bluuebunny/crossref_metadata_2025 huggingface dataset:
Application in Drilling Tool Combination Aided Design Based on Data Intelligence
Authors: Zhu Qi
Published: March 2019

Drilling, as a direct and effective method of opening oil and gas layers, has been widely used. A reasonable combination of drilling tools plays a key role in increasing the rate of mechanical drilling, reducing drilling costs, and reducing downhole accidents. Conventional drilling relies on years of experience of on-site workers and reference to the operation of drilling wells, making use of drilling tools and lacking scientific basis.

However, the reservoir situation is erratic, the unknown factors are very numerous, unpredictable, and the difficulty of drilling is increased. Drilling into unknown reservoirs, especially high-temperature and high-temperature risk wells, poses a huge threat to the lives of workers on site. Conventional drilling of known reservoirs will also encounter unknown problems such as drilling distance growth, stuck drilling, drilling tools falling, increased inclination, and deviation from the intended target position, which seriously reduces drilling efficiency, increases operating time, risk and drilling difficulty affected by the reasonable use of the drilling tool combination.

With the development and application of computational intelligence, through the accumulation of massive geological property data, reservoir structure data, drilling tool parameters, construction data, drilling fluid parameters and other drilling data, intelligent drilling is used to predict unknown drilling information which can reduce the risk of drilling and improve drilling efficiency.

In this paper, the work mode of "data running first, operation post" is used to further strengthen the application of drilling tools combination to improve the rate of mechanical drilling and reduce downhole problems.
Efficient CO2 Multistage Acid Stimulation in Deep Hot-Gas Reservoirs
Authors: Gromakovskii Dmitrii , Palanivel Maharaja , Lopez Alfredo , Mikaelyan Vladimir
Published: March 2019

Acidizing/acid fracturing is an established method of production stimulation in carbonate reservoirs. Over time, reservoirs become depleted, gas production declines, and flowback initiation can require additional time and costs. Energizing/foaming the stimulation fluid was determined to efficiently improve stimulation results and enhance post-treatment well cleanup. The gases most commonly used to energize the treatment fluids include nitrogen (N2) and carbon dioxide (CO2). This paper presents and discusses the results of an effectiveness study of foamed acidizing treatments performed using multistage completions; successful production outcomes were achieved in depleted reservoirs.

The Design-Execution-Evaluation (DEE) cycle begins with a Multistage Fracturing (MSF) well evaluation to determine whether the well is a candidate for foamed treatment. This evaluation includes studies of the reservoir data (reservoir pressure, lithology, and permeability), completion data [including fracture ports and openhole (OH) packers placement versus hole size, reservoir net pay, and lithology], and offset wells stimulation results. Foamed MSF treatments are designed to help enhance post-stimulation performance regarding cost, operational efficiency, and completion limitations. Post-job evaluation includes highlighting the treatment as well as production analysis using a numerical simulator. The post-job evaluation also serves as an input to the design of upcoming treatments.

Foamed multistage acidizing using CO2 foam proved to be successful in terms of post-treatment kickoff, cleanup, and production compared to conventionally treated wells. This success can be attributed to the following effects: Faster post-fracture cleanup as a result of the decreased liquid volume pumped into the reservoirHigher productivity resulting from acid placement benefits enabled by introducing CO2 foam (diversion, retardation)Well delivery time reduction because the post-treatment N2 lift was eliminated as a result of CO2 energy stored in the wellbore and the reservoir

This paper presents the study of CO2 MSF treatments compared to conventionally treated MSF wells. The study results can be used to further optimize treatment designs and improve field execution of upcoming MSF operations as well as help reduce overall well delivery time.
Optimizing Surveillance: A Practice for a Successful Chemical EOR Oilfield Application
Authors: Angulo Yznaga Reinaldo Jose , Quintero Luis Fernando , Arevalo Francisco J , Negm Ehab
Published: March 2019

This paper discusses an optimum approach to design and execution of a robust chemical enhanced oil recovery (EOR) surveillance program considering the physics and uncertainties involved during the implementation of a chemical EOR (CEOR) application at reservoir scale. The surveillance includes techniques, measuring points, and frequency of data acquisition.

Based on field experience, a robust surveillance plan plays a key role in ensuring high performance of a CEOR application during implementation and execution at reservoir conditions. A proper surveillance program should focus on acquiring information associated with the main uncertainties related to fluid-fluid and rock-fluid interactions, the impact of reservoir heterogeneities at reservoir scale, fluid dynamics, and the composition and stability of the chemical formulation. The acquired information should be given to the CEOR modeling team to follow up, interpret, and adjust the CEOR process and reservoir model. Also, the information should be given to the reservoir operation team to tune up the CEOR injection and production process to help optimize performance.

Typically, specialized literature focuses on describing CEOR formulation design and evaluation; laboratory requirements, experimental settings, and analysis results; field application design and implementation; and overall results of field applications. This work emphasizes CEOR process surveillance, its importance, and impact with respect to oilfield scale applications.

There are multiple uncertainties regarding the physical parameters and phenomena that control the performance of the CEOR at reservoir scale (e.g., are uncertainties associated with fluid saturation and properties, rock-fluid interactions, reservoir heterogeneities, and alkali-surfactant-polymer (ASP) formulation behavior at reservoir conditions). A proper surveillance design and implementation help mitigate the impact of the mentioned uncertainties.

Therefore, surveillance is paramount for the success of a CEOR application. The design and execution of a robust surveillance program should consider the main uncertainties associated with the CEOR formulation operating window, fluid-fluid and rock-fluid interactions, reservoir heterogeneities, reservoir conditions, injection-production environment, and various time scales for the timely use of the acquired information and the interpretation feedback to the CEOR modeling and operation teams.

This work discusses the physics and uncertainties considered during the design and execution of an optimized surveillance program. A systematic approach is provided considering fluid-fluid and rock-fluid interactions, reservoir heterogeneities, CEOR formulation operating window, injection – production environment, and time scales to feedback the acquired and interpreted information during the surveillance program execution.
Improving the Permeability Derivation from NMR Data for Reservoir Rocks with Complicated Pore Connectivity
Authors: Kwak Hyung , Gao Jun , Harbi Ahmad
Published: March 2019

The formation permeability is one of the most important Petrophysical information acquired by low field Nuclear Magnetic Resonance (NMR) data. The absolute permeability of reservoir rocks can be accurately calculated by porosity measured by NMR if permeability is well correlated with porosity [1, 2]. This is true for the rocks with all pores are well connected, such as conventional sandstone reservoir. The correlation between permeability and porosity, however, does not always established well for carbonate reservoir rocks, which are known to have heterogeneous pore-to-pore connectivity. Thus, without accurate pore connectivity information, the permeability derived from NMR data for rocks with poor connection among pores is not quite accurate.

The current study proposes a new method to measure an accurate pore-to-pore connectivity from the total volume of a fluid displacement through miscible single phase fluid mixing process. The pore connectivity factor is calculated from the fluid connectivity through different pore systems which can be derived by the volume comparison of NMR invisible D2O replacement with NMR visible H2O in each pore systems. Once the pore connectivity is measured, it is applied to the modified permeability model, such as modified free-fluid model (Timur-Coates model) [3], to calculate accurate permeability. Another benefit of the proposed method is the flexibility of D2O injection condition.

Carbonate reservoir rocks with various degrees of connectivity have been studied in the current study. For the verification purpose, the permeabilities calculated by the proposed method have been compared to those measured by other conventional laboratory techniques.

The proposed method can also be applied to NMR logging technique for accurate NMR driven permeability derivation which currently accepted as references for reservoirs with complicated connectivity, such as carbonates.
Time to Return to the Low Pumping Rates in the Fracture Stimulation of Unconventional Reservoirs
Authors: Sierra Leopoldo
Published: March 2019

To maximize hydrocarbon fluid recovery and economics in a challenging environment of ultralow permeability, an aggressive stimulation strategy is typically proposed. It was designed to reduce the completion or stimulation cost and time by placing multiple perforation clusters (typically three or more clusters per stage) and performing fracture stimulation by pumping the fluid/proppant system at very high rates to generate the necessary differential pressure and multiple fractures per stage.

Because the stimulation pump rate in unconventional reservoirs is typically a function of the number of perforation clusters, number of perforations per cluster, the entry hole diameter of the perforations, and a fixed required minimum rate per perforation, the resulting typical pumping rates to perform fracture stimulations to generate more than one fracture per stage is in the range of 60 to 100 bbl/min or higher. However, historically, the fracture stimulation of multiple perforation clusters performed at high pumping rates often resulted in almost 80% completion efficiency as documented by Wheaton et al. (2016). Therefore, during each stage, single or multiple perforation clusters might not be fractured or marginally stimulated, and thus do not contribute to well production.

To improve the typically observed completion efficiencies in recent years, continuing with the strategy of high treatment rates, self-soluble solid particle systems have been introduced in unconventional reservoir stimulations as an effective diversion system. The same system has been also used during refracturing operations or to increase the number of clusters per stage. This technology has been effectively deployed in the field and has provided value.

Discarding fluid and proppant logistic issues, the high treatment rate requirement for unconventional reservoir fracture stimulation demands the availability on location of high-pressure pumping equipment with very high horse power, which is available in North American operations, but not generally in most international operations. This limitation was addressed as much as possible using the available equipment or by limiting the completion strategy.

To help improve low completion efficiency in unconventional reservoirs, fracture stimulation, and the generation of at least one fracture per perforation cluster, particularly in locations where high-pressure fracturing equipment availability is limited, this paper suggests that the industry return to the conventional low pumping rate fracture stimulation treatments combined with the use of the self-degrading solid diversion systems (SDSDS) to maximize the generation of at least one fracture per perforation cluster.
Production Data Analysis of Shale Gas Wells with Abrupt Gas Rate or Pressure Changes
Authors: Pang Wei , Du Juan , Zhang Tongyi
Published: March 2019

Production data analysis (PDA) by using rate normalized pressure (RNP) and rate normalized pressure derivative (RNP’) is useful for transient rate and pressure analysis of shale gas wells with constant or smooth changing gas rate and pressure. However, some reasons may cause abrupt changes, fluctuation, or even loss of production data. The existing PDA methods can not well address this kind of issue.

The paper analyzes the reasons that cause big changes of shale gas production rate and pressure. The reasons include well-interference, well shut-ins, and converting production from casing to tubing. Typical shale gas well cases in China are described.

Three methods are proposed to address the non-smooth production data issue. For shale gas wells with severe well-interference from neighbouring fracturing wells or production wells, the segmented production data before well-interference is suggested as well-interference is like an imposed negative or positive force from outside, and this force disturbs the normal production performance only rely on the well's own energy. For wells with frequent shut-ins, a virtual equivalent time method is referenced. The process for this method firstly calculates the formation pressure distributions and the average formation pressures within the SRV area; sencondly, calculate the virtual equivalent time by use of the average formation pressure; thirdly, divided the whole production data into several interconnected segments by rearrange the vitual euivalent time into the actual time axis, and finally do the analysis by using the log-log plot of pressure and pressure derivate vs material balance time. For shale gas wells with converting production from casing to tubing, as there are abrupt rate and pressure changes at the converting point, the material balance time may be no more monotonically increasing with production time. We proposed the average material balance time method to solve this problem. For this method, we use average material balance time instead of the material balance time in the log-log plot of pressure and pressure derivative.

Results shows that severe well-interference cause big disturblance and only data before well-interference is suggested for PDA. Both the PDA with average material balance time and PDA with virtual equivalent time can get much better match of production history and log-log plot of pressure and pressure derivative then the exsiting PDA method.
Reservoir Depletion-Induced Proppant Embedment and Dynamic Fracture Closure
Authors: Huang Jian , Safari Reza , Perez Oswaldo , Fragachan Francisco E.
Published: March 2019

An optimized stimulation design not only achieves high productivity during early times, but also necessitates maintaining conductive flow paths during the life of a well. Because of proppant settling and bridging, proppants are not uniformly distributed within developed fracture networks. Moreover, no fractures retain original conductivity during long term depletion, due to proppant embedment and crushing. This paper introduces a model that analytically predicts the proppant deformation and fracture closure behavior, and forecasts production performance.

This model is based on contact mechanics to simulate the mechanical interaction between the proppant pack and formation rock. The fracture aperture can be calculated and updated by taking into account the proppant concentration, non-uniform proppant distribution and in-situ stress conditions. The proppant pack permeability is analytically modelled according to its mechanical properties (size and density) and effective normal stress acting on the fracture surface. In this way, the fracture conductive variation caused by reservoir depletion can be quantified and imported into a reservoir model to forecast production.

This paper presents a new analytical model to describe dynamic fracture closure and its impact on production performance, which varies significantly with the proppant mechanical properties, proppant concentration, proppant distribution, stress condition and formation types. Under different conditions, conductivity evolution of propped fractures can be obtained from the presented model and matched well with multiple experimental tests. Sensitivity of proppant properties, reservoir attributes, and operational parameters are discussed in this study. Production results from these sensitivity analyses can be used to compare and contrast different design scenarios.

This model enables an efficient and reliable prediction of the fracture dynamic closure behavior and identification of controlling parameters to mitigate premature fracture closure. This model honors heterogeneous proppant distribution and related fracture closure, and hence captures more realistic reservoir performance. By integrating stress-dependent fracture conductivity and production analysis in this model, an operational guideline can be provided to maximize the productivity of fractured formations.
A Novel Approach for Formulating CO2 Foam Based Fracturing Fluid by Synthesized Grafting Copolymerization to Enhance its Stability for HPHT Shale Reservoirs
Authors: Chaudhary Sahil , Singh Sandeep , Singh Vikas Kumar
Published: March 2019

Conventional Sources of energy are depleting at an alarming rate which give us unconventional resources as an only option for energy source. Unconventional sources of energy like Shale gas, Tight gas, Coal bed methane are difficult to exploit as compared to the conventional sources of energy. Hydraulic Fracturing is the well stimulation technique used for exploitation and production of these unconventional resources. Foam fracturing is the the most opted stimulation technique for low permeability shallow wells because of its reduced damage potential to reactive and sensitive formations. This research paper discusses about the evaluation of attempt made to develop an eco-friendly CO2 foam based fracturing fluid which can be used at HPHT conditions for shale reservoirs by Grafting Copolymerization. The graft copolymer was developed by free radical polymerization of Gum Acacia (GA) and Lactic acid (LA) by using Potassium Persulphate (KPS) as an initiator and its characterization was done by FESEM and FTIR analysis. Then, the grafted copolymer (GA-g-LA) was processed with CO2 foam based fracturing fluid as an additive. Lecithin is used to emulsify brine and liquid CO2. The effect of graft copolymer was on rheology and stability of the formulated foam based fracturing fluid is evaluated as a function of surfactant concentration. The results are compared with the conventional foam based fracturing fluids. The results showed that grafted copolymer has increased the stability of the formulated fracturing fluid at high temperatures. Use of grafted copolymer results in higher viscosity and proppant carrying capacity which is beneficial for HPHT fracturing conditions. The results of the core flood studies was evaluated on a shale sample to determine its return permeabilty and it was comparable to non-foam based fracturing fluid.
Clean-Up Efficiency of Multiple Fractured Horizontal Wells Enhanced by Reactive Chemicals in Tight Gas Homogeneous & Naturally Fractured Reservoirs
Authors: Vijayvargia Utkarsh , Jamiolahmady Mahmoud , R Nakhli Ayman , Yi Ng Khai
Published: March 2019

Hydraulic fracturing stimulation is considered a successful development technique in tight gas reservoirs. However, these expensive operations sometime underperform due to ineffective fracture fluid (FF) clean-up. This paper concentrates on FF clean-up efficiency for a Multiple Fractured Horizontal Well (MFHW) completed in both homogeneous and naturally fractured (NF) tight gas reservoirs. The emphasis is on NF reservoirs that make up a large percentage of tight gas assets, as their clean-up efficiency has received little attention.

In this study, two numerical simulation models, i.e. a single-porosity single-permeability and a dual porosity-dual permeability model representing a homogeneous and a NF tight gas reservoir respectively, were used. Simulations were conducted on a MFHW with seven hydraulic fractures (HF). The process comprised of injection of FF, then a soaking time (ST) followed by production. The impact of various parameters which includes ST, FF viscosity, pressure drawdown and parameters pertinent to relative permeability and capillary pressure in matrix, hydraulic and natural fractures, were evaluated.

In addition, based on a newly proposed treatment process that generates in-situ pressure and thermal energy that breaks gel viscosity, the effect of resultant viscosity reduction and local pressure increase, for improving the clean-up efficiency was also assessed. In these simulations, and due to uncertainty in its value, NF permeability was varied over a wide range. For conclusive purposes, Gas Production Loss i.e. GPL (%) defined as the difference in total gas production between the completely clean and un-clean cases as a percentage of the clean case, after a specific production period was used. This paper prioritizes the impact of pertinent parameters and highlights the influence of thermochemicals on the clean-up efficiency thereby justifying its commercial practicality. For instance, it is shown that the presence of NFs results initially in higher GPL but then GPL reduces significantly. Reducing the FF viscosity improves clean-up significantly especially for the NF models as NFs are the main contributor to the gas and FF flow from the reservoir to surface via hydraulic fractures. The sometimes non- monotonic trend of GPL variations, depends on the specific combination of NFs’ permeability and FF viscosity which results in the certain fluid invasion profile and mobility in the system.

The paper emphasis is on the impact of thermochemicals and natural fractures on the cleanup up efficiency of hydraulic fracturing stimulations that should be optimized to reduce cost, thereby increasing the profit from these projects.
Modelling Hydraulic Fractures in a Full-Field Dynamic Model Using DPDP Simulation Techniques - An Unconventional Approach Applied in a Tight Carbonate Oil Reservoir, Kuwait, Middle-East
Authors: K. Tiwari Brajesh , Al-Sayegh Saleh , Al-Muraikhi Haifa , Kumar Pranay , Cueille Pierre-Victor , Lislaud Frederic
Published: March 2019

This paper highlights an unconventional approach of using DPDP (Dual Porosity Dual permeability) simulation technique for modelling hydraulic fractures in a full field simulation model during the forecast analysis performed on a tight carbonate reservoir in Kuwait. This was a part of integrated study in which ‘multi-stage hydraulic fracturing’ was recommended as the most optimum stimulation technique in order to enhance the productivity of all the proposed horizontal producers. Importance of DPDP model increases multi-fold when contrast between fracture and matrix permeability is in the order of 10 times or more. In the studied case, as average matrix permeability of the reservoir is in the range of 2-3 mD, this contrast is magnified to the order of 1000-10000 times (considering fracture permeability is in Darcies) which further complements the use of DPDP model.

Three different approaches were tried to model the impact of multi-stage hydraulic fracturing in the full field simulation model; 1) ‘Enhance Well PI’ for all the stimulated wells, 2) ‘Enhance Matrix Permeability’ in the vicinity of all the stimulated wells, hereby referred as SPSP (Single Porosity Single Permeability) approach, and 3) build ‘DPDP Model’ by using upscaled fracture porosity and fracture permeability without changing the matrix properties. First two approaches are very common in the industry but most of the times are not able to capture the real impact of hydraulic fracturing on flow behaviour (bi-linear flow), whereas DPDP model is designed to capture the flow through dual medium. In both SPSP and DPDP approaches permeability anisotropy (increased permeability in the direction perpendicular to horizontal section of the well) in the fractured zone was very well captured and was needed to honour the hydraulic fractures direction. Fracture permeability was calculated using the Poiseuille's law; few sensitivity cases were run to address the associated uncertainty.

Field cumulative oil production and recovery factor were analysed for ‘Enhanced Well PI’ case, SPSP cases and DPDP cases. Field oil cumulative production in DPDP cases is 6% more than SPSP cases and around 10% more than ‘Enhanced Well PI’ case. The hypothesis for the higher recovery in DPDP case with respect to other two cases is that bi-linear flow (fractures are getting filled with the matrix fluid and then feeding to well) is better represented in the DPDP model. Impact in this case is more significant due to the big contrast between matrix and fracture permeability.

Low capacity with high conductivity signature of hydraulic fracture is difficult to model in the SPSP or just by enhancing the well PI. Study clearly demonstrated the benefits of DPDP model for modelling hydraulic fractures over the conventional methods.
Myasthenic crisis treated in a neurological intensive care unit: clinical features, mortality, outcomes, and predictors of survival
Authors: Liu Fan , Wang Qiong , Chen Xueping
Published: March 2019

Background

Myasthenic crisis (MC) often requires admission to an intensive care unit (ICU).

Methods

We retrospectively investigated 115 consecutive patients with first MC admitted to the neurological ICU. Patients’ demographic, clinical and other characteristics were examined, as well as therapeutic interventions; mortality and functional outcome.

Results

MC patients admitted to neurological ICU had a mortality rate of 24.34%. PCO2 level before intubation and score on Myasthenia Gravis–Activities of Daily Living (MG-ADL) scale at MC onset correlated with duration of ventilation and length of ICU stay. Compared with patients with good functional outcome, patients with intermediate or poor functional outcome were older at first MC onset, had lower pH and PO2, and had higher PCO2 before intubation. Multivariate logistic analysis identified pre-intubation PCO2 level as an independent predictor of survival. Cox regression showed that age at first MC onset requiring ICU management was the factor which significantly influenced the mortality. Conclusions: Our results suggest that PCO2 before intubation and MG-ADL score at MC onset may be useful indicators of more severe disease likely to require extensive respiratory support and ICU management. Higher pre-intubation PCO2 indicates chronic respiratory acidosis that can increase risk of severe disability and death, especially in patients with older age at first MC onset.
Effects of intravenous infusion of lidocaine and dexmedetomidine on inhibiting cough during the tracheal extubation period after thyroid surgery
Authors: Hu Shenghong , Li Yuanhai , Wang Shengbin , Xu Siqi , Ju Xia , Ma Li
Published: March 2019

Background：Intravenous lidocaine and dexmedetomidine treatments have been proposed as methods for inhibiting cough. We compared the efficacy of intravenous lidocaine and dexmedetomidine treatments on inhibiting cough during the tracheal extubation period after thyroid surgery. Methods：One hundred eighty patients undergoing thyroid surgeries were randomly allocated to the LIDO group (received lidocaine 1.5 mg/kg loading, 1.5 mg/kg/h infusion), the DEX group (received dexmedetomidine 0.5 µg/kg loading, 0.4 µg/kg/h infusion) and the CON group (received saline), with 60 cases in each group. The primary outcomes of cough were recorded. Secondary outcomes included hemodynamic variables, awareness time, volume of drainage, the postoperative visual analogue scale and adverse effects were recorded. Results: The incidence of cough were significantly lower in the LIDO group (28.3%) and the DEX group (31.7%) than that in the CON group (66.7%) (P=0.000). Additionally, both moderate and severe cough were significantly lower in the LIDO group (13.3%) and the DEX group (13.4%) than these in the CON group (43.4%) (P<0.05). Compared with the two treatment groups, both mean arterial blood pressure and heart rate were significantly increased in the CON group during tracheal extubation (P<0.05). Compared with the CON group, the volume of drainage was significantly reduced in the two treatment groups within 48 hours after surgery (P<0.05). compared with the CON group, the postoperative visual analogue scale was significantly lower in groups LIDO and DEX after surgery(P<0.05). Compared with the LIDO group and the CON group, the time to awareness was longer in the DEX group (P<0.05). In the DEX group, bradycardia was noted in 35 patients, while no bradycardia was noted in LIDO group and CON group. Conclusion: Compared with intravenous infusions of normal saline, both lidocaine and dexmedetomidine had equal effectiveness in attenuating cough and hemodynamic changes during the tracheal extubation period after thyroid surgery, and both of these treatments were able to reduce the volume of postoperative bleeding and provide better analgesic effect after surgery. But intravenous infusions of dexmedetomidine resulted in bradycardia and delayed time to awareness when compared with lidocaine and normal saline.
Prenatal diagnosis of intraventricular hemorrhage
Authors: O.I. Guseva , A.N. Baratova , N.M. Suslina
Published: March 2019

The case of prenatal ultrasound diagnosis of intraventricular hemorrhage of the third degree in the fetus
at 35 weeks of gestation is presented. The child died after birth. The article discusses prenatal diagnosis and
prognosis for children in this pathology.
Prenatal ultrasound differential diagnosis of liver tumors
Authors: M.V. Medvedev
Published: March 2019

Main prenatal ultrasound differential patterns of congenital liver tumors are presented.
Multi-Criteria Decision Making for Vulnerability Mapping of Flood Hazard: A Case Study of Pune City
Authors: Mundhe Nitin
Published: March 2019

Floods are natural risk with a very high frequency, which causes to environmental, social, economic and human losses. The floods in the town happen mainly due to human made activities about the blockage of natural drainage, haphazard construction of roads, building, and high rainfall intensity. Detailed maps showing flood vulnerability areas are helpful in management of flood hazards. Therefore, present research focused on identifying flood vulnerability zones in the Pune City using multi-criteria decision-making approach in Geographical Information System (GIS) and inputs from remotely sensed imageries. Other input data considered for preparing base maps are census details, City maps, and fieldworks. The Pune City classified in to four flood vulnerability classes essential for flood risk management. About 5 per cent area shows high vulnerability for floods in localities namely Wakdewadi, some part of the Shivajinagar, Sangamwadi, Aundh, and Baner with high risk.
Public discourse and government action in a controversial water management project: the damming of the Aposelemis River in Crete, Greece
Authors: Chifos Carla , Doxastakis Zaharias , Romanos Michael C.
Published: March 2019

The politics and practices of decision-making in a large dam project on the Greek island of Crete is investigated through the case study of the Aposelemis Dam, a European Union (EU)-funded development project to supply drinking water to three urban centers and major tourist destinations. Our study employs a modified version of the World Commission on Dams (WCD) evaluation framework. We compare the processes used in Greece with the best practices suggested by the WCD framework. Our study reveals three areas of weakness in this project. First, the political decision to build the dam took place in the absence of reliable hydrological studies and in the face of strong opposition from the residents, local governments, and professional organizations. Second, during the stages of planning, design, implementation, and operation of the project, the Greek government failed to follow transparent procedures in its deliberations. Affected residents and local governments in all the stages of the project were disregarded and mitigation of negative effects was negligible. And, third, the comprehensive sustainable regional development goals of the EU funding were never materialized.
Therapeutic Potential of Curcumin in the Treatment of Glioblastoma Multiforme
Authors: Shahcheraghi Seyed Hossein , Zangui Mahtab , Lotfi Marzieh , Ghayour-Mobarhan Majid , Ghorbani Ahmad , Jaliani Hossein Zarei , Sadeghnia Hamid Reza , Sahebkar Amirhossein
Published: March 2019

Glioblastoma multiforme (GBM) is the most common primary malignant brain tumor. Despite standard multimodality treatment, the highly aggressive nature of GBM makes it one of the deadliest human malignancies. The anti-cancer effects of dietary phytochemicals like curcumin provide new insights to cancer treatment. Evaluation of curcumin’s efficacy against different malignancies including glioblastoma has been a motivational research topic and widely studied during the recent decade. In this review, we discuss the recent observations on the potential therapeutic effects of curcumin against glioblastoma. Curcumin can target multiple signaling pathways involved in developing aggressive and drug-resistant features of glioblastoma, including pathways associated with glioma stem cell activity. Notably, combination therapy with curcumin and chemotherapeutics like temozolomide, the GBM standard therapy, as well as radiotherapy has shown synergistic response, highlighting curcumin’s chemo- and radio-sensitizing effect. There are also multiple reports for curcumin nanoformulations and targeted forms showing enhanced therapeutic efficacy and passage through blood-brain barrier, as compared with natural curcumin. Furthermore, in vivo studies have revealed significant anti-tumor effects, decreased tumor size and increased survival with no notable evidence of systemic toxicity in treated animals. Finally, a pharmacokinetic study in patients with GBM has shown a detectable intratumoral concentration, thereby suggesting a potential for curcumin to exert its therapeutic effects in the brain. Despite all the evidence in support of curcumin’s potential therapeutic efficacy in GBM, clinical reports are still scarce. More studies are needed to determine the effects of combination therapies with curcumin and importantly to investigate the potential for alleviating chemotherapy- and radiotherapy-induced adverse effects.
Recent Development in Indole Derivatives as Anticancer Agents for Breast Cancer
Authors: Kaur Kamalpreet , Jaitak Vikas
Published: March 2019

Background:

Breast Cancer (BC) is the second most common cause of cancer related deaths in women. Due to severe side effects and multidrug resistance, current therapies like hormonal therapy, surgery, radiotherapy and chemotherapy become ineffective. Also, the existing drugs for BC treatment are associated with several drawbacks such as poor oral bioavailability, non-selectivity and poor pharmacodynamics properties. Therefore, there is an urgent need for the development of more effective and safer anti BC agents.

Objective:

This article explored in detail the possibilities of indole-based heterocyclic compounds as anticancer agents with breast cancer as their major target.

Methods:

Recent literature related to indole derivatives endowed with encouraging anti BC potential is reviewed. With special focus on BC, this review offers a detailed account of multiple mechanisms of action of various indole derivatives: aromatase inhibitor, tubulin inhibitor, microtubule inhibitor, targeting estrogen receptor, DNA-binding mechanism, induction of apoptosis, inhibition of PI3K/AkT/NFkB/mTOR, and HDAC inhibitors, by which these derivatives have shown promising anticancer potential.

Results:

Exhaustive literature survey indicated that indole derivatives are associated with properties of inducing apoptosis and disturbing tubulin assembly. Indoles are also associated with the inhibition of NFkB/mTOR/PI3K/AkT and regulation of estrogen-mediated activity. Furthermore, indole derivatives have been found to modulate critical targets such as topoisomerase and HDAC. These derivatives have shown significant activity against breast cancer cells.

Conclusion:

In BC, indole derivatives seem to be quite competent and act through various mechanisms that are well established in case of BC. This review has shown that indole derivatives can further be explored for the betterment of BC chemotherapy. A lot of potential is still hidden which demands to be discovered for upgrading BC chemotherapy.
Inflammatory Bowel Disease Therapies Adversely Affect Fertility in Men- A Systematic Review and Meta-analysis
Authors: Banerjee Antara , Scarpa Marco , Pathak Surajit , Burra Patrizia , Sturniolo Giacomo C. , Russo Francesco P. , Murugesan Ram , D'Incá Renata
Published: March 2019

Background and Aims:

Sexual functions are sometimes adversely affected by the therapeutic
drugs delivered for treating IBD. Much attention has been focused on pregnancy/sexual issues in
women. Relatively less attention has been poured in to address this issue in men. This systematic review
assesses the drugs having potential detrimental effects on fertility in men.

Methods:

Three databases were searched by two researchers independently for potentially relevant
publications between 1964 to 2015 and 249 papers were retrieved. Studies that dealt with sexual problems
after IBD drugs administration were included in the purview of this review.

Results:

Fourteen studies with 327 human patients and 110 animals were analysed. Sulphasalazine
treated patients had lower spermatozoa count, lower sperm motility and higher risk of oligospermia
compared to mesalazine treated ones. Biologics seem to be safe to use while attempting to conceive
however, proper clinical studies reporting male fertility problems in IBD patients are lacking. Azathioprine
caused oligospermia but a meta-analytical approach was not possible due to heterogeneity in
studies. Some animal studies showed methotrexate affects abnormal testis structure and spermatogenesis.

Conclusion:

This study summarises the current literature and safety issues affecting fertility parameters
in men and animals treated with IBD therapeutic drugs, which can further assist clinicians in better
management of adult male IBD patients.
Brain Ageing, Cognition and Diet: A Review of the Emerging Roles of Food-Based Nootropics in Mitigating Age-related Memory Decline
Authors: Onaolapo Adejoke Yetunde , Obelawo Adebimpe Yemisi , Onaolapo Olakunle James
Published: March 2019

Background:

Age-related cognitive decline has been suggested to result from an increase in the brain neuron loss, which is attributable to continued derangement of the brain’s oxidant/ antioxidant balance. Increased oxidative stress and a concomitant decrease in the brain’s antioxidant defense system have been associated with functional senescence and organismal ageing. However, nature has configured certain foods to be rich sources of nootropic agents, with research showing that increased consumption of such foods or food ingredients may be protective against ageing-related memory decline. This knowledge is becoming increasingly valuable in an era when the boundary that separates food from medicine is becoming blurred. In this review, we examine extant literature dealing with the impact of ageing on brain structure and function, with an emphasis on the roles of oxidative stress. Secondly, we review the benefits of food-based antioxidants with nootropic effects and/or food-based nootropic agents in mitigating memory decline; with a view to improving our understanding of likely mechanisms. We also highlight some of the limitations to the use of food-based nootropics and suggest ways in which they can be better employed in the clinical management of age-related cognitive decline.

Conclusion:

While it is known that the human brain endures diverse insults in the process of ageing, food-based nootropics are likely to go a long way in mitigating the impacts of these insults. Further research is needed before we reach a point where food-based nootropics are routinely prescribed.
Large-Scale Self-Assembly in Weakly-Flocculated Suspensions
Authors: Dakskobler Aleš , Valant Matjaz
Published: March 2019

Background:

Studies on the formation of colloidal crystals in concentrated suspensions
have mainly been based on dispersed suspensions with a repulsive inter-particle potential of hard or
nearly hard spheres. The self-assembly in weakly-flocculated suspensions has still been unrealized.
Here, we report on the formation of ordered structures in concentrated suspensions of nearly-hard
spherical particles with weakly-attractive inter-particle interactions that are an order of magnitude
higher than the particles’ thermal energy.

Methods:

In our case, the self-assembly in such suspensions is not thermodynamically driven, but an
external shear force must be applied. The driving force for the particles’ ordering is an increase in the
inter-particle interactions. This manifests itself in a decrease in the average angle between the interparticle
interaction direction and the applied shear stress direction.

Results:

For a successful ordering into a large-scale closed packed assembly, the external shear force
must not exceed the inter-particle attractive interaction for the minimum possible average angle (as in
the closed packed structures) but be high enough to enable the particles to move in the highly loaded
suspension.

Conclusion:

The developed method for the self-assembly of the weakly flocculated systems can be
applied very generally e.g. a control over a composition of heterogeneous colloidal crystals, manufacturing
of the large-scale photonic crystals or preparation of very densely packed compacts of particles
needed for the production of sintered ceramics.
A Brief Review on E-skin and its Multifunctional Sensing Applications
Authors: Almansoori Mariam Turki , Li Xuan , Zheng Lianxi
Published: March 2019

Electronic skin (e-skin) is an artificial skin that mimics the sensing capabilities of human
skin, which brings many potential applications in robotics, artificial intelligence, prosthetics, and
health monitoring technologies. Many attempts associated with various mechanisms/approaches and
materials/structures have been developed to match the e-skins to the particular functions of specific
applications. Along the time, high sensitivity, mechanical flexibility/stretchability, multifunction, and
large area are common driving forces in the research area. New materials, with a variety of structures
and unique properties, offer a plenty of freedoms in designing and fabricating e-skins. Significant
progress has been made in recently years. This paper firstly reviews the most recent progress on nanomaterial-
based e-skins according to four major sensing mechanisms, with an emphasis on the effects
of various materials on the sensitivity and stretchability of e-skins. Then the paper updates the
progress and effort with respect to multifunctional e-skins and organic-thin-film-transistor based
large-area e-skins. Further development possibilities are also briefly discussed.
Determinants of Instagram Use: A Cross-sectional Questionnaire Study (Preprint)
Authors: Zimmermann Charlotte Marianne Maximiliane , Cheung Kei Long , de Vries Hein
Published: March 2019

BACKGROUND

Instagram counts over one billion users, yet the determinants behind its use, its addiction potential and relation to well-being are poorly understood.

OBJECTIVE

Our goal is to (1) investigate the demographic and socio-cognitive determinants of (low, medium and high) Instagram use, (2) the prevalence of Instagram addiction, (3) the relation between Instagram use, self-esteem and life satisfaction and (4) examine how these factors (1-3) explain Instagram usage intensity.

METHODS

A total of 237 participants (18-35 years) filled in an online questionnaire based on self-constructed scales measuring Instagram/social networking use and determinants of Instagram use, a short version of Young’s Internet Addiction Test, the Rosenberg Self-esteem scale and the Satisfaction with life scale. The data was analyzed with one-way ANOVAs, multiple regression analysis and Pearson’s correlations.

RESULTS

The model of the linear regression explained 41.2% of the variance of Instagram use in minutes, F(22, 214)=6.82, P<.001. Variance was mostly explained by social influence (β=.23, P<.001), perceived susceptibility to intensive use (β=.34, P<.001) and female sex (β=-.11, P=.047). Self-efficacy (r=0.48, P<.001), attitude pro (.45, P<.001), attitude con (r=0.33, P<.001) and social influence (r=0.36, P<.001) correlated moderately to largely with Instagram use in minutes. Age (r=-0.21, P=.001) and intention (r=0.16, P=.01) showed smaller effects, while self-esteem and life satisfaction showed no associations with Instagram use. In this study, 7.2% (N=14) participants classified as Instagram addicts while 37.5% (N=89) felt at substantial risk of using Instagram more than two hours daily. Time spent on Instagram daily was related to preferred Instagram functions and medium and high users used Instagram more passively than low ones.

CONCLUSIONS

Instagram use was shown to be especially pronounced among younger females with lower self-efficacy that held strong positive and negative attitudes towards Instagram. Moreover, passive use patterns, higher social influence and perceived susceptibility towards Instagram promoted Instagram use. While many users experienced drawbacks of Instagram use in isolated areas like distraction at work or overthinking one’s self-presentation, addiction prevalence was low and no relation between Instagram use and self-esteem or life satisfaction was found. Female sex, perceived susceptibility to intensive use and social influence explained variances in daily Instagram use in minutes the best.
Dinamika Resiliensi Ibu Single parent dengan Anak Tuna Ganda
Authors: Hasanah Uswatun , Retnowati Sofia
Published: March 2019

The purpose of this research is to assess the dynamics of resilience on single-parent mother who has a child with double-handicap, starting from the initial phase before and after the diagnosis of double-handicap, stress phase because of the escapement of husband and several risk factors that may arise, up to the phase of adaptation and strengthening. This research used the qualitative method by conducting observation and interview to three informants who domiciled in Kendari. The results showed that there are risk factors which become the initial process in the dynamics of resilience on single-parent mother who has a child with double-handicap, such as family disfunction, financial and social problems, parenting stress on the mother and a belief that mystical factor was causing the problems. Those problems raised negative impacts toward the psychological and physical condition. The attempt made to solve the problems was centered on problem focused coping and emotional focus coping by gaining support from the environment and doing daily activities. The processes of raising and strengthening of resilience on single-parent mother who has a child with double-handicap is also supported by protective factors such as hopefulness, learning from experience, the bond between child and mother, and religious belief.
Claudia Agostoni y Elisa Speckman (editoras). Modernidad, tradición y alteridad. La ciudad de México en el cambio de siglo (XIX-XX)
Authors: ILLADES CARLOS
Published: March 2019

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