Incidence of major cardiovascular events at 1, 2, and 5 years and mortality in incident patients on peritoneal dialysis regarding their nutritional status by bioimpedanciometry: A multicenter study in Colombia.

BACKGROUND: The nutritional status of incident patients on peritoneal dialysis (PD) has been associated with survival outcomes. Bioimpedanciometry (BCM) enables to establish a nutritional diagnosis, the volume status, and correlates these findings with survival. METHODS: This study used a retrospective multicenter historical cohort. RESULTS: In this study, which included 420 incident patients on peritoneal dialysis with a 5-year follow-up, a cumulative incidence of major adverse cardiovascular events (MACE) of 28.8% was found, being higher in the diabetic population at 36.8%. In regard to the nutritional status in this population, it was found that approximately 44% had altered nutritional status; 34% were found to be in sarcopenia; 6.7% sarcopenic obesity; and 2.8% in obesity (p < 0.001). In the survival analysis, a lower probability of survival was found in patients with overhydration (OH) greater than 3 L (p < 0.001) and in patients with altered nutritional status due to sarcopenia, sarcopenic obesity, and obesity (p 0.016). According to survival in the subgroup of the diabetic population, a lower probability of survival was found in this group of patients (p: 0.011). The overall mortality of the study population was 18%, being higher in the first 2 years, with the most important causes of mortality being cardiovascular. Of the deceased population, 51% were diabetic patients (p: 0.012). CONCLUSION: In incident patients on peritoneal dialysis, sarcopenic obesity, sarcopenia, overhydration status determined by BCM, and having a diagnosis of diabetes are related to a lower probability of survival; MACE outcomes are more frequent in the diabetic population.

Ptr1 and ZAR1 immune receptors confer overlapping and distinct bacterial pathogen effector specificities.

Some nucleotide-binding and leucine-rich repeat receptors (NLRs) indirectly detect pathogen effectors by monitoring their host targets. In Arabidopsis thaliana, RIN4 is targeted by multiple sequence-unrelated effectors and activates immune responses mediated by RPM1 and RPS2. These effectors trigger cell death in Nicotiana benthamiana, but the corresponding NLRs have yet not been identified. To identify N. benthamiana NLRs (NbNLRs) that recognize Arabidopsis RIN4-targeting effectors, we conducted a rapid reverse genetic screen using an NbNLR VIGS library. We identified that the N. benthamiana homolog of Ptr1 (Pseudomonas tomato race 1) recognizes the Pseudomonas effectors AvrRpt2, AvrRpm1, and AvrB. We demonstrated that recognition of the Xanthomonas effector AvrBsT and the Pseudomonas effector HopZ5 is conferred independently by the N. benthamiana homolog of Ptr1 and ZAR1. Interestingly, the recognition of HopZ5 and AvrBsT is contributed unequally by Ptr1 and ZAR1 in N. benthamiana and Capsicum annuum. In addition, we showed that the RLCK XII family protein JIM2 is required for the NbZAR1-dependent recognition of AvrBsT and HopZ5. The recognition of sequence-unrelated effectors by NbPtr1 and NbZAR1 provides an additional example of convergently evolved effector recognition. Identification of key components involved in Ptr1 and ZAR1-mediated immunity could reveal unique mechanisms of expanded effector recognition.

Post-Intensive Care Unit Multidisciplinary Approach in Patients with Severe Bilateral SARS-CoV-2 Pneumonia.

Background: Short and long-term sequelae after admission to the intensive care unit (ICU) for coronavirus disease 2019 (COVID-19) are to be expected, which makes multidisciplinary care key in the support of physical and cognitive recovery. Objective: To describe, from a multidisciplinary perspective, the sequelae one month after hospital discharge among patients who required ICU admission for severe COVID-19 pneumonia. Design: Prospective cohort study. Environment: Multidisciplinary outpatient clinic. Population: Patients with severe COVID-19 pneumonia, post- ICU admission. Methods: A total of 104 patients completed the study in the multidisciplinary outpatient clinic. The tests performed included spirometry, measurement of respiratory muscle pressure, loss of body cell mass (BCM) and BCM index (BCMI), general joint and muscular mobility, the short physical performance battery (SPPB or Guralnik test), grip strength with hand dynamometer, the six-minute walk test (6-MWT), the functional assessment of chronic illness therapy-fatigue scale (FACIT-F), the European quality of life-5 dimensions (EQ-5D), the Barthel index and the Montreal cognitive assessment test (MoCA). While rehabilitation was not necessary for 23 patients, 38 patients attended group rehabilitation sessions and other 43 patients received home rehabilitation. Endpoints: The main sequelae detected in patients were fatigue (75.96%), dyspnoea (64.42%) and oxygen therapy on discharge (37.5%). The MoCA showed a mean score compatible with mild cognitive decline. The main impairment of joint mobility was limited shoulder (11.54%) and shoulder girdle (2.88%) mobility; whereas for muscle mobility, lower limb limitations (16.35%) were the main dysfunction. Distal neuropathy was present in 23.08% of patients, most frequently located in lower limbs (15.38%). Finally, 50% of patients reported moderate limitation in the EQ-5D, with a mean score of 60.62 points (SD 20.15) in perceived quality of life. Conclusions: Our findings support the need for a multidisciplinary and comprehensive evaluation of patients after ICU admission for COVID-19 because of the wide range of sequelae, which also mean that these patients need a long-term follow-up. Impact on clinical rehabilitation: This study provides data supporting the key role of rehabilitation during the follow-up of severe patients, thus facilitating their reintegration in society and a suitable adaptation to daily living.

Ptr1 evolved convergently with RPS2 and Mr5 to mediate recognition of AvrRpt2 in diverse solanaceous species.

The Ptr1 (Pseudomonas tomato race 1) locus in Solanum lycopersicoides confers resistance to strains of Pseudomonas syringae pv. tomato expressing AvrRpt2 and Ralstonia pseudosolanacearum expressing RipBN. Here we describe the identification and phylogenetic analysis of the Ptr1 gene. A single recombinant among 585 F2 plants segregating for the Ptr1 locus was discovered that narrowed the Ptr1 candidates to eight nucleotide-binding leucine-rich repeat protein (NLR)-encoding genes. From analysis of the gene models in the S. lycopersicoides genome sequence and RNA-Seq data, two of the eight genes emerged as the strongest candidates for Ptr1. One of these two candidates was found to encode Ptr1 based on its ability to mediate recognition of AvrRpt2 and RipBN when it was transiently expressed with these effectors in leaves of Nicotiana glutinosa. The ortholog of Ptr1 in tomato and in Solanum pennellii is a pseudogene. However, a functional Ptr1 ortholog exists in Nicotiana benthamiana and potato, and both mediate recognition of AvrRpt2 and RipBN. In apple and Arabidopsis, recognition of AvrRpt2 is mediated by the Mr5 and RPS2 proteins, respectively. Phylogenetic analysis places Ptr1 in a distinct clade compared with Mr5 and RPS2, and it therefore appears to have arisen by convergent evolution for recognition of AvrRpt2.

Establishing Mayo Clinic's Coronavirus Disease 2019 Virtual Clinic: A Preliminary Communication.

The coronavirus disease 2019 (COVID-19) pandemic is taking a massive toll on health care systems globally. We developed the COVID-19 virtual clinic (CVC) in conjunction with drive through testing to cope with this situation. There are two arms of the CVC: (1) a screening arm and (2) positive patient arm. Screening is performed over the phone based on the Centers for Disease Control and Prevention screening guideline. Positive patients are followed at regular intervals by video appointments where concerns can be addressed by a provider while also tracking symptom progression. We enrolled 63 positive patients out of 1,153 screened for COVID-19 as of this writing. The CVC continues to address patients' concerns and symptoms in an effort to minimize emergency department and hospital patient volumes, as incidence increases. Drive through testing in conjunction with a virtual clinic allows us to provide high-quality care in an anxious time without consuming excessive personal protective equipment or unnecessarily exposing health care workers. This article could serve as a model to guide other practices to cope with this and future pandemics.

The Ptr1 Locus of Solanum lycopersicoides Confers Resistance to Race 1 Strains of Pseudomonas syringae pv. tomato and to Ralstonia pseudosolanacearum by Recognizing the Type III Effectors AvrRpt2 and RipBN.

Race 1 strains of Pseudomonas syringae pv. tomato, which cause bacterial speck disease of tomato, are becoming increasingly common and no simply inherited genetic resistance to such strains is known. We discovered that a locus in Solanum lycopersicoides, termed Pseudomonas tomato race 1 (Ptr1), confers resistance to race 1 P. syringae pv. tomato strains by detecting the activity of type III effector AvrRpt2. In Arabidopsis, AvrRpt2 degrades the RIN4 protein, thereby activating RPS2-mediated immunity. Using site-directed mutagenesis of AvrRpt2, we found that, like RPS2, activation of Ptr1 requires AvrRpt2 proteolytic activity. Ptr1 also detected the activity of AvrRpt2 homologs from diverse bacteria, including one in Ralstonia pseudosolanacearum. The genome sequence of S. lycopersicoides revealed no RPS2 homolog in the Ptr1 region. Ptr1 could play an important role in controlling bacterial speck disease and its future cloning may shed light on an example of convergent evolution for recognition of a widespread type III effector.

Pseudomonas syringae pv. tomato Strains from New York Exhibit Virulence Attributes Intermediate Between Typical Race 0 and Race 1 Strains.

Bacterial speck disease, caused by Pseudomonas syringae pv. tomato, is a persistent problem for fresh-market tomato growers in New York. Race 0 strains of this pathogen express either or both of the type III effectors AvrPto or AvrPtoB, which are recognized by tomato varieties expressing the Pto resistance gene. Pto encodes a protein kinase that activates the host immune system, thereby inhibiting bacterial multiplication and preventing disease development. Race 1 P. syringae pv. tomato strains do not express these effectors and are virulent on tomato whether or not the variety expresses Pto. Very few fresh-market tomato varieties have the Pto gene. We collected six P. syringae pv. tomato strains from naturally infected tomato plants across New York in 2015 and characterized them for their virulence and for the presence of specific effectors. In experiments conducted in the greenhouse, all strains reached population sizes in Pto-expressing tomato leaves that were intermediate between typical race 0 and race 1 strains. This phenotype has not been observed previously and suggests that the strains are recognized by Pto but such recognition is compromised by another P. syringae pv. tomato factor. The strains were found to encode avrPto, which is transcribed and translated. They also express avrPtoB although, as reported for other P. syringae pv. tomato strains, protein expression for this effector was not detectable. Deletion of avrPto from a representative New York strain allowed it to reach high populations in Pto-expressing tomato varieties, without compromising its virulence on susceptible tomato plants. Collectively, our data suggest that introgression of the Pto gene into fresh-market tomato varieties could enhance protection against extant P. syringae pv. tomato strains.

Particulate matter levels in a South American megacity: the metropolitan area of Lima-Callao, Peru.

The temporal and spatial trends in the variability of PM10 and PM2.5 from 2010 to 2015 in the metropolitan area of Lima-Callao, Peru, are studied and interpreted in this work. The mean annual concentrations of PM10 and PM2.5 have ranges (averages) of 133-45 µg m-3 (84 µg m-3) and 35-16 µg m-3 (26 µg m-3) for the monitoring sites under study. In general, the highest annual concentrations are observed in the eastern part of the city, which is a result of the pattern of persistent local winds entering from the coast in a south-southwest direction. Seasonal fluctuations in the particulate matter (PM) concentrations are observed; these can be explained by subsidence thermal inversion. There is also a daytime pattern that corresponds to the peak traffic of a total of 9 million trips a day. The PM2.5 value is approximately 40% of the PM10 value. This proportion can be explained by PM10 re-suspension due to weather conditions. The long-term trends based on the Theil-Sen estimator reveal decreasing PM10 concentrations on the order of -4.3 and -5.3% year-1 at two stations. For the other stations, no significant trend is observed. The metropolitan area of Lima-Callao is ranked 12th and 16th in terms of PM10 and PM2.5, respectively, out of 39 megacities. The annual World Health Organization thresholds and national air quality standards are exceeded. A large fraction of the Lima population is exposed to PM concentrations that exceed protection thresholds. Hence, the development of pollution control and reduction measures is paramount.

[Prevalence of specific antibodies for celiac disease in children attended in the Nutritional Recovery Program in San Miguel de Tucumán, Argentina]. / Prevalencia de anticuerpos específicos para enfermedad celíaca en niños del Programa de Rehabilitación Nutricional en San Miguel de Tucumán, Argentina.

Celiac disease is a systemic autoimmune disease that affects 1.26% of the Argentine pediatric population. Our purpose was to study the prevalence of specific antibodies of celiac disease in a risk group and to find the association with specific factors. This was a cross-sectional study conducted in children ofa Nutritional Recovery Program from 1 year and 9 months to 6 years and 9 months old, from one Health Area of Tucumán Province, during 2010 and 2011, in a random cluster sample. It was studied a population of 175 children. We identified 3 cases with positive serology, equivalent to 1.7% of the study population. The association between cases with positive serology for celiac disease and other variables referred could not be established.

Bioactivity of synthetic peptides from Ecuadorian frog skin secretions against Leishmania mexicana, Plasmodium falciparum, and Trypanosoma cruzi.

Chagas disease, leishmaniasis, and malaria are major parasitic diseases disproportionately affecting the underprivileged population in developing nations. Finding new, alternative anti-parasitic compounds to treat these diseases is crucial because of the limited number of options currently available, the side effects they cause, the need for long treatment courses, and the emergence of drug-resistant parasites. Anti-microbial peptides (AMPs) derived from amphibian skin secretions are small bioactive molecules capable of lysing the cell membrane of pathogens while having low toxicity against human cells. Here, we report the anti-parasitic activity of five AMPs derived from skin secretions of three Ecuadorian frogs: cruzioseptin-1, cruzioseptin-4 (CZS-4), and cruzioseptin-16 from Cruziohyla calcarifer; dermaseptin-SP2 from Agalychnis spurrelli; and pictuseptin-1 from Boana picturata. These five AMPs were chemically synthesized. Initially, the hemolytic activity of CZS-4 and its minimal inhibitory concentration against Escherichia coli, Staphylococcus aureus, and Candida albicans were determined. Subsequently, the cytotoxicity of the synthetic AMPs against mammalian cells and their anti-parasitic activity against Leishmania mexicana promastigotes, erythrocytic stages of Plasmodium falciparum and mammalian stages of Trypanosoma cruzi were evaluated in vitro. The five AMPs displayed activity against the pathogens studied, with different levels of cytotoxicity against mammalian cells. In silico molecular docking analysis suggests this bioactivity may occur via pore formation in the plasma membrane, resulting in microbial lysis. CZS-4 displayed anti-bacterial, anti-fungal, and anti-parasitic activities with low cytotoxicity against mammalian cells. Further studies about this promising AMP are required to gain a better understanding of its activity.IMPORTANCEChagas disease, malaria, and leishmaniasis are major tropical diseases that cause extensive morbidity and mortality, for which available treatment options are unsatisfactory because of limited efficacy and side effects. Frog skin secretions contain molecules with anti-microbial properties known as anti-microbial peptides. We synthesized five peptides derived from the skin secretions of different species of tropical frogs and tested them against cultures of the causative agents of these three diseases, parasites known as Trypanosoma cruzi, Plasmodium falciparum, and Leishmania mexicana. All the different synthetic peptides studied showed activity against one of more of the parasites. Peptide cruzioseptin-4 is of special interest since it displayed intense activity against parasites while being innocuous against cultured mammalian cells, which indicates it does not simply hold general toxic properties; rather, its activity is specific against the parasites.

The oxidative potential of airborne particulate matter in two urban areas of Chile: More than meets the eye.

Oxidative potential (OP) has gained attention as a parameter that can reveal the ability of different properties of particulate matter (PM) to generate reactive oxygen species (ROS) as one single value. Moreover, OP is also believed to be a predictor of toxicity and hence the health effects of PM. This study evaluated the OP of PM10, PM2.5,and PM1.0samples using dithiothreitol assays in two cities of Chile (Santiago and Chillán). The results showed that the OP was different between cities, PM size fractions, and seasons. Additionally, OP was strongly correlated with certain metals and meteorological variables. Higher mass-normalized OP was observed during cold periods in Chillán and warm periods in Santiago and was associated with PM2.5 and PM1. On the other hand, volume-normalized OP was higher during winter in both cities and for PM10. Additionally, we compared the OP values to the Air Quality Index (AQI) scale and found cases of days that were classified as having "good" air quality (supposed to be less harmful to health) showing extremely high OP values that were similar to those on days that were classified as "unhealthy". Based on these results,we suggest using the OP as a complementary measure to the PM mass concentration because it includes important new information related to PM properties and compositions that could help improvecurrent air quality management tools.

Modulation of the activation of endothelial nitric oxide synthase and nitrosative stress biomarkers by aspirin triggered lipoxins: A possible mechanism of action of aspirin in the antiphospholipid syndrome.

PROBLEM: Antiphospholipid syndrome (APS) is characterized by the clinical manifestation of vascular thrombosis (VT) or pregnancy morbidity (PM) and antiphospholipid antibodies (aPL) that can modify the nitric oxide production. Low-dose aspirin is used in the prevention and treatment of diverse alterations of pregnancy. One of the mechanisms of action of aspirin is to induce the production of aspirin-triggered-lipoxins (ATL). The aim of this study was to evaluate the modulatory effect of ATL over the activation of endothelial nitric oxide synthase (eNOS) and nitrosative stress biomarkers induced by aPL. METHODS: We used polyclonal IgG and sera from women with aPL and PM/VT or VT only, and from women with PM only and positive for non-criteria aPL (SN-OAPS). In these sera, biomarkers of nitrosative stress (nitrites and nitrotyrosine) were measured. The protein expression of nitrotyrosine and the phosphorylation of eNOS (at Ser1177) were estimated in human umbilical vein endothelial cells (HUVECs) stimulated with polyclonal IgG with or without ATL. RESULTS: Women with SN-OAPS showed increased circulating levels of nitrites and nitrotyrosine. Likewise, polyclonal IgG from either SN-OAPS or VT patients stimulated nitrotyrosine expression in HUVECs. ATL decreased the nitrotyrosine expression induced by polyclonal IgG from the SN-OAPS group. ATL also recovered the reduced eNOS phosphorylation at Ser1177 in HUVECs stimulated with polyclonal IgG from women with PM/VT or SN-OAPS. CONCLUSIONS: Increased nitrosative stress present in serum of women with SN-OAPS is associated with IgG-mediated impaired endothelial NO synthesis in endothelial cells. ATL prevent these cellular changes.

Discovery and validation of dominantly inherited Alzheimer's disease mutations in populations from Latin America.

BACKGROUND: In fewer than 1% of patients, AD is caused by autosomal dominant mutations in either the presenilin 1 (PSEN1), presenilin 2 (PSEN2), or amyloid precursor protein (APP) genes. The full extent of familial AD and frequency of these variants remains understudied in Latin American (LatAm) countries. Due to the rare nature of these variants, determining the pathogenicity of a novel variant in these genes can be challenging. Here, we use a systematic approach to assign the likelihood of pathogenicity in variants from densely affected families in Latin American populations. METHODS: Clinical data was collected from LatAm families at risk for DIAD. Symptomatic family members were identified and assessed by local clinicians and referred for genetic counseling and testing. To determine the likelihood of pathogenicity among variants of unknown significance from LatAm populations, we report pedigree information, frequency in control populations, in silico predictions, and cell-based models of amyloid-beta ratios. RESULTS: We identified five novel variants in the presenilin1 (PSEN1) gene from Brazilian and Mexican families. The mean age at onset in newly identified families was 43.5 years (range 36-54). PSEN1 p.Val103_Ser104delinsGly, p.Lys395Ile, p.Pro264Se, p.Ala275Thr, and p.Ile414Thr variants have not been reported in PubMed, ClinVar, and have not been reported in dominantly inherited AD (DIAD) families. We found that PSEN1 p.Val103_Ser104delinsGly, p.Lys395Ile, p.Pro264Se, and p.Ala275Thr produce Aß profiles consistent with known AD pathogenic mutations. PSEN1 p.Ile414Thr did not alter Aß in a manner consistent with a known pathogenic mutation. CONCLUSIONS: Our study provides further insights into the genetics of AD in LatAm. Based on our findings, including clinical presentation, imaging, genetic, segregations studies, and cell-based analysis, we propose that PSEN1 p.Val103_Ser104delinsGly, p.Lys395Ile, p.Pro264Se, and p.Ala275Thr are likely pathogenic variants resulting in DIAD, whereas PSEN1 p.Ile414Thr is likely a risk factor. This report is a step forward to improving the inclusion/engagement of LatAm families in research. Family discovery is of great relevance for the region, as new initiatives are underway to extend clinical trials and observational studies to families living with DIAD.

Local Air Quality Issues and Research Priorities Through the Lenses of Chilean Experts: An Ontological Analysis.

Air pollution problems can be large, complex, and ill-structured. They can vary from location to location and combine many complex components: urban expansion, increasing vehicles and industrial emissions, biomass burning, geographic and meteorological conditions, cultural aspects, and economic effects. However, the existing research, accumulated knowledge, and local research priorities are spread over many disciplines and lack a systematic mapping to help manage and develop new strategies for researchers and policy makers. Ontological analysis can be used as a tool to capture this complexity through simple natural-language descriptions and a structured terminology. We describe the development of an ontological framework for "Air Quality Management in Chile" and its application to evaluate the current state of the research. The process was based on focus groups and validated by a panel of multidisciplinary experts. We used the developed framework to highlight the topics that have been heavily emphasized, lightly emphasized, or overlooked in the Chilean research. The framework developed can help researchers, practitioners, and policy makers systematically navigate the domain and provide the opportunity to correct blind spots by enabling more informed hypotheses that deal with air quality issues at a national level. We believe that applying this same process to different countries will yield different results (due to differences in local knowledge and experience). The framework presented could be used to evaluate other important stakeholders (government, media, NGOs, etc.), which will provide a complete picture of how local societies deal with air quality issues at different levels. Additionally, local government institutions will benefit from this analysis by improving funding allocation and opening new research opportunities to improve the distribution of the local body of knowledge. Integr Environ Assess Manag 2021;17:273-281. © 2020 SETAC.

Impact of an RN-led Medicare Annual Wellness Visit on Preventive Services in a Family Medicine Practice.

OBJECTIVE: To evaluate the impact of a registered nurse (RN)-led Medicare annual wellness visit (AWV) on preventive services in a family medicine clinic. PATIENTS AND METHODS: A retrospective chart review was performed on patients who underwent an RN-led AWV and patients who underwent a standard assessment (SA) between October 2017 and October 2018. A total of 630 patients (330 AWV and 300 SA) were included in this study. RESULTS: There were seven preventive services examined for in women and five preventive services examined for in men. Each service was used more often by patients in the AWV group than the SA group (all odds ratios ≥1.64; all P values ≤.004). CONCLUSION: The RN-led AWV is an effective way to assist Medicare beneficiaries in meeting their preventive needs while allowing physicians more time to focus on chronic and acute needs.

Obstetric Antiphospholipid Syndrome: An Approach from Glycans of the Immunoglobulin G.

This is a case report of women with pregnancy morbidity (PM), some of them associated with antiphospholipid syndrome (APS), in which the glycan patterns of immunoglobulin G (IgG) were investigated based on the theory of alteration of glycosylation in autoimmunity. We used lectin blot to determine changes in terminal glycosylation of polyclonal IgG from women with antiphospholipid (aPL) antibodies and PM plus vascular thrombosis (PM/VT) and seronegative-obstetric APS (SN-OAPS). In addition, we analyzed IgG from women with PM without aPL (PM/aPL-) and healthy women, as controls. Even though the SN-OAPS and PM/VT groups share the PM, only the SN-OAPS group showed a decreased expression of galactose compared to the healthy group. We also found the presence of mannosylated oligosaccharides in IgG from all patients being significantly higher in IgG from women of the PM/aPL- group. The differences in glycans presented here could relate to pathological mechanisms of PM associated with APS.

Cervical Spine Evaluation by Telephone and Video Visit.

As telecommunication technologies advance, efforts are being made to mitigate direct patient contact in the COVID-19 pandemic due to the risk of contagion. The ability to host telephone and video visits within patient portals within health care institutions will only become increasingly valuable. Neck pain, a common complaint seen in primary care clinics, is well-suited to telemedicine evaluation, as related etiologies are often comparatively straightforward. A good assessment of the cervical spine by telephone or video is possible with the right knowledge and practice. The purpose of this article is to propose questions and maneuvers that can be used to evaluate the cervical spine via telephone or video, as well as likely diagnoses that can be reached through these. Phone and video evaluation of the cervical spine can result in valuable data regarding symmetry, range of motion, functional movement patterns, modified strength testing, and provocative testing. The skill set necessary to do telephone and video visits should be included in the curriculum of physician learners.

Trace determination of sulfonylurea herbicides in water and grape samples by capillary zone electrophoresis using large volume sample stacking.

A sensitive and reliable method using capillary zone electrophoresis with UV-diode array detection has been developed and validated for trace determination of residues of sulfonylurea herbicides in environmental water samples and grapes from different origins. The analytes included are triasulfuron, rimsulfuron, flazasulfuron, metsulfuron-methyl, and chlorsulfuron. Optimum separation has been achieved on a 48.5-cm x 50-microm (effective length 40 cm) bubble cell capillary using 90 mM ammonium acetate buffer, pH 4.8, by applying a voltage of 20 kV at 25 degrees C and using p-aminobenzoic acid as the internal standard. In order to increase sensitivity, large volume sample stacking with polarity switching has been applied as on-line preconcentration methodology. For water samples, a solid-phase extraction (SPE) procedure based on the use of Oasis HLB cartridges was applied for off-line preconcentration and cleanup. For grape samples, the SPE procedure was achieved with C(18) sorbent, after extraction of the compounds with MeOH:H(2)O (1:1) by sonication. The limits of detection for the studied compounds were between 0.04 and 0.12 microg/L for water samples and 0.97 and 8.30 microg/kg in the case of grape samples, lower in all cases than the maximum residue limits permitted by the EU for this kind of food. The developed methodology has demonstrated its suitability for the monitoring of these residues in environmental water and grape samples with high sensitivity, precision, and satisfactory recoveries.

Dithiothreitol-based oxidative potential for airborne particulate matter: an estimation of the associated uncertainty.

Oxidative stress is considered as one of the main mechanisms by which airborne particles produce adverse health effects. Several methods to estimate the oxidative potential (OP) of particulate matter (PM) have been proposed. Among them, the dithiothreitol (DTT) assay has gained popularity due to its simplicity and overall low implementation cost. Usually, the estimations of OPDTT are based on n-replicates of a set of samples and their associated standard deviation. However, interlaboratory comparisons of OPDTT can be difficult and lead to misinterpretations. This work presents an estimation of the total uncertainty for the OPDTT measurement of PM10 and PM2.5 samples collected in Santiago (Chile), based on recommendations by the Joint Committee for Guides in Metrology and Eurachem. The expanded uncertainty expressed as a percentage of the mass-normalized OPDTT measurements was 18.0% and 16.3% for PM10 and PM2.5 samples respectively. The dominating contributor to the total uncertainty was identified (i.e., DTT consumption rate, related to the regression and repeatability of experimental data), while the volumetric operations (i.e., pipettes) were also important. The results showed that, although the OP measured following the DTT assay has been successfully used to estimate the potential health impacts of airborne PM, uncertainty estimations must be considered before interpreting the results.

Bibliometric analysis of core journals which publish articles of physical therapy on aging.

OBJECTIVE: Increase in population's longevity has led to considerable efforts worldwide on physical therapy aging research. The aim of this study is to identify which are the main scientific journals, as well as the most productive authors, institutions and keywords related to the journals, that have published about physical therapy and aging. METHODS: Original articles published from 1990 to 2014 were retrieved from the bibliographic database Science Citation Index Expanded of Web of Science Core Collection. After standardization of the bibliographic information, a series of bibliometric indicators was obtained regarding authors, institutions, citation and keywords of the core journals using bibliometric software. The PAJEK network analysis program was used for graphic representation. RESULTS: A total of 2,237 original articles are included in this analysis. The number of identified journals is 573, with an average growth of publishing journals throughout the studied period of 9.41%. Bradford's distribution shows 12 core journals, out of which 41.67% have published constantly all throughout the 25-year period, being the most productive one Physical Therapy. Fritz, Julie M is the most productive author, and University of Sydney the most productive institution. The keyword exercise is used in an outstanding way. CONCLUSIONS: The productivity trends provided an indication of the greater scientific interest of physical therapy in aging as a line of research. Collectively, the data indicated that physical therapy-specific journals are being consolidated but non-specific are still a significant research source, and that a fundamental element of their research includes exercise and movement.