bluuebunny/crossref_metadata_2025_split huggingface dataset:
Understanding the Role of the Electron‐Transport Layer in Highly Efficient Planar Perovskite Solar Cells
Authors: Liu Jiang , Wang Gang , Luo Kun , He Xulin , Ye Qinyan , Liao Cheng , Mei Jun 
Published: January 2017

AbstractSolar cells based on perovskite absorbers are rapidly emerging as attractive candidates for photovoltaics development. Understanding the role of the electron‐transport layer (ETL) is very important to obtain highly efficient perovskite solar cells. Herein, the effect of the ETL on device performance in planar perovskite solar cells is investigated in detail, and the band bending in different situations is discussed. The ET barrier is shown to be responsible for the poor fill factor (FF) of J–V curves. Introduction of a thin bathocuproine interlayer increases the interface inversion and results in an increase of FF from 56 to 76 %. Some experimental and theoretical results verify these conclusions. Furthermore, this study can provide an interface‐engineering strategy to improve device performance.
An In‐Depth Structural Study of the Carbon Dioxide Adsorption Process in the Porous Metal–Organic Frameworks CPO‐27‐M
Authors: Pato‐Doldán Breogán , Rosnes Mali H. , Dietzel Pascal D. C. 
Published: January 2017

AbstractThe CO2 adsorption process in the family of porous metal–organic framework materials CPO‐27‐M (M=Mg, Mn, Co, Ni, Cu, and Zn) was studied by variable‐temperature powder synchrotron X‐ray diffraction under isobaric conditions. The Rietveld analysis of the data provided a time‐lapse view of the adsorption process on CPO‐27‐M. The results confirm the temperature‐dependent order of occupation of the three adsorption sites in the pores of the CPO‐27‐M materials. In CPO‐27‐M (M=Mg, Mn, Co, Ni, and Zn), the adsorption sites are occupied in sequential order, primarily because of the high affinity of CO2 for the open metal sites. CPO‐27‐Cu deviates from this stepwise mechanism, and the adsorption sites at the metal cation and the second site are occupied in parallel. The temperature dependence of the site occupancy of the individual CO2 adsorption sites derived from the diffraction data is reflected in the shape of the volumetric sorption isotherms. The fast kinetics and high reversibility observed in these experiments support the suitability of these materials for use in temperature‐ or pressure‐swing processes for carbon capture.
Trait‐based approaches to analyze links between the drivers of change and ecosystem services: Synthesizing existing evidence and future challenges
Authors: Hevia Violeta , Martín‐López Berta , Palomo Sara , García‐Llorente Marina , de Bello Francesco , González José A. 
Published: January 2017

AbstractUnderstanding the responses of biodiversity to drivers of change and the effects of biodiversity on ecosystem properties and ecosystem services is a key challenge in the context of global environmental change. We performed a systematic review and meta‐analysis of the scientific literature linking direct drivers of change and ecosystem services via functional traits of three taxonomic groups (vegetation, invertebrates, and vertebrates) to: (1) uncover trends and research biases in this field; and (2) synthesize existing empirical evidence. Our results show the existence of important biases in published studies related to ecosystem types, taxonomic groups, direct drivers of change, ecosystem services, geographical range, and the spatial scale of analysis. We found multiple evidence of links between drivers and services mediated by functional traits, particularly between land‐use changes and regulating services in vegetation and invertebrates. Seventy‐five functional traits were recorded in our sample. However, few of these functional traits were repeatedly found to be associated with both the species responses to direct drivers of change (response traits) and the species effects on the provision of ecosystem services (effect traits). Our results highlight the existence of potential “key functional traits,” understood as those that have the capacity to influence the provision of multiple ecosystem services, while responding to specific drivers of change, across a variety of systems and organisms. Identifying “key functional traits” would help to develop robust indicator systems to monitor changes in biodiversity and their effects on ecosystem functioning and ecosystem services supply.
Identifying attributes of CO2 leakage zones in shallow aquifers using a parametric level set method
Authors: Sun Alexander Y. , Wheeler Mary F. , Islam Akand 
Published: January 2017

AbstractLeakage through abandoned wells and geologic faults poses the greatest risk to CO2 storage permanence. For shallow aquifers, secondary CO2 plumes emanating from the leak zones may go undetected for a sustained period of time and has the greatest potential to cause large‐scale and long‐term environmental impacts. Identification of the attributes of leak zones, including their shape, location, and strength, is required for environmental risk assessment. This study applies a parametric level set (PaLS) method to characterize leak zones. Level set methods are appealing for tracking topological changes and recovering unknown shapes of objects. However, level set evolution using the conventional level set methods is computationally challenging. In PaLS, the level set function is approximated by using a weighted sum of basis functions and the level set evolution problem is replaced by an optimization problem. The efficacy of PaLS is demonstrated by reconstructing attributes of a CO2 leak zone in a carbonate aquifer. Our results show that PaLS is a robust source identification method that can recover the approximate leak zone locations in the presence of measurement errors, model parameter uncertainty, and inaccurate guesses of source flux strengths. Accurate delineation of source geometry is achievable when a relatively dense observation network is used. The PaLS‐based, source recovery framework introduced in this work is generic and can be adapted for any reactive transport model by simply switching the pre‐ and post‐processing routines. © 2017 Society of Chemical Industry and John Wiley & Sons, Ltd.
Treatment of Choriocarcinoma in Singapore
Authors: Chew S. C. , Ratnam S. S. 
Published: January 2017

ABSTRACTOver 750 cases of trophoblastic disease have been documented in this Unit during the last 16 years. Of these, the majority were benign hydatidiform moles. but 106 patients had trophoblastic disease of a malignant nature. Those that were destructive or “metastasizing moles” or frank choriocarcinoma were sub‐divided on histology into “villous” or “avillous” categories respectively. Where there was a persistence of HCG activity beyond the expected time after evacuation, or where there were secondaries on which no histology was available, they were classed as “clinical choriocarcinoma”. The response of each of the tumours according to the above classification is presented in this paper and the difference in prognosis with the advent of drugs like methotrexate and others is discussed.
The Value of Bed Rest in Twin Pregnancies
Authors: Komáromy Béla , Lampé László 
Published: January 2017

ABSTRACTThe effect of bed rest on the duration of pregnancy, the birth weight of newborns, the frequency of premature birth, and perinatal mortality was examined in 491 twin pregnancies. Cases were divided into two groups—women hospitalized from the 24th–26th week of pregnancy until delivery (rested group, 242 patients) and outpatients (unrested group, 249 patients). The premature birth rate was considerably less for patients in the rested group: in this group 41.0% of the newborns were delivered earlier than the 38th week and 42.9% of them weighed less than 2 500 g, whereas in the unrested group 75.0% were delivered earlier than the 38th week and 77.2% weighed less than 2 500 g. In addition, the perinatal mortality rates observed in the two groups were significantly different. Based on these findings, we conclude that the high premature birth rates and subsequent high perinatal mortality may be considerably reduced if twin pregnancies are diagnosed early and patients are hospitalized from the 26th or 27th week until delivery.
Serum Cholesterol and Hemoglobin Levels and Calorie Requirements in Pregnant Nigerian Women
Authors: Ojo M. O. , Sogbanmu M. O. 
Published: January 2017

ABSTRACTA study conducted on 50 healthy senior staff wives (socioeconomic group 1) and 63 healthy junior staff wives (socioeconomic group 2) attending the antenatal clinic at the University of Ife Health Center showed marked differences in the level of serum cholesterol and hemoglobin between the two groups. It was also found that women in group 2 took 6.8% of their total calorie requirements as fat and group 1 women took 12.0% of their total calorie requirements as fat.
The Endodermal Sinus Tumor: Special Features
Authors: Azoury Ramez S. , Nasr Munir F. , Muawwad Roland F. 
Published: January 2017

ABSTRACTEight cases of endodermal sinus tumor, two extragonadal and six gonadal, seen at the American University of Beirut are reviewed. Three of them present special clinical and pathologic features that further substantiate the extraembryonic origin of this teratoid tumor and its association with dysgenetic gonads. We consider the two histologic types, endodermal sinus pattern and polyvesicular vitelline architecture, to be part of the same tumor. The prognosis in this series was unfavorable.
Birth Weight, Gestational Age and Other Indices of Fetal Maturity
Authors: Pachauri Saroj , Marwah S. M. 
Published: January 2017

ABSTRACTA number of indices for evaluating the maturity of the newborn were studied. Indices of anthropometric, anatomic, reflex and physiologic development were examined to evaluate their association with birth weight and gestational age; the validity of these diagnostic indices is discussed. Studies are recommended to establish a maturity score to identify high‐risk infants at birth.
Malarial Immunity in Pregnant Nigerian Women and Their Newborn
Authors: Ibeziako P. A. , Okerengwo A. A. , Williams A. I. O. 
Published: January 2017

ABSTRACTThe levels of malarial fluorescent antibody titers (MFAT) were estimated throughout pregnancy and at delivery in 20 urban Nigerian primigravidas who received malarial chemoprophylaxis. There was a statistically significant (p < 0.001) fall in the MFAT levels as pregnancy progressed. The mean logarithmic MFAT levels were 2.8664 ± 0.3326 and 2.2794 ± 0.1656 in the first and last trimesters of pregnancy, respectively. The MFAT level in the newborn was positively correlated to the maternal MFAT level at delivery (r = 0.9468; p < 0.001). If malarial prophylactics are used for a prolonged period, the maternal MFAT level will fall, leaving newborns with lowered immunity to malaria.
Panoramic ultrasound: a novel and valid tool for monitoring change in muscle mass
Authors: Scott Jessica M. , Martin David S. , Ploutz‐Snyder Robert , Matz Timothy , Caine Timothy , Downs Meghan , Hackney Kyle , Buxton Roxanne , Ryder Jeffrey W. , Ploutz‐Snyder Lori 
Published: January 2017

AbstractBackgroundThe strong link between reduced muscle mass and morbidity and mortality highlights the urgent need for simple techniques that can monitor change in skeletal muscle cross‐sectional area (CSA). Our objective was to examine the validity of panoramic ultrasound to detect change in quadriceps and gastrocnemius size in comparison with magnetic resonance imaging (MRI) in subjects randomized to 70 days of bed rest (BR) with or without exercise.MethodsPanoramic ultrasound and MRI images of the quadriceps and gastrocnemius muscles were acquired on the right leg of 27 subjects (26 male, 1 female; age: 34.6 ± 7.8 years; body mass: 77.5 ± 10.0 kg; body mass index: 24.2 ± 2.8 kg/m2; height: 179.1 ± 6.9 cm) before (BR‐6), during (BR3, 7, 11, 15, 22, 29, 36, 53, 69), and after (BR+3, +6, +10) BR. Validity of panoramic ultrasound to detect change in muscle CSA was assessed by Bland–Altman plots, Lin's concordance correlation coefficient (CCC), sensitivity, specificity, positive predictive value, and negative predictive value.ResultsSix hundred ninety‐eight panoramic ultrasound CSA and 698 MRI CSA measurements were assessed. Concordance between ultrasound and MRI was excellent in the quadriceps (CCC: 0.78; P < 0.0001), whereas there was poor concordance in the gastrocnemius (CCC: 0.37; P < 0.0006). Compared with MRI, panoramic ultrasound demonstrated high accuracy in detecting quadriceps atrophy and hypertrophy (sensitivity: 73.7%; specificity: 74.2%) and gastrocnemius atrophy (sensitivity: 83.1%) and low accuracy in detecting gastrocnemius hypertrophy (specificity: 33.0%).ConclusionsPanoramic ultrasound imaging is a valid tool for monitoring quadriceps muscle atrophy and hypertrophy and for detecting gastrocnemius atrophy.
Normal fluoroscopic appearance status post‐successful endoscopic Zenker diverticulotomy
Authors: Venkatesan Naren N. , Evangelista Lisa M. , Kuhn Maggie A. , Belafsky Peter C. 
Published: January 2017

ObjectiveEndoscopic Zenker diverticulotomy (EZD) is a primary treatment for Zenker diverticulum (ZD). During EZD, the diverticulum is not excised, and interpretation of postoperative videofluoroscopic swallow study (VFSS) is challenging. The purpose of this investigation was to describe normal VFSS findings status post‐successful EZD.MethodsThe charts of all patients with ZD treated at our center between October 01, 2011, and May 30, 2014, were abstracted. Outcome measures included recidivistic diverticulum size, Eating Assessment Tool‐10 (EAT‐10), penetration aspiration scale, pharyngeal constriction ratio (PCR), and pharyngoesophageal segment (PES) opening.ResultsTwenty patients met inclusion criteria. The mean age was 70.5 (± 13) years. Seventy percent of the patients were male. Mean EAT‐10 decreased 72.1% from 17.9 (± 8.2) to 5 (± 6.9) (P < 0.0001), and diverticulum size decreased 50.9% from 1.96 cm (± 0.68) to 0.96 cm (± 0.57) (P < 0.001). The PCR improved 33.6% from 0.17 (± 0.13) to 0.11 (± 0.11) (P < 0.001). Mean PES opening increased 61.6% from 0.53 cm (± 0.3544) to 0.86 cm (± 0.29) in lateral view and increased 40.0% from 1.00 cm (± 0.54) to 1.39 cm (± 0.46) in anteroposterior view (P < 0.001).ConclusionVFSS following successful EZD demonstrates an approximate 50% reduction in diverticulum size and significant improvement in PCR and PES opening. These data provide a framework for the expected fluoroscopic outcomes of successful diverticulotomy.Level of Evidence4. Laryngoscope, 127:1762–1766, 2017
Evidence‐based design for discoverability: A case study
Authors: Fallas Andrea , Tatham Suzanne 
Published: January 2017

Key points

Lean methods can give rich insights: Even a few, short sessions with a handful of users can generate useful inputs for a user‐centric design process.
Design for beginners: An interface that supports novices will also support experts.
Keep it simple: Focus on functionality that supports core search and discovery tasks.
Popular or high‐value features should have prime position and rarely used or low‐value features should be hidden or removed.
Visual cues are important for usability, as is balancing the visual space.
Spoof plasmon hybridization
Authors: Zhang Jingjing , Liao Zhen , Luo Yu , Shen Xiaopeng , Maier Stefan A. , Cui Tie Jun 
Published: January 2017

AbstractPlasmon hybridization between closely spaced nanoparticles yields new hybrid modes not found in individual constituents, allowing for the engineering of resonance properties as well as field enhancement capabilities of metallic nanostructure. Experimental verifications of plasmon hybridization have been thus far mostly limited to optical frequencies, as metals cannot support surface plasmons at longer wavelengths. Here, we introduce the concept of ‘spoof plasmon hybridization’ in highly conductive metal structures and investigate experimentally the interaction of localized surface plasmon resonances (LSPR) in adjacent metal disks corrugated with subwavelength spiral patterns. We show that the hybridization results in the splitting of spoof plasmon modes into bonding and antibonding resonances analogous to the molecular orbital rule and plasmonic hybridization in optical spectrum. These hybrid modes can be manipulated to produce enormous field enhancement (>5000) by tuning the separation between disks or alternatively, the disk size, which effectively changes the relative gap size. The impact of the radiation loss is considered to find out the optimum disk size that maximizes field enhancement capabilities. Our investigation not only extends the range of applicability of the hybridization model, but also provides insightful guidance to exporting the exciting applications associated with plasmon hybridization to lower spectral range.
image
Moment representations of the exceptional X1‐Laguerre orthogonal polynomials
Authors: Liaw Constanze , Osborn John 
Published: January 2017

Exceptional orthogonal Laguerre polynomials can be viewed as an extension of the classical Laguerre polynomials per excluding polynomials of certain order(s) from being eigenfunctions for the corresponding exceptional differential operator. We are interested in the (so‐called) Type I X1‐Laguerre polynomial sequence , and , where the constant polynomial is omitted.We derive two representations for the polynomials in terms of moments by using determinants. The first representation in terms of the canonical moments is rather cumbersome. We introduce adjusted moments and find a second, more elegant formula. We deduce a recursion formula for the moments and the adjusted ones. The adjusted moments are also expressed via a generating function. We observe a certain detachedness of the first two moments from the others.
Observed changes in temperature extremes for the Beijing–Tianjin–Hebei region of China
Authors: Zhang Yao , Huang Guohe , Wang Xiuquan , Liu Zhengping 
Published: January 2017

ABSTRACTAs one of the most significant threats facing the world, climate change has already been manifested everywhere in the form of frequent extreme climate events (e.g. heat waves, floods, droughts and wildfires) and has caused serious impacts on all aspects of the living environment. Due to the regional variability of global climate change, understanding the ongoing climatic changes at a local scale is very important for decision makers and resource managers to develop appropriate mitigation and adaptation strategies against the changing climate. In this study, recent changes in extreme temperature indices (including frost days, summer days, icy days, tropical nights, growing season length, cool nights and warm nights, cool days and warm days, and daily temperature range) over the Beijing–Tianjin–Hebei (BTH) region of China were investigated in the context of global warming. The results indicate that the historical trends of these extreme temperature indices are statistically significant in Huailai, Beijing, Leting and Shijiazhuang while no significant trends are reported in Chengde, Tianjin and Cangzhou−Potou. By comparing results between coastal and inland stations, it is found that the changes in temperature extremes in inland stations are less significant than the changes in coastal stations. The results also suggest that the indices based on minimum temperature show decreasing trends while those for maximum temperature present increasing trends. Furthermore, mutation tests were performed for all indices in order to understand when the changes were initiated. An apparent mutation point (mostly in the 1980s) is detected for most of the analysed temperature indices. This may be caused by the wide implementation of the reform and opening policy in the early 1980s to boost economic development in the BTH region.
Quantification of 1H–MRS signals based on sparse metabolite profiles in the time‐frequency domain
Authors: Parto Dezfouli Mohammad Ali , Parto Dezfouli Mohsen , Ahmadian Alireza , Frangi Alejandro F. , Esmaeili Rad Melika , Saligheh Rad Hamidreza 
Published: January 2017

MRS is an analytical approach used for both quantitative and qualitative analysis of human body metabolites. The accurate and robust quantification capability of proton MRS (1H–MRS) enables the accurate estimation of living tissue metabolite concentrations. However, such methods can be efficiently employed for quantification of metabolite concentrations only if the overlapping nature of metabolites, existing static field inhomogeneity and low signal‐to‐noise ratio (SNR) are taken into consideration.Representation of 1H–MRS signals in the time‐frequency domain enables us to handle the baseline and noise better. This is possible because the MRS signal of each metabolite is sparsely represented, with only a few peaks, in the frequency domain, but still along with specific time‐domain features such as distinct decay constant associated with T2 relaxation rate. The baseline, however, has a smooth behavior in the frequency domain.In this study, we proposed a quantification method using continuous wavelet transformation of 1H–MRS signals in combination with sparse representation of features in the time‐frequency domain. Estimation of the sparse representations of MR spectra is performed according to the dictionaries constructed from metabolite profiles. Results on simulated and phantom data show that the proposed method is able to quantify the concentration of metabolites in 1H–MRS signals with high accuracy and robustness. This is achieved for both low SNR (5 dB) and low signal‐to‐baseline ratio (−5 dB) regimes.
Cerebral hemodynamics and pseudo‐continuous arterial spin labeling considerations in adults with sickle cell anemia
Authors: Juttukonda Meher R. , Jordan Lori C. , Gindville Melissa C. , Davis Larry T. , Watchmaker Jennifer M. , Pruthi Sumit , Donahue Manus J. 
Published: January 2017

Sickle cell anemia (SCA) is a genetic disorder resulting in reduced oxygen carrying capacity and elevated stroke risk. Pseudo‐continuous arterial spin labeling (pCASL) measures of cerebral blood flow (CBF) may have relevance for stroke risk assessment; however, the effects of elevated flow velocity and reduced bolus arrival time (BAT) on CBF quantification in SCA patients have not been thoroughly characterized, and pCASL model parameters used in healthy adults are often applied to patients with SCA. Here, cervical arterial flow velocities and pCASL labeling efficiencies were computed in adults with SCA (n = 19) and age‐ and race‐matched controls without sickle trait (n = 7) using pCASL in sequence with phase contrast MR angiography (MRA). Controls (n = 7) and a subgroup of patients (n = 8) also underwent multi‐post‐labeling‐delay pCASL for BAT assessment. Mean flow velocities were elevated in SCA adults (velocity = 28.3 ± 4.1 cm/s) compared with controls (velocity = 24.5 ± 3.8 cm/s), and mean pCASL labeling efficiency (α) was reduced in SCA adults (α = 0.72) relative to controls (α = 0.91). In patients, mean whole‐brain CBF from phase contrast MRA was 91.8 ± 18.1 ml/100 g/min, while mean pCASL CBF when assuming a constant labeling efficiency of 0.86 was 75.2 ± 17.3 ml/100 g/min (p < 0.01), resulting in a mean absolute quantification error of 23% when a labeling efficiency appropriate for controls was assumed. This difference cannot be accounted for by BAT (whole‐brain BAT: control, 1.13 ± 0.06 s; SCA, 1.02 ± 0.09 s) or tissue T1 variation. In conclusion, BAT variation influences pCASL quantification less than elevated cervical arterial velocity and labeling efficiency variation in SCA adults; thus, a lower labeling efficiency (α = 0.72) or subject‐specific labeling efficiency should be incorporated for SCA patients.