Proteomic Characterization of Human Placenta: Insights into Potential Therapeutic Applications for Osteoarthritis.

Biologics have become increasingly prominent as therapeutics in recent years due to their innate immune-privileged nature, biocompatibility, and high levels of protein biofactors. The aim of the study is to characterise the biologic, lyophilized human placenta (LHP) and explore its therapeutic potential for osteoarthritis (OA). The presence of six bioactive constituents that regulate cell-extracellular matrix interaction was identified by liquid chromatography coupled to electrospray ionization and quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF/MS). Metalloproteinase inhibitor 3 (TIMP3), alpha-1 anti-trypsin (a1AT), basic fibroblast growth factor (bFGF), and transforming growth factor ß1 (TGFß1) were detected and quantified using ELISA. The total protein content present in LHP by Bradford assay was found to be 409.35 ± 0.005 µg/ml. The analytical techniques such as Attenuated Total Reflectance-Fourier Transform Infrared spectroscopy (ATR-FTIR), solid state carbon-13 Nuclear Magnetic Resonance (ssC13 NMR) spectroscopy, and Differential Scanning Calorimetry (DSC) revealed the secondary structure and conformational stability of LHP. X-Ray diffraction (XRD) studies showed its amorphous nature. Bioactivity assessment of LHP was performed in human keratinocytes (HaCaT) and human dermal fibroblasts (HDF) by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The LHP was highly proliferative against skin cells and non-toxic, based on the findings of the bioactivity assay. LHP has the potential to be used as a therapeutic agent for OA, as its characterisation unveiled its physical stability, significant concentration of bioactive components that are pertinent to cartilage repair and its conformational stability.

A systematic review and meta-analysis of diagnostic performance of fluorescein-guided sentinel lymph node biopsy in early breast cancer.

BACKGROUND: Evaluation of axillary lymph nodes status in cN0 axilla is performed by sentinel lymph node biopsy (SLNB) utilizing a combination of radioactive isotope and blue dye or alternative to isotope like Indocyanine green (ICG). Both are very resource-intensive; which has prompted development of low-cost technique of Fluorescein Sodium (FS)-guided SLNB. This systematic review and meta-analysis evaluate the diagnostic performance of FS-guided SLNB in early breast cancer. OBJECTIVES: The objective was to evaluate the diagnostic performance of FS for sentinel lymph node biopsy. METHODS: Eligibility criteria: Studies where SLNB was performed using FS. INFORMATION SOURCES: PubMed, EMBASE, Cochrane library and online clinical trial registers. Risk of bias: Articles were assessed for risk of bias using the QUADAS-2 tool. SYNTHESIS OF RESULTS: The main summary measures were pooled Sentinel Lymph Node Identification Rate (SLN-IR) and pooled False Negative Rate (FNR) using random-effects model. RESULTS: A total of 45 articles were retrieved by the initial systematic search. 7 out of the 45 studies comprising a total of 332 patients were included in the meta-analysis. The pooled SLN-IR was 93.2% (95% confidence interval [CI], 0.87-0.97; 87% to 97%). Five validation studies were included for pooling the false negative rate and included a total of 211 patients. The pooled FNR was 5.6% (95% confidence interval [CI], 2.9-9.07). CONCLUSION: Fluorescein-guided SLNB is a viable option for detection of lymph node metastases in clinically node negative patients with early breast cancer. It achieves a high pooled Sentinel Lymph Node Identification Rate (SLN-IR) of 93% with a false negative rate of 5.6% for the detection of axillary lymph node metastasis.

Recent Developments and Application of Mass Spectrometry Imaging in N-Glycosylation Studies: An Overview.

Among the most typical posttranslational modifications is glycosylation, which often involves the covalent binding of an oligosaccharide (glycan) to either an asparagine (N-linked) or a serine/threonine (O-linked) residue. Studies imply that the N-glycan portion of a glycoprotein could serve as a particular disease biomarker rather than the protein itself because N-linked glycans have been widely recognized to evolve with the advancement of tumors and other diseases. N-glycans found on protein asparagine sites have been especially significant. Since N-glycans play clearly defined functions in the folding of proteins, cellular transport, and transmission of signals, modifications to them have been linked to several illnesses. However, because these N-glycans' production is not template driven, they have a substantial morphological range, rendering it difficult to distinguish the species that are most relevant to biology and medicine using standard techniques. Mass spectrometry (MS) techniques have emerged as effective analytical tools for investigating the role of glycosylation in health and illness. This is due to developments in MS equipment, data collection, and sample handling techniques. By recording the spatial dimension of a glycan's distribution in situ, mass spectrometry imaging (MSI) builds atop existing methods while offering added knowledge concerning the structure and functionality of biomolecules. In this review article, we address the current development of glycan MSI, starting with the most used tissue imaging techniques and ionization sources before proceeding on to a discussion on applications and concluding with implications for clinical research.

Low-Cost Radio-Opaque Tumor Marking Techniques for Breast Cancer Patients Undergoing Neoadjuvant Chemotherapy: a Systematic Review.

Current standard of care localization techniques used in breast conserving surgery (BCS) after neoadjuvant chemotherapy (NACT) are expensive and may not be available in LMICs (lower-middle income countries). This review evaluated the efficacy of radio-opaque low-cost tumor markers. A systematic search was conducted as per PRISMA guidelines through November 30, 2022, for all studies using non-commercial radio-opaque tumor markers for patients undergoing BCS post NACT. Rate of unsatisfactory margin on final histology was the primary outcome. Oxford Centre for Evidence Based Medicine (OCEBM) levels were used to assess internal validity. After screening, 07 studies were included for data synthesis. For marking, four studies used LIGA clips, two used 5-mm cut pieces of K-wire, and one used cut pieces of 25-G needle. Incidence of unsatisfactory margins (positive/close) ranged from 0 to 11%. All studies found these low-cost markers to be feasible, with 100% pre-surgery visibility and 100% retrieval rate. Low-cost radio-opaque tumor markers (LIGA clips, 5-mm cut pieces of K-wire and 25-G needle) are effective methods of tumor localization especially for LMICs. Supplementary Information: The online version contains supplementary material available at 10.1007/s13193-023-01845-2.

US-Guided Hydrodissection and a Low-Cost Indigenous Retractor Facilitate Endoscopic Thyroid Surgery.

Hydrodissection of plane between thyroid and strap muscles and retraction of strap muscles using a low-cost indigenously made retractor are effective in overcoming technical difficulties in transoral endoscopic thyroid surgery. Laryngoscope, 134:993-994, 2024.

Correlation of thermal burn hepatic dysfunction with outcomes.

INTRODUCTION: Organ dysfunction and failure increase the morbidity and mortality following major burn. Alteration of liver morphology and function is common following major burns; however, it has not received much attention. In this study we have assessed the impact of thermal burn on liver in relation with mortality. MATERIAL AND METHODS: 55 patients (33 female and 22 males) with TBSA 10-90% and age ranged from 18 to 75 years were included. A bed side serial ultrasonography to assess the volume of liver and liver function tests was done on the 2nd, 9th and 16th day following burn. Baseline demographic and clinical information such as age, gender, burn size and outcome of patient were also collected. RESULTS -: 8 patients died during 2nd week following burn and 47 survived. The mean TBSA for survivors was 37% and for non survivors 80%. Mean liver volume in survivors steadily decreased from 1693.70 cm3 to 1631.31 cm3 over 3 weeks. Mean liver volume in non- survivors steadily increased from 1855.88 cm3 to 2028.50 cm3 over 2 weeks. Liver function test in survivors steadily improved while in non survivors it deteriorated over 2 weeks. CONCLUSION: There is a correlation between altered liver morphology and function with mortality among severely burnt patients however liver volume did not show statistical significance. A decreasing trend of liver dysfunction parameters and hepatomegaly following burn is associated with good prognosis.

Recent Advances and Applications of Ambient Mass Spectrometry Imaging in Cancer Research: An Overview.

Cancer metabolic variability has a significant impact on both diagnosis and treatment outcomes. The discovery of novel biological indicators and metabolic dysregulation, can significantly rely on comprehension of the modified metabolism in cancer, is a research focus. Tissue histology is a critical feature in the diagnostic testing of many ailments, such as cancer. To assess the surgical margin of the tumour on patients, frozen section histology is a tedious, laborious, and typically arbitrary method. Concurrent monitoring of ion images in tissues facilitated by the latest advancements in mass spectrometry imaging (MSI) is far more efficient than optical tissue image analysis utilized in conventional histopathology examination. This article focuses on the "desorption electrospray ionization (DESI)-MSI" technique's most recent advancements and uses in cancer research. DESI-MSI can provide wealthy information based on the variances in metabolites and lipids in normal and cancerous tissues by acquiring ion images of the lipid and metabolite variances on biopsy samples. As opposed to a systematic review, this article offers a synopsis of the most widely employed cutting-edge DESI-MSI techniques in cancer research.

Evaluation of peer role models as oral health education providers among school children in Mysuru, Karnataka, India.

BACKGROUND: India lacks organized school oral health programs, resulting in limited access to oral health care among children. The peer role models, or teachers, may help in bridging the gap to enhance knowledge on self-care preventive practices. The aim of the study was to evaluate and compare the effectiveness of dental health education (DHE) offered by qualified dental professional, trained teachers, and peer role models in promoting oral hygiene status and behavior among school-going children in Mysuru, Karnataka. MATERIALS AND METHODS: This was an interventional study conducted over a period of 3 months in an academic year in three selected schools in Mysuru City, India. A total of 120 students were divided into three groups - group 1 were given DHE (dental health education) by a dental professional, group 2 were given DHE by a trained teacher, and group 3 were given DHE by peer role models. Oral health knowledge was assessed using a close-ended questionnaire, plaque levels were assessed using Turesky Gilmore Glickman modification of Quigley Hein plaque index, and gingival status was assessed using Loe and Sillness gingival index. After 3 months, the same index and questionnaire were used post intervention. RESULTS: The mean scores for knowledge on dental caries at baseline in groups 1, 2, and 3 were 3.75 ± 1.25, 3.65 ± 1.07, and 3.40 ± 1.17, respectively, with no significant difference between the groups, which changed to 4.43 ± 1.27, 3.37 ± 1.14, and 4.93 ± 0.99, respectively, following intervention. Similar results were observed with regard to knowledge on gingival and periodontal diseases. The mean plaque scores at baseline for groups 1, 2, and 3 were 4.17 ± 0.30, 3.24 ± 0.70, and 4.10 ± 0.31, respectively, which changed to 3.85 ± 0.32, 3.90 ± 0.39, and 3.69 ± 0.34, respectively, in three groups following intervention. Post intervention, plaque scores and gingival scores significantly improved in groups 1 and 3 but worsened in group 2. Overall, knowledge scores improved in groups 1 and 3 for some questions, but improvement was not noted in some questions. CONCLUSION: Under the limitations of the study, it was found that peer role models were as effective as dental professionals in providing DHE in schools.

Vigorous-intensity exercise as a modulator of cardiac adipose tissue in women with obesity: a cross-sectional and randomized pilot study.

Cardiac adipose tissue (CAT) has become an important target for the reduction of disease risk. Supervised exercise programs have shown potential to "significantly" reduce CAT; however, the impact of different exercise modalities is not clear, and the relationships between CAT, physical activity (PA) levels and fitness (PFit) remain unknown. Therefore, the purpose of this study was to analyze the relationships between CAT, PA and PFit, and to explore the effects of different exercise modalities in a group of women with obesity. A total of 26 women (age: 23.41 ± 5.78 years-old) were enrolled in the cross-sectional study. PA, cardiorespiratory fitness, muscular strength, body composition and CAT were evaluated. The pilot intervention included 16 women randomized to a control (CON, n=5), high intensity interval training (HIIT, n = 5) and high-intensity circuit training (HICT, n=6) groups. Statistical analysis showed negative correlations between CAT and vigorous PA (VPA) (r s=-0.41, p=0.037); and between percent body fat (%BF), fat mass (FM), and all PA levels (r s=-0.41- -0.68, p<0.05); while muscle mass was positively associated with moderate-to-vigorous PA, and upper-body lean mass with all PA levels (r s =0.40-0.53, p<0.05). The HICT intervention showed significant improvements (p<0.05) in %BF, FM, fat free mass, and whole-body and lower extremities lean mass and strength after three weeks; however, only leg strength and upper extremities' FM improved significantly compared to CON and HICT. In conclusion, although all types of PA showed a positive influence on body fat content, only VPA significantly impacted on CAT volume. Moreover, three weeks of HICT induced positive changes in PFit in women with obesity. Further research is needed to explore VPA levels and high-intensity exercise interventions for short- and long-term CAT management.

Total vs less than total thyroidectomy for benign multinodular non-toxic goiter: an updated systematic review and meta-analysis.

BACKGROUND: We have performed an updated meta-analysis of randomized controlled trials (RCT) comparing total thyroidectomy (TT) with less than total thyroidectomy (LTT) for benign multinodular non-toxic goiter (BMNG). OBJECTIVES: The objective was to evaluate the effects and outcomes of TT as compared to LTT. METHODS: Eligibility criteria: RCTs comparing TT vs LTT. INFORMATION SOURCES: PubMed, Embase, Cochrane Library and online registers were searched for articles comparing TT with LTT. Risk of bias: Articles were assessed for risk of bias using the Cochrane's revised tool to assess risk of bias in randomized trials (RoB 2 tool). SYNTHESIS OF RESULTS: The main summary measures were risk difference using a random effects model. RESULTS: Five randomized controlled trials were included in the meta-analysis. Recurrence rate was lower for TT compared to LTT. Adverse events like temporary or permanent recurrent laryngeal nerve (RLN) palsy and permanent hypoparathyroidism were similar in both groups except for the rate of temporary hypoparathyroidism which was lower in the LTT group. DISCUSSION: All studies had unclear risk of bias for blinding of the participants and personnel and high risk of bias for certain selective reporting. This meta-analysis did not show any clear benefit or harm of either procedure (TT vs LTT) for goiter recurrence and re-operation rates (for both recurrence and incidental thyroid cancer). However, re-operation for goiter recurrence was significantly higher in the LTT group based on a single RCT. Evidence suggests increased rates of temporary hypoparathyroidism with TT but there was no difference in the rate of RLN palsy and permanent hypoparathyroidism between the two methods. The overall quality of evidence was low to moderate.

The Clinical and Laboratory Profiles of Immunocompetent Patients With Short-Duration Fever With Neutropenia in a Tertiary Care Hospital in Pune, India.

Background Management of a febrile patient is based on understanding the pathophysiology of an abnormal temperature and temperature regulation, impacts of fever, and its treatment. In the current study, we aimed to characterize and compare the epidemiological, etiologic, microbiological, serological, clinical, and outcome traits of febrile patients with acute neutropenia admitted to a tertiary care center in Western Maharashtra. Methods Adult patients with a history of fever of less than two weeks' duration and without any immunosuppressive state were screened with predefined inclusion and exclusion criteria. General and demographic information (age and gender), and clinical examinations (type and duration of fever) were recorded. Biochemical, hematologic (total and differential cell counts), and immunologic measurements (rapid malaria, dengue, Leptospira, and viral hepatitis antigen antibodies) were performed. Data were analyzed using an appropriate statistical package. Results A total of 403 (214 males) young adults (aged: 29±11 years) with clinical presentation of fever were studied. The majority (n=361, 89.6%) had low-grade continuous fever with an average duration of 3±1 (mean±standard deviation (SD)) days. Headache and myalgia were the common symptoms present, and patients had an average hospital stay of 4±1 days. Dengue (55%) was the most common cause of febrile neutropenia, and all patients recovered well without antibiotics and granulocyte colony-stimulating factor. The mean C-reactive protein (CRP) level was 61.4±4.4 mg/L. CRP and procalcitonin (PCT) were directly correlated with the degree of neutropenia and inversely correlated with total leucocyte count (TLC). Conclusions It was highlighted from this study that antibiotics are not necessary for viral infections that have been diagnosed to stop the development of secondary bacterial infections. A clinician should be aware of "when not to use antibiotics," or the world will soon have to deal with superbugs.

Quantification of excess Carbon-14 specific activity in terrestrial biota in the off-site locations of the PHWR nuclear power plant at Kaiga, India.

This is the first detailed study on 14C activity in the environment surrounding a nuclear facility in India. Samples of food matrices and wild plants from the off-site locations of the PHWR nuclear power plant (NPP) at Kaiga were analysed by liquid scintillation spectrometry, results were validated by accelerator mass spectrometry, and an extensive database (N = 142) was established. The stable isotope ratio of carbon (δ13C) in terrestrial plants varied from -33.5 to -23.3 ‰. The maximum excess 14C activity recorded in terrestrial biota was 44 Bq kg-1C (19 pMC). About 75 % of the samples exhibited specific activity in the range 228-249 Bq kg-1C (101-110 pMC). Statistical tests on the 14C specific activity dataset for 2.3-5, 5-10, and 10-20 km radial zones confirmed that the impact of the operation of the NPP on the environment beyond 5 km is minimal. The study suggests that the 14C activity released through gaseous effluents from Kaiga NPP is transported to greater distances along the axis of the valley than that predicted by the Gaussian plume model and those reported for other NPP sites worldwide. This is due to the unique topography of the Kaiga valley in which wind flow channelling, strong winds in the valley mouth, and calm wind within the valley due to the blocking effect by hills for the south-westerly wind regime play dominant roles in the transport of gaseous effluents. The 14C specific activity values at upwind monitoring stations located at >5 km distance from the NPP during the south-westerly wind regime were higher than those observed during the north-easterly wind regime when the same monitoring stations were located on the downwind side. The ingestion dose to the population in the 2.3-5 km radius zone, attributable to the release of 14C from the NPP, was 0.75 µSv y-1. This is a negligibly small fraction of the ICRP recommended dose limit of 1000 µSv y-1 for the public from other than natural sources. The dose due to the natural 14C activity in the Kaiga region was 12 µSv y-1, corresponding to the ambient natural activity of 230 Bq kg-1 C.

A Systematic Review and Meta-analysis of Touch Imprint Cytology and Frozen Section Biopsy and Their Comparison for Evaluation of Sentinel Lymph Node in Breast Cancer.

INTRODUCTION: Evaluation of axillary lymph nodes after sentinel lymph node biopsy (SLNB) in breast cancer is mostly done by intra-operative frozen section biopsy (FSB) and/ or touch imprint cytology (TIC). In this systematic review and meta-analysis, we have compared the accuracy of the two modalities. METHODS: PubMed, EMBASE, and Cochrane electronic databases were searched for articles comparing TIC with FSB. Articles were assessed for methodological and reporting quality. The main summary measures were pooled sensitivity, pooled specificity, and diagnostic accuracy using bivariate generalized linear mixed models using random effects. RESULTS: Fourteen studies were included. The pooled sensitivity, specificity, and diagnostic accuracy for FSB were 78%, 100%, and 98.57%. For TIC, the pooled sensitivity, specificity, and diagnostic accuracy were 74%, 98%, and 98.37%. For both methods, visual inspection of summary ROC curves and of forest plots did not show significant heterogeneity. CONCLUSION: TIC showed comparable sensitivity, specificity, and accuracy to FSB and hence can be used as its substitute as a rapid and economical test for the detection of axillary lymph node metastasis during SLNB especially in low-resource settings.

Diets Containing Egg or Whey Protein and Inulin Fiber Improve Energy Balance and Modulate Gut Microbiota in Exercising Obese Rats.

SCOPE: Dietary protein, prebiotic fiber, and exercise individually have been shown to aid in weight loss; however less is known of their combined effects on energy balance. The effects of diets high in protein and fiber, with exercise, on energy balance, hormones, and gut microbiota, were determined. METHODS AND RESULTS: Obese male rats were fed high-fat diets with high protein and fiber contents from egg protein and cellulose, egg protein and inulin, whey protein and cellulose, or whey protein and inulin, together with treadmill exercise. We found that inulin enriched diets decreased energy intake and respiratory quotient (RQ), increased energy expenditure (EE), and upregulated transcripts for cholecystokinin (CCK), peptide YY, and proglucagon in distal gut. Notably, CCK1-receptor blockade attenuated the hypophagic effects of diets and in particular whey-inulin diet, and ß-adrenergic blockade reduced EE across all diets. Egg-cellulose, egg-inulin, and whey-inulin diets decreased weight gain, adiposity, and hepatic lipidosis; decreased lipogenic transcripts, improved glycemic control, and upregulated hepatic glucose metabolism transcripts; and decreased plasma insulin and leptin. Importantly, diet was linked to altered gut microbial composition and plasma metabolomics, and a subset of predicted metagenome pathways and plasma metabolites significantly correlated, with plasma butyric acid the most strongly associated to metagenome function. CONCLUSION: Combination of dietary egg or whey protein with inulin and exercise improved energy balance, glucose metabolism, upregulated anorectic hormones, and selectively modulated gut microbiota and plasma metabolites.

Dietary whey and egg proteins interact with inulin fiber to modulate energy balance and gut microbiota in obese rats.

Diets supplemented with protein and fiber are well known to reduce food intake and weight gain; however, less is known about the combined effects of protein and prebiotic fiber on energy balance and gut microbiota composition. We compared effects of diets containing high egg or whey protein with cellulose or prebiotic (inulin) fiber on energy balance, gut microbiota, hormones, and metabolites. Male obese rats (n=8/group) were allocated to four diets: Egg albumen+Cellulose (EC), Egg albumen+Inulin (EI), Whey protein+Cellulose (WC), and Whey protein+Inulin (WI). Results revealed that diet-induced hypophagia was transient with EC and prolonged with EI and WI, compared to WC. Importantly, CCK-1 receptor antagonist (Devazepide) attenuated the hypophagic effects of EC, EI, and WI. Further, EC, EI and WI decreased respiratory quotient, energy expenditure, weight and adiposity gains, and improved glycemia, relative to WC. Propranolol (ß1-ß2-receptor blocker) attenuated diet-induced changes in energy expenditure. Transcript abundance of thermogenic markers in brown adipose tissue, plasma hormones, and metabolites especially acyl-carnitines and glycerophospholipids, were differentially altered by diets. Diet explained 25% of compositional differences in cecal microbiomes, but diets with same fiber type did not differ. Microbiota differing between groups also strongly correlated with gut hormones and metabolites. Species most strongly correlated to a marker for butyrate production were in highest abundance in inulin diets. Together, these findings indicate that inulin enriched diets containing egg or whey protein improved energy balance, decreased adiposity, and modulated gut microbiota and metabolites, with CCK signaling partly mediating the satiety effects of diets.

Axillary staging should be routine in primary rhabdomyosarcoma of breast: A rare case report and review of literature.

INTRODUCTION: Primary rhabdomyosarcoma (RMS) of breast is an uncommon entity and axillary lymph node (ALN) involvement is exceedingly rare. METHODS: Herein, we are reporting a case of RMS of breast with ALN metastasis in an adolescent girl. We searched Pubmed and Cochrane databases with keywords rhabdomyosarcoma and breast. All studies published in English language literature were included. Articles describing metastatic involvement of breast with RMS were excluded. RESULT: The initial search yielded a total of 8468 studies, out of which 03 were found to be duplicate. 8420 studies were excluded based on title and abstract as they did not fulfill inclusion criteria. Full text of the remaining 48 studies was screened. After full text screening, 26 case reports describing primary breast RMS were included. Overall 21% patients had axillary lymph node metastasis. CONCLUSION: Axillary staging should be considered in every patient undergoing surgery for breast RMS. However, it's impact on recurrence and survival could not be determined based on current review.

Analytical and bioanalytical HPLC method for simultaneous estimation of 5-fluorouracil and sonidegib.

Aim: To develop a new sensitive RP-HPLC method for simultaneous estimation of 5-fluorouracil (5-FU) and sonidegib (SDG). Materials & methods: Analytical and bioanalytical methods for simultaneous quantification of 5-FU and SDG in bulk, nanoformulations and in rat plasma were developed and validated using a gradient elution technique. Results: Separation of the analytes was effected on a Luna® C18 LC column using a mobile mixture comprising acetonitrile and acidified water. 5-FU and SDG were extracted from plasma matrix using liquid-liquid extraction. The applicability of the method was verified through single-dose oral pharmacokinetic study in Wistar rats. Conclusion: The developed methods allow a specific, sensitive and steady analytical procedure for the simultaneous estimation of 5-FU and SDG in nanoformulations and biological matrix.

NE-OBT and TFWT activity concentrations in wild plants in the vicinity of the PHWR nuclear power plant and control regions of the tropical monsoonal climatic region of the Indian subcontinent.

The results of the first detailed study, involving a large number of samples, on water equivalent factor (WEQp), non-exchangeable organically bound tritium (NE-OBT) and tissue free water tritium (TFWT) activity concentrations in predominant plant species of the tropical monsoonal climatic region, are presented. A total of 369 samples from the vicinity of the PHWR nuclear power plant (NPP) at Kaiga, West Coast of India, and 47 samples of the control region (region not affected by local anthropogenic sources) were analysed. The WEQp varied in the range of 0.347-0.666 L kg-1 with an overall mean value of 0.540 ± 0.045 L kg-1. The NE-OBT activity concentration varied in the range of <9.8-60.9 Bq L-1 of combustion water (mean = 24.6 ± 11.5 Bq L-1) and that of TFWT in the range of 9.2-60.5 Bq L-1 (mean = 30.7 ± 10.9 Bq L-1) in the vicinity of the NPP. Rigorous statistical analysis of the data confirmed that (i) the activity concentrations of both forms of tritium decreased with the increase in the distance between the sampling location and NPP, and beyond 10 km, it was similar to that of the control region, (ii) the incorporation of tritium released from the NPP into wild plant leaves is not species-dependent, (iii) the NE-OBT activity concentration in the 5-10 km zone exhibited a dependence on the prevailing wind regime with respect to the NPP, but not in the 2.3-5 km zone which suggests that the transport of tritium, released into the atmosphere as the gaseous effluent, through diffusion is a dominating factor governing its activity concentration in the 2.3-5 km zone. The NE-OBT to TFWT specific activity concentration ratio (R-value) had a mean value of 0.82 ± 0.27 (range: 0.38-1.64) for samples collected from the vicinity of the NPP and 1.93 ± 0.50 (range: 1.35-3.19) for the control region. Recording higher NE-OBT activity concentration and R-value at the control region highlights the necessity of detailed studies to understand the mechanism of NE-OBT partitioning in the terrestrial environment.

Optimisation of CO2 absorption and liquid scintillation counting method for carbon-14 specific activity measurement in atmospheric air.

A method for the determination of 14C activity in the ambient air was optimised with the development of a simple setup for the regeneration of CO2 from carbonate sample and saturating the absorber in <45 min for direct determination of activity by liquid scintillation counting (LSC). Atmospheric CO2 was trapped in NaOH solution and precipitated as BaCO3 by adding BaCl2. The carbonate sample was taken in a newly designed regeneration system, subjected to acid hydrolysis, and the absorber (CarboSorb-E) was saturated with the CO2 regenerated from carbonate sample. This allowed optimisation of CO2 absorption by the absorber (up to ~ 2.3941 g of CO2/10 mL with an average of 2.1688 g) and a minimum detectable activity value of 14 Bq kg-1C for a counting time of 300 min (8 Bq kg-1C for 1000 min) was achieved with Quantulus - 1220 LSC system. The necessity of (i) the measurement of the total volume of air sampled, (ii) the determination of trapping efficiency for CO2 in the NaOH, recovery of 14C in chemical processing of BaCO3, and subsequent regeneration and absorption processes, and (iii) independent determination of carbon content in the air for expressing the results in terms of 14C specific activity (Bq kg-1C), are avoided in this method. The method is capable of yielding accurate results, in a considerably shorter time when compared to previously reported methods, with a deviation of <2.2% from the target value (with a relative standard deviation of 1.1%, and a relative error of 0.53%) when ambient air samples from clean air region (region not affected by local anthropogenic sources of 14C) are analysed. Validation of the method was performed by (i) analysing BaCO3 sample derived from ambient air by accelerator mass spectrometry, and (ii) analysing the CO2 produced from the combustion of IAEA C3 reference material. Upon validation, the suitability of the method for determining small excess 14C specific activity in the vicinity of a nuclear power plant was demonstrated.

Optimisation of a batch thermal combustion method using a tube furnace oxidation system (pyrolyser) and LSC for carbon-14 determination in environmental matrices.

Accelerator mass spectrometry and benzene synthesis coupled with liquid scintillation spectrometry are often used for accurate measurements of 14C activity in the environmental matrices. Thermal oxidation is one of the methods employed for 14C determination in environmental matrices. In this method, the sample is oxidised at high temperature (600-900 °C) to convert carbon species to CO2 and trapped in an amine-based absorber for determining the activity in a liquid scintillation counting (LSC) system. In this study, the performance of a commercially available tube furnace system (pyrolyser), for batch combustion of samples, was evaluated for the determination of 14C specific activity in terrestrial biota samples. Significant improvements over the manufacturer specified method, which is primarily designed for analysis of samples with activity well above the environmental background level, was implemented to achieve accurate determination of 14C specific activity at ambient background level. In the improved method, the CO2 produced from the combustion of the sample was isolated from the combustion products through cryogenic trapping and then absorbed in the absorber (Carbo-Sorb E) through a simple off-line transfer process. This allowed (i) optimisation of CO2 absorption by the absorber (2.2477 g of CO2/10 mL), (ii) achieving good accuracy and precision in the measurements, and a minimum detectable activity value of 13 Bq kg-1C for a counting time of 300 min (7 Bq kg-1C for 1000 min), (iii) avoiding uncertainty associated with the determination of recovery of 14C in the combustion and trapping process, and (iv) elimination of the need for an independent determination of carbon content (%) for expressing the results in terms of 14C specific activity. The method is capable of yielding accurate results with a deviation of <2.4% from the target value for IAEA C3 quality assurance reference material (with a relative standard deviation of 1.40%, and relative error of 0.34%). The combined uncertainty (1σ) associated with the measurements was computed to be 3.4%. Upon optimisation, the suitability of the method for the determination of 14C specific activity in typical terrestrial biota samples of clean air region (region not affected by local anthropogenic sources) and for the quantification of a small increase in the 14C activity above ambient levels in the vicinity of a nuclear power plant is demonstrated.