Determination of ultra-low concentrations of gaseous 14C-bearing hydrocarbons produced during corrosion of irradiated steel using accelerator mass spectrometry.

Compound-specific radiocarbon analysis (CSRA) was developed to identify and quantify gaseous 14C-bearing carbon compounds at the pico- to femtomolar concentration range and employed in a corrosion experiment with small specimens of irradiated steel. The approach is based on gas chromatographic separation of single 14C-bearing carbon compounds, their oxidation to 14CO2, sampling with a custom-made fraction collector and quantification by accelerator mass spectrometry (AMS). In addition to CSRA, a method allowing the quantification of the total 14C content of the gas phase was developed and tested. After validation of the two set-ups with standards, the gaseous 14C-bearing carbon compounds produced during alkaline anoxic corrosion of irradiated steel were quantified. Small hydrocarbons (HCs) like methane (14CH4) and ethane (14C2H6) were the only 14C-bearing compounds identified in the gas phase above the detection limit. 14CH4 was the main species (on average 5.4 × 10-14 mol L-1 gas) and contributed >90% to the total 14C content, whereas the concentration of 14C2H6 was much lower (7.9 × 10-16 mol L-1 gas). To our knowledge, this is the first study reporting CSRA of gaseous 14C-bearing HCs produced during anoxic corrosion of irradiated metallic radioactive waste at ultra-low concentrations.

Crescendo, diminuendo and subito of the trumpets: winds of change in the concerted evolution between flowers and pollinators in Salpichroa (Solanaceae).

'Gradual' vs 'punctuated' and 'unidirectional' (only lengthening) vs. 'bidirectional'(lengthenings and shortenings) modes of evolution are explanations that compete to explain adaptive changes of flower tube length in angiosperm. The nightshade genus Salpichroa Miers, with 21 species mostly growing in the tropical Andes of southern South America, has the opportune qualities of including nearly 15-fold inter-specific variation in corolla tube length, as well as one species that is a candidate for participating in evolutionary escalation with the longest-billed hummingbird, Ensifera ensifera. We reconstructed the phylogenetic relationships using five molecular markers, the two plastid markers trnD-trnT and trnL, and three nuclear markers, ITS and two COSII, and estimated divergence times of the genus in order to reconstruct the history of both corolla tube length and pollination mode (i.e. hummingbirds, moths or multiple). We used comparative methods to determine whether corolla tube elongation/shortening is associated with shifts in pollination mode and to test, modes and rates of corolla tube change. We found evidence of both lengthening and shortening of corolla tubes. Evolutionary rates are consistent with rapid corolla tube length transitions that are only partly associated with shifts in pollination mode. Though 'punctuated' evolution (i.e. large changes predominantly at speciation events) explained corolla changes in the whole genus, 'gradual' evolution (i.e. gradual changes during a coevolutionary race with the same pollinator) was a better explanation for the change in the long-flowered clade, mostly pollinated by hummingbirds.

Analysis of 14C-bearing compounds released by the corrosion of irradiated steel using accelerator mass spectrometry.

The combination of ion chromatography (IC) with accelerator mass spectrometry (AMS) was developed to determine the speciation of 14C-(radiocarbon) bearing organic compounds in the femto to pico molar concentration range. The development of this compound-specific radiocarbon analysis (CSRA) of carboxylic acids is reported and the application of the method on a leaching solution from neutron-irradiated steel is demonstrated. The background and the dynamic range of the AMS-based method were quantified. On using 14C-labelled standards, the measurements demonstrate the repeatability of the analytical method and the reproducible recovery of the main target carboxylic acids (i.e., acetate, formate, malonate, and oxalate). The detection limit was determined to be in the mid fmol 14C per L level while the dynamic range of the analytical method covers three orders of magnitude from the low fmol to the mid pmol 14C per L level. Cross contamination was found to be negligible during IC fractionation and was accounted for during eluate processing and 14C detection by AMS. The 14C-bearing carboxylates released from an irradiated steel nut into an alkaline leaching solution were analysed using the CSRA-based analytical method with the aim to check the applicability of the approach and develop appropriate sample preparation. The concentrations of 14C-bearing formate and acetate, the main organic corrosion products, were at a low pmol 14C per L level for convenient dimensions of the alkaline leaching experiment which demonstrates that compound-specific 14C AMS is an extremely sensitive analytical method for analysing 14C-bearing compounds. The content of total organic 14C in solution (TO14C) determined by the direct measurement of an aliquot of the leaching solution agrees well with the sum of the 14C concentrations of the individual carboxylates within the uncertainty of the data. Furthermore, the TO14C content is in good agreement with the calculated value using the corrosion rate determined from the 60Co release and the 14C inventory of the irradiated steel specimen.

Characterization of the Axial Jet Separator with a CO2/Helium Mixture: Toward GC-AMS Hyphenation.

Development of interfaces for sample introduction from high pressures is important for real-time online hyphenation of chromatographic and other separation devices with mass spectrometry (MS) or accelerator mass spectrometry (AMS). Momentum separators can reduce unwanted low-density gases and introduce the analyte into the vacuum. In this work, the axial jet separator, a new momentum interface, is characterized by theory and empirical optimization. The mathematical model describes the different axial penetration of the components of a jet-gas mixture and explains the empirical results for injections of CO2 in helium into MS and AMS instruments. We show that the performance of the new interface is sensitive to the nozzle size, showing good qualitative agreement with the mathematical model. Smaller nozzle sizes are more preferable due to their higher inflow capacity. The CO2 transmission efficiency of the interface into a MS instrument is ∼ 14% (CO2/helium separation factor of 2.7). The interface receives and delivers flows of ∼ 17.5 mL/min and ∼ 0.9 mL/min, respectively. For the interfaced AMS instrument, the ionization and overall efficiencies are 0.7-3% and 0.1-0.4%, respectively, for CO2 amounts of 4-0.6 µg C, which is only slightly lower compared to conventional systems using intermediate trapping. The ionization efficiency depends on to the carbon mass flow in the injected pulse and is suppressed at high CO2 flows. Relative to a conventional jet separator, the transmission efficiency of the axial jet separator is lower, but its performance is less sensitive to misalignments.

[Subsequent reoperation obstetric hysterectomy and selective ligation of hypogastric arteries]. / Reintervención posterior a histerectomía obstétrica y ligadura selectiva de arterias hipogástricas.

Background: Bleeding in pregnancy, childbirth or postpartum period is an emergency. Selective internal iliac (hypogastric) arteries ligation is a surgical therapy in selected cases of obstetric massive hemorrhage. It had proven to be safe. Objetive: To evaluate the risk for re-intervention for post-operatory bleeding in patients with obstetric hysterectomy and selective hypogastric arteries ligation. Material and method: Cross-sectional study including women diagnosed with obstetric hysterectomy with and without selective arterial ligation as a factor to assess the risk of re-intervention, from December 2013 to December 2014, at High Specialty Medical Unit 23 of Gynaecology and Obstetrics, in Monterrey, which is a tertiary care medical center. Those patients with 28 weeks of gestation or more were selected. The postoperative blood loss was quantified by open drainage system (Penrose). Results: We performed 88 hysterectomies in the study period. We included 45 women according to selection criteria. The average was 31.9 ± 5.48 years old. Performing a selective hypogastric arteries ligation may be a protective factor (p<0.05) for re-intervention as a consequence of postoperative bleeding. Conclusion: Selective arterial ligation is a factor that could help to prevent a re-intervention. A continuous training of physicians and residents of Gynecology and Obstetrics is essential to ensure the reduction in morbidity and maternal mortality.

Transcranial focal electrical stimulation via tripolar concentric ring electrodes does not modify the short- and long-term memory formation in rats evaluated in the novel object recognition test.

Noninvasive transcranial focal electrical stimulation (TFS) via tripolar concentric ring electrodes (TCREs) has been under development as an alternative/complementary therapy for seizure control. Transcranial focal electrical stimulation has shown efficacy in attenuating penicillin-, pilocarpine-, and pentylenetetrazole-induced acute seizures in rat models. This study evaluated the effects of TFS via TCREs on the memory formation of healthy rats as a safety test of TFS. Short- and long-term memory formation was tested after the application of TFS using the novel object recognition (NOR) test. The following independent groups were used: naïve, control (without TFS), and TFS (treated). The naïve, control, and stimulated groups spent more time investigating the new object than the familiar one during the test phase. Transcranial focal electrical stimulation via TCREs given once does not modify the short- and long-term memory formation in rats in the NOR test. Results provide an important step towards a better understanding for the safe usage of TFS via TCREs.

Installation of hybrid ion source on the 1-MV LLNL BioAMS spectrometer.

A second ion source was recently installed onto the LLNL 1-MV AMS spectrometer, which is dedicated to the quantification of 14C and 3H within biochemical samples. This source is unique among the other LLNL cesium sputter ion sources in that it can ionize both gaseous and solid samples. Also, the injection beam line has been designed to directly measure 14C/12C isotope ratios without the need for electrostatic bouncing. Preliminary tests show that this source can ionize transient CO2 gas pulses containing less than 1 ug carbon with approximately 1.5% efficiency. We demonstrate that the measured 14C/12C isotope ratio is largely unaffected by small drifts in the argon stripper gas density. We also determine that a tandem accelerating voltage of 670 kV enables the highest 14C transmission through the system. Finally, we describe a series of performance tests using solid graphite targets spanning nearly 3 orders in magnitude dynamic range and compare the results to our other ion source.

A new technique in the treatment of intestinal malrotation. / Una nueva técnica en el tratamiento de la malrotación intestinal.

INTRODUCTION: Intestinal malrotation is a congenital pathology with potentially catastrophic complications, such as volvulus, whose treatment has barely not changed in nearly 100 years (Ladd's procedure). Dr. Abu-Elmagd recently described a new technique that was applied in one of our patients. CLINICAL CASE: 12-year-old boy who had undergone Ladd's procedure as a result of intestinal volvulus secondary to malrotation when he was 2 days old. He had subocclusion and eventually obstruction, with intestinal volvulus compatible imaging. Intraoperative findings: duodenal subocclusion, volvulus and lymphangiectasias. Kareem's procedure: bowel positioning in normal rotation, duodenopexy (duodenal C posterior to the mesenteric vessels), formation of neo-Treitz, and fixation of the cecum, the ascending colon, and the mesenteric root. The patient was discharged on postoperative day 6 and remains asymptomatic after 1 year of follow-up. DISCUSSION: Kareem's procedure is a safe and effective malrotation repair technique. It can replace Ladd's procedure as it reduces the risk of re-volvulation and improves digestive symptoms.

INTRODUCCION: La malrotación intestinal es una patología congénita con complicaciones potencialmente catastróficas, destacando el vólvulo, cuyo tratamiento no ha variado significativamente en casi 100 años (procedimiento de Ladd). Recientemente el Dr. Abu-Elmagd describió una técnica que hemos aplicado en un paciente. CASO CLINICO: Varón de 12 años, intervenido con 2 días de vida por vólvulo intestinal secundario a malrotación realizándose procedimiento de Ladd. Presenta cuadros suboclusivos y finalmente obstructivo con imágenes compatibles con vólvulo intestinal. Hallazgos intraoperatorios: suboclusión duodenal, vólvulo y linfangiectasias. Procedimiento de Kareem: posicionando intestino en normorotación, duodenopexia (C duodenal posterior a vasos mesentéricos), formación de neoTreitz, fijación de ciego, colon ascendente y raíz mesentérica. Alta hospitalaria al 6º día postoperatorio, asintomático en 1 año de seguimiento. COMENTARIOS: El procedimiento de Kareem es una técnica segura y efectiva que corrige la malrotación, pudiendo reemplazar al procedimiento de Ladd al disminuir el riesgo de revolvulación y mejorar síntomas digestivos.

Impact of the COVID-19 pandemic on the mental health of the general population and health care workers.

The Health Sciences Foundation has assembled a multidisciplinary group around a series of questions about the impact of the COVID-19 pandemic on the mental health of the general population and specific groups within that population, particularly healthcare workers. In the general population, the most prevalent mental disorders have been anxiety, sleep disorders and affective disorders, primarily depression. There has been a considerable increase in suicidal behavior, especially in young women and men over 70 years of age. There has been an increase in alcohol abuse and nicotine, cannabis and cocaine use. In contrast, the use of synthetic stimulants during periods of confinement has decreased. With regard to non-substance addictions, gambling was very limited, pornography consumption increased significantly and there was an increase in compulsive shopping and the use of video games. Particularly vulnerable groups include adolescents and patients with autism spectrum disorders. Healthcare workers suffered an increase in depression, anxiety and post-traumatic stress, especially those who were exposed during the early stages of the pandemic. Female sex, being a nurse, proximity to patients with COVID-19, working in a rural environment and having previous psychiatric or organic illnesses were some of the most frequently repeated factors in various studies in this population group. The media have shown a good degree of knowledge about these problems and have dealt with them frequently and from the point of view of ethics, crisis situations, such as the one experienced, have triggered not only physical but also moral claudications.

Core content for venous and Lymphatic Medicine: 2022 revision.

The core content for a medical specialty outlines the scope of the discipline as well as the categories of knowledge considered essential to practice in the field. It provides a template for the development of curricula for medical school, graduate, and postgraduate education, as well as for creating certification standards. Venous and Lymphatic Medicine (VLM) is a specialty that has benefitted from contributions from specialists from several medical disciplines. Optimally, the societies, boards, and residency review committees representing these disciplines would uniformly recognize the scope of VLM to develop education and assessment standards to allow training and identification of qualified practitioners. In order to inform the standard setting bodies and other stakeholders of the current scope of VLM, a task force of VLM experts from cardiology, dermatology, emergency medicine, general surgery, interventional radiology, vascular medicine, and vascular surgery was formed to revise a 2014 consensus document defining the core content of the specialty of VLM.

Prevalence of pulmonary hypertension in COPD patients living at high altitude.

BACKGROUND: Pulmonary hypertension (PH) is associated with poor prognosis for patients with chronic obstructive pulmonary disease (COPD). Most of the knowledge about PH in COPD has been generated at sea level, with limited information associated with high altitude (HA). OBJECTIVES: To assess the prevalence and severity of PH in COPD patients living in a HA city (2,640 m). METHODS: Cross-sectional study in COPD patients with forced expiratory volume in the first second / forced vital capacity ratio (FEV1/FVC) post-bronchodilator <0,7. Transthoracic echocardiography (TTE), spirometry, carbon monoxide diffusing capacity, and arterial blood gasses tests were performed. Patients were classified according to the severity of airflow limitation. PH was defined by TTE as an estimated systolic pulmonary artery pressure (sPAP) > 36 mmHg or indirect PH signs; severe PH as sPAP > 60 mmHg; and disproportionate PH as an sPAP > 60 mmHg with non-severe airflow limitation (FEV1 > 50% predicted). RESULTS: We included 176 COPD patients. The overall estimated prevalence of PH was 56.3% and the likelihood of having PH increased according to airflow-limitation severity: mild (31.6%), moderate (54.9%), severe (59.6%) and very severe (77.8%) (p = 0.038). The PH was severe in 7.3% and disproportionate in 3.4% of patients. CONCLUSIONS: The estimated prevalence of PH in patients with COPD at HA is high, particularly in patients with mild to moderate airflow limitation, and greater than that described for COPD patients at low altitude. These results suggest a higher risk of developing PH for COPD patients living at HA compared to COPD patients with similar airflow limitation living at low altitude.

Temperature adaptation markedly determines evolution within the genus Saccharomyces.

The present study uses a mathematical-empirical approach to estimate the cardinal growth temperature parameters (T(min), the temperature below which growth is no longer observed; T(opt), the temperature at which the µ(max) equals its optimal value; µ(opt), the optimal value of µ(max); and T(max), the temperature above which no growth occurs) of 27 yeast strains belonging to different Saccharomyces and non-Saccharomyces species. S. cerevisiae was the yeast best adapted to grow at high temperatures within the Saccharomyces genus, with the highest optimum (32.3°C) and maximum (45.4°C) growth temperatures. On the other hand, S. kudriavzevii and S. bayanus var. uvarum showed the lowest optimum (23.6 and 26.2°C) and maximum (36.8 and 38.4°C) growth temperatures, respectively, confirming that both species are more psychrophilic than S. cerevisiae. The remaining Saccharomyces species (S. paradoxus, S. mikatae, S. arboricolus, and S. cariocanus) showed intermediate responses. With respect to the minimum temperature which supported growth, this parameter ranged from 1.3 (S. cariocanus) to 4.3°C (S. kudriavzevii). We also tested whether these physiological traits were correlated with the phylogeny, which was accomplished by means of a statistical orthogram method. The analysis suggested that the most important shift in the adaptation to grow at higher temperatures occurred in the Saccharomyces genus after the divergence of the S. arboricolus, S. mikatae, S. cariocanus, S. paradoxus, and S. cerevisiae lineages from the S. kudriavzevii and S. bayanus var. uvarum lineages. Finally, our mathematical models suggest that temperature may also play an important role in the imposition of S. cerevisiae versus non-Saccharomyces species during wine fermentation.

[Massive rotator cuff injury: arthroscopic treatment with upper capsular reconstruction]. / Lesión masiva del manguito rotador: tratamiento artroscópico con reconstrucción capsular superior.

Massive rotator cuff injuries (LMMRs) are those breaks of more than 5 cm either the anteroposterior plane, or lateromedial plane. Some authors consider them to be complete ruptures of at least two rotator cuff tendons. The clinical case of a 63-year-old man with this type of injury that was resolved by the superior capsule reconstruction technique is presented, technical details and some of the literature review to carry out the procedure are shown.

Las lesiones masivas del manguito rotador (LMMR) son aquellas roturas de más de 5 cm ya sea el plano anteroposterior o lateromedial. Algunos autores las consideran como roturas completas de al menos dos tendones del maguito rotador. Se presenta el caso clínico de un varón de 63 años con este tipo de lesión que se resolvió mediante la técnica de reconstrucción de cápsula superior, se muestran detalles técnicos y un poco de la revisión de la literatura para llevar a cabo el procedimiento.

BLOC-1 complex deficiency alters the targeting of adaptor protein complex-3 cargoes.

Mutational analyses have revealed many genes that are required for proper biogenesis of lysosomes and lysosome-related organelles. The proteins encoded by these genes assemble into five distinct complexes (AP-3, BLOC-1-3, and HOPS) that either sort membrane proteins or interact with SNAREs. Several of these seemingly distinct complexes cause similar phenotypic defects when they are rendered defective by mutation, but the underlying cellular mechanism is not understood. Here, we show that the BLOC-1 complex resides on microvesicles that also contain AP-3 subunits and membrane proteins that are known AP-3 cargoes. Mouse mutants that cause BLOC-1 or AP-3 deficiencies affected the targeting of LAMP1, phosphatidylinositol-4-kinase type II alpha, and VAMP7-TI. VAMP7-TI is an R-SNARE involved in vesicle fusion with late endosomes/lysosomes, and its cellular levels were selectively decreased in cells that were either AP-3- or BLOC-1-deficient. Furthermore, BLOC-1 deficiency selectively altered the subcellular distribution of VAMP7-TI cognate SNAREs. These results indicate that the BLOC-1 and AP-3 protein complexes affect the targeting of SNARE and non-SNARE AP-3 cargoes and suggest a function of the BLOC-1 complex in membrane protein sorting.

Food availability and reproduction affects lipid and fatty acid composition of the brown mussel, Perna perna, raised in suspension culture.

We examined the influence of the reproductive cycle and environmental factors on variations of the condition index (CI), tissue dry mass, shell size, total lipid content, and relative percent of fatty acids in the mussel, Perna perna. Spat or juveniles were reared to commercial size (70 mm) in suspension culture in the Golfo de Cariaco, Venezuela between May and October 2004. The dry mass of soft tissues and shell, a visual assessment of gonadal status and the organism lipid profile were established every fortnight. In parallel, we measured the environmental conditions, following chlorophyll a, salinity, temperature and seston levels. After an initial decrease, the CI rose and remained high until August after which it decreased continuously until October. Total lipid values also decreased initially, after which they showed two periods of rapid recuperation and depletion, the first between May and August and the second between August and October. Similar tendencies were noted in the fatty acids, C18:3n-3, C18:4n-3 and C22:6n-3. Correlation analysis found no significant relationships between environmental parameters and the variations in total lipids. However, significant correlations were noted between fatty acids and specific environmental parameters. In particular, temperature was inversely correlated with C14:0, C16:1n-7, C18:0, C18:1n-9 and 20:5n-3. Chlorophyll a was positively correlated with C14:0, C16:1n-7, C18:1n-7, C18:4n-3 and 20:4n-6. On the other hand, gametogenesis had an effect on C14:0, C16:1n-7, C18:1n-9 and C18:1n-7, while spawned and gonadal regression states had an effect on fatty acid 20:4n-6. Temperature and chlorophyll a levels strongly influenced the proportion of mussels spawning, suggesting that their influence upon lipid composition may be secondary to their impact upon reproduction. Despite the thermal stability of this tropical system, the lipid composition of mussels changed markedly during the study, reflecting the central role of diet and reproductive investment upon lipid composition.

Systemic inflammation, endothelial dysfunction, and activation in clinically healthy children exposed to air pollutants.

Mexico City children are chronically exposed to significant concentrations of air pollutants and exhibit chronic respiratory-tract inflammation. Epidemiological, controlled human exposures, laboratory-based animal models, and in vitro/in vivo studies have shown that inflammatory, endothelial dysfunction, and endothelial damage mediators are upregulated upon exposure to particulate matter (PM). Endothelial dysfunction is a critical event in cardiovascular disease. The focus of this work was to investigate whether exposure to ambient air pollution including PM(2.5) produces systemic inflammation and endothelial injury in healthy children. We measured markers of endothelial activation, and inflammatory mediators in 52 children age 8.6+/-0.1 yr, residents of Mexico City (n: 28) or of Polotitlán (n: 24), a city with low levels of pollutants. Mexico City children had significant increases in inflammatory mediators and vasoconstrictors, including tumor necrosis factor (TNF)alpha, prostaglandin (PG) E2, C-reactive protein, interleukin-1beta, and endothelin-1. There was a significant anti-inflammatory response, and a downregulation of vascular adhesion molecule-1, intercellular adhesion molecule-1 and -2, and selectins sE and sL. Results from linear regression found TNF a positively associated with 24- and 48-h cumulative levels of PM(2.5), while the 7-d PM(2.5) value was negatively associated with the numbers of white blood cells in peripheral blood in highly exposed children. Systemic subclinical inflammation, increased endothelin- 1, and significant downregulation of soluble adhesion molecules are seen in Mexico City children. Children chronically exposed to fine PM above the standard could be at risk of developing cardiovascular diseases, atherosclerosis, stroke, and other systemic effects later in life.

Family interactions of liver transplanted children: are they normal?

Several psychosocial and behavioral problems have been reported in liver transplanted children. Most publications have focused on them, without considering their family environment. The aim of this study was to evaluate the interaction between liver transplanted children and their families, compared with a healthy control group. We selected liver transplanted children, between 8 and 12 years of age, with at least 6 months follow-up posttransplantation and in good clinical condition. Family structure also included 1 to 3 other children. Evaluable patients must have been living with their parents throughout the whole posttransplantation period. They were compared with a similar group of children without any chronic disease. A written informed consent was signed by both parents. All families were evaluated using a standard test consisting of different situations. The information was evaluated by 3 independent experts. Factors evaluated were limits (rules and limits of behavior), alliance-opposition (interaction between members to act), and hierarchy. Scoring was given to all observed acts. Statistical analysis was performed using chi-square tests with P < .05 considered significant. No statistical differences were found between groups in limits, alliance, and hierarchy. Our results showed that there were no differences in family structure and behavior between families of liver-transplanted and healthy children belonging to a similar socioeconomic level.