Laccase GhLac1 Modulates Broad-Spectrum Biotic Stress Tolerance via Manipulating Phenylpropanoid Pathway and Jasmonic Acid Synthesis.

Plants are constantly challenged by a multitude of pathogens and pests, which causes massive yield and quality losses annually. A promising approach to reduce such losses is to enhance the immune system of plants through genetic engineering. Previous work has shown that laccases (p-diphenol:dioxygen oxidoreductase, EC 1.10.3.2) function as lignin polymerization enzymes. Here we demonstrate that transgenic manipulation of the expression of the laccase gene GhLac1 in cotton (Gossypium hirsutum) can confer an enhanced defense response to both pathogens and pests. Overexpression of GhLac1 leads to increased lignification, associated with increased tolerance to the fungal pathogen Verticillium dahliae and to the insect pests cotton bollworm (Helicoverpa armigera) and cotton aphid (Aphis gosypii). Suppression of GhLac1 expression leads to a redirection of metabolic flux in the phenylpropanoid pathway, causing the accumulation of JA and secondary metabolites that confer resistance to V. dahliae and cotton bollworm; it also leads to increased susceptibility to cotton aphid. Plant laccases therefore provide a new molecular tool to engineer pest and pathogen resistance in crops.

Simultaneous Delivery of Highly Diverse Bioactive Compounds from Blend Electrospun Fibers for Skin Wound Healing.

Blend emulsion electrospinning is widely perceived to destroy the bioactivity of proteins, and a blend emulsion of water-soluble and nonsoluble molecules is believed to be thermodynamically unstable to electrospin smoothly. Here we demonstrate a method to retain the bioactivity of disparate fragile biomolecules when electrospun. Using bovine serum albumin as a carrier protein; water-soluble vitamin C, fat soluble vitamin D3, steroid hormone hydrocortisone, peptide hormone insulin, thyroid hormone triiodothyronine (T3), and peptide epidermal growth factor (EGF) were simultaneously blend-spun into PLGA-collagen nanofibers. Upon release, vitamin C maintained the ability to facilitate Type I collagen secretion by fibroblasts, EGF stimulated skin fibroblast proliferation, and insulin potentiated adipogenic differentiation. Transgenic cell reporter assays confirmed the bioactivity of vitamin D3, T3, and hydrocortisone. These factors concertedly increased keratinocyte and fibroblast proliferation while maintaining keratinocyte basal state. This method presents an elegant solution to simultaneously deliver disparate bioactive biomolecules for wound healing applications.

[Toxic effects of polystyrene and dibutyl phthalate on purple lettuce]. / èšè‹¯ä¹™çƒ¯ä¸Žé‚»è‹¯äºŒç”²é ¸äºŒä¸é ¯å ±å­˜å¯¹ç´«å¶ç”Ÿèœçš„æ¯’æ€§æ•ˆåº”.

As a carrier of environmental pollutants, microplastics have received wide concerns in recent years. However, the direct and indirect effects of the coexistence of polystyrene particles (PS) and pollutants on vegetables are still unclear. Here, the combined effects of 0.25, 0.50, 1.0 mg·mL-1 PS and 5 mg·L-1 dibutyl phthalate (DBP) on the biomass and biochemical indices of purple lettuce were investigated in hydroponic experiments. The results showed that the presence of PS increased the inhibition of DBP on lettuce biomass and increased O2-· content in roots and leaves relative to the control group with DBP alone, with positive consequences on the activities of supero-xide dismutase, ascorbic acid peroxidase, dehydroascorbate reductase and monodehydroascorbate reductase. According to transmission electron microscope analysis, plasmolysis occurred in root cells under the treatment of DBP alone, cell wall was damaged in PS-only treatment, and the negative effect was enhanced when DBP and PS coexisted. Therefore, the combined pollution of PS and DBP aggravated the toxic effect on purple lettuce.

Bio-based UV protective films prepared with polylactic acid (PLA) and Phoebe zhennan extractives.

In this study, diethyl ether extractives were isolated from Phoebe zhennan wood and then added into PLA matrix for the preparation of UV protective films (UV-PF). The results revealed that the diethyl ether extractives had good compatibility with PLA. The prepared UV-PF with the addition of 24 wt% extractives showed complete absorption of UV-C (200-280 nm) and UV-B (280-315 nm) and more than 90% absorption of UV-A (315-400 nm), indicating the addition of extractives into PLA contributed to the super UV resistant ability of the PLA based films. The UV-PF still exhibited excellent UV absorbability after strong UV light irradiation. The differential Scanning Calorimetry (DSC) analysis of the films showed that the UV-PF had relatively low thermal degradation temperature compared to the neat PLA films (PF), while the UV-PF showed stronger tensile strength with comparison to that of the PF. The results on the chemical composition analysis of the diethyl ether extractives revealed that the UV absorbability of the UV-PF may own to the benzene structure, CO bonds, CC bonds in the constituents of the extractives, which all have strong absorption in the near UV-region (200-400 nm).

Impact of atrazine and nitrogen fertilizers on the sorption of chlorotoluron in soil and model sorbents.

Sorption of chlorotoluron in ammonium sulfate, urea and atrazine multi-solutes system was investigated by batch experiments. The results showed application of nitrogen fertilizers to the soil could affect the behavior of chlorotoluron. At the same concentration of N, sorption of chlorotoluron decreased as the concentration of atrazine increased on the day 0 and 6 in soil, respectively. The sorption of chlorotoluron increased from 0 to 6 d when soils were preincubated with deionized water, ammonium sulfate and urea solution for 6 d. That indicated incubation time was one of the most important factors for the sorption of chlorotoluron in nitrogen fertilizers treatments. The individual sorption isotherms of chlorotoluron in rubbery polymer and silica were strictly linear in single solute system, but there were competition sorption between pesticides or between pesticides and nitrogen fertilizers. That indicated the sorption taken place by concurrent solid-phase dissolution mechanism and sorption on the interface of water-organic matter or water-mineral matter.

Novel use for polyvinylpyrrolidone as a macromolecular crowder for enhanced extracellular matrix deposition and cell proliferation.

Macromolecular crowding (MMC) is a biophysical effect that governs biochemical processes inside and outside of cells. Since standard cell culture media lack this effect, the physiological performance of differentiated and progenitor cells, including extracellular matrix (ECM) deposition, is impaired in vitro. To bring back physiological crowdedness to in vitro systems, we have previously introduced carbohydrate-based macromolecules to culture media and have achieved marked improvements with mixed MMC in terms of ECM deposition and differentiation of mesenchymal stem cells (MSCs). We show here that although this system is successful, it is limited, due to viscosity, to only 33% of the fractional volume occupancy (FVO) of full serum, which we calculated to have an FVO of approximately 54% v/v. We show here that full-serum FVO can be achieved using polyvinylpyrrolidone (PVP) 360 kDa. Under these conditions, ECM deposition in human fibroblasts and MSCs is on par, if not stronger than, with original MMC protocols using carbohydrates, but with a viscosity that is not significantly changed. In addition, we have found that the proliferation rate for bone marrow-derived MSCs and fibroblasts increases slightly in the presence of PVP360, similar to that observed with carbohydrate-based crowders. A palette of MMC compounds is now emerging that enables us to tune the crowdedness of culture media seamlessly from interstitial fluid (9% FVO), in which the majority of tissue cells might be based, to serum environments mimicking intravascular conditions. Despite identical FVO's, individual crowder size effects play a role and different cell types appear to have preferences in terms of FVO and the crowder that this is achieved with. However, in the quest of crowders that we have predicted to have a smoother regulatory approval path, PVP is a highly interesting compound, as it has been widely used in the medical and food industries and shows a novel promising use in cell culture and tissue engineering.

[Soft tissue changes of upper lip in patients with class I malocclusion with different premolar extraction patterns].

OBJECTIVE: The purpose of this retrospective cephalometric study was to compare changes of the upper lip soft tissue in patients with Class I malocclusion after extraction of either first premolars or second premolars. METHODS: The pretreatment and posttreatment records of 50 patients were used in the study. And 25 patients involved extraction of first premolars and 25 patients involved the extraction of second premolars. The lateral cephalometric radiographs taken before and after treatment were traced and measured. 15 typical values of soft tissue were measured in Winceph 7.0 software and statistical analysis was carried by SPSS 10.0 software. RESULTS: 1) The horizontal and vertical lines were not significant different in the two extraction group before the treatment. But after the treatment the vertical changes of upper lip (A'-X, UL-X) were more apparent in the second premolar extraction group (P < 0.05). 2)In the soft tissue measurements, the values of Sn-A'-UL in the first premolar extraction group were less than those in the second premolar extraction group significantly before the treatment. After the treatment all the patients had a significant increase in length of upper lip. At the same time, UL-EP, A'-EP distances were diminished obviously (P < 0.05). But the changes were not significant difference between the two premolar extraction groups (P > 0.05). CONCLUSION: The upper lips both changed remarkably after the treatment and there was no significant difference between the two premolar extraction groups.

[Soft tissue changes of chin with different premolar extraction patterns].

PURPOSE: The purpose of this retrospective cephalometric study was to compare the change of chin soft tissue in patients with Class I malocclusion after extraction of either first premolars or second premolars. METHODS: The pretreatment and posttreatment records of 50 patients were used in the study. Twenty-five patients underwent extraction of first premolars and 25 patients underwent extraction of second premolars. All the patients were skeletal Class I and matched by the gender, age, facial divergence and crowding. The lateral cephalometric radiographs taken before and after treatment were traced and measured. The data was analyzed using SPSS 10.0 software package for Student's t test. RESULTS: (1)The horizontal and vertical changes was both significant in the second extraction group compared with first extraction group, and the horizontal change was more apparent. But only vertical change was apparent in the first extraction group. (2)In the soft tissue measurements, the value of soft tissue facial angle and B'-Pos-FH in the first extraction group was less than those in the second extraction group significantly. After treatment all the patients had an increase in S-Ns-Pos angle, soft tissue facial angle, B'-Pos-FH and depth of mentolabial groove. At the same time, soft tissue convexity angle was diminished obviously. But the change was not significant between the two premolar extraction groups. CONCLUSIONS: The growth pattern tends to vertical pattern in the first premolar extraction group and the horizontal growth of chin is more obvious in the second premolar extraction group. There is no significant difference of chin soft tissue changes between the two premolar extraction groups.

Patterned Au/poly(dimethylsiloxane) substrate fabricated by chemical plating coupled with electrochemical etching for cell patterning.

In this paper, we present a novel approach for preparing patterned Au/poly(dimethylsiloxane) (PDMS) substrate. Chemical gold plating instead of conventional metal evaporation or sputtering was introduced to achieve a homogeneous gold layer on native PDMS for the first time, which possesses low-cost and simple operation. An electrochemical oxidation reaction accompanied by the coordination of gold and chloride anion was then exploited to etch gold across the region covered by electrolyte. On the basis of such an electrochemical etching, heterogeneous Au/PDMS substrate which has a gold "island" pattern or PDMS dots pattern was fabricated. Hydrogen bubbles which were generated in the etching process due to water electrolysis were used to produce a safe region under the Pt auxiliary electrode. The safe region would protect gold film from etching and lead to the formation of the gold "island" pattern. In virtue of a PDMS stencil with holes array, gold could be etched from the exposed region and take on the PDMS dots pattern which was selected to for protein and cell patterning. This patterned Au/PDMS substrate is very convenient to construct cytophobic and cytophilic regions. Self-assembled surface modification of (1-mercaptoundec-11-yl)hexa(ethylene glycol) on gold and adsorption of fibronectin on PDMS are suitable for effective protein and cell patterning. This patterned Au/PDMS substrate would be a potentially versatile platform for fabricating biosensing arrays.

Cytosensing and evaluation of cell surface glycoprotein based on a biocompatible poly(diallydimethylammonium) doped poly(dimethylsiloxane) film.

In this paper, we constructed an interface that not only retains viability of immobilized BGC823 human gastric carcinoma cells (BGC823 cells) but also efficiently resists nonspecific adsorption of the P-glycoprotein antibody and its secondary antibody, which enabled us to sensitively detect the number of cells and P-glycoproteins on the BGC823 cell surface by the immunoassay method. Preparation of the film was quite simple and inexpensive just by spin-coating poly(dimethylsiloxane) (PDMS) doped with poly(diallydimethylammonium) (PDDA) on the surface of gold electrodes. The composite film's biocompatibility, antinonspecific adsorption ability, and the conductivity for electrochemical probe ([Fe(CN)6]3-/4-) were proved by cell culture experiments, blocking experiments, and electrochemical experiments. Compared with PDMS and PDMS doped with poly(sodium 4-styrenesulfonate) (PSS), the PDMS-PDDA composite film showed a predominant ability to capture cells due to electrostatic reaction between the presence of positively charged PDDA and the negatively charged glycocalyx on the surface of cells. On the advantage of electrochemical immunoassay with a signal amplification path by using biocatalytic precipitation of an insoluble product, differential pulse voltammetry (DPV) measurement based on the changes of electron-transfer resistance was introduced to detect the cell amount and monitor growing states of cells like adhesion, spread, proliferation, and apoptosis on the electrodes. Optimally, signal response was proportional to the logarithm of cell concentration ranging from 1.0 x 10(3) to 5.0 x 10(7) cells mL(-1) with a detection limit of 7.2 x 10(2) cells mL(-1). On the basis of the special property for resisting nonspecific adsorption of this composite film, an ultraviolet and visible (UV-vis) absorption spectrum with one-step immunoreaction was employed to evaluate the P-glycoprotein on the BGC823 cell surface. The P-glycoprotein on a single living intact BGC823 cell was detected correspondingly to 4.7 x 10(7) molecules. The work implied that the composite film possessed potential applications for biosensing and convenient evaluation of surface glycoprotein on living cells.

[Study of the crestal bone height and root length technique change of impacted canines treated by modified Nance arch technique].

PURPOSE: The purpose of this study was to evaluate the crestal bone height and root length change after orthodontic treatment of impacted canines with modified Nance arch technique. METHODS: 8 maxillary impacted canines were treated with modified Nance arch technique. The canines of other side which were naturally erupted were used for self-control. Pre-treatment and post-treatment panoramic radiographs were measured and the following data was collected: (1)The distance of the impacted canine migration and the angle change of the impacted canine; (2)Crestal bone height and root length between previously impacted canines and adjacent lateral incisors and premolars(experimental)and contralateral control teeth. The crestal bone height and root length were compared using a paired t test with SPSS11.0 software package. RESULTS: The mean distance of the impacted canine migration was 18.43 mm and the mean angle change on the panoramic radiograph was 32.7 degrees. No difference was found in the crestal bone height and the root length between the adjacent lateral incisors and premolars(experimental) and the contralateral control teeth(P>0.05). CONCLUSION: The combination of modified Nance arch with straight wire arch technique is a valid method to treat maxillary impacted canines.