Mental Health Distress and Delayed Contraception Among Older Adolescents and Young Adults.

Background: Symptoms of mental distress increased sharply during the COVID-19 pandemic, especially among older adolescents and young adults. Mental health distress may make it more challenging for young people to seek other needed health care, including contraception. This study explored the association of symptoms of depression, anxiety, and stress with delays in getting a contraceptive method or prescription. Materials and Methods: Data from a supplementary study (May 15, 2020-March 20, 2023) to a cluster randomized trial in 29 sites in Texas and California were used. The diverse study sample included community college students assigned female at birth of ages 18-29 years (n = 1,665 with 7,023 observations over time). We measured the association of depression (CES-D [Center for Epidemiologic Studies Depression Scale]) or anxiety and stress (DASS-21 [Depression Anxiety Stress Scales]) symptoms with delayed contraceptive care-seeking with mixed-effects multivariable regression with random effects for individual and site. We controlled for age and sociodemographic factors important for access to care. Results: Over one-third of participants (35%) reported they delayed getting the contraceptive method they needed. Multivariable regression results showed increased odds of delayed contraceptive care among participants with symptoms of depression (adjusted odds ratio [aOR] 1.58, 95% confidence interval [CI] 1.27-1.96). Likewise, delays were associated with anxiety and stress symptoms (aOR 1.46, 95% CI 1.17-1.82). Adolescents were more likely to delay seeking contraception than young adults (aOR 1.32, 95% CI 1.07-1.63). Conclusions: Results showed a strong association between mental distress and delayed contraception. Interventions are needed to increase contraceptive access for young people delaying care, along with supportive mental health care services, including for adolescents who face elevated odds of delay. ClinicalTrials.gov Identifier: NCT03519685.

Disruption of NIPBL/Scc2 in Cornelia de Lange Syndrome provokes cohesin genome-wide redistribution with an impact in the transcriptome.

Cornelia de Lange syndrome (CdLS) is a rare disease affecting multiple organs and systems during development. Mutations in the cohesin loader, NIPBL/Scc2, were first described and are the most frequent in clinically diagnosed CdLS patients. The molecular mechanisms driving CdLS phenotypes are not understood. In addition to its canonical role in sister chromatid cohesion, cohesin is implicated in the spatial organization of the genome. Here, we investigate the transcriptome of CdLS patient-derived primary fibroblasts and observe the downregulation of genes involved in development and system skeletal organization, providing a link to the developmental alterations and limb abnormalities characteristic of CdLS patients. Genome-wide distribution studies demonstrate a global reduction of NIPBL at the NIPBL-associated high GC content regions in CdLS-derived cells. In addition, cohesin accumulates at NIPBL-occupied sites at CpG islands potentially due to reduced cohesin translocation along chromosomes, and fewer cohesin peaks colocalize with CTCF.

Suministro y demanda de sangre durante la pandemia de COVID-19. Una revisión / Blood supply and demand during the COVID-19 pandemic. A review

Resumen La propagación tan rápida del nuevo coronavirus 2 del síndrome respiratorio agudo grave (SARS-CoV-2), que se informó por primera vez en Wuhan (China) a finales de diciembre de 2019, y produce la enfermedad caracterizada por neumonía llamada enfermedad por coronavirus 2019 (COVID-19), ha causado un impacto significativo en los sistemas de salud en todo el mundo y la interrupción de la vida cotidiana. A finales de junio el número de casos confirmados es de 9,188,362 millones, con más de 474,339 muertes, y aproximadamente 4,937,282 personas recuperadas. Las estrictas medidas para restricción de la movilidad y medidas de distanciamiento social impuestas por los gobiernos, más el miedo y pánico resultado de manera abrumadora entre el público general, ha comprometido de manera importante la sostenibilidad del suministro de sangre segura, el cual se vuelve particularmente desafiante. La demanda de sangre y productos sanguíneos puede disminuir durante una pandemia debido al aplazamiento de cirugías electivas. Medidas como el distanciamiento físico y el bloqueo total de las ciudades, las provincias o países que intentan frenar la propagación de la infección pueden provocar una disminución importante en el suministro y una escasez general de productos sanguíneos. Los hospitales deben contar con un plan de manejo de sangre para emergencias en la planificación de preparación sobre la sostenibilidad y seguridad del suministro de sangre. Esta revisión considera el impacto de la pandemia de COVID-19 en el suministro de sangre y especifica aspectos importantes del manejo de los donantes, y la utilización apropiada de los componentes sanguíneos.

Abstract The rapid spread of the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which was first reported in Wuhan (China) in late December 2019, and produces the disease characterized by pneumonia called coronavirus disease 2019 (COVID-19), has caused a significant impact on health systems worldwide and disruption of daily life; at the end of June the number of confirmed cases is 9,188,362 million with more than 474,339 deaths, and approximately 4,937,282 people recovered. Strict measures to restrict mobility, social distancing measures imposed by governments, plus overwhelming fear and panic among the general public, have significantly compromised the sustainability of the safe blood supply, it becomes particularly challenging. The demand for blood and blood products may decrease during a pandemic due to the postponement of elective surgeries, measures such as physical distancing and the total blockade of cities, provinces or countries that try to stop the spread of the infection can cause a significant decrease in the supply and a general shortage of blood products. Hospitals must have a blood management plan for emergencies in preparedness planning on the sustainability and safety of the blood supply. This review considers the impact of the COVID-19 pandemic on blood supply and specifies important aspects of donor management, and the proper use of blood components.

SIVA-1 regulates apoptosis and synaptic function by modulating XIAP interaction with the death receptor antagonist FAIM-L.

The long isoform of Fas apoptosis inhibitory molecule (FAIM-L) is a neuron-specific death receptor antagonist that modulates apoptotic cell death and mechanisms of neuronal plasticity. FAIM-L exerts its antiapoptotic action by binding to X-linked inhibitor of apoptosis protein (XIAP), an inhibitor of caspases, which are the main effectors of apoptosis. XIAP levels are regulated by the ubiquitin-proteasome pathway. FAIM-L interaction with XIAP prevents the ubiquitination and degradation of the latter, thereby allowing it to inhibit caspase activation. This interaction also modulates non-apoptotic functions of caspases, such as the endocytosis of AMPA receptor (AMPAR) in hippocampal long-term depression (LTD). The molecular mechanism of action exerted by FAIM-L is unclear since the consensus binding motifs are still unknown. Here, we performed a two-hybrid screening to discover novel FAIM-L-interacting proteins. We found a functional interaction of SIVA-1 with FAIM-L. SIVA-1 is a proapoptotic protein that has the capacity to interact with XIAP. We describe how SIVA-1 regulates FAIM-L function by disrupting the interaction of FAIM-L with XIAP, thereby promoting XIAP ubiquitination, caspase-3 activation and neuronal death. Furthermore, we report that SIVA-1 plays a role in receptor internalization in synapses. SIVA-1 is upregulated upon chemical LTD induction, and it modulates AMPAR internalization via non-apoptotic activation of caspases. In summary, our findings uncover SIVA-1 as new functional partner of FAIM-L and demonstrate its role as a regulator of caspase activity in synaptic function.

Cytoplasmic cyclin D1 regulates cell invasion and metastasis through the phosphorylation of paxillin.

Cyclin D1 (Ccnd1) together with its binding partner Cdk4 act as a transcriptional regulator to control cell proliferation and migration, and abnormal Ccnd1·Cdk4 expression promotes tumour growth and metastasis. While different nuclear Ccnd1·Cdk4 targets participating in cell proliferation and tissue development have been identified, little is known about how Ccnd1·Cdk4 controls cell adherence and invasion. Here, we show that the focal adhesion component paxillin is a cytoplasmic substrate of Ccnd1·Cdk4. This complex phosphorylates a fraction of paxillin specifically associated to the cell membrane, and promotes Rac1 activation, thereby triggering membrane ruffling and cell invasion in both normal fibroblasts and tumour cells. Our results demonstrate that localization of Ccnd1·Cdk4 to the cytoplasm does not simply act to restrain cell proliferation, but constitutes a functionally relevant mechanism operating under normal and pathological conditions to control cell adhesion, migration and metastasis through activation of a Ccnd1·Cdk4-paxillin-Rac1 axis.

Characterization of cytoplasmic cyclin D1 as a marker of invasiveness in cancer.

Cyclin D1 (Ccnd1) is a proto-oncogen amplified in many different cancers and nuclear accumulation of Ccnd1 is a characteristic of tumor cells. Ccnd1 activates the transcription of a large set of genes involved in cell cycle progress and proliferation. However, Ccnd1 also targets cytoplasmic proteins involved in the regulation of cell migration and invasion. In this work, we have analyzed by immunohistochemistry the localization of Ccnd1 in endometrial, breast, prostate and colon carcinomas with different types of invasion. The number of cells displaying membranous or cytoplasmic Ccnd1 was significantly higher in peripheral cells than in inner cells in both collective and pushing invasion patterns of endometrial carcinoma, and in collective invasion pattern of colon carcinoma. Also, the cytoplasmic localization of Ccnd1 was higher when tumors infiltrated as single cells, budding or small clusters of cells. To evaluate cytoplasmic function of cyclin D1, we have built a variant (Ccnd1-CAAX) that remains attached to the cell membrane therefore sequestering this cyclin in the cytoplasm. Tumor cells harboring Ccnd1-CAAX showed high levels of invasiveness and metastatic potential compared to those containing the wild type allele of Ccnd1. However, Ccnd1-CAAX expression did not alter proliferative rates of tumor cells. We hypothesize that the role of Ccnd1 in the cytoplasm is mainly associated with the invasive capability of tumor cells. Moreover, we propose that subcellular localization of Ccnd1 is an interesting guideline to measure cancer outcome.

Inventario de referencia de para estudios de erosión de los suelos en la provincia de Cienfuegos, Cuba / reference inventory for the soils erosion studies in Cienfuegos, Cuba

Para la aplicación exitosa de la técnica del en estudios de erosión del suelo es necesario establecer correctamente el inventario de referencia que representa la entrada total de este radionúclido a la superficie terrestre. En tal sentido, se selecciona un sitio que no haya sido perturbado ni por la erosión ni por el depósito, reconocido como sitio de referencia. En la práctica encontrar estos sitios suele ser difícil. El objetivo de esta investigación fue establecer el inventario de referencia de para localidades de la provincia de Cienfuegos. Quedó establecido que el intervalo de confianza del inventario de referencia de es [1082; 1266] , con una confiabilidad del 90% y el coeficiente de variación del inventario de referencia en las localidades investigadas fue de 11%. Estos valores están en correspondencia con los reportados por otros autores para sitios similares. Asimismo, se determinó la dependencia lineal entre los inventarios de y los promedios históricos de las precipitaciones, con un coeficiente de correlación de 0.94. Esta función lineal se podrá utilizar en la estimación de los inventarios de referencia donde sea complejo encontrar sitios de referencia y por el contrario se disponga de suficiente información respecto a las precipitaciones.

For the successful application of the technique in soil erosion studies, it is necessary to establish the reference inventory correctly as it represents the total entrance of this radionuclide into the earth’s surface. In this sense, a site that has not been perturbed neither for the erosion nor for the deposit, is selected as reference site. In practice to find such sites is usually difficult. The objective of this research was to establish the reference inventory of for the studied localities of Cienfuegos province. It was established that the confidence interval at 90% of probability of the reference inventory is [1082; 1266] , and the variation coefficient of the reference inventory in the researched localities was of 11%. These values are in correspondence with those reported by other authors for similar places. Also the lineal dependence between the inventories of and the historical averages of the precipitations was determined, with a correlation coefficient of 0.94. This lineal function will be able to be used to obtain or to confirm the reference inventories from rainfall data.

Cyclin D1 localizes in the cytoplasm of keratinocytes during skin differentiation and regulates cell-matrix adhesion.

The function of Cyclin D1 (CycD1) has been widely studied in the cell nucleus as a regulatory subunit of the cyclin-dependent kinases Cdk4/6 involved in the control of proliferation and development in mammals. CycD1 has been also localized in the cytoplasm, where its function nevertheless is poorly characterized. In this work we have observed that in normal skin as well as in primary cultures of human keratinocytes, cytoplasmic localization of CycD1 correlated with the degree of differentiation of the keratinocyte. In these conditions, CycD1 co-localized in cytoplasmic foci with exocyst components (Sec6) and regulators (RalA), and with ß1 integrin, suggesting a role for CycD1 in the regulation of keratinocyte adhesion during differentiation. Consistent with this hypothesis, CycD1 overexpression increased ß1 integrin recycling and drastically reduced the ability of keratinocytes to adhere to the extracellular matrix. We propose that localization of CycD1 in the cytoplasm during skin differentiation could be related to the changes in detachment ability of keratinocytes committed to differentiation.

Tumor virilizante de células esteroideas del ovario / Virilizing steroid cell tumor of the ovary

Los tumores de células esteroideas representan el 0,1% de los tumores ováricos. Pertenecen al grupo de los tumores del estroma, también llamados de los cordones sexuales. Aunque pueden aparecer a cualquier edad, son más frecuentes en mujeres menopáusicas y con frecuencia se asocian a síndromes endocrinos. El hirsutismo y la virilización son los hallazgos clínicos más significativos. El manejo debe individualizarse en función de la histología, el estadio quirúrgico y el deseo genésico de la mujer. Presentamos el caso de una paciente de 78 años con alopecia e hirsutismo severo, marcado incremento de testosterona y tumoración en ovario derecho de 4cms., informada de tumor de células esteroideas (AU)

Steroid cell tumors account for 0.1% of ovarian tumors and are classified within the group of stromal tumors, also known as sex cord tumors. These neoplasms can appear at any age but are more common in menopausal women and are associated with endocrine syndromes. The most significant clinical findings are hirsutism and virilization. Management should be individualized according to histological findings, surgical stage and the woman's reproductive wishes. We describe a 78-year-old patient with alopecia and severe hirsutism, a marked increase in testosterone and a 4-cm tumor of the right ovary, diagnosed as a steroid cell tumor (AU)

Lesión quística en la pelvis: un caso de útero doble con hemivagina ciega / Congenital cyst in the pelvis: a case of uterine duplicity with blind vagina

Se presenta un caso de útero doble, con hemivagina ciega, hematocolpos y agenesia renal ipsilateral, que debuta en la edad adulta, como una lesión quística en pelvis. Se trata de una anomalía mesonéfrica o wolfiana que induce un inadecuado proceso de fusión y reabsorción de los conductos de Müller durante el desarrollo embrionario y como consecuencia, la presencia de hemivagina ciega y agenesia renal unilateral. Las manifestaciones clínicas de este tipo de anomalías son muy variables, desde pacientes asintomáticas, con buenos resultados obstétricos como el caso que presentamos, hasta mujeres con clínica florida y pronóstico reproductivo nefasto (AU)

We report a case of uterine duplicity with blind hemivagina, hematocolpos and ipsilateral renal agenesis that manifested in adulthood with a cystic lesion in the pelvis. Uterine duplicity is a mesonephric or Wolffian anomaly inducing alterations in the fusion and resorption of the Müllerian duct during embryonic development, resulting in the presence of blind hemivagina and ipsilateral renal agenesis. The clinical manifestations of these anomalies are highly varied and range from asymptomatic patients, with good obstetric outcomes, as in the present case, to women with dramatic symptoms and extremely poor reproductive prognosis (AU)

Metástasis clínicamente silente de un carcinoma lobulillar de mama en un pólipo endometrial / Metastasis of a clinically silent lobular breast carcinoma to an endometrial polyp

Las metástasis del cáncer de mama en útero son raras y generalmente, cuando existen, los ovarios suelen estar afectados como muestra de una enfermedad diseminada. Sólo hay 14 casos descritos de metástasis de un carcinoma de mama en un pólipo endometrial en pacientes tratadas con tamoxifeno. Tanto su evolución, como su pronóstico son inciertos. Presentamos un caso de metástasis en un pólipo endometrial de un carcinoma lobulillar de mama con buena evolución posterior y un período libre de enfermedad de 5 años(AU)

Metastases to uterus from breast cancer are rare, and in most of the cases the ovaries are also involved. Metastases from breast cancer to an endometrial polyp have been only described in 14 cases; therefore the prognosis and survival are uncertain. We described a case of metastasis from breast carcinoma to an endometrial polyp in a patient who received tamoxifen therapy, with a good outcome and disease-free at 5-years(AU)

Estudio de la erosión de los suelos en áreas protegidas de Cienfuegos, utilizando el cesio 137 como radiotrazador / Soil erosion studies in protected areas of Cienfuegos, using cesium 137 as radiotracer

RESUMEN Las explosiones nucleares de gran potencia a cielo abierto, debido a las pruebas de armas nucleares o como consecuencia de accidentes que han tenido lugar, son las principales causas de que gran número de radionúclidos se haya dispersado en todo el globo terráqueo. Entre estos se encuentra el cesio-137, que al llegar al suelo se adhiere fuertemente a sus partículas más finas. Ello, junto a su período de semidesintegración de 30 años y su fácil detección por gamma espectrometría hacen que se use como radiotrazador de los movimientos del suelo. Esta técnica, ampliamente usada y validada en diferentes entornos en todo el mundo, también fue previamente validada y se demostró su eficacia en la provincia de Cienfuegos. El objetivo de esta investigación fue estudiar mediante el uso del cesio 137, la redistribución del suelo y cuantificar la erosión en áreas protegidas de la provincia, donde las pérdidas de suelo y el arrastre de sedimentos son las principales causas del deterioro de estos ecosistemas con las consiguientes pérdidas económicas y ambientales. Los resultados obtenidos se interpolaron, empleando el método kriging mediante el software gvSIG, obteniendo un mapa de la distribución del suelo en las parcelas estudiadas, y garantizando una mejor visibilidad al respecto. El método se puede aplicar en otros lugares donde sea necesario conocer la magnitud de los problemas de erosión y la redistribución del suelo en el paisaje, lo cual puede ser muy útil para trazar los planes de reordenamiento de los usos del suelo.

ABSTRACT The large-scale nuclear explosions as a result of nuclear weapons tests or nuclear accidents are the main causes of/for the great dispersion of artificial radionuclides all over the world. One of these radionuclides is cesium-137, which is strongly fixed to the fine soils particles. This fact, together with its half-life of 30 years and its easy detection by gamma spectrometry have turned cesium 137, in a good radiotracer of soil movement. This technique has been widely used and validated in different landscapes throughout the world. Its effectiveness was also previously validated and proved in Cienfuegos province as well. This research was aimed at using the cesium-137 technique to study soil redistribution and quantify erosion in the so called Protected Areas in Cienfuegos province, where soil loss and sediment transport are the main causes of deterioration of these ecosystems with the consequent economic and / or environmental losses. The results were represented in a map using the gvSIG software by kriging, thus achieving greater visibility of the soil redistribution in the studied plot. The methodology used in this study could be used in other places wherever the magnitude of erosion problemsas well as knowing the soil redistribution plot pattern in the landscape are necessary and very useful to elaborate plans for rearrangement in land use management.

Presencia de elementos de los cordones sexuales en cistoadenoma seroso de ovario / Ovarian serous cystadenofibroma with sex cord differentiation

Se presenta un caso de cistoadenofibroma seroso ovárico con elementos de los cordones sexuales en una paciente posmenopáusica. A raíz del diagnóstico se realizó una búsqueda bibliográfica, encontrando un único caso previo descrito en la literatura. La presencia de estructuras de los cordones sexuales puede pasar inadvertida en el estudio histopatológico si no se realiza un muestreo exhaustivo y si no se tiene en mente esa posible combinación. Las repercusiones en el pronóstico son inciertas (AU)

A case of ovarian serous cystadenofibroma with sex cord differentiation in a postmenopausal woman is described. The diagnosis prompted a literature search, which revealed only one previous similar case. The presence of sex cord structures can go unnoticed in histopathologic examination if the sampling is not exhaustive or the mixture of both histological types is not considered. The repercussions on prognosis are unknown (AU)

Carcinoma indiferenciado de trompa / Undifferentiated carcinoma of the fallopian tube

La neoplasia primaria de trompa de Falopio es una entidad poco frecuente. El diagnóstico preoperatorio es difícil y en muchas ocasiones es un hallazgo intraoperatorio o un diagnóstico histopatológico. Presentamos un caso de cáncer primario de trompa en una mujer de 61 años con algias pélvicas de un mes de evolución, masa pélvica izquierda dolorosa y Ca 125 elevado. Las pruebas diagnósticas fueron compatibles con patología uterina maligna (sarcoma uterino) o patología neoplásica ovárica izquierda con infiltración uterina como segunda posibilidad. El resultado histológico fue de carcinoma indiferenciado de trompa izquierda que infiltra pared uterina en cuerpo y cérvix. Actualmente, la paciente se encuentra sometida a tratamiento quimioterápico (AU)

Primary carcinoma of the fallopian tube is a rare entity. Preoperative diagnosis is difficult and these tumors are usually detected during surgery or on histopathological examination. We describe the case of a 61-year-old woman with pelvic pain, left adnexal mass and elevated Ca125 levels. Diagnostic tests were compatible with uterine sarcoma or primary left ovarian carcinoma with uterine invasion. Histopathological analysis showed a primary undifferentiated carcinoma of the left fallopian tube involving the uterus and cervix. The patient is currently undergoing chemotherapy (AU)

Hematoma subcapsular hepático en el síndrome de HELLP / Hepatic subcapsular hematoma in HELLP syndrome

Presentamos un caso de rotura hepática espontánea tras la formación de un extenso hematoma subcapsular en una paciente que cursa una gestación normal hasta la aparición del cuadro clínico descrito, no asociado a cuadros hipertensivos severos del embarazo previamente diagnosticados, que se trató de modo conservador mediante empaquetamiento hepático temporal. Posteriormente, la paciente evolucionó de modo satisfactorio, con resultados materno neonatales óptimos (AU)

We present a case of spontaneous hepatic rupture after the formation of a subcapsular hematoma in a patient with a previously normal pregnancy and no previous diagnosis of severe hypertension. The patient was treated conservatively through hepatic packing. Maternal and fetal outcomes were optimal (AU)

Prevalencia del virus de la hepatitis C en las unidades de hemodiálisis de la región occidental cubana / Hepatitis C virus present in hemodialysis units from Cuban western region

La población de hemodiálisis constituye un grupo de alto riesgo en el caso de la infección por el virus de la hepatitis C. Se realizó un análisis multicéntrico de la prevalencia de la infección por el virus de la hepatitis C en las unidades de diálisis de la región occidental aplicando las técnicas serológicas y moleculares, y se observó si existían diferencias significativas en cuanto a la aplicación de ambas técnicas. Se obtuvieron valores elevados de prevalencia de anticuerpos anti-VHC en todas las unidades de diálisis (76 %), así como la calculada aplicando la detección del ARN viral (55 %). No se hallaron diferencias significativas (k) en cuanto a la aplicación de ambas técnicas en la mayoría de las unidades de diálisis analizadas. La elevada prevalencia viral se asocia a la transmisión nosocomial provocada por el incumplimiento de las normas de precaución universal establecidas.

Hemodialysis population is a high risk group related to hepatitis C virus infection. Authors made a multicenter analysis on infection prevalence of hepatitis C virus in dialysis units of western region applying serologic and molecular techniques observing if there significant differences as regards the application of both techniques. We achieved high values of anti-CHV antibody prevalence in all dialysis units (76 %) as well as the estimated prevalence applying viral RNA detection (55 %). There were not significant differences (k) as regards application of both techniques in most of analyzed dialysis units. Viral high prevalence is associated with nosocomial transmission caused by no-fulfillment of established universal precaution standards.

Prevalencia del virus de la hepatitis C en las unidades de hemodiálisis de la región occidental cubana / Hepatitis C virus present in hemodialysis units from Cuban western region

La población de hemodiálisis constituye un grupo de alto riesgo en el caso de la infección por el virus de la hepatitis C. Se realizó un análisis multicéntrico de la prevalencia de la infección por el virus de la hepatitis C en las unidades de diálisis de la región occidental aplicando las técnicas serológicas y moleculares, y se observó si existían diferencias significativas en cuanto a la aplicación de ambas técnicas. Se obtuvieron valores elevados de prevalencia de anticuerpos anti-VHC en todas las unidades de diálisis (76 por ciento), así como la calculada aplicando la detección del ARN viral (55 por ciento). No se hallaron diferencias significativas (k) en cuanto a la aplicación de ambas técnicas en la mayoría de las unidades de diálisis analizadas. La elevada prevalencia viral se asocia a la transmisión nosocomial provocada por el incumplimiento de las normas de precaución universal establecidas(AU)

Hemodialysis population is a high risk group related to hepatitis C virus infection. Authors made a multicenter analysis on infection prevalence of hepatitis C virus in dialysis units of western region applying serologic and molecular techniques observing if there significant differences as regards the application of both techniques. We achieved high values of anti-CHV antibody prevalence in all dialysis units (76 percent) as well as the estimated prevalence applying viral RNA detection (55 percent). There were not significant differences (k) as regards application of both techniques in most of analyzed dialysis units. Viral high prevalence is associated with nosocomial transmission caused by no-fulfillment of established universal precaution standards(AU)

Validación de un método para medir niveles de plutonio en sedimentos marinos en Cuba / Validation of a method to measure plutonium levels in marine sediments in Cuba

RESUMEN El principal objetivo de esta investigación fue desarrollar y validar un método de separación radioquímica del plutonio, factible desde el punto de vista económico y práctico en las condiciones de Cuba que nos permitiera determinar los niveles de plutonio en los sedimentos marinos de la bahía de Cienfuegos. El método de separación radioquímica seleccionado fue el de cromatografía aniónica y la técnica de medición, la espectrometría de masa con cuadrupolo y plasma inducido asociado. El método se aplicó a una muestra de referencia certificada, realizándose seis repeticiones y obteniéndose una buena correspondencia entre el valor medio medido de plutonio y su valor medio certificado. Se comprobó la buena reproducibilidad del método, ya que se obtuvo un coeficiente de variación de 11% para 95% de probabilidad. Los resultados de la aplicación del método validado, revelan que la presencia de plutonio en las muestras analizadas se debe únicamente a las precipitaciones radiactivas globales.

ABSTRACT The main objective of this research was to develop and to validate a method of radiochemical separation of plutonium, suitable from the economic and practical point of view, in Cuba conditions. This method allowed us to determine plutonium activity levels in the marine sediments from Cienfuegos Bay. The selected method of radiochemical separation was that of anionic chromatography and the measure technique was the quadrupole inductively coupled plasma mass spectrometry. The method was applied to a certified reference material, six repetitions were carried out and a good correspondence between the average measured value and the average certified value of plutonium was achieved, so the trueness of the method was demonstrated. It was also proven the precision of the method, since it was obtained a variation coefficient of 11% at 95% confidence level. The obtained results show that the presence of plutonium in the analyzed marine sediment samples is only due to the global radioactive fallout.

Discrimination of Venezuelan spirituous beverages by a trace element-radial basis neural network approach.

Radial basis neural networks (RBNNs) were developed and evaluated for discrimination of specimens of 'aguardiente de Cocuy', a spirituous beverage produced in the northwestern region of Venezuela. The beverage is distilled from the must of Agave cocui Trelease in an artisanship fashion with little quality control. Forty specimens, with known concentrations of copper, iron, and zinc, were used in this study. The specimens were previously collected in various locations around Sucre Municipality (Falcón State) and Urdaneta Municipality (Lara State). The normalized concentrations of these elements served as indirect descriptors of origin (input data). They were presented to the neural networks through 1-3 input nodes in seven different combinations. In addition, two categories (two collection sites) and four categories (two collection sites+two manufacturing conditions) were designated as output data, in order to assess the impact of such selection on the discrimination performance. The overall performance of the four-category RBNNs was as follows (the input data is indicated in parentheses): (Cu-Fe)>(Cu-Zn)>(Cu)>(Zn)>(Fe-Zn)>(Cu-Fe-Zn)>(Fe). In this case, the highest percentage of correct hits was 82.5%. For the two-category RBNNs, the performance decreased as indicated below: (Cu)>(Cu-Fe)>(Cu-Zn)>(Fe-Zn)>(Zn) approximately (Cu-Fe-Zn)>(Fe). The reduction in the number of categories led to an increase in the discrimination performance of all the RBNNs, the best of which was 90.0%. The possibility of discriminating specimens of 'aguardiente de Cocuy' with such an accuracy, based on a single-element determination, is particularly attractive as it would result in a reduction of analysis' costs and laboratory's response time.