356 research outputs found

    Spatial Heterogeneity in Light Supply Affects Intraspecific Competition of a Stoloniferous Clonal Plant

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    Spatial heterogeneity in light supply is common in nature. Many studies have examined the effects of heterogeneous light supply on growth, morphology, physiology and biomass allocation of clonal plants, but few have tested those effects on intraspecific competition. In a greenhouse experiment, we grew one (no competition) or nine ramets (with intraspecific competition) of a stoloniferous clonal plant, Duchesnea indica, in three homogeneous light conditions (high, medium and low light intensity) and two heterogeneous ones differing in patch size (large and small patch treatments). The total light in the two heterogeneous treatments was the same as that in the homogeneous medium light treatment. Both decreasing light intensity and intraspecific competition significantly decreased the growth (biomass, number of ramets and total stolon length) of D. indica. As compared with the homogeneous medium light treatment, the large patch treatment significantly increased the growth of D. indica without intraspecific competition. However, the growth of D. indica with competition did not differ among the homogeneous medium light, the large and the small patch treatments. Consequently, light heterogeneity significantly increased intraspecific competition intensity, as measured by the decreased log response ratio. These results suggest that spatial heterogeneity in light supply can alter intraspecific interactions of clonal plants

    Crystal engineered acid–base complexes with 2D and 3D hydrogen bonding systems using p-hydroxybenzoic acid as the building block

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    p-Hydroxybenzoic acid (p-HOBA) was selected as the building block for self-assembly with five bases, i.e., diethylamine, tert-butylamine, cyclohexylamine, imidazole and piperazine, and generation of the corresponding acid–base complexes 1–5. Crystal structure analyses suggest that proton-transfer from the carboxyl hydrogen to the nitrogen atom of the bases can be observed in 1–4, while only in 5 does a solvent water molecule co-exist with p--HOBA and piperazine. With the presence of O–H···O hydrogen bonds in 1–4, the deprotonated p-hydroxybenzoate anions (p-HOBAA–) are simply connected each other in a head-to-tail motif to form one-dimensional (1D) arrays, which are further extended to distinct two-dimensional (2D) (for 1 and 4) and three-dimensional (3D) (for 2 and 3) networks via N–H···O interactions. While in 5, neutral acid and base are combined pair-wise by O–H···N and N–H···O bonds to form a 1D tape and then the 1D tapes are sequentially combined by water molecules to create a 3D network. Some interlayer or intralayer C–H···O, C–H···p and p×××p interactions help to stabilize the supramolecular buildings. Melting point determination analyses indicate that the five acid–base complexes are not the ordinary superposition of the reactants and they are more stable than the original reactants

    Gender differences in age-related decline in glomerular filtration rates in healthy people and chronic kidney disease patients

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    Background: Since men with chronic kidney disease (CKD) progress faster than women, an accurate assessment of CKD progression rates should be based on gender differences in age-related decline of glomerular filtration rate (GFR) in healthy individuals. Methods: A Chinese sample population from a stratified, multistage, and clustered CKD screening study was classified into healthy, at-risk, and CKD groups. The gender differences in estimated GFR (eGFR) and age-related eGFR decline were calculated for each group after controlling for blood pressure, fasting glucose levels, serum lipids levels, education level, and smoking status. After referencing to the healthy group, gender-specific multivariate-adjusted rates of decline in eGFR and differences in the rates of decline were calculated for both CKD and at-risk groups. Results: The healthy, at-risk, and CKD groups consisted of 4569, 7434, and 1573 people, respectively. In all the 3 groups, the multivariate-adjusted eGFRs in men were lower than the corresponding eGFRs in women. In addition, in the healthy and at-risk groups, the rates of decline in eGFR in men were lower than the corresponding rates of decline in women (healthy group: 0.51 mL.min(-1).1.73 m(-2).yr(-1) vs. 0.74 mL.min(-1).1.73 m(-2).yr(-1) and at-risk group: 0.60 mL.min(-1).1.73 m(-2).yr(-1) vs. 0.73 mL.min(-1).1.73 m(-2).yr(-1)). However, in the CKD group, the rates of decline in eGFR in men were similar to those in women (0.96 mL.min(-1).1.73 m(-2).yr(-1) vs. 0.91 mL.min(-1).1.73 m(-2).yr(-1)). However, after referencing to the healthy group, the rates of decline in eGFR in men in the at-risk and CKD groups were greater faster than the corresponding rates in women (at-risk group: 0.10 mL.min(-1).1.73 m(-2).yr(-1) vs. -0.03 mL.min(-1).1.73 m(-2).yr(-1) and CKD group: 0.44 mL.min(-1).1.73 m(-2).yr(-1) vs. 0.15 mL.min(-1).1.73 m(-2).yr(-1)). Conclusion: To accurately assess gender differences in CKD progression rates, gender differences in age-related decline in GFR should be considered.Urology & NephrologySCI(E)PubMed12ARTICLE201

    Immune Responses in Mice Immunized with Mastitis Multiple Vaccines Using Different Adjuvants

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    Background: Bovine mastitis, a serious disease associated with both high incidence and significant economic losses, posing a major challenge to the global dairy industry. The development of vaccines for protection from new infections by mastitis pathogens is of considerable interest to the milk production industry. Vaccination is a common and easy strategy for the control of infectious diseases, and the adjuvants used in the formulation is a critical factor for vaccine efficacy improvement. The main objective of the present study was to evaluate three different adjuvants for their ability to enhance immune responses of mice that vaccinated with Bovine Mastitis Multiple Vaccine.Materials, Methods & Results: The thymus and spleen index, the phagocytic ability of macrophage and the serum antibody levels of mice were detected after vaccination, respectively. The results showed that the thymus index, spleen index, and the phagocytic ability of macrophage of mice in Aluminum group exhibited a significant higher level (P < 0.05) compared with those in the control groups. The difference of the serum antibody levels was significant (P < 0.05) between experimental groups and control group after vaccination. The serum antibody concentration of mice in FIA group was higher compared with other groups and had a longer duration. The antibody concentration of mice in France 206 oil group can not increase as fast as the antibody concentration of Aluminum group, but it can last a longer time at a high level. In conclusion, multiple vaccines mixed with three different adjuvants could enhance the immunity of mice and Freund’s incomplete adjuvant is the best choice for this vaccine.Discussion: Adjuvants play an important role in increasing the efficacy of a number of different vaccines. In this study, three kinds of adjuvants (Aluminum hydroxide, France 206 oil and FIA) were evaluated for their adjuvant effects for multiple vaccine of bovine mastitis in mice and aluminum hydroxide did best as the vaccine adjuvant from the results. Aluminum hydroxide is a universally accepted adjuvant for both human and veterinary vaccines. The goal of vaccination is to generate strong immune response providing protection against infection for a time. Different protective effects will usually obtained by different adjuvants even use same antigen. In this work, FIA, Alum and 206 oil were chosen as adjuvants for inactivated antigens of Streptococcus agalactiae, Streptococcus dysgalactiae and Staphylococcus aureus. The results showed that there was a significantly higher antibody levels in vaccinated mice compared with those in control group. In addition, the mice in France 206 oil and FIA group performed a higher antibody levels and stronger immunity than mice in Aluminum hydroxide groups. These findings suggest that Freund’s incomplete adjuvant (FIA) would be the best candidate as the adjuvant for mastitis multiple vaccines investigated in this study

    Phycobiliproteins: Molecular Structure, Production, Applications, and Prospects

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    Phycobiliproteins (PBPs) are the main component of light-harvesting complexes in cyanobacteria and red algae. In addition to their important role in photosynthesis, PBPs have many potential applications in foods, cosmetics, medical diagnosis and treatment of diseases. However, basic researches and technological innovations are urgently needed for exploring those potentials, such as structure and function, their biosynthesis as well as downstream purification. For medical use and application, mechanisms underlying their therapeutic effects must be elucidated. Focusing on these issues, this article gives a critical review on the current status on PBPs, including their structures and functions, preparation processes and applications. In addition, key technical challenges and possible solutions are prospected

    Interaction between Thalamus and Hippocampus in Termination of Amygdala-Kindled Seizures in Mice

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    The thalamus and hippocampus have been found both involved in the initiation, propagation, and termination of temporal lobe epilepsy. However, the interaction of these regions during seizures is not clear. The present study is to explore whether some regular patterns exist in their interaction during the termination of seizures. Multichannel in vivo recording techniques were used to record the neural activities from the cornu ammonis 1 (CA1) of hippocampus and mediodorsal thalamus (MDT) in mice. The mice were kindled by electrically stimulating basolateral amygdala neurons, and Racine’s rank standard was employed to classify the stage of behavioral responses (stage 1~5). The coupling index and directionality index were used to investigate the synchronization and information flow direction between CA1 and MDT. Two main results were found in this study. (1) High levels of synchronization between the thalamus and hippocampus were observed before the termination of seizures at stage 4~5 but after the termination of seizures at stage 1~2. (2) In the end of seizures at stage 4~5, the information tended to flow from MDT to CA1. Those results indicate that the synchronization and information flow direction between the thalamus and the hippocampus may participate in the termination of seizures

    Distribution of Serotypes, Antimicrobial Resistance and Virulence Genes among Streptococcus agalactiae Isolated from Bovine in China

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    Background: Bovine mastitis, a global disease that is responsible for large economic losses each year due to lower milk yield and reduced milk quality. In some countries, especially in China, Streptococcus agalactiae has become one of the most frequently detected pathogen. Antibiotic treatment and vaccine immunization are important strategies for the control of infectious diseases. The main objective of the present study was to evaluate distribution of bovine mastitis pathogens and antimicrobial resistance of S. agalactiae, and contribute to the treatment of bovine mastitis.Materials, Methods & Results:Clinical mastitis samples (n= 1,122) were collected from 27 dairy farms located in 15 different provinces of China during 2012-2018. Thepathogens were identified by 16S rDNA method. Antimicrobial susceptibility was assessed by disc diffusion method. Molecular characteristics was distinguished based on PCR. The results showed that the main pathogens were Streptococcus agalactiae (n= 324, 26.2%), Escherichia coli (n= 287, 23.2%), and Staphylococcus aureus (n= 131, 10.6%). The serotypes of Streptococcus agalactiae were serotype II (53.6%), Ia (44 %) and VII (1.2%), respectively. Streptococcus agalactiae were resistant to kanamycin (93.8%), gentamicin (49.4%), vancomycin (49.4%), tetracycline (35.8%), clindamycin (34.6%) and erythromycin (32.1%). The main resistance genes were ermA (53.1%) and ermB (85.2%). Resistance to erythromycin was attributed to the genes ermA (P < 0.05) and resistance to tetracycline was attributed to the genes tetK, tetM, tetO (P < 0.01). The virulence genes scpB (81.4%), cyl (100%), glnA (76.6%), cfb (98.8%), hylB (98.8%), scaA (69.1%) were detected in almost all isolates.Discussion: In the present study, Streptococcus agalactiae, Escherichia coli and Staphylococcus aureus were the pathogens isolated most frequently from clinical mastitis. In the case of S. agalactiae, we performed capsular serotyping of isolates. As a result, serotype II (53.6%), Ia (44 %) and VII (1.2%) were detected whichrevealed variation in the distinct geographical areas. We found that serotypes (Ia and II) and β-hemolytic have significant correlation (P < 0.01) in all isolated strains. We made an assumption that either in processes of capsular and haemolytic appearance effected the expression of another. The unclear mechanism remains to be resolved in the future. Penicillin was recommended as a preferred antibiotic for the treatment of both human and bovine S. agalactiae infection. In the present study, resistance to erythromycin and clindamycin were observed in 32% and 34.6% of our strains, respectively. The results indicated that the ermB gene was most frequent among the erythromycin-resistant S. agalactiae. However, we found that the susceptibility to erythromycin and gene ermA have a significant interaction, while susceptibility to erythromycin and gene ermB have a not significant interaction by analyzing the relationship of phenotypic and genotypic resistance. The severity of S. agalactiae infections may be determined by various virulence factors. Surface enzyme ScpB, a C5a peptidase, encode by scpB gene, could promote bacterial invasion of epithelial cells by attenuating recruitment of polymorphonuclear leukocytes to the site of infection. In the present study, the scpB gene was found in 81.4% of all strains. The results suggested the cyl, cfb, hylB and scpB genes may play an important role in the virulence of Streptococcus agalactiae pathogens
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