Dynamic Fracture Resistance under Plane Strain Conditions of High-Density Polyethylene Nanoclay Composites.

Polymer nanoclay composites have received significant attention due to their substantially enhanced mechanical, thermal and barrier properties. However, the effect of these nanoclays on the dynamic fracture resistance of a polymer matrix during fast fracture events has not been documented. In this study, the effect of nanoclay addition on the rapid crack propagation (RCP) resistance of high-density polyethylene (HDPE) was investigated through the high-speed double torsion test. Results showed that the addition of 1, 3, and 5% of nanoclays improved the dynamic fracture resistance under the plane strain conditions (Gd1) of HDPE up to 65%. An increase in the storage and loss modulus, and a decrease in crystallinity and melt flow index with nanoclay content was also found. Although the presence of agglomerates can hinder the enhancement of Gd1 as it promotes agglomerate fracture and debonding, the increase in energy consumption through fibrillation and crazing promoted by the nanoclay prevails, suggesting that the nanoclay's toughening effect that has been extensively reported under quasi-static and impact tests, is also present under RCP conditions, and that the HDPE nanocomposites could be used in applications in which RCP must be prevented.

[Lethality by neonatal sepsis, risk factors and microbiological characteristics]. / Letalidad por sepsis neonatal, factores de riesgo y características microbiológicas.

INTRODUCTION: Neonatal sepsis is one of the leading causes of death in this population and is related to gestational and perinatal factors as well as factors inherent in the newborn. OBJECTIVE: To associate perinatal, neonatal, and microbiological factors to sepsis mortality. PATIENTS AND METHOD: Retrospective ca se-control study of hospitalized newborns with confirmed neonatal sepsis through blood cultures, from 2013 to 2019. Cases were defined as those patients with confirmed sepsis that presented a fa tal outcome and controls as those newborns with confirmed sepsis without a fatal outcome. Cases and controls were compared regarding maternal, perinatal, neonatal, and microbiological factors for quantitative variables in order to identify the trend and concentration of the variables studied. RESULTS: Eleven cases were identified and three controls were randomly assigned to each case, stra tified by gestational age groups. The median birth weight and gestational age were 1,004 grams and 28 weeks, respectively. Escherichia coli was identified in 21% of the patients, Candida parapsilosis in 16%, and Staphylococcus aureus in 14%. There was a statistically significant association between sepsis lethality and vaginal delivery (P = 0.023), infection before 7 days of life (P = 0.025), and Can dida parapsilosis infection (P = 0.049). The multivariate analysis determined a statistically significant association between neonatal sepsis lethality and vaginal delivery and microbiological identification of Candida parapsilosis. CONCLUSION: Neonatal sepsis lethality was more frequent in the group of extremely preterm infants, newborns withhistory of vaginal delivery, early microbiological isolation, and t infection with Candida parapsilosis.

Immunization of Bos taurus steers with Babesia bovis recombinant antigens MSA-1, MSA-2c and 12D3.

The purpose of this research was to evaluate the recombinant proteins MSA-1, MSA-2c and 12D3 as a combined immunogen for cattle. Fifteen steers were randomly assigned into three groups of five animals each (I, II and III). On day 0, cattle in group I were injected with 50 microg each of rMSA-1, rMSA-2c and r12D3 with the adjuvant Montanide 75; cattle in Group II received adjuvant-PBS, and Group III were untreated controls. On day 14, cattle in Group I received a second injection of the three recombinant proteins in adjuvant and cattle in Group II again received adjuvant alone. On day 28, all groups of cattle were challenged with a field strain of Babesia bovis. After challenge, the experimental cattle were clinically and serologically monitored. Three of the five steers immunized with the combined recombinant B. bovis proteins seroconverted on day 14 post-immunization (P.I.) and the maximum titre was 1 : 1600. All five immunized steers presented strong seropositivity to B. bovis antigens at day 21 P.I. The prepatent periods of vaccinated cattle were delayed until day 10 post-challenge exposure versus 8 and 7 days in Groups II and III, respectively. Cattle in all groups had fever above 41 degrees C; the reduction in packed cell volume was not significantly different (P > 0.05) in vaccinated group I compared with Groups II and III (29% versus 26% and 31%, respectively). Treatment was required for one steer in the control group. During the period of the study, the weight of cattle in Groups I and II increased an average of 9 and 7 kg, whereas the weight of the control cattle was reduced on average 4 kg. Immunization with rMSA-1-rMSA-2c-r12D3 proteins was not sufficient to prevent clinical symptoms against challenge, but the immunologic response was sufficient to protect steers against a mild virulent strain of B. bovis.

Sedación: analgésia en endoscopía digestiva / Sedation: analgesia in gastrointestinal endoscopy

La sedación es la manipulación del estado cerebral por medios farmacológicos. Su utilización en procedimientos endoscópicos mejora la tolerancia del paciente y facilita la práctica del procedimiento al endoscopista. Todo esto implica que el uso de la sedoanalgesia sea cada vez más habitual durante las exploraciones endoscópicas. Por lo cual médicos encargados de realizar estos procedimientos debemos estar familiarizados con los fármacos utilizados en la sedación, sus antagonistas, las indicaciones y sus compl icaciones.

Utilidad de los predictores clásicos de severidad en pancreatitis aguda / Usefulness of the classic predictors of severity in acute pancreatitis

Objetivo. Evaluar la utilidad de las escalas tradicionales de Ranson, Glasgow, Apache II y Balthazar en la predicción de la severidad de la pancreatitis aguda. Métodos. De forma prospectiva en el servicio de Gastroenterología del HCAM analizamos una serie de casos, entre julio del 2005 y julio del 2006. Se incluyeron 135 de 138 pacientes con pancreatitis aguda, que cumplieron con los criterios de inclusión. Se obtuvo datos clínicos, estudios de laboratorio e imagen para establecer los valores de las escalas de Ranson, Glasgow, Apache 11 y Balthazar. Calculamos sensibilidad, especificidad, valor predictivo positivo (YPP), valor predictivo negativo (VPN) y Likelihood ratio (LR) de cada escala. Resultados. De los 135 pacientes, 101 (74.8%) presentaron PA leve y 34 (25.2%) PA grave. El valor promedio (OS) de las escalas evaluadas en los pacientes con PA leve versus grave fue: Ranson 2,64 (1,41) vs 4,6 (1 ,6); Glasgow 1,81 (1,17) vs 3,32 (1,42); Apache TI 6,84 (3,63) vs 11,82 (5,05); ISTC 1,63 (1,14) vs 7,47 (1,97). La sensibilidad, especificidad, YPP y VPN para cada escala fue: Ranson 76,5%, 72,2%, 48,1%, y 90,1%; Glasgow 70,6%, 72,3%, 46,2% y 87, 9%; Apache 11 82,3%, 57,4%, 39,4% y 90.6%; ISTC 79,4%, 100%, 100% y 93.5% respectivamente, Conclusión. Oe acuerdo a nuestros resultados en esta serie, el ISTC es la mejor escala para predecir la severidad de la PA. Tiene el inconveniente de la temporalidad, ya que se requiere esperar más de 48 horas, para la valoración real.

Comparacion entre la tecnica de capilaridad y la biopsia aspiracion con aguja fina (BACAF) en nodulos de tiroides / Comparison between capillary technique and fine-needle aspiration biopsy (BACAF) in thyroid nodules

La biopsia aspiración con aguja fina de tiroides es el examen de elección en los nódulos tiroideos. Se realizó un estudio en el cual se comparó la técnica de capilaridad con la biopsia por aspiración con aguja fina (BACAF) en lesiones de tiroides.Se efectuaron en total 50 biopsias de tiroides. Sc encontró que los resultados de los extendidos citológicos preparados para cada método fueron comparables en calidad, cantidad y rendimiento diagnóstico. Las dos técnicas tuvieron una adecuada eficacia diagnóstica. Se concluyó que la capilaridad es un excelente método diagnóstico y combinado con el bacaf mejora la sensibilidad diagnóstica.

The thyroid Fine-Needle Aspiration Biopsy is the test of choice for thyroid nodules. We carried out a study to compare the Capillarity technique versus Fine-Needle Aspiration Biopsy (FNAB) in thyroid lesions. We performed 50 thyroid biopsies. We found that the results of the cytology smears prepared for cach technique were comparable in qualit, amount and diagnostic reward. Both techniques had an adequate diagnostic efficacy. We concluded that capillarity, is an excellent diagnostic method and combined with FNAB improves the diagnostic sensitivity.

[Ultrasonography in diagnosis and monitoring the progress of dissection of cervicocerebral arteries]. / La ecografía en el diagnóstico y control evolutivo de las disecciones de arterias cervicocerebrales.

INTRODUCTION: Ultrasonography has become part of the arsenal of diagnostic methods available for examining the dissection of cerebral blood vessels (DCV). AIMS: To analyse the value of ultrasonography in the diagnosis and monitoring of DCV. PATIENTS AND METHODS: We conducted a consecutive study of 67 patients with a history and clinical picture compatible with DCV; all of them had been given confirmation of their diagnosis by another reference method (digital angiography or MR angiography) during the 48 hours prior to or following the ultrasound study. The ultrasonography was carried out on the neck and skull as per the usual system using continuous Doppler, neck duplex and transcranial Doppler ultrasonography. Diagnosis of the dissection was based on direct and indirect signs, in the absence of an atheroma plaque. The following were considered to be direct signs: haematoma in the wall of the vessel, flap, local increase in the flow velocity and echograms with split systole. Indirect signs were: haemodynamic alterations proximal to the dissection, a pattern of slow flow and high resistance. The transcranial Doppler showed the findings lying distal to the dissection to be a lowered mean velocity and pulsatility. RESULTS: The ultrasonography of the series revealed direct signs in 46 patients (69%) and indirect signs in 21 (31%). Ultrasonography was used as the primary diagnostic method in 29 (43%) patients; in the other 38 (57%) it was employed to verify the diagnosis or for the follow up. All the ultrasound diagnoses were confirmed using digital angiography (21 cases) or magnetic resonance angiography (46 cases). CONCLUSIONS: Due to its harmlessness, ultrasonography should be the first examination used to establish a probable diagnosis of DCV.

Manejo anestésico para el trasplante de páncreas: experiencia de cinco casos / Anesthetic management for pancreatic transplantation: the initial experience

El trasplante de páncreas, es la única forma terapéutica que consigue la normalización de la glucos y que libera al enfermo diabético tipo I del tratamiento insulínico. En un periodo de cuatro años se hace una revisión retrospectiva de la expereincia de trasplantes de páncreas en sus diferentes modalidades. En el presente artículo se describen cinco casos y se discuten los aspectos fundamentales del manejo perioperatorio y transanestésico que representa en la actualidad un verdadero desafío para el anestesiólogo

Gammagrafía renal funcional

La medicina nuclear ha desarrollado una variedad de procedimientos dedicados al campo nefro-urológico; algunos de ellos son muy elaborados por lo que hemos seleccionado los mas fáciles y comprensibles para este trabajo. Todas las técnicas se caracterizan por su carácter no invasivo, por ser completamente innocuas, sin efectos secundarios y con baja irradiación al paciente, inferior a las dosis absorbidas en estudios radiográficos. Seleccionando el método adecuado para cada condición patológica podemos evaluar, con elevada eficacia, el flujo y perfusión sanguínea, el estado funcional parequimatoso y la excresión de cada riñon en forma individual que desde hace varios años han sido acogidas con confianza por parte de los mejores hospitales del mundo. Merecen mayor interés, difusión y utilización en nuestro medio.

[Cloning of kDNA minicircles in different species of Leishmania and its use as probes for diagnosis]. / Clonaje de minicírculos de kADN en diferentes especies de Leishmania y su uso como sondas para diagnóstico.

The present study describes the cloning procedure for fragments of kinetoplast DNA minicircles from different Leishmania species and its use for detecting the presence of these parasites. Our methodology was as follow: the DNA of the kinetoplast from Leishmania mexicana amazonensis and Leishmania braziliensis panamensis was extracted, purified and digested with the enzyme Dra I. These fragments were cloned in the site for Hinc II in the plasmid pKS. E. coli was the bacterial strain used for transforming and amplifying the cloned fragments; the selection was carried out in LB medium supplemented with ampicillin. With the clones suspected to be positives we run a Southern blot and total kDNA, from each Leishmania species, was used as hybridization probe. Finally, the cloned purified fragments were tested as diagnostic probes against kDNA from eleven different species of Leishmania and one of Trypanosoma cruzi parasites. After cloning, transforming, amplifying and selecting, we obtained two probes of fragments of kDNA minicircles: one from L. m. amazonensis and the other from L. b. panamensis. Both probes showed high sensitivity for diagnosing cutaneous Leishmania complexes (Mexicana or Braziliensis); however, we observed a low grade crossreaction between some species belonging to the same complex. It is necessary to continue studies in order to obtain subfragments of these probes with a higher grade of specificity at the level of species and subspecies.

[Extracorporeal lithotripsy in children]. / Litotripsia extracorpórea en niños.

14 patients of pediatric age with renal and ureteral calculi were treated with extracorporeal shock wave lithotripsy (Piezolith 2300). Three of the 14 patients had bilateral renal calculi. There were nine male and five female patients with an average age of 9.7 years. Most of the calculi were the renal pelvis. four calculi were smaller than 10 mm, 12 were between 10 and 20 mm and one was a partial staghorn calculi. A double "J" stent way placed in two patients, one with an ureterostomy and another with a partial staghorn calculi. The average number of shock waves received for patient was 4275 with an average voltage of 582 bars. Only 2 patients (16.6%) required sedation, six patients (47%) required more than one session of lithotripsy. The results at 3 months showed that 71.4% of the patients were free of stones. Hematuria was present in all the patients, hyperthermia greater than 38 degrees C and renal colic were present in 21.4% of the cases, two patients with retained ureteral calculi were rendered stone free by endoscopic procedures. In conclusion our results are similar to those reported in the world literature. The use of ultrasound for stone localization prevents unnecessary radiation of the children, and finally with the machine employed most of the treatments can be performed without anesthesia.