bluuebunny/crossref_metadata_2025 huggingface dataset:
The role and outcomes of new supraventricular tachycardia among patients with mild heart failure
Authors: Younis Arwa , Goldenberg Ilan , McNitt Scott , Zareba Wojciech , Kutyifa Valentina , Aktas Mehmet K.
Published: February 2020

Introduction

We aimed to assess the predictors of new supraventricular tachycardia (SVT) and the association of new SVT with subsequent clinical outcomes among mild heart failure (HF) patients.

Methods and Results

The study population comprised patients enrolled in MADIT‐CRT, after exclusion of patients with atrial arrhythmias before enrollment (N = 325). Multivariate analysis was used to identify predictors of new‐onset SVT and the association of time‐dependent development of SVT with subsequent ventricular tachyarrhythmic events (VTEs), HF‐hospitalizations, and death. SVT burden was categorized into three groups based on the number of episodes per patient; (a) Low <10, (b) Intermediate ≥10 but <20, and (c) High ≥20. During mean follow up of 3.4 ± 1.1 years, 41(3%) subjects developed new SVT. African American race, diastolic blood pressure (DBP) >80 mmHg and prior non sustained ventricular arrhythmia were independent predictors for SVT. Multivariate analysis showed that the development of time‐dependent SVT was associated with a >4‐fold increased risk for VTEs (HR = 4.3; 95% CI: 1.6‐11.7; P = .004) and with a >6‐fold increased risk for all‐cause mortality (HR = 6.5; 95% CI: 2.3‐18.7; P < .001), but not with HF hospitalizations (HR = 2.2; 95% CI: 0.7‐7.2; P = .17). Intermediate, and high SVT‐burden were each independent risk factors for death when compared with Low burden (HR = 9.1; P = .03, and HR = 19.4; P < .001; respectively).

Conclusions

In patients with mild HF, the development of new‐onset SVT after device implantation is related to distinct baseline clinical and epidemiologic characteristics and is associated with a significant increase in subsequent adverse outcomes, including VTEs and death.
Cryothermal atrial linear ablation in patients with atrial fibrillation: An insight from the comparison with radiofrequency atrial linear ablation
Authors: Mukai Moe , Miyazaki Shinsuke , Hasegawa Kanae , Ishikawa Eri , Aoyama Daisetsu , Nodera Minoru , Kaseno Kenichi , Miyahara Kosuke , Matsui Akira , Shiomi Yuichiro , Tama Naoto , Ikeda Hiroyuki , Fukuoka Yoshitomo , Ishida Kentaro , Uzui Hiroyasu , Tada Hiroshi
Published: February 2020

Background

Atrial linear lesions are generally created with radiofrequency energy. We sought to evaluate the feasibility of cryothermal atrial linear ablation.

Methods and Results

Twenty‐one atrial fibrillation (AF) patients underwent linear ablation on the left atrial (LA) roof, mitral isthmus (MI), and cavotricuspid isthmus (CTI) with 8‐mm‐tip cryocatheters following pulmonary vein isolation. The data were compared with those of 31 patients undergoing linear ablation with irrigated‐tip radiofrequency catheters. Conduction block was successfully created in 18 of 20 (90%), 9 of 21 (43%), and 20 of 20 (100%) on the LA roof, MI, and CTI by endocardial cryoablation alone with 19.0 (12.0‐24.0), 30.0 (23.0‐34.0), and 14.0 (14.0‐16.0) minute cryo applications, respectively. The presence of either an interposed circumflex artery or pouch at the MI was significantly associated with failed MI block (P = .04). Conduction block was created in 25 of 31 (83.9%), 27 of 31 (87.1%), and 30 of 31 (96.8%) on the roof, MI, and CTI, respectively, by radiofrequency ablation. During the 17.5 (13.0‐31.7) months of follow‐up, freedom from AF/atrial tachycardia (AT) was significantly higher in the cryo group (P = .05); especially, recurrent AT was more frequent in the RF group (8/31 vs 1/21; P = .03). Conduction block across the roof, MI, and CTI was durable in 6 of 12 (50.0%), 4 of 12 (33.3%), and 9 of 12 (75.0%) patients during second procedures. All nine patients (except one) with recurrent ATs had at least one roof or MI conduction resumption.

Conclusions

Cryoablation is effective for creating a roof and CTI linear block, however, creating MI block by endocardial ablation alone was often challenging. Conduction resumption of LA linear block is common and recurrent arrhythmias, especially iatrogenic ATs, are more frequently observed after radiofrequency linear ablation.
Treatment of atypical pacemaker‐mediated tachycardia with ablation of the retrograde atrioventricular nodal pathway
Authors: Shelton Richard , Cho Jae H. , Joshi Shreel , Betzold Robert , Shehata Michael , Ehdaie Ashkan , Swerdlow Charles
Published: February 2020

A 25‐year‐old runner received a single‐lead, VDD pacemaker after ablation of AV nodal reentrant tachycardia complicated by intermittent AV block. The rate‐adaptive AV delay algorithm (RAAV), which shortens the sensed AV interval (SAV) at faster atrial rates, was programmed to provide a physiologic SAV with exercise. She developed repetitive, atypical, long‐RP pacemaker‐mediated tachycardia (PMT) because the RAAV shortened the antegrade SAV and retrograde conduction occurred over the slow AV nodal pathway. PMT was refractory to usual programming solutions. Using high‐density electroanatomic mapping, we were able to ablate the retrograde limb of PMT without further damaging AV conduction.
Gnpat does not play an essential role in systemic iron homeostasis in murine model
Authors: An Peng , Wang Jiaming , Wang Hao , Jiang Li , Wang Jia , Min Junxia , Wang Fudi
Published: February 2020

The GNPAT variant rs11558492 (p.D519G) was identified as a novel genetic factor that modifies the iron‐overload phenotype in homozygous carriers of the HFE p.C282Y variant. However, the reported effects of the GNPAT p.D519G variant vary among study populations. Here, we investigated the role of GNPAT in iron metabolism using Gnpat‐knockout (Gnpat−/−), Gnpat/Hfe double‐knockout (Gnpat−/−Hfe−/− or DKO) mice and hepatocyte‐specific Gnpat‐knockout mice (Gnpatfl/fl;Alb‐Cre). Our analysis revealed no significant difference between wild‐type (Gnpat+/+) and Gnpat−/− mice, between Hfe−/− and DKO mice, or between Gnpatfl/fl and Gnpatfl/fl;Alb‐Cre with respect to serum iron and tissue iron. In addition, the expression of hepcidin was not affected by deleting Gnpat expression in the presence or absence of Hfe. Feeding Gnpat−/− and DKO mice a high‐iron diet had no effect on tissue iron levels compared with wild‐type and Hfe−/− mice, respectively. Gnpat knockdown in primary hepatocytes from wild‐type or Hfe−/− mice did not alter hepcidin expression, but it repressed BMP6‐induced hepcidin expression. Taken together, these results support the hypothesis that deleting Gnpat expression has no effect on either systemic iron metabolism or the iron‐overload phenotype that develops in Hfe−/− mice, suggesting that GNPAT does not directly mediate iron homeostasis under normal or high‐iron dietary conditions.
Mesenchymal stem cell transplantation attenuates growth of chemotherapy treated oral squamous cell carcinoma in an animal model
Authors: Zurmukhtashvili Marika , Machavariani Avtandil , Dugashvili Giorgi , Grdzelidze Teimuraz , Gogilashvili Ketevan , Menabde Giorgi , Abiatari Ivane , Marks Luc
Published: February 2020

Background

Recent studies have demonstrated mesenchymal stem cell migration toward tumor locations. When applied locally, MSCs interact with the locally residing host cells. The mechanisms behind this are still unclear. We aimed to detect the possible action mechanisms of MSCs on the in vivo growth of primary human oral squamous cell carcinoma.

Methods

In mouse model of OSSC, chemotherapy with Cisplatin was done beginning from 9 day of tumor visualization. 3 weeks after tumor cell injection cultivated MSCs were administrated in tail vein or directly intra‐tumorally. Animals underwent surveillance and afterward were sacrificed. Tumor growth was measured. MSCs biodistribution was assessed with bioluminescent analysis. Tumor tissues were tested morphologically and immunohistochemically for angiogenesis, hypoxia status, and cell apoptosis.

Results

In the group treated with Cisplatin in combination with mesenchymal stem cell injection, the average size of the tumor was 98.9 ± 7.65 mm3. In the experimental group, tumor tissues were less outlined and the presence of necrotic areas and connective tissue basal layers was detected. Immunohistochemical surveys with CD31 and anti‐carbonic anhydrase 9 demonstrated strongly developed micro‐vessel structures and small isles of hypoxia in the tumor tissues. TUNEL assay revealed in the same group that tumor tissues were mostly comprised of apoptotic cells. Viable cell communities presented as small isles.

Conclusion

The study demonstrates that intra‐tumorally injected MSCs, combined with Cisplatin, leads to a minimal hypoxia status and increased apoptotic activity in tumor tissues, compared with the control group. This finding can be explained with better distribution of Cisplatin due to increased angiogenesis.
The challenges of long‐term invasive mammal management: lessons from the UK
Authors: Mill Aileen C. , Crowley Sarah L. , Lambin Xavier , McKinney Conor , Maggs Gwen , Robertson Pete , Robinson Nikki J. , Ward Alastair I. , Marzano Mariella
Published: February 2020

We consider the motivations, strategies, and costs involved in invasive mammal management undertaken in the UK. Widespread established invasive mammals require long‐term management to limit damage or spread, but ongoing management is costly and complex. Long‐term management is most effective where it is applied at a landscape scale, but this requires overarching co‐ordination between multiple stakeholders. Five challenges for successful long‐term management of invasive mammal species are identified as follows: defining landscape‐scale strategies, management co‐ordination, stakeholder and community engagement, sustainable funding, and evidence requirements. We make recommendations on the supportive infrastructure needed for effective landscape‐scale management of invasive mammals to fulfil long‐term conservation aims, as follows. 1. There is a need for evidence‐based Invasive Species Action Plans to provide strategy for the long‐term ongoing management of prioritised species at appropriate scales. 2. Where possible, multispecies approaches to invasive species management should be adopted. 3. Trusted leadership should be identified to take ownership of Action Plans and provide an overarching co‐ordination to bring individuals, organisations, and funders together. 4. Support for a centralised hub for training, data, and knowledge flows will greatly improve scientific outcomes through a searchable evidence base, and via best practice and knowledge sharing.
To see, hear, and live: 25 years of the vitamin A programme in Nepal
Authors: Thorne‐Lyman Andrew L. , Parajuli Kedar , Paudyal Naveen , Chitekwe Stanley , Shrestha Ram , Manandhar Dibya Laxmi , West Keith P.
Published: February 2020

Nepal has a rich history of vitamin A research and a national, biannual preschool vitamin A supplementation (VAS) programme that has sustained high coverage for 25 years despite many challenges, including conflict. Key elements of programme success have included (a) evidence of a 26–30% reduction in child mortality from two, in‐country randomized trials; (b) strong political and donor support; (c) positioning local female community health volunteers as key operatives; (d) nationwide community mobilization and demand creation for the programme; and (e) gradual expansion of the programme over a period of several years, conducting and integrating delivery research, and monitoring to allow new approaches to be tested and adapted to available resources. The VAS network has served as a platform for delivering other services, including anthelmintic treatment and screening for acute malnutrition. We estimate that VAS has saved over 45,000 young lives over the past 15 years of attained national coverage. Consumption of vitamin A‐ and carotenoid‐rich foods by children and women nationally remains low, indicating that supplementation is still needed. Current challenges and opportunities to improving vitamin A status include lower VAS coverage among younger children (infants 6–11 months of age), finding ways to increase availability and access to dietary vitamin A sources, and ensuring local programme investments given the recent decentralization of the government.
Potential tick vectors forTheileria equiin Israel
Authors: Tirosh‐Levy S. , Steinman A. , Einhorn A. , Apanaskevich D. A. , Mumcuoglu K. Y. , Gottlieb Y.
Published: February 2020

Theileria equiMehlhorn and Schein, 1998 (Piroplasmida: Babesiidae) is an important tick‐borne pathogen of horses that is highly endemic in many parts of the world, including Israel. The present study evaluated the potential roles of five hard tick species [Hyalomma excavatumKoch, 1844;Hyalomma marginatumKoch, 1844;Rhipicephalus turanicusPomerantsev 1936;Rhipicephalus annulatusSay, 1821;Haemaphysalis parva(Neumann, 1897) (all: Ixodida: Ixodidae)], previously found to infest horses in Israel, in acting as vectors for piroplasmosis. For this, DNA was extracted from whole ticks and, when possible, from the salivary glands in each species (n = 10–59). Polymerase chain reaction amplification and sequencing of the 18S rRNA gene were used to detectT. equiin 48 of the 127 ticks (37.8%) and in 21 of the 90 extracted salivary glands (23.3%) in all five species. All but two sequences were classified asT. equigenotype A; the remaining two were classified as genotype D. The findings of this study point toHa. parvaandR. annulatusas potential novel vectors ofT. equi, and suggest that parasite genotype selection occurs within the tick vector.
Peters anomaly: A 5‐year experience
Authors: Salik Irim , Gupta Abhishek , Tara Arjun , Zaidman Gerald , Barst Samuel
Published: February 2020

Background

Peters anomaly is a rare, congenital eye malformation characterized by an opaque cornea and blurred vision. Central corneal opacification can lead to delayed progression of visual development caused by defects in Descemet membrane and the posterior stroma. These children require several anesthetics for multiple eye examinations under anesthesia and corneal transplantation.

Aims

We sought to review the anesthetic management of patients with Peters anomaly for ophthalmologic procedures at Westchester Medical Center, a major referral center for Peters anomaly.

Methods

A retrospective chart review was completed which included pediatric patients who underwent ophthalmologic procedures related to Peters anomaly from 2013‐2018.

Results

The charts of 35 patients with Peters anomaly were reviewed: 14 patients with Peters anomaly Type I, 10 patients with Peters anomaly Type II, and 11 patients with Peters plus syndrome. Thirty patients required three procedures on average, two examinations under anesthesia pre‐ and post‐transplant, and anesthesia for the corneal transplant itself. The youngest patient encountered for examination under anesthesia was 39‐week postconceptual age. Anesthetic time for examination under anesthesia averaged 31 minutes using a laryngeal mask airway while corneal transplant averaged 104 minutes utilizing endotracheal intubation. Postanesthesia care unit stay averaged 51 minutes following examination under anesthesia and 65 minutes after corneal transplant. All examinations under anesthesia were successfully completed without adverse events with the use of a laryngeal mask airway. This case series includes two patients with Goldenhar syndrome and Al‐Gazali syndrome accompanying Peters anomaly.

Conclusion

Although limited by its retrospective nature, this case series describes the cardiac and systemic implications of patients undergoing anesthesia with Peters anomaly. Our experience indicates that general anesthesia and airway manipulation are tolerated with minor postoperative concerns in these infants. Pediatric patients with Peters anomaly require multiple anesthetics for repeated ophthalmologic interventions. The laryngeal mask airway can be routinely utilized in infants less than 3 months of age for an eye examination under anesthesia with no airway complications noted. Perioperative providers should be aware of the multisystemic implications in patients with Peters plus syndrome.
Solutions to the problems of incremental validity testing in relationship science
Authors: Wang Y. Andre , Eastwick Paul W.
Published: February 2020

Incremental validity testing (i.e., testing whether a focal predictor is associated with an outcome above and beyond a covariate) is common (e.g., 57% of Personal Relationships articles in 2017), yet it is fraught with conceptual and statistical problems. First, researchers often use it to overemphasize the novelty or counterintuitiveness of findings, which hinders cumulative understanding. Second, incremental validity testing requires that the focal predictor and the covariate represent separate constructs; researchers risk committing the “jangle fallacy” without such evidence. Third, the most common approach to incremental validity testing (i.e., standard multiple regression, 88% of articles) inflates Type I error and can produce invalid conclusions. This article also discusses the relevance of these issues to dyadic/longitudinal designs and offers concrete solutions.
Generation of Singlet Molecular Oxygen by Lipid Hydroperoxides and Nitronium Ion†
Authors: Prado Fernanda M. , Scalfo Alexsandra C. , Miyamoto Sayuri , Medeiros Marisa H.G. , Di Mascio Paolo
Published: February 2020

Singlet molecular oxygen is a reactive species involved in biological oxidative processes. The major cellular targets of singlet molecular oxygen are unsaturated fatty acids in the membrane, as well as nucleic acids and proteins. The aim of this study was to investigate whether lipids and commercial hydroperoxides generate singlet molecular oxygen, in presence of nitronium and activated nitronium ion. For this purpose, monomol light emitted in the near‐infrared region (λ = 1270 nm) was used to monitor singlet molecular oxygen decay in different solvents, with different hydroperoxides and in the presence of azide. Direct measurements of the singlet molecular oxygen spectrum at 1270 nm recorded during the reaction between lipids and commercial hydroperoxides and nitronium ions unequivocally demonstrated the formation of this excited species.
Individualistic responses of forest herb traits to environmental change
Authors: Blondeel H. , Perring M. P. , De Lombaerde E. , Depauw L. , Landuyt D. , Govaert S. , Maes S. L. , Vangansbeke P. , De Frenne P. , Verheyen K.
Published: February 2020

Intraspecific trait variation (ITV; i.e. variability in mean and/or distribution of plant attribute values within species) can occur in response to multiple drivers. Environmental change and land‐use legacies could directly alter trait values within species but could also affect them indirectly through changes in vegetation cover. Increasing variability in environmental conditions could lead to more ITV, but responses might differ among species. Disentangling these drivers on ITV is necessary to accurately predict plant community responses to global change.

We planted herb communities into forest soils with and without a recent history of agriculture. Soils were collected across temperate European regions, while the 15 selected herb species had different colonizing abilities and affinities to forest habitat. These mesocosms (384) were exposed to two‐level full‐factorial treatments of warming, nitrogen addition and illumination. We measured plant height and specific leaf area (SLA).

For the majority of species, mean plant height increased as vegetation cover increased in response to light addition, warming and agricultural legacy. The coefficient of variation (CV) for height was larger in fast‐colonizing species. Mean SLA for vernal species increased with warming, while light addition generally decreased mean SLA for shade‐tolerant species. Interactions between treatments were not important predictors.

Environmental change treatments influenced ITV, either via increasing vegetation cover or by affecting trait values directly. Species’ ITV was individualistic, i.e. species responded to different single resource and condition manipulations that benefited their growth in the short term. These individual responses could be important for altered community organization after a prolonged period.
ERP evidence suggests that confrontation with deterministic statements aligns subsequent other‐ and self‐relevant error processing
Authors: Pfabigan Daniela M. , Mielacher Clemens , Dutheil Frédéric , Lamm Claus
Published: February 2020

This study used event‐related potential (ERP) measurements to investigate whether error processing in a social context is modulated by top‐down influence of deterministic thinking, i.e., subjective beliefs that events are pre‐determined by previously existing causes. To this end, half of our participants were confronted with statements denying the existence of free will, aimed to induce more deterministic thinking, whereas the other half was assigned to a control group that read neutral statements. Thereafter, all participants performed a choice‐reaction task for their own and for the benefit of a second participant. Error rates were comparable in both groups and benefit settings, while only control participants showed enhanced post‐error slowing (PES) in other‐ compared to self‐relevant trials. On the neural level, other‐relevant errors elicited diminished early error signals (reduced ΔERN amplitudes) in deterministic‐intervention participants compared to controls. In subsequent processing, ERPs of deterministic‐intervention participants did not differentiate between the benefit settings, while controls showed reduced ΔPe amplitudes for others compared to self‐relevant errors. Taken together, our findings suggest that being confronted with deterministic compared to control statements reduced subsequent processing differences between other‐ and self‐relevant error processing. This might be beneficial in social evaluation or intergroup situations because it could decrease self‐cenetred processing biases often observed in these situations.
Red cell genotyping in Thailand: trends for blood transfusion in Asian populations
Authors: Nathalang Oytip
Published: February 2020

Numerous molecular techniques have been employed to determine well‐matched blood units for patients in need, particularly those requiring blood transfusions within 3 months and presenting positive DAT results. Only specialized reference laboratories use commercially available kits for red cell (RC) genotyping due to their expense and requiring extremely sophisticated instruments. Moreover, regarding complicated cases, particular typing reagents may be unavailable or insufficient. Therefore, identifying and confirming the compatibility of the blood units donated would require more time. This article aims to review the present uses of RC genotyping in Thailand and their significant contributions to transfusion practices in Asian populations. RC genotyping using PCR‐sequence‐specific primer (PCR‐SSP) and multiplex PCR (M‐PCR) has been established and used in patient and donor populations. The results of genotyping acquired by PCR‐SSP and M‐PCR were precise and in agreement with serological techniques. Predicted phenotypes of clinically significant blood group systems have been used to determine the compatibility of RC units among Thai patients having multiple antibodies. As a result, one additional advantage is the expanded storing of donated, frozen rare blood types. RC genotyping for high‐ and low‐prevalence antigens among differing Asian ethnicities requires consideration. RC genotyping employing these advanced PCR techniques could provide testing results that are both reliable and appropriate to screen suitable donor blood units in complex cases or patients presenting rare blood types. In addition, comparable strategies could be employed in other Asian populations using limited resources.
Transfusion in Sickle cell disease: best practice and understanding of its utility
Authors: Shi Patricia A. , Yazdanbakhsh Karina
Published: February 2020

Transfusion therapy remains an important treatment modality for patients with sickle cell disease (SCD). Transfusions are given not only to treat symptomatic anaemia, but also to decrease SCD‐related complications by lowering the percentage of circulating sickle red cells, thus decreasing blood viscosity and vaso‐occlusion. The strongest evidence of the effectiveness of transfusion is in primary and secondary stroke prophylaxis, where transfusion reduces the risk of overt stroke by about 90–70%, and in pre‐operative transfusion, where transfusion reduces the risk of acute chest syndrome by at least 30%. Most other indications for transfusion in SCD are based on expert opinion or less well‐controlled studies. In this brief overview, we discuss methods of transfusion, the evidence and expert opinion regarding various indications in sickle cell disease and our current pathophysiologic understanding of how transfusions may work in SCD.
Evaluation of the Attitudes of Users Towards Youth Centers in Turkey
Authors: Yılmaz Özlem , Orhan Rüstem
Published: February 2020

This is an assessment of the Youth Centers (YC) of the Ministry of Youth and Sports (MYS) in Turkey. The users evaluated the youth centers considering the physical environments as well as the activities and programs offered by the centers in educational, pedagogical, social, psychological, physiological and relaxing terms. The sample of the study consists of YC users in Diyarbakır, Kırıkkale, Kocaeli, Trabzon, and Van. A total of 561 volunteers, 359 (64%) of whom were women and 202 (36%) were men, (mean age 16-19 (38.5%)) participated in the study voluntarily. In addition to the personal information form, as the data collection tool, a scale designed by the researchers for the measurement of users’ attitudes towards youth centers was employed. The scale was developed from the “Leisure Satisfaction Scale (LSS) designed by Beard and Ragheb (1980). When the results regarding the attitudes of users towards YCs were evaluated, the highest mean was found to be in the psychological sub-factor (x = 3.84 ± 1.11). The results of the T-test analysis showed that male users evaluated the YCs more positively than female users in the physiological sub-factor (p<0,05). ANOVA and Tukey analyses were performed to see whether there were significant differences between the provinces where the research was conducted. The users in Kırıkkale and Kocaeli, in general, have more positive attitudes towards educational, social, relaxing, physiological aspects of the programs and activities and physical environments of the youth centers than those in Van and Trabzon particularly (p<0,05).
Understanding of Secondary Flows and Losses in Radial and Mixed Flow Turbines
Authors: Yang Bijie , Newton Peter , Martinez-Botas Ricardo
Published: February 2020

Radial or mixed flow turbines are very common in industrial application, spanning turbochargers, small turbines for power generation, and energy recovery systems. Secondary flows have received a limited attention in the literature, and this papers aims to fill this gap of knowledge. The secondary flow structures in mixed flow turbines are particularly complex due to its geometry, high curvature, and the appearance of Coriolis and centrifugal forces. The focus of the present work is to investigate the evolution of secondary flows and their losses in a mixed flow turbine by using an experimentally validated three-dimensional computational fluid dynamics (CFD). The flow topology is analyzed to explain the formation and evolution of flow separations at the pressure, suction, and hub surfaces. The suction surface separation is caused by centrifugal forces, and it induces the formation of a hub separation. As the inlet velocity decreases, the hub separation increases in strength. A major feature found is the pressure surface separation, located at the leading edge tip, formed due to flow incidence; as the incidence decreases, this separation extends to the hub. Losses caused by those separations as well as the tip leakage vortex are studied by calculating locally entropy generation. Results show that the tip-leakage vortex accounts for the majority of losses (60%) and renders the losses caused by suction surface and induced hub separations to be small. The presence of the more severe hub separation was also found to have a significant detrimental effect on the turbine efficiency, which increases losses on the hub and the suction surface from 40% to 65%. Pressure surface separation, however, does not vary the total amount of losses significantly but rather redistributes the losses in the blade passage.
Multidimensional Manifold Continuation for Adaptive Boundary-Value Problems
Authors: Dankowicz Harry , Wang Yuqing , Schilder Frank , Henderson Michael E.
Published: February 2020

Parameter continuation of finitely parameterized, approximate solutions to integro-differential boundary-value problems typically involves regular adaptive updates to the number and meaning of the unknowns and/or the associated constraints. Different continuation steps produce solutions with different discretizations or to formally different sets of equations. Existing general-purpose, multidimensional continuation algorithms fail to account for such differences without significant additional coding and are therefore prone to redundant coverage of the set of solutions. We describe a new algorithm, implemented in the software package coco, which overcomes this problem by characterizing the solution set in an invariant, finite dimensional, projected geometry rather than in the space of unknowns corresponding to any particular discretization. It is in this geometry that distances between solutions and angles between tangent spaces are quantified and used to construct possible directions of outward expansion. A pointwise lift identifies such directions in the projected geometry with directions of continuation in the full set of unknowns, used by a nonlinear predictor-corrector algorithm to expand into uncharted parts of the solution set. Several benchmark problems from the analysis of periodic orbits in autonomous dynamical systems are used to illustrate the theory.
A Nonlinear Reduced-Order Model of the Corpus Callosum Under Planar Coronal Excitation
Authors: Mojahed Alireza , Abderezaei Javid , Kurt Mehmet , Bergman Lawrence A. , Vakakis Alexander F.
Published: February 2020

Traumatic brain injury (TBI) is often associated with microstructural tissue damage in the brain, which results from its complex biomechanical behavior. Recent studies have shown that the deep white matter (WM) region of the human brain is susceptible to being damaged due to strain localization in that region. Motivated by these studies, in this paper, we propose a geometrically nonlinear dynamical reduced order model (ROM) to model and study the dynamics of the deep WM region of the human brain under coronal excitation. In this model, the brain hemispheres were modeled as lumped masses connected via viscoelastic links, resembling the geometry of the corpus callosum (CC). Employing system identification techniques, we determined the unknown parameters of the ROM, and ensured the accuracy of the ROM by comparing its response against the response of an advanced finite element (FE) model. Next, utilizing modal analysis techniques, we determined the energy distribution among the governing modes of vibration of the ROM and concluded that the demonstrated nonlinear behavior of the FE model might be predominantly due to the special geometry of the brain deep WM region. Furthermore, we observed that, for sufficiently high input energies, high frequency harmonics at approximately 45 Hz, were generated in the response of the CC, which, in turn, are associated with high-frequency oscillations of the CC. Such harmonics might potentially lead to strain localization in the CC. This work is a step toward understanding the brain dynamics during traumatic injury.
Understanding Laser Powder Bed Fusion Surface Roughness
Authors: Snyder Jacob C. , Thole Karen A.
Published: February 2020

Surface roughness is a well-known consequence of additive manufacturing methods, particularly powder bed fusion processes. To properly design parts for additive manufacturing, a comprehensive understanding of the inherent roughness is necessary. While many researchers have measured different surface roughness resultant from a variety of parameters in the laser powder bed fusion process, few have succeeded in determining causal relationships due to the large number of variables at play. To assist the community in understanding the roughness in laser powder bed fusion processes, this study explored several studies from the literature to identify common trends and discrepancies amongst roughness data. Then, an experimental study was carried out to explore the influence of certain process parameters on surface roughness. Through these comparisons, certain local and global roughness trends have been identified and discussed, as well as a new framework for considering the effect of process parameters on surface roughness.
An Experimental Investigation of Pressure Drop During Partial Condensation of Low Pressure Steam
Authors: du Plessis Jacques , Owen Michael
Published: February 2020

As direct dry-cooling systems are becoming more popular for thermal power plants, there is a demand to increase the flexibility of the application and performance of these cooling systems. A novel hybrid (dry/wet) dephlegmator (HDWD) cooling system is being developed, and at this stage in the development of the HDWD, the performance analysis and optimization of the HDWD is currently subject to uncertainties in a number of parameters. One of the parameters is the confidence in the correlations to predict the steam-side pressure drop over the wide range of full to partial condensation conditions expected in the system as a result of the design. This study makes use of an experimental apparatus to measure steam pressure drop over a range of partial to full condensation inside a circular horizontal tube. The experiment is conducted by measuring the steam flow and steam pressure drop in a horizontal primary condenser tube with the presence of a secondary condenser tube. The primary condenser has a tube length of 2.5 m and an inside tube diameter of 19.3 mm similar to the proposed HDWD design. Existing correlations for pressure drop in condensing flow are compared with the results to assess the applicability of the correlations for the HDWD case. It was found that the correlation of Lockhart and Martinelli’s with the Chisholm parameter fits the experimental data the best with a mean error of ±15.6%. A parametric study also indicated that there is a prominent increase in the frictional pressure drop at low partial condensation ratios (i.e., high steam through flow) as expected with wave drag at the vapor and condensate interface due to the difference in velocity.
Production Performance Analysis for Multi-Branched Horizontal Wells in Composite Coal Bed Methane Reservoir Considering Stress Sensitivity
Authors: Jiang Ruizhong , Liu Xiuwei , Cui Yongzheng , Wang Xing , Gao Yue , Mao Nianyu , Yan Xinyuan
Published: February 2020

Coal bed methane (CBM) significantly contributes to unconventional energy resources. With the development of the drilling technology, multi-branched horizontal wells (MBHWs) have been put into the exploitation of CBM. In this paper, a semi-analytical mathematical model is introduced to study the production characteristics of MBHWs in the composite CBM reservoir. Stress sensitivity, composite reservoir, and complex seepage mechanisms (desorption, diffusion, and Darcy flow) are taken into consideration. Through Pedrosa transformation, Perturbation transformation, Laplace transformation, Finite cosine transformation, element discretization, superposition principle, and Stehfest numerical inversion, pseudo-pressure dynamic curves and production decline curves are plotted and 13 flow regimes are divided. Then, the sensitivity analysis of related parameters is conducted to study the influences of these parameters based on these two type curves. Model verification and field application are introduced which shows that the model is reliable. The model proposed in this paper and relevant results analysis can provide some significant guidance for a better understanding of the production behavior of MBHWs in the composite CBM reservoir.
Maternal gut microbiota in pregnancy influences offspring metabolic phenotype in mice
Authors: Kimura Ikuo , Miyamoto Junki , Ohue-Kitano Ryuji , Watanabe Keita , Yamada Takahiro , Onuki Masayoshi , Aoki Ryo , Isobe Yosuke , Kashihara Daiji , Inoue Daisuke , Inaba Akihiko , Takamura Yuta , Taira Satsuki , Kumaki Shunsuke , Watanabe Masaki , Ito Masato , Nakagawa Fumiyuki , Irie Junichiro , Kakuta Hiroki , Shinohara Masakazu , Iwatsuki Ken , Tsujimoto Gozoh , Ohno Hiroaki , Arita Makoto , Itoh Hiroshi , Hase Koji
Published: February 2020

Mouse mothers transfer metabolic mode

Obesity and metabolic diseases tend to go together, and humans who become obese are also prone to type 2 diabetes and cardiovascular problems. Starting with the observation that offspring of germ-free mice tended to become obese on high-fat diets, Kimura
et al.
investigated how the presence of the microbiota might be protective in mice (see the Perspective by Ferguson). Short-chain fatty acids (SCFAs) from the microbiota are known to suppress insulin signaling and reduce fat deposition in adipocytes. Further experiments showed that SCFAs in the bloodstream were able to pass from a non–germ-free mother's gut microbiota across the placenta and into the developing embryos. The authors found that in the embryos, the SCFA propionate mediates not only insulin levels through GPR43 signaling but also sympathetic nervous system development through GPR41 signaling. A high-fiber diet promoted propionate production from the maternal microbiota, and maternal antibiotic treatment resulted in obese-prone offspring.

Science
, this issue p.
eaaw8429
; see also p.
978
Distinct sensitivity to spectrotemporal modulation supports brain asymmetry for speech and melody
Authors: Albouy Philippe , Benjamin Lucas , Morillon Benjamin , Zatorre Robert J.
Published: February 2020

Speech versus music in the brain

To what extent does the perception of speech and music depend on different mechanisms in the human brain? What is the anatomical basis underlying this specialization? Albouy
et al.
created a corpus of a cappella songs that contain both speech (semantic) and music (melodic) information and degraded each stimulus selectively in either the temporal or spectral domain. Degradation of temporal information impaired speech recognition but not melody recognition, whereas degradation of spectral information impaired melody recognition but not speech recognition. Brain scanning revealed a right-left asymmetry for speech and music. Classification of speech content occurred exclusively in the left auditory cortex, whereas classification of melodic content occurred only in the right auditory cortex.

Science
, this issue p.
1043
Aminoalkyl radicals as halogen-atom transfer agents for activation of alkyl and aryl halides
Authors: Constantin Timothée , Zanini Margherita , Regni Alessio , Sheikh Nadeem S. , Juliá Fabio , Leonori Daniele
Published: February 2020

Amines as a gateway to alkyl radicals

In recent years, photoredox catalysis driven by blue light has often been used to oxidize carbon centers adjacent to nitrogen. Constantin
et al.
now show that these aminoalkyl radicals can, in turn, conveniently strip iodine atoms from a variety of alkyl carbons. The new alkyl radicals that result readily undergo deuteration and couplings such as alkylation, allylation, and olefination. The upshot is that simple amines can replace more hazardous conventional reagents such as trialkyltin compounds in the homolytic activation and functionalization of halocarbons.

Science
, this issue p.
1021
Assessing Animal Models of Bacterial Pneumonia Used in Investigational New Drug Applications for the Treatment of Bacterial Pneumonia
Authors: Waack Ursula , Weinstein Edward A. , Farley John J.
Published: February 2020

Animal models of bacterial infection have been widely used to explore the
in vivo
activity of antibacterial drugs. These data are often submitted to the U.S. Food and Drug Administration to support human use in an investigational new drug application (IND). To better understand the range and scientific use of animal models in regulatory submissions, a database was created surveying recent pneumonia models submitted as part of IND application packages. The IND studies were compared to animal models of bacterial pneumonia published in the scientific literature over the same period of time.
Putative β-Barrel Outer Membrane Proteins of the Bovine Digital Dermatitis-Associated Treponemes: Identification, Functional Characterization, and Immunogenicity
Authors: Staton G. J. , Carter S. D. , Ainsworth S. , Mullin J. , Smith R. F. , Evans N. J.
Published: February 2020

Bovine digital dermatitis (BDD), an infectious disease of the bovine foot with a predominant treponemal etiology, is a leading cause of lameness in dairy and beef herds worldwide. BDD is poorly responsive to antimicrobial therapy and exhibits a relapsing clinical course; an effective vaccine is therefore urgently sought. Using a reverse vaccinology approach, the present study surveyed the genomes of the three BDD-associatedTreponemaphylogroups for putative β-barrel outer membrane proteins and considered their potential as vaccine candidates.
Extensive-disease small cell lung cancer, multiple relapses, five lines of therapy and more than 10-year survival
Authors: Singh Pawan Kumar , Shrestha Deepa Kumari , Singh Navneet , Gupta Nalini
Published: February 2020

Small cell lung cancer (SCLC) accounts for nearly 18% of lung cancer cases. Most of the patients of SCLC are not surgical candidates, due to advanced stage at presentation hence only viable options are chemotherapy and radiotherapy. Long-term survival in SCLC is extremely rare due to relapses and comorbidities. Ten-year survival has never been reported in cases with extensive disease at presentation and history of relapses. Here we are describing a case of extensive disease SCLC who has survived multiple relapses and has received five lines of systemic therapy apart from radiation and palliative care. This case emphasises on the need of active and strict disease surveillance at each follow-up.
High-output cardiac failure secondary to high-output arteriovenous fistula: investigations, management and definitive treatment
Authors: Hartley James Leon , Sharma Asheesh , Taha Lamis , Hestletine Thomas
Published: February 2020

A 32 year-old woman was admitted to our institution with progressive dyspnoea. Her medical history was notable for end-stage renal failure secondary to chronic pyelonephritis, and she had undergone a cadaveric renal transplant in 2010. This had been preceded by haemodialysis treatment via a radiocephalic arteriovenous fistula. Her diagnostic evaluation was remarkable for pulmonary hypertension. A subsequent doppler ultrasound of her arteriovenous fistula revealed a blood flow of 3 L/min. This is consistent with a high output fistula. Echocardiography demonstrated an improvement in pulmonary artery pressure with occlusion of the fistula. After multidisciplinary discussion, a decision was made to surgically tie off her fistula. The patient experienced immediate improvement in her shortness of breath along with resolution of pulmonary hypertension on echocardiography. This case highlights the rare complication of high output cardiac failure from a dialysis fistula and its successful surgical management.
Clinical characteristics and outcomes of patients with end-stage renal disease hospitalized with diabetes ketoacidosis
Authors: Galindo Rodolfo J , Pasquel Francisco J , Fayfman Maya , Tsegka Katerina , Dhruv Neil , Cardona Saumeth , Wang Heqiong , Vellanki Priyathama , Umpierrez Guillermo E
Published: February 2020

Introduction

There is limited evidence to guide management in patients with end-stage renal disease (ESRD) on chronic hemodialysis admitted with diabetes ketoacidosis. Thus, we investigated the clinical characteristics and outcomes of patients with ESRD admitted with diabetic ketoacidosis (DKA).

Methods

In this observational study, we used International Classification of Diseases Ninth/Tenth Revision codes to identify adult (aged 18–80 years) patients admitted to Emory University Hospitals between 1 January 2006 and 31 December 2016. DKA and ESRD diagnoses were confirmed by reviewing medical records and by admission laboratory results.

Results

Among 307 patients with DKA meeting the inclusion and exclusion criteria, 22.1% (n: 68) had ESRD on hemodialysis and 77.9% (n: 239) had preserved renal function (estimated glomerular filtration rate >60 mL/min/1.73 m2). Compared with patients with preserved renal function, the admission blood glucose was higher (804.5±362.6 mg/dL vs 472.5±137.7 mg/dL) and the mean hemoglobin A1c was lower (9.6%±2.1 vs 12.0%±2.5) in patients with DKA and ESRD, both p<0.001. The rates of hypoglycemia <70 mg/dL (34% vs 14%, p=0.002) and <54 mg/dL (13% vs 5%, p=0.04) were higher in the ESRD group. During hospitalization, more patients with ESRD develop volume overload (28% vs 3%, p<0.001) and require mechanical ventilation (24% vs 3%, p=<0.001). There were no differences in hospital mortality (3% vs 0%, p=0.21), but length of stay (median 7.0 vs 3.0 days, p<0.001) was longer in the ESRD cohort. After adjusting for multiple covariates, patients with DKA and ESRD have higher odds of hypoglycemia (OR 3.3, 95% CI 1.51 to 7.21, p=0.003) and volume overload (OR 4.22, 95% CI 1.37 to 13.05, p=0.01) compared with patients with DKA with preserved renal function.

Conclusions

Patients with DKA and ESRD on chronic hemodialysis had worse clinical outcomes including higher rates of hypoglycemia, volume overload, need for mechanical ventilation and longer length of stay, compared with patients with preserved kidney function.
Habitual snoring, adiposity measures and risk of type 2 diabetes in 0.5 million Chinese adults: a 10-year cohort
Authors: Wei Yuxia , Zheng Bang , Fan Junning , Lv Jun , Guo Yu , Bian Zheng , Du Huaidong , Yang Ling , Chen Yiping , Chen Jianxin , Zhong Xunfu , Chen Junshi , Chen Zhengming , Yu Canqing , Li Liming
Published: February 2020

Objectives

The present study aimed to examine whether habitual snoring was independently associated with risk of type 2 diabetes among Chinese adults, and to assess the role that adiposity measures play in the snoring–diabetes association, as well as to evaluate the joint influence of snoring and adiposity measures on diabetes.

Research design and methods

The China Kadoorie Biobank study recruited 512 715 adults aged 30–79 years from 10 regions in China during 2004 and 2008. Data from 482 413 participants without baseline diabetes were analyzed in the present study. Autoregressive cross-lagged panel analysis was used to assess the longitudinal relationship between adiposity measures and habitual snoring. Cox proportional hazards models were used to examine the association between habitual snoring and diabetes risk.

Results

Both higher body mass index and waist circumference were associated with higher risks of subsequent habitual snoring, whereas no reverse association was detected. A total of 16 479 type 2 diabetes cases were observed during a 10-year follow-up. Habitual snoring was independently associated with 12% (95% CI 6% to 18%) and 14% (95% CI 9% to 19%) higher risks of diabetes among men and women, respectively. Habitual snorers who had general obesity or central obesity were about twice as likely to develop diabetes as non-snorers at the lowest levels of adiposity measures.

Conclusion

Habitual snoring was independently associated with a higher risk of type 2 diabetes among Chinese adults. It is important to maintain both a healthy weight and a normal waist circumference to prevent or alleviate habitual snoring and ultimately prevent diabetes among Chinese adults.