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1.
Front Plant Sci ; 14: 1095888, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36794215

RESUMEN

Wood anatomy and plant hydraulics play a significant role in understanding species-specific responses and their ability to manage rapid environmental changes. This study used the dendro-anatomical approach to assess the anatomical characteristics and their relation to local climate variability in the boreal coniferous tree species Larix gmelinii (Dahurian larch) and Pinus sylvestris var. mongolica (Scots pine) at an altitude range of 660 m to 842 m. We measured the xylem anatomical traits (lumen area (LA), cell wall thickness (CWt), cell counts per ring (CN), ring width (RW), and cell sizes in rings) of both species at four different sites Mangui (MG), Wuerqihan (WEQH), Moredagha (MEDG) and Alihe (ALH) and investigated their relationship with temperature and precipitation of those sites along a latitude gradient. Results showed that all chronologies have strong summer temperature correlations. LA extremes were mostly associated with climatic variation than CWt and RWt. MEDG site species showed an inverse correlation in different growing seasons. The correlation coefficient with temperature indicated significant variations in the May-September months at MG, WEQH, and ALH sites. These results suggest that climatic seasonality changes in the selected sites positively affect hydraulic efficiency (increase in the diameter of the earlywood cells) and the width of the latewood produced in P. sylvestris. In contrast, L. gmelinii showed the opposite response to warm temperatures. It is concluded that xylem anatomical responses of L. gmelinii and P. sylvestris showed varied responses to different climatic factors at different sites. These differences between the two species responses to climate are due to the change of site condition on a large spatial and temporal scale.

2.
ACS Appl Mater Interfaces ; 14(2): 3334-3343, 2022 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-34981919

RESUMEN

Icephobic coatings have been extensively studied for decades to overcome the potential damage associated with ice formation in various devices that are operated under harsh weather conditions. Superhydrophobic surface coatings have been applied for icephobic coating applications owing to their low surface energy. In this study, an icephobic coating of a self-formed superhydrophobic surface using polydimethylsiloxane (PDMS) and SiO2 powder was investigated. The effect of superhydrophobicity on icephobicity was determined by varying the experimental parameters. Polyvinylidene fluoride (PVDF) was added to the PDMS solution to improve the mechanical properties of the icephobic layer. The PDMS-PVDF solution also showed a self-formation behavior into a superhydrophobic surface. In addition, the icephobicity and mechanical properties of the PDMS-PVDF mixture coating improved because of the multilevel nanostructure formed by physical and chemical interactions between the mixture and SiO2 powder. We believe that the proposed approach will be a suitable candidate for various practical applications of icephobicity and a model system to understand the correlation between superhydrophobicity and icephobicity.

3.
Nanomaterials (Basel) ; 11(7)2021 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-34361180

RESUMEN

Humid conditions can disrupt the triboelectric signal generation and reduce the accuracy of triboelectric mechanical sensors. This study demonstrates a novel design approach using atomic layer deposition (ALD) to enhance the humidity resistance of triboelectric mechanical sensors. Titanium oxide (TiOx) was deposited on polytetrafluoroethylene (PTFE) film as a moisture passivation layer. To determine the effective ALD process cycle, the TiOx layer was deposited with 100 to 2000 process cycles. The triboelectric behavior and surface chemical bonding states were analyzed before and after moisture exposure. The ALD-TiOx-deposited PTFE showed three times greater humidity stability than pristine PTFE film. Based on the characterization of TiOx on PTFE film, the passivation mechanism was proposed, and it was related to the role of the oxygen-deficient sites in the TiOx layer. This study could provide a novel way to design stable triboelectric mechanical sensors in highly humid environments.

4.
Langmuir ; 37(17): 5356-5363, 2021 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-33890793

RESUMEN

The superhydrophobic surface has been used in ultradry surface applications, such as the maritime industry, windshields, non-sticky surfaces, anti-icing surfaces, self-cleaning surfaces, and so forth. However, one of the main hurdles for the production of superhydrophobic surfaces is high-cost fabrication methods. Here, we report a handy process of self-synthesis fabrication of superhydrophobic surfaces with daily supplies. Driven by the physics of biscuit dunking, we introduce a method to self-synthesize superhydrophobic surfaces from daily supplies by coating a substrate with a liquid (liquids of paraffin from candles or polydimethylsiloxane) and subsequently sprinkling powders (food-desiccant silica, alumina, sugar, salt, or flour). A mechanistic study revealed that the capillary force, governed by surface energy difference, liquid viscosity, and powder pore size, draws the liquid solution into the porous channels within the powders. The entire surface of powders, in turn, is covered with the low-surface-energy liquid to maintain the porosity, creating a 3D porous nanostructure, resulting in a water contact angle over 160°. This work provides a scientific understanding that technological developments are closely related to the science that can be seen in our daily lives. Also, we believe that further intensive studies extended from this work could enable to home-fabricate a superhydrophobic surface, such as a bathtub and sink in bathrooms and a cooking area and sink in kitchens.

5.
Pak J Med Sci ; 36(7): 1529-1532, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33235569

RESUMEN

OBJECTIVES: To determine relationship between immediate postpartum umbilical cord pH, fetal distress and neonatal outcome. METHODS: This descriptive cross-sectional study was conducted in the department of Gynaecology, Lady Reading Hospital Peshawar, Pakistan, from January 2019 to July 2019. This study included 27 full-term pregnant women who had abnormal CTG during the active or latent phase of labour. Data were analyzed by IBM SPSS Statistics for Windows, Version 23.0. RESULTS: Out of 27, most patients 13 (48.14%) were in the age group 20-25 years,11 (40.74%) to 26-30 years and 3 (11.11%) belonged to 31-35 years of age group. CTG abnormalities were severe bradycardia, late deccelerations and persistent variable deccelerations with loss of baseline variability. Of all delivered babies, 21 (77%) babies had birth weight<3.5 kg and 6 (22%) had >3.5 kg birth weight. 20 (74.07%) had acidosis (pH <7.2) at the time of birth, of which one had severe hypoxemia and acidosis with pH 6.85. APGAR score at 0 minutes showed a strong positive correlation (r=0.818, p= <0.001) with cord pH, while APGAR at five minutes was also strongly correlated (r= 773, p=<0.001). Of all babies 18(66.66%) with PH less than 7.2 were admitted in NICU while only 2 babies with PH more than 7.2 were admitted. (p value= 0.005). CONCLUSION: Low umbilical cord pH values of babies born by cesarean section (for fetal distress) are strongly correlated with low APGAR score at birth and higher rates of NICU admission.

6.
Bull Environ Contam Toxicol ; 101(6): 787-795, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30250970

RESUMEN

This study focused on evaluating the metal and metalloid contamination and associated risks in the two vegetables crops, coriander (Coriandrum sativum) and spinach (Spinacia oleracea) treated with three water regimes, canal water, groundwater and municipal wastewater. These vegetables are widely consumed by people and are also used in traditional medicine for treating various disorders. Metal and metalloid accumulation (Zn, Pb, Se, Cu, As, Mo, Fe, Ni) was found higher in vegetables treated with wastewater. Wastewater treated soil had high pollution load index. Fe, Zn, As and Pb had higher values in water, soil and vegetables as compared to other studied metals. Overall, metal correlation for soil and vegetables was significant and positive except for Fe and Cu in spinach. The highest value for daily metal intake was estimated for Fe while Se had the lowest value for the same index. It was thus concluded that trace metal and metalloid accumulation was a major health concern for the public consuming these vegetables.


Asunto(s)
Coriandrum/química , Spinacia oleracea/química , Verduras/química , Aguas Residuales/análisis , Productos Agrícolas/química , Monitoreo del Ambiente , Contaminación de Alimentos/análisis , Humanos , Metaloides/análisis , Metales Pesados/análisis , Medición de Riesgo , Suelo/química , Contaminantes del Suelo/análisis , Oligoelementos/análisis
7.
Chemosphere ; 166: 157-162, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-27693923

RESUMEN

Metal buildup was estimated in potato (Solanum tuberosum L.), grown in central Punjab, Pakistan. This crop was irrigated with multiple water sources like ground, sewage and canal water. Concentrations of different metals like zinc (Zn), arsenic (As), lead (Pb), iron (Fe), nickel (Ni), molybdenum (Mo), copper (Cu), and selenium (Se) were assessed in the potato crop irrigated with different types of waters. Sewage water treated crop and soil had higher metal concentrations than those treated with other two treatments. All metals had positive and significant correlation except for Mo which was non-significantly correlated between the vegetable and soil. Highest daily intake was observed for Fe (0.267), whereas the lowest was seen for Se (0.003). The enrichment factor and health index varied between 0.135-15.08 and 0.285-83.77, respectively. This study concludes that vegetables cultivated on soil treated with sewage water is a potent threat for human health as the metals manifest toxicity after entering the food chain.


Asunto(s)
Metales Pesados/análisis , Contaminantes del Suelo/análisis , Solanum tuberosum/química , Solanum tuberosum/crecimiento & desarrollo , Humanos , Metales Pesados/toxicidad , Pakistán , Medición de Riesgo , Aguas del Alcantarillado/química , Contaminantes del Suelo/toxicidad , Solanum tuberosum/efectos de los fármacos , Verduras/química , Verduras/crecimiento & desarrollo
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