bluuebunny/crossref_metadata_2025 huggingface dataset:
Coupling Geomechanical Effects and Reservoir Dynamics for Modeling Rejuvenation in Unconventional Plays
Authors: Dutta R.. , Pinto R.. , Flores J. C. , Stolyarov S. M. , Yang J..
Published: October 2018

An integrated understanding of geomechanical effects, fracture propagation and reservoir dynamics is critical in the efficient and cost-effective application of rejuvenation technologies for unconventional plays. While various reservoir models depicting the hydraulic fracturing process are available in the industry, many tend to be simplified or do not capture the numerous parameters that affect both the initial and restimulation processes. This study takes a further step towards building a more realistic picture of fracturing in unconventional plays. In particular, a workflow is presented to couple the geomechanical effects and reservoir simulation modeling in unconventional plays. The objective is to make use of the learnings from this modeling in the successful application of rejuvenation technology.

The integrated model is developed using existing horizontal unconventional wells in a US shale play. During the initial phase of hydraulic fracturing, variations in stress occur both during injection and production periods. These stresses affect the growth of the fracture and its consequent fracture geometry. While employing various rejuvenation technologies, the ability to re-stimulate the rock will depend on a combination of factors, two primary ones being stress variation and pore-pressure depletion. These effects are incorporated into the reservoir model. Consequently, the production history-matched reservoir model incorporates pressure-dependent permeability variation as well as capillary pressure to account for varying reservoir dynamics.

Results from this study highlight the importance of changing stress regimes on fracture geometry and its consequent impact on production. We present a methodology to integrate geomechanical effects into a reservoir simulation model. The study also indicates the importance of treatment fluid volumes pumped at various stages during the refracturing operation.

Additional benefit of restimulating a well will vary from one well to another. The benefit is realized in terms of cumulative fluid volumes and reservoir contacted. The modeling techniques presented may help in application of such restimulation operations based on its impact on recoverable reserves. In summary, this study shows that a comprehensive understanding of stress changes coupled with reservoir dynamics will help better plan the application of various rejuvenation technologies.
Sweet and Sour Fracturing : The Impact of Post-Fracture Clean-Up on H2S and the Reservoir
Authors: Al-Manji A.. , Al-Shueili A.. , Orjuela L.. , White D.. , Kurniadi S. D. , Rylance M..
Published: October 2018

The Barik formation is a tight low-permeability conventional gas reservoir in the Sultanate of Oman comprising of a series of interbedded sandstones and shales. To achieve an efficient and economic development of this formation, the wells require the application of massive hydraulic fracturing operations, in order to achieve the required surface area and connectivity for production delivery.

Hydraulic fracturing operations often involve the use of a wide range of chemical components and the industry has understood for some time that chemical reactions take place both during and after fracture treatments have been performed. Post fracture treatment a wide range of differing chemical effects can take place and this may continue for some time during the extensive flowback and clean-up period. Such chemistries can result in a range of differing effects, including unplanned scaling tendencies, corrosional behaviour and can even influence aspects such as hydrate control. Such effects can also have an adverse impact on the well itself, the surface manifolding/valves, gathering system and production facilities and need to be well appreciated in order to remove issues.

During the early Appraisal of the Barik formation, in Block 61 in the Sultanate of Oman, H2S had been observed during the post-frac well-test operations. However, the Barik reservoir within the Khazzan field, was believed to be sweet and not reflect a measurable H2S; a characteristic that had been confirmed by performing pre-frac openhole sampling. As had been determined with fracturing operations elsewhere, it was surmised that the frac operations themselves where the potential source of the H2S. Potential causes for this included thermal decomposition of fluid chemistry as well as inadvertent contamination of original source water used for the feed fluid. It had been observed/measured, that the magnitude of H2S reduced with time and was directly related to fracturing fluid clean-up. After extensive investigation the evidence suggested that the root-cause was a combination of the presence of a hardy Sulphate Reducing Bacteria (SRB) species along with the presence of a thiosuplhate feedstock in the frac fluid.

This paper will present a full, robust and coherent analysis of the presence of H2S, the rigorous steps that were followed to identify the root-causes and the identification of potential sources/causes. The paper will present the preventive measures that have been taken and their impact on the overall temporary levels of H2S that have been seen in the operations since. The paper will go on to recommend that for future operations, particularly start-up areas, as transitory levels of H2S might not be identified, not because H2S is not there but rather that there is typically no apparatus nor sufficiently accurate surveillance in place on everyday operations to precisely identify such material.
A Novel Approach to Predicting Improvements in Perforation Cluster Treatment Efficiency
Authors: Mientka Matthew , Romberg Eric , Scott Ellen
Published: October 2018

In horizontal-well, plug-and-perforate completions, various studies have shown that not all perforation clusters are stimulated equally. To increase perforation cluster treatment efficiency, engineers attempt to move the perforations of each stage to similarly-stressed rock. Most of these efforts have not included predictions quantifying efficiency improvements. This paper outlines a methodology for predicting improvements of perforation cluster treatment efficiency and includes a case study verifying the results of the model using pre-treatment diagnostics.

In four Western Anadarko Basin wells, the operator measured mechanical rock properties using drill bit geomechanics. These properties were used to calculate the changes in minimum horizontal stress along each ~5,000-ft horizontal well. Within each treatment stage, the engineers chose perforation locations to minimize the difference in minimum horizontal stress. Using offset vertical logs and the geosteering interpretations, the engineers built a high-resolution fracture simulation model for each well. The model included the measured mechanical properties along the wellbore path. Comparing results from a geometric perforation model and the stress-balanced perforation model, the engineers predicted increased perforation cluster efficiencies between 10 and 20%.

The four wells were completed using the stress-balanced perforation designs. Like all previous wells in the area, the operator performed step-down rate tests on these wells before each stimulation treatment. The step-down rate test is a common hydraulic fracturing diagnostic to quantify the number of open perforations taking treatment fluid. Compared to the operator's previous geometrically-perforated wells, the wells with the stress-balanced perforation designs showed more open perforations. A higher number of open perforations suggests a greater perforation cluster treatment efficiency. The increase in efficiency measured by the step-down rate tests was consistent with the model predictions.

By understanding how stress-balancing perforation clusters will affect perforation cluster treatment efficiency, operators can optimize stimulations. The industry has not widely adopted stress-balanced perforation designs or other ‘engineered’ completion strategies. The results of ‘engineered’ completion studies have often been inconclusive, likely due to small sample sizes and reliance on production results. By combining affordable measurement of rock properties, modeled perforation cluster efficiency, and an affordable measurement of perforation efficiency, this paper provides a methodology for economically optimizing multi-stage stimulations in horizontal wells.
Early Identification of a Potential Unconsolidated Reservoir and the Prevention of Sand Flowback by Incorporating a Liquid-Consolidation Agent with a Fracturing Treatment in Saudi Arabia
Authors: Hamid Saad , Almulhim Abdulrahman , Alabbad Emad Abbad , Palanivel Maharaja
Published: October 2018

An engineering approach is discussed for identifying a potentially unconsolidated reservoir in an exploratory area and controlling sand flowback by fracturing using a liquid-consolidation additive as the binding agent.

A vertical gas well targeting an exploratory reservoir was completed and hydraulically fractured to help enhance productivity. A petrophysical evaluation was performed with openhole logs, and results showed a potentially unconsolidated pay zone that posed the risk of producing formation sand.

After identifying the issue, precautionary measures were taken to help prevent sand production. An engineered solution to hydraulically fracture the reservoir using a liquid-consolidating additive as a binding agent, opposed to the conventional resin-precoated proppant, was successfully performed.

The fracturing technique enhanced well productivity and allowed sand-free high production rate of hydrocarbons. Orienting the perforations toward the maximum horizontal stress direction helped reduce tortuosity and placement of the fracturing treatment.

This paper presents petrophysical analysis, treatment design, and application, including production analysis to evaluate the effectiveness of the treatment.

Evaluation of the openhole logs and understanding the criteria for potential sand-producing formations can help identify sand flowback in the early stages of well completion to promote the application of solutions that will substantially reduce/eliminate problems associated with sand flowback during the life of the well. This technique helped achieve sand control without using screens, simplifying wellbore equipment while enhancing reservoir production. Early identification of the problem minimized production losses and non-productive time (days) for the operator and potential formation sanding problems.
Influence of Regional Tectonics and Pore-Pressure Depletion on Tight-Gas Recovery in the Sanga Sanga PSC
Authors: Rylance M..
Published: October 2018

The Sanga-Sanga PSC fields are located onshore Mahakam delta, East Kalimantan, Indonesia. Since the 1970s, they have produced over 80% of originally estimated gas in place with the remaining gas locked up in low permeability sands. A prize of at least 0.75 Tcf would be achievable, if these sub milli-Darcy resources could be developed. However, previous attempts at hydraulic fracturing, over three decades, have been spectacularly ineffective and rarely enjoyed any improvement or uplift at all.

During late 2006, a detailed review of the regional stress-state and prior unsuccessful frac operations was performed. This review unearthed significant evidence of a reverse stress-ordering in the deep low permeability sands, resulting in horizontal fractures being created. While this provided some logic behind the widespread failure rate, it did not in itself offer a direct solution. However, there was also sufficient evidence from previous frac history, to indicate that the solution may lie with a pore-pressure reduction. A pilot program, with meticulous candidate selection was planned to investigate this.

Further investigation determined the presence of a strong poro-elastic relationship and it was assessed that when combined with longevity of production (30 years), that the stress-state would be substantially affected. During 2008, a suite of well candidates were carefully selected with a range of reduced pore- pressures, aligned with the poro-elastic understanding, hydraulic frac treatments were performed and the wells flowed and produced for two years to confirm productivity. The subsequent production behaviour, confirmed a very positive response and the treated wells netted substantial gas/condensate sales. Production behaviour confirmed the poro-elastic relationships and a set of absolute guidelines on candidate selection and fracture execution were created. Subsequent operations that have adhered to these strict guidelines have been extremely successful. The ability of the new approach to reverse a 30- year trend of hydraulic fracturing failure will now lead to the development of the remaining resource within the fields. An extensive treatment campaign will now be possible to perform with between 50 - 100 candidates well opportunities likely to be available in the field.

A careful assessment of the regional stress-state indicated a reverse ordering of the principal stresses as being the root cause of the poor hydraulic fracturing behaviour. However, careful consideration of the rock mechanics and a coherent pilot programme demonstrated the ability, under effective depletion conditions, to place economic and successful hydraulic fracturing treatments.
THE PHYSICAL PROPERTIES OF THE CASEIN IN SOLUTION: EFFECT OF ULTRA-HIGH PRESSURE
Authors: Budkevich Roman O. , Eremina Anastasia I. , Evdokimov Ivan A. , Fedortsov Nikita M. , Martak Alexey A. , Budkevich Elena V.
Published: October 2018

The aim of this work was to study the effect of pressure (50; 90; 160; 250; 350 MPa) on a physical property of casein micelle: hydrodynamic radius, tyrosine and tryptophan fluorescence and IR spectra characteristics. According to photon-correlation spectroscopy, the average hydrodynamic radius of the casein micelle was 128 nm, increasing at 50 MPa to 467 nm with the formation of conglomerates. Further increase of pressure led to the formation of two fractions of particles, differing in hydrodynamic radius. At a pressure of 350 MPa, an average radius of 75 % of particles was 121 nm. Comparison of hydrodynamic radius and tyrosine fluorescence revealed a decrease in the intensity of the glow with an increase in the proportion of large particles and an increase in the radiation in the solution with a decrease of the micelles size. The increase of casein fluorescence by tryptophan and its decrease by tyrosine indicate a change in the conformation of protein molecules during pressure treatment. FTIR spectroscopy revealed a change in the intensity of the optical density in the range of amide I, amide II and valence bonds of tyrosine, confirming the absence of new bonds. The obtained physical data indicate a change in the structure of casein micelles with an increase in the proportion (25 %) of large particles after the action of high pressure (350mpa), which should be taken into account in milk processing. The fluorescence of casein during pressure treatment is a poorly investigated physical indicator and can be important for the processing of raw milk.
Seed Distribution and Invertebrate Seed Predation in No‐Till and Minimum‐Till Maize Systems
Authors: Law Jeffrey J. , Gallagher Robert S.
Published: October 2018

Core Ideas

Minimum tillage was not detrimental to the granivorous invertebrate community.

Seed predation was not weed species specific.

Minimum tillage could obscure seeds from invertebrate seed predators.

The use of low‐intensity tillage is becoming more widespread throughout the United States, and the effects of these tillage methods on invertebrate seed predator activity and weed seed removal is unknown. We investigated the effects of a minimum tillage system (min‐till) (i.e., vertical coulter + rotary harrow + high residue cultivation) that disturbs the first 2 to 5 cm of soil on invertebrate seed predators and invertebrate seed predation in maize (Zea mays L.) fields in the northeastern United States. Pitfall trapping was conducted and weed seed removal was assessed with seed cards in min‐till and no‐till plots. The depth of seed burial by min‐till implements was examined. Overall granivorous invertebrate activity‐densities were higher in min‐till plots when compared with no‐till, with three ground beetle species (Bembidion quadrimaculatum oppositum Say, Pterostichus melanarius Illiger, Chlaenius tricolor Dejean) and field crickets (Gryllus spp.), having increased activity densities and only one ground beetle species (Harpalus pensylvanicus DeGeer), having a decreased activity‐density. Surface seed predation in min‐till and no‐till was not significantly different. Seed burial was found to be significantly higher in min‐till vs. no‐till. We conclude that min‐till is a promising weed management option for the future, but seed burial may hinder the ecosystem service of weed seed predation and bears further examination.
Grazing Crop Residues Has Less Impact in the Short‐Term on Soil Properties than Baling in the Central Great Plains
Authors: Rakkar Manbir K. , Blanco‐Canqui Humberto , Rasby Rick J. , Ulmer Kristen , Cox‐O’Neill Jordan , Drewnoski Mary E. , Drijber Rhae A. , Jenkins Karla , MacDonald James C.
Published: October 2018

Core Ideas

Corn residue grazing had little to no impact on soil health indicators.

Residue baling increased wind erosion risks by 22 to 56%.

Baling reduced near‐surface soil water content by 8 to 32%.

Soil type or precipitation amount did not influence residue removal impacts on soil properties.

Residue grazing can be a more sustainable practice than baling

Cattle grazing and baling of corn (Zea mays L.) residues are common practices in integrated crop–livestock systems, but their impacts on soil properties are not well understood on a regional scale. We conducted a 3‐yr study across a precipitation gradient (ranging from 400 to 804 mm) in the central Great Plains to evaluate soil compaction, structural quality, water content, fertility, sorptivity, and microbial biomass in response to corn residue grazing and baling. Six on‐farm sites varying in soil texture, organic matter, crop rotation, and irrigation practices were established with three residue treatments: control, grazing, and baling. Sites were predominantly under conservation tillage management. Residue baling reduced residue cover by 57% and residue grazing by 17% relative to the control. At most sites, residue baling reduced near‐surface soil water content by 8 to 32% and increased wind erodible fraction by 22 to 56% compared with the control but grazing generally had no effect. Residue grazing and baling had small or no negative effects on other measured soil properties regardless of soil type or precipitation amount. When changes in soil properties did occur, they were due to differences in grazing duration or agronomic management. For example, grazing during spring at one of the sites increased soil bulk density by 7% (1.17 vs. 1.26 Mg m−3) relative to the control. This short‐term study indicates that residue grazing, in general, does not impact soil properties, but residue baling at high rates (>50%) could increase wind erosion risks and reduce surface soil water content in this region.
Fertilizer Application Effects on Grain and Storage Root Nutrient Concentration
Authors: Wortmann Charles S. , Dicko Mohammed K. , Maman Nouri , Senkoro Catherine J. , Tarfa Bitrus Dawi
Published: October 2018

Grain nutrient concentrations can be affected by crop management.

Grain nutrient concentrations were often increased for cereal crops by N–P–K application.

Grain N, K, S, Cu, Mn, and B were reduced by Mg–S–Zn–B application for bean, maize, and rice.

Nutrient concentrations were not much affected by nutrient application for other crop nutrients.

Fertilizer application can affect nutrient concentrations of edible plant products. Data from 70 crop‐nutrient response trials conducted in Mali, Niger, Nigeria, and Tanzania were used to evaluate nutrient application effects on nutrient concentrations for grain of five pulse and five cereal crops and for storage roots of cassava (Manihot esculenta L.). Treatments per trial were ≥12, but this study was limited to: no fertilizer applied; macronutrients applied (NPK or PK); and the macronutrient treatment plus Mg, S, Zn, and B applied (MgSZnB). Dried grain or cassava flour samples were analyzed for concentrations of all essential soil nutrients, except for Ni and Cl. Concentrations of N and K were positively correlated with concentrations of most other nutrients. The concentrations were relatively low overall for cowpea (Vigna unguiculata L.) and pigeonpea (Cajanus cajan L.) compared with other pulse crops and for maize (Zea mays L.) compared with other cereal crops. Application of NPK or PK had little effect on nutrient concentrations, except for increased mean cereal grain concentrations for N, Ca, Mg, S, Zn, Cu, and B. Bean (Phaseolus vulgaris L.), maize and rice (Oryza sativa L.) grain concentrations were reduced by MgSZnB for N, K, S, Cu, Mn, and B. There were no or inconsistent effects of MgSZnB on other crop‐nutrient concentrations. Nutrient concentrations are not reduced by NPK for non‐legumes or PK for pulses, but MgSZnB often reduced bean and cereal nutrient concentrations with greater reductions for immobile compared with mobile nutrients.
Establishing an Effective Teaching Program
Authors: Moorberg Colby
Published: October 2018

Starting a new faculty position with a teaching appointment? Wondering how to be a successful teacher? In this month's Early Career Members column, Dr. Moorberg shares advice to help you establish an effective teaching program.
Soil Nitrogen Leaching in Logged Beetle‐Killed Forests and Implications for Riparian Fuel Reduction
Authors: Rhoades Charles C.
Published: October 2018

Recent extensive forest mortality and subsequent salvage logging may threaten the water supply from headwater catchments in western North America. Land managers confronting current insect outbreaks and projected increases in forest disturbance require information about the potential water quality consequences of these changes. This study is a hillslope‐scale evaluation of soil N and C leaching in lodgepole pine forests that have experienced 80% overstory tree mortality. I measured extractable inorganic and ion resin exchangeable‐N forms, in situ net mineralization and nitrification, and leaching in upland and riparian forests with the following treatment combinations: (i) uncut upland with uncut riparian, (ii) harvested upland with uncut riparian buffer, and (iii) harvested upland with harvested riparian. This design permitted comparison of N cycling and leaching in 30‐m‐wide riparian buffers and a riparian fuel break designed to remove canopy fuels and reduce wildfire concerns in areas with extensive bark beetle infestation. Harvesting increased NO3–N, total dissolved N, and dissolved organic C leachate concentrations in upland landscapes but had little effect on net N transformations. Leachate N and C concentrations were 1.5 times higher in riparian buffers downslope of harvested uplands than those in riparian zones downslope of uncut uplands. Riparian forest harvest increased N leaching relative to uncut buffers, although postharvest concentrations remained well below regional water quality standards. Thus, while this study provides evidence that N leaching from dead buffers is low, it also suggests that riparian fuel reduction may complement wildfire mitigation objectives without compromising watershed protection.

Core Ideas

Nitrogen leaching was low in riparian buffers even though most trees were dead.

Harvest of dead riparian forest increased N losses, but concentration remained low.

Novel riparian management may achieve both wildfire mitigation and watershed protection.
Slow and Fast‐Release Boron Sources in Potash Fertilizers: Spatial Variability, Nutrient Dissolution and Plant Uptake
Authors: da Silva Rodrigo C. , Baird Roslyn , Degryse Fien , McLaughlin Michael J.
Published: October 2018

Core Ideas

A dual‐release boron (B) fertilizer can reduce the risks of seedling toxicity and leaching.

Muriate of potash (MOP) was co‐compacted with slow‐ and fast‐release B sources.

MOP+B resulted in a more uniform B spatial distribution compared to traditional bulk‐blends.

Incorporation of colemanite in the formulation slowed the release of B from the MOP+B fertilizers.

This novel B fertilizer may improve the synchrony between nutrient availability and crop demand.

Boron (B) supply to crops is a challenging fertilization practice, due to its high mobility in soil, its narrow window between deficiency and toxicity and the necessity to evenly apply this micronutrient to the soil. We aimed to increase B fertilizer efficacy through the use of slow‐ and fast‐release borate compounds in a macronutrient carrier fertilizer. Borax, ulexite, and colemanite (alone or combined) were compacted with muriate of potash (MOP) to produce B‐enriched fertilizers varying in proportion of water‐soluble B. One such fertilizer was assessed for spatial B distribution compared with a bulk blend equivalent in a soil tray, while others were assessed for nutrient release in a soil column, and canola (Brassica napus L.) growth in a leached and non‐leached pot trial. The compacted MOP+B fertilizer improved B distribution in soil compared to a simulated bulk blend. The release of B was fastest for borax (>93% released within 2.5 pore volumes [PV]) and slowest for colemanite (<20% released after 20 PV). The combination of slow‐ and fast‐release B sources resulted in initial fast‐release of B followed by a constant slower B release. In leached soil, the higher B losses (up to 80% of applied B) resulted in lower canola B uptake with increasing borax and decreasing colemanite in the formulation. In non‐leached soils, there was no difference in B uptake among fertilizer treatments. The use of dual release B sources in MOP+B fertilizer formulations effectively addresses the risk of B loss, and better matches crop B demands during growth.
Knowledge integration challenges and critical success factors within construction traditional procurement system
Authors: Takhtravanchi Mohammad , Pathirage Chaminda
Published: October 2018

The purpose of this study is to explore and identify the challenges and Critical Success Factors (CSFs) of Knowledge Integration (KI) in terms of capturing, sharing and transferring knowledge within construction projects based on the Traditional Procurement System (TPS). On the basis of available studies on KI and TPS within the industry investigated, multiple case studies were developed to reach the aforementioned objective, involving two case studies to reflect the building sector within construction industry. Furthermore, an Interpretive Structural Modelling (ISM) approach was used to summarize and identify the relationships between the identified challenges. ‘Culture of Organization, ‘Contractual Boundaries’ and ‘Knowledge Management System’ (policies and strategies of organization) are identified as the main challenges. Having an ‘open environment’ and ‘clear liability of project members for sharing knowledge at different phases of project’ are two of identified CSFs, which will assist project managers to enhance the KI process within construction projects undertaken through the TPS.
Gastric mucosa structure in patients with different serum pepsinogen levels and ratios
Authors: Tsukanov V. V. , Tonkikh Yu. L. , Vasyutin A. V. , Peretyatko O. V. , Pulikov A. S. , Baron I. I.
Published: October 2018

Purpose of the study. Determine the gastric mucosa Structure in patients with different serum pepsinogen levels and ratios.

Material and methods. 801 people (387 men, 414 women) underwent clinical examination and determination of pepsinogen-1, pepsinogen-2 and serum anti-Helicobacter pylori antibodies using GastroPanel (Biokhit, Finland). 161 patients with different levels of atrophy determined by serological screening method underwent a fibroesophagogastroduodenoscopy (Olimpus-10) with biopsy and subsequent morphological examination of the gastric mucosa performed using a visual analogue scale according to the Sydney Staging System. 107 patients had morphometry of the gastric mucosa with the determination of the number of central, parietal and mucoid cells.

Results. The prevalence of severe atrophic gastritis in the stomach accounted for 10.9%. H. pylori was detected in 90.0% of the subjects. The morphological study showed atrophy in 94.4–95.8% of subjects with atrophic gastritis of the corpus mucosa of the stomach as defined by serological testing.

Conclusions. Atrophy of the stomach mucous membrane as determined by morphological examination was prevalent in patients with severe atrophic gastritis of the corpus mucosa of the stomach, diagnosed using the method for determining serum pepsinogen levels.
Treatment with a minoinvasive method of the major duodenal papilla
Authors: Levchenko N. V. , Khrachkov V. V. , Shavaliev R. R. , Kislitsyn D. P.
Published: October 2018

In this article there are data of comparative analysis of the results of minimally invasive treatment of benign stenosis of the major duodenal papilla through the use of endoscopic retrograde papillosphincterotomy and antegrade laser papillotomy carried out by means of high-energy holmium (YAG:Ho) laser.

Resolution of stenosis of the major duodenal papilla was performed in the patients of the control group (n = 102) through the use of endoscopic papillosphincterotomy before and after laparoscopic cholecystectomy.

Antegrade laser papillotomy (invention patent №2449757 from 09.11.2010) and cholecystectomy were performed in the patients of core group (n = 35) in the presence of evidence.

Antegrade laser papillotomy was successfully performed in all cases. It allows to less traumatic resolve the stenosis of the major duodenal papilla, even in its intradiverticular location and with the combination of choledoholitiasis. It minimizes the possibility of complications such as bleeding, perforation, pancreatitis in comparison with retrograde techniques.
Prevalence and modern aspects of the treatment of patients with Barrett’s esophagus
Authors: Tsukanov V. V. , Vasyutin A. V. , Butorin N. N. , Tonkikh Yu. L. , Peretyatko O. V. , Pulikov A. S.
Published: October 2018

The article analyzes the prevalence and principles in treatment of Barrett’s esophagus. The prevalence of Barrett’s esophagus varies widely from region to region of the world and has ethnic differences. The use of endoscopic methods and the histological examination of the biopsies of esophageal mucosa are of utmost importance in the diagnosis of this pathology. The prevention of esophageal cancer is the main task in managing patients with Barrett’s esophagus. The length of the Barrett’s esophagus segment, the presence and extent of dysplasia is of the greatest importance to select tactics for managing patients. Endoscopic methods are widely used for the eradication of metaplasia sites, among which the radiofrequency ablation is the most effective one. Prolonged treatment with proton pump inhibitors is safe and reduces the risk of transformation of Barrett’s esophagus into adenocarcinoma of the esophagus. There is evidence that small doses of aspirin, nonsteroidal anti-inflammatory drugs, statins and ursodeoxycholic acid have the preventive effect on the development of esophageal cancer. However, the possibilities of using these drugs for this purpose are still limited. Anti-reflux surgery still holds relevance, but at the same time, it has no advantages over the drug therapy for the prevention of esophageal cancer.
Constipation needs to be treated
Authors: Plotnikova E. Yu. , Krasnov K. A.
Published: October 2018

The article presents etiology, pathophysiology and epidemiology of constipation. The main groups of drugs that are used for this pathology are described in the section Treatment of Constipation. Stimulant laxatives are the most commonly demanded by the patients. The article provides the analysis of the use of sodium picosulfate in various clinical studies. Sodium picosulfate is one of the main drugs from the stimulant laxative group.
Therapy for erosive esophagitis induced by mixed reflux in patients with CAD
Authors: Minushkin O. N. , Shuleshova A. G. , Bondarev K. A. , Danilov D. V.
Published: October 2018

The article presents the results of using a combination of PPI (pantoprazole) and UDCA for the treatment of erosive esophagitis induced by mixed reflux in patients with coronary artery disease.

A total of 62 patients with EGDS-proven erosive esophagitis were enrolled in the study. The patients were divided into two groups: the active treatment group (ATG) which included 34 patients with erosive reflux esophagitis and control group (CG), which included 28 patients with erosive reflux esophagitis without CAD. The patients of both groups received IPP (pantoprazole) 80 mg/day and UDCA at a dosage of 15 mg/kg/day for 12 weeks. (84 days).

The study showed that complete epithelialization of esophageal mucosa defects was detected in 100% of ATG patients by Day 84 of therapy, the same was achieved in CG patients by Day 56 of the basic course of therapy.

The treatment of EE induced by mixed reflux with a combination of PPI (pantoprazole) at a dose of 80 mg/day and UDCA at a dosage of 15 mg/kg/day was efficient in patients with GERD and CAD as a basic course of therapy for not less than 84 days. An effective dose of UDCA for maintenance therapy is 5 mg/kg/day in combination with PPI at a daily dose of 40 mg for not less than 2 months.
Desenvolvimento em Saúde nos Municípios Mineiros: análise dos fatores condicionantes
Authors: Magalhães Fernanda Gabriela Gandra Pimenta , Ferreira Marco Aurélio Marques
Published: October 2018

Este estudo avança ao propor uma integração entre variáveis apontadas pela literatura como determinantes para saúde, no sentido de entender quais delas exercem impacto sobre o desenvolvimento em saúde nos municípios, analisado pelo IFDM-Saúde. Entende-se que compreender como as características e condições dos municípios podem influenciar o potencial de desenvolvimento em saúde dos municípios, auxiliará a entender os motivos que fazem com que alguns municípios sejam mais desenvolvidos em termos de saúde do que outros. Nesse sentido, considera-se que a importância deste estudo reside na identificação dos fatores que tendem a impactar nos níveis de desenvolvimento, tendo assim potencial para fornecer aos gestores públicos ferramentas capazes de identificar quais fatores impactam positivamente ou negativamente o desenvolvimento em saúde do município. O universo de análise da pesquisa são os municípios do estado de Minas Gerais. Utilizou-se como metodologia a análise fatorial seguida da regressão logística. Ao fim, conclui-se que são três os fatores condicionantes: “dimensão infra estrutural e educacional”, “dimensão social” e “distribuição de renda e proteção social”. Os resultados aos quais esta pesquisa encaminhou asseveram a importância de que esses fatores múltiplos não sejam desconsiderados ou subvalorizados na análise ou na formulação de políticas municipais de saúde, uma vez que geram impacto nas condições de saúde do município.
A economia da Rússia no século 21: as dinâmicas da ascensão econômica e da relativa estagnação após a crise global de 2008
Authors: Manzi Rafael Henrique Dias
Published: October 2018

O desempenho da economia da Rússia na primeira década após o esfacelamento político da União Soviética foi marcado por instabilidades macroeconômicas e por uma profunda recessão econômica. Esse cenário reverteu-se a partir do início do século 21 quando o país entrou em um novo ciclo de expansão econômica marcada por uma expressiva aceleração das taxas de crescimento do PIB. Contudo, a partir da década de 2010, a economia russa perdeu dinamismo e o processo de convergência de renda com os países desenvolvidos estagnou-se novamente. O principal objetivo do artigo é fazer uma análise do processo deascensão econômica da Rússia e do atual quadro de relativa estagnação a partir da eclosão da crise global de 2008. Os resultados apontam que o quadro de relativa estagnação da economia da Rússia não está ligado somente a fatores conjunturais, como a queda dos preços das commodities energéticas nos mercados internacionais e o acirramento das tensões geopolíticas com o mundo ocidental, mas refletem também, em grande medida, fragilidades domésticas da economia russa.
A Construção da Paz no Cenário Internacional: Do Peacekeeping Tradicional às Críticas ao Peacebuilding Liberal
Authors: Guerra Lucas , Blanco Ramon
Published: October 2018

O presente artigo tem por objetivo fazer uma contextualização geral a respeito das operações de paz das Nações Unidas. Primeiramente, enfatiza-se a possível relação entre o desenvolvimento histórico dessas operações e os distintos contextos internacionais no qual se inserem. Um maior destaque é dado às operações de paz contemporâneas, especialmente as de peacebuilding. São investigados os pressupostos normativos subjacentes ao modelo de atuação dessas, suas características centrais e as principais críticas que recebem em suaconfiguração atual. Com base em uma metodologia essencialmente qualitativa, com ampla revisão bibliográfica acerca do tema, foi possível constatar que o modo de atuação assumido pelas operações de paz é responsivo às tendências e agendas assumidas em um contexto internacional mais amplo. No caso das operações de peacebuilding, verifica-se que assimilam em suas diretrizes os princípios da “paz liberal” dominantes no cenário internacional pós-Guerra Fria, buscando disseminar democracias liberais orientadas para o livre mercado como estratégia ideal para a construção da paz em cenários pós-conflito. Há, porém, uma série de críticas à forma de atuação das operações de paz nesses cenários, desde algumas de caráter procedimental até aquelas estruturais que questionam os próprios pressupostos normativos da paz liberal e sua incidência junto às populações locais.
The Glycogen Synthase Kinase-3 in the Regulation of Ion Channels and Cellular Carriers
Authors: Sopjani Mentor , Millaku Lulzim , Nebija Dashnor , Emini Merita , Rifati-Nixha Arleta , Dërmaku-Sopjani Miribane
Published: October 2018

Glycogen synthase kinase-3 (GSK-3) is a highly evolutionarily conserved and
ubiquitously expressed serine/threonine kinase, an enzyme protein profoundly specific for
glycogen synthase (GS). GSK-3 is involved in various cellular functions and physiological
processes, including cell proliferation, differentiation, motility, and survival as well as glycogen
metabolism, protein synthesis, and apoptosis. There are two isoforms of human GSK-3
(named GSK-3α and GSK-3β) encoded by two distinct genes. Recently, GSK-3β has been
reported to function as a powerful regulator of various transport processes across the cell
membrane. This kinase, GSK-3β, either directly or indirectly, may stimulate or inhibit many
different types of transporter proteins, including ion channel and cellular carriers. More specifically,
GSK-3β-sensitive cellular transport regulation involves various calcium, chloride,
sodium, and potassium ion channels, as well as a number of Na+-coupled cellular carriers including
excitatory amino acid transporters EAAT2, 3 and 4, high-affinity Na+ coupled glucose
carriers SGLT1, creatine transporter 1 CreaT1, and the type II sodium/phosphate cotransporter
NaPi-IIa. The GSK-3β-dependent cellular transport regulations are a part of the
kinase functions in numerous physiological and pathophysiological processes. Clearly, additional
studies are required to examine the role of GSK-3β in many other types of cellular
transporters as well as further elucidating the underlying mechanisms of GSK-3β-mediated
cellular transport regulation.
Recent Advances and Challenges of the Drugs Acting on Monoamine Transporters
Authors: Xue Weiwei , Fu Tingting , Zheng Guoxun , Tu Gao , Zhang Yang , Yang Fengyuan , Tao Lin , Yao Lixia , Zhu Feng
Published: October 2018

Background:

The human Monoamine Transporters (hMATs), primarily including hSERT,
hNET and hDAT, are important targets for the treatment of depression and other behavioral disorders
with more than the availability of 30 approved drugs.

Objective:

This paper is to review the recent progress in the binding mode and inhibitory mechanism of
hMATs inhibitors with the central or allosteric binding sites, for the benefit of future hMATs inhibitor
design and discovery. The Structure-Activity Relationship (SAR) and the selectivity for hit/lead compounds
to hMATs that are evaluated by in vitro and in vivo experiments will be highlighted.

Methods:

PubMed and Web of Science databases were searched for protein-ligand interaction, novel
inhibitors design and synthesis studies related to hMATs.

Results:

Literature data indicate that since the first crystal structure determinations of the homologous
bacterial Leucine Transporter (LeuT) complexed with clomipramine, a sizable database of over 100 experimental
structures or computational models has been accumulated that now defines a substantial degree
of structural variability hMATs-ligands recognition. In the meanwhile, a number of novel hMATs
inhibitors have been discovered by medicinal chemistry with significant help from computational models.

Conclusion:

The reported new compounds act on hMATs as well as the structures of the transporters
complexed with diverse ligands by either experiment or computational modeling have shed light on the
poly-pharmacology, multimodal and allosteric regulation of the drugs to transporters. All of the studies
will greatly promote the Structure-Based Drug Design (SBDD) of structurally novel scaffolds with high
activity and selectivity for hMATs.
Peripheral Immunity, Immunoaging and Neuroinflammation in Parkinson’s Disease
Authors: Kustrimovic Natasa , Marino Franca , Cosentino Marco
Published: October 2018

:

Parkinson’s disease (PD) is the second most common neurodegenerative disorder among elderly population, characterized by the progressive degeneration of dopaminergic neurons in the midbrain. To date, exact cause remains unknown and the mechanism of neurons death uncertain. It is typically considered as a disease of central nervous system (CNS). Nevertheless, numerous evidence has been accumulated in several past years testifying undoubtedly about the principal role of neuroinflammation in progression of PD. Neuroinflammation is mainly associated with presence of activated microglia in brain and elevated levels of cytokine levels in CNS. Nevertheless, active participation of immune system as well has been noted, such as, elevated levels of cytokine levels in blood, the presence of auto antibodies, and the infiltration of T cell in CNS. Moreover, infiltration and reactivation of those T cells could exacerbate neuroinflammation to greater neurotoxic levels. Hence, peripheral inflammation is able to prime microglia into pro-inflammatory phenotype, which can trigger stronger response in CNS further perpetuating the on-going neurodegenerative process.

:

In the present review, the interplay between neuroinflammation and the peripheral immune response in the pathobiology of PD will be discussed. First of all, an overview of regulation of microglial activation and neuroinflammation is summarized and discussed. Afterwards, we try to collectively analyze changes that occurs in peripheral immune system of PD patients, suggesting that these peripheral immune challenges can exacerbate the process of neuroinflammation and hence the symptoms of the disease. In the end, we summarize some of proposed immunotherapies for treatment of PD.
Solid Lipid Nanoparticles and Chitosan-coated Solid Lipid Nanoparticles as Promising Tool for Silybin Delivery: Formulation, Characterization, and In vitro Evaluation
Authors: Piazzini Vieri , Cinci Lorenzo , D'Ambrosio Mario , Luceri Cristina , Bilia Anna Rita , Bergonzi Maria Camilla
Published: October 2018

Background:

Silybin (Sb) is the major flavolignan of the extract of Silybum marianum.
It is used for the treatment of various acute and chronic liver toxicities, inflammation, fibrosis and
oxidative stress. Many studies indicate that Sb is also active against different carcinomas and it has
been very recently proposed to be beneficial in type 2 diabetes patients. However, Sb is a low water
soluble and low permeable compound.

Objective:

In this study, Solid Lipid Nanoparticles (SLNs) were proposed to enhance the solubility
and the intestinal absorption of Sb.

Methods: SLNs were made of stearic acid and Brij 78 and subsequently coated with chitosan.
Formulations were physically and chemically characterized. Stability studies were also assessed. Sb
in vitro release was evaluated in different pH media. In vitro permeability test with artificial
membranes and Caco-2 cells were performed. Cellular uptake and mucoadhesion studies were
conducted.

Results:

Both nanoparticles were found to be stable. In vitro release indicated that SLNs may prevent
burst release and gastric degradation of Sb. Higher extent of Sb permeation was observed for
both nanoparticles in PAMPA and Caco-2 cell monolayer models. The results of the cellular uptake
study suggested the involvement of active endocytic processes. Chitosan significantly improves
mucoadhesion properties of nanoparticles.

Conclusions: Together with the excellent stability, strong mucoadhesive property, and slow release,
chitosan coated SLNs demonstrated promising potential to enhance absorption of hydrophobic Sb after
oral administration.
Design, Synthesis, and Characterization of Novel Linomide Analogues and their Evaluation for Anticancer Activity
Authors: Priolkar Rudrax N.S. , Shingade Sunil , Palkar Mahesh , Desai Shivalingrao M.
Published: October 2018

Background:

According to WHO, in 2017, about 90.5 million people suffered from
cancer and about 8.8 million deaths occurred due to disease. Although the chemotherapeutic
agents have decreased the mortality among the cancer patients but high toxicity and non-specific
targets are still major drawbacks.

:

Many researchers have identified linomide, a 4-hydroxy-2-quinolone derivative, as a lead molecule for
the development of anticancer agents. With this background, we thought of the following objective.

Objective:

The objective of this research work involves the synthesis of a series of N-(2-(4-
hydroxy-2-oxo-1-phenyl-1,2-dihydroquinolin-3-yl)-2-oxoethyl)-N-alkyl substituted benzene
sulfonamides IVa-d (1-3) by replacing the anilide moiety at the third position of linomide with
sulfamoylacyl and also N-methyl by N-phenyl functionality. To perform in silico anticancer activity
by using Molegro Virtual Docker (MVD-2013, 6.0) software and in vitro anticancer activity
by MTT assay.

Methods:

The starting material 4-hydroxy-1-phenylquinolin-2(1H)-one was treated with N-bromosuccinamide
to yield compound II. Condensation of compound II with primary amines resulted in
compounds IIIa-d, which, on coupling with substituted aromatic sulfonyl chlorides yield the title
compounds IVa-d (1-3).

Results:

All the synthesized compounds were satisfactorily characterized by spectral data. The results
of docking revealed that the synthesized compounds exhibited well-conserved hydrogen
bonds with one or more amino acid residues in the active pocket of EGFRK tyrosine kinase domain
(PDB ID: 1m17). The MolDock Score of compound IVd-1 (-115.503) was the highest
amongst those tested. The in vitro anticancer activity results showed that compound IVc-1 (R= -
(CH2) 2-CH3 ; R′= -H) and IV d-1 (R= -CH2-C6H5; R′= -H) were found to be most potent against
K562 cell line with an IC50 of 0.451 μM/ml and 0.455 μM/ml respectively. Compound IVd-1 also
showed better potency against A549 cell line with IC50 value of 0.704 μM/ml.

Conclusion:

The results of in silico and in vitro anticancer activity are in agreement with each other.
Compound IV d-1 was found to be most active of the series.