bluuebunny/crossref_metadata_2025 huggingface dataset:
Nutrient control in water bodies: A systems approach
Authors: Shortle James S. , Mihelcic James R. , Zhang Qiong , Arabi Mazdak
Published: January 2020

Nutrient pollution is considered a wicked problem because of its many significant economic, social, and environmental impacts that are caused by multiple pollutants originating from a variety of sources and pathways that exist across different temporal and spatial scales. Further adding to the difficulty in managing nutrient pollution is that it is a global, rural, and urban problem. A systems approach can improve nutrient management by incorporating technological, environmental, and societal considerations. This approach can consider valuation of monetized and nonmonetized co‐benefits and the inherent consequences that make up a nutrient management program. In this introduction to a special collection of papers on nutrient pollution, we describe several systems frameworks that can be used to support nutrient management and evaluation of system performance as it relates to impacts, then highlight several attributes and barriers of nutrient management that point to the need for a systems framework, and conclude with thoughts on implementing systems approaches to nutrient management with effective community engagement and use of new technologies. This special collection presents results from a USEPA Science to Achieve Results (STAR) initiative to advance solutions to nutrient pollution through innovative and sustainable research and demonstration projects for nutrient management based on a systems approach. These studies evaluate several promising nutrient control technologies for stormwater or domestic wastewater, investigate the effects of agricultural conservation practices and stream restoration strategies on nutrient loads, and discuss several challenges and opportunities—social, policy, institutional, and financial considerations—that can accelerate adoption of reliable technologies to achieve system‐level outcomes.
Hydrological processes interconnecting the two largest watersheds of South America from seasonal to intra‐monthly time scales: A critical review
Authors: Zanin Paulo Rodrigo , Satyamurty Prakki
Published: January 2020

Many articles on the subjects of moisture transport, precipitation and surface hydrology of the two largest watersheds of South America, the Amazon and the La Plata basins, are stitched together to obtain an overview of the aspects related to the hydrological processes interconnecting them on time scales ranging from seasonal to intra‐monthly. In the mean, moisture from the tropical Atlantic Ocean is transported by the trade winds into the Amazon Basin. A good part of it precipitates over the Amazon Basin and the other part reaches the La Plata Basin by northerly winds east of the Andes. Besides the moisture transported from the Atlantic, there is evapotranspiration in the Amazon and La Plata basins. A part of the evapotranspiration of the Amazon Basin precipitates over the same basin, contributing with about 1/3 of annual precipitation this basin, and a part joins the aerial stream into the La Plata Basin, contributing with about 1/4 of its annual precipitation. Semi‐permanent and transient meteorological systems such as Inter‐Tropical Convergence Zone, South Atlantic Convergence Zone, Low‐Level Jet (LLJ) east of the Andes, Madden–Julian Oscillation, cold fronts and cyclones play an important role in the seasonal and intra‐seasonal variations of precipitation, evapotranspiration and river discharge. The hydrological memory in Amazonian soils and the LLJ constitute an inter‐seasonal coupling between the water balances of the two basins. All these aspects are succinctly described and discussed in this review article. Hypotheses for future research are formulated.
Formation and migration of α‐dicarbonyl compounds during storage and reheating of a sugary food simulation system
Authors: Zhuang Yuan , Dong Lu , Wang Jun‐ping , Wang Shu‐jun , Wang Shuo
Published: January 2020

BACKGROUND

The thermal processing of food results in the formation of α‐dicarbonyl compounds (α‐DCs) such as glyoxal (GO), methylglyoxal (MGO), 2,3‐butanedione (2,3‐BD), and 3‐deoxyglucosone (3‐DG), which are precursors of potentially harmful advanced glycation end products. Some of the α‐DCs found in food products might result from chemical deterioration reactions during storage and reheating. A range of sugary food simulation systems were stored at three different temperatures (4, 25, and 37 °C) and reheated using three different processing methods to investigate the formation and migration of α‐DCs.

RESULTS

During 20 days of storage, the concentration of α‐DCs declined, following which the concentration remained approximately constant. Methylglyoxal was the major α‐DC affected during storage, its relative content decreasing from 233.71 to 44.12 μg mL−1 in the glucose‐lysine system. The concentration of α‐DCs decreased with increasing temperature. Microwave reheating increased the formation of α‐DC compounds. The largest increases in 3‐DG concentrations were observed in the maltose‐lysine systems (24.94 to 35.74 μg mL−1). The concentration of α‐DCs only changed a little in response to reheating at 100 °C, but declined when reheated at 150 °C.

CONCLUSION

The concentration of α‐DCs following storage and reheating depends on the type of sugar, lysine content, temperature, and method of reheating. © 2020 Society of Chemical Industry
Prevalence of contamination by intestinal parasites in vegetables (Lactuca sativaL. andCoriandrum sativumL.) sold in markets in Belém, northern Brazil
Authors: Rodrigues Alessandro Cardoso , da Silva Melanie Dayane Castro , Pereira Regina Ângela Seixas , Pinto Laine Celestino
Published: January 2020

BACKGROUND

Previous studies have recorded a high prevalence of intestinal parasites in lettuce (Lactuca sativaL.) and coriander (Coriandrum sativumL.) destined for human consumption. This study determined the prevalence of contamination by intestinal parasites in these two plants sold in two street markets and two supermarkets in the city of Belém, northern Brazil.

RESULTS

A total of 200 plant samples were analyzed (100 of each species). The samples were collected randomly between August and October 2018, examined by the spontaneous sedimentation method with two washes, and stored for 24 h. The analysis found that 89% (89/100) of the lettuce samples and 86% (86/100) of the coriander samples were contaminated. Polyparasitism was more frequent in lettuce, but monoparasitism predominated in the coriander. A total of 226 intestinal parasites were found in the lettuce, with a predominance of non‐pathogenic parasites in the supermarket samples and more pathogenic parasites in the samples from street markets. In the coriander samples, 172 intestinal parasites were identified, with a predominance of pathogenic parasites in samples from both types of market. In the case of the protozoans, the most prevalent species wasEndolimax nana, followed byBlastocystis hominis, in both vegetables. In the helminths, hookworms predominated in the lettuce, andTrichuris trichiurain the coriander.

CONCLUSIONS

These results highlight the need for the monitoring of parasite contamination in vegetables destined for human consumption. Public health initiatives should include educational campaigns on the importance of disinfecting vegetables prior to consumption. © 2020 Society of Chemical Industry
Global desertification vulnerability to climate change and human activities
Authors: Huang Jianping , Zhang Guolong , Zhang Yanting , Guan Xiaodan , Wei Yun , Guo Ruixia
Published: January 2020

Desertification is the impoverishment of arid, semiarid, and some subhumid ecosystems. The assessment of global scale desertification vulnerability to climate change and human activity is important to help decision makers formulate the best strategies for land rehabilitation and combat global desertification in sensitive areas. There is no global desertification vulnerability map that considers both climate change and human activities. The main aim of this study was to construct a new index, the global desertification vulnerability index (GDVI), by combining climate change and human activity, provide another perspective on desertification vulnerability on a global scale, and project its future evolution. Using the probability density function of the GDVI, we classified desertification vulnerability into four classes: very high, high, medium, and low. The results of the analysis indicated that areas around deserts and barren land have a higher risk of desertification. Areas with a moderate, high, and very high desertification risk accounted for 13%, 7%, and 9% of the global area, respectively. Among the representative concentration pathways (RCPs), RCP8.5 projected that the area of moderate to very high desertification risk will increase by 23% by the end of this century. The areas where desertification risks are predicted to increase over time are mainly in Africa, North America, and the northern areas of China and India.
A tornado daily impacts simulator for the central and southern United States
Authors: Hatzis Joshua J. , Koch Jennifer , Brooks Harold E.
Published: January 2020

In an average year (1979–2016), the United States experiences nearly 1,100 tornadoes, which cause a total of 68 fatalities. Annual fatality rates have decreased since the peak in the 1920s, but there is a concern that they could start to rise again with increases in vulnerable populations and the impacts of climate change. It is possible to assess the risk of tornado fatalities using the historical record. However, the rarity of tornadoes and the short period of record may not capture the true risk. One way around this problem is to simulate thousands of years’ worth of tornadoes to obtain a broader picture of risk. Previous tornado risk models have distributed tornadoes randomly or used climatology to generate realistic tornado patterns on an annual (or longer) time scale. From an operational standpoint, it would be useful to have a model that distributes tornadoes on a daily time step to enable the forecasting of potential tornado impacts on a given day. The present study introduces one such model that distributes tornadoes using information about the favourability of the atmospheric environment for tornado development: The Tornado Daily Impacts Simulator (TorDIS). The paper demonstrates model utility through 1,000 year simulations over several metropolitan areas and with a comparison between modelled and observed impacts for several high‐impact tornado days. Forecasting potential tornado impacts on a daily time step could allow emergency managers to plan ahead for high‐risk days to prioritize their resources and save lives.
Possible mitochondrial dysfunction in a patient with deafness, dystonia, and cerebral hypomyelination (DDCH) due to BCAP31 Mutation
Authors: Shimizu Kenji , Oba Daiju , Nambu Ryusuke , Tanaka Manabu , Oguma Eiji , Murayama Kei , Ohtake Akira , Yoshiura Koh‐ichiro , Ohashi Hirofumi
Published: January 2020

Background

Deafness, dystonia, and cerebral hypomyelination (DDCH) is an X‐linked disorder due to hemizygous mutations of BCAP31.

Methods

We report an 8‐year‐old boy with DDCH who possibly accompanied mitochondrial dysfunction. Clinical evaluation, respiratory chain enzyme assay, and whole exome sequencing analysis were performed.

Results

Mitochondrial dysfunction was suspected by respiratory chain enzyme assay on his cultured skin fibroblasts which showed significantly decreased complex I enzyme activity. Whole exome sequencing analysis revealed a recurrent BCAP31 mutation (c.97C>T:p.Gln33*) which confirmed the diagnosis of DDCH for the patient.

Conclusion

We speculate that mitochondrial dysfunction may be a feature in patients with DDCH.
A case report of genetic prion disease with two different PRNP variants
Authors: Piazza Megan , Prior Thomas W. , Khalsa Prabhjot S. , Appleby Brian
Published: January 2020

Background

Prion diseases are a group of lethal neurodegenerative conditions that occur when the normal, cellular form of the prion protein (PrPC) is converted into an abnormal, scrapie, form of the protein (PrPSc). Disease may be caused by genetic, infectious, or sporadic etiologies. The genetic form of prion disease comprises~10%–15% of all cases. Prion disease is typically inherited in an autosomal dominant manner. The low incidence of disease makes it highly unlikely that a patient would have two different pathogenic variants. However, we recently identified a case in which the patient did have two pathogenic PRNP variants and presented with an atypical phenotype.

Methods

The patient was evaluated at the Washington Hospital Healthcare System in Fremont, CA. The clinical information for this case report was obtained retrospectively. Variants in the PRNP were identified by polymerase chain reaction (PCR) amplification of exon two of the gene followed by bi‐directional sequence analysis. To determine the phase of the identified variants, a restriction enzyme digestion was utilized, followed by sequence analysis of the products. Cerebral spinal fluid (CSF) was analyzed for surrogate markers of prion disease, 14–3–3 and Tau proteins. CSF real‐time quaking‐induced conversion (RT‐QuIC) assays were also performed.

Results

The patient was a compound heterozygote for the well‐characterized c.628G>A (p.Val210Ile) variant and the rare octapeptide deletion of two repeats [c.202_249del48 (p.P68_Q83del)]. Clinically, the patient presented with an early onset demyelinating peripheral neuropathy, followed by later onset cognitive symptoms.

Conclusion

This presentation is reminiscent of prion protein knockout mice whose predominate symptom, due to complete loss of PrP, was late‐onset peripheral neuropathy. To our knowledge this is the first case reported of a patient with prion disease who had two different pathogenic variants in PRNP.
Probiotics Prevent Dysbiosis and the Rise in Blood Pressure in Genetic Hypertension: Role of Short‐Chain Fatty Acids
Authors: Robles‐Vera Iñaki , Toral Marta , de la Visitación Néstor , Sánchez Manuel , Gómez‐Guzmán Manuel , Romero Miguel , Yang Tao , Izquierdo‐Garcia José L. , Jiménez Rosario , Ruiz‐Cabello Jesús , Guerra‐Hernández Eduardo , Raizada Mohan K. , Pérez‐Vizcaíno Francisco , Duarte Juan
Published: January 2020

Scope

The objective of this study is to determine the cardiovascular effects of the probiotics Bifidobacterium breve CECT7263 (BFM) and Lactobacillus fermentum CECT5716 (LC40), and the short chain fatty acids butyrate, and acetate in spontaneously hypertensive rats (SHR).

Methods and results

Ten five‐week old Wistar Kyoto rats (WKY) and fifty aged‐matched SHR are randomly distributed into six groups: control WKY, control SHR, treated SHR‐LC40, treated SHR‐BMF, treated SHR‐butyrate, and treated SHR‐acetate. Chronic treatments with LC40 or BFM increase butyrate‐producing bacteria and prevent the blood pressure increase in SHR. Oral treatment with butyrate or acetate also prevents the increase in both blood pressure and Firmicutes/Bacteroidetes (F/B) ratio. All treatments restore the Th17/Treg balance in mesenteric lymph nodes, normalized endotoxemia, and prevent the impairment of endothelium‐dependent relaxation to acetylcholine, as a result of reduced NADPH oxidase‐driven reactive oxygen species production. These protective effects might be mediated by both the reduction in vascular lipopolysaccharide (LPS)/toll‐like receptor 4 (TLR4) pathway and the increase in Treg infiltration in the vasculature.

Conclusion

The probiotics LC40 and BFM prevent dysbiosis and the development of endothelial dysfunction and high blood pressure in genetic hypertension. These effects seem to be related to endotoxemia reduction and to increase Treg accumulation in the vasculature.
Lactobacillus Protects Against S. Typhimurium–Induced Intestinal Inflammation by Determining the Fate of Epithelial Proliferation and Differentiation
Authors: Lu Xiaoxi , Xie Shuang , Ye Lulu , Zhu Linda , Yu Qinghua
Published: January 2020

Scope

The influence of the intestinal microbiota, such as Lactobacillus, on the intestinal mucosa, particularly intestinal stem cells, remains incompletely understood. In this study, mice and intestinal organoids are used to explore the regulatory effect of Lactobacillus on the proliferation and differentiation of intestinal epithelial cells.

Methods and results

This study demonstrates that S. typhimurium causes intestinal epithelial damage and affected growth of intestinal organoids. S. typhimurium also colonizes the intestine and then causes pathological changes to the intestinal epithelium, intestinal inflammation, and even death. However, L. acidophilus alleviates damage to intestinal organoids, increases the survival ratio of mice infected with S. typhimurium, and reduces tumor necrosis factor‐α (TNF‐α) secretion. Moreover, L. acidophilus affects the differentiation of epithelial cells through inhibition of the excessive expansion of goblet cells and Paneth cells induced by S. typhimurium to avoid over‐exhaustion. Finally, it is also demonstrated that L. acidophilus ameliorates overactivation of Wnt/β‐catenin pathway by Salmonella, depending on the contact with toll‐like receptor 2 (TLR2), to affect the proliferation of the intestinal epithelium.

Conclusions

This study demonstrates that L. acidophilus protects the intestinal mucosa against S. typhimurium infection through not only the inhibition of pathogen invasion but also determination of the fate of the intestinal epithelium.
Tuna Bone Powder Alleviates Glucocorticoid‐Induced Osteoporosis via Coregulation of the NF‐κB and Wnt/β‐Catenin Signaling Pathways and Modulation of Gut Microbiota Composition and Metabolism
Authors: Li Jingjing , Yang Mingyuan , Lu Chenyang , Han Jiaojiao , Tang Shasha , Zhou Jun , Li Ye , Ming Tinghong , Wang Zaijie Jim , Su Xiurong
Published: January 2020

Scope

The effects and mechanism of tuna bone powder (TBP) on glucocorticoid‐induced osteoporosis (GIOP) alleviation in terms of signaling pathway coregulation and gut microbiota modulation are investigated.

Methods and results

The powder size distribution and composition of TBP are measured. The GIOP female mice induced by dexamethasone intramuscular injection are used to examine the anti‐osteoporosis effects of TBP in a 10 week experiment, and improved bone mineral density and bone microarchitecture are observed via micro‐CT. In addition, qRT‐PCR results show that the NF‐κB pathway is inhibited to reduce bone resorption, whereas the Wnt/β‐catenin pathway is activated to enhance bone formation after treatment. Moreover, TBP treatments suppress the release of pro‐inflammatory cytokines, repair dysfunction of the intestinal epithelial barrier, and prevent aggravated systemic inflammation in mRNA levels. Additionally, 16S rRNA gene sequencing indicate that TBP treatments enhance the abundance of anti‐inflammatory bacteria and short‐chain fatty acid (SCFA) producers, which is consistent with increased SCFA contents in feces measured via GC–MS.

Conclusion

These data show that TBP ameliorates GIOP in mice through four aspects, including coregulating signaling pathways, blocking proinflammatory cytokines, repairing the intestinal epithelial barrier, and modulating gut microbiota. Therefore, TBP may be a potential prebiotic agent to alleviate osteoporosis in humans.
Fully automated segmentation of left ventricular scar from 3D late gadolinium enhancement magnetic resonance imaging using a cascaded multi‐planar U‐Net (CMPU‐Net)
Authors: Zabihollahy Fatemeh , Rajchl Martin , White James A. , Ukwatta Eranga
Published: January 2020

Purpose

Three‐dimensional (3D) late gadolinium enhancement magnetic resonance (LGE‐MR) imaging enables the quantification of myocardial scar at high resolution with unprecedented volumetric visualization. Automated segmentation of myocardial scar is critical for the potential clinical translation of this technique given the number of tomographic images acquired.

Methods

In this paper, we describe the development of cascaded multi‐planar U‐Net (CMPU‐Net) to efficiently segment the boundary of the left ventricle (LV) myocardium and scar from 3D LGE‐MR images. In this approach, two subnets, each containing three U‐Nets, were cascaded to first segment the LV myocardium and then segment the scar within the presegmented LV myocardium. The U‐Nets were trained separately using two‐dimensional (2D) slices extracted from axial, sagittal, and coronal slices of 3D LGE‐MR images. We used 3D LGE‐MR images from 34 subjects with chronic ischemic cardiomyopathy. The U‐Nets were trained using 8430 slices, extracted in three orthogonal directions from 18 images. In the testing phase, the outputs of U‐Nets of each subnet were combined using the majority voting system for final label prediction of each voxel in the image. The developed method was tested for accuracy by comparing its results to manual segmentations of LV myocardium and LV scar from 7250 slices extracted from 16 3D LGE‐MR images. Our method was also compared to numerous alternative methods based on machine learning, energy minimization, and intensity‐thresholds.

Results

Our algorithm reported a mean dice similarity coefficient (DSC), absolute volume difference (AVD), and Hausdorff distance (HD) of 85.14% ± 3.36%, 43.72 ± 27.18 cm3, and 19.21 ± 4.74 mm for determining the boundaries of LV myocardium from LGE‐MR images. Our method also yielded a mean DSC, AVD, and HD of 88.61% ± 2.54%, 9.33 ± 7.24 cm3, and 17.04 ± 9.93 mm for LV scar segmentation on the unobserved test dataset. Our method significantly outperformed the alternative techniques in segmentation accuracy (P < 0.05).

Conclusions

The CMPU‐Net method provided fully automated segmentation of LV scar from 3D LGE‐MR images and outperformed the alternative techniques.
Spatially guided nonlocal mean approach for denoising of PET images
Authors: Arabi Hossein , Zaidi Habib
Published: January 2020

Purpose

Nonlocal mean (NLM) filtering proved to be an effective tool for noise reduction in natural and medical imaging. The technique relies on existing redundant information in the input image to discriminate the genuine signal from noise. However, due to the prohibitively long computation time, the search for finding similar information is confined by a predefined search window, which may hamper the performance of this filter. In this work, a spatially guided non local mean (SG‐NLM) approach was proposed to overcome this issue. The proposed method was evaluated on whole‐body positron emission tomography images presenting with high noise levels, which adversely affect lesion detectability and quantitative accuracy.

Methods

In the SG‐NLM method, as opposed to the conventional NLM method, where a predefined search window is defined to confine exhaustive search for finding similar patterns, the information about similar patterns is extracted from the clustered version (created based on signal intensity levels) of the input image as well as information about prominent edges. The performance of the SG‐NLM was evaluated against post‐reconstruction NLM, Gaussian, bilateral and BayesShrink Wavelet denoising approaches. A digital phantom containing three small inserts mimicking lesions in the lung, experimental study using the Jaszczak phantom and whole‐body PET/CT clinical studies were utilized to assess the performance of abovementioned denoising approaches.

Results

The SG‐NLM method led to a signal‐to‐noise (SNR) increase from 21.3 (unfiltered PET image) to 30.1 in computer simulations of small lesions while the NLM mean filer resulted in an SNR of 29.4 (P < 0.05). The experimental Jaszczak phantom study demonstrated that the contrast‐to‐noise ratio (CNR) increased from 11.3 when using the Gaussian filter to 18.6 and 19.5 when using NLM and SG‐NLM filters (P < 0.05), respectively. The superior performance of the SG‐NLM approach was confirmed by clinical studies where the bias in malignant lesions decreased to −2.3 ± 1.1% compared to −11.7 ± 2.4 and −2.9 ± 1.1 achieved using the Gaussian and NLM methods (P < 0.05), respectively.

Conclusions

The proposed SG‐NLM achieves promising compromise between noise reduction and signal preservation compared to the conventional NLM method. The superior performance of the SG‐NLM method was accomplished without adding extra burden to the computational complexity of the conventional NLM filter, which makes it attractive for denoising PET images.
Experimental measurement of ionization chamber angular response and associated magnetic field correction factors in MR‐linac
Authors: Iakovenko Viktor , Keller Brian , Sahgal Arjun , Sarfehnia Arman
Published: January 2020

Purpose

To measure ionization chamber dose response as a function of the angle between magnetic field direction and ionization chamber orientation in magnetic resonance‐guided radiation therapy (MRgRT) system, and to evaluate angular dependence of magnetic field correction factor for reference dosimetry.

Methods

Measurements were performed on an Elekta MR‐linac that integrates a 1.5‐T Philips MRI and a 7‐MV FFF photon beam accelerator. The response of four reference class chambers (Exradin‐A19, A1SL, IBA FC65‐G, and CC13, paired with a PTW UE electrometer) was studied. An in‐house built MR‐compatible water tank and an accompanying cylindrical insert that allowed chamber rotation around the cylinder's axis was used. The EPID onboard imaging was used to center chamber at the MR‐linac isocenter (143.5 cm, SAD), as well as to verify position at each datapoint.

Results

A clear angular dependence of dose response for all chambers has been measured. The most significant effect of magnetic field on relative chamber response in the presence of magnetic field was observed in the orientation when chamber axis is perpendicular to the direction of magnetic field with the tip pointing in the same direction as Lorentz force. This effect is more pronounced for larger volume chambers; the maximum relative variation in the chamber response (between the setup described above and the one where chamber and magnetic field are parallel) is a 5.3% and 4.6% increase for A19 and FC65‐G, respectively, and only 2.0% and 1.9% for smaller volume A1SL and CC13 chamber, respectively. We measured the absolute magnitude of the magnetic field correction factor for the Exradin‐A19, A1SL, IBA FC65‐G, and CC13 to be 0.938 ± 1.13%, 0.968 ± 0.99%, 0.950 ± 1.13%, and 0.975 ± 1.13%, respectively. The values are for perpendicular orientation of the chamber relative to magnetic field and parallel to the Lorentz force.

Conclusions

Experimental measurements carried out in this study have verified the optimal orientation of ionization chamber in terms of minimizing effect of magnetic field on the chamber dose response. This study provides a detailed high‐resolution measurement of absolute values for four reference class chambers as a function of the angle between ionization chamber’s central axis and the direction of strong magnetic field over a full 360° rotation. The experimental results of this study can further be used for optimization of the actual sensitive volume of the chamber (and analysis of dead volume) in future Monte Carlo chamber simulations in the presence of strong magnetic fields. In addition, it will provide some necessary data for future reference dosimetry protocols for MR‐linac.
A fluence modulation and scatter shielding apparatus for dedicated breast CT: Theory of operation
Authors: Ghazi Peymon
Published: January 2020

Purpose

To introduce an auxiliary apparatus of fluence modulation and scatter shielding for dedicated breast computed tomography (bCT) and the corresponding patient‐specific method of image acquisition.

Methods

The apparatus is composed of two assemblies, referred to herein as the “Dynamic Fluence Gate” (FG) and “Scatter Shield” (SS), that work in synchrony to form a narrow beam sweeping the entire fan angle coverage of the imaging system during a projection. The apparatus, as a whole, is referred to as FG‐SS. FG and SS are pre‐patient and post‐patient units, respectively. Each is composed of a rotating drum, on top of which are installed two sheets of high x‐ray attenuating material, a sensory system, and the constituent robotics. The sheets of each unit are positioned such that an opening — a window Fluence Modulation and Scatter Shielding is formed between them. The rotations of the drums and positioning of the sheets are synchronized and adjusted such that a line of sight is created between the source, FG window, the breast, and the SS window. With line of sight achieved, the narrow beam transitions from the source to the detector. The fluence of the narrow beam during a projection depends on the size, shape, and positioning of the breast. The FG‐SS method of imaging is discussed mathematically and demonstrated using computer simulations. A series of Monte Carlo simulations are conducted to evaluate the performance of the system as relates to its impact on the imager’s dynamic range, dose distribution to the breast, noise inhomogeneity in reconstructed images, and scatter buildup in projections within small, medium, and large breasts composed of homogeneous medium breast tissue.

Results

Implementation of FG‐SS results in near scatter‐free projections, reduction in both dose and the required dynamic range of the imager, and equalization of the quantum noise distribution in the reconstructed image. Using the disclosed design, the dynamic range was reduced by factors ranging from 1.6 to 5.5 across the range of breast sizes studied. A reduction in the acquisition of the scattered rays, varying between the factors of 6.1 (in the small breast) and 9.8 (in that large breast) was achieved and consequently, shading artifacts were suppressed. Noise in the CT image was equalized by reducing the overall spatial variation from 29% to <5% in small breast and from 45% to 14% in the large breast. An overall reduction in deposited dose to the breast was achieved — between 26% and 39% depending on the breast size.

Conclusions

Utilization of the FG‐SS apparatus and technique was demonstrated via simulations to result in: significant reductions in dose to the breast, reductions in scatter uptake in projections, reduced required dynamic range of the imager, and homogenizing of quantum noise throughout the reconstructed image.
Influence of thermal oxidation and maleinized liquid polybutadiene on dynamic and static performance of short aramid fiber‐reinforced carbon black‐ethylene propylene diene monomer composites
Authors: Yang Bo , Li Peng , Luo Zhu , Zhong Jincheng , Yin Lianpeng
Published: January 2020

Short aramid fiber (AF)‐reinforced rubber composites (SFRRs) possess better mechanical performance than carbon black‐filled rubber in many respects. However, the performance of an SFRR depends on interfacial adhesion to a large extent. In this article, AF was treated by thermal oxidation and then used to prepare AF‐reinforced carbon black‐ethylene propylene diene monomer (CB‐EPDM) composites in the presence of maleinized liquid polybutadiene rubber as the compatibilizer. The interfacial adhesion between the AF and matrix was evaluated by means of the relative debonding energy (RDE), and the corresponding dynamic and static performance was studied. The interfacial adhesion could be improved by a combination of fiber surface treatment and rubber compatibility, and the RDE was increased. Compared with those of the unmodified AF‐reinforced CB‐EPDM, the tensile moduli at 100% and 300% elongation and the tear strength increased by 27.4%, 16.7%, and 22.9%, respectively, and the stress‐controlled fatigue life of the notched sample increased by 140%. The results showed that the RDE decreased gradually with increasing average deformation after strain‐controlled fatigue for 30 000 cycles, and the RDE remained at a higher level in the AF‐reinforced CB‐EPDM when better interfacial adhesion was formed.
Metabolite variations and antioxidant activity of Muntingia calabura leaves in response to different drying methods and ethanol ratios elucidated by NMR‐based metabolomics
Authors: Zolkeflee Nur Khaleeda Zulaikha , Isamail Nor Amira , Maulidiani Maulidiani , Abdul Hamid Nur Ashikin , Ramli Nurul Shazini , Azlan Azrina , Abas Faridah
Published: January 2020

Introduction

Muntingia calabura from the Muntingiaceae family has been documented for several medicinal uses. The combinations of drying treatment and extracting solvents for a plant species need to be determined and optimised to ensure that the extracts contain adequate amounts of the bioactive metabolites.

Objective

Evaluate the metabolite variations and antioxidant activity among M. calabura leaves subjected to different drying methods and extracted with different ethanol ratios using proton nuclear magnetic resonance (1H‐NMR)‐based metabolomics.

Methodology

The antioxidant activity of M. calabura leaves dried with three different drying methods and extracted with three different ethanol ratios was determined by using 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) and nitric oxide (NO) scavenging assays. The metabolites variation among the extracts and correlation with antioxidant activity were analysed by 1H‐NMR‐based metabolomics.

Results

Muntingia calabura leaves extracted with 50% and 100% ethanol from air‐drying and freeze‐drying methods had the highest total phenolic content and the lowest IC50 value for the DPPH scavenging activity. Meanwhile, oven‐dried leaves extracted with 100% ethanol had the lowest IC50 value for the NO scavenging activity. A total of 43 metabolites, including sugars, organic acids, amino acids, phytosterols, phenolics and terpene glycoside were tentatively identified. A noticeable discrimination was observed in the different ethanol ratios by the principal component analysis. The partial least‐squares analysis suggested that 32 compounds out of 43 compounds identified were the contributors to the bioactivities.

Conclusion

The results established set the preliminary steps towards developing this plant into a high value product for phytomedicinal preparations.
System optimisation quantitative model of on‐line NIR: a case of Glycyrrhiza uralensis Fisch extraction process
Authors: Zeng Jingqi , Zhou Zheng , Liao Yuan , Ma Lijuan , Huang Xingguo , Zhang Jing , Lin Ling , Zhu Jinyuan , Lei Leting , Cao Junjie , Shen Haoran , Zheng Yanfei , Wu Zhisheng
Published: January 2020

Introduction

The on‐line analysis of active pharmaceutical ingredients (APIs) during the extraction process in herbal medicine is a challenge. Establishing a reliable and robust model is a critical procedure for the industrial application of on‐line near‐infrared (NIR) technology.

Objective

To evaluate the advantages of on‐line NIR model development using system optimisation strategy, Glycyrrhiza uralensis Fisch was used as a case. The content of liquiritin and glycyrrhizic acid was monitored during pilot scale extraction process of Glycyrrhiza uralensis Fisch in three batches.

Methods

High‐performance liquid chromatography (HPLC) was used as reference method for content determination of liquiritin and glycyrrhizic acid. The quantitative models of on‐line NIR were developed by system optimisation of processing trajectory. For comparison, the models were simultaneously developed by stepwise optimisation. Moreover, the modelling parameters obtained through system optimisation and stepwise optimisation were reused in three batches. Root mean square error of prediction (RMSEP) and residual predictive deviation (RPD) were used to assess the model quality.

Results

The average values of RMSEP and RPD of systematic model for liquiritin in three batches were 0.0361, 4.1525 (first batch), 0.0348, 4.7286 (second batch) and 0.0311, 4.9686 (third batch), respectively. In addition, the modelling parameters of systematic model for glycyrrhizic acid in three batches were same, and the average values of RMSEP and RPD were 0.0665 and 5.2751, respectively. The predictive performance and robustness of systematic models for the three batches were better than the comparison models.

Conclusion

The work demonstrated that system optimisation quantitative model of on‐line NIR could be used to determine the contents of liquiritin and glycyrrhizic acid during Glycyrrhiza uralensis Fisch extraction process.
Aspirin for prevention of preeclampsia and fetal growth restriction
Authors: Loussert Lola , Vidal Fabien , Parant Olivier , Hamdi Safouane M. , Vayssiere Christophe , Guerby Paul
Published: January 2020

For the past decades, growing attention has been given to aspirin use during pregnancy. It favors placentation by its proangiogenic, antithrombotic, and anti‐inflammatory effects. Therefore, low doses of aspirin are prescribed in the prevention of placenta‐mediated complications, mainly preeclampsia and fetal growth restriction. However, questions regarding its clinical application are still debated. Aspirin is effective in preventing preeclampsia in a high‐risk population. Most guidelines recommend that risk stratification should rely on medical history. Nevertheless, screening performances dramatically improve if biochemical and biophysical markers are included. Concerning the appropriate timing and dose, latest studies suggest aspirin should be started before 16 weeks of pregnancy and at a daily dose of 100 mg or more. Further studies are needed to improve the identification of patients likely to benefit from prophylactic aspirin. Besides, the role of aspirin in the prevention of fetal growth restriction is still questioned.
Prenatal diagnosis of birth defects and termination of pregnancy in Hunan Province, China
Authors: Xie Donghua , Liang Changbiao , Xiang Yueyun , Wang Aihua , Xiong Lili , Kong Fanjuan , Li Haoxian , Liu Zhiyu , Wang Hua
Published: January 2020

Objective

The aim of this study was to analyse the characteristics of the prenatal diagnosis (PD) of birth defects (BDs) and termination of pregnancy (TOP) for fetal anomalies and to suggest perinatal management.

Methods

BD surveillance data were collected from 52 registered hospitals in Hunan between 2015 and 2018. The PD and TOP rates of BDs were calculated to examine the associations between infant sex, maternal age, and region.

Results

From 2015 to 2018, a total of 18 931 fetuses with BDs were identified, of which 10 299 fetuses (54.4%) were diagnosed prenatally and 9343 pregnancies (90.7% among PDs and 49.3% among BDs) were terminated. The mean gestational age at diagnosis for fetuses with BDs was 25.1 ± 5.9 weeks and showed a downward trend over the study period. The average PD rate of the BDs was higher in rural areas than in urban areas (58.1% vs 50.3%), higher for female than male fetuses (57.25% vs 48.92%), and higher for mothers older than age 35 than for those younger (58.62% vs 53.69%). The average TOP rate of fetuses with BDs in rural areas was higher than that in urban areas (91.99% vs 89.12%) and decreased with increasing maternal age ( = 7.926, P = .005). The five BDs with the highest PD rates were conjoined twins (100%), anencephaly (97.87%), congenital hydrocephalus (97.66%), chromosomal malformation (96.07%), and encephalocele (95.54%). The five BDs with the highest TOP rates among the PDs were conjoined twins (100%), exstrophy of the urinary bladder (100%), chromosomal malformation (98.09%), encephalocele (98%), and anencephaly (97.28%).

Conclusions

More than half of BDs were diagnosed prenatally, with the majority diagnosed at less than 28 gestational weeks. The TOP rates following PD in Hunan Province were high, especially for rural and younger mothers. The findings suggest a need for high‐quality, targeted counselling following PD.
Prenatal ultrasound findings of holoprosencephaly spectrum: Unusual associations
Authors: El‐Dessouky Sara H. , Aboulghar Mona M. , Gaafar Hassan M. , Abdella Rana M. , Sharaf Marwa F. , Ateya Mohamed I. , Elarab Ahmed Ezz , Zidan Walaa H. , Helal Rania M. , Aboelsaud Samah M. , Eid Maha M. , Abdel‐Salam Ghada M.H.
Published: January 2020

Objective

The objective of this study is to evaluate the prenatal diagnosis, postnatal characteristics, and the spectrum of associated findings in fetuses with holoprosencephaly (HPE).

Methods

Fetal neurosonograms, postnatal assessment, and chromosomal analysis were performed in a cohort of 25 fetuses with HPE.

Results

The prevalence of HPE in high‐risk pregnancies was 4.4:10 000. The alobar subtype was the most frequently encountered, with 17 cases (68%). Interestingly, among them, four cases (16%) presented with the rare agnathia‐otocephaly complex. Chromosomal abnormalities were detected in 11 cases (44%), the most frequent being trisomy 13 in seven cases (five alobar, one semilobar, and one lobar HPE), followed by trisomy 18 in two cases with semilobar HPE. One case of alobar HPE had 45, XX, t(18;22) (q10;q10), −18p karyotyping, and one case of semilobar HPE was associated with triploidy. Facial malformations in HPE spectrum ranged from cyclopia, proboscis, and arrhinia that were associated with the alobar subtype to hypotelorism and median cleft that were frequent among the semilobar and lobar subtypes. Associated neural tube defects were identified in 12% of cases.

Conclusion

Our study illustrates the clinical and genetic heterogeneity of HPE and describes different chromosomal abnormalities associated with HPE.
Graphite fluoride and fluorographene as a new class of solid lubricant additives for high‐performance polyamide 66 composites with excellent mechanical and tribological properties
Authors: Sun Haoyang , Li Tao , Lei Fan , Yang Meng , Li Dandan , Huang Xianhang , Sun Dazhi
Published: January 2020

Fluorographene (FG) with layer numbers of 3–4 was successfully prepared through facile microwave‐assisted liquid phase exfoliation of raw graphite fluoride (GrF). The raw GrF and the as‐prepared FG were then directly incorporated into polyamide 66 (PA66) by melt processing without using any surfactants. Microstructural, mechanical and tribological properties of the prepared PA66 composites were investigated. Various characterization results showed that both GrF and FG, as novel solid lubricants, can effectively improve the mechanical and anti‐wear performances of the PA66 matrix. It was also found that FG is better at improving mechanical properties and reducing the friction of PA66 than GrF at low concentrations owing to the large surface–volume ratio. The addition of 0.5 wt% FG into PA66 exhibits a ca 13% increase in tensile modulus, ca 5% increase in tensile strength, ca 18% reduction in coefficient of friction (COF) and ca 43% reduction in wear rate. However, at relatively high concentrations, such as 1.0 wt%, GrF shows a better reinforcement effect than FG owing to a uniform dispersion of GrF in the PA66 matrix. The addition of 1.0 wt% GrF into PA66 exhibits a ca 18% increase in tensile modulus, ca 5% increase in tensile strength, ca 37% reduction in COF and ca 46% reduction in wear rate. Wear tests also show that the excellent wear resistance of the PA66 composites is due to the improved mechanical properties and the lubrication of GrF and FG between the worn surfaces. Our current work demonstrates the tremendous potentials of fluorinated carbon materials for enhancing mechanical and anti‐wear properties of polymeric materials. © 2020 Society of Chemical Industry
One‐step formation of polyurea gel as a multifunctional approach for biological and environmental applications
Authors: Bonattini Vinicius H , Paula Lucas AL , de Jesus Natana AM , Tavares Denise C , Nicolella Heloiza D , Magalhães Lizandra G , Molina Eduardo F
Published: January 2020

This work presents a facile one‐pot fabrication of polyurea (PU) organogels based on polyetheramine (PEO, Jeffamine ED‐2003) and a crosslinker hexamethylene diisocyanate trimer (HDI) which were subsequently used as a drug carrier to incorporate a curcumin hydrophobic molecule in aqueous conditions and for removal of an anionic pollutant in water. PU can be obtained in different shapes with easy control of film thickness with high transparency, flexibility and homogeneous dispersion of curcumin in the matrix. Due to the hydrophilic nature of PEO a high swelling degree was demonstrated by the PU gel. The phase separated domains and the temperature's influence on the system's structural order/disorder were examined by small‐angle X‐ray scattering, showing a more PU ordered system (interface between hard and soft segments) after decreasing the temperature to −90 °C. The presence of curcumin in the structure of PU was confirmed by Fourier transform infrared, photoluminescence and release studies. A highly efficient removal of Congo red dye from aqueous solution using PU as adsorbent was observed. Moreover, the effect of unloaded and curcumin‐loaded PU gels was evaluated onSchistosoma mansoniadult worms. Detailedin vitrocell viability experiments showed the biocompatibility of loaded and unloaded PU gels. The easy processability of the multifunctional PU shows that it has promising applications as transdermal and soft tissue implantable delivery devices for a large number of poorly water‐soluble drugs and as an efficient adsorbent for removal of organic dyes; it can also be used in the future in dermatological treatments against malignant melanoma. © 2020 Society of Chemical Industry
Visual‐based autonomous field of view control of laparoscope with safety‐RCM constraints for semi‐autonomous surgery
Authors: Sun Yanwen , Pan Bo , Fu Yili , Niu Guojun
Published: January 2020

Purpose

The surgeon is not timely in direct control of his field of view. Autonomous laparoscope control can provide appropriate surgical field of view and facilitate the intelligent level of surgical robot system.

Methods

This study explores an autonomous laparoscope control framework for semiautonomous surgery. We propose a novel concept that integrates two forms of Remote Center of Motion (RCM) constraint. We also propose a novel safety‐RCM model to cope with the collision condition. We modify the image Jacobian matrix to realize RCM constraint. The two models constitute a dual‐RCM constraint for robot laparoscope arm. We perform validation of the algorithm with two experiments.

Results

The experimental results show that the RCM position error can be reduced with the dual‐RCM constraint. Owing to safety‐RCM model, autonomous surgical field of view control could still be realized in case of collision.

Conclusion

The autonomous laparoscope control could be realized with safety‐RCM and dual‐RCM algorithms.