bluuebunny/crossref_metadata_2025_split huggingface dataset:
Perspectives on low voltage transmission electron microscopy as applied to cell biology
Authors: Bendayan Moise , Paransky Eugene 
Published: August 2014

ABSTRACTLow voltage transmission electron microscopy (LVTEM) with accelerating voltages as low as 5 kV was applied to cell biology. To take advantage of the increased contrast given by LVTEM, tissue preparation was modified omitting all heavy metals such as osmium, uranium, and lead from the fixation, on block staining and counterstaining. Nonstained ultra‐thin tissue sections (40 nm thick) generated highly contrasted images. While the aspect of the cells remains similar to that obtained by conventional TEM, some new substructures were revealed. The pancreatic acinar cells granules present a heterogeneous matrix with partitions corresponding to segregation of their different secretory proteins. Microvilli display their core of microfilaments anchored to the dense top membrane. Mitochondria revealed the presence of distinct particles along their cristea membranes that may correspond to the ATP synthase complexes or oxysomes. The dense nuclear chromatin displays a honey‐comb appearance while distinct beads aligned along thin threads were seen in the dispersed chromatin. These new features revealed by LVTEM correlate with structures described or predicted through other approaches. Masking effects due to thickness of the tissue sections and to the presence of heavy metals must have prevented their observation by conventional TEM. Furthermore, the immunogold was adapted to LVTEM revealing nuclear lamin‐A at the edge of the dense chromatin ribbons. Combining cytochemistry with LVTEM brings additional advantages to this new approach in cell biology. Microsc. Res. Tech. 77:999–1004, 2014. © 2014 Wiley Periodicals, Inc.
Characteristic time courses of cortical and medullary sodium signals measured by noninvasive 23Na‐MRI in rat kidney induced by furosemide
Authors: Liu Haiying , Zhou Dan , Garcia Maria L. , Kohler Martin G. , Shen Xiaolan , Williams Donald S. , Klimas Michael T. , Hargreaves Richard J. , Kaczorowski Gregory J. 
Published: August 2014

BackgroundTo characterize regional kidney sodium response by MRI following NKCC2 inhibition.MethodsRegional renal sodium signals were monitored noninvasively using 23Na‐MRI at 9.4T with a temporal resolution of 1.5 min in anesthetized rats (N = 14). A mild NKCC2 inhibition was induced using a slow intravenous furosemide infusion. Time course of sodium signal was modeled as an exponential transient with a single characteristic time constant.ResultsUnder normal physiological conditions, the renal sodium signals in medullary and cortical regions were stable and found to respond differently to furosemide challenge. Furosemide infusion at 1.2 mg/kg/h (N = 7) increased sodium signal in the cortex by 40 ± 6% (P < 7 × 10−5) whereas decreased in the medulla by 29 ± 2% (P < 3 × 10−6) with different temporal kinetics. The characteristic time constants of the change were determined to be: 8 ± 2 and 70 ± 10 min for medulla and cortex. Also, the medullary change occurred 9(±3) times faster than cortical independent of furosemide infusion rate up to 35 mg/kg/h.ConclusionThe pharmacological effects in terms of regional kidney sodium signal changes induced by NKCC2 inhibition are region‐specific and highly predictable. Using noninvasive sodium MRI, we obtained regional renal sodium kinetics data sets in response to a low dose furosemide infusion in normal rats. J. Magn. Reson. Imaging 2015;41:1622–1628. © 2014 Wiley Periodicals, Inc.
Outcomes with cytoreductive surgery and HIPEC for peritoneal metastasis
Authors: Ahmed Shuja , Stewart John H. , Shen Perry , Votanopoulos Konstantinos I. , Levine Edward A. 
Published: August 2014

AbstractPeritoneal metastasis (PM) has traditionally been approached with therapeutic nihilism. The evolution of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) over the last two decades, however, has caused a paradigm shift in treatment for PM. This modality is rapidly gaining acceptance as standard of care for PM from various cancers. This article reviews the current literature regarding the use of CRS/HIPEC for PM from the most common intra‐abdominal malignancies. J. Surg. Oncol. 2014 110:575–584. © 2014 Wiley Periodicals, Inc.
Effect of laser generated shockwaves 1 on ex‐vivo pigskin
Authors: Ramaprasad Vidyunmala , Navarro Artemio , Patel Shahzad , Patel Vikash , Nowroozi Bryan N. , Taylor Zach D. , Yong William , Gupta Vijay , Grundfest Warren S. 
Published: August 2014

IntroductionPersistent bacterial infection prolongs hospitalizations, leading to increased healthcare costs. Treatment of these infections costs several billion dollars annually. Biofilm production is one mechanism by which bacteria become resistant. With the help of biofilms, bacteria withstand the host immune response and are much less susceptible to antibiotics. Currently, there is interest in the use of laser‐generated shockwaves (LGS) to delaminate biofilm from infected wound surfaces; however, the safety of such an approach has not yet been established. Of particular concern are the thermal and mechanical effects of the shockwave treatment on the epidermis and the underlying collagen structure of the dermis. The present study is a preliminary investigation of the effect of LGS on freshly harvested ex vivo porcine skin tissue samples.Materials and MethodsTissue samples for investigation were harvested immediately post‐mortem and treated with LGS within 30 minutes. Previous studies have shown that laser fluences between 100 and 500 mJ/pulse are capable of delaminating biofilms off a variety of surfaces, thus our preliminary investigation focused on this range of laser energy. For each sample, LGS were produced via laser irradiation of a thin layer (0.5 µm) of titanium sandwiched between a 50 and 100 µm thick layer of water glass and a 0.1 mm thick sheet of Mylar. The rapid thermal expansion of the irradiated titanium film generates a transient compressive wave that is coupled through a liquid layer to the surface of the ex vivo pigskin sample. Shocked samples were immediately fixed in formalin and prepared for histological analysis. A blinded pathologist evaluated and scored each section on the basis of its overall appearance (O) and presence of linear/slit‐like spaces roughly parallel to the surface of the skin (S). The scores were given on a scale of 0–3.ResultsThe present investigation revealed no visible difference between the tissue sections of the control sample and those that were subjected to laser‐generated shockwaves. There was no relationship between the scores received by the samples and the energy with which they were shocked.ConclusionPreliminary investigation into the safety of the LGS treatment for biofilm delamination appears promising. Additional investigation will continue on ex vivo porcine samples, followed by an in vivo animal trial to better understand the physiological response to LGS treatment. Lasers Surg. Med. 46:620–627, 2014. © 2014 Wiley Periodicals, Inc.
Photoactive dye‐enhanced tissue ablation for endoscopic laser prostatectomy
Authors: Ahn Minwoo , Hau Nguyen Trung , Van Phuc Nguyen , Oh Junghwan , Kang Hyun Wook 
Published: August 2014

Background and ObjectiveLaser light has been widely used as a surgical tool to treat benign prostate hyperplasia (BPH) over 20 years. Recently, application of high laser power up to 200 W was often reported to swiftly remove a large amount of prostatic tissue. The purpose of this study was to validate the feasibility of photoactive dye injection to enhance light absorption and eventually to facilitate tissue vaporization with low laser power.Materials and MethodsChicken breast tissue was selected as a target tissue due to minimal optical absorption at the visible wavelength. Four biocompatible photoactive dyes, including amaranth (AR), black dye (BD), hemoglobin powder (HP), and endoscopic marker (EM), were selected and tested in vitro with a customized 532 nm laser system with radiant exposure ranging from 0.9 to 3.9 J/cm2. Light absorbance and ablation threshold were measured with UV–Vis spectrometer and Probit analysis, respectively, and compared to feature the function of the injected dyes. Ablation performance with dye‐injection was evaluated in light of radiant exposure, dye concentration, and number of injection.ResultsHigher light absorption by injected dyes led to lower ablation threshold as well as more efficient tissue removal in the order of AR, BD, HP, and EM. Regardless of the injected dyes, ablation efficiency principally increased with radiant exposure, dye concentration, and number of injection. Among the dyes, AR created the highest ablation rate of 44.2 ± 0.2 µm/pulse due to higher absorbance and lower ablation threshold. High aspect ratios up to 7.1 ± 0.4 entailed saturation behavior in the tissue ablation injected with AR and BD, possibly resulting from plume shielding and increased scattering due to coagulation. Preliminary tests on canine prostate with a hydraulic injection system demonstrated that 80 W with dye injection yielded comparable ablation efficiency to 120 W with no injection, indicating 33% reduced laser power with almost equivalent performance.ConclusionDue to efficient coupling of optical energy, pre‐injection of photoactive dyes promoted the degree of tissue removal during laser irradiation. Further studies will investigate spatial distribution of dyes and optimal injecting pressure to govern the extent of dye‐assisted ablation in a predictable manner. In‐depth comprehension on photoactive dye‐enhanced tissue ablation can help accomplish efficient and safe laser vaporization for BPH with low power application. Lasers Surg. Med. 46:703–711, 2014. © 2014 Wiley Periodicals, Inc.
Evaluation of two quantitative analysis methods of optical coherence tomography for detection of enamel demineralization and comparison with microhardness
Authors: Cara Ana C.B. , Zezell Denise M. , Ana Patricia A. , Maldonado Edison P. , Freitas Anderson Z. 
Published: August 2014

Background and ObjectiveWe aimed to evaluate in the same study two quantitative methods for quantification of incipient caries in human dental enamel by using optical coherence tomography (OCT): the optical attenuation coefficient and the area under the A‐scan signal, and to compare their results with those obtained from microhardness analysis.Study Design/Materials and MethodsOne hundred and sixty samples were obtained from 40 sound human third molars, which had their crowns sectioned. Simulated caries were created by a pH cycling method. OCT measurements were performed on the samples, before and after the induced demineralization. We determined the total optical attenuation coefficient from the OCT signal in each site and evaluated the sensitivity and specificity of this approach to the detection of the demineralization. Also, the areas under the OCT curves (AUC‐OCT) and those from sectional microhardness tests (AUC‐MH) were compared.ResultsBoth the analysis of the optical attenuation coefficient and the AUC‐OCT were adequate to efficiently distinguish sound and demineralized samples with sensitivity of 0.93 and specificity of 0.96. The AUC‐MH and the AUC‐OCT data presented linear relationship and correlation of 0.99.ConclusionBoth methods for signal analysis from OCT allowed detection of demineralization with good performance. The AUC‐OCT approach enables obtaining a linear relation with the microhardness results, for a quantitative assessment of mineral loss in human teeth. Lasers Surg. Med. 46:666–671, 2014. © 2014 Wiley Periodicals, Inc.
Ribosomal Proteins and Human Diseases: Pathogenesis, Molecular Mechanisms, and Therapeutic Implications
Authors: Wang Wei , Nag Subhasree , Zhang Xu , Wang Ming‐Hai , Wang Hui , Zhou Jianwei , Zhang Ruiwen 
Published: August 2014

AbstractRibosomes are essential components of the protein synthesis machinery. The process of ribosome biogenesis is well organized and tightly regulated. Recent studies have shown that ribosomal proteins (RPs) have extraribosomal functions that are involved in cell proliferation, differentiation, apoptosis, DNA repair, and other cellular processes. The dysfunction of RPs has been linked to the development and progression of hematological, metabolic, and cardiovascular diseases and cancer. Perturbation of ribosome biogenesis results in ribosomal stress, which triggers activation of the p53 signaling pathway through RPs–MDM2 interactions, resulting in p53‐dependent cell cycle arrest and apoptosis. RPs also regulate cellular functions through p53‐independent mechanisms. We herein review the recent advances in several forefronts of RP research, including the understanding of their biological features and roles in regulating cellular functions, maintaining cell homeostasis, and their involvement in the pathogenesis of human diseases. We also highlight the translational potential of this research for the identification of molecular biomarkers, and in the discovery and development of novel treatments for human diseases.
Relaxation and exchange dynamics of hyperpolarized 129Xe in human blood
Authors: Norquay Graham , Leung General , Stewart Neil J. , Tozer Gillian M. , Wolber Jan , Wild Jim M. 
Published: August 2014

Purpose129Xe‐blood NMR was performed over the full blood oxygenation range to evaluate 129Xe relaxation and exchange dynamics in human blood.MethodsHyperpolarized 129Xe was equilibrated with blood and isolated plasma, and NMR was performed at 1.5 T.ResultsThe 129Xe relaxation rate was found to increase nonlinearly with decreasing blood oxygenation. Three constants were extrapolated:
=  11.1, a “relaxivity index” characterizing the rate of change of 129Xe relaxation as a function of blood oxygenation, and
=  0.13 s−1 and
= 0.42 s−1, the 129Xe relaxation rates in oxygenated blood and deoxygenated blood, respectively. In addition, rate constants,
0.022 ms−1 and
=  0.062 ms−1, were determined for xenon diffusing between red blood cells (RBCs) and plasma (hematocrit  =  48%). The 129Xe‐O2 relaxivity in plasma,
= 0.075 s−1 mM−1, and the 129Xe relaxation rate in isolated plasma (without dissolved O2),
= 0.046 s−1, were also calculated. Finally, intrinsic 129Xe‐RBC relaxation rates,
= 0.19 s−1 and
= 0.84 s−1, in oxygenated blood and deoxygenated blood, respectively, were calculated.ConclusionThe relaxation and exchange analysis performed in this study should provide a sound experimental basis upon which to design future MR experiments for dissolved xenon transport from the lungs to distal tissues. Magn Reson Med 74:303–311, 2015. © 2014 Wiley Periodicals, Inc.
Quantitative contrast‐enhanced MRI with superparamagnetic nanoparticles using ultrashort time‐to‐echo pulse sequences
Authors: Gharagouzloo Codi Amir , McMahon Patrick N. , Sridhar Srinivas 
Published: August 2014

PurposeConventional MRI using contrast agents is semiquantitative because it is inherently sensitive to extravoxular susceptibility artifacts, field inhomogeneity, partial voluming, perivascular effects, and motion/flow artifacts. Herein we demonstrate a quantitative contrast‐enhanced MRI technique using ultrashort time‐to‐echo pulse sequences for measuring clinically relevant concentrations of ferumoxytol, a superparamagnetic iron oxide nanoparticle contrast agent with high sensitivity and precision in vitro and in vivo.MethodsThe method achieves robust, reproducible results by using rapid signal acquisition at ultrashort time‐to‐echo (UTE) to produce positive contrast images with pure T1 weighting and little T2* decay. The spoiled gradient echo equation is used to transform UTE intensities directly into concentration using experimentally determined relaxivity constants and image acquisition parameters.ResultsA multiparametric optimization of acquisition parameters revealed an optimal zone capable of producing high‐fidelity measurements. Clinically relevant intravascular concentrations of ferumoxytol were measured longitudinally in mice with high sensitivity and precision (∼7.1% error). MRI measurements were independently validated by elemental iron analysis of sequential blood draws. Automated segmentation of ferumoxytol concentration yielded high quality three‐dimensional images for visualization of perfusion.ConclusionsThis ability to longitudinally quantify blood pool CA concentration is unique to quantitative UTE contrast‐enhanced (QUTE‐CE) MRI and makes QUTE‐CE MRI competitive with nuclear imaging. Magn Reson Med 74:431–441, 2015. © 2014 Wiley Periodicals, Inc.
Fast group matching for MR fingerprinting reconstruction
Authors: Cauley Stephen F. , Setsompop Kawin , Ma Dan , Jiang Yun , Ye Huihui , Adalsteinsson Elfar , Griswold Mark A. , Wald Lawrence L. 
Published: August 2014

PurposeMR fingerprinting (MRF) is a technique for quantitative tissue mapping using pseudorandom measurements. To estimate tissue properties such as T1, T2, proton density, and B0, the rapidly acquired data are compared against a large dictionary of Bloch simulations. This matching process can be a very computationally demanding portion of MRF reconstruction.Theory and MethodsWe introduce a fast group matching algorithm (GRM) that exploits inherent correlation within MRF dictionaries to create highly clustered groupings of the elements. During matching, a group specific signature is first used to remove poor matching possibilities. Group principal component analysis (PCA) is used to evaluate all remaining tissue types. In vivo 3 Tesla brain data were used to validate the accuracy of our approach.ResultsFor a trueFISP sequence with over 196,000 dictionary elements, 1000 MRF samples, and image matrix of 128 × 128, GRM was able to map MR parameters within 2s using standard vendor computational resources. This is an order of magnitude faster than global PCA and nearly two orders of magnitude faster than direct matching, with comparable accuracy (1–2% relative error).ConclusionThe proposed GRM method is a highly efficient model reduction technique for MRF matching and should enable clinically relevant reconstruction accuracy and time on standard vendor computational resources. Magn Reson Med 74:523–528, 2015. © 2014 Wiley Periodicals, Inc.
Spirometric reference values for healthy Han children aged 5–15 years in Guangzhou, southern China
Authors: Jiang Mei , Gao Yi , Zhong Nan‐Shan , Chen Wei‐Qing , Guan Wei‐Jie , Zheng Jin‐Ping 
Published: August 2014

SummaryBackgroundReliable interpretation of spirometry rests on appropriate reference values, but there are few published reference values for healthy children in China.ObjectiveTo develop the updated spirometric normative values for healthy children aged 5–15 years in Guangzhou, southern China, and to explore the differences by comparison with published reference values.MethodsIn this cross‐sectional study, health questionnaire and physical examination conducted for screening healthy Han children. Spirometry was performed by well‐trained technicians according to American Thoracic Society guidelines. Using Lambda‐Mu‐Sigma (LMS) algorithm, predicted equations for the median and lower limits of normal were derived for forced vital capacity (FVC), forced expiratory volume in one second (FEV1), peak expiratory flow (PEF), and maximal mid‐expiratory flow (FEF25–75%). Predicted values were compared with other published spirometric reference equations.ResultsData were obtained from 422 healthy children (226 boys and 196 girls) aged 5–15 years. Spirometric parameters showed moderate‐to‐strong positive correlations with age, height, and weight in both genders, with height being the most crucial predictor. There were significant differences between spirometric values and other published reference values. Spirometric values were comparable with the data derived from the same area population in 2002, with exception of increased height and weight in the equivalent age groups.ConclusionsThe present spirometric reference equations are feasible for assessment of lung function among children in southern China. Further studies for establishment of reference values for Chinese children in other regions are needed. Pediatr Pulmonol. 2015; 50:1009–1016. © 2014 Wiley Periodicals, Inc.
An efficient strongly secure authenticated key exchange protocol without random oracles
Authors: Yang Zheng 
Published: August 2014

AbstractSince the introduction of extended Canetti–Krawczyk (eCK) security model for two‐party key exchange, many protocols have been proposed to provide eCK security. However, most of those protocols are provably secure in the random oracle model or rely on special design technique, which is well known as the NAXOS trick. In contrast to previous schemes, we present an eCK secure protocol in the standard model, without NAXOS trick and without knowledge of secret key assumption for public key registration. The security proof of our scheme is based on standard pairing assumption, collision‐resistant hash functions, Bilinear Decision Diffie–Hellman and Decision Linear Diffie–Hellman assumptions, and pseudo‐random functions with pairwise independent random source. Although our proposed protocol is based on bilinear groups, it does not require any pairing operation during key exchange procedure. Copyright © 2014 John Wiley & Sons, Ltd.
Urban middle school students' reflections on authentic science inquiry
Authors: Rivera Maulucci María S. , Brown Bryan A. , Grey Salina T. , Sullivan Shayna 
Published: August 2014

AbstractThis study explores the experiences of six urban middle school students in an authentic science inquiry program. Drawing on data including teaching journal entries, student work folders, and semi‐structured focus group interviews of six participants, the findings explore six dimensions of authentic science inquiry, an approach to science inquiry in which: (a) students develop authentic and personally relevant science knowledge; (b) students' funds of knowledge shape their inquiries; (c) students' relationships with science and sustained interest in science are transformed; (d) students' identities as potential scientists are affirmed; (e) students engage in science as a social enterprise; and (f) students develop a sense of agency. The findings situate authentic science inquiry as an individual and collective characteristic of learners and the learning community. We make the case that authentic science inquiry projects provide students with a greater sense of academic agency, afford students opportunities to gain expertise, and have the potential to challenge students' understandings of science, enhance how they see themselves in relationship to science, and improve their achievement in science. © 2014 Wiley Periodicals, Inc. J Res Sci Teach 51: 1119–1149, 2014
The climate–wildfire–air quality system: interactions and feedbacks across spatial and temporal scales
Authors: Stavros E. Natasha , McKenzie Donald , Larkin Narasimhan 
Published: August 2014

Future climate change and its effects on social and ecological systems present challenges for preserving valued ecosystem services, including local and regional air quality. Wildfire is a major source of air‐quality impact in some locations, and a substantial contributor to pollutants of concern, including nitrogen oxides and particulate matter, which are regulated to protect public and environmental health. Since climate change is expected to increase total area burned by wildfire and wildfires affect air quality, which is regulated, there is a need to define and study climate, wildfire, and air quality as one system. We review interactions and feedbacks acting across space and time within the climate–wildfire–air quality system, providing a foundation for integrated modeling and for assessing the ecological and social impacts of this system and its broader ecological, social, and scientific implications. WIREs Clim Change 2014, 5:719–733. doi: 10.1002/wcc.303This article is categorized under:

Assessing Impacts of Climate Change > Evaluating Future Impacts of Climate Change
Integrated Assessment of Climate Change > Applications of Integrated Assessment to Climate Change