bluuebunny/crossref_metadata_2025 huggingface dataset:
Reliability Based Approach for Estimating The Fatigue Damage
Authors: Surendran Vasudevan , Rahayem Mohamed
Published: November 2015

Subsea diver-less connections in general are not subjected to fatigue load. By principle, they don't require a fatigue analysis, however, due to some uncertainties in field like slugging causes damage to these structures. Since these structures are not designed for fatigue, it is important to check its resistance and understand remaining strength when such phenomenon happens. The paper discusses about estimating the fatigue damage due to slugging phenomena which is a high frequency phenomena using combination of finite element and analytical solution. The loading action on the structure could be combination of axial force, transverse force and bending moment. The remaining fatigue life can then be estimated based on Miners rule. The paper also discusses about the probabilistic approach where variations in loading, material curve and Miners limit is considered to qualitatively understand safety of system for remaining service. For probabilistic analysis, reliability tools like Weibull analysis is used to assess the change in reliability of component and hence establish the relative damage in structure. Based on linear extrapolation of accumulated damage, using Miner rule based on DNV RP C203, the remaining life was estimated to be 9.69 years compared to 40 years of design life. However, the probabilistic approach is adopted to showcase that the slugging has lowered the reliability for fatigue failure of the critical component has dropped by less 20% for 9.69 years. The observation has led to increased confidence in operating the system in spite of accumulated damage. The approach presented in the paper can be used by the industry to understand the risk involved instead of taking decision based on remaining life computed using deterministic approach. The reliability based approach provides a qualitative assessment of extent of damage and hence assists in making a decision for risk based inspection and replacement.
Application of Dead Oil Viscosity for Water Shut-Off Job Designs in Reservoirs with Biodegradation: A Case Study of Bhagyam Field
Authors: Agrawal Nitesh , Mishra Lokranjan , Ghosh Priyam , Samal Saphalata , Priya Pachauri
Published: November 2015

This paper demonstrates a novel technique of tracking water entry zones, which has been used with a good success rate in Bhagyam field. Bhagyam field is located in the state of Rajasthan, India and is a part of the prolific Barmer Basin. Oil Production from Bhagyam field has shown steep decline as the water cut increased sharply. The reason for the increase in water cut can be largely attributed to adverse mobility ratio and limited volumetric pump capacities which limit drawdown. The excess water not only has reduced oil rates but also increased liquid volumes at the processing terminal. In order to control operating costs and increase oil production, it was of paramount importance for the operator to carry out water shut off jobs as a measure to reduce the undesirable water production.

This paper illustrates firstly a systematic approach on how the water entry zones are identified with the help of dead oil viscosity data and secondly describes a few case histories of water shut off jobs. Mechanical water shut off techniques were used to isolate bottom watered out sands temporarily. Retrievable bridge plugs were installed above the watered out zones during work-overs to increase drawdown on other sands and increase oil recovery. Using this methodology, four water shut off jobs were executed successfully in FY 2014–15 which led to significant reduction in water production and subsequent increase in oil production.
Reliability Analysis of Strength of Offshore Jackets in Indian Western Offshore
Authors: Singh Divjot , Panneerselvam N , Kumar Dinesh
Published: November 2015

Structural Reliability Analysis (SRA) is a method for estimating the reliability or probability of failure of a structure, a structural member, or a structural element. This analysis is in turn based on a physical model which represents both the load and resistance of the system. An offshore jacket is analysed for structural reliability and the major load on the jacket is found to take a parametric equation proportional to the maximum wave height impeding the platform. Reserve Strength Ratio (RSR) is used as a general term to describe the resistance of the system. Probability of failure of the structure is then calculated using FORM/SORM using MATLAB for different assumed values of RSR, and acceptance criteria of RSR for west coast of India is also discussed.
Case History: Largest Hydraulic Fracturing Jobs of India in KG Basin and Successful Production Test with Underbalanced Slim Hole Selective Completion in HPHT Environment
Authors: Pathak Shashank , Ranjan Vishal , Tiwari Shobhit , Ranjan Amit , Tripathi Archit , Nagar Ankesh , Singh Atul , Tibbles Raymond , Goyal Rajat
Published: November 2015

An appraisal well in the KG Onshore Block (a joint venture of Cairn India Ltd and ONGC) has provided key engineering and operational learning's. The objective of this well was to appraise two separate low permeability reservoirs (~ 0.1md) which are ~4300m deep and falls under HPHT conditions. Due to their low permeability; hydraulic fracturing was necessary to verify the production potential of these reservoirs. To cater this, the discovery well was re-designed and sidetracked so that it could handle the expected fracturing loads. Hydraulic fractures (~387,000 lbs of Proppant); biggest in terms of proppant placed in any single stage in India, were executed and then the well was completed with slim-hole selective completion in challenging underbalanced conditions to test these reservoirs selectively.

This paper primarily talks about the key constraints while planning and designing this well and then deals in detail on the learnings while executing this unique completion operation. Details on the fracturing design were already covered by Barasia et al. in SPE-171421-MS. The paper concludes with production results and the key reasons which led to ~7 fold increase with respect to previous appraisal well, as observed while production testing.
Innovative Completion Approach to Develop Unconsolidated Shallow and Thin Multi-Layered Gas Reservoir: A Case Study of North Tapti Field
Authors: Ahmad S. S. , Pradhan S. P. , Sarkar S. De , Sengupta S. , Bhattacharya V. K.
Published: November 2015

The North Tapti field is located in Arabian Sea WNW of Mumbai city. The bathymetry of the area is very shallow between 8-35 m depending on the tide condition and therefore poses adverse logistic conditions due to strong bottom currents. In North Tapti field shallow gas sands of Oligo-Miocene age occurring at depth of 550- 900 m are layered reservoir with several pays. Exploratory wells produced dry gas with sand. The lithology of the reservoir sand is mainly medium to fine grained and at places coarse sandstone with fair inter-granular porosity.

Initial development plan envisaged exploitation of gas through six development wells. All the six wells were envisaged as horizontal wells of about 300m drain hole with sand control completions through pre- drilled liner supported open hole gravel packs with a view to achieve higher gas productivity. The rig positioning activity in North Tapti area experienced great difficulties due to severe sand-scouring of seabed. Therefore, the first well had to be drilled as vertical well and completed with premium screen as a standalone screen completion with a view to make up lost time prior to impending monsoon. Studies based on the drilling data obtained from first development well revealed sub- surface surprises like reduction in pay thickness and occurrence of multi layered pays in Mahim and Daman formations at shallow depth. This posed considerable challenges in achieving desired high drift at shallow vertical depth of about 400m while maintaining high angle trajectory during drilling and subsequent completion programme. Hence, innovative drilling and completion approaches were adopted to tackle sub-subsurface complixities and to achieve maximum planned gas production.

In this backdrop of accomplishing the onerous task to produce sand free gas in all the six wells in platforms of North Tapti which were planned to be completed with suitable sand control methode using in-house expertise was a real challenge. The methodology adopted in two wells viz. A and B of 80° and 85° inclination were single frac pack and stacked completion of both. Stand alone in the lower barefoot section and a frac pack in the upper sands which was cased cemented and perforated. The wells of P1 platform are accessible with difficulty due to severity of water depth and short tide periods. Therefore wells were completed as stand-alone screen completions through Expandable Sand Screen (ESS) in 6″ drain hole section and 7″ liner sections.

This highly innovative drilling and completion approach facilitated exposure and completion of thin pay sands in multi-layered reservoirs in a deviated well. The result is stable and uninterrupted gas production for over a period of more than two and half years and continuing at a consistent rate of about 1.3 MMm3/d.
Workflow to Optimize Field Development Strategy and Maximize Recovery of a Shale Play
Authors: Sahoo Ajit K. , Biswal D. , Mukherjee A. , Srivastava M.
Published: November 2015

Due to the ultra-low permeability in shale reservoirs, hydraulic fracturing is necessary to provide secondary permeability to increase production in horizontal wells. Well spacing is a key factor in maximizing recovery of a shale reservoir. At the same it is important to understand the effective drainage area and the inherent reservoir quality to optimize the development strategy. In this paper, a workflow has been described to optimize field development strategy and maximize recovery of a shale play by integrating microseismic, DFN, tracer data and high frequency stratigraphic characterization.

In the first section, fracture geometry for the primary horizontal wells was estimated from microseismic data, tracer data and discrete fracture network model to establish the frac half-length, frac height and effective drainage area. From all these studies, it was observed that the hydraulic fractures of the primary wells are not able to drain the entire shale reservoir and a major portion of the reservoir remains un-drained. This analysis brought out an initial understanding about the requirement of staged lateral to exploit the un-drained reservoir section.

In the second section, various reservoir parameters were integrated with normalized well performance to capture the subsurface drivers that control the well productivity. Based on these critical drivers and gas in place, the above described un-drained reservoir portion was assessed to ensure its potential be a separate target.

In the last section, we have illustrated the importance of lateral placement through high frequency stratigraphic characterization. This analysis indicated that to maximize the well performance or recovery we need to place the lateral within the best part of the reservoir.

The illustrated workflow in this paper helps in deciding the optimum number of wells required to maximize field recovery. This study also helps in understanding the role of lateral placement in enhancing the well performance. This workflow can be applied to any shale plays which are in the initial stage of their development phase to understand if there is any scope of improvement in ongoing development strategy.
Channel Fracturing Technique Helps to Revitalize Brown Fields in Langepas Area
Authors: Valiullin Albert , Makienko Vladimir , Yudin Alexey , Overin Alexandr , Gromovenko Alexandr
Published: November 2015

Paper describes in details a trial campaign with channel fracturing technique and it's positive effect on operational reliability and wells productivity that helped to revitalize brown Urevskoe oil field.

Main challenges of the Jurassic formation are low permeability and high heterogeneity. Hydraulic fracturing is required for economic wells exploitation. Historically, hydraulic fracturing in oil fields close to the city of Langepas was developing towards aggressive designs with cleaner fractures, although increased risk of premature screenouts is encountered with such approach. To further improve efficiency and economics of stimulation treatments, a logical step in conductivity enhancement was made implementing channel fracturing technique. Channel fracturing allows for heterogeneous proppant placement leaving open channels inside proppant pack. Thus, conductivity of the system increases significantly. Channels also help to better clean out fracture from fluids and polymers increasing an effective fracture half-length, which is a goal in low-permeability formations. Another important advantage of the new technique is minimized risk of screenouts.

Campaign was made implementing the technique to re-stimulate wells in brown Urevskoe oil field in Langepas area. Open channels showed reliable production increase from old wells in depleted regions. Proppant flowback is a common problem in such conditions and was encountered in many offset wells, therefore channel fracturing was enhanced by rod-shaped proppant at the tail-in stage. Such combination allowed preventing proppant flowback issues and improved conductivity in near-wellbore zone.

Worldwide, this trial campaign is one of the pioneering re-stimulation projects implementing channel fracturing. Comprehensive analysis of performed operation, production comparative results and lessons learnt will make it possible to successfully extend the use of innovative technologies to many other brown fields that require stimulation.
Productivity Enhancement and Optimization in High Sour Gas Field by Selective Stimulation through Post Perforation Dynamic Underbalance Technique and Production Logging
Authors: Agrawal G. , Kumar A. , Verma V. , Mishra A. , Deori B. , Kaushik Y. D. , Gyani O. N. , Baishya R. C. , Shankar R. , Singh B.
Published: November 2015

XYZ, a marginal carbonate field in Western Offshore India was undertaken for development recently. During its exploration phase, around two decade ago, thick oil layer was discovered with high sour gas content (around 14000 ppm). The reservoir was delineated in small oil pool, where six wells were completed for production, including one water injector for pressure maintenance to support oil recovery. Production behavior of most of the wells had a unique response of rapid decline in short period of time with similar drastic loss in THP without any change in water cut. Production response of all these wells led the suspicion of near well bore skin development as the primary reason behind sharp decline in production.

Acid treatment as a quick fix solution in carbonates was ruled out because of possible communication with bottom aquifer; coil tubing had multiple operational challenges in such a high H2S environment. Hence, to overcome the challenges and perform root cause analysis, it was planned to carry out the best possible set of data acquisition with rigless operations and plan ahead for productivity improvement and design future intervention as well.

Production Logging, being an ideal diagnostic tool, was chosen to study the production profile and understand the reservoir and well behavior. Post analysis, a relatively new concept of selective stimulation with post perforation controlled dynamic underbalance technique was considered to be the best fit solution to address the skin and production decline problem in the field.

The technique proved to be very beneficial and provided substantial increase in the wells production. The skin debris obtained in the process were analyzed to identify the cause of skin development and production plunge. Based on the results, further interventions were carried out in the well, which again proved to be very efficacious and increased the field production significantly.

The paper has a detailed discussion on the root cause analysis and arriving to the appropriate solution for this kind of wells. It emphasizes on the importance of production logging prior to operation for better and successful planning and execution of the well intervention jobs leading to production gain. It also highlights the operational challenges in such hostile high H2S environment and the importance of planning and preparation to ensure safety of one and all.
Optimization of Hydraulic Fracturing Technology Application for Value Enhancement: A Case Study from Raageshwari Deep Gas Field
Authors: Gupta A. K. , Shankar P. , Saurav S. , Verma S. K. , Mund B.
Published: November 2015

The Raageshwari Deep Gas Field, Barmer Basin, India is a low permeability, moderate CGR gas condensate reservoir. It is a low net to gross system with gross reservoir thickness varying from 500-1000m. The pay zone consists of a poorly sorted sandstone interval on top of a stacked volcanic succession of thick lava flow cycles. The wells have been completed with multi-stage hydraulic fracture stimulations to allow production at economical rates.

The major challenge is to improve fracture placement to achieve wellbore connection with the entire net reservoir storage and flow capacity. Connecting each and every net reservoir packet would increase the number of fracture stages and in turn increase the cost significantly. Thus an optimization workflow was generated to increase the efficiency of hydraulic fracturing and reduce the cost of connecting the maximum net reservoir through hydraulic fractures.

An integrated approach including petrophysical and geomechanical analyses was used to identify the potential zones for hydraulic fracturing. Fracturing technologies like limited entry technique using cluster perforation were used to increase the net connected reservoir thickness while employing as few fracture stages as possible. Several post fracturing data acquisition programmes were conducted to estimate fracture parameters such as fracture height, half-length and conductivity to help evaluate the performance of each fracture stage. Single well analytical and numerical models were developed to estimate the impact of connecting maximum net reservoir thickness in terms of both initial production rate (IP) and the expected ultimate recovery (EUR) of the reservoir.

The limited entry fracturing technique with cluster perforation used in several wells was helpful in connecting the maximum net reservoir in the thick gross pay sections present. Based on a cost-benefit analysis, the number of fracture stages for each well was optimized with the goal of connecting the maximum net reservoir thickness to the wellbore. The fracture height achieved in each fracture stage was verified through micro-seismic, RST and temperature log measurements and pressure transient analyses. Once the height was ascertained, other parameters were obtained from post-fracturing pressure matches and pressure build up data. The estimated impact of connecting the maximum net reservoir storage and flow capacity as compared with the initial plan of 4-5 conventional single perforation hydraulic fractures is estimated to be production of ~5% GIIP in 15 years.
Mainstream Smoke Chemistry and in Vitro and In Vivo Toxicity of the Reference Cigarettes 3R4F and 2R4F
Authors: Roemer E , Schramke H , Weiler H , Buettner A , Kausche S , Weber S , Berges A , Stueber M , Muench M , Trelles-Sticken E , Pype J , Kohlgrueber K , Voelkel H , Wittke S
Published: November 2015

A new reference cigarette, the 3R4F, has been developed to replace the depleting supply of the 2R4F cigarette. The present study was designed to compare mainstream smoke chemistry and toxicity of the two reference cigarettes under the International Organization for Standardization (ISO) machine smoking conditions, and to further compare mainstream smoke chemistry and toxicological activity of the 3R4F cigarette by two different smoking regimens, i.e., the machine smoking conditions specified by ISO and the Health Canada intensive (HCI) smoking conditions.

The in vitro cytotoxicity and mutagenicity was determined in the neutral red uptake assay, the Salmonella reverse mutation assay, and the mouse lymphoma thymidine kinase assay. Additionally, a 90-day nose-only inhalation study in rats was conducted to assess the in vivo toxicity. The comparison of smoke chemistry between the two reference cigarettes found practically the same yields of total particulate matter (TPM), ‘tar’, nicotine, carbon monoxide, and most other smoke constituents. For both cigarettes, the in vitro cytotoxicity, mutagenicity, and in vivo toxicity showed the expected smoke-related effects compared to controls without smoke exposure. There were no meaningful differences between the 2R4F and 3R4F regarding these toxicological endpoints. The assessments for the 3R4F cigarette by smoking regimen found as a trivial effect, due to the higher amount of smoke generated per cigarette under HCI conditions, an increased yield of toxicant and higher toxicological activity per cigarette. However, per mg TPM, ‘tar’, or nicotine, the amounts of toxicants and the in vitro toxicity were generally lower under HCI conditions, but the in vivo activity was not different between the two machine smoking conditions. Overall, as the main result, the present study suggests equivalent smoke chemistry and in vitro and in vivo toxicity for the 2R4F and 3R4F reference cigarettes.
Nitrogen Fertilization for Optimizing the Quality and Yield of Shade Grown Cuban Cigar Tobacco: Required Nitrogen Amounts, Application Schedules, Adequate Leaf Nitrogen Levels, and Early Season Diagnostic Tests
Authors: Borges A , Morejón R , Izquierdo A , Ortega E , Rodés R
Published: November 2015

Nitrogen (N) fertilizers have a decisive influence on the yield and quality of tobacco. Yield, percentage of plant N, wrapper leaf quality, and nicotine content are all important quality characteristics in tobacco growing. This work is an attempt to provide a tool for optimizing mineral N nutrition for Cuban cigar tobacco, using a strategy that links N supply with leaf N concentration and wrapper yield. Similar approaches developed worldwide have mainly involved Virginia and Burley tobacco types but not Cuban cigar tobacco. The objective of the current work is to identify the effects of fertilizer N levels and timing of application on each of the mentioned quality factors for shade grown Cuban cigar tobacco. Another purpose is to explore the usefulness of a quick method of assessing the N status of plants based on measuring leaf transmission at two different wavelengths (650 and 940 nm). The experiments were done in the main tobacco growing area of Cuba (Vueltabajo). In each experiment, nine separate treatments were used covering different levels and times of fertilizer N application. The same experiment was carried out in three different years (2005-2006, 2006-2007, 2007-2008) but as the results were similar only one set of data is described (2006-2007). The patterns of response to N fertilizer of all four quality measurements, including yield and wrapper leaf quality, were similar in the different replications of the experiments. The optimal fertilizer level was 140-190 kg N/ha (40% applied on days 8-10 after transplanting and 60% on days 18-20 after transplanting). The optimal N concentration of leaves taken at the central foliar level of the middle stalk position was 4.3-4.7% at harvest time. Leaf transmission measurements by means of the SPAD-502 Chlorophyll Meter in the early stages of growth were correlated with leaf chlorophyll and N concentration and provide an excellent guide for predicting Cuban cigar tobacco wrapper leaf yield.
Arsenic Speciation in Tobacco and Cigarette Smoke
Authors: Liu C , Wright CG , McAdam KG , Taebunpakul C , Heroult J , Braybrook J , Goenaga-Infante H
Published: November 2015

Arsenic is one of the metals found in cured tobacco and mainstream cigarette smoke. Levels of arsenic in modern filtered cigarette smoke range from sub-ppm to a few tens of ppms. To enable accurate smoke toxicity assessment on arsenic in cigarette smoke, it is desirable to establish its chemical forms in addition to total quantities because different arsenic compounds possess different toxicological potentials.

Progress has been made on measuring the arsenic speciation in tobacco and mainstream cigarette smoke by using a combination of synchrotron-based X-ray absorption spectroscopy and high-performance liquid chromatography- inductively coupled plasma mass spectrometry (HPLC-ICP-MS). In this paper, we describe the experimental procedures developed together with the main findings. A transient redox transformation between As(V) and As(III) was confirmed in freshly generated mainstream smoke. Potential areas for future research are highlighted in order to further our understanding of the speciation mechanism for arsenic in tobacco products.
Influence of Additives on Cigarette Related Health Risks
Authors: Klus H , Scherer G , Müller L
Published: November 2015

Tobacco additives play an important role in the manufacturing and for the quality of tobacco products, particularly cigarettes and roll-your-own tobaccos. Attention is increasingly given to the potential effects of additives on consumer behavior and health. This review is intended to compile, collate and - to some degree - evaluate the wealth of pertinent scientific information available from the published literature and other special sources. At first, the reasons are set forth for the use of additives in cigarette manufacturing. In response to the growing controversy over the attractiveness and addictiveness of smoking, the clarification of terms and concepts is followed by a detailed discussion of two kinds of substances with particular relevance: Additives like ammonium compounds that are claimed to increase nicotine availability, and additives that are claimed to increase nicotine addictiveness.

The composition and toxicity of mainstream smoke of cigarettes with and without additives are assessed in several respects. The potentials of pyrolysis studies are explored by looking at a number of key studies and some basic considerations regarding in vitro and in vivo toxicity testing are addressed. Five major literature reviews on additives published between 1994 and 2004, and the results of several comprehensive experimental studies covering a large range of additives, released between 2002 and 2012, are dealt with in detail. Single tobacco additives of particular importance (menthol, glycerol, 1,2-propylene glycol, sorbitol, sugars, cocoa, licorice, citric acid, triacetin, and ammonium compounds) are discussed in dedicated chapters, which are generally subdivided into special sections: Use and toxicological assessment; inclusion level in cigarettes, transfer and pyrolysis; attractiveness and addictiveness; effect on cigarette mainstream smoke composition; effect on cigarette mainstream smoke toxicity. Epidemiological findings and data obtained by the biomonitoring of smokers consuming cigarettes with and without additives are compiled and interpreted specifically for American blend cigarettes, Virginia cigarettes, “French” (dark) cigarettes and menthol cigarettes whereby the focus is on the effects of additives on smoking topography and potential health risks.

Opinionated reviews were published in recent years that are compromised by arbitrary selection of sources and unbalanced views. Leaving those unconsidered, the aggregated scientific knowledge shows that tobacco additives have only occasional and limited effects on cigarette mainstream smoke composition, which are almost never reflected in the results of toxicological in vitro assays or in vivo studies. This supports the conclusion that tobacco additives are not likely to increase the known health risks of smoking. There is also no evidence for sustaining claims that certain additives increase nicotine availability or nicotine addictiveness.
Editors’ Note
Authors: Heller WD , Scherer G
Published: November 2015

We were pleased to hear that a longstanding author to Beiträge had received the Tobacco Science Research ConferenceLifetime Achievement Award in 2012 - Dr Serban C. Moldoveanu. Dr Moldoveanu has published 21 papers in our journal. In 14 of these, he was the first author. The first article ofDr Moldoveanu was published in Beiträge in April 2000, the most recent will appear in this issue of Beiträge. We congratulate Dr SerbanModoveanu on being awarded the Tobacco Science Research Conference LifetimeAchievement Award in 2012. We as editors of BeiträgezurTabakforschung International are also a little proud that hehas chosen our Journal for publishing a major part of this tobacco-related work in his successful career. Please also readthe laudation by Dr Anthony R. Gerardi on pages 496 to 497.
Orthodontics in SAARC Countries: Emerging the Force within
Authors: Kharbanda Om Prasad
Published: November 2015

No abstract available.
Banding on Adolescents: Is Molar Band Height Different than Clinical Crown Height?
Authors: Kafle Dashrath , Agarwal Aradhana , Shrestha Sita , Adhikari Biplov
Published: November 2015

Introduction: Bonding of the teeth with brackets have eased the orthodontic procedure. However the bonding of molars is not very successful because of the occlusal force, difficulty in moisture control and age factor. Banding is usually the safe option which is again associated with gingival problems.

Objective: To compare the molar band height with that of adolescent maxillary molar height.

Materials & Method: A total of 33 maxillary adolescent casts and 30 average sized molar bands were retrieved from the orthodontic clinic of Kathmandu University Hospital. The height of the tooth as well as molar band were measured at 4 different points: mesio-buccal (MB), disto-buccal (DB), mesio-palatal (MP), disto-palatal (DP) and compared with independent t-test by SPSS software. p-value was kept at 0.01 for significance.

Result: There is no any statistical significant difference between the tooth and band heights at MB, DB and DP points. The difference is found on only one point MP which is statistically significant.

Conclusion: There is a need of separate molar bands for adolescent patients. The band dimension should be reduced occluso-cervically to avoid gingival impingement.
Comparative Cephalometric Analysis of Angle Class II Division 1 Malocclusion between Chinese Male and Female Subjects
Authors: Sharma Bishnu Prasad , Xin Chang
Published: November 2015

Objective: To compare the craniofacial features of male and female Chinese samples with Angle Class II Division 1 malocclusion.Materials & Method: The cephalometric radiographs were obtained from 39 Chinese subjects (mean age17.18 ± 7.1 years) with Angle Class II Division 1 malocclusion. Ten skeletal, nine dental and three soft tissue variables were investigated.Result: The craniofacial features between Chinese genders showed statistical significant differences among only one of the twenty-two variables studied.Conclusion: Chinese males have anteriorly long face compare to females.
Effect of Heat Sterilization on the Load/Deflection of Heat-activated Orthodontic Wires
Authors: Alavi Shiva , Mousavi Seyyed Mohammad , Shirban Farinaz
Published: November 2015

Introduction: Some of the orthodontic wires are heat-activated (H-A) wires; sometimes delivered in non-sterile packages and some of whose properties can be influenced by heat treatment.Objective: To assess the heat sterilization effects on the load/deflection (L/D) properties of H-A orthodontic wires before application.Materials & method: Three groups of H-A wires (3 cm length and 0.016 inches diameter) were selected; Group A: Nitinol H-A, Group B: H-A memory wire, Group C: Sentalloy H-A. Forty five samples of each type were prepared and randomly divided into three equal groups of 15 wires. Group 1 was selected as control, Group 2 was sterilized by dry heat (2 hours, 160°c) and Group 3 was sterilized using steam heat (15 PSI, 24 min, 121°c). A universal testing machine was used to determine the load/deflection curve of the samples while immersed in 37°c water bath using 3-bracket bending method. The force levels in loading plateau (LP) and unloading plateau (UP) were determined. One-way ANOVA and Duncan post-hoc were used for data analysis.Result: In group A, LP and UP showed no statistical significant change. In Group B, steam heat decreased LP and UP but dry heat increased UP significantly. In Group C, steam and dry heat decreased UP and LP significantly.Conclusion: It seems that heat sterilization could alter the L/D properties of some H-A wires depending on the type of wires and sterilization method.
Distribution of Malocclusion and Occlusal Traits among Tibetan Adolescents residing in Nepal
Authors: Karki Saujanya , Parajuli Umesh , Kunwar Nischal , Namgyal Kunsang , Wangdu Khamsum
Published: November 2015

Introduction: Malocclusion is the irregularity of teeth and is considered as oral health problem. Though etiology of malocclusion is multifactorial, it has considerable impact on the self esteem and social adjustment of an individual.Objective: To determine the prevalence of malocclusion and to assess the association between Angle classification of malocclusion and occlusal traits.Materials & Method: A cross sectional study was conducted among 138 Tibetan students of grade 8-12 were selected. Students with history of orthodontic treatment were excluded from the study. Data was recorded and analyzed using SPSS 17.0 and chi square test was used to evaluate the association between Angle classification of malocclusion and occlusal traits.Result: The prevalence of malocclusion was found to be Angle’s Class I (52.90%), Angle’s Class II (5.10%) and Angle’s Class III (9.40%). Occlusal traits such as overbite, increased overjet, openbite, crossbite, displacement and hypodontia was found to be 5.79%, 10.8%, 10.86%, 9.42%, 50,72% and 4.34% respectively.Conclusion: The prevalence of malocclusion among Tibetan adolescent was found to be higher. Hence, oral health awareness, preventive procedures and promotional programs need to be more emphasized.
A Review of Orthodontic Indices
Authors: Gupta Alka , Shrestha Rabindra Man
Published: November 2015

Orthodontic indices are essential component in assessing severity, complexity and treatment outcome of malocclusion. Moreover, they are useful in evaluating treatment need, funding for treatment cost and public health aspects of orthodontic treatment. The present article reviews orthodontic indices used for clinical and epidemiologic purposes. The article attempts to classify the indices in qualitative and quantitative methods
MRI-guided stereotactic radiofrequency thermocoagulation for 100 hypothalamic hamartomas
Authors: Kameyama Shigeki , Shirozu Hiroshi , Masuda Hiroshi , Ito Yosuke , Sonoda Masaki , Akazawa Kohei
Published: November 2015

OBJECT

The aim of this study was to elucidate the invasiveness, effectiveness, and feasibility of MRI-guided stereotactic radiofrequency thermocoagulation (SRT) for hypothalamic hamartoma (HH).

METHODS

The authors examined the clinical records of 100 consecutive patients (66 male and 34 female) with intractable gelastic seizures (GS) caused by HH, who underwent SRT as a sole surgical treatment between 1997 and 2013.

The median duration of follow-up was 3 years (range 1–17 years). Seventy cases involved pediatric patients. Ninety percent of patients also had other types of seizures (non-GS). The maximum diameter of the HHs ranged from 5 to 80 mm (median 15 mm), and 15 of the tumors were giant HHs with a diameter of 30 mm or more. Comorbidities included precocious puberty (33.0%), behavioral disorder (49.0%), and mental retardation (50.0%).

RESULTS

A total of 140 SRT procedures were performed. There was no adaptive restriction for the giant or the subtype of HH, regardless of any prior history of surgical treatment or comorbidities. Patients in this case series exhibited delayed precocious puberty (9.0%), pituitary dysfunction (2.0%), and weight gain (7.0%), besides the transient hypothalamic symptoms after SRT. Freedom from GS was achieved in 86.0% of patients, freedom from other types of seizures in 78.9%, and freedom from all seizures in 71.0%. Repeat surgeries were not effective for non-GS. Seizure freedom led to disappearance of behavioral disorders and to intellectual improvement.

CONCLUSIONS

The present SRT procedure is a minimally invasive and highly effective surgical procedure without adaptive limitations. SRT involves only a single surgical procedure appropriate for all forms of epileptogenic HH and should be considered in patients with an early history of GS.
Fiber tracts of the dorsal language stream in the human brain
Authors: Yagmurlu Kaan , Middlebrooks Erik H. , Tanriover Necmettin , Rhoton Albert L.
Published: November 2015

OBJECT

The aim of this study was to examine the arcuate (AF) and superior longitudinal fasciculi (SLF), which together form the dorsal language stream, using fiber dissection and diffusion imaging techniques in the human brain.

METHODS

Twenty-five formalin-fixed brains (50 hemispheres) and 3 adult cadaveric heads, prepared according to the Klingler method, were examined by the fiber dissection technique. The authors’ findings were supported with MR tractography provided by the Human Connectome Project, WU-Minn Consortium. The frequencies of gyral distributions were calculated in segments of the AF and SLF in the cadaveric specimens.

RESULTS

The AF has ventral and dorsal segments, and the SLF has 3 segments: SLF I (dorsal pathway), II (middle pathway), and III (ventral pathway). The AF ventral segment connects the middle (88%; all percentages represent the area of the named structure that is connected to the tract) and posterior (100%) parts of the superior temporal gyri and the middle part (92%) of the middle temporal gyrus to the posterior part of the inferior frontal gyrus (96% in pars opercularis, 40% in pars triangularis) and the ventral premotor cortex (84%) by passing deep to the lower part of the supramarginal gyrus (100%). The AF dorsal segment connects the posterior part of the middle (100%) and inferior temporal gyri (76%) to the posterior part of the inferior frontal gyrus (96% in pars opercularis), ventral premotor cortex (72%), and posterior part of the middle frontal gyrus (56%) by passing deep to the lower part of the angular gyrus (100%).

CONCLUSIONS

This study depicts the distinct subdivision of the AF and SLF, based on cadaveric fiber dissection and diffusion imaging techniques, to clarify the complicated language processing pathways.
Management of arteriovenous malformations in the elderly: a single-center case series and analysis of outcomes
Authors: Pabaney Aqueel H. , Reinard Kevin A. , Kole Max K. , Seyfried Donald M. , Malik Ghaus M.
Published: November 2015

OBJECT

Treatment of brain arteriovenous malformations (bAVMs) in the elderly remains a challenge for cerebrovascular surgeons. In this study the authors reviewed the patient characteristics, treatments, angiographic results, and clinical outcomes in 28 patients over 65 years of age who were treated at Henry Ford Hospital between 1990 and 2014.

METHODS

The bAVM database at the authors’ institution was queried for records of elderly patients with bAVMs, and data regarding patient demographics, presenting symptoms, bAVM angioarchitecture, treatment modalities, angiographic results, clinical outcomes, and treatment complications were tabulated and analyzed.

RESULTS

There were 9 male (32%) and 19 female (68%) patients, with an average age ( ± SD) of 73.0 ± 6.95 years. The most common symptoms on presentation were hemorrhage (36%) and headaches (18%). The bAVMs were equally distributed between the supra- and infratentorial compartments. The most common Spetzler-Martin grade was II, observed in 57% of the patients. Eleven patients (39.3%) underwent resection, 4 patients (14.3%) received standalone radiation therapy, and 13 patients (46%) did not receive treatment or were managed expectantly. Four patients (14.3%) were lost to follow-up. Complete bAVM obliteration was achieved in 87% of the treated patients. None of the patients who received any form of treatment died; the overall mortality rate was 3.6%.

CONCLUSIONS

Surgical management of bAVMs in the elderly can result in complete obliteration and acceptable clinical outcomes.
Reversible coma and Duret hemorrhage after intracranial hypotension from remote lumbar spine surgery: case report
Authors: Bonow Robert H. , Bales James W. , Morton Ryan P. , Levitt Michael R. , Zhang Fangyi
Published: November 2015

Intracranial hypotension is a rare condition caused by spontaneous or iatrogenic CSF leaks that alter normal CSF dynamics. Symptoms range from mild headaches to transtentorial herniation, coma, and death. Duret hemorrhages have been reported to occur in some patients with this condition and are traditionally believed to be associated with a poor neurological outcome. A 73-year-old man with a remote history of spinal fusion presented with syncope and was found to have small subdural hematomas on head CT studies. He was managed nonoperatively and discharged with a Glasgow Coma Scale score of 15, only to return 3 days later with obtundation, fixed downward gaze, anisocoria, and absent cranial nerve reflexes. A CT scan showed Duret hemorrhages and subtle enlargement of the subdural hematomas, though the hematomas remained too small to account for his poor clinical condition. Magnetic resonance imaging of the spine revealed a large lumbar pseudomeningocele in the area of prior fusion. His condition dramatically improved when he was placed in the Trendelenburg position and underwent repair of the pseudomeningocele. He was kept flat for 7 days and was ultimately discharged in good condition. On long-term follow-up, his only identifiable deficit was diplopia due to an internuclear ophthalmoplegia. Intracranial hypotension is a rare condition that can cause profound morbidity, including tonsillar herniation and brainstem hemorrhage. With proper identification and treatment of the CSF leak, patients can make functional recoveries.
Short-term mortality following surgical procedures for the diagnosis of pediatric brain tumors: outcome analysis in 5533 children from SEER, 2004–2011
Authors: Hankinson Todd C. , Dudley Roy W. R. , Torok Michelle R. , Patibandla Mohana Rao , Dorris Kathleen , Poonia Seerat , Wilkinson C. Corbett , Bruny Jennifer L. , Handler Michael H. , Liu Arthur K.
Published: November 2015

OBJECT

Thirty-day mortality is increasingly a reference metric regarding surgical outcomes. Recent data estimate a 30-day mortality rate of 1.4−2.7% after craniotomy for tumors in children. No detailed analysis of short-term mortality following a diagnostic neurosurgical procedure (e.g., resection or tissue biopsy) for tumor in the US pediatric population has been conducted.

METHODS

The Surveillance, Epidemiology and End Results (SEER) data sets identified patients ≤ 21 years who underwent a diagnostic neurosurgical procedure for primary intracranial tumor from 2004 to 2011. One- and two-month mortality was estimated. Standard statistical methods estimated associations between independent variables and mortality.

RESULTS

A total of 5533 patients met criteria for inclusion. Death occurred within the calendar month of surgery in 64 patients (1.16%) and by the conclusion of the calendar month following surgery in 95 patients (1.72%). Within the first calendar month, patients < 1 year of age (n = 318) had a risk of death of 5.66%, while those from 1 to 21 years (n = 5215) had a risk of 0.88% (p < 0.0001). By the end of the calendar month following surgery, patients < 1 year (n = 318) had a risk of death of 7.23%, while those from 1 to 21 years (n = 5215) had a risk of 1.38% (p < 0.0001). Children < 1 year at diagnosis were more likely to harbor a high-grade lesion than older children (OR 1.9, 95% CI 1.5–2.4).

CONCLUSIONS

In the SEER data sets, the risk of death within 30 days of a diagnostic neurosurgical procedure for a primary pediatric brain tumor is between 1.16% and 1.72%, consistent with contemporary data from European populations. The risk of mortality in infants is considerably higher, between 5.66% and 7.23%, and they harbor more aggressive lesions.
Posterior osteosynthesis of a spontaneous bilateral pedicle fracture of the lumbar spine
Authors: Han Sang-Hyun , Hyun Seung-Jae , Jahng Tae-Ahn , Kim Ki-Jeong
Published: November 2015

Spontaneous bilateral pedicle fractures of the lumbar spine are rare, and an optimal surgical treatment has not been suggested. The authors report the case of a 50-year-old woman who presented with low-back pain and right leg radiating pain of 1 year’s duration. Radiological studies revealed a spontaneous bilateral pedicle fracture of L-5. All efforts at conservative treatment failed, and the patient underwent surgery for osteosynthesis of the fractured pedicle using bilateral pedicle screws connected with a bent rod. Her low-back and right leg pain were relieved postoperatively. A CT scan performed 3 months postoperatively revealed the disappearance of the pedicle fracture gap and presence of newly formed bony trabeculation. In rare cases of spontaneous bilateral pedicle fracture of the lumbar spine, osteosynthesis of the fractured pedicle using bilateral pedicle screws and a bent rod is a motion-preserving technique that may be an effective option when conservative management has failed.
Convenient preparation of high molecular weight poly(dimethylsiloxane) using thermally latent NHC-catalysis: a structure-activity correlation
Authors: Naumann Stefan , Klein Johannes , Wang Dongren , Buchmeiser Michael R
Published: November 2015

The polymerization of octamethylcyclotetrasiloxane (D4) is investigated using several five-, six- and seven-membered N-heterocyclic carbenes (NHCs). The catalysts are delivered in situ from thermally susceptible CO2 adducts. It is demonstrated that the polymerization can be triggered from a latent state by mild heating, using the highly nucleophilic 1,3,4,5-tetramethylimidazol-2-ylidene as organocatalyst. This way, high molecular weight PDMS is prepared (up to >400 000 g/mol, 1.6 < ÐM < 2.5) in yields >95%, using low catalyst loadings (0.2–0.1 mol %). Furthermore, the results suggest that a nucleophilic, zwitterionic mechanism is in operation, in preference to purely anionic polymerization.
Birds from the Azores: An updated list with some comments on species distribution
Authors: Barcelos Luís , Rodrigues Pedro , Bried Joël , Mendonça Enésima , Gabriel Rosalina , Borges Paulo
Published: November 2015

An updated checklist of the Birds of the Azores is presented based on information compiled from Rodrigues et al. (2010) and from the websites, Azores Bird Club. (2014), Aves dos Açores (2014), Azores Bird Sightings (2014) and Vittery (2014), since 2010.

The checklist has a total of 414 species, including 38 new species.

Almost half of the species and subspecies that occur in the Azores have a Palearctic origin, the remaining ones being essentialy Nearctic and Holarctic species. São Miguel is the island with the highest number of bird species, followed by Terceira, Corvo and Flores islands.
Common Neurocutaneous Syndromes
Authors: Little Heather , Kamat Deepak , Sivaswamy Lalitha
Published: November 2015

Neurocutaneous syndromes are a diverse group of neurologic disorders with concurrent skin manifestations. Most neurocutaneous syndromes have a genetic basis and are believed to arise from a defect in the differentiation of the primitive ectoderm. In this regard, the skin can be a window into the central nervous system and can aid in the diagnosis of neurologic disease in children. The cutaneous signs may be subtle, which places great importance on the physical examination skills of clinicians providing primary care to children. Early recognition can help with proper diagnosis, formulating a treatment plan, anticipating potential complications, making appropriate referrals, and offering genetic counseling to families.

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Pediatr Ann
. 2015;44(11):496–498,500–504.]