A novel apatite, Lu5(SiO4)3N:(Ce,Tb), phosphor material: synthesis, structure and applications for NUV-LEDs

Crystal structure and luminescence properties of novel lutetium containing nitride–apatite Lu₅(SiO₄)₃N:Ce³⁺,Tb³⁺.

Light intensity stabilization based on the second harmonic of the photoelastic modulator detection in the atomic magnetometer

The fluctuations of the probe light intensity seriously affect the performance of the sensitive atomic magnetometer. Here we propose a novel method for the intensity stabilization based on the second harmonic component of the photoelastic modulator (PEM) detection in the atomic magnetometer. The method not only could be used to eliminate the intensity fluctuations of the laser source, but also remove the fluctuations from the optical components caused by the environment. A relative fluctuation of the light intensity of 0.035% was achieved and the corresponding fluctuation of the output signal of the atomic magnetometer has decreased about two orders of magnitude from 4.06% to 0.041%. As the scheme proposed here only contains optical devices and does not require additional feedback controlled equipments, it is especially suitable for the integration of the atomic magnetometer.

Tissue culture characteristics of maize (Zea mays L.) haploid coleoptile sections

Doubled haploid (DH) technology, which is used for rapidly purifying genetic resources, is a key technology in modern maize breeding. The present study evaluated the tissue culture characteristics of maize haploid coleoptile sections, in order to provide a new way of haploid doubling. With 20 combinations of haploid coleoptile sections, obtained by hybridization within Reid, Tangsipingtou, and Term-tropical groups, as explants, we analyzed the induction and differentiation rate of callus, observed the number of root tip chromosomes in regenerated plants, and analyzed the pollen fertility. In addition, we used 47 SSR markers to analyze the genotypes of regenerated plants. The Reid and Tangsipingtou groups had significantly higher induction rates of haploid coleoptile callus compared to the Term-tropical group. Fifteen haploid plants were obtained which had 10 chromosomes in the root tips as assessed by I-KI staining. It was also noticed that the pollen of pollinated anthers were partially fertile. The haploid plants had genetic stability and showed no variation. The Reid and Tangsipingtou groups had good culture characteristics of haploid coleoptile sections, while the Term-tropical group had poor culture characteristics. Genotypes of haploid plants generated by tissue culture were evidenced to come from recombinant types of parents. Thus, this study established a tissue culture system of maize haploid coleoptile.

Comprehensive analysis of antibody recognition in convalescent humans from highly pathogenic avian influenza H5N1 infection

Understanding the mechanism of protective antibody recognition against highly pathogenic avian influenza A virus H5N1 in humans is critical for the development of effective therapies and vaccines. Here we report the crystal structure of three H5-specific human monoclonal antibodies bound to the globular head of hemagglutinin (HA) with distinct epitope specificities, neutralization potencies and breadth. A structural and functional analysis of these epitopes combined with those reported elsewhere identifies four major vulnerable sites on the globular head of H5N1 HA. Chimeric and vulnerable site-specific mutant pseudoviruses are generated to delineate broad neutralization specificities of convalescent sera from two individuals who recovered from the infection with H5N1 virus. Our results show that the four vulnerable sites on the globular head rather than the stem region are the major neutralizing targets, suggesting that during natural H5N1 infection neutralizing antibodies against the globular head work in concert to provide protective antibody-mediated immunity.

Smoking attenuated the association between IκBα rs696 polymorphism and defective spermatogenesis in humans

Defective spermatogenesis is prevalent in infertile men, but the molecular mechanisms underlying its aetiology are largely unknown. In this study, a proposed association between IκBα SNPs, smoking-related ROS and sperm quality was investigated. Two polymorphisms in the IκBα gene, rs2233406 and rs696 were genotyped in 342 controls and 338 patients with defective spermatogenesis from a southern Chinese population. The results showed the rs696 AA genotype to be significantly more common (21.60% versus 14.33%, P = 0.013) and the rs696 GG genotype to be significantly rarer (28.99% versus 37.13%, P = 0.024) in the cases than in the controls. After subjects were stratified into smokers and nonsmokers, these differences were only observed in nonsmokers. Further analysis showed the rs696 AA genotype to be significantly closely associated with defective spermatogenesis in all subjects (P = 0.014, OR = 1.647) and in nonsmokers (P = 0.036, OR = 1.889). In a TM3 cell model, exposure to cigarette smoke condensate was found to activate NF-κB luciferase activity and altered transcriptional level of NF-κB pathway genes. In conclusion, this study demonstrates an association between functional polymorphisms of the IκBα rs696 and cigarette smoking with the risk of defective spermatogenesis, suggesting some interaction between the NF-κB signalling pathway and smoking-related ROS in human spermatogenesis.

Role of Glycol Chitosan-incorporated Ursolic Acid Nanoparticles in the Treatment of Osteosarcoma

Purpose: To investigate the effect of ursolic acid (UA)-incorporated glycol chitosan (GC) nanoparticles on inhibition of human osteosarcoma.Methods: U2OS and Saos-2 osteosarcoma cells were transfected with ursolic acid (UA) incorporated glycol chitosan (GC) nanoparticles. Ultraviolet (UV)  spectrophotometry was used to measure drug contents in nanoparticles at 365 nm with empty GC vehicles as blank. Bicinchoninic acid assay (BCA) method was employed to determine protein concentration. Identification of apoptosis and necrosis in osteosarcoma cells was performed by propidium iodide and FITC-annexin V reagents, respectively. FAC Scan flow cytometry was used to analyse apoptotic cells.Results: Among the range of UA concentrations tested, the minimum effective concentration was 10 μM with half inhibitory concentration IC50 of 25 μM. In U2OS cells, treatment with 10 and 25 μM UAinduced apoptosis in 5.89 ± 3.90 and 60.54 ± 5.40 % cells, respectively, compared to 2.05 ± 1.01 % cells for control. In Saos-2 cells, exposure to 10 and 25 μM UA induced apoptosis in 9.86 ± 8.89 and 47.54 ± 14.5 % cells, respectively, compared to 1.79 ± 0.23 % for control cells. Western blot analysis revealed  translocation of Bax and Bcl-2 proteins from mitochondria to cell cytosol. Increase in UA concentration  from 10 μM to 25 μM led to increase in the proportion of cells in G0/G1 phase and decrease in the number of cells in S and G2/M phases. These results confirm that UA transfection arrests cell cycle in G0/G1 phase in human osteosarcoma cell lines.Conclusion: UA transfection resulted in the inhibition of cell proliferation, Ezh2 expression inhibition, and apoptosis via mitochondrial pathway due to decrease in membrane potential and release of cytochrome C, as well as cell cycle arrest in G0/G1 phase.Keywords: Osteosarcoma, Cell cycle arrest, Palliation, Glycol chitosan, Ursolic acid

Comparison of the after discharges induced by electrical stimulation of the prefrontal cortex in urethane- and ketamine-anesthetized mice

OBJECTIVE

The study aims to compare the effects of urethane and ketamine anesthesia on kindling-induced after discharges (AD).

MATERIALS AND METHODS

We divided forty 4-6 week old female C57BL/6J mice into two groups: one group was anesthetized with urethane (n = 20) and the other with ketamine (n = 20). Kindling was with an electrical stimulation (ES) consisting of a 1-s pulse train of 60 1-ms biphasic pulses at an initial intensity of 700 µA, delivered to the pre-frontal cortex every minute. Ten to fifteen minutes after the first AD was induced, identical electrical stimuli were delivered every 10 minutes for 200 minutes. EEG was continuously recorded from 15 minutes before the first ES until 10 minutes after the last ES. The EEG wave spectrum was analyzed by Fast Fourier Transform and the power spectrum densities (PSDs) of the δ, θ, α, β and γ bands were calculated. EEG wave amplitude was assessed using the root mean square value (RMS).

RESULTS

In the urethane group, an initial AD was induced in 70% of mice following 39 ES. In the ketamine group, an initial AD was induced in 60% of mice following 74 ES. The changes in EEG spectra were similar in both groups. Pre-AD, EEG waves predominantly consisted of δ and θ components. During AD, γ and β components increased significantly (p < 0.05). Post-AD, β and γ components decreased and the δ: θ ratio increased to pre-AD levels.

CONCLUSIONS

Our data suggest that AD can be induced by kindling stimulation of the pre-frontal cortex in mice under either urethane or ketamine anesthesia.

Unraveling the storage mechanism in organic carbonyl electrodes for sodium-ion batteries

Organic carbonyl compounds represent a promising class of electrode materials for secondary batteries; however, the storage mechanism still remains unclear. We take Na2C6H2O4 as an example to unravel the mechanism. It consists of alternating Na-O octahedral inorganic layer and π-stacked benzene organic layer in spatial separation, delivering a high reversible capacity and first coulombic efficiency. The experiment and calculation results reveal that the Na-O inorganic layer provides both Na(+) ion transport pathway and storage site, whereas the benzene organic layer provides electron transport pathway and redox center. Our contribution provides a brand-new insight in understanding the storage mechanism in inorganic-organic layered host and opens up a new exciting direction for designing new materials for secondary batteries.

Complete mitochondrial genome of the Chinese Hwamei Garrulax canorus (Aves: Passeriformes): the first representative of the Leiothrichidae family with a duplicated control region

The Chinese Hwamei Garrulax canorus, a member of the family Leiothrichidae, is commonly found in central and southern China, northern Indochina, and on Hainan Island. In this study, we sequenced the complete mitochondrial genome of G. canorus. The circular mitochondrial genome is 17,785 bp in length and includes 13 protein-coding genes, 22 transfer RNA (tRNA) genes, and two ribosomal RNA genes. In addition, two copies of highly similar putative control regions were observed in the mitochondrial genome. As found in other vertebrates, most of the genes are coded on the H-strand, except for one protein-coding gene (nad6; NADH dehydrogenase subunit 6) and eight tRNA genes (tRNA(Gln), tRNA(Ala), tRNA(Asn), tRNA(Cys), tRNA(Tyr), tRNA(Ser(UCN)), tRNA(Pro), and tRNA(Glu)). All the protein-coding genes start with ATG, with the exception of cox1 (cytochrome oxidase subunit 1), which starts with GTG. All tRNA genes have the potential to fold into the typical clover-leaf structure. Conserved sequences in three domains were observed in the two putative control regions. These results provide basic information for future phylogenetic analyses among species of the order Passeriformes.

Involvement of 5-HT3 and 5-HT4 receptors in colonic motor patterns in rats

BACKGROUND

Colonic migrating motor complexes in the rat constitute two distinct propulsive motor patterns, pan-colonic rhythmic long distance contractions (LDCs), and rhythmic propulsive motor complexes (RPMCs) occurring primarily in the mid/distal colon. Interstitial cells of Cajal govern their rhythmicity, but their occurrence is dependent on neural programs. Our aim was to investigate the involvement of 5-HT3 and 5-HT4 receptors in the generation and pharmacological control of the motor patterns.

METHODS

Effects of 5-HT-related drugs on colonic motor patterns were analyzed through spatio-temporal maps created from video recordings of whole organ motility.

KEY RESULTS

5-HT3 antagonists abolished RPMCs and LDCs. 5-HT4 agonists inhibited LDCs; they promoted RPMCs, which was blocked by the 5-HT4 antagonist GR 125487. 5-HT and the 5-HT3 agonist m-CPBG strongly inhibited LDCs and RPMCs.

CONCLUSIONS & INFERENCES

The generation of LDCs involves ongoing 5-HT release acting on 5-HT3 and 5-HT4 receptors. The spontaneous generation of RPMCs involves ongoing 5-HT release acting on 5-HT3 but not 5-HT4 receptors. Prucalopride and mosapride promote RPMCs, an effect that is inhibited by the 5-HT4 receptor antagonist GR 125487. A 5-HT3 agonist does not promote RPMCs. Segmentation, including a pattern of sequential segmental activity not previously described, can occur without significant involvement of 5-HT3 and 5-HT4 receptors. 5-HT and a 5-HT3 agonist are strongly inhibitory indicating that 5-HT receptors are present in inhibitory pathways which are normally not involved in the generation of spontaneous or distention-induced motor patterns.

Two-dimensional Kagome phosphorus and its edge magnetism: a density functional theory study

By means of density functional theory calculations, we predict a new two-dimensional phosphorus allotrope with the Kagome-like lattice(Kagome-P). It is an indirect gap semiconductor with a band gap of 1.64 eV. The gap decreases sensitively with the compressive strain. In particular, shrinking the lattice beyond 13% can drive it into metallic state. In addition, both the AA and AB stacked Kagome-P multi-layer structures exhibit a bandgap much smaller than 1.64 eV. Edges in the Kagome-P monolayer probably suffer from the edge reconstruction. An isolated zigzag edge can induce antiferromagnetic (AF) ordering with a magnetic transition temperature of 23 K. More importantly, when applying a stretching strain beyond 4%, such an edge turns to possess a ferromagnetic ground state. A very narrow zigzag-edged Kagome-P ribbon displays the spin moment distribution similar to the zigzag-edged graphene nanoribbon because of the coupling between the opposites edges. But the inter-edge coupling in the Kagome-P ribbon vanishes more rapidly as the ribbon width increases. These properties make it a promising material in spintronics.

[Clinical analysis of tympanosclerosis: characteristics and treatment]

OBJECTIVE

To explore the clinical characteristics, diagnosis and surgical management of tympanosclerosis.

METHOD

The data of 73 patients who underwent surgery for tympanosclerosis were retrospectively analyzed with respects to the clinical characteristics, diagnosis and management.

RESULT

Seventy-three patients with tympanosclerosis (involving 73 ears) , including 17 patients with sclerosis of tympanic membrane (type I), 23 patients with fixed Malleus-incus complex (type II), 8 (type III) with fixed stapes, and 25 (type IV) with extensive typannosclerosis. Sclerosis was seen most frequently in the malleus, incus and attic, followed by the tympanic membrane, incudomalleolar joint and other regions. Audiometry was performed for all the patients 1 weeks before and 1 year( the least) after operation, which were (51.70 ± 14.93)dB HL and (36.24 ± 11.58) dB HL respectively, with success rate 83% (61/73).

CONCLUSION

Most of the patients suffer from conductive hearing loss. Teatment of the sclerosis around stapes is a key point. Acording to the sites of lesion and hearing level, hearing structures should be reconstructed by the rules of tympanoplasty and stapes surgery.