Outcomes of transcatheter pulmonary SAPIEN 3 valve implantation: an international registry.

BACKGROUND AND AIMS: Transcatheter pulmonary valve implantation (TPVI) is indicated to treat right-ventricular outflow tract (RVOT) dysfunction related to congenital heart disease (CHD). Outcomes of TPVI with the SAPIEN 3 valve that are insufficiently documented were investigated in the EUROPULMS3 registry of SAPIEN 3-TPVI. METHODS: Patient-related, procedural, and follow-up outcome data were retrospectively assessed in this observational cohort from 35 centres in 15 countries. RESULTS: Data for 840 consecutive patients treated in 2014-2021 at a median age of 29.2 (19.0-41.6) years were obtained. The most common diagnosis was conotruncal defect (70.5%), with a native or patched RVOT in 50.7% of all patients. Valve sizes were 20, 23, 26, and 29 mm in 0.4%, 25.5%, 32.1%, and 42.0% of patients, respectively. Valve implantation was successful in 98.5% [95% confidence interval (CI), 97.4%-99.2%] of patients. Median follow-up was 20.3 (7.1-38.4) months. Eight patients experienced infective endocarditis; 11 required pulmonary valve replacement, with a lower incidence for larger valves (P = .009), and four experienced pulmonary valve thrombosis, including one who died and three who recovered with anticoagulation. Cumulative incidences (95%CI) 1, 3, and 6 years after TPVI were as follows: infective endocarditis, 0.5% (0.0%-1.0%), 0.9% (0.2%-1.6%), and 3.8% (0.0%-8.4%); pulmonary valve replacement, 0.4% (0.0%-0.8%), 1.3% (0.2%-2.4%), and 8.0% (1.2%-14.8%); and pulmonary valve thrombosis, 0.4% (0.0%-0.9%), 0.7% (0.0%-1.3%), and 0.7% (0.0%-1.3%), respectively. CONCLUSIONS: Outcomes of SAPIEN 3 TPVI were favourable in patients with CHD, half of whom had native or patched RVOTs.

Feasibility of Identifying Household Contacts of Rifampin-and Multidrug-resistant Tuberculosis Cases at High Risk of Progression to Tuberculosis Disease.

BACKGROUND: We assessed multidrug-resistant tuberculosis (MDR-TB) cases and their household contacts (HHCs) to inform the development of an interventional clinical trial. METHODS: We conducted a cross-sectional study of adult MDR-TB cases and their HHCs in 8 countries with high TB burdens. HHCs underwent symptom screenings, chest radiographies, sputum TB bacteriologies, TB infection (TBI) testing (tuberculin skin test [TST] and interferon gamma release assay [IGRA]), and human immunodeficiency virus (HIV) testing. RESULTS: From October 2015 to April 2016, 1016 HHCs from 284 MDR-TB cases were enrolled. At diagnosis, 69% of MDR-TB cases were positive for acid-fast bacilli sputum smears and 43% had cavitary disease; at study entry, 35% remained smear positive after a median MDR-TB treatment duration of 8.8 weeks. There were 9 HHCs that were diagnosed with TB prior to entry and excluded. Of the remaining 1007 HHCs, 41% were male and the median age was 25 years. There were 121 (12%) HHCs that had new cases of TB identified: 17 (2%) were confirmed, 33 (3%) probable, and 71 (7%) possible TB cases. The TBI prevalence (defined as either TST or IGRA positivity) was 72% and varied by age, test used, and country. Of 1007 HHCs, 775 (77%) were considered high-risk per these mutually exclusive groups: 102 (10%) were aged <5 years; 63 (6%) were aged ≥5 and were infected with HIV; and 610 (61%) were aged ≥5 years, were negative for HIV or had an unknown HIV status, and were TBI positive. Only 21 (2%) HHCs were on preventive therapy. CONCLUSIONS: The majority of HHCs in these high-burden countries were at high risk of TB disease and infection, yet few were receiving routine preventive therapy. Trials of novel, preventive therapies are urgently needed to inform treatment policy and practice.

Environmental Levels, Sources, and Cancer Risk Assessment of PAHs Associated with PM2.5 and TSP in Monterrey Metropolitan Area.

In this work, the content of polycyclic aromatic hydrocarbons (PAHs) in total suspended particles and particulate matter with an aerodynamic diameter ≤ 2.5 µm (PM2.5) was analyzed using gas chromatography-mass spectrometry. In addition, a sequential chemical analysis of C-rich particles was performed through the parallel coupling of micro-Raman spectroscopy and scanning electron microscopy with X-ray scattering detection. Samples were collected at four sites in the Monterrey metropolitan area, Mexico. A total of 13 PAHs were quantified; indeno(1,2,3-cd)pyrene, chrysene, and benzo(a)anthracene were the most abundant. The total PAH concentrations at the four sampling sites ranged from 1.34 to 8.76 µg/m3. The diagnostic relation of the PAHs indicates that these compounds were emitted by the burning of gasoline and diesel and by the burning of charcoal and biomass. The sequential analysis correlated the morphology and the elemental/molecular composition of the C-rich particles, associated with the PAHs, with their possible emission sources. The estimated lifetime excess cancer risk for inhalation was higher than that established by the World Health Organization, which clearly makes this a potential health risk for the population.

Monitoring Anti-Pythium insidiosum IgG Antibodies and (1→3)-ß-d-Glucan in Vascular Pythiosis.

Despite aggressive treatment, vascular pythiosis has a mortality rate of 40%. This is due to delays in diagnosis and a lack of effective monitoring tools. To overcome this drawback, serum beta-d-glucan (BG) and P. insidiosum-specific antibody (Pi-Ab) were examined as potential monitoring markers in vascular pythiosis. A prospective cohort study of vascular pythiosis patients was carried out from January 2010 to July 2016. Clinical information and blood samples were collected and evaluated by the BG and Pi-Ab assays. Linear mixed-effect models were used to compare BG and Pi-Ab levels. The in vitro susceptibility test was performed with all P. insidiosum isolates from culture-positive cases. A total of 50 patients were enrolled: 45 survived and 5 died during follow-up. The survivors had a significantly shorter time to medical care (P < 0.0001) and a significantly shorter waiting time to the first surgery (P < 0.0001). There were no differences in BG levels among the groups at diagnosis (P = 0.33); however, BG levels among survivors were significantly lower than those of the deceased group at 0.5 months (P < 0.0001) and became undetectable after 3 months. Survivors were able to maintain an enzyme-linked immunosorbent assay (ELISA) value (EV) of Pi-Ab above 8, whereas the EV among deceased patients was less than 4. In vitro susceptibility results revealed no synergistic effects between itraconazole and terbinafine. This study showed that BG and Pi-Ab are potentially valuable markers to monitor the disease after treatment initiation. An unchanged BG level at 2 weeks after surgery should prompt an evaluation for residual disease.

Fetal Aortic Valvuloplasty: Experience and Results of Two Tertiary Centers in Spain.

OBJECTIVE: Fetal aortic valvuloplasty (FAV) may avoid progression of critical aortic stenosis (CAS) to hypoplastic left ventricle, improving the options for biventricular circulation (BVC). We describe the results of FAV in 2 referral centers in Spain. METHODS: We analyzed all FAVs performed in the period 2007-2015. The selection of candidates, the technique, and postnatal management were made following an agreed protocol. A descriptive analysis of survival, type of circulation after birth, and complications was made, considering all deaths in the first 48 h after FAV as FAV-related. RESULTS: FAV was performed in 28 fetuses at a median gestational age (GA) of 23 weeks (range, 20-32). FAV was technically successful in 22 (78.6%), of whom 11 were born alive and with intention to treat. Eight (72.7%) resulted in BVC and 3 (27.3%) in univentricular circulation. The rate of FAV-related deaths was 32%. These patients underwent FAV earlier than live-born fetuses (median GA at FAV 22 weeks [range, 20.0-25.0] vs. 24.5 weeks [range, 21.0-32.0], respectively, p = 0.031). CONCLUSIONS: A significant proportion of fetuses with CAS who undergo technically successful FAV have BVC postnatally. However, FAV implies a high risk of fetal death, which highly depends on the GA at which this intervention is required.

Culture and drug sensitivity testing among patients with pulmonary tuberculosis in Mexico: national data for 2009-2013.

This study documented the number and results of mycobacterial culture and drug sensitivity testing (CDST) in Mexico from 2009-2013 and assessed whether states with a higher risk of multidrug-resistant tuberculosis (MDR-TB) performed more CDST and had more cultures showing MDR-TB. Data for this longitudinal, descriptive, operational research study came from the electronic records of 31 state public health laboratories in Mexico. The total number of CDSTs was 6 470, increasing from 2 143 in the first 2 years to 4 327 in the latter 3 years. There was a significant increase in the proportion of cultures showing sensitivity to all drugs, from 53.1% to 60.9% in 2011-2013 (P < 0.001) and a significant decrease in the proportion showing MDR-TB, from 28.2% in 2009 to 19.8% in 2013 (P < 0.001). Cases of extensively drug resistant tuberculosis were < 1% per year. In the 12 states with higher risk for MDR-TB, significantly more CDSTs (2 382 test) were done in 2011-2013 than in the other 19 states (1 945 tests). Also, for each year the proportion of cultures showing MDR-TB was significantly higher in high risk MDR-TB states than in lower risk ones (P < 0.001). During the 5-year study period, CDST was scaled up in Mexico, particularly in high-risk MDR-TB states where a higher proportion of cultures showed MDR-TB. Scale up and wider coverage of CDST should continue.

Use and evaluation of a line probe assay in patients with tuberculosis in Peru: 2011-2013.

Objective To determine the use and performance of a line probe assay (LPA) compared with conventional culture and drug sensitivity testing (CDST) in patients registered with tuberculosis (TB) under routine program conditions in Peru in 2011-2013. Methods This was a descriptive, operational research, cross-sectional study of sputum specimens from patients with smear-positive pulmonary TB and mycobacterial cultures from patients with smear-negative or positive TB. Drug resistance to rifampicin and/or isoniazid detected by LPA was compared to CDST. Sensitivity, specificity, and predictive values were calculated and reliability for detecting drug resistance was assessed through kappa coefficient, with values 0.61-0.80 showing substantial correlation, and 0.81 or above showing almost-perfect correlation. Results In 2011-2013, there were 16 169 LPA tests performed, with the proportion of TB patients receiving the test increasing from 3.2% to 30.2%. In all, 2 905 LPA test results were compared to CDST. For LPA in sputum specimens, sensitivity for rifampicin was 92%; isoniazid, 94%; and MDR-TB, 88%; while specificity for rifampicin was 92%; isoniazid, 92%; and MDR-TB, 95%. For LPA in mycobacterial cultures, sensitivity for rifampicin was 95%; isoniazid, 96%; and MDR-TB, 90%; while specificity for rifampicin was 85%; isoniazid, 91%; and MDR-TB, 94%. Kappa coefficients were at 0.81 or above for all comparisons of LPA with CDST using sputum specimens and cultures, except for isoniazid in cultures, which was at 0.79. Conclusions This study suggests that LPA is a reliable and rapid screening test for drug-resistant TB and should be considered suitable for routine use and scale up in Peru.

Transposition of the Great Arteries in Fetal Life: Accuracy of Diagnosis and Short-Term Outcome.

OBJECTIVE: To review our series of prenatally diagnosed transposition of the great arteries (TGA) to analyze the accuracy of fetal echocardiography for achieving a precise diagnosis of the TGA type (simple vs. complex) and to examine the short-term outcome. METHODS: A total of 94 cases of simple and complex TGA types (ventriculoarterial discordance with atrioventricular concordance) prenatally evaluated in our referral center between 1998 and 2014 were included. Fetuses with additional congenital anomalies and those with incomplete follow-up were excluded. Prenatal diagnostic accuracy and short-term survival were analyzed for the different types of TGA. RESULTS: The TGA type was correctly ascertained prenatally in 93.3%. Most fetuses were diagnosed with simple TGA (62.7%). There were 6 discrepancies: 5 fetuses with simple TGA had postnatally TGA + ventricular septal defect (VSD; n = 3) or TGA + VSD + coarctation of the aorta (n = 2), and 1 fetus with TGA + VSD postnatally showed severe left ventricular outflow tract obstruction. The mortality rate was 6.6%; it was higher in complex versus simple forms (12.8 vs. 1.9%, p = 0.038), and in cases with intramural coronary artery versus those without (60 vs. 3.5%, p < 0.001). We found no relationship between the arrangement of the great arteries and coronary arterial abnormalities. CONCLUSIONS: Simple TGA has a better outcome than the complex forms. A discrepancy rate of 7% with potential influence on the prognosis of survival between the prenatal diagnosis of the TGA type and the definitive diagnosis was found.

Pulmonary vasodilator therapy and early postoperative outcome after modified Fontan operation.

Although mortality is low after the modified Fontan procedure, there is a significant percentage of patients with prolonged postoperative recovery. The objective of this study is to evaluate the usefulness of postoperative administration of oral sildenafil and inhaled nitric oxide on early postoperative outcome. A prospective interventional and comparison study with a historical cohort was conducted. Between January, 2010 and March, 2013, 16 patients received oral sildenafil during immediate modified Fontan postoperative period. Inhaled nitric oxide was also administered if the patient was kept intubated 12 hours after surgery. Early postoperative outcome was compared with a historical cohort of 32 patients on whom the modified Fontan procedure was performed between March, 2000 and December, 2009. Postoperative administration of sildenafil and nitric oxide had no influence on early postoperative outcome after the modified Fontan procedure in terms of duration of pleural effusions, mechanical ventilation time, length of stay in the ICU, and length of hospital stay.

Accumulation of fatty acids in Chlorella vulgaris under heterotrophic conditions in relation to activity of acetyl-CoAcarboxylase, temperature, and co-immobilization with Azospirillum brasilense [corrected].

The relation between fatty acid accumulation, activity of acetyl-CoA carboxylase (ACC), and consequently lipid accumulation was studied in the microalgae Chlorella vulgaris co-immobilized with the plant growth-promoting bacterium Azospirillum brasilense under dark heterotrophic conditions with Na acetate as a carbon source. In C. vulgaris immobilized alone, cultivation experiments for 6 days showed that ACC activity is directly related to fatty acid accumulation, especially in the last 3 days. In co-immobilization experiments, A. brasilense exerted a significant positive effect over ACC activity, increased the quantity in all nine main fatty acids, increased total lipid accumulation in C. vulgaris, and mitigated negative effects of nonoptimal temperature for growth. No correlation between ACC activity and lipid accumulation in the cells was established for three different temperatures. This study demonstrated that the interaction between A. brasilense and C. vulgaris has a significant effect on fatty acid and lipid accumulation in the microalgae.

Gestational age-specific scoring systems for the prediction of coarctation of the aorta.

OBJECTIVES: To determine which combination of cardiac parameters provides the best prenatal prediction of coarctation of aorta (CoAo). METHODS: We selected all cases of simple cardiac asymmetry prenatally diagnosed in 2003-2013. Logistic regression was used to select the best predictors of CoAo. RESULTS: The study population included 115 fetuses. CoAo was confirmed in 52 neonates (45%). The sample was divided in two groups according to the gestational age (GA) at diagnosis: early group (EG) ≤28 weeks (n = 57), and late group (LG) >28 weeks (n = 58). CoAo was confirmed in 75% and 16% of cases, respectively. GA-specific scoring systems with maximum two parameters were made, and the pairwise combination with the best diagnostic performance for each group was selected. In EG, the z-score of ascending aorta (AAo) and aortic isthmus (three vessels and trachea view) showed the best diagnostic accuracy [area under receiver-operating curve (AUC) 0.98, 95% confidence interval (CI) 0.94-1.00]. In the LG, the best results were provided by the tricuspid valve/mitral valve ratio with the main pulmonary artery/AAo ratio (AUC 0.84, 95% CI 0.67-1.00). CONCLUSIONS: Gestational age-specific scoring systems combining size-based cardiac parameters may improve the accuracy of fetal echocardiography to stratify the risk of CoAo. The objectivity and simplicity of its components may facilitate its implementation in fetal cardiology units.

Prenatal prediction of surgical approach for coarctation of the aorta repair.

OBJECTIVE: To evaluate the capacity of fetal echocardiography for predicting the more likely surgical approach in newborns with coarctation of the aorta (CoAo) (left thoracotomy vs. median sternotomy). MATERIAL AND METHODS: We selected all cases of suspected CoAo prenatally diagnosed in 2003-2012 (n = 95). 49/95 were considered at high-risk and 46/95 at low-risk of CoAo, and 38/49 and 7/46 were postnatally confirmed, respectively. We firstly evaluated in 40 cases of CoAo surgically repaired (24 thoracotomy, 16 sternotomy) whether there were differences in fetal echocardiographic parameters between both groups. Secondly, we assessed the performance of these parameters for predicting the surgical approach in fetuses at high risk of CoAo. RESULTS: Sternotomy approach was associated with higher rate of postoperative complications and longer hospital stay compared with thoracotomy (81.3 vs. 41.7%, p = 0.014; 30.5 vs. 15.4 days, p = 0.0004, respectively). The Z-score of the aortic isthmus, measured in the sagittal plane, was significantly smaller in the sternotomy group. In fetuses at high-risk of having CoAo a cut-off value of the isthmus Z-score ≤ -2.5 had sensitivity of 78% and specificity of 82% for predicting sternotomy approach, with 9% false positive cases in which CoAo was not confirmed. DISCUSSION: The surgical approach for CoAo repair may be prenatally predicted by means of the Z-score of aortic isthmus, measured in the sagittal plane.

Triple vasodilator therapy in pulmonary arterial hypertension associated with congenital heart disease.

OBJECTIVE: This study assessed the long-term effects of triple therapy with prostanoids on patients with pulmonary arterial hypertension associated with congenital heart disease (PAH-CHD), as there is limited information on the safety and efficacy of this treatment approach. METHODS: A retrospective cohort study was conducted on patients with PAH-CHD who were actively followed up at our centre. All patients were already receiving dual combination therapy at maximum doses. Clinical characteristics, including functional class (FC), 6-minute walking test distance (6MWTD) and N-terminal pro-brain natriuretic peptide (NT-proBNP) levels, were documented before initiating triple therapy and annually for a 2-year follow-up period. RESULTS: A total of 60 patients were included in the study, with a median age of 41 years and 68% being women. Of these, 32 had Eisenmenger syndrome, 9 had coincidental shunts, 18 had postoperative PAH and 1 had a significant left-to-right shunt. After 1 year of triple combination initiation, a significant improvement in 6MWTD was observed (406 vs 450; p=0.0027), which was maintained at the 2-year follow-up. FC improved in 79% of patients at 1 year and remained stable in 76% at 2 years. NT-proBNP levels decreased significantly by 2 years, with an average reduction of 199 ng/L. Side effects were experienced by 33.3% of patients but were mostly mild and manageable. Subgroup analysis showed greater benefits in patients without Eisenmenger syndrome and those with pre-tricuspid defects. CONCLUSIONS: Triple therapy with prostanoids is safe and effective for patients with PAH-CHD, improving FC, 6MWTD and NT-proBNP levels over 2 years. The treatment is particularly beneficial for patients with pre-tricuspid defects and non-Eisenmenger PAH-CHD.

Second-line anti-tuberculosis drug concentrations for susceptibility testing in the MODS assay.

Multidrug-resistant tuberculosis (TB) threatens TB control worldwide. The microscopic observation drug susceptibility (MODS) assay is a low-cost, high-performance TB diagnostic tool for rapid liquid culture and direct isoniazid and rifampicin drug susceptibility testing (DST). The objective of this study was to explore the potential for extending the MODS assay to rapid second-line DST and to identify critical concentrations of candidate drugs for prospective testing. Sputum samples from 94 TB culture-positive patients receiving second-line TB agents were cultured following standardised MODS protocols, with a range of titrations of antimicrobial drugs added. Critical concentrations were determined using a modified Kaplan-Meier survival curve analysis. Candidate critical concentrations were determined for capreomycin (10 µg·mL(-1)), ciprofloxacin (1.25 µg·mL(-1)), cycloserine (40 µg·mL(-1)), ethambutol (10 µg·mL(-1)), ethionamide (5 µg·mL(-1)), kanamycin (5 µg·mL(-1)), para-aminosalicylic acid (10 µg·mL(-1)) and streptomycin (10 µg·mL(-1)). No cut-off point was identified for the other second-line drugs or for pyrazinamide. At particular concentrations of some second-line TB drugs this novel Kaplan-Meier analysis clearly differentiated populations that were susceptible or resistant. These candidate critical concentrations should now be tested in a range of epidemiological settings to define the performance of direct, second-line TB DST with MODS, offering potential low-cost second-line TB DST capacity.

Genetic diversity and structure in two epiphytic orchids from the montane forests of southern Ecuador: The role of overcollection on Masdevallia rosea in comparison with the widespread Pleurothallis lilijae.

Ecuador has a high diversity of orchids, but little is known about levels of genetic diversity for the great majority of species. Understanding how orchids might adapt to changes is crucial as deforestation and fragmentation of forest ecosystems threaten the survival of many epiphytic orchids that depend on other species, such as fungi and their host trees, for germination, growth, and establishment. Overcollection and the illegal trade are also major concerns for the survival of wild populations of orchids. Despite increasing awareness, effective interventions are often limited by a lack of data concerning the impacts that overexploitation might have. To fill this gap, we tested the effects of overcollection in the genetic diversity and structure of Masdevallia rosea, a narrow distributed epiphytic orchid historically collected in Ecuador, in comparison with the widely distributed Pleurothallis lilijae. Genotyping based on AFLPs showed reduced levels of diversity in wild populations but most especially in the overcollected, M. rosea. Overall, genetic admixture was high in P. lilijae segregating populations by altitude levels while fewer genetic groups were found in M. rosea. Genetic differentiation was low in both species. A spatial genetic structure was found in P. lilijae depending on altitude levels, while no spatial genetic structure was found in M. rosea. These results suggest different scenarios for the two species: while gene flow over long distance is possible in P. lilijae, the same seems to be unlikely in M. rosea possibly due to the low levels of individuals in the known populations. In situ and ex situ conservation strategies should be applied to protect the genetic pool in these epiphytic orchid species, and to promote the connectivity between wild populations. Adopting measures to reduce overexploitation and to understand the impacts of harvesting in wild populations are necessary to strengthen the legal trade of orchids.

Prenatal diagnosis of isolated coronary artery fistula: systematic review, analysis of perinatal prognostic factors and case report.

BACKGROUND: Isolated coronary artery fistula (CAF) is a rare entity in which evidence for both prognosis and need for perinatal treatment is lacking. We aim to evaluate the characteristics, evolution and perinatal outcomes of reported cases, including one from our center. MATERIAL AND METHODS: We performed a systematic review in Medline, Pubmed, and Embase databases for cohort studies or case series related to prenatally diagnosed isolated congenital CAF according to PRISMA guidelines. The search was restricted to articles published until January 2022, including a case report from our center. A descriptive analysis was performed, and perinatal characteristics were dichotomized by outcome (development of symptoms, as well as the need for surgery during the neonatal period). Strength of association between prenatal variables and outcome was evaluated through Odds Ratio. RESULTS: Only 27 cases of prenatal diagnosis of isolated CAF have been published, including our patient. Most had their origin in the right coronary artery (63%) and drained in the right ventricle (55.6%). Most cases (72%) developed progressive intrauterine dilation of the fistulous tract, which was usually associated with symptoms of cardiac overload, such as cardiomegaly (57.7%). Up to two-thirds of prenatally diagnosed patients developed heart failure symptoms in the neonatal period, and 84% required postnatal intervention. Prenatal diagnosis of both cardiomegaly and diastolic steal is associated with an OR of 52 and 41 of developing postnatal symptoms. CONCLUSION: Prenatal diagnosis of isolated CAF can be achieved with adequate tools and trained sonographers. The development of cardiomegaly and diastolic steal significantly increases the risk of developing postnatal symptoms.

Rice Labeling according to Grain Quality Features Using Laser-Induced Breakdown Spectroscopy.

Rice is an important source of nutrition and energy consumed around the world. Thus, quality inspection is crucial for protecting consumers and increasing the rice's value in the productive chain. Currently, methods for rice labeling depending on grain quality features are based on image and/or visual inspection. These methods have shown subjectivity and inefficiency for large-scale analyses. Laser-induced breakdown spectroscopy (LIBS) is an analytical technique showing attractive features due to how quick the analysis can be carried out and its capability of providing spectra that are true fingerprints of the sample's elemental composition. In this work, LIBS performance was evaluated for labeling rice according to grain quality features. The LIBS spectra of samples with their grain quality numerically described as Type 1, 2, and 3 were measured. Several spectral processing methods were evaluated when modeling a k-nearest neighbors (k-NN) classifier. Variable selection was also carried out by principal component analysis (PCA), and then the optimal k-value was selected. The best result was obtained by applying spectrum smoothing followed by normalization by using the first fifteen principal components (PCs) as input variables and k = 9. Under these conditions, the method showed excellent performance, achieving sample classification with 94% overall prediction accuracy. The sensitivities ranged from 90 to 100%, and specificities were in the range of 92-100%. The proposed method has remarkable characteristics, e.g., analytical speed and analysis guided by chemical responses; therefore, the method is not susceptible to subjectivity errors.

Measuring trace element fingerprinting for cereal bar authentication based on type and principal ingredient.

This paper introduces a method for determining the authenticity of commercial cereal bars based on trace element fingerprints. In this regard, 120 cereal bars were prepared using microwave-assisted acid digestion and the concentrations of Al, Ba, Bi, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, Pb, Rb, Se, Sn, Sr, V, and Zn were later measured by ICP-MS. Results confirmed the suitability of the analyzed samples for human consumption. Multielemental data underwent autoscaling preprocessing for then applying PCA, CART, and LDA to input data set. LDA model accomplished the highest classification modeling performance with a success rate of 92%, making it the suitable model for reliable cereal bar prediction. The proposed method demonstrates the potential of trace element fingerprints in distinguishing cereal bar samples according to their type (conventional and gluten-free) and principal ingredient (fruit, yogurt, chocolate), thereby contributing to global efforts for food authentication.

Geographical origin identification of mandarin fruits by analyzing fingerprint signatures based on multielemental composition.

Given rising traders and consumers concerns, the global food industry is increasingly demanding authentic and traceable products. Consequently, there is a heightened focus on verifying geographical authenticity as food quality assurance. In this work, we assessed pattern recognition approaches based on elemental predictors to discern the provenance of mandarin juices from three distinct citrus-producing zones located in the Northeast region of Argentina. A total of 202 samples originating from two cultivars were prepared through microwave-assisted acid digestion and analyzed by microwave plasma atomic emission spectroscopy (MP-AES). Later, we applied linear discriminant analysis (LDA), k-nearest neighbor (k-NN), support vector machine (SVM), and random forest (RF) to the element data obtained. SVM accomplished the best classification performance with a 95.1% success rate, for which it was selected for citrus samples authentication. The proposed method highlights the capability of mineral profiles in accurately identifying the genuine origin of mandarin juices. By implementing this model in the food supply chain, it can prevent mislabeling fraud, thereby contributing to consumer protection.

A tunnel study to estimate emission factors from mobile sources in Monterrey, Mexico.

UNLABELLED: A six-day tunnel field study was conducted in the city of Monterrey, Mexico, during June 2009 to derive on-road emission factors (EFs)for trace gases and fine particulate matter from the local vehicle fleet. The Loma Larga Tunnel (LLT) is a 532-m-long structure that is mainly used by light-duty gasoline-powered vehicles. It is composed of two independent bores that have a semicircular cross section, 17 m in diameter with a 3.5% slope. During the study, a fleet of 108,569 vehicles with average speeds that ranged from 43 to 76 km/hr was sampled. Ambient air samples were taken inside each bore using 6-L SUMMA-polished canisters and low-volume samplers for the quantification of total nonmethane hydrocarbons (TNMHC) and PM2.5, respectively. The effect of road dust resuspension was considered in the computation of PM2.5 EFs. Additional equipment was used to measure real-time levels of CO2 and NO(x); CO EFs were estimated using NO(x) as a surrogate. TNMHC samples and NO(x) levels were obtained for 2-hr time periods, while PM2.5 samples and CO2 levels were obtained using 2.5-hr time periods, which included the time periods of the TNMHC and NO(x) measurements. Estimated EFs for TNMHC, CO, NO(x), and PM2.5 were 1.16 +/- 0.05, 4.83 +/- 2.9, and 0.11 +/- 0.07 g/km-veh (2-hr average) and 17.5 +/- 5.7 mg/veh-km (2.5-hr average), respectively, while CO2 EFs were 182.7 +/- 44 g/km-veh for the 2-hr time periods and 170 +/- 22 g/veh-km for the 2.5-hr time periods. The average fuel economy estimated from the field data was 12.3 +/- 2.3 km/L. The CO2 and TNMHC EFs (on a mass per distance basis) tended to be higher for traffic moving upslope, while the inverse occurred for the PM2.5 EFs. In comparison to other tunnel studies, the CO2 EFs obtained were similar the NO(x) and PM2.5 EFs were lower, and the CO and TNMHC EFs were higher. IMPLICATIONS: Mobile source emission factors (EFs) for Mexican cities other than Mexico City are scarce. In Monterrey, Mexico, one of the three major cities in the country, emissions inventories are constructed based on EFs from other locations. However, it is quite relevant to obtain local information to construct reliable inventories. We present what is, to our knowledge, the first tunnel study conducted in a Mexican city other than Mexico City to estimate fleet-average mobile source EFs. This is also the first study that reports PM2.5 EFs derived from a tunnel study in the country.