Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 126
Filtrar
1.
Br J Soc Psychol ; 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38887105

RESUMO

Recent research suggests that stereotypes are not only applied to social groups but also to the physical spaces that social groups inhabit. We present three experiments investigating space-focused stereotype content and valence regarding immigrant and non-immigrant neighbourhoods. In Study 1a (N = 198), a pre-registered online experiment, we observed that participants associate more negative characteristics with immigrant neighbourhoods than with middle-class neighbourhoods. Whereas they imagined immigrant neighbourhoods as crime-ridden, dirty and dangerous, they imagined middle-class neighbourhoods to be quiet, clean and safe. Furthermore, whereas stereotype valence regarding immigrant neighbourhoods was negative, stereotype valence regarding middle-class neighbourhoods was positive, suggesting large effects. These results were replicated in Study 1b (N = 274), examining stereotypes of immigrant versus majority-German neighbourhoods. In Study 2 (N = 209), a pre-registered online experiment, we observed that space-focused stereotypes were more negative when cultural stereotypes rather than personal beliefs were assessed. Exploratory analyses revealed that, compared with majority-German neighbourhoods, participants imagined immigrant neighbourhoods to be lower in socioeconomic status and also reported feeling less psychologically connected to these neighbourhoods, regardless of whether space-focused stereotypes were personally endorsed or not. Lastly, a mega-analysis across studies suggested that effects of stereotypes of immigrant in comparison to non-immigrant places were very large (ds = 1.70). Together, the present findings indicate that mere differences in descriptions of places with reference to their demographic composition are sufficient to elicit large differences in associated stereotype content and valence.

2.
Wilderness Environ Med ; 35(2): 129-137, 2024 06.
Artigo em Inglês | MEDLINE | ID: mdl-38384121

RESUMO

INTRODUCTION: While the use of camping stoves in poorly ventilated areas is discouraged, the need to address dehydration challenges in harsh arctic conditions has led to their unconventional use inside snow caves for snow melting, subjecting occupants to unknown carbon monoxide (CO) levels. This study, located at sea level in northeastern Greenland, aimed to assess CO levels and dynamics during short cooking sessions in newly constructed emergency snow caves. METHODS: In 5 snow caves, constructed according to the same design principles by 4 different individuals, a single MSR Whisperlite multifuel burner, primed with ethanol and burning white gas, was used to melt snow. CO concentrations were monitored every minute until all the snow in a 5-L pot was converted to water and CO levels returned to below 10 ppm. RESULTS: A total of 16 experiments conducted showed that the priming phase generated the highest CO peaks, with a maximum of 120 ppm. Time-weighted averages ranged from 14 ppm to 67 ppm, with trial durations of 15 to 21 min. A single trial with a dirty burner resulted in up to a 10-fold increase in CO levels. CONCLUSIONS: While single, short cooking sessions of less than 10 min burn time in newly constructed snow caves may be tolerated under specific conditions, the study highlighted substantial variation between caves and the importance of using clean burners, emphasizing the need for further research to gain a comprehensive understanding of CO exposure dynamics in snow caves.


Assuntos
Monóxido de Carbono , Culinária , Neve , Humanos , Monóxido de Carbono/análise , Culinária/métodos , Groenlândia , Poluição do Ar em Ambientes Fechados/análise
3.
Chem Senses ; 482023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-37956399

RESUMO

Masking unpleasant odors with pleasant-smelling odorants has a long history and is utilized in various industries, including perfumery and consumer products. However, the effectiveness of odor masking is idiosyncratic and temporary. In this study, we employed Sniff olfactometry (SO) to investigate the psychophysics of masking using brief 70 ms stimulations with mixtures of the mal-odorant iso-valeric acid (IVA) and different masking agents. IVA is a component of human sweat that can overpower its smell and is often associated with unpleasant descriptors such as "gym locker," "smelly feet," "dirty clothes," and so on. Traditionally, high concentrations of pleasant-smelling odorants are used to mitigate the unpleasantness of IVA in situations involving clothing or environments contaminated with IVA. To examine the masking effects of sub-threshold levels of various masking agents (neohivernal, geraniol, florhydral, decanal, iso-longifolanone, methyl iso-eugenol, and s-limonene) on IVA, we conducted experiments using SO to measure the probability of recognizing IVA after 70 ms stimulations with headspaces containing mixtures of super-threshold concentrations of IVA and sub-threshold concentrations of IVA suppressors. The study involved nine subjects, and on average, a single masking agent was found to decrease IVA recognition probability by 14-72%. Moreover, a sub-threshold odor mixture consisting of 6 masking agents demonstrated a substantial decrease in IVA recognition, with a reduction of 96%.


Assuntos
Odorantes , Olfato , Humanos , Ácidos Pentanoicos , Olfatometria
4.
Neuroscience ; 535: 168-183, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37944582

RESUMO

Comorbidity of post-traumatic stress disorder (PTSD) and alcohol use disorder (AUD) worsens the prognosis for each of these individual disorders. The current study aimed to identify neurocircuits potentially involved in regulation of PTSD-AUD comorbidity by mapping expression of c-Fos in male and female C57BL/6J mice following repeated predator stress (PS), modeled by exposure to dirty rat bedding. In experiment 1, the levels of c-Fos in the paraventricular nucleus of the hypothalamus (PVH) and the nucleus accumbens shell were higher after the second PS vs the first PS, indicating a sensitized response to this stressor. Additional brain regions showed varied sex-dependent and independent regulation by the two consecutive PS exposures. In experiment 2, mice that increased voluntary alcohol consumption following four exposures to PS (Sensitive subgroup) showed higher c-Fos induction in the PVH, piriform cortex and ventromedial hypothalamus than mice that decreased consumption following these exposures (Resilient subgroup). In contrast to these brain regions, c-Fos was higher in the anterior olfactory nucleus of Resilient vs Sensitive mice. Taken together, these data demonstrate that repeated PS exposure and voluntary alcohol consumption increase neuronal activity across neurocircuits in which specific components depend on the vulnerability of individual mice to these stressors. Increased PVH activity observed across both experiments suggests this brain area as a potential mediator of PS-induced increases in alcohol consumption. Future investigations of specific neuronal populations within the PVH activated by PS, and manipulation of these specific neuronal populations, could improve our understanding of the mechanisms leading to PTSD-AUD comorbidity.


Assuntos
Consumo de Bebidas Alcoólicas , Encéfalo , Ratos , Camundongos , Masculino , Feminino , Animais , Camundongos Endogâmicos C57BL , Encéfalo/metabolismo , Núcleo Accumbens/metabolismo , Proteínas Proto-Oncogênicas c-fos/metabolismo , Fenótipo
5.
EPJ Quantum Technol ; 10(1): 41, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37810533

RESUMO

High-impedance resonators are a promising contender for realizing long-distance entangling gates between spin qubits. Often, the fabrication of spin qubits relies on the use of gate dielectrics which are detrimental to the quality of the resonator. Here, we investigate loss mechanisms of high-impedance NbTiN resonators in the vicinity of thermally grown SiO2 and Al2O3 fabricated by atomic layer deposition. We benchmark the resonator performance in elevated magnetic fields and at elevated temperatures and find that the internal quality factors are limited by the coupling between the resonator and two-level systems of the employed oxides. Nonetheless, the internal quality factors of high-impedance resonators exceed 103 in all investigated oxide configurations which implies that the dielectric configuration would not limit the performance of resonators integrated in a spin-qubit device. Because these oxides are commonly used for spin qubit device fabrication, our results allow for straightforward integration of high-impedance resonators into spin-based quantum processors. Hence, these experiments pave the way for large-scale, spin-based quantum computers.

6.
J Environ Radioact ; 270: 107296, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37734236

RESUMO

Explosive Radiological Dispersal Devices (RDD) - aka dirty bombs - are seen as a credible method to carry out a radiological terror attack. After exploding a radioactive source, the radionuclide-laden plume will be blown downwind of ground zero, with particles falling out and potentially depositing on people caught in and under the cloud. Some of these people may not show any sign of radiation sickness and therefore not realize they have been contaminated and may take the radioactive particulate with them on their daily activities, thus spreading the radioactive particulate outside the initially contaminated area. This paper reviews the scientific literature to better understand the rate at which particulate deposits on and is removed from the different "surfaces" of a person, i.e., hair, skin, and clothing. Prior research indicates that: 1) particle deposition is usually higher on skin than on hair and clothing; 2) particle deposition is greater for a person with higher skin moisture, 3) stronger wind increases the deposition flux onto a person, and 4) the fraction of particulate deposited on the hair, skin, and clothing respectively depends on the length of the hair, assuming all the hair surface is available for deposition. The studies taken into consideration show that the largest uncertainty in particulate deposition onto a person is due to clothing type because of the different possible weave arrangements and tightness which translate into differences in actual surface area and surface roughness. A factor of 2-to-20 variation in deposition rate was found. Removal of the particulate from the contaminated person may be due to wind, a person's movement, and/or contact transfer, i.e., by touching a different clean surface. Experiments show that the majority of the particulate is resuspended within 2-6 h mostly depending on the intensity of physical activity. The largest uncertainty in particulate removal from skin depends on the skin moisture, transfer rate of single-contact, and how many objects/people a person touches per hour. No data for hair were found for particle removal and resuspension. The studies considered did not utilize radionuclides directly; however, data on adhesion of radioactive vs. their non-radioactive counterpart have shown that the uncertainty due to the radioactivity of the particles is lower than that due to other factors. An idealized scenario involving a single building in the path of the cloud showed the impact of building-influenced flow on the cloud transport path and mixing, which affects the radiological dose the downwind population is exposed to and consequently the health effects.


Assuntos
Monitoramento de Radiação , Radioatividade , Humanos , Monitoramento de Radiação/métodos , Poeira , Cabelo , Vestuário
7.
Radiat Prot Dosimetry ; 199(8-9): 1012-1020, 2023 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-37225232

RESUMO

Experiments simulating radioactive dirty bomb explosions in an urban area were performed at the National Institute of NBC Protection (SUJCHBO v.v.i.), Czech Republic. A solution containing 99mTc radionuclide was dispersed by an explosion on an open-air model of a square covered with filters. Subsequently, spectra of gamma rays originating in contaminated filters were measured by a hand-held NaI(Tl) spectrometer and laboratory HPGe spectrometers. The ambient dose equivalent rate at measuring vessels was set as well. Self-made standards had been prepared by dripping a defined amount of 99mTc solution uniformly on the filters to set the 99mTc surface contamination of measured samples. The urban area model's radioactive contamination map was set using previously determined filters' locations. The defined amount of 99mTc solution was dripped non-homogenously on some filters to estimate the impact of non-homogenous filters' coverage by radioactive aerosol' particles.


Assuntos
Armas Nucleares , Monitoramento de Radiação , Explosões , Academias e Institutos , República Tcheca
8.
J Environ Radioact ; 263: 107166, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37059048

RESUMO

Dirty bombs are considered one of the easiest forms of radiological terrorism, a form of terrorism based on the deliberate use of radiological material to cause adverse effects in a target population. One U.S. Government official has even described a dirty bomb attack as "all but inevitable". While people in the vicinity of the blast may experience acute radiation effects, people downwind may unknowingly be contaminated by the radioactive airborne particulate and face increased long-term cancer risk. The likelihood of increased cancer risk depends on the radionuclide used and its specific activity, its aerosolization potential, the particle sizes generated in the blast, and where a person is with respect to the detonation. Different studies have reported that plausible radionuclides for dirty bomb include 60Co, 90Sr, 137Cs, 192Ir, 241Am based on their availability in commercial sources as well as safeguards, the amount needed for adverse health effects, previous mishandling of radionuclides and malicious uses. In order to have increased long-term cancer risk, the radionuclide would have to deposit inside the body by entering the respiratory tract and then possibly migrate to other organs or bones (ground shine is not considered in this paper because areas affected by the event will likely become inaccessible). This implies that the particles will have to be smaller than 10 µm to be inhaled. Experiments involving the detonation of dirty bombs have shown that particles or droplets smaller than 10 µm are generated, independently from the initial radionuclide or its state (e.g., powder, solution). Atmospheric tests have shown that in unobstructed terrain, the radionuclide laden cloud can travel kilometers downwind even for relatively small amounts of explosives. Buildings in the path of the cloud can change the dose rate. For instance, in one experiment with a single building, the dose rate was 1-2 orders of magnitude lower behind the obstacle compared to its front face. For people walking around, the amount of particulate deposited on them and inhaled will depend on their path relative to the cloud, resulting in the counterintuitive result that the closer people may actually not be the ones more at risk because they could simply miss the bulk of the cloud in their wandering. In summary, the long-term cancer risk for people caught in a dirty bomb cloud away from the detonation requires considering where and when the people are, which radionuclide was used, and the layout of the obstacles (e.g., buildings, vegetation) in the path of the cloud.


Assuntos
Neoplasias , Armas Nucleares , Lesões por Radiação , Monitoramento de Radiação , Terrorismo , Humanos , Monitoramento de Radiação/métodos , Neoplasias/complicações
9.
Life (Basel) ; 13(2)2023 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-36836628

RESUMO

The standard approach to exploring prebiotic chemistry is to use a small number of highly purified reactants and to attempt to optimize the conditions required to produce a particular end product. However, purified reactants do not exist in nature. We have previously proposed that what drives prebiotic evolution are complex chemical ecologies. Therefore, we have begun to explore what happens if one substitutes "sea water", with its complex mix of minerals and salts, for distilled water in the classic Miller experiment. We have also adapted the apparatus to permit it to be regassed at regular intervals so as to maintain a relatively constant supply of methane, hydrogen, and ammonia. The "sea water" used in the experiments was created from Mediterranean Sea salt with the addition of calcium phosphate and magnesium sulfate. Tests included several types of mass spectrometry, an ATP-monitoring device capable of measuring femtomoles of ATP, and a high-sensitivity cAMP enzyme-linked immunoadsorption assay. As expected, amino acids appeared within a few days of the start of the experiment and accumulated thereafter. Sugars, including glucose and ribose, followed as did long-chain fatty acids (up to C20). At three-to-five weeks after starting the experiment, ATP was repeatedly detected. Thus, we have shown that it is possible to produce a "one-pot synthesis" of most of the key chemical prerequisites for living systems within weeks by mimicking more closely the complexity of real-world chemical ecologies.

10.
Pharmacol Res ; 188: 106676, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36693599

RESUMO

Age-related gastrointestinal decline contributes to whole-organism frailty and mortality. Genistein is known to have beneficial effects on age-related diseases, but its precise role in homeostasis of the aging gut remains to be elucidated. Here, wild-type aging mice and Zmpste24-/- progeroid mice were used to investigate the role of genistein in lifespan and homeostasis of the aging gut in mammals. A series of longitudinal, clinically relevant measurements were performed to evaluate the effect of genistein on healthspan. It was found that dietary genistein promoted a healthier and longer life and was associated with a decrease in the levels of systemic inflammatory cytokines in aging mice. Furthermore, dietary genistein ameliorated gut dysfunctions, such as intestinal inflammation, leaky gut, and impaired epithelial regeneration. A distinct genistein-mediated alteration in gut microbiota was observed by increasing Lachnospira abundance and short-chain fatty acid (SCFA) production. Further fecal microbiota transplantation and dirty cage sharing experiments indicated that the gut microbiota from genistein-fed mice rejuvenated the aging gut and extended the lifespan of progeroid mice. It was demonstrated that genistein-associated SCFAs alleviated tumor necrosis factor alpha-induced intestinal organoid damage. Moreover, genistein-associated propionate promoted regulatory T cell-derived interleukin 10 production, which alleviated macrophage-derived inflammation. This study provided the first data, to the authors' knowledge, indicating that dietary genistein modulates homeostasis in the aging gut and extends the healthspan and lifespan of aging mammals. Moreover, the existence of a link between genistein and the gut microbiota provides a rationale for dietary interventions against age-associated frailty.


Assuntos
Fragilidade , Microbioma Gastrointestinal , Camundongos , Animais , Longevidade , Genisteína/farmacologia , Ácidos Graxos Voláteis/farmacologia , Envelhecimento , Inflamação , Homeostase , Camundongos Endogâmicos C57BL , Mamíferos
11.
Adv Exp Med Biol ; 1370: 19-28, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35699841

RESUMO

The availability of virucidal compounds to reduce the impact of respiratory viruses is a relevant topic for public health, especially during the recent coronavirus disease (COVID-19) pandemic. Antimicrobial properties of Xibornol are known since the 1970s, but its activity on viruses is currently little explored. In this study, Xibornol activity at a fixed concentration of 0.03 mg/100 ml has been evaluated on five respiratory viruses (Human Adenovirus 5, Human Rhinovirus type 13, Human Coronavirus 229E, Human Parainfluenza Virus type 1, and Human Respiratory Syncytial Virus) through in vitro experiments based on adapted European standard UNI EN 14476-20019. The experiments were carried out under two different environmental conditions, one with the addition of fetal bovine serum to simulate an in vivo condition (dirty condition) and the other without the addition of any organic substances (clean condition). The viral abatement of Xibornol (expressed as Log10 reduction - LR) was statistically significant under both clean and dirty environmental conditions. Namely, in clean condition, LR ranged from 2.67 to 3.84, while in the dirty one the abatement was slightly lower (from 1.75 to 3.03). Parainfluenza Virus and Human Adenovirus were most resistant compared to the other viruses. The obtained data confirmed Xibornol activity and its use as topic substance for viral inactivation to prevent upper respiratory tract disease.


Assuntos
Adenovírus Humanos , COVID-19 , Coronavirus Humano 229E , Vírus Sincicial Respiratório Humano , Infecções Respiratórias , Humanos , Vírus da Parainfluenza 1 Humana , Rhinovirus
12.
J Hosp Infect ; 132: 78-81, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36435309

RESUMO

Effective disinfection strategies are essential to prevent the spread of Mycobacterium tuberculosis. Tuberculocidal efficacy of disinfectants can be demonstrated by testing disinfectants in in-vitro tests, such as the well-established quantitative suspension test EN 14348 using Mycobacterium terrae as a surrogate organism in European disinfectant testing. In other European standard tests, such as EN 13727 and EN 13624, use of the pour plate technique is well established; however, in EN 14348, the spread plate technique alone is considered. Comparative experiments according to EN 14348 with M. terrae were conducted using a peracetic-acid-based disinfectant. Either the pour plate technique or the spread plate technique was used for cultivation. Differences in colony size and morphology were observed when comparing the growth of M. terrae on pour plates compared with spread plates. However, no significant differences in biocidal efficacy data were obtained when applying either spread plates or pour plates in the quantitative suspension test described in EN 14348 under both clean and dirty conditions.


Assuntos
Desinfetantes , Mycobacterium tuberculosis , Humanos , Testes de Sensibilidade Microbiana , Desinfetantes/farmacologia , Micobactérias não Tuberculosas , Desinfecção
13.
Nat Hum Behav ; 7(2): 190-199, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36443501

RESUMO

A central goal of linguistics is to understand how words evolve. Past research has found that macro-level factors such as frequency of word usage and population size explain the pace of lexical evolution. Here we focus on cognitive and affective factors, testing whether valence (positivity-negativity) explains lexical evolution rates. Using estimates of cognate replacement rates for 200 concepts on an Indo-European language tree spanning six to ten millennia, we find that negative valence correlates with faster cognate replacement. This association holds when controlling for frequency of use, and follow-up analyses show that it is most robust for adjectives ('dirty' versus 'clean'; 'bad' versus 'good'); it does not consistently reach statistical significance for verbs, and never reaches significance for nouns. We also present experiments showing that individuals are more likely to replace words for negative versus positive concepts. Our findings suggest that emotional valence affects micro-level guided variation, which drives macro-level valence-dependent mutation in adjectives.


Assuntos
Idioma , Linguística , Humanos , Emoções
14.
Sci Rep ; 12(1): 18638, 2022 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-36329100

RESUMO

Money can be tainted when it is associated with direct or indirect harm to others. Deciding whether to accept "dirty money" poses a dilemma because money can be used to help others, but accepting dirty money has moral costs. How people resolve the dilemma of dirty money remains unknown. One theory casts the dilemma as a valuation conflict that can be resolved by integrating the costs and benefits of accepting dirty money. Here, we use behavioral experiments and computational modeling to test the valuation conflict account and unveil the cognitive computations employed when deciding whether to accept or reject morally tainted cash. In Study 1, British participants decided whether to accept "dirty" money obtained by inflicting electric shocks on another person (versus "clean" money obtained by shocking oneself). Computational models showed that the source of the money (dirty versus clean) impacted decisions by shifting the relative valuation of the money's positive and negative attributes, rather than imposing a uniform bias on decision-making. Studies 2 and 3 replicate this finding and show that participants were more willing to accept dirty money when the money was directed towards a good cause, and observers judged such decisions to be more praiseworthy than accepting dirty money for one's own profit. Our findings suggest that dirty money can be psychologically "laundered" through charitable activities and have implications for understanding and preventing the social norms that can justify corrupt behavior.


Assuntos
Princípios Morais , Humanos
15.
J Hosp Infect ; 128: 80-88, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35944787

RESUMO

BACKGROUND: Dental handpieces (DHPs) are reusable invasive medical devices that must be cleaned, decontaminated, lubricated and steam sterilized after use. DHPs have a complex internal design including narrow channels, contamination of which can compromise sterilization. DHPs are not designed for routine disassembly, making cleaning/decontamination efficacy difficult to monitor. Washer-disinfection is the preferred method of decontaminating DHPs, but few studies have investigated its direct effectiveness at reducing microbial contamination internally. AIMS: To use contra-angle DHPs as a model system to investigate the effectiveness of washer-disinfection at reducing microbial contamination of internal components of multiple DHPs. METHODS: The air and water channels and heads of 10 disassembled contra-angle DHPs (BienAir, Biel/Bienne, Switzerland) were inoculated separately with 108 colony forming units (cfu) of Pseudomanas aeruginosa, Staphylococcus aureus, Enterococcus hirae or Candida albicans in the presence of 0.3% bovine serum albumin (BSA) (clean conditions), 3.0% BSA or 10% artificial test soil (dirty conditions). After reassembly, all 10 DHPs underwent washer-disinfection simultaneously in a Míele (Míele Ireland Ltd., Dublin, Ireland) PG8528 washer-disinfector and were tested for reductions in micro-organisms and protein. Additional experiments were undertaken with three lubricated DHPs inoculated with S. aureus and 10% test soil. All experiments were repeated in triplicate. FINDINGS: On average, an approximate 5 log or greater reduction in microbial cfu and a >93% reduction in protein from DHP heads and channels was consistently recorded following washer-disinfection for all DHPs under all conditions tested. CONCLUSIONS: The internal components of multiple DHPs can be effectively cleaned and decontaminated by washer-disinfection.


Assuntos
Aquaporinas , Desinfecção , Descontaminação/métodos , Detergentes/farmacologia , Desinfecção/métodos , Contaminação de Equipamentos , Hospitais , Humanos , Soroalbumina Bovina , Solo , Staphylococcus aureus , Vapor
16.
J Biomater Appl ; 36(10): 1737-1747, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35244481

RESUMO

Acute wounds are often contaminated by some kind of filth, and fluids are usually used to wash away the dirt, but the force of the fluid may cause secondary injury at the wound site or even increase the risk of infection. Hydrogels have several advantages over liquid scouring since they are less intense, more portable, and easier to control. In this study, poly(vinyl alcohol) was used to prepared a series of hydrogels, which were tested in terms of their properties and abilities to clean simulated dirty wounds. Simulated dirt and bacterial (Serratia marcescens) adhesion experiments demonstrated that they could effectively adhere to a certain amount of dirt or bacteria to achieve the purpose of wound cleaning. In addition to the bacterial adhesion, the antibacterial experiments also proved that the hydrogels have a certain inhibitory effect on the proliferation of E.coli and S.aureus. The hydrogels could change shape freely and exhibited excellent biocompatibility, ductility, and self-healing capabilities, which increase their service life and make them more suitable for treating wounds or acting as protection buffers. Based on all these characteristics, the developed hydrogel may be a potentially valuable material for wound cleaning.


Assuntos
Álcool de Polivinil , Cicatrização , Antibacterianos/farmacologia , Hidrogéis/farmacologia , Staphylococcus aureus
17.
IEEE Trans Cybern ; 52(10): 11014-11026, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34473639

RESUMO

In this article, we propose a novel method to simultaneously solve the data problem of dirty quality and poor quantity for person reidentification (ReID). Dirty quality refers to the wrong labels in image annotations. Poor quantity means that some identities have very few images (FewIDs). Training with these mislabeled data or FewIDs with triplet loss will lead to low generalization performance. To solve the label error problem, we propose a weighted label correction based on cross-entropy (wLCCE) strategy. Specifically, according to the influence range of the wrong labels, we first classify the mislabeled images into point label error and set label error. Then, we propose a weighted triplet loss (WTL) to correct the two label errors, respectively. To alleviate the poor quantity issue, we propose a feature simulation based on autoencoder (FSAE) method to generate some virtual samples for FewID. For the authenticity of the simulated features, we transfer the difference pattern of identities with multiple images (MultIDs) to FewIDs by training an autoencoder (AE)-based simulator. In this way, the FewIDs obtain richer expressions to distinguish from other identities. By dealing with a dirty and poor data problem, we can learn more robust ReID models using the triplet loss. We conduct extensive experiments on two public person ReID datasets: 1) Market-1501 and 2) DukeMTMC-reID, to verify the effectiveness of our approach.

18.
Am J Infect Control ; 50(1): 108-110, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34320408

RESUMO

Pens, common in hospitals, may be a potential vehicle for cross-infection. In this study, the number of pathogens on different pens and the positive rates of several common multi-drug-resistant bacteria were calculated and compared according to the nature of use and material. In addition, the effect of pens on bacterial transmission was explored through simulation experiments. High levels of bacteria were found on pens and the simulations demonstrated transmission of bacteria.


Assuntos
Infecção Hospitalar , Higiene das Mãos , Infecção Hospitalar/microbiologia , Infecção Hospitalar/prevenção & controle , Farmacorresistência Bacteriana Múltipla , Hospitais , Humanos
20.
Front Pharmacol ; 12: 769739, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34966279

RESUMO

Antimicrobial peptides (AMPs) are a promising class of compounds being developed against multi-drug resistant bacteria. Hybridization has been reported to increase antimicrobial activity. Here, two proline-rich peptides (consP1: VRKPPYLPRPRPRPL-CONH2 and Bac5-v291: RWRRPIRRRPIRPPFWR-CONH2) were combined with two arginine-isoleucine-rich peptides (optP1: KIILRIRWR-CONH2 and optP7: KRRVRWIIW-CONH2). Proline-rich antimicrobial peptides (PrAMPs) are known to inhibit the bacterial ribosome, shown also for Bac5-v291, whereas it is hypothesized a "dirty drug" model for the arginine-isoleucine-rich peptides. That hypothesis was underpinned by transmission electron microscopy and biological small-angle X-ray scattering (BioSAXS). The strength of BioSAXS is the power to detect ultrastructural changes in millions of cells in a short time (seconds) in a high-throughput manner. This information can be used to classify antimicrobial compounds into groups according to the ultrastructural changes they inflict on bacteria and how the bacteria react towards that assault. Based on previous studies, this correlates very well with different modes of action. Due to the novelty of this approach direct identification of the target of the antimicrobial compound is not yet fully established, more research is needed. More research is needed to address this limitation. The hybrid peptides showed a stronger antimicrobial activity compared to the proline-rich peptides, except when compared to Bac5-v291 against E. coli. The increase in activity compared to the arginine-isoleucine-rich peptides was up to 6-fold, however, it was not a general increase but was dependent on the combination of peptides and bacteria. BioSAXS experiments revealed that proline-rich peptides and arginine-isoleucine-rich peptides induce very different ultrastructural changes in E. coli, whereas a hybrid peptide (hyP7B5GK) shows changes, different to both parental peptides and the untreated control. These different ultrastructural changes indicated that the mode of action of the parental peptides might be different from each other as well as from the hybrid peptide hyP7B5GK. All peptides showed very low haemolytic activity, some of them showed a 100-fold or larger therapeutic window, demonstrating the potential for further drug development.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA