bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cyclic nucleotides in archaea: Cyclic di‐AMP in the archaeonHaloferax volcaniiand its putative role
Authors: Braun Frank , Thomalla Laura , van der Does Chris , Quax Tessa E. F. , Allers Thorsten , Kaever Volkhard , Albers Sonja‐Verena 
Published: March 2019

AbstractThe role of cyclic nucleotides as second messengers for intracellular signal transduction has been well described in bacteria. One recently discovered bacterial second messenger iscyclicdi‐adenylatemonophosphate (c‐di‐AMP), which has been demonstrated to be essential in bacteria. Compared to bacteria, significantly less is known about second messengers in archaea. This study presents the first evidence of in vivo presence of c‐di‐AMP in an archaeon. The model organismHaloferax volcaniiwas demonstrated to produce c‐di‐AMP. Its genome encodes one diadenylate cyclase (DacZ) which was shown to produce c‐di‐AMP in vitro. Similar to bacteria, thedacZgene is essential and homologous overexpression of DacZ leads to cell death, suggesting the need for tight regulation of c‐di‐AMP levels. Such tight regulation often indicates the control of important regulatory processes. A central target of c‐di‐AMP signaling in bacteria is cellular osmohomeostasis. The results presented here suggest a comparable function inH. volcanii. A strain with decreased c‐di‐AMP levels exhibited an increased cell area in hypo‐salt medium, implying impaired osmoregulation. In summary, this study expands the field of research on c‐di‐AMP and its physiological function to archaea and indicates that osmoregulation is likely to be a common function of c‐di‐AMP in bacteria and archaea.
Strain sensing based on a core diameter mismatch structure
Authors: Fernandes Cindy S. , Rocco Giraldi Maria Thereza M. , de Sousa Marco J. , Costa João C. W. A. , Rodrigues Leonardo D. , da Silva Filipe R. B. , Ferreira Gabriel F. , dos Reis Renan A. N. 
Published: March 2019

AbstractIn this paper, it is proposed and experimentally investigated a sensor structure based on a core diameter mismatch technique for strain sensing. An uncoated short section of multimode fiber is spliced between two standard single mode fibers forming the sensor structure, called the SMS (single‐mode‐multimode‐single‐mode) sensor. The proposed SMS sensor, in the strain analysis, generates destructive or constructive interference patterns as load or strain are applied, changing the power of the optical signal only, without varying the wavelength. The sensor configuration offers several motivating attributes, such as easy fabrication, low‐cost, high‐efficiency and high sensitivity, moreover allows interrogation of the optical signal using the transmitted or reflected total optical power. The results and these advantages indicate that the proposed SMS sensor device is suitable for strain measurement, which is helpful in a broad range of applications, for instance, structural health monitoring.
Similarity clustering‐based atlas selection for pelvic CT image segmentation
Authors: Kennedy Angel , Dowling Jason , Greer Peter B , Holloway Lois , Jameson Michael G , Roach Dale , Ghose Soumya , Rivest‐Hénault David , Marcello Marco , Ebert Martin A 
Published: March 2019

PurposeTo demonstrate selection of a small representative subset of images from a pool of images comprising a potential atlas (PA) pelvic CT set to be used for autosegmentation of a separate target image set. The aim is to balance the need for the atlas set to represent anatomical diversity with the need to minimize resources required to create a high quality atlas set (such as multiobserver delineation), while retaining access to additional information available for the PA image set.MethodsPreprocessing was performed for image standardization, followed by image registration. Clustering was used to select the subset that provided the best coverage of a target dataset as measured by postregistration image intensity similarities. Tests for clustering robustness were performed including repeated clustering runs using different starting seeds and clustering repeatedly using 90% of the target dataset chosen randomly. Comparisons of coverage of a target set (comprising 711 pelvic CT images) were made for atlas sets of five images (chosen from a PA set of 39 pelvic CT and MR images) (a) at random (averaged over 50 random atlas selections), (b) based solely on image similarities within the PA set (representing prospective atlas development), (c) based on similarities within the PA set and between the PA and target dataset (representing retrospective atlas development). Comparisons were also made to coverage provided by the entire PA set of 39 images.ResultsExemplar selection was highly robust with exemplar selection results being unaffected by choice of starting seed with very occasional change to one of the exemplar choices when the target set was reduced. Coverage of the target set, as measured by best normalized cross‐correlation similarity of target images to any exemplar image, provided by five well‐selected atlas images (mean = 0.6497) was more similar to coverage provided by the entire PA set (mean = 0.6658) than randomly chosen atlas subsets (mean = 0.5977). This was true both of the mean values and the shape of the distributions. Retrospective selection of atlases (mean = 0.6497) provided a very small improvement over prospective atlas selection (mean = 0.6431). All differences were significant (P < 1.0E‐10).ConclusionsSelection of a small representative image set from one dataset can be utilized to develop an atlas set for either retrospective or prospective autosegmentation of a different target dataset. The coverage provided by such a judiciously selected subset has the potential to facilitate propagation of numerous retrospectively defined structures, utilizing additional information available with multimodal imaging in the atlas set, without the need to create large atlas image sets.
A new ultrafast 3D gradient echo‐based imaging method using quadratic‐phase encoding
Authors: Ryu Jae‐Kyun , Han SoHyun , Oh Se‐Hong , Lee Joonsung , Kim Seong‐Gi , Park Jang‐Yeon 
Published: March 2019

PurposeTo propose a novel 3D ultrafast gradient echo‐based MRI method, dubbed RASE, using quadratic‐phase encoding.Theory and MethodsSeveral characteristics of RASE, including spin behaviors, spatial resolution, SNR, and reduction of susceptibility‐induced signal loss, were analytically described. A way of compensating for TE variation was suggested in the quadratic phase‐encoding direction. Lemon, in vivo rat and mouse images were demonstrated at 9.4T, including a feasibility study for DCE‐MRI as one of promising applications.ResultsRASE was successfully demonstrated by lemon and in vivo rat brain imaging, showing a good robustness to field inhomogeneity. Contribution of the quadratic phase to signal enhancement in a range of magnetic susceptibilities was also evaluated by simulation. Taking a geometric mean of 2 phantom data acquired with opposite gradient polarities effectively compensated for the effect of TE variation. Preliminary DCE‐MRI results were also presented, showing that RASE could more accurately estimate Gd concentration than FLASH.ConclusionRASE offers a shorter effective TE, having less sensitivity to field inhomogeneity and T2* effects, much less Nyquist ghosting or chemical‐shift artifacts than gradient echo EPI (GE‐EPI). We highly anticipate that RASE can be an alternative to GE‐EPI in many applications, particularly those requiring high spatial and temporal resolutions in a broad volume coverage.
3D‐multi‐spectral T2 mapping near metal implants
Authors: Bhave Sampada , Koff Matthew F. , Sivaram Kaushik S. , Potter Hollis G. , Koch Kevin M. 
Published: March 2019

Purpose
Due to host‐mediated adverse reaction to metallic debris, there is an increasing need for noninvasive assessment of the soft tissue surrounding large joint arthroplasties. Quantitative mapping can be beneficial for tissue characterization and early diagnosis of tissue pathology but current mapping techniques lack the capability to image near metal hardware. A novel multi‐spectral mapping technique is proposed to address this unmet need.
Methods
A mapping pulse sequence based on routinely implemented 3D multi‐spectral imaging (3D‐MSI) pulse sequences is described and demonstrated. The 3D‐MSI pulse sequence is altered to acquire images at 2 echo times. Phantom and knee experiments were performed to assess the quantitative capabilities of the sequence in comparison to a commercially available mapping sequence. The technique was demonstrated for use within a clinical protocol in 2 total hip arthroplasty (THA) cases to assess variations within the periprosthetic joint space.
Results
The proposed multi‐spectral mapping technique agreed, within experimental errors, with values derived from a commercially available clinical standard of care mapping sequence. The same level of agreement was observed in quantitative phantoms and in vivo experiments. In THA cases, the method was able to assess variations of within the synovial envelope immediately adjacent to implant interfaces.
Conclusions
The proposed 3D‐MSI mapping sequence was successfully demonstrated in assessing tissue variations near metal implants.
Elastic analysis of ground movements around a tunnel considering a buoyant lining moving upwards
Authors: Liu Chenhui , Bezuijen Adam , Yang Min , Cachim Paulo 
Published: March 2019

SummaryA complex variable solution is derived for the ground movements around a tunnel considering the lining at different positions in the drilled hole in a linear elastic half‐plane. The soil displacements for three different convergence patterns are presented and compared. It is shown that the surface settlement trough will become flatter and wider when the lining moves upwards; the horizontal displacements are more concentrated in the region below the lining; and the region influenced by displacements is wider. Most calculated settlement troughs can be well represented by Gaussian curves with simple parameters, but the obtained width parameters are larger than the traditional empirical values. The rigorous solution can be used as a simple tool to understand the fundamental mechanism of the lining buoyancy problem and as a benchmark for numerical procedures based on more sophisticated models. The importance of buoyancy effect on the displacement field should be taken into account.
Evidence‐based practice integration in hospital wards—The complexities and challenges in achieving evidence‐based practice in clinical nursing
Authors: Renolen Åste , Hjälmhult Esther , Høye Sevald , Danbolt Lars Johan , Kirkevold Marit 
Published: March 2019

AbstractAimExploring the processes involved in two different strategies to integrate evidence‐based practice into nursing practice.DesignClassical grounded theory methodology was used.MethodsData were collected through 90 hr of observation and 4 focus groups among clinical nurses in two different hospital wards.ResultsWe identified a multidimensional evidence‐based practice integration framework that illuminates the complexities involved in the integration process. The dimensions were approaches to evidence‐based practice, positions of evidence‐based practice and levels of evidence‐based practice. The interactions between the dimensions gave five combinations; an explicit evidence‐based practice performed as a parallel to daily work at the systems level, an implicit evidence‐based practice integrated into daily work at the systems level, an explicit evidence‐based practice integrated into daily work at the individual level, an explicit evidence‐based practice integrated into daily work at the systems level and an implicit evidence‐based practice integrated into daily work at the individual level.
Thermal conductivity of poly(L‐Lactic Acid) subjected to elongational deformations
Authors: Venerus David C. , Agarwal Abhilesh 
Published: March 2019

ABSTRACTThe thermal conductivity of poly(L‐lactic acid) specimens subjected to uniaxial elongational deformations in the rubbery state followed by quenching is investigated experimentally. A novel optical technique known as forced Rayleigh scattering is used to measure two components of the thermal diffusivity tensor as a function of elongation. The component along the direction of elongation increases, while the component in the direction perpendicular to elongation decreases, relative to the equilibrium value. Measurements of the stress at the point of quenching, as well as the density and specific heat capacity, are also reported as a function of elongation. Anisotropy of the thermal conductivity tensor is more than 50% at moderate elongations, and it is found to be a nonlinear function of stress. The latter is in contrast to results found in previous studies where a linear relationship between thermal conductivity anisotropy and stress, or the stress‐thermal rule, has been observed for several amorphous polymer systems. Failure of the stress‐thermal rule is attributed to the presence of semicrystalline domains in the deformed samples. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys.2019,57, 547–553
Concise Review: Boosting T-Cell Reconstitution Following Allogeneic Transplantation—Current Concepts and Future Perspectives
Authors: Simons Laura , Cavazzana Marina , André Isabelle 
Published: March 2019

Abstract
Allogeneic hematopoietic stem cell transplantation (HSCT) is the treatment of choice for a large number of malignant and nonmalignant (inherited) diseases of the hematopoietic system. Nevertheless, non-HLA identical transplantations are complicated by a severe T-cell immunodeficiency associated with a high rate of infection, relapse and graft-versus-host disease. Initial recovery of T-cell immunity following HSCT relies on peripheral expansion of memory T cells mostly driven by cytokines. The reconstitution of a diverse, self-tolerant, and naive T-cell repertoire, however, may take up to 2 years and crucially relies on the interaction of T-cell progenitors with the host thymic epithelium, which may be altered by GvHD, age or transplant-related toxicities. In this review, we summarize current concepts to stimulate reconstitution of a peripheral and polyclonal T-cell compartment following allogeneic transplantation such as graft manipulation (i.e., T-cell depletion), transfusion of ex vivo manipulated donor T cells or the exogenous administration of cytokines and growth factors to stimulate host-thymopoiesis with emphasis on approaches which have led to clinical trials. Particular attention will be given to the development of cellular therapies such as the ex vivo generation of T-cell precursors to fasten generation of a polyclonal and functional host-derived T-cell repertoire. Having been tested so far only in preclinical mouse models, clinical studies are now on the way to validate the efficacy of such T-cell progenitors in enhancing immune reconstitution following HSCT in various clinical settings. Stem Cells Translational Medicine 2019;00:1–8
Access to Polyfluorinated Tetrahydropyranyl Amides via Prins‐Ritter Cyclization under Green Conditions
Authors: Segovia Claire , Fache Fabienne , Pelotier Béatrice , Piva Olivier 
Published: March 2019

AbstractThe formation of 4‐amido‐substituted tetrahydropyrans by Prins‐Ritter cyclisation under green solvent‐free conditions was investigated. The optimal conditions were applied to the synthesis of different tetrahydropyranyl amides, and subsequently to a new family of polyfluorinated derivatives when starting from hepta‐1,6‐dien‐4‐ol.
Conductive Polymer Hydrogel Microfibers from Multiflow Microfluidics
Authors: Guo Jiahui , Yu Yunru , Wang Huan , Zhang Han , Zhang Xiaoxuan , Zhao Yuanjin 
Published: March 2019

AbstractConductive hydrogels are receiving increasing attention for their utility in electronic area applications requiring flexible conductors. Here, it is presented novel conductive hydrogel microfibers with alginate shells and poly (3, 4‐ethylenedioxythiophene): poly (4‐styrenesulfonate) (PEDOT: PSS) cores fabricated using a multiflow capillary microfluidic spinning approach. Based on multiflow microfluidics, alginate shells are formed immediately from the fast gelation reaction between sodium alginate (Na‐Alg) and sheath laminar calcium chloride flows, while PEDOT: PSS cores are solidified slowly in the hollow alginate hydrogel shell microreactors after their precursor solutions are injected in situ as the center fluids. The resultant PEDOT: PSS‐containing microfibers are with features of designed morphology and highly controllable package, because material compositions or the sizes of their shell hydrogels can be tailored by using different concentrations or flow rates of pregel solutions. Moreover, the practical values of these microfibers in stretch sensitivity and bending stability are explored based on various electrical characterizations of the compound materials. Thus, it is believed that these microfluidic spinning PEDOT: PSS conductive microfibers will find important utility in electronic applications requiring flexible electronic systems.
Chronic exposure to dichloroacetamide induces biochemical and histopathological changes in the gills of zebrafish
Authors: Zhang Yu , Sun Hong‐Jie , Zhang Jing‐Ying , Ndayambaje Emmanuel , Lin Hongjun , Chen Jianrong , Hong Huachang 
Published: March 2019

AbstractTo evaluate the impact of DCAcAm on zebrafish gill, we measure the responses of antioxidant enzyme (superoxide dismutase, SOD), lipid peroxidation (malondialdehyde, MDA), ATPase (Na+/K+‐ATPase and Ca2+/Mg2+‐ATP) and histopathological changes of gill in adult zebrafish, after exposed to different concentrations of DCAcAm (0, 1, 10, 100, and 1000 μg L−1) for 30 days. Results indicated that DCAcAm first increased and then decreased SOD activity, and DCAcAm also lowered the activities of Na+/K+‐ATPase and Ca2+/Mg2+‐ATPase. These results indicated that high affinity of DCAcAm probably be a main factor, which can damage the structures of enzymes, thereby inhibiting the SOD and ATPase activities. Besides, histopathological investigation results also manifested that chronic exposure to DCAcAm can damage the gill tissues, disrupting the normal function of gills. We conclude that chronic exposure to DCAcAm was harmful to organisms, not only influence gill function, but also further cause damage on the gill tissues.
Early‐pregnancy events and subsequent antenatal, delivery and neonatal outcomes: prospective cohort study
Authors: Al‐Memar M. , Vaulet T. , Fourie H. , Nikolic G. , Bobdiwala S. , Saso S. , Farren J. , Pipi M. , Van Calster B. , de Moor B. , Stalder C. , Bennett P. , Timmerman D. , Bourne T. 
Published: March 2019

ABSTRACTObjectiveTo assess prospectively the association between pelvic pain, vaginal bleeding, and nausea and vomiting occurring in the first trimester of pregnancy and the incidence of later adverse pregnancy outcomes.MethodsThis was a prospective observational cohort study of consecutive women with confirmed intrauterine singleton pregnancy between 5 and 14 weeks' gestation recruited at Queen Charlotte's & Chelsea Hospital, London, UK, from March 2014 to March 2016. Serial ultrasound scans were performed in the first trimester. Participants completed validated symptom scores for vaginal bleeding, pelvic pain, and nausea and vomiting. The key symptom of interest was any pelvic pain and/or vaginal bleeding during the first trimester. Pregnancies were followed up until the final outcome was known. Antenatal, delivery and neonatal outcomes were obtained from hospital records. Logistic regression analysis was used to assess the association between first‐trimester symptoms and pregnancy complications by calculating adjusted odds ratios (aOR) with correction for maternal age.ResultsOf 1003 women recruited, 847 pregnancies were included in the final analysis following exclusion of cases due to first‐trimester miscarriage (n = 99), termination of pregnancy (n = 20), loss to follow‐up (n = 32) or withdrawal from the study (n = 5). Adverse antenatal complications were observed in 166/645 (26%) women with pelvic pain and/or vaginal bleeding in the first trimester (aOR = 1.79; 95% CI, 1.17–2.76) and in 30/181 (17%) women with no symptoms. Neonatal complications were observed in 66/634 (10%) women with and 11/176 (6%) without pelvic pain and/or vaginal bleeding (aOR = 1.73; 95% CI, 0.89–3.36). Delivery complications were observed in 402/615 (65%) women with and 110/174 (63%) without pelvic pain and/or vaginal bleeding during the first trimester (aOR = 1.16; 95% CI, 0.81–1.65). For 18 of 20 individual antenatal complications evaluated, incidence was higher among women with pelvic pain and/or vaginal bleeding, despite the overall incidences being low. Nausea and vomiting in pregnancy showed little association with adverse pregnancy outcomes.ConclusionsOur study suggests that there is an increased incidence of antenatal complications in women experiencing pelvic pain and/or vaginal bleeding in the first trimester. This should be considered when advising women attending early‐pregnancy units. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.
Moderne Hochkompressions‐Turbopumpen
Authors: Schopphoff Andreas , Mekota Mirko 
Published: March 2019

SummaryModern high compression turbopumps – Theory and PracticeThe performance of turbopumps has shown a rapid development since their invention in the middle of the last century. Even though there are limitations due to geometry and general functionality, with the help of clever combinations of standard turbo pumps with Holweck stages, applications nowadays are possible where in the past ion getter pumps were needed. In particular modern high compression turbo pumps are suitable for generating UHV even in combination with small and simple backing pumps.
Single‐layer and multi‐layer wear‐resistant coatings
Authors: Kostrin D. K. 
Published: March 2019

SummaryIn this paper the formation of wear‐resistant coatings based on titanium and aluminum compounds using vacuum arc discharge and molecular nitrogen as a working gas is discussed. The experiments were carried out using an installation containing two independent evaporators and a system for attenuation and purification of the plasma flow. To obtain a high‐quality coating, it is necessary to ensure the equality of the ion flux densities coming to the substrate. The results of the experiments show that by changing the bias voltage on the substrate it is possible to adjust the content of elements in the coating and thus to control its parameters. Multi‐layer coatings have better performance characteristics, but require an improved degree of purification of the plasma flow from the droplet fraction.