bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of delay estimation models for signalised intersections using field observations in Shanghai
Authors: Wang Zhongyu , Chen Shiyu , Yang Hang , Wu Bing , Wang Yinhai 
Published: December 2015

Vehicular control delay is important in evaluating the level of service and designing or adjusting the control schemes at signalised intersections. Although control delay may be obtained directly or indirectly nowadays for vehicles with global positioning system (GPS) or at locations with designated sensor types and configurations, such data are still not widely available. The analytical and empirical procedures for control delay estimation are still important, particularly in developing countries. However, very few studies explored the effectiveness of existing control delay estimation methods. This study intends to address this issue by comparing the delays estimated by four commonly adopted models using field data observed from three signalised intersections in Shanghai. Specifically, the study compares the delay estimates from deterministic queuing model, Webster model, highway capacity manual (HCM) 2000 model, and Shanghai adjusted model. The results indicate that HCM 2000 model and Shanghai adjusted model perform similarly and satisfactorily under various v /c ratios while deterministic queuing model has better performance when the v /c ratio is extremely high, but Webster model is mostly inadequate at coordinated signalised intersections. Meanwhile, signal progression, initial queue, proportion of vehicles arriving on green are found as main influential factors to the precision of models based on data analysis.
Nickel phlorin intermediate formed by proton-coupled electron transfer in hydrogen evolution mechanism
Authors: Solis Brian H. , Maher Andrew G. , Dogutan Dilek K. , Nocera Daniel G. , Hammes-Schiffer Sharon 
Published: December 2015

Significance
Global energy sustainability requires the development of effective energy conversion processes. In the hydrogen evolution reaction, electrons and protons are combined to generate molecular hydrogen, which stores energy in its chemical bond. Molecular electrocatalysts have been designed to facilitate this reaction by making it occur faster with lower energy input, often utilizing proton-coupled electron transfer (PCET), which couples the motions of electrons and protons to avoid high-energy intermediates. Examination of a nickel porphyrin electrocatalyst indicates that the active intermediate stores electrons in the C–H bond of the modified porphyrin generated by PCET, rather than in the traditional metal-hydride bond. The ability to store electrons in the ligand rather than in the metal has significant implications for the design of electrocatalysts.
Curtailing patient-specific IMRT QA procedures from 2D dose error distribution
Authors: Kurosu Keita , Sumida Iori , Mizuno Hirokazu , Otani Yuki , Oda Michio , Isohashi Fumiaki , Seo Yuji , Suzuki Osamu , Ogawa Kazuhiko 
Published: December 2015

AbstractA patient-specific quality assurance (QA) test is conducted to verify the accuracy of dose delivery. It generally consists of three verification processes: the absolute point dose difference, the planar dose differences at each gantry angle, and the planar dose differences by 3D composite irradiation. However, this imposes a substantial workload on medical physicists. The objective of this study was to determine whether our novel method that predicts the 3D delivered dose allows certain patient-specific IMRT QAs to be curtailed. The object was IMRT QA for the pelvic region with regard to point dose and composite planar dose differences. We compared measured doses, doses calculated in the treatment planning system, and doses predicted by in-house software. The 3D predicted dose was reconstructed from the per-field measurement by incorporating the relative dose error distribution into the original dose grid of each beam. All point dose differences between the measured and the calculated dose were within ±3%, whereas 93.3% of them between the predicted and the calculated dose were within ±3%. As for planar dose differences, the gamma passing rates between the calculated and the predicted dose were higher than those between the calculated and the measured dose. Comparison and statistical analysis revealed a correlation between the predicted and the measured dose with regard to both point dose and planar dose differences. We concluded that the prediction-based approach is an accurate substitute for the conventional measurement-based approach in IMRT QA for the pelvic region. Our novel approach will help medical physicists save time on IMRT QA.
Understanding the Leaky Pipeline: Perceived Barriers to Pursuing a Career in Medicine or Dentistry Among Underrepresented-in-Medicine Undergraduate Students
Authors: Freeman Brandi Kaye , Landry Alden , Trevino Robert , Grande David , Shea Judy A. 
Published: December 2015

Purpose
Representation of persons from diverse backgrounds remains a persistent challenge for medicine and dentistry workforces. Past research has focused on quantifying factors such as markers of educational achievement to explain the difficulty of increasing diversity within the professions. There has been less effort toward understanding the perspectives of undergraduate students on the threshold of applying to medical/dental school about distinct barriers to pursuing a medical or dental career and continuing through the training pipeline.

Method
In 2012 and 2013, the authors conducted a qualitative study of undergraduate students participating in the Tour for Diversity in Medicine, a program where minority physicians and dentists visit colleges with large fractions of minority students to encourage careers in the health professions. Focus groups were convened during the visits to examine perceived barriers to pursuing careers in medicine and dentistry and challenges identified through thematic content analysis.

Results
Eighty-two students participated in discussions at 11 colleges visited between September 2012 and February 2013. Students described challenges including inadequate institutional resources (e.g., sparse clinical opportunities), strained personal resources (e.g., conflict arising from familial pressure), inadequate guidance and mentoring to assist with key career decisions, and societal barriers. For participants, these challenges caused them to question the viability of persisting in the pipeline to a medical or dental career.

Conclusions
Solving the issue of diversity in medicine and dentistry is multifaceted, but elucidated challenges from the undergraduate student perspective offer targeted areas where intervention may help remedy barriers and decrease pipeline leakiness.
Preoperative Score to Predict Postoperative Mortality (POSPOM)
Authors: Le Manach Yannick , Collins Gary , Rodseth Reitze , Le Bihan-Benjamin Christine , Biccard Bruce , Riou Bruno , Devereaux P.J. , Landais Paul 
Published: December 2015

Abstract

Background
An accurate risk score able to predict in-hospital mortality in patients undergoing surgery may improve both risk communication and clinical decision making. The aim of the study was to develop and validate a surgical risk score based solely on preoperative information, for predicting in-hospital mortality.

Methods
From January 1, 2010, to December 31, 2010, data related to all surgeries requiring anesthesia were collected from all centers (single hospital or hospitals group) in France performing more than 500 operations in the year on patients aged 18 yr or older (n = 5,507,834). International Statistical Classification of Diseases, 10th revision codes were used to summarize the medical history of patients. From these data, the authors developed a risk score by examining 29 preoperative factors (age, comorbidities, and surgery type) in 2,717,902 patients, and then validated the risk score in a separate cohort of 2,789,932 patients.

Results
In the derivation cohort, there were 12,786 in-hospital deaths (0.47%; 95% CI, 0.46 to 0.48%), whereas in the validation cohort there were 14,933 in-hospital deaths (0.54%; 95% CI, 0.53 to 0.55%). Seventeen predictors were identified and included in the PreOperative Score to predict PostOperative Mortality (POSPOM). POSPOM showed good calibration and excellent discrimination for in-hospital mortality, with a c-statistic of 0.944 (95% CI, 0.943 to 0.945) in the development cohort and 0.929 (95% CI, 0.928 to 0.931) in the validation cohort.

Conclusion
The authors have developed and validated POSPOM, a simple risk score for the prediction of in-hospital mortality in surgical patients.
Epigenetic Manipulation of Brain-derived Neurotrophic Factor Improves Memory Deficiency Induced by Neonatal Anesthesia in Rats
Authors: Wu Jiang , Bie Bihua , Naguib Mohamed 
Published: December 2015

AbstractAbstract
The authors found a substantial reduction of hippocampal brain-derived neurotrophic factor resulting from the transcriptional factors–mediated epigenetic modification in the promoter region of Bdnf exon IV in rats exposed postnatally to anesthetic drugs. This brain-derived neurotrophic factor reduction led to the insufficient drive for the synthesis of synaptic proteins, thus contributing to the hippocampal synaptic and cognitive dysfunction induced by neonatal anesthesia. These effects were mitigated by the exposure to an enriched environment.

Background
Although neonatal exposure to anesthetic drugs is associated with memory deficiency in rodent models and possibly in pediatric patients, the underlying mechanisms remain elusive. The authors tested their hypothesis that exposure of the developing brain to anesthesia triggers epigenetic modification, involving the enhanced interaction among transcription factors (histone deacetylase 2, methyl-cytosine-phosphate-guanine–binding protein 2, and DNA methyltransferase 1) in Bdnf promoter region(s) that inhibit brain-derived neurotrophic factor (BDNF) expression, resulting in insufficient drive for local translation of synaptic mRNAs. The authors further hypothesized that noninvasive environmental enrichment (EE) will attenuate anesthesia-induced epigenetic inhibition of BDNF signaling and memory loss in rodent models.

Methods
Seven days after birth (P7), neonatal rats were randomly assigned to receive either isoflurane anesthesia for 6 h or sham anesthesia. On P21, pups were weaned, and animals were randomly assigned to EE or a standard cage environment (no EE). Behavioral, molecular, and electrophysiological studies were performed on rats on P65.

Results
The authors found a substantial reduction of hippocampal BDNF (n = 6 to 7) resulting from the transcriptional factors–mediated epigenetic modification in the promoter region of Bdnf exon IV in rats exposed postnatally to anesthetic drugs. This BDNF reduction led to the insufficient drive for the synthesis of synaptic proteins (n = 6 to 8), thus contributing to the hippocampal synaptic (n = 8 to 11) and cognitive dysfunction (n = 10) induced by neonatal anesthesia. These effects were mitigated by the exposure to an enriched environment.

Conclusions
The findings of this study elucidated the epigenetic mechanism underlying memory deficiency induced by neonatal anesthesia and propose EE as a potential therapeutic approach.
IV and Perineural Dexmedetomidine Similarly Prolong the Duration of Analgesia after Interscalene Brachial Plexus Block
Authors: Abdallah Faraj W. , Dwyer Tim , Chan Vincent W. S. , Niazi Ahtsham U. , Ogilvie-Harris Darrell J. , Oldfield Stephanie , Patel Rajesh , Oh Justin , Brull Richard 
Published: December 2015

AbstractAbstract
In 99 patients receiving interscalene block with 15 ml ropivacaine, 0.5%, with 0.5 μg/kg dexmedetomidine prolonged the blockade and reduced the 24-h opioid use compared with placebo control, and these effects were similar whether dexmedetomidine was administered intravenously or perineurally.

Background
Perineural and IV dexmedetomidine have each been suggested to prolong the duration of analgesia when administered in conjunction with peripheral nerve blocks. In the first randomized, triple-masked, placebo-controlled trial to date, the authors aimed to define and compare the efficacy of perineural and IV dexmedetomidine in prolonging the analgesic duration of single-injection interscalene brachial plexus block (ISB) for outpatient shoulder surgery.

Methods
Ninety-nine patients were randomized to receive ISB using 15 ml ropivacaine, 0.5%, with 0.5 μg/kg dexmedetomidine administered perineurally (DexP group), intravenously (DexIV group), or none (control group). The authors sequentially tested the joint hypothesis that dexmedetomidine prolongs the duration of analgesia and reduces the 24-h cumulative postoperative morphine consumption. Motor blockade, pain severity, hemodynamic variations, opioid-related side effects, postoperative neurologic symptoms, and patient satisfaction were also evaluated.

Results
Ninety-nine patients were analyzed. The duration of analgesia was 10.9 h (10.0 to 11.8 h) and 9.8 h (9.0 to 10.6 h) for the DexP and DexIV groups, respectively, compared with 6.7 h (5.6 to 7.8) for the control group (P < 0.001). Dexmedetomidine also reduced the 24-h cumulative morphine consumption to 63.9 mg (58.8 to 69.0 mg) and 66.2 mg (60.6 to 71.8 mg) for the DexP and DexIV groups, respectively, compared with 81.9 mg (75.0 to 88.9 mg) for the control group (P < 0.001). DexIV was noninferior to DexP for these outcomes. Both dexmedetomidine routes reduced the pain and opioid consumption up to 8 h postoperatively and did not prolong the duration of motor blockade.

Conclusion
Both perineural and IV dexmedetomidine can effectively prolong the ISB analgesic duration and reduce the opioid consumption without prolonging motor blockade.
PGE1 Attenuates IL-1β-induced NGF Expression in Human Intervertebral Disc Cells
Authors: Murata Kazuma , Sawaji Yasunobu , Alimasi Wuqikun , Suzuki Hidekazu , Endo Kenji , Tanaka Hidetoshi , Yorifuji Makiko , Kosaka Taiichi , Shishido Takaaki , Yamamoto Kengo 
Published: December 2015

Study Design.

In vitro study using isolated human intervertebral disc (IVD) cells.

Objective.
To investigate the effects of prostaglandin (PG)E1 and its orally available derivative limaprost on the regulation of nerve growth factor (NGF) expression and to compare their actions with other prostanoids using interleukin (IL)-1-stimulated human IVD cells.

Summary of Background Data.
We previously reported that a selective COX-2 inhibitor enhanced, whereas PGE2 suppressed the induction of NGF by IL-1 in human IVD cells, and proposed that PGE2 can suppress NGF expression by a negative feedback mechanism.

Methods.
Isolated human IVD cells were stimulated with IL-1 in the presence or absence of increasing concentrations of PGE2, PGE1, limaprost, PGI2, PGD2, or PGF2α (10–10,000 nM). For some experiments, an E-series prostanoid receptor (EP)4 antagonist (L-161,982) was added prior to the stimulation. NGF expression was determined by real-time polymerase chain reaction and its protein level was quantified by enzyme-linked immunosorbent assay.

Results.
PGE2, PGE1, and limaprost inhibited the IL-1-mediated induction of NGF in a concentration-dependent manner, with IC50 values of 9.9, 10.6, and 70.9 nM, respectively. PGI2 also suppressed NGF expression but to a much less extent. PGD2, on the other hand, significantly enhanced NGF expression, whereas PGF2α had no effect. Protein expression levels of NGF mirrored its mRNA levels. The suppression of NGF expression by PGE2 and PGE1 was partly reversed by L-161,982.

Conclusion.
PGE1 and limaprost exhibited a novel pharmacological action that suppresses NGF expression in human IVD cells, and other prostanoids differentially regulated NGF expression. Limaprost has been used to treat patients with lumbar spinal stenosis in Japan and was proved to be effective in relieving symptoms. Our in vitro results may explain, in part, the mechanism of action of limaprost for low back pain.

Level of Evidence: N/A
Changes in Whole-Body Oxygen Consumption and Skeletal Muscle Mitochondria During Linezolid-Induced Lactic Acidosis
Authors: Protti Alessandro , Ronchi Dario , Bassi Gabriele , Fortunato Francesco , Bordoni Andreina , Rizzuti Tommaso , Fumagalli Roberto 
Published: December 2015

Objective:
To better clarify the pathogenesis of linezolid-induced lactic acidosis.

Design:
Case report.

Setting:
ICU.

Patient:
A 64-year-old man who died with linezolid-induced lactic acidosis.

Interventions:
Skeletal muscle was sampled at autopsy to study mitochondrial function.

Measurements and Main Results:
Lactic acidosis developed during continuous infusion of linezolid while oxygen consumption and oxygen extraction were diminishing from 172 to 52 mL/min/m2 and from 0.27 to 0.10, respectively. Activities of skeletal muscle respiratory chain complexes I, III, and IV, encoded by nuclear and mitochondrial DNA, were abnormally low, whereas activity of complex II, entirely encoded by nuclear DNA, was not. Protein studies confirmed stoichiometric imbalance between mitochondrial (cytochrome c oxidase subunits 1 and 2) and nuclear (succinate dehydrogenase A) DNA–encoded respiratory chain subunits. These findings were not explained by defects in mitochondrial DNA or transcription. There were no compensatory mitochondrial biogenesis (no induction of nuclear respiratory factor 1 and mitochondrial transcript factor A) or adaptive unfolded protein response (reduced concentration of heat shock proteins 60 and 70).

Conclusions:
Linezolid-induced lactic acidosis is associated with diminished global oxygen consumption and extraction. These changes reflect selective inhibition of mitochondrial protein synthesis (probably translation) with secondary mitonuclear imbalance. One novel aspect of linezolid toxicity that needs to be confirmed is blunting of reactive mitochondrial biogenesis and unfolded protein response.
PPX and Concurrent Radiation for Newly Diagnosed Glioblastoma Without MGMT Methylation
Authors: Elinzano Heinrich , Glantz Michael , Mrugala Maciej , Kesari Santosh , Piccioni David E. , Kim Lyndon , Pan Edward , Yunus Shakeeb , Coyle Thomas , Timothy Kinsella , Evans Devon , Mantripragada Kalyan , Boxerman Jerrold , DiPetrillo Thomas , Donahue John E. , Hebda Nicholas , Mitchell Kristen M. , Rosati Kayla L. , Safran Howard 
Published: December 2015

Purpose:
Efficacy signals but substantial myelosuppression were demonstrated in a single arm phase II study of paclitaxel poliglumex (PPX) in combination with temozolomide (TMZ) and radiation therapy (RT) for first-line treatment of glioblastoma. The objective of this randomized phase II trial was to assess the efficacy and safety of single-agent PPX with RT (PPX/RT) versus TMZ with RT (TMZ/RT) for glioblastoma without O6-methylguanine-DNA methyltransferase (MGMT) methylation.

Materials and Methods:
Patients with glioblastoma with unmethylated MGMT without prior chemotherapy or RT were eligible. Patients were randomly assigned 2:1 to PPX, 50 mg/m2/wk for 6 weeks, or standard TMZ, with concurrent 60.0 Gy RT. One month after completion of chemoradiation all patients received standard maintenance TMZ. The primary endpoint was progression-free survival (PFS).

Results:
Of the 164 patients enrolled, 86 were MGMT unmethylated. Of these, 63 patients were randomized (42 to PPX/RT and 21 to TMZ/RT). Fifty-nine patients could be analyzed. The median PFS was 9 months in the PPX/RT group and 9.5 months in the TMZ/RT group (hazard ratio in the PPX/RT group, 1.10; 95% confidence interval, 0.79-2.08; P=0.75). Median overall survival was 16 versus 14.8 months for PPX/RT and TMZ/RT groups, respectively (hazard ratio, 1.44; 95% confidence interval, 0.75-2.77; P=0.27). In the PPX and TMZ groups 44% versus 22% of patients, respectively, experienced one or more grade 3 or higher toxicities during chemoradiation.

Conclusions:
PPX/RT did not improve PFS or overall survival. This study provides an effective trial design for screening RT sensitizers in glioblastoma.
Effect of Head Tilt and Ocular Compensatory Mechanisms on Retinal Nerve Fiber Layer Measurements by Cirrus Spectral Domain and Spectralis Optical Coherence Tomography in Normal Subjects
Authors: Bin Ismail Muhammad A. , Hui Li Lilian Koh , Yap Sae Cheong , Yip Leonard W. 
Published: December 2015

Purpose:
To determine the effect of head tilt and ocular compensatory mechanisms on retinal nerve fiber layer (RNFL) thickness measurements using the Cirrus and Spectralis spectral-domain optical coherence tomography (OCT) in healthy eyes. Our secondary objective was to assess the visual influence on ocular compensatory mechanisms during head tilt.

Materials and Methods:
This is a prospective, observational study. A single randomly selected eye was scanned undilated in 3 positions (baseline, right, and left tilt) using both machines. In addition, patching was also done for the contralateral eye during head tilt and RNFL measurements repeated. The paired t test was used to analyze effect on RNFL thickness. One-way repeated-measures analysis of variance was used to compare differences in RNFL measurements.

Results:
In Cirrus OCT RNFL analysis, ipsilateral head tilt resulted in superior thinning and temporal thickening, whereas contralateral head tilt resulted in inferior thinning, nasal thickening, as well as temporal thickening (all P<0.05). Head tilt did not cause any significant change in RNFL thickness with Spectralis OCT (P>0.05). Patching the contralateral eye also did not alter Cirrus RNFL measurement errors due to head tilt.

Conclusions:
Head tilt can affect the measurement of the RNFL thickness in Cirrus OCT, and ocular compensatory mechanisms were not sufficient to prevent this. In contrast, Spectralis OCT RNFL thickness measurements were not affected by head tilt. Patching the contralateral eye during head tilt in Cirrus OCT also did not affect RNFL variability. The visual influence on ocular compensatory mechanisms during head tilt appears insignificant.
Spray Dried, Pasteurised Bovine Colostrum Protects Against Gut Dysfunction and Inflammation in Preterm Pigs
Authors: St⊘y Ann Cathrine F. , Sangild Per T. , Skovgaard Kerstin , Thymann Thomas , Bjerre Mette , Chatterton Dereck E.W. , Purup Stig , Boye Mette , Heegaard Peter M.H. 
Published: December 2015

ABSTRACTObjective:Feeding bovine colostrum (BC) improves gut maturation and function and protects against necrotizing enterocolitis, relative to formula in newborn preterm pigs. Before BC can be used for preterm infants, it is important to test if the milk processing, required to reduce bacterial load and increase shelf life, may affect bioactivity and efficacy of a BC product.Methods:We investigated if spray dried, pasteurised BC had protective effects on gut function in preterm pigs, relative to formula. After a 2‐day total parenteral nutrition period, preterm pigs were fed formula for a few hours (to induce a proinflammatory state) followed by 2 days of formula (FORM, n = 14), BC (colostrum [COLOS], n = 14), spray‐dried BC (POW, n = 8), or pasteurised, spray‐dried BC (POWPAS, n = 9).Results:Spray drying and pasteurisation of BC decreased the concentration of transforming growth factor‐β1, ‐β2 and increased protein aggregation. All of the 3 BC groups had reduced necrotizing enterocolitis severity, small intestinal levels of IL‐1β, ‐8, and colonic lactic acid levels, and increased intestinal villus height, hexose absorption, and digestive enzyme activities, relative to the FORM group (all P < 0.05). All of the 3 BC diets stimulated epithelial cell migration in a wound‐healing model with IEC‐6 cells.Conclusions:Spray drying and pasteurisation affect BC proteins, but do not reduce the trophic and anti‐inflammatory effects of BC on the immature intestine. It remains to be studied if BC products will benefit preterm infants just after birth when human milk is often not available.