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1.
Radiol Case Rep ; 14(8): 946-951, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31193859

RESUMEN

The concurrence of wandering spleen, organoaxial gastric volvulus, and pancreatic volvulus is very rare. They have been associated with symptoms such as severe abdominal pain, abdominal distention, and vomiting. However, the diagnosis remains complicated and any delay can result in ischemia and necrosis of the organs involved. In this case presentation, we present a unique case involving a 14-year-old girl who presented initially with acute abdominal pain. Assessment with enhanced computed tomography scan led to the diagnosis of wandering spleen, organoaxial gastric volvulus, and pancreatic volvulus, in addition to cholestasis, making it the first study to report on the simultaneous occurrence of this triad and cholestasis.

2.
Crop Sci ; 58(6): 2399-2412, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-33343015

RESUMEN

Drought is a key maize (Zea mays L.) production constraint in sub-Saharan Africa. Fourteen, fifteen, and twenty-five extra-early maturing maize cultivars, with varying Striga resistance and drought and low soil N tolerance, were developed from 1995 to 2000 (Period 1), 2001 to 2006 (Period 2), and 2007 to 2012 (Period 3), respectively. The objectives of this study were to examine yield gains in the cultivars and to investigate inter-trait relationships and yield stability under six drought and 17 rainfed conditions in West Africa from 2013 to 2016. Annual rate of yield increase across cultivars was 0.034 (3.28%) and 0.068 Mg ha-1 (2.25%), whereas yield gains per period were 0.17 and 0.38 Mg ha-1 under drought and rainfed environments, respectively. Yield gains under drought and rainfed environments were related to prolonged flowering period, increased plant and ear heights, improved stalk lodging, and ear and plant aspects, whereas delayed leaf senescence and increased number of ears per plant accompanied yield improvement under drought only. Ear aspect and number of ears per plant were primary contributors to yield and could be used as selection criteria for yield enhancement under drought and rainfed conditions. High-yielding and stable cultivars across all environments based on additive main effects and multiplicative interaction (AMMI) biplot included '2004 TZEE-Y Pop STR C4' and 'TZEE-W Pop STR BC2 C0' of Period 2 and '2009 TZEE-W STR', 'TZEE-Y STR 106', 'TZEE-W STR 107', and 'TZEE-W DT C0 STR C5' of Period 3. These cultivars could be commercialized to improve food self-sufficiency in sub-Saharan Africa.

4.
Nanotechnology ; 25(40): 405702, 2014 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-25213380

RESUMEN

We report on the effects of substrate, starting material, and temperature on the growth of MoS(2) atomic layers by thermal vapor sulfurization in a tube-furnace system. With Mo as the starting material, atomic layers of MoS(2) flakes are obtained on sapphire substrates while a bell-shaped MoS(2) layer, sandwiched by amorphous SiO(2), is obtained on native-SiO(2)/Si substrates under the same sulfurization conditions. An anomalous thickness-dependent Raman shift (A(1g)) of the MoS(2) atomic layers is observed in Mo-sulfurizations on sapphire substrates, which can be attributed to the competition between the effects of thickness and the surface/interface. Both effects vary with the sulfurizing temperatures for a certain initial Mo thickness. The anomalous frequency trend of A(1g) is missing when using MoO(3) instead of Mo as the starting material. In this case, the lateral growth of MoS(2) on sapphire is also largely improved. Furthermore, the area density of the resultant MoS(2) atomic layers is significantly increased by increasing the deposition temperature of the starting MoO(3) to 700 °C; the adjacent ultrathin MoS(2) grains coalesce in one or other direction, forming connected chains in wafer scale. The thickness of the so-obtained MoS(2) is generally controlled by the thickness of the starting material; however, the structural and morphological properties of MoS(2) grains, towards large area and continuous atomic layers, are strongly dependent on the temperature of the initial material deposition, and on the temperature of sulfurization, because of the competition between surface mobility and atom evaporation.

5.
ACS Appl Mater Interfaces ; 6(5): 3501-7, 2014 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-24397590

RESUMEN

We report on synthesis and properties of p-type Ga2S3 semiconductor thin films that were prepared by sulfurizing epiready n-type GaAs (111) surface at elevated temperatures. Comparisons of structural and optical properties among the thin films, peeling-off resulted microtubes, and the remains after peeling-off give a clear clue to the crystal growth and phase evolutions of Ga2S3. Three layers of Ga2S3 are clearly identified in the thin films. They are layer i, cubic Ga2S3 epitaxially grown on the GaAs (111) substrate; layer ii, polycrystalline cubic Ga2S3 on top of layer-i; and layer iii, monoclinic and/or hexagonal Ga2S3 on top of layer ii. The onset of peeling-off occurred in layer i and/or at the interface between layer i and ii. Both the phase evolutions and the location of peeling-off are associated with a Ga out diffusion growth mechanism. Absorption spectroscopy revealed a direct bandgap of 3.0 eV, whereas photoluminescence spectra showed defects (excited Ga vacancies) related red (1.62 eV) and green (2.24 eV) emissions of the Ga2S3 films; both are qualitatively consistent with those reported values obtained at lower sample temperatures from Ga2S3 single crystals. These results, together with a large on/off current ratio (i.e., ∼14 at a bias of 4.0 V) of the resultant hetero p-Ga2S3/n-GaAs junction under a blue laser (405 nm, 3.0 mW) illumination, shed light on consequent integrations of Ga2S3- and GaAs-based optoelectronic devices, e.g., high-power laser radiation sensors.

6.
Nanoscale ; 6(1): 624-9, 2014 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-24253383

RESUMEN

Atomically thin Mo(1-x)W(x)S2 (0 ≤ x ≤ 1) ternary compounds have been grown on 2-inch c-plane sapphire substrates with high uniformity by sulfurizing thin Mo(1-x)W(x) layers that were deposited at room temperature using a co-sputtering technique. Atomic force microscopy (AFM), Raman scattering, and optical absorbance spectroscopy (OAS) studies reveal that the Mo(1-x)W(x)S2 films consist of crystallites of two-to-four monolayers in thickness. X-ray photoelectron spectroscopy (XPS) shows that the core levels of Mo3d and W4f shift to lower binding energies while that of S2p shifts to higher ones with the increase in W compositions, which can be related to the larger electron affinity of W (0.8163 eV) than that of Mo (0.7473 eV). OAS has also shown that the direct bandgap of Mo(1-x)W(x)S2 is tuned from 1.85 to 1.99 eV by increasing x from 0 to 1. Both E(1/2)(g) and A(1g) phonon modes of the Mo(1-x)W(x)S2 films exhibit a two-mode behavior. The bandgap tuning and the two-mode phonon behaviors are typically the same as those recently observed in monolayer Mo(1-x)W(x)S2 obtained by mechanical exfoliation, thus shedding light on the bottom-up growth of large-scale two-dimensional Mo(1-x)W(x)S2 ternary alloys.

7.
Ghana Med J ; 45(4): 174-6, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22359424

RESUMEN

Transverse vaginal septum is a rare occurrence. When it co-exists with cervical dysgenesis, it is even rarer. Primary amenorrhea with cyclic pain is one manifestation in post-pubertal women. A case of transverse vaginal septum with vaginal atresia and cervical dysgenesis is presented. Presentation as a huge abdominal mass and severe anaemia posed diagnostic challenges. A two-staged management is described as well as variation in management of the septum. The involvement of the patient in her follow up is also stressed.


Asunto(s)
Dolor Abdominal/etiología , Amenorrea/etiología , Anemia/etiología , Cuello del Útero/anomalías , Vagina/anomalías , Femenino , Humanos , Adulto Joven
8.
Ann Trop Paediatr ; 28(1): 35-43, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18318947

RESUMEN

BACKGROUND: Young infant mortality has remained high and relatively unchanged compared with deaths of older infants. Strategies to reduce infant mortality, however, are mostly targeted at the older child. OBJECTIVES: To describe the clinical profile of sick young infants presenting to a hospital and to define important signs and symptoms that will enable health workers to detect young infants with severe illness requiring hospital admission. METHODS: Young infants aged 0-59 days presenting to a paediatric out-patient clinic were evaluated by a nurse using a standardised list of signs and symptoms. A paediatrician independently evaluated these children and decided whether they needed hospitalisation. RESULTS: A total of 685 young infants were enrolled, 22% of whom were <7 days of age. The commonest reasons for seeking care were jaundice in the 0-6-day group, skin problems in the 7-27-day group and cough in the 28-59-day group. The primary clinical diagnoses for admissions were sepsis in the 0-6- and 7-27-day groups and pneumonia in the 28-59-day group. Clinical signs and symptoms predicting severe illness requiring admission were general (history of fever, difficult feeding, not feeding well and temperature >37.5 degrees C) and respiratory (respiratory rate > or =60/min, severe chest in-drawing). CONCLUSION: General and respiratory signs are important predictors for severe illness in young infants. Training peripheral health workers to recognise these signs and to refer to hospital for further assessment and management might have a significant impact on young infant mortality.


Asunto(s)
Enfermedad Aguda/epidemiología , Enfermedades del Recién Nacido/diagnóstico , Triaje/métodos , Factores de Edad , Enfermedades Gastrointestinales/diagnóstico , Enfermedades Gastrointestinales/epidemiología , Ghana/epidemiología , Hospitalización , Humanos , Lactante , Recién Nacido , Enfermedades del Recién Nacido/epidemiología , Infecciones/diagnóstico , Infecciones/epidemiología , Servicio Ambulatorio en Hospital , Pronóstico , Infecciones del Sistema Respiratorio/diagnóstico , Infecciones del Sistema Respiratorio/epidemiología , Enfermedades de la Piel/diagnóstico , Enfermedades de la Piel/epidemiología , Triaje/normas
9.
Clin Exp Immunol ; 144(3): 392-400, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16734607

RESUMEN

Vitamin A supplementation reduces child mortality in populations at risk of vitamin A deficiency and may also reduce maternal mortality. One possible explanation for this is that vitamin A deficiency is associated with altered immune function and cytokine dysregulation. Vitamin A deficiency in pregnancy may thus compound the pregnancy-associated bias of cellular immune responses towards Th-2-like responses and exacerbate susceptibility to intracellular pathogens. We assessed mitogen and antigen-induced cytokine responses during pregnancy and lactation in Ghanaian primigravidae receiving either vitamin A supplementation or placebo. This was a double-blind, randomized, placebo-controlled trial of weekly vitamin A supplementation in pregnant and lactating women. Pregnancy compared to postpartum was associated with a suppression of cytokine responses, in particular of the proinflammatory cytokines interferon (IFN)-gamma and tumour necrosis factor (TNF)-alpha. Mitogen-induced TNF-alpha responses were associated with a decreased risk of peripheral parasitaemia during pregnancy. Furthermore, vitamin A supplementation was significantly associated with an increased ratio of mitogen-induced proinflammatory cytokine (IFN-gamma) to anti-inflammatory cytokine (IL-10) during pregnancy and in the postpartum period. The results of this study indicate that suppression of proinflammatory type 1 immune responses and hence immunity to intracellular infections, resulting from the combined effects of pregnancy and vitamin A deficiency, might be ameliorated by vitamin A supplementation.


Asunto(s)
Citocinas/biosíntesis , Lactancia/inmunología , Complicaciones del Embarazo/inmunología , Deficiencia de Vitamina A/inmunología , Vitamina A/inmunología , Método Doble Ciego , Femenino , Humanos , Inmunidad Celular/efectos de los fármacos , Interferón gamma/biosíntesis , Interleucina-10/biosíntesis , Parasitemia/inmunología , Fitohemaglutininas/inmunología , Atención Posnatal/métodos , Embarazo , Complicaciones Parasitarias del Embarazo/inmunología , Complicaciones Parasitarias del Embarazo/prevención & control , Atención Prenatal/métodos , Tuberculina/inmunología , Factor de Necrosis Tumoral alfa/biosíntesis , Vitamina A/sangre , Vitamina A/uso terapéutico
10.
Trans R Soc Trop Med Hyg ; 97(4): 422-8, 2003.
Artículo en Inglés | MEDLINE | ID: mdl-15259472

RESUMEN

The prevalence of chloroquine-resistant Plasmodium falciparum malaria has been increasing in sub-Saharan Africa and parts of South America over the last 2 decades, and has been associated with increased anaemia-associated morbidity and higher mortality rates. Prospectively collected clinical and parasitological data from a multicentre study of 788 children aged 6-59 months with uncomplicated P. falciparum malaria were analysed in order to identify risk factors for chloroquine treatment failure and to assess its impact on anaemia after therapy. The proportion of chloroquine treatment failures (combined early and late treatment failures) was higher in the central-eastern African countries (Tanzania, 53%; Uganda, 80%; Zambia, 57%) and Ecuador (54%) than in Ghana (36%). Using logistic regression, predictors of early treatment failure included younger age, higher baseline temperature, and greater levels of parasitaemia. We conclude that younger age, higher initial temperature, and higher baseline parasitaemia predict early treatment failure and a higher probability of worsening anaemia between admission and days 7 or 14 post-treatment.


Asunto(s)
Anemia/parasitología , Antimaláricos/uso terapéutico , Cloroquina/uso terapéutico , Malaria Falciparum/tratamiento farmacológico , Parasitemia/tratamiento farmacológico , Factores de Edad , Temperatura Corporal , Preescolar , Resistencia a Medicamentos , Femenino , Humanos , Lactante , Modelos Logísticos , Malaria Falciparum/complicaciones , Masculino , Pronóstico , Estudios Prospectivos , Factores de Riesgo , Insuficiencia del Tratamiento
11.
Am J Clin Nutr ; 74(6): 791-5, 2001 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11722961

RESUMEN

BACKGROUND: Standard therapy for anemia in infants is ferrous sulfate drops administered 3 times/d. Adherence to treatment, however, is often poor. One likely reason for poor adherence is the unpleasant side effects associated with drops. OBJECTIVE: The objective was to evaluate the use of a new form of iron and a delivery system to treat anemia in infants that is likely to produce better adherence to treatment. DESIGN: Using a prospective, randomized, controlled design, we studied 557 anemic children aged 6-18 mo (hemoglobin: 70-99 g/L) in rural Ghana. One group received a daily sachet of microencapsulated ferrous fumarate (80 mg elemental Fe) in powder form plus ascorbic acid to be sprinkled onto any complementary food eaten (sprinkles group); a control group received ferrous sulfate drops 3 times/d for 2 mo (total dose: 40 mg elemental Fe). Hemoglobin and serum ferritin concentrations were measured at baseline and at the end of treatment. RESULTS: Successful treatment of anemia (hemoglobin > 100 g/L) occurred in 58% of the sprinkles group and in 56% of the drops group, with minimal side effects in both groups. Geometric mean ferritin concentrations increased significantly in each group from baseline to the end of treatment (P < 0.001). CONCLUSION: Use of ferrous sulfate drops or a single daily dose of microencapsulated ferrous fumarate sprinkles plus ascorbic acid resulted in a similar rate of successful treatment of anemia without side effects. To our knowledge, this is the first demonstration of the use of microencapsulated iron sprinkles to treat anemia. Improved ease of use may favor the use of sprinkles to deliver iron.


Asunto(s)
Anemia Ferropénica/tratamiento farmacológico , Ácido Ascórbico/uso terapéutico , Compuestos Ferrosos/uso terapéutico , Ácido Ascórbico/administración & dosificación , Esquema de Medicación , Composición de Medicamentos , Quimioterapia Combinada , Femenino , Ferritinas/sangre , Compuestos Ferrosos/administración & dosificación , Compuestos Ferrosos/efectos adversos , Ghana , Hemoglobinas/análisis , Humanos , Lactante , Alimentos Infantiles , Masculino , Cooperación del Paciente , Estudios Prospectivos , Población Rural , Destete
12.
Pediatrics ; 108(3): 613-6, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11533326

RESUMEN

OBJECTIVE: Adherence to treatment of iron-deficiency anemia often is poor in both developed and developing countries. The current standard therapy is ferrous sulfate drops (or syrup) administered 3 times daily. It is possible that adherence would improve with a single-dose daily treatment regimen. We compared the use of single versus 3-times-daily ferrous sulfate drops, at the same total iron dose, on treatment of anemia in infants. METHODS: To obtain a large enough cohort of anemic subjects, we performed the study in rural Ghana. Using a prospective, randomized, controlled design, we studied 557 anemic children (age range: 6-24 months; hemoglobin values: 70-99 g/L). One group (n = 280) received ferrous sulfate drops once daily (40 mg elemental iron), and the control group (n = 277) received ferrous sulfate drops 3 times per day (total dose, 40 mg elemental iron). Treatment lasted for 2 months. Hemoglobin and serum ferritin values were measured at baseline and at the end of the study. RESULTS: Successful treatment of anemia (hemoglobin >100 g/L) occurred in 61% of the single-dose and in 56% of the 3-times-daily group. Geometric mean ferritin levels increased significantly in each group from baseline to the final visit. Side effects were minimal and similar between the 2 groups. CONCLUSION: A single versus a 3-times-daily dose of ferrous sulfate drops over 2 months resulted in a similar rate of successful treatment of anemia, without side effects. To our knowledge, this is the first demonstration of the use of a single-dose daily regimen to treat anemia. Although not examined in the current study, use of a single-dose daily regimen may improve adherence to treatment of anemia in infants.


Asunto(s)
Anemia Ferropénica/tratamiento farmacológico , Compuestos Ferrosos/administración & dosificación , Anemia Ferropénica/sangre , Preescolar , Esquema de Medicación , Femenino , Ferritinas/sangre , Hemoglobinas/análisis , Humanos , Lactante , Masculino , Cooperación del Paciente , Estudios Prospectivos
13.
Int J Gynaecol Obstet ; 74(2): 119-30; discussion 131, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11502289

RESUMEN

The objective of the study described is to assess the feasibility and effectiveness of using a criterion-based clinical audit to measure and improve the quality of obstetric care at the district hospital level in developing countries. The focus is on the management of five life-threatening obstetric complications--hemorrhage, eclampsia, genital tract infection, obstructed labor and uterine rupture was audited using a "before and after" design. The five steps of the audit cycle were followed: establish criteria of good quality care; measure current practice (Review I); feedback findings and set targets; take action to change practice; and re-evaluate practice (Review II). Systematic literature review, panel discussions and pilot work led to the development of 31 audit criteria. Review I included 555 life-threatening complications occurring over 66 hospital-months; Review II included 342 complications over 42 hospital-months. Many common areas for improvement were identified across the four hospitals. Agreed mechanisms for achieving these improvements included clinical protocols, reviews of staffing, and training workshops. Some aspects of clinical monitoring, drug use and record keeping improved significantly between Reviews I and II. Criterion-based clinical audit in four typical district hospitals in Ghana and Jamaica is a feasible and acceptable method for quality assurance and appears to have improved the management of life-threatening obstetric complications.


Asunto(s)
Países en Desarrollo , Hospitales de Distrito/normas , Servicios de Salud Materna/normas , Auditoría Médica , Complicaciones del Embarazo/terapia , Adulto , Tratamiento de Urgencia/normas , Estudios de Factibilidad , Femenino , Ghana , Humanos , Jamaica , Embarazo , Complicaciones del Embarazo/mortalidad , Garantía de la Calidad de Atención de Salud , Indicadores de Calidad de la Atención de Salud
14.
Bull World Health Organ ; 79(5): 394-9, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11417034

RESUMEN

OBJECTIVE: To examine the extent to which district health teams could reduce the burden of malaria, a continuing major cause of mortality and morbidity, in a situation where severe resource constraints existed and integrated care was provided. METHODS: Antimalarial drugs were prepackaged into unit doses in an attempt to improve compliance with full courses of chemotherapy. FINDINGS: Compliance improved by approximately 20% in both adults and children. There were 50% reductions in cost to patients, waiting time at dispensaries and drug wastage at facilities. The intervention, which tended to improve both case and drug management at facilities, was well accepted by health staff and did not involve them in additional working time. CONCLUSION: The prepackaging of antimalarials at the district level offers the prospect of improved compliance and a reduction in the spread of resistance.


Asunto(s)
Antimaláricos/economía , Antimaláricos/uso terapéutico , Costos de los Medicamentos , Embalaje de Medicamentos , Malaria Falciparum/tratamiento farmacológico , Cooperación del Paciente , Acetaminofén/economía , Acetaminofén/provisión & distribución , Acetaminofén/uso terapéutico , Adulto , Antimaláricos/provisión & distribución , Niño , Cloroquina/economía , Cloroquina/provisión & distribución , Cloroquina/uso terapéutico , Formas de Dosificación , Ghana/epidemiología , Humanos , Malaria Falciparum/economía , Malaria Falciparum/epidemiología
17.
Bull World Health Organ ; 78(5): 614-20, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-10859855

RESUMEN

Improving the quality of obstetric care is an urgent priority in developing countries, where maternal mortality remains high. The feasibility of criterion-based clinical audit of the assessment and management of five major obstetric complications is being studied in Ghana and Jamaica. In order to establish case definitions and clinical audit criteria, a systematic review of the literature was followed by three expert panel meetings. A modified nominal group technique was used to develop consensus among experts on a final set of case definitions and criteria. Five main obstetric complications were selected and definitions were agreed. The literature review led to the identification of 67 criteria, and the panel meetings resulted in the modification and approval of 37 of these for the next stage of audit. Criterion-based audit, which has been devised and tested primarily in industrialized countries, can be adapted and applied where resources are poorer. The selection of audit criteria for such settings requires local expert opinion to be considered in addition to research evidence, so as to ensure that the criteria are realistic in relation to conditions in the field. Practical methods for achieving this are described in the present paper.


Asunto(s)
Auditoría Médica , Servicio de Ginecología y Obstetricia en Hospital/normas , Calidad de la Atención de Salud , Países en Desarrollo , Femenino , Ghana , Humanos , Jamaica , Pautas de la Práctica en Medicina , Embarazo , Complicaciones del Embarazo/terapia
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