[Effect of combined application of inorganic and organic fertilizers on growth and quality of Salvia miltiorrhiza]

The study is aimed through field experiments to study the effect of combined application of organic and chemical fertilizers on the growth and quality of Salvia miltiorrhiza, provide ideas for reducing fertilization while increasing the efficiency as well as improving the quality of produces. The experiment included 6 treatments viz., no fertilization(CK), full application of chemical fertilizer(F), 25% orga-nic fertilizer with 75% chemical fertilizer(M25), 50% organic fertilizer with 50% chemical fertilizer(M50), 75% organic fertilizer with 25% chemical fertilizer(M75), and fully apply organic fertilizer(M100). The results showed that:(1)from the perspective of yield and economic benefits, M75 was the best and M100 second;(2)for effective components, the combined application of organic and chemical fertilizers increased the content of main water-soluble components and the total content of effective components, among which M25 and M50 were better.

A Bis(Salamo)-Based Fluorogenic Sensor for Highly Selective and Sequential Recognition of Cu2+ and B4O72- Ions in Semi-Aqueous Medium

A new type of multifunctional bis(salamo)-based fluorogenic sensor H₂BS was designed and synthesized. Under the action of V_DMF: V_H2O = 9: 1, the fluorogenic sensor can identify Cu²⁺ and B₄O₇^2-, in which N and O atoms can serve as binding sites for Cu²⁺ and B₄O₇^2-, the stoichiometry of the binding of the fluorogenic sensor H₂BS and Cu²⁺ has been confirmed by titration experiment, working curve, ESI-MS analysis and DFT calculation. The pH response experiment also confirmed that the fluorogenic sensor can recognize Cu²⁺ and B₄O₇^2- in the pH range applicable to the physiological environment. The minimum detection limit of H₂BS for Cu²⁺ and B₄O₇^2- recognition reaches 1.12 × 10^-7 and 5.56 × 10^-8 M, and the fluorogenic sensor H₂BS has been successfully applied to Cu²⁺ detection in actual water samples, and the test strip for detecting Cu²⁺ and B₄O₇^2- was obtained. Meanwhile, the success of the test strip experiment made the fluorogenic sensor H₂BS to recognize Cu²⁺ and B₄O₇^2- widely used in daily life. A new type of salamo-based multifunctional fluorogenic sensor H₂BS was designed and synthesized to identify Cu²⁺ and B₄O₇^2- in aqueous solvent systems. Added Cu²⁺ to H₂BS can cause fluorescence quenching. Further experiments showed that H₂BS and Cu²⁺ form a stable 1:2 complex, while B₄O₇^2- can also cause fluorescence quenching of H₂BS, which is the occurrence of the PET effect. Meanwhile, H₂BS can be used for quantitative detection in the environment and rapid identification in life.

Higher plasticity in feeding preference of a generalist than a specialist: experiments with two closely related Helicoverpa species

Herbivorous insects have been categorized as generalists or specialists depending on the taxonomic relatedness of the plants they use as food or oviposition substrates. The plasticity in host plant selection behavior of species belonging to the two categories received little attention. In the present work, fifth instar caterpillars of the generalist herbivore Helicoverpa armigera and its closely related species, the specialist Helicoverpa assulta, were fed on common host plants or artificial diet, after which their feeding preference was assessed individually by using dual - and triple- plant choice assays. Results show both the two Helicoverpa species have a preference hierarchy for host plants. Compared to the fixed preference hierarchy of the specialist H. assulta, the generalist H. armigera exhibited extensive plasticity in feeding preference depending on the host plant experienced during larval development. Whereas the specialist H. assulta exhibited a rigid preference in both dual and triple-plant choice assays, our findings demonstrate that the generalist H. armigera expressed stronger preferences in the dual-plant choice assay than in the triple-plant choice assay. Our results provide additional evidence supporting the neural constraints hypothesis which predicts that generalist herbivores make less accurate decisions than specialists when selecting plants.

A saxitoxin-binding aptamer with higher affinity and inhibitory activity optimized by rational site-directed mutagenesis and truncation

Saxitoxin (STX), a member of the family of paralytic shellfish poisoning toxins, poses toxicological and ecotoxicological risks. To develop an analytical recognition element for STX, a DNA aptamer (APT(STX1)) was previously discovered via an iterative process known as Systematic Evolution of Ligands by Exponential Enrichment (SELEX) by Handy et al. Our study focused on generating an improved aptamer based on APT(STX1) through rational site-directed mutation and truncation. In this study, we generated the aptamer, M-30f, with a 30-fold higher affinity for STX compared with APT(STX1). The Kd value for M-30f was 133 nM, which was calculated by Bio-Layer Interferometry. After optimization, we detected and compared the interaction of STX with aptamers (APT(STX1) or M-30f) through several techniques (ELISA, cell bioassay, and mouse bioassay). Both aptamers' STX-binding ability was demonstrated in all three methods. Moreover, M-30f performs better than its parent sequence with higher suppressive activity against STX. As a molecular recognition element, M-30f has good prospects for practical application.

Fitness traits and underlying genetic variation related to host plant specialization in the aphid Sitobion avenae

Sitobion avenae (F.) is an important cereal pest worldwide that can survive on various plants in the Poaceae, but divergent selection on different host plants should promote the evolution of specialized genotypes or host races. In order to evaluate their resource use strategies, clones of S. avenae were collected from oat and barley. Host-transfer experiments for these clones were conducted in the laboratory to compare their fitness traits. Our results demonstrated that barley clones had significantly lower fecundity and tended to have longer developmental times when transferred from barley to oat. However, oat clones developed faster after they were transferred to barley. Clones from oat and barley had diverged to a certain extent in terms of fecundity and developmental time of the nymphs. The separation of barley clones and oat clones of S. avenae was also evident in a principal component analysis. Barley clones tended to have higher broad-sense heritabilities for fitness traits than oat clones, indicating the genetic basis of differentiation between them. Barley clones showed significantly higher extent of specialization compared to oat clones from two measures of specialization (i.e., Xsp and Ysp). Therefore, barley clones were specialized to a certain extent, but oat clones appeared to be generalized. The fitness of S. avenae clones tended to increase with higher extent of specialization. The evolution toward ecological specialization in S. avenae clones, as well as the underlying genetic basis, was discussed.

4-({4-[1-(Methoxy-imino)eth-yl]anilino}(phen-yl)methyl-ene)-3-methyl-2-phenyl-1H-pyrazol-5(4H)-one

In the title compound, C₂₆H₂₄N₄O₂, the dihedral angles between the central pyrazole ring and the other three benzene rings are 40.02 (3), 77.51 (5) and 55.72 (3)°. A strong intra­molecular N—H⋯O hydrogen bond forms a six-membered ring with an S(6) motif. In the crystal structure, a weak inter­molecular C—H⋯N inter­action with graph-set motif R₂²(8) and C—H⋯O hydrogen bonds link each mol­ecule to three others, forming an infinite two-dimensional supra­molecular structure.

(E)-2-{4-[1-(Hydroxyimino)ethyl]phenyliminomethyl}-6-methoxyphenol monohydrate

In the title compound, C₁₆H₁₆N₂O₃·H₂O, the benzene rings are nearly coplanar with each other, forming a dihedral angle of 4.46 (3)°. There is a strong intra­molecular O—H⋯N hydrogen bond which results in a six-membered ring. In the crystal, the mol­ecules are connected into a three-dimensional network via O—H⋯O and O—H⋯N inter­molecular hydrogen bonds, forming a centrosymmetric ring along the b axis with graph-set motif R₄⁴(10). In addition, the short distances between the centroids of six-membered rings [3.555 (1) Å], indicate the existence of π–π stacking inter­actions, which may stabilize the crystal structure.

5,5′-Dimethoxy-2,2′-[(nonane-1,9-diyldioxy)bis(nitrilomethylidyne)]diphenol

The mol­ecule of the title compound, C₂₅H₃₄N₂O₆, adopts a fully extended configuration. The oxime (—CH=N—O—) group is coplanar with the aromatic ring and the two benzene rings are almost parallel, making a dihedral angle of 0.16 (3)°. In the crystal structure, strong intra­molecular O—H⋯N hydrogen bonds generate six-membered S(6) ring motifs. Inter­molecular C—H⋯O hydrogen bonds link each mol­ecule to five others, forming an infinite three-dimensional supra­molecular structure. The crystal is further stabilized by π–π stacking inter­actions between neighbouring benzene rings [centroid–centroid distance = 3.744 (2) Å].

1,3-Bis[(4-methylbenzylidene)amino-oxy]propane

The title bis­oxime compound, C₁₉H₂₂N₂O₂, synthesized by the reaction of 4-methyl-2-hydroxy­benzaldehyde with 1,3-bis­(amino­oxy)propane in ethanol, adopts a V-shaped conformation. The dihedral angle between the rings is 84.59 (3)°. The mol­ecule is disposed about a crystallographic twofold rotation axis, with one C atom lying on the axis. In the crystal, mol­ecules are packed by C—H⋯π(Ph) inter­actions, forming chains.

{4,4'-Dimeth-oxy-2,2'-[ethyl-enedioxy-bis(nitrilo-methyl-idyne)]diphenolato}copper(II)

The title complex, [Cu(C(18)H(18)N(2)O(6))], was synthesized by the reaction of copper(II) acetate mono-hydrate with the ligand 4,4'-dimeth-oxy-2,2'-[ethyl-enedioxy-bis(nitrilo-methyl-idyne)]diphenol (H(2)L). The Cu atom is coordinated by two O atoms and two N atoms of the L(2-) unit. A bridged dimer is formed through inter-molecular Cu⋯O inter-actions [Cu⋯O = 1.9408 (15) Å], creating a distorted square-pyramidal geometry about the Cu atoms.

Radon measurements in underground dwellings from two prefectures in China

Radon, an established lung carcinogen, remains the single most important environmental radiation exposure. Yet, an excess of lung cancer from breathing radon in homes has not been consistently demonstrated in studies conducted to date. To address several major problems that have hindered previous studies of lung cancer and radon in homes, we have embarked upon a lung cancer case-control study in Gansu Province, China, where a substantial proportion of the population live in underground dwellings. In this paper, we report on results of a pilot study in which radon measurements were made for 3 days in the summer in 40 homes under normal occupancy conditions using short-term E-PERM detectors and for 6 months from February through August in 49 homes using long-term alpha-track detectors. Useable E-PERM data were obtained from 38 homes and useable alpha-track data from 47 homes. For both types of detectors, measurements were approximately log-normally distributed. Arithmetic and geometric means were 233 and 185 Bq m-3 (range 74-1,590 Bq m-3) for E-PERM measurements and 165 and 158 Bq m-3 (range 74-592 Bq m-3) for alpha-track measurements, respectively; 68% of E-PERM measured homes and 55% of alpha-track measured homes exceeded 148 Bq m-3. Alpha-track measurements made at the entry, middle, and rear areas of the underground dwellings did not differ significantly (arithmetic means of 168, 162, and 165 Bq m-3 with standard deviations 63, 73, and 48, respectively), which suggests that air circulation may be minimal. The underground dwellings measured in the pilot study had high radon levels and the underground dwellers may provide an excellent population for studying indoor radon and risk of lung cancer.

Biochemical and enzymological study of lactate dehydrogenase isoenzymes from commercial quality control sera and several animal tissue sources

We assayed the isoenzymes of lactate dehydrogenase (EC 1.1.1.27) in commercial quality control sea and several animal tissue extracts, using electrophoresis. We compared the Km values and activation energies of the isoenzymes, in order to find suitable animal tissue sources with a similar isoenzyme profile to that of human serum lactate dehydrogenase. Some of the control sera contained only one isoenzyme fraction corresponding to porcine heart isoenzyme-1 or chicken heart isoenzyme-1, which showed essentially no changes of enzyme activity as a function of pyruvate substrate concentration. Other control sera, which contained isoenzymes from human red cells haemolysates, or from animal tissue extracts with a human serum matrix, showed significant changes of enzyme activity was a function of substrate concentration, and showed different Km values and activation energies from those of human serum. Of the serum and tissue samples from several animal sources, rat heart and kidney extracts showed the greatest similarity to human serum, with respect to the electrophoretic pattern and the Km, pH optimum and activation energy of lactate dehydrogenase isoenzymes.