bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thyroid Hormone Supplementation and All‐Cause Mortality in Community‐Dwelling Older Adults: Results from the Baltimore Longitudinal Study of Aging
Authors: Abbey Enoch J. , McGready John , Ferrucci Luigi , Simonsick Eleanor M. , Mammen Jennifer S.R. 
Published: January 2021

BackgroundAlthough elevated thyrotropin (TSH) is common in older adults, controversy exists over what degree of elevation should be treated with thyroid hormone supplements. Isolated, elevated TSH in this population can be consistent with aging‐related adaptations rather than indicative of primary thyroid disease, raising the possibility that thyroid hormone replacement may be harmful.ObjectivesDetermine the association between all‐cause mortality and levothyroxine use among older adults.DesignLongitudinal observational study.SettingBaltimore Longitudinal Study of Aging.ParticipantsOne thousand two hundred and fifty eight community dwelling adult participants aged 65+ with an average of 9 years of follow up.MeasurementsThyroid and pituitary hormone levels and thyroid hormone supplementation were determined at each visit. Incident rate ratios (IRR) for all‐cause mortality were calculated using time‐dependent Poisson regression models to accommodate the varying start times. To isolate the effects of hormone replacement from its effects on TSH, the association between treatment and all‐cause mortality was analyzed in participants with stable thyroid function status throughout follow‐up (N = 638).ResultsThyroid hormone supplementation was not associated with a significant increase all‐cause mortality in the subsequent year in the fully adjusted model (IRR = 1.40, 95% confidence interval (CI) = 0.93–2.12). In a stratified analysis of euthyroid participants, thyroid hormone use was associated with significantly greater mortality, with an adjusted IRR = 1.81 (95% CI = 1.10–2.98).ConclusionThe increased mortality associated with thyroid hormone use among the subclass of euthyroid community dwelling older adults is consistent with a model in which TSH elevation can result from a variety of underlying pathophysiologic processes, not all of which should be treated with thyroid hormone supplementation. Clinicians should consider overall clinical status when interpreting an isolated elevated TSH in older adults.
Circuit selectivity in drug versus natural reward seeking behaviors
Authors: Nall Rusty W. , Heinsbroek Jasper A. , Nentwig Todd B. , Kalivas Peter W. , Bobadilla Ana‐Clara 
Published: January 2021

AbstractSubstance use disorder (SUD) is characterized, in part by behavior biased toward drug use and away from natural sources of reward (e.g., social interaction, food, sex). The neurobiological underpinnings of SUDs reveal distinct brain regions where neuronal activity is necessary for the manifestation of SUD‐characteristic behaviors. Studies that specifically examine how these regions are involved in behaviors motivated by drug versus natural reward allow determinations of which regions are necessary for regulating seeking of both reward types, and appraisals of novel SUD therapies for off‐target effects on behaviors motivated by natural reward. Here, we evaluate studies directly comparing regulatory roles for specific brain regions in drug versus natural reward. While it is clear that many regions drive behaviors motivated by all reward types, based on the literature reviewed we propose a set of interconnected regions that become necessary for behaviors motivated by drug, but not natural rewards. The circuitry is selectively necessary for drug seeking includes an Action/Reward subcircuit, comprising nucleus accumbens, ventral pallidum, and ventral tegmental area, a Prefrontal subcircuit comprising prelimbic, infralimbic, and insular cortices, a Stress subcircuit comprising the central nucleus of the amygdala and the bed nucleus of the stria terminalis, and a Diencephalon circuit including lateral hypothalamus. Evidence was mixed for nucleus accumbens shell, insular cortex, and ventral pallidum. Studies for all other brain nuclei reviewed supported a necessary role in regulating both drug and natural reward seeking. Finally, we discuss emerging strategies to further disambiguate the necessity of brain regions in drug‐ versus natural reward‐associated behaviors.
image
Linking changes in chlorophyll a fluorescence with drought stress susceptibility in mung bean [Vigna radiata (L.) Wilczek]
Authors: Bano Hussan , Athar Habib‐ur‐Rehman , Zafar Zafar Ullah , Kalaji Hazem M. , Ashraf Muhammad 
Published: January 2021

AbstractIn the present study, the mung bean cv. NM‐13‐1Tol was selected as drought‐tolerant and NM‐54Sens as drought‐sensitive. The effects of progressive drought (16 days) on the photosystem II (PSII) activity was assessed using OJIP and JIP‐test in the selected two mung bean cultivars differing in drought tolerance. Drought stress reduced the relative water content to 70% (at threshold) and 62% (below the threshold) in cv.NM‐13‐1Tol and NM‐54sens, respectively. The greater reduction in quantum yield of PSII in cv.NM‐54sens due to drought stress was due to PSII photodamage. Raw OJIP induction curves and Fo and Fm normalised curves showed that significant changes in fluorescence occurred at the O, J, I and P steps only in cv. NM‐54sens. Double normalised differential kinetics indicated adverse effects at the antennae, oxygen‐evolving complex and intersystem electron acceptors in cv.NM54sens. Moreover, JIP‐test analysis showed that drought stress caused a greater decrease in performance index (PIABS) in cv.NM‐54sens as compared to that in cv. NM‐13‐1Tol, which is associated with an increase in Vj, rate of accumulation of closed reaction centres (Mo), energy fluxes for absorption (ABS/RC), trapping (TRo/RC), electron transport (ETo/RC), and dissipation of absorbed energy as heat (DIo/RC). In conclusion, two‐week drought stress reduced the RWC below the threshold in cv.NM54sens, which resulted in damages at the donor and acceptor sides of PSII. However, cv.NM‐13‐1Tol somehow maintained the RWC around the threshold and thus protected PSII. Of various JIP‐test parameters, PIABS, Fv/Fm, Vj and Mo are key indicators of drought stress tolerance in mung bean cultivars.
Crosstalk between phytohormones and secondary metabolites in the drought stress tolerance of crop plants: A review
Authors: Jogawat Abhimanyu , Yadav Bindu , Chhaya  , Lakra Nita , Singh Amit Kumar , Narayan Om Prakash 
Published: January 2021

AbstractDrought stress negatively affects crop performance and weakens global food security. It triggers the activation of downstream pathways, mainly through phytohormones homeostasis and their signaling networks, which further initiate the biosynthesis of secondary metabolites (SMs). Roots sense drought stress, the signal travels to the above‐ground tissues to induce systemic phytohormones signaling. The systemic signals further trigger the biosynthesis of SMs and stomatal closure to prevent water loss. SMs primarily scavenge reactive oxygen species (ROS) to protect plants from lipid peroxidation and also perform additional defense‐related functions. Moreover, drought‐induced volatile SMs can alert the plant tissues to perform drought stress mitigating functions in plants. Other phytohormone‐induced stress responses include cell wall and cuticle thickening, root and leaf morphology alteration, and anatomical changes of roots, stems, and leaves, which in turn minimize the oxidative stress, water loss, and other adverse effects of drought. Exogenous applications of phytohormones and genetic engineering of phytohormones signaling and biosynthesis pathways mitigate the drought stress effects. Direct modulation of the SMs biosynthetic pathway genes or indirect via phytohormones' regulation provides drought tolerance. Thus, phytohormones and SMs play key roles in plant development under the drought stress environment in crop plants.
Phylogeny and revision of the ‘Cubitermes complex’ termites (Termitidae: Cubitermitinae)
Authors: Hellemans Simon , Deligne Jean , Roisin Yves , Josens Guy 
Published: January 2021

AbstractThe phylogeny of the genus Cubitermes Wasmann was reconstructed using two mitochondrial genes (COI and COII) and a fragment of the nuclear 28S rDNA, including samples of Apilitermes Holmgren, Crenetermes Silvestri, Megagnathotermes Silvestri and Thoracotermes Wasmann. Based on our analyses, we recovered these genera within a paraphyletic Cubitermes clade. Cubitermes species are distributed between five main clades, highly reflective of their enteric valve armatures (EVAs). Consequently, Cubitermes is here divided into five monophyletic genera based on phylogenetic analyses and EVAs: Cubitermes (sensu stricto), Isognathotermes Sjöstedt, Nitiditermes Emerson, Polyspathotermes Josens & Deligne, gen.n., and Ternicubitermes Josens & Deligne, gen.n. Moreover, the two species of Megagnathotermes included in this study, exhibiting different EVAs, are phylogenetically distant: M. katangensis Sjöstedt belongs in the genus Polyspathotermes, while M. notandus Silvestri remains as a monotypic genus. During the evolution of the Cubitermes complex, sclerotized EVA spatulae appeared twice independently: three or six spatulae in Polyspathotermes (sulcifrons and oblectatus patterns) and two jaw‐like spatulae in Nitiditermes (sankurensis pattern), which is absent in some species (oculatus pattern). Zoobank registration:
http://zoobank.org/urn:lsid:zoobank.org:pub:576AAFF8‐63C6‐4962‐A8F5‐75C9317AEA7B.
Wear Behavior of TiB2/GNPs and B4C/GNPs Reinforced AA6061 Matrix Composites
Authors: Polat Safa , Sun Yavuz , C¸evik Engin 
Published: January 2021

AbstractIn this study, it was aimed to investigate the effects of reinforcements used for improving the thermal properties of AA6061 alloy on wear resistance. For this purpose, AA6061 matrix composites were produced by pressure infiltration method using ceramic microparticles (TiB2 and B4C) and graphene nanoparticles (GNPs). The produced composites were first characterized by porosity measurement, X-ray diffraction (XRD), and scanning electron microscopy (SEM) analysis. Then, the wear behavior was examined under three different loads (20–40–60 N) with the reciprocating ball on the flat method in a dry environment. Specific wear-rates were calculated according to the Archard principle by measuring the depth and width of the traces after tests with a profilometer. Wearing mechanisms were determined with the help of optical and microstructure images. According to the obtained results, it was found that B4C + GNPs reinforced samples were more resistant to abrasion at low loads, but TiB2 + GNPs reinforced samples were higher at higher loads.
Louver Slot Cooling and Full-Coverage Film Cooling With a Combination Internal Coolant Supply
Authors: Click Austin , Ligrani Phillip M. , Hockensmith Maggie , Knox Joseph , Larson Chandler , Fairbanks Avery , Liberatore Federico , Patel Rajeshriben , Ho Yin-Hsiang 
Published: January 2021

Abstract
Within the present investigation, a louver slot is employed upstream of an array full-coverage film cooling holes. Cooling air is supplied using a combination arrangement, with cross-flow and impingement together. The louver consists of a row of film cooling holes, contained within a specially designed device that concentrates and directs the coolant from a slot, so that it then advects as a layer downstream along the test surface. This louver-supplied coolant is then supplemented by coolant which emerges from different rows of downstream film cooling holes. The same coolant supply passage is employed for the louver row of holes, as well as for the film cooling holes, such that different louver and film cooling mass flowrates are set by different hole diameters for the two different types of cooling holes. The results are different from data provided by past investigations, because of the use and arrangement of the louver slot, and because of the unique coolant supply configurations. The experimental results are given for mainstream Reynolds numbers from 107,000 to 114,000. Full-coverage blowing ratios are constant with streamwise location along the test surface and range from 3.68 to 5.70. Corresponding louver slot blowing ratios then range from 1.72 to 2.65. Provided are heat transfer coefficient and adiabatic effectiveness distributions, which are measured along the mainstream side of the test plate. Both types of data show less variation with streamwise development location, relative to results obtained without a louver employed, when examined at the same approximate effective blowing ratio, mainstream Reynolds number, cross-flow Reynolds number, and impingement jet Reynolds number. When compared at the same effective blowing ratio or the same impingement jet Reynolds number, spanwise-averaged heat transfer coefficients are consistently lower, especially for the downstream regions of the test plate, when the louver is utilized. With the same type of comparisons, the presence of the louver slot results in significantly higher values of adiabatic film cooling effectiveness (spanwise-averaged), particularly at and near the upstream portions of the test plate. With such characteristics, dramatic increases in thermal protection are provided by the presence of the louver slot, the magnitudes of which vary with the experimental condition and test surface location.
Development and Performance of Roof-Based Building-Integrated Photovoltaic-Thermal Systems: A Review
Authors: Cheng Xu , Zou Zhijun , Yu Guoqing , Ma Guobin , Ye Hai , Li Yilin , Liu Hongzhi 
Published: January 2021

Abstract
A building-integrated photovoltaic-thermal (BIPVT) system integrates building envelope and photovoltaic-thermal collectors to produce electricity and heat. In this paper, the electrical and thermal performance of roof-based BIPVT systems developed in the recent two decades and their effects on heating and cooling load of the building are reviewed. According to the use of thermal energy from the photovoltaic (PV) panels, the roof-based BIPVT are classified into three classes: cooling of PV, air heating, and water heating. Each class is further divided into several types according to the designs of the integrated PV roofs. Compared with BIPV systems, the total efficiency of most BIPVT systems is significantly improved. However, the decrease in electricity output and adverse impact on the indoor environment is also found for some designs of BIPVT systems in some climates. The advantages and disadvantages of various designs are discussed. Issues to be further studied in the future are also provided in this review.
A Cable-Driven Parallel Robot With Full-Circle End-Effector Rotations
Authors: Métillon Marceau , Cardou Philippe , Subrin Kévin , Charron Camilo , Caro Stéphane 
Published: January 2021

Abstract
Cable-driven parallel robots (CDPRs) offer high payload capacities, large translational workspace and high dynamic performances. The rigid base frame of the CDPR is connected in parallel to the moving platform using cables. However, their orientation workspace is usually limited due to cable/cable and cable/moving platform collisions. This paper deals with the design, modelling and prototyping of a hybrid robot. This robot, which is composed of a CDPR mounted in series with a Parallel Spherical Wrist (PSW), has both a large translational workspace and an unlimited orientation workspace. It should be noted that the six-degrees-of-freedom (DOF) motions of the moving platform of the CDPR, namely, the base of the PSW, and the three-DOF motion of the PSW are actuated by means of eight actuators fixed to the base. As a consequence, the overall system is underactuated, and its total mass and inertia in motion is reduced.
Experimental and Numerical Analysis of the Powder Flow in a Multi-Channel Coaxial Nozzle of a Direct Metal Deposition System
Authors: Pant Piyush , Chatterjee Dipankar , Samanta Sudip Kumar , Lohar Aditya Kumar 
Published: January 2021

Abstract
The work explores the powder transport process, using numerical simulation to address the dynamics of the powder flow in an in-house built multi-channel coaxial nozzle of a direct metal deposition (DMD) system. The fluid turbulence is handled by the standard k–ɛ and k–ω turbulence models, and the results are compared in order to predict their suitability. An image-based technique using CMOS camera is adopted to determine the powder flow characteristics. The model is validated with the in-house experimental results and verified available results in the literature. The findings of this work confirms the application of the k–ω model for powder gas flow investigations in blown powder additive manufacturing (AM) processes due to its better predictive capability. The proposed model will assist in simulating the direct metal deposition process.
Sizing and Operation of a Hybrid Energy Plant Composed of Industrial Gas Turbines, Renewable Energy Systems, and Energy Storage Technologies
Authors: Bahlawan Hilal , Gambarotta Agostino , Losi Enzo , Manservigi Lucrezia , Morini Mirko , Spina Pier Ruggero , Venturini Mauro 
Published: January 2021

Abstract
Hybrid energy plants (HEPs), which include both fossil fuel technologies and renewable energy systems, can provide an important step toward a sustainable energy supply. In fact, the hybridization of renewable energy systems with gas turbines (GTs), which are fed by fossil fuels allows an acceptable compromise, so that high fossil fuel efficiency and high share of renewables can be potentially achieved. Moreover, electrical and thermal energy storage systems increase the flexibility of the energy plant and effectively manage the variability of energy production and demand. This paper investigates the optimal sizing of a HEP, which combines an industrial GT, renewable energy systems, and energy storage technologies. The considered renewable energy system is a photovoltaic system (PV), while the energy storage technologies are electrical energy storage and thermal energy storage. Moreover, a compression chiller and a gas boiler (GB) are also considered. For this purpose, the load profiles of electricity, heating, and cooling during a whole year are taken into account for the case study of the Campus of the University of Parma (Italy). The sizing optimization problem of the different technologies composing the HEP is solved by using a genetic algorithm, with the goal of minimizing the primary energy consumption (PEC). Moreover, different operation strategies are analyzed and compared so that plant operation is also optimized. The results demonstrate that the optimal sizing of the HEP, coupled with the optimized operation strategy, allows high average cogeneration efficiency (up to 84%), thus minimizing PEC.
Numerical Study of Tip Leakage Vortex Around a NACA0009 Hydrofoil
Authors: Bi Zhen , Shao Xueming , Zhang Lingxin 
Published: January 2021

Abstract
In the tip clearance flow, the dominant vortex is the tip leakage vortex (TLV), which has a significant impact on the hydraulic and cavitation performance of axial flow machineries. In order to reveal the impact mechanism of the gap size on the TLV, gap flows with two gap sizes, i.e., τ=0.2 (2 mm) and τ=1.0 (10 mm), are numerically investigated. A NACA0009 hydrofoil is selected to create the gap flow, with an incoming velocity of 10 m/s and an attack angle of 10 deg. The results show that the two flow cases are significantly different in terms of vortex feature and the leakage flow distribution. In the small gap, a type of jet-pattern flow appears, whereas a type of rolling-pattern flow passes over the large gap. The vertical velocity gradient of the leakage flow has a decisive influence on the TLV trajectory. In addition, for the large gap, the axial velocity in the vortex center exceeds the incoming flow. This jet-like state of axial velocity can be maintained for a long distance, making the vortex more stable. However, the axial velocity in the case of τ=0.2 cannot stay at the jet-like state and rapidly switches to a wake-like state.
A Modified Chezy Formula for One-Dimensional Unsteady Frictional Resistance in Open Channel Flow
Authors: Zhou Junwei , Bao Weimin , Tick Geoffrey R. , Moftakhari Hamed , Li Yu , Cheng Li 
Published: January 2021

Abstract
It has been observed in literature that for unsteady flow conditions the one-to-one relationships between flow depth, cross-sectional averaged velocity, and frictional resistance as determined from steady uniform flow cases may not be appropriate for these more complex flow systems. Thus, a general friction resistance formula needs to be modified through the addition of new descriptive terms to account for flow unsteadiness, in order to eliminate errors due to uniform and steady-flow assumptions. An extended Chezy formula incorporating both time and space partial derivatives of hydraulic parameters was developed using dimensional analysis to investigate the relationship between flow unsteadiness and friction resistance. Results show that the proposed formula performs better than the traditional Chezy formula for simulating real hydrograph cases whereby both formula coefficients are individually identified for each flood event and coefficients are predetermined using other flood events as calibration cases. Although the extended Chezy formula as well as the original Chezy formula perform worse with the increasing degree of flow unsteadiness, its results are less dramatically affected by unsteadiness intensity, thereby improving estimations of flood routing. As a result, it tends to perform much better than traditional Chezy formula for severe flood events. Under more complex conditions whereby peak flooding events may occur predominantly under unsteady flow, the extended Chezy model may provide as a valuable tool for researchers, practitioners, and water managers for assessing and predicting impacts for flooding and for the development of more appropriate mitigation strategies and more accurate risk assessments.
On the Vortical Characteristics of Horn-Like Vortices in Stator Corner Separation Flow in an Axial Flow Pump
Authors: Wang Chaoyue , Wang Fujun , Xie Lihua , Wang Benhong , Yao Zhifeng , Xiao Ruofu 
Published: January 2021

Abstract
The phenomenon of horn-like vortex in stator corner separation flow in an axial flow pump was first reported by Wang et al. (2020, “Investigation on the Horn-Like Vortices in Stator Corner Separation Flow in an Axial Flow Pump,” ASME J. Fluids Eng., 142(7), p. 071208), and the associated external features were preliminarily presented. However, internal vortical characteristics of horn-like vortices, including the distributions of swirling strength, the deformation mechanism of vortex tube and the correlation with pressure fluctuation surge, are not revealed. In this paper, the newly developed vorticity decomposition approach is introduced, and thus more novel quantitative results are provided for the physics of horn-like vortex evolution in an axial flow pump. First, the distributions of absolute swirling strength, relative swirling strength and Liutex spectrum are presented to outline the vortical features of the horn-like vortex fields. Second, the deformation mechanism of the horn-like vortex tube is revealed. It is found that the horn-like vortex spatial evolution can be described by the deformation terms (Liutex stretching term, Liutex dilatation term, and curl term of the pseudo-Lamb vector) controlling the Liutex transport process. These terms constantly act on the horn-like vortex tube in an almost independent way, causing its continuous deformations in the transit process. Third, the quantitative correlation between horn-like vortex transit and pressure fluctuation surge is given. It is proved that periodic vortex transit can cause severe pressure fluctuation that is much larger than that induced by rotor–stator interaction. From multiple perspectives, a clearer evolution process of the horn-like vortex is outlined, which is conducive to controlling the corner separation flows and improving the stability of large-capacity and low-head pumping stations.