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1.
J Technol Transf ; : 1-29, 2023 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-36816884

RESUMEN

While previous entrepreneurship research has only seldom drawn on organizational ambidexterity, the analysis of the important contemporary tensions among entrepreneurship, innovation management and strategic management issues may be facilitated by more closely analysing organizational ambidexterity in entrepreneurial settings. In this paper, we follow this thinking and more closely analyse an often applied form of corporate entrepreneurship: automation. Such automation is transferring work that was formerly conducted by humans to machines and may thus result in new tensions between corporate entrepreneurship, innovation management and the management of organizational stakeholders such as employees. The present paper investigates whether increased automation lowers the stability of firms' relationships with their employees. In addition, we expect that this relationship is moderated by organizational ambidexterity, as employees may have perceived ambidexterity as a signal that their firm will not overly invest in exploitation only, but maintain a balance between exploitation and exploration. Drawing on stakeholder theory, previous insights into corporate entrepreneurship and a survey of German Mittelstand firms, our findings show that highly ambidextrous firms are indeed more vulnerable to automation, leading to lower employee relational stability. Our findings thus suggest that in highly ambidextrous firms, novel tensions around automation-related corporate entrepreneurship will be detrimental to the stability of the firm's relations with one of its key stakeholder groups: employees.

2.
Technol Forecast Soc Change ; 186: 122135, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36339291

RESUMEN

While stressing the relevance of context, the organizational resilience literature has so far not extensively examined resilience in times of healthcare crises such as the ongoing COVID-19 pandemic. The Parasite Stress Theory of Values suggests that such pandemic crises have detrimental impacts on entrepreneurial activity due to social distancing and its effects on interaction, collaboration, and innovation. However, alternatives to personal contact now available thanks to digitalization, have not yet been examined. We expect entrepreneurial firms with more digitalized business models to show higher resilience to pandemic crises, especially those highly affected by globalization and more for non-family businesses than for family businesses. Based on a survey of German Mittelstand firms in the midst of the crisis induced by COVID-19, our findings broadly support our expectations and thus help qualify the Parasite Stress Theory of Values and contribute to a better understanding of organizational resilience in times of pandemic crises.

3.
Nano Lett ; 19(6): 3863-3870, 2019 06 12.
Artículo en Inglés | MEDLINE | ID: mdl-31035764

RESUMEN

The crystal polarity of noncentrosymmetric wurtzite GaN nanowires is determined nondestructively in the scanning electron microscope using electron backscatter diffraction (EBSD). The impact of the nanowire polarity on light emission is then investigated using cathodoluminescence (CL) spectroscopy. EBSD can determine polarity of noncentrosymmetric crystals by interrogating differences in the intensity distribution of bands of the EBSD pattern associated with semipolar planes. Experimental EBSD patterns from an array of GaN nanowires are compared with theoretical patterns produced using dynamical electron simulations to reveal whether they are Ga- or N-polar or, as in several cases, of mixed polarity. CL spectroscopy demonstrates the effect of the polarity on light emission, with spectra obtained from nanowires of known polarity revealing a small but measurable shift (≈28 meV) in the GaN near band edge emission energy between those with Ga and N polarity. We attributed this energy shift to a difference in impurity incorporation in nanowires of different crystal polarity. This approach can be employed to nondestructively identify polarity in a wide range of noncentrosymmetric nanoscale material systems and provide direct comparison with their luminescence.

4.
Proc Biol Sci ; 285(1870)2018 01 10.
Artículo en Inglés | MEDLINE | ID: mdl-29298934

RESUMEN

Multi-omic approaches promise to supply the power to detect genes underlying disease and fitness-related phenotypes. Optimal use of the resulting profusion of data requires detailed investigation of individual candidate genes, a challenging proposition. Here, we combine transcriptomic and genomic data with molecular modelling of candidate enzymes to characterize the evolutionary history and function of the serine protease cocoonase. Heliconius butterflies possess the unique ability to feed on pollen; recent work has identified cocoonase as a candidate gene in pollen digestion. Cocoonase was first described in moths, where it aids in eclosure from the cocoon and is present as a single copy gene. In heliconiine butterflies it is duplicated and highly expressed in the mouthparts of adults. At least six copies of cocoonase are present in Heliconius melpomene and copy number varies across H. melpomene sub-populations. Most cocoonase genes are under purifying selection, however branch-site analyses suggest cocoonase 3 genes may have evolved under episodic diversifying selection. Molecular modelling of cocoonase proteins and examination of their predicted structures revealed that the active site region of each type has a similar structure to trypsin, with the same predicted substrate specificity across types. Variation among heliconiine cocoonases instead lies in the outward-facing residues involved in solvent interaction. Thus, the neofunctionalization of cocoonase duplicates appears to have resulted from the need for these serine proteases to operate in diverse biochemical environments. We suggest that cocoonase may have played a buffering role in feeding during the diversification of Heliconius across the neotropics by enabling these butterflies to digest protein from a range of biochemical milieux.


Asunto(s)
Mariposas Diurnas/enzimología , Evolución Molecular , Genes de Insecto/genética , Proteínas de Insectos/genética , Serina Proteasas/genética , Animales , Mariposas Diurnas/genética , Dominio Catalítico , Proteínas de Insectos/química , Proteínas de Insectos/metabolismo , Modelos Moleculares , Filogenia , Néctar de las Plantas/metabolismo , Polen/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Serina Proteasas/química , Serina Proteasas/metabolismo , Especificidad por Sustrato , Transcriptoma
5.
Lupus ; 26(8): 825-834, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27852935

RESUMEN

Blood-borne RNA circulating in association with autoantibodies is a potent stimulator of interferon production and immune system activation. RSLV-132 is a novel fully human biologic Fc fusion protein that is comprised of human RNase fused to the Fc domain of human IgG1. The drug is designed to remain in circulation and digest extracellular RNA with the aim of preventing activation of the immune system via Toll-like receptors and the interferon pathway. The present study describes the first clinical study of nuclease therapy in 32 subjects with systemic lupus erythematosus. The drug was well tolerated with a very favorable safety profile. The approximately 19-day serum half-life potentially supports once monthly dosing. There were no subjects in the study that developed anti-RSLV-132 antibodies. Decreases in B-cell activating factor correlated with decreases in disease activity in a subset of patients.


Asunto(s)
Autoanticuerpos/sangre , Lupus Eritematoso Sistémico/tratamiento farmacológico , ARN/sangre , Proteínas Recombinantes de Fusión/uso terapéutico , Adulto , Autoanticuerpos/inmunología , Factor Activador de Células B/metabolismo , Método Doble Ciego , Esquema de Medicación , Femenino , Semivida , Humanos , Inmunoglobulina G/inmunología , Lupus Eritematoso Sistémico/inmunología , Masculino , Persona de Mediana Edad , Proteínas Recombinantes de Fusión/administración & dosificación , Proteínas Recombinantes de Fusión/efectos adversos , Ribonucleasas/inmunología , Índice de Severidad de la Enfermedad
6.
Resuscitation ; 184: 109708, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36709825

RESUMEN

INTRODUCTION: The International Commission for Mountain Emergency Medicine (ICAR MedCom) developed updated recommendations for the management of avalanche victims. METHODS: ICAR MedCom created Population Intervention Comparator Outcome (PICO) questions and conducted a scoping review of the literature. We evaluated and graded the evidence using the American College of Chest Physicians system. RESULTS: We included 120 studies including original data in the qualitative synthesis. There were 45 retrospective studies (38%), 44 case reports or case series (37%), and 18 prospective studies on volunteers (15%). The main cause of death from avalanche burial was asphyxia (range of all studies 65-100%). Trauma was the second most common cause of death (5-29%). Hypothermia accounted for few deaths (0-4%). CONCLUSIONS AND RECOMMENDATIONS: For a victim with a burial time ≤ 60 minutes without signs of life, presume asphyxia and provide rescue breaths as soon as possible, regardless of airway patency. For a victim with a burial time > 60 minutes, no signs of life but a patent airway or airway with unknown patency, presume that a primary hypothermic CA has occurred and initiate cardiopulmonary resuscitation (CPR) unless temperature can be measured to rule out hypothermic cardiac arrest. For a victim buried > 60 minutes without signs of life and with an obstructed airway, if core temperature cannot be measured, rescuers can presume asphyxia-induced CA, and should not initiate CPR. If core temperature can be measured, for a victim without signs of life, with a patent airway, and with a core temperature < 30 °C attempt resuscitation, regardless of burial duration.


Asunto(s)
Avalanchas , Reanimación Cardiopulmonar , Hipotermia , Humanos , Complejo Hierro-Dextran , Asfixia/terapia , Estudios Retrospectivos , Estudios Prospectivos , Hipotermia/terapia
7.
Ultramicroscopy ; 213: 112977, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32361281

RESUMEN

Understanding defects and their roles in plastic deformation and device reliability is important for the development of a wide range of novel materials for the next generation of electronic and optoelectronic devices. We introduce the use of gaseous secondary electron detectors in a variable pressure scanning electron microscope for non-destructive imaging of extended defects using electron channelling contrast imaging. We demonstrate that all scattered electrons, including the secondary electrons, can provide diffraction contrast as long as the sample is positioned appropriately with respect to the incident electron beam. Extracting diffraction information through monitoring the modulation of the intensity of secondary electrons as a result of diffraction of the incident electron beam, opens up the possibility of performing low energy electron channelling contrast imaging to characterise low atomic weight and ultra-thin film materials. Our methodology can be adopted for large area, nanoscale structural characterisation of a wide range of crystalline materials including metals and semiconductors, and we illustrate this using the examples of aluminium nitride and gallium nitride. The capability of performing electron channelling contrast imaging, using the variable pressure mode, extends the application of this technique to insulators, which usually require conducting coatings on the sample surface for traditional scanning electron microscope based microstructural characterisation.

8.
Sci Rep ; 10(1): 12650, 2020 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-32724185

RESUMEN

It is well-known that it is crucial to insert either a single InGaN underlayer or an InGaN superlattice (SLS) structure (both with low InN content) as a pre-layer prior to the growth of InGaN/GaN multiple quantum wells (MQWs) served as an active region for a light-emitting diode (LED). So far, this growth scheme has achieved a great success in the growth of III-nitride LEDs on c-plane substrates, but has not yet been applied in the growth of any other orientated III-nitride LEDs. In this paper, we have applied this growth scheme in the growth of semi-polar (11-22) green LEDs, and have investigated the impact of the SLS pre-layer on the optical performance of semi-polar (11-22) green LEDs grown on patterned (113) silicon substrates. Our results demonstrate that the semi-polar LEDs with the SLS pre-layer exhibit an improvement in both internal quantum efficiency and light output, which is similar to their c-plane counterparts. However, the performance improvement is not so significant as in the c-plane case. This is because the SLS pre-layer also introduces extra misfit dislocations for the semi-polar, but not the c-plane case, which act as non-radiative recombination centres.

9.
Sci Rep ; 9(1): 986, 2019 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-30700776

RESUMEN

A novel overgrowth approach has been developed in order to create a multiple-facet structure consisting of only non-polar and semi-polar GaN facets without involving any c-plane facets, allowing the major drawbacks of utilising c-plane GaN for the growth of III-nitride optoelectronics to be eliminated. Such a multiple-facet structure can be achieved by means of overgrowth on non-polar GaN micro-rod arrays on r-plane sapphire. InGaN multiple quantum wells (MQWs) are then grown on the multiple-facet templates. Due to the different efficiencies of indium incorporation on non-polar and semi-polar GaN facets, multiple-colour InGaN/GaN MQWs have been obtained. Photoluminescence (PL) measurements have demonstrated that the multiple-colour emissions with a tunable intensity ratio of different wavelength emissions can be achieved simply through controlling the overgrowth conditions. Detailed cathodoluminescence measurements and excitation-power dependent PL measurements have been performed, further validating the approach of employing the multiple facet templates for the growth of multiple colour InGaN/GaN MQWs. It is worth highlighting that the approach potentially paves the way for the growth of monolithic phosphor-free white emitters in the future.

10.
J Trauma ; 63(4): 875-83, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18090020

RESUMEN

BACKGROUND: We wished to determine the characteristics of patients with pelvic ring fractures (PGs) in England and Wales, make comparisons to major trauma patients without pelvic injury (NPGs), and determine factors predicting mortality, including the impact of presence of pelvic reconstruction facilities in the receiving hospitals on outcome. METHODS: Prospective data from 106 trauma receiving hospitals forming the Trauma Audit and Research Network were studied. Between January 1989 and December 2001 data of 159,746 trauma patients were collected in the Trauma Audit and Research Network database. Because of incomplete data, 1,610 pelvic fracture patients and 13,499 patients without pelvic fracture were excluded from detailed analysis. In total, 11,149 patients in the PG and the remaining 133,486 patients in the NPG (control) group were included in the final analysis. RESULTS: There were statistically significantly more patients with an Injury Severity Score >15 in the PG group (n = 3,576; 32.1%) than in NPG group (n = 19,238; 14.4%) (p < 0.001), indicating that pelvic injuries were more often associated with other injuries. The majority of patients sustained Abbreviated Injury Score (AIS) 2 pelvic injuries (65.0%), whereas AIS 4 and 5 injuries were found in less than 10% of patients. Pelvic ring injuries were most commonly associated with chest trauma with >AIS 2 severity in 21.2% of the patients, head injuries (>AIS 2) in 16.9%, liver or spleen injuries in 8.0%, and two or more long bone fractures in 7.8%. The 3-month cumulative mortality rate of the patients with pelvic injuries was 14.2% (1,586 patients) versus 5.6% (7,465 patients) of the NPG group. CONCLUSION: Age, early physiologic derangement, and presence of other injuries (head or trunk) were associated with reduced survival rates. When the expertise to deal with such a group of patients is not available, early transfer under safe conditions should be considered to improve survival rates.


Asunto(s)
Fracturas Óseas/epidemiología , Huesos Pélvicos/lesiones , Adulto , Distribución por Edad , Causalidad , Comorbilidad , Femenino , Fracturas Óseas/terapia , Humanos , Incidencia , Puntaje de Gravedad del Traumatismo , Unidades de Cuidados Intensivos/estadística & datos numéricos , Tiempo de Internación/estadística & datos numéricos , Masculino , Traumatismo Múltiple/epidemiología , Ortopedia/estadística & datos numéricos , Evaluación de Procesos y Resultados en Atención de Salud , Prevalencia , Estudios Prospectivos , Análisis de Regresión , Distribución por Sexo , Análisis de Supervivencia , Reino Unido/epidemiología
11.
Rev Sci Instrum ; 78(3): 035115, 2007 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17411225

RESUMEN

Shimming systems are required to provide sufficient field homogeneity for high resolution nuclear magnetic resonance (NMR). In certain specialized applications, such as rotating-field NMR and mobile ex situ NMR, permanent magnet-based shimming systems can provide considerable advantages. We present a simple two-dimensional shimming method based on harmonic corrector rings which can provide arbitrary multipole order shimming corrections. Results demonstrate, for example, that quadrupolar order shimming improves the linewidth by up to an order of magnitude. An additional order of magnitude reduction is in principle achievable by utilizing this shimming method for z-gradient correction and higher order xy gradients.

12.
Nanoscale ; 8(21): 11019-26, 2016 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-27174084

RESUMEN

We report a method of growing site controlled InGaN multiple quantum discs (QDs) at uniform wafer scale on coalescence free ultra-high density (>80%) nanorod templates by metal organic chemical vapour deposition (MOCVD). The dislocation and coalescence free nature of the GaN space filling nanorod arrays eliminates the well-known emission problems seen in InGaN based visible light sources that these types of crystallographic defects cause. Correlative scanning transmission electron microscopy (STEM), energy-dispersive X-ray (EDX) mapping and cathodoluminescence (CL) hyperspectral imaging illustrates the controlled site selection of the red, yellow and green (RYG) emission at these nano tips. This article reveals that the nanorod tips' broad emission in the RYG visible range is in fact achieved by manipulating the InGaN QD's confinement dimensions, rather than significantly increasing the In%. This article details the easily controlled method of manipulating the QDs dimensions producing high crystal quality InGaN without complicated growth conditions needed for strain relaxation and alloy compositional changes seen for bulk planar GaN templates.

13.
Nanoscale ; 8(27): 13521, 2016 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-27353692

RESUMEN

Correction for 'Site controlled red-yellow-green light emitting InGaN quantum discs on nano-tipped GaN rods' by M. Conroy et al., Nanoscale, 2016, 8, 11019-11026.

14.
Sci Rep ; 6: 19087, 2016 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-26750455

RESUMEN

The Faraday effect is a representative magneto-optical phenomenon, resulting from the transfer of angular momentum between interacting light and matter in which time-reversal symmetry has been broken by an externally applied magnetic field. Here we report on the Faraday rotation induced in the prominent 3D topological insulator Bi2Se3 due to bulk interband excitations. The origin of this non-resonant effect, extraordinarily strong among other non-magnetic materials, is traced back to the specific Dirac-type Hamiltonian for Bi2Se3, which implies that electrons and holes in this material closely resemble relativistic particles with a non-zero rest mass.

15.
Am J Cardiol ; 84(2): 208-13, 1999 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-10426342

RESUMEN

Quantitative 3-dimensional (3-D) echocardiography provides accurate assessment of left ventricular (LV) volume, shape, and function, but depends on manual endocardial border tracing. This study determined the minimal number of borders that need to be traced to obtain an accurate analysis of not only the volume of the left ventricle but also its shape, using the integrated methods for quantitative 3-D echocardiography developed by our laboratory. Transthoracic 3-D echocardiographic studies were obtained in 9 normal subjects and 6 patients with heart disease by freehand scanning. The LV endocardium was manually traced in 17 +/- 5 imaging planes and reconstructed in 3 dimensions. The volume and shape of each reconstruction were compared with values measured from surfaces reconstructed from 8 subsets containing 2 to 7 borders; each subset was acquired from different combinations of spatially distributed parasternal and apical views. Accurate measurements were obtained from data sets having > or = 5 borders, regardless of whether the image planes were predominantly apical or parasternal views. In conclusion, the LV border should be traced in > or = 5 imaging planes to obtain accurate measurements of volume and shape. The piece-wise smooth reconstruction method and freehand scanning using a magnetic field tracing system allow the borders to be acquired from whatever combination of acoustic windows and views provides optimal image quality.


Asunto(s)
Ecocardiografía/métodos , Ventrículos Cardíacos/diagnóstico por imagen , Adulto , Femenino , Ventrículos Cardíacos/patología , Humanos , Masculino , Persona de Mediana Edad , Volumen Sistólico
16.
J Endocrinol ; 108(1): 63-8, 1986 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-3003222

RESUMEN

In an investigation of the factors leading to the increase in the concentration of plasma free glucocorticoid, which results in immunosuppression and death after mating of all males in natural populations of a small shrew-like marsupial, the dusky antechinus (Antechinus swainsonii), the integrity of the glucocorticoid feedback control of the concentration of plasma cortisol was examined by use of dexamethasone-suppression tests. Injection of 0.2 mg dexamethasone/kg i.m. caused a marked fall in the concentration of plasma cortisol 17 h later, approximately 2 months and 2 weeks before the annual mating period in mid-July. However, the same dose had no significant effect on the increased concentration of plasma cortisol characteristic of the mid- to late July mating period. Injection of 100 i.u. ACTH/kg i.m. caused a significant increase in the concentration of plasma cortisol 6-7 h later on all occasions, indicating that the responsiveness of the adrenal cortex to ACTH did not change. Pretreatment with dexamethasone had no effect on the ACTH-stimulated cortisol concentration, ruling out a possible direct effect of dexamethasone on adrenocortical secretion in this species. Dexamethasone also reduced the concentration of plasma testosterone when the level was low, before the mating period, but not when the level was high, at the beginning of the mating period. It is concluded that, in association with a rapid increase in the concentration of plasma testosterone, an increase in aggression and intense mating activity, glucocorticoid feedback control of ACTH secretion is impaired.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Hidrocortisona/sangre , Marsupiales/sangre , Conducta Sexual Animal , Corticoesteroides/sangre , Glándulas Suprarrenales/efectos de los fármacos , Hormona Adrenocorticotrópica/farmacología , Animales , Dexametasona/farmacología , Retroalimentación , Hidrocortisona/metabolismo , Masculino , Testosterona/sangre
17.
Mayo Clin Proc ; 66(9): 892-8, 1991 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-1921498

RESUMEN

We investigated the relationship between use of L-tryptophan and development of eosinophilic fasciitis by two methods: a retrospective patient survey and a case-control study of patients with eosinophilic fasciitis diagnosed at the Mayo Clinic between 1977 and 1989. Before 1986, no traceable patients with eosinophilic fasciitis had taken L-tryptophan. Between Jan. 1, 1986, and July 31, 1989, 8 of 34 patients had ingested L-tryptophan (P less than 0.001). In the case-control study, traceable patients with eosinophilic fasciitis were matched with patients who had systemic sclerosis or rheumatoid arthritis and healthy control subjects who had undergone a general medical examination. Of the 60 matched control subjects, 2 had used L-tryptophan. Thus, the odds ratio was 19, indicating a 19-fold greater likelihood of use of L-tryptophan in patients with eosinophilic fasciitis than in the control group. A retrospective assessment of clinical features, response to treatment, and blinded review of biopsy specimens of skin and fascia in patients who had eosinophilic fasciitis with or without exposure to L-tryptophan disclosed no significant differences in the two groups. This retrospective study confirms a strong association between consumption of L-tryptophan and development of eosinophilic fasciitis in some patients. No clinical or histopathologic features were detected that distinguished this disorder on the basis of previous exposure to L-tryptophan.


Asunto(s)
Eosinofilia/inducido químicamente , Fascitis/inducido químicamente , Triptófano/efectos adversos , Adulto , Biopsia , Estudios de Casos y Controles , Eosinofilia/epidemiología , Eosinofilia/patología , Fascitis/epidemiología , Fascitis/patología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Estudios Retrospectivos
18.
Obstet Gynecol ; 88(1): 119-22, 1996 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-8684743

RESUMEN

OBJECTIVE: To determine the anesthetic and surgical morbidity associated with postpartum tubal ligation after pregnancy complicated by pregnancy-induced hypertension. METHODS: Preoperative hemodynamic measurements, laboratory results, choice of anesthetic technique, intraoperative hemodynamic changes, and postoperative morbidity were compared in 53 women with pregnancy-induced hypertension (hypertensive group) and 53 controls who underwent postpartum tubal ligation between October 1992 and November 1995. We used a retrospective case-control design. RESULTS: Preoperative mean blood pressure (BP) measurements ( +/- standard deviation) were greater in hypertensive women than in controls (158 +/- 22/91 +/- 12 versus 126 +/- 13/71 +/- 10 mmHg; P < .001). Among women given spinal anesthetics for tubal ligation, the minimum intraoperative systolic BP was significantly lower in controls than in hypertensive women (P < .05). However, the maximum percentage decrease in systolic BP was greater in hypertensive women than in controls (33 +/- 14 versus 22 +/- 10%; P < .05). Only one patient in each group developed intraoperative hypertension. The percentage of patients discharged later than the first postoperative day was greater in hypertensive women than in controls (23 versus 8%; P < .05). CONCLUSION: The lack of profound hemodynamic responses during spinal or general anesthesia for postpartum tubal ligation supports the continued use of this procedure in selected women with pregnancy-induced hypertension.


Asunto(s)
Hipertensión , Periodo Posparto , Preeclampsia , Complicaciones Cardiovasculares del Embarazo , Esterilización Tubaria , Femenino , Humanos , Embarazo , Complicaciones Cardiovasculares del Embarazo/fisiopatología
19.
Obstet Gynecol ; 76(1 Suppl): 60S-62S, 1990 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-2359582

RESUMEN

Ambulatory tocodynamometry has been used for some time to record uterine activity during pregnancy. Most studies, however, have been performed in the third trimester (more than 24 weeks). The current study was initiated to assess uterine activity at earlier gestational ages. One hundred thirty-seven patients were studied between 14-19 weeks' gestation (inclusive). Seven patients who were being monitored were noted to have preterm labor, and six of these seven were found to have increased uterine activity before the diagnosis of preterm labor. There was no difficulty encountered in the vast majority of cases in recording objective, accurate uterine activity information even at these early gestational ages. There was an increase in the uterine activity (during the 18th and 19th weeks) in patients destined to develop preterm labor later in gestation as compared with the contraction pattern of those who labored at term. This study demonstrates that accurate uterine activity information can be gained at these early gestational ages and that when increased contraction frequency is present, it is related to preterm labor.


Asunto(s)
Trabajo de Parto Prematuro/fisiopatología , Contracción Uterina/fisiología , Adulto , Cardiotocografía , Femenino , Humanos , Trabajo de Parto Prematuro/etiología , Embarazo , Primer Trimestre del Embarazo , Segundo Trimestre del Embarazo , Factores de Riesgo
20.
Obstet Gynecol ; 76(1 Suppl): 76S-81S, 1990 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-2113663

RESUMEN

It has been shown that an intensive system of preterm birth prevention using home uterine activity monitoring can decrease the number of early births. Such a system was employed in 130 public assistance (Medicaid) patients who were at high risk for preterm birth. A retrospective review of the pregnancy outcome in these subjects was conducted and their data exposed to a model for projected patient care cost. The incidence of preterm labor in the at-risk group was 46%, with an average prolongation of pregnancy of 4.9 weeks. The occurrence of preterm delivery for failed tocolysis or advanced cervical dilatation was less than 10%. Based on a cost-analysis model that considered newborn charges and monitoring expenses, nearly [corrected] $3 million (an average of $21,813 [corrected] per patient) was saved using this system.


Asunto(s)
Medicaid/economía , Monitoreo Fisiológico/economía , Trabajo de Parto Prematuro/economía , Contracción Uterina/fisiología , Análisis Costo-Beneficio , Costos y Análisis de Costo , Femenino , Edad Gestacional , Humanos , Incidencia , Tiempo de Internación/economía , Michigan , Mississippi , Trabajo de Parto Prematuro/epidemiología , Trabajo de Parto Prematuro/prevención & control , Embarazo , Estudios Retrospectivos , Factores de Riesgo , Factores Socioeconómicos , Estados Unidos
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