Sun-like light source design considering non-visual performance to improve working efficiency.

With the discovery of intrinsically photosensitive retinal ganglion cells, we have a better understanding of the non-visual effects of lighting. In this study, the optimum spectral power distribution in sunlight of different color temperatures is calculated by MATLAB software. At the same time, the ratio of the non-visual effect and visual effect (K e,α ) at different color temperatures is calculated according to the sunlight spectrum to evaluate the non-visual and visual effects of white LEDs at the corresponding color temperature. Then based on the characteristics of monochromatic LED spectra, the joint-density-of-states model is used as a mathematical model, and the optimal solution is calculated for its database. According to the calculated combination scheme, Light Tools software is used to optimize and simulate the expected light source parameters. The final color temperature is 7525 K, the color coordinate is (0.2959, 0.3255), and the color rendering index reaches 92. The high efficiency light source has not only the function of lighting, but also the effect of improving work efficiency with lower blue light hazard efficiency of radiation than normal LEDs.

Identification of downstream target genes regulated by CX43 in hepatocellular carcinoma.

The aim of study was to identify the downstream target genes of CX43 by Human Transcriptome Array. Therefore, a gene microarray was generated which consists of CX43-overexpressed hepatocellular carcinoma (HCC) cells transfected with the constructed plasmid and negative controls to identify candidate genes. Integrated bioinformatic analysis was used to clarify biological functions of the identified genes, including Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, protein-protein interaction network, and survival analysis. The candidate genes were further validated by qRT-PCR in liver cancer tissues and CX43-silenced HCC cells. We have found the mRNA and protein levels of CX43 significantly upregulated in HCC cells transfected with CX43 constructed plasmid. We identified 928 differentially expressed genes including 394 upregulated and 534 downregulated genes, enriched in the cancer related functions and pathways by GO and KEGG pathway analysis. The protein-protein interaction network revealed 9 hub genes in this study. Statistical analysis indicated that upregulation of RALA and SRC was associated with poor prognosis in liver cancer. The differential expression of 2 candidate genes were further validated in HCC cells and tissues. In conclusion, protein-coding genes RALA and SRC could be target genes of CX43 and therapeutic targets for hepatocellular carcinoma.

Characterization of Pd/Y multilayers with B4C barrier layers using GIXR and X-ray standing wave enhanced HAXPES.

Pd/Y multilayers are high-reflectance mirrors designed to work in the 7.5-11 nm wavelength range. Samples, prepared by magnetron sputtering, are deposited with or without B4C barrier layers located at the interfaces of the Pd and Y layers to reduce interdiffusion, which is expected from calculating the mixing enthalpy of Pd and Y. Grazing-incident X-ray reflectometry is used to characterize these multilayers. B4C barrier layers are found to be effective in reducing Pd-Y interdiffusion. Details of the composition of the multilayers are revealed by hard X-ray photoemission spectroscopy with X-ray standing wave effects. This consists of measuring the photoemission intensity from the samples by performing an angular scan in the region corresponding to the multilayer period and an incident photon energy according to Bragg's law. The experimental results indicate that Pd does not chemically react with B nor C at the Pd-B4C interface while Y does react at the Y-B4C interface. The formation of Y-B or Y-C chemical compounds could be the reason why the interfaces are stabilized. By comparing the experimentally obtained angular variation of the characteristic photoemission with theoretical calculations, the depth distribution of each component element can be interpreted.

[The expression and prognostic significance of microRNA-34a in Uygur and Han patients with chronic lymphocytic leukemia in Xinjiang Uygur Autonomous Region in China].

To investigate the expression of microRNA-34a (miR-34a) in patients with chronic lymphocytic leukemia (CLL) in Xinjiang Uygur and Han nationalities and its prognostic significance. Our data showed that miR-34a expression in Uygur and Han CLL patients was significantly higher than that in their respective healthy controls, while miR-34a levels were similar between Uygur and Han patients. By comparing with known prognostic factors, receiver operating characteristic (ROC) curves showed that miR-34a was a good predictive factor for the prognosis of CLL (demarcation value was 3.567 6). Survival analysis was further performed according to miR-34a expression level, that low expression of miR-34a translated into poor prognosis.

Effect of different levels of protein concentrates supplementation on the growth performance, plasma amino acids profile and mTOR cascade genes expression in early-weaned yak calves.

OBJECTIVE: This study evaluated the effects of different levels of protein concentrate supplementation on the growth performance of yak calves, and correlated the growth rate to changes occurring in the plasma- amino acids, -insulin profile, and signaling activity of mammalian target of rapamycin (mTOR) cascade to characterize the mechanism through which the protein synthesis can be improved in early weaned yaks. METHODS: For this study, 48 early (3 months old) weaned yak calves were selected, and assigned into four dietary treatments according to randomized complete block design. The four blocks were balanced for body weight and sex. The yaks were either grazed on natural pasture (control diet) in a single herd or the grazing yaks was supplemented with one of the three protein rich supplements containing low (17%; LP), medium (19%; MP), or high (21%; HP) levels of crude proteins for a period of 30 days. RESULTS: Results showed that the average daily gain of calves increased (0.14 vs 0.23-0.26 kg; p<0.05) with protein concentrates supplementation. The concentration of plasma methionine increased (p<0.05; 8.6 vs 10.1-12.4 µmol/L), while those of serine and tyrosine did not change (p>0.05) when the grazing calves were supplemented with protein concentrates. Compared to control diet, the insulin level of calves increased (p<0.05; 1.86 vs 2.16-2.54 µIU/mL) with supplementation of protein concentrates. Addition of protein concentrates up-regulated (p<0.05) expression of mTOR-raptor, mammalian vacuolar protein sorting 34 homolog, the translational regulators eukaryotic translation initiation factor 4E binding protein 1, and S6 kinase 1 genes in both Longissimus dorsi and semitendinosus. In contrast, the expression of sequestosome 1 was down-regulated in the concentrate supplemented calves. CONCLUSION: Our results show that protein supplementation improves the growth performance of early weaned yak calves, and that plasma methionine and insulin concentrations were the key mediator for gene expression and protein deposition in the muscles.

[Clinicopathologic features of hepatocellular carcinoma patients surviving more than 10 years after radical hepatectomy].

Objective: To clarify the clinicopathologic features of hepatocellular carcinoma (HCC) patients survived more than 10 years after radical hepatectomy. Methods: Two hundreds and fifty-two patients who underwent curative resection for HCC between January 1999 and March 2006 at Department of Hepatopancreatobiliary Surgery, Affiliated Hospital of Qingdao University were included.There were 217 male cases and 35 female cases aging from 17 to 82 years with median age of (53.8±10.5)years. Followed by March 31 2016, clinicopathologic factors in 10-year survivors and patients who died within 10 years were compared by χ(2) test, Kaplan-Meier survival analysis and Cox proportional hazards model and the prognostic factors affecting survival were identified. Results: All patients were followed-up for 4.0 to 205.7 months with median time of 53.4 months. The 10-year overall survival rate was 26%, there were 62 cases(26.2%) who survived for more than 10 years after initial hepatectomy. In survival >10-year group, the paitents with ALT<40 U/L, gamma-glutamyl transpeptidase<64 U/L, albumin≥35 g/L, without liver cirrhosis and portal hypertension, Child-Pugh grade A, no blood transfusion, AFP≤20 µg/L, tumor size ≤5.0 cm, single tumor, high differentiation, TNM stage Ⅰ and TACE negative after resection were more than the patients in survival <10-year group (P<0.05). In multivariate analysis, Child-Pugh grade A, the tumor size ≤5.0 cm and TACE negative after resection were favorable independent factors associated with 10-year survival (P<0.05). Conclusion: Based on the results of the study, Child-Pugh grade A, tumor size ≤5.0 cm and TACE negative after resection at initial hepatectomy might be biologically favorable conditions for patients surviving more than 10 years.

Development and characterization of microsatellite markers for Ulmus chenmoui (Ulmaceae), an endangered tree endemic to eastern China.

Ulmus chenmoui (Ulmaceae) is an endangered tree found on Langya Mountain, eastern China. To better understand the population genetics of U. chenmoui and conserve the species, we developed microsatellite markers. Using a suppression-polymerase chain reaction technique, 74 compound microsatellite primer pairs were designed. Twelve microsatellite markers were polymorphic in 39 individuals, and the number of alleles per locus ranged from 3 to 9. The observed and expected heterozygosities ranged from 0.051 to 0.769 and from 0.533 to 0.768, respectively. Significant linkage disequilibrium was detected for three pairs of loci (P < 0.01), which may be due to a recent population bottleneck and the small population size. Nine of the 12 loci deviated from the Hardy-Weinberg equilibrium (P < 0.01), which could be explained by significant inbreeding rather than the presence of null alleles. These markers will provide a solid basis for future efforts in population genetic studies of U. chenmoui, which in turn will contribute to species conservation.

Consistency between molecular phylogeny and morphological classification of the Salix matsudana Koidz. complex (Salicaceae).

The morphological species concept is based on morpho-logical traits, which are often subject to subjectivity or artifact. Molecular evidence is needed to test the reliability of morphological classification of taxa that are controversial and to provide appropriate taxonomic de-limitation. In this study, we used 15 single-copy nuclear loci and 2 chloroplast fragments to verify the morphological classification of the Salix matsudana Koidz. complex using phylogenetic approaches. Complete sequence alignment showed slight diversification in nuclear sequences and no variety in chloroplast DNA fragments. Phylogenetic trees revealed a monophyletic group consisting of all individuals of S. matsudana and 2 clades within this group, with a 100% bootstrap support value and 1.00 posterior probability. The topology of the phylogenetic trees was highly consistent with the morphological classification of the S. matsudana complex. Verifying the genetic background of these classification units based on remarkable morphological differences will provide a foundation for future studies of Salix and the breeding of new horticultural varieties.

Isolation and characterization of microsatellite loci for Cunninghamia lanceolata (Lamb.) Hook.

As a result of human activities, wild populations of Cunninghamia lanceolata (Cupressaceae) have sharply declined in recent years. The development and implementation of a valid conservation strategy require a clear understanding of the genetic makeup of this species. Eleven polymorphic microsatellite loci were isolated and characterized from samples of 52 individuals from the Provenance Test Plantation in Fenyi, Jiangxi Province, China. Among the loci, 10 were polymorphic and 1-34 (average 18.182) alleles per locus were identified. Observed and expected heterozygosities ranged from 0 to 0.750 (mean 0.456) and 0 to 0.968 (mean 0.749), respectively. These microsatellite loci may facilitate further research on the molecular breeding and population genetics of C. lanceolata and its relatives.

-173G/C polymorphism in the promoter of MIF is associated with hepatitis B virus infection in a Chinese Han population.

In addition to the host immune response, genetic and environmental factors play crucial roles in the manifestation of hepatitis B virus (HBV) infection. The macrophage migration inhibitory factor (MIF) -173G/C polymorphism (rs755622), located in the promoter region of MIF, may play integral roles in diverse processes, including the immune response. Thus, the MIF -173G/C polymorphism may influence the immune response to HBV during natural infection. We investigated whether the MIF -173G/C polymorphism was associated with susceptibility to HBV infection in a Chinese Han population. A total of 596 HBV infection cases and 612 age-matched controls were recruited for the study. Genotyping of the MIF -173G/C polymorphism was performed using the allele-specific polymerase chain reaction method. The frequencies of the alleles and genotypes in patients and controls were compared using the χ(2) test. Carriers of the variant C allele in MIF -173 G/C were at significantly higher risk of HBV infection than carriers of the wild-type allele (P = 0.032, odds ratio = 0.799, 95% confidence interval = 0.651-0.981). However, there was no significant difference in the distribution of MIF -173G/C genotypes between case and control groups in either population (P = 0.096, degrees of freedom = 2). Our findings indicate that the G to C base change in MIF -173 G/C confers an increased risk of development of HBV infection by altering the expression of MIF in our Chinese Han population.

CYP2C9 polymorphism analysis in Han Chinese populations: building the largest allele frequency database.

Genetic polymorphisms of CYP2C9 significantly influence the pharmacokinetics and pharmacodynamics of some drugs, which might result in adverse drug effects and therapeutic failure. Several studies have been performed on CYP2C9 genetic polymorphisms in Han Chinese populations. However, these studies only focused on two commonly investigated alleles, *2 and *3, in relatively small sample sizes. To scale up the gene-scanning region and determine relatively precise data on the genetic distribution pattern in Chinese populations, unrelated healthy Han Chinese volunteers from Zhejiang Province (n=1127) and Hebei (n=1000) Province were recruited as subjects for the direct sequencing of all exons of CYP2C9. As a result, 14 previously reported alleles were detected in this work, and 8 of these alleles (*14, *16, *19, *23, *27, *29, *33 and *34) were described for the first time in Chinese populations. In addition, 37 novel mutations were also detected, of which 22 variants were non-synonymous, and 21 new alleles, *36-*56, were designated by the Human CYP Allele Nomenclature Committee. In vitro functional analysis of these 22 novel CYP2C9 variants revealed that 17 mutations had a significant influence on the protein's catalytic activity. Our study provides the most accurate data on CYP2C9 polymorphisms in Han Chinese populations and detects the largest number of novel allelic variants existing to date. These new alleles will greatly enrich the current knowledge of naturally occurring CYP2C9 variants in Chinese populations.

A novel set of single-copy nuclear DNA markers for the genetic study of Salicaceae.

Species of Populus are widely distributed worldwide, playing a significant role in both ecology and economy. However, the lack of single-copy nuclear markers limits knowledge about the phylogeny and population genetics of this genus. In the present study, primer pairs of 15 single-copy nuclear markers were developed through bioinformatic methods based on complete genomic sequences of Populus trichocarpa and Salix arbutifolia. Twenty individuals of Populus davidiana Dode and Salix matsudana Koidz were used to evaluate the basic application of these markers with respect to marker length and diversity indices, respectively. The utility of single-copy nuclear markers is anticipated to facilitate further studies about the phylogeny, population genetics, and phylogeography of this genus, in addition to providing information about the evolutionary dynamics of Salicaceae.

[Isolation and characterization of normal mandibular periosteal stem cells from human and macaca mulatta and cross-species single-cell analysis].

Objective: To investigate the presence of a distinct stem cell populations different from mesenchymal stem cells in the mandibular periosteum of both human and non-human primates (macaca mulatta), to explore its properties during intramembranous osteogenesis and to establish standard protocols for the isolation, culturing and expanding of mandibular periosteal stem cells (PSCs) distinguished from other PSCs in other anatomical regions. Methods: Periosteum was harvested from the bone surface during flap bone removal in patients aged 18-24 years undergoing third molar extraction and from the buccal side of the mandibular premolar region of 1-year-old macaca mulatta respectively, and then subjected to single-cell sequencing using the Illumina platform Novaseq 6000 sequencer. Cross-species single-cell transcriptome sequencing results were compared using homologous gene matching. PSCs were isolated from primary tissues using two digestion methods with body temperature and low temperature, and their surface markers (CD200, CD31, CD45 and CD90) were identified by cell flow cytometry. Then, the ability of cell proliferation and three-lineage differentiation of PSCs expanded to the third generation in vitro in different species were evaluated. Finally, the similarities and differences in osteogenic properties of periosteal stem cells and bone marrow mesenchymal stem cells were compared. Results: The single-cell sequencing results indicated that 18 clusters of cell populations were identified after homologous gene matching for dimensionality reduction, and manual cellular annotation was conducted for each cluster based on cell marker databases. The comparison of different digestion protocols proved that the low-temperature overnight digestion protocol can stably isolate periosteal stem cells from the human and m. mulatta mandibular periosteum and the cells exhibited a fibroblast-like morphology. This research confirmed that periosteal stem cells of human and m. mulatta had similar proliferation capabilities through the cell counting kit-8 assay. Flow cytometry analysis was then used to identify the cells isolated from the periosteum expressed CD200(+), CD31(-), CD45(-), CD90(-). Then, human and m. mulatta periosteal stem cells were induced into osteogenesis, adipogenesis, and chondrogenesis to demonstrate their corresponding multi-lineage differentiation capabilities. Finally, comparison with bone marrow mesenchymal stem cells further clarified the oesteogenesis characteristics of periosteal stem cells. The above experiments proved that the cells isolated from the periosteum were peiosteal cells with characteristics of stem cells evidenced by their cell morphology, proliferation ability, surface markers, and differentiation ability, and that this group of periosteal stem cells possessed characteristics different from traditional mesenchymal stem cells. Conclusions: In this study, normal mandibular periosteal stem cells from humans and m. mulatta were stably isolated and identified for the first time, providing a cellular foundation for investigating the mechanism of mandibular intramembranous osteogenesis, exploring ideal non-human primate models and establishing innovative strategies for clinically mandibular injury repair.

First Report of Bacterial Leaf Spot Disease Caused by Pseudomonas syringae pv. syringae on Panax notoginseng.

Panax notoginseng is a species that produces a rare type of Chinese herbal medicine and is cultivated primarily in Yunnan Province. P. notoginseng has a 3-year-long crop cycle before harvest. A new bacterial disease was observed on P. notoginseng plants in the Wenshan Mountain area of Yunnan in 2012. The disease affected primarily leaves. Symptoms were circular or irregular brown leaf spots, surrounded by a yellow halo, located on the edges of the leaves. Eight creamy white pigmented, rounded strains were isolated consistently from leaf spots on Luria-Bertani agar (LB) medium, incubated at 28°C. Three strains (SQYB-1, SQYB-2, SQYB-3) of eight isolates were prepared for further study. Three isolates were purified and characterized: all were gram-negative, rod-shaped, motile, aerobic, non-spore forming, and negative for oxidase, potato soft rot, arginine dehydrolase, presence of tyrosinase and urease, nitrate, and fluorescent pigment production. Moreover, they were positive for levan production, presence of catalase, and for tobacco hypersensitivity. All three strains isolated were identified as Pseudomonas syringae pv. syringae (Pss) based on morphology, metabolic profile (Biolog Microbial ID System), and 16S rDNA sequence analysis (1). The metabolic similarity index between experiment strain SQYB-1 and a type of strain Pss was 0.619. The primers of 16S rDNA sequence amplification were 27F/1492R. Before sequencing, we cloned the PCR products. There was 99% homology in 16S rDNA sequences between one isolate, SQYB-1 (NCBI Accession No. JX876901) and Pss (HQ840766), supporting the identification of the P. notoginseng strains as Pss (3). For Koch's postulates, 10 surface-disinfected young leaves on three plants were inoculated with SQYB-1 isolates by spraying a phosphate-buffered saline cell suspension (3.0 × 108 CFU/ml) onto the leaves (4). Controls were inoculated similarly with sterile phosphate-buffered saline. Plants were covered with polyethylene bags for 24 h at 25°C and then transferred to a greenhouse. Circular or irregular brown spots were observed on all bacteria-inoculated leaves within 9 to 14 days after inoculation. No symptoms were observed on controls. Bacteria reisolated from inoculated leaves were identical to the original isolates as determined by the methods described above. The present study indicated that isolate SQYB-1 could independently infect P. notoginseng leaves, which was different from the finding of Luo et al. concerning involvement of Pss in root rot (2). To our knowledge, this is the first report of Pseudomonas syringae pv. syringae causing bacterial leaf spot on P. notoginseng in China. References: (1) M. R. Gillings et al. PNAS 12:102, 2005. (2) W. F. Luo et al. J. Yunnan Agric. Univ. 14:123, 1999 (in Chinese). (3) C. L. Oliver et al. Plant Dis. 4:96, 2012. (4) H. Ornek et al. New Dis. Rep. 13:40, 2006.

Immunogenicity of the envelope GP3 protein of porcine reproductive and respiratory syndrome virus displayed on baculovirus.

Porcine reproductive and respiratory syndrome virus (PRRSV) has been recognized as one of the most important pathogens of pigs throughout the world. The minor envelope protein GP3 of PRRSV plays an important role in clearing of the virus infection and protecting the animals. In this study, a recombinant baculovirus (BacSC-GP3) expressing His6-tagged GP3 with the transmembrane (TM) and cytoplasmic (CT) domains of envelope protein gp64 was constructed and its immunogenicity was evaluated in mouse and piglet models. The His6-tagged GP3 was successfully displayed on the surface of virions as well as virus-infected Sf-9 cells. The animals immunized with BacSC-GP3 gave a slightly higher (piglets) up to a markedly higher (mice) humoral and lymphocyte proliferation responses than those that received a commercial killed vaccine. This is the first study on the immunogenicity of recombinant GP3-baculovirus, which indicates that the latter can represent an alternative strategy for developing a more effective PRRSV vaccine.

Dietary supplementation with glutamine improves gastrointestinal barrier function and promotes compensatory growth of growth-retarded yaks.

The growth retardation of yaks commonly exists on the Tibetan Plateau, and the gastrointestinal barrier function of growth-retarded yaks is disrupted. Glutamine (Gln) is an effective feed additive to improve the gastrointestinal barrier function of animals. This research evaluated the effects of Gln on growth performance, serum permeability parameters, gastrointestinal morphology and barrier function of growth-retarded yaks. Thirty-two male growth-retarded yaks (74.0 ±â€¯6.16 kg of BW and 480 ±â€¯5.50 days of age) were randomly allocated to 4 groups: the negative control (GRY, fed basal ration), Gln1 (fed basal ration and 60 g/d Gln per yak), Gln2 (120 g/d) and Gln3 (180 g/d). Another 8 male growth normal yaks (112 ±â€¯6.11 kg of BW and 480 ±â€¯5.00 days of age) with same breed were used as a positive control (GNY, fed basal ration). The results showed that GRY had lower growth performance and higher (P < 0.05) diamine oxidase, D-lactic acid and lipopolysaccharide concentrations in serum as compared to GNY. Glutamine improved the average daily gain (ADG) of growth-retarded yaks, and the Gln2 group displayed highest ADG. Glutamine supplementation reduced markers of gut permeability in growth-retarded yaks. The GRY and Gln2 groups were selected to study the gastrointestinal barrier function. Growth-retarded yaks fed Gln2 showed higher (P < 0.05) height and surface area of ruminal papillae as compared to GRY. A similar trend of height and surface area in jejunal villus was found between GRY and Gln2 groups. The Gln2 increased (P < 0.05) the concentrations of secretory immunoglobulin A in jejunum and ileum of growth-retarded yaks. The rumen and jejunum of Gln2 yaks exhibited lower (P < 0.05) interleukin-1ß and higher (P < 0.05) interleukin-10 mRNA expressions. Growth-retarded yaks fed Gln2 increased (P < 0.05) the expressions of claudin-1, occludin and zonula occludens-1 in the rumen and jejunum. In conclusion, dietary supplementation with Gln could improve the gastrointestinal barrier function and promote the compensatory growth of growth-retarded yaks.

Metabolism response of grazing yak to dietary concentrate supplementation in warm season.

Supplementary feeding has a significant effect on the growth performance of grazing yaks. However, as far as is known, little information is available concerning how energy or protein feed supplementation affects the serum metabolome of grazing yaks during the warm season. We investigated the effects of supplementation with two different concentrates on the serum metabolome in grazing yaks using nuclear magnetic resonance spectroscopy in conjunction with multivariate data analysis. Twenty-four 2-year-old female yaks (133.04 ± 6.52 kg BW) were randomly divided into three groups and fed three different regimes (n = 8 per group): (1) grazing plus hull-less barley (HLB) supplementation, (2) grazing plus rapeseed meal (RSM) supplementation, and (3) grazing without supplementation. Both HLB and RSM supplementation significantly increased the average daily gain (ADG), and ADG under HLB supplementation was 11.9% higher (P < 0.05) than that of the RSM group. Supplementation markedly altered glucose, lipid, and protein metabolism, with the difference manifested as increased levels of some amino acids, acetyl-glycoproteins, low-density lipoproteins, and very low-density lipoproteins . Furthermore, the levels of 3-hydroxybutyrate, acetoacetate, and lactate metabolism were decreased. Serum metabolite changes in yaks in the HLB supplementation treatment differed from those in the RSM supplementation treatment; the difference was primarily manifested in lipid- and protein-related metabolites. We conclude that both the energy supplementation (HLB) and the protein supplementation (RSM) could remarkably promote the growth of yak heifers during the warm season, and the effect of energy supplementation was superior. Supplementary feeding changed the serum metabolite levels of yak heifers, indicating that such feeding could improve glucose's energy-supply efficiency and increase the metabolic intensity of lipids and proteins. Supplementation of yaks with HLB was more efficient in the promotion of yak glucose and protein anabolism compared to supplementation with RSM, while having a lesser effect on lipid metabolism.

Combination of biomechanical evaluation and accurate placement of dental implants: a new concept of virtual surgery in maxillary and mandibular functional reconstruction.

Biomechanics are crucial for bony regeneration and survival of implants in functional maxillary and mandibular reconstructions. However, we know of no study that has included an analysis of biomechanics to guide the optimal position of a fibular graft in virtual surgery. This study was designed to evaluate the combination of biomechanics and accurate placement of implants for virtual surgery in reconstruction of the jaw using fibular grafts. Thirty-one patients had maxillary or mandibular reconstruction with vascularised fibular grafts and the immediate placement of dental implants. Virtual studies were made preoperatively to evaluate the biomechanics and to assess the position of the fibular grafts with minimal distribution of stress. All operations proceeded accurately and with no complications with a mean (range) of 14 (6-20) months' follow-up. According to the individual biomechanical evaluations, the optimal position for the fibular graft is probably the middle of the mandibular body or below the bottom of the maxillary sinus. The combination of biomechanical evaluation and accurate placement of dental implants is a new concept that could achieve good biomechanical positioning of fibular grafts in the jaw and a desirable level of accuracy for functional reconstruction.

[A multicenter survey of the accessibility of essential medicines for children in China].

Objective: To investigate the availability, prices and affordability of essential medicines in pediatric population across China, in the hope of improving rational use of medicines. Methods: A multicenter cross-sectional survey of medicine prices, availability and affordability was conducted in 17 provinces, municipalities and autonomous region across east, south-central part, west and north of China. Data on 42 medicines used in pediatric population, both original and generic, were collected in 55 public hospitals from May 26 to June 2, 2017. Availability was expressed as the percentage of hospitals with stock of the target medicine on the day of data collection,and median price ratio (MPR) was the ratio of price upon investigation to international reference. Based on national minimum daily wage, affordability represents the number of working days needed to earn the expense which covers a standard course using the target medicine. Statistical software SPSS 13.0 was applied for descriptive analysis of availability, MPR and affordability. Results: Mean Availability of original and generic medicine was 33% and 32%, with median MPR being 5.43 and 1.55. Among the 19 medicines with price information for both original and generic product, the median MPR was 7.73 and 2.04 respectively. Regarding the five medicines used to treat four common pediatric diseases (pneumonia,peptic ulcer, congenital hypothyroidism, refractory nephrotic syndrome), the affordability was 0.63 (0.16-6.17) d for generic medicine, and 1.03 (0.16-11.53) d for its original counterpart. Conclusions: The availability to both original and generic products of the 42 medicines used in pediatric population was low in China. The prices of generic medicines seem to be lower and affordability higher than those of original medicines. There is an urgent need to improve the availability and affordability of pediatric medicines.