bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regional Gas Exchange Measured by 129Xe Magnetic Resonance Imaging Before and After Combination Bronchodilators Treatment in Chronic Obstructive Pulmonary Disease
Authors: Mummy David G. , Coleman Erika M. , Wang Ziyi , Bier Elianna A. , Lu Junlan , Driehuys Bastiaan , Huang Yuh‐Chin 
Published: May 2021

BackgroundHyperpolarized 129Xe magnetic resonance imaging (MRI) provides a non‐invasive assessment of regional pulmonary gas exchange function. This technique has demonstrated that chronic obstructive pulmonary disease (COPD) patients exhibit ventilation defects, reduced interstitial barrier tissue uptake, and poor transfer to capillary red blood cells (RBCs). However, the behavior of these measurements following therapeutic intervention is unknown.PurposeTo characterize changes in 129Xe gas transfer function following administration of an inhaled long‐acting beta‐agonist/long‐acting muscarinic receptor antagonist (LABA/LAMA) bronchodilator.Study TypeProspective.PopulationSeventeen COPD subjects (GOLD II/III classification per Global Initiative for Chronic Obstructive Lung Disease criteria) were imaged before and after 2 weeks of LABA/LAMA therapy.Field Strength/SequencesDedicated ventilation imaging used a multi‐slice 2D gradient echo sequence. Three‐dimensional images of ventilation, barrier uptake, and RBC transfer used an interleaved, radial, 1‐point Dixon sequence. Imaging was acquired at 3 T.Assessment129Xe measurements were quantified before and after LABA/LAMA treatment by ventilation defect + low percent (vendef + low) and by barrier uptake and RBC transfer relative to a healthy reference population (bar%ref and RBC%ref). Pulmonary function tests, including diffusing capacity of the lung for carbon monoxide (DLCO), were also performed before and after treatment.Statistical TestsPaired t‐test, Pearson correlation coefficient (r).ResultsBaseline vendef + low was 57.8 ± 8.4%, bar%ref was 73.2 ± 19.6%, and RBC%ref was 36.5 ± 13.6%. Following treatment, vendef + low decreased to 52.5 ± 10.6% (P < 0.05), and improved in 14/17 (82.4%) of subjects. However, RBC%ref decreased in 10/17 (58.8%) of subjects. Baseline measurements of bar%ref and DLCO were correlated with the degree of post‐treatment change in vendef + low (r = −0.49, P < 0.05 and r = −0.52, P < 0.05, respectively).ConclusionLABA/LAMA therapy tended to preferentially improve ventilation in subjects whose 129Xe barrier uptake and DLCO were relatively preserved. However, newly ventilated regions often revealed RBC transfer defects, an aspect of lung function opaque to spirometry. These microvasculature abnormalities must be accounted for when assessing the effects of LABA/LAMA therapy.Level of Evidence1Technical Efficacy Stage4
Selecting Markov chain orders for generating daily precipitation series across different Köppen climate regimes
Authors: Wilson Kemsley Sarah , Osborn Timothy J. , Dorling Stephen R. , Wallace Craig , Parker Joanne 
Published: May 2021

AbstractMarkov chain models are a commonly used statistical technique to generate realistic sequences of precipitation, but the choice of model order can strongly affect their performance. Although it is widely accepted that a first‐order Markov chain reproduces precipitation occurrence in temperate latitudes quite well, it is also well known that first‐order models have several shortcomings. These include a limited memory of rare events and inaccurately reproducing the distribution of dry‐spell lengths, and their performance outside of temperate regions is less well understood. We present, therefore, the first assessment of model‐order optimization which is both global in extent and which uses four evaluation methods: the Bayesian information criterion (BIC) and each model‐order's ability to reproduce wet‐ and dry‐spell lengths, and the interannual variability of precipitation occurrence. As well as a global analysis, we also assessed Markov chain performance and model‐order selection separately within five climate regimes based on the Köppen classification system: tropical, dry, temperate, continental and polar. These metrics were used to determine the best performing model‐order to generate realistic time series of precipitation across the five different climate regimes. We find that the choice of model order is most sensitive to the performance metric and less dependent on the climate regime. Across all regimes, we show that a first‐order model performs best when evaluated with BIC and for generating realistic wet‐spell distributions across all climate regimes except tropical, where third order performs best. We also find that a third‐order model reproduces observed dry‐spell distributions the best and second order commonly reproduces the interannual variability of precipitation occurrence across all regimes except tropical, where third order once again performs best. Our findings highlight the benefits of a flexible and tailored approach to the choice of Markov chain order for constructing precipitation series.
Directional Raman scattering spectra of metal–sulfur bonds at smooth gold and silver substrates
Authors: Nyamekye Charles K. A. , Weibel Stephen C. , Smith Emily A. 
Published: May 2021

AbstractThe gold–sulfur (Au–S) and silver–sulfur (Ag–S) bonds are integral to the surface modification of metal films with alkanethiol monolayers. Although the metal–sulfur bond can be characterized with surface‐enhanced Raman spectroscopy (SERS) at roughened metal films, some applications require or perform better when using a smooth metal surface, which is not suitable for SERS signal enhancement. Directional‐surface‐plasmon‐coupled Raman scattering (directional Raman scattering) is an approach to measure metal–sulfur bonds on smooth metal films with sub‐monolayer sensitivity. The metal–sulfur bonds formed from a benzenethiol monolayer on smooth planar gold or silver films are observed in the directional Raman scattering spectra between 240 and 270 cm−1; the signal‐to‐noise ratio of the Au–S Raman peak is 60. Importantly, the directional Raman scattering signal measured with smooth metal surfaces can be simply modeled and easily compared across many samples. Directional Raman scattering can also be measured at roughened metal films, which makes it applicable for many analyses.
Profiles of Maltreatment in the Child Welfare System: Predicting Mental Health Outcomes and Examining Age as a Moderator
Authors: Huguenel Brynn M. , Leon Scott C. , Hindt Lauren A. , Lutz Nathan , Osborne Jennifer 
Published: May 2021

AbstractThis longitudinal study explored the unique profiles of maltreatment among youth in the child welfare system and examined their relation to mental health outcomes over time. We additionally examined the moderating role of age. Participants included 316 youth in the foster care system (age range: 6–13 years). Data were collected through the Department of Children and Family Services upon youths’ entry into foster care, then quarterly for the duration of care. A latent profile analysis identified five profiles of maltreatment, categorized as primary neglect (PN), neglect and physical abuse (PA), complex trauma, complex trauma with severe sexual abuse (SA), and neglect with SA. A hierarchical general linear model applied to the data revealed that all four classes predicted higher internalizing symptom trajectories compared with the PN reference class, event rate ratios (eRRs) = 1.19–1.37, but none of these associations were significantly moderated by age. Membership in the two classes categorized by complex trauma predicted higher externalizing behavior trajectories as compared to the PN reference class, eRRs = 1.11–1.13. The relation between membership in the neglect with SA class and externalizing behaviors was moderated by age, eRR = 0.83. Finally, membership in all four classes predicted higher posttraumatic stress symptoms as compared with the reference group, eRRs = 1.84–2.45, and with all associations moderated by age, eRRs = 0.51–0.53. These findings provide insight into the maltreatment experiences of youth in the child welfare system and have important implications for treatment needs.
Prognostic Role of Tumor‐Infiltrating Lymphocytes and Tumor Budding in Early Oral Tongue Carcinoma
Authors: Hori Yukiko , Kubota Akira , Yokose Tomoyuki , Furukawa Madoka , Matsushita Takeshi , Katsumata Noriyuki , Oridate Nobuhiko 
Published: May 2021

Objectives/HypothesisOccult lymph metastasis is an important prognosticator for the treatment of early oral tongue squamous cell carcinoma (SCC). The objective of this study was to evaluate the prognostic significance of tumor‐infiltrating lymphocytes (TILs) in early oral tongue SCC. The combination of the TIL subtype and intermediate‐ or high‐grade budding scores was investigated as a prognostic marker for occult neck metastases.Study DesignRetrospective study.MethodsSpecimens from 62 patients with early oral tongue SCC treated with only primary surgery were analyzed by immunohistochemistry for CD4+, CD8+, FoxP3+, and CD45RO+ T cells and CD163+ macrophages. The highest number of each TIL subtype was counted in two areas of parenchyma and stroma in the tumor (Tumor) and peripheral stroma of the invasion margin.ResultsBased on multivariate analysis, a high density of Tumor CD163+ macrophages served as the poorest prognostic factor for regional control (RC) and disease‐free survival (DFS). Patients with both a high density of Tumor CD163+ macrophages and an intermediate‐ or a high‐grade budding score had a poor prognosis for RC according to the log‐rank test.ConclusionsIn summary, each TIL subtype may use different mechanisms during early and advanced stages of oral tongue SCC. A high density of Tumor CD163+ macrophages was determined to be a risk factor for RC and DFS as well as an additional stratification factor for RC in patients with intermediate‐ or high‐grade budding scores. Therefore, identifying TIL subtypes in daily clinical practice can help determine a more successful and individualized therapeutic approach for early oral tongue SCC.Level of EvidenceStep 4 (Level 4) Laryngoscope, 131:2512–2518, 2021
Discordant SARS‐CoV‐2 Detection in the Nasopharynx Versus Trachea for Patients With Tracheostomies
Authors: Smith Joshua D. , Correll Jason A. , Stein Jennifer L. , Kupfer Robbi A. , Hogikyan Norman D. , Morrison Robert J. , Stein Andrew P. 
Published: May 2021

Objectives/HypothesisPatients with tracheostomies have an anatomically altered connection between their upper and lower airways that could impact SARS‐CoV‐2 testing. Our goal was to evaluate for discordance in SARS‐CoV‐2 detection in hospitalized patients with COVID‐19 and tracheostomies based on the site analyzed.Study DesignRetrospective chart review.MethodsThis single‐institution study evaluated hospitalized patients with COVID‐19 who had tracheostomies placed during their treatment. We analyzed SARS‐CoV‐2 RNA nucleic acid amplification test (NAAT) results after tracheostomy. All included patients had nasopharyngeal (NP) and tracheal (TR) samples taken within a 48‐hour period, allowing us to characterize rate of test concordance.ResultsForty‐five patients met our inclusion criteria. Thirty‐two (71.1%) patients had entirely concordant results after tracheostomy. However, 13 (28.9%) patients had at least one set of discordant results, the majority of which were NP negative and TR positive. There were no statistically significant differences in demographic or clinical variables, including time to tracheostomy and time to testing, among patients with concordant versus discordant SARS‐CoV‐2 results.ConclusionThis represents the first study to examine SARS‐CoV‐2 RNA NAAT concordance between NP and TR sites in hospitalized patients with COVID‐19 and tracheostomies. One‐third of patients demonstrated discordant testing when NP and TR specimens were collected within a 48‐hour time period. Thus, patients with tracheostomies may have a higher false‐negative rate if only one site is assessed for SARS‐CoV‐2. We recommend analyzing samples from both the nasopharynx and trachea for these patients until more prospective data exist.Level of Evidence4 Laryngoscope, 131:E2634–E2638, 2021
Narrative review of the role of inflammation in gastroesophageal reflux disease. Can food allergies play a part?
Authors: Swain Lucy Kensett 
Published: May 2021

AbstractAcid suppression is the accepted treatment for gastroesophageal reflux disease, despite being ineffective in one third of patients. Certain conditions presenting as reflux may later be attributed to food allergy (infant cow's milk allergy; eosinophilic esophagitis), but the role of food allergy in adult reflux disease has rarely been investigated. The mechanisms of gastroesophageal reflux disease are examined to explore potential subgroups within the population, such as undisclosed food allergy, which may determine the responsiveness to treatment. The relevant literature was searched systematically using ProQuest Dialog, yielding 113 papers that were evaluated for quality. The extracted evidence was formed into a mechanistic diagram representing the processes of disease. As yet, insufficient research exists to evaluate the relationship between food allergies and reflux in adults. Of significance, however, is the potential for multiple variables to affect the integrity of the esophageal mucosa, thereby allowing symptoms to emerge which are independent of acid exposure. Where nonacidic drivers of inflammation exist, acid suppression is unlikely to offer adequate symptom resolution and may serve to explain the high proportion of nonresponders in this group. The review concludes that symptoms of gastroesophageal reflux may emerge in response to the coexistence of physiological reflux and esophageal mucosal inflammation. The latter may arise due to reflux‐induced acid erosion, or due to alternative endogenous sources of inflammation. When a patient presents with refractory reflux and a history of allergic disease, the role of antigen‐induced inflammation should be considered for further investigation. Nonallergic individuals presenting with refractory reflux symptoms may benefit from further analysis of relevant co‐morbidities that have the capacity to compromise mucosal integrity, including obesity or psychological stress. The identification of specific mediators of inflammation in refractory reflux disease may enable the development of personalized treatment regimes which improve outcomes and reduce the reliance on acid suppressants.
Heat‐ and Light‐Responsive Materials Through Pairing Dynamic Thiol–Michael and Coumarin Chemistry
Authors: Chakma Progyateg , Wanasinghe Shiwanka V. , Morley Colleen N. , Francesconi Sebastian C. , Saito Kei , Sparks Jessica L. , Konkolewicz Dominik 
Published: May 2021

AbstractCovalent adaptable networks (CANs) based on the thiol–Michael (TM) linkages can be thermal and pH responsive. Here, a new vinyl‐sulfone‐based thiol–Michael crosslinker is synthesized and incorporated into acrylate‐based CANs to achieve stable materials with dynamic properties. Because of the reversible TM linkages, excellent temperature‐responsive re‐healing and malleability properties are achieved. In addition, for the first time, a photoresponsive coumarin moiety is incorporated with TM‐based CANs to introduce light‐mediated reconfigureability and postpolymerization crosslinking. Overall, these materials can be on demand dynamic in response to heat and light but can retain mechanical stability at ambient condition.
Impact of assimilating Mode‐S EHS winds in the Met Office's high‐resolution NWP model
Authors: Li Zhihong 
Published: May 2021

AbstractAircraft play an important role in providing in‐situ upper air observations for use in numerical weather prediction (NWP) models. Aircraft observations of wind, temperature and humidity have been routinely assimilated into NWP models for decades. More recently, the Met Office has installed a network of six receivers to collect Mode‐Select Enhanced Surveillance (Mode‐S EHS) broadcasts and derive wind and temperature information. The paper focuses on the assimilation of high‐frequency (sub‐hourly) Mode‐S winds into the Met Office's hourly cycling high‐resolution NWP model, which employs four‐dimensional‐variational data assimilation (4D‐Var). An observing system experiment (OSE) experiment was carried out to assess the impact of additionally assimilating Mode‐S wind data on the model forecasts in both summer and winter. It is shown that assimilating Mode‐S winds has a positive benefit on the forecast skill in the first 6 hr wind profiles, with an improvement of the mean bias and root mean square (RMS) errors of up to 0.5 m·s−1 in the first hour and 0.3 m·s−1 in the sixth hour. The assimilation of Mode‐S winds is also seen to be beneficial to the near‐surface‐focused UK NWP composite index, and to the hourly precipitation accumulations in fractions skill score (FSS) for forecasts up to 9 hr ahead.
Deep learning‐based multi‐modal computing with feature disentanglement for MRI image synthesis
Authors: Fei Yuchen , Zhan Bo , Hong Mei , Wu Xi , Zhou Jiliu , Wang Yan 
Published: May 2021

PurposeDifferent Magnetic resonance imaging (MRI) modalities of the same anatomical structure are required to present different pathological information from the physical level for diagnostic needs. However, it is often difficult to obtain full‐sequence MRI images of patients owing to limitations such as time consumption and high cost. The purpose of this work is to develop an algorithm for target MRI sequences prediction with high accuracy, and provide more information for clinical diagnosis.MethodsWe propose a deep learning‐based multi‐modal computing model for MRI synthesis with feature disentanglement strategy. To take full advantage of the complementary information provided by different modalities, multi‐modal MRI sequences are utilized as input. Notably, the proposed approach decomposes each input modality into modality‐invariant space with shared information and modality‐specific space with specific information, so that features are extracted separately to effectively process the input data. Subsequently, both of them are fused through the adaptive instance normalization (AdaIN) layer in the decoder. In addition, to address the lack of specific information of the target modality in the test phase, a local adaptive fusion (LAF) module is adopted to generate a modality‐like pseudo‐target with specific information similar to the ground truth.ResultsTo evaluate the synthesis performance, we verify our method on the BRATS2015 dataset of 164 subjects. The experimental results demonstrate our approach significantly outperforms the benchmark method and other state‐of‐the‐art medical image synthesis methods in both quantitative and qualitative measures. Compared with the pix2pixGANs method, the PSNR improves from 23.68 to 24.8. Moreover the ablation studies have also verified the effectiveness of important components of the proposed method.ConclusionThe proposed method could be effective in prediction of target MRI sequences, and useful for clinical diagnosis and treatment.
Validating pore size estimates in a complex microfiber environment on a human MRI system
Authors: Huang Chu‐Chung , Hsu Chih‐Chin Heather , Zhou Feng‐Lei , Kusmia Slawomir , Drakesmith Mark , Parker Geoff J. M. , Lin Ching‐Po , Jones Derek K. 
Published: May 2021

PurposeRecent advances in diffusion‐weighted MRI provide “restricted diffusion signal fraction” and restricting pore size estimates. Materials based on co‐electrospun oriented hollow cylinders have been introduced to provide validation for such methods. This study extends this work, exploring accuracy and repeatability using an extended acquisition on a 300 mT/m gradient human MRI scanner, in substrates closely mimicking tissue, that is, non‐circular cross‐sections, intra‐voxel fiber crossing, intra‐voxel distributions of pore‐sizes, and smaller pore‐sizes overall.MethodsIn a single‐blind experiment, diffusion‐weighted data were collected from a biomimetic phantom on a 3T Connectom system using multiple gradient directions/diffusion times. Repeated scans established short‐term and long‐term repeatability. The total scan time (54 min) matched similar protocols used in human studies. The number of distinct fiber populations was estimated using spherical deconvolution, and median pore size estimated through the combination of CHARMED and AxCaliber3D framework. Diffusion‐based estimates were compared with measurements derived from scanning electron microscopy.ResultsThe phantom contained substrates with different orientations, fiber configurations, and pore size distributions. Irrespective of one or two populations within the voxel, the pore‐size estimates (~5 μm) and orientation‐estimates showed excellent agreement with the median values of pore‐size derived from scanning electron microscope and phantom configuration. Measurement repeatability depended on substrate complexity, with lower values seen in samples containing crossing‐fibers. Sample‐level repeatability was found to be good.ConclusionWhile no phantom mimics tissue completely, this study takes a step closer to validating diffusion microstructure measurements for use in vivo by demonstrating the ability to quantify microgeometry in relatively complex configurations.
Topological synthesis of crystalline Ag/T‐Nb2O5 nanobelts with enhanced solar photoelectrochemical properties for splitting water
Authors: Wen Puhong , Jiang Xiaowen , He Qian , Hu Dengwei , Ren Lijun , Zhao Weixing 
Published: May 2021

AbstractThe tetragonal phase Nb2O5 (T‐Nb2O5) nanobelts with preferentially exposed the (010) facet have been successfully prepared for the first time by insitu topological reaction using the KNb3O8 nanobelts as the precursor. Meanwhile, the transformation mechanism of the crystal structure and morphology from the layered KNb3O8 nanobelt to the T‐Nb2O5 nanobelt was revealed in detail by using XRD, FE‐SEM, TEM, HRTEM, SAED, UV‐vis DRS, EDX, XPS, and Raman spectra. In addition, Ag deposited T‐Nb2O5 (Ag/T‐Nb2O5) nanobelts were prepared by photo‐reduction reaction. The photoelectrochemical properties of the T‐Nb2O5 nanobelts and Ag/T‐Nb2O5 nanobelts as a photocatalyst were evaluated by splitting water under simulated sunlight. The results show that the photocurrent density generated by the prepared Ag/T‐Nb2O5 sample is 48.1 µA∙cm−2, which is 2.3 times that of the T‐Nb2O5 sample, and the prepared tetragonal phase T‐Nb2O5 nanobelts produce a photocurrent value 1.5 times that of the contrast orthogonal phase O‐Nb2O5 nanosheets. It indicates that the (010) facet of the tetragonal phase Nb2O5 is one of the highest photocatalytic active surfaces, and the visible light utilization efficiency of the T‐Nb2O5 nanobelt with Ag deposited on the surface has been significantly improved, which implies that it has potential applications in the field of photocatalysis.