bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of 2 Regenerative Procedures—Guided Tissue Regeneration and Demineralized Freeze‐Dried Bone Allograft—in the Treatment of Intrabony Defects: A Clinical and Radiographic Study
Authors: Parashis A. , Andronikaki‐Faldami A. , Tsiklakis K.
Published: March 2012

The purpose of this study was to compare clinically and radiographically the effectiveness of guided tissue regeneration (GTR), using a bioabsorbable polylactic acid softened with citric acid ester barrier and commercially available demineralized freezedried bone allograft (DFDBA) in the treatment of 2‐ and 3‐wall intrabony defects. Twelve patients each with one treated defect comprised each group. Conservative treatment was completed 2 to 4 months prior to surgery. Clinical measurements, plaque index, gingival index, probing depths (PD), clinical attachment levels (CAL) and recession (REC), were comparable in both groups at baseline. They were repeated at 12 months. Surgical measurements were also comparable at baseline in both groups. In the GTR group, at baseline the mean distance between the cemento‐enamel junction (CEJ) and base of the defect was 12.3 ± 2.9 mm and in the DFDBA group 11.3 ± 1.8 mm. The defect depth was 6.3 ± 2.0 mm and 5.4 ± 1.3 mm, respectively. Radiographs were taken at baseline and 12 months later and compared using non‐standardized digital subtraction radiography. In the GTR group, mean PD decreased from 7.9 ± 2.5 mm to 3.5 ± 1.4 mm and mean CAL from 10.8 ± 2.8 mm to 7.0 ± 1.6 mm, the differences being statistically significant (P = 0.002), while REC increased from 2.9 ± 1.2 mm to 3.5 ± 1.1 mm. In the DFDBA group, mean PD decreased from 7.1 ± 1.1 mm to 3.5 ± 1.1 mm and mean CAL from 9.8 ± 1.5 mm to 6.6 ± 1.7 mm (P = 0.002), while REC increased from 2.8 ± 1.0 mm to 3.1 ± 1.2 mm. No significant differences were found when the clinical results of the 2 groups were compared. Radiographic differences between the baseline and reconstructed images 12 months later were observed in both groups. Mean crestal bone resorption was 15.3 ± 22.5% in the GTR group and 10.4 ± 31.8% in the DFDBA group, and mean improvement in the distance between the CEJ and the base of the defect was 22.8 ± 18.1% in the GTR group and 15.3 ± 13.6% in the DFDBA group. However, the mean improvement in the intrabony depth was larger in the GTR group (71.9 ± 29.1%) than in the DFDBA group (35.4 ± 21.6%) (P = 0.007). In conclusion, within the limits of this study, both regenerative procedures were beneficial in treating intrabony defects. No statistical significant differences were observed between the 2 groups, with the exception of radiographie defect resolution which was significantly greater in the GTR group. J Periodontol 1998;69:751–758.
Clinical Evaluation of Systemic Doxycycline and Ibuprofen Administration as an Adjunctive Treatment for Adult Periodontitis
Authors: Ng Veronica W‐K , Bissada Nabil F.
Published: March 2012

The objective of this study was to compare the efficacy of a systemic antibiotic (doxycycline) and a non‐steroidal anti‐inflammatory drug (ibuprofen), administered either separately or combined, as an adjunctive treatment of scaling/root planing (SRP). Thirty‐two subjects diagnosed with generalized moderate adult periodontitis and having at least 2 teeth with ≥5 mm probing depth were randomly divided into 4 groups. Each group was treated with oral doxycycline and/or ibuprofen for 6 weeks as follows: group 1, doxycycline 200 mg the first day followed by 100 mg per day; group 2, ibuprofen 800 mg per day; group 3, doxycycline plus ibuprofen scheduled as in groups 1 and 2; group 4, one placebo capsule/day (control). A split mouth design was utilized in each subject such that half of the teeth received one session of scaling/root planing (SRP), while the other half received no SRP. Plaque index (PI), gingival index (GI), probing depth (PD), and clinical attachment level (CAL) using a customized acrylic stent were recorded at baseline and at 3, 6, 12, and 24 weeks following SRP. Analysis using ANOVA and Student f‐test showed statistical significance (P≤0.05) from baseline data in: 1) gains of 0.4 mm and 0.5 mm of CAL for groups 1 and 3, respectively; 2) reduction of 0.7 mm PD for group 3; 3) reduction of 0.4 and 0.1 GI scores for groups 1 and 3, respectively; and 4) gain of 0.5 mm CAL and reductions of 0.4 mm PD and 0.2 GI score for the SRP group when compared to the no SRP group at 24 weeks. It may be concluded that the adjunctive use of systemic doxycycline alone or in combination with ibuprofen results in a statistically significant, yet modest clinical, improvement beyond that obtained by scaling/root planing. J Periodontol 1998;69:772–776.
Effects of Ketorolac Tromethamine Mouthrinse (0.1%) on Crevicular Fluid Prostaglandin E2 Concentrations in Untreated Chronic Periodontitis
Authors: Preshaw Philip M. , Lauffart Brenda , Brown Philip , Zak Elena , Heasman Peter A.
Published: March 2012

The effects of topical ketorolac tromethamine mouthrinse (0.1%) on gingival crevicular fluid (GCF) prostaglandin E2 (PGE2) concentrations were investigated in a 6‐week, randomized, double‐blind, placebo‐controlled, parallel group, single center study of 42 patients with moderately advanced chronic adult periodontitis. Following screening, GCF was sampled from 6 sites per subject with filter paper strips and PGE2 levels measured using an enzyme immunoassay kit. Only those subjects with mouth median GCF PGE2 concentrations >30 ng/ml entered the rinsing phase. Eligible subjects were allocated placebo rinse in the first 2‐week period (days 0 through 14), either ketorolac rinse (test group, n = 21) or placebo rinse (control group, n = 21) in the second 2‐week period (days 14 through 28), and placebo rinse in the third 2‐week period (days 28 through 42). Full mouth median GCF PGE2 concentrations were calculated for each subject at days 0, 14, 28, and 42, and group means were compared. From day 0 to day 14, no significant changes in GCF PGE2 concentrations were detected in either study group (P > 0.05). Utilizing mean GCF PGE2 concentrations at days 0 and 14 as covariates, no significant differences were observed in adjusted mean PGE2 levels at days 28 and 42 between the study groups (ANCOVA, P > 0.05). A statistically significant increase in GCF PGE2 levels was noted at days 28 and 42 in the placebo group (P < 0.01), but not in the ketorolac group (P > 0.05), when compared to baseline, however. GCF PGE2 levels were further studied in a subset of volunteers (n = 11) during a 12‐hour period following first rinsing with mouthrinse (active or placebo) at day 14. GCF was sampled 0, 2, 4, 6, 8, and 12 hours postrinsing. Mean PGE2 levels were higher in the placebo subgroup than in the ketorolac subgroup, and increased gradually over the 12‐hour period in both subgroups. These data indicate that 1) 14 days of rinsing with 0.1% ketorolac mouthrinse controlled the elevation of GCF PGE2 observed in the placebo group but did not actually reduce GCF PGE2 concentrations and 2) changes in GCF PGE2 levels were not detectable in the 12‐hour period following first rinsing with ketorolac. J Periodontol 1998;69:777–783.
Surgical Treatment of Cyclosporine A‐ and Nifedipine‐Induced Gingival Enlargement: Gingivectomy Versus Periodontal Flap
Authors: Pilloni Andrea , Camargo Paulo M. , Carere Mauro , Carranza Fermin A.
Published: March 2012

The purpose of this study was to compare probing depth resolution achieved by gingivectomy and periodontal flap techniques in the treatment of cyclosporine A‐ and nifedipine‐induced gingival enlargement. Ten kidney transplant patients who were receiving cyclosporine A and nifedipine for at least 6 months participated in the study. Five patients were randomly assigned to the gingivectomy group and 5 patients to the periodontal flap group. Only anterior segments of the oral cavity (canine to canine) were surgically treated. Clinical measurements, including probing depths, plaque index, and gingival sulcus index, were taken at baseline, 6 weeks, 6 months, and 1 year. Results showed that probing depths, while similar for both groups in the first 6 weeks of the study, were significantly shallower for the periodontal flap group when compared to the gingivectomy group at 6 months (2.48 ± 0.34 mm versus 4.87 ± 0.79 mm, respectively) and 1 year (322 ± 0.65 mm versus 6.40 ± 1.02 mm, respectively). Within its limitations, this study suggests that the pocket reduction achieved by the periodontal flap may be sustained for longer periods of time than by the gingivectomy technique in the treatment of cyclosporine A‐ and nifedipine‐induced gingival enlargement. J Periodontol 1998;69:791–797.
Maxillary Sinus Augmentation in the Non‐Human Primate: A Comparative Radiographic and Histologic Study Between Recombinant Human Osteogenic Protein‐1 and Natural Bone Mineral
Authors: Margolin Mark D. , Cogan Allan G. , Taylor Mary , Buck Dave , McAllister Todd N. , Toth Carol , McAllister Bradley S.
Published: March 2012

The posterior maxilla has traditionally been one of the most difficult areas to successfully place dental implants due to poor bone quality and close approximation to the maxillary sinus. Sinus augmentation procedures have become a viable means of assuring adequate bone for the placement of dental implants in this area. However, with the techniques currently employed, a considerable variation in the quality of bone attained with the sinus augmentation procedure exists. The purpose of this in vivo study was to evaluate the healing response and bone formation stimulated by 3 doses of recombinant human osteogenic protein‐1 (rhOP‐1), 0.25, 0.6, and 2.5 mg OP‐1 per gram of collagen matrix; natural bone mineral; or collagen matrix alone (control) placed in the maxillary sinus of adult chimpanzees. Results were assessed using clinical, histologic, and radiographic techniques. Radiographic analysis of the computed tomography scans taken at 1 week, and 2.5, 4.5, and 6.5 months revealed a more rapid mineralization with the 2.5 mg OP‐1/g collagen matrix and natural bone mineral treatment groups. The incremental bone mineral density (BMD) increase for these 2 treatments from 1 week to 2.5 months was over 2.5 times the increase found with the collagen matrix alone; these 2 treatments also had a higher BMD at the most superior slices evaluated when compared to the other 3 groups. Biopsy specimens were taken at 3.5, 5.5, and 7.5 months and for all 5 treatment groups bone formation was observed at all time points in the majority of the specimens. At 7.5 months the 2.5 and 0.6 mg OP‐1/g collagen matrix treatment groups had an increase in the percent bone area when compared to the matrix alone control. In conclusion, these results demonstrate that sinus augmentation with natural bone mineral or 2.5 mg OP‐1/g collagen matrix induce comparable radiographic and histologic evidence of bone formation and that both of these treatments performed superior to the control group of collagen matrix alone based upon all methods of evaluation. J Periodontol 1998;69:911–919.
A Prospective Clinical Trial of Endosseous Screw‐Shaped Implants Placed at the Time of Tooth Extraction Without Augmentation
Authors: Becker Burton E. , Becker William , Ricci Andrea , Geurs Nico
Published: March 2012

This prospective clinical trial evaluated 134 implants in 81 patients. The implants were placed at the time of tooth extraction and were not augmented with barrier membranes or graft materials. The implants were placed into good jaw bone anatomy and quality and were restored by dentists familiar with the implant system. Fortyseven implants were followed between 4 to 5 years with a cumulative success rate of 93.3%. Marginal bone levels were measured for 61 patients with 108 implants. The average mesial‐distal measurements for maxillary implants at abutment connection were 1.02 mm (SD ± 0.59) and 1.36 mm (SD ± 0.78) at an average of 32 months follow‐up. These differences were not significant. The average mandibular mesialdistal measurements at abutment connection were 1.05 mm (SD ± 0.92) and 1.54 mm (SD ± 0.91) at follow‐up. These differences were statistically significant (P = 0.0027). Removal of one patient (5 implants) with advanced marginal bone loss from the data provided a marginal bone level of 1.20 mm (SD ± 0.94) at abutment connection and 1.30 mm (SD ± 0.87) at follow‐up. These differences were not significant. The results of this study indicate that implants placed at the time of extraction without augmentation or grafting have excellent long‐term cumulative success rates. J Periodontol 1998;69:920–926.
Carious Lesions in the Heroin Addicted Patient. A Case Report
Authors: Shen E‐Chin , Fu Earl
Published: March 2012

Heroin abuse is destroying the health of many individuals in our society. Much of the information that has appeared in the literature has concerned itself with the general health of addicts; the oral health status of these individuals has not been studied to the same extent. This report will present and discuss the management of a case involving the effects of long‐term heroin abuse on the dentition. J Periodontol 1998;69:938–940.
The Response of Periodontal Ligament Cells to Fibronectin
Authors: Kapila Yvonne L. , Lancero Hope , Johnson Paul W.
Published: March 2012

Fibronectin (FN) is an extracellular matrix (ECM) molecule important in cell adhesion and migration and in wound healing. It is also likely important in periodontal ligament (PDL) cell–ECM interactions, and thus in regenerating periodontal tissues. In this study we characterized PDL cells and their interactions with FN, testing different PDL cell isolates taken from healthy and diseased conditions. PDL cells were characterized by their morphology, integrin profile, motility, and bone nodule formation. Cells were then assayed for adhesion, proliferation, and Chemotaxis in response to FN or FN fragments. Cell isolates were morphologically heterogeneous and fibroblastic, had a normal‐appearing actin cytoskeleton and a wide range of migration potentials, and formed bone‐like nodules in vitro. They expressed α5, β1, αv, and α4 integrin subunits, known receptors for FN, and in fact they bound FN preferentially at 5 and 10 μg/ml. Intact FN induced greater PDL cell proliferation and Chemotaxis than did FN fragments (120‐kDa cell‐binding, 60‐kDa heparin‐binding, and 45‐kDa collagen‐binding). PDL cells harvested from diseased and healthy conditions were no different on the basis of these assays. These data demonstrate that PDL cells are a mixed population of fibroblastic cells, capable of forming a mineralized matrix. They also suggest that maximal proliferation and Chemotaxis require specific FN domains that are present on the intact molecule but not its fragments. J Periodontol 1998;69:1008–1019.
Clinical Evaluation of Bioactive Glass in the Treatment of Periodontal Osseous Defects in Humans
Authors: Lovelace Teri Brooks , Mellonig James T. , Meffert Roland M. , Jones Archie A. , Nummikoski Pirkka V. , Cochran David L.
Published: March 2012

The purpose of this study was to compare the use of bioactive glass to demineralized freeze‐dried bone allograft (DFDBA) in the treatment of human periodontal osseous defects. Fifteen systemically healthy patients (6 males and 9 females, aged 30 to 63) with moderate to advanced adult periodontitis were selected for the study. All patients underwent initial therapy, which included scaling and root planing, oral hygiene instruction, and an occlusal adjustment when indicated, followed by re‐evaluation 4 to 6 weeks later. Paired osseous defects in each subject were randomly selected to receive grafts of bioactive glass or DFDBA. Both soft and hard tissue measurements were taken the day of surgery (baseline) and at the 6‐month re‐entry surgery. The clinical examiner was calibrated and blinded to the surgical procedures, while the surgeon was masked to the clinical measurements. Statistical analysis was performed by using the paired Student's t test. The results indicated that probing depths were reduced by 3.07 ± 0.80 mm with the bioactive glass and 2.60 ± 1.40 mm with DFDBA. Sites grafted with bioactive glass resulted in 2.27 ± 0.88 mm attachment level gain, while sites grafted with DFDBA had a 1.93 ± 1.33 mm gain in attachment. Bioactive glass sites displayed 0.53 ± 0.64 mm of eresiai resorption and 2.73 mm bone fill. DFDBA‐grafted sites experienced 0.80 ± 0.56 mm of crestal resorption and 2.80 mm defect fill. The use of bioactive glass resulted in 61.8% bone fill and 73.33% defect resolution. DFDBA‐grafted defects showed similar results, with 62.5% bone fill and 80.87% defect resolution. Both treatments provided soft and hard tissue improvements when compared to baseline (P ≤ 0.0001). No statistical difference was found when comparing bioactive glass to DFDBA; however, studies with larger sample sizes may reveal true differences between the materials. This study suggests that bioactive glass is capable of producing results in the short term (6 months) similar to that of DFDBA when used in moderate to deep intrabony periodontal defects. J Periodontol 1998;69:1027–1035.
The Application of Deproteinized Bovine Bone Mineral for Ridge Preservation Prior to Implantation. Clinical and Histological Observations in a Case Report
Authors: Artzi Zvi , Nemcovsky Carlos E.
Published: March 2012

Alveolar ridge preservation following tooth extraction is important when implantsupported oral rehabilitation is considered. The ability to maintain the ridge allows implant placement in an ideal position, fulfilling both functional and esthetic demands. A deproteinized bovine bone mineral (DBBM) was used as a socket site filler material to maintain ridge configuration, without applying an occlusive membrane. The material was grafted and packed onto the socket sites immediately after extractions, and subsequently primary soft tissue closure was attempted. The ridge healed for 9 months before the second surgical procedure, in which the implant was placed. New bone formation was observed in all histological specimens. DBBM particles adhered to a highly osteocyte‐rich woven and lamellar‐type bone. Clinically and histologically, this report demonstrated DBBM particles to be an effective biocompatible filler agent in extraction sockets for ridge preservation prior to titanium fixture implantation. Randomized controlled clinical trials are needed to fully evaluate the usefulness of this material in ridge preservation after tooth extraction. J Periodontol 1998;69:1062–1067.
Acceptance Program Guidelines: Products Designed to Regenerate Periodontal Tissues
Authors:   Council on Scientific Affairs
Published: March 2012

Scope: These Guidelines apply to products used to promote the regeneration of periodontal tissues lost due to periodontal diseases or other causes. Periodontal regeneration is defined histologically as regeneration of the tooth's supporting tissues, including alveolar bone, periodontal ligament, and cementum over a previously diseased root surface. Regenerative procedures must enhance the formation of a new attachment apparatus demonstrated by randomized controlled histological studies in animals, verified by human histologic evidence, and supported by beneficial results in human randomized controlled clinical trials.
Adjunctive Use of a Subgingival Controlled‐Release Chlorhexidine Chip Reduces Probing Depth and Improves Attachment Level Compared With Scaling and Root Planing Alone
Authors: Jeffcoat Marjorie K. , Bray Kimberly S. , Ciancio Sebastian G. , Dentino Andrew R. , Fine Daniel H. , Gordon Jeffrey M. , Gunsolley John C. , Killoy William J. , Lowenguth Roxanne A. , Magnusson N. Ingvar , Offenbacher Steven , Palcanis Kent G. , Proskin Howard M. , Finkelman Richard D. , Flashner Moshe
Published: March 2012

The present studies evaluated the efficacy of a controlled‐release biodegradable Chlorhexidine (CHX) (2.5 mg) chip when used as an adjunct to scaling and root planing on reducing probing depth (PD) and improving clinical attachment level (CAL) in adult periodontitis. Two double‐blind, randomized, placebo‐controlled multicenter clinical trials (5 centers each) were conducted; pooled data are reported from all 10 centers (447 patients). At baseline, following 1 hour of scaling and root planing (SRP) in patients free of supragingival calculus, the chip was placed in target sites with PD 5 to 8 mm which bled on probing. Chip placement was repeated at 3 and/or 6 months if PD remained ≥ 5 mm. Study sites in active chip subjects received either CHX chip plus SRP or SRP alone (to maintain study blind). Sites in placebo chip subjects received either placebo chip plus SRP or SRP alone. Examinations were performed at baseline; 7 days; 6 weeks; and 3, 6, and 9 months. At 9 months significant reductions from baseline favoring the Chlorhexidine chip compared with both control treatments were observed with respect to PD (Chlorhexidine chip plus SRP, 0.95 ± 0.05 mm; SRP alone, 0.65 ± 0.05 mm, P < 0.001; placebo chip plus SRP, 0.69 ± 0.05 mm, P < 0.001) and CAL (Chlorhexidine chip plus SRP, 0.75 ± 0.06 mm; SRP alone, 0.58 ± 0.06 mm, P < 0.05; placebo chip plus SRP, 0.55 ± 0.06 mm, P < 0.05). The proportion of patients who evidenced a PD reduction from baseline of 2 mm or more at 9 months was significantly greater in the Chlorhexidine chip group (19%) compared with SRP controls (8%) (P < 0.05). Adverse effects were minor and transient toothache, including pain, tenderness, aching, throbbing, soreness, discomfort, or sensitivity was the only adverse effect that was higher in the Chlorhexidine group as compared to placebo (P = 0.042). These data demonstrate that the adjunctive use of the Chlorhexidine chip results in a significant reduction of PD when compared with both SRP alone or the adjunctive use of a placebo chip. These multi‐center randomized control trials suggest that the Chlorhexidine chip is a safe and effective adjunctive chemotherapy for the treatment of adult periodontitis. J Periodontol 1998;69:989–997.
Post-Frac Production Analysis of Horizontal Completions in CANA Woodford Shale
Authors: Grieser Bill , Talley Chris
Published: March 2012

The Oklahoma Woodford shale has produced hydrocarbon since the early 1950s. Recent horizontal development using multistage fracture stimulations of the CANA Woodford located in the Anadarko basin has resulted in high initial gas-flow rates, and substantial liquid production when in the gas-condensate window. Completion type and strategy have changed from methods used during the initial discovery phase in 2005 to the present development phase in 2011. This paper compares completion parameters used for a given time period to the individual production trend, using a linear flow transient model. Using the normalized reciprocal rate/pressure versus the square root of time plot, the stimulated reservoir volume (SRV), effective fracture half-lengths, reservoir-system permeability (km h), productivity index (PI), and overall stimulation effectiveness were determined.

Ranking of fracture-stimulation effectiveness is made from production-derived bulk reservoir properties, including The product of fracture-surface area and square root of the effective formation permeability (Ackm1/2).Apparent skin (s’) from the b’ intercept of the square root of time plot; an indication of skin.Hydrocarbon pore volume (HCPV).

The results are summarized in tables showing the effect of completion factors on the production outcome.
Unconventional Shale Play Selective Fracturing Using Multilateral Technology
Authors: Durst Doug G. , Vento Mario
Published: March 2012

Drilling, completing, and fracturing of unconventional formation wells in North America are now commonplace and will begin to play a role in the future of natural gas production in the international market. What is not as common is to drill, complete, and frac multiple lateral branches from a single main wellbore. Multilateral wells have been routinely drilled for a number of applications, and shale plays are a natural progression for its use. Augmenting a multilateral well with selective fracturing of each leg is as straightforward as fracing a single horizontal well.

Using conventional equipment and techniques, a multilateral well (with any number of laterals) can accommodate any type of fracturing system and program with pressures up to 12,500 psi with complete isolation of the lateral junction(s). In this project, a plug-and-perf system was used to address ten plus intervals in each leg, with average stimulation pressures up to 9,000 psi.

Multilateral solutions provide the means to work within a limited surface access, generating a reduced footprint while draining a much larger volume of the reservoir from a single-surface location. This poses a significant advantage when drilling in sensitive or restricted locations, populated areas, and where land issues restrict access to multiple drilling locations. Additionally, the cost and impact of large drilling pads or multiple well sites is avoided.

This paper will discuss the implementation and execution of this project, the first dual-lateral well by any operator in the Granite Wash at vertical depths over 12,000 ft. This well targeted two different sections of the Granite Wash (a complex series of sands, shales, and siltstones that run from the northern Texas Panhandle into Oklahoma) from a single main wellbore, with commingled production rates doubling typical single horizontal well performance.
High-Resolution LWD Images Used to Optimize Completions in Unconventional Play - North America
Authors: Janwadkar Sandeep , Thomas Mark , Denney Steve , Hommertzheim Troy , Privott Steve , Rogers Steven , Crespo Luis , Camper Daniel
Published: March 2012

The Barnett Shale is one of the most mature and prolific natural gas fields in North America. It has a multi-trillion-cubic-feet equivalent upside potential but well completions are not resulting in consistent production within the same section or across the unconventional play. As infield drilling increases, collision and encroachment from well to well due from offset induced fractures, natural fractures, faults, and internal stresses are becoming more important to characterize and map. The operator and the service provider teamed up and used high-resolution images to optimize perforation placement, redesign stimulation, and stage placement. To overcome these challenges, high-resolution, state-of-the-art logging-while-drilling (LWD) imaging tools were used to acquire images on a well drilled between two 600-ft (182.9-m) offset wells. These images are also being used to map fracture systems, faults, and stresses in the field. With the knowledge obtained from these LWD images, completions are now being redesigned to incorporate this information for optimizing fracture treatments. The paper will provide examples of high-resolution images generated which were used to determine untreated formation matrix, and avoid faults for possible water production. Proper interpretations of these images and other advanced technologies have enabled operators to increase well productivity up to 20% as compared to offset wells. These advanced technologies have been implemented and used in over 250 wells with excellent results. The images will be used in the future to determine which wells would be the best candidates for recompletions. The lessons learned can be applied to most unconventional plays around the world.
Geosteering in Unconventional Shales: Current Practice and Developing Methodologies
Authors: Pitcher Jason , Jackson Tavia
Published: March 2012

Current well placement in unconventional shale ranges from simple geometric well placement to a gamut of patternrecognition systems and geosteering with geochemical and geomechanical analyses. The wide diversity of systems used leads to uncertainty in the effectiveness of any strategy, with confusion as to the true value or merit of a particular technique. Often, a well-placement strategy is based on what came before, with little regard as to the complexities or differences between reservoirs.

This paper reviews the current common practices used in geosteering in shales, for both gas- and oil-producing reservoirs. A brief history of strategy development is outlined, with comments about its perceived effectiveness and value. Examples of successes and failures are examined to attempt to determine the viability of a particular strategy.

Finally, alternative approaches and methodologies are reviewed and examined, with comments about the potential application, benefits, and value.
Shale Reservoir Properties from Digital Rock Physics
Authors: Walls Joel D. , Diaz Elizabeth , Cavanaugh Timothy
Published: March 2012

A majority of the whole core samples recovered in the US today come from shale reservoirs. A primary reason for so much shale coring is that shale well log analysis requires rigorous core calibration to provide reliable data for reservoir quality, hydrocarbon-in-place, and hydraulic fracturing potential. However, the uncertainty in interpreting shale well log data is sometimes matched or exceeded by the uncertainty observed in traditional methods of analyzing core samples. Most commercial core analysis methods in use today were developed originally for sandstones and carbonates exceeding 1 millidarcy in permeability. High quality, organic-rich shale on the other hand is usually lower than 0.001 millidarcy. This extremely low permeability creates substantial challenges for existing methods and has contributed to the rapid rise of a new approach to reservoir evaluation called Digital Rock Physics (DRP).

DRP merges three key technologies that have evolved rapidly over the last decade. One is high resolution diagnostic imaging methods that permit detailed examination of the internal structure of rock samples over a wide range of scales. The second is advanced numerical methods for simulating complex physical phenomenon and the third is high speed, massively parallel computation using powerful graphical processing units (GPUs) that were originally developed for computer gaming and animation.

Based on pore-scale images from a wide range of organic shales, it can be seen that organic material is present in a variety of forms. Three primary forms of organic matter are commonly observed; non-porous, spongy, and pendular. Non-porous organic components fill all of the available non-mineral space leaving virtually no porosity or fluid flow path. Porous or "spongy" organic material is commonly encountered in thermally mature gas shales. Pendular organic material appears to fill the small inter-granular and grain contact regions, leaving open pore space in the larger voids. These pore types are largely controlled by kerogen type and thermal maturity, and they exert large influence on the porosity, permeability, and overall shale reservoir quality.
3D Seismic as an Aid to Design Syngas Production by Means of Underground Coal Gasification (UCG) Methodolgy
Authors: du Plooy Dries , Szanyi Béla , Mázik Jeno , Majoros Péter , Tóth Támas , Kádi Zoltán , Koroknai Balázs
Published: March 2012

The unconventional use of coal to supplement Natural Gas (NG) in the power and chemical industry makes Underground Coal Gasification (UCG) an important technology in economically producing unconventional gas. Present day exploration and production technologies pave the way "from a potential to actual production".

A 3D seismic survey has been applied in Southern Hungary for the site selection of UCG resource blocks, as well as in the design of the most optimal exploration drilling program. The latter exploration techniques directional drilled injection and production wells are planned in the coal seams to sustain the burning front.

Wildhorse UCG Kft is a pioneer in the design and introduction of the environmentally friendly coal based syngas for electric power generation in East-Central European countries. Additionally the syngas can be utilised to supplement national gas supplies as alternative fuel gas. In this presentation the role of 3D seismic is discussed in defining the "Mecseknádasd UCG project".

Wildhorse UCG Kft completed 3D seismic measurements in April and May of 2011 in the Mecseknádasd UCG project area. The goal of the seismic measurements is to image and clarify the structural conditions and to reveal faults and other discontinuities in the coal formation explored previously by historic deep drilling in the area.

The processing and interpretation of the survey results have been performed together by GEOMEGA Kft and Wildhorse UCG Kft and the presentation covers the complete survey results of the Mecseknádasd UCG exploration project: –Newly processed results of historical boreholes–Results of the seismic survey–Geological and geophysical results of new boreholes–Possibilities for upgrading the geological model with integrated interpretation by using the available geophysical data (seismic, new boreholes, historic boreholes)–The possibilities for the application of 3D seismic survey in the design process of the UCG technology and to monitor the UCG engineering process
European Shale Gas, Getting Buy-in From the Public and Stakeholders
Authors: Miller Mark A. , Vaughan Eric
Published: March 2012

During the past 10 years shale gas development projects have proven to be highly successful in a number of North American basins, and have become a game changer for the energy supply there. Because of these successes, shale gas exploration and development technologies are being deployed around the globe, including Europe. But while there appears to be vast shale gas resources across Europe, many industry analysts express concerns about the probability of repeating the North American successes in Europe. These concerns are based on the denser population in Europe, different safety and environmental regulations, and the doubts of many European residents about the overall safety of shale gas development. Moreover, unlike North America where landowners often are entitled to significant lease payments and royalties for their mineral rights, the mineral rights throughout most of Europe are owned by the governments, rather than the landowners. The combination of these factors adds to the difficulty of building public support for a shale gas program.

This paper provides a discussion of a shale gas exploration program currently being conducted by Cuadrilla Resources in England. It examines the concerns of the local residents, and how these have affected media coverage, and support (or opposition) from politicians. It discusses the strategy and approach used by Cuadrilla for addressing questions and concerns from the local residents, various UK regulatory bodies, politicians and the media. While this paper focuses on a UK shale gas case, the conclusions and recommendations are applicable to any shale gas program in Europe or elsewhere.
Near Balance Drilling Benefits Addressed Through a Blowout Probability Model
Authors: Molaschi Claudio , Masi Silvia , Zausa Fabrizio , Rossi Nicola , Michelez Jean
Published: March 2012

Eni Near Balance Drilling (e-nbd™) is an innovative drilling process to maintain constant bottom hole annular pressure at all times while circulating, and to manage annular dynamic hydraulic pressure profile accordingly. The operational benefits of this process are measured on field operations through the enhancement of borehole quality, the reduction of NPT and the ability to reach targets otherwise inaccessible.

e-nbd™ can improve drilling operations safety, especially by reducing the probability of the most significant threats, which is a blowout event. These benefits are not measurable on operations, unless having a huge number of statistical records.

Nonetheless the probability of a complex event like a blowout can be effectively calculated through dedicated fault tree models.

Eni drilling department has developed a replicable blowout probability model that is suitable for most of the current drilling and completion situations. This model is offering a high number of possible operating scenarios and detailed settings, in order to guarantee the accuracy of each analysis.

This model has been used to address the benefits of e-nbd™, in order to compare analogous wells to be drill with or without e-nbd™. In both situations results were analysed to measure the overall impact on blowout probability and to further address the sensitivity to technical / non technical factors.

By comparing two situations using a probabilistic fault tree, this paper shows that the key factors affecting a blowout probability are notably impacted by the use of e-nbd™. These key factors are not only technical, but also organizational and human.
Report from the United States: The U.S. Health Crisis Deepens amid Rising Inequality—A Review of Data, Fall 2011
Authors: Hellander Ida , Bhargavan Rohith
Published: March 2012

This report presents information on the state of the U.S. health system in late 2011. The authors include data on the uninsured and the underinsured and their access to health care, socioeconomic inequality in care, the rising costs of the U.S. health system, and the role of corporate money in health care, with special reference to the pharmaceutical industry and the hospice industry. They also provide updates on Medicaid and Medicare and on the new federal health care law. Some information on health care systems elsewhere in the world is also included.
Evacuation Criteria after a Nuclear Accident: A Personal Perspective
Authors: Wilson Richardh
Published: March 2012

In any decision involving radiation a risk-risk or risk-benefit comparison should be done. This can be either explicit or implicit. When the adverse effect of an alternate action is less than the planned action, such as medical use of X rays or nuclear power in ordinary operation, the comparison is simple. But in this paper I argue that with the situation faced by the Japanese in Fukushima, the assumption that the risk of an alternate action is small is false. The risks of unnecessary evacuation exceeded the risk of radiation cancers hypothetically produced by staying in place. This was not realized by those that had to make a decision within hours. This realization suggests important changes, worldwide, in the guidelines for radiation protection in accident situations.
Extreme Sensitivity and the Practical Implications of Risk Assessment Thresholds
Authors: Bukowski John , Nicolich Mark , Lewis R. Jeffrey
Published: March 2012

Traditional risk-assessment theory assumes the existence of a threshold for non-cancer health effects. However, a recent trend in environmental regulation rejects this assumption in favor of non-threshold linearity for these endpoints. This trend is driven largely by two related concepts: (1) a theoretical assumption of wide-ranging human sensitivity, and (2) inability to detect thresholds in epidemiologic models. Wide-ranging sensitivity assumes a subpopulation with extreme background vulnerability, so that even trivial environmental exposures are hazardous to someone somewhere. We use examples from the real world of clinical medicine to show that this theoretical assumption is inconsistent with the biology of mammalian systems and the realities of patient care. Using examples from particulate-matter air-pollution research, we further show that failure to reject linearity is usually driven by statistical rather than biological considerations, and that nonlinear/threshold models often have a similar or better fit than their linear counterparts. This evidence suggests the existence of practical, real-world thresholds for most chemical exposures.
Commentary on the Appropriate Radiation Level for Evacuations
Authors: Cuttler Jerry M.
Published: March 2012

This commentary reviews the international radiation protection policy that resulted in the evacuation of more than 90,000 residents from areas near the Fukushima Daiichi NPS and the enormous expenditures to protect them against a hypothetical risk of cancer. The basis for the precautionary measures is shown to be invalid; the radiation level chosen for evacuation is not conservative. The actions caused unnecessary fear and suffering. An appropriate level for evacuation is recommended. Radical changes to the ICRP recommendations are long overdue.
Ubiquitin-Specific Protease 2 Regulates Hepatic Gluconeogenesis and Diurnal Glucose Metabolism Through 11β-Hydroxysteroid Dehydrogenase 1
Authors: Molusky Matthew M. , Li Siming , Ma Di , Yu Lei , Lin Jiandie D.
Published: March 2012

Hepatic gluconeogenesis is important for maintaining steady blood glucose levels during starvation and through light/dark cycles. The regulatory network that transduces hormonal and circadian signals serves to integrate these physiological cues and adjust glucose synthesis and secretion by the liver. In this study, we identified ubiquitin-specific protease 2 (USP2) as an inducible regulator of hepatic gluconeogenesis that responds to nutritional status and clock. Adenoviral-mediated expression of USP2 in the liver promotes hepatic glucose production and exacerbates glucose intolerance in diet-induced obese mice. In contrast, in vivo RNA interference (RNAi) knockdown of this factor improves systemic glycemic control. USP2 is a target gene of peroxisome proliferator–activated receptor γ coactivator-1α (PGC-1α), a coactivator that integrates clock and energy metabolism, and is required for maintaining diurnal glucose homeostasis during restricted feeding. At the mechanistic level, USP2 regulates hepatic glucose metabolism through its induction of 11β-hydroxysteroid dehydrogenase 1 (HSD1) and glucocorticoid signaling in the liver. Pharmacological inhibition and liver-specific RNAi knockdown of HSD1 significantly impair the stimulation of hepatic gluconeogenesis by USP2. Together, these studies delineate a novel pathway that links hormonal and circadian signals to gluconeogenesis and glucose homeostasis.
Risk of Parkinson Disease Onset in Patients With Diabetes
Authors: Sun Yu , Chang Ya-Hui , Chen Hua-Fen , Su Ying-Hwa , Su Hui-Fang , Li Chung-Yi
Published: March 2012

OBJECTIVE

We retrospectively assessed the age- and sex-specific incidence and relative risk of Parkinson disease (PD) in Taiwan’s diabetic population.

RESEARCH DESIGN AND METHODS

Study cohort included 603,416 diabetic patients and 472,188 nondiabetic control subjects. Incidence rate and relative risk of PD (ICD-9-CM 332.0) were evaluated.

RESULTS

The incidence of PD was 3.59 and 2.15 per 10,000 person-years for the diabetic and control group, respectively, representing a covariate adjusted hazard ratio (HR) of 1.61 (95% CI 1.56–1.66), which was substantially reduced to 1.37 (1.32–1.41) after adjusting for medical visits. Diabetes was associated with a significantly elevated risk of PD in all sex and age stratifications except in young women, with the highest HR noted for young men aged 21–40 years (2.10 [1.01–4.42]), followed by women aged 41–60 (2.05 [1.82–2.30]) and >60 years (1.65 [1.58–1.73]).

CONCLUSIONS

Diabetes is associated with an increased risk of PD onset in a Chinese population, and the relation is stronger in women and younger patients.
Colesevelam Improves Oral but Not Intravenous Glucose Tolerance by a Mechanism Independent of Insulin Sensitivity and β-Cell Function
Authors: Marina Anna L. , Utzschneider Kristina M. , Wright Lorena A. , Montgomery Brenda K. , Marcovina Santica M. , Kahn Steven E.
Published: March 2012

OBJECTIVE

To determine the mechanism by which the bile acid sequestrant colesevelam improves glycemic control.

RESEARCH DESIGN AND METHODS

We performed a frequently sampled intravenous glucose tolerance test (FSIGT) with minimal model analysis and a meal tolerance test (MTT) in 20 subjects with impaired fasting glucose (11 men, 9 women; mean age 60.7 ± 1.9 years, BMI 29.4 ± 0.9 kg/m2) in a single-blind study after 2 weeks of placebo treatment and 8 weeks of colesevelam 3.75 g daily. From these tests, insulin sensitivity, β-cell function, and glucose tolerance were determined, along with gastrointestinal peptide levels during the MTT.

RESULTS

Fasting plasma glucose and HbA1c decreased with colesevelam (from 5.9 ± 0.1 to 5.7 ± 0.1 mmol/L, P < 0.05, and from 5.86 ± 0.06 to 5.76 ± 0.06%, P = 0.01, respectively), but fasting insulin did not change. Colesevelam had no effect on any FSIGT measures. In contrast, the MTT incremental area under the curve (iAUC) for both glucose (from 249.3 ± 28.5 to 198.8 ± 23.6 mmol/L ⋅ min, P < 0.01) and insulin (from 20,130 [13,542–35,292] to 13,086 [9,804–21,138] pmol/L ⋅ min, P < 0.05) decreased with colesevelam. However, the ratio of iAUC insulin to iAUC glucose was not changed. iAUC for cholecystokinin (CCK) increased (from 43.2 [0–130.1] to 127.1 [47.2–295.2] pmol/L ⋅ min, P < 0.01), while iAUC for fibroblast growth factor 19 decreased (from 11,185 [1,346–17,661] to 2,093 [673–6,707] pg/mL ⋅ min, P < 0.01) with colesevelam. However, iAUC for glucagon, glucose-dependent insulinotropic peptide, and glucagon-like peptide 1 did not change.

CONCLUSIONS

Colesevelam improves oral but not intravenous glucose tolerance without changing insulin sensitivity, β-cell function, or incretins. This effect may be at least partially explained by the colesevelam-induced increase in CCK.
Maternal Enterovirus Infection as a Risk Factor for Type 1 Diabetes in the Exposed Offspring
Authors: Viskari Hanna , Knip Mikael , Tauriainen Sisko , Huhtala Heini , Veijola Riitta , Ilonen Jorma , Simell Olli , Surcel Heljä-Marja , Hyöty Heikki
Published: March 2012

OBJECTIVE

Maternal enterovirus infections during pregnancy have been linked to an increased risk of type 1 diabetes in the offspring. The aim of this study was to evaluate this association in a unique series of pregnant mothers whose child progressed to clinical type 1 diabetes.

RESEARCH DESIGN AND METHODS

Maternal and in utero enterovirus infections were studied in 171 offspring who presented with type 1 diabetes before the age of 11 years and in 316 control subjects matched for date and place of birth, sex, and HLA-DQ risk alleles for diabetes. Acute enterovirus infections were diagnosed by increases in enterovirus IgG and IgM in samples taken from the mother at the end of the first trimester of pregnancy and cord blood samples taken at delivery.

RESULTS

Signs of maternal enterovirus infection were observed in altogether 19.3% of the mothers of affected children and in 12.0% of the mothers of control children (P = 0.038). This difference was seen in different HLA risk groups and in both sexes of the offspring, and it was unrelated to the age of the child at the diagnosis of diabetes or the age of the mother at delivery.

CONCLUSIONS

These results suggest that an enterovirus infection during pregnancy is not a major risk factor for type 1 diabetes in childhood but may play a role in some susceptible subjects.
Forecasting the Effects of Investments in Knowledge-Workers in the SME Sector, Using the GMDH Method
Authors: Patalas-Maliszewska Justyna , Krupa Tadeusz
Published: March 2012

Forecasting the Effects of Investments in Knowledge-Workers in the SME Sector, Using the GMDH Method

The enterprises functioning in market economy have to implement changes in systems of organization and management that they use. In economy practice making a decision in enterprise is conditioned by competitors' action, changing factors of environments, e.g. technical progress and results of the research works. Added value for SME can be determine as knowledge, employees' skills and abilities, social relation, know-how, and particularly effective investing in intellectual capital. The enterprises which invest in knowledge and systems of work are achieved competitive advantage, because of their workers' readiness to learning and qualifying themselves and also thanks to effective information and communication transfers. In this paper we allowed to respond to the following question: whether a given algorithm that enables the characteristics of the knowledge-workers and the expected results of expenditures on the intellectual capital (potential benefits from investing in the knowledge-workers) binding? This paper presents prediction effects of investments in knowledge-workers in the SME sector when using the neural systems GMDH basing on the Ivachnienko algorithm.