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1.
Heliyon ; 10(8): e29456, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38660253

RESUMO

Modern road infrastructures are complex networks featuring various elements such as roads, bridges, intersections, and roundabouts, with advanced control systems. Roundabouts have gained prominence as a safer alternative to traditional intersections promoting smoother traffic flow and fewer collisions by guiding traffic in one direction, encouraging reduced speed, and minimizing conflict points.This study investigated driver behavior within roundabouts, focusing on gaze behavior, particularly the left-side mirror and window, under mobile phone distraction conditions. In addition, the effects of roundabout specifications (i.e., number of lanes and size of the central island) and the drivers' characteristics (i.e., driving experience) were examined.In total, 43 participants, aged 19-56 years including 30 males and 13 females, held a valid driving license, drove through a virtual simulated urban road containing four roundabouts, implemented in a static driving simulator, under baseline condition (no distraction) as well as mobile-induced distraction. Driving simulator data were collected and drivers' gaze direction and fixation on nine areas of interest were captured with an eye tracker. Results: showed that experienced drivers exhibit a more fixation on the left-side mirror and window and were less distracted. Moreover, the road environment, i.e., the number of cars and the roundabout size, significantly influenced the drivers' attention. As regards the driving performance, the number of infractions increased when the drivers diverted focus from the left side of the car. The outcomes of the present study might help to improve traffic safety at roundabouts.

2.
Pediatr Infect Dis J ; 43(3): 257-262, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38063508

RESUMO

BACKGROUND: We aimed to determine the prevalence and severity of glomerular and tubular renal dysfunction by means of urinalysis in infants and toddlers with congenital cytomegalovirus infection (cCMV) and their association with cCMV disease, viruria and antiviral treatment. METHODS: This cross-sectional study was done using the Spanish Registry of Congenital Cytomegalovirus Infection. First-morning urine samples were collected from January 2016 to December 2018 from patients <5 years old enrolled in Spanish Registry of Congenital Cytomegalovirus Infection. Samples were excluded in case of fever or other signs or symptoms consistent with acute infection, bacteriuria or bacterial growth in urine culture. Urinary protein/creatinine and albumin/creatinine ratios, urinary beta-2-microglobulin levels, hematuria and CMV viruria were determined. A 0.4 cutoff in the urinary albumin/protein ratio was used to define tubular (<0.4) or glomerular (>0.4) proteinuria. Signs and symptoms of cCMV at birth, the use of antivirals and cCMV-associated sequelae at last available follow-up were obtained from Spanish Registry of Congenital Cytomegalovirus Infection. RESULTS: Seventy-seven patients (37 females, 48.1%; median [interquartile range] age: 14.0 [4.4-36.2] months) were included. Symptom-free elevated urinary protein/creatinine and albumin/creatinine ratios were observed in 37.5% and 41.9% of patients, respectively, with tubular proteinuria prevailing (88.3%) over glomerular proteinuria (11.6%). Proteinuria in the nephrotic range was not observed in any patients. In multivariate analysis, female gender was the only risk factor for tubular proteinuria (adjusted odds ratio = 3.339, 95% confidence interval: 1.086-10.268; P = 0.035). cCMV disease at birth, long-term sequelae, viruria or the use of antivirals were not associated with urinalysis findings. CONCLUSIONS: Mild nonsymptomatic tubular proteinuria affects approximately 40% of infants and toddlers with mostly symptomatic cCMV in the first 5 years of life.


Assuntos
Infecções por Citomegalovirus , Citomegalovirus , Recém-Nascido , Lactente , Humanos , Feminino , Adolescente , Pré-Escolar , Estudos Transversais , Creatinina , Infecções por Citomegalovirus/complicações , Infecções por Citomegalovirus/epidemiologia , Infecções por Citomegalovirus/diagnóstico , Proteinúria/epidemiologia , Proteinúria/complicações , Antivirais/uso terapêutico , Rim , Albuminas/uso terapêutico
3.
J Safety Res ; 80: 428-440, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35249624

RESUMO

INTRODUCTION: This research relates the most important work-related factors affecting the development of hearing loss to the main methods used as medical assessment criteria in the diagnosis of occupational deafness. These criteria are the Speech Average Loss Index (SAL), the Early Loss Index (ELI) and the Percentage of Hearing Loss, and are applied to data obtained from audiograms performed on workers in occupational medical examinations. METHOD: Depending on the assessment method selected, these often return different results in grading an individual's hearing status and predicting how it will evolve. To address this problem, medical examinations (including audiograms) were carried out on a heterogeneous sample of 1,418 workers in Spain, from which demographic or personal data (gender, age, etc.), occupational data (noise level to which each individual is exposed, etc.) and other non-work-related factors (exposure to noise outside work, family history, etc.) were also gathered. Using Bayesian Networks, the conditional probability of an individual developing hearing loss was obtained taking into account all these factors and, specifically, noise level and length of service in the workplace. Sensitivity analyses were also carried out using the three scales (SAL, ELI and Percentage Hearing Loss Index), proving their suitability as tools the diagnosis and prediction of deafness. These networks were validated under the Receiver Operating Characteristic curve (ROC) criterion and in particular by the Area Under the Curve (AUC). RESULTS: The results show that all three methods are deficient in so far as detecting preventive hearing problems related to noise in most workplaces. CONCLUSIONS: The most restrictive methods for detecting possible cases of deafness are the SAL index and the Percentage Loss Index. The ELI index is the least restrictive of the three methods, but it is not able to discriminate the causes of hearing problems in an individual caused by exposure to noise, either by its intensity level or by the time of exposure to noise. Practical Applications: The use of the three methods in the field of occupational risk prevention is extremely limited and it seems reasonable to think that there is a need for the construction of new scales to correct or improve the existing ones.


Assuntos
Surdez , Perda Auditiva Provocada por Ruído , Ruído Ocupacional , Doenças Profissionais , Exposição Ocupacional , Teorema de Bayes , Surdez/complicações , Perda Auditiva Provocada por Ruído/diagnóstico , Perda Auditiva Provocada por Ruído/epidemiologia , Perda Auditiva Provocada por Ruído/prevenção & controle , Humanos , Ruído Ocupacional/efeitos adversos , Ruído Ocupacional/prevenção & controle , Doenças Profissionais/diagnóstico , Doenças Profissionais/epidemiologia , Doenças Profissionais/prevenção & controle , Local de Trabalho
4.
Artigo em Inglês | MEDLINE | ID: mdl-34281034

RESUMO

The use of communication technologies, e.g., mobile phones, has increased dramatically in recent years, and their use among drivers has become a great risk to traffic safety. The present study assessed the workload and road ordinary violations, utilizing driving data collected from 39 young participants who underwent a dual-task while driving a simulator, i.e., respond to a call, text on WhatsApp, and check Instagram. Findings confirmed that there are significant differences in the driving performance of young drivers in terms of vehicle control (i.e., lateral distance and hard shoulder line violations) between distracted and non-distracted drivers. Furthermore, the overall workload score of young drivers increases with the use of their mobile phones while driving. The obtained results contribute to a better understanding of the driving performance of distracted young drivers and thus they could be useful for further improvements to traffic safety strategies.


Assuntos
Condução de Veículo , Uso do Telefone Celular , Telefone Celular , Envio de Mensagens de Texto , Acidentes de Trânsito , Humanos , Carga de Trabalho
5.
Artigo em Inglês | MEDLINE | ID: mdl-34281092

RESUMO

Multitasking while driving negatively affects driving performance and threatens people's lives every day. Moreover, technology-based distractions are among the top driving distractions that are proven to divert the driver's attention away from the road and compromise their safety. This study employs recent data on road traffic accidents that occurred in Spain and uses a machine-learning algorithm to analyze, in the first place, the influence of technology-based distracted driving on drivers' infractions considering the gender and age of the drivers and the zone and the type of vehicle. It assesses, in the second place, the impact of drivers' infractions on the severity of traffic accidents. Findings show that (i) technology-based distractions are likely to increase the probability of committing aberrant infractions and speed infractions; (ii) technology-based distracted young drivers are more likely to speed and commit aberrant infractions; (iii) distracted motorcycles and squad riders are found more likely to speed; (iv) the probability of committing infractions by distracted drivers increases on streets and highways; and, finally, (v) drivers' infractions lead to serious injuries.


Assuntos
Condução de Veículo , Direção Distraída , Acidentes de Trânsito , Humanos , Segurança , Espanha/epidemiologia , Tecnologia
6.
J Safety Res ; 76: 289-300, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33653561

RESUMO

INTRODUCTION: Modern approaches to Occupational Health and Safety have acknowledged the important contribution that continuous improvements to working conditions can make to the motivation of employees, their subsequent performance, and therefore to the competitiveness of the company. Despite this fact, organizational change initiatives represent a path less traveled by employees. Specialized literature has drawn on the fact that employees' satisfaction presents both the foundation and catalyst for effective implementation of improvements to working conditions. METHOD: This paper conceptualizes the alignment of employees through measurement of job satisfaction and uses the Bayesian Network to assess the influence of human factors, particularly the cognitive, emotional, and behavioral aspects. Toward this aim, the Bayesian Network is evaluated through a cross-validation process, and a sensitivity analysis is then conducted for each influential dimension: emotional, cognitive, and behavioral. RESULTS: The results reveal that these three dimensions are interrelated and have a direct influence on job satisfaction and employees' alignment during the organization change. Further, they suggest that the best strategy for enhanced alignment and smooth conduct of organizational changes is simultaneous enhancement of the three dimensions. Practical applications: This study shows the influence of emotional, cognitive, and behavioral dimensions on job satisfaction and employees' alignment during the organizational change. Furthermore, it elaborates the way to develop efficient and effective strategies for a successful change implementation and sustained alignment.


Assuntos
Satisfação no Emprego , Saúde Ocupacional/estatística & dados numéricos , Inovação Organizacional , Teorema de Bayes , Cognição , Emoções , Humanos
7.
Artigo em Inglês | MEDLINE | ID: mdl-33142803

RESUMO

Hearing loss affects hundreds of millions of people all over the world, leading to several types of disabilities, ranging from purely physical to psychological and/or social aspects. A proper analysis to ascertain the main risk factors is essential in order to diagnose early and treat adequately. An exploratory analysis based on a heterogeneous sample of 1418 workers is presented in order to identify the main trigger factors for hearing loss. On the one hand, we recorded several medical and environmental parameters, and on the other, we created a model based on Bayesian networks in order to be able to infer the probability of hearing loss considering different scenarios. This paper focuses on three parameters: gender, age, and a family history of hearing problems. The results obtained allow us to infer or predict the best or worst auditory level for an individual under several different scenarios. The least relevant factor is the existence of a family history of deafness, followed by the gender factor, which slopes considerably toward better hearing for females, and most prominent of all, the age factor, given the large differences identified between the various age groups when the gender and family history of deafness variables remain constant.


Assuntos
Surdez , Perda Auditiva , Adulto , Fatores Etários , Teorema de Bayes , Feminino , Audição , Perda Auditiva/epidemiologia , Perda Auditiva/genética , Humanos , Masculino , Anamnese , Pessoa de Meia-Idade , Fatores Sexuais
8.
Radiographics ; 40(7): 2117-2141, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33095681

RESUMO

The postpartum period, also known as the puerperium, begins immediately after delivery of the neonate and placenta and ends 6-8 weeks after delivery. The appearance of physiologic uterine changes during puerperium can overlap with that of postpartum complications, which makes imaging interpretation and diagnosis difficult. Obstetric and nonobstetric postpartum complications are a considerable source of morbidity and mortality in women of reproductive age, and the radiologist plays an important role in the assessment of these entities, which often require a multimodality imaging approach. US and contrast material-enhanced CT are the techniques of choice in the emergency department, and they can show characteristic radiologic findings that enable differentiation between normal and abnormal features to help radiologists and emergency department practitioners to reach a correct diagnosis and provide timely treatment. The spectrum of postpartum complications ranges from relatively self-limiting to life-threatening conditions that can be divided into six categories: infectious conditions (endometritis), thrombotic complications (eg, deep vein thrombosis, ovarian vein thrombophlebitis, HELLP [hemolysis, elevated liver enzymes, and low platelet count] syndrome, or cerebral sinus thrombosis), hemorrhagic conditions (eg, uterine atony, trauma of the lower portion of the genital tract, retained products of conception, uterine artery arteriovenous malformations, or uterine artery pseudoaneurysm), cesarean delivery-related complications (eg, bladder flap hematoma, subfascial hematoma, rectus sheath hematoma, abscess formation, uterine dehiscence, uterine rupture, vesicovaginal fistula, or abdominal wall endometriosis), iatrogenic conditions (eg, uterine perforation), and nonobstetric complications (eg, acute cholecystitis, acute appendicitis, uterine fibroid degeneration, renal cortical necrosis, pyelonephritis, posterior reversible encephalopathy syndrome, or pituitary gland apoplexy). The online slide presentation from the RSNA Annual Meeting is available for this article. ©RSNA, 2020.


Assuntos
Transtornos Puerperais/diagnóstico por imagem , Adulto , Meios de Contraste , Feminino , Humanos , Gravidez
9.
Artigo em Inglês | MEDLINE | ID: mdl-32947935

RESUMO

Road traffic plays a vital role in countries' economic growth and future development. However, traffic accidents are considered a major public health issue affecting humankind. Despite efforts by governments to improve traffic safety, the misalignment between the policy efforts and on-ground infringements, distractions and breaches reflect the regulatory failure. This paper uses the Bayesian network method to investigate unsafe behaviors and traffic accidents involving unlicensed drivers as a perspective for the regulatory alignment assessment. The findings suggest that: (1) unlicensed drivers are more likely to have unsafe driving behaviors; (2) the probability of being involved in a severe traffic accident increases when the drivers are unlicensed and decreases in the case of licensed drivers; (3) young drivers are noticeably more likely to engage in unsafe behaviors, usually leading to serious injuries and deaths, when their driving licenses are invalid; (4) women are more likely to engage in right-of-way violations and to have collisions with no serious injuries, contrary to unlicensed men drivers, who are involved in other types of traffic accidents resulting in serious injuries.


Assuntos
Acidentes de Trânsito , Condução de Veículo , Envio de Mensagens de Texto , Adulto , Idoso , Teorema de Bayes , Feminino , Humanos , Licenciamento , Masculino , Pessoa de Meia-Idade , Saúde Pública , Adulto Jovem
10.
Artigo em Inglês | MEDLINE | ID: mdl-31877756

RESUMO

This study analyses factors associated with cyclist injury severity, focusing on vehicle type, route environment, and interactions between them. Data analysed was collected by Spanish police during 2016 and includes records relating to 12,318 drivers and cyclist involving in collisions with at least one injured cyclist, of whom 7230 were injured cyclists. Bayesian methods were used to model relationships between cyclist injury severity and circumstances related to the crash, with the outcome variable being whether a cyclist was killed or seriously injured (KSI) rather than slightly injured. Factors in the model included those relating to the injured cyclist, the route environment, and involved motorists. Injury severity among cyclists was likely to be higher where an Heavy Goods Vehicle (HGV) was involved, and certain route conditions (bicycle infrastructure, 30 kph zones, and urban zones) were associated with lower injury severity. Interactions exist between the two: collisions involving large vehicles in lower-risk environments are less likely to lead to KSIs than collisions involving large vehicles in higher-risk environments. Finally, motorists involved in a collision were more likely than the injured cyclists to have committed an error or infraction. The study supports the creation of infrastructure that separates cyclists from motor traffic. Also, action needs to be taken to address motorist behaviour, given the imbalance between responsibility and risk.


Assuntos
Acidentes de Trânsito/estatística & dados numéricos , Ciclismo/lesões , Meio Ambiente , Veículos Automotores/estatística & dados numéricos , Adolescente , Adulto , Idoso , Teorema de Bayes , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Veículos Automotores/classificação , Polícia , Espanha , Adulto Jovem
11.
Biomed Res Int ; 2017: 4673047, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29250540

RESUMO

Healthcare professionals undergo high levels of occupational stress as a result of their working conditions. Thus, the aim of this study is to develop a model that focuses on healthcare professionals so as to analyze the influence that job demands, control, social support, and recognition have on the likelihood that a worker will experience stress. The data collected correspond to 2,211 healthcare workers from 35 countries, as reported in the sixth European Working Condition Survey (EWCS). The results obtained from this study allow us to infer stress under several working condition scenarios and to identify the more relevant variables in order to reduce this stress in healthcare professionals, which is of paramount importance to managing the stress of workers in this sector. The Bayesian network proposed indicates that emotional demands have a greater influence on raising the likelihood of stress due to workload than do family demands. The results show that the support of colleagues, in general, has less effect on reducing stress than social support from superiors. Furthermore, the sensitivity analysis shows that, in high-demand and low-control situations, recognition clearly impacts stress, drastically reducing it.


Assuntos
Pessoal de Saúde/psicologia , Modelos Psicológicos , Saúde Ocupacional , Estresse Ocupacional/psicologia , Reconhecimento Psicológico , Apoio Social , Adulto , Teorema de Bayes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários , Carga de Trabalho
12.
Accid Anal Prev ; 57: 114-23, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23672926

RESUMO

Occupational stress is a major health hazard and a serious challenge to the effective operation of any company and represents a major problem for both individuals and organizations. Previous researches have shown that high demands (e.g. workload, emotional) combined with low resources (e.g. support, control, rewards) are associated with adverse health (e.g. psychological, physical) and organizational impacts (e.g. reduced job satisfaction, sickness absence). The objective of the present work is to create a model to analyze how social support reduces the occupational stress caused by work demands. This study used existing Spanish national data on working conditions collected by the Spanish Ministry of Labour and Immigration in 2007, where 11,054 workers were interviewed by questionnaire. A probabilistic model was built using Bayesian networks to explain the relationships between work demands and occupational stress. The model also explains how social support contributes positively to reducing stress levels. The variables studied were intellectually demanding work, overwork, workday, stress, and social support. The results show the importance of social support and of receiving help from supervisors and co-workers in preventing occupational stress. The study provides a new methodology that explains and quantifies the effects of intellectually demanding work, overwork, and workday in occupational stress. Also, the study quantifies the importance of social support to reduce occupational stress.


Assuntos
Doenças Profissionais/epidemiologia , Doenças Profissionais/prevenção & controle , Saúde Ocupacional , Apoio Social , Estresse Psicológico/epidemiologia , Estresse Psicológico/prevenção & controle , Adulto , Teorema de Bayes , Feminino , Humanos , Satisfação no Emprego , Masculino , Fatores de Risco , Sensibilidade e Especificidade , Espanha/epidemiologia , Carga de Trabalho
13.
BMC Infect Dis ; 13: 503, 2013 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-24498901

RESUMO

BACKGROUND: The World Health Organization reported in 2007 that inclusion of PCV7 in national immunization programs should be seen as a priority, also encouraging countries to conduct appropriate surveillances for monitoring the impact of vaccination. These analyses should be conducted in specific geographical areas and should be aimed to evolution of invasive pneumococcal disease (IPD), by age groups, clinical presentation, and vaccine serotypes (and non-vaccine serotypes to detect possible replacement). This study aimed to monitor the evolution of IPD incidence in children <15 years requiring hospitalization in the Island of Majorca. METHODS: A prospective clinical surveillance of all culture and/or PCR-confirmed IPD in children <15 years was performed in all hospitals in the Island of Majorca (approximately 900,000 inhabitants) from January 2008 to December 2010. Incidence rate (IR) was calculated as cases/100,000 inhabitants using children population data. RESULTS: 66 IPDs were identified: 39 (59.1%) parapneumonic pneumococcal empyema (PPE), 16 (24.2%) bacteremic pneumonia (BP), 7 (10.6%) primary bacteremia, 3 (4.5%) meningitis, and 1 (1.5%) osteomyelitis. IRs in the three-year study period were: 64.22 for children 12- < 24 months, 37.21 for those 24-59 months, 22.62 for those <12 months, and 3.98 for children >59 months. By study year, IRs were 21.25 in 2008, 19.89 in 2009 and 9.80 in 2010. The reduction found in 2010 was significant and due to significant reductions in IRs of IPDs caused by serotypes included in PCV10 and PCV13. Overall, estimated serotype coverage by conjugate vaccines was 12.1% for PCV7, 37.9% for PCV10 and 65.2% for PCV13. Of the 66 hospitalized children with IPD, 20 had received at least one dose of PCV7 (13 cases with identified serotype). None of these 13 cases was caused by PCV7 serotypes, all were caused by PCV13 serotypes and only 53.8% by PCV10 serotypes. CONCLUSIONS: The results of the present study evidence the importance of expanding the number of serotypes covered by PCV, and the added value of PCV13 with respect to PCV10 and PCV7, even in an area of low prevalence of 19A as the Island of Majorca.


Assuntos
Infecções Pneumocócicas/epidemiologia , Infecções Pneumocócicas/prevenção & controle , Vacinas Pneumocócicas/administração & dosagem , Streptococcus pneumoniae/imunologia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Infecções Pneumocócicas/imunologia , Infecções Pneumocócicas/microbiologia , Estudos Prospectivos , Sorotipagem , Espanha/epidemiologia , Streptococcus pneumoniae/classificação , Vacinação , Vacinas Conjugadas/administração & dosagem
14.
J Safety Res ; 43(5-6): 365-74, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23206509

RESUMO

INTRODUCTION: Occupational stress is a common phenomenon in our society, and generates problems for both workers' health and the functioning of organizations. Over past decades numerous studies have examined occupational stress from the perspective of gender, offering somewhat contradictory results. Some of them found no differences and others indicated that either men or women suffer from greater amounts of occupational stress. METHOD: The purpose of this study was to analyze gender differences in stress in situations that involve certain occupational demands. The data used were taken from a random sample population of 11,054 (5,917 men and 5,137 women) from the VI National Survey on Working Conditions (NSWC) which was conducted in Spain in 2007. To carry out this study, a probabilistic model was constructed using Bayesian networks, with the following variables related to task demands: working with tight deadlines, quick work, intellectually demanding work, complicated tasks, repetitive tasks, excessive work, and work demanding high attention levels. RESULTS: The results of this study reveal that: the indicators studied significantly increased stress levels; women initially had higher stress levels than men; and when exposed to determined task demands, stress differences between genders tended to increase. IMPACT ON INDUSTRY: Companies need to consider the gender of their workers when assigning tasks in high demand/stress jobs.


Assuntos
Saúde Ocupacional , Estresse Psicológico , Adulto , Teorema de Bayes , Feminino , Humanos , Indústrias , Masculino , Pessoa de Meia-Idade , Fatores Sexuais , Espanha , Análise e Desempenho de Tarefas , Carga de Trabalho
15.
J Org Chem ; 68(11): 4582-5, 2003 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-12762778

RESUMO

An efficient and stereocontrolled synthesis of phenylalanine- and tryptophan-derived 5-phenyl-1,4-benzodiazepines is described. This new methodology involves, as a key step, the synthesis of 5-phenyl-2,3-dihydro-1H-1,4-benzodiazepines by a one-pot cyano reduction and reductive cyclization of the appropriate amino nitrile, which were obtained via a modified Strecker reaction of N-protected alpha-amino aldehydes with 2-aminobenzophenone and trimethylsilyl cyanide. The subsequent reduction of these 2,3-dihydro-1H-1,4-benzodiazepines, followed by regioselective alkylation or acylation at position 4, led to 2,4-disubstituted-5-phenyl-2,3,4,5-tetrahydro-1H-1,4-benzodiazepine.

16.
J Safety Res ; 33(1): 1-20, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-11979632

RESUMO

This editorial reviews the evolution of the concepts of safety and quality that have been used in the traditional workplace. The traditional programs of safety are explored showing strengths and weaknesses. The concept of quality management is also viewed. Safety management and quality management principles, stages, and measurement are highlighted. The concepts of quality and safety guarantee are assessed. Total Quality Management concepts are reviewed and applied to safety quality. Total safety management principles are discussed. Finally, an analysis of the relationship between quality and safety from data collected from a company in Spain is presented.


Assuntos
Gestão da Segurança/métodos , Gestão da Segurança/normas , Gestão da Qualidade Total/métodos , Humanos , Modelos Organizacionais , Saúde Ocupacional , Política Organizacional
17.
J Org Chem ; 67(11): 3866-73, 2002 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-12027705

RESUMO

2-Oxopiperazine derivatives 1 have been designed as mimetics of gamma-turn conformationally constrained tripeptides. The synthetic pathway devised for the preparation of both epimers of 1 at C(5) involves a reductive amination of cyanomethyleneamino pseudopeptides with amino acid derivatives, followed by regiospecific lactamization of the resulting C-backbone branched pseudopeptides. The versatility of this methodology is illustrated in the synthesis of analogues of the tetrapeptides Boc-[Nle(31)]-CCK-4 and Boc-[Lys(o-tolylaminocarbonyl)(31)]-CCK-4. The introduction of the new conformational restriction into these Boc-CCK-4 analogues led to a loss of 2 or 3 orders of magnitude in the affinity at CCK receptors. These results suggest the absence of a gamma-turn in the bioactive conformation of the C-terminal tripeptide of CCK-4.


Assuntos
Peptídeos/síntese química , Piperazinas/química , Tetragastrina/análogos & derivados , Animais , Córtex Cerebral/metabolismo , Modelos Moleculares , Mimetismo Molecular , Ressonância Magnética Nuclear Biomolecular , Pâncreas/metabolismo , Peptídeos/química , Peptídeos/metabolismo , Piperazinas/síntese química , Piperazinas/metabolismo , Conformação Proteica , Ratos , Receptor de Colecistocinina B , Receptores da Colecistocinina/metabolismo , Tetragastrina/metabolismo
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