A review from 1996 to 2021 of tuning methodologies and controller structures applied for an unstable/stable (bio)reactor with imperfect mixing and bypass.

This paper presents a critical review of tuning methodologies and controller structures applied to the Cholette bioreactor. This (bio)reactor has been studied extensively by the automatic control community from the point of view of controller structures and tuning methodologies, from controllers with a single structure to nonlinear controllers, and from the synthesis method to the frequency response. Therefore, new trends and opportunities of study have been detected with regard to their operating points, controller structures and tuning methodologies which could be addressed for this system.

Increased frequency of CD14+HLA-DR-/low cells in type 2 diabetes patients with poor glycemic control.

AIMS: Type 2 diabetes (T2DM) is associated with alterations of the immune response and T2DM patients have an increased risk for infections and certain sorts of cancers. Although CD14+HLA-DR-/low cells have emerged as important mediators of immunosuppression in several pathologies, including cancer and non-malignant diseases, the presence of these cells in T2DM is not fully characterized. METHODS: In this study, we evaluated the frequency of CD14+HLA-DR-/low cells in non-obese T2DM patients and their association with glycemic control. Peripheral blood mononuclear cells were isolated from healthy controls (HC, n = 24) and non-obese T2DM patients (n = 25), the population was evaluated by flow cytometry, and an analysis of correlation between cell frequencies and clinical variables was performed. RESULTS: CD14+HLA-DR-/low monocytes were expanded in patients with T2DM compared to HC regardless of weight. Among the subjects with T2DM, the frequency of CD14+HLA-DR-/low was higher in patients with poor glycemic control (HbA1c > 9%) compared to those with better glycemic control (HbA1c < 9%) and, positively correlated with the years since the diagnosis of T2DM, the age of the patients and the glycemic index. CONCLUSIONS: An increased frequency of CD14+HLA-DR-/low cells in the blood of T2DM patients was recorded. The influence of hyperglycemia seems to be independent of obesity, but related to glycemic control and age.

Type 2 diabetes mellitus metabolic control correlates with the phenotype of human monocytes and monocyte-derived macrophages.

AIMS: Monocytes and macrophages express cell-surface markers indicative of their inflammatory and activation status. In this study, we investigated whether these markers are affected or correlated in non-obese T2D subjects, or glycemic/metabolic control variables. METHODS: Clinical data was recorded, and peripheral blood drawn from T2D patients (n = 28) and control subjects (n = 27). Isolated monocytes were evaluated by flow cytometry for the expression of CD14, CD16, and the phenotypic markers for the different states of activation spectrum, such as pro-inflammatory (M1) (HLA-DR, CD86), anti-inflammatory/pro-resolving (M2) (CD163, CD206, MERTK, PD-L1) and metabolically-activated (MMe) (CD36, ABCA-1). From a subset of individuals, monocytes-derived macrophages (MDM) were obtained and evaluated for phenotypic markers. A correlation analysis was performed between the clinical variables and the marker expression. RESULTS: The frequency of CD14++CD16- monocytes was lower in T2D patients and it correlates negatively with poor control in glycemic and metabolic variables. T2D monocytes expressed lower levels of HLA-DR, CD86, PD-L1, and CD163, which correlated negatively with poor metabolic control. In MDM from T2D patients, HLA-DR, CD86 and CD163 expression was lower and it inversely correlated with deficient glycemic or metabolic control parameters. CONCLUSION: The glycemic/metabolic control associated with T2D influences monocyte and MDM phenotypes toward an immune-suppressive phenotype.

Analysis of open-loop and L2∕D controlled closed-loop behavior of the Cholette's bioreactor under different operating conditions.

The scope of this paper is the analysis of open-loop and L2/D controlled closed-loop behavior of the Cholette's bioreactor under different operating conditions. The open-loop behavior is studied by means of the steady-state multiplicity areas formed by substrate feed concentration and substrate concentration in the output using the nonlinear model of the bioreactor. The stability of each steady-state inside areas is determined by a polynomial representation. The nonlinear dynamic and steady-state multiplicity areas of the Cholette's bioreactor are shown to depend on the operating conditions and concentration required. The closed-loop behavior is studied by the tuning of a set of Pareto-optimal L2/D linear controllers at a stable operating point. Numerical simulations and phase portraits are used to evaluate the control system. This paper could be a guide for theoretical and practical applications in the fields of biotechnology and automatic control.

Effect of repeated frying on the physical characteristics, the formation of acrylamide and oil uptake of tortilla chips subjected to pre-drying treatment.

Even though snacks such as tortilla chips are gaining popularity, the high intake of these products may cause problems related to their fat and acrylamide content. In consequence, this study is aimed at evaluating the effect of pre-fry drying on the absorption of oil, physicochemical characteristics and formation of acrylamide in corn tortilla chips fried in ten batches. Pre-drying was carried out at 40 °C, 50 °C and 60 °C and two air velocities (1.0 m/s2 year 1.5 m/s2). Frying conditions were selected from pre-tests where the physicochemical variables of frying oils (palm olein and avocado oil) were measured. Acrylamide content was measured by GC-MS analyses. The results revealed that the type of oil did not show a significant effect on the physicochemical variables studied. Pre-dried chips showed a decrease in the final oil content of 41-58% (depending on the type of oil used) when compared to two brands of commercial chips. All the detected acrylamide concentrations on the samples were below the detection limit (20 µg/kg). According to our results, avocado oil may also be an option for producing corn tortilla chips.

Risk assessment of exposure to mycotoxins (aflatoxins and fumonisins) through corn tortilla intake in Veracruz City (Mexico).

This study aimed to assess aflatoxin and fumonisin intake through corn tortilla consumption in Veracruz city. Between October 2013 and February 2015, a total of 120 corn tortilla samples (2 kg samples, 40 samples per year) were randomly collected. Aflatoxins and fumonisins were quantified by high performance liquid chromatography coupled with a fluorescence detector. A probability density function (PDF) was used for describing corn tortilla intake, body weight of the Veracruz city population, mycotoxin content of corn tortilla samples and estimated mycotoxin daily intake. The Monte Carlo method with 10,000 iterations was employed to assess the population exposure risk. The highest level of total aflatoxins (AFT) was 22.17 µg kg-1, and 526.6 µg kg-1 for fumonisins B1 plus B2, with 85% and 90% of contaminated samples respectively. Up to 69.7 % of the population was estimated to consume a higher aflatoxin dose than that recommended by the JECFA (1 ng kg-1 of body weight per day); it was found that the recommended dose was exceeded to a greater extent in the male population, due to higher consumption of corn. The risk of fumonisin intake was less than 5 % due to the low presence and levels of these toxins in corn tortillas. The results suggest that corn tortilla consumers are at dietary risk caused by AFT contamination; this information should be considered when taking action to protect public health.

Inactivation of the microbiota and effect on the quality attributes of pineapple juice using a continuous flow ultrasound-assisted supercritical carbon dioxide system.

Supercritical carbon dioxide inactivation technology represents a promising nonthermal processing method, as it causes minimum impact on the nutritional food properties. The aim of this study was to analyze the combined effect of supercritical carbon dioxide and high-power ultrasound on the inactivation of natural microbiota and the quality attributes of pineapple juice treated in a continuous flow system. Different juice residence times (3.06-4.6 min), at 100 bar and 31.5 ℃, were used. The results indicated that the microbiota inactivation was complete and the differences obtained in the quality attributes (2.2% for pH, 4.8% for °Brix, 2% for vitamin C) were minimal. During storage, microorganisms were not able to recover and the vitamin C decrease could be limited to 8.2% after four weeks. The results demonstrated that the supercritical carbon dioxide-high-power ultrasound technique could be an excellent alternative for the cold pasteurization of pineapple juice.

Design of multiloop PI controllers based on quadratic optimal approach.

The LQR methodology is extended to produce multiloop PI controllers in this study. With this method, a multivariable P controller is first obtained and then diagonalized using an iterative procedure. The resulting controller is further complemented with the integral action in a similar process. The proposed tuning process explores different values of the control weight matrix to balance the output error and control signal in both stages, and is refined through additional indices related with the error to reference tracking, disturbance rejection and the associated control use. In addition, the diagonalization procedure is generalized to obtain multiloop versions of existing multivariable PI controllers. The developed theory was applied to the design of multiloop controllers for a distillation column as well as the diagonalization of existing controllers for a nonlinear CSTR. The tuning procedure allowed the synthesis of multiloop PI controllers with performance indices comparable to those reported by other authors. Furthermore, diagonalized controllers exhibited a similar operation as the original multivariable ones.

Statistical analysis of corn consumption for improved mycotoxin exposure estimates for the population of Veracruz City, Mexico.

Corn consumption was evaluated in the population of Veracruz City, Mexico, through two different dietary intake questionnaires. The selection of 300 sampling locations was completely random. The population was segregated into gender and age categories. A daily consumption questionnaire was used to determine the consumption of corn tortillas and a frequency questionnaire to determine the consumption of other corn products. A book of photographs was used to adjust criteria on the size of the portions of corn products and a probability distribution was built of the weight and content of corn for tortillas. Probability density functions (PDFs) were used to describe the consumption of each corn product. Men and those between 14 and 65 years old have the highest consumption of tortillas. Tortillas, antojitos, tacos and chilaquiles are the products that provide the largest amount of corn to the Veracruz people's diet. Even though these products are nixtamalisated, there is evidence that after a thermo-alkaline process some contaminants such as mycotoxins (like aflatoxin, which is a mutagenic, teratogenic and carcinogenic toxin) could be present in high concentrations. These results highlight the need to characterise the consumption of one of the main foods included in dietary staple in Mexico as a first step for a probabilistic risk assessment.

Directional random laser source consisting of a HC-ARROW reservoir connected to channels for spectroscopic analysis in microfluidic devices.

Light sources are used in optofluidic devices for real-time system control and quantitative analysis of important process parameters. In this work, we present a random laser source using a hollow-core antiresonant reflecting optical waveguide (HC-ARROW) containing the gain media inside a reservoir to reduce dye bleaching, which is connected to microchannel waveguides to increase beam directionality. The device is pumped externally and emits a highly coherent and collimated laser beam.

Brewery wastewater treatment using anaerobic inverse fluidized bed reactors.

Two anaerobic inverse fluidized bed reactors were utilized to evaluate organic matter removal from brewery wastewater, applying different OLR and testing two support materials. Hydrodynamic tests varying liquid flow and solid concentration were developed on the supports in order to establish operational conditions. A batch colonization stage was applied using 25% active volume of extendosphere and triturated polyethylene as support materials. The reactors were subsequently operated continuously with stepwise increments in organic loading rate until limiting conditions was reached. For the supports studied, IFBR technology was suitable for organic matter removal present in brewery wastewater with COD removal efficiencies greater than 90%. The reactor with triturated polyethylene support showed an excellent COD removal with OLR values up to 10 g COD/Ld, whereas the reactor with extendosphere support had an excellent hydrodynamic and biologic behavior working with OLR values up to 70 g COD/Ld.

Simultaneous removal of carbon and nitrogen in an anaerobic inverse fluidized bed reactor.

The evaluation of simultaneous removal of carbon and nitrogen in an anaerobic inverse fluidized bed reactor is described. Continuous and batch experiments were used, with synthetic wastewater and glucose as the carbon source with two different nitrate concentrations of 100 and 250 mg N-NO3/L. The evolution of substrates and the concentrations of intermediary products in the gas phase were followed. Results indicate that the use of the biofilm in the inverse fluidized bed reactor allows the expression of denitrification and methanization activities simultaneously without physical or time separation. The removal of nitrogen with both the feeding of 100 and 250 mgN-NO3/L was higher than 90%, while the removal of carbon was 65% on average for the feeding with 100 mgN-NO3/L and 70% on average for the feeding with 250 mg N-NO3/L. This carbon degradation is equivalent to that obtained during the operation of the reactor in the period previous to the nitrate feeding. It was found that by using high values of the COD/N ratio, the dissimilative reduction of nitrates is favoured. Denitrification and anaerobic digestion occurs simultaneously under low values of COD/N.

Effect of physical factors on the production of bacteriocin from Pediococcus acidilactici ITV 26.

The effect of pH, temperature and agitation on growth and bacteriocin production by Pediococcus acidilactici ITV 126 was investigated. Experiments were made in flasks containing MRS medium at 30 to 40 degrees C, pH 5 to 7 and agitation 0 to 200 rpm. Factor levels were arranged in a 2(3) factorial design with central and axial points. Anova and Tukey paired comparison tests showed that a temperature of 35 degrees C favored bacteriocin production, whereas 40 degrees C was best for cell growth. A statistical interaction of temperature and agitation was observed affecting microbial growth. pH 5 favored both cell growth and bacteriocin production.

[Cytogenetics and cytochemistry of leukemia patients in 2 neotropical hospitals]. / Citogenética y citoquímica de pacientes con leucemia en dos hospitales neotropicales.

A cytogenetic and/or cytochemical study was performed in 166 individuals with leukemia or related disorders, in two major Costa Rican hospitals. In those patients treated at an adult's hospital (14 years old and over), acute leukemias represented 66% of all cases. In that hospital the most frequent types of disorders were, in decreasing order: ANLL (> M1), ALL, CML (all of them showed the Ph chromosome) and MDS. In the cases from a childrens' hospital (< 14 years old) acute leukemias were 98%. Among them the order of frequency was: ALL (70%): ALL-1 (84%), ALL-2 (16%) and ANLL (27%): M5a > M3 > M4 > M5b. In ALL 85% were type B and occurred mostly in women while 15% of them were type T and more frequent in males. There was 5.6% infant leukemia, which presented a similar number of acute lymphoids and myeloids. The cytogenetic pattern was similar among Costa Rica and other tropical and temperate countries.

Mutagenic activity of diazepam evaluated by in vivo cytogenetic tests.

BACKGROUND: Diazepam, one of the benzodiazepine group of tranquilizers, is used as an adjunctive drug for sedation and for relief of anxiety in the treatment of epilepsy. Suspicion has been aroused of a possible mutagenic and teratogenic effect of this drug, thus the potential for cancer development. METHODS: To analyze the mutagenic effect of diazepam, the micronuclei and sister chromatid exchange (SCE) tests were performed by in vivo techniques in the bone marrow of Balb-C mice after intraperitoneal drug administration. Sixty mice, 30 males and 30 females, were classified as negative control (n = 12), positive control (n = 12), and three groups were treated with diazepam (n = 36). All groups were matched by sex, and each mouse received a single intraperitoneal injection. Negative control group was injected with physiological saline, positive control group with mitomycin-C at a dose of 0.5 mg/kg of body weight. Treated groups received diazepam, one at 0.1, the other at 0.2, and the last, at 0.4 mg/kg. RESULTS: The results showed a significant increase in the frequency of micronucleated polychromatic erythrocytes at all doses tested for whole population in relation to negative control. The polychromatic/normochromatic erythrocyte ratio showed a significant decrease at doses of 0.1 and 0.4 mg/kg in relation to negative control. The frequency of SCE was significantly higher at doses of 0.2 and 0.4 mg/kg in relation to negative control, the male mice being those affected. CONCLUSIONS: It is concluded that diazepam showed mutagenic and genotoxic effects on bone marrow cells of mice and that it might represent a human health risk.

Activity satellite association and polymorphism of Ag stained nucleolus organizer regions (Ag+ NORs) in lymphocytes from women with cervical uterine cancer.

Thirty five female patients with different stages of neoplastic lesions: cervical intraepithelial neoplasia (CIN) or dysplasia (CIN I and CIN II), in situ carcinoma (CIS), and adenocarcinoma, and 27 healthy women (controls) were studied to determine the activity, satellite association, and polymorphism of Ag stained nucleolus organizer regions (Ag+ NORs) in acrocentric chromosomes in metaphases obtained from peripheral blood lymphocytes. For each person, 25 to 50 metaphases stained with ammoniacal silver technique were scored. The average number of Ag+ NORs was higher in women with adenocarcinoma (7.66 +/- 0.72) than in controls (6.65 +/- 0.74). Non-associated chromosomes showing Ag+ NORs were found more frequently in patients (5.85 +/- 0.88) than in controls (4.81 +/- 0.67). Patients aged 30-39 and 60 or more had an increase of Ag+ NORs (7.99 +/- 1.04, and 7.81 +/- 0.71) with respect to their controls (6.36 +/- 0.052 and 6.17 +/- 0.88), but the frequency of satellite association showed lower values in 50-59 year-old patients (0.75 +/- 0.08) than in controls (1.02 +/- 0.19). The most frequent association in patients was the large type (patients = 38.96%, controls = 30.49%). The partial association showed higher values (6.49%) than controls (2.44%). Otherwise, the spherical association was more frequent for controls (37.80%) than for patients (28.57%). All these differences were statistically significant (p < 0.05). The frequency of Ag+ NORs and the type of polymorphism of satellite association could be related to the neoplastic process, while the frequency of satellite association and of polymorphism of Ag+ NORs seems to be irrelevant.

[Lyme disease in Chile. Prevalence study in selected groups]. / Enfermedad de Lyme en Chile. Estudio de prevalencia en grupos seleccionados.

BACKGROUND: The prevalence of Lyme disease in Chile is unknown. AIM: To study the existence and epidemiology of Lyme disease in Chile. PATIENTS AND METHODS: One hundred eighteen patients with signs or symptoms suggestive of Lyme disease were studied. Antibodies against Borrelia burgdorferi were measured using ELISA and indirect immunofluorescence screening tests. Positive cases were confirmed with ELISA using a purified antigen and Western Blot analysis. Human biological samples and ticks were cultured in BSK-H medium. RESULTS: Five patients, three with dermatological manifestations and two with facial palsy and other neurological symptoms, had antibodies against Borrelia, measured by ELISA and indirect immunofluorescence. However the presence of IgM antibodies by ELISA using purified antigen, was confirmed in only one case. All sera and cerebrospinal fluids were negative on Western Blot Analysis. No plasma, skin, CSF or thick culture yielded Borrelia CONCLUSIONS: We could not confirm the existence of Lyme disease in Chile. Positive screening with negative confirmatory test suggests false positive non-specific reactivity or that local Borrelia are antigenically different compared to North American strains.

Risk estimation of ABO and Rho(D) incompatibility in persons with mono- and polyphyletic surnames in Monterrey, Mexico. Comparison with other Mexican populations.

ABO and Rh(o)(D) blood groups were determined in 3813 males and females affiliated with the Instituto Mexicano del Seguro Social (IMSS) who are residents of the Monterrey Metropolitan Area (MMA) in northeastern Mexico. They were selected by their monophyletic or polyphyletic surnames. The ABO and Rh(o)(D) blood group phenotypes and gene frequencies were determined and based upon these, the risk of incompatibilities was estimated for both marriages (MI) and maternal-fetal incompatibility (MFI). These were compared with those estimated for other populations of residents in the MMA, and in other locations in Mexico, as well as with the two most important ancestral populations, Spanish and Tlaxcaltecan Mexican Indians, with the hypothesis that the percent of risk of ABO and Rh(o)(D) MI and MFI are greater in the population with monophyletic surnames than those with polyphyletic surnames. It was found that for persons with monophyletic and polyphyletic surnames, as well as for the other populations in the MMA and other places in Mexico, their ABO and Rho(D) MI and MFI percent of risk are intermediate to the ones estimated for their ancestry. The percentages of MI and MFI are higher for the persons with monophyletic than for the ones with polyphyletic surnames, other populations from the MMA and those from other locations in Mexico. The risks are higher when the similarity with Spanish increases and are lower when their similarities with the Mexican Indians increase.

Relationships by isonymy between persons with monophyletic and polyphyletic surnames from the Monterrey metropolitan area, Mexico.

Three thousand two hundred eleven males and females who resided and were interviewed in the Monterrey metropolitan area in northeastern México were selected for having 1 of 10 common selected surnames as either their patronymic or matronymic name. Five of the names are considered monophyletic and five are considered polyphyletic. Because each individual has two surnames, information about the name complementary to the selected surname was analyzed using isonymy methods (1) to see the effect of immigration on the genetic composition of the population and (2) to determine the isonymy, the relationship by isonymy within and between the persons with monophyletic and polyphyletic surnames. The percentages of the most common complementary surnames, the coefficients of relationship by isonymy of surnames for a selected surname, and the coefficients of relationship between the selected surnames are higher in the monophyletic than in the polyphyletic surnames, indicating that the persons with monophyletic names still conserve some customs of the founders that possibly increase their degree of endogamy. Perhaps these indicators are inversely related to migration, indicating that the monophyletic surnames have been more stable in Monterrey since it was colonized.

[Anticardiolipin antibodies in connective tissue diseases]. / Anticuerpos anticardiolipinas en enfermedades del tejido conectivo.

The incidence of anticardiolipin (ACL) antibodies in connective tissue disorders other than systemic lupus was investigated in 113 subjects: 68 had rheumatoid arthritis, 23 primary Sjogren syndrome and 22 had systemic sclerosis. VDRL, thromboplastin time and determination of IgG and IgM ACL antibodies (ELISA) were performed in all subjects. Overall, 45% of patients were positive for ACL antibodies, mostly of the IgG variety (90%). No differences were observed among the investigated diseases. Positive ACL antibodies were not related to evidence of antiphospholipid syndrome nor to clinical characteristics of the different diseases. These results confirm that ACL antibodies may be present in connective tissue disorders other than systemic lupus, but they do not predict the development of antiphospholipid syndrome nor help to characterize the severity of the disease.