bluuebunny/crossref_metadata_2025_split huggingface dataset:
A novel mechanism of hippocampal LTD involving muscarinic receptor-triggered interactions between AMPARs, GRIP and liprin-α
Authors: Dickinson Bryony A , Jo Jihoon , Seok Heon , Son Gi Hoon , Whitcomb Daniel J , Davies Ceri H , Sheng Morgan , Collingridge Graham L , Cho Kwangwook 
Published: June 2009

Abstract

Background
Long-term depression (LTD) in the hippocampus can be induced by activation of different types of G-protein coupled receptors, in particular metabotropic glutamate receptors (mGluRs) and muscarinic acethycholine receptors (mAChRs). Since mGluRs and mAChRs activate the same G-proteins and isoforms of phospholipase C (PLC), it would be expected that these two forms of LTD utilise the same molecular mechanisms. However, we find a distinct mechanism of LTD involving GRIP and liprin-α.

Results
Whilst both forms of LTD require activation of tyrosine phosphatases and involve internalisation of AMPARs, they use different molecular interactions. Specifically, mAChR-LTD, but not mGluR-LTD, is blocked by peptides that inhibit the binding of GRIP to the AMPA receptor subunit GluA2 and the binding of GRIP to liprin-α. Thus, different receptors that utilise the same G-proteins can regulate AMPAR trafficking and synaptic efficacy via distinct molecular mechanisms.

Conclusion
Our results suggest that mAChR-LTD selectively involves interactions between GRIP and liprin-α. These data indicate a novel mechanism of synaptic plasticity in which activation of M1 receptors results in AMPAR endocytosis, via a mechanism involving interactions between GluA2, GRIP and liprin-α.
Can health care databases be used to identify incident cases of osteonecrosis?
Authors: Vlad Steven C , Felson David T , Miller Donald R 
Published: June 2009

Abstract
Introduction
Osteonecrosis (ON) is a rare disease associated with alcohol and glucocorticoid use. Identifying additional risk factors is difficult as the number of cases at any single center is small. We investigated whether data available in large health care databases can be used to identify incident ON cases.

Methods
Using data from the Boston Veterans Affairs Healthcare system, we identified potential cases of ON. These records, including available radiographs and reports, were reviewed. Using published criteria, we evaluated whether the subjects had confirmed ON (radiographs/reports met criteria), incident ON (onset of symptoms within 6 months of first code), or prevalent ON (onset more than 6 months prior to first code or onset could not be determined). We tested different definitions for incident ON using information derived from administrative data. These were compared to the 'gold standard' (record review) and positive predictive values (PPVs) were derived. Since PPVs for incident cases were low, we found the number of incident cases expected for every 1,000 potential cases identified, using the definitions as an initial screening tool to reduce the number of medical records that required examination.

Results
We identified 87 potential cases. No case of jaw ON was identified. Only 15 (17%) incident cases of ON were identified. PPVs never exceed 50% for incident ON. However, if we used the definition '(at least 1 inpatient ON code) and (no prior codes for osteoarthritis)' as an initial screen, then for every 1,000 records, we would need to review only 150 to find 69 incident cases.

Conclusions
Though the precise PPVs we found may not be generalizable to other databases, we believe that administrative data alone should not be used to identify incident cases of ON without confirming the diagnosis through a review of medical records. By applying the above definition, the number of records requiring review can be markedly reduced. This method can be used to find cases for valid case-control studies of risk factors for ON.
Effect of Support on the Suppression of Hot Spot Formation in the Partial Oxidation of Methane
Authors: Shishido Tetsuya , Morishima Reina , Yoshinaga Yusuke , Hasegawa Sadao , Tanaka Tsunehiro 
Published: June 2009

Abstract
Ni-based catalysts supported on perovskite oxides and α-Al2O3 were prepared to investigate catalytic performance and catalyst bed temperature profile in the partial oxidation of methane. Ni/LaAlO3 showed high activity and remarkably suppressed hot spot formation in the catalyst bed even at high space velocity. The effect of support is discussed on the basis of the state of Ni.
Serological immunity to diphtheria and tetanus in healthy adults in Delhi, India
Authors: Saxena Sonal , Jais Manoj , Dutta Renu , Dutta A K 
Published: June 2009

Widespread childhood immunization with DPT (diphtheria, pertussis and tetanus) has largely eradicated diphtheria and tetanus from many countries. The reduction in the circulation of toxigenic strains has resulted in less natural boosting of adult immunity. As a result, the adult population in countries with high childhood immunization coverage have become susceptible to the disease. The duration of immunity after primary immunization to diphtheria and tetanus is limited and a reduction in immunity is common in adults. With this perspective, the present study was carried out on a random serum sample of 255 healthy individuals aged 20-50 years. The serum samples were tested for immunoglobulin G levels against diphtheria and tetanus by enzyme immuno assays. Fifty-three per cent of adults were unprotected; 22 % were seen to have only a basic protection against diphtheria; 25% were protected against both diseases; and 47% were susceptible to tetanus. The susceptibility was seen to increase with age. To avoid epidemics in the future, immunity must be improved. It is important to treat even the most trivial wound with care and tetanus toxoid immunization. Also, it is necessary to monitor the community for immunity to diphtheria using standard techniques in order to undertake epidemiological surveillances of, and prevention from, these dreadful diseases.
Outcomes of Perioperative β-Blockade in Patients Undergoing Noncardiac Surgery: A Meta-Analysis
Authors: Talati Ripple , Reinhart Kurt M , White C Michael , Phung Olivia J , Sedrakyan Art , Kluger Jeffrey , Coleman Craig I 
Published: June 2009

Background: Several studies have evaluated the impact on myocardial infarction (MI), stroke, and overall mortality of perioperative β-blocker use in patients undergoing noncardiac surgery (NCS). However, most studies did not have adequate sample size and statistical power and were therefore underpowered to adequately evaluate these end points. Objective: To conduct a meta-analysis to determine the balance of benefits and harms associated with perioperative β-blocker use in NCS. Methods: A systematic literature search of MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials was conducted from January 1960 through February 2009. Manual reference search was performed to identify additional relevant trials. Randomized, double-blinded, placebo-controlled trials comparing the use of β-blockars with placebo; using β-blockers perioperatively in β-blocker–naïve patients undergoing NCS; and evaluating endpoints of Ml, stroke, or all-cause mortality were included. Results: Six trials (N = 10,183) met our inclusion criteria. Perioperative β-blocker use was associated with a significant reduction in patients' odds of developing Ml (OR 0.74, 95% CI 0.61 to 0.89) but a significant increase in odds of developing stroke (OR 1.98, 95% CI 1.23 to 3.20) and also a nonsignificant increase in mortality (OR 1.21, 95% CI 0.98 to 1.49) versus placebo. Control-rate meta-regression determined that patients with highest baseline odds of stroke had decreased relative odds of having a stroke with a β-blocker versus placebo (β coefficient –0.97; 95% credible interval –1.04 to –0.90). Conclusions: When perioperative β-blockers are used in NCS patients, there is a trade-off between reduction in MI and increase in stroke, with a troubling trend toward an increase in mortality. Patients with lower baseline odds of developing stroke appear to be at greater risk of β-blockgr–induced stroke.
Delirium in a Patient with Toxic Flecainide Plasma Concentrations: The Role of a Pharmacokinetic Drug Interaction with Paroxetine
Authors: Tsao Yvonne Y , Gugger James J 
Published: June 2009

Objective: To describe a case of flecainide-induced delirium associated with a pharmacokinetic drug interaction with paroxetine. Case Summary: A 69-year-old white female presented to the emergency department with a history of confusion and paranoia over the past several days. On admission the patient was taking carvedilol 12 mg twice daily, warfarin 2 mg/day, folic acid 1 mg/day, levothyroxine 100 μg/day, pantoprazole 40 mg/day, paroxetine 40 mg/day, and flecainide 100 mg twice daily. Flecainide had been started 2 weeks prior for atrial fibrillation. Laboratory test findings on admission were notable only for a flecainide plasma concentration of 1360 μg/L (reference range 200–1000). A metabolic drug interaction between flecainide and paroxetine, which the patient had been taking for more than 5 years, was considered. Paroxetine was discontinued and the dose of flecainide was reduced to 50 mg twice daily. Her delirium resolved 3 days later. Discussion: Flecainide and pharmacologically similar agents that interact with sodium channels may cause delirium in susceptible patients. A MEDLINE search (1966–January 2009) revealed one in vivo pharmacokinetic study on the interaction between flecainide, a CYP2D6 substrate, and paroxetine, a CYP2D6 inhibitor, as well as 3 case reports of flecainide-induced delirium. According to the Naranjo probability scale, flecainide was the probable cause of the patient's delirium; the Horn Drug Interaction Probability Scale indicates a possible pharmacokinetic drug interaction between flecainide and paroxetine. Conclusions: Supratherapeutic flecainide plasma concentrations may cause delirium. Because toxicity may occur when flecainide is prescribed with paroxetine and other potent CYP2D6 inhibitors, flecainide plasma concentrations should be monitored closely with commencement of CYP2D6 inhibitors.
Maternal serum adiponectin multimers in patients with a small-for-gestational-age newborn
Authors: Mazaki-Tovi Shali , Romero Roberto , Vaisbuch Edi , Erez Offer , Mittal Pooja , Chaiworapongsa Tinnakorn , Kim Sun Kwon , Pacora Percy , Yeo Lami , Gotsch Francesca , Dong Zhong , Yoon Bo Hyun , Hassan Sonia S. , Kusanovic Juan Pedro 
Published: June 2009

Abstract

Objective: Several mechanisms of disease have been implicated in the pathophysiology of small-for-gestational-age (SGA) including an anti-angiogenic state, and an exaggerated intravascular pro-inflammatory response. Adiponectin plays a role in a wide range of biological activities including those that have been implicated in the pathophysiology SGA. Thus, the aim of this study was to determine if third trimester adiponectin concentrations differed between women with normal weight infants and those with an SGA neonate.

Study design: This cross-sectional study included women with: 1) a normal pregnancy (n=234); and 2) an SGA neonate (n=78). SGA was defined as a birth weight below the 10th percentile for gestational age at birth. The study population was further stratified by first trimester body mass index (BMI) (normal weight <25 kg/m2 vs. overweight/obese ≥25 kg/m2). Maternal serum adiponectin multimers [total, high-molecular-weight (HMW), medium-molecular-weight (MMW) and low-molecular-weight (LMW)] concentrations were determined by ELISA. Non-parametric statistics were used for analyses.

Results: 1) The median maternal serum concentrations of total, HMW and MMW adiponectin were significantly lower in patients with an SGA neonate than in those with normal pregnancies; 2) patients with an SGA neonate had a significantly lower median HMW/total adiponectin ratio and higher median MMW/total adiponectin and LMW/total adiponectin ratios than those with a normal pregnancy; 3) among patients with an SGA neonate, neither maternal serum concentrations of adiponectin multimers, nor their relative distribution differ between normal weight and overweight/obese patients.

Conclusion: 1) Pregnancies complicated by an SGA neonate are characterized by a alterations in the maternal serum adiponectin multimers concentrations and their relative abundance; 2) the findings reported herein suggest that maternal adipose tissue may play a role, in the pathogenesis of SGA.
Health development program package and its effectiveness on the students in high schools and universities
Authors: Fritz Péter 
Published: June 2009

A dolgozat témája az egészségi állapot komplex fejlesztésének hatékonyságvizsgálata.
Célkitűzések:
1. Összeállítani az egyén bio-pszicho-szociális állapotáról reális képet adó vizsgálati csomagot. 2. Meghatározni az általam kifejlesztett és a vizsgálati csomagra épülő egészségterv egészségfejlesztő hatékonyságát. 3. Bizonyítani a komplex egészségfejlesztési programcsomag hatékonyságát. 4. Meghatározni egy többváltozós egészségmodellt.
Módszerek:
A kutatásban önként jelentkezett egyetemisták vettek részt, N=125 (29 férfi, 96 nő). Három csoportba soroltam a hallgatókat, véletlenszerű kiválasztást alkalmazva, majd felmértem az egészségi állapotukat a program előtt és a program végeztével is. Az I-es és II-es csoport egészségtervet kapott, az I-es csoport pedig részt vett a 3 hónapos egészségfejlesztési programban. A III. csoport volt a kontrollcsoport. Az egészségfejlesztési programcsomag egészségtervet, edzéstervet, pszichotréninget, személyi edzést és tanácsadást tartalmazott.
Eredmények:
A hallgatók az egészségük számára értékesebb és hatékonyabb mozgásos tevékenységeket választanak és azt rendszeresebben űzik, valamint csak egészségtervvel rendelkezők csoportjában is megfigyelhető a heti mozgással eltöltött alkalmak számának emelkedése. A fejlesztési csoportok szubjektív egészségi állapotának növekedése szignifikánsnak mutatkozott (p
1
= 0,02; p
2
= 0,004). A vitális kimerültség az I-es csoportnál szignifikánsan javult, a II-es csoportban tendencia. A hangulati állapot 2 felmérése között szignifikáns különbség van (Wilcoxon). A hallgatók a program végére 13,4%-kal közelebb kerültek a maximális teljesítőképességükhöz. A heti mozgásgyakoriság a legjelentősebb tényező az egészségi állapot szempontjából a BMI, BDI-hez képest, másfélszeresre javítja az esélyét annak, hogy az egészségi állapot jó kategóriájába kerül valaki.
Következtetések:
Az egészségterv és/vagy a személyi, kis csoportos rekreációs edzés a kipróbált kiválasztási, felkészítési és alkalmazott módszerekkel hatékony formában tud működni.
Critical Conditions for Effective Sand-Sized Solids Transport in Horizontal and High-Angle Wells
Authors: Duan Mingqin , Miska Stefan , Yu Mengjao , Takach Nicholas , Ahmed Ramadan , Zettner Claudia 
Published: June 2009

Summary
Effective removal of small, sand-sized solids is critical for successful drilling and completion operations in sand reservoirs. Recent experience in extended-reach drilling also indicates that inefficient transport of smaller cuttings is a main factor for excessive drag and torque. This study was undertaken to determine two critical conditions for efficient transport of small solids. The two conditions are represented by the critical resuspension velocity (CRV), the minimum fluid velocity necessary to initiate solids-bed erosion, and the critical deposition velocity (CDV), the minimum fluid velocity required to prevent bed formation.
Experiments were conducted in a field-scale flow loop (8 × 4.5 in., 100 ft long) to determine CRV and CDV for 0.45-mm and 1.4-mm sands in different fluids over a range of bed heights and hole inclinations. The results show that, depending on sand size and fluid properties, CDV is approximately two to three times larger than CRV. Water is more effective than low-concentration polymer solutions for bed erosion. However, polymer solutions are more helpful than water in preventing bed formation. This indicates the need for different drilling fluids for cleanout and drilling operations.
A mechanistic model was developed to predict CRV for a solids bed. Both experimental and theoretical results indicate the importance of interparticle forces that are incorporated into the model. The model accounts for drillpipe eccentricity in any direction in an annulus, which is consistent with experimental observations. The model predictions are in good agreement with experimental results. Existing CDV correlations developed for larger cuttings were verified by experimental data for sands. The differences are approximately 25%. Results in this study will be useful not only in drilling and completion through sand reservoirs, but also in extended-reach drilling and sand control.
Gauge, Cutting Structure, Torque Control Components—What Really Counts for Optimal Tool Face Control With FC Drill Bits?
Authors: Barton Steven , May Henry , Johnson Simon 
Published: June 2009

Summary
Tool-face control is widely regarded as one of the greatest challenges when drilling directionally with an FC (fixed cutter) drill bit on a positive displacement motor (PDM).
Tool-face offset is proportional to the torque generated by the bit. FC bits, by nature, generate high levels of torque. If an external force acting on the bit causes an FC bit to over-engage, a large change in downhole torque is typically produced, which causes rotation of the drillstring and loss of tool-face orientation. It is therefore desirable for an FC bit to produce a torque response that does not vary greatly with changes in the external forces applied.
This paper examines the effect of varied components of an FC drill bit to determine the key design requirements to deliver a smooth torque response and improved directional performance. This includes evaluation of the results from a comprehensive series of laboratory tests to determine the effectiveness of a number of varied, removable torque controlling components (TCC). The goal was to establish a configuration that would provide predictable torque response to applied weight on bit (WOB), allowing cutting structures to be independently optimized for overall higher penetration rates.
A novel gauge geometry was engineered to reduce drag and deliver a smoother borehole. This would provide less torque when sliding and beneficial gauge pad interaction with the borehole when in rotating mode.
Field performance studies clearly demonstrate that matching TCC, an optimized cutting structure, and gauge geometry to a steerable assembly delivers smooth torque response and improved directional control. Benefits within rotary vertical applications are also demonstrated. Successful application has resulted in significant time and cost savings.
Implementation of a Shock and Vibration Mitigation Process: Achieving Real-Time Solutions and Savings
Authors: Akinniranye Goke , Megat Amanda , Elsweisy Hesham , Palacio Julio , Poedjono Benny , Goobie Roger 
Published: June 2009

Summary
Worldwide, the costs associated with the exploration and production of oil have increased almost exponentially in the past 5 years. This sharp rise in daily costs has also led to a new urgency from operators to find more-reliable and -efficient ways of doing business.
Shock and vibration (S&V) are the leading causes of failure for measurement-while-drilling (MWD) and rotary-steerable systems today. These failures have a major impact on operators and service companies, costing millions of dollars in repairs and hours of rig time.
To better understand downhole dynamics, a wide variety of service companies now offer lateral, axial, and transverse-shock measurements, along with downhole rev/min (RPM) readings. In the best case, these measurements offer a reactive method of drilling, and in the worst case, they provide no help in solving the problem or in preventing damage to the bottomhole assembly (BHA).
For S&V measurements to be effective, operators and service companies must work together to create a comprehensive process that includes each phase of drilling—planning, execution, and evaluation. An S&V standard combined with increased client awareness and education has allowed a new level of success to be achieved at the rigsite. Now, S&V issues at the rig can be identified in real time and monitored remotely from an operations-support center. This communication structure, coupled with prejob planning and modeling and the capture of post-run lessons learned, can be used to offer solutions when problems arise, thereby preventing damage to the BHA, reducing rig non-productive time (NPT), and improving the rate of penetration (ROP).
A Compendium of Directional Calculations Based on the Minimum-Curvature Method—Part 2: Extension to Steering and Landing Applications
Authors: Sawaryn S. J. , Tulceanu M. A. 
Published: June 2009

Summary
The point-to-target calculations contained in Part 1 of the compendium (Sawaryn and Thorogood 2005) were restricted to those cases in which the 3D target coordinates were stated explicitly. However, another class of problems exists where the target's structural position is determined indirectly from other constraints defining the arc's orientation. This new paper builds on the earlier work and contains complete details of twelve explicit algorithms, including the calculation of a target on the basis of the toolface at the start or end of an arc and for the landing of a well path parallel to a formation bedding plane.
These cases find practical application in computing trajectories of motor runs and in whipstock operations. The curvature of the trajectory landing on a bedding plane varies with direction and has a distinct minimum and maximum. These values may be used either to minimize the distance to the target or to limit the dogleg severity (DLS) to avoid drillpipe fatigue, a concern in short-radius drilling applications.
The algorithms add to the compendium and are useful extensions to the engineer's computational toolkit. The paper shows that the trajectories, computed using the minimum-curvature calculation, are contained within the geometric surfaces defined by a torus or cyclide. These geometries explain why the explicit solutions exist, opening up possibilities for obtaining solutions to the more-complex cases.
Experimental and Numerical Investigations of Borehole Ballooning in Rough Fractures
Authors: Ozdemirtas M. , Babadagli T. , Kuru E. 
Published: June 2009

Summary
Borehole ballooning/breathing is a combined mud-loss/-gain event observed during drilling operations in naturally fractured formations. Factors controlling this phenomenon must be well understood to correctly interpret its symptoms observed during drilling to avoid mixing ballooning with other formation flow incidents that might lead to unwarranted well-control procedures.
A mathematical model defining the ballooning process was developed and solved numerically using finite-difference approximation. It was shown that fracture roughness and fracture deformation play a significant role in the flow of drilling fluid in and out of a single fracture. In this study, the focus was mainly on the effect of fracture roughness (characterized by the fractal dimension of the fracture surface) and fracture aperture.
The main goal of this work was to compare the numerical-model results with laboratory-scale experimental observations. Therefore, experiments were performed to study the mud-loss and -gain events in artificially fractured rock samples. Cylinders of Berea sandstone, Indiana limestone, and granite were used for the experiments (1-in. diameter, 3-in. length). Two different fracture types were used to analyze the effect of fracture-surface roughness on the flow of drilling fluid in and out of the fracture. To create smooth fracture surfaces, cores were cut precisely into two equal pieces using a blade. Alternatively, axial load was applied on the cylindrical rock samples until a longitudinal fracture with a rough surface was generated.
The results of experimental observations and numerical-model study on the importance of fracture roughness were provided. Situations where the degree of roughness becomes critical were identified.