeding rates of the rotifer decreased significantly with the dose increase of UV - B radiation when fed with five species of microalgae respectively ( P 〈 0.05 ) which indicates UV - B radiation inhibits the feeding activities of the rotifer on microalage. The mixed culture experiments shows the rotifer preferred to feed Chlorella sp. , then C. muelleri, L galbana, N. clostertum and T. chuii in turn if without UV - B radiation. Under the highest dose of UV - B radiation treatment (2.70 kJ/m^2), the rotifer preferred to feed C. muelleri, then Chlorella sp. , N. clostertum, L galbana and T. chuii in turn. Chlorella sp. , L galbana and C. muelleri became the more favorite foods of the rotifer while T. chuii and N. clostertum became less favorite foods. The change of feeding rate and feeding selectivity of zooplankton driven by the enhanced UV - B radiation will lead to the change in the structure of phytoplankton community.展开更多
基金Supported by National Natural Science Foundation of China(42067009)Scientific Research Project of Yunnan Provincial Department of Education(2024Y742,2023Y0863)+2 种基金Project of Kunming Municipal Commission of Development and Reform(Kunming Spring City Industrial Technology Leading Talents)Science and Technology Major Project of Yunnan Province Science and Technology Department(202202AE090015-02)Yunnan Students’innovation and entrepreneurship training program(S202311393044,S202311393061)。
文摘Continuous cropping has become a common form of agricultural production at present, but with the increase of continuous cropping years, continuous cropping obstacles such as soil-borne diseases and plant growth potential decline are becoming more and more common. At present, the causes of continuous cropping obstacles and continuous cropping restoration have become a hot issue in agricultural research. This paper summarized the effects of continuous cropping obstacles on soil microbial community structure and main technical methods to repair continuous cropping obstacles, such as agricultural measure management, microbial balance adjustment and soil improvement, aiming to provide theoretical reference for protecting the sustainable utilization of soil ecosystem and ensuring the stability of crop production.
文摘BACKGROUND Second-look endoscopy(SLE)to prevent recurrent bleeding in patients with peptic ulcer disease(PUD)and those undergoing endoscopic submucosal dissection(ESD)is routinely being performed.Conflicting evidence exists regarding efficacy,risk,benefit,and cost-effectiveness.AIM To identify the role and effectiveness of SLE in ESD and PUD,associated rebleeding and PUD-related outcomes like mortality,hospital length of stay,need for endoscopic or surgical intervention and blood transfusions.METHODS A systematic review of literature databases PubMed,Cochrane,and Embase was conducted from inception to January 5,2023.Randomized controlled trials that compared patients with SLE to those who did not have SLE or evaluated the role of prophylactic hemostasis during SLE compared to other conservative interventions were included.The study was conducted per PRISMA guidelines,and the protocol was registered in PROSPERO(ID CRD42023427555:).RevMan was used to perform meta-analysis,and Mantel-Haenszel Odds ratio(OR)were generated using random effect models.RESULTS A total of twelve studies with 2687 patients were included in our systematic review and meta-analysis,of which 1074 patients underwent SLE after ESD and 1613 patients underwent SLE after PUD-related bleeding.In ESD,the rates of rebleeding were 7%in the SLE group compared to 4.4%in the non-SLE group with OR 1.65,95%confidence intervals(CI)of 0.96 to 2.85;P=0.07,whereas it was 11%in the SLE group compared to 13%in the non-SLE group with OR 0.895%CI:0.50 to 1.29;P=0.36.The mean difference in the blood transfusion rates in the SLE and no SLE group in PUD was OR 0.01,95%CI:-0.22 to 0.25;P=0.91.In SLE vs non-SLE groups with PUD,the OR for Endoscopic intervention was 0.29,95%CI:0.08 to 1.00;P=0.05 while it was OR 2.03,95%CI:0.95 to 4.33;P=0.07,for surgical intervention.The mean difference in the hospital length of stay was-3.57 d between the SLE and no SLE groups in PUD with 95%CI:-7.84 to 0.69;P=0.10,denoting an average of approximately 3 fewer days of hospital stay among patients with PUD who underwent SLE.For mortality between SLE and non-SLE groups in PUD,the OR was 0.88,95%CI:0.45 to 1.72;P=0.70.CONCLUSION SLE does not confer any benefit in preventing ESD and PUD-associated rebleeding.SLE also does not provide any significant improvement in mortality,need for interventions,or blood transfusions in PUD patients.SLE decreases the hospital length of stay on average by 3.5 d in PUD patients.
基金grants from the 863 program of China (No.2006AA02Z158)Wuhan Development Program of China (No. 2003500201628)
文摘The effects of survivin antisense RNA on proliferation of leukemia cell line HL-60 and taxol-induced chemotherapy was explored. A cDNA fragment of survivin obtained by RT-PCR was inserted into a plamid vector named pcDNA3 in the reverse direction. The vector encoding antisense RNA of survivin was confirmed by restriction enzyme digestion and DNA sequencing. The recombinant plasmid was delivered into HL-60 cells by electroporation. Growth curves were plotted based on cell counting. Trypan blue dye exclusion assay and MTT assay were carried out after the cells were incubated with taxol. DNA gel electrophoresis and nuclear staining were performed for cell apoptosis assay. The correct construction of the recombinant plasmid has been identified by restriction enzyme digestion and DNA sequencing. A stable down-regulation has been achieved in HL-60 SVVas cells after G418 selection. Compared to HL-60 cells, the proliferation of HL-60 SVVas cells was significantly inhibited (P〈0.05). Cytotoxicity assays indicated that IC50 of HL-60 SVVas for taxol was relatively lower than controls (P〈0.01). Apoptosis assays revealed that taxol-induced apoptosis was detected in HL-60 SVVas cells incubated with 50 ng/ml taxol for 12 h, while in HL-60 cells incubated with 100 ng/ml taxol for 72 h. It was suggested that Survivin antisense RNA could inhibit the proliferation of HL-60 cells and enhance taxol-induced apoptosis in HL-60 cells, which may lay an experimental foundation for further research on gene therapy in leukemia.
基金supported by the National Natural Science Foundation of China[Grant No.31870697].
文摘Azalea is a general designation of Rhododendron in the Ericaceae family.Rhododendron not only has high ornamental value but also has application value in ecological protection,medicine,and scientific research.In this study,we used Illumina and PacBio sequencing to assemble and annotate the entire chloroplast genomes(cp genomes)of four Rhododendron species.The chloroplast genomes of R.concinnum,R.henanense subsp.lingbaoense,R.micranthum,and R.simsii were assembled into 207,236,208,015,207,233,and 206,912 bp,respectively.All chloroplast genomes contain eight rRNA genes,with either 88 or 89 protein-coding genes.The four cp genomes were compared and analyzed by bioinformatics,and the phylogenetic analysis based on chloroplast genomes of 26 species of Ericaceae,Actinidiaceae,and Primulaceae under Ericales was conducted.A comparison of the linear structure of cp genomes of four Rhododendron showed that there were substantial sequence similarities in coding regions,but high differences in non-coding regions.A phylogenetic analysis,based on chloroplast whole genome sequences,showed that all Rhododendron species are in the clade Ericaceae.This study provides valuable genetic information for the study of population genetics and evolutionary relationships in Rhododendron and other azalea species.
基金supported by the National Natural Science Foundation of China[Grant No.31870697].
文摘Background:Acer griseum Pax is an endangered species endemic to China with both ornamental and economic value.However,the lack of information on its genome size and characteristics hinders further work at the genome level.Methods:This paper applied bioinformatics methods to predict the characteristics and patterns of the A.griseum genome,providing an important basis for formulating its whole-genome sequencing scheme.This study also characterized the simple sequence repeats(SSRs)of A.griseum,laying the foundation for the development and application of genome-wide SSR markers.In this study,PE150 sequencing was performed by the BGI MGISEQ platform,and the sequence files were analyzed by the K-mer method to estimate the characteristic information by GCE software.Results:The genome size was finally determined to be 739.63 Mb,its heterozygosity ratio was 1.33%,and the repetition ratio was 65.68%.A total of 825,960 SSR loci were identified in the assembled genome sequence,and primers were successfully designed for 526,020 loci.To verify the effectiveness of these primers,100 pairs of primers were randomly selected and synthesized,and 81 pairs successfully amplified the target fragments.Fourteen pairs of primers with good polymorphism were selected for principal component analysis of 31 A.griseum individuals from two populations,showing favorable heterozygosity and PIC values.According to the findings,these SSRs might identify genetic variations based on geographic areas.Conclusion:It is suggested that Illumina+PacBio assembly strategy should be used for whole-genome sequencing due to the high heterozygosity rate and high repetition rate of the genome.In addition,the SSR primers designed in batches in this study laid a foundation for the in-depth study of population structure and population maintenance mechanism of A.griseum,which is helpful for the effective conservation and sustainable utilization of this germplasm resource.
基金The National Natural Science Foundation of China under contract Nos 32170127 and 42176156the Fundamental Research Funds for the Central Universities under contract No.202141006。
文摘Large numbers of bacteria live on the surface of various brown algae and can produce alginate lyases to consume alginate,an important component of the cell wall of brown algae.Sargassum is a genus of the largest canopyforming brown algae of more than 150 species,which are widely distributed in tropical and subtropical environments.However,our knowledge about the epiphytic bacteria and the alginate lyase-excreting bacteria from Sargassum is still primitive.Here,we investigated the diversity of the culturable epiphytic bacteria and alginate-degrading bacteria from Sargassum samples collected from the coastal seawaters of Shandong Province,China.In total,37 strains belonging to 21 genera in 3 phyla were isolated,including 15 previously unreported genera,of which Vibrio(6/37)and Pseudoalteromonas(5/37)are the dominant genera.Eight strains,mainly Vibrio and Pseudoalteromonas species,were further identified as alginate lyase-excreting strains that can utilize alginate for growth.The extracellular alginolytic activity of the 8 strains was determined,and strains Vibrio sp.C42and Pseudoalteromonas sp.M9 showed the highest activity.These results provide a better understanding of brown algae epiphytes and alginate-degrading bacteria,and are fundamental for further studies on the interactions between brown algae and their epiphytes.
基金This work is supported by the Key Project of the National Natural Science Foundation of China(Grant Number 62135003)the Science and Technology Program of Guangzhou(Grant No.202201010704)Special Carrier Program of Qingyuan Hitech Industrial Development Zone.
文摘The automatic and accurate identification of apoptosis facilitates large-scale cell analysis.Most identification approaches using nucleus fluorescence imaging are based on specific morphological parameters.However,these parameters cannot completely describe nuclear morphology,thus limiting the identification accuracy of models.This paper proposes a new feature extraction method to improve the performance of the model for apoptosis identification.The proposed method uses a histogram of oriented gradient(HOG)of high-frequency wavelet coefficients to extract internal and edge texture information.The HOG vectors are classified using support vector machine.The experimental results demonstrate that the proposed feature extraction method well performs apoptosis identification,attaining 95:7% accuracy with low cost in terms of time.We confirmed that our method has potential applications to cell biology research.
基金supported by the National Natural Science Foundation of China (62075066)Guangdong Basic and Applied Basic Research Foundation (2021A1515011285,2019A1515010800)+1 种基金Major Project under the Science and Technology Development Scheme of Guangdong Province (210715106900918,[2020]53-129)Shantou Science and Technology Plan Medical and Health Category Project (211114216492935).
文摘Bioprobe based on fluorescence is widely used in biological and medical research due to its high sensitivity and selectivity.Yet,its quantification in vivo is complicated and often compromised by the interaction between the fluorophore with the environmental factors,as well as the optical scattering and absorption by the tissue.A high florescence quantum yield and minimal interference by the environment are key requirements for designing an effective bioprobe,and the prerequisitions severely limit the available options.We propose that a comprehensive evaluation of potential bioprobe can be achieved by simultaneously measuring both radiative and nonradiative transitions,the two fundamental and complementary pathways for the energy de-excitation.This approach will not only improve the accuracy of the quantification by catching the information from a broader spectrum of the energy,but also provide additional information of the probe environment that often impacts the balance between the two forms of the energy transition.This work first analyzes the underlying mechanism of the hypothesis.The practical feasibility is then tested by means of simultaneous measurements of photoacoustic signal for the non-radiative and fluorescence for the radiative energy processes,respectively.It is demonstrated that the systematic evaluation of the probe energy de-excitation results in an improved quantitative tracing of a bioprobe in complex environment.
基金Supported by China Agricalture Research System of MOF and MARA(CARS-26)Citrus Germplasm Resources Nursery Construction Project in Sihui City of Guangdong Province(KJ-20230310-H010)。
文摘[Objectives]To protect the local rare citrus germplasm resources and further develop and cultivate new citrus varieties.[Methods]The germplasm resources of Shatangju(Citrus flamea Hort.Ex Tseng Shiyueju)in Sihui City of Guangdong Province and other 8 citrus varieties from the same origin were evaluated.The appearance characteristics of tree shape,the length and thickness of shoot at each shoot stage,the appearance characteristics of leaves and the fruit quality of each variety were investigated.[Results]Through the comparison of various citrus varieties grafted with sour mandarin,the results showed that the overall advantages of the length and thickness of the shoots of Shatang tangerine in summer and autumn were more prominent,which was conducive to fruit setting.The sprouting time of the three shoots of each variety was different,and there were sporadic sprouting phenomena in different seasons,so the growth was different,and the length and thickness of the shoots were different in different seasons.There were significant differences in shoot length and diameter among different varieties in the same season.The coefficient of variation of Shatangju's leaves was low,and the traits were stable;leaf shape,leaf base shape,leaf margin and other indicators among the three shoots of the same variety and the differences among the same shoots of different varieties were compared.All varieties had strong flavor,separately sweet and sour,sweet and sweet taste.Shatangju has many segments,orange pericarp,rough texture,easy peeling,and high oblate fruit shape.The orange pericarp was favored by the participants,while the rough and thick peel was not favored by the participants.[Conclusions]Based on the improvement of local varieties,it is recommended to improve the smoothness of pericarp,reducing the thickness of pericarp and improving the flavor of fruit will be conducive to increasing sales.In the cultivation process of various quality resources,especially in the period of fruit growth and development,the plan of nutrition and fertilization should be formulated according to the rules of fruit growth and development,the rules of yield formation and the rules of quality composition,so as to establish the integrated nutrient management system of various varieties.
基金This research was supported by the National Natural Science Foundation of China(62075066)the Science and Technology Planning Project of Guangdong Province,China(2019A1515012054)+2 种基金the Science and Technology Program of Guangzhou(2019050001)the Science and Technology Program of Guangzhou(202201010718)the Key-Area Research and Development Program of Guangdong Province(2019B030335001).
文摘As an emerging hybrid imaging modality,microwave-induced thermoacoustic imaging(MTAI),using microwaves as the excitation source and ultrasonic signals as the information carrier for combining the characteristics of high contrast of electromagnetic imaging and high resolution of ultrasound imaging,has shown broad prospects in biomedical and clinical applications.The imaging contrast depends on the microwave-absorption coe±cient of the endogenous imaged tissue and the injected MTAI contrast agents.With systemically introduced functional nanoparticles,MTAI contrast and sensitivity can be further improved,and enables visualization of biological processes in vivo.In recent years,functional nanoparticles for MTAI have been developed to improve the performance and application range of MTAI in biomedical applications.This paper reviews the recent progress of functional nanoparticles for MTAI and their biomedical applications.The challenges and future directions of microwave thermoacoustic imaging with functional nanoparticles in theeld of translational medicine are discussed.
文摘BACKGROUND Non-alcoholic fatty liver disease(NAFLD)and metabolic-associated fatty liver disease(MAFLD)are on the rise like any other liver disease,and tend to affect 25%of the United States population.The impact of NAFLD and MAFLD on patients with coronavirus disease 2019(COVID-19)remains unclear.AIM To identify the association of NAFLD and MAFLD with mortality,hospitalization,hospital length of stay,and supplemental oxygen utilization in COVID-19 patients.METHODS A systematic review of literature on Cochrane,Embase,PubMed,ScienceDirect,and Web of Science databases was conducted from January 2019 to July 2022.Studies that evaluated NAFLD/MAFLD using laboratory methods,noninvasive imaging,or liver biopsy were included.The study protocol was registered in PROSPERO(ID CRD42022313259)and PRISMA guidelines were followed.The National Institutes of Health quality assessment tool was used to assess the quality of the studies.Pooled analysis was conducted using software Rev Man version 5.3.The stability of the results was assessed using sensitivity analysis.RESULTS Thirty-two studies with 43388 patients were included in the meta-analysis of whom 8538(20%)patients were observed to have NAFLD.There were 42254 patients from 28 studies included in the mortality analysis.A total of 2008 patients died from COVID-19;837(10.52%)in the NAFLD group and 1171(3.41%)in the non-NAFLD group.The odds ratio(OR)was 1.38 for mortality with a 95%confidence interval(95%CI)=0.97-1.95 and P=0.07.A total of 5043 patients from eight studies were included in the hospital length of stay analysis.There were 1318 patients in the NAFLD group and 3725 patients in the non-NAFLD group.A qualitative synthesis showed that the mean difference in hospital length of stay was about 2 d between the NAFLD and non-NAFLD groups with a 95%CI=0.71-3.27 and P=0.002.For hospitalization rates,the OR was 3.25 with a 95%CI of 1.73-6.10 and P=0.0002.For supplemental oxygen utilization,the OR was 2.04 with a 95%CI of 1.17-3.53 and P=0.01.CONCLUSION Our meta-analysis suggests that there are increased odds of hospitalization,longer hospital length of stay,and increased use of supplemental oxygen in NAFLD/MAFLD patients.
基金supported by the National High Technology Research and Development Program of China (863 Program, 2006AA10Z1A4)the Innovation Team of the Northeast Agricultural University, China (LXT005-1-2)the Talents Foundation of Northeast Agriculture Univesity, China (2010RCB47)
文摘In previous experiment, we isolated a compound dibutyl phthalate (DBP) from Vaccaria segetalis which had galactopoietic function on mammary gland epithelial cells of dairy cow (DCMECs). In this experiment, we ascertained the metabolic regulation function of DBP on DCMECs. Many genes related to lactation including Stat5, AMPK, b-casein, Glut1, SREBP-1, PEPCK, and ACC were detected by real-time PCR. Furthermore, Stat5 and AMPK were detected by Western blot and immunofluorescence co-localization, respectively. The results showed that DBP stimulates the expression of Stat5 and p-Stat5, thus activates Stat5 cell signal transduction pathway and stimulates b-casein synthesis. DBP also raises the activities of Glut1 and AMPK to stimulate glucose uptake and glycometabolism and activates the expression of AMPK downstream target genes PEPCK and ACC and expression of SREBP-1 to stimulate milk fat synthesis. In addition, the activities of HK, G-6-PDH, ICDH, ATPase, and energy charges were stimulated by DBP to increase the energy metabolism level of DCMECs. The results showed DBP stimulates energy metabolism related to galactopoietic function in DCMECs.
基金Project supported by the National Key Basic Research Program (973 Program) of China (No.2002CB111506)the Knowledge Innovation Program of the Chinese Academy of Sciences (No. KZCX3-SW-418)the National Programs for Science and Technology Development of China (No. 2005BA517A03)
文摘A field experiment was conducted at Kezuohouqi County, Inner Mongolia Autonomous Region of China, which was located on the southeastern edge of the Horqin Sandy Land, to study the spatial variability of soil nutrients for a smallscale, nutrient-poor, sandy site in a semi-arid region of northern China; to investigate whether or not there were 'islands of fertility' at the experimental site; and to determine the key nutrient elements that sustained ecosystem stability. Results obtained from geostatistical analysis indicated that the spatial distribution pattern of soil total nitrogen (STN) was far different from those of soil organic matter (SOM), total phosphorus (STP), and total potassium (STK). Compared to SOM, STP, and STK, STN had a lower structural heterogeneity ratio and a longer range, while other elements were all similar. In addition, STN had an isotropic spatial structure, whereas the others had an anisotropic spatial structure. The spatial structure patterns of herbage species, cover,and height also differed, indicating that spatial variability was subjected to different ecological factors. Differences in the spatial variability patterns among soil nutrients and vegetation properties showed that soil nutrients for a small-scale were not the primary limiting factors that influenced herbage spatial distribution patterns. Incorporating spatial distribution patterns of tree species, namely, Pinus sylvestris var. mongolica Litv. and shrub Lespedeza bicolor Turcz. in a research plot and using fractal dimension,SOM, STP, and STK were shown to contribute to the 'islands of fertility' phenomenon, however STN was not, possibly meaning that nitrogen was a key limiting element. Therefore, during restoration of similar ecosystems more attention should be given to soil nitrogen.
文摘The effect and the mechanism of action of lanthanum, cerium and neodymium on aged seeds of spinach were studied. By LaCl_3, CeCl_3, and NdCl_3 treatment, the germination rate, germination index and vigor index of aged spinach seeds are increased and the activities of superoxide dismutase, catalase and peroxidase are enhanced. Moreover the ·O_2^- and malondialdehyde content are decreased and the cell membrane permeability of aged spinach seeds is reduced. Among these three rare earth elements, Ce treatment enhances vigor of aged seeds most significantly, that of Nd treatment secondly and La treatment is not as effective as the other two treatments. The reason may be from 4f electron characteristic and alternation valence of REEs.
文摘Objective To study the regulating effects of a novel CpG oligodeoxynuleotide and the synergistic effect of chitosan-nanoparticles (CNP) with CpG on immune responses of mice, which were used to develop a novel immunoadjuvant to boost immune response to conventional vaccines. Methods A novel CpG ODN containing 11 CpG motifs was synthesized and its bioactivities to stimulate the proliferation of lymphocytes of pig in vitro were detected. Then it was entrapped with CNP prepared in our laboratory by the method of ionic cross linkage, and immunized Kunming mice were co-inoculated with paratyphoid vaccine. The peripheral blood was collected weekly from the tail vein of inoculated mice to detect the contents of IgG, IgA, IgM, and specific antibody against salmonella as well as the levels of interleukin-2 (IL2), IL-4, and IL-6 by SABC-ELISA assay. The numbers of leucocytes, monocytes, granuloytes, and lymphocytes were calculated separately using the routine method. The experimental mice were orally challenged with virulent salmonella 35 days after inoculation. Results This CpG ODN could remarkably provoke the proliferation of lymphocytes of pig in vitro in contrast with the control (P〈0.05). Compared with those of the control, immunoglobulins, including IgG, IgA, IgM, and specific antibodies to paratyphoid vaccine, increased significantly in sera from the CpG or CpG-CNP-vaccinated mice (P〈0.05). IL-2, IL-4, and IL-6 increased remarkably in sera from immunized mice (P〈0.05). The leucocytes, monocytes, granuloytes, and lymphocytes of the mice immunized with CpG or CpG-CNP were also increased in number (P〈0.05). After the challenge, these immunity values were elevated in the mice vaccinated with CpG or CpG-CNP. The immunized mice all survived, while the control mice fell ill with evident lesions with diffuse hemorrhage in stomach, small intestine, and peritoneum. Conclusions CpG ODN entrapped with CNP is a promising effective immunoadjuvant for vaccination, which promotes humoral and cellular immune responses, enhances immunity and resistance against salmonella by co-administration with paratyphoid vaccine. Key words:
基金the National Key Basic Research Program (973 Program) of China (No. 2007CB106803)the Knowledge Innovation Program of the Chinese Academy of Sciences (No. KZCX1-YW-08-02)the Key Laboratory of Terrestrial Ecological Process and Regional Ecological Safety in Liaoning Province, China (No. 06ZDS212SS).
文摘The dynamics of soil inorganic nitrogen (NH4+ -N and NO-3 -N) and microbial biomass carbon (Cmic) and nitrogen (Nmic) under 30-year-old fenced Pinus sylvestris L. var. mongolica Litvin (SF), unfenced P. sylvestris L. var. mongolica Litvin (SUF), and unfenced Pinus densiflora Siebold et Zucc. (DUF) plantations in the Zhanggutai sandy soil of China were studied during Apr. to Oct. 2004 by the in situ closed-top core incubation method. All mentioned C and N indices in each stand type fluctuated over time. The ranges of inorganic N, Cmic, and Nmic contents in the three stand types were 0.7–2.6, 40.0–128.9, and 5.4–15.2 μg g-1, respectively. The average contents of soil NH4+ -N and Cmic under the three 30-year-old pine plantations were not different. However, soil NO3 -N and total inorganic N contents decreased in the order of SUF ≥ SF ≥ DUF, the Nmic content was in the order of SF = SUF > DUF, and the Cmic:Nmic ratio was in the order of SUF = DUF > SF. Seasonal variations were observed in soil inorganic N, microbial biomass, and plant growth. These seasonal variations had certain correlations with microbe and plant N use in the soil, and their competition for NH+4 -N was mostly regulated by soil N availability. The influence of tree species on inorganic N and Nmic were mainly because of differences in litter quality. Lack of grazing decreased the Cmic:Nmic ratio owing to decreased carbon output and increased the ability of soil to supply N. The soil N supply under the P. sylvestris var. mongolica plantation was lower than under the P. densiflora plantation.
文摘Rare earth elements(REE)are applied as micro-fertilizer in large scale in China and there is growing concern about the environmental effects of REE accumulation in soils. Accumulation of REE was simulated in lab by adding REE to three soils and the survival of Pseudomonas fluorescence X16 strain marked with luxAB gene in soils was detected. Curvilinear regression method was applied to analyze the survival pattern. The stimulation values, EC_(50) and NOEC values for X16 strain were calculated to compare the toxic intensity of REE in different soils. The stimulation(peak)values in red soil, yellow fluovo-aquic soil and yellow cinnamon soil, are 11.55~18.08,(0~2.13), 2.37~4.62 mg·kg^(-1) , respectively. EC_(50) values are 13.47~39.12, 6.59~56.18, 372~1034 (mg·kg^(-1)), respectively.NOEC values are 5.62 ~21.41, 0.00~4.53, 133.3~327.1 mg·kg^(-1), respectively. Tangents values of regression equation of the survival of X16 strain in red soil are the maximum ones indicating that REE accumulation in red soil has stronger inhibitory effects than in other two soils. The soil order, reflecting toxic intensity of REE is as follows: red soil>yellow fluovic-aquic soil>yellow cinnamon soil.
基金This work was supported by a fund for doctorate candidate scientific research from the Ministry of Education (98042303)doctor start fund of Suzhou University (Q4114928)
文摘Vegetative cells of Porphyra yezoensis are isolated with sea snail enzyme and cultured on the solidified agar medium. The results of experiments show that the isolated cells can survive,divide and regenerate well on the medium solidified with agar. The first division on the solid medium starts after 7 days' culture, 4 days later than the liquid culture. The survival rate of isolated cells is 71.3% on the solid medium, lower than the 86.2% of that in seawater.Thalli, thalloids,conchocelis, spermatangia and multicellular masses are developed on the solid/medium in the first month, slowly but normally. Spermatangia sacs disappear within 4 weeks. Without adding nutrient liquid onto the surface of solid medium or injecting seawater under the agar layer in order to keep moisture, the thalli and cell groups release monospores to form new thalli instead of enlarging their areas after 5 weeks' culturing. Some monospores regenerate new thalli. Other monospores lose their pigments and minimize their volume and divide quickly to form light pink calli. After 16 weeks, numerous calli can be seen on the solid medium and after 24 weeks' culturing, almost only calli and conchocelis can be seen. If the calli are immersed in seawater, the monospores are released and may develop into young thallus.
基金This work was supported by the National Natural Science Foundation of China under contract Nos 30270258 and 40506028 the National High Technology Research and Development Program of China under contract No. 2002AA648010+2 种基金 the China Postdoctoral Science Foundation under contract No. 2005037237 the Shandong Scientific Research Encouragement Foundation for Talent Youths under contract No. 03BS120the Doctor Scientific Research Foundation of Dongying Vocational College under contract No. B J0602.
文摘Effect of UV - B radiation on the feeding behaviour of marine zooplankton is important to assessing the health harm of marine ecosystem due to the gradually enhanced UV - B radiation in air. However, there are a few studies on this topic. The feeding behavior of the rotifer, Brachionus plicatilis, under the treatment of UV - B radiation on five species of microalgae, i. e. , Chlorella sp. , Tetraselmis chuii, Isochrysis galbana Park 8701, Chaetoceros muelleri Lermumerman, and Nitzschia clostertum, was studied. The results showed that the filtering and feeding rates of the rotifer decreased significantly with the dose increase of UV - B radiation when fed with five species of microalgae respectively ( P 〈 0.05 ) which indicates UV - B radiation inhibits the feeding activities of the rotifer on microalage. The mixed culture experiments shows the rotifer preferred to feed Chlorella sp. , then C. muelleri, L galbana, N. clostertum and T. chuii in turn if without UV - B radiation. Under the highest dose of UV - B radiation treatment (2.70 kJ/m^2), the rotifer preferred to feed C. muelleri, then Chlorella sp. , N. clostertum, L galbana and T. chuii in turn. Chlorella sp. , L galbana and C. muelleri became the more favorite foods of the rotifer while T. chuii and N. clostertum became less favorite foods. The change of feeding rate and feeding selectivity of zooplankton driven by the enhanced UV - B radiation will lead to the change in the structure of phytoplankton community.