bluuebunny/crossref_metadata_2025_split huggingface dataset:
The CRP‐family transcriptional regulator DevH regulates expression of heterocyst‐specific genes at the later stage of differentiation in the cyanobacterium Anabaena sp. strain PCC 7120
Authors: Kurio Yohei , Koike Yosuke , Kanesaki Yu , Watanabe Satoru , Ehira Shigeki 
Published: June 2020

AbstractHeterocysts are terminally differentiated cells of filamentous cyanobacteria, which are specialized for nitrogen fixation. Because nitrogenase is easily inactivated by oxygen, the intracellular environment of heterocysts is kept microoxic. In heterocysts, the oxygen‐evolving photosystem II is inactivated, a heterocyst‐specific envelope with an outer polysaccharide layer and an inner glycolipid layer is formed to limit oxygen entry, and oxygen consumption is activated. Heterocyst differentiation, which is accompanied by drastic morphological and physiological changes, requires strictly controlled gene expression systems. Here, we investigated the functions of a CRP‐family transcriptional regulator, DevH, in the process of heterocyst differentiation. A devH‐knockdown strain, devH‐kd, was created by replacing the original promoter with the gifA promoter, which is repressed during heterocyst differentiation. Although devH‐kd formed morphologically distinct cells with the heterocyst envelope polysaccharide layer, it was unable to grow diazotrophically. Genes involved in construction of the microoxic environment, such as cox operons and the hgl island, were not upregulated in devH‐kd. Moreover, expression of the nif gene cluster was completely abolished. Although CnfR was expressed in devH‐kd, the nif gene cluster was not induced even under microoxic conditions. Thus, DevH is necessary for the establishment of a microoxic environment and induction of nitrogenase in heterocysts.
A novel mutation in ABCD1 gene in a Filipino patient with adult‐onset X‐linked ALD
Authors: Porto Kristine Joyce , Matsukawa Takashi , Ishiura Hiroyuki , Mitsui Jun , Matic Alexandria , Yu Justine Megan , Dominguez Jacqueline , Damian Ludwig , Toda Tatsushi , Tsuji Shoji 
Published: June 2020

AbstractX‐linked adrenoleukodystrophy (X‐ALD) is the most common peroxisomal disorder caused by a mutation in ABCD1 gene. We present a 36‐year‐old, Filipino male, diagnosed with adrenomyeloneuropathy with later development of adult‐onset cerebral form of X‐ALD with a novel mutation c.2012T > C (p.Leu671Pro) in exon 10 of the ABCD1 gene. It is important that clinicians have high clinical suspicion because of the proven clinical efficacy of hematopoietic stem cell transplantation performed in the early stage of the disease.
Is the Kok effect a respiratory phenomenon? Metabolic insight using 13C labeling in Helianthus annuus leaves
Authors: Gauthier Paul P. G. , Saenz Natalie , Griffin Kevin L. , Way Danielle , Tcherkez Guillaume 
Published: June 2020

Summary

The Kok effect is a well‐known phenomenon in which the quantum yield of photosynthesis changes abruptly at low light. This effect has often been interpreted as a shift in leaf respiratory metabolism and thus used widely to measure day respiration. However, there is still no formal evidence that the Kok effect has a respiratory origin.

Here, both gas exchange and isotopic labeling were carried out on sunflower leaves, using glucose that was 13C‐enriched at specific C‐atom positions. Position‐specific decarboxylation measurements and NMR analysis of metabolites were used to trace the fate of C‐atoms in metabolism.

Decarboxylation rates were significant at low light (including above the Kok break point) and increased with decreasing irradiance below 100 µmol photons m−2 s−1. The variation in several metabolite pools such as malate, fumarate or citrate, and flux calculations suggest the involvement of several decarboxylating pathways in the Kok effect, including the malic enzyme.

Our results show that day respiratory CO2 evolution plays an important role in the Kok effect. However, the increase in the apparent quantum yield of photosynthesis below the Kok break point is also probably related to malate metabolism, which participates in maintaining photosynthetic linear electron flow.
Systemic drug photosensitivity—Culprits, impact and investigation in 122 patients
Authors: Alrashidi Amirah , Rhodes Lesley E. , Sharif Jennifer C. H. , Kreeshan Firas C. , Farrar Mark D. , Ahad Tashmeeta 
Published: June 2020

AbstractBackgroundSystemic drugs are a potentially reversible cause of photosensitivity. We explore prevalence, impact, phototest findings and culprit drugs.MethodsRetrospective review of patients was diagnosed with drug‐induced photosensitivity in a specialist photoinvestigation centre (2000‐2016), using data recorded in standardized pro forma. Patients underwent detailed clinical evaluation. Monochromator phototesting was performed to 300 ± 5 nm, 320 ± 10 nm, 330 ± 10 nm, 350 ± 20 nm, 370 ± 20 nm, 400 ± 20 nm, 500 ± 20nm and 600 ± 20 nm. Broadband UVA and solar‐simulated radiation (SSR) testing were performed, and photopatch testing and laboratory tests examined for other causes of photosensitivity. DLQI was evaluated.ResultsPrevalence of drug‐induced photosensitivity was 5.4% (122/2243) patients presenting with photosensitivity. Patients with drug‐induced photosensitivity were 52.5% female; median 62 years (range 11‐86); phototype I (17.2%), II (39.3%), III (26.2%), IV (6.5%), V (4.1%). Fifty‐five (45.1%) patients had reduced erythemal thresholds on monochromator phototesting: 83.6%% to UVA alone, 14.5% to both UVA and UVB, 1.8% to UVA and visible light; 61.4% (n = 75) showed abnormal response to broadband UVR. Drugs implicated: quinine (11.5%), diuretics (10.7%; thiazide 9.8%), antifungals (9.8%), proton‐pump‐inhibitors (9.8%), angiotensin‐converting enzyme inhibitors (7.4%), anti‐inflammatory drugs (6.6%), statins (5.7%), selective serotonin reuptake inhibitors (4.9%), calcium channel antagonists (3.3%), anti‐epileptics (3.3%), tricyclic antidepressants (3.3%), beta‐blockers (2.5%), antibiotics (2.5%), others (≤1.6% cases each). Emerging culprits included azathioprine (2.5%) and biologics (TNF‐α inhibitors, denosumab; 2.5%). Median DLQI was 11 (range 2‐27) for the past year.ConclusionClassically described photosensitizing drugs such as thiazides and quinine remain common offenders, while emerging culprits include biologics such as TNF‐a inhibitors and proton‐pump‐inhibitors. There is very large impact on life quality; identification facilitates measures including drug cessation and implementation of appropriate photoprotection.
Vascular morphology and expression of angiogenic factors in sheep ovaries and their relation with the lambing rate
Authors: Wang Xinrong , Yang Yanan , Li Mingna 
Published: June 2020

AbstractThe study aims to present the vascular anatomy of ovarian arterial system in sheep and to explore its relation with the angiogenic factors vascular endothelial growth factor (VEGF) and angiopoietin‐2 (Ang‐2), environmental factors and the lambing rate. Small‐tailed Han sheep, Hu sheep, Aohan finewool sheep and Tibetan sheep who are from different habitats in China and with different lambing rates were investigated. The vascular corrosion casting technique and scanning electron microscopy were used to understand arterial architecture, and real‐time quantitative PCR (qRT‐PCR) and Western blotting were used for assessing VEGF and Ang‐2 expression. Results showed that high‐prolificity breeds had significantly larger vessel diameters in ovaries than low‐prolificity ones. VEGF gene transcript and protein expression were related with the lambing rate, while Ang‐2 gene transcript was negatively related with the lambing rate. Results indicated that high‐prolificity breeds have more abundant arterial blood supply, which is associated with VEGF expression.
Age‐related differences in vastus lateralis fascicle behavior during fast accelerative leg‐extension movements
Authors: Van Roie Evelien , Van Driessche Stijn , Delecluse Christophe , Vanwanseele Benedicte 
Published: June 2020

AbstractLeg‐extensor rate of power development (RPD) decreases during aging. This study aimed to identify the underlying mechanism of the age‐related decline in RPD during a fast acceleration in terms of in vivo vastus lateralis (VL) fascicle shortening behavior. Thirty‐nine men aged between 25 and 69 years performed three maximal isokinetic leg‐extensor tests with a fixed initial acceleration of 45° knee extension in 150 ms until 340°/s knee angular velocity. RPD, VL activity, and ultrasound images were recorded to assess (relative) fascicle shortening and mean shortening velocity for the phases of electromechanical delay, pretension, and acceleration. Our findings show that fascicle shortening and mean shortening velocity during a fast action increase with aging (0.002 per year, P = .035 and 0.005 s−1 per year, P = .097, respectively), mainly due to a higher amount of shortening in the phase of electromechanical delay. The ratio of VL fascicle length over upper leg length at rest showed a negative correlation (r = −.46, P = .004) with RPD/body mass, while pennation angle at rest showed a trend toward a positive correlation (r = .28, P = .089). To conclude, our findings indicate that the ability to reach high VL fascicle shortening velocities in vivo is not reduced in older men while performing preprogrammed fast accelerations. The greater amount of fascicle shortening in old age is probably the result of age‐related differences in the tendinous properties of the muscle‐tendon complex, forcing the fascicles to shorten more in order to transmit the muscle force to the segment.
Non‐toxigenic Vibrio cholerae in an autologous stem cell and renal transplant recipient
Authors: Xu Teena H. , Forrest Graeme N 
Published: June 2020

AbstractA patient with a renal transplant after an autologous stem cell transplant for multiple myeloma developed non‐toxigenic Vibrio cholerae diarrhea after travel to Mexico. This is a rare cause of diarrhea in transplant recipients, and the patient had not had pre‐travel counseling. This case reflects the lack of referral of transplant recipients for travel infectious disease review before overseas travel and the role of the live attenuated cholera vaccine.
Tomato SlIDA has a critical role in tomato fertilization by modifying reactive oxygen species homeostasis
Authors: Wang Rong , Shi ChunLin , Wang Xiaoyang , Li Ruizhen , Meng Yan , Cheng Lina , Qi Mingfang , Xu Tao , Li Tianlai 
Published: June 2020

SummaryAnther development and pollen tube elongation are key steps for pollination and fertilization. The timing and spatial distribution of reactive oxygen species (ROS) and programmed cell death are central to these processes, but the regulatory mechanism of ROS production is not well understood. Inflorescence deficient in abscission (IDA) is implicated in many plant development and responses to environmental stimuli. However, their role in reproductive development is still unknown. We generated tomato knockout lines (CR‐slida) of an IDA homolog (SlIDA), which is expressed in the tapetum, septum and pollen tube, and observed a severe defect in male gametes. Further analysis indicated that there was a programmed cell death defect in the tapetum and septum and a failure of anther dehiscence in the CR‐slida lines, likely related to insufficient ROS signal. Liquid chromatography‐tandem mass spectrometry identified mature SlIDA as a 14‐mer EPIP peptide, which was shown to be secreted, and a complementation experiment showed that application of a synthetic 14‐mer EPIP peptide rescued the CR‐slida defect and enhanced the ROS signal. Moreover, the application of the ROS scavengers diphenyleneiodonium or Mn‐TMPP suppressed peptide function. Collectively, our results revealed that SlIDA plays an essential role in pollen development and pollen tube elongation by modulating ROS homeostasis.
Real-Time Dynamics Modeling of Cryogenic Ball Bearings With Thermal Coupling
Authors: Gupta Pradeep K. , Gibson Howard G. 
Published: June 2020

Abstract
Real-time dynamic modeling of cryogenic ball bearings, where the rotating inner race accelerates to the operating speed, is based on integration of classical differential equations of motion of bearing elements, when experimentally measured ball/race traction behavior is used to compute the imposed acceleration on the rolling elements. The dynamic performance simulation provides a realistic coupling between traction behavior in the ball-to-race contacts and dynamics of bearing element motion as the bearing goes through the transient speed variation. However, due to vastly different mechanical and thermal time scales, heat generation in the bearing is time-averaged over a relatively large thermal time-step to model temperature fields as a step change, while the bearing motion is simulated in real-time. The emphasis is on dynamic modeling with thermal coupling in a static sense. Under stable conditions, the step change in temperature field converges to operating value as the bearing approaches a dynamic steady-state condition, which demonstrates acceptable significance of the dynamic simulation with coupled thermal interactions. Both all steel and hybrid ball bearings for liquid oxygen (LOX) turbo pump applications are modeled. Bearing performance simulations are closely modeled over experimental time cycles in both transient and steady-state domains. Steady-state solutions are shown to be independent of initial conditions to demonstrate acceptable convergence of time domain integrations. Model predictions of heat transferred to circulating LOX is within the range of variation in experimental data. Parametric evaluation of bearing performance as a function of operating conditions demonstrate that while the ball/race contact stress is higher in a hybrid bearing, contact heat generation is significantly lower in comparison with that in the all steel bearings.
An Assessment of Quantitative Predictions of Deterministic Mixed Lubrication Solvers
Authors: Wang Yuechang , Dorgham Abdel , Liu Ying , Wang Chun , Wilson Mark C. T. , Neville Anne , Azam Abdullah 
Published: June 2020

Abstract
The ability to simulate mixed lubrication problems has greatly improved, especially in concentrated lubricated contacts. A mixed lubrication simulation method was developed by utilizing the semi-system approach which has been proven to be highly useful for improving stability and robustness of mixed lubrication simulations. Then different variants of the model were developed by varying the discretization schemes used to treat the Couette flow terms in the Reynolds equation, varying the evaluation of density derivatives and varying the contribution of terms in the coefficient matrix. The resulting pressure distribution, film thickness distribution, lambda ratio, contact ratio, and the computation time were compared and found to be strongly influenced by the choice of solution scheme. This indicates that the output from mixed lubrication solvers can be readily used for qualitative and parametric studies, but care should be taken when making quantitative predictions.
Study on Prediction Model About Water Content in High-Temperature and High-Pressure Water-Soluble Gas Reservoirs
Authors: Huang Xiaoliang , Qi Zhilin , Li Sainan , Xiao Qianhua , Mo Fei , Fang Feifei 
Published: June 2020

Abstract
Because of a large amount of natural gas dissolved in the formation water of high-temperature and high-pressure (HTHP) water-soluble gas reservoirs, the water vapor content in water-soluble gas reservoirs is generally maintained under a supersaturated state; meanwhile, natural gas has a high carbon dioxide fraction, which significantly affects the water vapor content. Application of the conventional method to calculate the water content of HTHP water-soluble gas reservoirs leads to errors. In this work, the water content of HTHP water-soluble gas reservoirs was studied through laboratory experiments and theoretical research, and the main factors affecting water content were studied. Results show that the water content of water-soluble gas reservoirs decreases as pressure increases. The water content decreases faster in the low-pressure stage, while the decease of water content in the high-pressure stage is relatively steady. The water content of gas reservoirs increases with increasing temperature. When the temperature is lower than 100 °C, the change is slow; when the temperature is higher than 100 °C, the change is fast. The water content of gas reservoirs is affected by temperature during the low-pressure stage. The water content in the high-temperature stage is obviously affected by pressure; the water content of the gas reservoir is also affected by the carbon dioxide content of the natural gas component and the salinity of the formation water. Higher carbon dioxide content and lower formation water salinity yield higher water content. Furthermore, error analysis of the conventional water content prediction method and the measurement shows inconsistency in measurement and calculation. The error between the two methods is large, with an average of 54.88%. Based on the experiment, a mathematical model for calculating the water content of HTHP water-soluble gas reservoirs was established considering pressure, temperature, salinity, and natural gas composition. The predicted water vapor content of natural gas is close to the experimental value with a high precision. The average relative error between the measured and model calculated value is about 8.72%.
A Deep Insight Into the Transonic Flow of an Advanced Centrifugal Compressor Design
Authors: Wittrock David , Junker Martin , Beversdorff Manfred , Peters Andreas , Nicke Eberhard 
Published: June 2020

Abstract
In the last decades, major improvements in transonic centrifugal compressor design have been achieved. The further exploration of design space is enabled by recent progress in structural mechanics and manufacturing. A challenging task of inducer design especially in terms of transonic inflow conditions is to provide a wide flow range and reduced losses due to a sufficient shock control. The use of so-called multidisciplinary design optimization with an extensive amount of free parameters leads finally to complex designs. DLR’s latest fast rotating centrifugal compressor (SRV5) operates at a design speed of Mu2 = 1.72 and a total pressure ratio of 5.72. This compressor design is characterized by an S-shaped leading edge and free-form blade surfaces. Due to the complex design, the key design features are difficult to explore. Therefore, nonintrusive measurements are conducted on the highly loaded SRV5. The laser-2-focus (L2F) approach that is used in addition with the doppler-global-velocimetry (DGV) delivers a three-dimensional velocity field. Besides the impeller inflow, the outflow is also part of the experimental and numerical verification of the advanced compressor design. Experimental results are compared with the numerical analysis of the compressor using DLR’s Reynolds-averaged Navier–Stokes Flow Solver TRACE. The deep insight of the inflow leads to a better understanding of the operating behavior of such impeller designs.
Modeling Axisymmetric Centrifugal Compressor Characteristics From First Principles
Authors: Powers Katherine H. , Brace Chris J. , Budd Chris J. , Copeland Colin D. , Milewski Paul A. 
Published: June 2020

Abstract
Turbochargers are a vital component for aiding engine manufacturers in meeting the latest emissions standards. However, their range of operation is limited for low mass flows by compressor surge. Operation in surge results in pressure and mass flow oscillations that are often damaging to the compressor and its installation. Since surge is a highly complex flow regime, full unsteady three-dimensional models are generally too computationally expensive to run. The majority of current low-dimensional surge models use a cubic compressor characteristic that needs to be fitted to experimental data. Therefore, each time a compressor is studied using these models, costly experimental testing is required. In this paper, a new technique for obtaining an axisymmetric centrifugal compressor characteristic is presented. This characteristic is built using the equations of mass, momentum, and energy from first principles in order to provide a more complete model than those currently obtained via experimental data. This approach enables us to explain the resulting cubic-like shape of the characteristic and hence to identify impeller inlet stall as a route into surge. The characteristic is used within a quasi-steady, map-based surge model in order to demonstrate its ability to predict the onset of surge while only providing geometric data as input. Validation is provided for this model by a discussion of the qualitative flow dynamics and a good fit to experimental data, especially for low impeller speeds and pressure ratios.
Effect of Blade Row Interaction on Rotor Film Cooling
Authors: Brind J. , Pullan G. 
Published: June 2020

Abstract
The mechanisms of blade row interaction affecting rotor film cooling are identified to make recommendations for the design of film cooling in the real, unsteady turbine environment. Present design practice makes the simplifying assumption of steady boundary conditions despite intrinsic unsteadiness due to blade row interaction; we argue that if film cooling responds nonlinearly to unsteadiness, the time-averaged performance will then be in error. Nonlinear behavior is confirmed using experimental measurements of flat-plate cylindrical film cooling holes, mainstream unsteadiness causing a reduction in film effectiveness of up to 31% at constant time-averaged boundary condition. Unsteady computations are used to identify the blade row interaction mechanisms in a high-pressure turbine rotor: a “negative jet” associated with the upstream vane wake, and frozen and propagating vane potential field interactions. A quasi-steady model is used to predict unsteady excursions in momentum flux ratio of rotor cooling holes, with fluctuations of at least ±30% observed for all hole locations. Computations with modified upstream vanes are used to vary the relative strength of wake and potential field interactions. In general, both mechanisms contribute to rotor film cooling unsteadiness. It is recommended that the designer should choose a cooling configuration that behaves linearly over the expected unsteady excursions in momentum flux ratio as predicted by a quasi-steady hole model.
Theoretical Study of Energy Saving Through Redesign of Water Distribution Arrangement in a Medium-Rise Residential Building
Authors: Dandotiya Devendra , Banker Nitin D. 
Published: June 2020

Abstract
The development of medium-rise buildings for the residence is the basic necessity to accommodate the growing population of countries like India where the residential land per capita is very small. Moreover, because of the energy shortage, energy-efficient development is the primary objective in the present scenario. With the efforts of reducing energy consumption in the medium-rise buildings, redesign of the water distribution system has been proposed in this study. In this proposed arrangement, two water pumps are placed at two different elevations, namely, ground and middle levels of the building. The first one at the ground level supplies water first to the middle floor flats and the second one at the intermediate level does for the middle to the top floor flats. Various building heights and pumps are studied theoretically and the analysis of the results shows that about 20% of the total pump energy can be saved by changing the way of water distribution in the residential buildings. Yet further energy-saving potential is available through the selection of better efficiency pumps. Moreover, reduction in pressure of the water at the lower floor flats is an additional advantage of the proposed arrangement.