IDH1 mutation produces R-2-hydroxyglutarate (R-2HG) and induces mir-182-5p expression to regulate cell cycle and tumor formation in glioma.

BACKGROUND: Mutations in isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2), are present in most gliomas. IDH1 mutation is an important prognostic marker in glioma. However, its regulatory mechanism in glioma remains incompletely understood. RESULTS: miR-182-5p expression was increased within IDH1-mutant glioma specimens according to TCGA, CGGA, and online dataset GSE119740, as well as collected clinical samples. (R)-2-hydroxyglutarate ((R)-2HG) treatment up-regulated the expression of miR-182-5p, enhanced glioma cell proliferation, and suppressed apoptosis; miR-182-5p inhibition partially eliminated the oncogenic effects of R-2HG upon glioma cells. By direct binding to Cyclin Dependent Kinase Inhibitor 2 C (CDKN2C) 3'UTR, miR-182-5p inhibited CDKN2C expression. Regarding cellular functions, CDKN2C knockdown promoted R-2HG-treated glioma cell viability, suppressed apoptosis, and relieved cell cycle arrest. Furthermore, CDKN2C knockdown partially attenuated the effects of miR-182-5p inhibition on cell phenotypes. Moreover, CDKN2C knockdown exerted opposite effects on cell cycle check point and apoptosis markers to those of miR-182-5p inhibition; also, CDKN2C knockdown partially attenuated the functions of miR-182-5p inhibition in cell cycle check point and apoptosis markers. The engineered CS-NPs (antagomir-182-5p) effectively encapsulated and delivered antagomir-182-5p, enhancing anti-tumor efficacy in vivo, indicating the therapeutic potential of CS-NPs(antagomir-182-5p) in targeting the miR-182-5p/CDKN2C axis against R-2HG-driven oncogenesis in mice models. CONCLUSIONS: These insights highlight the potential of CS-NPs(antagomir-182-5p) to target the miR-182-5p/CDKN2C axis, offering a promising therapeutic avenue against R-2HG's oncogenic influence to glioma.

The crucial roles of ICT, renewable energy sources, industrialization, and institutional quality in achieving environmental sustainability in BRICS.

The BRICS countries-Brazil, Russia, India, China, and South Africa-are committed to achieving United Nations Sustainable Development Goal 13, which focuses on mitigating climate change. To attain this goal, it is crucial to emphasize the significance of ICT, renewable energy sources, industrialization, and institutional quality. This study contributes to the literature by examining the potential role of these factors in environmental sustainability in the BRICS economies from 2000 to 2021, utilizing cross-sectional augmented autoregressive distributed lag (CS-ARDL) estimation and other novel econometric techniques. Accordingly, the study suggests that BRICS governments and policymakers prioritize the use of ICT in the industrial and institutional sectors to achieve faster environmental sustainability in the short-run, as per the CS-ARDL results. However, the study advises caution in the long-term as the interaction between ICT and renewable energy sources, industrialization, and institutional quality may not favour environmental quality. Although the renewable energy sources interaction with ICT may not yield immediate progress, strong measures need to be taken to ensure that short-term gains are not nullified. In conclusion, the study highlights the potential of ICT, renewable energy sources, industrialization, and institutional quality in achieving environmental sustainability in the BRICS countries, while recommending cautious measures in the long run to safeguard the progress made.

Concomitant use of extracorporeal membrane oxygenation and percutaneous microaxial assist device support for cardiogenic shock.

Objectives: Venoarterial extracorporeal membrane oxygenation (VA-ECMO) with concomitant percutaneous microaxial left ventricular assist device support is an emerging treatment modality for cardiogenic shock (CS). Survival outcomes by CS etiology with this support strategy have not been well described. Methods: This study was a retrospective, single-center analysis of patients with CS due to acute myocardial infarction (AMI-CS) or decompensated heart failure (ADHF-CS) supported with VA-ECMO with concomitant percutaneous microaxial left ventricular assist device support from December 2020 to January 2023. Results: A total of 44 patients were included (AMI-CS, n = 20, and ADHF-CS, n = 24). Patients with AMI-CS and ADHF-CS had similar survival at 90 days postdischarge (P = .267) with similar destinations after support (P = .220). Patients with AMI-CS initially supported with VA-ECMO were less likely to survive 90 days postdischarge (P = .038) when compared with other cohorts. Limb ischemia and acute kidney injury occurred more frequently in patients presenting with AMI-CS (P =.013; P = .030). Subanalysis of ADHF-CS patients into acute-on-chronic decompensated HF and de novo HF demonstrated no difference in survival or destination. Conclusions: VA-ECMO with concomitant percutaneous microaxial left ventricular assist device support can be used to successfully manage patients with CS. There is no difference in survival or destination for AMI-CS and ADHF-CS with this support strategy. AMI-CS patients with initial VA-ECMO support have increased mortality in comparison to other cohorts. Future multicenter studies are required to fully analyze the differences between AMI-CS and ADHF-CS with this support strategy.

Can curcumin supplementation break the vicious cycle of inflammation, oxidative stress, and uremia in patients undergoing peritoneal dialysis?

BACKGROUND & AIMS: Turmeric (a source of curcumin) is an excellent food to modulate oxidative stress, inflammation, and gut dysbiosis in patients with chronic kidney disease (CKD). However, no studies report the benefits of curcumin in patients undergoing peritoneal dialysis (PD). This study aims to evaluate the effects of curcuminoid supplementation on oxidative stress, inflammatory markers, and uremic toxins originating from gut microbiota in patients with CKD undergoing PD. METHODS: This longitudinal, randomized, single-blind, placebo-controlled trial evaluated 48 patients who were randomized into two groups: Curcumin (three capsules of 500 mg of Curcuma longa extract, with 98.42 % total curcuminoids) or placebo (three capsules of 500 mg of starch) for twelve weeks. In the peripheral blood mononuclear cells (PBMCs), the transcriptional expression levels of Nrf2, HOX-1 and NF-κB were evaluated by quantitative real-time PCR. Oxidative stress was evaluated by malondialdehyde (MDA) and total Thiol (T-SH). TNF-α and IL-6 plasma levels were measured by ELISA. P-cresyl sulphate plasma level, a uremic toxin, was evaluated by high-performance liquid chromatography (HPLC) with fluorescent detection. RESULTS: Twenty-four patients finished the study: 10 in the curcumin group (57.5 ± 11.6 years) and 14 in the placebo group (56.5 ± 10.0 years). The plasma levels of MDA were reduced after 12 weeks in the curcumin group (p = 0.01), while the placebo group remained unchanged. However, regarding the difference between the groups at the endpoint, no change was observed in MDA. Still, there was a trend to reduce the p-CS plasma levels in the curcumin group compared to the placebo group (p = 0.07). Likewise, the concentrations of protein thiols, mRNA expression of Nrf2, HOX-1, NF-κB, and cytokines plasma levels did not show significant changes. CONCLUSION: Curcuminoid supplementation for twelve weeks attenuates lipid peroxidation and might reduce uremic toxin in patients with CKD undergoing PD. This study was registered on Clinicaltrials.gov as NCT04413266.

Redefining bladder neck dose in low-dose-rate prostate brachytherapy-Can we improve urinary toxicity without impacting disease control?

BACKGROUND: We sought to assess the impact of bladder neck dose (BND) on patient reported urinary toxicity, and feasibility of relative urethral sparing technique in prostate brachytherapy (PB). METHODS AND MATERIALS: We retrospectively identified bladder neck as a point dose on post-implant CT scans in patients treated with 131Cs PB. Urinary symptoms were assessed through EPIC questionnaires. Patient cohorts were identified based on mean BND as a percentage of prescription dose with toxicity assessment at each time point. RESULTS: In our cohort of 542 patients, BND was associated with clinically significant acute urinary symptoms and chronic symptoms, as patients receiving >70% of the prescription dose had significantly worse overall EPIC scores than patients receiving ≤70% of prescription dose. There was no difference in bDFS between patients receiving BND ≤70% (96% bDFS) and >70% (94% bDFS) at a median follow up of 57 months. CONCLUSIONS: BND has a significant impact on both acute and chronic urinary symptoms, with reduced symptoms reported with BND <70% of prescription dose. With a median follow up of 4.7 years, excellent bDFS has thus far been achieved with relative urethral and bladder neck sparing. Utilizing this constraint should improve urinary symptoms without impacting disease control.

Combining surface-enhanced Raman spectroscopy and paper spray mass spectrometry for the identification and confirmation of psychotropic substances in alcoholic beverages.

Criminal practices in which an individual becomes vulnerable and prone to sexual assault after ingesting drinks spiked with doping substances have become a social concern globally. As forensic protocols require a multi-tiered strategy for chemical evidentiary analysis, the backlog of evidence has become a significant problem in the community. Herein, a fast, sensible, and complementary dual analytical methodology was developed using a single commercial paper substrate for surface-enhanced Raman spectroscopy (SERS) and paper spray mass spectrometry (PS-MS) analysis to identify psychotropic substances added to alcoholic beverages irrefutably. To study and investigate this criminal practice, pharmaceutical formulations containing distinct psychotropic substances (zolpidem, clonazepam, diazepam, and ketamine) were added to drinks typically consumed at parties and festivals (Pilsen beer, açaí Catuaba®, gin tonic, and vodka mixed with Coca-Cola Zero®). A simple liquid-liquid extraction with a low-temperature partitioning (LLE-LTP) procedure was applied to the drinks and effectively minimized matrix effects. As a preliminary analysis, SERS spectra combined with Hierarchical Clustering Analysis (HCA) provided sufficient information to investigate the samples further. The presence of the protonated species for the psychotropic substances in the spiked drinks was readily verified in the mass spectra and confirmed by tandem mass spectrometry. Finally, the results demonstrate the potential of this methodology to be easily implemented into the routine of forensic laboratories and to be further employed at harm reduction tends at parties and festivals to detect contaminated beverages promptly and irrefutably as an efficient tool to prevent such crimes.

IDH1 mutation produces R-2-hydroxyglutarate (R-2HG) and induces mir-182-5p expression to regulate cell cycle and tumor formation in glioma

Background Mutations in isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2), are present in most gliomas. IDH1 mutation is an important prognostic marker in glioma. However, its regulatory mechanism in glioma remains incompletely understood. Results miR-182-5p expression was increased within IDH1-mutant glioma specimens according to TCGA, CGGA, and online dataset GSE119740, as well as collected clinical samples. (R)-2-hydroxyglutarate ((R)-2HG) treatment up-regulated the expression of miR-182-5p, enhanced glioma cell proliferation, and suppressed apoptosis; miR-182-5p inhibition partially eliminated the oncogenic effects of R-2HG upon glioma cells. By direct binding to Cyclin Dependent Kinase Inhibitor 2 C (CDKN2C) 3'UTR, miR-182-5p inhibited CDKN2C expression. Regarding cellular functions, CDKN2C knockdown promoted R-2HG-treated glioma cell viability, suppressed apoptosis, and relieved cell cycle arrest. Furthermore, CDKN2C knockdown partially attenuated the effects of miR-182-5p inhibition on cell phenotypes. Moreover, CDKN2C knockdown exerted opposite effects on cell cycle check point and apoptosis markers to those of miR-182-5p inhibition; also, CDKN2C knockdown partially attenuated the functions of miR-182-5p inhibition in cell cycle check point and apoptosis markers. The engineered CS-NPs (antagomir-182-5p) effectively encapsulated and delivered antagomir-182-5p, enhancing anti-tumor efficacy in vivo, indicating the therapeutic potential of CS-NPs(antagomir-182-5p) in targeting the miR-182-5p/CDKN2C axis against R-2HG-driven oncogenesis in mice models. Conclusions These insights highlight the potential of CS-NPs(antagomir-182-5p) to target the miR-182-5p/CDKN2C axis, offering a promising therapeutic avenue against R-2HG's oncogenic influence to glioma.

Invasive Phenoprofiling of Acute-Myocardial-Infarction-Related Cardiogenic Shock.

BACKGROUND: Studies had previously identified three cardiogenic shock (CS) phenotypes (cardiac-only, cardiorenal, and cardiometabolic). Therefore, we aimed to understand better the hemodynamic profiles of these phenotypes in acute myocardial infarction-CS (AMI-CS) using pulmonary artery catheter (PAC) data to better understand the AMI-CS heterogeneity. METHODS: We analyzed the PAC data of 309 patients with AMI-CS. The patients were classified by SCAI shock stage, congestion profile, and phenotype. In addition, 24 h hemodynamic PAC data were obtained. RESULTS: We identified three AMI-CS phenotypes: cardiac-only (43.7%), cardiorenal (32.0%), and cardiometabolic (24.3%). The cardiometabolic phenotype had the highest mortality rate (70.7%), followed by the cardiorenal (52.5%) and cardiac-only (33.3%) phenotypes, with significant differences (p < 0.001). Right atrial pressure (p = 0.001) and pulmonary capillary wedge pressure (p = 0.01) were higher in the cardiometabolic and cardiorenal phenotypes. Cardiac output, index, power, power index, and cardiac power index normalized by right atrial pressure and left-ventricular stroke work index were lower in the cardiorenal and cardiometabolic than in the cardiac-only phenotypes. We found a hazard ratio (HR) of 2.1 for the cardiorenal and 3.3 for cardiometabolic versus the cardiac-only phenotypes (p < 0.001). Also, multi-organ failure, acute kidney injury, and ventricular tachycardia/fibrillation had a significant HR. Multivariate analysis revealed that CS phenotypes retained significance (p < 0.001) when adjusted for the Society for Cardiovascular Angiography & Interventions score (p = 0.011) and ∆congestion (p = 0.028). These scores independently predicted mortality. CONCLUSIONS: Accurate patient prognosis and treatment strategies are crucial, and phenotyping in AMI-CS can aid in this effort. PAC profiling can provide valuable prognostic information and help design new trials involving AMI-CS.

Concomitant Use of VA-ECMO and Impella Support for Cardiogenic Shock.

Background: VA-ECMO with concomitant Impella support (ECpella) is an emerging treatment modality for cardiogenic shock (CS). Survival outcomes by CS etiology with ECpella support have not been well-described. Methods: This study was a retrospective, single-center analysis of patients with cardiogenic shock due to acute myocardial infarction (AMI-CS) or decompensated heart failure (ADHF-CS) supported with ECpella from December 2020 to January 2023. Primary outcomes included 90-day survival post-discharge and destination after support. Secondary outcomes included complications post-ECpella support. Results: A total of 44 patients were included (AMI-CS, n = 20, and ADHF-CS, n = 24). Patients with AMI-CS and ADHF-CS had similar survival 90 days post-discharge (p = .267) with similar destinations after ECpella support (p = .220). Limb ischemia and acute kidney injury occurred more frequently in patients presenting with AMI-CS (p=.013; p = .030). Patients with initial Impella support were more likely to survive ECpella support and be bridged to transplant (p=.033) and less likely to have a cerebrovascular accident (p=.016). Sub-analysis of ADHF-CS patients into acute-on-chronic decompensated heart failure and de novo heart failure demonstrated no difference in survival or destination. Conclusion: ECpella can be used to successfully manage patients with CS. There is no difference in survival or destination for AMI-CS and ADHF-CS in patients with ECpella support. Patients with initial Impella support are more likely to survive ECpella support and bridge to transplant. Future multicenter studies are required to fully analyze the differences between AMI-CS and ADHF-CS with ECpella support.

Modularization for mastery learning in CS1: a 4-year action research study.

Computer programming is a skill of increasing importance in scientific and technological fields. However, in introductory computer science (CS1) courses in higher education, approximately one in every three students fails. A common reason is that students are overwhelmed by an accelerated and inflexible pace of learning that jeopardizes success. Accordingly, in the computer science education literature it has been suggested that the pedagogical philosophy of 'mastery learning,' which supports students progressing at their own pace, can improve academic outcomes of CS1 courses. Nevertheless, few extended mastery learning implementations in CS1 have been documented in the literature, and there is a lack of guidance and best practices to foster its adoption. In this paper, we present a four-year action research study in which a modular mastery-based CS1 course was designed, evaluated and improved in successive iterations with cohorts of engineering freshmen in a Latin American research university (N = 959). In the first year of the intervention, only 19.3% of students passed the course in their first semester attempting it. In successive iterations, the instructional design, teaching and learning activities, course content, and course management were iteratively improved such that by the fourth year of offering 77.1% of students passed the course in their first semester. Over this period, course attrition was reduced from 25.0% to 3.8% of the cohort, and students' mean time spent in the course decreased from 23.2 weeks (SD = 7.38) to 14.9 (SD = 3.64). Results indicate that modularization for mastery learning is a viable approach for improving academic results in a CS1 course. Practical considerations towards successful implementation of this approach are presented and discussed.

The Importance of the 5Cs of Positive Youth Development to Depressive Symptoms: A Cross-Sectional Study with University Students from Peru and Spain.

BACKGROUND: Prior research has documented the protective role of the 5Cs of Positive Youth Development (PYD) on adjustment problems, such as depressive symptoms. Nonetheless, more research is needed, especially in non-US contexts. The main objective of the present study was to assess associations between the 5Cs and depressive symptoms in Peru and Spain, considering gender differences across contexts. METHODS: Cross-sectional data was collected from undergraduate students from Peru [n = 250] and Spain [n = 1044]. RESULTS: The results revealed significant negative associations of Competence, Confidence, Character and Connection with depressive symptoms, while Caring was positively and significantly related to depressive symptoms in both samples. Regarding gender differences, female undergraduates in both samples reported high levels of Caring, while Competence was predominant among males compared to females in both countries. Likewise, higher scores in Competence and Confidence were registered among Peruvian male undergraduates compared to Spanish students, while Caring and Character were more prevalent in Spanish female undergraduates compared to Peruvian students. CONCLUSIONS: These findings confirm the importance of targeting the 5Cs of PYD alongside the role of gender and country context in intervention programs, put together to address the mental health of students in Peru and Spain.

Recombinant Escherichia coli BL21 with LngA Variants from ETEC E9034A Promotes Adherence to HT-29 Cells.

The CS21 pilus produced by enterotoxigenic Escherichia coli (ETEC) is involved in adherence to HT-29 intestinal cells. The CS21 pilus assembles proteins encoded by 14 genes clustered into the lng operon. AIM: This study aimed to determine whether E. coli BL21 (ECBL) transformed with the lng operon lacking the lngA gene (pE9034AΔlngA) and complemented in trans with lngA variants of ETEC clinical strains, as well as point substitutions, exhibited modified adherence to HT-29 cells. METHODS: A kanamycin cassette was used to replace the lngA gene in the lng operon of the E9034A strain, and the construct was transformed into the ECBL strain. The pJET1.2 vector carrying lngA genes with allelic variants was transformed into ECBLpE9034AΔlngA (ECBLΔlngA). The point substitutions were performed in the pJETlngAFMU073332 vector. RESULTS: Bioinformatic alignment analysis of the LngA proteins showed hypervariable regions and clustered the clinical ETEC strains into three groups. Variations in amino acid residues affect the adherence percentages of recombinant ECBL strains with lngA variants and site-specific mutations with HT-29 cells. CONCLUSION: In this study, ECBL carrying the lng operon harboring lngA variants of six clinical ETEC strains, as well as point substitutions, exerted an effect on the adherence of ECBL to HT-29 cells, thereby confirming the importance of the CS21 pilus in adherence.

Prospects for fungal bioremediation of unburied waste packages from the Goiânia radiological accident.

Goiânia, the Goiás State capital, starred in 1987, where one of the largest radiological accidents in the world happened. A teletherapy machine was subtracted from a derelict radiotherapy clinic and disassembled by scavengers who distributed fragments of the 50 TBq 137CsCl source among relatives and acquaintances, enchanted by the blue shine of the substance. During the 15 days before the accident was acknowledged, contaminated recycling materials were delivered to recycling factories in four cities in the state of São Paulo, Brazil, in the form of recycling paper bales. The contaminated bales were spotted, collected, and stored in fifty 1.6 m3 steel boxes at the interim storage facility of the Nuclear and Energy Research Institute (IPEN). In 2017, a check of the content was performed in a few boxes and the presence of high moisture content was observed even though the bales were dry when conditioned and the packages were kept sealed since then. The main objective of this work was to report the fungi found in the radioactive waste after they evolved for 30 years in isolation inside the waste boxes and their role in the decay of the waste. Examination of the microbiome showed the presence of nematodes and fungal communities. The fungi species isolated were Aspergillus quadricinctus, Fusarium oxysporum, Lecanicillium coprophilumi, Scedosporium boydii, Scytalidium lignicola, Xenoacremonium recifei, and Pleurostoma richardsiae. These microorganisms showed a significant capacity to digest cellulose in our trials, which could be one of the ways they survive in such a harsh environment, reducing the volume of radioactive paper waste. These metabolic abilities give us a future perspective of using these fungi in biotechnology to remediate radioactively contaminated materials, particularly cellulose-based waste.

Predicting the final grade using a machine learning regression model: insights from fifty percent of total course grades in CS1 courses.

This article introduces a model for accurately predicting students' final grades in the CS1 course by utilizing their grades from the first half of the course. The methodology includes three phases: training, testing, and validation, employing four regression algorithms: AdaBoost, Random Forest, Support Vector Regression (SVR), and XGBoost. Notably, the SVR algorithm outperformed the others, achieving an impressive R-squared (R2) value ranging from 72% to 91%. The discussion section focuses on four crucial aspects: the selection of data features and the percentage of course grades used for training, the comparison between predicted and actual values to demonstrate reliability, and the model's performance compared to existing literature models, highlighting its effectiveness.

Positive identity predicts psychological wellbeing in Chilean youth: A double-mediation model.

Positive youth development (PYD) allows the youth to be comprehended from their potential, strengths and assets, in contrast to the traditional deficit view that focuses on their weaknesses. The PYD model promotes constructive behaviours in youth by highlighting the positive attributes usually found during the transition from childhood to adulthood to achieve healthy and optimal development in later life. Overall, PYD comprises five key competence (5C), the flourishing models and forty developmental assets. In the present study, a structural equation model is tested with the Chilean dataset of the PYD project on the premise that Positive Identity is the core internal developmental asset explaining Psychological wellbeing and that Confidence and Character are mediators of the relationship between Positive Identity and Psychological Wellbeing. The sample comprised 261 participants (n Women = 189, n Men = 72), Mean Age = 22 years old, who were approached by an online survey uploaded to Qualtrics. The measures of the study included: The Developmental assets Scale, the Short-form of the Five Cs included in the PYD and the Mental Health Continuum Short-Form. The results indicated a good model fit (ß = 1.74, Z total = 10.63, χ 2 = 424.95, df = 277, χ2/df = 1.53, p < 0.001, Robust CFI = 0.945, Robust RMSEA = 0.049, 90% CI (0.040, 0.058), AIC = 17689.91, saBIC = 17719.08 and SRMR = 0.061), highlighting the relevance of studying Latin-American adolescents and young 's wellbeing in times of COVID-19, as the participants' Positive Identity significantly predicted their Psychological Wellbeing, and simultaneously, this relationship was mediated by both their level of Confidence and Character.

Adhesin related genes as potential markers for the enteroaggregative Escherichia coli category.

Enteroaggregative Escherichia coli (EAEC) is an important cause of diarrhea in children and adults worldwide. This pathotype is phenotypically characterized by the aggregative-adherence (AA) pattern in HEp-2 cells and genetically associated to the presence of the aatA gene. EAEC pathogenesis relies in different virulence factors. At least, three types of adhesins have been specifically associated with EAEC strains: the five variants of the aggregative adherence fimbriae (AAF), the aggregative forming pilus (AFP) and more recently, a fibrilar adhesin named CS22. Our study aimed to evaluate the presence of AAF, AFP and CS22-related genes among 110 EAEC strains collected from feces of children with diarrhea. The presence of aggR (EAEC virulence regulator) and genes related to AAFs (aggA, aafA, agg3A, agg4A, agg5A and agg3/4C), AFP (afpA1 and afpR) and CS22 (cseA) was detected by PCR, and the adherence patterns were evaluated on HeLa cells. aggR-positive strains comprised 83.6% of the collection; among them, 80.4% carried at least one AAF-related gene and presented the AA pattern. aggA was the most frequent AAF-related gene (28.4% of aggR+ strains). cseA was detected among aggR+ (16.3%) and aggR- strains (22.2%); non-adherent strains or strains presenting AA pattern were observed in both groups. afpR and afpA1 were exclusively detected among aggR- strains (77.8%), most of which (71.4%) also presented AA pattern. Our results indicate that AAF- and AFP-related genes may contribute to identify EAEC strains, while the presence of cseA and its importance as an EAEC virulence factor and genotypic marker needs to be further evaluated.

Raman spectroscopy coupled to high-resolution continuum source flame molecular absorption spectrometry for sequential determination of nitrogen species in fertilizers.

Raman spectroscopy (RS) was used to identify and quantify different nitrogen species in fertilizers. This is a fast and inexpensive method that requires no extensive sample preparation. Urea and nitrate were determined at 1000 and 1045 cm-1, respectively. Calibration plots obtained for these analytes showed adequate linearity, with regression coefficients (r) of 0.9989 and 0.9976, respectively. Ammonium was determined by difference after total N determination by high-resolution continuum source flame molecular absorption spectrometry (HR-CS FMAS), which provided a calibration plot with r = 0.9960. The inline coupling of RS and HR-CS FMAS allowed for a fast sequential determination of ammonium, nitrate, and urea, with limits of detection of 0.03 mg/L ammonium, 0.03 mg/L nitrate, and 0.01 mg/L urea. Relative standard deviations were ≤ 11 %, and the external standard calibration method provided accurate results for all analytes determined in certified reference materials, raw materials, and commercial samples of fertilizers. For comparison purposes, all samples were also analyzed by traditional Kjeldahl method. The RS HR-CS FMAS method was further validated by addition and recovery experiments, which provided recoveries in the 93 - 113 % range.

Primary germinoma of the medulla oblongata: illustrative case.

BACKGROUND: Primary central nervous system germinomas of the medulla oblongata are extremely rare and usually have been found in young female Asian patients. The authors present an illustrative case of a patient who presented with severe medullary and posterior cord syndrome, the first South American case published to date, to the authors' knowledge. OBSERVATIONS: Initially, the radiological differential diagnosis did not include this entity. The lesion was located at the obex and exhibited a well-delineated contrast enhancement without hydrocephalus. An emergency decompressive partial resection following functional limits was performed. After histological confirmation, radiotherapy was indicated, with complete remission achieved at a 6-month follow-up. The patient, however, continued to have a severe proprioceptive disorder. The literature review identified 21 other such patients. The mean age for this location was 23 years, with a strong female and Asian origin predilection. All tumors exhibited contrast enhancement, and only one presented with hydrocephalus. LESSONS: In the absence of elevated tumor markers, radiological clues such as a well-delineated, contrast-enhanced lesion arising from the obex, without hydrocephalus, associated with demographic features such as young age, female sex, and Asian heritage, should evoke a high level of suspicion for this diagnosis. Gross total resection must not be attempted, because this tumor is potentially curable with high-dose radiotherapy.

A 140-year record of environmental changes in São Sebastião, Brazil.

Over the past two centuries, coastal and estuarine areas have experienced environmental stress due to rapid population growth, leading to higher demand, overexploitation, habitat transformation, and pollution, which have severe consequences on the overall ecosystem and human health. This work aims to understand historical perspectives of such environmental stress in a coastal area of São Sebastião city in the São Paulo State of Brazil, which has witnessed rapid changes in land use over the past 60-70 years. We collected eleven surface sediments and one 64 cm long core from the shallow water depth sector of the São Sebastião Channel (SSC), adjacent to the Araçá Bay region. Sediments were dominantly composed of terrestrial siliciclastic material carrying signatures of both local inputs (i.e., weathered granitic and gneissic rocks of Serra do Mar Mountain ranges) and Plata Plume sediments brought by Brazilian coastal currents. Low sediment accumulation (avg. = 0.10 cm yr-1) between 1880 and 1947 showed a stable environment followed by an abrupt increase in sedimentation (avg. = 0.84 cm yr-1) from 1947 to 2017. This approximate eight-fold increase in sedimentation after 1947 marked significant anthropogenic changes in the region, which is coincidental with major changes in land use through the construction of the port of São Sebastião (1930s) and BR-101 Highway (1980s). While recent surface sediments showed no pollution of heavy metals, anthropogenic Zn enrichment was found between 1880 and 2000. Zn enrichment was from the combined sources, e.g., agriculture activities, domestic sewage, and possibly Zn coated ship paints. Our study also indicates that planned future expansion of São Sebastião port may further increase the sedimentation rate in SSC and impact the ecosystem of Araçá Bay and SSC.

Evaluation of dried matrix spot sampling for total sulphur determination in automotive gasoline by high-resolution continuum source molecular absorption spectrometry and direct solid sample analysis.

In this work, a method for total sulphur determination in automotive gasoline using dried matrix spot sampling is proposed. The method is based on the deposition of the sample on a cellulose-based filter paper and subsequent sulphur quantification via CS diatomic molecule using high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS GF MAS). The sample deposition was carried out, along with the chemical modifier, on a 20-mm filter paper disc previously adapted into a polytetrafluoroethylene (PTFE) mould. The liquid phase was removed by heating the PTFE mould, and then the gasoline sample-embedded filter paper was punched in smaller discs (procedure A) or pulverised (procedure B) before the analyses. The mixture of Pd and Mg was used as chemical modifier to stabilise the sulphur compounds on the filter paper and on the graphite furnace. All the calibration curves constructed using seven different sulphur-containing compounds had a coefficient of determination higher than 0.995 and a linear range from 2 to 150 mg kg-1 S. By using the optimised conditions, the best characteristic mass, limits of detection and quantitation were 6 ng, 0.6 and 1.8 mg kg-1, respectively. The two sampling procedures (A and B) were evaluated for real samples, and procedure B was chosen since it markedly improved the precision. Using this procedure, satisfactory recovery values from 95 to 106% were obtained in the spike-recovery tests. In addition, the S concentrations for the certified reference materials were not statistically different from the certified values at 95% confidence level. Sulphur concentrations from 20 to 46 mg kg-1 were found in the six analysed gasoline samples, and these values were statistically assessed using a reference method (ASTM 5453). Spectral interference caused by MgF and MgCl diatomic molecules was observed and investigated.