Auxin homeostasis is maintained by sly-miR167-SlARF8A/B-SlGH3.4 feedback module in the development of locular and placental tissues of tomato fruits.

The locular gel, produced by the placenta, is important for fruit flavor and seed development in tomato. However, the mechanism underlying locule and placenta development is not fully understood yet. Here, we show that two SlARF transcription factors, SlARF8B and SlARF8A (SlARF8A/B), promote the development of locular and placenta tissues. The expression of both SlARF8A and SlARF8B is repressed by sly-microRNA167 (sly-miR167), allowing for the activation of auxin downstream genes. In slarf8a, slarf8b, and slarf8a/b mutants, the auxin (IAA) levels are decreased, whereas the levels of inactive IAA conjugates including IAA-Ala, IAA-Asp, and IAA-Glu are increased. We further find that SlARF8B directly inhibits the expression of SlGH3.4, an acyl acid amino synthetase that conjugates the amino acids to IAA. Disruption of such auxin balance by the increased expression of SlGH3.4 or SlGH3.2 results in defective locular and placental tissues. Taken together, our findings reveal an important regulatory module constituted by sly-miR167-SlARF8A/B-SlGH3.4 during the development of locular and placenta tissues of tomato fruits.

Constructing asymmetric double-atomic sites for synergistic catalysis of electrochemical CO2 reduction.

Elucidating the synergistic catalytic mechanism between multiple active centers is of great significance for heterogeneous catalysis; however, finding the corresponding experimental evidence remains challenging owing to the complexity of catalyst structures and interface environment. Here we construct an asymmetric TeN2-CuN3 double-atomic site catalyst, which is analyzed via full-range synchrotron pair distribution function. In electrochemical CO2 reduction, the catalyst features a synergistic mechanism with the double-atomic site activating two key molecules: operando spectroscopy confirms that the Te center activates CO2, and the Cu center helps to dissociate H2O. The experimental and theoretical results reveal that the TeN2-CuN3 could cooperatively lower the energy barriers for the rate-determining step, promoting proton transfer kinetics. Therefore, the TeN2-CuN3 displays a broad potential range with high CO selectivity, improved kinetics and good stability. This work presents synthesis and characterization strategies for double-atomic site catalysts, and experimentally unveils the underpinning mechanism of synergistic catalysis.

A HD-ZIP transcription factor specifies fates of multicellular trichomes via dosage-dependent mechanisms in tomato.

Hair-like structures are shared by most living organisms. The hairs on plant surfaces, commonly referred to as trichomes, form diverse types to sense and protect against various stresses. However, it is unclear how trichomes differentiate into highly variable forms. Here, we show that a homeodomain leucine zipper (HD-ZIP) transcription factor named Woolly controls the fates of distinct trichomes in tomato via a dosage-dependent mechanism. The autocatalytic reinforcement of Woolly is counteracted by an autoregulatory negative feedback loop, creating a circuit with a high or low Woolly level. This biases the transcriptional activation of separate antagonistic cascades that lead to different trichome types. Our results identify the developmental switch of trichome formation and provide mechanistic insights into the progressive fate specification in plants, as well as a path to enhancing plant stress resistance and the production of beneficial chemicals.

Clinical efficacy and safety of comprehensive nursing intervention in acute leukemia patients with myelosuppression after chemotherapy.

OBJECTIVE: To investigate the clinical efficacy and safety of comprehensive nursing intervention in acute leukemia patients with myelosuppression after chemotherapy. METHODS: Eighty acute leukemia patients with myelosuppression after chemotherapy admitted to our hospital from April 2018 to December 2021 were selected and divided, according to the nursing mode, as the conventional group (n=40) with routine nursing mode and the comprehensive group (n=40) with the comprehensive nursing mode. Patients' anxiety (Self-Rating Anxiety Scale, SAS) scores, depression (Self-Rating Depression Scale, SDS) scores, occurrence of complications, nursing satisfaction, nursing experience, complaint rate, and Visual Analogue Scale (VAS) score were compared between the two groups so as to analyze the efficacy and safety of comprehensive nursing intervention. The improvement of quality of life in the two groups was observed and analyzed using the short form of quality of life measurement (WHOQOL-BREF). Logistic regression analysis was performed to analyze the risk factors for nosocomial infection in patients with comprehensive nursing intervention. RESULTS: No statistically significant differences in SAS and SDS scores between the two groups were found prior nursing (P>0.05), while after nursing, scores in the two groups both decreased, with those in the comprehensive group significantly lower than in the conventional group (P<0.05). The incidence of complications after nursing in the comprehensive group was significantly lower than that in the conventional group, and the difference was statistically significant (P<0.05). Nursing satisfaction of patients in the comprehensive group were significantly higher than that in the conventional group (P<0.05). After nursing, the nursing experience of the comprehensive group was significantly better than that of the conventional group (P<0.05); the complaint rate of the comprehensive group was significantly lower than that of the conventional group (P<0.05); before nursing, there was no significant difference in the VAS scores between the two groups of patients (P>0.05); after nursing, the VAS score of the comprehensive group was significantly lower than that of the conventional group (P<0.05). Before nursing, there was no significant difference in WHOQOL-BREF scores between the two groups (P>0.05); after nursing, the comprehensive group was higher than the conventional group. Among the 40 patients in the comprehensive nursing group, 15 patients developed infection. The number of neutrophils, age above 40, white blood cell count, hemoglobin content, high-intensity chemotherapy and glucocorticoid therapy were independent risk factors for nosocomial infection in patients with comprehensive nursing intervention (P<0.05). CONCLUSION: Comprehensive nursing intervention for patients with myelosuppression after chemotherapy for acute leukemia can effectively improve the patient's nursing experience, reduce the patient's complaint rate, alleviate the patient's physical pain, relieve the patient's anxiety, depression and other negative emotions, and reduce the patient's complications, suggesting that comprehensive nursing intervention exerts better clinical efficacy and has high safety, which merits promotion clinically.

H and HL synergistically regulate jasmonate-triggered trichome formation in tomato.

The development of trichomes, which protect plants against herbivores, is affected by various stresses. In tomato, previous studies showed that stress triggered JA signaling influences trichome formation, but the underlying mechanism is not fully resolved. Here, we found two C2H2 zinc finger proteins synergistically regulate JA-induced trichome formation in tomato. The naturally occurring mutations in H and its close homolog H-like gene in a spontaneous mutant, LA3172 cause severely affected trcihome development. Compared with respective single mutant, h/hl double mutant displayed more severe trichome defects in all tissues. Despite the partially redundant function, H and HL genes regulate the trichome formation in the spatially distinct manner, with HL more involved in hypocotyls and leaves, while H more involved in stems and sepals. Furthermore，the activity of H/HL is essential for JA-triggered trichome formation. JA signaling inhibitor SlJAZ2 represses the activity of H and HL via physical interaction, resulting in the activation of THM1, a negative regulator of trichome formation. Our results provide novel insight into the mechanism of the trichome formation in response to stress induced JA signaling in tomato.

Hollow MnFe2O4@C@APBA Nanospheres with Size Exclusion and pH Response for Efficient Enrichment of Endogenous Glycopeptides.

Enrichment and detection of glycopeptides are an important clinical measure for the diagnosis of complex diseases. Enrichment materials play a key role in this process; they must have an effective sample-screening ability to eliminate the interference of nonglycopeptides. In this work, novel hollow MnFe2O4@C@APBA nanospheres (HMCAs) with magnetic and pH responsiveness were prepared for glycopeptide enrichment. The as-prepared composites have a suitable hollow structure and large specific surface area, and the boron hydroxyl group in their cavities can fix or disconnect the hydrophilic groups of the glycopeptides at different pH, so the glycopeptides can be adsorbed or desorbed in a controllable way. Enrichment results showed that the HMCAs exhibited an excellent enrichment performance: ultralow limit of detection (approximately 0.5 fmol µL-1), perfect size-exclusion effect (HRP/BSA, 1:800, w/w), favorable universality (HRP, IgG, and RNase B), and high binding capacity (150 mg/g). In order to verify the application of materials in practice, the HMCAs were used for the analysis of complex samples and it was found that 474 glycopeptides were identified from 210 glycoproteins in three replicate analyses of 2 µL of human serum. The results showed that the HMCAs could be used as a promising enrichment material for glycopeptide characterization in MS-based glycoproteomics and related fields.

HOMEODOMAIN PROTEIN8 mediates jasmonate-triggered trichome elongation in tomato.

Plant hormones can adjust the physiology and development of plants to enhance their adaptation to biotic and abiotic challenges. Jasmonic acid (JA), one of the immunity hormones in plants, triggers genome-wide transcriptional changes in response to insect attack and wounding. Although JA is known to affect the development of trichomes, epidermal appendages that form a protective barrier against various stresses, it remains unclear how JA interacts with developmental programs that regulate trichome development. In this study, we show that JA affects trichome length in tomato by releasing the transcriptional repression mediated by Jasmonate ZIM (JAZ) proteins. We identified SlJAZ4, a negative regulator preferentially expressed in trichomes, as the critical component in JA signaling in tomato trichomes. We also identified a homeodomain-leucine zipper gene, SlHD8, as the downstream regulator of JA signaling that promotes trichome elongation. SlHD8 is also highly expressed in trichomes and physically interacts with SlJAZ4. Loss-of-function mutations in SlHD8 caused shorter trichomes, a phenotype that was only partially rescued by methyl jasmonate treatment. Our dual-luciferase and chromatin immunoprecipitation-quantitative PCR assays revealed that SlHD8 regulates trichome elongation by directly binding to the promoters of a set of cell-wall-loosening protein genes and activating their transcription. Together, our findings define SlHD8-SlJAZ4 as a key module mediating JA-induced trichome elongation in tomato.

Preparation, characterization and application of CS@PDA@Fe3O4 nanocomposite as a new magnetic nano-adsorber for the removal of metals and dyes in wastewater.

This study aimed to develop a novel magnetic chitosan/dopamine/Fe3O4 nano-adsorber (CS@PDA@Fe3O4) for the removal of heavy metal ions and organic dye molecules from aqueous solution. CS@PDA@Fe3O4 was prepared by surface modification of PDA/Fe3O4 nanoparticles with chitosan using IPTES as the cross-linker. The surface structure, composition, and properties of the CS@PDA@Fe3O4 nano-adsorber were characterized by elemental (EDS), spectroscopic (XRD, XPS, and FT-IR), magnetic intensity (VSM), surface and morphological (TEM and SEM) analyses. In order to study its adsorption behavior, equilibrium and kinetics studies were carried out through batch experiments. Additionally, the influences of the pH value, initial concentration, adsorbent dose, and contact time were also evaluated. The CS@PDA@Fe3O4 nano-adsorber exhibited high adsorption capacity especially for Cu(ii), with a maximum adsorption capacity of 419.6 mg g-1. The experimental data were well described by the Langmuir isotherm kinetic models.

[Determination of ten kinds of α-hydroxy acids in cosmetics with quantitative analysis of multi-components by single marker].

OBJECTIVE: To establish a method for determination of ten kinds of α-hydroxy acids in cosmetics with quantitative analysis of multi-components by single marker(QAMS). METHODS: The analytes were separated by high performance liquid chromatography on a Venusil XBP C_8 column(4. 6 mm×250 mm, 5 µm), with the mobile phases of ammonium dihydrogen phosphate buffer-methonal under a gradient elution. The components were detected at the wavelengths of 214 nm using a diode array detector. Citric acid was used as the internal standard to determine the relative correction factors(RCFs) of the nine other α-hydroxy acids, in order to calculate their contents in samples by their RCFs. RESULTS: Good linearity with correlation coefficients greater than 0. 9994 was obtained for all the analytes. Stabilities within 24 h and precision of ten α-hydroxy acids were all good. Recoveries of the method were from 89. 3% to 105. 0% at three concentration levels, with the relative standard deviation(RSD) from 1. 0% to 2. 9%. Nine batches of samples were determined by QAMS, as well as the standard curve method(SCM). The relative average deviations(RAD) were below 3. 2% between the result of the two method, which showed good feasibility and accuracy of QAMS. CONCLUSION: The method is simple, accurate and beneficial to the saving of reference substances, which is suitable for the determination of ten kinds of α-hydroxy acids in cosmetics.

Characterization of PAHs in size-fractionated submicron atmospheric particles and their association with the intracellular oxidative stress.

The submicron atmospheric particulate matters (PMs), consisting of 7 size-resolved fractions, were collected by two Dekati low pressure impactors from December 2015 to January 2016 in Hangzhou, China. The chemical analysis revealed the higher accumulation efficiency of polycyclic aromatic hydrocarbons (PAHs) in the finer submicron PMs, and 77.0% of particulate PAHs in PM1 were associated with PM0.4. Moreover, the BaP equivalent concentrations (BaPeq) were evaluated for size-fractionated submicron PMs, indicating that 77.2% of carcinogenicity of particulate PAHs in PM1 were associated with PM0.4. In the cytotoxic tests, a significant size-dependent decrease of glutathione (GSH) level was observed in the PMs-exposed human pulmonary epithelial cells (A549), demonstrating the greater intracellular oxidative stress induced by the finer submicron PMs. The results also suggested that 82.4% of PM1-induced oxidative stress were associated with PM0.4, and the intracellular oxidative stress was significantly correlated with the particulate PAHs. Therefore, besides PM10, PM2.5 and PM1, special attentions should be given to PM0.4 as well.

Transmission and Accumulation of Nano-TiO2 in a 2-Step Food Chain (Scenedesmus obliquus to Daphnia magna).

The recent increase in nanomaterial usage has led to concerns surrounding its health risks and environmental impact. The food chain is an important pathway for high-trophic-level organisms absorbing and enriching nanomaterials. Our study therefore simulated nanometer titanium dioxide (nano-TiO2) transfer along a 2-step food chain, from the unicellular alga Scenedesmus obliquus to the water flea Daphnia magna. We also explored the effect of sodium dodecyl benzene sulfonate (SDBS) on nano-TiO2 bioavailability. A suspension of 10 mg/L nano-TiO2 was optimally dispersed in aqueous solutions by 5 mg/L SDBS. After 72 h, S. obliquus growth was not significantly affected by 10 mg/L nano-TiO2, 5 mg/L SDBS and their mixed suspension. SDBS not only improved nano-TiO2 stability in water, but also increased its uptake in S. obliquus and enhanced its accumulation in D. magna. Our study suggests that nano-TiO2 is mildly toxic to S. obliquus, and can be transferred along the aquatic food chain with a biomagnification effect.

[Experimental study of tissue-engineered bone constructed with simvastatin carried by PLGA/CPC and bone marrow stromal cells].

PURPOSE: To study the feasibility of tissue engineered bone constructed with simvastatin carried by PLGA/CPC and bone marrow stromal cells (BMSCs) and screen the effective drug loading of simvastatin. METHODS: Solvent casting-particle leaching technology combined with the phase separation process was used to prepare the different concentrations (simvastatin mass: 0.1, 0.5, 1 mg) of simvastatin carried by PLGA/CPC composite scaffold materials. Scanning electron microscopy was used to observe the porosity and drug release curve was drawn; Alizarin red staining and type I collagen staining were applied to observe the effect of osteogenic medium and simvastatin on the role of BMSCs to the osteogenetic differentiation. The induced passage 3 cells after dil staining were mixed with the composite scaffold material to a complex. Scanning electron microscopy and laser confocal microscope were used to observe the adhesion on the complex. CCK-8 and alkaline phosphatase (ALP) were applied to observe the proliferation and differentiation. SPSS 18.0 software package was used for statistical analysis. RESULTS: The scaffold porosity was more than 90% with an average aperture of 200-300 µm. The drug released slowly. There was no obvious interpretation. Type I collagen showed positive expression. Alizarin red staining proofed the formation of mineralization nodules in group which was induced with the conditional medium and simvastatin. 0.5 mg group showed cells adhered to the inner surface of the scaffold material and could significantly promote the proliferation and differentiation of cells. CONCLUSIONS: Combination of simvastatin and osteogenic medium can effectively promote the differentiation of BMSCs. Simvastatin carried by PLGA/CPC scaffold materials is an ideal tissue engineering scaffold material. PLGA/CPC scaffold containing 0.5 mg simvastatin can effectively promote the proliferation and differentiation of BMSCs. Supported by Natural Science Foundation of Jilin Province (201215052).

Synthesis, photo- and electro-luminescence of 3-benzoxazol-2-yl-coumarin derivatives.

Two coumarin derivatives containing electron-transporting benzoxazolyl moiety, 7-(diethylamino)-3-(benzoxazol-2-yl)coumarin (DABOC) and 3-(benzoxazol-2-yl)benzo[5,6]coumarin (BOBC), were synthesized and characterized. The photoluminescence and electroluminescence of the compounds were investigated detailedly. The compounds exhibited strong blue-green emissions in both solution and solid states, but the devices with DABOC as the emitting layer exhibited orange emission and maximum luminous efficiency of 2.8 cd/A and maximum luminance of 8,800 cd/m(2), and the devices with BOBC displayed orange-white emission and maximum luminous efficiency of 0.13 cd/A and maximum luminance of 540 cd/m(2).

Synthesis and rare earth metal ion-sensing properties of aza-crown derivative incorporating with diaryl-1,3,4-oxadiazole.

A new fluorescent chemosensor (A18C6-Ox) in which a monoaza-18-crown-6 is linked to a diaryl-1,3,4-oxadiazole fluorophore by a methylene spacer has been synthesized to evaluate binding interaction with the rare earth ions by means of absorption and emission spectrophotometry. Absorption spectra of A18C6-Ox showed a broad band at 289nm and there was no significant change in the presence of Sc3+, La3+, Pr3+, Sm3+, Gd3+, Tb3+, Yb3+ and Lu3+ except for Ce3+ and Eu3+. From the emission spectral change of A18C6-Ox, interaction of the rare earth ions with A18C6-Ox is very strong. The formation of A18C6-Ox complexing with Sc3+, La3+, Pr3+, Sm3+, Gd3+, Tb3+, Yb3+ and Lu3+ leads to an increase in fluorescence intensity of A18C6-Ox, while Ce3+ and Eu3+ ions interact strongly causing fluorescence quenching of A18C6-Ox. In addition, the optimal complexation stoichiometry of the rare earth ions with A18C6-Ox was investigated by the fluorescent titration.

[Chiral separation of racemic epoxiconazole on cellulose tris(3,5-dimethylphenylcarbamate) chiral stationary phase using high performance liquid chromatography].

The two pairs of enantiomers of epoxiconazole were resolved using normal phase, reversed-phase and polar organic solvent high performance liquid chromatography on cellulose tris(3,5-dimethylphenylcarbamate) (CDMPC) chiral stationary phase, separately. The effects of different mobile phase compositions on the retention factor, separation factor and resolution in the chiral separation of epoxiconazole were investigated. It can be baseline separated on a Chiralcel OD-H column packed with CDMPC chiral stationary phase when methanol-water (80: 20, v/v) was used as the mobile phase, the resolutions of the two pairs of enantiomers were 1.64 and 6.50, respectively.

[Effect of the bonding amounts of chiral ligand exchange chromatographic stationary phases on the enantioseparation of amino acids].

L-proline chiral stationary phases with various bonding amounts for ligand exchange chromatography were prepared by treating silica gel with 3-glycidoxypropyltrimethoxysilane and bonding L-proline. The bonding amounts of L-proline chiral stationary phase were controlled effectively and characterized by IR and elemental analysis. Some DL-amino acids were separated and the influences of the bonding amounts on the efficiency of resolution of DL-amino acids by ligand exchange chromatography were briefly discussed and explained by the mechanism of the separation.