EEG-Based Tool for Prediction of University Students' Cognitive Performance in the Classroom.

This study presents a neuroengineering-based machine learning tool developed to predict students' performance under different learning modalities. Neuroengineering tools are used to predict the learning performance obtained through two different modalities: text and video. Electroencephalographic signals were recorded in the two groups during learning tasks, and performance was evaluated with tests. The results show the video group obtained a better performance than the text group. A correlation analysis was implemented to find the most relevant features to predict students' performance, and to design the machine learning tool. This analysis showed a negative correlation between students' performance and the (theta/alpha) ratio, and delta power, which are indicative of mental fatigue and drowsiness, respectively. These results indicate that users in a non-fatigued and well-rested state performed better during learning tasks. The designed tool obtained 85% precision at predicting learning performance, as well as correctly identifying the video group as the most efficient modality.

Chemical characterization (LC-MS-ESI), cytotoxic activity and intracellular localization of PAMAM G4 in leukemia cells.

Generation 4 of polyamidoamine dendrimer (G4-PAMAM) has several biological effects due to its tridimensional globular structure, repetitive branched amides, tertiary amines, and amino-terminal subunit groups liked to a common core. G4-PAMAM is cytotoxic due to its positive charges. However, its cytotoxicity could increase in cancer cells due to the excessive intracellular negative charges in these cells. Furthermore, this work reports G4-PAMAM chemical structural characterization using UHPLC-QTOF-MS/MS (LC-MS) by electrospray ionization to measure its population according to its positive charges. Additionally, the antiproliferative effects and intracellular localization were explored in the HMC-1 and K-562 cell lines by confocal microscopy. The LC-MS results show that G4-PAMAM generated multivalent mass spectrum values, and its protonated terminal amino groups produced numerous positive charges, which allowed us to determine its exact mass despite having a high molecular weight. Additionally, G4-PAMAM showed antiproliferative activity in the HMC-1 tumor cell line after 24 h (IC50 = 16.97 µM), 48 h (IC50 = 7.02 µM) and 72 h (IC50 = 5.98 µM) and in the K-562 cell line after 24 h (IC50 = 15.14 µM), 48 h (IC50 = 14.18 µM) and 72 h (IC50 = 9.91 µM). Finally, our results showed that the G4-PAMAM dendrimers were located in the cytoplasm and nucleus in both tumor cell lines studied.

Andean drought and glacial retreat tied to Greenland warming during the last glacial period.

Abrupt warming events recorded in Greenland ice cores known as Dansgaard-Oeschger (DO) interstadials are linked to changes in tropical circulation during the last glacial cycle. Corresponding variations in South American summer monsoon (SASM) strength are documented, most commonly, in isotopic records from speleothems, but less is known about how these changes affected precipitation and Andean glacier mass balance. Here we present a sediment record spanning the last ~50 ka from Lake Junín (Peru) in the tropical Andes that has sufficient chronologic precision to document abrupt climatic events on a centennial-millennial time scale. DO events involved the near-complete disappearance of glaciers below 4700 masl in the eastern Andean cordillera and major reductions in the level of Peru's second largest lake. Our results reveal the magnitude of the hydroclimatic disruptions in the highest reaches of the Amazon Basin that were caused by a weakening of the SASM during abrupt arctic warming. Accentuated warming in the Arctic could lead to significant reductions in the precipitation-evaporation balance of the southern tropical Andes with deleterious effects on this densely populated region of South America.

New technique for nephron-sparing surgery in polar tumours. A modification of the Kim technique. / Nueva técnica para cirugía conservadora de nefronas en tumores polares. Una modificación de la técnica de Kim.

INTRODUCTION AND OBJECTIVES: Nephron-sparing surgery (NSS) is the indication, provided it is feasible and meets the international treatment guidelines. One of the objectives of performing NSS is to reduce the ischemia time as much as possible. We propose a surgical technique for treating polar renal tumours and those larger than 4cm based on the principle of the technique described by Kim in 1964. METHOD: The technique performs a continuous circular suture on the base of the tumour, achieving compression of the renal pole without vascular clamping, facilitating haemostasis and avoiding the blind transfixion performed in Kim's original technique. We selected 28 patients for the implementation of the technique. RESULTS: The patients' mean age was 56 years (30-69). The R.E.N.A.L. scores were as follows: 12 of low complexity, 12 of moderate complexity and 4 of high complexity. The mean surgical time was 109minutes (75-140), and the mean estimated blood loss was 120mL (50-300mL). No positive margins were identified, and no patients required blood transfusions. The mean stay was 3.7 days (2-6). There were no Clavien grade 2 or higher complications. There were 3 Clavien 1 complications (fever). The difference in glomerular filtration rate was -0.71mL/min/m2. The pathology was malignant in 26 cases, 19 of them clear-cell carcinomas. Two cases were reported as oncocytomas. CONCLUSION: The proposed technique showed acceptable results, with a low rate of complications in the patient group.

[Appropriateness of emergency hospital admissions]. / Adecuación de los ingresos hospitalarios urgentes.

INTRODUCTION: The aim of this work is to know the proportion of inadequate urgent admissions in a general hospital. MATERIAL AND METHODS: A retrospective and descriptive study of patients admitted during 1,999 was performed. The Appropriatness Evaluation Protocol (AEP) was used in order to evaluate the appropriatness of the admissions. RESULTS: Eighteen admissions (4.5%) were inadecuated. There was a higher proportion of inappropriate admission (IA) when the physician responsible of the admission was a medical specialist (internal medicine, hematology or nephrology): odds ratio 5.3 in opposite to emergency physicians (p < 0.03). CONCLUSIONS: There was a low proportion of inadequate admissions (4.5%) and the risk of inappropriatness of the admission was major when it was ordered by a medical specialist.

[Inappropiate visits to emergency department of a general hospital].

The proportion of inadequate attendances at emergency department (ED) is 20-80%. The suitability of attendances at ED was evaluated using an Hospital Emergency Suitability Protocol, which was validated. 37.9% of attendances were inappropriate and they are more frequent in children. Patients who were referred by a doctor, with trauma or surgical consulted more adequately. The suitability of attendances at ED are related with illness.

Attendance of patients with minor head injury in an emergency department observation ward.

A retrospective study was undertaken to compare the management of head injured patients in a short stay ward (SSW) with their management in other departments in the same hospital, where there is no neurosurgery department. Head injured patients were admitted to the general surgery department until November 1998, when the SSW was inaugurated. The following data were collected for all head injured patients admitted between 1997 and 1999: age, gender, diagnosis, outcome categories and length of stay. A total of 225, 238 and 340 head injured patients were admitted in 1997, 1998 and 1999 respectively. Patients in the neurology department were older (60 +/- 23 years) than in the SSW (41 +/- 23 years) and general surgery department (42 +/- 20 years). Patient diagnosis was similar in the SSW, paediatrics and general surgery departments but patients admitted to the neurology department had more skull fractures and intracranial injuries. The length of stay was longer in general surgery (3.5 +/- 3.9 days) and neurology departments (9.6 +/- 19.1 days) than in the SSW (1.4 +/- 0.8 days) and paediatrics department (1.5 +/- 1.5 days). Thirteen patients in the SSW required admission to another department in the hospital and only one was transferred to the neurosurgery department in another hospital. The results support the view that SSWs are suitable in the management of head injured patients.