Histomorphometrical and molecular evaluation of endosseous dental implants sites in humans: Correlation with clinical and radiographic aspects

Objective: To evaluate the correlations between clinical-radiographical aspects and histomorphometric-molecular parameters of endosseous dental implant sites in humans. Material and methods: The study sample consisted of bone implant sites from the jawbones of 32 volunteers, which were classified according to two different systems: (1) based only on periapical and panoramic images (PP); (2) as proposed by Lekholm & Zarb (L&Z). Bone biopsies were removed using trephine during the first drilling for implant placement. Samples were stained with haematoxylin-eosin (HE), and histomorphometric analysis was performed to obtain the following parameters: trabecular thickness (Tb.Th), trabecular number, bone volume density (BV/TV), bone specific surface (BS/BV), bone surface density and trabecular separation (Tb.Sp). In addition, immunohistochemistry analysis was performed on bone tissue samples for the proteins, Receptor activator of nuclear factor kappa-B (RANK), RANK ligand (RANKL), osteoprotegerin (OPG) and Osteocalcin (OC). Also, the determination of the relative levels of gene expression was performed using Reverse transcription-real-time Polymerase Chain Reaction (RT-PCR). Results: PP and L&Z classification systems revealed a moderate correlation with BV/TV, BS/BV, Tb.Th and Tb.Sp. L&Z's system identified differences among bone types when BV/TV, BS/BV, Tb.Th and Tb.Sp were compared. A weak correlation between PP/L&Z classifications and the expression of bone metabolism regulators (RANK, RANKL, OPG e OC) was found. The analysis of mRNA expression showed no difference between the bone types evaluated. Conclusions: Our results suggest that PP and L&Z subjective bone-type classification systems are related to histomorphometric aspects. These data may contribute to the validation of these classifications. Bone remodelling regulatory molecules do not seem to influence morphological aspects of the jawbone © 2011 John Wiley & Sons A/S.

Major element oxides in ODP Site 164-997 sediments

Since being first discovered in the Blake-Bahama region of the west Atlantic in the 1970s (Hollister, Ewing, et al., 1972, doi:10.2973/dsdp.proc.11.1972), submarine gas hydrates have been identified in the continental margin worldwide. Ocean Drilling Program (ODP) Leg 164 was the first drilling designated to study the occurrence and distribution of natural gas hydrates in Blake Ridge where a well developed, distinct BSR (Bottom Simulating Reflector) has been identified (Paull, Matsumoto, Wallace, et al., 1996, doi:10.2973/odp.proc.ir.164.1996). It has been reported there is a prominent discrepancy between the BSR and the base of gas hydrate stability (Paull, Matsumoto, Wallace, et al., 1996, doi:10.2973/odp.proc.ir.164.1996; Ruppel, 1997, doi:10.1130/0091-7613(1997)025<0699:ACTOAT>2.3.CO;2), though theoretically they should be at the same depth. Natural gas hydrate in marine sediments coexists with sediment particles, so detailed delineation of sediment geochemistry will be of benefit to solve this apparent discrepancy. The main objectives of this study are to supply background data of the major chemical compositions of sediments from a hydrated sediment section.

(Table 1) Physical properties of ODP Site 129-801

Compressional wave velocities and densities were measured for 6 basalt samples from ODP Hole 801B and 16 samples from ODP Hole 801C, a site that represents the first drilling of Jurassic-age crustal rocks in the Pacific basin. Incremental measurements, taken to a total pressure of 200 MPa, show a systematic decrease in velocity with increasing porosity and a related increase with increasing wet-bulk density. A comparison of the plot of porosity vs. compressional wave velocity with the theoretical equation from Wyllie et al. (1958) suggests this equation is inappropriate for oceanic basalts because of mineral alteration in high porosity samples. Also of interest is the dramatic change in velocity across a hydrothermal boundary. Basalts below this hydrothermal layer have a mean velocity of 6.05 km/s at 60 MPa while those above show a mean velocity of 4.55 km/s at 60 MPa. The low velocity values of the basalts above the hydrothermal deposit may be attributed to the higher porosity and composition observed in these rocks; the higher porosity is possibly the result of increased exposure to circulating seawater.

First record of the behavior of latex drainage by Trigona spinipes (Fabricius) (Hymenoptera, Apidae) in laticiferous flowers

This paper describes the behavior of the bee Trigona spinipes, to avoid the latex, when piercing the base of the tubular corolla of the flowers of Mandevilla guanabarica in order to steal the nectar.

Drilling for Papers in INKE

In this article, we discuss the first year research plan for the INKE interface design team, which focuses on a prototype for chaining. Interpretable as a subclass of Unsworths scholarly primitive of discovering, chaining is the process of beginning with an exemplary article, then finding the articles that it cites, the articles they cite, and so on until the reader begins to get a feel for the terrain. The chaining strategy is of particular utility for scholars working in new areas, either through doing background work for interdisciplinary interests or else by pursuing a subtopic in a domain that generates a paper storm of publications every year. In our prototype project, we plan to produce a system that accepts a seed article, tunnels through a number of levels of citation, and generates a summary report listing the most frequent authors and articles. One of the innovative features of this prototype is its use of the experimental oil and water interface effect, which uses text animation to provide the user with a sense of the underlying process.

An Intelligent System for Petroleum Well Drilling Cutting Analysis

Cutting analysis is a important and crucial task task to detect and prevent problems during the petroleum well drilling process. Several studies have been developed for drilling inspection, but none of them takes care about analysing the generated cutting at the vibrating shale shakers. Here we proposed a system to analyse the cutting's concentration at the vibrating shale shakers, which can indicate problems during the petroleum well drilling process, such that the collapse of the well borehole walls. Cutting's images are acquired and sent to the data analysis module, which has as the main goal to extract features and to classify frames according to one of three previously classes of cutting's volume. A collection of supervised classifiers were applied in order to allow comparisons about their accuracy and efficiency. We used the Optimum-Path Forest (OPF), Artificial Neural Network using Multi layer Perceptrons (ANN-MLP), Support Vector Machines (SVM) and a Bayesian Classifier (BC) for this task. The first one outperformed all the remaining classifiers. Recall that we are also the first to introduce the OPF classifier in this field of knowledge. Very good results show the robustness of the proposed system, which can be also integrated with other commonly system (Mud-Logging) in order to improve the last one's efficiency.

Petroleum well drilling monitoring through cutting image analysis and artificial intelligence techniques

Petroleum well drilling monitoring has become an important tool for detecting and preventing problems during the well drilling process. In this paper, we propose to assist the drilling process by analyzing the cutting images at the vibrating shake shaker, in which different concentrations of cuttings can indicate possible problems, such as the collapse of the well borehole walls. In such a way, we present here an innovative computer vision system composed by a real time cutting volume estimator addressed by support vector regression. As far we know, we are the first to propose the petroleum well drilling monitoring by cutting image analysis. We also applied a collection of supervised classifiers for cutting volume classification. (C) 2010 Elsevier Ltd. All rights reserved.

Immediate loading of single SLA implants: drilling vs. osteotomes for the preparation of the implant site

OBJECTIVES: To evaluate whether or not preparation of the implant site with osteotomes instead of drilling may improve peri-implant bone density and/or osseointegration, and whether or not this further improves the predictability of immediate loading of SLA implants. MATERIAL AND METHODS: The second, third, and fourth premolars were extracted in both sides of the mandible in six dogs, and after at least 3 months four SLA implants were inserted into each side of the jaw. In three animals, the implant sites were prepared by means of osteotomes, while standard stepwise drilling was used in the remaining animals. In each side of the jaw, two non-adjacent implants were restored with single crowns 4 days after installation, while the remaining two implants were left without crowns to serve as non-loaded controls. After 2, 4, or 12 weeks of loading, specimens including the implants and surrounding tissues were obtained and processed for histologic analysis of undecalcified sections. RESULTS: All implants placed with osteotomes were lost (five before delivery of the crowns and the rest during the first week after loading). None of the conventionally inserted implants, however, was lost, and histomorphometrical analysis revealed similar soft- and hard peri-implant tissue characteristics at immediately loaded and non-loaded implants at all observation times. Average bone-to-implant contact was 59-72% at immediately loaded implants vs. 60-63% at non-loaded ones. CONCLUSION: Preparation of the implant site by means of osteotomes had a deleterious effect on osseointegration, while immediate loading of single, free-standing, SLA implants following a conventional surgical protocol did not jeopardize their osseointegration.

RADIX: a minimal-resources rapid-access drilling system

Determining the expected age at a potential ice-core drilling site on a polar ice sheet generally depends on a combination of information from remote-sensing methods, estimates of current accumulation and modelling. This poses irreducible uncertainties in retrieving an undisturbed ice core of the desired age. Although recently perfected radar techniques will improve the picture of the ice sheet below future drilling sites, rapid prospective drillings could further increase the success of deep drilling projects. Here we design and explore a drilling system for a minimum-size rapid-access hole. The advantages of a small hole are the low demand for drilling fluid, low overall weight of the equipment, fast installing and de-installing and low costs. We show that, in theory, drilling of a 20mm hole to a depth of 3000m is possible in ~4 days. First concepts have been realized and verified in the field. Both the drill cuttings and the hole itself can be used to characterize the properties of the ice sheet and its potential to provide a trustworthy palaeo-record. A candidate drilling site could be explored in ~2 weeks, which would enable the characterization of several sites in one summer season.

(Table 1) First and last occurrences of the menardellid clade in sediments of ODP Site 154-925

Biostratigraphic and isotopic studies of planktic foraminifera suggest that early to middle Pliocene closure of the Central American Seaway caused vicariant speciation among previously cosmopolitan menardellid foraminifera. New morphospecies were restricted to the tropical Atlantic. Isotopic data suggest that newly evolved Atlantic menardellids were adapted to more oligotrophic conditions, living higher in the water column than ancestral forms and perhaps harboring photosymbionts. In the late Pliocene, all but one menardellid morphospecies became extinct. These extinctions coincided with a progressive increase in the amplitude of periodic climatic change and the end of isolated tropical Atlantic surface circulation as Northern Hemisphere glaciation intensified.

Amino acid in Deep Sea Drilling Project cores

Several amino acid diagenetic reactions, which take place in the deep-sea sedimentary environment, were investigated, using various Deep Sea Drilling Project (DSDP) cores. Initially it was found that essentially all the amino acids in sediments are bound in peptide linkages; but, with increasing age, the peptide bonds undergo slow hydrolysis that results in an increasingly larger fraction of amino acids in the free state. The hydrolysis half-life in calcareous sediments was estimated to be ~1-2 million years, while in non-carbonate sediment the hydrolysis rate may be considerably slower. The amino acid compositions and the extent of racemization of several amino acids were determined in various fractions isolated from the sediments. These analyses demonstrated that the mechanism, kinetics, and rate of amino acid diagenesis are highly dependent upon the physical state (i.e., free, bound, etc.) in which the amino acids exist in the sedimentary environment. In the free state, serine and threonine were found to decompose primarily by a dehydration reaction, while in the bound state (residue or HCl-insoluble fraction) a reversible aldol-cleavage reaction is the main decomposition pathway of these amino acids. The change in amino acid composition of the residue fraction with time was suggested to be due to the hydrolysis of peptide bonds, while in foraminiferal tests the compositional changes over geological time are the result of various decomposition reactions. Reversible first-order racemization kinetics are not observed for free amino acids in sediments. The explanation for these anomalous kinetics involves a complex reaction series which includes the hydrolysis of peptide bonds and the very rapid racemization of free amino acids. The racemization rates of free amino acids in sediments were found to be many orders of magnitude faster than those predicted from elevated temperature experiments using free amino acids in aqueous solution. The racemization rate enhancement of free amino acids in sediments may be due to the catalysis of the reaction by trace metals. Reversible first-order kinetics are followed for amino acids in the residue fraction isolated from sediments; the rate of racemization in this fraction is slower than that predicted for protein-bound amino acids. Various applications of amino acid diagenetic reactions are discussed. Racemization and the decomposition reaction of serine and threonine can both be used, with certain limitations, to make rough age estimates of deep-sea sediments back to several million years. The extent of racemization in foraminiferal tests which have been dated by some other independent technique can be used to estimate geothermal gradients, and thus heat flows, and to evaluate the bottom water temperature history in certain oceanic areas.