Greenhouse covering cultivation promotes chlorophyll accumulation of tea plant (Camellia sinensis) by activating relevant gene expression and enzyme activity.

BACKGROUND: The tea plant (Camellia sinensis (L.) O. Kuntze) is one of the most economically important woody crops. Plastic greenhouse covering cultivation has been widely used in tea areas of northern China. Chlorophyll is not only the crucial pigment for green tea, but also plays an important role in the growth and development of tea plants. Currently, little is known about the effect of plastic greenhouse covering cultivation on chlorophyll in tea leaves. RESULTS: To investigate the effect of plastic greenhouse covering cultivation on chlorophyll in tea leaves, color difference values, chlorophyll contents, gene expression, enzyme activities and photosynthetic parameters were analyzed in our study. Sensory evaluation showed the color of appearance, liquor and infused leaves of greenhouse tea was greener than field tea. Color difference analysis for tea liquor revealed that the value of ∆L, ∆b and b/a of greenhouse tea was significantly higher than field tea. Significant increase in chlorophyll content, intracellular CO2, stomatal conductance, transpiration rate, and net photosynthetic rate was observed in greenhouse tea leaves. The gene expression and activities of chlorophyll-metabolism-related enzymes in tea leaves were also activated by greenhouse covering. CONCLUSION: The higher contents of chlorophyll a, chlorophyll b and total chlorophyll in greenhouse tea samples were primarily due to higher gene expression and activities of chlorophyll-metabolism-related enzymes especially, chlorophyll a synthetase (chlG), pheophorbide a oxygenase (PAO) and chlorophyllide a oxygenase (CAO) in tea leaves covered by greenhouse. In general, our results revealed the molecular basis of chlorophyll metabolism in tea leaves caused by plastic greenhouse covering cultivation, which had great significance in production of greenhouse tea.

Computed Tomography-Based Morphometric Analysis of Lower Cervical Anterior Transpedicular Screw Fixation and Related Factors in the Chinese Population.

BACKGROUND: Anterior transpedicular screw (ATPS) internal fixation of the lower cervical spine is an alternative for patients who cannot tolerate combined anterior and posterior surgery. The cervical vertebral anatomy varies with many factors, including age, gender, height, weight, and race. METHODS: Three-dimensional (3D) CT reconstructions were performed on 122 patients. We selected the best level and measured the relevant parameters on both sides of the cervical vertebrae. RESULTS: We identified the entry point and orientation parameters of ATPS fixation for the C3-C7 vertebrae, and analyzed cervical pedicle parameters. Outer pedicle width (OPW), outer pedicle height (OPH), and pedicle axis length (PAL) were not correlated with body weight and age, but were positively correlated with body height (P < 0.05). After multiple linear regression analysis to exclude the effects of body height, no significant differences in OPW, OPH, and PAL were found between male and female subjects at most cervical levels. Pedicle cortical thickness was negatively correlated with age (P < 0.05). The percentage of pedicles with OPW <4.5 mm was: C3, 38.10%; C4, 34.92%; C5, 12.70%; C6, 9.52%; and C7, 0%. The percentage of pedicles with OPWs ≤4.5 mm, ≤4.0 mm, and ≤3.5 mm was higher among subjects with body height <160 cm. CONCLUSIONS: This study presents the internal anatomy of the cervical spine and provides accurate preoperative evaluation data for ATPS fixation. OPW, OPH, and PAL are positively correlated with body height, while pedicle cortical thickness is negatively correlated with age.

[Association of vitamin D receptor gene polymorphisms with susceptibility to bone and joint tuberculosis in Chinese Han population].

OBJECTIVE: To investigate the association between vitamin D receptor (VDR) gene Apa I polymorphism and the susceptibility to bone and joint tuberculosis in Chinese Han population. METHODS: Between May, 2015 and June, 2016, 100 patients with bone and joint tuberculosis and 100 healthy volunteers were recruited concomitantly in Heyuan Hospital of Traditional Chinese Medicine. Vitamin D receptor gene Apa I polymorphisms in these subjects were analyzed using SNaPshot. RESULT: The genotype frequencies of Apa I-AA, Apa I-Aa and Apa I-aa were 51%, 41%, and 8% in the case group and 33%, 55%, and 12% in the control group, respectively, showing significant differences between the two groups (P<0.05). The genotype of Apa I-AA was significantly higher in the case group with an odds ratio (OR) of 2.073 (95% CI: 1.142-3.763). CONCLUSION: The Apa I polymorphisms of the VDR gene are associated with the susceptibility to bone and joint tuberculosis in Chinese Han population, and individuals with a Apa I-AA genotype are at greater risks to develop bone and joint tuberculosis.

Facile Peeling Method as a Post-Remedy Strategy for Producing an Ultrasmooth Self-Assembled Monolayer for High-Performance Organic Transistors.

The modification of dielectric surface with a self-assembled monolayer (SAM) such as octadecyltrichlorosilane (OTS) is a widely used method to tune the electrical property of diverse electronic devices based on organic semiconductors, graphene, transition metal dichalcogenides (TMDs), and so forth. The surface roughness of self-assembled OTS monolayer is a key factor in determining its effect on device performance, but the preparation of an ultrasmooth OTS monolayer is a technologically challenging task. In this work, an ultrasmooth OTS monolayer is prepared via a facile peeling method, which may serve as a postremedy strategy to remove the protuberant aggregates. Such a method has not been reported before. With organic semiconductors as a testing model, ultrasmooth OTS may significantly improve the charge mobility of organic field-effect transistors (OFETs). P-type dinaphtho[2,3-b:2',3'-f]thieno[3,2-b]thiophene (DNTT) OFET with an ultrasmooth OTS monolayer yields good reproducibility and unprecendented maximum mobility of 8.16 cm(2) V(-1) s(-1), which is remarkably superior to that of the OFET with a pristine OTS monolayer. This work develops a simple method to resolve the common and significant problem of the quality of OTS modification, which would be highly promising for electronic applications as well as other fields such as surface and interface engineering.

[Fabrication of a new composite scaffold material for delivering rifampicin and its sustained drug release in rats].

OBJECTIVE: To fabricate a new composite scaffold material as an implant for sustained delivery of rifampicin and evaluate its performance of sustained drug release and biocompatibility. METHODS: The composite scaffold material was prepared by loading poly(lactic-co-glycolic) acid (PLGA) microspheres that encapsulated rifampicin in a biphasic calcium composite material with a negative surface charge. The in vitro drug release characteristics of the microspheres and the composite scaffold material were evaluated; the in vivo drug release profile of the composite scaffold material implanted in a rat muscle pouch was evaluated using high-performance liquid chromatography. The biochemical parameters of the serum and liver histopathologies of the rats receiving the transplantation were observed to assess the biocompatibility of the composite scaffold material. RESULTS: The encapsulation efficiency and drug loading efficiency of microspheres were (56.05±5.33)% and (29.80±2.88)%, respectively. The cumulative drug release rate of the microspheres in vitro was (94.19±5.4)% at 28 days, as compared with the rate of (82.23±6.28)% of composite scaffold material. The drug-loaded composite scaffold material showed a good performance of in vivo drug release in rats, and the local drug concentration still reached 16.18±0.35 µg/g at 28 days after implantation. Implantation of the composite scaffold material resulted in transient and reversible liver injury, which was fully reparred at 28 days after the implantation. CONCLUSION: The composite scaffold material possesses a good sustained drug release capacity and a good biocompatibility, and can serve as an alternative approach to conventional antituberculous chemotherapy.

[Genetic Characterization of Coxsackievirus A6 Strains Isolated in Ningxia Region, China, 2013～2015].

To study the genetic characteristics of coxsackievirus (CV)-A6 strains isolated from hand, food and mouth(HFMD)cases in Ningxia Province, China, in 2013~2015.A total of 998 specimens identified as non-EV71,non-CVA16 enteroviruses by real-time polymerase chain reaction were collected in 2013~2015and cultured using RD cells. The viral protein(VP)1gene of isolated strains was amplified by reverse transcription-polymerase chain reaction with degenerate primers and sequenced.Sequences were compared using the GenBank database by the BLAST algorithm to identify virus genotypes. All CV-A6 stains identified underwent homologous comparison and phylogenetic analyses. A total of 227 virus strains were isolated from 998 clinical specimens, and 61 stains were identified as CV-A6.Homologies of nucleotides and amino acids among Ningxia CV-A6 strains were 96.1%~99.8% and 98%~100%,respectively.The nucleotide homogeneity of Ningxia CV-A6 strains with Gudla strains, and the similarity of nucleotides and amino-acid sequences with VP1 of CV-A6 were 82.0%~83.5% and 93.8%~95.7%,respectively.CVA6 was the main pathogen of HFMD apart from EV71 and CV-A16 in Ningxia Province in 2013~2015.

Photothermal ablation of bone metastasis of breast cancer using PEGylated multi-walled carbon nanotubes.

This study investigates therapeutic efficacy of photothermal therapy (PTT) in an orthotropic xenograft model of bone metastasis of breast cancer. The near-infrared (NIR) irradiation on Multi-Walled Carbon Nanotubes (MWNTs) resulted in a rapid heat generation which increased with the MWNTs concentration up to 100 µg/ml. MWNTs alone exhibited no toxicity, but inclusion of MWNTs dramatically decreased cell viability when combined with laser irradiation. Thermographic observation revealed that treatment with 10 µg MWNTs followed by NIR laser irradiation resulted in a rapid increase in temperature up to 73.4±11.98 °C in an intraosseous model of bone metastasis of breast cancer. In addition, MWNTs plus NIR laser irradiation caused a remarkably greater suppression of tumor growth compared with treatment with either MWNTs injection or NIR irradiation alone, significantly reducing the amount of tumor-induced bone destruction. All these demonstrate the efficacy of PTT with MWNTs for bone metastasis of breast cancer.

Bimetallic carbide nanocomposite enhanced Pt catalyst with high activity and stability for the oxygen reduction reaction.

Nanocomposites consisting of the bimetallic carbide Co(6)Mo(6)C(2) supported on graphitic carbon ((g)C) were synthesized in situ by an anion-exchange method for the first time. The Co(6)Mo(6)C(2)/(g)C nanocomposites were not only chemically stable but also electrochemically stable. The catalyst prepared by loading Pt nanoparticles onto Co(6)Mo(6)C(2)/(g)C was evaluated for the oxygen reduction reaction in acidic solution and showed superior activity and stability in comparison with commercial Pt/C. The higher mass activity of the Pt-Co(6)Mo(6)C(2)/(g)C catalyst indicated that less Pt would be required for the same performance, which in turn would reduce the cost of the fuel cell electrocatalyst. The method reported here will promote broader interest in the further development of other nanostructured materials for real-world applications.

Sensitive DNA hybridization detection based on the deposition of gold nanoparticle on lyophobic surface.

An assay for the detection of DNA hybridization was developed using Ellipsometric Scanner (ES) as a detection method. The different deposition trends of Au nanoparticle on glutaraldehyde-covered Si substrate caused by the different electrostatic properties of Au nanoparticles after interaction with ssDNA and dsDNA respectively can be observed by measuring the ellipsometric parameter y. At the same time, the average height of the y with respect to the cross-sectional contour c can be described by y=0.0920+2.43c in the range of 5.4 to 27nM (r=0.943, c is target concentration, the unit is µM). This assay using ES imaging could successfully detect the total amounts of the target as low as 5.4fmol. The proposed assay system has the advantage of allowing label-free detection, high sensitivity, and operational simplicity.

A universal method to synthesize nanoscale carbides as electrocatalyst supports towards oxygen reduction reaction.

We have developed a general ion-exchange method of preparing a composite of low nanometre size carbide particles with controllable size less than 10 nm on carbon foams. The nanoarchitectures of the carbide nanoparticles on carbon foam are used to load Pt nanoparticles as electrocatalysts which show enhanced activity for the oxygen reduction reaction.

Reversed cell imprinting, AFM imaging and adhesion analyses of cells on patterned surfaces.

Cell adhesion and motility depend strongly on the interactions between cells and cell culture substratum. To observe the cell morphology at the interface between cells and artificial substratum or patterned surfaces, we have developed a technique named reversed cell imprinting. After culture and chemical fixation of the cells on a patterned hole array, a liquid polymer was poured on and UV cured, allowing taking off the cell-polymer assembly for a direct observation of the underside cell surface using atomic force microscopy. As expected, we observed local deformation of the cell membrane in the hole area with a penetration depth strongly dependent on the size and depth of the hole as well as the culture time. Quantitative analyses of Hela cells on patterned surfaces of polydimethylsiloxane (PDMS) revealed that the penetration was also position dependent over the cell attachment area due to the non-homogeneous distribution of the membrane stress. With the increase of the culture time, the penetration depth was reduced, in a close correlation with the increase of the cell spreading area. Nevertheless, both cell seeding and adhesion efficiency on high density hole arrays could be significantly increased comparing to that on a smooth surface. Patterned substrates are increasingly required to produce and interrogate new biomaterials for therapeutic benefit. Overall, this work suggests a strategy to endow conventional imaging methods with added functionality to enable easy observation of the underside cell morphology on topographic patterns.

[Genetic characteristics of entervirus 71 isolated in Ningxia Hui Autonomous region in 2009].

OBJECTIVE: To analyze the genetic characteristics of EV71 strains isolated from HFMD cases in Ningxia Hui Autonomous Region in 2009. METHODS: In 2009, totally 385 specimens from 344 HFMD cases were collected from Ningxia. Enterovirus isolation was performed in RD cell line from all the specimens. EV71 isolates were identified by specific RT-PCR from the positive cultures, and sequences of complete EV71 VP1 encoding region were determined for farther analyses. RESULTS: Totally from 126 EV strains isolated in this study, 58 EV71 strains (46%) were identified. And complete VP1 sequences of 46 EV71 strains were determined, and genetic analyses were performed. It was showed that the nucleotide identity of 46 Ningxia strains with the representatives of A and B genotypes were 81.7%-82.8% and 83.1%-85.2%, and the amino acid identity were 93.9%-95.9% and 96. 2%-97.9% respectively. The nucleotide identity of NingXia EV71 isolates with representatives of subgenotype C1, C2, C3, C4a, C4b, and C5 were 88.3%-90.6% (97.9%-99.6%), 88.3%-90.1% (97.9%-99.3%), 87.8%-89.0% (97.6%-98.9%), 94.2%-98.9% (97.9%-100%), 91.8%-94.1% (98.6%-99.6%), and 86.7%-89.1% (97.9%-98.9%). Phylogenetic tree analysis revealed that 46 stains were clustered with reference stains of subgenotype C4 and the Ningxia EV71 isolates were belonged to subgenotype C4a. CONCLUSION: EV71 of subgenotype C4a had spread widely in Ningxia in 2009, which was absolutely predominant type in Ningxia in 2009 and also as the predominant type in China mainland since 2005.

[Effect of post-annealing on the structure and fluorescence properties of YMnO3 thin films].

YMnO3 thin films deposited on Si (100) substrate by pulsed laser deposition at room temperature were annealed at different temperatures. The microstructure and fluorescent emission properties of these films were studied using XRD and UV-Vis spectroscopy. The results show that polycrystalline YMnO3 thin films can be obtained through post-annealing, in which hexagonal phase and orthorhombic phase coexist. And with increasing the temperature, the ratio of orthorhombic phase to hexagonal phase varies considerably. The results also show that fluorescence peaks in the wavelength range of 430-620 nm maybe originate from the transition from 5T2 to 5E of Mn3+. The intensity of fluorescence peaks is enhanced with increasing the temperature. However, the positions of fluorescence peaks remain invariable. These results indicate that the change in the film structure affects the transition probability greatly but almost has no effect on the position of energy level. Meanwhile, the relative intensity ratio of cyan fluorescence peak to green fluorescence peak is almost unchanged.

[Fluorescence emission properties of Ni-doped ZnO films].

Ni-doped ZnO films were deposited on Si(100) by pulsed laser deposition(PLD) at room temperature. Fluorescence emission properties of the films were measured using VARAIN Cary-Eclips 500 fluorescence spectrum analyzer. Two peaks centered respectively at about 360 and 380 nm were observed. The origin of the ultraviolet peak at 360 nm was investigated through doping Ni into the ZnO films. It was found that the intensity of this ultraviolet peak changed with Ni content while its position remained stable. The fluorescence emission of the samples was optimal when Ni:ZnO was 5 mol%, indicating that the peak centered at 360 nm might originate from the composite transition between the splitting valence band and conduction band, not from the entrance of the impurity energy level into the conduction band after doping.