bluuebunny/crossref_metadata_2025_split huggingface dataset:
Green synthesis of silver nanoparticles using tomato leaf extract and their entrapment in chitosan nanoparticles to control bacterial wilt
Authors: Santiago Thaís R , Bonatto Cínthia C , Rossato Maurício , Lopes Cláudio A P , Lopes Carlos A , G Mizubuti Eduardo S , Silva Luciano P 
Published: February 2019

AbstractBACKGROUNDSilver nanoparticles (AgNPs), particularly those entrapped in polymeric nanosystems, have arisen as options for managing plant bacterial diseases. Among the biopolymers useful for the entrapment of AgNPs, chitosan is promising because of its low cost, good biocompatibility, antimicrobial properties and biodegradability. The present study aimed: (i) to greenly‐synthesize AgNPs using different concentrations of aqueous extract of tomato leaves followed by entrapment of AgNPs with chitosan (CH‐AgNPs); (ii) to characterize the optical, structural and biological properties of the nanosystems produced; (iii) to evaluate the antimicrobial activities of AgNPs and nanomaterials; and (iv) to assess the effectiveness of AgNPs and nanomaterials for controlling tomato bacterial wilt caused byRalstonia solanacearum.RESULTSSpherical and oval AgNPs had incipient colloidal instability, although the concentration of the tomato leaf extract influenced both size (< 87 nm) and the polydispersity index. Nanomaterials (< 271 nm in size) were characterized by a highly stable matrix of chitosan containing polydisperse AgNPs. Free AgNPs and CH‐AgNPs were stable for up to 30 days, with no significant alteration in physicochemical parameters. The AgNPs and nanomaterials had antibacterial activity and decreased bacterial growth at micromolar concentrations after 48 h. Morphological changes inR. solanacearumcells were observed after treatment with CH‐AgNPs. The application of CH‐AgNPs at 256 µmol L−1reduced the incidence of bacterial wilt in a partially resistant tomato genotype but not in the susceptible line.CONCLUSIONGreenly‐synthesized chitosan‐derived nanomaterials containing AgNPs produced with leaf extracts from their own species appear to comprise a promising and sustainable alternative in an integrated management approach aiming to reduce the yield losses caused by bacterial wilt. © 2019 Society of Chemical Industry
Cross‐border infrastructural development and residents' perceived tourism impacts: A case of China–Pakistan Economic Corridor
Authors: Nazneen Shama , Xu Hong , Din Nizam Ud 
Published: February 2019

AbstractDrawing on social exchange theory, Butler's tourism area life cycle model, and previous literature, this study empirically tests direct and indirect relationships among perceived impacts of China–Pakistan Economic Corridor (CPEC) infrastructural development, perceived tourism impacts, and support for tourism development. Using a sample of 800 questionnaires in structural equation modeling, the tested model explores that perceived impacts of CPEC infrastructural development as an antecedent, directly and indirectly influences residents' support for tourism development. However, contrary to our predictions, the study finding indicates a positive relationship between perceived tourism costs and support for tourism development. This relationship addressed that residents are more likely to support tourism even if tourism costs outweigh the benefits.
Sonolocation during submandibular sialolithotomy
Authors: Romero Nahir J. , Fuson Andrew , Kieliszak Christopher R. , Joshi Arjun S. 
Published: February 2019

Objectives/HypothesisUltrasound is a proven tool for diagnostic and therapeutic purposes for treatment of salivary gland pathology. It is also useful for localization of calculi during submandibular gland transoral sialolithotomy when calculi cannot easily be palpated. Our objective was to determine the efficacy of sialolith localization using ultrasound during submandibular gland sialolithotomy.Study DesignRetrospective case series.MethodsA study performed utilizing data compiled from 2009 through 2016 in a tertiary academic center. Treatment was completed in 164 patients with sialadenitis and sialolithiasis by submandibular gland transoral sialolithotomy in either the office (81%) or the operating room (19%). Ultrasound was used for localization of sialoliths during submandibular gland sialolithotomy. Main treatment outcomes studied were success of the procedure, complications, and follow‐up.ResultsSuccessful sialolithotomy was performed in (147 patients) 90% of cases. Complications were minimal and included stricture formation, which occurred in 3% (five patients) of cases, followed by ranula formation in 1.8% (three patients) of cases. There were no incidences of lingual nerve injury.ConclusionsUltrasound can be used effectively for precise sialolith localization intraoperatively.Level of Evidence4Laryngoscope, 129:2716–2720, 2019
Survival under conditions of variable food availability: Resource utilization and storage in the cold‐water coral Lophelia pertusa
Authors: Maier Sandra R. , Kutti Tina , Bannister Raymond John , van Breugel Peter , van Rijswijk Pieter , van Oevelen Dick 
Published: February 2019

AbstractCold‐water coral (CWC) reefs are hotspots of biodiversity and productivity in the deep sea, but their distribution is limited by the availability of food, which undergoes complex local and temporal variability. We studied the resource utilization, metabolism, and tissue storage of CWC Lophelia pertusa during an experimentally simulated 3‐day food pulse, of 13C15N‐enriched phytodetritus, followed by a 4‐week food deprivation. Oxygen consumption (0.145 μmol O2 [mmol organic carbon {OC}]−1 h−1), release of particulate organic matter (0.029 μmol particulate organic carbon [POC] [mmol OC]−1 h−1 and 0.005 μmol particulate organic nitrogen [mmol OC]−1 h−1), ammonium excretion (0.004 μmol NH4+ [mmol OC]−1 h−1), tissue C and N content, and fatty acid (FA) and amino acid composition did not change significantly during the experiment. Metabolization of the labeled phytodetritus, however, underwent distinct temporal dynamics. Initially, L. pertusa preferentially used phytodetritus‐derived C for respiration (2.2 ± 0.36 nmol C [mmol OC]−1 h−1) and mucus production (0.94 ± 0.52 nmol C [mmol OC]−1 h−1), but those tracer fluxes declined exponentially to <20% within 2 weeks after feeding and then remained stable, indicating that the remainder of the incorporated phytodetritus had entered a tissue pool with lower turnover. Analysis of 13C in individual FAs revealed a mismatch between the FAs incorporated from phytodetritus and the FA requirements of the coral. We suggest that feeding on other resources, such as lipid‐rich zooplankton, could fill this deficiency. A release of 10% of their total OC as respired C and POC during the 4‐week food deprivation underlines the importance of regular food pulses for CWC reefs.
Environmental drivers of mixotrophs in boreal lakes
Authors: Hansson Truls Hveem , Grossart Hans‐Peter , del Giorgio Paul A. , St‐Gelais Nicolas F. , Beisner Beatrix E. 
Published: February 2019

AbstractMixotrophy is increasingly recognized as an important trophic pathway among phytoplankton, yet its underlying drivers remain largely unknown and unexplored. Here, we present a study utilizing 69 lake samplings in boreal Quebec, Canada, identifying variables driving the success of phytoplankton that have a capacity for mixotrophy and pointing to the underlying mechanisms. We found that the success of mixotrophs (% of total biomass) was positively influenced by both colored dissolved organic matter (cDOM) and dissolved CO2 concentration but limited by the abundance of crustacean zooplankton. The effect of cDOM manifested as a consequence of limited autotrophic phytoplankton biomass in lakes with reduced light penetration. We observed a nonlinear (u‐shaped) relation between CO2 and mixotrophs, with biomass favored at both low and high CO2 concentrations. A reduced fitness of mixotrophs at near‐atmospheric CO2 concentrations is likely owing to the costs of rapidly switching between or maintaining multiple trophic strategies. The abundance of zooplankton had a negative effect on mixotroph biomass but a positive effect on autotrophic phytoplankton. We also found that while the community composition of potentially mixotrophic phytoplankton was to some degree likely influenced by zooplankton biomass, composition was unaffected by the CO2 and cDOM gradients. Overall, this study highlights mixotrophy in boreal lake systems as a strategy of persistence, with the maintenance of a moderate but constant presence across a changing gradient of light and trophic conditions. The results of our study support the hypothesis that phytoplankton with a capacity for mixotrophy provide a superior and stable stoichiometric food source for zooplankton, implicating mixotrophs as a vital component of boreal lake food webs.
Phylogenetic signature of light and thermal stress for the endosymbiotic dinoflagellates of corals (Family Symbiodiniaceae)
Authors: Lesser Michael P. 
Published: February 2019

AbstractCoral reefs around the world have been affected by a climate‐change induced phenomenon known as “coral bleaching,” which is caused by the interaction between high irradiance and elevated seawater temperatures, and involves the mass expulsion of Symbiodiniaceae from anemones, sponges, and corals. The primary drivers of this phenomenon are the inherent genetic variability in the Family Symbiodiniaceae, and the variability in the abiotic environment for variables such as irradiance and temperature. Recent experiments have either disregarded the important interactive role of irradiance or have suggested that photooxidative stress is not a prerequisite for coral bleaching because certain reactive oxygen species (ROS) can be produced in the dark. Here, fluorescent probes are used as proxies for the relative concentration of ROS in different genera of cultured Symbiodiniaceae under varying thermal and light conditions. The results show that taxon‐specific patterns of the concentration of ROS are observed but that all genera tested produced significantly greater amounts of superoxide radicals and hydrogen peroxide, compared to singlet oxygen, when exposed to high light and thermal stress. These results are contextualized in relation to the primary drivers of ROS production and the photo‐physiological basis for differences in ROS production that may then be correlated with symbiont driven coral bleaching.
Ultra‐Broadband and Ultra‐Compact On‐Chip Silicon Polarization Beam Splitter by Using Hetero‐Anisotropic Metamaterials
Authors: Xu Hongnan , Dai Daoxin , Shi Yaocheng 
Published: February 2019

AbstractThe polarization beam splitter (PBS) is an essential component in the polarization diversity circuit to overcome the strong polarization dependence of silicon nanophotonic devices. Among various PBS structures, the asymmetrical directional couplers (ADCs) are most commonly used due to the best overall performances. However, it is still challenging to realize an on‐chip silicon PBS with a small footprint, low loss, high extinction ratio, and, especially, broad bandwidth, simultaneously. The working bandwidth is limited for ADCs, since the wavelength difference will introduce deviations to both the effective indices and the coupling strength, which would distort the phase‐matching property and the optimal coupling length. In this paper, an on‐chip silicon PBS is proposed and demonstrated using “effective medium anisotropy” instead of “configuration asymmetry” to break the bandwidth bottleneck. The metamaterials with engineered anisotropy and dispersion are utilized to form a hetero‐anisotropic slab. For TM polarization, the slab performs as a multi‐mode interference coupler, while for TE polarization, the slab performs as two isolated waveguides. The fabricated PBS shows low loss <1 dB, high extinction ratio >20 dB, and a record working bandwidth >200 nm, with a footprint as small as 12.25 × 1.9 µm2.
Clonality and genetic profiles of drug‐resistant Mycobacterium tuberculosis in the Eastern Cape Province, South Africa
Authors: Bhembe Nolwazi L. , Nwodo Uchechukwu U. , Okoh Anthony I. , Obi Chikwelu L. , Mabinya Leonard V. , Green Ezekiel 
Published: February 2019

AbstractIn this study, we investigated the diversity of drug‐resistant Mycobacterium tuberculosis isolates from families who own cattle in the Eastern Cape Province of South Africa using spoligotyping and mycobacterial interspersed repetitive‐unit‐variable number tandem repeat (MIRU‐VNTR) typing. The Mycobacterium tuberculosis was investigated using MIRU‐VNTR and the Mycobacterium tuberculosis families were evaluated using spoligotyping. Spoligotyping grouped 91% of the isolates into seven clusters, while 9% of the deoxyribonucleic acid (DNA) from TB isolates were unclustered from a total of 154 DNA used. Previously described shared types were observed in 89.6% of the isolates, with the Beijing family, SIT1, the principal genotype in the province, while the families T, SIT53 and X1, SIT1329 were the least detected genotypes. MIRU‐VNTR grouped 81% of the isolates in 23 clusters while 19% were unclustered. A combination of the VNTR and spoligotyping grouped 79% of the isolates into 23 clusters with 21% unclustered. The low level of diversity and the clonal spread of drug‐resistant Mycobacterium tuberculosis isolates advocate that the spread of TB in this study may be instigated by the clonal spread of Beijing genotype. The results from this study provide vital information about the lack of TB control and distribution of Mycobacterium tuberculosis complex strain types in the Eastern Cape Province of South Africa.
ESBL‐production in Escherichia coli and Klebsiella pneumoniae isolates from Nigeria
Authors: Hertz Frederik B. , Jansåker Fillip , Okon Kenneth O. , Abdulmumin Ibrahim S. , Onah Joseph O. , Ladan Joshua , Knudsen Jenny D. 
Published: February 2019

AbstractThe worldwide increase in infections caused by extended‐spectrum beta‐lactamase‐ (ESBL) and AmpC‐producing Enterobacteriaceae (ESBL‐E) is a concern. Surveillance is extensive in Europe, North America, and Asia. Yet, there is no summarizing surveillance in Africa. This study aimed to perform a preliminary investigation on the prevalence of ESBL‐E in the northeastern part of Nigeria. However, of the 60 samples collected, we were able to culture 15 Escherichia coli and 7 Klebsiella spp. only. In the collection of clinical hospital samples, we found eight of 15 E. coli isolates to be ESBL (53%) and two out of seven Klebsiella spp. to be ESBL/AmpC (29%). Due to the limitations of this study, our findings cannot take a broad view on the prevalence of ESBL‐E, in Nigeria and other parts of Africa. Yet, to know which genes encode ESBL in Nigeria, and to know exact prevalence of every ESBL gene would be of importance.
1.6‐2.6 GHz continuous Class‐F power amplifier with gain and power‐added efficiency flatness enhancement by negative feedback structure
Authors: Qi Chongchong , Luo Yonglun , Feng Xuxu , Dong Chaoran 
Published: February 2019

AbstractThis article studies the feasibility of applying negative feedback structure in continuous Class‐F power amplifiers to improve the gain and efficiency flatness. The operation principle of the negative feedback structure under small and large signal input states is presented. The gain and efficiency are increased at high frequency part and decreased at low frequency by introducing the negative feedback structure, and the flatness is improved. Multiharmonic bilateral pull is used to obtain the optimum impedances, to reduce the interaction between source and load side, and the influence of parasitic parameters. A highly flatness amplifier with the negative feedback structure is designed operating at 1.6‐2.6 GHz by using a Cree GaN HEMT CGH40010H device. The measurement results show a gain flatness of 1.1 dB, and a power‐added efficiency flatness of 9%.
Low radar cross section microstrip antenna based on left‐handed material
Authors: Zhang Jia Kai , Xu Jia Chen , Ding Jun , Guo Chen Jiang 
Published: February 2019

AbstractThis article designs a hexagonal left‐handed material (LHM) and proposes a microstrip antenna with low radar cross‐section (RCS) based on this new LHM. The modified antenna RCS is significantly reduced without reducing radiation performance compared with two reference antennas. The scattering distribution shows the RCS reduction is attributable to the LHM. Antenna prototypes are fabricated and measured to verify the simulation. As a result, the modified antenna realized RCS reduction while maintaining radiation performance, with 19.5 dB maximum RCS reduction at 1.16 GHz, and the out‐of‐band RCS reduced due to the converged electromagnetic wave caused by the LHM.
Detection of potential microcalcification clusters using multivendor for‐presentation digital mammograms for short‐term breast cancer risk estimation
Authors: Alsheh Ali Maya , Eriksson Mikael , Czene Kamila , Hall Per , Humphreys Keith 
Published: February 2019

PurposeWe explore using the number of potential microcalcification clusters detected in for‐presentation mammographic images (the images which are typically accessible to large epidemiological studies) a marker of short‐term breast cancer risk.MethodsWe designed a three‐step algorithm for detecting potential microcalcification clusters in for‐presentation digital mammograms. We studied association with short‐term breast cancer risk using a nested case control design, with a mammography screening cohort as a source population. In total, 373 incident breast cancer cases (diagnosed at least 3 months after a negative screen at study entry) and 1466 matched controls were included in our study. Conditional logistic regression Wald tests were used to test for association with the presence of microcalcifications at study entry. We compared results of these analyses to those obtained using a Computer‐aided Diagnosis (CAD) software (VuComp) on corresponding for‐processing images (images which are used clinically, but typically not saved).ResultsWe found a moderate agreement between our measure of potential microcalcification clusters on for‐presentation images and a CAD measure on for‐processing images. Similar evidence of association with short‐term breast cancer risk was found (P = andP = , for our approach on for‐presentation images and for the CAD measure on for‐processing images, respectively) and interestingly both measures contributed independently to association with a short‐term risk (P = for the CAD measure, adjusted for our proposed method andP = for our proposed method, adjusted for the CAD measure).ConclusionMeaningful measurement of potential microcalcifications, in the context of short‐term breast cancer risk assessment, is feasible for for‐presentation images across a range of vendors. Our algorithm for for‐presentation images performs similarly to a CAD algorithm on for‐processing images, hence our algorithm can be a useful tool for research on microcalcifications and their role on breast cancer risk, based on large‐scale epidemiological studies with access to for‐presentation images.
Longitudinal fan‐beam computed tomography dataset for head‐and‐neck squamous cell carcinoma patients
Authors: Bejarano Tatiana , De Ornelas‐Couto Mariluz , Mihaylov Ivaylo B. 
Published: February 2019

PurposeTo describe in detail a dataset consisting of longitudinal fan‐beam computed tomography (CT) imaging to visualize anatomical changes in head‐and‐neck squamous cell carcinoma (HNSCC) patients throughout radiotherapy (RT) treatment course.Acquisition and validation methodsThis dataset consists of CT images from 31 HNSCC patients who underwent volumetric modulated arc therapy (VMAT). Patients had three CT scans acquired throughout the duration of the radiation treatment course. Pretreatment planning CT scans with a median of 13 days before treatment (range: 2–27), mid‐treatment CT at 22 days after start of treatment (range: 13–38), and post‐treatment CT 65 days after start of treatment (range: 35–192). Patients received RT treatment to a total dose of 58–70 Gy, using daily 2.0–2.20 Gy, fractions for 30–35 fractions. The fan‐beam CT images were acquired using a Siemens 16‐slice CT scanner head protocol with 120 kV and current of 400 mAs. A helical scan with 1 rotation per second was used with a slice thickness of 2 mm and table increment of 1.2 mm. In addition to the imaging data, contours of anatomical structures for RT, demographic, and outcome measurements are provided.Data format and usage notesThe dataset with DICOM files including images, RTSTRUCT files, and RTDOSE files can be found and publicly accessed in the Cancer Imaging Archive (TCIA, http://www.cancerimagingarchive.net/) as collection Head‐and‐neck squamous cell carcinoma patients with CT taken during pretreatment, mid‐treatment, and post‐treatment (HNSCC‐3DCT‐RT).DiscussionThis is the first dataset to date in TCIA which provides a collection of multiple CT imaging studies (pretreatment, mid‐treatment, and post‐treatment) throughout the treatment course. The dataset can serve a wide array of research projects including (but not limited to): quantitative imaging assessment, investigation on anatomical changes with treatment progress, dosimetry of target volumes and/or normal structures due to anatomical changes occurring during treatment, investigation of RT toxicity, and concurrent chemotherapy and RT effects on head‐and‐neck patients.
An evaluation of kefir grain size with magnetic resonance imaging to observe the fermentation of milk
Authors: Spicer Abi , Fairhurst David J. , Newton Michael I. , Morris Robert H. 
Published: February 2019

AbstractKefirian milk is a fermented beverage consumed worldwide. Originally produced in animal skins, it is now prepared both industrially and at home by adding symbiotic cultures of bacteria and yeast known as kefir grains to fresh milk. There is significant literature on the biological aspects of this process but little focus on the fermentation effects on the bulk milk as a function of the grain morphology. Changes in the Magnetic Resonance (MR) signal as measured using a whole body clinical magnetic resonance imaging scanner are found to be proportional to traditional gas measurements with correlation coefficients in excess of 0.95. Magnetic Resonance Imaging is then also used to determine the effect of grain size on the rate of fermentation of milk. It is found that larger grains result in signal intensity changes on the order of 0.03 a.u per hour, but by breaking the grains into pieces around 3mm, the reaction rate can be more than doubled to 0.07 a.u. per hour. It is thought that this shows promise as a method to improve the speed of production of kefirian milk and by arresting the process partway through fermentation, gives control over the properties of the end product.