Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Más filtros











Base de datos
Intervalo de año de publicación
1.
PLoS One ; 19(5): e0302788, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38722837

RESUMEN

Research has identified Northwest Turkey as a key region for the development of dairying in the seventh millennium BCE, yet little is known about how this practice began or evolved there. This research studies Barcin Höyük, a site located in Bursa's Yenisehir Valley, which ranges chronologically from 6600 BCE, when the first evidence of settled life appears in the Marmara Region, to 6000 BCE, when Neolithic habitation at the site ceases. Using pottery sherds diagnostic by vessel category and type, this paper aims at identifying which ones may have been primarily used to store, process, or consume dairy products. Organic residue analysis of selected samples helped address the process of adoption and intensification of milk processing in this region over time. The lipid residue data discussed in this paper derive from 143 isotopic results subsampled from 173 organic residues obtained from 805 Neolithic potsherds and suggest that bowls and four-lugged pots may have been preferred containers for processing milk. The discovery of abundant milk residues even among the earliest ceramics indicates that the pioneer farmers arrived in the region already with the knowhow of dairying and milk processing. In fact, these skills and the reliance on secondary products may have given them one of the necessary tools to successfully venture into the unfarmed lands of Northwest Anatolia in the first place.


Asunto(s)
Arqueología , Industria Lechera , Turquía , Industria Lechera/historia , Historia Antigua , Humanos , Animales , Leche/química
2.
Rapid Commun Mass Spectrom ; 33(13): 1122-1136, 2019 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-30968483

RESUMEN

RATIONALE: Analytical methods that can identify the source and fate of mercury and organomercury compounds are likely to be useful tools to investigate mercury in the environment. Carbon isotope ratio analysis of methylmercury (MeHg) together with mercury isotope ratios may offer a robust tool to study environmental cycling of organomercury compounds within fish tissues and other matrices. METHODS: MeHg carbon isotope ratios were determined by gas chromatography/combustion-isotope ratio mass spectrometry (GC/C-IRMS) either directly or following derivatization using sodium tetraethylborate. The effects of a normalization protocol and of derivatization on the measurement uncertainty of the methylmercury δ13 CVPDB values were investigated. RESULTS: GC/C-IRMS analysis resulted in a δ13 CVPDB value for an in-house MeHg reference material of δ13 CVPDB = -68.3 ± 7.7‰ (combined standard uncertainty, k = 1). This agreed very well with the value obtained by offline flow-injection analysis/chemical oxidation/isotope ratio mass spectrometry of δ13 CVPDB = -68.85 ± 0.17‰ (combined standard uncertainty, k = 1) although the uncertainty was substantially larger. The minimum amount of MeHg required for analysis was determined to be 20 µg. CONCLUSIONS: While the δ13 CVPDB values of MeHg can be obtained by GC/C-IRMS methods with or without derivatization, the low abundance of MeHg precludes such analyses in fish tissues unless there is substantial MeHg contamination. Environmental samples with sufficient MeHg pollution can be studied using these methods provided that the MeHg can be quantitatively extracted. The more general findings from this study regarding derivatization protocol implementation within an autosampler vial as well as measurement uncertainty associated with derivatization, normalization to reporting scales and integration are applicable to other GC/C-IRMS-based measurements.

3.
Sci Justice ; 59(1): 9-19, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30654973

RESUMEN

Forensic application of carbon isotope ratio measurements of honey and honey protein to investigate the degree of adulteration with high fructose corn syrup or other C4 plant sugars is well established. These measurements must use methods that exhibit suitable performance criteria, particularly with regard to measurement uncertainty and traceability - low levels of adulteration can only be detected by methods that result in suitably small measurement uncertainties such that differences of 1‰ or less can be reliably detected. Inter-laboratory exercises are invaluable to assess the state-of-the art of measurement capabilities of laboratories necessary to achieve such performance criteria. National and designated metrology institutes from a number of countries recently participated in an inter-laboratory assessment (CCQM-K140) of stable carbon isotope ratio determination of bulk honey. The same sample material was distributed to a number of forensic isotope analysis laboratories that could not participate directly in the metrological comparison. The results from these studies have demonstrated that the majority of participants provided isotope delta values with acceptable performance metrics; that all participants ensured traceability of their results; and that where measurement uncertainties were reported; these were fit-for-purpose. A number of the forensic laboratories only reported precision rather than full estimates of measurement uncertainty and this was the major cause of the few instances of questionable performance metrics. Reporting of standard deviations in place of measurement uncertainties is common practice outside metrology institutes and the implications for interpretations of small differences in isotopic compositions are discussed. The results have also highlighted a number of considerations that are useful for organisers of similar inter-laboratory studies in the future.


Asunto(s)
Isótopos de Carbono/análisis , Ciencias Forenses/métodos , Miel/análisis , Laboratorios , Incertidumbre , Internacionalidad , Reproducibilidad de los Resultados
4.
Food Chem ; 175: 273-9, 2015 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-25577080

RESUMEN

High Performance Liquid Chromatography LC-UV and LC-MS/MS methods were developed and validated for quantitative analyses of sodium benzoate and potassium sorbate in foods and beverages. HPLC-UV and LC-MS/MS methods were compared for quantitative analyses of sodium benzoate and potassium sorbate in a representative ketchup sample. Optimisation of the methods enabled the chromatographic separation of the analytes in less than 4 min. A correlation coefficient of 0.999 was achieved over the measured calibration range for both compounds and methods (HPLC and LC-MS/MS). The uncertainty values of sodium benzoate and potassium sorbate were found as 0.199 and 0.150 mg/L by HPLC and 0.072 and 0.044 mg/L by LC-MS/MS, respectively. Proficiency testing performance of Turkish accredited laboratories between the years 2005 and 2013 was evaluated and reported herein. The aim of the proficiency testing scheme was to evaluate the performance of the laboratories, analysing benzoate and sorbate in tomato ketchup.


Asunto(s)
Bebidas/análisis , Cromatografía Líquida de Alta Presión/métodos , Conservantes de Alimentos/química , Benzoato de Sodio/análisis , Ácido Sórbico/análisis , Espectrometría de Masas en Tándem/métodos , Benzoato de Sodio/química , Ácido Sórbico/química , Turquía
5.
Fertil Steril ; 93(5): 1711-4, 2010 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-19909952

RESUMEN

Histomorphologic and morphometric effects of peripubertal superior ovarian nerve (SON) transection were evaluated during adult life in rats. Twenty Sprague-Dawley rats were randomly divided into two groups: the SON-transected (SON-t) group (n = 10) and the sham-operated control group (n = 10). Total follicle development was not influenced; however, follicular maturation was seriously stunted by the procedure, as evidenced by significantly thinner theca interna and follicular wall.


Asunto(s)
Folículo Ovárico/inervación , Ovario/inervación , Desarrollo Sexual , Simpatectomía , Envejecimiento , Animales , Femenino , Modelos Animales , Folículo Ovárico/patología , Ovario/patología , Ratas , Ratas Sprague-Dawley
6.
Arch Gynecol Obstet ; 280(3): 351-5, 2009 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-19130066

RESUMEN

PURPOSE: To update the prevalence and risk factors of intractable postpartum hemorrhage (IPH) and evaluate the effectiveness of surgical treatment modalities. METHODS: Between January 2002 and January 2008, IPH diagnosis was made in 86 cases. They were evaluated retrospectively. RESULTS: Placental implantation abnormalities were the leading cause, responsible for 45.6% of cases. Organ preserving surgery (OPS) methods were utilized in 47 cases, with a success rate of 76.6%. Among these cases, 11 were proceeded to hysterectomy. Hysterectomy was performed in 45 cases as definitive treatment. CONCLUSIONS: Compression sutures were quite effective in controlling hemorrhage due to placenta accreta and previa. For women who are hemodynamically stable and desirous for future fertility, OPS modalities should be applied first. Shorter operating time, hospital stay and less blood transfusion were seen with subtotal type hysterectomy, so in case of nonbleeding lower uterine segment, subtotal type should be performed first.


Asunto(s)
Histerectomía/tendencias , Placenta Accreta/cirugía , Placenta Previa/cirugía , Hemorragia Posparto/cirugía , Técnicas de Sutura/tendencias , Adolescente , Adulto , Femenino , Humanos , Procedimientos Quirúrgicos Obstétricos/tendencias , Hemorragia Posparto/epidemiología , Hemorragia Posparto/etiología , Embarazo , Prevalencia , Estudios Retrospectivos , Factores de Riesgo , Turquía , Adulto Joven
7.
Arch Gynecol Obstet ; 279(2): 239-41, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18506457

RESUMEN

BACKGROUND: Vulvar cancer is a rare gynecological malignancy and its local recurrence is even more uncommon. To date, no cases of recurrent vulvar cancer in split thickness graft area have been reported. We describe the first case of such recurrence. CASE: A 65-year-old G4P3013 presented with vulvar mass and itching. She had a 2 x 2-cm sized mass on clitoris and an ulcerated bulgy mass of 2 x 2.5 cm size was localized on left labia majora, of which a biopsy revealed invasive squamous cell carcinoma. She underwent a radical vulvectomy and bilateral inguinofemoral lymph node dissection via separate incisions. Her postoperative course was complicated by wound separation which was cored with a split thickness skin graft. Patient was advised to integrate her treatment with radiotherapy, but she refused it. Two months later, she consulted for a painful swelling in the operation field. The swelling resembled an abscess formation so it was drained and an outpatient antibiotic treatment was prescribed. At her second visit, it was noted that the above-mentioned lesion was persisting and so fine needle aspiration biopsy (FNAB) was performed and a local recurrence was retrieved beneath the graft failure. Then she underwent a wide local excision and adjuvant radiotherapy was initiated after patient's approval. CONCLUSION: Careful surveillance is warranted as squamous cell carcinoma recurrence can even occur beneath the split thickness skin graft, especially in conjunction with graft failure. And for high risk patients adjuvant radiotherapy is critically important for avoiding recurrences.


Asunto(s)
Absceso , Rechazo de Injerto/diagnóstico , Recurrencia Local de Neoplasia/diagnóstico , Trasplante de Piel , Neoplasias de la Vulva/cirugía , Anciano , Biopsia con Aguja Fina , Carcinoma de Células Escamosas/patología , Carcinoma de Células Escamosas/radioterapia , Carcinoma de Células Escamosas/cirugía , Diagnóstico Diferencial , Femenino , Humanos , Escisión del Ganglio Linfático , Metástasis Linfática/patología , Neoplasias de la Vulva/patología , Neoplasias de la Vulva/radioterapia
8.
Arch Gynecol Obstet ; 278(6): 559-63, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18343934

RESUMEN

OBJECTIVE: We sought to determine whether meconium-stained amniotic fluid is based on chronic hypoxia or not? In case of chronic hypoxia, higher red blood cell (Rbc) count and/or total hemoglobin levels (Hgb) and/or higher fetal hemoglobin (HbF) and/or lower adult hemoglobin (HbA) levels were expected when compared with controls. DESIGN: Case-control study. SETTING: Obstetric unit of a tertiary ministry of health hospital. SAMPLE: Fifty singleton pregnancies with meconium-stained amniotic fluid and 50 singleton pregnancies with clear amniotic fluid at all stages of labor. METHODS: Umbilical cord blood samples were collected for determination of total blood parameters and hemoglobin electrophoresis. MAIN OUTCOME MEASURES: Red blood cell count, total hemoglobin, fetal and adult hemoglobin contents (HbF and HbA). RESULTS: Red blood cell count, total hemoglobin, fetal hemoglobin (HbF) and adult hemoglobin (HbA) contents were not different between meconium stained and clear amniotic fluid groups. CONCLUSION: These results suggest that meconium passage may not be associated with chronic fetal hypoxia as demonstrated by similar red blood cell count, total hemoglobin values and fetal hemoglobin (HbF) and adult hemoglobin (HbA) contents.


Asunto(s)
Líquido Amniótico/química , Sangre Fetal/química , Hemoglobina Fetal/análisis , Hipoxia Fetal/patología , Meconio/química , Adulto , Estudios de Casos y Controles , Recuento de Eritrocitos , Femenino , Hipoxia Fetal/sangre , Humanos , Recién Nacido , Masculino , Embarazo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA