bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of filamentous phages in environment: A tectonic shift in the science and practice of ecorestoration
Authors: Sharma Radhey Shyam , Karmakar Swagata , Kumar Pankaj , Mishra Vandana
Published: January 2019

Theories in soil biology, such as plant–microbe interactions and microbial cooperation and antagonism, have guided the practice of ecological restoration (ecorestoration). Below‐ground biodiversity (bacteria, fungi, invertebrates, etc.) influences the development of above‐ground biodiversity (vegetation structure). The role of rhizosphere bacteria in plant growth has been largely investigated but the role of phages (bacterial viruses) has received a little attention. Below the ground, phages govern the ecology and evolution of microbial communities by affecting genetic diversity, host fitness, population dynamics, community composition, and nutrient cycling. However, few restoration efforts take into account the interactions between bacteria and phages. Unlike other phages, filamentous phages are highly specific, nonlethal, and influence host fitness in several ways, which make them useful as target bacterial inocula. Also, the ease with which filamentous phages can be genetically manipulated to express a desired peptide to track and control pathogens and contaminants makes them useful in biosensing. Based on ecology and biology of filamentous phages, we developed a hypothesis on the application of phages in environment to derive benefits at different levels of biological organization ranging from individual bacteria to ecosystem for ecorestoration. We examined the potential applications of filamentous phages in improving bacterial inocula to restore vegetation and to monitor changes in habitat during ecorestoration and, based on our results, recommend a reorientation of the existing framework of using microbial inocula for such restoration and monitoring. Because bacterial inocula and biomonitoring tools based on filamentous phages are likely to prove useful in developing cost‐effective methods of restoring vegetation, we propose that filamentous phages be incorporated into nature‐based restoration efforts and that the tripartite relationship between phages, bacteria, and plants be explored further. Possible impacts of filamentous phages on native microflora are discussed and future areas of research are suggested to preclude any potential risks associated with such an approach.
Studying the microbiota of bats: Accuracy of direct and indirect samplings
Authors: Dietrich Muriel , Markotter Wanda
Published: January 2019

Given the recurrent bat‐associated disease outbreaks in humans and recent advances in metagenomics sequencing, the microbiota of bats is increasingly being studied. However, obtaining biological samples directly from wild individuals may represent a challenge, and thus, indirect passive sampling (without capturing bats) is sometimes used as an alternative. Currently, it is not known whether the bacterial community assessed using this approach provides an accurate representation of the bat microbiota. This study was designed to compare the use of direct sampling (based on bat capture and handling) and indirect sampling (collection of bat's excretions under bat colonies) in assessing bacterial communities in bats. Using high‐throughput 16S rRNA sequencing of urine and feces samples from Rousettus aegyptiacus, a cave‐dwelling fruit bat species, we found evidence of niche specialization among different excreta samples, independent of the sampling approach. However, sampling approach influenced both the alpha‐ and beta‐diversity of urinary and fecal microbiotas. In particular, increased alpha‐diversity and more overlapping composition between urine and feces samples was seen when direct sampling was used, suggesting that cross‐contamination may occur when collecting samples directly from bats in hand. In contrast, results from indirect sampling in the cave may be biased by environmental contamination. Our methodological comparison suggested some influence of the sampling approach on the bat‐associated microbiota, but both approaches were able to capture differences among excreta samples. Assessment of these techniques opens an avenue to use more indirect sampling, in order to explore microbial community dynamics in bats.
Limited effects of early snowmelt on plants, decomposers, and soil nutrients in Arctic tundra soils
Authors: Darrouzet‐Nardi Anthony , Steltzer Heidi , Sullivan Patrick F. , Segal Aliza , Koltz Amanda M. , Livensperger Carolyn , Schimel Joshua P. , Weintraub Michael N.
Published: January 2019

In addition to warming temperatures, Arctic ecosystems are responding to climate change with earlier snowmelt and soil thaw. Earlier snowmelt has been examined infrequently in field experiments, and we lack a comprehensive look at belowground responses of the soil biogeochemical system that includes plant roots, decomposers, and soil nutrients. We experimentally advanced the timing of snowmelt in factorial combination with an open‐top chamber warming treatment over a 3‐year period and evaluated the responses of decomposers and nutrient cycling processes. We tested two alternative hypotheses: (a) Early snowmelt and warming advance the timing of root growth and nutrient uptake, altering the timing of microbial and invertebrate activity and key nutrient cycling events; and (b) loss of insulating snow cover damages plants, leading to reductions in root growth and altered biological activity. During the 3 years of our study (2010–2012), we advanced snowmelt by 4, 15, and 10 days, respectively. Despite advancing aboveground plant phenology, particularly in the year with the warmest early‐season temperatures (2012), belowground effects were primarily seen only on the first sampling date of the season or restricted to particular years or soil type. Overall, consistent and substantial responses to early snowmelt were not observed, counter to both of our hypotheses. The data on soil physical conditions, as well interannual comparisons of our results, suggest that this limited response was because of the earlier date of snowmelt that did not coincide with substantially warmer air and soil temperatures as they might in response to a natural climate event. We conclude that the interaction of snowmelt timing with soil temperatures is important to how the ecosystem will respond, but that 1‐ to 2‐week changes in timing of snowmelt alone are not enough to drive season‐long changes in soil microbial and nutrient cycling processes.
The test of the ecohydrological separation hypothesis in a dry zone of the northeastern Tibetan Plateau
Authors: Qiu Xue , Zhang Mingjun , Wang Shengjie , Evaristo Jaivime , Argiriou Athanassios A. , Guo Rong , Chen Rong , Meng Hongfei , Che Cunwei , Qu Deye
Published: January 2019

The ecohydrological separation hypothesis has generated considerable scientific interest and debate in ecohydrological studies, and it assumes there exist two water pools in subsurface water, one of which is soil water used by plants and the other is that supplied to groundwater. Although this hypothesis has been tested in several humid sites, a further test in arid and semiarid conditions is still needed. Based on the isotopic ratios in different water bodies collected during a 2‐year field work, the hypothesis was tested in a drier zone located in the Qilian Mountains of the northeastern Tibetan Plateau in order to investigate whether this separation phenomenon existed in a drier climate, and whether this may be a common characteristic or an exception. The results suggested that the hydrological separation does not necessarily exist and may not even be determined by stable isotopes; there is a clear need to more precise experimental methods.
Native herbivores enhance the resistance of an anthropogenically disturbed salt marsh to Spartina alterniflora invasion
Authors: Ning Zhonghua , Xie Tian , Liu Zezheng , Bai Junhong , Cui Baoshan
Published: January 2019

The extent by which human activities create an inroad for the invasion of exotic plant species and the mechanisms that drive a disturbed ecosystem's resistance to exotic invasion is largely unknown. We investigated the mechanisms by which salt marsh resists cordgrass (Spartina alterniflora) invasion by two key factors: anthropogenic disturbance by ditching and herbivory by the native crab Helice tientsinensis. In northern China, although abiotic resistance (i.e., hyper‐stresses) inhibited the landward invasion of cordgrass to high marshes, our transplant experiments showed that anthropogenic ditching created windows of opportunity for cordgrass invasion to high marshes by enhancing propagule pressure and providing favorable (i.e., low‐salinity and high‐inundation) microhabitats for colonization. Furthermore, a native herbivore exclusion experiment showed that crab grazing strongly suppressed seedling establishment and growth of cordgrass in ditched high marshes, which gradually created native biotic resistance to cordgrass invasion. We conclude that grazing by native herbivores can enhance the resistance of high marshes to cordgrass invasion triggered by anthropogenic ditching disturbance in northern China. These findings highlight that it is critical to investigate ecosystem resistance associated with anthropogenic disturbance to better understand the multiple mechanisms of exotic plant invasion, and we call for integration of these findings into invasion control strategies.
Visible‐Light‐Induced Radical Di‐ and Trifluoromethylation of β, γ‐Unsaturated Oximes: Synthesis of Di‐ and Trifluoromethylated Isoxazolines
Authors: Zhu Mei , Fun Weijun , Guo Wenbo , Tian Yunfei , Wang Zhiqiang , Xu Chen , Ji Baoming
Published: January 2019

The visible‐light‐promoted difluoromethylation and trifluoromethylation/cyclization of β, γ‐unsaturated oximes has been successfully accomplished with fluorinated sulfones as the difluoromethylation and trifluoromethylation reagents. The reaction was proposed to proceed through a sequence comprising CF2X‐radical generation, fluoromethyl radical addition, single electron oxidation, and intramolecular cyclization to afford the corresponding di and trifluoromethylated isoxazoline derivatives in an overall redox‐neutral process.
Facile Synthesis of Molybdenum Disulfide/Carbon Nanocomposites in Polyacrylic Acid Hydrogel as Anode for Lithium‐Ion Batteries
Authors: Zong Jingui , Wang Fei , Long Yixuan , Zhao Mingshu , Yang Sen , Song Xiaoping
Published: January 2019

Molybdenum disulfide (MoS2)/carbon nanocomposites are grown in a polyacrylic acid (PAA) hydrogel system via a facile hydrothermal process and carbonization of PAA by heat treatment under an argon atmosphere. The content of the MoS2 electrode material can be controlled effectively by adjusting the immersing time of the MoS2 precursor with PAA hydrogel. The MoS2/carbon nanocomposites containing MoS2 nanosheets are uniformly embedded in a 3D interconnected network carbon matrix. The unique network structure as a nano/microreactor to produce MoS2 nanosheets contributes to suppressing the aggregation of MoS2 nanosheets and improving the conductivity of nanocomposites. The MoS2/carbon nanocomposites demonstrate a good cycling stability and superior rate performance.
An ambispective cohort study on treatment outcomes of patients with epilepsy in a tertiary epilepsy center in Rwanda and recommendations for improved epilepsy care
Authors: Van Steenkiste Frank , Fidèle Sebera , Nsanzabaganwa Wellars , Uwacu Beni , Dedeken Peter , Teuwen Dirk E. , Boon Paul
Published: January 2019

Objective

Because outcome data inform and drive healthcare decisions and improvement of patient care, this study aimed to gain a deep understanding of sociodemographic profiles and treatment outcomes of newly presenting and recently diagnosed persons living with epilepsy (PwE) at a tertiary epilepsy center in Rwanda.

Methods

In June 2016 (T1), as a first stage of this single‐center cohort study, an ambispective chart review was conducted on baseline sociodemographic and disease characteristics of PwE using a structured questionnaire. Missing data were obtained by phone interview. In 2017, follow‐up data were collected by phone interview on treatment outcomes after 15‐months (T2).

Results

Of 406 PwE screened, 235 were included at T1 and outcomes on 166 PwE were obtained at T2. More than 70% were <20 years of age, with a male preponderance. A high number of patients were aged ≥20 years, were single (67.4%), unemployed (41.5%), and had no formal education or primary level education (53.9%), possibly reflecting stigma. A mean delay in diagnosis since first seizure increased with age at first seizure, amounting to 3 years for patients aged ≥20 years. At T2, 69.6% of 166 patients who could be contacted reported no seizures in the previous month. Valproate monotherapy was the most frequently prescribed treatment. At T2, 47% had discontinued treatment, which was often not recommended by a physician, despite medical insurance coverage in >90% of patients. Only 19% reported an adverse event. Marked and partial improvement in quality of life (QoL) was reported by, respectively, 50.9% and 32.7% of patients.

Significance

Encouraging results on improved seizure control and QoL were observed at follow‐up. The treatment gap remains high due to loss to follow‐up and treatment discontinuation. In this article, we discuss needs and recommendations for improving patient care, requiring concerted efforts of stakeholders at all levels of the healthcare system.
The effects of bifenthrin and temperature on the endocrinology of juvenile Chinook salmon
Authors: Giroux Marissa , Gan Jay , Schlenk Daniel
Published: January 2019

The San Francisco Bay delta (USA) is experiencing seasonally warmer waters attributable to climate change and receives rainstorm runoff containing pyrethroid pesticides. Chinook salmon (Oncorhynchus tshawytscha) inhabit the affected waterways from hatch through smoltification, and thus juvenile fish may experience both pyrethroid and warmer water exposures. The effects of higher temperatures and pesticide exposure on presmolt Chinook are unknown. To improve understanding of the potential interaction between temperature and pesticide exposure on salmonid development, juvenile alevin and fry were reared in 11, 16.4, and 19 °C freshwater for 11 d and 2 wk, respectively, and exposed to nominal concentrations of 0, 0.15, and 1.5 µg/L bifenthrin for the final 96 h of rearing. Estradiol-17β (E2), testosterone, triiodothyronine, and thyroxine levels were measured in whole-body homogenates using hormone-specific enzyme-linked immunosorbent assays. Brain gonadotropin-releasing hormone receptor (GnRH2), dopamine receptor 2A, and growth hormone 1 (GH1) mRNA levels were measured using quantitative PCR. Results showed significantly decreased survival and condition factors observed with increasing temperature in alevin. Alevin thyroid hormones increased significantly with temperature, but fry thyroid hormones trended toward a decrease at lower temperatures with increasing bifenthrin exposure. There were significant reductions in fry testosterone and E2 at 11 °C with increasing bifenthrin treatments and significant changes in GnRH2 and GH1 gene expression in both alevin and fry, indicating potential disruption of hormonal and signaling pathways. Environ Toxicol Chem 2019;38:852–861. © 2019 SETAC

Abstract

Juvenile Chinook salmon alevin and fry were exposed to increased temperatures and environmentally relevant concentrations of bifenthrin. Survival, growth, thyroid and sex steroid hormone levels, and gene expression were measured and stage-dependent differences observed between alevin and fry.
A leaky integrate and fire model for spike generation in a neuron with variable threshold and multiple‐input–single‐output configuration
Authors: Ganguly Chittotosh , Chakrabarti Saswat
Published: January 2019

Comprehensive understanding of the phenomenon of spike transfer from one neuron to another in human brain is essential for developing spiking neuronal network models. Synapses play pivotal role in transferring information from one neuron to another. A leaky integrate and fire model of a representative neuron in multiple‐input and single‐output configuration with threshold variability for neuronal spike transfer process is proposed in this paper. A simple analytical expression of membrane potential including threshold variability over a small time interval is developed. The model captures several important features of a spiking neuron through a minimal set of model parameters. An activity dependent noise model is also suggested. An expression for the probability of generation of an action potential at axon hillock of the post‐synaptic neuron is derived from the model. Analytical and simulation results are provided to explain various aspects of the proposed model.
Systematic review and meta‐analysis of the impact of dosimetry to dysphagia and aspiration related structures
Authors: Charters Emma Kristen , Bogaardt Hans , Freeman‐Sanderson Amy L. , Ballard Kirrie J.
Published: January 2019

Background

Technological advances in radiotherapy have allowed investigations into new methods to spare healthy tissue in those treated for head and neck cancer. This systematic review with meta‐analysis demonstrates the effect that radiation has on swallowing.

Methods

Selection and analysis of studies examining the effect of radiation to swallowing structures. A fixed effects meta‐analysis calculated the pooled proportions for select outcomes of dysphagia, common across many studies.

Results

The majority of the papers found a correlation between radiation dose to the swallowing structures and dysphagia, however a meta‐analysis found the studies carried a significant degree of heterogeneity. The appraisal demonstrates the need for large‐scale studies using a randomized design and instrumental dysphagia assessments.

Conclusions

Radiation dose to dysphagia and aspiration structures is correlated with incidence of dysphagia and aspiration. The variables in this population contribute to the heterogeneity within and cross studies and future studies should consider controlling for this.
Integrating reproductive and child health services enables access to modern contraception in Sierra Leone
Authors: Koroma Ami S. , Ghatahora Sonya K. , Ellie Mariama , Kargbo Anita , Jalloh Umu H. , Kandeh Abdulai , Alieu Henry , Bah Mariama , Turay Hamid , Sonnie Mustapha , Sesay Santigie , Hodges Mary H. , Doledec David
Published: January 2019

Background

From mid‐2015, reproductive and child health interventions were integrated into a routine 6‐month contact point: vitamin A supplementation, nutrition counseling with the mother's participation in the preparation of a complementary food, and confidential family planning counseling with provision of modern forms of contraceptives. By mid‐2017, these services had reached 28% of health facilities nationwide.

Objective

To evaluate awareness and uptake of modern contraception and complementary feeding practices.

Methods

All health facilities were visited, and the health worker “in‐charge” were interviewed to ascertain their training status and supply chains. Within each catchment, community mothers of children 6 to 23 months of age were interviewed.

Results

Interviews were conducted with 321 “in‐charges” and 670 mothers. Advantages and different types of contraception were understood by 99.0% of mothers, and 52.7% reported they were utilizing depot injections, hormonal implants, or oral contraceptive pills (45.1%, 34.6%, and 20.6% of users, respectively). Uptake was higher among Christians (62.1%) versus Muslims (48.6%) and among those with secondary/tertiary (61.5%) or primary education (60.5%) versus no education (43.3%) (P < 0.005 and P < 0.05, respectively).

Complementary feeding practices included minimal meal diversity, 49.2% (fed three or more of six food groups), and recommended minimal meal frequency appropriate for age, 52.6%.

Health workers reported frequent stockouts of vitamin A capsules (8%), male condoms (1%), oral contraceptives (10%), depot injections (20%), and hormonal implants (30%).

Conclusion

In communities served by these integrated services, awareness and uptake of modern contraception exceeded national targets despite weak supply chains, and complementary feeding practices were favorable compared with the national survey.
Patient safety policies, guidelines, and protocols in Bhutan
Authors: Pelzang Rinchen , Hutchinson Alison M.
Published: January 2019

Objective

The aim of the study was to explore what policies and guidelines related to patient safety have been developed and operationalized in the Bhutanese healthcare system.

Methods

The study was conducted as a qualitative exploratory descriptive inquiry using policy and guidelines document review/analysis. Quality care and patient safety policy and guidelines documents were manually collected from the Ministry of Health and three different levels of hospitals (national referral, regional referral, and district hospitals) and reviewed. All data were analyzed using content analysis strategies, and their presentation organized according to the policy statement and/or clause/excerpts on patient safety.

Results

The review revealed that the policy and guidance documents implemented in the Bhutanese healthcare system were developed as a minimum standard for quality assurance, not those of patient safety as such.

Conclusion

The findings of this study reveal that Bhutan is in the middle of a paradigm shift—shifting from a conventional approach of quality assurance to a new paradigm of patient safety. The evidence obtained from this study suggests that the development of high‐quality guidance documents is important to improve patient safety in the Bhutanese healthcare system.
Factors influencing the selection of a picture archiving and communication system: A qualitative study
Authors: Zahiri Esfahani Misagh , Farokhzadian Jamileh , Bahaadinbeigy Kambiz , Khajouei Reza
Published: January 2019

Background

Picture Archiving and Communication System (PACS) is an evolving technology in health care domains that is used for storage, management, retrieval, transfer, and delivery of medical images. Some medical centers in Iran have installed the PACS in recent years but have not used it appropriately. One of the problems in implementing this system is inability to select appropriate PACS. Several factors are involved in the selection process. The objective of this study was to determine the factors that influence PACS selection.

Methods

This qualitative study aimed to identify factors influencing the PACS selection. Data were collected through semistructured interviews with 10 experts in three educational hospitals and in the position to make decision for the purchase of PACS. Data were analyzed by the conventional qualitative content analysis method proposed by Lundman and Graneheim.

Results

Analyses achieved 11 subcategories in two specific and general categories that influence PACS selection. The specific category of this study included six subcategories, and the general category included five subcategories.

Conclusion

The results of this study determined that usability was the most important factor from the perspective of participants. Since the main users of a system have a critical role in adoption or rejection of a system, ease of use (usability) is significant and must be considered in system selection as a significant factor.
Analysis of synonymous codon usage pattern of genes in unique non–blood‐sucking leech Whitmania pigra
Authors: Khan Muhammad Salabat , Guan De‐Long , Ma Li‐Bin , Xie Juan‐Ying , Xu Sheng‐Quan
Published: January 2019

Whitmania pigra is a unique, fluid‐sucking ectoparasite and an anticoagulant medical leech. The codon usage bias (CUB) is the nonuniform usage of synonymous codons in which some codons are more preferred than others. Here, we performed a comprehensive analysis of CUB of genes in W. pigra, analyzing 140 780 transcripts, 59 553 unigenes, and 20 304 qualified coding sequences (CDSs) from the transcriptomic data of W. pigra. The effective number of codons values suggested that the CUB was low in these genes. We recognized profoundly favored codons in W. pigra that have a G/C‐ending. Parity rule two‐bias plots suggested that both mutation pressure and natural selection might have influenced the CUB. However, neutrality plots revealed that natural selection might have played a major role while mutation pressure might have played a minor role in shaping the CUB. We applied principal component analysis to relative synonymous codon usage values for divided CDSs based on GC content and codon‐ending bases. Codon usage in
W. pigra had a general inclination toward C‐ending codons and natural selection rather than mutation pressure is the dominant force in the genetic evolution of W. pigra. To our knowledge, this is the first study to describe a complete codon usage analysis of W. pigra; this will increase the understanding of CUB and evolution in W. pigra. The analysis of codon usage patterns in W. pigra aids in understanding its evolution and genetic architecture.
The role of the halogen bond in iodothyronine deiodinase: Dependence on chalcogen substitution in naphthyl‐based mimetics
Authors: Cesario Diego , Fortino Mariagrazia , Marino Tiziana , Nunzi Francesca , Russo Nino , Sicilia Emilia
Published: January 2019

The effects on the activity of thyroxine (T4) due to the chalcogen replacement in a series of peri‐substituted naphthalenes mimicking the catalytic function of deiodinase enzymes are computationally examined using density functional theory. In particular, T4 inner‐ring deiodination pathways assisted by naphthyl‐based models bearing two tellurols and a tellurol‐thiol pair in peri‐position are explored and compared with the analogous energy profiles for the naphthalene mimic having two selenols. The presence of a halogen bond (XB) in the intermediate formed in the first step and involved in the rate‐determining step of the reaction is assumed to facilitate the process increasing the rate of the reaction. The rate‐determining step calculated energy barrier heights allow rationalizing the experimentally observed superior catalytic activity of tellurium containing mimics. Charge displacement analysis is used to ascertain the presence and the role of the electron density charge transfer occurring in the rate‐determining step of the reaction, suggesting the incipient formation or presence of a XB interaction. © 2019 Wiley Periodicals, Inc.
The impact of cardiovascular genetic counseling on patient empowerment
Authors: Ison Hannah E. , Ware Stephanie M. , Schwantes‐An Tae‐Hwi , Freeze Samantha , Elmore Lindsey , Spoonamore Katherine G.
Published: January 2019

Cardiovascular genetic counseling (CVGC) is recommended for a variety of inherited heart conditions; however, its impact on patient empowerment has not been assessed. The Genetic Counseling Outcome Scale (GCOS) is a validated patient reported outcome tool which measures empowerment to capture the impact of clinical genetics services. As a routine clinical practice at our center, adult patients attending a CVGC appointment complete the 24‐item GCOS survey and a 5‐item survey on knowledge of cardiac surveillance recommendations for relatives prior to the clinic visit. To investigate the effect of CVGC, we contacted participants after the appointment to repeat these surveys prior to genetic test result disclosure. Forty‐two participants completed pre‐ and post‐GC surveys. The mean difference between pre‐ and post‐GC empowerment scores was 17.5 points (mean pre‐GC score = 118.5, mean post‐GC score = 136, p < 0.0001; effect size, d = 0.94). Forty percent of individuals (17/42) were aware of surveillance recommendations for at‐risk family members prior to GC; this increased to 76% of individuals (32/42) post‐GC (p < 0.01). This is the first study to explore patient empowerment before and after GC in a cardiology setting. The results demonstrate a significant increase in empowerment and awareness of recommendations for at‐risk relatives as a result of CVGC. This study demonstrates the utility of CVGC in patient care.
Recommendations towards standards for quantitative MRI (qMRI) and outstanding needs
Authors: Keenan Kathryn E. , Biller Joshua R. , Delfino Jana G. , Boss Michael A. , Does Mark D. , Evelhoch Jeffrey L. , Griswold Mark A. , Gunter Jeffrey L. , Hinks R. Scott , Hoffman Stuart W. , Kim Geena , Lattanzi Riccardo , Li Xiaojuan , Marinelli Luca , Metzger Gregory J. , Mukherjee Pratik , Nordstrom Robert J. , Peskin Adele P. , Perez Elena , Russek Stephen E. , Sahiner Berkman , Serkova Natalie , Shukla‐Dave Amita , Steckner Michael , Stupic Karl F. , Wilmes Lisa J. , Wu Holden H. , Zhang Huiming , Jackson Edward F. , Sullivan Daniel C.
Published: January 2019

Level of Evidence: 5

Technical Efficacy: Stage 5

J. Magn. Reson. Imaging 2019.
23Na Triple‐quantum signal of in vitro human liver cells, liposomes, and nanoparticles: Cell viability assessment vs. separation of intra‐ and extracellular signal
Authors: Hoesl Michaela A.U. , Kleimaier Dennis , Hu Ruomin , Malzacher Matthias , Nies Cordula , Gottwald Eric , Schad Lothar R.
Published: January 2019

Background

Triple‐quantum (TQ) filtered sequences have become more popular in sodium MR due to the increased usage of scanners with field strengths exceeding 3T. Disagreement as to whether TQ signal can provide separation of intra‐ and extracellular compartments persists.

Purpose

To provide insight into TQ signal behavior on a cellular level.

Study Type

Prospective.

Phantom/Specimen

Cell‐phantoms in the form of liposomes, encapsulated 0 mM, 145 mM, 154 mM Na+ in a double‐lipid membrane similar to cells. Poly(lactic‐co‐glycolic acid) nanoparticles encapsulated 154 mM Na+ within a single‐layer membrane structure. Two microcavity chips with each 6 × 106 human HEP G2 liver cells were measured in an MR‐compatible bioreactor.

Field Strength/Sequence

Spectroscopic TQ sequence with time proportional phase‐increments at 9.4T.

Assessment

The TQ signal of viable, dead cells, and cell‐phantoms was assessed by a fit in the time domain and by the amplitude in the frequency domain.

Statistical Tests

The noise variance (σ) was evaluated to express the deviation of the measured TQ signal amplitude from noise.

Results

TQ signal >20σ was found for liposomes encapsulating sodium ions. Liposomal encapsulation of 0 mM Na+ and 154 mM Na+ encapsulation in the nanoparticles resulted in <2σ TQ signal. Cells under normal perfusion resulted in >9σ TQ signal. Compared with TQ signal under normal perfusion, a 56% lower TQ signal of was observed (25σ) during perfusion stop. TQ signal returned to 92% of the initial signal after reperfusion.

Data Conclusion

Our measurements indicate that TQ signal in liposomes was observed due to the trapping of ions within the double‐lipid membrane rather than from the intraliposomal space. Transfer to the cell results suggests that TQ signal was observed from motion restriction equivalent to trapping.

Level of Evidence: 1

Technical Efficacy: Stage 3

J. Magn. Reson. Imaging 2019;50:435–444.
Determining the optimal postlabeling delay for arterial spin labeling using subject‐specific estimates of blood velocity in the carotid artery
Authors: Gai Neville D. , Butman John A.
Published: January 2019

Background

Arterial spin labeling with 3D acquisition requires determining a single postlabeling delay (PLD) value. PLD affects the signal‐to‐noise ratio (SNR) per unit time as well as quantitative cerebral blood flow (CBF) values due to its bearing on the presence of a vascular signal.

Purpose

To search for an optimal PLD for pseudocontinuous arterial spin labeling (pCASL) using patient‐specific carotid artery blood velocity measurements.

Study Type

Prospective.

Subjects

A control group of 11 volunteers with no known pathology. Corroboration was through a separate group of six volunteers and a noncontrol group of five sickle cell disease (SCD) patients.

Field Strength/Sequence

Pseudocontinuous arterial spin labeling with 3D nonsegmented echo planar imaging acquisition at 3T.

Assessment

A perfusion‐based measure was determined over a range of PLDs for each of 11 volunteers. A third‐order polynomial was used to find the optimal PLD where the defined measure was maximum. This was plotted against the corresponding carotid artery velocity to determine a relationship between the perfusion measure and velocity. Corroboration was done using a group of six volunteers and a noncontrol group of five patients with SCD. PLD was determined from the carotid artery velocity and derived relationship and compared with optimal PLD obtained from measured perfusion over a range of PLD values. Error between the perfusion measure at predicted and measured optimal PLD was determined.

Statistical Tests

Chi‐squared goodness of fit; Pearson correlation; Bland–Altman.

Results

Carotid artery velocity was 63.8 ± 6.6 cm/s (53.1 ≤ v ≤ 72.3 cm/s) while optimal PLD was 1374 ± 226.5 msec (1102 ≤ PLD ≤ 1787 msec) across the 11 volunteers. PLD as a function of carotid velocity was determined to be PLD = −31.94. v + 3410 msec (Pearson correlation –0.93). In six volunteers, mean error between the perfusion measure at predicted and measured optimal PLD was 1.35%. Pearson correlation between the perfusion measure at the predicted PLD and the measure obtained experimentally was r = 0.96 (P < 0.001). Bland–Altman revealed a slight bias of 1.3%. For the test case of five SCD patients, the mean error was 1.3%.

Data Conclusion

Carotid artery velocity was used to determine optimal PLD for pCASL with 3D acquisition. The derived relationship was used to predict optimal PLD and the associated perfusion measure, which was found to be accurate when compared with its measured counterpart.

Level of Evidence: 2

Technical Efficacy: Stage 1

J. Magn. Reson. Imaging 2019;50:951–960.
Development of a multicomponent immunochromatographic test system for the detection of fluoroquinolone and amphenicol antibiotics in dairy products
Authors: Hendrickson OD , Zvereva EA , Shanin IA , Zherdev AV , Dzantiev BB
Published: January 2019

BACKGROUND

Ciprofloxacin (CIP) and chloramphenicol (CAP) are relevant antibiotics of the fluoroquinolone (FQ) and amphenicol (AP) groups, respectively, widely used in veterinary practice and they contaminate agricultural products. In this study, a rapid and sensitive immunochromatographic assay (ICA) was developed for simultaneous detection of CIP and CAP in dairy products. The ICA was carried out in a direct competitive format using gold nanoparticles as a label.

RESULTS

The ICA developed here allowed for the detection of CIP and CAP in Triton X‐100‐containing buffered saline (PBST) within 15 min with instrumental detection limits of 20 pg mL−1 and 0.5 ng mL−1, respectively, and with a visual detection limit of 5 ng mL−1 for both antibiotics. The ICA showed cross‐reactivity (69–160%) to 19 antibiotics in the FQ group and no cross‐reactivity (<0.1%) to 2 antibiotics of the AP group. The ICA allowed detection of CIP and CAP in a panel of dairy products by employing a simple procedure of preliminary sample preparation. The detection limits for the two antibiotics were the same as in PBST. The analytical recoveries of CIP and CAP in dairy products ranged from 83% to 120%.

CONCLUSION

The analytical characteristics of the test system allow its use for the detection of antibiotics in milk and dairy products during all steps of production. © 2019 Society of Chemical Industry
Open‐tubular capillary electrochromatography for the simultaneous determination of cadmium and copper in plants
Authors: Stege Patricia W. , Forlin Gisela L. , Gásquez José A. , Sombra Lorena L.
Published: January 2019

We discuss the separation and determination of cadmium and copper in plant samples such as Triticum durum (wheat) and Helianthus annuus (sunflower) using open tubular capillary electrochromatography with indirect detection. Before performing the analysis, the samples were digested by microwave‐assisted methods using HNO3. Regarding the electrophoretic system, several experimental parameters were previously evaluated such as the capillary surface, mobile phase composition, buffer, pH, and voltage applied. The baseline resolution of the studied metals was obtained within 8 min by using a capillary immobilized with carboxylic multi‐walled carbon nanotubes and a background electrolyte composed of 6 mM imidazole, pH 4.0. The applied voltage and the temperature were set at 20 kV and 25°C, respectively. Precision, detection, and quantification limits, along with linearity were investigated. The limits of detection and quantification were 2.20 and 7.40 μg/kg, for Cu2⁺ and 0.05 and 0.20 μg/kg in the case of Cd2⁺. A good linearity was achieved over a concentration working range of 7.5–100 and 0.2–25 μg/kg for Cu2⁺ and Cd2⁺ accordingly. Recovery data for validation studies were found in a range of 98.2–101.5% for both analytes.
Nocturnal Olfactory Stimulation for Improvement of Sleep Quality in Patients With Posttraumatic Stress Disorder: A Randomized Exploratory Intervention Trial
Authors: Schäfer Laura , Schellong Julia , Hähner Antje , Weidner Kerstin , Hüttenbrink Karl‐Bernd , Trautmann Sebastian , Hummel Thomas , Croy Ilona
Published: January 2019

Posttraumatic stress disorder (PTSD) is characterized by sleep impairment and nightmares. As pleasant odors presented during sleep affect the emotional tone of dreams without inducing arousal, we investigated whether sleep patterns in PTSD can be improved via nocturnal olfactory stimulation. Participants were 40 inpatients with PTSD (n = 35 women; age range: 20–59 years) who completed a randomized, patient‐blind, placebo‐controlled trial. Baseline measurement for 5 consecutive nights was followed by a 5‐night experimental intervention or placebo trial. During the intervention, patients received nocturnal stimulation with a pleasant odor (odor condition) or clean air (placebo condition) via an olfactometer that delivered inspiration‐triggered stimuli in a nasal tube or via an odorized nasal clip. After each night, the patients completed standardized questionnaires that assessed sleep parameters and dream content. Each night, sleep efficiency, sleep onset latency, and wakefulness after sleep onset were monitored with a motion biosensor. Baseline assessment revealed that PTSD severity was associated with poorer sleep outcomes. An interaction effect showed that nocturnal odorization affected dream intensity. Post hoc tests revealed an improvement in the group that used the nasal clip as compared to baseline, d = 0.68. No negative effects were observed after odorization with the nasal clip. Considering the limited sample size, the study indicates that nocturnal olfactory stimulation may serve as a low‐cost concomitant intervention to improve sleep quality in PTSD.
Kinetics of two redox reactions in 2‐butoxyethanol and water near its critical point of solution
Authors: Du Zhongyu , Duan Siyu , Ma Mingfang , Xu Xiangyu , Li Zhenquan , Kong Lingdong , Liu Jun
Published: January 2019

The rate constants of two redox reactions and in the critical solution of 2‐butoxyethanol and water have been measured by using the UV spectrophotometry at the initial reaction stage. It was found that the rate constants at various temperatures for two reactions were well described by the Arrhenius equation in the noncritical region. The critical slowing down effect was detected in the critical region. The critical slowing down exponents were determined to be 0.044 ± 0.004 and 0.046 ± 0.005 for reactions and , respectively. The values of the critical slowing down exponents showed that only dynamic critical slowing down effect, and no thermodynamic singularity could be observed for the two reactions.
Localized corrosion of carbon steel in seawater: Processes occurring in cathodic zones
Authors: Duboscq Julien , Sabot René , Jeannin Marc , Refait Philippe
Published: January 2019

The composition of the corrosion product layer forming on carbon steel in seawater depends on the cathodic/anodic character of the metal surface underneath. This variability is mainly linked to that of interfacial pH, that decreases in anodic zones and increases in cathodic zones. To study the role of pH on these phenomena, two types of experiments were achieved. First, carbon steel coupons were immersed 10 days in artificial seawater in conditions favoring differential aeration cells and the resulting corrosion product layer was characterized by X‐ray diffraction. Lepidocrocite (γ‐FeOOH) and aragonite (CaCO3) proved to be the major components of this layer in the anodic and cathodic zones, respectively, while the sulfate and carbonate green rusts, GR(SO42‐) and GR(CO32‐), were observed as minor components. Secondly, aqueous suspensions of GR(SO42‐) and GR(CO32‐) were prepared in the laboratory to study the equilibrium conditions where both compounds can co‐exist. A pK value of 7.85 ± 0.35 could be estimated, leading to an equilibrium pH of 8.24 ± 0.35 in seawater, consistent with the observed predominance of GR(SO42‐) in the anodic zones and GR(CO32‐) in the cathodic zones.
Functional polymorphisms on chromosome 5p15.33 disturb telomere biology and confer the risk of non‐small cell lung cancer in Chinese population
Authors: Li Ying , Xiang Cheng , Shen Na , Deng Lingyan , Luo Xia , Yuan Peihong , Ji Zhi , Li Jiaoyuan , Cheng Liming
Published: January 2019

The chromosome 5p15.33 has been reported as a susceptibility locus for lung cancer. However, causal variants in this region have not been fully uncovered. In this study, we intended to identify functional polymorphisms associated with non‐small cell lung cancer (NSCLC) susceptibility in Chinese population. A targeted sequencing on 5p15.33 region was conducted in 400 NSCLC cases. We selected candidate variants by comparing genotypic frequency with data from 1000 Genomes Project, and their associations with NSCLC were validated in 985 cases and 970 controls. The relationships between risk variants and telomere length were evaluated in 774 healthy subjects. Luciferase assays and electrophoretic mobility shift assays (EMSA) were performed to explore potential functions and reveal carcinogenic mechanisms. As a result, we identified 1478 variants through targeted sequencing and selected 17 candidates. Four polymorphisms exhibited prominent associations with lung cancer risk, including rs7726159 (OR = 1.34, 95%CI: 1.18‐1.52, P = 7.78 × 10−6), rs10054203 (OR = 1.29, 95%CI: 1.13‐1.46, P = 1.37 × 10−4), rs2736107 (OR = 1.28, 95%CI: 1.11‐1.47, P = 5.14 × 10−4), and rs2853677 (OR = 1.23, 95%CI: 1.08‐1.39, P = 0.002). The minor allele of rs7726159 and rs10053203 were associated with long telomeres (P = 0.008 and 0.036, respectively). Mechanistically, the rs7726159‐A increased TERT transcription through mediating allele‐specific MYC binding. In conclusion, the functional variant rs7726159 confers lung cancer susceptibility might by affecting MYC binding and inducing telomere lengthening, which provides a new insight into the crucial role of telomere biology in tumorigenesis.
Interaction of germline variants in a family with a history of early‐onset clear cell renal cell carcinoma
Authors: Nicolas Emmanuelle , Demidova Elena V. , Iqbal Waleed , Serebriiskii Ilya G. , Vlasenkova Ramilia , Ghatalia Pooja , Zhou Yan , Rainey Kim , Forman Andrea F. , Dunbrack Roland L. , Golemis Erica A. , Hall Michael J. , Daly Mary B. , Arora Sanjeevani
Published: January 2019

Background

Identification of genetic factors causing predisposition to renal cell carcinoma has helped improve screening, early detection, and patient survival.

Methods

We report the characterization of a proband with renal and thyroid cancers and a family history of renal and other cancers by whole‐exome sequencing (WES), coupled with WES analysis of germline DNA from additional affected and unaffected family members.

Results

This work identified multiple predicted protein‐damaging variants relevant to the pattern of inherited cancer risk. Among these, the proband and an affected brother each had a heterozygous Ala45Thr variant in SDHA, a component of the succinate dehydrogenase (SDH) complex. SDH defects are associated with mitochondrial disorders and risk for various cancers; immunochemical analysis indicated loss of SDHB protein expression in the patient’s tumor, compatible with SDH deficiency. Integrated analysis of public databases and structural predictions indicated that the two affected individuals also had additional variants in genes including TGFB2, TRAP1, PARP1, and EGF, each potentially relevant to cancer risk alone or in conjunction with the SDHA variant. In addition, allelic imbalances of PARP1 and TGFB2 were detected in the tumor of the proband.

Conclusion

Together, these data suggest the possibility of risk associated with interaction of two or more variants.
Functional Interactions between Gut Microbiota Transplantation, Quercetin, and High‐Fat Diet Determine Non‐Alcoholic Fatty Liver Disease Development in Germ‐Free Mice
Authors: Porras David , Nistal Esther , Martínez‐Flórez Susana , Olcoz José Luis , Jover Ramiro , Jorquera Francisco , González‐Gallego Javier , García‐Mediavilla María Victoria , Sánchez‐Campos Sonia
Published: January 2019

Scope

Modulation of intestinal microbiota has emerged as a new therapeutic approach for non‐alcoholic fatty liver disease (NAFLD). Herein, it is addressed whether gut microbiota modulation by quercetin and intestinal microbiota transplantation can influence NAFLD development.

Methods and results

Gut microbiota donor mice are selected according to their response to high‐fat diet (HFD) and quercetin in terms of obesity and NAFLD‐related biomarkers. Germ‐free recipients displayed metabolic phenotypic differences derived from interactions between microbiota transplanted, diets, and quercetin. Based on the evaluation of hallmark characteristics of NAFLD, it is found that gut microbiota transplantation from the HFD‐non‐responder donor and the HFD‐fed donor with the highest response to quercetin results in a protective phenotype against HFD‐induced NAFLD, in a mechanism that involves gut–liver axis alteration blockage in these receivers. Gut microbiota from the HFD‐responder donor predisposed transplanted germ‐free mice to NAFLD. Divergent protective and deleterious metabolic phenotypes exhibited are related to definite microbial profiles in recipients, highlighting the predominant role of Akkermansia genus in the protection from obesity‐associated NAFLD development.

Conclusions

The results provide scientific support for the prebiotic capacity of quercetin and the transfer of established metabolic profiles through gut microbiota transplantation as a protective strategy against the development of obesity‐related NAFLD.
A Series of Analogues to the AT2R Prototype Antagonist C38 Allow Fine Tuning of the Previously Reported Antagonist Binding Mode
Authors: Isaksson Rebecka , Lindman Jens , Wannberg Johan , Sallander Jessica , Backlund Maria , Baraldi Dhaniel , Widdop Robert , Hallberg Mathias , Åqvist Johan , Gutierrez de Teran Hugo , Gising Johan , Larhed Mats
Published: January 2019

We here report on our continued studies of ligands binding to the promising drug target angiotensin II type 2 receptor (AT2R). Two series of compounds were synthesized and investigated. The first series explored the effects of adding small substituents to the phenyl ring of the known selective nonpeptide AT2R antagonist C38, generating small but significant shifts in AT2R affinity. One compound in the first series was equipotent to C38 and showed similar kinetic solubility, and stability in both human and mouse liver microsomes. The second series was comprised of new bicyclic derivatives, amongst which one ligand exhibited a five‐fold improved affinity to AT2R as compared to C38. The majority of the compounds in the second series, including the most potent ligand, were inferior to C38 with regard to stability in both human and mouse microsomes. In contrast to our previously reported findings, ligands with shorter carbamate alkyl chains only demonstrated slightly improved stability in microsomes. Based on data presented herein, a more adequate, tentative model of the binding modes of ligand analogues to the prototype AT2R antagonist C38 is proposed, as deduced from docking redefined by molecular dynamic simulations.