Novel spatial profiles of some diffusive SIS epidemic models.

In this paper, we are concerned with two SIS epidemic reaction-diffusion models with mass action infection mechanism of the form SI, and study the spatial profile of population distribution as the movement rate of the infected individuals is restricted to be small. For the model with a constant total population number, our results show that the susceptible population always converges to a positive constant which is indeed the minimum of the associated risk function, and the infected population either concentrates at the isolated highest-risk points or aggregates only on the highest-risk intervals once the highest-risk locations contain at least one interval. In sharp contrast, for the model with a varying total population number which is caused by the recruitment of the susceptible individuals and death of the infected individuals, our results reveal that the susceptible population converges to a positive function which is non-constant unless the associated risk function is constant, and the infected population may concentrate only at some isolated highest-risk points, or aggregate at least in a neighborhood of the highest-risk locations or occupy the whole habitat, depending on the behavior of the associated risk function and even its smoothness at the highest-risk locations. Numerical simulations are performed to support and complement our theoretical findings.

Physicochemical characterizations of five Dioscorea alata L. starches from China.

D. alata is an important edible and medicinal plant in China. Its tuber is rich in starch but the understanding of the physiochemical properties of D. alata starch is limited. In order to explore the processing and application potential of different D. alata accessions in China, five kinds of D. alata starch (LY, WC, XT, GZ, SM) were isolated and characterized. The study showed that D. alata tubers contained abundant starch, enriched in amylose and resistant starch (RS). D. alata starches showed B-type or C-type diffraction pattern, had higher RS content and gelatinization temperature (GT), lower fa and viscosity when compared to D. opposita, D. esculenta, and D. nipponica. Among D. alata starches, D. alata (SM) showing the C-type diffraction pattern, had the lowest proportion of fa with 10.18 %, the highest amylose, RS2 and RS3 content of 40.24 %, 84.17 % and 10.48 % respectively, and the highest GT and viscosity. The results indicated that D. alata tubers are potential sources for novel starch with high amylose and RS content, and provided a theoretical basis for further utilizations of D. alata starch in food processing and industry application.

Population dynamics with resource-dependent dispersal: single- and two-species models.

In this paper, we consider the population models with resource-dependent dispersal for single-species and two-species with competition. For the single-species model, it is well-known that the total population supported by the environment is always greater than the environmental carrying capacity if the dispersal is simply random diffusion. However, we find that the total population supported can be equal or smaller than the environmental carrying capacity when the dispersal depends on the resource distribution. This analytical finding not only well agrees with the yeast experiment observation of Zhang et al. (Ecol Lett 20(9):1118-1128, 2017), but also indicates that resource-dependent dispersal may produce different outcomes compared to the random dispersal. For the two-species competition model, when two competing species use the same dispersal strategy up to a multiplicative constant (i.e. their dispersal strategies are proportional) or both diffusion coefficients are large, we give a classification of global dynamics. We also show, along with numerical simulations, that if the dispersal strategies are resource-dependent, even one species has slower diffusion, coexistence is possible though competitive exclusion may occur under different conditions. This is distinct from the prominent result that with random dispersal the slower diffuser always wipes out its fast competitor. Our analytical results, supported by the numerical simulations, show that the resource-dependent dispersal strategy has profound impact on the population dynamics and evolutionary processes.

Traveling wave solutions of a singular Keller-Segel system with logistic source.

This paper is concerned with the traveling wave solutions of a singular Keller-Segel system modeling chemotactic movement of biological species with logistic growth. We first show the existence of traveling wave solutions with zero chemical diffusion in $ \mathbb{R} $. We then show the existence of traveling wave solutions with small chemical diffusion by the geometric singular perturbation theory and establish the zero diffusion limit of traveling wave solutions. Furthermore, we show that the traveling wave solutions are linearly unstable in the Sobolev space $ H^1(\mathbb{R}) \times H^2(\mathbb{R}) $ by the spectral analysis. Finally we use numerical simulations to illustrate the stabilization of traveling wave profiles with fast decay initial data and numerically demonstrate the effect of system parameters on the wave propagation dynamics.

[Color characterization and its correlation with quality index during ripening of Rubus chingii].

The color of Rubus chingii was characterized by digital method, and the content of water extract, alcohol extract, total flavonoids, total polysaccharides, total polyphenols, ellagic acid, linden glycoside, kaophenol-3-O-rutin were determined. Correlation regression was used to analyze the correlation between color and composition. The results showed that L~* was positively correlated with total polyphenols, kaophenol-3-O-rutin and tilide, and moderately positively correlated with total flavones, ellagic acid and aqueous extracts. The a~* value was negatively correlated with total polyphenols, kaophenol-3-O-rutin, and linden glycosides, while was moderately correlated with total flavones, aqueous extracts, and ellagic acid. The b~* value was negatively correlated with the water extract, and moderately correlated with the content of total polyphenols, total polysaccharides, alcohol extract and kaophenol-3-O-rutin, which showed that R. chingii mature color had a significant correlation with material composition in the process of dynamic change. According to the law of dynamic change in the color and quality indexes, it is determined that the appropriate harvest time is in late April to May 1, while the fruit is not turn yellow. The agronomic traits related to fruit was(12.49±0.56) mm in diameter,(14.25±1.19)mm in height,(1.20±0.14) g in weight, the chroma L~* value was 52.87±3.14,a~* value was 2.01±1.58, b~* values was 28.31±3.88. The results lay a foundation for establishing an objective quantitative evaluation model of R. chingii color from experience.

Evaluation and application of an efficient plant DNA extraction protocol for laboratory and field testing.

Nucleic acids in plant tissue lysates can be captured quickly by a cellulose filter paper and prepared for amplification after a quick purification. In this study, a published filter paper strip method was modified by sticking the filter paper on a polyvinyl chloride resin (PVC) sheet. This modified method is named EZ-D, for EASY DNA extraction. Compared with the original cetyl trimethylammonium bromide (CTAB) method, DNA extracted by EZ-D is more efficient in polymerase chain reaction (PCR) amplification due to the more stable performance of the EZ-D stick. The EZ-D method is also faster, easier, and cheaper. PCR analyses showed that DNA extracted from several types of plant tissues by EZ-D was appropriate for specific identification of biological samples. A regular PCR reaction can detect the EZ-D-extracted DNA template at concentration as low as 0.1 ng/µL. Evaluation of the EZ-D showed that DNA extracts could be successfully amplified by PCR reaction for DNA fragments up to 3000 bp in length and up to 80% in GC content. EZ-D was successfully used for DNA extraction from a variety of plant species and plant tissues. Moreover, when EZ-D was combined with the loop-mediated isothermal amplification (LAMP) method, DNA identification of biological samples could be achieved without the need for specialized equipment. As an optimized DNA purification method, EZ-D shows great advantages in application and can be used widely in laboratories where equipment is limited and rapid results are required.

On the Lotka-Volterra competition system with dynamical resources and density-dependent diffusion.

In this paper, we consider the following Lotka-Volterra competition system with dynamical resources and density-dependent diffusion in a bounded smooth domain [Formula: see text] with homogeneous Neumann boundary conditions, where the parameters [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] ([Formula: see text]) are positive constants, m(x) is the prey's resource, and the dispersal rate function [Formula: see text] satisfies the the following hypothesis: [Formula: see text], [Formula: see text] on [Formula: see text] and [Formula: see text]. When m(x) is constant, we show that the system (*) with has a unique global classical solution when the initial datum is in functional space [Formula: see text] with [Formula: see text]. By constructing appropriate Lyapunov functionals and using LaSalle's invariant principle, we further prove that the solution of (*) converges to the co-existence steady state exponentially or competitive exclusion steady state algebraically as time tends to infinity in different parameter regimes. Our results reveal that once the resource w has temporal dynamics, two competitors may coexist in the case of weak competition regardless of their dispersal rates and initial values no matter whether there is explicit dependence in dispersal or not. When the prey's resource is spatially heterogeneous (i.e. m(x) is non-constant), we use numerical simulations to demonstrate that the striking phenomenon "slower diffuser always prevails" (cf. Dockery et al. in J Math Biol 37(1):61-83, 1998; Lou in J Differ Equ 223(2):400-426, 2006) fails to appear if the non-random dispersal strategy is employed by competing species (i.e. either [Formula: see text] or [Formula: see text] is non-constant) while it still holds true if both d(w) and [Formula: see text] are constant.

Selective hydrosilylation of allyl chloride with trichlorosilane.

The transition-metal-catalysed hydrosilylation reaction of alkenes is one of the most important catalytic reactions in the silicon industry. In this field, intensive studies have been thus far performed in the development of base-metal catalysts due to increased emphasis on environmental sustainability. However, one big drawback remains to be overcome in this field: the limited functional group compatibility of the currently available Pt hydrosilylation catalysts in the silicon industry. This is a serious issue in the production of trichloro(3-chloropropyl)silane, which is industrially synthesized on the order of several thousand tons per year as a key intermediate to access various silane coupling agents. In the present study, an efficient hydrosilylation reaction of allyl chloride with trichlorosilane is achieved using the Rh(I) catalyst [RhCl(dppbzF)]2 (dppbzF = 1,2-bis(diphenylphosphino)-3,4,5,6-tetrafluorobenzene) to selectively form trichloro(3-chloropropyl)silane. The catalyst enables drastically improved efficiency (turnover number, TON, 140,000) and selectivity (>99%) to be achieved compared to conventional Pt catalysts.

[Effects of different application amounts of potassium fulvic acid on yield and quality of Fritillaria thunbergii].

Fritillaria thunbergii is a commonly used traditional Chinese medicine, which has the effects of clearing heat and resolving stagnation, eliminating phlegm and relieving cough. At present, it is mostly produced by cultivation, and the cultivation process requires application of base fertilizer, winter fertilizer, seedling fertilizer and late top dressing. Now farmyard manure or organic fertilizer can be used to replace the base fertilizer and winter fertilizer, but the research on the replacement of organic fertilizer has not been completed for the late top dressing. Potassium fulvate is a kind of fulvate fertilizer, which can not only regulate the growth of crops but also supplement potassium necessary for the growth of crops. In this paper, using F. thunbergii as a model plant with mature cultivation techniques, the effect of potassium fulvate on the quality and yield of rhizome traditional Chinese medicine F. thunbergii was systematically studied for the first time. HPLC-ELSD was used to determine the contents of peimine A and peimine B, hot dip method was used to determine the content of alcohol extract, and the SPAD-502 Plus chlorophyll meter was used to detect SPAD value. The results showed that applying 1.5 to 2.25 kg·hm~(-2) of potassium fulvic acid per hectare could effectively improve the yield of F. thunbergii and there was significantly difference between potassium phosphate monobasic and potassium fulvic acid in terms of quality. After the application of range 1.5 to 2.25 kg·hm~(-2) of potassium fulvic acid per hectare, the content of alcohol soluble extract of F. thunbergii was ranged 21.61% to 22.27%, the total amount of peimine A and peimine B were ranged 0.09% to 0.10%. Applying 1.5 to 2.25 kg·hm~(-2) of potassium fulvic acid per hectare could replace the conventional pure chemical fertilizer potassium phosphate monobasic, which could be used as top dressing fertilizer for the cultivation of F. thunbergii.

Phosphorus and oxygen co-doped composite electrode with hierarchical electronic and ionic mixed conducting networks for vanadium redox flow batteries.

The hierarchical electronic and ionic mixed conducting networks build in graphite felt electrodes possess excellent electrocatalytic activity and faster electronic and ionic conduction, resulting in an enhanced energy efficiency of vanadium redox flow batteries with durable life for 1000 cycles and a high discharge capacity of 10.1 A h L-1 at a current density of 350 mA cm-2.

[Breeding and variety characteristics of a new variety of Fritillaria thunbergii "Zhebei 3"].

A new variety "Zhebei 3(Zhejiao Pharmaceutical 2018002)" was selected and bred from multi seeded Fritillaria thunbergii mutants by systematic breeding method. From 2012 to 2016, the traits assessment, disease resistance appraisal, plot ratios and regional trials of the variety were continuously carried out. The results showed that "Zhebei 3" emerged early and had late seedlings. The average growth period was about 100 days, which was 6 days and 12 days higher than the "Zhebei 1" and "Zhebei 2". The average yield was 5 095.5 kg·hm~(-2), which was 14.42% and 17.71% higher than of the control respectively. The average proliferation rate of bulbs was 261.2%, which was 37.46% and 31.58% higher than that of the control, respectively. The propagation coefficient of bulbs was about 1∶2.6, and the total amount of peimine and peiminine was 0.172 2%, which was 4.49% and 29.47% higher than the control, respectively. The identification of disease resistance showed that it was resistance to bulb stem(soft) rot, better than the control. "Zhebei 3" has stable characters, high yield, good quality, strong disease resistance, and moderate propagation coefficient which is suitable for planting in Zhejiang province.

[Correlation analysis between quality and habitat phenotype of Hovenia acerba].

The contents of dihydromyricetin and total flavonoids of Hovenia acerba seeds were detected by HPLC-DAD and UV spectrophotometer. And then the correlation between the habitat, phenotype and quality of H. acerba seeds were deeply studied. There were big differences in both appearance and quality among the H. acerba seeds from different places. It showed that the content of dihydromyricetin in H. acerba seeds was 0.41-9.81 mg•g⁻¹, and the content of total flavonoids was 5.52-21.98 mg•g⁻¹. The cluster analysis showed that the quality of H. acerba seeds was related to the habitat. The samples from Jianghan Plain Area showed relatively stable and excellent quality. According to the correlation analysis, there was a significant positive correlation between 1 000-seeds weight, red-black seeds ratio and the content of dihydromyricetin, while the content of total flavonoids was not related to the 1 000-seeds weight and red-black seeds ratio. So the 1 000-seeds weight and red-black seeds ratio could be used as an initial judgment of the quality of H. acerba seeds. As dihydromyricetin and total flavonoids content was not related, both dihydromyricetin and total flavonoids should be taken into account when the quality of H. acerba seeds was studied.

Isaria cicadae conidia possess antiproliferative and inducing apoptosis properties in gynaecological carcinoma cells.

Isaria cicadae is an entomogenous fungus that has been used as a traditional Chinese medicinal materials to treat different diseases, including cancer. However, Isaria cicadae conidia for inhibitory activity against breast cancer cells growth are still not systematically studied. The present aim was to elucidate the phytochemical composition of Isaria cicadae conidia and to explore relevant anti-cancer potential in gynaecological carcinoma MCF-7 and Hela cells. Isaria cicadae conidia were identified by UPLC-ESI-Q-TOF-MS: high performance liquid chromatography-electrospray/quadrupole time of flight tandem mass spectrometry technology. Eight main compounds were identified which are nucleosides, cordycepic acid, cordycepin, beauvericin and myriocin by MS fragmentation ions. The nuclear morphology indicated the typical characteristics of apoptosis by Hoechst staining. Annexin V/PI staining revealed that the number of apoptotic cells was increased by Isaria cicadae conidia treatment. Furthermore, Isaria cicadae conidia also induced the caspase-mediated mitochondrial apoptosis pathway. The findings suggest that the full-scale active ingredients highlight the significance of Isaria cicadae conidia as potential anti-cancer agent in China.

Development of SSR Markers and Assessment of Genetic Diversity in Medicinal Chrysanthemum morifolium Cultivars.

Chrysanthemum morifolium, is a well-known flowering plant worldwide, and has a high commercial, floricultural, and medicinal value. In this study, simple-sequence repeat (SSR) markers were generated from EST datasets and were applied to assess the genetic diversity among 32 cultivars. A total of 218 in silico SSR loci were identified from 7300 C. morifolium ESTs retrieved from GenBank. Of all SSR loci, 61.47% of them (134) were hexa-nucleotide repeats, followed by tri-nucleotide repeats (17.89%), di-nucleotide repeats (12.39%), tetra-nucleotide repeats (4.13%), and penta-nucleotide repeats (4.13%). In this study, 17 novel EST-SSR markers were verified. Along with 38 SSR markers reported previously, 55 C. morifolium SSR markers were selected for further genetic diversity analysis. PCR amplification of these EST-SSRs produced 1319 fragments, 1306 of which showed polymorphism. The average polymorphism information content of the SSR primer pairs was 0.972 (0.938-0.993), which showed high genetic diversity among C. morifolium cultivars. Based on SSR markers, 32 C. morifolium cultivars were separated into two main groups by partitioning of the clusters using the unweighted pair group method with arithmetic mean dendrogram, which was further supported by a principal coordinate analysis plot. Phylogenetic relationship among C. morifolium cultivars as revealed by SSR markers was highly consistent with the classification of medicinal C. morifolium populations according to their origin and ecological distribution. Our results demonstrated that SSR markers were highly reproducible and informative, and could be used to evaluate genetic diversity and relationships among medicinal C. morifolium cultivars.

Development of selectable marker-free transgenic potato plants expressing cry3A against the Colorado potato beetle (Leptinotarsa decemlineata Say).

BACKGROUND: Elimination of selectable marker genes (SMGs) is important for the safe assessment and commercial use of transgenic plants. The destructive and invasive Colorado potato beetle (CPB) poses a serious threat to potato production. In response to this need, selectable marker-free transgenic potato lines expressing cry3A were developed to control the damage and spread of CPB. RESULTS: We simultaneously introduced cry3A and npt II genes harboured in different plasmids into the potato genome using the Agrobacterium-mediated cotransformation method. Four selectable marker-free transgenic potato (CT) lines expressing cry3A were developed by self-crossing segregation and molecular analyses, including Southern blot, western blot and enzyme-linked immunosorbent assay (ELISA) assays. CT lines were used in a resistance bioassay against CPB in the laboratory and field. In the laboratory, CT lines exhibited high resistance to CPB, and 100% mortality of first-instar larvae occurred 6 days after infestation. In the field, untransformed plant leaves were almost entirely consumed, with an average of 155 larvae present per plant 25 days after inoculation. However, CT lines showed no damage symptoms, with approximately 2.5 larvae surviving per plant. CONCLUSION: We successfully eliminated SMGs from the transgenic potato lines expressing cry3A in order to decrease CPB damage, control the spread of this pest eastwards and alleviate the concern regarding the safe assessment of regulatory requirements. © 2015 Society of Chemical Industry.

The mitochondrial malate dehydrogenase 1 gene GhmMDH1 is involved in plant and root growth under phosphorus deficiency conditions in cotton.

Cotton, an important commercial crop, is cultivated for its natural fibers, and requires an adequate supply of soil nutrients, including phosphorus, for its growth. Soil phosporus exists primarily in insoluble forms. We isolated a mitochondrial malate dehydrogenase (MDH) gene, designated as GhmMDH1, from Gossypium hirsutum L. to assess its effect in enhancing P availability and absorption. An enzyme kinetic assay showed that the recombinant GhmMDH1 possesses the capacity to catalyze the interconversion of oxaloacetate and malate. The malate contents in the roots, leaves and root exudates was significantly higher in GhmMDH1-overexpressing plants and lower in knockdown plants compared with the wild-type control. Knockdown of GhmMDH1 gene resulted in increased respiration rate and reduced biomass whilst overexpression of GhmMDH1 gave rise to decreased respiration rate and higher biomass in the transgenic plants. When cultured in medium containing only insoluble phosphorus, Al-phosphorus, Fe-phosphorus, or Ca-phosphorus, GhmMDH1-overexpressing plants produced significantly longer roots and had a higher biomass and P content than WT plants, however, knockdown plants showed the opposite results for these traits. Collectively, our results show that GhmMDH1 is involved in plant and root growth under phosphorus deficiency conditions in cotton, owing to its functions in leaf respiration and P acquisition.

[Study on combined effects of chemical components for different flowers blossoming degree of yellow medicinal Chrysanthemum morifolium from Zhejiang].

The ingredients of five kinds of Zhejiang's yellow Chrysanthemum morifolium with different flower blossoming stages were comparatively analyzed. Polysaccharides, total flavonoids, volatile oil, alcohol extract, water extract, chlorogenic acid, luteolin, 3,5-O-dicaffeoyl quinic acid and fingerprint of the ingredient were determined as indicators. During flower blossoming stages, the ingredients of Ch. morifolium showed a big difference with a certain variation. At the early opening stage, the contents of flavonoids and volatile oil were higher, the content of chlorogenic acid, luteolin, 3,5-O-dicaffeoyl quinic acid were higher in the middle of the flowers 50% -80% fowers blossoming degree is the optimal time for harvest.

[Study on method of paeonia radix alba producing and concocting integration processing].

OBJECTIVE: To study the origin pre-treating and processing integration techniques of Paeonia Radix Alba. METHOD: Different processing integration techniques were adopted and compared with traditional processing techniques to determine drying rate, aqueous extracts and peoniflori content. RESULT: Half-dry slices baked at 100 degrees C for 20 min and steamed at 100 degrees C for 10 min had the highest peoniflori contents. Half-dry slices baked at 100 degrees C for 20 min had the highest content of aqueous extracts. Products processed with conventional method and sulfur-fumigation had the lowest content of aqueous extracts. CONCLUSION: The origin processing integration techniques of Paeonia Radix Alba lose less active ingredients than conventional processing methods.

Influence of ribosomal protein L39-L in the drug resistance mechanisms of lacrimal gland adenoid cystic carcinoma cells.

BACKGROUND: Cancer constitutes a key pressure on public health regardless of the economy state in different countries. As a kind of highly malignant epithelial tumor, lacrimal gland adenoid cystic carcinoma can occur in any part of the body, such as salivary gland, submandibular gland, trachea, lung, breast, skin and lacrimal gland. Chemotherapy is one of the key treatment techniques, but drug resistance, especially MDR, seriously blunts its effects. As an element of the 60S large ribosomal subunit, the ribosomal protein L39-L gene appears to be documented specifically in the human testis and many human cancer samples of different origins. MATERIALS AND METHODS: Total RNA of cultured drug-resistant and susceptible lacrimal gland adenoid cystic carcinoma cells was seperated, and real time quantitative RT-PCR were used to reveal transcription differences between amycin resistant and susceptible strains of lacrimal gland adenoid cystic carcinoma cells. Viability assays were used to present the amycin resistance difference in a RPL39-L transfected lacrimal gland adenoid cystic carcinoma cell line as compared to control vector and null-transfected lacrimal gland adenoid cystic carcinoma cell lines. RESULTS: The ribosomal protein L39-L transcription level was 6.5-fold higher in the drug-resistant human lacrimal gland adenoid cystic carcinoma cell line than in the susceptible cell line by quantitative RT-PCR analysis. The ribosomal protein L39-L transfected cells revealed enhanced drug resistance compared to plasmid vector-transfected or null-transfected cells as determined by methyl tritiated thymidine (3H-TdR) incorporation. CONCLUSIONS: The ribosomal protein L39-L gene could possibly have influence on the drug resistance mechanism of lacrimal gland adenoid cystic carcinoma cells.

Classical solutions and steady states of an attraction-repulsion chemotaxis in one dimension.

We establish the existence of global classical solutions and non-trivial steady states of a one-dimensional attraction-repulsion chemotaxis model subject to the Neumann boundary conditions. The results are derived based on the method of energy estimates and the phase plane analysis.