Evaluation of the Joining Response of Biodegradable Polylactic Acid (PLA) from Fused Deposition Modeling by Infrared Laser Irradiation.

The development of high-complexity geometry parts is one of the main goals of additive manufacturing technology. However, the failure of printed structures and the joining of different parts to create complex assemblies represents a real challenge in the research of efficient and sustainability techniques for the permanent assembly of polymers. Laser welding processes have been used as a single-step method to join metals for years. Nowadays, the growing trend in the use of thermoplastics for additive manufacturing has led to the need to adapt this technique to materials with a very specific nature and which are more sensitive to thermal effects. In addition, the possibility of transmitting the laser beam through transparent polymer layers allows to us focus the energy supply on internal sections of the assembled components. In this research, an infrared laser marking system was used to join two different samples of polylactic acid manufactured by fused deposited modeling technology. In order to increase the effectiveness of the bonding process, a transparent and a dark sample have been used as assembly material, focusing the laser beam on the interface area of the two parts. By means of tensile tests, dimensional measurement and the use of optical microscopy techniques, a basis was established that links the supplied energy by laser to the joining performance.

Short report - Usefulness of point-of-care ultrasound in pediatric SARS-CoV-2 infection.

SARS-CoV-2 infection in children is uncommon compared to adult population. However, some children required hospital and/or PICU admission. The aim of this short communication is to share our experience with Point-of-Care Ultrasound (POCUS) when managing these patients. Remarkably, all cases presented pleural and pericardial effusions, detected by POCUS, despite showing an adequate urinary output and prior to receiving any kind of fluid resuscitation. Effusions have been described as rare among SARS-CoV-2 infection in adult population. By performing portable chest X-Ray they would have gone unnoticed in our patients. Other POCUS findings consisted of all types of consolidations and coalescent B-line patterns. POCUS was also performed in order to optimize PEEP, checking adequate endotracheal intubation positioning (avoiding the risk of contagiousness related to auscultation in this framework), and to assess volemia status, cardiac performance, and brain neuro-monitoring. There was not cross-infection. In pediatric SARS-CoV-19 effusions are frequent but easily unnoticed unless lung and echo POCUS are performed.

Novel consortium of Klebsiella variicola and Lactobacillus species enhances the functional potential of fermented dairy products by increasing the availability of branched-chain amino acids and the amount of distinctive volatiles.

AIMS: Identify novel bacterial taxa that could increase the availability of branched-chain amino acids and the amount of distinctive volatiles during skim milk fermentation. METHODS AND RESULTS: We recovered 344 bacterial isolates from stool samples of healthy and breastfed infants. Five were selected based on their ability to produce branched-chain amino acids. Three strains were identified as Escherichia coli, one as Klebsiella pneumoniae and other as Klebsiella variicola by molecular and biochemical methods. HPLC and solid-phase microextraction with GC-MS were used for the determination of free amino acids and volatile compounds respectively. The consortium formed by K. variicola and four Lactobacillus species showed the highest production of Leu and Ile in skim milk fermentation. In addition, the production of volatile compounds, such as acetoin, ethanol, 2-nonanone, and acetic, hexanoic and octanoic acids, increased in comparison to commercial yogurt, Emmental and Gouda cheese. Also, distinctive volatiles, such as 2,3-butanediol, 4-methyl-2- hexanone and octanol, were identified. CONCLUSION: The use of K. variicola in combination with probiotic Lactobacillus species enhances the availability of Leu and Ile and the amount of distinctive volatiles during skim milk fermentation. SIGNIFICANCE AND IMPACT OF THE STUDY: The identified consortium increases the functional potential of fermented dairy products.

Assessment of engineered surfaces roughness by high-resolution 3D SEM photogrammetry.

We describe a methodology to obtain three-dimensional models of engineered surfaces using scanning electron microscopy and multi-view photogrammetry (3DSEM). For the reconstruction of the 3D models of the surfaces we used freeware available in the cloud. The method was applied to study the surface roughness of metallic samples patterned with parallel grooves by means of laser. The results are compared with measurements obtained using stylus profilometry (PR) and SEM stereo-photogrammetry (SP). The application of 3DSEM is more time demanding than PR or SP, but it provides a more accurate representation of the surfaces. The results obtained with the three techniques are compared by investigating the influence of sampling step on roughness parameters.

[Antibiotic prophylaxis for surgical wound infection in cardiac surgery: results of a Spanish survey]. / Encuesta nacional sobre profilaxis antibiótica de infección de herida quirúrgica en cirugía cardíaca.

INTRODUCTION: No Spanish guidelines for the prevention of surgical wound infection in paediatric cardiac surgery are currently available. The aim of this study was to analyse the nationwide variability in antibiotic prophylaxis use. MATERIAL AND METHODS: An online questionnaire was distributed to all members of the Cardiology Group of the Spanish Society of Paediatric Intensive Care. Fifteen centres participated in the study. RESULTS: In heart surgery with no delayed sternal closure, all 15 centres used a 1st or 2nd generation cephalosporin in paediatric patients, while 3 hospitals used a broader-spectrum antibiotic therapy in neonates. Prophylaxis was maintained for 12-72h in 11 centres and until drainage removal in four. Thirteen centres used delayed sternal closure, eight of which followed the same protocol for these patients as for standard procedures. Prophylaxis was maintained for 12-72h in 6 centres, and until sternal closure at the rest. Five out of 10 centres performing extracorporeal membrane oxygenation (ECMO) maintained the same antibiotic protocol as in standard surgery. CONCLUSIONS: A wide variability was observed in antibiotic prophylaxis use in high-risk patients. Thus, national protocols need to be standardised.

[Care of the critically ill child with heart disease in Spain]. / La asistencia al niño crítico con cardiopatía en España.

INTRODUCTION: The objective of the present study is to present the organization of the resources of paediatric cardiac critical care in Spain. PATIENTS AND METHODS: Data were collected through questionnaires sent by e-mail to Spanish PICUs. RESULTS: 22 PICUs were enrolled. The median number of beds were 9.5 (4-18 beds). Total cardiac admissions represented a 20 % of total PICUs admissions per year, firstly for congenital heart defects, and secondly for respiratory problems. Cardiac surgical activities were carried out in 16 centres, centralized in PICU in 10 cases. Mechanical support of the myocardium was performed in 7 PICUs. A total of 10 participating PICUs considered echocardiograph training necessary and also an increase in the amount of activity for better results. CONCLUSIONS: Paediatric cardiac critical care involves a significant use of resources, including PICUs with no surgical activity. This study is useful for detecting common problems and for improving clinical care.

[Early postoperative complications of thoracoscopy versus thoracotomy in pediatric idiopathic scoliosis]. / Estudio comparativo de las complicaciones postoperatorias inmediatas de la toracoscopia frente a la toracotomía en la escoliosis idiopática infantil.

INTRODUCTION: Thoracoscopic surgery has been used for anterior release, discectomy, and fusion in severe scoliosis or kyphosis. The indications of thoracoscopy for the treatment of pediatric spinal deformity are similar to those of thoracotomy-based spinal surgery. OBJECTIVE: We designed a comparative study to observe the immediate complications in the postoperative period after thoracoscopy or thoracotomy for scoliosis in the pediatric population. MATERIAL AND METHODS: The postsurgical complications of 63 interventions for idiopathic scoliosis over a 10-year period were analyzed. Conventional thoracotomy was used in 37 interventions (59 %) and thoracoscopy was used in 26 (41 %). RESULTS: In patients treated with the thoracolumbar endoscopic procedure, oral nutrition was resumed earlier, the mean length of hospital stay was lower, and debit drainage or requirement of surgical drainage were lower. CONCLUSIONS: Fewer immediate postsurgical complications were observed in scoliosis surgery when thoracoscopy was used.

[Early postoperative complications after scoliosis surgery]. / Complicaciones médicas precoces en el postoperatorio de cirugía de escoliosis.

Several medical complications can occur after scoliosis surgery in children and adolescents. New surgical techniques have allowed greater degrees of scoliosis correction but have also increased the possibility of postsurgical deficit due to their greater aggressivity. We analyzed the early postsurgical complications of scoliosis surgery in a pediatric intensive care unit over a 10-year period. Seventy-six surgical procedures were performed. Of these, no complications occurred in 55 (73%). Chest X-ray revealed pulmonary atelectasia in 8 patients (10%) and pleural effusion in 7 patients (9%). Symptoms and signs of infection related to surgery were observed in only 6 children (8%). The absence of severe medical complications may be related to new surgical techniques and an experienced team.

[Ventilation in special situations. Mechanical ventilation in congenital cardiopathies and pulmonary hypertension]. / Ventilación en situaciones especiales. Ventilación mecánica en cardiopatías congénitas e hipertensión pulmonar.

The cardiovascular and respiratory systems act as a functional unit. Mechanical ventilation modifies pulmonary volumes, which generates changes in autonomic nervous system reactivity and provokes tachy- or brady-cardia (depending on the tidal volume used). Mechanical ventilation also decreases cardiac filling volumes (pre-load) and alters pulmonary vascular resistances. In addition, intrathoracic pressures are enlarged, which usually produces a decrease in right atrium filling and an increase in right ventricle afterload. If coronary flow is impaired, myocardial contractility is reduced. However, if cardiac failure is present, mechanical ventilation is especially beneficial because it corrects hypoxia and respiratory acidosis, decreases the work of breathing, and improves stroke volume. Mechanical ventilation in congenital heart diseases is indicated either as lifesaving support or as physiopathological treatment to modify the ratio between pulmonary and systemic flow. As a general rule, if excessive pulmonary blood flow is present, the aim of respiratory support is to increase pulmonary vascular resistance by using high levels of airway pressure and even by delivering FiO2<21%. When there is low pulmonary flow, the lowest possible intrathoracic pressures should be used, especially in cases of pulmonary hypertension, which will also require high FiO2. However, mechanical ventilation has adverse effects and consequently it must be stopped as early as possible, once the child is stable and requires minimal cardiopulmonary support. Weaning can even be performed in the operating room, when the surgical procedure is finished. When this is not possible, weaning should be performed in the pediatric intensive care unit. Because there are no criteria for successful withdrawal of mechanical support in congenital heart disease, general pediatric criteria should be used.

[Techniques and complementary techniques. Complementary treatments: nitric oxide, prone positioning and surfactant]. / Técnicas y tratamientos complementarios. Tratamientos complementarios: óxido nítrico, posición en prono y surfactante.

The management of hypoxic respiratory failure is based on oxygen delivery and ventilatory support with lung-protective ventilation strategies. Better understanding of acute lung injury have led to new therapeutic approaches that can modify the outcome of these patients. These adjunctive oxygenation strategies include inhaled nitric oxide and surfactant delivery, and the use of prone positioning. Nitric oxide is a selective pulmonary vasodilator that when inhaled, improves oxygenation in clinical situations such as persistent pulmonary hypertension of the newborn, pulmonary hypertension associated with congenital heart disease, and acute respiratory distress syndrome (ARDS). When applied early in ARDS, prone positioning improves distribution of ventilation and reduces the intrapulmonary shunt. The surfactant has dramatically decreased mortality caused by hyaline membrane disease in premature newborns, although the results have been less successful in ARDS. Greater experience is required to determine whether the combination of these treatments will improve the prognosis of these patients.

[Double total anomalous pulmonary venous connection]. / Conexión venosa pulmonar anómala total doble.

We present a newborn infant with right atrial isomerism, complex congenital heart malformation and anomalous pulmonary venous connection, reliably diagnosed by 2-D Doppler color echocardiography. The infant had no significant obstetric antecedents. The neonatal clinical picture included cyanosis, heart murmur and respiratory distress. The infant was treated with prostaglandin from the age of 24 hours until his death after surgery. The 2-D echo Doppler color flow mapping showed findings that suggested right atrial isomerism, severe left ventricular hypoplasia, pulmonary atresia and ductus arteriosus. The pulmonary veins flowed together to a posterior cardiac chamber from which an emissary vertical venous vessel connected with a left superior aneurysmal sack. Two venous channels emerged from this sack: one connecting to the innominate vein and the other to the atrium. The malformations were confirmed by cardiac catheterization. On the sixth day of life, the patient underwent anastomosis between the posterior venous chamber with the atrium, a modified Blalock-Taussig shunt implant, and ductus closure but died during surgery. The association between complex cardiac anomalies and uncommon obstructive total anomalous pulmonary venous connection in the context of right atrial isomerism is lethal and few neonates survive surgical repair. Two-dimensional echo color flow Doppler is a reliable diagnostic technique and an indispensable guide in angiography.

[Efficacy of various therapeutic measures in metabolic hyperammonemia]. / Eficacia de las diversas medidas terapéuticas en la hiperamoniemia de origen metabólico.

OBJECTIVE: The aims of this work were to describe the therapeutic options available for severe hyperammonemia in children when ammonium levels are so high that the child's neurologic future or even their life is compromised. In addition, a comparison of the relative efficacy of each therapeutic method is made. PATIENTS AND METHODS: We present six cases, five of which suffered from inborn errors of metabolism and a six which presented with Reye's syndrome, all of whom presented or developed hyperammonemic coma. Their initial ammonium levels fluctuated between 300 and more than 2000 micrograms per deciliter. The treatment was made with exchange transfusion (ET), ET and peritoneal dialysis (DP) together or hemodialysis (HD). RESULTS: Peritoneal dialysis was the method that obtained the greatest reduction in plasma ammonium levels. However, the quickest reduction was observed with ET and HD. There were no significant complications with any of the methods except for hemodynamic deterioration in one patient during HD. CONCLUSIONS: We believe that HD is the treatment of choice for these patients because it is able to obtain a quick and lasting clearance of plasma ammonium. However, this method is not always available and has not been used very often in small babies. In these cases, the combined use of ET and DP can be very useful.

[Risk factors for ischemic heart disease in Mexico: a case control study]. / Factores de riesgo para cardiopatía isquémica en México: un estudio de casos clínicos y testigos.

A case control study was developed in order to assess the strength of the association of modifiable risk factors and the occurrence of coronary heart disease in Mexicans. A total of 284 incident cases of acute myocardial infarction and 284 age and sex matched hospitalized controls were included in the study. Information was obtained in all subjects regarding socio-demographic variables, history of diabetes, hypertension, smoking, obesity and serum cholesterol. A conditional logistic regression model, showed that diabetes mellitus, hypertension, smoking, hypercholesterolemia and obesity, explained the occurrence of coronary heart disease in the studied population. The risk of an acute myocardial infarction heavily increases in the extreme levels of exposure; and this risk is six fold higher in those who daily smoke more than 20 cigarettes, and it is eight fold higher in those subjects with a serum cholesterol greater than 240 mg/dl. Due to the increase in the occurrence of coronary heart disease in Mexico, and the strength of the association observed with these modifiable risk factors, a public health program to decrease its prevalence, is justified.

[The need, supply and demand for epidemiological research personnel in the Instituto Mexicano del Seguro Social]. / Necesidades, oferta y demanda de personal en investigación epidemiológica en el Instituto Mexicano del Seguro Social.

In 1991 the Directorate of Public Health was created at the Mexican Institute for Social Security, with its epidemiologic activities oriented towards surveillance and research. This new vision, as well as the epidemiologic transition in Mexico, have raised the need for researchers training. In 1988 the Specialization Course in Public Health was developed as a response to the detected needs. This course was reformed three years later in duration, depth and name (Epidemiology instead of Public Health). The requirement of a thesis has led to the development of epidemiologic and health services research. Two diplomates in epidemiology and immunology and microbiology were also developed as a response to the need of actualization due to the advances in epidemiologic methodology in the past decades. A demand for actualization and continuous education has been expressed by the epidemiologists through a survey. The Directorate has also proposed priority themes for research in order to guide the requirements of research raised by the epidemiologist already trained at the Institute.

[Effect of a combination of gestoden-ethylene estradiol on the endometrium]. / Efectos de la combinación gestodeno etinilestradiol sobre el endometrio.

It has been long established that contraceptive steroid mixtures are highly effective due to the fact that they act simultaneously upon different levels of the pituitary-ovarian-genital tract axis. We hypothesized that the mixture of 30 mcg of ethynylestradiol plus 75 mcg of gestodene might be effective partly through the changes it induces in the histology and histochemistry of the endometrium. To test this hypothesis, 32 healthy patients willing to participate, aged 23 to 34 years, were treated with the above mentioned combination of steroids from day 1 through day 21 of the cycle for six consecutive cycles. They were previously proven to be fertile and ovulatory. In ten of them, selected at random, an endometrial biopsy was taken on the cycle previous to therapy and upon completion of the steroid treatment, for comparison. Tissues were processed for histologic evaluation with hematoxylin-eosin and with acridine orange for the histochemical demonstration of glycogen and ribonucleic acid under fluorescence microscopy. All pre-treatment endometria showed normal findings for ovulatory cycles, while the post-treatment tissues were typical of the steroid-treated endometria, i.e., they had a disrupted balance between glandular and stromal maturation, plus a diminished and abnormally distributed glycogen and ribonucleic acid. We conclude that the established working hypothesis was confirmed.

[Epidemiology of cervical cancer at the Mexican Institute of Social Security]. / Epidemiología del cáncer cervicouterino en el Instituto Mexicano del Seguro Social.

In order to study the secular trend and age and geographic distribution of cervical cancer at the Mexican Institute for Social Security, an ecologic study was carried on. During the last 10 years cervical cancer has been the second most common neoplasia, being the leading one in women. For those between 30 and 44 years old it is the third cause of death, and one of the first ten in all age groups until 64. Mortality has shown a stable trend for the last 15 years, in a range from 3.3 to 4.5 deaths per 100,000 inhabitants. Mortality rates increase with age. There is a fine-fold increase in the risk of death for women 40 to 49 years old (CI 95% 4.2-6.4%) and a tenfold increase for those over 80, (CI 95% 7.3-12.6) when taking those under 40 years old as a reference group. In 1989, the cervical cancer incidence was 9.7 cases for each 100,000 person-years. Morbidity and mortality are unequally distributed along the country. There is a need for the development of research in order to know better the occurrence of this disease as well as how known risk factors affect it.

[Treatment of the hyperprolactinemic states with lisuride in a simple open study]. / Tratamiento de los estados hiperprolactinémicos con lisurida en un estudio simple abierto.

A simple open study was undertaken in order to assess the value of the dopamine-agonist lisuride in the treatment of patients with two types of hyperprolactinemia: Six patients with pituitary adenoma and two with "idiopathic hyperprolactinemia". All patients were started on a dose of 0.2 mg per os per day until values of serum prolactin became normal (two to eleven months in the first group), except for two that required increment to 0.4 mg/day after the first four months without effect; both responded satisfactorily to the increased dose. Side effects were mild nausea end occasional vomiting, except in one case of the first group, which abandoned the treatment due to intense vomiting. One of the patients of "idiopathic hyperprolactinemia" required the dose to be increased to 0.4 mg/day after the first four months and finally responded after two more months with the higher dose. The second patient of this group did not respond even to a dose of 1 mg/day, which was otherwise well tolerated.