bluuebunny/crossref_metadata_2025 huggingface dataset:
A FAST study of quasi‐static structure (“Inverted‐V”) potential drops and their latitudinal dependence in the premidnight sector and ramifications for the current‐voltage relationship
Authors: Dombeck J. , Cattell C. , McFadden J.
Published: August 2013

Utilizing FAST satellite electron measurements, we present the first reported investigation of the dependency on latitude of quasi‐static structure (“inverted‐V”) potential drop magnitude (Φ). A trend of lower Φ at lower latitudes in the premidnight sector on field lines with dark foot points was observed. This trend is supported both statistically and in individual satellite crossings. The existence of two distinct peaks in occurrence probability for Φ was also observed: one between ~2 kV and 10 kV and the other at somewhat less than 1 kV. The relative occurrence of structures with Φ in the higher (>2 kV) peak is significantly reduced with decreasing latitude. This partially accounts for the statistical trend of lower potential drop magnitudes at lower latitudes. The two Φ occurrence frequency peaks correspond to two different regimes (one with eΦ/kTe ~ or > 1 and one with eΦ/kTe < 1). In the lower Φ (<1 kV, eΦ/kTe < ~1) regime which constitutes the vast majority of midlatitude events, these results are consistent with a voltage source configuration or more complex current‐voltage relation where source electron density rather than Φ is most directly controlled by the field‐aligned current density. These observations and their ramifications represent a significant step forward in the understanding of field‐aligned currents, auroral acceleration, and magnetospheric‐ionospheric coupling.
Azimuthal dependence of VLF propagation
Authors: Hutchins M. L. , Jacobson Abram R. , Holzworth Robert H. , Brundell James B.
Published: August 2013

The World Wide Lightning Location Network (WWLLN) is used to measure the normalized lightning electric field at three network stations in order to examine the sferic attenuation between the stroke and the station. The electric field measurements are normalized to the radiated very low frequency (VLF) stroke energy to allow direct comparisons of the many stroke‐station paths seen by WWLLN. Comparing past theoretical results and models show that WWLLN observes a stronger dependence of VLF propagation on magnetic azimuth compared to past work. The average attenuation over the water of eastward‐propagating sferics is found to be 1.13±0.35 dB/Mm during the day and 0.71±0.68 dB/Mm at night, with westward‐propagating sferics having average attenuation rates of 2.98±0.68 dB/Mm and 2.66±0.39 dB/Mm for day and night, respectively.
Electron demagnetization and heating in quasi‐perpendicular shocks
Authors: Mozer F. S. , Sundkvist D.
Published: August 2013

Field and plasma measurements made during a quasi‐perpendicular terrestrial bow shock crossing by the Time History of Events and Macroscale Interactions during Substorms (THEMIS) E spacecraft on 21 August 2010 show that the measured electric field, being as great as 300 mV/m in the ramp, produced potential fluctuations over an electron gyrodiameter, which were as much as 15 times greater than the electron temperature. This fact requires that the electrons were unmagnetized in the ramp as a result of being scattered many times in a single gyroperiod by the fluctuating electric field. Supporting observations include the facts that the perpendicular electron heating and the parallel electron heating were equal in magnitude and simultaneous in time within experimental uncertainties and a factor of about five smaller than expected for perpendicular adiabatic heating of magnetized electrons. The conclusion that the electrons were unmagnetized is generalized through observations of 70 bow shock crossings on THEMIS and 140 shock crossings on Cluster to conclude that electrons are at least frequently unmagnetized in shock ramps such that their trajectories are more random than adiabatic and that they are energized during their chaotic traversal of the shock by the cross‐shock quasi‐DC electric field in the Normal Incidence Frame.
SPARC Data Initiative: Comparison of water vapor climatologies from international satellite limb sounders
Authors: Hegglin M. I. , Tegtmeier S. , Anderson J. , Froidevaux L. , Fuller R. , Funke B. , Jones A. , Lingenfelser G. , Lumpe J. , Pendlebury D. , Remsberg E. , Rozanov A. , Toohey M. , Urban J. , von Clarmann T. , Walker K. A. , Wang R. , Weigel K.
Published: August 2013

Within the SPARC Data Initiative, the first comprehensive assessment of the quality of 13 water vapor products from 11 limb‐viewing satellite instruments (LIMS, SAGE II, UARS‐MLS, HALOE, POAM III, SMR, SAGE III, MIPAS, SCIAMACHY, ACE‐FTS, and Aura‐MLS) obtained within the time period 1978–2010 has been performed. Each instrument's water vapor profile measurements were compiled into monthly zonal mean time series on a common latitude‐pressure grid. These time series serve as basis for the “climatological” validation approach used within the project. The evaluations include comparisons of monthly or annual zonal mean cross sections and seasonal cycles in the tropical and extratropical upper troposphere and lower stratosphere averaged over one or more years, comparisons of interannual variability, and a study of the time evolution of physical features in water vapor such as the tropical tape recorder and polar vortex dehydration. Our knowledge of the atmospheric mean state in water vapor is best in the lower and middle stratosphere of the tropics and midlatitudes, with a relative uncertainty of ±2–6% (as quantified by the standard deviation of the instruments' multiannual means). The uncertainty increases toward the polar regions (±10–15%), the mesosphere (±15%), and the upper troposphere/lower stratosphere below 100 hPa (±30–50%), where sampling issues add uncertainty due to large gradients and high natural variability in water vapor. The minimum found in multiannual (1998–2008) mean water vapor in the tropical lower stratosphere is 3.5 ppmv (±14%), with slightly larger uncertainties for monthly mean values. The frequently used HALOE water vapor data set shows consistently lower values than most other data sets throughout the atmosphere, with increasing deviations from the multi‐instrument mean below 100 hPa in both the tropics and extratropics. The knowledge gained from these comparisons and regarding the quality of the individual data sets in different regions of the atmosphere will help to improve model‐measurement comparisons (e.g., for diagnostics such as the tropical tape recorder or seasonal cycles), data merging activities, and studies of climate variability.
Surface clear‐sky shortwave radiative closure intercomparisons in the Weather Research and Forecasting model
Authors: Ruiz‐Arias José A. , Dudhia Jimy , Santos‐Alamillos Francisco J. , Pozo‐Vázquez David
Published: August 2013

The ability of the Rapid Radiative Transfer Model for GCMs (RRTMG) and Goddard shortwave (SW) radiative schemes to reproduce global (GHI), direct (DNI), and diffuse (DIF) fluxes at the surface in clear‐sky conditions is examined within the Weather Research and Forecasting (WRF) modeling framework. The models were forced using measurements of precipitable water and aerosol optical properties from five AERONET sites and were evaluated against high‐quality observations of GHI, DNI, and DIF at four nearby or coincident sites of the SURFRAD network and one at the Atmospheric Radiation Measurement Central Facility in the contiguous US. In addition, the performance has been intercompared against the Dudhia broadband SW parameterization together with a regressive model to calculate DNI and DIF and the top‐class SMARTS2 SW spectral model. The role of aerosols has been investigated by running the models with and without aerosols. All of them have shown outstanding skill at predicting GHI within the range of the expected observational error, regardless of whether aerosol information is provided as input. When aerosol information is not provided, DNI and DIF are affected by strong biases. In contrast, providing observed aerosols as input solves the bias issue for DNI and nearly does for DIF using the RRTMG scheme. The RRTMG has also proven to have high potential skill for long‐term assessment of clear‐sky GHI, DNI, and DIF irradiance, as long as reliable aerosol inputs are provided. Considering its simplicity, the Dudhia scheme has also shown a remarkable ability for solar resource assessment in clear‐sky conditions.
The effects of ocean feedback on tropical cyclone energetics under idealized air‐sea interaction conditions
Authors: Ma Zhanhong , Fei Jianfang , Huang Xiaogang , Cheng Xiaoping
Published: August 2013

The effects of ocean feedback on the energetic characteristics of the tropical cyclone (TC) are investigated based on idealized TC‐ocean coupling simulations. Results reveal notable impacts of ocean response on TC energetics. The ocean feedback reduces the latent energy of TCs, and consequently less latent heat is released in TC clouds, which leads to an evident decrease of the kinetic energy. A bulk equivalent potential temperature (θe) budget analysis demonstrates that the upward heat fluxes at the top of the boundary layer, of comparable magnitudes with the surface heat fluxes, are significantly diminished by the ocean feedback. A relatively higher portion of energy extracted from the ocean has been retained by the boundary layer under influences of the ocean feedback. The air parcels in contact with the cold wake possess evidently lowered moist static energy. To evaluate the evolution of moist static energy following these cooled air parcels, a three‐dimensional Lagrangian analysis is conducted using a large sample of trajectory seeds. Statistical results indicate that there is a mixing process between the cooled and ambient air parcels that lasts mostly less than 240 min. Over 70% of the seeded air parcels approach to a radius of 30–90 km from the TC center before they obtain adequate energy from surrounding air to balance their negative asymmetric θe. Most of the cooled air parcels are warmed up in the boundary layer, thereby producing impacts on TC energetics through changing directly the moist static energy of the boundary layer. More work of real case simulations is required to generalize the findings reported herein.
Gravity waves generated by deep tropical convection: Estimates from balloon observations and mesoscale simulations
Authors: Jewtoukoff Valérian , Plougonven Riwal , Hertzog Albert
Published: August 2013

Convective gravity waves in the Tropics are studied by analyzing in situ measurements from long‐duration stratospheric balloons launched during the PreConcordiasi campaign (2010) and mesoscale simulations. An improved temporal resolution of the observations as well as the balloon quasi‐Lagrangian behavior allow an unprecedented investigation of the whole gravity wave spectrum. First, a case study of gravity waves generated by a developing cyclone, Tropical Storm Gelane (February 2010), is carried out using observations complemented by numerical simulations with the Weather Research and Forecast model, with a resolution down to 1 km. Distributions of momentum fluxes obtained from both data show reasonable agreement and emphasize waves with short wavelengths (<15 km) and short periods (<20 min). Still, some differences are also found, which can likely be related to errors of the modeled background flow. Second, observations from the whole PreConcordiasi flights are analyzed with an emphasis on gravity wave momentum fluxes. Their phase speed distribution has a robust shape, with maximum fluxes with near‐zero ground‐based phase speeds. Yet, significant momentum fluxes are also found for larger values, yielding a mean phase speed of about 27 ms−1. The momentum fluxes are concentrated in short episodes with intense values, and their intermittency is quantified using probability distribution functions and the Gini coefficient (0.5–0.6). The relative importance of convective and topographic sources are investigated, suggesting comparable intensities, but a greater occurrence frequency of convective events. Waves emitted by Tropical Storm Gelane do not stand out relative to other convective events.
Sulfur Analogs of Pyrimidine Bases: Synthesis of 2‐Alkylthio‐ and 4‐Alkylthio‐5‐bromouracils and In Silico Evaluation of Their Biological Activity
Authors: Bartkowiak Grażyna , Wyrzykiewicz Elżbieta , Schroeder Grzegorz
Published: August 2013

The general reactivity of alkylthiouracils under bromination conditions has been examined. Twenty 2‐alkylthio‐ and 4‐alkylthio‐5‐bromouracils of potential biological activity have been prepared. The structures of these compounds were confirmed by elemental and spectral (UV/vis, IR, and 1H‐NMR) analyses. The pharmacotherapeutical potential of the synthesized compounds has been predicted using Prediction of Activity Spectra for Substances (i.e., PASS) program.
Syntheses, Crystal Structures, and Spectral Characterization of Two Novel Quinolyl Substituted Triazoles
Authors: Shen Guo‐Ping , Jiang Jing‐Jing , Sun Feng , Shen Xuan , Zhu Dun‐Ru , Liu Xiao‐Qin
Published: August 2013

Two novel quinolyl substituted triazoles, 3‐(p‐methoxyphenyl)‐4‐amino‐5‐(2‐quinolyl)‐1,2,4‐triazole (5) and 3‐(p‐methoxyphenyl)‐4‐phenyl‐5‐(2‐quinolyl)‐1,2,4‐triazole (6), were successfully synthesized. The compound 5 was synthesized under solvothermal conditions, whereas 6 was prepared through a solution method. Both 5 and 6 were characterized with UV–vis, FTIR, 1H‐NMR, ESI‐MS spectra, and elemental analysis. Additionally, the absolute configurations of 5 and 6 were determined by single‐crystal X‐ray crystallography.
An Innovative Protocol for the Synthesis of 3‐(Pyridin‐2‐yl)‐5‐sec‐aminobiphenyl‐4‐carbonitriles and 9,10‐Dihydro‐3‐(pyridine‐2‐yl)‐1‐sec‐aminophenanthrene‐2‐carbonitriles
Authors: Patil Umesh D. , Mahulikar Pramod P.
Published: August 2013

Herein, we present an innovative, novel, and highly convenient protocol for the synthesis of 3‐(pyridin‐2‐yl)‐5‐sec‐aminobiphenyl‐4‐carbonitriles (6a, 6b, 6c, 6d, 6e, 6f, 6g) and 9,10‐dihydro‐3‐(pyridine‐2‐yl)‐1‐sec‐aminophenanthrene‐2‐carbonitriles (10a, 10b, 10c, 10d, 10e), which have been delineated from the reaction of 4‐sec‐amino‐2‐oxo‐6‐aryl‐2H‐pyran‐3‐carbonitrile (4a, 4b, 4c, 4d, 4e, 4f, 4g) and 4‐sec‐amino‐2‐oxo‐5,6‐dihydro‐2H‐benzo[h]chromene‐3‐carbonitriles (9a, 9b, 9c, 9d, 9e) with 2‐acetylpyridine (5) through the ring transformation reaction by using KOH/DMF system at RT. The salient feature of this procedure is to provide a transition metal‐free route for the synthesis of asymmetrical 1,3‐teraryls like 3‐(pyridin‐2‐yl)‐5‐sec‐aminobiphenyl‐4‐carbonitriles (6a, 6b, 6c, 6d, 6e, 6f, 6g) and 9,10‐dihydro‐3‐(pyridine‐2‐yl)‐1‐sec‐aminophenanthrene‐2‐carbonitriles (10a, 10b, 10c, 10d, 10e). The novelty of the reaction lies in the creation of an aromatic ring from 2H‐pyran‐2‐ones and 2H‐benzo[h]chromene‐3‐carbonitriles via two‐carbon insertion from 2‐acetylpyridine (5) used as a source of carbanion.
Venous thromboembolism prevention guidelines for medical inpatients: Mind the (implementation) Gap
Authors: Maynard Greg , Jenkins Ian H. , Merli Geno J.
Published: August 2013

BACKGROUND

Hospital‐associated nonsurgical venous thromboembolism (VTE) is an important problem addressed by new guidelines from the American College of Physicians (ACP) and American College of Chest Physicians (AT9).

METHODS

Narrative review and critique.

RESULTS

Both guidelines discount asymptomatic VTE outcomes and caution against overprophylaxis, but have different methodologies and estimates of risk/benefit. Guideline complexity and lack of consensus on VTE risk assessment contribute to an implementation gap. Methods to estimate prophylaxis benefit have significant limitations because major trials included mostly screening‐detected events. AT9 relies on a single Italian cohort study to conclude that those with a Padua score ≥4 have a very high VTE risk, whereas patients with a score <4 (60% of patients) have a very small risk. However, the cohort population has less comorbidity than US inpatients, and over 1% of patients with a score of 3 suffered pulmonary emboli. The ACP guideline does not endorse any risk‐assessment model. AT9 includes the Padua model and Caprini point‐based system for nonsurgical inpatients and surgical inpatients, respectively, but there is no evidence they are more effective than simpler risk‐assessment models.

CONCLUSIONS

New VTE prevention guidelines provide varied guidance on important issues including risk assessment. If Padua is used, a threshold of 3, as well as 4, should be considered. Simpler VTE risk‐assessment models may be superior to complicated point‐based models in environments without sophisticated clinical decision support. Journal of Hospital Medicine 2013;8:582–588. © 2013 Society of Hospital Medicine
Reduced replication capacity of influenza A(H1N1)pdm09 virus during the 2010–2011 winter season in Tottori, Japan
Authors: Tsuneki Akeno , Itagaki Asao , Tsuchie Hideaki , Tokuhara Misato , Okada Takayoshi , Narai Sakae , Kasagi Masaaki , Tanaka Kiyoshi , Kageyama Seiji
Published: August 2013

A novel swine‐origin influenza A(H1N1)pdm09 virus has been circulating in humans since March–April, 2009. The 2009–2010 epidemic involved predominantly a single subtype of A(H1N1)pdm09 (at 96%, 46/48) in the sentinel sites of this study. However, A(H1N1)pdm09 started to circulate together with other type/subtype (49%, 33/68) at the first peak in the next epidemic season in 2010–2011: A(H1N1)pdm09/A(H3N2) (9%, 6/68), A(H1N1)pdm09/B (35%, 24/68), and A(H1N1)pdm09/A(H3N2)/B (4%, 3/68). Single infection of A(H1N1)pdm09 became a rare event (8%, 5/65) at the second peak of the same season in 2010–2011 compared with that at the first peak (50%, 34/68). Concurrently with this decline, single infections of others, A(H3N2) or B, became evident (6%, 4/65; 14%, 9/65, respectively). Triple infections were more common (29%, 19/65) at the second peak than at the first peak (4%). The A(H1N1)pdm09 detected in 2010–2011 produced less virus upon 72 hr of incubation in vitro after the inoculations at 104 and 3,300 copies/ml (2.3 × 109 and 2.3 × 109 copies/ml on average) than that in 2009–2010 (3.7 × 109 and 1.3 × 1010 copies/ml on average; P < 0.05 by ANOVA test), respectively. As described above, the replication capacity of A(H1N1)pdm09 seems to have deteriorated in the 2010–2011 season presumably due to substantial herd immunity and allowed the existence of other type/subtype. These results suggest that assessment of replication capacity is indispensable for analysis of influenza epidemics. J Med. Virol. 85:1871–1877, 2013. © 2013 Wiley Periodicals, Inc.
Meta‐analysis of hypercoagulability genetic polymorphisms in perthes disease
Authors: Woratanarat Patarawan , Thaveeratitharm Charnwit , Woratanarat Thira , Angsanuntsukh Chanika , Attia John , Thakkinstian Ammarin
Published: August 2013

Perthes disease is an osteonecrosis of the femoral epiphysis with unclear etiology. This study aimed to systematically review the association between genetic determinants of hypercoagulability (Factor V Leiden, prothrombin II, and methylenetetrahydrofolate reductase; MTHFR) and Perthes disease. PubMed and Scopus searched from inception to January 2012, data extraction and quality assessment were performed. The odds ratio (OR) for the allele effect was pooled, and heterogeneity and publication bias were assessed. Twelve case–control studies met inclusion criteria and had sufficient data for extraction. There were 824 cases and 2,033 controls with a mean age range of 6.1–14.7 years. The prevalence of the minor allele in controls was 0.015 (95% confidence interval (CI): 0.008, 0.023), 0.012 (95% CI: 0.008, 0.017), and 0.105 (95% CI: 0.044, 0.167) for factor V Leiden, prothrombin II, and MTHFR, respectively. The factor V Leiden allele increased the risk of Perthes with a pooled OR of 3.10 (95% CI: 1.68, 5.72), while prothrombin II and MTHFR had non‐significantly pooled OR 1.48 (95% CI: 0.71, 3.08), and 0.97 (95% CI: 0.72, 1.30), respectively. The factor V Leiden mutation is significantly related to Perthes disease, and its screening in at‐risk children might be useful in the future. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:1–7, 2014.
Prolonged expansion of human nucleus pulposus cells expressing human telomerase reverse transcriptase mediated by lentiviral vector
Authors: Wu Jianhong , Wang Deli , Ruan Dike , He Qing , Zhang Yan , Wang Chaofeng , Xin Hongkui , Xu Cheng , Liu Yue
Published: August 2013

Human degenerative disc disease (DDD) is characterized by progressive loss of human nucleus pulposus (HNP) cells and extracellular matrix, in which the massive deposition are secreted by HNP cells. Cell therapy to supplement HNP cells to degenerated discs has been thought to be a promising strategy to treat DDD. However, obtaining a large quality of fully functional HNP cells has been severely hampered by limited proliferation capacity of HNP cells in vitro. Previous studies have used lipofectamine or recombinant adeno‐associated viral (rAAV) vectors to deliver human telomerase reverse transcriptase (hTERT) into ovine or HNP cells to prolong the activity of nucleus pulposus cells with limited success. Here we developed a lentiviral vector bearing both hTERT and a gene encoding green fluorescence protein (L‐hTERT/EGFP). This vector efficiently mediated both hTERT and EGFP into freshly isolated HNP cells. The expressions of both transgenes in L‐hTERT/EGFP transduced HNP cells were detected up to day 210 post viral infection, which was twice as long as rAAV vector did. Furthermore, we observed restored telomerase activity, maintained telomere length, delayed cell senescence, and increased cell proliferation rate in those L‐hTERT/EGFP transduced HNP cells. Our study suggests that lentiviral vector might be a useful gene delivery vehicle for HNP cell therapy to treat DDD. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:159–166, 2014.
Patient characteristics as predictors of clinical outcome of distraction in treatment of severe ankle osteoarthritis
Authors: Marijnissen A.C.A. , Hoekstra M.C.L. , Pré B.C. du , van Roermund P.M. , van Melkebeek J. , Amendola A. , Maathuis P. , Lafeber F.P.J.G. , Welsing P.M.J.
Published: August 2013

Osteoarthritis (OA) is a slowly progressive joint disease. Joint distraction can be a treatment of choice in case of severe OA. Prediction of failure will facilitate implementation of joint distraction in clinical practice. Patients with severe ankle OA, who underwent joint distraction were included. Survival analysis was performed over 12 years (n = 25 after 12 years). Regression analyses were used to predict failures and clinical benefit at 2 years after joint distraction (n = 111). Survival analysis showed that 44% of the patients failed, 17% within 2 years and 37% within 5 years after joint distraction (n = 48 after 5 years). Survival analysis in subgroups showed that the percentage failure was only different in women (30% after 2 years) versus men (after 11 years still no 30% failure). In the multivariate analyses female gender was predictive for failure 2 years after joint distraction. Gender and functional disability at baseline predicted more pain. Functional disability and pain at baseline were associated with more functional disability. Joint distraction shows a long‐term clinical beneficial outcome. However, failure rate is considerable over the years. Female patients have a higher chance of failure during follow‐up. Unfortunately, not all potential predictors could be investigated and other clinically significant predictors were not found. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:96–101, 2014.
Center variation in the use of nonstandardized model for end-stage liver disease exception points
Authors: Goldberg David S. , Makar George , Bittermann Therese , French Benjamin
Published: August 2013

The Model for End-Stage Liver Disease (MELD) score is an imperfect prognosticator of waitlist dropout, so transplant centers may apply for exception points to increase a waitlist candidate's priority on the waitlist. Exception applications are categorized as recognized exceptional diagnoses (REDs; eg, hepatocellular carcinoma) and non-REDs (eg, cholangitis). Although prior work has demonstrated regional variation in the use of exceptions, no work has examined the between-center variability. We analyzed all new waitlist candidates from February 27, 2002 to June 3, 2011 to explore variations in the use of non-REDs, for which no strict exception criteria exist. There were 58,641 new waitlist candidates, and 4356 (7.4%) applied for a non-RED exception. The number of applications increased steadily over time, as did the approval rates for such applications: from <50% in 2002 to nearly 75% in 2010. When we adjusted for patient factors, there was significant variability (P < 0.001) in the use of non-RED exceptions in 8 of 11 United Network for Organ Sharing (UNOS) regions and in the approval of these exceptions in 6 of 11 UNOS regions. The variability in the use and approval of non-REDs was clinically significant: waitlist candidates with approved exceptions were significantly more likely to undergo transplantation (68.3% versus 53.4%, P < 0.001) and were less likely to be removed for death or clinical deterioration (10.4% versus 16.2%, P < 0.001). Increased median MELD score at transplantation within a donor service area was the only center factor associated with increased odds of applying for exceptions, while no center factors were associated with having non-RED exceptions approved. Further work is needed to identify other sources of variation to ensure the appropriate and equitable use of non-RED exceptions. Liver Transpl 19:1330–1342, 2013. © 2013 AASLD.
Interleukin-28B and fibrosing cholestatic hepatitis in posttransplant hepatitis C: A case-control study and literature review
Authors: Duarte-Rojo Andres , Budhraja Vikram , Veldt Bart J. , Goldstein David D. , Watt Kymberly D. , Heimbach Julie K. , McHutchison John G. , Tillman Hans L. , Poterucha John J. , Charlton Michael R.
Published: August 2013

Chronic hepatitis C (CHC)–related cirrhosis is the leading indication for liver transplantation (LT). However, the recurrence of a hepatitis C virus (HCV) infection after transplantation is universal and is associated with worse outcomes. Fibrosing cholestatic hepatitis (FCH) is a particularly severe manifestation of a recurrent HCV infection and frequently results in graft failure and death. The identification of risk factors for FCH is important but has been limited by the low frequency of FCH. The interleukin-28B (IL-28B) genotype is important in an HCV infection: it is related to the clinical severity of an acute infection and may play a role in the development of FCH as well. Two hundred seventy-two consecutive LT cases for CHC were studied at a single institution. Consensus criteria were used to define an FCH cohort. The remainder of the study population served as a control group. The IL-28B genotype (at the rs12979860 locus) from both the donor and the recipient was determined, and other clinically relevant data were tabulated. A nonparametric statistical analysis was performed. Twelve cases of FCH were identified, and they were compared to a control group of 260 LT cases without FCH. A detailed analysis of clinical characteristics, including treatment responses and outcomes, was tabulated. FCH was associated with the earlier recurrence of HCV infections, higher HCV viral loads, and lower levels of immunosuppressive medications. There was a nonsignificant increase in recipient IL-28B non-CC genotypes in cases developing FCH. In conclusion, a high HCV viral load and earlier recurrence were identified as risk factors for FCH. It is still unclear what role immunosuppression plays in the pathogenesis of FCH and whether IL-28B polymorphisms constitute a risk factor. Collaborative studies with larger numbers of study subjects are needed in order to define these issues. Liver Transpl 19:1311-1317, 2013. © 2013 AASLD.
Validating posttransplant hepatocellular carcinoma recurrence data in the united network for organ sharing database
Authors: Samoylova Mariya L. , Dodge Jennifer L. , Vittinghoff Eric , Yao Francis Y. , Roberts John Paul
Published: August 2013

The Organ Procurement and Transplantation Network (OPTN)/United Network for Organ Sharing (UNOS) database is the most comprehensive collection of liver transplantation data, but the quality of these data with respect to hepatocellular carcinoma (HCC) recurrence has not been well assessed. In this study, we compared observed HCC recurrence rates in the UNOS database to expected rates calculated with a hierarchical model for recurrence adjusted for recipient and tumor characteristics. We used the UNOS Standard Transplant Analysis and Research data set for adult transplant patients with an initial exception for an HCC diagnosis granted between January 1, 2006 and September 30, 2010 who underwent transplantation within the same time window. We developed a risk-adjusted Poisson model with patients as the unit of analysis, random effects for transplant centers, and years of follow-up as an offset to predict expected recurrences for each center. To further investigate the possibility of underreporting, we imputed expected recurrences for non-HCC deaths. In all, 5034 HCC liver transplant recipients were identified, and 6.8% experienced recurrence at a median of 1 year after transplantation. The covariate-adjusted shrinkage estimates of the observed/expected HCC recurrence ratios by transplant center ranged from 0.6 to 1.76 (median = 0.97). The 95% confidence intervals for the shrinkage ratios included unity for every center, and this indicated that none could be unambiguously identified as having lower or higher than expected HCC recurrence rates. Imputing outcomes for patients potentially experiencing unreported recurrence changed the center-specific shrinkage ratios to 0.72 to 1.39 (median = 0.98), with no centers having a shrinkage ratio significantly different from 1. The observed HCC recurrence rate was not significantly lower than the expected rate at any center, and this suggests that no systematic underreporting has occurred. This study validates the OPTN HCC recurrence data and supports their potential for further analysis. Liver Transpl 19:1318–1323, 2013. © 2013 AASLD.
Delayed distally based sural flap with temporary venous supercharging
Authors: Fujiwara Masao , Nagata Takeshi , Matsushita Yuki , Ishikawa Kayoko , Yusuke Ohta , Fukamizu Hidekazu
Published: August 2013

The distally based sural flap has become popular for reconstruction of the foot and leg. However, this flap often fails due to venous congestion. In this report, we developed a new modification of the distally based sural flap. The procedure comprised three stages. In the first stage, the flap was raised cephalad to the midpoint of the posterior aspect of the leg, involving reanastomosis of the short saphenous vein (SSV) at the proximal end of the flap. In the second stage, ligature of the SSV was performed. In the third stage, the entire flap was raised. We treated eight patients with the flap. All flaps survived completely. Duplex scanning indicated that venous drainage of the flap was provided by the tenuous venae comitantes (VCs) surrounding the SSV. Reanastomosis of the SSV may prevent rapid venous overloading of the VCs. Our new modification may be useful to avoid venous congestion. © 2013 Wiley Periodicals, Inc. Microsurgery 33:534–538, 2013.
Influence of the pedicle orientation and length on viability of unipedicled venous island flaps
Authors: Han Seung‐Kyu , Kim Soo‐Young , Gu Ja Hea , Jeong Seong‐Ho , Kim Woo‐Kyung
Published: August 2013

The use of unipedicled venous flaps has been limited due to their unconventional perfusion patterns and inconsistent survival. Further information regarding the optimal conditions required for unipedicled venous flap coverage is needed to increase flap survival. The purpose of this study was to investigate the effect of the pedicle orientation and length on the viability of unipedicled venous flaps based on a review of our clinical experience. Thirty‐one skin and soft tissue hand defects of 29 patients were treated with unipedicled venous flaps. Sixteen defects were treated with proximally pedicled flaps and 15 were treated with distally pedicled flaps. Five of the 16 proximally pedicled flaps and eight of the 15 distally pedicled flaps had pedicle lengths ≥ 5 cm. All proximally pedicled flaps survived, and distally pedicled flaps with pedicle lengths <5 cm (n = 7) also survived. Distally pedicled flaps with pedicle lengths ≥5 cm (n = 8) developed congestion within 1–2 days after surgery, and external bleeding was applied. Four of the eight flaps survived completely, and partial necrosis developed in the other four. The results demonstrate that proximally pedicled venous flaps of the hand can survive regardless of pedicle length. Distally pedicled venous flaps can also survive completely when pedicle length is <5 cm. Distally pedicled venous flaps with pedicle lengths ≥5 cm should be used with caution. © 2013 Wiley Periodicals, Inc. Microsurgery 34:197–202, 2014.
Changes in WNT signaling‐related gene expression associated with development and cloning in bovine extra‐embryonic and endometrial tissues during the peri‐implantation period
Authors: Biase Fernando H. , Rabel Chanaka , Guillomot Michel , Sandra Olivier , Andropolis Kalista , Olmstead Colleen , Oliveira Rosane , Wallace Richard , Le Bourhis Daniel , Richard Christophe , Campion Evelyne , Chaulot‐Talmon Aurélie , Giraud‐Delville Corinne , Taghouti Géraldine , Jammes Hélène , Hue Isabelle , Renard Jean Paul , Lewin Harris A.
Published: August 2013

We determined if somatic cell nuclear transfer (SCNT) cloning is associated with WNT‐related gene expression in cattle development, and if the expression of genes in the WNT pathway changes during the peri‐implantation period. Extra‐embryonic and endometrial tissues were collected at gestation days 18 and 34 (d18, d34). WNT5A, FZD4, FZD5, LRP5, CTNNB1, GNAI2, KDM1A, BCL2L1, and SFRP1 transcripts were localized in extra‐embryonic tissue, whereas SFRP1 and DKK1 were localized in the endometrium. There were no differences in the localization of these transcripts in extra‐embryonic tissue or endometrium from SCNT or artificial insemination (AI) pregnancies. Expression levels of WNT5A were 11‐fold greater in the allantois of SCNT than AI samples. In the trophoblast, expression of WNT5A, FZD5, CTNNB1, and DKK1 increased significantly from d18 to d34, whereas expression of KDM1A and SFRP1 decreased, indicating that implantation is associated with major changes in WNT signaling. SCNT was associated with altered WNT5A expression in trophoblasts, with levels increasing 2.3‐fold more in AI than SCNT conceptuses from d18 to d34. In the allantois, expression of WNT5A increased 6.3‐fold more in SCNT than AI conceptuses from d18 to d34. Endometrial tissue expression levels of the genes tested did not differ between AI or SCNT pregnancies, although expression of individual genes showed variation across developmental stages. Our results demonstrate that SCNT is associated with altered expression of specific WNT‐related genes in extra‐embryonic tissue in a time‐ and tissue‐specific manner. The pattern of gene expression in the WNT pathway suggests that noncanonical WNT signal transduction is important for implantation of cattle conceptuses. Mol. Reprod. Dev. 80: 977–987, 2013. © 2013 Wiley Periodicals, Inc.
Targeting therapy to the neuromuscular junction: Proof of concept
Authors: Kusner Linda L. , Satija Namita , Cheng Georgiana , Kaminski Henry J.
Published: August 2013

Introduction: The site of pathology in myasthenia gravis (MG) is the neuromuscular junction (NMJ). Our goal was to determine the ability to direct complement inhibition to the NMJ. Methods: A single‐chain antibody directed against the alpha subunit of the acetylcholine receptor was synthesized (scFv‐35) and coupled to decay‐accelerating factor (DAF, scFv‐35‐DAF). scFv‐35‐DAF was tested in a passive model of experimentally acquired MG. Results: Administration of scFv‐35‐DAF to mice deficient in intrinsic complement inhibitors produced no weakness despite confirmation of its localization to the NMJ and no evidence of tissue destruction related to complement activation. Rats with experimentally acquired MG treated with scFV‐35‐DAF showed less weakness and a reduction of complement deposition. Conclusions: We demonstrate a method to effectively target a therapeutic agent to the NMJ. Muscle Nerve 49: 749–756, 2014
Inclusion‐body myositis presenting with facial diplegia
Authors: Ghosh Partha S. , Laughlin Ruple S. , Engel Andrew G.
Published: August 2013

Introduction: The hallmark clinical presentation of inclusion‐body myositis (IBM) is slowly progressive weakness that characteristically affects the quadriceps and finger and wrist finger flexor muscles. Facial weakness can also occur, but it is typically mild and not a prominent finding. Methods: We describe the clinical features, laboratory investigations, and muscle biopsy findings in a 58‐year old man who presented with a 6‐year history of marked progressive symmetrical facial weakness. Examination also showed shoulder abduction and hip extensor weakness. Results: The patient's serum creatine kinase level was 655 U/L, and electromyography showed fibrillation potentials and myopathic motor unit potentials. A biopsy specimen of the left biceps muscle was pathognomonic for IBM. Conclusions: This patient did not have a typical presentation for IBM but rather fulfilled the pathological criteria for IBM. To our knowledge, facial diplegia has not been reported previously as a presenting manifestation of IBM. Muscle Nerve 49: 287–289, 2014
Sources of Volunteer Motivation: Transformational Leadership and Personal Motives Influence Volunteer Outcomes
Authors: Dwyer Patrick C. , Bono Joyce E. , Snyder Mark , Nov Oded , Berson Yair
Published: August 2013

We examined the separate influences of volunteers' personal motives and their team leaders' behaviors on volunteer satisfaction and contributions, along with mediating processes suggested by self‐determination theory. Participants were 302 volunteers who worked in teams at various sites through a central agency. As predicted, both personal motives for volunteering and transformational leadership influenced volunteer satisfaction through enhanced work meaningfulness and higher‐quality team relationships. However, motives that predicted volunteer contribution were different from those that predicted satisfaction. Whereas satisfaction was positively associated with motives concerning esteem enhancement and value expression, contribution was positively associated with motives to gain understanding and negatively related to motives pertaining to esteem enhancement and social concerns. Transformational leadership was positively associated with volunteer satisfaction, but not with volunteer contributions. The theoretical ramifications of these findings are discussed, along with practical implications for the recruitment and retention of volunteers.
Thin Films: Past, Present, Future
Authors: Zweibel Ken
Published: August 2013

Thin‐film photovoltaics was developed as a means of substantially reducing the cost of photovoltaic (PV) systems. The rationale for this was that thin‐film modules would be cheaper to manufacture owing to their reduced material costs, energy costs, handling costs and capital costs. However, thin films had to he developed using new materials, including amorphous silicon, copper indium diselenide, cadmium telluride and film crystalline silicon. In all cases, these technologies faced major technical and financial hurdles. The most crucial technical barriers are described within the text. Today, much progress has been made and the performance of the best thin‐film laboratory cells approaches the best performance of polycrystalline silicon cells. Outdoor stability has been a problem, especially with amorphous silicon, but this material and newer thin films now display good to excellent stability. It appears that the goal of thin films—truly low‐cost PV electricity that can be sold into energy‐significant markets—can be achieved. However, its achievement will require both the continuing resolution of technical problems and the ongoing investment of significant public and/or private resources.
Thin‐film Photovoltaic Cells: Health and Environmental Issues in their Manufacture Use and Disposal
Authors: Fthenakis V. M. , Moskowitz P. D.
Published: August 2013

The large‐scale manufacture of thin‐film photovoltaic cells may present health and safety hazards if adequate precautions are not taken. In this paper, we examine the hazards associated with producing and using Si, CdTe and CIS thin‐film photovoltaic modules. We focus especially on the potential of workers in manufacturing facilities to be exposed to chronic, low levels of Cd. Pertinent regulations are reviewed and control options are presented that can minimize the risks to workers. Also, we investigate occupational safety hazards and the associated engineering and administrative options related to using pyrophoric silane in making amorphous silicon cells. Finully, recycling and disposal options for spent photovoltaic modules are discussed.
Polycrystalline Silicon‐Film™ Thin‐film Solar Cells: Advanced Products
Authors: Cotter J. E. , Barnett A. M. , Ford D. H. , Hall R. B. , Ingram A. E. , Rand J. A. , Ruffins T. R. , Shreve K. P. , Thomas C. J.
Published: August 2013

Thin‐film polycrystalline silicon has the potential to achieve the cost reduction and performance improvement necessary for large‐scale electricity markets. Reduced cost is achieved by capitalizing on the benefits of thin films grown on low‐cost, large‐area substrates. Improved efficiency is realized, in spite of reduced material quality, by incorporating enhanced optical absorption and back‐surface passivation. The cornerstone of AstroPower's thin‐film solar cell technology is the Silicon‐Film™ process: a method for the manufacture of solar cell‐quality, polycrystalline films of silicon on a variety of low‐cost, supporting substrates. Three thin‐film solar cell designs, based on this technology, are currently under development. This paper presents the key design features of these three products and briefly reviews the current status of the development of the key technologies that comprise the advanced thin‐film solar cell products.
Role of native point defects and Ga diffusion on electrical properties of degenerate Ga‐doped ZnO
Authors: Doutt Daniel R. , Balaz S. , Isabella L. , Look D. C. , Leedy K. D. , Brillson L. J.
Published: August 2013

We used a complement of depth‐resolved cathodoluminescence spectroscopy (DRCLS), X‐ray photoemission spectroscopy (XPS), and Hall‐effect measurements to demonstrate the interplay of Zn vacancy‐related (VZn‐R) defects with dopants in degenerately Ga‐doped ZnO grown by pulsed laser deposition. DRCLS VZn‐R/conduction band emission ratios relate to acceptor/donor concentrations, increasing rapidly for growth temperatures >400 °C, evidently because Ga atoms are inhibited from incorporating efficiently on available VZn sites. Elemental XPS depth profiles reveal a temperature‐dependent Ga interface segregation due to Ga bulk diffusion during growth. DRCLS Fermi level thresholds provide a useful indicator of carrier density, revealing depth variations in carrier density that anticorrelate with VZn‐R densities on a nm scale, confirming the acceptor nature of VZn‐R defects.
Unmasking the information encoded as structural motifs of viral RNA genomes: a potential antiviral target
Authors: Romero‐López Cristina , Berzal‐Herranz Alfredo
Published: August 2013

RNA viruses show enormous capacity to evolve and adapt to new cellular and molecular contexts, a consequence of mutations arising from errors made by viral RNA‐dependent RNA polymerase during replication. Sequence variation must occur, however, without compromising functions essential for the completion of the viral cycle. RNA viruses are safeguarded in this respect by their genome carrying conserved information that does not code only for proteins but also for the formation of structurally conserved RNA domains that directly perform these critical functions. Functional RNA domains can interact with other regions of the viral genome and/or proteins to direct viral translation, replication and encapsidation. They are therefore potential targets for novel therapeutic strategies. This review summarises our knowledge of the functional RNA domains of human RNA viruses and examines the achievements made in the design of antiviral compounds that interfere with their folding and therefore their function. Copyright © 2013 John Wiley & Sons, Ltd.
Ultrasound‒Mediated Synthesis of High‒Molecular Weight Polystyrene‒Grafted Silver Nanoparticles by Facile Ligand Exchange Reactions in Suspension
Authors: Pletsch Holger , Peng Ling , Mitschang Fabian , Schaper Andreas , Hellwig Michael , Nette David , Seubert Andreas , Greiner Andreas , Agarwal Seema
Published: August 2013

Ultrasound mediated facile ligand exchange method in suspension for the formation of polystyrene‒grafted silver nanoparticles is reported. Amazingly, this method allows even grafting of very high molecular weight polystyrenes (up to 217 200 g mol−1) having a single terminal thiol group at the chain end. Detailed studies are carried out to gain insights in the role of molecular weight of the ligands and the mechanism of the ligand exchange reactions. Key factors are determined to be the droplet formation by ultrasonification and low silver content, which enhances the availability of the terminal thiol end group significantly. The extraordinary compatibility of the ligand exchange method in particular regarding high molecular weights is attributed to hydrophilic orientation of the terminal thiol groups at the liquid‒liquid interphase. This is proved conclusively by using an in situ method as a reference approach in which agglomeration occurs at considerably lower molecular weights due to the absence of preferred end group orientation within the polymer coil. In homogeneous phase only the chain length is found to be the crucial factor in stabilization of silver nanoparticles.
Improved nonparametric inference for multiple correlated periodic sequences
Authors: Sun Ying , Hart Jeffrey D. , Genton Marc G.
Published: August 2013

This paper proposes a cross‐validation method for estimating the period as well as the values of multiple correlated periodic sequences when data are observed at evenly spaced time points. The period of interest is estimated conditional on the other correlated sequences. An alternative method for period estimation based on Akaike's information criterion is also discussed. The improvement of the period estimation performance is investigated both theoretically and by simulation. We apply the multivariate cross‐validation method to the temperature data obtained from multiple ice cores, investigating the periodicity of the El Niño effect. Our methodology is also illustrated by estimating patients’ cardiac cycle from different physiological signals, including arterial blood pressure, electrocardiography, and fingertip plethysmograph. Copyright © 2013 John Wiley & Sons Ltd