14 research outputs found
Tear trough deformity: different types of anatomy and treatment options
Aim : To explore the efficacy of tear trough deformity treatment with the use of hyaluronic acid gel or autologous fat for soft tissue augmentation and fat repositioning via arcus marginalis release.
Material and methods : Seventy-eight patients with the tear trough were divided into three groups. Class I has tear trough without bulging orbital fat or excess of the lower eyelid skin. Class II is associated with mild to moderate orbital fat bulging, without excess of the lower eyelid skin. Class III is associated with severe orbital fat bulging and excess of the lower eyelid skin. Class I or II was treated using hyaluronic acid gel or autologous fat injections. Class III
was treated with fat repositioning via arcus marginalis release. The patients with a deep nasojugal groove of class III
were treated with injecting autologous fat into the tear trough during fat repositioning lower blepharoplasty as a way of supplementing the volume added by the repositioned fat.
Results : Seventy-eight patients with tear trough deformity were confirmed from photographs taken before and after surgery. There were some complications, but all had complete resolution.
Conclusions : Patients with mild to moderate peri-orbital volume loss without severe orbital fat bulging may be good candidates for hyaluronic acid filler or fat grafting alone. However, patients with more pronounced deformities, severe orbital fat bulging and excess of the lower eyelid skin are often better served by fat repositioning via arcus marginalis release and fat grafting
A Bidirectional Same Sense Circularly Polarized Endfire Antenna Array With Polarization Reconfigurability
Dissipation Dynamics and Dietary Risk Assessment of Four Fungicides as Preservatives in Pear
Fungicides, including thiophanate-methyl, tebuconazole, pyraclostrobin, and difenoconazole, have been widely used as preservatives to control fungal diseases during pear storage. However, the metabolic capability of pear for exogenous compounds decreases at lower storage temperatures, leading to an increase in the risk of exposure to chemical preservatives. In this work, a sensitive and stable ultraperformance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) analytical method was established to investigate the dissipation dynamics and dietary intake risk of four chemical preservatives in pears under different conditions. The mean recoveries of the preservatives in pear samples ranged from 73.2% to 117.1%, with relative standard deviations of 0.5–7.2%. The dissipation half-lives (T1/2) of thiophanate-methyl, tebuconazole, pyraclostrobin, and difenoconazole in pears were 7.2–21.1 d and 31.6–173.3 d at storage temperatures of 25 °C and 4 °C, respectively. The results of dietary risk evaluation showed that the intake risk of preservatives in commercial pears was acceptable. However, some pears from commercial supermarkets still contained preservatives at amounts that exceeded the maximum residue limit (MRL) set by the Chinese government. This work provides a guideline for the risk evaluation of fruit preservatives on human health
Dissipation Dynamics and Dietary Risk Assessment of Four Fungicides as Preservatives in Pear
Fungicides, including thiophanate-methyl, tebuconazole, pyraclostrobin, and difenoconazole, have been widely used as preservatives to control fungal diseases during pear storage. However, the metabolic capability of pear for exogenous compounds decreases at lower storage temperatures, leading to an increase in the risk of exposure to chemical preservatives. In this work, a sensitive and stable ultraperformance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) analytical method was established to investigate the dissipation dynamics and dietary intake risk of four chemical preservatives in pears under different conditions. The mean recoveries of the preservatives in pear samples ranged from 73.2% to 117.1%, with relative standard deviations of 0.5–7.2%. The dissipation half-lives (T1/2) of thiophanate-methyl, tebuconazole, pyraclostrobin, and difenoconazole in pears were 7.2–21.1 d and 31.6–173.3 d at storage temperatures of 25 °C and 4 °C, respectively. The results of dietary risk evaluation showed that the intake risk of preservatives in commercial pears was acceptable. However, some pears from commercial supermarkets still contained preservatives at amounts that exceeded the maximum residue limit (MRL) set by the Chinese government. This work provides a guideline for the risk evaluation of fruit preservatives on human health
Unexpected Dehydrogenation Behaviors of the 2LiBH<sub>4</sub>–MgH<sub>2</sub> Composite Confined in a Mesoporous Carbon Scaffold
Nanoconfinement has been widely employed
as a promising strategy
to improve dehydrogenation kinetics, reversibility, and equilibrium
pressure of complex metal hydrides. In this paper, we report a careful
study of the influence of nanoconfinement on the reversible dehydrogenation
property and reaction mechanism pathway of the 2LiBH<sub>4</sub>–MgH<sub>2</sub> composite system. Compared to the bulk 2LiBH<sub>4</sub>–MgH<sub>2</sub> composite, the 2LiBH<sub>4</sub>–MgH<sub>2</sub> confined
in the mesoporous carbon (CMK-3) scaffold host exhibits the significantly
enhanced dehydrogenation kinetics but meanwhile shows the serious
loss of hydrogen capacity upon cycling, particularly in the first
two cycles. Moreover, the observed dehydrogenation property is independent
of the hydrogen back pressure. The combination analyses of XRD, FTIR,
and NMR definitely detected the dominant Mg and B phases in the dehydrogenation
products, suggesting the mainly individual desorption of MgH<sub>2</sub> and LiBH<sub>4</sub> in the confined 2LiBH<sub>4</sub>–MgH<sub>2</sub> system. This unfavorable change of the dehydrogenation reaction
pathway would result in the poor reversibility, which is not expected
for the combined hydride systems. These findings might provide renewed
insight into the nanoconfinement effect on the hydrogen storage property
for multiple phase combined systems
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Revealing the effect of LiOH on forming a SEI using a Co magnetic probe.
The solid-electrolyte-interphase (SEI) plays a critical role in lithium-ion batteries (LIBs) because of its important influence on electrochemical performance, such as cycle stability, coulombic efficiency, etc. Although LiOH has been recognized as a key component of the SEI, its influence on the SEI and electrochemical performance has not been well clarified due to the difficulty in precisely controlling the LiOH content and characterize the detailed interface reactions. Here, a gradual change of LiOH content is realized by different reduction schemes among Co(OH)2, CoOOH and CoO. With reduced Co nanoparticles as magnetic probes, SEI characterization is achieved by operando magnetometry. By combining comprehensive characterization and theoretical calculations, it is verified that LiOH leads to a composition transformation from lithium ethylene di-carbonate (LEDC) to lithium ethylene mono-carbonate (LEMC) in the SEI and ultimately results in capacity decay. This work unfolds the detailed SEI reaction scenario involving LiOH, provides new insights into the influence of SEI composition, and has value for the co-development between the electrode materials and electrolyte
Compact-Nanobox Engineering of Transition Metal Oxides with Enhanced Initial Coulombic Efficiency for Lithium-Ion Battery Anodes
A novel
strategy is proposed to construct a compact-nanobox (CNB) structure
composed of irregular nanograins (average diameter ≈ 10 nm),
aiming to confine the electrode–electrolyte contact area and
enhance initial Coulombic efficiency (ICE) of transition metal oxide
(TMO) anodes. To demonstrate the validity of this attempt, CoO-CNB
is taken as an example which is synthesized via a carbothermic reduction
method. Benefiting from the compact configuration, electrolyte can
only contact the outer surface of the nanobox, keeping the inner CoO
nanograins untouched. Therefore, the solid electrolyte interphase
(SEI) formation is reduced. Furthermore, the internal cavity leaves
enough room for volume variation upon lithiation and delithiation,
resulting in superior mechanical stability of the CNB structure and
less generation of fresh SEI. Consequently, the SEI remains stable
and spatially confined without degradation, and hence, the CoO-CNB
electrode delivers an enhanced ICE of 82.2%, which is among the highest
values reported for TMO-based anodes in lithium-ion batteries. In
addition, the CoO-CNB electrode also demonstrates excellent cyclability
with a reversible capacity of 811.6 mA h g<sup>–1</sup> (90.4%
capacity retention after 100 cycles). These findings open up a new
way to design high-ICE electrodes and boost the practical application
of TMO anodes