Category: Nevin Manimala

Arch Oral Biol. 2021 May 27;128:105171. doi: 10.1016/j.archoralbio.2021.105171. Online ahead of print.

ABSTRACT

OBJECTIVES: We aimed to determine the aetiologic agent responsible for black staining of permanent dentition using next-generation sequencing and determine the relationship between caries and black stains.

MATERIALS AND METHODS: A total of 52 systemically healthy patients with black-stained and caries-free (n = 13), black-stained and carious (n = 13), black stain-free and caries-free (n = 13), and black stain-free and carious (n = 13) teeth were enrolled in the study. The International Caries Detection and Assessment System (ICDAS II) was used for caries classification. Between 08:00 and 10:00, supragingival plaque samples were collected after a minimum of 8-12 h of accumulation and DNA samples were isolated. The samples were processed using the ZymoBIOMICS™ Service. Bioinformatics analysis was performed using mothur at usegalaxy.org. Data were analysed statistically using the Pearson chi-square and Fisher tests.

RESULTS: The number of caries-free teeth (ICDAS 0, 1, and 2) was significantly higher in patients with black stains (p = 0.007).Capnocytophaga (4.8 %), Corynebacterium (3.9 %), and Neisseria (5.4 %) species were the most abundant among all black-stained plaques (carious and caries-free) (p < 0.05). Capnocytophaga (10.8 %), Cardiobacterium (3.6 %), and Rothia (1.72 %) species were detected in the black-stained plaques of caries-free patients (p < 0.05).

CONCLUSION: This study is one of the first studies examining the microbial composition of dental plaques with black staining in carious and caries-free adult patients using next generation sequencing technology. In the presence of black staining, plaques have an ultimate complex microbial structure. A lower caries burden was noted in the presence of black staining.

PMID:34058724 | DOI:10.1016/j.archoralbio.2021.105171

Food Chem. 2021 May 21;361:130166. doi: 10.1016/j.foodchem.2021.130166. Online ahead of print.

ABSTRACT

Use of ‘green biomass’ of the grapevine is gradually extending into the food industry. The aim of our study was to demonstrate the potential of metabolomic fingerprinting for characterization of grapevine leaves and canes. Our method comprises successive aqueous-methanolic extractions, followed by U-HPLC-HRMS/MS. For data processing, PCA and (O)PLS-DA methods were utilized, and mathematical models were validated. We showed that from all factors investigated, harvesting season explained most of the variability between samples, followed by locality combined with farming system. The identified statistically significant metabolites for harvesting season models mostly represented the groups of fatty acids, fatty phenols, (lyso)phospholipids, flavonoids and organic acids. For models of localities with different farming systems, majority of identified metabolites significant for organic farming belonged to groups of fatty acids and their derivatives, terpenoids, sterols, and fat soluble vitamins, whereas for conventional farming, the only identified significant metabolites were the pesticide residues.

PMID:34058658 | DOI:10.1016/j.foodchem.2021.130166

Stud Hist Philos Sci. 2021 May 28;88:60-69. doi: 10.1016/j.shpsa.2021.04.001. Online ahead of print.

ABSTRACT

In what sense are associations between particular markers and complex behaviors made by genome-wide association studies (GWAS) and related techniques discoveries of, or entries into the study of, the causes of those behaviors? In this paper, we argue that when applied to individuals, the kinds of probabilistic ’causes’ of complex traits that GWAS-style studies can point towards do not provide the kind of causal information that is useful for generating explanations; they do not, in other words, point towards useful explanations of why particular individuals have the traits that they do. We develop an analogy centered around Galton’s “Quincunx” machine; while each pin might be associated with outcomes of a certain sort, in any particular trial, that pin might be entirely bypassed even if the ball eventually comes to rest in the box most strongly associated with that pin. Indeed, in any particular trial, the actual outcome of a ball hitting a pin might be the opposite of what is usually expected. While we might find particular pins associated with outcomes in the aggregate, these associations will not provide causally relevant information for understanding individual outcomes. In a similar way, the complexities of development likely render impossible any moves from population-level statistical associations between genetic markers and complex behaviors to an understanding of the causal processes by which individuals come to have the traits that they in fact have.

PMID:34058686 | DOI:10.1016/j.shpsa.2021.04.001

J Mech Behav Biomed Mater. 2021 May 23;120:104569. doi: 10.1016/j.jmbbm.2021.104569. Online ahead of print.

ABSTRACT

Implants for the cure of female genital prolapse still show numerous complications cases that sometimes have dramatic consequences. These implants must be improved to provide physiological support and restore the normal functionalities of the pelvic area. Besides the trend towards lighter meshes, a better understanding of the in vivo role and impact of the mesh implantation is required. This work investigates the mechanical impact of meshes after implantation with regards to the behavior of the native tissues. Three meshes were studied to assess their mechanical and biological impact on the native tissues. An animal study was conducted on rats. Four groups (n = 17/group) underwent surgery. Rats were implanted on the abdominal wall with one of the three polypropylene knitted mesh (one mesh/group). The last group served as control and underwent the same surgery without any mesh implantation. Post-operative complications, contraction, mechanical rigidities, and residual deformation after cyclic loading were collected. Non-parametric statistical comparisons were performed (Kruskal-Wallis) to observe potential differences between implanted and control groups. Mechanical characterization showed that one of the three meshes did not alter the mechanical behavior of the native tissues. On the contrary, the two others drastically increased the rigidities and were also associated with clinical complications. All of the meshes seem to reduce the geometrical lengthening of the biological tissues that comes with repetitive loads. Mechanical aspects might play a key role in the compatibility of the mesh in vivo. One of the three materials that were implanted during an animal study seems to provide better support and adapt more properly to the physiological behavior of the native tissues.

PMID:34058600 | DOI:10.1016/j.jmbbm.2021.104569

J Psychiatr Res. 2021 May 23;139:125-131. doi: 10.1016/j.jpsychires.2021.05.039. Online ahead of print.

ABSTRACT

Maternal infection is thought to increase the risk of non-affective psychosis including schizophrenia. However, observational studies have produced conflicting results and little is known about the importance of timing of infection in mediating subsequent risk. In this study, we carried out a meta-analysis of observational studies to investigate the risk of maternal infection and subsequent risk of non-affective psychosis. Using seven cohort studies, we found that maternal infection during gestation increased the risk of non-affective psychosis [relative risk (RR): 1.28 (95% CI:1.05-1.57, p = 0.02, I² = 36%)]. A subgroup analysis identified that there was greater risk for schizophrenia alone [RR: 1.65 (95% CI:1.23-2.22, p = 0.0008, I² = 0%)]. In addition, infection during the second trimester resulted in increased risk [RR: 1.63 (95% CI:1.07-2.48, p = 0.02, I² = 7%)], whilst risk during the first and third trimesters did not meet statistical significance. This study highlights maternal infection in gestation as an important environmental risk factor for non-affective psychosis and our findings carry important implications for future disease prevention strategies.

PMID:34058651 | DOI:10.1016/j.jpsychires.2021.05.039

Sci Total Environ. 2021 May 25;789:147882. doi: 10.1016/j.scitotenv.2021.147882. Online ahead of print.

ABSTRACT

Indoor air purifiers are increasingly marketed for their health benefits, but their cardiovascular effects remain unclear. We systematically reviewed and meta-analysed randomized controlled trials (RCTs) on the cardiovascular effects of indoor air purification interventions in humans of all ages. We searched Embase, Medline, PubMed, and Web of Science from inception to 22 August 2020. Fourteen cross-over RCTs (18 publications) were included. Systolic blood pressure (SBP) was significantly reduced after intervention (-2.28 (95% CI: -3.92, -0.64) mmHg). There were tendencies of reductions in diastolic blood pressure (-0.35 [-1.52, 0.83] mmHg), pulse pressure (PP) (-0.86 [-2.07, 0.34] mmHg), C-reactive protein (-0.23 [-0.63, 0.18] mg/L), and improvement in reactive hyperaemia index (RHI) (0.10 [-0.04, 0.24]) after indoor air purification, although the effects were not statistically significant. However, when restricting the analyses to RCTs using physical-type purifiers only, significant improvements in PP (-1.56 [-2.98, -0.15] mmHg) and RHI (0.13 [0.01, 0.25]) were observed. This study found potential evidence on the short-term cardiovascular benefits of using indoor air purifiers, especially for SBP, PP and RHI. However, under the Grading of Recommendations Assessment, Development and Evaluation framework, the overall certainty of evidence was very low, which discourage unsubstantiated claims on the cardiovascular benefits of air purifiers. We have also identified several key methodological limitations, including small sample size, short duration of intervention, and the lack of wash-out period. Further RCTs with larger sample size and longer follow-up duration are needed to clarify the cardiovascular benefits of air purification interventions.

PMID:34058577 | DOI:10.1016/j.scitotenv.2021.147882

J Mech Behav Biomed Mater. 2020 Nov 17;120:104205. doi: 10.1016/j.jmbbm.2020.104205. Online ahead of print.

ABSTRACT

We characterized a set of eleven clinically relevant formulations of UHMWPE for total joint replacements. Although their molecular and supermolecular structure were quite similar as evidenced by IR, DSC and SAXS measurements, there were slight differences in their crystallinity (DSC crystallinity ranging from 52 to 61%), which were connected with processing conditions, such as the total radiation dose, thermal treatment and/or addition of biocompatible stabilizers. Mechanical properties were assessed at all length scales, using macroscale compression testing, non-instrumented and instrumented microindentation hardness testing (at loading forces ~500 mN), and nanoindentation hardness testing measured at both higher and lower loading (~4 mN and ~0.6 mN, respectively). In agreement with theoretical predictions, we found linear correlations between UHMWPE crystallinity and its stiffness-related properties (elastic moduli, yield stress, and hardness) at all length scales (macro-, micro- and nanoscale). Detailed statistical evaluation of our dataset showed that the accuracy and precision of the applied methods decreased in the following order: non-instrumented microindentation ≥ instrumented microindentation ≥ macromechanical properties ≥ nanoindentation measured at higher loading forces ≫ nanoindentation measured at lower loading forces. The results confirm that microindentation and nanoindentation at sufficiently high loading forces are reliable methods, suitable for UHMWPE characterization.

PMID:34058599 | DOI:10.1016/j.jmbbm.2020.104205

Sci Total Environ. 2021 May 24;789:147966. doi: 10.1016/j.scitotenv.2021.147966. Online ahead of print.

ABSTRACT

Accurate source markers, source profiles and species-based emission factors (EFs) are currently the key limitations for source apportionment and emission inventory researches. Fine particles (PM_2.5) were collected from stack gases of eight types of stationary sources with a dilution sampling system. The mass percentages and EFs of 89 kinds of chemical species in PM_2.5 including water-soluble ions, elements, carbonaceous species and molecular organic species were obtained. Results showed that water-soluble ions (8%-54%) and elements (5%-45%) were the dominant chemical species. Palmitic acid (0.19%-0.62%) and stearic acid (0.21%-0.59%) were the most abundant organic species. PM_2.5 source profiles of the eight sources were different from each other with the coefficient of divergence values all higher than 0.4. The addition of organic species could help to further distinguish them. The indicatory chemical components and specific species ratios were obtained by both a statistical equation and randomForest. These indicatory chemical components (e.g. F^– for glass factory) and species ratios (e.g. K⁺/Mg²⁺ & OC/Mg for pharmaceutical factory) improved the current knowledges of their indicatory performance in source identification of ambient PM_2.5. The EFs of PM_2.5 from the eight stationary sources ranged from 0.019 to 51.6 kg t^-1 of fuel used. The EFs of PM_2.5 from the pharmaceutical factory were about 70-2600 times higher than other seven types of sources due to the lack of dust-removing devices. Certain EFs measured in this study were about 10-36,000 times lower than corresponding EFs estimated in previous studies which didn’t perform field measurements, indicating the necessity for improving emission inventories continuously. This study contributes to identifying emission sources of PM_2.5 especially for subtypes of stationary sources and to establishing species-based emission inventories.

PMID:34058574 | DOI:10.1016/j.scitotenv.2021.147966

Sci Total Environ. 2021 May 24;789:147952. doi: 10.1016/j.scitotenv.2021.147952. Online ahead of print.

ABSTRACT

Forest cover improves surface water quality by minimizing soil erosion, reducing sediment in water and trapping or filtering water pollutants in forest litter. Because the amount of chemicals needed to produce potable water depends on the quality of intake water, upstream forest cover protection may help reduce the extent and cost of water treatment downstream. However, many other drivers exist for the cost of water treatment, so the magnitude and relevance of the influence of forest cover on water treatment cost is an empirical question. We analyze the impact of forest cover on the quality of raw water and the extent of water treatment required at the water treatment plants in Costa Rica, using monthly panel data in 2008-2014 from the drinking water treatment plants managed by the national public utility. We find that forest cover change during the study period statistically significantly affected the chemical use by water treatment plants. In economic terms, the estimated value of water purification service provided by forests is USD 9.5 per hectare per year. Depending on the discount rate, this results in a net present value of water purification service ranging between USD 315.4 and USD 113.9 per hectare. The results indicate that the economic value of the water purification service of forest is 1.7% of the value for recreational services; between 3.2% and 1.1% relative to the value of forest carbon sequestration typical in Costa Rica, depending on the discount rate; and around 13% of the payments for watershed protection program by the National Forest Financing Fund. The results also show that the marginal contribution of forest, on a per hectare basis, on water quality becomes larger as the size of catchment decreases.

PMID:34058576 | DOI:10.1016/j.scitotenv.2021.147952

J Pharm Biomed Anal. 2021 May 24;202:114165. doi: 10.1016/j.jpba.2021.114165. Online ahead of print.

ABSTRACT

The purpose of this study is to elucidate uncertainty structures of internal standard (IS) methods as compared with absolute calibration methods in liquid chromatography. A quantitative test of indomethacin with butyl 4-hydroxybenzoate as an IS in high-performance liquid chromatography with ultra-violet detection is taken here as an example. The repeatability is evaluated by both a usual statistical method of repetition and a theoretical approach, called the function of mutual information (FUMI) theory. The latter predicts the precision from noise and signals of instrumental output. Plots of relative standard deviations (RSDs) of measurements against analyte amounts, called precision profiles, are compared between the IS methods for indomethacin and their corresponding absolute calibration methods over a wide range of amount. Sample injection errors are observed to be effectively eliminated at high amounts by the IS methods, but at low amounts where background random noise dominates over the other error, the superiority of the IS methods is overshadowed and the precision of both the methods is almost comparable. The smallest possible amount of IS material without spoiling the integrity of analysis is estimated from the precision profiles.

PMID:34058536 | DOI:10.1016/j.jpba.2021.114165