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1.
Science ; 382(6677): 1399-1404, 2023 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-37995210

RESUMEN

The power conversion efficiency (PCE) of inverted perovskite solar cells (PSCs) is still lagging behind that of conventional PSCs, in part because of inefficient carrier transport and poor morphology of hole transport layers (HTLs). We optimized self-assembly of [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphonic acid (Me-4PACz) onto nickel oxide (NiOx) nanoparticles as an HTL through treatment with hydrogen peroxide, which created a more uniform dispersion of nanoparticles with high conductivity attributed to the formation of Ni3+ as well as surface hydroxyl groups for bonding. A 25.2% certified PCE for a mask size of 0.074 square centimeters was obtained. This device maintained 85.4% of the initial PCE after 1000 hours of stabilized power output operation under 1 sun light irradiation at about 50°C and 85.1% of the initial PCE after 500 hours of accelerated aging at 85°C. We obtained a PCE of 21.0% for a minimodule with an aperture area of 14.65 square centimeters.

2.
J Food Sci ; 88(6): 2536-2556, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37125946

RESUMEN

The non-Newtonian fluid-solid interaction food has complex physical properties and complicated contact force, which brings the greater technical challenge to improving the food fetching rate. In this work, we used the smooth particle hydrodynamics and finite element coupling method for a node-to-surface penalty function contact to characterize the contact forces between non-Newtonian fluid food and solid foods. The shear rheological properties and density of non-Newtonian fluid food, including xanthan gum (XG) and guar gum (GG), were investigated by a viscometer and densitometer, respectively. The results showed that the shear viscosity of non-Newtonian fluid food depends to some extent on the mass ratio of the thickening gums. We investigated the effects of the end-effector with different fetching velocities and different inclination angles, and the nut root powder paste (NRPP) food with different ratios of XG and GG, on the fetching rate, stress-strain, and motion behavior. The results showed that the stress increased with increasing v1 and w; however, the v2 had less effect on the stress. The sparseness of the distribution of solid food was related to the v1 and w, whereas it was less influenced by the v2 . The distribution of solid food became denser in the X-Z plane and sparser in the X-Y plane with increasing inclination angle. The motion behavior of viscoelastic solid foods depended on the mass ratio of XG to GG dissolved in NRPP. The present work can provide a theoretical foundation for meal-assisting robots and robots in the field of food engineering with the task of improving the food fetching rate.


Asunto(s)
Viscosidad , Reología
3.
Front Biosci (Landmark Ed) ; 27(1): 4, 2022 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-35090309

RESUMEN

OBJECTIVE: To evaluate the effect of 0.2% ambroxol eye drop on tear secretion and corneal healing on a rabbit dry eye model, and to delineate potential underlying mechanisms. MATERIALS AND METHOD: A mixed mechanism dry eye model was created using 12 healthy New Zealand rabbits by excision of the main lacrimal glands, Harderian gland and nictitating membrane. Establishment of the model was confirmed by the decrease of Schirmer I and increase of corneal fluorescein staining scores. Two weeks after model creation, the rabbits were randomly and evenly divided into NaCl, 0.1% sodium hyaluronate and 0.2% ambroxol groups. Each group was administered the respective eye drops 4 times a day for four weeks. The Schirmer I test and corneal fluorescein staining were performed at two and four weeks. After four weeks of treatment, the animals were sacrificed and the conjunctiva and eyelid specimens collected. Inflammatory factors IL-8, TNF-α, and goblet cell specific mucin MUC5AC were measured by ELISA while the lid meibomian gland was evaluated by oil red O staining. RESULTS: Compared with the baseline, 2 weeks after the surgery, Schirmer I test value decreased significantly (20.35 ± 5.18 mm/5 min vs 13.95 ± 4.64 mm/5 min, p < 0.01), and the fluorescein staining score increased significantly (0.5 ± 0.6 vs 5.5 ± 1.4, p < 0.01). After four weeks of treatment, compared with the NaCl and sodium hyaluronate groups, tear secretion in ambroxol group increased significantly (p < 0.01), while the corneal fluorescence staining score decreased significantly (p < 0.01). In the conjunctival tissue, significant decrease was seen in TNF-α (p < 0.01) and IL-8 [p (unilateral) < 0.05] concentrations in ambroxol group, and significant increase in MUC5AC concentration (p < 0.01) in ambroxol group as well. The lipid content in the lid meibomian glands appeared increased after the administration of ambroxol. CONCLUSION: The present rabbit dry eye model study demonstrated potentials of topically administered 0.2% ambroxol in stimulating tear and mucin secretion, inhibiting ocular surface inflammation, promoting corneal healing, and possibly augmenting meibomian gland lipid production.


Asunto(s)
Ambroxol , Síndromes de Ojo Seco , Animales , Conejos , Ambroxol/metabolismo , Córnea/metabolismo , Síndromes de Ojo Seco/tratamiento farmacológico , Síndromes de Ojo Seco/metabolismo , Glándulas Tarsales/metabolismo , Lágrimas/metabolismo
4.
Graefes Arch Clin Exp Ophthalmol ; 259(6): 1529-1538, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33512613

RESUMEN

PURPOSE: To investigate if topical administration of ambroxol promotes tear secretion and to compare with Diquas ophthalmic eye drop. METHODS: Two consecutive studies were conducted using sixteen (32 eyes) New Zealand White rabbits. The first study compared the efficacy of ambroxol hydrochloride (0.05%, 0.2%, and 1.0%) on tear and mucin secretion when administered twice daily. Tear secretion was assessed by Schirmer test I and mucin production by conjunctival impression cytology and PAS stain. The second study compared 0.2% ambroxol hydrochloride with Diquas. A human goblet cell line and human conjunctival tissue were used to test the effect of ambroxol hydrochloride on the expression of aquaporin 5 (AQP5) and MUC5AC, using reverse transcriptase-quantitative polymerase chain reaction and immunoblotting. RESULTS: All three concentrations of ambroxol hydrochloride demonstrated significant efficacy on tear stimulation within 2 weeks of treatment and total mucin component appeared increased. When administered topically twice daily, 0.2% ambroxol hydrochloride was more effective in augmenting tear secretion than Diquas. With 24 h of treatment, 5 µM of ambroxol hydrochloride upregulated AQP5 and MU5AC mRNA and MUC5AC protein in a goblet cell line. When tested on preserved human conjunctiva tissue, a trend of increased production of MUC5AC protein was seen (P = 0.26). CONCLUSION: Ambroxol is effective in augmenting tear secretion at the ocular surface in rabbits. With actions desirable of a candidate dry eye drug, further investigation of ambroxol and related compounds is warranted to explore their value toward clinical application.


Asunto(s)
Ambroxol , Síndromes de Ojo Seco , Administración Tópica , Ambroxol/uso terapéutico , Animales , Conjuntiva , Síndromes de Ojo Seco/tratamiento farmacológico , Células Caliciformes , Humanos , Mucina 5AC/genética , Soluciones Oftálmicas , Conejos , Lágrimas
5.
BMJ Open ; 8(4): e019549, 2018 04 21.
Artículo en Inglés | MEDLINE | ID: mdl-29680809

RESUMEN

INTRODUCTION: Delirium is a common complication in the elderly after surgery and is associated with worse outcomes. Multiple risk factors are related with postoperative delirium, such as exposure to general anaesthetics, pain and postoperative inflammatory response. Preclinical and clinical studies have shown that dexmedetomidine attenuated neurotoxicity induced by general anaesthetics, improved postoperative analgesia and inhibited inflammatory response after surgery. Several studies found that intraoperative use of dexmedetomidine can prevent postoperative delirium, but data were inconsistent. This study was designed to investigate the impact of dexmedetomidine administered during general anaesthesia in preventing delirium in the elderly after major non-cardiac surgery. METHODS AND ANALYSIS: This is a randomised, double-blinded and placebo-controlled trial. 620 elderly patients (age ≥60 years) who are scheduled to undertake elective major non-cardiac surgery (with an expected duration ≥2 hours) are randomly divided into two groups. For patients in the dexmedetomidine group, a loading dose dexmedetomidine (0.6 µg/kg) will be administered 10 min before anaesthesia induction, followed by a continuous infusion at a rate of 0.5 µg/kg/hour until 1 hour before the end of surgery. For patients in the control group, normal saline will be administered with an identical rate as in the dexmedetomidine group. The primary endpoint is the incidence of delirium during the first five postoperative days. The secondary endpoints include pain intensity, cumulative opioid consumption and subjective sleep quality during the first three postoperative days, as well as the incidence of non-delirium complications and all-cause mortality within 30 days after surgery. ETHICS AND DISSEMINATION: The study protocol was approved by the Clinical Research Ethics Committee of Peking University First Hospital (2015-987) and registered at Chinese Clinical Trial Registry (http://www.chictr.org.cn) with identifier ChiCTR-IPR-15007654. The results of the study will be presented at academic conferences and submitted to peer-reviewed journals. TRIAL REGISTRATION NUMBER: ChiCRR-IPR-15007654; Pre-results.


Asunto(s)
Anestesia General , Delirio , Dexmedetomidina , Hipnóticos y Sedantes , Anciano , Anciano de 80 o más Años , Anestesia General/efectos adversos , Delirio/inducido químicamente , Delirio/prevención & control , Dexmedetomidina/uso terapéutico , Método Doble Ciego , Femenino , Humanos , Hipnóticos y Sedantes/uso terapéutico , Incidencia , Masculino , Persona de Mediana Edad , Dolor Postoperatorio , Complicaciones Posoperatorias
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