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1.
Beilstein J Nanotechnol ; 15: 797-807, 2024.
Article in English | MEDLINE | ID: mdl-38979527

ABSTRACT

We probe the separation of ligands from iron tetracarbonyl methyl acrylate (Fe(CO)4(C4H6O2) or Fe(CO)4MA) induced by the interaction with free electrons. The motivation comes from the possible use of this molecule as a nanofabrication precursor and from the corresponding need to understand its elementary reactions fundamental to the electron-induced deposition. We utilize two complementary electron collision setups and support the interpretation of data by quantum chemical calculations. This way, both the dissociative ionization and dissociative electron attachment fragmentation channels are characterized. Considerable differences in the degree of precursor fragmentation in these two channels are observed. Interesting differences also appear when this precursor is compared to structurally similar iron pentacarbonyl. The present findings shed light on the recent electron-induced chemistry of Fe(CO)4MA on a surface under ultrahigh vacuum.

2.
Beilstein J Nanotechnol ; 15: 500-516, 2024.
Article in English | MEDLINE | ID: mdl-38745584

ABSTRACT

The electron-induced decomposition of Fe(CO)4MA (MA = methyl acrylate), which is a potential new precursor for focused electron beam-induced deposition (FEBID), was investigated by surface science experiments under UHV conditions. Auger electron spectroscopy was used to monitor deposit formation. The comparison between Fe(CO)4MA and Fe(CO)5 revealed the effect of the modified ligand architecture on the deposit formation in electron irradiation experiments that mimic FEBID and cryo-FEBID processes. Electron-stimulated desorption and post-irradiation thermal desorption spectrometry were used to obtain insight into the fate of the ligands upon electron irradiation. As a key finding, the deposits obtained from Fe(CO)4MA and Fe(CO)5 were surprisingly similar, and the relative amount of carbon in deposits prepared from Fe(CO)4MA was considerably less than the amount of carbon in the MA ligand. This demonstrates that electron irradiation efficiently cleaves the neutral MA ligand from the precursor. In addition to deposit formation by electron irradiation, the thermal decomposition of Fe(CO)4MA and Fe(CO)5 on an Fe seed layer prepared by EBID was compared. While Fe(CO)5 sustains autocatalytic growth of the deposit, the MA ligand hinders the thermal decomposition in the case of Fe(CO)4MA. The heteroleptic precursor Fe(CO)4MA, thus, offers the possibility to suppress contributions of thermal reactions, which can compromise control over the deposit shape and size in FEBID processes.

3.
IEEE J Biomed Health Inform ; 27(5): 2288-2295, 2023 05.
Article in English | MEDLINE | ID: mdl-34665750

ABSTRACT

Restrictive public health measures such as isolation and quarantine have been used to reduce the pandemic virus's transmission. With no proper treatment, older adults have been specifically advised to stay home, given their vulnerability to COVID-19. This pandemic has created an increasing need for new and innovative assistive technologies capable of easing the lives of people with special needs. Smart home systems have become widely popular in providing such assistive services to isolated older adults. These systems can provide better services to assist older people if it anticipates what activities inhabitants will perform ahead of time. For example, a smart home can prompt inhabitants to initiate essential activities like taking medicine using activity prediction. This paper proposes a multi-task activity prediction system that jointly predicts labels, locations, and starting times of future activities. The observed sequence of previous activities characterizes future activities. We use body activity information from wearable sensors and motion information from passive environmental sensors to sense activities of daily living of older adults. The activity prediction system consists of recurrent neural networks to capture temporal dependencies. This work also carries out several experiments on collected and existing real datasets to evaluate the system's performance.


Subject(s)
COVID-19 , Self-Help Devices , Humans , Aged , Activities of Daily Living
4.
Pharm Nanotechnol ; 2022 06 15.
Article in English | MEDLINE | ID: mdl-35708092

ABSTRACT

Microbubbles are a new kind of delivery system that may be used to treat a variety of illnesses, including cancer. Microbubble is a non-invasive technology that uses microscopic gas-filled colloidal particle bubbles with a size range of less than 100 micrometres. This unique carrier has been used in a variety of applications in the last decade, ranging from basic targeting to ultrasound-mediated drug delivery. The oxygen in the microbubble lasts longer in the water. The drug release mechanism is highly regulated, since it releases the medication only in the appropriate areas, increasing the local impact while reducing drug toxicity. This carrier is exceptional in cancer medication delivery because of its sustained stability, encapsulation efficiency, and drug targeting. In this paper, we provide a comprehensive analysis of microbubble technology, including its manufacturing techniques and use in cancer medication delivery.

5.
Pharm Nanotechnol ; 2021 09 08.
Article in English | MEDLINE | ID: mdl-34496738

ABSTRACT

The article has been withdrawn at the request of the editor of the journal Pharmaceutical Nanotechnology due to incoherent content.Bentham Science apologizes to the readers of the journal for any inconvenience this may have caused.The Bentham Editorial Policy on Article Withdrawal can be found at https://benthamscience.com/editorial-policies-main.php. Bentham Science Disclaimer: It is a condition of publication that manuscripts submitted to this journal have not been published and will not be simultaneously submitted or published elsewhere. Furthermore, any data, illustration, structure or table that has been published elsewhere must be reported, and copyright permission for reproduction must be obtained. Plagiarism is strictly forbidden, and by submit-ting the article for publication the authors agree that the publishers have the legal right to take appropriate action against the authors, if plagiarism or fabricated information is discovered. By submitting a manuscript, the authors agree that the copyright of their article is transferred to the publishers if and when the article is accepted for publication.

6.
Chemistry ; 26(19): 4209-4213, 2020 Apr 01.
Article in English | MEDLINE | ID: mdl-31916272

ABSTRACT

The design of porous materials for the recognition of multiple hydrocarbons is highly desirable for the energy-efficient separation and recognition of chemical feedstock. Herein, three new iso-structural porous discrete metal-organic cages of formula {[Pd3 (NiPr)3 PO]4 (R-AN)6 } (R-AN=anilate linkers) for the selective recognition of substituted aromatic hydrocarbons are reported. The tetrahedral cages 1, 2, and 3 containing anilate, chloranilate, and bromanilate linkers exhibited selective encapsulation of mesitylene, o-xylene, and p-xylene, respectively, over other analogous aromatic hydrocarbons. These selective encapsulations were driven by the variations in the portal diameters present at each of these cages and their interactions with the hydrocarbon guests. These observations are supported by mass spectrometry, NMR studies, and theoretical binding-energy calculations.

7.
Org Lett ; 21(6): 1617-1621, 2019 03 15.
Article in English | MEDLINE | ID: mdl-30794417

ABSTRACT

An unprecedented skeletal rearrangement of 3-( tert-butylperoxy)indolin-2-one using a tin catalyst has been developed. This rearrangement is highly selective to afford a series of fluorophoric ( Z)-2-arylidene and alkylidene-2 H-benzo[ b][1,4]oxazin-3(4 H)-one derivatives in good to excellent yield. In contrast with Sn(OTf)2, the reaction of 3-( tert-butylperoxy)indolin-2-one derivatives with FeCl3 afforded the Hock fragmentation product via C-C bond cleavage.

8.
Inorg Chem ; 56(19): 11762-11767, 2017 Oct 02.
Article in English | MEDLINE | ID: mdl-28933539

ABSTRACT

A novel three-dimensional coordination network 1 in a new 4,5,6-connected topology (4,5,6T115) built from linear CuII4Cl3(H2O)2 clusters and tetrahedral tetrakis(3-pyridyl)vinylsilane ligands is reported. Utilizing a similar tetrahedral ligand, tetrakis(3-pyridyl)ethylsilane, a different framework 2 having CuII2Cl(H2O)2 clusters is obtained in tcs topology. The activated sample of 1 shows an excellent and reversible uptake of I2 in solid as well as in solution phases owing to the presence of uncoordinated chloride ions and electron rich vinylic groups in it. The I2 uptake studies on the anion-exchanged samples, of bromide, iodide, and nitrate ions, show a progressive decrease in the adsorption capacity with the sample containing uncoordinated Cl- ion showing a maximum uptake of 48.5% and the one with the NO3- ions exhibiting the lowest uptake of 24.0%. These observations suggest that the halide counterions interact better with I2 in comparison with nitrate ions and the better I2 uptake in the presence of Cl- ions over the other two halides is due to its smaller size that offers a larger surface area for adsorption. Also, both these compounds were shown to be useful catalysts for the solvent-free syntheses of bis(indolyl)methanes via Friedel-Crafts alkylation reaction.

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