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Nevin Manimala Statistics

Accurate method for rapid biomass quantification based on specific absorbance of microalgae species with biofuel importance

Lett Appl Microbiol. 2021 Jun 5. doi: 10.1111/lam.13519. Online ahead of print.

ABSTRACT

The development of microalgae culture technology has been an integral part to produce biomass feedstock to biofuel production. Due to this, numerous attempts have been made to improve some operational parameters of microalgae production. Despite this, specialized research in cell growth monitoring, considered as a fundamental parameter to achieve profitable applications of microalgae for biofuels production, presents some opportunity areas mainly related to the development of specific and accurate methodologies for growth monitoring. In this work, predictive models were developed through statistical tools that correlate a specific microalgal absorbance with cell density measured by cell count (cells∙mL-1 ), for three species of interest for biofuels production. The results allow the precise prediction of cell density through a logistic model based on spectrophotometry, valid for all the kinetics analyzed. The adjusted determination coefficients (r2adj ) for the developed models were 0.993, 0.995 and 0.994 for Dunaliella tertiolecta, Nannochloropsis oculata and Chaetoceros muelleri, respectively. The results showed that the equations obtained here can be used with an extremely low error (≤ 2%) for all the cell growth ranges analyzed, with low operational cost and high potential of automation. Finally, a user-friendly software was designed to give practical use to the developed predictive models.

PMID:34091927 | DOI:10.1111/lam.13519

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Quantifying the demographic vulnerabilities of dry woodlands to climate and competition using range-wide monitoring data

Ecology. 2021 Jun 5:e03425. doi: 10.1002/ecy.3425. Online ahead of print.

ABSTRACT

Climate change is expected to alter the distribution and abundance of tree species, impacting ecosystem structure and function. Yet, anticipating where this will occur is often hampered by a lack of understanding of how demographic rates, most notably recruitment, vary in response to climate and competition across a species range. Using large-scale monitoring data on two dry woodland tree species (Pinus edulis and Juniperus osteosperma), we develop an approach to infer recruitment, survival, and growth of both species across their range. In doing so, we account for ecological and statistical dependencies inherent in large-scale monitoring data. We find that drying and warming conditions generally lead to declines in recruitment and survival, but the strength of responses varied between species. These climate conditions point to geographic regions of high vulnerability for particular species, such as Pinus edulis in N. Arizona, where both survival and recruitment are low. Our approach provides a path forward for leveraging emerging large-scale monitoring and remotely sensed data to anticipate the impacts of global change on species distributions.

PMID:34091890 | DOI:10.1002/ecy.3425

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Safely increasing nephro-ureteric stent exchange intervals, resulting in significant cost savings for the interventional radiology suite, a 2-year experience in a tertiary referral centre

Ir J Med Sci. 2021 Jun 5. doi: 10.1007/s11845-021-02657-5. Online ahead of print.

ABSTRACT

AIM: To evaluate the nephro-ureteric stent (NUS) insertion and exchange practice in a tertiary referral cancer centre, and determine the safety and compliance with current guidelines. We also reviewed if increasing exchange time interval from 6 to 12 weeks was safe, and if this could be adopted into our local guidelines.

METHODS: A retrospective review was performed covering 24 months from January 2017 to December 2018. All NUS insertions and exchanges performed in that period were analysed, including the number of exchanges the patient underwent, the time between subsequent exchanges, and the screening time. We also reviewed the indications for stent insertion, possible causes for failed stent exchange, and factors which led to significant delays in stent exchanges for some patients. A scatterplot of screening time versus time in situ was derived and correlation analysis performed using the Pearson coefficient.

RESULTS: Thirty-two patients underwent de novo NUS insertion during the period, and 102 NUS exchanges were performed. The interval between stent exchanges ranged from 1 to 40 weeks, with a mean of 12.3 weeks (SD = 8.96 weeks). Screening time ranged from 33 s to 17 min, with a mean of 3 min 50 s (SD = 3 min 35 s). There were 100 successful exchanges, and two failed exchanges, accounting for 1.9% of total exchanges. In both failed cases, the reason for failed exchange was due to a prolonged period between exchanges (6 months in both cases). The reason for delay for stent exchange was due to non-attendance for scheduled appointments. There was a weakly positive correlation coefficient of 0.06 (screening time versus time period between insertions); however, this was not statistically significant (p = 0.81).

CONCLUSION: In this retrospective review, we have demonstrated that the recommended 6-week period between stent exchanges is unnecessary in the vast majority of cases, and that a longer interval between NUS exchanges, e.g. 8-12 weeks, is safe for the patient, and reduces screening time. This reduction in procedures also provides a significant potential saving to the radiology department in both monetary expense and limited angiography suite time.

PMID:34091859 | DOI:10.1007/s11845-021-02657-5

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Analysis of Mercury Concentration in Honey from the Point of View of Human Body Exposure

Biol Trace Elem Res. 2021 Jun 6. doi: 10.1007/s12011-021-02744-9. Online ahead of print.

ABSTRACT

Honey is a highly valued product due to its nutritional value, pro-health and healing properties. Pollutants from the environment penetrate into nectar, honeydew, pollen and next into bee products and can cause human exposure after ingestion. Mercury (Hg) is a toxic metal to living organisms. This is why it was important to determine the level of Hg in consumed honey.The aim of this manuscript is to analyse mercury concentration in honeys collected on the territory of Poland. A total of 108 samples of honey purchased in regional apiaries and hypermarkets were tested. The concentration of Hg was analysed in various types of honey (multifloral, honeydew, linden, goldenrod, acacia, buckwheat, rapeseed, sunflower, heather, dandelion, phacelia). The values of the Estimated Daily Intake (EDI), Estimated Weekly Intake (EWI) and % Provisional Tolerable Weekly Intake (% PTWI) were calculated. This allowed estimating the amount of Hg taken during consumption of the tested honeys.The concentration of Hg ranged from 0.01 to 1.71 µg/kg and was 0.43 µg/kg on average. A higher concentration of Hg, which was statistically significant, was recorded in honeydew honey, then in compound honeys. Honeys produced from one raw material had the lowest concentration of Hg. There were no significant differences in the concentration of Hg depending on the origin of honey. The calculations have shown that consumption of a portion (19 g) of the tested honey per week is safe for both adults and children according to the applicable standards.

PMID:34091870 | DOI:10.1007/s12011-021-02744-9

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A Comparison of 1000 Hz to 30 Hz Spinal Cord Stimulation Strategies in Patients with Unilateral Neuropathic Leg Pain Due to Failed Back Surgery Syndrome: A Multicenter, Randomized, Double-Blinded, Crossover Clinical Study (HALO)

Pain Ther. 2021 Jun 6. doi: 10.1007/s40122-021-00268-7. Online ahead of print.

ABSTRACT

INTRODUCTION: Multicenter, randomized, double-blinded crossover study. The Netherlands (ClinicalTrials.gov NCT02112474). We hypothesized that the pain suppressive effects of 1000 Hz and 30 Hz spinal cord stimulation (SCS) strategies are equally effective in patients with chronic, neuropathic, unilateral leg pain after back surgery.

METHODS: Thirty-two patients (18-70 years, minimum leg pain 50 mm on 100 mm visual analog scale (VAS), minimal back pain) were randomized (1:1) to start 1000 Hz or 30 Hz neurostimulation for 9 days. After a 5-day washout, they crossed over, for another 9 days. Primary outcome was pain suppression (mean of VAS scores 4×/day) during the crossover period. The main investigators were blinded to strategy allocation, patients were blinded to the outcome, a blinded assessor analyzed the primary outcome.

RESULTS: The primary outcome was analyzed in 26 patients. There was no period effect (delta 4 mm, p = 0.42, 95% CI [- 5, 13]), allowing direct intrapatient comparison of the treatment effect (delta 1 mm, p = 0.92, 95% CI [- 13, 14]). Ninety-two percent of patients in both periods experienced greater than 34% pain suppression (minimal clinically important difference, MCID). Secondary outcomes (22 patients): pain suppression and improved quality of life were sustained at 12 months; both were statistically significant and clinically relevant. Fifty percent of patients had greater than 80% pain suppression (p < 0.001). At study termination, all events were resolved; no unanticipated events were reported. Medtronic provided a grant for additional study costs.

CONCLUSION: We conclude that our hypothesis regarding the effect of 1000 Hz and 30 Hz stimulation strategies on pain suppression was confirmed. Both stimulation strategies led to a large, sustainable, clinically relevant pain suppression and improvement in quality of life.

PMID:34091818 | DOI:10.1007/s40122-021-00268-7

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New method for quantification of intratumoral heterogeneity: a feasibility study on Ktrans maps from preclinical DCE-MRI

MAGMA. 2021 Jun 6. doi: 10.1007/s10334-021-00930-3. Online ahead of print.

ABSTRACT

OBJECT: To develop new imaging biomarkers of therapeutic efficacy through the quantification of intratumoral microvascular heterogeneity.

MATERIALS AND METHODS: The described method was a combination of non-supervised clustering and extraction of intratumoral complexity features (ICF): number of non-connected objects, volume fraction. It was applied to a set of 3D DCE-MRI Ktrans maps acquired previously on tumor bearing mice prior to and on day 4 of anti-angiogenic treatment. Evolutions of ICF were compared to conventional summary statistics (CSS) and to heterogeneity related whole tumor texture features (TF) on treated (n = 9) and control (n = 6) mice.

RESULTS: Computed optimal number of clusters per tumor was 4. Several intratumoral features extracted from the clusters were able to monitor a therapy effect. Whereas no feature significantly changed for the control group, 6 features significantly changed for the treated group (4 ICF, 2 CSS). Among these, 5 also significantly differentiated the two groups (3 ICF, 2 CSS). TF failed in demonstrating differences within and between the two groups.

DISCUSSION: ICF are potential imaging biomarkers for anti-angiogenic therapy assessment. The presented method may be expected to have advantages with respect to texture analysis-based methods regarding interpretability of results and setup of standardized image analysis protocols.

PMID:34091826 | DOI:10.1007/s10334-021-00930-3

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International Classification of Diseases Codes are Useful in Identifying Cirrhosis in Administrative Databases

Dig Dis Sci. 2021 Jun 6. doi: 10.1007/s10620-021-07076-1. Online ahead of print.

ABSTRACT

BACKGROUND: Health administrative databases are essential to define patient populations, make socioeconomic predictions, and facilitate medical research and healthcare planning. The accuracy of this data is dependent on valid codes/coding algorithms.

AIMS: The aim of this study was to systematically identify and summarize the validity of International Classification of Diseases (ICD) codes for identifying patients with cirrhosis in administrative data.

METHODS: Electronic databases, MEDLINE (via Ovid), EMBASE (via Ovid), the Web of Science, and CINAHL (via EBSCOhost), were searched for validation studies which compared ICD codes related to cirrhosis to a clinical reference standard, and reported statistical measures of performance.

RESULTS: Fourteen studies were included in the review. There was a large variation in the algorithms used to validate ICD codes to diagnose cirrhosis. Despite the variation, the positive predictive value (PPV) was greater than 84% and the specificity was greater than 75% in the majority of the studies. The negative predictive value (NPV) was lower, but still was associated with values greater than 70% in the majority of studies. Sensitivity data varied significantly with values ranging from 0.27 to 99%.

CONCLUSIONS: Evaluated ICD codes for cirrhosis, including codes for chronic liver disease, cirrhosis-specific codes, and cirrhosis-related complications, have demonstrated variable sensitivity and reasonable specificity for the identification of cirrhosis. Additional research is needed to maximize the identification of persons with cirrhosis to avoid underestimating the burden of disease.

PMID:34091800 | DOI:10.1007/s10620-021-07076-1

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Nevin Manimala Statistics

The preoperative localisation of small parathyroid adenomas improves when adding Tc-99m-Sestamibi SPECT to multiphase contrast-enhanced CT

Insights Imaging. 2021 Jun 5;12(1):72. doi: 10.1186/s13244-021-01016-3.

ABSTRACT

OBJECTIVES: To investigate the incremental value of Sestamibi SPECT combined with a non-enhanced and contrast-enhanced CT, using SPECT/CT, for the preoperative localisation of small parathyroid adenomas (PTA).

METHODS: Retrospectively, 147 patients surgically cured from primary hyperparathyroidism, as verified by biochemistry 6 months postoperatively, were included. All patients had preoperatively undergone a dual time 99mTechnetium-Sestamibi SPECT (S) with multiphase CT including native (N), arterial (A) and venous (V) phases. Independently, two radiologists blinded from both the surgical and the preoperative imaging reports, sequentially performed PTA localisation starting with either [A] or [V], thereafter [A + N] or [V + N] and finally with the complete [A + N + S] or [V + N + S]. PTA localisation was reported for each image-set. The readers results were combined and the diagnostic performance for each image set was determined. Sensitivity was also calculated for the different quartiles of PTA weight distribution.

RESULTS: The median adenoma weight was 315 mg. No statistically significant differences in diagnostic performance between arterial and venous based image sets were found. The net effect of adding [N] was to increase specificity. Sestamibi SPECT significantly increased the overall diagnostic accuracy for arterial- and venous-based image sets, p = 0.0008 and p = 0.001, respectively. [A + N + S] was found to have the highest diagnostic performance with 86.5% sensitivity and 94.9% overall accuracy. [A + N + S] was particularly advantageous for locating PTA in the lower weight quartiles.

CONCLUSIONS: Native CT-phase and dual time point Sestamibi SPECT increase specificity and sensitivity, respectively. These, in combination with a single contrast-enhanced CT-phase is the most optimal examination protocol for preoperative localisation of PTA using SPECT/CT.

PMID:34091801 | DOI:10.1186/s13244-021-01016-3

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The Relationship Between Chemokine and Chemokine Receptor Genes Polymorphisms and Chronic Obstructive Pulmonary Disease Susceptibility in Tatar Population from Russia: A Case Control Study

Biochem Genet. 2021 Jun 6. doi: 10.1007/s10528-021-10087-2. Online ahead of print.

ABSTRACT

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory lung disease affecting primarily distal respiratory pathways and lung parenchyma. This study aimed to determine possible genetic association of chemokine and chemokine receptor genes polymorphisms with COPD in a Tatar population from Russia. SNPs of CCL20, CCR6, CXCL8, CXCR1, CXCR2, CCL8, CCL23, CCR2, and CX3CL1 genes and their gene-gene interactions were analyzed for association with COPD in cohort of 601 patients and 617 controls. As a result statistically significant associations with COPD in the study group under the biologically plausible assumption of additive genetic model were identified in CCL20 (rs6749704) (P = 0.00001, OR 1.55), CCR6 (rs3093024) (P = 0.0003, OR 0.74), CCL8 (rs3138035) (P = 0.0001, OR 0.67), CX3CL1 (rs170364) (P = 0.023, OR 1.21), CXCL8 (rs4073) (P = 0.007, OR 1.23), CXCR2 (rs2230054) (P = 0.0002, OR 1.32). Following SNPs CCL20 (rs6749704), CX3CL1 (rs170364), CCL8 (rs3138035), CXCL8 (rs4073), CXCR2 (rs2230054) showed statistically significant association with COPD only in smokers. The association of CCR6 (rs3093024) with COPD was confirmed both in smokers and in non-smokers. A relationship between smoking index and CCL20 (rs6749704) (P = 0.04), CCR6 (rs3093024) (P = 0.007), CCL8 (rs3138035) (P = 0.0043), and CX3CL1 (rs170364) (P = 0.04) was revealed. A significant genotype-dependent variation of Forced Vital Capacity was observed for CCL23 (rs854655) (P = 0.04). Forced Expiratory Volume in 1 s / Forced Vital Capacity ratio was affected by CCL23 (rs854655) (P = 0.05) and CXCR2 (rs1126579) (P = 0.02). Using the APSampler algorithm, we obtained nine gene-gene combinations that remained significantly associated with COPD; loci CCR2 (rs1799864) and CCL8 (rs3138035) were involved in the largest number of the combinations. Our results indicate that CCL20 (rs6749704), CCR6 (rs3093024), CCR2 (rs1799864), CCL8 (rs3138035), CXCL8 (rs4073), CXCR1 (rs2234671), CXCR2 (rs2230054), and CX3CL1 (rs170364) polymorphisms are strongly associated with COPD in Tatar population from Russia, alone and in combinations. For the first time combination of the corresponding SNPs were considered and as a result 8 SNP patterns were associated with increased risk of COPD.

PMID:34091786 | DOI:10.1007/s10528-021-10087-2

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Evaluation of heat shock protein 70 and toll-like receptor 4 expression in gingival crevicular fluid in response to orthodontic forces

Clin Oral Investig. 2021 Jun 6. doi: 10.1007/s00784-021-04014-3. Online ahead of print.

ABSTRACT

OBJECTIVES: The aim of this study was to assess the concentrations of heat shock protein 70 (HSP70) and toll-like receptor 4 (TLR4) during orthodontic tooth movement and to compare their levels with interleukin-1β (IL-1β), a well-known proinflammatory biomarker.

MATERIALS AND METHODS: This study consisted of 20 patients (8 males, 12 females; mean age 14.75 ± 2.34 years) who needed maxillary premolar extraction and segmental canine distalization. Concentrations of HSP70, TLR4, and IL-1β were examined before extraction (T1), at the 1st (T2), 4th (T3), 7th (T4), 14th (T5), and 30th (T6) days of canine retraction by enzyme-linked immunosorbent assay analysis of gingival crevicular fluid samples. Statistical analyses were performed with repeated measure ANOVA and Spearman’s rank correlation coefficient analysis (p < 0.05).

RESULTS: HSP70 increased gradually from T1 to T6 and showed significant differences between T1-T6 and T2-T6 (T1:3.28 ± 0.92 ng/ml; T2:3.72 ± 0.66 ng/ml; T6:9.35 ± 2.45 ng/ml). The lowest TLR4 concentration was at T1, peaked at T3 and remained constant afterwards with significant differences between T1-T3, T1-T4, and T1-T6 (T1:0.71 ± 0.02 pg/ml; T3:1.04 ± 0.11 pg/ml; T4:0.95 ± 0.06 pg/ml; T6:1.00 ± 0.07 pg/ml). IL-1β increased from T1 to T6 with significant differences between T1-T4, T1-T5, and T1-T6 (T1:55.71 ± 5.48 pg/ml; T4:100.11 ± 16.92 pg/ml; T5:103.71 ± 23.19 pg/ml; T6:125.12 ± 22.04 pg/ml). The increase in HSP70 and TLR4 from T2-T3 showed a significant correlation (r = 0.598; p = 0.005).

CONCLUSIONS: The increased levels of HSP70, TLR4, and IL-1β show the contribution of these mediators to the inflammatory response from the early stages of orthodontic tooth movement.

CLINICAL RELEVANCE: The regulation of HSP70, TLR4, and/or IL-1β secretion during orthodontic force application could provide alterations for desired optimal tooth movement.

PMID:34091792 | DOI:10.1007/s00784-021-04014-3