bluuebunny/crossref_metadata_2025_split huggingface dataset:
HUBUNGAN TINGKAT STRESS DENGAN SIKLUS MENSTRUASI PADA REMAJA PUTRI
Authors: Anjarsari Nurul , Sari Etika Purnama 
Published: June 2020

Pendahuluan : Psikologis pada usia remaja dapat mempengaruhi emosi remaja yang dapat menyebabkan timbulnya stress. Stress pada remaja perempuan salah satunya dapat mengganggu siklus menstruasi. Tujuan penelitian untuk mengetahui hubungan tingkat stress dengan siklus menstruasi pada remaja.Metode : Penelitian ini menggunakan pendekatan cross sectional. Sampel dalam penelitian adalah 92 remaja putri kelas 2 SMA Wachid Hasyim 1 Surabaya yang diambil dengan teknik Simple Random Sampling. Instrumen pengumpulan data tingkat stres dengan menggunakan Kuesioner DASS 42 dan kuesioner siklus menstruasi, serta uji korelasi Chi-Square.Hasil : Hasil uji korelasi Chi-Square didapatkan nilai p=.016. Hal ini berarti terdapat hubungan antara tingkat stress dengan siklus menstruasi.Kesimpulan : Terdapat berbagai macam factor yang berkaitan dengan ketidakteraturan siklus menstruasi pada remaja dimana salah satunya adalah stress. Perlu dilakukan penelitian lagi terkait dampak stresss terhadap masalah menstruasi yang lain seperti durasi, dismenore dan lainnya untuk memahami lebih jauh dampak stress terhadap masalah menstruasi pada remaja. ABSTRACTIntroduction: Psychological changes in adolescence can affect adolescent emotions that can cause stress. Stress in adolescent one of which can disrupt the menstrual cycle. The purpose of this study was to determine the relationship of stress levels with the menstrual cycle in adolescents.Method: his study uses a cross sectional approach. The sample in this study was 92 adolescents of Wachid Hasyim 1 Surabaya High School who were taken by using Simple Random Sampling technique. Instrument for collecting stress levels using the DASS 42 Questionnaire and menstrual cycle questionnaire.Results: . This study tested using Chi-Square correlation test. Chi-Square correlation test results obtained p-value = .016. This means that there is a relationship between stress levels and the menstrual cycle.Conclusion: There are various factors related to irregular menstrual cycles in adolescents where one of them is stress. Further study needs to be conducted related to the impact of stress on other menstrual problems such as duration, dysmenorrhea and others to further understand the impact of stress on menstrual problems in adolescents.
Autonomous Valve Controls Excess Water, Gas Production To Increase Oil Recovery
Authors: Mathiesen Vidar , Brough Brent 
Published: June 2020

Increasing sensitivity to oil price fluctuation requires operators to reduce costs of operation. A key component is collaborative management by operators and suppliers to reduce cost over the full life cycle of the operation. Much of the focus is on the equipment-purchasing strategy; nonetheless, effective technology such as an autonomous inflow control valve could also benefit the operating expenditure (OPEX) savings by enhancing oil recovery and reducing processing costs of excessive unwanted water and gas in surface facilities.
OPEX comprises labor, chemicals, consumables, infrastructure maintenance, transportation, disposal, and other utilities. Capital expenditure (CAPEX) may also be reduced for long-term projects, which generally comprise infrastructure such as pipelines, pumps, disposal wells, ponds/storage treatment facilities, and other associated utilities infrastructure.
The average cost for handling produced water starts from about $1.50/bbl, depending on the geographical location of the operation. Such costs may justify an assessment of an autonomous inflow control valve (AICV) to reduce unwanted water and gas to achieve OPEX savings.
Horizontal wells are a proven option to maximize reservoir contact in certain situations. A challenge is often early water breakthrough in less than 6 months from starting production, and then progressively producing very-high water cuts, often 95%, for long periods of times thereafter. Inflow control device (ICD) technology has demonstrated potential in improving recovery in horizontal oil wells by delaying the gas and/or water breakthrough. However, ICDs cannot restrict water effluents once breakthrough occurs. A new generation of inflow control technology known as an AICV can balance the production flow and choke and shut the water-effluent zones once breakthrough occurs.
Basis of Design
The design is based on the Hagen-Poiseuille equation and Bernoulli’s principle. It uses the difference in fluid-flow behavior in the laminar- and the turbulent-flow restrictor to differentiate the pressure drop using the mobility ratio between oil, water, and gas. Light-viscosity fluids such as water and gas have high mobility and allow the AICV to detect the mobility difference, then choke and shut the main inflow area in the valve autonomously. Fig. 1 illustrates the construction of the valve in open positions, showing the direction of flow with arrows and the P1, P2, and P3 pressure locations. The inlet pressure is represented by P1: 2-5% of the main flow will move through the laminar-flow element (LFE) that will reduce the pressure to P2. Further pressure reduction occurs in the turbulent-flow element (TFE) to P3 as the tubing pressure. The differential pressure in LFE reacts to the piston’s effective area, resulting in a force balance around the piston to control the valve’s function (e.g., to open, choke, or close the main flow).
Technology Focus: Stimulation (June 2020)
Authors: Chang Frank 
Published: June 2020

The economic condition of the oil and gas industry is tighter than ever. Optimizing well productivity to maintain cost effectiveness is on every operator’s mind. Enhancing well productivity requires more-detailed analysis, more measurements, and even-more-advanced products and technologies, which all cost more money. Doing more and reducing cost can be a dilemma. This is the time when properly choosing sound technologies is critical to improve efficiency and increase success rates. Several well-stimulation products and techniques have been seen to benefit well productivity from recent field trials and implementations in carbonate reservoirs, including simpler acid fluid systems, integrated work flows, and coiled-tubing bottomhole assemblies.
Emulsified acid has been a preferred carbonate-stimulation fluid for 30 years. Clearly, mass transfer can be retarded significantly by the emulsion form for deeper live-acid penetration in matrix- and fracture-acidizing applications. The quality of the emulsified acid is sensitive to how it is mixed. In the laboratory, slowly adding acid into oil, mostly diesel, containing surfactant while blending is required to achieve good emulsion stability. Field practice is another story. The large amount of emulsified acid is normally batch-mixed in the service company yard or at the wellsite by circulation pumps and tanks. The mixing energy used in the laboratory is difficult to match in the field. Consequently, the consistency of the final emulsified acid pumped can vary from well to well. Recently, single-phased-acid systems have been developed to simplify the fluid preparation and to make the product performance more robust. Various single-phased acids are provided by service companies or even operators themselves using different formulations to achieve the effect of retardation.
Another important technology for successful acidizing, especially in horizontal wells or highly heterogeneous reservoirs, is diversion. Many diverters have been used. Evaluation of diversion during the treatment remains rudimentary. Pressure humps are used to infer diversion without good confirmation of how effective the diversion actually is. More-accurate information about fluid rheological and friction characteristics is needed to evaluate the downhole-pressure behavior and, hence, quantified diversion results. The term “diversion” is often used interchangeably with “placement.” Proper placement can be achieved by means other than diverting materials. Jetting is believed to place acid effectively in matrix stimulation without chemical diverters.
Each technology costs additional money at the early stage. When they are routinely used, fully integrated in work flows, and eventually linked with automation, true cost effectiveness of the stimulation treatments can be realized. The investment made today, therefore, will bear fruits in the future.
Technology Focus: Hydraulic Fracturing (June 2020)
Authors: Rahim Zillur 
Published: June 2020

A good design of a multistage-fracture (MSF) treatment must be implemented effectively to ensure expected production from a fracture treatment. Knowing that downhole tools are correctly deployed and function as planned in MSF, therefore, is important. The setting of packers, opening and closing of frac ports, shifting of frac sleeves, and isolating with ball drops in openhole assemblies are some of the many major events that need to be monitored closely to ensure smooth operations. As such, wellbore pressure is monitored at surface and is the primary method for deter-mining if tools are functioning properly and if the stimulation program is being executed correctly. As wellbores become longer, numerous fracturing stages are conducted on a single wellbore, and multiple service companies are involved on site to support a successful stimulation program, pinpointing issues or challenges when they arise becomes more difficult - particularly if the pressure signature is unclear, hard to interpret, or not present at all. These ambiguities can lead to treatment uncertainty, costly delays, or huge remedial efforts. Being uncertain and missing out on a few stages in the treatment can have major effects on production, ultimate recovery, and the overall field-development plan.
A new real-time-visualization (RTV) technology combined with high-resolution pressure reading and acoustic sensors is being used to overcome operational difficulties and to optimize stimulation efforts by reducing uncertainty. The RTV technology has a minimal surface footprint, can be deployed rapidly, is self-contained, and does not interfere with concurrent on-site operations. The use of this technology significantly improves the entire fracturing process, thereby optimizing well production.
RTV has been used in more than 10 countries, proving to be an effective tool for confirming successful operations or expediting the troubleshooting of operational issues. In one case, an operator was facing challenges in establishing connectivity with the reservoir when a toe sleeve failed to open. The RTV and acoustic system provided the operator valuable insight; the problematic sleeve was identified and opened with a coiled-tubing-deployed ball-seat activator immediately, preventing a remedial operation of milling out the entire completion system, which would have been very costly.
RTV has also been used offshore. Monitoring an openhole multistage stimulation system that was using ball-activated sliding sleeves, the RTV system confirmed all critical events, such as ball launches, landings, and sleeve shifts. The system prevented unnecessary use of extra balls or coiled tubing in cases where the pressure signature of sleeve shifts was not present.
Although many technologies and approaches are available to help with real-time monitoring and troubleshooting, incorporating this RTV system provides critical data to correct issues effectively and improves operational efficiency, giving operators greater confidence in decisions relating to downhole events.
Overcoming Challenges in Chemical EOR During Polymer Breakthrough
Authors: Carpenter Chris 
Published: June 2020

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 194689, “Challenges in Selection and Use of Production Chemicals With Chemical EOR Operations During Polymer Breakthrough Phase,” by Robert Zagitov, Panneer Selvam Venkat, and Ravindranthan Kothandan, Cairn Oil and Gas, et al., prepared for the 2019 SPE Oil and Gas India Conference and Exhibition, Mumbai, 9-11 April. The paper has not been peer reviewed.
In chemical enhanced oil recovery (EOR), challenges are expected regarding production chemistry and production-facilities operations. Partially hydrolyzed polyacrylamide (HPAM) is used widely for controlling mobility ratios. Complex in water chemistry and rich in positively charged divalent ions, flooded polymer, having a negative charge, interacts with divalent ions of produced water (PW). The complete paper discusses the importance of adequate preparation and the approaches used to overcome challenges of EOR operations, including handling back-produced polymer.
Introduction
The Mangala field in northwest India, discovered in January 2004, is part of the Barmer Basin. The primary reservoir unit in this field is the Fatehgarh group, a high-quality quartzose sandstone reservoir having high net-to-gross ratio, high porosity (21-28%), and multidarcy permeability (200 millidarcy to 20 darcy) with an average permeability of approximately 5 darcy. The reservoir contains waxy crude with gravity ranging from 20 to 28 °API. A primary recovery efficiency of less than 10% stock-tank oil initially in place is estimated on the basis of simple depletion; thus, the base field-development plan envisaged implementation of waterflooding from the start of production to maintain reservoir pressure and sweep reserves. Detailed laboratory studies have established that aqueous-based chemical EOR processes are best suited for these viscous oil fields.
Full-field polymer flooding has been implemented in the Mangala field, with an injection at the time of writing of nearly 400,000 B/D of polymerized injection water (IW) with average polymer concentration of approximately 2,500 ppm. HPAM is mixed with source water to create a mother solution of 15,000-ppm concentration at a central polymer facility and is distributed through a pipeline network to 15 well pads, where it is diluted with IW to achieve a viscosity of approximately 30 cp for injection. Artificial lift is achieved either by jet pump or electrical submersible pump. Average water cut is 80% at the time of writing.
Predictive factors of selective mineralocorticoid receptor antagonist treatment in chronic central serous chorioretinopathy
Authors: Gergely Róbert , Kovács Illés , Récsán Zsuzsanna , Sándor Gábor László , Czakó Cecília , Nagy Zoltán Zsolt , Ecsedy Mónika 
Published: June 2020

Abstract
Purpose: To compare the macular morphology of good and poor responders to eplerenone treatment in chronic central serous chorioretinopathy (CSCR) patients. Methods: 30 eyes of 29 patients with chronic CSCR were treated with 50 mg/day oral eplerenone and followed up for one year. The integrity of outer retinal layers at baseline was assessed using optical coherence tomography. Patients who showed complete resolution of subretinal fluid at one year were assigned to the good responder group (Group 1), whilst those who showed moderate or no resolution were classified as poor responders (Group 2). Results: Ellipsoid zone interruption, ELM interruption and hyperreflective foci in outer segment (OS) and outer nuclear layer (ONL) was significantly more frequent in Group 2 than in Group 1 (p<0.05 for all parameteres). Outer segment elongation was significantly more frequently seen in Group 1 than in Group 2 (p<0.05) Multivariable regression analysis showed that intact ellipsoid zone at baseline is an independent predictor of good therapeutic response, with an odds ratio of 26.00 (95% CI: 3.69–183.45; p=0.001) after controlling for the effect of hyperreflective foci and ELM integrity.Conclusion: There is higher chance of the resolution of subretinal fluid after eplerenone treatment in CSCR patients with intact outer retinal layers at baseline. Baseline morphologic evaluation of the outer retinal layers on OCT scans can be useful in predicting the response to mineralocorticoid receptor antagonist therapy in these patients.
Pertussis outbreak in Southern Ethiopia: challenges of detection, management and response
Authors: Mitiku Aychiluhim Damtew , Argaw Mesele Damte , Desta Binyam Fekadu , Tsegaye Zergu Taffesse , Atsa Afework Ayele , Tefera Bekele Belayihun , Teferi Ephreme , Rogers Deirdre , Ali Ismael , Gebeyehu Asrat , Anjulo Desta , Abate Derebe Tadesse , Sendeku Agegnehu Gebru , Mulowa Rudzani 
Published: June 2020

Abstract
Background: Despite the availability of effective vaccines, pertussis remains endemic with high fatality rates in low and middle-income countries (LMIC).This study aims to describe an outbreak of pertussis in a health district of Ethiopia. The study highlights the challenges faced by the health system in identifying pertussis cases and appropriately responding to the outbreak at the district level. Methods: a descriptive cross-sectional study was conducted using data sourced from the District Public Health Emergency and Management (PHEM) surveillance service and outbreak management field reports. Stratified attack rates and fatality rates for pertussis are described. Systemic problems leading to the outbreak are explored and narrated. A modified CDC pertussis case definition was employed with a polymerase chain reaction used to confirm cases. Results: From September 2018 to January 2019, 1840 suspected, probable, and confirmed pertussis cases and six deaths were identified. Pertussis cases ranged from 1 month to 51 years in age and an outbreak occurred in 14 out of the 24 villages of Dara Malo district. The overall attack rate was 1708 per 100,000 population with a fatality rate of 3.3 per 1,000 pertussis cases. The highest attack rate of 12,689/100,000 was seen in infants. Among confirmed, probable and suspected pertussis cases, only 41.1% had completed the three-dose pertussis vaccine's primary schedule. The household survey revealed the population coverage of 73.4% and 40.8% for Pentavalent vaccine dose one and three respectively. Investigations suggested the existence of a poor cold chain management system in the study area. Conclusions: There is an urgent need to build capacity to strengthen routine vaccination services and improving the maintenance of the vaccine cold chain. Other Low-and Middle -Income Countries (LMICs), are urged to take lessons learned from this outbreak and strengthen their own vaccination programs and capacitate health workers to manage local outbreaks.
IgG anti-hinge antibodies against IgG4 F(ab’)2 fragments generated using pepsin are useful diagnostic markers for rheumatoid arthritis: implications of the possible roles of metalloproteinases and IgG subclasses in generating of immunogenic hinge epitopes.
Authors: Ota Toshiyuki , Ota Shun-ichiro , Uchino Ayumi , Nagano Shuji 
Published: June 2020

Abstract
Background. Pepsin agglutinators, discovered over 50 years ago, have been recently referred to as anti-hinge antibodies (AHAs) because of their reaction with the IgG hinge epitope. AHAs have different reactivity for each hinge epitope generated by each protease that cleaves the hinge region at different sites. Moreover, AHAs have different reactivity against different hinge epitopes derived from each IgG subclass even when the same protease is used. Since the expression of matrix metalloproteinase-3 (MMP-3) is enhanced in rheumatoid arthritis (RA), AHA production could also be increased. The purpose of this study was to determine whether the levels of AHAs against IgG hinge epitopes produced by MMP-3 are elevated in RA.Methods. The serum levels of IgG or IgA AHAs against the IgG1/IgG4 F(ab’)2 fragments, generated by either MMP-3 or pepsin, was measured using ELISA in 111 patients with RA and 81 healthy controls (HC). Receiver operating characteristic (ROC) analysis was used for obtaining optimal cutoff values and cutoff values indicating high specificity (>95%) of the AHA. The targeted epitope of a specific AHA was investigated through inhibition ELISA. Results. Seven AHAs were statistically higher in RA patients than HC, except IgG AHA against IgG1 F(ab’)2, which was generated by MMP-3 proteolytic cleavage. The areas under the ROC curve were of 0.66--0.80, although the sensitivities at high specificity were low (5.4--24.3%). The cumulative number of positive AHAs in each individual was statistically higher in RA patients than HC, suggesting the extreme extent of AHA repertoires in RA. Inhibition studies revealed that IgG AHAs against IgG4 F(ab’)2 fragments generated by pepsin cross-reacted with IgG1 F(ab’)2 fragments generated by pepsin. Multivariate logistic regression analysis identified the IgG AHA against IgG4 F(ab’)2 fragments generated by pepsin as an independent variable for RA diagnosis, even in RA patients who were negative for both RF and ACPA (odds ratio 1.18, 95% CI: 1.06−1.32; P=0.003). Additional experiments using non-RA patients finally strengthened the diagnostic utility.Conclusion. In RA patients, we observed diversification and amplification of AHA repertoires and diagnostic utility of the specific AHA against IgG4 F(ab’)2 fragments generated by pepsin but not MMP-3.
Early exposure to environmental sounds and the development of cortical auditory evoked potentials of preterm infants during the first three months of life
Authors: Cavalcanti Hannalice Gottschalck , Nunes Aryelly Dayane da Silva , Cunha Brenda Karla Silva da , Alvarenga Kátia de Freitas , Balen Sheila Andreoli , Pereira Antonio 
Published: June 2020

Abstract
Objective: Preterm infants are exposed earlier than their term counterparts to unattenuated sounds from the external environment during the sensitive period of the organization of the auditory cortical circuitry. In the current study, we investigate the effect of preterm birth on the course of development of auditory cortical areas by evaluating how gestational age (GA) correlates with the latency of the P1 component of the cortical auditory evoked potential (CAEP) of two experimental groups measured at one or three months of age. Results: Our sample consisted of 23 infants delivered at GA ranging from 31.28-41.42 weeks and separated into two groups evaluated transversally at one or three months of corrected age (CA). In the group evaluated at one-month CA, the latency of the component P1 was similar in both terms and infants classified as late-preterm (GA>32 weeks). However, in the group evaluated at three months CA, P1 latency was significantly smaller in preterms. These preliminary results suggest an acceleration of the development of auditory cortical pathways in preterms, probably due to their early exposure to socially relevant auditory stimuli from the external environment.