Synthesis, Anti-Oomycete and Anti-Fungal Activities of Anhydride Derivatives of Oleanolic Acid.

Oleanolic acid is a pentacyclic triterpenoid extracted and isolated from the fruit of plants in the Ligustrum lucidum Ait. in the family Oleaceae. To discover biorational natural product-based pesticides, a series of oleanolic acid derivatives containing anhydride active skeletons were prepared by ingeniously introducing an active acyloxy group at its C-28 carboxyl position, and their structures were well characterized by 1H-NMR, 13C NMR, HRMS, and m.p. The stereochemical configuration of compound 8 e was confirmed using single-crystal X-ray diffraction. Furthermore, bioactivities of these compounds as anti-oomycete and anti-fungal agents against two serious agricultural pests, Phytophthora capsici (P. capsici) and Fusarium graminearum (F. graminearum) we assessed. Amongst evaluated compounds, 1) Compounds 8 h and 8 j displayed significant anti-oomycete against P. capsici, with EC50 values of 54.73 and 65.15 mg/L, respectively. 2) The target compounds have obvious selectivity, and their anti-oomycete activity is significantly better than their anti-fungal activity. 3) Interestingly, there are significant differences in the structure-activity relationship of different substituents or the same substituent at different positions anti-oomycete and anti-fungal against P. capsici and F. graminearum, respectively. The study provides an idea for further exploring the bioactivities of 28-acyloxyoleanolic acid derivatives, and develops the application of 28-acyloxyoleanolic acid derivatives containing anhydride in agriculture.

A cationic cyclodextrin derivative-lipid hybrid nanoparticles for gene delivery effectively promotes stability and transfection efficiency.

Genetic medicines hold great promise for treatment of a number of diseases; however, the development of effective gene delivery carrier is still a challenge. The commonly used gene carrier liposomes and cationic polymers have limited their clinical application due to their respective disadvantages. Lipid-polymer hybrid nanoparticles (LHNPs) are novel drug delivery system that exhibit complementary characteristics of both polymeric nanoparticles and liposomes. In this account, we developed the α-cyclodextrin-conjugated generation-2 polyamidoamine dendrimers-lipids hybrid nanoparticles (CDG2-LHNPs) for gene delivery. The pDNA/CDG2-LHNPs was stable during 15 days of storage period both at 4 °C, 25 °C, and 37 °C, whereas the particle size of pDNA/CDG2 and pDNA/liposomes dramatically increased after storage at 4 °C for 8 h. CDG2-LHNPs showed significantly superior transfection efficiencies compared to either CDG2 or liposomes. The mechanism of high transfection efficiency of pDNA/CDG2-LHNPs was further explored using pharmacological inhibitors chlorpromazine, filipin, and cytochalasion D. The result demonstrated that cell uptake of pDNA/CDG2-LHNPs was mediated by clathrin-mediated endocytosis (CME), caveolae-mediated endocytosis (CvME), and macropinocytosis together. pDNA/CDG2-LHNPs were more likely be taken up by cells through CvME, which avoided lysosomal degradation to a large extent. Moreover, the liposome component of pDNA/CDG2-LHNPs increased its cell uptake efficiency, and the CDG2 polymer component increased its proton buffer capacity, so the hybrid nanoparticles taken up by CME could also successfully escape from the lysosome. CDG2-LHNPs with stability and high-transfection efficiency overcome the shortcomings of liposomes and polymers applied separately, and have great potential for gene drug delivery.

Tailoring enzyme modified starch through high-moisture extrusion: Unraveling structure-property relationships.

The conventional method of producing enzyme modified starch (ES) involves using a dilute starch suspension, which necessitated substantial heat expenditure for drying the product and resulted in significant energy waste. Improved extrusion cooking technology (IECT) could extrude materials under high moisture, and it is a new physical modification technology. A comprehensive investigation was undertaken to produce enzyme modified starch (ES) with varying dextrose equivalent (DE) using IECT. The study systematically explored the effects of different screw speeds on the resulting IECT-ES properties. And principal component analysis and artificial neural network analysis were used to explore the correlation between data and the synaptic weight relationships. Results indicated that Maltese cross of IECT-ES disappeared, the R1047/1022 and R995/1022 decreased to 0.7305 and 0.9012 respectively, the full width at half maximum at 480 cm-1 increased to 26.81 %, light transmittance increased to 21.20 % and DE value rose to 14.19 % at 300 rpm. The properties evolution of IECT-ES was closely related to changes in structure and conditions. This study aimed to evaluate the effectiveness of IECT as an alternative method for producing enzyme modified starch. The findings provide valuable insights into more energy-efficient starch modification processes.

Influence of enzymatic modification on the basis of improved extrusion cooking technology (IECT) on the structure and properties of corn starch.

Enzymatic modification can directly affect the structure and properties of starch, but generally causes high energy consumption in drying process. Improved extrusion cooking technology (IECT) itself is a starch modification technology. In this work, a co-extrusion method of starch with 42 % moisture and enzyme was adopted to reveal the effects of different enzyme dosages on the structure and properties of corn starch. After enzyme treatment on the basis of IECT, starch granules were broken into fragments without the occurrence of clear Maltese cross. R1047/1022 and R995/1022 values, peak intensity of Raman spectra and gelatinization temperature decreased, and the full width at half maximum at 480 cm-1 of Raman spectra raised. Moreover, the bound water proportion decreased from 87.44 % to 85.84 % âˆ¼ 78.67 %, and the maximum light transmittance and dextrose equivalent values increased to 34.13 % and 26.14, respectively. The solubility of starch granules was all above 60 %. Findings supported that the mechanochemical effect of IECT on starch was conducive to the enzymatic modification.

A Multi-Context Character Prediction Model for a Brain-Computer Interface.

Brain-computer interfaces and other augmentative and alternative communication devices introduce language-modeing challenges distinct from other character-entry methods. In particular, the acquired signal of the EEG (electroencephalogram) signal is noisier, which, in turn, makes the user intent harder to decipher. In order to adapt to this condition, we propose to maintain ambiguous history for every time step, and to employ, apart from the character language model, word information to produce a more robust prediction system. We present preliminary results that compare this proposed Online-Context Language Model (OCLM) to current algorithms that are used in this type of setting. Evaluations on both perplexity and predictive accuracy demonstrate promising results when dealing with ambiguous histories in order to provide to the front end a distribution of the next character the user might type.

Strong contributions of local background climate to the cooling effect of urban green vegetation.

Utilization of urban green vegetation (UGV) has been recognized as a promising option to mitigate urban heat island (UHI) effect. While we still lack understanding of the contributions of local background climate to the cooling effect of UGV. Here we proposed and employed a cooling effect framework and selected eight typical cities located in Temperate Monsoon Climate (TMC) and Mediterranean Climate (MC) demonstrate that local climate condition largely affects the cooling effect of UGV. Specifically, we found increasing (artificial) rainfall and irrigation contribute to improving the cooling intensity of grassland in both climates, particularly in the hot-dry environment. The cities with high relative humidity would restrict the cooling effect of UGV. Increasing wind speed would significantly enhance the tree-covered while weakening the grass-covered UGVs' cooling effect in MC cities. We also identified that, in order to achieve the most effective cooling with the smallest sized tree-covered UGV, the area of trees in both climate zones' cities should generally be planned around 0.5 ha. The method and results enhance understanding of the cooling effect of UGVs on larger (climate) scales and provide important insights for UGV planning and management.

[A study of the relationship between MICA gene and systemic lupus erythematosus].

OBJECTIVE: To investigate the relationship between major histocompatibility complex class I chain-related A(MICA) gene and systemic lupus erythematosus (SLE). METHODS: The alleles and frequencies of exons 4 and 5 of MICA gene were determined in 70 cases of SLE and 152 controls of Yunnan Hans by STR genotyping, polymerase chain reaction, single strand conformation polymorphism and bidirection DNA sequencing. RESULTS: Five alleles of exon 5 and 10 alleles of exon 4 were found in this study. The frequency of each allele was determined in patients and controls. There was no significant difference between the two groups in exons 4 and 5 of MICA gene. CONCLUSION: Exons 4 and 5 of MICA were not related to SLE in Yunnan Hans.

[A simple and rapid methods used for silver staining and gel preservation].

This paper introduced the simple and rapid methods of silver staining and gel preservation. It was taken only about 10 and 15 minutes to stain a gel. The background of gel was light, the bands were clear, the sensibility was high and the stabilization was well by the method of silver staining. The gel preservation adopted a method named two-layer transparent plastic paper "Sandwich" which could keep the gel with primitive colors for a long time. The methods were used on PAG checking and SSCP typing of HLA and the results were satisfactory. The set of methods are expected to be widely used in laboratories.

[Polymorphism of HLA-DRB1 in Han population in Yunnan and comparison with 9 Han populations].

129 samples of Han population in Yunnan province were detected by polymerase chain reaction and microtitre plate hybridization (PCR-MPH). The samples of DR*15 subgroup being detected by PCR-MPH were further analyzed by Single-Strand Conformation Polymorphism (SSCP). By first polymerase chain reaction and microtitre plate hybridization (PCR-MPH), all of the 129 samples were divided into the following subgroups, viz. DR*01,DR*03,DR*04,DR*0701,DR*08,DR*09012,DR*1001,DR*11,DR*12,DR*13,DR*14,DR*15, DR*1602 and DR*1604. The samples of DR*04, DR*08/12, DR*03/11/13/14 were further detected by second PCR-MPH and the ones of DR*15 by SSCP. 36 kinds of alleles on HLA-DRB1 were detected in these samples. Among them, DRB1*1501(0.1240),DRB1*09012(0.0969), DRB1*08032(0.0930),DRB1*1202(0.0891),DRB1*1201(0.0814), DRB1 *1401(0.0775),DRB1 *0701(0.0620),are the most frequent. The chi(2) test of HLA-DRB1 alleles was done between Yunnan Han and the other 9 Han populations. In detail, comparing with Yunnan Han on the chi(2) test, the chi(2) values of few alleles in the few Han populations was more than 10, they were Xian Han(DR8,chi(2)=13.9712), Shanghai Han(DR4,chi(2)=10.1632), Guangdong Han(DR9,chi(2)=12.6121)and Nanjing Han(DR4,chi(2)=10.5796). Comparing with 9 Han populations, the genetic distance between Yunnan Han and Liaoning Han was the nearest(0.0541),Guangdong Han was the farthest(0.1851). In the 9 Han populations, the genetic distance between Shanghai Han and Nanjing Han was the nearest(0.0122),and the one between Tianjin Han and Shanxi Han was also nearer(0.0219). Based on above analysis, the conclusion may be deduced that the resource of Yunnan Han may be close to Liaoning Han and it was not a typical southern Han population though Yunnan Han are resident in the South. Some gene flow may be exit between Yunnan Han and the local minorities and made Yunnan Han become a special population.

A dominant-negative form of mouse SOX2 induces trophectoderm differentiation and progressive polyploidy in mouse embryonic stem cells.

SOX2 plays an important role in early embryogenesis by cooperating with OCT4 in regulating gene expression in fertilized eggs, yet the precise mechanism through which SOX2 accomplishes this important function remains poorly understood. Here, we describe the identification of two nuclear localization signals (NLS) in SOX2 and the generation of a dominant-negative mutant (Dmu-mSox2) by mutating these two NLS in its high mobility group domain. Characterization of this mutant demonstrated that SOX2 shuttles between the cytoplasm and nucleus using these two NLS. The mutant has lost its ability to interact with OCT4, but remains competent to interact with wild-type SOX2. Functionally, Dmu-mSox2 is inactive and unable to cooperate with OCT4 in transactivating target promoters bearing its binding sites. However, Dmu-mSox2 is able to inhibit the activity of wild-type SOX2 and subsequently suppress the activity of downstream genes such as Oct4 and Nanog. When stably expressed in embryonic stem (ES) cells, Dmu-mSox2 triggered progressive doublings of cell ploidy (>8N), leading to differentiation into the trophectoderm lineage. Knockdown of Sox2 by small interfering RNA also induced trophectoderm differentiation and polyploid formation in mouse ES cells. These results suggest that SOX2 maintains stem cell pluripotency by shuttling between the nucleus and cytoplasm in cooperation with OCT4 to prevent trophectoderm differentiation and polyploid formation in ES cells.

[Preliminary quantitative study of dynamic magnetic resonance diffusion tensor imaging in rabbit models implanted with hepatic tumor grafts from VX2].

OBJECTIVE: To investigate the feasibility of dynamic magnetic resonance diffusion tensor imaging (DTI) in rabbit models with implanted VX2 hepatic tumor grafts. METHODS: MRI and DTI images were obtained from 16 rabbit models with implanted VX2 hepatic tumor grafts (14, 18, 22, and 26 days after tumor implantation, respectively) and 4 normal rabbits. The average diffusion coefficient (ADC) and exponential ADC (eADC) were estimated and compared against pathological findings. RESULTS: The ADC values increased after tumor implantation but then decreased in the rabbit models, whereas eADC exhibited a pattern of reverse changes. These changes significantly differed from those in the control group. Coagulation necrosis and fibrous hyperplasia showed obvious increase as found by pathological examination. CONCLUSION: Dynamic MR DTI quantitative analysis of rabbit models of implanted VX2 hepatic tumor can partially describe the growth behaviors of implanted liver cancer.