Consumption of fruits, vegetables and salt in the context of control of type 2 diabetes and hypertension in Kerala, India.

BACKGROUND: Proper diet is necessary to control hypertension and diabetes. This paper describes the combined fruit and vegetable, and salt intake of adults (>=18 years) who were detected to have hypertension or diabetes. METHODS: We analysed the data from a state-wide survey of 12012 adults using the World Health Organization STEPs for NCD risk factor surveillance. We evaluated the recommended intake of fruit and vegetable (>=5 servings/day) and salt (<5 gm/day) across participants divided into four strata, and the probabilities were also estimated using the fitted multiple binary logistic regression models. RESULTS: Overall, 13.9% (95%CI: 12.2%-15.9%) and 29.4% (95%CI: 28%-30.8%) of participants consumed the recommended level of fruit and vegetable, and salt, respectively. Adjusted odds ratios were not significantly different across the four strata based on the status of treatment and control of diabetes or hypertension. The likelihood of following the recommended fruit and vegetable intake was highest for 50-69-year-old females with above high school education, obese, under treatment for diabetes or hypertension, and had normal values of FBS and BP (0.28). The likelihood for recommended salt intake was highest for 50-69-year-old males with above high school education and had normal BMI, under treatment for diabetes or hypertension, and had normal values of FBS and BP (0.69). CONCLUSION: The status of diabetes or hypertension did not show considerable influence in the fruit, vegetable, and salt intake of adults in general. A detailed exploration of the accessibility and acceptability of such recommended intakes in the Kerala context is warranted.

Shape-Based Peak Identity Confirmation in Liquid Chromatography.

Chromatography is used to separate analytes in a mixture. In the absence of a detector providing analyte-specific information, the retention time is used to identify the analyte, typically by comparing the retention time of the unknown with that of a standard. This is the simplest of identification routines, but it remains the most widely used. The challenge is that analyte retention times can and do shift; sole reliance on retention time for identification is not prudent. Retention time is influenced by the total sample concentration, elution of components near the peak of interest, aging of a column, and so on, complicating time window-based identification. We propose a sameness threshold (ST) that is based on numerical comparison of shapes of chromatographic peaks for identification confirmation. We demonstrate shape-based identification confirmation or lack thereof of an unconfirmed peak by comparison with a shape library of standards. In numerous cases we look at, only one analyte in the shape library fits the putative identity. ST can be based on r2, the commonly used coefficient of determination used in regression analysis, or on an "index of width mismatch" that compares the widths of the peaks throughout the available height range.

In situ Generated Ru(0)-HRO@Na-ß From Hydrous Ruthenium Oxide (HRO)/Na-ß: An Energy-Efficient Catalyst for Selective Hydrogenation of Sugars.

A green process for the hydrogenation of sugars to sugar alcohols was designed in aqueous medium using hydrous ruthenium oxide (HRO) as a pre-catalyst supported on Na-ß zeolite. Under optimized reaction conditions, sugars such as xylose, glucose, and mannose converted completely to the corresponding sugar alcohols xylitol, sorbitol, and mannitol with 100% selectivity. The pre-catalyst (HRO) is converted in situ to active Ru(0) species during the reaction under H2, which is responsible for the hydrogenation. The catalyst was recyclable up to five cycles with no loss in activity. The reduction of HRO to the active Ru(0) species is dependent on the reaction temperature and H2 pressure. Ru(0) formation increased and consequently an increased hydrogenation of sugars was observed with an increase in reaction temperature and hydrogen pressure. Further, in situ generation of Ru(0) from HRO was assessed in different solvents such as water, methanol, and tetrahydrofuran; aqueous medium was found to be the most efficient in reducing HRO. This work further demonstrates the use of supported HRO as an efficient pre-catalyst for biomass-based hydrogenation reactions.

Prevalence of risk factors of non-communicable diseases in Kerala, India: results of a cross-sectional study.

OBJECTIVE: To estimate the prevalence of non-communicable disease (NCD) risk factors in Kerala. DESIGN: A community-based, cross-sectional survey. PARTICIPANTS: In 2016-2017 a multistage, cluster sample of 12 012 (aged 18-69 years) participants from all 14 districts of Kerala were studied. MAIN OUTCOME MEASURES: NCD risk factors as stipulated in the WHO's approach to NCD risk factors surveillance were studied. Parameters that were studied included physical activity score, anthropometry, blood pressure (BP), and fasting blood glucose (FBG) and morning urine sample to estimate dietary intake of salt. RESULTS: The mean age was 42.5 years (SD=14.8). Abdominal obesity was higher in women (72.6%; 95% CI 70.7 to 74.5) compared with men (39.1%; 95% CI 36.6 to 41.7), and also higher among urban (67.4%; 95% CI 65.0 to 69.7) compared with rural (58.6%; 95% CI 56.6 to 60.5) residents. Current use of tobacco and alcohol in men was 20.3% (95% CI 18.6 to 22.1) and 28.9% (95% CI 26.5 to 31.4), respectively. The estimated daily salt intake was 6.7 g/day. The overall prevalence of raised BP was 30.4% (95% CI 29.1 to 31.7) and raised FBG was 19.2% (95% CI 18.1 to 20.3). Raised BP was higher in men (34.6%; 95% CI 32.6 to 36.7) compared with women (28%; 95% CI 26.4 to 29.4), but was not different between urban (33.1%; 95% CI 31.3 to 34.9) and rural (29.8%; 95% CI 28.3 to 31.3) residents. Only 12.4% of individuals with hypertension and 15.3% of individuals with diabetes were found to have these conditions under control. Only 13.8% of urban and 18.4% of rural residents did not have any of the seven NCD risk factors studied. CONCLUSION: Majority of the participants had more than one NCD risk factor. There was no rural-urban difference in terms of raised BP or raised FBG prevalence in Kerala. The higher rates of NCD risk factors and lower rates of hypertension and diabetes control call for concerted primary and secondary prevention strategies to address the future burden of NCDs.

Improved Patient-Independent System for Detection of Electrical Onset of Seizures.

PURPOSE: To design a non-patient-specific system to detect the electrical onset of seizures in patients with temporal lobe epilepsy. METHODS: We used EEG data from 29 seizures of 18 temporal lobe epilepsy patients who underwent multiday video-scalp EEG monitoring as part of their presurgical evaluations. We segmented each data set into preictal and ictal phases, and identified spectral entropy, spectral energy, and signal energy as useful features for discriminating normal and seizure conditions. The performance of five different classifiers was analyzed using these features to design an automated detection system. RESULTS: Among the five classifiers, decision tree, k-nearest neighbor, and support vector machine performed with sensitivity (specificity) of 79% (81%), 75% (85%), and 80% (86%), respectively. The other two, linear discriminant algorithm and Naive Bayes classifiers, performed with sensitivity (specificity) of 54% (94%), 47% (96%), respectively. CONCLUSIONS: The support vector machine-based seizure detection system showed better detection capability in terms of sensitivity and specificity measures as compared to linear discriminant algorithm, Naive Bayes, decision tree, and k-nearest neighbor classifiers. CONCLUSIONS: Our study shows that a generalized system to detect the electrical onset of seizures in temporal lobe epilepsy using scalp-recorded EEG is possible. If confirmed on a larger data set, our findings may have significant implications for the management of seizures, especially in patients with drug-resistant epilepsy.

A new suppressor design for low noise performance with carbonate eluents for Ion Chromatography.

Carbonate and bicarbonate based eluents have been applied for ion analysis from the inception of ion chromatography. The product of suppression with carbonate and/or bicarbonate eluent is carbonic acid which is weakly dissociated and tends to outgas. While the act of suppression enhanced the signal for fully dissociated ions and lowered the background to a weakly dissociated level, the overall noise performance, however, varied depending on the suppression mechanism. Chemical suppression with a membrane suppressor yielded low noise performance with carbonate and/or bicarbonate eluents. Electrolytic suppression, on the other hand, resulted in a relatively higher noise with carbonate based eluents when compared to chemical suppression. In this work, we investigated the root cause of noise with electrolytic suppressors and carbonate based eluents. Further, a new electrolytic suppressor design based on a three-electrode design is discussed in this paper and provided low noise performance with carbonate and/or bicarbonate eluents.

Electrostatically attached highly branched anion-exchange phases derived from diamines and diepoxides.

A new synthesis approach for the preparation of highly branched anion exchange materials utilizing diamine and diepoxide reagents is described. Unlike previously reported condensation polymers prepared from primary amine and diepoxide reagents, anion exchange polymers prepared from diamines and diepoxide reagents exhibit exceptionally low affinity for polyvalent ions. Use of anion-exchange materials synthesized utilizing this new synthetic method for the analysis of common inorganic anions is demonstrated.

In-depth analyses of native N-linked glycans facilitated by high-performance anion exchange chromatography-pulsed amperometric detection coupled to mass spectrometry.

Characterization of glycans present on glycoproteins has become of increasing importance due to their biological implications, such as protein folding, immunogenicity, cell-cell adhesion, clearance, receptor interactions, etc. In this study, the resolving power of high-performance anion exchange chromatography with pulsed amperometric detection (HPAE-PAD) was applied to glycan separations and coupled to mass spectrometry to characterize native glycans released from different glycoproteins. A new, rapid workflow generates glycans from 200 µg of glycoprotein supporting reliable and reproducible annotation by mass spectrometry (MS). With the relatively high flow rate of HPAE-PAD, post-column splitting diverted 60% of the flow to a novel desalter, then to the mass spectrometer. The delay between PAD and MS detectors is consistent, and salt removal after the column supports MS. HPAE resolves sialylated (charged) glycans and their linkage and positional isomers very well; separations of neutral glycans are sufficient for highly reproducible glycoprofiling. Data-dependent MS2 in negative mode provides highly informative, mostly C- and Z-type glycosidic and cross-ring fragments, making software-assisted and manual annotation reliable. Fractionation of glycans followed by exoglycosidase digestion confirms MS-based annotations. Combining the isomer resolution of HPAE with MS2 permitted thorough N-glycan annotation and led to characterization of 17 new structures from glycoproteins with challenging glycan profiles.

Is Migration Affecting Prevalence, Awareness, Treatment and Control of Hypertension of Men in Kerala, India?

We assessed hypertension prevalence, awareness, treatment and control among male gulf migrant and non-migrant workers in Kerala state of India. We did a cross sectional survey of 191 migrant and 193 non-migrant men aged 25-64 years selected using a multistage random sampling method. Using World Health Organization STEPS approach, we collected information on demographics, STEP 1 variables and measured STEP-2 variables. Multivariate analysis was used to find the relation between migration and hypertension. Age adjusted hypertension prevalence was 57.6 % among migrants and 31.7 % among non-migrants (p < 0.05). Migrants were more likely to be hypertensive (OR 3.00, 95 % CI 1.83-4.94) than non-migrants after adjusting for age, STEP 1 and STEP 2 variables. Though not statistically significant (p = 0.109), awareness of hypertension was lower among migrants (43.5 %) compared to non migrants (56.9 %). Treatment (migrants: 34 %, non-migrants: 53 %, p < 0.05) and control (migrants: 12 %, non-migrants: 48 %, p < 0.001) of hypertension were lower among migrants. Greater attention to improve the treatment and control of hypertension among migrants is warranted in this population.

Mixing characteristics of mixers in flow analysis. Application to two-dimensional detection in ion chromatography.

Three mixer designs, a back-flow tee mixer (BT), an end-blocked membrane tee mixer (EMT), and a tubular membrane mixer (TM), were fabricated and compared to three commercially available mixers, Visco-Jet Micro mixer (VJM) and HS binary tee mixer with 2 and 10 µL volume (HS-2 and HS-10) mixing cartridges. Internal volumes ranged from 8.3 to 20.3 µL. Performance characteristics were evaluated by the Villermaux-Dushman reaction, noise in baseline conductance upon mixing an electrolyte solution with water, and dispersion/relative dispersion of an injected solute. No single characteristic would uniquely qualify a particular device. In typical postcolumn use when a small reagent flow is added to a principal flow stream using a low-pulsation high-end chromatographic pump, with the worst of these mixers, imperfect mixing accounted for 99.6% of the observed noise. EMT, BT, and TM with asymmetric inlets provided better mixing performances relative to VJM, HS-2, and HS-10 with symmetric inlet ports, especially when the secondary liquid flow rate was much lower than the principal stream-flow rate. Dispersion per unit residence time was singularly large for HS-2. Based on its mixing efficiency and small dispersion, the BT design was found to be the best for practicing postcolumn reaction. As an illustrative application, this was then used to introduce electrogenerated LiOH in a suppressed ion chromatography system to perform sensitive detection of weak acids in a second dimension.

Determination of pharmaceutically related compounds by suppressed ion chromatography: IV. Interfacing ion chromatography with universal detectors.

This work forms the final part of a study investigating gradient elution ion-exchange chromatography of pharmaceutically relevant compounds, aiming at achieving complementary selectivity to reversed-phase HPLC. In this study the coupling of three universal detectors (electro-spray ionisation mass spectrometer (ESI-MS); corona charged aerosol detector (CAD); and evaporative light scattering detector (ELSD)) to suppressed IC using complex elution profiles with potassium hydroxide eluents is demonstrated. The non-volatile ions were removed from the eluent by the suppressor prior to detection, thus allowing a stable detector response, especially with the prototype electrolytic suppressor. The detector response for ten weakly anionic pharmaceuticals followed the expected models and the limits of detection obtained were not compromised by the use of a suppressor, yielding values below 50 ng/mL with MS, low to sub µg/mL levels with CAD and 2-20 µg/mL with ELSD (25 µL injections). When coupled to MS and CAD, the prototype electrolytic suppressor showed percentage relative standard deviations (%RSDs) in peak areas of 0.4-2.5% on average, compared to the chemical suppressor which yielded 1.5-3 fold higher %RSD values for the test analytes. The prototype electrolytic suppressor also generally exhibited wider linear response ranges than the chemical suppressor.

Determination of pharmaceutically related compounds by suppressed ion chromatography: III. Role of electrolytic suppressor design.

For the hyphenation of ion chromatography to nebulising detectors or mass spectrometry, suppression of the non-volatile ionic eluent to water is a required step to avoid elevated detector baselines. Presented here is a study of three new designs of electrolytic suppressors, incorporating high ion-exchange capacity screens and high ion-exchange capacity membranes in different thickness and compositions. These designs aim to minimise hydrophobic interactions of the suppressor with organic analytes and to provide higher compatibility with eluents containing acetonitrile. In comparison with a commercially available electrolytic suppressor and also a commercially available chemical suppressor, the new high-capacity suppressor showed superior performance, exhibiting minimal interactions with a test set of analytes under the examined conditions. This led to the attainment of high recoveries of the analytes after suppression (93-99% recovery) and significantly reduced band broadening during suppression. The new suppressor has been shown to perform well under both isocratic and gradient elution conditions.

Electrodialytic membrane suppressors for ion chromatography make programmable buffer generators.

The use of buffer solutions is immensely important in a great variety of disciplines. The generation of continuous pH gradients in flow systems plays an important role in the chromatographic separation of proteins, high-throughput pK(a) determinations, etc. We demonstrate here that electrodialytic membrane suppressors used in ion chromatography can be used to generate buffers. The generated pH, computed from first principles, agrees well with measured values. We demonstrate the generation of phosphate and citrate buffers using a cation-exchange membrane (CEM) -based anion suppressor and Tris and ethylenediamine buffers using an anion-exchange membrane (AEM) -based cation suppressor. Using a mixture of phosphate, citrate, and borate as the buffering ions and using a CEM suppressor, we demonstrate the generation of a highly reproducible (avg RSD 0.20%, n = 3), temporally linear (pH 3.0-11.9, r(2) > 0.9996), electrically controlled pH gradient. With butylamine and a large concentration (0.5 M) of added NaCl, we demonstrate a similar linear pH gradient of large range with a near-constant ionic strength. We believe that this approach will be of value for the generation of eluents in the separation of proteins and other biomolecules and in online process titrations.

pH- and concentration-programmable electrodialytic buffer generator.

We have presented in a companion paper a suppressor-based electrodialytic buffer generator (EBG) that can produce programmable pH gradients. Here we demonstrate a three-electrode EBG. In this three-compartment flow-through device, the central compartment is separated from the outer compartments with a cation-exchange membrane (CEM) and an anion-exchange membrane (AEM), respectively. One platinum electrode is disposed in each compartment. The flows through each compartment are independent. With appropriate solutions in each compartment, independent potentials are applied to the CEM and AEM electrodes with respect to the grounded central electrode. The CEM current and the AEM current can be independently manipulated to generate buffers with variable concentration and pH in the central compartment. Both the CEM and AEM currents can be positive or negative. For the CEM, a positive current (i(cat)(in)) indicates that cations are coming in from the CEM channel to the center. A negative current (i(cat)(out)) takes cations out of the center to the CEM channel. Similarly for the AEM, currents governing anion transport into the center channel from the AEM channel (AEM electrode negative) or the reverse (AEM electrode positive) are respectively denoted by i(an)(in) or i(an)(out). Most examples herein involve inward ion transport, referred to as the additive mode. Depending on whether i(cat)(in) i(an)(in), H(+)/O(2) and OH(-)/H(2) are respectively produced at the central electrode to maintain electroneutrality. Any gas formed is subsequently removed by a gas removal device. The pH of the central channel effluent is related to the ratio of the currents through the two membranes, while the generated concentration is controlled by the absolute value of the currents. The buffer concentration and pH can be varied in a controlled predictable manner. A pH span of 3-12 was attained and a phosphate buffer concentration up to 140 mM was generated. We demonstrate a variety of combined pH/concentration gradients from a mixture of ethylenediamine, citrate, and phosphate by manipulating i(cat)(in), which controls introduction of the ethylenediammonium ion, and i(an)(in), which controls the introduction of citrate and phosphate ions. We also demonstrate an additive-subtractive mode of operation where both inward and outward currents are used to add one type of ion while removing another type of ion to reproducibly generate pH/concentration gradients.

Fat extraction from acid- and base-hydrolyzed food samples using accelerated solvent extraction.

This paper describes a new in-cell method for pursuing accelerated solvent extraction (ASE) prior to lipid analysis from food samples. It is difficult to pursue direct ASE with acid- or base-hydrolyzed samples due to the corrosive nature of the reagents and material limitations. In this study ion exchange based materials were used to remove acid or base reagents in-cell without compromising the recovery of lipids. The performance data are presented here for the new methods for lipid extraction for a variety of food samples and compared to the Mojonnier method. NIST Standard Reference Materials (SRM-1546 and SRM-1849) were used to validate the ASE methods. Excellent fat recoveries were obtained for the ASE methods. The new methods presented here enhance the utility of ASE and eliminate labor intensive protocols.

Charge detector for the measurement of ionic solutes.

We describe a flow-through ionic charge detector in the form of a three-compartmented system. A central water channel is separated from two outer channels bearing water (or a dilute electrolyte) by a cation-exchange membrane (CEM) and an anion-exchange membrane (AEM). Independent fluid input/output ports address all channels. One platinum electrode is put in each outer channel. When the AEM-side electrode is positive with respect to the CEM-side electrode and voltage (approximately 1-10 V) is applied, the observed background current is from the transport of H(+)/OH(-) through the CEM/AEM to the negative/positive electrodes, respectively. The H(+) and OH(-) are generated by the ionization of water, in part aided by the electric field. If an electrolyte (X(+)Y(-)) is injected in to the central channel, X(+) and Y(-) migrate through the CEM and AEM to the negative and positive electrodes, respectively, and generate a current pulse. The integrated area of the current signal (coulombs) elicited by this electrolyte injection is dependent on a number of variables, the most important being the central channel residence time and the applied voltage (V(app)); these govern the transport of the injected electrolyte to/through the membranes. Other parameters include electrode placement, fluid composition, and outer channel flow rates. For strong electrolytes, depending on the operating conditions, the current peak area (hereinafter called the measured charge signal, Q(m)) can both be less or more than the charge represented by the electrolyte injected (Q(i)). Q(m) is less than Q(i) if transport to/through the membranes is subquantitative. Q(m) can be greater than Q(i) at higher V(app). At constant V(app) more voltage is dropped across the membranes as the central channel becomes more conductive and water dissociation at the membrane surface is enhanced. Effectively, the membranes experience a greater applied voltage as the central channel becomes more conductive. The resulting additional current accompanying analyte introduction to the detector can substantially augment Q(m). Thus, the device is not an absolute coulometer although V(app) can be deliberately chosen to have Q(m) = Q(i) over at least a 10-fold concentration range. Importantly, equivalent amounts of diverse strong electrolytes (with substantially different conductivities) injected into the central channel produce the same charge signals. In ion chromatography, this results in identical calibration curves for all strong acid anions, obviating individual calibrations. Whereas with a conductivity detector (CD) only the ionized portion of a weak electrolyte responds, in the present charge detector (ChD), ions are actually removed, leading to further ionization and the detection of a proportionately greater analyte amount.

Postcolumn concentration in liquid chromatography. On-line eluent evaporation and analyte postconcentration in ion chromatography.

On-line sample concentration by evaporation through a narrow-bore membrane tube is described. The device can be deployed just prior to the detector or the sample may be concentrated prior to injection. As solution flows through a solvent-permeable membrane tube, (heated) drying gas (nitrogen/air) flows outside it to remove the solvent. The removal rate increases with increasing sample residence time, drying gas flow rate, and temperature. Various membranes and three concentrator designs (a rectangular maze, a serpentine and a filament-filled helix, the last performing the best) were fabricated and tested for post- and preseparation applications in suppressed anion chromatography. An order of magnitude concentration factors are readily obtained. The present system involves active mass transport radially outward through the walls of a tube. This is a system in which many of the traditional paradigms of flow through a tubular conduit no longer hold true. Because the flow rate continuously varies along the tube, residence time does not scale linearly with residence volume or conduit length. The effects of such mass transport on the parabolic velocity profile of laminar flow remain unknown.

Matrix diversion methods for improved analysis of perchlorate by suppressed ion chromatography and conductivity detection.

Two inline matrix diversion methods were developed for the sensitive analysis of perchlorate in a matrix comprising up to 1000 mg l(-1) of chloride, sulfate and bicarbonate ions using suppressed ion chromatography and conductivity detection. The first method used a cryptand C1 concentrator column, which exhibited a high selectivity for perchlorate ion over the other matrix anions. After retaining the sample anions in a concentrator column derivatized with a crytpand phase, a rinse step was implemented with a weak base to divert the matrix ions to waste while selectively retaining perchlorate in the concentrator column for subsequent analysis. The analysis was done using a 2mm IonPac AS16 or 2 mm IonPac AS20 separator column. The second method was a two-dimensional matrix diversion method with a focus on improving the detection sensitivity. The first dimension was used to achieve some resolution of the matrix ions from perchlorate. The perchlorate ion was then diverted into a concentrator column for subsequent analysis in the second dimension. By pursuing analysis using a 4mm IonPac AS16 or IonPac AS20 column in the first dimension and subsequently pursuing analysis using a 2mm IonPac AS16 or IonPac AS20 column format, excellent sensitivities were achieved when the first and second dimensions were operated at the same linear flow velocity (cm min(-1)). While sensitive detection of perchlorate in the low microg l(-1) regime was achieved by the above methods in the presence of matrix ions, superior recovery for perchlorate was demonstrated under a variety of matrix concentrations by the second method.

Asymmetric membrane fiber-based carbon dioxide removal devices for ion chromatography.

The application of hollow and filament-filled single asymmetric membrane fibers, consisting of a thin silicone layer on a tubular microporous support, for removing CO(2) in suppressed ion chromatography effluents is described. With appropriate choice of the removal device and operating conditions, the CO(2) can be essentially quantitatively (99+%) removed. For carbonate-based eluents, the use of such devices greatly reduces or eliminates the water dip, permitting better quantitation of poorly retained anions that elute close to the dip, allows practical gradient chromatography, and improves noise levels and attainable detection limits. In hydroxide eluent chromatography, the device largely removes the response from CO(2) present in the samples; this greatly aids atmospheric trace gas analysis by IC. Device dimensions are such that the dispersion introduced by the device is small.

Recent developments in electrolytic devices for ion chromatography.

Recent developments in new electrolytic devices that utilize the electrolysis of water and charge-selective electromigration of ions through ion-exchange media have significantly changed the routine operation of ion chromatographic methods. Examples of these new electrolytic devices include on-line eluent generators that produce high-purity electrolyte eluents using deionized water as the carrier stream, continuously regenerated trap columns that remove ionic contaminants in the eluents, and continuously regenerated suppressors that reduce eluent background conductance prior to conductivity detection. The combined use of these electrolytic devices has made it possible to perform various ion chromatographic separations using only deionized water as the mobile phase. This paper reviews the operation principles of these electrolytic devices and their applications in the ion chromatographic determination of anionic and cationic analytes.