10 research outputs found

    Palaeoenvironmental and chronological context of hominin occupations of the Armenian Highlands during MIS 3:Evidence from Ararat-1 cave

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    Archaeological and palaeoenvironmental evidence from the Armenian Highlands and wider southern Caucasus region emphasises the significance of Marine Oxygen Isotope Stage 3 (c. 57–29 ka) as a crucial period for understanding hominin behaviours amidst environmental fluctuations. Ararat-1 cave, situated in the Ararat Depression, Republic of Armenia, presents potential for resolving emerging key debates regarding hominin land use adaptations during this interval, due to its well-preserved lithic artefacts and faunal assemblages. We present the first results of combined sedimentological, geochronological (luminescence and radiocarbon), archaeological and palaeoecological (macrofauna, microfauna and microcharcoal) study of the Ararat-1 sequence. We demonstrate sediment accumulation occurred between 52 and 35 ka and was caused by a combination of aeolian activity, cave rockfall and water action. Whilst the upper strata of the Ararat-1 sequence experienced postdepositional disturbance due to faunal and anthropogenic processes, the lower strata remain relatively undisturbed. We suggest that during a stable period within MIS 3, Ararat-1 was inhabited by Middle Palaeolithic hominins amidst a mosaic of semi-arid shrub, grassland, and temperate woodland ecosystems. These hominins utilised local and distant toolstone raw materials, indicating their ability to adapt to diverse ecological and elevation gradients. Through comparison of Ararat-1 with other sequences in the region, we highlight the spatia

    Interstitial Li + Controls the UV Transmission and the Radiation Hardness in YAG

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    International audienceOptical absorption spectra measured in as‐grown and gamma‐ray irradiated un‐doped YAG, Li‐doped YAG, and Ca‐doped YAG single crystals are compared for characterization of effects introduced by impurities. The studies are conducted on single crystals grown by the vertical Bridgman method. Basing on the Li+ incorporation mechanism, clarification is done regarding the optimal amounts of Li+ for preparation of YAG:Li crystals with low concentration of anion vacancies and related defects giving rise to absorption in the UV range. Differences in behavior are recorded in variously doped crystals subjected to gamma‐ray irradiation; in comparison to un‐doped YAG, the induced absorption coefficient in Li‐doped YAG of optimal composition is lower more than six times. High transmission in the UV and high radiation tolerance are important for most applications of YAG, especially when operated in high radiation fields

    Gastrectomy for metastatic gastric cancer: a 15-year experience from a developing country

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    The role of surgery in the management of metastatic gastric cancer (MGC) remains unclear. The aim of this study was to investigate the surgical and oncologic outcomes of gastrectomy in patients with MGC. The study included prospectively collected data of patients with MGC operated at four medical centers in Yerevan, Armenia, between 2000 and 2014. Armenian National Center of Oncology Registry and hospital records were used to obtain survival data. Factors associated with performing gastrectomy in patients with MGC were analyzed by using the logistic regression model. The Kaplan-Meier method was applied for survival analysis, and the Cox regression model with backward selection was used for multivariate analysis. A total number of 733 patients were operated for gastric cancer including 112 (15.3%) with MGC. Of those, 70 underwent gastrectomy, while 42 had exploratory laparotomy or bypass. Morbidity and mortality were similar after gastrectomy and exploratory laparotomy/bypass (18.6 vs 21.4%, p = 0.71 and 2.9 vs 7.1% p = 0.36, respectively). Female gender, involvement of N1 and/or N2 lymph node stations, and differentiated adenocarcinoma were associated with opting for gastrectomy. Gastrectomy with synchronous resection of distant metastases resulted in postoperative outcomes similar to those following gastrectomy without synchronous organ resection. Median follow-up was 6 months. Eighteen (16.1%) patients received chemotherapy. Median survival following gastrectomy and exploratory laparotomy/bypass were 7 and 4 months (p = 0.015), respectively. The use of chemotherapy following gastrectomy significantly improved survival compared with gastrectomy only (14 vs 6 months, p = 0.01). In the multivariable analysis, chemotherapy and nodal stage correlated with survival after gastrectomy. Gastrectomy for MGC is associated with satisfactory surgical outcomes and can be combined with synchronous resection of distant metastases in selected patients. Gastrectomy results in longer survival compared with exploratory laparotomy/bypass, especially when followed by chemotherap

    Billroth-I anastomosis in distal subtotal gastrectomy for non-early gastric adenocarcinoma

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    Billroth-I (B-I) anastomosis is known as a simple and physiological reconstruction method after distal subtotal gastrectomy for early gastric cancer. Yet its role and oncological validity in non-early gastric adenocarcinoma (NEGA) remain unclear

    Prognostic Factors of Children Admitted to a Pediatric Intensive Care Unit After an Episode of Drowning

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    [eng] Objective The aim of this study was to evaluate the prognostic factors of patients admitted to a pediatric intensive care unit (PICU) after drowning. Methods Retrospective observational study from January 1992 to December 2004 and prospective study from January 2005 to December 2015 were conducted in a tertiary children's hospital PICU. The data analyzed refer to the patient, event, type of resuscitation performed, and clinical situation after resuscitation and at arrival to the PICU; results of additional tests; and clinical evolution and neurological status at discharge from the PICU (categorized as death, severe encephalopathy, or normal). The considered potential prognostic factors were whether drowning was witnessed, the type of initial resuscitation, Glasgow Coma Scale score at admission, pupil status and reactivity, and pH. Results One hundred thirty-one patients were registered. Mortality was 16.7%, and 8.3% had significant neurological sequelae. The clearest factor associated with poor outcome was the type of initial resuscitation performed. All patients who did not require cardiopulmonary resuscitation (CPR), or only basic CPR, had good outcomes; 96.3% of those who required advanced CPR with epinephrine administration had poor outcomes. Patients who needed advanced resuscitation with administration of epinephrine had lower temperature, Glasgow Coma Scale score, pH, and bicarbonate at admission and higher level of glucose. In this group, there was also a higher incidence of seizures, acute respiratory distress syndrome, hemodynamic compromise, and acute renal failure. Conclusions The need for advanced CPR with epinephrine administration on the scene predicts poor neurological outcome (severe encephalopathy or death) in drowned children
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