bluuebunny/crossref_metadata_2025 huggingface dataset:
Growth and Characterization of α and β Polymorphs of l‐Glutamic Acid and its Anticancer and Antibacterial Application
Authors: Aarthi Jayaraj , Dhanasekaran Palanisamy , Senthil T. Subramaniyam , Ganesan N. Muthukrishnan
Published: April 2018

In this work, l‐glutamic acid polymorphs of metastable α and stable β crystals are grown by slow evaporation method. The selective additive l‐phenylalanine is added at different concentrations into the l‐glutamic acid aqueous solution and the effect of the additive on l‐glutamic acid polymorphs is reviewed. It is creating that at a level of 0.04 g/100 ml concentration, the additive contributes to the crystallization of l‐glutamic acid in α‐form. Powder X‐ray diffraction study of grown α and β crystals belongs to the orthorhombic crystal structure. The UV‐Vis spectral analysis of both α and β crystals have a high transparency range in the complete visible region. Functional groups present in the crystals are identified by FTIR spectroscopic analysis. DSC study reveals that both polymorphs is stable and does not show any phase transformation until their melting. Antibacterial activity study is carried out against human pathogens. DPPH radical scavenging study, exhibit good antioxidant activity and calculated the IC50 value of α (217.43 µg ml−1) and β (233.57 µg ml−1) polymorphs, this value comparable with standard Vitamin C (201.72 µg ml−1). The anticancer activity study identify the both polymorphs inhibit the cancer cell line and calculate the IC50 value of α (165.21µg ml−1) and β (145.49 µg ml−1) polymorphs.
Estimating sensitivity of seabed habitats to disturbance by bottom trawling based on the longevity of benthic fauna
Authors: Rijnsdorp Adriaan D. , Bolam Stefan G. , Garcia Clement , Hiddink Jan Geert , Hintzen Niels T. , van Denderen P. Daniel , van Kooten Tobias
Published: April 2018

Bottom fishing such as trawling and dredging may pose serious risks to the seabed and benthic habitats, calling for a quantitative assessment method to evaluate the impact and guide management to develop mitigation measures. We provide a method to estimate the sensitivity of benthic habitats based on the longevity composition of the invertebrate community. We hypothesize that long‐lived species are more sensitive to trawling mortality due to their lower pace of life (i.e., slower growth, late maturation). We analyze data from box‐core and grab samples taken from 401 stations in the English Channel and southern North Sea to estimate the habitat‐specific longevity composition of the benthic invertebrate community and of specific functional groups (i.e., suspension feeders and bioturbators), and examine how bottom trawling affects the longevity biomass composition. The longevity biomass composition differed between habitats governed by differences in sediment composition (gravel and mud content) and tidal bed‐shear stress. The biomass proportion of long‐lived species increased with gravel content and decreased with mud content and shear stress. Bioturbators had a higher median longevity than suspension feeders. Trawling, in particular by gears that penetrate the seabed >2 cm, shifted the community toward shorter‐lived species. Changes from bottom trawling were highest in habitats with many long‐lived species (hence increasing with gravel content, decreasing with mud content). Benthic communities in high shear stress habitats were less affected by bottom trawling. Using these relationships, we predicted the sensitivity of the benthic community from bottom trawling impact at large spatial scale (the North Sea). We derived different benthic sensitivity metrics that provide a basis to estimate indicators of trawling impact on a continuous scale for the total community and specific functional groups. In combination with high resolution data of trawling pressure, our approach can be used to monitor and assess trawling impact and seabed status at the scale of the region or broadscale habitat and to compare the environmental impact of bottom‐contacting fishing gears across fisheries.
Long‐term nutrient addition increases respiration and nitrous oxide emissions in a New England salt marsh
Authors: Martin Rose M. , Wigand Cathleen , Elmstrom Elizabeth , Lloret Javier , Valiela Ivan
Published: April 2018

Salt marshes may act either as greenhouse gas (GHG) sources or sinks depending on hydrological conditions, vegetation communities, and nutrient availability. In recent decades, eutrophication has emerged as a major driver of change in salt marsh ecosystems. An ongoing fertilization experiment at the Great Sippewissett Marsh (Cape Cod, USA) allows for observation of the results of over four decades of nutrient addition. Here, nutrient enrichment stimulated changes to vegetation communities that, over time, have resulted in increased elevation of the marsh platform. In this study, we measured fluxes of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) in dominant vegetation zones along elevation gradients of chronically fertilized (1,572 kg N ha−1 year−1) and unfertilized (12 kg N ha−1 year−1) experimental plots at Great Sippewissett Marsh. Flux measurements were performed using darkened chambers to focus on community respiration and excluded photosynthetic CO2 uptake. We hypothesized that N‐replete conditions in fertilized plots would result in larger N2O emissions relative to control plots and that higher elevations caused by nutrient enrichment would support increased CO2 and N2O and decreased CH4 emissions due to the potential for more oxygen diffusion into sediment. Patterns of GHG emission supported our hypotheses. Fertilized plots were substantially larger sources of N2O and had higher community respiration rates relative to control plots, due to large emissions of these GHGs at higher elevations. While CH4 emissions displayed a negative relationship with elevation, they were generally small across elevation gradients and nutrient enrichment treatments. Our results demonstrate that at decadal scales, vegetation community shifts and associated elevation changes driven by chronic eutrophication affect GHG emission from salt marshes. Results demonstrate the necessity of long‐term fertilization experiments to understand impacts of eutrophication on ecosystem function and have implications for how chronic eutrophication may impact the role that salt marshes play in sequestering C and N.
Monitoring individual tree‐based change with airborne lidar
Authors: Duncanson Laura , Dubayah Ralph
Published: April 2018

Understanding the carbon flux of forests is critical for constraining the global carbon cycle and managing forests to mitigate climate change. Monitoring forest growth and mortality rates is critical to this effort, but has been limited in the past, with estimates relying primarily on field surveys. Advances in remote sensing enable the potential to monitor tree growth and mortality across landscapes. This work presents an approach to measure tree growth and loss using multidate lidar campaigns in a high‐biomass forest in California,USA. Individual tree crowns were delineated in 2008 and again in 2013 using a 3D crown segmentation algorithm, with derived heights and crown radii extracted and used to estimate individual tree aboveground biomass. Tree growth, loss, and aboveground biomass were analyzed with respect to tree height and crown radius. Both tree growth and loss rates decrease with increasing tree height, following the expectation that trees slow in growth rate as they age. Additionally, our aboveground biomass analysis suggests that, while the system is a net source of aboveground carbon, these carbon dynamics are governed by size class with the largest sources coming from the loss of a relatively small number of large individuals. This study demonstrates that monitoring individual tree‐based growth and loss can be conducted with multidate airborne lidar, but these methods remain relatively immature. Disparities between lidar acquisitions were particularly difficult to overcome and decreased the sample of trees analyzed for growth rate in this study to 21% of the full number of delineated crowns. However, this study illuminates the potential of airborne remote sensing for ecologically meaningful forest monitoring at an individual tree level. As methods continue to improve, airborne multidate lidar will enable a richer understanding of the drivers of tree growth, loss, and aboveground carbon flux.
Weather conditions determine attenuation and speed of sound: Environmental limitations for monitoring and analyzing bat echolocation
Authors: Goerlitz Holger R.
Published: April 2018

Echolocating bats are regularly studied to investigate auditory‐guided behaviors and as important bioindicators. Bioacoustic monitoring methods based on echolocation calls are increasingly used for risk assessment and to ultimately inform conservation strategies for bats. As echolocation calls transmit through the air at the speed of sound, they undergo changes due to atmospheric and geometric attenuation. Both the speed of sound and atmospheric attenuation, however, are variable and determined by weather conditions, particularly temperature and relative humidity. Changing weather conditions thus cause variation in analyzed call parameters, limiting our ability to detect, and correctly analyze bat calls. Here, I use real‐world weather data to exemplify the effect of varying weather conditions on the acoustic properties of air. I then present atmospheric attenuation and speed of sound for the global range of weather conditions and bat call frequencies to show their relative effects. Atmospheric attenuation is a nonlinear function of call frequency, temperature, relative humidity, and atmospheric pressure. While atmospheric attenuation is strongly positively correlated with call frequency, it is also significantly influenced by temperature and relative humidity in a complex nonlinear fashion. Variable weather conditions thus result in variable and unknown effects on the recorded call, affecting estimates of call frequency and intensity, particularly for high frequencies. Weather‐induced variation in speed of sound reaches up to about ±3%, but is generally much smaller and only relevant for acoustic localization methods of bats. The frequency‐ and weather‐dependent variation in atmospheric attenuation has a threefold effect on bioacoustic monitoring of bats: It limits our capability (1) to monitor bats equally across time, space, and species, (2) to correctly measure frequency parameters of bat echolocation calls, particularly for high frequencies, and (3) to correctly identify bat species in species‐rich assemblies or for sympatric species with similar call designs.
Comparative gel‐based proteomic analysis of chemically crosslinked complexes in dystrophic skeletal muscle
Authors: Murphy Sandra , Zweyer Margit , Mundegar Rustam R. , Swandulla Dieter , Ohlendieck Kay
Published: April 2018

Duchenne muscular dystrophy is a highly progressive muscle wasting disease with a complex pathophysiology that is based on primary abnormalities in the dystrophin gene. In order to study potential changes in the oligomerization of high‐molecular‐mass protein complexes in dystrophic skeletal muscle, chemical crosslinking was combined with mass spectrometric analysis. The biochemical stabilization of protein interactions was carried out with the homo‐bifunctional and amine‐reactive agent bis[sulfosuccinimidyl]suberate, followed by protein shift analysis in one‐dimensional gels. The proteomic approach identified 11 and 15 protein species in wild type versus dystrophic microsomal fractions, respectively, as well as eight common proteins, with an electrophoretic mobility shift to very high molecular mass following chemical crosslinking. In dystrophin‐deficient preparations, several protein species with an increased tendency of oligomerisation were identified as components of the sarcolemma and its associated intra‐ and extracellular structures, as well as mitochondria. This included the sarcolemmal proteins myoferlin and caveolin, the cytoskeletal components vimentin and tubulin, extracellular collagen alpha‐1(XII) and the mitochondrial trifunctional enzyme and oxoglutarate dehydrogenase. These changes are probably related to structural and metabolic adaptations, especially cellular repair processes, which agrees with the increased oligomerisation of myosin‐3, myosin‐9 and actin, and their role in cellular regeneration and structural adjustments in dystrophinopathy.
Response of tall buildings to base rocking induced by Rayleigh waves
Authors: Meza Fajardo Kristel C. , Papageorgiou Apostolos S.
Published: April 2018

By now, it is well known that long‐period surface waves can induce resonant response in high‐rise buildings, in particular those located in sedimentary basins. Rayleigh wave passage has been reported to induce rocking motion at the base of the buildings which can increase displacement demands significantly. However, the building behavior to base rocking has not been extensively studied because commercially available instruments do not record rotational components of ground motion, and thus, rocking time histories have not been available to the analysts. In a recent study, we proposed an effective method for estimating the rocking associated with Rayleigh waves, which takes into account their frequency‐dependent phase velocities. In the present work, we select a number of recorded seismic motions which include surface waves on sedimentary basins from recent well‐recorded earthquake events. Then, we proceed to identify and extract the recorded surface waves by using the technique mentioned above. Using realistic soil‐structure analytical models that have been proposed in the published literature for high‐rise buildings, we study their response to Rayleigh waves as they respond to both translational and rocking motions. Of particular interest is to compare the response of such structures with and without the presence of rotational motions due to surface waves. Using the roof displacement and the building interstory drift as response quantities, our results indicate that demands are controlled by rotational (rocking) motions associated with Rayleigh waves.
The life cycle of crevasse splays as a key mechanism in the aggradation of alluvial ridges and river avulsion
Authors: van Toorenenburg Koen A. , Donselaar Marinus E. , Weltje Gert Jan
Published: April 2018

Accommodation space in the unconfined distal part of low‐gradient fluvial fans facilitates abundant floodplain deposition. Here, the development of crevasse splays plays a key role in the aggradation of alluvial ridges and subsequent river avulsion. This study presents an analysis of different stages in the evolution of crevasse splays based on observations made in the modern‐day Río Colorado dryland fluvial fan fringing the endorheic Altiplano Basin in Bolivia. A generic life cycle is proposed in which crevasse‐splay channels adjust towards a graded equilibrium profile with their lower‐lying distal termini acting as a local base level. Initial development is dominantly controlled by the outflow of floodwater, promoting erosion near the crevasse apex and deposition towards the splay fringes. When proximal incision advances to below the maximum level of floodplain inundation, return flow occurs during the waning stage of flooding. This floodwater reflux leads to a temporary repositioning of the local base level to the deeper trunk‐channel thalweg at the apex of the crevasse‐splay channels. The resultant decrease in the floodplainward gradient of these channels ultimately leads to backfilling and abandonment of the crevasse splay, leaving a subtle local elevation of the floodplain. Consecutive splays form an alluvial ridge through lateral amalgamation and subsequent vertical stacking, which is mirrored by the aggradation of their parent channel floor. As this alluvial ridge becomes increasingly perched above the surrounding floodplain, splay equilibration may cause incision of the levee crevasse down to or below its trunk channel thalweg, leading to an avulsion. The mechanisms proposed in this study are relevant to fluvial settings promoting progradational avulsions. The relatively rapid accumulation rate and high preservation potential of crevasse splays in this setting makes them an important constituent of the resultant fluvial stratigraphy, amongst which are hydrocarbon‐bearing successions. Copyright © 2018 John Wiley & Sons, Ltd.
Relationship Between Relative Skeletal Muscle Mass and Nonalcoholic Fatty Liver Disease: A 7‐Year Longitudinal Study
Authors: Kim Gyuri , Lee Seung‐Eun , Lee You‐Bin , Jun Ji Eun , Ahn Jiyeon , Bae Ji Cheol , Jin Sang‐Man , Hur Kyu Yeon , Jee Jae Hwan , Lee Moon‐Kyu , Kim Jae Hyeon
Published: April 2018

Nonalcoholic fatty liver disease (NAFLD) has been associated with relative skeletal muscle mass in several cross‐sectional studies. We explored the effects of relative skeletal muscle mass and changes in relative muscle mass over time on the development of incident NAFLD or the resolution of baseline NAFLD in a large, longitudinal, population‐based 7‐year cohort study. We included 12,624 subjects without baseline NAFLD and 2943 subjects with baseline NAFLD who underwent health check‐up examinations. A total of 10,534 subjects without baseline NAFLD and 2631 subjects with baseline NAFLD were included in analysis of changes in relative skeletal muscle mass over a year. Subjects were defined as having NAFLD by the hepatic steatosis index, a previously validated NAFLD prediction model. Relative skeletal muscle mass was presented using the skeletal muscle mass index (SMI), a measure of body weight–adjusted appendicular skeletal muscle mass, which was estimated by bioelectrical impedance analysis. Of the 12,624 subjects without baseline NAFLD, 1864 (14.8%) developed NAFLD during the 7‐year follow‐up period. Using Cox proportional hazard analysis, compared with the lowest sex‐specific SMI tertile at baseline, the highest tertile was inversely associated with incident NAFLD (adjusted hazard ratio [AHR] = 0.44, 95% confidence interval [CI] = 0.38‐0.51) and positively associated with the resolution of baseline NAFLD (AHR = 2.09, 95% CI = 1.02‐4.28). Furthermore, compared with the lowest tertile of change in SMI over a year, the highest tertile exhibited a significant beneficial association with incident NAFLD (AHR = 0.69, 95% CI = 0.59‐0.82) and resolution of baseline NAFLD (AHR = 4.17, 95% CI = 1.90‐6.17) even after adjustment for baseline SMI. Conclusion: Increases in relative skeletal muscle mass over time may lead to benefits either in the development of NAFLD or the resolution of existing NAFLD.
External validation of the United Kingdom‐primary biliary cholangitis risk scores of patients with primary biliary cholangitis treated with ursodeoxycholic acid
Authors: Cheung Angela C. , Gulamhusein Aliya F. , Juran Brian D. , Schlicht Erik M. , McCauley Bryan M. , de Andrade Mariza , Atkinson Elizabeth J. , Lazaridis Konstantinos N.
Published: April 2018

The United Kingdom‐Primary Biliary Cholangitis (UK‐PBC) risk scores are a set of prognostic models that estimate the risk of end‐stage liver disease in patients with PBC at 5‐, 10‐ and 15‐year intervals. They have not been externally validated outside the United Kingdom. In this retrospective, external validation study, data were abstracted from outpatient charts and discrimination and calibration of the UK‐PBC risk scores were assessed. A total of 464 patients with PBC treated with ursodeoxycholic acid were included. The median diagnosis age was 52.4 years, and 88% were female patients. The cumulative incidence of events was 6%, 9%, and 15% at 5, 10, and 15 years, respectively. Concordance (c‐statistic) was 0.88, 0.85, and 0.84 using the 5‐, 10‐ and 15‐year risk scores, respectively, which was slightly lower than values observed in the United Kingdom validation cohort. Using the 5‐year risk score, more events were observed than predicted (25 versus 16.8; P = 0.046); using the 10‐year risk score, there was no difference between the observed and predicted number of events (35 versus 44.9; P = 0.14); conversely, using the 15‐year risk score, fewer events were observed than predicted (46 versus 67.5; P = 0.009). Limiting evaluation by the 15‐year UK‐PBC risk score to those with >10 years of follow‐up demonstrated no difference between observed and predicted events. Using the 5‐year risk score, patients within the highest quartile had statistically significant worse event‐free survival compared to the rest of the cohort: 82% versus 98% at 5 years, 73% versus 97% at 10 years, and 58% versus 93% at 15 years. Conclusion: In patients assessed at a North American tertiary medical center, the UK‐PBC risk score had excellent discrimination and was reasonably calibrated both in the short and long term. (Hepatology Communications 2018;2:676‐682)
Effect of carboxyl graphene nanofluid on automobile radiator performance
Authors: Sumanth S , Babu Rao P , Krishna V , Seetharam TR , Seetharamu KN
Published: April 2018

Nanofluid is a promising solution for the improvement of the radiator performance. In the current research work, the effect of the nanofluid carboxyl graphene on the performance of a radiator is studied. Carboxyl graphene nanoplatelets are added to 50:50 ethylene glycol–distilled water at three concentrations of 0.02, 0.03, and 0.04 vol%. The liquid flow rate is varied from 3 liters per minute (LPM) to 6 LPM, and the inlet liquid to the radiator has been maintained at constant temperatures of 40 °C and 50 °C. The inlet air Reynolds number is varied between 1200 and 2500. The effects of these on performance parameters such as Nusselt number, effectiveness, and friction factor are investigated. It is observed that addition of carboxyl graphene nanoplatelets increases the Nusselt number and effectiveness of radiator while friction factor is unaltered. The effectiveness of radiator increases by 27.38% and 23.41% for inlet temperatures of 40 °C and 50 °C respectively at 0.02 vol% and 5 LPM flow rate.
Molecular progression to cervical precancer, epigenetic switch or sequential model?
Authors: Nedjai Belinda , Reuter Caroline , Ahmad Amar , Banwait Rawinder , Warman Rhian , Carton James , Boer Sabrina , Cuzick Jack , Lorincz Attila T.
Published: April 2018

The evolution of precancerous cervical lesions is poorly understood. A widely held model of cervical intraepithelial neoplasia grade 3 (CIN3) development is sequential progression from normal through CIN1 and CIN2 to CIN3. Another hypothesis, the “molecular switch” model, postulates that CIN3 can evolve directly from human papillomavirus (HPV)‐infected normal epithelium without progressing through CIN1 and CIN2. To shed light on this process, we compared DNA methylation of selected human biomarkers and HPV types in two groups of CIN1: CIN1 that were near or adjacent to CIN3 (adjacent‐CIN1) and CIN1 that were the principal lesions with no CIN3 detected (principal‐CIN1). 354 CIN (CIN1 and CIN3) and normal tissue areas were dissected and typed for HPV from 127 women who underwent loop electrosurgical excision procedures (LEEP). Methylation of genes EPB41L3 and the viral regions of HPV16‐L1/L2, HPV18‐L2, HPV31‐L1, and HPV33‐L2 were determined by a highly accurate quantitative pyrosequencing of bisulfite converted DNA. There was a significant trend of increased methylation with disease grade comparing normal to CIN1 and CIN3 (p < 0.0001). Adjacent‐CIN1 predominantly shared the same HPV types as the CIN3, however, methylation differed substantially between adjacent‐CIN1 and CIN3 (p = 0.008). In contrast diagnostically principal‐CIN1 had an indistinguishable methylation distribution compared to adjacent‐CIN1 (EPB41L3: p = 0.49; HPVme‐All: p = 0.11). Our results suggest that progression from normal epithelium to CIN1 or CIN3 is usually promoted by the same HPV type but occurs via distinct DNA epigenotypes, thus favoring the “molecular switch” model.
Generating anchors only to lose them: The unusual story of glycosylphosphatidylinositol anchor biosynthesis and remodeling in yeast and fungi
Authors: Komath Sneha Sudha , Singh Sneh Lata , Pratyusha Vavilala A. , Sah Sudisht Kumar
Published: April 2018

Glycosylphosphatidylinositol (GPI)‐anchored proteins (GPI‐APs) are present ubiquitously at the cell surface in all eukaryotes. They play a crucial role in the interaction of the cell with its external environment, allowing the cell to receive signals, respond to challenges, and mediate adhesion. In yeast and fungi, they also participate in the structural integrity of the cell wall and are often essential for survival. Roughly four decades after the discovery of the first GPI‐APs, this review provides an overview of the insights gained from studies of the GPI biosynthetic pathway and the future challenges in the field. In particular, we focus on the biosynthetic pathway in Saccharomyces cerevisiae, which has for long been studied as a model organism. Where available, we also provide information about the GPI biosynthetic steps in other yeast/ fungi. Although the core structure of the GPI anchor is conserved across organisms, several variations are built into the biosynthetic pathway. The present Review specifically highlights these variations and their implications. There is growing evidence to suggest that several phenotypes are common to GPI deficiency and should be expected in GPI biosynthetic mutants. However, it appears that several phenotypes are unique to a specific step in the pathway and may even be species‐specific. These could suggest the points at which the GPI biosynthetic pathway intersects with other important cellular pathways and could be points of regulation. They could be of particular significance in the study of pathogenic fungi and in identification of new and specific antifungal drugs/ drug targets. © 2018 IUBMB Life, 70(5):355–383, 2018
Normalized difference set tiling conjecture
Authors: Tabak Kristijan
Published: April 2018

A difference set tiling in a group G is a collection of its difference sets that partition . It can exist in an abelian as well as in a nonabelian group. A tiling is normalized if a product of elements in each difference set equals 1. All known cases in abelian groups are normalized. Ćustić, Krčadinac, and Zhou made a conjecture that this is necessary. We will call it a normalized tiling conjecture (NTC). Using character theory, we prove that NTC is true for where v is odd. Also, if difference set has a multiplier, we prove that NTC is also true.
Circular RNA hsa_circ_0008344 regulates glioblastoma cell proliferation, migration, invasion, and apoptosis
Authors: Zhou Jinxu , Wang Hongxiang , Chu Junsheng , Huang Qilin , Li Guangxu , Yan Yong , Xu Tao , Chen Juxiang , Wang Yuhai
Published: April 2018

Background

Recent studies have found circular RNAs (circRNAs) involved in the biological process of cancers. However, little is known about their functional roles in glioblastoma.

Methods

Human circRNA microarray analysis was performed to screen the expression profile of circRNAs in IDH1 wild‐type glioblastoma tissue. The expression of hsa_circ_0008344 in glioblastoma and normal brain samples was quantified by qRT‐PCR. Functional experiments were performed to investigate the biological functions of hsa_circ_0008344, including MTT assay, colony formation assay, transwell assay, and cell apoptosis assay.

Results

CircRNA microarray revealed a total of 417 abnormally expressed circRNAs (>1.5‐fold, P < .05) in glioblastoma tissue compared with the adjacent normal brain. Hsa_circ_0008344, among the top differentially expressed circRNAs, was significantly upregulated in IDH1 wild‐type glioblastoma. Further in vitro studies showed that knockdown of hsa_circ_0008344 suppressed glioblastoma cell proliferation, colony formation, migration, and invasion, but increased cell apoptotic rate.

Conclusions

Hsa_circ_0008344 is upregulated in glioblastoma and may contribute to the progression of this malignancy.
On bipartite‐mixed graphs
Authors: Dalfó Cristina , Fiol Miquel Àngel , López Nacho
Published: April 2018

Mixed graphs can be seen as digraphs that have both arcs and edges (or digons, that is, two opposite arcs). In this article, we consider the case where such graphs are bipartite. As main results, we show that in this context the Moore‐like bound is attained in the case of diameter , and that bipartite‐mixed graphs of diameter do not exist.
Left atrial low‐voltage zone ablation of persistent atrial fibrillation in a patient with myotonic dystrophy: A case report
Authors: Otsubo Toyokazu , Tsuchiya Takeshi , Yamaguchi Takanori , Takahashi Naohiko
Published: April 2018

We here report a case of a 32‐year‐old man with genetically diagnosed myotonic dystrophy and persistent atrial fibrillation (AF) who underwent a low‐voltage zone (LVZ) ablation. His cardiac function was normal except for a prophylactic pacemaker implantation for a high risk of complete atrioventricular block. An LVZ was found in the anteroseptal left atrium during sinus rhythm and was ablated during induced AF after a pulmonary vein antrum isolation, which terminated the AF and rendered it noninducible by rapid pacing and/or isoproterenol. During 20 months of follow‐up, no atrial tachyarrhythmias were observed with pacemaker monitoring of antiarrhythmic drugs.
Influence of Human Milk and Parenteral Lipid Emulsions on Serum Fatty Acid Profiles in Extremely Preterm Infants
Authors: Nilsson Anders K. , Löfqvist Chatarina , Najm Svetlana , Hellgren Gunnel , Sävman Karin , Andersson Mats X. , Smith Lois E. H. , Hellström Ann
Published: April 2018

Background

Infants born prematurely are at risk of a deficiency in ω‐6 and ω‐3 long‐chain polyunsaturated fatty acids (LC‐PUFAs) arachidonic acid (AA) and docosahexaenoic acid (DHA). We investigated how fatty acids from breast milk and parenteral lipid emulsions shape serum LC‐PUFA profiles in extremely preterm infants during early perinatal life.

Methods

Ninety infants born < 28 weeks gestational age were randomized to receive parenteral lipids with or without the ω‐3 LC‐PUFAs eicosapentaenoic acid (EPA) and DHA (SMOFlipid: Fresenius Kabi, Uppsala, Sweden, or Clinoleic: Baxter Medical AB, Kista, Sweden, respectively). The fatty acid composition of infant serum phospholipids was determined from birth to postmenstrual age 40 weeks, and in mother's milk total lipids on postnatal day 7. Enteral and parenteral intake of LC‐PUFAs was correlated with levels in infant serum.

Results

Infants administered parenteral ω‐3 LC‐PUFAs received 4.4 and 19.3 times more DHA and EPA, respectively, over the first 2 weeks of life. Parenteral EPA but not DHA correlated with levels in infant serum. We found linear relationships between dietary EPA and DHA and infant serum levels in the Clinoleic (Baxter Medical AB) group. The volume of administered SMOFlipid (Fresenius Kabi) was inversely correlated with serum AA, whereas Clinoleic (Baxter Medical AB) inversely correlated with serum EPA and DHA.

Conclusions

There appears to be no or low correlation between the amount of DHA administered parenterally and levels measured in serum. Whether this observation reflects serum phospholipid fraction only or truly represents the amount of accreted DHA needs to be investigated. None of the parenteral lipid emulsions satisfactorily maintained high levels of both ω‐6 and ω‐3 LC‐PUFAs in infant serum.
Comparative study of semiconductor TiO2and noble metal Ag substrates: The differences between chemical enhancement and electromagnetic enhancement in SERS
Authors: Jiang Xin , Chen Yongliang , Du Juan , Li Xiuling , Shen Yu , Yang Ming , Han Xiaoxia , Yang Libin , Zhao Bing
Published: April 2018

The differences between electromagnetic enhancement and chemical enhancement in surface‐enhanced Raman scattering (SERS) and their deep insight are very important and valuable for the explanation of spectral behaviors and the practical application of SERS technique. In this work, the typical semiconductor substrate TiO2nanoparticles and noble‐metal substrate Ag colloid were selected as two representative SERS‐active substrates to investigate the differences between the electromagnetic (EM) mechanism and the charge‐transfer (CT) mechanism using 4‐mercaptobenzoic acid as probe molecule. The 4‐mercaptobenzoic acid molecules on two substrates exhibit the obvious differences in spectral behavior and signal intensity of SERS as well as the detectability, which can be attributed to the essential differences between the EM mechanism and the CT mechanism. The EM enhancement more depends on the behavior of the substrate, which more tends to be nonselective for the adsorbed molecules and their enhancement. The CT enhancement not only depends on the behavior of the substrate but also depends on the behavior of the adsorbed molecule due to the CT between substrate and molecule, which more tends to be selective for the adsorbed molecules and their enhancement. Moreover, it is also proved that the semiconductor (TiO2) SERS‐active substrate is characterized by the high stability and the recyclability.
Surface erosion and underground leakage of yellow soil on slopes in karst regions of southwest China
Authors: Dai Quanhou , Peng Xudong , Wang Peijiang , Li Changlan , Shao Hongbo
Published: April 2018

Surface erosion and underground leakage loss simultaneously exist on slopes with a double‐layered structure (surface and underground) and have caused rocky desertification in karst regions. Because of the great difficulty of directly determining the underground leakage loss of soil and water, soil erosion processes in this region remain unclear, especially underground leakage loss. The aim of this study was to reveal the plot‐scale characteristics of surface soil erosion and underground leakage loss of yellow soils on karst slopes. Simulated rainfall tests and field runoff plot monitoring were conducted to achieve this aim. We found that surface erosion formed on steep slopes (30°) or at greater rainfall intensities (over 50 mm hr−1) and that surface runoff and surface soil loss dominated the total runoff and soil loss on karst slopes at greater rainfall intensities. However, underground leakage loss always occurred at different slopes and rainfall intensities. For small rainfall intensity cases (lower than 80 mm hr−1), underground runoff and underground soil leakage loss dominated the total runoff and soil loss and showed an underground runoff ratio of over 90% and an underground soil leakage ratio of over 44%. Rainfall intensity had significant effects on surface runoff depth and surface soil loss rates but an insignificant influence on underground leakage loss. Slope gradient and slope length influenced the runoff yield, and slope degree had a greater effect on the surface soil loss than had slope length. This study improves our understanding of surface erosion and underground leakage loss in karst rocky desertification regions.
Composite PLA/PEG/nHA/Dexamethasone Scaffold Prepared by 3D Printing for Bone Regeneration
Authors: Li Xiaoyuan , Wang Yu , Wang Zigui , Qi Yanxin , Li Linlong , Zhang Peibiao , Chen Xuesi , Huang Yubin
Published: April 2018

3D printing has become an essential part of bone tissue engineering and attracts great attention for the fabrication of bioactive scaffolds. Combining this rapid manufacturing technique with chemical precipitation, biodegradable 3D scaffold composed of polymer matrix (polylactic acid and polyethylene glycol), ceramics (nano hydroxyapatite), and drugs (dexamethasone (Dex)) is prepared. Results of water contact angle, differential scanning calorimeter, and mechanical tests confirm that incorporation of Dex leads to significantly improved wettability, higher crystallinity degree, and tunable degradation rates. In vitro experiment with mouse MC3T3‐E1 cells implies that Dex released from scaffolds is not beneficial for early cell proliferation, but it improves late alkaline phosphatase secretion and mineralization significantly. Anti‐inflammation assay of murine RAW 264.7 cells proves that Dex released from all the scaffolds successfully suppresses lipopolysaccharide induced interleukin‐6 and inducible nitric oxide synthase secretion by M1 macrophages. Further in vivo experiment on rat calvarial defects indicates that scaffolds containing Dex promote osteoinduction and osteogenic response and would be promising candidates for clinical applications.
Metamaterial‐based compact UWB planar monopole antennas
Authors: Rajasekhar N. V. , Kumar D. Sriram
Published: April 2018

In this article, novel compact UWB antennas based on loading of via less composite right/left‐handed (CRLH) unit cells are presented. Two novel metamaterials (MTM)‐based CRLH‐TL unit cells have been designed. The dispersion characteristics of the proposed unit cells are numerically calculated which follows CRLH properties. We designed a via‐free version of the CRLH unit cell by using virtual ground concept which simplifies the fabrication process and decreases the costs. The additional impedance matching network has been eliminated by using the optimum location of feed offset. The resulting double via less CRLH unit cells loaded antenna's bandwidths are improved by proper realizing the unit cell parameters and merging of ZOR mode to other lower and higher order modes. The proposed antennas have compact dimension 25 × 15 × 1.6 mm3. The two proposed antennas have UWB characteristics such as 109% and 125% fractional bandwidth, respectively. The measured gain and efficiency have been obtained with desired values for UWB applications. Good agreement has been observed between simulated and measured results.
Architecture of a unified split P‐shaped swarming metamaterial for thermal mutation
Authors: Alam Jubaer M. , Faruque Mohammad R. I. , Hossain Mohammad J. , Islam Mohammad T.
Published: April 2018

The article imparts the architecture of a compact and combined split P‐shaped metamaterial unit cell that is felicitous for dual band of microwave frequency and it shows negative permeability and permittivity at those frequencies. Two split P‐shaped resonators are connected to each other by a metal ink to increase the electrical length and two modified split‐ring resonators (SRR) reside inside each of it. The 10 × 10 mm2 structure has been printed on FR‐4 and a correlation is made between the basic unit cell and array structures. An analogy was contrived on the performance after the analysis of unit cell and array structures to validate the performance of the proposed metamaterial. A great transmission coefficient having a band of 13 GHz with a 500 MHz band gap at the middle is demonstrated for all of these configurations. The effective parameters of the resonators cover C, X, and Ku‐band independently with double negative phenomena at X and Ku‐band with a frequency range of about 1.31 GHz. Having an auspicious design and wide range double negative characteristics, this structure can be applicable to convert radiation into usable form.
A K‐/Ka‐band concurrent dual‐band low‐noise amplifier employing a feedback notch technique with simultaneous passband gain and stopband rejection control
Authors: Lee Jaeyoung , Nguyen Cam
Published: April 2018

A K‐/Ka‐band concurrent dual‐band low‐noise amplifier (LNA) employing an inductor feedback dual‐band load is presented. The dual‐band LNA can control the passband gain and stopband rejection performances to overcome the gain and notch performance degradation from process variations by adjusting the bias level of the second‐stage's inverting amplifier. The concurrent dual‐band LNA achieves peak gains of 21.3/23.2 dB at 21.5/36.5 GHz, respectively, and best noise figures of 2.6/2.5 dB at the low/high passbands, respectively. The dual‐band LNA exhibits the best noise figure and gain‐balance performances as compared to those operating at similar frequencies.
Circularly polarized modular patch antenna array fed by substrate integrated waveguide
Authors: Špůrek Jan , Raida Zbyněk
Published: April 2018

In the letter, a circularly polarized antenna array of rectangular patches is presented. The radiating elements are fed by a substrate integrated waveguide network. The array is expected to be used as a reference design and as a base building block for creation of larger arrays.
Compact power splitter with harmonic suppression based on inductively loaded slow‐wave transmission lines
Authors: Selga J. , Coromina J. , Vélez P. , Fernández‐Prieto A. , Martinez‐Ros A. J. , Bonache J. , Aznar‐Ballesta F. , Martín F.
Published: April 2018

A compact microstrip power splitter based on a pair of 70.71 Ω impedance inverters implemented by means of inductively loaded slow‐wave transmission lines is designed and fabricated. As a result of the slow‐wave effect, associated to the presence of series‐connected semi‐lumped (meandered) inductors, the length of the constitutive inverters is 41% reduced. Moreover, because of periodicity (Bragg effect), such inverters exhibit a stop band functionality useful harmonic suppression. It is demonstrated that the number of unit cells of the inverters that are necessary to achieve efficient harmonic suppression simultaneously keeping unaltered the splitter response in the region of interest should be N = 2. The proposed power splitter is compact, neither vias nor defected ground structures are used in its design, and it exhibits efficient suppression up to at least the 2nd harmonic (at 5f0, where f0 is the design frequency).
Beam and polarization reconfigurable microstrip antenna based on parasitics
Authors: Allayioti Marion , Kelly James R. , Mittra Raj
Published: April 2018

This paper presents a dual‐notch polarization and beam reconfigurable microstrip antenna. It uses parasitics which incorporate switches to steer its beam away from boresight and dual notches which, again, incorporate switches to reconfigure between linear and circular polarization. The antenna is a low profile microstrip patch antenna which only uses a single feed, allowing it to be compact and simple in terms of its structure.
A comprehensive experimental study of whispering gallery modes in a cylindrical microresonator excited by a tilted fiber taper
Authors: Kavungal Vishnu , Farrell Gerald , Wu Qiang , Mallik Arun Kumar , Semenova Yuliya
Published: April 2018

Whispering gallery modes (WGMs) excitation in a cylindrical microresonator formed by a section of silica optical fiber has been studied. Evanescent light coupling into the microresonator is realized using a tapered optical fiber, fabricated by a microheater brushing technique. Several types of silica fibers with different diameters are studied as microresonators, and the influence of the resonator's diameter on the excitation of WGMs is investigated. The excitation of WGMs in a cylindrical fiber resonator were studied with changes to the tilt angle between the microcylinder and the fiber taper in the range of angles from a perpendicular position (0°) to large tilt angles (24°). The evolution of the fiber taper transmission spectrum with the change of the tilt angle results in changes in the intensity, broadening of and a blue shift in the WGM resonance spectra. Overall losses in the taper transmission spectrum decrease with the increase of the taper tilt angle from its perpendicular position, followed by a complete disappearance of the WGM resonances at large tilt angles greater than 20°.
A Ka‐band antenna based on an enhanced Franklin model for 5G cellular networks
Authors: Jilani Syeda Fizzah , Abbasi Qammer Hussain , Khan Zia Ullah , Loh Tian‐Hong , Alomainy Akram
Published: April 2018

This article presents a millimeter‐wave antenna to cover 28‐ and 38‐GHz bands recommended by Federal Communications Commission for the 5G cellular networks. The conventional narrowband Franklin antenna is modified geometrically to transform into a multiband antenna provided with a linear array arrangement to fit multiple patches in a compact assembly to achieve smaller form factor and improved gain profile. The suggested structural modifications are deployed to diversify the fundamental theory of Franklin antennas to generate wideband and multiple resonances. The measured results show an impedance bandwidth of 28–39 GHz covered by the three resonances. The realized gain is above 7 dBi in the complete range of operation, while the peak gain is 10.23 dBi at 36 GHz. The proposed antenna signifies its high potential to fulfill demands of 5G wireless systems.
A dual‐polarized biconical antenna for direction finding applications from 2 to 18 GHz
Authors: Manoochehri Omid , Darvazehban Amin , Salari Mohammad Ali , Khaledian Seiran , Erricolo Danilo , Smida Besma
Published: April 2018

An ultra‐wideband dual‐polarized structure based on a biconical antenna for direction finding application from 2 to 18 GHz is proposed. In addition to direction finding, the proposed structure may be used for broadband communications and radar systems. The structure consists of a biconical antenna that is surrounded by 5 layers of polarizers, which create slant polarization to receive both vertically and horizontally polarized signals. The VSWR is below 2.5 in the operational bandwidth. The whole structure has been simulated using CST software, fabricated, and measured. A good agreement between measurements and simulated results is observed.
A high gain broadband transmitarray antenna using dual‐resonant E‐shaped element
Authors: Luo Jun , Yang Fan , Xu Shenheng , Li Maokun , Gu Shengming
Published: April 2018

A high‐gain and broadband linear‐polarized transmitarray antenna is proposed in this paper, and its element is composed of 4 identical layers of E‐shaped patches separated by quarter‐wavelength air gaps. To cover the required phase range, the dual‐resonant E‐shaped element is developed; realizing broadband transmission, low cross‐polarization level, and stable oblique‐incident response. A transmitarray prototype using the 4‐layer E‐shaped element is designed, fabricated, and tested. The proposed transmitarray has a broad 1‐dB gain bandwidth of 15%, a high gain of 33.0 dBi, an aperture efficiency of 40%.
A novel dual‐band filtering power divider using SIR and MDS
Authors: Xing Yue Shuang , Wang Xin Huai , Fang Ling , Kang Le , Shi Xiao Wei
Published: April 2018

A novel dual‐band filtering power divider using stepped impedance resonator (SIR) and microstrip defect structure (MDS) is proposed in this paper. The power divider mainly consists of the SIRs, MDS, and couple lines instead of the quarter wavelength transmission lines. The SIR, which comprises two pairs of high and low impedance lines, can provide great flexibility for realizing dual‐band performance. The MDS, which has the bandstop characteristic, is applied to effectively suppress the harmonic of the dual‐band filtering power divider. Exact equations and design procedures are given based on strict theoretical analysis. As verification, a dual‐band filtering power divider with two passbands centred at 2.5 and 6.0 GHz is fabricated and measured. The experimental results show good performance and validate the design concept.
Ionizing radiation‐induced acoustics for radiotherapy and diagnostic radiology applications
Authors: Hickling Susannah , Xiang Liangzhong , Jones Kevin C. , Parodi Katia , Assmann Walter , Avery Stephen , Hobson Maritza , El Naqa Issam
Published: April 2018

Acoustic waves are induced via the thermoacoustic effect in objects exposed to a pulsed beam of ionizing radiation. This phenomenon has interesting potential applications in both radiotherapy dosimetry and treatment guidance as well as low‐dose radiological imaging. After initial work in the field in the 1980s and early 1990s, little research was done until 2013 when interest was rejuvenated, spurred on by technological advances in ultrasound transducers and the increasing complexity of radiotherapy delivery systems. Since then, many studies have been conducted and published applying ionizing radiation‐induced acoustic principles into three primary research areas: Linear accelerator photon beam dosimetry, proton therapy range verification, and radiological imaging. This review article introduces the theoretical background behind ionizing radiation‐induced acoustic waves, summarizes recent advances in the field, and provides an outlook on how the detection of ionizing radiation‐induced acoustic waves can be used for relative and in vivo dosimetry in photon therapy, localization of the Bragg peak in proton therapy, and as a low‐dose medical imaging modality. Future prospects and challenges for the clinical implementation of these techniques are discussed.