bluuebunny/crossref_metadata_2025 huggingface dataset:
Defect regulation of AlN films based on Al-rich AlN targets
Authors: Wen DanDan , Shen Yue , Sun PeiYang , Huang Jian , Gu Feng , Wang Linjun
Published: August 2022

Aluminum nitride (AlN) films with low defect concentration were fabricated on Si substrates via RF magnetron sputtering system based on Al-rich AlN (Al-AlN) targets. The effects of Al-rich content on structure, defects and photoelectric properties of AlN films were investigated by x-ray diffraction (XRD), high resolution transmission electron microscopy, x-ray photoelectron spectroscopy (XPS), low temperature photoluminescence (PL), ultraviolet-visible spectra, current–voltage (I–V) and capacitance–voltage (C–V) characteristics. In particular, the defects of AlN films were investigated by XPS and low-temperature PL analyses, indicating that Al-rich AlN targets can help to reduce the defects of Al vacancy and O impurity of AlN films with an optimal Al-rich content of 1.5 wt. % (A1.5). Schottky contact behavior between AlN films and Ti/Al/Ni/Au multi-layer electrodes were revealed from I–V curves of all samples based on parallel electrodes, and AlN metal-semiconductor-metal (MSM) devices prepared by A1.5 films exhibited the lowest leakage current of 2.43 × 10−8 A at the bias of 5 V. C–V tests indicate the less defect density and lower carrier concentrations of vertical structure of A1.5 devices. This work offers a feasible approach to regulate the defects of AlN films for practical application.
Numerical studies on saturated kink and sawtooth induced fast ion transport in JET ITER-like plasmas
Authors: Bonofiglo P.J. , Podestà M. , Vallar M. , Gorelenkov N.N. , Kiptily V. , White R.B. , Giroud C. , Brezinsek S. , Contributors JET
Published: August 2022

This presentation examines the energetic particle transport induced by saturated kink modes and sawtooth crashes in JET deuterium plasmas. It is known that kink mode-resonant transport and phase-space redistribution from sawtooth crashes can drive strong fast ion transport with dependencies on particle pitch and energy. Measurements with JET’s Faraday cup fast ion loss detector array have shown that the internal kink growth phase preceding sawtooth crashes produces substantial fast ion losses. This report will numerically investigate the dominant energetic particle transport mechanism with a detailed examination of the fast ion phase-space dependencies, resonances, orbit topology changes, induced losses, and redistribution associated with the long-lived, resonant, kink mode and non-resonant sawtooth crash. The ORBIT-kick model forms the basis of the transport studies with realistic fast ion distributions produced from TRANSP. A recently created reduced model for sawtooth induced transport is used while the saturated kink modes are modeled with ideal magnetohydrodynamic codes. The simulations were further validated against experiment with a newly developed synthetic Faraday cup fast ion loss detector in addition to scintillator probe and neutron measurements.
Thick interface size effect on dislocation transmission in nanolaminates
Authors: Xu S , Cheng J Y , Mara N A , Beyerlein I J
Published: August 2022

Recent experimental studies have reported that thick interfaces in nanolaminates can lead to greater strengths than conventionally sharp interfaces without sacrificing deformability. Using a multi-phase phase-field dislocation dynamics model, dislocation transmission across a compositionally graded, nanoscale thick interface is investigated. Thicker interfaces over a finite range are found to lead to greater resistance to transmission. The limit interface thickness at which the peak resistance is reached, and the strengthening capacity of the interface are greater when the dislocation is dissociated, as in a face-centered cubic lattice, than when it is compact, as in a body-centered cubic lattice. The composition transitions within the interface are treated with multiple sublayers, and it is found that the interface transmission barrier is as strong as its most resistance composition.
Local deformation mechanisms in metal systems with a tailored grain size distribution
Authors: Godfrey A , Gao W Q , Le G M , Zhang C L , Zhu K N
Published: August 2022

A large change in yield strength and ductility takes place in metals with a recrystallized average grain size in the near-micrometer grain size regime. This has been utilized to explore the influence of grain size heterogeneity on plastic deformation for recrystallized grains in aluminum prepared by spark plasma sintering, where tailoring of the grain size distribution and spatial arrangement can be achieved by selecting powder sizes and mixing conditions prior to sintering. The spatial variation of plastic deformation has been explored by digital image correlation (DIC), either at the sample scale or at the grain scale. For the latter colloidal SiO2 markers also allow repeated collection of electron backscatter diffraction data over the same area during in-situ deformation, proving correlated information on local displacement gradients and crystal lattice rotations. For samples prepared from well-mixed powders only small deviations from a rule-of-mixtures in the yield strength are observed. A mesoscale pattern of strain distribution is observed from DIC investigations where this is related to, but not fully consistent with, the spatial arrangement of fine and coarse grains. In the case of macroscopically layered arrangements of coarse and fine grains, deformation is dominated by development of local strain concentrations, which take place preferentially in the fine grain regions.
Crystallographic Variability in Additive Manufacturing
Authors: Fonda Richard W. , Rowenhorst David J.
Published: August 2022

The crystallographic textures produced during additive manufacturing can be understood, predicted, and manipulated by varying the grain nucleation and growth processes. The resultant textures are primarily dictated by the melt pool geometry, which defines the local thermal gradient and thus the preferred crystal growth directions, as well as the scan strategy, which controls the propagation of grain orientations into subsequent layers. This texture can be diluted through heterogeneous nucleation of new grain orientations, which can occur through a variety of mechanisms. This ability to control the texture during additive manufacturing can enable the location-specific control of properties as a function of position in the build.
Grain growth in thin film under strong temperature gradients
Authors: Zöllner Dana , Pantleon Wolfgang
Published: August 2022

Grain growth in thin films has attracted lots of attention due to the numerous applications of polycrystalline films, on one hand, and modified properties due to changes in the microstructure caused by thermal effects, on the other hand. While the phenomenon of grain growth is well understood in general, effects of e.g. temperature gradients leave questions open still today. In the present study, we investigate the influence of strong temperature gradients on grain growth in thin films. To that aim, a modified three-dimensional Potts model algorithm is employed, where the annealing temperature depends on the position within the sample leading to spatial heterogeneities in the grain boundary network. As a consequence of different mobilities, a drag effect occurs on the boundary network evolution that has serious consequences for the microstructures evolving during grain growth.
Grain boundary evolution in nanograined metals: from relaxation to Schwarzation
Authors: Li X , Lu K
Published: August 2022

High density of grain boundaries (GBs) in nanograined metals may become unstable and evolve in various ways such as migration, sliding, or relaxation under thermal or mechanical stimuli. In this report, we will present our recent studies on structural evolution of GBs in nanograined Cu during intensive plastic deformation. As the grain size decreased below 200 nm, GB migration become obvious assisted by dislocation activities. Below 70 nm, accompanied by a transition in dominant deformation mechanism from full dislocations to partials, GB migration decays gradually, while the GB structures relax into lower energy states through their interactions with partials. The population of low-energy GBs increases with a decreasing grain size. Below 10 nm, further refinement of grains results in a violent structural evolution of the GB network into a 3-dimensional periodic minimal surface structure, Schwarz-D, through a phase-transformation-like process, which is termed as Schwarzation.
Characterization of hierarchical lath martensite microstructure in low carbon steels using ultra-high voltage TEM and SEM-EBSD analysis
Authors: Sugiyama M , Takei M , Sekida S , Maruyama N
Published: August 2022

Lath martensite is a heterogenous microstructure in low carbon steels and plays an important part in microstructure for the high strength steels. The complex martensitic structure has been clarified as the hierarchical block and packet structures using SEM observations and electron backscatter diffraction (EBSD) analysis. As the result of variant analysis, it is found that the block consists of sub-blocks and the block size and distribution seem to be new key factors to control the mechanical properties. Each block is further subdivided by laths, which are the finest structural units in lath martensite. The morphology of laths and their variants in low carbon steels has been further investigated using the ultra-high voltage TEM (UHVEM) with 3MeV in accelerated voltage. Based on a comparison of UHVEM and SEM observations for the same field of view, it is found that the laths have a further hierarchical organization with twinned morphology and the fragmented structure within the laths. Two plane crystal analysis of the twin in a lath has been carried out using SEM-EBSD analysis after Xe-FIB large area fabrication process, resulting in the identification of the twin morphology such as the {112} twin plane perpendicular to the {110} habit plane and along the <111> direction. Although several types of twinned morphology such as the long and short length are observed in the lath microstructure under TEM observations, the twinning structure observed in various forms is explained by a simple model in the present study.
Laboratory-scale gas atomizer for the manufacturing of metallic powders
Authors: del Rio D C , Juul Jensen D , Yu T , Tiedje N S
Published: August 2022

Metallic powders for additive manufacturing (AM) processes are primarily produced by gas atomization, which consists of three steps: melting, atomization and cooling. In the present work, we report on the refurbishing of a laboratory-scale gas atomizer. The equipment facilitates small-scale atomization, useful for developing powders tailored specifically to metal AM processes (e.g. binder jetting, laser powder-bed fusion and direct energy deposition). The refurbished atomizer is operated by an in-house measurement and control system, fully equipped with pressure, oxygen, gas-flow and temperature sensors that allow the user to experiment with the input parameters, and thus, understand how they affect the physical and chemical properties of powders. In this paper, the working principle of the laboratory-scale gas atomizer is presented and the main characteristics of the newly refurbished equipment are described.
In-situ X-ray microtomography of interface between additively manufactured aluminium bronze and H13 tool steel
Authors: Linga Håkon , Zhang Yubin , Brøtan Vegard , Ren Xiaobo , Westermann Ida , Holmedal Bjørn
Published: August 2022

Directed energy deposition (DED) is an additive manufacturing process category where material is melted as it is deposited, often powder melted with a focused laser. In this work aluminium bronze was deposited onto H13 tool steel using this technique, forming a mixing zone between the two metals. This mixing zone was examined with X-ray microtomography to obtain a three dimensional perspective that is unrealizable with conventional microscopy. Both the shape of the melt pools, the microstructure within, and processing defects could be discerned due to varying absorption of the radiation. In addition to characterizing the microstructure, the sample was also strained in three steps; the first step was to approximately 2.5 % strain, the second to 10.5 % and finally until fracture of the sample. The sample was scanned between each step, including a scan of the fracture surface. The ultimate tensile strength was found to be approximately 850 MPa and the fracture was observed to originate from cracks between the H13 substrate and the mixing zone. These cracks appeared to form in the second step of the straining. Additionally, local strains were estimated by utilizing pores in the sample as tracking points.
Registration of data from a multimodal investigation of particle stimulated nucleation in aluminum
Authors: Knipschildt E F F , Lei X , Zhang Y B , Yu T , Fæster S , Liu W , Sanders R E , Juul Jensen D
Published: August 2022

Nucleation of recrystallization at large second phase particles during annealing is essential in many industrially relevant aluminum alloys. To adequately quantify the spatial distribution of such particles and their impact on nucleation in bulk materials, 3D investigations are needed. This study presents a multimodal characterization method to investigate particle stimulated nucleation in a heavily deformed AA5182 alloy. To map the spatial distribution of large second phase particles, conventional laboratory absorption contrast X-ray tomography is used, while the recrystallization nuclei are revealed by Laue micro-diffraction using synchrotron X-rays. The registration of data obtained by the two different non-destructive high-resolution experimental techniques is described. Finally, some preliminary results are presented.
Corrosion Performance of Additively Manufactured Stainless Steel by Binder Jetting
Authors: Kaae P H , Eikeland E Z
Published: August 2022

The influence of microstructural defects on the corrosion resistance of AISI 316L additively manufactured with Metal Binder Jetting in high Cl- environments were studied herein. A comprehensive metallographic examination was conducted to identify microstructural defects followed by a corrosion study with electrochemical techniques with the aim of finding correlations between impurities in the microstructure and preferential nucleation sites. Despite, the high number of inclusions in the microstructure of the studied samples, none of the conducted corrosion tests showed a clear indication that they resulted in a decreased corrosion resistance as compared to areas with few inclusions. However, a significant higher pitting potential was observed on the as-printed samples compared to samples grinded with 600 grit SiC paper which will be discussed further.
Scaffold microarchitecture regulates angiogenesis and the regeneration of large bone defects
Authors: Eichholz Kian F , Freeman Fiona E , Pitacco Pierluca , Nulty Jessica , Ahern Daniel , Burdis Ross , Browe David C , Garcia Orquidea , Hoey David A , Kelly Daniel J
Published: August 2022

Emerging 3D printing technologies can provide exquisite control over the external shape and internal architecture of scaffolds and tissue engineering (TE) constructs, enabling systematic studies to explore how geometric design features influence the regenerative process. Here we used fused deposition modelling (FDM) and melt electrowriting (MEW) to investigate how scaffold microarchitecture influences the healing of large bone defects. FDM was used to fabricate scaffolds with relatively large fibre diameters and low porosities, while MEW was used to fabricate scaffolds with smaller fibre diameters and higher porosities, with both scaffolds being designed to have comparable surface areas. Scaffold microarchitecture significantly influenced the healing response following implantation into critically sized femoral defects in rats, with the FDM scaffolds supporting the formation of larger bone spicules through its pores, while the MEW scaffolds supported the formation of a more round bone front during healing. After 12 weeks in vivo, both MEW and FDM scaffolds supported significantly higher levels of defect vascularisation compared to empty controls, while the MEW scaffolds supported higher levels of new bone formation. Somewhat surprisingly, this superior healing in the MEW group did not correlate with higher levels of angiogenesis, with the FDM scaffold supporting greater total vessel formation and the formation of larger vessels, while the MEW scaffold promoted the formation of a dense microvasculature with minimal evidence of larger vessels infiltrating the defect region. To conclude, the small fibre diameter, high porosity and high specific surface area of the MEW scaffold proved beneficial for osteogenesis and bone regeneration, demonstrating that changes in scaffold architecture enabled by this additive manufacturing technique can dramatically modulate angiogenesis and tissue regeneration without the need for complex exogenous growth factors. These results provide a valuable insight into the importance of 3D printed scaffold architecture when developing new bone TE strategies.
Effects of magnesium on microstructure, properties and degradation behaviors of zinc-based alloys prepared by selective laser melting
Authors: Ning Jie , Ma Zheng-Xiong , Zhang Lin-Jie , Wang Di-Pin , Na Suck-Joo
Published: August 2022

Selective laser melting (SLM) technology was employed to manufacture Zn-3%Mg alloy and the effects of the addition of Mg elements on the density, microstructure, mechanical property and corrosion behavior of Zn-based alloy additively manufactured parts was investigated. Experiment results demonstrate that the density of pure Zn-based additively manufactured parts under optimal parameters can be up to 96.7%. With the same parameters, Zn–3Mg alloy was prepared by SLM additive manufacturing technology to obtain additively manufactured parts of Zn–3Mg alloy with the density of 96.0%. Compared with pure Zn, the average grain size in horizontal sections of additively manufactured parts added with 3 wt% Mg reduces from about 21.1 μm to about 2.1 μm and columnar crystals in vertical sections are transformed into equiaxed crystals. The microhardness of Zn–3Mg alloy is 2.6 times higher than that of pure Zn and tensile strengths in both the horizontal and vertical directions of Zn–3Mg alloy are twice as high as that of pure Zn. Moreover, the yield strength of Zn–3Mg alloy under compressive load is more than three times higher than that of pure Zn. After immersing pure Zn and Zn–3Mg alloy in simulated body field (SBF) for 7 days, their corrosion rates tend to be stable, i.e. about 0.13 and 0.09 mm·year−1 respectively, that is, the corrosion rate of Zn–3Mg alloy is about 70% that of pure Zn.
Impact of ammonia treatment and platinum group or nickel metal decoration on the activated carbon storage of carbon dioxide and methane
Authors: Aboud Mohamed F Aly , ALOthman Zeid A , Bagabas Abdulaziz A
Published: August 2022

Greenhouse gases, chiefly carbon dioxide (CO2) and methane (CH4), emission is responsible for the global warming and heat waves which strike the world causing floods and droughts everywhere with more CO2attributions. The adsorption and desorption capacities of CO2and CH4at room temperature and up to 5.0 and 100 bar, respectively, were investigated for the untreated and ammonia-treated activated carbons (ACs), metal-anchored (metal: Ru, Rh, Pd, Ir or Ni) samples. We merged ammonia treatment and metal decoration to discover their influences on the CO2and CH4storage capability of ACs and the potential use of such modified ACs for capturing greenhouse gases and purifying natural gas from CO2. The CO2storage capacities ranged between 25.2 and 27.7 wt% at 5.0 bar with complete regeneration upon desorption, while the uptakes for CH4were in the range of 9.6 − 12.6 wt% at 35 bar with hysteresis behavior of the adsorbed gas. The highest adsorption capacities were achieved for the pristine samples, showing that metal decoration reduced slightly the adsorption. Ammonia-treated samples showed minor enhancing effect on the CH4adsorption in comparison to the CO2adsorption. The higher adsorption capacities of CO2than those of CH4could be employed for upgrading the natural gas, while the 9.6 wt% (2.2 mmol g−1) CO2storage capacity would allow for its removal from the flue gases at ambient temperature and pressure. The higher adsorption capacity and preferentiality of CO2over CH4could be attributed mainly to its higher quadrupole moment and its higher clustering above the AC surfaces, while a minor effect, if any, would be attributed to the modifications of the ACs, implying that physisorption mechanism acted significantly in the adsorption process in comparison to chemisorption mechanism at the studied conditions.
Effect of processing parameters on the properties of electrolytically prepared Mg(OH)2 powders
Authors: Guo Lili , Li Zhen , Deng Xinzhong , Chen Na , Yang Li , Su Yang , Wang Xiaomin
Published: August 2022

In this paper, Mg(OH)2 was prepared by the diaphragm electrolysis method using bischofite (MgCl2·6H2O). The influence of electrolysis process conditions such as current density, electrolysis temperature and electrolyte concentration on powder particle size is discussed. The electrolytic product Mg(OH)2 powder was characterized by laser particle size analysis, XRD, SEM, BET, XRF, and DSC-TGA. The results show that the particle size of Mg(OH)2 powder first increases and then decreases with increasing current density and reaches a maximum D50 value of 20.1 μm at a current density of 0.04 A cm−2. The Mg(OH)2 powder particle size first decreases, then increases and then decreases with increasing electrolysis temperature, at an electrolysis temperature of 60 °C and 70 °C, the particle size reaches a maximum D50 value of 23.8 μm and a minimum D50 value of 7.7 μm, respectively. The Mg(OH)2 powder particle size first increases and then decreases with increasing electrolyte concentration and reaches a maximum D50 value of 22.3 μm at an electrolyte concentration of 0.7 mol l−1. The Mg(OH)2 powder prepared at a current density of 0.3 A cm−2, electrolyte concentration of 0.3 mol l−1 and an electrolysis temperature of 30 °C shows an average particle size of 13.8 μm, a purity higher than 98.66%, and a sheet-like structure. The surface area is 58 m2 g−1. The Mg(OH)2 powder can be decomposed at 300 °C–400 °C and calcined at 400 °C for 2 h, through SEM and Scherrer formula calculation, the calcined product is nano-MgO powder with good crystallinity.
Ricci flow and diffeomorphism groups of 3-manifolds
Authors: Bamler Richard , Kleiner Bruce
Published: August 2022

We complete the proof of the Generalized Smale Conjecture, apart from the case of

R

P
3

RP^3

, and give a new proof of Gabai’s theorem for hyperbolic

3
3

-manifolds. We use an approach based on Ricci flow through singularities, which applies uniformly to spherical space forms, except

S
3

S^3

and

R

P
3

RP^3

, as well as hyperbolic manifolds, to prove that the space of metrics of constant sectional curvature is contractible. As a corollary, for such a

3
3

-manifold

X
X

, the inclusion

Isom
⁡
(
X
,
g
)
→
Diff
⁡
(
X
)

\operatorname {Isom}(X,g)\rightarrow \operatorname {Diff}(X)

is a homotopy equivalence for any Riemannian metric

g
g

of constant sectional curvature.
The ultrastructural organization of endoplasmic reticulum-plasma membrane contacts is conserved in epithelial cells
Authors: Chung Gary Hong Chun , Lorvellec Maëlle , Gissen Paul , Pichaud Franck , Burden Jemima J. , Stefan Christopher J.
Published: August 2022

Quantitative electron microscopy of hepatocytes and epithelial spheroids reveals an extensive network of intracellular contacts between the endoplasmic reticulum and plasma membrane (ER-PM contacts) at lateral PM domains that form intercellular junctions, indicative of conserved roles of ER-PM contacts in epithelial cell and tissue architecture.
The Effect of SBIRT on Harmful Alcohol Consumption in the Community Health Centers of Shanghai, China: A Randomized Controlled Study
Authors: Zhai Jing , Wang Wenzheng , Zhang Lei , Fu Rao , Zeng Qingzhi , Huang Leping , Zhao Min , Du Jiang
Published: August 2022

Objective

The present study was a randomized controlled trial with a longitudinal design aimed at examining the effectiveness of Screening, Brief Intervention and Referral to Treatment (SBIRT) on harmful alcohol use in the community health centres in Shanghai, China, and further compared the effects of a multi-session brief intervention (MBI) and a single-session brief intervention (SBI).

Methods

A total of 362 participants were recruited from four districts of Shanghai and randomly assigned to MBI, SBI and routine care (RC) groups. The MBI group received the brief intervention twice. Follow-up assessments were conducted at 1 and 3 months after the intervention.

Results

Compared with the SBI and the RC groups, the Alcohol, Smoking and Substance Involvement Screening Test (ASSIST) scores (F = 6.422, P = 0.002), SDS scores (F = 5.779, P = 0.003) and SAS scores (F = 4.004, P = 0.019) were significant improved in the MBI group at 1and 3-month follow-up assessment. In the SBI group, the SDS scores decreased significantly compared with the RC group, and there were no significant differences in ASSIST scores, drinking knowledge scores and SAS scores 1-month follow-up assessment.

Conclusion

The findings suggested that SBIRT with two sessions of BI had considerable effects on individuals with harmful alcohol use. It provided clinical evidence for future use in China and other Asian countries with similar situations.
Linkages between traits and decomposition of weed communities along a soil management and pedoclimate gradient in Mediterranean vineyards
Authors: Bopp Marie-Charlotte , Fried Guillaume , Metay Aurélie , Bastianelli Denis , Bonnal Laurent , Kazakou Elena
Published: August 2022

Background and Aims

Decomposition is a major ecosystem process which improves soil quality. Despite that, only a few studies have analysed decomposition in an agricultural context, while most agrosystems (e.g. vineyards) are facing decreasing soil quality. The objective of this study is to understand the impacts of both pedoclimate and weed management on the mass loss of vineyard weed communities during the early stages of the decomposition process through their functional properties.

Methods

In 16 Mediterranean vineyards representing both a pedoclimate and a soil management gradient, we measured the mass loss of green above-ground biomass of 50 weed communities during decomposition in standard conditions and key leaf traits of dominant species [e.g. leaf dry matter content (LDMC) and leaf lignin to nitrogen ratio (lignin:N)]. Both the mean [i.e. community-weighted mean (CWM)] and diversity (i.e. Rao index) were computed at the community level. Path analysis was used to quantify the effects of agro-environmental filters on the mass loss of weed communities through their functional properties.

Key Results

Tillage and mowing filtered more decomposable communities than chemical weeding (16 and 8 % of higher mass loss after 2 months of decomposition). Path analysis selected weed management practice type as the main factor determining mass loss through its effect on functional properties, while soil and climate had minor and no effects, respectively. Chemical weeding favoured communities with higher investment in resistant leaves (e.g. 38 % higher lignin:N, 22 % lower leaf nitrogen content) which resulted in lower mass loss compared with tilled and mowed communities. Mowing favoured communities with 47 % higher biomass and with 46 % higher nitrogen content.

Conclusions

Weed management significantly influenced weed mass loss, while the pedoclimate had little effect. Our results suggest that mowing is a promising alternative to herbicide use, favouring higher biomass, nitrogen content and decomposability potential of weeds.
Cost–benefit analysis of mesophyll conductance: diversities of anatomical, biochemical and environmental determinants
Authors: Mizokami Yusuke , Oguchi Riichi , Sugiura Daisuke , Yamori Wataru , Noguchi Ko , Terashima Ichiro
Published: August 2022

Background

Plants invest photosynthates in construction and maintenance of their structures and functions. Such investments are considered costs. These costs are recovered by the CO2 assimilation rate (A) in the leaves, and thus A is regarded as the immediate, short-term benefit. In photosynthesizing leaves, CO2 diffusion from the air to the carboxylation site is hindered by several structural and biochemical barriers. CO2 diffusion from the intercellular air space to the chloroplast stroma is obstructed by the mesophyll resistance. The inverses is the mesophyll conductance (gm). Whether various plants realize an optimal gm, and how much investment is needed for a relevant gm, remain unsolved.

Scope

This review examines relationships among leaf construction costs (CC), leaf maintenance costs (MC) and gm in various plants under diverse growth conditions. Through a literature survey, we demonstrate a strong linear relationship between leaf mass per area (LMA) and leaf CC. The overall correlation of CC vs. gm across plant phylogenetic groups is weak, but significant trends are evident within specific groups and/or environments. Investment in CC is necessary for an increase in LMA and mesophyll cell surface area (Smes). This allows the leaf to accommodate more chloroplasts, thus increasing A. However, increases in LMA and/or Smes often accompany other changes, such as cell wall thickening, which diminishes gm. Such factors that make the correlations of CC and gm elusive are identified.

Conclusions

For evaluation of the contribution of gm to recover CC, leaf life span is the key factor. The estimation of MC in relation to gm, especially in terms of costs required to regulate aquaporins, could be essential for efficient control of gm over the short term. Over the long term, costs are mainly reflected in CC, while benefits also include ultimate fitness attributes in terms of integrated carbon gain over the life of a leaf, plant survival and reproductive output.
Zona pellucida removal by acid Tyrode’s solution affects pre- and post-implantation development and gene expression in mouse embryos
Authors: Fan Weihong , Huang Tengda , Wu Tian , Bai Hanako , Kawahara Manabu , Takahashi Masashi
Published: August 2022

The zona pellucida plays a crucial role in the process of fertilization to early embryonic development, including cellular arrangement and communication between blastomeres. However, little is known regarding the role of the zona pellucida in pre- and post-implantation embryonic development associated with gene expression. We investigated the effect of zona pellucida removal on pre- and post-implantation development of mouse embryos. After zona pellucida removal of two-cell stage embryos was performed by acid Tyrode’s solution, which is commonly used for zona pellucida treatment, compaction occurred earlier in zona pellucida-free than zona pellucida-intact embryos. In addition, the expression of differentiation-related genes in the inner cell mass and trophectoderm was significantly altered in zona pellucida-free blastocyst compared with zona pellucida-intact embryos. After embryo transfer, the rate of implantation and live fetuses was lower in zona pellucida-free embryos than in control embryos, whereas the fetal weight at E17.5 was not different. However, placental weight significantly increased in zona pellucida-free embryos. RNA-sequencing analysis of the placenta showed that a total of 473 differentially expressed genes significantly influenced the biological process. The present study suggests that zona pellucida removal by acid Tyrode’s solution at the two-cell stage not only disturbs the expression pattern of inner cell mass-/trophectoderm-related genes but affects the post-implantation development of mouse embryos. Overall, this study provides deeper insight into the role of the zona pellucida during early embryonic development and the viability of post-implantation development.
Recognising or Minimising Ethical Trespass? An Exploration of Professionals’ Moral Agency in Prioritising Cases
Authors: Gevaert Koen , Keinemans Sabrina , Roose Rudi
Published: August 2022

Deciding about priority cases in waiting lists is a controversial activity. However, it is a well-known challenge for many social workers. This article addresses two questions related to this problem: how do social workers, as moral agents, experience the policy context in which they must prioritise cases, and what stance do they take towards it? Building on a previous study where a practice of case prioritisation was observed, semi-structured interviews were conducted (n = 11) to explore these questions. The data were analysed through an inductive process of deepening interpretation. The findings paint a picture of ambivalence: the professionals adhere to the policy guidelines of neutrality, priority for the worst-off and equal application of criteria, which are at the same time contradicted by their lived experience. The decision-making process appears to be much more contextual, particularistic and interpretative than the policy guidelines suggest. Questions are raised as to why this reality remains hidden after a discourse of simple rule-following.
Pioglitazone-incorporated microspheres targeting macrophage polarization alleviates cardiac dysfunction after myocardial infarction
Authors: Konegawa Yasushi , Kuwahara Toshie , Jo Jun-Ichiro , Murata Kozue , Takeda Takahide , Ikeda Tadashi , Minatoya Kenji , Masumoto Hidetoshi , Tabata Yasuhiko
Published: August 2022

OBJECTIVES

Excessive and chronic inflammation after a myocardial infarction (MI) is associated with left ventricular remodelling and impaired cardiac function. Among inflammatory cells, macrophages play a critical role in polarizing proinflammatory M1 or the reparative M2 subtype. Pioglitazone (PGZ) is reported to regulate macrophage polarization to the M2 subtype. Our goal was to validate the therapeutic effects and the mechanisms of PGZ utilizing a drug delivery system.

METHODS

Poly L-lactic-co-glycolic acid microspheres (MS) incorporating PGZ were prepared. To validate the therapeutic potential of PGZ-MS, Sprague-Dawley rats were subjected to permanent left coronary artery ligation to induce an MI. Placebo-MS (100 μg) or PGZ-MS (100 μg) was injected to the infarct region just after induction. Cardiac function and size were assessed by echocardiography. At 28 days after surgery, the rats were sacrificed, and the excised hearts were evaluated histologically.

RESULTS

Sustained release of PGZ from the PGZ-MS was confirmed in vitro. PGZ-MS significantly rehabilitated cardiac dysfunction after an MI (fractional shortening: MI vs MI+placebo-MS vs MI+PGZ-MS, 24.4 ± 1.1 vs 24.3 ± 1.6 vs 32.2 ± 1.4%; P = 0.0035) with reverse remodelling. Immunohistochemical analyses revealed that PGZ-MS enhanced macrophage polarization (ratio of M2 subtype: 0.39 ± 0.03 vs 0.42 ± 0.02 vs 0.54 ± 0.02; P = 0.0004) and attenuated apoptosis of cardiomyocytes in the ischaemic border zone.

CONCLUSIONS

We confirmed macrophage polarization by sustained release of PGZ, which resulted in amelioration of adverse left ventricular remodelling and cardiac dysfunction. Drug delivery system-based macrophage polarization might serve as a promising strategy in cardiac regenerative therapy for ischaemic heart disease. (241 words)
Comparative analysis of the fecal bacterial communities of hawksbill sea turtles (Eretmochelys imbricata) and green sea turtles (Chelonia mydas)
Authors: Chen Yuan , Xia Zhongrong , Li Hongwei
Published: August 2022

Hawksbill sea turtles (Eretmochelys imbricata) are important for maintaining healthy coral reef ecosystems currently qualify as “critically endangered” by the IUCN. Their gut microbiota is closely linked to host nutrition and health, however, the gut microbiota of hawksbill sea turtles from a natural reserve remains unclear. Therefore, exploring their microbial community structure in a natural reserve may provide valuable information on strategies for protecting this species. In this study, we investigated hawksbill sea turtle fecal microbial communities from a natural reserve using 16S metagenomics and compared the gut microbiota from fecal samples of hawksbill and green sea turtles (Chelonia mydas). The results indicated that the structure of fecal microbial communities was significantly different between hawksbill and green sea turtles. In hawksbill sea turtles, the three dominant phyla were Bacteroidetes, Firmicutes, and Fusobacteria, whereas the fecal microbial communities of green sea turtles were mainly composed of Firmicutes, Bacteroidetes, and Proteobacteria. Among the hawksbill sea turtle fecal microbes, the predominant genera were Cetobacterium and Rikenell, whereas in green sea turtles, the predominant genera were Bacteroides and Paludibacter. In addition, predictive metagenomic analysis indicated that sugar catabolism was enriched in green sea turtle fecal microbiota, whereas pathways related to secondary metabolite production were enriched in hawksbill sea turtle fecal microbiota. Our study provides preliminary data on the fecal microbiota features of sea turtles from the natural reserve, which may contribute to the management of the food requirements and long-term conservation of hawksbill sea turtles.
Abnormal morphology and function in retinal ganglion cells derived from patients-specific iPSCs generated from individuals with Leber’s hereditary optic neuropathy
Authors: Nie Zhipeng , Wang Chenghui , Chen Jiarong , Ji Yanchun , Zhang Hongxing , Zhao Fuxin , Zhou Xiangtian , Guan Min-Xin
Published: August 2022

Leber’s hereditary optic neuropathy (LHON) is a maternally inherited eye disease that results from degeneration of retinal ganglion cells (RGC). Mitochondrial ND4 11778G > A mutation, which affects structural components of complex I, is the most prevalent LHON-associated mitochondrial DNA (mtDNA) mutation worldwide. The m.11778G > A mutation is the primary contributor underlying the development of LHON and X-linked PRICKLE3 allele (c.157C > T, p.Arg53Trp) linked to biogenesis of ATPase interacts with m.11778G > A mutation to cause LHON. However, the lack of appropriate cell and animal models of LHON has been significant obstacles for deep elucidation of disease pathophysiology, specifically the tissue-specific effects. Using RGC-like cells differentiated from induced pluripotent stem cells (iPSCs) from members of one Chinese family (asymptomatic subjects carrying only m.11778G > A mutation or PRICKLE3 p.Arg53Trp mutation, symptomatic individuals bearing both m.11778G > A and PRICKLE3 p.Arg53Trp mutations and control lacking these mutations), we demonstrated the deleterious effects of mitochondrial dysfunctions on the morphology and functions of RGCs. Notably, iPSCs bearing only m.11778G > A or p.Arg53Trp mutation exhibited mild defects in differentiation to RGC-like cells. The RGC-like cells carrying only m.11778G > A or p.Arg53Trp mutation displayed mild defects in RGC morphology, including the area of soma and numbers of neurites, electrophysiological properties, ATP contents and apoptosis. Strikingly, those RGC-like cells derived from symptomatic individuals harboring both m.11778G > A and p.Arg53Trp mutations displayed greater defects in the development, morphology and functions than those in cells bearing single mutation. These findings provide new insights into pathophysiology of LHON arising from RGC deficiencies caused by synergy between m.11778G > A and PRICKLE3 p.Arg53Trp mutation.
Sustained air pollution exposures, fasting plasma glucose, glycated haemoglobin, prevalence and incidence of diabetes: a nationwide study in China
Authors: Liu Feifei , Zhang Ke , Chen Gongbo , He Jie , Pan Mengnan , Zhou Feng , Wang Xiangxiang , Tong Jiahui , Guo Yuming , Li Shanshan , Xiang Hao
Published: August 2022

Background

Evidence remains limited and inconsistent for the associations between sustained air pollution exposures and diabetes development. This study aimed to determine the potential effects of particulate matter with a diameter of ≤10 micrometres (PM10), particulate matter with a diameter of ≤2.5 micrometres (PM2.5) and nitrogen dioxide (NO2) on alterations of fasting plasma glucose (FPG), glycated haemoglobin (HbA1c), in particular, on prevalence and incidence of diabetes.

Methods

Cross-sectional analyses were conducted based on 9628 participants aged ≥45 years from the baseline survey (2011) of the China Health and Retirement Longitudinal Study (CHARLS), whereas cohort analyses were based on 3510 individuals without diabetes at baseline in the third survey (2015). Residences of participants were geocoded and the air pollution exposures were estimated using a satellite-based spatiotemporal model. Linear, logistic and modified Poisson regression models, adjusting for multiple confounders, were applied to assess the associations between air pollution and FPG, HbA1c, prevalence and incidence of diabetes, respectively.

Results

Associations between PM10, PM2.5 and increased levels of FPG and HbA1c were identified. The levels of FPG and HbA1c increased by 0.025 mmol/L (95% CI: 0.007, 0.044) and 0.011 mmol/L (95% CI: 0.002, 0.019), respectively, for a 10-μg/m3 increase in PM10, and the levels of FPG and HbA1c increased by 0.061 mmol/L (95% CI: 0.028, 0.096) and 0.016 mmol/L (95% CI: 0.000, 0.031), respectively, for a 10-μg/m3 increase in PM2.5. There were also positive associations between diabetes prevalence and PM2.5 and PM10. In the cohort analyses, PM10, PM2.5 and NO2 were associated with a higher incidence of diabetes.

Conclusion

Air pollution was allied to diabetes development in elderly Chinese populations. Considering the impact of the dramatic increase in the incidence and prevalence of diabetes in China, interventions to improve air quality are urgently needed.
Societal Violence, National Identification, and Anti-Immigrant Sentiment: A Cross-national Study
Authors: Kim Harris Hyun-Soo
Published: August 2022

Existing research shows that anti-immigrant attitudes are driven by a wide variety of individual- and contextual-level factors. The present study introduces “societal violence”—the degree to which human rights are violated and physical survival is threatened in society—as a significant, yet neglected, explanatory concept in analyzing negative attitudes toward immigrants. Data are drawn from the International Social Survey Programme (ISSP) 2013. Two-level mixed effects models are estimated with random intercepts and slopes. Results show that societal violence significantly moderates the magnitude of the relationships between measures of national identification and negative sentiment toward immigrant among 27 280 respondents across 29 low- and high-income countries. More specifically, the associations are found to be greater in less violent societies.
The economics of patients undergoing periacetabular osteotomy for hip dysplasia: the financial relationship between physicians and hospitals
Authors: Alter Thomas , Fitch Ashlyn , Bailey Terhune E , Williams Joel C
Published: August 2022

Periacetabular osteotomy (PAO) is the gold standard for treating hip dysplasia in patients with preserved articular cartilage. The aim of this study is to evaluate the financial relationship between facility and professional revenue for patients undergoing PAO for hip dysplasia and acetabular version abnormalities. All patients who underwent PAO for hip dysplasia by a single surgeon at a tertiary academic medical center between December 2016 and November 2020 were identified. Financial records for facility and professional services were reviewed and analyzed. The orthopedic charge multiplier, the dollars of facility charge created by a single dollar of orthopedic professional charge, and orthopedic net revenue multiplier, the dollars collected by the hospital for facility services generated for each dollar collected by the orthopedic surgeon, were calculated. A total of 36 patients were included in the study. The mean total charge for all patients was $144 939.35 ± $23 726.48 (range $109 002.71 to $227 290.20), and the average total revenue for all patients was $44 218.79 ± $12 352.97 (range $29 397.39 to $90,830.62). The mean orthopedic charge multiplier was 2.47 ± 1.32 (range 0.78–6.53), and the net revenue collection multiplier was 8.62 ± 10.69 (range, 1.20–57.80). The majority of charges and revenue related to care of patients undergoing PAO return to the hospital. The significant mean orthopedic charge multiplier for this procedure increases the value of the service and the surgeon to hospital profitability. This information can help shape the relationship between the hospital and the surgeon and create a firm platform to advocate for program advancement.
Volcanic Exoplanet Surfaces
Authors: Fortin Marc-Antoine , Gazel Esteban , Kaltenegger Lisa , Holycross Megan E
Published: August 2022

Recent measurements of the reflection of the surface of a lava world provides an unprecedented opportunity to investigate different stages of rocky planet evolution. The spectral features of the surfaces of rocky exoplanets give insights into their evolution and inner workings. However, no data base exists yet that contains spectral reflectivity and emission of a wide range of potential volcanic exoplanet surface materials. Here, we first synthesized 16 possible exoplanet surfaces, spanning a wide range of chemical compositions based on potential mantle material of volcanic exoplanets guided by the metallicity of different host stars. Then, we measured their infrared reflection spectrum (2.5–28 μm), from which we obtained their emission spectra, and established the link between the composition and a strong spectral feature at 8 μm, the Christiansen feature (CF). Our analysis suggests a new multicomponent composition relationship with the CF as well as a correlation with the silica content of the exoplanet mantle. We also report the mineralogies of these materials, as possibilities for volcanic worlds. This data base is a tool to aid in the interpretation of future spectra of volcanic and lava worlds that will be collected by the James Webb Space Telescope and other missions.
Interstellar extinction correction in ionized regions using He i lines
Authors: Zamora S , Díaz Ángeles I , Terlevich Elena , Fernández Vital
Published: August 2022

The logarithmic extinction coefficient, c(H β), is usually derived using the H α/H β ratio for case B recombination and assuming standard values of electron density and temperature. However, the use of strong Balmer lines can lead us to selection biases when studying regions with different surface brightness, such as extended nebulae, with the use of single integral field spectroscopy observations, since, in some cases, the H α line can be saturated in moderate to long exposures. In this work, we present a method to derive extinction corrections based only on the weaker lines of He i, taking into account the presence of triplet states in these atoms and its influence on recombination lines. We have applied this procedure to calculate the extinction of different regions of the 30 Doradus nebula from MUSE integral-field spectroscopy data. The comparison between helium and hydrogen c(H β) determinations has been found to yield results fully compatible within the errors and the use of both sets of lines simultaneously reduces considerably the error in the derivation.