An Electroanalytical Enzymeless α-Fe2O3-ZnO Hybrid Nanostructure-Based Sensor for Sensitive Quantification of Nitrite Ions

Nitrite monitoring serves as a fundamental practice for protecting public health, preserving environmental quality, ensuring food safety, maintaining industrial safety standards, and optimizing agricultural practices. Although many nitrite sensing methods have been recently developed, the quantification of nitrite remains challenging due to sensitivity and selectivity limitations. In this context, we present the fabrication of enzymeless iron oxide nanoparticle-modified zinc oxide nanorod (α-Fe2O3-ZnO NR) hybrid nanostructure-based nitrite sensor fabrication. The α-Fe2O3-ZnO NR hybrid nanostructure was synthesized using a two-step hydrothermal method and characterized in detail utilizing x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). These analyses confirm the successful synthesis of an α-Fe2O3-ZnO NR hybrid nanostructure, highlighting its morphology, purity, crystallinity, and elemental constituents. The α-Fe2O3-ZnO NR hybrid nanostructure was used to modify the SPCE (screen-printed carbon electrode) for enzymeless nitrite sensor fabrication. The voltammetric methods (i.e., cyclic voltammetry (CV) and differential pulse voltammetry (DPV)) were employed to explore the electrochemical characteristics of α-Fe2O3-ZnO NR/SPCE sensors for nitrite. Upon examination of the sensor's electrochemical behavior across a range of nitrite concentrations (0 to 500 µM), it is evident that the α-Fe2O3-ZnO NR hybrid nanostructure shows an increased response with increasing nitrite concentration. The sensor demonstrates a linear response to nitrite concentrations up to 400 µM, a remarkable sensitivity of 18.10 µA µM-1 cm-2, and a notably low detection threshold of 0.16 µM. Furthermore, its exceptional selectivity, stability, and reproducibility make it an ideal tool for accurately measuring nitrite levels in serum, yielding reliable outcomes. This advancement heralds a significant step forward in the field of environmental monitoring, offering a potent solution for the precise assessment of nitrite pollution.

Crystallinity as a factor of SERS stability of silver nanoparticles formed by Ar+ irradiation

The plasmonic sensors based on silver nanoparticles are limited in application due to their relatively fast degradation in the ambient atmosphere. The technology of ion-beam modification for the creation of monocrystalline silver nanoparticles (NPs) with stable plasmonic properties will expand the application of silver nanostructures. In the present study, highly-stable monocrystalline NPs were formed on the basis of a thin silver film by low-energy ion irradiation. Combined with lithography, this technique allows the creation of nanoparticle ensembles in variant forms. The characterization of the nanoparticles formed by ion-beam modification showed long-term outstanding for Ag nanoparticles stability of their plasmonic properties due to their monocrystalline structure. According to optical spectroscopy data, the reliable plasmonic properties in the ambient atmosphere are preserved for up to 39 days. The mapping of crystal violet dye via surface-enhanced Raman spectroscopy (SERS) revealed a strong amplification factor sustaining at least thrice as long as the one of similarly sized polycrystalline silver NPs formed by annealing. The plasmonic properties sustain more than a month of storage in the ambient atmosphere. Thus, ion-beam modification of silver film makes it possible to fabricate NPs with stable plasmonic properties and form clusters of NPs for sensor technology and SERS applications.

Prospective Evaluation of Locoregional Control in Oral Cavity Squamous Cell Carcinoma with Infratemporal Fossa Involvement Treated with Surgery and Adjuvant Concurrent Chemoradiotherapy

PURPOSE/OBJECTIVE(S)

Oral cavity squamous cell carcinoma (OCSCC) is the most common head and neck cancer in India. Definitive surgery with or without post-op radiotherapy (PORT) with or without chemotherapy (CT) provides better outcomes in locally advanced OCSCC as compared to definitive chemoradiotherapy. T4b OCSCC with infra temporal fossa (ITF) involvement has varied outcome depending on the extent of ITF involvement, with low and mid ITF having relatively favorable prognosis. We aimed to prospectively evaluate outcomes in patients of OCSCC with low or mid ITF involvement treated with curative surgery followed by adjuvant concurrent chemoradiotherapy (CCRT).

MATERIALS/METHODS

A total of 20 patients of T4b OCSCC (as per AJCC 8th edition) with low or mid ITF involvement were included in this single arm prospective interventional study from January 2021 to October 2022. Patients with involvement of skull base, carotid artery, prevertebral fascia and/or pterygomaxillary fissure were excluded. All patients were treated with definitive surgery with ITF clearance followed by adjuvant CCRT as indicated. Loco-regional control (LRC), Disease free survival (DFS), Overall survival (OS) were assessed using Kaplan-Meier survival analysis. Acute toxicities were assessed according to the CTCAE v5.0.

RESULTS

Patient characteristics are summarized in table 1. Median follow-up was 11.5 months (4-21months). All patients received adjuvant CCRT with weekly cisplatin 40mg/m2 to a median number of 6 cycles (5-7 cycles). Median RT dose was 64Gy (60-64Gy). All patients tolerated treatment well. Grade 3 oral mucositis, odynophagia were seen in 8 (40%) patients each and skin toxicity, oral pain in 6 (30%) and 5 (25%) patients respectively. No grade 4 toxicities were observed LRC at three month was 73.68% with 4 local and 1 locoregional failure only. LRC at one year was 36.8% with 8 local, 1 locoregional, 2 locodistant and 1 distant failure only. Median DFS was 10.4 months. Median OS was not reached; four patients died. LRC at three months was better for patients with low ITF disease as compared to mid ITF disease (85.7% vs. 40% (p = 0.04) and at one year was 42.8% vs. 40% (p = 0.50).

CONCLUSION

Selected patient of locally advanced OCSCC with low ITF involvement may benefit from trimodality therapy of surgery with ITF clearance followed by adjuvant CCRT. Acute toxicity profile was acceptable in our study.

Physisorption-Mediated Charge Transfer in TiS2 Nanodiscs: A Room Temperature Sensor for Highly Sensitive and Reversible Carbon Dioxide Detection

Real-time and high-performance monitoring of trace carbon dioxide (CO2) has become a necessity due to its substantial impact on the global climate, human health, indoor occupancy, and crop productivity. Two-dimensional materials such as transition metal dichalcogenides (TMDs) have gained significant interest in gas sensing applications owing to their intrinsically high surface-to-volume ratio. However, the research has been limited to prominent TMDs such as WS2 and MoS2. Specifically, the chemiresistive sensing performance of titanium disulfide (TiS2) has rarely been investigated. We present an electric-field-assisted TiS2 nanodisc assembly for the fabrication of a low-cost, low-power CO2 gas sensor based on charge transfer between physisorbed CO2 analyte molecules and TiS2 nanodiscs operating at room temperature. The physiochemical properties of the synthesized TiS2 nanodiscs were investigated via scanning electron microscopy (SEM), electron diffraction spectroscopy (EDS), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Raman spectroscopy. The fabricated sensor demonstrated an ultra-high sensor response of 60%, a fast response time of 37 s toward 500 ppm CO2 gas, and the lowest detection limit of 5 ppm under ambient conditions. The low adsorption energies and vdW interaction between CO2 molecules and TiS2 resulted in easy desorption, allowing the sensor to self-recover without the need for external stimuli, which is hardly been witnessed in other 2D material analogues. Furthermore, the sensor has excellent reproducibility and stability for successive analyte exposures, as well as excellent selectivity for CO2 over other interfering gases. This reported sensor based on 2D TMDs is the first of its type to integrate such a broad range of sensor characteristics (such as high sensor response and sensitivity, rapid response and recovery times, a high signal-to-noise ratio, and excellent selectivity at room temperature) into a single, revolutionary device for CO2 detection.

van der Waals Materials for Overcoming Fundamental Limitations in Photonic Integrated Circuitry

With the advance of on-chip nanophotonics, there is a high demand for high-refractive-index and low-loss materials. Currently, this technology is dominated by silicon, but van der Waals (vdW) materials with a high refractive index can offer a very advanced alternative. Still, up to now, it was not clear if the optical anisotropy perpendicular to the layers might be a hindering factor for the development of vdW nanophotonics. Here, we studied WS2-based waveguides in terms of their optical properties and, particularly, in terms of possible crosstalk distance. Surprisingly, we discovered that the low refractive index in the direction perpendicular to the atomic layers improves the characteristics of such devices, mainly due to expanding the range of parameters at which single-mode propagation can be achieved. Thus, using anisotropic materials offers new opportunities and novel control knobs when designing nanophotonic devices.

TiS3 Nanoribbons: A Novel Material for Ultra-Sensitive Photodetection across Extreme Temperature Ranges

Photodetectors that can operate over a wide range of temperatures, from cryogenic to elevated temperatures, are crucial for a variety of modern scientific fields, including aerospace, high-energy science, and astro-particle science. In this study, we investigate the temperature-dependent photodetection properties of titanium trisulfide (TiS₃)- in order to develop high-performance photodetectors that can operate across a wide range of temperatures (77 K-543 K). We fabricate a solid-state photodetector using the dielectrophoresis technique, which demonstrates a quick response (response/recovery time ~0.093 s) and high performance over a wide range of temperatures. Specifically, the photodetector exhibits a very high photocurrent (6.95 × 10^-5 A), photoresponsivity (1.624 × 10⁸ A/W), quantum efficiency (3.3 × 10⁸ A/W·nm), and detectivity (4.328 × 10¹⁵ Jones) for a 617 nm wavelength of light with a very weak intensity (~1.0 × 10^-5 W/cm²). The developed photodetector also shows a very high device ON/OFF ratio (~32). Prior to fabrication, the TiS₃ nanoribbons were synthesized using the chemical vapor technique and characterized according to their morphology, structure, stability, and electronic and optoelectronic properties; this was performed using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), and a UV-Visible-NIR spectrophotometer. We anticipate that this novel solid-state photodetector will have broad applications in modern optoelectronic devices.

Highly Sensitive Electrochemical Non-Enzymatic Uric Acid Sensor Based on Cobalt Oxide Puffy Balls-like Nanostructure

Early-stage uric acid (UA) abnormality detection is crucial for a healthy human. With the evolution of nanoscience, metal oxide nanostructure-based sensors have become a potential candidate for health monitoring due to their low-cost, easy-to-handle, and portability. Herein, we demonstrate the synthesis of puffy balls-like cobalt oxide nanostructure using a hydrothermal method and utilize them to modify the working electrode for non-enzymatic electrochemical sensor fabrication. The non-enzymatic electrochemical sensor was utilized for UA determination using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The puffy balls-shaped cobalt oxide nanostructure-modified glassy carbon (GC) electrode exhibited excellent electro-catalytic activity during UA detection. Interestingly, when we compared the sensitivity of non-enzymatic electrochemical UA sensors, the DPV technique resulted in high sensitivity (2158 µA/mM.cm²) compared to the CV technique (sensitivity = 307 µA/mM.cm²). The developed non-enzymatic electrochemical UA sensor showed good selectivity, stability, reproducibility, and applicability in the human serum. Moreover, this study indicates that the puffy balls-shaped cobalt oxide nanostructure can be utilized as electrode material for designing (bio)sensors to detect a specific analyte.

A65 VISCERAL FAT INDICES: DO THEY HELP DIFFERENTIATE CROHN’S DISEASE AND INTESTINAL TUBERCULOSIS IN CHILDREN?

Background

Crohn’s disease (CD) and Intestinal tuberculosis (ITB) mimic each other and are often difficult to differentiate. A correct and prompt diagnosis is essential for a good outcome. Mesenteric fat hypertrophy is a feature of CD and studies in adults have shown higher visceral fat in CD than ITB. There is no published data in children.

Purpose

This study evaluated the utility of visceral fat indices in differentiating CD and ITB in children.

Method

Symptomatic children diagnosed to have CD or ITB based on standard recommended criteria were enrolled. The clinical and laboratory details were noted. Abdominal fat was measured on Computed Tomography in supine position at the level of L4 vertebrae. Visceral fat (VF) and subcutaneous fat (SF) area was measured separately by an experienced radiologist, blinded to the diagnosis. Sum of VF and SF was taken as total fat (TF). VF/SF and VF/TF ratio was calculated.

Result(s)

34 children [14 boys, median age 14.0 (inter quartile range 10.8-17.0)] years were recruited, of which 12 (29%) had CD [7 boys, age 13.0 (IQR 9.25-16.5) years] and 22 (71%) had ITB [7 boys, age-14.5 (IQR 11-17) years]. Visceral fat area (VF) was significantly higher in CD compared to ITB (table 1). However, there was no significant difference in the SF (2199.5 (1537.6-3881.6) vs 2176.5 (671.0-6651.5) mm²; p=0.958) and TF (3096.1 (2108.2-5373.5) vs 4518.2 (2677.6-8456.3) mm²; p=0.245) in ITB and CD respectively. The ratio of VF/SF and VF/TF was significantly higher in CD as compared to ITB for all cases (table1). When comparing CD and ITB in boys and girls separately the same trend was observed but the difference was statistically significant only for boys. On ROC analysis, VF:SF ratio of 0.609 predicted CD with the sensitivity of 75% and specificity of 86.4% (area under curve [AUC]-0.795, 95% CI 0.636-0.955; p=0.005). VF:TF ratio of 0.379 had similar sensitivity of 75% and specificity of 86.4% (AUC-0.795, 95% CI 0.636-0.955; p=0.005). The VF area of 1485.26 mm² had a sensitivity of 83.3% and specificity of 72.7% for CD (AUC-0.758, 95% CI 0.590-0.925; p=0.01).

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Conclusion(s)

The VF/SF ratio is a simple, non-invasive, objective parameter to differentiate CD and ITB in children with a good sensitivity and specificity.

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Disclosure of Interest

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Polyethyleneimine-Starch Functionalization of Single-Walled Carbon Nanotubes for Carbon Dioxide Sensing at Room Temperature

There is an ever-growing interest in the detection of carbon dioxide (CO₂) due to health risks associated with CO₂ emissions. Hence, there is a need for low-power and low-cost CO₂ sensors for efficient monitoring and sensing of CO₂ analyte molecules in the environment. This study reports on the synthesis of single-walled carbon nanotubes (SWCNTs) that are functionalized using polyethyleneimine and starch (PEI-starch) in order to fabricate a PEI-starch functionalized SWCNT sensor for reversible CO₂ detection under ambient room conditions (T = 25 °C; RH = 53%). Field-emission scanning electron microscopy, high-resolution transmission electron microscopy, Raman spectroscopy, and Fourier transform infrared spectroscopy are used to analyze the physiochemical properties of the as-synthesized gas sensor. Due to the large specific surface area of SWCNTs and the efficient CO₂ capturing capabilities of the amine-rich PEI layer, the sensor possesses a high CO₂ adsorption capacity. When exposed to varying CO₂ concentrations between 50 and 500 ppm, the sensor response exhibits a linear relationship with an increase in analyte concentration, allowing it to operate reliably throughout a broad range of CO₂ concentrations. The sensing mechanism of the PEI-starch-functionalized SWCNT sensor is based on the reversible acid-base equilibrium chemical reactions between amino groups of PEI and adsorbed CO₂ molecules, which produce carbamates and bicarbonates. Due to the presence of hygroscopic starch that attracts more water molecules to the surface of SWCNTs, the adsorption capacity of CO₂ gas molecules is enhanced. After multiple cycles of analyte exposure, the sensor recovers to its initial resistance level via a UV-assisted recovery approach. In addition, the sensor exhibits great stability and reliability in multiple analyte gas exposures as well as excellent selectivity to carbon dioxide over other interfering gases such as carbon monoxide, oxygen, and ammonia, thereby showing the potential to monitor CO₂ levels in various infrastructure.

Field-Effect Transistor Based on 2D Microcrystalline MoS2 Film Grown by Sulfurization of Atomically Layer Deposited MoO3

Atomically thin molybdenum disulfide (MoS₂) is a promising channel material for next-generation thin-body field-effect transistors (FETs), which makes the development of methods allowing for its controllable synthesis over a large area an essential task. Currently, one of the cost-effective ways of its synthesis is the sulfurization of preliminary grown oxide- or metallic film. However, despite apparent progress in this field, the electronic quality of the obtained MoS₂ is inferior to that of exfoliated samples, making the detailed investigation of the sulfurized films' properties of great interest. In this work, we synthesized continuous MoS₂ films with a thickness of ≈2.2 nm via the sulfurization of an atomic-layer-deposited MoO₃ layer. X-ray photoelectron spectroscopy, transmission electron microscopy, and Raman spectroscopy indicated the appropriate chemical composition and microcrystalline structure of the obtained MoS₂ films. The semiconductor quality of the synthesized films was confirmed by the fabrication of a field-effect transistor (FET) with an I_on/I_off ratio of ≈40, which was limited primarily by the high contact resistance. The Schottky barrier height at the Au/MoS₂ interface was found to be ≈1.2 eV indicating the necessity of careful contact engineering. Due to its simplicity and cost-effectiveness, such a technique of MoS₂ synthesis still appears to be highly attractive for its applications in next-generation microelectronics. Therefore, further research of the electronic properties of films obtained via this technique is required.

Hydrogen sulphide infiltration downregulates oxidative metabolism and extends postharvest life of banana

Hydrogen sulphide (H₂ S) has emerged as a potential regulator of plant defence against different abiotic stresses. As a climacteric fruit, banana undergoes oxidative stresses shortly after harvest, resulting in faster ripening and senescence. This work examines the effects of vacuum infiltrated H₂ S on ripening inhibition of banana. Banana fruits were vacuum infiltrated with 1 mm H₂ S. Effects on oxidative stress markers, physiological changes, bioactive compounds and antioxidant potentials were examined during storage at 25 °C and 75-80% RH. Results indicate that treated fruits were less affected by oxidative stress, as evident by lower accumulation of ROS (superoxide and peroxide ions), elevated phenols content and antioxidant capacity. The ripening inhibitory effects of H₂ S delayed chlorophyll loss and reduced ethylene and CO₂ production. H₂ S infiltration also reduced MDA accumulation and electrolytic leakage, resulting in longer shelf life. Vacuum infiltration with H₂ S had a protective effect on postharvest banana through overcoming the deleterious effect of ROS and strengthening antioxidant potential. Thus, this method could be promising for enhanced preservation of banana during storage.

Bronco T (Shirisadi kasaya), a polyherbal formulation prevents LPS induced septicemia in rats

OBJECTIVE

Here, Bronco T (BT), a polyherbal formulation developed in 1984 for treating asthma, has been repurposed against septicemia-induced ALI.

MATERIALS AND METHODS

Lipopolysaccharides (3 mg/kg BW) were injected intraperitoneally before 24 hours of surgery to assess the cardiorespiratory parameters, blood PaO2/FiO2 and MPO, pulmonary water content and histological changes in the lungs. The pentoxifylline (PTX) (25 mg/kg BW) was used as the positive control and given one hour before LPS. BT was given 3 hours (orally at different doses of 3, 1.5 and 0.75 g/kg BW) before LPS.

RESULTS

The LPS treated group showed significant bradypnea, hypotension and bradycardia, through elongated peaks (RR) and (MAP) respectively and finally death after 95 minutes of LPS injection. The PTX and BT (3 g/kg BW) pretreatment significantly prevented these changes (dose-dependent in the BT group). The survival in these groups was maintained up to 190 min after LPS. The Pentoxifylline showed a better response (75%) than Bronco T (72%). In both the treatments, a significant decrease in pulmonary water content and minimal neutrophil infiltration and intact alveoli-capillary membrane was seen in the transverse section (T.S) of the lungs.

CONCLUSIONS

Significant improvement was noted in survival time with lesser tissue damage and improved pulmonary function was observed by pre-treating with Bronco T in LPS induced septicemia.

Molecular detection of Salmonella isolated from commercial chicken

BACKGROUND

Salmonella in chicken, specially, the motile salmonellae, causes the food chain unsafe from farm to table and is considered a significant global threat to public health.

AIMS

The present study was carried out for molecular detection of Salmonellae in commercial poultry using PCR.

METHODS

The study was conducted for eight months, from July 2019 to February 2020, and a total of 26 poultry farms, including 15 broiler and 11-layer farms, were visited individually. Pooled faecal samples were obtained from the sheds. A total of 189 necropsy cases were examined for gastrointestinal lesions. Isolation and identification of the organism were done using microbe culture method, and the molecular characterization was performed via PCR targeting invA and ent genes.

RESULTS

The prevalence of salmonellosis in the broiler and layer farms was recorded at 20.0% and 45.4%, respectively, through the traditional gold standard culture method. From 189 necropsy birds, salmonellosis was recorded at 1.58% dead cases. Molecular detection of Salmonella isolates by PCR targeting invA gene was confirmed in 13.33% of the broiler farms and 36.3% of the layer farms. Further detection of Salmonella enteritidis was performed by PCR targeting ent gene by which 11.11% positivity was determined.

CONCLUSION

This study, focused on the Salmonella prevalence, highlighted the zoonotic importance of the bacterium in the commercial poultry farms, which can subsequently be dispersed into the human food chain causing harmful health effects.

Effect of a dietary supplement on the reduction of lymphedema-progression in mouse tail-cut model

OBJECTIVE

The aim of our study was to evaluate in vivo, in a mouse tail model of lymphedema, the effects of a dietary supplement, Garlive®, based on hydroxytyrosol from olive leaves, spermidine from rice seeds, hesperidin from citrus fruits and vitamin A. Hydroxytyrosol has anti-inflammatory, antioxidant and antimicrobial activities and inhibits leukotriene B4 generation; spermidine is able to inhibit the production of pro-inflammatory cytokines and mediators; hesperidin inhibits the secretion of pro-inflammatory cytokines: IFN-γ, IL-2, IL-4, IL-10; vitamin A deficiency was shown to induce inflammation and aggravate existing inflammatory states, whereas supplementation with vitamin A could ameliorate inflammation.

MATERIALS AND METHODS

The active compounds were included in tablets: 250 mg of olive leaf extract titrated in 10% hydroxytyrosol, 200 mg of citrus fruits extract titrated in 60% hesperidin, 10 mg of rice (Oryza sativa) seeds extract titrated in 1% spermidine and 0.8 mg of vitamin A. Mice of an inbred group were randomly selected and divided in the control group and drug-treated group. The wound necessary for lymphedema generation was made on the tail of each mice 1 cm below the base of the trunk.

RESULTS

After surgical intervention, there was a gradual increase in the circumference of both ends of the wound. The control group showed higher increase of tail volume than the drug-treated group. The differences in tail swelling between the control group and the drug-treated group were significantly different. The peak of swelling was anticipated to the 6th day in the drug-treated group, whereas in the control group the peak was reached later on.

CONCLUSIONS

The tested drug prevented the induction of swelling from day 5th of wound creation and decreased the duration of swelling, favoring the wound healing.

1444 Is FBC Being Investigated Within 32 Hours of Surgery in Neck of Femur Fractures?

Introduction

The UK treats approximately 76,000 neck of femur (NOF) fractures annually (NHFD 2018). These patients are known to be frail and dehydrated upon arrival to the emergency department. Surgery can expose patients to substantial blood loss both preoperatively and postoperatively (Foss et al). Furthermore, studies have shown that postoperative anaemia is detrimental in patients who have had hip surgery (Marval et al 2014). Thus, it is imperative to monitor patients’ haemoglobin (Hb) levels immediately after the operation so that optimum treatment can be assured. The current audit standard in our local trust states that all patients must have their full blood count (FBC) within 32 hours post-surgery. As Covid-19 has brought disruption to the NHS, It is important for us to highlight any issues that arise in the monitoring of Hb in the post-operative phase of these NOF patients.

Method

Using retrospective analysis, this study analysed the number of patients having the FBC within 32 hours post-surgery during the pandemic (n = 60) and was compared to a similar cohort pre-pandemic (n = 139).

Results

91% of patients overall had their Hb checked within 32 hours. 92% in the pre-covid group had a Hb check within time compared to 81% in the covid group. The risk ratio calculated was 1.5.

Conclusions

Conclusively, patients in the covid group were 1.5 times more likely to have their FBC checked past 32 hours post-surgery. However, this finding was not significant. Overall, the audit standard was not met.

Role of postoperative intact serum PTH as an early predictor of severe post-thyroidectomy hypocalcemia: a prospective study

BACKGROUND

Post thyroidectomy hypocalcemia is a major sequel of thyroidectomy and continues to trouble the endocrinologists and the endocrine surgeons as there is no ideal predictive marker of hypocalcemia which has the potential to develop into a life-threatening complication. The role of early serum intact parathormone (iPTH) to predict post thyroidectomy hypocalcemia is becoming useful but the literature is still unclear regarding the optimal time of testing and the optimal cut-off value of serum iPTH.

PATIENTS AND METHODS

This is a prospective cohort study of 111 patients who underwent total thyroidectomy in a tertiary care endocrine surgery referral unit. Serum iPTH was measured after 20 min and 4 h of surgery. Receiver-Operator characteristic Curve (ROC) was used to find out of the best cut-off value of S. iPTH 20 min and 4 h after surgery in predicting hypocalcemia.

RESULTS

Hypocalcemia was noted in 60 (54%) out of 111 subjects who underwent total thyroidectomy. The best cut-off values of Serum iPTH to predict hypocalcemia was found to be 4.28 pmol/l at 20 min post total thyroidectomy with a sensitivity and specificity of 81.7% and 51%, respectively. In addition, patients with malignancy or central lymph nodal dissection were significantly over-represented in the hypocalcemia group with serum iPTH above the threshold level of 4.28 pmol/l. Below the cut off level, parenteral calcium supplementation was required in 23% (17/74) subjects while the rate was only 5.4% (2/37) patients when serum iPTH was above the cut-off level.

CONCLUSIONS

The decline of serum iPTH below a specific level after surgery has predictive value together with other factors strictly related to patient, the thyroid disease itself and surgery. The risk of development of hypocalcemia and consequent need for calcium supplementation should be evaluated by clinical assessment along with serum PTH measurement.

Characterization of plastic debris from surface waters of the eastern Arabian Sea-Indian Ocean

The quantity of floating plastic debris (FPD) is continuously being increased in the oceans. To assess their size, structure, and composition along the eastern Arabian Sea (EAS), FPD samples were collected by using a surface plankton net. The microplastic size fraction (0.5-5 mm) was the most prevalent accounting for >50% of the total, followed by mesoplastics (5-25 mm; ~40%) and macroplastics (>25 mm; ~10%). The collected FPDs were categorized into five different types and eight colours. Attenuated Total Reflectance-Fourier Transform Infrared Spectrometry (ATR-FTIR) analysis of the plastics revealed that polypropylene, polyethylene, and nylon were the most dominant polymers, and these comprised mostly of fibre/fishing line. The abundance of FPD in the EAS (0.013 ± 0.012 no.s/m³) was found to be very low compared to elsewhere. The prevalent microplastics presence in the oceans might have occurred mainly by the degradation of larger items. It increases bioavailability, and hence, is a risk to marine ecosystems.

Appearance of Temporal and Spatial Chaos in an Ecological System: A Mathematical Modeling Study

The ecological theory of species interactions rests largely on the competition, interference, and predator-prey models. In this paper, we propose and investigate a three-species predator-prey model to inspect the mutual interference between predators. We analyze boundedness and Kolmogorov conditions for the non-spatial model. The dynamical behavior of the system is analyzed by stability and Hopf bifurcation analysis. The Turing instability criteria for the Spatio-temporal system is estimated. In the numerical simulation, phase portrait with time evolution diagrams shows periodic and chaotic oscillations. Bifurcation diagrams show the very rich and complex dynamical behavior of the non-spatial model. We calculate the Lyapunov exponent to justify the dynamics of the non-spatial model. A variety of patterns like interference, spot, and stripe are observed with special emphasis on Beddington-DeAngelis function response. These complex patterns explore the beauty of the spatio-temporal model and it can be easily related to real-world biological systems.

Complications of tuberculous meningitis and their effect on outcome in a tertiary care cohort

BACKGROUND: To report the frequency and severity of complications, and their effect on the outcome of tuberculous meningitis (TBM).METHODS: In this retrospective cohort study, the following TBM complications were observed: status epilepticus (SE), hydrocephalus, paradoxical clinical worsening (PCW), hyponatremia, drug-induced hepatitis (DIH), infarction and mechanical ventilation (MV). These were recorded and correlated with stage of meningitis and outcome.RESULTS: A total of 144 patients with TBM (median age 26 years, range 12-75) were included. There were 76 (52.8%) females. The patients were in Stage I (n = 33), Stage II (n = 82) and Stage III (n = 29); 58 had definite TBM. Complications occurred in 128 (88.9%); complications included hydrocephalus (n = 58, 40.3%), hyponatremia (n = 70, 48.6%), infarction (n = 48, 33.3%), DIH (n = 42, 29.2%), SE (n = 16, 18.0%), MV (n = 43, 29.9%) and PCW (n = 24, 16.7%), with variable overlap. By 6 months, 33 patients had died. Death was related to PCW (P = 0.016), hyponatremia (P = 0.03), MV (P = 0.02), infarction (P = 0.03) and the number of complications. Except PCW, most complications occurred during the first month.CONCLUSIONS: In TBM, complications occurred in 128 (88.9%) patients, mainly in the early stages, with variable overlap. Infarction, PCW, hyponatremia and MV were predictive of poor outcome.

Evaluation of Changes in Microbiology and Periodontal Parameters During and After Fixed Orthodontic Appliances

The objective of the study was to evaluate the changes in microbiology through quantitative analysis of aerobic and anaerobic colonies and periodontal measurements during and after 1 month of removal of fixed orthodontic appliances. This prospective study comprised 30 patients, aged 12-30 years seeking orthodontic treatment in the department of Orthodontics and Dentofacial Orthopaedics of People's College of Dental Sciences and Research Centre, Bhopal from May 2016 to November 2017. Microbiological samples (supra- and subgingival plaque) and periodontal measurements like bleeding on probing (BOP), periodontal pocket depth (PPD) with oral hygiene assessment indices {plaque index (PI), gingival index (GI)} were used at 2 time interval: when patient undergoing orthodontic treatment >12 month (baseline, T₁) and 1 month after the removal of appliance (T₂). Bacterial culture method used to detect aerobic and anaerobic colony forming units (CFU) and their ratio (aerobic/anaerobic). Data analyzed using paired t-test and chi-square test. There was a significant decrease in an aerobic and anaerobic CFU (both supra- and subgingivally) and increase in CFU ratio (relatively less anaerobes) (p≤0.05) at T₂. Supragingival plaque sampling showed greater diminution in the CFU count as compared to the subgingival CFU, as these sites are more accessible for maintaining hygiene. Also, periodontal measurements showed significant decrement (PI, GI, PPD and BOP) at T₂ (p≤0.05). Fixed orthodontic treatment has transient effect on periodontium as supra- and subgingival CFU count decreases and periodontal health was ameliorated after removal of appliances which was accompanied with periodontopathic bacteria and clinical periodontal signs of inflammation during treatment.

Drying of citrus grandis (pomelo) fruit juice using block freeze concentration and spray drying

Pomelo fruit juice is concentrated using two different techniques, i.e. block freeze concentration (BFC) and thermal concentration (TC), and both concentrates were spray dried separately to observe the effects of two different concentration techniques on the physicochemical properties of the spray dried powder. BFC juice had comparatively better values of retention of acidity, colour, vitamin C, DPPH● scavenging activity, total phenolic content (TPC), and total sugar content than TC juice. The powder obtained from the combination of BFC and spray drying had better retention of vitamin C (121.17 mg/100 g), colour, and exhibited higher DPPH● scavenging activity than TC spray dried powder. The physical parameters including solubility index, bulk density, and hygroscopicity were significantly higher in BFC spray dried powder. BFC was observed as an efficient concentration technique in comparison to TC as a pretreatment to produce spray dried powder with a better retention of bioactive components and powder flow properties.

A Comparison of the Reliability of the Patellar Tendon-Trochlear Groove (PTTG) Distance and the Tibial Tuberosity-Trochlear Groove (TTTG) Distance Measured on MRI

Introduction:

An increased tibial tuberosity-trochlear groove (TTTG) distance is used for deciding a treatment plan in patello-femoral instability (PFI). The centre of the patellar tendon and the chondral trochlear groove can be directly visualised on MRI, and measured, giving the patellar tendon-trochlear groove (PTTG) distance. A study was designed to compare the inter-rater and the test-retest reliabilities of PTTG and TTTG measurements in MRI of patients without PFI and in a group with PFI.

Materials and Methods:

This cross-sectional reliability study was done on archival MRI films of 50 patients without patellar instability and 20 patients with patellar instability. TTTG and PTTG distances were independently measured by two orthopaedic surgeons and two radiologists. A hybrid PTTG measurement with bony landmarks on the femoral side and the patellar tendon landmark on the tibial side, was used to estimate the influence of the differences in the femoral and tibial landmarks on the difference in reliabilities. The intra-class correlation coefficient (ICC) was calculated for all four raters, as well as separately for each rater.

Results:

The PTTG distance had a higher inter-rater reliability (ICC=0.86, 95% CI=0.79-0.92) compared to the TTTG distance (ICC=0.70, 95% CI=0.59-0.80) in patients without PFI. Similar trends were seen in patients with PFI (0.83 vs 0.66). The inter-rater reliability for the hybrid PTTG distance was found to lie in between the TTTG and PTTG.

Conclusions:

The MRI-based PTTG distance had better inter-rater reliability compared with the MRI-based TTTG distance.

SERS Platform for Dengue Diagnosis from Clinical Samples Employing a Hand Held Raman Spectrometer

Dengue is a serious global health concern especially in tropical and subtropical countries. About 2.5 billion of the world's population is at risk for dengue infection. Early diagnosis is the key to prevent the deterioration of health of the patient to severe illness. Laboratory diagnosis of dengue is essential for providing appropriate supportive treatment to dengue patients with febrile illness, which is difficult to diagnose clinically. Here, we demonstrate surface enhanced Raman scattering (SERS) based diagnosis of dengue virus in clinical blood samples collected from total of 102 subjects. All of the samples were well characterized by conventional NS1 antigen and IgM antibody ELISA kits. The silver nanorods array fabricated by glancing angle deposition technique were employed as SERS substrates. A small amount of patient blood serum (5 μL) was taken for analysis and the report was prepared within a minute. SERS spectra of pure NS1 protein as well as spiked in serum was also recorded separately. Principal component analysis (PCA) was employed as the statistical tool to differentiate dengue positive, dengue negative, and healthy subjects on the basis of their respective SERS spectra. This method provides a sensitive, rapid, and field deployable diagnosis of dengue at the early stage (within 5 days of the onset of symptoms).

Prompt diagnosis of Scedosporium apiospermum soft tissue infection: Life-saving in a renal transplant recipient

Scedosporium apiospermum, an ubiquitous filamentous fungus, a known cause of mycetoma, is emerging as an opportunistic pathogen in immunocompromised individuals. We report a case of painful foot abscess in a renal allograft recipient on immunosuppressive therapy, which was clinically diagnosed as a suppurative bacterial abscess. Pus was aspirated, which showed septate, branching hyphal elements and culture on Sabouraud's dextrose agar yielded S. apiospermum, which was identified based on its macroscopic and microscopic features. There are very few reports of scedosporiasis from India. High index of suspicion for unusual fungal infection helps in prompt etiological diagnosis in a transplant recipient and rapid management prevents further dissemination.

Improvements in the Performance of a Visible-NIR Photodetector Using Horizontally Aligned TiS3 Nanoribbons

We report the fabrication and characterization of visible and near-infrared-resistive photodetector using horizontally aligned titanium tri sulfide (TiS3) nanoribbons. The fabrication process employed micro-electromechanical system, photolithography and dielectrophoretic (DEP) methods. The interdigitated electrodes (IDE) fingers were fabricated using photolithography and thin-film metallization techniques onto the Si/SiO2 substrate, and then TiS3 nanoribbons were horizontally aligned in between IDE using DEP. The fabricated device was first characterized in absence of light and then, the photodetector-based characteristics were obtained by illuminating it with fiber-coupled laser beam. These characteristics were optimized by varying wavelength and power density of the laser beam. The present photodetector shows a maximum responsivity of 5.22 × 102 A/W, quantum efficiency of 6.08 × 102, and detectivity of 1.69 × 109 Jones. The switching times, i.e., response and recovery times were found to be 1.53 and 0.74 s, respectively, with 1064 nm wavelength and 3.4 mW/mm2 power density of the laser beam. Also, the effect of O2 adsorption on nanoribbons has been studied and it is found that adsorbed O2 acts as electron acceptor and decreases the conductivity of the photodetector. Experimentally, it is found that the photoresponse of the horizontally aligned TiS3 nanoribbons is better than that of a randomly oriented TiS3 nanoribbon-based photodetector. Finally, the performance of the present photodetector was compared to that of the previous ones that were found to outperform the reported ones. The additional advantages of the photodetector include excellent stability and portability from which it may be concluded that TiS3 nanoribbons can be a promising candidate for application in nanoscale electronic and optoelectronic devices.

Influence of growth temperature on titanium sulphide nanostructures: from trisulphide nanosheets and nanoribbons to disulphide nanodiscs

We report the fabrication and characterization of titanium sulphide nanostructures using a chemical vapour transport (CVT) method. In CVT, reactions occur between titanium and sulphur powder in the vapor phase for TiS_x nanostructure growth. Systematic studies on the effect of temperature, consequent structural evolution and optical properties were investigated by various characterization techniques. A series of experiments were performed by maintaining a fixed compositional ratio (1 : 3) of Ti and S within a temperature range from 400 °C to 650 °C. On increasing the temperature from 400 °C to 650 °C; a gradual change in morphology was obtained from nanosheets (NS) to mixed phase nanoribbons and nanosheets (NS: NR), nanoribbons (NR), and nanodiscs (ND) of titanium sulphide, which was confirmed using SEM/TEM analysis. Then, the composition of titanium sulphides was studied using XRD, EDX and Raman spectroscopic techniques and it is observed that NS, NR and NS: NR have the composition ratio of TiS₃ whereas ND has a ratio of TiS₂. The phenomenon of decomposition of TiS₃ into TiS₂ at elevated temperatures was explained using thermogravimetric analysis (TGA) and differential thermal analysis (DTA) along with pictorial representations. The optical properties of the prepared TiS₃/TiS₂ nanostructures were studied using UV-vis and photoluminescence spectroscopy. It is concluded that composition ratio of Ti and S as well as the temperature variation plays a crucial role in the formation of different Ti–S nanostructures with unique optical, electronic and thermal properties.

We report the fabrication and characterization of titanium sulphide nanostructures using a chemical vapour transport (CVT) method.

Prevalence and predictors of delayed clinical diagnosis of Type 2 diabetes: a longitudinal cohort study

AIMS

To examine the prevalence and person-level predictors of undiagnosed Type 2 diabetes among adults with elevated HbA_1c values.

METHODS

We identified adults without diabetes who had a first elevated HbA_1c (index HbA_1c ≥ 48 mmol/mol; ≥ 6.5%) between January 2014 and December 2015, and classified them by Type 2 diabetes diagnosis status at 1 year following this result. Multilevel modelling techniques were used to examine the association of individual demographic, clinical, and utilization characteristics with remaining undiagnosed. We quantified differences in early Type 2 diabetes care between diagnosed and undiagnosed individuals.

RESULTS

Of the 18 356 adults with a first elevated index HbA_1c , 30.2% remained undiagnosed with Type 2 diabetes 1 year later. Individuals with lower index HbA_1c values [adjusted odds ratio (aOR) 5.95, 95% confidence interval (CI) 5.21-6.78 for 48 to <53 mmol/mol (6.5% to 7.0%); referent 53 to <64 mmol/mol (7.0% to <8.0%)], who were ≥ 70 years old (aOR 1.40, 95% CI 1.24-1.59; referent 50-59 years), and who had a prior prediabetes diagnosis (aOR 1.35, 95% CI 1.24-1.47; referent no prediabetes) had increased odds of remaining undiagnosed. After adjusting for age, race, and index HbA_1c , remaining undiagnosed was associated with lower odds of initiating metformin (aOR 0.06, 95% CI 0.05-0.07).

CONCLUSIONS

Almost one-third of adults with an elevated HbA_1c value were not diagnosed with Type 2 diabetes within 1 year. Undiagnosed Type 2 diabetes, in turn, was associated with differences in early care. Strategies that leverage the electronic health record to facilitate earlier diagnosis may help reduce delays and allow for early intervention towards the goal of improved outcomes.

Vulnerabilities and risks of HIV infection among migrants in the Thane district, India

OBJECTIVES

To explore the vulnerabilities and risks of HIV infection among female migrants compared with male migrants in the Thane district of Maharashtra, India.

STUDY DESIGN

This is a cross-sectional epidemiological study.

METHODS

Data from 35,841 migrants (men 96.2% and women 3.8%) were collected using the web-based 'Migrant Service Delivery System.' The data were then analysed in SPSS, version 23.0. Statistical analysis, including Chi-squared test and multivariate logistic regression, was used to identify factors influencing HIV infection for both male and female migrants.

RESULTS

It was observed that 2.96% of female migrants had HIV infection compared with 0.77% of male migrants. We found that 12.1% of women consumed alcohol compared with 41.9% of men, and access to bars was 1.5% among women and 3.5% in men. We observed an even larger difference between men and women in their previous history of using brothels for sex; only 5.9% of female migrants reported previously having used brothels for sex, compared with 62.9% of male migrants. Approximately 12.3% of married women and 93.6% of married men had sex with someone other than their spouse. We found that 67.0% of married women and 73.9% of married men reported using a condom during their last sexual act compared with 60.9% of unmarried women and 68.1% of unmarried men.

CONCLUSIONS

In Thane, female migrants faced higher vulnerabilities and risks of HIV infection than male migrants. Consequently, innovative strategies are required to address these particular needs of female migrants.

Single-wall carbon nanotube based electrochemical immunoassay for leukemia detection

A label-free electrochemical immunosensor is fabricated using high quality single-walled carbon nanotube for early detection of leukemia cells. It is based on P-glycoprotein (P-gp) expression level detection; by effective surface immune-complex formation with the monoclonal anti-P-glycoprotein antibodies bound to an epoxy modified nanotube surface. The expression level of P-gp on the leukemia cell surface detected by cyclic voltammetry is in good agreement with immunofluorescence microscopy studies. The proposed biosensor could be used for the detection of P-gp expressing cells within a linear range of 1.5 × 10³ cells/mL - 1.5 × 10⁷ cells/mL where lowest detection limit is found to be 19 cells/mL. A calibration plot of peak current v/s the logarithm of concentration of leukemia K562 cells is found linear with a regression coefficient of 0.935. This strategy promises high sensitivity, low-cost, fast, and repeatable recognition of cancer cells. The immunosensor was stable for three weeks and showed good precision with the relative standard deviation (RSD) of 3.57% and 2.12% assayed at the cell concentrations of 1.5 × 10³ and 1.5 × 10⁵ cells mL^-1 respectively. The proposed single-wall carbon nanotube based immunosensor showed better analytical performance in comparison to similar leukemia electrochemical sensors reported.

A Randomized Controlled Trial to Compare the Efficacy of Intravenous Dexmedetomidine and Clonidine as Adjuvants to Low Dose Opioid in Attenuation of Hemodynamic Response to Laryngoscopy and Tracheal Intubation

Increase in sympathetic activity as a result of cardiovascular stress response to laryngoscopy can be detrimental to the patient. The primary objective is to compare intravenous dexmedetomidine and clonidine as adjuvants to low dose opioid (fentanyl) for attenuation of hemodynamic response to laryngoscopy and tracheal intubation. The secondary objectives are to compare the perioperative dose requirement of fentanyl and thiopentone, to compare the duration of postoperative analgesia, and to look for side effects in all three groups. This randomized controlled trial was performed in a tertiary care hospital in North India from November 2012 to April 2014. One hundred twenty (120) patients (ASA I or II) posted for elective surgery under general anesthesia. Group D received intravenous dexmedetomidine (1μg/kg) with intravenous fentanyl (1μg/kg), Group C received intravenous clonidine (1μg/kg) with intravenous fentanyl (1μg/kg) and Group F received intravenous fentanyl (2μg/kg). Heart rate and mean arterial pressure were recorded at baseline, after study drug at 5, 10 & 15 minutes, after induction, intubation (0 min) and 1, 3, 5, 10, 15 minutes after intubation. The required perioperative doses of thiopentone and fentanyl, and time to first rescue analgesia given in postoperative period were also noted. One way ANOVA and Repeated Measures ANOVA followed by multiple comparisons (if applicable) were used for data analysis. P value <0.05 was considered statistically significant. The rise in HR and MAP at laryngoscopy and intubation was found to be less in clonidine group as compared to fentanyl group and dexmedetomidine was able to abolish this rise completely. The requirement of thiopentone and fentanyl were significantly least in dexmedetomidine group and the duration of time to first rescue analgesia was significantly prolonged in clonidine group. Intravenous fentanyl (2μg/kg) failed, addition of clonidine to fentanyl was able to partially blunt it, but the addition of dexmedetomidine to fentanyl completely abolished the hemodynamic response to laryngoscopy and intubation.