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1.
Proc Natl Acad Sci U S A ; 121(44): e2413511121, 2024 Oct 29.
Artículo en Inglés | MEDLINE | ID: mdl-39453748

RESUMEN

Current research on memory indicates that learning is most effective when it involves spaced retrieval practice of study materials. Here, we investigated whether the benefits of both retrieval practice and spacing can be further boosted when variability is introduced across practice sessions. Across six experiments, participants learned translations of foreign vocabulary, with foreign words embedded in contextual sentences hinting at the meaning of these words. These sentences were then either kept constant or varied from one learning cycle to another. Whenever repeated practice took the form of retrieval from long-term memory with contextual sentences serving as cues (with or without feedback after retrieval attempts), variable sentences led to better learning of the meanings of the embedded foreign words than constant sentences. The benefits of variable retrieval were observed both immediately after study and after a 24-h delay, and they were larger when retrieval practice was spaced rather than massed. However, these benefits were not appreciated by the learners who judged learning to be more effective with constant rather than variable cues. This metacognitive illusion, misaligning the effectiveness of learning and its appraisal by learners, was confirmed in the seventh experiment which focused on learning lecture content. Thus, while spaced retrieval practice employing variable cues clearly produces robust benefits for memory performance, such benefits may be severely underappreciated by the learners.


Asunto(s)
Aprendizaje , Recuerdo Mental , Humanos , Aprendizaje/fisiología , Recuerdo Mental/fisiología , Señales (Psicología) , Masculino , Femenino , Adulto , Memoria a Largo Plazo/fisiología , Adulto Joven , Vocabulario
2.
Mem Cognit ; 2024 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-39060851

RESUMEN

Errorful learning-asking questions and forcing responding even before the correct answers are presented for study-has recently been proposed as a way of maximizing the effectiveness of study. However, much support for the superiority of errorful learning over standard learning via reading comes from studies employing pairs of words as study materials, which remain of little educational relevance. Studies using materials affording richer semantic processing, such as trivia questions and their answers, have shown benefits of errorful learning only when the errorful learning condition is granted additional time for formulating guesses. In the present study, we systematically examined the role of timing when comparing errorful learning and reading strategies applied to study of trivia questions and their answers. In Experiments 1 and 2, we obtained evidence for the superiority of errorful learning over reading when additional time was given to formulate guesses, but this superiority was abolished when the overall time to study was equated between the two learning strategies. We further examined the role of answer familiarity in Experiment 3, showing that incorrect guessing produced no benefit for learning regardless of whether the to-be-learned concepts were familiar or not. In Experiments 4 and 5, no benefits of errorful learning emerged when participants were required to guess responses to two different questions that shared a common set of possible answers. We conclude that the benefits of errorful learning for trivia questions emerge only when guessing gives more time to process target questions.

3.
Mem Cognit ; 51(8): 1745-1760, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37084068

RESUMEN

We investigated whether people can discriminate between sources of information that are either credible or respond at random, based only on their own knowledge and the responses provided by these sources. In three experiments, participants were asked to judge the validity of trivia statements. Some statements were accompanied by true/false responses provided by either a credible source or a source whose responses were random. In Experiment 1, participants first saw a set of easy questions, which provided the basis for assessing the relative credibility of the sources, before responding to a set of difficult questions, where response borrowing was assessed. In Experiments 2 and 3, participants solved a test composed of difficult questions only, but only after studying the correct responses to all these questions. In Experiment 2, there was no delay between the study and test phases, whereas in Experiment 3, the delay was 24 hours. In all experiments, more participants explicitly identified the more credible source in the postexperimental questionnaire than misidentified the noninformative source as credible. However, differentiated response borrowing-borrowing more responses from the credible than the noninformative source-emerged only in Experiment 2. Therefore, people can often explicitly infer source credibility from the responses the sources provide. However, using these inferences to regulate response borrowing is relatively less likely and happens only under specific, favorable circumstances.


Asunto(s)
Conocimiento , Confianza , Humanos , Encuestas y Cuestionarios
4.
Mem Cognit ; 51(5): 1235-1248, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-36633821

RESUMEN

Trying to guess what the correct answer to a question might be can facilitate future learning of this answer when presented in the form of corrective feedback. One issue that determines the effectiveness of guessing as a learning strategy is the timing of the presentation of feedback: it can be presented either immediately after the guess, or after a delay. Whereas the timing of feedback is of little importance for complex materials such as trivia questions, previous research suggests that for simpler materials such as related word pairs guessing seems to benefit learning only when feedback is immediate. In order to test whether this always has to be the case, we conducted two experiments in which we increased the richness of study materials by superimposing the to-be-learned word pairs over unrelated context pictures. We then manipulated the match between contexts at study and at test (Experiment 1) and at the time of feedback delivery (Experiment 2). Contrary to previous studies showing no benefits of guessing with delayed feedback, our results show that learning related word pairs can benefit from guessing even when feedback is delayed. These benefits of guessing occur if participants are reminded via reinstated contexts of the guessing stage at the time of feedback delivery. Our results help constrain theories of guessing benefits and extend theories of reminding.


Asunto(s)
Retroalimentación Formativa , Lenguaje , Recuerdo Mental , Incertidumbre , Factores de Tiempo , Señales (Psicología) , Humanos , Adolescente , Adulto Joven , Adulto , Persona de Mediana Edad , Recuerdo Mental/fisiología
5.
Int J Mol Sci ; 24(9)2023 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-37176095

RESUMEN

One of the components of bee venom is melittin (M), which has strong lysing properties on membranes. M has high toxicity to cancer cells, but it also affects healthy cells, making it necessary to use methods for targeted delivery to ensure treatment. This research is a continuation of previous studies using graphene nanomaterials as M carriers to breast cancer cells. The studies described below are conducted on a more organized biological structure than what is found in vitro cells, namely, cancerous tumors grown on a chicken embryo chorioallantoic membrane. Caspase 3 and 8 levels are analyzed, and the level of oxidative stress markers and changes in protein expression for cytokines are examined. The results show that M complexes with nanomaterials reduce the level of oxidative stress more than M alone does, but the use of graphene (GN) as a carrier increases the level of DNA damage to a greater extent than the increase caused by M alone. An analysis of cytokine levels shows that the use of the M and GN complex increases the level of proteins responsible for inhibiting tumor progression to a greater extent than the increase occasioned by a complex with graphene oxide (GO). The results suggest that the use of GN as an M carrier may increase the toxic effect of M on structures located inside a cell.


Asunto(s)
Grafito , Neoplasias de la Mama Triple Negativas , Humanos , Animales , Embrión de Pollo , Meliteno/farmacología , Pollos , Grafito/farmacología , Grafito/química , Membrana Corioalantoides , Citocinas
6.
Mem Cognit ; 50(5): 1033-1047, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-34913140

RESUMEN

Guessing the meaning of a foreign word before being presented with the right answer benefits recognition performance for the translation compared to reading the full translation outright. However, guessing does not increase memory for the foreign-word-to-translation associations, which is crucial for language acquisition. In this study, we aimed to investigate whether this disadvantage of guessing for performance in cued-recall tests would be eliminated if a restudy phase was added. In Experiments 1-3, we consistently demonstrated that guessing resulted in lower cued-recall performance compared to reading, both before and after restudy. Even for items for which participants successfully recalled their initial guesses on the cued-recall test, accuracy levels did not exceed those from the reading condition. In Experiment 4, we aimed to generalize our findings concerning restudy to a different set of materials - weakly associated word pairs. Even though this time guessing led to better performance than reading, consistent with previous studies, this guessing benefit was not moderated by adding a restudy phase. Our results thus underscore the importance of the initial learning phase for future learning and retention, while undermining the usefulness of the learning-through-guessing strategy for acquiring foreign language vocabulary.


Asunto(s)
Lenguaje , Recuerdo Mental , Señales (Psicología) , Humanos , Aprendizaje , Reconocimiento en Psicología
7.
Int J Mol Sci ; 23(6)2022 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-35328834

RESUMEN

Thyroid hemiagenesis (THA) is an inborn absence of one thyroid lobe of largely unknown etiopathogenesis. The aim of the study was to reveal genetic factors responsible for thyroid maldevelopment in two siblings with THA. None of the family members presented with congenital heart defect. The samples were subjected to whole-exome sequencing (WES) (Illumina, TruSeq Exome Enrichment Kit, San Diego, CA 92121, USA). An ultra-rare variant c.839C>T (p.Pro280Leu) in NKX2-5 gene (NM_004387.4) was identified in both affected children and an unaffected father. In the mother, the variant was not present. This variant is reported in population databases with 0.0000655 MAF (GnomAD v3, dbSNP rs761596254). The affected amino acid position is moderately conserved (positive scores in PhyloP: 1.364 and phastCons: 0.398). Functional prediction algorithms showed deleterious impact (dbNSFP v4.1, FATHMM, SIFT) or benign (CADD, PolyPhen-2, Mutation Assessor). According to ACMG criteria, variant is classified as having uncertain clinical significance. For the first time, NKX2-5 gene variants were found in two siblings with THA, providing evidence for its potential contribution to the pathogenesis of this type of thyroid dysgenesis. The presence of the variant in an unaffected parent, carrier of p.Pro280Leu variant, suggests potential contribution of yet unidentified additional factors determining the final penetrance and expression.


Asunto(s)
Hermanos , Disgenesias Tiroideas , Niño , Exoma , Proteína Homeótica Nkx-2.5/genética , Humanos , Mutación , Disgenesias Tiroideas/genética , Disgenesias Tiroideas/patología
8.
Int J Mol Sci ; 23(9)2022 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-35562925

RESUMEN

Although Slavic populations account for over 4.5% of world inhabitants, no centralised, open-source reference database of genetic variation of any Slavic population exists to date. Such data are crucial for clinical genetics, biomedical research, as well as archeological and historical studies. The Polish population, which is homogenous and sedentary in its nature but influenced by many migrations of the past, is unique and could serve as a genetic reference for the Slavic nations. In this study, we analysed whole genomes of 1222 Poles to identify and genotype a wide spectrum of genomic variation, such as small and structural variants, runs of homozygosity, mitochondrial haplogroups, and de novo variants. Common variant analyses showed that the Polish cohort is highly homogenous and shares ancestry with other European populations. In rare variant analyses, we identified 32 autosomal-recessive genes with significantly different frequencies of pathogenic alleles in the Polish population as compared to the non-Finish Europeans, including C2, TGM5, NUP93, C19orf12, and PROP1. The allele frequencies for small and structural variants, calculated for 1076 unrelated individuals, are released publicly as The Thousand Polish Genomes database, and will contribute to the worldwide genomic resources available to researchers and clinicians.


Asunto(s)
Genética de Población , Genoma Humano , Alelos , Frecuencia de los Genes , Humanos , Proteínas Mitocondriales , Polonia
9.
Molecules ; 27(3)2022 Jan 27.
Artículo en Inglés | MEDLINE | ID: mdl-35164112

RESUMEN

Currently, the pharmaceutical industry is well-developed, and a large number of chemotherapeutics are being produced. These include antibacterial substances, which can be used in treating humans and animals suffering from bacterial infections, and as animal growth promoters in the agricultural industry. As a result of the excessive use of antibiotics and emerging resistance amongst bacteria, new antimicrobial drugs are needed. Due to the increasing trend of using natural, ecological, and safe products, there is a special need for novel phytocompounds. The compounds analysed in the present study include two triterpenoids ursolic acid (UA) and oleanolic acid (OA) and the flavonoid dihydromyricetin (DHM). All the compounds displayed antimicrobial activity against Gram-positive (Staphylococcus aureus ATCC 6538, Staphylococcus epidermidis ATCC 12228, and Listeria monocytogenes ATCC 19115) and Gram-negative bacteria (Escherichia coli ATCC 25922, Proteus hauseri ATCC 15442, and Campylobacter jejuni ATCC 33560) without adverse effects on eukaryotic cells. Both the triterpenoids showed the best antibacterial potential against the Gram-positive strains. They showed synergistic activity against all the tested microorganisms, and a bactericidal effect with the combination OA with UA against both Staphylococcus strains. In addition, the synergistic action of DHM, UA, and OA was reported for the first time in this study. Our results also showed that combination with triterpenoids enhanced the antimicrobial potential of DHM.


Asunto(s)
Antibacterianos/farmacología , Bacterias/crecimiento & desarrollo , Infecciones Bacterianas/tratamiento farmacológico , Flavonoides/farmacología , Triterpenos/farmacología , Sinergismo Farmacológico , Flavonoides/agonistas , Triterpenos/agonistas
10.
Molecules ; 27(7)2022 Mar 24.
Artículo en Inglés | MEDLINE | ID: mdl-35408479

RESUMEN

Quinoline is an N-heterocyclic compound commonly found in wastewater, especially that derived from coal processing, chemical, and pharmaceutical industries. In the present study, the microscopic fungus Curvularia lunata IM 4417, which is known to degrade various xenobiotics, was used. The aim of the research was to study the elimination of quinoline and its influence on fungal phospholipids, which are considered to be excellent indicators of environmental monitoring. Quinoline biodegradation products and phospholipid contents were analyzed using gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry. C. lunata IM 4417 degraded quinoline, which led to the formation of conjugates of glucose with hydroxylated derivatives of the compound. Toxicity tests (Artoxkit M and Microtox assay) indicated that the elimination of lower concentrations of quinoline was efficient and led to a reduction in sample toxicity. The presence of quinoline also significantly affected the profile of fatty acids and phospholipids. The addition of quinoline to a culture of C. lunata IM 4417 caused an increase in the content of phosphatidylcholine (PC) and a decrease in the amount of phosphatidylethanolamine (PE), two major structural lipids. Additionally, decreases in the contents of phosphatidylinositol (PI) and phosphatidylserine (PS), which are responsible for tolerance to toxic substances, cell viability, and signal transduction, were noted. Thus, it can be concluded that the presence of quinoline modifies the membrane composition, and this change may be an important indicator of the presence of N-heterocyclic compounds or other toxins in the environment.


Asunto(s)
Fosfolípidos , Quinolinas , Curvularia , Ácidos Grasos/análisis , Fosfolípidos/metabolismo , Quinolinas/farmacología
11.
Nucleic Acids Res ; 47(18): 9696-9707, 2019 10 10.
Artículo en Inglés | MEDLINE | ID: mdl-31400115

RESUMEN

Ubiquitous Structural Maintenance of Chromosomes (SMC) complexes use a proteinaceous ring-shaped architecture to organize and individualize chromosomes, thereby facilitating chromosome segregation. They utilize cycles of adenosine triphosphate (ATP) binding and hydrolysis to transport themselves rapidly with respect to DNA, a process requiring protein conformational changes and multiple DNA contact sites. By analysing changes in the architecture and stoichiometry of the Escherichia coli SMC complex, MukBEF, as a function of nucleotide binding to MukB and subsequent ATP hydrolysis, we demonstrate directly the formation of dimer of MukBEF dimer complexes, dependent on dimeric MukF kleisin. Using truncated and full length MukB, in combination with MukEF, we show that engagement of the MukB ATPase heads on nucleotide binding directs the formation of dimers of heads-engaged dimer complexes. Complex formation requires functional interactions between the C- and N-terminal domains of MukF with the MukB head and neck, respectively, and MukE, which organizes the complexes by stabilizing binding of MukB heads to MukF. In the absence of head engagement, a MukF dimer bound by MukE forms complexes containing only a dimer of MukB. Finally, we demonstrate that cells expressing MukBEF complexes in which MukF is monomeric are Muk-, with the complexes failing to associate with chromosomes.


Asunto(s)
Proteínas Cromosómicas no Histona/química , Proteínas de Escherichia coli/genética , Proteínas Represoras/genética , Proteínas Cromosómicas no Histona/genética , Cromosomas/química , Cromosomas/genética , Proteínas de Unión al ADN/química , Proteínas de Unión al ADN/genética , Escherichia coli/química , Escherichia coli/genética , Proteínas de Escherichia coli/química , Complejos Multiproteicos/química , Complejos Multiproteicos/genética , Unión Proteica , Proteínas Represoras/química
12.
Int J Mol Sci ; 22(9)2021 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-33921959

RESUMEN

Chloroxylenol (PCMX) is applied as a preservative and disinfectant in personal care products, currently recommended for use to inactivate the SARS-CoV-2 virus. Its intensive application leads to the release of PCMX into the environment, which can have a harmful impact on aquatic and soil biotas. The aim of this study was to assess the mechanism of chloroxylenol biodegradation by the fungal strains Cunninghamella elegans IM 1785/21GP and Trametes versicolor IM 373, and investigate the ecotoxicity of emerging by-products. The residues of PCMX and formed metabolites were analysed using GC-MS. The elimination of PCMX in the cultures of tested microorganisms was above 70%. Five fungal by-products were detected for the first time. Identified intermediates were performed by dechlorination, hydroxylation, and oxidation reactions catalysed by cytochrome P450 enzymes and laccase. A real-time quantitative PCR analysis confirmed an increase in CYP450 genes expression in C. elegans cells. In the case of T. versicolor, spectrophotometric measurement of the oxidation of 2,20-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) showed a significant rise in laccase activity during PCMX elimination. Furthermore, with the use of bioindicators from different ecosystems (Daphtoxkit F and Phytotoxkit), it was revealed that the biodegradation process of PCMX had a detoxifying nature.


Asunto(s)
Cunninghamella/metabolismo , Trametes/metabolismo , Xilenos/metabolismo , Animales , Sistema Enzimático del Citocromo P-450/genética , Sistema Enzimático del Citocromo P-450/metabolismo , Daphnia/efectos de los fármacos , Daphnia/fisiología , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Cromatografía de Gases y Espectrometría de Masas , Regulación de la Expresión Génica , Lacasa/metabolismo , Oxidación-Reducción , Pruebas de Toxicidad , Xilenos/análisis , Xilenos/farmacología
13.
Int J Mol Sci ; 22(23)2021 Nov 26.
Artículo en Inglés | MEDLINE | ID: mdl-34884610

RESUMEN

One of the greatest threats to human and animal health is posed by infections caused by drug-resistant bacterial strains. Therefore, newly synthesised substances are tested for their antimicrobial activity. Carbazole derivatives seem to be promising antibacterial agents. This study aimed at investigating the toxicity and activity of newly synthesised, functionalised carbazole derivative 2 (4-(4-(benzylamino)butoxy)-9H-carbazole) against various microorganisms. Its antimicrobial potential against Gram-positive and Gram-negative bacteria, yeast, and filamentous fungi was examined according to CLSI (Clinical and Laboratory Standards Institute) standards. The tested compound was found to efficiently inhibit the growth of Gram-positive strains. The addition of carbazole derivative 2 at the concentration of 30 µg/mL caused inhibition of bacterial growth by over 95%. Moreover, about 50 and 45% limitation of Pseudomonas aeruginosa and Aspergillus flavus growth was observed in the samples incubated with the addition of 20 and 60 µg/mL of the compound, respectively. Its addition to the microbial cultures caused an increase in the permeability of the cellular membrane. Slight haemolysis of red blood cells was observed after 24-h treatment with carbazole derivative 2. On the other hand, human fibroblasts were found to be more sensitive to its effects. The activity of the tested compound indicates a possibility of its further modification in order to obtain effective drugs, especially against drug-resistant staphylococci.


Asunto(s)
Antiinfecciosos/farmacología , Bacterias/efectos de los fármacos , Carbazoles/química , Fibroblastos/efectos de los fármacos , Hongos/efectos de los fármacos , Levaduras/efectos de los fármacos , Antiinfecciosos/química , Humanos
14.
Int J Mol Sci ; 22(4)2021 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-33561977

RESUMEN

Zinc compounds have a number of beneficial properties for the skin, including antimicrobial, sebostatic and demulcent activities. The aim of the study was to develop new anti-acne preparations containing zinc-amino acid complexes as active ingredients. Firstly, the cytotoxicity of the zinc complexes was evaluated against human skin fibroblasts (1BR.3.N cell line) and human epidermal keratinocyte cell lines, and their antimicrobial activity was determined against Cutibacterium acnes. Then, zinc complexes of glycine and histidine were selected to create original gel formulations. The stability (by measuring pH, density and viscosity), microbiological purity (referring to PN-EN ISO standards) and efficacy of the preservative system (according to Ph. Eur. 10 methodology) for the preparations were evaluated. Skin tolerance was determined in a group of 25 healthy volunteers by the patch test. The preparations containing zinc(II) complexes with glycine and histidine as active substances can be topically used in the treatment of acne skin due to their high antibacterial activity against C. acnes and low cytotoxicity for the skin cells. Dermatological recipes have been appropriately composed; no irritation or allergy was observed, and the preparations showed high microbiological purity and physicochemical stability.


Asunto(s)
Acné Vulgar/tratamiento farmacológico , Antibacterianos/farmacología , Glicina/farmacología , Histidina/farmacología , Propionibacteriaceae/efectos de los fármacos , Compuestos de Zinc/farmacología , Acné Vulgar/microbiología , Línea Celular , Glicina/química , Histidina/química , Humanos , Queratinocitos/efectos de los fármacos , Propionibacteriaceae/crecimiento & desarrollo , Piel/efectos de los fármacos , Piel/microbiología , Piel/patología , Crema para la Piel , Zinc/química , Compuestos de Zinc/química
15.
Int J Mol Sci ; 22(11)2021 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-34072512

RESUMEN

Synthetic materials commonly used in the packaging industry generate a considerable amount of waste each year. Chitosan is a promising feedstock for the production of functional biomaterials. From a biological point of view, chitosan is very attractive for food packaging. The purposes of this study were to evaluate the antibacterial activity of a set of chitosan-metal oxide films and different chitosan-modified graphene (oxide) films against two foodborne pathogens: Campylobacter jejuni ATCC 33560 and Listeria monocytogenes 19115. Moreover, we wanted to check whether the incorporation of antimicrobial constituents such as TiO2, ZnO, Fe2O3, Ag, and graphene oxide (GO) into the polymer matrices can improve the antibacterial properties of these nanocomposite films. Finally, this research helps elucidate the interactions of these materials with eukaryotic cells. All chitosan-metal oxide films and chitosan-modified graphene (oxide) films displayed improved antibacterial (C. jejuni ATCC 33560 and L. monocytogenes 19115) properties compared to native chitosan films. The CS-ZnO films had excellent antibacterial activity towards L. monocytogenes (90% growth inhibition). Moreover, graphene-based chitosan films caused high inhibition of both tested strains. Chitosan films with graphene (GO, GOP, GOP-HMDS, rGO, GO-HMDS, rGOP), titanium dioxide (CS-TiO2 20:1a, CS-TiO2 20:1b, CS-TiO2 2:1, CS-TiO2 1:1a, CS-TiO2 1:1b) and zinc oxide (CS-ZnO 20:1a, CS-ZnO 20:1b) may be considered as a safe, non-cytotoxic packaging materials in the future.


Asunto(s)
Antiinfecciosos/química , Antiinfecciosos/farmacología , Materiales Biocompatibles , Quitosano , Microbiología de Alimentos , Embalaje de Alimentos , Membranas Artificiales , Antibacterianos/química , Antibacterianos/farmacología , Membrana Externa Bacteriana/efectos de los fármacos , Permeabilidad de la Membrana Celular/efectos de los fármacos , Quitosano/química , Metales/química , Polímeros
16.
Molecules ; 25(4)2020 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-32093383

RESUMEN

The multifunctional profile of Zn2+ has influenced its great popularity in various pharmaceutical, food, and cosmetic products. Despite the use of different inorganic and organic zinc derivatives, the search for new zinc-containing compounds with a safer skin profile still remains an open issue. The present paper describes the synthesis, structural characterization, and antibacterial activity of zinc(II) complexes with proteinogenic amino acids as potential candidates for dermatological treatments. The obtained complexes are of the general formula [Zn(AA)2], where AA represents an amino acid (L-Glu, Gly, L-His, L-Pro, L-Met, and L-Trp). Their synthesis was designed in such a way that the final bis(aminoacidate) zinc(II) complexes did not contain any counter-ions such as Cl-, NO3-, or SO42- that can cause some skin irritations. The chemical structure and composition of the compounds were identified by 1H NMR spectroscopy and elemental analysis, and four were also characterized by single-crystal X-ray diffraction. The Hirshfeld surface analysis for the Zn2+ metallic center helped to determine its coordination number and geometry for each complex. Finally, the antibacterial properties of the complexes were determined with respect to three Gram-positive strains, viz. Staphylococcus aureus ATCC 6538, Staphylococcus epidermidis ATCC 12228, and Streptococcus pyogenes ATCC 19615, and two Gram-negative bacteria, viz. Escherichia coli ATCC 25992 and Pseudomonas aeruginosa ATCC 27853, and were compared with the activity of zinc 2-pirrolidone 5-carboxylate (ZnPCA), commonly applied in dermatology. It was found that the Zn(II) complexes with methionine and glycine exhibited a higher antibacterial activity than the tested standard, and the antimicrobial properties of complex with Trp were satisfactory. The results of the antimicrobial activity examination allow us to postulate that the obtained zinc complexes might become new active substances for use in dermatological products.


Asunto(s)
Aminoácidos/química , Antibacterianos , Bacterias/crecimiento & desarrollo , Complejos de Coordinación , Zinc/química , Antibacterianos/síntesis química , Antibacterianos/química , Antibacterianos/farmacología , Complejos de Coordinación/síntesis química , Complejos de Coordinación/química , Complejos de Coordinación/farmacología , Pruebas de Sensibilidad Microbiana , Estructura Molecular
17.
Molecules ; 24(22)2019 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-31739388

RESUMEN

Staphylococcus aureus infections are common and difficult to treat. The increasing number of drug-resistant staphylococcal infections has created the need to develop new strategies for the treatment of these infections. The synergistic antimicrobial activity of different pharmaceuticals seems to be an interesting alternative. The aim of this study was to assess the synergistic activity of ciprofloxacin and carvedilol against S. aureus strains. The antibacterial potential of ciprofloxacin and carvedilol was evaluated according to the CLSI guidelines. The calcium content in S. aureus cells was measured using flow cytometry and atomic absorption spectroscopy. Moreover, confocal and scanning electron microscopy were used to determine the mechanism of antibacterial synergy of ciprofloxacin and carvedilol. The antibacterial effect of ciprofloxacin was higher in the presence of carvedilol than in S. aureus cultures containing the antibiotic only. A significant increase in S. aureus membrane permeability was also observed. The simultaneous administration of the tested compounds caused damage to S. aureus cells visualized by SEM. Enhancement of the antimicrobial action of ciprofloxacin by carvedilol was correlated with an increase in free calcium content in S. aureus cells, morphological changes to the cells, and a reduction in the ability to form bacterial aggregates.


Asunto(s)
Antibacterianos/farmacología , Carvedilol/farmacología , Ciprofloxacina/farmacología , Staphylococcus aureus/efectos de los fármacos , Pruebas de Sensibilidad Microbiana
18.
Neuro Endocrinol Lett ; 37(1): 53-8, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26994386

RESUMEN

OBJECTIVE: Pregnancy is usually associated with significant regression in genito-genital intercourse frequency, sexual desire and satisfaction. The aim of the study was to determine women's sexual habits during the third trimester of gestation and to compare their sexual activity before the current pregnancy and during previous pregnancies in case of multiparas. MATERIAL AND METHODS: The study material consisted of women in the third trimester of pregnancy, recruited from the Outpatient Clinic of the 1st Department of Obstetrics and Gynecology, Medical University of Warsaw between January 2013 and February 2014, who filled out a self-prepared questionnaire. The questionnaire consisted of three parts: demographic data, sexual activity prior to current pregnancy and during gestation, including sexual positions and sources of knowledge regarding the subject. The survey involved 25 questions and was distributed among 220 patients, out of which 165 were returned and 149 properly filled out and analyzed. RESULTS: The average age of the respondents was 29.6 ± 4.85 years; the majority (78.8%) were in an uncomplicated pregnancy. The decrease in sexual activity was evident in all age groups--the majority usually had sex 1 to 3 times a month in contrast to 1-2 times a week prior to conceiving. Sexual activity decreased significantly with increasing age. The main reasons for abandoning sexual activity included: decreased libido (35.5%), the doctor's suggestion (29%) and fears concerning child's health (29%). During pregnancy the frequency of vaginal intercourse significantly decreased (100% prior to vs. 86.6% during pregnancy; p < 0.001); as did oral sex (44.3% vs. 29.5%; p = 0.043) and anal sex (12% vs. 5.4%; p = 0.02). 54% of the respondents declared reduced satisfaction with sexual life during pregnancy in comparison with the previous period; almost half (43.5%) felt less attractive while pregnant. The same claim was related to libido--it decreased in 58.8% of respondents. Multiparas tended to have sexual intercourses less often in consecutive pregnancies (41.2%) or with an equal frequency (35.3%). The main source of knowledge about sexual life during pregnancy listed by women included internet and other media (63.5%), while medical staff was mentioned by 30%. CONCLUSIONS: Sexual activity decreases during gestation, however, it often result from an increased fear for the child and lack of possibilities to confront and broaden the knowledge on this subject. The role of medical staff in consulting sexual activity problems is insufficient.


Asunto(s)
Tercer Trimestre del Embarazo , Conducta Sexual , Adolescente , Adulto , Miedo , Femenino , Conocimientos, Actitudes y Práctica en Salud , Humanos , Edad Materna , Paridad , Postura , Embarazo , Tercer Trimestre del Embarazo/fisiología , Tercer Trimestre del Embarazo/psicología , Conducta Sexual/fisiología , Conducta Sexual/psicología , Encuestas y Cuestionarios , Adulto Joven
19.
Mem Cognit ; 43(8): 1168-79, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26111879

RESUMEN

The underconfidence-with-practice (UWP) effect is a common finding in calibration studies concerned with judgments of learning (JOLs) elicited on a percentage scale. The UWP pattern is present when, in a procedure consisting of multiple study-test cycles, the mean scale JOLs underestimate the mean recall performance on Cycle 2 and beyond. Although this pattern is present both for items recalled and unrecalled on the preceding cycle, to date research has concentrated mostly on the sources of UWP for the latter type of items. In the present study, we aimed to bridge this gap. In three experiments, we examined calibration on the third of three cycles. The results of Experiment 1 demonstrated the typical pattern of higher recall and scale JOLs for previously recalled items than for unrecalled ones. More importantly, they also revealed that even though the UWP effect was found for items previously recalled both once and twice, its magnitude was greater for the former class of items. Experiments 2 and 3, which employed a binary betting task and a binary 0 %/100 % JOL task, respectively, demonstrated that people can accurately predict future recall for previously recalled items with binary decisions. In both experiments, the UWP effect was absent for both items recalled once and twice. We suggest that the sensitivity of scale JOLs, but not binary judgments, to the number of previous recall successes strengthens the claim of Hanczakowski, Zawadzka, Pasek, and Higham (Journal of Memory and Language 69:429-444, 2013) that scale JOLs reflect confidence in, rather than the subjective probability of, future recall.


Asunto(s)
Aprendizaje/fisiología , Recuerdo Mental/fisiología , Metacognición/fisiología , Práctica Psicológica , Adulto , Calibración , Humanos , Juicio , Adulto Joven
20.
Mem Cognit ; 43(5): 788-97, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25586819

RESUMEN

The context reinstatement effect refers to the enhanced memory performance found when the context information paired with a target item at study is re-presented at test. Here we investigated the consequences of the way that context information is processed in such a setting that gives rise to its beneficial effect on item recognition memory. Specifically, we assessed whether reinstating context in a recognition test facilitates subsequent memory for this context, beyond the facilitation conferred by presentation of the same context with a different study item. Reinstating the study context at test led to better accuracy in two-alternative forced choice recognition for target faces than did re-pairing those faces with another context encountered during the study phase. The advantage for reinstated over re-paired conditions occurred for both within-subjects (Exp. 1) and between-subjects (Exp. 2) manipulations. Critically, in a subsequent recognition test for the contexts themselves, contexts that had previously served in the reinstated condition were recognized better than contexts that had previously served in the re-paired context condition. This constitutes the first demonstration of continuous effects of context reinstatement on memory for context.


Asunto(s)
Reconocimiento Facial/fisiología , Recuerdo Mental/fisiología , Reconocimiento en Psicología/fisiología , Adulto , Humanos , Adulto Joven
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