bluuebunny/crossref_metadata_2025_split huggingface dataset:
Increasing levels of circulating Th17 cells and interleukin-17 in rheumatoid arthritis patients with an inadequate response to anti-TNF-α therapy
Authors: Chen Der-Yuan , Chen Yi-Ming , Chen Hsin-Hua , Hsieh Chia-Wei , Lin Chi-Chen , Lan Joung-Liang 
Published: July 2011

Abstract
Introduction
The objective of this study was to investigate the effects of tumor necrosis factor (TNF)-α inhibitors on circulating T helper-type 17 (Th17) cells and Th17-related cytokines in patients with rheumatoid arthritis (RA).

Methods
The frequencies of circulating Th17 cells and serum levels of Th17-related cytokines were determined using flow cytometry analysis and ELISA, respectively, in 48 RA patients both before (baseline) and six months after anti-TNF-α therapy. Therapeutic response was evaluated using European League Against Rheumatism (EULAR) response criteria.

Results
Significantly higher baseline frequencies of circulating Th17 cells and serum levels of interleukin (IL)-6, IL-17, IL-21, IL-23 and TNF-α were observed in active RA patients than in 12 healthy controls (all P < 0.001). After anti-TNF-α therapy, 36 patients (75%) were EULAR responders (20 good responders and 16 moderate responders) and 12 (25.0%) were non-responders. The mean levels of circulating Th17 cells and IL-17 significantly decreased (1.13% vs. 0.79%; 43.1 pg/ml vs. 27.8 pg/ml; respectively, both P < 0.001) in parallel with clinical remission in responders. Levels of IL-6, IL-21, IL-23 and TNF-α were significantly decreased after anti-TNF-α therapy in responders. In contrast, the mean levels of circulating Th17 cells and IL-17 significantly increased after anti-TNF-α therapy (2.94% vs. 4.23%; 92.1 pg/ml vs. 148.6 pg/ml; respectively, both P < 0.05) in non-responders. Logistic regression analysis identified a high baseline level of IL-17 as a significant predictor of poor therapeutic response.

Conclusions
The beneficial effect of anti-TNF-α therapy might involve a decrease in Th17-related cytokines in responders, whereas rising levels of circulating Th17-cells and IL-17 were observed in patients with an inadequate response to anti-TNF-α therapy.
Accuracy of CT angiography in the assessment of the circle of Willis: comparison of volume-rendered images and digital subtraction angiography
Authors: Han Ari , Yoon Dae Young , Chang Suk Ki , Lim Kyoung Ja , Cho Byung-Moon , Shin Yoon Cheol , Kim Sam Soo , Kim Keon Ha 
Published: July 2011

Background Computed tomography angiography (CTA) is increasingly used for non-invasive imaging of the cerebrovascular diseases. Purpose To evaluate the accuracy of CTA in the assessment of the variation of the segment calibers of the circle of Willis. Material and Methods One hundred and 17 patients with acute SAH (51 men and 66 women, mean age 50.9 years) who underwent CTA using a 16 detector-row CT scanner and DSA were evaluated retrospectively. The CTA and DSA studies were performed within 24 h after the onset of symptoms and within 24 h of each other. A total of 819 arterial segments (A-comA, right and left A1 segment, right and left P-com A, and right and left P1 segment) of the circle of Willis were determined to be aplastic (grade 1), hypoplastic (grade 2), or normal-sized (grade 3) by blinded observers evaluating CTA volume-rendered images. The CTA results were then compared with findings on the corresponding DSA images (reference standard). Results The overall agreement between CTA and DSA was 92.4%. We had 62 (7.6%) cases of disagreement (58 cases of under-estimation and four cases of over-estimation by CTA) between tow modalities. The sensitivity and specificity of CTA in the detection of aplastic and normal-sized segments were more than 90%. In contrast, subgroup analysis of the hypoplastic segments showed a sensitivity of 52.6% and a specificity of 98.2%. Conclusion CTA is highly accurate in the assessment of anatomical variations of the circle of Willis; however, its sensitivity is limited in depicting hypoplastic segments.
Lack of ADAM15 in mice is associated with increased osteoblast function and bone mass
Authors: Marzia Marilena , Guaiquil Victor , Horne William C. , Blobel Carl P. , Baron Roland , Chiusaroli Riccardo 
Published: July 2011

Abstract
The ADAMs (a disintegrin and metalloprotease) contribute to various biological functions including the development of tissues by taking part in cell-cell and cell-matrix interactions. We previously found that ADAM15 is prominently expressed in osteoblasts and to a lesser extent in osteoclasts. The aim of this study was to investigate a possible function of ADAM15 in bone. Adult ADAM15-/- mice displayed an increase in bone volume and thickness with an increase in the number and activity of osteoblasts, whereas osteoclasts were apparently unaffected. We found an increase in proliferation, alkaline phosphatase (ALP) staining and nodule deposition, and mineralization in cultures of ADAM15-/- osteoblasts compared to wild-type osteoblasts. We also observed an increase in β-catenin immunoreactivity in the nucleus of ADAM15-/- osteoblasts compared to wild-type, whereas β-catenin in the membrane/cytoplasm compartment appeared to undergo increased degradation. Furthermore, cyclin D1 and c-Jun, known downstream targets of β-catenin and effectors of cell activation, were found up-regulated in absence of ADAM15. This study indicates that ADAM15 is required for normal skeletal homeostasis and that its absence causes increased nuclear translocation of β-catenin in osteoblasts leading to increased osteoblast proliferation and function, which results in higher trabecular and cortical bone mass.
Utilization of surfactants for consolidation of wooden work of art
Authors: Kubrichtová Daniela , Kučerová Irena 
Published: July 2011

Abstract
The effect of consolidation is proportional to the content of polymer in wood, i.e., to the ability of wood to absorb a polymer solution. One of the ways of increasing the absorption of the polymer solution is its modification by a surfactant. This article evaluates in detail the impact of non-ionic, anionic, and cationic surfactants on penetration of the ethylmethacrylate and methacrylate copolymer solution (Paraloid B72 in toluene) into lime wood by capillary rise. The impact of surfactants is evaluated on the basis of the solution surface tension, the contact angle of a sessile drop, and absorption of the solution by wood. Anionic and non-ionic surfactants based on polyoxyethylene had a positive impact on penetration of Paraloid B72 solution due to their ability to form inverse micelles in toluene. Fluorinated surfactants, polydimethylsiloxane-based surfactants, and cationic surfactants worsen its penetration.
Preparation of chitosan oligomers and characterization: their antifungal activities and decay resistance
Authors: Hussain Ibrar , Singh Tripti , Chittenden Colleen 
Published: July 2011

Abstract
Chitosan, a polymer of D-glucosamine, is known for its antimicrobial activity. However, the physicochemical properties of chitosan depend upon three principal factors, i.e., source of raw material, molecular weight and degree of deacetylation. Here, synthesis and characterization of chitosan oligomers is reported, which were prepared by the nitrous acid deaminative depolymerization of chitosan obtained from Sigma Aldrich and China (industrial grade). Subsequently, their antifungal activities were evaluated against selected basid-iomycetes. The nutrient medium bioassay results show that chitosans and chitosan oligomers affected mycelial growth to different magnitudes. Nevertheless, two of the low-MW chitosan oligomers completely inhibited the growth of all the tested fungi as compared to high-MW chitosan oligomers. Accordingly, antifungal activity increases by decreasing degree of polymerization of chitosan oligomers, which is divergent to literature data. The wood decay trial confirmed the antifungal activity of chitosan oligomers against basid-iomycetes. Chitosan is leachable by water.
Longitudinal Study of Effect of Hotz's Plate and Lip Adhesion on Maxillary Growth in Bilateral Cleft Lip and Palate Patients
Authors: Hak Muhammad Syafrudin , Sasaguri Masaaki , Sulaiman Farida Kamil , Hardono Enny Tyasandarwati , Suzuki Akira , Nakamura Seiji , Ohishi Masamichi 
Published: July 2011

Objective To investigate the effects of infant orthopedic treatment and lip adhesion on maxillary growth of patients with bilateral cleft lip and palate (BCLP). Design Prospective longitudinal study. Setting The present study was conducted at the Cleft Lip and Palate Center, Harapan Kita Children and Maternity Hospital, Indonesia, and the Department of Oral and Maxillofacial Surgery, Kyushu University Hospital, Japan. Subjects The study sample consisted of 53 patients with complete BCLP and 10 noncleft patients with other diseases. Patients with BCLP were divided into three groups: H (-), 11 patients treated without Hotz's plate; H (+), 24 treated with Hotz's plate; and LA-H, 18 treated with lip adhesion and Hotz's plate. Methods Serial dental casts were obtained from each BCLP child at the following four time points: first visit, labioplasty, palatoplasty, and 5 years of age. Each maxillary dental cast was scanned, and the linear and angular dimensions were measured. Results and Conclusion Lip adhesion showed a temporary negative effect. In all patients with BCLP, the surgeries affected the growth of the anterior arch width until the age of 5 years. Collapse of the premaxilla following labioplasty in the H (-) group affected the growth of dental arch length until the age of 5 years. Treatment using Hotz's plate prevented collapse of the premaxilla, and the growth of the arch length was comparable to that observed in the noncleft group.
A New Approach to Aquifer Influx Calculation for Finite Aquifer System
Authors: Omeke James E , Nwachukwu A. , Awo R. O , Obah Boniface , Uche I. N 
Published: July 2011

Abstract
Among the classic models used in the evaluation of aquifer properties, the most used are Van Everdingen & Hurst, (1949), Fetkovich approximate (1971), Carter & Tracy (1960), Allard & Chen (1984), and Leung (1986). Due to the inherent uncertainties in the aquifer characteristics, all the models require historical reservoir performance data to evaluate aquifer property parameters. The fact that the reservoir-aquifer boundary pressure is not constant with time gives rise to computational challenges. Most authors seek to eliminate this disadvantage by bringing up approximate models. Fetkovich assumes a constant boundary pressure while deriving his model and required a superposition to get a proper result. This led to the introduction of some forms of pressure approximation and iterations; any error introduced is constituted by this. Higher computational ability is mostly required especially in the evaluation of the Everdingen & Hurst model due to the application of Duhamel superposition principle. More uncertainty however is also seen in the geometry and areal continuity of the aquifer itself.
In this paper, a fast and simple approach was used to develop a new aquifer influx model for a finite aquifer system that admits a pseudo-steady-state flow regime. The partial differential equation that characterizes the flow of aquifer in the reservoir was considered. It was simplified through some basic assumption and in turn resulted to ordinary differential equation, with an appropriate boundary condition, a solution was gotten that enables a direct calculation of cumulative water influx at a given time without the use of superposition or pressure approximations or iterative means. In other to derive a solution under varying reservoir-aquifer boundary pressure the dependency of the boundary pressure with time was described as an exponential trend, which is mostly the case.
In other to validate the developed model, comparison was made with Carter & Tracy, Fetkovich and Van Everdingen Models. Van Everdingen and Hurst Model was used as the standard for comparison since it represents the exact solution of radial diffusivity equation. Two case examples were considered. The results show a close match between the developed model and the existing models, also from the error analysis made, it was noticed that the predictions of the newly developed model were better than that of the Carter & Tracy.
Application of Genetic Algorithm in Deconvolution of Logs
Authors: Mogbolu Peter O. , Akinola Olayinka , Uguru Chukwuma 
Published: July 2011

Abstract
The wave pattern observed during data acquisition from the subsurface rock is often affected by heterogeneity, formation fluid, tool resolution and other forms of noise. Often however, the aim of the engineer or geologist is to generate the original pattern by deconvolving the wave such as in seismic interpretation. Subsequently, several models have been designed over the years but most of them require the use of cumbrous logical sequences which are difficult to understand and are thus written in computer programs.
This paper aims to solve the problem by the use of a method that involves the backward modelling of such wave patterns using genetic algorithm. This works on the principle of evolution of data such that different individuals converge to a perfect individual, imitating natural evolution. Using this method, a model was created to deconvolve waves. The assumption made was that some waves (including logs) originate from two extreme divergent points before the influence of ‘noise’. The new model was used to recreate the wave pattern and was compared to the input wave.
The model was tested on pseudo-logs wave patterns and the results were estimate to be between 80% and 95% accurate. The significance however, is that such model can be used to recreate lithological patterns which can be used to project forward models by applying certain rock properties.
Best Use of Production Tests – Estimating Well Productivity Parameters in the Absence of Bottomhole Pressure Tests
Authors: Samson Ibukun , Onyekonwu Mike 
Published: July 2011

Abstract
Most operators routinely (usually monthly) carry out production tests on flowing wells as against the bottomhole pressure (BHP) surveys which are not frequently done. This is often the case in wells where economic considerations do not support the costs of acquiring such data. The semi-annual acquisition of BHP data as required by the Department of Petroleum Resources (DPR) is very seldom implemented. This is more so in wells located in marginal fields or wells belonging to smaller operators. In cases where the data is actually acquired, interpretation of the acquired data is frequently not done.
The lack of BHP data has made it difficult for many E&P professionals to estimate well productivity parameters such as productivity index (J), skin (S) and flow efficiency (FE). These parameters are required to predict the performance of production wells and estimate the reserves for such wells. The estimated reserves in turns affect the evaluation of economic viability of such assets.
This paper enumerates practical procedures for estimating and monitoring well productivity parameters from analysis of routine production test data. It also provides procedures for quality checking (therefore accepting or rejecting) results of well productivity parameters obtained from interpretation of BHP tests. The paper goes on to introduce trend analysis as a means of estimating well productivity parameters. A discussion on the conditions under which trends can be extrapolated is also provided. A sample data set is included in the paper as an example to demonstrate some of the proposed procedures and to clarify ambiguities.
Case study: Numerical Simulation on Formation Damage in Low-permeability Gas Reservoir
Authors: Xu Feng , Guo Xiao , Zhang Yong , Wang Mianmian , Zhang Nan , Li Jiudi 
Published: July 2011

Abstract
The study on the formation damage mechanism in low-permeability gas reservoirs is conductive to establish reasonable and effective development policies. The effects that the threshold pressure gradient and stress sensitivity have on productivity during the development. Rock samples of PH group have gone through with threshold pressure gradient measurement and stress sensitivity test. The results show that the average threshold pressure gradient is 0.00011MPa/cm, and stress sensitivity index is 0.04 on average, belonging to low stress sensitivity. In this paper a special method of dealing with seepage law in low permeability gas reservoir is mentioned, including how to process the threshold pressure gradient and converse the experimental data to field application. The formation damages caused by threshold pressure gradient and stress sensitivity are respectively simulated in the numerical simulation software to evaluate their effects on the gas reservoir development. The results of the simulation show that: 1) when the impact of threshold pressure gradient is considered, the stable production period of the gas well is 150 days shorter than that when the impact of threshold pressure gradient is ignored, and the final recovery of stable production is 7.35% lower; 2) when the impact of stress sensitivity is considered, the stable production period of the gas well is 510 days shorter than that when the impact of stress sensitivity is ignored, and the final recovery of stable production is 12.52% lower.
Efficient Methodology for Stimulation Candidate Selection and Well Workover Optimization
Authors: Ugbenyen Benson Oghenovo , Ogbe David O. , Osisanya Samuel O. 
Published: July 2011

Abstract
Nigeria is endowed with huge proven gas reserves estimated to be 184 trillion cubic feet (Tcf). It ranks as the seventh holder of natural gas reserves in the world, and the largest in Africa. Nigeria also flares more natural gas than any other country; it accounts for 12.5% of the world's annual gas flared equivalent to $2.0 billion of annual revenue wasted. There is crucial need, therefore, to reduce gas flaring and its environmental impacts, and to derive maximum economic benefits from gas production.
Well stimulation consists of several methods used for enhancing the natural producing ability of the reservoir when production rate declines. The purpose of the study is to present a methodology and models for the selection, design and optimization of well stimulation. Production decline curve analysis is combined with economic discounting concepts to develop a model that can be used for optimizing stimulation decisions. The model is presented in the form of a non-linear programming problem subject to the constraints imposed by the production facilities, reservoir productivity and the stimulation budget approved by management. Production data from four stimulation candidate wells, offshore Niger Delta was used to validate the model developed by setting up a maximization problem. Solution to the problem was obtained using non-linear optimization software. The results show that the optimization model can be combined with stimulation treatment modules, developed from industry wide models, to quantify stimulation benefits. Candidate wells were then ranked based on stimulation cost, payout time and stimulation benefit. Proposed methodology and models can be used for stimulation candidate selection, ranking workover programs in a field and in optimizing stimulation decisions.
Modeling Petrophysical Properties Input for Probabilistic Reserves Estimation
Authors: Ehigie S. O. 
Published: July 2011

Abstract
While the popularity of the numerical simulation approach (such as the Monte Carlo) for probabilistic reserves estimation has never been higher among geoscientists and reservoir engineers, comparatively little attention has been paid to the techniques needed to correctly model the required petrophysical input parameters.
Petrophysical well analyses typically end in the presentation of average reservoir property values for porosity, water saturation and net-to-gross but these lone averages, while adequate for deterministic reserves estimates, obviously fail to account for the inherent reservoir petrophysical properties uncertainty within a probabilistic reserves estimate. Of more importance for probabilistic reserves estimation is a statistical model comprising Probability Distribution Functions (or PDFs) of the aerial uncertainty in reservoir properties resulting from a larger reservoir being sampled by a relatively small discrete well population.
Monte Carlo simulations are typically used to estimate probabilistic reserves but the accuracy of these are strongly correlated to the quality of the input probability distributions. Many errors in the outputs of reserves models could be traced back to assigning incorrect values to the descriptive parameters of a distribution, and indeed the selection of an appropriate distribution. Therefore, if probability distributions are to be used to represent statistical assumptions of petrophysical properties in reserves estimates, then the way petrophysical averages data is analysed and transformed into PDFs becomes of crucial importance.
Hence, the purpose of this paper is to present practical ideas for achieving the definition of probability distributions that best represent the petrophysical property input into probabilistic reserves estimates.
The focus on petrophysical properties in this paper is not arbitrary or accidental but, instead, reflects the centrality of petrophysical input as a driver of accuracy in reserves estimates.
Optimization of Strategies for Natural Gas Utilization: Niger Delta Case Study
Authors: Ogbe Emmanuel , Ogbe David O. , Iledare Omowumi 
Published: July 2011

Abstract
Nigeria is endowed with huge proven gas reserves estimated to be 184 trillion cubic feet (Tcf). It ranks as the seventh holder of natural gas reserves in the world, and the largest in Africa. Nigeria also flares more natural gas than any other country; it accounts for 12.5% of the world's annual gas flared equivalent to $2.0 billion of annual revenue wasted. There is crucial need, therefore, to reduce gas flaring and its environmental impacts, and to derive maximum economic benefits from gas production.
The purpose of this paper is to identify options for natural gas utilization and to develop a model for optimizing the natural gas utilization strategies using the Niger Delta as a case study. A Linear Programming model is proposed consisting of an objective function that is based on maximizing profit derived from the various utilization projects in the Niger Delta subject to several constraints. The optimal utilization/decision is determined from the solution of the optimization model. Results obtained indicate that the optimal utilization for maximum profit include both current and planned projects such as the Liquefied Natural gas project at Bonny, supply of gas for domestic use and power generation, transport to West African countries, transport of natural gas to Algeria through the TransSaharan Gas Pipeline (TSGP), and sales of EOR products to market. Upcoming project such as the Olokola LNG was only profitable as the gas price increases. Sensitivity analysis is carried out to evaluate impact of changes in the input parameters on the objective function. Paper also discusses the impact of gas pricing on the implementation of the Nigerian gas master plan (NGMP).
The model can be used to select which set of projects would provide maximum profits (net income) from several competing natural gas projects.