Optimization of the Zhou Tian Formula extraction technology based on AHP-CRITIC method and analysis of transfer efficiency of key components based on HPLC fingerprinting.

INTRODUCTION: Zhou Tian Formula (ZTF) is an antidepressant traditional Chinese medicine utilized widely in clinical settings for the treatment of patients with depression. However, shortcomings persist in its extraction technology and quality control. OBJECTIVE: This study aimed to propose a methodology for ZTF extraction technology based on the analytic hierarchy process (AHP)-criteria importance through intercriteria correlation (CRITIC) method and to establish a quality control framework for the efficient transfer of index components. METHOD: Firstly, we analyzed the chemical components of ZTF and determined the optimal extraction technology. Secondly, we calculated the transfer efficiency of the index components during the conversion of water decoction to extract powder and subsequently to granules. Thirdly, we established HPLC fingerprints for 15 batches of ZTF water decoction, extract powder, and granules. We employed SIMCA software to analyze the chemicals responsible for variations in quality among different batches of ZTF granules. RESULTS: We determined the optimal extraction process. The average transfer efficiency of ferulic acid, puerarin, mirificin, isoferulic acid, and calycosin during the conversion of water decoction to extract powder and subsequently to granules exceeded 41%. The HPLC fingerprints of ZTF exhibited a similarity exceeding 0.890. Variable importance in projection values indicated that calycosin, ferulic acid, and puerarin were the primary contributors to quality variations. CONCLUSIONS: The AHP-CRITIC method, coupled with an orthogonal array design, could be used for exploring extraction technology. In addition, the rules governing the transfer of index components from water decoction to extract powder, and subsequently to granules, could be applied for the evaluation and quality assessment of ZTF.

Occurrence of liquid crystal monomers in indoor and outdoor air particle matters (PM10): Implications for human exposure indoors.

Liquid crystal monomers (LCMs) are potentially persistent, bioaccumulating, and toxic substances. However, limited data are available on the occurrence of LCMs in indoor and outdoor air particle matter (PM10) in residential areas. Herein, residential areas near an e-waste dismantling center (Guiyu Town, Shantou City), as well as areas away from the e-waste site (Jiedong District, Jieyang City) were selected as the sampling areas. PM10 was collected from the indoor environments of Guiyu (IGY) and Jieyang (IJY), as well as those from the outdoor environments (OGY and OJY) using the high-volume air samplers (TH-10000C). The levels of 57 LCMs in PM10 were analyzed, and the highest concentrations of LCMs were found in IGY (0.970-1080 pg/m3), followed by IJY (2.853-455 pg/m3), OGY (0.544-116 pg/m3) and OJY (0.258-35.8 pg/m3). No significant difference was observed for LCM levels in indoor PM10 between the two areas (p > 0.05), which were significantly higher than those in outdoors (p < 0.05), indicating that the release of electronic products in general indoor environments is a source of LCMs that cannot be ignored. The compositions of LCMs in outdoors were not consistent with those of indoors. The correlation analysis of individual LCMs suggested potential different sources to the LCMs in indoor and outdoor environments. The median daily intake values of Σ46LCMs via inhalation were estimated as 0.440, 1.46 × 10-2, 0.170 and 1.19 × 10-2 ng/kg BW/day for adults, and as 2.27, 2.60 × 10-2, 0.880 and 2.10 × 10-2 ng/kg BW/day for toddlers, respectively, indicating much higher exposure doses of LCMs indoors compared with the outdoors, and much higher doses for toddlers compared with adults (p < 0.05). These results reveal the potentially adverse effects of LCMs on vulnerable populations, such as toddlers, in indoor environments.

Food-grade γ-aminobutyric acid production by immobilized glutamate decarboxylase from Lactobacillus plantarum in rice vinegar and monosodium glutamate system.

OBJECTIVES: γ-amino butyric acid (GABA) is a non-protein amino acid, considered a potent bioactive compound. This study focused on biosynthesis of food-grade GABA by immobilized glutamate decarboxylase (GAD) from Lactobacillus plantarum in the rice vinegar and monosodium glutamate (MSG) reaction system. RESULTS: The gene encoding glutamate decarboxylase (GadB) from L. plantarum has been heterologously expressed in Lactococcus lactis and biochemically characterized. Recombinant GadB existed as a homodimer, and displayed maximal activity at 40 °C and pH 5.0. The Km value and catalytic efficiency (kcat/Km) of GadB for L-Glu was 22.33 mM and 62.4 mM-1 min-1, respectively, with a specific activity of 24.97 U/mg protein. Then, purified GadB was encapsulated in gellan gum beads. Compared to the free enzyme, immobilized GadB showed higher operational and storage stability. Finally, 9.82 to 21.48 g/L of GABA have been acquired by regulating the amounts of catalyst microspheres ranging from 0.5 to 0.8 g (wet weight) in 0.8 mL of the designed rice vinegar and MSG reaction system. CONCLUSIONS: The method of production GABA by immobilized GadB microspheres mixed in the rice vinegar and MSG reaction system is introduced herein for the first time. Especially, the results obtained here meet the increased interest in the harnessing of biocatalyst to synthesize food-grade GABA.

Phosphate regulator PhoP directly and indirectly controls transcription of the erythromycin biosynthesis genes in Saccharopolyspora erythraea.

BACKGROUND: The choice of phosphate/nitrogen source and their concentrations have been shown to have great influences on antibiotic production. However, the underlying mechanisms responsible for this remain poorly understood. RESULTS: We show that nutrient-sensing regulator PhoP (phosphate regulator) binds to and upregulates most of genes (ery cluster genes) involved in erythromycin biosynthesis in Saccharopolyspora erythraea, resulting in increase of erythromycin yield. Furthermore, it was found that PhoP also directly interacted with the promoter region of bldD gene encoding an activator of erythromycin biosynthesis, and induced its transcription. Phosphate limitation and overexpression of phoP increased the transcript levels of ery genes to enhance the erythromycin production. The results are further supported by observation that an over-producing strain of S. erythraea expressed more PhoP than a wild-type strain. On the other hand, nitrogen signal exerts the regulatory effect on the erythromycin biosynthesis through GlnR negatively regulating the transcription of phoP gene. CONCLUSIONS: These findings provide evidence that PhoP mediates the interplay between phosphate/nitrogen metabolism and secondary metabolism by integrating phosphate/nitrogen signals to modulate the erythromycin biosynthesis. Our study reveals a molecular mechanism underlying antibiotic production, and suggests new possibilities for designing metabolic engineering and fermentation optimization strategies for increasing antibiotics yield.

[Comparison of the effect of three nickel-titanium instruments on molar root canal curvature].

PURPOSE: To evaluate the influence of ProTaper, Mtwo, and M3 nickel-titanium instruments on root canal curvature during root canal preparation. METHODS: Forty-five molars with root canal therapy were randomly divided into 3 groups. The root canals were prepared by using ProTaper, Mtwo and M3 nickel-titanium instruments. The qualified rate and change of root canal curvature before and after preparation were compared using SPSS22.0 software package. RESULTS: There was no significant difference between the three groups in the qualification rate after root canal preparation and the effect of different preparatory devices on root canal curvature(P>0.05), but there was significant difference in the change of root canal curvature before and after preparation (P<0.05). CONCLUSIONS: The three kinds of nickel-titanium instruments can effectively form root canal and have no difference in root canal curvature， but the curvature of root canal is changed after preparation. It is important to prevent complications during curved root canal preparation.

[Comparison of clinical efficacy of CAD/CAM all -ceramic inlay and polymerid porcelain inlay in restoration of posterior Class II cavity].

PURPOSE: To compare the clinical efficacy of CAD/CAM all-ceramic inlay and polymerid porcelain inlay in restoring Class II cavity of posterior teeth. METHODS: Ninety-seven patients with 100 posterior teeth of ClassII cavity were recruited in this randomized control trial; Among them, 50 patients were grouped into CAD/CAM all-ceramic inlays and 47 patients were grouped into Ceramage polymerid porcelain inlay. According to the modified USPHS criteria, the incidence of postoperative sensitivity, prosthesis fracture, prosthesis falling off, and edge coloration were evaluated 12 months and 24 months after restoration. Chi-square test and Wilcoxon rank sum test were used for statistical analysis using SPSS 13.0 software package. RESULTS: Restoration in the 2 groups were successful, there was no significant difference at 12 months (P>0.05). Postoperative sensitivity and the incidence of prosthesis falling off in both groups were not significantly different (P>0.05); however, the number of prosthesis fracture of the polymerid porcelain was lower than that of the CAD/CAM all-ceramic inlays (P<0.05). The incidence of edge coloration of CAD/CAM all-ceramic inlays was lower than that of the polymerid porcelain at 24-month follow-up (P<0.05). CONCLUSIONS: Restoration with polymerid porcelain is more likely to have a higher success rate than those with CAD/CAM all-ceramic inlays. Patients undergoing CAD/CAM all-ceramic inlays have a lower incidence of edge coloration, compared with those undergoing polymerid porcelain.

[Influence of age on the effectiveness of revascularization in immature permanent teeth].

PURPOSE: To evaluate the effect of age on the potential of dental pulp regeneration in young permanent teeth with periapical periodontitis. METHODS: A total of 30 mandibular premolars from 9-18 years old patients with pulp necrosis were divided into 2 groups, group A (younger age group): 9-13 years old, and group B (older age group): 14-18 years old. Revascularization procedures were performed for all patients. Follow-up was done for up to 18 months. Standardized radiographs of cone-beam CT (CBCT) were digitally evaluated for increase in root length and thickness. The data were analyzed by nonparametric two sample rank sum test using SPSS13.0 software package. RESULTS: After 18 months of follow-up, the clinical symptoms of the two groups disappeared. The cure rate of group A was significantly higher than that of group B (P=0.003). Radiographic analysis showed that the root length and root canal wall thickness in group A was significantly greater than those in group B (P<0.05). CONCLUSIONS: Root canal revascularization can be widely used in the treatment of dental pulp necrosis in young permanent teeth. The closer the age is to the eruption time, the higher the potential of dental pulp regeneration, and the more suitable for root canal revascularization.

GlnR and PhoP Directly Regulate the Transcription of Genes Encoding Starch-Degrading, Amylolytic Enzymes in Saccharopolyspora erythraea.

Starch-degrading enzymes hydrolyze starch- and starch-derived oligosaccharides to yield glucose. We investigated the transcriptional regulation of genes encoding starch-degrading enzymes in the industrial actinobacterium Saccharopolyspora erythraea We observed that most genes encoding amylolytic enzymes (one α-amylase, one glucoamylase, and four α-glucosidases) were regulated by GlnR and PhoP, which are global regulators of nitrogen and phosphate metabolism, respectively. Electrophoretic mobility shift assays and reverse transcription-PCR (RT-PCR) analyses demonstrated that GlnR and PhoP directly interact with their promoter regions and collaboratively or competitively activate their transcription. Deletion of glnR caused poor growth on starch, maltodextrin, and maltose, whereas overexpression of glnR and phoP increased the total activity of α-glucosidase, resulting in enhanced carbohydrate utilization. Additionally, transcript levels of amylolytic genes and total glucosidase activity were induced in response to nitrogen and phosphate limitation. Furthermore, regulatory effects of GlnR and PhoP on starch-degrading enzymes were conserved in Streptomyces coelicolor A3(2). These results demonstrate that GlnR and PhoP are involved in polysaccharide degradation by mediating the interplay among carbon, nitrogen, and phosphate metabolism in response to cellular nutritional states. Our study reveals a novel regulatory mechanism underlying carbohydrate metabolism, and suggests new possibilities for designing genetic engineering approaches to improve the rate of utilization of starch in actinobacteria.IMPORTANCE The development of efficient strategies for utilization of biomass-derived sugars, such as starch and cellulose, remains a major technical challenge due to the weak activity of associated enzymes. Here, we found that GlnR and PhoP directly regulate the transcription of genes encoding amylolytic enzymes and present insights into the regulatory mechanisms of degradation and utilization of starch in actinobacteria. Two nutrient-sensing regulators may play important roles in creating a direct association between nitrogen/phosphate metabolisms and carbohydrate utilization, as well as modulate the C:N:P balance in response to cellular nutritional states. These findings highlight the interesting possibilities for designing genetic engineering approaches and optimizing the fermentation process to improve the utilization efficiency of sugars in actinobacteria via overexpression of the glnR and phoP genes and nutrient signal stimulation.

Reciprocal Regulation of GlnR and PhoP in Response to Nitrogen and Phosphate Limitations in Saccharopolyspora erythraea.

Nitrogen and phosphate source sensing, uptake, and assimilation are essential for the growth and development of microorganisms. In this study, we demonstrated that SACE_6965 encodes the phosphate regulator PhoP, which controls the transcription of genes involved in phosphate metabolism in the erythromycin-producing Saccharopolyspora erythraea. We found that PhoP and the nitrogen regulator GlnR both regulate the transcription of glnR as well as other nitrogen metabolism-related genes. Interestingly, both GlnR- and PhoP-binding sites were identified in the phoP promoter region. Unlike the nonreciprocal regulation of GlnR and PhoP observed in Streptomyces coelicolor and Streptomyces lividans, GlnR negatively controls the transcription of the phoP gene in S. erythraea. This suggests that GlnR directly affects phosphate metabolism and demonstrates that the cross talk between GlnR and PhoP is reciprocal. Although GlnR and PhoP sites in the glnR and phoP promoter regions are located in close proximity to one another (separated by only 2 to 4 bp), the binding of both regulators to their respective region was independent and noninterfering. These results indicate that two regulators could separately bind to their respective binding sites and control nitrogen and phosphate metabolism in response to environmental changes. The reciprocal cross talk observed between GlnR and PhoP serves as a foundation for understanding the regulation of complex primary and secondary metabolism in antibiotic-producing actinomycetes.

[Preparation and identification of polyclonal antibody against small peptides of beta-tubulin of Toxoplasma gondii].

The amino acid sequences of beta-tubulin from Toxoplasma gondii stains (GT1 and ME49) and human were aligned by ClustalW2 software. Based on the alignment result, the C-terminal peptides of beta-tubulin of T. gondii were artificially synthesized. Rabbits were immunized with 0.5 mg synthesized peptides for five times at 2-week intervals. Serum samples were collected at the second week after the final immunization, and were analyzed for specific antibodies by ELISA. Finally, the specific-beta-tubulin polyclonal antibody was evaluated by Western blotting with the total protein of RH strain, ME49 strain, and PRU strain of T. gondii, respectively. The results showed that beta-tubulin of T. gondii stains (GT1 and ME49) shared 100% amino-acid sequence identity, and there was 98% amino acid homology between T. gondii and human. The main variable region was the C-terminus. After the fifth immunization, the titers of polyclonal antibody reached 1 : 52,800. Western blotting result indicated that the specific-beta-tubulin polyclonal antibody reacted with beta-tubulin in all the three strains (RH, ME49, and PRU), respectively.

Three genes encoding citrate synthases in Saccharopolyspora erythraea are regulated by the global nutrient-sensing regulators GlnR, DasR, and CRP.

Saccharopolyspora erythraea has three citrate synthases encoded by gltA-2, citA, and citA4. Here, we characterized and identified the expression and regulatory properties of these synthases. Three pleiotropic global regulatory proteins of S. erythraea - CRP, GlnR, and DasR - are involved in carbon metabolism, nitrogen metabolism, and amino-sugar (chitin and GlcNAc) metabolism. Using electrophoretic mobility shift assays (EMSAs), we identified these regulators as proteins that bind directly to the promoter regions of all citrate synthase genes (gltA-2, citA, and citA4). Footprinting assays indicated the exact protect sequences of CRP, GlnR, and DasR on the promoter region of gltA-2, revealing binding competition between GlnR and DasR. Moreover, by comparing the transcription levels of citrate synthase genes between parental and glnR mutant or dasR mutant strains, or by comparing the transcription response of citrate synthases under various nutrient conditions, we found that GlnR and DasR negatively regulated citA and citA4 transcription but had no regulatory effects on the gltA-2 gene. Although no CRP mutant was available, the results indicated that CRP was a cAMP-binding receptor affecting gltA-2 transcription when the intracellular cAMP concentration increased. Thus, an overall model of CS regulation by C and/or N metabolism regulators and cAMP receptor protein was proposed.

GlnR-mediated regulation of nitrogen metabolism in the actinomycete Saccharopolyspora erythraea.

Nitrogen source sensing, uptake, and assimilation are central for growth and development of microorganisms which requires the participation of a global control of nitrogen metabolism-associated genes at the transcriptional level. In soil-dwelling antibiotic-producing actinomycetes, this role is played by GlnR, an OmpR family regulator. In this work, we demonstrate that SACE_7101 is the ortholog of actinomycetes' GlnR global regulators in the erythromycin producer Saccharopolyspora erythraea. Indeed, the chromosomal deletion of SACE_7101 severely affects the viability of S. erythraea when inoculated in minimal media supplemented with NaNO3, NaNO2, NH4Cl, glutamine, or glutamate as sole nitrogen source. Combination of in silico prediction of cis-acting elements, subsequent in vitro (through gel shift assays) and in vivo (real-time reverse transcription polymerase chain reaction) validations of the predicted target genes revealed a very large GlnR regulon aimed at adapting the nitrogen metabolism of S. erythraea. Indeed, enzymes/proteins involved in (i) uptake and assimilation of ammonium, (ii) transport and utilization of urea, (iii) nitrite/nitrate, (iv) glutamate/glutamine, (v) arginine metabolism, (vi) nitric oxide biosynthesis, and (vii) signal transduction associated with the nitrogen source supplied have at least one paralog gene which expression is controlled by GlnR. Our work highlights a GlnR-binding site consensus sequence (t/gna/cAC-n6-GaAAc) which is similar although not identical to the consensus sequences proposed for other actinomycetes. Finally, we discuss the distinct and common features of the GlnR-mediated transcriptional control of nitrogen metabolism between S. erythraea and the model organism Streptomyces coelicolor.

Acetyl coenzyme A synthetase is acetylated on multiple lysine residues by a protein acetyltransferase with a single Gcn5-type N-acetyltransferase (GNAT) domain in Saccharopolyspora erythraea.

Reversible lysine acetylation (RLA) is used by cells of all domains of life to modulate protein function. To date, bacterial acetylation/deacetylation systems have been studied in a few bacteria (e.g., Salmonella enterica, Bacillus subtilis, Escherichia coli, Erwinia amylovora, Mycobacterium tuberculosis, and Geobacillus kaustophilus), but little is known about RLA in antibiotic-producing actinomycetes. Here, we identify the Gcn5-like protein acetyltransferase AcuA of Saccharopolyspora erythraea (SacAcuA, SACE_5148) as the enzyme responsible for the acetylation of the AMP-forming acetyl coenzyme A synthetase (SacAcsA, SACE_2375). Acetylated SacAcsA was deacetylated by a sirtuin-type NAD(+)-dependent consuming deacetylase (SacSrtN, SACE_3798). In vitro acetylation/deacetylation of SacAcsA enzyme was studied by Western blotting, and acetylation of lysine residues Lys(237), Lys(380), Lys(611), and Lys(628) was confirmed by mass spectrometry. In a strain devoid of SacAcuA, none of the above-mentioned Lys residues of SacAcsA was acetylated. To our knowledge, the ability of SacAcuA to acetylate multiple Lys residues is unique among AcuA-type acetyltransferases. Results from site-specific mutagenesis experiments showed that the activity of SacAcsA was controlled by lysine acetylation. Lastly, immunoprecipitation data showed that in vivo acetylation of SacAcsA was influenced by glucose and acetate availability. These results suggested that reversible acetylation may also be a conserved regulatory posttranslational modification strategy in antibiotic-producing actinomycetes.

Prediction and characterization of small non-coding RNAs related to secondary metabolites in Saccharopolyspora erythraea.

Saccharopolyspora erythraea produces a large number of secondary metabolites with biological activities, including erythromycin. Elucidation of the mechanisms through which the production of these secondary metabolites is regulated may help to identify new strategies for improved biosynthesis of erythromycin. In this paper, we describe the systematic prediction and analysis of small non-coding RNAs (sRNAs) in S. erythraea, with the aim to elucidate sRNA-mediated regulation of secondary metabolite biosynthesis. In silico and deep-sequencing technologies were applied to predict sRNAs in S. erythraea. Six hundred and forty-seven potential sRNA loci were identified, of which 382 cis-encoded antisense RNA are complementary to protein-coding regions and 265 predicted transcripts are located in intergenic regions. Six candidate sRNAs (sernc292, sernc293, sernc350, sernc351, sernc361, and sernc389) belong to four gene clusters (tpc3, pke, pks6, and nrps5) that are involved in secondary metabolite biosynthesis. Deep-sequencing data showed that the expression of all sRNAs in the strain HL3168 E3 (E3) was higher than that in NRRL23338 (M), except for sernc292 and sernc361 expression. The relative expression of six sRNAs in strain M and E3 were validated by qRT-PCR at three different time points (24, 48, and 72 h). The results showed that, at each time point, the transcription levels of sernc293, sernc350, sernc351, and sernc389 were higher in E3 than in M, with the largest difference observed at 72 h, whereas no signals for sernc292 and sernc361 were detected. sernc293, sernc350, sernc351, and sernc389 probably regulate iron transport, terpene metabolism, geosmin synthesis, and polyketide biosynthesis, respectively. The major significance of this study is the successful prediction and identification of sRNAs in genomic regions close to the secondary metabolism-related genes in S. erythraea. A better understanding of the sRNA-target interaction would help to elucidate the complete range of functions of sRNAs in S. erythraea, including sRNA-mediated regulation of erythromycin biosynthesis.

Development-specific differences in the proteomics of Angiostrongylus cantonensis.

Angiostrongyliasis is an emerging communicable disease. Several different hosts are required to complete the life cycle of Angiostrongylus cantonensis. However, we lack a complete understanding of variability of proteins across different developmental stages and their contribution to parasite survival and progression. In this study, we extracted soluble proteins from various stages of the A. cantonensis life cycle [female adults, male adults, the fifth-stage female larvae (FL5), the fifth-stage male larvae (ML5) and third-stage larvae (L3)], separated those proteins using two-dimensional difference gel electrophoresis (2D-DIGE) at pH 4-7, and analyzed the gel images using DeCyder 7.0 software. This proteomic analysis produced a total of 183 different dominant protein spots. Thirty-seven protein spots were found to have high confidence scores (>95%) by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Comparative proteomic analyses revealed that 29 spots represented cytoskeleton-associated proteins and functional proteins. Eight spots were unnamed proteins. Twelve protein spots that were matched to the EST of different-stage larvae of A. cantonensis were identified. Two genes and the internal control 18s were chosen for quantitative real-time PCR (qPCR) and the qPCR results were consistent with those of the DIGE studies. These findings will provide a new basis for understanding the characteristics of growth and development of A. cantonensis and the host-parasite relationship. They may also assist searches for candidate proteins suitable for use in diagnostic assays and as drug targets for the control of eosinophilic meningitis caused by A. cantonensis.

[Crystal structure and upconversion emission of Yb3+/Er(3+) -co-doped NaYF4 nanocrystals].

Yb3+/EP(3+) -co-doped cubic NaYF4 and Yb3+/Er3+/Gd(3+) -tri-doped hexagonal NaYF4 nanocrystals were synthesized by a modified coprecipitation method with ethylenediamine tetraacetic acid (EDTA) as chelating agent. The samples' morphology, crystal phase and upconversion emission were measured with transmission electron microscope (TEM), X-ray diffraction patterns (XRD) and upconversion luminescence spectrum. TEM and XRD results showed that the phase transition from cubic to hexagonal was promoted through Gd3+ doping. It has been reported that the upconversion efficiency of hexagonal NaYF4 is higher than that of cubic NaYF4, however, the effect of crystal phase on upconversion luminescence has not been well understood. This work focuses analysis of measurement results to compare the effect of, crystal phase on the crystal field energy splitting and upconversion emission intensity as well as emission color, and a mechanism of luminescence enhancement and color tunability are revealed. Strong visible upconversion luminescence can be seen clearly by the naked eyes in both cubic phase and hexagonal phase samples upon excitation by a 980 nm laser diode with power of 10 mW, consisting of green emissions centered at around 525/550 nm originating from the transitions of 2H11/2/4 S3/2 --> 4 I15/2 and red emission at about 657 nm from 4F9/2 to 4 I15/2 of Er3+ ions respectively. In comparison to cubic sample, the hexagonal phase sample presented much stronger and sharper upconversion luminescence, whose emission efficiency was enhanced 10 times with an additional transition of 2 H9/2 --> 4I13/2 at 557 nm, furthermore, the intensity ratio of red to green emission increased from 2 :1 to 3 : 1. Doping NaYF4 nanocrystals with Gd3+ ions induced the hexagonal-to-cubic phase transition and thus decreased the crystal symmetry, consequently increased absorption cross-section and 4f-4f transition probabilities by relaxing forbidden selection rules, resulting in stronger emission. In the mean time, the decreasing unit-cell volume of the hexagonal phase increased the crystal field strength around the dopant ions and consequently led to that hexagonal phase samples present much sharper emission compared to cubic counterparts. It demonstrates that phase transition can tune crystal field energy splitting, luminescence intensity and emission color.

Multiple quantitative trait loci Haseman-Elston regression using all markers on the entire genome.

The Haseman-Elston (HE) regression, developed in the 1970s, remains in common use to detect genetic linkage between a quantitative trait and a genetic marker. Although the technique has been improved in a number of ways, it predicts a high rate of false positive quantitative trait locus (QTL) because it is based on a single-QTL model. We have extended the origin HE regression to multi-QTL HE (MQHE) regression, so that all markers across the entire genome can be exploited simultaneously. The parameters have been estimated by the penalized maximum likelihood method, and several response variables for phenotypic difference have been compared in order to optimize the procedure. The method has been tested by simulation in a pedigree population of maize inbred lines of known ancestry. These simulations show that the trait product is the optimal response variable for phenotypic difference. The false positive rate produced by the MQHE regression is substantially lower than that generated by either variance component analysis or the origin HE regression. The MQHE regression, with the trait product as the response variable, represents a significant improvement on existing methods for QTL mapping in a set of inbred lines (or cultivars) of known ancestry.

[Evaluation of the use of dental operating microscope in the management of blocked canals].

PURPOSE: This study was performed to evaluate the value of dental operating microscope(DOM) in treating blocked canals. METHODS: 161 blocked canals in 113 teeth were treated with ultrasonic instruments under DOM. The etiology of canal blockage included calcification, resinifying therapy and broken instruments. All canals were grouped based on the cause of blockage, teeth site and blockage location in canals, and then the success rates of negotiating ,using SPSS10.0 software package, were analyzed with X(2) test. RESULTS: The results showed that 131 canals were negotiated with a success rate of 81.37%.Blocked canals caused by calcification, resinifying therapy and broken instruments were managed with the success rate of 84.27%, 81.58% and 73.53%, respectively.There were no significant differences in the success rate(P>0.05). Blocked canals of anterior were managed successfully with a success rate of 93.48%,canals of premolar with a success rate of 84.61%,and canals of molar with a success rate of 72.37%. There were significant differences in the success rate between anterior and molar teeth(P<0.01).When the blockage was located in straight canals or above the root canal curvature,canals were negotiated with a success rate of 93.98>.However,the success rate decreased to 21.42> when the blockage located below the root canal curvature,and significant differences were found(P<0.01). CONCLUSIONS: It is an effective way to use dental operating microscope to treat blocked canals, but the therapeutic effects might be affected by sites of the teeth and the blockage location in canals.

[Evaluation of the clinical effect of the teeth with subgingivally involved defect conserved by crown lengthening surgery].

PURPOSE: To evaluate the clinical effect of the teeth with subgingivally involved defect which were conserved by crown lengthening surgery. METHODS: 62 teeth, with defect subgingivally from 1.5 mm to 4 mm, mobility degree(MD)0.05), but a significant increase about MD occurred in the major defect group one year after restoration (P<0.01), and there was significant correlation between MD of each stage after operation and PD of pre-operation in anterior teeth (r=0.489, 0.526, 0.531, P<0.01). CONCLUSIONS: According to the biological width principle, crown lengthening surgery may conserve these teeth with subgingivally involved defect, and has a good, long-time clinical effect. But MD showed an increasing trend after operation and significant cor.