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15 pages, 4082 KiB

Open AccessArticle

Human Activity Classification Using Multilayer Perceptron

by Ojan Majidzadeh Gorjani, Radek Byrtus, Jakub Dohnal, Petr Bilik, Jiri Koziorek and Radek Martinek

Sensors 2021, 21(18), 6207; https://doi.org/10.3390/s21186207 - 16 Sep 2021

Cited by 14 | Viewed by 3773

Abstract

The number of smart homes is rapidly increasing. Smart homes typically feature functions such as voice-activated functions, automation, monitoring, and tracking events. Besides comfort and convenience, the integration of smart home functionality with data processing methods can provide valuable information about the well-being [...] Read more.

The number of smart homes is rapidly increasing. Smart homes typically feature functions such as voice-activated functions, automation, monitoring, and tracking events. Besides comfort and convenience, the integration of smart home functionality with data processing methods can provide valuable information about the well-being of the smart home residence. This study is aimed at taking the data analysis within smart homes beyond occupancy monitoring and fall detection. This work uses a multilayer perceptron neural network to recognize multiple human activities from wrist- and ankle-worn devices. The developed models show very high recognition accuracy across all activity classes. The cross-validation results indicate accuracy levels above 98% across all models, and scoring evaluation methods only resulted in an average accuracy reduction of 10%. Full article

(This article belongs to the Topic Artificial Intelligence in Sensors)

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14 pages, 327 KiB

Open AccessArticle

Preparation of Candesartan and Atorvastatin Nanoparticles by Solvent Evaporation

by Eliska Vaculikova, Veronika Grunwaldova, Vladimir Kral, Jiri Dohnal and Josef Jampilek

Molecules 2012, 17(11), 13221-13234; https://doi.org/10.3390/molecules171113221 - 6 Nov 2012

Cited by 39 | Viewed by 7185

Abstract

The solubility, absorption and distribution of a drug are involved in the basic aspects of oral bioavailability Solubility is an essential characteristic and influences the efficiency of the drug. Over the last ten years, the number of poorly soluble drugs has steadily increased. [...] Read more.

The solubility, absorption and distribution of a drug are involved in the basic aspects of oral bioavailability Solubility is an essential characteristic and influences the efficiency of the drug. Over the last ten years, the number of poorly soluble drugs has steadily increased. One of the progressive ways for increasing oral bioavaibility is the technique of nanoparticle preparation, which allows many drugs to thus reach the intended site of action. Candesartan cilexetil and atorvastatin, belonging to class II of the biopharmaceutical classification system, were chosen as model active pharmaceutical ingredients in this study. Forty samples were prepared either by antisolvent precipitation/solvent evaporation method or by the emulsion/solvent evaporation technique with various commonly used surface-active excipients as nanoparticle stabilizers. All samples were analyzed by means of dynamic light scattering. The particle size of the determined 36 nanoparticle samples was to 574 nm, whereas 32 samples contained nanoparticles of less than 200 nm. Relationships between solvents and excipients used and their amount are discussed. Based on the results the investigated solvent evaporation methods can be used as an effective and an affordable technique for the preparation of nanoparticles. Full article

(This article belongs to the Section Medicinal Chemistry)

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12 pages, 220 KiB

Open AccessArticle

Primary Investigation of the Preparation of Nanoparticles by Precipitation

by Eliska Vaculikova, Veronika Grunwaldova, Vladimir Kral, Jiri Dohnal and Josef Jampilek

Molecules 2012, 17(9), 11067-11078; https://doi.org/10.3390/molecules170911067 - 13 Sep 2012

Cited by 19 | Viewed by 5262

Abstract

The absorption, distribution, biotransformation and excretion of a drug involve its transport across cell membranes. This process is essential and influenced by the characteristics of the drug, especially its molecular size and shape, solubility at the site of its absorption, relative lipid solubility, [...] Read more.

The absorption, distribution, biotransformation and excretion of a drug involve its transport across cell membranes. This process is essential and influenced by the characteristics of the drug, especially its molecular size and shape, solubility at the site of its absorption, relative lipid solubility, etc. One of the progressive ways for increasing bioavaibility is a nanoparticle preparation technique. Cholesterol, cholestenolone and pregnenolone acetate as model active pharmaceutical ingredients and some of the commonly used excipients as nanoparticle stabilizers were used in the investigated precipitation method that was modified and simplified and can be used as an effective and an affordable technique for the preparation of nanoparticles. All 120 prepared samples were analyzed by means of dynamic light scattering (Nanophox). The range of the particle size of the determined 100 nanoparticle samples was from 1 nm to 773 nm, whereas 82 samples contained nanoparticles of less than 200 nm. Relationships between solvents and used excipients and their amount are discussed. Full article

(This article belongs to the Section Medicinal Chemistry)

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21 pages, 978 KiB

Open AccessArticle

Crystallization Products of Risedronate with Carbohydrates and Their Substituted Derivatives

by Jiri Kos, Monika Pentakova, Zbynek Oktabec, Lukas Krejcik, Zuzana Mandelova, Pavla Harokova, Jana Hruskova, Tomas Pekarek, Ondrej Dammer, Marcela Tkadlecova, Jaroslav Havlicek, Jarmila Vinsova, Vladimir Kral, Jiri Dohnal and Josef Jampílek

Molecules 2011, 16(5), 3740-3760; https://doi.org/10.3390/molecules16053740 - 4 May 2011

Cited by 8 | Viewed by 8903

Abstract

The gastrointestinal absorption of bisphosphonates is in general only about 1%. To address this problem mixtures of risedronate monosodium salt with twelve varied sugar alcohols, furanoses, pyranoses and eight gluco-, manno- and galactopyranoside derivatives as counterions were designed in an effort to prepare [...] Read more.

The gastrointestinal absorption of bisphosphonates is in general only about 1%. To address this problem mixtures of risedronate monosodium salt with twelve varied sugar alcohols, furanoses, pyranoses and eight gluco-, manno- and galactopyranoside derivatives as counterions were designed in an effort to prepare co-crystals/new entities with improved intestinal absorption. Crystalline forms were generated by means of kinetically and/or thermodynamically controlled crystallization processes. One hundred and fifty-two prepared samples were screened by means of FT-NIR and FT-Raman spectroscopy. No co-crystal was prepared, but noteworthy results were obtained. A new solid phase of risedronate monosodium salt generated in the presence of phenyl-β-d-galactopyranoside under thermodynamically controlled crystallization conditions was found and also characterized using solid state NMR spectroscopy, X-ray powder diffraction and differential scanning calorimetry. This new polymorph was named as form P. Interactions between risedronate monosodium salt and both carbohydrates were confirmed by means of molecular dynamics simulation. In the present study the relationships between the chemical structures of the studied compounds required for crystalline form change are discussed. Full article

(This article belongs to the Special Issue ECSOC-14)

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15 pages, 412 KiB

Open AccessArticle

Preparation and Properties of New Co-Crystals of Ibandronate with Gluco- or Galactopyranoside Derivatives

by Zbynek Oktabec, Jiri Kos, Zuzana Mandelova, Lenka Havelkova, Tomas Pekarek, Anna Rezacova, Lukas Placek, Marcela Tkadlecova, Jaroslav Havlicek, Jiri Dohnal and Josef Jampílek

Molecules 2010, 15(12), 8973-8987; https://doi.org/10.3390/molecules15128973 - 8 Dec 2010

Cited by 10 | Viewed by 7638

Abstract

Mixtures of ibandronate monosodium salt with eleven gluco- and/or galacto-pyranoside derivatives as counterions were designed to prepare co-crystals with improved intestinal absorption. In general, gastrointestinal absorption of bisphosphonates after oral administration is approximately 1%. Co-crystals were generated by means of thermodynamically and/or kinetically [...] Read more.

Mixtures of ibandronate monosodium salt with eleven gluco- and/or galacto-pyranoside derivatives as counterions were designed to prepare co-crystals with improved intestinal absorption. In general, gastrointestinal absorption of bisphosphonates after oral administration is approximately 1%. Co-crystals were generated by means of thermodynamically and/or kinetically controlled crystallization processes. Seventy-seven prepared samples were analyzed by means of FT-NIR, FT-Raman spectrometry and solid state NMR spectroscopy. New entities of ibandronate monosodium salt with phenyl-β-d-galactopyranoside were found and characterized. The absorption of these potential new co-crystals was investigated by means of PAMPA experiments. In the present study the relationships between the chemical structures of the studied compounds required for co-crystal generation are discussed. Full article

(This article belongs to the Special Issue ECSOC-13)

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9 pages, 240 KiB

Open AccessCommunication

Synthesis and In Vitro Evaluation of N-(Bromobut-3-en-2-yl)-7-methoxy-1,2,3,4-tetrahydroacridin-9-amine as a Cholinesterase Inhibitor with Regard to Alzheimer's Disease Treatment

by Jan Korabecny, Kamil Musilek, Ondrej Holas, Eugenie Nepovimova, Daniel Jun, Filip Zemek, Veronika Opletalova, Jiri Patocka, Vlastimil Dohnal, Florian Nachon, Jana Hroudova, Zdenek Fisar and Kamil Kuca

Molecules 2010, 15(12), 8804-8812; https://doi.org/10.3390/molecules15128804 - 2 Dec 2010

Cited by 26 | Viewed by 8453

Abstract

A new tacrine based cholinesterase inhibitor, N-(bromobut-3-en-2-yl)-7-methoxy-1,2,3,4-tetrahydroacridin-9-amine (1), was designed and synthesized to interact with specific regions of human acetylcholinesterase and human butyrylcholinesterase. Its inhibitory ability towards cholinesterases was determined and compared to tacrine (THA) and 9-amino-7-methoxy-1,2,3,4-tetrahydroacridine (7-MEOTA). The assessment [...] Read more.

A new tacrine based cholinesterase inhibitor, N-(bromobut-3-en-2-yl)-7-methoxy-1,2,3,4-tetrahydroacridin-9-amine (1), was designed and synthesized to interact with specific regions of human acetylcholinesterase and human butyrylcholinesterase. Its inhibitory ability towards cholinesterases was determined and compared to tacrine (THA) and 9-amino-7-methoxy-1,2,3,4-tetrahydroacridine (7-MEOTA). The assessment of IC₅₀valuesrevealed 1 as a weak inhibitor of both tested enzymes. Full article

(This article belongs to the Section Medicinal Chemistry)

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15 pages, 277 KiB

Open AccessArticle

Synthesis, Antimycobacterial, Antifungal and Photosynthesis-Inhibiting Activity of Chlorinated N-phenylpyrazine-2-carboxamides ^†

by Martin Dolezal, Jan Zitko, Zdenek Osicka, Jiri Kunes, Marcela Vejsova, Vladimir Buchta, Jiri Dohnal, Josef Jampilek and Katarina Kralova

Molecules 2010, 15(12), 8567-8581; https://doi.org/10.3390/molecules15128567 - 26 Nov 2010

Cited by 44 | Viewed by 7920

Abstract

A series of sixteen pyrazinamide analogues with the -CONH- linker connecting the pyrazine and benzene rings was synthesized by the condensation of chlorides of substituted pyrazinecarboxylic acids with ring-substituted (chlorine) anilines. The prepared compounds were characterized and evaluated for their antimycobacterial and antifungal [...] Read more.

A series of sixteen pyrazinamide analogues with the -CONH- linker connecting the pyrazine and benzene rings was synthesized by the condensation of chlorides of substituted pyrazinecarboxylic acids with ring-substituted (chlorine) anilines. The prepared compounds were characterized and evaluated for their antimycobacterial and antifungal activity, and for their ability to inhibit photosynthetic electron transport (PET). 6-Chloro-N-(4-chlorophenyl)pyrazine-2-carboxamide manifested the highest activity against Mycobacterium tuberculosis strain H37Rv (65% inhibition at 6.25 μg/mL). The highest antifungal effect against Trichophyton mentagrophytes, the most susceptible fungal strain tested, was found for 6-chloro-5-tert-butyl-N-(3,4-dichlorophenyl)pyrazine-2-carboxamide (MIC = 62.5 μmol/L). 6-Chloro-5-tert-butyl-N-(4-chlorophenyl)pyrazine-2-carboxamide showed the highest PET inhibition in spinach chloroplasts (Spinacia oleracea L.) chloroplasts (IC₅₀ = 43.0 μmol/L). For all the compounds, the relationships between the lipophilicity and the chemical structure of the studied compounds as well as their structure-activity relationships are discussed. Full article

(This article belongs to the Special Issue ECSOC-12)

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20 pages, 194 KiB

Open AccessArticle

Investigating Biological Activity Spectrum for Novel Styrylquinazoline Analogues

by Josef Jampilek, Robert Musiol, Jacek Finster, Matus Pesko, James Carroll, Katarina Kralova, Marcela Vejsova, Jim O'Mahony, Aidan Coffey, Jiri Dohnal and Jaroslaw Polanski

Molecules 2009, 14(10), 4246-4265; https://doi.org/10.3390/molecules14104246 - 23 Oct 2009

Cited by 61 | Viewed by 12574

Abstract

In this study, series of ring-substituted 2-styrylquinazolin-4(3H)-one and 4-chloro-2-styrylquinazoline derivatives were prepared. The syntheses of the discussed compounds are presented. The compounds were analyzed by RP-HPLC to determine lipophilicity. They were tested for their inhibitory activity on photosynthetic electron transport (PET) [...] Read more.

In this study, series of ring-substituted 2-styrylquinazolin-4(3H)-one and 4-chloro-2-styrylquinazoline derivatives were prepared. The syntheses of the discussed compounds are presented. The compounds were analyzed by RP-HPLC to determine lipophilicity. They were tested for their inhibitory activity on photosynthetic electron transport (PET) in spinach (Spinacia oleracea L.) chloroplasts. Primary in vitro screening of the synthesized compounds was also performed against four mycobacterial strains and against eight fungal strains. Several compounds showed biological activity comparable with or higher than that of the standard isoniazid. It was found that the electronic properties of the R substituent, and not the total lipophilicity of the compound, were decisive for the photosynthesis-inhibiting activity of tested compounds. Full article

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16 pages, 270 KiB

Open AccessArticle

Rhodanineacetic Acid Derivatives as Potential Drugs: Preparation, Hydrophobic Properties and Antifungal Activity of (5-Arylalkylidene-4-oxo-2-thioxo-1,3-thiazolidin-3-yl)acetic Acids

by Jan Dolezel, Petra Hirsova, Veronika Opletalova, Jiri Dohnal, Vejsova Marcela, Jiri Kunes and Josef Jampilek

Molecules 2009, 14(10), 4197-4212; https://doi.org/10.3390/molecules14104197 - 20 Oct 2009

Cited by 51 | Viewed by 12367

Abstract

Some [(5Z)-(5-arylalkylidene-4-oxo-2-thioxo-1,3-thiazolidin-3-yl)]acetic acids were prepared as potential antifungal compounds. The general synthetic approach to all synthesized compounds is presented. Lipophilicity of all the discussed rhodanine-3-acetic acid derivatives was analyzed using a reversed phase high performance liquid chromatography (RP-HPLC) method. The procedure [...] Read more.

Some [(5Z)-(5-arylalkylidene-4-oxo-2-thioxo-1,3-thiazolidin-3-yl)]acetic acids were prepared as potential antifungal compounds. The general synthetic approach to all synthesized compounds is presented. Lipophilicity of all the discussed rhodanine-3-acetic acid derivatives was analyzed using a reversed phase high performance liquid chromatography (RP-HPLC) method. The procedure was performed under isocratic conditions with methanol as an organic modifier in the mobile phase using an end-capped non-polar C₁₈ stationary RP column. The RP-HPLC retention parameter log k (the logarithm of the capacity factor k) is compared with log P values calculated in silico. All compounds were evaluated for antifungal effects against selected fungal species. Most compounds exhibited no interesting activity, and only {(5Z)-[4-oxo-5-(pyridin-2- ylmethylidene)-2-thioxo-1,3-thiazolidin-3-yl]}acetic acid strongly inhibited the growth of Candida tropicalis 156, Candida krusei E 28, Candida glabrata 20/I and Trichosporon asahii 1188. Full article

(This article belongs to the Special Issue ECSOC-12)

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15 pages, 180 KiB

Open AccessArticle

Ring-substituted 4-Hydroxy-1H-quinolin-2-ones: Preparation and Biological Activity

by Josef Jampilek, Robert Musiol, Matus Pesko, Katarina Kralova, Marcela Vejsova, James Carroll, Aidan Coffey, Jacek Finster, Dominik Tabak, Halina Niedbala, Violetta Kozik, Jaroslaw Polanski, Jozef Csollei and Jiri Dohnal

Molecules 2009, 14(3), 1145-1159; https://doi.org/10.3390/molecules14031145 - 13 Mar 2009

Cited by 62 | Viewed by 14875

Abstract

In the study, a series of twelve ring-substituted 4-hydroxy-1H-quinolin-2-one derivatives were prepared. The procedures for synthesis of the compounds are presented. The compounds were analyzed using RP-HPLC to determine lipophilicity and tested for their photosynthesis-inhibiting activity using spinach (Spinacia oleracea [...] Read more.

In the study, a series of twelve ring-substituted 4-hydroxy-1H-quinolin-2-one derivatives were prepared. The procedures for synthesis of the compounds are presented. The compounds were analyzed using RP-HPLC to determine lipophilicity and tested for their photosynthesis-inhibiting activity using spinach (Spinacia oleracea L.) chloroplasts. All the synthesized compounds were also evaluated for antifungal activity using in vitro screening with eight fungal strains. For all the compounds, the relationships between the lipophilicity and the chemical structure of the studied compounds are discussed, as well as their structure-activity relationships (SAR). Full article

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