Mussels have a remarkable ability to bond to solid surfaces under water. From a microscopic perspective, the first step of this process is the adsorption of dopa molecules to the solid surface. In fact, it is the catechol part of the dopa molecule that is interacting with the surface. These molecules are able to make reversible bonds to a wide range of materials, even underwater. Previous experimental and theoretical efforts have produced only a limited understanding of the mechanism and quantitative details of the competitive adsorption of catechol and water on hydrophilic silica surfaces. In this work, we uncover the nature of this competitive absorption by atomic scale modeling of water and catechol adsorbed at the geminal (001) silica surface using density functional theory calculations. We find that catechol molecules displace preadsorbed water molecules and bond directly on the silica surface. Using molecular dynamics simulations, we observe this process in detail. We also calculate the interaction force as a function of distance, and observe a maximum of 0.5 nN of attraction. The catechol has a binding energy of 23 kcal/mol onto the silica surface with adsorbed water molecules.

BackgroundThis paper constitutes an important ethnobiological survey in the context of utilizing biological resources by residents of Kala Chitta hills of Pothwar region, Pakistan. The fundamental aim of this research endeavour was to catalogue and analyse the indigenous knowledge of native community about plants and animals. The study is distinctive in the sense to explore both ethnobotanical and ethnozoological aspects of indigenous culture, and exhibits novelty, being based on empirical approach of Multinomial Logit Specifications (MLS) for examining ethnobotanical and ethnozoological uses of specific plants and animals.MethodsTo document the ethnobiological knowledge, the survey was conducted during 2011–12 by employing a semi-structured questionnaire and thus 54 informants were interviewed. Plant and animal specimens were collected, photographed and properly identified. Distribution of plants and animals were explored by descriptive and graphical examination. MLS were further incorporated to identify the probability of occurrence of diversified utilization of plants and animals in multipurpose domains.ResultsTraditional uses of 91 plant and 65 animal species were reported. Data analysis revealed more medicinal use of plants and animals than all other use categories. MLS findings are also in line with these proportional configurations. They reveal that medicinal and food consumption of underground and perennial plants was more as compared to aerial and annual categories of plants. Likewise, medicinal utilization of wild animals and domestic animals were more commonly observed as food items. However, invertebrates are more in the domain of medicinal and food utilization. Also carnivores are fairly common in the use of medicine while herbivores are in the category of food consumption.ConclusionThis study empirically scans a good chunk of ethnobiological knowledge and depicts its strong connection with indigenous traditions. It is important to make local residents beware of conservation status of species and authentication of this knowledge needs to be done in near future. Moreover, Statistically significant findings impart novelty in the existing literature in the field of ethnobiology. Future conservation, phytochemical and pharmacological studies are recommended on these identified plants and animals in order to use them in a more sustainable and effective way.

BackgroundThis paper reflects the empirical findings of an ethnobotanical survey which was undertaken in Patriata (New Murree) of district Rawalpindi in Pakistan. The aims and objectives of the study were to document indigenous knowledge of plants particularly of medicinal, veterinary, fruit, vegetable, fodder, fuel etc.MethodsFor this purpose, the whole area was surveyed for documenting folk knowledge using a semi-structured questionnaire. A total of 93 plants species belonging to 80 genera and 56 families were found in a variety of uses by the local people for the accomplishment of their basic needs. The study further employs binary logit regression model of medicinal uses of these plants so as to identify the probability of occurrence of medicinal use of woody or non-woody plants keeping other plant characteristics in view.ResultsEthnobotanical data shows that most plants are used for medicinal and fodder purposes (27.93% each), followed by fuel (16.90%), fruit (6.55%), vegetable (5.52%) and ethno-veterinary (3.79%). There is also an established association of medicinal use of plants to the fruits use. Non-woody plants have high tendency towards medicinal use of the plants as compared to woody plants. Annual plants are less likely to be directly associated with medicinal use of plants in the surveyed vegetation. Underground plant parts are more likely to be used for medicinal purposes as revealed from the Logit expressions.ConclusionsThe study revealed that most of the plants are used for medicinal and fodder purposes. The results of Logit Model showed that the probabilities of plant species for their medicinal use are associated to the woody or non-woody, aerial or underground, perennial or annual characteristics of plants. One should be careful in completely generalizing the results as the survey findings are sensitive to the plant species and the vegetation under consideration. But it can be specified that there exists either some positive or negative association of medicinal use of plants to the various characteristics of plant species.

Nearly monodisperse poly(N‐isopropylacrylamide‐co‐acrylamide) [P(NIPAM‐co‐AAm)] microgels were synthesized using precipitation polymerization in aqueous medium. These microgels were used as microreactors to fabricate silver nanoparticles by chemical reduction of silver ions inside the polymer network. The pure and hybrid microgels were characterized using Fourier transform infrared and UV–visible spectroscopies, dynamic light scattering, X‐ray diffraction, thermogravimetric analysis, differential scanning calorimetry and transmission electron microscopy. Results revealed that spherical silver nanoparticles having diameter of 10–20 nm were successfully fabricated in the poly(N‐isopropylacrylamide‐co‐acrylamide) microgels with hydrodynamic diameter of 250 ± 50 nm. The uniformly loaded silver nanoparticles were found to be stable for long time due to donor–acceptor interaction between amide groups of polymer network and silver nanoparticles. Catalytic activity of the hybrid system was tested by choosing the catalytic reduction of 4‐nitrophenol as a model reaction under various conditions of catalyst dose and concentration of NaBH4 at room temperature in aqueous medium to explore the catalytic process. The progress of the reaction was monitored using UV–visible spectrophotometry. The pseudo first‐order kinetic model was employed to evaluate the apparent rate constant of the reaction. It was found that the apparent rate constant increased with increasing catalyst dose due to an increase of surface area as a result of an increase in the number of nanoparticles.

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