The Evolution of Dental Journals from 2003 to 2012: A Bibliometric Analysis

Bibliometrics are a set of methods, which can be used to analyze academic literature quantitatively and its changes over time. The objectives of this study were 1) to evaluate trends related to academic performance of dental journals from 2003 to 2012 using bibliometric indices, and 2) monitor the changes of the five dental journals with the highest and lowest impact factor (IF) published in 2003. Data for the subject category "Dentistry, Oral Surgery & Medicine" was retrieved from the Journal Citation Reports (JCR) published from 2003 to 2012. Linear regressions analysis was used to determine statistical trends over the years with each bibliometric indicator as the dependent variable and the JCR year as the predictor variable. Statistically significant rise in the total number of dental journals, the number of all articles with the steepest rise observed for research articles, the number of citations and the aggregate IF was observed from 2003 to 2012. The analysis of the five top and five bottom-tire dental journals revealed a rise in IF however, with a wide variation in relation to the magnitude of this rise. Although the IF of the top five journals remained relatively constant, the percentile ranks of the four lowest ranking journals in 2003 increased significantly with the sharpest rise being noted for the British Journal of Oral & Maxillofacial Surgery. This study revealed significant growth of dental literature in absolute terms, as well as upward trends for most of the citation-based bibliometric indices from 2003 to 2012.     

Dihedral angle and secondary structure database of short amino acid fragments

Dihedral angles of amino acids are of considerable importance in protein tertiary structure prediction as they define the backbone of a protein and hence almost define the protein's entire conformation. Most ab initio protein structure prediction methods predict the secondary structure of a protein before predicting the tertiary structure because three-dimensional fold consists of repeating units of secondary structures. Hence, both dihedral angles and secondary structures are important in tertiary structure prediction of proteins. Here we describe a database called DASSD (Dihedral Angle and Secondary Structure Database of Short Amino acid Fragments) that contains dihedral angle values and secondary structure details of short amino acid fragments of lengths 1, 3 and 5. Information stored in this database was extracted from a set of 5,227 non-redundant high resolution (less than 2-angstroms) protein structures. In total, DASSD stores details for about 733,000 fragments. This database finds application in the development of ab initio protein structure prediction methods using fragment libraries and fragment assembly techniques. It is also useful in protein secondary structure prediction.

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Structure of the Epiphyte Community in a Tropical Montane Forest in SW China

Vascular epiphytes are an understudied and particularly important component of tropical forest ecosystems. However, owing to the difficulties of access, little is known about the properties of epiphyte-host tree communities and the factors structuring them, especially in Asia. We investigated factors structuring the vascular epiphyte-host community and its network properties in a tropical montane forest in Xishuangbanna, SW China. Vascular epiphytes were surveyed in six plots located in mature forests. Six host and four micro-site environmental factors were investigated. Epiphyte diversity was strongly correlated with host size (DBH, diameter at breast height), while within hosts the highest epiphyte diversity was in the middle canopy and epiphyte diversity was significantly higher in sites with canopy soil or a moss mat than on bare bark. DBH, elevation and stem height explained 22% of the total variation in the epiphyte species assemblage among hosts, and DBH was the most important factor which alone explained 6% of the variation. Within hosts, 51% of the variation in epiphyte assemblage composition was explained by canopy position and substrate, and the most important single factor was substrate which accounted for 16% of the variation. Analysis of network properties indicated that the epiphyte host community was highly nested, with a low level of epiphyte specialization, and an almost even interaction strength between epiphytes and host trees. Together, these results indicate that large trees harbor a substantial proportion of the epiphyte community in this forest.     

Plant ecology of tropical and subtropical karst ecosystems

Substantial areas of tropical forests, including those within nine tropical biodiversity hotspots, contain karst landscapes that have developed on soluble carbonate rocks. Here, we review how the ecology of karst forest trees is influenced by hydrological, edaphic, and topographic factors that exhibit fine spatial heterogeneity. Comparative analysis of drought tolerance traits including wood density contributes to the assessment of whether karst tree species are more drought‐tolerant compared to non‐karst trees. Although karst ecosystems are generally considered to have low phosphorus availability, foliar nitrogen‐to‐phosphorus ratios exhibit wide variation across karst regions without a clear difference from non‐karst ecosystems. According to the analyses of leaf phenology, stem water storage, and isotopic signatures from xylem sap, water use strategies of karst trees can be classified into five types: (a) soil water dependent, (b) epikarst water dependent (mainly use water stored in fine pores and gaps within the epikarst rock during the dry season), (c) groundwater dependent, (d) fog water dependent, and (e) drought‐deciduous (shed leaves during the dry season). Overall, published data suggest that only a subset of karst tree species are exclusively distributed within karst hilltops where water availability is limited. The diverse resource acquisition and utilization strategies of karst plants across edaphic habitats must be considered when developing effective strategies to conserve and restore biodiversity in karst landscapes, which are under increasing anthropogenic pressure.     

西双版纳布龙自然保护区勐宋片区附生维管植物多样性与分布特征

利用地面观测和单绳上树法初次对布龙自然保护区勐宋片区开展的附生维管植物调查表明:1)在6个样地77株宿主上(共调查96株乔木,占地约0.2ha),共有1 756株、丛个体,隶属14科47属103种;相比世界其他区域,物种丰富度处于旧世界热带水平区间,高于温带,但明显低于新世界热带水平;2)兰科植物为最丰富的类群(60％),其次为蕨类植物(24％),其他类群占16％;3)垂直分布特征研究表明,距地面10～ 15 m的中等高度带为物种最丰富的区间,约有51％的物种;0～5m高度带为个体数量最多的区间,共有约24％个体,揭示了除中等高度带以外的另一个重要附生生境;4)常见的绞杀型榕属植物未见,而半附生植物密脉鹅掌柴(Schefflera elliptica)和多蕊木(Tupidanthus calyptratus)数量较多.     

Deformation behaviour of stomatocyte,discocyte and echinocyte red blood cell morphologies during optical tweezers stretching

Biomechanics and Modeling in Mechanobiology - The red blood cell (RBC) deformability is a critical aspect, and assessing the cell deformation characteristics is essential for better diagnostics of...     

Leaf trait variations associated with habitat affinity of tropical karst tree species

Karst hills, that is, jagged topography created by dissolution of limestone and other soluble rocks, are distributed extensively in tropical forest regions, including southern parts of China. They are characterized by a sharp mosaic of water and nutrient availability, from exposed hilltops with poor soil development to valleys with occasional flooding, to which trees show species‐specific distributions. Here we report the relationship of leaf functional traits to habitat preference of tropical karst trees. We described leaf traits of 19 tropical tree species in a seasonal karst rainforest in Guangxi Province, China, 12 species in situ and 13 ex situ in a non‐karst arboretum, which served as a common garden, with six species sampled in both. We examined how the measured leaf traits differed in relation to species’ habitat affinity and evaluated trait consistency between natural habitats vs. the arboretum. Leaf mass per area (LMA) and optical traits (light absorption and reflectance characteristics between 400 and 1,050 nm) showed significant associations with each other and habitats, with hilltop species showing high values of LMA and low values of photochemical reflectance index (PRI). For the six species sampled in both the karst forest and the arboretum, LMA, leaf dry matter content, stomatal density, and vein length per area showed inconsistent within‐species variations, whereas some traits (stomatal pore index and lamina thickness) were similar between the two sites. In conclusion, trees specialized in exposed karst hilltops with little soils are characterized by thick leaves with high tissue density indicative of conservative resources use, and this trait syndrome could potentially be sensed remotely with PRI.     

The Oropharyngeal Airway in Young Adults with Skeletal Class II and Class III Deformities: A 3-D Morphometric Analysis

Objectives

1) To determine the accuracy and reliability of an automated anthropometric measurement software for the oropharyngeal airway and 2) To compare the anthropometric dimensions of the oropharyngeal airway in skeletal class II and III deformity patients.

Methods

Cone-beam CT (CBCT) scans of 62 patients with skeletal class II or III deformities were used for this study. Volumetric, linear and surface area measurements retroglossal (RG) and retropalatal (RP) compartments of the oropharyngeal airway was measured with the 3dMDVultus software. Accuracy of automated anthropometric pharyngeal airway measurements was assessed using an airway phantom.

Results

The software was found to be reasonably accurate for measuring dimensions of air passages. The total oropharyngeal volume was significantly greater in the skeletal class III deformity group (16.7 ± 9.04 mm³) compared with class II subjects (11.87 ± 4.01 mm³). The average surface area of both the RG and RP compartments were significantly larger in the class III deformity group. The most constricted area in the RG and RP airway was significantly larger in individuals with skeletal class III deformity. The anterior-posterior (AP) length of this constriction was significantly greater in skeletal class III individuals in both compartments, whereas the width of the constriction was not significantly different between the two groups in both compartments. The RP compartment was larger but less uniform than the RG compartment in both skeletal deformities.

Conclusion

Significant differences were observed in morphological characteristics of the oropharyngeal airway in individuals with skeletal class II and III deformities. This information may be valuable for surgeons in orthognathic treatment planning, especially for mandibular setback surgery that might compromise the oropharyngeal patency.