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1.
Front Physiol ; 15: 1350051, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38523807

RESUMEN

Background: Optic nerve sheath diameter (ONSD) increases significantly at high altitudes, and is associated with the presence and severity of acute mountain sickness (AMS). Exposure to hypobaria, hypoxia, and coldness when hiking also impacts intraocular pressure (IOP). To date, little is known about ocular physiological responses in trekkers with myopia at high altitudes. This study aimed to determine changes in the ONSD and IOP between participants with and without high myopia (HM) during hiking and to test whether these changes could predict symptoms of AMS. Methods: Nine participants with HM and 18 without HM participated in a 3-day trek of Xue Mountain. The ONSD, IOP, and questionnaires were examined before and during the trek of Xue Mountain. Results: The ONSD values increased significantly in both HM (p = 0.005) and non-HM trekkers (p = 0.018) at an altitude of 1,700 m. In the HM group, IOP levels were greater than those in the non-HM group (p = 0.034) on the first day of trekking (altitude: 3,150 m). No statistically significant difference was observed between the two groups for the values of ONSD. Fractional changes in ONSD at an altitude of 1,700 m were related to the development of AMS (r pb = 0.448, p = 0.019) and the presence of headache symptoms (r pb = 0.542, p = 0.004). The area under the ROC curve for the diagnostic performance of ONSD fractional changes at an altitude of 1,700 m was 0.859 for predicting the development of AMS and 0.803 for predicting the presence of headache symptoms. Conclusion: Analysis of changes in ONSD at moderate altitude could predict AMS symptoms before an ascent to high altitude. Myopia may impact physiological accommodation at high altitudes, and HM trekkers potentially demonstrate suboptimal regulation of aqueous humor in such environments.

2.
Adv Mater ; 35(18): e2211673, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36932878

RESUMEN

As the soaring demand for energy storage continues to grow, batteries that can cope with extreme conditions are highly desired. Yet, existing battery materials are limited by weak mechanical properties and freeze-vulnerability, prohibiting safe energy storage in devices that are exposed to low temperature and unusual mechanical impacts. Herein, a fabrication method harnessing the synergistic effect of co-nonsolvency and "salting-out" that can produce poly(vinyl alcohol) hydrogel electrolytes with unique open-cell porous structures, composed of strongly aggregated polymer chains, and containing disrupted hydrogen bonds among free water molecules, is introduced. The hydrogel electrolyte simultaneously combines high strength (tensile strength 15.6 MPa), freeze-tolerance (< -77 °C), high mass transport (10× lower overpotential), and dendrite and parasitic reactions suppression for stable performance (30 000 cycles). The high generality of this method is further demonstrated with poly(N-isopropylacrylamide) and poly(N-tertbutylacrylamide-co-acrylamide) hydrogels. This work takes a further step toward flexible battery development for harsh environments.

4.
Phys Chem Chem Phys ; 23(3): 2305-2312, 2021 Jan 28.
Artículo en Inglés | MEDLINE | ID: mdl-33449065

RESUMEN

We comprehensively investigated the hydrogen evolution reaction (HER) activity of a series of transition metal phosphides (MPs) (M = Cr, Mn, Fe, Co, and Ni) using first-principles calculations. The free energy difference was calculated for possible sites on the surface to pinpoint the reactive sites and the associated catalytic activities. We found that the chemical properties of these considered MPs are different from those of WP, including CrP which has the same electronic configuration as WP but was shown not to be a good electrocatalyst. Different reactive sites other than WP were predicted, and notably, unlike WP, phosphorus can participate/catalyze the HER on the considered MP. Among these MPs, there are more active sites on FeP, CoP, and NiP than CrP and MnP. Our electronic structure analysis suggests that the spin polarization is critical in determining the hydrogen adsorption and hence the HER performance. We further explored the HER of metal- or phosphorus-deficit MPs, as samples can be grown under different conditions. In particular, phosphorus-deficit FeP, CoP, and NiP were found to have enhanced HER performance, with either better catalytic activities or more active sites. Therefore, we proposed that controlling of these defects can be an effective approach to tune the HER catalytic ability of these MPs. It can serve as the design principle to synthesize new MP based electrocatalysts.

5.
Small ; 17(8): e2006153, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33512059

RESUMEN

A new family of transition-metal monosilicides (MSi, M = Ti, Mn, Fe, Ru, Ni, Pd, Co, and Rh) electrocatalysts with superior electrocatalytic performance of hydrogen evolution is reported, based on the computational and experimental results. It is proposed that these MSi can be synthesized within several minutes by adopting the arc-melting method. The previously reported RuSi is not only fabricated more readily but eventually explored 8 MSi that can be good hydrogen evolution reaction catalysts. Silicides then can be another promising electrocatalysts family as carbides, wherein carbon has the same electronic configuration as silicon. All explored silicides electrodes exhibited low overpotentials (34-54 mV at 10 mA cm-2 ) with Tafel slopes from 23.6 to 32.3 mV dec-1 , which are comparable to that of the commercial 20 wt% Pt/C (37 mV, 26.1 mV dec-1 ). First-principles calculations demonstrated that the superior performance can be attributed to the high catalytic reactivity per site that can even function at high hydrogen coverages (≈100%) on multiple low surface energy facets. The work sheds light on a new class of electrocatalysts for hydrogen evolution, with earth-abundant and inexpensive silicon-based compounds.

6.
ACS Appl Mater Interfaces ; 11(12): 11144-11156, 2019 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-30883079

RESUMEN

Boron neutron capture therapy (BNCT) is a promising radiotherapy for treating glioblastoma multiforme (GBM). However, the penetration of drugs (e.g., sodium borocaptate and BSH) for BNCT into brain tumors is limited by cerebral vesicular protective structures, the blood-brain barrier, and the blood-brain tumor barrier (BTB). Although BSH has been reported to be selectively taken up by tumors, it is rapidly excreted from the body and cannot achieve a high tumor-to-normal brain ratio (T/N ratio) and tumor-to-blood ratio (T/B ratio). Despite the development of large-molecular weight boron compounds, such as polymers and nanoparticles, to enhance the permeation and retention effect, their effects remain insufficient for clinical use. To improve the efficiency of boron delivery to the tumor site, we propose combinations of self-assembled boron-containing polyanion [polyethylene glycol- b-poly(( closo-dodecaboranyl)thiomethylstyrene) (PEG- b-PMBSH)] nanoparticles (295 ± 2.3 nm in aqueous media) coupled with cationic microbubble (B-MB)-assisted focused ultrasound (FUS) treatment. Upon FUS sonication (frequency = 1 MHz, pressure = 0.3-0.7 MPa, duty cycle = 0.5%, sonication = 1 min), B-MBs can simultaneously achieve safe BTB opening and boron drug delivery into tumor tissue. Compared with the MBs of the PEG- b-PMBSH mixture group (B + MBs), B-MBs showed 3- and 2.3-fold improvements in the T/N (4.4 ± 1.4 vs 1.3 ± 0.1) and T/B ratios (1.4 ± 0.6 vs 0.1 ± 0.1), respectively, after 4 min of FUS sonication. The spatial distribution of PEG- b-PMBSH was also improved by the complex of PEG- b-PMBSH with MBs. The findings presented herein, in combination with the expanding clinical application of FUS, may improve BNCT and treatment of GBM.


Asunto(s)
Terapia por Captura de Neutrón de Boro , Boro/química , Microburbujas , Polímeros/química , Animales , Barrera Hematoencefálica/metabolismo , Neoplasias Encefálicas/patología , Neoplasias Encefálicas/radioterapia , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Glioma/patología , Glioma/radioterapia , Humanos , Membrana Dobles de Lípidos/química , Masculino , Ratones , Ratones Endogámicos C57BL , Nanopartículas/química , Sonicación , Distribución Tisular
7.
Psychol Rep ; 103(1): 161-9, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18982949

RESUMEN

The purpose of this study was to assess the associations between measures of adult attachment and forgiveness in college students in Taiwan. Participants (203 women and 82 men; M age = 19.6 yr., SD = 1.2) completed measures of adult attachment dimensions (Adult Attachment Scale), State Forgiveness (Forgiveness Scale), and Trait Forgiveness (Forgiveness Likelihood Scale). Pearson correlations and regression results indicated ratings on three dimensions of adult attachment, Dependence, Anxiety, and Closeness, were significantly related to State Forgiveness, and all but scores on Dependence were significantly related to scores on Trait Forgiveness. Only ratings of Anxiety and Closeness significantly predicted those on State and Trait Forgiveness. The findings provided partial support for using attachment theory to understand the construct of forgiveness.


Asunto(s)
Culpa , Apego a Objetos , Estudiantes , Universidades , Adulto , Femenino , Humanos , Masculino , Encuestas y Cuestionarios , Taiwán
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