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1.
Transfusion ; 62(9): 1923-1926, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35872641

RESUMO

BACKGROUND: Multiple reports suggest that cold-stored low-titer type O whole blood (LTOWB) is becoming a preferred transfusion product for resuscitating massive hemorrhage across trauma, obstetrical, and pediatric services. However, we know of no reports of using this product for emergency transfusion of newborn infants after acute severe hemorrhage. CASE REPORT: We report our experience with emergency transfusion of re-warmed LTOWB using a fluid warmer for the resuscitation of a hypotensive 25-week gestation neonate following acute and severe placental abruption. The transfusion was tolerated well, without evidence of hemolysis or other complications. CONCLUSIONS: This is the first report of which we are aware of transfusing warmed LTOWB to a preterm neonate. Our positive experience leads us to speculate that this product could have a role for neonates following acute severe blood loss.


Assuntos
Recém-Nascido de Peso Extremamente Baixo ao Nascer , Ferimentos e Lesões , Sistema ABO de Grupos Sanguíneos , Transfusão de Sangue , Criança , Feminino , Hemorragia/etiologia , Hemorragia/terapia , Humanos , Lactente , Recém-Nascido , Placenta , Gravidez , Ressuscitação
2.
Evol Comput ; 30(3): 409-446, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34902015

RESUMO

An optimal recombination operator for two-parent solutions provides the best solution among those that take the value for each variable from one of the parents (gene transmission property). If the solutions are bit strings, the offspring of an optimal recombination operator is optimal in the smallest hyperplane containing the two parent solutions. Exploring this hyperplane is computationally costly, in general, requiring exponential time in the worst case. However, when the variable interaction graph of the objective function is sparse, exploration can be done in polynomial time. In this article, we present a recombination operator, called Dynastic Potential Crossover (DPX), that runs in polynomial time and behaves like an optimal recombination operator for low-epistasis combinatorial problems. We compare this operator, both theoretically and experimentally, with traditional crossover operators, like uniform crossover and network crossover, and with two recently defined efficient recombination operators: partition crossover and articulation points partition crossover. The empirical comparison uses NKQ Landscapes and MAX-SAT instances. DPX outperforms the other crossover operators in terms of quality of the offspring and provides better results included in a trajectory and a population-based metaheuristic, but it requires more time and memory to compute the offspring.


Assuntos
Algoritmos
3.
Gut ; 66(6)June 2017.
Artigo em Inglês | BIGG - guias GRADE | ID: biblio-948494

RESUMO

The risks of poor transition include delayed and inappropriate transfer that can result in disengagement with healthcare. Structured transition care can improve control of chronic digestive diseases and long-term health-related outcomes. These are the first nationally developed guidelines on the transition of adolescent and young persons (AYP) with chronic digestive diseases from paediatric to adult care. They were commissioned by the Clinical Services and Standards Committee of the British Society of Gastroenterology under the auspices of the Adolescent and Young Persons (A&YP) Section. Electronic searches for English-language articles were performed with keywords relating to digestive system diseases and transition to adult care in the Medline (via Ovid), PsycInfo (via Ovid), Web of Science and CINAHL databases for studies published from 1980 to September 2014. The quality of evidence and grading of recommendations was appraised using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. The limited number of studies in gastroenterology and hepatology required the addition of relevant studies from other chronic diseases to be included.These guidelines deal specifically with the transition of AYP living with a diagnosis of chronic digestive disease and/or liver disease from paediatric to adult healthcare under the following headings;1. Patient populations involved in AYP transition. 2. Risks of failing transition or poor transition. 3. Models of AYP transition. 4. Patient and carer/parent perspective in AYP transition. 5. Surgical perspective.(AU)


Assuntos
Humanos , Adolescente , Adulto , Transição para Assistência do Adulto/normas , Gastroenteropatias/terapia , Hepatopatias/terapia , Avaliação de Processos e Resultados em Cuidados de Saúde , Fatores de Tempo , Educação de Pacientes como Assunto , Doença Crônica , Abordagem GRADE
4.
Evol Comput ; 24(3): 491-519, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27120114

RESUMO

This article investigates Gray Box Optimization for pseudo-Boolean optimization problems composed of M subfunctions, where each subfunction accepts at most k variables. We will refer to these as Mk Landscapes. In Gray Box Optimization, the optimizer is given access to the set of M subfunctions. We prove Gray Box Optimization can efficiently compute hyperplane averages to solve non-deceptive problems in [Formula: see text] time. Bounded separable problems are also solved in [Formula: see text] time. As a result, Gray Box Optimization is able to solve many commonly used problems from the evolutional computation literature in [Formula: see text] evaluations. We also introduce a more general class of Mk Landscapes that can be solved using dynamic programming and discuss properties of these functions. For certain type of problems Gray Box Optimization makes it possible to enumerate all local optima faster than brute force methods. We also provide evidence that randomly generated test problems are far less structured than those found in real-world problems.


Assuntos
Modelos Teóricos
5.
Evol Comput ; 23(2): 217-48, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-24885680

RESUMO

Bit-flip mutation is a common mutation operator for evolutionary algorithms applied to optimize functions over binary strings. In this paper, we develop results from the theory of landscapes and Krawtchouk polynomials to exactly compute the probability distribution of fitness values of a binary string undergoing uniform bit-flip mutation. We prove that this probability distribution can be expressed as a polynomial in p, the probability of flipping each bit. We analyze these polynomials and provide closed-form expressions for an easy linear problem (Onemax), and an NP-hard problem, MAX-SAT. We also discuss a connection of the results with runtime analysis.


Assuntos
Algoritmos , Matemática , Modelos Teóricos , Evolução Biológica , Simulação por Computador , Modelos Estatísticos , Mutação
6.
Evol Comput ; 21(4): 561-90, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23163780

RESUMO

The frequency distribution of a fitness function over regions of its domain is an important quantity for understanding the behavior of algorithms that employ randomized sampling to search the function. In general, exactly characterizing this distribution is at least as hard as the search problem, since the solutions typically live in the tails of the distribution. However, in some cases it is possible to efficiently retrieve a collection of quantities (called moments) that describe the distribution. In this paper, we consider functions of bounded epistasis that are defined over length-n strings from a finite alphabet of cardinality q. Many problems in combinatorial optimization can be specified as search problems over functions of this type. Employing Fourier analysis of functions over finite groups, we derive an efficient method for computing the exact moments of the frequency distribution of fitness functions over Hamming regions of the q-ary hypercube. We then use this approach to derive equations that describe the expected fitness of the offspring of any point undergoing uniform mutation. The results we present provide insight into the statistical structure of the fitness function for a number of combinatorial problems. For the graph coloring problem, we apply our results to efficiently compute the average number of constraint violations that lie within a certain number of steps of any coloring. We derive an expression for the mutation rate that maximizes the expected fitness of an offspring at each fitness level. We also apply the results to the slightly more complex frequency assignment problem, a relevant application in the domain of the telecommunications industry. As with the graph coloring problem, we provide formulas for the average value of the fitness function in Hamming regions around a solution and the expectation-optimal mutation rate.


Assuntos
Algoritmos , Distribuições Estatísticas , Análise de Fourier , Ondas de Rádio , Processos Estocásticos
7.
Evol Comput ; 19(4): 597-637, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21469972

RESUMO

A small number of combinatorial optimization problems have search spaces that correspond to elementary landscapes, where the objective function f is an eigenfunction of the Laplacian that describes the neighborhood structure of the search space. Many problems are not elementary; however, the objective function of a combinatorial optimization problem can always be expressed as a superposition of multiple elementary landscapes if the underlying neighborhood used is symmetric. This paper presents theoretical results that provide the foundation for algebraic methods that can be used to decompose the objective function of an arbitrary combinatorial optimization problem into a sum of subfunctions, where each subfunction is an elementary landscape. Many steps of this process can be automated, and indeed a software tool could be developed that assists the researcher in finding a landscape decomposition. This methodology is then used to show that the subset sum problem is a superposition of two elementary landscapes, and to show that the quadratic assignment problem is a superposition of three elementary landscapes.


Assuntos
Matemática/métodos , Software
8.
Med Teach ; 21(6): 594-6, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-21281182

RESUMO

This study compared medical student evaluations of ambulatory and inpatient components of third-year clerkships in internal medicine, obstetrics/gynaecology, paediatrics, psychiatry, and surgery. Seventy-two students completed evaluation questionnaires at the conclusion of each of five clerkships over 12 months. Although ambulatory and inpatient evaluations were comparable across all five specialties in several areas, ambulatory education was rated more favorably in scheduling, clear definition of student roles and responsibilities, appropriate supervision, timely and constructive feedback, being welcomed, and working in a non-threatening environment.Student feedback thus implied that ambulatory experiences were comparable to, or better than, inpatient experiences and suggests areas for improving clinical education in inpatient settings.

10.
Hosp Health Netw ; 70(13): 24-5, 1996 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-8653129

RESUMO

Defining the values at stake as we move into managed care is an awesome--yet necessary--endeavor. To help sort things out, the Society for Health and Human Values brought together health care ethicists and medical humanists to discuss how human values are being incorporated into health care reform. Here's an excerpt from that conversation.


Assuntos
Ética Institucional , Programas de Assistência Gerenciada/normas , Eticistas , Comissão de Ética , Reforma dos Serviços de Saúde/normas , Papel Profissional , Valores Sociais , Estados Unidos
11.
Epilepsia ; 33(1): 112-8, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1733743

RESUMO

ADD 94057, a metabolite of fluzinamide, manufactured by the A. H. Robins Company, blocks chemically- and electrically-induced seizures in animals. The primary objective of this open add-on study was to evaluate patient tolerability of ADD 94057 at ascending target plasma concentrations. Nine subjects with medically refractory seizures were receiving phenytoin (PHT, 3), carbamazepine (CBZ, 3), or both (3). A pharmacokinetic profile after a single oral 400-mg dose of ADD 94057 was used to calculate ADD 94057 dosages. After a 4-week baseline period, patients were treated for 4 weeks with weekly ADD 94057 dosage escalations. Two patients completed the study at their assigned highest dosage level; the other patients finished the study at lower dosages. The patients receiving PHT (but not CBZ) tolerated higher plasma concentrations of ADD 94057 than did patients receiving CBZ, alone or in combination with PHT. Adverse experiences included headache, ataxia, blurred vision, diplopia, dizziness, lightheadedness, and mild confusion. Eight of nine patients had reductions in seizure frequency from baseline.


Assuntos
Anticonvulsivantes/farmacocinética , Azetidinas/farmacocinética , Epilepsias Parciais/tratamento farmacológico , Administração Oral , Adulto , Anticonvulsivantes/administração & dosagem , Anticonvulsivantes/sangue , Azetidinas/administração & dosagem , Azetidinas/sangue , Carbamazepina/farmacologia , Relação Dose-Resposta a Droga , Esquema de Medicação , Interações Medicamentosas , Quimioterapia Combinada , Tolerância a Medicamentos , Feminino , Humanos , Masculino , Fenitoína/farmacologia , Probabilidade
12.
Epilepsia ; 29(6): 770-4, 1988.
Artigo em Inglês | MEDLINE | ID: mdl-3191893

RESUMO

This preliminary clinical study describes the pharmacokinetic characteristics of flunarizine (FLN) following single and multiple dosing in epileptic patients receiving comedication. Three groups [phenytoin (PHT) only, carbamazepine (CBZ) only, and PHT plus CBZ] of four patients each were studied. Large interindividual differences, but no statistically significant differences in pharmacokinetic parameters, were observed between the three groups. Following a single dose, mean values (and ranges) for apparent clearance, volume distribution, and elimination half-life (t1/2) were 0.504 L/h/kg (0.086-1.119), 12,431 L (1,959-20,920), and 308 h (61-506), respectively. FLN had no effect on PHT or CBZ steady-state levels but PHT or CBZ appeared to induce the metabolic disposition of FLN. The effect of dose on FLN kinetics could not be evaluated in this preliminary study.


Assuntos
Epilepsia/tratamento farmacológico , Flunarizina/farmacocinética , Adulto , Carbamazepina/administração & dosagem , Carbamazepina/farmacocinética , Relação Dose-Resposta a Droga , Quimioterapia Combinada , Epilepsia/metabolismo , Feminino , Flunarizina/administração & dosagem , Humanos , Masculino , Fenitoína/administração & dosagem , Fenitoína/farmacocinética
15.
Am Rev Respir Dis ; 130(6): 1125-33, 1984 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-6508009

RESUMO

We compared parameters of maximal expiratory flow with other tests used in the detection of small airways obstruction (SAD) in a canine model of bronchiolitis obliterans. Bronchiolitis was produced by instilling a 1% solution of nitric acid into the airways of 8 dogs (Group N). In 5 control dogs, a normal saline solution was instilled (Group C). Plethysmographic lung volumes, oscillatory airway resistance (RL), and tests for SAD were examined after bronchiolitis was produced. To evaluate peripheral airway function, the single-breath nitrogen washout curve was used to obtain the slope of phase III and to estimate the lung volume at which a terminal increase in N2 concentration was observed (closing capacity). Maximal expiratory flow-volume curves while the dogs breathed air and 80:20 helium:oxygen (HeO2) were performed to obtain the air flow rate at 50% vital capacity (V50), the corresponding HeO2 flow rate (delta Vmax), and the lung volume at which air and HeO2 flow rates were equal (Viso). After injury, the histologic aspects of the lung in Group N showed acute and chronic inflammation of the small airways. The RL did not change in Group N, despite a relative increase in peripheral airway resistance, which when measured increased about 4 times. Compared with Group C, significant increases in closing capacity and Viso and significant decreases in V50 were observed in Group N. Although predicted to decrease in SAD, delta Vmax did not change. We conclude that delta Vmax is relatively insensitive to SAD. Possible mechanisms resulting in reduced V50 but maintained delta Vmax in this model were further examined in terms of the concepts outlined by the wave-speed theory of flow limitation.


Assuntos
Obstrução das Vias Respiratórias/diagnóstico , Bronquite/veterinária , Modelos Animais de Doenças , Doenças do Cão/diagnóstico , Testes de Função Respiratória , Obstrução das Vias Respiratórias/etiologia , Animais , Brônquios/patologia , Bronquite/complicações , Bronquite/patologia , Cães , Curvas de Fluxo-Volume Expiratório Máximo
16.
Am J Orthod ; 79(3): 250-62, 1981 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-6938135

RESUMO

Some major theories concerning the etiology of malocclusion and its modern increase in frequency include genetic explanations, such as inbreeding, racial crossing, and accumulation of mutations, as well as such environmental causes as "habits," allergies, and caries causing reduced arch space of premature deciduous tooth loss. Reduction of masticatory stress resulting from modern urbanism is less often considered as an agent. Many examples of acquisition of gross malocclusion in aboriginal peoples immediately following dietary "modernization" contradict the genetic explanations. A rural population from central Kentucky presents several propitious social characteristics for epidemiologic study of occlusion. They have experienced almost no professional dental care, they are highly inbred (but less so during the last 30 years), and their diet included many difficult-to-chew foods until the recent introduction of industry to the area. Occlusion was evaluated according to the criteria of the Treatment Priority Index. The temporal change and correlates of occlusal variation were assessed on wax-bite impressions of thirty-four persons, informant dietary histories, and other information. The older inhabitants raised on more traditional diets show significantly better occlusion. Dietary consistency provides the most powerful explanation for the transition in occlusal variation, through it was not conclusive in these data.


Assuntos
Má Oclusão/etiologia , População Rural , Adolescente , Adulto , Fatores Etários , Criança , Arco Dental/anatomia & histologia , Dieta , Humanos , Kentucky , Pessoa de Meia-Idade
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